Cathepsins B, D, and G Are Expressed in Metastatic Head and Neck Cutaneous Squamous Cell Carcinoma

Can alterations in cathepsin levels restrain the development of skin cancer?: A bidirectional multivariate Mendelian-randomization study

Malignant skin tumors mainly include basal cell carcinoma, squamous cell carcinoma, and malignant melanoma. There is currently observational research suggesting that changes in cathepsin (CTS) may be a factor in the development of malignant skin tumors, but no studies have yet demonstrated a causal relationship between tissue protease changes and the occurrence of malignant skin tumors. Current studies have shown that cathepsin is involved in tumor cell invasion and metastasis by regulating growth factors and cellular immune function in tumor microenvironment, decomposing extracellular matrix and basement membrane, and promoting angiogenesis. In this study, we conducted a bidirectional Mendelian-randomization study using publicly available genome-wide association study (GWAS; GWAS Catalog) data. This study applies a bidirectional multivariate Mendelian randomization (MR) approach to investigate the causal relationship between cathepsin, basal cell carcinoma, squamous cell carcinoma, and malignant melanoma. In cases where multiple cathepsins are implicated as etiological factors in certain diseases, a multivariable analysis is conducted to assess the direct and indirect causal effects of the exposure factors. In this study, we present a comprehensive MR analysis to investigate the relationship between 9 cathepsin and basal cell carcinoma, squamous cell carcinoma, and malignant melanoma. Based on our MR analysis using the largest GWAS Catalog dataset available, we are able to draw relatively reliable conclusions. In the MR study, we found that tissue protease L2 can promote skin cancer, Cathepsin O, and Cathepsin F are associated with an increased risk of basal cell carcinoma. Cathepsin H can inhibit basal cell carcinoma and malignant melanoma. In the reverse MR study, it was found that squamous cell carcinoma may cause an increase in Cathepsin O expression. In the multivariate analysis, it was found that Cathepsin H is a direct factor in reducing the occurrence of skin cancer and melanoma, with no apparent causal relationship to non-melanoma skin cancer. Cathepsin has a dual impact on skin cancer cells, and the expression of different cathepsins at the edge of skin tumors may indicate different developmental tendencies of skin cancer. Cathepsin may serve as effective biomarkers for predicting tumors.

Role of Cathepsin B Expression in Oral Squamous Cell Carcinoma: A Comprehensive Review

This comprehensive review delves into the intricate landscape of oral squamous cell carcinoma (OSCC) by examining the role of cathepsin B expression in its pathogenesis. OSCC, a prevalent and clinically significant oral malignancy, poses a considerable global health burden, necessitating a thorough exploration of its underlying molecular mechanisms. Cathepsin B, a lysosomal cysteine protease, emerges as a critical player in OSCC, influencing tumour initiation, invasion, and metastasis. The review begins with a brief overview of OSCC, emphasizing its epidemiological and clinical features, followed by exploring the significance of studying cathepsin B expression in this context. In the manuscript, the structure and function of cathepsin B are elucidated, providing a foundation for understanding its aberrant expression in OSCC. Clinical studies revealing correlations with tumour grade and stage, along with prognostic significance, are scrutinized, offering insights into the potential diagnostic and prognostic utility of cathepsin B. The biological functions of cathepsin B in OSCC, including its impact on tumour invasion and modulation of apoptosis, are comprehensively discussed. The Therapeutic Implications section explores targeting cathepsin B as a potential strategy, emphasizing the need for future research to overcome associated challenges. In the Conclusion section, the review synthesizes key findings, delineates implications for future research, and highlights the potential impact of cathepsin B on OSCC diagnosis and treatment, contributing to the ongoing efforts to advance our understanding of this complex malignancy, which is associated with a high mortality rate and improve clinical outcomes.

Cancer Metastasis and Treatment Resistance: Mechanistic Insights and Therapeutic Targeting of Cancer Stem Cells and the Tumor Microenvironment

Cancer metastasis and treatment resistance are the main causes of treatment failure and cancer-related deaths. Their underlying mechanisms remain to be fully elucidated and have been attributed to the presence of cancer stem cells (CSCs)-a small population of highly tumorigenic cancer cells with pluripotency and self-renewal properties, at the apex of a cellular hierarchy. CSCs drive metastasis and treatment resistance and are sustained by a dynamic tumor microenvironment (TME). Numerous pathways mediate communication between CSCs and/or the surrounding TME. These include a paracrine renin-angiotensin system and its convergent signaling pathways, the immune system, and other signaling pathways including the Notch, Wnt/β-catenin, and Sonic Hedgehog pathways. Appreciation of the mechanisms underlying metastasis and treatment resistance, and the pathways that regulate CSCs and the TME, is essential for developing a durable treatment for cancer. Pre-clinical and clinical studies exploring single-point modulation of the pathways regulating CSCs and the surrounding TME, have yielded partial and sometimes negative results. This may be explained by the presence of uninhibited alternative signaling pathways. An effective treatment of cancer may require a multi-target strategy with multi-step inhibition of signaling pathways that regulate CSCs and the TME, in lieu of the long-standing pursuit of a 'silver-bullet' single-target approach.

Beyond basic research: the contribution of cathepsin B to cancer development, diagnosis and therapy

INTRODUCTION

In view of other candidate proteins from the cathepsin family of proteases holding great potential in being targeted during cancer therapy, the importance of Cathepsin B (CtsB) stands out as being truly exceptional. Based on its contribution to oncogenesis, its intimate connection with regulating apoptosis and modulating extracellular and intracellular functions through its secretion or compartmentalized subcellular localization, collectively highlight its complex molecular involvement with a myriad of normal and pathological regulatory processes. Despite its complex functional nature, CtsB is emerging as one of the few cathepsin proteases that has been extensively researched to yield tangible outcomes for cancer therapy.

AREAS COVERED

In this article, we review the scientific literature that has justified or shaped the importance of CtsB expression in cancer progression, from the perspective of highlighting a paradigm that is rapidly changing from basic research toward a broader clinical and translational context.

EXPERT OPINION

In doing so, we detail its maturation as a diagnostic marker through describing the development of CtsB-specific Activity-Based Probes, the rapid evolution of these toward a new generation of Prodrugs, and the evaluation of these in model systems for their therapeutic potential as anti-cancer agents in the clinic.