Detection of Human Endogenous Retrovirus K (HERV-K) Transcripts in Human Prostate Cancer Cell Lines.
Detection of Human Endogenous Retrovirus K (HERV-K) Transcripts in Human Prostate Cancer Cell Lines.
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DOI：
10.3389/fonc.2013.00180
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发表时间：
2013
影响因子：
4.7
通讯作者：
Lenz J
中科院分区：
文献类型：
--
作者：
Agoni L;Guha C;Lenz J
人类内源性逆转录病毒（HERV）在包括前列腺癌在内的许多癌症中转录。HML 2亚型的人内源性逆转录病毒K（HERV-K）是人类基因组中最近整合的和最完整的逆转录病毒，其中许多病毒基因组编码全长或部分长度的病毒蛋白。为了评估前列腺癌细胞系中HERV-K的转录物并鉴定人类基因组中转录的特异性HERV-K元件，进行了逆转录酶-PCR（RT-PCR）和cDNA测序。链特异性RT-PCR、质粒亚克隆和cDNA测序检测了四种前列腺细胞系（LNCaP、DU 145、PC 3和VCaP）中HERV-K（HML 2）编码链转录物的存在。跨剪接点的RT-PCR揭示了三个细胞系中env基因mRNA的剪接变体，其中两个涉及以前未描述的选择性剪接位点。为了确定产生转录物的HERV-K基因座，使用RepeatMasker编制了人类基因组中超过200个HERV-K内部基因组片段和超过1，000个HERV-K单独长末端重复（LTR）片段的列表。令人惊讶的是，从病毒基因组的内部位置鉴定的序列大多是较小的片段，而LTR相对完整。可能的原因进行了讨论。测试的细胞系中的转录物来自几个HERV-K基因座，其中在多个细胞系中检测到一些前病毒，而其他仅在所使用的四个细胞系中的一个中检测到。在一些情况下，还检测到来自病毒反义链的转录物。此外，检测到来自两条单独LTR链的转录物。这些数据表明，来自HERV-K基因座的转录物通常发生在前列腺癌细胞系中，并且可以发生任一链的转录。他们还强调了单核苷酸水平分析的重要性，以确定特定的，个别的HERV-K基因座的转录，并表明HERV-K在前列腺癌中的表达值得进一步研究。
Human endogenous retroviruses (HERVs) are transcribed in many cancers including prostate cancer. Human endogenous retrovirus K (HERV-K) of the HML2 subtype is the most recently integrated and most intact retrovirus in the human genome, with many of the viral genomes encoding full- or partial-length viral proteins. To assess transcripts of HERV-K in prostate cancer cell lines and identify the specific HERV-K elements in the human genome that are transcribed, reverse transcriptase-PCR (RT-PCR) and cDNA sequencing were undertaken. Strand-specific RT-PCR, plasmid subcloning, and cDNA sequencing detected the presence of HERV-K(HML2) coding strand transcripts within four prostate cell lines (LNCaP, DU145, PC3, and VCaP). RT-PCR across splice junctions revealed splicing variants for env gene mRNA in three cell lines, two involving previously undescribed alternative splice sites. To determine the HERV-K loci from which the transcripts arose, RepeatMasker was used to compile a list of over 200 HERV-K internal genome segment fragments and over 1,000 HERV-K solo long terminal repeat (LTR) fragments in the human genome. Surprisingly, the sequences identified from internal positions of the viral genome were mostly smaller segments, while the LTRs were relatively intact. Possible reasons for this are discussed. The transcripts in the cell lines tested, arose from several HERV-K loci, with some proviruses being detected in multiple cell lines and others in only one of the four used. In some instances, transcripts from viral antisense strands was also detected. In addition, transcripts from both strands of solo LTRs were detected. These data show that transcripts from HERV-K loci commonly occur in prostate cancer cell lines and that transcription of either strand can occur. They also emphasize the importance of single nucleotide level analysis to identify the specific, individual HERV-K loci that are transcribed, and indicate that HERV-K expression in prostate cancer warrants further study.