The expression levels of stem cell markers importin13, c-kit, CD146, and telomerase are decreased in endometrial polyps

Abstract

Background: To investigate the expression levels of importin13 (IPO13), c-kit, CD146, telomerase, caspase-3, bcl-2 and bax in endometrial polyps (EPs).

Material/methods: We detected the mRNA expression levels of IPO13, c-kit, bcl-2 and bax in endometrial polyps (EPs) using real-time PCR. We detected the protein expression levels of IPO13, telomerase, CD146, caspase-3, bcl-2 and bax in EPs using S-P (Streptavidin-Peroxidase) immunohistochemistry. Western blotting was performed to determine the levels of importin13 and bcl-2 proteins in EPs.

Results: The expression levels of IPO13, c-kit, telomerase, caspase3, and bax were lower in the EP tissue compared to normal endometrial tissue during the proliferation and secretion phases of the menstrual cycle (p<0.05). The expression of CD146 was decreased in the EP tissue compared to the normal endometrial tissue during the proliferation phase of the menstrual cycle (p<0.05). The expression of bcl-2 was increased in the EP tissue compared to the normal endometrial tissue during the proliferation and secretion phases of the menstrual cycle (p<0.05).

Conclusions: The expression levels of IPO13, c-kit, telomerase, caspase3, and bax were decreased; however, the expression of bcl-2 was increased in the EP tissue compared to the normal endometrial tissue. These findings suggest that the development of EPs is associated with the deregulated activities of the endometrial stem/progenitor cells and the decreased apoptosis of endometrial cells, with the latter being the major factor involved in the development of EPs.

Figure 1

The expression of telomerase and CD146 in the endometrial tissues was detected by immunohistochemistry (400×). (A) Control endometrium at the proliferation phase. (B) Control endometrium at the secretion phase. (C) EP at the proliferation phase. (D) EP at the secretion phase. (E) Control endometrium at the proliferation phase. (F) Control endometrium at the secretion phase. (G) EP at the proliferation phase. (H) EP at the secretion phase. * p<0.05 (vs. control endometrium at the proliferation phase); ** p<0.05 (vs. control endometrium at the secretion phase); error bars, SEM.

Figure 2

The expression levels of IPO13 and caspase3 in the endometrial tissues were detected by immunohistochemistry (400×). (A) Control endometrium at the proliferation phase. (B) Control endometrium at the secretion phase. (C) EP at the proliferation phase. (D) EP at the secretion phase. (E) Control endometrium at the proliferation phase. (F) Control endometrium at the secretion phase. (G) EP at the proliferation phase. (H) EP at the secretion phase. * p<0.05 (vs. control endometrium at the proliferation phase); ** p<0.05 (vs. control endometrium at the secretion phase); error bars, SEM.

Figure 3

The expression of bax and bcl-2 in the endometrial tissues was detected by immunohistochemistry. (A) Control endometrium at the proliferation phase (400×). (B) Control endometrium at the secretion phase (400×). (C) EP at the proliferation phase (400×). (D) EP at the secretion phase (400×). (E) Control endometrium at the proliferation phase (200×). (F) Control endometrium at the secretion phase (200×). (G) EP at the proliferation phase (200×). (H) EP at the secretion phase (200×). * p<0.05 (vs. control endometrium at the proliferation phase); ** p<0.05 (vs. control endometrium at the secretion phase); error bars, SEM.

Figure 4

The mRNA expression of IPO13, c-kit, bcl-2 and bax was detected by real-time PCR. (A) Control endometrium at the proliferation phase. (IB) Control endometrium at the secretion phase. (IC) EP at the proliferation phase. (ID) EP at the secretion phase. (IIA) Control endometrium at the proliferation phase. (IIB) Control endometrium at the secretion phase. (IIC) EP at the proliferation phase. (IID) EP at the secretion phase. (IIIA) Control endometrium at the proliferation phase. (IIIB) Control endometrium at the secretion phase. (IIIC) EP at the proliferation phase. (IIID) EP at the secretion phase. (IVA) Control endometrium at the proliferation phase. (IVB) Control endometrium at the secretion phase. (IVC) EP at the proliferation phase. (IVD) EP at the secretion phase. ** p<0.05 (vs. control endometrium at the secretion phase); error bars, SEM.