High expression of tight junction protein 1 as a predictive biomarker for bladder cancer grade and staging

Novel chromium (III)-based compound for inhibition of oxaliplatin-resistant colorectal cancer progression

Colorectal cancer (CRC) ranks as the third leading cause of cancer-related mortality worldwide. The current standard of care includes systemic chemotherapy with cytotoxic agents, offering palliative relief for severe CRC cases and serving as the primary therapy for metastatic recurrence. However, the development of chemoresistance poses a substantial obstacle in the realm of chemotherapy. This study delved into the potential of a novel chromium (III)-based compound, hexaacetotetraaquadihydroxochromium (III) diiron (III) nitrate, for CRC treatment. The therapeutic promise of this innovative chromium (III)-based compound was explored by utilizing LoVo colon cancer cells and an in-vivo mouse model of CRC. Various dosages of the compound were administered to LoVo parental cells and LoVo oxaliplatin-resistant cells. Findings unveiled that a concentration of 2000 μg/mL of the chromium (III) compound significantly inhibited mesenchymal transition and the migratory and invasive properties of LoVo oxaliplatin-resistant cells. This novel chromium (III)-based compound also demonstrated similar efficacy in other different CRC cell lines. The tumor growth was in the in-vivo mouse model was reduced by this compound. Moreover, the chromium (III)-based compound induced apoptosis by triggering the endoplasmic reticulum (ER) stress pathway in LoVo oxaliplatin-resistant cells. This study illuminates the capacity of the novel chromium (III)-based compound to impede the progression and growth of chemotherapy-resistant CRC. This discovery instills confidence in the potential of this compound as a therapeutic agent for CRC, even in the face of drug resistance. It holds the promise of serving as a valuable asset in the future treatment of chemotherapy-resistant CRC.

Functional Analysis of Membrane-Associated Scaffolding Tight Junction (TJ) Proteins in Tumorigenic Characteristics of B16-F10 Mouse Melanoma Cells

Tight junction (TJ) proteins (Tjps), Tjp1 and Tjp2, are tight junction-associated scaffold proteins that bind to the transmembrane proteins of tight junctions and the underlying cytoskeleton. In this study, we first analyzed the tumorigenic characteristics of B16-F10 melanoma cells, including cell proliferation, migration, invasion, metastatic potential, and the expression patterns of related proteins, after the CRISPR-Cas9-mediated knockout (KO) of Tjp genes. The proliferation of Tjp1 and Tjp2 KO cells significantly increased in vitro. Other tumorigenic characteristics, including migration and invasion, were significantly enhanced in Tjp1 and Tjp2 KO cells. Zonula occludens (ZO)-associated protein Claudin-1 (CLDN-1), which is a major component of tight junctions and functions in controlling cell-to-cell adhesion, was decreased in Tjp KO cells. Additionally, Tjp KO significantly stimulated tumor growth and metastasis in an in vivo mouse model. We performed a transcriptome analysis using next-generation sequencing (NGS) to elucidate the key genes involved in the mechanisms of action of Tjp1 and Tjp2. Among the various genes affected by Tjp KO-, cell cycle-, cell migration-, angiogenesis-, and cell-cell adhesion-related genes were significantly altered. In particular, we found that the Ninjurin-1 (Ninj1) and Catenin alpha-1 (Ctnna1) genes, which are known to play fundamental roles in Tjps, were significantly downregulated in Tjp KO cells. In summary, tumorigenic characteristics, including cell proliferation, migration, invasion, tumor growth, and metastatic potential, were significantly increased in Tjp1 and Tjp2 KO cells, and the knockout of Tjp genes significantly affected the expression of related proteins.

Roles of non-coding RNAs in the metabolism and pathogenesis of bladder cancer

Bladder cancer (BC) is featured as the second most common malignancy of the urinary tract worldwide with few treatments leading to high incidence and mortality. It stayed a virtually intractable disease, and efforts to identify innovative and effective therapies are urgently needed. At present, more and more evidence shows the importance of non-coding RNA (ncRNA) for disease-related study, diagnosis, and treatment of diverse types of malignancies. Recent evidence suggests that dysregulated functions of ncRNAs are closely associated with the pathogenesis of numerous cancers including BC. The detailed mechanisms underlying the dysregulated role of ncRNAs in cancer progression are still not fully understood. This review mainly summarizes recent findings on regulatory mechanisms of the ncRNAs, long non-coding RNAs, microRNAs, and circular RNAs, in cancer progression or suppression and focuses on the predictive values of ncRNAs-related signatures in BC clinical outcomes. A deeper understanding of the ncRNA interactive network could be compelling framework for developing biomarker-guided clinical trials.

TJP1 promotes vascular mimicry in bladder cancer by facilitating VEGFA expression and transcriptional activity through TWIST1

Tight junction protein 1 (TJP1) is a recently identified prominent regulator of bladder cancer (BLCA) angiogenesis and tumorigenesis. Vascular mimicry (VM) is a newly described tumor feature and is correlated with an increased risk of tumor metastasis. However, the relationship between TJP1 expression and VM in bladder cancer remains elusive. In the present study, we report a novel function for TJP1 in accommodating VM to promote tumor progression. We found that the elevated TJP1 expression was positively related to VM in patients and xenograft tumor models in bladder cancer. Enforced expression of TJP1 increased VM of BLCA cells in vitro and in vivo by elevating Vascular endothelial growth factor A (VEGFA) levels. Furthermore, VM induced by TJP1 overexpression was significantly blocked by the VEGFA and VEGFR inhibitors (Bevacizumab and Sunitinib). Mechanistically, TJP1 promoted VEGFA transcriptional and protein level in a TWIST1-dependent manner. Taken together, our study reveals that TJP1-regulated VEGFA overexpression may indicate a potential therapeutic target for clinical intervention in the early tumor neovascularization of bladder cancer.

Epigenome-wide DNA methylation in leukocytes and toenail metals: The normative aging study

BACKGROUND

Environmental metal exposures have been associated with multiple deleterious health endpoints. DNA methylation (DNAm) may provide insight into the mechanisms underlying these relationships. Toenail metals are non-invasive biomarkers, reflecting a medium-term time exposure window.

OBJECTIVES

This study examined variation in leukocyte DNAm and toenail arsenic (As), cadmium (Cd), lead (Pb), manganese (Mn), and mercury (Hg) among elderly men in the Normative Aging Study, a longitudinal cohort.

METHODS

We repeatedly collected samples of blood and toenail clippings. We measured DNAm in leukocytes with the Illumina HumanMethylation450 K BeadChip. We first performed median regression to evaluate the effects of each individual toenail metal on DNAm at three levels: individual cytosine-phosphate-guanine (CpG) sites, regions, and pathways. Then, we applied a Bayesian kernel machine regression (BKMR) to assess the joint and individual effects of metal mixtures on DNAm. Significant CpGs were identified using a multiple testing correction based on the independent degrees of freedom approach for correlated outcomes. The approach considers the effective degrees of freedom in the DNAm data using the principal components that explain >95% variation of the data.

RESULTS

We included 564 subjects (754 visits) between 1999 and 2013. The numbers of significantly differentially methylated CpG sites, regions, and pathways varied by metals. For example, we found six significant pathways for As, three for Cd, and one for Mn. The As-associated pathways were associated with cancer (e.g., skin cancer) and cardiovascular disease, whereas the Cd-associated pathways were related to lung cancer. Metal mixtures were also associated with 47 significant CpG sites, as well as pathways, mainly related to cancer and cardiovascular disease.

CONCLUSIONS

This study provides an approach to understanding the potential epigenetic mechanisms underlying observed relations between toenail metals and adverse health endpoints.