High expression of importin 13 in endometrium of patients with endometriosis and endometrial cancer

Objective To investigate the expressions and significances of importin 13(IPO13)in normal endometrium as well as the endometrium of patients with endometriosis and endometrial cancer.Methods The endometrium samples at proliferation phase collected from 20 healthy women were served as control group A,while those at secretion phase from healthy women as control group B.However,the endometrium samples collected from 20 patients with endometriosis and 20 patients with endometrial cancer were served as test groups C and D respectively.The expressions of IPO13 in various groups were determined by immunohistochemcial assay,while the co-expression of markers of stem / progenitor cells of IPO13 by IFA,the transcription level of IPO13 mRNA by fluorescent quantitative PCR,and the expression level of IPO13 protein by Western blot.Results IPO13 was expressed in glandular epithelium cells as well as cytoplasm and nuclei of interstitial cells of endometrium in various groups.The positive cell counts for IPO13 in group B was significantly lower than those in groups A,C and D(P 0.01).Co-expressions of IPO13 and CD34,CD45,telomerase,OCT4,C-KIT,PDGF-Rβ,CD90 and CD146 were observed in epithelium and interstitial cells of endometrium in various groups.Both the transcription levels of IPO13 mRNA and expression levels of IPO13 protein in two test groups and control group A were significantly higher than those in control group B(P 0.01).Conclusion IPO13 was expressed in normal endometrium,of which the expression level was higher in the endometrium in proliferation phase than in secretion phase.However,the expression levels of IPO13 in the endometrium of patients with endometriosis and endometrial cancer were significantly higher than that in the normal endometrium in secretion phase,which was speculated to be associated with the abnormal expression of stem / progenitor cells.IPO13 may be served as a candidate marker of stem / progenitor cells of endometrium.