Palbociclib suppresses the cancer stem cell properties and cell proliferation through increased levels of miR-506 or miR-150 in Panc-1 and MiaPaCa-2 cells

The prognostic characteristics of pancreatic cancer (PC) are determined by the contributing factors from the tumor microenvironment. Leptin is a critical oncogenic factor released by adipocytes as an adipokine into the tumor microenvironment, where it promotes tumor development by activating cancer stem cell (CSC) molecular regulators Notch, Hedgehog, and Wnt/(3-catenin signaling. One of the downstream targets of these pathways is CDK4/6 and cyclin D which is controlled by P16 INK4A that is highly mutated in PC. Therefore, the purpose of this study was to determine the effect of a CDK4/6 inhibitor, palbociclib, on Leptin-induced PC cells and to target the Notch, Hedgehog, and Wnt/(3-catenin signaling pathways via miR-150, miR-506, and miR-208 modulation. Leptin treatment increased the ability of Panc-1, MiaPaCa-2, and Capan-2 cells to proliferate and decreased the effect of palbociclib. Additionally, tumorspheres were generated from Leptin-treated (Leptin+) and Leptin-untreated (Leptin-) Panc-1 and MiaPaCa-2 cells and transfected with miR-506, miR-150 (tumorsuppressor miRNAs), or anti-miR-208 (oncomiR), followed by palbociclib treatment. Forced expression of miR-506 or miR-150 significantly increased the susceptibility of Leptin+ cells to palbociclib treatment by inhibiting colony and tumor spheroid formation, and CD44 expression in Panc-1 and MiaPaCa-2 cells. Additionally, the increased miR-150 expression is more effective at inhibiting N-cadherin, (3-catenin, p-GSK3(3, Notch, and Wnt5a/b expression in Leptin-/+ Panc-1 and MiaPaCa-2 cells. As a result, palbociclib suppressed the CSC profile induced by leptin treatment, inhibiting both tumorsphere forms and leptin-targeted signaling pathways, thereby disabling the Panc-1 and MiaPaCa-2 cells??? resistance mechanism. Increased expression of miR-506 or miR-150 and inhibition of miR-208 enhanced sensitivity of Panc-1 and MiaPaCa-2 Leptin-/+ cells to palbociclib treatment. As a result, this study proved that combining inhibitors of CSC molecular regulators with palbociclib improves the success rate of inhibition of PC cell proliferation.

Automated summary

This study demonstrates that combining CSC molecular regulators with palbociclib can improve the success rate of inhibiting pancreatic cancer cell proliferation.