Inhibition of Gemcitabine-Induced Autophagy in Cancer-Associated Fibroblasts Reduces Collagen I and Enhances Chemotherapeutic Efficacy in Pancreatic Cancer.

In pancreatic cancer, increased collagen I impairs the efficacy of gemcitabine; however, the role of gemcitabine itself in collagen I accumulation remains unclear. This study aims to explore the mechanism of gemcitabine-induced fibrosis and provide new insights to enhance its therapeutic efficacy. We analyzed COL1A1 expression in pancreatic cancer patient tumor tissues and found that gemcitabine treatment upregulated COL1A1 expression. Subsequently, cancer-associated fibroblasts (CAFs) were modeled by inducing human adipose-derived mesenchymal stem cells with tumor-derived exosomes. Using the autophagy inhibitor chloroquine (CQ) and the protein kinase B (AKT) activator SC79, we demonstrated that gemcitabine downregulated P62 expression and upregulated LC3BII, Beclin-1 expression, inducing autophagy in CAFs via decreasing AKT phosphorylation, which further led to collagen I accumulation. In addition, gemcitabine combined with CQ enhanced cell death in both CAFs and tumor cells, while inhibiting tumor cell proliferation and migration. In animal models, this combination therapy reduced gemcitabine-induced autophagy and collagen I deposition, contributing to delayed tumor growth. Collectively, gemcitabine upregulates collagen I by inducing CAF autophagy via reducing AKT phosphorylation. Targeting CAF autophagy can reduce collagen deposition, offering a promising strategy to improve the therapeutic efficacy of gemcitabine in pancreatic cancer.