BRDT promotes ovarian cancer cell growth

Ectopic expression of testis-specific transcription elongation factor in driving cancer

The testis-specific BET protein BRDT structurally resembles the ubiquitous BRD4 and is misexpressed in cancer, and we show that BRDT misexpression may affect lung cancer progression. BRDT knockdown in lung cancer cells slowed tumor growth and prolonged survival in a xenograft model. Comparative characterization of PTEFb complex participation and chromatin binding indicates BRD4-redundant and BRD4-distinct BRDT functions. Unlike dual depletion, individual BRD4 or BRDT knockdown did not impair transcriptional responses to hypoxia in BRDT-expressing cells, consistent with redundant function. However, BRD4 depletion/BRDT complementation revealed that BRDT can also release paused RNA polymerase II independently of its bromodomains as we previously demonstrated not to be required for Pol II pause/release function of BRD4, underscoring the functional importance of the C-terminal domains in both BRD4 and BRDT and their potential as therapeutic targets in solid tumors. Based on this study, future investigations should explore BRD4-distinct BRDT functions and BRDT misexpression driving cancer pathogenesis.

A p-n heterojunction sonosensitizer for improved sono-immunotherapy via induction of multimodal cell death mechanisms

Rationale: Activating a robust immune system is a crucial strategy for combating solid tumors and preventing recurrences. Studies have shown that cuproptosis and the resulting increased reactive oxygen species (ROS) can trigger immunogenic cell death (ICD) and modulate the tumor immune microenvironment, thereby activating systemic immunity. Therefore, for this purpose, it is important to design a multifunctional copper-based nanomaterial. Method: In this study, we developed Bi2O3-XSX-CuS p-n heterojunction nanoparticles (BCuS NPs) designed to stimulate systemic immune responses and effectively suppress both dormant and recurrent tumors. BCuS nanoparticles were characterized using transmission electron microscopy, X-ray diffraction, and other methods. In addition, the sonodynamic and chemodynamic properties of BCuS were intensively studied by various experimental methods. We identified the mechanisms by which BCuS induced multiple paths of cell death, by using in vitro experiments, including immunofluorescence assays, western blotting, and cell flow cytometry. In addition, we used mouse orthotopic and distal tumor models and RNA sequencing to evaluate the efficacy of combination therapy. Results: The results showed that BCuS produced a Fenton-like reaction in an acidic environment and induced the production of highly toxic ROS during ultrasound treatment. In vitro studies further showed that BCuS induced the occurrence of cuproptosis and ferroptosis, and stimulated ICD in combination with ROS, thereby effectively reversing the immunosuppression of the tumor microenvironment, and improving the sensitivity of immunotherapy. As demonstrated by in vitro studies, in vivo experiments also confirmed the enhanced effects of combination therapy. Conclusion: The BCuS sonosensitizer showed sonodynamic therapy effects, including inhibition of tumor growth in combination with multiple cell death modalities. These findings provide a novel method for using nanomaterials for multimodal combination cancer therapy.

AURKC Promotes Clear Cell Renal Cell Carcinoma Proliferation Through Upregulation of ERp57

In recent years, aurora kinase C (AURKC) has emerged as a potential therapeutic target for cancer, having been found to induce proliferation in a variety of cancers. However, at present, its precise mechanism remains unclear. In this study, the specific role of AURKC in renal clear cell carcinoma and its mechanism was investigated. The protein expression levels of AURKC were evaluated in clear cell carcinoma and adjacent normal tissues, followed by prognostic analysis. Subsequently, cell models with knocked-down and overexpressed AURKC were constructed for in vitro cell experiments, and tumor-bearing mouse models were constructed to confirm the specific role of AURKC in vivo. AURKC was found to be highly expressed in ccRCC, which was associated with poor prognosis. In the in vitro experiments, the expression levels of CyclinD1 and proliferating cell nuclear antigen (PCNA) proteins were downregulated after AURKC knockdown, and the cell proliferation ability was found to decrease significantly. After AURKC overexpression, the levels of ERp57 protein expression increased significantly, also significantly enhancing the cell proliferation ability. In addition, AURKC was found to interact with ERp57 and exhibited a colocalization relationship. In the in vivo experiments, AURKC downregulation significantly inhibited the expression of ERp57 protein and blocked the growth of tumor tissue in tumor-bearing mice. These results suggest that the abnormal expression of AURKC in ccRCC enhances the expression of ERp57 protein, thereby promoting the proliferation of clear cell renal cell carcinoma. Thus, AURKC shows potential as a target for the treatment of ccRCC.

A Review of the Bromodomain and Extraterminal Domain Epigenetic Reader Proteins: Function on Virus Infection and Cancer

The BET (bromodomain and extraterminal domain) family of proteins, particularly BRD4 (bromodomain-containing protein 4), plays a crucial role in transcription regulation and epigenetic mechanisms, impacting key cellular processes such as proliferation, differentiation, and the DNA damage response. BRD4, the most studied member of this family, binds to acetylated lysines on both histones and non-histone proteins, thereby regulating gene expression and influencing diverse cellular functions such as the cell cycle, tumorigenesis, and immune responses to viral infections. Given BRD4's involvement in these fundamental processes, it is implicated in various diseases, including cancer and inflammation, making it a promising target for therapeutic development. This review comprehensively explores the roles of the BET family in gene transcription, DNA damage response, and viral infection, discussing the potential of targeted small-molecule compounds and highlighting BET proteins as promising candidates for anticancer therapy.

Targeting the epigenetic reader "BET" as a therapeutic strategy for cancer

Bromodomain and extraterminal (BET) proteins have the ability to bind to acetylated lysine residues present in both histones and non-histone proteins. This binding is facilitated by the presence of tandem bromodomains. The regulatory role of BET proteins extends to chromatin dynamics, cellular processes, and disease progression. The BET family comprises of BRD 2, 3, 4 and BRDT. The BET proteins are a class of epigenetic readers that regulate the transcriptional activity of a multitude of genes that are involved in the pathogenesis of cancer. Thus, targeting BET proteins has been identified as a potentially efficacious approach for the treatment of cancer. BET inhibitors (BETis) are known to interfere with the binding of BET proteins to acetylated lysine residues of chromatin, thereby leading to the suppression of transcription of several genes, including oncogenic transcription factors. Here in this review, we focus on role of Bromodomain and extra C-terminal (BET) proteins in cancer progression. Furthermore, numerous small-molecule inhibitors with pan-BET activity have been documented, with certain compounds currently undergoing clinical assessment. However, it is apparent that the clinical effectiveness of the present BET inhibitors is restricted, prompting the exploration of novel technologies to enhance their clinical outcomes and mitigate undesired adverse effects. Thus, strategies like development of selective BET-BD1, & BD2 inhibitors, dual and acting BET are also presented in this review and attempts to cover the chemistry needed for proper establishment of designed molecules into BRD have been made. Moreover, the review attempts to summarize the details of research till date and proposes a space for future development of BET inhibitor with diminished side effects. It can be concluded that discovery of isoform selective BET inhibitors can be a way forward in order to develop BET inhibitors with negligible side effects.

BRD4: New Hope in the Battle Against Glioblastoma

The BET family proteins, comprising BRD2, BRD3 and BRD4, represent epigenetic readers of acetylated histone marks that play pleiotropic roles in the tumorigenesis and growth of multiple human malignancies, including glioblastoma (GBM). A growing body of investigation has proven BET proteins as valuable therapeutic targets for cancer treatment. Recently, several BRD4 inhibitors and degraders have been reported to successfully suppress GBM in preclinical and clinical studies. However, the precise role and mechanism of BRD4 in the pathogenesis of GBM have not been fully elucidated or summarized. This review focuses on summarizing the roles and mechanisms of BRD4 in the context of the initiation and development of GBM. In addition, several BRD4 inhibitors have been evaluated for therapeutic purposes as monotherapy or in combination with chemotherapy, radiotherapy, and immune therapies. Here, we provide a critical appraisal of studies evaluating various BRD4 inhibitors and degraders as novel treatment strategies against GBM.

Expression and purification of recombinant human CCL5 and its biological characterization

C-C motif chemokine ligand 5 (CCL5) is crucial in the tumor microenvironment. It has been previously reported to act as a key role in tumor invasion and metastasis. However, the function of exogenous CCL5 in ovarian cancer has not been well-characterized. The present study attempted to express and purify recombinant CCL5 protein and investigate the exogenous CCL5 in ovarian cancer cell proliferation. The human CCL5 was amplified and inserted into the pET-30a vectors for prokaryotic expression in Escherichia coli BL21. Soluble His-CCL5 was successfully expressed with 0.1 mmol/L of isopropyl-β-D-1-tiogalactopiranoside at 25 ℃ and purified by affinity chromatography. Additionally, methyl thiazolyl tetrazolium (MTT) assay demonstrated that CCL5 promotes ovarian cancer cell proliferation; increases the phosphorylation levels of extracellular-signal-regulated kinase and mitogen-activated protein kinase/ERK kinase, and increases the mRNA levels of Jun, NF-κB2, Nras, Relb, and Traf2. Furthermore, treatment with the MEK inhibitor reduced the Jun, NF-κB2, and Traf2 mRNA levels, indicating that exogenous CCL5 increased ovarian cancer cell proliferation, through MEK/ERK pathway activation, and Jun, NF-κB2, and Traf2 expression. The present study provided primary data for further studies to discover more CCL5 functions in ovarian cancer.

Exogenous interleukin-1 beta promotes the proliferation and migration of HeLa cells via the MEK/ERK signaling pathway

OBJECTIVE

Interleukin-1 beta (IL-1β) is a crucial cytokine that has been implicated in cancer and metastasis development. However, its possible mechanistic role in cervical cancer remains unclear. This study aimed to investigate the functions of exogenous IL-1β in cervical cancer cell proliferation and migration.

METHODS

HeLa cell proliferation and migration were measured using MTT and Transwell assays. A lentivirus-mediated packaging system was used to construct an IL-1β overexpressing cell line. MEK/ERK signal transduction was inhibited by pretreatment with the MEK inhibitor PD98059. qRT-PCR and Western blotting were used to test the expression of relevant genes.

RESULTS

Exogenous IL-1β promoted the proliferation and migration of HeLa cells. In addition, overexpression of IL-1β in HeLa cells promoted cell proliferation. Mechanistically, exogenous IL-1β increased the phosphorylated MEK and ERK levels in HeLa cells and the expression of JUN, RELB, and NF-κB2. Alternatively, blockade of MEK inhibited the promoting proliferation effects of IL-1β and the expression of JUN, RELB, and NF-κB2.

CONCLUSIONS

Our data suggest that exogenous IL-1β regulates HeLa cell functions by regulating the MEK/ERK signaling pathway and by targeting JUN, RELB, and NF-κB2. Our study uncovered a potential association across IL-1β, cervical tumor development, and cancer progression.

Establishment and validation of a novel invasion-related gene signature for predicting the prognosis of ovarian cancer

BACKGROUND

Ovarian cancer (OC) is an invasive gynaecologic cancer with a high cancer-related death rate. The purpose of this study was to establish an invasion-related multigene signature to predict the prognostic risk of OC.

METHODS

We extracted 97 invasion-related genes from The Cancer Genome Atlas (TCGA) database. Then, the ConsensusClusterPlus and limma packages were used to calculate differentially expressed genes (DEGs). To calculate the immune scores of the molecular subtypes, we used ESTIMATE to evaluate the stromal score, immune score and ESTIMATE score. MCP-counter and the GSVA package ssgsea were used to evaluate the types of infiltrating immune cells. Survival and nomogram analyses were performed to explore the prognostic value of the signature. Finally, qPCR, immunohistochemistry staining and functional assays were used to evaluate the expression and biological abilities of the signature genes in OC.

RESULTS

Based on the consistent clustering of invasion-related genes, cases in the OC datasets were divided into two subtypes. A significant difference was observed in prognosis between the two subtypes. Most genes were highly expressed in the C1 group. Based on the C1 group genes, we constructed an invasion-related 6-gene prognostic risk model. Furthermore, to verify the signature, we used the TCGA-test and GSE32062 and GSE17260 chip datasets for testing and finally obtained a good risk prediction effect in those datasets. Moreover, the results of the qPCR and immunohistochemistry staining assays revealed that KIF26B, VSIG4 and COL6A6 were upregulated and that FOXJ1, MXRA5 and CXCL9 were downregulated in OC tissues. The functional study showed that the expression of KIF26B, VSIG4, COL6A6, FOXJ1, MXRA5 and CXCL9 can regulate the migration and invasion abilities of OC cells.

CONCLUSION

We developed a 6-gene prognostic stratification system (FOXJ1, MXRA5, KIF26B, VSIG4, CXCL9 and COL6A6) that is independent of clinical features. These results suggest that the signature could potentially be used to evaluate the prognostic risk of OC patients.

CRISPR/Cas9: A Molecular Tool for Ovarian Cancer Management beyond Gene Editing

Ovarian cancer manifests with early metastases and has an adverse outcome, impacting the health of women globally. Currently, this malignancy is often treated with cytoreductive surgery and platinum-based chemotherapy. This treatment option has a limited success rate due to tumor recurrence and chemoresistance. Consequently, the fundamental objective of ovarian cancer treatment is the development of novel treatment approaches. As a new robust tool, the CRISPR/Cas9 gene-editing system has shown immense promise in elucidating the molecular basis of all the facets of ovarian cancer. Due to the precise gene editing capabilities of CRISPR-Cas9, researchers have been able to conduct a more comprehensive investigation of the genesis of ovarian cancer. This gained knowledge can be translated into the development of novel diagnostic approaches and newer therapeutic targets for this dreadful malignancy. There is encouraging preclinical evidence that suggests that CRISPR/Cas9 is a powerful versatile tool for selectively targeting cancer cells and inhibiting tumor growth, establishing new signaling pathways involved in carcinogenesis, and verifying biomolecules as druggable targets. In this review, we analyzed the current research and progress made using CRISPR/Cas9-based engineering strategies in the diagnosis and treatment, as well as the challenges in bringing this method to clinics. This comprehensive analysis will lay the basis for subsequent research in the future for the treatment of ovarian cancer.

Molecular Dynamic Simulations of Bromodomain and Extra-Terminal Protein 4 Bonded to Potent Inhibitors

Bromodomain and extra-terminal domain (BET) subfamily is the most studied subfamily of bromodomain-containing proteins (BCPs) family which can modulate acetylation signal transduction and produce diverse physiological functions. Thus, the BET family can be treated as an alternative strategy for targeting androgen-receptor (AR)-driven cancers. In order to explore the effect of inhibitors binding to BRD4 (the most studied member of BET family), four 150 ns molecular dynamic simulations were performed (free BRD4, Cpd4-BRD4, Cpd9-BRD4 and Cpd19-BRD4). Docking studies showed that Cpd9 and Cpd19 were located at the active pocket, as well as Cpd4. Molecular dynamics (MD) simulations indicated that only Cpd19 binding to BRD4 can induce residue Trp81-Ala89 partly become α-helix during MD simulations. MM-GBSA calculations suggested that Cpd19 had the best binding effect with BRD4 followed by Cpd4 and Cpd9. Computational alanine scanning results indicated that mutations in Phe83 made the greatest effects in Cpd9-BRD4 and Cpd19-BRD4 complexes, showing that Phe83 may play crucial roles in Cpd9 and Cpd19 binding to BRD4. Our results can provide some useful clues for further BCPs family search.

Role and Clinical Utility of Cancer/Testis Antigens in Head and Neck Squamous Cell Carcinoma

Cancer/testis (CT) antigens exhibit selective expression predominantly in immunoprivileged tissues in non-pathological contexts but are aberrantly expressed in diverse cancers. Due to their expression pattern, they have historically been attractive targets for immunotherapies. A growing number of studies implicate CT antigens in almost all hallmarks of cancer, suggesting that they may act as cancer drivers. CT antigens are expressed in head and neck squamous cell carcinomas. However, their role in the pathogenesis of these cancers remains poorly studied. Given that CT antigens hold intriguing potential as therapeutic targets and as biomarkers for prognosis and that they can provide novel insights into oncogenic mechanisms, their further study in the context of head and squamous cell carcinoma is warranted.

The Functions of BET Proteins in Gene Transcription of Biology and Diseases

The BET (bromodomain and extra-terminal domain) family proteins, consisting of BRD2, BRD3, BRD4, and testis-specific BRDT, are widely acknowledged as major transcriptional regulators in biology. They are characterized by two tandem bromodomains (BDs) that bind to lysine-acetylated histones and transcription factors, recruit transcription factors and coactivators to target gene sites, and activate RNA polymerase II machinery for transcriptional elongation. Pharmacological inhibition of BET proteins with BD inhibitors has been shown as a promising therapeutic strategy for the treatment of many human diseases including cancer and inflammatory disorders. The recent advances in bromodomain protein biology have further uncovered the complex and versatile functions of BET proteins in the regulation of gene expression in chromatin. In this review article, we highlight our current understanding of BET proteins' functions in mediating protein-protein interactions required for chromatin-templated gene transcription and splicing, chromatin remodeling, DNA replication, and DNA damage repair. We further discuss context-dependent activator vs. repressor functions of individual BET proteins, isoforms, and bromodomains that may be harnessed for future development of BET bromodomain inhibitors as emerging epigenetic therapies for cancer and inflammatory disorders.

Bromodomain protein BRDT directs ΔNp63 function and super-enhancer activity in a subset of esophageal squamous cell carcinomas

Esophageal squamous cell carcinoma (ESCC) is the predominant subtype of esophageal cancer with a particularly high prevalence in certain geographical regions and a poor prognosis with a 5-year survival rate of 15-25%. Despite numerous studies characterizing the genetic and transcriptomic landscape of ESCC, there are currently no effective targeted therapies. In this study, we used an unbiased screening approach to uncover novel molecular precision oncology targets for ESCC and identified the bromodomain and extraterminal (BET) family member bromodomain testis-specific protein (BRDT) to be uniquely expressed in a subgroup of ESCC. Experimental studies revealed that BRDT expression promotes migration but is dispensable for cell proliferation. Further mechanistic insight was gained through transcriptome analyses, which revealed that BRDT controls the expression of a subset of ΔNp63 target genes. Epigenome and genome-wide occupancy studies, combined with genome-wide chromatin interaction studies, revealed that BRDT colocalizes and interacts with ΔNp63 to drive a unique transcriptional program and modulate cell phenotype. Our data demonstrate that these genomic regions are enriched for super-enhancers that loop to critical ΔNp63 target genes related to the squamous phenotype such as KRT14, FAT2, and PTHLH. Interestingly, BET proteolysis-targeting chimera, MZ1, reversed the activation of these genes. Importantly, we observed a preferential degradation of BRDT by MZ1 compared with BRD2, BRD3, and BRD4. Taken together, these findings reveal a previously unknown function of BRDT in ESCC and provide a proof-of-concept that BRDT may represent a novel therapeutic target in cancer.