sFRP2 in the aged microenvironment drives melanoma metastasis and therapy resistance.

Cancer is a disease of ageing. Clinically, aged cancer patients tend to have a poorer prognosis than young. This may be due to accumulated cellular damage, decreases in adaptive immunity, and chronic inflammation. However, the effects of the aged microenvironment on tumour progression have been largely unexplored. Since dermal fibroblasts can have profound impacts on melanoma progression, we examined whether age-related changes in dermal fibroblasts could drive melanoma metastasis and response to targeted therapy. Here we find that aged fibroblasts secrete a Wnt antagonist, sFRP2, which activates a multi-step signalling cascade in melanoma cells that results in a decrease in ß-catenin and microphthalmia-associated transcription factor (MITF), and ultimately the loss of a key redox effector, APE1. Loss of APE1 attenuates the response of melanoma cells to DNA damage induced by reactive oxygen species, rendering the cells more resistant to targeted therapy (vemurafenib). Age-related increases in sFRP2 also augment both angiogenesis and metastasis of melanoma cells. These data provide an integrated view of how fibroblasts in the aged microenvironment contribute to tumour progression, offering new possibilities for the design of therapy for the elderly.

MYC oncogene overexpression drives renal cell carcinoma in a mouse model through glutamine metabolism.

The MYC oncogene is frequently mutated and overexpressed in human renal cell carcinoma (RCC). However, there have been no studies on the causative role of MYC or any other oncogene in the initiation or maintenance of kidney tumorigenesis. Here, we show through a conditional transgenic mouse model that the MYC oncogene, but not the RAS oncogene, initiates and maintains RCC. Desorption electrospray ionization-mass-spectrometric imaging was used to obtain chemical maps of metabolites and lipids in the mouse RCC samples. Gene expression analysis revealed that the mouse tumors mimicked human RCC. The data suggested that MYC-induced RCC up-regulated the glutaminolytic pathway instead of the glycolytic pathway. The pharmacologic inhibition of glutamine metabolism with bis-2-(5-phenylacetamido-1,2,4-thiadiazol-2-yl)ethyl sulfide impeded MYC-mediated RCC tumor progression. Our studies demonstrate that MYC overexpression causes RCC and points to the inhibition of glutamine metabolism as a potential therapeutic approach for the treatment of this disease.

Prophylactic Use of Ramelteon for Delirium in Hospitalized Patients: A Systematic Review and Meta-Analyses.

BACKGROUND: Small prospective studies, case reports, as well as some randomized placebo-controlled trials and previous meta-analyses have shown that ramelteon, a melatonin agonist, may reduce the risk of developing delirium. OBJECTIVE: The goal of this systemic review and meta-analyses was to assess the current evidence supporting the use of ramelteon in delirium prevention by including data from larger (>100 subjects) and more recent trials since the most recent meta-analyses were published in 2019. There were no exclusions for trial size, age, ramelteon dose, length of treatment, or hospital setting. METHODS: Medline, Embase, PsycINFO, EBM Reviews, Scopus, and Web of Science databases were queried using the search terms delirium (with subterms including prevention and control), ramelteon, Rozerem, or melatonin receptor agonists, for English-language publications until March 16, 2021. Randomized placebo-controlled trials of hospitalized subjects receiving ramelteon for delirium prevention were included. The primary outcome of interest was delirium incidence. Odds ratios of the risk of developing incident delirium and 95% confidence intervals were calculated using a random effects model. RESULTS: A total of 177 articles were identified by the literature search. Five studies (n = 443, 53.7% male) met criteria for inclusion in the final meta-analyses. The meta-analyses of the randomized placebo-controlled trials revealed that ramelteon did not result in a reduction in the risk of incident delirium (n = 443; odds ratio = 0.49; 95% confidence interval = 0.13-1.85). A moderate degree of heterogeneity was noted among the studies (I2 = 53%). CONCLUSIONS: Current evidence suggests that ramelteon is ineffective as a prophylactic drug in reducing the incidence of delirium in hospitalized patients.

Association between early childhood sleep difficulties and subsequent psychiatric illness.

STUDY OBJECTIVES: Chronic disruptions to sleep in childhood are associated with increased prevalence of psychiatric disease later in development. When sleep disruptions remit before adolescence, the increased prevalence of psychiatric disease is no longer observed, highlighting the importance of early detection and intervention. Clinicians typically rely on caregivers' reports for diagnosis and management of childhood sleep challenges. We examined whether findings on polysomnogram (PSG) can offer similar insight into childhood sleep difficulties and the risk of subsequent psychiatric illness. METHODS: A cohort was identified of 348 children ages 5 years 11 months and younger with sleep difficulties rising to the level of formal clinical workup. A retrospective review of caregiver-reported sleep concerns, PSG results, and subsequent psychiatric illness was completed. PSG findings were compared to presence of psychiatric illness later in life as well as caregivers' reported concerns. Chi-squared and Fisher's exact tests were completed to evaluate correlations and Cohen's kappa was used to evaluate agreement. RESULTS: With only a few exceptions, comparisons between clinician findings on PSG and subsequent psychiatric diagnoses were statistically nonsignificant. Similarly, the relationship between caregivers' subjective reports about sleep and clinicians' findings on PSG demonstrated only slight to fair agreement, suggesting reported concerns were not predictive of PSG results. CONCLUSIONS: Parental reports of subjective sleep concerns are indicative of different sleep pathologies compared to sleep pathologies detected on PSG. The addition of PSG to caregiver-reported data appears to have limited clinical utility in understanding sleep concerns associated with the risk of subsequent psychiatric illness in young children. CITATION: Pease E, Shekunov J, Savitz ST, et al. Association between early childhood sleep difficulties and subsequent psychiatric illness. J Clin Sleep Med. 2023;19(12):2059-2063.

Inhibition of Age-Related Therapy Resistance in Melanoma by Rosiglitazone-Mediated Induction of Klotho.

Purpose: Aging is a poor prognostic factor for melanoma. We have shown that melanoma cells in an aged microenvironment are more resistant to targeted therapy than identical cells in a young microenvironment. This is dependent on age-related secreted factors. Klotho is an age-related protein whose serum levels decrease dramatically by age 40. Most studies on klotho in cancer have focused on the expression of klotho in the tumor cell. We have shown that exogenous klotho inhibits internalization and signaling of Wnt5A, which drives melanoma metastasis and resistance to targeted therapy. We investigate here whether increasing klotho in the aged microenvironment could be an effective strategy for the treatment of melanoma.Experimental Design: PPARγ increases klotho levels and is increased by glitazones. Using rosiglitazone, we queried the effects of rosiglitazone on Klotho/Wnt5A cross-talk, in vitro and in vivo, and the implications of that for targeted therapy in young versus aged animals.Results: We show that rosiglitazone increases klotho and decreases Wnt5A in tumor cells, reducing the burden of both BRAF inhibitor-sensitive and BRAF inhibitor-resistant tumors in aged, but not young mice. However, when used in combination with PLX4720, tumor burden was reduced in both young and aged mice, even in resistant tumors.Conclusions: Using glitazones as adjuvant therapy for melanoma may provide a new treatment strategy for older melanoma patients who have developed resistance to vemurafenib. As klotho has been shown to play a role in other cancers too, our results may have wide relevance for multiple tumor types. Clin Cancer Res; 23(12); 3181-90. ©2017 AACR.

Wnt5A promotes an adaptive, senescent-like stress response, while continuing to drive invasion in melanoma cells.

We have previously shown that Wnt5A drives invasion in melanoma. We have also shown that Wnt5A promotes resistance to therapy designed to target the BRAF(V600E) mutation in melanoma. Here, we show that melanomas characterized by high levels of Wnt5A respond to therapeutic stress by increasing p21 and expressing classical markers of senescence, including positivity for senescence-associated ß-galactosidase (SA-ß-gal), senescence-associated heterochromatic foci (SAHF), H3K9Me chromatin marks, and PML bodies. We find that despite this, these cells retain their ability to migrate and invade. Further, despite the expression of classic markers of senescence such as SA-ß-gal and SAHF, these Wnt5A-high cells are able to colonize the lungs in in vivo tail vein colony-forming assays. This clearly underscores the fact that these markers do not indicate true senescence in these cells, but instead an adaptive stress response that allows the cells to evade therapy and invade. Notably, silencing Wnt5A reduces expression of these markers and decreases invasiveness. The combined data point to Wnt5A as a master regulator of an adaptive stress response in melanoma, which may contribute to therapy resistance.

Separation of spermatogenic cell types using STA-PUT velocity sedimentation.

Mammalian spermatogenesis is a complex differentiation process that occurs in several stages in the seminiferous tubules of the testes. Currently, there is no reliable cell culture system allowing for spermatogenic differentiation in vitro, and most biological studies of spermatogenic cells require tissue harvest from animal models like the mouse and rat. Because the testis contains numerous cell types--both non-spermatogenic (Leydig, Sertoli, myeloid, and epithelial cells) and spermatogenic (spermatogonia, spermatocytes, round spermatids, condensing spermatids and spermatozoa)--studies of the biological mechanisms involved in spermatogenesis require the isolation and enrichment of these different cell types. The STA-PUT method allows for the separation of a heterogeneous population of cells--in this case, from the testes--through a linear BSA gradient. Individual cell types sediment with different sedimentation velocity according to cell size, and fractions enriched for different cell types can be collected and utilized in further analyses. While the STA-PUT method does not result in highly pure fractions of cell types, e.g. as can be obtained with certain cell sorting methods, it does provide a much higher yield of total cells in each fraction (~1 x 10(8) cells/spermatogenic cell type from a starting population of 7-8 x 10(8) cells). This high yield method requires only specialized glassware and can be performed in any cold room or large refrigerator, making it an ideal method for labs that have limited access to specialized equipment like a fluorescence activated cell sorter (FACS) or elutriator.