Gastric cancer is one of the most common malignancies and a leading cause of cancer mortality worldwide.The pathogenesis mechanisms of gastric cancer are still not fully clear.Inactivation of tumor suppressor genes an...Gastric cancer is one of the most common malignancies and a leading cause of cancer mortality worldwide.The pathogenesis mechanisms of gastric cancer are still not fully clear.Inactivation of tumor suppressor genes and activation of oncogenes caused by genetic and epigenetic alterations are known to play significant roles in carcinogenesis.Accumulating evidence has shown that epigenetic silencing of the tumor suppressor genes,particularly caused by hypermethylation of CpG islands in promoters,is critical to carcinogenesis and metastasis.Here,we review the recent progress in the study of methylations of tumor suppressor genes involved in the pathogenesis of gastric cancer.We also briefly describe the mechanisms that induce tumor suppressor gene methylation and the status of translating these molecular mechanisms into clinical applications.展开更多
Pancreatic cancer(PC) is a highly lethal disease and notoriously difficult to treat. Only a small proportion of PC patients are eligible for surgical resection, whilst conventional chemoradiotherapy only has a modest ...Pancreatic cancer(PC) is a highly lethal disease and notoriously difficult to treat. Only a small proportion of PC patients are eligible for surgical resection, whilst conventional chemoradiotherapy only has a modest effect with substantial toxicity. Gene therapy has become a new widely investigated therapeutic approach for PC.This article reviews the basic rationale, gene delivery methods, therapeutic targets and developments of laboratory research and clinical trials in gene therapy of PC by searching the literature published in English using the PubMed database and analyzing clinical trials registered on the Gene Therapy Clinical Trials Worldwide website(http://www. wiley.co.uk/genmed/ clinical). Viral vectors are main gene delivery tools in gene therapy of cancer, and especially, oncolytic virus shows brighter prospect due to its tumor-targeting property.Efficient therapeutic targets for gene therapy include tumor suppressor gene p53, mutant oncogene K-ras,anti-angiogenesis gene VEGFR, suicide gene HSK-TK,cytosine deaminase and cytochrome p450, multiple cytokine genes and so on. Combining different targets or combination strategies with traditional chemoradiother-apy may be a more effective approach to improve the efficacy of cancer gene therapy. Cancer gene therapy is not yet applied in clinical practice, but basic and clinical studies have demonstrated its safety and clinical benefits. Gene therapy will be a new and promising field for the treatment of PC.展开更多
Objective: This study was designed to investigate promoter methylation status and protein expression of p14^ARF gene in non-small cell lung cancer, and value the role of p14^ARF promoter methylation in carcinogenesis...Objective: This study was designed to investigate promoter methylation status and protein expression of p14^ARF gene in non-small cell lung cancer, and value the role of p14^ARF promoter methylation in carcinogenesis of non-small cell lung cancer. Methods: Promoter methylation status and protein expression of p14^ARF gene in 40 cases of non-small cell lung cancer were analyzed by methylation specific polymerase china reaction (MSP), restriction enzyme-related polymerase chain reaction (RE-PCR) and immunohistochemistry (IHC). Results: The positive rates of p14^ARF promoter methylation in tumor tissues and normal tissues adjacent to cancer were 17.5% (7/40) and 2.5% (1/40) respectively. There were statistically significant differences between them, P〈0.05. The results of RE-PCR were consistent with that of MSP. The expression rate of p14^ARF protein in tumor tissues was significantly lower than that in normal tissues adjacent to cancer, p〈0.01. Promoter methylation status and protein expression of p14^ARF gene in non-small cell lung cancer showed significantly an inverse correlation (r=-0.56, P〈0.01), and both of them did not relate statistically with the clinicopathologic characteristics of patients such as histological classification, clinical stage, differentiation grade and lymph node involvement. Conclusion: Promoter methylation is a crucial mechanism of inactivation of p14^ARF gene. Promoter methylation of p14^ARF gene might he involved in carcinogenesis of non-small cell lung cancer, and is an early event in development process of non-small cell lung cancer. It might be used as a new target in gene treatments in the future.展开更多
A number of tumor suppressor and tumor-related genes exhibit promoter hypermethylation with resultant gene silencing in human cancers.The frequencies of methylation differ among genes and genomic regions within CpG is...A number of tumor suppressor and tumor-related genes exhibit promoter hypermethylation with resultant gene silencing in human cancers.The frequencies of methylation differ among genes and genomic regions within CpG islands in different tissue types.Hypermethylation initially occurs at the edge of CpG islands and spreads to the transcription start site before ultimately shutting down gene expression.When the degree of methylation was quantitatively evaluated in neoplastic and non-neoplastic gastric epithelia using DNA microarray analysis,highlevel methylation around the transcription start site appeared to be a tumor-specific phenomenon,although multiple tumor suppressor genes became increasingly methylated with patient age in non-neoplastic gastric epithelia.Quantitative analysis of DNA methylation is a promising method for both cancer diagnosis and risk assessment.展开更多
AIM: To investigate a novel therapeutic strategy to target and suppress c-myc in human cancers using far up stream element (FUSE)-binding protein-interacting repressor (FIR).
objective: To investigate the effects of multiple tumor suppressor 1 on the proliferation of ovarian cancer cell lines. Methods: Growth characteristics of HO-8910 (without p16 gene expression ), 8910-p16 (trans fected...objective: To investigate the effects of multiple tumor suppressor 1 on the proliferation of ovarian cancer cell lines. Methods: Growth characteristics of HO-8910 (without p16 gene expression ), 8910-p16 (trans fected with p16 gene) and 8910-pcDNA3 (transfected with the vector pcDNA3) cells were studied by comparison of the cell growth curves. DNA synthesis was also compared among the 3 kinds of cells. Results: After trans fected with p16 gene, the 8910-p16 cells were markedly inhibited in both the proliferation and DNA synthesis. There was no significant difference between the 8910-pcDNA3 cells and the HO-8910 cells. Conclusion: Multiple tumor suppressor 1 can inhibit the proliferation and DNA synthesis of human ovarian cancer HO-8910 cells.展开更多
Gastric cancer (GC) is a major cause of cancer mortality. GC studies that aim to identify relevant oncogenes and tumor suppressor genes (TSGs) are essential for devising effective new therapies. A decade ago, RUNX3, a...Gastric cancer (GC) is a major cause of cancer mortality. GC studies that aim to identify relevant oncogenes and tumor suppressor genes (TSGs) are essential for devising effective new therapies. A decade ago, RUNX3, a gene that resides on human chromosome 1p36.1, was claimed to be a major TSG in GC. Since then, hundreds of studies involving thousands of GC patients have attempted to verify and extend the RUNX3 TSG paradigm. However, RUNX3 is not recognized as TSG and not listed in the “Cancer Gene Census” website. To be a TSG that protects normal cells against malignancy, the gene must be expressed in the normal tissue from which the cancer arose and its loss or inactivation should contribute to cancer development. This review summarizes compelling body of evidence challenging the RUNX3-TSG paradigm. Studies show unequivocally that RUNX3 is not expressed in normal gastric epithelium and that it fails to fulfill all other premises of a TSG. RUNX3 mutations and 1p36 deletions are not frequent in GC and RUNX3 is not associated with familial GC or with increased risk of GC. Accordingly, Runx3-/- mice do not develop tumors. RUNX3 promoter methylation, which has been reported to be a frequent event in GC, is not relevant to its alleged TSG function, since the gene is already silent in normal gastric epithelium. In sharp contrast, overexpression of RUNX3 was found in several types of human cancers, including GC, and the 1p36.1 region is amplified in B-cell lymphoma. Thus, it is possible that RUNX3 actually promotes cancer development rather than being a TSG. The true targets for GC therapy are discussed below. Those are genes frequently lost or amplified in GC and are well known for their tumor suppressive or oncogenic activity, respectively.展开更多
Breast cancer is a complex disease driven by multiple factors including both genetic and epigenetic alterations.Recent studies revealed that abnormal gene expression induced by epigenetic changes,including aberrant pr...Breast cancer is a complex disease driven by multiple factors including both genetic and epigenetic alterations.Recent studies revealed that abnormal gene expression induced by epigenetic changes,including aberrant promoter methylation and histone modification,plays a critical role in human breast carcinogenesis.Silencing of tumor suppressor genes(TSGs) by promoter CpG methylation facilitates cells growth and survival advantages and further results in tumor initiation and progression,thus directly contributing to breast tumorigenesis.Usually,aberrant promoter methylation of TSGs,which can be reversed by pharmacological reagents,occurs at the early stage of tumorigenesis and therefore may serve as a potential tumor marker for early diagnosis and therapeutic targeting of breast cancer.In this review,we summarize the epigenetic changes of multiple TSGs involved in breast pathogenesis and their potential clinical applications as tumor markers for early detection and treatment of breast cancer.展开更多
Gallbladder cancer(GBC) is infrequent but most lethal biliary tract malignancy characterized by an advanced stage diagnosis and poor survival rates attributed to absence of specific symptoms and effective treatment op...Gallbladder cancer(GBC) is infrequent but most lethal biliary tract malignancy characterized by an advanced stage diagnosis and poor survival rates attributed to absence of specific symptoms and effective treatment options. These necessitate development of early prognostic/predictive markers and novel therapeutic interventions. Micro RNAs(mi RNAs) are small, noncoding RNA molecules that play a key role in tumor biology by functioning like tumor suppressor- or oncogenes and their aberrant expression are associated with the pathogenesis of several neoplasms with overwhelming clinical implications. Since mi RNA signature is tissue specific, here, we focused on current data concerning the mi RNAs abberations in GBC pathogenesis. In GBC, mi RNAs with tumor suppressor activity(mi R-135-5p, mi R-335, mi R-34 a, mi R-26 a, mi R-146b-5p, Mir-218-5p, mi R-1, mi R-145, mir-130a) were found downregulated, while those with oncogenic property(mi R-20 a, mi R-182, mir-155) were upregulated. The expression profile of mi RNAs was significantly associated with GBC prognosis and prediction, and forced over-expression/ inhibition of these mi RNAs was shown to affect tumor growth and development. Further, differential expression of mi RNAs in the blood samples of GBC patients suggest mi RNAs as promising noninvasive biomarker. Thus, mi RNAs represent potential candidate for GBC management, though many hurdles need to be overcome before mi RNAs therapy can be clinically applied to GBC prevention and treatment.展开更多
目的探索乳腺癌/卵巢癌易感基因1相关蛋白1(breast/ovarian cancer susceptibility gene 1 associated protein 1,BAP1)对人源恶性胶质瘤发生、发展的作用与BAP1作为恶性胶质瘤临床诊断标志物的可行性。方法基于基因表达综合数据库(gene...目的探索乳腺癌/卵巢癌易感基因1相关蛋白1(breast/ovarian cancer susceptibility gene 1 associated protein 1,BAP1)对人源恶性胶质瘤发生、发展的作用与BAP1作为恶性胶质瘤临床诊断标志物的可行性。方法基于基因表达综合数据库(gene expression omnibus,GEO)的子数据集GSE4290,GSE90598,分析BAP1在正常组织及胶质瘤组织中的差异性表达情况;受试者工作特征(receiver operating characteristic,ROC)曲线分析BAP1对恶性胶质瘤的早期诊断价值;选取自主收集的非配对28例恶性胶质瘤患者的原发灶组织、5例颅脑外伤患者内减压术切除的非瘤脑组织,采用实时荧光定量PCR(quantitative real-time polymerase chain reaction,qRT-PCR)检测BAP1的表达水平;利用靶向BAP1的特异性小干扰RNAs(small interfering RNAs,siRNAs)瞬时转染U251细胞系,进一步检测其干涉效率;基于流式细胞仪分析BAP1下调的U251细胞系,其细胞周期、凋亡的变化情况。结果生物信息学结果显示,BAP1在恶性胶质瘤组织中的表达水平均低于正常脑组织(GSE4290:1209±18.49 vs 1476±53.90;GSE90598:5.19±0.10 vs 5.65±0.21),差异具有统计学意义(t=5.115,2.267,均P<0.05)。ROC曲线显示,BAP1可高效区分恶性胶质瘤组织与正常脑组织(GSE4290:AUC=0.78;GSE90598:AUC=0.75,均P<0.05)。临床标本结果显示,BAP1在恶性胶质瘤原发灶组织中的表达水平显著低于非瘤脑组织(0.27±0.04 vs 1.06±0.07),差异具有统计学意义(t=10.22,P<0.001)。在U251细胞系中下调BAP1的表达,其细胞周期中S期细胞比例明显增多,由17.59%分别增至27.21%(siBAP1-1)和25.79%(siBAP1-2),差异具有统计学意义(t=6.576,6.642,均P<0.01),而细胞凋亡水平则有所下降,由10.17%分别降至2.70%(siBAP-1)和3.00%(siBAP-2),差异具有统计学意义(t=10.31,9.428,均P<0.01)。结论组蛋白H2A去泛素化酶BAP1能够通过抑制恶性胶质瘤细胞周期快速进展并促进其凋亡,进而发挥肿瘤抑癌基因的功能,可作为潜在的恶性胶质瘤临床诊断标志物。展开更多
Metastatic pancreatic cancer(MPC) is one of the most aggressive malignancies, known to be chemo-resistant and have been recently considered resistant to some targeted therapies(TT). Erlotinib combined to gemcitabine i...Metastatic pancreatic cancer(MPC) is one of the most aggressive malignancies, known to be chemo-resistant and have been recently considered resistant to some targeted therapies(TT). Erlotinib combined to gemcitabine is the only targeted therapy that showed an overall survival benefit in MPC. New targets and therapeutic approaches, based on new-TT, are actually being evaluated in MPC going from immunotherapy, epigenetics, tumor suppressor gene and oncogenes to stromal matrix regulators. We aim in this paper to present the major causes rendering MPC an untargetable malignancy and to focus on the new therapeutic modalities based on TT in MPC.展开更多
Persistent infection wit h high-risk types of human papillomavirus(HPV) is known to cause cervical cancer;however,additional genetic and epigenetic alterations are required for progression from precancerous disease to...Persistent infection wit h high-risk types of human papillomavirus(HPV) is known to cause cervical cancer;however,additional genetic and epigenetic alterations are required for progression from precancerous disease to invasive cancer.DNA methylation is an early and frequent molecular alteration in cervical carcinogenesis.In this review,we summarize DNA methylation within the HPV genome and human genome and identify its clinical implications.Methylation of the HPV long control region(LCR) and L1 gene is common during cervical carcinogenesis and increases with the severity of the cervical neoplasm.The L1 gene of HPV16 and HPV18 is consistently hypermethylated in invasive cervical cancers and can potentially be used as a clinical marker of cancer progression.Moreover,promoters of tumor suppressor genes(TSGs) involved in many cellular pathways are methylated in cervical precursors and invasive cancers.Some are associated with squamous cell carcinomas,and others are associated with adenocarcinomas.Identification of methylated TSGs in Pap smear could be an adjuvant test in cervical cancer screening for triage of women with high-risk HPV,atypical squamous cells of undetermined significance,or low grade squamous intraepithelial lesion(LSIL).However,consistent panels must be validated for this approach to be translated to the clinic.Furthermore,reversion of methylated TSGs using demethylating drugs may be an alternative anticancer treatment,but demethylating drugs without toxic carcinogenic and mutagenic properties must be identified and validated.展开更多
This study examined the expression of cell adhesion molecule 1 (CADM1) in pancreatic cancer and the possible mechanism. The expression of CADM 1 was detected by immunohistochemistry in tissues of pancreatic cancer, ...This study examined the expression of cell adhesion molecule 1 (CADM1) in pancreatic cancer and the possible mechanism. The expression of CADM 1 was detected by immunohistochemistry in tissues of pancreatic cancer, pancreatitis, and normal pancreas. The plasmid pcDNA3.1-Hy- gro(+)/CADM1 was transfected into PANC-1 cells (a pancreatic cancer cell line). The expression of CADM1 in the transfected cells was determined by RT-PCR and Western blotting. Cell growth was measured by the MTT method and cell apoptosis by flow cytometry. The results showed that CADM1 was weakly expressed in tissues of pancreatic cancer in contrast to its high expression in normal pancreatic and pancreatitis tissues. The expression level of CADM in pancreatic caner was intensely correlated with the differentiation degree, lymph node metastasis and TNM stages. The growth of CADMl-transfected PANC-1 cells was significantly suppressed in vitro by a G1 cell cycle arrest and apoptosis occurrence. It was concluded that re-expression of CADM1 inhibits the growth of pancreatic cancer cells and induces their apoptosis in vitro. As a tumor suppressor gene, CADM1 plays an important role in the occurrence, progression and metastasis of pancreatic cancer.展开更多
基金supported by grants from National Natural Science Foundation of China(No.30770920 and 81071651)Zhejiang Provincial Natural Science Foundation of China(No.R2100213,2009C33142,Z2090056 and WKJ2009-2-028)973 Project(No.2010CB834300)
文摘Gastric cancer is one of the most common malignancies and a leading cause of cancer mortality worldwide.The pathogenesis mechanisms of gastric cancer are still not fully clear.Inactivation of tumor suppressor genes and activation of oncogenes caused by genetic and epigenetic alterations are known to play significant roles in carcinogenesis.Accumulating evidence has shown that epigenetic silencing of the tumor suppressor genes,particularly caused by hypermethylation of CpG islands in promoters,is critical to carcinogenesis and metastasis.Here,we review the recent progress in the study of methylations of tumor suppressor genes involved in the pathogenesis of gastric cancer.We also briefly describe the mechanisms that induce tumor suppressor gene methylation and the status of translating these molecular mechanisms into clinical applications.
文摘Pancreatic cancer(PC) is a highly lethal disease and notoriously difficult to treat. Only a small proportion of PC patients are eligible for surgical resection, whilst conventional chemoradiotherapy only has a modest effect with substantial toxicity. Gene therapy has become a new widely investigated therapeutic approach for PC.This article reviews the basic rationale, gene delivery methods, therapeutic targets and developments of laboratory research and clinical trials in gene therapy of PC by searching the literature published in English using the PubMed database and analyzing clinical trials registered on the Gene Therapy Clinical Trials Worldwide website(http://www. wiley.co.uk/genmed/ clinical). Viral vectors are main gene delivery tools in gene therapy of cancer, and especially, oncolytic virus shows brighter prospect due to its tumor-targeting property.Efficient therapeutic targets for gene therapy include tumor suppressor gene p53, mutant oncogene K-ras,anti-angiogenesis gene VEGFR, suicide gene HSK-TK,cytosine deaminase and cytochrome p450, multiple cytokine genes and so on. Combining different targets or combination strategies with traditional chemoradiother-apy may be a more effective approach to improve the efficacy of cancer gene therapy. Cancer gene therapy is not yet applied in clinical practice, but basic and clinical studies have demonstrated its safety and clinical benefits. Gene therapy will be a new and promising field for the treatment of PC.
文摘Objective: This study was designed to investigate promoter methylation status and protein expression of p14^ARF gene in non-small cell lung cancer, and value the role of p14^ARF promoter methylation in carcinogenesis of non-small cell lung cancer. Methods: Promoter methylation status and protein expression of p14^ARF gene in 40 cases of non-small cell lung cancer were analyzed by methylation specific polymerase china reaction (MSP), restriction enzyme-related polymerase chain reaction (RE-PCR) and immunohistochemistry (IHC). Results: The positive rates of p14^ARF promoter methylation in tumor tissues and normal tissues adjacent to cancer were 17.5% (7/40) and 2.5% (1/40) respectively. There were statistically significant differences between them, P〈0.05. The results of RE-PCR were consistent with that of MSP. The expression rate of p14^ARF protein in tumor tissues was significantly lower than that in normal tissues adjacent to cancer, p〈0.01. Promoter methylation status and protein expression of p14^ARF gene in non-small cell lung cancer showed significantly an inverse correlation (r=-0.56, P〈0.01), and both of them did not relate statistically with the clinicopathologic characteristics of patients such as histological classification, clinical stage, differentiation grade and lymph node involvement. Conclusion: Promoter methylation is a crucial mechanism of inactivation of p14^ARF gene. Promoter methylation of p14^ARF gene might he involved in carcinogenesis of non-small cell lung cancer, and is an early event in development process of non-small cell lung cancer. It might be used as a new target in gene treatments in the future.
文摘A number of tumor suppressor and tumor-related genes exhibit promoter hypermethylation with resultant gene silencing in human cancers.The frequencies of methylation differ among genes and genomic regions within CpG islands in different tissue types.Hypermethylation initially occurs at the edge of CpG islands and spreads to the transcription start site before ultimately shutting down gene expression.When the degree of methylation was quantitatively evaluated in neoplastic and non-neoplastic gastric epithelia using DNA microarray analysis,highlevel methylation around the transcription start site appeared to be a tumor-specific phenomenon,although multiple tumor suppressor genes became increasingly methylated with patient age in non-neoplastic gastric epithelia.Quantitative analysis of DNA methylation is a promising method for both cancer diagnosis and risk assessment.
基金Supported by In part by the 21st Century COE(Center Of Ex-cellence)Programs to Dr.Takenori Ochiaiby a Grant-in-Aid 18591453 to K.M from the Ministry of Education,Science,Sports and Culture of Japan
文摘AIM: To investigate a novel therapeutic strategy to target and suppress c-myc in human cancers using far up stream element (FUSE)-binding protein-interacting repressor (FIR).
文摘objective: To investigate the effects of multiple tumor suppressor 1 on the proliferation of ovarian cancer cell lines. Methods: Growth characteristics of HO-8910 (without p16 gene expression ), 8910-p16 (trans fected with p16 gene) and 8910-pcDNA3 (transfected with the vector pcDNA3) cells were studied by comparison of the cell growth curves. DNA synthesis was also compared among the 3 kinds of cells. Results: After trans fected with p16 gene, the 8910-p16 cells were markedly inhibited in both the proliferation and DNA synthesis. There was no significant difference between the 8910-pcDNA3 cells and the HO-8910 cells. Conclusion: Multiple tumor suppressor 1 can inhibit the proliferation and DNA synthesis of human ovarian cancer HO-8910 cells.
文摘Gastric cancer (GC) is a major cause of cancer mortality. GC studies that aim to identify relevant oncogenes and tumor suppressor genes (TSGs) are essential for devising effective new therapies. A decade ago, RUNX3, a gene that resides on human chromosome 1p36.1, was claimed to be a major TSG in GC. Since then, hundreds of studies involving thousands of GC patients have attempted to verify and extend the RUNX3 TSG paradigm. However, RUNX3 is not recognized as TSG and not listed in the “Cancer Gene Census” website. To be a TSG that protects normal cells against malignancy, the gene must be expressed in the normal tissue from which the cancer arose and its loss or inactivation should contribute to cancer development. This review summarizes compelling body of evidence challenging the RUNX3-TSG paradigm. Studies show unequivocally that RUNX3 is not expressed in normal gastric epithelium and that it fails to fulfill all other premises of a TSG. RUNX3 mutations and 1p36 deletions are not frequent in GC and RUNX3 is not associated with familial GC or with increased risk of GC. Accordingly, Runx3-/- mice do not develop tumors. RUNX3 promoter methylation, which has been reported to be a frequent event in GC, is not relevant to its alleged TSG function, since the gene is already silent in normal gastric epithelium. In sharp contrast, overexpression of RUNX3 was found in several types of human cancers, including GC, and the 1p36.1 region is amplified in B-cell lymphoma. Thus, it is possible that RUNX3 actually promotes cancer development rather than being a TSG. The true targets for GC therapy are discussed below. Those are genes frequently lost or amplified in GC and are well known for their tumor suppressive or oncogenic activity, respectively.
基金supported by grants from the National Natural Science Foundation of China(NSFC)(No.#81072148,#81071634and#30928012)Natural Science Foundation of Chongqing(No.2010BB5101)Shenzhen Science Fund for Distinguished Young Scholars(No.JC201005270328A)
文摘Breast cancer is a complex disease driven by multiple factors including both genetic and epigenetic alterations.Recent studies revealed that abnormal gene expression induced by epigenetic changes,including aberrant promoter methylation and histone modification,plays a critical role in human breast carcinogenesis.Silencing of tumor suppressor genes(TSGs) by promoter CpG methylation facilitates cells growth and survival advantages and further results in tumor initiation and progression,thus directly contributing to breast tumorigenesis.Usually,aberrant promoter methylation of TSGs,which can be reversed by pharmacological reagents,occurs at the early stage of tumorigenesis and therefore may serve as a potential tumor marker for early diagnosis and therapeutic targeting of breast cancer.In this review,we summarize the epigenetic changes of multiple TSGs involved in breast pathogenesis and their potential clinical applications as tumor markers for early detection and treatment of breast cancer.
文摘Gallbladder cancer(GBC) is infrequent but most lethal biliary tract malignancy characterized by an advanced stage diagnosis and poor survival rates attributed to absence of specific symptoms and effective treatment options. These necessitate development of early prognostic/predictive markers and novel therapeutic interventions. Micro RNAs(mi RNAs) are small, noncoding RNA molecules that play a key role in tumor biology by functioning like tumor suppressor- or oncogenes and their aberrant expression are associated with the pathogenesis of several neoplasms with overwhelming clinical implications. Since mi RNA signature is tissue specific, here, we focused on current data concerning the mi RNAs abberations in GBC pathogenesis. In GBC, mi RNAs with tumor suppressor activity(mi R-135-5p, mi R-335, mi R-34 a, mi R-26 a, mi R-146b-5p, Mir-218-5p, mi R-1, mi R-145, mir-130a) were found downregulated, while those with oncogenic property(mi R-20 a, mi R-182, mir-155) were upregulated. The expression profile of mi RNAs was significantly associated with GBC prognosis and prediction, and forced over-expression/ inhibition of these mi RNAs was shown to affect tumor growth and development. Further, differential expression of mi RNAs in the blood samples of GBC patients suggest mi RNAs as promising noninvasive biomarker. Thus, mi RNAs represent potential candidate for GBC management, though many hurdles need to be overcome before mi RNAs therapy can be clinically applied to GBC prevention and treatment.
文摘目的探索乳腺癌/卵巢癌易感基因1相关蛋白1(breast/ovarian cancer susceptibility gene 1 associated protein 1,BAP1)对人源恶性胶质瘤发生、发展的作用与BAP1作为恶性胶质瘤临床诊断标志物的可行性。方法基于基因表达综合数据库(gene expression omnibus,GEO)的子数据集GSE4290,GSE90598,分析BAP1在正常组织及胶质瘤组织中的差异性表达情况;受试者工作特征(receiver operating characteristic,ROC)曲线分析BAP1对恶性胶质瘤的早期诊断价值;选取自主收集的非配对28例恶性胶质瘤患者的原发灶组织、5例颅脑外伤患者内减压术切除的非瘤脑组织,采用实时荧光定量PCR(quantitative real-time polymerase chain reaction,qRT-PCR)检测BAP1的表达水平;利用靶向BAP1的特异性小干扰RNAs(small interfering RNAs,siRNAs)瞬时转染U251细胞系,进一步检测其干涉效率;基于流式细胞仪分析BAP1下调的U251细胞系,其细胞周期、凋亡的变化情况。结果生物信息学结果显示,BAP1在恶性胶质瘤组织中的表达水平均低于正常脑组织(GSE4290:1209±18.49 vs 1476±53.90;GSE90598:5.19±0.10 vs 5.65±0.21),差异具有统计学意义(t=5.115,2.267,均P<0.05)。ROC曲线显示,BAP1可高效区分恶性胶质瘤组织与正常脑组织(GSE4290:AUC=0.78;GSE90598:AUC=0.75,均P<0.05)。临床标本结果显示,BAP1在恶性胶质瘤原发灶组织中的表达水平显著低于非瘤脑组织(0.27±0.04 vs 1.06±0.07),差异具有统计学意义(t=10.22,P<0.001)。在U251细胞系中下调BAP1的表达,其细胞周期中S期细胞比例明显增多,由17.59%分别增至27.21%(siBAP1-1)和25.79%(siBAP1-2),差异具有统计学意义(t=6.576,6.642,均P<0.01),而细胞凋亡水平则有所下降,由10.17%分别降至2.70%(siBAP-1)和3.00%(siBAP-2),差异具有统计学意义(t=10.31,9.428,均P<0.01)。结论组蛋白H2A去泛素化酶BAP1能够通过抑制恶性胶质瘤细胞周期快速进展并促进其凋亡,进而发挥肿瘤抑癌基因的功能,可作为潜在的恶性胶质瘤临床诊断标志物。
文摘Metastatic pancreatic cancer(MPC) is one of the most aggressive malignancies, known to be chemo-resistant and have been recently considered resistant to some targeted therapies(TT). Erlotinib combined to gemcitabine is the only targeted therapy that showed an overall survival benefit in MPC. New targets and therapeutic approaches, based on new-TT, are actually being evaluated in MPC going from immunotherapy, epigenetics, tumor suppressor gene and oncogenes to stromal matrix regulators. We aim in this paper to present the major causes rendering MPC an untargetable malignancy and to focus on the new therapeutic modalities based on TT in MPC.
文摘Persistent infection wit h high-risk types of human papillomavirus(HPV) is known to cause cervical cancer;however,additional genetic and epigenetic alterations are required for progression from precancerous disease to invasive cancer.DNA methylation is an early and frequent molecular alteration in cervical carcinogenesis.In this review,we summarize DNA methylation within the HPV genome and human genome and identify its clinical implications.Methylation of the HPV long control region(LCR) and L1 gene is common during cervical carcinogenesis and increases with the severity of the cervical neoplasm.The L1 gene of HPV16 and HPV18 is consistently hypermethylated in invasive cervical cancers and can potentially be used as a clinical marker of cancer progression.Moreover,promoters of tumor suppressor genes(TSGs) involved in many cellular pathways are methylated in cervical precursors and invasive cancers.Some are associated with squamous cell carcinomas,and others are associated with adenocarcinomas.Identification of methylated TSGs in Pap smear could be an adjuvant test in cervical cancer screening for triage of women with high-risk HPV,atypical squamous cells of undetermined significance,or low grade squamous intraepithelial lesion(LSIL).However,consistent panels must be validated for this approach to be translated to the clinic.Furthermore,reversion of methylated TSGs using demethylating drugs may be an alternative anticancer treatment,but demethylating drugs without toxic carcinogenic and mutagenic properties must be identified and validated.
文摘This study examined the expression of cell adhesion molecule 1 (CADM1) in pancreatic cancer and the possible mechanism. The expression of CADM 1 was detected by immunohistochemistry in tissues of pancreatic cancer, pancreatitis, and normal pancreas. The plasmid pcDNA3.1-Hy- gro(+)/CADM1 was transfected into PANC-1 cells (a pancreatic cancer cell line). The expression of CADM1 in the transfected cells was determined by RT-PCR and Western blotting. Cell growth was measured by the MTT method and cell apoptosis by flow cytometry. The results showed that CADM1 was weakly expressed in tissues of pancreatic cancer in contrast to its high expression in normal pancreatic and pancreatitis tissues. The expression level of CADM in pancreatic caner was intensely correlated with the differentiation degree, lymph node metastasis and TNM stages. The growth of CADMl-transfected PANC-1 cells was significantly suppressed in vitro by a G1 cell cycle arrest and apoptosis occurrence. It was concluded that re-expression of CADM1 inhibits the growth of pancreatic cancer cells and induces their apoptosis in vitro. As a tumor suppressor gene, CADM1 plays an important role in the occurrence, progression and metastasis of pancreatic cancer.