A novel mutation of HOXA11 in a patient with septate uterus

The Estrogen Receptor α Cistrome in Human Endometrium and Epithelial Organoids

Endometrial health is affected by molecular processes that underlie estrogen responses. We assessed estrogen regulation of endometrial function by integrating the estrogen receptor α (ESR1) cistromes and transcriptomes of endometrial biopsies taken from the proliferative and mid-secretory phases of the menstrual cycle together with hormonally stimulated endometrial epithelial organoids. The cycle stage-specific ESR1 binding sites were determined by chromatin immunoprecipitation and next-generation sequencing and then integrated with changes in gene expression from RNA sequencing data to infer candidate ESR1 targets in normal endometrium. Genes with ESR1 binding in whole endometrium were enriched for chromatin modification and regulation of cell proliferation. The distribution of ESR1 binding sites in organoids was more distal from gene promoters when compared to primary endometrium and was more similar to the proliferative than the mid-secretory phase ESR1 cistrome. Inferred organoid estrogen/ESR1 candidate target genes affected formation of cellular protrusions and chromatin modification. Comparison of signaling effected by candidate ESR1 target genes in endometrium vs organoids reveals enrichment of both overlapping and distinct responses. Our analysis of the ESR1 cistromes and transcriptomes from endometrium and organoids provides important resources for understanding how estrogen affects endometrial health and function.

A de novo heterozygous HOXA11 variant in a patient with mesomelic dysplasia with urogenital abnormalities

Mesomelic dysplasias are a genetically and clinically heterogeneous group of diseases with more than 10 types defined. This article presents an 18-year-old female patient with normal intelligence and a multisystem phenotype including disproportionate short stature, scoliosis, mesomelic limb shortening, radial bowing, short fourth to fifth metacarpals and metatarsals, fusions in the carpal/tarsal bones, operated pes equinovarus, primary amenorrhea, uterine hypoplasia, vesicoureteral reflux, and chronic kidney disease. Whole-exome sequencing revealed a de novo heterozygous c.881T>G (p.Met294Arg) variant in HOXA11 (NM_005523.6) gene. The variant was located in the homeodomain of HOXA11 and predicted to alter DNA-binding ability of the protein. In silico analyses indicated that the variant could promote the alterations in the protein-protein interaction. The possible functional effect of the variant was supposed as dominant-negative. Hoxa11-mutant mice have been reported to exhibit homeotic transformations in the thoracic and sacral vertebrae, zeugopodal phenotype in forelimb and hindlimb, and urogenital abnormalities. Although mice models were reported as mesomelic dysplasia and urogenital abnormalities (MDUGA), this phenotype has not yet been reported in humans. This was the first case with MDUGA putatively related to a de novo variant in HOXA11.

Studying Müllerian duct anomalies - from cataloguing phenotypes to discovering causation

Müllerian duct anomalies (MDAs) are developmental disorders of the Müllerian duct, the embryonic anlage of most of the female reproductive tract. The prevalence of MDAs is 6.7% in the general female population and 16.7% in women who exhibit recurrent miscarriages. Individuals affected by these anomalies suffer from high rates of infertility, first-trimester pregnancy losses, premature labour, placental retention, foetal growth retardation and foetal malpresentations. The aetiology of MDAs is complex and heterogeneous, displaying a range of clinical pictures that generally lack a direct genotype-phenotype correlation. De novo and familial cases sharing the same genomic lesions have been reported. The familial cases follow an autosomal-dominant inheritance, with reduced penetrance and variable expressivity. Furthermore, few genetic factors and molecular pathways underpinning Müllerian development and dysregulations causing MDAs have been identified. The current knowledge in this field predominantly derives from loss-of-function experiments in mouse and chicken models, as well as from human genetic association studies using traditional approaches, such as microarrays and Sanger sequencing, limiting the discovery of causal factors to few genetic entities from the coding genome. In this Review, we summarise the current state of the field, discuss limitations in the number of studies and patient samples that have stalled progress, and review how the development of new technologies provides a unique opportunity to overcome these limitations. Furthermore, we discuss how these new technologies can improve functional validation of potential causative alterations in MDAs.

Summary: Here, we review the current knowledge about Müllerian duct anomalies in the context of new high-throughput technologies and model systems and their implications in the prevention of these disorders.

Downregulation of HOXA11 enhances endometrial cancer malignancy and cisplatin resistance via activating PTEN/AKT signaling pathway

PURPOSE

Endometrial cancer is the most common malignant tumor of female genital system worldwide. Homeobox A11 (HOXA11) is an evolutionarily conserved Homeobox gene closely implicated in carcinogenesis. However, the mechanisms of HOXA11 in the progression and cisplatin resistance of endometrial cancer remain unclear.

METHODS

The expression of HOXA11 was analyzed based on 548 endometrial cancer and 35 control tissues from The Cancer Genome Atlas (TCGA) database. Transwell assay was performed to investigate the effect of HOXA11 on endometrial cell migration and invasion. TUNEL staining was carried out to assay the role of HOXA11 in endometrial cell apoptosis. Western blot was employed to detect the protein levels of B cell lymphoma-2 (Bcl-2), Bcl-2 associated X (Bax), cleaved caspase-3, matrix metalloproteinase-2/9 (MMP/9), phosphatase and tensin homolog (PTEN), protein kinase B (AKT) and p-AKT.

RESULTS

TCGA data showed that HOXA11 expression was significantly down-regulated in endometrial cancer tissue samples. The overexpression of HOXA11 promoted the apoptosis, but inhibited the proliferation, migration and invasion of endometrial cancer cells. HOXA11 knockdown with small interfering RNA (siRNA) considerably repressed cell apoptosis, while promoted cell proliferation, migration, and invasion through PTEN/AKT signaling pathway. Interestingly, HOXA11 was lowly expressed in Ishikawa cells treated with cisplatin. In addition, HOXA11 knockdown increased the resistance of endometrial cancer to cisplatin through activating PTEN/AKT signaling pathway.

CONCLUSION

Low HOXA11 expression may promote the proliferation, migration, invasion of endometrial cancer cells, and increase their resistance to cisplatin through activating PTEN/AKT pathway.

Sequence variant in the CDC42BPB gene is potentially associated with Mullerian duct anomalies

AIM

Mullerian duct anomalies (MDA) are common female genital tract malformations. Genetic and environmental factors are important causes of MDA in women. Although many genes and mutations have been found to be associated with the pathogenesis of MDA, in most cases, the genetic pathogenic factors of MDA are still unknown.

METHODS

We first analyzed the three sisters using low coverage whole-genome sequencing. Then whole-exome sequencing was carried out in each patient. The identified sequence variant was confirmed by Sanger sequencing. In silico pathogenicity analysis and conservative analysis of the mutation site were also performed. Protein structural modeling was used to analyze the effect of the mutated amino acid.

RESULTS

We first analyzed the three sisters with septate uterus using low coverage whole-genome sequencing, but no possible pathogenic copy number variation was found. Then whole-exome sequencing was performed on the three sisters, and a rare homozygous variant, CDC42BPB:c.2012G>A:p.R671Q, was identified. All three patients were found with this variant. Sanger sequencing validated that this variant was segregated within the family. In silico pathogenicity analysis and conservative analysis of the mutation site suggested that the variant might be damaging. Protein structural analysis suggested that R671Q might weaken the electrostatic potential of this region, which may be a significant regulation target or protein interaction surface of CDC42BPB.

CONCLUSION

We demonstrated that CDC42BPB genetic variant might be potentially associated with the pathogenesis of MDA.