Signaling pathways involved in pancreatic stellate cells activity and interaction with pancreatic cancer cells

Background. The activation, proliferation and migration capabilities of stellate pancreatocytes are guaranteed by a number of signaling molecular mechanisms that support the interaction of tumor cells with the PSC and determine the neoplastic process. Objective The review is a continuation of aт articles series devoted to the modern understanding of the role and functions of stellate pancreatocytes, namely, their involvement in interaction with cancer cells and signaling molecular pathways that provide synergism of the stellate pancreatocyte-cancer cell system. Methods. Data processing was carried out by the method of complex material analysis. Results. The Нedgehog signaling pathway provides interaction between PSC and tumor cells, which involves the leading mediator of this pathway - sHH (sonic hedgehog), the overexpression of which is recorded in the tumor tissue of the pancreas and ensures the formation of the tumor stroma. Stellate pancreatocytes also trigger the HGF / c-Met / survivin signaling pathway for invasion and metastasis. The activation of the PSCs themselves may be mediated by serotonin via the RhoA / ROCK signaling pathway. While the proliferation and migration of these cells, activated by alcohol, HNE (human neutrophil elastase), PDGF, IL-33 PSC are regulated by the MAP kinase and PI3K pathways. The Wnt signaling pathway promotes collagen accumulation. Through the AMPK / mTOR pathway, factor FTY720 induces apoptosis and inhibits the autophagy of stellate pancreatocytes. The interaction of PSC and tumor cells is also mediated through Notch and TGF-β, and through the Hippo signaling pathway with the participation of YAP / TAZ factors, it is possible to suppress the fibrotic activity of PSC. The interaction of stellate pancreatocytes and tumor cells is reflected in a direct correlation between a decrease in autophagy and apoptosis of stellate pancreatocytes and suppression of invasion and migration of tumor cells. This interaction can be mediated by ERK1 / 2 kinase. Among the factors secreted by tumor cells and causing PSC activation are: growth factor β1 (TGF-β1), PAI-1 protein, translation initiation factor 4E (eIF4E), sHH (involving PSC in pain deployment), Exo-Pan and Exo-Mia exosomes (engaging PSCs in carcinogenesis). Deactivation is mediated by colony stimulating factor 1 (CSF1R, cytokine). In turn, stellate pancreatocytes secrete the chemokine CXCL1, which stimulates the migration and invasion of tumor cells, exosomes with multiple miRNAs, which stimulate the proliferation and migration of cancer cells. Сonclusion. The activation of stellate pancreatocytes, which is necessary for the implementation of their fibrotic functions, is mediated through the RhoA / ROCK signaling pathway via serotonin. The Hippo pathway (activation) and AMPK / mTOR (suppression of autophagy and activation of apoptosis) are also involved in the regulation of the activity of stellate pancreatocytes. The interaction between the tumor cell and stellate pancreatocyte occurs through the Hedgehog, Notch, and TGF-β signaling pathways; regulation of invasion and metastasis of cancer cells provides the HGF / c-Met / survivin signaling pathway.