The inhibition of heme oxygenase-1 enhances the chemosensitivity and suppresses the proliferation of pancreatic cancer cells through the SHH signaling pathway.

Pancreatic cancer (PC) is a type of cancer associated with a high fatality rate due to a poor prognosis and resistance to treatment. Heme oxygenase-1 (HO-1) is significantly overexpressed in a number of types of cancer and seems to play an important role in cancer progression. In this study, we examined the potential effects of HO-1 on PC cell proliferation and sensivity to gemcitabine (Gem). Furthermore, the role of the sonic hedgehog (SHH) signaling pathway in the regulatory effects of HO-1 on PC progression were examined. For this purpose, the expression of HO-1 was examined in cultured PC cells by real-time PCR, western blot analysis and immunofluorescence. Transfection with small interfering RNA against HO-1 or an overexpression plasmid were used to regulate the expression of HO-1 in the MIA PaCa-2 and PANC-1 cell lines. Cell proliferation was examined by MTT assays in response to the different treatments. The results revealed that HO-1 expression differed significantly in the different PC cells. The overexpression of HO-1 induced PC cell proliferation and the inhibition of HO-1 decreased the cell proliferative ability. Furthermore, HO-1 activated the SHH signaling pathway in the PC cells. In addition, the SHH signaling pathway was found to play a role in HO-1-induced PC cell proliferation. The inhibition of HO-1 enhanced the responsiveness of PC cells to Gem and Gem was found to regulate the expression of HO-1 and the activation of the SHH pathway. On the whole, our findings indicate that HO-1 overexpression in PC cells may be responsible for the increased cell proliferation and the resistance to anticancer therapy. Furthermore, the SHH signaling pathway, the activation of which was initiated by HO-1, may be one of the endogenous mechanisms in this process. Our data shed light into the association between HO-1 and SHH in PC cells, and may aid in the development of novel therapeutic targets for the treatment of patients with PC.