High levels of BCL-2 messenger RNA detected by in situ hybridization in human hepatocellular and cholangiocellular carcinomas.
Immunocytochemistry has indicated that, in the liver, the bcl-2 gene is generally expressed in bile duct cells and tumors of biliary origin. Both in situ hybridization and immunocytochemistry were used to analyze the expression of bcl-2 messenger RNA (mRNA) and its protein product (Bcl-2) in the tissue of 50 pure primary liver tumor (PLT) specimens including 40 hepatocellular carcinoma (HCC) specimens and 10 cholangiocellular carcinoma (CC) specimens. The phenotype of the tumors expressing bcl-2 was confirmed by immunocytochemical assessment of the cytokeratin (CK) profile (CK8, CK18, CK7, and CK19). Whereas positive immunoreaction with the anti-Bcl-2 MoAb was revealed in only 8 (20%) of 40 HCC specimens and 1 (10%) of 10 CC specimens, high contents of bcl-2 mRNA were found in 26 (65%) of 40 HCC specimens and 9 (90%) of 10 CC specimens. Regarding the CK profile, only 25 (62%) of 40 HCC specimens showed pure hepatocytic lineage (CKs 8-18), whereas among the remaining 15 HCC specimens, positivity for either CK7 (12 specimens) or CK19 (5 specimens) was observed. All 10 CC specimens stained with CKs 8-18-19, and 8 of 10 stained with CK 7 as well. These results indicate that PLTs display a greater expression of bcl-2 mRNA than of the Bcl-2 protein. Furthermore, CK profile assessment confirmed that bcl-2 expression is not confined to liver tumors of biliary origin. In the absence of a well-demonstrated post-transcriptional control of the gene, the authors propose the detection of bcl-2 mRNA by in situ hybridization as a possible alternative method for assessing the expression of bcl-2 mRNA in PLT.
Fiorentino
M
M
Pathology Unit of the F. Addarii Institute of Oncology, Bologna University School of Medicine, Italy.
D'Errico
A
A
Altimari
A
A
Barozzi
C
C
Grigioni
W F
WF
D001650:Bile Duct Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D001653:Bile Ducts, Intrahepatic / Q000378:metabolism / Q000473:pathology; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D018281:Cholangiocarcinoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization / Q000379:methods; D007633:Keratins / Q000378:metabolism; D008113:Liver Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis*
D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D007633:Keratins