Objective： Colorectal cancer（CRC） is one of the most common types of human cancers. As a tumor suppressor, SMAD4 plays a key role in colorectal carcinogenesis and invasiveness. Copy number variations（CNVs） of the...Objective： Colorectal cancer（CRC） is one of the most common types of human cancers. As a tumor suppressor, SMAD4 plays a key role in colorectal carcinogenesis and invasiveness. Copy number variations（CNVs） of the SMAD4 gene have been reported to be associated with cancer pathogenesis in array-based studies in different populations. Here we aimed to investigate the CNVs of the SMAD4 gene in a relatively large number of CRC patients from China. Methods： In the present study, we collected 147 Chinese CRC tumors as well as self-paired normal control tissues. Quantitative PCR was carried out to examine the copy number as well as the m RNA expression of the SMAD4 gene. Results： Our results showed that the copy number deletions of SMAD4 were frequent in a relatively high percentage of CRC samples（34.7%, 51 out of 147）. There was a positive correlation between the copy number decrease of SMAD4 and tumor progression in CRCs. Furthermore, copy number loss of SMAD4 was correlated with decreased m RNA expression.Conclusions： These findings suggested that the copy number deletions of SMAD4 were frequent in CRC patients from China and had the potential to serve as a diagnostic indicator, alone or in combination with other markers, for CRC.展开更多
OBJECTIVE： Methylation-specific epigenetic process and gene expression profiles of HeLa cells treated with ultra-high dilutions （HDs） of two plant extracts, Hydrastis canadensis （HC-30） and Marsdenia condurango ...OBJECTIVE： Methylation-specific epigenetic process and gene expression profiles of HeLa cells treated with ultra-high dilutions （HDs） of two plant extracts, Hydrastis canadensis （HC-30） and Marsdenia condurango （Condu-30）, diluted 106o times, were analyzed against placebo 30C （PI-30） for alterations in gene profiles linked to epigenetic modifications. METHODS： Separate groups of cells were subjected to treatment of Condu-30, HC-30, and PI- 30 prepared by serial dilutions and succussions. Global microarray data recorded on Affymetrix platform, using 25-mer probes were provided by iLifeDiscoveries, India. Slides were scanned with 3000 7G microarray scanner and raw data sets were extracted from Cel （raw intensity） files. Analyses of global microarray data profile, differential gene expression, fold change and clusters were made using GeneSpring GX12.5 software and standard normalization procedure. Before microarray study, concentration of RNA （ng/IJL）, RIN value and rRNA ratio for all the samples were analysed by Agilant Bioanalyzer 2100. Reverse transcriptase polymerase chain reaction （RT-PCR） and quantitative RT- PCR were done for analyzing SMAD-4 expression. Fluorescence-activated cell sorting study was further made to elucidate fate of cells at divisional stages. Methylation-specific restriction enzyme assay was conducted for ascertaining methylation status of DNA at specific sites. RESULTS： HDs of HC-30 and Condu-30 differentially altered methylation in specific regions of DNA and expression profiles of certain genes linked to carcinogenesis, as compared to PI-30. Two separate cut sites were found in genomic DNA of untreated and placebo-treated HeLa cells when digested with McrBC, compared to a single cut observed in Condu-30-treated genomic DNA. SMAD-4 gene expression validated the expression pattern observed in microarray profile. Methylation-specific restriction enzyme assay elucidated differential epigenetic modifications in drug-treated and control cells. CONCLUSION： HDs triggered epigenetic modifications and alterations in microarray gene expression profiles of many genes associated with carcinogenesis in HeLa cells in vitro.展开更多
基金supported by grants from Scientific Research Foundation of Hubei Health Department (JX3B88)
文摘Objective： Colorectal cancer（CRC） is one of the most common types of human cancers. As a tumor suppressor, SMAD4 plays a key role in colorectal carcinogenesis and invasiveness. Copy number variations（CNVs） of the SMAD4 gene have been reported to be associated with cancer pathogenesis in array-based studies in different populations. Here we aimed to investigate the CNVs of the SMAD4 gene in a relatively large number of CRC patients from China. Methods： In the present study, we collected 147 Chinese CRC tumors as well as self-paired normal control tissues. Quantitative PCR was carried out to examine the copy number as well as the m RNA expression of the SMAD4 gene. Results： Our results showed that the copy number deletions of SMAD4 were frequent in a relatively high percentage of CRC samples（34.7%, 51 out of 147）. There was a positive correlation between the copy number decrease of SMAD4 and tumor progression in CRCs. Furthermore, copy number loss of SMAD4 was correlated with decreased m RNA expression.Conclusions： These findings suggested that the copy number deletions of SMAD4 were frequent in CRC patients from China and had the potential to serve as a diagnostic indicator, alone or in combination with other markers, for CRC.
基金financially supported by Boiron Laboratories,Lyon,FranceEmeritus Fellowship of UGC granted to ARKB
文摘OBJECTIVE： Methylation-specific epigenetic process and gene expression profiles of HeLa cells treated with ultra-high dilutions （HDs） of two plant extracts, Hydrastis canadensis （HC-30） and Marsdenia condurango （Condu-30）, diluted 106o times, were analyzed against placebo 30C （PI-30） for alterations in gene profiles linked to epigenetic modifications. METHODS： Separate groups of cells were subjected to treatment of Condu-30, HC-30, and PI- 30 prepared by serial dilutions and succussions. Global microarray data recorded on Affymetrix platform, using 25-mer probes were provided by iLifeDiscoveries, India. Slides were scanned with 3000 7G microarray scanner and raw data sets were extracted from Cel （raw intensity） files. Analyses of global microarray data profile, differential gene expression, fold change and clusters were made using GeneSpring GX12.5 software and standard normalization procedure. Before microarray study, concentration of RNA （ng/IJL）, RIN value and rRNA ratio for all the samples were analysed by Agilant Bioanalyzer 2100. Reverse transcriptase polymerase chain reaction （RT-PCR） and quantitative RT- PCR were done for analyzing SMAD-4 expression. Fluorescence-activated cell sorting study was further made to elucidate fate of cells at divisional stages. Methylation-specific restriction enzyme assay was conducted for ascertaining methylation status of DNA at specific sites. RESULTS： HDs of HC-30 and Condu-30 differentially altered methylation in specific regions of DNA and expression profiles of certain genes linked to carcinogenesis, as compared to PI-30. Two separate cut sites were found in genomic DNA of untreated and placebo-treated HeLa cells when digested with McrBC, compared to a single cut observed in Condu-30-treated genomic DNA. SMAD-4 gene expression validated the expression pattern observed in microarray profile. Methylation-specific restriction enzyme assay elucidated differential epigenetic modifications in drug-treated and control cells. CONCLUSION： HDs triggered epigenetic modifications and alterations in microarray gene expression profiles of many genes associated with carcinogenesis in HeLa cells in vitro.
