scholarly journals Upregulation of miR-206 is a potential diagnostic biomarker in breast cancer

Bionatura ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 1757-1762
Author(s):  
Faezeh Karami ◽  
Narges Maleki ◽  
Arefeh Khazraei Monfared ◽  
Sayeh Jafari Marandi
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Cancer Cells ◽  
Tumor Cells ◽  
Breast Cancer Cells ◽  
Culture Medium ◽  
Expression Level ◽  
Tamoxifen Treatment ◽  
Fibroblast Cells ◽  
Twist 1

Breast cancer is one of the most common malignancies, and like most cancers, most cases are caused by somatic mutations. Due to estrogen's role in the growth, differentiation, and division of breast and endometrial cancer cells, tamoxifen is used as an estrogen receptor antagonist in breast cancer cells with estrogen receptor (ER +) has a special place, which unfortunately in one-third of the Cases are resisted. This study aimed to investigate the effect of tamoxifen-treated tumor-derived exosomes on the expression pattern of Twist and Bcl-2 oncogenic genes in fibroblast cells. MCF-7 breast cancer cell line and fibroblast cells were purchased and cultured in a complete culture medium. After the appropriate number of cells was reached, they were treated with the appropriate concentration of tamoxifen. Cellular supernatant was then gathered in flasks, and exosomes were extracted from them. After extracting RNA from exosomes and cDNA synthesis, the expression level of miR-206, Twist-1, and Bcl-2 genes were evaluated using the Real-Time PCR method. The electronic microscope results confirmed the correctness of the exosomes isolated from the tumor cell culture medium. It has also been shown that tamoxifen treatment increases the expression of miR-206 in exosomes derived from breast tumor cells. The control group which has been kept untreated induced the expression level of Twist-1 and Bcl-2 genes time-dependently. However, when tamoxifen-treated tumor-derived exosomes treated the target cells, the expression level of oncogenic miRs Twist-1 and Bcl-2 were declined over time. Overall, this study showed that tamoxifen treatment on breast cancer cells could apply its antioncogenic effects on tumor stromal cells, such as fibroblasts, by altering the expression levels of exosomal microRNAs in tumor cells.

scholarly journals Poly-ADP-Ribosylation of Estrogen Receptor-Alpha by PARP1 Mediates Antiestrogen Resistance in Human Breast Cancer Cells

Cancers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 43 ◽  
Author(s):  
Nicholas Pulliam ◽  
Jessica Tang ◽  
Weini Wang ◽  
Fang Fang ◽  
Riddhi Sood ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Oxidative Stress ◽  
Estrogen Receptor ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Target Genes ◽  
Tamoxifen Resistance ◽  
Tamoxifen Treatment ◽  
Dependent Manner ◽  
Tamoxifen Resistant

Therapeutic targeting of estrogen receptor-α (ERα) by the anti-estrogen tamoxifen is standard of care for premenopausal breast cancer patients and remains a key component of treatment strategies for postmenopausal patients. While tamoxifen significantly increases overall survival, tamoxifen resistance remains a major limitation despite continued expression of ERα in resistant tumors. Previous reports have described increased oxidative stress in tamoxifen resistant versus sensitive breast cancer and a role for PARP1 in mediating oxidative damage repair. We hypothesized that PARP1 activity mediated tamoxifen resistance in ERα-positive breast cancer and that combining the antiestrogen tamoxifen with a PARP1 inhibitor (PARPi) would sensitize tamoxifen resistant cells to tamoxifen therapy. In tamoxifen-resistant vs. -sensitive breast cancer cells, oxidative stress and PARP1 overexpression were increased. Furthermore, differential PARylation of ERα was observed in tamoxifen-resistant versus -sensitive cells, and ERα PARylation was increased by tamoxifen treatment. Loss of ERα PARylation following treatment with a PARP inhibitor (talazoparib) augmented tamoxifen sensitivity and decreased localization of both ERα and PARP1 to ERα-target genes. Co-administration of talazoparib plus tamoxifen increased DNA damage accumulation and decreased cell survival in a dose-dependent manner. The ability of PARPi to overcome tamoxifen resistance was dependent on ERα, as lack of ERα-mediated estrogen signaling expression and showed no response to tamoxifen-PARPi treatment. These results correlate ERα PARylation with tamoxifen resistance and indicate a novel mechanism-based approach to overcome tamoxifen resistance in ER+ breast cancer.

The role of mitochondrial estrogen receptor β in relapse of breast cancer.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e12540-e12540
Author(s):  
Tae Hyun Kim ◽  
In-Sung Song ◽  
Jin Han
Keyword(s):  
Breast Cancer ◽  
Stem Cells ◽  
Estrogen Receptor ◽  
Cancer Stem Cells ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Tamoxifen Treatment ◽  
Significant Difference ◽  
Mcf 7

e12540 Background: Breast cancer is the most common non-skin cancer in women. Breast cancers are heterogeneous, and treatment by subgroup based on hormone receptor and HER2 made a significant difference in clinical outcomes. Several studies have reported that estrogen receptor beta (ERβ) decreases during tumor development in the breast epithelium. However, the role of ERβ in relapse and metastasis of breast cancer is poorly understood. Methods: In this study, we retrospectively studied 30 case breast carcinomas divided luminal, HER2, and triple negative subtype. Among them, patients relapsed within 5 years are 6 cases. The expression of ERβ gene in breast cancer tissues (30 cases) was estimated using a quantitative PCR, and other marker (ERα, HER2, PR etc) was measured anonymously in formalin-fixed paraffin-embedded tumor sections, by using specific antibodies. Results: A low level of ERβ expression and mitochondrial translocation of ERβ was associated with relapse/metastasis of breast cancer. The ERβ depletion resulted in resistance in response to tamoxifen treatment of MCF-7 breast cancer cells. Conversely, the overexpression of mitochondrial ERβ enhanced the cell death by treatment of tamoxifen in MCF-7 cells. We found that ERβ localizes to the mitochondria via the interaction with Grp75 and improves mitochondrial oxygen consumption rate and ATP production in breast cancer cells. Finally, we showed that ERβ level was a low in the breast cancer stem cells (CD24-CD44+ cells) compared with breast non-cancer stem cells (CD24+CD44- cells), whereas ERα level was a high. The overexpression of mitochondrial ERβ contribute to a decrease of sphere formation showing a tumorigenic ability. Conclusions: The mitochondrial ERβ contribute to suppress survival and stemness of cancer stem cells for relapse/metastasis, promising to the development of novel strategies for the treatment of breast cancer patients.

The expression level of S100A4 protein affects the migration activity of breast cancer cells

2019 ◽  
Vol 485 (2) ◽  
pp. 226-228
Author(s):  
E. A. Dukhanina ◽  
T. N. Portseva ◽  
A. P. Kotnova ◽  
E. V. Pankratova ◽  
S. G. Georgieva
Keyword(s):  
Breast Cancer ◽  
Protein Content ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Culture Medium ◽  
Expression Level ◽  
Intracellular Level ◽  
Migration Activity ◽  
S100a4 Protein ◽  
Exogenous Protein

Reduced expression of S100A4 protein metastasis marker in tripletnegative breast cancer cells (BC) MDA MB 231 leads to a decrease in the migratory ability of cells and increases the sensitivity of modified cells to docetaxel therapy. Cells capable of migration differ from immobile cells in the S100A4 protein content inside the cell, and this difference is preserved after the cells are treated with agents that lower the intracellular level of S100A4. The presence of exogenous protein S100A4 in the culture medium reduces the protein content in breast cancer cells. The results of the research indicate that the ability of BC cells to migrate depends on the concentration of S100A4 protein inside the cell.

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