Aim: The present study explored the clinical significance of microRNA-22 (miR-22) expression in lung squamous cell carcinoma and to explore the targeting relationship with vascular endothelial growth factor receptor 3 (VEGFR3).
Methods: A total of 49 patients with lung squamous cell carcinoma who underwent surgical treatment was selected. The expression of miR-22 was detected by fluorescence quantitative real-time PCR (qPCR), the expression of VEGFR3 was detected by Western blotting assays, and D240 labeled microlymphatic vessels density (MLVD) was detected immunohistochemistry (IHC). Lung squamous cell carcinoma cell line SK-MES-1 was selected and the targeting relationship between
miR-22 and VEGFR3 was analyzed by double luciferase reporter gene assay. Western blotting assays were used to detect
the expression of vascular endothelial growth factor-D (VEGF-D) and D240 in the blank control group, empty vector transfection group, miR-22 transfection group, miR-22 and VEGFR3 co-transfection group.
Results: The expression range of miR-22 in lung squamous cell carcinoma was 0.8-3.5. The expression of miR-22 in lung
squamous cell carcinoma was significantly different by tumor maximum diameter, lymph node metastasis, vascular invasion
and TNM stage. The expression of miR-22 was linked to survival time. There was a negative correlation between miR-22
and VEGFR3, miR-22 and MLVD. Double luciferase reporter gene assays showed that miR-22 reduced the luciferase activity of pGL3-VEGFR3-WT transfected cells. Compared with the control group, the expression of VEGF-D and D2-40 in the
miR-22 transfection group was significantly decreased. However, VEGF-D and D240 in the miR-22 and VEGFR3 cotransfection group reversed the changes.
Conclusion: We assumed that the abnormal expression of miR-22 in lung squamous cell carcinoma may be involved in the
development and progression of lung squamous cell carcinoma. MiR-22 negatively regulated the target gene VEGFR3 to
mediate lymphangiogenesis. The expression of miR-22 may also be linked to the prognosis of the disease.