Tumor Cell-Associated IL-1α Affects Breast Cancer Progression and Metastasis in Mice through Manipulation of the Tumor Immune Microenvironment.

IL-1α is a dual function cytokine that affects inflammatory and immune responses and plays a pivotal role in cancer. The effects of intracellular IL-1α on the development of triple negative breast cancer (TNBC) in mice were assessed using the CRISPR/Cas9 system to suppress IL-1α expression in 4T1 breast cancer cells. Knockout of IL-1α in 4T1 cells modified expression of multiple genes, including downregulation of cytokines and chemokines involved in the recruitment of tumor-associated pro-inflammatory cells. Orthotopical injection of IL-1α knockout (KO) 4T1 cells into BALB/c mice led to a significant decrease in local tumor growth and lung metastases, compared to injection of wild-type 4T1 (4T1/WT) cells. Neutrophils and myeloid-derived suppressor cells were abundant in tumors developing after injection of 4T1/WT cells, whereas more antigen-presenting cells were observed in the tumor microenvironment after injection of IL-1α KO 4T1 cells. This switch correlated with increased infiltration of CD3+CD8+ and NKp46+cells. Engraftment of IL-1α knockout 4T1 cells into immunodeficient NOD.SCID mice resulted in more rapid tumor growth, with increased lung metastasis in comparison to engraftment of 4T1/WT cells. Our results suggest that tumor-associated IL-1α is involved in TNBC progression in mice by modulating the interplay between immunosuppressive pro-inflammatory cells vs. antigen-presenting and cytotoxic cells.

Heterozygous THBS2 pathogenic variant causes Ehlers-Danlos syndrome with prominent vascular features in humans and mice.

Ehlers-Danlos syndromes (EDS) are a group of connective tissue disorders caused by mutations in collagen and collagen-interacting genes. We delineate a novel form of EDS with vascular features through clinical and histopathological phenotyping and genetic studies of a three-generation pedigree, displaying an apparently autosomal dominant phenotype of joint hypermobility and frequent joint dislocations, atrophic scarring, prolonged bleeding time and age-related aortic dilatation and rupture. Coagulation tests as well as platelet counts and function were normal. Reticular dermis displayed highly disorganized collagen fibers and transmission electron microscopy (TEM) revealed abnormally shaped fibroblasts and endothelial cells, with high amount and irregular shape of extracellular matrix (ECM) substance, especially near blood vessels. Genetic analysis unraveled a heterozygous mutation in THBS2 (NM_003247.5:c.2686T>C, p.Cys896Arg). We generated CRISPR/Cas9 knock-in (KI) mice, bearing the heterozygous human mutation in the mouse ortholog. The KI mice demonstrated phenotypic traits correlating with those observed in the human subjects, as evidenced by morphologic, histologic, and TEM analyses, in conjunction with bleeding time assays. Our findings delineate a novel form of human EDS with classical-like elements combined with vascular features, caused by a heterozygous THBS2 missense mutation. We further demonstrate a similar phenotype in heterozygous THBS2Cys896Arg KI mice, in line with previous studies in Thbs2 homozygous null-mutant mice. Notably, THBS2 encodes Thrombospondin-2, a secreted homotrimeric matricellular protein that directly binds the ECM-shaping Matrix Metalloproteinase 2 (MMP2), mediating its clearance. THBS2 loss-of-function attenuates MMP2 clearance, enhancing MMP2-mediated proteoglycan cleavage, causing ECM abnormalities similar to those seen in the human and mouse disease we describe.

ZNF750 Regulates Skin Barrier Function by Driving Cornified Envelope and Lipid Processing Pathways.

The epidermis is a constantly renewing stratified epithelial tissue that provides essential protective barrier functions. The major barrier is located at the outermost layers of the epidermis, formed by terminally differentiated keratinocytes reinforced by proteins of their cornified envelope and sequestered intercellular lipids. Disruptions to epidermal differentiation characterize various skin disorders. ZNF750 is an epithelial transcription factor essential for in vitro keratinocyte differentiation, whose truncating mutation in humans causes autosomal dominant psoriasis-like skin disease. In this study, we utilized an epidermal-specific Znf750 conditional knockout mouse model to uncover the role ZNF750 plays in epidermal development. We show that deletion of Znf750 in the developing skin does not block epidermal differentiation completely, suggesting in vivo compensatory feedback mechanisms, although it does result in impaired barrier function and perinatal lethality. Molecular dissection revealed ultrastructural defects in the differentiated layers of the epidermis, accompanied by alterations in the expression of ZNF750-dependent genes encoding key cornified envelope precursor proteins and lipid-processing enzymes, including gene subsets known to be mutated in human skin diseases involving impaired barrier function. Together, our findings provide molecular insights into the pathogenesis of human skin disease by linking ZNF750 to a subset of epidermal differentiation genes involved in barrier formation pathways.

CLDN1 Arg81His founder variant causes ichthyosis, leukocyte vacuoles, alopecia, and sclerosing cholangitis (ILVASC) syndrome in Moroccan Jews.

Neonatal ichthyosis and sclerosing cholangitis syndrome (NISCH), also known as ichthyosis, leukocyte vacuoles, alopecia, and sclerosing cholangitis (ILVASC), is an extremely rare disease of autosomal recessive inheritance, resulting from loss of function of the tight junction protein claudin-1. Its clinical presentation is highly variable, and is characterized by liver and ectodermal involvement. Although most ILVASC cases described to date were attributed to homozygous truncating variants in CLDN1, a single missense variant CLDN1 p.Arg81His, associated with isolated skin ichthyosis phenotype, has been recently reported in a family of Moroccan Jewish descent. We now describe seven patients with ILVASC, originating from four non consanguineous families of North African Jewish ancestry (including one previously reported family), harboring CLDN1 p.Arg81His variant, and broaden the phenotypic spectrum attributed to this variant to include teeth, hair, and liver/bile duct involvement, characteristic of ILVASC. Furthermore, we provide additional evidence for pathogenicity of the CLDN1 p.Arg81His variant by transmission electron microscopy of the affected skin, revealing distorted tight junction architecture, and show through haplotype analysis in the vicinity of the CLDN1 gene, that this variant represents a founder variant in Jews of Moroccan descent with an estimated carrier frequency of 1:220.

The Humoral Response of Patients With Cancer to Breakthrough COVID-19 Infection or the Fourth BNT162b2 Vaccine Dose.

Since January 2022 in Israel, high-risk populations with underlying health conditions were advised to receive a fourth dose of the BNT162b2 vaccine (Pfizer-BioNTech) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We monitored vaccine-induced immunity among oncology patients undergoing systemic anti-cancer therapy before and after the 4th-BNT162b2-dose. Three groups of patients were included in the study: those who received 3rd-BNT162b2-dose and had no breakthrough infection (control), those who received 3rd-BNT162b2-dose and had the breakthrough infection, and those who received the 4th-BNT162b2-dose and had no breakthrough infection. Anti-SARS-CoV-2 immunoglobulin-G (IgG) levels of the control group exhibited a rapid decrease over time, whereas IgG titers of patients with breakthrough-infections or patients vaccinated with the 4th-BNT162b2-dose were considerably elevated, consistent with the capacity of the second booster to induce anti-SARS-CoV-2 IgG levels. Additionally, oncology patients' humoral immune response was significantly greater after breakthrough-infection than in response to the 4th dose of BNT162b2.

X-linked C1GALT1C1 mutation causes atypical hemolytic uremic syndrome.

Hemolytic-uremic syndrome (HUS), mostly secondary to infectious diseases, is a common cause of acute kidney injury in children. It is characterized by progressive acute kidney failure due to severe thrombotic microangiopathy, associated with nonimmune, Coombs-negative hemolytic anemia and thrombocytopenia. HUS is caused mostly by Shiga toxin-producing E. Coli, and to a lesser extent by Streptococcus pneumonia. In Streptococcus pneumonia HUS (pHUS), bacterial neuraminidase A exposes masked O-glycan sugar residues on erythrocytes, known as the T antigen, triggering a complement cascade causing thrombotic microangiopathy. Atypical HUS (aHUS) is a life-threatening genetic form of the disease, whose molecular mechanism is only partly understood. Through genetic studies, we demonstrate a novel X-linked form of aHUS that is caused by a de-novo missense mutation in C1GALT1C1:c.266 C > T,p.(T89I), encoding a T-synthase chaperone essential for the proper formation and incorporation of the T antigen on erythrocytes. We demonstrate the presence of exposed T antigen on the surface of mutant erythrocytes, causing aHUS in a mechanism similar to that suggested in pHUS. Our findings suggest that both aHUS caused by mutated C1GALT1C1 and pHUS are mediated by the lectin-complement-pathway, not comprehensively studied in aHUS. We thus delineate a shared molecular basis of aHUS and pHUS, highlighting possible therapeutic opportunities.

The SSSS scheme: a method for calculating multiple scattering of electromagnetic radiation by a collection of sparsely spaced spherical scatterers of Mie-scattering size based on first principles.

We present a method for calculating multiple scattering of electromagnetic radiation by a collection of sparsely spaced spherical scatterers (SSSS) of Mie-scattering size based on first principles rather than radiative transfer theory. In this respect, our methodology is conceptually similar to the superposition T-matrix method. However, our implementation, which we call the SSSS scheme, differs in a number of respects. Overall, the SSSS scheme is simpler, it is better suited numerically to sparse spacing, and the computer memory required is only linearly dependent on the total number of scatterers. We suggest that the SSSS scheme would be particularly useful for examining the effects of different spatial configurations of drops within water clouds in Earth's atmosphere and would also be useful in other fields of research in which the exact configuration of a collection of sparsely spaced Mie-sized scatterers is important.

Histone Mono-Ubiquitination in Transcriptional Regulation and Its Mark on Life: Emerging Roles in Tissue Development and Disease.

Epigenetic regulation plays an essential role in driving precise transcriptional programs during development and homeostasis. Among epigenetic mechanisms, histone mono-ubiquitination has emerged as an important post-transcriptional modification. Two major histone mono-ubiquitination events are the mono-ubiquitination of histone H2A at lysine 119 (H2AK119ub), placed by Polycomb repressive complex 1 (PRC1), and histone H2B lysine 120 mono-ubiquitination (H2BK120ub), placed by the heteromeric RNF20/RNF40 complex. Both of these events play fundamental roles in shaping the chromatin epigenetic landscape and cellular identity. In this review we summarize the current understandings of molecular concepts behind histone mono-ubiquitination, focusing on their recently identified roles in tissue development and pathologies.

The Effectiveness and Safety of Medical Cannabis for Treating Cancer Related Symptoms in Oncology Patients.

The use of medical cannabis (MC) to treat cancer-related symptoms is rising. However, there is a lack of long-term trials to assess the benefits and safety of MC treatment in this population. In this work, we followed up prospectively and longitudinally on the effectiveness and safety of MC treatment. Oncology patients reported on multiple symptoms before and after MC treatment initiation at one-, three-, and 6-month follow-ups. Oncologists reported on the patients' disease characteristics. Intention-to-treat models were used to assess changes in outcomes from baseline. MC treatment was initiated by 324 patients and 212, 158 and 126 reported at follow-ups. Most outcome measures improved significantly during MC treatment for most patients (p < 0.005). Specifically, at 6 months, total cancer symptoms burden declined from baseline by a median of 18%, from 122 (82-157) at baseline to 89 (45-138) at endpoint (-18.98; 95%CI= -26.95 to -11.00; p < 0.001). Reported adverse effects were common but mostly non-serious and remained stable during MC treatment. The results of this study suggest that MC treatment is generally safe for oncology patients and can potentially reduce the burden of associated symptoms with no serious MC-related adverse effects.

Global and Local Trends Affecting the Experience of US and UK Healthcare Professionals during COVID-19: Twitter Text Analysis.

BACKGROUND: Healthcare professionals (HCPs) are on the frontline of fighting the COVID-19 pandemic. Recent reports have indicated that, in addition to facing an increased risk of being infected by the virus, HCPs face an increased risk of suffering from emotional difficulties associated with the pandemic. Therefore, understanding HCPs' experiences and emotional displays during emergencies is a critical aspect of increasing the surge capacity of communities and nations. METHODS: In this study, we analyzed posts published by HCPs on Twitter to infer the content of discourse and emotions of the HCPs in the United States (US) and United Kingdom (UK), before and during the COVID-19 pandemic. The tweets of 25,207 users were analyzed using natural language processing (NLP). RESULTS: Our results indicate that HCPs in the two countries experienced common health, social, and political issues related to the pandemic, reflected in their discussion topics, sentiments, and emotional display. However, the experiences of HCPs in the two countries are also subject to local socio-political trends, as well as cultural norms regarding emotional display. CONCLUSIONS: Our results support the potential of utilizing Twitter discourse to monitor and predict public health responses in emergencies.

Correction: Bar-Sela et al. Cannabis Consumption Used by Cancer Patients during Immunotherapy Correlates with Poor Clinical Outcome. Cancers 2020, 12, 2447.

In the original article [...].

MEK1/2 inhibition transiently alters the tumor immune microenvironment to enhance immunotherapy efficacy against head and neck cancer.

BACKGROUND: Although the mitogen-activated protein kinases (MAPK) pathway is hyperactive in head and neck cancer (HNC), inhibition of MEK1/2 in HNC patients has not shown clinically meaningful activity. Therefore, we aimed to characterize the effect of MEK1/2 inhibition on the tumor microenvironment (TME) of MAPK-driven HNC, elucidate tumor-host interaction mechanisms facilitating immune escape on treatment, and apply rationale-based therapy combination immunotherapy and MEK1/2 inhibitor to induce tumor clearance. METHODS: Mouse syngeneic tumors and xenografts experiments were used to analyze tumor growth in vivo. Single-cell cytometry by time of flight, flow cytometry, and tissue stainings were used to profile the TME in response to trametinib (MEK1/2 inhibitor). Co-culture of myeloid-derived suppressor cells (MDSC) with CD8+ T cells was used to measure immune suppression. Overexpression of colony-stimulating factor-1 (CSF-1) in tumor cells was used to show the effect of tumor-derived CSF-1 on sensitivity to trametinib and anti-programmed death- 1 (αPD-1) in mice. In HNC patients, the ratio between CSF-1 and CD8A was measured to test the association with clinical benefit to αPD-1 and αPD-L1 treatment. RESULTS: Using preclinical HNC models, we demonstrated that treatment with trametinib delays HNC initiation and progression by reducing tumor cell proliferation and enhancing the antitumor immunity of CD8+ T cells. Activation of CD8+ T cells by supplementation with αPD-1 antibody eliminated tumors and induced an immune memory in the cured mice. Mechanistically, an early response to trametinib treatment sensitized tumors to αPD-1-supplementation by attenuating the expression of tumor-derived CSF-1, which reduced the abundance of two CSF-1R+CD11c+ MDSC populations in the TME. In contrast, prolonged treatment with trametinib abolished the antitumor activity of αPD-1, because tumor cells undergoing the epithelial to mesenchymal transition in response to trametinib restored CSF-1 expression and recreated an immune-suppressive TME. CONCLUSION: Our findings provide the rationale for testing the trametinib/αPD-1 combination in HNC and highlight the importance of sensitizing tumors to αPD-1 by using MEK1/2 to interfere with the tumor-host interaction. Moreover, we describe the concept that treatment of cancer with a targeted therapy transiently induces an immune-active microenvironment, and supplementation of immunotherapy during this time further activates the antitumor machinery to cause tumor elimination.

"The Two Sides of the Same Coin"-Medical Cannabis, Cannabinoids and Immunity: Pros and Cons Explained.

Cannabis, as a natural medicinal remedy, has long been used for palliative treatment to alleviate the side effects caused by diseases. Cannabis-based products isolated from plant extracts exhibit potent immunoregulatory properties, reducing chronic inflammatory processes and providing much needed pain relief. They are a proven effective solution for treatment-based side effects, easing the resulting symptoms of the disease. However, we discuss the fact that cannabis use may promote the progression of a range of malignancies, interfere with anti-cancer immunotherapy, or increase susceptibility to viral infections and transmission. Most cannabis preparations or isolated active components cause an overall potent immunosuppressive impact among users, posing a considerable hazard to patients with suppressed or compromised immune systems. In this review, current knowledge and perceptions of cannabis or cannabinoids and their impact on various immune-system components will be discussed as the "two sides of the same coin" or "double-edged sword", referring to something that can have both favorable and unfavorable consequences. We propose that much is still unknown about adverse reactions to its use, and its integration with medical treatment should be conducted cautiously with consideration of the individual patient, effector cells, microenvironment, and the immune system.

Polycomb Repressive Complex(es) and Their Role in Adult Stem Cells.

Populations of resident stem cells (SCs) are responsible for maintaining, repairing, and regenerating adult tissues. In addition to having the capacity to generate all the differentiated cell types of the tissue, adult SCs undergo long periods of quiescence within the niche to maintain themselves. The process of SC renewal and differentiation is tightly regulated for proper tissue regeneration throughout an organisms' lifetime. Epigenetic regulators, such as the polycomb group (PcG) of proteins have been implicated in modulating gene expression in adult SCs to maintain homeostatic and regenerative balances in adult tissues. In this review, we summarize the recent findings that elucidate the composition and function of the polycomb repressive complex machinery and highlight their role in diverse adult stem cell compartments.

The State of Mind of Health Care Professionals in Light of the COVID-19 Pandemic: Text Analysis Study of Twitter Discourses.

BACKGROUND: The COVID-19 pandemic has affected populations worldwide, with extreme health, economic, social, and political implications. Health care professionals (HCPs) are at the core of pandemic response and are among the most crucial factors in maintaining coping capacities. Yet, they are also vulnerable to mental health effects caused by managing a long-lasting emergency with a lack of resources and under complicated personal concerns. However, there are a lack of longitudinal studies that investigate the HCP population. OBJECTIVE: The aim of this study was to analyze the state of mind of HCPs as expressed in online discussions published on Twitter in light of the COVID-19 pandemic, from the onset of the pandemic until the end of 2020. METHODS: The population for this study was selected from followers of a few hundred Twitter accounts of health care organizations and common HCP points of interest. We used active learning, a process that iteratively uses machine learning and manual data labeling, to select the large-scale population of Twitter accounts maintained by English-speaking HCPs, focusing on individuals rather than official organizations. We analyzed the topics and emotions in their discourses during 2020. The topic distributions were obtained using the latent Dirichlet allocation algorithm. We defined a measure of topic cohesion and described the most cohesive topics. The emotions expressed in tweets during 2020 were compared to those in 2019. Finally, the emotion intensities were cross-correlated with the pandemic waves to explore possible associations between the pandemic development and emotional response. RESULTS: We analyzed the timelines of 53,063 Twitter profiles, 90% of which were maintained by individual HCPs. Professional topics accounted for 44.5% of tweets by HCPs from January 1, 2019, to December 6, 2020. Events such as the pandemic waves, US elections, or the George Floyd case affected the HCPs' discourse. The levels of joy and sadness exceeded their minimal and maximal values from 2019, respectively, 80% of the time (P=.001). Most interestingly, fear preceded the pandemic waves, in terms of the differences in confirmed cases, by 2 weeks with a Spearman correlation coefficient of ρ(47 pairs)=0.340 (P=.03). CONCLUSIONS: Analyses of longitudinal data over the year 2020 revealed that a large fraction of HCP discourse is directly related to professional content, including the increase in the volume of discussions following the pandemic waves. The changes in emotional patterns (ie, decrease in joy and increase in sadness, fear, and disgust) during the year 2020 may indicate the utmost importance in providing emotional support for HCPs to prevent fatigue, burnout, and mental health disorders during the postpandemic period. The increase in fear 2 weeks in advance of pandemic waves indicates that HCPs are in a position, and with adequate qualifications, to anticipate pandemic development, and could serve as a bottom-up pathway for expressing morbidity and clinical situations to health agencies.

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. Genetic ablation of key Polycomb subunits in murine EpSCs, mimicking depletion upon UV exposure, results in an increased number of epidermal melanocytes and subsequent epidermal pigmentation. Genome-wide transcriptional and chromatin studies show that Polycomb regulates the expression of UV-responsive genes and identifies type II collagen (COL2A1) as a critical secreted regulator of melanogenesis and epidermal pigmentation. Together, our findings show how UV exposure induces Polycomb-mediated changes in EpSCs to affect melanocyte behavior and promote epidermal pigmentation.

Epigenetic regulation and signalling pathways in Merkel cell development.

Merkel cells are specialized epithelial cells connected to afferent nerve endings responsible for light-touch sensations, formed at specific locations in touch-sensitive regions of the mammalian skin. Although Merkel cells are descendants of the epidermal lineage, little is known about the mechanisms responsible for the development of these unique mechanosensory cells. Recent studies have highlighted that the Polycomb group (PcG) of proteins play a significant role in spatiotemporal regulation of Merkel cell formation. In addition, several of the major signalling pathways involved in skin development have been shown to regulate Merkel cell development as well. Here, we summarize the current understandings of the role of developmental regulators in Merkel cell formation, including the interplay between the epigenetic machinery and key signalling pathways, and the lineage-specific transcription factors involved in the regulation of Merkel cell development.

Polycomb complexes redundantly maintain epidermal stem cell identity during development.

Polycomb repressive complex 1 (PRC1) and PRC2 are critical epigenetic developmental regulators. PRC1 and PRC2 largely overlap in their genomic binding and cooperate to establish repressive chromatin domains demarcated by H2AK119ub and H3K27me3. However, the functional contribution of each complex to gene repression has been a subject of debate, and understanding of its physiological significance requires further studies. Here, using the developing murine epidermis as a paradigm, we uncovered a previously unappreciated functional redundancy between Polycomb complexes. Coablation of PRC1 and PRC2 in embryonic epidermal progenitors resulted in severe defects in epidermal stratification, a phenotype not observed in the single PRC1-null or PRC2-null epidermis. Molecular dissection indicated a loss of epidermal identity that was coupled to a strong derepression of nonlineage transcription factors, otherwise repressed by either PRC1 or PRC2 in the absence of its counterpart. Ectopic expression of subsets of PRC1/2-repressed nonepidermal transcription factors in wild-type epidermal stem cells was sufficient to suppress epidermal identity genes, highlighting the importance of functional redundancy between PRC1 and PRC2. Altogether, our studies show how PRC1 and PRC2 function as two independent counterparts, thereby providing a repressive safety net that protects and preserves lineage identity.

Medical Cannabis in Oncology: a Valuable Unappreciated Remedy or an Undesirable Risk?

OPINION STATEMENT: The use of the cannabis plant by cancer patients has been rising significantly in the past few years worldwide, primarily driven by public demand. There is an obvious need for more reliable scientific data, pharmacology information, a better understanding of its mode of action, and available clinical evidence supporting its robust use. Physicians must complete a thorough medical assessment, screening for potential drugs, or treatment contraindications before allowing its consumption. In light of the growing popularity of cannabis usage, it is highly essential that, in the near future, the medical community will be able to provide practical recommendations and explicit guidelines, including doses, and that cannabinoid concentrations in the used products are defined regarding its prescription before any medical procedure involving its usage is authorized. Here, we review and describe the favorable outcomes demonstrating the benefits of cannabis as an adjunctive treatment to conventional medicines for chemotherapy-induced nausea, vomiting, and cancer-related pain (primarily refractory chronic or neuropathic pain). Although not yet substantial enough, the treatment of anorexia, insomnia, depression, and anxiety is also seemingly favorable. To date, reports regarding its anti-neoplastic effects or its potent immunosuppressive properties influencing response to immunotherapy are still very conflicting and controversial. Thus, with the current state of evidence, cannabis use is not advisable as initial treatment, as an adjunct or an advanced line of care. In the coming years, we expect that preclinical data and animal models will shift to the clinical arena, and more patients will be recruited for clinical trials, and their reports will advance the field. Thus, physicians should prescribe cannabis only if careful clarification and consideration is provided together with a follow-up response evaluation.