Tetraspanin 5 (TSPAN5), a Novel Gatekeeper of the Tumor Suppressor DLC1 and Myocardin-Related Transcription Factors (MRTFs), Controls HCC Growth and Senescence

NLRP3 inflammasome activation and altered mitophagy are key pathways in inclusion body myositis

Background

Inclusion body myositis (IBM) is the most prevalent muscle disease in adults for which no current treatment exists. The pathogenesis of IBM remains poorly defined. Inflammation and mitochondrial dysfunction are the most common histopathological findings. In this study, we aimed to explore the interplay between inflammation and mitochondrial dysfunction in IBM patients, highlighting sex differences.

Methods

We included 38 IBM patients and 22 age- and sex-matched controls without myopathy. Bulk RNA sequencing, Meso Scale Discovery ELISA, western blotting, histochemistry and immunohistochemistry were performed on frozen muscle samples from the study participants.

Results

We demonstrated activation of the NLRP3 inflammasome in IBM muscle samples, with the NLRP3 inflammasome pathway being the most upregulated. On muscle histopathology, there is increased NRLP3 immunoreactivity in both inflammatory cells and muscle fibers. Mitophagy is critical for removing damaged mitochondria and preventing the formation of a vicious cycle of mitochondrial dysfunction-NLRP3 activation. In the IBM muscle samples, we showed altered mitophagy, most significantly in males, with elevated levels of p-S65-Ubiquitin, a mitophagy marker. Furthermore, p-S65-Ubiquitin aggregates accumulated in muscle fibers that were mostly type 2 and devoid of cytochrome-c-oxidase reactivity. Type 2 muscle fibers are known to be more prone to mitochondrial dysfunction. NLRP3 RNA levels correlated with p-S65-Ubiquitin levels in both sexes but with loss of in muscle strength only in males. Finally, we identified sex-specific molecular pathways in IBM, with females having activation of pathways that could offset some of the pathomechanisms of IBM.

Conclusions

NLRP3 inflammasome is activated in IBM, along with altered mitophagy particularly in males, which is of potential therapeutic significance. These findings suggest sex-specific mechanisms in IBM that warrant further investigation.

The Molecular Mechanisms Underlying Onset and Progression of Liver Cancers

Liver cancers, including hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), are deadly cancers that have risen in frequency globally and have limited curative therapeutic options [...].

High Expression of Tetraspanin 5 as a Prognostic Marker of Colorectal Cancer

Cancer is a major disease and the leading cause of death worldwide, with colorectal cancer (CRC) being the third-most common cancer in Korea. The survival rate associated with CRC reduces as the disease stage increases. Therefore, its early detection and treatment can greatly increase patient survival rates. In this study, we identified the tetraspanin 5 (TSPAN5) gene as an important biomarker for predicting the prognosis of patients with CRC. A TMA slide was used for statistical analysis. pN and clinical stage were found to be significant factors according to chi-square analysis, whereas pT, pN, metastasis, clinical stage, and TSPAN5 expression were significant according to Cox regression analysis. In order to prove the usefulness of TSPAN5, which is overexpressed in patients with metastatic CRC, as a biomarker, proliferation, migration, invasion, and tumorigenicity were examined using cell lines inhibited using small interfering RNA. The evaluations confirmed that TSPAN5 suppression, in turn, suppressed proliferation, migration, invasion, and tumorigenesis, which are characteristic of cancer cells. Therefore, the evaluation of TSPAN5 expression may help observe the prognosis of CRC and determine an appropriate treatment method for patients with CRC.

Resveratrol induces DNA damage-mediated cancer cell senescence through the DLC1-DYRK1A-EGFR axis

Inducing cell senescence is widely regarded as a potent tumor suppression mechanism. Resveratrol has attracted increasing attention for its capacity to prevent and suppress cancer. However, the mechanism of resveratrol on the induction of cancer cell senescence has not been well clarified. Our results showed that resveratrol inhibited cell viability and colony formation and promoted cell senescence along with augmentation of SA-β-gal activity and modulation of senescence-associated molecular markers p53, p21 and LaminB protein in breast and liver cancer cells. The underlying mechanism was that resveratrol increased ROS generation to enhance tumor suppressor gene DLC1 expression, and DLC1 further inhibited the DYRK1A-EGFR axis to trigger DNA damage accompanied by up-regulation of the DNA double strand break marker protein γH2AX and down-regulation of the DNA repair related proteins p-BRCA1 and RAD51, eventually leading to cancer cell senescence. Resveratrol also effectively inhibited the volume of transplanted tumor with increased SA-β-gal activity and DLC1 level in a chicken embryo allantoic membrane xenograft tumor model. This is the first report to investigate whether resveratrol induces DNA damage-mediated cancer cell senescence through the DLC1-DYRK1A-EGFR axis, which could provide a solid base for resveratrol's application in cancer prevention and clinical treatment as a food additive or adjuvant therapies.

LPA receptor 1 (LPAR1) is a novel interaction partner of Filamin A that promotes Filamin A phosphorylation, MRTF-A transcriptional activity and oncogene-induced senescence

Myocardin-related transcription factors A and B (MRTFs) are coactivators of Serum Response Factor (SRF), which controls fundamental biological processes such as cell growth, migration, and differentiation. MRTF and SRF transcriptional activity play an important role in hepatocellular carcinoma (HCC) growth, which represents the second leading cause of cancer-related mortality in humans worldwide. We, therefore, searched for druggable targets in HCC that regulate MRTF/SRF transcriptional activity and can be exploited therapeutically for HCC therapy. We identified the G protein-coupled lysophosphatidic acid receptor 1 (LPAR1) as a novel interaction partner of MRTF-A and Filamin A (FLNA) using fluorescence resonance energy transfer-(FRET) and proximity ligation assay (PLA) in vitro in HCC cells and in vivo in organoids. We found that LPAR1 promotes FLNA phosphorylation at S2152 which enhances the complex formation of FLNA and MRTF-A, actin polymerization, and MRTF transcriptional activity. Pharmacological blockade or depletion of LPAR1 prevents FLNA phosphorylation and complex formation with MRTF-A, resulting in reduced MRTF/SRF target gene expression and oncogene-induced senescence. Thus, inhibition of the LPAR1-FLNA-MRTF-A interaction represents a promising strategy for HCC therapy.

Detection of Cellular Senescence in Human Primary Melanocytes and Malignant Melanoma Cells In Vitro

Detection and quantification of senescent cells remain difficult due to variable phenotypes and the absence of highly specific and reliable biomarkers. It is therefore widely accepted to use a combination of multiple markers and cellular characteristics to define senescent cells in vitro. The exact choice of these markers is a subject of ongoing discussion and usually depends on objective reasons such as cell type and treatment conditions, as well as subjective considerations including feasibility and personal experience. This study aims to provide a comprehensive comparison of biomarkers and cellular characteristics used to detect senescence in melanocytic systems. Each marker was assessed in primary human melanocytes that overexpress mutant BRAFV600E, as it is commonly found in melanocytic nevi, and melanoma cells after treatment with the chemotherapeutic agent etoposide. The combined use of these two experimental settings is thought to allow profound conclusions on the choice of senescence biomarkers when working with melanocytic systems. Further, this study supports the development of standardized senescence detection and quantification by providing a comparative analysis that might also be helpful for other cell types and experimental conditions.

Placental-Cadherin, a biomarker for local immune status and poor prognosis among patients with tongue squamous cell carcinoma

BACKGROUND

The prognostic and clinicopathological value of placental-Cadherin (CDH3) in multiple cancers is controversial. The diagnostic significance and functional mechanism of CDH3 in tongue squamous cell carcinoma (TSCC) have not been thoroughly investigated. This study aims to clarify the potential of CDH3 as biomarker for TSCC.

METHODS

Here, meta-analysis, bioinformatics, along wet-lab techniques were employed to evaluate the diagnostic, as well as the prognostic value of CDH3 in diverse types of cancers, especially TSCC. Meta-analysis was used to determine the influence of CDH3 on prognostic and clinicopathological features in numerous cancers. Molecular biology function was used to investigate the role of CDH3 in TSCC cells. The relationship of CDH3 with tumor-infiltrating immune cells (TIICs) in TSCC was assessed using CIBERSORT. Moreover, gene set enrichment analysis (GSEA) was done based on TCGA. Besides, the hub genes and associated cascades were uncovered based on gene co-expression with CDH3.

RESULTS

CDH3 upregulation correlated with worse overall survival and disease-free survival in various cancers. CDH3 was validated as an independent risk factor for HNSC and was linked to the onset of tumors, tumor stage, and infiltration depth. CDH3 silencing inhibited cell growth and induced apoptosis of the CAL-27 cell line. CDH3 expression level correlated with infiltration by macrophages, T cells, T cell regulatory cells (Tregs), and plasma cells in TSCC. GSEA revealed that CDH3 influences multiple cancer-associated cascades. Besides, CBX3, CCHCR1, along NFYC were identified as the core hub genes for CDH3.

CONCLUSION

We identified CDH3 as a pan-cancer gene with potential prognostic and diagnostic significance in various cancers, particularly in TSCC, where it is tumorigenic.