The multiple uses of azelaic acid in dermatology: mechanism of action, preparations, and potential therapeutic applications

Azelaic acid (AZA) is a naturally occurring saturated dicarboxylic acid whose topical application has found multiple uses in dermatology. Its anti-inflammatory, antioxidant and antimicrobial properties against Propionibacterium acne are currently used in the treatment of various types of acne such as rosacea and acne vulgaris. AZA is an inhibitor of tyrosinase, mitochondrial respiratory chain enzymes and DNA synthesis, and is a scavenger of harmful free radicals and inhibits the production of reactive oxygen species by neutrophils. Interestingly, AZA also has anti-proliferative and cytotoxic effects on various cancer cells. To date, its inhibitory effect on melanocytes has been mainly used, making it widely used in the treatment of hyperpigmentation disorders such as melasma and post-inflammatory hyperpigmentation. Commercially available topical formulations with cosmetic and drug status contain 5% to 20% AZA in the form of gels and creams. The use of liposomal technology allows greater control over the pharmacokinetics and pharmacodynamics of the formulations. When applied topically, AZA is well tolerated, and side effects are limited to generally mild and transient local skin irritation. Importantly, liposomal technology has enabled the drug to penetrate all layers of the skin while maintaining a very high accumulation of the active ingredient. This solution could be revolutionary for the treatment of skin cancer, where until now the main obstacle was poor absorption through the skin, making the treatment require multiple applications to maintain long-term activity levels. In this review, we will present the mechanism of action and pharmacokinetics of AZA. We will summarize its use in the treatment of dermatoses and its potential in skin cancer therapy. We will provide an overview of the preparations available on the market, taking into consideration technologies used.

TIM-3 as a promising target for cancer immunotherapy in a wide range of tumors

T-cell immunoglobulin and mucin domain-containing protein 3 (TIM-3) expression has been a trending topic in recent years due to its differential expression in a wide range of neoplasms. TIM-3 is one of the key immune checkpoint receptors that interact with GAL-9, PtdSer, HMGB1 and CEACAM1. Initially identified on the surface of T helper 1 (Th1) lymphocytes and later on cytotoxic lymphocytes (CTLs), monocytes, macrophages, natural killer cells (NKs), and dendritic cells (DCs), TIM-3 plays a key role in immunoregulation. Recently, a growing body of evidence has shown that its differential expression in various tumor types indicates a specific prognosis for cancer patients. Here, we discuss which types of cancer TIM-3 can serve as a prognostic factor and the influence of coexpressed immune checkpoint inhibitors, such as LAG-3, PD-1, and CTLA-4 on patients' outcomes. Currently, experimental medicine involving TIM-3 has significantly enhanced the anti-tumor effect and improved patient survival. In this work, we summarized clinical trials incorporating TIM-3 targeting monoclonal and bispecific antibodies in monotherapy and combination therapy and highlighted the emerging role of cell-based therapies.

LAG-3 as a Potent Target for Novel Anticancer Therapies of a Wide Range of Tumors

LAG-3 (Lymphocyte activation gene 3) protein is a checkpoint receptor that interacts with LSEC-tin, Galectin-3 and FGL1. This interaction leads to reduced production of IL-2 and IFN-γ. LAG-3 is widely expressed in different tumor types and modulates the tumor microenvironment through immunosuppressive effects. Differential expression in various tumor types influences patient prognosis, which is often associated with coexpression with immune checkpoint inhibitors, such as TIM-3, PD-1 and CTLA-4. Here, we discuss expression profiles in different tumor types. To date, many clinical trials have been conducted using LAG-3 inhibitors, which can be divided into anti-LAG-3 monoclonal antibodies, anti-LAG-3 bispecifics and soluble LAG-3-Ig fusion proteins. LAG-3 inhibitors supress T-cell proliferation and activation by disallowing for the interaction between LAG-3 to MHC-II. The process enhances anti-tumor immune response. In this paper, we will review the current state of knowledge on the structure, function and expression of LAG-3 in various types of cancer, as well as its correlation with overall prognosis, involvement in cell-based therapies and experimental medicine. We will consider the role of compounds targeting LAG-3 in clinical trials both as monotherapy and in combination, which will provide data relating to the efficacy and safety of proposed drug candidates.