A novel human endometrial epithelial cell line for modeling gynecological diseases and for drug screening

Effect of Skin Barrier on Atopic Dermatitis

The skin acts as the body's primary physical and immune barrier, maintaining the skin microbiome and providing a physical, chemical, and immune barrier. A disrupted skin barrier plays a critical role in the onset and advancement of inflammatory skin conditions such as atopic dermatitis (AD) and contact dermatitis. This narrative review outlines the relationship between AD and skin barrier function in preparation for the search for possible markers for the treatment of AD.

ARID1A loss activates MAPK signaling via DUSP4 downregulation

BACKGROUND

ARID1A, a tumor suppressor gene encoding BAF250, a protein participating in chromatin remodeling, is frequently mutated in endometrium-related malignancies, including ovarian or uterine clear cell carcinoma (CCC) and endometrioid carcinoma (EMCA). However, how ARID1A mutations alter downstream signaling to promote tumor development is yet to be established.

METHODS

We used RNA-sequencing (RNA-seq) to explore transcriptomic changes in isogenic human endometrial epithelial cells after deleting ARID1A. Chromatin immunoprecipitation sequencing (ChIP-seq) was employed to assess the active or repressive histone marks on DUSP4 promoter and regulatory regions. We validated our findings using genetically engineered murine endometroid carcinoma models, human endometroid carcinoma tissues, and in silico approaches.

RESULTS

RNA-seq revealed the downregulation of the MAPK phosphatase dual-specificity phosphatase 4 (DUSP4) in ARID1A-deficient cells. ChIP-seq demonstrated decreased histone acetylation marks (H3K27Ac, H3K9Ac) on DUSP4 regulatory regions as one of the causes for DUSP4 downregulation in ARID1A-deficient cells. Ectopic DUSP4 expression decreased cell proliferation, and pharmacologically inhibiting the MAPK pathway significantly mitigated tumor formation in vivo.

CONCLUSIONS

Our findings suggest that ARID1A protein transcriptionally modulates DUSP4 expression by remodeling chromatin, subsequently inactivating the MAPK pathway, leading to tumor suppression. The ARID1A-DUSP4-MAPK axis may be further considered for developing targeted therapies against ARID1A-mutated cancers.

Case report: Successful treatment of Chidamide in a refractory/recurrent SPTCL with ARID1A mutation on the basis of CHOP plus auto-HSCT

RATIONALE

Subcutaneous panniculitis like T-cell lymphoma (SPTCL) is a rare primary cutaneous lymphoma that belongs to peripheral T cell lymphomas, of which the overall prognosis is poor. Chidamide, a deacetylase inhibitor, has been approved for the treatment of peripheral T cell lymphomas. However, due to the rare occurrence of SPTCL, it is currently unknown whether Chidamide is effective for all SPTCL patients and whether there are molecular markers that can predict its therapeutic effect on SPTCL.

PATIENT CONCERNS AND DIAGNOSES

The patient was a sixteen-year-old male and underwent subcutaneous nodule biopsy which showed SPTCL. Next-generation sequencing revealed AT-rich interaction domain 1A (ARID1A) mutation, and positron emission tomography/computed tomography showed scattered subcutaneous fluorodeoxyglucose metabolic lesions throughout the body.

INTERVENTIONS AND OUTCOMES

During the first 3 CHOP (cyclophosphamide, doxorubicin, vindesine, and prednisone) treatment, the patient relapsed again after remission, and the successive addition of methotrexate and cyclosporine did not make the patient relapsing again. Then, after adding Chidamide to the last 3 CHOP treatment, the patient was relieved again. The patient underwent autologous hematopoietic stem cell transplantation (auto-HSCT) after completing a total of 8 cycles of chemotherapy, and continued maintenance therapy with Chidamide after auto-HSCT. Currently, the patient has been in continuous remission for 35 months.

LESSONS SUBSECTIONS

This case is the first report of a refractory/recurrent SPTCL with ARID1A mutation treated with Chidamide. The treatment of Chidamide on the basis of CHOP plus auto-HSCT therapy achieved good results, suggesting that ARID1A may act as a molecular marker to predict the therapeutic effect of Chidamide on SPTCL patients, which helps to improve the precision of SPTCL treatment and the overall prognosis of SPTCL patients.

Temozolomide Sensitizes ARID1A-Mutated Cancers to PARP Inhibitors

ARID1A is a subunit of SWI/SNF chromatin remodeling complexes and is mutated in many types of human cancers, especially those derived from endometrial epithelium, including ovarian and uterine clear cell carcinoma (CCC) and endometrioid carcinoma (EMCA). Loss-of-function mutations in ARID1A alter epigenetic regulation of transcription, cell-cycle checkpoint control, and DNA damage repair. We report here that mammalian cells with ARID1A deficiency harbor accumulated DNA base lesions and increased abasic (AP) sites, products of glycosylase in the first step of base excision repair (BER). ARID1A mutations also delayed recruitment kinetics of BER long-patch repair effectors. Although ARID1A-deficient tumors were not sensitive to monotherapy with DNA-methylating temozolomide (TMZ), the combination of TMZ with PARP inhibitors (PARPi) potently elicited double-strand DNA breaks, replication stress, and replication fork instability in ARID1A-deficient cells. The TMZ and PARPi combination also significantly delayed in vivo growth of ovarian tumor xenografts carrying ARID1A mutations and induced apoptosis and replication stress in xenograft tumors. Together, these findings identified a synthetic lethal strategy to enhance the response of ARID1A-mutated cancers to PARP inhibition, which warrants further experimental exploration and clinical trial validation.

SIGNIFICANCE

The combination of temozolomide and PARP inhibitor exploits the specific DNA damage repair status of ARID1A-inactivated ovarian cancers to suppress tumor growth.

Spheroids as a model for endometriotic lesions

The development and progression of endometriotic lesions are poorly understood, but immune cell dysfunction and inflammation are closely associated with the pathophysiology of endometriosis. There is a need for 3D in vitro models to permit the study of interactions between cell types and the microenvironment. To address this, we developed endometriotic spheroids (ES) to explore the role of epithelial-stromal interactions and model peritoneal invasion associated with lesion development. Using a nonadherent microwell culture system, spheroids were generated with immortalized endometriotic epithelial cells (12Z) combined with endometriotic stromal (iEc-ESC) or uterine stromal (iHUF) cell lines. Transcriptomic analysis found 4,522 differentially expressed genes in ES compared with spheroids containing uterine stromal cells. The top increased gene sets were inflammation-related pathways, and an overlap with baboon endometriotic lesions was highly significant. Finally, to mimic invasion of endometrial tissue into the peritoneum, a model was developed with human peritoneal mesothelial cells in an extracellular matrix. Invasion was increased in the presence of estradiol or pro-inflammatory macrophages and suppressed by a progestin. Taken together, our results strongly support the concept that ES are an appropriate model for dissecting mechanisms that contribute to endometriotic lesion development.

Strategies for modelling endometrial diseases

Each month during a woman's reproductive years, the endometrium undergoes vast changes to prepare for a potential pregnancy. Diseases of the endometrium arise for numerous reasons, many of which remain unknown. These endometrial diseases, including endometriosis, adenomyosis, endometrial cancer and Asherman syndrome, affect many women, with an overall lack of efficient or permanent treatment solutions. The challenge lies in understanding the complexity of the endometrium and the extensive changes, orchestrated by ovarian hormones, that occur in multiple cell types over the period of the menstrual cycle. Appropriate model systems that closely mimic the architecture and function of the endometrium and its diseases are needed. The emergence of organoid technology using human cells is enabling a revolution in modelling the endometrium in vitro. The goal of this Review is to provide a focused reference for new models to study the diseases of the endometrium. We provide perspectives on the power of new and emerging models, from organoids to microfluidics, which have opened up a new frontier for studying endometrial diseases.