Downregulating HK2 inhibits proliferation of endometrial stromal cells through a noncanonical pathway involving phosphorylation of signal transducer and activator of transcription 1 in endometriosis

Background: Endometriosis is a benign gynecologic disease that causes chronic pelvic pain, dysmenorrhea and infertility and shares several characteristics with malignant tumors, afflicting women of reproductive age. Hexokinase 2 plays an essential role as the first rate-limiting enzyme in the metabolic glycolysis pathway, and its abnormal elevation in tumors is associated with tumor genesis and metastasis. However, the expression and role of hexokinase 2 in endometriosis remain unclear. Methods: We sequenced the primary endometrial stromal cells from patients with endometrioma and utilized immunohistochemistry, quantitative real-time PCR, and western blot to determine the expression of hexokinase 2. Then wound healing assays, cell invasion assays, and cell proliferation assays were performed to explore the functions of hexokinase 2 in endometrial stromal cells. Furthermore, mice models of endometriosis were used to observe the effects of hexokinase 2 inhibitors in vivo. Lastly, glycolysis metabolism detection and transcriptome sequencing were carried out in hexokinase 2-knockdown endometrial stromal cells to analyze the mechanism of hexokinase 2 affecting cell function. Results: Endometrial stromal cells of endometrioma displayed active glycolysis metabolism and elevated expression of hexokinase 2. Downregulating hexokinase 2 reduced the migration, invasion, and proliferation capacity of endometrial stromal cells. Knockdown of hexokinase 2 induced upregulation of signal transducer and activator of transcription 1 and their phosphorylation to attenuate the proliferation of endometrial stromal cells. Conclusions: Hexokinase 2 is associated with the migration, invasion, and proliferation of endometrial stromal cells, which might provide new insights into the pathogenesis and treatment of endometriosis. Summary Sentence HK2 is upregulated in ovarian endometrioma and knockdown of HK2 induced upregulation of signal transducer and activator of transcription 1 (STAT1) and their phosphorylation to attenuate the proliferation of endometrial stromal cells. Graphical Abstract