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13:19
Microarray-based Identification of Individual HERV Loci Expression: Application to Biomarker Discovery in Prostate Cancer
Published on: November 2, 2013
Expression patterns of non-coding spliced transcripts from human endogenous retrovirus HERV-H elements in colon
Qiaoyi Liang1, Zefeng Xu, Rongzhen Xu
1Cancer Institute, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
Plos One
|January 13, 2012
Summary
Human endogenous retrovirus-H (HERV-H) spliced transcripts show varied expression in colon cancer cell lines and tissues. Demethylation impacts HERV-H activity, with more active loci found in tumors than normal tissue.
Area of Science:
- Genomics
- Molecular Biology
- Cancer Research
Background:
- The human endogenous retrovirus-H (HERV-H) family is the most abundant HERV, with its env-related transcripts linked to colon cancer.
- The expression patterns of HERV-H spliced non-coding transcripts in colon cancer remain largely uncharacterized.
Purpose of the Study:
- To investigate the expression characteristics of HERV-H spliced non-coding transcripts in colon cancer.
- To determine if HERV-H expression patterns differ between colon cancer cell lines and tissues.
- To explore the influence of genomic DNA methylation on HERV-H expression in colon cancer.
Main Methods:
- Utilized RT-PCR with specific primers targeting the tRNA(His) primer-binding site and R region of the 3' LTR of HERV-H.
- Cloned and sequenced PCR amplicons to identify expressed HERV-H transcripts.
- Assigned sequences to individual HERV-H loci using nucleotide differences.
- Analyzed expression in colon cancer cell lines (HT29, LS 174T, RKO, SW480, SW620) and tumor vs. adjacent normal tissues.
- Investigated the effect of demethylation treatment on HERV-H expression in SW480 and RKO cell lines.
Main Results:
- Identified distinct expression patterns of HERV-H spliced transcripts from various active elements across different colon cancer cell lines.
- Observed significant alterations in HERV-H expression patterns in SW480 and RKO cells following demethylation treatment.
- Found a higher number of transcriptionally active HERV-H loci in colon tumor tissues compared to adjacent normal tissues (14 vs. 7).
Conclusions:
- This study provides the first characterization of non-coding spliced HERV-H transcript expression in colon cancer.
- HERV-H spliced transcript expression patterns are heterogeneous among colon cancer cell lines and can be modulated by DNA methylation levels.
- Beyond general up-regulation, colon tumors exhibit a greater number of active HERV-H loci compared to normal adjacent tissues.
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