Dataset Information

Prognostic value of loss of heterozygosity and sub-cellular localization of SMAD4 varies with tumor stage in colorectal cancer.

ABSTRACT: BACKGROUND:Although loss of heterozygosity (LOH) at chromosome location 18q21 and decreased expression of SMAD4 in invasive colorectal cancers (CRCs) correlate with poor patient survival, the prognostic value of LOH at 18q21 and sub-cellular localization of SMAD4 have not been evaluated in relation to tumor stage. METHODS:Genomic DNA samples from 209 formalin-fixed, paraffin-embedded sporadic CRC tissues and their matching controls were analyzed for 18q21 LOH, and corresponding tissue sections were evaluated by immunohistochemistry for expression of SMAD4 and assessed for its sub-cellular localization (nuclear vs. cytoplasmic). In addition, 53 frozen CRCs and their matching control tissues were analyzed for their mutational status and mRNA expression of SMAD4. The phenotypic expression pattern and LOH status were evaluated for correlation with patient survival by the use of Kaplan-Meier and Cox regression models. RESULTS:LOH of 18q21 was detected in 61% of the informative cases. In 8% of the cases, missense point mutations were detected in Smad4. In CRCs, relative to controls, there was increased SMAD4 staining in the cytoplasm (74%) and decreased staining in the nuclei (37%). LOH of 18q21 and high cytoplasmic localization of SMAD4 were associated with shortened overall survival of Stage II patients, whereas low nuclear expression of SMAD4 was associated with worse survival, but only for patients with Stage III CRCs. CONCLUSIONS:LOH of 18q21 and high cytoplasmic localization of SMAD4 in Stage II CRCs and low nuclear SMAD4 in Stage III CRCs are predictors of shortened patient survival.

SUBMITTER: Jia X

PROVIDER: S-EPMC5386755 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature

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Prognostic value of loss of heterozygosity and sub-cellular localization of SMAD4 varies with tumor stage in colorectal cancer.

Jia Xu X Shanmugam Chandrakumar C Paluri Ravi K RK Jhala Nirag C NC Behring Michael P MP Katkoori Venkat R VR Sugandha Shajan P SP Bae Sejong S Samuel Temesgen T Manne Upender U

Oncotarget 20170301 12

<h4>Background</h4>Although loss of heterozygosity (LOH) at chromosome location 18q21 and decreased expression of SMAD4 in invasive colorectal cancers (CRCs) correlate with poor patient survival, the prognostic value of LOH at 18q21 and sub-cellular localization of SMAD4 have not been evaluated in relation to tumor stage.<h4>Methods</h4>Genomic DNA samples from 209 formalin-fixed, paraffin-embedded sporadic CRC tissues and their matching controls were analyzed for 18q21 LOH, and corresponding ti ...[more]

PMID: 28423626

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Project description:Colorectal cancer (CRC) ranks as the second leading cause of cancer-related mortality globally and is the third most prevalent cancer. The effective treatment of CRC is challenged by tumor drug resistance, underscoring the urgent need for novel therapeutic strategies. It is well recognized that epigenetic modifications, particularly DNA methylation, significantly contribute to the initiation and advancement of CRC. Tumors frequently exhibit hypermethylation of specific gene promoters alongside a general hypomethylation of genomic DNA. In normal tissues, gene promoters, particularly those of tumor suppressor genes, are typically unmethylated, whereas they are often hypermethylated in cancerous tissues. Previous studies have identified the methylation status of the CpG island within the SLC30A10 gene as a reliable biomarker for CRC. Notably, a hypermethylated phenotype is inversely correlated with SLC30A10 expression. However, the precise functional implications of SLC30A10 suppression in the context of CRC progression remain to be elucidated.). The investigation of molecular pathways involved in metal metabolism in CRC has not been conducted previously at the transcriptomic level. Furthermore, the relationship between the mutational characteristics of tumors—such as individual mutations, mutational burden, and microsatellite instability—and the activity of genes related to metal metabolic pathways has not been explored. This project aims to be the first to examine the antitumor potential of modulating the transport systems for manganese and zinc ions in CRC. The molecular function of SLC30A10 is to export zinc (Zn) and manganese (Mn) ions from the cell. Additionally, SLC30A10 plays a crucial role in mitigating Mn-induced cytotoxicity and facilitates Zn transport to early endosomes while promoting endosomal recirculation to avert Zn toxicity. Our findings indicate that overexpression of SLC30A10 is correlated with the knockout of its functional antagonist, SLC39A14 in the HuTu80 and HCT-15 cell lines.

Dataset Information

Prognostic value of loss of heterozygosity and sub-cellular localization of SMAD4 varies with tumor stage in colorectal cancer.

Publications

Prognostic value of loss of heterozygosity and sub-cellular localization of SMAD4 varies with tumor stage in colorectal cancer.

Similar Datasets

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