Over-expression of Bcl2-associated athanogene 2 in oral cancer promotes cellular proliferation and is associated with poor prognosis

Comparative analysis of BAG1 and BAG2: Insights into their structures, functions and implications in disease pathogenesis

As BAG family members, Bcl-2 associated athanogene family protein 1 (BAG1) and 2 (BAG2) are implicated in multiple cellular processes, including apoptosis, autophagy, protein folding and homeostasis. Although structurally similar, they considerably differ in many ways. Unlike BAG2, BAG1 has four isoforms (BAG1L, BAG1M, BAG1S and BAG1 p29) displaying different expression features and functional patterns. BAG1 and BAG2 play different cellular functions by interacting with different molecules to participate in the regulation of various diseases, including cancer/tumor and neurodegenerative diseases. Commonly, BAG1 acts as a protective factor to predict a good prognosis of patients with some types of cancer or a risk factor in some other cancers, while BAG2 is regarded as a risk factor to promote cancer/tumor progression. In neurodegenerative diseases, BAG2 commonly acts as a neuroprotective factor. In this review, we summarized the differences in molacular structure and biological function between BAG1 and BAG2, as well as the influences of them on pathogenesis of diseases, and explore the prospects for their clinical therapy application by specifying the activators and inhibitors of BAG1 and BAG2, which might provide a better understanding of the underlying pathogenesis and developing the targeted therapy strategies for diseases.

Bag2 protects against doxorubicin-induced cardiotoxicity by maintaining Pink1-mediated mitophagy

The clinical application of Doxorubicin (DOX) is limited due to its cardiotoxicity. Mitophagy dysfunction is the primary cause of DOX-induced cardiotoxicity (DIC). However, the precise mechanism by which DOX regulates mitophagy remains elusive. Bag2 (BCL2-associated athanogene 2) is a cochaperone implicated in multiple pathological states. The aim of this study was to investigate the potential cardio-protective effects of Bag2 in DIC. C57BL/6 mice and AC16 cells were used to establish DIC model. The expression of Bag2 were measured by western blotting and immunohistochemical. The effects of Bag2 on DIC were assessed through functional gain and loss experiments. Through in vitro and in vivo experiments, we found that Bag2 expression was significantly reduced after DOX treatment. Both Bag2 knockdown and DOX administration resulted in apoptosis, mitochondrial dysfunction, and impaired mitophagy. Conversely, Bag2 overexpression exerted protective effects against these phenotypes induced by DOX stimulation. Mechanistically, Bag2 maintained mitophagy activation by binding to Pink1 and protecting it from proteasome-dependent degradation, thereby preserving mitochondrial function and protecting against myocardial lesions. Our findings suggest that Bag2 may serve as a promising therapeutic target for the treatment of DIC.

GNB1 promotes hepatocellular carcinoma progression by targeting BAG2 to activate P38/MAPK signaling

G-proteins are intracellular partners of G-protein-coupled receptors. As a member of the G-protein family, GNB1 has been shown to play a pro-cancer role in lung cancer and breast cancer. However, the biological function and detailed mechanisms of GNB1 in hepatocellular carcinoma progression are unclear. In this study, we investigated the effects of GNB1 and its possible mechanism of action in hepatocellular carcinoma (HCC). The clinical significance of GNB1 was evaluated in a large cohort of HCC patients, showing that GNB1 was overexpressed in HCC compared to adjacent normal liver tissues, and increased GNB1 expression was associated with poor prognosis. We also demonstrated that GNB1 enhances cell proliferation, colony formation, and cell migration and invasion in vitro and promotes the epithelial-to-mesenchymal transition process in HCC cells. Tumor xenograft model assay confirmed the oncogenic role of GNB1 in tumorigenicity in nude mice. Activation of P38 signaling was found in the GNB1 overexpressed HCC cells. Further intervention of P38 confirmed it as an important signaling pathway for the oncogenic role of GNB1 in HCC. Moreover, co-immunoprecipitation followed by liquid chromatograph-mass spectrometry identified that GNB1 exerted oncogenic functions via the interaction of BAG2 and activated P38 signaling pathway. Together, our results reveal that GNB1 plays a pivotal oncogenic role in HCC by promoting the P38 pathway via cooperating with BAG2. GNB1 may serve as a prognostic biomarker for patients with HCC.

Approaches for Head and Neck Cancer Research - Current Status and the Way Forward

Head and neck cancers (HNCs) are seeing an increasing trend in their prevalence among both genders and are the seventh most common cancer type occurring at the global level. Studies addressing both the cancer cell physiology and individual differences in response to a specific treatment modality should be understood for arriving at effective treatment and management of the HNCs. In this article, we discuss the trends in HNC research and their various approaches starting from 2D in vitro models, which are the traditional experimental materials to recently established Cancer-Tissue Originated Spheroids (CTOS) distinctly contributing towards personalized or precision medicine.

Proteomic Signatures of Diffuse and Intestinal Subtypes of Gastric Cancer

Gastric cancer is a leading cause of death from cancer globally. Gastric cancer is classified into intestinal, diffuse and indeterminate subtypes based on histology according to the Laurén classification. The intestinal and diffuse subtypes, although different in histology, demographics and outcomes, are still treated in the same fashion. This study was designed to discover proteomic signatures of diffuse and intestinal subtypes. Mass spectrometry-based proteomics using tandem mass tags (TMT)-based multiplexed analysis was used to identify proteins in tumor tissues from patients with diffuse or intestinal gastric cancer with adjacent normal tissue control. A total of 7448 or 4846 proteins were identified from intestinal or diffuse subtype, respectively. This quantitative mass spectrometric analysis defined a proteomic signature of differential expression across the two subtypes, which included gremlin1 (GREM1), bcl-2-associated athanogene 2 (BAG2), olfactomedin 4 (OLFM4), thyroid hormone receptor interacting protein 6 (TRIP6) and melanoma-associated antigen 9 (MAGE-A9) proteins. Although GREM1, BAG2, OLFM4, TRIP6 and MAGE-A9 have all been previously implicated in tumor progression and metastasis, they have not been linked to intestinal or diffuse subtypes of gastric cancer. Using immunohistochemical labelling of a tissue microarray comprising of 124 cases of gastric cancer, we validated the proteomic signature obtained by mass spectrometry in the discovery cohort. Our findings should help investigate the pathogenesis of these gastric cancer subtypes and potentially lead to strategies for early diagnosis and treatment.

With or without You: Co-Chaperones Mediate Health and Disease by Modifying Chaperone Function and Protein Triage

Heat shock proteins (HSPs) are a family of molecular chaperones that regulate essential protein refolding and triage decisions to maintain protein homeostasis. Numerous co-chaperone proteins directly interact and modify the function of HSPs, and these interactions impact the outcome of protein triage, impacting everything from structural proteins to cell signaling mediators. The chaperone/co-chaperone machinery protects against various stressors to ensure cellular function in the face of stress. However, coding mutations, expression changes, and post-translational modifications of the chaperone/co-chaperone machinery can alter the cellular stress response. Importantly, these dysfunctions appear to contribute to numerous human diseases. Therapeutic targeting of chaperones is an attractive but challenging approach due to the vast functions of HSPs, likely contributing to the off-target effects of these therapies. Current efforts focus on targeting co-chaperones to develop precise treatments for numerous diseases caused by defects in protein quality control. This review focuses on the recent developments regarding selected HSP70/HSP90 co-chaperones, with a concentration on cardioprotection, neuroprotection, cancer, and autoimmune diseases. We also discuss therapeutic approaches that highlight both the utility and challenges of targeting co-chaperones.

Overexpression of DOCK6 in oral squamous cell cancer promotes cellular migration and invasion and is associated with poor prognosis

OBJECTIVE

We aimed to identify the role of DOCK6 in oral squamous cell cancer (OSCC) in this study.

DESIGN

DOCK6 expression in OSCC was analyzed using TCGA and GEO datasets and was verified by quantitative real-time PCR, Western blotting, and immunohistochemistry. Statistical analyses were performed to evaluate the relationships between DOCK6 expression and the clinicopathological characteristics of OSCC patients. Wound healing and Transwell assays were performed to assess OSCC cell migration and invasion, respectively. STRING and GO analyses and gene set enrichment analysis were used to identify DOCK6-interacting proteins, their functions and their potential pathways.

RESULTS

DOCK6 was significantly upregulated at both the mRNA and protein levels in OSCC tissues (all P < 0.05). DOCK6 levels were positively correlated with age (P < 0.05), lymph node metastasis status (P < 0.001), clinical stage (P < 0.001), differentiation (P < 0.05), and poor clinical outcome (P < 0.05) in OSCC patients. Furthermore, univariate and multivariate analyses revealed that high DOCK6 expression (P < 0.01) and clinical stage III-IV (P < 0.05) might serve as independent prognostic factors for OSCC patients. Functionally, DOCK6 silencing significantly suppressed OSCC cell migration and invasion (all P < 0.05). Ten proteins that interact with DOCK6, more than ten functions related to cancer, and more than six pathways related to DOCK6 in OSCC were identified via bioinformatic methods.

CONCLUSION

DOCK6 is upregulated in OSCC, is associated with a poor prognosis in OSCC patients and increases OSCC cells migration and invasion. These findings suggest that DOCK6 may be a potential therapeutic target with prognostic implication in patients with OSCC.

Bcl-2 Associated Athanogene 2 (BAG2) is Associated With Progression and Prognosis of Hepatocellular Carcinoma: A Bioinformatics-Based Analysis

Background: Bcl-2 associated athanogene2 (BAG2) is reported to act as an oncogene or a tumor-suppressor in tumors in a context-dependent way; however, its function in hepatocellular carcinoma (HCC) remains unclear.

Methods: Immunohistochemistry (IHC) staining, cell counting kit-8 (CCK-8) assay, apoptotic assay, cell invasion assay and a set of bioinformatics tools were integrated to analyze the role of BAG2 in hepatocellular carcinoma.

Results: BAG2 was significantly up-regulated in HCC. Prognostic analysis indicated that HCC patients with high expression of BAG2 had significantly shorter overall survival, progression free survival and disease specific survival. Besides, silencing BAG2 in HCC cells impaired cell proliferation, facilitated apoptosis and repressed invasion of the cells. Bioinformatics analysis showed that BAG2 might regulate ribosome biogenesis in HCC.

Conclusion: This study revealed that the up-regulated BAG2 in HCC was associated with a worse prognosis and might favor the progression of the disease.

Identification of Overexpressed Genes in Malignant Pleural Mesothelioma

Malignant pleural mesothelioma (MPM) is a fatal tumor lacking effective therapies. The characterization of overexpressed genes could constitute a strategy for identifying drivers of tumor progression as targets for novel therapies. Thus, we performed an integrated gene-expression analysis on RNAseq data of 85 MPM patients from TCGA dataset and reference samples from the GEO. The gene list was further refined by using published studies, a functional enrichment analysis, and the correlation between expression and patients' overall survival. Three molecular signatures defined by 15 genes were detected. Seven genes were involved in cell adhesion and extracellular matrix organization, with the others in control of the mitotic cell division or apoptosis inhibition. Using Western blot analyses, we found that ADAMTS1, PODXL, CIT, KIF23, MAD2L1, TNNT1, and TRAF2 were overexpressed in a limited number of cell lines. On the other hand, interestingly, CTHRC1, E-selectin, SPARC, UHRF1, PRSS23, BAG2, and MDK were abundantly expressed in over 50% of the six MPM cell lines analyzed. Thus, these proteins are candidates as drivers for sustaining the tumorigenic process. More studies with small-molecule inhibitors or silencing RNAs are fully justified and need to be undertaken to better evaluate the cancer-driving role of the targets herewith identified.

Monocyte Chemoattractant Protein 1 Promotes VEGF-A Expression in OSCC by Activating ILK and MEK1/2 Signaling and Downregulating miR-29c

Oral squamous cell carcinoma (OSCC) is an aggressive tumor that has a poor prognosis, with high levels of local invasion and lymph node metastasis. Vascular endothelial growth factor A (VEGF-A) plays essential roles in OSCC tumor angiogenesis and metastasis. Monocyte chemoattractant protein-1 (MCP-1, CCL2) is implicated in various inflammatory conditions and pathological processes, including oral cancer. The existing evidence has failed to confirm any correlation between MCP-1 or VEGF-A expression and OSCC angiogenesis. In this study, high expression levels of MCP-1 and VEGF-A were positively correlated with disease stage in patients with OSCC. In oral cancer cells, MCP-1 increased VEGF-A expression and subsequently promoted angiogenesis; miR-29c mimic reversed MCP-1 activity. We also found that MCP-1 modulated VEGF-A expression and angiogenesis through CCR2/ILK/MEK1/2 signaling. Ex vivo results of the chick embryo chorioallantoic membrane (CAM) assay revealed the angiogenic qualities of MCP-1, with increased numbers of visible blood vessel branches. Our data suggest that MCP-1 is a new molecular therapeutic target for the inhibition of angiogenesis and metastasis in OSCC.