Objective To investigate the expressions and effects of EGR-1, p53, p16, Cyclin D1 in Nasopharyngeal Carcinoma (NPC). Methods Expressions of EGR-1, p53, p16, and Cyclin D1 protein in paraffin-embedded specimens of 29 chronic nasopharyngitis, 45 NPC and 24 lymph-node metastasis were studied by immunohistochemical method (SABC). Results The positive rates of EGR-1, p16, and Cyclin D1 protein expressions in chronic nasopharyngitis were 44.83 %(13/29), 89.66 %(26/29) and 24.14 %(7/29) respectively, but no p53 protein expression. In NPC, the positive expression rates of the four proteins were 22.22 %(10/45), 91.11 %(41/45), 53.33 %(24/45) and 66.67 %(30/45), with significant difference compared with chronic nasopharyngitis respectively; and in lymph nodes metastasis were 16.67 %(4/24), 79.17 %(19/24), 70.83 %(17/24) and 75.00 %(18/24) with significant difference compared with those of chronic nasopharyngitis and NPC respectively except for p16 protein. Spearman correlation analysis showed that there were no significant correlation between the expression of EGR-1 and p53, p16, Cyclin D1 respectively both in NPC and in lymph nodes metastasis. In NPC, the expression of p53 showed a positive correlation with the expression of p16; and in lymph nodes metastasis the expression of Cyclin D1 showed positive correlation with the expressions of p16 and p53. Conclusions The expression of EGR-1 protein was significantly decreased both in NPC and in lymph-node metastasis, which suggested that Egr-1 gene may be a tumor suppressor gene and have an important effect in the pathogenesis and the progression of NPC. The overexpression of p53 and Cyclin D1 also have an important role in NPC, but p16 probably have no biological significance in NPC.

Objective To investigate the effect of SP600125 on the proliferation, cell cycle, apoptosis and invasion of human cervical cancer HeLa cells. Methods CCK-8 method was used to detect the proliferation of HeLa cells treated with different concentrations of SP600125 at different time points. The 20 μmol/L of SP600125 was determined for subsequent experiments. Cell proliferation ability was detected using plate clone formation assay; nuclear morphology was observed by DAPI staining; cell cycle and apoptosis were measured by flow cytometry; cell migration and invasion were detected by cell scratch and Transwell methods; the mRNA and protein levels of p53, Mad2L1 and CDC20 were measured by qRT-PCR and Western blot after SP600125 treatment at different time points. Results Compared with control group (0.1%DMSO), cells proliferative activity were reduced by 10, 20, 30, 40 and 50 μmol/L SP600125 treatment for 24h. Compared with control group, the rate of apoptosis was significantly increased in SP600125 treatment groups, and the cell proportion in G₂/M phase increased (P < 0.001), while the cell proportion in G₀/G₁ phases cells was reduced after SP600125 treatment for 24h and 48h (P < 0.001), and the clonal number, migration and invasion ability of HeLa cells also decreased significantly (P < 0.001). qRT-PCR and Western blot results showed a significant decrease in Mad2L1 mRNA and protein expression (P < 0.05) and a significant increase in p53 and CDC20 mRNA and protein expression (P < 0.01). Conclusion SP600125 can induce cell cycle arrest of cervical cancer HeLa cells in G₂/M phase by upregulating p53 and CDC20 and downregulating Mad2L1 expression, and promote cell apoptosis to inhibit cell proliferation, migration and invasion.