Integrated network pharmacology and RNA sequencing analysis to reveal the mechanisms of Qici Sanling decoction in the treatment of gemcitabine resistant bladder cancer

Bladder cancer (BCa) is the most prevalent cancer of the urinary system in adults; the prognosis is dismal for BCa treated with gemcitabine (GEM) owing to intrinsic or acquired chemoresistance. This study investigated the potential of Qici Sanling decoction (QCSL), an herbal Chinese medicine, to augment the efficacy of GEM in treating GEM-resistant BCa via network pharmacology and RNA sequencing. We screened 103 active components of QCSL and their 226 targets from the TCMSP database and identified 3985 targets of GEM-resistant BCa via transcriptome sequencing. On the basis of the 69 common targets, a proteinprotein interaction (PPI) network was constructed to identify the top 7 targets. Disease Ontology (DO), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analyses were conducted to uncover key pathways. CCK-8 assays, Western blotting, flow cytometry, colony formation, and EdU assays were used to assess the apoptosis and proliferation of GEM-resistant T24 and J82 cells treated with QCSL. The BCa gene set was among the top enriched gene sets in the DO analysis; GO analysis revealed enrichment of 2020 terms linked to GEM resistance, and KEGG analysis revealed 161 enriched signalling pathways. Molecular docking indicated that PTGS2 has high affinity for targets of QCSL components. In vitro experiments demonstrated that cells treated with both QCSL and GEM had significantly reduced viability, increased levels of apoptosis, and decreased proliferative capacity. Thus, QCSL enhances the therapeutic effects of GEM in BCa by promoting cell apoptosis and inhibiting cell proliferation. These findings have significant clinical implications, highlighting a potential combined treatment strategy for GEM-resistant BCa to improve patient outcomes.