Objective: To explore the changes and significance of tumor suppressor gene p53 in primary hepatocellu-lar carcinoma (PHC ) with hepatitis B virus (HBV ) infection. Methods: Tumor tissues and surrounding nontumortissu...Objective: To explore the changes and significance of tumor suppressor gene p53 in primary hepatocellu-lar carcinoma (PHC ) with hepatitis B virus (HBV ) infection. Methods: Tumor tissues and surrounding nontumortissues of sixteen PHC cases were studied by Southern hybridization to detect the state of HBV-DNA in tissues, byimmunohistochemical staining to determine HBsAg, HBxAg and p53 protein, and by PCR directed sequencing toanalyse the point mutation of p53 gene exons 5 to 8. Results: Among the 16 cases. 13 cases were HBV-DNA posi-tive, 10 tumor cases and 13 nontumor tissues cases HBxAg positive, and 9 cases posltive for p53 protein. The se-quencing of p53 gene point mutation was found in 5 cases, only one of which was sited at codon 249 G to T. Con-clusion: The mutation of p53 gene codon 249 is infrequent in HBV related PHC,indicating the accumulation of p53protein in cells may be associated with expression of HBxAg. HBxAg binding to p53 protein and inactivation of p53function play important roles in the development of PHC.展开更多
In the world,hepatocellular carcinoma(HCC)is among the top 10 most prevalent malignancies.HCC formation has indeed been linked to numerous etiological factors,including alcohol usage,hepatitis viruses and liver cirrho...In the world,hepatocellular carcinoma(HCC)is among the top 10 most prevalent malignancies.HCC formation has indeed been linked to numerous etiological factors,including alcohol usage,hepatitis viruses and liver cirrhosis.Among the most prevalent defects in a wide range of tumours,notably HCC,is the silencing of the p53 tumour suppressor gene.The control of the cell cycle and the preservation of gene function are both critically important functions of p53.In order to pinpoint the core mechanisms of HCC and find more efficient treatments,molecular research employing HCC tissues has been the main focus.Stimulated p53 triggers necessary reactions that achieve cell cycle arrest,genetic stability,DNA repair and the elimination of DNA-damaged cells’responses to biological stressors(like oncogenes or DNA damage).To the contrary hand,the oncogene protein of the murine double minute 2(MDM2)is a significant biological inhibitor of p53.MDM2 causes p53 protein degradation,which in turn adversely controls p53 function.Despite carrying wt-p53,the majority of HCCs show abnormalities in the p53-expressed apoptotic pathway.High p53 in-vivo expression might have two clinical impacts on HCC:(1)Increased levels of exogenous p53 protein cause tumour cells to undergo apoptosis by preventing cell growth through a number of biological pathways;and(2)Exogenous p53 makes HCC susceptible to various anticancer drugs.This review describes the functions and primary mechanisms of p53 in pathological mechanism,chemoresistance and therapeutic mechanisms of HCC.展开更多
INTRODUCTIONHepatocellular carcinoma (HCC) is one of the mostcommon human malignancies worldwide[1,2], and isclosely associated with infection of HBV and HCVand contamination of aflatoxin B1[3-6]. Althoughthe molecula...INTRODUCTIONHepatocellular carcinoma (HCC) is one of the mostcommon human malignancies worldwide[1,2], and isclosely associated with infection of HBV and HCVand contamination of aflatoxin B1[3-6]. Althoughthe molecular mechanisms of hepatocarcinogenesisremain poorly understood, an increasing number ofgenetic abnormalities have been recognized[7-10],for example, the p16 gene[11,12] the p53gene[13-18], the E-cadherin gene[19], and the c-mycgene[20].展开更多
To observe the relationship between tumor suppressor gene p16 expression and ovarian cancer occurrence and development. Metbods: Using ABC immunohistochemistry method, we investigated the expression of p16 in 72 cases...To observe the relationship between tumor suppressor gene p16 expression and ovarian cancer occurrence and development. Metbods: Using ABC immunohistochemistry method, we investigated the expression of p16 in 72 cases of ovarian neoplasm. Results: The positive rates of p16 in malignant, benign, borderline tumors and normal ovarian tissue were 7. 89%, 60.00%, 66. 67% and 83. 33%, respectively (P<0.01). In the cases whose tumors were more malignant and poorly differentiated, and who relapsed and died, the positive stainings were not discovered. Conclusiou: p16 is well related with the occurrence and development of malignant ovarian tumor.展开更多
Colorectal cancer(CRC) is one of the most common malignancies with high prevalence and low 5-year survival.CRC is a heterogeneous disease with a complex,genetic and biochemical background.It is now generally accepted ...Colorectal cancer(CRC) is one of the most common malignancies with high prevalence and low 5-year survival.CRC is a heterogeneous disease with a complex,genetic and biochemical background.It is now generally accepted that a few important intracellular signaling pathways,including Wnt/β-catenin signaling,Ras signaling,and p53 signaling are frequently dysregulated in CRC.Patients with mutant p53 gene are often resistant to current therapies,conferring poor prognosis.Tumor suppressor p53 protein is a transcription factor inducing cell cycle arrest,senescence,and apoptosis under cellular stress.Emerging evidence from laboratories and clinical trials shows that some small molecule inhibitors exert anti-cancer effect via reactivation and restoration of p53 function.In this review,we summarize the p53 function and characterize its mutations in CRC.The involvement of p53 mutations in pathogenesis of CRC and their clinical impacts will be highlighted.Moreover,we also describe the current achievements of using p53 modulators to reactivate this pathway in CRC,which may have great potential as novel anti-cancer therapy.展开更多
gastric carcinomas were examined immunohistochemically with McAb to p53 protein in order to investigate the relationship between the expression of p53 protein and histological differentiation of gastric carcinoma, and...gastric carcinomas were examined immunohistochemically with McAb to p53 protein in order to investigate the relationship between the expression of p53 protein and histological differentiation of gastric carcinoma, and to approach the mechanism of infiltration and metastasis of gastric carcinoma. The results showed that nuclear expression of p53 protein was significantly related to tumor size, depth of invasion, lymph node and liver metastases; but not related to histological differentiation. It is suggested that the accumulation of p53 protein was increased with the progression of gastric carcinoma, and therefore the cancer clone with p53 gene mutation may play an important role in the development of tumor invasion and metastasis.展开更多
Multiplex Ligation-Dependent Probe Amplification (MLPA) was used to study the integrity of the chromosomes for two WIL2-derived lymphoblastoid cell lines (TK6 and WTK1) in the presence and absence of ionizing radiatio...Multiplex Ligation-Dependent Probe Amplification (MLPA) was used to study the integrity of the chromosomes for two WIL2-derived lymphoblastoid cell lines (TK6 and WTK1) in the presence and absence of ionizing radiation. WTK1 cells contain a p53 mutation, whereas the TK6 cell line has the native p53 tumor-suppressor gene. Each cell line was isolated pre- and post-irradiation (2 and 3 Gy) and analyzed by MLPA. Using probes that target specific regions on chromosomes associated with a distinct subset of microdeletions and microduplications either established or thought to be responsible for intellectual disability or developmental delay, we have demonstrated that WTK1 and TK6 are not impacted in the same way by irradiation. Instead, each cell line presents its own unique MLPA profile. The most notable differences are the appearance of nine unique probe signals only seen in WTK1 cells. These results are important in the study of how different cell lines can be affected in significantly different ways depending on the presence or absence of wild type p53.展开更多
文摘Objective: To explore the changes and significance of tumor suppressor gene p53 in primary hepatocellu-lar carcinoma (PHC ) with hepatitis B virus (HBV ) infection. Methods: Tumor tissues and surrounding nontumortissues of sixteen PHC cases were studied by Southern hybridization to detect the state of HBV-DNA in tissues, byimmunohistochemical staining to determine HBsAg, HBxAg and p53 protein, and by PCR directed sequencing toanalyse the point mutation of p53 gene exons 5 to 8. Results: Among the 16 cases. 13 cases were HBV-DNA posi-tive, 10 tumor cases and 13 nontumor tissues cases HBxAg positive, and 9 cases posltive for p53 protein. The se-quencing of p53 gene point mutation was found in 5 cases, only one of which was sited at codon 249 G to T. Con-clusion: The mutation of p53 gene codon 249 is infrequent in HBV related PHC,indicating the accumulation of p53protein in cells may be associated with expression of HBxAg. HBxAg binding to p53 protein and inactivation of p53function play important roles in the development of PHC.
文摘In the world,hepatocellular carcinoma(HCC)is among the top 10 most prevalent malignancies.HCC formation has indeed been linked to numerous etiological factors,including alcohol usage,hepatitis viruses and liver cirrhosis.Among the most prevalent defects in a wide range of tumours,notably HCC,is the silencing of the p53 tumour suppressor gene.The control of the cell cycle and the preservation of gene function are both critically important functions of p53.In order to pinpoint the core mechanisms of HCC and find more efficient treatments,molecular research employing HCC tissues has been the main focus.Stimulated p53 triggers necessary reactions that achieve cell cycle arrest,genetic stability,DNA repair and the elimination of DNA-damaged cells’responses to biological stressors(like oncogenes or DNA damage).To the contrary hand,the oncogene protein of the murine double minute 2(MDM2)is a significant biological inhibitor of p53.MDM2 causes p53 protein degradation,which in turn adversely controls p53 function.Despite carrying wt-p53,the majority of HCCs show abnormalities in the p53-expressed apoptotic pathway.High p53 in-vivo expression might have two clinical impacts on HCC:(1)Increased levels of exogenous p53 protein cause tumour cells to undergo apoptosis by preventing cell growth through a number of biological pathways;and(2)Exogenous p53 makes HCC susceptible to various anticancer drugs.This review describes the functions and primary mechanisms of p53 in pathological mechanism,chemoresistance and therapeutic mechanisms of HCC.
基金Project supported partly by the National Natural Science Foundation of China, No. 39870344
文摘INTRODUCTIONHepatocellular carcinoma (HCC) is one of the mostcommon human malignancies worldwide[1,2], and isclosely associated with infection of HBV and HCVand contamination of aflatoxin B1[3-6]. Althoughthe molecular mechanisms of hepatocarcinogenesisremain poorly understood, an increasing number ofgenetic abnormalities have been recognized[7-10],for example, the p16 gene[11,12] the p53gene[13-18], the E-cadherin gene[19], and the c-mycgene[20].
文摘To observe the relationship between tumor suppressor gene p16 expression and ovarian cancer occurrence and development. Metbods: Using ABC immunohistochemistry method, we investigated the expression of p16 in 72 cases of ovarian neoplasm. Results: The positive rates of p16 in malignant, benign, borderline tumors and normal ovarian tissue were 7. 89%, 60.00%, 66. 67% and 83. 33%, respectively (P<0.01). In the cases whose tumors were more malignant and poorly differentiated, and who relapsed and died, the positive stainings were not discovered. Conclusiou: p16 is well related with the occurrence and development of malignant ovarian tumor.
基金Supported by National Research Foundation Singapore and the Singapore Ministry of Education under its Research Centres of Excellence initiativeNMRC Clinician-Scientist IRG Grant CNIG11nov38(Zhou J)Chng WJ is also supported by NMRC Clinician Scientist Investigator award
文摘Colorectal cancer(CRC) is one of the most common malignancies with high prevalence and low 5-year survival.CRC is a heterogeneous disease with a complex,genetic and biochemical background.It is now generally accepted that a few important intracellular signaling pathways,including Wnt/β-catenin signaling,Ras signaling,and p53 signaling are frequently dysregulated in CRC.Patients with mutant p53 gene are often resistant to current therapies,conferring poor prognosis.Tumor suppressor p53 protein is a transcription factor inducing cell cycle arrest,senescence,and apoptosis under cellular stress.Emerging evidence from laboratories and clinical trials shows that some small molecule inhibitors exert anti-cancer effect via reactivation and restoration of p53 function.In this review,we summarize the p53 function and characterize its mutations in CRC.The involvement of p53 mutations in pathogenesis of CRC and their clinical impacts will be highlighted.Moreover,we also describe the current achievements of using p53 modulators to reactivate this pathway in CRC,which may have great potential as novel anti-cancer therapy.
文摘gastric carcinomas were examined immunohistochemically with McAb to p53 protein in order to investigate the relationship between the expression of p53 protein and histological differentiation of gastric carcinoma, and to approach the mechanism of infiltration and metastasis of gastric carcinoma. The results showed that nuclear expression of p53 protein was significantly related to tumor size, depth of invasion, lymph node and liver metastases; but not related to histological differentiation. It is suggested that the accumulation of p53 protein was increased with the progression of gastric carcinoma, and therefore the cancer clone with p53 gene mutation may play an important role in the development of tumor invasion and metastasis.
文摘Multiplex Ligation-Dependent Probe Amplification (MLPA) was used to study the integrity of the chromosomes for two WIL2-derived lymphoblastoid cell lines (TK6 and WTK1) in the presence and absence of ionizing radiation. WTK1 cells contain a p53 mutation, whereas the TK6 cell line has the native p53 tumor-suppressor gene. Each cell line was isolated pre- and post-irradiation (2 and 3 Gy) and analyzed by MLPA. Using probes that target specific regions on chromosomes associated with a distinct subset of microdeletions and microduplications either established or thought to be responsible for intellectual disability or developmental delay, we have demonstrated that WTK1 and TK6 are not impacted in the same way by irradiation. Instead, each cell line presents its own unique MLPA profile. The most notable differences are the appearance of nine unique probe signals only seen in WTK1 cells. These results are important in the study of how different cell lines can be affected in significantly different ways depending on the presence or absence of wild type p53.
