AIM： To explore the molecular events taking place during human colon cancer development and progression through high-throughput tissue microarray analysis. METHODS： We constructed two separate tissue microarrays con...AIM： To explore the molecular events taking place during human colon cancer development and progression through high-throughput tissue microarray analysis. METHODS： We constructed two separate tissue microarrays containing 1.0 mm or 1.5 mm cylindrical samples acquired from 112 formalin-fixed and paraffinembedded blocks, including carcinomas （n = 85）, adenomatous polyps （n = 18）, as well as normal paracancerous colon tissues （n = 9）. Immunohistochemical staining was applied to the analysis of the consecutive tissue microarray sections with antibodies for 11 different proteins, including p53, p21, bcl-2, bax, cyclin D1, PTEN, p-Aktl, β-catenin, c-myc, nm23-h1 and Cox-2. RESULTS： The protein expressions of p53, bcl-2, bax, cyclin D1, β-catenin, c-myc, Cox-2 and nm23-h1 varied significantly among tissues from cancer, adenomatous polyps and normal colon mucosa （P = 0.003, P = 0.001, P = 0.000, P = 0.000, P = 0.034, P = 0.003, P = 0.002, and P = 0.007, respectively）. Chi-square analysis showed that the statistically significant variables were p53, p21, bax, β-catenin, c-myc, PTEN, p-Aktl, Cox-2 and nm23-h1 for histological grade （P = 0.005, P = 0.013, P = 0.044, P = 0.000, P = 0.000, P = 0.029, P = 0.000, P = 0.008, and P = 0.000, respectively）, β-catenin, comyc and p-Akt1 for lymph node metastasis （P = 0.011, P =0.005, and P = 0.032, respectively）, β-catenin, c-myc, Cox-2 and nm23-h1 for distance metastasis （P = 0.020, P = 0.000, P = 0.026, and P = 0.008, respectively）, and cyclin D1, β-catenin, c-myc, Cox-2 and nm23h1 for clinical stages （P = 0.038, P = 0.008, P = 0.000, P = 0.016, and P = 0.014, respectively）. CONCLUSION： Tissue microarray immunohistochemical staining enables high-throughput analysis of genetic alterations contributing to human colon cancer development and progression. Our results implicate the potential roles of p53, cyclin D1, bcl-2, bax, Cox-2, β-catenin and c-myc in development of human colon cancer and that of bcl-2, nm23-h1, PTEN and p-Akt1 in progression of human colon cancer.展开更多
Human cytosolic NADP-1DH （IDH1） has recently been found to be involved in tumorigenesis. Notably, the tumorderived IDH1 mutations identified so far mainly occur at Arg132, and mutation R132H is the most prevalent on...Human cytosolic NADP-1DH （IDH1） has recently been found to be involved in tumorigenesis. Notably, the tumorderived IDH1 mutations identified so far mainly occur at Arg132, and mutation R132H is the most prevalent one. This mutation impairs the oxidative IDH activity of the enzyme, but renders a new reduction function of converting a-ketoglutarate （aKG） to 2-hydroxyglutarate. Here, we report the structures of the R132H mutant IDH1 with and without isocitrate OCT） bound. The structural data together with mutagenesis and biochemical data reveal a previ- ously undefined initial ICT-binding state and demonstrate that IDH activity requires a conformational change to a closed pre-transition state. Arg132 plays multiple functional roles in the catalytic reaction; in particular, the R132H mutation hinders the conformational changes from the initial ICT-binding state to the pre-transition state, leading to the impairment of the IDH activity. Our results describe for the first time that there is an intermediate conformation that corresponds to an initial ICT-binding state and that the R132H mutation can trap the enzyme in this conforma- tion, therefore shedding fight on the molecular mechanism of the ＂off switch＂ of the potentially tumor-suppressive IDH activity. Furthermore, we proved the necessity of Tyr139 for the gained aKG reduction activity and propose that Tyr139 may play a vital role by compensating the increased negative charge on the C2 atom of aKG during the trans- fer of a hydride anion from NADPH to aKG, which provides new insights into the mechanism of the ＂on switch＂ of the hypothetically oncogenic reduction activity of IDH1 by this mutation.展开更多
MicroRNAs （miRNAs） are a class of non-coding RNAs that are believed to have a significant role in tumorigenesis and cancer metastasis. Cancer stem cells play a major role in tumor recurrence, metastasis, and drug re...MicroRNAs （miRNAs） are a class of non-coding RNAs that are believed to have a significant role in tumorigenesis and cancer metastasis. Cancer stem cells play a major role in tumor recurrence, metastasis, and drug resistance. Research has shown that miRNAs can promote or inhibit the sternness of cancer stem cells and regulate the differentiation and self-renewal of cancer stem cells. In this article, the phenotype and regulatory mechanisms of miRNAs in cancer stem cells will be described, together with an explanation of their potential role in tumor diagnosis and treatment.展开更多
基金Supported by grant from the National 863 Project about Functional Genomic and Biochip, No. 2002AA2Z2021 and 135 Medical Important Talent Foundation of Jiangsu Province, No. 37RC2002037
文摘AIM： To explore the molecular events taking place during human colon cancer development and progression through high-throughput tissue microarray analysis. METHODS： We constructed two separate tissue microarrays containing 1.0 mm or 1.5 mm cylindrical samples acquired from 112 formalin-fixed and paraffinembedded blocks, including carcinomas （n = 85）, adenomatous polyps （n = 18）, as well as normal paracancerous colon tissues （n = 9）. Immunohistochemical staining was applied to the analysis of the consecutive tissue microarray sections with antibodies for 11 different proteins, including p53, p21, bcl-2, bax, cyclin D1, PTEN, p-Aktl, β-catenin, c-myc, nm23-h1 and Cox-2. RESULTS： The protein expressions of p53, bcl-2, bax, cyclin D1, β-catenin, c-myc, Cox-2 and nm23-h1 varied significantly among tissues from cancer, adenomatous polyps and normal colon mucosa （P = 0.003, P = 0.001, P = 0.000, P = 0.000, P = 0.034, P = 0.003, P = 0.002, and P = 0.007, respectively）. Chi-square analysis showed that the statistically significant variables were p53, p21, bax, β-catenin, c-myc, PTEN, p-Aktl, Cox-2 and nm23-h1 for histological grade （P = 0.005, P = 0.013, P = 0.044, P = 0.000, P = 0.000, P = 0.029, P = 0.000, P = 0.008, and P = 0.000, respectively）, β-catenin, comyc and p-Akt1 for lymph node metastasis （P = 0.011, P =0.005, and P = 0.032, respectively）, β-catenin, c-myc, Cox-2 and nm23-h1 for distance metastasis （P = 0.020, P = 0.000, P = 0.026, and P = 0.008, respectively）, and cyclin D1, β-catenin, c-myc, Cox-2 and nm23h1 for clinical stages （P = 0.038, P = 0.008, P = 0.000, P = 0.016, and P = 0.014, respectively）. CONCLUSION： Tissue microarray immunohistochemical staining enables high-throughput analysis of genetic alterations contributing to human colon cancer development and progression. Our results implicate the potential roles of p53, cyclin D1, bcl-2, bax, Cox-2, β-catenin and c-myc in development of human colon cancer and that of bcl-2, nm23-h1, PTEN and p-Akt1 in progression of human colon cancer.
文摘Human cytosolic NADP-1DH （IDH1） has recently been found to be involved in tumorigenesis. Notably, the tumorderived IDH1 mutations identified so far mainly occur at Arg132, and mutation R132H is the most prevalent one. This mutation impairs the oxidative IDH activity of the enzyme, but renders a new reduction function of converting a-ketoglutarate （aKG） to 2-hydroxyglutarate. Here, we report the structures of the R132H mutant IDH1 with and without isocitrate OCT） bound. The structural data together with mutagenesis and biochemical data reveal a previ- ously undefined initial ICT-binding state and demonstrate that IDH activity requires a conformational change to a closed pre-transition state. Arg132 plays multiple functional roles in the catalytic reaction; in particular, the R132H mutation hinders the conformational changes from the initial ICT-binding state to the pre-transition state, leading to the impairment of the IDH activity. Our results describe for the first time that there is an intermediate conformation that corresponds to an initial ICT-binding state and that the R132H mutation can trap the enzyme in this conforma- tion, therefore shedding fight on the molecular mechanism of the ＂off switch＂ of the potentially tumor-suppressive IDH activity. Furthermore, we proved the necessity of Tyr139 for the gained aKG reduction activity and propose that Tyr139 may play a vital role by compensating the increased negative charge on the C2 atom of aKG during the trans- fer of a hydride anion from NADPH to aKG, which provides new insights into the mechanism of the ＂on switch＂ of the hypothetically oncogenic reduction activity of IDH1 by this mutation.
文摘MicroRNAs （miRNAs） are a class of non-coding RNAs that are believed to have a significant role in tumorigenesis and cancer metastasis. Cancer stem cells play a major role in tumor recurrence, metastasis, and drug resistance. Research has shown that miRNAs can promote or inhibit the sternness of cancer stem cells and regulate the differentiation and self-renewal of cancer stem cells. In this article, the phenotype and regulatory mechanisms of miRNAs in cancer stem cells will be described, together with an explanation of their potential role in tumor diagnosis and treatment.
