The FITNESS study: longitudinal geriatric assessment, treatment toxicity, and biospecimen collection to assess functional disability among older adults with lung cancer.

Introduction: Older adults with chronic disease prioritize functional independence. We aimed to describe the feasibility of capturing functional disability and treatment toxicity among older adults with lung cancer using a longitudinal comprehensive geriatric assessment (CGA) and molecular biomarkers of aging. Methods: This prospective study included adults ≥60 years with any newly diagnosed non-small-cell lung cancer. Participants were recruited from central Ohio (2018-2020). Study assessments included the Cancer and Aging Research Group CGA (CARG-CGA), short physical performance battery (SPPB), and the blessed orientation-memory concentration (BOMC) test at baseline, 3, 6, and 12 months. Activities of daily living (ADLs) and instrumental ADLs (IADLs), quality of life (QoL, PROMIS 10), and treatment toxicity were captured monthly. Stool and blood were collected to characterize the gut microbiome and age-related blood biomarkers. Results: This study enrolled 50 participants with an average age of 71.7 years. Ninety-two percent of participants were Caucasian, 58% were male, and all were non-Hispanic. Most had advanced stage (stage III/IV: 90%; stage I/II: 10%), with adenocarcinoma the predominant histologic subtype (68% vs. 24% squamous). First-line treatments included chemotherapy (44%), immune checkpoint inhibitors (ICIs, 22%), chemotherapy and ICIs (30%), or tyrosine kinase inhibitors (4%). The median baseline CARG toxicity score was 8 (range 2-12). Among patients with treatment-related toxicity (n = 49), 39 (79.6%) cases were mild (grade 1-2), and 10 (20.4%) were moderate to severe (≥ grade 3). Treatment toxicity was greater among those with a CARG score ≥8 (28.0% vs. 13.6%). Higher IADL independence, QoL, and SPPB scores at baseline were positively associated with Candidatus Gastranaerophilales bacterium, Lactobacillus rogosae, and Enterobacteria phage P4. Romboutsia ilealis, Streptococcus, and Lachnoclostridium sp An138 and T cell lag3 and cd8a were associated with worse IADLs, QoL, and SPPB scores at baseline. Discussion: A longitudinal CGA and biomarker collection is feasible among older adults undergoing lung cancer treatment. Gut microbe and T cell gene expression changes correlated with subjective and objective functional status assessments. Future research will test causality in these associations to improve outcomes through novel supportive care interventions to prevent functional disability.

Psychoneuroimmunology in multiple myeloma and autologous hematopoietic stem cell transplant: Opportunities for research among patients and caregivers.

Multiple myeloma (MM) is an incurable cancer and is the leading indication for autologous hematopoietic stem cell transplantation (HSCT). To be eligible for HSCT, a patient must have a caregiver, as caregivers play a central role in HSCT preparation and recovery. MM patients remain on treatment indefinitely, and thus patients and their caregivers face long-term challenges including the intensity of HSCT and perpetual therapy after transplant. Importantly, both patients and their caregivers show heightened depressive and anxiety symptoms, with dyadic correspondence evidenced and caregivers' distress often exceeding that of patients. An extensive psychoneuroimmunology (PNI) literature links distress with health via immune and neuroendocrine dysregulation as well as biological aging. However, data on PNI in the context of multiple myeloma - in patients or caregivers - are remarkably limited. Distress in MM patients has been associated with poorer outcomes including higher inflammation, greater one year post-HSCT hospital readmissions, and worse overall survival. Further, anxiety and depression are linked to biological aging and may contribute to the poor long-term health of both patients and caregivers. Because MM generally affects older adults, individual differences in biological aging may represent an important modifier of MM biology and HSCT treatment outcomes. There are a number of clinical scenarios in which biologically younger people could be prescribed more intensive therapies, with potential for greater benefit, by using a personalized cancer therapy approach based on the quantification of physiologic reserve. Further, despite considerable psychological demands, the effects of distress on health among MM caregivers is largely unexamined. Within this context, the current critical review highlights gaps in knowledge at the intersection of HSCT, inflammation, and biological aging in the context of MM. Research in this area hold promise for opportunities for novel and impactful psychoneuroimmunology (PNI) research to enhance health outcomes, quality of life, and longevity among both MM patients and their caregivers.

Determining the relationship of p16INK4a and additional molecular markers of aging with clinical frailty in hematologic malignancy.

PURPOSE: Older adults with hematologic malignancies (HM) have unique challenges due to age and fitness. The primary aim of this pilot study was to benchmark the ability of multiple biomarkers of aging (p16, epigenetic clocks, T cell gene expression profiles, and T cell receptor excision circles (TREC) to identify frailty as measured by a clinical impairment index (I2) in patients with HM. METHODS: 70 patients newly diagnosed with HM had peripheral blood T lymphocytes (PBTL) analyzed for p16INK4a expression using the OSU_Senescence Nanostring CodeSet. PBTL epigenetic age was measured using 7 epigenetic clocks, and TREC were quantified by qRT-PCR. A composite clinical impairment index (I2) was generated by combining values from 11 geriatric metrics (Independent Activities of Daily Living (iADL), physical health score, Short Physical Performance Battery (SPPB), Body Mass Index (BMI), Eastern Cooperative Oncology Group (ECOG) performance status, self-reported KPS, Blessed Orientation Memory Concentration (BOMC), polypharmacy, Mental Health Inventory (MHI)-17, Medical Outcomes Study (MOS) subscales). Clinical frailty was defined as a score of 7 or greater on the I2. RESULTS: Age-adjusted p16INK4a was similar in newly diagnosed patients and healthy controls (p > 0.1). PBTL p16INK4a levels correlated positively with the Hannum [r = 0.35, 95% CI (0.09-0.75); p adj. = 0.04] and PhenoAge [r = 0.37, 95% CI (0.11-0.59); p adj. = 0.04] epigenetic clocks. The discrimination ability of the I2 model was calculated using the area under the receiver operating characteristic curve (AUC). After adjusting for chronologic age and disease group, baseline p16INK4a [AUC = 0.76, 95% CI (0.56-0.98); p = 0.01], Hannum [AUC = 0.70, 95% CI (0.54-0.85); p = 0.01], PhenoAge [AUC = 0.71, 95% CI (0.55-0.86); p = 0.01], and DunedinPACE [AUC = 0.73, 95% CI (0.57-0.88); p = < 0.01] measures showed the greatest potential to identify clinical frailty using the I2. CONCLUSIONS: Our pilot data suggest that multiple blood-based aging biomarkers have potential to identify frailty in older adults with HM. IMPLICATIONS FOR CANCER SURVIVORS: We developed the I2 index to quantify impairments across geriatric domains and discovered that PBTL p16, Hannum, PhenoAge, and DunedinPACE are promising indicators of frailty in HM.

Gut Microbiota Richness and Diversity Track With T Cell Aging in Healthy Adults.

BACKGROUND: This study examined how gut microbiota diversity and richness relate to T cell aging among 96 healthy adults of all ages. It also explored whether these links differed throughout the lifespan. METHODS: Peripheral blood was obtained from 96 study participants (N = 96, aged 21-72) to assess mRNA markers of T cell aging (p16ink4a, p14ARF, B3gat1, Klrg1) and DNA methylation. T cell aging mRNA markers were combined into an aging index, and the Horvath epigenetic clock algorithm was used to calculate epigenetic age based on DNA methylation status of over 500 loci. Participants also collected a stool sample from which the V4 region of the 16S rRNA gene was sequenced to derive the Shannon and Simpson diversity indices, and the total count of observed operational taxonomic units (richness). Models controlled for BMI, comorbidities, sex, dietary quality, smoking status, physical activity, and sleep quality. RESULTS: Lower microbiota richness was associated with higher T cell age based on mRNA markers, but when probing the region of significance, this relationship was only significant among adults 45 years and older (p = .03). Lower Shannon diversity (p = .05) and richness (p = .07) marginally correlated with higher epigenetic age (ie, greater T cell DNA methylation). CONCLUSIONS: Gut microbiota complexity may correspond with the rate of T cell aging, especially in mid-to-late life. These results suggest an interplay between the gut microbiome and immunological aging that warrants further experimental work.

Understanding the health effects of caregiving stress: New directions in molecular aging.

Dementia caregiving has been linked to multiple health risks, including infectious illness, depression, anxiety, immune dysregulation, weakened vaccine responses, slow wound healing, hypertension, cardiovascular disease, metabolic syndrome, diabetes, frailty, cognitive decline, and reduced structural and functional integrity of the brain. The sustained overproduction of proinflammatory cytokines is a key pathway behind many of these risks. However, contrasting findings suggest that some forms of caregiving may have beneficial effects, such as maintaining caregivers' health and providing a sense of meaning and purpose which, in turn, may contribute to lower rates of functional decline and mortality. The current review synthesizes these disparate literatures, identifies methodological sources of discrepancy, and integrates caregiver research with work on aging biomarkers to propose a research agenda that traces the mechanistic pathways of caregivers' health trajectories with a focus on the unique stressors facing spousal caregivers as compared to other informal caregivers. Combined with a focus on psychosocial moderators and mechanisms, studies using state-of-the-art molecular aging biomarkers such as telomere length, p16INK4a, and epigenetic age could help to reconcile mixed literature on caregiving's sequelae by determining whether and under what conditions caregiving-related experiences contribute to faster aging, in part through inflammatory biology. The biomarkers predict morbidity and mortality, and each contributes non-redundant information about age-related molecular changes -together painting a more complete picture of biological aging. Indeed, assessing changes in these biopsychosocial mechanisms over time would help to clarify the dynamic relationships between caregiving experiences, psychological states, immune function, and aging.

Biological aging in multiple sclerosis.

Multiple sclerosis (MS) is most likely to adopt a progressive clinical course during middle age or beyond, and the number of older adults with MS is steadily increasing. Developing new strategies to manage progressive forms of MS, which do not respond to currently available disease-modifying therapies (DMTs), will require a deeper understanding of the mechanisms by which biological aging interacts with pathogenic pathways to propel disability accumulation. In experimental autoimmune encephalomyelitis (EAE), a widely used preclinical mouse model of MS, middle-aged animals experience a more severe and protracted clinical course than their younger counterparts. This exacerbated disease course is accompanied by persistent neuroinflammation. Clinical studies of age-related biomarkers, such as telomere length, senescence markers, and DNA methylation, suggest that biological aging is accelerated in people with MS compared with age- and sex-matched healthy controls. Furthermore, distinguishing biological age from chronological may afford more precision in determining aging effects in MS. Here we review the current literature on aging biology and its impact on MS pathogenesis. Future research on this topic may lead to the development of novel biomarkers and senotherapy agents that slow neurological decline in people with progressive MS by targeting relevant aging-related pathways.

The OSUMMER lines: A series of ultraviolet-accelerated NRAS-mutant mouse melanoma cell lines syngeneic to C57BL/6.

An increasing number of cancer subtypes are treated with front-line immunotherapy. However, approaches to overcome primary and acquired resistance remain limited. Preclinical mouse models are often used to investigate resistance mechanisms, novel drug combinations, and delivery methods; yet most of these models lack the genetic diversity and mutational patterns observed in human tumors. Here we describe a series of 13 C57BL/6J melanoma cell lines to address this gap in the field. The Ohio State University-Moffitt Melanoma Exposed to Radiation (OSUMMER) cell lines are derived from mice expressing endogenous, melanocyte-specific, and clinically relevant Nras driver mutations (Q61R, Q61K, or Q61L). Exposure of these animals to a single, non-burning dose of ultraviolet B accelerates the onset of spontaneous melanomas with mutational patterns akin to human disease. Furthermore, in vivo irradiation selects against potent tumor antigens, which could prevent the outgrowth of syngeneic cell transfers. Each OSUMMER cell line possesses distinct in vitro growth properties, trametinib sensitivity, mutational signatures, and predicted antigenicity. Analysis of OSUMMER allografts shows a correlation between strong, predicted antigenicity and poor tumor outgrowth. These data suggest that the OSUMMER lines will be a valuable tool for modeling the heterogeneous responses of human melanomas to targeted and immune-based therapies.

Tumour extracellular vesicles and particles induce liver metabolic dysfunction.

Cancer alters the function of multiple organs beyond those targeted by metastasis1,2. Here we show that inflammation, fatty liver and dysregulated metabolism are hallmarks of systemically affected livers in mouse models and in patients with extrahepatic metastasis. We identified tumour-derived extracellular vesicles and particles (EVPs) as crucial mediators of cancer-induced hepatic reprogramming, which could be reversed by reducing tumour EVP secretion via depletion of Rab27a. All EVP subpopulations, exosomes and principally exomeres, could dysregulate hepatic function. The fatty acid cargo of tumour EVPs-particularly palmitic acid-induced secretion of tumour necrosis factor (TNF) by Kupffer cells, generating a pro-inflammatory microenvironment, suppressing fatty acid metabolism and oxidative phosphorylation, and promoting fatty liver formation. Notably, Kupffer cell ablation or TNF blockade markedly decreased tumour-induced fatty liver generation. Tumour implantation or pre-treatment with tumour EVPs diminished cytochrome P450 gene expression and attenuated drug metabolism in a TNF-dependent manner. We also observed fatty liver and decreased cytochrome P450 expression at diagnosis in tumour-free livers of patients with pancreatic cancer who later developed extrahepatic metastasis, highlighting the clinical relevance of our findings. Notably, tumour EVP education enhanced side effects of chemotherapy, including bone marrow suppression and cardiotoxicity, suggesting that metabolic reprogramming of the liver by tumour-derived EVPs may limit chemotherapy tolerance in patients with cancer. Our results reveal how tumour-derived EVPs dysregulate hepatic function and their targetable potential, alongside TNF inhibition, for preventing fatty liver formation and enhancing the efficacy of chemotherapy.

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. We crossed TpN mice heterozygous for an inactivating mutation in Tyrosinase to produce albino and black littermates on a C57BL/6J background. These animals were then exposed to a single UVB dose on postnatal day three when keratinocytes in the skin have yet to be melanized. Approximately one-third (35%) of black mice were protected from UVB-accelerated tumor formation. However, melanoma growth rates, tumor mutational burdens, and gene expression profiles were similar in melanomas from black and albino mice. Skin from albino mice contained more cyclobutane pyrimidine dimer (CPD) positive cells than black mice 1-h post-irradiation. However, this trend gradually reversed over time with CPDs becoming more prominent in black than albino melanocytes at 48 h. These results show that in the absence of epidermal pigmentation, melanocytic melanin limits the tumorigenic effects of acute UV exposure but fails to protect melanocytes from UVB-induced mutagenesis.

The aging lung microenvironment awakens melanoma metastases.

In a recent publication in Nature, Fane et al. establish WNT5A as a central, age-sensitive regulator of the dormancy-to-reactivation axis of melanoma. They show that aged fibroblasts in the lungs suppress WNT5A signaling induced at the primary tumor site to awaken dormant melanoma cells and promote the outgrowth of metastases.

Enhanced BRAF engagement by NRAS mutants capable of promoting melanoma initiation.

A distinct profile of NRAS mutants is observed in each tumor type. It is unclear whether these profiles are determined by mutagenic events or functional differences between NRAS oncoproteins. Here, we establish functional hallmarks of NRAS mutants enriched in human melanoma. We generate eight conditional, knock-in mouse models and show that rare melanoma mutants (NRAS G12D, G13D, G13R, Q61H, and Q61P) are poor drivers of spontaneous melanoma formation, whereas common melanoma mutants (NRAS Q61R, Q61K, or Q61L) induce rapid tumor onset with high penetrance. Molecular dynamics simulations, combined with cell-based protein-protein interaction studies, reveal that melanomagenic NRAS mutants form intramolecular contacts that enhance BRAF binding affinity, BRAF-CRAF heterodimer formation, and MAPK > ERK signaling. Along with the allelic series of conditional mouse models we describe, these results establish a mechanistic basis for the enrichment of specific NRAS mutants in human melanoma.

Peripheral blood CD3+ T-cell gene expression biomarkers correlate with clinical frailty in patients with haematological malignancies.

Older patients with cancer often receive treatment regimens based on their age without considering other objective factors that may influence outcomes. Assessment of frailty can identify older patients who are robust and therefore more likely to benefit from intensive treatment, or conversely, frail and might instead be offered alternative approaches. However, such assessment requires specialised training and dedicated clinical resources. Alternative quantitative biomarkers associated with frailty are lacking. Here, we asked if expression signatures of 74 immune cell, ageing, and senescence-related messenger RNAs in purified peripheral blood T cells could identify associations with clinical frailty in patients with haematological malignancies. We studied 69 patients between the ages of 36 and 92 years (median 76 years) with leukaemia, lymphoma, or multiple myeloma, across two institutions. Expression of four genes (aryl hydrocarbon receptor [AHR], CD27, CD28, and interleukin-2 receptor subunit alpha [IL2RA; CD25]) in T cells was associated with frailty, independent of age. An expression-based regression model had 76% sensitivity and 90% specificity to assign a patient as robust. These data identify measurable peripheral blood correlates of clinical frailty and suggest biomarkers for future prospective assessment.

Topical therapy for regression and melanoma prevention of congenital giant nevi.

Giant congenital melanocytic nevi are NRAS-driven proliferations that may cover up to 80% of the body surface. Their most dangerous consequence is progression to melanoma. This risk often triggers preemptive extensive surgical excisions in childhood, producing severe lifelong challenges. We have presented preclinical models, including multiple genetically engineered mice and xenografted human lesions, which enabled testing locally applied pharmacologic agents to avoid surgery. The murine models permitted the identification of proliferative versus senescent nevus phases and treatments targeting both. These nevi recapitulated the histologic and molecular features of human giant congenital nevi, including the risk of melanoma transformation. Cutaneously delivered MEK, PI3K, and c-KIT inhibitors or proinflammatory squaric acid dibutylester (SADBE) achieved major regressions. SADBE triggered innate immunity that ablated detectable nevocytes, fully prevented melanoma, and regressed human giant nevus xenografts. These findings reveal nevus mechanistic vulnerabilities and suggest opportunities for topical interventions that may alter the therapeutic options for children with congenital giant nevi.

UVB mutagenesis differs in Nras- and Braf-mutant mouse models of melanoma.

BRAF-mutant melanomas are more likely than NRAS-mutant melanomas to arise in anatomical locations protected from chronic sun damage. We hypothesized that this discrepancy in tumor location is a consequence of the differential sensitivity of BRAF and NRAS-mutant melanocytes to ultraviolet light (UV)-mediated carcinogenesis. We tested this hypothesis by comparing the mutagenic consequences of a single neonatal, ultraviolet-AI (UVA; 340-400 nm) or ultraviolet-B (UVB; 280-390 nm) exposure in mouse models heterozygous for mutant Braf or homozygous for mutant Nras Tumor onset was accelerated by UVB, but not UVA, and the resulting melanomas contained recurrent mutations affecting the RING domain of MAP3K1 and Actin-binding domain of Filamin A. Melanomas from UVB-irradiated, Braf-mutant mice averaged twice as many single-nucleotide variants and five times as many dipyrimidine variants than tumors from similarly irradiated Nras-mutant mice. A mutational signature discovered in UVB-accelerated tumors mirrored COSMIC signatures associated with human skin cancer and was more prominent in Braf- than Nras-mutant murine melanomas. These data show that a single UVB exposure yields a greater burden of mutations in murine tumors driven by oncogenic Braf.

An aged immune system drives senescence and ageing of solid organs.

Ageing of the immune system, or immunosenescence, contributes to the morbidity and mortality of the elderly1,2. To define the contribution of immune system ageing to organism ageing, here we selectively deleted Ercc1, which encodes a crucial DNA repair protein3,4, in mouse haematopoietic cells to increase the burden of endogenous DNA damage and thereby senescence5-7 in the immune system only. We show that Vav-iCre+/-;Ercc1-/fl mice were healthy into adulthood, then displayed premature onset of immunosenescence characterized by attrition and senescence of specific immune cell populations and impaired immune function, similar to changes that occur during ageing in wild-type mice8-10. Notably, non-lymphoid organs also showed increased senescence and damage, which suggests that senescent, aged immune cells can promote systemic ageing. The transplantation of splenocytes from Vav-iCre+/-;Ercc1-/fl or aged wild-type mice into young mice induced senescence in trans, whereas the transplantation of young immune cells attenuated senescence. The treatment of Vav-iCre+/-;Ercc1-/fl mice with rapamycin reduced markers of senescence in immune cells and improved immune function11,12. These data demonstrate that an aged, senescent immune system has a causal role in driving systemic ageing and therefore represents a key therapeutic target to extend healthy ageing.

Aging Phenotypes and Restoring Functional Deficits in Older Adults With Hematologic Malignancy.

BACKGROUND: Gauging fitness remains a challenge among older adults with hematologic malignancies, and interventions to restore function are lacking. We pilot a structured exercise intervention and novel biologic correlates of aging using epigenetic clocks and markers of immunosenescence to evaluate changes in function and clinical outcomes. METHODS: Older adults (n=30) with hematologic malignancy actively receiving treatment were screened and enrolled in a 6-month exercise intervention, the Otago Exercise Programme (OEP). The impact of the OEP on geriatric assessment metrics and health-related quality of life were captured. Clinical outcomes of overall survival and hospital utilization (inpatient length of stay and emergency department use) in relationship to geriatric deficits were analyzed. RESULTS: Older adults (median age, 75.5 years [range, 62-83 years]) actively receiving treatment were enrolled in the OEP. Instrumental activities of daily living and physical health scores (PHS) increased significantly with the OEP intervention (median PHS: visit 1, 55 [range, 0-100]; visit 2, 70 [range, 30-100]; P<.01). Patient-reported Karnofsky performance status increased significantly, and the improvement was sustained (median [range]: visit 1, 80 [40-100]; visit 3, 90 [50-100]; P=.05). Quality of life (Patient-Reported Outcome Measurement Information System [PROMIS]) improved significantly by the end of the 6-month period (median [range]: visit 1, 32.4 [19.9-47.7]; visit 3, 36.2 [19.9-47.7]; P=.01]. Enhanced measures of gait speed and balance, using the Short Physical Performance Battery scores, were associated with a 20% decrease in risk of death (hazard ratio, 0.80; 95% CI, 0.65-0.97; P=.03) and a shorter hospital length of stay (decrease of 1.29 days; 95% CI, -2.46 to -0.13; P=.03). Peripheral blood immunosenescent markers were analyzed in relationship to clinical frailty and reports of mPhenoAge epigenetic analysis are preliminarily reported. Chronologic age had no relationship to overall survival, length of stay, or emergency department utilization. CONCLUSIONS: The OEP was effective in improving quality of life, and geriatric tools predicted survival and hospital utilization among older adults with hematologic malignancies.

Targeted Therapy Given after Anti-PD-1 Leads to Prolonged Responses in Mouse Melanoma Models through Sustained Antitumor Immunity.

Immunotherapy (IT) and targeted therapy (TT) are both effective against melanoma, but their combination is frequently toxic. Here, we investigated whether the sequence of IT (anti-PD-1)→ TT (ceritinib-trametinib or dabrafenib-trametinib) was associated with improved antitumor responses in mouse models of BRAF- and NRAS-mutant melanoma. Mice with NRAS-mutant (SW1) or BRAF-mutant (SM1) mouse melanomas were treated with either IT, TT, or the sequence of IT→TT. Tumor volumes were measured, and samples from the NRAS-mutant melanomas were collected for immune-cell analysis, single-cell RNA sequencing (scRNA-seq), and reverse phase protein analysis (RPPA). scRNA-seq demonstrated that the IT→TT sequence modulated the immune environment, leading to increased infiltration of T cells, monocytes, dendritic cells and natural killer cells, and decreased numbers of tumor-associated macrophages, myeloid-derived suppressor cells, and regulatory T cells. Durable responses to the IT→TT sequence were dependent on T-cell activity, with depletion of CD8+, but not CD4+, T cells abrogating the therapeutic response. An analysis of transcriptional heterogeneity in the melanoma compartment showed the sequence of IT→TT enriched for a population of melanoma cells with increased expression of MHC class I and melanoma antigens. RPPA analysis demonstrated that the sustained immune response induced by IT→TT suppressed tumor-intrinsic signaling pathways required for therapeutic escape. These studies establish that upfront IT improves the responses to TT in BRAF- and NRAS-mutant melanoma models.

Melanoma models for the next generation of therapies.

There is a lack of appropriate melanoma models that can be used to evaluate the efficacy of novel therapeutic modalities. Here, we discuss the current state of the art of melanoma models including genetically engineered mouse, patient-derived xenograft, zebrafish, and ex vivo and in vitro models. We also identify five major challenges that can be addressed using such models, including metastasis and tumor dormancy, drug resistance, the melanoma immune response, and the impact of aging and environmental exposures on melanoma progression and drug resistance. Additionally, we discuss the opportunity for building models for rare subtypes of melanomas, which represent an unmet critical need. Finally, we identify key recommendations for melanoma models that may improve accuracy of preclinical testing and predict efficacy in clinical trials, to help usher in the next generation of melanoma therapies.