PubMed HealthSearch

SEARCH · PubMed Health

Results for “PBRM1”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

8 recordsLinked to original sources

Loss of PBRM1 accelerates pancreatic cancer progression by inducing acquisition of mesenchymal phenotype and inflammatory cancer-associated fibroblasts reprogramming.

BACKGROUND: PBRM1 is an important subunit of the SWI/SNF complex, which broadly regulates gene transcription by chromatin remodeling. Genomic alterations of PBRM1 have been found in patients with pancreatic ductal adenocarcinoma (PDAC), but its molecular functions remain unclear. METHODS: Clinical relevance of PBRM1 was analyzed by using human PDAC samples and public genomic datasets. Mice with concomitant pancreas-specific Pbrm1 deletion in Kras-driven genetic PDAC models were generated. Single-cell transcriptomics were performed to determine tumor phenotype and microenvironment reprogramming. RESULTS: Reduction of PBRM1 expression was observed in human PDAC tissues and correlated with poor prognosis and metastasis. Pbrm1 loss promoted ductal metaplasia and delayed epithelial recovery in mice with caerulein-induced pancreatic injury. In PDAC model with either mutant Kras alone or in combination with Trp53 mutation, lack of Pbrm1 markedly accelerated tumor development and progression. Bulk transcriptomics and scRNA-seq identified reprogramming of both tumor compartment with mesenchymal phenotype acquisition and stroma compartment with inflammatory cancer-associated fibroblasts (iCAFs) transformation. Mechanistically, Pbrm1 deletion induced Zeb1 upregulation through epigenetic chromatin remodeling, thereby enhancing epithelial-mesenchymal and basal-like subtype transition. CONCLUSIONS: These findings indicated a tumor-suppressing role of PBRM1 in PDAC. PBRM1-deficient PDAC constitutes a specific subgroup of patients with aggressive phenotype and prognostic significance.

Animals

The fall of the genome protectors triad: PBRM1, SETD2, and BAP1's impact on metabolism and immunity in clear cell renal cell carcinoma.

The loss of chromosome 3p and the inactivation of the tumor suppressor gene von Hippel-Lindau (VHL) were identified in clear cell renal cell carcinomas (ccRCC) over three decades ago. Since then, mutations in genes for the three chromatin modulators, polybromo 1 (PBRM1), SET domain-containing 2 (SETD2), and BRCA1-associated protein-1 (BAP1), have been recognized as common in ccRCC. Although these genomic alterations are central to understanding ccRCC's development, other deregulated cellular processes are also prominent in these tumors. Metabolic reprogramming is a key hallmark of this disease, characterized by various changes linked to the stabilization of hypoxia-inducible factors (HIF), including increased aerobic glycolysis, elevated lipid levels, and glutamine dependence for cell survival. Additionally, HIF-α stabilization plays a crucial role in regulating the immune system, thereby enhancing CD8+ T lymphocyte cytotoxicity. Immune checkpoint inhibitors (ICI) are now used as first-line treatments to target the often highly infiltrated tumor microenvironment of ccRCC. However, the effectiveness of ICI varies and is difficult to predict. Although emerging studies are beginning to provide insight, evidence suggests roles for PBRM1, SETD2, and BAP1 in metabolic regulation and in shaping the tumor immune microenvironment in ccRCC. Here, we review recent advances in this field and examine their impact on the management of ccRCC.

BAP1

Distinct endogenous retroviruses are expressed in mutational subtypes of clear cell renal cell carcinoma and are linked to improved clinical outcomes.

Distinct mutations in chromatin regulators and aberrant expression of transposable elements (TEs), have been associated with clinical benefit to immunotherapy (IO) in specific clear cell renal cell carcinoma (ccRCC) clinical contexts. However, the relationship between mutations in chromatin regulators and TE expression, and their effect on clinical outcomes, are incompletely understood. Here, we identified TEs expressed in distinct mutational subtypes of ccRCC, with endogenous retroviruses (ERVs) comprising the majority of TEs observed. Of these, ERVs 544 and 2014 were upregulated in PBRM1 mutant samples. Patients with high expression of these ERVs and somatic PBRM1 mutations had improved progression-free survival with IO monotherapy, but not targeted therapy, and their upregulation associated with expression of innate immune pathways. Chromatin accessibility increased at ERV 544 and 2014 loci in PBRM1-deficient ccRCC cells, and ERV 544 and 2014 were upregulated upon in vitro PBRM1 knockout in ccRCC cell line clones. Broadly, our study supports a link between PBRM1 mutations, subsequent chromatin accessibility changes, and aberrant but immunoresponsive ERVs in ccRCC.

CP: cancer

Co-occurrence of bronchiolar adenoma and lung adenocarcinoma: a study of nine cases revealing distinct clonal origins via integrated histologic, immunophenotypic and molecular analysis.

PURPOSE: This study sought to elucidate the possible biological association between BA and lung adenocarcinoma through an analysis of cases in which both lesions coexist within the same specimen. METHODS: In our cohort, the BA and lung cancer components of nine concurrent-type BAs were microdissected using the Millisect system and subjected to whole-exome sequencing (WES). Their histopathological, immunohistochemical, and genomic profiles were comparatively evaluated. RESULTS: Histopathologically, the BA regions of concurrent-type BAs exhibited a classic bilayered architecture, composed of continuous luminal and basal cell layers. The adjacent monolayered concurrent components were diagnosed as adenocarcinoma in situ (AIS, N = 4), minimally invasive adenocarcinoma (MIA, N = 2), and invasive adenocarcinoma (ADC, N = 3). Immunohistochemically, both luminal and basal cells in BA regions expressed thyroid transcription factor 1 (TTF1), albeit with more heterogeneous staining intensity compared to that observed in tumor components. Molecularly, EGFR mutations were the most frequently identified in either BA or tumor components, or in both (Case 9). In BA components, mutations included exon 19 p.S752F, exon 19 deletions (p.L747_T751delinsP and p.E746_T751delinsVP), and compound G719C/S768I mutations. Tumor components harbored exon 28 S1130C, exon 19 indel (p.E746_S752delins), and exon 18 p.G719C mutations. Notably, only three cases demonstrated limited overlap of mutations and copy number variations (CNVs) between the two components. Phylogenetic analysis revealed that six cases shared truncal alterations in genes including KMT2A, PIK3CA, SETD2, MITF, PBRM1, and SRSF3, one case harbored a shared canonical EGFR mutation (p.G719C), with an additional p.S768I alteration uniquely detected in the BA component. CONCLUSION: There is insufficient evidence to support BA as a premalignant lesion for lung adenocarcinoma base on morphological and molecular variables, and they may represent distinct pathological entities.

Concurrent-type bronchiolar adenoma

Understanding the biological processes of kidney carcinogenesis: an integrative multi-omics approach.

Biological mechanisms related to cancer development can leave distinct molecular fingerprints in tumours. By leveraging multi-omics and epidemiological information, we can unveil relationships between carcinogenesis processes that would otherwise remain hidden. Our integrative analysis of DNA methylome, transcriptome, and somatic mutation profiles of kidney tumours linked ageing, epithelial-mesenchymal transition (EMT), and xenobiotic metabolism to kidney carcinogenesis. Ageing process was represented by associations with cellular mitotic clocks such as epiTOC2, SBS1, telomere length, and PBRM1 and SETD2 mutations, which ticked faster as tumours progressed. We identified a relationship between BAP1 driver mutations and the epigenetic upregulation of EMT genes (IL20RB and WT1), correlating with increased tumour immune infiltration, advanced stage, and poorer patient survival. We also observed an interaction between epigenetic silencing of the xenobiotic metabolism gene GSTP1 and tobacco use, suggesting a link to genotoxic effects and impaired xenobiotic metabolism. Our pan-cancer analysis showed these relationships in other tumour types. Our study enhances the understanding of kidney carcinogenesis and its relation to risk factors and progression, with implications for other tumour types.

Kidney Neoplasms

Molecular and Immune Landscape of Recurrent and/or Distant Metastatic Squamous Cell Carcinoma of the Head and Neck: An EORTC/IMMUCAN Project.

PURPOSE: Recurrent and/or metastatic (R/M) squamous cell carcinoma of the head and neck (SCCHN) is a heterogeneous clinical entity with a poor prognosis. The molecular and immune landscape of R/M SCCHN is underexplored. To offer a comprehensive view of the tumor microenvironment and molecular profile of R/M SCCHN, we performed an in-depth molecular and immune characterization, evaluating the impact of human papillomavirus (HPV) status, tobacco and alcohol history, primary tumor site, relapse pattern, and treatment history at the genomic, transcriptomic, and immune levels. EXPERIMENTAL DESIGN: We analyzed 253 R/M SCCHN fresh tumor biopsies from the IMMUcan project using RNA sequencing (RNA-seq), whole-exome sequencing, and multiplex immunofluorescence (mIF). RESULTS: The primary clinical factor affecting the immune microenvironment was the number of treatment lines, with significant declines in T cells and B cells observed via mIF and RNA-seq as the number of R/M treatment lines progressed. IL6, IL13, IL15, and NRF2 pathways were enriched in HPV-negative R/M SCCHN compared with HPV-positive tumors, whereas no immune differences were detected between these two clinical groups. Specific genomic alterations were observed in laryngeal cancer (DDR2, FOXP1, KLF5, and ROBO2), whereas nonsmokers/nondrinkers exhibited alterations in SPEN, PBRM1, and CYLD. 11q13.3 amplification was linked to HPV-negative metastatic tumors and hypopharyngeal cancer. HPV-negative SCCHN with locoregional recurrence showed elevated EGFR and CXCL12 pathway activity. Partial epithelial-mesenchymal transition transcriptomic signatures correlated with poor survival, whereas lymphocyte infiltration, especially in the context of tertiary lymphoid structures, was associated with improved survival. CONCLUSIONS: Our study highlights key molecular and immune differences across R/M SCCHN subgroups, identifies potential biomarkers, and suggests biological rationales for tailored therapeutic strategies.

Humans

The Role of Homologous Recombination Deficiency (HRD) in Renal Cell Carcinoma (RCC): Biology, Biomarkers, and Therapeutic Opportunities.

Renal Cell Carcinoma (RCC) is a common malignancy, often diagnosed incidentally. In recent years, the prognosis of metastatic disease has been improved due to the development of immune checkpoint inhibitors (ICI) and tyrosine kinase inhibitors (TKI) as first-line treatments. However, when progression occurs, the therapeutic options are limited. Understanding crucial biological pathways could lead to a greater understanding of the natural history of the disease, which could help to overcome the mechanism of resistance and to develop new treatments. The clinical significance of homologous recombination deficiency (HRD) in RCC remains to be investigated. To improve the knowledge about this topic, we conducted a narrative review to summarize the current evidence on HRD-related variations and signatures in RCC, together with their prognostic and predictive implications. Preliminary evidence indicates that canonical HRD variants (BRCA1/2) are infrequent in RCC, while broader DNA damage response (DDR) alterations like BAP1, PBRM1, ATM, and SETD2 are more prevalent. Elevated HRD genomic scores in clear-cell RCC correlate with a worse prognosis and an immunologically exhausted microenvironment. From a therapeutic point of view, PARP inhibitor monotherapy has exhibited initial efficacy in small cohorts with high levels of DDR mutation, yet remains investigational for RCC.

Humans