Abstract:  Objective:To investigate the effects and mechanism of expression of microRNA100 in the tissues of pancreatic cancer and its relationship with clinicopathological factor.
Methods:The clinical data of 17 patients with pancreatic cancer who were admitted to the Affiliated Hospital of Guizhou Medical University between January 2013 and March 2014 were retrospectively analyzed. The surgical specimens were collected for study. The expression of microRNA100 in the pancreatic tissues were detected by realtime fluorescent quantitative polyme rase chain reaction (RTPCR) and its relationship with clinicopathological factors was analyzed. The MIA PaCa-2 cells and CFPAC1 cells were infected by lvmicroRNA100. MIA PaCa-2 cells were divided into the M 〖HJ〗group (microRNA100 were infected) and N group (empty vectors were infected), and CFPAC1 cells were divided into the C group (microRNA100 were infected) and D group (empty vectors were infected). The expressions of microRNA100 in the CFPAC1 cells and MIA PaCa-2 cells were detected by RTPCR and cell cycles were detected by flow cytometry. The expressions of Cyclin D1 protein in the CFPAC1 cells and MIA PaCa-2 cells were detected by Western blot. Measurement data with normal distribution were presented as ±s and comparison among groups were done by t test.
Results:The results of RTPCR showed that the relative quantitative expression of microRNA100 in the pancreatic cancer tissues was 0.046±0.020, which was significantly different from 0.097±0.017 in the adjacent tissues  (t=2.789, P<0.05). There were significant differences between the tumor differentiation degree and tumor staging in patients with pancreatic cancer (t=2.563, 2.135, P<0.05). The results of RTPCR showed that the relative quantitative expression of microRNA100 in the M group was 0.097±0.012, which was significantly higher than 0.018±0.006 in the N group (t=4.410, P<0.05). The relative quantitative expression of microRNA100 in the C group was 0.084±0.021, which was significantly higher than 0.023±0.010 in the D group (t=5.351, P<0.05). The results of flow cytometry showed that the percentage of cells between G0-G1 were 45.3%±0.7% in the M group and 30.6%±0.7% in the N group，with a significant difference (t=5.564, P<0.05). The percentage of cells between G0-G1 were 58.8%±1.0% in the C group and 42.6%±0.7% in the D group，with a significant difference (t=7.771, P<0.05). The results of Western blot showed that the relative quantitative expression of Cyclin D1 protein were 0.352±0.081 in the M group and 0.872±0.134 in the N group, with a significant difference (t=7.651, P<0.05). The relative quantitative expression of Cyclin D1 protein was 0.410±0.121 in the C group, which was significantly different from 0.979±0.232 in the D group (t=8.712, P<0.05).
Conclusion:Low expression of microRNA100 in pancreatic cancer tissues may be correlated with tumor differentiation degree and tumor staging, it can inhibit tumor cells proliferation by reducing expression of Cyclin D1 protein.