Modulating aberrant transcription of oncogenes is a relatively unexplored opportunity in cancer therapeutics. In approximately 10% of multiple myelomas, the initiating oncogenic event is translocation of musculoaponeurotic fibrosarcoma oncogene homolog (MAF), a transcriptional activator of key target genes, including cyclinD2. Our prior work showed that MAF is up-regulated in an additional 30% of multiple myeloma cases. The present study describes a common mechanism inducing MAF transcription in both instances. The second mode of MAF transcription occurred in myelomas with multiple myeloma SET domain (MMSET) translocation. MMSET knockdown decreased MAF transcription and cell viability. A small-molecule screen found an inhibitor of mitogen-activated protein kinase kinase (MEK), which activates extracellular signal-regulated kinase (ERK)-MAP kinases, reduced MAF mRNA in cells representing MMSET or MAF subgroups. ERK activates transcription of FOS, part of the AP-1 transcription factor. By chromatin immunoprecipitation, FOS bound the MAF promoter, and MEK inhibition decreased this interaction. MEK inhibition selectively induced apoptosis in MAF-expressing myelomas, and FOS inactivation was similarly toxic. Reexpression of MAF rescued cells from death induced by MMSET depletion, MEK inhibition, or FOS inactivation. The data presented herein demonstrate that the MEK-ERK pathway regulates MAF transcription, providing molecular rationale for clinical evaluation of MEK inhibitors in MAF-expressing myeloma.
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http://dx.doi.org/10.1182/blood-2010-04-278788 | DOI Listing |
bioRxiv
December 2024
Departments of Ophthalmology and Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, New York 10461.
Crystallin proteins serve as both essential structural and as well as protective components of the ocular lens and are required for the transparency and light refraction properties of the organ. The mouse lens crystallin proteome is represented by αA-, αB-, βA1-, βA2-, βA3-, βA4-, βB1-, βB2-, βB3-, γA-, γB-, γC-, γD-, γE, γF-, γN-, and γS-crystallin proteins encoded by 16 genes. Their mutations are responsible for lens opacification and early onset cataract formation.
View Article and Find Full Text PDFJ Ovarian Res
January 2025
Departments of Endocrinology, Sheri Kashmir Institute of Medical Sciences, Srinagar, J&K, India.
Background: A significant overlap in the pathophysiological features of polycystic ovary syndrome (PCOS) and type 2 diabetes mellitus (T2DM) has been reported; and insulin resistance is considered a central driver in both. The expression and hepatic clearance of insulin and subsequent glucose homeostasis are mediated by TCF7L2 via Wnt signaling. Studies have persistently associated TCF7L2 genetic variations with T2DM, however, its results on PCOS are sparse and inconsistent.
View Article and Find Full Text PDFDiabetologia
December 2024
Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, Nanjing, Jiangsu, China.
Aims/hypothesis: The key pancreatic beta cell transcription factor v-maf musculoaponeurotic fibrosarcoma oncogene homologue A (MafA) is critical for the maintenance of mature beta cell function and phenotype. The expression levels and/or activities of MafA are reduced when beta cells are chronically exposed to diabetogenic stress, such as hyperglycaemia (i.e.
View Article and Find Full Text PDFJ Mol Endocrinol
February 2025
Glucose transporter type 2 (GLUT2), encoded by the Slc2a2 gene, is essential for glucose-stimulated insulin secretion (GSIS) in pancreatic islet β-cells, and low expression of GLUT2 is associated with β-cell dysfunction during the progression of type 2 diabetes in humans and animal models. Glucocorticoids are stress hormones that regulate inflammation and metabolism through the glucocorticoid receptor (GR), a member of the nuclear receptor superfamily, and synthetic glucocorticoids are widely used for the treatment of inflammatory disorders. Prolonged exposure to glucocorticoids induces β-cell dysfunction and diabetes, but the effects of Slc2a2 gene repression in β-cells, if any, and the mechanisms involved remain unclear.
View Article and Find Full Text PDFHum Reprod Open
November 2024
Departamento de Genética e Instituto de Biotecnología, Centro de Investigación Biomédica (CIBM), Universidad de Granada, Granada, Spain.
Study Question: Can genome-wide genotyping data be analysed using a hypothesis-driven approach to enhance the understanding of the genetic basis of severe spermatogenic failure (SPGF) in male infertility?
Summary Answer: Our findings revealed a significant association between SPGF and the gene and identified three novel genes (, , and ) along with 32 potentially pathogenic rare variants in 30 genes that contribute to this condition.
What Is Known Already: SPGF is a major cause of male infertility, often with an unknown aetiology. SPGF can be due to either multifactorial causes, including both common genetic variants in multiple genes and environmental factors, or highly damaging rare variants.
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