Abstract
Background
Sunitinib is an important therapeutic option for renal cell carcinoma (RCC), but reduced response to sunitinib still limits its clinical benefit. This study explored the mechanism underlying reduced sunitinib sensitivity in RCC and aimed to identify potential strategies to improve sunitinib response.Methods
RCC organoids were established and characterized, and sunitinib-responsive genes were screened by transcriptomic analysis. Public datasets and clinical RCC samples were used to evaluate the clinical relevance of ALDH1L2. ALDH1L2 overexpression and knockdown were performed in RCC organoids to examine its effects on sunitinib sensitivity and ferroptosis-related changes. Organoid-derived xenograft models were used for in vivo validation. Molecular docking, cytotoxicity assays, CETSA, SPR, and functional experiments were used to screen and validate candidate compounds targeting ALDH1L2.Results
Sunitinib inhibited RCC organoid growth, with IC50 values of approximately 8 μM. Transcriptomic analysis showed that ALDH1L2 was upregulated after sunitinib treatment. Clinical analyses indicated that ALDH1L2 was highly expressed in RCC tissues and was associated with poorer survival and advanced stage. In RCC organoids, ALDH1L2 overexpression attenuated sunitinib-induced ROS accumulation and ferroptosis-related changes, as reflected by changes in GPX4, SLC7A11, GSH/GSSG, NADP+ /NADPH, Fe2 +, and MDA. In contrast, ALDH1L2 knockdown enhanced these changes and increased the sensitivity of RCC organoids to sunitinib. In organoid-derived xenograft models, ALDH1L2 overexpression reduced the antitumor effect of sunitinib and decreased tumor ROS accumulation. Erastin counteracted the protective effect of ALDH1L2 overexpression. Hederacolchiside A1 (HA-1) was identified as a candidate compound targeting ALDH1L2. HA-1 reduced ALDH1L2 protein abundance, altered its thermal stability, enhanced the inhibitory effect of sunitinib, and counteracted ALDH1L2-mediated sunitinib tolerance in RCC organoids.Conclusions
These findings suggest that ALDH1L2 contributes to reduced sunitinib sensitivity in RCC organoids by attenuating ferroptosis-related responses. HA-1 may improve the response of RCC organoids to sunitinib by targeting ALDH1L2, supporting further evaluation of this combination strategy.