Rebecca C Rancourt | Search PubMed

PubMed2026

Regulatory mechanisms of maternal imprinting at the murine Dlk1-Dio3 domain.

Genomic imprinting is an epigenetic process causing parent-of-origin specific gene expression. The Dlk1-Dio3 domain is one of the largest imprinted clusters. While DNA methylation at an intergenic CpG-island (IG-CGI) within the imprinting control region (ICR) controls expression from the paternal chromosome, mechanisms regulating the unmethylated maternal chromosome remain unknown. Within the transcriptional regulatory element (IG-TRE) of the ICR, deletions identified a minimal region in vitro exhibiting both silencing and enhancing activity, with SOX2 and ZFP281 contributing to enhancer function on the maternal chromosome. In vivo, however, this deletion did not affect maternal expression in mouse embryos; instead it activated Dlk1 on both parental chromosomes. Combining deletion of this IG-TRE with the lethal IG-CGI deletion rescued lethality in mice by balancing Dlk1 expression, despite persistent maternal gene upregulation. These results demonstrate that loss of expression at this domain is more detrimental than gain, highlighting the importance of in vivo analysis. Identification of active regulatory factors on the unmethylated maternal chromosome challenges the prevailing view that imprinting is primarily a methylation-driven phenomenon, further revealing the sophisticated hierarchical mechanisms governing imprinting control.

Animals↗

PubMed2026

Large cell neuroendocrine carcinoma of the lung: Current standards, emerging targets, and translational foundations.

Pulmonary large cell neuroendocrine carcinoma (LCNEC) is one of the most complex and heterogenous clinical entities in thoracic oncology, sharing features with both non-small cell lung cancer (NSLC) and neuroendocrine lung cancers. LCNEC diagnosis and classification relies on evolving histopathological and molecular criteria that define its diagnostic boundaries. Recent advances have confirmed the dual nature of LCNEC, with distinct small cell-like and non-small cell-like molecular characteristics, which guide treatment decisions. In this review, we synthesize current evidence on the diagnosis, molecular characterization, and multimodality management of LCNEC to provide a comprehensive framework for clinical and translational decision-making. A comprehensive literature search was conducted using the PubMed database with no date restrictions, last updated on 12th of April 2026. Articles were selected based on relevance to the diagnosis, molecular characterization, and management of pulmonary LCNEC. Emphasis was placed on studies providing clinical, pathological, and molecular insights into the field. In this review, we summarize contemporary diagnostic approaches, including the expanding role of immunohistochemistry, next‑generation sequencing, and integrated morpho‑molecular assessment. This review represents a consolidated update on LCNEC genomic and transcriptional landscapes, and actionable molecular alterations that are anticipated to impact treatment decisions. Additionally, it provides a state-of-the-art overview of multimodality management, covering surgical approaches, radiotherapy, perioperative therapy, systemic treatment, and the emerging role of immunotherapy. Despite incremental progress, LCNEC remains constrained by limited prospective data and lack of consensus on optimal treatment pathways. By conducting literature review, we identified persistent gaps in LCNEC published data and hereby highlight key priorities for future research.

Humans↗