Cysteine cathepsins are lysosomal enzymes belonging to the papain family. Their expression is misregulated in a wide variety of tumors, and ample data prove their involvement in cancer progression, angiogenesis, metastasis, and in the occurrence of drug resistance. However, while their overexpression is usually associated with highly aggressive tumor phenotypes, their mechanistic role in cancer progression is still to be determined to develop new therapeutic strategies. In this review, we highlight the literature related to the role of the cysteine cathepsins in cancer biology, with particular emphasis on their input into tumor biology.
Renal cell carcinoma (RCC) ranks the first death rate among the urogenital tumors, whereas its incidence follows the incidences of prostate and bladder cancer. The diagnosis of RCC at early stages allows immediately undertaking appropriate treatment, which significantly increases patients’ survival rate. Early and accurate diagnosis avoids inadequate treatment, provides the disease progression forecast, and permits to apply more efficient therapy. Unfortunately, the small renal tumors are usually asymptomatic resulting in the late diagnosis and, therefore, low efficacy of treatment. Thus, sensible and preventive biomarkers are essential for early RCC detection and monitoring of its progression. So far, many attempts were performed aimed at recognizing novel informative kidney tumor biomarkers applicable for early detection of the disease and possessing prognostic and predictive capabilities. This review summarizes recent advances in renal tumor biomarkers recognition, their diagnostic and prognostic values, and clinical feasibility.