An evaluation of encorafenib for the treatment of melanoma

A Narrative Review of Current Knowledge on Cutaneous Melanoma

Cutaneous melanoma is a public health problem. Efforts to reduce its incidence have failed, as it continues to increase. In recent years, many risk factors have been identified. Numerous diagnostic systems exist that greatly assist in early clinical diagnosis. The histopathological aspect illustrates the grim nature of these cancers. Currently, pathogenic pathways and the tumor microclimate are key to the development of therapeutic methods. Revolutionary therapies like targeted therapy and immune checkpoint inhibitors are starting to replace traditional therapeutic methods. Targeted therapy aims at a specific molecule in the pathogenic chain to block it, stopping cell growth and dissemination. The main function of immune checkpoint inhibitors is to boost cellular immunity in order to combat cancer cells. Unfortunately, these therapies have different rates of effectiveness and side effects, and cannot be applied to all patients. These shortcomings are the basis of increased incidence and mortality rates. This study covers all stages of the evolutionary sequence of melanoma. With all these data in front of us, we see the need for new research efforts directed at therapies that will bring greater benefits in terms of patient survival and prognosis, with fewer adverse effects.

In Vitro Antiproliferative Effect of Cannabis Extract PHEC-66 on Melanoma Cell Lines

Melanoma, an aggressive form of skin cancer, can be fatal if not diagnosed and treated early. Melanoma is widely recognized to resist advanced cancer treatments, including immune checkpoint inhibitors, kinase inhibitors, and chemotherapy. Numerous studies have shown that various Cannabis sativa extracts exhibit potential anticancer effects against different types of tumours both in vitro and in vivo. This study is the first to report that PHEC-66, a Cannabis sativa extract, displays antiproliferative effects against MM418-C1, MM329 and MM96L melanoma cells. Although these findings suggest that PHEC-66 has promising potential as a pharmacotherapeutic agent for melanoma treatment, further research is necessary to evaluate its safety, efficacy, and clinical applications.

B-Raf inhibitor vemurafenib counteracts sulfur mustard-induced epidermal impairment through MAPK/ERK signaling

The chemical warfare agent sulfur mustard (SM) causes severe cutaneous lesions characterized by epidermal cell death, apoptosis, and inflammation. At present, the molecular mechanisms underlying SM-induced injury are not well understood, and there is no standard treatment protocol for SM-exposed patients. Here, we conducted a high-content screening of the Food and Drug Administration (FDA)-approved drug library of 1018 compounds against SM injury on an immortal human keratinocyte HaCaT cell line, focusing on cell survival. We found that the B-Raf inhibitor vemurafenib had an apparent therapeutic effect on HaCaT cells and resisted SM toxicity. Other tested B-Raf inhibitors, both type-I (dabrafenib and encorafenib) and type-II (RAF265 and AZ628), also exhibited potent therapeutic effects on SM-exposed HaCaT cells. Both SM and vemurafenib triggered extracellular signal-related kinase (ERK) activation. The therapeutic effect of vemurafenib in HaCaT cells during SM injury was ERK-dependent, indicating a specific role of ERK in keratinocyte regulatory mechanisms. Furthermore, vemurafenib partially improved cutaneous damage in a mouse ear vesicant model. Collectively, our results provide evidence that the B-Raf inhibitor vemurafenib is a potential therapeutic agent against SM injury, and oncogenic B-Raf might be an exciting new therapeutic target following exposure to mustard vesicating agents.

Some things old, new and borrowed: Delivery of dabrafenib and vemurafenib to melanoma cells via self-assembled nanomicelles based on an amphiphilic dendrimer

Two clinically approved anticancer drugs targeting BRAF in melanoma patients - dabrafenib (DAB) and vemurafenib (VEM) - have been successfully encapsulated into nanomicelles formed upon self-assembly of an amphiphilic dendrimer AD based on two C₁₈ aliphatic chains and a G2 PAMAM head. The process resulted in the formation of well-defined (∼10 nm) core-shell nanomicelles (NMs) with excellent encapsulation efficiency (∼70% for DAB and ∼60% for VEM) and good drug loading capacity (∼27% and ∼24% for DAB and VEM, respectively). Dynamic light scattering (DLS), transmission electron microscopy (TEM), small-angle x-ray scattering (SAXS), nuclear magnetic resonance (NMR), isothermal titration calorimetry (ITC), and molecular simulation (MS) experiments were used, respectively, to determine the size and structure of the empty and drug-loaded nanomicelles (DLNMs), along with the interactions between the NMs and their cargoes. The in vitro release data revealed profiles governed by Fickian diffusion; moreover, for both anticancer molecules, an acidic environment (pH = 5.0) facilitated drug release with respect to physiological pH conditions (pH = 7.4). Finally, both DAB- and VEM-loaded NMs elicited enhanced response with respect to free drug treatments in 4 different melanoma cell lines.

Targeting the epigenome in malignant melanoma: Facts, challenges and therapeutic promises

Malignant melanoma is the most lethal type of skin cancer with high rates of mortality. Although current treatment options provide a short-clinical benefit, acquired-drug resistance highlights the low 5-year survival rate among patients with advanced stage of the disease. In parallel, the involvement of an aberrant epigenetic landscape, (e.g., alterations in DNA methylation patterns, histone modifications marks and expression of non-coding RNAs), in addition to the genetic background, has been also associated with the onset and progression of melanoma. In this review article, we report on current therapeutic options in melanoma treatment with a focus on distinct epigenetic alterations and how their reversal, by specific drug compounds, can restore a normal phenotype. In particular, we concentrate on how single and/or combinatorial therapeutic approaches have utilized epigenetic drug compounds in being effective against malignant melanoma. Finally, the role of deregulated epigenetic mechanisms in promoting drug resistance to targeted therapies and immune checkpoint inhibitors is presented leading to the development of newly synthesized and/or improved drug compounds capable of targeting the epigenome of malignant melanoma.

Blood-brain barrier penetration prediction enhanced by uncertainty estimation

Blood–brain barrier is a pivotal factor to be considered in the process of central nervous system (CNS) drug development, and it is of great significance to rapidly explore the blood–brain barrier permeability (BBBp) of compounds in silico in early drug discovery process. Here, we focus on whether and how uncertainty estimation methods improve in silico BBBp models. We briefly surveyed the current state of in silico BBBp prediction and uncertainty estimation methods of deep learning models, and curated an independent dataset to determine the reliability of the state-of-the-art algorithms. The results exhibit that, despite the comparable performance on BBBp prediction between graph neural networks-based deep learning models and conventional physicochemical-based machine learning models, the GROVER-BBBp model shows greatly improvement when using uncertainty estimations. In particular, the strategy combined Entropy and MC-dropout can increase the accuracy of distinguishing BBB + from BBB − to above 99% by extracting predictions with high confidence level (uncertainty score < 0.1). Case studies on preclinical/clinical drugs for Alzheimer’ s disease and marketed antitumor drugs that verified by literature proved the application value of uncertainty estimation enhanced BBBp prediction model, that may facilitate the drug discovery in the field of CNS diseases and metastatic brain tumors.

Keratoacanthoma: Update on the Debate

ABSTRACT

Keratoacanthoma (KA) is a cutaneous tumor with a biphasic pattern of growth. A rapidly growing phase is usually followed by involution. KA occurs on sun-damaged skin. There are many listed causative associations, which include some therapeutic agents. Debate continues as to whether KA is a variant of squamous carcinoma (SCC) or a separate entity. Reporting of KA versus SCC is markedly inconsistent. Reasons for inconsistency include overlapping microscopic criteria, variants of KA with more aggressive features, and possibly medicolegal concerns. Genetic studies have shown some differences between the 2 entities. Activation of apoptotic pathways has been demonstrated in KA. Genetic studies have shown a possible role of human polyomavirus 6 in the pathogenesis of at least some KAs. Given that some cases of KA have components that behave as conventional SCCs, KA can be considered as a low-grade variant of SCC with some genetic differences.

Encorafenib enhances TRAIL-induced apoptosis of colorectal cancer cells dependent on p53/PUMA signaling

TRAIL has been demonstrated to play a critical role in the apoptosis of colorectal cancer (CRC) cells, but drug resistance markedly restricts its therapeutic effects. Objectives: This study aims to investigate whether encorafenib can enhance TRAIL-induced apoptosis of colorectal cancer cells and the underlying mechanism. TRAIL was first used to induce CRC cells. CCK-8 assays were conducted for detecting cell viability of TRAIL-induced CRC cells with encorafenib treatment. Flow cytometry was used to detect the cell apoptosis of CRC cells and western blot was used to measure the expressions of apoptosis-related proteins. The expressions of DR4, DR5, p53, and PUMA were then evaluated by qPCR and western blot. After transfecting the interference plasmid of p53 into CRC cells, the expressions of PUMA and DR5 were further explored. TRAIL reduced the cell viability of CRC cells, and the inhibition was further reinforced under co-treatment of TRAIL and encorafenib. Encorafenib also triggered the promotion of CRC cell apoptosis induced by TRAIL. It was also found that encorafenib exerted its promoting effects on cell apoptosis of CRC cells via the elevation of DR5. Besides, encorafenib administration promoted the expression levels of p53 and PUMA in TRAIL-induced CRC cells. Furthermore, p53 knockdown attenuated the expression of PUMA and DR5 in TRAIL-induced CRC cells treated with encorafenib. This study indicates that encorafenib stimulates TRAIL-induced apoptosis of CRC cells dependent on p53/PUMA signaling, which may provide instructions for the treatment of CRC.