Pyrotinib is effective in both trastuzumab-sensitive and primary resistant HER2-positive breast tumors

Objective: Primary resistance to trastuzumab frequently occurs in human epidermal growth factor receptor 2(HER2)-positive(+) breast cancer patients and remains a clinical challenge. Pyrotinib is a novel tyrosine kinase inhibitor that has shown efficacy in the treatment of HER2+ breast cancer. However, the efficacy of pyrotinib in HER2+ breast cancer with primary trastuzumab resistance is unknown.Methods: HER2+ breast cancer cells sensitive or primarily resistant to trastuzumab were treated with trastuzumab, pyrotinib, or the combination. Cell proliferation, migration, invasion, and HER2 downstream signal pathways were analyzed. The effects of pyrotinib plus trastuzumab and pertuzumab plus trastuzumab were compared in breast cancer cells in vitro and a xenograft mouse model with primary resistance to trastuzumab.Results: Pyrotinib had a therapeutic effect on trastuzumab-sensitive HER2+ breast cancer cells by inhibiting phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT) and rat sarcoma virus(RAS)/rapidly accelerated fibrosarcoma(RAF)/mitogen-activated protein kinase(MAPK)/extracellular-signal regulated kinase(ERK)pathways. In primary trastuzumab-resistant cells, pyrotinib inhibited cell growth, migration, invasion, and HER2 downstream pathways, whereas trastuzumab had no effects. The combination with trastuzumab did not show increased effects compared with pyrotinib alone. Compared with pertuzumab plus trastuzumab, pyrotinib plus trastuzumab was more effective in inhibiting cell proliferation and HER2 downstream pathways in breast cancer cells and tumor growth in a trastuzumab-resistant HER2+ breast cancer xenograft model.Conclusions: Pyrotinib-containing treatments exhibited anti-cancer effects in HER2+ breast cancer cells sensitive and with primary resistance to trastuzumab. Notably, pyrotinib plus trastuzumab was more effective than trastuzumab plus pertuzumab in inhibiting tumor growth and HER2 downstream pathways in HER2+ breast cancer with primary resistance to trastuzumab. These findings support clinical testing of the therapeutic efficacy of dual anti-HER2 treatment combining an intracellular small molecule with an extracellular antibody.

Adipocyte-derived SFRP5 inhibits breast cancer cells migration and invasion through Wnt and epithelial-mesenchymal transition signaling pathways

Objective:Obesity is closely associated with metastasis in breast cancer patients.Secreted frizzled-related protein 5(SFRP5),one of the novel adipokines with anti-inflammatory properties,is associated with obesity.This study aims to study the role of SFRP5 in the crosstalk between obesity and breast cancer metastasis and identify the underlying mechanism.Methods:3T3-L1 pre-adipocytes were differentiated to mature adipocytes and a hypertrophic adipocyte model was induced with palmitic acid(PA).Cell motility was measured in MDA-MB-231 and MCF-7 breast cancer cells co-cultured with adipocytes conditioned medium(CM)with or without SFRP5 protein.Wnt and epithelialmesenchymal transition(EMT)signal pathways were investigated by western blot.Circulating SFRP5 level in 218 breast cancer patients and the association with clinicopathologic characteristics of breast cancer were further determined.Online databases ENCORI and PREDICT Plus were used to exam the link between SFRP5 and prognosis.Results:Reduced SFRP5 level was detected in the hypertrophic adipocyte model.Recombinant SFRP5 protein inhibited MDA-MB-231 and MCF-7 cells invasion and migration induced by PA-treated adipocyte CM,and SFRP5 inhibition by specific antibody reversed the effect of SFRP5.Furthermore,SFRP5 significantly inhibited Wnt and downstream EMT in breast cancer cells.Low circulating SFRP5 level correlated with body mass index(BMI),lymph node(LN)metastasis,TNM stage and high Ki67 expression in breast cancer patients.Increased SFRP5 level was associated with favorable predicted survival.Kaplan-Meier curves showed high SFRP5 level in tumor tissue was associated with better outcome of breast cancer patients.Conclusions:Our findings demonstrated SFRP5 is a vital adipokine that mediates the crosslink between obesity and the metastatic potential of breast cancer.Promotion of SFRP5 expression in the adipose microenvironment may represent a novel approach for preventing breast cancer metastasis.

Depressive Symptoms and Sleep Duration as Risk Factors for Breast Cancer—China,2020

Summary What is already known about this topic?Psychological and lifestyle factors are known to potentially play a significant role in the development of breast cancer.However,current evidence-based studies present controversial findings on the associations between depression,sleep duration,and breast cancer risk.