Prognostic Biomarker For Triple-negative Breast Cancer Research Articles

Abstract 2137: Racial disparities in triple-negative breast cancer (TNBC) mortality rates in Hampton Roads Virginia and the effects of SIAH expression on prognosis

Abstract Background: While high-resolution imaging and advancements in therapies have significantly improved breast cancer survival rates, 43,170 breast cancer patients will die in the United States in 2023 alone. Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype and disproportionately affects BRCA1 mutation carriers and young black women. Black/African American (AA) patients have the highest mortality and the shortest survival of any racial/ethnic group in the US. Persistent cancer racial disparities remain due to a variety of risk factors. The SEER/CDC data show an 8% lower breast cancer incidence rate and a 41% higher mortality rate in Black/AA patients compared to their white counterparts. Methods: Chart review was conducted using Sentara MD Office/EPIC and VOA iKnowMedicine portals to update tumor relapse, metastasis, and survival in 577 TNBC patients. Supported by strong evidence in developmental, evolutionary, and cancer biology, we hypothesize that persistent EGFR/K-RAS/SIAH pathway activation is a major driving force of TNBC malignancy, racial disparity, early relapse, and high mortality. We propose to integrate SIAH expression to augment the existing clinicopathological parameters to improve patient risk stratification, therapy quantification, and relapse/survival prediction at the 1st-line neoadjuvant settings. Results: We report that cancer disparity and high mortality rates are even more pronounced in our racially-diverse communities in Hampton Roads Virginia. We discovered that SIAH is a tumor-specific, therapy-responsive, and prognostic biomarker in TNBC. High SIAH expression in residual tumors reflects tumor-driving EGFR/K-RAS/SIAH pathway activation (ON) that will predict cancer disparity, treatment resistance, early relapse, and poor survival. Low SIAH expression in residual tumors reflect EGFR/K-RAS/SIAH pathway inactivation (OFF) that will predict tumor remission and prolonged survival. Conclusion: We detect a major racial disparity of TNBC patients at Sentara-EVMS-VOA. Our local Black/AA TNBC patients have a 1.6-fold higher mortality rate than their White counterparts. Encouraged by our preliminary data, we aim to develop a SIAH-centered biomarker panel by measuring the EGFR/K-RAS/SIAH pathway activation (ON)/inactivation (OFF), and use SIAH as a new prognostic biomarker to risk stratify patients, detect cancer racial disparities, forecast tumor relapse, and predict patient survival at 1st-line neoadjuvant settings. By targeting SIAH, individualized treatments can be created to allow for increased survival rates in at risk individuals with more aggressive TNBCs. Citation Format: Claire B. Piatak, Taylor N. Drake, Ashleigh Hannah, Jonathan Baker, Caroline L. Dasom, Emily L. Breeding, Janet S. Winston, Billur Samli, Rick Jansen, Michael Danso, Richard A. Hoefer, Amy H. Tang. Racial disparities in triple-negative breast cancer (TNBC) mortality rates in Hampton Roads Virginia and the effects of SIAH expression on prognosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2137.

Prognostic value of mitophagy gene PINK1 in triple-negative breast cancer

Mitochondrial autophagy plays a crucial role in the development, progression, and treatment of triple-negative breast cancer (TNBC). A total of 43 genes related to mitochondria were obtained from the scientific literature in Pubmed. To assess the expression of these genes, they were categorized into high and low-scoring groups using the ssGSEA algorithm. Additionally, the infiltration of immune cells in the combined dataset was evaluated using the CIBERSORTx algorithm. To analyze the expression of the selected genes, one-way Cox regression analysis, along with clinical staging variables, was employed. A multifactorial Cox regression model was constructed, and a forest plot was generated to assess the predictive power of the model on the actual outcomes. The accuracy of the model was confirmed by validating the expression of the PINK1 gene and its model through immunohistochemistry. TNBC cancer was categorized into two molecular subtypes (cluster1 and cluster2) based on the MRGs. Finally, a prognostic model was developed using the PINK1 gene, which demonstrated a considerable degree of accuracy. The validity of the PINK1 gene and its model was confirmed through immunohistochemistry, indirectly indicating that PINK1 might serve as a potential therapeutic target and prognostic biomarker for TNBC.

Tumor infiltrating lymphocytes (TILs) in triple negative breast cancer

Tumor infiltrating lymphocytes (TILs) are a promising inexpensive prognostic and predictive biomarker in breast cancer. High levels of TILs are associated with improved survival and higher probability to achieve pathological complete response in triple-negative breast cancer (TNBC). To assess the level of TILs in TNBC samples and analyze the association between the level of TILs and the main pathological parameters, to identify their impact on long-term results. The study included information on 140 patients with I-III stage TNBC and estrogen receptors <10%. Tumor tissue samples at baseline biopsies were evaluated the histological type, HER2 expression, estrogen expression levels, Ki-67 and TILs. The pathological response was evaluated according to the ypTNM, Miller-Payne, and RCB classifications. The average level of TILs in biopsy specimens before NACT was 29.3±23.1%. Low levels of TILs (<10%) were defined in 21% of cases, intermediate levels (≥10% to ≤40%) in 55% of cases, and high levels (>40%) in 24% of cases. Using the two-tiered system, low TILs (≤40%) were defined in 76% and high TILs (>40%) in 24% of cases. The level of TILs was correlated with histological grade (R=0.187; p=0.027) and estrogen receptor expression level (R=0.211; p=0.012). There were no significant differences depending on the level of TILs and other pathological parameters. Three-year event-free survival (EFS) in patients with high TILs levels was 95% versus 65% in the low TILs group (p=0.037). Stromal TILs are an important prognostic biomarker in TNBC. Using a cutoff of 40%, high TILs are significantly associated with longer EFS.

Epigenomic Profiling Advises Therapeutic Potential of Leukotriene Receptor Inhibitors for a Subset of Triple-Negative Breast Tumors.

Triple-negative breast cancer (TNBC) is the most aggressive molecular subtype, with a poor survival rate compared to others subtypes. For a long time, chemotherapy was the only systemic treatment for TNBC, and the identification of actionable molecular targets might ultimately improve the prognosis for TNBC patients. We performed a genome-wide analysis of DNA methylation at CpG islands on a collection of one hundred ten breast carcinoma samples and six normal breast tissue samples using reduced representation bisulfite sequencing with the XmaI restriction enzyme (XmaI-RRBS) and identified a subset of TNBC samples with significant hypomethylation at the LTB4R/LTB4R2 genes' CpG islands, including CpG dinucleotides covered with cg12853742 and cg21886367 HumanMethylation 450K microarray probes. Abnormal DNA hypomethylation of this region in TNBC compared to normal samples was confirmed by bisulfite Sanger sequencing. Gene expression generally anticorrelates with promoter methylation, and thus, the promoter hypomethylation detected and confirmed in our study might be revealed as an indirect marker of high LTB4R/LTB4R2 expression using a simple methylation-sensitive PCR test. Analysis of RNA-seq expression and DNA methylation data from the TCGA dataset demonstrates that the expression of the LTB4R and LTB4R2 genes significantly negatively correlates with DNA methylation at both CpG sites cg12853742 (R = -0.4, p = 2.6 × 10-6; R = -0.21, p = 0.015) and cg21886367 (R = -0.45, p = 7.3 × 10-8; R = -0.24, p = 0.005), suggesting the upregulation of these genes in tumors with abnormal hypomethylation of their CpG island. Kaplan-Meier analysis using the TCGA-BRCA gene expression and clinical data revealed poorer overall survival for TNBC patients with an upregulated LTB4R. To this day, only the leukotriene inhibitor LY255283 has been tested on an MCF-7/DOX cell line, which is a luminal A breast cancer molecular subtype. Other studies compare the effects of Montelukast and Zafirlukast (inhibitors of the cysteinyl leukotriene receptor, which is different from LTB4R/LTB4R2) on the MDA-MB-231 (TNBC) cell line, with high methylation and low expression levels of LTB4R. In our study, we assess the therapeutic effects of various drugs (including leukotriene receptor inhibitors) with the DepMap gene effect and drug sensitivity data for TNBC cell lines with hypomethylated and upregulated LTB4R/LTB4R2 genes. LY255283, Minocycline, Silibinin, Piceatannol, Mitiglinide, 1-Azakenpaullone, Carbetocin, and Pim-1-inhibitor-2 can be considered as candidates for the additional treatment of TNBC patients with tumors demonstrating LTB4R/LTB4R2 hypomethylation/upregulation. Finally, our results suggest that the epigenetic status of leukotriene B4 receptors is a novel, potential, predictive, and prognostic biomarker for TNBC. These findings might improve individualized therapy for TNBC patients by introducing new therapeutic adjuncts as anticancer agents.

ZNF503 combined with GATA3 is a prognostic factor in triple-negative breast cancer

Purpose Triple-negative breast cancer (TNBC) is a subtype of breast cancer with poor prognosis. Therefore, there is an urgent need to identify prognostic markers to improve current treatment and therapeutic strategies. The transcriptional factor ZNF503 has been reported to promote aggressive breast cancer development through the down-regulation of GATA3 expression and has been identified as a candidate predictive marker. In this study, we explored whether ZNF503 and GATA3 could serve as prognostic markers independently or in combination. Material and methods We performed a survival analysis of 989 breast cancer patients from The Cancer Genome Atlas (TCGA), and validated the findings in 202 breast cancer patients from tissue microarray (TMA). Results In TCGA database, the mRNA expression of GATA3 and ZNF503 could not predict TNBC prognosis alone, though the ratio index, ZNF503/GATA3 could be a novel prognostic biomarker in TNBC patients. In TMA database, we detected the protein expression of ZNF503 and GATA3 and found that the combination of the two genes, ZNF503-GATA3, significantly improved the predictive ability of clinical outcomes. Conclusions The results indicated that the binding index of ZNF503 and GATA3 could be used as a prognostic biomarker in TNBC.

Expression of CD22 in Triple-Negative Breast Cancer: A Novel Prognostic Biomarker and Potential Target for CAR Therapy.

Triple-negative breast cancer (TNBC) accounts for 15-20% of all breast cancer cases. Due to the lack of expression of well-known molecular targets [estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2)], there is a need for more alternative treatment approaches in TNBC. Chimeric antigen receptor (CAR)-T cell-based immunotherapy treatment is one of the latest treatment technologies with outstanding therapeutic advances in the past decade, especially in the treatment of hematologic malignancies, but the therapeutic effects of CAR-T cells against solid tumors have not yet shown significant clinical benefits. Identification of highly specific CAR-T targets in solid tumors is also crucial for its successful treatment. CD22 is reported to be a multifunctional receptor that is mainly expressed on the surface of mature B-cells (lymphocytes) and is also highly expressed in most B-cell malignancies. This study aimed to investigate the expression of CD22 in TNBC. Bioinformatic analysis was performed to evaluate the expression of CD22 in breast carcinoma and normal tissues. RNA-seq data of normal and breast carcinoma patients were downloaded from The Cancer Genome Atlas (TCGA), and differential gene expression was performed using R language. Additionally, online bioinformatics web tools (GEPIA and TNM plot) were used to evaluate the expression of CD22 in breast carcinoma and normal tissues. Western blot (WB) analysis and immunofluorescence (IF) were performed to characterize the expression of CD22 in TNBC cell lines. Immunohistochemical (IHC) staining was performed on tumor specimens from 97 TNBC patients for CD22 expression. Moreover, statistical analysis was performed to analyze the association of clinical pathological parameters with CD22 expression. Correlation analysis between overall survival data of TNBC patients and CD22 expression was also performed. Differential gene expression analysis of TCGA data revealed that CD22 is among the upregulated differentially expressed genes (DEGs) with high expression in breast cancer, as compared to normal breast tissues. WB and IF analysis revealed high expression of CD22 in TNBC cell lines. IHC results also showed that approximately 62.89% (61/97) of TNBC specimens were stained positive for CD22. Cell membrane expression of CD22 was evident in 23.71% (23/97) of TNBC specimens, and 39.18% (38/97) of TNBC specimens showed cytoplasmic/membrane expression, while 37.11% (36/97) specimens were negative for CD22. Furthermore, significant associations were found between the size of tumors in TNBC patients and CD22 expression, which unveils its potential as a prognostic biomarker. No significant correlation was found between the overall survival of TNBC patients and CD22 expression. In conclusion, we demonstrated for the first time that CD22 is highly expressed in TNBC. Based on our findings, we anticipated that CD22 could be used as a prognostic biomarker in TNBC, and it might be a potential CAR-T target in TNBC for whom few therapeutic options exist. However, more large-scale studies and clinical trials will ensure its potential usefulness as a CAR-T target in TNBC.

Evaluation of CDC6 Expression in Triple-Negative Breast Cancer and its Prognostic Significance

ABSTRACT Background: Triple-negative breast cancer (TNBC) leads to high morbidity and poor prognosis due to high proliferation and metastasis. Cell division cycle 6 (CDC6) is one of the genes involved in cell division and is significantly upregulated in TNBC. There is not much information available to understand whether CDC6 can be used as a prognostic marker in TNBC. Methods: In this study, BC-GenExMiner, NetworkAnalyst, GeneMania, GEPIA, COSMIC, cBioPortal, STRING, and FunRich were used to investigate the expression of CDC6 gene. Furthermore, survival analysis to correlate the gene expression was carried out using the Kaplan-Meier plotter. Results: The results showed that mRNA levels of CDC6 were significantly higher in TNBC compared to healthy and other types of breast cancer, and high expression levels were also associated with increased TNBC proliferation. The survival analysis showed that increased mRNA levels of CDC6 in all TNBC patients were associated with a poor prognosis for relapse-free survival. Conclusion: The findings of the current study indicate that CDC6 may be used as a possible prognostic biomarker for TNBC. However, further studies are required to check the effects of CDC6 on the progression and pathogenesis of TNBC.

KLF15 suppresses tumor growth and metastasis in Triple-Negative Breast Cancer by downregulating CCL2 and CCL7

Kruppel like factor 15 (KLF15), a transcriptional factor belonging to the Kruppel-like factor (KLF) family of genes, has recently been reported as a tumor suppressor gene in breast cancer. However, the specific mechanisms by which KLF15 inhibits BrCa have not been elucidated. Here we investigated the role and mechanism of KLF15 in triple-negative breast cancer (TNBC). KLF15 expression and methylation were detected by RT-qPCR, RT-PCR and methylation-specific PCR in breast cancer cell lines and tissues. The effects of KLF15 on TNBC cell functions were examined via various cellular function assays. The specific anti-tumor mechanisms of KLF15 were further investigated by RNA sequence, RT-qPCR, Western blotting, luciferase assay, ChIP, and bioinformatics analysis. As the results showed that KLF15 is significantly downregulated in breast cancer cell lines and tissues, which promoter methylation of KLF15 partially contributes to. Exogenous expression of KLF15 induced apoptosis and G2/M phase cell cycle arrest, suppressed cell proliferation, metastasis and in vivo tumorigenesis of TNBC cells. Mechanism studies revealed that KLF15 targeted and downregulated C–C motif chemokine ligand 2 (CCL2) and CCL7. Moreover, transcriptome and metabolome analysis revealed that KLF15 is involved in key anti-tumor regulatory and metabolic pathways in TNBC. In conclusion, KLF15 suppresses cell growth and metastasis in TNBC by downregulating CCL2 and CCL7. KLF15 may be a prognostic biomarker in TNBC.

POR overexpression induces tamoxifen-resistance in breast cancer through the STAT1/c-Myc pathway.

Breast cancer is the most common cancer in women worldwide. Althoughtamoxifen (TAM), a selective estrogen receptor (ER) modulator, is widely used to treat ER-positive breast cancers, resistance to TAM remains a major clinical problem. NADPH-dependent cytochrome P450 reductase (POR) is known to participate in drug metabolism and steroid metabolism. Recent studies showed that high POR expression was correlated with poor outcomes in triple-negative breast cancer (TNBC), and POR might be a prognostic biomarker in TNBC. However, the role of POR in TAM resistance is still elusive. In this study, we found that high POR expression was associated with poor prognosis of ER-positive and TAM-treated breast cancer patients. In addition, COX analysis showed that POR expression was an independent prognostic biomarker for ER-positive as well as TAM-treated breast cancer patients. Furthermore, our results suggested that POR overexpression promoted TAM resistance by activating the STAT1/c-Myc pathway in ER-positive breast cancer cells. Immunohistochemical analysis showed that high POR/STAT1 expression was correlated with poor prognosis in TAM-treated breast cancer patients. Notably, combined treatment with TAM and a specific STAT1 inhibitor Fludarabine was more effective for inhibiting TAM-resistant breast cancer cells. Altogether, our findings suggested that POR overexpression induced TAM resistance through STAT1/c-Myc pathway and might serve as an independent prognostic biomarker in TAM-treated breast cancer patients. Combining TAM and STAT1 inhibitors might be an effective strategy for treating POR-induced TAM-resistant breast cancer.

Reduced miR-371b-5p expression drives tumor progression via CSDE1/RAC1 regulation in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer; however, specific prognostic biomarkers have not yet been developed. In this study, we identified dysregulated microRNAs (miRNAs) in TNBC by profiling miRNA and mRNA expression. In patients with TNBC, miR-371b-5p expression was reduced, and miR-371b-5p overexpression significantly mitigated TNBC cell growth, migration, and invasion. In addition, we found that expression of cold shock domain-containing protein E1 (CSDE1), a direct target gene of miR-371b-5p, was upregulated in TNBC cells, and inhibition of CSDE1 expression alleviated TNBC cell growth by regulating RAC1 transcription. Mechanistically, CSDE1, phosphorylated C-terminal domain (p-CTD) of RNA polymerase II (RNAPII), and CDK7 form a complex, and downregulation of CSDE1 leads to weak interaction between RNAPII p-CTD and CDK7, resulting in a decrease in RNAPII p-CTD expression to reduce RAC1 transcript levels in CSDE1-deficient TNBC cells. Our data demonstrate that miR-371b-5p is a tumor-suppressive miRNA that regulates the CSDE1/Rac1 axis and could be a potential prognostic biomarker for TNBC.

Histamine H4 Receptor Expression in Triple-negative Breast Cancer: An Exploratory Study.

Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype. There are neither universally accepted prognostic markers nor molecular targets related to TNBC. The histamine H4 receptor (H4R) has been characterized in TNBC experimental models, demonstrating its critical role in tumor development and progression. In this study, H4R expression was compared in breast cancer subtypes and correlated with clinical features using The Cancer Genome Atlas data (Pan-Cancer Atlas). The H4R status was further evaluated by immunohistochemistry in 30 TNBC human samples in relation to clinicopathological parameters. Results indicate that H4R was downregulated in basal-like/TNBC compared with luminal A and normal breast-like tumors. The higher expression of H4R was associated with improved progression-free and overall survival outcomes in basal-like/TNBC. H4R immunoreactivity was detected in about 70% of tumors, and its expression was positively correlated with the levels in the histologically normal peritumoral tissue. High H4R expression in peritumoral tissue correlated with reduced number of lymph node involvement and unifocal TNBC, while it was associated with increased patient survival. In conclusion, the H4R might represent a potential prognostic biomarker in TNBC. Further studies in large cohorts are needed to better understand the significance of H4R in breast cancer biology.

Abstract P1-08-24: Platelet-to-lymphocyte ratio is worth using with tumor-infiltrating lymphocytes to predict good response to neoadjuvant chemotherapy in triple negative breast cancer: A study on 120 patients

Abstract Introduction: Triple negative breast cancer (TNBC) is highly heterogeneous, but still most of the patients are treated by the anthracycline/taxane-based neoadjuvant therapy (NACT). Tumor-infiltrating lymphocytes (TILs) are a strong predictive and prognostic biomarker in TNBC, however not always available due to organizational and analytical issues. Peripheral blood counts, which reflect the systemic inflammatory/immune status, are easier to obtain than TILs. We investigated whether baseline white cell or platelet counts, as well as Neutrophil-to-Lymphocyte Ratio (NLR) or Platelet-to-Lymphocyte Ratio (PLR) could replace baseline TILs as predictive or prognostic biomarkers in a series of TNBC treated by standard NACT. Patients and methods: One hundred twenty patients uniformly treated by FEC/taxane NACT in a tertiary cancer care center were retrospectively analyzed. The presence of pathological complete response (pCR: ypT0/Tis, ypN0) or the presence of pCR and small residual disease (ypT0/Tis/T1ab, ypN0) were considered as good responses in data analysis. Baseline/pre-NACT blood count, NLR, PLR and TILs were evaluated as predictors of response, distant recurrence rate and distant recurrence-free survival (DRFS). TILs were assessed on breast tumor biopsies according to the recommendations of the International Immuno-Oncology Biomarker Working Group (www.tilsinbreastcancer.org). Results: TILs ≥30% and ≥1.5% were best predictors of pCR and distant recurrence risk, respectively (p=0.007, p=0.012). However, in this cohort, pCR status was not significantly associated with recurrence. Only the ensemble of patients with pCR and small residual disease had lower recurrence risk and longer survival DRFS (p=0.042, p=0.024, respectively) than the rest of the cohort (larger residual disease). The only parameter which could predict the pCR/small residual disease status was PLR: patients with values lower than 133.25 had significantly higher chance of reaching that status after NACT (p=0.045). However, no direct correlation could be established between baseline PLR and metastatic recurrence. No correlation either was found between TIL and individual blood counts, or between TILs and NLR or PLR. Conclusion: In this cohort, TILs retained their pCR predictive value, however PLR was better predictor of the ensemble of responses which had good outcome in terms of less distant recurrences or longer DRFS (pCR or small residual disease). Thus, baseline PLR is worth further, prospective investigation together with baseline TILs, as it might indicate a good TNBC response to NACT when TILs are unavailable. Citation Format: Nina Radosevic-Robin, Sejdi Lusho, Xavier Durando, Marie-Ange Mouret-Reynier, Myriam Kossai, Nathalie Lacrampe, Ioana Molnar, Frederique Penault-Llorca, Catherine Abrial. Platelet-to-lymphocyte ratio is worth using with tumor-infiltrating lymphocytes to predict good response to neoadjuvant chemotherapy in triple negative breast cancer: A study on 120 patients [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-08-24.

Prognostic Significance of CCNB2 Expression in Triple-Negative Breast Cancer.

PurposeThe aim of this study was to explore potential gene therapy targets for triple-negative breast cancer (TNBC).Patients and MethodsThree gene expression profiles (GSE64790, GSE62931, and GSE38959) from the Gene Expression Omnibus (GEO) database were analyzed. The GEO2R analysis tool was used to screen for differentially expressed genes (DEGs) between TNBC and normal tissues, followed by Gene Ontology functional annotation and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis of the DEGs. The protein–protein interaction network of DEGs was visualized using Metascape to identify the core genes. Subsequently, transcriptional data for the core genes in patients with breast cancer were investigated in the ONCOMINE database. Kaplan–Meier survival analysis was used to evaluate the prognostic value of core gene expression levels in patients with TNBC. Finally, the clinicopathological and long-term follow-up data of 39 patients with TNBC were retrospectively analyzed at the First Affiliated Hospital of the Bengbu Medical College between January 2014 and July 2020. Immunohistochemistry was used to evaluate the expression and subcellular localization of CCNB2 in TNBC tissues.ResultsA total of 66 DEGs were identified between TNBC and normal tissues, including 33 upregulated and 33 downregulated genes in TNBC. Furthermore, a potential protein complex was identified for five core genes. The high expression of these core genes, especially the overexpression of CCNB2, was correlated with a poor prognosis of patients with TNBC. The CCNB2 protein was expressed in the cytoplasm, and its expression was significantly higher in TNBC tissues than that in the adjacent nontumor tissues. Overall survival of patients was significantly correlated with the expression of CCNB2 (p < 0.05).ConclusionCCNB2 may play a crucial role in the development of TNBC and has the potential to be used as a prognostic biomarker for TNBC.

CircRNA circ-PDCD11 promotes triple-negative breast cancer progression via enhancing aerobic glycolysis

Well-described evidence has demonstrated the critical roles of aerobic glycolysis in triple-negative breast cancer (TNBC) oncotherapy. Moreover, next-generation high-throughput sequencing indicates the potential regulation of energy metabolism by circular RNAs (circRNAs) in TNBC. However, circRNA modulation of TNBC aerobic glycolysis is still unclear. Here, the present research aimed to investigate the function and underlying mechanisms of novel circPDCD11 (hsa_circ_0019853) in TNBC aerobic glycolysis. The results revealed that circPDCD11 expression was significantly upregulated in TNBC tissues and cells. Clinical data demonstrated that the high expression of circPDCD11 was closely correlated with a poor prognosis and acted as an independent risk factor for TNBC prognosis. Functionally, in vitro gain- and loss-of-function experiments revealed that circPDCD11 accelerated glucose uptake, lactate production, ATP generation, and the extracellular acidification rate in TNBC cells. In vivo, circPDCD11 silencing repressed tumor growth. Mechanistically, circPDCD11 acted as a miRNA sponge to enhance LDHA expression by sponging miR-432-5p. In conclusion, these combined results demonstrated that circPDCD11 acts as an oncogene for TNBC, providing a promising prognostic biomarker for TNBC.

Upregulation of serum exosomal SUMO1P3 predicts unfavorable prognosis in triple negative breast cancer.

Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer (BC) with poor prognosis. Identification of reliable biomarkers for predicting prognosis of TNBC contributes significantly to improve the clinical outcome and disease management. Long non-coding RNAs (LncRNAs) have been demonstrated to play a critical role in tumorigenesis of TNBC. In this study, we aimed to investigate the prognostic significance of serum exosomal lncRNA small ubiquitin-like modifier 1 pseudogene 3 (SUMO1P3) in TNBC. The expression level and clinical significance of tissue lncRNA SUMO1P3 in BC were analyzed using the public The Cancer Genome Atlas (TCGA) dataset. Then,A. Na-er, Y.-Y. Xu, Y.-H. Liu, Y.-J. Gan the serum exosomal lncRNA SUMO1P3 levels were examined in patients with TNBC, patients with non-TNBC, patients with benign breast disease and healthy controls using the quantitative real-time PCR. The potential clinical significance of serum exosomal lncRNA SUMO1P3 was further evaluated. Based on the TCGA data, tissue lncRNA SUMO1P3 was upregulated in BC tissues, and its upregulation was significantly correlated with poor survival. Our findings showed that the expression level of serum exosomal lncRNA SUMO1P3 was significantly higher in patients with TNBC compared to patients with non-TNBC, patients with benign breast disease and healthy controls. In addition, serum exosomal lncRNA SUMO1P3 was closely correlated with lymphovascular invasion, lymph node metastasis and histological grade. The serum exosomal lncRNA SUMO1P3 levels were markedly decreased in chemosensitive cases, while not in the chemoresistance cases. Moreover, patients in the high serum exosomal lncRNA SUMO1P3 group had worse overall survival than the patients in the low serum exosomal lncRNA SUMO1P3 group. The multivariate analysis showed that serum exosomal lncRNA SUMO1P3 was an independent prognostic factor for TNBC. Collectively, serum exosomal lncRNA SUMO1P3 might be a reliable and robust prognostic biomarker for TNBC.

Association between lincRNA expression and overall survival for patients with triple-negative breast cancer.

Long intergenic non-coding RNAs (lincRNAs) are increasingly recognized as important regulators for pathogenesis and/or prognosis of breast cancer, including triple-negative breast cancer (TNBC) subtype. However, few previous studies used RNA-sequencing (RNA-Seq) technology, and none included an independent replication. To systematically evaluate the association between expression of lincRNAs and TNBC survival, we examined lincRNA expression profiles in TNBC tissues using RNA-Seq data for 200 TNBC patients from the Shanghai Breast Cancer Survival Study (SBCSS) and Southern Community Cohort Study (SCCS). Twenty-five lincRNAs were found to be associated with overall survival (P < 0.05 and no significant heterogeneity across studies at Q statistic P > 0.1), and 61 lincRNAs were associated with disease-free survival (DFS). Among these, two lincRNAs (LINC01270 and LINC00449) were significantly associated with both worse overall survival and DFS and were expressed at significantly higher levels in tumor tissues compared with adjacent normal breast tissues (log2[Fold Change] > 0.5 and FDR < 0.05). We further evaluated the potential functions of LINC01270 and LINC00449 using in vitro functional experiments and found that siRNA-mediated knockdown of LINC01270 and LINC00449 expression significantly decreased cell viability, colony formation and cell migration ability in TNBC cells (P < 0.05). Evidence from observational studies and in vitro experiments indicates that LINC00449 and LINC01270 may be prognostic biomarkers for TNBC.

CircGNB1 Facilitates Triple-Negative Breast Cancer Progression by Regulating miR-141-5p-IGF1R Axis.

As an intriguing class of RNA, circular RNAs (circRNAs) are vital mediators of various diseases including cancers. However, the biological role and underlying mechanism of the majority of circRNAs are still ambiguous in the progression of triple-negative breast cancer (TNBC). In this study, we characterized and further investigated hsa_circ_0009362 (circGNB1) by reanalyzing the circRNA microarray profiling in our previous study. Validating by qRT-PCR, circGNB1 was overexpressed in TNBC cell lines and high expression of circGNB1 was associated with worse clinical features and survival outcomes. The expression of circGNB1 was positively correlated with tumor size and clinical stage, and high expression of circGNB1 was an independent risk factor for TNBC patients. Cell proliferation, colony formation, wound-healing and mouse xenograft assays were carried out to investigate the functions of circGNB1. Both in vitro and in vivo assays revealed that knockdown of circGNB1 significantly suppressed cell proliferation, migration and tumor growth. Subsequently, we performed luciferase reporter assays and RNA immunoprecipitation assays to elucidate the underlying molecular mechanism of circGNB1. The results showed that circGNB1 sponges miR-141-5p and facilitates TNBC progression by upregulating IGF1R. Altogether, our study demonstrated the pivotal role of circGNB1-miR-141-5p-IGF1R axis in TNBC growth and metastasis though the mechanism of competing endogenous RNAs. Therefore, circGNB1 may have the potential to be a therapeutic target and novel prognostic biomarker for TNBC.

Identification of candidate RNA signatures in triple-negative breast cancer by the construction of a competing endogenous RNA network with integrative analyses of Gene Expression Omnibus and The Cancer Genome Atlas data.

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that is characterized by aggressive and metastatic clinical characteristics and generally leads to earlier distant recurrence and poorer prognosis than other molecular subtypes. Accumulating evidence has demonstrated that long non-coding RNAs (lncRNAs) serve a crucial role in a wide variety of biological processes by interacting with microRNAs (miRNAs) as competing endogenous RNAs (ceRNAs) and, thus, affect the expression of target genes in multiple types of cancer. Seven datasets from the Gene Expression Omnibus (GEO) database, including 444 tumor and 88 healthy tissue samples, were utilized to investigate the underlying mechanisms of TNBC and identify prognostic biomarkers. Differentially expressed genes (DEGs) were further validated in The Cancer Genome Atlas database and the associations between their expression levels and clinical information were analyzed to identify prognostic values. A potential lncRNA-miRNA-mRNA ceRNA network was also constructed. Finally, 69 mRNAs from the integrated Gene Expression Omnibus datasets were identified as DEGs using the robust rank aggregation method with |log2FC|>1 and adjusted P<0.01 set as the significance cut-off levels. In addition, 29 lncRNAs, 21 miRNAs and 27 mRNAs were included in the construction of the ceRNA network. The present study elucidated the mechanisms underlying the progression of TNBC and identified novel prognostic biomarkers for TNBC.

Large miRNA survival analysis reveals a prognostic four-biomarker signature for triple negative breast cancer.

Triple negative breast cancer (TNBC) is currently the only major breast tumor subtype without effective targeted therapy and, as a consequence, usually presents a poor outcome. Due to its more aggressive phenotype, there is an urgent clinical need to identify novel biomarkers that discriminate individuals with poor prognosis. We hypothesize that miRNAs can be used to this end because they are involved in the initiation and progression of tumors by altering the expression of their target genes. To identify a prognostic biomarker in TNBC, we analyzed the miRNA expression of a cohort composed of 185 patients diagnosed with TNBC using penalized Cox regression models. We identified a four-biomarker signature based on miR-221, miR-1305, miR-4708, and RMDN2 expression levels that allowed for the subdivision of TNBC into high- or low-risk groups (Hazard Ratio – HR = 0.32; 95% Confidence Interval - CI = 0.11–0.91; p = 0.03) and are also statistically associated with survival outcome in subgroups of postmenopausal status (HR = 0.19; 95% CI = 0.04–0.90; p= 0.016), node negative status (HR = 0.12; 95% CI = 0.01–1.04; p = 0.026), and tumors larger than 2cm (HR = 0.21; 95% CI = 0.05–0.81; p = 0.021). This four-biomarker signature was significantly associated with TNBC as an independent prognostic factor for survival.

MicroRNA-138 is a Prognostic Biomarker for Triple-Negative Breast Cancer and Promotes Tumorigenesis via TUSC2 repression

Breast cancer manifests as a spectrum of subtypes with distinct molecular signatures, and different responses to treatment. Of these subtypes, triple-negative breast cancer (TNBC) has the worst prognoses and limited therapeutic options. Here we report aberrant expression of microRNA-138 (miR-138) in TNBC. Increased miR-138 expression is highly specific to this subtype, correlates with poor prognosis in patients, and is functionally relevant to cancer progression. Our findings establish miR-138 as a specific diagnostic and prognostic biomarker for TNBC. OncomiR-138 is pro-survival; sequence-specific miR-138 inhibition blocks proliferation, promotes apoptosis and inhibits tumour growth in-vivo. miR-138 directly targets a suite of pro-apoptotic and tumour suppressive genes, including tumour suppressor candidate 2 (TUSC2). miR-138 silences TUSC2 by binding to a unique 5′-UTR target-site, which overlaps with the translation start-site of the transcript. Over-expression of TUSC2 mimics the phenotype of miR-138 knockdown and functional rescue experiments confirm that TUSC2 is a direct downstream target of miR-138. Our report of miR-138 as an oncogenic driver in TNBC, positions it as a viable target for oligonucleotide therapeutics and we envision the potential value of using antimiR-138 as an adjuvant therapy to alleviate this therapeutically intractable cancer.