Pathways of Tumor development and progression in Drug-induced Nonmelanoma Skin Cancer: a New Hope or the Next Great Confusion?

Abstract

The factors that lead to the clinical manifestation of the nonmelanocytic skin tumors are different. Ultraviolet radiation, infections with human papillomaviruses, and inherited or iatrogenic-induced immunosuppression (in cases of autoimmune diseases and organ transplant recipients) are considered to be some of the most important generators and/or costimulating factors supporting the appearance of "de-novo" mutations and obstruct, in one or another way, the cell cycle arrest, the programmed cell death (apoptosis), and the immunosurveillance. Preconditions are thus created for the initial persistence and subsequent proliferation of the malignant cell branch in the genome, with the simultaneous increase of the risk of nonmelanocytic skin tumor manifestation.A number of medical drugs that possess a currently well-known selective, targeting, and immunomodulating effect, like the TNF-alpha inhibitors for example, most probably possess an additional blocking action on the death receptors within the framework of the extrinsic apoptotic pathway. In this way, they seem to be one of the major factors for the clinical manifestation not only of nonmelanocytic skin but also of a number of other type of tumors with a dependency on the genetic predisposition of each separate patient.This article focuses the attention on the basic exogenic and endogenic factors that affect the regulatory processes of the cellular cycle, apoptosis, immunosurveillance, and the human inflammasome in patients with nonmelanocytic skin tumors. These processes are interwoven in a complex network and are controlled by (1) the genome regulator p53, (2) its interaction with the proapoptotic acting proteins Bak and Bax, (3) as well as the interaction with the key regulatory protein of the inflammasome-ASC/TMS1.As a process, the malignant transformation is exceptionally dynamic, plastic, and adaptive. The exterior "interferences", on the part of the clinician, in the form of a planned therapy should be targeted at the simultaneous impact on the various pathogenetic chains with the objective of bringing the tumor cells to their total collapse. This can be made possible only after the careful and simultaneous-or parallel-examination of a much greater number of markers that serve to characterize the process of the malignant transformation-a fact, which is currently being disregarded by many researchers.

Carcinoma Cuniculatum in Course of Etanercept: Blocking Autoimmunity but Propagation of Carcinogenesis?

“…There is an increased risk of melanoma and also non-melanoma skin cancer in patients treated with TNF-alpha inhibitors (3,11). The risk for nonmelanoma skin cancer is increased 2 to 3 fold by TNF-alpha inhibitors (11).…”

“…The mitochondrial or intrinsic and the death ligand mediated, extrinsic apoptotic pathway seems to be the most important pathways for the integrity of genome and the elimination of the neoplastic cells (3,13). Death receptors 4 and 5, known also as DR4 and DR5 are cell surface receptors that could be activated by their tumor necrosis factorrelated apoptosis-inducing ligand (TRAIL), that could trigger apoptosis in most cancer cells in BCC and SCC, but not in normal cells (14).…”

“…According to the most-modem understanding, from the point of view of etiopathogenetics the regulation ofthe inflammation and the carcinogenesis appear to be inextricably bound, very complicated and, at the same time, complex processes (3,5). Chronic inflammation is, on the one hand, capable of agitating the carcinogenesis and on the other, in some cases the inflammation itselfis desirable for the elimination of the residual and potentially dangerous pre-tumor or already dysplastic cells (3,5).…”

“…Chronic inflammation is, on the one hand, capable of agitating the carcinogenesis and on the other, in some cases the inflammation itselfis desirable for the elimination of the residual and potentially dangerous pre-tumor or already dysplastic cells (3,5).…”

“…Increased sensitivity to apoptosis and effective clearance of apoptotic bodies could prevent carcinogenesis (5). The ASC/TMS 1 adapter protein has an indirect pro-apoptotic effect via its interaction with p53 and BAX (3,5).…”