[Determination of expression of eight p53-related genes in hepatocellular carcinoma with tissue microarrays]
Ming-Hua Zhu1, Can-Rong Ni, Zhi Zhu
1Department of Pathology, Changhai Hospital, Second Military Medical University, Shanghai, 200433, PR China. mhzhu2000@hotmail.com
Background & Objective:
Hepatocarcinogenesis was a multistage process involving a number of genes. Molecular biological studies indicated that abnormal expression of p53 gene family is correlated with the development of hepatocellular carcinoma (HCC). This study was designed to investigate the expression difference and its clinicopathologic significance of eight kinds of p53-related oncogenes and tumor-suppressor genes in HCC and adjacent-tumor liver tissues using tissue microarray technique.
Methods:
The HCC tissue microarrays comprised 273 cases of HCC tissues, 144 adjacent-tumor liver tissues, and 10 normal liver tissues obtained from autopsy. The diameter of each specimen on tissue microarrays was 2.0 mm. Immunohistochemistry was employed to detect the expression of p16(INK4a), p21(WAF1), p33(ING1b), p53, p57(KIP2), p73, mdm2, and ATM genes in tumor and adjacent tumor liver tissue, respectively. The relationship between HBV infection rate and the expression of these genes was also analyzed.
Results:
Three paraffin-embedded HCC tissue microarrays were successfully constructed, composed of 136, 143, and 148 tissue dots, respectively. The positive staining rates of these eight genes in HCC and surrounding-tumor tissues were: (p16(INK4a)) 35.9% and 9.0%, (p21(WAF1)) 41.8% and 11.1%, (p33(ING1b)) 43.65% and 14.6%, (p53) 46.2% and 12.5%, (p57(KIP2)) 39.2% and 16.7%, (p73) 9.5% and 2.8%, (mdm2) 41.4% and 9.0%, (ATM) 6.6% and 1.4%, respectively. The expression of all these genes in HCC were stronger than that in the surrounding-tumor liver tissues (P< 0.05). The expression differences of these genes in HCC tissues with varied differentiated grades were not significant(P >0.05). Except p16(INK4a), p21(WAF1), and p73 genes(P >0.05), the expression of p33(ING1b), p53, mdm2, ATM, and p57(KIP2) genes in HCC with portal vein invasion were higher than those in HCC without portal vein invasion (p33(ING1b), p53, mdm2, ATM, P< 0.01; p57(KIP2), P< 0.05). The infection rate of HBV did not have a significant correlation to the expression of these eight genes (P >0.05).
Conclusion:
Tissue microarray technique had the advantage of high-throughput in the detection of HCC-related oncogenes and tumor-suppressor genes, which can analyze larger amounts of specimens, more target genes, and cost less working time.
