Background/aim: Oncolytic reovirus, which is a non-enveloped virus possessing a 10-segmented double-stranded RNA genome, has been anticipated as a novel class of antitumor agent. Hepatocellular carcinoma (HCC) is considered to be a target suitable for reovirus-mediated virotherapy. Transforming growth factor (TGF)-β plays an important role in the pathogenesis of HCC. TGF-β-signaling inhibitors have proceeded to clinical trials as potential antitumor agents for HCC. On the other hand, TGF-β is involved in induction of expression of cathepsins B and L, which are important for reovirus infection. It remains to be examined whether TGF-β signaling inhibitors affect reovirus-mediated lysis of HCC cells. The aim of this study was to evaluate the effects of TGF-β-signaling inhibitors on tumor cell lysis efficiency of reovirus in human HCC cells.
Materials and methods: Reovirus was added to four types of human HCC cell lines pretreated with one of three TGF-β type I receptor inhibitors: SB431542, A-83-01, or galunisertib (LY2157299). Cell viability, virus genome copy numbers, and virus protein expression were evaluated following reovirus infection.
Results: SB431542 significantly inhibited reovirus-mediated killing of human HCC cell lines, while A-83-01 and galunisertib did not inhibit.
Conclusion: These data indicate that SB431542 inhibited reovirus-mediated lysis of human HCC cells in a TGF-β signaling-independent manner.
Keywords: SB431542; TGF-β inhibitor; hepatocellular carcinoma; reovirus.
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