Effect of SMARCB1 deficiency in renal medullary carcinoma (RMC) on genes associated with nucleosome assembly and telomere organization.

Authors

null

Pavlos Msaouel

UT MD Anderson Cancer Center, Houston, TX

Pavlos Msaouel , Gabriel G. Malouf , Xiaoping Su , Hui Yao , Durga N Tripathi , Jianjun Gao , Priya Rao , Rong He , Jose A. Karam , Christopher G. Wood , Cheryl Lyn Walker , Nizar M. Tannir

Organizations

UT MD Anderson Cancer Center, Houston, TX, Pitié-Salpêtrière Hospital, Paris, France, Baylor College of Medicine, Houston, TX

Research Funding

Conquer Cancer Foundation of the American Society of Clinical Oncology

Background: RMC is a highly aggressive tumor with close to universal fatality despite therapy. It is almost exclusively found in young African-Americans with sickle cell trait, and is characterized by complete loss of expression of SMARCB1, a major chromatin remodeler involved in regulation of gene expression. We investigated the effects of SMARCB1 loss on mutation frequency, gene expression, and cell growth in RMC. Methods: Whole exome sequencing (WES) and RNA sequencing (RNA-seq) were performed in RMC tissues from 15 and 11 patients respectively, each with matched adjacent normal kidney tissue controls. In vitro experiments were performed in a cell line (RMC2C) we established from a patient with RMC. SMARCB1 was conditionally re-expressed using a tetracycline-inducible lentivector. Gene ontology (GO) analysis was performed using DAVID. Results: WES showed that RMC harbors a low number (median of < 25/tumor sample) of non-synonymous exomic single nucleotide variants (SNVs) or small indels. GO analysis revealed that the most significant pathways upregulated in RMC compared with normal tissue were those associated with nucleosome assembly and telomere organization (p values < 0.0001). Re-expression of SMARCB1 at near-endogenous levels suppressed the growth rate of RMC2C cells. Subsequent silencing of SMARCB1 expression restored the growth rate of these cells. RNA-seq of RMC2C cells expressing SMARCB1 demonstrated that the most significant downregulated pathways compared with SMARCB1-negative RMC2C cells were those associated with nucleosome assembly and telomere organization (p values < 0.0001). Conclusions: RMC harbors a remarkably simple genome, as evidenced by our WES analysis. Therefore, consistently detected alterations, such as SMARCB1 loss, are likely to serve as drivers for this disease. Indeed, in vitro restoration of SMARCB1 expression suppressed the growth of RMC cells and repressed genes associated with nucleosome assembly and telomere organization, identifying for the first time a causal link between loss of SMARCB1 and dysregulation of these genes. These results provide the basis for future therapeutic strategies targeting SMARCB1 loss in RMC.

Disclaimer

This material on this page is ©2024 American Society of Clinical Oncology, all rights reserved. Licensing available upon request. For more information, please contact licensing@asco.org

Abstract Details

Meeting

2018 Genitourinary Cancers Symposium

Session Type

Poster Session

Session Title

Poster Session C: Renal Cell Cancer

Track

Renal Cell Cancer

Sub Track

Renal Cell Cancer

Citation

J Clin Oncol 36, 2018 (suppl 6S; abstr 614)

DOI

10.1200/JCO.2018.36.6_suppl.614

Abstract #

614

Poster Bd #

G7

Abstract Disclosures

Funded by Conquer Cancer

Similar Abstracts

Abstract

2023 ASCO Annual Meeting

Aristolochic acid (AA) exposure and telomere maintenance mechanism in liver angiosarcoma (AS).

First Author: Tom Wei-Wu Chen

First Author: Kaiwen Zhou

First Author: Chao Dai