Study on the effect of tumor-derived fibroblast exosomal lncRNA HOTAIR on the proliferation of bladder cancer cells and its mechanism of action.

Collect CAFs to extract and identify exosomes from the culture supernatant. Use exosome groups to intervene in bladder cancer cell lines. Validate the RNA expression levels of HOTAIR and miR-130a-3p through qRT-PCR, and detect the expression of epithelial-mesenchymal transition (EMT) related proteins using Western blot and immunofluorescence imaging. Verify the changes in proliferation and invasion abilities of bladder cells in each group using CCK8, scratch assays, and Transwell methods. Evaluate the effects of exosomes on tumor proliferation and metastasis in a subcutaneous tumor model in nude mice.

Morphological detection and WB marker protein detection both indicate that the microvesicles obtained after ultracentrifugation of the culture supernatant conform to the characteristics of exosomes. Microscopic observation revealed the uptake of fluorescently labeled CAF-derived exosomes by bladder cancer cells. In vitro experiments using qRT-PCR, Western blot, and other assays confirmed changes in the expression of key RNAs in bladder cancer cells following exosome treatment, with corresponding changes in the expression of EMT-related proteins; results from CCK8, scratch assays, and Transwell experiments suggested that CAF-derived exosomes stimulate the proliferation and invasion capabilities of bladder cancer. In vivo experiments confirmed that exosomes can enhance the proliferative capacity of mouse bladder cancer xenografts. Overexpression of miR-130a-3p can reverse the epithelial-mesenchymal transition in bladder cancer, while supplementation with CAFs-exo can reverse this function. Dual-luciferase reporter assays validated the binding sites of lnc RNA HOTAIR with miR-130a-3p and miR-130a-3p with ZEB1, confirming that exosomal lnc RNA HOTAIR can downregulate miR-130a-3p levels through competitive action, thereby upregulating ZEB1 expression, enhancing epithelial-mesenchymal transition in bladder cancer cells and promoting their proliferation.

Tumor-derived fibroblast exosomes promote the epithelial-to-mesenchymal transition of bladder urothelial carcinoma cells and their malignant progression by interacting with the lncRNA HOTAIR and the miR-130b-3p/ZEB1 axis.