Efficiency and tolerance of second-line triple BRAF inhibitor/MEK inhibitor/anti-PD1 combined therapy in BRAF mutated melanoma patients with central nervous system metastases occurring during first-line combined targeted therapy: a real-life survey

Although current systemic therapies significantly improved the outcome of advanced melanoma, the prognosis of patient with central nervous system (CNS) metastases remains poor especially when clinically symptomatic. We aimed to investigate the efficiency of CNS targets and tolerance of second-line combined anti-PD1/dual-targeted anti-BRAF/anti-MEK therapy implemented in patients with CNS progression after initially efficient first-line combined targeted therapy in patients with BRAF-mutated melanoma in a real-life setting. A monocentric retrospective analysis including all such patients treated from January 2017 to January 2022 was conducted in our tertiary referral center. The response of CNS lesions to second-line triple therapy was assessed through monthly clinical and at least quarterly morphological (according to RECIST criteria) evaluation. Tolerance data were also collected. Seventeen patients were included with a mean follow-up of 2.59 (±2.43) months. Only 1 patient displayed a significant clinical and morphological response. No statistically significant difference was observed between patients receiving or not additional local therapy (mainly radiotherapy) as to response achievement. Immunotherapy was permanently discontinued in 1 patient owing to grade 4 toxicity. Mean PFS and OS after CNS progression were 2.59 and 4.12 months, respectively. In this real-life survey, the subsequent addition of anti-PD1 to combined targeted therapy in melanoma patients with upfront CNS metastases did not result in significant response of CNS targets in most BRAF mutated melanoma patients with secondary CNS progression after initially successful first-line combined targeted therapy.

On the robustness of randomized classifiers to adversarial examples

This paper investigates the theory of robustness against adversarial attacks. We focus on randomized classifiers (i.e. classifiers that output random variables) and provide a thorough analysis of their behavior through the lens of statistical learning theory and information theory. To this aim, we introduce a new notion of robustness for randomized classifiers, enforcing local Lipschitzness using probability metrics. Equipped with this definition, we make two new contributions. The first one consists in devising a new upper bound on the adversarial generalization gap of randomized classifiers. More precisely, we devise bounds on the generalization gap and the adversarial gap i.e. the gap between the risk and the worst-case risk under attack) of randomized classifiers. The second contribution presents a yet simple but efficient noise injection method to design robust randomized classifiers. We show that our results are applicable to a wide range of machine learning models under mild hypotheses. We further corroborate our findings with experimental results using deep neural networks on standard image datasets, namely CIFAR-10 and CIFAR-100. On these tasks, we manage to design robust models that simultaneously achieve state-of-the-art accuracy (over 0.82 clean accuracy on CIFAR-10) and enjoy guaranteed robust accuracy bounds (0.45 against $$\ell _{2}$$ ℓ 2 adversaries with magnitude 0.5 on CIFAR-10).

Diagnostic Accuracy of Digital Staining ex vivo Confocal Microscopy for Diagnosing and Subtyping Basal Cell Carcinoma in Fresh Pretherapeutic Punch Biopsies: A Monocentric Prospective Study

BACKGROUND

Ex vivo confocal microscopy using fusion mode and digital staining (EVCM) scans unfixed fresh tissue and produces rapidly digitally stained images of very similar quality to classical pathology. We investigated whether EVCM could represent an alternative to the standard histological examination of the pretherapeutic basal cell carcinoma (BCC) punch biopsies.

OBJECTIVES

The objective of the study was to assess diagnostic accuracy of EVCM versus traditional histopathological examination for diagnosing and subtyping clinically suspicious lesions of BCC in 3-mm fresh and nonfixed punch biopsies.

METHODS

In this prospective monocentric observational study, patients with clinically suspected BCC were consecutively enrolled. Punch biopsies were imaged using EVCM and subsequently processed for standard histologic examination (gold standard). EVCM images were examined by a dermatopathologist blinded to clinical aspect of the lesion and histopathological results. Concordance between the EVCM and histology analysis was calculated with Cohen's kappa (κ) statistic.

RESULTS

Sixty-six patients were recruited, and 106 biopsies were analyzed. EVCM correctly diagnosed 70/73 BCCs and 31/33 non-BCC lesions, corresponding to a sensitivity of 96% and a specificity of 94% (positive predictive value = 97%, negative predictive value = 91%). The EVCM assessment led to over-staging and under-staging of BCC subtypes in 5% and 11% of cases, respectively. It led to over-staging and under-staging of BCC depths in 5% and 15%, respectively. The kappa coefficient for concordance was 0.78 (95% confidence interval [CI]: 0.69-0.88) when considering BCC subtypes and 0.81 (95% CI: 0.72-0.90) when considering BCC depths.

CONCLUSIONS

These results render EVCM as a promising option for "real-time" pretreatment evaluation of clinically suspected BCC lesions. Further larger randomized studies are needed to assess the efficiency of EVCM versus standard care in patients with clinically suspected BCC.

Functional metagenomics reveals differential chitin degradation and utilization features across free-living and host-associated marine microbiomes

BACKGROUND

Chitin ranks as the most abundant polysaccharide in the oceans yet knowledge of shifts in structure and diversity of chitin-degrading communities across marine niches is scarce. Here, we integrate cultivation-dependent and -independent approaches to shed light on the chitin processing potential within the microbiomes of marine sponges, octocorals, sediments, and seawater.

RESULTS

We found that cultivatable host-associated bacteria in the genera Aquimarina, Enterovibrio, Microbulbifer, Pseudoalteromonas, Shewanella, and Vibrio were able to degrade colloidal chitin in vitro. Congruent with enzymatic activity bioassays, genome-wide inspection of cultivated symbionts revealed that Vibrio and Aquimarina species, particularly, possess several endo- and exo-chitinase-encoding genes underlying their ability to cleave the large chitin polymer into oligomers and dimers. Conversely, Alphaproteobacteria species were found to specialize in the utilization of the chitin monomer N-acetylglucosamine more often. Phylogenetic assessments uncovered a high degree of within-genome diversification of multiple, full-length endo-chitinase genes for Aquimarina and Vibrio strains, suggestive of a versatile chitin catabolism aptitude. We then analyzed the abundance distributions of chitin metabolism-related genes across 30 Illumina-sequenced microbial metagenomes and found that the endosymbiotic consortium of Spongia officinalis is enriched in polysaccharide deacetylases, suggesting the ability of the marine sponge microbiome to convert chitin into its deacetylated-and biotechnologically versatile-form chitosan. Instead, the abundance of endo-chitinase and chitin-binding protein-encoding genes in healthy octocorals leveled up with those from the surrounding environment but was found to be depleted in necrotic octocoral tissue. Using cultivation-independent, taxonomic assignments of endo-chitinase encoding genes, we unveiled previously unsuspected richness and divergent structures of chitinolytic communities across host-associated and free-living biotopes, revealing putative roles for uncultivated Gammaproteobacteria and Chloroflexi symbionts in chitin processing within sessile marine invertebrates.

CONCLUSIONS

Our findings suggest that differential chitin degradation pathways, utilization, and turnover dictate the processing of chitin across marine micro-niches and support the hypothesis that inter-species cross-feeding could facilitate the co-existence of chitin utilizers within marine invertebrate microbiomes. We further identified chitin metabolism functions which may serve as indicators of microbiome integrity/dysbiosis in corals and reveal putative novel chitinolytic enzymes in the genus Aquimarina that may find applications in the blue biotechnology sector. Video abstract.

[Management of immune-related toxicities associated with immune checkpoints inhibitors: Data from the multidisciplinary meeting « ToxImmun » in Eastern Occitania]

Immune checkpoint inhibitors (ICIs) can cause numerous and complex immune-related adverse events whose management need a multidisciplinary approach. Herein, we investigated 114 requests, mostly concerning patients suffering from lung cancer, that were submitted to the « ToxImmun » multidisciplinary meeting in Eastern Occitania between December the 17th 2018 and January the 20th 2020. The leading reasons for the request concerned the putative causal link between immunotherapy and immune-toxicity and its management, followed by possible retreatment after temporary withdrawn because of adverse event, and finally the possibility to initiate ICIs in patients with pre-existing autoimmunity. Colitis, hepatitis and myocarditis were the most frequent immune-related adverse events (IRAEs), both all grade and grade 3-4. Sicca syndrome (with or without Sjogren criteria) was also frequent (26% of cases) and seems to be associated with severe toxicity and multi-toxicity. The mean time to first IRAE was 3.8 months, a time shortened with the use of anti-PD-L1 agents or ICI combination. A majority of requests came from initial evaluation by the internist confirming the early and main role of this specialty in the management of immunotoxicity. Expansion of this regional multidisciplinary meeting, coordinated by internists and medical oncologists, could improve management of immune-related adverse events for the patients' benefits.

Clinical Relevance of Liquid Biopsy in Melanoma and Merkel Cell Carcinoma

Melanoma and Merkel cell carcinoma are two aggressive skin malignancies with high disease-related mortality and increasing incidence rates. Currently, invasive tumor tissue biopsy is the gold standard for their diagnosis, and no reliable easily accessible biomarker is available to monitor patients with melanoma or Merkel cell carcinoma during the disease course. In these last years, liquid biopsy has emerged as a candidate approach to overcome this limit and to identify biomarkers for early cancer diagnosis, prognosis, therapeutic response prediction, and patient follow-up. Liquid biopsy is a blood-based non-invasive procedure that allows the sequential analysis of circulating tumor cells, circulating cell-free and tumor DNA, and extracellular vesicles. These innovative biosources show similar features as the primary tumor from where they originated and represent an alternative to invasive solid tumor biopsy. In this review, the biology and technical challenges linked to the detection and analysis of the different circulating candidate biomarkers for melanoma and Merkel cell carcinoma are discussed as well as their clinical relevance.

Psoriatic epidermis is associated with upregulation of CDK2 and inhibition of CDK4 activity

BACKGROUND

The cyclin-dependent kinases (CDKs) CDK2 and CDK4 are involved in regulation of cell-cycle progression, and psoriasis is characterized by hyperproliferation of basal epidermal cells. CDK inhibitory proteins (CKIs) such as p16^{INK 4A} (p16) bind CDK4/6 kinases and prevent their interaction with D-type cyclins. CKIs such as p21^Cip1 (p21) and p27^Kip1 (p27) associate with CDK-cyclin complexes and prevent their activation.

OBJECTIVES

To gain insight into the molecular implication of CDK2 and CDK4 kinases in psoriasis, we sought to characterize expression of these kinases and associated cyclins, as well as of CKIs, and addressed the status of CDK2 and CDK4 activity in human psoriatic epidermis.

METHODS

A cohort of 24 patients with psoriasis participated in the study. Biopsies were removed from a chronic plaque and from nonlesional skin. CDK2, CDK4, cyclin D1, cyclin E and CKI protein expression was assessed by immunoblotting, immunohistochemistry and immunofluorescence. CDK4 and CDK2 mRNA expression was determined by real-time polymerase chain reaction. Specific kinase activities of CDK2 and CDK4 were evaluated using fluorescent peptide biosensors.

RESULTS

CDK2-cyclin E expression and activity were significantly increased in psoriatic epidermis compared with uninvolved adjacent skin. In contrast, CDK4-cyclin D1 activity was inhibited, although its expression was increased in psoriatic epidermis and its transcription slightly inhibited. p27 expression was reduced, while p16 and p21 expression was induced in psoriatic epidermis.

CONCLUSIONS

Epidermal CDK2 activity is increased in psoriatic epidermis while CDK4 activity is completely inhibited. These alterations are not associated with changes in CDK transcription and instead involve post-translational control mediated by decreased expression of p27 and p16 overexpression, respectively. What's already known about this topic? Cyclin-dependent kinases (CDKs) are involved in cell-cycle progression. The levels of cyclin partners and CDK inhibitors regulate their activity. Psoriasis is a chronic T-cell-driven inflammatory skin disease characterized by hyperproliferation of basal epidermal cells. What does this study add? Thanks to fluorescent peptide biosensors, this study demonstrates that epidermal CDK2 activity is increased in psoriatic epidermis while CDK4 activity is completely inhibited. These alterations involve post-translational control mediated by decreased expression of p27, and p16 overexpression, respectively. What is the translational message? CDK2 and CDK4 are involved in regulation of cell-cycle progression, and psoriasis is characterized by hyperproliferation of basal epidermal cells. Epidermal CDK2 activity is increased in psoriatic epidermis while CDK4 activity is completely inhibited. These alterations are not associated with changes in CDK transcription and instead involve post-translational control mediated by decreased expression of p27 and p16 overexpression, respectively. Pharmacological modulation of CDK2 and CDK4 may constitute a promising therapeutic strategy.

S100-EPISPOT: A New Tool to Detect Viable Circulating Melanoma Cells

Metastatic melanoma is one of the most aggressive and drug-resistant cancers with very poor overall survival. Circulating melanoma cells (CMCs) were first described in 1991. However, there is no general consensus on the clinical utility of CMC detection, largely due to conflicting results linked to the use of heterogeneous patient populations and different detection methods. Here, we developed a new EPithelial ImmunoSPOT (EPISPOT) assay to detect viable CMCs based on their secretion of the S100 protein (S100-EPISPOT). Then, we compared the results obtained with the S100-EPISPOT assay and the CellSearch^® CMC kit using blood samples from a homogeneous population of patients with metastatic melanoma. We found that S100-EPISPOT sensitivity was significantly higher than that of CellSearch^®. Specifically, the percentage of patients with ≥2 CMCs was significantly higher using S100-EPISPOT than CellSearch^® (48% and 21%, respectively; p = 0.0114). Concerning CMC prognostic value, only the CellSearch^® results showed a significant association with overall survival (p = 0.006). However, due to the higher sensitivity of the new S100-EPISPOT assay, it would be interesting to determine whether this functional test could be used in patients with non-metastatic melanoma for the early detection of tumor relapse and for monitoring the treatment response.

Performances of an Artificial Reagent for the One-stage Factor IX Assay

A mixture of adsorbed normal human plasma and chicken plasma was prepared as reagent for factor IX measurement using a one-stage method. The substrate was found to be specific for factor IX. Its performances tested on samples displaying factor IX activity ranging from <l%–2,500% compared favorably with those obtained when using the plasma of severe haemophilia B patients as substrate.

The Cdc42/Rac1 regulator CdGAP is a novel E-cadherin transcriptional co-repressor with Zeb2 in breast cancer

The loss of E-cadherin causes dysfunction of the cell-cell junction machinery, which is an initial step in epithelial-to-mesenchymal transition (EMT), facilitating cancer cell invasion and the formation of metastases. A set of transcriptional repressors of E-cadherin (CDH1) gene expression, including Snail1, Snail2 and Zeb2 mediate E-cadherin downregulation in breast cancer. However, the molecular mechanisms underlying the control of E-cadherin expression in breast cancer progression remain largely unknown. Here, by using global gene expression approaches, we uncover a novel function for Cdc42 GTPase-activating protein (CdGAP) in the regulation of expression of genes involved in EMT. We found that CdGAP used its proline-rich domain to form a functional complex with Zeb2 to mediate the repression of E-cadherin expression in ErbB2-transformed breast cancer cells. Conversely, knockdown of CdGAP expression led to a decrease of the transcriptional repressors Snail1 and Zeb2, and this correlated with an increase in E-cadherin levels, restoration of cell-cell junctions, and epithelial-like morphological changes. In vivo, loss of CdGAP in ErbB2-transformed breast cancer cells impaired tumor growth and suppressed metastasis to lungs. Finally, CdGAP was highly expressed in basal-type breast cancer cells, and its strong expression correlated with poor prognosis in breast cancer patients. Together, these data support a previously unknown nuclear function for CdGAP where it cooperates in a GAP-independent manner with transcriptional repressors to function as a critical modulator of breast cancer through repression of E-cadherin transcription. Targeting Zeb2-CdGAP interactions may represent novel therapeutic opportunities for breast cancer treatment.

Fluorescent peptide biosensor for monitoring CDK4/cyclin D kinase activity in melanoma cell extracts, mouse xenografts and skin biopsies

Melanoma constitutes the most aggressive form of skin cancer, which further metastasizes into a deadly form of cancer. The p16(INK4a)-Cyclin D-CDK4/6-pRb pathway is dysregulated in 90% of melanomas. CDK4/Cyclin D kinase hyperactivation, associated with mutation of CDK4, amplification of Cyclin D or loss of p16(INK4a) leads to increased risk of developing melanoma. This kinase therefore constitutes a key biomarker in melanoma and an emerging pharmacological target, however there are no tools enabling direct detection or quantification of its activity. Here we report on the design and application of a fluorescent peptide biosensor to quantify CDK4 activity in melanoma cell extracts, skin biopsies and melanoma xenografts. This biosensor provides sensitive means of comparing CDK4 activity between different melanoma cell lines and further responds to CDK4 downregulation by siRNA or small-molecule inhibitors. By affording means of monitoring CDK4 hyperactivity consequent to cancer-associated molecular alterations in upstream signaling pathways that converge upon this kinase, this biosensor offers an alternative to immunological identification of melanoma-specific biomarkers, thereby constituting an attractive tool for diagnostic purposes, providing complementary functional information to histological analysis, of particular utility for detection of melanoma onset in precancerous lesions. This is indeed the first fluorescent peptide biosensor which has been successfully implemented to monitor kinase activity in skin samples and melanoma tumour xenografts. Moreover by enabling to monitor response to CDK4 inhibitors, this biosensor constitutes an attractive companion assay to identify compounds of therapeutic relevance for melanoma.

[Type I interferonopathies]

Type I interferonopathies are a group of Mendelian disorders characterized by a common physiopathology: the up-regulation of type I interferons. To date, interferonopathies include Aicardi-Goutières syndrome, familial chilblain lupus, spondyenchondromatosis, PRoteasome-associated auto-inflammatory syndrome (PRAAS) and Singleton-Merten syndrome. These diseases present phenotypic overlap including cutaneous features like chilblain lupus, that can be inaugural or present within the first months of life. This novel set of inborn errors of immunity is evolving rapidly, with recognition of new diseases and genes. Recent and improved understanding of the physiopathology of overexpression of type I interferons has allowed the development of targeted therapies, currently being evaluated, like Janus-kinases or reverse transcriptase inhibitors.

AMPK/HuR-Driven IL-20 Post-Transcriptional Regulation in Psoriatic Skin

IL-20 is involved in the development of skin psoriasis. The molecular mechanisms underlying IL-20 overexpression in psoriatic epidermis remain to be elucidated. We showed that IL-20 was primarily upregulated in psoriatic skin at the post-transcriptional level. The RNA-binding protein HuR relocalized to the cytoplasm of keratinocytes (KCs) of psoriatic patients, suggesting that it stabilizes numerous transcripts, as observed in the human KC cell lines used to assess IL-20 mRNA. We characterized epidermal HuR RNA targets in psoriatic skin using ribonucleoprotein immunoprecipitation analyzed via high-throughput sequencing. Numerous transcripts that are upregulated in psoriasis were targeted by HuR, supporting the participation of HuR in pathogenic processes such as morphological changes, innate and adaptive immune responses, and metabolic inflammatory responses. Finally, we identified the metabolic sensor AMP-activated protein kinase (AMPK) as being responsible for HuR cytoplasmic relocalization because its activity was severely impaired in human psoriatic epidermis, and in vivo drug-mediated AMPK inhibition in mouse epidermis promoted HuR cytoplasmic localization, IL-20 overproduction, acanthosis, and hyperkeratosis. These results provide insights into the molecular links between metabolism and post-transcriptional networks during chronic inflammation.

Gekoppelte periodische Elektrodenvorgänge

Es wird gezeigt, wie periodisch reagierende Elektroden in analoger Weise wie elektrische Schwingungskreise miteinander gekoppelt werden können. Die dabei auftretenden Kopplungsschwingungen zeichnen sich durch eine ausgeprägte Tendenz zur Synchronisierung aus, die auch dann noch angestrebt wird, wenn diese im Falle zu geringer Kopplungsfestigkeit aus energetischen Gründen nicht mehr vollständig möglich ist. Es entstehen auf diese Weise mannigfaltige Synchronisierungsformen, die eine auffallende Übereinstimmung mit biologischen rhythmischen Erscheinungen zeigen. Diese Analogie beruht auf der Kippschwingungsnatur beider Schwingungsphänomene. So stimmen die hier an elektrochemischen Systemen erhaltenen Oszillogramme auch weitgehend mit denen überein, die B. van der Pol und U. van der Mark sowie A. Bethe bei Modellversuchen zur biologischen Rhythmizität mit gekoppelten elektrischen Kippschwingungskreisen gefunden haben.

[Multiple primary cutaneous plasmacytoma]

BACKGROUND

Primary cutaneous plasmacytoma is a rare form of cutaneous B-cell lymphoma.

PATIENTS AND METHODS

A 51 year-old male with an unremarkable history gradually presented erythematous papulonodular lesions that had appeared gradually over the whole body throughout a two-year period and showing histologic and immunohistochemical features of cutaneous plasmacytoma. Staging investigations confirmed the primary character of the disease, and because of this and the absence of functional impairment, we opted for therapeutic abstention. No progression was noted after 4 years of regular monitoring.

DISCUSSION

Primary cutaneous plasmacytoma (PCP) is characterized by clonal proliferation of plasma cells in skin. Multiple PCPs are extremely rare and to date have been treated in most cases by chemotherapy, either with or without radiotherapy. The prognosis is poor, with 2-year survival of only 25%. The present case is original, being the only one to our knowledge in which therapeutic abstention was followed by a lack of progression after 4 years of regular follow-up. Consequently, certain indolent forms of PCP do not warrant automatic institution of chemotherapy.

Nevus anemicus in neurofibromatosis type 1: a potential new diagnostic criterion

BACKGROUND

Children with multiple café-au-lait macules (CALMs) may be followed for years before a second National Institutes of Health clinical criterion of neurofibromatosis type 1 (NF1) develops to confirm the diagnosis.

OBJECTIVE

We sought to assess the prevalence of nevus anemicus (NA) in NF1 and its association with neuro-ophthalmologic complications.

METHODS

This was a prospective multicenter case-control study of 210 consecutive patients with multiple CALMs. Patients with NF1 were matched for age, sex, and center with control subjects. We documented the number, location, and morphologic appearance of NA; dermatologic features of NF1; magnetic resonance imaging results; and family history.

RESULTS

In all, 77 (51%) patients with NF1 had NA compared with 6 (2%) control subjects. NA was not detected in 26 patients with other genodermatoses associated with CALMs. Patients with NF1 and NA were younger than those without NA (median age: 17 years) (P = .002). NA was mostly localized to the upper anterior aspect of the chest. NA was not significantly linked with other clinical manifestations of NF1, including optic glioma and unidentified bright objects.

LIMITATIONS

A potential referral bias associated with tertiary care centers is a limitation.

CONCLUSIONS

NA appears to have a high prevalence and specificity in NF1 and might serve as a marker for NF1 in children with multiple CALMs.