Circ0043898 acts as a tumor inhibitor and performs regulatory effect on the inhibition of esophageal carcinoma

Objective: The study aimed to investigate candidate circular RNAs (circRNAs) in regulating the pathogenic process of esophageal carcinoma. Methods: Specimens were collected from the patients with esophageal carcinoma. Total RNA was purified and treated with RNase R followed by RNA-seq in the purpose of screening the circRNAs in significant differentially expression. The expression level of the screened circRNAs were further validated using RT-PCR. The circular structure of the circRNA was validated with divergent and convergent primers. Overexpression vector was prepared in the purpose of raising the expression level of circ0043898 in the ECA-109 and Kyse-520 cells. The cell colony assay and MTS assay were conducted to determine the capacity of cell proliferation. Chamber assays were applied to determine the capacity of cell migration and invasion while flowcytometry was applied to determine the cell cycle and cell apoptosis. In vivo animal assay was conducted by injecting the cells to the chest of the mice. RNA-seq was performed followed by GO and KEGG study to further verify the regulation mechanism of circ0043898. Results: circ0043898 was validated that down-regulated expressed in the specimens from the patients with esophageal carcinoma. The cell assays proved that overexpression of circ0043898 can obviously inhibit the cell proliferation, cell migration and invasion and induce cell apoptosis and death in the cancerous cells. The in vivo animal study also suggested that the circ0043898 performed inhibitory functions on oncogenesis. The RNA-seq presented the potential regulation mechanism of circ0043898. Histone H3 and BMI1 were presented significantly differential expression in both ECA-109 and Kyse-520 cells, indicating they might be the targets of circ0043898. Conclusion: circ0043898 is presented as tumor inhibitor and could be a candidate biomarker in the therapeutic target and diagnosis of esophageal carcinoma.