Altered Expression of Candidate Genes in Mayer–Rokitansky–Küster–Hauser Syndrome May Influence Vaginal Keratinocytes Biology: A Focus on Protein Kinase X

SIMPLE SUMMARY: Women affected by Mayer–Rokitansky–Küster–Hauser (MRKH) syndrome show an underdeveloped or absent vagina and uterus, frequently in association with renal defects. The aetiology of MRKH syndrome is controversial. Only a few cases could be related to genetic anomalies, while the vast majority of them lack a precise molecular cause. We found that protein kinase X (PRKX) levels are upregulated in vaginal keratinocytes from MRKH patients with respect to healthy women. Through in vitro investigations, we highlighted that PRKX ectopic overexpression is able to influence vaginal keratinocytes’ cell shape and motility through the induction of epithelial-to-mesenchymal transition (EMT). Moreover, PRKX ectopic overexpression exerts a broad effect on the expression of HOX genes, which encode for essential factors implicated in embryo organogenesis. The present study suggests a possible molecular cause for MRKH syndrome and a role for PRKX in vaginal keratinocyte biology. ABSTRACT: Mayer–Rokitansky–Küster–Hauser (MRKH) syndrome is a rare and complex disease defined by congenital aplasia of the vagina and uterus in 46,XX women, often associated with kidney and urinary tract anomalies. The aetiopathogenesis of MRKH syndrome is still largely unknown. Herein, we investigated the role of selected candidate genes in the aetiopathogenesis of MRKH syndrome, with a focus on PRKX, which encodes for protein kinase X. Through RT-qPCR analyses performed on vaginal dimple samples from patients, and principal component analysis (PCA), we highlighted a phenotype-related expression pattern of PRKX, MUC1, HOXC8 and GREB1L in MRKH patients. By using an in vitro approach, we proved that PRKX ectopic overexpression in a cell model of vaginal keratinocytes promotes cell motility through epithelial-to-mesenchymal transition (EMT) activation, a fundamental process in urogenital tract morphogenesis. Moreover, our findings showed that PRKX upregulation in vaginal keratinocytes is able to affect transcriptional levels of HOX genes, implicated in urinary and genital tract development. Our study identified the dysregulation of PRKX expression as a possible molecular cause for MRKH syndrome. Moreover, we propose the specific role of PRKX in vaginal keratinocyte biology as one of the possible mechanisms underlying this complex disease.