Objective YAP1 plays a dual role as an oncogene and tumor suppressor gene in several tumors;differentiating between these roles may depend on the YAP1 phosphorylation pattern.The specific function of YAP1 in B cell ac...Objective YAP1 plays a dual role as an oncogene and tumor suppressor gene in several tumors;differentiating between these roles may depend on the YAP1 phosphorylation pattern.The specific function of YAP1 in B cell acute lymphoblastic leukemia(B-ALL),however,is currently unclear.Thus,in the present study,the role of YAP1 in B-ALL was investigated using relevant cell lines and patient datasets.Methods The effects of shRNA-mediated knockdown on YAP1 and LATS1 levels in the NALM6 and MOLT-4 cell lines were examined using Western blotting,quantitative real-time polymerase chain reaction,flow cytometry,immunostaining,and nude mouse subcutaneous tumorigenesis experiments.Gene expression levels of Hippo pathway-related molecules before and after verteporfin(VP)treatment were compared using RNA-Seq to identify significant Hippo pathway-related genes in NALM6 cells.Results Patients with ALL showing high YAP1 expression and low YAP1-Ser127 phosphorylation levels had worse prognoses than those with low YAP1 protein expression and high YAP1-Ser127 phosphorylation levels.YAP1-Ser127 phosphorylation levels were lower in NALM6 cells than in MOLT-4 and control cells;YAP1 was distributed in the nuclei in NALM6 cells.Knockdown of YAP1 inhibited MOLT-4 and NALM6 cell proliferation and arrested the NALM6 cell cycle in the G0/G1 phase.Before and after VP treatment,the expression of the upstream gene LATS1 was upregulated;its overexpression promoted YAP1-Ser127 phosphorylation.Further,YAP1 was distributed in the plasma.Conclusion LATS1 may downregulate YAP1-Ser127 phosphorylation and maintain B-ALL cell function;thus,VP,which targets this axis,may serve as a new therapeutic method for improving the outcomes for B-ALL patients.展开更多
Trans-acting factors controlling mRNA fate are critical for the post-transcriptional regulation of inflammation-related genes, as well as for oncogene and tumor suppressor expression in human cancers. Among them, a gr...Trans-acting factors controlling mRNA fate are critical for the post-transcriptional regulation of inflammation-related genes, as well as for oncogene and tumor suppressor expression in human cancers. Among them, a group of RNA-binding proteins called "Adenylate-Uridylate-rich elements binding proteins"(AUBPs)control mRNA stability or translation through their binding to AU-rich elements enriched in the 3'UTRs of inflammation-and cancer-associated mRNA transcripts. AUBPs play a central role in the recruitment of target mRNAs into small cytoplasmic foci called Processing-bodies and stress granules(also known as P-body/SG). Alterations in the expression and activities of AUBPs and Pbody/SG assembly have been observed to occur with colorectal cancer(CRC)progression, indicating the significant role AUBP-dependent post-transcriptional regulation plays in controlling gene expression during CRC tumorigenesis.Accordingly, these alterations contribute to the pathological expression of many early-response genes involved in prostaglandin biosynthesis and inflammation,along with key oncogenic pathways. In this review, we summarize the current role of these proteins in CRC development. CRC remains a major cause of cancer mortality worldwide and, therefore, targeting these AUBPs to restore efficient post-transcriptional regulation of gene expression may represent an appealing therapeutic strategy.展开更多
Pterygium is a common ocular surface disease induced by a variety of factors. The exact pathogenesis of pterygium remains unclear. Numbers of genes and proteins are discovered in pterygium and they function differentl...Pterygium is a common ocular surface disease induced by a variety of factors. The exact pathogenesis of pterygium remains unclear. Numbers of genes and proteins are discovered in pterygium and they function differently in the occurrence and development of this disease. We searched the Web of Science and PubMed throughout history for literatures about the subject. The keywords we used contain pterygium, gene, protein, angiogenesis, fibrosis, proliferation, inflammation, pathogenesis and therapy. In this review, we summarize the aberrant expression of a range of genes and proteins in pterygium compared with normal conjunctiva or cornea, including growth factors, matrix metalloproteinases and tissue inhibitors of mefalloproteinases, interleukins, tumor suppressor genes, proliferation related proteins, apoptosis related proteins, cell adhesion molecules, extracellular matrix proteins, heat shock proteins and tight junction proteins. We illustrate their possible mechanisms in the pathogenesis of pterygium as well as the related intervention based on them for pterygium therapy.展开更多
Insulin-like growth factor binding-protein-7 (IGFBP7) was obtained from our previous colonic adenocarcinoma (CRC) and normal mucosa suppression subtraction hybridization (SSH) cDNA libraries. By RT-PCR and immunohisto...Insulin-like growth factor binding-protein-7 (IGFBP7) was obtained from our previous colonic adenocarcinoma (CRC) and normal mucosa suppression subtraction hybridization (SSH) cDNA libraries. By RT-PCR and immunohistochemistry, we found that IGFBP7 was overexpressed in CRC tissue compared to normal tissue. However, our in vitro experiments performed in 10 CRC cell lines showed that IGFBP7 expressed only in SW480 and Caco2 cell lines, which implied an underlying reversible regulatory mechanism. Using methylation-specific PCR (MSP) and bisulfite sodium PCR (BSP), we found that its expression was associated with DNA hypomethylation of exon1. This was further supported by the in vitro study which showed restored IGFBP7 expression after demethylation agent 5-aza-2’-deoxycytidine treatment. Correlation analysis between IGFBP7 expression and prognosis indicated that overexpression of IGFBP7 in CRC tissue correlated with favourable survival. Investigation of the func-tional role of IGFBP7 through transfection studies showed that IGFBP7 protein could inhibit growth rate, decrease colony for-mation activity, and induce apoptosis in RKO and SW620 cells, suggesting it a potential tumor suppressor protein in colorectal carcinogenesis. In conclusion, our study clearly demonstrated that IGFBP7 plays a potential tumor suppressor role against colo-rectal carcinogenesis and its expression is associated with DNA hypomethylation of exon 1.展开更多
INTRODUCTIONIn 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 a...INTRODUCTIONIn 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 .展开更多
The events of cell death and the expression of nuclear matrix protein (NMP) have been investigated in a promyelocytic leukemic cell line HL-60 induced with etoposide. By means of TUNEL assay, the nuclei displayed a ch...The events of cell death and the expression of nuclear matrix protein (NMP) have been investigated in a promyelocytic leukemic cell line HL-60 induced with etoposide. By means of TUNEL assay, the nuclei displayed a characteristic morphology change, and the amount of apoptotic cells increased early and reached maximun about 39% after treatment with etoposide for 2 h. Nucleosomal DNA fragmentation was observed after treatment for 4 h. The morphological change of HL-60 cells, thus, occurred earlier than the appearance of DNA ladder. Total nuclear matrix proteins were analyzed by 2-dimensional gel electrophoresis. Differential expression of 59 nuclear matrix proteins was found in 4 h etoposide treated cells. Western blotting was then performed on three nuclear matrix acssociated proteins, PML, HSC70 and NuMA. The expression of the suppressor PML protein and heat shock protein HSC70 were significantly upregulated after etoposide treatment, while NuMA, a nuclear mitotic apparatus protein, was down regulated. These results demonstrate that significant biochemical alterations in nuclear matrix proteins take place during the apoptotic process.展开更多
FUS1 is a novel candidate tumor suppressor gene identified in human chromosome 3p21.3. Its expression showed significantly reduction or even loss in lung cancer and other types of cancers. In order to further investig...FUS1 is a novel candidate tumor suppressor gene identified in human chromosome 3p21.3. Its expression showed significantly reduction or even loss in lung cancer and other types of cancers. In order to further investigate the biological function of FUS1 protein, FUS1 cDNA from MRC-5 cells was amplified by RT-PCR and cloned into prokaryotic expression vector pQE-30. The recombinant expression plasmids were transformed into M15 strain and grown at 20℃ or 37℃. SDS–PAGE analysis revealed that the accumulation of the recombinant protein FUS1 (rFUS1) in inclusion body forms reached maxium amount when induced with 0.5 mM IPTG for 5 h at 37℃. The inclusion bodies were solubilized in 2M urea and purified by a 6 ×His tagged affinity column under denaturing condition. The purified rFUS1 was identified by electrospray ionization-mass spectrometry (ESI-MS) and tested for purity by HPLC chromatography. The purified rFUS1 proteins were then used to immunize rabbits to obtain anti-human FUS1 polyclonal antibodies, which were suitable to detect both the recombinant exogenous FUS1 and the endogenous FUS1 from tissues and cells by western blot and immunohistochemistry, Available purified rFUS1 proteins and self-prepared polyclonal antibodies against FUS1 may provide effective tools for further studies on biological function and application of FUS1.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
BACKGROUND Aberrant methylation in DNA regulatory regions could downregulate tumor suppressor genes without changing the sequences.However,our knowledge of secreted protein acidic and rich in cysteine(SPARC)and its ab...BACKGROUND Aberrant methylation in DNA regulatory regions could downregulate tumor suppressor genes without changing the sequences.However,our knowledge of secreted protein acidic and rich in cysteine(SPARC)and its aberrant methylation in gastric cancer(GC)is still inadequate.In the present research,we performed fundamental research to clarify the precise function of methylation on SPARC and its significance in GC.AIM To investigate promoter methylation and the effects of the SPARC gene in GC cells and tissues and to evaluate its clinical significance.METHODS Plasmids that overexpressed the SPARC gene were transfected into human GC BGC-823 cells;non-transfected cells were used as a control group(NC group).Quantitative real-time polymerase chain reaction and western blotting(WB)were then used to detect the expression of SPARC.Methylation-specific polymerase chain reaction was executed to analyze the gene promoter methylation status.Cell viability was measured by the cell counting kit-8 assay.The migration and invasion ability of cells were detected by scratch assays and transwell chamber assays,respectively.Cell cycle events and apoptosis were observed with a flow cytometer.RESULTS The expression of SPARC mRNA in GC tissues and cells was significantly lower and showed differing degrees of hypermethylation,respectively,than that in normal adjacent tissues and control cells.Treatment with 5-Aza-2’-deoxycytidine(5-Aza-Cdr)was able to restore the expression of SPARC and reverse promoter hypermethylation.Overexpression of the SPARC gene significantly inhibited proliferation,migration,and invasion of GC cells,while also causing cell cycle arrest and apoptosis;the NC group exhibited the opposite effects.CONCLUSION This study demonstrated that SPARC could function as a tumor suppressor and might be silenced by promoter hypermethylation.Furthermore,in GC cells,SPARC inhibited migration,invasion,and proliferation,caused cell cycle arrest at the G0/G1 phase,and promoted apoptosis.展开更多
p53 is a key tumor suppressor.As a transcription factor,p53 accumulates in cells in response to various stress signals and selectively transcribes its target genes to regulate a wide variety of cellular stress respons...p53 is a key tumor suppressor.As a transcription factor,p53 accumulates in cells in response to various stress signals and selectively transcribes its target genes to regulate a wide variety of cellular stress responses to exert its function in tumor suppression.In addition to tumor suppression,p53 is also involved in many other physiological and pathological processes,e.g.anti-infection,immune response,development,reproduction,neurodegeneration and aging.To maintain its proper function,p53 is under tight and delicate regulation through different mechanisms,particularly the posttranslational modifications.The tripartite motif(TRIM)family proteins are a large group of proteins characterized by the RING,B-Box and coiled-coil(RBCC)domains at the N-terminus.TRIM proteins play important roles in regulation of many fundamental biological processes,including cell proliferation and death,DNA repair,transcription,and immune response.Alterations of TRIM proteins have been linked to many diseases including cancer,infectious diseases,developmental disorders,and neurodegenera-tion.Interestingly,recent studies have revealed that many TRIM proteins are involved in the regulation of p53,and at the same time,many TRIM proteins are also regulated by p53.Here,we review the cross-talk between p53 and TRIM proteins,and its impact upon cellular biological processes as well as cancer and other diseases.展开更多
Objective:To investigate the effect of hepatitis C virus non-structural protein 4B(HCV NS4B) on c-Myc, P53, ras gene expression" and apoptosis in hepatic cells and study the possible role that NS4B played in the c...Objective:To investigate the effect of hepatitis C virus non-structural protein 4B(HCV NS4B) on c-Myc, P53, ras gene expression" and apoptosis in hepatic cells and study the possible role that NS4B played in the carcinogenesis of heparoma. Methods: The recombinant plasmid(PCXN2-NS4B, PCXN2-P53) and the empty, vector were transfected or co-transfected into Chang liver cells with liposome. Screening was performed with G418. Plasmid mRNA was detected by RT-PCR. The pro rein expressions of c-Myc and ras genes were analyzed by immunocytochemistry. The expressions of wild-type P53 (wtp53) gene were detected by in situ hybridization. TUNEL(flow cytometry) was used for assessing the rate of apoptosis. Results:No expression of c-Myc gene was found in PCXN2 group. The expression of c-Myc gene in NS4B group was 21.3% + 1.2%. The ex pression of ras gene in PCXN2 group was lower than that in NS4B group. Compared with PCXN2 group, the expression of P53 mRNA was not promoted or inhibited in NS4B group. But the expression of P53 mRNA in NS4B-P53 group was lower than that in P53 group. In PCXN2, NS4B, P53 and NS4B-P53 group, the rates of apoptosis were 17.02% ± 1.24%, 11.94% ± 2.24%, 25.84% ± 3.49% and 18.34% ± 1.55% respectively. Conclusion :HCV NS4B induces the expression of c-Myc and ras gene. HCV NS4B may play a role in the inhibition of cell death through P53-dependent manner. Results from this study suggested that HCV NS4B might contribute to the viral carcinogenesis.展开更多
文摘Objective YAP1 plays a dual role as an oncogene and tumor suppressor gene in several tumors;differentiating between these roles may depend on the YAP1 phosphorylation pattern.The specific function of YAP1 in B cell acute lymphoblastic leukemia(B-ALL),however,is currently unclear.Thus,in the present study,the role of YAP1 in B-ALL was investigated using relevant cell lines and patient datasets.Methods The effects of shRNA-mediated knockdown on YAP1 and LATS1 levels in the NALM6 and MOLT-4 cell lines were examined using Western blotting,quantitative real-time polymerase chain reaction,flow cytometry,immunostaining,and nude mouse subcutaneous tumorigenesis experiments.Gene expression levels of Hippo pathway-related molecules before and after verteporfin(VP)treatment were compared using RNA-Seq to identify significant Hippo pathway-related genes in NALM6 cells.Results Patients with ALL showing high YAP1 expression and low YAP1-Ser127 phosphorylation levels had worse prognoses than those with low YAP1 protein expression and high YAP1-Ser127 phosphorylation levels.YAP1-Ser127 phosphorylation levels were lower in NALM6 cells than in MOLT-4 and control cells;YAP1 was distributed in the nuclei in NALM6 cells.Knockdown of YAP1 inhibited MOLT-4 and NALM6 cell proliferation and arrested the NALM6 cell cycle in the G0/G1 phase.Before and after VP treatment,the expression of the upstream gene LATS1 was upregulated;its overexpression promoted YAP1-Ser127 phosphorylation.Further,YAP1 was distributed in the plasma.Conclusion LATS1 may downregulate YAP1-Ser127 phosphorylation and maintain B-ALL cell function;thus,VP,which targets this axis,may serve as a new therapeutic method for improving the outcomes for B-ALL patients.
基金Supported by the National Institutes of Health/National Cancer Institute Cancer Center Support grant P30 CA168524(DD)supported by a grant of the Geneva Cancer League(Grant no.1711)
文摘Trans-acting factors controlling mRNA fate are critical for the post-transcriptional regulation of inflammation-related genes, as well as for oncogene and tumor suppressor expression in human cancers. Among them, a group of RNA-binding proteins called "Adenylate-Uridylate-rich elements binding proteins"(AUBPs)control mRNA stability or translation through their binding to AU-rich elements enriched in the 3'UTRs of inflammation-and cancer-associated mRNA transcripts. AUBPs play a central role in the recruitment of target mRNAs into small cytoplasmic foci called Processing-bodies and stress granules(also known as P-body/SG). Alterations in the expression and activities of AUBPs and Pbody/SG assembly have been observed to occur with colorectal cancer(CRC)progression, indicating the significant role AUBP-dependent post-transcriptional regulation plays in controlling gene expression during CRC tumorigenesis.Accordingly, these alterations contribute to the pathological expression of many early-response genes involved in prostaglandin biosynthesis and inflammation,along with key oncogenic pathways. In this review, we summarize the current role of these proteins in CRC development. CRC remains a major cause of cancer mortality worldwide and, therefore, targeting these AUBPs to restore efficient post-transcriptional regulation of gene expression may represent an appealing therapeutic strategy.
基金Supported by the National Natural Science Foundation of China(No.81570814)Natural Science Foundation of Guangdong Province,China(No.2014A030313363)
文摘Pterygium is a common ocular surface disease induced by a variety of factors. The exact pathogenesis of pterygium remains unclear. Numbers of genes and proteins are discovered in pterygium and they function differently in the occurrence and development of this disease. We searched the Web of Science and PubMed throughout history for literatures about the subject. The keywords we used contain pterygium, gene, protein, angiogenesis, fibrosis, proliferation, inflammation, pathogenesis and therapy. In this review, we summarize the aberrant expression of a range of genes and proteins in pterygium compared with normal conjunctiva or cornea, including growth factors, matrix metalloproteinases and tissue inhibitors of mefalloproteinases, interleukins, tumor suppressor genes, proliferation related proteins, apoptosis related proteins, cell adhesion molecules, extracellular matrix proteins, heat shock proteins and tight junction proteins. We illustrate their possible mechanisms in the pathogenesis of pterygium as well as the related intervention based on them for pterygium therapy.
基金Project (Nos. 30200333 and 30570840) supported by the NationalNatural Science Foundation of China
文摘Insulin-like growth factor binding-protein-7 (IGFBP7) was obtained from our previous colonic adenocarcinoma (CRC) and normal mucosa suppression subtraction hybridization (SSH) cDNA libraries. By RT-PCR and immunohistochemistry, we found that IGFBP7 was overexpressed in CRC tissue compared to normal tissue. However, our in vitro experiments performed in 10 CRC cell lines showed that IGFBP7 expressed only in SW480 and Caco2 cell lines, which implied an underlying reversible regulatory mechanism. Using methylation-specific PCR (MSP) and bisulfite sodium PCR (BSP), we found that its expression was associated with DNA hypomethylation of exon1. This was further supported by the in vitro study which showed restored IGFBP7 expression after demethylation agent 5-aza-2’-deoxycytidine treatment. Correlation analysis between IGFBP7 expression and prognosis indicated that overexpression of IGFBP7 in CRC tissue correlated with favourable survival. Investigation of the func-tional role of IGFBP7 through transfection studies showed that IGFBP7 protein could inhibit growth rate, decrease colony for-mation activity, and induce apoptosis in RKO and SW620 cells, suggesting it a potential tumor suppressor protein in colorectal carcinogenesis. In conclusion, our study clearly demonstrated that IGFBP7 plays a potential tumor suppressor role against colo-rectal carcinogenesis and its expression is associated with DNA hypomethylation of exon 1.
基金Supported by the Medical Research Foundation of Guangdong Province,No.1997423
文摘INTRODUCTIONIn 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 .
文摘The events of cell death and the expression of nuclear matrix protein (NMP) have been investigated in a promyelocytic leukemic cell line HL-60 induced with etoposide. By means of TUNEL assay, the nuclei displayed a characteristic morphology change, and the amount of apoptotic cells increased early and reached maximun about 39% after treatment with etoposide for 2 h. Nucleosomal DNA fragmentation was observed after treatment for 4 h. The morphological change of HL-60 cells, thus, occurred earlier than the appearance of DNA ladder. Total nuclear matrix proteins were analyzed by 2-dimensional gel electrophoresis. Differential expression of 59 nuclear matrix proteins was found in 4 h etoposide treated cells. Western blotting was then performed on three nuclear matrix acssociated proteins, PML, HSC70 and NuMA. The expression of the suppressor PML protein and heat shock protein HSC70 were significantly upregulated after etoposide treatment, while NuMA, a nuclear mitotic apparatus protein, was down regulated. These results demonstrate that significant biochemical alterations in nuclear matrix proteins take place during the apoptotic process.
文摘FUS1 is a novel candidate tumor suppressor gene identified in human chromosome 3p21.3. Its expression showed significantly reduction or even loss in lung cancer and other types of cancers. In order to further investigate the biological function of FUS1 protein, FUS1 cDNA from MRC-5 cells was amplified by RT-PCR and cloned into prokaryotic expression vector pQE-30. The recombinant expression plasmids were transformed into M15 strain and grown at 20℃ or 37℃. SDS–PAGE analysis revealed that the accumulation of the recombinant protein FUS1 (rFUS1) in inclusion body forms reached maxium amount when induced with 0.5 mM IPTG for 5 h at 37℃. The inclusion bodies were solubilized in 2M urea and purified by a 6 ×His tagged affinity column under denaturing condition. The purified rFUS1 was identified by electrospray ionization-mass spectrometry (ESI-MS) and tested for purity by HPLC chromatography. The purified rFUS1 proteins were then used to immunize rabbits to obtain anti-human FUS1 polyclonal antibodies, which were suitable to detect both the recombinant exogenous FUS1 and the endogenous FUS1 from tissues and cells by western blot and immunohistochemistry, Available purified rFUS1 proteins and self-prepared polyclonal antibodies against FUS1 may provide effective tools for further studies on biological function and application of FUS1.
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。
基金Supported by the Natural Science Foundation of Liaoning Province,No.201602817
文摘BACKGROUND Aberrant methylation in DNA regulatory regions could downregulate tumor suppressor genes without changing the sequences.However,our knowledge of secreted protein acidic and rich in cysteine(SPARC)and its aberrant methylation in gastric cancer(GC)is still inadequate.In the present research,we performed fundamental research to clarify the precise function of methylation on SPARC and its significance in GC.AIM To investigate promoter methylation and the effects of the SPARC gene in GC cells and tissues and to evaluate its clinical significance.METHODS Plasmids that overexpressed the SPARC gene were transfected into human GC BGC-823 cells;non-transfected cells were used as a control group(NC group).Quantitative real-time polymerase chain reaction and western blotting(WB)were then used to detect the expression of SPARC.Methylation-specific polymerase chain reaction was executed to analyze the gene promoter methylation status.Cell viability was measured by the cell counting kit-8 assay.The migration and invasion ability of cells were detected by scratch assays and transwell chamber assays,respectively.Cell cycle events and apoptosis were observed with a flow cytometer.RESULTS The expression of SPARC mRNA in GC tissues and cells was significantly lower and showed differing degrees of hypermethylation,respectively,than that in normal adjacent tissues and control cells.Treatment with 5-Aza-2’-deoxycytidine(5-Aza-Cdr)was able to restore the expression of SPARC and reverse promoter hypermethylation.Overexpression of the SPARC gene significantly inhibited proliferation,migration,and invasion of GC cells,while also causing cell cycle arrest and apoptosis;the NC group exhibited the opposite effects.CONCLUSION This study demonstrated that SPARC could function as a tumor suppressor and might be silenced by promoter hypermethylation.Furthermore,in GC cells,SPARC inhibited migration,invasion,and proliferation,caused cell cycle arrest at the G0/G1 phase,and promoted apoptosis.
基金This work was supported in part by grants from NIH(grant number R01CA214746)DOD(grant number BC171968)to Z.F.+1 种基金by grants from NIH(grant number R01CA203965)DOD(grant number W81XWH-16-1-0358)to W.H.
文摘p53 is a key tumor suppressor.As a transcription factor,p53 accumulates in cells in response to various stress signals and selectively transcribes its target genes to regulate a wide variety of cellular stress responses to exert its function in tumor suppression.In addition to tumor suppression,p53 is also involved in many other physiological and pathological processes,e.g.anti-infection,immune response,development,reproduction,neurodegeneration and aging.To maintain its proper function,p53 is under tight and delicate regulation through different mechanisms,particularly the posttranslational modifications.The tripartite motif(TRIM)family proteins are a large group of proteins characterized by the RING,B-Box and coiled-coil(RBCC)domains at the N-terminus.TRIM proteins play important roles in regulation of many fundamental biological processes,including cell proliferation and death,DNA repair,transcription,and immune response.Alterations of TRIM proteins have been linked to many diseases including cancer,infectious diseases,developmental disorders,and neurodegenera-tion.Interestingly,recent studies have revealed that many TRIM proteins are involved in the regulation of p53,and at the same time,many TRIM proteins are also regulated by p53.Here,we review the cross-talk between p53 and TRIM proteins,and its impact upon cellular biological processes as well as cancer and other diseases.
基金Scientific Research Fund of Sichuan Provincial Education Department(20003531)
文摘Objective:To investigate the effect of hepatitis C virus non-structural protein 4B(HCV NS4B) on c-Myc, P53, ras gene expression" and apoptosis in hepatic cells and study the possible role that NS4B played in the carcinogenesis of heparoma. Methods: The recombinant plasmid(PCXN2-NS4B, PCXN2-P53) and the empty, vector were transfected or co-transfected into Chang liver cells with liposome. Screening was performed with G418. Plasmid mRNA was detected by RT-PCR. The pro rein expressions of c-Myc and ras genes were analyzed by immunocytochemistry. The expressions of wild-type P53 (wtp53) gene were detected by in situ hybridization. TUNEL(flow cytometry) was used for assessing the rate of apoptosis. Results:No expression of c-Myc gene was found in PCXN2 group. The expression of c-Myc gene in NS4B group was 21.3% + 1.2%. The ex pression of ras gene in PCXN2 group was lower than that in NS4B group. Compared with PCXN2 group, the expression of P53 mRNA was not promoted or inhibited in NS4B group. But the expression of P53 mRNA in NS4B-P53 group was lower than that in P53 group. In PCXN2, NS4B, P53 and NS4B-P53 group, the rates of apoptosis were 17.02% ± 1.24%, 11.94% ± 2.24%, 25.84% ± 3.49% and 18.34% ± 1.55% respectively. Conclusion :HCV NS4B induces the expression of c-Myc and ras gene. HCV NS4B may play a role in the inhibition of cell death through P53-dependent manner. Results from this study suggested that HCV NS4B might contribute to the viral carcinogenesis.