scholarly journals Direct Inhibition of PI3K in Combination with Dual HER2 Inhibitors is Required for Optimal Antitumor Activity in HER2+ Breast Cancer Cells

2014 ◽  
pp. 55-80
Author(s):  
Brent Rexer ◽  
Siprachanh Chanthaphaychith ◽  
Kimberly Dahlman ◽  
Carlos Arteaga
Keyword(s):  
Breast Cancer ◽  
Antitumor Activity ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Direct Inhibition ◽  
Her2 Breast Cancer

scholarly journals Metformin partially reverses the inhibitory effect of co-culture with ER-/PR-/HER2+ breast cancer cells on biomarkers of monocyte antitumor activity

PLoS ONE ◽  
2020 ◽  
Vol 15 (10) ◽  
pp. e0240982
Author(s):  
Zoheir Dahmani ◽  
Lynda Addou-Klouche ◽  
Florence Gizard ◽  
Sara Dahou ◽  
Aida Messaoud ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Antitumor Activity ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Inhibitory Effect ◽  
Her2 Breast Cancer

scholarly journals Fatty Acid Synthase Confers Tamoxifen Resistance to ER+/HER2+ Breast Cancer

Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1132
Author(s):  
Javier A. Menendez ◽  
Adriana Papadimitropoulou ◽  
Travis Vander Steen ◽  
Elisabet Cuyàs ◽  
Bharvi P. Oza-Gajera ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Fatty Acid ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Promoter Activity ◽  
Fatty Acid Synthase ◽  
Endocrine Resistance ◽  
Gene Promoter ◽  
Her2 Positive ◽  
Her2 Breast Cancer

The identification of clinically important molecular mechanisms driving endocrine resistance is a priority in estrogen receptor-positive (ER+) breast cancer. Although both genomic and non-genomic cross-talk between the ER and growth factor receptors such as human epidermal growth factor receptor 2 (HER2) has frequently been associated with both experimental and clinical endocrine therapy resistance, combined targeting of ER and HER2 has failed to improve overall survival in endocrine non-responsive disease. Herein, we questioned the role of fatty acid synthase (FASN), a lipogenic enzyme linked to HER2-driven breast cancer aggressiveness, in the development and maintenance of hormone-independent growth and resistance to anti-estrogens in ER/HER2-positive (ER+/HER2+) breast cancer. The stimulatory effects of estradiol on FASN gene promoter activity and protein expression were blunted by anti-estrogens in endocrine-responsive breast cancer cells. Conversely, an AKT/MAPK-related constitutive hyperactivation of FASN gene promoter activity was unaltered in response to estradiol in non-endocrine responsive ER+/HER2+ breast cancer cells, and could be further enhanced by tamoxifen. Pharmacological blockade with structurally and mechanistically unrelated FASN inhibitors fully impeded the strong stimulatory activity of tamoxifen on the soft-agar colony forming capacity—an in vitro metric of tumorigenicity—of ER+/HER2+ breast cancer cells. In vivo treatment with a FASN inhibitor completely prevented the agonistic tumor-promoting activity of tamoxifen and fully restored its estrogen antagonist properties against ER/HER2-positive xenograft tumors in mice. Functional cancer proteomic data from The Cancer Proteome Atlas (TCPA) revealed that the ER+/HER2+ subtype was the highest FASN protein expressor compared to basal-like, HER2-enriched, and ER+/HER2-negative breast cancer groups. FASN is a biological determinant of HER2-driven endocrine resistance in ER+ breast cancer. Next-generation, clinical-grade FASN inhibitors may be therapeutically relevant to countering resistance to tamoxifen in FASN-overexpressing ER+/HER2+ breast carcinomas.

scholarly journals MicroRNA in combination with HER2-targeting drugs reduces breast cancer cell viability in vitro

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lisa Svartdal Normann ◽  
Miriam Ragle Aure ◽  
Suvi-Katri Leivonen ◽  
Mads Haugland Haugen ◽  
Vesa Hongisto ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cell Lines ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Breast Cancer Cells ◽  
Targeted Treatment ◽  
Breast Cancer Cell Lines ◽  
Altered Expression ◽  
Her2 Breast Cancer

AbstractHER2-positive (HER2 +) breast cancer patients that do not respond to targeted treatment have a poor prognosis. The effects of targeted treatment on endogenous microRNA (miRNA) expression levels are unclear. We report that responsive HER2 + breast cancer cell lines had a higher number of miRNAs with altered expression after treatment with trastuzumab and lapatinib compared to poorly responsive cell lines. To evaluate whether miRNAs can sensitize HER2 + cells to treatment, we performed a high-throughput screen of 1626 miRNA mimics and inhibitors in combination with trastuzumab and lapatinib in HER2 + breast cancer cells. We identified eight miRNA mimics sensitizing cells to targeted treatment, miR-101-5p, mir-518a-5p, miR-19b-2-5p, miR-1237-3p, miR-29a-3p, miR-29c-3p, miR-106a-5p, and miR-744-3p. A higher expression of miR-101-5p predicted better prognosis in patients with HER2 + breast cancer (OS: p = 0.039; BCSS: p = 0.012), supporting the tumor-suppressing role of this miRNA. In conclusion, we have identified miRNAs that sensitize HER2 + breast cancer cells to targeted therapy. This indicates the potential of combining targeted drugs with miRNAs to improve current treatments for HER2 + breast cancers.

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