Novel Prognostic Marker For Breast Cancer Research Articles

Long Non-Coding RNA NEAT1 Promotes the Proliferation, Migration, and Metastasis of Human Breast-Cancer Cells by Inhibiting miR-146b-5p Expression.

BackgroundBreast cancer (BC) is the most commonly diagnosed cancer in women. Tumor recurrence and metastasis are the key causes of death in BC patients. Long non-coding RNA (lncRNA) is closely associated with BC progression. lncRNA nuclear-enriched abundant transcript (NEAT)1 has been reported to regulate the proliferation and mobility of several types of cancer cells. However, how lncRNA NEAT1 affects the proliferation and invasion of BC cells is not known.MethodsQuantitative real time-polymerase chain reaction (qRT-PCR) was used to measure expression of lncRNA NEAT1 and microRNA (miR)-146b-5p in BC tissues and cell lines. Cell Counting Kit (CCK)-8, cell colony-formation, wound-healing, and Transwell™ assays were undertaken to determine the effects of lncRNA NEAT1 and miR-146b-5p on progression of BC cells. The interaction between lncRNA NEAT1 and miR-146b-5p was examined by luciferase reporter, RNA-binding protein immunoprecipitation (RIP), and RNA-pulldown assays.ResultsExpression of lncRNA NEAT1 was upregulated in BC tissues and cell lines. High expression of lncRNA NEAT1 predicted poor overall survival in BC patients. Silencing of expression of lncRNA NEAT1 inhibited epithelial–mesenchymal transition (EMT) and suppressed the proliferation, migration and invasion of BC cells. Ectopic expression of lncRNA NEAT1 induced EMT and promoted BC progression. Mechanistic investigations revealed that miR-146b-5p was a direct target of lncRNA NEAT1, and its expression was correlated negatively with expression of lncRNA NEAT1 in BC tissues.ConclusionlncRNA NEAT1 could (i) serve as a novel prognostic marker for BC and (ii) be a potential therapeutic target for BC.

Profiling of Small Nucleolar RNAs by Next Generation Sequencing: Potential New Players for Breast Cancer Prognosis.

One of the most abundant, yet least explored, classes of RNA is the small nucleolar RNAs (snoRNAs), which are well known for their involvement in post-transcriptional modifications of other RNAs. Although snoRNAs were only considered to perform housekeeping functions for a long time, recent studies have highlighted their importance as regulators of gene expression and as diagnostic/prognostic markers. However, the prognostic potential of these RNAs has not been interrogated for breast cancer (BC). The objective of the current study was to identify snoRNAs as prognostic markers for BC. Small RNA sequencing (Illumina Genome Analyzer IIx) was performed for 104 BC cases and 11 normal breast tissues. Partek Genomics Suite was used for analyzing the sequencing files. Two independent and proven approaches were used to identify prognostic markers: case-control (CC) and case-only (CO). For both approaches, snoRNAs significant in the permutation test, following univariate Cox proportional hazards regression model were used for constructing risk scores. Risk scores were subsequently adjusted for potential confounders in a multivariate Cox model. For both approaches, thirteen snoRNAs were associated with overall survival and/or recurrence free survival. Patients belonging to the high-risk group were associated with poor outcomes, and the risk score was significant after adjusting for confounders. Validation of representative snoRNAs (SNORD46 and SNORD89) using qRT-PCR confirmed the observations from sequencing experiments. We also observed 64 snoRNAs harboring piwi-interacting RNAs and/or microRNAs that were predicted to target genes (mRNAs) involved in tumorigenesis. Our results demonstrate the potential of snoRNAs to serve (i) as novel prognostic markers for BC and (ii) as indirect regulators of gene expression.

Genome-wide profiling of transfer RNAs and their role as novel prognostic markers for breast cancer.

Transfer RNAs (tRNAs, key molecules in protein synthesis) have not been investigated as potential prognostic markers in breast cancer (BC), despite early findings of their dysregulation and diagnostic potential. We aim to comprehensively profile tRNAs from breast tissues and to evaluate their role as prognostic markers (Overall Survival, OS and Recurrence Free Survival, RFS). tRNAs were profiled from 11 normal breast and 104 breast tumor tissues using next generation sequencing. We adopted a Case-control (CC) and Case-Only (CO) association study designs. Risk scores constructed from tRNAs were subjected to univariate and multivariate Cox-proportional hazards regression to investigate their prognostic value. Of the 571 tRNAs profiled, 76 were differentially expressed (DE) and three were significant for OS in the CC approach. We identified an additional 11 tRNAs associated with OS and 14 tRNAs as significant for RFS in the CO approach, indicating that CC alone may not capture all discriminatory tRNAs in prognoses. In both the approaches, the risk scores were significant in the multivariate analysis as independent prognostic factors, and patients belonging to high-risk group were associated with poor prognosis. Our results confirmed global up-regulation of tRNAs in BC and identified tRNAs as potential novel prognostic markers for BC.

Repression of cathepsin E expression increases the risk of mammary carcinogenesis and links to poor prognosis in breast cancer

Despite advances in detection and treatment for breast cancer (BC), recurrence and death rates remain unacceptably high. Therefore, more convenient diagnostic and prognostic methods still required to optimize treatments among the patients. Here, we report the clinical significance of the serum cathepsin E (CatE) activity as a novel prognostic marker for BC. Correlation analysis between the serum levels of CatE expression and clinicopathological parameters revealed that the activity levels, but not the protein levels, were negatively associated with the stages and progression of BC. Univariate and multivariate analyses demonstrated that the serum CatE activity was significantly correlated with favorable prognostic outcomes of the patients. The functional link of CatE expression to BC progression was further corroborated by in vivo and in vitro studies with mice exhibiting different levels of CatE expression. Multiparous CatE (-) (/) (-) mice spontaneously developed mammary tumors concomitant with morphological transformation and altered growth characteristics of the mammary glands. These alterations were associated in part with the induction of epithelial-mesenchymal transition and the activation of β-catenin-dependent pathway in mammary cells. Loss of CatE strongly induced the translocation and accumulation of Wnt5a in the nuclei, thereby leading to the aberrant trafficking, maturation and secretion of Wnt5a and the impaired signaling. The interaction of CatE and Wnt5a was verified by proximity ligation assay and by knockdown or restoration of CatE expression in the mammary cells. Consequently, our data demonstrate that CatE contributes to normal growth and development of mammary glands through proper trafficking and secretion of Wnt5a.

Abstract P2-10-22: Phosphorylation of Steroid Receptor Coactivator 3 (SRC3) at Ser543 is a novel independent prognostic marker in breast cancer

Abstract Introduction: Steroid receptor coactivator 3 (SRC3) acts as a coactivator of nuclear receptors including estrogen receptor-alpha (ER). SRC3 has been implicated in the pathogenesis of breast cancer (BC) as well as in resistance to endocrine therapy. SRC3 is phosphorylated at a number of residues following the stimulation of growth factors or hormones. Tyr24 and Ser543 are both phosphorylated upon estrogen stimulation, while Tyr24 is modulated by JNK and Ser543 by both p38 and JNK. To date, the importance and potential role of phosphorylation at these residues has not been explored in BC. In this study we assessed the protein expression of SRC3, pTyr24 and pSer543 and association with clinico-pathological features and outcome in a well defined breast cancer series. Methods: The expressions of SRC3, pTyr24 and pSer543 were assessed in the Nottingham Tenovus Primary Breast Cancer Series which consists of 1650 cases of primary invasive. SRC3, pTyr24 and pSer543 were correlated with clinico-pathological data as well as outcome. Results: SRC3 expression was significantly associated with unfavourable clinicopathological features including ER -ve (p = 0.02), PR –ve (p = .038), HER2 overexpression (p < 0.0001), Triple negative phenotype (p = 0.001), high proliferation (p < 0.0001), high histological grade (p < 0.001), and lympho-vascular invasion. On contrast, the expression of pSer543 was significantly associated with a luminal phenotype, well differentiation, low proliferation (low mitotic index, low Ki67 and low SPAG5; p < 0.0001), hormonal receptors (ERα+ve/PR+ve/AR+ve), absence of both ER-B1 and ER-B5 (p < 0.01), high expression of ER-α associated proteins (cyclin D1 and Bcl2; p < 0.0001), high expression of c-jun (p < 0.0001), JNK (p < 0.0001), SRC3 (p < 0.0001), T24 (p < 0.001) and active p53 transcriptional pathways that regulate cell cycle progression and apoptosis (MDM2+ve, MDM4+ve and Bax+ve; p < 0.01) and absence of basal like phenotypes (p < 0.01). The absence of pSer543 was significantly associated with loss of expression of the key DNA repair proteins including XRCC1 (p < 0.0001), BRCA1 (p < 0.0001), ATM (p = 0.008) and TOP2A (p < 0.0001) reflecting a higher risk of genomic instability. Moreover, absence of pSer543 was more common in BC with a triple negative phenotype (p < 0.001). With regard to outcome, no association with outcome based on the expression of SRC3 either with or without tamoxifen was observed. However, expression of pSer543 was associated with significantly longer disease free survival (DFS) (p < 0.00001) and breast cancer specific survival (BCSS) (p = 0.0001). Furthermore, absence of pSer543 was associated with both a shorter DFS (p = 0.007) and BCSS (p = 0.01) in ER+ ve high risk BC. pSer534 was confirmed as an independent prognostic factor after adjustment for endocrine therapy and other validated prognostic factors and absent of pSer534 was associated with a two-fold increased risk of recurrence (HR = 1.9, CI 95%= 1.2–3.1). Data on Tyr24 will also be presented. Conclusion: Phosphorylation at Ser543 is associated with a luminal phenotype, positive prognostic factors and sensitivity to tamoxifen. Furthermore, it is an independent prognostic factor. pS543 is a novel prognostic marker in BC and warrants further investigation. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-10-22.