miR‑802 inhibits the epithelial‑mesenchymal transition, migration and invasion of cervical cancer by regulating BTF3

Abstract

Microrna (mir)-802 has been discovered to be involved in the occurrence and development of numerous types of tumor; however, studies into the role of mir-802 in cervical cancer are limited. Therefore, the present study aimed to investigate the regulatory effects of mir-802 in cervical cancer cells. mir-802 expression levels in cervical cancer tissue and cells were analyzed using reverse transcription-quantitative (rT-q) Pcr, a dual-reporter luciferase activity assay was used to identify the direct target gene of mir-802, and rT-qPcr and western blotting were performed to determine the relationship between mir-802 and basic transcription factor 3 (BTF3). cell viability, and migration and invasion were analyzed using cell counting Kit-8 and Transwell assays, respectively. Finally, the expression levels of metastasis-associated proteins, n-cadherin and e-cadherin, were determined using rT-qPcr and western blotting. decreased expression levels of mir-802 were found in cervical cancer tissues and cells, and the overexpression of mir-802 inhibited cell viability, migration and invasion. Moreover, mir-802 was discovered to directly target BTF3 to inhibit its expression. notably, the overexpression mir-802 markedly reversed the promotive effect of BTF3 on cell viability, in addition to the migratory and invasive abilities of the cells. Simultaneously, the overexpression of mir-802 significantly suppressed epithelial-mesenchymal transition, and the expression levels of matrix metallopeptidase (MMP)2 and MMP9 in cells through regulating BTF3. in conclusion, the present study revealed that mir-802 may suppress cervical cancer progression by decreasing BTF3 expression levels, indicating that it may represent a potential therapeutic target for the treatment and prognosis of patients with cervical cancer.

Molecular Characterization of the Oncogene BTF3 and Its Targets in Colorectal Cancer

“…A previous study indicated that BTF3 was downregulated by miR-802 in ovarian cancer ( Wu et al, 2020 ). BTF3 expression is significantly increased in CRC, while the role of miRNAs remains obscure.…”

“…Basic transcription factor 3 (BTF3), also known as nascent-polypeptide-associated complex (NAC) beta (NACB), was reported to serve as an oncogene and convey worse prognosis in gastric cancer ( Liu et al, 2013 ; Zhang et al, 2017 ), pancreatic cancer ( Kusumawidjaja et al, 2007 ), osteosarcoma ( Liu et al, 2019a ), cervical cancer ( Wu et al, 2020 ), hypopharyngeal squamous cell carcinoma ( Zhang et al, 2019 ), prostate cancer ( Hu et al, 2019 ), breast cancer ( Ding et al, 2019 ), and CRC ( Liu et al, 2019b ). BTF3 initiates transcription by binding to promoter elements, such as TATA box and CAAT box sequences, in the promoter region ( Cavallini et al, 1988 ; Kanno et al, 1992 ).…”

Dysfunction of miR‐802 in tumors

“…In vitro experiments also further showed that miR-802 promoted the proliferation of lung cancer cells. 35 The abnormal expression of miR-802 has been confirmed in the tumor tissues or tumor cells of 15 cancers, including TSCC, 4 OSCC, 5,6 LSCC, 8 GC, [9][10][11] CRC, [12][13][14] PC, [30][31][32] HCC, [22][23][24][25] PCa, 2,33 bladder urothelial cancer, 26 BC, 15,16 CC, [17][18][19] EOC, 20 lung cancer, [34][35][36] osteosarcoma, 27,28 and melanoma. 21 To note, the abnormal expression of miR-802 in ESCC 7 and cholesteatoma 29 has only been confirmed in tumor cells.…”

“…Subsequent experiments further revealed that miR-802 expression can regulate a series of cell behaviors, including cell proliferatio n, 2,[7][8][9]11,[13][14][15]18,[20][21][22][24][25][26]28,29,31,[33][34][35] invasion, 4,6,[11][12][13][14]17,[19][20][21]33,34,36 metastasis, 2,6,7,[11][12][13][14]17,20,21,25,26,33,34,36 apoptosis, [8][9][10]13,...…”

“…Some studies have also confirmed the tumor suppressor effect of miR‐802 in mouse models. Existing studies have found that the expression of miR‐802 is decreased in at least 10 cancers, including TSCC, 4 OSCC, 5 , 6 ESCC, 7 LSCC, 8 GC, 9 , 10 , 11 CRC, 12 , 13 , 14 BC, 15 , 16 CC, 17 , 18 , 19 EOC, 20 and melanoma. 21 It is worth noting that the direction of abnormal expression of miR‐802 in the other 4 tumors is inconsistent.…”