Circular RNA 0001313 Knockdown Suppresses Non-Small Cell Lung Cancer Cell Proliferation and Invasion via the microRNA-452/HMGB3/ERK/MAPK Axis

Background

Non-small cell lung cancer (NSCLC) seriously endangers human health. Circular RNAs (circRNAs) regulate diverse types of cancers, including NSCLC. This study investigated the possible mechanism of circ0001313 in NSCLC.

Materials and Methods

Circ0001313 expression in NSCLC tissues was measured, and its correlation with clinicopathological features was analyzed. The binding relationships among circ0001313, microRNA (miR)-452 and HMGB3 were tested. The gain and loss of functions were performed to examine NSCLC cell malignant behaviors. After HMGB3 overexpression, ERK/MAPK pathway-related protein levels were detected. Subsequently, the rescue experiment was further performed using an ERK/MAPK pathway inhibitor PD98059.

Results

Abnormally elevated circ0001313 and decreased miR-452 in NSCLC cells were observed. Circ0001313 silencing or miR-452 overexpression significantly reduced NSCLC cell proliferation and invasion. Circ0001313 competitively bound to miR-452 to upregulate HMGB3, thus promoting NSCLC cell growth. HMGB3 overexpression activated the ERK/MAPK pathway to contribute to NSCLC development.

Conclusion

We highlighted that silencing of circ0001313 blunted the ERK/MAPK pathway via the miR-452/HMGB3 axis, thereby inhibiting NSCLC cell proliferation and invasion.

MicroRNA-452 suppresses pancreatic cancer migration and invasion by directly targeting B-cell-specific Moloney murine leukemia virus insertion site 1

Pancreatic cancer, one of the most common cancers globally, is the fourth most common cause of cancer-associated mortality in the USA. The 5-year relative survival rate for patients with pancreatic cancer is ~5% and the median survival time is only 6 months. The poor prognosis is mainly due to early and aggressive local invasion and metastasis, as well as dissemination of the pancreatic cancer cells. The present study demonstrated that microRNA-452 (miR-452) was markedly downregulated in pancreatic cancer tissues, particularly in metastatic tumors and pancreatic cancer cell lines. Overexpression of miR-452 significantly inhibited migration and invasion in pancreatic cancer cells. In addition, the molecular mechanism underlying the inhibitory functions of miR-452 in pancreatic cancer was also investigated. The results indicated that B-cell-specific Moloney murine leukemia virus insertion site 1 (BMI1) was a direct target gene of miR-452 in pancreatic cancer. Overexpression of miR-452 inhibited the migration and invasion of pancreatic cancer, at least partially by knockdown of BMI1 expression. The results provided novel insight with potential therapeutic applications for the treatment of metastatic pancreatic cancer.

Tumor-suppressive microRNA-452 inhibits migration and invasion of breast cancer cells by directly targeting RAB11A

Breast cancer is the most common type of malignant tumor in females, and metastasis is the most common cause of breast cancer-associated mortality. Previous studies have identified that abnormal expression of microRNAs is commonly observed in human cancer and may be crucial for cancer metastasis. In the present study, microRNA-452 (miR-452) was investigated for its ability to act as a tumor suppressor in breast cancer. miR-452 expression was quantified in breast cancer tissue samples and cell lines with reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Transwell migration and invasion assays were used to investigate the effect of miR-452 on the migration and invasion capabilities of breast cancer cells. Potential target genes of miR-452 were identified with miRanda and TargetScan. A luciferase reporter assay was performed to validate RAB11A as a putative target of miR-452, and was corroborated by RT-qPCR and western blot analyses. Finally, small interfering RNA (siRNA) was used to knockdown RAB11A expression and confirm whether miR-452 inhibited breast cancer cell migration and invasion via the negative regulation of RAB11A. The results revealed that miR-452 was downregulated in breast cancer tissues and cell lines, and that its downregulation may be associated with breast cancer metastasis, as miR-452 expression inhibited the migration and invasion capacities of breast cancer cells. RT-qPCR and western blot analyses indicated that miR-452 negatively regulated the expression of RAB11A mRNA and protein. The luciferase reporter assay revealed that miR-452 specifically bound to the 3'-untranslated region of RAB11A. Furthermore, inhibition of RAB11A with siRNA inhibited breast cancer cell migration and invasion. In conclusion, the present study has demonstrated that miR-452 may act as a tumor suppressor gene via inhibition of cell migration and invasion by targeting RAB11A in breast cancer.