Published online Feb 21, 2007. doi: 10.3748/wjg.v13.i7.1010
Revised: December 28, 2006
Accepted: January 23, 2006
Published online: February 21, 2007
AIM: To elucidate the role of Rab23 in hepatocellular carcinoma (HCC) by assessing the expression of Rab23 in HCC tissue and in HCC cell lines.
METHODS: Primary tumors (n = 100) were stained with Rab23 antibodies using immunohistochemistry and in situ hybridization in tissue microarrays. Relationships between gene expression and pathology parameters were analysed. The biological significance of Rab23 in Hep-3B cells was examined by knocking down Rab23 gene expression. We designed a pair of double-stranded RNAs against human rab23 and transfected siRNA into Hep-3B cells. Rab23 expression in these cells was examined using RT-PCR and Western blots. We investigated cell growth by MTT assays and fluorescence-activated cell sorting.
RESULTS: High cytoplasmic and nuclear expression of Rab23 was found in 38 of 71 (53.5%) and in 49 of 68 HCC patients (72%) respectively, which correlated with tumor size. HCC cell lines expressed Rab23. In Hep3B cells, siRNA for Rab23 decreased Rab23 mRNA by 4.5-fold and protein expression by 2-fold. Survival rates at 24 and 48 h for Hep-3B cells transfected with siRNA were lower and about 30% Hep-3B cells were apoptotic. Knocking down rab23 suppressed Hep3B cell growth, suggesting that rab23 could play an important role in Hep3B cell growth.
CONCLUSION: Rab23 is overexpressed and/or activated in HCC. Rab23 may be both a HCC predictor and a target for treating HCC.