Abstract P4-03-12: Effects of PI3K inhibitors on endocrine-resistant cell lines and differences in the characteristics of ER positive breast cancer cells after acquired resistance to the inhibitors

2018 ◽  
Author(s):  
E Tokuda ◽  
T Komatsu ◽  
S Sasaki ◽  
K Tsuboi ◽  
M Nakamura ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cell Lines ◽  
Breast Cancer Cells ◽  
Acquired Resistance ◽  
Resistant Cell ◽  
Pi3k Inhibitors ◽  
Er Positive ◽  
Positive Breast Cancer

scholarly journals Paeoniflorin Enhances the Sensitivity of ER-Positive Breast Cancer Cells to Tamoxifen through Promoting Sirtuin 4

2022 ◽  
Vol 2022 ◽  
pp. 1-11
Author(s):  
Pei Zhang ◽  
Nan Wu ◽  
Zhi-Jun Song ◽  
Zheng-Fu Tai
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Protein Expression ◽  
Cancer Cells ◽  
Cell Lines ◽  
Breast Cancer Cells ◽  
Expression Ratio ◽  
Er Positive ◽  
Mcf 7 ◽  
Positive Breast Cancer

Tamoxifen is an effective drug for treating patients with advanced estrogen receptor-positive (ER+) breast cancer (BC), but not for all ER + BC patients. Drug tolerance is the biggest obstacle. In this study, we designed an experiment to investigate whether paeoniflorin affects the ER + BC cell’s sensitivity to tamoxifen in the T47D and MCF-7 cell lines. Herein, we found that paeoniflorin inhibited cell proliferation without inducing apoptosis. However, it enhanced tamoxifen-induced apoptosis in both cell lines. Immunoblotting revealed that paeoniflorin significantly increased the already elevated Bax/Bcl2 protein expression ratio and the caspase 3 activity levels, both induced by tamoxifen. Paeoniflorin was also found to increase SIRT4 expression, and deletion of SIRT4 could significantly reverse the inhibition of cell proliferation induced by paeoniflorin and significantly decrease paeoniflorin-enhanced apoptosis induced by tamoxifen. Moreover, protein expression detection revealed that paeoniflorin enhanced the tamoxifen-induced inhibition of STAT3 activation. Besides, the deletion of SIRT4 could significantly increase STAT3 activation in the T47D and MCF-7 cells. In conclusion, paeoniflorin suppressed STAT3 activation to enhance the sensitivity of ER-positive breast cancer cells to tamoxifen through promoting SIRT4 expression.

Molecular identification of ER?-positive breast cancer cells by the expression profile of an intrinsic set of estrogen regulated genes

2004 ◽  
Vol 200 (3) ◽  
pp. 440-450 ◽  
Author(s):  
Alessandro Weisz ◽  
Walter Basile ◽  
Claudio Scafoglio ◽  
Lucia Altucci ◽  
Francesco Bresciani ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Expression Profile ◽  
Molecular Identification ◽  
Breast Cancer Cells ◽  
Er Positive ◽  
Positive Breast Cancer

scholarly journals Selenium inhibits growth of trastuzumab-resistant human breast cancer cells via downregulation of Akt and beclin-1

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257298
Author(s):  
Joohyun Woo ◽  
Jong Bin Kim ◽  
Taeeun Cho ◽  
Eun Hye Yoo ◽  
Byung-In Moon ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cell Lines ◽  
Combination Treatment ◽  
Breast Cancer Cells ◽  
Antitumor Effect ◽  
Beclin 1 ◽  
Her2 Positive ◽  
Phosphorylated Akt ◽  
Positive Breast Cancer

The response rate to treatment with trastuzumab (Tz), a recombinant humanized anti-HER2 monoclonal antibody, is only 12–34% despite demonstrated effectiveness on improving the survival of patients with HER2-positive breast cancers. Selenium has an antitumor effect against cancer cells and can play a cytoprotective role on normal cells. This study investigated the effect of selenium on HER2-positive breast cancer cells and the mechanism in relation to the response of the cells to Tz. HER2-positive breast cancer cell lines, SK-BR-3 as trastuzumab-sensitive cells, and JIMT-1 as Tz-resistant cells were treated with Tz and sodium selenite (selenite). Cell survival rates and expression of Her2, Akt, and autophagy-related proteins, including LC3B and beclin 1, in both cell lines 72 h after treatment were evaluated. Significant cell death was induced at different concentrations of selenite in both cell lines. A combined effect of selenite and Tz at 72 h was similar to or significantly greater than each drug alone. The expression of phosphorylated Akt (p-Akt) was decreased in JIMT-1 after combination treatment compared to that after only Tz treatment, while p-Akt expression was increased in SK-BR-3. The expression of beclin1 increased particularly in JIMT-1 after only Tz treatment and was downregulated by combination treatment. These results showed that combination of Tz and selenite had an antitumor effect in Tz-resistant breast cancer cells through downregulation of phosphorylated Akt and beclin1-related autophagy. Selenite might be a potent drug to treat Tz-resistant breast cancer by several mechanisms.

scholarly journals HOXA5 Expression Is Elevated in Breast Cancer and Is Transcriptionally Regulated by Estradiol

2020 ◽  
Vol 11 ◽  
Author(s):  
Imran Hussain ◽  
Paromita Deb ◽  
Avisankar Chini ◽  
Monira Obaid ◽  
Arunoday Bhan ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Female Rats ◽  
Er Positive ◽  
Gene Regulatory ◽  
Cancer Tissues ◽  
Positive Breast Cancer

HOXA5 is a homeobox-containing gene associated with the development of the lung, gastrointestinal tract, and vertebrae. Here, we investigate potential roles and the gene regulatory mechanism in HOXA5 in breast cancer cells. Our studies demonstrate that HOXA5 expression is elevated in breast cancer tissues and in estrogen receptor (ER)-positive breast cancer cells. HOXA5 expression is critical for breast cancer cell viability. Biochemical studies show that estradiol (E2) regulates HOXA5 gene expression in cultured breast cancer cells in vitro. HOXA5 expression is also upregulated in vivo in the mammary tissues of ovariectomized female rats. E2-induced HOXA5 expression is coordinated by ERs. Knockdown of either ERα or ERβ downregulated E2-induced HOXA5 expression. Additionally, ER co-regulators, including CBP/p300 (histone acetylases) and MLL-histone methylases (MLL2, MLL3), histone acetylation-, and H3K4 trimethylation levels are enriched at the HOXA5 promoter in present E2. In summary, our studies demonstrate that HOXA5 is overexpressed in breast cancer and is transcriptionally regulated via estradiol in breast cancer cells.

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.

scholarly journals SGK3 Is an Estrogen-Inducible Kinase Promoting Estrogen-Mediated Survival of Breast Cancer Cells

2011 ◽  
Vol 25 (1) ◽  
pp. 72-82 ◽  
Author(s):  
Yuanzhong Wang ◽  
Dujin Zhou ◽  
Sheryl Phung ◽  
Selma Masri ◽  
David Smith ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Protein Kinase ◽  
Cell Survival ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Dependent Manner ◽  
Binding Regions ◽  
Er Positive ◽  
Mcf 7 ◽  
Positive Breast Cancer

Serum- and glucocorticoid-inducible kinase 3 (SGK3) is a protein kinase of the AGC family of protein kinase A, protein kinase G, and protein kinase C and functions downstream of phosphatidylinositol 3-kinase (PI3K). Recent study revealed that SGK3 plays a pivotal role in Akt/protein kinase B independent signaling downstream of oncogenic PI3KCA mutations in breast cancer. Here we report that SGK3 is an estrogen receptor (ER) transcriptional target and promotes estrogen-mediated cell survival of ER-positive breast cancer cells. Through a meta-analysis on 22 microarray studies of breast cancer in the Oncomine database, we found that the expression of SGK3 is significantly higher (5.7-fold, P < 0.001) in ER-positive tumors than in ER-negative tumors. In ER-positive breast cancer cells, SGK3 expression was found to be induced by 17β-estradiol (E2) in a dose- and time-dependent manner, and the induction of SGK3 mRNA by E2 is independent of newly synthesized proteins. We identified two ERα-binding regions at the sgk3 locus through chromatin immunoprecipitation with massively parallel DNA sequencing. Promoter analysis revealed that ERα stimulates the activity of sgk3 promoters by interaction with these two ERα-binding regions on E2 treatment. Loss-of-function analysis indicated that SGK3 is required for E2-mediated cell survival of MCF-7 breast carcinoma cells. Moreover, overexpression of SGK3 could partially protect MCF-7 cells against apoptosis caused by antiestrogen ICI 182,780. Together, our study defines the molecular mechanism of regulation of SGK3 by estrogen/ER and provides a new link between the PI3K pathway and ER signaling as well as a new estrogen-mediated cell survival mechanism mediated by SGK3 in breast cancer cells.

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