LncRNA AY343892 inhibits breast cancer development by positively regulating BRCA1-mediated transcription of PTEN

LncRNA RP11-551L14.4 suppresses breast cancer development by inhibiting the expression of miR-4472

Background

Previous studies have been reported that long non-coding RNA (lncRNA) can regulate the expression of genes which are involved in many important cellular processes The potential role of lncRNA RP11-551L14.4 in the development of breast cancer and the possible regulatory mechanisms was investigated.

Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to analyze RP11-551L14.4 expression in 36 paired breast cancer tissues and adjacent tissues. The expression of RP11-551L14.4 in multiple breast cancer cell lines was detected by qRT-PCR. Meanwhile, overexpression of RP11-551L14.4 models was established using lentivirus in BT474 and T47D breast cancer cells. Cell counting kit-8 (CCK-8), cell colony formation and cell cycle assays were performed to detect the effects of RP11-551L14.4 on the biological function of breast cancer cells. Besides, bioinformatics techniques, dual luciferase reporter gene assay and rescue experiments were used to investigate the potential mechanisms.

Results

RP11-551L14.4 expression was negatively associated with the advanced tumor stage. Breast cancer patients with low RP11-551L14.4 expression manifested a poorer prognosis. The results of qRT-PCR showed that RP11-551L14.4 expression in breast cancer tissues was significantly lower than in adjacent tissues. Meanwhile, overexpression of RP11-551L14.4 significantly decreased the cell proliferation and cell cycle. Bioinformatics technology showed that RP11-551L14.4 could complementarily bind to miR-4472. qRT-PCR results indicated that the expression levels of miR-4472 and RP11-551L14.4 in breast cancer were negatively correlated. Luciferase reporter gene assay showed that miR-4472 remarkably decreased the relative luciferase activity of the wild-type RP11-551L14.4 vector. miR-4472 is a direct target gene of RP11-551L14.4. miR-4472 levels were reduced, and repulsive guidance molecule A (RGMA) mRNA or protein levels were increased after overexpression of RP11-551L14.4 in the breast cancer cells. miR-4472 reversed the effects caused by RP11-551L14.4 in breast cancer cells.

Conclusion

RP11-551L14.4 expression was remarkably decreased in breast cancer tissues and cells. RP11-551L14.4 may inhibit the malignant progression of breast cancer by regulating miR-4472 expression.

Long noncoding RNA ZBED3-AS1 restrains breast cancer progression by targeting the microRNA-513a-5p/KLF6 axis

Breast cancer (BC) is the most commonly occurring malignancy in women. This study aimed to investigate the functions of the long noncoding RNA ZBED3‐AS1 (ZBED3‐AS1) in BC and its molecular mechanisms. qRT‐PCR was conducted to access the expression of ZBED3‐AS1, microRNA‐513a‐5p (miR‐513a‐5p), and Kruppel like factor 6 (KLF6) in BC. Additionally, BC cell viability and proliferative capacity were measured by MTT and 5‐Ethynyl‐20‐deoxyuridine (EdU) assays. A transwell assay was used for evaluating BC cell migration and invasion. The interactions among ZBED3‐AS1, miR‐513a‐5p, and KLF6 in BC were confirmed by dual‐luciferase reporter assay. Furthermore, feedback approaches were performed to determine whether ZBED3‐AS1 influences BC cell behaviors by regulating the miR‐513a‐5p/KLF6 axis. The murine xenograft model was established to assess the effect of ZBED3‐AS1 on tumor growth. The expression of ZBED3‐AS1 and KLF6 was reduced, while miR‐513a‐5p expression was elevated in BC. ZBED3‐AS1 elevation attenuated the malignant behaviors of BC cells, including viability, proliferative capacity, migration, and invasion. Mechanical experiments revealed that ZBED3‐AS1 targeted miR‐513a‐5p, and miR‐513a‐5p targeted KLF6 in BC. Feedback approaches validated that miR‐513a‐5p overexpression or KLF6 depletion reversed the inhibitory effects of ZBED3‐AS1 upregulation on viability, proliferative capacity, migration, and invasion of BC cells. Furthermore, ZBED3‐AS1 elevation attenuated the tumor growth in the murine xenograft model. ZBED3‐AS1 hindered the malignant development of BC cells by regulating the miR‐513a‐5p/KLF6 axis, providing a novel therapeutic target in BC.