Simultaneous Targeting of Multiple Hallmarks of Cancer With Recombinant Methioninase, Rapamycin and Chloroquine Is Specific and Synergistic to MiaPaCa-2 Pancreatic-Cancer Cells in Contrast to Hs-27 Normal Fibroblasts

Background/aim: Pancreatic ductal adenocarcinoma (PDAC) is recalcitrant to conventional therapies. Recombinant methioninase (rMETase), rapamycin, and chloroquine target fundamental hallmarks of Cancer. The present study examined the efficacy of each agent alone and in all combinations against PDAC cells compared to normal fibroblasts.

Materials and methods: The 30% inhibitory concentration (IC₃₀) of rMETase, rapamycin, and chloroquine on MiaPaCa-2 PDAC cells and Hs-27 normal human fibroblasts was determined with in vitro cell-viability assays using the WST-8 reagent. Combination treatment was performed at IC₃₀ concentrations for MiaPaCa-2 cells to evaluate synergistic efficacy of all combinations of rMETase, rapamycin, and chloroquine on each cell type.

Results: rMETase alone led to significantly higher cytotoxicity against MiaPaCa-2 cells than Hs-27 fibroblasts (p<0.05). The triple combination of rMETase, rapamycin and chloroquine synergistically eradicated MiaPaCa-2 cells, reducing viability to 3.8% (p<0.05). In contrast, normal Hs-27 fibroblasts were not synergistically inhibited by the triple combination.

Conclusion: The combination of rMETase, rapamycin and chloroquine had highly synergistic and selective efficacy against PDAC cells in vitro compared to normal cells, supporting its potential as a precision-targeted metabolic clinical therapy for pancreatic Cancer.

CQ; Hoffman effect; Pancreatic cancer; RAPA; chloroquine; combination therapy; methionine addiction; rMETase; rapamycin; recombinant methioninase; synergy.