[Detection of hepatitis C virus RNA in the tissue of hepatocellular carcinoma by multiple detection system].
OBJECTIVE
Detection of hepatic HCV RNA in hepatocellular carcinoma (HCC) is difficult, since its expression is very low. Several techniques have been established. However, false positive and negative rates still exist. In this study, we applied several conventional and recently developed detection systems to determine the exact effect of HCV RNA on the development of RCC.


METHODS
Immunohistochemistry for HCV core antigen and in situ hybridization for HCV RNA had been performed in 39 cases of HCC. IS-RT-PCR was applied for detection and localization of HCV RNA. We extracted microdissected liver tissues to detect HCV RNA separately in cancerous and pericancerous tissues so that the microscopic origin of the amplicons could be controlled. The serological tests including ELISA and RT-PCR for HCV also were performed in all cases.


RESULTS
The positive rate by ELISA (30.8%) was not always consistent with that by RT-PCR(43.6%)from serum samples. The latter was much more sensitive and accurate to reflect existence of HCV RNA. Immunohistochemistry showed expression of RCV core antigen in 15 of 39 HCC cases. In pericancerous tissues, the signals were mainly localized in the cytoplasm of hepatocytes. However, translocated expression of HCV core protein was observed in the nuclei of tumor cells, the translocated rate was 73.3%. According to IS-RT-PCR, the positive signals were located mainly in the cytoplasm of cancer cells, the positive rate in HCC was 53.8%, expression of HCV RNA, serum HCV RNA level was detected to be low or negative. This suggested that serum HCV RNA was not always a good reflection of hepatic HCV RNA in HCC tissues. The microdissection RT-PCR described here gave an equal positive rate (59.0%) of HCV RNA in cancerous and pericancerous tissues.


CONCLUSIONS
The high detection rate of HCV RNA in HCC specimens even from seronegative patients confirms the important role of HCV RNA during malignant transformation. IS-RT-PCR is a good detection and localization method to visualize HCV RNA in HCC tissues. The microdissection RT-PCR method has a distinct advantage and we anticipate this method will provide an important evidence to determine whether HCV play a direct or indirect role in hepatocarcinogenesis.
Li
L
L
Department of Pathology, Fourth Military Medical University, Xian 710032, China.
Wang
W
W
Yu
X
X
D000328:Adult; D006528:Carcinoma, Hepatocellular / Q000821:virology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D017403:In Situ Hybridization; D008113:Liver Neoplasms / Q000821:virology*; D008297:Male; D008875:Middle Aged; D012367:RNA, Viral / Q000032:analysis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014758:Viral Core Proteins / Q000032:analysis / Q000235:genetics*
D012367:RNA, Viral; D014758:Viral Core Proteins; C069130:nucleocapsid protein, Hepatitis C virus