[Features of micro satellite alterations on chromosome 4 in hepatocellular carcinoma]

To study the features of micro satellite alterations and their association with clinicopathological characteristics of hepatocellular carcinoma (HCC).

Ten high-polymorphic micro satellite markers on chromosome 4 were selected to be detected for loss of heterozygosity (LOH), micro satellite instability (MSI) and allelic imbalance (AI) in 56 HCC using PCR-simple sequence length polymorphism (PCR-SSLP) analysis.

LOH was found in 40 of 56 HCC (71.4%) on at least 1 locus, the top two loci were D4S426 (61%), D4S1534 (53.7%). LOH on D4S406 was significantly higher in cases with positive serum HBsAg than in those with negative HBsAg. Similarly, LOH on D4S1538 occurred more frequently in patients with HBsAg negative than those with HBsAg positive [76.9% (20/26) vs 12.5% (2/16), chi2=13.999, P<0.01]. LOH on D4S426, D4S1615 and D4S165 were more frequent in poorly or moderately differentiated HCC than in well-differentiated HCC [76.7%(23/30) vs 18.2%(2/11), chi2=9.242, P<0.01; 53.8% (14/26) vs 16.7% (2/12), P<0.05; 60.7% (17/28) vs 18.2% (2/11), P<0.01]. LOH on loci D4S2921 was more frequently detected in tumors with intrahepatic metastasis than in those without [63.6% (21/33) vs 18.2% (2/11), chi2=5.132, P<0.01]. MSI was found in 8.9% (5/56) cases. AI was found in 26.8% (15/56) of all cases examined.

Frequent micro satellite alterations on chromosome 4 were existed in HCC. LOH, which represents tumor suppressor gene pathway, plays a more important role in hepatocarcinogenesis of HCC; MSI, representing mismatch repair gene pathway, arranges as the next.