Anaplastic lymphoma kinase (ALK) inhibition using crizotinib has become the standard of care in advanced ALK-rearranged non–small cell lung cancer (NSCLC), but the treatment outcomes and duration of response vary widely. Echinoderm microtubule-associated protein-like 4 (EML4)-ALK is the most common translocation, and the fusion variants show different sensitivity to crizotinib in vitro. However, there are only limited data on the specific EML4-ALK variants and clinical responses of patients to various ALK inhibitors.

Human umbilical cord mesenchymal stromal cells (hUC-MSCs) of Wharton's jelly origin undergo adipogenic, osteogenic, and chondrogenic differentiation in vitro. Recent studies have consistently shown their therapeutic potential in various human disease models. However, the biological effects of major pregnancy complications on the cellular properties of hUC-MSCs remain to be studied. In this study, we compared the basic properties of hUC-MSCs obtained from gestational diabetes mellitus (GDM) patients (GDM-UC-MSCs) and normal pregnant women (N-UC-MSCs). Assessments of cumulative cell growth, MSC marker expression, cellular senescence, and mitochondrial function-related gene expression were performed using a cell count assay, senescence-associated β-galactosidase staining, quantitative real-time reverse transcription–polymerase chain reaction, immunoblotting, and cell-based mitochondrial functional assay system. When compared with N-UC-MSCs, GDM-UC-MSCs showed decreased cell growth and earlier cellular senescence with accumulation of p16 and p53, even though they expressed similar levels of CD105, CD90, and CD73 MSC marker proteins. GDM-UC-MSCs also displayed significantly lower osteogenic and adipogenic differentiation potentials than N-UC-MSCs. Furthermore, GDM-UC-MSCs exhibited a low mitochondrial activity and significantly reduced expression of the mitochondrial function regulatory genes ND2 , ND9 , COX1 , PGC-1α , and TFAM . Here, we report intriguing and novel evidence that maternal metabolic derangement during gestation affects the biological properties of fetal cells, which may be a component of fetal programming. Our findings also underscore the importance of the critical assessment of the biological impact of maternal–fetal conditions in biological studies and clinical applications of hUC-MSCs.

Introduction: Mismatch repair (MMR)-deficient and DNA polymerase epsilon (POLE)-mutated tumors exhibit a high tumor mutation burden (TMB) and have been proven to be associated with good responses to immune checkpoint inhibitor treatments. However, the relationship between mutational characteristics of MMR-deficient and POLE-mutated tumors and the spatial architecture of tumor-infiltrating lymphocytes (TILs) has not been fully evaluated. Methods: We retrieved microsatellite instability-high (MSI-high, N=20) and POLE-mutated (N=47) cases from the clinical next-generation sequencing cohort at Asan Medical Center. Whole-slide immunostaining for CD3, CD4, CD8, FoxP3 and PD-1 were performed with tissue samples of colorectal and gastric cancer (N=24) and the tumor-positive TIL cell densities were correlated with the tumor’s mutational features. The findings were compared with the results of similar analyses in The Cancer Genome Atlas-Colorectal Adenocarcinoma (TCGA-COADREAD) cohort (N=592). Results: The MSI-high group showed significantly higher overall TMBs with a number of insertion/deletion (indel) mutations relative to the POLE-mutated group (median TMB; 83.6 vs 12.5/Mb). Oncogenic/likely-oncogenic POLE mutations were identified with ultrahypermutations (≥100 mutations/Mb) (2/47, 4.3%). Concurrent POLE mutations of unknown significance and MSI-high cases were identified in eight cases (8/67, 11%), and two of these colorectal cancers had multiple POLE mutations, showing an ultramutated phenotype (378.1 and 484.4/Mb) and low indel mutation burdens with complete loss of MSH-6 or PMS-2, which was similar to the mutational profile of the POLE-inactivated tumors. Intratumoral CD3-positive, CD4-positive, CD8-positive, FoxP3-positive and PD-1-positive TIL cell densities were more strongly correlated with the indel mutation burden than with the total TMB (correlation coefficient, 0.61–0.73 vs 0.23–0.38). In addition, PI3K/AKT/mTOR pathway mutations were commonly found in MSI-high tumors (75%) but not in POLE-mutated tumors. Conclusions: Indel mutation burden rather than total TMB could serve as a predictor of high TILs in both MSI-high and POLE-mutated tumors. Multiple uncharacterized/non-pathogenic POLE mutations occurring via MMR deficiency within MSI-high tumors may have combined pathogenic roles. A mutated PI3K/AKT/mTOR pathway may be a biomarker that can be used to stratify patients with advanced MSI-high tumors for immune therapy.

Mesenchymal stem cells derived from Wharton’s jelly of the umbilical cord (UC-MSCs) have immunomodulatory properties. The aim of this study was to explore whether extracts of MSCs (MSC-Ex) could augment the low therapeutic efficacy of the whole cells in an Aspergillus fumigatus (Af)-induced atopic dermatitis (AD) model. LPS- or TNF-α/IFN-γ-stimulated keratinocytes (HaCaT cells) were treated with MSC-Ex, and the Af-induced AD model was established in BALB/c mice. In HaCaT cells, MSC-Ex treatment significantly reduced the inflammatory cytokine (IL-6, IL-1β, IL-4, IL-5 and TNF-α), iNOS and NF-κB levels, and upregulated the anti-inflammatory cytokines (IL-10 and TGF-β1). In the AD mice, the MSC-Ex group showed greatly reduced dermatitis, and lower clinical symptom scores and IgE levels. The histological dermatitis scores were also markedly lower in the MSC-Ex-treated animals compared with the MSC-treated group. Decreased levels of IFN-γ (Th1) and IL-17 (Th17), IL-4 and IL-13 (Th2) were detected in T cells and the skin tissue from the MSC-Ex treated AD mice. The therapeutic capacity of MSC-Ex was preserved after lyophilization and reconstitution. MSC-Ex treatment reproducibly suppresses dermatitis and inhibits the induction of inflammatory cytokines in the skin of AD mice. MSC-Ex is therefore a potential new treatment agent for AD.