Frequent down-regulation and deletion of KLF6 in primary hepatocellular carcinoma.

Kruppel-like factor 6 (KLF6) was reported as tumor suppressor in multiple cancers. However, loss of chromosomal locus spanning KLF6 is relatively infrequent in previous published studies. To explore the role of KLF6 in hepatocellular carcinoma (HCC), we examined the gene for expression change, loss of heterozygosity (LOH) and mutation in 26 HCC samples. The expression levels of KLF6 were significantly down-regulated in HCCs, as detected by qRT-PCR. LOH occurred in 11 (52%) of 21 tumors, and all the samples with LOH showed KLF6 down-regulation. The mutational frequency was 24%, and sequence changes located in activation domain of KLF6. Furthermore, MTT assay showed a significant antiproliferative effect of the wt KLF6 transfected in HepG2 hepatoblastoma cells. Fluorescence-activated cell sorting analysis revealed that KLF6 could induce apoptosis. These findings indicate that deregulation of KLF6, together with genetic abnormalities of allelic imbalance and mutations, may play a role in HCC pathogenesis.