Inhibition of the bromodomain and extra-terminal family of epigenetic regulators as a promising therapeutic approach for gastric cancer

Wnt signaling in gastric cancer: current progress and future prospects

Levels of the Wnt pathway components are abnormally altered in gastric cancer cells, leading to malignant cell proliferation, invasion and metastasis, poor prognosis and chemoresistance. Therefore, it is important to understand the mechanism of Wnt signaling pathway in gastric cancer. We systematically reviewed the molecular mechanisms of the Wnt pathway in gastric cancer development; and summarize the progression and the challenges of research on molecular agents of the Wnt pathway.

Super-enhancers complexes zoom in transcription in cancer

Super-enhancers (SEs) consist of multiple typical enhancers enriched at high density with transcription factors, histone-modifying enzymes and cofactors. Oncogenic SEs promote tumorigenesis and malignancy by altering protein-coding gene expression and noncoding regulatory element function. Therefore, they play central roles in the treatment of cancer. Here, we review the structural characteristics, organization, identification, and functions of SEs and the underlying molecular mechanism by which SEs drive oncogenic transcription in tumor cells. We then summarize abnormal SE complexes, SE-driven coding genes, and noncoding RNAs involved in tumor development. In summary, we believe that SEs show great potential as biomarkers and therapeutic targets.

Inhibition of BRD4 enhanced the tumor suppression effect of dasatinib in gastric cancer

BRD4, a member of the bromodomain and extraterminal (BET) family, is elevated in multiple cancer tissues, including gastric cancer (GC). Targeted therapy with BRD4 may help improve the overall survival of patients with GC. Meanwhile, the approved multi-target kinase inhibitor, dasatinib, was recently reported to show varied tumor-suppressive effects in GC cells. This study investigated BRD4 expression in vivo and in vitro using immunohistochemistry and western blotting, respectively. We discussed the relationship between BRD4 expression and patient prognosis. Next, the antitumor efficacy of dasatinib was measured in BRD4-knockdown GC cells to determine the role of BRD4 blockage in dasatinib treatment. Finally, molibresib, a BET inhibitor, was used to measure the cooperative function of BRD4 inhibition and dasatinib treatment in three GC cell lines. Epithelial BRD4 expression was higher in tumoral and metastatic tissues and was strongly associated with unfavorable tumor, node, and metastasis stages and survival. BRD4 expression was heterogeneous in the three GC cell lines tested in vitro. In SGC7901, a BRD4-high GC cell line, knockdown of BRD4 using specific siRNAs suppressed cell growth individually and cooperatively with dasatinib. Moreover, molibresib and dasatinib showed a cooperative effect in suppressing the proliferation of BRD4-high GC cells. In conclusion, we confirmed that increased epithelial BRD4 expression is associated with poor disease stage and prognosis in GC and BRD4 blockage might be a valuable strategy to improve the sensitivity of dasatinib and other drugs in the chemotherapy of advanced GC.

Roles of Bromodomain Extra Terminal Proteins in Metabolic Signaling and Diseases

BET proteins, which recognize and bind to acetylated histones, play a key role in transcriptional regulation. The development of chemical BET inhibitors in 2010 greatly facilitated the study of these proteins. BETs play crucial roles in cancer, inflammation, heart failure, and fibrosis. In particular, BETs may be involved in regulating metabolic processes, such as adipogenesis and metaflammation, which are under tight transcriptional regulation. In addition, acetyl-CoA links energy metabolism with epigenetic modification through lysine acetylation, which creates docking sites for BET. Given this, it is possible that the ambient energy status may dictate metabolic gene transcription via a BET-dependent mechanism. Indeed, recent studies have reported that various BET proteins are involved in both metabolic signaling regulation and disease. Here, we discuss some of the most recent information on BET proteins and their regulation of the metabolism in both cellular and animal models. Further, we summarize data from some randomized clinical trials evaluating BET inhibitors for the treatment of metabolic diseases.