Acquired drug resistance is the major cause for disease recurrence in cancer patients, and this is particularly true for patients with metastatic melanoma that carry a BRAF mutation. To address this problem, we investigated cyclic membrane-active peptides as an alternative therapeutic modality to kill drug-tolerant and resistant melanoma cells to avoid acquired drug resistance. We selected two stable cyclic peptides (cTI and cGm), previously shown to have anti-melanoma properties, and compared them with dabrafenib, a drug used to treat cancer patients with the BRAF mutation.
View Article and Find Full Text PDFAims: Drivers of the drug tolerant proliferative persister (DTPP) state have not been well investigated. Histone H3 lysine-4 trimethylation (H3K4me3), an active histone mark, might enable slow cycling drug tolerant persisters (DTP) to regain proliferative capacity. This study aimed to determine H3K4me3 transcriptionally active sites identifying a key regulator of DTPPs.
View Article and Find Full Text PDFBackground: Immunosuppressed organ-transplant recipients have an increased incidence of, and mortality from, skin cancer. Nicotinamide (vitamin B) enhances the repair of ultraviolet (UV) radiation-induced DNA damage, reduces the cutaneous immunosuppressive effects of UV radiation, and reduces the incidence of keratinocyte cancers (including squamous-cell and basal-cell carcinomas) and actinic keratoses among high-risk immunocompetent patients. Whether oral nicotinamide is useful for skin-cancer chemoprevention in organ-transplant recipients is unclear.
View Article and Find Full Text PDFBackground: Digital 3D total-body photography of the skin surface is an emerging imaging modality that can facilitate the identification of new and changing nevi.
Objective: We aimed to describe the experiences of study participants drawn from the general population who were provided 3D total-body photography and dermoscopy for the monitoring of nevi.
Methods: A population-based prospective study of adults aged 20-70 years from South East Queensland, Australia was conducted.
Immunotherapies and targeted therapies have shown significant benefits for melanoma survival in the clinical trial setting. Much less is known about the characteristics and associated outcomes of those receiving such therapies in real-world settings. This study describes the characteristics of patients with advanced melanoma receiving immuno- and/or targeted therapies in a real-world setting.
View Article and Find Full Text PDFAcquired melanocytic nevi grow and persist in a stable form into adulthood. Using genome-wide methylation profiling, we evaluated 32 histopathologically and dermoscopically characterized nevi to identify the key epigenetic regulatory mechanisms involved in nevogenesis. Benign (69% globular and 31% nonspecific dermoscopic pattern) and dysplastic (95% reticular/nonspecific dermoscopic pattern) nevi were dissimilar, with only two shared differentially methylated loci.
View Article and Find Full Text PDFAmelanotic/hypomelanotic melanoma is a clinicopathologic subtype with absent or minimal melanin. This study assessed previously reported coding variants in albinism genes (TYR, OCA2, TYRP1, SLC45A2, SLC24A5, LRMDA) and common intronic, regulatory variants of OCA2 in individuals with amelanotic/hypomelanotic melanoma, pigmented melanoma cases and controls. Exome sequencing was available for 28 individuals with amelanotic/hypomelanotic melanoma and 303 individuals with pigmented melanoma, which were compared to whole exome data from 1144 Australian controls.
View Article and Find Full Text PDFDespite the recent advances in the treatment of cancers, acquired drug resistance remains a major challenge in cancer management. While earlier studies suggest Darwinian factors driving acquired drug resistance, recent studies point to a more dynamic process involving phenotypic plasticity and tumor heterogeneity in the evolution of acquired drug resistance. Chronic stress after drug treatment induces intrinsic cellular reprogramming and cancer stemness through a slow-cycling persister state, which subsequently drives cancer progression.
View Article and Find Full Text PDFTo investigate the integrated epigenetic regulation of acquired drug resistance in cancer. Our gene expression data of five induced drug-tolerant cell models, one resistant cell line and one publicly available drug-resistant dataset were integrated to identify common differentially expressed genes and pathways. ChIP-seq and DNA methylation by HM450K beadchip were used to study the epigenetic profile of differential expressed genes.
View Article and Find Full Text PDFMelanoma is a leading cause of high mortality that frequently spreads to the brain and is associated with deterioration in quality and quantity of life. Treatment opportunities have been restricted until now and new therapy options are urgently required. Our focus was to reveal the potential heterogeneity of melanoma brain metastasis.
View Article and Find Full Text PDFBackground: A multitude of recent studies has observed common epigenetic changes develop in tumour cells of multiple lineages following exposure to stresses such as hypoxia, chemotherapeutics, immunotherapy or targeted therapies. A significant increase in the transcriptionally repressive mark trimethylated H3K9 (H3K9me3) is becoming associated with treatment-resistant phenotypes suggesting upstream mechanisms may be a good target for therapy. We have reported that the increase in H3K9me3 is derived from the methyltransferases SETDB1 and SETDB2 following treatment in melanoma, lung, breast and colorectal cancer cell lines, as well as melanoma patient data.
View Article and Find Full Text PDFMost BRAF-mutant melanoma patients experience a fulminate relapse after several months of treatment with BRAF/MEK inhibitors. To improve therapeutic efficacy, natural plant-derived compounds might be considered as potent additives. Here, we show that magnolol, a constituent of Magnolia officinalis, induced G1 arrest, apoptosis and cell death in BRAF- and NRAS-mutant melanoma cells at low concentration, with no effect in BRAF- and NRAS wild-type melanoma cells and human keratinocytes.
View Article and Find Full Text PDFBackground And Objectives: In-transit melanoma (ITM) metastases present a therapeutic challenge and management decisions can be difficult. There are multiple treatments available, with differing efficacy, and supported by different levels of evidence. The primary objective was to perform a systematic review and where suitable, a meta-analysis of the literature reporting on the use of locoregional treatments for the management of ITM.
View Article and Find Full Text PDFCalciphylaxis is a rare but life-threatening condition, most commonly affecting patients with stage 4 or 5 chronic kidney disease. No universally accepted therapy exists so far. In an attempt to avoid surgical intervention with parathyroidectomy, which is of questionable efficacy and carries several risks, a number of noninvasive treatments have been trialled with variable success.
View Article and Find Full Text PDFIntroduction: Having many melanocytic naevi or 'moles' on the skin is the strongest predictor of melanoma; thus, much can be learnt from investigating naevi in the general population. We aim to improve the understanding of the epidemiology and biology of naevi by conducting a 3-year prospective study of melanocytic naevi in adults.
Methods And Analysis: This is a population-based cohort study of melanocytic naevi in 200 adults aged 20-69 years recruited via the Australian electoral roll.
EGFR overexpression is associated with squamous cell carcinoma development. Altered endocytosis and polarization of receptor tyrosine kinases, including EGFR, affect migration and invasion in three-dimensional culture. These studies have been completed via genetic sequencing, cell line, or three-dimensional in vitro and in vivo murine models.
View Article and Find Full Text PDFBesides somatic mutations or drug efflux, epigenetic reprogramming can lead to acquired drug resistance. We recently have identified early stress-induced multi-drug tolerant cancer cells termed induced drug-tolerant cells (IDTCs). Here, IDTCs were generated using different types of cancer cell lines; melanoma, lung, breast and colon cancer.
View Article and Find Full Text PDFThe melanoma transformation rate of an individual nevus is very low despite the detection of oncogenic BRAF or NRAS mutations in 100% of nevi. Acquired melanocytic nevi do, however, mimic melanoma, and approximately 30% of all melanomas arise within pre-existing nevi. Using whole-exome sequencing of 30 matched nevi, adjacent normal skin, and saliva we sought to identify the underlying genetic mechanisms for nevus development.
View Article and Find Full Text PDF