Shuko Harada | Search PubMed

PubMed2025

A Genomic Alteration in GATA3 Affects Treatment Responses With a CDK4/6 Inhibitor Collaborating With p18INK4C Expression in Advanced Breast Carcinoma.

Cyclin-dependent kinase 4 and 6 inhibitor (CDK4/6i) with endocrine therapy benefits patients with hormone receptor-positive, human epidermal growth receptor 2-negative breast carcinomas. However, most tumors develop resistance to CDK4/6i during the course of therapy. Although preclinical studies have proposed molecular mechanisms for the resistance, predictive markers are yet to be discovered. We investigated the tumor molecular profiling in 42 patients with advanced-stage breast carcinoma who received CDK4/6i therapy. The tumors carrying a GATA-binding protein 3 (GATA3) gene mutation, mainly a frameshift variant, showed a better treatment response compared with other tumors. Furthermore, we explored the potential underlying mechanism of this association. To that end, nuclear expression of p18, one of the INK family proteins, was found to be positively associated with the GATA3 mutation, as well as a CDK4/6i treatment response. Therefore, our study suggests that a GATA3 gene mutation, collaborating with p18 protein expression in tumor nuclei, may have a predictive value for CDK4/6i therapy in breast carcinoma.

Humans↗

PubMed2024

Molecular Characterization of Juxtaglomerular Cell Tumors: Evidence of Alterations in MAPK-RAS Pathway.

Juxtaglomerular cell tumor (JGCT) is a rare neoplasm, part of the family of mesenchymal tumors of the kidney. Although the pathophysiological and clinical correlates of JGCT are well known, as these tumors are an important cause of early-onset arterial hypertension refractory to medical treatment, their molecular background is unknown, with only few small studies investigating their karyotype. Herein we describe a multi-institutional cohort of JGCTs diagnosed by experienced genitourinary pathologists, evaluating clinical presentation and outcome, morphologic diversity, and, importantly, the molecular features. Ten JGCTs were collected from 9 institutions, studied by immunohistochemistry, and submitted to whole exome sequencing. Our findings highlight the morphologic heterogeneity of JGCT, which can mimic several kidney tumor entities. Three cases showed concerning histologic features, but the patient course was unremarkable, which suggests that morphologic evaluation alone cannot reliably predict the clinical behavior. Gain-of-function variants in RAS GTPases were detected in JGCTs, with no evidence of additional recurrent genomic alterations. In conclusion, we present the largest series of JGCT characterized by whole exome sequencing, highlighting the putative role of the MAPK-RAS pathway.

Humans↗