Objective:To investigate the possible roles of CyclinD1

P16 and PCNA play in the pathogenesis and development of endometriosis.Methods:Twenty-five specimens of eutopic endometrium and Twenty-eight specimens of ectopic endometrium tissues were obtained from 28 patients with endometriosis(observation group).Thirty-five specimens of endometrium were also obtained from women with other benign diseases(control group).CyclinD1

P16 and PCNA was detected by immunohistochemistry.Results:The positive expression of PCNA protein in ectopic endometrium was significantly higher than that in the eutopic endometrium and control group(P<0.05).The positive expression of CyclinD1 protein in ectopic endometrium was significantly higher than that in the eutopic endometrium and control group(P<0.05).The positive expression of P16 in control group was significantly higher than that in the eutopic endometrium and ectopic endometrium(P<0.05).It showed that in the ectopic endometrium the positive expression of CyclinD1 and P16 were negatively spearman correlation(kappa coefficient =-0.521

P<0.01).The positive expression of CyclinD1

P16 and PCNA protein in proliferative phase compared with the secretory phase of the eutopic endometrium

there was no significant difference(P>0.05).Conclusion:The abnormality expression of CyclinD1、P16 and PCNA in the ectopic endometrium may be involved in the proliferation of endometrium in endometriosis.