Objective To determine whether Rb gene is involved in the genesis of primary hepatocellular carcinoma(HCC). MethodsForty paraffin specimens of primary HCCs with corresponding adjacent liver tissues and normal liver tissues were investigated for Rb protein expression by tissue chip and SP immunohistochemical technique. ResultsLoss of Rb protein expression occurred in 17 of 40 tumor samples, whereas in 4 of 40 adjacent liver tissue samples, only 1 of 40 normal liver tissue specimens showed negative Rb staining.Rb protein deletion in HCC was higher than that in adjacent tissues and normal liver tissues (P＜0.05).Rb protein deletion rate doesn’t correlated remarkably with tumor size or phathology grade of HCC （Pgt;0.05）. ConclusionRb protein deletion may play an important role in the tumorigenesis of HCC.Tissue chip is an effective highthroughput technique platform for the study of tumor molecular pathology.
OBJECTIVE:The hereditary form of retinoblastoma(RB)is a monogenic disorder which is due to germinal mutation of RB susceptibility gene located on 13q14.The majority of hereditary RB cases transmit as a Mendelian autosomal dominant inheritance that 50% of the offspring of a carrier will inherit the disorder susceptibility gene and all carriers will develop the disorder.The authors report 3 hereditary RB families with incompleted penetrance and irregular transmission of RB phenotype. METHOD:RFLPsamp;VNTRs for analysis of haplotype and SSCPamp;direct DNA sequencing for determination of RB point mutation. RESULTS:The mosaicism of Rb gene point mutation resulted in the incompleted penetrance and irregular transmission of RB phentype. CONCLUSION:DAN-based diagnosis can be used to differentiate the hereditary and nonhereditary forms of retinblastoma but only is the direct detection of disease-causing mutation reliable for determnation of carrier and estimation of th e risk for retinoblastoma. （Chin J Ocul Fundus Dis,1996,12: 37- 40）
The Chinese human hepatocellular carcinoma cell SMMC7721 has been analysed by flow cytometry, Southern blotting and Western blotting. The results indicated that SMMC7721 cell is a hypoploid cell with a 0.81 DNA index, and that SMMC7721 cell has internal deletion in the 5'-end of its Rb gene and has no Rb gene product (Rb protein). The normal Rb cDNA has been inserted into a retrovirus vector DOL and introduced into SMMC7721 cells by electrporation transfection technique.About 75% of transfected SMMC7721 cells have been killed by Rb gene product. The remain 25% cells are alive as exogenous Rb gene has been mutationally inactivated. （Chin J Ocul Fundus Dis,1994,10:21-24）
The human wild-type Rb cDNA has been inserted into a retrovirus vector DOL and introduced into the human breast cancer cell MDAMB468,which has a large deletion of exons 3-27 of Rb genes,by electroporation transfection techniques.The exogenous Rb gene expresses the 110kd Rb protein.The morphology of the transfected cells is similar to that of the parent MDAMB468 cells.With the expression of Rb protein,the growth rate of MDAMB468 cells decreases by about 50%,and the colony formation ability in soft agaris repressed completely.After injection of 3times;106Rb+ cells and Rb-MDAMB468 cells into nude mice,the tumors formed from 106Rb+ cells are smaller than those from Rb-cells.The cell population of G1 and S phase of Rb+ MDAMB468 cells increases and the proliferation quotient decreases by about 50%.This result supports the former report the Rb protein. （Chin J Ocul Fundus Dis,1993,9:135-140）