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Sample records for bcl2 p53 genes

  1. THE OVEREXPRESSION OF APOPTOSIS -RELATED GENES OF P53 AND BCL-2 IN CERVICAL CARCINOMA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective To investigate the significance of overexpression of P53 and bcl-2 protein in carcinogenesis of cervix. Methods 10 cases of cervical intraepithelial neoplasis(CIN) and 57 cases of invasive cancer were investigated with immunohistochemistry technique. Results The overexpresion of P53 protein in CIN and cervical cancer was significantly higher than that of control, respectively (P<0.01). But there was no significant difference between CIN and cervical cancer(P>0. 05). The immunoreactivity of bcl-2 in CIN was much more higher than that of control (P<0.05). The positive rate and immunoreactivity of bcl-2 in cervical carcinoma were both remarkably higher than those of control (P<0. 01) ,but there was no significant difference between CIN and cervical carcinoma (P>0. 05). It was also found that there was a remarkably positive correlation between the overexpression of bcl-2 and P53 (P<0.01). Conclusion Because of the loss of wtP53 function,the expression of bcl-2 can not be down-reguated,which is associated with the pathogenesis and development of cervical carcinoma.

  2. Study of the expressions of p53 and bcl-2 genes, the telomerase activity and apoptosis in GIST patients

    Institute of Scientific and Technical Information of China (English)

    Qiang Wang; You-Wei Kou

    2007-01-01

    AIM: To explore the relationship between clinicobiological behavior and the expression levels of telomerase activity,apoptosis, p53 gene and bcl-2 gene in gastrointestinal stromal tumors (GISTs).METHODS: The intensity of telomerase activity,apoptosis, p53 and bcl-2 expression in GISTs were detected by telomeric repeat amplification protocol, in situ end-labeling technique, and immunohistochemistry,respectively.RESULTS: The positive rates of telomerase activity of malignant GIST, potential malignant GIST and benign GIST were 85% (17/20), 22.8% (2/9) and 0 (0/9),respectively. The apoptosis indices of malignant GIST,potential malignant GIST, and benign GIST were 11.7 ± 5.4, 30.2 ± 5.6 and 45.2 ± 7.2, respectively. The intensity of telomerase activity and apoptosis were related to the biological characteristics of GISTs (85% vs 22.8%, 0, 0; P < 0.01 or 11.7±5.4 vs 30.2 ± 5.6, 45.2 ± 7.2, 72.1 ± 9.3; P < 0.05). The intensity of telomerase activity was negatively correlated with cellular apoptosis (22.9 ± 8.4 vs 9.5 ± 5.7, P < 0.01). The intensity of telomerase activity was positively correlated with p53,bcl-2 expression (40.0% vs 78.9%, 40.0% vs 84.2%;P < 0.05).CONCLUSION: The detection of telomerase activity,apoptosis and its control genes in GIST will be helpful for the discrimination of the malignant and benign GIST and evaluation of the prognosis.

  3. Detection of apoptotic cells and immunohistochemical study of bcl-2 and p53 gene protein in primary gastric mucosa-associated lymphoid tissue (MALT) lymphoma

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To identify the apoptotic cells in gastric MALT lymphoma and its relationship between bcl-2 and p53 gene expression. Methods: TdT-mediated dUTP biotin Nick End labeling (TUNEL) and immuno-histochemistry ABC method were used to display apoptotic cells and the gene protein expression of bcl-2 and p53 independently. Results: Apoptotic indices (AI) in high-grade MALT lymphomas were significantly higher than in mixed-grade group and low-grade group (P<0.05). Bcl-2 was expressed in 83% of low-grade tumors, 61.6% of the median-grade tumors and 43.7% of high-grade tumors. An inverse correlation was observed between the expression of bcl-2 and apoptotic indices. Only 27 cases were p53 positive. The frequency of p53 positivity was significantly increased as the histologic grade advanced (P<0.05). There was also an inverse correlation between the expression of bcl-2 and p53. Conclusion: Apoptosis may be important in tumors development and transmission. P53 and bcl-2 were important regulatory genes of apoptosis and may be associated with transformation from low-grade to high-grade lymphomas.

  4. The role of the expression of bcl-2, p53 gene in tamoxifen-induced apoptosis of breast cancer cells and its relationship with hormone receptor status

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    Noh, Woo Chul; Ham, Yong Ho [Korea Cancer Center Hospital, Seoul (Korea, Republic of)

    1998-01-01

    To investigate the relationship of bcl-2, p53, ER and tamoxifen-induced apoptosis of breast cancer cells, MCF-7 (ER+/bcl-2+/p53-) and MB MDA 468 (ER-/bcl-2-/p53+) cell line were cultured in estrogen-free condition. E2(10`-`9M) and tamoxifen (10`-`5M) were added to the media. The changes of bcl-2 and mutant p53 protein were checked by Western blot and apoptosis were measured by flowcytometry. In MCF-7 cells, we found that treatment with tamoxifen resulted in a decrease in bcl-2 protein level, but produced no change in mutant p53. In MB MDA 468 cell however, there were no changes of bcl-2 and mutant p53 protein level when E2 or tamoxifen were added. Apoptotic cells increased with time-dependent pattern when tamoxifen was added to MCF-7 cells. According to these result, ER+/blc-2+/mutant p53- cells, when treated with tamoxifen, were converted into bcl-2/mutant p53- cells which were more prone to apoptosis than bcl-2-/mutant p53+ cells. The paradoxical correlation of bcl-2 and ER which had been observed in clinical studies might be explained with this results and bcl-2 protein seems to be one of important factors that can predict the effect of hormone therapy. (author). 26 refs., 5 figs

  5. Effect of captopril and paraquat on expression of p53 and Bcl-2 genes and proteins in rat lung tissue using RT-PCR and immunohistochemistry

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    Azizi E

    2008-10-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Paraquat is an herbicide produced and used prevalently worldwide. Studies have shown that lung fibrosis induced by paraquat can be prevented or delayed by certain antioxidants, iron chelating agents, melatonin, and, recently, blood pressure lowering drugs such as captopril."n"n Methods: The protective effects of captopril on paraquat toxicity were studied using RT-PCR and immunohistochemistry to determine the gene and protein expression of p53 and Bcl-2 in lung tissue samples from rats treated with captopril before and after exposure to paraquat."n"n Results: We found no significant difference in the gene and protein expression of p53 in different tissue samples, except for mRNA levels in the lung tissue of captopril-treated rats. However, the protein expression of Bcl-2 is greater in tissue from rats exposed to paraquat alone and paraquat together with pre- and posttreatment with captopril compared to tissue from untreated control rats and from those treated with captopril alone, which can be due to inflammatory responses of lung tissue. By RT-PCR, we were unable to detect Bcl-2 in lung tissue samples."n"n Conclusion: These results show that paraquat does not induce significant DNA damage; therefore, the

  6. Expression of Apoptosis Related Genes bcl-2 and p53 in Rat Brain after Exposure to +Gx in Simulated Emergent Return of Spacecraft%模拟飞船应急返回时+Gx暴露后大鼠脑细胞凋亡相关基因bcl-2p53的表达

    Institute of Scientific and Technical Information of China (English)

    孙喜庆; 徐志鹏; 刘挺松; 吴斌; 张舒; 由广兴

    2005-01-01

    目的探讨bcl-2p53在模拟飞船应急返回时高+Gx作用致大鼠脑细胞凋亡中的作用. 方法 40只雄性SD大鼠随机分为4组,即对照组、+15 Gx组、7 d模拟失重组、7 d模拟失重后再+15 Gx组,每组10只.大鼠在动物离心机上承受+Gx作用后,灌注取脑,固定包埋,做石腊切片.用免疫组化方法检测大鼠海马、顶叶皮层相关基因bcl-2p53表达的变化. 结果 +15 Gx暴露后1 d可见bcl-2表达减少,p53表达增加,在暴露后3 d改变明显;7 d模拟失重组大鼠在暴露后1 d可见bcl-2表达减少,p53表达增加;模拟失重后再+15 Gx组在暴露后1 d可见上述bcl-2p53表达的变化,在暴露后3 d改变最明显,变化比+15 Gx组或模拟失重组均明显. 结论 +15 Gx/180 s暴露可引起大鼠海马和顶叶皮层细胞凋亡相关基因bcl-2p53表达的变化;7 d模拟失重可加重+Gx引起的大鼠脑组织损伤.

  7. Expression of protein encoded by apoptosis-associated gene p53, bcl-2, and bax in adaptive response of thymocyte apoptosis in mice induced by low dose radiation with X-rays

    International Nuclear Information System (INIS)

    Objective: To explore the regulative mechanism of apoptosis-associated gene proteins on the adaptive response of thymocyte apoptosis in mice induced by low dose radiation with X-rays. Methods: Kunming male mice were irradiated with the inductive doses (D1: 25, 50, 75, 100 and 200 mGy; dose rate: 12.5 mGy ·min-1) and the challenging dose (D2: 1.5 Gy; dose rate: 287 mGy·min-1). The time interval between D1 and D2 was 6 h. The expressive levels of thymocyte apoptosis-associated gene proteins were measured with flow cytometry. Results: As compared with the sham-irradiation, the positive percentage of thymocyte Bcl-2 protein expression decreased significantly in D2 group (P<0.05), Bax increased significantly (P<0.05), and Bcl-2/Bax decreased significantly (P<0.001); p 53 increased significantly (P<0.001). As compared with D2 group, the positive percentage of thymocyte Bcl-2 protein expression increased in varying degree in D1+ D2 group of 25-75 mGy D1, Bax decreased in varying degree, and Bcl-2/Bax increased significantly (P<0.01); p53 decreased significantly (P<0.001 or P<0.05). Conclusion: The apoptotic thymocytes in the adaptive response of thymocyte apoptosis in mice induced by irradiation with 25-75 mGy decrease significantly due to the increase of apoptosis-associated gene Bcl-2 protein expression and Bcl-2/Bax, the decrease of Bax and p53 protein expressions. (authors)

  8. Correlation of apoptosis genes of p53 ,bcl-2 and bax in tissue of prostate%凋亡相关基因p53bcl-2、bax在前列腺组织中的相关性

    Institute of Scientific and Technical Information of China (English)

    方志启; 吴刚; 王贺彬; 陈晓宇

    2013-01-01

    目的 探讨细胞凋亡相关基因p53bcl-2、bax在前列腺组织中的相关性.方法 收集36例前列腺癌(prostate caner,PCa)、20例前列腺增生(benign prostatic hyperplasia,BPH)和11例正常前列腺(normal prostatic,NP),应用免疫组织化学S-P法检测凋亡相关基因p53bcl-2、bax蛋白的表达.结果 ①PCa和BPH组bcl-2蛋白阳性表达率明显高于NP组(P>0.05),而PCa组与BPH组阳性率差异无显著性.PCa组p53蛋白阳性表达率明显高于BPH组和NP组(P<0.01),而BPH组与NP组阳性率无显著性 差异(P>0.05).②p53与PCa分级有关,随着肿瘤分级增高而呈正相关(P<0.05); bcl-2与PCa分级有关,随着肿瘤分级增高而呈正相关(P<0.01),显示bcl-2、p53蛋白表达随着病理分级的增高而增高.PCa、BPH 和NP中bax阳性表达率差异无显著性.③p53蛋白表达阳性率≤5年生存组明显高于>5年生存组,呈负相关(P<0.05);bcl-2、bax蛋白表达与生存期无关(P>0.05).结论 细胞凋亡相关基因p53bcl-2、bax蛋白的异常表达与PCa的发生和发展、病理分级和预后有相关性.

  9. Expressions of bcl-2 and P53 protein in Bowen's disease%Bowen病bcl-2P53蛋白的表达

    Institute of Scientific and Technical Information of China (English)

    张士发; 王良明; 赵丽萍; 许静; 顾绍裘

    2004-01-01

    目的:探讨bcl-2P53蛋白在Bowen病及Bowen样鳞癌中的表达及其意义.方法:应用免疫组织化学技术对11例Bowen病及3例Bowen样鳞癌bcl-2和/或P53蛋白的表达进行了检测.结果:11例Bowen病中bcl-2蛋白阳性2例(18%),P53蛋白阳性3例(27%);3例Bowen样鳞癌均见bcl-2蛋白表达.Bowen病中bcl-2P53蛋白表达显著正相关(r=0.769,P<0.05).结论:Bowen病中bcl-2蛋白表达与P53基因突变有关,并参与了Bowen病的进展及向Bowen样鳞癌的演变.

  10. Pathological diagnosis on natural avian leukosis cases in Hubei and the expression of p53 and Bcl-2 genes%湖北省禽白血病自然病例的病理学诊断及p53Bcl-2基因表达情况的观察

    Institute of Scientific and Technical Information of China (English)

    胡冬姣; 张丽娜; 李慧; 谷长勤; 程国富; 张万坡; 胡薛英; 周诗其

    2007-01-01

    应用组织病理学和SABC免疫组织化学技术,对湖北省武汉市的2批14日龄和33日龄疑似禽白血病肉鸡进行了病理学诊断,并观察了病鸡肝肿瘤组织中p53基因和Bcl-2基因的表达情况.剖检可见病鸡肝、肾、脾均不同程度肿胀,组织病理学检查在肝、肾、心等脏器可见散在或聚集成团的骨髓瘤细胞,胞浆内充满球形的嗜酸性颗粒;在病鸡肝肿瘤组织中p53Bcl-2基因均呈阳性表达,诊断为J亚群禽白血病(ALV-J),提示p53基因和Bcl-2基因与肉鸡J亚群禽白血病有关.

  11. Prognostic significance of bcl-2 and p53 expression in colorectal carcinoma

    Institute of Scientific and Technical Information of China (English)

    ZHAO Dan-ping; DING Xiao-wen; PENG Jia-ping; ZHENG Yi-xiong; ZHANG Su-zhan

    2005-01-01

    Objective: This study was designed to detect the expression ofbcl-2 and p53 proteins in colorectal carcinomas and to determine their association with the patient survival and stage of the diseases. Methods: Immunohistochemistry method was used to detect the expression ofbcl-2 and p53 proteins in 93 cases of colorectal carcinoma. The stain results were obtained by analyzing the clinic-pathological characteristics of patients. Results: Fifty-seven percent (53/93) of the colorectal carcinomas were bcl-2 protein positive. The positive rate of bcl-2 protein in lymph node involvement cases was lower (15/37) than the cases without node involvement (38/58, P<0.01). The positive rate of p53 protein was 43% (40/93) in colon-rectum carcinomas. No significant correlation was observed between p53 protein expression and clinic-pathological manifestations (P>0.05) but the survival was significantly worse (P=0.0001) in the p53 protein positive cases. Neither bcl-2 nor p53 alone was correlated with stage of the disease. When combined bcl-2/p53 status was analyzed, a group with bcl-2(+) and p53(-) had the best prognosis. This group was significantly associated with earlier Dukes' stages (P=0.1763). In multivariate Cox regression analysis, lymph node involvement and p53 protein expression were two independent factors correlated with survival time. Conclusion: The expression of bcl-2 and p53 represent biological characteristics of colorectal carcinomas. Assessment of both bcl-2 and p53 status may be valuable in predicting the prognosis of patients.

  12. Deregulation of apoptosis mediators' p53 and bcl2 in lung tissue of COPD patients

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    Pentilas Nikolaos

    2010-04-01

    Full Text Available Abstract Abnormal apoptotic events in chronic obstructive pulmonary disease (COPD subvert cellular homeostasis and may play a primary role in its pathogenesis. However, studies in human subjects are limited. p53 and bcl2 protein expression was measured by western blot on lung tissue specimens from 43 subjects (23 COPD smokers and 20 non-COPD smokers, using beta-actin as internal control. Additionally, p53 and bcl2 expression patterns were evaluated by immunohistochemistry in formalin-fixed, paraffin-embedded lung tissue sections from the same individuals. Western blot analysis showed statistically significant increased p53 protein levels in COPD smokers in comparison with non-COPD smokers (p = 0.038, while bcl2 protein levels were not statistically different between the two groups. Lung immunohistochemistry showed increased ratio of positive p53-stained type II pneumocytes/total type II pneumocytes in COPD smokers compared to non-COPD smokers (p = 0.01, whereas the p53 staining ratio in alveolar macrophages and in lymphocyte-like cells did not differ statistically between the two groups. On the other hand, bcl2 expression did not differ between the two groups in all three cell types. The increased expression of pro-apoptotic p53 in type II pneumocytes of COPD patients not counterbalanced by the anti-apoptotic bcl2 could reflect increased apoptosis in the alveolar epithelium of COPD patients. Our results confirm previous experiments and support the hypothesis of a disturbance in the balance between the pro- and anti-apoptotic mediators in COPD.

  13. Expression of caspase-3, p53 and Bcl-2 in generalized aggressive periodontitis

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    Özdemir B Handan

    2006-06-01

    Full Text Available Abstract Background Apoptosis, or programmed cell death is a form of physiological cell death. It is increased or decreased in the presence of infection, inflammation or tissue remodelling. Previous studies suggest that apoptosis is involved in the pathogenesis of inflammatory periodontal disease. The aim of the present study was to investigate the clinical features and known indicators of apoptosis (p53, Bcl-2, Caspase-3 in patients with generalized aggressive periodontitis (GAP Methods Eight patients with GAP, who had sites with probing depths (PD > 5 mm, and 10 periodontally-healthy persons were included in the study. Clinical examinations and PD were performed, and the plaque index and gingival index were recorded. Gingival tissues biopsies were obtained from active site of each patient and from healthy individuals. The expression of caspase-3, Bcl-2, and p53 was evaluated by immunohistochemistry Results There were no significant differences between GAP and control group with respect to levels of caspase-3 and p53 expression (P > 0.05. Contrary, the frequency of grade 3 expression of Bcl-2 was higher in GAP group than the control group. Conclusion The higher frequency of Bcl-2 expression in GAP group indicates and delayed apoptosis can lead to increasing resident inflammatory cells in periodontal tissues and resulting in progressive periodontal destruction.

  14. p53 Nuclear Accumulation and Bcl-2 Expression in Contiguous Adenomatous Components of Colorectal Adenocarcinomas Predict Aggressive Tumor Behavior

    OpenAIRE

    Shanmugam, Chandrakumar; Katkoori, Venkat R.; Jhala, Nirag C.; Grizzle, William E.; Gene P Siegal; Manne, Upender

    2008-01-01

    For subsets of colorectal adenocarcinoma (CRC) patients, nuclear accumulation of p53 (p53nac) and Bcl-2 expression are prognostic indicators. To understand their role in the progression of CRC we evaluated 90 CRCs and their contiguous adenomatous components (CAdCs) for immunohistochemical expression of these markers. In general, p53nac and Bcl-2 expression was significantly increased when comparing normal colonic epithelia to CAdCs and CRCs. Thirteen (14%) CAdCs that demonstrated p53nac conti...

  15. EXPRESSIONS OF P53, PROLIFERATING CELL NUCLEAR ANITIGEN, BCL-2 PROTEIN AND THEIR SIGNIFICANCE IN SALIVARY ADENOID CYSTIC CARCINOMA

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective To study the effects of P53, PCNA, Bcl-2 protein and their relationship in salivary adenoid cystic carcinoma(SACC). Methods These proteins were examined by immunohistochemistry. Results Overexpressions of P53 and PCNA were revealed in ACC samples, they were higher than those in (polymorphous adenomas) PA, but expression of Bcl-2 protein was not different between ACC and PA. In 3 subtypes of ACC, expressions of 3 proteins were different. Conclusion Mutations of P53, Bcl-2 may be involed in the occurrence of SACC, expression of PCNA and mutation of P53 may coexist in the development of the SACC.

  16. HAMLET triggers apoptosis but tumor cell death is independent of caspases, Bcl-2 and p53.

    Science.gov (United States)

    Hallgren, O; Gustafsson, L; Irjala, H; Selivanova, G; Orrenius, S; Svanborg, C

    2006-02-01

    HAMLET (Human alpha-lactalbumin Made Lethal to Tumor cells) triggers selective tumor cell death in vitro and limits tumor progression in vivo. Dying cells show features of apoptosis but it is not clear if the apoptotic response explains tumor cell death. This study examined the contribution of apoptosis to cell death in response to HAMLET. Apoptotic changes like caspase activation, phosphatidyl serine externalization, chromatin condensation were detected in HAMLET-treated tumor cells, but caspase inhibition or Bcl-2 over-expression did not prolong cell survival and the caspase response was Bcl-2 independent. HAMLET translocates to the nuclei and binds directly to chromatin, but the death response was unrelated to the p53 status of the tumor cells. p53 deletions or gain of function mutations did not influence the HAMLET sensitivity of tumor cells. Chromatin condensation was partly caspase dependent, but apoptosis-like marginalization of chromatin was also observed. The results show that tumor cell death in response to HAMLET is independent of caspases, p53 and Bcl-2 even though HAMLET activates an apoptotic response. The use of other cell death pathways allows HAMLET to successfully circumvent fundamental anti-apoptotic strategies that are present in many tumor cells.

  17. Effect of low dose radiation on P53 and Bcl-2 protein expression in spermatogenic cells of mouse testis

    International Nuclear Information System (INIS)

    Objective: To investigate the effect of low dose radiation (LDR) with different dose of X-rays on P53 and Bcl-2 protein expression in spermatogenic cells of male Kunming mouse testis. Methods: The relationships between time-effect and dose-effect of P53 and Bcl-2 protein expression positive rate in spermatogenic cells of mouse testis after LDR with different dose of X-rays were studied with immunohistochemical technique (SABC). Results: P53 and Bcl-2 protein expressed in spermatogonia and spermatocytes in varying degrees, the positive rate of spermatogonia was obviously superior to that of spermatocytes. With the increase of irradiation dose, the expression of P53 protein showed a increasing tendency, however, the P53 protein expression of spermatozoa scarcely occurred after LDR. Bcl-2 protein was primarily expressed in spermatozoa. With the increase of irradiation dose, the positive rate of Bcl-2 protein expression showed a downregulated tendency. However, the Bcl-2 protein expression of spermatogonia and spermatocytes scarcely occurred after LDR. Conclusion: The expressions of P53 and Bcl-2 may have regular changes in mouse testis induced by LDR, which may provide a experimental evidence for the mechanism study of spermatogonic cell apoptosis induced selectively by ionizing radiation

  18. Correlations in survivin expression with the expression of p53 and bcl-2 in invasive ductal carcinoma of the breast.

    Science.gov (United States)

    Al-Joudi, F S; Iskandar, Z A; Imran, A K

    2007-09-01

    This work studied the correlations between survivin, bcl-2 and p53 in infiltrating ductal carcinoma of the breast. A total number of 382 cases were collected from 3 hospitals in northeastern Malaysia. Survivin, bcl-2 and p53 were detected by immunohistochemistry on samples prepared from tissue blocks. Significant correlations were found between tumor histological grades and tumor size and lymph node involvement. Highly significant statistical correlations (pfashion, implying that many of these cases may share common abnormalities. PMID:18041310

  19. The Expresstional Differences and Developmental Changes of bcl-2,P53 Gene in Early Embryos of Generic Hybrids of Chicken-Quail%鸡与鹌鹑属间杂交早期胚胎bcl-2P53基因表达的差异及发育性变化

    Institute of Scientific and Technical Information of China (English)

    乔爱君; 李大全; 马文霞; 廖和荣; 李岩; 赵宗胜

    2008-01-01

    [目的]探讨细胞凋亡因子bc1-2.P53对鸡与鹌鹑属间杂交早期胚胎发育的影响.[方法]人工授精获得鸡(♂)与鹌鹑(♀)杂交种蛋,按照鸡标准孵化条件同批入孵,随机采集66、72、78、84、90,96、102、108,114、120 h活胚.采用RT-PCR方法,用Wpkci和β-actin 引物进行多重PCR鉴定胚胎样本性别,后选取各时间点雌、雄胚胎各4枚,以β-actin为内标,测定bc1-2、P53的mRNA相对丰度.[结果](1)雄性胚胎66~114 h bc1-2mRNA表达维持在较低水平,96 h有所降低,随后回升到原水平,120 h极显著升高(P<0.01),达到峰值;雌性胚胎66~114 h bc1-2 mRNA表达维持在较低水平,114 h极显著升高(P<0.01),此后维持在较高水平,120 h达到峰值.不同日龄之间的比较,114 h雌性表达显著高于雄性(P<0.05);(2)雌、雄胚胎P53mRNA发育性表达模式基本一致.66 h表达水平较高,72 h表达降低,达到低谷,雄性达到显著(P<0.05),雌性整体差异不显著,随后上升维持在原水平;不同日龄之间表达差异不显著.[结论]114 h雌性胚胎bc1-2mRNA表达高峰点与其P53 bc1-2表达最低水平相吻合;72 h雌、雄胚胎P53mRNA表达与P53bc1-2表达水平一致,处于低谷点;72、114 h早期杂交胚胎bc1-2,P53基因表达出现异常.

  20. 甲状腺癌组织中P53Bcl-2和TPO的表达及临床意义%Expression and significance of p53Bcl-2 and TPO in thyroid carcinoma

    Institute of Scientific and Technical Information of China (English)

    熊少伟; 王玲; 赵洋; 雷云鹏; 刘铮

    2011-01-01

    Objective: To study the significance of the examination at the same time of Bcl—2 NP53 and TPO in thyroid tumor. Methods: The Expression of Bcl-2, P53 and TPO was analyzed by immunohistochemical LSAB method in the tissues from 77 thyroid carcinomas, 58 thyroid adenomas, 40 thyroid tissues adjacent to cancer and 28 normal thyroid tissues. The positive expression rates in the different thyroid tissues were compared. Results: Bcl—2 and P53 were expressed in thyroid carcinoma, thyroid adenoma, the thyroid tissues adjacent to cancer and non in normal thyroid tissues. The positive expression rate of Bcl—2,P53 in the thyroid carcinoma was significantly higher than that of in thyroid adenoma, thyroid tissues adjacent to cancer and normal thyroid tissues. The results were retrospectively analysed relative to the out—come of patients on follow up. It was shown that Bcl—2, TPO and PS3 immunoreaction were closely associated with histological types, pathological typing. It was found that positive Bcl—2 and P53 was in remarkable positively correlated with high re- current rates of patients. Conclusion: The results suggest that over-expression of Bcl—2 and P53 play an important role in occurrence of thyroid carcinoma and would serve as objective indicator of poor prognosis of thyroid carcinoma.%目的:探讨Bcl-2P53和TPO在甲状腺肿瘤中表达的意义.方法:应用免疫组化LSAB法,以单克隆抗体鼠抗人Bcl-2P53和TPO标记检测77例甲状腺癌、58例甲状腺腺瘤、40例癌旁甲状腺组织和28例正常甲状腺组织,观察不同甲状腺组织中Bcl-2P53和TPO的表达,并比较其阳性率.结果:Bcl-2P53阳性反应见于甲状腺癌、甲状腺腺瘤及癌旁甲状腺组织.在甲状腺癌组织中Bcl-2P53阳性率高于甲状腺腺瘤组织、癌旁甲状腺组织和正常甲状腺组织.Bcl-2P53及TPO表达与甲状腺组织类型及肿瘤病理分型密切相关,显示甲状腺癌中Bcl-2P53表达呈正相关关系.结论:Bcl

  1. Prognostic evaluation of CD44 expression in correlation with bcl-2 and p53 in colorectal cancer

    OpenAIRE

    Peros, G; Elemenoglou, I.; G. Athanasas; D. Panousopoulos; A. Zizi-Sermpetzoglou; H.N. Zavrides

    2011-01-01

    To investigate the expression of CD44 in colorectal cancer and examine its association with clinicopathological features, bcl-2, p53 and long-term outcome, paraffin-embedded tumour specimens from 61 patients with Dukes stage B (AJCC/UICC stage I) and 39 patients with Dukes stage C (AJCC/UICC stage III) colorectal adenocarcinoma were assessed by immunohistochemistry. The expression of CD44, bcl-2 and p53 were correlated with 5-year follow-up. Low CD44 expression was present in 30%, moderate in...

  2. Prognostic evaluation of CD44 expression in correlation with bcl-2 and p53 in colorectal cancer

    Directory of Open Access Journals (Sweden)

    G. Peros

    2011-08-01

    Full Text Available To investigate the expression of CD44 in colorectal cancer and examine its association with clinicopathological features, bcl-2, p53 and long-term outcome, paraffin-embedded tumour specimens from 61 patients with Dukes stage B (AJCC/UICC stage I and 39 patients with Dukes stage C (AJCC/UICC stage III colorectal adenocarcinoma were assessed by immunohistochemistry. The expression of CD44, bcl-2 and p53 were correlated with 5-year follow-up. Low CD44 expression was present in 30%, moderate in 30% and extensive in 40% of cases. It was not related to patient sex and age but was related to tumour differentiation, stage and tumour site. No association was demonstrated between CD44 and bcl-2. However, there was significant evidence of an association between CD44 and p53 in 66 cases in which p53 was previously assessed. There was a trend towards increased survival in patients whose tumours expressed lower levels of CD44 protein. When entered into multivariate analysis model, which also included bcl-2 and p53, CD44 staining emerged as an indicator of poor prognosis in colorectal cancer patients.

  3. The expression and significance of p53 and bcl-2 in lacrimal gland epithelial neoplasms%p53bcl-2在泪腺上皮性肿瘤中表达及意义

    Institute of Scientific and Technical Information of China (English)

    王磊峰; 肖利华; 黑砚; 王毅; 杨新吉; 鲁小中

    2011-01-01

    Objective To investigate the expression of p53 and bcl-2 in normal lacrimal, benign and malignant neoplasms of lacrimal gland, to analyze relationship between above biological remarks and clinical or pathological of lacrimal tumors, to study their action in occurrence of lacriaml benign, malignant tumor and to provide evidence for differential diagnosis, therapy and prognosis estimation. Method Of 35 Pleomorphic adenoma, 28 Malignant lacrimal gland tumors and 9 normal lacrimal gland specimens were collected. The expression of p53 and bcl-2 was analyzed with immunohistochemistry in order to find the difference in the above-mentioned tissues. Results The expression of p53 and bcl-2 shows an increasing tendency from normal lacrimal to benign and malignant. Both p53 and bcl-2 expression were positive in 26 cases. Neither p53 nor bcl-2 was positive in 22 cases. These numbers were significantly higher than that single positive or monomial negative (P <0.05). Conclusions p53 and bcl-2 may involve occurrence of lacrimal epithelial tumors and may be a biological remark of identifying normal lacrimal gland, lacrimal benign or malignant tumor. p53 and bcl-2seems to participate in occurring of lacrimal malignant tumors and be biological parameters which identify malignant from benign lacrimal gland. This study indicates that p53 and bcl-2 play important roles in lacrimal gland epithelial neoplasms. They are co-operative factors in the process of occurrence and development of lacrimal gland adenoid cystic carcinoma.%目的 通过观察p53bcl-2在泪腺良、恶性肿瘤中表达情况,分析其与泪腺良、恶性肿瘤的临床和组织病理的关系.目的在于进一步探明它们在泪腺良、恶性肿瘤发生、发展中的作用,为泪腺良、恶性肿瘤的鉴别诊断、治疗以及预后判断提供依据.方法 收集手术切除35例泪腺多形性腺瘤,28例泪腺腺样囊性癌,并取手术中切除的正常泪腺组织9例作为正常对照.应用免疫组化检测p

  4. Nitric oxide and oxygen radicals induced apoptosis via bcl-2 and p53 pathway in hypoxia-reoxygenated cardiomyocytes

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Neonatal rat cardiomyocytes were subjected to 24 h of hypoxia 95%N2/5%CO2 and 24 h of hypoxia plus 4 h of reoxygenation 95%O2/5%CO2. 24 h of hypoxia increased the levels of NO, TBARS and LDH. 24 h of hypoxia plus 4 h of reoxygenation decreased the levels of NO, but further increased TBARS and LDH. The hypoxia up-regulated the expression of bcl-2, p53 and p21/waf1/cip1 but the reoxygenation down-regulated the expression of bcl-2, and further up-regulated p53 and p21/waf1/cip1. The hypoxia increased cell apoptosis and reoxygenation further increased both apoptotic and necrotic cell death. NO, TBARS, DNA fragmentation and cell apoptosis were enhanced by SNP and inhibited by L-NAME respectively. In addition, SOD/catalase down-regulated the expression of p53, p21/wafl/cipl and TBARS but up-regulated bcl-2 and increased indirectly the level of NO, and inhibited DNA fragmentation. The results suggest that hypoxia-induced cell death is associated with the activation of NO, bcl-2 and p53 pathway, while hypoxia-reoxygenation induced cell death via the generation of reactive oxygen species and activation of p53 pathway. The present study clarified that NO may be an initiative signal to apoptotic cell death and the activation of bcl-2, p53 and p21/waf1/cip1 pathway in hypoxic and hypoxia-reoxygenated cardiomyocytes.

  5. BaP-induced DNA damage initiated p53-independent necroptosis via the mitochondrial pathway involving Bax and Bcl-2.

    Science.gov (United States)

    Jiang, Y; Chen, X; Yang, G; Wang, Q; Wang, J; Xiong, W; Yuan, J

    2013-12-01

    Benzo(a)pyrene (BaP), a typical environmental carcinogen, can induce cell death both by protein 53 or tumor protein 53 (p53)-independent and -dependent pathways. However, little is known about the molecular mechanisms of p53-independent pathways in BaP-induced cell death. In this study, cells with different genetic background (including p53-proficient human fetal lung fibroblast cell lines (MRC-5), p53-deficient human non-small-cell lung carcinoma cell lines (H1299), and p53-knockdown cell lines (MRC-5(p53-/-))) were used to establish models of BaP-induced cell death. The results showed that BaP (8, 16, 32, and 64 μM) induced necroptotic cell death in the cell lines. The necroptotic cell death and DNA damage were concurrently observed. In the three cell lines, at 24 h after treatment, BaP (8-64 μM) upregulated expressions of BAX, BCL-2, and cleaved caspase-3 proteins, but not their messenger RNA levels. The findings suggested that BaP-induced necroptosis was modulated by the p53-independent pathway, which was related to the induction of BAX, decreased expression of BCL-2, and activation of caspase-3.

  6. Expression of P53 and PCNA and bcl-2 and EGFR in patients with multiple primary bladder cancers%多原发膀胱癌中P53、PCNA、bcl-2、EGFR表达的研究

    Institute of Scientific and Technical Information of China (English)

    祝庆亮; 谷江; 石家齐; 孙发; 龙义国; 沈俊; 张永春; 万滨; 杨永安

    2012-01-01

    目的:研究P53、PCNA、bcl-2、EGFR在多原发膀胱癌与单发膀胱癌中的表达情况,探讨其意义及价值,为临床诊断、鉴别诊断及靶向治疗多原发膀胱癌提供依据.方法:运用免疫组化方法检测1996年~2011年间收治并经病理检查确诊的多原发膀胱癌标本15例、单发膀胱癌标本15例(临床分期、病理分级与多原发膀胱癌相同)、正常膀胱组织15例中P53、PCNA、bcl 2、EGFR的表达情况,比较其阳性表达率及程度的差异.结果:多原发膀胱癌及单发膀胱癌中P53、PCNA、bcl-2、EGFR阳性表达均高于正常膀胱组织(P<o.05),多原发膀胱癌中P53bcl-2阳性表达高于单发膀胱癌(P<0.05),多原发膀胱癌中EGFR阳性表达低于单发膀胱癌(P<0.001),多原发膀胱癌中PCNA阳性表达与单发膀胱癌差异无统计学意义(P>0.05).结论:多原发膀胱癌与单发膀胱癌中P53bcl 2、EGFR表达有差异性(P<0.05),P53bcl-2高表达而EGFR低表达见于多原发膀胱癌,联合检测P53bcl-2、EGFR在诊断和鉴别诊断多原发膀胱癌中有一定临床价值.EGFR在多原发膀胱癌中的表达明显高于正常膀胱组织(P<0.001),这为靶向治疗多原发膀胱癌提供了可能.%Objective:To study the expression and clinical features of P53, PCNA, bcl-2 and EGFR in multiple primary bladder cancers and bladder cancers, and provide evidence for diagnosis and target treatment for multiple primary bladder cancers. Methods: Immunohistochemical SP methods were used to detect the expression of P53 and PCNA and bcl-2 and EGFR in 15 patients with multiple primary bladder cancers, 15 patients with bladder cancers (The clinical stage and pathological grade of patients with bladder cancers were similar to those with multiple primary bladder cancers) and 15 patients with normal bladders, the differences from expressions of P53, PCNA, bcl-2 and EGFR in each group were analysed. All the patients have been treated during from

  7. Expression of P53, P21/WAF/CIP, BCL-2, BAX, BCL-X, and BAK in radiation-induced apoptosis in testicular germ cell tumor lines

    International Nuclear Information System (INIS)

    Purpose: Testicular germ cell tumors (TGCTs) represent one of the few tumor types that are curable by antineoplastic therapy, probably due to the high sensitivity of this neoplasm to induction of apoptosis by chemotherapeutic agents and/or ionizing radiation. Here, we tested cell susceptibility to radiation-induced apoptosis in a panel of TGCT cell lines and attempted to correlate this with the known potentially relevant molecular determinants (p53 gene status and Bcl-2 family proteins) of apoptosis. Methods and Materials: Induction of apoptosis by γ-radiation was morphologically recognized in NT2, NCCIT, S2, and 2102 EP using Hoechst/PI staining and additionally confirmed by Western blot analysis of PARP cleavage. The p53 gene status was estimated by sequence analysis. Expression of p21/WAF/CIP was determined by Northern blot analysis and immunoblotting was used to monitor p53, Bax, Bcl-2, Bcl-x, and Bak protein levels. In vitro colony formation was studied to establish clonogenic survival curves. Results: NT2 and NCCIT appeared to be susceptible for radiation-induced apoptosis, contrasting 2102 EP and S2 which were highly resistant. Sequence analysis showed that NT2, S2, and 2102 EP are homozygous for wild-type p53 (wtp53), whereas NCCIT contains mutant p53 (mtp53). NT2 and 2102 EP cells showed radiation-induced p53 upregulation, while NCCIT (mtp53) and S2 (no p53 protein) cells did not. Consistently, γ-radiation-induced DNA damage resulted in a p53-dependent transactivation of the p21/WAF/CIP gene in NT2 and 2102 EP, but not in mtp53-containing NCCIT cells and p53 nonexpressing S2 cells. Constitutive expression of Bax, Bcl-2, Bcl-x, and Bak was not affected by radiation and showed no correlation with cell susceptibility to radiation-induced apoptosis. A discrepancy was found between apoptosis and reproductive death. Conclusions: The present study revealed that: i) the presence of wtp53 may not be absolutely required for the hypersensitivity for radiation

  8. Expression of p53, Bax and Bcl-2 proteins in hepatocytes in non-alcoholic fatty liver disease

    Institute of Scientific and Technical Information of China (English)

    Anatol Panasiuk; Janusz Dzieciol; Bozena Panasiuk; Danuta Prokopowicz

    2006-01-01

    AIM: To analyze the protein expression essential for apoptosis in liver steatosis.METHODS: The expression of proapoptotic proteinsp53, Bax, and antiapoptotic Bcl-2 in hepatocytes with steatosis (SH) and without steatosis (NSH) was evaluated in 84 patients at various stages of non-alcoholic fatty liver disease (NAFLD).RESULTS: Immunohistochemical staining of liver tissue showed the activation of p53 protein in SH and NSH with increased liver steatosis, diminished Bcl-2 and slightly decreased Bax protein. Positive correlation was found between the stage of liver steatosis with p53 expression in SH (r = 0.54, P < 0.01) and NSH (r = 0.49,P < 0.01).The antiapoptotic protein Bcl-2 was diminished together with the advancement of liver steatosis, especially in non-steatosed hepatocytes (r =0.43, P < 001).CONCLUSION: Apoptosis is one of the most important mechanisms leading to hepatocyte elimination in NAFLD. The intensification of inflammation in NAFLD induces proapoptotic protein p53 with the inhibition of antiapoptotic Bcl-2.

  9. Effects of folic acid on epithelial apoptosis and expression of Bcl-2 and p53 in premalignant gastric lesions

    Institute of Scientific and Technical Information of China (English)

    Da-Zhong Cao; Wei-Hao Sun; Xi-Long Ou; Qian Yu; Ting Yu; You-Zhen Zhang; Zi-Ying Wu; Qi-Ping Xue; Yun-Lin Cheng

    2005-01-01

    AIM: To evaluate the effects of folic acid on epithelial apoptosis and expression of Bcl-2 and p53 in the tissues of premalignant gastric lesions.METHODS: Thirty-eight patients, with premalignant gastric lesions including 18 colonic-type intestinal metaplasia(IM)and 20 mild or moderate dysplasia, were randomly divided into a treatment group (n = 19) receiving folic acid 10 mg thrice daily and a control group (n = 19) receiving sucralfate 1 000 mg thrice daily for 3 mo. All patients undervvent endoscopies and four biopsies were taken prior to treatment and repeated after concluding therapy.Folate concentrations in gastric mucosa were measured with chemiluminescent enzyme immunoassay. Epithelial apoptosis and the expression of Bcl-2 and p53 protein in gastric mucosa were detected with flow cytometric assay.RESULTS: The mean of folate concentration in gastric mucosa was 9.03±3.37 μg/g wet wt in the folic acid treatment group, which was significantly higher than 6.83±3.02 μg/g wet wt in the control group. Both the epithelial apoptosis rate and the tumor suppressor p53expression in gastric mucosa significantly increased after folic acid treatment. In contrast, the expression of Bcl-2oncogene protein decreased after folic acid therapy.CONCLUSION: These data indicate that folic acid may play an important role in the chemoprevention of gastric carcinogenesis by enhancing gastric epithelial apoptosis in the patients with premalignant lesions.

  10. Bcl-2 protein expression is associated with p27 and p53 protein expressions and MIB-1 counts in breast cancer

    Directory of Open Access Journals (Sweden)

    Nishizaki Takashi

    2006-07-01

    Full Text Available Abstract Background Recent experimental studies have shown that Bcl-2, which has been established as a key player in the control of apoptosis, plays a role in regulating the cell cycle and proliferation. The aim of this study was to investigate the relationship between Bcl-2 and p27 protein expression, p53 protein expression and the proliferation activity as defined by the MIB-1 counts. The prognostic implication of Bcl-2 protein expression in relation to p27 and p53 protein expressions and MIB-1 counts for breast cancer was also evaluated. Methods The immunohistochemical expression of Bcl-2 protein was evaluated in a series of 249 invasive ductal carcinomas of the breast, in which p27 and p53 protein expressions and MIB-1 counts had been determined previously. Results The Bcl-2 protein expression was found to be decreased in 105 (42% cases. A decreased Bcl-2 protein expression was significantly correlated with a nuclear grade of III, a negative estrogen receptor, a decreased p27 protein expression, a positive p53 protein expression, positive MIB-1 counts and a positive HER2 protein expression. The incidence of a nuclear grade of III and positive MIB-1 counts increased as the number of abnormal findings of Bcl-2, p27 and p53 protein expressions increased. A univariate analysis indicated a decreased Bcl-2 protein expression to be significantly (p = 0.0089 associated with a worse disease free survival (DFS, while a multivariate analysis indicated the lymph node status and MIB-1 counts to be independently significant prognostic factors for the DFS. Conclusion The Bcl-2 protein expression has a close correlation with p27 and p53 protein expressions and the proliferation activity determined by MIB-1 counts in invasive ductal carcinoma of the breast. The prognostic value of Bcl-2 as well as p27 and p53 protein expressions was dependent on the proliferation activity in breast cancer.

  11. Prognostic significance of CD95, P53, and BCL2 expression in extranodal non-Hodgkin's lymphoma

    OpenAIRE

    Chatzitolios, Anastasios; Venizelos, Ioannis; Tripsiannis, Gregory; Anastassopoulos, George; Papadopoulos, Nikolaos

    2010-01-01

    Abstract Apoptosis-related proteins play an important role in lymphoma cell death during chemotherapy. In our study, we investigated the prognostic significance of CD95, BCL2, and P53 expression in extranodal non-Hodgkin?s lymphoma (NHL). We examined 71 patients with extranodal NHL [45 diffuse large B-cell lymphomas (DLBCLs) and 26 mucosa-associated lymphoid tissue lymphomas (MALTLs)], 35 male and 36 female, with a median age of 65.8 years. The most common site of origin was the st...

  12. Immunohistochemical expression of p53, BCL-2, BAX and VEGFR1 proteins in nephroblastomas A expressão imuno-histoquímica das proteínas p53, BCL-2, BAX e VEGFR1 em nefroblastomas

    Directory of Open Access Journals (Sweden)

    Ana Paula Percicote

    2013-02-01

    Full Text Available INTRODUCTION: Nephroblastoma or Wilms' tumor is the most frequent renal cancer in children. Although its prognosis is favorable for most patients, it may relapse or have a fatal outcome. The characterization of risk groups by applying immunohistochemical biomarkers aims to adapt the treatment to its corresponding group as well as to reduce relapses and fatal outcome. p53, B-cell lymphoma 2 (BCL-2, BCL-2 associated protein X (BAX and vascular endothelial growth factor receptor 1 (VEGFR1 are among the most widely studied biomarkers, which are related to the apoptotic pathway, DNA repair and neovascularization. OBJECTIVE: The objective of this study is to assess the immunohistochemical expression of p53, BCL-2, BAX and VEGFR1 in samples of human nephroblastoma and to correlate them with clinicopathological prognostic factors. MATERIAL AND METHODS: Twenty-nine surgical specimens of nephroblastoma diagnosed from 1994 to 2007 were selected from the Anatomopathological Service of two hospitals in Curitiba. The immunohistochemical analysis of tissue microarrays was performed through immunoperoxidase staining and the yielded results were compared with clinicopathological prognostic factors. RESULTS: The major immunohistochemical expression of VEGFR1 in blastema and epithelium presented positive association with the risk group. Hence this may be related to higher vascular neoplastic invasion apparently caused by the endothelial growth factor, which maximizes the chances of metastasis and ultimately changes tumor staging, risk group and clinical evolution. CONCLUSIONS: The immunohistochemical expression of VEGFR1 substantiated a directly proportional association with the nephroblastoma risk group.INTRODUÇÃO: O nefroblastoma, ou tumor de Wilms, é a neoplasia renal mais frequente na infância. Embora o prognóstico seja favorável para a maioria dos pacientes, muitos evoluem para recidiva ou óbito. A caracterização de grupos de risco por meio de

  13. Impact of BCL2 and p53 on postmastectomy radiotherapy response in high-risk breast cancer. A subgroup analysis of DBCG82 b

    DEFF Research Database (Denmark)

    Kyndi, M.; Sorensen, F.B.; Alsner, J.;

    2008-01-01

    Purpose. To examine p53 and BCL2 expression in high-risk breast cancer patients randomized to postmastectomy radiotherapy (PMRT). Patients and methods. The present analysis included 1000 of 3 083 high-risk breast cancer patients randomly assigned to PMRT in the DBCG82 b&c studies. Tissue microarray...... randomization status. Significant reductions in LRR probability after PMRT were recorded within both the BCL2 positive and BCL2 negative subgroups. Conclusion. p53 was not associated with survival after radiotherapy in high-risk breast cancer, but BCL2 might be Udgivelsesdato: 2008...... sections were stained with immunohistochemistry for p53 and BCL2. Median potential follow-up was 17 years. Clinical endpoints were locoregional recurrence (LRR), distant metastases (DM), overall mortality, and overall survival (OS). Statistical analyses included Kappa statistics, chi(2) or exact tests...

  14. Homologous recombination in mammalian cells: effect of p53 and Bcl-2 proteins, replication inhibition and ionizing radiations

    International Nuclear Information System (INIS)

    The control of cell cycle, associated with the mechanisms of replication, DNA repair/recombination allows the cells to maintain their genetic integrity. The p53 protein ensures the control of G1/S transition. Its inactivation would allow to initial replication on damaged matrix and lead to the block of replication forks followed by DNA strand breaks, good substrates for recombination. This work shows that the expression of mutant p53 protein stimulates both spontaneous and radio-induced homologous recombination, independently of the control of cell cycle. Moreover, the use of a set of replication inhibitors show that inhibition of the replication elongation stimulates recombination more strongly than the initiation inhibition. Replication arrest by these inhibitors also significantly increases the number of DNA strand breaks. These results highlighted a point of action of p53 protein on the ultimate stages of the homologous recombination mechanism. Lastly, the expression of Bcl-2 protein inhibits apoptosis and increases survival, but specifically inhibits conservative recombination, after radiation as well as in absence of apoptotic stress. The extinction of this mechanism of DNA repair is associated with an increase of mutagenesis. Taken together, these results allow ta consider the maintenance of the genetic stability as a cellular network involving different pathways. A multiple stages model for tumoral progression can be deduced. (author)

  15. Relationship between somatostatin receptor subtype expression and clinicopathology, Ki-67, Bcl-2 and p53 in colorectal cancer

    Institute of Scientific and Technical Information of China (English)

    Cheng-Zhi Qiu; Chuan Wang; Zhong-Xin Huang; Shi-Ze Zhu; You-Yi Wu; Jian-Long Qiu

    2006-01-01

    AIM: To study the SSTR1, 2, 3, 4, 5 expression and their relationships with clinico-pathological factors, cell proliferation, Bcl-2 and p53 expression in colorectal cancer cells.METHODS: Immunohistochemical staining of five SSTR subtypes, Ki-67, Bcl-2 and p53 was performed by the standard streptavidin-peroxidase (SP) technique for the paraffin sections of 127 colorectal cancers. and expression of five SSTR subtypes in 40 specimens of normal colorectal mucosae was detected with the same method. RESULTS: Positive staining for five SSTR subtypes was observed in colorectal cancer cells and normal colorectal mucosae. SSTR1 was the most predominant subtype in both colorectal cancer and normal colorectal mucosa,and the second was SSTR5 or SSTR2. As compared with normal colorectal mucosa, SSTR4 was more frequently expressed in colorectal cancer cells (2.5% vs 18.9%,P< 0.05); the expression of SSTR2, 4, 5 in moderately to well differentiated colorectal adenocarcinoma was significantly higher than that in poorly differentiated ones (P< 0.05), the SSTR1 expression in colorectal cancer with positive lymph node metastasis was significantly higher than that with negative lymph node metastasis (72.2% and 54.5%, P< 0.05). In addition, in the ulcerative type of colorectal cancer, SSTR2 expression was obviously decreased (P < 0.05); the correlation did not reach a statistical significance between the five SSTR subtypes expression and Dukes'stages (P> 0.05), but the frequency of SSTR1 expression increased with Dukes'stage, while SSTR3 and SSTR5 expression decreased with Dukes' stage. Moreover, there was no correlation between expression of the five SSTR subtypes and other clinicopathological factors such as age, sex, tumor site,tumor depth, distant metastasis. The proliferative indexes in colorectal cancer cells with negative expression of SSTR2 and SSTR3 were significantly higher than that with positive expression (P<0.05). The Bcl-2 expression in colorectal cancer cells

  16. Susceptibility of striatal neurons to excitotoxic injury correlates with basal levels of Bcl-2 and the induction of P53 and c-Myc immunoreactivity.

    Science.gov (United States)

    Liang, Zhong-Qin; Wang, Xiao-Xia; Wang, Yumei; Chuang, De-Maw; DiFiglia, Marian; Chase, Thomas N; Qin, Zheng-Hong

    2005-11-01

    The present studies evaluated the potential contribution of Bcl-2, p53, and c-Myc to the differential vulnerability of striatal neurons to the excitotoxin quinolinic acid (QA). In normal rat striatum, Bcl-2 immunoreactivity (Bcl-2-i) was most intense in large aspiny interneurons including choline acetyltransferase positive (CAT+) and parvalbumin positive (PARV+) neurons, but low in a majority of medium-sized neurons. In human brain, intense Bcl-2-i was seen in large striatal neurons but not in medium-sized spiny projection neurons. QA produced degeneration of numerous medium-sized neurons, but not those enriched in Bcl-2-i. Many Bcl-2-i-enriched interneurons including those with CAT+ and PARV+ survived QA injection, while medium-sized neurons labeled for calbindin D-28K (CAL D-28+) did not. In addition, proapoptotic proteins p53-i and c-Myc-i were robustly induced in medium-sized neurons, but not in most large neurons. The selective vulnerability of striatal medium spiny neurons to degeneration in a rodent model of Huntington's disease appears to correlate with their low levels of Bcl-2-i and high levels of induced p53-i and c-Myc-i. PMID:15922606

  17. p53 gene mutations, p53 protein accumulation and compartmentalization in colorectal adenocarcinoma.

    OpenAIRE

    Bosari, S.; Viale, G.; Roncalli, M; Graziani, D.; Borsani, G; Lee, A. K.; Coggi, G.

    1995-01-01

    p53 accumulation may occur in the nucleus and/or cytoplasm of neoplastic cells. Cytoplasmic accumulation has been reported to be an unfavorable, but not established, prognostic indicator in colorectal cancer. Different types of p53 intracellular compartmentalization could depend either on p53 gene mutations or on the interaction with p53 protein ligands. The purposes of our study were (1) to assess whether the different patterns of p53 accumulation are selectively associated with p53 mutation...

  18. Expression of beclin 1 in primary salivary adenoid cystic carcinoma and its relation to Bcl-2 and p53 and prognosis

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, L.C.; Huang, S.Y.; Zhang, D.S.; Zhang, S.H.; Li, W.G.; Zheng, P.H.; Chen, Z.W. [Shandong Provincial Hospital Affiliated to Shandong University, Department of Oral and Maxillofacial Surgery, Jinan, China, Department of Oral and Maxillofacial Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan (China)

    2014-03-03

    Beclin 1 plays a critical role in autophagy and functions as a haploinsufficient tumor suppressor. The expression and prognostic significance of beclin 1 in head and neck adenoid cystic carcinoma (ACC) are largely unexplored. Therefore, we investigated the expression of beclin 1, Bcl-2, and p53 in head and neck ACC tissue. Tissue samples from 35 cases (15 females, 20 males) of head and neck ACC were utilized for immunohistochemistry. Beclin 1 expression was observed in 32 cases (91.4%) and considered to be high in 15 cases (42.9%) and low in 20 cases (57.1%). Beclin 1 expression was significantly correlated with a histological growth pattern (P=0.046) and histological grade (P=0.037). Beclin 1 expression was inversely correlated with Bcl-2 expression (P=0.013) and significantly associated with overall survival (P=0.006). Bcl-2 and p53 expression were observed in 21 cases (60.0%) and 16 cases (45.7%). Bcl-2 expression was significantly correlated with perineural invasion (P=0.041) and not associated with overall survival (P=0.053). p53 expression was directly correlated with beclin 1 expression (P=0.044). Our results indicated that beclin 1 may be a novel, promising prognostic factor for clinical outcome in head and neck ACC patients and may play a part in the development of head and neck ACC by interacting with Bcl-2 and p53.

  19. Expression of beclin 1 in primary salivary adenoid cystic carcinoma and its relation to Bcl-2 and p53 and prognosis

    International Nuclear Information System (INIS)

    Beclin 1 plays a critical role in autophagy and functions as a haploinsufficient tumor suppressor. The expression and prognostic significance of beclin 1 in head and neck adenoid cystic carcinoma (ACC) are largely unexplored. Therefore, we investigated the expression of beclin 1, Bcl-2, and p53 in head and neck ACC tissue. Tissue samples from 35 cases (15 females, 20 males) of head and neck ACC were utilized for immunohistochemistry. Beclin 1 expression was observed in 32 cases (91.4%) and considered to be high in 15 cases (42.9%) and low in 20 cases (57.1%). Beclin 1 expression was significantly correlated with a histological growth pattern (P=0.046) and histological grade (P=0.037). Beclin 1 expression was inversely correlated with Bcl-2 expression (P=0.013) and significantly associated with overall survival (P=0.006). Bcl-2 and p53 expression were observed in 21 cases (60.0%) and 16 cases (45.7%). Bcl-2 expression was significantly correlated with perineural invasion (P=0.041) and not associated with overall survival (P=0.053). p53 expression was directly correlated with beclin 1 expression (P=0.044). Our results indicated that beclin 1 may be a novel, promising prognostic factor for clinical outcome in head and neck ACC patients and may play a part in the development of head and neck ACC by interacting with Bcl-2 and p53

  20. NF-rBp50、p53Bcl-2在宫颈癌组织中的表达及其与人乳头瘤病毒感染的关系%Expressions of NF-κBp50, p53 and Bcl-2 in cervical cancer and their relationship with human papillomavirus infection*

    Institute of Scientific and Technical Information of China (English)

    张婵; 陈向敏; 夏克栋

    2006-01-01

    Objective: To explore the relationship between expressions of NF-κBp50, p53 and Bcl-2 in tissue of cervical cancer and human papillomavirus (HPV) infection. Methods: The expressions of NF-κBp50, p53 and Bcl-2 were detected using immuohistochemical staining in 46 specimens of cervical cancer and 26 specimens of normal cervical tissue. The infection of HPV DNA were determined by PCR. Results: The expressions of NF-κBp50, p53 and Bcl-2 in tissue of cervical cancer were significantly higher than that in normal cervical tissue (P<0.01), and the expressions of NF-κBp50 and p53 or Bcl-2 were closely related (P<0.05). The expression of NF-κBp50 in HPV DNA positive group was significantly higher than that in HPV negative group (P<0.05), but there were no significantly differences in the expressions of p53 and Bcl-2 between HPV DNA positive group and HPV negative group (P>0.05). Conclusion: The expressions of NF-κBp50, p53 and Bcl-2 were significantly correlated with cervical carcinogenesis. NF-κBp50 may be activated by HPV infection.

  1. Cellular functions of p53 and p53 gene family members p63 and p73

    Directory of Open Access Journals (Sweden)

    Nadir Koçak

    2011-12-01

    Full Text Available p53 is a transcription factor that regulates multiple cellular processes that are also important in cellular fates such as cell cycle arrest or programmed cell death. Induction of growth arrest or cell death by p53 prevents the replication of damaged DNA and proliferation of genetically abnormal cells. Therefore, inactivation of p53 by mutation or deletion is also important in ensuring the cellular homeostasis. However, studies showed that p53 deficient mice and cells such as Saos-2 cells are maintaining their life. This situation suggests that p53-related proteins might compensate the functions of p53 in p53 deficient organisms. The identification of two p53-related proteins, p63 and p73 revealed the transcription of p53 responsive genes in p53 deficient organisms. Both p63 and p73 proteins have high homology with the p53 protein and share some of the functions of p53. In contrast to p53, p63 and p73 rarely mutated in human cancers. Here we studied to summarize the current information about the p53 and other p53-related proteins, p63 and p73 that are included into the p53 gene family.

  2. Expression of Inducible Nitric Oxide Synthase, p53 and Bcl-2 in Gastric Precancerous and Cancerous Lesions: Correlation with Clinical Features

    Institute of Scientific and Technical Information of China (English)

    Tao Cui; Zu'an Zhu; Ying Liu; Qingyan Kong; Sujuan Fei

    2006-01-01

    OBJECTIVE To explore the expression of inducible nitric oxide synthase(iNOS), p53 and bcl-2 in gastric precancerous and cancerous lesions and to examine the expression of these proteins in relation to clinical features.METHODS The expressions of iNOS, p53 and bcl-2 proteins in gastric precancerous and cancerous lesions and their correlations with the clinical features were determined using immunohistochemical assays (Power VisionTM two-step method) on 84 gastric carcinomas and 54 gastric atypical hyperplastic tissues. Apoptotic cells were evaluated by terminal deoxynucleotidyl transferase- mediated dUTP-biotin nick-end labeling (TUNEL).RESULTS Expression of iNOS, p53 and bcl-2 was significantly higher in gastric carcinoma (GC) tissues than in gastric atypical hyperplastic tissues. Among the 84 carcinomas, the expression of p53 was observed in 50 (59.52%), bcl-2 in 43 (51.19%), and iNOS in 65 (77.58%). Overexpression of iNOS and bcl-2 in gastrlc carcinoma was related to tumor size and iNOS was related to the presence of lymph node metastasis (P<0.05). The expression of proteins did not correlate with age, sex, stage of disease, or differentiation. Expression of iNOS in gastric carcinoma tissues was positively correlated with bcl-2 expression (χ2=8.926, P=0.003),and also with p53 expression (χ2= 5.2430, P= 0.022). The mean apoptotic indexes (Al) were 1.29%±0.50 in low-grade atypical hyperplasia (LG),0.96%±0.36 in high-grade atypical hyperplasia (HG) and 0.70%±0.43 in GC, with the difference being significant between LG, HG and GC (P<0.05). There was a significant positive correlation between iNOS expression and the Al in GC (t=3.0815, P=0.0028).CONCLUSION iNOS was expressed in the majority of gastric carcinoma tissues and correlated with cellular apoptosis associated with p53 and bcl-2 expression. iNOS overexpression is closely associated with p53 and bcl-2 accumulation status. iNOS may play a synergistic role in the pathogenesis of GC.

  3. The function of apoptosis and protein expression of bcl-2, p53 and C-myc inthe development of gastric cancer

    Institute of Scientific and Technical Information of China (English)

    An Gao Xu; Shao Guang Li; Ji Hong Liu; Ai Hua Gan

    2000-01-01

    AIM To understand the rule and possible function of apoptosis and protein expression of bcl-2, p53 and C-myc in chronic gastritis, gastric ulcer, non-classic proliferation of gastric mucosa and gastric cancer.METHODS Apoptosis was detected by using in situ terminal labelling (TUNEL). The protein expression ofbcl-2, p53 and C-myc was detected by immunohistochemical method.RESULTS The indexes of apoptosis in chronic active gastritis, gastric ulcer, mild and severe non-classicproliferation of gastric mucosa, early and progressive gastric cancer were 16.8%±12.3%, 24.1%±20.0%,19.3%±16.4%, 15.7%±15.2%, 10.1%±9.1% and 6.3%±6.0%, respectively. The index of progressivegastric cancer was lower than that of early gastric cancer and non-classic proliferation of gastric mucosa(P<0.05). The positive rate of bcl-2 protein was 9.4%, 27.6%, 52.9%, 75.0%, 83.3% and 46.7%,respectively. The positive rate of bcl-2 of early gastric cancer was higher than that of progressive gastriccancer. The positive rates of p53 protein of severe non-classic proliferation, early and progressive gastriccancer were 25.0%, 33.3% and 63.3%, respectively. The positive rate of p53 of progressive gastric cancerwas higher than that of early gastric cancer and non-classic proliferation (P<0.05). In Lauren types, theindex of apoptosis, protein expression rates of bcl-2, p53 and C-myc of intestinal type were 8.3%±7.2%,38.9%, 77.7% and 56.6%, while that of diffuse type were 5.1%±4.9%, 58.3%, 50.0% and 8.3%,respectively. All markers had statistical difference between two types (P<0.05).CONCLUSION Apoptosis was inhibited stepwise in the development of non-classic proliferation of gastricmucosa to early gastric cancer and then to progressive gastric cancer. The high expression of bcl-2, p53 andC-myc was related to the development of gastric cancer, bcl-2 might play an important role in early gastriccancer while p53 and C-myc act mostly in middle and late stage gastric cancer. The Lauren typing of

  4. Function of apoptosis and expression of the proteins Bcl-2, p53 and C-myc in the development of gastric cancer

    Institute of Scientific and Technical Information of China (English)

    An Gao Xu; Shao Guang Li; Ji Hong Liu; Ai Hua Gan

    2001-01-01

    @@INTRODUCTION In China ,the incidence and mortality of gastric cancer rank the second among all cancers. Recent development of cancer [1-20].The aim of this study was investigat the insight of apoptosis and bcl-2, p53 and C-myc protein expression in the development of gastric cancer .

  5. Impact of BCL2 and p53 on postmastectomy radiotherapy response in high-risk breast cancer. A subgroup analysis of DBCG82 b&c

    DEFF Research Database (Denmark)

    Kyndi, Marianne; Sørensen, Flemming Brandt; Knudsen, Helle;

    2008-01-01

    PURPOSE: To examine p53 and BCL2 expression in high-risk breast cancer patients randomized to postmastectomy radiotherapy (PMRT). PATIENTS AND METHODS: The present analysis included 1 000 of 3 083 high-risk breast cancer patients randomly assigned to PMRT in the DBCG82 b&c studies. Tissue microar...

  6. Expression of Bcl-2, p53, and MDM2 in Localized Prostate Cancer With Respect to the Outcome of Radical Radiotherapy Dose Escalation

    International Nuclear Information System (INIS)

    Purpose: Established prognostic factors in localized prostate cancer explain only a moderate proportion of variation in outcome. We analyzed tumor expression of apoptotic markers with respect to outcome in men with localized prostate cancer in two randomized controlled trials of radiotherapy dose escalation. Methods and Materials: Between 1995 and 2001, 308 patients with localized prostate cancer received neoadjuvant androgen deprivation and radical radiotherapy at our institution in one of two dose-escalation trials. The biopsy specimens in 201 cases were used to make a biopsy tissue microarray. We evaluated tumor expression of Bcl-2, p53, and MDM2 by immunohistochemistry with respect to outcome. Results: Median follow-up was 7 years, and 5-year freedom from biochemical failure (FFBF) was 70.4% (95% CI, 63.5-76.3%). On univariate analysis, expression of Bcl-2 (p < 0.001) and p53 (p = 0.017), but not MDM2 (p = 0.224), was significantly associated with FFBF. Expression of Bcl-2 remained significantly associated with FFBF (p = 0.001) on multivariate analysis, independently of T stage, Gleason score, initial prostate-specific antigen level, and radiotherapy dose. Seven-year biochemical control was 61% vs. 41% (p = 0.0122) for 74 Gy vs. 64 Gy, respectively, among patients with Bcl-2-positive tumors and 87% vs. 81% (p = 0.423) for 74 Gy vs. 64 Gy, respectively, among patients with Bcl-2-negative tumors. There was no statistically significant interaction between dose and Bcl-2 expression. Conclusions: Bcl-2 expression was a significant, independent determinant of biochemical control after neoadjuvant androgen deprivation and radical radiotherapy for prostate cancer. These data generate the hypothesis that Bcl-2 expression could be used to inform the choice of radiotherapy dose in individual patients.

  7. Study on Apoptosis and Expression of P53, Bcl-2, Bax in Cardiac Myocytys of Congestive Heart Failure Induced by Ventricular Pacing

    Institute of Scientific and Technical Information of China (English)

    QI; Benling; CAO; Linsheng; WANG; Lin; ZHOU; Jingqun

    2001-01-01

    The apoptosis and the expression of p53, bcl-2 and Bax in myocytes of chronic rapid ventricular pacing-induced congestive heart failure (CHF) in rabbits were investigated. The CHF rabbit model (P, n= 7) was established by chronic rapid ventricular pacing for 3 weeks. By using TUNEL technique the apoptosis in the myocytes in the rabbit model was studied and the expression of p53,bcl-2 and Bax in myocytes was detected by using immunohistochemical method. Sham-operated (C,n = 9) group served as control group. The results showed that there were about 4033± 884.56 apoptotic cells/106 myocytes in P group, but no apoptotic cells were found in C group. Myocytes positive for p53 immunoreactivity (18. 86±8. 48 vs 5. 06±0. 87, P<0.01) and positive for Bax immunoreactivity (7. 15±1.91 vs 0. 43±0. 09, P<0.01) were increased in P group as compared with those in C group, while the myocytes positive for bcl-2 immunoreactivity (7. 08±1.05 vs 14. 97±4.47,P<0. 01) and the ratio of bcl-2/Bax were decreased in P group as compared with those in C group.Apoptosis was involved in the development of CHF induced by continuously rapid ventricular pacing in rabbit. The expression of p53 and Bax was increased, while the expression of bcl-2 was inhibited.These might play an important role in the acceleration of the apoptosis.

  8. 角果木提取物tagalsin对H22细胞原位移植肝癌p53Bcl-2表达的影响%Effect of tagalsin on p53 and Bcl-2 expression in hepatoma H22 tumor-bearing mice

    Institute of Scientific and Technical Information of China (English)

    宋修岐; 郭云良; 王炳高; 孙少杰; 姚如永

    2011-01-01

    Objective To explore the effect and mechanism of tagalsin on hepatoma cells. Methods The animal models were established by transplanting H22 mouse hepatoma cells to mouse liver, and ten days later the mice were randomly divided into five groups: blank group, carmofur positive group and tagalsin groups, including low-dose, middle-dose and high-dose groups. Then medicine or oil was given to the mice by gastric gavage in consecutive 5 days with a 2-days interval as a course of treatment, two courses in all. All mice were killed at 24 hours after medication, and the survival period, ascites conditions, aggressive conditions intra- or extra- liver, weight changes, tumor volume and spleen index of the tumor-bearing mice were observed. Pathological changes of the tumors were examined. Apoptotic factors p53 and Bcl-2 protien and mRNA were detected by immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR). Results tagalsin inhibited the hepatoma growth effectively without influencing spleen index to some extent. The tumor inhibition rate of tagalsin low, middle and high dose groups were 17.9%, 63.1% and 71.8%, respectively. Immunohistochemical results showed that the p53 and Bcl-2 protein positive cell counts of the positive control and experimental groups were significantly lower than those of the blank group (P<0.01). RT-PCR results showed that the p53 mRNA expression was significantly enhanced and Bcl-2 mRNA expression was decreased in the positive control groups and tagalsin treatment groups, especially in the high dose group, compared with those of the blank group (P<0.05). Conclusions tagalsin can inhibit the growth of mouse hepatoma cells significantly. The mechanism of its anti-tumor effect may work via up-regulating the wild type p53 gene expression and down-regulating Bcl-2 gene expression and thus regulating tumor cell apoptosis.%目的 探讨角果木提取物tagalsin对小鼠原位移植肝癌的干预作用.方法 建立小鼠原位

  9. Correlation of p53 gene mutation and expression of P53 protein in cholangiocarcinoma

    Institute of Scientific and Technical Information of China (English)

    Xiao-Fang Liu; Hao Zhang; Shi-Guang Zhu; Xian-Ting Zhou; Hai-Long Su; Zheng Xu; Shao-Jun Li

    2006-01-01

    AIM: To characterize the tumor suppressor gene p53 mutations and study the correlation of p53 gene mutation and the expression of P53 protein in cholangiocarcinoma.METHODS: A total of 36 unselected, frozen samples of cholangiocarcinoma were collected. p53 gene status(exon 5-8) and P53 protein were examined by automated sequencing and immunohistochemical staining, combined with the clinical parameters of patients.RESULTS: p53 gene mutations were found in 22 of 36 (61.1%) patients. Nineteen of 36 (52.8%) patients were positive for P53 protein expression. There were significant differences in extent of differentiation and invasion between the positive and negative expression of P53 protein. However, there were no significant differences in pathologic parameters between the mutations and non-mutations.CONCLUSION: The alterations of the p53 gene evaluated by DNA sequence analysis is relatively accurate. Expression of P53 protein could not act as an independent index to estimate the prognosis of cholangiocarcinoma.

  10. The Relationship of Expression of bcl-2, p53, and Proliferating Cell Nuclear Antigen (PCNA) to Cell Proliferation and Apoptosis in Renal Cell Carcinoma

    Institute of Scientific and Technical Information of China (English)

    朱朝辉; 邢诗安; 程平; 李国胜; 杨郁; 曾甫清; 鲁功成

    2004-01-01

    To investigate the relationship of bcl-2, p53, proliferating cell nuclear antigen (PCNA) to cell proliferation, apoptosis and pathological parameters, the patterns of cell growth and turnover in renal cell carcinoma (RCC), formalin-fixed and paraffin-embedded tissue blocks from 34 patients with RCC were examined. Cell proliferation activity was detected by PCNA immunostaining and the proliferation index (PI) was expressed as a percentage of the PCNA-positive cells in the tumor cells. Apoptosis was detected by terminal deoxy- nucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL), and the apoptotic index (AI) was expressed as a percentage of the TUNEL-positive cells in the tumor cells. Expressions of bcl-2 and p53 were assessed immunohistochemically. Our results showed that the PI ranged from 6.0 % to 24.0 % (median 12.3 %) and theAI from 2.0 % to 8.0 % (median 5.4 %) in RCC. The expression of the bcl-2 protein was demonstrated in 15 cases (44.1 %); the expression of the p53 protein, however, was seen in only 3 case. bcl-2 positivity was not associated with PI or AI or any pathological parameters. There were close associations between PI and tumor grade and stage, and a significant relationship between AI and the tumor grade of RCC. Our study suggests that bcl-2 positivity was not associated with PI or AI or any pathological parameters. There are close associations between PI and AI and tumor grade and stage of RCC. Active cell proliferation may be accompanied by frequent apoptosis in RCC.

  11. P53蛋白和Bcl-2蛋白在环孢菌素和硝苯地平龈增生中的表达%Expression of P53 Protein and Bcl-2 Protein in Gingival Hyperplasia Induced by Cyclosporine and Nifedipine

    Institute of Scientific and Technical Information of China (English)

    王美娟; 孙卫斌; 刘卫红; 朱庆萍

    2004-01-01

    目的探讨凋亡相关蛋白P53Bcl-2在药物性龈增生中的表达及意义.方法用免疫组化SP法检测17例环孢菌素性龈增生、5例硝苯地平性龈增生牙龈中P53Bcl-2蛋白的表达,8例正常人牙龈作对照.结果17例环孢菌素性龈增生中有11例、5例硝苯地平性龈增生中有3例的牙龈上皮中有P53蛋白的阳性表达,而对照组均无P53蛋白的表达.Bcl-2蛋白在环孢菌素及硝苯地平性龈增生的牙龈上皮中,表达比较明显,而在对照组的牙龈上皮中,染色明显偏淡.结论本研究结果中P53Bcl-2蛋白表达增强,提示细胞凋亡抑制可能在药物性龈增生的发病中起作用.

  12. Bax, Bcl2, and p53 differentially regulate neomycin- and gentamicin-induced hair cell death in the zebrafish lateral line.

    Science.gov (United States)

    Coffin, Allison B; Rubel, Edwin W; Raible, David W

    2013-10-01

    Sensorineural hearing loss is a normal consequence of aging and results from a variety of extrinsic challenges such as excessive noise exposure and certain therapeutic drugs, including the aminoglycoside antibiotics. The proximal cause of hearing loss is often death of inner ear hair cells. The signaling pathways necessary for hair cell death are not fully understood and may be specific for each type of insult. In the lateral line, the closely related aminoglycoside antibiotics neomycin and gentamicin appear to kill hair cells by activating a partially overlapping suite of cell death pathways. The lateral line is a system of hair cell-containing sense organs found on the head and body of aquatic vertebrates. In the present study, we use a combination of pharmacologic and genetic manipulations to assess the contributions of p53, Bax, and Bcl2 in the death of zebrafish lateral line hair cells. Bax inhibition significantly protects hair cells from neomycin but not from gentamicin toxicity. Conversely, transgenic overexpression of Bcl2 attenuates hair cell death due to gentamicin but not neomycin, suggesting a complex interplay of pro-death and pro-survival proteins in drug-treated hair cells. p53 inhibition protects hair cells from damage due to either aminoglycoside, with more robust protection seen against gentamicin. Further experiments evaluating p53 suggest that inhibition of mitochondrial-specific p53 activity confers significant hair cell protection from either aminoglycoside. These results suggest a role for mitochondrial p53 activity in promoting hair cell death due to aminoglycosides, likely upstream of Bax and Bcl2.

  13. Study on expression of p53bcl-2、 bax and PCNA in retinoblastoma%视网膜母细胞瘤p53bcl-2、bax及增殖细胞核抗原的表达意义

    Institute of Scientific and Technical Information of China (English)

    李琳; 雷霍; 杨慧

    2002-01-01

    目的了解视网膜母细胞瘤(retinoblastoma,Rb)p53bcl-2、bax和增殖细胞核抗原表达与Rb及其分化程度的关系.方法用免疫组化检测21例Rb和6例正常视网膜常规石蜡标本进行p53bcl-2、bax和PCNA表达.结果bc1-2、bax和PCNA在Rb中的表达较高,与正常视网膜相比有显著性差异,分化性Rb组织bcl-2阳性表达率较高,与未分化型Rb组织相比有显著性差异.p53bcl-2、bax在Rb中的表达与PCNA的表达有显著相关性.结论 Rb的发生与多个细胞凋亡调控基因异常有关,测定和分析Rb的bcl-2、PCNA、bax和表达,对于Rb的诊断和分化程度有重要意义.

  14. Genetic dissimilarity between primary colorectal carcinomas and their lymph node metastases: ploidy, p53, bcl-2, and c-myc expression--a pilot study.

    Science.gov (United States)

    Zalata, Khaled Refaat; Elshal, Mohamed Farouk; Foda, Abd AlRahman Mohammad; Shoma, Ashraf

    2015-08-01

    The current paradigm of metastasis proposes that rare cells within primary tumors acquire metastatic capability via sequential mutations, suggesting that metastases are genetically dissimilar from their primary tumors. This study investigated the changes in the level of expression of a well-defined panel of cell proliferation, differentiation, and apoptosis markers between the primary colorectal cancer (CRC) and the corresponding synchronous lymph node (LN) metastasis from the same patients. DNA flow cytometry and immunostaining of p53, bcl-2, and c-myc were carried out on 36 cases of CRC radical resection specimens with their corresponding LN metastases. There was very low probability that the histological patterns of primary tumors and LN metastases are independent (p < 0.001). Metastatic tumors were significantly more diffusely positive for p53 than the primary tumors (p < 0.001). Conversely, primary tumors were significantly more diffusely positive for c-myc than metastatic tumors (p = 0.011). No significant difference was found between the LNs and the primary tumors in bcl-2 positivity (p = 0.538) and DNA aneuploidy (p = 0.35), with a tendency towards negative bcl-2 and less aneuploidy in LN metastases than primary tumors. In conclusion, LN metastatic colorectal carcinomas have a tendency of being less differentiated, with a higher incidence of diffuse p53 staining, lower incidence of bcl-2 staining, and less aneuploidy in comparison to their primary counterparts suggesting a more aggressive biological behavior, which could indicate the necessity for more aggressive adjuvant therapy. PMID:25840688

  15. Clinicophatological features of non-hodgkin's lymphoma in children and the relationship of LMP-1 and P53bcl-2 protein expression%儿童非霍奇金淋巴瘤EB病毒LMP-1和P53bcl-2表达的关系

    Institute of Scientific and Technical Information of China (English)

    黄波; 郭瑞珍; 明晓务; 王俊; 李青; 唐文台; 肖庆帮

    2003-01-01

    目的探讨儿童NHL EB病毒LMP-1和P53bcl-2蛋白的表达及关系.方法采用免疫组化Envision法检测64例儿童NHL中LMP-1和P53bcl-2蛋白.结果 (1)P53蛋白阳性表达39例(60.9%),表达强度与淋巴瘤恶性程度呈正相关;阳性表达率在低恶组与中、高恶性组间有显著性意义,P<0.01.bcl-2蛋白阳性表达37例(53.8%),bcl高于TCL,低恶性高于高恶性.(2)LMP-1蛋白阳性表达45例(70.3%),阳性表达率与肿瘤恶性程度和年龄有统计学意义,P<0.01;而与淋巴瘤免疫表型、性别和发病部位无关.LMP-1表达与P53bcl-2的表达呈正相关.结论 EBV感染是儿童NHL发生发展不可忽视的病毒致病因素,其致病作用可能是通过上调P53bcl-2蛋白实现的.

  16. Shifting p53-induced senescence to cell death by TIS21(/BTG2/Pc3) gene through posttranslational modification of p53 protein.

    Science.gov (United States)

    Choi, Ok Ran; Ryu, Min Sook; Lim, In Kyoung

    2016-09-01

    Cellular senescence and apoptosis can be regulated by p53 activity, although the underlying mechanism of the switch between the two events remains largely unknown. Cells exposed to cancer chemotherapy can escape to senescence phenotype rather than undergoing apoptosis. By employing adenoviral transduction of p53 or TIS21 genes, we observed shifting of p53 induced-senescence to apoptosis in EJ bladder cancer cells, which express H-RasV12 and mutant p53; transduction of p53 increased H-RasV12 expression along with senescence phenotypes, whereas coexpression with TIS21 (p53+TIS21) induced cell death rather than senescence. The TIS21-mediated switch of senescence to apoptosis was accompanied by nuclear translocation of p53 protein and its modifications on Ser-15 and Ser-46 phosphorylation and acetylations on Lys-120, -320, -373 and -382 residues. Mechanistically, TIS21(/BTG2) regulated posttranslational modification of p53 via enhancing miR34a and Bax expressions as opposed to inhibiting SIRT1 and Bcl2 expression. At the same time, TIS21 increased APAF-1 and p53AIP1 expressions, but inhibited the interaction of p53 with iASPP. In vitro tumorigenicity was significantly reduced in the p53+TIS21 expresser through inhibiting micro-colony proliferation by TIS21. Effect of TIS21 on the regulation of p53 activity was confirmed by knockdown of TIS21 expression by RNA interference. Therefore, we suggest TIS21 expression as an endogenous cell death inducer at the downstream of p53 gene, which might be useful for intractable cancer chemotherapy. PMID:27208501

  17. Bcl-2 gene therapy for apoptosis following traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    YANG Xiao-feng; ZHENG Xue-sheng; LIU Wei-guo; FENG Jun-feng

    2006-01-01

    Objective: To investigate the therapeutic effect of Bcl- 2 fusion protein on apoptosis in brain following traumatic brain injury.Methods: Bcl-2 gene was cloned by RT-PCR. Bcl-2 and EGFP genes were linked together and inserted into pAdeno-X vector. This recombinant vector was packaged into infectious adenovirus in HEK293 cells. Ninety Wistar rats were assigned randomly into experimental group(n=45) and control group (n=45). All rats were subjected to traumatic brain injury. Then recombinant adenovirus (for experimental group) or saline (for control group) was injected into the traumatic brain. The expression of Bcl-2 fusion protein was investigated by Western blotting, immunohistochemistry and fluorescence microscopy. Apoptosis in the injured brain was studied by TUNEL. Animals' behavior capacity was evaluated by tiltboard test.Results: In the experimental group, many fluorescent cells were found around the traumatic locus,which were also proven to be Bcl-2-positive by immunohistochemistry. On the contrary, few Bcl-2-positive cells and no fluorescent cell were detected in the control group. Bcl-2 expression of experimental group was much higher than that of control group, which was illustrated by Western blotting. The apoptosis index of experimental group was 0.027 ± 0.005, and that of control group was 0.141±0.025 (P<0.01). Two weeks after injury, animals of the experimental group behaved better than those of the control group.Conclusions: A recombinant adenovirus vector expressing Bcl-2 fusion protein has been constructed. Bcl-2 fusion protein can suppress apoptosis and promote cell survival. Moreover, the behavior recovery of the injured animal is promoted. Bcl-2 fusion protein provides a way to track the target cells in vivo.

  18. Comparison of Nuclear Accumulation of p53 Protein with Mutations in the p53 Gene of Human Breast Cancer Tissues

    Institute of Scientific and Technical Information of China (English)

    王萱仪; 查小明; 武正炎; 范萍

    2001-01-01

    Objective The objective was to compare nuclear accumulation of p53 protein with mutations in the p53 gene on the tissues of human breast cancer. Methods Fifty-four invasive ductal carcinomas of breast were analyzed by the method of polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) silver stain and strep-avidin-biotin-peroxidase complex (SABC) immunohistochemistry. Results A statistically significant association between the presence of p53 gene mutation and nuclear accumulation of p53 protein was found (P<0.01). 22 tumors that demonstrated p53 gene mutations showed nuclear accumulation of p53 protein, while only 9 (28%) showed nuclear accumulation of p53 protein in 32 tumors without p53 gene mutations. Both p53 mutation protein and p53 gene mutations were prevalent in steroid and progesterone receptors negative tumors (P<0.05). A statistically significant association was found between the nuclear accumulation of p53 protein and lymph node invasion (P<0.05), and between p53 gene mutations and lymph node invasion (P<0.05). p53 abnormalities might be associated with an aggressive phenotype in breast cancer. Conclusion The immunohistochemical detection of nuclear p53 protein accumulation is highly associated with p53 gene mutations in breast cancer tissues, and that this method is useful for rapid screening of p53 abnormalities. However, in order to avoid false positive reaction, the p53 gene mutations should be determined in cases slightly positive for p53 nuclear protein.

  19. 尼莫地平对帕金森病模型鼠黑质多巴胺能神经元中Bcl-2P53蛋白表达的影响%Effect of Nimodipine on the expression of Bcl-2 and P53 protein in dopaminergic neurons of rats with Parkinson's disease

    Institute of Scientific and Technical Information of China (English)

    费娜; 许丽珍

    2007-01-01

    目的 观察尼莫地平对帕金森病模型鼠多巴胺能神经元中Bcl-2P53蛋白表达的影响,从而探索尼莫地平对黑质多巴胺能神经元的保护作用.方法 建立大鼠PD模型,分组、分阶段用尼莫地平进行干预,第一阶段为尼莫地平对PD模型的预先干预,第二阶段为成功PD模型的药物治疗(尼莫地平、左旋多巴),其后均由阿朴吗啡(Apomorphine)诱导旋转行为,最后予大鼠黑质细胞进行HE、TH、Bcl-2P53染色.结果 第一阶段:尼莫地平PD模型组(Ⅰ组)和PD模型组(Ⅱ组),成功模型右侧黑质Bcl-2蛋白表达阳性细胞百分比较假手术组(Ⅲ组)和正常对照组(Ⅳ组)低(P<0.05),而P53蛋白表达阳性细胞百分比较Ⅲ组和Ⅳ组高(P<0.05);Ⅰ组右侧黑质Bcl-2蛋白表达阳性细胞百分比高于Ⅱ组(P<0.05),而P53蛋白表达阳性细胞百分比低于Ⅱ组(P<0.05);第二阶段:尼莫地平组、左旋多巴组或二者联用干预组与生理盐水组间右侧黑质Bcl-2P53蛋白表达阳性细胞百分比无统计学差异(P>0.05).结论 尼莫地平在蛋白合成水平促进了Bcl-2表达、抑制了P53表达,减缓了多巴胺能神经元的凋亡.

  20. Identification of p53-target genes in Danio rerio

    Science.gov (United States)

    Mandriani, Barbara; Castellana, Stefano; Rinaldi, Carmela; Manzoni, Marta; Venuto, Santina; Rodriguez-Aznar, Eva; Galceran, Juan; Nieto, M. Angela; Borsani, Giuseppe; Monti, Eugenio; Mazza, Tommaso; Merla, Giuseppe; Micale, Lucia

    2016-01-01

    To orchestrate the genomic response to cellular stress signals, p53 recognizes and binds to DNA containing specific and well-characterized p53-responsive elements (REs). Differences in RE sequences can strongly affect the p53 transactivation capacity and occur even between closely related species. Therefore, the identification and characterization of a species-specific p53 Binding sistes (BS) consensus sequence and of the associated target genes may help to provide new insights into the evolution of the p53 regulatory networks across different species. Although p53 functions were studied in a wide range of species, little is known about the p53-mediated transcriptional signature in Danio rerio. Here, we designed and biochemically validated a computational approach to identify novel p53 target genes in Danio rerio genome. Screening all the Danio rerio genome by pattern-matching-based analysis, we found p53 RE-like patterns proximal to 979 annotated Danio rerio genes. Prioritization analysis identified a subset of 134 candidate pattern-related genes, 31 of which have been investigated in further biochemical assays. Our study identified runx1, axin1, traf4a, hspa8, col4a5, necab2, and dnajc9 genes as novel direct p53 targets and 12 additional p53-controlled genes in Danio rerio genome. The proposed combinatorial approach resulted to be highly sensitive and robust for identifying new p53 target genes also in additional animal species. PMID:27581768

  1. Identification of p53-target genes in Danio rerio.

    Science.gov (United States)

    Mandriani, Barbara; Castellana, Stefano; Rinaldi, Carmela; Manzoni, Marta; Venuto, Santina; Rodriguez-Aznar, Eva; Galceran, Juan; Nieto, M Angela; Borsani, Giuseppe; Monti, Eugenio; Mazza, Tommaso; Merla, Giuseppe; Micale, Lucia

    2016-01-01

    To orchestrate the genomic response to cellular stress signals, p53 recognizes and binds to DNA containing specific and well-characterized p53-responsive elements (REs). Differences in RE sequences can strongly affect the p53 transactivation capacity and occur even between closely related species. Therefore, the identification and characterization of a species-specific p53 Binding sistes (BS) consensus sequence and of the associated target genes may help to provide new insights into the evolution of the p53 regulatory networks across different species. Although p53 functions were studied in a wide range of species, little is known about the p53-mediated transcriptional signature in Danio rerio. Here, we designed and biochemically validated a computational approach to identify novel p53 target genes in Danio rerio genome. Screening all the Danio rerio genome by pattern-matching-based analysis, we found p53 RE-like patterns proximal to 979 annotated Danio rerio genes. Prioritization analysis identified a subset of 134 candidate pattern-related genes, 31 of which have been investigated in further biochemical assays. Our study identified runx1, axin1, traf4a, hspa8, col4a5, necab2, and dnajc9 genes as novel direct p53 targets and 12 additional p53-controlled genes in Danio rerio genome. The proposed combinatorial approach resulted to be highly sensitive and robust for identifying new p53 target genes also in additional animal species. PMID:27581768

  2. Targeting p53 and its domains for cancer gene therapy

    OpenAIRE

    Karina Julia Matissek

    2014-01-01

    The tumor suppressor p53 is one of the most frequently mutated proteins in human cancer and has been extensively targeted for cancer therapy. This resulted in wild type p53 gene therapeutic approval for the treatment of head and neck cancer in China. p53 mainly functions as a transcription factor and stimulates a variety of genes involved in the intrinsic and extrinsic apoptotic pathway by binding to p53 responsive elements as a t...

  3. Impact of Curcuma mangga Val. Rhizome Essential Oil to p53, Bcl-2, H-Ras and Caspase-9 expression of Myeloma Cell Line

    Directory of Open Access Journals (Sweden)

    Endang Astuti

    2015-12-01

    Full Text Available Cancer is a disease, a public health problem, which is found in the world as well as in Indonesia. Ingeneral, some of cancer theraphies are ineffective, characterized by the resistance performance of cancer cell line,the exposed normal cell and by the side effects. Nowadays, studies to fi nd the specifi c and safely anti-cancerdrugs were increased by the time. Several studies revealed that Curcuma mangga Val. Rhizome contains somesecondary metabolites, essential or non-essential oil, which has cytotoxic activities to the cancer cells. Basedon these anti-cancer potentials, this study has several aims to recognize anti-cancer selectivity and molecularmechanism by inducting apoptosis and inhibiting myeloma cell proliferation. To C. mangga Val. essential oil,immunocyto chemical test was performed to determine the expression of p53, caspase-9, Bcl-2, H-Ras proteinwhile TUNEL test was performed to determine the number of apoptosis cells.The results of this study shown that anti-cancer molecular mechanism of C. mangga Val. essential oil tomyeloma cell line was performed by increasing apoptosis; by increasing the expression of pro-apoptosis p53,caspase-9 protein and reducing protein which is increasing proliferation Bcl-2 and H-Ras.

  4. p53 isoform Δ113p53 is a p53 target gene that antagonizes p53 apoptotic activity via BclxL activation in zebrafish

    OpenAIRE

    Chen, Jun; Ng, Sok Meng; Chang, Changqing; Zhang, Zhenhai; Bourdon, Jean-Christophe; Lane, David P.; Peng, Jinrong

    2009-01-01

    p53 is a well-known tumor suppressor and is also involved in processes of organismal aging and developmental control. A recent exciting development in the p53 field is the discovery of various p53 isoforms. One p53 isoform is human Δ133p53 and its zebrafish counterpart Δ113p53. These N-terminal-truncated p53 isoforms are initiated from an alternative p53 promoter, but their expression regulation and physiological significance at the organismal level are not well understood. We show here that ...

  5. Cancer-derived p53 mutants suppress p53-target gene expression—potential mechanism for gain of function of mutant p53

    OpenAIRE

    Vikhanskaya, Faina; Lee, Ming Kei; Mazzoletti, Marco; Broggini, Massimo; Sabapathy, Kanaga

    2007-01-01

    Tumour-derived p53 mutants are thought to have acquired ‘gain-of-function’ properties that contribute to oncogenicity. We have tested the hypothesis that p53 mutants suppress p53-target gene expression, leading to enhanced cellular growth. Silencing of mutant p53 expression in several human cell lines was found to lead to the upregulation of wild-type p53-target genes such as p21, gadd45, PERP and PTEN. The expression of these genes was also suppressed in H1299-based isogenic cell lines expre...

  6. The influence of sleep deprivation on expression of apoptosis regulatory proteins p53, bcl-2 and bax following rat tongue carcinogenesis induced by 4-nitroquinoline 1-oxide

    Directory of Open Access Journals (Sweden)

    Juliana Noguti

    2013-01-01

    Full Text Available Background: The aim of this study was to evaluate whether paradoxical sleep deprivation could affects the mechanisms and pathways essentials for cancer cells in tongue cancer induced by 4-nitroquinole 1-oxide in Wistar rats. Materials and Methods: For this purpose, the animals were distributed into 4 groups of 5 animals each treated with 50 ppm 4 nitroquinoline 1 oxide (4 NQO solution through their drinking water for 4 and 12 weeks. The animals were submitted to paradoxical sleep deprivation (PSD for 72 h using the modified multiple platform method, which consisted of placing 5 mice in a cage (41 × 34 × 16 cm containing 10 circular platforms (3.5 cm in diameter with water 1 cm below the upper surface. The investigations were conducted using immunohistochemistry of p53, Bax and Bcl-2 proteins related to apoptosis and its pathways. Statistical analysis was performed by Kruskal-Wallis non-parametric test followed by the Dunn′s test using SPSS software pack (version 1.0. P value < 0.05 was considered for statistic significance. Results: Although no histopathological abnormalities were induced in the epithelium after 4 weeks of carcinogen exposure in all groups, in 12 weeks were observed pre-neoplasic lesions. Data analysis revealed statistically significant differences ( P < 0.05 in 4 weeks group for p53 and for bcl-2 and for all immunomarkers after 12 weeks of 4NQO administration. Conclusion: Our results reveal that sleep deprivation exerted alterations in proteins associated with proliferation and apoptosis in carcinogenesis.

  7. Effects of p53 mutants derived from lung carcinomas on the p53-responsive element (p53RE) of the MDM2 gene

    OpenAIRE

    Gorgoulis, V. G.; Zacharatos, P. V.; Manolis, E.; Ikonomopoulos, J. A.; Damalas, A.; Lamprinopoulos, C.; Rassidakis, G Z; Zoumpourlis, Vassilis; Kotsinas, A.; Rassidakis, A. N.; Halazonetis, T. D.; KITTAS, C.

    2008-01-01

    The present study represents a continuation of previous works in which we observed that lung carcinomas co-expressing MDM2 protein and p53 mutants (mt p53) exhibited more aggressive behaviour. In the above studies, we suggested a 'gain of function' mechanism of mt p53 proteins based on the fact that the MDM2 gene possesses a p53-responsive element (MDM2-p53RE). In this study, to prove our hypothesis, we selected 12 cases from a series of 51 bronchogenic carcinomas. In these 12 cases, we exami...

  8. 凋亡抑制基因bcl-2p53及ki-67在膀胱良恶性病变中的表达

    Institute of Scientific and Technical Information of China (English)

    桂律; 林梅绥; 李如昌; 许祖德; 罗金芳

    2000-01-01

    目的探讨凋亡抑制基因bcl-2p53及ki-67在膀胱移行细胞癌(TCC)和腺性膀胱炎(CC)中的表达,及其与TCC分化和浸润程度的关系.方法采用免疫组化Dako Envision System方法,测定bcl-2p53、ki-67在72例TCC和47例CC中的表达情况.结果Bc1-2、p53和ki-67在TCC中表达的阳性率分别为31.9%、65.3%和51.4%,在CC中表达的阳性率分别为89.4%、14.9%和10.6%;低分化TCC易于高表达p53和ki-67,ki-67高表达还与TCC浸润性显著相关.结论TCC的发生发展与bcl-2p53基因调节失控有关bcl-2表达可能是TCC肿瘤发生过程中的早期事件,p53和ki-67高表达是TCC分化程度低及浸润性强的标志.

  9. Prognostic Value of Immunohistochemical Staining of p53, bcl-2, and Ki-67 in Small Cell Lung Cancer

    OpenAIRE

    Paik, Kwang Hyun; Park, Yeon Hee; Ryoo, Baek-Yeol; Yang, Sung Hyun; Lee, Jae Cheol; Kim, Cheol Hyun; Ki, Seung Seog; Kim, Jung Min; Park, Myung Joon; Ahn, Heui June; Choi, Won; Chung, Jin Haeng

    2006-01-01

    Small cell lung cancer (SCLC) is one of the most fatal cancers in humans and many factors are known to be related to its poor prognosis. Immunohistochemical (IHC) stainings were done on SCLC specimens in order to investigate the prognostic value of the apoptosis-related gene expression and the tumor proliferative maker, and the relationships among these IHC results and patients clinical characteristics, chemoresponsiveness, and survival were analyzed. The medical records of 107 patients were ...

  10. Suicide genes or p53 gene and p53 target genes as targets for cancer gene therapy by ionizing radiation

    International Nuclear Information System (INIS)

    Radiotherapy has some disadvantages due to the severe side-effect on the normal tissues at a curative dose of ionizing radiation (IR). Similarly, as a new developing approach, gene therapy also has some disadvantages, such as lack of specificity for tumors, limited expression of therapeutic gene, potential biological risk. To certain extent, above problems would be solved by the suicide genes or p53 gene and its target genes therapies targeted by ionizing radiation. This strategy not only makes up the disadvantage from radiotherapy or gene therapy alone, but also promotes success rate on the base of lower dose. By present, there have been several vectors measuring up to be reaching clinical trials. This review focused on the development of the cancer gene therapy through suicide genes or p53 and its target genes mediated by IR. (authors)

  11. P53,Bax,Bcl-2蛋白表达及细胞凋亡在急性放射性皮肤溃疡发生发展过程中的作用探讨%The role of P53, Bax, Bcl-2 expression and cell apoptosis in the formation and development of acute radiation-induced skin ulcers

    Institute of Scientific and Technical Information of China (English)

    谷庆阳; 曹卫红; 王德文; 高亚兵; 杨志祥; 赵坡

    2001-01-01

    目的:研究细胞凋亡及一些凋亡相关基因(p53,bcl-2,bax)的表达在急性放射性皮肤溃疡发生发展过程中的作用.方法:采用Wistar大鼠以60Co γ射线进行局部照射,建立急性放射性皮肤溃疡动物模型,观察病变40 d,然后采用免疫组化方法检测皮肤溃疡组织中P53,Bcl-2,Bax蛋白表达,并采用原位末端标记法(TUNEL)检测细胞凋亡.结果:照后14 d照射野内开始出现皮肤溃疡,之后逐渐扩大、融合、加深;照后11~40 d,P53蛋白表达明显增强,主要定位于血管内皮细胞和小血管平滑肌中;照后14~21 d为Bax蛋白表达高峰,之后逐渐减弱,主要定位于血管内皮细胞、部分成纤维细胞及新生表皮细胞中;Bcl-2则在照后1~11 d呈弱或中度阳性,定位于表皮、毛囊上皮及血管内皮中,之后为阴性或可疑阳性;照后11~35 d,上述细胞特别是血管内皮细胞凋亡率较正常伤口愈合早期增高.结论:辐射诱导的P53,Bax,Bcl-2表达的变化及细胞凋亡率特别是血管内皮细胞凋亡率的增高与放射性皮肤溃疡发生、发展及难愈合(不能形成有效肉芽组织)的分子机制相关.%Objective:To study the expression of P53, Bax, Bcl-2 proteins and the role of cell apoptosis in the formation and development of acute radiation-induced skin ulcers.Methods:A rat model which was locally irradiated with 60 Co γ-rays was used, and the pathological changes were observed for 40 days. Immunohistochemistry and TUNEL assay were performed which enabled the detection of P53, Bax, Bcl-2 and cell apoptosis during the formation and development of radiation skin ulcers.Results: Skin ulcers were found on day 14 after irradiation, and enlarged and deepened gradually during the observation period. P53 was over expressed during days 11 to 40 after irradiation and was localized in vascular endotheliocytes and smooth muscle cells. Bax was moderately positive during days 14 to 21 and weakly positive during days

  12. Immunohistochemical Determination of p53 Protein Overexpression for Predicting p53 Gene Mutations in Hepatocellular Carcinoma: A Meta-Analysis

    Science.gov (United States)

    Deng, Miao; Liu, Dechun; Ma, Qingyong; Feng, Xiaoshan

    2016-01-01

    Background Whether increased expression of the tumor suppressor protein p53 indicates a p53 gene mutation in hepatocellular carcinoma (HCC) remains unclear. We conducted a meta-analysis to determine whether p53 protein overexpression detected by immunohistochemistry (IHC) offers a diagnostic prediction for p53 gene mutations in HCC patients. Methods Systematic literature searches were conducted with an end date of December 2015. A meta-analysis was performed to estimate the diagnostic accuracy of IHC-determined p53 protein overexpression in the prediction of p53 gene mutations in HCC. Sensitivity, subgroup, and publication bias analyses were also conducted. Results Thirty-six studies were included in the meta-analysis. The results showed that the overall sensitivity and specificity for IHC-determined p53 overexpression in the diagnostic prediction of p53 mutations in HCC were 0.83 (95% CI: 0.80–0.86) and 0.74 (95% CI: 0.71–0.76), respectively. The summary positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were 2.65 (95% CI: 2.21–3.18) and 0.36 (95% CI: 0.26–0.50), respectively. The diagnostic odds ratio (DOR) of IHC-determined p53 overexpression in predicting p53 mutations ranged from 0.56 to 105.00 (pooled, 9.77; 95% CI: 6.35–15.02), with significant heterogeneity between the included studies (I2 = 40.7%, P = 0.0067). Moreover, subgroup and sensitivity analyses did not alter the results of the meta-analysis. However, potential publication bias was present in the current meta-analysis. Conclusion The upregulation of the tumor suppressor protein p53 was indeed linked to p53 gene mutations. IHC determination of p53 overexpression can predict p53 gene mutations in HCC patients. PMID:27428001

  13. Cellular functions of p53 and p53 gene family members p63 and p73

    OpenAIRE

    Nadir Koçak; İbrahim Halil Yıldırım; Seval Cing Yıldırım

    2011-01-01

    p53 is a transcription factor that regulates multiple cellular processes that are also important in cellular fates such as cell cycle arrest or programmed cell death. Induction of growth arrest or cell death by p53 prevents the replication of damaged DNA and proliferation of genetically abnormal cells. Therefore, inactivation of p53 by mutation or deletion is also important in ensuring the cellular homeostasis. However, studies showed that p53 deficient mice and cells such as Saos-2 cells are...

  14. KSP inhibitor SB743921 inhibits growth and induces apoptosis of breast cancer cells by regulating p53, Bcl-2, and DTL.

    Science.gov (United States)

    Zhu, Li; Xiao, Fengjun; Yu, Yue; Wang, Hua; Fang, Min; Yang, Yuefeng; Sun, Huiyan; Wang, Lisheng; Sheng, Yuan

    2016-10-01

    Kinesin spindle protein (KSP) is a microtubule-associated motor protein that is specifically expressed by mitosis cells. It is highly expressed in various types of tumors including hematomalignances and solid tumors. Chemical KSP inhibition has become a novel strategy in the development of anticancer drugs. SB743921 is a selective inhibitor for KSP, which is a mitotic protein essential for cell-cycle progression. Although SB743921 has shown antitumor activities for several types of cancers and entered into clinical trials, its therapeutic effects on breast cancer and mechanisms have not been explored. In this study, we tested the antitumor activity of SB743921 in breast cancer cell lines and partly elucidated its mechanisms. KSP and denticleless E3 ubiquitin-protein ligase homolog (DTL) are overexpressed in breast cancer cells compared with no-cancer tissues. Chemical inhibition of KSP by SB743921 not only reduces proliferation but also induces cell-cycle arrest and leads to apoptosis in breast cancer cells. Treatment of MCF-7 and MDA-MB-231 breast cancer cell lines with SB743921 results in decreased ability of colony formation in culture. SB743921 treatment also causes a KSP accumulation in protein level that is associated with cell arrest. Furthermore, we showed that SB743921 treatment significantly reduces the expression of bcl-2 and cell cycle-related protein DTL, and upregulates p53 and caspase-3 in breast cancer cells. Taken together, these data indicated that SB743921 can be expected to be a novel treatment agent for breast cancers. PMID:27379929

  15. KSP inhibitor SB743921 inhibits growth and induces apoptosis of breast cancer cells by regulating p53, Bcl-2, and DTL.

    Science.gov (United States)

    Zhu, Li; Xiao, Fengjun; Yu, Yue; Wang, Hua; Fang, Min; Yang, Yuefeng; Sun, Huiyan; Wang, Lisheng; Sheng, Yuan

    2016-10-01

    Kinesin spindle protein (KSP) is a microtubule-associated motor protein that is specifically expressed by mitosis cells. It is highly expressed in various types of tumors including hematomalignances and solid tumors. Chemical KSP inhibition has become a novel strategy in the development of anticancer drugs. SB743921 is a selective inhibitor for KSP, which is a mitotic protein essential for cell-cycle progression. Although SB743921 has shown antitumor activities for several types of cancers and entered into clinical trials, its therapeutic effects on breast cancer and mechanisms have not been explored. In this study, we tested the antitumor activity of SB743921 in breast cancer cell lines and partly elucidated its mechanisms. KSP and denticleless E3 ubiquitin-protein ligase homolog (DTL) are overexpressed in breast cancer cells compared with no-cancer tissues. Chemical inhibition of KSP by SB743921 not only reduces proliferation but also induces cell-cycle arrest and leads to apoptosis in breast cancer cells. Treatment of MCF-7 and MDA-MB-231 breast cancer cell lines with SB743921 results in decreased ability of colony formation in culture. SB743921 treatment also causes a KSP accumulation in protein level that is associated with cell arrest. Furthermore, we showed that SB743921 treatment significantly reduces the expression of bcl-2 and cell cycle-related protein DTL, and upregulates p53 and caspase-3 in breast cancer cells. Taken together, these data indicated that SB743921 can be expected to be a novel treatment agent for breast cancers.

  16. Fuzzy tandem repeats containing p53 response elements may define species-specific p53 target genes.

    Directory of Open Access Journals (Sweden)

    Iva Simeonova

    2012-06-01

    Full Text Available Evolutionary forces that shape regulatory networks remain poorly understood. In mammals, the Rb pathway is a classic example of species-specific gene regulation, as a germline mutation in one Rb allele promotes retinoblastoma in humans, but not in mice. Here we show that p53 transactivates the Retinoblastoma-like 2 (Rbl2 gene to produce p130 in murine, but not human, cells. We found intronic fuzzy tandem repeats containing perfect p53 response elements to be important for this regulation. We next identified two other murine genes regulated by p53 via fuzzy tandem repeats: Ncoa1 and Klhl26. The repeats are poorly conserved in evolution, and the p53-dependent regulation of the murine genes is lost in humans. Our results indicate a role for the rapid evolution of tandem repeats in shaping differences in p53 regulatory networks between mammalian species.

  17. P53 Gene Mutation and Expression of MDM2, P53, P16 Protein and their Relationship in Human Glioma

    Institute of Scientific and Technical Information of China (English)

    CUI Wen; WU Renliang; CAO Huiling; GAO Jifa; WANG Xu; REN Qiwei

    2005-01-01

    To investigate the effect of P53 protein accumulation and p53 gene mutation in the pathogenesis of glioma and to study the role of MDM2, P53 and P16 protein in glioma formation and progression and their relationship with each other, LSAB immunohistochemical staining method and non-isotopic PCR-SSCP techniques were used to detect the expression of MDM2, P53 and P16 pro tein and p53 gene mutation in 48 cases of gliomas. The results showed that the positive expression rate of MDM2, P53 and the negative rate of P16 was 22.9 %, 41.7 % and 60.4 %, respectively.The latter two in high grade (grade Ⅲ , Ⅳ) gliomas had a significantly higher rate than in the low grade (grade Ⅱ ) gliomas. Moreover, the co-expression of MDM2 and P53 protein was confirmed in only 1 of 48 cases. No significant difference was found in the rate of the expression of MDM2 between high grade and low grade gliomas (P>0.1) . PCR SSCP results showed that mutation of 5-8 exons of p53 gene was detected in 17 out of 48 cases (35.42 %) . Mutation was detected in 16of 20 cases of positive p53 expression, and another one was detected in 28 cases of negative expression cases. The correlation between p53 mutation and p53 immunopositivity was observed in 89.6% of the cases. P53 gene mutation and the level of MDM2, P53 and P16 protein were not related to age, gender of the patients, tumor location and size. It is concluded that the mutation of p53 and deletion of p16 might play important roles in the tumorigenesis of gliomas and it was significantly associated with the grade of tumor differentiation. P53 protein accumulation can indirectly reflect p53 mutation. MDM2 amplification and overexpression might be an early event in the growth of human gliomas.

  18. Transcription of five p53- and Stat-3-Inducible genes after ionizing radiation

    International Nuclear Information System (INIS)

    Ionizing radiation (IR) produces temporal- and dose-dependent changes in multiple gene mRNA targets that are potential biomarkers of radiation dose. We confirmed IR-induced changes in expression of gadd45a, ddb-2, and cdkn1a downstream transcripts of p53 by quantitative reverse transcription-polymerase chain reaction (QRT-PCR) assay in total RNA samples from the whole blood of radiotherapy patients undergoing total-body irradiation [Amundson, S.A., Grace, M.B., McLeland, C.B., Epperly, M.W., Yeager, A., Zhan, Q., Greenberger, J.S., Fornace Jr., A.J., 2004. Human in vivo radiation-induced biomarkers: gene expression changes in radiotherapy patients. Cancer Res. 64, 6368-6371.]. We now confirm dose-dependent up-regulation of bax in addition to these p53-dependent transcripts, and bcl-2, a downstream transcript of Stat-3, in ex vivo irradiated blood samples from healthy unrelated volunteers. Together these biomarkers represent pathways involved in growth arrest, DNA damage, and apoptosis. The objectives of this study were to (1) investigate the relationship between baseline mRNA expression levels, and (2) define expression patterns in response to IR in a large cohort (n=20). Whole-blood samples were irradiated ex vivo to measure gene expression in samples from (i) three healthy donors over a broad dose range (0, 0.25, 0.50, 0.75, 1, 2, and 3 Gy), and (ii) 20 healthy donors at two doses, 0.25 and 2.5 Gy. Expression level variance (σ2) of baseline values (0 Gy) showed negligible inter-individual variation with all values ≤1.0. σ2values=0.50bax, 0.25 bcl-2, 0.73 gadd45a, 0.66 cdkn1a, and 1.0 ddb-2. Meaningful IR dose-responses were observed for bax, gadd45a, and ddb-2 profiles and the ratio of bax:bcl-2 mRNA expression over a broad dose range. QRT-PCR studies were extended in the lower dose range (0, 0.1, 0.5, 0.75, and 1 Gy). Results showed that bax:bcl-2 ratio initially favors bax expression at doses of <1Gy, with IR-induced dose responses observed between 1 and 3

  19. p53 Gene and Tumorigenesis%p53基因与肿瘤形成

    Institute of Scientific and Technical Information of China (English)

    韩涛; 杨德吉

    2008-01-01

    肿瘤抑制基因的研究已经成为继癌基因之后肿瘤遗传学、分子生物学领域的前沿和热点,尤其是抑癌基因p53越来越被人们重视.研究表明正常的p53,又称野生型p53,在细胞损伤后的修复过程中发挥重要作用.正常p53的功能像"分子警察"一样监视着基因组DNA的完整性.在细胞发生DNA损伤时,p53蛋白能使细胞分裂终止在G1/S期,以使细胞有足够的时间修复损伤,恢复正常状态.若不能修复,野生型p53还能启动细胞的凋亡过程从而引发细胞的程序性死亡,阻止具有癌变倾向的突变细胞产生.而突变型p53基因会导致肿瘤的发生,大多数肿瘤与p53的突变有关.文章着重阐述了p53的表达与突变、p53的稳定调节及p53的转录调控等.

  20. Der Einfluss der Anästhetika Sevofluran und Propofol auf die Regulation der apoptoseassoziierten Proteine Bax, Bcl-2, Mdm-2 und p53 nach inkompletter zerebraler Hemisphärenischämie bei der Ratte

    OpenAIRE

    Bachl, Monika Maria

    2005-01-01

    Der Einfluss der Anästhetika Sevofluran und Propofol auf apoptoseassoziierte Proteine während zerebraler Ischämie ist bisher nicht erforscht. In der vorliegenden Studie wurden die Effekte dieser Narkotika auf die Regulation der Apoptosefaktoren Bax, Bcl-2, Mdm-2 und p53 bei 36 narkotisierten Sprague-Dawley-Ratten untersucht, bei denen eine inkomplette zerebrale Hemisphärenischämie mit anschließender Reperfusion induziert wurde. Die Apoptosefaktoren wurden mittels Immunfluoreszenz- und Western...

  1. 王氏连朴饮对脾胃湿热证模型大鼠胃黏膜 P53、BcI-2和 COX-2蛋白表达的影响%Effect of Wang's Lian Pu Decoction on Protein Expression of P53, Bcl -2 and COX -2 in Gastric Mucosa of Rat Model with Splenogastric Damp-heat Syndrome

    Institute of Scientific and Technical Information of China (English)

    黄琴; 王晶; 王和生; 王俊霞; 冯康; 谭芸

    2014-01-01

    Objective To observe the effect of Wang's Lian Pu Decoction(WLPD)on protein expression of proliferation and apoptosis correlated P53, Bcl-2, COX-2 genes in gastric mucosa of rat model wiht splenogastric damp-heat syndrome(SDHS),and to explore its possible therapeutic mechanism for SDHS. Methods Fifty Sprague Dawley rats were evenly divided into normal control group, model group, and high-, middle- and low-dosage WLPD groups (1.94,0.97,0.48 g·mL-1). SDHS rat model was established by the combined method of damp-heat environment and feeding with high fat and sugar diet and wine. The intervention with gastric gavage of WLPD was given simultaneously together with the modeling. The treatment lasted 7 days,and the effects of WLPD on protein expression levels of P53, Bcl-2 and COX-2 genes were observed. Results The protein expression of p53, Bcl-2 and COX-2 genes was localized in cytoplasm and their expression levels were significantly increased in the model group as compared to normal control group(P < 0.01). High-,middle- and low-dosage WLPD showed an effect on down-regulating the protein expression of P53,Bcl-2 and COX-2 genes to certain extent,and the middle-dose had the strongest effect, the difference being significant compared with the model group(P < 0.01). Conclusion WLPD may down-regulate the protein expression of P53,Bcl-2 and COX-2 genes in gastric mucosa of SDHS rats,correct the imbalance of the proliferation and apoptosis of gastric mucosa cells,thus has protective effect on the gastric mucosa.%目的:观察王氏连朴饮对脾胃湿热证模型大鼠胃黏膜增殖与凋亡相关 P53Bcl-2和 COX-2蛋白表达的影响,探讨该方治疗脾胃湿热证获效的可能作用机制。方法取 SD 大鼠50只,随机分为正常对照组,模型组,王氏连朴饮高、中、低剂量组(1.94,0.97,0.48 g·mL-1),共5组,每组10只。除正常组饲以普通饲料外,其余4组均以湿热环境加高脂高糖饮食和白酒综合法复

  2. Expression of p53 Target Genes in the Early Phase of Long-Term Potentiation in the Rat Hippocampal CA1 Area

    Science.gov (United States)

    Pustylnyak, Vladimir O.; Lisachev, Pavel D.; Shtark, Mark B.

    2015-01-01

    Gene expression plays an important role in the mechanisms of long-term potentiation (LTP), which is a widely accepted experimental model of synaptic plasticity. We have studied the expression of at least 50 genes that are transcriptionally regulated by p53, as well as other genes that are related to p53-dependent processes, in the early phase of LTP. Within 30 min after Schaffer collaterals (SC) tetanization, increases in the mRNA and protein levels of Bax, which are upregulated by p53, and a decrease in the mRNA and protein levels of Bcl2, which are downregulated by p53, were observed. The inhibition of Mdm2 by nutlin-3 increased the basal p53 protein level and rescued its tetanization-induced depletion, which suggested the involvement of Mdm2 in the control over p53 during LTP. Furthermore, nutlin-3 caused an increase in the basal expression of Bax and a decrease in the basal expression of Bcl2, whereas tetanization-induced changes in their expression were occluded. These results support the hypothesis that p53 may be involved in transcriptional regulation during the early phase of LTP. We hope that the presented data may aid in the understanding of the contribution of p53 and related genes in the processes that are associated with synaptic plasticity. PMID:25767724

  3. Expression of p53 Target Genes in the Early Phase of Long-Term Potentiation in the Rat Hippocampal CA1 Area

    Directory of Open Access Journals (Sweden)

    Vladimir O. Pustylnyak

    2015-01-01

    Full Text Available Gene expression plays an important role in the mechanisms of long-term potentiation (LTP, which is a widely accepted experimental model of synaptic plasticity. We have studied the expression of at least 50 genes that are transcriptionally regulated by p53, as well as other genes that are related to p53-dependent processes, in the early phase of LTP. Within 30 min after Schaffer collaterals (SC tetanization, increases in the mRNA and protein levels of Bax, which are upregulated by p53, and a decrease in the mRNA and protein levels of Bcl2, which are downregulated by p53, were observed. The inhibition of Mdm2 by nutlin-3 increased the basal p53 protein level and rescued its tetanization-induced depletion, which suggested the involvement of Mdm2 in the control over p53 during LTP. Furthermore, nutlin-3 caused an increase in the basal expression of Bax and a decrease in the basal expression of Bcl2, whereas tetanization-induced changes in their expression were occluded. These results support the hypothesis that p53 may be involved in transcriptional regulation during the early phase of LTP. We hope that the presented data may aid in the understanding of the contribution of p53 and related genes in the processes that are associated with synaptic plasticity.

  4. Prognostic Significance of Apoptosis Related Gene Family bcl-2 in Human Breast Cancer

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    To study the prognostic effect of bcl-2 oncogene and its gene family members bax, bcl-x expression in breast cancer patients. Methods: expression of bcl-2, bax proteins in 91 human breast cancer tissue sections were studied by immunohistochemical method. Bcl-x1 mRNA expression in frozen tissues from 16 breast cancer patients were detected using Northern blot method. Results: bcl-2 protein positivity was found in 60/91 (65.9%) patients, and bax positivity 59/91 (64.8%). Bcl-2 and bax expression levels were associated with apoptotic index(AI), histological grade, axillary lymph node metastasis, postoperative local recurrence and metastasis. Bcl-2 expression was related to ER positivity. In univariate analysis for disease free survival (DFS), bcl-2 and bax protein levels, and Al were all found to have prognostic value. The result of Cox's model multivariate analysis showed that bcl-2 protein level was an independent prognostic factor. In 16 frozen breast cancer tissues, 8/16(50%) had higher level of bcl-x1 mRNA, which showed correlation with bcl-2 protein expression and axillary lymph node metastasis. Conclusion: The findings indicate that dysregulated expressions of bcl-2, bax and bcl-x1 apoptosis-related genes, suggestive of serious deregulation of apoptotic process, may contribute to the biologic aggressiveness of breast cancer. Bcl-2 protein is an independent indicator of prognosis in breast cancer patients.

  5. Immunohistochemical study of cell proliferation, Bcl-2, p53, and caspase-3 expression on preneoplastic changes induced by cadmium and zinc chloride in the ventral rat prostate.

    OpenAIRE

    Arriazu, Riánsares; José M Pozuelo; Henriques-Gil, Nuno; Perucho, Teresa; Martín, Rocío; Rodríguez, Rosario; Santamaría, Luis

    2006-01-01

    KEYWORDS CLASSIFICATION: Animals;Apoptosis;biosynthesis;Biology;chemically induced;Cadmium;Cadmium Chloride;Carcinogens;Caspase 3;Caspases;Cell Proliferation;Chlorides;Immunohistochemistry;metabolism;Male;mechanisms of carcinogenesis;pathology;pharmacology;Precancerous Conditions;Proliferating Cell Nuclear Antigen;Prostate;Prostatic Intraepithelial Neoplasia;Prostatic Neoplasms;Proteins;Proto-Oncogene Proteins;Proto-Oncogene Proteins c-bcl-2;Rats;Rats,Sprague-Dawley;Research;Spain;toxicity;Ti...

  6. Gene expression profiles resulting from stable loss of p53 mirrors its role in tissue differentiation.

    Directory of Open Access Journals (Sweden)

    Oliver Couture

    Full Text Available The tumor suppressor gene p53 is involved in a variety of cellular activities such as cellular stress responses, cell cycle regulation and differentiation. In our previous studies we have shown p53's transcription activating role to be important in osteoblast differentiation. There is still a debate in the literature as to whether p53 inhibits or promotes differentiation. We have found p53 heterozygous mice to show a p53 dependency on some bone marker gene expression that is absent in knockout mice. Mice heterozygous for p53 also show a higher incidence of osteosarcomas than p53 knockout mice. This suggests that p53 is able to modify the environment within osteoblasts. In this study we compare changes in gene expression resulting after either a transient or stable reduction in p53. Accordingly we reduced p53 levels transiently and stably in C2C12 cells, which are capable of both myoblast and osteoblast differentiation, and compared the changes in gene expression of candidate genes regulated by the p53 pathway. Using a PCR array to assay for p53 target genes, we have found different expression profiles when comparing stable versus transient knockdown of p53. As expected, several genes with profound changes after transient p53 loss were related to apoptosis and cell cycle regulation. In contrast, stable p53 loss produced a greater change in MyoD and other transcription factors with tissue specific roles, suggesting that long term loss of p53 affects tissue homeostasis to a greater degree than changes resulting from acute loss of p53. These differences in gene expression were validated by measuring promoter activity of different pathway specific genes involved in differentiation. These studies suggest that an important role for p53 is context dependent, with a stable reduction in p53 expression affecting normal tissue physiology more than acute loss of p53.

  7. Effect of p53 genotype on gene expression profiles in murine liver

    International Nuclear Information System (INIS)

    The tumor suppressor protein p53 is a key regulatory element in the cell and is regarded as the 'guardian of the genome'. Much of the present knowledge of p53 function has come from studies of transgenic mice in which the p53 gene has undergone a targeted deletion. In order to provide additional insight into the impact on the cellular regulatory networks associated with the loss of this gene, microarray technology was utilized to assess gene expression in tissues from both the p53-/- and p53+/- mice. Six male mice from each genotype (p53+/+, p53+/-, and p53-/-) were humanely killed and the tissues processed for microarray analysis. The initial studies have been performed in the liver for which the Dunnett test revealed 1406 genes to be differentially expressed between p53+/+ and p53+/- or between p53+/+ and p53-/- at the level of p ≤ 0.05. Both genes with increased expression and decreased expression were identified in p53+/- and in p53-/- mice. Most notable in the gene list derived from the p53+/- mice was the significant reduction in p53 mRNA. In the p53-/- mice, not only was there reduced expression of the p53 genes on the array, but genes associated with DNA repair, apoptosis, and cell proliferation were differentially expressed, as expected. However, altered expression was noted for many genes in the Cdc42-GTPase pathways that influence cell proliferation. This may indicate that alternate pathways are brought into play in the unperturbed liver when loss or reduction in p53 levels occurs

  8. Expression of TP53, BCL-2, and VEGFA Genes in Esophagus Carcinoma and its Biological Significance

    OpenAIRE

    Wei, Wei; Wang, Yanqin; YU, XIAOMING; Ye, Lan; Jiang, Yuhua; Cheng, Yufeng

    2015-01-01

    Background The pathogenesis of esophagus carcinoma involves a cascade process consisting of multiple factors and accumulation of gene mutations. It is known that vascular endothelial growth factor (VEGF) mainly regulates de novo vascular formation while B-cell lymphoma-2 (BCL-2) gene exerts a tumor-suppressing effect. The prominent expression of VEGFA and BCL-2 genes, along with the most famous tumor-suppressor gene, TP53, raise the possibly of gene interaction. This study therefore investiga...

  9. p53 gene in treatment of hepatic carcinoma:Status quo

    Institute of Scientific and Technical Information of China (English)

    Yong-Song Guan; Zi La; Lin Yang; Qing He; Ping Li

    2007-01-01

    Hepatocellular carcinoma(HCC)is one of the 10 most common cancers worldwide.There is no ideal treatment for HCC yet and many researchers are trying to improve the effects of treatment by changing therapeutic strategies.As the majority of human cancers seem to exhibit either abnormal p53 gene or disrupted p53 gene activation pathways,intervention to restore wild-type p53 (wt-p53)activities is an attractive anti-cancer therapy including HCC.Abnormalities of p53 are also considered a predisposition factor for hepatocarcinogenesis.p53 is frequently mutated in HCC.Most HCCs have defects in the p53-mediated apoptotic pathway although they carry wt-p53.High expression of p53 in vivo may exert therapeutic effects on HCC in two aspects:(1)High expression of exogenous p53 protein induces apoptosis of tumor cells by inhibiting proliferation of cells through several biologic pathways and(2)Exogenous p53 renders HCC more sensitive to some chemotherapeutic agents.Several approaches have been designed for the treatment of HCC via the p53 pathway by restoring the tumor suppression function from inactivation,rescuing the mutated p53 gene from instability,or delivering therapeutic exogenous p53.Products with p53 status as the target have been studied extensively in vitro and in vivo.This review elaborates some therapeutic mechanisms and advances in using recombinant human adenovirus p53 and oncolytic virus products for the treatment of HCC.

  10. Tumor protein translationally controlled 1 is a p53 target gene that promotes cell survival

    OpenAIRE

    Chen, Weimin; Wang, Huihui; Tao, Shasha; Zheng, Yi; Wu, Wei; Lian, Fangru; Jaramillo, Melba; Fang, Deyu; Zhang, Donna D.

    2013-01-01

    Tumor suppressor p53 maintains genome stability by differentially activating target genes that control diverse cellular responses, such as the antioxidant response, cell cycle arrest and apoptosis. Despite the fact that many p53 downstream genes have been well characterized, novel p53 target genes are continuously being identified. Here, we report that Tpt1 is a direct target gene of p53. We found that p53 upregulates the transcription of Tpt1 and identified a p53-responsive element in the pr...

  11. Apoptosis regulatory protein,survivin,expression and relationship with bcl-2 protien in pituitary adenoma%Survivin凋亡抑制基因在垂体腺瘤中的表达及其与bcl-2p53相关性的研究

    Institute of Scientific and Technical Information of China (English)

    马杰; 魏冰; 乔思杰

    2002-01-01

    目的: 探讨凋亡抑制基因survivin在垂体腺瘤中的表达,及其与bcl-2p53表达蛋白的相关性.方法: 采用免疫组织化学链霉菌抗生物素蛋白-过氧化酶连接法(SP法),检测survivin、bcl-2p53基因表达蛋白在8例正常垂体组织及38例垂体腺瘤组织中的表达.结果: survivin基因表达蛋白在正常垂体中无表达,38例垂体腺瘤中,23例表达阳性,占60.5%病理分型中PRL型、GH型、混合型阳性表达率分别为12/17、7/13、4/8三者比较,差异无显著性(P>0.05).垂体腺瘤bcl-2表达蛋白的阳性与阴性中,survivin蛋白表达阳性率分别为15/17、8/21.两者比较,差异有显著性(P<0.05):而p53表达蛋白的阳性和阴性中,survivin蛋白表达阳性率分别为2/6,22/23,两者相比,差异无显著性(P>0.05):survivin基因蛋白的表达阳性率与垂体腺瘤组织中的bcl-2蛋白表达密切相关,与p53蛋白表达无相关性.结论: survivin蛋白表达的异常而引起细胞凋亡抑制,在垂体腺瘤的发生中起一定作用,其过度表达提示垂体腺瘤增生极度活跃,survivin蛋白表达与垂体腺瘤中bcl-2蛋白的异常表达密切相关.

  12. p53, Bcl-2 and cox-2 are involved in berberine hydrochloride-induced apoptosis of HeLa229 cells.

    Science.gov (United States)

    Wang, Hai-Yan; Yu, Hai-Zhong; Huang, Sheng-Mou; Zheng, Yu-Lan

    2016-10-01

    The present study aimed to investigate the effects of berberine hydrochloride on the proliferation and apoptosis of HeLa229 human cervical cancer cells. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed to examine the cytotoxicity of berberine hydrochloride against HeLa229 cells. The effects of berberine hydrochloride on the apoptosis of HeLa229 cells was detected by immunofluorescence and flow cytometry, and the mRNA expression levels of p53, B‑cell lymphoma 2 (Bcl‑2) and cyclooxygenase‑2 (cox‑2) were analyzed by reverse transcription-quantitative polymerase chain reaction. Berberine hydrochloride inhibited the proliferation of HeLa229 cells in a dose‑dependent manner; minimum cell viability (3.61%) was detected following treatment with 215.164 µmol/l berberine hydrochloride and the half maximal inhibitory concentration value was 42.93 µmol/l following treatment for 72 h. In addition, berberine hydrochloride induced apoptosis in HeLa229 cells in a dose‑ and time‑dependent manner. Berberine hydrochloride upregulated the mRNA expression levels of p53, and downregulated mRNA expression levels of Bcl‑2 and cox‑2, in a dose‑dependent manner. In conclusion, berberine hydrochloride inhibited the proliferation and induced apoptosis of HeLa229 cells, potentially via the upregulation of p53 and the downregulation of Bcl‑2 and cox‑2 mRNA expression levels. PMID:27601129

  13. Modulation of p53β and p53γ expression by regulating the alternative splicing of TP53 gene modifies cellular response

    OpenAIRE

    Marcel, V; Fernandes, K; Terrier, O; LANE, D. P.; Bourdon, J-C

    2014-01-01

    In addition to the tumor suppressor p53 protein, also termed p53α, the TP53 gene produces p53β and p53γ through alternative splicing of exons 9β and 9γ located within TP53 intron 9. Here we report that both TG003, a specific inhibitor of Cdc2-like kinases (Clk) that regulates the alternative splicing pre-mRNA pathway, and knockdown of SFRS1 increase expression of endogenous p53β and p53γ at mRNA and protein levels. Development of a TP53 intron 9 minigene shows that TG003 treatment and knockdo...

  14. Study on the Regulation of Bcl-2 Gene on Rat Spermatogenic Cells Apoptosis in Transcription Level

    Institute of Scientific and Technical Information of China (English)

    董强; 杨宇如; 黄明孔; 李虹; 张卫东; 徐震波

    2000-01-01

    Objective To detect the change of Bcl-2 gene expression in the apopototic process of spermatogenic cells in rat with vasoligation and vasostomy, and to find out the relationship between the transcription of Bcl-2 and the apoptosis of spermatognic cells.Materials & Methods Sixty adult male Sprague-Dawley rats in 3 groups were operated with vasoligation and vasostomy. Then hybridization in situ with hypersensitive Bcl-2 RNA probe was used to detect the change of Bcl-2 mRNA.Results The transcription of Bcl-2 gene in spermatogenic cells was obviously inhibited in the vasoligation group compared with that in the control group (P<0. 05), and the transcription in the vasostomy group showed no difference from that of the control group.Conclusion Bcl-2 gene has an anti-apoptotic effect in rats with vasostomy, and there was a transcriptional regulation of Bcl-2 gene in rat spermatogenic cell during the period of pre-vasoligation to post-vasoligation and to post-vasosotomy.

  15. Correlation of primary tumor size and axillary nodal status with tumor suppressor gene p53 in breast carcinoma

    Directory of Open Access Journals (Sweden)

    Topić Brano

    2002-01-01

    Full Text Available Correlation of standard path morphological prognostic parameters, primary tumor size and axillary nodal status with new prognostic factor in breast carcinoma: tumor suppressor gene p53 was analyzed. The studied sample included 65 women who underwent surgery for breast carcinoma at the Surgical Clinic of Clinical Center Banja Luka, from January 1st 1997 till January 1st 1999. Statistical data analysis was performed and correlation of prognostic factors was determined. The majority of authors in this field agree that the primary tumor size and axillary nodal status are the two most important prognostic factors. These factors are the best predictors of prognosis and survival of women who had the tumor and were operated on. Tumor markers were immunohistochemically determined in the last ten years and, according to the majority of authors, are still considered the additional or relative prognostic factors in breast carcinoma. Their prognostic value and significance increase almost daily. Most frequently determined tumor markers are bcl-2, pS2, Ki-67 and p53. There was a positive, directly proportional relationship between primary tumor size and tumor suppressor gene p53, but there was no positive correlation between the axillary nodal status and tumor suppressor gene p53. Significance of determination of new tumor markers as the prognostic factors was emphasized. These markers represent a powerful tool in the early detection and prevention of breast carcinoma.

  16. EFFECTIVE NEW CANCER THERAPIES WHICH ARE INDEPENDENT OF P53 GENE STATUS

    OpenAIRE

    Takahashi, Akihisa; Ohnishi, Ken; Kondo, Natsuko; Mori, Eiichiro; Noda, Taichi; Ohnishi, Takeo

    2010-01-01

    The gene product of the tumor suppressor gene p53 is known to play an important role in cancer therapy. The p53 molecule induces cell-cycle arrest, apoptosis and DNA repair after cells are subjected to cancer therapies involving ionizing radiation, hyperthermia and anti-cancer drugs. Patients with cancers bearing mutated (m) p53 or deleted p53 gene often have a poorer prognosis than those with cancers bearing wild-type (wt) p53 gene. We reported that efficient cell lethality by ionizing radia...

  17. Co-mutation of p53, K-ras genes and accumulation of p53 protein and its correlation to clinicopathological features in rectal cancer

    Institute of Scientific and Technical Information of China (English)

    Zhi-Zhong Pan; De-Sen Wan; Gong Chen; Li-Ren Li; Zhen-Hai Lu; Bi-Jun Huang

    2004-01-01

    AIM: To determine the accuracy of p53 gene mutations predicted by overexpression of p53 protein immunohistochemically,and to investigate the co-mutation of p53 and K-rasgenes in rectal cancer and its effect on promoting malignant biologic behaviors of tumors.METHODS: Ninety-seven specimens of rectal cancer were surgically resected in our hospital from August 1996 to October 1997. The hot mutation areas of p53 gene (in exons 5-8) and K-ras gene (in codon 5/12 and 13) were detected with polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), and overexpression of p53 protein was detected with immunohistochemistry (IHC) in the 97 specimens of rectal cancer. Correlation between gene mutations and tumor clinicopathologic factors was studied, and survival analysis was penfomed as well.RESULTS: There were 36 cases of p53 gene mutations in 61 p53 protein positive cases, and 21 cases of p53 gene non-mutation in 36 p53 protein negative cases respectively.The coincidence rate of p53 gene mutation by IHC method with PCR-SSCP method was 58.8% (57/97). The mutation rate of p53 gene was 52.6% (51/97), while K-ras gene mutation was observed in codons 12 and 13 in 61 cases with a mutation rate of 62.9% (61/97). Single gene mutation of p53 or K-raswas found in 32 cases. Both p53 and K-ras gene mutation were found in 48 cases. Statistical analysis showed that p53 and K-rasgene mutations were not related to the clinicopathologic factors, including tumor size, gross tumor type, histological classification, differentiation, invasion to intestinal veins, lymphatics and nerves, invasive depth to wall, lymph node metastasis, and Dukes' stages (P>0.05).The survival in patients with no gene mutation, single gene mutation and both gene mutations were similar (P>0.05).CONCLUSION: IHC has a certain false positive and false negative rate in detecting p53 gene mutations. Malignant biological behaviours of rectal cancer are not enhanced by p53 and K-rasgene mutations. Co

  18. Expression of Bcl-2 Gene in Primary Breast Cancer and its Correlation with Some Prognostic Factors

    Directory of Open Access Journals (Sweden)

    * A. Tavakoli, M.D

    Full Text Available Abstract Background and purpose: The breast cancer is the most common malignancy in women. Bcl-2 expression has been determined in more than half of the cases of breast cancer. The purpose of this study was to determine the expression of bcl-2 gene in primary breast cancer and its correlation with grade, stage and axillary lymph node involvement.Materials and Methods: The study was a cross-sectional one that was performed on 75 patients with breast cancer admitted to Mostafa Khomeini hospital (2000-2005. After preparing the samples, a tissue section from each sample was obtained. One of the tumoral sections and one of the lymph node sections were stained using H & E. We determined the type of the tumor, the number of lymph nodes, the stage and the grade of the tumor. We studied Bcl-2 with polyclonal antibody by IHC.Results: Our study showed that 69.3% of patients had hymph node involvment. In addition, 41.3% of samples were positive for Bcl-2, 58.7% of samples were in stage II and many patients (42.7% were in grade III. In this study, we didn’t find any relationship between bcl-2 and stage and lymph node involvment. We also found a significant association between bcl-2 and grade (P<0.006. Also, high bcl-2 expression was more frequent in high-grade tumor.Conclusion: According to the results obtained from earlier studies and our study, it seems that bcl2 is a prognostic factor in breast cancer. But further investigations with more specimens and long-time follow-up are required to clarify the exact role of Bcl-2 in the prognosis of breast cancer.

  19. Interaction of hepatitis B virus with tumor suppressor gene p53: its significance and biological function

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The mechanism of the interaction of hepatitis B virus (HBV) with tumor suppressor p53 and its role in the hepatocarcinogenesis have been studied by PCR-directed sequencing, gel shift assays and in situ ultraviolet cross-linking assay. The biological function of the interaction of HBV with p53 gene was investigated by co-transfection of chloramphenicol acetyltransferase (CAT) reporter gene, p53 and HBV DNA, and quantitative PCR. Among the 16 primary hepatocellular carcinoma (PHC) samples, 13 were HBV-DNA positive,10 HBxAg positive and 9 p53 protein positive. The p53 gene point mutation was found in 5 samples, one of which had a G to T substitution located at codon 249. After analyzing the HBV genome by a computer program, a p53 response element binding sequence was found in HBV genome at upstream of enhancer I, from 1047 to 1059 nucleotides. This sequence could specifically bind to p53 protein, increase p53 protein accumulation in the PHC cells and stimulate the transactivating activity of p53 and HBV replication .The results also revealed that HBxAg could combine with p53 protein to form a complex in the cells and enhance CAT expression. Immunocytochemical staining showed that p53 protein complex was located in the cytoplasm and the process of p53 entry to nuclei was, in part, blocked. From our results, we conclude that the mutation of p53 gene at codon 249 is infrequent in HBV-associated PHC, the DNA-protein binding between HBV and p53, and the protein-protein binding between HBxAg and p53 might lead to the reduction or inactivation of p53 protein, which in turn resulting in HBV-associated hepatocarcinogenesis.

  20. Effect of basic fibroblast growth factor and danshen on bcl-2 and p53 mRNA expression in the brain of rats exposed to repeated,high,positive acceleration(+Gz)

    Institute of Scientific and Technical Information of China (English)

    Hongjin Liu; Qing Cai

    2008-01-01

    BACKGROUND:Both animal experiments and clinical studies have shown that basic fibroblast growth factor(bFGF)and danshen(Salvia miltiorrhiza)can exhibit protective effects on ischemia-reperfusion cerebral injury.OBJECTIVE:To test whether bFGF and danshen can protect cerebral injury induced by exposure to repeated,high,positive acceleration(+Gz)in an animal model and to analyze the possible mechanisms.DESIGN,TIME AND SETTING:Randomized controlled animal study.The experiment was performed at the Research Center for Molecular Biology,Air-force General Hospital of Chinese PLA from April to August 2000.MATERIALS:A total of 20 clean grade,healthy,Sprague Dawley rats of both genders,weighing(200±15)g,were provided by our experimental animal center.Rats were randomly divided into 5 groups:the control group,+Gz exposure group,bFGF group,danshen group,and saline group,with 4 animals per group.bFGF(Beijing Bailuyuan Biotechnology Co.Ltd.)and danshen solution(Shanghai Zhongxi Pharmaceutical Co.Ltd.)were used.METHODS:All rats were fixed on a rotary arm of a centrifugal apparams(2 m in radius)with their heads oriented towards the center of the apparatus.Except for rats in the control group.the value of+Gz exposure was+14 Gz with an acceleration rate of 1.5 G/s.The peak force lasted for 45 seconds.+Gz exposure was performed three times with intervals of 30 minutes.Rats in the control group received the same+Gz procedure,but the G value was+1 Gz.Rats in bFGF group and danshen group were intraperitoneally injected with 100 μg/kg bFGF or 15 g/kg danshen solution,respectively,at 30 minutes prior to centrifugation and immediately after tentrifugation.Rats in saline group were injected with the same volume of saline.Six hours after exposure,rats were decapitated.One hemisphere was preserved in liquid nitrogen for RNA extraction and the other was processed for apoptosis detection.MAIN OUTCOME MEASURES:mRNA levels of bcl-2 and p53 were measured by semi-quantitative reverse

  1. Adenovirus Ad-p53AIP1-mediated gene therapy and its regulation of p53-MDM2 interactions

    OpenAIRE

    Jiang, Yunbo; Chen, Huihua; JIA, HAIQUAN; XU, YUANJI; Liu, Gang; Wang, Yan; Yang, Xiaohe; Yinglin LU

    2010-01-01

    We generated replication-defective adenovirus Ad-p53AIP1 and studied its anti-tumor efficacy both in vitro and in vivo. We demonstrated that Ad-p53AIP1 infection elicited high levels of p53AIP1 expression in cancer cells. We also found that Ad-p53AIP1 expression induced marked apoptosis and cell cycle arrest in HepG2 cells. Moreover, Ad-p53AIP1 infection significantly inhibited the tumorigenesis of 4T1 mouse mammary cancer cells in vivo. In particular, we discovered that p53AIP1 overexpressio...

  2. Gene expression of P53 and adipoq as diagnostic markers for colorectal cancer

    OpenAIRE

    Nadhum Jalal Ismaiel; Rozhgar Abdullah Mohammed; Hazha Jamal Hidayat

    2016-01-01

    Purpose: Colorectal cancer is the most frequent cause of death and had high mortality rate in Western world. It is from complex, variable and patient- specific interaction between genetic, epigenetic and environmental factors. In the present study, we aimed to investigate the contribution of gene expression of the P53 and Adipoq, both genes to the risk of colorectal cancer. P53 gene is a tumor suppressor gene, encoded protein of P53 is a transcription factor and its pivotal role in maintaini...

  3. Exclusive Association of p53 Mutation with Super-High Methylation of Tumor Suppressor Genes in the p53 Pathway in a Unique Gastric Cancer Phenotype

    OpenAIRE

    Mina Waraya; Keishi Yamashita; Akira Ema; Natsuya Katada; Shiro Kikuchi; Masahiko Watanabe

    2015-01-01

    Background A comprehensive search for DNA methylated genes identified candidate tumor suppressor genes that have been proven to be involved in the apoptotic process of the p53 pathway. In this study, we investigated p53 mutation in relation to such epigenetic alteration in primary gastric cancer. Methods The methylation profiles of the 3 genes: PGP9.5, NMDAR2B, and CCNA1, which are involved in the p53 tumor suppressor pathway in combination with p53 mutation were examined in 163 primary gastr...

  4. High-level expression of wild-type p53 in melanoma cells is frequently associated with inactivity in p53 reporter gene assays.

    Directory of Open Access Journals (Sweden)

    Roland Houben

    Full Text Available BACKGROUND: Inactivation of the p53 pathway that controls cell cycle progression, apoptosis and senescence, has been proposed to occur in virtually all human tumors and p53 is the protein most frequently mutated in human cancer. However, the mutational status of p53 in melanoma is still controversial; to clarify this notion we analysed the largest series of melanoma samples reported to date. METHODOLOGY/PRINCIPAL FINDINGS: Immunohistochemical analysis of more than 180 melanoma specimens demonstrated that high levels of p53 are expressed in the vast majority of cases. Subsequent sequencing of the p53 exons 5-8, however, revealed only in one case the presence of a mutation. Nevertheless, by means of two different p53 reporter constructs we demonstrate transcriptional inactivity of wild type p53 in 6 out of 10 melanoma cell lines; the 4 other p53 wild type melanoma cell lines exhibit p53 reporter gene activity, which can be blocked by shRNA knock down of p53. CONCLUSIONS/SIGNIFICANCE: In melanomas expressing high levels of wild type p53 this tumor suppressor is frequently inactivated at transcriptional level.

  5. THE EXPRESSION AND CLINICAL VALUE OF APOPTOSIS CONTROL GENE Bcl-2 AND Bax IN BREAST CANCER

    Institute of Scientific and Technical Information of China (English)

    ZHENG Jun; YAO Zhen-xiang; ZHANG Jing

    1999-01-01

    Objective: To study the expression and clinical value of apoptosis control gene bcl-2 and bax in breast cancer.Methods: Protein bax and bcl-2 in 41 breast cancers obtained from operations in our hospital in 1996 were detected using ABC immunohistochemical stain assay and compared with 10 cases with normal breast tissues.Results: The positive rate of bax in normal breast tissue was 90% and in breast cancer was 59%, with a significant statistical difference between them (P<0.05), but there was no statistical difference in bcl-2 protein expression. Among the 41 breast cancer, the group with lymph node metastasis (21 cases) had obviously low bax expression (43%) and high bcl-2 expression (76%), showing significant difference to the group without lymph node metastasis (P<0.05).Conclusion: The antiapoptosis function of bcl-2 was stronger than bax in breast cancer. Protein bax and bcl-2 assay may be useful in understanding the biological behaviors of breast cancer.

  6. Identification, clonong and characterization of the p53 induced gene human wig-1

    OpenAIRE

    Hellborg, Fredrik

    2004-01-01

    The tumor suppressor p53 is a transcription factor that responds to various kinds of cellular stress. In respons to the sensed stress it is able to induces cell cycle arrest and apoptosis. In order to achieve these effects it transactivates target genes. Thus knowledge about p53 target genes and their function is vital for the understandnig of this important tumor suppressor. We previously identified a novel p53-induced mouse gene, wig-1, that encodes a 290 amino acid zin...

  7. Mutations of p53 gene exons 4-8 in human esophageal cancer

    Institute of Scientific and Technical Information of China (English)

    Li-Ya Li; Jin-Tian Tang; Li-Qun Jia; Pei-Wen Li

    2005-01-01

    AIM: To characterize the tumor suppressor gene p53 mutations in exon 4, esophageal cancer and adjacent noncancerous tissues.METHODS: We performed p53 (exons 4-8) gene mutation analysis on 24 surgically resected human esophageal cancer specimens by PCR, single-strand conformation polymorphism, and DNA sequencing. RESULTS: p53 gene mutations were detected in 9 of 22 (40.9%) esophageal cancer specimens and 10 of 17 (58.8%) adjacent non-cancerous tissues. Eight of sixteen (50.0%) point mutations detected were G-A transitions and 9 of 18 (50.0%) p53 gene mutations occurred in exon 4 in esophageal cancer specimens. Only 1 of 11 mutations detected was G-A transition and 4 of 11 (36.4%) p53 gene mutations occurred in exon 4 in adjacent non-cancerous tissues.CONCLUSION: Mutation of p53 gene in exon 4 may play an important role in development of esophageal cancer. The observation of p53 gene mutation in adjacent noncancerous tissues suggests that p53 gene mutation may be an early event in esophageal carcinogenesis. Some clinical factors, including age, sex, pre-operation therapy and location of tumors, do not influence p53 gene mutation rates.

  8. Common Patterns of Bcl-2 Family Gene Expression in Two Traumatic Brain Injury Models

    OpenAIRE

    Strauss, Kenneth I.; NARAYAN, RAJ K.; Raghupathi, Ramesh

    2004-01-01

    Cell death/survival following traumatic brain injury (TBI) may be a result of alterations in the intracellular ratio of death and survival factors. Bcl-2 family genes mediate both cell survival and the initiation of cell death. Using lysate RNase protections assays, mRNA expression of the anti-cell death genes Bcl-2 and Bcl-xL, and the pro-cell death gene Bax, was evaluated following experimental brain injuries in adult male Sprague-Dawley rats. Both the lateral fluid-percussion (LFP) and the...

  9. 重组人促红细胞生成素对慢性脑缺血大鼠学习记忆能力及凋亡相关蛋白P53Bcl-2表达的影响%Effects of recombinant human erythropoietin on learning and memory abilities and expressions of P53 and Bcl-2 proteins in rats induced by chronic cerebral ischemia

    Institute of Scientific and Technical Information of China (English)

    周彦慧; 郭军红; 王慧芳; 张金

    2013-01-01

    Objective To study the effects of recombinant human erythropoietin (rhEPO) on learning and memory functions and expressions of apoptosis-related proteins (P53 and Bcl-2) in rats induced by chronic cerebral ischemia.Methods Sixteen healthy male SD rats were randomly divided into control group and experimental group (n=8); the permanent bilateral occlusion of common carotid arteries in these rats was adopted to establish the chronic cerebral ischemia models; rats in the experimental group weekly received intranasal rhEPO delivery at the dose of 150 U/125 μL after chronic ischemia for 3 days,whereas models in the control group accepted equivalent volume of saline at the same time.Eight weeks after the inducement,Morris water maze test was performed to evaluate the movement and the spatial learning and memory capabilities.Morphology changes of cerebral cortex and hippocampal CA1 nerve cells were observed by HE staining.P53 and Bcl-2 proteins levels were detected by immunohistochemistry.The number of apoptotic cells was detected by means of TUNEL.Results Morris water maze test showed that shorter escape latency and higher frequency through platform in the experimental group were noted as compared with those in the control group (P<0.05).HE staining indicated that less pyramidal cells and more serious karyopyknosis changes of cerebral cortex and hippocampal CA1 nerve cells and thinner cerebral cortex in control group were noted as compared with those in the experimental group (P<0.05).Immunohistochemistry indicated that the experiment group had increased Bal-2 expression and mean gray value of P53 as compared with control group (P<0.05).TUNEL showed that the apoptotic cells of control group were significantly increased as compared with those in the experimental group (P<0.05).Conclusion The rhEPO can improve the abilities of movement,memory and spatial orientation in rats induced by chronic cerebral ischemia,whose mechanism might be related to the restrain

  10. GROWTH INHIBITION OF HUMAN LARYNGEAL CANCER CELL WITH THE ADENOVIRUS-MEDIATED p53 GENE

    Institute of Scientific and Technical Information of China (English)

    WANG Qi; HAN De-min; WANG Wen-ge; WU Zu-ze; ZHANG Wei

    1999-01-01

    Objective: In most laryngeal cancers, the function of p53 gene is down regulated. To explore the potential use of p53 in gene therapy of laryngeal cancer, by introducing wild-type p53 into laryngeal cancer cell line via a recombinant adenoviral vector, Ad5CMV-p53 and analyzing its effects on cell and tumor growth. Methods: A human laryngeal cancer cell line Hep-2 was used.Recombinant cytomegalovirus-promoted adenoviruses containing human wild-type p53 cDNA was transiently introduced into Hep-2 line. The growth suppression of the Hep-2 cells and established s.c. squamous carcinoma model was examined. The p53 protein expression was detected using immunohistochemical analysis. Results: The transduction efficiencies of Hep-2 cell line were 100% at a multiplicity of 100 or greater. The p53 protein expression peaked on day 2 after infection and lasted far 5 days. In vitro growth assays revealed cell death following Ad5CMV-p53 infected. In vivo studies, Ad5CMV-p53 inhibited the tumorigenicity of Hep-2 cell, and in nude mice with established s.c. squamous carcinoma nodules showed that tumor volumes were significantly reduced in mice that received peritumoral infiltration of Ad5CMV-p53. Conclusion: Adenovirus-mediated antitumor therapy carrying the p53 gene is an efficient method to inhibit laryngeal cancer growth. Transfection of laryngeal cancer cells with the wild-type p53 gene via Ad5CMV-p53 is a potential novel approach to the therapy of laryngeal cancer.

  11. Alterations in tumour suppressor gene p53 in human gliomas from Indian patients

    Indian Academy of Sciences (India)

    Pornima Phatak; S Kalai Selvi; T Divya; A S Hegde; Sridevi Hegde; Kumaravel Somasundaram

    2002-12-01

    Alterations in the tumour suppressor p53 gene are among the most common defects seen in a variety of human cancers. In order to study the significance of the p53 gene in the genesis and development of human glioma from Indian patients, we checked 44 untreated primary gliomas for mutations in exons 5–9 of the p53 gene by PCR-SSCP and DNA sequencing. Sequencing analysis revealed six missense mutations. The incidence of p53 mutations was 13.6% (6 of 44). All the six mutations were found to be located in the central core domain of p53, which carries the sequence-specific DNA-binding domain. These results suggest a rather low incidence but a definite involvement of p53 mutations in the gliomas of Indian patients.

  12. Genome-scale functional analysis of the human genes modulating p53 activity by regulating MDM2 expression in a p53-independent manner.

    Science.gov (United States)

    Kim, Dong Min; Choi, Seung-Hyun; Yeom, Young Il; Min, Sang-Hyun; Kim, Il-Chul

    2016-09-16

    MDM2, a critical negative regulator of p53, is often overexpressed in leukemia, but few p53 mutations are found, suggesting that p53-independent MDM2 expression occurs due to alterations in MDM2 upstream regulators. In this study, a high MDM2 transcription level was observed (41.17%) regardless of p53 expression in patient with acute myeloid leukemia (AML). Therefore, we performed genome-scale functional screening of the human genes modulating MDM2 expression in a p53-independent manner. We searched co-expression profiles of genes showing a positive or negative pattern with MDM2 expression in a DNA microarray database, selected1089 links, and composed a screening library of 368 genes. Using MDM2 P1 and P2 promoter-reporter systems, we screened clones regulating MDM2 transcriptions in a p53-independent manner by overexpression. Nine clones from the screening library showed enhanced MDM2 promoter activity and MDM2 expression in p53-deficient HCT116 cells. Among them, six clones, including NTRK2, GNA15, SFRS2, EIF5A, ELAVL1, and YWHAB mediated MAPK signaling for expressing MDM2. These results indicate that p53-independent upregulation of MDM2 by increasing selected clones may lead to oncogenesis in AML and that MDM2-modulating genes are novel potential targets for AML treatment. PMID:27524244

  13. Genome-scale functional analysis of the human genes modulating p53 activity by regulating MDM2 expression in a p53-independent manner.

    Science.gov (United States)

    Kim, Dong Min; Choi, Seung-Hyun; Yeom, Young Il; Min, Sang-Hyun; Kim, Il-Chul

    2016-09-16

    MDM2, a critical negative regulator of p53, is often overexpressed in leukemia, but few p53 mutations are found, suggesting that p53-independent MDM2 expression occurs due to alterations in MDM2 upstream regulators. In this study, a high MDM2 transcription level was observed (41.17%) regardless of p53 expression in patient with acute myeloid leukemia (AML). Therefore, we performed genome-scale functional screening of the human genes modulating MDM2 expression in a p53-independent manner. We searched co-expression profiles of genes showing a positive or negative pattern with MDM2 expression in a DNA microarray database, selected1089 links, and composed a screening library of 368 genes. Using MDM2 P1 and P2 promoter-reporter systems, we screened clones regulating MDM2 transcriptions in a p53-independent manner by overexpression. Nine clones from the screening library showed enhanced MDM2 promoter activity and MDM2 expression in p53-deficient HCT116 cells. Among them, six clones, including NTRK2, GNA15, SFRS2, EIF5A, ELAVL1, and YWHAB mediated MAPK signaling for expressing MDM2. These results indicate that p53-independent upregulation of MDM2 by increasing selected clones may lead to oncogenesis in AML and that MDM2-modulating genes are novel potential targets for AML treatment.

  14. Isolation and characterization of DUSP11, a novel p53 target gene

    DEFF Research Database (Denmark)

    Caprara, Greta; Zamponi, Raffaella; Melixetian, Marina;

    2009-01-01

    ABSTRACT p53 regulates the expression of genes involved in cell cycle control, apoptosis and DNA damage repair. Here we demonstrate that DUSP11 (Dual Specificity Phosphatase 11), a member of the Protein Tyrosine Phosphatase family that binds to RNA-RNP complexes and RNA splicing factors, is a p53...... target gene. Consistent with this, the expression of DUSP11 is induced in a p53-dependent manner after treatment with DNA damaging agents. Chromatin immunoprecipitation analysis showed that p53 binds to 2 putative p53 DNA binding sites in the promoter region of DUSP11. Colony formation and proliferation...... (Src-Associated protein in Mitotic cells) binds to DUSP11 in vitro and in vivo. Taken together these results suggest that DUSP11 contributes to p53-dependent inhibition of cell proliferation and that it might be involved in regulating RNA splicing through SAM68....

  15. Characterization of vNr-13, the first alphaherpesvirus gene of the bcl-2 family

    International Nuclear Information System (INIS)

    The Bcl-2 family, including antiapoptotic and proapoptotic members, plays key regulating roles in programmed cell death. We report the characterization of a new member of the bcl-2 family, encoded by herpesvirus of turkeys (HVT). The product of this gene shares 80% homology with Nr-13, an apoptosis inhibitor, which is overexpressed in avian cells transformed by the v-src oncogene. This new gene, that we propose to call vnr-13, is the first member of the bcl-2 family to be isolated among α-herpesviruses. Results from cells expressing the HVT-vnr-13 gene product show that the encoded protein inhibits apoptosis and also reduces the rate of cellular proliferation. Contrary to all bcl-2 homologues found in γ-herpesvirus, which are intronless, vnr-13 has the same organization as the cellular nr-13 gene. Hence, the HVT vnr-13 gene may have been acquired from a reverse transcriptase product of an unspliced precursor RNA, or via direct recombination with the host chromosomal DNA

  16. CO-EXPRESSIONS OF SURVIVIN GENE,BCL-2 AND BAX PROTEINS IN OVARIAN CARCINOMA

    Institute of Scientific and Technical Information of China (English)

    林蓓; 张淑兰; 赵长清

    2004-01-01

    Objective To characterize the cellular properties of ovarian cancer, we examined the correlation between the expression of apoptosis-related gene survivin and those of Bcl-2 and Bar proteins. Methods Expressions of survivin mRNA, and Bcl-2 and Bax proteins in 35 cases of ovarian carcinoma, 10 cases of borderline carcinoma, 10 cases of benign tumors and 10 cases of normal tissue were evaluated by reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry SABC method, respectively. Results Expression of survivin gene was detected in a significantly greater proportion in ovarian carcinoma and borderline carcinoma than those in benign tumors and normal tissues. Although there was no relationship between expression of survivin gene and FIGO stage, histologic grade, pathological type and lymphatic metastasis, expressions of Bcl-2 and Bar proteins were positively and negatively correlated with that of survivin gene, respectively. Conclusion Survivin may play an important role in pathogenesis of ovarian carcinoma, with a synergistic role of apoptosis-related gene Bcl-2protein and an antagonistic role of Bax protein in formation and progression of ovarian carcinoma.

  17. Suppression of bcl-2 Gene by RNA Interference Increases Chemosensitivity to Cisplatin in Nasopharyngeal Carcinoma Cell Line CNE1

    Institute of Scientific and Technical Information of China (English)

    Zhi-Hua YIN; Cai-Ping REN; Feng LI; Xu-Yu YANG; Hui LI; Ming ZHAO; Kai-Tai YAO

    2004-01-01

    To explore the effect of suppressing BCL-2 expression using RNA interference (RNAi) technique in nasopharyngeal carcinoma cell line CNE1. CNE1 cell lines stably expressing shRNAs targeted bcl-2 and GL3 gene were established and gene expression inhibition was assessed by Western blotting analysis. The effect of suppressing bcl-2 by RNAi on cell growth was studied, the apoptosis induction and the sensitization of CNE 1 cells to cisplatin were quantified by MTT assay and flow cytometry. The results showed that: stable transfection of CNE 1 cells with vectors expressing shRNAs against bcl-2 decreased the expression of BCL-2 protein; suppression of BCL-2 expression did not affect cell proliferation but could increase the chemosensitivity to cisplatin in CNE1 cells. This will help physicians to make some clinical trials of gene therapy on nasopharyngeal carcinoma by RNAi.

  18. DETECTION OF p53 GENE MUTATION OF BRONCHOSCOPIC SAMPLIES IN THE PATIENTS SUSPECTED TO LUNG CANCER

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To determine the feasibility of detecting p53 gene mutations for early diagnosis of lung cancer using the samples from bronchoscopic examination. Methods: Point mutations of the exon 5-8 of p53 gene were detected in 85 bronchoscopic samples of 35 patients suspected to be lung cancer using silver staining PCR-SSCP. Results: p53 gene mutations were founded in 10 of 35 patients(28.6%). The incidence of p53 gene mutations (14.9%) was obviously higher than the cytological positive incidence(2.9%) in samples of sputum, bronchoalveolar lavage and brush, especially for the sputum(27.7%). In the bronchoscopic biopsy specimens, the incidence of p53 gene mutations (12.5%) was lower than that of pathologic positive result (50.0%). However, in view of all the bronchoscopic samples, there was no statistically difference between cytopathologic positive results (11.8%) and the incidence of p53 gene mutations (14.1%). Although the p53 mutations were most common in the samples from the patients bronchoscopically manifested as neoplasm compared with other manifestations, there was no statistical difference. It is valuable to notice that 3 patients with p53 gene mutation merely presented as bronchial inflammation in bronchoscope. Conclusion: Results indicated that the value of detecting p53 gene mutation for the diagnosis of lung cancer using the bronchoscopic samples was more superior to cytological examination and detection of p53 gene mutations in post-bronchoscopic sputum was easy and effective, may be used as a valuable method for early diagnosis of lung cancer.

  19. Frequency of p53 Gene Mutation and Protein Expression in Oral Squamous Cell Carcinoma

    International Nuclear Information System (INIS)

    Objective: To determine the frequency of p53 gene mutation and protein expression in Oral Squamous Cell Carcinoma (OSCC) and to establish correlation between the two. Study Design: Analytical study. Place and Duration of Study: Histopathology Department and Molecular Biology Laboratory, Armed Forces Institute of Pathology (AFIP), Rawalpindi, from May 2010 to May 2011. Methodology: Thirty diagnosed cases of OSCC were selected by consecutive sampling. Seventeen were retrieved from the record files of the AFIP, and 13 fresh/frozen sections were selected from patients reporting to the Oral Surgery Department, Armed Forces Institute of Dentistry (AFID). Gene p53 mutation was analyzed in all the cases using PCRSSCP analysis. DNA was extracted from the formalin-fixed and paraffin-embedded tissue sections and fresh/frozen sections. DNA thus extracted was amplified by polymerase chain reaction. The amplified products were denatured and finally analyzed by gel electrophoresis. Gene mutation was detected as electrophoretic mobility shift. The immunohistochemical marker p53 was applied to the same 30 cases and overexpression of protein p53 was recorded. Results: Immunohistochemical expression of marker p53 was positive in 67% (95% Confidence Interval (CI) 48.7 - 80.9) of the cases. Mutations of the p53 gene were detected in 23% (95% CI 11.5 - 41.2) of the OSCC. No statistically significant correlation was found between p53 gene mutation and protein p53 expression (rs = - 0.057, p = 0.765). Conclusion: A substantial number of patients have p53 gene mutation (23%) and protein p53 expression (67%) in oral squamous cell carcinoma (OSCC). (author)

  20. Mutations in the p53 gene occur in diverse human tumour types.

    Science.gov (United States)

    Nigro, J M; Baker, S J; Preisinger, A C; Jessup, J M; Hostetter, R; Cleary, K; Bigner, S H; Davidson, N; Baylin, S; Devilee, P

    1989-12-01

    The p53 gene has been a constant source of fascination since its discovery nearly a decade ago. Originally considered to be an oncogene, several convergent lines of research have indicated that the wild-type gene product actually functions as a tumour suppressor gene. For example, expression of the neoplastic phenotype is inhibited, rather than promoted, when rat cells are transfected with the murine wild-type p53 gene together with mutant p53 genes and/or other oncogenes. Moreover, in human tumours, the short arm of chromosome 17 is often deleted. In colorectal cancers, the smallest common region of deletion is centred at 17p13.1; this region harbours the p53 gene, and in two tumours examined in detail, the remaining (non-deleted) p53 alleles were found to contain mutations. This result was provocative because allelic deletion coupled with mutation of the remaining allele is a theoretical hallmark of tumour-suppressor genes. In the present report, we have attempted to determine the generality of this observation; that is, whether tumours with allelic deletions of chromosome 17p contain mutant p53 genes in the allele that is retained. Our results suggest that (1) most tumours with such allelic deletions contain p53 point mutations resulting in amino-acid substitutions, (2) such mutations are not confined to tumours with allelic deletion, but also occur in at least some tumours that have retained both parental 17p alleles, and (3) p53 gene mutations are clustered in four 'hot-spots' which exactly coincide with the four most highly conserved regions of the gene. These results suggest that p53 mutations play a role in the development of many common human malignancies.

  1. Identification of the core promoter of STK11 gene and its transcriptional regulation by p53

    Institute of Scientific and Technical Information of China (English)

    Maojin Yao; Chenjie Li; Yi Chu; Fei Wang; Xiaoliu Shi; Yongjun Wang; Hongwei Shen; Wenfeng Ning; Jianguang Tang; Xiangping Wang; Jie Li; Shiquang Zhou; Xin Yi

    2008-01-01

    Peutz-Jeghers syndrome (PJS) is an autosomal dominant disease characterized by mucocutaneous pigmentation and hamartomatous polyps. Most cases of PJS involve the inactivation of germline mutations in the serine/threonine kinase gene STK11 which is also known as LKB1. The function of STK11 was previously linked to the tumor suppressor p53 and was shown to activate the p53 target p21/ WAF1. Recently, STK11 was reported to be interacting with p53 physically in the nucleus and it can directly or indirectly phosphorylate p53. Here we characterized the 5'-flanking region of human STK11 gene and identified a 161-bp fragment with promoter activity. Sequence analysis, mutagenesis and gel shift studies revealed a binding site of Spl and p53, which affects the promoter activity. Mutation analyses showed that this fragment was required for p53-mediated transcriptional activation. This transcriptional activation was further confirmed by real-time quantitative RT-PCR and Western blot analysis. Transient transfection of p53 expression plasmid into fetal liver cell lines increased STK11 mRNA and protein levels. In conclusion, our results reveal a new role for p53 in elevating STK11 gene expression via a positive feedback pattern.

  2. P53 codon 11, 72, and 248 gene polymorphisms in endometriosis

    OpenAIRE

    Hsieh, Yao-Yuan; Lin, Chich-Sheng

    2006-01-01

    Objective: Mutated p53 gene is related to the instability of cell growth and cell cycle progression. We aimed to evaluate the association between endometriosis and p53 codon 11, 72 and 248 gene polymorphisms. Patients and methods: Women were divided into two groups: (1) moderate/severe endometriosis (n=148), and (2) non-endometriosis groups (n=150). P53 gene polymorphisms include codon11 Glu/Gln or Lys (GAG->CAG or AAG), codon 72 Arg/Pro (CGC->CCC), and codon 248 Arg/Thr (CGG->TCG). These gen...

  3. DETECTION OF p53 GENE MUTATION IN PLASMA OF PATIENTS WITH GASTRIC CANCER

    Institute of Scientific and Technical Information of China (English)

    苏鹏程; 李子禹; 张连海; 万文徽; 任晖; 张桂国; 王怡; 邓国仁; 季加孚

    2004-01-01

    Objective: To investigated p53 gene mutation in plasma of gastric cancer patients. Methods: DNA extracted from plasma and matched tumor and tumor-adjacent non-cancerous tissues of 96 gastric cancer patients, and DNA from 20 healthy volunteers were studied. Exon 5, 6, 7, and 8 of p53 were amplified by Polymerase Chain Reaction (PCR). The mutation status was analyzed by denaturing high-performance liquid chromatography (DHPLC), followed by direct sequencing of cases with aberrant chromatographic patterns. Results: Heterozygous mutations of p53 gene were detected in 19.9% (19/96) of primary tumor tissues and 5.2% (5/96) of corresponding plasma. All p53 gene mutations detected in plasma DNA consisted with mutations in the matched primary tumor samples. Neither the tumor-adjacent gastric mucosa tissues nor control plasma from healthy volunteers showed p53 gene mutation. No correlation was found between p53 mutation status and clinicopathological features of gastric cancer patients. Conclusion: p53 gene mutation in plasma can be detected in tissues and plasma of gastric cancer patients, which could be applied in screening and surveillance of this disease.

  4. Overexpression of p53 Gene in Esophageal and Cervical Cancer and the Relationship with Radiotherapy Effects

    Institute of Scientific and Technical Information of China (English)

    张晓智; 王晓丽; 李旭

    2003-01-01

    Objective:To investigate the relationship between p53 protein overexpression in esophageal and cervical squamous cell cancer and their clinical radiosensitivity. Methods: The immuno-histochemical assays were done for 52 cases with esophageal and cervical squamous cell cancer. The relationship between the assay results and short-term radiotherapy was investigated. Results: p53 overer-pression was 52.38% and 35. 48% respectively, in esophageal cancer and cervical cancer;p53 over-expression in high differentiated squamous cell cancer was knver than these in moderate and poor differentiated cases(P0. 05). In the cases of cervical cancer, p53 overexpression had the less short-term effect(P0. 05).Conclusion:This study suggests that p53 gene has the certain relationship with tumor radiosensitivity.

  5. P53 codon 11, 72, and 248 gene polymorphisms in endometriosis

    Directory of Open Access Journals (Sweden)

    Yao-Yuan Hsieh , Chich-Sheng Lin

    2006-01-01

    Full Text Available Objective: Mutated p53 gene is related to the instability of cell growth and cell cycle progression. We aimed to evaluate the association between endometriosis and p53 codon 11, 72 and 248 gene polymorphisms. Patients and methods: Women were divided into two groups: (1 moderate/severe endometriosis (n=148, and (2 non-endometriosis groups (n=150. P53 gene polymorphisms include codon11 Glu/Gln or Lys (GAG->CAG or AAG, codon 72 Arg/Pro (CGC->CCC, and codon 248 Arg/Thr (CGG->TCG. These gene polymorphisms were amplified by polymerase chain reaction and detected by electrophoresis after restriction enzyme (Taq I, BstU I, Hap II digestions. Associations between the endometriosis and p53 polymorphisms were evaluated. Results: The distributions of p53 codon 72 polymorphisms in both groups were significantly different. The proportions of Arg homozygotes/heterozygotes/Pro homozygotes in both groups were 9.5/66.2/24.3% and 30.7/50/19.3%. The proportions of Arg/Pro alleles were 42.6/57.4% and 56/44%. The distributions of p53 codon 11 and 248 polymorphisms in both groups were non-significantly different. All individuals appeared the wild genotypes (Glu11 and Arg248 homozygotes. Conclusion: Association between endometriosis and p53 codon 72 polymorphism exists. P53 codon 72*Pro-related genotype and allele are related with higher susceptibility of endometriosis. P53 codon 11 and 248 polymorphisms are not related with endometriosis susceptibility.

  6. Effect of Exercise Training on Bcl-2 and Bax Gene Expression in the Rat Heart

    OpenAIRE

    Jafari; Pourrazi; Nikookheslat; Baradaran

    2015-01-01

    Background Apoptosis or programmed cell death plays an important role in the development of cardiovascular diseases, particularly heart failure. Current evidence suggests that exercise training may alter apoptosis-related signaling in sensitive somatic tissues such as the myocardium. Objectives The aim of this study was to assess the effect of exercise training on Bcl-2 and Bax genes expression as key molecules involved in intrins...

  7. Evaluation of Bcl-2 Family Gene Expression in Hippocampus of 3, 4-methylenedioxymethamphetamine Treated Rats

    Directory of Open Access Journals (Sweden)

    Hamed Hashemi-Nasl

    2012-01-01

    Full Text Available Objective: 3,4-methylenedioxymethamphetamine (MDMA is an illicit, recreational drugthat causes cellular death and neurotoxicity. This study evaluates the effects of differentdoses of MDMA on the expression of apoptosis–related proteins and genes in the hippocampusof adult rats.Materials and Methods: In this expremental study,a total of 20 male Sprague Dawley rats(200-250 g were treated with MDMA (0, 5, 10, 20 mg/kg i.p. twice daily for 7 days. Sevendays after the last administration of MDMA, the rats were killed. Bax and Bcl-2 genesin addition to protein expressions were detected by western blot and reverse transcriptionpolymerasechain reaction (RT-PCR.Results were analyzed using one-way ANOVA andp≤0.05 was considered statistically significant.Results: Our results showed that MDMA caused dose dependent up-regulation of Baxand down-regulation of Bcl-2 in the hippocampus. There was a significant alteration inbcl-2 and bax genes density.Conclusion: Changes in apoptosis-related proteins and respective genes relating to Baxand Bcl-2 might be involved in the molecular mechanism of MDMA-induced apoptosis.

  8. Identification of partial loss of function p53 gene mutations utilizing a yeast-based functional assay

    OpenAIRE

    Kovvali, Gopala K.; Mehta, Bena; Epstein, Charles B.; Lutzker, Stuart G.

    2001-01-01

    Missense mutations within the central DNA binding region of p53 are the most prevalent mutations found in human cancer. Numerous studies indicate that ‘hot-spot’ p53 mutants (which comprise ∼30% of human p53 gene mutations) are largely devoid of transcriptional activity. However, a growing body of evidence indicates that some non-hot-spot p53 mutants retain some degree of transcriptional activity in vivo, particularly against strong p53 binding sites. We have m...

  9. The effect of Bcl-2 gene silencing on the sensitivity of cell line A549 to chemotherapeutic drugs

    Institute of Scientific and Technical Information of China (English)

    王姣琦

    2013-01-01

    Objective To investigate the effects of miRNA-mediated down-regulation of the Bcl-2gene on the chemotherapeutic sensitivities and mRNA transcriptions of sensitivity associated genes in human lung adenocarcinoma cell

  10. Effect of Exercise Training on Bcl-2 and Bax Gene Expression in the Rat Heart

    Directory of Open Access Journals (Sweden)

    Jafari

    2015-10-01

    Full Text Available Background Apoptosis or programmed cell death plays an important role in the development of cardiovascular diseases, particularly heart failure. Current evidence suggests that exercise training may alter apoptosis-related signaling in sensitive somatic tissues such as the myocardium. Objectives The aim of this study was to assess the effect of exercise training on Bcl-2 and Bax genes expression as key molecules involved in intrinsic pathway of apoptosis in the rat heart. Materials and Methods This study was conducted with a two-group experimental design (animal model and sixteen three-month-old male rats were selected and randomly divided to two groups of exercise training (n = 8 and control (n = 8. Rats in the trained group participated in an exercise training program for 12 weeks (10 – 60 m min-1, 24 – 33 min d-1, 15%. The rat hearts were removed forty-eight hours after the last training session. RNA extraction and synthesis of cDNA was done, and Bax and Bcl2 genes expression was analyzed through the Real Time-Polymerase Chain Reaction (RT-PCR. Kolmogorov-Smirnov and independent t-test were applied for statistical analysis of the data (P 0.05. However, Bcl2 expression was higher in the trained group compared to the control group (11%. Conclusions In general, it seems that three-month exercise training was effective in reducing cardiac mitochondrial pro-apoptotic protein. However, considering the results of the Bcl2 gene expression, more researches are needed to identify effects of exercise trainings on indices of myocardial apoptosis.

  11. Hereditary and acquired p53 gene mutations in childhood acute lymphoblastic leukemia.

    OpenAIRE

    Felix, C A; Nau, M M; Takahashi, T.; Mitsudomi, T.; Chiba, I.; Poplack, D G; Reaman, G H; Cole, D E; Letterio, J J; Whang-Peng, J

    1992-01-01

    The p53 gene was examined in primary lymphoblasts of 25 pediatric patients with acute lymphoblastic leukemia by the RNase protection assay and by single strand conformation polymorphism analysis in 23 of 25 cases. p53 mutations were found to occur, but at a low frequency (4 of 25). While all four mutations were identified by single strand conformation polymorphism, the comparative sensitivity of RNase protection was 50% (2 of 4). Heterozygosity was retained at mutated codons in 3 of 4 cases. ...

  12. Inactivation and inducible oncogenic mutation of p53 in gene targeted pigs.

    Directory of Open Access Journals (Sweden)

    Simon Leuchs

    Full Text Available Mutation of the tumor suppressor p53 plays a major role in human carcinogenesis. Here we describe gene-targeted porcine mesenchymal stem cells (MSCs and live pigs carrying a latent TP53(R167H mutant allele, orthologous to oncogenic human mutant TP53(R175H and mouse Trp53(R172H, that can be activated by Cre recombination. MSCs carrying the latent TP53(R167H mutant allele were analyzed in vitro. Homozygous cells were p53 deficient, and on continued culture exhibited more rapid proliferation, anchorage independent growth, and resistance to the apoptosis-inducing chemotherapeutic drug doxorubicin, all characteristic of cellular transformation. Cre mediated recombination activated the latent TP53(R167H allele as predicted, and in homozygous cells expressed mutant p53-R167H protein at a level ten-fold greater than wild-type MSCs, consistent with the elevated levels found in human cancer cells. Gene targeted MSCs were used for nuclear transfer and fifteen viable piglets were produced carrying the latent TP53(R167H mutant allele in heterozygous form. These animals will allow study of p53 deficiency and expression of mutant p53-R167H to model human germline, or spontaneous somatic p53 mutation. This work represents the first inactivation and mutation of the gatekeeper tumor suppressor gene TP53 in a non-rodent mammal.

  13. Is p53 gene mutation an indicatior of the biological behaviors of recurrence of hepatocellular carcinoma?

    Institute of Scientific and Technical Information of China (English)

    I-Shyan Sheen; Kuo-Shyang Jeng; Ju-Yann Wu

    2003-01-01

    AIM: To evaluate mutant p53 gene in primary hepatocellular carcinoma and to investigate the correlation between it and the recurrence of hepatocellular carcinoma.METHODS: Mutations of p53 gene were examined using antihuman p53 monoclonal antibody and immunohistochemical staining in 79 resected hepatocellular carcinomas. The correlations among variables of p53 positivity and invasiveness, disease free interval and survival were studied.In addition, in those who developed recurrence, the correlation among p53 positivity, clinical features and postrecurrence survival were also studied.RESULTS: Of these 79 cases, 64 (81%) had p53 mutation.Those patients with mutant p53 positivityhad significantly more tumor recurrence (76.6 % vs 40.0 %, P=0.0107).However, the COX proportional hazards model showed that p53 overexpression had only weak correlations with recurrence free interval and survival time (P=0.088 and 0.081), which was probably related to the short duration of follow-up. The invasiveness variables may be predictors of HCC recurrence. On univariate analysis, more patients with mutant p53 positivity had vascular permeation [78.1vs 40.0 %, P=0.0088, O.R. (odds ratio) =5.3], grade Ⅱ-ⅣV differentiation (98.4 vs 80.0 %, P=0.0203, O.R. =15.7), no complete capsule (82.8 vs 53.3 %, P=0.0346, O.R. =4.2)and daughter nodules (60.9 vs. 33.3 %, P=0.0527, O.R.=3.1) than patients with negative p53 staining. Onmultivariate analysis, only vascular permeation and grade of differentiation remained significant (P=0.042 and 0.012).There was no statistically significant correlation betweenthe status of p53 in the primary lesion and the clinical features of recurrent hepatocellular carcinomas examined,including extrahepatic metastasis (P=0.1103) and the number of recurrent tumors (P= 1.000) except for diseaseover more than one segment in the extent of recurrent tumors (P=0.0043). The post-recurrence median survival was lower in patients in whom p53 mutation had been detected in the

  14. Sundew plant, a potential source of anti-inflammatory agents, selectively induces G2/M arrest and apoptosis in MCF-7 cells through upregulation of p53 and Bax/Bcl-2 ratio.

    Science.gov (United States)

    Ghate, N B; Das, A; Chaudhuri, D; Panja, S; Mandal, N

    2016-01-01

    The worldwide cancer incidences are remarkable despite the advancement in cancer drug discovery field, highlighting the need for new therapies focusing on cancer cell and its microenvironment, including inflammation. Several species of Drosera (family: Droseraceae) are used in various traditional as well as homeopathic systems of medicine. Drosera burmannii Vahl. is also enlisted in French Pharmacopoeia in 1965 for the treatment of inflammatory diseases, including chronic bronchitis, asthma and whooping cough. The present study is designed to substantiate the potential of D. burmannii in in vitro anticancer activity and its relation with anti-inflammatory property. In vitro anticancer study revealed that DBME is inhibiting the proliferation of MCF-7 cells without affecting the viability of other malignant and non-malignant cells. DBME induced G2/M phase arrest and apoptosis in MCF-7 cells by suppressing the expression of cyclin A1, cyclin B1 and Cdk-1 and increasing the expression of p53, Bax/Bcl-2 ratio leading to activation of caspases and PARP degradation. Presence of caspase-8 (Z-IETD-fmk) and caspase-9 (Z-LEHD-fmk) inhibitors alone did prevent the apoptosis partially while apoptosis prevention was significantly observed when used in combination, suggesting vital role of caspases in DBME-induced apoptosis in MCF-7 cells. DBME also downregulated LPS-induced increased expression of iNOS, COX-2 and TNF-α along with suppression on intracellular ROS production that confirms the potential of DBME as anti-inflammatory extract. GCMS analysis revealed the presence of four major compounds hexadecanoic acid, tetradecanoic acid, hexadecen-1-ol, trans-9 and 1-tetradecanol along with some other fatty acid derivatives and carotenoids (Beta-doradecin) in DBME. These findings confirmed the anti-inflammatory activity of DBME, which is already listed in French Pharmacopeia in 1965. Here we have additionally reported the anti-breast cancer activity of DBME and its relation to the

  15. Sundew plant, a potential source of anti-inflammatory agents, selectively induces G2/M arrest and apoptosis in MCF-7 cells through upregulation of p53 and Bax/Bcl-2 ratio

    Science.gov (United States)

    Ghate, NB; Das, A; Chaudhuri, D; Panja, S; Mandal, N

    2016-01-01

    The worldwide cancer incidences are remarkable despite the advancement in cancer drug discovery field, highlighting the need for new therapies focusing on cancer cell and its microenvironment, including inflammation. Several species of Drosera (family: Droseraceae) are used in various traditional as well as homeopathic systems of medicine. Drosera burmannii Vahl. is also enlisted in French Pharmacopoeia in 1965 for the treatment of inflammatory diseases, including chronic bronchitis, asthma and whooping cough. The present study is designed to substantiate the potential of D. burmannii in in vitro anticancer activity and its relation with anti-inflammatory property. In vitro anticancer study revealed that DBME is inhibiting the proliferation of MCF-7 cells without affecting the viability of other malignant and non-malignant cells. DBME induced G2/M phase arrest and apoptosis in MCF-7 cells by suppressing the expression of cyclin A1, cyclin B1 and Cdk-1 and increasing the expression of p53, Bax/Bcl-2 ratio leading to activation of caspases and PARP degradation. Presence of caspase-8 (Z-IETD-fmk) and caspase-9 (Z-LEHD-fmk) inhibitors alone did prevent the apoptosis partially while apoptosis prevention was significantly observed when used in combination, suggesting vital role of caspases in DBME-induced apoptosis in MCF-7 cells. DBME also downregulated LPS-induced increased expression of iNOS, COX-2 and TNF-α along with suppression on intracellular ROS production that confirms the potential of DBME as anti-inflammatory extract. GCMS analysis revealed the presence of four major compounds hexadecanoic acid, tetradecanoic acid, hexadecen-1-ol, trans-9 and 1-tetradecanol along with some other fatty acid derivatives and carotenoids (Beta-doradecin) in DBME. These findings confirmed the anti-inflammatory activity of DBME, which is already listed in French Pharmacopeia in 1965. Here we have additionally reported the anti-breast cancer activity of DBME and its relation to the

  16. Combined expression of gastrointestinal hormone SP and anti-apoptosis geneBcl-2 in gastric carcinoma

    Institute of Scientific and Technical Information of China (English)

    Yan Ling Feng; Qin Xian Zhang; Sheng Lei Li

    2000-01-01

    AIM To study the combined expression of gastrointestinal hormone substance P and anti-apoptosis gene Bcl-2 in gastric carcinoma and its significance.METHODS Substance P and Bcl-2 protein expression was examined by the S-P immunohistochemicalmethod in 33 cases of gastric carcinoma, 17 adjacent the carcinoma and 13 normal gastric mucoma.RESULTS Positive expression of SP in gastric carcinoma was higher than that of both adjacent and normalmucosa (P 0.05). The expression of bcl-2 both in gastric carcinoma and adjacent tissues werehigher than that of normal gastric mucosa (P< 0.05-0.01). But the positive expression of Bcl-2 had nostatistical significance between gastric carcinoma and adjacent tissues.CONCLUSION Both gastrointestinal hormone SP and Bcl-2 gene have synergistic expression in gastriccarcinoma, indicating that they all take part in the occurrence of gastric carcinoma. Abnormal expression ofBcl-2 gene occurred in benign gastric pathological changes, once they become carcinoma, the positiveexpression of cell is no more increased, possibly because that there is no more increase of the intensity of Bcl-2 inhibition of cell apoptosis.

  17. Curcumin significantly enhances dual PI3K/Akt and mTOR inhibitor NVP-BEZ235-induced apoptosis in human renal carcinoma Caki cells through down-regulation of p53-dependent Bcl-2 expression and inhibition of Mcl-1 protein stability.

    Directory of Open Access Journals (Sweden)

    Bo Ram Seo

    Full Text Available The PI3K/Akt and mTOR signaling pathways are important for cell survival and growth, and they are highly activated in cancer cells compared with normal cells. Therefore, these signaling pathways are targets for inducing cancer cell death. The dual PI3K/Akt and mTOR inhibitor NVP-BEZ235 completely inhibited both signaling pathways. However, NVP-BEZ235 had no effect on cell death in human renal carcinoma Caki cells. We tested whether combined treatment with natural compounds and NVP-BEZ235 could induce cell death. Among several chemopreventive agents, curcumin, a natural biologically active compound that is extracted from the rhizomes of Curcuma species, markedly induced apoptosis in NVP-BEZ235-treated cells. Co-treatment with curcumin and NVP-BEZ235 led to the down-regulation of Mcl-1 protein expression but not mRNA expression. Ectopic expression of Mcl-1 completely inhibited curcumin plus NVP-NEZ235-induced apoptosis. Furthermore, the down-regulation of Bcl-2 was involved in curcumin plus NVP-BEZ235-induced apoptosis. Curcumin or NVP-BEZ235 alone did not change Bcl-2 mRNA or protein expression, but co-treatment reduced Bcl-2 mRNA and protein expression. Combined treatment with NVP-BEZ235 and curcumin reduced Bcl-2 expression in wild-type p53 HCT116 human colon carcinoma cells but not p53-null HCT116 cells. Moreover, Bcl-2 expression was completely reversed by treatment with pifithrin-α, a p53-specific inhibitor. Ectopic expression of Bcl-2 also inhibited apoptosis in NVP-BE235 plus curcumin-treated cells. In contrast, NVP-BEZ235 combined with curcumin did not have a synergistic effect on normal human skin fibroblasts and normal human mesangial cells. Taken together, combined treatment with NVP-BEZ235 and curcumin induces apoptosis through p53-dependent Bcl-2 mRNA down-regulation at the transcriptional level and Mcl-1 protein down-regulation at the post-transcriptional level.

  18. [Dexamethasone affect on the expression of bcl-2 and mTOR genes in T-lymphocytes from healthy donors].

    Science.gov (United States)

    Fatkhullina, A R; Abramov, S N; Skibo, Iu V; Abramova, Z I

    2014-01-01

    Synthetic glucocorticoids are able to activate apoptosis in the cells by regulating the transcription of the respective genes. Effect of dexamethasone on apoptosis is an established fact. However, its influence on another program of cell death autophagy, is currently unproven. Therefore, in this paper we have analyzed the influence of dexamethasone on the expression of bcl-2 and mTOR genes in T-lymphocytes from healthy donors. The results showed that dexamethasone reduced the expression of bcl-2 and mTOR genes. However, the nature of the effect of dexamethasone on mTOR and bcl-2 expression was different: the expression of bcl-2 gene in the long-term cultivation was maintained at the same reduced level, while the expression of mTOR was first reduced and then increased.

  19. Gene Expression Profiling Identifies Important Genes Affected by R2 Compound Disrupting FAK and P53 Complex

    Energy Technology Data Exchange (ETDEWEB)

    Golubovskaya, Vita M., E-mail: Vita.Golubovskaya@roswellpark.org; Ho, Baotran [Department of Surgical Oncology, Roswell Park Cancer Institute, Buffalo, NY 14263 (United States); Conroy, Jeffrey [Genomics Shared Resource, Center for Personalized Medicine, Roswell Park Cancer Institute, Buffalo, NY 14263 (United States); Liu, Song; Wang, Dan [Bioinformatics Core Facility, Biostatistics, Roswell Park Cancer Institute, Buffalo, NY 14263 (United States); Cance, William G. [Department of Surgical Oncology, Roswell Park Cancer Institute, Buffalo, NY 14263 (United States)

    2014-01-21

    Focal Adhesion Kinase (FAK) is a non-receptor kinase that plays an important role in many cellular processes: adhesion, proliferation, invasion, angiogenesis, metastasis and survival. Recently, we have shown that Roslin 2 or R2 (1-benzyl-15,3,5,7-tetraazatricyclo[3.3.1.1~3,7~]decane) compound disrupts FAK and p53 proteins, activates p53 transcriptional activity, and blocks tumor growth. In this report we performed a microarray gene expression analysis of R2-treated HCT116 p53{sup +/+} and p53{sup −/−} cells and detected 1484 genes that were significantly up- or down-regulated (p < 0.05) in HCT116 p53{sup +/+} cells but not in p53{sup −/−} cells. Among up-regulated genes in HCT p53{sup +/+} cells we detected critical p53 targets: Mdm-2, Noxa-1, and RIP1. Among down-regulated genes, Met, PLK2, KIF14, BIRC2 and other genes were identified. In addition, a combination of R2 compound with M13 compound that disrupts FAK and Mmd-2 complex or R2 and Nutlin-1 that disrupts Mdm-2 and p53 decreased clonogenicity of HCT116 p53{sup +/+} colon cancer cells more significantly than each agent alone in a p53-dependent manner. Thus, the report detects gene expression profile in response to R2 treatment and demonstrates that the combination of drugs targeting FAK, Mdm-2, and p53 can be a novel therapy approach.

  20. Clofarabine Has Apoptotic Effect on T47D Breast Cancer Cell Line via P53R2 Gene Expression

    OpenAIRE

    Mohammad Rahmati-Yamchi; Nosratollah Zarghami; Hojjatollah Nozad Charoudeh; Yasin Ahmadi; Behzad Baradaran; Mohammad Khalaj-Kondori; Morteza Milani; Abolfazl Akbarzadeh; Maghsud Shaker; Mohammad Pourhassan-Moghaddam

    2015-01-01

    Purpose: Clofarabine, a purine nucleoside analogue and inhibitor of Ribonucleotide Reductase (RR), is used for treatment of leukemia. Clofarabine-induced defect in DNA replication, induces p53 and subsequently P53R2 genes as subunit of RR. clofarabine deregulated P53R2 gene expression leading to the elevated levels of P53R2 which impose resistance to DNA damaging drugs. In this study the apoptotic and cytotoxic effects of clofarabine has been investigated on breast cancer ce...

  1. DDMC-p53 gene therapy with or without cisplatin and microwave ablation

    Directory of Open Access Journals (Sweden)

    Hohenforst-Schmidt W

    2015-05-01

    delivered was 0.5 mL. Increased toxicity was observed in the group receiving DDMC-p53 plus cisplatin plus microwave followed by the group receiving DDMC-p53 plus cisplatin. Infection after repeated treatment administration was a major issue. We conclude that a combination of gene therapy using DDMC-p53 with or without cisplatin and microwave is an alternative method for local disease control. However, more experiments are required in a larger model to identify the appropriate dosage profile.Keywords: DDMC, p53, carboplatin, microwave, non-small cell lung cancer

  2. Bcl-2 GENE REARRANGEMENT DETERMINED BY PCR AS A MEAN TO DETECT MINIMAL RESIDUAL DISEASE IN MALIGNANT LYMPHOMAS

    Institute of Scientific and Technical Information of China (English)

    XIANG Zhi-fu; LU Yu-ying; LAI Yong-rong; CHEN Yan; LI Hui-yu; ZOU Ping

    1999-01-01

    Objective: To develop a sensitive method to detect minimal residual disease and to elucidate the significance of bcl-2 gene rearrangement in diagnosis and treatment of malignant lymphoma. Methods: Using polymerase chain reaction (PCR) to detect bcl-2 gene rearrangement and using serial dilution method to define the sensitivity of PCR. Results: In 9 different malignant lymphoma cell lines, Su-DHL-4 and Su-DHL-6 were shown bcl-2(MBR)/JH rearrangement, the sensitivity of PCR was 1:105. In 16 patients with follicular lymphoma, the peripheral blood and bone marrow were PCR positive in 4 cases both at initial diagnosis and after complete remission. Conclusion:Detection of bcl-2 gene rearrangement by PCR provides a sensitive and specific assay of minimal residual disease.It is helpful to improve staging of disease, prognosis and evaluation of the treatment results.

  3. dNTP Supply Gene Expression Patterns after P53 Loss

    Energy Technology Data Exchange (ETDEWEB)

    Radivoyevitch, Tomas, E-mail: txr24@case.edu [Departments of Epidemiology and Biostatistics, General Medical Sciences (Oncology), and Pathology, Case Western Reserve School of Medicine, Cleveland, OH 44106 (United States); Saunthararajah, Yogen [Department of Translational Hematology & Oncology Research, Taussig Cancer Institute, Cleveland Clinic, 9500 Euclid Ave. R40, Cleveland, OH 44195 (United States); Pink, John [Departments of Epidemiology and Biostatistics, General Medical Sciences (Oncology), and Pathology, Case Western Reserve School of Medicine, Cleveland, OH 44106 (United States); Ferris, Gina [Department of Radiation Oncology, University Hospitals Case Medical Center and Case Western Reserve School of Medicine, Cleveland, OH 44106 (United States); Lent, Ian; Jackson, Mark; Junk, Damian [Departments of Epidemiology and Biostatistics, General Medical Sciences (Oncology), and Pathology, Case Western Reserve School of Medicine, Cleveland, OH 44106 (United States); Kunos, Charles A. [Department of Radiation Oncology, University Hospitals Case Medical Center and Case Western Reserve School of Medicine, Cleveland, OH 44106 (United States)

    2012-11-20

    Loss of the transcription factor p53 implies mRNA losses of target genes such as the p53R2 subunit of human ribonucleotide reductase (RNR). We hypothesized that other genes in the dNTP supply system would compensate for such p53R2 losses and looked for this in our own data and in data of the Gene Expression Omnibus (GEO). We found that the de novo dNTP supply system compensates for p53R2 losses with increases in RNR subunit R1, R2, or both. We also found compensatory increases in cytosolic deoxycytidine kinase (dCK) and thymidine kinase 1 (TK1) and in mitochondrial deoxyguanosine kinase (dGK), all of the salvage dNTP supply system; in contrast, the remaining mitochondrial salvage enzyme thymidine kinase 2 (TK2) decreased with p53 loss. Thus, TK2 may be more dedicated to meeting mitochondrial dNTP demands than dGK which may be more obligated to assist cytosolic dNTP supply in meeting nuclear DNA dNTP demands.

  4. Minocycline mechanism of neuroprotection involves the Bcl-2 gene family in optic nerve transection.

    Science.gov (United States)

    Levkovitch-Verbin, Hani; Waserzoog, Yael; Vander, Shelly; Makarovsky, Daria; Ilia, Piven

    2014-10-01

    The second-generation tetracycline, minocycline, has been shown to exhibit neuroprotective therapeutic benefits in many neurodegenerative diseases including experimental glaucoma and optic nerve transection (ONT). This study investigated the mechanism underlying minocycline neuroprotection in a model of ONT. ONT was applied unilaterally in 36 Wistar rat eyes. The rats were randomly divided into a minocycline (22 mg/kg/d) treatment group and a saline treatment group (control). Treatment (minocycline or saline) was given by intraperitoneal injections initiated 3 d before ONT and continued daily until the end of the experiment. The involvement of pro-apoptotic, pro-survival and inflammatory pathways was analyzed by quantitative Real-Time Polymerase Chain Reaction at 4 h and 3 d after the transection in both treatment groups. The involvement of Bcl-2 protein was evaluated by immunohistochemistry. We found that Minocycline significantly increased the expression of the antiapoptotic gene bcl-2 4 h after transection (n = 8, p = 0.008) and decreased the expression of Bax at the same time point (n = 8, p = 0.03). Tumor Necrosis Factor α (TNFα), Inhibitor of Apoptosis Protein (IAP1) and Gadd45α were significantly upregulated in the retinas of eyes with ONTs compared to control (n = 10 for each gene, p = 0.02, p = 0.03, p = 0.04, respectively) but this effect was unaffected by minocycline. This study further support that the mechanism underlying minocycline neuroprotection involves the Bcl-2 gene family, suggesting that minocycline has antiapoptotic properties that support its value as a promising neuroprotective drug. PMID:24410139

  5. Clinical utility of recombinant adenoviral human p53 gene therapy: current perspectives

    Directory of Open Access Journals (Sweden)

    Chen GX

    2014-10-01

    Full Text Available Guang-xia Chen,1,* Shu Zhang,2–4,* Xiao-hua He,1 Shi-yu Liu,1 Chao Ma,2–4 Xiao-Ping Zou2–4 1Department of Gastroenterology, First People’s Hospital of Xuzhou, Xuzhou, Jiangsu Province, People’s Republic of China; 2Department of Gastroenterology, Drum Tower Hospital, 3Medical School of Nanjing University, 4Jiangsu Clinical Medical Center of Digestive Disease, Nanjing, People’s Republic of China *These authors have contributed equally to the paperAbstract: Gene therapy has promised to be a highly effective antitumor treatment by introducing a tumor suppressor gene or the abrogation of an oncogene. Among the potential therapeutic transgenes, the tumor suppressor gene p53 serves as an attractive target. Restoration of wild-type p53 function in tumors can be achieved by introduction of an intact complementary deoxyribonucleic acid copy of the p53 gene using a suitable viral vector, in most cases an adenoviral vector (Adp53. Preclinical in vitro and in vivo studies have shown that Adp53 triggers a dramatic tumor regression response in various cancers. These viruses are engineered to lack certain early proteins and are thus replication defective, including Gendicine, SCH-58500, and Advexin. Several types of tumor-specific p53-expressing conditionally replicating adenovirus vectors (known as replication-competent CRAdp53 vectors have been developed, such as ONYX 015, AdDelta24-p53, SG600-p53, OBP-702, and H101. Various clinical trials have been conducted to investigate the safety and efficiency of these adenoviral vectors. In this review we will talk about the biological mechanisms, clinical utility, and therapeutic potentials of the replication-deficient Adp53-based and replication-competent CRAdp53-based gene therapy.Keywords: adenovirus, Adp53, CRAdp53

  6. Utility of adenovirus-mediated Fas ligand and bcl-2 gene transfer to modulate rat liver allograft survival

    Institute of Scientific and Technical Information of China (English)

    De-Sheng Wang; Yu Li; Ke-Feng Dou; Kai-Zong Li; Zhen-Shun Song

    2006-01-01

    BACKGROUND: Expression of Fas ligand (FasL) on the graft by gene transduction is expected to introduce apoptosis to lymphocytes to protect rejection, but the FasL-expressing graft cells may also induce apoptosis as the graft usually expresses Fas antigens. In this study, a strong antiapoptotic gene, bcl-2, was cotransfected with the FasL gene in rat liver graft to protect against Fas-mediated cell death and to prolong recipient survival. METHODS: Orthotopic liver transplantation was done in a strain combination of DA to LEW rats. After donor vascular isolation, adenovirus-mediated FasL and bcl-2 genes were cotransfected in the liver graft. RESULTS: Intragraft expression of FasL mRNA was constitutively expressed after adenovirus-mediated transduction, although expression of FasL increased mildly in control grafts. Bcl-2 mRNA was highly expressed at 2 days after reperfusion. In contrast, lower expression of bcl-2 was observed in the control group. The average survival of the gene transferred allografts increased from (9.8+1.3) days to (18.5+8.7) days compared with the control group. CONCLUSION: Our results indicate that rat liver allografts can be protected against host immune responses by adenovirus-mediated FasL and bcl-2 transfection, and that bcl-2 expression prevents the graft from Fas-mediated apoptosis.

  7. Depression of p53-independent Akt survival signals in human oral cancer cells bearing mutated p53 gene after exposure to high-LET radiation

    International Nuclear Information System (INIS)

    Highlights: ► High-LET radiation induces efficiently apoptosis regardless of p53 gene status. ► We examined whether high-LET radiation depresses the Akt-survival signals. ► High-LET radiation depresses of survival signals even in the mp53 cancer cells. ► High-LET radiation activates Caspase-9 through depression of survival signals. ► High-LET radiation suppresses cell growth through depression of survival signals. -- Abstract: Although mutations and deletions in the p53 tumor suppressor gene lead to resistance to low linear energy transfer (LET) radiation, high-LET radiation efficiently induces cell lethality and apoptosis regardless of the p53 gene status in cancer cells. Recently, it has been suggested that the induction of p53-independent apoptosis takes place through the activation of Caspase-9 which results in the cleavage of Caspase-3 and poly (ADP-ribose) polymerase (PARP). This study was designed to examine if high-LET radiation depresses serine/threonine protein kinase B (PKB, also known as Akt) and Akt-related proteins. Human gingival cancer cells (Ca9–22 cells) harboring a mutated p53 (mp53) gene were irradiated with 2 Gy of X-rays or Fe-ion beams. The cellular contents of Akt-related proteins participating in cell survival signaling were analyzed with Western Blotting 1, 2, 3 and 6 h after irradiation. Cell cycle distributions after irradiation were assayed with flow cytometric analysis. Akt-related protein levels decreased when cells were irradiated with high-LET radiation. High-LET radiation increased G2/M phase arrests and suppressed the progression of the cell cycle much more efficiently when compared to low-LET radiation. These results suggest that high-LET radiation enhances apoptosis through the activation of Caspase-3 and Caspase-9, and suppresses cell growth by suppressing Akt-related signaling, even in mp53 bearing cancer cells.

  8. Detecting the polymorphism sites of p53 and Fas genes of Han population in Zhejiang province

    Institute of Scientific and Technical Information of China (English)

    Yang Zhuo; Xingye Zeng; Dadao Huang; Xuexue Zhou

    2006-01-01

    BACKGROUND: It is of significance for single nucleotide polymorphisms (SNPs),a difference of rank, which exists widely in biology, genetics and other fields.OBJECTIVE: To detect polymorphism sites in exon-4 of p53 gene, promotor of Fas gene and intron-7 of Fas gene of healthy people in Han nationality in Zhejiang province.DESIGN: Simple random sampling.SETTING: Department of Surgery of the 118 Hospital of Chinese PLA.PARTICIPANTS: A total of 80 healthy people in Han nationality were selected from hospitals in Zhejiang province from August 2005 to January 2006. There were 43 males and 37 females aged from 3 to 78 years with the mean age of 39.5 years, and all subjects were consent. DNA which was used in genetic analysis was selected from peripheral venous blood of all subjects and maintained at -20 ℃.METHODS: Polymorphism sites in exon-4 of p53 gene, promotor of Fas gene and intron-7 of Fas gene were detected with directly DNA sequencing technique.MAIN OUTCOME MEASURES: Polymorphism sites in exon-4 of p53 gene, promotor of Fas gene and intron-7 of Fas gene of healthy people in Han nationality in Zhejiang province.RESULTS: A total of 80 samples were involved in the final analysis. SNPs sites were found at the 119th base of exon-4 of p53 gene (the 72nd codon of p53 gene), the 670th base of upper start codon in promotor of Fas gene (Fas-670), and the 995th base of intron-7 of Fas gene, especially SNPs in the 995th base of intron-7 pf Fas gene, I.e. C→A transversion, was a new site.CONCLUSION: One unknown SNPs site is discovered in intron-7 of Fas gene of people in Han nationality in Zhejiang province. This study also proves that the 72nd codon exists in p53 gene and the -670 polymorphism site exists in promotor of Fas gene.

  9. SPATA18, a Spermatogenesis-Associated Gene, Is a Novel Transcriptional Target of p53 and p63▿

    OpenAIRE

    Bornstein, Chamutal; Brosh, Ran; Molchadsky, Alina; Madar, Shalom; Kogan-Sakin, Ira; Goldstein, Ido; Chakravarti, Deepavali; Flores, Elsa R.; Goldfinger, Naomi; Sarig, Rachel; Rotter, Varda

    2011-01-01

    The transcription factor p53 functions not only to suppress tumorigenesis but also to maintain normal development and homeostasis. Although p53 was implicated in different aspects of fertility, including spermatogenesis and implantation, the mechanism underlying p53 involvement in spermatogenesis is poorly resolved. In this study we describe the identification of a spermatogenesis-associated gene, SPATA18, as a novel p53 transcriptional target and show that SPATA18 transcription is induced by...

  10. Expression and significance of Bcl-2 gene and Bax gene in lung cancer%凋亡相关基因bcl-2和bax在肺癌中的表达及意义

    Institute of Scientific and Technical Information of China (English)

    郭雷; 王福昌; 杨五计

    2001-01-01

    To study the relationship between expression of bcl-2 and baxgene and lung cancer.The bcl-2 and bax gene expression in 51 lung cancer tissues and tissues near cancer were deteeted by immunohistochemical SP method.The positive degree of bcl-2 gene expression in lung cancer was higher than that in tissues near cancer.The positive degree of bax gene expression in lung cancer was lower than that in tissues near cancer.Both differences were very significant(P<0.01).There was no correlations between the immunoreactivity of bcl-2 and bax gene and histology,gender,smoking history,clinical subtypes,stage and lymphatic metastasis(P>0.05).It suggests that bcl-2 and bax gene may play an important role in tumorgenesis and tumor development.The detection and determination of bcl-2 and bax gene in preinvasive lesions may contribute to the early diagnosis of lung cancer.Some drugs can down-regulate bcl-2 expression and speed apoptosis so as to improve the sensitivity to chemical therapy and radiation.%为探讨B细胞淋巴瘤/白血病-2(bcl-2)基因及其同源类似物bax基因的表达与肺癌发生的关系,应用免疫组化SP法检测了51例肺癌患者的肺癌标本及其癌旁组织中bcl-2、bax的表达。结果显示,bcl-2在肺癌中染色比在癌旁组织中深,bax在肺癌中染色比在癌旁组织中浅,两者之间均有极显著差异(P<0.01);bcl-2、bax表达与肺癌的组织分型、患者的性别、吸烟史、临床分型、分期及淋巴结转移无关(P>0.05)。提示:①bcl-2、bax在肺癌发生中具有重要作用。②在癌前病变组织中检测并比较bcl-2和bax的表达,有利于肺癌的早期诊断。③可通过药物使bcl-2表达降低,促进凋亡,提高患者对放、化疗的敏感性。

  11. Carbon nanoparticle induced cytotoxicity in human mesenchymal stem cells through upregulation of TNF3, NFKBIA and BCL2L1 genes.

    Science.gov (United States)

    Periasamy, Vaiyapuri S; Athinarayanan, Jegan; Alfawaz, Mohammed A; Alshatwi, Ali A

    2016-02-01

    Carbon based nanomaterials, including carbon nanotubes, graphene, nanodiamond and carbon nanoparticles, have emerged as potential candidates for a wide variety of applications because of their unusual electrical, mechanical, thermal and optical properties. However, our understanding of how increased usage of carbon based nanomaterials could lead to harmful effects in humans and other biological systems is inadequate. Our present investigation is focused on the cellular toxicity of carbon nanoparticles (CNPs) on human mesenchymal stem cells (hMSCs). Following exposure to CNPs, cell viability, nuclear morphological changes, apoptosis and cell cycle progression were monitored. Furthermore, the expression of genes involved in both cell death (e.g., P53, TNF3, CDKN1A, TNFRSF1A, TNFSF10, NFKBIA, BCL2L1) and cell cycle regulation (e.g., PCNA, EGR1, E2F1, CCNG1, CCND1, CCNC, CYCD3) were assessed using qPCR. Our results indicated that CNPs reduce cell viability and cause chromatin condensation and DNA fragmentation. Cell cycle analysis indicated that CNPs affect the cell cycle progression. However, the gene expression measurements confirmed that CNPs significantly upregulated the P53, TNF3, CDKNIA, and NFKBIA genes and downregulated the EGR1 gene in hMSCs. Our findings suggest that CNPs reduce cell viability by disrupting the expression of cell death genes in human mesenchymal stem cell (hMSC). The results of this investigation revealed that CNPs exhibited moderate toxicity on hMSCs.

  12. MUTATION OF p53 GENE IN TRANSFORMED RAT TRACHEAL EPITHELIAL CELLS INDUCED BY RADIATION

    Institute of Scientific and Technical Information of China (English)

    赵永良; 吴德昌; 刘国廉; 项晓琼

    1998-01-01

    The highly conserved domain (exon 5-8) of p53 gene in transformed rat tracheal epithelial (RTE) cells was analyzed by means of polymerase chain reaction and single strand conformation polymorphism (PCR-SSCP). The result showed that single strand of exon 8 gene had mobility shift in polyacrylamide nondenaturing gel. DNA sequencing proved the mutation was G→C transversion at condon 265.

  13. The association of apoptotic protein expressions sensitive to apoptosis gene, p73 and p53 with the prognosis of cervical carcinoma

    Directory of Open Access Journals (Sweden)

    Mega Tiber P

    2014-11-01

    Full Text Available Pinar Mega Tiber,1 Latife Baloglu,2 Sevgi Ozden,3 Zerrin Ozgen,4 Hazan Ozyurt,3 Makbule Eren,3 Oya Orun11Department of Biophysics, Marmara University, School of Medicine, Maltepe, Istanbul, Turkey; 2Laboratory Medicine, Karolinska Institute Biomedical Laboratory Science, Stockholm, Sweden; 3Clinic of Radiation Oncology, Dr Lutfi Kirdar Kartal Education and Research Hospital, Istanbul, Turkey; 4Department of Radiation Oncology, Marmara University, School of Medicine, Kaynarca, Istanbul, TurkeyObjective: To evaluate the expressions of several apoptotic pathway proteins in relation to clinical parameters and survival in patients with cervical carcinoma.Methods: A total of 20 patients with clinically advanced staged carcinoma of cervix (International Federation of Gynecology and Obstetrics [FIGO] stage IIB-IVA aged from 40 to 75 years were included in this study. The expression profile of anti-apoptotic protein (sensitive to apoptosis gene [SAG], mitochondrial apoptotic proteins (B-cell lymphoma-extra-large [Bcl-xL] and Bcl-2 homologous antagonist/killer [Bak], and tumor suppressor proteins (p73 and p53 were examined by real-time polymerase chain reaction experiments along with their relation to clinical parameters and survival analyses during follow-up for 5 to 8 years.Results: No significant difference was found in the expressions of SAG, Bcl-xL, Bak, p73 and p53 proteins with respect to stage and grade of tumor. A significant positive correlation was noted between SAG and Bcl-xL genes (r=0.752, P<0.001 and between SAG and Bak genes (r=0.589, P=0.006. Among genes determined to be significantly associated with overall survival in the univariate analysis (P=0.026 for SAG, P=0.002 for Bcl-xL, and P=0.027 for p53, only p53 was identified as the significant predictor in the multivariate analysis (hazard ratio: 8.53, 95% confidence interval: 1.34–54.2, P=0.023.Conclusion: In conclusion, our findings demonstrated a reverse correlation of SAG, Bcl

  14. The p53-p21-DREAM-CDE/CHR pathway regulates G2/M cell cycle genes.

    Science.gov (United States)

    Fischer, Martin; Quaas, Marianne; Steiner, Lydia; Engeland, Kurt

    2016-01-01

    The tumor suppressor p53 functions predominantly as a transcription factor by activating and downregulating gene expression, leading to cell cycle arrest or apoptosis. p53 was shown to indirectly repress transcription of the CCNB2, KIF23 and PLK4 cell cycle genes through the recently discovered p53-p21-DREAM-CDE/CHR pathway. However, it remained unclear whether this pathway is commonly used. Here, we identify genes regulated by p53 through this pathway in a genome-wide computational approach. The bioinformatic analysis is based on genome-wide DREAM complex binding data, p53-depedent mRNA expression data and a genome-wide definition of phylogenetically conserved CHR promoter elements. We find 210 target genes that are expected to be regulated by the p53-p21-DREAM-CDE/CHR pathway. The target gene list was verified by detailed analysis of p53-dependent repression of the cell cycle genes B-MYB (MYBL2), BUB1, CCNA2, CCNB1, CHEK2, MELK, POLD1, RAD18 and RAD54L. Most of the 210 target genes are essential regulators of G2 phase and mitosis. Thus, downregulation of these genes through the p53-p21-DREAM-CDE/CHR pathway appears to be a principal mechanism for G2/M cell cycle arrest by p53.

  15. From Sea Anemone to Homo Sapiens: The Evolution of the p53 Family of Genes

    Energy Technology Data Exchange (ETDEWEB)

    Levine, Arnold (Institute for Advanced Study)

    2009-09-14

    The human genome contains three transcription factors termed p53, p63 and p73 which are related orthologues. The function of the p53 protein is to respond to a wide variety of stresses which can disrupt the fidelity of DNA replication and cell division in somatic cells of the body. These stress signals, such as DNA damage, increase the mutation rate during DNA duplication and so an active p53 protein responds by eliminating clones of cells with mutations employing apoptosis, senescence or cell cycle arrest. In this way the p53 protein acts as a tumor suppressor preventing the mutations that can lead to cancers. The p63 and p73 proteins act in a similar fashion to protect the germ line cells in females (eggs). In addition the p63 protein plays a central role in the formation of epithelial cell layers and p73 plays a critical role in the formation of several structures in the central nervous system. Based upon their amino acid sequences and structural considerations the oldest organisms that contain an ancestor of the p53/p63/p73 gene are the sea anemone or hydra. The present day representatives of these animals contain a p63/p73 like ancestor gene and the protein functions in germ cells of this animal to enforce the fidelity of DNA replication after exposure to ultraviolet light. Thus the structure and functions of this gene family have been preserved for over one billion years of evolution. Other invertebrates such as the worm, the fly and the clam contain a very similar ancestor gene with a similar set of functions. The withdrawal of a food source from a worm results in the p63/p73 mediated apoptosis of the eggs so that new organisms will not be hatched into a poor environment. A similar response is thought to occur in humans. Thus this ancestor gene ensures the fidelity of the next generation of organisms. The first time a clearly distinct new p53 gene arises is in the cartilaginous fish and in the bony fish a separation of the p

  16. IGFBP7 is a p53 target gene inactivated in human lung cancer by DNA hypermethylation.

    Science.gov (United States)

    Chen, Yuan; Cui, Tiantian; Knösel, Thomas; Yang, Linlin; Zöller, Kristin; Petersen, Iver

    2011-07-01

    Insulin-like growth factor binding protein 7 (IGFBP7) was considered a tumor suppressor gene in lung cancer. However, the mechanism responsible for the downregulation of this gene has not yet been fully understood. In this study, we analyzed the epigenetic inactivation of IGFBP7 expression in human lung cancer. We found that 14 out of 16 lung cancer cell lines showed decreased expression of IGFBP7 compared to control cells by real-time RT-PCR, and 42 out of 90 patients (46.7%) with primary lung tumor exhibited negative staining of IGFBP7 by immunohistochemistry analysis. The IGFBP7 expression could be restored by demethylation agent 5-aza-2'-deoxycytidine (DAC) in 7 cancer cell lines. Methylation status of IGFBP7 was further evaluated by bisulfite sequencing (BS) and methylation-specific-PCR (MSP). It turned out that low expression of IGFBP7 was associated with DNA methylation in lung cancer cell lines and in primary lung tumors (P=0.019). To explore the regulatory role of p53 on IGFBP7, we transfected a wild type p53 expression vector into lung cancer cell lines H1299, H2228, and H82. Forced expression of p53 increased IGFBP7 expression only in H82 harboring no IGFBP7 methylation, while transfection in combination with DAC induced the expression of IGFBP7 in H1299 and H2228, in which IGFBP7 was methylated. Additionally, treatment with p53 inducer adriamycin (ADR) alone or in combination with DAC increased the expression of IGFBP7 in the 3 cell lines. Our data suggest that IGFBP7 is inactivated in lung cancer by DNA hypermethylation in both lung cancer cell lines and primary lung tumors, and IGFBP7 might be regulated by p53 in lung cancer cells. PMID:21095038

  17. Prognostic Significance and Gene Expression Profiles of p53 Mutations in Microsatellite-Stable Stage III Colorectal Adenocarcinomas

    OpenAIRE

    Katkoori, Venkat R.; Shanmugam, Chandrakumar; Jia, Xu; Vitta, Swaroop P.; Sthanam, Meenakshi; Callens, Tom; Messiaen, Ludwine; Chen, Dongquan; Zhang, Bin; Bumpers, Harvey L.; Samuel, Temesgen; Manne, Upender

    2012-01-01

    Although the prognostic value of p53 abnormalities in Stage III microsatellite stable (MSS) colorectal cancers (CRCs) is known, the gene expression profiles specific to the p53 status in the MSS background are not known. Therefore, the current investigation has focused on identification and validation of the gene expression profiles associated with p53 mutant phenotypes in MSS Stage III CRCs. Genomic DNA extracted from 135 formalin-fixed paraffin-embedded tissues, was analyzed for microsatell...

  18. p53 gene targeting by homologous recombination in fish ES cells.

    Directory of Open Access Journals (Sweden)

    Yan Yan

    Full Text Available BACKGROUND: Gene targeting (GT provides a powerful tool for the generation of precise genetic alterations in embryonic stem (ES cells to elucidate gene function and create animal models for human diseases. This technology has, however, been limited to mouse and rat. We have previously established ES cell lines and procedures for gene transfer and selection for homologous recombination (HR events in the fish medaka (Oryzias latipes. METHODOLOGY AND PRINCIPAL FINDINGS: Here we report HR-mediated GT in this organism. We designed a GT vector to disrupt the tumor suppressor gene p53 (also known as tp53. We show that all the three medaka ES cell lines, MES1∼MES3, are highly proficient for HR, as they produced detectable HR without drug selection. Furthermore, the positive-negative selection (PNS procedure enhanced HR by ∼12 folds. Out of 39 PNS-resistant colonies analyzed, 19 (48.7% were positive for GT by PCR genotyping. When 11 of the PCR-positive colonies were further analyzed, 6 (54.5% were found to be bona fide homologous recombinants by Southern blot analysis, sequencing and fluorescent in situ hybridization. This produces a high efficiency of up to 26.6% for p53 GT under PNS conditions. We show that p53 disruption and long-term propagation under drug selection conditions do not compromise the pluripotency, as p53-targeted ES cells retained stable growth, undifferentiated phenotype, pluripotency gene expression profile and differentiation potential in vitro and in vivo. CONCLUSIONS: Our results demonstrate that medaka ES cells are proficient for HR-mediated GT, offering a first model organism of lower vertebrates towards the development of full ES cell-based GT technology.

  19. Selective G to T mutations of p53 gene in hepatocellular carcinoma from southern Africa.

    Science.gov (United States)

    Bressac, B; Kew, M; Wands, J; Ozturk, M

    1991-04-01

    Hepatocellular carcinoma (HCC) is a prevalent cancer in sub-Saharan Africa and eastern Asia. Hepatitis B virus and aflatoxins are risk factors for HCC, but the molecular mechanism of human hepatocellular carcinogenesis is largely unknown. Abnormalities in the structure and expression of the tumour-suppressor gene p53 are frequent in HCC cell lines, and allelic losses from chromosome 17p have been found in HCCs from China and Japan. Here we report on allelic deletions from chromosome 17p and mutations of the p53 gene found in 50% of primary HCCs from southern Africa. Four of five mutations detected were G----T substitutions, with clustering at codon 249. This mutation specificity could reflect exposure to a specific carcinogen, one candidate being aflatoxin B1 (ref. 7), a food contaminant in Africa, which is both a mutagen that induces G to T substitution and a liver-specific carcinogen.

  20. p53 family members regulate the expression of the apolipoprotein D gene.

    Science.gov (United States)

    Sasaki, Yasushi; Negishi, Hideaki; Koyama, Ryota; Anbo, Naoki; Ohori, Kanae; Idogawa, Masashi; Mita, Hiroaki; Toyota, Minoru; Imai, Kohzoh; Shinomura, Yasuhisa; Tokino, Takashi

    2009-01-01

    p73 and p63 are members of the p53 gene family that play an important role in development and homeostasis, mainly by regulating transcription of a variety of genes. We report here that apolipoprotein D (apoD), a member of the lipocalin superfamily of lipid transport proteins, is a direct transcriptional target of the p53 family member genes. We found that the expression of apoD was specifically up-regulated by either TAp73 or TAp63 but not significantly by p53. In addition, apoD transcription is activated in response to cisplatin in a manner dependent on endogenous p73. By using small interference RNA designed to target p73, we demonstrated that silencing endogenous p73 abolishes induction of apoD transcription following cisplatin treatment. We also identified a p73/p63-binding site in the promoter of the apoD gene that is responsive to the p53 family members. The ectopic expression of TAp73 as well as the addition of recombinant human apoD to culture medium induced the osteoblastic differentiation of the human osteosarcoma cell line Saos-2, as assessed by alkaline phosphatase activity. Importantly, apoD knockdown abrogated p73-mediated alkaline phosphatase induction. Moreover, TAp73-mediated apoD expression was able to induce morphological differentiation, as well as expression of neuronal markers, in the human neuroblastoma cell line SH-SY5Y. These results suggest that apoD induction may mediate the activity of p73 in normal development. PMID:19001418

  1. Rescue of non-sense mutated p53 tumor suppressor gene by aminoglycosides

    OpenAIRE

    Floquet, Célia; Deforges, Jules; Rousset, Jean-Pierre; Bidou, Laure

    2010-01-01

    Mutation-based treatments are a new development in genetic medicine, in which the nature of the mutation dictates the therapeutic strategy. Interest has recently focused on diseases caused by premature termination codons (PTCs). Drugs inducing the readthrough of these PTCs restore the production of a full-length protein. In this study, we explored the possibility of using aminoglycoside antibiotics to induce the production of a full-length functional p53 protein from a gene carrying a PTC. We...

  2. Point Mutations Effects on Charge Transport Properties of the Tumor-Suppressor Gene p53

    OpenAIRE

    Shih, Chi-Tin; Roche, Stephan; Römer, Rudolf A.

    2007-01-01

    We report on a theoretical study of point mutations effects on charge transfer properties in the DNA sequence of the tumor-suppressor p53 gene. On the basis of effective single-strand or double-strand tight-binding models which simulate hole propagation along the DNA, a statistical analysis of charge transmission modulations associated with all possible point mutations is performed. We find that in contrast to non-cancerous mutations, mutation hotspots tend to result in significantly weaker {...

  3. Dopaminergic neuron-specific deletion of p53 gene is neuroprotective in an experimental Parkinson's disease model.

    Science.gov (United States)

    Qi, Xin; Davis, Brandon; Chiang, Yung-Hsiao; Filichia, Emily; Barnett, Austin; Greig, Nigel H; Hoffer, Barry; Luo, Yu

    2016-09-01

    p53, a stress response gene, is involved in diverse cell death pathways and its activation has been implicated in the pathogenesis of Parkinson's disease (PD). However, whether the neuronal p53 protein plays a direct role in regulating dopaminergic (DA) neuronal cell death is unknown. In this study, in contrast to the global inhibition of p53 function by pharmacological inhibitors and in traditional p53 knock-out (KO) mice, we examined the effect of DA specific p53 gene deletion in DAT-p53KO mice. These DAT-p53KO mice did not exhibit apparent changes in the general structure and neuronal density of DA neurons during late development and in aging. However, in DA-p53KO mice treated with the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), we found that the induction of Bax and p53 up-regulated modulator of apoptosis (PUMA) mRNA and protein levels by MPTP were diminished in both striatum and substantia nigra of these mice. Notably, deletion of the p53 gene in DA neurons significantly reduced dopaminergic neuronal loss in substantia nigra, dopaminergic neuronal terminal loss at striatum and, additionally, decreased motor deficits in mice challenged with MPTP. In contrast, there was no difference in astrogliosis between WT and DAT-p53KO mice in response to MPTP treatment. These findings demonstrate a specific contribution of p53 activation in DA neuronal cell death by MPTP challenge. Our results further support the role of programmed cell death mediated by p53 in this animal model of PD and identify Bax, BAD and PUMA genes as downstream targets of p53 in modulating DA neuronal death in the in vivo MPTP-induced PD model. We deleted p53 gene in dopaminergic neurons in late developmental stages and found that DA specific p53 deletion is protective in acute MPTP animal model possibly through blocking MPTP-induced BAX and PUMA up-regulation. Astrocyte activation measured by GFAP positive cells and GFAP gene up-regulation in the striatum shows no difference

  4. Apoptosis, proliferation and p53 gene expression of H. pylori associated gastric epithelial lesions

    Institute of Scientific and Technical Information of China (English)

    Zhong Zhang1; Yuan Yuan; Hua Gao; Ming Dong; Lan Wang; Yue-Hua Gong

    2001-01-01

    AIM: To study the relationship between Helicobacter pylori (H. Pylori) and gastric carcinoma and its possible pathogenesis by H. Pylori. METHODS: DNEL technique and immunohistochemical technique were used to study the state of apoptosis,proliferation and p53 gene expression. A total of 100 gastric mucosal biopsy specimens, including 20 normal mucosa, 30H. Pylori-negative and 30 H. Pylorf-positive gastric precancerous lesions along with 20 gastric carcinomas were studied. RESULTS: There were several apoptotic cells in the superficial epithelium and a few proliferative cells within the neck of gastric glands, and no p53 protein expression in normal mucosa. In gastric carcinoma, there were few apoptotic cells, while there were a large number of proliferative cells, and expression of p53 protein significantly was increased. In the phase of metaplasia, the apoptotic index (Al, 4.36% ± 1.95%), proliferative index (PI, 19.11% ± 6.79%) and positivity of p53 expression (46.7%) in H. Pylori-positive group were higher than those in normal mucosa (P< 0.01). Al in H. Pylori-positive group was higher than that in H. Pylori-negative group (3.81% ±1.76%), PI in H. Pylori-positive group was higher than that in H. Pylori-negative group (12.25% ±5.63%, P<0.01 ). In the phase of dysplasia, Al (2.31% ± 1.10%) in H. Pylori-positive group was lower (3.05% ± 1.29%) than that in H. Pylori-negative group, but PI (33.89% ± 11.65%)wassignificantly higher(22.09± 8018%, P< 0.01). In phases of metaplasia, dysplasia and gastric cancer in the H. Pylori-positive group, Als had an evidently graduall decreasing trend (P < 0.01 ), while Pis had an evidently gradual increasing trend (P< 0.05 or P< 0.01), and there was also a trend of gradual increase in the expression of p53 gene. CONCLUSION: In the course of the formation of gastric carcinoma, proliferation of gastric mucosa can be greatly increased by H. Pylori, and H. Pylori can induce apoptosis in the phase of metaplasia but in the phase of

  5. Radiosensitivity of cancer cells against carbon-ion beams in an aspect of the p53 gene status

    International Nuclear Information System (INIS)

    We can easily understand that radiation sensitivities of cancer cells are dependent on the status of cancer-related genes. It is important to clarify which genes affect radiation sensitivity and reflect the effectiveness of radiation therapy for cancer cells. We have studied about the function of a tumor suppressor gene of p53, because p53 controls apoptosis, cell cycle and DNA repair from an aspect of important roles in cell fate. By analysis of function of p53 gene, therefore, we aim to predict the therapeutic effectiveness and to select the modalities of cancer therapies such as radiotherapy, chemotherapy and hyperthermia. As a final goal, we want to accept the most effective therapy, namely tailor-made cancer therapy, for each patient. Here, we introduce that carbon-beam therapy induced the expression of p53-independent apoptosis-related genes and NO radicals in mutated p53 cancer cells. (author)

  6. Correlation of p53 over-expression and alteration in p53 gene detected by polymerase chain reaction-single strand conformation polymorphism in adenocarcinoma of gastric cancer patients from India

    Institute of Scientific and Technical Information of China (English)

    Sajjad Karim; Arif Ali

    2009-01-01

    AIM: To study the alterations in p53 gene among Indian gastric cancer patients and to correlate them with the various clinicopathological parameters.METHODS: A total of 103 gastric cancer patients were included in this study. The p53 alterations were studied by both immunohistochemical method as well as polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis. We only studied four (exon 5, 6, 7, and 8) of the 11 p53 exons. The alterations in p53 were also correlated with respect to various clinicopathological parameters.RESULTS: Among 103 cases, p53 over-expression and alteration were detected in 37 (35.92%) and 19 (18.44%) cases, respectively. Most of the p53 alterations were found at exon 5 (31.54%), followed by exon 6 (26.31%), exon 7 (21.04%) and exon 8 (21.04%). A significant correlation of p53 overexpression was found with p53 alteration ( P = 0.000).Concordance between p53 alteration (as detected by SSCP) and over-expression [as detected by immunohistochemistry (IHC)] was found in 75% cases.We found that IHC-positive/SSCP-negative cases accounted for 21% of cases and IHC-negative/SSCPpositive cases accounted for remaining 4% cases.CONCLUSION: Our results show that p53 gene mutations are significantly correlated with p53 protein over-expression, with 75% concordance in overexpression and alteration in the p53 gene, but 25% disconcordance also cautions against the assumption that p53 over-expression is always associated with a gene mutation. There may be other mechanisms responsible for stabilization and accumulation of p53 protein with no evidence of gene mutation that reflect an accumulation of a non-mutated protein, or a false negative SSCP result.

  7. Heterogeneous breakpoints on the immunoglobulin genes are involved in fusion with the 5' region of BCL2 in B-cell tumors.

    Science.gov (United States)

    Yonetani, N; Ueda, C; Akasaka, T; Nishikori, M; Uchiyama, T; Ohno, H

    2001-09-01

    The 5' flanking region of the BCL2 gene (5'-BCL2) is a breakpoint cluster of rearrangements with immunoglobulin genes (IGs). In contrast to t(14;18)(q32;q21) affecting the 3' region of BCL2, 5'-BCL2 can fuse to not only the heavy chain gene (IGH), but also two light chain gene (IGL) loci. We report here cloning and sequencing of a total of eleven 5'-BCL2 / IGs junctional areas of B-cell tumors, which were amplified by long-distance polymerase chain reaction-based assays. The breakpoints on 5'-BCL2 were distributed from 378 to 2312 bp upstream of the translational initiation site and, reflecting the alteration of regulatory sequences of BCL2, 5'-BCL2 / IGs-positive cells showed markedly higher levels of BCL2 expression than those of t(14;18)-positive cells. In contrast, the breakpoints on the IGs were variable. Two 5'-BCL2 / IGH and two 5'-BCL2 / IGLkappa junctions occurred 5' of the joining (J) segments, suggesting operation of an erroneous variable (V) / diversity (D) / J and V / J rearrangement mechanism. However, two other 5'-BCL2 / IGH junctions affected switch regions, and the kappa-deleting element, which is located 24 kb downstream of the constant region of IGLkappa, followed the 5'-BCL2 in another case. One 5'-BCL2 / IGLkappa and two 5'-BCL2 / IGLlambda junctions involved intronic regions where the normal recombination process does not occur. In the remaining one case, the 5'-BCL2 fused 3' of a Vlambda gene that was upstream of another Vlambda / Jlambda complex carrying a non-producing configuration, indicating that the receptor editing mechanism was likely involved in this rearrangement. Our study revealed heterogeneous anatomy of the 5'-BCL2 / IGs fusion gene leading to transcriptional activation of BCL2, and suggested that the mechanisms underlying the formation of this particular oncogene / IGs recombination are not identical to those of t(14;18).

  8. SPATA18, a Spermatogenesis-Associated Gene, Is a Novel Transcriptional Target of p53 and p63▿

    Science.gov (United States)

    Bornstein, Chamutal; Brosh, Ran; Molchadsky, Alina; Madar, Shalom; Kogan-Sakin, Ira; Goldstein, Ido; Chakravarti, Deepavali; Flores, Elsa R.; Goldfinger, Naomi; Sarig, Rachel; Rotter, Varda

    2011-01-01

    The transcription factor p53 functions not only to suppress tumorigenesis but also to maintain normal development and homeostasis. Although p53 was implicated in different aspects of fertility, including spermatogenesis and implantation, the mechanism underlying p53 involvement in spermatogenesis is poorly resolved. In this study we describe the identification of a spermatogenesis-associated gene, SPATA18, as a novel p53 transcriptional target and show that SPATA18 transcription is induced by p53 in a variety of cell types of both human and mouse origin. p53 binds a consensus DNA motif that resides within the first intron of SPATA18. We describe the spatiotemporal expression patterns of SPATA18 in mouse seminiferous tubules and suggest that SPATA18 transcription is regulated in vivo by p53. We also demonstrate the induction of SPATA18 by p63 and suggest that p63 can compensate for the loss of p53 activity in vivo. Our data not only enrich the known collection of p53 targets but may also provide insights on spermatogenesis defects that are associated with p53 deficiency. PMID:21300779

  9. The p53 gene as a modifier of intrinsic radiosensitivity: implications for radiotherapy

    International Nuclear Information System (INIS)

    cellular phenotypes, including the radioresistant phenotype. Pre-clinical studies suggest that these phenotypes may be reversed using adenovirus-mediated gene therapy or pharmacologic strategies designed to re-institute WTp53 protein function. Our analysis of the published data strongly argues for the use offunctional assays for the determination of WTp53 protein function in studies which attempt to correlate normal and tumour tissue radioresponse with p53 genotype, or p53 protein expression

  10. Both p53-PUMA/NOXA-Bax-mitochondrion and p53-p21cip1 pathways are involved in the CDglyTK-mediated tumor cell suppression

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Zhendong, E-mail: zdyu@hotmail.com [Department of Clinical laboratory, Peking University Shenzhen Hospital, Guangdong (China); Wang, Hao [Department of pathology, The Chinese University of Hong Kong, Hong Kong (China); Zhang, Libin; Tang, Aifa; Zhai, Qinna; Wen, Jianxiang; Yao, Li [Department of Clinical laboratory, Peking University Shenzhen Hospital, Guangdong (China); Li, Pengfei, E-mail: lipengfei@cuhk.edu.hk [Department of pathology, The Chinese University of Hong Kong, Hong Kong (China)

    2009-09-04

    CDglyTK fusion suicide gene has been well characterized to effectively kill tumor cells. However, the exact mechanism and downstream target genes are not fully understood. In our study, we found that CDglyTK/prodrug treatment works more efficiently in p53 wild-type (HONE1) cells than in p53 mutant (CNE1) cells. We then used adenovirus-mediated gene delivery system to either knockdown or overexpress p53 and its target genes in these cells. Consistent results showed that both p53-PUMA/NOXA/Bcl2-Bax and p53-p21 pathways contribute to the CDglyTK induced tumor cell suppression. Our work for the first time addressed the role of p53 related genes in the CDglyTK/prodrug system.

  11. Both p53-PUMA/NOXA-Bax-mitochondrion and p53-p21cip1 pathways are involved in the CDglyTK-mediated tumor cell suppression

    International Nuclear Information System (INIS)

    CDglyTK fusion suicide gene has been well characterized to effectively kill tumor cells. However, the exact mechanism and downstream target genes are not fully understood. In our study, we found that CDglyTK/prodrug treatment works more efficiently in p53 wild-type (HONE1) cells than in p53 mutant (CNE1) cells. We then used adenovirus-mediated gene delivery system to either knockdown or overexpress p53 and its target genes in these cells. Consistent results showed that both p53-PUMA/NOXA/Bcl2-Bax and p53-p21 pathways contribute to the CDglyTK induced tumor cell suppression. Our work for the first time addressed the role of p53 related genes in the CDglyTK/prodrug system.

  12. Insights into p53 transcriptional function via genome-wide chromatin occupancy and gene expression analysis

    OpenAIRE

    F Nikulenkov; Spinnler, C; Li, H.; Tonelli, C; Shi, Y; Turunen, M.; Kivioja, T; Ignatiev, I.; Kel, A; Taipale, J; Selivanova, G

    2012-01-01

    The tumor-suppressor p53 can induce various biological responses. Yet, it is not clear whether it is p53 in vivo promoter selectivity that triggers different transcription programs leading to different outcomes. Our analysis of genome-wide chromatin occupancy by p53 using chromatin immunoprecipitation (ChIP)-seq revealed ‘p53 default program', that is, the pattern of major p53-bound sites that is similar upon p53 activation by nutlin3a, reactivation of p53 and induction of tumor cell apoptosi...

  13. How contemporary human reproductive behaviors influence the role of fertility-related genes: the example of the p53 gene.

    Directory of Open Access Journals (Sweden)

    Rosa Maria Corbo

    Full Text Available Studies on human fertility genes have identified numerous risk/protective alleles involved in the occurrence of reproductive system diseases causing infertility or subfertility. Investigations we carried out in populations at natural fertility seem to suggest that the clinical relevance that some fertility genes are now acquiring depends on their interaction with contemporary reproductive behaviors (birth control, delayed childbearing, and spacing birth order, among others. In recent years, a new physiological role in human fertility regulation has emerged for the tumor- suppressor p53 gene (P53, and the P53 Arg72Pro polymorphism has been associated with recurrent implantation failure in humans. To lend support to our previous observations, we examined the impact of Arg72Pro polymorphism on fertility in two samples of Italian women not selected for impaired fertility but collected from populations with different (premodern and modern reproductive behaviors. Among the women at near-natural fertility (n = 98, the P53 genotypes were not associated with different reproductive efficiency, whereas among those with modern reproductive behaviors (n = 68, the P53 genotypes were associated with different mean numbers of children [Pro/Pro = 0.75P53 Pro allele frequencies (p = 0.028 was observed. These results are consistent with those of clinical studies reporting an association between the P53 Pro allele and recurrent implantation failure. By combining these findings with previous ones, we suggest here that some common variants of fertility genes may have become "detrimental" following exposure to modern reproductive patterns and might therefore be associated with reduced reproductive success. Set within an evolutionary framework, this change could lead to the selection of a set of gene variants fitter to current reproductive behaviors as the

  14. Breeding Reproducing and Identifying for p53 Gene Knockout Mice%p53基因敲除小鼠的饲养繁殖及鉴定

    Institute of Scientific and Technical Information of China (English)

    乔录新; 徐萌; 柴梦音; 乔欣; 陈德喜

    2012-01-01

    目的 为了繁育和鉴定p53基因敲除小鼠,将引进的杂合子小鼠进行饲养繁殖,杂合子用于继续保种.方法 对其幼鼠剪尾提取基因组DNA,采用PCR方法进行基因型鉴定.结果 对引进小鼠已成功饲养和繁殖,并得到纯合基因缺失型小鼠.结论 正确的饲养、繁殖及基因鉴定方法对于基因敲除小鼠的获得和保种具有重要的意义.%Objective To breed and identify p53 gene knockout mice, Heterozygote mice were bred and reproduced. Methods Genome DNA extracted from the mice' s tails were subjected to PCR test for genotype identification. Results Heterozygous were used to acquire baby mice for Protection species. Conclusion The breeding and reproducing were successful and Homozygous genotype mice were acquired. Appropriate methods of feeding, breeding and identifying are important for obtaining gene knockout mice and protecting species.

  15. Effect of chronic intraperitoneal aminoguanidine on memory and expression of Bcl-2 family genes in diabetic rats.

    Science.gov (United States)

    Alipour, Mohsen; Adineh, Fatemeh; Mosatafavi, Hossein; Aminabadi, Azam; Monirinasab, Hananeh; Jafari, Mohammad Reza

    2016-06-01

    Long-term hyperglycemia associates with memory defects via hippocampal cells damaging. The aim of the present study was to examine the effect of 1 month of i.p. injections of AG on passive avoidance learning (PAL) and hippocampal apoptosis in rat. Eighty male rats were divided into 10 groups: control, nondiabetics and STZ-induced diabetics treated with AG (50, 100, 200, and 400 mg/kg, i.p.). PAL and the Bcl-2 family gene expressions were determined. Diabetes resulted in memory and Bcl-2 family gene expression deficits. AG (50 and 100 mg/kg) significantly improved the learning and Bcl-2, Bcl-xl, Bax, and Bak impairment in diabetic rats. However, negative effects were indicated by higher doses of the drug (200 and 400 mg/kg). Present study suggests that 1 month of i.p. injections of lower doses of AG, may improve the impaired cognitive tasks in STZ-induced diabetic rats possibly by modulating Bcl-2 family gene expressions. PMID:27210113

  16. Clinical implications of cytosine deletion of exon 5 of P53 gene in non small cell lung cancer patients

    Directory of Open Access Journals (Sweden)

    Rashid Mir

    2016-01-01

    Full Text Available Aim: Lung cancer is considered to be the most common cancer in the world. In humans, about 50% or more cancers have a mutated tumor suppressor p53 gene thereby resulting in accumulation of p53 protein and losing its function to activate the target genes that regulate the cell cycle and apoptosis. Extensive research conducted in murine cancer models with activated p53, loss of p53, or p53 missense mutations have facilitated researchers to understand the role of this key protein. Our study was aimed to evaluate the frequency of cytosine deletion in nonsmall cell lung cancer (NSCLC patients. Methods: One hundred NSCLC patients were genotyped for P53 (exon5, codon168 cytosine deletion leading to loss of its function and activate the target genes by allele-specific polymerase chain reaction. The P53 cytosine deletion was correlated with all the clinicopathological parameters of the patients. Results and Analysis: 59% cases were carrying P53 cytosine deletion. Similarly, the significantly higher incidence of cytosine deletion was reported in current smokers (75% in comparison to exsmoker and nonsmoker. Significantly higher frequency of cytosine deletion was reported in adenocarcinoma (68.08% than squamous cell carcinoma (52.83%. Also, a significant difference was reported between p53 cytosine deletion and metastasis (64.28%. Further, the majority of the cases assessed for response carrying P53 cytosine deletion were found to show faster disease progression. Conclusion: The data suggests that there is a significant association of the P53 exon 5 deletion of cytosine in codon 168 with metastasis and staging of the disease.

  17. Induction of apoptosis in cancer cells through N-acetyl-l-leucine-modified polyethylenimine-mediated p53 gene delivery.

    Science.gov (United States)

    Li, Zhiyuan; Zhang, Liu; Li, Quanshun

    2015-11-01

    Herein, N-acetyl-L-leucine-modified polyethylenimine was successfully constructed through the EDC/NHS-mediated coupling reaction and employed as vectors to accomplish p53 gene delivery using HeLa (p53wt) and PC-3 cells (p53null) as models. Compared with PEI25K, the derivatives exhibited lower cytotoxicity, protein adsorption and hemolytic activity, together with satisfactory pDNA condensation capability and gene transfection efficiency. After p53 transfection, MTT analysis confirmed that the cell proliferation was inhibited. Flow cytometric analysis showed that the derivative-mediated p53 delivery could induce stronger early apoptosis than PEI25K and Lipofectamine(2000). Further, PC-3 cells showed higher sensitivity to the exogenous p53 transfection than HeLa cells. The mechanism for inducing apoptosis was determined to be up-regulation of p53 expression at both mRNA and protein levels using RT-PCR and western blotting analysis. Expression level and activity analysis of caspase-3, -8 and -9, and mitochondrial membrane potential measurement revealed that p53 transfection mediated by these derivatives facilitated early apoptosis of tumor cells via a mitochondria-dependent apoptosis pathway. Thus, the derivatives showed potential as biocompatible carriers for realizing effective tumor gene therapy. PMID:26322477

  18. EFFECT OF ADENOVIRUS-MEDIATED p53 GENE TRANSFER ON APOPTOSIS AND RADIOSENSITIVITY OF HUMAN GASTRIC CARCINOMA CELL LINES

    Institute of Scientific and Technical Information of China (English)

    张珊文; 肖绍文; 吕有勇

    2003-01-01

    Objective: To evaluate the effect of adenovirus- mediated p53 gene (Adp53) on apoptosis and radiosensitivity of human gastric carcinoma cell lines. Methods: Recombinant adenovirus expressing wild-type p53 gene was transferred into four human gastric carcinoma cell lines with different p53 genetic status. p53 protein expression was detected by immunohistochemistry assay and western blot assay. Cell survival was assessed using a clonogenic assay. TUNEL assay was used in determination of apoptosis. Four human gastric carcinoma cells infected with Adp53 were irradiated with 4Gy and cell cycle distribution and Sub-G1 peak were assayed by flow cytometry. Results: G2/M arrest, apoptosis and inhibition of tumor cell proliferation were induced by infection at Adp53 at 100 MOI which caused high transfer rate of wild-type p53 and strong expression of p53 protein in four human gastric carcinoma cells. The radio-enhancement ratio of Adp53 at 4Gy were 3.0 for W cell, 3.6 for M cell, 2.2 for neo cell and 2.5 for 823 cell in vitro. Conclusion: This study demonstrated that Adp53 transfer increased cellular apoptosis and radiosensitivity of human gastric carcinoma cell lines in vitro independently on cellular intrinsic p53 status thus supporting the combination of p53 gene therapy with radiotherapy in clinical trials.

  19. Negative Regulation-Resistant p53 Variant Enhances Oncolytic Adenoviral Gene Therapy

    OpenAIRE

    Koo, Taeyoung; Choi, Il-Kyu; Kim, Minjung; Lee, Jung-Sun; Oh, Eonju; Kim, Jungho; Yun, Chae-Ok

    2012-01-01

    Intact p53 function is essential for responsiveness to cancer therapy. However, p53 activity is attenuated by the proto-oncoprotein Mdm2, the adenovirus protein E1B 55kD, and the p53 C-terminal domain. To confer resistance to Mdm2, E1B 55kD, and C-terminal negative regulation, we generated a p53 variant (p53VPΔ30) by deleting the N-terminal and C-terminal regions of wild-type p53 and inserting the transcriptional activation domain of herpes simplex virus VP16 protein. The oncolytic adenovirus...

  20. Chitosan/TPP Nanoparticles as a Gene Delivery Agent For Tumor Suppressant P53

    Science.gov (United States)

    Liu, Gaojun

    In the last decade, non-viral polymeric vectors have become more attractive than their viral counterparts due to their nontoxicity and good biocompatibility. However, one of the major drawbacks is the low transfection efficiency when compared to viruses. In this work, a naturally cationic polysaccharide, chitosan, was cross-linked with negatively charged tripolyphosphate (TPP) to synthesize chitosan/TPP nanoparticles (CNPs) for delivery of plasmid DNA (pDNA). Particle size and zeta potential were characterized for CNPs with chitosan-TPP mass ratios of 4:1 and 6:1 (w/w) using benchtop dynamic light scattering. And both potentiometric titration method and FTIR spectrometer were applied to measure the degree of deacetylation of chitosan. Release kinetics of a model protein (bovine serum albumin, BSA) showed a steady release that reached 7% after 6 days. Besides that, we also assessed the in vitro transfection efficiency of the CNP-pDNA system using fluorescence microscopy, as well as the effect of tumor suppressant p53. Later the release kinetics and encapsulation efficiency of plasmid DNA bound to the CNPs will be investigated. Additionally, we will try to improve the gene transfection efficiency in both MC3T3-E1 and osteosarcoma cells by applying Sonicator 740 therapeutic ultrasound. Key words: gene therapy, non-viral gene vector, chitosan/TPP nanoparticles, ionic gelation, p53.

  1. Rb and p53 gene deletions in lung adenocarcinomas from irradiated and control mice

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.; Woloschak, G.E. [Argonne National Lab., IL (United States). Center for Mechanistic Biology and Biotechnology

    1997-08-01

    This study was conducted on mouse lung adenocarcinoma tissues that were formalin-treated and paraffin-embedded 25 years ago to investigate the large gene deletions of mRb and p53 in B6CF{sub 1} male mice. A total of 80 lung tissue samples from irradiated mice and 40 lung samples from nonirradiated controls were randomly selected and examined in the mRb portion of this study. The results showed a significant (P < 0.05) higher percentage of mRb deletions in lung adenocarcinomas from mice exposed to 60 once-weekly {gamma}-ray doses than those from mice receiving 24 once-weekly {gamma}-ray doses at low doses and low dose rates; however, the percentage was not significantly different (P > 0.05) from that for spontaneous lung adenocarcinomas or lung adenocarcinomas from mice exposed to single-dose {gamma} irradiation at a similar total dose. mRb fragments 3 (71%) and 5 (67%), the parts of the gene that encoded the pocket binding region of Rb protein to adenovirus E1A and SV40 T-antigen, were the most frequently deleted fragments. p53 gene deletion analysis was carried out on normal lungs and lung adenocarcinomas that were initially found to bear mRb deletions. Exons 1,4,5,6, and 9 were chosen to be analyzed.

  2. PARTIAL DELTETION OF p53 GENE IN α PARTICLE-INDUCED TRANSFORMANT OF SYRIAN HAMSTER EMBRYO CELLS

    Institute of Scientific and Technical Information of China (English)

    寿江; 章扬培; 吴德昌

    1996-01-01

    The mutation of p53 gene was detected in Syrian hamster embryo (SHE) cells neoplastically ilfitlatedwith a parties. The level of the p53 mRNA in transformant was obviously higher than that in non-irradiated eounterpm, as measured by Northern blot analysis of total RNA. A pair of primers were designedbased on p53 cDNA sequence to produce the whole length of coding sequence about 1.2 kilobase (Kb) byreverse transcription of mRNA followed by the polymerase chain reaction (RT-PCR), but the length of fragment amplified from transnormant mRNA was about 0. 3Kb, remarkably shorter than that from nor-real SHE cells. Immunohistcchemical analysis of p53 protein showed that no heavy staining was found onslice of tumor derived from transformant inoculated in nude mice with hamster specific p53 monocloned antibody HD200. The results implied that p53 gene had been mutated by deletion, which might lead to lces of p53 protein expression but the increased expression of p53 remained in a particle-induced SHE tranalormant.

  3. Increasing drug resistance in human lung cancer cells by mutant-type p53 gene mediated by retrovirus

    Institute of Scientific and Technical Information of China (English)

    高振强; 高志萍; 刘喜富; 张涛

    1997-01-01

    Human mutant-type (mt) p53 cDNA was synthesized and cloned from human lung cancer cell line GL containing mt-p53 gene by using polymerase chain reaction (PCR). It was confirmed that the mt-p53 cDNA con-tained the complete coding sequence of p53 gene but mutated at codon 245 (G→T) and resulted in glycine to cysteine by sequencing analysis. The retroviral vector pD53M of the mt-p53 was constructed and introduced into the drug-sen-sitive human lung cancer cells GAO in which p53 gene did not mutate. The transfected GAO cells strongly expressed mutant-type p53 protein by immunohistochemistry, showing that pD53M vector could steadily express in GAO cells. The drug resistance to several anticancer agents of GAO cells infected by pD53M increased in varying degrees, with the highest increase of 4-fold, in vitro and in vivo. By quantitative PCR and flow cytometry (FCM) analyses, the expression of MDR1 gene and the activity of P-glycoprotein (Pgp) did not increase, the expression of MRP gene and the activity of m

  4. Research advances on the p53 gene network%p53基因调控网络研究进展

    Institute of Scientific and Technical Information of China (English)

    舒坤贤; 王光利; 邬力祥

    2008-01-01

    肿瘤抑制基因p53表达的p53蛋白是一个通用转录因子,与其上、下游功能相关基因组成了一个复杂的基因调控网络,在这个基因网络中p53基因起着关键作用;DNA损伤、缺氧、原癌基因的激活等均能刺激p53基因表达;p53表达升高后,可通过p53-MDM2反馈环路与泛素系统等对p53表达水平进行精确调节;p53通过调控多种下游/靶基因表达完成多种生物学功能,主要包括阻滞细胞周期、促进细胞凋亡、维持基因组稳定性等;认识p53基因调控网络的功能有助于理解p53及其下游/靶基因间的具体作用机制.

  5. Bcl-2基因与神经生长因子(NGF)抑制神经细胞凋亡的研究%Abaissement role of bcl-2 gene and NGF on the apoptosis of nerve cel s

    Institute of Scientific and Technical Information of China (English)

    韩贵和; 魏威; 顾军

    2013-01-01

    目的探讨原癌基因bcl-2与神经生长因子(NGF)联合应用对抑制神经细胞凋亡的协同作用。方法培养PC12细胞至对数生长期,用100感染复数(multiplicity of infection,MOI)的携带bcl-2基因的慢病毒质粒及未携带bcl-2基因的慢病毒质粒感染PC12细胞。再将其分为A、B、C、D、E、F六组,A组为bcl-2-PC12细胞培养液中不加H2O2及NGF(bcl-2-PC12组);B组为bcl-2-PC12细胞培养液中加H2O2(bcl-2-PC12+ H2O2组);C组为bcl-2-PC12细胞培养液中加H2O2及NGF(bcl-2-PC12+ H2O2+NGF组)。D组为NC-PC12细胞培养液中不加H2O2及NGF(NC-PC12组);E组为NC-PC12细胞培养液中加H2O2(NC-PC12+H2O2组);F组为NC-PC12细胞培养液中加H2O2及NGF(NC-PC12+ H2O2+NGF组)。应用流式细胞仪检测各组细胞的凋亡率,采用BCA(bicinchoninic acid)法检测bcl-2基因表达蛋白浓度,数据进行统计学分析。结果 A组细胞凋亡率较D组低(u=2.16,0.02bcl-2基因表达蛋白浓度高于D组(t=2.87,0.005bcl-2基因及NGF均对正常神经细胞的凋亡有抑制作用,能够增强神经细胞的抗损伤能力,二者联合应用时具有协同作用。%Objective To approach synergia abaissement role of the proto-oncogene bcl-2 and NGF on the apoptosis of nerve cells.Methods PC12 cells were cultured to the logarithmic growth phase,slow virus plasmid carrying the bcl-2 gene and slow virus plasmid infected respectively PC12 cells by 100 MOI.Then they were divided into six groups(groupA,groupB,groupC ,groupD,groupE and groupF ). Group A:PC12 cells with slow virus plasmid carrying the bcl-2 gene.Group B: PC

  6. 结肠癌组织中P53基因及其产物变化的研究%Mutation of P53 Gene and Expression of P53 Protein in Colon Cancer

    Institute of Scientific and Technical Information of China (English)

    张玉敏; 尹德霞; 朱桂钱

    2001-01-01

    目的 探索P53基因突变在结肠癌发生过程中的作用.方法应用多聚酶链反应-单纯构象多态分析及免疫组化ABC法研究结肠癌组织中的P53基因及其产物蛋白质的变化.结果结肠癌中有45%发生P53基因突变,52.50% P53蛋白阳性;所获数据经χ2检验.结论对P53基因突变和P53蛋白的检测可作为判断结肠癌生物学行为的重要标志.

  7. Restoring apoptosis as a strategy for cancer gene therapy: focus on p53 and mda-7.

    Science.gov (United States)

    Lebedeva, Irina V; Su, Zhao Zhong; Sarkar, Devanand; Fisher, Paul B

    2003-04-01

    Understanding the molecular and genetic determinants of cancer will provide unique opportunities for developing rational and effective therapies. Malignant cells are frequently resistant to chemotherapy and radiation induced programmed cell death (apoptosis). This resistance can occur by mutations in the tumor suppressor gene p53. Strategies designed to replace this defective tumor suppressor protein, as well as forced expression of a novel cancer specific apoptosis inducing gene, melanoma differentiation associated gene-7 (mda-7), offer promise for restoring apoptosis in tumor cells. Conditional-replicating viruses that selectively induce cytolysis in tumor cells provides an additional means of targeting cancer cells for destruction. Although these approaches represent works in progress, future refinements will in all likelihood result in the next generation of cancer therapies.

  8. Research progress on the structure and function of the P53 gene%P53基因与肿瘤的研究进展

    Institute of Scientific and Technical Information of China (English)

    田云鹏

    2013-01-01

    编码P53蛋白的P53基因是最重要的肿瘤抑制基因之一.人类的大多数肿瘤都存在着P53途径的失活.变异的P53不仅不具备肿瘤抑制子的功能,还可能发挥促进肿瘤发生、发展的作用.P53的基本功能是对细胞应激的应答.因此,我们就P53基因的结构和功能做一综述.

  9. P-Glycoprotein/MDR1 Regulates Pokemon Gene Transcription Through p53 Expression in Human Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Wei Xu

    2010-08-01

    Full Text Available P-glycoprotein (Pgp, encoded by the multidrug resistance 1 (MDR1 gene, is an efflux transporter and plays an important role in pharmacokinetics. In this study, we demonstrated that the pokemon promoter activity, the pokemon mRNA and protein expression can be significantly inhibited by Pgp. Chromatin immunoprecipitation assay showed that Pgp can bind the pokemon prompter to repress pokemon transcription activity. Furthermore, Pgp regulated pokemon transcription activity through expression of p53 as seen by use of p53 siRNA transfected MCF-7 cells or p53 mutated MDA-MB-231 cells. Moreover, p53 was detected to bind with Pgp in vivo using immunoprecipitation assay. Taken together, we conclude that Pgp can regulate the expression of pokemon through the presence of p53, suggesting that Pgp is a potent regulator and may offer an effective novel target for cancer therapy.

  10. P-Glycoprotein/MDR1 regulates pokemon gene transcription through p53 expression in human breast cancer cells.

    Science.gov (United States)

    He, Shengnan; Liu, Feng; Xie, Zhenhua; Zu, Xuyu; Xu, Wei; Jiang, Yuyang

    2010-01-01

    P-glycoprotein (Pgp), encoded by the multidrug resistance 1 (MDR1) gene, is an efflux transporter and plays an important role in pharmacokinetics. In this study, we demonstrated that the pokemon promoter activity, the pokemon mRNA and protein expression can be significantly inhibited by Pgp. Chromatin immunoprecipitation assay showed that Pgp can bind the pokemon prompter to repress pokemon transcription activity. Furthermore, Pgp regulated pokemon transcription activity through expression of p53 as seen by use of p53 siRNA transfected MCF-7 cells or p53 mutated MDA-MB-231 cells. Moreover, p53 was detected to bind with Pgp in vivo using immunoprecipitation assay. Taken together, we conclude that Pgp can regulate the expression of pokemon through the presence of p53, suggesting that Pgp is a potent regulator and may offer an effective novel target for cancer therapy. PMID:20957096

  11. High Resolution Melting Analysis for Detecting p53 Gene Mutations in Patients with Non-small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Zhihong CHEN

    2011-10-01

    Full Text Available Background and objective It has been proven that p53 gene was related to many human cancers. The mutations in p53 gene play an important role in carcinogensis and mostly happened in exon 5-8. The aim of this study is to establish a high resolution melting (HRM assay to detect p53 mutations from patients with non-small cell lung cancer (NSCLC, to investigate the characteristics of p53 gene mutations, and to analyze the relationship between p53 mutations and evolution regularity of pathogenesis. Methods p53 mutations in exon 5-8 were detected by HRM assay on DNA insolated from 264 NSCLC samples derived from tumor tissues and 54 control samples from pericancerous pulmonary tissues. The mutation samples by the HRM assay were confirmed by sequencing technique. Samples which were positive by HRM but wild type by sequencing were further confirmed by sub-clone and sequencing. Results No mutation was found in 54 pericancerous pulmonary samples by HRM assay. 104 of the 264 tumor tissues demonstrated mutation curves by HRM assay, 102 samples were confirmed by sequencing, including 95 point mutations and 7 frame shift mutations by insertion or deletion. The mutation rate of p53 gene was 39.4%. The mutation rate from exon 5-8 were 11.7%, 8%, 12.5% and 10.6%, respectively and there was no statistically significant difference between them (P=0.35. p53 mutations were significantly more frequent in males than that in females, but not related to the other clinicopathologic characteristics. Conclusion The results indicate that HRM is a sensitive in-tube methodology to detect for mutations in clinical samples. The results suggest that the arising p53 mutations in NSCLC may be due to spontaneous error in DNA synthesis and repair.

  12. p53 represses the transcription of snRNA genes by preventing the formation of little elongation complex.

    Science.gov (United States)

    Anwar, Delnur; Takahashi, Hidehisa; Watanabe, Masashi; Suzuki, Masanobu; Fukuda, Satoshi; Hatakeyama, Shigetsugu

    2016-08-01

    The regulation of transcription by RNA polymerase II (Pol II) is important for a variety of cellular functions. ELL/EAF-containing little elongation complex (LEC) was found to be required for transcription of Pol II-dependent small nuclear RNA (snRNA) genes. It was shown that the tumor suppressor p53 interacts with ELL and inhibits transcription elongation activity of ELL. Here, we show that p53 inhibits interaction between ELL/EAF and ICE1 in LEC and thereby p53 represses transcription of Pol II-dependent snRNA genes through inhibiting LEC function. Furthermore, induction of p53 expression by ultraviolet (UV) irradiation decreases the occupancy of ICE1 at Pol II-dependent snRNA genes. Consistent with the results, knockdown of p53 increased both the expression of snRNA genes and the occupancy of Pol II and components of LEC at snRNA genes. Our results indicate that p53 interferes with the interaction between ELL/EAF and ICE1 and represses transcription of snRNA genes by Pol II.

  13. Prognostic significance and gene expression profiles of p53 mutations in microsatellite-stable stage III colorectal adenocarcinomas.

    Directory of Open Access Journals (Sweden)

    Venkat R Katkoori

    Full Text Available Although the prognostic value of p53 abnormalities in Stage III microsatellite stable (MSS colorectal cancers (CRCs is known, the gene expression profiles specific to the p53 status in the MSS background are not known. Therefore, the current investigation has focused on identification and validation of the gene expression profiles associated with p53 mutant phenotypes in MSS Stage III CRCs. Genomic DNA extracted from 135 formalin-fixed paraffin-embedded tissues, was analyzed for microsatellite instability (MSI and p53 mutations. Further, mRNA samples extracted from five p53-mutant and five p53-wild-type MSS-CRC snap-frozen tissues were profiled for differential gene expression by Affymetrix Human Genome U133 Plus 2.0 arrays. Differentially expressed genes were further validated by the high-throughput quantitative nuclease protection assay (qNPA, and confirmed by quantitative real-time polymerase chain reaction (qRT-PCR and by immunohistochemistry (IHC. Survival rates were estimated by Kaplan-Meier and Cox regression analyses. A higher incidence of p53 mutations was found in MSS (58% than in MSI (30% phenotypes. Both univariate (log-rank, P = 0.025 and multivariate (hazard ratio, 2.52; 95% confidence interval, 1.25-5.08 analyses have demonstrated that patients with MSS-p53 mutant phenotypes had poor CRC-specific survival when compared to MSS-p53 wild-type phenotypes. Gene expression analyses identified 84 differentially expressed genes. Of 49 down-regulated genes, LPAR6, PDLIM3, and PLAT, and, of 35 up-regulated genes, TRIM29, FUT3, IQGAP3, and SLC6A8 were confirmed by qNPA, qRT-PCR, and IHC platforms. p53 mutations are associated with poor survival of patients with Stage III MSS CRCs and p53-mutant and wild-type phenotypes have distinct gene expression profiles that might be helpful in identifying aggressive subsets.

  14. Phosphatidylinositol 3-kinase is essential for kit ligand-mediated survival, whereas interleukin-3 and flt3 ligand induce expression of antiapoptotic Bcl-2 family genes

    DEFF Research Database (Denmark)

    Karlsson, Richard; Engström, Maria; Jönsson, Maria;

    2003-01-01

    affect the survival. We next established if IL-3 and FL activated antiapoptotic Bcl-2 and the related genes Bcl-XL and Mcl-1. By RNA protection assay and Western blot analysis, we show that all three genes are induced by IL-3, whereas FL induces Bcl-2 and to some extent Bcl-XL. Importantly, KL could not...... sustain their expression. Moreover, use of inhibitors implied that IL-3 was mainly exerting its effect on Bcl-2 at the level of transcription. The addition of LY294002 did not affect the expression of Bcl-2 and Bcl-XL, and thus, we conclude that expression of antiapoptotic Bcl-2 family member genes is not...

  15. Melatonin down-regulates MDM2 gene expression and enhances p53 acetylation in MCF-7 cells.

    Science.gov (United States)

    Proietti, Sara; Cucina, Alessandra; Dobrowolny, Gabriella; D'Anselmi, Fabrizio; Dinicola, Simona; Masiello, Maria Grazia; Pasqualato, Alessia; Palombo, Alessandro; Morini, Veronica; Reiter, Russel J; Bizzarri, Mariano

    2014-08-01

    Compelling evidence demonstrated that melatonin increases p53 activity in cancer cells. p53 undergoes acetylation to be stabilized and activated for driving cells destined for apoptosis/growth inhibition. Over-expression of p300 induces p53 acetylation, leading to cell growth arrest by increasing p21 expression. In turn, p53 activation is mainly regulated in the nucleus by MDM2. MDM2 also acts as E3 ubiquitin ligase, promoting the proteasome-dependent p53 degradation. MDM2 entry into the nucleus is finely tuned by two different modulations: the ribosomal protein L11, acts by sequestering MDM2 in the cytosol, whereas the PI3K-AkT-dependent MDM2 phosphorylation is mandatory for MDM2 translocation across the nuclear membrane. In addition, MDM2-dependent targeting of p53 is regulated in a nonlinear fashion by MDM2/MDMX interplay. Melatonin induces both cell growth inhibition and apoptosis in MCF7 breast cancer cells. We previously reported that this effect is associated with reduced MDM2 levels and increased p53 activity. Herein, we demonstrated that melatonin drastically down-regulates MDM2 gene expression and inhibits MDM2 shuttling into the nucleus, given that melatonin increases L11 and inhibits Akt-PI3K-dependent MDM2 phosphorylation. Melatonin induces a 3-fold increase in both MDMX and p300 levels, decreasing simultaneously Sirt1, a specific inhibitor of p300 activity. Consequently, melatonin-treated cells display significantly higher values of both p53 and acetylated p53. Thus, a 15-fold increase in p21 levels was observed in melatonin-treated cancer cells. Our results provide evidence that melatonin enhances p53 acetylation by modulating the MDM2/MDMX/p300 pathway, disclosing new insights for understanding its anticancer effect. PMID:24920214

  16. Biodegradable Poly(aminoester)-Mediated p53 Gene Delivery for Cancer Therapy.

    Science.gov (United States)

    Shen, He; Liu, Min; Zhang, Zhijun

    2016-03-01

    Gene therapy is a promising strategy in cancer treatment. However, efficient gene translation still remains challenging. In the previous work, a hydrolytically degradable poly(aminoester) with good biocompatibility was synthesized. Herein, the poly(aminoester) was explored as a vector for gene delivery and cancer therapy. The experiments revealed that the poly(aminoester) condensed plasmid DNA into nanosized particles via electrostatic interaction. The pEGFP-N1 and pGL-3 were first used as two reporter genes to study intracellular transfection. The poly(aminoester) showed higher GFP expression (33%) than PEI 25 kDa (21%). Intracellular trafficking of Cy3-labelled pGL-3 also indicated that the poly(aminoester) showed superior DNA delivery ability to nucleus compared to PEI 25 kDa. Furthermore, the therapeutic gene (p53) was translated into the breast cancer cell line (MCF-7), and then induced cell apoptosis. These results suggested that the degradable poly(aminoester) is a promising and efficient gene delivery vector for gene therapeutic applications. PMID:27455620

  17. Investigação do gene p53 de frangos expostos às aflatoxinas

    Directory of Open Access Journals (Sweden)

    A.C.F.G. Cruz

    2012-12-01

    Full Text Available Identificou-se o efeito das aflatoxinas (AFs sobre o gene p53 de frangos de corte, de linhagem comercial, separados em: grupo experimental, tratado (GT com ração comercial contendo 2,8ppm de AFs totais durante 21 dias consecutivos, e grupo-controle (GC, sem exposição às AFs. Macroscopicamente, as alterações caracterizaram-se por hepatomegalia e aspecto pálido-amarelado com alguns focos hemorrágicos e, histologicamente, por desarranjo trabecular, pleomorfismo hepatocítico com cariomegalia, degeneração vacuolar intracitoplasmática, necrose com infiltração linfocítica e hiperplasia de ductos biliares. A PCR com os primers GSPT53c-1 com base no gene candidato a p53 (GenBank XM_424937.2 gerou um produto de aproximadamente 350 pares de base. O amplicon sequenciado a partir do DNA dos frangos do GT não apresentou mutação ou deleção, assim como padrão de bandas do PCR-RFLP não foi distinto entre ambos os grupos experimentais e a sequência depositada no banco de genes. Os resultados sugerem que não ocorreu transversão devido à exposição às AFs no fragmento amplificado. Conclui-se que a PCR-RFLP e o sequenciamento do produto da PCR não são ferramentas apropriadas para diagnóstico da exposição de frangos às AFs nas condições experimentais empregadas.

  18. Chitosan Nanoparticles-Mediated Wild-Type p53 Gene Delivery for Cancer Gene Therapy: Improvement in Pharmaceutical & Biological Properties (Enhance in Loading, Release, Expression and Stability of P53 Plasmid and Induction of Apoptosis in Carcinoma Cell Line

    Directory of Open Access Journals (Sweden)

    Mehrdad Hamidi

    2008-05-01

    Full Text Available Efficient non-viral vectors for gene delivery based on chitosan polymer is dependent on a variety of factors, e.g. loading and lelease capacity, stability in biological system and complex size. This system may have low loading, release and stability capacity. Biodegradable and biocompatible nanoparticles formulated using a chitosan polymer has the potential for sustained and controlled gene delivery. Our hypothesis is that nanoparticles-mediated wild-type p53 gene delivery would result in sustained gene expression, and hence better efficacy with a therapeutic gene. In this study, we have determined the pharmaceutical and biological characterization of Chitosan nanoparticles containing wild-type p53. Nanoparticles containing plasmid were formulated using a microemulsion reverse micellar and ionic gelation techniques. In conclusion, chitosan nanoparticles- p53 complex gene delivery results in sustained and better antiproliferative activity, which could be therapeutically beneficial in cancer treatment.

  19. Expression of the p48 xeroderma pigmentosum gene is p53-dependent and is involved in global genomic repair

    OpenAIRE

    Hwang, Byung Joon; Ford, James M; Hanawalt, Philip C.; Chu, Gilbert

    1999-01-01

    In human cells, efficient global genomic repair of DNA damage induced by ultraviolet radiation requires the p53 tumor suppressor, but the mechanism has been unclear. The p48 gene is required for expression of an ultraviolet radiation-damaged DNA binding activity and is disrupted by mutations in the subset of xeroderma pigmentosum group E cells that lack this activity. Here, we show that p48 mRNA levels strongly depend on basal p53 expression and increase further after DNA damage in a p53-depe...

  20. Immediate-early gene product ICP22 inhibits the trans-transcription activating function of P53-mdm-2

    Institute of Scientific and Technical Information of China (English)

    GUO HongXiong; CUN Wei; LIU LongDing; WANG LiChun; ZHAO HongLing; DONG ChengHong; LI QiHan

    2007-01-01

    As a product of HSVI immediate-early gene, ICP22 is capable of interacting with various cellular transcriptive and regulatory molecules during viral infection so as to impact the normal cellular molecular mechanism. ICP22 expressed in transfected cells can push the cells' entering into S phase with binding to mdm-1 promoter region and impact its trans-transcription activating effect by P53. Consequently, the MDM-2 binds to P53, and the degradation effects by the ubiquitous pathway are decreased, improving indirectly the P53 levels in cells and making the cells progress into the S phase.

  1. Immediate-early gene product ICP22 inhibits the trans-transcription activating function of P53-mdm-2

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    As a product of HSVI immediate-early gene, ICP22 is capable of interacting with various cellular tran-scriptive and regulatory molecules during viral infection so as to impact the normal cellular molecular mechanism. ICP22 expressed in transfected cells can push the cells’ entering into S phase with binding to mdm-1 promoter region and impact its trans-transcription activating effect by P53. Consequently, the MDM-2 binds to P53, and the degradation effects by the ubiquitous pathway are decreased, improving indirectly the P53 levels in cells and making the cells progress into the S phase.

  2. Transient Transfection of a Wild-Type p53 Gene Triggers Resveratrol-Induced Apoptosis in Cancer Cells

    OpenAIRE

    Ferraz da Costa, Danielly Cristiny; Casanova, Fabiana Alves; Quarti, Julia; Malheiros, Maitê Santos; Sanches, Daniel; dos Santos, Patricia Souza; Fialho, Eliane; Silva, Jerson L.

    2012-01-01

    Resveratrol is a promising chemopreventive agent that mediates many cellular targets involved in cancer signaling pathways. p53 has been suggested to play a role in the anticancer properties of resveratrol. We investigated resveratrol-induced cytotoxicity in H1299 cells, which are non-small lung cancer cells that have a partial deletion of the gene that encodes the p53 protein. The results for H1299 cells were compared with those for three cell lines that constitutively express wild-type p53:...

  3. p53,p21在乳癌中的表达及意义%Significance of expression of p53 and p21 gene protein in breastcancer

    Institute of Scientific and Technical Information of China (English)

    赵春临; 吴飞跃

    2001-01-01

    目的探讨p53,p21蛋白在乳癌中表达的临床意义.方法用免疫组化SP法对20例癌旁乳腺组织和69例乳癌组织中p53和p21蛋白进行半定量检测.结果癌旁乳腺组织中p53和 p21表达阴性;乳腺癌组织中p53和p21阳性率分别为47.8%和43.5%;随细胞分化程度降低 ;p53表达阳性率明显升高,p21表达的阳性率明显降低.p21表达的阳性率在有、无淋巴结转移组差异显著(P<0.05);p53阳性、p21阴性组术后5年无瘤生存率明显低于p53 阴性、p21阳性组(P<0.05);在乳癌组织中p21表达与p53明显相关(P<0.05). 结论 p53和p21在乳癌中的表达可判断乳癌细胞分化程度及患者预后.

  4. The Toll-like receptor gene family is integrated into human DNA damage and p53 networks.

    Directory of Open Access Journals (Sweden)

    Daniel Menendez

    2011-03-01

    Full Text Available In recent years the functions that the p53 tumor suppressor plays in human biology have been greatly extended beyond "guardian of the genome." Our studies of promoter response element sequences targeted by the p53 master regulatory transcription factor suggest a general role for this DNA damage and stress-responsive regulator in the control of human Toll-like receptor (TLR gene expression. The TLR gene family mediates innate immunity to a wide variety of pathogenic threats through recognition of conserved pathogen-associated molecular motifs. Using primary human immune cells, we have examined expression of the entire TLR gene family following exposure to anti-cancer agents that induce the p53 network. Expression of all TLR genes, TLR1 to TLR10, in blood lymphocytes and alveolar macrophages from healthy volunteers can be induced by DNA metabolic stressors. However, there is considerable inter-individual variability. Most of the TLR genes respond to p53 via canonical as well as noncanonical promoter binding sites. Importantly, the integration of the TLR gene family into the p53 network is unique to primates, a recurrent theme raised for other gene families in our previous studies. Furthermore, a polymorphism in a TLR8 response element provides the first human example of a p53 target sequence specifically responsible for endogenous gene induction. These findings-demonstrating that the human innate immune system, including downstream induction of cytokines, can be modulated by DNA metabolic stress-have many implications for health and disease, as well as for understanding the evolution of damage and p53 responsive networks.

  5. EFFECTS OF p53 GENE THERAPY COMBINED WITH CYCLOOXYGENASE-2 INHIBITOR ON CYCLOOXYGENASE-2 GENE EXPRESSION AND GROWTH INHIBITION OF HUMAN LUNG CANCER CELLS

    Institute of Scientific and Technical Information of China (English)

    WANG Zhao-Xia; LU Bin-Bin; WANG Teng; YIN Yong-Mei; DE Wei; SHU Yong-Qian

    2007-01-01

    Background Gene therapy by adenovirus-mediated wild-type p53 gene transfer has been shown to inhibit lung cancer growth in vitro, in animal models, and in human clinical trials. The antitumor effect of selective cyclooxygenase (COX)-2 inhibitors has been demonstrated in preclinical studies. However, no information is available on the effects of p53 gene therapy combined with selective COX-2 inhibitor on COX-2 gene expression and growth inhibition of human lung cancer cells. Methods We evaluated the effects of recombinant adenovirus-p53 (Ad-p53) gene therapy combined with selective COX-2 inhibitor on the proliferation, apoptosis, cell cycle arrest of human lung adenocarcinoma A549 cell line, and the effects of tumor suppressor exogenous wild type p53 on COX-2 gene expression. Results Ad-p53 gene therapy combined with selective COX-2 inhibitor celecoxib shows significant synergistic inhibition effects on the growth of human lung adenocarcinoma A549 cell line. Exogenous p53 gene can suppress COX-2 gene expression. Conclusions Significant synergistic inhibition effects of A549 cell line by the combined Ad-p53 and selective COX-2 inhibitor celecoxib may be achieved by enhancement of growth inhibition, apoptosis induction and suppression of COX-2 gene expression. This study provides first evidence that the administration of p53 gene therapy in combination with COX-2 inhibitors might be a new clinical strategy for the treatment or prevention of NSCLC.

  6. Transcriptome profiling identifies genes and pathways deregulated upon floxuridine treatment in colorectal cancer cells harboring GOF mutant p53

    Directory of Open Access Journals (Sweden)

    Arindam Datta

    2016-06-01

    Full Text Available Mutation in TP53 is a common genetic alteration in human cancers. Certain tumor associated p53 missense mutants acquire gain-of-function (GOF properties and confer oncogenic phenotypes including enhanced chemoresistance. The colorectal cancers (CRC harboring mutant p53 are generally aggressive in nature and difficult to treat. To identify a potential gene expression signature of GOF mutant p53-driven acquired chemoresistance in CRC, we performed transcriptome profiling of floxuridine (FUdR treated SW480 cells expressing mutant p53R273H (GEO#: GSE77533. We obtained several genes differentially regulated between FUdR treated and untreated cells. Further, functional characterization and pathway analysis revealed significant enrichment of crucial biological processes and pathways upon FUdR treatment in SW480 cells. Our data suggest that in response to chemotherapeutics treatment, cancer cells with GOF mutant p53 can modulate key cellular pathways to withstand the cytotoxic effect of the drugs. The genes and pathways identified in the present study can be further validated and targeted for better chemotherapy response in colorectal cancer patients harboring mutant p53.

  7. Experimental research on treating hepatic carcinoma by trans-arterial delivery of p53 gene mediated by lipsome combined transferring

    International Nuclear Information System (INIS)

    Objective: To investigate the trans-arterial delivery of p53 gene transfection efficiency and therapy effect on hepatic carcinoma in combination with transferrin mediated by liposome. Methods: Twenty-five VX2 experimental rabbits were randomly divided into five groups, and the different doses of transferrin combined with p53-LipofectAMINE complex were delivered into the hepatic arteries of the VX2 hepatic carcinoma models. The tissue protein of the carcinoma was extracted after 48 h and the transfection efficiency and expression rate of p53 gene were analyzed by western blot and immune histochemical techniques, to inspect the expression proportion of p53 with different doses transferring. Another ten VX2 were divided into two groups, recombinant plasmid p53-LipofectAMINE complex and transferrin-p53-LipofectAMINE complex were delivered into the hepatic arteries in two groups respectively. The liver function, size of the tumor and survival time of the animals was compared between the two groups, and results were analyzed statistically. Results: Semiquantitative analysis by Western Blot showed that the transfection and expression efficiency of p53 gene combined with transferrin were higher than those without it. By immune histochemical techniques, the p53 gene's positive rate of highly expression with various doses of transferrin were found to be different, and there was remarkable difference between the groups with and without transferring. They were 58.33%, 69.44%, 80.00%, 83.33%, 81.67% respectively, there was remarkable difference between the groups with and without transferring (Totality: χ2=42.37, P2 section: 3 groups as former χ2=4.82, P2=0.67, P<0.05). There was no statistical difference in the liver function at points of time between VX2 rabbits with and without transferring. But the tumor's sizes had significant difference at various points of time. Conclusion: Liposome-mediated p53 gene on treating hepatic carcinoma by trans-arterial gene delivery

  8. Association of Matrix Metalloproteinase-9 and p53 Gene Polymorphisms with Genetic Susceptibility to No-small-cell Lung Cancer

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ying-hao; MA Tong-hui; ZHENG Yong-chen; ZHANG Kun; YANG Jing-bo; YANG Long-fei; YANG Zhi-guang; SHAO Guo-guang

    2011-01-01

    Matrix metalloproteinase-9(MMP-9) and p53 genes play an essential role in the multi-step process of tumorigenesis in lung cancer. Single nucleotide polymorphisms(SNPs) of MMP-9 and p53 genes are associated with the risk and progression of many cancers. In this study, we evaluated the association of the R279Q polymo rphism of MMP-9 or the A1/A2 polymorphism of p53 gene with the risk of no-small-cell lung cancer(NSCLC) in Hah population of Northeast China. We examined the frequency of SNPs in the two kinds of genes of 50 patients with NSCLC and 50 cancer-free controls frequency-matched by age and sex. Polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) technique was used to determine the genotypes. The results indicate that the 279RR genotype in MMP-9 gene and the A1/A2 genotype in p53 gene show a significantly increased risk of NSCLC. Therefore,the MMP-9 279RR and p53 A1/A2 genotypes may be used as markers for susceptibility to NSCLC in Han population of Northeast China.

  9. Effects of knocking out Bcl-2 gene on proliferation and apoptosis of human pancreatic cancer cells SW1990%Bcl-2基因敲除对人胰腺癌细胞增殖及凋亡的影响

    Institute of Scientific and Technical Information of China (English)

    魏莉; 张海文; 涂芊茜; 刘斌; 蔡宏剑; 孙春亮; 陈海涛

    2015-01-01

    目的 探讨Bcl-2基因对人胰腺癌SW1990细胞增殖及凋亡的影响.方法 设计并合成靶向Bcl-2基因的sgRNA(Bcl-2-sgRNA),通过CRISPR-Cas9系统将其结合到CRISPR载体Cas9,经测序验证后转染人胰腺癌细胞株SW1990,筛选Bcl-2基因敲除稳转细胞,以野生型SW1990细胞作为对照.采用CCK-8法测定细胞生长曲线,通过克隆形成实验计数细胞克隆数,运用流式细胞仪检测细胞周期及凋亡.结果 成功获得Bcl-2基因敲除的人胰腺癌SW1990细胞株,其Bcl-2蛋白表达缺失.与野生SW1990细胞比较,敲除Bcl-2基因的SW1990细胞的生长被抑制,细胞克隆形成数量显著减少[(160.7±10.0)个比(285.3±14.2)个],G1期细胞比例显著增加[(84.51±0.97)%比(57.49±1.08)%],S期细胞比例显著减少[(12.82±0.99)%比(27.56±1.65)%],细胞凋亡率显著增加[(12.67±0.59)%比(0.37±0.35)%],差异均有统计学意义(P值均<0.01).结论 敲除Bcl-2基因可抑制胰腺癌SW1990细胞的生长,降低细胞克隆形成能力,使细胞阻滞在G1期,并显著增加细胞凋亡率.%Objective To investigate the effect of Bcl-2 gene expression on the proliferation and apoptosis of human pancreatic cancer SW1990 cells.Methods Bcl-2 short guide RNA (Bcl-2-sgRNA) was designed and synthesized,and it was combined with CRISPR-Cas 9.After confirmation by gene sequencing,it was transfected into human pancreatic cancer cell line SW1990,then the cells with stable Bcl-2 gene knock-out were selected,and wild type SW1990 cells were used as control.The cell growth curve was determined by CCK-8 method.The number of clone formation was measured.Flow cytometry was used to measure cell cycle and apoptosis.Results Human pancreatic cancer cell line SW1990 with Bcl-2 gene knock-out was successful constructed.Compared with wild type SW1990 cells,the growth of SW1990 cells with Bcl-2 gene knock-out was inhibited,the number of clone formation was significantly decreased [(160.7 ± 10.0) vs (285.3

  10. Inhibition of human colorectal adenocarcinoma cells with AdCMV-p53 gene transfection induced by irradiation

    International Nuclear Information System (INIS)

    The effect of AdCMV-p53 gene transfection induced by γ-ray irradiation on human colorectal adenocarcinoma cells was investigated. The HT-29 cells were irradiated by 0.5, 1.0, 2.0 Gy 60Co γ-rays, then were transfected with AdCMV-GFP (a replication of deficient recombinant adenoviral vector containing a CMV promoter and green fluorescent protein) or AdCMV-p53 (a replication of deficient recombinant adenoviral vector containing a CMV promoter and carrying human wild p53 gene). Cytotoxity was measured by clonogenic survival assay; apoptosis and the p53 expression were determined by flow cytometry. The results show that the pre-exposure of 0.5 Gy 60Co γ-rays significantly enhanced the inhibition of HT-29 cells with AdCMV-53 transfection and promoted cell apoptosis. The inhibition rates for the groups of pre-exposure with 0.5 Gy and transfection with 40 and 80 MOI AdCMV-p53 were 50% and 20% higher than those for the groups of the mere transfection, and 40% more than the mere irradiation group. In the case of higher than 0.5 Gy pre-exposure, no significant difference was found between the pre-exposure with transfection group and the mere irradiation group. So 0.5 Gy pre-irradiation and AdCMV-p53 transfection obviously increases the inhibition of HT-29 cells with AdCMV-p53 transfection. The optimum condition is the lower than 1.0 Gy pre-exposure combined with the lower than 80 MOI AdCMV-p53 transfection. (authors)

  11. Protective Effect of Isoflurane and Sevoflurane on Ischemic Neurons and Expression of Bcl-2 and ICE Genes in Rat Brain

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    To study the protective effect of volatile anesthetics, isoflurane and sevoflurane, on ischemic neurons after cerebral ischemia-reperfusion in rats and its possible molecular mechanism. Methods Rat cerebral ischemia-reperfusion model was developed by occlusion of the middle cerebral artery (MCA) and bilateral common carotid arteries (CCAs) 1 h after reperfusion. Using flow cytometry (FCM) and Northern blot hybridization, we calculated the number of apoptotic bodies and detected the expression of bcl-2 mRNA and interleukin-1 β converting enzyme (ICE) mRNA. Results The apoptotic bodies in hippocampus analyzed by FCM peaked at appeared 24 h after reperfusion, and decreased about 54% and 40%, respectively,after treatment with isoflurane and sevoflurane, as compared with ischemic group. There was no significant difference in the expression of bcl-2 mRNA and ICE mRNA between the inhaled anesthetic groups and ischemic group in hippocampus 24 hafter MCA/CCAs occlusion. Conclusion Isoflurane and sevoflurane partially inhibit apoptosis but have no significant effect on the expression of bcl-2 and ICE genes.

  12. THE ROLES OF bcl-2 GENE FAMILY IN THE PULMONARY ARTERY REMODELING OF HYPOXIA PULMONARY HYPERTENSION IN RATS

    Institute of Scientific and Technical Information of China (English)

    杨成; 王胜发; 梁桃; 王巨; 王凯; 王柏春

    2001-01-01

    Objective. To investigate the roles of apoptosis in the pulmonary artery remodeling of pulmonary hypertension secondary to hypoxia and illustrate the relative genes expression.Methods. Thirty rats were divided into hypoxia group(10%O2, 8h/d) and normal control group. On the 15th day of hypoxia, pulmonary artery pressure and right ventricular hypertrophy index were measured and pulmonary artery vessels were studied by light microscope. Then terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling(TUNEL)technique was used to detect nucleosomal DNA fragmentation of apoptotic cells.In situ hybridization and RT-PCR were used to detect the expression level of bcl-2 and bax.``Results. The pulmonary artery pressure and right ventricular hypertrophy index of hypoxia group were increased significantly, the pulmonary artery wall of hypoxic group become incrassate than control group. Apoptotic cells can be found in lung with hypoxia or without hypoxia. Compared with control group, apoptotic index of hypoxic group decreased significantly. Through the methods of in situ hybridization and RT-PCR, we found the expression of bcl-2 increased whereas bax decreased significantly in the hypoxic group.``Conclusion. The alternation in bcl-2 and bax expression induced by hypoxia play an important role in the pulmonary artery remodeling which is the main pathologic change of pulmonary hypertension secondary to hypoxia.

  13. Quantitative expression analysis and prognostic significance of the BCL2-associated X gene in nasopharyngeal carcinoma: a retrospective cohort study

    International Nuclear Information System (INIS)

    Nasopharyngeal carcinoma (NPC) is a highly metastatic epithelial malignancy showing high prevalence in Southeast Asia and North Africa. The BCL2-associated X (BAX) gene encodes the most important pro-apoptotic member of the BCL2 family. We have recently shown that BCL2 and BCL2L12, two other members of the same apoptosis-related family, possess significant prognostic value in NPC. The objective of the current study was to analyze BAX mRNA expression in nasopharyngeal biopsies of NPC patients, and to assess its prognostic potential in this disease. Total RNA was isolated from 88 malignant and 9 hyperplastic nasopharyngeal biopsies, resected from Tunisian patients. After cDNA synthesis by reverse transcription of polyadenylated RNA, BAX mRNA expression was analyzed using a highly sensitive quantitative real-time polymerase chain reaction (qRT-PCR) method. Lower BAX mRNA levels were detected in NPC biopsies than in hyperplastic nasopharyngeal samples. BAX mRNA expression status was associated with low tumor extent, negative regional lymph node status, and absence of distant metastases. Kaplan-Meier survival analysis demonstrated that patients with BAX mRNA-positive NPC have significantly longer disease-free survival (DFS) and overall survival (OS). In accordance with these findings, Cox regression analysis revealed that BAX mRNA expression can be considered as a favorable prognostic indicator of DFS and OS in NPC, independent of their gender, age, tumor histology, tumor extent, and nodal status. Furthermore, NPC patients without distant metastases are less likely to relapse when their primary tumor is BAX mRNA-positive, compared to metastasis-free patients with a BAX-negative nasopharyngeal malignancy. This is the first study examining the potential clinical utility of BAX as a prognostic tumor biomarker in NPC. We provide evidence that BAX mRNA expression can be considered as an independent favorable prognostic indicator of DFS and OS in NPC

  14. Enhancement of p53 gene transfer efficiency in hepatic tumor mediated by transferrin receptor through trans-arterial delivery.

    Science.gov (United States)

    Lu, Qin; Teng, Gao-Jun; Zhang, Yue; Niu, Huan-Zhang; Zhu, Guang-Yu; An, Yan-Li; Yu, Hui; Li, Guo-Zhao; Qiu, Ding-Hong; Wu, Chuan-Ging

    2008-02-01

    Transferrin-DNA complex mediated by transferrin receptor in combination with interventional trans-arterial injection into a target organ may be a duel-target-oriented delivery means to achieve an efficient gene therapy. In this study, transferrin receptor expression in normal human hepatocyte and two hepatocellular-carcinoma cells (Huh7/SK-Hep1) was determined. p53-LipofectAMINE with different amounts of transferrin was transfected into the cells and the gene transfection efficiency was evaluated. After VX2 rabbit hepatocarcinoma model was established, the transferrin-p53-LipofectAMINE complex was delivered into the hepatic artery via interventional techniques to analyze the therapeutic p53 gene transfer efficiency in vivo by Western blot, immunohistochemical/immunofluorescence staining analysis and survival time. The results were transferrin receptor expression in Huh7 and SK-Hep1 cells was higher than in normal hepatocyte. Transfection efficiency of p53 was increased in vitro in both Huh7 and SK-Hep1 cells with increasing transferrin in a dose-dependent manner. As compared to intravenous administration, interventional injection of p53-gene complex into hepatic tumor mediated by transferrin-receptor, could enhance the gene transfer efficiency in vivo as evaluated by Western blot, immunohistochemical/immunofluorenscence staining analyses and improved animal survival (H = 12.567, p = 0.0019). These findings show the transferrin-transferrin receptor system combined with interventional techniques enhanced p53-gene transfer to hepatic tumor and the duel-target-oriented gene delivery may be an effective approach for gene therapy. PMID:18347429

  15. Extended triplet set C343 of DNA sequences and its application to the p53 gene

    Institute of Scientific and Technical Information of China (English)

    Yan Yan-Yan; Zhu Ping

    2011-01-01

    Recently, much research has indicated that more and more cancers pose a threat to human life. Cancers are caused by oncogenes. Many human oncogenes have been found and most of them are located on chromosomes. The discovery of the oncogene plays a significant role in the treatment of cancer. The p53 tumor suppressor gene has received much attention because it frequently mutates or deletes in tumor cells of most people. Thus, the study of oncogenes is significant. In order to establish the Galois field (GF(7)), the indefinite gene is introduced as D and oncogene is introduced as O, and P. Taking the polynomial coefficients a0, a1, a2 ∈ GF(7) and the bijective function f: GF(7) → {D, A, C, O, G, T, P}, where f(0) = D, f(1) = A, f(2) = C, f(3) = O, f(4) = G, f(5) = T, and f(6) = P,the bijective (ψ) may be written as (ψ)(a0 + a1x + a2x2). Based on the algebraic structure, we can not only analyse the DNA sequence of oncogenes, but also predict possible new cancers.

  16. p53 gene therapy in combination with transcatheter arterial chemoembolization for HCC: One-year follow-up

    Institute of Scientific and Technical Information of China (English)

    Yong-Song Guan; Yuan Liu; Qing He; Xiao Li; Lin Yang; Ying Hu; Zi La

    2011-01-01

    the survival rates are significantly higher for p53 treatment group than for control group (P = 0.0002). CONCLUSION: The rAd-p53 gene therapy in combination with TACE is a safe and effective treatment modality for advanced HCC.

  17. 听神经瘤BCL-2蛋白及bcl-2/JH融合基因的研究☆%Detection of BCL-2 protooncogene protein expression and the related bcl-2(mbr)/JH fusion gene from archival paraffin-embedded tissue from acoustic neuromas.

    Institute of Scientific and Technical Information of China (English)

    刘绍明; 李龄; 刘鹏翀

    2001-01-01

    目的评价石蜡包埋听神经瘤组织中BGL-2蛋白表达及相关的bcl-2(mbr)/JH融合基因改变,以探讨bcl-2癌基因在听神经瘤发病中的可能意义.方法免疫组化检测石蜡包埋组织中BCL-2蛋白的表达;提取石蜡包埋组织的DNA,PCR检测bcl-2(mbr)/JH融合基因.结果本组40例听神经瘤,BCL-2蛋白表达阳性27例(67.5%),bcl-2(mbr)/JH融合基因检出阳性19例(47.5%).结论听神经瘤中存在BCL-2蛋白的高表达及t(14;18)染色体易位,提示雪旺氏细胞凋亡抑制可能是听神经瘤发病的分子病理基础之一.

  18. OTUD5 regulates p53 stability by deubiquitinating p53.

    Directory of Open Access Journals (Sweden)

    Judong Luo

    Full Text Available BACKGROUND: The p53 tumour suppressor protein is a transcription factor that prevents oncogenic progression by activating the expression of apoptosis and cell-cycle arrest genes in stressed cells. The stability of p53 is tightly regulated by ubiquitin-dependent degradation, driven mainly by its negative regulators ubiquitin ligase MDM2. PRINCIPAL FINDINGS: In this study, we have identified OTUD5 as a DUB that interacts with and deubiquitinates p53. OTUD5 forms a direct complex with p53 and controls level of ubiquitination. The function of OTUD5 is required to allow the rapid activation of p53-dependent transcription and a p53-dependent apoptosis in response to DNA damage stress. CONCLUSIONS: As a novel deubiquitinating enzyme for p53, OTUD5 is required for the stabilization and the activation of a p53 response.

  19. Expression and significance of p53, DCC and APC gene in colorectal carcinoma tissue%p53、DCC、APC在结直肠癌组织中的表达及其意义

    Institute of Scientific and Technical Information of China (English)

    田林; 田孝萍; 陈永宏

    2012-01-01

    Objective To investgate the expression and significance of p53,dreleted in colorectal cacinoma(DCC) and adenomatous polyposis coli(APC) gene in colorectal carcinoma.Methods The expression of p53,DCC and APC gene in colorectal cancer was examined by immunohistochemical technique.Results The expressions rate of p53,DCC and APC gene in colorectal carcinoma was 68%,27% and 52%.There was a positive correlation of the expression of DCC with APC gene (P < 0.05).There was no correlation between the expression of p53 and DCC gene,the expression of DCC and APC gene (P > 0.05).Conclusions The over expression of p53 and the reduced expression of DCC,APC gene was regarded as progonostic factors for colorectal cancers.Combined detection of p53,DCC and APC expression is useful in predicting the metastasis potential and prognosis of colorectal cancer.%目的 探讨p53、结直肠癌缺失基因(DCC)和腺瘤性息肉病基因(APC)三种抑癌基因在结直肠癌组织中的表达及其意义.方法 采用免疫组织化学方法检测p53、DCC和APC在结直肠癌中的表达.结果 结直肠癌中p53高表达,阳性率为68%;结直肠癌中DCC低表达,阳性率为27%;结直肠癌中APC低表达,阳性率为52%.应用检验的关联性分析,癌组织中的DCC基因的表达与APC基因表达呈正相关关系.结论 DCC的表达降低与APC的表达降低具有协同作用,p53、DCC和APC的多个基因表达的联合检测可能为判断结直肠癌恶性转化、临床病理过程及预后提供参考依据,具有一定的价值.

  20. Evaluation of Proliferative Index (Ki 67 and Suppressor Gene (P53 Expression in Colon Polyps

    Directory of Open Access Journals (Sweden)

    Mürüvvet Akçay Çelik

    2015-11-01

    Full Text Available Objective: The aim of this study is to evaluate the presence of Ki 67 proliferation zone of active areas and p53 mutation in colorectal polyps and to compare the results between the polyp types. Methods: Our study included 142 colon polyps. Studies based on the presence of dysplastic areas and dysmorphism in the polyp types that were considered to be non–neoplastic showed that a different pathway may have a role in malignant transformation. The cases were reclassified according to WHO 2010 classification. The tissue sections were stained by immunohistochemistry for Ki 67 and p53 Results: In our study Ki 67 staining was seen 74.5% in the lower zone of the crypt with HP. Ki 67 staining was seen in both the lower zone (40.9% and the upper zone (56.1% of the crypt with AP. In almost all cases, low rate of the p53 staining was observed in the ½ lower zone of crypts. The rate of p53 staining in the upper ½ zone of the crypts was 50% in AP cases. The staining ratio was low in HP and SSA/P Conclusion: The evaluation of polyp histopathology and Ki 67, p53, and molecular genetic with serologic characteristics of patients are required in parallel reviews.

  1. Transient transfection of a wild-type p53 gene triggers resveratrol-induced apoptosis in cancer cells.

    Science.gov (United States)

    Ferraz da Costa, Danielly Cristiny; Casanova, Fabiana Alves; Quarti, Julia; Malheiros, Maitê Santos; Sanches, Daniel; Dos Santos, Patricia Souza; Fialho, Eliane; Silva, Jerson L

    2012-01-01

    Resveratrol is a promising chemopreventive agent that mediates many cellular targets involved in cancer signaling pathways. p53 has been suggested to play a role in the anticancer properties of resveratrol. We investigated resveratrol-induced cytotoxicity in H1299 cells, which are non-small lung cancer cells that have a partial deletion of the gene that encodes the p53 protein. The results for H1299 cells were compared with those for three cell lines that constitutively express wild-type p53: breast cancer MCF-7, adenocarcinomic alveolar basal epithelia A549 and non-small lung cancer H460. Cell viability assays revealed that resveratrol reduced the viability of all four of these cell lines in a dose- and time-dependent manner. MCF-7, A549 and H460 cells were more sensitive to resveratrol than were H1299 cells when exposed to the drug for 24 h at concentrations above 100 µM. Resveratrol also increased the p53 protein levels in MCF-7 cells without altering the p53 mRNA levels, suggesting a post-translational modulation of the protein. The resveratrol-induced cytotoxicity in these cells was partially mediated by p53 and involved the activation of caspases 9 and 7 and the cleavage of PARP. In H1299 cells, resveratrol-induced cytotoxicity was less pronounced and (in contrast to MCF-7 cells) cell death was not accompanied by caspase activation. These findings are consistent with the observation that MCF-7 cells were positively labeled by TUNEL following exposure to 100 µM resveratrol whereas H1299 cells under similar conditions were not labeled by TUNEL. The transient transfection of a wild-type p53-GFP gene caused H1299 cells to become more responsive to the pro-apoptotic properties of resveratrol, similarly to findings in the p53-positive MCF-7 cells. Our results suggest a possible therapeutic strategy based on the use of resveratrol for the treatment of tumors that are typically unresponsive to conventional therapies because of the loss of normal p53 function. PMID

  2. Transient transfection of a wild-type p53 gene triggers resveratrol-induced apoptosis in cancer cells.

    Directory of Open Access Journals (Sweden)

    Danielly Cristiny Ferraz da Costa

    Full Text Available Resveratrol is a promising chemopreventive agent that mediates many cellular targets involved in cancer signaling pathways. p53 has been suggested to play a role in the anticancer properties of resveratrol. We investigated resveratrol-induced cytotoxicity in H1299 cells, which are non-small lung cancer cells that have a partial deletion of the gene that encodes the p53 protein. The results for H1299 cells were compared with those for three cell lines that constitutively express wild-type p53: breast cancer MCF-7, adenocarcinomic alveolar basal epithelia A549 and non-small lung cancer H460. Cell viability assays revealed that resveratrol reduced the viability of all four of these cell lines in a dose- and time-dependent manner. MCF-7, A549 and H460 cells were more sensitive to resveratrol than were H1299 cells when exposed to the drug for 24 h at concentrations above 100 µM. Resveratrol also increased the p53 protein levels in MCF-7 cells without altering the p53 mRNA levels, suggesting a post-translational modulation of the protein. The resveratrol-induced cytotoxicity in these cells was partially mediated by p53 and involved the activation of caspases 9 and 7 and the cleavage of PARP. In H1299 cells, resveratrol-induced cytotoxicity was less pronounced and (in contrast to MCF-7 cells cell death was not accompanied by caspase activation. These findings are consistent with the observation that MCF-7 cells were positively labeled by TUNEL following exposure to 100 µM resveratrol whereas H1299 cells under similar conditions were not labeled by TUNEL. The transient transfection of a wild-type p53-GFP gene caused H1299 cells to become more responsive to the pro-apoptotic properties of resveratrol, similarly to findings in the p53-positive MCF-7 cells. Our results suggest a possible therapeutic strategy based on the use of resveratrol for the treatment of tumors that are typically unresponsive to conventional therapies because of the loss of normal

  3. BCL-6、MYC和p53基因异常与弥漫性大B细胞淋巴瘤免疫学亚型及预后的关系%Correlation of BCL-6, MYC and p53 gene abnormalities with immunological subtypes and prognosis of diffuse large B-cell lymphoma

    Institute of Scientific and Technical Information of China (English)

    孙冠星; 曹祥山; 李青; 王志林

    2012-01-01

    目的 探讨弥漫性大B细胞淋巴瘤(diffuse large B-cell lymphoma,DLBCL)患者BCL-6、MYC和p53基因的异常情况,用并分析它们与免疫学亚型及预后的关系.方法 应用间期荧光原位杂交技术分析46例DLBCL患者BCL-6、MYC和p53基因的异常情况,用免疫组织化学技术(Envision法)对DLBCL进行CD3、CD10、CD20、BCL-6、MUM-1、BCL-2和Ki-67标记,根据Hans的分类方法将其分为生发中心B细胞型(germinal center B cell,GCB型)和非生发中心B细胞型(non-germinal center B cell,non-GCB型).结果 46例患者中,BCL-6基因重排10例,BCL-6重排与BCL-6蛋白的表达两者之间差异无统计学意义(P=0.245).BCL-6基因重排与DLBCL患者的总生存时间(P=0.138)和无进展生存时间(P=0.095)无统计学相关性.MYC重排4例,全部见于GCB型.p53基因缺失14例,p53基因缺失组与p53基因正常组相比,生存时间差异有统计学意义(总生存时间:P=0.046;无进展生存时间::P=0.043).结论 间期荧光原位杂交技术可以快速、准确、灵敏的检测BCL-6、MYC和p53基因的异常.BCL-6基因重排与BCL-6蛋白的表达之间无统计学相关性.MYC重排多见于GCB亚型组,p53基因缺失的患者预后较差.p53基因可以作为判断DLBCL预后的参考指标.%Objective To investigate BCL-6,MYC and p53 genes abnormalities in diffuse large B-cell lymphoma (DLBCL) and correlate the result with immunosubtypes and prognosis.Methods Interphase fluorescence in situ hybridization (I-FISH) was performed to detect the BCL-6,MYC and p53 genes.Immunohistochemistry (Envision method) was used to measure the expressions of CD3,CD10,CD20,BCL-6,MUM-1,BCL-2 and Ki-67 genes in DLBCL.The patients were classified into germinal center B cell-like (GCB) and non-GCB subtypes according to Hans' algorithm.Results BCL-6 rearrangement was detected in 10 of 46 DLBCL cases.The presence of gene rearrangement had no correlation with BCL-6 protein expression (P=0.245).Overall survival (OS,P=0

  4. ISG20L1 is a p53 family target gene that modulates genotoxic stress-induced autophagy

    Directory of Open Access Journals (Sweden)

    Johnson Kimberly N

    2010-04-01

    Full Text Available Abstract Background Autophagy is characterized by the sequestration of cytoplasm and organelles into multimembrane vesicles and subsequent degradation by the cell's lysosomal system. It is linked to many physiological functions in human cells including stress response, protein degradation, organelle turnover, caspase-independent cell death and tumor suppression. Malignant transformation is frequently associated with deregulation of autophagy and several tumor suppressors can modulate autophagic processes. The tumor suppressor p53 can induce autophagy after metabolic or genotoxic stress through transcriptionally-dependent and -independent mechanisms. In this study we expand on the former mechanism by functionally characterizing a p53 family target gene, ISG20L1 under conditions of genotoxic stress. Results We identified a p53 target gene, ISG20L1, and show that transcription of the gene can be regulated by all three p53 family members (p53, p63, and p73. We generated an antibody to ISG20L1 and found that it localizes to the nucleolar and perinucleolar regions of the nucleus and its protein levels increase in a p53- and p73-dependent manner after various forms of genotoxic stress. When ectopically expressed in epithelial cancer-derived cell lines, ISG20L1 expression decreased clonogenic survival without a concomitant elevation in apoptosis and this effect was partially rescued in cells that were ATG5 deficient. Knockdown of ISG20L1 did not alter 5-FU induced apoptosis as assessed by PARP and caspase-3 cleavage, sub-G1 content, and DNA laddering. Thus, we investigated the role of ISG20L1 in autophagy, a process commonly associated with type II cell death, and found that ISG20L1 knockdown decreased levels of autophagic vacuoles and LC3-II after genotoxic stress as assessed by electron microscopy, biochemical, and immunohistochemical measurements of LC3-II. Conclusions Our identification of ISG20L1 as a p53 family target and discovery that modulation

  5. PCR-RFLP to Detect Codon 248 Mutation in Exon 7 of "p53" Tumor Suppressor Gene

    Science.gov (United States)

    Ouyang, Liming; Ge, Chongtao; Wu, Haizhen; Li, Suxia; Zhang, Huizhan

    2009-01-01

    Individual genome DNA was extracted fast from oral swab and followed up with PCR specific for codon 248 of "p53" tumor suppressor gene. "Msp"I restriction mapping showed the G-C mutation in codon 248, which closely relates to cancer susceptibility. Students learn the concepts, detection techniques, and research significance of point mutations or…

  6. Absence of p53 gene mutations in mice colon pre-cancerous stage induced by o-nitrotoluene

    Directory of Open Access Journals (Sweden)

    Nahed A Hussien

    2014-01-01

    Conclusion: The results from the present study indicate that point mutations in the p53 gene, in the coding region (exons 5-8 and outside it (exons 10, 11, are not involved in the development of the colon precancerous stage induced by o-nt in mice.

  7. p53基因启动子转录活性检测细胞模型的建立%Establishment of Cell Model for Determining Transcriptive Activity of p53 Gene Promoter

    Institute of Scientific and Technical Information of China (English)

    秦红芳; 曾玲; 陈静; 白晔; 李菲; 黄开远; 温泉; 赖宝玲; 陈东风

    2013-01-01

    [目的]构建p53基因启动子靶控报告基因细胞模型,为高通量筛选出以p53为靶标的中药提供新的细胞模型.[方法]采用瞬时转染报告基因测定法,确定最佳转染方案及p53基因启动子转录活性细胞模型的建立和验证,观察p53抑制剂PFT-a、血清饥饿、过氧化氢、自噬激活剂雷帕霉素对p53基因启动子转录活性PC12细胞模型的量效和时效关系.[结果]PFI-α诱导3h,对p53基因启动子转录活性抑制率达50%左右;血清饥饿诱导12、24、36 h,p53基因启动子转录活性是对照组的1.6倍;过氧化氢300μmol/L诱导9h,p53基因启动子转录活性是对照组的1.3倍;雷帕霉素在浓度为0.1、1 nmol/L可上调p53基因启动子转录活性,呈浓度依赖性,而5 nmol/L及更高浓度可下调p53基因启动子转录活性.[结论]成功建立采用p53基因启动子报告基因检测p53基因启动子转录活性的特异性细胞模型,血清饥饿、过氧化氢、雷帕霉素可诱导p53基因启动子的转录活性.%Objective PC12 cell model with p53 gene promoter target-controlled reporter gene was constructed for the establishment of cell model to screen p53-targeted Chinese herbal medicine. Methods By transient transfection of p53 promoter reporter gene, we optimized the transfection procedure, and established the PC 12 cell model for determining the transcriptive activity of p53 gene promoter. After establishing the cell model, we investigated the dose-effect and time-effect relationship of transcriptive activity of p53 with p53 inhibitor PFT-a, serum starvation, hydrogen peroxide, and autophagic activator rapamycin. Results Compared with the control group, the inhibition ratio of transcriptional activity of p53 gene promoter was about 50% after induction with PFT-a for 3 hours. After serum starvation for 12, 24 and 36 hours, the transcriptional activity was 1. 6 times as much as that of the control group, but the transcriptional activity was

  8. p53 isoforms change p53 paradigm

    OpenAIRE

    Bourdon, JC

    2014-01-01

    Although p53 defines cellular responses to cancer treatment it is not clear how p53 can be used to control cell fate outcome. Data demonstrate that so-called p53 does not exist as a single protein, but is in fact a group of p53 protein isoforms whose expression can be manipulated to control the cellular response to treatment.

  9. Simultaneous gene silencing of Bcl-2, XIAP and Survivin re-sensitizes pancreatic cancer cells towards apoptosis

    International Nuclear Information System (INIS)

    Pancreatic ductal adenocarcinoma shows a distinct apoptosis resistance, which contributes significantly to the aggressive nature of this tumor and constrains the effectiveness of new therapeutic strategies. Apoptosis resistance is determined by the net balance of the cells pro-and anti-apoptotic 'control mechanisms'. Numerous dysregulated anti-apoptotic genes have been identified in pancreatic cancer and seem to contribute to the high anti-apoptotic buffering capacity. We aimed to compare the benefit of simultaneous gene silencing (SGS) of several candidate genes with conventional gene silencing of single genes. From literature search we identified the anti-apoptotic genes XIAP, Survivin and Bcl-2 as commonly upregulated in pancreatic cancer. We performed SGS and silencing of single candidate genes using siRNA molecules in two pancreatic cancer cell lines. Effectiveness of SGS was assessed by qRT-PCR and western blotting. Apoptosis induction was measured by flow cytometry and caspase activation. Simultaneous gene silencing reduced expression of the three target genes effectively. Compared to silencing of a single target or control, SGS of these genes resulted in a significant higher induction of apoptosis in pancreatic cancer cells. In the present study we performed a subliminal silencing of different anti-apoptotic target genes simultaneously. Compared to silencing of single target genes, SGS had a significant higher impact on apoptosis induction in pancreatic cancer cells. Thereby, we give further evidence for the concept of an anti-apoptotic buffering capacity of pancreatic cancer cells

  10. Mitochondrial dysfunction and transactivation of p53-dependent apoptotic genes in BaP-treated human fetal lung fibroblasts.

    Science.gov (United States)

    Yang, Guangtao; Jiang, Ying; Rao, Kaimin; Chen, Xi; Wang, Qian; Liu, Ailin; Xiong, Wei; Yuan, Jing

    2011-12-01

    Benzo(a)pyrene (BaP) has been shown to be an inducer of apoptosis. However, mechanisms involved in BaP-induced mitochondrial dysfunction are not well-known. In this study, human fetal lung fibroblasts cells were treated with BaP (8, 16, 32, 64 and 128 μM) for 4 and 12 h. Cell viability, intracellular level of reactive oxygen species (ROS), total antioxidant capacity (T-AOC), mitochondrial membrane potential (ΔΨ(m)) and cytochrome c release were determined. Changes in transcriptional levels of p53-dependent apoptotic genes (p53, APAF1, CASPASE3, CASPASE9, NOXA and PUMA) were measured. At time point of 4 h, BaP induced the intracellular ROS generation in 64 (p BaP groups (p BaP groups (p BaP groups (p BaP group (p BaP groups (p BaP group a relatively little expression of p53 mRNA was observed (p BaP promoted the generation of excessive ROS and subsequently the mitochondrial depolarization, whereas transactivations of the p53-dependent apoptotic genes were significantly induced at the later period.

  11. Analysis of loss of heterozygosity of the tumor suppressor genes p53 and BRCA1 in ovarial carcinomas

    Directory of Open Access Journals (Sweden)

    Luković Ljiljana

    2006-01-01

    Full Text Available Background/aim: Among the genes involved in ovarian carcinogenesis, there has been increased interest in tumor-suppressor genes p53 and BRCA1. Both of the genes make control of cell cycle, DNA repair and apoptosis. The p53 is a "genome guardian" inactivated in more than 50% of human cancers, while BRCA1 mutations are found mostly in breast and ovarian cancer. The aim of this investigation was to establish the frequency of loss of heterozygosity (LOH in the regions of the genes p53 and BRCA1 in ovarian carcinomas, and to analyze the association of LOH with the disease stage and prognosis. Methods. We analyzed 20 patients with a confirmed diagnosis of epithelilal ovarian carcinoma. DNA for molecular-genetic analysis was extracted from the tumor tissue and blood as normal tissue of each person. Microsatellite markers of the regions of genes p53 and BRCA1 were amplified by PCR method. The determination of allelic status of microsatellites and detection of LOH was performed after PAA gel electroforesis. Results. Both of the analyzed microsatellite markers were informative in 13/20 (65% cases. In the region of gene p53, LOH was established in 4/13 (30.7% tumors. One of them had histological gradus G1, one had gradus G2, and two of them had gradus G3, while all were with the International Federation of Gynecology and Obstetrics (FIGO IIIc stage. In the region of gene BRCA1, LOH was detected in 5/13 (38.5% tumors. Four of them had histological gradus G2, and one had gradus G3, while by the (FIGO classification one was with stage Ib, one was with stage IIIb, while the three were with stage IIIc. LOH in both of the analyzed regions was detected in one tumor (7.7%, with histological gradus G3 and the FIGO IIIc stage. Conclusion. The frequency of LOH in epthelial ovarian carcinomas was 30.7% and 38.5% for p53 and BRCA1 gene regions, respectively. Most of tumors with LOH had histological gradus G2 or G3, and the clinical FIGO stage IIIc, suggesting the

  12. P53 gene mutations and risk factors in Egyptian laryngeal cancer patients

    International Nuclear Information System (INIS)

    Laryngeal cancer (LC) is one of the most fatal cancers in the world; it represents the sixth most common cancer in the world and the second most common respiratory cancer, with approximately 500,000 new cases worldwide, annually. The mechanisms of tumorigenesis in LC remain unknown, although smoking and alcohol consumption are considered to be major risk factors. Numerous genetic alterations have been described in laryngeal squamous cell carcinoma, but the molecular mechanisms contributing to initiation and progression of laryngeal are still poorly understood. Mutations within P53 have been strongly implicated as frequent events in several cancers. In the present study, exons 5-8 of P53 for mutations in DNA from tumor biopsies (n 50), beside 20 samples of normal tissues adjacent to the malignant area, blood samples (n = 25) from the LC patients, and blood samples from a healthy, matched control group (n = 20), were screened using polymerase chain reaction, single-strand conformation polymorphism (PCR-SSCP) analysis and direct sequencing was done . Significant positive correlations were found between the occurrence of LC and age and smoking. In tumor-derived samples, mutations were found in three of the exons under investigation, representing 18 % of the samples. The mutations were unique to the tumor biopsies, indicating a somatic origin for mutations. The data confirm that the exons 6-8 of P53 is a mutational hotspot for laryngeal cancers in Egypt; ten mutations were found within this region.

  13. MYC/BCL2 protein coexpression contributes to the inferior survival of activated B-cell subtype of diffuse large B-cell lymphoma and demonstrates high-risk gene expression signatures

    DEFF Research Database (Denmark)

    Hu, Shimin; Xu-Monette, Zijun Y; Tzankov, Alexander;

    2013-01-01

    , cyclophosphamide, doxorubicin, vincristine, and prednisone). We show that MYC/BCL2 protein coexpression occurred significantly more commonly in the ABC subtype. Patients with the ABC or GCB subtype of DLBCL had similar prognoses with MYC/BCL2 coexpression and without MYC/BCL2 coexpression. Consistent...... with the notion that the prognostic difference between the 2 subtypes is attributable to MYC/BCL2 coexpression, there is no difference in gene expression signatures between the 2 subtypes in the absence of MYC/BCL2 coexpression. DLBCL with MYC/BCL2 coexpression demonstrated a signature of marked downregulation...... of genes encoding extracellular matrix proteins, those involving matrix deposition/remodeling and cell adhesion, and upregulation of proliferation-associated genes. We conclude that MYC/BCL2 coexpression in DLBCL is associated with an aggressive clinical course, is more common in the ABC subtype...

  14. Spectrum of p53 gene mutations suggests a possible role for ultraviolet radiation in the pathogenesis of advanced cutaneous lymphomas.

    Science.gov (United States)

    McGregor, J M; Crook, T; Fraser-Andrews, E A; Rozycka, M; Crossland, S; Brooks, L; Whittaker, S J

    1999-03-01

    There is evidence that the incidence of primary cutaneous lymphoma, like other forms of non-Hodgkin's lymphoma, is increasing, yet little is known of the pathogenetic events involved in this group of disorders. In this study we examine the frequency and spectrum of P53 gene mutations in a large series of primary cutaneous lymphomas, with particular emphasis on tumor stage mycosis fungoides, as it is in these cases that p53 overexpression has previously been reported. Sixty-six samples from 55 patients with primary cutaneous B cell and T cell lymphomas were analyzed for mutations in exons 5-9 of the P53 gene using polymerase chain reaction/single strand conformational polymorphism, and subsequent cloning and sequencing of genomic DNA. Fourteen separate P53 mutations were identified in blood, skin, and lymph node samples in 13 patients (24%). Twelve of 14 mutations occurred at dipyrimidine sites, eight resulting in C-->T transitions and one in a CC-->TT tandem base transition, a mutation spectrum strikingly similar to that reported in nonmelanoma skin cancer and characteristic of DNA damage caused by ultraviolet B radiation. In the subset of patients with mycosis fungoides, P53 mutations were identified in six of 17 patients with tumor-stage but in none of 12 patients with plaque-stage disease (Fisher's exact test p = 0.027). These data suggest a role for ultraviolet radiation in the pathogenesis of primary cutaneous lymphomas and a possible ultraviolet B-related step in the progression of mycosis fungoides from plaque to tumor-stage disease.

  15. Somatic mutation analysis of p53 and ST7 tumor suppressor genes in gastric carcinoma by DHPLC

    Institute of Scientific and Technical Information of China (English)

    Chong Lu; Hui-Mian Xu; Qun Ren; Yang Ao; Zhen-Ning Wang; Xue Ao; Li Jiang; Yang Luo; Xue Zhang

    2003-01-01

    AIM: To verify the effectiveness of denaturing highperformance liquid chromatography (DHPLC) in detecting somatic mutation of p53 gene in gastric carcinoma tissues.The superiority of this method has been proved in the detection of germline mutations, but it was not very affirmative with respect to somatic mutations in tumor specimens. ST7 gene, a candidate tumor suppressor gene identified recently at human chromosome 7q31.1, was also detected because LOH at this site has also been widely reported in stomach cancer.METHODS: DNA was extracted from 39 cases of surgical gastric carcinoma specimen and their correspondent normal mucosa. Seven fragments spanning the 11 exons were used to detect the mutation of p53 gene and the four exons reported to have mutations in ST7 gene were amplified by PCR and directly analyzed by DHPLC without mixing with wild-type allele.RESULTS: In the analysis of p53 gene mutation, 9 aberrant DHPLC chromatographies were found in tumor tissues, while their normal-adjacent counterparts running in parallel showed a normal shape. Subsequent sequencing revealed nine sequence variations, 1 polymorphism and 8 mutations including 3 mutations not reported before. The mutation rate of p53 gene (21%) was consistent with that previously reported. Furthermore, no additional aberrant chromatography was found when wild-type DNA was added into the DNA of other 30 tumor samples that showed normal shapes previously. The positivity of p53 mutations was significantly higher in intestinal-type carcinomas (40 %) than that in diffuse-type (8.33 %) carcinomas of the stomach. No mutation of ST7 gene was found.CONCLUSION: DHPLC is a very convenient method for the detection of somatic mutations in gastric carcinoma. The amount of wild type alleles supplied by the non-tumorous cells in gastric tumor specimens is enough to form heteroduplex with mutant alleles for DHPLC detection. ST7 gene may not be the target gene of inactivation at 7q31 site in gastric carcinoma.

  16. 人类p53和c-myc同源基因在玉米颖果发育过程中的表达%Expressions of Human p53 and c-myc Gene Homologues During Caryopsis Development in Maize

    Institute of Scientific and Technical Information of China (English)

    亓翠英; 宁顺斌; 王宁; 李立家; 宋运淳

    2003-01-01

    肿瘤抑制基因p53和原癌基因c-myc已被证明在动物中高度保守并参与许多PCD过程.这两个基因编码的同源蛋白及其RNA在玉米中的存在已有报道,并且其DNA同源序列已利用荧光原位杂交定位在玉米相应的染色体上.利用免疫组织化学方法探测了与人类p53和c-myc基因同源的玉米基因在玉米颖果发育过程中的时空表达模式.结果发现,在授粉后的一定阶段,在反足细胞、珠被、未成熟的胚乳、子房壁、导管组织和糊粉层中,p53同源基因表达强烈,c-myc同源基因的表达相反,在授粉后的这些组织中基本不表达,而在授粉前的中央细胞的极核中表达水平较高.TUNEL检测显示,在p53同源基因呈现高水平表达的地方,DNA断裂信号强烈.在动物细胞中,p53和c-myc起相反的调节作用,这与其同源基因在玉米中的作用模式相似.由此说明p53和c-myc同源基因可能在玉米颖果发育PCD过程中起重要作用,并进一步推论高等植物PCD和动物细胞凋亡存在一定的保守性机制.%Tumor suppressor gene p53 and proto-oncogene c-myc have been proved to be highly conserved and participate in many PCD processes in animals.In maize,proteins and RNAs related to p53 and c-myc have already been reported and the sequences homologous to these two genes have also been localized onto maize chromosomes by FISH.In this study,using immunohistochemistry we investigated the expression patterns of maize genes homologous to human p53 and c-myc during caryopsis development stages in maize.In a giving stage after pollination,p53 homologue showed high levels in the antipodal cells,integument,immature endosperm,ovary wall,tracheary elements,and aleurone layer,while c-myc homologue showed low levels in these tissues,only before pollination showed high expression in polar nucleus.The results of TUNEL assay demonstrated that TUNEL positive signals were detected where p53 homologue showed high expression

  17. MYC translocation partner gene determines survival of patients with large B-cell lymphoma with MYC- or double-hit MYC/BCL2 translocations

    DEFF Research Database (Denmark)

    Pedersen, Mette Ø; Gang, Anne O; Poulsen, Tim S;

    2014-01-01

    In large B-cell lymphoma (LBCL) MYC- and MYC/BCL2 double-hit (DH) translocations have been associated with inferior survival. We hypothesised that the negative prognostic impact of MYC translocation was determined by an immunoglobulin MYC translocation partner gene (IG-MYC), as opposed to a non......-immunoglobulin partner gene (nonIG-MYC). In a prospective, unselected cohort of 237 LBCL patients MYC and BCL2 translocations were identified by fluorescent in situ hybridisation (FISH) with split probes. MYC translocation partner gene was identified by IGH/MYC fusion probes and/or kappa/lambda split probes. Clinical...

  18. Honokiol induces apoptosis through p53-independent pathway in human colorectal cell line RKO

    Institute of Scientific and Technical Information of China (English)

    Tao Wang; Fei Chen; Zhe Chen; Yi-Feng Wu; Xiao-Li Xu; Shu Zheng; Xun Hu

    2004-01-01

    AIM: To investigate the signal pathway of honokiol-induced apoptosis on human colorectal carcinoma RKO cells and to evaluate whether p53 and p53-related genes were involved in honokiol-treated RKO cells.METHODS: Cell cycle distribution and subdiploid peak were analyzed with a flow cytometer and DNA fragment with electrophoresis on agarose gels. Transcriptional level of Bax, Bcl-2, Bid and Bcl-xl was accessed by RT-PCR.Western blotting was used to measure p53 protein expression and other factors related to apoptosis.Proliferation inhibition of two cell lines (RKO, SW480) with high expression of p53 and one cell line with p53 negative expression (LS180) was monitored by MTT assay.RESULTS: Honokiol induced RKO cell apoptosis in a dosedependent manner. The mRNA expression level and protein level of Bid were up-regulated while that of Bcl-xl was down-regulated, but no changes in Bax and Bcl-2 were observed. Western blotting showed p53 expression had no remarkable changes in honokiol-induced RKO cell apoptosis. LS180 cells treated with honokiol exhibited apparent growth inhibition like RKO cells and Sw480 cells.CONCLUSION: Honokiol can induce RKO cells apoptosis through activating caspase cascade by p53-indepenent pathway.

  19. Clinicopathology, immunophenotype, T cell receptor gene rearrangement, Epstein-Barr virus status and p53 gene mutation of cutaneous extranodal NK/T-cell lymphoma, nasal-type

    Institute of Scientific and Technical Information of China (English)

    WANG Ting-ting; XU Chen; LIU Shan-ling; KAN Bei; RAN Yu-ping; LIU Wei-ping; LI Gan-di

    2013-01-01

    Background Extranodal natural killer/T-cell (NK/T cell) lymphoma,nasal-type,is a rare lymphoma.Skin is the second most common site of involvement after the nasal cavity/nasalpharynx.The aim of this study was to investigate the clinicopathologic features,immunophenotype,T cell receptor (TCR) gene rearrangement,the association with Epstein-Barr virus (EBV) infection and p53 gene mutations of the lymphoma.Methods The clinicopathologic analysis,immunohistochemistry,in situ hybridization for EBER1/2,TCR gene rearrangement by polymerase chain reaction (PCR),mutations of p53 gene analyzed by PCR and sequence analysis were employed in this study.Results In the 19 cases,the tumor primarily involved the dermis and subcutaneous layer.Immunohistochemical staining showed that most of the cases expressed CD45RO,CD56,CD3ε,TIA-1 and GrB.Three cases were positive for CD3 and two cases were positive for CD30.Monoclonal TCRY gene rearrangement was found in 7 of 18 cases.The positive rate of EBER1/2 was 100%.No p53 gene mutation was detected on the exon 4-9 in the 18 cases.Fifteen cases showed Pro (proline)/Arg (arginine) single nucleotide polymorphisms (SNPs) on the exon 4 at codon 72.The expression of p53 protein was 72% (13/18) immunohistochemically.Conclusions Cutaneous NK/T-cell lymphoma is a rare but highly aggressive lymphoma with poor prognosis.No p53 gene mutation was detected on the exon 4-9,and Pro/Arg SNPs on p53 codon 72 were detected in the cutaneous NK/T-cell lymphoma.The overexpression of p53 protein may not be the result of p53 gene mutation.

  20. 贲门癌端粒酶活性表达及与p53基因突变关系的研究%Relationship of telomerase activity and p53 gene mutation in cardiac cancer

    Institute of Scientific and Technical Information of China (English)

    Jingruo li; Mengquan li; Jiangtao Li; Juntao Bao; Yunhang Zhang

    2007-01-01

    Objective: To study the relationship of the telomerase activity and the p53 gene mutation in cardiac cancer.Methods: Telomerase activity and the p53 gene mutation were detected in 46 case of cardiac cancer, peri-cancerous and 30 case of normal mucosa by TRAP-ELISA and PCR-SSCP. Results: The rate of expression of telomerase activity in cardiac cancer, peri-cancerous and normal mucosa were 82.61% (38/46), 43.48% (20/46) and 13.33% (4/30) respectively. The rate of Exon5→8 of p53 gene mutation were 39.13% (18/46), 4.35% (2/46) and 0.00% respectively. There was significant differ ence between group cancer and without cancer (P < 0.01). Mean of (A) value of telomerase is 1.89 ± 0.41 in cancer group and were 1.49 ± 0.43, 0.54 ± 0.45 respectively in peri-canvcerous and normal mucosa, there were significant differences in cancer group and group of without cancer (P < 0.05). The rate of p53 gene mutations in group of expression of telomerase activity was 44.74% (17/38), and 12.50% (1/8) in without expression of telomerase activity. There were significant differences between the two groups. Conclusion: The rate of expression of telomerase activity and mean of (A) value of telomerase in cardiac cancer were obviously higher than without cancer, which indicating telomerase activity was closely related with the occurrence of cardiac cancer. P53 gene mutation in cardiac cancer were higher than the tissue of without cancer, and the rate of p53 gene mutation in telomerase activity were obviously higher than the group of without cancer. This shows the p53 gene mutation can loss of function of suppressing cancer and prompt telomerase activity and cause the cardiac cancer.

  1. p53 and its isoforms in cancer

    OpenAIRE

    Bourdon, J-C

    2007-01-01

    p53, p63 and p73 are members of the p53 gene family involved in development, differentiation and response to cellular stress. p53 gene is a transcription factor essential for the prevention of cancer formation. The p53 pathway is ubiquitously lost in human cancer either by p53 gene mutation (60% of cancers) or by lost of cell signalling upstream and downstream of p53 in the remaining cancers expressing WTp53 gene. As p53 pathway inactivation is a common denominator to all cancers, the underst...

  2. The P53R2 Gene involved in a P53-dependent Cell-cycle Checkpoint for DNA Damage%依赖P53P53R2基因在细胞周期检验点对损伤DNA的修复作用

    Institute of Scientific and Technical Information of China (English)

    张伟; 明镇寰

    2001-01-01

    @@1. p53基因及P53蛋白p53基因最初被认为是一个普通的癌基因,其产物的作用是刺激肿瘤细胞的生长。但后来发现原先研究的p53基因只是野生型p53基因的突变体,只有突变型p53基因的产物才能刺激不正常细胞(如癌细胞)的生长,而野生型p53基因的产物对肿瘤则有抑制作用,正常的p53基因原来是一个抑癌基因。经长期研究发现,突变型p53基因在人

  3. Activation of endogenous p53 by combined p19Arf gene transfer and nutlin-3 drug treatment modalities in the murine cell lines B16 and C6

    International Nuclear Information System (INIS)

    Reactivation of p53 by either gene transfer or pharmacologic approaches may compensate for loss of p19Arf or excess mdm2 expression, common events in melanoma and glioma. In our previous work, we constructed the pCLPG retroviral vector where transgene expression is controlled by p53 through a p53-responsive promoter. The use of this vector to introduce p19Arf into tumor cells that harbor p53wt should yield viral expression of p19Arf which, in turn, would activate the endogenous p53 and result in enhanced vector expression and tumor suppression. Since nutlin-3 can activate p53 by blocking its interaction with mdm2, we explored the possibility that the combination of p19Arf gene transfer and nutlin-3 drug treatment may provide an additive benefit in stimulating p53 function. B16 (mouse melanoma) and C6 (rat glioma) cell lines, which harbor p53wt, were transduced with pCLPGp19 and these were additionally treated with nutlin-3 or the DNA damaging agent, doxorubicin. Viral expression was confirmed by Western, Northern and immunofluorescence assays. p53 function was assessed by reporter gene activity provided by a p53-responsive construct. Alterations in proliferation and viability were measured by colony formation, growth curve, cell cycle and MTT assays. In an animal model, B16 cells were treated with the pCLPGp19 virus and/or drugs before subcutaneous injection in C57BL/6 mice, observation of tumor progression and histopathologic analyses. Here we show that the functional activation of endogenous p53wt in B16 was particularly challenging, but accomplished when combined gene transfer and drug treatments were applied, resulting in increased transactivation by p53, marked cell cycle alteration and reduced viability in culture. In an animal model, B16 cells treated with both p19Arf and nutlin-3 yielded increased necrosis and decreased BrdU marking. In comparison, C6 cells were quite susceptible to either treatment, yet p53 was further activated by the combination of p19

  4. Mutant p53 uses p63 as a molecular chaperone to alter gene expression and induce a pro-invasive secretome

    OpenAIRE

    Paul M. Neilsen; Noll, Jacqueline E.; Suetani, Rachel J; Schulz, Renee B.; Al-Ejeh, Fares; Evdokiou, Andreas; Lane, David P; David F. Callen

    2011-01-01

    Mutations in the TP53 gene commonly result in the expression of a full-length protein that drives cancer cell invasion and metastasis. Herein, we have deciphered the global landscape of transcriptional regulation by mutant p53 through the application of a panel of isogenic H1299 derivatives with inducible expression of several common cancer-associated p53 mutants. We found that the ability of mutant p53 to alter the transcriptional profile of cancer cells is remarkably conserved across differ...

  5. The Influence of Nano-apatite on c-myc and p53 Gene in the Hepatocellular Carcinoma

    Institute of Scientific and Technical Information of China (English)

    CHEN Jun; CAO Xianying; LI Shipu; HAN Yingchao; ZHANG Ran

    2005-01-01

    The influence mechanism of the nano-apatite on the human hepatocellular carcinoma in vitro was investigated. Using the homogeneous precipitation method, the nano-apatite was synthesized at room temperature, and it was characterized with transmission electron microscopy (TEM) and the Zataplus. The influence on the expression of the c-myc and p53 gene in the human hepatocellular carcinoma cell lines were tested with the TEM and hybridization in situ. The TEM and the Zataplus analyses show that the nano-apatite is distributed homogenously in size and needle-shaped sizes, which ranges from 67.5 nm to 88.3 nm. It is found that the nano-apatitet increases the volume of the human hepatocellular carcinoma cells, makes extensive cytoplasmic vacuolization, the mitochondria swelling, chromatin in nucleus dispersed partially and condensed around the nuclear membranes.The interspace in nuclear membranes were separated and even the cytoplasm dissolved. It is also found that the expression of the c-myc gene is inhibited, but the p53 is enhanced. The experimental results demonstrate that the nano-apatite enables the oncosis of the human hepatocellular carcinoma cells by down-regulation of the expression of the c-myc and up-regulation of the expression of the p53 in vitro.

  6. Resveratrol Reverses Cadmium Chloride-induced Testicular Damage and Subfertility by Downregulating p53 and Bax and Upregulating Gonadotropins and Bcl-2 gene Expression

    OpenAIRE

    Eleawa, Samy M.; ALKHATEEB, Mahmoud A; ALHASHEM, Fahaid H; BIN-JALIAH, Ismaeel; SAKR, Hussein F; ELREFAEY, Hesham M; ELKARIB, Abbas O; ALESSA, Riyad M; HAIDARA, Mohammad A; Shatoor, Abdullah S.; KHALIL, Mohammad A

    2014-01-01

    This study was performed to investigate the protective and therapeutic effects of resveratrol (RES) against CdCl2-induced toxicity in rat testes. Seven experimental groups of adult male rats were formulated as follows: A) controls+NS, B) control+vehicle (saline solution of hydroxypropyl cyclodextrin), C) RES treated, D) CdCl2+NS, E) CdCl2+vehicle, F) RES followed by CdCl2 and M) CdCl2 followed by RES. At the end of the protocol, serum levels of FSH, LH and testosterone were measured in all gr...

  7. P53 GENE MUTATIONS IN NON-SMALL CELL LUNG CANCER DETECTED BY POLYMERASE CHAIN REACTION SINGLE-STRAND CONFORMATION POLYMORPHISM ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    @@ Mutations of the p53 tumor suppressor gene are the most frequent genetic alterations detected in human lung cancer. To assess the pathogenic significance of p53 gene alterations in Chinese non-small cell lung cancer(NSCLC),74 paired samples of primary lung cancer and normal lung tissue far away from the cancer were analyzed for mutations of the p53 gene(exons 5-8) using exon-specific PCR, single-strand conformation polymorphism (PCR-SSCP). p53 mutations were observed in 55.4%(41/74) of the samples. No linkages were detected between the incidence of p53 mutations and histological type, lymph node metastasis,age or sex. Significant association between p53 mutations and degree of differentiation in adenocarcinomas, not in squamous cell carcinomas, was observed. The frequency of p53 mutations in smokers(65.3%) was higher than in nonsmokers(33.3%) and reached statistical significance.We also found p53 mutations in 6/7 samples which had tissue invasion and distant metastasis.These results suggest that smoking could be an important factor in lung carcinogenesis,p53 mutation is a worse prognosis indicator in adenocarcinomas and related to high aggressive behavior of human lung cancer.

  8. Expression of the class II tumor suppressor gene RIG1 is directly regulated by p53 tumor suppressor in cancer cell lines.

    Science.gov (United States)

    Hsu, Tzu-Hui; Chu, Chin-Chen; Jiang, Shun-Yuan; Hung, May-Whey; Ni, Wen-Chieh; Lin, Huai-En; Chang, Tsu-Chung

    2012-05-01

    Recent studies indicated that the RIG1 (RARRES3/TIG3) plays an important role in cell proliferation, differentiation, and apoptosis. However, the regulatory mechanism of RIG1 gene expression has not been clearly elucidated. In this study, we identified a functional p53 response element (p53RE) in the RIG1 gene promoter. Transfection studies revealed that the RIG1 promoter activity was greatly enhanced by wild type but not mutated p53 protein. Sequence specific mutation of the p53RE abolished p53-mediated transactivation. Specific binding of p53 protein to the rig-p53RE was demonstrated using electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) assay. Further studies confirmed that the expression of RIG1 mRNA and protein is enhanced through increased p53 protein in HepG2 or in H24-H1299 cells. In conclusion, our results indicated that RIG1 gene is a downstream target of p53 in cancer cell lines. PMID:22616991

  9. p53基因转移至移植心脏的安全性%Security for adenovirus-mediated p53 gene transfer to the donor heart

    Institute of Scientific and Technical Information of China (English)

    王丽平; 宋芳芳; 李祥禄; 刘越; 贾智博; 尹新华

    2011-01-01

    BACKGROUND: Wild-typep53 gene transfer to the donor heart can greatry inhibit graft co to nan/ artery intima hyperplasia andlumen narrowness.OBJECT P/E: To study the security of adenoviral-mediated wild-type p53 gene transfer to the donor heart after hearttransplantation.METHODS: Rat modee of heterotopic (abdomen) heart transplantation over e developed. Wetar rats served as donors and SOrats as recipients. After donor hearts were removed. 800 u Ladenoviral vector encoding the wild-type p53gene(Ajdp53group)adenoviral vector encoding the &-galactosidase gene (LacZ) (Ad-LacZ group) or saline (control group) were infused into thedonor heart respectively before transplantation. The donor heart was stored in the 4 ~C saline for 30 minutes before hearttransplantation. At5 days after operation. P53 protein expressions in coronary artery of donor hearts were tested by western blotanalyse. £123 days after transplantation, the serum specimen was collected for the biochemical indicators, and the major organsof the recipients were tested by the hetopathological analysis and the reverse transcription polymerase chain reaction of theadenoviral E1A sequences.RESULTS AND CONCLUSION: The expression of P53 protein was found in donor hearts inAd-p53 group at 5 days afteroperation, and no expression in Ad-LacZ group and control group. At28 days after operation, rat serum biochemistry values inthree groups was normal, the major organs of the recipients were not affected seriously, no virus spread to other organs in theexperimental protocol. The results confirmed that the ex vivo adenoviral-mediated gene transfer to the donor heart via thecoronary artery during the heart transplantation e safe.%背景:课题组前期实验表明野生型p53基因具有抑制移植心脏冠状动脉内膜增厚的作用.目的:研究腺病毒介导的野生型p53基因转移至移植心脏的安全性.方法:以Wistar大鼠为供体,SD大鼠为受体建立大鼠腹腔异位心脏移植模型,在取出

  10. The Impact of Adenosine Fast Induction of Myocardial Arrest during CABG on Myocardial Expression of Apoptosis-Regulating Genes Bax and Bcl-2

    Directory of Open Access Journals (Sweden)

    Ahmed Shalaby

    2009-01-01

    Full Text Available Background. We studied the effect of fast induction of cardiac arrest with denosine on myocardial bax and bcl-2 expression. Methods and Results. 40 elective CABG patients were allocated into two groups. The adenosine group (n=20 received 250 μg/kg adenosine into the aortic root followed by blood potassium cardioplegia. The control group received potassium cardioplegia in blood. Bcl-2 and bax were measured. Bax was reduced in the postoperative biopsies (1.38 versus 0.47, P=.002 in the control group. Bcl-2 showed a reducing tendency (0.14 versus 0.085, P=.07. After the adenosine treatment, the expression of both bax (0.52 versus 0.59, P=.4 and bcl-2 (0.104 versus 0.107, P=.4 remained unaltered after the operation. Conclusion. Open heart surgery is associated with rapid reduction in the expression of apoptosis regulating genes bax and bcl-2. Fast Adenosine induction abolished changes in their expression.

  11. Repression of p53-target gene Bbc3/PUMA by MYSM1 is essential for the survival of hematopoietic multipotent progenitors and contributes to stem cell maintenance.

    Science.gov (United States)

    Belle, J I; Petrov, J C; Langlais, D; Robert, F; Cencic, R; Shen, S; Pelletier, J; Gros, P; Nijnik, A

    2016-05-01

    p53 is a central mediator of cellular stress responses, and its precise regulation is essential for the normal progression of hematopoiesis. MYSM1 is an epigenetic regulator essential for the maintenance of hematopoietic stem cell (HSC) function, hematopoietic progenitor survival, and lymphocyte development. We recently demonstrated that all developmental and hematopoietic phenotypes of Mysm1 deficiency are p53-mediated and rescued in the Mysm1(-/-)p53(-/-) mouse model. However, the mechanisms triggering p53 activation in Mysm1(-/-) HSPCs, and the pathways downstream of p53 driving different aspects of the Mysm1(-/-) phenotype remain unknown. Here we show the transcriptional activation of p53 stress responses in Mysm1(-/-) HSPCs. Mechanistically, we find that the MYSM1 protein associates with p53 and colocalizes to promoters of classical p53-target genes Bbc3/PUMA (p53 upregulated modulator of apoptosis) and Cdkn1a/p21. Furthermore, it antagonizes their p53-driven expression by modulating local histone modifications (H3K27ac and H3K4me3) and p53 recruitment. Using double-knockout mouse models, we establish that PUMA, but not p21, is an important mediator of p53-driven Mysm1(-/-) hematopoietic dysfunction. Specifically, Mysm1(-/-)Puma(-/-) mice show full rescue of multipotent progenitor (MPP) viability, partial rescue of HSC quiescence and function, but persistent lymphopenia. Through transcriptome analysis of Mysm1(-/-)Puma(-/-) MPPs, we demonstrate strong upregulation of other p53-induced mediators of apoptosis and cell-cycle arrest. The full viability of Mysm1(-/-)Puma(-/-) MPPs, despite strong upregulation of many other pro-apoptotic mediators, establishes PUMA as the essential non-redundant effector of p53-induced MPP apoptosis. Furthermore, we identify potential mediators of p53-dependent but PUMA-independent Mysm1(-/-)hematopoietic deficiency phenotypes. Overall, our study provides novel insight into the cell-type-specific roles of p53 and its downstream

  12. 细胞凋亡相关基因Bcl-2及Bax在骨肉瘤中的表达与自下而上质量的关系%Expression of apoptosis related gene Bcl 2 and Bax in osteosarcoma and their relationship with the prognosis

    Institute of Scientific and Technical Information of China (English)

    黄鲁豫; 刘建; 王臻; 吕荣

    2002-01-01

    Objective Apoptosis related gene Bcl 2 and Bax in osteosarcoma patients with different clinical appearance were being studied to analyze the prognosis of the patients. Method The cases were divided into two different groups according to the results of the follow up.33 cases in high risk group and 18 cases in low risk group. Expression of Bcl 2 and Bax were immunohistochemically stained by ABC method. Result Positive expression rate of Bcl 2 was 61% in high risk group (20/23) and 33% in low risk group (1/8). Positive expression of Bax was 22% in high risk group (6/27) and 67% in low risk group(12/18).Conclusion Expression of Bcl 2 and Bax was related to the prognosis of osteosarcoma. Positively expressed Bcl 2 in osteosarcoma cells may indicate bad prognosis. If Bax is highly expressed in osteosarcoma cells, this may indicated a good prognosis.

  13. A Biomimic Reconstituted High-Density-Lipoprotein-Based Drug and p53 Gene Co-delivery System for Effective Antiangiogenesis Therapy of Bladder Cancer

    Science.gov (United States)

    Ouyang, Qiaohong; Duan, Zhongxiang; Jiao, Guangli; Lei, Jixiao

    2015-07-01

    A biomimic reconstituted high-density-lipoprotein-based drug and p53 gene co-delivery system (rHDL/CD-PEI/p53 complexes) was fabricated as a targeted co-delivery nanovector of drug and gene for potential bladder cancer therapy. Here, CD-PEI was utilized to effectively condense the p53 plasmid, to incorporate the plasmid into rHDL, and to act as an antitumor drug to suppress tumor angiogenesis. The rHDL/CD-PEI/p53 complexes exhibited desirable and homogenous particle size, neutral surface charge, and low cytotoxicity in vitro. The results of confocal laser scanning microscopy and flow cytometry confirmed that SR-BI-targeted function induced specific cytoplasmic delivery and high gene transfection efficiency in MBT-2 murine bladder cells. In addition, rHDL/CD-PEI/p53 complexes co-delivering CD and p53 gene achieved synergistic angiogenesis suppression by more effectively downregulating the expression of vascular endothelial growth factor (VEGF) messenger RNA (mRNA) and protein via different pathways in vitro. In vivo investigation on C3H/He mice bearing MBT-2 tumor xenografts revealed that rHDL/CD-PEI/p53 complexes possessed strong antitumor activity. These findings suggested that rHDL/CD-PEI/p53 complexes could be an ideal tumor-targeting system for simultaneous transfer of drug and gene, which might be a new promising strategy for effective bladder cancer therapy.

  14. Dietary selenomethionine increases exon-specific DNA methylation of the p53 gene in rat liver and colon mucosa.

    Science.gov (United States)

    Zeng, Huawei; Yan, Lin; Cheng, Wen-Hsing; Uthus, Eric O

    2011-08-01

    The regulation of site-specific DNA methylation of tumor suppressor genes has been considered as a leading mechanism by which certain nutrients exert their anticancer property. This study was to investigate whether selenium (Se) affects the methylation of globe genomic DNA and the exon-specific p53 gene. Three groups of rats (n = 6-7/group) were fed the AIN-93G basal diet supplemented with 0 [Se deficient (D)], 0.15 [Se adequate (A)], or 4 mg [Se supranutritional (S)] (Se as l-selenomethionine)/kg diet for 104 d, respectively. Rats fed the A or S diet had greater plasma and liver glutathione peroxidase activity, liver thioredoxin reductase activity, and plasma homocysteine concentration than those fed the D diet. However, compared with the A diet, rats fed the S diet did not further increase these Se-dependent enzyme activities or homocysteine concentration. In contrast, Se concentrations in kidney, liver, gastrocnemius muscle, and plasma were increased in a Se-dose-dependent manner. Interestingly, rats fed the S diet had significantly less global liver genomic DNA methylation than those fed the D diet. However, the S diet significantly increased the methylation of the p53 gene (exons 5-8) but not the β-actin gene (exons 2-3) DNA in liver and colon mucosa compared with those fed the D diet. Taken together, long-term Se consumption not only affects selenoprotein enzyme activities, homocysteine, tissue Se concentrations, and global genomic DNA methylation but also increases exon-specific DNA methylation of the p53 gene in a Se-dose-dependent manner in rat liver and colon mucosa.

  15. TATA-binding protein (TBP)-like protein is required for p53-dependent transcriptional activation of upstream promoter of p21Waf1/Cip1 gene.

    Science.gov (United States)

    Suzuki, Hidefumi; Ito, Ryo; Ikeda, Kaori; Tamura, Taka-Aki

    2012-06-01

    TATA-binding protein-like protein (TLP) is involved in development, checkpoint, and apoptosis through potentiation of gene expression. TLP-overexpressing human cells, especially p53-containing cells, exhibited a decreased growth rate and increased proportion of G(1) phase cells. TLP stimulated expression of several growth-related genes including p21 (p21(Waf1/Cip1)). TLP-mediated activation of the p21 upstream promoter in cells was shown by a promoter-luciferase reporter assay. The p53-binding sequence located in the p21 upstream promoter and p53 itself are required for TLP-mediated transcriptional activation. TLP and p53 bound to each other and synergistically enhanced activity of the upstream promoter. TLP specifically activated transcription from the endogenous upstream promoter, and p53 was required for this activation. Etoposide treatment also resulted in activation of the upstream promoter as well as nuclear accumulation of TLP and p53. Moreover, the upstream promoter was associated with endogenous p53 and TLP, and the p53 recruitment was enhanced by TLP. The results of the present study suggest that TLP mediates p53-governed transcriptional activation of the p21 upstream promoter.

  16. Research Advance of P53 Gene in Mantle Cell Lymphoma——Review%套细胞淋巴瘤中P53基因的研究进展

    Institute of Scientific and Technical Information of China (English)

    周立涛; 朱家斌

    2011-01-01

    Mantle cell lymphoma (MCL) is an independent uncommon subtype of B-cell non-Hodgkin's lymphoma (NHL) according to World Health Organization classification of hematopoietic and lymphoid tissue tumors. The genetic hallmark of MCL is the chromosomal translocation t (11;14) (q13;q32) that leads to upregulation of cyclin D1, an important regulator of the G1 phase in the cell cycle. This genetic aberration is virtually present in all cases of MCL. It is characterized by distinct clinical features and outcome which is affected by a series of additional genetic aberration including the genomic guardian-P53 gene. This article reviews the effects of P53 gene aberrations including P53 deletion, mutation and their mutual relationship in MCL, and novel therapeutic regimens for MCL patients with P53 aberrations.%套细胞淋巴瘤(mantle cell lymphoma,MCL)是2001年WHO淋巴造血组织肿瘤新分类中的一种独立的B细胞非霍奇金淋巴瘤,几乎所有的MCL都有t(11;14)(q13;q32)易位,此易位使11q13上的BCL-1癌基因(cyclin D1)与14q32上的IgH基因重排,导致cyclin D1过度表达,促进细胞由G1期进入S期而使G1期缩短.MCL临床病程和转归呈异质性,许多临床和实验室特征可影响其预后,其中P53基因的异常与MCL的病程及转归密切相关.本文就P53基因的缺失、突变与MCL的关系,P53异常患者的治疗作一综述.

  17. Forkhead transcription factor FOXF1 is a novel target gene of the p53 family and regulates cancer cell migration and invasiveness.

    Science.gov (United States)

    Tamura, M; Sasaki, Y; Koyama, R; Takeda, K; Idogawa, M; Tokino, T

    2014-10-01

    p53 is an established tumor suppressor that can activate the transcription of multiple target genes. Recent evidence suggests that p53 may contribute to the regulation of cell invasion and migration. In this study, we show that the forkhead box transcription factor FOXF1 is a novel target of the p53 family because FOXF1 is upregulated by p53, TAp73 and TAp63. We show that FOXF1 is induced upon DNA damage in a p53-dependent manner. Furthermore, we identified a response element located within the FOXF1 gene that is responsive to wild-type p53, TAp73β and TAp63γ. The ectopic expression of FOXF1 inhibited cancer cell invasion and migration, whereas the inactivation of FOXF1 stimulated cell invasion and migration. We also show that FOXF1 regulates the transcriptional activity of E-cadherin (CDH1) by acting on its FOXF1 consensus binding site located upstream of the E-cadherin gene. Collectively, our results show that FOXF1 is a p53 family target gene, and our data suggest that FOXF1 and p53 form a portion of a regulatory transcriptional network that appears to have an important role in cancer cell invasion and migration.

  18. The Expression of Apoptosis-Related Genes Bcl-2 and Bax Protein and Apoptosis Positivity in Cervical Carcinoma during Irradiation

    Institute of Scientific and Technical Information of China (English)

    ZHAODongli; SHIJingsen; LIMingzhong; SONGLiping; WANGShuwen

    2005-01-01

    Objective: To evaluate the apoptosis positivity, the expression of Bcl-2. bax proteins in 30 patients with squamous cell cervix carcinoma before and after radiotherapy. Methods: By using immunohistochemical and TDT-dUTP nick end labelling techniques. 30 cases of squamous cell cervical carcinoma were analyzed. Results: The apoptosis positivity before and after irradiation was 76.7%, and 100% respectively, with the difference being significant (P<0.05); The positive rates of Bcl-2 protein before and after irradiation were 73.3% and 46.7% respectively, with the difference being significant (P<0.05): The positive rates of bax protein before and after irradiation were 86% and 100 respectively, with the difference being significant (P<0.05). Conclusion: bax and Bcl-2 protein play an important role in apoptosis induced by fractionated radiation therapy. Apoptosis induced by irradiation is contributed to upregulation of bax protein or downregulation of Bcl-2 protein.

  19. Differential effects of two pro-apoptotic members of the Bcl-2 gene family on murine bone quality

    Science.gov (United States)

    Wise, Lisa Marie

    Bax and Hrk are pro-apoptotic members of the Bcl-2 gene family. Both Bax and Hrk have been previously implicated in ovarian cell survival. Effects on bone cells have also been studied in several members of the Bcl-2 gene family; thus, the focus of this work was to characterize the bone quality of mice deficient in Bax or Hrk. Bone quality of various age groups (3, 6, 12, 6 and 22 months) of Bax-knockout (KO) and Hrk-KO female mice were compared to age-matched control female mice. Additional groups of 6-month mice were ovariectomized (OVX) to determine whether effects are dependent on ovarian function. Dual energy x-ray absorptiometry was performed on all mice to determine bone mineral density (BMD). To evaluate bone mechanical properties, 3-point bending, torsion testing and femoral neck fracture were performed on femora, while compression was performed on individual vertebrae. Mechanical properties were rationalized through evaluation of structural (strut analysis, micro computed tomography), remodeling (histomorphometry, osteoclast staining) and material (back-scattered electron imaging, x-ray diffraction) properties. Aged Bax-KO mice do not experience the loss in BMD, bone mechanics and trabecular bone structural properties typically observed with age. Enhanced ovarian cell numbers in Bax-KO mice likely indirectly leads to this enhanced bone phenotype. Ovariectomy results in the loss of the enhanced trabecular bone phenotype, but does not affect the cortical bone phenotype. As such, cortical bone may be protected from typical OVX effects due to sustained osteoblast function in Bax-KO mice. By contrast, young Hrk-KO mice exhibit higher BMD and trabecular bone structural properties compared to control mice, coupled with a compromised mechanical integrity. This subtle transient osteopetrotic-like phenotype is likely influenced by a potentially augmented osteoblast survival, albeit with a compromised activity. This osteopetrotic-like phenotype, and the effect of Hrk

  20. 人乳腺癌组织中p53基因单核苷酸多态性位点变异的研究%p53 gene mutation in human breast cancer tissues

    Institute of Scientific and Technical Information of China (English)

    王平; 任玮; 张玉和; 赵亮; 张玉宝

    2010-01-01

    目的 观察乳腺癌患者p53基因的单核苷酸多态性位点(SNPs)变异,探讨p53基因在乳腺癌癌基因学中的意义.方法 选取p53基因位于外显子及内含子的共3对引物,利用SSCP(单链多肽构象)分析方法对30例乳腺癌样品进行分析及DNA测序.结果 在检测的30例乳腺癌组织样品中,p53基因在第一内含子和第七内含子中共有4个碱基替换被检测出,其中3个为Hapmap(Hapolotype Map Project,国际单倍型图谱计划)中已公布的SNP位点,另外1个从未被确认.在p53第7内含子位置处发现一高突变率(20%)的G→A(rs12947788)类型基因替换,在其上游20个碱基位置处存在另一已知高突变率的SNP位点A→C(rs12951053),此两者联合出现,在所检测的30例乳腺癌组织样本中共发现6例,占所检测标本的20%.结论 p53基因的SNPs分析对乳腺癌的早期发现、治疗和预后有一定意义.%Objective To investigate the possible implication of the substitution at single Nucleotide Polymorphisms (SNPs) sites in p53 genes in the carcinogenesis of breast cancer. Methods The SNPs in p53 gene regions from 30 patients with breast cancer were analyzed by polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) and subsequent DNA sequencing. Results The totally 4 nucleotide substittution sites at the regions of intron 1 and intron 7 of p53 detected were found in 30 cases of breat cancer, which involved 3 published SNPs sites and 1 uncharacterized site. Among these substitutions, a G →A (rs12947788) mutation which occurred at the intron 7 was coupled with the cystidine nucleotide at a SNPs site A→C (rs12951053) of 20th nucleotide at its upstream, which occupied 20% of the breast cancer patients, implicaing the significance of the coupling of these two sites in the carcinogenesis of the breast cancer. Conclusion The DNA substitution analysis at the SNPs sites of p53 may serve as a helpful tool for the early diagnosis of breast

  1. P53 GENE MUTATIONS IN NON-SMALL CELL LUNG CANCER DETECTED BY POLYMERASE CHAIN REACTION SINGLE-STRAND CONFORMATION POLYMORPHISM ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    赵永良; 吴德昌; 项晓琼; 张宝仁; 周乃康; 胡迎春

    1999-01-01

    Mutations of the p53 tumor suppressor gone are the most frequent genetic akerations detected in human lung cancer. To assess the pathogenic significance of p53 gone alterations in Chlnege non-small cell lung cancer (NSCLC), 74 paired samples of primary lung cancer and normal lung tissue far away from the cancer were analyzed for mutations of the p53 gene(exons 5-8) using exon-specific PCR, single-gtrand conformation polymorphimax (PCR-SSCP). p53 mutations were observed in 55.4% (41/74) of the samples.No linkaiges were detected between the incidence of p53 mutations and histological type, lymph node metastasis, age or sex. Significant association between p53 mutations and degree of differentiation in edenotmremmnas, not in squamous cell carcinomas, was observed, The frequency of p53 mutations in(65. 3%) was higher than in nonsmokers (33. 3%) and reached stafisrical significance. We also found p53 mutations in 6/7 samples which had tissue invasion and distant metastasis. These results suggest that smcking could be an important factor in lung carcinogenesis, p53 mutation is a worse prognosis indicator in ade and nocarcinomas and related to high aggressive behavior of human lung cancer.

  2. Evaluation of Bcl-2 Family Gene Expression in Hippocampus of 3, 4-methylenedioxymethamphetamine Treated Rats

    OpenAIRE

    Hamed Hashemi-Nasl; Mohammad Taghi Joghataei; Alireza Samzadeh-Kermani; Seyed Behnamedin Jameie; Mansoure Soleimani; Ali Samadikuchaksaraei; Mohammad Hassan Farhadi; Kazem Mousavizadeh; Sara Soleimani Asl; Mehdi Mehdizadeh

    2012-01-01

    Objective: 3,4-methylenedioxymethamphetamine (MDMA) is an illicit, recreational drug that causes cellular death and neurotoxicity. This study evaluates the effects of different doses of MDMA on the expression of apoptosis–related proteins and genes in the hippocampus of adult rats. Materials and Methods: In this expremental study,a total of 20 male Sprague Dawley rats (200-250 g ) were treated with MDMA (0, 5, 10, 20 mg/kg i.p. twice daily) for 7 days. Seven days after the last administration...

  3. The absence of Ser389 phosphorylation in p53 affects the basal gene expression level of many p53-dependent genes and alters the biphasic response to UV exposure in mouse embryonic fibroblasts

    NARCIS (Netherlands)

    O. Bruning; W. Bruins; M.J. Jonker; E. Zwart; T.V. van der Hoeven; J.L.A. Pennings; H. Rauwerda; A. de Vries; T.M. Breit

    2008-01-01

    Phosphorylation is important in p53-mediated DNA damage responses. After UV irradiation, p53 is phosphorylated specifically at murine residue Ser389. Phosphorylation mutant p53.S389A cells and mice show reduced apoptosis and compromised tumor suppression after UV irradiation. We investigated the und

  4. p53 Promoter-based Reporter Gene in vitro Assays for Quick Assessment of Agents with Genotoxic Potential

    Institute of Scientific and Technical Information of China (English)

    Huaixing LI; Ke SHI; Ruiwen CHEN; Yan HE; Dan WU; Shuhan SUN

    2007-01-01

    The p53 promoter-based green fluorescent protein (GFP) and luciferase reporter gene assays have been established for detecting DNA damage induced by genotoxic agents.To evaluate the system,NIH3T3 cells transfected with either pHP53-GFP or pMP53-GFP construct were treated with mitomycin or 5-fluorouracil.Expression of the GFP reporter gene was significantly and specifically induced in the cells exposed to mitomycin or 5-fluorouracil.Then we treated NIH3T3 cells harboring pHP53-Luc or pMP53-Luc vector with mitomycin,5-fluorouracil or cisplatin at various concentrations.Similarly,exposure of the cells to these agents with genotoxic potentials resulted in a dose-dependent induction in luciferase reporter gene expression.Thus,these in vitro reporter gene assays could provide an ideal system for quick assessment or screening of agents with genotoxic potential.

  5. Production of p53 gene knockout rats by homologous recombination in embryonic stem cells

    OpenAIRE

    Tong, Chang; Li, Ping; Wu, Nancy L; Yan, Youzhen; Ying, Qi-Long

    2010-01-01

    The use of homologous recombination to modify genes in embryonic stem (ES) cells provides a powerful means to elucidate gene function and create disease models1. Application of this technology to engineer genes in rats has previously been impossible in the absence of germline competent ES cells in this species. We have recently established authentic rat ES cells2, 3. Here we report the generation of the first gene knockout rats using the ES cell-based gene targeting technology. We designed a ...

  6. Isolation and identification of proteins binding to the major breakpoint region(mbr) of bcl2 gene

    Institute of Scientific and Technical Information of China (English)

    Nan Yang; Yujie Sun; Changyan Ma

    2009-01-01

    Objective: We have previously found that mbr is a regulatory element of the bcl2 gene. The objective of this study is to isolate and identify the proteins binding to the 37 mbr in the 3 '-end of the mbr. Methods: Streptavidin magnetic particles were ligated to concatameric oligonucleofides of 37 mbr and incubated with the nuclear extracts of Jurkat cells. The DNA-binding proteins were eluted and then resolved by SDS-PAGE. After silver staining, the protein bands were excised and subjected to MALDI-TOF MS. Results: Several protein bands were detected after the isolation with magnetic particles, and Splicing factor, proline-and glutamine-rich(SFPQ), Poly(ADP-ribose)polymerase I(PARP), and promyelocytic leukemia protein(PML) were identified by MALDI-TOF MS. Conclusion: Several proteins were isolated and identified from the 37 mbr-protein complex. Results of this study establish a foundation for further study of the mechanisms by which mbr executes its regulatory function.

  7. The bcl-2, bax gene expression and apoptosis of continuous low-dose-rate irradiation on PC-3 transplanting tumor

    International Nuclear Information System (INIS)

    Objective: The aim of this study was to investigate bcl-2, bax expression and apoptosis of continuous low-dose-rate irradiation on prostate cancer (PC)-3 transplanting tumor. Methods: The expression of bcl-2 and bax associated with apoptosis between experiment and control groups were analyzed using immunohistochemistry at 48, 96 and 192 h after two 125I seed sources implanting model. The correlation between apoptosis and the ratio of bax/bcl-2 was analyzed using Bi-variable linear correlation. SPSS 11.0 was used to analyse the data. Results: The bcl-2 expression in experiment group began to down-regulated significantly after 125I seed irradiation for 48 h as compared with control(t=2.500, P=0.067), though it was not reached to statistical significance. At 96 and 192 h after irradiation, significantly low expression of bcl- 2 were noted (t=4.950, 3.464; P=0.008 and 0.026). In contrast, significantly over expression of bax was noted at 48, 96 and 192 h after 12si irradiation (t=3.334,4.025,5.292;P=0.029, 0.016 and 0.006). The apoptotic index (AI) for PC-3 at 48, 96 and 192 h after 125I irradiation were 22.3%, 21.7% and 30.7%, which was significantly higher than controls when at 96 and 192 h after 125I irradiation (P= 0.016 and 0.036). Moreover, positive correlation was noted between AI and bax/bcl-2 ratio (r=0.784, P= 0.012). Conclusion: Low-dose-rate irradiation could down-regulate the expression of bcl-2, up-regulate the expression of bax and induced PC-3 cells apoptosis. (authors)

  8. Global genomic profiling reveals an extensive p53-regulated autophagy program contributing to key p53 responses

    OpenAIRE

    Kenzelmann Broz, Daniela; Spano Mello, Stephano; Bieging, Kathryn T.; Jiang, Dadi; Rachel L Dusek; Brady, Colleen A.; Sidow, Arend; Attardi, Laura D.

    2013-01-01

    To gain new insights into p53 biology, Kenzelmann Broz et al. used high-throughput sequencing to analyze global p53 transcriptional networks in primary mouse embryo fibroblasts in response to DNA damage. This approach identified autophagy genes as direct p53 target genes. p53-induced autophagy was important for both p53-dependent apoptosis and transformation suppression by p53. These data highlight an intimate connection between p53 and autophagy and suggest that autophagy contributes to p53-...

  9. Detection of mutations within exons 4 to 8 of the p53 tumor suppressor gene in canine mammary glands

    Directory of Open Access Journals (Sweden)

    D.M.B. Souza

    2012-04-01

    Full Text Available Fifteen female canines with mammary tumors and 6 normal females were used to study mutations in exons 4 to 8 of the p53 gene. DNA samples from the tumors, respective adjacent normal mammary tissue and mammary glands from healthy animals were sequenced and analyzed for the presence of mutations. Mutations were found in 71.8% of the samples and the most frequent were missense mutations. The most attacked exons in the mammary tumor were 5, 7 and 8, with 23.4, 31.6 and 23.4% mutations, respectively. Canine mammary tumors are related to mutations in gene p53 and mutations mostly occur in the region of the protein that is linked to the DNA in the cell nucleus, which can change the functionality of the cell and propitiate tumor growth. Despite being macroscopically normal, the mammary tissue adjacent to the tumors has mutations that can lead to recurrence if not removed together with the tumor.

  10. 应用bcl-2基因及GDNF治疗大鼠脑缺血的研究%The Effect of bcl-2 Gene and GDNF of Rats after Focal Cerebral Ischemia Reperfusion Injury

    Institute of Scientific and Technical Information of China (English)

    ZHOU Tie-zhu; FU Xia

    2009-01-01

    目的 观察胶质细胞源性神经营养因子(GDNF)与bcl-2基因对大鼠局灶性脑缺血再灌注损伤(CIRI)的影响.方法 取健康Wistar大鼠40只,采用Longa改良栓线法制成大脑中动脉闭塞(MCAO)模型,缺血2 h后再灌注,随机分4组:对照组、bcl-2组、GDNF组、bcl-2+GDNF组,于再灌注3 h后经侧脑室注射GDNF 10μl、经颈动脉注射pLXSN-bcl-2质粒10μg,MCAO后3d(n=5),14 d(n=5),通过免疫组化染色检测bcl-2蛋白和GDNF的表达情况,TUNEL法检测细胞凋亡情况.结果 bcl-2+GDNF组bcl-2蛋白表达与GDNF表达水平均较其他组表达明显增加(P<0.05),bcl-2组、GDNF组较对照组明显增加(P<0.05);脑内细胞凋亡GDNF+bcl-2组较其他组明显减少(P<0.05),bcl-2组、GDNF组较对照组明显减少(P<0.05).结论 bcl-2基因和GDNF可能通过减少神经细胞凋亡,促进bcl-2与GDNF蛋白表达,增强对局灶性缺血脑组织的保护能力,加速中枢神经损伤的修复;bcl-2基因与GDNF协同作用,促使神经细胞在脑内的凋亡进一步减少,从而避免脑缺血再灌注后脑细胞进一步损伤.

  11. Deficiency in p53 is required for doxorubicin induced transcriptional activation of NF-κB target genes in human breast cancer

    Science.gov (United States)

    Dalmases, Alba; González, Irene; Menendez, Silvia; Arpí, Oriol; Corominas, Josep Maria; Servitja, Sonia; Tusquets, Ignasi; Chamizo, Cristina; Rincón, Raúl; Espinosa, Lluis; Bigas, Anna; Eroles, Pilar; Furriol, Jessica; Lluch, Anna; Rovira, Ana; Albanell, Joan; Rojo, Federico

    2014-01-01

    NF-κB has been linked to doxorubicin resistance in breast cancer patients. NF-κB nuclear translocation and DNA binding in doxorubicin treated-breast cancer cells have been extensively examined; however its functional relevance at transcriptional level on NF-κB -dependent genes and the biological consequences are unclear. We studied NF-κB -dependent gene expression induced by doxorubicin in breast cancer cells and fresh human cancer specimens with different genetic backgrounds focusing on their p53 status. NF-κB -dependent signature of doxorubicin was identified by gene expression microarrays in breast cancer cells treated with doxorubicin and the IKKβ-inhibitor MLN120B, and confirmed ex vivo in human cancer samples. The association with p53 was functionally validated. Finally, NF-κB activation and p53 status was determined in a cohort of breast cancer patients treated with adjuvant doxorubicin-based chemotherapy. Doxorubicin treatment in the p53-mutated MDA-MB-231 cells resulted in NF NF-κB driven-gene transcription signature. Modulation of genes related with invasion, metastasis and chemoresistance (ICAM-1, CXCL1, TNFAIP3, IL8) were confirmed in additional doxorubicin-treated cell lines and fresh primary human breast tumors. In both systems, p53-defcient background correlated with the activation of the NF-κB -dependent signature. Furthermore, restoration of p53WT in the mutant p53 MDA-MB-231 cells impaired NF-κB driven transcription induced by doxorubicin. Moreover, a p53 deficient background and nuclear NF-κB /p65 in breast cancer patients correlated with reduced disease free-survival. This study supports that p53 deficiency is necessary for a doxorubicin driven NF-κB -response that limits doxorubicin cytotoxicity in breast cancer and is linked to an aggressive clinical behavior. PMID:24344116

  12. 视网膜母细胞瘤Bcl-2和Bax基因蛋白质表达%Expression of Bcl-2 and Bax gene protein in retinoblastoma

    Institute of Scientific and Technical Information of China (English)

    张小猛; 庞利民; 张晓光

    2000-01-01

    目的:研究凋亡及凋亡调控基因Bcl-2/Bax和视网膜母细胞瘤(Retinoblastoma,RB)的发生、发展及退化的关系.方法:收集36例RB标本,对其分别进行Bcl-2和Bax基因的蛋白质免疫组织化学染色.对其表达情况和染色强度进行观察.结果:①Bcl-2在分化型RB中表达比较好;②Bax在未分化型和分化型中表达都比较好.结论:①分化型和未分化型RB中都有Bcl-2/Bax基因蛋白表达;②随RB恶性度的增加,Bcl-2的表达逐渐减弱;Bax的表达无明显改变.③分化型RB受Bcl-2和Bax基因共同控制;未分化型RB受Bax基因调控,Bcl-2基因发挥很少的作用.

  13. Effect of the p53 gene status on the sensitivity of oral squamous cell carcinoma cells to boron neutron capture therapy

    International Nuclear Information System (INIS)

    The role of the p53 gene in the sensitivity of oral squamous cell carcinoma (SCC) to boron neutron capture therapy (BNCT) had not been studied. We examined the effect of boronophenylalanine (BPA)-mediated BNCT on oral SCC cells showing either wild-type p53 (SAS/neo) or mutated-type p53 (SAS/mp53). Survival ratio of cells was determined by colony formation. Cell viability was measured by MTT assay. Apoptotic cells were evaluated by flow cytometric analysis and nuclear DNA staining. When SAS/neo and SAS/mp53 cells were subjected to BNCT, more suppressive effects on colony formation and cell viability were observed in SAS/neo cells as compared with SAS/mp53. The proportion of apoptotic cells with DNA fragmentation was also increased in the cells with functional p53. These results suggest that oral SCC cells with mutated p53 cells are more resistant to BNCT than those with wild-type p53. BNCT must inhibit oral SCC cells in p53-dependent and p53-independent mechanisms. (author)

  14. Expression of Bcl-2 in cells with different telomerase activities

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Both telomerase and Bcl-2 are important genes in controlling apoptosis. The activation of telomerase and the abnormal regulation of Bcl-2 are also closely related to carcinogenesis. However, little is known about the linkage between telomerase and Bcl-2. The effect of activated telomerase on the expression of Bcl-2 has been investigated. It is demonstrated that in tumor and transformed cells with higher telomerase activity, Bcl-2 expression is significantly lower than that in telomerase negative or less telomerose activity cells. Further study showed that in the telomerase gene-transformed 2BS-fibroblasts, Bcl-2 expression is inhibited significantly while the exogenous telomerase catalytic subunit gene is re-expressed in fibroblasts. Results indicated that there might be a certain linkage between the expression of telomerase and Bcl-2, and overexpression of exogenous telomerase gene might down regulate the expression of Bcl-2.

  15. Effect of P53 binding site on regulation of human NOD8 gene%P53结合位点对人NOD8基因的调控

    Institute of Scientific and Technical Information of China (English)

    曾琪; 张芸; 田莉; 唐清亮; 胡巢凤; 柏志全

    2011-01-01

    目的:探讨P53结合位点在NOD8基因调控中的作用.方法:利用生物信息学方法,我们发现人与黑猩猩的NOD8基因核心启动子区域相似位置含有P53结合位点;以人基因组DNA为模板,PCR扩增含有人NOD8基因序列,构建含有/缺失人P53结合位点的NOD8基因启动子驱动的、表达绿色荧光蛋白-NOD8融合蛋白的质粒pNOD8(760 bp)-EGFP-NOD8和mpNOD8(750 bp)-EGFP-NOD8;将构建的重组质粒经阳离子聚合物JetPeiTM介导瞬时转染HEK293细胞中,并加入不同浓度的P53抑制剂pifithrin alpha(PFT-α)处理HEK293细胞,用RT-PCR和Westren blotting 方法检测NOD8 mRNA和蛋白的表达;此外,用pNOD8(760 bp)-EGFP质粒转染HEK293细胞,利用染色质免疫共沉淀法(ChIP)观察P53是否与NOD8启动子结合.结果:经酶切鉴定和序列测定证实重组质粒构建成功.ChIP实验证实P53能与NOD8启动子结合.pNOD8 (760 bp)-EGFP-NOD8 转染组中NOD8 mRNA的表达显著高于pEGFP-C2转染组(P<0.05),并且NOD8 mRNA 在缺失人P53结合位点的mpNOD8 (750 bp)-EGFP-NOD8转染组中的表达明显降低(P<0.01);同时发现加入 PFT-α的pNOD8(760 bp)-EGFP-NOD8 转染组NOD8 mRNA的表达显著下降,并呈剂量依赖关系,其中90 μmol/L PFT-α对NOD8 mRNA表达的抑制作用最为显著(P<0.01).与mRNA检测结果一致的是pNOD8(760 bp)-EGFP-NOD8 转染组NOD8蛋白的表达量显著高于对照组pEGFP-C2;而mpNOD8(750 bp)-EGFP-NOD8转染组NOD8蛋白的表达量明显低于pNOD8(760 bp)-EGFP-NOD8转染组和加入 PFT-α的pNOD8(760 bp)-EGFP-NOD8 转染组(P<0.01).结论:P53结合位点在NOD8基因调控中起着重要的作用,并且P53结合位点与NOD8基因之间可能存在正反馈调节.%AIM: To investigated the characterization and biological function of P53 binding element in the regulation of N0D8 gene. METHODS: Using the method of bioinformatics, we found a completely preserved P53 binding site in N0D8 core promoter both in humans and chimpanzees. N0D8

  16. p53 inhibits the expression of p125 and the methylation of POLD1 gene promoter by downregulating the Sp1-induced DNMT1 activities in breast cancer

    Directory of Open Access Journals (Sweden)

    Zhang L

    2016-03-01

    Full Text Available Liang Zhang,1 Weiping Yang,2 Xiao Zhu,1 Changyuan Wei1 1Department of Breast Surgery, 2Department of Ultrasound, Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi, People’s Republic of China Abstract: p125 is one of four subunits of human DNA polymerases – DNA Pol δ as well as one of p53 target protein encoded by POLD1. However, the function and significance of p125 and the role that p53 plays in regulating p125 expression are not fully understood in breast cancer. Tissue sections of human breast cancer obtained from 70 patients whose median age was 47.6 years (range: 38–69 years with stage II–III breast cancer were studied with normal breast tissue from the same patients and two human breast cell lines (MCF-7 and MCF-10A. p53 expression levels were reduced, while p125 protein expression was increased in human breast cancer tissues and cell line detected by Western blot and quantitative reverse transcriptase-polymerase chain reaction. The methylation level of the POLD1 gene promoter was greater in breast cancer tissues and cells when compared with normal tissues and cells. In MCF-7 cell model, p53 overexpression caused a decrease in the level of p125 protein, while the methylation level of the p125 gene promoter was also inhibited by p53 overexpression. To further investigate the regulating mechanism of p53 on p125 expression, our study focused on DNA methyltransferase 1 (DNMT1 and transcription factor Sp1. Both DNMT1 and Sp1 protein expression were reduced when p53 was overexpressed in MCF-7 cells. The Sp1 binding site appears to be important for DNMT1 gene transcription; Sp1 and p53 can bind together, which means that DNMT1 gene expression may be downregulated by p53 through binding to Sp1. Because DNMT1 methylation level of the p125 gene promoter can affect p125 gene transcription, we propose that p53 may indirectly regulate p125 gene promoter expression through the control of DNMT1 gene transcription. In

  17. Estudo do polimorfismo genético no gene p53 (códon 72 em câncer colorretal Role of the genetic polymorphism of p53 (codon 72 gene in colorectal cancer

    Directory of Open Access Journals (Sweden)

    Jacqueline Miranda de Lima

    2006-03-01

    Full Text Available RACIONAL: Polimorfismos genéticos são variações genéticas que podem ocorrer em seqüências codificadoras e não-codificadoras, levando a alterações qualitativas e/ou quantitativas das proteínas em questão. O p53 é o gene mais comumente alterado no câncer humano. O polimorfismo desse gene no códon 72 ocorre por substituição de uma base e tem sido associado a maior risco de câncer. OBJETIVO: Determinar a possível associação entre o polimorfismo no códon 72 (72 arginina/prolina do gene p53 e câncer colorretal. CASUÍSTICA E MÉTODOS: Foram avaliados em 100 pacientes com câncer colorretal e em 100 indivíduos sem câncer, pareados quanto ao sexo idade, o hábito de fumar, o etilismo e no grupo caso o estádio, o grau de diferenciação e a evolução da doença. O genótipo (72 arginina/prolina foi determinado por PCR, utilizando-se primers (seqüências de nucleotídeos específicos. RESULTADOS: O genótipo homozigoto arginina/arginina foi prevalente em 56% no grupo controle e em 58% no grupo caso. Não se observou diferença entre os dois grupos. No estádio IV este genótipo foi mais freqüente quando comparado ao estádio I (80% versus 14%. Não se observou diferença entre as variações do genótipo e fumo, álcool, evolução clínica ou grau de diferenciação. CONCLUSÃO: A prevalência do genótipo arginina/arginina foi a mais freqüente nos dois grupos. Não foi encontrada correlação entre maior risco de câncer e o polimorfismo no códon 72 prolina/arginina do gene p53. Apesar do pequeno número de doentes com câncer em estádio avançado (IV, estes tiveram maior prevalência do genótipo arginina/arginina.BACKGROUND: Polymorphisms are genetic variations that can occur in sequences of codons, leading to defective proteins. p53 is the most commonly gene affected in human cancer. The polymorphism of this gene occurs by a substitution of a base in codon 72 and may increase the risk of cancer. AIM: To investigate the

  18. Polymorphism of p53 gene in induced sputum cells among coke oven workers%焦炉工人痰细胞p53基因外显子突变检测

    Institute of Scientific and Technical Information of China (English)

    张萍; 郑金平; 孙建娅

    2011-01-01

    目的 探讨焦炉工人痰细胞p53基因突变与焦炉暴露关系.方法 选取某焦化厂125名焦炉作业工人(炉底38人,炉侧45人,炉顶42人)作为暴露组,同时选取同厂37名材料管理工人作为对照组;个体采样法对作业环境进行监测;高渗盐水超声雾化法诱导取痰,分离痰细胞;高效液相色谱法检测环境空气样本B[a]P和尿中1-羟基芘的水平;聚合酶链式反应-单链构象多态性方法(PCR-SSCP)检测痰细胞p53基因突变的情况.结果 暴露组中炉顶工人组痰细胞p53基因6、7外显子和p53基因5、6、7外显子总突变率分别为14.3%,21.4%,33.3%,明显高于对照组(0%,5.4%,5.4%),差异有统计学意义(P<0.05),且总突变率有随外暴露水平升高而升高的趋势(x2=7.457,P<0.01);经多元Logistic回归分析,焦炉暴露、炉顶暴露、炉底暴露和年龄的调整OR值(95% CI)分别为25.278(3.461~184.625)、7.359(1.017 ~53.267)、22.228(3.146 ~ 157.082)、1.106(1.011 ~1.211),是焦炉工人痰细胞p53基因突变率升高的主要危险因素.结论 焦炉逸散物可诱发焦炉工人的痰细胞p53基因突变率升高,且与暴露水平有关.%Objective To explore the relationship between the mutation of p53 gene in induced sputum cells and the exposure to PAHs among coke oven workers. Methods Totally 125 coke oven workers in a steel factory were selected as exposed group and 37 workers from the warehouse of the same factory without occupational carcinogen exposure were selected as control group. The working environment was monitored with individual sampling method. Sputum was induced and collected with ultrasonic nebulization of hypertonic saline and the sputum cells were separated. Uurine samples were collected from the workers after the night shift. The concentrations of urinary l-hydroxypyrene( HpU) and benzo( a) pyrene in the air were measured using high performance liquid chromatography( HPLC) and the p53 gene mutation in

  19. p53-dependent gene profiling for reactive oxygen species after benzene inhalation: special reference to genes associated with cell cycle regulation.

    Science.gov (United States)

    Hirabayashi, Yoko

    2005-05-30

    Benzene toxicity has long been thought to be due to its metabolites including reactive oxygen species (ROS). However, the major toxicological effect of benzene in wild-type mice carrying normal alleles of the p53 gene appears to be the significant perturbation of cell cycle regulation, possibly via an indirect signaling pathway. Other prominent genotoxic cellular damage can occur in the absence of cell cycle arrest in p53 gene deficiency. The suppression of cell cycle is clearly detected using a tool for stem-cell-specific cell cycle observation by the BU-UV method. Cells (including hemopoietic progenitor cells) in S-phase are labeled in vivo with bromodeoxyuridine (BrdU) and then exposed to near-ultraviolet (UV) light to kill cells that incorporated BrdU. The target fraction, the S-phase, is then evaluated on the basis of decreased numbers of hemopoietic colonies formed in assays such as for granulomacrophage colony-forming units (CFU-GM). Benzene toxicity was found to be more prominent in the primitive stem-cell compartment, as first suggested more than 20 years ago. Interestingly, when one examines the stem-cell-specific steady-state gene expression profiling, several key genes associated with benzene exposure are specifically identified, including CYP2E1. Benzene toxicity was found to be mediated by aryl hydrocarbon receptor (AhR) at an expression level; thus, the effect of benzene can be detected in nature at lower levels in the stem-cell compartment than expected. Alterations in gene expression profiles compared with those in steady-state gene expression profiles in the stem-cell compartment may elucidate the mechanism underlying benzene toxicity. Functional gene expressions after benzene exposure are not always detected, because their phenotypic expressions are often masked by the balance of expression of genes participating in various pathways of homeostasis, for example, p53. Thus, the actual expressions of the above-mentioned cell cycle-related genes may

  20. Increased ratio of anti-apoptotic to pro-apoptotic Bcl2 gene-family members in lithium-responders one month after treatment initiation

    Directory of Open Access Journals (Sweden)

    Lowthert Lori

    2012-09-01

    Full Text Available Abstract Background Lithium is considered by many as the gold standard medication in the management of bipolar disorder (BD. However, the clinical response to lithium is heterogeneous, and the molecular basis for this difference in response is unknown. In the present study, we sought to determine how the peripheral blood gene expression profiles of patients with bipolar disorder (BD changed over time following intitiation of treatment with lithium, and whether differences in those profiles over time were related to the clinical response. Methods Illumina Sentrix Beadchip (Human-6v2 microarrays containing > 48,000 transcript probes were used to measure levels of expression of gene-expression in peripheral blood from 20 depressed subjects with BD prior to and every two weeks during 8 weeks of open-label treatment with lithium. Changes in gene-expression were compared between treatment responders (defined as a decrease in the Hamilton Depression Rating Scale of 50% or more and non-responders. Pathway analysis was conducted using GeneGO Metacore software. Results 127 genes showed a differential response in responders vs. non-responders. Pathway analysis showed that regulation of apoptosis was the most significantly affected pathway among these genes. Closer examination of the time-course of changes among BCL2 related genes showed that in lithium-responders, one month after starting treatment with lithium, several anti-apoptotic genes including Bcl2 and insulin receptor substrate 2 (IRS2 were up-regulated, while pro-apoptotic genes, including BCL2-antagonist/killer 1 (BAK1 and BCL2-associated agonist of cell death (BAD, were down-regulated. In contrast, in lithium non-responders, BCL2 and IRS2 were down-regulated, while BAK1 and BAD up-regulated at the one-month time-point. Conclusions These results suggest that differential changes in the balance of pro- and anti- apoptotic gene-expression following treatment with lithium may explain some of

  1. rAd-p53 enhances the sensitivity of human gastric cancer cells to chemotherapy

    Institute of Scientific and Technical Information of China (English)

    Guang-Xia Chen; Li-Hong Zheng; Shi-Yu Liu; Xiao-Hua He

    2011-01-01

    AIM:To investigate potential antitumor effects of rAd-p53 by determining if it enhanced sensitivity of gastric cancer cells to chemotherapy.METHODS:Three gastric cancer cell lines with distinct levels of differentiation were treated with various doses of rAd-p53 alone,oxaliplatin (OXA) alone,or a combination of both.Cell growth was assessed with an 3-(4,5)-dimethylthiahiazo (-z-yl)-3,5-diphenytetrazoli-umromide assay and the expression levels of p53,Bax and Bcl-2 were determined by immunohistochemistry.The presence of apoptosis and the expression of cas-pase-3 were determined using flow cytometry.RESULTS:Treatment with rAd-p53 or OXA alone inhibited gastric cancer cell growth in a time- and dose-dependent manner;moreover,significant synergistic effects were observed when these treatments were combined.Immunohistochemical analysis demonstrated that treatment with rAd-p53 alone,OXA alone or combined treatment led to decreased Bcl-2 expression and increased Bax expression in gastric cancer cells.Furthermore,flow cytometry showed that rAd-p53 alone,OXA alone or combination treatment induced apoptosis of gastric cancer cells,which was accompanied by increased expression of caspase-3.CONCLUSION:rAd-p53 enhances the sensitivity of gastric cancer cells to chemotherapy by promoting apoptosis.Thus,our results suggest that p53 gene therapy combined with chemotherapy represents a novel avenue for gastric cancer treatment.

  2. Analysis of p53 gene mutations in human gliomas by polymerase chain reaction-based single-strand conformation polymorphism and DNA sequencing.

    Science.gov (United States)

    Sarkar, F H; Kupsky, W J; Li, Y W; Sreepathi, P

    1994-03-01

    Mutations in the p53 gene have been recognized in brain tumors, and clonal expansion of p53 mutant cells has been shown to be associated with glioma progression. However, studies on the p53 gene have been limited by the need for frozen tissues. We have developed a method utilizing polymerase chain reaction (PCR) for the direct analysis of p53 mutation by single-strand conformation polymorphism (SSCP) and by direct DNA sequencing of the p53 gene using a single 10-microns paraffin-embedded tissue section. We applied this method to screen for p53 gene mutations in exons 5-8 in human gliomas utilizing paraffin-embedded tissues. Twenty paraffin blocks containing tumor were selected from surgical specimens from 17 different adult patients. Tumors included six anaplastic astrocytomas (AAs), nine glioblastomas (GBs), and two mixed malignant gliomas (MMGs). The tissue section on the stained glass slide was used to guide microdissection of an unstained adjacent tissue section to ensure > 90% of the tumor cell population for p53 mutational analysis. Simultaneously, microdissection of the tissue was also carried out to obtain normal tissue from adjacent areas as a control. Mutations in the p53 gene were identified in 3 of 17 (18%) patients by PCR-SSCP analysis and subsequently confirmed by PCR-based DNA sequencing. Mutations in exon 5 resulting in amino acid substitution were found in one thalamic AA (codon 158, CGC > CTT: Arg > Leu) and one cerebral hemispheric GB (codon 151, CCG > CTG: Pro > Leu).(ABSTRACT TRUNCATED AT 250 WORDS)

  3. CEPO调控新生大鼠缺氧缺血性脑损伤Bcl-2、Bax基因表达的研究%Effect of CEPO on the expression of Bcl-2 and Bax genes in hypoxic ischemic brains of neonatal

    Institute of Scientific and Technical Information of China (English)

    付中秋; 姚笠; 田执梁; 张玉晶; 邵庆亮; 张海涛; 赵霞霞

    2014-01-01

    Objective To investigated the association between the expressions of Bcl-2 and Bax genes in neonatal rats upon cerebral hypoxic-ischemia and the effects of Carbamylated Erythropoietin (CEPO.) administration on both genes.Methods An animal model of neonatal hypoxic-ischemia brain damage was established.The changes of Bcl-2 and Bax mRNAs in brain tissues were detected in rats after HI or CEPO administration by RT-PCR.Results The levels of Bcl-2 and Bax mRNAs were increased upon HIBD compared with sham-operated group at 2 h,12 h,24 h,48 h,72 h time points post treatment (P < 0.05).On the contrary,only the level of Bcl-2 mRNA was increased (P < 0.05) while the level of Bax mRNA was decreased (P < 0.05) in CEPOintervention group.Conclusion The levels of Bcl-2 and Bax mRNAs in HIBD of neonatal rats were altered.CEPO may exert some neuroprotective effects on the brain tissues via interventing the expression of Bcl-2 and Bax.%目的 观察新生大鼠缺氧缺血性脑损伤(HIBD)脑组织Bcl-2、Bax基因表达变化及氨基甲酰化促红细胞生成素(CEPO)干预对其表达的影响,探讨CEPO发挥脑保护作用的可能机制.方法 将新生7日龄SD大鼠建立HIBD模型,利用RT-PCR检测缺氧缺血和CEPO干预后2h、12h、24 h、48 h、72 h凋亡基因Bcl-2、Bax的mRNA表达的改变.结果 与假手术组相比,缺氧缺组在2h、12h、24 h、48 h、72 h脑组织中Bcl-2、Bax的表达均增加(P<0.05),与缺氧缺血组相比,CEPO干预组在不同时间点Bcl-2表达增加(P<0.05),Bax表达下降(P<0.05).结论 在新生大鼠HIBD中Bcl-2、Bax mRNA的表达发生改变,调控二者的表达水平可能是CEPO发挥脑保护的作用机制之一.

  4. Expression of bax and bcl2 Genes in MDMA-induced Hepatotoxicity on Rat Liver Using Quantitative Real-Time PCR Method through Triggering Programmed Cell Death

    OpenAIRE

    2015-01-01

    Background: 3-4methylenedioxymethamphetamine (MDMA) is a synthetic and psychoactive drug, which is known popularly as Ecstasy and has toxic effects on human organs. Objectives: Considering the potential toxic interaction, this study was performed to quantify the expression of bax and bcl2 genes in MDMA-induced hepatotoxicity on rat liver. Subsequently, we evaluated pentoxifylline as a possible protective drug on hepatotoxicity. Materials and Methods: Adult male Wistar rats weighting 250 - 300...

  5. Phorate-induced oxidative stress, DNA damage and transcriptional activation of p53 and caspase genes in male Wistar rats

    Energy Technology Data Exchange (ETDEWEB)

    Saquib, Quaiser [Department of Zoology, College of Science, King Saud University, Riyadh (Saudi Arabia); Attia, Sabry M. [Department of Pharmacology, College of Pharmacy, King Saud University, Riyadh (Saudi Arabia); Siddiqui, Maqsood A. [Department of Zoology, College of Science, King Saud University, Riyadh (Saudi Arabia); Aboul-Soud, Mourad A.M. [Department of Zoology, College of Science, King Saud University, Riyadh (Saudi Arabia); Biochemistry Department, Faculty of Agriculture, Cairo University, 12613 Giza (Egypt); Al-Khedhairy, Abdulaziz A. [Department of Zoology, College of Science, King Saud University, Riyadh (Saudi Arabia); Giesy, John P. [Department of Zoology, College of Science, King Saud University, Riyadh (Saudi Arabia); Department of Biomedical and Veterinary Biosciences and Toxicology Centre, University of Saskatchewan, Saskatoon, Canada S7N 5B3 (Canada); Zoology Department and Center for Integrative Toxicology, Michigan State University, East Lansing 48824 (United States); Musarrat, Javed, E-mail: musarratj1@yahoo.com [Department of Zoology, College of Science, King Saud University, Riyadh (Saudi Arabia); Department of Microbiology, Faculty of Agricultural Sciences, AMU, Aligarh (India)

    2012-02-15

    Male Wistar rats exposed to a systemic organophosphorus insecticide, phorate [O,O-diethyl S-[(ethylthio) methyl] phosphorothioate] at varying oral doses of 0.046, 0.092 or 0.184 mg phorate/kg bw for 14 days, exhibited substantial oxidative stress, cellular DNA damage and activation of apoptosis-related p53, caspase 3 and 9 genes. The histopathological changes including the pyknotic nuclei, inflammatory leukocyte infiltrations, renal necrosis, and cardiac myofiber degeneration were observed in the liver, kidney and heart tissues. Biochemical analysis of catalase and glutathione revealed significantly lesser activities of antioxidative enzymes and lipid peroxidation in tissues of phorate exposed rats. Furthermore, generation of intracellular reactive oxygen species and reduced mitochondrial membrane potential in bone marrow cells confirmed phorate-induced oxidative stress. Significant DNA damage was measured through comet assay in terms of the Olive tail moment in bone marrow cells of treated animals as compared to control. Cell cycle analysis also demonstrated the G{sub 2}/M arrest and appearance of a distinctive SubG{sub 1} peak, which signified induction of apoptosis. Up-regulation of tumor suppressor p53 and caspase 3 and 9 genes, determined by quantitative real-time PCR and enzyme-linked immunosorbent assay, elucidated the activation of intrinsic apoptotic pathways in response to cellular stress. Overall, the results suggest that phorate induces genetic alterations and cellular toxicity, which can adversely affect the normal cellular functioning in rats. -- Highlights: ► This is the first report on molecular toxicity of phorate in an in vivo test system. ► Phorate induces biochemical and histological changes in liver, kidney and heart. ► Rats treated with phorate exhibited DNA damage in bone marrow cells. ► Phorate induces apoptosis, oxidative stress and alters mitochondrial fluorescence. ► Phorate induces transcriptional changes and enhanced

  6. Basal and copper-induced expression of metallothionein isoform 1,2 and 3 genes in epithelial cancer cells: The role of tumor suppressor p53.

    Science.gov (United States)

    Ostrakhovitch, E A; Song, Y P; Cherian, M G

    2016-05-01

    Metallothioneins (MTs) are a ubiquitous low-molecular weight, cysteine rich proteins with a high affinity for metal ions. The expression and induction of MTs have been associated with protection against DNA damage, oxidative stress, and apoptosis. Our past research had shown that p53 is an important factor in metal regulation of MTs. The present study was undertaken to explore further the interrelationship between p53 and MTs. We investigated whether silencing of p53 could affect expression pattern of basal and copper induced metallothioneins. The silencing of wild-type p53 (wt-p53) in epithelial breast cancer MCF7 cells affected the basal level of MT-2A RNA, whereas the levels of MT-1A and MT-1X RNA remained largely unchanged. The expression of MT-3 was undetectable in MCF7 with either functional or silenced p53. MCF7 cells with silenced wt-p53 failed to upregulate MT-2A in response to copper and showed a reduced sensitivity toward copper induced cell apoptotic death. Similarly in MCF7-E6 and MDA-MB-231 cells, the presence of inactive/mutated p53 halted MT-1A and MT-2A gene expression in response to copper. Constitutive expression of MT-3 RNA was detectable in the presence of mutated p53 (mtp53). Transient transfection of MDA-MB-231 cells with wt-p53 enabled copper induced upregulation of both MT-1A and MT-2A but not basal level of MT-2A, MT-1E, MT-1X and MT-3. Inactivation of p53 in HepG2 cells amplified the basal expression of studied MT isoforms, including MT-3, as well as copper-induced mRNA expression of MTs except MT-1H and MT-3. Presented data demonstrate a direct relation between p53 and MT-1A and MT-2A and they also indicate that wt-p53 might be a negative regulator of MT-3 in epithelial cancer cells.

  7. Inhibition of NF-κB, Bcl-2 and COX-2 Gene Expression by an Extract of Eruca sativa Seeds during Rat Mammary Gland Carcinogenesis.

    Science.gov (United States)

    Abdel-Rahman, Salah; Shaban, Nadia; Haggag, Amany; Awad, Doaa; Bassiouny, Ahmad; Talaat, Iman

    2015-01-01

    The effect of Eruca sativa seed extract (SE) on nuclear factor kappa B (NF-κB), cyclooxygenase-2 (COX-2) and B-cell lymphoma-2 (Bcl-2) gene expression levels was investigated in rat mammary gland carcinogenesis induced by 7,12 dimethylbenz(α)anthracene (DMBA). DMBA increased NF-κB, COX-2 and Bcl-2 gene expression levels and lipid peroxidation (LP), while, decreased glutathione-S-transferase (GST) and superoxide dismutase (SOD) activities and total antioxidant concentration (TAC) compared to the control group. After DMBA administration, SE treatment reduced NF-κB, COX-2 and Bcl-2 gene expression levels and LP. Hence, SE treatment reduced inflammation and cell proliferation, while increasing apoptosis, GST and SOD activities and TAC. Analysis revealed that SE has high concentrations of total flavonoids, triterpenoids, alkaloids and polyphenolic compounds such as gallic, chlorogenic, caffeic, 3,4-dicaffeoyl quinic, 3,5-dicaffeoyl quinic, tannic, cinnamic acids, catechin and phloridzin. These findings indicate that SE may be considered a promising natural product from cruciferous vegetables against breast cancer, especially given its high antioxidant properties.

  8. Arginine methylation regulates the p53 response

    DEFF Research Database (Denmark)

    Jansson, Martin; Durant, Stephen T; Cho, Er-Chieh;

    2008-01-01

    on the p53 response. We show that the protein arginine methyltransferase (PRMT) 5, as a co-factor in a DNA damage responsive co-activator complex that interacts with p53, is responsible for methylating p53. Arginine methylation is regulated during the p53 response and affects the target gene specificity......Activation of the p53 tumour suppressor protein in response to DNA damage leads to apoptosis or cell-cycle arrest. Enzymatic modifications are widely believed to affect and regulate p53 activity. We describe here a level of post-translational control that has an important functional consequence...

  9. 转染 p53基因对肺腺癌细胞株裸鼠 移植瘤生长的影响%Study on the Role of p53 Gene Transfer on Human Glandular Lung Cancer Cell Growth in Nude Mice

    Institute of Scientific and Technical Information of China (English)

    李萍; 王北宁; 丁振若

    2001-01-01

    Objective: This study was designed to explore the significance and the role of wild-type p53 (wt-p53) gene and mutant p53 gene(mt-p53) transfer on human glandular lung cancer cell growth in nude mice. Methods: wt-p53 gene and mt-p53 gene were transfected and lipofectin-mediated into the human glandular lung cancer cell line GLC-82. And the growth of gene-transfected cell lines were observed in vitro and in vivo. Results: The colony number in the colong-forming experiment and the volume and weight in nude mice were greater in the mf-p53 tranfecting cells group than in the control group. The tumor resulting from the cells transfected with the wt-p53 gene grew more slowly and was smaller than that from control GLC-82 cells. In contrast, the tumor from the cells transfected with the mt-p53 gene grew faster than that produced by cells transfeted with the wt-p53 gene and that produced by control GLC-82 cells. Conclusion: The wild-type p53 gene could inhibit the glandular lung cancer cell growth in nude mice and the mutant p53 gene could enhance the glandular lung cancer cell growth in nude mice.%目的:探讨转染野生型 p53( wt-p53)和突变型 p53( mt-p53)基因对人肺腺癌细胞株 GLC-82裸鼠移植瘤生长的影响。方法:采用脂质体介导法,分别将 wt-p53和 mt-p53基因导入人肺腺癌细胞株 GLC-82,在裸鼠体内、体外实验中检测转导细胞的生长状况和裸鼠致瘤性。结果:转染 mt-p53 基因的细胞株 G418筛选的细胞集落数、 3H-TDR掺入实验、软琼脂平皿细胞集落数,以及裸鼠瘤组织重量和体积均高于对照组( P<0.01),而转染 wt p53基因的细胞株均显著低于对照组( P< 0.01),表明导入 wt p53基因的细胞株瘤细胞生长速度明显低于对照组细胞株和导入 mt p53基因的细胞株,即导入 mt p53基因的细胞株瘤细胞生长速度最快,而导入 wt p53基因的细胞株瘤细胞

  10. Insertional mutagenesis and deep profiling reveals gene hierarchies and a Myc/p53-dependent bottleneck in lymphomagenesis.

    Science.gov (United States)

    Huser, Camille A; Gilroy, Kathryn L; de Ridder, Jeroen; Kilbey, Anna; Borland, Gillian; Mackay, Nancy; Jenkins, Alma; Bell, Margaret; Herzyk, Pawel; van der Weyden, Louise; Adams, David J; Rust, Alistair G; Cameron, Ewan; Neil, James C

    2014-02-01

    Retroviral insertional mutagenesis (RIM) is a powerful tool for cancer genomics that was combined in this study with deep sequencing (RIM/DS) to facilitate a comprehensive analysis of lymphoma progression. Transgenic mice expressing two potent collaborating oncogenes in the germ line (CD2-MYC, -Runx2) develop rapid onset tumours that can be accelerated and rendered polyclonal by neonatal Moloney murine leukaemia virus (MoMLV) infection. RIM/DS analysis of 28 polyclonal lymphomas identified 771 common insertion sites (CISs) defining a 'progression network' that encompassed a remarkably large fraction of known MoMLV target genes, with further strong indications of oncogenic selection above the background of MoMLV integration preference. Progression driven by RIM was characterised as a Darwinian process of clonal competition engaging proliferation control networks downstream of cytokine and T-cell receptor signalling. Enhancer mode activation accounted for the most efficiently selected CIS target genes, including Ccr7 as the most prominent of a set of chemokine receptors driving paracrine growth stimulation and lymphoma dissemination. Another large target gene subset including candidate tumour suppressors was disrupted by intragenic insertions. A second RIM/DS screen comparing lymphomas of wild-type and parental transgenics showed that CD2-MYC tumours are virtually dependent on activation of Runx family genes in strong preference to other potent Myc collaborating genes (Gfi1, Notch1). Ikzf1 was identified as a novel collaborating gene for Runx2 and illustrated the interface between integration preference and oncogenic selection. Lymphoma target genes for MoMLV can be classified into (a) a small set of master regulators that confer self-renewal; overcoming p53 and other failsafe pathways and (b) a large group of progression genes that control autonomous proliferation in transformed cells. These findings provide insights into retroviral biology, human cancer genetics

  11. Insertional mutagenesis and deep profiling reveals gene hierarchies and a Myc/p53-dependent bottleneck in lymphomagenesis.

    Directory of Open Access Journals (Sweden)

    Camille A Huser

    2014-02-01

    Full Text Available Retroviral insertional mutagenesis (RIM is a powerful tool for cancer genomics that was combined in this study with deep sequencing (RIM/DS to facilitate a comprehensive analysis of lymphoma progression. Transgenic mice expressing two potent collaborating oncogenes in the germ line (CD2-MYC, -Runx2 develop rapid onset tumours that can be accelerated and rendered polyclonal by neonatal Moloney murine leukaemia virus (MoMLV infection. RIM/DS analysis of 28 polyclonal lymphomas identified 771 common insertion sites (CISs defining a 'progression network' that encompassed a remarkably large fraction of known MoMLV target genes, with further strong indications of oncogenic selection above the background of MoMLV integration preference. Progression driven by RIM was characterised as a Darwinian process of clonal competition engaging proliferation control networks downstream of cytokine and T-cell receptor signalling. Enhancer mode activation accounted for the most efficiently selected CIS target genes, including Ccr7 as the most prominent of a set of chemokine receptors driving paracrine growth stimulation and lymphoma dissemination. Another large target gene subset including candidate tumour suppressors was disrupted by intragenic insertions. A second RIM/DS screen comparing lymphomas of wild-type and parental transgenics showed that CD2-MYC tumours are virtually dependent on activation of Runx family genes in strong preference to other potent Myc collaborating genes (Gfi1, Notch1. Ikzf1 was identified as a novel collaborating gene for Runx2 and illustrated the interface between integration preference and oncogenic selection. Lymphoma target genes for MoMLV can be classified into (a a small set of master regulators that confer self-renewal; overcoming p53 and other failsafe pathways and (b a large group of progression genes that control autonomous proliferation in transformed cells. These findings provide insights into retroviral biology, human cancer

  12. Ethylenediamine functionalized-single-walled nanotube (f-SWNT-assisted in vitro delivery of the oncogene suppressor p53 gene to breast cancer MCF-7 cells

    Directory of Open Access Journals (Sweden)

    Karmakar A

    2011-05-01

    Full Text Available Alokita Karmakar2, Stacie M Bratton1, Enkeleda Dervishi2, Anindya Ghosh3, Meena Mahmood2, Yang Xu2, Lamya Mohammed Saeed2, Thikra Mustafa2, Dan Casciano2, Anna Radominska-Pandya1, Alexandru S Biris21Biochemistry Department, University of Arkansas for Medical Sciences; 2Nanotechnology Center, Applied Science Department; 3Department of Chemistry, University of Arkansas, Little Rock, AR, USAAbstract: A gene delivery concept based on ethylenediamine-functionalized single-walled carbon nanotubes (f-SWCNTs using the oncogene suppressor p53 gene as a model gene was successfully tested in vitro in MCF-7 breast cancer cells. The f-SWCNTs-p53 complexes were introduced into the cell medium at a concentration of 20 µg mL-1 and cells were exposed for 24, 48, and 72 hours. Standard ethidium bromide and acridine orange assays were used to detect apoptotic cells and indicated that a significantly larger percentage of the cells (approx 40% were dead after 72 hours of exposure to f-SWCNTs-p53 as compared to the control cells, which were exposed to only p53 or f-SWCNTs, respectively. To further support the uptake and expression of the genes within the cells, green fluorescent protein-tagged p53, attached to the f-SWCNTs was added to the medium and the complex was observed to be strongly expressed in the cells. Moreover, caspase 3 activity was found to be highly enhanced in cells incubated with the f-SWCNTs-p53 complex, indicating strongly induced apoptosis. This system could be the foundation for novel gene delivery platforms based on the unique structural and morphological properties of multi-functional nanomaterials.Keywords: carbon nanotubes, gene delivery, cancer cells, p53 oncogene suppressor

  13. Distinct pattern of allelic loss and inactivation of cadherin 1 and 5 genes in mammary carcinomas arising in p53+/- mice

    International Nuclear Information System (INIS)

    p53 is one of the most frequently mutated genes in mammary carcinomas (MCs). To detect tumor suppressor genes cooperating with a hetero-deficient p53 gene in mammary carcinogenesis, we first examined allelotypes in MCs from (BALB/cHeA x MSM/Ms) F1-p53+/- and (BALB/cHeA x 129/SvEv) F1-p53+/- female mice, and then surveyed down-regulated genes in the allelic loss regions. Genome-wide screening at 42 loci identified frequent (more than 30%) loss of heterozygosity (LOH) on chromosomes 5, 8, 11, 12, 14 and 18 in the MCs from either of the F1 mice. The MCs in the p53+/- mice indicated highly frequent LOH, especially on chromosomes 8, 11 and 12, distinct from other mouse tumors. More than 60% of the 38 MCs from (BALB/cHeA x MSM/Ms) F1-p53+/- mice showed LOH in a region ranging from D8Mit85 (105.0 Mb from centromere) to D8Mit113 (111.8 Mb) on chromosome 8, a region syntenic to human chromosome 16q22.1, on which LOH has been found in breast cancers. RT-PCR analyses revealed that the LOH of chromosome 8 was associated with the reduced and/or complete loss of expression of Cdh1 and Cdh5 genes in 15 (58%) and 8 (31%) of 26 MCs derived from the F1 mice, respectively. Thus, inactivation of Cdh1 and Cdh5 is likely to cooperate with the loss of p53, suggesting a possible tumor suppressive function of these genes in mammary carcinogenesis. (author)

  14. Mutations in and Expression of the Tumor Suppressor Gene p53 in Egg-Type Chickens Infected With Subgroup J Avian Leukosis Virus.

    Science.gov (United States)

    Yue, Q; Yulong, G; Liting, Q; Shuai, Y; Delong, L; Yubao, L; Lili, J; Sidang, L; Xiaomei, W

    2015-11-01

    To investigate the molecular mechanisms of the oncogenic effects of avian leukosis virus subgroup J (ALV-J), we examined mutations in and the expression of p53 in the myelocytomas distributed in the liver, spleen, trachea, and bone marrow, as well as in fibrosarcomas in the abdominal cavity and hemangiomas in skin from chickens that were naturally or experimentally infected with ALV-J. Two types of mutations in the p53 gene were detected in myelocytomas of both the experimentally infected and the naturally infected chickens and included point mutations and deletions. Two of the point mutations have not been reported previously. Partial complementary DNA clones with a 122-bp deletion in the p53 gene ORF and a 15-bp deletion in the C-terminus were identified in the myelocytomas. In addition, moderate expression of the mutant p53 protein was detected in the myelocytomas that were distributed in the liver, trachea, spleen, and bone marrow. Mutant p53 protein was not detected in the subcutaneous hemangiomas or in the abdominal fibrosarcomas associated with natural and experimental ALV-J infection, respectively. These results identify mutations associated with abnormal expression of p53 in ALV-J-associated myelocytomas, suggesting a role in tumorigenesis.

  15. Wild Type p53 gene sensitizes rat C6 glioma cells to HSV-TK/ACV treatment in vitro and in vivo.

    Science.gov (United States)

    Huang, Qiang; Xia, Zhibo; You, Yongping; Pu, Peiyu

    2010-12-01

    Suicide gene therapy using herpes simplex virus-thymidine kinase (HSV-TK)/ganciclovir (GCV), has been extensively tested for the treatment of glioma. Our previous study showed that exogenous wild type p53 (wt-p53) enhanced the anti-tumor effect of HSV-TK/GCV therapy. However, the use of GCV is hindered by its low penetration to the brain and its toxicity when used at higher dose. In the present study, we used another pro-drug, acyclovir (ACV), and examined the therapeutic efficacy of HSV-TK/ACV combining with wt-p53 in C6 glioma cells. We observed that wt-p53 combined with HSV-TK/ACV resulted in the super-additive anti-tumor effect in vitro. Exogenous wt-p53 significantly enhanced the sensitivity of TK positive C6 cells to ACV in vitro. Our in vivo experiment demonstrated that the effect of wt-p53 and HSV-TK/ACV combination therapy was better than that of HSV-TK/ACV alone. The survival time of tumor-bearing rats treated with wt-p53 in combination with HSV-TK/ACV was also significantly prolonged than those treated with HSV-TK/ACV alone. These results suggest that wt-p53 can enhance the therapeutic efficacy of HSV-TK/ACV both in vitro and in vivo. These findings are considerably valuable with the respect of using less toxic ACV as prodrug. This novel strategy could provide benefit to HSV-TK/prodrug gene therapy.

  16. Clinical Significance of P53 gene in Serum and Stool of Patients with Colorectal Cancer%结直肠癌患者血清及粪便中P53基因检测的临床意义

    Institute of Scientific and Technical Information of China (English)

    欧玉荣; 张洪福; 刘德纯

    2005-01-01

    背景与目的:研究大肠癌患者血清P53-Ab、粪便P53基因突变与癌组织中P53蛋白表达之间关系,以探讨P53基因在大肠癌发生与早期诊断中的作用及临床意义.材料与方法:运用酶联免疫吸附分析(Enzyme-linked immunosorbent assay,ELISA)法检测34例大肠癌患者及10例健康人血清P53-Ab,运用聚合酶链反应-单链构象多态性分析(Polymerase chain reaction-single strandconformation polymorphism,PCR-SSCP)分析16例大肠癌患者粪便P53基因第5~8外显子突变,同时运用PCR-SSCP与免疫组化法分析癌组织中P53基因突变及蛋白表达状况.结果:大肠癌中血清P53-Ab阳性率为17.6%,正常对照组为阴性.癌组织中P53基因突变率及蛋白表达率分别为52.9%和55.9%,正常黏膜未见P53基因突变及蛋白表达.16例P53基因突变的患者其粪便中基因突变率为43.8%.P53基因突变及蛋白表达与P53-Ab存在及临床病理因素无关.结论:P53基因突变是参与和影响P53蛋白表达的主要因素,P53蛋白表达可诱导P53-Ab产生.大肠癌患者粪便中可检测出P53基因突变,粪便P53基因及血清P53-Ab检测可有助于大肠癌的诊断及高危人群的筛检普查.

  17. p53 Acetylation: Regulation and Consequences

    OpenAIRE

    Reed, Sara M.; Quelle, Dawn E.

    2014-01-01

    Post-translational modifications of p53 are critical in modulating its tumor suppressive functions. Ubiquitylation, for example, plays a major role in dictating p53 stability, subcellular localization and transcriptional vs. non-transcriptional activities. Less is known about p53 acetylation. It has been shown to govern p53 transcriptional activity, selection of growth inhibitory vs. apoptotic gene targets, and biological outcomes in response to diverse cellular insults. Yet recent in vivo ev...

  18. Pax-8基因敲除小鼠心脏中Bcl2l14基因表达上调%Up-regulation of Bcl2l14 gene in myocardium of Pax-8 gene knockout mouse

    Institute of Scientific and Technical Information of China (English)

    高瞻; 来丹丹; 黄晓燕; 褚茂平; 施翔翔; 张怀勤; 杨德业

    2010-01-01

    目的:寻找先天性心脏病相关基因-转录因子Pax-8的下游基因.方法:分别提取Pax-8基因敲除小鼠纯合子(Pax-8 KO~(-/-))和杂合子(Pax-8 KO~(+/-))的心脏总RNA,利用含31 802个小鼠基因的基因芯片检测两组小鼠基因表达水平,找出差异表达的基因,并经半定量RT-PCR和荧光实时定量PCR技术初步筛选出转录因子Pax-8的下游基因.结果:基因芯片检测发现,Pax-8 KO~(-/-) 组与Pax-8 KO~(+/-) 相比有25个基因表达下调,另有17个基因表达上调,差异基因涉及细胞周期及信号转导的调节因子,直接参与代谢的酶,以及核转录因子等.用半定量RT-PCR验证发现:Bcl2-like 14(Bcl2l14)基因在Pax-8 KO~(-/-) 组上调.定量RT-PCR亦证实在Pax-8 KO~(-/-)组Bcl2l14基因的表达水平较Pax-8 KO~(+/-) 组及Pax-8 KO~(+/+)(野生型)组分别上调2.07倍和2.23倍(P<0.01).结论:Bcl2l14基因为转录因子Pax-8的下游基因,可能在先天性心脏病室间隔缺损的发病机制中发挥重要作用.

  19. The influence of p53 gene 245 site mutation to human lung adenocarcinoma cell line H1299%p53基因245位点突变对非小细胞肺癌细胞H1299的影响

    Institute of Scientific and Technical Information of China (English)

    王蕊; 宫兆华; 姜立新; 孙等军; 矫爱红; 陈剑; 张良明

    2011-01-01

    Background and purpose: The mutation of thc p53 gene could bca common molccular biological event during the process of lung adenocarcinoma because 245 site was a hot site for p53 gene mutation.A study of 245 site's mutation of p53 may provide the basic theories for the diagnosis and treatment for lung adenocarcinoma.This study aimed to investigate the influence of p53 245 site's mutation on p53-deficient human lung cancer H1299 cell line in vitro.Methods: H1299 cells were transiently transfected with wide type p53 and G245V p53 plasmid.Flow cytometry was performed for cell apoptosis analysis.H1299 cells were also stably transfected with wide type p53 and G245V p53 plasmid.The G418-selected cells were assayed for colony-forming efficiency, and the transfected cells were examined using MTT for the purpose of drawing the growth curve and evaluazing cell growth.Results: In the experimental study of cell apoptosis, we could see that the apoptosis rate of H1299 cells transfected with G245V-p53 gene appeared significantly less than in cells transfected with wide type p53 gene (P<0.001), similar happened to those transfected with pcmv plasmid.The colony-forming efficiency showed that there were more cells transfected with G245V-p53 gene than those transfected with wide type p53 gene(P<0.05).Thc growth curve indicates that cells transfectcd with G245V-p53 gene grew faster than those transfected with wide type p53 gene.Conclusion: Wild type p53 gene loses all function when mutation happens to the site 245.%背景与目的:p53基因突变是肺腺癌发生中的常见的分子生物学事件,第245位点突变为其突变热点之一,因此研究p53基因第245位点突变可能为肺腺痛的诊断、治疗提供一定的理论基础.本研究旨在研究肺癌常见的245位点突变对p53缺失的人肺腺癌细胞系H1299的影响.方法:应用流式细胞术观察脂质体瞬时转染p53基因第245突变体(G245V)对细胞凋亡的影响,同时用稳定转染观察

  20. 非小细胞肺癌患者呼出气冷凝液中p53基因突变检测的研究%Detection of p53 gene mutation in exhaled breath condensate of patients with non-small cell lung cancer

    Institute of Scientific and Technical Information of China (English)

    陈金亮; 陈建荣; 钱春花; 蔡映云; 陶国华; 周峰; 陶一江; 陆晨希

    2011-01-01

    目的 探讨非小细胞肺癌(NSCLC)患者呼出气冷凝液(EBC)中p53基因突变检测的临床意义.方法 采用PCR结合DNA测序法,检测53例NSCLC患者(治疗前)EBC中p53基因第5、6、7、8外显子的突变情况,32名健康体检者EBC标本作为对照.结果 肺癌组(治疗前)EBC标本中扩增到p53基因26例,其中10例检测到p53基因突变,突变率为38.5%;正常对照组EBC标本中扩增到p53基因15名,均未检测到p53基因突变;肺癌患者p53基因突变率高于正常对照组(P<0.01).结论 本研究成功扩增并分析了EBC中p53基因变异,将有助于肺癌发病机制研究和临床诊断.%Objective To investigate the clinical significance of p53 gene mutation in exhaled breath condensate (EBC) of patients with non-small cell lung cancer (NSCLC). Methods The mutations of exons 5,6,7 and 8 of p53 gene in EBC of 53 patients with NSCLC and 32 healthy persons were detected hy polymerase chain reaction and DNA sequencing method. Results In NSCLC group,p53 gene of 26 cases was amplified,p53 gene mutation was found in ten cases of them,the mutation rate was 38. 5%. In control group,p53 gene of 15 cases was amplified,p53 gene mutation was not found. The mutation rate of p53 gene in NSCLC group was higher than that in control group ( P < 0. 01). Conclusions This research had successfully amplificated and analyzed p53 gene mutation in EBC,which will be helpful for pathogenesis research and clinical diagnosis of lung cancer.

  1. Wild-type p53 enhances the cytotoxic effect of radionuclide gene therapy using sodium iodide symporter in a murine anaplastic thyroid cancer model

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yong Jin [Seoul National University College of Medicine, Department of Nuclear Medicine, Chongno-gu, Seoul (Korea); Seoul National University College of Medicine, Cancer Research Institute, Chongno-gu, Seoul (Korea); Seoul National University College of Medicine, Tumor Immunity Medical Research Center, Chongno-gu, Seoul (Korea); Korea Institute of Radiological and Medical Sciences, Molecular Imaging Research Center, Nowon-Gu, Seoul (Korea); Chung, June-Key [Seoul National University College of Medicine, Department of Nuclear Medicine, Chongno-gu, Seoul (Korea); Seoul National University College of Medicine, Cancer Research Institute, Chongno-gu, Seoul (Korea); Seoul National University College of Medicine, Tumor Immunity Medical Research Center, Chongno-gu, Seoul (Korea); Kang, Joo Hyun [Korea Institute of Radiological and Medical Sciences, Molecular Imaging Research Center, Nowon-Gu, Seoul (Korea); Jeong, Jae Min [Seoul National University College of Medicine, Department of Nuclear Medicine, Chongno-gu, Seoul (Korea); Seoul National University College of Medicine, Cancer Research Institute, Chongno-gu, Seoul (Korea); Lee, Dong Soo; Lee, Myung Chul [Seoul National University College of Medicine, Department of Nuclear Medicine, Chongno-gu, Seoul (Korea)

    2010-02-15

    To evaluate the role of p53 in radionuclide gene therapy, we investigated the cytotoxic effect of {sup 131}I and {sup 188}Re following cotransfection of the sodium iodide symporter (NIS) and wild-type p53 (wt-p53) genes into cancer cells. The NIS gene was transfected to human anaplastic thyroid carcinoma cells (ARO) expressing mutant p53 (mt-p53) using liposomes. The uptakes of {sup 125}I and {sup 188}Re were measured in the transfected (ARO-N) and wild-type cell lines (ARO). A recombinant adenovirus-5 vector containing a CMV promoter and wt-p53 cDNA, called Ad-p53, was established and transduced to ARO and ARO-N cells. After incubating cells with {sup 131}I and {sup 188}Re, the survival rate of each cell line was measured using a clonogenic assay. For radionuclide gene therapy in an animal model, Ad-p53 was injected directly into ARO and ARO-N tumours which were transplanted to nude mice. Two days later, {sup 188}Re or saline was injected intraperitoneally into the mice, and the tumours were measured using a calliper for 4 weeks. In ARO-N cells, the uptakes of {sup 125}I and {sup 188}Re were 505.16{+-}21.30 pmol/10{sup 6} cells and 13,875.20{+-}504.85 cpm/10{sup 6} cells at 30 min, respectively. There was no difference between the survival rates of ARO cells and ARO-N cells after incubation with {sup 131}I or {sup 188}Re. When Ad-p53 was transduced to ARO-N cells, the survival rate of wt-p53-expressing ARO-N cells incubated with {sup 131}I (18.5 MBq/5 ml) and {sup 188}Re (18.5 MBq/5 ml) decreased to 48.8{+-}18.4% and 32.6{+-}23.5%, respectively. In the nude mice experiment, ARO and ARO-N tumours gradually grew up to six to eight times larger than the initial volume. ARO and ARO-N tumours transduced with Ad-p53 continued to grow. However, the ARO-N tumours treated with Ad-p53 and 185 MBq of {sup 188}Re regressed to 20% of the initial volume. Growth of ARO-N tumour treated with {sup 131}I or {sup 188}Re was significantly inhibited by Ad-p53 transduction in vivo as

  2. p53 Acetylation: Regulation and Consequences

    Energy Technology Data Exchange (ETDEWEB)

    Reed, Sara M. [Department of Pharmacology, The University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States); Medical Scientist Training Program, The University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States); Quelle, Dawn E., E-mail: dawn-quelle@uiowa.edu [Department of Pharmacology, The University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States); Medical Scientist Training Program, The University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States); Department of Pathology, The University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States)

    2014-12-23

    Post-translational modifications of p53 are critical in modulating its tumor suppressive functions. Ubiquitylation, for example, plays a major role in dictating p53 stability, subcellular localization and transcriptional vs. non-transcriptional activities. Less is known about p53 acetylation. It has been shown to govern p53 transcriptional activity, selection of growth inhibitory vs. apoptotic gene targets, and biological outcomes in response to diverse cellular insults. Yet recent in vivo evidence from mouse models questions the importance of p53 acetylation (at least at certain sites) as well as canonical p53 functions (cell cycle arrest, senescence and apoptosis) to tumor suppression. This review discusses the cumulative findings regarding p53 acetylation, with a focus on the acetyltransferases that modify p53 and the mechanisms regulating their activity. We also evaluate what is known regarding the influence of other post-translational modifications of p53 on its acetylation, and conclude with the current outlook on how p53 acetylation affects tumor suppression. Due to redundancies in p53 control and growing understanding that individual modifications largely fine-tune p53 activity rather than switch it on or off, many questions still remain about the physiological importance of p53 acetylation to its role in preventing cancer.

  3. The effects of combining ionizing radiation and adenoviral p53 therapy in nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Purpose: Nasopharyngeal carcinoma (NPC) is a malignant disease of the head/neck region, with a 5-year survival level of approximately 65%. To explore gene therapy as a novel approach which might improve outcome, we have shown previously that introduction of human recombinant wild-type p53 mediated by the adenoviral vector (Ad5CMV-p53) was cytotoxic in two human nasopharyngeal carcinoma (NPC) cell lines (CNE-1 and CNE-2Z). The current work was designed to determine whether this strategy, combined with ionizing radiation (XRT), was more effective than either treatment alone. Methods and Materials: CNE-1, CNE-2Z, and a normal human nasopharyngeal fibroblast strain, KS1, were infected with 2- and 6-plaque-forming units (pfu)/cell of Ad5CMV-p53, respectively. These doses were iso-effective for β-galactosidase activity in the CNE-1 and CNE-2Z cells. XRT was administered 24 h post-infection, and Western blot analyses were conducted for p53, p21WAF1/CIP1, bax, and bcl-2 2 days after XRT. Cell survival was assessed using a clonogenic assay. Presence of DNA ladders reflecting apoptosis was detected using DNA agarose gel electrophoresis, and cell cycle was analyzed using flow cytometry. Results: The combination of Ad5CMV-p53 plus XRT (2, 4, and 6 Gy) resulted in an approximately 1-log greater level of cytotoxicity compared to that observed with XRT alone for both NPC cell lines. The two modalities appear to be interacting in a synergistic manner in cancer cells, but not in KS1 fibroblasts. XRT alone stimulated minimal p53 expression in control cells; Ad5CMV-p53 alone induced significant recombinant p53 expression, which was not further enhanced by the addition of XRT. Similar observations were made for p21WAF1/CIP1expression. No changes were observed for bax or bcl-2 expression with any of these treatments. Apoptosis was induced following 4 Gy of XRT alone, but was observed after only 2 Gy when combined with Ad5CMV-p53. Cell cycle analysis indicated that Ad5CMV-p53 infection

  4. Mutant p53: Multiple Mechanisms Define Biologic Activity in Cancer

    OpenAIRE

    Kim, Michael Paul; Zhang, Yun; Lozano, Guillermina

    2015-01-01

    The functional importance of p53 as a tumor suppressor gene is evident through its pervasiveness in cancer biology. The p53 gene is the most commonly altered gene in human cancer; however, not all genetic alterations are biologically equivalent. The majority of alterations involve p53 missense mutations that result in the production of mutant p53 proteins. Such mutant p53 proteins lack normal p53 function and may concomitantly gain novel functions, often with deleterious effects. Here, we rev...

  5. Evaluation of radiation effects against C6 glioma in combination with vaccinia virus-p53 gene therapy

    Science.gov (United States)

    Gridley, D. S.; Andres, M. L.; Li, J.; Timiryasova, T.; Chen, B.; Fodor, I.; Nelson, G. A. (Principal Investigator)

    1998-01-01

    The primary objective of this study was to evaluate the antitumor effects of recombinant vaccinia virus-p53 (rVV-p53) in combination with radiation therapy against the C6 rat glioma, a p53 deficient tumor that is relatively radioresistant. VV-LIVP, the parental virus (Lister strain), was used as a control. Localized treatment of subcutaneous C6 tumors in athymic mice with either rVV-p53 or VV-LIVP together with tumor irradiation resulted in low tumor incidence and significantly slower tumor progression compared to the agents given as single modalities. Assays of blood and spleen indicated that immune system activation may account, at least partly, for the enhance tumor inhibition seen with combined treatment. No overt signs of treatment-related toxicity were noted.

  6. Differences in the mutation of the p53 gene in exons 6 and 7 in cervical samples from HIV- and HPV-infected women

    OpenAIRE

    Souza, Raquel P.; Gimenes, Fabrícia; de Abreu, André LP; Rocha-Brischiliari, Sheila C; de Carvalho, Maria DB; Ferreira, Érika C; Bonini, Marcelo G; Pelloso, Sandra M; Consolaro, Marcia EL

    2013-01-01

    Background Human Papillomavirus (HPV) infection is a serious problem for human immunodeficiency virus (HIV)-infected women, increases their risk of cervical lesions and cancer. In cervical carcinogenesis, mutations in the p53 gene occur most frequently within exons 5–8. To our knowledge, no previous studies have analyzed mutations in exons 5–8 of the p53 gene in HIV- and HPV-infected women. In our study, we verified these mutations in women with and without cervical abnormalities. Findings Th...

  7. Study on the inhibition of wild-type p53 gene on cervical cancer HeLa cells%野生型p53抑制宫颈癌HeLa细胞的研究

    Institute of Scientific and Technical Information of China (English)

    林亚; 宋巧丽; 郑飞云

    2008-01-01

    目的:研究外源性野生型p53(wt p53)基因对宫颈癌HeLa细胞中的致癌基因环氧合酶-2(COX-2)的影响,以及抑制HeLa细胞生长的作用.方法:用脂质体介导的转染技术将野生型p53基因转染到HeLa细胞.实验分为2组,p53转染组(p53-HeLa组)和空白对照组(HeLa组),wt p53表达用逆转录-多聚酶链反应鉴定,并检测p53 mR-NA和COX-2 mRNA瞬时转染及稳定转染前后表达的变化.CCK-8染色法绘制细胞生长曲线.结果:野生型p53基因转染后HeLa细胞中的p53 mRNA表达增加,COX-2 mRNA表达减少.通过对细胞生长曲线的分析,转染后与转染前相比,生长明显减慢(P<0.01),wt p53对HeLa细胞有抑制作用.结论:外源性wit p53基因表达可抑制宫颈癌He-La细胞中COX-2 mRNA的表达;wt p53可能通过抑制COX-2对宫颈癌HeLa细胞产生抑制作用,进而阻碍肿瘤的生长.

  8. Evaluation of Intraductal Ultrasonography, Endoscopic Brush Cytology and K-ras, P53 Gene Mutation in the Early Diagnosis of Malignant Bile Duct Stricture

    Institute of Scientific and Technical Information of China (English)

    Ping Huang; Hao Zhang; Xiao-Feng Zhang; Xiao Zhang; Wen Lyu; Zhen Fan

    2015-01-01

    Background:In qualitative diagnosis of bile duct stenosis,single diagnostic measure is difficult to make a correct diagnosis,to combine several diagnostic techniques may be helpful to make an accurate diagnosis.The aim of this study was to evaluate the value of intraductal ultrasonography (IDUS),endoscopic brush cytology and K-ras,P53 gene mutation in the early diagnosis of malignant biliary stricture.Methods:From February 2012 to February 2013,84 patients with suspected malignant biliary stricture were performed IDUS firstly,then endoscopic brush cytology and finally K-ras,P53 gene mutation detection,the sensitivity,specificity,positive predictive value,negative predictive value and accuracy of all above ways were evaluated and compared.Results:Of 84 patients,52 cases were ultimately diagnosed malignant biliary stenosis;of which,9 cases had no recurrence or metastasis to other organs after radical operation during the follow-up period.IDUS combined with brush cytology and K-ras + P53 gene mutation detection had obvious advantage in the sensitivity,accuracy and negative predictive value than any other joint detection and single detection (the advantage was more significant compared with IDUS + brush cytology or any single detection P < 0.01).There were obvious statistical significance in the sensitivity and accuracy between IDUS + brush cytology + P53 or IDUS + brush cytology + K-ras and IDUS + brush cytology or IDUS (P < 0.05).There was no statistical significance in the sensitivity,specificity,positive predictive value,negative predictive value and accuracy between IDUS + brush cytology + P53 and IDUS + brush cytology + K-ras (P > 0.05).Conclusions:IDUS combined with brush cytology and K-ras,P53 gene mutation detection is better than the separate detection and contribute to the early diagnosis of malignant biliary stricture.Its more widespread use is recommended.

  9. A Comparison Between p73 Gene With p53 Tumor Suppressor Gene%p73基因与p53抑癌基因的比较

    Institute of Scientific and Technical Information of China (English)

    吴小明

    2003-01-01

    p53是一种肿瘤抑制基因,它的突变与50%的人类肿瘤发生有关.p73基因编码的蛋白质,无论在结构上,还是在功能及调节上均与p53蛋白相似,且与肿瘤的发生密切相关,本文对此方面的研究结果进行了比较,并对p73能否作为候选抑癌基因进行了讨论.

  10. The Study of Pentoxifylline Drug Effects on Renal Apoptosis and BCL-2 Gene Expression Changes Following Ischemic Reperfusion Injury in Rat

    OpenAIRE

    Hashemi, Mehrdad

    2014-01-01

    Ischemia Reperfusion injury is the tissue damage caused when blood supply returns to the tissue after a period of ischemia or lack of oxygen. In this study, the effect of pentoxyfylline on BCL-2 gene expression changes and cell injury in kidney of rat following Ischemia Reperfusion were evaluated. In this experimental study, 20 male wistar rats with average weight of 250-300 g were selected and then were accidently divided them on two tenth group of control and treatment groups. In the contro...

  11. Immunohistochemical analysis of p53, cyclinD1, RB1, c-fos and N-ras gene expression in hepatocellular carcinoma in Iran

    Institute of Scientific and Technical Information of China (English)

    SJ Moghaddam; EN Haghighi; S Samiee; N Shahid; AR Keramati; S Dadgar; MR Zali

    2007-01-01

    AIM: To study the effect of some genes especially those involved in cell cycle regulation on hepatocellular carcinoma.METHODS: Paraffin-embedded tissue samples of 25 patients (18 males and 7 females) with hepatocellular carcinoma were collected from 22 pathology centers in Tehran during 2000-2001, and stained using immunohistochemistry method (avidin-biotin-peroxidase)for detection of p53, cyclinD1, RB1, c-fos and N-ras proteins.RESULTS: Six (24%), 5 (20%), 12 (48%) and 2 samples (8%) were positive for p53, cyclinD1, C-fos and N-ras expression, respectively. Twenty-two (88%) samples had alterations in the G1 cell-cycle checkpoint protein expression (RB1 or cyclinD1). P53 positive samples showed a higher (9 times) risk of being positive for RB1 protein than p53 negative samples. Loss of expression of RB1 in association with p53 over-expression was observed in 4 (66.7%) of 6 samples. Loss of expression of RB1 was seen in all cyclinD1 positive, 20 (90.9%) N-ras negative, and 11 (50%) C-fos positive samples,respectively. CyclinD1 positive samples showed a higher (2.85 and 4.75 times) risk of being positive for c-fos and N-ras expression than cyclinD1 negative samples.CONCLUSION: The expression of p53, RB1 and c-fos genes appears to have a key role in the pathogenesis of hepatocellular carcinoma in Iran. Simultaneous overexpression of these genes is significantly associated with their loss of expression during development of hepatocellular carcinoma.

  12. Bax/Bak activation in the absence of Bid, Bim, Puma, and p53.

    Science.gov (United States)

    Zhang, J; Huang, K; O'Neill, K L; Pang, X; Luo, X

    2016-01-01

    How BH3-only proteins activate Bax/Bak, the two gateway proteins of the mitochondria-dependent apoptotic pathway, remains incompletely understood. Although all pro-apoptotic BH3-only proteins are known to bind/neutralize the anti-apoptotic Bcl-2 proteins, the three most potent ones, Bid (tBid), Bim, and Puma, possess an additional activity of directly activating Bax/Bak in vitro. This latter activity has been proposed to be responsible for triggering Bax/Bak activation following apoptotic stimulation. To test this hypothesis, we generated Bid(-/)(-)Bim(-/)(-)Puma(-/)(-) (TKO), TKO/Bax(-/)(-)/Bak(-/)(-) (PentaKO), and PentaKO/Mcl-1(-/-) (HexaKO) HCT116 cells through gene editing. Surprisingly, although the TKO cells were resistant to several apoptotic stimuli, robust apoptosis was induced upon the simultaneous inactivation of Bcl-xL and Mcl-1, two anti-apoptotic Bcl-2 proteins known to suppress Bax/Bak activation and activity. Importantly, such apoptotic activity was completely abolished in the PentaKO cells. In addition, ABT-737, a BH3 mimetic that inhibits Bcl-xL/Bcl-w/Bcl-2, induced Bax activation in HexaKO cells reconstituted with endogenous level of GFP-Bax. Further, by generating TKO/p53(-/-) (QKO) cells, we demonstrated that p53, a tumor suppressor postulated to directly activate Bax, is not required for Bid/Bim/Puma-independent Bax/Bak activation. Together, these results strongly suggest that the direct activation activities of Bid (tBid), Bim, Puma, and p53 are not essential for activating Bax/Bak once the anti-apoptotic Bcl-2 proteins are neutralized. PMID:27310874

  13. Dominant effects of Δ40p53 on p53 function and melanoma cell fate

    OpenAIRE

    Takahashi, Rie; Markovic, Svetomir; Scrable, Heidi

    2013-01-01

    The p53 gene encodes 12 distinct isoforms some of which can alter p53 activity in the absence of genomic alteration. Endogenous p53 isoforms have been identified in cancers; however, the function of these isoforms remains unclear. In melanoma, the frequency of p53 mutations is relatively low compared to other cancers suggesting that these isoforms may play a larger role in regulating p53 activity. We hypothesized that p53 function and therefore cell fate might be altered by the presence of Δ4...

  14. Expression of a constitutively active prolactin receptor causes histone trimethylation of the p53 gene in breast cancer

    Institute of Scientific and Technical Information of China (English)

    Tan Dunyong; Tang Peizhi; Huang Jianjun; Zhang Jie; Zhou Weihua; Ameae M.Walker

    2014-01-01

    Background Prolactin (PRL) is a pituitary polypeptide hormone characterized by multiple biological actions including stimulation of growth in the prostate and formation of secretory alveoli and stimulation of milk protein gene expression in the mammary gland.PRL exerts its effect by dimerizing its receptor (PRLR) on the plasma membrane and regulating gene expression through the JAK-Stat signal pathway.We have previously described a natural variant of the PRLR in which the S2 subdomain of the extracellular domain is missing (Delta S2).Delta S2 PRLRs are dimerized in the absence of PRL and have constitutive activity in the promotion of breast cancer cell growth.Enhancer of zeste homolog 2 (EZH2),as one of the histone-modifying enzymes,is a key factor regulating gene expression by epigenetic modification.We hypothesized that these constitutive activated Delta S2 PRLRs played a pathogenic role in breast cancer in part through alterations in the expression of EZH2 and the trimethylation of histone 3 on lysine 27 (H3K27Me3).Methods In order to verify the clinical significance and to establish the link between Delta S2 PRLR expression and epigenetic change,EZH2,H3K27Me3,and Delta S2 PRLR were detected in both normal and cancerous human breast tissues.Also,overexpression of Delta S2 PRLR in breast epithelial cells was achieved by infection with adenovirus carrying the cDNA.Western blotting and chromatin immunoprecipitation (ChIP assay) and acid histone extraction were applied to detect the expression of EZH2 and the trimethylation of histone 3,respectively.Results In breast tissue,higher EZH2 expression and higher H3K27Me3 were found associated with higher Delta S2 expression in breast cancer samples.In breast epithelial cells,overexpression of Delta S2 PRLR increased EZH2 methyltransferase mRNA and protein,induced EZH2 methyltransferase recruitment to chromatin,increased the trimethylation of H3K27Me3,and decreased the expression of p53 gene.Conclusions Delta S2 PRLR

  15. In situ hybridisation detects pro-apoptotic gene expression of a Bcl-2 family member in white syndrome-affected coral.

    Science.gov (United States)

    Ainsworth, T D; Knack, B; Ukani, L; Seneca, F; Weiss, Y; Leggat, W

    2015-12-01

    White syndrome has been described as one of the most prolific diseases on the Great Barrier Reef. Previously, apoptotic cell death has been described as the mechanism driving the characteristic rapid tissue loss associated with this disease, but the molecular mechanisms controlling apoptotic cell death in coral disease have yet to be investigated. In situ methods were used to study the expression patterns of 2 distinct regulators of apoptosis in Acropora hyacinthus tissues undergoing white syndrome and apoptotic cell death. Apoptotic genes within the Bcl-2 family were not localized in apparently healthy coral tissues. However, a Bcl-2 family member (bax-like) was found to localize to cells and tissues affected by white syndrome and those with morphological evidence for apoptosis. A potential up-regulation of pro-apoptotic or bax-like gene expression in tissues with apoptotic cell death adjacent to disease lesions is consistent with apoptosis being the primary cause of rapid tissue loss in coral affected by white syndrome. Pro-apoptotic (bax-like) expression in desmocytes and the basal tissue layer, the calicodermis, distant from the disease lesion suggests that apoptosis may also underlie the sloughing of healthy tissues associated with the characteristic, rapid spread of tissue loss, evident of this disease. This study also shows that in situ hybridisation is an effective tool for studying gene expression in adult corals, and wider application of these methods should allow a better understanding of many aspects of coral biology and disease pathology. PMID:26648107

  16. Papillomavirus, p53 alteration, and primary carcinoma of the vulva.

    Science.gov (United States)

    Pilotti, S; D'Amato, L; Della Torre, G; Donghi, R; Longoni, A; Giarola, M; Sampietro, G; De Palo, G; Pierotti, M A; Rilke, F

    1995-12-01

    Twenty-nine samples from 28 cases of vulvar squamous cell carcinoma, of which 13 fulfilled the criteria of the bowenoid subtype (mean age 45 years, range 31-68) and 16 of the usual subtype of invasive squamous cell carcinoma (ISCC) (mean age 67.5 years, range 34-83) were investigated for human papillomavirus (HPV) DNA, TP53 alterations, and mdm2 and bcl-2 gene product deregulation. Microscopically all the bowenoid subtype cases (group I) showed a high-grade intraepithelial (VIN 3, carcinoma in situ) lesion associated with early invasive carcinoma in six cases and overt invasive carcinoma in one. By contrast, no evidence of early carcinoma was present in the ISCCs (group II). By in situ hybridization and/or Southern blot hybridization or polymerase chain reaction (PCR), HPV DNA was detected in all cases of group I and in four of 16 cases (25%) of group II, two only by Southern blot after PCR. By single-strand conformation polymorphism and immunocytochemistry only wild-type TP53 and absence of detectable p53 product, respectively, were found in all cases of group I, i.e., in high-risk HPV-positive carcinomas, whereas mutations and/or p53 overexpression accounted for 75% in group II, i.e., in mainly HPV-negative carcinomas. The TP53 gene mutations observed in invasive carcinomas were significantly related to node-positive cases (p = 0.04). Taken together and in agreement with in vitro data, these results support the view that an alteration of TP53, gained either by interaction with viral oncoproteins or by somatic mutations, is a crucial event in the pathogenesis of vulvar carcinomas, but that TP53 mutations are mainly associated with disease progression. Finally, a preliminary immunocytochemical analysis seems to speak against the possible involvement of both MDM2 and BCL-2 gene products in the development of vulvar carcinoma.

  17. Acquisition of p53 mutations in response to the non-genotoxic p53 activator Nutlin-3

    OpenAIRE

    Aziz, Moammir H.; Shen, Hong; Carl G Maki

    2011-01-01

    Wild-type p53 is a stress-responsive tumor suppressor and potent growth inhibitor. Genotoxic stresses (e.g. ionizing and UV radiation or chemotherapeutic drug treatment) can activate p53, but also induce mutations in the P53 gene and thus select for p53-mutated cells. Nutlin-3a (Nutlin) is pre-clinical drug that activates p53 in a non-genotoxic fashion. Nutlin occupies the p53-binding pocket of MDM2, activating p53 by blocking the p53-MDM2 interaction. Because Nutlin neither binds p53 directl...

  18. Clinical study on p53 gene mutation and p53 protein expression in gastrointestinal carcinomas and peripheral tissues%胃肠恶性肿瘤及其切缘组织中p53基因突变和p5 3蛋白表达

    Institute of Scientific and Technical Information of China (English)

    李孝麟; 陈少茂; 刘东海; 张乐鸣

    2001-01-01

    目的探讨胃肠道恶性肿瘤及其切缘组织中p53基因突变和p53蛋白表达与手术切缘的安全性关系.方法用PCR-SSCP和免疫组化S-P方法检测20例胃癌和10例大肠癌标本和切缘组织中p53基因突变和p53蛋白表达情况.结果(1)胃肠道恶性肿瘤组织中有很高的p53基因突变率(63%)和p53蛋白阳性表达率(53.33%).(2)肿瘤组织中p53蛋白表达是切缘组织中p53蛋白表达的前提.(3)p53基因突变和p53蛋白表达随肿瘤切缘距离的增加而呈现极显著的递减趋势.结论就p53基因突变和p53蛋白表达而言,距离肿瘤边缘5cm可定为肿瘤的分子切缘.

  19. HCV NS5A abrogates p53 protein function by interfering with p53-DNA binding

    Institute of Scientific and Technical Information of China (English)

    Guo-Zhong Gong; Yong-Fang Jiang; Yan He; Li-Ying Lai; Ying-Hua Zhu; Xian-Shi Su

    2004-01-01

    AIM: To evaluate the inhibition effect of HCV NS5A on p53 transactivation on p21 promoter and explore its possible mechanism for influencing p53 function.METHODS: p53 function of transactivation on p21 promoter was studied with a luciferase reporter system in which the luciferase gene is driven by p21 promoter, and the p53-DNA binding ability was observed with the use of electrophoretic mobility-shift assay (EMSA). Lipofectin mediated p53 or HCV NS5A expression vectors were used to transfect hepatoma cell lines to observe whether HCV NS5A could abrogate the binding ability of p53 to its specific DNA sequence and p53 transactivation on p21 promoter.Western blot experiment was used for detection of HCV NS5A and p53 proteins expression.RESULTS: Relative luciferase activity driven by p21 promoter increased significantly in the presence of endogenous p53 protein. Compared to the control group, exogenous p53 protein also stimulated p21 promoter driven luciferase gene expression in a dose-dependent way. HCV NS5A protein gradually inhibited both endogenous and exogenous p53 transactivation on p21 promoter with increase of the dose of HCV NS5A expression plasmid. By the experiment of EMSA, we could find p53 binding to its specific DNA sequence and, when co-transfected with increased dose of HCV NS5A expression vector, the p53 binding affinity to its DNA gradually decreased and finally disappeared. Between the Huh 7 cells transfected with p53 expression vector alone or co-transfected with HCV NS5A expression vector, there was no difference in the p53 protein expression.CONCLUSION: HCV NS5A inhibits p53 transactivation on p21 promoter through abrogating p53 binding affinity to its specific DNA sequence. It does not affect p53 protein expression.

  20. Gene mutations and increased levels of p53 protein in human squamous cell carcinomas and their cell lines.

    OpenAIRE

    Burns, J E; Baird, M. C.; Clark, L. J.; Burns, P A; Edington, K.; Chapman, C; Mitchell, R; Robertson, G; Soutar, D; Parkinson, E. K.

    1993-01-01

    Using immunocytochemical and Western blotting techniques we have demonstrated the presence of abnormally high levels of p53 protein in 8/24 (33%) of human squamous cell carcinomas (SCC) and 9/18 (50%) of SCC cell lines. There was a correlation between the immunocytochemical results obtained with eight SCC samples and their corresponding cell lines. Direct sequencing of PCR-amplified, reverse transcribed, p53 mRNA confirmed the expression of point mutations in six of the positive cell lines an...

  1. Experimental research for specific down-regulated expression of p53 gene by individual antisense RNA in vitro%个体性反义RNA特异性封闭突变p53基因的实验研究

    Institute of Scientific and Technical Information of China (English)

    Yahong Wang; Shaofeng Xu; Yuanyuan Zhang; Bin Zhang; Yumei Feng; Ruifang Niu; Li Fu

    2007-01-01

    Objective: To investigate the specific blockage effect of individual antisense RNA on mutant p53 gene in vitro.Methods: The single strand antisense transcription system containing mt-p53 exon 8 sequence (pGEM3zf(+/-)p53exon8)was constructed. The ligation of antisense RNA with mt-p53 gene was confirmed by in situ hybridization; MDA-MB-231 human breast cancer cells were transfected with ASp53exon8'RNA eationic liposome-mediated. Expression of mt-p53 protein was examined by immunocytochemical staining and Western blot. Cell proliferation was evaluated by MTT assay; Cell cycle distribution was determined by flow cytometry (FCM); Apoptosis was observed by TUNEL. Results: In transfected MDA-MB-231cells, hybridization signals were observed in cytoplasm. ASp53exon8'RNA transfection induced inhibition of cell proliferation,G2/M phase arrest and increasing apoptotic rates. In addition, expression of p53 protein was down-regulated. Conclusion:pGEM3zf(+/-)p53exon8 was well constructed and ASp53exon8'RNA can block mt-p53 gene expression specifically and then inhibit MDA-MB-231 cell proliferation in vitro, which may serve as therapeutic means for human malignancy.

  2. Conserved regulation of p53 network dosage by microRNA-125b occurs through evolving miRNA-target gene pairs.

    Directory of Open Access Journals (Sweden)

    Minh T N Le

    2011-09-01

    Full Text Available MicroRNAs regulate networks of genes to orchestrate cellular functions. MiR-125b, the vertebrate homologue of the Caenorhabditis elegans microRNA lin-4, has been implicated in the regulation of neural and hematopoietic stem cell homeostasis, analogous to how lin-4 regulates stem cells in C. elegans. Depending on the cell context, miR-125b has been proposed to regulate both apoptosis and proliferation. Because the p53 network is a central regulator of both apoptosis and proliferation, the dual roles of miR-125b raise the question of what genes in the p53 network might be regulated by miR-125b. By using a gain- and loss-of-function screen for miR-125b targets in humans, mice, and zebrafish and by validating these targets with the luciferase assay and a novel miRNA pull-down assay, we demonstrate that miR-125b directly represses 20 novel targets in the p53 network. These targets include both apoptosis regulators like Bak1, Igfbp3, Itch, Puma, Prkra, Tp53inp1, Tp53, Zac1, and also cell-cycle regulators like cyclin C, Cdc25c, Cdkn2c, Edn1, Ppp1ca, Sel1l, in the p53 network. We found that, although each miRNA-target pair was seldom conserved, miR-125b regulation of the p53 pathway is conserved at the network level. Our results lead us to propose that miR-125b buffers and fine-tunes p53 network activity by regulating the dose of both proliferative and apoptotic regulators, with implications for tissue stem cell homeostasis and oncogenesis.

  3. 福建地区口腔癌患者p53基因72密码子多态性与口腔癌易感性的研究%Study on p53 Gene Condon 72 Polymorphisms and Susceptibility of Oral Cancer of Fuji an Oral Cancer Pati ents

    Institute of Scientific and Technical Information of China (English)

    何保昌; 陈法; 刘芳萍; 柳迪萌; 陈珍; 蔡琳

    2014-01-01

    目的:研究p53基因多态性与口腔癌的关联。方法对149例口腔癌病例和303例对照病例采集5 mL血液样本,提取基因组DNA ,采用PCR‐RFLP法检测p53基因的多态性,利用Stata12.1软件分析p53基因的多态性与口腔癌的关联,并进行基因‐环境交互作用分析。结果 p53基因Pro/Pro基因型携带者较Arg/Arg基因型携带者口腔癌的发病风险增加1.837倍(95% CI:1.016,3.325)。p53基因Pro/Pro基因型与饮酒有相乘交互作用(OR相乘:4.375,95% CI:1.646,11.627)。结论 p53基因Pro/Pro基因型可能是福建地区口腔癌的易感基因,Pro/Pro基因型与饮酒具有相乘交互作用。%Objective To discover the association between p53 gene polymorphism and oral cancer in Fujian area . Methods 5 mL blood sample of 149 oral cancer patients and 303 controls w ere collected and their DNAs were extracted . p53 gene polymorphism was detected by polymerase chain reaction‐re‐striction fragment length . The association between p53 gene polymorphism and oral cancer ,and the in‐teraction effects of p53 gene polymorphism and environmental factors were analyzed by using Stata12 .1 . ResuIts Compared with Arg/Arg genotype ,p53 gene with Pro/Pro genotype was associated with higher risk of oral cancer(OR:1 .837 ,95% CI:1 .016 ,3 .325) . A multiplicative interaction between p53 gene with Pro/Pro genotype and alcohol drinking was found for oral cancer (ORmultiplicative :4 .375 ,95% CI:1 .646 , 11 .627) . ConcIusions There is multiplication interaction between p53 gene with Pro/Pro genotype and alcohol drinking ,w hich may be related to susceptibility of oral cancer in Fujian area .

  4. Deregulated expression of A1, Bcl-2, Bcl-xL, and Mcl-1 antiapoptotic proteins and Bid, Bad, and Bax proapoptotic genes in polycythemia vera patients

    Directory of Open Access Journals (Sweden)

    Elainy Patricia Lino Gasparotto

    2011-12-01

    Full Text Available Apoptosis deregulation might have a role in the pathophysiology of polycythemia vera (PV. This study evaluated Bcl-2 molecule expression in CD34+ cells and leukocytes in 12 PV patients. Gene expression was investigated by real time PCR using SybrGreen Quantitect kit and protein expression was evaluated by western-blotting. JAK2 V617F mutation was detected according to Baxter et al (2005. CD34+ cells from PV patients presented higher levels of A1 and Mcl-1 expression (median: 22.6 and 5.2, respectively in comparison with controls (0.9 and 0.5, p=0.004 and p=0.020; while Bcl-2 and Bcl-xL expression decreased in PV patients (0.18 and 1.19 compared with controls (1.39 and 2.01, p=0.006 and p=0.020. CD34+ cells in PV patients showed an elevated Bid expression (14.4 in comparison with healthy subjects (1.0; p=0.002. Patients' leukocytes showed an A1 augmentation (7.41, p=0.001 and a reduced expression of Bax (0.19; p=0.040 and Bad (0.2; p=0.030. There was no correlation between JAK2 V617F allele burden and molecular expression. PV patients showed alterations in Bcl-2 members' expression, which may interfere with control of apoptotic machinery and contribute to disease pathogenesis.A desregulação da apoptose parece participar da fisiopatologia da policitemia vera (PV. Este estudo avaliou a expressão das moléculas da família Bcl-2 em células hematopoéticas CD34 + e leucócitos de 12 pacientes com PV. Foram realizados: a quantificação da expressão gênica por PCR em tempo real utilizando kit Sybrgreen Quantitect, avaliação da expressão de proteínas por western-blot e detecção da mutação JAK2 V617F segundo Baxter et al. (2005. Células CD34 + dos pacientes com PV apresentaram maior expressão de A1 e Mcl-1 (mediana: 22,6 e 5,2, respectivamente em comparação com controles (0,9 e 0,5, p = 0,004 e p = 0,020 e expressão de Bcl-2 e Bcl-xL diminuída nestes pacientes (0,18 e 1,19 em relação aos controles (1,39 e 2,01, p = 0,006 e p = 0

  5. ADENOVIRUS-MEDIATED P53 GENE TRANSFER INCREASES THE THERMOSENSITIVITY OF HUMAN GASTRIC CARCINOMA CELL LINES (IN VITRO AND IN VIVO)

    Institute of Scientific and Technical Information of China (English)

    张珊文; 肖绍文; 吕有勇

    2003-01-01

    Objective: To investigate the effect of adenovirus- mediated p53 (Adp53) transfer on thermosensitivity of human gastric carcinoma cell lines (BGC823). Methods: Two human gastric carcinoma cell lines with different p53 status, BGC823-wtp53 cell (abbreviate W) bearing the wilt-type p53 and BGC823-mutp53 cell (abbreviate M) bearing the mutant p53, were cultured with DMEM medium and were infected with Adp53 at a viral multiplicity of infection of 100 (1:100MOI) for 48h before heating. Cell cycle redistribution and apoptosis of two human gastric carcinoma cell lines in 24h at 37℃ after heat treatment at 42℃ for 2h or 43℃ for 0.5h were analyzed by flow cytometry. Relative tumor volume growth curves were used in a nude mouse tumor model of the two cell lines following hyperthermia at 43℃ for 0.5h after 48h intratumoral injection of 1(108 pfu of Adp53 to evaluate thermoenhancemet effect in vivo. Results: In vitro study showed that both W and M cells infected with Adp53 and treated with heating had strong arrest in G2 (after heating at 42℃ for 2h, 34.0% of original population for W cells and 25.3% of original population for M cells) and produced obvious apoptotic response. The apoptosis rate showed 230% increased (for W cells) and 110% increase (for M cells) compared with heating only control. In vivo study showed that the growth of tumor of both W cells and M cells was significantly delayed by hyperthemia combining with Adp53 as compared to tumors receiving either treatment alone. Conclusion: This study demonstrated that Adp53 transfer increased cellular apoptosis and thermo- sensitivity in vitro and tumor thermosensitivity in vivo independent of cellular intrinsic p53 status. These results support the combined used of p53 gene therapy with hyperthermia in clinical trials.

  6. 抑癌基因p53调控的微RNA-miR-34基因家族%Tumor suppressor gene p53 regulated microRNA-miR-34 gene family

    Institute of Scientific and Technical Information of China (English)

    陈雪; 李子坚; 李力力; 曹亚

    2008-01-01

    微RNA(microRNA,miRNA)是一种内源性非编码小RNA,在转录后水平调控基因表达,在肿瘤的发生发展过程中起重要作用.p53是重要的抑癌基因,在DNA损伤和癌基因等刺激下活化,诱导下游基因表达,使细胞周期阻滞、DNA修复井促进细胞衰老或凋亡.本文主要介绍近期发现的直接受p53调控的miR-34基因家族,及其在生长阻滞和细胞凋亡方面的研究进展,揭示了蛋白质与非编码RNA在重要的p53抑癌网络中的相互关系,为肿瘤的研究提供了新的思路.

  7. Use of the comet-FISH assay to compare DNA damage and repair in p53 and hTERT genes following ionizing radiation.

    Directory of Open Access Journals (Sweden)

    Declan J McKenna

    Full Text Available The alkaline single cell gel electrophoresis (comet assay can be combined with fluorescent in situ hybridisation (FISH methodology in order to investigate the localisation of specific gene domains within an individual cell. The number and position of the fluorescent signal(s provides information about the relative damage and subsequent repair that is occurring in the targeted gene domain(s. In this study, we have optimised the comet-FISH assay to detect and compare DNA damage and repair in the p53 and hTERT gene regions of bladder cancer cell-lines RT4 and RT112, normal fibroblasts and Cockayne Syndrome (CS fibroblasts following γ-radiation. Cells were exposed to 5Gy γ-radiation and repair followed for up to 60 minutes. At each repair time-point, the number and location of p53 and hTERT hybridisation spots was recorded in addition to standard comet measurements. In bladder cancer cell-lines and normal fibroblasts, the p53 gene region was found to be rapidly repaired relative to the hTERT gene region and the overall genome, a phenomenon that appeared to be independent of hTERT transcriptional activity. However, in the CS fibroblasts, which are defective in transcription coupled repair (TCR, this rapid repair of the p53 gene region was not observed when compared to both the hTERT gene region and the overall genome, proving the assay can detect variations in DNA repair in the same gene. In conclusion, we propose that the comet-FISH assay is a sensitive and rapid method for detecting differences in DNA damage and repair between different gene regions in individual cells in response to radiation. We suggest this increases its potential for measuring radiosensitivity in cells and may therefore have value in a clinical setting.

  8. Loss of Expression of Reprimo, a p53-induced Cell Cycle Arrest Gene, Correlates with Invasive Stage of Tumor Progression and p73 Expression in Gastric Cancer.

    Directory of Open Access Journals (Sweden)

    Kathleen Saavedra

    Full Text Available Reprimo (RPRM, a downstream effector of p53-induced cell cycle arrest at G2/M, has been proposed as a putative tumor suppressor gene (TSG and as a potential biomarker for non-invasive detection of gastric cancer (GC. The aim of this study was to evaluate the epigenetic silencing of RPRM gene by promoter methylation and its tumor suppressor function in GC cell lines. Furthermore, clinical significance of RPRM protein product and its association with p53/p73 tumor suppressor protein family was explored. Epigenetic silencing of RPRM gene by promoter methylation was evaluated in four GC cell lines. Protein expression of RPRM was evaluated in 20 tumor and non-tumor matched cases. The clinical significance of RPRM association with p53/p73 tumor suppressor protein family was assessed in 114 GC cases. Tumor suppressor function was examined through functional assays. RPRM gene expression was negatively correlated with promoter methylation (Spearman rank r = -1; p = 0.042. RPRM overexpression inhibited colony formation and anchorage-independent growth. In clinical samples, RPRM gene protein expression was detected in 75% (15/20 of non-tumor adjacent mucosa, but only in 25% (5/20 of gastric tumor tissues (p = 0.001. Clinicopathological correlations of loss of RPRM expression were significantly associated with invasive stage of GC (stage I to II-IV, p = 0.02 and a positive association between RPRM and p73 gene protein product expression was found (p<0.0001 and kappa value = 0.363. In conclusion, epigenetic silencing of RPRM gene by promoter methylation is associated with loss of RPRM expression. Functional assays suggest that RPRM behaves as a TSG. Loss of expression of RPRM gene protein product is associated with the invasive stage of GC. Positive association between RPRM and p73 expression suggest that other members of the p53 gene family may participate in the regulation of RPRM expression.

  9. Mutant p53: multiple mechanisms define biologic activity in cancer

    Directory of Open Access Journals (Sweden)

    Michael Paul Kim

    2015-11-01

    Full Text Available The functional importance of p53 as a tumor suppressor gene is evident through its pervasiveness in cancer biology. The p53 gene is the most commonly altered gene in human cancer; however, not all genetic alterations are biologically equivalent. The majority of p53 alterations involve missense mutations that result in the production of mutant p53 proteins. Such mutant p53 proteins lack normal p53 function and may acquire novel functions, often with deleterious effects. Here, we review characterized mechanisms of mutant p53 gain of function in multiple model systems. In addition, we review mutant p53 addiction as emerging evidence suggests that tumors may depend on sustained mutant p53 activity for continued growth. We also discuss the role of p53 in stromal elements and their contribution to tumor initiation and progression. Lastly, current genetic mouse models of mutant p53 are reviewed and their limitations discussed.

  10. Effects of Δ40p53, an isoform of p53 lacking the N-terminus, on transactivation capacity of the tumor suppressor protein p53

    International Nuclear Information System (INIS)

    The p53 protein is expressed as multiple isoforms that differ in their N- and C-terminus due to alternative splicing, promoter or codon initiation usage. Δ40p53 lacks the first 39 residues containing the main transcriptional activation domain, resulting from initiation of translation at AUG +40 in fully spliced p53 mRNA or in a specific variant mRNA retaining intron 2. Overexpression of Δ40p53 antagonizes wild-type p53 in vitro. However, animal models of Δ40p53 in mouse or Zebrafish have shown complex phenotypes suggestive of p53-dependent growth suppressive effects. We have co-transfected expression vectors for p53 and Δ40p53 in p53-null cell lines Saos-2 and H1299 to show that Δ40p53 forms mixed oligomers with p53 that bind to DNA and modulate the transcription of a generic p53-dependent reporter gene. In H1299 cells, co-expression of the two proteins induced a decrease in transcription with amplitude that depended upon the predicted composition of the hetero-tetramer. In Saos-2, a paradoxical effect was observed, with a small increase in activity for hetero-tetramers predicted to contain 1 or 2 monomers of Δ40p53 and a decrease at higher Δ40p53/p53 ratios. In this cell line, co-transfection of Δ40p53 prevented Hdm2-mediated degradation of p53. Δ40p53 modulates transcriptional activity by interfering with the binding of Hdm2 to hetero-tetramers containing both Δ40p53 and p53. These results provide a basis for growth suppressive effects in animal models co-expressing roughly similar levels of p53 and Δ40p53

  11. Transcriptional upregulation of restin by p53

    Institute of Scientific and Technical Information of China (English)

    WANG RuiHua; LU Fan; FU HaiYan; WU YouSheng; YANG GuoDong; ZHAO WenMing; Zhao ZhongLiang

    2007-01-01

    Restin, belonging to the melanoma-associated antigen superfamily, was firstly cloned from the differentiated HL-60 cells when induced by all-trans retinoic acid ( ATRA ) in our lab. Our previous results showed that restin might be correlated to cell cycle arrest. Due to the importance of p53 in the regulation of cell growth and the relationship between p53 and ATRA, we tried to test the relationship between p53 and restin. Firstly, transfection results showed that p53 was able to upregulate the expression of restin at the transcriptional level when p53 was transfected into eukaryotic cells. Secondly, the bioinformatics analysis revealed that the upstream sequence (about 2 kb) from the first ATG of the ORF of restin gene contained a p53 binding site. In order to confirm that p53 was involved in the transcriptional regulation of restin, we cloned the upstream sequence of restin and constructed the promoter luciferase reporter system. From the luciferase activity, we demonstrated that the promoter of restin gene could be induced by ATRA. Then, another two luciferase reporter plasmids driven by the reporter of restin with no (RP△p53-luc) or mutant (mRP-luc) p53 binding site were constructed to see the regulation of restin by p53. Results showed that the transcriptional upregulation of restin gene was not due to the putative p53 binding site on the upstream of restin gene. We proposed that p53 upregulated restin transcription through an indirect way rather than direct interaction with the cis-activating element of the restin promoter.

  12. Transcriptional upregulation of restin by p53

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Restin, belonging to the melanoma-associated antigen superfamily, was firstly cloned from the differentiated HL-60 cells when induced by all-trans retinoic acid ( ATRA ) in our lab. Our previous results showed that restin might be correlated to cell cycle arrest. Due to the importance of p53 in the regulation of cell growth and the relationship between p53 and ATRA, we tried to test the relationship between p53 and restin. Firstly, transfection results showed that p53 was able to upregulate the expression of restin at the transcriptional level when p53 was transfected into eukaryotic cells. Secondly, the bioinformatics analysis revealed that the upstream sequence (about 2 kb) from the first ATG of the ORF of restin gene contained a p53 binding site. In order to confirm that p53 was involved in the transcriptional regulation of restin, we cloned the upstream sequence of restin and constructed the promoter luciferase reporter system. From the luciferase activity, we demonstrated that the promoter of restin gene could be induced by ATRA. Then, another two luciferase reporter plasmids driven by the reporter of restin with no (RP?p53-luc) or mutant (mRP-luc) p53 binding site were constructed to see the regulation of restin by p53. Results showed that the transcriptional upregulation of restin gene was not due to the putative p53 binding site on the upstream of restin gene. We proposed that p53 upregulated restin transcription through an indirect way rather than direct interaction with the cis-activating element of the restin promoter.

  13. 表浅性膀胱癌术后复发和生存率与p53和K-ras基因突变的关系%Relationship of K-ras and p53 gene mutation and superficial bladder cancer postoperative recurrence and survival rate

    Institute of Scientific and Technical Information of China (English)

    杨森; 南存金; 木海琦; 王怡君; 陈映鹤

    2013-01-01

    目的 探讨p53和K-ras基因突变与表浅性膀胱癌术后复发和生存率的关系.方法 选取表浅性膀胱癌切除术的137例患者,并选取29例正常膀胱黏膜组织作为对照,分别提取组织的DNA,采用聚合酶链反应-单链构象多态性分析(PCR-SSCP)和直接测序法分别分析p53和K-ras基因突变,并探讨p53和K-ras突变与表浅性膀胱癌术后复发及生存率的关系.结果 p53突变主要集中于外显子7和8,K-ras集中于外显子1和2.正常膀胱黏膜组织中p53和K-ras基因单突变率分别为3.45%(1/29)和6.90% (2/29),p53和K-ras基因双突变率为0% (0/29).膀胱癌组织中p53和K-ras单突变的发生率分别为43.07% (59/137)和30.66% (42/137),p53和K-ras双突变的发生率为26.28%(36/137).膀胱癌组织中p53和K-ras突变的发生率明显高于正常膀胱黏膜的发生率,差异有统计学意义(P<0.05).p53和K-ras双突变的术后复发率(75.00%)明显高于p53和K-ras单突变术后复发率(30.51%和28.57%),差异有统计学意义(P<0.05).p53和K-ras双突变的3年生存率明显低于p53和K-ras单突变的3年生存率,差异有统计学意义(P<0.05).结论 p53和K-ras突变可能是导致膀胱癌术后复发和生存率较低的原因之一.%Objective To explore the relationship of K-ras and p53 gene mutation and superficial bladder cancer postoperative recurrence and survival rate.Methods 137 bladder cancer patients subject to surgery were selected from December 2007 to June 2012.Twenty-nine normal tissue samples were selected as controls.Total DNA was extracted form bladder cancer tissues and normal tissues.p53 and K-ras gene mutations were analyzed by PCR-SSCP and gene sequencing.The relationship between p53 and K-ras gene mutation and superficial bladder cancer postoperative recurrence and survival rate was analyzed.Results p53 gene mutation was found in exons 7 and 8,and K-ras gene mutation in exons 1 and 2.p53 and K-ras gene single mutation rate

  14. Molecular mechanisms of growth suppression by pharmacologically activated p53

    OpenAIRE

    Hedström, Elisabeth

    2009-01-01

    The tumor suppressor p53 is a transcription factor that is crucial for protecting cells from cancer development. The importance of p53 tumor suppression function is highlighted by the fact that the p53 pathway is inactivated in most, if not all cancers. Mutation of the p53 gene occurs in about 50% of all tumors, whereas in the tumors which retain wild-type p53, the function of p53 is abolished due to deregulation of the p53 pathway. Due to the potency of p53 in suppressing t...

  15. BET Inhibition Induces Apoptosis in Aggressive B-Cell Lymphoma via Epigenetic Regulation of BCL-2 Family Members.

    Science.gov (United States)

    Hogg, Simon J; Newbold, Andrea; Vervoort, Stephin J; Cluse, Leonie A; Martin, Benjamin P; Gregory, Gareth P; Lefebure, Marcus; Vidacs, Eva; Tothill, Richard W; Bradner, James E; Shortt, Jake; Johnstone, Ricky W

    2016-09-01

    Targeting BET bromodomain proteins using small molecules is an emerging anticancer strategy with clinical evaluation of at least six inhibitors now underway. Although MYC downregulation was initially proposed as a key mechanistic property of BET inhibitors, recent evidence suggests that additional antitumor activities are important. Using the Eμ-Myc model of B-cell lymphoma, we demonstrate that BET inhibition with JQ1 is a potent inducer of p53-independent apoptosis that occurs in the absence of effects on Myc gene expression. JQ1 skews the expression of proapoptotic (Bim) and antiapoptotic (BCL-2/BCL-xL) BCL-2 family members to directly engage the mitochondrial apoptotic pathway. Consistent with this, Bim knockout or Bcl-2 overexpression inhibited apoptosis induction by JQ1. We identified lymphomas that were either intrinsically resistant to JQ1-mediated death or acquired resistance following in vivo exposure. Strikingly, in both instances BCL-2 was strongly upregulated and was concomitant with activation of RAS pathways. Eμ-Myc lymphomas engineered to express activated Nras upregulated BCL-2 and acquired a JQ1 resistance phenotype. These studies provide important information on mechanisms of apoptosis induction and resistance to BET-inhibition, while providing further rationale for the translation of BET inhibitors in aggressive B-cell lymphomas. Mol Cancer Ther; 15(9); 2030-41. ©2016 AACR. PMID:27406984

  16. Detection of p53 and MGMT gene mutations in patients with acute leukemia%急性白血病患者p53和MGMT基因突变检测

    Institute of Scientific and Technical Information of China (English)

    陈玉清; 李晓雯; 齐华; 连建华; 郑红; 翟亚萍; 张茵; 游文凤; 刘运卿

    2002-01-01

    目的:研究p53和MGMT基因突变在急性白血病发病中的意义以及p53基因突变与MGMT基因突变的关系.方法:应用聚合酶链反应-单链构象多态性(PCR-SSCP)技术,对36例急性非淋巴细胞白血病(ANLL),26例急性淋巴细胞白血病(ALL)和23例健康对照组骨髓细胞的p53和MGMT基因突变进行了分析.结果:p53基因突变率在ANLL中为16.7%、ALL中为19.2%,MGMT基因突变率在ANLL中为1 3.9%、ALL中为1 5.4%;62例急性白血病中有4例为p53和MGMT 2个基因同时发生突变;正常对照组均未发生p53和MGMT基因突变.结论:p53和MGMT基因突变在急性白血病发生与发展中起到一定作用,急性白血病中p53基因突变和MGMT基因突变密切相关.

  17. A study of the expression of p53 in posttransfection cells with rAdp53 gene and inhibitory activity in vitro

    Institute of Scientific and Technical Information of China (English)

    Jianhua Wang; Zongzheng Ji; Xiaoqiang Wang

    2007-01-01

    Objective: To investigate the inhibitory effect and IC50 (50% inhibiting concentration) of the recombinant adenoviral p53 gene (rAdp53) in colorectal cancer cells in vitro and to guide clinical practice. Methods: We evaluated the efficiency (IC50)of the rAdp53 and six kinds of anti-cancer drugs(5-fluorouracil, tegafur, mitomycin c, cisplatin, oxaliplatin, paclitaxel) in human colorectal cancer cell line-174 through the cell culture and MTT chemosensitivity assay to make sure the anti-cancer capability of rAdp53.Expression of p53 protein in transfection cells of colorectal cancer line-174 with rAdp53 was evaluated by immunohistochemical staining. Results: The rAdp53 is a dose- and time-dependent anti-cancer drug, its IC5o is 5.73×1011 VP/ml, but its effect was not obvious when compared with other anti-cancer drugs. In control group, the immunohistochemistry stain was negative. However,rAd-p53 of five different concentrations were all positive in infected colorectal cancer cells with rAd-p53 and the earliest positive result would present 24 hours after infection. Conclusion: The rAdp53 has good anti-cancer efficacy is colorectal cancer cell line174 in vitro. But its anti-cancer efficacy was less than those of the classical chemical medicine mitomycin c, 5-fluorouracil and cisplatin etc., when it was used alone.

  18. Effect of Bcl-2 and Bax on survival of side population cells from hepatocellular carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To understand the role and significance of side population (SP) cells from hepatocellular carcinoma (HCC) in hepatocarcinogenesis, development, relapse and metastasis, we simulated the denutrition conditions that cancer cells experience in clinical therapy, observed the different anti-apoptosis ability of SP cells and non-SP cells under such conditions, and established the possible effects of P53, Bcl-2 and Bax on survival of SP cells.METHODS: We used flow cytometry to analyze and sort the SP and non-SP cells in established HCC lines MHCC97and hHCC. We evaluated cell proliferation by methyl thiazolyl tetrazolium (MTT) assay and investigated the expression of p53, bd-2 and bax genes during denutrition,by RT-PCR and immunofluorescence staining.RESULTS: The percentage of SP cells in the two established HCC lines was 0.25% and 0.5%, respectively.SP cells had greater anti-apoptosis and proliferation ability than non-SP cells. Expression of Bcl-2 and Bax in SP and non-SP cells differed during denutrition. The former was up-regulated in SP cells, and the latter was up-regulated in non-SP cells.CONCLUSION: It may be that different upstream molecules acted and led to different expression levels of Bcl-2 and Bax in these two cell lines. There was a direct relationship between up-regulation of Bcl-2 and down-regulation of Bax and higher anti-apoptosis ability in SP cells. It may be that the existence and activity of SP cells are partly responsible for some of the clinical phenomena which are seen in HCC, such as relapse or metastasis. Further research on SP cells may have potential applications in the field of anticancer therapy.

  19. DNA-mediated oxidation of p53.

    Science.gov (United States)

    Schaefer, Kathryn N; Barton, Jacqueline K

    2014-06-01

    Transcription factor p53 is the most commonly altered gene in human cancer. As a redox-active protein in direct contact with DNA, p53 can directly sense oxidative stress through DNA-mediated charge transport. Electron hole transport occurs over long distances through the π-stacked bases and leads to the oxidative dissociation of p53. The extent of protein dissociation depends upon the redox potential of the DNA in direct contact with each p53 monomer. The DNA sequence dependence of p53 oxidative dissociation was examined by electrophoretic mobility shift assays using oligonucleotides containing both synthetic and human p53 consensus sequences with an appended photooxidant, anthraquinone. Greater p53 dissociation is observed from sequences containing low-redox potential purine regions, particularly guanine triplets. Using denaturing polyacrylamide gel electrophoresis of irradiated anthraquinone-modified DNA, the DNA damage sites corresponding to sites of preferred electron hole localization were determined. The resulting DNA damage preferentially localizes to guanine doublets and triplets. Oxidative DNA damage is inhibited in the presence of p53, but only at sites in direct contact with p53. From these data, predictions about the sensitivity of human p53-binding sites to oxidative stress as well as possible biological implications have been made. On the basis of our data, the guanine pattern within the purine region of each p53-binding site determines the response of p53 to DNA oxidation, yielding for some sequences the oxidative dissociation of p53 from a distance and thereby providing another potential role for DNA charge transport chemistry within the cell. PMID:24853816

  20. Mutations in APC, K-ras, and p53 gene in colorectal cancer%结直肠癌APC、K-ras、p53基因突变检测

    Institute of Scientific and Technical Information of China (English)

    唐卫中; 高枫; 李卫; 唐宗江

    2006-01-01

    目的:探讨结直肠癌中APC、K-ras、p53基因突变模式.方法:应用酚/氯仿法提取48例结直肠癌组织及其相应正常黏膜组织的DNA,用聚合酶链反应(PCR)、单链构象多态性分析(SSCP)和DNA测序等方法检测APC基因第15外显子突变密集区(mutation cluster region,MCR)区段、K-ras和p53基因的突变.结果:APC、K-ras和p53基因的突变率分别为37.5%(18/48)、43.8%(21/48)和35.4%(17/48).48例结直肠癌组织中,有42例发生APC、K-ras或p53基因突变,突变率高达87.5%(42/48),其中仅有APC、K-ras或p53 1种基因发生突变的发生率分别为16.7%(8/48)、25.0%(12/48)和20.8%(10/48).单独1种基因发生突变的总发生率为62.5%(30/48).APC和p53,APC和K-ras或p53和K-ras 2种基因均有突变的发生率分别为6.3%(3/48)、10.4%(5/48)和4.2%(2/48).APC、K-ras和p53 3种基因均发生突变的发生率为4.2%(2/48).2种和3种基因均发生突变的总发生率为25%(12/48).结论:结直肠癌的发生、发展并不完全遵循由正常结直肠黏膜上皮细胞向腺瘤和侵袭性癌转化的过程中,及依次发生"APC→K-ras→p53→DCC"突变累积这一经典的结直肠癌发生发展模式,可能存在其他结直肠癌发病机制.

  1. Phosphorylation of Thr18 and Ser20 of p53 in Ad-p53 – induced apoptosis

    OpenAIRE

    Nakamizo, Akira; Amano, Toshiyuko; Zhang, Wei; Zhang, Xin-qiao; Ramdas, Latha; Liu, Ta-Jen; Bekele, B. Nebiyou; Shono, Tadahisa; Sasaki, Tomio; Benedict, William F.; Sawaya, Raymond; Lang, Frederick F.

    2008-01-01

    The p53 protein plays a critical role in inducing cell cycle arrest or apoptosis. Because p53 is inactivated in human gliomas, restoring p53 function is a major focus of glioma therapy. The most clinically tested strategy for replacing p53 has been adenoviral-mediated p53 gene therapy (Ad-p53). In addition to their therapeutic implications, investigations into Ad-p53 provide model systems for understanding p53’s ability to induce cell cycle arrest versus apoptosis, particularly because wild-t...

  2. An immunohistochemical analysis of sex-steroid receptors, tumor suppressor gene p53 and Ki-67 in the normal and neoplastic uterine cervix squamous epithelium

    Directory of Open Access Journals (Sweden)

    Nikolaou Marinos

    2014-01-01

    Full Text Available Introduction. Malignant transformation of sex-steroid dependent tissues is associated with the loss of expression of sex steroid receptors as well as of the tumor suppression gene p53. The aim of this study is to evaluate the expression of sex-steroid receptors, p53 and Ki-67 in specimens from pre-malignant and malignant cervical epithelial lesions throughout the menstrual cycle. Material and Methods. Immunohistochemical staining was performed on formalin fixed, paraffin embedded tissue sections of normal squamous cervical epithelium, cervical intraepithelial neoplasia and invasive squamous cervical carcinoma, specimens utilizing antibodies against estrogen receptors, progesterone receptors, p53 protein and Ki-67 antigen. Results. In the samples taken from the normal cervical tissue, basal cells were usually estrogen receptor-positive, progesterone receptornegative, p53-negative and Ki-67-negative throughout the menstrual cycle. In contrast, para-basal cells were estrogen receptorpositive and progesterone receptor-negative in the follicular phase, but estrogen receptor-negative and progesterone receptor -positive and Ki-67 positive in the luteal phase. In cervical precancerous and cancer tissue samples (cervical intraepithelial neoplasia and squamous cervical carcinoma, the expression of estrogen receptors decreased. 31.15% of cervical intraepithelial neoplasia and 11.5% of squamous cervical carcinoma were positive for estrogen receptors. However, the expression of progesterone receptors increased. 29.5% of cervical intraepithelial neoplasia and 49.2% of squamous cervical carcinoma were positive for progesterone receptors. Positive staining for p53 was observed in 15 (24.59% cases of cervical intraepithelial neoplasia and in 39 (64% of squamous cervical carcinoma. The expression Ki-67 index in squamous cervical carcinoma cases (47.60% was significantly higher than of cervical intraepithelial neoplasia cases (30.2% (p=0.041. Conclusion. The

  3. Biphasic Effects of Nitric Oxide Radicals on Radiation-Induced Lethality and Chromosome Aberrations in Human Lung Cancer Cells Carrying Different p53 Gene Status

    International Nuclear Information System (INIS)

    Purpose: The aim of this study was to clarify the effects of nitric oxide (NO) on radiation-induced cell killing and chromosome aberrations in two human lung cancer cell lines with a different p53 gene status. Methods and Materials: We used wild-type (wt) p53 and mutated (m) p53 cell lines that were derived from the human lung cancer H1299 cell line, which is p53 null. The wtp53 and mp53 cell lines were generated by transfection of the appropriate p53 constructs into the parental cells. Cells were pretreated with different concentrations of isosorbide dinitrate (ISDN) (an NO donor) and/or 2-(4-Carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO) (an NO scavenger) and then exposed to X-rays. Cell survival, apoptosis, and chromosome aberrations were scored by use of a colony-forming assay, Hoechst 33342 staining assay and TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP [deoxyuridine triphosphate] nick end labeling) assay, and chromosomal banding techniques, respectively. Results: In wtp53 cells the induction of radioresistance and the inhibition of apoptosis and chromosome aberrations were observed in the presence of ISDN at low 2- to 10-μmol/L concentrations before X-irradiation. The addition of c-PTIO and ISDN into the culture medium 6 h before irradiation almost completely suppressed these effects. However, at high concentrations of ISDN (100-500 μmol/L), clear evidence of radiosensitization, enhancement of apoptosis, and chromosome aberrations was detected. However, these phenomena were not observed in mp53 cells at either concentration range with ISDN. Conclusions: These results indicate that low and high concentrations of NO radicals can choreograph inverse radiosensitivity, apoptosis, and chromosome aberrations in human lung cancer cells and that NO radicals can affect the fate of wtp53 cells.

  4. Immune response to p53 is dependent upon p53/HSP70 complexes in breast cancers.

    OpenAIRE

    Davidoff, A.M.; Iglehart, J D; Marks, J R

    1992-01-01

    Overexpression of the p53 protein, resulting from gene mutations that increase protein stability, has been detected in greater than 25% of primary human breast cancers. In addition, approximately 10% of breast cancer patients have circulating antibodies to the p53 protein. In this study, the anti-p53 humoral response is correlated with the presence and type of mutant p53 protein expressed in the tumor. In a series of 60 breast cancer patients, 0 of 30 tumors with normal, low-level p53 express...

  5. p53和ATM基因缺失在慢性淋巴细胞白血病患者中的预后价值%Prognostic significance of p53 and ATM gene deletion in patients with chronic lymphocytic leukemia

    Institute of Scientific and Technical Information of China (English)

    徐卫; 李建勇; 李丽; 吴雨洁; 于慧; 沈秋丹; 仇红霞

    2008-01-01

    Objective To explore the prognostic significance of p53 and ATM gene deletion in patients with chronic lymphocytic leukemia(CLL).Methods Interphase fluorescence in situ hybridization (FISH)and probes of LSI p53 and LSI ATM were used to detect p53 and ATM gene deletion in 80 patients with CLL.p53 and ATM gene deletion and their association with some prognostic factors were analyzed.The Kaplan-Meier method was used to calculate survivals,and results were compared using the Log-rank test.Multivariate COX regression analysis was used to assess associations between survival and potential risk factots.Results Out of the 80 CLL patients,p53 gene deletion was found in 14(17.5%)cases,ATM gene deletion in 9(11.3%)cases,and both the two genes delelion in 3(3.8%)cases.There was no significant differences of p53 and ATM gene deletion rates in sex,age,Binet stages,peripheral lymphocyte count,and the levels of LDH,β2-Me,and ZAP-70.The p53 and ATM gene deletion rates were higher in the group of CD38 high expression than that in the group of low expression(P=0.025 and P=0.001).Among 41 patients who received fludarabine containing protocol.none of the nine cases with p53 and/or ATM gene deletion achieved complete response(CR).while 12 of 32(37.5%)cases without the gene deletion achieved CR.The survival time was shorter in patients with p53 gene deletion(P<0.01).There was no association between outcome and ATM gene deletion(P=0.556).On multivariate analysis by COX regression,p53 gene deletion and CD38 expression(P=0.014 and P=0.017,respectively)were found to be independent faetom in predicting survival.Conclusion CLL patients with p53 and/or ATM gene deletion had poor therapeutic effect,and hence poor prognosis.%目的 探讨p53和ATM基因缺失在慢性淋巴细胞白血病患者(CLL)中的预后价值.方法 采用间期荧光原位杂交(FISH)技术和p53、ATM基因的序列特异性DNA探针对80例CLL患者的染色体标本进行p53和ATM基因缺失的检测,分析p53

  6. Tumorigenic potential of pituitary tumor transforming gene (PTTG in vivo investigated using a transgenic mouse model, and effects of cross breeding with p53 (+/− transgenic mice

    Directory of Open Access Journals (Sweden)

    Fong Miranda Y

    2012-11-01

    Full Text Available Abstract Background Pituitary tumor-transforming gene (PTTG is an oncogene that is overexpressed in variety of tumors and exhibits characteristics of a transforming gene. Previous transgenic mouse models to access the tumorigenic potential in the pituitary and ovary have resulted in dysplasia without formation of visible tumors, possibly due to the insufficient expression of PTTG. PTTG expression level is critical for ovarian tumorigenesis in a xenograft model. Therefore, the tumorigenic function of PTTG in vivo remains unclear. We generated a transgenic mouse that overexpresses PTTG driven by the CMV promoter to determine whether PTTG functions as a transforming oncogene that is capable of initiating tumorigenesis. Methods Transgenic animals were generated by microinjection of PTTG transgene into the male pronucleus of FVB 0.5 day old embryos. Expression levels of PTTG in tissues of transgenic animals were analyzed using an immunohistochemical analysis. H&E staining and immunohistostaining were performed to examine the type of tumor in transgenic and PTTG transgenic/p53+/- animals. Results PTTG transgenic offspring (TgPTTG were monitored for tumor development at various ages. H&E analysis was performed to identify the presence of cancer and hyperplastic conditions verified with the proliferation marker PCNA and the microvessel marker CD31. Immunohistochemistry was performed to determine transgene expression, revealing localization to the epithelium of the fallopian tube, with more generalized expression in the liver, lung, kidney, and spleen. At eight months of age, 2 out of 15 TgPTTG developed ovarian cancer, 2 out of 15 developed benign tumors, 2 out of 15 developed cervical dysplasia, and 3 out of 15 developed adenomyosis of the uterus. At ten months of age, 2 out of 10 TgPTTG developed adenocarcinoma of the ovary, 1 out of 10 developed a papillary serous adenocarcinoma, and 2 out of 10 presented with atypia of ovarian epithelial cells

  7. Tumorigenic potential of pituitary tumor transforming gene (PTTG) in vivo investigated using a transgenic mouse model, and effects of cross breeding with p53 (+/−) transgenic mice

    International Nuclear Information System (INIS)

    Pituitary tumor-transforming gene (PTTG) is an oncogene that is overexpressed in variety of tumors and exhibits characteristics of a transforming gene. Previous transgenic mouse models to access the tumorigenic potential in the pituitary and ovary have resulted in dysplasia without formation of visible tumors, possibly due to the insufficient expression of PTTG. PTTG expression level is critical for ovarian tumorigenesis in a xenograft model. Therefore, the tumorigenic function of PTTG in vivo remains unclear. We generated a transgenic mouse that overexpresses PTTG driven by the CMV promoter to determine whether PTTG functions as a transforming oncogene that is capable of initiating tumorigenesis. Transgenic animals were generated by microinjection of PTTG transgene into the male pronucleus of FVB 0.5 day old embryos. Expression levels of PTTG in tissues of transgenic animals were analyzed using an immunohistochemical analysis. H&E staining and immunohistostaining were performed to examine the type of tumor in transgenic and PTTG transgenic/p53+/- animals. PTTG transgenic offspring (TgPTTG) were monitored for tumor development at various ages. H&E analysis was performed to identify the presence of cancer and hyperplastic conditions verified with the proliferation marker PCNA and the microvessel marker CD31. Immunohistochemistry was performed to determine transgene expression, revealing localization to the epithelium of the fallopian tube, with more generalized expression in the liver, lung, kidney, and spleen. At eight months of age, 2 out of 15 TgPTTG developed ovarian cancer, 2 out of 15 developed benign tumors, 2 out of 15 developed cervical dysplasia, and 3 out of 15 developed adenomyosis of the uterus. At ten months of age, 2 out of 10 TgPTTG developed adenocarcinoma of the ovary, 1 out of 10 developed a papillary serous adenocarcinoma, and 2 out of 10 presented with atypia of ovarian epithelial cells. Tumorigenesis is a multi-step process, often requiring

  8. Status quo of p53 in the treatment of tumors.

    Science.gov (United States)

    Guan, Yong-Song; He, Qing; Zou, Qing

    2016-10-01

    The p53 gene is pivotal for oncogenesis in a combination of mutations in oncogenes and antioncogenes. The ubiquitous loss of the p53 pathway in human cancers has generated considerable interest in developing p53-targeted cancer therapies, but current ideas and approaches targeting p53 are conflicting. Current researches focus on cancer-selective drugs with therapeutic strategies that both activate and inhibit p53. As p53 is ubiquitously lost in human cancers, the strategy of exogenous p53 addition is reasonable. However, p53 acts not equally in all cell types; thus, individualized p53 therapy is the direction of future research. To clarify the controversies on p53 for improvement of future antitumor studies, the review focuses on the available technological protocols, including their advantages and limitations in terms of future therapeutic use of p53 in the management of tumors.

  9. A naturally occurring 4-bp deletion in the intron 4 of p53 creates a spectrum of novel p53 isoforms with anti-apoptosis function

    OpenAIRE

    SHI, HUI; Tao, Ting; Huang, Delai; Ou, Zhao; Chen, Jun; Peng, Jinrong

    2014-01-01

    p53 functions as a tumor suppressor by transcriptionally regulating the expression of genes involved in controlling cell proliferation or apoptosis. p53 and its isoform Δ133p53/Δ113p53 form a negative regulation loop in that p53 activates the expression of Δ133p53/Δ113p53 while Δ133p53/Δ113p53 specifically antagonizes p53 apoptotic activity. This pathway is especially important to safeguard the process of embryogenesis because sudden activation of p53 by DNA damage signals or developmental st...

  10. Efficacy of Recombinant Adenoviral Human p53 Gene in Treatment of Malignant Pleural or Peritoneal Effusions%Efficacy of Recombinant Adenoviral Human p53Gene in Treatment of Malignant Pleural or Peritoneal Effusions

    Institute of Scientific and Technical Information of China (English)

    Xin ZHANG; Yi HU; Jinliang WANG; Sujie ZHANG; Haitao TAO; Sun JING; Baishou WU

    2013-01-01

    Background and objective Once the malignant pleural or peritoneal effusion is developed it is difficult to control.This report presents a new method for controlling the malignant effusions.Methods Forty-eight patients,29 males and 19 females with an average age of 61.2 years old,who were satisfied with the study inclusion criteria,were recruited in this study.Twenty-seven and 21 patients had a malignant pleural and peritoneal effusion,respectively.After draining most of fluids,these patients received intra-cavity infusion of rAd-p53 once per week for 4 weeks,at dose of 2×1012 viral particles (VP) diluted into 200 mL of saline solution for pleural effusions,and 4×1012 VP diluted into 500 mL of saline solution for peritoneal effusions.Results Participants were followed up for a median time of 13.6 month.A total of 11 cases,7 with pleural effusions and 4 with peritoneal effusions achieved a complete response (CR),and 20 cases (12 pleural effusions and 8 peritoneal effusions) had a partial response (PR).The overall response rate is 64.6%.Patients' quality of life,assessed by using Karnofsky performance scale (KPS) scores,was improved by an average of 26.4.The one-year of overall survival rate was 54.2% with a median survival time of 12.5 months.There were no serious side effects observed except for self-limited fever found in 79.8% of the cases.Conclusions Intra-cavity infusion of rAd-p53 is an effective and safe treatment for the patients with malignant pleural or peritoneal effusions,especially for those patients who can't tolerate the standard treatments.

  11. Soft-shell clam (Mya arenaria) p53: A structural and functional comparison to human p53

    OpenAIRE

    Holbrook, Lauren A.C.; Butler, Rondi A.; Cashon, Robert E.; Van Beneden, Rebecca J.

    2008-01-01

    The tumor suppressor p53 regulates genes involved in progression through the cell cycle, DNA repair, senescence or apoptosis in response to cell stress. Dysregulation of p53 can result in uncontrolled cellular proliferation. Invertebrate homologues to human p53 (Hsp53) have been identified, including a putative p53 gene (Map53) from the soft-shell clam (Mya arenaria). Predicted sequences for human and clam p53 proteins exhibit conservation in key domains. In light of this similarity, and the ...

  12. 散发性结直肠癌APC、K-ras、p53、MMR基因突变检测%Mutations in APC,K-ras, p53 and MMR gene in colorectal cancer

    Institute of Scientific and Technical Information of China (English)

    徐艳松; 唐卫中; 高枫; 龙陈艳

    2009-01-01

    目的 探讨结直肠癌中APC、K-ras、p53、MMR基因突变模式.方法 应用酚/氯仿法提取48例结直肠癌组织及其相应正常黏膜组织的DNA,用聚合酶链反应(PCR)、单链构象多态性分析(SSCP)和DNA测序等方法检测APC基因第l5外显子突变密集区(mutation cluster region,MCR)区段、K-ras 、p53和MMR基因的突变.结果 hMLH1未发生突变, APC、K-ras、p53基因和hMSH2的突变率分别为37.5 %(18/48)、43.8 %(21/48)、35.4% (17/48)和4.2%(2/48).APC、K-ras、p53或hMSH2基因突变率高达91.7% (44/48).APC、K-ras,p53基因均发生突变的发生率为4.2%(2/48).结论 结直肠癌的发生、发展并不完全遵循由正常结直肠黏膜上皮细胞向腺瘤和侵袭性癌转化的过程,可能存在其他结直肠癌发病机制.

  13. The point mutation of ras and p53 genes in laryngeal squam ous cell carcinomas%用PC R-SSCP方法探讨ras基因、p53基因突变与喉癌的关系

    Institute of Scientific and Technical Information of China (English)

    辛露; 赵书佑; 罗兵

    2000-01-01

    目的:研究ras基因、p53基因突变与喉鳞状细胞癌发病的关系.方法:应用多聚酶链反应-单链构像多态性分析(PCR-SSCP)方法分析40例喉鳞状细胞癌H-ras,K-ras,和N-ras基因的第12密码子,p53 基因第5,7外显子中点突变的情况.结果:H-ras基因突变9例,突变率为22 .5%(9/40);K-ras基因突变8例,突变率为20%(8/40),N-ras基因突变5例,突变率为12.5% (5/40).p53基因第5外显子突变7例,突变率为17.5%(7/40);第7外显子突变9例,突变率为22 .5%(9/40).5例发现有两种基因突变,且均表现为ras基因和p53外显子改变.结论 :ras基因,p53基因的改变在喉鳞状细胞癌的发生中共同起作用.

  14. Discovery of gene expression-based pharmacodynamic biomarker for a p53 context-specific anti-tumor drug Wee1 inhibitor

    Directory of Open Access Journals (Sweden)

    Mizuarai Shinji

    2009-06-01

    Full Text Available Abstract Background Wee1 is a tyrosine kinase regulating S-G2 cell cycle transition through the inactivating phosphorylation of CDC2. The inhibition of Wee1 kinase by a selective small molecule inhibitor significantly enhances the anti-tumor efficacy of DNA damaging agents, specifically in p53 negative tumors by abrogating S-G2 checkpoints, while normal cells with wild-type p53 are not severely damaged due to the intact function of the G1 checkpoint mediated by p53. Since the measurement of mRNA expression requires a very small amount of biopsy tissue and is highly quantitative, the development of a pharmacodynamic (PD biomarker leveraging mRNA expression is eagerly anticipated in order to estimate target engagement of anti-cancer agents. Results In order to find the Wee1 inhibition signature, mRNA expression profiling was first performed in both p53 positive and negative cancer cell lines treated with gemcitabine and a Wee1 inhibitor, MK-1775. We next carried out mRNA expression profiling of skin samples derived from xenograft models treated with the Wee1 inhibitor to identify a Wee1 inhibitor-regulatory gene set. Then, the genes that were commonly modulated in both cancer cell lines and rat skin samples were extracted as a Wee1 inhibition signature that could potentially be used as a PD biomarker independent of p53 status. The expression of the Wee1 inhibition signature was found to be regulated in a dose-dependent manner by the Wee1 inhibitor, and was significantly correlated with the inhibition level of a direct substrate, phosphorylated-CDC2. Individual genes in this Wee1 inhibition signature are known to regulate S-G2 cell cycle progression or checkpoints, which is consistent with the mode-of-action of the Wee1 inhibitor. Conclusion We report here the identification of an mRNA gene signature that was specifically changed by gemcitabine and Wee1 inhibitor combination treatment by molecular profiling. Given the common regulation of

  15. The p53 target gene desmocollin 3 acts as a novel tumor suppressor through inhibiting EGFR/ERK pathway in human lung cancer.

    Science.gov (United States)

    Cui, Tiantian; Chen, Yuan; Yang, Linlin; Knösel, Thomas; Huber, Otmar; Pacyna-Gengelbach, Manuela; Petersen, Iver

    2012-12-01

    Desmosomes are intercellular junctions that confer strong cell-cell adhesion. Altered expression of desmocollin 3 (DSC3), a member of the desmosomal cadherin family, was found in various cancers; however, its functional involvement in carcinogenesis has not yet been elucidated. Expression/localization of DSC3 was analyzed by real-time reverse transcription-PCR, western blotting, immunofluorescence and immunohistochemistry. Methylation status of DSC3 was examined by demethylation tests, methylation-specific PCR and bisulfite sequencing. It turned out that downregulation of DSC3 in lung cancer cells was associated with DNA hypermethylation. In primary lung tumors, DSC3 was a potential diagnostic marker for lung squamous cell carcinoma, and DSC3 DNA hypermethylation was correlated with poor clinical outcome. To investigate the effect of the tumor suppressor gene p53 on DSC3, transient transfection with a wild-type p53-expression vector was performed. Overexpression of p53 resulted in an increased expression of DSC3 in a DSC3-unmethylated lung cancer cell line H2170, but not in H1299, a DSC3-methylated cell line. However, combination of p53 transfection with demethylation agent 5-aza-2'-deoxycytidine treatment led to increased expression of DSC3 in H1299 cells. Furthermore, functional studies after stable transfection of a DSC3 expression vector showed that ectopic expression of DSC3 inhibited cell proliferation, anchorage-independent growth, migration, as well as invasion, and most interestingly led to reduced phosphorylation levels of extracellular signal-regulated kinase1/2. Taken together, our data suggested that DSC3 acts as a novel tumor suppressor gene through inhibition of epidermal growth factor receptor/extracellular signal-regulated kinase signaling in lung cancer cells. PMID:22941060

  16. HPV E6,p53与宫颈癌的关系及其在基因治疗中的应用%The Relations between HPV E6,p53 and Cervical Cancer and its Application in Gene Therapy

    Institute of Scientific and Technical Information of China (English)

    赵彩凤

    2011-01-01

    目前宫颈癌的发病率仍居全世界妇女常见恶性肿瘤的第二位.高危型人乳头瘤病毒(high-risk Human Papillomavirus,HR-HPV)感染是宫颈癌及其癌前病变最主要的诱因之一.抑癌基因p53能够有效地抑制细胞增殖和促进细胞凋亡,人类近半数的肿瘤都与p53基因的突变和失活有关,HPV E6蛋白降解p53蛋白,是宫颈癌发生的前提.选择性杀伤p53功能缺失的肿瘤细胞,同时保护正常细胞,发展HPV疫苗及联合用药是临床肿瘤免疫学家进行宫颈癌基因治疗的目标.%Cervical cancer is still the second most common malignancy in women worldwide. The high - risk HPV( human papilloma virus )has been found to be the main cause of the majority of cervical cancers and its precursor lesions. P53 tumor suppressor gene can inhibit cell proliferation and promote apoptosis effectively. Nearly half of human tumors are associated with mutation and inactivation of p53 gene p53 protein degradation by HPV E6 protein is a precondition for cervical cancers. To selectively kill the p53 function - losing tumor cells while protecting the normal cells and to develop HPV vaccines,and the combination using of medicines are the cervical cancer gene therapy goals for clinical immunologist.

  17. P53 mutations in Ewing's sarcoma.

    Science.gov (United States)

    Park, Y K; Chi, S G; Kim, Y W; Park, H R; Unni, K K

    2001-01-01

    The p53 tumor suppressor gene is one of the most frequently altered genes in human malignancies. To explore the implication of p53 alteration in Ewing's sarcoma, we analyzed the deletion and sequence alterations of p53 and abnormal amplification of MDM2, which acts as a functional inhibitor of p53, in 35 tissue specimens. Quantitative genomic PCR analysis showed that 2 of 35 tumors have extremely low levels of the p53 gene, indicating a homozygous deletion of the gene. Mutational analysis of exons 4 to 9 of p53 by PCR-SSCP revealed that 3 of 35 tumors carry sequence alterations in exons 5 or 8, and DNA sequencing analysis identified missense point mutations at codon 132 (AAG-->ATG, lysine-->methionine) and codon 135 (TGC-->TCC, cystein-->serine) in exon 5, and codon 287 (GAG-->GTG, glutamic acid-->valine) in exon 8 from these tumors. No abnormal amplification of the MDM2 gene was recognized. Taken together, our data demonstrate that p53 is genetically altered in a small fraction of Ewing's sarcoma.

  18. p53-Dependent transcriptional responses to interleukin-3 signaling.

    Directory of Open Access Journals (Sweden)

    Anissa M Jabbour

    Full Text Available p53 is critical in the normal response to a variety of cellular stresses including DNA damage and loss of p53 function is a common feature of many cancers. In hematological malignancies, p53 deletion is less common than in solid malignancies but is associated with poor prognosis and resistance to chemotherapy. Compared to their wild-type (WT counterparts, hematopoietic progenitor cells lacking p53 have a greater propensity to survive cytokine loss, in part, due to the failure to transcribe Puma, a proapoptotic Bcl-2 family member. Using expression arrays, we have further characterized the differences that distinguish p53(-/- cells from WT myeloid cells in the presence of Interleukin-3 (IL-3 to determine if such differences contribute to the increased clonogenicity and survival responses observed in p53(-/- cells. We show that p53(-/- cells have a deregulated intracellular signaling environment and display a more rapid and sustained response to IL-3. This was accompanied by an increase in active ERK1/2 and a dependence on an intact MAP kinase signaling pathway. Contrastingly, we find that p53(-/- cells are independent on AKT for their survival. Thus, loss of p53 in myeloid cells results in an altered transcriptional and kinase signaling environment that favors enhanced cytokine signaling.

  19. Role of p53 in Cell Death and Human Cancers

    OpenAIRE

    Toshinori Ozaki; Akira Nakagawara

    2011-01-01

    p53 is a nuclear transcription factor with a pro-apoptotic function. Since over 50% of human cancers carry loss of function mutations in p53 gene, p53 has been considered to be one of the classical type tumor suppressors. Mutant p53 acts as the dominant-negative inhibitor toward wild-type p53. Indeed, mutant p53 has an oncogenic potential. In some cases, malignant cancer cells bearing p53 mutations display a chemo-resistant phenotype. In response to a variety of cellular stresses such as DNA ...

  20. The p53 target Wig-1 regulates p53 mRNA stability through an AU-rich element

    DEFF Research Database (Denmark)

    Vilborg, Anna; Glahder, Jacob-Andreas Harald; Wilhelm, Margareta T;

    2009-01-01

    The p53 target gene Wig-1 encodes a double-stranded-RNA-binding zinc finger protein. We show here that Wig-1 binds to p53 mRNA and stabilizes it through an AU-rich element (ARE) in the 3' UTR of the p53 mRNA. This effect is mirrored by enhanced p53 protein levels in both unstressed cells and cells...... exposed to p53-activating stress agents. Thus, the p53 target Wig-1 is a previously undescribed ARE-regulating protein that acts as a positive feedback regulator of p53, with implications both for the steady-state levels of p53 and for the p53 stress response. Our data reveal a previously undescribed link...... between the tumor suppressor p53 and posttranscriptional gene regulation via AREs in mRNA....

  1. Loss of oocytes due to conditional ablation of Murine double minute 2 (Mdm2) gene is p53-dependent and results in female sterility.

    Science.gov (United States)

    Livera, Gabriel; Uzbekov, Rustem; Jarrier, Peggy; Fouchécourt, Sophie; Duquenne, Clotilde; Parent, Anne-Simone; Marine, Jean-Christophe; Monget, Philippe

    2016-08-01

    Murine double minute 2 and 4 (Mdm2, Mdm4) are major p53-negative regulators, preventing thus uncontrolled apoptosis induction in numerous cell types, although their function in the female germ line has received little attention. In the present work, we have generated mice with specific invalidation of Mdm2 and Mdm4 genes in the mouse oocyte (Mdm2(Ocko) and Mdm4(Ocko) mice), to test their implication in survival of these germ cells. Most of the Mdm2(Ocko) but not Mdm4(Ocko) mice were sterile, with a dramatic reduction of the weight of ovaries and genital tract, a strong increase in follicle-stimulating hormone and luteinizing hormone serum levels, and a reduction of anti-mullerian hormone serum levels. Histological analyses revealed an obvious decrease of the number of growing follicles beyond the primary stage in Mdm2(Ocko) ovaries in comparison to controls, with a pronounced increase in the apparition of primary atretic follicles, most being devoid of oocyte. Similar phenotypes were observed with Mdm2(Ocko) Mdm4(Ocko) ovaries, with no worsening of the phenotype. However, we failed to detect any increase in p53 level in mutant oocytes, nor any other apoptotic marker, introgression of this targeted invalidation in p53-/- mice restored the fertility of females. This study is the first to show that Mdm2, but not Mdm4, has a critical role in oocyte survival and would be involved in premature ovarian insufficiency phenotype. PMID:27364741

  2. Genomic alterations in BCL2L1 and DLC1 contribute to drug sensitivity in gastric cancer.

    Science.gov (United States)

    Park, Hansoo; Cho, Sung-Yup; Kim, Hyerim; Na, Deukchae; Han, Jee Yun; Chae, Jeesoo; Park, Changho; Park, Ok-Kyoung; Min, Seoyeon; Kang, Jinjoo; Choi, Boram; Min, Jimin; Kwon, Jee Young; Suh, Yun-Suhk; Kong, Seong-Ho; Lee, Hyuk-Joon; Liu, Edison T; Kim, Jong-Il; Kim, Sunghoon; Yang, Han-Kwang; Lee, Charles

    2015-10-01

    Gastric cancer (GC) is the third leading cause of cancer-related deaths worldwide. Recent high-throughput analyses of genomic alterations revealed several driver genes and altered pathways in GC. However, therapeutic applications from genomic data are limited, largely as a result of the lack of druggable molecular targets and preclinical models for drug selection. To identify new therapeutic targets for GC, we performed array comparative genomic hybridization (aCGH) of DNA from 103 patients with GC for copy number alteration (CNA) analysis, and whole-exome sequencing from 55 GCs from the same patients for mutation profiling. Pathway analysis showed recurrent alterations in the Wnt signaling [APC, CTNNB1, and DLC1 (deleted in liver cancer 1)], ErbB signaling (ERBB2, PIK3CA, and KRAS), and p53 signaling/apoptosis [TP53 and BCL2L1 (BCL2-like 1)] pathways. In 18.4% of GC cases (19/103), amplification of the antiapoptotic gene BCL2L1 was observed, and subsequently a BCL2L1 inhibitor was shown to markedly decrease cell viability in BCL2L1-amplified cell lines and in similarly altered patient-derived GC xenografts, especially when combined with other chemotherapeutic agents. In 10.9% of cases (6/55), mutations in DLC1 were found and were also shown to confer a growth advantage for these cells via activation of Rho-ROCK signaling, rendering these cells more susceptible to a ROCK inhibitor. Taken together, our study implicates BCL2L1 and DLC1 as potential druggable targets for specific subsets of GC cases. PMID:26401016

  3. Drosophila larvae lacking the bcl-2 gene, buffy, are sensitive to nutrient stress, maintain increased basal target of rapamycin (Tor signaling and exhibit characteristics of altered basal energy metabolism

    Directory of Open Access Journals (Sweden)

    Monserrate Jessica P

    2012-07-01

    Full Text Available Abstract Background B cell lymphoma 2 (Bcl-2 proteins are the central regulators of apoptosis. The two bcl-2 genes in Drosophila modulate the response to stress-induced cell death, but not developmental cell death. Because null mutants are viable, Drosophila provides an optimum model system to investigate alternate functions of Bcl-2 proteins. In this report, we explore the role of one bcl-2 gene in nutrient stress responses. Results We report that starvation of Drosophila larvae lacking the bcl-2 gene, buffy, decreases survival rate by more than twofold relative to wild-type larvae. The buffy null mutant reacted to starvation with the expected responses such as inhibition of target of rapamycin (Tor signaling, autophagy initiation and mobilization of stored lipids. However, the autophagic response to starvation initiated faster in larvae lacking buffy and was inhibited by ectopic buffy. We demonstrate that unusually high basal Tor signaling, indicated by more phosphorylated S6K, was detected in the buffy mutant and that removal of a genomic copy of S6K, but not inactivation of Tor by rapamycin, reverted the precocious autophagy phenotype. Instead, Tor inactivation also required loss of a positive nutrient signal to trigger autophagy and loss of both was sufficient to activate autophagy in the buffy mutant even in the presence of enforced phosphoinositide 3-kinase (PI3K signaling. Prior to starvation, the fed buffy mutant stored less lipid and glycogen, had high lactate levels and maintained a reduced pool of cellular ATP. These observations, together with the inability of buffy mutant larvae to adapt to nutrient restriction, indicate altered energy metabolism in the absence of buffy. Conclusions All animals in their natural habitats are faced with periods of reduced nutrient availability. This study demonstrates that buffy is required for adaptation to both starvation and nutrient restriction. Thus, Buffy is a Bcl-2 protein that plays an

  4. APC、P53基因突变与内镜下早期大肠癌分型的关系%APC and P53 gene mutations in the early stage of colorectal carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    张斌; 吴晓冬; 李长锋; 杨蕾; 李丹丹; 张德恒

    2005-01-01

    目的探讨内镜下早期大肠癌的分型与APC、P53基因突变的关系.方法应用PCR-SSCP方法对本院内镜下及病理诊断的54例早期大肠癌患者的APC及P53基因突变进行检测,并对内镜下的不同形态大肠早期癌分组进行比较.结果隆起型(Ⅰ型)和表面隆起型(Ⅱa型)组与表面平坦型(Ⅱb型)、表面凹陷型(Ⅱc型)、还有混合型(Ⅱa+Ⅱc和Ⅱc+Ⅱa型)组进行比较,APC基因的突变率明显增高,存在显著差异(P<0.05),而P53基因的突变率在两组间没有显著差异.结论我们推测平坦及凹陷型的表浅型早期大肠癌与隆起型有不同的基因突变途径.

  5. 新型超支状液晶核酸传感器用于p53突变基因的检测%Novel Nucleic Acid Signal Amplification Liquid Crystal Biosensor for Detection of p53 Gene Mutation

    Institute of Scientific and Technical Information of China (English)

    范玉霞; 谭慧; 留玲微; 吴朝阳; 沈国励; 俞汝勤

    2013-01-01

    基于核酸杂交链式反应影响液晶取向的原理,构建了一种新型的超支状液晶核酸传感器用于检测p53突变基因.本文突破传统构建超支状分子的方式,采用杂交链式反应方法,以目标序列p53突变基因作为引发剂,3种不同的发卡探针Hairpin A,Hairpin B和Hairpin C为单体,在温和的条件下,通过改变单体的浓度和反应时间自发杂交组装形成尺寸和分子量可控的超支状DNA(branched-like DNA,bDNA).借助捕获探针将该超支状DNA连接到液晶传感基底表面,观察液晶分子取向改变前后的光学信号,实现了p53基因含249密码子突变序列的快速检测.本方法有望为核酸诊断的发展提供一种新的方法和思路.

  6. A spermine conjugated stearic acid-g-chitosan oligosaccharide polymer with different types of amino groups for efficient p53 gene therapy.

    Science.gov (United States)

    Meng, Tingting; Wu, Jie; Yi, Hanxi; Liu, Jingwen; Lu, Binbin; Yuan, Ming; Huang, Xuan; Yuan, Hong; Hu, Fuqiang

    2016-09-01

    The effect of various amino groups on gene vector is different. In order to combine their effect in one vector and finally promote the transfection efficiency, a biogenic tetra-amine spermine was introduced to modify the stearic acid-grafted chitosan oligosaccharide (CSOSA) polymer to build a new gene delivery system. The spermine linked CSOSA (SP-CSOSA) polymer consists two types of amino groups with 73.3%, 19.3% of all nitrogen atoms for primary and secondary amine groups, respectively. The SP modified CSOSA showed strong DNA condensation capability and obviously enhanced proton binding ability especially at about pH 5.0, which significantly promoted the escape of SP-CSOSA/pDNA complexes from endo-lysosoms. Moreover, the transfection efficiency at the N/P ratio of 10 could compete with that of Lipofectamine 2000 and PEI 25K, but with lower cytotoxicities. The therapeutic wild type p53 gene transfected by the SP-CSOSA polymer restored the function of aberrant p53 gene and induced obvious cell apoptosis and G1 phase arrest. We concluded that the new vector SP-CSOSA polymer proved to be a potential delivery system for gene therapy. PMID:27289311

  7. Overexpression of the hydatidiform mole-related gene F10 inhibits apoptosis in A549 cells through downregulation of BCL2-associated X protein and caspase-3.

    Science.gov (United States)

    Song, Yali; Zhang, Gong; Zhu, Xiulan; Pang, Zhanjun; Xing, Fuqi; Quan, Song

    2012-09-01

    The aim of this study was to investigate how the overexpression of the hydatidiform mole-related gene F10 affects apoptosis in human lung cancer A549 cells. A549 cells were transfected with pEGFP-N1-F10 (A549-F10) or pEGFP-N1 empty vector (A549-empty). Untransfected A549, A549-F10 or A549-empty cells were examined using the MTT cell proliferation assay and the TUNEL-FITC/Hoechst 33258 apoptosis assay. Western blotting was used to examine the expression levels of the pro-apoptotic genes, BCL2-associated X protein (BAX) and caspase-3. F10 was stably expressed in A549 cells. From 12 h, A549-F10 cells proliferated markedly faster than the untransfected and A549-empty cells. F10 overexpression also significantly inhibited apoptosis, as shown by the reduced number of TUNEL and Hoechst 33258 double-positive cells. This inhibition was likely due to an F10-induced reduction in the BAX and caspase-3 levels. The results of this study indicate that F10 overexpression inhibits apoptosis in A549 cells through the downregulation of the pro-apoptotic genes BAX and caspase-3. PMID:23741243

  8. Reversal of 5-flouroucial resistance by adenovirus-mediated transfer of wild-type p53 gene in multidrug-resiatant human colon carcinoma LoVo/5-FU cells

    Institute of Scientific and Technical Information of China (English)

    Zhi-Wei Yu; Peng Zhao; Ming Liu; Xin-Shu Dong; Ji Tao; Xue-Qin Yao; Xin-Hua Yin; Yu Li; Song-Bin Fu

    2004-01-01

    AIM: To observe the reversal effects of wide-type p53 gene on multi-drug resistance to 5-FU (LOVO/5-FU).METHODS: After treatment with Ad-p53, LOVO/5-FU sensitivity to 5-Fu was investigated using tetrazolium dye assay. Multidrug resistance gene-1 (MDR1) gene expression was assayed by semi-quantitative reverse transcriptionpolymerase chain reaction and the expression of p53 protein was examined by Western blotting.RESULTS: The reversal activity after treatment with widetype p53 gene was increased up to 4.982 fold at 48 h. The expression of MDR1 gene decreased significantly after treatment with wide-type p53 gene, and the expression of p53 protein lasted for about 5 d, with a peak at 48 h, and began to decrease at 72 h.CONCLUSION: Wide-type p53 gene has a remarkable reversal activity for the high expression of MDR1 gene in colorectal cancers. The reversal effects seem to be in a time dependent manner. It might have good prospects in clinical application.

  9. bax和p53基因共转染对人舌癌细胞增 殖和凋亡的影晌%Effect on Proliferation and Apoptosis of Human Lingual Carc inoma Cells Cotransfected by bax and p53 Genes

    Institute of Scientific and Technical Information of China (English)

    马英红; 杨绍华; 陈俊杰; 高家让; 彭文珍; 王若菡

    2001-01-01

    Objective To investigate th e effects on prolife ration andapoptosis of human cancerous cells cotransfected by bax apoptosis-in ducing gene and p53 tumor suppressor gene. Methods The chi meric gene pSV-CIP-bax -CAT was constructed in which bax gene was flanked upstream by a 217bp fragment (+822~+1093) of the first intron and a 317bp promoter fragment of human a 1(Ⅰ) colla gen gene . Human lingual carcinoma cell line Tca 8113 (LCC) in culture was respe ctively transfected with pSV-CIP-bax-CAT, and cotransfected with pSV-p53-CA T and pSV-CIP-bax-CAT by using the transfection reagent DOSPER. Res ults Immuno- slot blot and ELISA demonstrated that the expression of bax and p53 genes incr eased remarkably in the transfected and cotransfected LCC, compared with the con trols(LCC transfected with pSV-CIP-CAT and LCC).MTT colorimetric assay,TUNE L fluorecence microscopy and flow cytometry showed that foreign bax or p53 gene inhibited the LCC growth and induced apoptosis(23.9% and 26.1% of inhibitory ra te by bax gene and p53 plus bax genes respectively). Conclusion The ectopic expression of the bax gene in the LCC promoted by the cis-act ing elements of human a1(Ⅰ)collagen gene has obviously synergistic effect on th e proliferation and apoptosis of the LCC cotransfected with p53 gene plus bax gene for 48 hours.%目的 探讨诱导凋亡的bax基因和p53抑癌基因共转染对人癌细胞增殖和凋亡的作用。方法 构建pSV-CIP-bax-CAT嵌合基因。在其bax基因上游含人a1(Ⅰ)型胶原基因的第一内含子217bp片段(+822~+1093)和317bp启动子片段。经阳离子转染试剂DOSPER介导,分别用pSV-CIP-bax-CAT转染、pSV-CIP-bax-CAT和pSV-p53-CAT共转染培养的人舌癌Tca8113细胞系(LCC)。结果 免疫狭缝印迹和ELISA检测证实,转染组和共转染组比对照的bax和p53基因表达量明显增加。MTT显色分析、TUNEL荧光显微镜和流式细胞仪监测结果显示,bax基因或p53基因均具抑

  10. Validation of whole genome amplification for analysis of the p53 tumor suppressor gene in limited amounts of tumor samples.

    Science.gov (United States)

    Hasmats, Johanna; Green, Henrik; Solnestam, Beata Werne; Zajac, Pawel; Huss, Mikael; Orear, Cedric; Validire, Pierre; Bjursell, Magnus; Lundeberg, Joakim

    2012-08-24

    Personalized cancer treatment requires molecular characterization of individual tumor biopsies. These samples are frequently only available in limited quantities hampering genomic analysis. Several whole genome amplification (WGA) protocols have been developed with reported varying representation of genomic regions post amplification. In this study we investigate region dropout using a φ29 polymerase based WGA approach. DNA from 123 lung cancers specimens and corresponding normal tissue were used and evaluated by Sanger sequencing of the p53 exons 5-8. To enable comparative analysis of this scarce material, WGA samples were compared with unamplified material using a pooling strategy of the 123 samples. In addition, a more detailed analysis of exon 7 amplicons were performed followed by extensive cloning and Sanger sequencing. Interestingly, by comparing data from the pooled samples to the individually sequenced exon 7, we demonstrate that mutations are more easily recovered from WGA pools and this was also supported by simulations of different sequencing coverage. Overall this data indicate a limited random loss of genomic regions supporting the use of whole genome amplification for genomic analysis.

  11. The prognostic value of p53 and the mismatch repair genes MLH1 and MSH2 in colorectal cancer and their impact on adjuvant therapy

    OpenAIRE

    Müller, Kathrin

    2010-01-01

    The prognostic impact of p53, MLH1 and MSH2 expression in colorectal cancer is still under debate. Moreover, the p53 mutation status is seldom considered. This study investigated the expression of p53, MLH1 and MSH2 and the mutation of p53 in a cohort of 116 patients with UICC stage II/III sporadic colorectal cancer. Immunohistochemistry revealed that p53 was expressed in 63%, MLH1 in 91%, and MSH2 in 96% of the cases. The p53 mutation status was determined indirectly by analyzing the expres...

  12. Evaluation of biological activities of Physalis peruviana ethanol extracts and expression of Bcl-2 genes in HeLa cells

    OpenAIRE

    Özgür Çakir; Murat Pekmez; Elif Çepni; Bilgin Candar; Kerem Fidan

    2014-01-01

    Physalis species are used in folk medicine for phytotherapeutic properties. The extracts of medicinal plants are known to possess cytotoxic and chemopreventative compounds. In this study we investigated antibacterial, antioxidant, DNA damage preventative properties of Physalis peruviana (golden berry) on leaf and shoot ethanol extracts and their effects on cytotoxicity of HeLa cells and expression of apoptotic pathway genes. Among the tested bacteria for antibacterial activity, maximum inhibi...

  13. Molecular and Computational Studies on Apoptotic Pathway Regulator, Bcl-2 Gene from Breast Cancer Cell Line MCF-7.

    Science.gov (United States)

    Tiwari, Pragya; Khan, M J

    2016-01-01

    Cancer is a dreadful disease constituting abnormal growth and proliferation of malignant cells in the body. Next to lung cancer, breast cancer is the most common form of cancer affecting women. The apoptotic pathway regulators, B cell lymphoma family of protein, play a key role in various malignancies defining cancer and their constitutive expression plays an integral role in breast cancer chemotherapy. The research work discusses the identification and molecular cloning of a B cell lymphoma like gene from human breast cancer cell line. The open reading frame of the gene consisted of 965 nucleotides, encoding a protein of 380 amino acids with a predicted molecular weight of 42.5 kilodalton. The predicted physiochemical properties of the gene were as follows: Isoelectric point - 9.49, molecular formula - C1893H3004N534O548S16, total number of negatively charged residues, (Aspartate+Glutamate) - 26, total number of positively charged residues, (Arginine+Lysine)-39, instability index-42.08 (unstable protein) and grand average of hydropathicity is -0.202. Additionally, phobius prediction suggested non-cytoplasmic localization of the putative protein. The presence of secondary structure in the protein was determined by Memsat program. A 3 dimensional protein homology model was generated using threading based method of protein modeling for structural and functional annotation of the putative protein. Future prospects accounts for the biochemical characterization of the enzyme including in vitro assays on breast cancer cell line would establish the functional characteristics of the protein and its physiological mechanisms in breast cancer development and its therapeutic-target role in future. PMID:27168686

  14. Transcriptional inhibition of p21{sup WAF1/CIP1} gene (CDKN1) expression by survivin is at least partially p53-dependent: Evidence for survivin acting as a transcription factor or co-factor

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Lei [Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, NY (United States); Pre-Doctoral Chinese Fellowship Student, Second West China Hospital, Sichuan University, Sichuan (China); Ling, Xiang; Liu, Wensheng; Das, Gokul M. [Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, NY (United States); Li, Fengzhi, E-mail: fengzhi.li@roswellpark.org [Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, NY (United States)

    2012-05-04

    } expression at least in part by neutralizing p53-mediated transcriptional activation of the p21 gene.

  15. Evaluation of biological activities of Physalis peruviana ethanol extracts and expression of Bcl-2 genes in HeLa cells

    Directory of Open Access Journals (Sweden)

    Özgür Çakir

    2014-06-01

    Full Text Available Physalis species are used in folk medicine for phytotherapeutic properties. The extracts of medicinal plants are known to possess cytotoxic and chemopreventative compounds. In this study we investigated antibacterial, antioxidant, DNA damage preventative properties of Physalis peruviana (golden berry on leaf and shoot ethanol extracts and their effects on cytotoxicity of HeLa cells and expression of apoptotic pathway genes. Among the tested bacteria for antibacterial activity, maximum inhibition zone was determined in Lactococcus lactis. The phenolic content was found higher in leaf extracts than shoot extracts. The antioxidant activity showed the highest TEAC values of the leaf (2 mg/mL and the shoot (0.5 mg/mL extracts as 0.291±0.04 and 0.192±0.015, respectively. In DNA damage prevention assay both leaf and shoot extracts, especially 30 and 20 µg/mL concentrations, exhibited significant protection against DNA damage-induced by hydroxyl radical generated by Fenton reaction. Our results suggest that leaf and shoot extracts possess cytotoxic effect on HeLa cells when applied as 100 µg/mL concentration. Also mRNA expression analysis showed the alteration of antiapoptotic genes, so the results suggest that P. peruviana ethanol extracts induce apoptotic cell death and should be investigated for identification of active compounds and their mechanisms of action.

  16. Acidosis Promotes Bcl-2 Family-mediated Evasion of Apoptosis

    Science.gov (United States)

    Ryder, Christopher; McColl, Karen; Zhong, Fei; Distelhorst, Clark W.

    2012-01-01

    Acidosis arises in solid and lymphoid malignancies secondary to altered nutrient supply and utilization. Tumor acidosis correlates with therapeutic resistance, although the mechanism behind this effect is not fully understood. Here we show that incubation of lymphoma cell lines in acidic conditions (pH 6.5) blocks apoptosis induced by multiple cytotoxic metabolic stresses, including deprivation of glucose or glutamine and treatment with dexamethasone. We sought to examine the role of the Bcl-2 family of apoptosis regulators in this process. Interestingly, we found that acidic culture causes elevation of both Bcl-2 and Bcl-xL, while also attenuating glutamine starvation-induced elevation of p53-up-regulated modulator of apoptosis (PUMA) and Bim. We confirmed with knockdown studies that these shifts direct survival decisions during starvation and acidosis. Importantly, the promotion of a high anti- to pro-apoptotic Bcl-2 family member ratio by acidosis renders cells exquisitely sensitive to the Bcl-2/Bcl-xL antagonist ABT-737, suggesting that acidosis causes Bcl-2 family dependence. This dependence appears to be mediated, in part, by the acid-sensing G protein-coupled receptor, GPR65, via a MEK/ERK pathway. PMID:22685289

  17. Identification of the Bcl-2 family protein gene BOK from orange-spotted grouper (Epinephelus coioides) involved in SGIV infection.

    Science.gov (United States)

    Cai, Jia; Yu, Dapeng; Wei, Shina; Tang, Jufen; Lu, Yishan; Wu, Zaohe; Qin, Qiwei; Jian, Jichang

    2016-05-01

    Apoptosis plays vital roles in many physiological process and immune response. BOK is one of the central regulators in apoptosis. In this study, a new BOK homolog (Ec-BOK) was cloned and characterized from Orange-spotted grouper, Epinephelus coioides. Ec-BOK encoded a 210 amino acid peptides which shared 97% identity to Stegastes partitus BOK protein, contained four BH domains and one transmembrane region. Ec-BOK widely expressed in all analyzed tissues with the higher expressions in kidney and spleen. Its expression level was up-regulated after SGIV infection in vitro. Further analysis revealed that overexpression of Ec-BOK inhibited viral genes transcriptions and virus replication in fish cell. Our findings suggested that Ec-BOK might play a role in the immune response against virus.

  18. Enhanced apoptotic response to photodynamic therapy after bcl-2 transfection.

    Science.gov (United States)

    Kim, H R; Luo, Y; Li, G; Kessel, D

    1999-07-15

    Apoptosis is a cellular death process involving the sequential activation of a series of caspases, endonucleases, and other enzymes. The initiation of apoptosis can be inhibited by overexpression of bcl-2 and certain other members of a related family of proteins. We examined the effects of bcl-2 overexpression on the apoptotic response to photodynamic therapy (PDT), using aluminum phthalocyanine as the photosensitizing agent. In this study, we compared the immortalized human breast epithelial cell line MCF10A with a subline (MCF10A/bcl-2) transfected with the human bcl-2 gene. The latter was approximately 2-fold more sensitive to the phototoxic effects of PDT. At a 50 mJ/cm2 light dose, photodamage to MCF-10A/bcl-2 resulted in a greater loss of the mitochondrial membrane potential (delta(psi)m), enhanced release of mitochondrial cytochrome c, a more rapid and greater activation of caspase-3, and a greater apoptotic response. Western blot analysis revealed that the transfected cell line showed overexpression of both bcl-2 and bax, and that PDT caused selective destruction of bcl-2, leaving bax unaffected. The greater apoptotic response by the transfected line is, therefore, attributed to the higher bax:bcl-2 ratio after photodamage.

  19. Lycopene modulates cholinergic dysfunction, Bcl-2/Bax balance, and antioxidant enzymes gene transcripts in monosodium glutamate (E621) induced neurotoxicity in a rat model.

    Science.gov (United States)

    Sadek, Kadry; Abouzed, Tarek; Nasr, Sherif

    2016-04-01

    The effect of monosodium glutamate (MSG) on brain tissue and the relative ability of lycopene to avert these neurotoxic effects were investigated. Thirty-two male Wistar rats were distributed into 4 groups: group I, untreated (placebo); group II, injected with MSG (5 mg·kg(-1)) s.c.; group III, gastrogavaged with lycopene (10 mg·kg(-1)) p.o.; and group IV received MSG with lycopene with the same mentioned doses for 30 days. The results showed that MSG induced elevation in lipid peroxidation marker and perturbation in the antioxidant homeostasis and increased the levels of brain and serum cholinesterase (ChE), total creatine phosphokinase (CPK), creatine phosphokinase isoenzymes BB (CPK-BB), and lactate dehydrogenase (LDH). Glutathione S-transferase (GST), superoxide dismutase (SOD), and catalase (CAT) activities and gene expression were increased and glutathione content was reduced in the MSG-challenged rats, and these effects were ameliorated by lycopene. Furthermore, MSG induced apoptosis in brain tissues reflected in upregulation of pro-apoptotic Bax while lycopene upregulated the anti-apoptotic Bcl-2. Our results indicate that lycopene appears to be highly effective in relieving the toxic effects of MSG by inhibiting lipid peroxidation and inducing modifications in the activity of cholinesterase and antioxidant pathways. Interestingly, lycopene protects brain tissue by inhibiting apoptosis signaling induced by MSG. PMID:26900785

  20. THE ROLES OF bcl-2 GENE FAMILY IN THE PULMONARY ARTERY REMODELING OF HYPOXIA PULMONARY HYPERTENSION IN RATS

    Institute of Scientific and Technical Information of China (English)

    王巨; 王凯; 王柏春; 杨成; 王胜发; 梁桃

    2001-01-01

    Objective. To investigate the roles of apeptosis in the pulmonary artery remodeling of pulmonary hypertension secondary to hypoxia and illustrate the relative genes expression. Methods. Thirty rats were divided into hypoxia group(10%O2, 8h/d) and normal control group. On the 15th day of hypoxia, pulmonary artery pressure and fight ventricular hypertrophy index were measured and pulmonary artery vessels were studied by light microscope. Then terminal deoxynucleotidyl transferase-mediateddUTP nick-end labeling(TUNEL)technique was used to detect nucleosomal DNA fragmentation of apeptotic cells.In situ hybridization and RT-PCR were used to detect the expression level of bel-2 and bax. Results. The pulmonary artery pressure and right ventricular hypertrophy index of hypoxia group were increased significantly, the pulmonary artery wall of hypoxic group become incrassate than control group. Apeptotic cells can be found in lung with hypoxia or without hypexia. Compared with control group, apeptotic index of hypoxic group decreased significantly. Through the methods of in situ hybridization and RT-PCR, we found the expression of bel-2 increased whereas bax decreased significantly in the hypoxic group. Conclusion. The alternation in bel-2 and bax expression induced by hypoxia play an important role in the pulmonary artery remodeling which is the main pathologic change of p~monary hypertension secondary to hypoxia.

  1. BCL2 protein expression in follicular lymphomas with t(14;18) chromosomal translocations.

    Science.gov (United States)

    Masir, Noraidah; Campbell, Lisa J; Goff, Lindsey K; Jones, Margaret; Marafioti, Teresa; Cordell, Jacqueline; Clear, Andrew J; Lister, T Andrew; Mason, David Y; Lee, Abigail M

    2009-03-01

    The t(14;18)(q32;q21) chromosomal translocation induces BCL2 protein overexpression in most follicular lymphomas. However the expression of BCL2 is not always homogeneous and may demonstrate a variable degree of heterogeneity. This study analysed BCL2 protein expression pattern in 33 cases of t(14;18)-positive follicular lymphomas using antibodies against two different epitopes (i.e. the widely used antibody BCL2/124 and an alternative antibody E17). 16/33 (49%) cases demonstrated strong BCL2 expression. In 10/33 (30%) cases, BCL2 expression was heterogeneous and in some of these, its loss appeared to be correlated with cell proliferation, as indicated by Ki67 expression. Double immunofluorescence labelling confirmed an inverse BCL2/Ki67 relationship, where in 24/28 (86%) cases cellular expression of BCL2 and Ki67 was mutually exclusive. In addition, seven BCL2 'pseudo-negative' cases were identified in which immunostaining was negative with antibody BCL2/124, but positive with antibody E17. Genomic DNA sequencing of these 'pseudo-negative' cases demonstrated eleven mutations in four cases and nine of these were missense mutations. It can be concluded that in follicular lymphomas, despite carrying the t(14;18) translocations, BCL2 protein expression may be heterogeneous and loss of BCL2 could be related to cell proliferation. Secondly, mutations in translocated BCL2 genes appear to be common and may cause BCL2 pseudo-negative immunostaining. PMID:19120369

  2. Retention of wild-type p53 in tumors from p53 heterozygous mice: reduction of p53 dosage can promote cancer formation.

    OpenAIRE

    Venkatachalam, S; Shi, Y P; Jones, S N; Vogel, H.; Bradley, A.; Pinkel, D; Donehower, L A

    1998-01-01

    Tumor suppressor genes are generally viewed as being recessive at the cellular level, so that mutation or loss of both tumor suppressor alleles is a prerequisite for tumor formation. The tumor suppressor gene, p53, is mutated in approximately 50% of human sporadic cancers and in an inherited cancer predisposition (Li-Fraumeni syndrome). We have analyzed the status of the wild-type p53 allele in tumors taken from p53-deficient heterozygous (p53+/-) mice. These mice inherit a single null p53 al...

  3. Expression of Androgen Receptor Is Negatively Regulated By p53

    Directory of Open Access Journals (Sweden)

    Fatouma Alimirah

    2007-12-01

    Full Text Available Increased expression of androgen receptor (AR in prostate cancer (PC is associated with transition to androgen independence. Because the progression of PC to advanced stages is often associated with the loss of p53 function, we tested whether the p53 could regulate the expression of AR gene. Here we report that p53 negatively regulates the expression of AR in prostate epithelial cells (PrECs. We found that in LNCaP human prostate cancer cells that express the wild-type p53 and AR and in human normal PrECs, the activation of p53 by genotoxic stress or by inhibition of p53 nuclear export downregulated the expression of AR. Furthermore, forced expression of p53 in LNCaP cells decreased the expression of AR. Conversely, knockdown of p53 expression in LNCaP cells increased the AR expression. Consistent with the negative regulation of AR expression by p53, the p53-null HCT116 cells expressed higher levels of AR compared with the isogenic HCT116 cells that express the wildtype p53. Moreover, we noted that in etoposide treated LNCaP cells p53 bound to the promoter region of the AR gene, which contains a potential p53 DNA-binding consensus sequence, in chromatin immunoprecipitation assays. Together, our observations provide support for the idea that the loss of p53 function in prostate cancer cells contributes to increased expression of AR.

  4. Precocious anaphase and expression of Securin and p53 genes as candidate biomarkers for the early detection in areca nut-induced carcinogenesis.

    Science.gov (United States)

    Kurkalang, Sillarine; Banerjee, Atanu; Dkhar, Hughbert; Nongrum, Henry B; Ganguly, Buddha; Islam, Mohammad; Rangad, Gordon M; Chatterjee, Anupam

    2015-05-01

    Research over the years has generated enough evidence to implicate areca nut, as a carcinogen in humans. Besides oral, significant rise in the incidence of cancers of the oesophagus, liver and stomach was seen among areca nut chewers. Early diagnosis seems key to understand the initial processes of carcinogenesis which is highly curable. In North-East India, betel quid contains raw areca nut (RAN), lime and small portion of betel leaf without any other constituents. This study was not intended to isolate any active ingredients from the RAN and to look its action. The present objective is to validate the screening of precocious anaphase and analysis of expression of Securin and p53 in non-target cells like human peripheral blood lymphocytes (PBLs) and mouse bone marrow cells (BMCs) as early indicative parameters of RAN + lime-induced cancers. A total of 35 mice were examined at different time points for following ad libitum administration of RAN extract in drinking water with lime. Peripheral blood was collected from 32 human donors of which, 24 were RAN + lime heavy chewers. Expression of genes was assessed by immunoblotting and/or by immunohistochemistry. Histological preparation of stomach tissue of mice revealed that RAN + lime induced stomach cancer. A gradual increase in the frequency of precocious anaphases and aneuploid cells was observed in both RAN + lime-treated mouse BMC and human PBL of RAN heavy chewers. Levels of p53 and Securin were increased in these cells during early days of RAN + lime exposure. The level of Securin was significantly higher in human tumour samples than their adjacent normal counterpart. The expression of Securin was increased significantly in RAN + lime-administered mice as well as in stomach tumour. Present study revealed that precocious anaphase and expression of p53 and Securin in non-target cells are significantly associated with an increased risk of RAN-induced cancer and thus these parameters can be of early diagnostic value

  5. Precocious anaphase and expression of Securin and p53 genes as candidate biomarkers for the early detection in areca nut-induced carcinogenesis.

    Science.gov (United States)

    Kurkalang, Sillarine; Banerjee, Atanu; Dkhar, Hughbert; Nongrum, Henry B; Ganguly, Buddha; Islam, Mohammad; Rangad, Gordon M; Chatterjee, Anupam

    2015-05-01

    Research over the years has generated enough evidence to implicate areca nut, as a carcinogen in humans. Besides oral, significant rise in the incidence of cancers of the oesophagus, liver and stomach was seen among areca nut chewers. Early diagnosis seems key to understand the initial processes of carcinogenesis which is highly curable. In North-East India, betel quid contains raw areca nut (RAN), lime and small portion of betel leaf without any other constituents. This study was not intended to isolate any active ingredients from the RAN and to look its action. The present objective is to validate the screening of precocious anaphase and analysis of expression of Securin and p53 in non-target cells like human peripheral blood lymphocytes (PBLs) and mouse bone marrow cells (BMCs) as early indicative parameters of RAN + lime-induced cancers. A total of 35 mice were examined at different time points for following ad libitum administration of RAN extract in drinking water with lime. Peripheral blood was collected from 32 human donors of which, 24 were RAN + lime heavy chewers. Expression of genes was assessed by immunoblotting and/or by immunohistochemistry. Histological preparation of stomach tissue of mice revealed that RAN + lime induced stomach cancer. A gradual increase in the frequency of precocious anaphases and aneuploid cells was observed in both RAN + lime-treated mouse BMC and human PBL of RAN heavy chewers. Levels of p53 and Securin were increased in these cells during early days of RAN + lime exposure. The level of Securin was significantly higher in human tumour samples than their adjacent normal counterpart. The expression of Securin was increased significantly in RAN + lime-administered mice as well as in stomach tumour. Present study revealed that precocious anaphase and expression of p53 and Securin in non-target cells are significantly associated with an increased risk of RAN-induced cancer and thus these parameters can be of early diagnostic value.

  6. The epidemiology of Her-2/ neu and P53 in breast cancer Epidemiología de los genes Her2/neu y P53 en relación al cáncer mamario

    Directory of Open Access Journals (Sweden)

    Jonine L. Bernstein

    1999-11-01

    Full Text Available Breast cancer is an etiologically heterogeneous disease with marked geographical variations. Joint consideration of the relationship between specific molecular alterations and known or suspected epidemiologic risk factors for this disease should help distinguish subgroups of women that are at elevated risk of developing breast cancer. In this article, we present a comprehensive literature review of the etiologic and prognostic roles of Her-2/neu and P53 among women. In addition, we discuss the advantages and limitations of using biomarkers in epidemiological studies. We conclude that more research is needed to understand the complex relationships between genetic alterations and etiologic risk factors for breast cancer.El cáncer mamario es una enfermedad con gran variabilidad geográfica y cuya etiología es heterogénea. La evaluación conjunta de los factores de riesgo que se conocen por estudios epidemiológicos y de las alteraciones específicas a nivel molecular, podría ser útil para identificar subgrupos de mujeres con alto riesgo de padecer dicho tumor maligno. En este artículo presentamos una revisión de la literatura acerca del papel que el Her-2/neu y el P53 tienen en la etiología y el pronóstico del cáncer mamario en mujeres. Además, discutimos las ventajas y limitaciones de utilizar biomarcadores en los estudios epidemiológicos. Concluimos que se requieren nuevas investigaciones orientadas a dilucidar las complejas relaciones que existen entre las alteraciones genéticas y los factores de riesgo para el cáncer mamario.

  7. Urodele p53 tolerates amino acid changes found in p53 variants linked to human cancer

    Directory of Open Access Journals (Sweden)

    Villiard Éric

    2007-09-01

    Full Text Available Abstract Background Urodele amphibians like the axolotl are unique among vertebrates in their ability to regenerate and their resistance to develop cancers. It is unknown whether these traits are linked at the molecular level. Results Blocking p53 signaling in axolotls using the p53 inhibitor, pifithrin-α, inhibited limb regeneration and the expression of p53 target genes such as Mdm2 and Gadd45, suggesting a link between tumor suppression and regeneration. To understand this relationship we cloned the p53 gene from axolotl. When comparing its sequence with p53 from other organisms, and more specifically human we observed multiple amino acids changes found in human tumors. Phylogenetic analysis of p53 protein sequences from various species is in general agreement with standard vertebrate phylogeny; however, both mice-like rodents and teleost fishes are fast evolving. This leads to long branch attraction resulting in an artefactual basal emergence of these groups in the phylogenetic tree. It is tempting to assume a correlation between certain life style traits (e.g. lifespan and the evolutionary rate of the corresponding p53 sequences. Functional assays of the axolotl p53 in human or axolotl cells using p53 promoter reporters demonstrated a temperature sensitivity (ts, which was further confirmed by performing colony assays at 37°C. In addition, axolotl p53 was capable of efficient transactivation at the Hmd2 promoter but has moderate activity at the p21 promoter. Endogenous axolotl p53 was activated following UV irradiation (100 j/m2 or treatment with an alkylating agent as measured using serine 15 phosphorylation and the expression of the endogenous p53 target Gadd45. Conclusion Urodele p53 may play a role in regeneration and has evolved to contain multiple amino acid changes predicted to render the human protein defective in tumor suppression. Some of these mutations were probably selected to maintain p53 activity at low temperature. However

  8. 荧光原位杂交技术检测新疆慢性淋巴细胞白血病患者p53基因缺失及其临床意义%Detection of p53 gene deletion in Xinjiang patients with chronic lymphocytic leukemia by fluorescence in situ hybridization and its clinical significance

    Institute of Scientific and Technical Information of China (English)

    买买提力·依马木; 古再丽努尔·吾甫尔; 王晓敏; 刘虹; 李燕; 肖萌

    2014-01-01

    目的 探讨新疆慢性淋巴细胞白血病(chronic lymphocytic leukemia,CLL)患者临床特征及p53基因缺失的检出率及其临床意义.方法 应用荧光原位杂交(fluorescence in situ hybridization,FISH)技术对77例CLL患者进行p53基因缺失的检测,分析p53基因缺失对预后的价值及其与临床特征和部分预后参数的关系.单因素生存分析采用Kaplan-Meier法绘制生存曲线和Log-rank检验.结果 (1)77例CLL中,10例(12.9%)检测出p53缺失,而20例对照中均不存在p53缺失,差异有统计学意义(P<0.05).其中,32例汉族CLL中4例检测出p53缺失,45例维吾尔族CLL中6例检测出p53缺失,缺失率比较差异无统计学意义(P>0.05); p53基因缺失与患者性别、年龄、民族、外周血(除血红蛋白以外)、血清乳酸脱氢酶、β2-微球蛋白及CD38表达水平等无明显相关性(P>0.05),而与疾病后期及ZAP-70高表达有相关性(P<0.05).(2)20例患者接受含氟达拉滨方案治疗,其中p53基因缺失者5例,部份缓解1例,无1例达完全缓解,总缓解率为20%;p53基因无缺失者15例,部份缓解11例,完全缓解4例,总缓解率为75%,二者总缓解率比较差异有统计学意义(P<0.05).中位随访39.0(8.0~136.0)个月,死亡11例(14.3%),其中死于CLL及其相关并发症者7例,其他原因者4例.死亡的7例患者均伴有p53基因缺失.伴有p53基因缺失组无进展生存期(18个月)明显短于无p53基因缺失者(55个月),差异有统计学意义(P<0.05).结论 新疆10%以上CLL患者存在p53基因缺失,但维吾尔族和汉族CLL患者p53基因缺失率无差异,p53基因缺失与疾病后期及ZAP-70高表达有关,p53基因缺失者生存期较短,采用含氟达拉滨方案治疗总缓解率低于无缺失者,故应避免选择影响p53信号传导系统的药物.%Objective To investigate the presence of p53 gene deletion in Xinjiang patients with chronic lymphocytic leukemia and its clinical significance

  9. Establishment and identification of human osteosarcoma cell line stably expressing wild-type p53 gene%稳定表达野生型p53基因人骨肉瘤细胞株的建立与鉴定

    Institute of Scientific and Technical Information of China (English)

    雷晓晶; 韩鹏飞; 吕智

    2012-01-01

    目的 建立稳定表达外源性野生型p53基因的人骨肉瘤细胞株(u-2 OS),为进一步研究野生型p53基因在骨肉瘤自杀基因治疗中的协同作用提供体外实验模型建立与鉴定的方法. 方法 利用分子生物学基因克隆技术将人类野生型p53基因cDNA片段插入到表达载体pIRES-EGFP中,得到重组质粒pIRES-EGFP-p53,并通过PCR、酶切电泳等方法进行质粒鉴定;然后用该重组质粒转化大肠杆菌BL21细胞,转化菌落经PCR扩增后,将提取的质粒DNA用脂质体介导的转染方法导人U-2OS细胞中,经荧光显微镜下人工筛选得到稳定转染的骨肉瘤细胞系. 结果 成功地构建出包含有野生型p53 cDNA片段的重组质粒pIRES-EGFP-p53,通过PCR、酶切电泳等方法鉴定质粒大小和位点均符合实验设计;并将该重组质粒成功导人人骨肉瘤细胞株U-2OS细胞中,经荧光显微镜下人工筛选得到稳定转染的骨肉瘤细胞系,命名为u-2-p53 OS.转染后的骨肉瘤细胞出现散在的凋亡现象. 结论 利用基因转染技术,建立了稳定表达外源性野生型p53基因的人骨肉瘤U-2-p53 OS 细胞系,为进一步研究野生型p53基因在骨肉瘤自杀基因治疗中的协同作用奠定了基础.%Objective To establish an in vitro model of human osteosarcoma cell strain( U-2 OS) stably expressing the exogenetic wild-type p53 gene for further studying the role of wild-type p53 gene in osteosarcoma suicide gene therapy. Methods The molecular biology technology was used to insert the human wild-type p53 cDNA fragment into the expression vector pIRES-EGFP for obtaining the recombinant plasmid pIRES-EGFP-p53, and then it was identified by PCR, enzyme electrophoresis and other methods. Then the recom-binant plasmid was transformed into E. Coli BL21 cells. After the transformed colony was amplified by PCR,the plasmid DNA was trans-fected into U-2 OS cells by liposome-mediated transfection method. Under fluorescence microscopy

  10. Silver Nanoparticles Biosynthesized Using Achillea biebersteinii Flower Extract: Apoptosis Induction in MCF-7 Cells via Caspase Activation and Regulation of Bax and Bcl-2 Gene Expression

    Directory of Open Access Journals (Sweden)

    Javad Baharara

    2015-02-01

    Full Text Available Silver nanoparticles (Ag-NPs, the most popular nanoparticles, possess unique properties. Achillea biebersteinii is a plant of the Asteraceae family rich in active antitumor components. The aim of this research was the characterization and investigation of the cytotoxic properties of Ag-NPs synthesized using A. biebersteinii flower extract, on a human breast cancer cell line. The Ag-NPs were synthesized after approximately 180 min of reaction at 40 °C, then they were characterized by UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR, transmission electron microscopy (TEM and dynamic light scattering (DLS. The anti-apoptosis effect of Ag-NPs on the MCF-7 cell line was investigated by MTT assay, DAPI and acridine orange staining and caspase activity. The transcriptional expression of bax, bcl-2, caspase-3, -8 and -9 were also evaluated by RT-PCR. The TEM images revealed that the Ag-NPs morphology had a different shape. The DLS indicated that the average hydrodynamic diameter of the biosynthesized Ag-NPs was around 12 nm. By UV-visible spectroscopy the strongest absorbance peak was observed at 460 nm. The FTIR results also showed interaction between the plant extract and Ag-NPs due to the similarity in the peak patterns. The EDS results showed that Ag-NPs display an absorption peak at 3 keV, indicating the presence of the element silver. The Ag-NPs caused a dose-dependent decrease in cell viability, fragmentation in nucleic acid, inhibited the proliferation and induction of apoptosis on MCF-7 by suppressing specific cell cycle genes, and simulation programmed cell dead genes. Further investigation is required to establish the potential of this novel and promising approach in cancer therapy.

  11. p53 mutations increase resistance to ionizing radiation

    International Nuclear Information System (INIS)

    Mouse and human tumors of diverse origin frequently have somatically acquired mutations or rearrangements of the p53 gene, or they have lost one or both copies of the gene. Although wild-type p53 protein is believed to function as a tumor-suppressor gene, it is as yet unclear how p53 mutations lead to neoplastic development. Wild-type p53 has been postulated to play a role in DNA repair, suggesting that expression of mutant forms of p53 might alter cellular resistance to the DNA damage caused by γ radiation. Moreover, p53 is thought to function as a cell cycle checkpoint after irradiation, also suggesting that mutant p53 might change the cellular proliferative response to radiation. The authors have used transgenic mice expressing one of two mutant alleles of p53 to test this prediction. Their results show that expression of both mutant variants of the mouse p53 gene significantly increases the cellular resistance of a variety of hematopoietic cell lineages to γ radiation. These observations provide direct evidence that p53 mutations affect the cellular response to DNA damage, either by increasing DNA repair processes or, possibly, by increasing cellular tolerance to DNA damage. The association of p53 mutations with increased radioresistance suggests possible mechanisms through which alterations in the p53 gene might lead to oncogenic transformation. 53 refs., 5 figs

  12. 理冲汤对体外培养人子宫肌瘤细胞p53信号通路基因表达谱的影响%Effect of Lichong Decoction on p53 Signaling Pathway Gene Expression Profile in Human Uterine Leiomyoma Cells in vitro

    Institute of Scientific and Technical Information of China (English)

    李冬华; 谢小磊; 张亚兰; 耿建国; 白霞; 张炎

    2011-01-01

    目的:研究理冲汤对体外培养人子宫肌瘤细胞p53信号通路基因表达谱的影响.方法:体外原代培养子宫肌瘤细胞并传代后,加入理冲汤含药血清,继续培养.选用功能分类PCR p53信号通路基因芯片(PCR p53 Signaling Pathway Microarray),从空白对照组、理冲汤组子宫肌瘤细胞中进行样品的RNA抽提及纯化,采用紫外吸收测定法及变性琼脂糖凝胶电泳进行RNA质量检测,合成cDNA,最后进行实时定量PCR.结果:所采用的PCR p53信号通路基因芯片共检测96条基因,理冲汤组与空白对照组比较,共17条(17.7%)基因表达发生明显变化,其中10条基因表达量明显下降(Fold Down-Regulation<-2),7条基因表达量上升(Fold Up-Regulation >2).按功能将其进行大体分类,涉及到细胞凋亡、细胞周期、细胞生长增殖和分化、DNA修复等多方面.结论:理冲汤对子宫肌瘤p53信号通路的细胞凋亡、细胞周期、细胞生长增殖和分化、DNA修复等相关基因均有调节作用,提示细胞内外的信号传导是子宫肌瘤发病的关键环节,理冲汤对子宫肌瘤p53信号通路相关基因表达具有调控作用.%Objective;To study the effect of Lichong decoction on p53 signaling pathway gene expression profile in human uterine leiomyoma cells in vitro. Method; The primary cultured uterine leiomyoma cells were treated with Lichong decoction. Using PCR p53 signaling pathway microarray, all RNA was gained and cleanuped from human uterine leiomyoma cells in blank control group and Lichong decoction group. RNA yield and quality were assessed by UV absorbance and denaturing agarose gel electrophoresis, first strand cDNA Synthesis, performing Real-Time PCR finally. Result; Lichong decoction group was compared with blank control group among 96 pieces genes in PCR p53 signaling pathway microarray, 17 in total( 17. 7% ) genes expression had obviouslychanged, 10 pieces went down obviously ( Fold Down-Regulation 2 ). The

  13. The expression of p16, p53 induced by metallic biliary stent in canine

    International Nuclear Information System (INIS)

    Objective: To explore the value of the metallic biliary stents in inducing the expression of anti-oncogenes. Methods: The biliary stents were implanted in the inferior segments of CBD after a percutaneous transhepatic puncture at cholecyst in 24 dogs. After a generally observing time of half a year, the median abdominal incisions were made on the dogs under general anesthesia and the bile duct wall covered by the stents (group I) and uncovered (group II) were cut respectively. The expression of p16, p53, p15, Bcl-2 and K-ras in bile duct wall were detected by RT-PCR, and the positive rates of these gene expression were calculated. The differences between the two groups were analyzed by chi-square test for the statistics. Results: The animal models were successfully set in 20 of 24 dogs. The positive rates of p16, p53 gene expression were 80% (16/20), 45% (9/20) in the bile duct wall covered by the stents and 15% (3/20), 0% in the bile duct wall uncovered respectively, there were significant differences between the two groups (χ2=16.94, 9.17, P0.05). Conclusion: The enhancement of p16, p53 gene expression have some correlations with the implantation of metallic biliary stents. The biliary stenting is strongly recommended for the patients with malignant obstructive jaundice when no contraindications exist. (authors)

  14. Quaternary structure of the specific p53–DNA complex reveals the mechanism of p53 mutant dominance

    OpenAIRE

    Aramayo, Ricardo; Sherman, Michael B.; Brownless, Kathryne; Lurz, Rudi; Okorokov, Andrei L.; Orlova, Elena V

    2011-01-01

    The p53 tumour suppressor is a transcriptional activator that controls cell fate in response to various stresses. p53 can initiate cell cycle arrest, senescence and/or apoptosis via transactivation of p53 target genes, thus preventing cancer onset. Mutations that impair p53 usually occur in the core domain and negate the p53 sequence-specific DNA binding. Moreover, these mutations exhibit a dominant negative effect on the remaining wild-type p53. Here, we report the cryo electron microscopy s...

  15. 亚砷酸钠对人肺癌Spc-A1细胞Bcl-2、Fas表达的影响%The effect of apoptosis-related gene Bcl-2 and Fas of sodium arsenic on Spc-A1 cell

    Institute of Scientific and Technical Information of China (English)

    施睿; 梁标

    2011-01-01

    arsenite could obviously inhibit the proliferation of Spc - A1 cell ,induce cell cycle arrest and apoptosis and necrosis of the cella.The down - regulation of Bcl -2 gene and up - regulation of Fas gene may be one of the mechanisms.

  16. p53 activated by AND gate genetic circuit under radiation and hypoxia for targeted cancer gene therapy.

    Science.gov (United States)

    Ding, Miao; Li, Rong; He, Rong; Wang, Xingyong; Yi, Qijian; Wang, Weidong

    2015-09-01

    Radio-activated gene therapy has been developed as a novel therapeutic strategy against cancer; however, expression of therapeutic gene in peritumoral tissues will result in unacceptable toxicity to normal cells. To restrict gene expression in targeted tumor mass, we used hypoxia and radiation tolerance features of tumor cells to develop a synthetic AND gate genetic circuit through connecting radiation sensitivity promoter cArG6 , heat shock response elements SNF1, HSF1 and HSE4 with retroviral vector plxsn. Their construction and dynamic activity process were identified through downstream enhanced green fluorescent protein and wtp53 expression in non-small cell lung cancer A549 cells and in a nude mice model. The result showed that AND gate genetic circuit could be activated by lower required radiation dose (6 Gy) and after activated, AND gate could induce significant apoptosis effects and growth inhibition of cancer cells in vitro and in vivo. The radiation- and hypoxia-activated AND gate genetic circuit, which could lead to more powerful target tumoricidal activity represented a promising strategy for both targeted and effective gene therapy of human lung adenocarcinoma and low dose activation character of the AND gate genetic circuit implied that this model could be further exploited to decrease side-effects of clinical radiation therapy.

  17. Dietary selenomethionine intake increases exon-specific DNA methylation of p53 gene in rat liver and colon mucosa

    Science.gov (United States)

    The regulation of site-specific DNA methylation of tumor suppressor genes has been considered as a leading mechanism by which certain nutrients exert their anticancer property. Our previous studies suggest that dietary selenium (Se) may alter DNA methylation, and the purpose of this study was to inv...

  18. Pre-irradiation with low-dose 12C6+ beam significantly enhances the efficacy of AdCMV-p53 gene therapy in human non-small lung cancer

    Institute of Scientific and Technical Information of China (English)

    LIU Bing; DUAN Xin; ZHANG Hong; LI WenJian; LI Qiang; ZHOU GuangMing; XIE Yi; HAO JiFang; MIN FengLing; ZHOU QingMing

    2007-01-01

    The combination of ionizing radiation and gene therapy has been investigated. However, there are very few reports about the combination of heavy-ion irradiation and gene therapy. To determine if the pre-exposure to low-dose heavy ion beam enhances the suppression of AdCMV-p53 on non-small lung cancer (NSLC), the cells pre-irradiated or non-irradiated were infected with 20, 40 MOl of AdCMV-p53. Survival fraction and the relative biology effect (RBE) were determined by clonogenic assay. The results showed that the proportions of p53 positive cells in 12C6+ beam induced AdCMV-p53 infected cells were more than 90%, which were significantly more than those in γ-ray induced AdCMV-p53 infected cells. The pre-exposure to low-dose 12C6+ beam significantly prevented the G0/G1 arrest and activated G2/M checkpoints. The pre-exposure to 12C6+ beam significantly improved cell to apoptosis. RBEs for the 12C6+ + AdCMV-p53 infection groups were 30%-60%, 20% -130% and 30%-70% more than those for the 12C6+-irradiated only, AdCMV-p53 infected only, and γ-irradiation induced AdCMVp53 infected groups, respectively. The data suggested that the pre-exposure to low-dose 12C6+ beam significantly promotes exogenous p53 expression in NSLC, and the suppression of AdCMV-p53 gene therapy on NSLC.

  19. Pre-irradiation with low-dose 12C6+ beam significantly enhances the efficacy of AdCMV-p53 gene therapy in human non-small lung cancer

    Science.gov (United States)

    Liu, Bing; Zhang, Hong; Li, Wenjian; Li, Qiang; Zhou, Guangming; Xie, Yi; Hao, Jifang; Min, Fengling; Zhou, Qingming; Duan, Xin

    2007-04-01

    The combination of ionizing radiation and gene therapy has been investigated. However, there are very few reports about the combination of heavy-ion irradiation and gene therapy. To determine if the pre-exposure to low-dose heavy ion beam enhances the suppression of AdCMV-p53 on non-small lung cancer (NSLC), the cells pre-irradiated or non-irradiated were infected with 20, 40 MOI of AdCMV-p53. Survival fraction and the relative biology effect (RBE) were determined by clonogenic assay. The results showed that the proportions of p53 positive cells in 12C6+ beam induced AdCMV-p53 infected cells were more than 90%, which were significantly more than those in γ-ray induced AdCMV-p53 infected cells. The pre-exposure to low-dose 12C6+ beam significantly prevented the G0/G1 arrest and activated G2/M checkpoints. The pre-exposure to 12C6+ beam significantly improved cell to apoptosis. RBEs for the 12C6+ + AdCMV-p53 infection groups were 30% 60%, 20% 130% and 30% 70% more than those for the 12C6+-irradiated only, AdCMV-p53 infected only, and γ-irradiation induced AdCMVp53 infected groups, respectively. The data suggested that the pre-exposure to low-dose 12C6+ beam significantly promotes exogenous p53 expression in NSLC, and the suppression of AdCMV-p53 gene therapy on NSLC.

  20. Pre-irradiation with low-dose 12C6+beam significantly enhances the efficacy of AdCMV-p53 gene therapy in human non-small lung cancer

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The combination of ionizing radiation and gene therapy has been investigated. However, there are very few reports about the combination of heavy-ion irradiation and gene therapy. To determine if the pre-exposure to low-dose heavy ion beam enhances the suppression of AdCMV-p53 on non-small lung cancer (NSLC), the cells pre-irradiated or non-irradiated were infected with 20, 40 MOI of AdCMV-p53. Survival fraction and the relative biology effect (RBE) were determined by clonogenic assay. The results showed that the proportions of p53 positive cells in 12C6+ beam induced AdCMV-p53 infected cells were more than 90%, which were signifi-cantly more than those in γ-ray induced AdCMV-p53 infected cells. The pre-exposure to low-dose 12C6+ beam significantly prevented the G0/G1 arrest and activated G2/M checkpoints. The pre-exposure to 12C6+ beam significantly improved cell to apoptosis. RBEs for the 12C6+ + AdCMV-p53 infection groups were 30%-60%, 20%-130% and 30%-70% more than those for the 12C6+-irradiated only, AdCMV-p53 infected only, and γ-irradiation induced AdCMVp53 infected groups, respectively. The data suggested that the pre-exposure to low-dose 12C6+ beam significantly promotes exogenous p53 expression in NSLC, and the suppression of AdCMV-p53 gene therapy on NSLC.

  1. Cellular adaptation to hypoxia and p53 transcription regulation

    Institute of Scientific and Technical Information of China (English)

    Yang ZHAO; Xue-qun CHEN; Ji-zeng DU

    2009-01-01

    Tumor suppressor p53 is the most frequently mutated gene in human tumors. Meanwhile, under stress conditions, p53 also acts as a transcription factor, regulating the expression of a series of target genes to maintain the integrity of genome. The target genes of p53 can be classified into genes regulating cell cycle arrest, genes involved in apoptosis, and genes inhibiting angiogenesis. p53 protein contains a transactivation domain, a sequence-specific DNA binding domain, a tetramerization domain, a non-specific DNA binding domain that recognizes damaged DNA, and a later identified proline-rich domain. Under stress, p53 proteins accumulate and are activated through two mechanisms. One, involving ataxia telangiectasia-mutated protein (ATM), is that the interaction between p53 and its down-regulation factor murine double minute 2 (MDM2) decreases, leading to p53 phosphorylation on Ser15, as determined by the post-translational mechanism; the other holds that p53 increases and is activated through the binding of ribosomal protein L26 (RPL26) or nucleolin to p53 mRNA 5' untranslated region (UTR), regulating p53 translation. Under hypoxia, p53 decreases transactivation and increases transrepression. The mutations outside the DNA binding domain of p53 also contribute to tumor progress, so further studies on p53 should also be focused on this direction. The subterranean blind mole rat Spalax in Israel is a good model for hypoxia-adaptation. The p53 of Spalax mutated in residue 172 and residue 207 from arginine to lysine, conferring it the ability to survive hypoxic conditions. This model indicates that p53 acts as a master gene of diversity formation during evolution.

  2. p53 regulates the transcription of its Delta133p53 isoform through specific response elements contained within the TP53 P2 internal promoter.

    Science.gov (United States)

    Marcel, V; Vijayakumar, V; Fernández-Cuesta, L; Hafsi, H; Sagne, C; Hautefeuille, A; Olivier, M; Hainaut, P

    2010-05-01

    The tumor suppressor p53 protein is activated by genotoxic stress and regulates genes involved in senescence, apoptosis and cell-cycle arrest. Nine p53 isoforms have been described that may modulate suppressive functions of the canonical p53 protein. Among them, Delta133p53 lacks the 132 proximal residues and has been shown to modulate p53-induced apoptosis and cell-cycle arrest. Delta133p53 is expressed from a specific mRNA, p53I4, driven by an alternative promoter P2 located between intron 1 and exon 5 of TP53 gene. Here, we report that the P2 promoter is regulated in a p53-dependent manner. Delta133p53 expression is increased in response to DNA damage by doxorubicin in p53 wild-type cell lines, but not in p53-mutated cells. Chromatin immunoprecipitation and luciferase assays using P2 promoter deletion constructs indicate that p53 binds functional response elements located within the P2 promoter. We also show that Delta133p53 does not bind specifically to p53 consensus DNA sequence in vitro, but competes with wild-type p53 in specific DNA-binding assays. Finally, we report that Delta133p53 counteracts p53-dependent growth suppression in clonogenic assays. These observations indicate that Delta133p53 is a novel target of p53 that may participate in a negative feedback loop controlling p53 function. PMID:20190805

  3. P-Glycoprotein/MDR1 Regulates Pokemon Gene Transcription Through p53 Expression in Human Breast Cancer Cells

    OpenAIRE

    Wei Xu; Yuyang Jiang; Xuyu Zu; Shengnan He; Zhenhua Xie; Feng Liu(Central China Normal University)

    2010-01-01

    P-glycoprotein (Pgp), encoded by the multidrug resistance 1 (MDR1) gene, is an efflux transporter and plays an important role in pharmacokinetics. In this study, we demonstrated that the pokemon promoter activity, the pokemon mRNA and protein expression can be significantly inhibited by Pgp. Chromatin immunoprecipitation assay showed that Pgp can bind the pokemon prompter to repress pokemon transcription activity. Furthermore, Pgp regulated pokemon transcription activity through expression of...

  4. Targeting Oncogenic Mutant p53 for Cancer Therapy

    OpenAIRE

    Parrales, Alejandro; Iwakuma, Tomoo

    2015-01-01

    Among genetic alterations in human cancers, mutations in the tumor suppressor p53 gene are the most common, occurring in over 50% of human cancers. The majority of p53 mutations are missense mutations and result in the accumulation of dysfunctional p53 protein in tumors. These mutants frequently have oncogenic gain-of-function activities and exacerbate malignant properties of cancer cells, such as metastasis and drug resistance. Increasing evidence reveals that stabilization of mutant p53 in ...

  5. Modulation of p53's transcriptional function by small molecules

    OpenAIRE

    Nikulenkov, Fedor

    2011-01-01

    p53 tumour suppressor is a transcriptional factor which induces apoptosis or growth arrest in response to stress thus eliminating damaged cells. p53 function is frequently abrogated in tumours either via inactivation mutations in the TP53 gene or by elevated activity of p53 negative regulators HDM2 and HDMX. Therefore application of small molecules that reactivate p53 function is a promising strategy for anti-cancer therapy. In addition, small molecules can serve as valuable research tool to ...

  6. Regulation of Caspase-3 and Bcl-2 Expression in Dalton's Lymphoma Ascites Cells by Abrin

    Directory of Open Access Journals (Sweden)

    V. Ramnath

    2009-01-01

    Full Text Available The role of abrin, a toxic lectin isolated from seeds of Abrus precatorius Linn in inducing apoptosis in murine Dalton's Lymphoma Ascites (DLA cells was evaluated. Abrin when incubated at the concentration of 10 ng per million DLA cells could bring about cell death as typical morphological changes with apoptosis. However, necrotic cell death dominated when a higher dose of abrin was used. DNA samples, isolated from DLA cells treated with abrin showed fragmentation. Abrin brought about induction of apoptosis by stimulating the expression of pro-apoptotic Caspase-3, at the same time blocking the expression of Bcl-2, which is an anti apoptotic gene. However, the expression of tumor suppressor gene p53 has not been observed in control and abrin-treated DLA cells. Results suggested that abrin effectively induced apoptotic changes in the tumor cells that led to cellular death.

  7. The Hippo pathway acts via p53 and microRNAs to control proliferation and proapoptotic gene expression during tissue growth

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2013-06-01

    The Hippo pathway has a central role in coordinating tissue growth and apoptosis. Mutations that compromise Hippo pathway activity cause tissue overgrowth and have been causally linked to cancer. In Drosophila, the transcriptional coactivator Yorkie mediates Hippo pathway activity to control the expression of cyclin E and Myc to promote cell proliferation, as well as the expression of bantam miRNA and DIAP1 to inhibit cell death. Here we present evidence that the Hippo pathway acts via Yorkie and p53 to control the expression of the proapoptotic gene reaper. Yorkie further mediates reaper levels post-transcriptionally through regulation of members of the miR-2 microRNA family to prevent apoptosis. These findings provide evidence that the Hippo pathway acts via several distinct routes to limit proliferation-induced apoptosis.

  8. Effect of pH on the Interaction of Gold Nanoparticles with DNA and Application in the Detection of Human p53 Gene Mutation

    Directory of Open Access Journals (Sweden)

    Sun Liping

    2008-01-01

    Full Text Available Abstract Gold nanoparticles (GNPs are widely used to detect DNA. We studied the effect of pH on the assembly/disassembly of single-stranded DNA functionalized GNPs. Based on the different binding affinities of DNA to GNPs, we present a simple and fast way that uses HCl to drive the assembly of GNPs for detection of DNA sequences with single nucleotide differences. The assembly is reversible and can be switched by changing the solution pH. No covalent modification of DNA or GNP surface is needed. Oligonucleotide derived from human p53 gene with one-base substitution can be distinguished by a color change of the GNPs solution or a significant difference of the maximum absorption wavelength (λmax, compared with wildtype sequences. This method enables detection of 10 picomole quantities of target DNA.

  9. Specific UV-induced mutation spectrum in the p53 gene of skin tumors from DNA-repair-deficient xeroderma pigmentosum patients

    International Nuclear Information System (INIS)

    The UV component of sunlight is the major carcinogen involved in the etiology of skin cancers. The authors have studied the rare, hereditary syndrome xeroderma pigmentosum (XP), which is characterized by a very high incidence of cutaneous tumors on exposed skin at an early age, probably due to a deficiency in excision repair of UV-induced lesions. It is interesting to determine the UV mutation spectrum in XP skin tumors in order to correlate the absence of repair of specific DNA lesions and the initiation of skin tumors. The p53 gene is frequently mutated in human cancers and represents a good target for studying mutation spectra since there are >100 potential sites for phenotypic mutations. Using reverse transcription-PCR and single-strand conformation polymorphism to analyze >40 XP skin tumors (mainly basal and squamous cell carcinomas), the authors have found that 40% (17 out of 43) contained at least one point mutation on the p53 gene. All the mutations were located at dipyrimidine sites, essentially at CC sequences, which are hot spots for UV-induced DNA lesions. Sixty-one percent of these mutations were tandem CC → TT mutations considered to be unique to UV-induced lesions; these mutations are not observed in internal human tumors. All the mutations, except two, must be due to translesion synthesis of unrepaired dipyrimidine lesions left on the nontranscribed strand. These results show the existence of preferential repair of UV lesions [either pyrimidine dimers or pyrimidine-pyrimidone (6-4) photoproducts] on the transcribed strand in human tissues

  10. Chromosomal gains and genomic loss of p53 and p16 genes in Barrett's esophagus detected by fluorescence in situ hybridization of cytology specimens.

    Science.gov (United States)

    Fahmy, Mona; Skacel, Marek; Gramlich, Terry L; Brainard, Jennifer A; Rice, Thomas W; Goldblum, John R; Connor, Jason T; Casey, Graham; Legator, Mona S; Tubbs, Raymond R; Falk, Gary W

    2004-05-01

    Endoscopic brush cytology is a promising surveillance technique for Barrett's esophagus. Ancillary markers are sought to increase the sensitivity of cytology and allow identification of patients at increased risk for disease progression. To determine if there are specific genetic changes in Barrett's esophagus with associated high-grade dysplasia/intramucosal adenocarcinoma compared to those without dysplasia, we performed fluorescence in situ hybridization (FISH) on cytologic specimens using probes to chromosomes and genomic regions previously described as altered in this disease. We studied archival brush cytology slides from 40 Barrett's esophagus patients: 21 with biopsy-proven high-grade dysplasia/carcinoma and 19 with no dysplasia and a minimum 5 years of negative follow-up. Centromeric enumeration probes (CEP) for chromosomes 6, 7, 11, and 12, and locus-specific probes (LSI) for 9p21 (p16 gene), and 17p13.1 (p53 gene) loci along with their corresponding CEP (9 and 17, respectively) were used in this study. A positive FISH result was defined as the presence of cells with >2 CEP signals or with a loss of the LSI signals relative to their corresponding CEP. p53 locus loss and/or aneusomy of chromosomes 6, 7, 11, and 12 abnormalities could be detected by FISH in routinely processed endoscopic brush cytology specimens from 95% of biopsy-positive cases with a specificity of 100%. Interestingly, all five cases with cytologic changes classified as indefinite for dysplasia from patients with a positive biopsy showed changes by FISH. Loss of the p16 locus was seen commonly in patients both with and without dysplasia/carcinoma. Selected biomarkers from this study merit further investigation to determine their potential to detect genetic changes in patients with Barrett's esophagus prior to the development of high-grade dysplasia. PMID:15017433

  11. p53 Cellular Localization and Function in Neuroblastoma

    Science.gov (United States)

    Tweddle, Deborah A.; Malcolm, Archie J.; Cole, Michael; Pearson, Andrew D.J.; Lunec, John

    2001-01-01

    This study investigated the hypothesis that p53 accumulation in neuroblastoma, in the absence of mutation, is associated with functional inactivation, which interferes with downstream mediators of p53 function. To test this hypothesis, p53 expression, location, and functional integrity was examined in neuroblastoma by irradiating 6 neuroblastoma cell lines and studying the effects on p53 transcriptional function, cell cycle arrest, and induction of apoptosis, together with the transcriptional function of p53 after irradiation in three ex vivo primary, untreated neuroblastoma tumors. p53 sequencing showed five neuroblastoma cell lines, two of which were MYCN-amplified, and that all of the tumors were wild-type for p53. p53 was found to be predominantly nuclear before and after irradiation and to up-regulate the p53 responsive genes WAF1 and MDM2 in wild-type p53 cell lines and a poorly-differentiated neuroblastoma, but not a differentiating neuroblastoma or the ganglioneuroblastoma part of a nodular ganglioneuroblastoma in short term culture. This suggests intact p53 transcriptional activity in proliferating neuroblastoma. Irradiation of wild-type p53 neuroblastoma cell lines led to G1 cell cycle arrest in cell lines without MYCN amplification, but not in those with MYCN amplification, despite induction of WAF1. This suggests MYCN amplification may alter downstream mediators of p53 function in neuroblastoma. PMID:11395384

  12. Dual Roles of MDM2 in the Regulation of p53: Ubiquitination Dependent and Ubiquitination Independent Mechanisms of MDM2 Repression of p53 Activity

    OpenAIRE

    Shi, Dingding; Gu, Wei

    2012-01-01

    MDM2 oncogenic protein is the principal cellular antagonist of the p53 tumor suppresser gene. p53 activity needs exquisite control to elicit appropriate responses to differential cellular stress conditions. p53 becomes stabilized and active upon various types of stresses. However, too much p53 is not beneficial to cells and causes lethality. At the steady state, p53 activity needs to be leashed for cell survival. Early studies suggested that the MDM2 oncoprotein negatively regulates p53 activ...

  13. P53 Mdm2 Inhibitors

    NARCIS (Netherlands)

    Khoury, Kareem; Doemling, Alex

    2012-01-01

    The protein-protein interaction (PPI) between p53 and its negative regulator MDM2 comprises one of the most important and intensely studied PPI's involved in preventing the initiation of cancer. The interaction between p53 and MDM2 is conformation-based and is tightly regulated on multiple levels. D

  14. Tumor suppressor p53 meets microRNAs

    Institute of Scientific and Technical Information of China (English)

    Zhaohui Feng; Cen Zhang; Rui Wu; Wenwei Hu

    2011-01-01

    Tumor suppressor p53 plays a central role in tumor prevention. As a transcription factor, p53 mainly exerts its function through transcription regulation of its target genes to initiate various cellular responses. To maintain its proper function, p53 is tightly regulated by a wide variety of regulators in cells. Thus, p53, its regulators and regulated genes form a complex p53 network which is composed of hundreds of genes and their products. microRNAs (miRNAs) are a class of endogenously expressed, small non-coding RNA molecules which play a key role in regulation of gene expression at the post-transcriptional level. Recent studies have demonstrated that miRNAs interact with p53 and its network at multiple levels. p53 regulates the transcription expression and the maturation of a group of miRNAs. On the other hand, miRNAs can regulate the activity and function of p53 through direct repression of p53 or its regulators in cells. These findings have demonstrated that miRNAs are important components in the p53 network, and also added another layer of complexity to the p53 network.

  15. p53 in stem cells

    Institute of Scientific and Technical Information of China (English)

    Valeriya; Solozobova; Christine; Blattner

    2011-01-01

    p53 is well known as a "guardian of the genome" for differentiated cells,in which it induces cell cycle arrest and cell death after DNA damage and thus contributes to the maintenance of genomic stability.In addition to this tumor suppressor function for differentiated cells,p53 also plays an important role in stem cells.In this cell type,p53 not only ensures genomic integrity after genotoxic insults but also controls their proliferation and differentiation.Additionally,p53 provides an effective barrier for the generation of pluripotent stem celllike cells from terminally differentiated cells.In this review,we summarize our current knowledge about p53 activities in embryonic,adult and induced pluripotent stem cells.

  16. G-actin guides p53 nuclear transport: potential contribution of monomeric actin in altered localization of mutant p53

    Science.gov (United States)

    Saha, Taniya; Guha, Deblina; Manna, Argha; Panda, Abir Kumar; Bhat, Jyotsna; Chatterjee, Subhrangsu; Sa, Gaurisankar

    2016-01-01

    p53 preserves genomic integrity by restricting anomaly at the gene level. Till date, limited information is available for cytosol to nuclear shuttling of p53; except microtubule-based trafficking route, which utilizes minus-end directed motor dynein. The present study suggests that monomeric actin (G-actin) guides p53 traffic towards the nucleus. Histidine-tag pull-down assay using purified p53(1–393)-His and G-actin confirms direct physical association between p53 and monomeric G-actin. Co-immunoprecipitation data supports the same. Confocal imaging explores intense perinuclear colocalization between p53 and G-actin. To address atomistic details of the complex, constraint-based docked model of p53:G-actin complex was generated based on crystal structures. MD simulation reveals that p53 DNA-binding domain arrests very well the G-actin protein. Docking benchmark studies have been carried out for a known crystal structure, 1YCS (complex between p53DBD and BP2), which validates the docking protocol we adopted. Co-immunoprecipitation study using “hot-spot” p53 mutants suggested reduced G-actin association with cancer-associated p53 conformational mutants (R175H and R249S). Considering these findings, we hypothesized that point mutation in p53 structure, which diminishes p53:G-actin complexation results in mutant p53 altered subcellular localization. Our model suggests p53Arg249 form polar-contact with Arg357 of G-actin, which upon mutation, destabilizes p53:G-actin interaction and results in cytoplasmic retention of p53R249S. PMID:27601274

  17. G-actin guides p53 nuclear transport: potential contribution of monomeric actin in altered localization of mutant p53.

    Science.gov (United States)

    Saha, Taniya; Guha, Deblina; Manna, Argha; Panda, Abir Kumar; Bhat, Jyotsna; Chatterjee, Subhrangsu; Sa, Gaurisankar

    2016-01-01

    p53 preserves genomic integrity by restricting anomaly at the gene level. Till date, limited information is available for cytosol to nuclear shuttling of p53; except microtubule-based trafficking route, which utilizes minus-end directed motor dynein. The present study suggests that monomeric actin (G-actin) guides p53 traffic towards the nucleus. Histidine-tag pull-down assay using purified p53(1-393)-His and G-actin confirms direct physical association between p53 and monomeric G-actin. Co-immunoprecipitation data supports the same. Confocal imaging explores intense perinuclear colocalization between p53 and G-actin. To address atomistic details of the complex, constraint-based docked model of p53:G-actin complex was generated based on crystal structures. MD simulation reveals that p53 DNA-binding domain arrests very well the G-actin protein. Docking benchmark studies have been carried out for a known crystal structure, 1YCS (complex between p53DBD and BP2), which validates the docking protocol we adopted. Co-immunoprecipitation study using "hot-spot" p53 mutants suggested reduced G-actin association with cancer-associated p53 conformational mutants (R175H and R249S). Considering these findings, we hypothesized that point mutation in p53 structure, which diminishes p53:G-actin complexation results in mutant p53 altered subcellular localization. Our model suggests p53Arg249 form polar-contact with Arg357 of G-actin, which upon mutation, destabilizes p53:G-actin interaction and results in cytoplasmic retention of p53R249S. PMID:27601274

  18. The p53 Isoform Δ133p53β Promotes Cancer Stem Cell Potential

    Directory of Open Access Journals (Sweden)

    Nikola Arsic

    2015-04-01

    Full Text Available Cancer stem cells (CSC are responsible for cancer chemoresistance and metastasis formation. Here we report that Δ133p53β, a TP53 splice variant, enhanced cancer cell stemness in MCF-7 breast cancer cells, while its depletion reduced it. Δ133p53β stimulated the expression of the key pluripotency factors SOX2, OCT3/4, and NANOG. Similarly, in highly metastatic breast cancer cells, aggressiveness was coupled with enhanced CSC potential and Δ133p53β expression. Like in MCF-7 cells, SOX2, OCT3/4, and NANOG expression were positively regulated by Δ133p53β in these cells. Finally, treatment of MCF-7 cells with etoposide, a cytotoxic anti-cancer drug, increased CSC formation and SOX2, OCT3/4, and NANOG expression via Δ133p53