Integrated WGCNA, Network Pharmacology, and UPLC-MS/MS Profiling for Investigating the Antitumor Effects of the Kansui Radix Dichloromethane Fraction Against Renal Cell Carcinoma with Experimental Validation

Kansui Radix, the root of Euphorbia kansui, was first described in Shen Nong Ben Cao Jing as a traditional Chinese medicine, known for its effects of expelling water, reducing edema, and dissipating masses. It is traditionally indicated for conditions such as “watery accumulation” and “abdominal masses (zheng-jia)”, which share certain similarities with the clinical manifestations of renal cell carcinoma (RCC), including renal masses, edema, and body cavity effusion. Despite the recognized antitumor effects of Kansui Radix, the pharmacological basis and specific molecular mechanisms underlying its inhibition of RCC progression remain unclear. The goal of this study was therefore to evaluate the antitumor efficacy of Kansui-DCM in RCC and to explore its potential mechanism. To this end, the chemical composition of the dichloromethane fraction of Kansui Radix (Kansui-DCM) was characterized by UPLC-MS. The antiproliferative effects of Kansui-DCM on 786-O and RENCA cells were evaluated using the CCK-8 assay. Apoptotic morphology, apoptosis rate, cell migration and invasion abilities were assessed. An RCC mouse model was established, and tumor growth and histopathological staining were evaluated after drug administration. Immunohistochemistry, transcriptomic analysis, WGCNA (weighted gene co-expression network analysis), network pharmacology, and immunofluorescence were employed to investigate the molecular pathway. Protein and gene expression were analyzed by Western blot and qRT-PCR, respectively. Finally, the interactions between the active components and key targets were substantiated through molecular docking and molecular dynamics simulations. A total of 1397 compounds were detected in Kansui-DCM by UPLC-MS. In vitro experiments demonstrated that Kansui-DCM inhibited the proliferation of 786-O and RENCA cells in a dose-dependent manner, induced apoptosis, and suppressed cell invasion and migration in RENCA cells. Treatment with Kansui-DCM markedly suppressed tumor growth in vivo, as reflected by a reduction in tumor volume. Immunohistochemical analysis indicated that the expression levels of CD31, COX-2, and Ki67 were markedly decreased, while the expression level of CD8 was significantly increased. Integrated analysis using WGCNA and network pharmacology predicted that Kansui-DCM may exert its effects through the regulation of the HIF/VEGF signaling pathway, which was further validated by immunofluorescence, Western blot, and qRT-PCR assays. Molecular docking and molecular dynamics simulations demonstrated stable interactions between multiple active components of Kansui-DCM and key targets such as VEGFR2 and HIF-2α. In conclusion, these findings suggested that Kansui-DCM exerts anti-RCC effects associated with regulation of the HIF/VEGF pathway.