Expression of TRAP1 in gastric cancer tissue and its correlation with malignant biology

The development of cancers research based on mitochondrial heat shock protein 90

Mitochondrial heat shock protein 90 (mtHsp90), including Tumor necrosis factor receptor-associated protein 1 (TRAP1) and Hsp90 translocated from cytoplasm, modulating cellular metabolism and signaling pathways by altering the conformation, activity, and stability of numerous client proteins, and is highly expressed in tumors. mtHsp90 inhibition results in the destabilization and eventual degradation of its client proteins, leading to interference with various tumor-related pathways and efficient control of cancer cell development. Among these compounds, gamitrinib, a specific mtHsp90 inhibitor, has demonstrated its safety and efficacy in several preclinical investigations and is currently undergoing evaluation in clinical trials. This review aims to provide a comprehensive overview of the present knowledge pertaining to mtHsp90, encompassing its structure and function. Moreover, our main emphasis is on the development of mtHsp90 inhibitors for various cancer therapies, to present a thorough overview of the recent pre-clinical and clinical advancements in this field.

The Epithelial to Mesenchymal Transition in Colorectal Cancer Progression: The Emerging Role of Succinate Dehydrogenase Alterations and Succinate Accumulation

Colorectal cancer (CRC) stands as the third most significant contributor to cancer-related mortality worldwide. A major underlying reason is that the detection of CRC usually occurs at an advanced metastatic stage, rendering therapies ineffective. In the progression from the in situ neoplasia stage to the advanced metastatic stage, a critical molecular mechanism involved is the epithelial-to-mesenchymal transition (EMT). This intricate transformation consists of a series of molecular changes, ultimately leading the epithelial cell to relinquish its features and acquire mesenchymal and stem-like cell characteristics. The EMT regulation involves several factors, such as transcription factors, cytokines, micro RNAs and long noncoding RNAs. Nevertheless, recent studies have illuminated an emerging link between metabolic alterations and EMT in various types of cancers, including colorectal cancers. In this review, we delved into the pivotal role played by EMT during CRC progression, with a focus on highlighting the relationship between the alterations of the tricarboxylic acid cycle, specifically those involving the succinate dehydrogenase enzyme, and the activation of the EMT program. In fact, emerging evidence supports the idea that elucidating the metabolic modifications that can either induce or inhibit tumor progression could be of immense significance for shaping new therapeutic approaches and preventative measures. We conclude that an extensive effort must be directed towards research for the standardization of drugs that specifically target proteins such as SDH and SUCNR1, but also TRAP1, PDH, ERK1/2, STAT3 and the HIF1-α catabolism.

New insights into molecular chaperone TRAP1 as a feasible target for future cancer treatments

Tumor necrosis factor receptor-associated protein 1 (TRAP1), a molecular chaperone, is a major member of the mitochondrial heat shock protein 90 (Hsp90) family. Studies have shown that TRAP1 can prevent hypoxia-induced damage to cardiomyocytes, maintain cardiomyocytes viability and mitochondrial membrane potential, and protect cardiomyocytes. In addition, it can also protect astrocytes from ischemic damage in vitro. In recent years, there have been many new discoveries in tumors. The abnormal expression of TRAP1 is closely related to the occurrence and development of various tumors. TRAP1 protein seems to be a central regulatory protein, involved in the activation of various oncogenic proteins and signaling pathways, and has a balanced function at tumor transformation and the intersection of different metabolic processes. Targeting its chaperone activity and molecular interactions can destroy the metabolism and survival adaptability of tumor cells, paving the way for the development of highly selective mitochondrial anti-tumor drugs. Moreover, the combination of TRAP1 inhibition and current traditional cancer therapies has shown promising applications. These findings have important implications for the diagnosis and treatment of tumors. Therefore, we reviewed the recently identified functions of the molecular chaperone TRAP1 in cancer development and progression, as well as the discovery and recent advances in selective TRAP1 inhibitors as anticancer drug therapies, opening up new attractive prospects for exploring strategies for targeting TRAP1 as a tumor cell target.

Helicobacter pylori-downregulated tumor necrosis factor receptor-associated protein 1 mediates apoptosis of human gastric epithelial cells

Heat shock proteins (HSPs) are crucial proteins in maintaining the homeostasis of human gastric epithelial cells. Tumor necrosis factor receptor-associated protein 1 (TRAP1), a member of the HSP90 family, has been shown to be involved in various crucial physiological processes, particularly against apoptosis. However, the regulation and function of TRAP1 in Helicobacter pylori infection is still unknown. Here, we found that TRAP1 expression was downregulated on human gastric epithelial cells during H. pylori infection by real-time polymerase chain reaction (PCR) and western blot analysis. Through virulence factors mutant H. pylori strains infection and inhibitors screening, we found that H. pylori vacuolating cytotoxin A ( vacA), but not cytotoxin-associated gene A ( cagA) protein, induced human gastric epithelial cells to downregulate TRAP1 via P38MAPK pathway by real-time PCR and western blot analysis. Furthermore, downregulation of TRAP1 with lentivirus carrying TRAP1 short hairpin RNA constructs impairs mitochondrial function, and increases apoptosis of gastric epithelial cells. The results indicate that H. pylori vacA downregulated TRAP1 is involved in the regulation of gastric epithelial cell apoptosis.

Effects of purified Omphalia lapidescens protein on metastasis, cell cycle, apoptosis and the JAK-STAT signaling pathway in SGC-7901 human gastric cells

Gastric cancer is one of the most common cancers globally with high rates of morbidity and mortality. Purified Omphalia lapidescens protein (pPeOp) is a protein extracted from the sclerotium of Omphalia lapidescens. The present study aimed to investigate the effects of pPeOp on the viability, migration, cell cycle progression and apoptosis of SGC-7901 cells. The expression of numerous proteins, namely matrix metallopeptidase (MMP)2, MMP9, p53, caspase-3, B-cell lymphoma (Bcl)-2, cyclin A2, cyclin B1, cyclin D1, cyclin dependent kinase (CDK)1, CDK2 and CDK4, were investigated using western blot analysis and reverse transcription-quantitative polymerase chain reaction. The results of the present study demonstrated that treating SGC-7901 cells with pPeOp markedly suppressed their migration, induced their apoptosis and arrested their progression in S phase. pPeOp also downregulated the expression of migration-associated proteins (MMP2 and MMP9) and cyclin-associated proteins (cyclin A2, cyclin B1, cyclin D1, CDK1, CDK2 and CDK4) in a dose-dependent manner. Cells treated with pPeOp significantly upregulated caspase-3 and p53 and downregulated Bcl-2. Finally, the impact of pPeOp on three key nodes of the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway were investigated and it was revealed that expression levels of JAK1, JAK2 and STAT3 were significantly downregulated following treatment. Together, the results of the present study suggested that pPeOp suppresses metastasis, arrests cell cycle, induces apoptosis and inhibits the JAK-STAT signaling pathway in SGC-7901 cells. Therefore, pPeOp may serve as a novel therapeutic agent for patients with gastric cancer.

Succinate: An initiator in tumorigenesis and progression

As an intermediate metabolite of the tricarboxylic acid cycle in mitochondria, succinate is widely investigated for its role in metabolism. In recent years, an increasing number of studies have concentrated on the unanticipated role of succinate outside metabolism, acting as, for instance, an inflammatory signal or a carcinogenic initiator. Actually, succinate dehydrogenase gene mutations and abnormal succinate accumulation have been observed in a battery of hereditary and sporadic malignancies. In this review, we discuss the unexpected role of succinate and possible mechanisms that may contribute to its accumulation. Additionally, we describe how the high concentration of succinate in the tumor microenvironment acts as an active participant in tumorigenesis, rather than a passive bystander or innocent victim. Focusing on mechanism-based research, we summarize some targeted therapies which have been applied to the clinic or are currently under development. Furthermore, we posit that investigational drugs with different molecular targets may expand our horizon in anticancer therapy.