Canonical Transient Receptor Potential 6 Is Present In Primary Hepatocellular Carcinoma And Is Implicated In Its Cell Proliferation

Transient recepter potential (TRP) is a kind of novel Ca2+-permeant channel, and is one of the hot topics in the current basic science research. The reseaches on TRP were mostly focused on nervous system at before, and now they come to extend to other areas. We hypothesized that TRP channels should be likely related to tumor, particularly tumor cell proliferation. They should be present in hepatocellular carcinoma(HCC) tissues and be implicated in the proliferation of HCC cells. To confirm this hypothesis, at first we used RT-PCR, western blot and immunohistochemistry to examine the expression levels of TRP channels in HCC tissues, and then compared these levels with those in the matching non-tumor (NT) liver tissues. Secondly, after inhibiting the function of TRPC channels by pharmacological means(SKF-96365) and RNAi, we observed the effect of this inhibition on cell proliferation in vitro. From the effects we found that TRPC6 channel was indeed present in HCC tissues; the mRNA of TRPC6 channels expressed in HCC tissues was at a higher level than that in matching NT liver tissues, whereas no TRPC6 protein expression increases were identified in HCC tissues as compared with related NT tissues; after inhibition of TRP channels by SKF-96365 and RNAi, the proliferation of two HCC cell lines——HepG2 and SMMC-7721 was significantly repressed, which confirmed that TRPC6 channels were implicated in HCC cell proliferation. Our study not only provides new insights into proliferation of HCC cells and subsequent cancer intervention strategies, but also opens a new area for TRP channel study.