UCHL1 promotes cancer stemness in triple-negative breast cancer.

BACKGROUND: Triple-negative breast cancer (TNBC) is a special kind of breast cancer with strong ability of invasion and metastasis. UCHL1 belongs to the ubiquitin carboxy-terminal hydrolase family and is found to be increased in a variety of malignancies, but its expression in TNBC is unknown. METHODS: First, we analyzed the expression of UCHL1 in 128 TNBC specimens and paired adjacent normal tissues from 17 TNBC patients undergoing curative resection by immunohistochemistry. Then, the relationship between UCHL1 and cancer stemness was investigated by cell flow cytometry, spheroid formation assays and western blot. Moreover, cell scratch assay and Transwell assays were performed to explore whether UCHL1 promotes the migration and invasion of TNBC cells. Finally, we constructed a xenografts model of TNBC cell lines to observe the effect of UCHL1 on tumorigenesis in vivo. RESULTS: UCHL1 was overexpressed in TNBC tissues and associated with poor prognosis. UCHL1 promoted stem cancer cells properties, including the percentage of CD44+/CD24- cells, sphere-forming ability and CSCs related markers. Furthermore, Scratch assay and Transwell assay proved that UCHL1 enhanced the migration and invasion of TNBC cells. The experimental results of xenografts model in nude mice showed that UCHL1 promoted tumorigenesis of TNBC in vivo. CONCLUSION: UCHL1 may play a role in the malignant progression of TNBC by maintaining the stemness and promoting cell invasion and is expected to become a potential therapeutic target for TNBC patients.

Sorafenib inhibits ovarian cancer cell proliferation and mobility and induces radiosensitivity by targeting the tumor cell epithelial-mesenchymal transition.

Sorafenib, a pan-protein kinase inhibitor, inhibits the activity of various kinases (like vascular endothelial growth factor, platelet-derived growth factor, and rapidly accelerated fibrosarcoma) and clinically has been used to treat different human cancers. This study investigated its antitumor activity in ovarian cancer and the underlying molecular events. To achieve that, ovarian cancer SKOV-3 cells were treated with or without sorafenib (10 µM), transforming growth factor (TGF)-ß1 (10 ng/mL), sorafenib (10 µM) + TGF-ß1 (10 ng/mL), and TGF-ß1 (10 ng/mL) + Ly2157299 (5 µM), followed by 8-Gy radiation. The cells were then subjected to cell viability, wound healing, Transwell, caspase-3 activity, and western blot assays. TGF-ß1 treatment enhanced ovarian cancer cell epithelial-mesenchymal transition (EMT), whereas sorafenib and a selective TGF-ß1 inhibitor Ly2157299 reversed tumor cell EMT, invasion, and expression of EMT markers (E-cadherin and vimentin). Sorafenib and Ly2157299 treatment also significantly reduced the tumor cell viability. Furthermore, both sorafenib and Ly2157299 significantly enhanced ovarian cancer cell radiosensitivity, as assessed by a caspase-3 activity assay. In conclusion, sorafenib inhibited ovarian cancer cell proliferation and mobility and induced tumor cell radiosensitivity. Molecularly, sorafenib could inhibit the TGF-ß1-mediated EMT. Future studies will assess sorafenib anti-ovarian cancer activity plus TGF-ß1 inhibitors in ovarian cancer in vivo.