Expression Study and Clinical Correlations of MYC and CCAT2 in Breast Cancer Patients

Abstract

Background:Colon cancer-associated transcript 2 (CCAT2) is a newly recognized lncRNA transcribed from the 8q24 genomic region. It functions as an oncogene in various types of cancers including breast cancer, in which it affects Wnt/β-catenin pathway. Previous studies have shown a putative interaction between this lncRNA and MYC proto-oncogene.Methods:In the current study, we evaluated the expression of CCAT2 in breast cancer tissues with regards to the expression of its target MYC. In addition, we assessed the relationship between CCAT2 and MYC expression levels in tumor tissues and the clinical prognostic characteristics of breast cancer patients.Results:MYC expression levels were significantly up-regulated in tumor tissues compared with adjacent non-cancerous tissues (ANCTs), while such analysis showed no statistically significant difference between these two tissue types in CCAT2 expression. Starkly increased CCAT2 gene expression levels were found in 12/48 (25%) of cancer tissue samples compared with their corresponding ANCTs. Furthermore, significant inverse correlations were found between CCAT2 expression and stage, as well as lymph node involvement. Besides, a significant inverse correlation was found between the relative MYC expression in tumor tissues compared with their corresponding ANCTs and disease stage.Conclusions:These results highlight the significance of MYC and CCAT2 expressions in the early stages of breast cancer development and suggest a potentially significant role for CCAT2 in a subset of breast cancer patients, which could be applied as a potential therapeutic target in these patients.

Long non‑coding RNA CCAT2 promotes prostate cancer cell proliferation and invasion by regulating the Wnt/β‑catenin signaling pathway

“…Wnt/β-catenin signaling can regulate a variety of developmental events, including proliferation and migration (40). In addition, it has been reported that lncRNA CCAT2 affects glioma, breast cancer and other tumors by regulating the Wnt/β-catenin pathway (35)(36)(37). TCF7L2 is an effector of the Wnt/E-catenin signaling pathway (41).…”

“…It has also been reported that by activating the Wnt/β-catenin signaling pathway, lncRNA CCAT2 affects oral squamous cell carcinoma, ovarian cancer and renal cell carcinoma (33), as well as non-small cell lung cancer, breast cancer, esophageal cancer and glioma (15,17,(33)(34)(35)(36)(37). However, to the best of our knowledge, no studies have previously examined the relationship between CCAT2 and the Wnt/β-catenin signaling pathway in PCa, and its potential regulatory mechanism.…”

Long Non-coding RNAs as Regulators of the Mitogen-activated Protein Kinase (MAPK) Pathway in Cancer

“…Subsequently, they affect telomere biology, chromatin dynamics, genome structure organization [7], DNA repair [8] and tissue homeostasis [9]. They also participate in tumorigenesis process via different mechanisms, such as transcription repression [10], induction of epithelial-mesenchymal transition (EMT) [11], inhibition of tumor suppressors expression [12,13], over-expression of certain oncogenes [14,15], regulation of tumor-associated signal ing pathways [16] as well as modulation of tumor microenvironment [17]. Recently, a handful of lncRNAs have been shown to regulate the MAPK pathway through modulation of the expression of different proteins within this pathway.…”

A Combined Bioinformatics and Literature Based Approach for Identification of Long Non-coding RNAs That Modulate Vitamin D Receptor Signaling in Breast Cancer

“…Such effect has been associated with alterations in the expression of certain transcripts including long non-cod ing RNAs (lncRNAs) in a way that these lncRNAs have been suggested as skin cancer biomarkers which are secreted into the blood or urine via exosomes [10]. In general, lncRNAs comprise an important portion of human transcriptome with fundamental roles in virtually every aspect of cell physiology [11]; their aberrant expression has been associated with pathologic conditions such as cancer [12][13][14][15][16][17][18]. More specifically, VDRregulated lncRNAs has been shown to participate in imprinting, tumor suppression and invasion/ metastasis which implies their involvement in the protective effect of VDR signal ing against skin cancer [10].…”