AIM: To investigate the effects of p57kip2, cyclinE protein and proliferating cell nuclear antigen (PCNA) on occurrence and progression of human pancreatic cancer. METHODS: The expression of p57kip2, cyclinE protein and PCNA in tumor tissues and adjacent tissues from 32 patients with pancreatic cancer was detected by SP immunohistochemical technique. RESULTS: The positive expression rate of p57kip2 protein in tumor tissues was 46.9%, which was lower than that in adjacent pancreatic tissues (x2 = 5.317, P<0.05). p57kip2 protein positive expression remarkably correlated with tumor cell differentiation (P<0.05), but not with lymph node metastasis (P>0.05). The positive expression rate of cyclinE protein in tumor tissues was 68.8%, which was higher than that in adjacent pancreatic tissues (x2 = 4.063, P<0.05). CyclinE protein positive expression significantly correlated with tumor cell differentiation and lymph node metastasis (P<0.05). The positive expression rate of PCNA in the tumor tissues was 71.9%, which was higher than that in adjacent pancreatic tissues (x2 = 5.189, P<0.05). PCNA positive expression remarkably correlated with tumor cell differentiation and lymph node metastasis (P<0.05). CONCLUSION: The decreased expression of p57kip2 and/or overexpression of cyclinE protein and PCNA may contribute to the occurrence and progression of pancreatic cancer. p57kip2, cyclinE protein, and PCNA play an important role in occurrence and progression of pancreatic cancer. AIM: To investigate the effects of p57kip2, cyclinE protein and proliferating cell nuclear antigen (PCNA) on occurrence and progression of human pancreatic cancer. METHODS: The expression of p57kip2, cyclinE protein and PCNA in tumor tissues and adjacent tissues from 32 patients with pancreatic cancer was detected by SP immunohistochemical technique. RESULTS: The positive expression rate of p57kip2 protein in tumor tissues was 46.9%, which was lower than that in the adjacent pancreatic tissues (x2 = 5.317, P <0.05) The positive expression rate of cyclinE protein in tumor tissues was 68.8%, which was higher than that in the adjacent pancreatic tissues (x2 = 4.063, P <0.05). The positive expression rate of PCNA in the tumor tis (P <0.05) The positive expression of PCNA was significantly correlated with tumor cell differentiation and lymph node metastasis (P <0.05). CONCLUSION: The decreased expression of p57kip2 and / or overexpression of cyclinE protein and PCNA may contribute to the occurrence and progression of pancreatic cancer. p57kip2, cyclinE protein, and PCNA play an important role in occurrence and progression of pancreatic cancer.