Zhao Xiqun, Hong Yanqing, Cheng Qingyuan, Guo Lixin
Department of Pediatric Dentistry, Jinan Stomatological Hospital, Jinan, Shandong 250001, People's Republic of China.
Prosthodontic Lab, Jinan Stomatological Hospital, Jinan, Shandong 250001, People's Republic of China.
Onco Targets Ther. 2020 Oct 7;13:9977-9989. doi: 10.2147/OTT.S264410. eCollection 2020.
Tongue squamous cell carcinoma (TSCC) accounts for one-third of oral cancers. Previous studies had reported that lncRNA/miRNA regulated the biological behaviors of different cancer cells. However, the mechanisms of PART1 in regulating tumorigenesis and TSCC development via targeting miR-503-5p had not been studied.
The expressions of PART1 and miR-503-5p in tissues and cultured cell lines were detected by qRT-PCR. StarBase 3.0 was used to predict the binding sites of PART1, then dual-luciferase assay and RNA pull-down assay were executed to confirm whether miR-503-5p was a target of PART1. TSCC cells were co-transfected with PART1-overexpressed plasmid or miR-503-5p mimics in vitro, and the transfection efficiency was evaluated through qRT-PCR. Western blot was performed to assess the expressions of EMT-related proteins. CCK-8 and clone formation assays were conducted to detect cell proliferation, TUNEL assay was used to detect apoptosis, and transwell assay was executed to test migration and invasion.
The low PART1 expression and high miR-503-5p expression were found in TSCC tissues and cell lines (CAL-27 and SCC9). PART1 expression was positively correlated with patients' prognosis. The targeting and binding relationship between PART1 and miR-503-5p was confirmed, and overexpressed PART1 diminished the expression of miR-503-5p as well. Moreover, PART1 facilitated apoptosis, inhibited proliferation, invasion and migration of TSCC cells, and these influences were impeded by miR-503-5p overexpression.
LncRNA PART1 played a cancer-suppressing role in TSCC by targeting miR-503-5p, which provided a potential target for TSCC treatment.
舌鳞状细胞癌（TSCC）占口腔癌的三分之一。先前的研究报道lncRNA/miRNA调节不同癌细胞的生物学行为。然而，PART1通过靶向miR-503-5p调节肿瘤发生和TSCC发展的机制尚未得到研究。
采用qRT-PCR检测组织和培养细胞系中PART1和miR-503-5p的表达。使用StarBase 3.0预测PART1的结合位点，然后进行双荧光素酶测定和RNA下拉测定，以确认miR-503-5p是否为PART1的靶标。在体外将TSCC细胞与PART1过表达质粒或miR-503-5p模拟物共转染，并通过qRT-PCR评估转染效率。进行蛋白质免疫印迹法评估EMT相关蛋白的表达。进行CCK-8和克隆形成试验以检测细胞增殖，使用TUNEL试验检测细胞凋亡，并进行Transwell试验检测迁移和侵袭。
在TSCC组织和细胞系（CAL-27和SCC9）中发现PART1表达低而miR-503-5p表达高。PART1表达与患者预后呈正相关。确认了PART1与miR-503-5p之间的靶向结合关系，过表达PART1也降低了miR-503-5p的表达。此外，PART1促进TSCC细胞凋亡，抑制其增殖、侵袭和迁移，而miR-503-5p过表达则阻碍了这些影响。
lncRNA PART1通过靶向miR-503-5p在TSCC中发挥抑癌作用，为TSCC治疗提供了潜在靶点。
