Human DNA contains sequences homologous to the 5'-non-coding region of hepatits C virus: characterization with restriction endonucleases reveals individual varieties / 中华医学杂志(英文版)

ABSTRACT

<p><b>OBJECTIVE</b>To investigate a 272 base pair section of the 5'-non-coding region of genomic DNA from the peripheral blood monounuclear cells of healthy hepatitis virus C (HCV)-negative human subjects (not patients).</p><p><b>METHODS</b>This sequence section bears interest because (1) it harbors several potential methylation (Cp-rich) sites, and (2) it represents the largest part of its internal ribosomal entry site. A pre-PCR digestion protocol was established making consistent use of four restriction endonucleases selected for certain features SmaI, XmaCI, MspI, and HpaII are inhibited if methylation(s) are present at certain cytosines within their cutting sequences.</p><p><b>RESULTS</b>The suspected HCV-specific sequence was found in the DNA of each subject tested. The pre-PCR digestion assay reveals individual differences in their pattern of methylation, which may be due to possible epigenetic phenomena.</p><p><b>CONCLUSIONS</b>The results provide formal proof that these HCV-specific sequences are contained in the genomic or extra chromosomal target DNA, and probably belong to a new class of endogenous sequences.</p>