ABSTRACT
Objective:To explore the expression of long non-coding RNA (lncRNA) RP13-349O20.2 in cervical cancer tissues and its impact on the migration, invasion abilities and chemotherapy sensitivity of cervical cancer cells in vitro and the possible mechanisms.Methods:The GEPIA.CANCER website (the data was updated in June 2023) was used to analyze the relationship between the expression level of RP13-349O20.2 and the overall survival of 253 cervical cancer patients. From January 2020 to August 2022, cancer tissues and paracancerous tissues (>2 cm from the tumor edge) from 40 cervical cancer patients in the Affiliated Tengzhou Central People's Hospital of Xuzhou Medical University were retrospectively collected. Human normal cervical epithelial cells H8 and human cervical cancer cell lines HCC94, C33A, Hela, HCC1106 and SiHa were used for cell experiments in vitro. Real-time fluorescence polymerase chain reaction (qRT-PCR) was used to detect the relative expression of RP13-349O20.2 in cervical cancer tissues, paracancerous tissues and each cell line. The C33A cells with the highest relative expression level of RP13-349O20.2 were transfected with small interfering RNA (siRNA) of RP13-349O20.2 and siRNA of its negative control sequence, and they were si-RP13-349O20.2 group and si-Con group, respectively. The scratch healing assay was used to detect the migration ability of C33A cells in the two groups, the Transwell assay was used to detect the invasion ability of C33A cells, and the CCK-8 method was used to detect the sensitivity of C33A cells to 5-fluorouracil. The absorbance value indicated the cell proliferation ability, the lower the absorbance value, the weaker the proliferation ability, the more sensitive to the drug. Dual-luciferase reporter gene assay was used to verify the targeting relationship between RP13-349O20.2 and miRNA-493-5p (miR-493-5p), miR-493-5p and Nectin-4. qRT-PCR was used to detect the relative expression of miR-493-5p and Nectin-4 mRNA in two groups of C33A cells, and Western blotting was used to detect the expressions of Nectin-4 protein and PI3K-AKT signaling pathway proteins in two groups of cells.Results:Analysis based on data from GEPIA.CANCER website shows that patients with low expression of RP13-349O20.2 had better overall survival than patients with high expression ( P < 0.01). The relative expression levels of RP13-349O20.2 in cervical cancer tissues and paracancerous tissues of 40 patients were 4.04±0.32 and 1.18±0.14, and the difference was statistically significant ( t = 8.29, P < 0.01). Compared with H8 cells, the expressions of RP13-349O20.2 in human cervical cancer cell lines HCC94, C33A, Hela, HCC1106 and SiHa were higher (all P < 0.01). The relative expression levels of RP13-349O20.2 in C33A cells in the si-Con group and si-RP13-349O20.2 group were 7.30±0.30 and 1.01±0.27, and the difference was statistically significant ( t = 15.62, P < 0.01). The scratch healing rates of C33A cells in the si-Con group and si-RP13-349O20.2 group were (32±9)% and (75±6)% ( t = 3.97, P < 0.01), and the numbers of invasive cells were (106±12) cells and (36±8) cells ( t = 4.79, P < 0.01). After the action of 5, 10, 20, 40 and 80 μmol/L 5-fluorouracil for 24 h, the absorbance value of C33A cells in the si-RP13-349O20.2 group was lower than that in the si-Con group. Dual-luciferase reporter gene assay confirmed that there was a targeting relationship between P13-349O20.2 and miR-493-5p ( P < 0.01), and there was a targeting relationship between miR-493-5p and Nectin-4 ( P < 0.01) . The relative expression levels of miR-493-5p in C33A cells in the si-Con group and si-RP13-349O20.2 group was 1.02±0.13 and 5.48±0.85 ( t = 5.21, P < 0.01). The relative expression levels of Nectin-4 mRNA were 5.65±0.33 and 0.99±0.34 ( t = 9.87, P < 0.01). The expression of Nectin-4 protein in C33A cells in the si-RP13-349O20.2 group was lower than that in the si-Con group ( t = 9.21, P = 0.001), and the expressions of PI3K-AKT signaling pathway proteins p-STAT3, p-PI3K, p-AKT and p-mTOR were lower than those in the si-Con group (all P < 0.01). Conclusions:The level of RP13-349O20.2 in cervical cancer tissues is high, and its high expression may indicate the poor prognosis of patients. Interfering with the expression of RP13-349O20.2 in vitro can inhibit the migration and invasion abilities of cervical cancer cells and promote the sensitivity of cervical cancer cells to 5-fluorouracil. The mechanism may be related to the miR-493-5p/Nectin-4 signaling pathway and the PI3K-AKT signaling pathway.