Objective To study the expression of human Runt-related transcription factor 1 (RUNX1) in rat airway epithelial cells stimulated by cigarette smoking extract (CSE), and explore the role of RUNX1 in regulating epithelial-mesenchymal transition (EMT). Methods Primary rat bronchial epithelial cells were cultured by enzyme digestion and stimulated with different concentrations of CSE. The viability of cells was detected by CCK-8 to explore the appropriate concentration of CSE. After the cells were treated with CSE, the Runx1 interference and overexpression vectors were constructed and transfected into the cells to silence or overexpress the Runx1 gene. Immunocytochemical method was used to detect RUNX1 expression and Western blot analysis was used to detect the expression of RUNX1, nuclear factor-κB (NF-κB), Snail, E-cadherin, and vimentin. Results The survival rate of bronchial epithelial cells could be reduced by CSE, and the degree of reduction was directly positively correlated to the concentration of CSE. After CSE stimulation, the expression level of E-cadherin in primary rat bronchial epithelial cells decreased significantly (P<0.05); the expression levels of RUNX1, NF-κB, Snail and vimentin significantly increased (P<0.05). After interfering with RUNX1 gene, the expression level of E-cadherin was up-regulated (P<0.05), and the expression levels of NF-κB, Snail and vimentin were down-regulated (P<0.05). After overexpression of RUNX1 gene, the expression level of E-cadherin decreased (P<0.05), and the expression levels of NF-κB, Snail and vimentin increased (P<0.05). Conclusions CSE promotes the expression of RUNX1 in rat airway epithelial cells. RUNX1 might regulate EMT process by involving in the regulation of NF-κB /Snail expression.
ObjectiveTo investigate the expression of Runt-related transcription factor 1 (RUNX1) in gastric cancer and its correlation with clinicopathological features, prognosis and tumor cell invasion ability. Methods① Database analysis: the expression of RUNX1 in gastric cancer and adjacent tissues were analyzed by TCGA and GEO database. Kaplan-Meier Plotter database was used to analyze the correlation between RUNX1 expression level and overall survival (OS) of gastric cancer patients. GO analysis and KEGG pathway enrichment were used to analyze the possible functions and signaling pathways of RUNX1 in gastric cancer, and gene correlation was verified by GEPIA database. ② Clinical case validation: the cancer tissues and adjacent tissues of 62 patients with gastric cancer admitted to the Second Hospital of Lanzhou University from June 2018 to December 2019 were retrospectively collected for immunohistochemical staining, HE staining and Sirius red staining, and the relation between RUNX1 expression and clinicopathological features and prognosis of patients was explored. ③ Cell experiment: we knocked down RUNX1 by using small interfering RNA, and then analyzed the relation between RUNX1 and the invasion ability of gastric cancer cells by Transwell assay. Results① Database analysis: RUNX1 was highly expressed in gastric cancer tissues and negatively correlated with OS (P<0.001). GO analysis and KEGG pathway enrichment analysis showed that RUNX1 was not only involved in the construction of collagen in extracellular matrix (ECM), but also significantly enriched in ECM-receptor interaction pathway. The results of GEPIA gene correlation analysis showed that RUNX1 was positively correlated with gene expression involved in ECM-receptor interaction pathway (P<0.05). ② Clinical case validation: the results of immunohistochemical staining showed that RUNX1 was relatively highly expressed in gastric cancer tissues, and the high expression of RUNX1 was a risk factor affecting the postoperative OS of gastric cancer patients (RR=5.074, P=0.034); the expression of RUNX1 in gastric cancer tissues was positively correlated with red staining area of Sirius red staining (r=0.46, P<0.001). ③ Cell experiment: invasion experiments confirmed that the number of invasive AGS or HGC27 cells in si-001 group and si-002 group decreased after RUNX1 knockdown. ConclusionRUNX1 is highly expressed in gastric cancer and suggests a worse survival prognosis, and it is possible that RUNX1 promotes the development of gastric cancer by activating the ECM-receptor interaction pathway.