AIM: To investigate the roles and interactions of mut T homolog(MTH)-1 and hypoxia-inducible factor(HIF)-1α in human colorectal cancer(CRC).METHODS: The expression and distribution of HIF-1α and MTH-1 proteins were ...AIM: To investigate the roles and interactions of mut T homolog(MTH)-1 and hypoxia-inducible factor(HIF)-1α in human colorectal cancer(CRC).METHODS: The expression and distribution of HIF-1α and MTH-1 proteins were detected in human CRC tissues by immunohistochemistry and quantitative realtime polymerase chain reaction(q RT-PCR). SW480 and HT-29 cells were exposed to normoxia or hypoxia. Protein and m RNA levels of HIF-1α and MTH-1 were analyzed by western blotting and q RT-PCR, respectively. In order to determine the effect of HIF-1α on the expression of MTH-1 and the amount of 8-oxodeoxyguanosine triphosphate(d GTP) in SW480 and HT-29 cells, HIF-1α was silenced with small interfering RNA(si RNA). Growth studies were conducted on cells with HIF-1α inhibition using a xenograft tumor model. Finally, MTH-1 protein was detected by western blotting in vivo.RESULTS: High MTH-1 m RNA expression was detected in 64.2% of cases(54/84), and this was significantly correlated with tumor stage(P = 0.023) and size(P = 0.043). HIF-1α protein expression was correlated significantly with MTH-1 expression(R = 0.640; P < 0.01) in human CRC tissues. Hypoxic stress induced m RNA and protein expression of MTH-1 in SW480 and HT-29 cells. Inhibition of HIF-1α by si RNA decreased the expression of MTH-1 and led to the accumulation of 8-oxo-d GTP in SW480 and HT-29 cells. In the in vivo xenograft tumor model, expression of MTH-1 was decreased in the HIF-1α si RNA group, and the tumor volume was much smaller than that in the mock si RNA group.CONCLUSION: MTH-1 expression in CRC cells was upregulated via HIF-1α in response to hypoxic stress, emphasizing the crucial role of HIF-1α-induced MTH-1 in tumor growth.展开更多
目的:研究抗肿瘤靶点人MutT同源体1蛋白(Human MutT Homolog-1,MTH1)抑制剂的构效关系,构建药效团筛选模型筛选潜在的MTH1抑制剂。方法:采用计算机辅助药物设计方法,通过Discovery Studio 3.0软件包中分子共同特征药效团HipHop算法,使...目的:研究抗肿瘤靶点人MutT同源体1蛋白(Human MutT Homolog-1,MTH1)抑制剂的构效关系,构建药效团筛选模型筛选潜在的MTH1抑制剂。方法:采用计算机辅助药物设计方法,通过Discovery Studio 3.0软件包中分子共同特征药效团HipHop算法,使用14个已知MTH1抑制剂分子作为训练集构建药效团模型,并通过Decoy Set验证准确性。结果:获得富集率为13.1的HipHop药效团模型,通过分子对接验证虚拟筛选出的75个候选化合物,得到先导化合物GK01945和HTS07767,能与受体形成良好的相互作用。结论:构建的药效团模型可以作为筛选模型,筛选出的MTH1潜在抑制剂,为抗肿瘤药物MTH1抑制剂开发提供了新思路。展开更多
目的探讨MutT同源酶1(MutThomolog1,MTH1)在乳腺导管内增生性病变及浸润性乳腺癌中的表达及与临床病理指标的关系。方法用免疫组化S-P法检测29例正常乳腺组织(normal breast tissues)、28例普通型导管增生(usual ductal hyperplasia,UDH...目的探讨MutT同源酶1(MutThomolog1,MTH1)在乳腺导管内增生性病变及浸润性乳腺癌中的表达及与临床病理指标的关系。方法用免疫组化S-P法检测29例正常乳腺组织(normal breast tissues)、28例普通型导管增生(usual ductal hyperplasia,UDH)、23例柱状细胞病变(columnar cell lesions,CCL)、27例非典型导管增生(atypical ductal hyperplasia,ADH)、30例导管原位癌(ductal carcinoma in situ,DCIS)和67例浸润性乳腺癌(invasive breast cancer,IBC)中MTH1的表达情况。结果 MTH1蛋白在正常乳腺、UDH、CCL、ADH、DCIS、IBC中表达的总阳性率分别为10.3%(3/29)、32.1%(9/28)、52.2%(12/23)、59.3%(16/27)、90.0%(27/30)、93.3%(63/67),其表达水平之间差异有统计学意义(χ~2=84.968,P<0.001)。多组间两两比较结果显示,DCIS组和IBC组MTH1蛋白表达均高于正常乳腺组织(χ~2=37.435、65.974,P<0.005)、UDH组(χ~2=20.592、41.219,P<0.005)和CCL组(χ~2=9.583、21.598,P<0.005)。MTH1的表达与肿瘤大小、年龄、淋巴结是否转移、ER、PR、HER-2表达无明显相关性。结论对乳腺导管内增生性病变行MTH1检测有利于早期发现浸润性乳腺癌。通过监测乳腺导管内增生性病变中MTH1蛋白的表达判断病变可能发生恶性转化的风险,并可能通过应用MTH1抑制剂减少乳腺癌的发生。展开更多
The MutT/Nudix superfamily proteins repair DNA damage and play a role in human health and disease. In this study, we examined two different cases of double MutT/Nudix domain-containing proteins from eukaryotes and pro...The MutT/Nudix superfamily proteins repair DNA damage and play a role in human health and disease. In this study, we examined two different cases of double MutT/Nudix domain-containing proteins from eukaryotes and prokaryotes. Firstly, these double domain proteins were discovered in Drosophila, but only single Nudix domain proteins were found in other animals. The phylogenetic tree was constructed based on the protein sequence of Nudix_N and Nudix_C from Drosophila, and Nudix from other animals. The phylogenetic analysis suggested that the double Nudix domain proteins might have undergone a gene duplication-speciation-fusion process. Secondly, two genes of the MutT family, DR0004 and DR0329, were fused by two mutT gene segments and formed double MutT domain protein genes in Deinococcus radiodurans. The evolutionary tree of bacterial MutT proteins suggested that the double MutT domain proteins in D. radiodurans probably resulted from a gene duplication-fusion event after speciation. Gene duplication-fusion is a basic and important gene innovation mechanism for the evolution of double MutT/Nudix domain proteins. Independent gene duplication-fusion events resuited in similar domain architectures of different double MutT/Nudix domain proteins.展开更多
目的探究MutT同源蛋白1(MutT homolog protein 1,MTH1)在结肠癌组织中的表达情况,以及下调MTH1对人结肠癌细胞SW480安罗替尼耐药的作用及其与自噬的关系。方法免疫组化染色法和实时荧光定量PCR(qRT-PCR)检测结肠癌组织和癌旁组织中MTH1...目的探究MutT同源蛋白1(MutT homolog protein 1,MTH1)在结肠癌组织中的表达情况,以及下调MTH1对人结肠癌细胞SW480安罗替尼耐药的作用及其与自噬的关系。方法免疫组化染色法和实时荧光定量PCR(qRT-PCR)检测结肠癌组织和癌旁组织中MTH1表达;通过低剂量反复刺激法构建安罗替尼的SW480耐药细胞株(SW480/Anl细胞);利用RNA干扰技术下调SW480/Anl细胞中MTH1表达;CCK-8法检测细胞增殖能力;Annexin V-FITC/PI双染法测定细胞凋亡率;免疫荧光染色检测细胞中LC-3表达;蛋白质印迹法(Western blotting)检测MTH1蛋白及自噬蛋白表达水平。结果结肠癌组织中MTH1表达水平较癌旁组织显著升高(P<0.05);经不同浓度安罗替尼处理后,SW480/Anl细胞存活率较SW480细胞显著升高(P<0.05)。与对照组比较,转染siRNA-MTH1后SW480/Anl细胞中MTH1 mRNA与蛋白表达显著下降(P<0.05),在安罗替尼(浓度为25、50、100、150、200μmol/L)作用下细胞存活率均显著下降(P<0.05),细胞凋亡率升高(P<0.05),LC3荧光染色较弱,P62蛋白表达水平显著增加,同时LC3-Ⅱ、Beclin-1蛋白表达水平显著下降(P<0.05)。结论MTH1在结肠癌组织中高表达,下调MTH1表达可抑制自噬的发生,从而逆转SW480细胞对安罗替尼的耐药。展开更多
基金Supported by The National Natural Science Foundation of ChinaNo.81330013 and No.81272078 to Yang H+2 种基金No.81270451 to Xiao WDthe Program for Changjiang Scholars and Innovative Research Team in UniversitiesNo.13051 to Yang H
文摘AIM: To investigate the roles and interactions of mut T homolog(MTH)-1 and hypoxia-inducible factor(HIF)-1α in human colorectal cancer(CRC).METHODS: The expression and distribution of HIF-1α and MTH-1 proteins were detected in human CRC tissues by immunohistochemistry and quantitative realtime polymerase chain reaction(q RT-PCR). SW480 and HT-29 cells were exposed to normoxia or hypoxia. Protein and m RNA levels of HIF-1α and MTH-1 were analyzed by western blotting and q RT-PCR, respectively. In order to determine the effect of HIF-1α on the expression of MTH-1 and the amount of 8-oxodeoxyguanosine triphosphate(d GTP) in SW480 and HT-29 cells, HIF-1α was silenced with small interfering RNA(si RNA). Growth studies were conducted on cells with HIF-1α inhibition using a xenograft tumor model. Finally, MTH-1 protein was detected by western blotting in vivo.RESULTS: High MTH-1 m RNA expression was detected in 64.2% of cases(54/84), and this was significantly correlated with tumor stage(P = 0.023) and size(P = 0.043). HIF-1α protein expression was correlated significantly with MTH-1 expression(R = 0.640; P < 0.01) in human CRC tissues. Hypoxic stress induced m RNA and protein expression of MTH-1 in SW480 and HT-29 cells. Inhibition of HIF-1α by si RNA decreased the expression of MTH-1 and led to the accumulation of 8-oxo-d GTP in SW480 and HT-29 cells. In the in vivo xenograft tumor model, expression of MTH-1 was decreased in the HIF-1α si RNA group, and the tumor volume was much smaller than that in the mock si RNA group.CONCLUSION: MTH-1 expression in CRC cells was upregulated via HIF-1α in response to hypoxic stress, emphasizing the crucial role of HIF-1α-induced MTH-1 in tumor growth.
文摘目的探讨MutT同源酶1(MutThomolog1,MTH1)在乳腺导管内增生性病变及浸润性乳腺癌中的表达及与临床病理指标的关系。方法用免疫组化S-P法检测29例正常乳腺组织(normal breast tissues)、28例普通型导管增生(usual ductal hyperplasia,UDH)、23例柱状细胞病变(columnar cell lesions,CCL)、27例非典型导管增生(atypical ductal hyperplasia,ADH)、30例导管原位癌(ductal carcinoma in situ,DCIS)和67例浸润性乳腺癌(invasive breast cancer,IBC)中MTH1的表达情况。结果 MTH1蛋白在正常乳腺、UDH、CCL、ADH、DCIS、IBC中表达的总阳性率分别为10.3%(3/29)、32.1%(9/28)、52.2%(12/23)、59.3%(16/27)、90.0%(27/30)、93.3%(63/67),其表达水平之间差异有统计学意义(χ~2=84.968,P<0.001)。多组间两两比较结果显示,DCIS组和IBC组MTH1蛋白表达均高于正常乳腺组织(χ~2=37.435、65.974,P<0.005)、UDH组(χ~2=20.592、41.219,P<0.005)和CCL组(χ~2=9.583、21.598,P<0.005)。MTH1的表达与肿瘤大小、年龄、淋巴结是否转移、ER、PR、HER-2表达无明显相关性。结论对乳腺导管内增生性病变行MTH1检测有利于早期发现浸润性乳腺癌。通过监测乳腺导管内增生性病变中MTH1蛋白的表达判断病变可能发生恶性转化的风险,并可能通过应用MTH1抑制剂减少乳腺癌的发生。
基金supported by the National Basic Research Program of China (No. 2004CB19604)the National Hi-Tech Development Program (No. 2007AA021305)+1 种基金the National Natural Science Foundation of China (No.30830006)the Project "Application of Nuclear Techniques in Agriculture" from the Chinese Ministry of Agriculture (No. 200803034) to YJH.
文摘The MutT/Nudix superfamily proteins repair DNA damage and play a role in human health and disease. In this study, we examined two different cases of double MutT/Nudix domain-containing proteins from eukaryotes and prokaryotes. Firstly, these double domain proteins were discovered in Drosophila, but only single Nudix domain proteins were found in other animals. The phylogenetic tree was constructed based on the protein sequence of Nudix_N and Nudix_C from Drosophila, and Nudix from other animals. The phylogenetic analysis suggested that the double Nudix domain proteins might have undergone a gene duplication-speciation-fusion process. Secondly, two genes of the MutT family, DR0004 and DR0329, were fused by two mutT gene segments and formed double MutT domain protein genes in Deinococcus radiodurans. The evolutionary tree of bacterial MutT proteins suggested that the double MutT domain proteins in D. radiodurans probably resulted from a gene duplication-fusion event after speciation. Gene duplication-fusion is a basic and important gene innovation mechanism for the evolution of double MutT/Nudix domain proteins. Independent gene duplication-fusion events resuited in similar domain architectures of different double MutT/Nudix domain proteins.
