CASZ1 Is Essential for Skin Epidermal Terminal Differentiation.

The barrier function of skin epidermis is crucial for our bodies to interface with the environment. Because epidermis continuously turns over throughout the lifetime, this barrier must be actively maintained by regeneration. Although several transcription factors have been established as essential activators in epidermal differentiation, it is unclear whether additional factors remain to be identified. In this study, we show that CASZ1, a multi zinc-finger transcription factor previously characterized in nonepithelial cell types, shows highest expression in skin epidermis. CASZ1 expression is upregulated during epidermal terminal differentiation. In addition, CASZ1 expression is impaired in several skin disorders with impaired barrier function, such as atopic dermatitis, psoriasis, and squamous cell carcinoma. Using transcriptome profiling coupled with RNA interference, we identified 674 differentially expressed genes with CASZ1 knockdown. Downregulated genes account for 91.2% of these differentially expressed genes and were enriched for barrier function. In organotypic epidermal regeneration, CASZ1 knockdown promoted proliferation and strongly impaired multiple terminal differentiation markers. Mechanistically, we found that CASZ1 upregulation in differentiation requires the action of both the master transcription factor, p63, and the histone acetyltransferase, p300. Taken together, our findings identify CASZ1 as an essential activator of epidermal differentiation, paving the way for future studies understanding of CASZ1 roles in skin disease.

ASXL1 and STAG2 are common mutations in GATA2 deficiency patients with bone marrow disease and myelodysplastic syndrome.

Patients with GATA2 deficiencyharbor de novo or inherited germline mutations in the GATA2 transcription factor gene, predisposing them to myeloid malignancies. There is considerable variation in disease progression, even among family members with the same mutation in GATA2. We investigated somatic mutations in 106 patients with GATA2 deficiency to identify acquired mutations that are associated with myeloid malignancies. Myelodysplastic syndrome (MDS) was the most common diagnosis (∼44%), followed by GATA2 bone marrow immunodeficiency disorder (G2BMID; ∼37%). Thirteen percent of the cohort had GATA2 mutations but displayed no disease manifestations. There were no correlations between age or sex with disease progression or survival. Cytogenetic analyses showed a high incidence of abnormalities (∼43%), notably trisomy 8 (∼23%) and monosomy 7 (∼12%), but the changes did not correlate with lower survival. Somatic mutations in ASXL1 and STAG2 were detected in ∼25% of patients, although the mutations were rarely concomitant. Mutations in DNMT3A were found in ∼10% of patients. These somatic mutations were found similarly in G2BMID and MDS, suggesting clonal hematopoiesis in early stages of disease, before the onset of MDS. ASXL1 mutations conferred a lower survival probability and were more prevalent in female patients. STAG2 mutations also conferred a lower survival probability, but did not show a statistically significant sex bias. There was a conspicuous absence of many commonly mutated genes associated with myeloid malignancies, including TET2, IDH1/2, and the splicing factor genes. Notably, somatic mutations in chromatin-related genes and cohesin genes characterized disease progression in GATA2 deficiency.

miR-181c regulates MCL1 and cell survival in GATA2 deficient cells.

GATA2 is a transcription factor critical for hematopoiesis. Germline mutations in GATA binding protein 2 (GATA2) led to haploinsufficiency, severe cytopenias of multiple cell lineages, susceptibility to infections and strong propensity to develop myelodysplastic syndrome, and acute myeloid leukemia. Mechanisms of progressive cytopenias remain unclear. MicroRNA (miRNA) represents a unique mechanism of post-transcriptional gene regulation. In this study, miRNA profiles were evaluated and eight miRNAs were found to be differentially expressed (≥2-fold, P ≤ 0.05) in patient-derived cell lines (N = 13) in comparison to controls (N = 10). miR-9, miR-181a-2-3p, miR-181c, miR-181c-3p, miR-486-3p, and miR-582 showed increased expression, whereas miR-223 and miR-424-3p showed decreased expression. Cell death assays indicated that miR-181c potently induces cell death in lymphoid (Ly-8 and SP-53) and myeloid (HL-60) cell lines. miR-181c was predicted to target myeloid cell leukemia (MCL)1, which was confirmed by transfection assays, resulting in significantly reduced MCL1 mRNA and decreased live cell numbers. Bone marrow analysis of 34 GATA2 patients showed significantly decreased cellularity, CD34-positive cells, monocytes, dendritic cells, NK cells, B cells, and B cell precursors in comparison to healthy controls (N = 29; P < 0.001 for each), which was accompanied by decreased levels of MCL1 (P < 0.05). GATA2 expression led to significant repression of miR-181c expression in transfection experiments. Conversely, knockdown of GATA2 led to increased miR-181c expression. These findings indicate that miR-181c expression is increased and MCL1 levels decreased in GATA2 deficiency cells, and that GATA2 represses miR-181c transcription. Increased miR-181c may contribute to elevated cell death and cytopenia in GATA2 deficiency potentially through down-regulation of MCL1.

Oh, the Mutations You'll Acquire! A Systematic Overview of Cutaneous Squamous Cell Carcinoma.

Nearly two million cases of cutaneous squamous cell carcinoma (cSCC) are diagnosed every year in the United States alone. cSCC is notable for both its prevalence and its propensity for invasion and metastasis. For many patients, surgery is curative. However, patients experiencing immunosuppression or recurrent, advanced, and metastatic disease still face limited therapeutic options and significant mortality. cSCC forms after decades of sun exposure and possesses the highest known mutation rate of all cancers. This mutational burden complicates efforts to identify the primary factors driving cSCC initiation and progression, which in turn hinders the development of targeted therapeutics. In this review, we summarize the mutations and alterations that have been observed in patients' cSCC tumors, affecting signaling pathways, transcriptional regulators, and the microenvironment. We also highlight novel therapeutic opportunities in development and clinical trials.

Differential processing of high-molecular-weight kininogen during normal pregnancy.

RATIONALE: Studies identified kininogen as a potential biomarker of preeclampsia, a major cause of adverse maternal outcomes. High-molecular-weight kininogen (HK) and its activated form participate in numerous pathways associated with establishing and maintaining pregnancy. However, dynamic changes in HK and naturally occurring HK-derived peptides during the natural course of pregnancy are largely unknown. METHODS: Longitudinal serum samples during the course of normal pregnancy (trimesters T1, T2, T3) from 60 pregnant women were analyzed by western blot with an anti-HK antibody. Circulating peptides in longitudinal serum specimens derived from 50 participants were enriched using nanoporous silica thin films. Peptides were identified by liquid chromatography/tandem mass spectrometry (LC/MS/MS) and database searching. Relative quantification was performed using MaxQuant and in-house scripts. Normality was evaluated by either ANOVA or Friedman tests with p < 0.05 for statistical significance. RESULTS: Western blotting revealed that HK significantly decreased during normal pregnancy (T1 vs T2, p < 0.05; T1 vs T3, p < 0.0001). A 100 kDa intermediate increased during pregnancy (T1 vs T2, p < 0.005; T1 vs T3, p < 0.01). Moreover, the heavy chain (T1 vs T2, p < 0.0001; T1 vs T3, p < 0.0001; T2 vs T3, p < 0.01) and light chain (T1 vs T2, p < 0.0001; T1 vs T3, p < 0.0001; T2 vs T3, p < 0.05) significantly increased during pregnancy. LC/MS/MS analysis identified 180 kininogen-1 peptides, of which 167 mapped to domain 5 (D5). Seventy-three peptides with ten or more complete data sets were included for further analysis. Seventy peptides mapped to D5, and 3, 24, and 43 peptides showed significant decrease, no trend, and significant increase, respectively, during pregnancy. CONCLUSIONS: This study demonstrates dynamic changes in HK and naturally occurring HK-derived peptides during pregnancy. Our study sheds light on the gestational changes of HK and its peptides for further validation of them as potential biomarkers for pregnancy-related complications.