Objective: To analyze the expression of micro-RNA 143 (miRNA-143) in the patients with pancreatic cancer and to explore the influence of overexpression of miRNA-143 on pancreatic cancer cells.Methods: Twenty-five patients with pancreatic cancer that received treatment in their hospital were included in this study. Pancreatic cancer tissues of the patients were surgically removed, and cancer-adjacent tissues were taken for control. Semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the expressions of miRNA-143 and its target gene Kirsten rat sarcoma (KRAS) in pancreatic cancer tissues and cancer-adjacent tissues. Western blot test was conducted to detect the expression of KRAS in pancreatic cancer tissues. Clinicopathologic data of patients were recorded in detail, and the analysis on the correlation of these data with the expression of miRNA-143 in pancreatic cancer tissues was conducted. Pancreatic cancer cell line (PANC-1) was transfected with plasmid for overexpression of miRNA-143, and the influences of miRNA-143 on the apoptosis, migration ability, and invasion ability of the cells were verified by flow cytometry, cell scratch experiment, and Transwell experiment.Results: The results of semiquantitative RT-PCR showed that there were significantly lower expression of miRNA-143 (p < 0.01) and remarkably higher expressions of KRAS gene and KRAS protein (p < 0.01) in pancreatic cancer tissues compared with cancer-adjacent tissues. The expression of miRNA-143 had no correlation with the patient's age and gender, but was closely related to the tumor size, clinical staging, and metastasis of lymph nodes. The detection with flow cytometry showed that cell apoptosis was significantly increased by overexpression of miRNA-143 in PANC-1 (p < 0.01). The result of cell scratch experiment indicated that the migration ability of PANC-1 was reduced significantly by overexpression of miRNA-143 (p < 0.01) and that of Transwell experiment manifested that the invasion ability of PANC-1 was decreased significantly by overexpression of miRNA-143 (p < 0.01).Conclusion: The expression of miRNA-143 in pancreatic cancer tissues is significantly decreased. MiRNA-143 can promote cell apoptosis and regulate the process of pancreatic cancer by inhibiting the migration and invasion of pancreatic cancer cells. [ABSTRACT FROM AUTHOR]