Histone deacetylase inhibitor (HDACi) upregulates activin A and activates the Smad signaling pathway in melanomas

Histone Deacetylase (HDAC) Inhibitors: A Promising Weapon to Tackle Therapy Resistance in Melanoma

Melanoma is an aggressive malignant tumor, arising more commonly on the skin, while it can also occur on mucosal surfaces and the uveal tract of the eye. In the context of the unresectable and metastatic cases that account for the vast majority of melanoma-related deaths, the currently available therapeutic options are of limited value. The exponentially increasing knowledge in the field of molecular biology has identified epigenetic reprogramming and more specifically histone deacetylation (HDAC), as a crucial regulator of melanoma progression and as a key driver in the emergence of drug resistance. A variety of HDAC inhibitors (HDACi) have been developed and evaluated in multiple solid and hematologic malignancies, showing promising results. In melanoma, various experimental models have elucidated a critical role of histone deacetylases in disease pathogenesis. They could, therefore, represent a promising novel therapeutic approach for advanced disease. A number of clinical trials assessing the efficacy of HDACi have already been completed, while a few more are in progress. Despite some early promising signs, a lot of work is required in the field of clinical studies, and larger patient cohorts are needed in order for more valid conclusions to be extracted, regarding the potential of HDACi as mainstream treatment options for melanoma.

New developments in investigational HDAC inhibitors for the potential multimodal treatment of cachexia

INTRODUCTION

Cachexia is a frequent feature of chronic diseases. This syndrome includes loss of body weight, depletion of skeletal muscle mass and altered metabolic homeostasis. Acceleration of protein and energy metabolism, impaired myogenesis, and systemic inflammation contribute to cachexia. Its occurrence impinges on treatment tolerance and on the quality of life of the patient, however, no effective therapy is available yet.

AREAS COVERED

This review focuses on the use of histone deacetylase inhibitors as pharmacological tools to prevent or delay cachexia, with reference to muscle wasting.

EXPERT OPINION

Novel histone deacetylase inhibitors could be considered as exercise mimetics and this supports their use as a treatment for muscle-wasting associated diseases, such as cachexia. The ability of some of these inhibitors to modulate the release of extracellular vesicles from tumor cells is a potential tool for restricting the development of cancer-induced muscle protein depletion. There are few clinical trials that are testing histone deacetylase inhibitors as a treatment for cachexia; this reflects the lack of robust experimental evidence of effectiveness. The determination of the pathogenic mechanisms of muscle wasting and the identification of suitable histone deacetylase inhibitors that target such mechanisms are necessary.