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Establishment of the DNA methylation landscape of mammalian oocytes, mediated by the DNMT3A-DNMT3L complex, is crucial for reproduction and development. In mouse oocytes, high levels of DNA methylation occur exclusively in the transcriptionally active regions, with moderate to low levels of methylation in other regions. Histone H3K36me3 mediates the high levels of methylation in the transcribed regions; however, it is unknown which histone mark guides the methylation in the other regions. Here, we show that, in mouse oocytes, H3K36me2 is highly enriched in the X chromosome and is broadly distributed across all autosomes. Upon H3K36me2 depletion, DNA methylation in moderately methylated regions is selectively affected, and a methylation pattern unique to the X chromosome is switched to an autosome-like pattern. Furthermore, we find that simultaneous depletion of H3K36me2 and H3K36me3 results in global hypomethylation, comparable to that of DNMT3A depletion. Therefore, the two histone marks jointly provide the chromatin platform essential for guiding DNMT3A-dependent DNA methylation in mouse oocytes.

Pancreatic islet inflammation plays a crucial role in the etiology of type 2 diabetes (T2D). Macrophages residing in pancreatic islets have emerged as key players in islet inflammation. Macrophages express a plethora of innate immune receptors that bind to environmental and metabolic cues and integrate these signals to trigger an inflammatory response that contributes to the development of islet inflammation. One such receptor, Dectin-2, has been identified within pancreatic islets; however, its role in glucose metabolism remains largely unknown. Here we have demonstrated that mice lacking Dectin-2 exhibit local inflammation within islets, along with impaired insulin secretion and β-cell dysfunction. Our findings indicate that these effects are mediated by proinflammatory cytokines, such as interleukin (IL)-1α and IL-6, which are secreted by macrophages that have acquired an inflammatory phenotype because of the loss of Dectin-2. This study provides novel insights into the mechanisms underlying the role of Dectin-2 in the development of islet inflammation., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Postoperative recurrence occurs in approximately half of patients with non-small cell lung cancer (NSCLC), even after complete resection. Disease recurrence after surgical resection reduces the patient's life expectancy sharply. The prognosis after postoperative recurrence is considered to largely depend on both the mode of first recurrence (distant, locoregional or combined) and the treatment modality: (1) The majority of cases of postoperative recurrence involve distant metastasis with or without locoregional recurrence. Platinum-based systemic chemotherapy is practically accepted as the treatment for these diseases on the basis of evidence for original stage IV disease. The advent of both pemetrexed and molecular-targeted drugs has improved the survival of nonsquamous NSCLC and changed the chemotherapeutic algorithm for NSCLC; (2) Among patients with distant metastatic recurrence without locoregional recurrence at the primary tumor site, the metastasis is often limited in both organ and number. Such metastases are referred to as oligometastases. Local therapy, such as surgical resection and radiotherapy, has been suggested to be the first-line treatment of choice for oligometastatic recurrence; and (3) While locoregional recurrence is likely to cause troublesome symptoms, it is a potentially limited disease. Therefore, providing local control is important, and radiation is usually beneficial for treating local recurrence. In order to obtain better control of the disease and provide treatment with curative intent in patients with limited disease, the administration of concurrent platinum-based chemoradiotherapy is recommended according to the results of originally nonresectable stage IIIA and IIIB disease.

Many malignant tumors including non-small cell lung cancer (NSCLC) express or over-express EGFR that have shown correlations with rapid growth, metastases, resistance to conventional chemotherapy or radiotherapy, and poor prognosis. Gefitinib is a potent and selective inhibitor of EGFR tyrosine kinase (EGFRTK). Gefitinib specifically inhibited EGF-stimulated cell proliferation in vitro and it also exhibited a broad anti-tumor spectrum against NSCLC, prostate, colorectal, and ovarian cancers in vivo. Gefitinib showed dose-dependent and reversible reduction of c-fos mRNA level and decreased Ki67 significantly in tumors in vivo. In in vitro studies, gefitinib arrested the cell cycle at G1 phase by inducing intrinsic cyclin-dependent kinase (cdk) inhibitors and following inhibition of cdk2. Apoptosis was also seen in gefitinib-treated tumor cells and skin biopsy samples from clinical study. Gefitinib inhibited VEGF production in tumor cells through inhibition of EGFR signaling, leading to suppression of angiogenesis. In clinical studies, gefitinib demonstrated therapeutic benefit in patients who failed conventional chemotherapy. No correlation has been established between the anti-tumor activity of gefitinib and EGFR expression level, whilst sensitivity factors to gefitinib are yet to be elucidated. Identification of sensitivity factors will be a key for effective use of EGFRTK inhibitors including gefitinib for cancer treatment.

From immunohistochemical and ligand-binding studies, it is known that the epidermal growth factor receptor (EGFR), a member of the erbB family of receptors, is expressed in tissues of epithelial, mesenchymal and neuronal origin and plays a major role in normal cellular processes such as proliferation, differentiation and development. EGFR is highly expressed in a number of solid tumours and its expression correlates with tumour progression, resistance to chemotherapy and a poor prognosis; it is consequently an attractive target for the rational design of novel anticancer agents. Knowledge of the role of EGFR in normal tissues will help the understanding of the adverse events associated with such agents. Studies in knockout mice and preclinical toxicology studies have shown that the major effects of inhibiting the EGFR are skin and gastrointestinal toxicities. Clinical studies with inhibitors of EGFR, such as gefitinib, cetuximab and erlotinib, have shown a favourable adverse-event profile, primarily consisting of skin and gastrointestinal toxicities, as predicted from the mechanism-based effects observed in preclinical studies.