Stanniocalcin 2 is induced by estrogen and promotes growth in endometrial cancer via AMPK pathway

Stanniocalcin 2 (STC2) is identified as a glycosylated peptide hormone and estrogen-responsive gene in cancer cells. STC2 participates in angiogenesis, cell development, cytoprotection, and calcium and phosphate regulation during the development of cancer. The role of STC2 in endometrial cancer (EC) remains unclear. The data from the bioinformatic and immunohistochemical analysis showed that STC2 was upregulated in the EC tissues. The EC cells were treated with 17β-estradiol (E2), and 0.1 μmol/L E2 increased the expression of STC2 in the EC cells. E2 also increased cell viability, promoted proliferation, and inhibited apoptosis of EC. However, the knockdown of STC2 decreased cell viability, reduced proliferation, and promoted apoptosis of E2-stimulated EC. Moreover, silencing of STC2 attenuated E2-induced downregulation of phosphorylated-AMP-activated protein kinase (AMPK) in the EC cells. The loss of STC2 reduced E2-stimulated tumor growth EC in vivo. In conclusion, STC2 deficiency suppressed E2-stimulated proliferation and tumor growth of EC through the activation of AMPK signaling.