Endometriosis is characterized by ectopic endometrial-like epithelium and stroma, of which molecular characteristics remain to be fully elucidated. We sequenced 107 ovarian endometriotic and 82 normal uterine endometrial epithelium samples isolated by laser microdissection. In both endometriotic and normal epithelium samples, numerous somatic mutations were identified within genes frequently mutated in endometriosis-associated ovarian cancers. KRAS is frequently mutated in endometriotic epithelium, with a higher mutant allele frequency (MAF) accompanied by arm-level allelic imbalances. Analyses of MAF, combined with multiregional sequencing, illuminated spatiotemporal evolution of the endometriosis and uterine endometrium genomes. We sequenced 109 single endometrial glands and found that each gland carried distinct cancer-associated mutations, demonstrating the heterogeneity of the genomic architecture of endometrial epithelium. Remarkable increases in MAF of mutations in cancer-associated genes in endometriotic epithelium suggest retrograde flow of endometrial cells already harboring cancer-associated mutations, with selective advantages at ectopic sites, leading to the development of endometriosis.

Mutations in WNK kinases cause the human hypertensive disease pseudohypoaldosteronism type II (PHAII), but the regulatory mechanisms of the WNK kinases are not well understood. Mutations in kelch-like 3 (KLHL3) and Cullin3 were also recently identified as causing PHAII. Therefore, new insights into the mechanisms of human hypertension can be gained by determining how these components interact and how they are involved in the pathogenesis of PHAII. Here, we found that KLHL3 interacted with Cullin3 and WNK4, induced WNK4 ubiquitination, and reduced the WNK4 protein level. The reduced interaction of KLHL3 and WNK4 by PHAII-causing mutations in either protein reduced the ubiquitination of WNK4, resulting in an increased level of WNK4 protein. Transgenic mice overexpressing WNK4 showed PHAII phenotypes, and WNK4 protein was indeed increased in Wnk4(D561A/+) PHAII model mice. Thus, WNK4 is a target for KLHL3-mediated ubiquitination, and the impaired ubiquitination of WNK4 is a common mechanism of human hereditary hypertension.

No abstract