scholarly journals Blockade of CDK7 Reverses Endocrine Therapy Resistance in Breast Cancer

2020 ◽  
Vol 21 (8) ◽  
pp. 2974 ◽  
Author(s):  
Yasmin M. Attia ◽  
Samia A. Shouman ◽  
Salama A. Salama ◽  
Cristina Ivan ◽  
Abdelrahman M. Elsayed ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Volume ◽  
Apoptotic Cell ◽  
Therapy Resistance ◽  
Tamoxifen Treatment ◽  
Clinical Samples ◽  
Breast Cancer Cell Lines ◽  
Breast Cancer Patients

Cyclin-dependent kinase (CDK)-7 inhibitors are emerging as promising drugs for the treatment of different types of cancer that show chemotherapy resistance. Evaluation of the effects of CDK7 inhibitor, THZ1, alone and combined with tamoxifen is of paramount importance. Thus, in the current work, we assessed the effects of THZ1 and/or tamoxifen in two estrogen receptor-positive (ER+) breast cancer cell lines (MCF7) and its tamoxifen resistant counterpart (LCC2) in vitro and in xenograft mouse models of breast cancer. Furthermore, we evaluated the expression of CDK7 in clinical samples from breast cancer patients. Cell viability, apoptosis, and genes involved in cell cycle regulation and tamoxifen resistance were determined. Tumor volume and weight, proliferation marker (Ki67), angiogenic marker (CD31), and apoptotic markers were assayed. Bioinformatic data indicated CDK7 expression was associated with negative prognosis, enhanced pro-oncogenic pathways, and decreased response to tamoxifen. Treatment with THZ1 enhanced tamoxifen-induced cytotoxicity, while it inhibited genes involved in tumor progression in MCF-7 and LCC2 cells. In vivo, THZ1 boosted the effect of tamoxifen on tumor weight and tumor volume, reduced Ki67 and CD31 expression, and increased apoptotic cell death. Our findings identify CDK7 as a possible therapeutic target for breast cancer whether it is sensitive or resistant to tamoxifen therapy.

Targeting PSG1 to enhance chemotherapeutic efficacy: new application for anti-coagulant the dicumarol

2016 ◽  
Vol 130 (24) ◽  
pp. 2267-2276 ◽  
Author(s):  
Dong-xu He ◽  
Feng Gu ◽  
Jian Wu ◽  
Xiao-Ting Gu ◽  
Chun-Xiao Lu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Patients ◽  
Transforming Growth Factor ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Transforming Growth Factor Β ◽  
Clinical Samples ◽  
Breast Cancer Patients

Chemotherapeutic response is critical for the successful treatment and good prognosis in cancer patients. In this study, we analysed the gene expression profiles of preoperative samples from oestrogen receptor (ER)-negative breast cancer patients with different responses to taxane-anthracycline-based (TA-based) chemotherapy, and identified a group of genes that was predictive. Pregnancy specific beta-1-glycoprotein 1 (PSG1) played a central role within signalling pathways of these genes. Inhibiting PSG1 can effectively reduce chemoresistance via a transforming growth factor-β (TGF-β)-related pathway in ER-negative breast cancer cells. Drug screening then identified dicumarol (DCM) to target the PSG1 and inhibit chemoresistance to TA-based chemotherapy in vitro, in vivo, and in clinical samples. Taken together, this study highlights PSG1 as an important mediator of chemoresistance, whose effect could be diminished by DCM.

scholarly journals Anti-estrogenic and anti-aromatase activities of citrus peels major compounds in breast cancer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dina M. El-Kersh ◽  
Shahira M. Ezzat ◽  
Maha M. Salama ◽  
Engy A. Mahrous ◽  
Yasmeen M. Attia ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogenic Activity ◽  
Ethanolic Extract ◽  
Estrogen Signaling ◽  
Breast Cancer Cell Lines ◽  
Breast Cancer Patients ◽  
Antitumor Potential ◽  
Citrus Peels

AbstractEstrogen signaling is crucial for breast cancer initiation and progression. Endocrine-based therapies comprising estrogen receptor (ER) modulators and aromatase inhibitors remain the mainstay of treatment. This study aimed at investigating the antitumor potential of the most potent compounds in citrus peels on breast cancer by exploring their anti-estrogenic and anti-aromatase activities. The ethanolic extract of different varieties of citrus peels along with eight isolated flavonoids were screened against estrogen-dependent breast cancer cell lines besides normal cells for evaluating their safety profile. Naringenin, naringin and quercetin demonstrated the lowest IC50s and were therefore selected for further assays. In silico molecular modeling against ER and aromatase was performed for the three compounds. In vivo estrogenic and anti-estrogenic assays confirmed an anti-estrogenic activity for the isolates. Moreover, naringenin, naringin and quercetin demonstrated in vitro inhibitory potential against aromatase enzyme along with anticancer potential in vivo, as evidenced by decreased tumor volumes. Reduction in aromatase levels in solid tumors was also observed in treated groups. Overall, this study suggests an antitumor potential for naringenin, naringin and quercetin isolated from citrus peels in breast cancer via possible modulation of estrogen signaling and aromatase inhibition suggesting their use in pre- and post-menopausal breast cancer patients, respectively.

scholarly journals Notch3 inhibits cell proliferation and tumorigenesis and predicts better prognosis in breast cancer through transactivating PTEN

2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Yong-Qu Zhang ◽  
Yuan-Ke Liang ◽  
Yang Wu ◽  
Min Chen ◽  
Wei-Ling Chen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Malignant Tumors ◽  
Breast Cancer Cell Lines ◽  
Breast Cancer Patients ◽  
Loss Of Function ◽  
Ki 67 ◽  
Cancer Subtypes

AbstractNotch receptors (Notch1–4) play critical roles in tumorigenesis and metastasis of malignant tumors, including breast cancer. Although abnormal Notch activation is related to various tumors, the importance of single receptors and their mechanism of activation in distinct breast cancer subtypes are still unclear. Previous studies by our group demonstrated that Notch3 may inhibit the emergence and progression of breast cancer. PTEN is a potent tumor suppressor, and its loss of function is sufficient to promote the occurrence and progression of tumors. Intriguingly, numerous studies have revealed that Notch1 is involved in the regulation of PTEN through its binding to CBF-1, a Notch transcription factor, and the PTEN promoter. In this study, we found that Notch3 and PTEN levels correlated with the luminal phenotype in breast cancer cell lines. Furthermore, we demonstrated that Notch3 transactivated PTEN by binding CSL-binding elements in the PTEN promoter and, at least in part, inhibiting the PTEN downstream AKT-mTOR pathway. Notably, Notch3 knockdown downregulated PTEN and promoted cell proliferation and tumorigenesis. In contrast, overexpression of the Notch3 intracellular domain upregulated PTEN and inhibited cell proliferation and tumorigenesis in vitro and in vivo. Moreover, inhibition or overexpression of PTEN partially reversed the promotion or inhibition of cell proliferation induced by Notch3 alterations. In general, Notch3 expression positively correlated with elevated expression of PTEN, ER, lower Ki-67 index, and incidence of involved node status and predicted better recurrence-free survival in breast cancer patients. Therefore, our findings demonstrate that Notch3 inhibits breast cancer proliferation and suppresses tumorigenesis by transactivating PTEN expression.

scholarly journals IDO Inhibition Facilitates Antitumor Immunity of Vγ9Vδ2 T Cells in Triple-Negative Breast Cancer

2021 ◽  
Vol 11 ◽  
Author(s):  
Peng Li ◽  
Ruan Wu ◽  
Ke Li ◽  
Wenhui Yuan ◽  
Chuqian Zeng ◽  
...  
Keyword(s):  
Breast Cancer ◽  
T Cells ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Γδ T Cells ◽  
Clinical Samples ◽  
Breast Cancer Patients ◽  
Vγ9vδ2 T Cells

Triple-negative breast cancer (TNBC) escape from immune-mediated destruction was associated with immunosuppressive responses that dampened the activation of tumor-infiltrating CD8 and γδ T cells. TNBC had a higher level of programmed cell death 1-ligand 1 (PD-L1) and indoleamine 2,3-dioxygenase (IDO), compared with other breast cancer subtypes. But, clinical studies have revealed that the response rate of PD-1/PD-L1 antibody for TNBC treatment was relatively low. However, the antitumor responses of human Vγ9Vδ2 T cells or IDO inhibitor in TNBC treatment are unknown. In this study, we found that IDO1 and PD-L1 were highly expressed in TNBC patients. Analysis of the clinical samples demonstrated that Vγ9Vδ2 T cells became exhausted in triple-negative breast cancer patients. And Vγ9Vδ2 T cells combined with αPD-L1 could not further enhance their antitumor responses in vitro and in vivo. However, Vγ9Vδ2 T cells combined with IDO1 inhibitor 1-Methyl-L-tryptophan (1-MT) or Lindrostat showed substantial inhibitory effects on MDA-MB-231 tumor cells. Finally, we found that IDO1 inhibitor promoted T cell’s cytotoxicity by enhancing perforin production. These results converged to suggest the potential application of Vγ9Vδ2 T cells treated with IDO1 inhibitor for TNBC therapy.

scholarly journals LncRNA DILA1 inhibits Cyclin D1 degradation and contributes to tamoxifen resistance in breast cancer

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Qianfeng Shi ◽  
Yudong Li ◽  
Shunying Li ◽  
Liang Jin ◽  
Hongna Lai ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cyclin D1 ◽  
Cancer Cell ◽  
D1 Protein ◽  
Tamoxifen Resistance ◽  
Tamoxifen Treatment ◽  
Breast Cancer Patients ◽  
Cyclin D1 Protein

Abstract Cyclin D1 is one of the most important oncoproteins that drives cancer cell proliferation and associates with tamoxifen resistance in breast cancer. Here, we identify a lncRNA, DILA1, which interacts with Cyclin D1 and is overexpressed in tamoxifen-resistant breast cancer cells. Mechanistically, DILA1 inhibits the phosphorylation of Cyclin D1 at Thr286 by directly interacting with Thr286 and blocking its subsequent degradation, leading to overexpressed Cyclin D1 protein in breast cancer. Knocking down DILA1 decreases Cyclin D1 protein expression, inhibits cancer cell growth and restores tamoxifen sensitivity both in vitro and in vivo. High expression of DILA1 is associated with overexpressed Cyclin D1 protein and poor prognosis in breast cancer patients who received tamoxifen treatment. This study shows the previously unappreciated importance of post-translational dysregulation of Cyclin D1 contributing to tamoxifen resistance in breast cancer. Moreover, it reveals the novel mechanism of DILA1 in regulating Cyclin D1 protein stability and suggests DILA1 is a specific therapeutic target to downregulate Cyclin D1 protein and reverse tamoxifen resistance in treating breast cancer.

scholarly journals Let-7d Inhibits Growth and Metastasis in Breast Cancer by Targeting Jab1/Cops5

2018 ◽  
Vol 47 (5) ◽  
pp. 2126-2135 ◽  
Author(s):  
Yongchang Wei ◽  
Guohong Liu ◽  
Balu Wu ◽  
Yufen Yuan ◽  
Yunbao Pan
Keyword(s):  
Breast Cancer ◽  
Cancer Patients ◽  
Tumor Development ◽  
Luciferase Reporter ◽  
Breast Cancer Cell Lines ◽  
Breast Cancer Patients ◽  
In Vivo Experiments ◽  
Cancer Tissues

Background/Aims: MicroRNAs (miRNAs) regulate the expressions of cancer-related genes, and are involved in the development and progression of various human cancers. Here, we performed further analyses to determine whether let-7d is functionally linked to Jab1 in breast cancer. Methods: In situ hybridization and immunohistochemical analyses were used to determine the level of let-7d and Jab1 in breast cancer clinical specimens and its correlation with clinicopathological data. Let-7d overexpressing breast cancer cell lines combined with mouse models bearing cell-derived xenografts were used to assess the functional role of let-7d both in vitro and in vivo. Results: In this study, we found that let-7d was downregulated in breast cancer tissues, coupled with the elevations of Jab1 protein expressions, compared with paired adjacent noncancerous breast tissues. Let-7d overexpression significantly suppressed the proliferation and invasion in MCF-7 and MDA-MB-231 cells. Dual luciferase reporter assay indicated that Jab1 was the direct target of let-7d. Stepwise studies from in vitro and in vivo experiments indicated that let-7d overexpression inhibited cell growth and decreased Jab1 expressions in breast cancer cells and nude mice tumor tissues. Statistical analyses demonstrated that breast cancer patients with low levels of let-7d or high levels of Jab1 had a significant correlation with worse prognosis. Conclusion: These findings provide novel insights into molecular mechanism of let-7d and Jab1 in tumor development and progression of breast cancer, and thus let-7d/Jab1 are novel potential therapeutic targets for breast cancer patients.

scholarly journals LPTO-06. A NOVEL BRAIN-PERMEANT CHEMOTHERAPEUTIC AGENT FOR THE TREATMENT OF BREAST CANCER LEPTOMENINGEAL METASTASIS

2019 ◽  
Vol 1 (Supplement_1) ◽  
pp. i7-i7
Author(s):  
Jiaojiao Deng ◽  
Sophia Chernikova ◽  
Wolf-Nicolas Fischer ◽  
Kerry Koller ◽  
Bernd Jandeleit ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Brain Tumors ◽  
Cell Lines ◽  
Chemotherapeutic Agent ◽  
Leptomeningeal Metastasis ◽  
Breast Cancer Cell Lines ◽  
Normal Brain ◽  
Breast Cancers

Abstract Leptomeningeal metastasis (LM), a spread of cancer to the cerebrospinal fluid and meninges, is universally and rapidly fatal due to poor detection and no effective treatment. Breast cancers account for a majority of LMs from solid tumors, with triple-negative breast cancers (TNBCs) having the highest propensity to metastasize to LM. The treatment of LM is challenged by poor drug penetration into CNS and high neurotoxicity. Therefore, there is an urgent need for new modalities and targeted therapies able to overcome the limitations of current treatment options. Quadriga has discovered a novel, brain-permeant chemotherapeutic agent that is currently in development as a potential treatment for glioblastoma (GBM). The compound is active in suppressing the growth of GBM tumor cell lines implanted into the brain. Radiolabel distribution studies have shown significant tumor accumulation in intracranial brain tumors while sparing the adjacent normal brain tissue. Recently, we have demonstrated dose-dependent in vitro and in vivo anti-tumor activity with various breast cancer cell lines including the human TNBC cell line MDA-MB-231. To evaluate the in vivo antitumor activity of the compound on LM, we used the mouse model of LM based on the internal carotid injection of luciferase-expressing MDA-MB-231-BR3 cells. Once the bioluminescence signal intensity from the metastatic spread reached (0.2 - 0.5) x 106 photons/sec, mice were dosed i.p. twice a week with either 4 or 8 mg/kg for nine weeks. Tumor growth was monitored by bioluminescence. The compound was well tolerated and caused a significant delay in metastatic growth resulting in significant extension of survival. Tumors regressed completely in ~ 28 % of treated animals. Given that current treatments for LM are palliative with only few studies reporting a survival benefit, Quadriga’s new agent could be effective as a therapeutic for both primary and metastatic brain tumors such as LM. REF: https://onlinelibrary.wiley.com/doi/full/10.1002/pro6.43

Targeting PKM2 promotes chemosensitivity of breast cancer cells in vitro and in vivo

2021 ◽  
pp. 1-10
Author(s):  
Yu Wang ◽  
Han Zhao ◽  
Ping Zhao ◽  
Xingang Wang
Keyword(s):  
Breast Cancer ◽  
Neoadjuvant Chemotherapy ◽  
Cancer Cells ◽  
Cancer Patients ◽  
Poor Prognosis ◽  
Breast Cancer Cells ◽  
Breast Cancer Patients ◽  
Cancer Tissues

BACKGROUND: Pyruvate kinase M2 (PKM2) was overexpressed in many cancers, and high PKM2 expression was related with poor prognosis and chemoresistance. OBJECTIVE: We investigated the expression of PKM2 in breast cancer and analyzed the relation of PKM2 expression with chemotherapy resistance to the neoadjuvant chemotherapy (NAC). We also investigated whether PKM2 could reverse chemoresistance in breast cancer cells in vitro and in vivo. METHODS: Immunohistochemistry (IHC) was performed in 130 surgical resected breast cancer tissues. 78 core needle biopsies were collected from breast cancer patients before neoadjuvant chemotherapy. The relation of PKM2 expression and multi-drug resistance to NAC was compared. The effect of PKM2 silencing or overexpression on Doxorubicin (DOX) sensitivity in the MCF-7 cells in vitro and in vivo was compared. RESULTS: PKM2 was intensively expressed in breast cancer tissues compared to adjacent normal tissues. In addition, high expression of PKM2 was associated with poor prognosis in breast cancer patients. The NAC patients with high PKM2 expression had short survival. PKM2 was an independent prognostic predictor for surgical resected breast cancer and NAC patients. High PKM2 expression was correlated with neoadjuvant treatment resistance. High PKM2 expression significantly distinguished chemoresistant patients from chemosensitive patients. In vitro and in vivo knockdown of PKM2 expression decreases the resistance to DOX in breast cancer cells in vitro and tumors in vivo. CONCLUSION: PKM2 expression was associated with chemoresistance of breast cancers, and could be used to predict the chemosensitivity. Furthermore, targeting PKM2 could reverse chemoresistance, which provides an effective treatment methods for patients with breast cancer.

scholarly journals Splicing factor SRSF1 promotes breast cancer progression via oncogenic splice switching of PTPMT1

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Jun-Xian Du ◽  
Yi-Hong Luo ◽  
Si-Jia Zhang ◽  
Biao Wang ◽  
Cong Chen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Progression ◽  
High Risk Group ◽  
Clinical Samples ◽  
Binding Motif ◽  
Ki 67 ◽  
Tissue Samples

Abstract Background Intensive evidence has highlighted the effect of aberrant alternative splicing (AS) events on cancer progression when triggered by dysregulation of the SR protein family. Nonetheless, the underlying mechanism in breast cancer (BRCA) remains elusive. Here we sought to explore the molecular function of SRSF1 and identify the key AS events regulated by SRSF1 in BRCA. Methods We conducted a comprehensive analysis of the expression and clinical correlation of SRSF1 in BRCA based on the TCGA dataset, Metabric database and clinical tissue samples. Functional analysis of SRSF1 in BRCA was conducted in vitro and in vivo. SRSF1-mediated AS events and their binding motifs were identified by RNA-seq, RNA immunoprecipitation-PCR (RIP-PCR) and in vivo crosslinking followed by immunoprecipitation (CLIP), which was further validated by the minigene reporter assay. PTPMT1 exon 3 (E3) AS was identified to partially mediate the oncogenic role of SRSF1 by the P-AKT/C-MYC axis. Finally, the expression and clinical significance of these AS events were validated in clinical samples and using the TCGA database. Results SRSF1 expression was consistently upregulated in BRCA samples, positively associated with tumor grade and the Ki-67 index, and correlated with poor prognosis in a hormone receptor-positive (HR+) cohort, which facilitated proliferation, cell migration and inhibited apoptosis in vitro and in vivo. We identified SRSF1-mediated AS events and discovered the SRSF1 binding motif in the regulation of splice switching of PTPMT1. Furthermore, PTPMT1 splice switching was regulated by SRSF1 by binding directly to its motif in E3 which partially mediated the oncogenic role of SRSF1 by the AKT/C-MYC axis. Additionally, PTPMT1 splice switching was validated in tissue samples of BRCA patients and using the TCGA database. The high-risk group, identified by AS of PTPMT1 and expression of SRSF1, possessed poorer prognosis in the stage I/II TCGA BRCA cohort. Conclusions SRSF1 exerts oncogenic roles in BRCA partially by regulating the AS of PTPMT1, which could be a therapeutic target candidate in BRCA and a prognostic factor in HR+ BRCA patient.

scholarly journals A novel hypoxic long noncoding RNA KB-1980E6.3 maintains breast cancer stem cell stemness via interacting with IGF2BP1 to facilitate c-Myc mRNA stability

Oncogene ◽  
2021 ◽  
Author(s):  
Pengpeng Zhu ◽  
Fang He ◽  
Yixuan Hou ◽  
Gang Tu ◽  
Qiao Li ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Long Noncoding Rna ◽  
Noncoding Rna ◽  
Underlying Mechanism ◽  
Rapid Expansion ◽  
Breast Cancer Patients ◽  
Coding Region ◽  
Signaling Axis

AbstractThe hostile hypoxic microenvironment takes primary responsibility for the rapid expansion of breast cancer tumors. However, the underlying mechanism is not fully understood. Here, using RNA sequencing (RNA-seq) analysis, we identified a hypoxia-induced long noncoding RNA (lncRNA) KB-1980E6.3, which is aberrantly upregulated in clinical breast cancer tissues and closely correlated with poor prognosis of breast cancer patients. The enhanced lncRNA KB-1980E6.3 facilitates breast cancer stem cells (BCSCs) self-renewal and tumorigenesis under hypoxic microenvironment both in vitro and in vivo. Mechanistically, lncRNA KB-1980E6.3 recruited insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) to form a lncRNA KB-1980E6.3/IGF2BP1/c-Myc signaling axis that retained the stability of c-Myc mRNA through increasing binding of IGF2BP1 with m6A-modified c-Myc coding region instability determinant (CRD) mRNA. In conclusion, we confirm that lncRNA KB-1980E6.3 maintains the stemness of BCSCs through lncRNA KB-1980E6.3/IGF2BP1/c-Myc axis and suggest that disrupting this axis might provide a new therapeutic target for refractory hypoxic tumors.

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