WDR26 and MTF2 are therapeutic targets in multiple myeloma

Advances in research on potential inhibitors of multiple myeloma

Multiple myeloma (MM) is a common hematological malignancy. Although recent clinical applications of immunomodulatory drugs, proteasome inhibitors and CD38-targeting antibodies have significantly improved the outcome of MM patient with increased survival, the incidence of drug resistance and severe treatment-related complications is gradually on the rise. This review article summarizes the characteristics and clinical investigations of several MM drugs in clinical trials, including their structures, mechanisms of action, structure-activity relationships, and clinical study progress. Furthermore, the application potentials of the drugs that have not yet entered clinical trials are also reviewed. The review also outlines the future directions of MM drug development.

Tissue-Specific Tumour Suppressor and Oncogenic Activities of the Polycomb-like Protein MTF2

The Polycomb repressive complex 2 (PRC2) is a conserved chromatin-remodelling complex that catalyses the trimethylation of histone H3 lysine 27 (H3K27me3), a mark associated with gene silencing. PRC2 regulates chromatin structure and gene expression during organismal and tissue development and tissue homeostasis in the adult. PRC2 core subunits are associated with various accessory proteins that modulate its function and recruitment to target genes. The multimeric composition of accessory proteins results in two distinct variant complexes of PRC2, PRC2.1 and PRC2.2. Metal response element-binding transcription factor 2 (MTF2) is one of the Polycomb-like proteins (PCLs) that forms the PRC2.1 complex. MTF2 is highly conserved, and as an accessory subunit of PRC2, it has important roles in embryonic stem cell self-renewal and differentiation, development, and cancer progression. Here, we review the impact of MTF2 in PRC2 complex assembly, catalytic activity, and spatiotemporal function. The emerging paradoxical evidence suggesting that MTF2 has divergent roles as either a tumour suppressor or an oncogene in different tissues merits further investigations. Altogether, our review illuminates the context-dependent roles of MTF2 in Polycomb group (PcG) protein-mediated epigenetic regulation. Its impact on disease paves the way for a deeper understanding of epigenetic regulation and novel therapeutic strategies.

Pathogenesis, clinical characteristics and personalized managements of multiple myeloma with chromosome 1 abnormalities

Multiple myeloma (MM) is a biologically heterogeneous malignancy defined by the proliferation of monoclonal plasma cells. Despite the tremendous advancement in MM treatment over the past decades, relapse remains a major problem which is inevitable for most patients. In particular, a partial of patients with early relapse and poor outcomes are classified as a high-risk group. Apart from the clinical stage, genetic aberrations are now recognized as important prognostic factors for identifying high-risk patients. Chromosome 1 abnormalities (C1As), particularly 1q21 gain or amplification, have been identified as common genetic aberrations in patients with MM and are often considered unfavorable prognostic markers for progression-free survival and overall survival. However, more effective therapeutic approaches are still needed to overcome the negative impact of C1As. Therefore, we summarize the prevalence, pathogenesis, clinical significance and present therapeutic condition of C1As in MM, and attempt to conclude the precise and personalized management for patients with C1As.

Polycomb-like Proteins in Gene Regulation and Cancer

Polycomb-like proteins (PCLs) are a crucial group of proteins associated with the Polycomb repressive complex 2 (PRC2) and are responsible for setting up the PRC2.1 subcomplex. In the vertebrate system, three homologous PCLs exist: PHF1 (PCL1), MTF2 (PCL2), and PHF19 (PCL3). Although the PCLs share a similar domain composition, they differ significantly in their primary sequence. PCLs play a critical role in targeting PRC2.1 to its genomic targets and regulating the functionality of PRC2. However, they also have PRC2-independent functions. In addition to their physiological roles, their dysregulation has been associated with various human cancers. In this review, we summarize the current understanding of the molecular mechanisms of the PCLs and how alterations in their functionality contribute to cancer development. We particularly highlight the nonoverlapping and partially opposing roles of the three PCLs in human cancer. Our review provides important insights into the biological significance of the PCLs and their potential as therapeutic targets for cancer treatment.

Comprehensive Pan-Cancer Analysis of MTF2 Effects on Human Tumors

Understanding oncogenic processes and underlying mechanisms to advance research into human tumors is critical for effective treatment. Studies have shown that Metal regulatory transcription factor 2（MTF2) drives malignant progression in liver cancer and glioma. However, no systematic pan-cancer analysis of MTF2 has been performed. Here, we use University of California Santa Cruz, Cancer Genome Atlas , Genotype-Tissue Expression data, Tumor Immune Estimation Resource, and Clinical Proteomic Tumor Analysis Consortium bioinformatics tools to explore differential expression of MTF2 across different tumor types. MTF2 was found to be highly expressed in the cancer lines that were available through the respective databases included in the study, and overexpression of MTF2 may lead to a poor prognosis in tumor patients such as glioblastoma multiforme, brain lower grade glioma, KIPAN, LIHC, adrenocortical carcinoma, etc. We also validated MTF2 mutations in cancer, compared MTF2 methylation levels in normal and primary tumor tissues, analyzed the association of MTF2 with the immune microenvironment, and validated the functional role of MTF2 in glioma U87 and U251 and breast cancer MDA-MB-231 cell lines by cytometry. This also indicates that MTF2 has a promising application prospect in cancer treatment.

Comprehensive characteristics of pathological subtypes in testicular germ cell tumor: Gene expression, mutation and alternative splicing

Background

Testicular germ cell tumor (TGCT) is the most common tumor in young men, but molecular signatures, especially the alternative splicing (AS) between its subtypes have not yet been explored.

Methods

To investigate the differences between TGCT subtypes, we comprehensively analyzed the data of gene expression, alternative splicing (AS), and somatic mutation in TGCT patients from the TCGA database. The gene ontology (GO) enrichment analyses were used to explore the function of differentially expressed genes and spliced genes respectively, and Spearman correlation analysis was performed to explore the correlation between differential genes and AS events. In addition, the possible patterns in which AS regulates gene expression were elaborated by the ensemble database transcript atlas. And, we identified important transcription factors that regulate gene expression and AS and functionally validated them in TGCT cell lines.

Results

We found significant differences between expression and AS in embryonal carcinoma and seminoma, while mixed cell tumors were in between. GO enrichment analyses revealed that both differentially expressed and spliced genes were enriched in transcriptional regulatory pathways, and obvious correlation between expression and AS events was determined. By analyzing the transcript map and the sites where splicing occurs, we have demonstrated that AS regulates gene expression in a variety of ways. We further identified two pivot AS-related molecules (SOX2 and HDAC9) involved in AS regulation, which were validated in embryonal carcinoma and seminoma cell lines. Differences in somatic mutations between subtypes are also of concern, with our results suggesting that mutations in some genes (B3GNT8, CAPN7, FAT4, GRK1, TACC2, and TRAM1L1) occur only in embryonal carcinoma, while mutations in KIT, KARS, and NRAS are observed only in seminoma.

Conclusions

In conclusion, our analysis revealed the differences in gene expression, AS and somatic mutation among TGCT subtypes, providing a molecular basis for clinical diagnosis and precise therapy of TGCT patients.