scholarly journals Loss of STAT6 leads to anchorage-independent growth and trastuzumab resistance in HER2+ breast cancer cells

PLoS ONE ◽  
2020 ◽  
Vol 15 (6) ◽  
pp. e0234146 ◽  
Author(s):  
Molly DiScala ◽  
Matthew S. Najor ◽  
Timothy Yung ◽  
Deri Morgan ◽  
Abde M. Abukhdeir ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Trastuzumab Resistance ◽  
Anchorage Independent Growth ◽  
Her2 Breast Cancer

scholarly journals Involvement of microRNA-146a in trastuzumab resistance of HER2+ breast cancer cells

2017 ◽  
Vol 28 ◽  
pp. vii25-vii26
Author(s):  
P. Cabello ◽  
J. Forés ◽  
E. Tormo ◽  
B. Pineda ◽  
A. Adam ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Trastuzumab Resistance ◽  
Her2 Breast Cancer

Abstract 349: Autophagy, cancer stem cells, and trastuzumab resistance in three dimensional cultures of HER2+ breast cancer cells

2015 ◽  
Author(s):  
Cristina E. Rodríguez ◽  
Sara Reidel ◽  
Maria Adela Jasnis ◽  
Elisa Bal de Kier joffe ◽  
Gabriel L. Fiszman
Keyword(s):  
Breast Cancer ◽  
Stem Cells ◽  
Cancer Stem Cells ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Three Dimensional ◽  
Trastuzumab Resistance ◽  
Her2 Breast Cancer

Effect of cyclin E overexpression on resistance to trastuzumab and phosphorylation of SMAD3 in HER2+ breast cancer.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e12006-e12006
Author(s):  
Pridvi Kandagatla ◽  
Joseph Decker ◽  
Lei Wan ◽  
Regan Bernstein ◽  
Lonnie Shea ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Cyclin E ◽  
In Vivo Studies ◽  
Parental Line ◽  
Trastuzumab Resistance ◽  
Linker Region ◽  
Her2 Breast Cancer

e12006 Background: Trastuzumab, an effective treatment for HER2+ breast cancer, can be limited by development of resistance. Cyclin E (CCNE) overexpression was implicated in trastuzumab resistance, though the association is not well understood. We sought to explore a potential mechanism focusing on altered phosphorylation of the TGFβ signaling protein, SMAD3, in CCNE overexpressing HER2+ breast cancer cells, leading to trastuzumab resistance. Methods: A transcriptional activity cell array (TRACER) was used to examine the relationship between specific transcription factors and trastuzumab resistance in BT474 HER2+ human breast cancer cells. Immunoblotting examined phosphorylation patterns of SMAD3 in trastuzumab sensitive and resistant conditions. Effects of blocking CCNE overexpression with a CDK2 inhibitor were measured. To test the relative influence of SMAD3 and SMAD3 linker region phosphorylation on cell proliferation, BT474R2 cell lines were created overexpressing SMAD3 (BT474R2-SMAD3), a mutant construct blocking CCNE-mediated SMAD3 linker region phosphorylation (BT474R2-5M), and a control (BT474R2-Blank). In vitro and in vivo studies measured response to trastuzumab. Results: Resistance to trastuzumab was confirmed for BT474R2 cells, showing a markedly increased resistance to treatment when compared to the parental line. Network analysis of TRACER data identified decreased SMAD3 activity was central to resistance. Immunoblotting showed SMAD3 expression was significantly downregulated in BT474R2 cells (p < 0.01). Noncanonical phosphorylation of SMAD3 was increased in CCNE-overexpressing cells. Blocking CCNE mediated noncanonical phosphorylation of SMAD3 with CDK2 inhibition resulted in decreased proliferation of BT474R2 cells. In vitro studies examining response to trastuzumab showed an increased sensitivity for BT474R2-5M cells. Findings were validated in NSG mice inoculated with BT474R2-5M cells that developed significantly lower tumor volumes (p < 0.001) when treated with trastuzumab. Conclusions: These results identified a mechanism of CCNE-mediated trastuzumab resistance, regulated through noncanonical SMAD3 phosphorylation, which may be effectively treated with CDK2 inhibition to help enhance the efficacy of trastuzumab for patients with 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.

scholarly journals Overcoming Trastuzumab Resistance in HER2-Overexpressing Breast Cancer Cells by Using a Novel Celecoxib-Derived Phosphoinositide-Dependent Kinase-1 Inhibitor

2006 ◽  
Vol 70 (5) ◽  
pp. 1534-1541 ◽  
Author(s):  
Ping-Hui Tseng ◽  
Yu-Chieh Wang ◽  
Shu-Chuan Weng ◽  
Jing-Ru Weng ◽  
Chang-Shi Chen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Trastuzumab Resistance ◽  
Phosphoinositide Dependent Kinase

PCSK9 inhibitor evolocumab to increase anticancer activities and reduce cardiotoxicity during doxorubicin and trastuzumab, as sequential treatment, through MyD88/NF-kB/mTORC1 pathways.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e15039-e15039
Author(s):  
Vincenzo Quagliariello ◽  
Simona Buccolo ◽  
Martina Iovine ◽  
Andrea Paccone ◽  
Annamaria Bonelli ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cardiovascular Diseases ◽  
Cell Viability ◽  
Statin Therapy ◽  
Cancer Cells ◽  
Cardiovascular Events ◽  
Breast Cancer Cells ◽  
Sequential Treatment ◽  
Pcsk9 Inhibitor ◽  
Her2 Breast Cancer

e15039 Background: Inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9) has emerged as a novel therapy to treat hypercholesterolaemia and related cardiovascular diseases. Evolocumab, a PCSK9 inhibitor, reduced the risk of cardiovascular events in patients with atherosclerotic cardiovascular diseases when added to maximally tolerated statin therapy (± ezetimibe), and recent data from the ODYSSEY OUTCOMES trial indicate that alirocumab added to maximally tolerated statin therapy (± other lipid-lowering drugs) reduces the risk of cardiovascular events in patients with a recent acute coronary syndrome. Methods: Human fetal cardiomyocytes (HFC cell line), human HER2+ breast cancer cells were exposed to subclinical concentration of doxorubicin, trastuzumab, sequential treatment of both (all 100 nM), alone or in combination with evolocumab (50 nM) for 24 and 48h. After the incubation period, we performed the following tests: determination of cell viability, through analysis of mitochondrial dehydrogenase activity, study of lipid peroxidation (quantifying cellular Malondialdehyde and 4-hydroxynonenal), intracellular Ca2+ homeostasis. Moreover, pro-inflammatory studied were also performed (activation of NLRP3 inflammasome; expression of TLR4/MyD88; mTORC1 Fox01/3a; transcriptional activation of p65/NF-κB and secretion of cytokines involved in cardiotoxicity (Interleukins 1β, 8, 6). Results: Evolocumab co-incubated with doxorubicin alone or in sequence with trastuzumab exerts cardioprotective effects, enhancing cell viability of 35-43% compared to untreated cells (p < 0,05 for all); in cardiomyocytes Evolocumab reduced significantly the cardiotoxicity through MyD88/NF-KB/cytokines axis and mTORC1 Fox01/3α mediated mechanisms. In human HER2+ breast cancer cells, co-exposure of Evolocumab with doxorubicin and trastuzumab increased significantly cell apoptosis and necrosis through the involvement of key cytokines involved in chemoresistence. Conclusions: We demonstrated, for the first time, that the PCSK9 inhibitor evolocumab exerts direct effects in cardiomyocytes and human HER2+ breast cancer cells during doxorubicin and trastuzumab exposure turning on a new light on its possible use in the management of breast cancer therapies.

Pyrotinib sensitizes 5‑fluorouracil‑resistant HER2-positive breast cancer cells to 5‑fluorouracil

2020 ◽  
Author(s):  
Jianing Yi ◽  
Pingyong Yi ◽  
Shuai Chen ◽  
Qian Li ◽  
Runzhang Wu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cell Lines ◽  
Combination Treatment ◽  
Breast Cancer Cells ◽  
Continuous Exposure ◽  
Her2 Positive ◽  
Her2 Positive Breast Cancer ◽  
Her2 Breast Cancer ◽  
Positive Breast Cancer

Abstract BACKGROUND: Clinical trials have shown that pyrotinib+ capecitabine significantly improved efficacy of patients with human epidermal growth factor receptor 2(HER2) +breast cancer. However, whether pyrotinib sensitizes 5‑Fluorouracil(5‑FU)‑resistant breast cancer cells to 5‑FU is unknown. This study aimed to investigate the effects of pyrotinib on HER2+breast cancer cells with resistance to 5‑FU and provide new clues for the pyrotinib treatment in 5-FU-resistant breast cancer.METHODS: the 5‑FU‑resistant breast cancer cell lines SK-BR-3/FU and MAD-MB-453/FU were established by continuous exposure of the parental cells to 5‑FU.The effects of pyrotinib on these cell lines were examined by growth inhibitory activity assay, reverse transcription‑quantitative polymerase chain reaction, Western blot analysis, high-performance liquid chromatography and animal experiments.RESULTS: Pyrotinib inhibited the proliferation of 5-FU-resistant and parental HER2-positive breast cancer cells and re-sensitized resistant cells to 5-FU by decreasing the expression of thymidylate synthase(TS) and ABC transporter subfamily G member 2(ABCG2). In a xenograft model, combination treatment with 5-FU and pyrotinib showed greater antitumor activity than either agent alone. CONCLUSIONS: Our results offer a preclinical rationale for clinical investigations of combination treatment with pyrotinib and 5-FU for 5-FU-resistant HER2-positive breast cancer.

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