Sunitinib significantly suppresses the proliferation, migration, apoptosis resistance, tumor angiogenesis and growth of triple-negative breast cancers but increases breast cancer stem cells

Abstract

The majority of triple-negative breast cancers (TNBCs) are basal-like breast cancers. However there is no reported study on anti-tumor effects of sunitinib in xenografts of basal-like TNBC (MDA-MB-468) cells. In the present study, MDA-MB-231, MDA-MB-468, MCF-7 cells were cultured using RPMI 1640 media with 10% FBS. Vascular endothelia growth factor (VEGF) protein levels were detected using ELISA (R & D Systams). MDA-MB-468 cells were exposed to sunitinib for 18 hours for measuring proliferation (3H-thymidine incorporation), migration (BD Invasion Chamber), and apoptosis (ApopTag and ApoScreen Anuexin V Kit). The effect of sunitinib on Notch-1 expression was determined by Western blot in cultured MDA-MB-468 cells. 106 MDA-MB-468 cells were inoculated into the left fourth mammary gland fat pad in athymic nude-foxn1 mice. When the tumor volume reached 100 mm3, sunitinib was given by gavage at 80 mg/kg/2 days for 4 weeks. Tumor angiogenesis was determined by CD31 immunohistochemistry. Breast cancer stem cells (CSCs) isolated from the tumors were determined by flow cytometry analysis using CD44+/CD24- or low. ELISA indicated that VEGF was much more highly expressed in MDA-MB-468 cells than MDA-MB-231 and MCF-7 cells. Sunitinib significantly inhibited the proliferation, invasion, and apoptosis resistance in cultured basal like breast cancer cells. Sunitinib significantly increased the expression of Notch-1 protein in cultured MDA-MB-468 or MDA-MB-231 cells. The xenograft models showed that oral sunitinib significantly reduced the tumor volume of TNBCs in association with the inhibition of tumor angiogeneisis, but increased breast CSCs. These findings support the hypothesis that the possibility should be considered of sunitinib increasing breast CSCs though it inhibits TNBC tumor angiogenesis and growth/progression, and that effects of sunitinib on Notch expression and hypoxia may increase breast cancer stem cells. This work provides the groundwork for an innovative therapeutic strategy in TNBC therapy by using sunitinib plus γ-secretase inhibitor to simultaneously target angiogenesis and CSC.

Targeting MET and AXL overcomes resistance to sunitinib therapy in renal cell carcinoma

“…(Figure 2C). In contrast, sunitinib treated parental cells exhibited reduced migration (Figure 2C up-right panel), which is also observed in breast cancer cell lines (38). This could be the result of sunitinib-activated EMT signaling, which is dependent on either the activation of MET (35, 37) or AXL (21) that have been observed in other cancer cells.…”

Metabolic history impacts mammary tumor epithelial hierarchy and early drug response in mice

“…Notably, the increased resistance to tamoxifen, an anti-estrogen receptor-positive breast cancer drug, was accompanied by the selection of breast cancer cells with mammosphere-forming capacity (Raffo et al , 2013). Further, in mouse xenograft models of breast cancer, the tyrosine kinase inhibitor sunitinib was found to reduce tumor volume of triple-negative MDA-MB-468 cells but increased the frequency of breast cancer stem cells (Chinchar et al , 2014). Importantly, inhibitors of the metabolic pathway-associated mTOR were found to counteract tamoxifen-induced activation of breast cancer cells (Karthik et al , 2015), suggesting that resistance to temoxifen is associated with metabolic dysregulation.…”

Rac1 as a multifunctional therapeutic target to prevent and combat cancer metastasis

“…It was found that secretome from FaDu-IRR and SCC-IRR cells increased HMEC-1 migration by ~2.6- and ~1.4-fold compared to secretome obtained from treatment-sensitive parental FaDu and SCC25 cells, respectively (Figure 9). Administration of currently existing anti-angiogenic compounds (anti-VEGF or anti-VEGF-R antibodies or small molecules) does not markedly improve the therapeutic response of primary or metastatic lesions, because despite effective suppression of angiogenesis these compounds can increase the number of intratumoral CSCs [35]. Hence, we believe that inhibiting Rac1 signaling in HNSCC cells with CSC properties could also contribute to the decrease of neoangio- and vasculogenesis.…”