[PLK1 Expression in Mantle Cell Lymphoma and Its Clinical Significance].

OBJECTIVE: To explore the expression level of PLK1 in mantle cell lymphoma(MCL), and the effect of silencing PLK1 gene by RNA interference on the cell proliferation, apoptosis, and cell cycle. METHODS: S-P immunohistochemistry technique was used to detect the expression of PLK1 in tissues of 42 patients with MCL and 30 patients with reactive proliferative lymphodenitis(RPL), their expression levels were compared and analyzed. The Jeko-1 cells were transfected with lentivirus contaiming PLK-1 shRNA, then the mRNA and protein expression of PLK-1 was detected by real-time guantitative PCR and Western blot nespectively, and the silencing efficacy of PLK-1 shRNA was identificd. The cell proliferation was detected by CCK method, the cell apoptosis was detected by Annexin V/PI double staining, the cell cycle was detected by PI single staining, the changes of apoptosis-related proteins BAX, BCL-2 and Caspase 3 were detected by Western blot. RESULTS: The positive expression rate of PLK-1 in tissue of MCL patients was 66.67%(28/42), which was significanfly higher than 20%(6/30) in tissue of RPL patients (P＜0.05). The PLK-1 positive expression correlated with B symptom, IPI score, Ann-Arbor stage(P＜0.05). After infection of Jeko-1 cells with lentivirus containing PLK-1 shRNA for 72 hours, the mRNA and protein expressions of PLK-1 were significantly down-regulated(P＜0.05), the proliferation rate of cells in group of PLK-1 shRNA was significanly lower than that in control and Neg shRNA groups(P＜0.05); the apoptosis rate of cells in PLK-1 shRNA group was (27.42±3.44)%, which was significantly higher than that in control group (1.23±0.42)% and Neg shRNA group (2.07±0.58) % (P＜0.05). The cell cycle analysis showed that the cell ratio in G2/M phase of PLK-1 shRNA group was (27.21±3.59) %, which was higher than that in control group (13.28±2.63)% and Neg shRNA group (14.34±2.37) %. The detection of apoptosis-related proteins showed that the expression of BAX was up-regulated, the expression of BCL-2 was down-regnlated and the expression of caspase 3 was up-regulated. CONCLUSION: The PLK-l overexpression appears in tissue of MCL patients. The silencing PLK-1 gene can inhibit the proliferation of Jeko-1 cells, induce the apopotosis of Jeko-1 cells and arrestes cell cycle in G2/M phase.