Estrogen and the selective estrogen receptor modulator (SERM) protection against cell death in estrogen receptor alpha and beta expressing U2OS cells

AbstractMost women diagnosed with breast cancer (BC) have estrogen receptor alpha positive (ER+) disease. ER+ BC preferentially metastasizes to bone; at which time it is considered incurable. Treatments for bone metastasis have not advanced in decades, in part due to a lack of appropriate ER+ BC bone metastasis models. We developed an immunocompetent ER+ BC murine model with spontaneous bone metastasis and antiestrogen responsiveness. To do this, we transduced triple-negative (TN) bone-tropic murine BC cell lines 4T1.2 and E0771/Bone to express ERα. These cells were then injected into the mammary fat pads of Balb/c (n=21) or C57Bl/6 (n=27), respectively. Once tumors established, mice were treated with either the selective estrogen receptor modulator (SERM) tamoxifen (TAM), the selective estrogen receptor degrader (SERD) ICI 182,780 (ICI, Faslodex, fulvestrant), or vehicle control for 21 days. Tumor volumes and weights significantly decreased in the ER+ groups treated with TAM and ICI compared with ER+ vehicle-treated groups. Staining for immune profiles and total RNA sequencing demonstrated modified immune cell infiltration between TN and ER-derived tumors. Approximately 25% of the mice with ER+ 4T1.2 tumors developed metastases to long bones while none of the mice with TN tumors developed metastases. This immunocompetent ER+ 4T1.2 BC model may allow for further exploration of ER+ BC bone metastasis mechanisms and for the development of new therapeutics for women diagnosed with bone metastasis from ER+ BC.Simple SummaryEstrogen receptor alpha positive (ER+) breast cancer is the most common subtype of breast cancer. When it metastasizes to bone, it becomes incurable. Little advancement has occurred in the treatment of bone metastasis from ER+ breast cancer, partly due to the lack of animal models. To establish an animal model of ER+ BC, we genetically modified two triple-negative breast cancer cell lines to express ERα and injected the cell lines into murine mammary glands. Mice were treated with standard antiestrogen therapies, the selective estrogen receptor modulator tamoxifen or the selective estrogen receptor degrader ICI 182,780. We found that compared to mice with triple-negative breast cancer, mice with ER+ breast cancer developed bone metastases and were responsive to antiestrogen therapy. This model allows for further exploration of bone metastasis mechanisms and for the development of new therapeutics, translating into improved clinical outcomes for women with bone metastasis from ER+ breast cancer.

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Abstract B255: Development of hybrid small molecules that induce degradation of estrogen receptor-alpha and necrotic cell death in breast cancer cells.

10.1158/1535-7163.targ-13-b255 ◽

2013 ◽

Author(s):

Keiichiro Okuhira ◽

Yosuke Demizu ◽

Takayuki Hattori ◽

Nobumichi Ohoka ◽

Norihito Shibata ◽

...

Keyword(s):

Breast Cancer ◽

Cell Death ◽

Estrogen Receptor ◽

Small Molecules ◽

Cancer Cells ◽

Breast Cancer Cells ◽

Estrogen Receptor Alpha ◽

Necrotic Cell Death ◽

Necrotic Cell ◽

Receptor Alpha

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17-beta estradiol inhibits oxidative stress-induced accumulation of AIF into nucleolus and PARP1-dependent cell death via estrogen receptor alpha

Toxicology Letters ◽

10.1016/j.toxlet.2014.09.024 ◽

2015 ◽

Vol 232 (1) ◽

pp. 1-9 ◽

Cited By ~ 14

Author(s):

Enkhzaya Batnasan ◽

Ruoxi Wang ◽

Jitao Wen ◽

Yueshuang Ke ◽

Xiaoxue Li ◽

...

Keyword(s):

Oxidative Stress ◽

Cell Death ◽

Estrogen Receptor ◽

Estrogen Receptor Alpha ◽

Receptor Alpha ◽

Dependent Cell

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Development of hybrid small molecules that induce degradation of estrogen receptor-alpha and necrotic cell death in breast cancer cells

Cancer Science ◽

10.1111/cas.12272 ◽

2013 ◽

Vol 104 (11) ◽

pp. 1492-1498 ◽

Cited By ~ 63

Author(s):

Keiichiro Okuhira ◽

Yosuke Demizu ◽

Takayuki Hattori ◽

Nobumichi Ohoka ◽

Norihito Shibata ◽

...

Keyword(s):

Breast Cancer ◽

Cell Death ◽

Estrogen Receptor ◽

Small Molecules ◽

Cancer Cells ◽

Breast Cancer Cells ◽

Estrogen Receptor Alpha ◽

Necrotic Cell Death ◽

Necrotic Cell ◽

Receptor Alpha

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Transcriptional activities of estrogen receptor alpha and beta in yeast properties of raloxifene 1 1Abbreviations: ERE, estrogen response element; E2, 17β-estradiol; RAL, raloxifene; ERα, estrogen receptor α; ERβ, estrogen receptor β; and SERM, selective estrogen receptor modulator.

Biochemical Pharmacology ◽

10.1016/s0006-2952(01)00731-6 ◽

2001 ◽

Vol 62 (7) ◽

pp. 953-961 ◽

Cited By ~ 30

Author(s):

Elisabeth Jisa ◽

Eva Dornstauder ◽

Sumito Ogawa ◽

Sathoshi Inoue ◽

Masami Muramatsu ◽

...

Keyword(s):

Estrogen Receptor ◽

Estrogen Receptor Alpha ◽

Estrogen Receptor Α ◽

Estrogen Receptor Β ◽

Estrogen Response Element ◽

Response Element ◽

Receptor Alpha ◽

Receptor Modulator ◽

Estrogen Response ◽

17Β Estradiol

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Suppression of Estrogen Receptor Alpha Inhibits Cell Proliferation, Differentiation and Enhances the Chemosensitivity of P53-Positive U2OS Osteosarcoma Cell

International Journal of Molecular Sciences ◽

10.3390/ijms222011238 ◽

2021 ◽

Vol 22 (20) ◽

pp. 11238

Author(s):

Jir-You Wang ◽

Chao-Ming Chen ◽

Cheng-Fong Chen ◽

Po-Kuei Wu ◽

Wei-Ming Chen

Keyword(s):

Cell Cycle ◽

Growth Rate ◽

Estrogen Receptor ◽

Cell Line ◽

Colony Formation ◽

Estrogen Receptor Alpha ◽

Receptor Alpha ◽

Chemical Treatments ◽

U2os Cells

Osteosarcoma is a highly malignant musculoskeletal tumor that is commonly noticed in adolescent children, young children, and elderly adults. Due to advances in surgery, chemotherapy and imaging technology, survival rates have improved to 70–80%, but chemical treatments do not enhance patient survival; in addition, the survival rate after chemical treatments is still low. The most obvious clinical feature of osteosarcoma is new bone formation, which is called “sun burst”. Estrogen receptor alpha (ERα) is an essential feature of osteogenesis and regulates cell growth in various tumors, including osteosarcoma. In this study, we sought to investigate the role of ERα in osteosarcoma and to determine if ERα can be used as a target to facilitate the chemosensitivity of osteosarcoma to current treatments. The growth rate of each cell clone was assayed by MTT and trypan blue cell counting, and cell cycle analysis was conducted by flow cytometry. Osteogenic differentiation was induced by osteogenic induction medium and quantified by ARS staining. The effects of ERα on the chemoresponse of OS cells treated with doxorubicin were evaluated by colony formation assay. Mechanistic studies were conducted by examining the levels of proteins by Western blot. The role of ERα on OS prognosis was investigated by an immunohistochemical analysis of OS tissue array. The results showed an impaired growth rate and a decreased osteogenesis ability in the ERα-silenced P53(+) OS cell line U2OS, but not in P53(−) SAOS2 cells, compared with the parental cell line. Cotreatment with tamoxifen, an estrogen receptor inhibitor, increased the sensitivity to doxorubicin, which decreased the colony formation of P53(+) U2OS cells. Cell cycle arrest in the S phase was observed in P53(+) U2OS cells cotreated with low doses of doxorubicin and tamoxifen, while increased levels of apoptosis factors indicated cell death. Moreover, patients with ER−/P53(+) U2OS showed better chemoresponse rates (necrosis rate > 90%) and impaired tumor sizes, which were compatible with the findings of basic research. Taken together, ERα may be a potential target of the current treatments for osteosarcoma that can control tumor growth and improve chemosensitivity. In addition, the expression of ERα in osteosarcoma can be a prognostic factor to predict the response to chemotherapy.

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