AIM:To investigate the role of FAT10 and mutant p53 in the pathogenesis,severity and prognosis of gastric cancer.METHODS:FAT10,mutant p53 mRNA and protein levels were measured by reverse transcription(RT)-PCR and immu...AIM:To investigate the role of FAT10 and mutant p53 in the pathogenesis,severity and prognosis of gastric cancer.METHODS:FAT10,mutant p53 mRNA and protein levels were measured by reverse transcription(RT)-PCR and immunohistochemistry in gastric cancer tissue(n = 62),tumoradjacent tissue(n = 62) and normal gastric tissue(n = 62).Relation of FAT10 and mutant p53 expression with clinicopathological features and clinical outcomes of gastric cancer patients were analyzed.RESULTS:The FAT10,mutant p53 mRNA and protein levels were signif icantly higher in gastric cancer than in its adjacent and normal tissue.The FAT10 and mutant p53 levels in gastric cancer tissue were significantly correlated with lymph node metastasis and tumor,nodes,metastasis(TNM) staging.Moreover,the high FAT10 level was associated with the overall survival rate of patients.Multivariate Cox-proportional hazards model analysis showed that mRNA and protein levels of FAT10 and mutant p53,lymph node metastasis,distant metastasis and TNM stage were the independent prognostic factors for gastric cancer.CONCLUSION:FAT10 may be involved in gastric carcinogenesis,and is a potential marker for the prognosis of gastric cancer patients.FAT10 and mutant p53 may play a common role in the carcinogenesis of gastric cancer.展开更多
p53蛋白是人体内十分重要的肿瘤抑制因子,通过调节细胞周期阻滞、诱导细胞凋亡等作用发挥肿瘤抑制功能。突变后的p53蛋白不仅具有显性负性效应(dominant negative effect,DN)抑制野生型p53蛋白功能,而且还通过功能获得性效应(gain of fu...p53蛋白是人体内十分重要的肿瘤抑制因子,通过调节细胞周期阻滞、诱导细胞凋亡等作用发挥肿瘤抑制功能。突变后的p53蛋白不仅具有显性负性效应(dominant negative effect,DN)抑制野生型p53蛋白功能,而且还通过功能获得性效应(gain of function,GOF)调节细胞代谢、侵袭、迁移等方式促进肿瘤的发生。p53蛋白在超过50%的肿瘤组织中发生突变,是肿瘤细胞区别于正常细胞的一个特异性药物靶点。因此,针对突变p53蛋白开发新型抗癌药物一直是研究的热点。长期以来,由于突变p53蛋白表面较为光滑,缺乏药物结合口袋,使其被认为是一个不可成药的靶点。随着高通量筛选技术的发展以及对突变p53蛋白结构的深入了解,许多靶向突变p53蛋白的小分子化合物被报道并在体外展现出较好的抗肿瘤活性,多款基于突变p53蛋白研发的化合物已经进入临床试验阶段。本文就靶向p53蛋白治疗肿瘤的直接和间接策略进行综述,重点针对突变p53蛋白重激活剂与降解突变p53蛋白的小分子化合物作用机制进行梳理,以期为后续开发靶向突变p53蛋白药物的创新提供帮助。展开更多
Objective To investigate the role of mutated mismatch repair gene hMSH2 and mutant p53 gene in the carcinogenesis and development of sporadic digestive tract tumors. Methods hMSH2 gene in normal and tumor tissue of...Objective To investigate the role of mutated mismatch repair gene hMSH2 and mutant p53 gene in the carcinogenesis and development of sporadic digestive tract tumors. Methods hMSH2 gene in normal and tumor tissue of 30 digestive tract tumor specimens was examined using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) silver staining. The PCR product with an abnormal strand was sequenced directly. Mutant p53 protein in the tumor tissue was analyzed immunohistochemically. Results Six patients were identified as having mutated strands, three on hMSH2 exon 1 and three on hMSH2 exon 5. DNA sequencing revealed that all 6 patients had mutated basic groups that led to decrease in function of the hMSH2 protein. Forty percent (12/30) of patients were p53 positive. The frequency of mutated hMSH2 in p53 positive patients (41.7%) was significantly higher than in p53 negative patients (5.6%, P<0.05). Conclusion The mutation of hMSH2 plays an important role in the carcinogenesis and development of digestive tract tumors through stimulating p53 mutation.展开更多
B-cell CLL/lymphoma 7 protein family member C (BCL7C) located at chromosome 16p11.2 shares partial sequence homology with the other two family members, BCL7A and BCL7B. Its role in cancer remains completely unknown. H...B-cell CLL/lymphoma 7 protein family member C (BCL7C) located at chromosome 16p11.2 shares partial sequence homology with the other two family members, BCL7A and BCL7B. Its role in cancer remains completely unknown. Here, we report our finding of its tumor-suppressive role in ovarian cancer. Supporting this is that BCL7C is downregulated in human ovarian carcinomas, and its underexpression is associated with unfavorable prognosis of ovarian cancer as well as some other types of human cancers. Also, ectopic BCL7C restrains cell proliferation and invasion of ovarian cancer cells. Consistently, depletion of BCL7C reduces apoptosis and promotes cell proliferation and invasion of these cancer cells. Mechanistically, BCL7C suppresses mutant p53-mediated gene transcription by binding to mutant p53, while knockdown of BCL7C enhances the expression of mutant p53 target genes in ovarian cancer cells. Primary ovarian carcinomas that sustain low levels of BCL7C often show the elevated expression of mutant p53 target genes. In line with these results, BCL7C abrogates mutant p53-induced cell proliferation and invasion, but had no impact on proliferation and invasion of cancer cells with depleted p53 or harboring wild-type p53. Altogether, our results demonstrate that BCL7C can act as a tumor suppressor to prevent ovarian tumorigenesis and progression by counteracting mutant p53 activity.展开更多
The deltex family protein DTX3 is believed to possess E3 ubiquitin ligase activity,as it contains a classic RING finger domain.However,its biological role and the underlying mechanism in cancer remain largely elusive....The deltex family protein DTX3 is believed to possess E3 ubiquitin ligase activity,as it contains a classic RING finger domain.However,its biological role and the underlying mechanism in cancer remain largely elusive.Here,we identified DTX3 as a novel mutant p53-interacting protein in ovarian carcinoma.Mechanistically,DTX3 mediated mutant p53 ubiqui-tination and stabilization by perturbing the MDM2-mutant p53 interaction,consequently leading to activation of diverse.mutant p53 target genes.Importantly,a positive correlation between the expression of DTX3 and mutant p53 target genes was further validated in ovarian carcinomas.Ectopic DTX3 promoted,while depletion of DTX3 suppressed,ovarian cancer cell proliferation and invasion.Remarkably,the pro-tumorigenic effect of DTX3 is dependent on mutant p53,because ablation of mutant p53 significantly impaired DTX3-induced gene expression and ovarian cancer cell growth and propagation.Furthermore,DTX3 elevated the expressi on of muta nt p53 target genes and boosted ovarian tumor growth in vivo.Fin ally,DTX3 was amplified and overexpressed in ovarian carci no mas,which is sign ificantly associated with unfavorable prognosis.Altogether,our findings unveil the oncogenic role of DTX3 in ovarian cancer development by bolstering mutant p53 activity.展开更多
The tumor suppressor p53 protein is either lost or mutated in about half of all human cancers.Loss of p53 function is well known to influence cell spreading,migration and invasion.While expression of mutant p53 is not...The tumor suppressor p53 protein is either lost or mutated in about half of all human cancers.Loss of p53 function is well known to influence cell spreading,migration and invasion.While expression of mutant p53 is not equivalent to p53 loss,mutant p53 can acquire new functions to drive cell spreading and migration via different mechanisms.In our study,we found that mutant p53 significantly increased cell spreading and migration when comparing with p53-null cells.RNA-Seq analysis suggested that Rho GTPase activating protein 44(ARHGAP44) is a new target of mutant p53,which suppressed AKHGAP44 transcription.ARHGAP44 has GAP activity and catalyze GTP hydrolysis on Cdc42.Higher level of GTP-Cdc42 was correlated with increase expression of mutant p53 and reduced ARHGAP44.Importantly,wt-ARHGAP44 but not mutant ARHGAP44(R291A) suppressed mutant p53 mediated cell spreading and migration.Bioinformatics analysis indicated lower expression of ARHGAP44 in lung carcinoma compared with normal tissues,which was verified by RT-qPCR using specimens from patients.More interestingly,ARHGAP44 mRNA level was lower in tumors with mutant p53 than those with normal p53.Collectively,our results disclose a new mechanism by which mutant p53 stimulates cell spreading and migration.展开更多
AIM:To investigate the mutation of p 53 immuno-histochemically in non-tumorous gastric mucosa with H pylori infection before and after H pylori eradication therapy.METHODS:53 subjects(36 male,17 female,mean age ±...AIM:To investigate the mutation of p 53 immuno-histochemically in non-tumorous gastric mucosa with H pylori infection before and after H pylori eradication therapy.METHODS:53 subjects(36 male,17 female,mean age ± SEM,57.1 ± 12.1)undergoing endoscopic examination were included in this study.42 of 53 patients were H pylori-positive,and 11 were H pylori-negative.All H pylori-positive patients had successful eradication therapy.Biopsy specimens were taken from five points of the stomach,as recommended by the updated Sydney system.Immunohistochemical studies were performed by using primary antibodies against p53(DO-7 and PAb240).RESULTS:p53(DO-7 and PAb240)immunoreactivity was shown in the neck region of the gastric pits,however,quite a few cells were found to be immunopositive for p 53(PAb240)in the H pylori-infected gastric mucosa.The proportion of patients immunopositive for p 53(PAb240)was significantly reduced 6 mo after eradication [28/42(66.7%)to 6/42(14.3%)](P < 0.05),while the biopsies taken from H pylori-negative patients showed no immunoreactivity for p53(PAb240).p53(PAb240)-positive patients were divided into two groups by the number of positive cells detected:one with more than six positive cells per 10 gastric pits(group A,n = 12),and the other with less than five positive cells per 10 gastric pits(group B,n = 30).Atrophy scores in group A were significant higher than those in group B at the greater curvature of the antrum(group A:2.00 ± 0.14 vs group B:1.40 ± 0.15,P = 0.012),the lesser curvature of the corpus(group A:2.00 ± 0.21 vs group B:1.07 ± 0.23,P = 0.017),and the greater curvature of the corpus(group A:1.20 ± 0.30vs group B:0.47 ± 0.21,P = 0.031).Group A showed significant higher intestinal metaplasia scores than group B only at the lesser curvature of the antrum(group A:2.10 ± 0.41 vs group B:1.12 ± 0.29,P = 0.035).CONCLUSION:H pylori-associated chronic gastritis expressed the mutant-type p53,which was significantly associated with more severe atrophic and metaplastic changes.H pylori eradication led to a significant reduction in the expression of the mutant-type p53.It is considered that H pylori-infected chronic gastritis is associated with a genetic instability that leads to gastric carcinogenesis,and H pylori eradication may prevent gastric cancer.展开更多
文摘AIM:To investigate the role of FAT10 and mutant p53 in the pathogenesis,severity and prognosis of gastric cancer.METHODS:FAT10,mutant p53 mRNA and protein levels were measured by reverse transcription(RT)-PCR and immunohistochemistry in gastric cancer tissue(n = 62),tumoradjacent tissue(n = 62) and normal gastric tissue(n = 62).Relation of FAT10 and mutant p53 expression with clinicopathological features and clinical outcomes of gastric cancer patients were analyzed.RESULTS:The FAT10,mutant p53 mRNA and protein levels were signif icantly higher in gastric cancer than in its adjacent and normal tissue.The FAT10 and mutant p53 levels in gastric cancer tissue were significantly correlated with lymph node metastasis and tumor,nodes,metastasis(TNM) staging.Moreover,the high FAT10 level was associated with the overall survival rate of patients.Multivariate Cox-proportional hazards model analysis showed that mRNA and protein levels of FAT10 and mutant p53,lymph node metastasis,distant metastasis and TNM stage were the independent prognostic factors for gastric cancer.CONCLUSION:FAT10 may be involved in gastric carcinogenesis,and is a potential marker for the prognosis of gastric cancer patients.FAT10 and mutant p53 may play a common role in the carcinogenesis of gastric cancer.
文摘p53蛋白是人体内十分重要的肿瘤抑制因子,通过调节细胞周期阻滞、诱导细胞凋亡等作用发挥肿瘤抑制功能。突变后的p53蛋白不仅具有显性负性效应(dominant negative effect,DN)抑制野生型p53蛋白功能,而且还通过功能获得性效应(gain of function,GOF)调节细胞代谢、侵袭、迁移等方式促进肿瘤的发生。p53蛋白在超过50%的肿瘤组织中发生突变,是肿瘤细胞区别于正常细胞的一个特异性药物靶点。因此,针对突变p53蛋白开发新型抗癌药物一直是研究的热点。长期以来,由于突变p53蛋白表面较为光滑,缺乏药物结合口袋,使其被认为是一个不可成药的靶点。随着高通量筛选技术的发展以及对突变p53蛋白结构的深入了解,许多靶向突变p53蛋白的小分子化合物被报道并在体外展现出较好的抗肿瘤活性,多款基于突变p53蛋白研发的化合物已经进入临床试验阶段。本文就靶向p53蛋白治疗肿瘤的直接和间接策略进行综述,重点针对突变p53蛋白重激活剂与降解突变p53蛋白的小分子化合物作用机制进行梳理,以期为后续开发靶向突变p53蛋白药物的创新提供帮助。
文摘Objective To investigate the role of mutated mismatch repair gene hMSH2 and mutant p53 gene in the carcinogenesis and development of sporadic digestive tract tumors. Methods hMSH2 gene in normal and tumor tissue of 30 digestive tract tumor specimens was examined using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) silver staining. The PCR product with an abnormal strand was sequenced directly. Mutant p53 protein in the tumor tissue was analyzed immunohistochemically. Results Six patients were identified as having mutated strands, three on hMSH2 exon 1 and three on hMSH2 exon 5. DNA sequencing revealed that all 6 patients had mutated basic groups that led to decrease in function of the hMSH2 protein. Forty percent (12/30) of patients were p53 positive. The frequency of mutated hMSH2 in p53 positive patients (41.7%) was significantly higher than in p53 negative patients (5.6%, P<0.05). Conclusion The mutation of hMSH2 plays an important role in the carcinogenesis and development of digestive tract tumors through stimulating p53 mutation.
基金X.Z.was supported by the National Natural ScienceFoundation of China(81672566 and 81874053)Q.H.was sup-ported by the National Natural Science Foundation of China(81702352)Y.Z.was supported by the Natural ScienceFoundation of Hunan Province of China(2018J6059).
文摘B-cell CLL/lymphoma 7 protein family member C (BCL7C) located at chromosome 16p11.2 shares partial sequence homology with the other two family members, BCL7A and BCL7B. Its role in cancer remains completely unknown. Here, we report our finding of its tumor-suppressive role in ovarian cancer. Supporting this is that BCL7C is downregulated in human ovarian carcinomas, and its underexpression is associated with unfavorable prognosis of ovarian cancer as well as some other types of human cancers. Also, ectopic BCL7C restrains cell proliferation and invasion of ovarian cancer cells. Consistently, depletion of BCL7C reduces apoptosis and promotes cell proliferation and invasion of these cancer cells. Mechanistically, BCL7C suppresses mutant p53-mediated gene transcription by binding to mutant p53, while knockdown of BCL7C enhances the expression of mutant p53 target genes in ovarian cancer cells. Primary ovarian carcinomas that sustain low levels of BCL7C often show the elevated expression of mutant p53 target genes. In line with these results, BCL7C abrogates mutant p53-induced cell proliferation and invasion, but had no impact on proliferation and invasion of cancer cells with depleted p53 or harboring wild-type p53. Altogether, our results demonstrate that BCL7C can act as a tumor suppressor to prevent ovarian tumorigenesis and progression by counteracting mutant p53 activity.
基金This study was supported by the National Natural Science Foundation of China(No.81672566,81874053,81972431,and 81702352)the Basic and Clinical Translational Research Fundi ng from Fudan University Sha nghai Cancer Center.
文摘The deltex family protein DTX3 is believed to possess E3 ubiquitin ligase activity,as it contains a classic RING finger domain.However,its biological role and the underlying mechanism in cancer remain largely elusive.Here,we identified DTX3 as a novel mutant p53-interacting protein in ovarian carcinoma.Mechanistically,DTX3 mediated mutant p53 ubiqui-tination and stabilization by perturbing the MDM2-mutant p53 interaction,consequently leading to activation of diverse.mutant p53 target genes.Importantly,a positive correlation between the expression of DTX3 and mutant p53 target genes was further validated in ovarian carcinomas.Ectopic DTX3 promoted,while depletion of DTX3 suppressed,ovarian cancer cell proliferation and invasion.Remarkably,the pro-tumorigenic effect of DTX3 is dependent on mutant p53,because ablation of mutant p53 significantly impaired DTX3-induced gene expression and ovarian cancer cell growth and propagation.Furthermore,DTX3 elevated the expressi on of muta nt p53 target genes and boosted ovarian tumor growth in vivo.Fin ally,DTX3 was amplified and overexpressed in ovarian carci no mas,which is sign ificantly associated with unfavorable prognosis.Altogether,our findings unveil the oncogenic role of DTX3 in ovarian cancer development by bolstering mutant p53 activity.
基金supported by the National Program on Key Basic Research Project(2015CB901402)the National Natural Science Foundation of China(91629103,31670882, 81471066,81261120555,81672883,81401837,31071875,31200878, 31100946)+1 种基金the Science and Technology Commission of Shanghai Municipality(14430712100,11ZR1410000,16ZR1410000,16QA1401500)the Applied Basic Research Program of Science and Technology Department of Sichuan Province(2015JY0038)
文摘The tumor suppressor p53 protein is either lost or mutated in about half of all human cancers.Loss of p53 function is well known to influence cell spreading,migration and invasion.While expression of mutant p53 is not equivalent to p53 loss,mutant p53 can acquire new functions to drive cell spreading and migration via different mechanisms.In our study,we found that mutant p53 significantly increased cell spreading and migration when comparing with p53-null cells.RNA-Seq analysis suggested that Rho GTPase activating protein 44(ARHGAP44) is a new target of mutant p53,which suppressed AKHGAP44 transcription.ARHGAP44 has GAP activity and catalyze GTP hydrolysis on Cdc42.Higher level of GTP-Cdc42 was correlated with increase expression of mutant p53 and reduced ARHGAP44.Importantly,wt-ARHGAP44 but not mutant ARHGAP44(R291A) suppressed mutant p53 mediated cell spreading and migration.Bioinformatics analysis indicated lower expression of ARHGAP44 in lung carcinoma compared with normal tissues,which was verified by RT-qPCR using specimens from patients.More interestingly,ARHGAP44 mRNA level was lower in tumors with mutant p53 than those with normal p53.Collectively,our results disclose a new mechanism by which mutant p53 stimulates cell spreading and migration.
基金Supported by Grants-in-Aid (C-14) from the Ministry of Health,Labor and Welfare,Japan
文摘AIM:To investigate the mutation of p 53 immuno-histochemically in non-tumorous gastric mucosa with H pylori infection before and after H pylori eradication therapy.METHODS:53 subjects(36 male,17 female,mean age ± SEM,57.1 ± 12.1)undergoing endoscopic examination were included in this study.42 of 53 patients were H pylori-positive,and 11 were H pylori-negative.All H pylori-positive patients had successful eradication therapy.Biopsy specimens were taken from five points of the stomach,as recommended by the updated Sydney system.Immunohistochemical studies were performed by using primary antibodies against p53(DO-7 and PAb240).RESULTS:p53(DO-7 and PAb240)immunoreactivity was shown in the neck region of the gastric pits,however,quite a few cells were found to be immunopositive for p 53(PAb240)in the H pylori-infected gastric mucosa.The proportion of patients immunopositive for p 53(PAb240)was significantly reduced 6 mo after eradication [28/42(66.7%)to 6/42(14.3%)](P < 0.05),while the biopsies taken from H pylori-negative patients showed no immunoreactivity for p53(PAb240).p53(PAb240)-positive patients were divided into two groups by the number of positive cells detected:one with more than six positive cells per 10 gastric pits(group A,n = 12),and the other with less than five positive cells per 10 gastric pits(group B,n = 30).Atrophy scores in group A were significant higher than those in group B at the greater curvature of the antrum(group A:2.00 ± 0.14 vs group B:1.40 ± 0.15,P = 0.012),the lesser curvature of the corpus(group A:2.00 ± 0.21 vs group B:1.07 ± 0.23,P = 0.017),and the greater curvature of the corpus(group A:1.20 ± 0.30vs group B:0.47 ± 0.21,P = 0.031).Group A showed significant higher intestinal metaplasia scores than group B only at the lesser curvature of the antrum(group A:2.10 ± 0.41 vs group B:1.12 ± 0.29,P = 0.035).CONCLUSION:H pylori-associated chronic gastritis expressed the mutant-type p53,which was significantly associated with more severe atrophic and metaplastic changes.H pylori eradication led to a significant reduction in the expression of the mutant-type p53.It is considered that H pylori-infected chronic gastritis is associated with a genetic instability that leads to gastric carcinogenesis,and H pylori eradication may prevent gastric cancer.
基金supported by the National Natural Science Foundation of China(Grant No.81001186)the Tianjin MunicipaNatural Science Foundation(Grant No.10JCYBJC14100)