Conophylline effect on CAFs in HCC

Hepatocellular carcinoma (HCC) is a malignancy that is challenging to treat. Cancer-associated fibroblasts (CAFs) are reported to promote the malignant behavior of HCC cells via cytokines. Conophylline (CnP) has been reported to suppress activated hepatic stellate cells in liver fibrosis. We aimed to determine whether CnP is useful in suppressing tumor growth in HCC. We investigated whether CnP could suppress the HCC-promoting effect of CAFs derived from HCC tissues in vitro and in vivo. CAFs promoted the proliferation and invasion of HCC cells. CnP suppressed activated CAFs expressing α-smooth muscle actin (αSMA) and inhibited the HCC-promoting effects of CAFs. CnP significantly reduced the levels of cancer-promoting cytokines such as interleukin (IL)-6 (IL-6), IL-8, C-C Motif Chemokine Ligand 2 (CCL2), angiogenin, and osteopontin, which are secreted by CAFs. An in vivo study demonstrated that combined therapy with CnP and sorafenib against CAFs and HCC cells showed the strongest inhibition of tumor growth compared with the control and single treatment groups. Transcriptome analysis revealed that GPR68 in CAFs was strongly suppressed by CnP. The cancer-promoting effects of cytokines were eliminated by knockdown of GPR68 in CAFs. CnP inhibited the HCC-promoting effect of CAFs by suppression a number of HCC-promoting cytokines, which are secreted from CAFs expressing GPR68. Combination therapy with CnP and existing anti-cancer agents may be a promising therapeutic strategy in overcoming refractory HCC with activated CAFs. Evaluation of conophylline effect on CAFs in HCC cells using transcriptome analysis