Expression Profiles of Novel Breast Cancer- Associated lncRNAs in Relation to Tumor Characteristics and Reproductive Factors

Abstract

Background: Previous studies revealed important functions of three lncRNAs FAL1, HAND2-AS1, and PTCSC3 in development of various cancers; however, their roles in breast cancer is currently unknown. Materials and methods: In the present study, expression levels of LncRNAs were detected by qPCR in 50 breast- tumor and tumor adjacent normal tissues (TANTs). Results: In this study, we found that lncRNA FAL1 was upregulated, while lncRNAs HAND2-AS1 and PTCSC3 were downregulated in tumor tissues than in TANTs (P values ˂ 0.001). Moreover, the results of the current study revealed higher expression of FAL1 in tumors with larger sizes (P = 0.003), higher nuclear grades (P ˂ 0.001), as well as negative statuses of estrogen receptor (ER), progesterone receptor (PR), and HER2 (P ˂ 0.001, P = 0.001 and P ˂ 0.001 respectively). Regarding to HAND2-AS1, our results showed upregulation of this lncRNA in smaller tumor sizes and lower nuclear grades (P values ˂ 0.001). Furthermore, we observed higher levels of PTCSC3 in tumors with HER2- status (P = 0.012), free- lymph node metastasis (LNM) and early stages of BC (P values ˂ 0.001). Finally, our results showed significant differences in expression levels of these lncRNAs between subgroups of some reproductive characteristics including breastfeeding duration, parity, and menopause status. Conclusion: Therefore, lncRNA FAL1 may has oncogenic role in BC and its expression levels correlate with worst outcomes of disease. Inversely, lncRNAs HAND2-AS1 and PTCSC3 may have anti- tumorigenic roles in breast cancer.