Low molecular weight heparin (LMWH) enhances immunotherapy (I) activity in pancreatic cancer cells.

Abstract

50 Background: The aim is to investigate the effect of LMWH in combination with chemotherapy (C) and I in PC. Methods: BxPC-3, PANC-1, MIA PACA-2 cell lines were exposed in Tinzaparin (T) (0.5, 0.7, 0.9 μΜ) and/or 1 μΜ Nab-Paclitaxel (A) and/or 1 μΜ Gemcitabine (G) and/or 1 μΜ Nivolumab (NI), 1 μΜ, Pembrolizumab (PE) and 1 μΜ ipilimumab (IPI). Protein levels of VEGFR2, p-ERK1/2, p-AKT detected by Western blotting. Cells viability was measured through MTT assay. Results: Increasing protein levels of VEGFR2 was observed in all PC cell lines exposed to a constant dose of T and/or A,G. NI and PE +/- with IPI increased VEGFR2. In NI/PE+IPI+T scheme VEGFR2 levels were decreased (0.1-0.7 folds) in a dose dependent way in mtKRAS cells (PANC1, MIAPACA2). C (G or A) + I decreased VEGFR2 protein levels in mtKRAS cells PANC1 (0.1-0.4 folds), MIAPACA2 (0.1-0.6 folds) in double scheme. T+G/A+NI/PE+IPI scheme increased VEGFR2 in all PC cells. PANC-1 cells were decreased 40% in 0,7T+IPI+(NI or PE) after 48hours. The effect of these schemes on signaling pathways (MEK/EKR, AKT/mTOR) and apoptosis was identified through pERK1/2, pAKT, PARP, cl. caspase-3. Conclusions: These results identify the different effect of I alone or in combination with T and C in PC cells bearing mutant or wild type KRAS. Double or triple combination reduced VEGFR2 protein levels in mtKRAS and not in wtKRAS PC cells. The 0,7T+IPI+(NI or PE) combination decreases cell viability of PC cells through apoptosis. Testing of the combinatorial scheme T+chemo+IPI+(NI or PE) with PANC-1 PC in scid mice is ongoing and will be presented. NC:not changed, -:<20% protein vs control, +:>20% protein vs control, ++:>40% protein vs control. [Table: see text]