scholarly journals Activated STAT3 Is a Novel Regulator of the XRCC1 Promoter and Selectively Increases XRCC1 Protein Levels in Triple Negative Breast Cancer

2021 ◽  
Vol 22 (11) ◽  
pp. 5475
Author(s):  
Griffin Wright ◽  
Manoj Sonavane ◽  
Natalie R. Gassman
Keyword(s):  
Breast Cancer ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Excision Repair ◽  
Strand Break ◽  
Xrcc1 Gene ◽  
Single Strand Break ◽  
Expression Levels ◽  
Constitutive Activation ◽  
Gene And Protein Expression

Base Excision Repair (BER) addresses base lesions and abasic sites induced by exogenous and endogenous stressors. X-ray cross complementing group 1 (XRCC1) functions as a scaffold protein in BER and single-strand break repair (SSBR), facilitating and coordinating repair through its interaction with a host of critical repair proteins. Alterations of XRCC1 protein and gene expression levels are observed in many cancers, including colorectal, ovarian, and breast cancer. While increases in the expression level of XRCC1 are reported, the transcription factors responsible for this up-regulation are not known. In this study, we identify the signal transducer and activator of transcription 3 (STAT3) as a novel regulator of XRCC1 through chromatin immunoprecipitation. Activation of STAT3 through phosphorylation at Y705 by cytokine (IL-6) signaling increases the expression of XRCC1 and the occupancy of STAT3 within the XRCC1 promoter. In triple negative breast cancer, the constitutive activation of STAT3 upregulates XRCC1 gene and protein expression levels. Increased expression of XRCC1 is associated with aggressiveness and resistance to DNA damaging chemotherapeutics. Thus, we propose that activated STAT3 regulates XRCC1 under stress and growth conditions, but constitutive activation in cancers results in dysregulation of XRCC1 and subsequently BER and SSBR.

scholarly journals XRCC1 deficient triple negative breast cancers are sensitive to ATR, ATM and Wee1 inhibitor either alone or in combination with olaparib

2020 ◽  
Vol 12 ◽  
pp. 175883592097420
Author(s):  
Reem Ali ◽  
Adel Alblihy ◽  
Michael S. Toss ◽  
Mashael Algethami ◽  
Rabab Al Sunni ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Dna Repair ◽  
Triple Negative ◽  
Germ Line ◽  
Synthetic Lethality ◽  
Excision Repair ◽  
Parp Inhibitor ◽  
Strand Break ◽  
Breast Cancers ◽  
Single Strand Break

Background: PARP inhibitor (PARPi) monotherapy is a new strategy in BRCA germ-line deficient triple negative breast cancer (TNBC). However, not all patients respond, and the development of resistance limits the use of PARPi monotherapy. Therefore, the development of alternative synthetic lethality strategy, including in sporadic TNBC, is a priority. XRCC1, a key player in base excision repair, single strand break repair, nucleotide excision repair and alternative non-homologous end joining, interacts with PARP1 and coordinates DNA repair. ATR, ATM and Wee1 have essential roles in DNA repair and cell cycle regulation. Methods: Highly selective inhibitors of ATR (AZD6738), ATM (AZ31) and Wee1 (AZD1775) either alone or in combination with olaparib were tested for synthetic lethality in XRCC1 deficient TNBC or HeLa cells. Clinicopathological significance of ATR, ATM or Wee1 co-expression in XRCC1 proficient or deficient tumours was evaluated in a large cohort of 1650 human breast cancers. Results: ATR (AZD6738), ATM (AZ31) or Wee1 (AZD1775) monotherapy was selectively toxic in XRCC1 deficient cells. Selective synergistic toxicity was evident when olaparib was combined with AZD6738, AZ31 or AZD1775. The most potent synergistic interaction was evident with the AZD6738 and olaparib combination therapy. In clinical cohorts, ATR, ATM or Wee1 overexpression in XRCC1 deficient breast cancer was associated with poor outcomes. Conclusion: XRCC1 stratified DNA repair targeted combinatorial approach is feasible and warrants further clinical evaluation in breast cancer.

scholarly journals The BIRC Family Genes Expression in Patients with Triple Negative Breast Cancer

2021 ◽  
Vol 22 (4) ◽  
pp. 1820
Author(s):  
Anna Makuch-Kocka ◽  
Janusz Kocki ◽  
Anna Brzozowska ◽  
Jacek Bogucki ◽  
Przemysław Kołodziej ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Clinical Data ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Lymphatic Vessels ◽  
The Cancer Genome Atlas ◽  
Expression Level ◽  
Cancer Tissue ◽  
Expression Levels

The BIRC (baculoviral IAP repeat-containing; BIRC) family genes encode for Inhibitor of Apoptosis (IAP) proteins. The dysregulation of the expression levels of the genes in question in cancer tissue as compared to normal tissue suggests that the apoptosis process in cancer cells was disturbed, which may be associated with the development and chemoresistance of triple negative breast cancer (TNBC). In our study, we determined the expression level of eight genes from the BIRC family using the Real-Time PCR method in patients with TNBC and compared the obtained results with clinical data. Additionally, using bioinformatics tools (Ualcan and The Breast Cancer Gene-Expression Miner v4.5 (bc-GenExMiner v4.5)), we compared our data with the data in the Cancer Genome Atlas (TCGA) database. We observed diverse expression pattern among the studied genes in breast cancer tissue. Comparing the expression level of the studied genes with the clinical data, we found that in patients diagnosed with breast cancer under the age of 50, the expression levels of all studied genes were higher compared to patients diagnosed after the age of 50. We observed that in patients with invasion of neoplastic cells into lymphatic vessels and fat tissue, the expression levels of BIRC family genes were lower compared to patients in whom these features were not noted. Statistically significant differences in gene expression were also noted in patients classified into three groups depending on the basis of the Scarff-Bloom and Richardson (SBR) Grading System.

scholarly journals LncRNA DLX6-AS1 Contributes to Epithelial–Mesenchymal Transition and Cisplatin Resistance in Triple-negative Breast Cancer via Modulating Mir-199b-5p/Paxillin Axis

2020 ◽  
Vol 29 ◽  
pp. 096368972092998 ◽  
Author(s):  
Chuang Du ◽  
Yan Wang ◽  
Yingying Zhang ◽  
Jianhua Zhang ◽  
Linfeng Zhang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Drug Resistance ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Cisplatin Resistance ◽  
Epithelial Mesenchymal Transition ◽  
Mesenchymal Transition ◽  
Expression Levels

Triple-negative breast cancer (TNBC) is one of the most aggressive cancer types with high recurrence, metastasis, and drug resistance. Recent studies report that long noncoding RNAs (lncRNAs)-mediated competing endogenous RNAs (ceRNA) play an important role in tumorigenesis and drug resistance of TNBC. Although elevated lncRNA DLX6 antisense RNA 1 (DLX6-AS1) has been observed to promote carcinogenesis in various cancers, the role in TNBC remained unclear. In this study, expression levels of DLX6-AS1 were increased in TNBC tissues and cell lines when compared with normal tissues or breast fibroblast cells which were determined by quantitative real-time PCR (RT-qPCR). Then, CCK-8 assay, cell colony formation assay and western blot were performed in CAL-51 cells transfected with siRNAs of DLX6-AS1 or MDA-MB-231 cells transfected with DLX6-AS1 over expression plasmids. Knock down of DLX6-AS1 inhibited cell proliferation, epithelial-mesenchymal transition (EMT), decreased expression levels of BCL2 apoptosis regulator (Bcl-2), Snail family transcriptional repressor 1 (Snail) as well as N-cadherin and decreased expression levels of cleaved caspase-3, γ-catenin as well as E-cadherin, while up regulation of DLX6-AS1 had the opposite effect. Besides, knockdown of DLX6-AS1 in CAL-51 cells or up regulation of DLX6-AS1 in MDA-MB-231 cells also decreased or increased cisplatin resistance of those cells analyzed by MTT assay. Moreover, by using dual luciferase reporter assay, RNA immunoprecipitation and RNA pull down assay, a ceRNA which was consisted by lncRNA DLX6-AS1, microRNA-199b-5p (miR-199b-5p) and paxillin (PXN) was identified. And DLX6-AS1 function through miR-199b-5p/PXN in TNBC cells. Finally, results of xenograft experiments using nude mice showed that DLX6-AS1 regulated cell proliferation, EMT and cisplatin resistance by miR-199b-5p/PXN axis in vivo. In brief, DLX6-AS1 promoted cell proliferation, EMT, and cisplatin resistance through miR-199b-5p/PXN signaling in TNBC in vitro and in vivo.

scholarly journals The expression and clinical significance of GADD45A in breast cancer patients

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5344 ◽  
Author(s):  
Junnan Wang ◽  
Yiran Wang ◽  
Fei Long ◽  
Fengshang Yan ◽  
Ning Wang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Cancer Patients ◽  
Clinical Significance ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Breast Cancer Patients ◽  
Ki 67 ◽  
Expression Levels ◽  
Cancer Tissues

BackgroundGrowth arrest and DNA-damage-inducible protein 45 alpha (GADD45A) was previously found to be associated with risk of several kinds of human tumors. Here, we studied the expression and clinical significance of GADD45A in breast cancer.MethodsWe performed an immunohistochemical study of GADD45A protein from 419 breast cancer tissues and 116 adjacent non-neoplastic tissues.ResultsSignificantly high GADD45A expression were observed in breast cancer tissues compared with adjacent non-neoplastic tissues (P < 0.001) and were independently correlative with estrogen receptor negative (P = 0.028) and high Ki-67 index (P < 0.001). Kaplan–Meier survival analysis revealed that patients with high GADD45A expression levels had a worse long-term prognosis in triple negative breast cancer (P = 0.041), but it was not an independent prognostic factor in multivariate analysis (P = 0.058).ConclusionsGADD45A expression levels are significantly correlative with estrogen receptor status and Ki-67 index in human breast cancer. Patients with triple negative breast cancer might be stratified into high risk and low risk groups based on the GADD45A expression levels.

scholarly journals LncRNA NRON down-regulates lncRNA snaR and inhibits cancer cell proliferation in TNBC

2019 ◽  
Vol 39 (5) ◽  
Author(s):  
Limin Niu ◽  
Qingxia Fan ◽  
Min Yan ◽  
Liuxing Wang
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Cancer Cell ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Cancer Cell Proliferation ◽  
Tat Protein ◽  
Expression Levels ◽  
Clinical Stages ◽  
Hiv 1

Abstract NRON mediates the degradation of tat protein to participate in HIV-1 infection. Interestingly, our study observed the down-regulation of NRON in triple-negative breast cancer (TNBC) tissues compared with paired adjacent healthy tissues. In contrast, lncRNA snaR was up-regulated in TNBC tissues and was inversely correlated with NRON. Expression levels of snaR increased, while expression levels of NRON decreased along with the increase of clinical stages. The snaR overexpression resulted in promoted cancer cell proliferation but did not significantly affect NRON expression. NRON overexpression inhibited cancer cell proliferation and down-regulated snaR. The snaR overexpression reduced the effects of NRON overexpression. We therefore conclude that NRON may down-regulate lncRNA snaR to inhibit cancer cell proliferation in TNBC.

scholarly journals High ERK Protein Expression Levels Correlate with Shorter Survival in Triple‐Negative Breast Cancer Patients

2012 ◽  
Vol 17 (6) ◽  
pp. 766-774 ◽  
Author(s):  
Chandra Bartholomeusz ◽  
Ana M. Gonzalez‐Angulo ◽  
Ping Liu ◽  
Naoki Hayashi ◽  
Ana Lluch ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Protein Expression ◽  
Cancer Patients ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Breast Cancer Patients ◽  
Expression Levels

Functional hotness score based on three genes predicts long-term survival of triple-negative breast cancer independent from tumor mutational burden.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e12583-e12583
Author(s):  
Eriko Katsuta ◽  
Li Yan ◽  
Mateusz Opyrchal ◽  
Pawel Kalinski ◽  
Kazuaki Takabe
Keyword(s):  
Breast Cancer ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Metastatic Breast ◽  
Cancer Prognosis ◽  
Breast Cancer Patients ◽  
Term Survival ◽  
Expression Levels ◽  
Cancer Immunity ◽  
Anti Cancer

e12583 Background: Cytotoxic T-lymphocytes (CTLs) infiltration into tumor is a positive prognostic factor in breast cancer. Infiltration of CTLs are believed to be driven by mutation-induced neoantigens, thus, higher tumor mutation burden (TMB) is considered an important predictor of tumor immunogenicity and response to immunotherapy, but the association between intratumoral CTL counts and TMB in the overall cancer prognosis remains unclear. Methods: Utilizing publicly available breast cancer cohorts, we established Functional Hotness Score (FHS), based on CD8A, GZMB and CXCL10 gene expression levels of bulk tumors. The associations of FHS and breast cancer patient prognosis as well as distinct immunity markers were analyzed. Results: Breast cancer patients with high-FHS tumors demonstrated significantly better survival. FHS was lower in metastatic breast cancer. Among breast cancer subtypes, triple-negative breast cancer (TNBC) showed the highest FHS. FHS predicted patient survival not in hormone receptor (HR)-positive but in HR-negative, especially TNBCs. The high-FHS TNBCs enhanced not only CD8+ T cell infiltration, but also a broader type-1 anti-cancer immunity. The patients with the high-FHS patients showed better prognosis not only in high-TMB tumors but also in low-TMB TNBCs. The combination of high-TMB with high-FHS identified the unique subset of patients who did not recur over time. Conclusions: In conclusion, TNBCs with high-FHS based on the expression levels of CD8A, GZMB and CXCL10 showed improved prognosis with higher anti-cancer immunity regardless of TMB, and constituting an independent prognostic marker of survival, particularly robust when combined with TMB.

scholarly journals MiR-212-5p Suppresses the Epithelial-Mesenchymal Transition in Triple-Negative Breast Cancer by Targeting Prrx2

2017 ◽  
Vol 44 (5) ◽  
pp. 1785-1795 ◽  
Author(s):  
Zhi-Dong Lv ◽  
Dong-Xia Yang ◽  
Xiang-Ping Liu ◽  
Li-Ying Jin ◽  
Xin-Gang Wang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Progression ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Ectopic Expression ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Lymph Node Status ◽  
Mesenchymal Transition ◽  
Expression Levels

Background/Aims: Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype. Our study investigated the functional role of miR-212-5p in TNBC. Methods: Realtime PCR was used to quantify miR-212-5p expression levels in 30 paired TNBC samples and adjacent normal tissues. Wound healing and Transwell assays were used to evaluate the effects of miR-212-5p expression on the invasiveness of TNBC cells. Luciferase reporter and Western blot assays were used to verify whether the mRNA encoding Prrx2 is a major target of miR-212-5p. Results: MiR-212-5p was downregulated in TNBC, and its expression levels were related to tumor size, lymph node status and vascular invasion in breast cancer. We also observed that the miR-212-5p expression level was significantly correlated with a better prognosis in TNBC. Ectopic expression of miR-212-5p induced upregulation of E-cadherin expression and downregulation of vimentin expression. The expression of miR212-5p also suppressed the migration and invasion capacity of mesenchymal-like cancer cells accompanied by a morphological shift towards the epithelial phenotype. Moreover, our study observed that miR-212-5p overexpression significantly suppressed Prrx2 by targeting its 3’-untranslated region (3’-UTR) region, and Prrx2 overexpression partially abrogated miR-212-5p-mediated suppression. Conclusions: Our study demonstrated that miR-212-5p inhibits TNBC from acquiring the EMT phenotype by downregulating Prrx2, thereby inhibiting cell migration and invasion during cancer progression.

Sign in / Sign up

Export Citation Format

Share Document