S6K1 is a Targetable Vulnerability in Tumors Exhibiting Plasticity and Therapy Resistance.

Most tumors initially respond to treatment, yet refractory clones subsequently develop owing to resistance mechanisms associated with cancer cell plasticity and heterogeneity. We used a chemical biology approach to identify protein targets in cancer cells exhibiting diverse driver mutations and representing models of tumor lineage plasticity and therapy resistance. An unbiased screen of a drug library was performed against cancer cells followed by synthesis of chemical analogs of the most effective drug.

Extracellular vesicles released by ALL patients contain HNE-adducted proteins: Implications of collateral damage.

Off-target neuronal injury is a serious side-effect observed in cancer survivors. It has previously been shown that pediatric acute lymphoblastic leukemia (ALL) survivors have a decline in neurocognition compared to healthy age-matched counterparts. Elevated oxidative stress has been documented to be a mediator in off-target tissue damage in cancer survivors.

Implementing and Evaluating a Pilot Interprofessional Training Program to Engage Health Care Teams in Cost of Care Conversations.

Introduction: This study evaluated the impact of Financial and Insurance Navigation Assistance-Training - a pilot interprofessional training program to facilitate cost of care (CoC) conversations and address health-harming social determinants of health in a pediatric hematology-oncology clinic.

Methods: A pre-post study design was used to evaluate the impact of Financial and Insurance Navigation Assistance-Training on an interprofessional health care team's (clinicians, social workers, financial navigator, and legal advocates) knowledge, attitudes, and behaviors related to CoC conversations and screening, referring, and collaborating with interprofessional team members. Data were collected via surveys administered at baseline/pretraining, immediate post-training, and 12-month post-training.

Financial-legal navigation reduces financial toxicity of pediatric, adolescent, and young adult cancers.

Background: Pediatric, adolescent, and young adult patients with cancer and their caregivers are at high risk of financial toxicity, and few evidence-based oncology financial and legal navigation programs exist to address it. We tested the feasibility, acceptability, and preliminary effectiveness of Financial and Insurance Navigation Assistance, a novel interdisciplinary financial and legal navigation intervention for pediatric, adolescent and young adult patients and their caregivers.

Methods: We used a single-arm feasibility and acceptability trial design in a pediatric hematology and oncology clinic and collected preintervention and postintervention surveys to assess changes in financial toxicity (3 domains: psychological response/Comprehensive Score for Financial Toxicity [COST], material conditions, and coping behaviors); health-related quality of life (Patient-Reported Outcomes Measurement Information System Physical and Mental Health, Anxiety, Depression, and Parent Proxy scales); and perceived feasibility, acceptability, and appropriateness.

Two Case Reports on Financial Toxicity and Healthcare Transitions in Adolescent and Young Adult Cancer Survivors.

A team conducted semistructured interviews and developed case reports about financial toxicity (FT) and healthcare transitions (HCTs) with two adolescent and young adult (AYA) cancer survivors. These reports found poor HCTs f.

Distinct cAMP Signaling Microdomains Differentially Regulate Melanosomal pH and Pigmentation.

cAMP signaling is a well-established regulator of melanin synthesis. Two distinct cAMP signaling pathways-the transmembrane adenylyl cyclase pathway, activated primarily by the MC1R, and the soluble adenylyl cyclase (sAC) pathway-affect melanin synthesis. The sAC pathway affects melanin synthesis by regulating melanosomal pH, and the MC1R pathway affects melanin synthesis by regulating gene expression and post-translational modifications.

Integrin α6β4 signals through DNA damage response pathway to sensitize breast cancer cells to cisplatin.

Integrin α6β4 is highly expressed in triple negative breast cancer (TNBC) and drives its most aggressive traits; however, its impact on chemotherapeutic efficacy remains untested. We found that integrin α6β4 signaling promoted sensitivity to cisplatin and carboplatin but not to other chemotherapies tested. Mechanistic investigations revealed that integrin α6β4 stimulated the activation of ATM, p53, and 53BP1, which required the integrin β4 signaling domain.

Cell-intrinsic melanin fails to protect melanocytes from ultraviolet-mutagenesis in the absence of epidermal melanin.

Melanin is a free-radical scavenger, antioxidant, and broadband absorber of ultraviolet (UV) radiation which protects the skin from environmental carcinogenesis. However, melanin synthesis and UV-induced reactive melanin species are also implicated in melanocyte genotoxicity. Here, we attempted to reconcile these disparate functions of melanin using a UVB-sensitive, NRAS-mutant mouse model, TpN.

UV-induced reduction in Polycomb repression promotes epidermal pigmentation.

Ultraviolet (UV) radiation is a prime environmental stressor that our epidermis is exposed to on a daily basis. To avert UV-induced damage, epidermal stem cells (EpSCs) become pigmented via a process of heterotypic interaction between melanocytes and EpSCs; however, the molecular mechanisms of this interaction are not well understood. In this study, we show that the function of a key chromatin regulator, the Polycomb complex, was reduced upon UV exposure in human and mouse epidermis.

Pharmacologic manipulation of skin pigmentation.

Skin complexion is among the most recognizable phenotypes between individuals and is mainly determined by the amount and type of melanin pigment deposited in the epidermis. Persons with dark skin complexion have more of a brown/black pigment known as eumelanin in their epidermis whereas those with fair skin complexions have less. Epidermal eumelanin acts as a natural sunblock by preventing incoming UV photons from penetrating into the skin and therefore protects against UV mutagenesis.

Cutaneous pharmacologic cAMP induction induces melanization of the skin and improves recovery from ultraviolet injury in melanocortin 1 receptor-intact or heterozygous skin.

Homozygous loss of function of the melanocortin 1 receptor (MC1R) is associated with a pheomelanotic pigment phenotype and increased melanoma risk. MC1R heterozygosity is less well studied, although individuals inheriting one loss-of-function MC1R allele are also melanoma-prone. Using the K14-Scf C57BL/6J animal model whose skin is characterized by lifelong retention of interfollicular epidermal melanocytes like that of the human, we studied pigmentary, UV responses, and DNA repair capacity in the skin of variant Mc1r background.

Protective effects of novel derivatives of vitamin D and lumisterol against UVB-induced damage in human keratinocytes involve activation of Nrf2 and p53 defense mechanisms.

We tested whether novel CYP11A1-derived vitamin D- and lumisterol-hydroxyderivatives, including 1,25(OH)D, 20(OH)D, 1,20(OH)D, 20,23(OH)D, 1,20,23(OH)D, lumisterol, 20(OH)L, 22(OH)L, 20,22(OH)L, and 24(OH)L, can protect against UVB-induced damage in human epidermal keratinocytes. Cells were treated with above compounds for 24 h, then subjected to UVB irradiation at UVB doses of 25, 50, 75, or 200 mJ/cm, and then examined for oxidant formation, proliferation, DNA damage, and the expression of genes at the mRNA and protein levels. Oxidant formation and proliferation were determined by the DCFA-DA and MTS assays, respectively.

cAMP-mediated regulation of melanocyte genomic instability: A melanoma-preventive strategy.

Malignant melanoma of the skin is the leading cause of death from skin cancer and ranks fifth in cancer incidence among all cancers in the United States. While melanoma mortality has remained steady for the past several decades, melanoma incidence has been increasing, particularly among fair-skinned individuals. According to the American Cancer Society, nearly 10,000 people in the United States will die from melanoma this year.

Sirtuin 1-mediated deacetylation of XPA DNA repair protein enhances its interaction with ATR protein and promotes cAMP-induced DNA repair of UV damage.

Blunted melanocortin 1 receptor (MC1R) signaling promotes melanocyte genomic instability in part by attenuating cAMP-mediated DNA repair responses, particularly nucleotide excision repair (NER), which recognizes and clears mutagenic photodamage. cAMP-enhanced NER is mediated by interactions between the ataxia telangiectasia-mutated and Rad3-related (ATR) and xeroderma pigmentosum complementation group A (XPA) proteins. We now report a critical role for sirtuin 1 (SIRT1) in regulating ATR-mediated phosphorylation of XPA.

Frontiers in pigment cell and melanoma research.

In this perspective, we identify emerging frontiers in clinical and basic research of melanocyte biology and its associated biomedical disciplines. We describe challenges and opportunities in clinical and basic research of normal and diseased melanocytes that impact current approaches to research in melanoma and the dermatological sciences. We focus on four themes: (1) clinical melanoma research, (2) basic melanoma research, (3) clinical dermatology, and (4) basic pigment cell research, with the goal of outlining current highlights, challenges, and frontiers associated with pigmentation and melanocyte biology.

The melanocortin signaling cAMP axis accelerates repair and reduces mutagenesis of platinum-induced DNA damage.

Using primary melanocytes and HEK293 cells, we found that cAMP signaling accelerates repair of bi- and mono-functional platinum-induced DNA damage. Elevating cAMP signaling either by the agonistic MC1R ligand melanocyte stimulating hormone (MSH) or by pharmacologic cAMP induction by forskolin enhanced clearance of intrastrand cisplatin-adducts in melanocytes or MC1R-transfected HEK293 cells. MC1R antagonists human beta-defensin 3 and agouti signaling protein blocked MSH- but not forskolin-mediated enhancement of platinum-induced DNA damage.

Inorganic arsenic inhibits the nucleotide excision repair pathway and reduces the expression of XPC.

Chronic exposure to arsenic, most often through contaminated drinking water, has been linked to several types of cancer in humans, including skin and lung cancer. However, the mechanisms underlying its role in causing cancer are not well understood. There is evidence that exposure to arsenic can enhance the carcinogenicity of UV light in inducing skin cancers and may enhance the carcinogenicity of tobacco smoke in inducing lung cancers.

Paracrine regulation of melanocyte genomic stability: a focus on nucleotide excision repair.

UV radiation is a major environmental risk factor for the development of melanoma by causing DNA damage and mutations. Resistance to UV damage is largely determined by the capacity of melanocytes to respond to UV injury by repairing mutagenic photolesions. The nucleotide excision repair (NER) pathway is the major mechanism by which cells correct UV photodamage.