The use of circulating cell-free tumor DNA in routine diagnostics of metastatic melanoma patients

Modern advances in technology such as next-generation sequencing and digital PCR make detection of minor circulating cell-free tumor DNA amounts in blood from cancer patients possible. Samples can be obtained minimal-invasively, tested for treatment-determining genetic alterations and are considered to reflect the genetic constitution of the whole tumor mass. Furthermore, tumor development can be determined by a time course of the quantified circulating cell-free tumor DNA. However, systematic studies which prove the clinical relevance of monitoring patients using liquid biopsies are still lacking. In this study, we collected 115 samples from 47 late stage melanoma patients over 1.5 years alongside therapy-associated clinical routine monitoring. Mutation status was confirmed by molecular analysis of primary tumor material. We can show that detectable levels of circulating cell-free tumor DNA correlate with clinical development over time. Increasing levels of circulating cell-free tumor DNA during melanoma treatment with either targeted therapy (BRAF/MEK inhibitors) or immunotherapy, during recovery time or the intervals between last treatment cycle and second-line treatment point towards clinical progression before the progression becomes obvious in imaging. Therefore, this is a further possibility to closely screen our patients for tumor progression during therapy, in therapy-free phases and in earlier stages before therapy initiation

Thyroid hormones enhance mitochondrial function in human epidermis

Since it is unknown whether thyroid hormones (THs) regulate mitochondrial function in human epidermis, we treated organ-cultured human skin, or isolated cultured human epidermal keratinocytes, with triiodothyronine (100 pmol/L) or thyroxine (100 nmol/L). Both THs significantly increased protein expression of the mitochondrially encoded cytochrome C oxidase I (MTCO1), complex I activity, and the number of perinuclear mitochondria. Triiodothyronine also increased mitochondrial transcription factor A (TFAM) protein expression, and thyroxine stimulated complex II/IV activity. Increased mitochondrial function can correlate with increased reactive oxygen species production, DNA damage, and accelerated tissue aging. However, THs neither raised reactive oxygen species production or matrix metalloproteinase-1, -2 and -9 activity nor decreased sirtuin1 (Sirt1) immunoreactivity. Instead, triiodothyronine increased sirtuin-1, fibrillin-1, proliferator-activated receptor-gamma 1-alpha (PGC1 alpha), collagen I and III transcription, and thyroxine decreased cyclin-dependent kinase inhibitor 2A (p16(ink4)) expression in organ-cultured human skin. Moreover, TH treatment increased intracutaneous fibrillin-rich microfibril and collagen III deposition and decreased mammalian target of rapamycin (mTORC1/2) expression ex vivo. This identifies THs as potent endocrine stimulators of mitochondrial function in human epidermis, which down-regulates rather than enhance the expression of skin aging-related biomarkers ex vivo. Therefore, topically applied THs deserve further exploration as candidate agents for treating skin conditions characterized by reduced mitochondrial function

Predicting risk for seroma development after axillary or inguinal sentinel lymph node biopsy in melanoma patients

Background Sentinel lymph node biopsy (SLNB) is currently a routine procedure in the staging of patients with cutaneous melanoma; however, little information is available about the risk factors for postoperative complications, especially for the risk of seroma formation. Methods Medical records of patients undergoing SLNB at the University Hospital of Cologne, Germany, between 2011 and 2016, were reviewed. Binary logistic regression was used to analyze the influence of a wide range of variables on seroma development. Results A total of 615 patients were included in the study. Overall, 20.4% of patients developed complications with seroma being the most common postoperative complication. Development of seroma was significantly more common among smokers than nonsmokers (OR = 1.956, P = 0.007). Inguinal localization (OR = 3.644, P < 0.0001) was also associated with seroma formation. Male patients developed a seroma significantly more often than female patients following SLNB (OR = 2.104, P = 0.001). The presence or absence of metastasis in the lymph node did not influence seroma development. Conclusions Male sex, inguinal localization, and smoking are risk factors for the development of seroma

Single-slice CT measurements allow for accurate assessment of sarcopenia and body composition

Objectives To evaluate the correlation between simple planimetric measurements in axial computed tomography (CT) slices and measurements of patient body composition and anthropometric data performed with bioelectrical impedance analysis (BIA) and metric clinical assessments. Methods In this prospective cross-sectional study, we analyzed data of a cohort of 62 consecutive, untreated adult patients with advanced malignant melanoma who underwent concurrent BIA assessments at their radiologic baseline staging by CT between July 2016 and October 2017. To assess muscle and adipose tissue mass, we analyzed the areas of the paraspinal muscles as well as the cross-sectional total patient area in a single CT slice at the height of the third lumbar vertebra. These measurements were subsequently correlated with anthropometric (body weight) and body composition parameters derived from BIA (muscle mass, fat mass, fat-free mass, and visceral fat mass). Linear regression models were built to allow for estimation of each parameter based on CT measurements. Results Linear regression models allowed for accurate prediction of patient body weight (adjusted R-2 = 0.886), absolute muscle mass (adjusted R-2 = 0.866), fat-free mass (adjusted R-2 = 0.855), and total as well as visceral fat mass (adjusted R-2 = 0.887 and 0.839, respectively). Conclusions Our data suggest that patient body composition can accurately and quantitatively be determined by using simple measurements in a single axial CT slice. This could be useful in various medical and scientific settings, where the knowledge of the patient's anthropometric parameters is not immediately or easily available

Thyrotropin powers human mitochondria

Here we demonstrate that the neuropeptide hormone thyrotropin (TSH), which controls thyroid hormone production, exerts a major nonclassical function in mitochondrial biology. Based on transcriptional, ultrastructural, immunohistochemical, and biochemical evidence, TSH up‐regulates mitochondrial biogenesis and consequently activity in organ‐cultured normal human epidermis in situ. Mitochondrial activity was assessed by measuring 2 key components of the respiratory chain. The abundance of mitochondria was assessed employing 2 independent morphological techniques: counting their numbers in human epidermis by high‐magnification light microscopy of skin sections immunostained for mitochondria‐selective cytochrome‐c‐oxidase subunit 1 (MTCO1) and transmission electron microscopy (TEM). Treatment with 10 mU/ml of TSH for 6 d strongly up‐regulates the number of light‐microscopically visualized, MTCO1‐demarcated mitochondria. On the ultrastructural level, TEM confirms that TSH indeed stimulates mitochondrial proliferation and biogenesis in the perinuclear region of human skin epidermal keratinocytes. On the transcriptional level, TSH up‐regulates MTCO1 mRNA (quantitative RT‐PCR) and significantly enhances complex I and IV (cytochrome‐c‐oxidase) activity. This study pioneers the concept that mitochondrial energy metabolism and biogenesis in a normal, prototypic human epithelial tissue underlies potent neuroendocrine controls and introduces human skin organ culture as a clinically relevant tool for further exploring this novel research frontier in the control of mitochondrial biology.—Poeggeler, B., Knuever, J., Gáspár, E., Bíró, T., Klinger, M., Bodó, E., Wiesner, R J., Wenzel, B. E., Paus, R. Thyrotropin powers human mitochondria. FASEB J. 24, 1525–1531 (2010). www.fasebj.or

Hypothalamic-pituitary-thyroid axis hormones stimulate mitochondrial function and biogenesis in human hair follicles

Thyroid hormones regulate mitochondrial function. As other hypothalamic-pituitary-thyroid (HPT) axis hormones, i.e., thyrotropin-releasing hormone (TRH) and thyrotropin (TSH), are expressed in human hair follicles (HFs) and regulate mitochondrial function in human epidermis, we investigated in organ-cultured human scalp HFs whether TRH (30 nM), TSH (10 mU ml(-1)), thyroxine (T4) (100 nM), and triiodothyronine (T3) (100 pM) alter intrafollicular mitochondrial energy metabolism. All HPT-axis members increased gene and protein expression of mitochondrial-encoded subunit 1 of cytochrome c oxidase (MTCO1), a subunit of respiratory chain complex IV, mitochondrial transcription factor A (TFAM), and Porin. All hormones also stimulated intrafollicular complex I/IV activity and mitochondrial biogenesis. The TSH effects on MTCO1, TFAM, and porin could be abolished by K1-70, a TSH-receptor antagonist, suggesting a TSH receptor-mediated action. Notably, as measured by calorimetry, T3 and TSH increased follicular heat production, whereas T3/T4 and TRH stimulated ATP production in cultured HF keratinocytes. HPT-axis hormones did not increase reactive oxygen species (ROS) production. Rather, T3 and T4 reduced ROS formation, and all tested HPT-axis hormones increased the transcription of ROS scavengers (catalase, superoxide dismutase 2) in HF keratinocytes. Thus, mitochondrial biology, energy metabolism, and redox state of human HFs are subject to profound (neuro-)endocrine regulation by HPT-axis hormones. The neuroendocrine control of mitochondrial biology in a complex human mini-organ revealed here may be therapeutically exploitable

Thyrotropin-Releasing Hormone Controls Mitochondrial Biology in Human Epidermis

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Myeloid Cell-Restricted Insulin/IGF-1 Receptor Deficiency Protects against Skin Inflammation

Myeloid cells are key regulators of tissue homeostasis and disease. Alterations in cell-autonomous insulin/IGF-1 signaling in myeloid cells have recently been implicated in the development of systemic inflammation and insulin-resistant diabetes mellitus type 2 (DM). Impaired wound healing and inflammatory skin diseases are frequent DM-associated skin pathologies, yet the underlying mechanisms are elusive. In this study, we investigated whether myeloid cell-restricted IR/IGF-1R signaling provides a pathophysiologic link between systemic insulin resistance and the development of cutaneous inflammation. Therefore, we generated mice lacking both the insulin and IGF-1 receptor in myeloid cells (IR/IGF-1R(MKO)). Whereas the kinetics of wound closure following acute skin injury was similar in control and IR/IGF-1R(MKO) mice, in two different conditions of dermatitis either induced by repetitive topical applications of the detergent SDS or by high-dose UV B radiation, IR/IGF-1R(MKO) mice were protected from inflammation, whereas controls developed severe skin dermatitis. Notably, whereas during the early phase in both inflammatory conditions the induction of epidermal proinflammatory cytokine expression was similar in control and IR/IGF-1R(MKO) mice, during the late stage, epidermal cytokine expression was sustained in controls but virtually abrogated in IR/IGF-1R(MKO) mice. This distinct kinetic of epidermal cytokine expression was paralleled by proinflammatory macrophage activation in controls and a noninflammatory phenotype in mutants. Collectively, our findings provide evidence for a proinflammatory IR/IGF-1R-dependent pathway in myeloid cells that plays a critical role in the dynamics of an epidermal-dermal cross-talk in cutaneous inflammatory responses, and may add to the mechanistic understanding of diseases associated with disturbances in myeloid cell IR/IGF-1R signaling, including DM

Thyrotropin-Releasing Hormone Selectively Stimulates Human Hair Follicle Pigmentation

In amphibians, thyrotropin-releasing hormone (TRH) stimulates skin melanophores by inducing secretion of α-melanocyte-stimulating hormone in the pituitary gland. However, it is unknown whether this tripeptide neurohormone exerts any direct effects on pigment cells, namely, on human melanocytes, under physiological conditions. Therefore, we have investigated whether TRH stimulates pigment production in organ-cultured human hair follicles (HFs), the epithelium of which expresses both TRH and its receptor, and/or in full-thickness human skin in situ. TRH stimulated melanin synthesis, tyrosinase transcription and activity, melanosome formation, melanocyte dendricity, gp100 immunoreactivity, and microphthalmia-associated transcription factor expression in human HFs in a pituitary gland-independent manner. TRH also stimulated proliferation, gp100 expression, tyrosinase activity, and dendricity of isolated human HF melanocytes. However, intraepidermal melanogenesis was unaffected. As TRH upregulated the intrafollicular production of “pituitary” neurohormones (proopiomelanocortin transcription and ACTH immunoreactivity) and as agouti-signaling protein counteracted TRH-induced HF pigmentation, these pigmentary TRH effects may be mediated in part by locally generated melanocortins and/or by MC-1 signaling. Our study introduces TRH as a novel, potent, selective, and evolutionarily highly conserved neuroendocrine factor controlling human pigmentation in situ. This physiologically relevant and melanocyte sub-population-specific neuroendocrine control of human pigmentation deserves clinical exploration, e.g., for preventing or reversing hair graying. JID JOURNAL CLUB ARTICLE: For questions, answers, and open discussion about this article, please go to http://www.nature.com/jid/journalclu