Expression and function of long intergenic non-protein coding RNA-regulator of reprogramming in high-grade ovarian serous cancer

Abstract

Objective: To investigate the expression of long intergenic non-protein coding RNA-regulator of reprogramming (Linc-ROR) in high-grade ovarian serous cancer, and explore the relationship between Linc-ROR expression and biological function of high-grade ovarian serous cancer. Methods: A total of 34 high-grade ovarian serous cancer tissue samples and 19 normal fallopian tube tissue samples were collected between June 2014 and February 2016. Real-time reverse transcription (RT)-PCR was used to detect the Linc-ROR mRNA expression in different samples. The relationship between Linc-ROR expression level and ovarian cancer International Federation of Gynecology and Obstetrics (FIGO) stage, lymph node metastasis was analyzed. Constructed Linc-ROR small interference RNA (siRNA) and pIRES2-EGFP-Linc-ROR plasmid, then Linc-ROR siRNA and pIRES2-EGFP-Linc-ROR plasmid were respectively transfected into SKOV3 cells. Cell proliferation, migration and invasion ability were assessed by cell counting kit-8 (CCK-8), wound healing assay and transwell invasion assay. Results: (1) The expression level of Linc-ROR mRNA was significantly higher in high-grade ovarian serous cancer than normal fallopian tube tissues (4.31± 0.38 vs 1.03 ± 0.21; t=25.842, P<0.01). With the progression of FIGO stages, the expression of Linc-ROR was increased (F=95.702, P<0.01), and it was associated with lymph node metastasis (t=7.397, P<0.01). (2) The results of RT-PCR showed that the expression level of linc-ROR in Linc-ROR-i group was significantly lower than that in Linc-ROR-NC-i group (0.30 ± 0.11 vs 1.02 ± 0.10; t=15.269, P<0.01). The expression level in Linc-ROR-p group was significantly higher than that in Linc-ROR-NC-p group (8.90± 0.45 vs 1.03±0.17; t=21.934, P<0.01). The CCK-8 assay showed that when the cells were cultured for 3, 4, 5 and 6 days, the A value in Linc-ROR-i group was significantly lower than that in Linc-ROR-NC-i group (P< 0.05). And the A value in Linc-ROR-p group was significantly higher than that in Linc-ROR-NC-p group (P< 0.05). Wound healing assay showed that, after 48 hours incubation, migration rate of cells in Linc-ROR-i group was significantly less than that in the Linc-ROR-NC-i group [(52±4)% vs (67±5)%; t=5.720, P< 0.01]. The migration of cells in Linc-ROR-p group was significantly greater than that in the Linc-ROR-NC-p group [(84±4)% vs (66±4)%; t=7.330, P <0.01]. Cell transwell invasion assay showed that, after 48 hours of incubation, the number of invasive cells in Linc-ROR-i group was lower than that in Linc-ROR-NC-i group (74 ± 3 vs 104 ± 3; t=15.810, P<0.01). And the number of invasive cells in Linc-ROR-p group was higher than that in Linc-ROR-NC-p group (217 ± 4 vs 108 ± 5; t=38.060, P<0.01). Conclusion: Highly expressed Linc-ROR could enhance the proliferation, migration and invasion ability of high-grade ovarian serous cancer cells, which may be one of the important molecules in the occurrence and development, invasion and metastasis of high-grade ovarian serous cancer.