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Abstract Background In humans, two ubiquitously expressed N-myristoyltransferases, NMT1 and NMT2, catalyze myristate transfer to proteins to facilitate membrane targeting and signaling. We investigated the expression of NMTs in numerous cancers and found that NMT2 levels are dysregulated by epigenetic suppression, particularly so in hematologic malignancies. This suggests that pharmacological inhibition of the remaining NMT1 could allow for the selective killing of these cells, sparing normal cells with both NMTs. Methods and results Transcriptomic analysis of 1200 NMT inhibitor (NMTI)-treated cancer cell lines revealed that NMTI sensitivity relates not only to NMT2 loss or NMT1 dependency, but also correlates with a myristoylation inhibition sensitivity signature comprising 54 genes (MISS-54) enriched in hematologic cancers as well as testis, brain, lung, ovary, and colon cancers. Because non-myristoylated proteins are degraded by a glycine-specific N-degron, differential proteomics revealed the major impact of abrogating NMT1 genetically using CRISPR/Cas9 in cancer cells was surprisingly to reduce mitochondrial respiratory complex I proteins rather than cell signaling proteins, some of which were also reduced, albeit to a lesser extent. Cancer cell treatments with the first-in-class NMTI PCLX-001 (zelenirstat), which is undergoing human phase 1/2a trials in advanced lymphoma and solid tumors, recapitulated these effects. The most downregulated myristoylated mitochondrial protein was NDUFAF4, a complex I assembly factor. Knockout of NDUFAF4 or in vitro cell treatment with zelenirstat resulted in loss of complex I, oxidative phosphorylation and respiration, which impacted metabolomes. Conclusions Targeting of both, oxidative phosphorylation and cell signaling partly explains the lethal effects of zelenirstat in select cancer types. While the prognostic value of the sensitivity score MISS-54 remains to be validated in patients, our findings continue to warrant the clinical development of zelenirstat as cancer treatment.

Blocking the mitogen‐activated protein kinase (MAPK) pathway with the MEK1/2 inhibitor trametinib has produced promising results in patients with head and neck squamous cell carcinoma (HNSCC). In the current study, we showed that trametinib treatment leads to overexpression and activation of the epidermal growth factor receptor (EGFR) in HNSCC cell lines and patient‐derived xenografts. Knockdown of EGFR improved trametinib treatment efficacy both in vitro and in vivo. Mechanistically, we demonstrated that trametinib‐induced EGFR overexpression hyperactivates the phosphatidylinositol 3‐kinase (PI3K)/AKT pathway. In vitro, blocking the PI3K pathway with GDC‐0941 (pictilisib), or BYL719 (alpelisib), prevented AKT pathway hyperactivation and enhanced the efficacy of trametinib in a synergistic manner. In vivo, a combination of trametinib and BYL719 showed superior antitumor efficacy vs. the single agents, leading to tumor growth arrest. We confirmed our findings in a syngeneic murine head and neck cancer cell line in vitro and in vivo. Taken together, our findings show that trametinib treatment induces hyperactivation of EGFR/PI3K/AKT; thus, blocking of the EGFR/PI3K pathway is required to improve trametinib efficacy in HNSCC.

Researchers from Université de Sherbrooke have developed a new generation of high efficiency Solar Microreactor to harvest the power of the sun for hydrogen production. This paper presents the architecture, the manufacturing and assembly of this highly integrated system that incorporates in a monolithic block the heat exchangers, catalytic bed and manifolds. Miniaturization of the system provides high heat and mass transfer capabilities and can easily be assembled into a matrix to cover the focal point of any Solar Concentrator. Performances of the Microreactor is first investigated in a laboratory using a high flux solar simulator to plot an efficiency map for a dry methane reforming test under different combinations of reagent mass flow and reaction temperatures. This map is then used as a benchmark for outside tests in order to evaluate the real-condition efficiency of such microreactor matrix. Outside tests were performed with the Université de Sherbrooke’s 100 kW SpaceWatt solar concentrator. It is estimated that the efficiency reaches up to 54 % for the matrix of reactor in real condition operation for an estimated heat flux of 520 kW/m2 compared to the measured value of 71% in laboratory conditions for a single reactor with a heat flux of 800 kW/m2.

In ecology, stable‐isotope ratios are widely used to determine diets of organisms and reconstruct food webs. This is usually done by analyzing the stable‐isotope ratios of nitrogen (δ15N), which increase with increasing trophic level, and those of carbon (δ13C), which correlate with the δ13C value of food source(s) and generally differ between terrestrial and marine food sources. Assimilation of food changes stable‐isotope ratios, resulting in different values between the food source and its consumer. These differences are known as isotope trophic discrimination factors and, if known, can be used to determine from the stable‐isotope ratios in the consumer's tissue what the consumer has been eating. What is often ignored is that discrimination factors can differ between consumer's food sources and also between tissue types. Therefore, we performed a controlled feeding study in red knots Calidris canutus to determine discrimination factors between different food sources and red knot tissues. We kept two groups of red knots in captivity on a stable diet, one group feeding on mudsnails and the other on Trouvit pellets, for several months, during which the birds molted their feathers. We analyzed δ13C and δ15N in both food sources and in five red knot tissues (blood cells, blood plasma and three feather types) and subsequently calculated the isotope discrimination factors. We confirmed that the discrimination factors differed between tissues, and also between diets. Our values deviated from general averages reported in reviews on a wide range of animals/birds, but were very similar to values from previous red knot and dunlin studies. We therefore think that our discrimination factors can be used in future stable isotope studies, not only on red knots, but also on other marine shorebird species and plea for careful consideration of using the right discrimination factors. Keywords: δ13C, δ15N, discrimination factor, red knot, shorebird, stable isotope

Abstract FAT atypical cadherin 1 (FAT1), a transmembrane protein, is frequently mutated in various cancer types and has been described as context-dependent tumor suppressor or oncogene. The FAT1 gene is mutated in 12–16% of T-cell acute leukemia (T-ALL) and aberrantly expressed in about 54% of T-ALL cases contrasted with absent expression in normal T-cells. Here, we characterized FAT1 expression and profiled the methylation status from T-ALL patients. In our T-ALL cohort, 53% of patient samples were FAT1 positive (FAT1pos) compared to only 16% FAT1 positivity in early T-ALL patient samples. Aberrant expression of FAT1 was strongly associated with FAT1 promotor hypomethylation, yet a subset, mainly consisting of TLX1-driven T-ALL patient samples showed methylation-independent high FAT1 expression. Genes correlating with FAT1 expression revealed enrichment in WNT signaling genes representing the most enriched single pathway. FAT1 knockdown or knockout led to impaired proliferation and downregulation of WNT pathway target genes (CCND1, MYC, LEF1), while FAT1 overexpressing conveyed a proliferative advantage. To conclude, we characterized a subtype pattern of FAT1 gene expression in adult T-ALL patients correlating with promotor methylation status. FAT1 dependent proliferation and WNT signaling discloses an impact on deeper understanding of T-ALL leukemogenesis as a fundament for prospective therapeutic strategies.

Abstract Background Intratumoral heterogeneity (ITH) is a hallmark of clear cell renal cell carcinoma (ccRCC) that reflects the trajectory of evolution and influences clinical prognosis. Here, we seek to elucidate how ITH and tumor evolution during immune checkpoint inhibitor (ICI) treatment can lead to therapy resistance. Methods Here, we completed a single-arm pilot study to examine the safety and feasibility of neoadjuvant nivolumab in patients with localized RCC. Primary endpoints were safety and feasibility of neoadjuvant nivolumab. Then, we spatiotemporally profiled the genomic and immunophenotypic characteristics of 29 ccRCC patients, including pre- and post-therapy samples from 17 ICI-treated patients. Deep multi-regional whole-exome and transcriptome sequencing were performed on 29 patients at different time points before and after ICI therapy. T cell repertoire was also monitored from tissue and peripheral blood collected from a subset of patients to study T cell clonal expansion during ICI therapy. Results Angiogenesis, lymphocytic infiltration, and myeloid infiltration varied significantly across regions of the same patient, potentially confounding their utility as biomarkers of ICI response. Elevated ITH associated with a constellation of both genomic features (HLA LOH, CDKN2A/B loss) and microenvironmental features, including elevated myeloid expression, reduced peripheral T cell receptor (TCR) diversity, and putative neoantigen depletion. Hypothesizing that ITH may itself play a role in shaping ICI response, we derived a transcriptomic signature associated with neoantigen depletion that strongly associated with response to ICI and targeted therapy treatment in several independent clinical trial cohorts. Conclusions These results argue that genetic and immune heterogeneity jointly co-evolve and influence response to ICI in ccRCC. Our findings have implications for future biomarker development for ICI response across ccRCC and other solid tumors and highlight important features of tumor evolution under ICI treatment. Trial registration The study was registered on ClinicalTrial.gov (NCT02595918) on November 4, 2015.

BackgroundDue to the expanding role of immune checkpoint inhibition in the treatment of head and neck squamous cell carcinoma, understanding immunological processes in the tumor microevironment (TME) has strong translational importance. Though analytical methods for a comprehensive analysis of the immunological TME have constantly improved and expanded over the past years the prognostic relevance of immune cell composition in head and neck cancer TME largely remains ambiguous with most studies focusing on one or a small subset of immune cells.MethodsThe overall survival (OS) of the TCGA-HNSC patient cohort comprising 513 head and neck cancer patients was correlated with a total of 29 different immune metrics including a wide spectrum of immune cell subpopulations as well as immune checkpoint receptors and cytokines using RNAseq based immune deconvolution analyses. The most significant predictors of survival among these 29 immune metrics were validated on a separate HNSCC patient cohort (n=101) using immunohistochemistry: CD3, CD20+CXCR5, CD4+CXCR5, Foxp3 and CD68.ResultsOverall immune infiltration irrespective of immune cell composition showed no significant correlation with the patients’ overall survival in the TCGA-HNSC cohort. However, when focusing on different immune cell subpopulations, naïve B cells (p=0.0006), follicular T-helper cells (p

Abstract The effects of cytokine and protein stabilizing carriers, such as serum albumin, on tumor response to immune checkpoint blockade (ICB) is not well understood. By examining 1714 patients across 16 cancer types, we found that high pretreatment serum albumin level predicts favorable tumor radiographic response following ICB treatment in a dose-dependent fashion. Serum albumin is a candidate biomarker that can be combined with tumor mutational burden (TMB) for additional predictive capacity, and the tumor response rate to ICB was ~49% in the albumin-high/TMB-high group.

Patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) have limited treatment options, particularly if they are transplantation or chimeric antigen receptor (CAR) T-cell ineligible, and novel therapeutics are needed. An 86-year-old woman with relapsed DLBCL received a novel, first-in-class small molecule inhibitor of N-myristoyltransferase (NMT) as the initial patient on a phase I dose escalation trial. Daily oral administration of 20 mg PCLX-001 tablets produced a pharmacokinetic profile suitable for single daily dosing: rapid oral absorption, followed by an apparent elimination half-life of 16 h, without systemic accumulation of drug by day 15. Pharmacodynamic tests showed no clear change in NMT1 and NMT2 levels or selected NMT substrate Lyn and HGAL protein levels in normal circulating blood mononuclear cells, suggesting a higher dose will be required for normal tissue toxicity. The patient did not experience any dose-limiting toxicities but had disease progression after 28 days of study therapy. Dose escalation continues in other patients in this first-in-human study of a new class of anticancer drug. We conclude that PCLX-001 oral monotherapy has suitable pharmacokinetic parameters for dose escalation, and that higher doses are required to achieve pharmacodynamic evidence of on-target activity in normal tissues. The current protocol is appropriately designed to achieve these ends, and the study proceeds without modification.

Glutathione transferase P1 (GSTP1) is a multi-functional protein that protects cells from electrophiles by catalyzing their conjugation with glutathione, and contributes to the regulation of cell proliferation, apoptosis, and signalling. GSTP1, usually described as a cytosolic enzyme, can localize to other cell compartments and we have reported its strong association with the plasma membrane. In the current study, the hypothesis that GSTP1 is palmitoylated and this modification facilitates its dynamic localization and function was investigated. Palmitoylation is the reversible post-translational addition of a 16-C saturated fatty acid to proteins, most commonly on Cys residues through a thioester bond. GSTP1 in MCF7 cells was modified by palmitate, however, GSTP1 Cys to Ser mutants (individual and Cys-less) retained palmitoylation. Treatment of palmitoylated GSTP1 with 0.1 N NaOH, which cleaves ester bonds, did not remove palmitate. Purified GSTP1 was spontaneously palmitoylated in vitro and peptide sequencing revealed that Cys48 and Cys102 undergo S-palmitoylation, while Lys103 undergoes the rare N-palmitoylation. N-palmitoylation occurs via a stable NaOH-resistant amide bond. Analysis of subcellular fractions of MCF7-GSTP1 cells and a modified proximity ligation assay revealed that palmitoylated GSTP1 was present not only in the membrane fraction but also in the cytosol. GSTP1 isolated from E. coli, and MCF7 cells (grown under fatty acid free or regular conditions), associated with plasma membrane-enriched fractions and this association was not altered by palmitoyl CoA. Overall, GSTP1 is modified by palmitate, at multiple sites, including at least one non-Cys residue. These modifications could contribute to regulating the diverse functions of GSTP1. [ABSTRACT FROM AUTHOR]

Abstract Importance This study reports the impact of laser surgery on quality of life in patients with oral cavity lesions. Objective To compare postoperative pain and quality of life in patients treated with flexible fiberoptic CO2 laser vs electrocautery in patients with oral cavity precancerous lesions and early stage cancers. Design Randomized controlled trial. Setting Single center. Participants Patients with premalignant oral cavity lesions and early stage oral cancer. Intervention Patients were randomized to have surgical resection using either flexible fiber carbon dioxide laser (Laser) or electrocautery (EC). The patients were then followed over a period of 28 days to assess for outcomes including pain, quality of life, performance status, return to work, and return to diet. Quality of life was measured by the University of Washington Quality of Life (UWQOL) questionnaire and the performance status score (PSS). Main outcome measure The primary endpoint for this study was the numerical pain rating on postoperative day (POD) 7. Results Sixty‐two patients were randomized (32 laser and 30 electrocautery). Lesions excised were carcinoma in 30(48%), dysplasia in 31(50%) and benign in 1(2%). There was no difference in the location of lesion, size of lesion, defect size, type of closure, resection time, and blood loss between Laser and EC arms. Patients who had Laser had less pain compared to EC (mean pain score on POD 7 L = 2.84 vs EC = 3.83, P = 0.11). better UW QOL scores and PSS scores, quicker return to normal diet (median days L = 26.0 vs EC = 28.5, P = 0.17) and faster return to work (median days L = 13.0 vs EC = 16.5, P = 0.14). However, these results were not statistically significant. Conclusion There was a trend for patients treated with laser to have less pain and better quality of life scores but these result were not statistically significant. Based on the actual observed difference, a large multicenter RCT with 90 patients in each arm is required to determine the clinical relevance of our results.

Abstract Bringing bodies close together at sub-micron distances can drastically enhance radiative heat transfer, leading to heat fluxes greater than the blackbody limit set by Stefan–Boltzmann law. This effect, known as near-field radiative heat transfer (NFRHT), has wide implications for thermal management in microsystems, as well as technological applications such as direct heat to electricity conversion in thermophotovoltaic cells. Here, we demonstrate NFRHT from microfabricated hotplates made by surface micromachining of $$\hbox {SiO}_2$$ SiO 2 / $$\hbox {SiN}$$ SiN thin films deposited on a sacrificial amorphous Si layer. The sacrificial layer is dry etched to form wide membranes ( $${100}\,\upmu \hbox {m} \times {100}\,\upmu \hbox {m}$$ 100 μ m × 100 μ m ) separated from the substrate by nanometric distances. Nickel traces allow both resistive heating and temperature measurement on the micro-hotplates. We report on two samples with measured gaps of $${610}\,\hbox {nm}$$ 610 nm and $${280}\,\hbox {nm}$$ 280 nm . The membranes can be heated up to $${250}\,^{\circ }\hbox {C}$$ 250 ∘ C under vacuum with no mechanical damage. At $${120}\,^{\circ }\hbox {C}$$ 120 ∘ C we observed a 6.4-fold enhancement of radiative heat transfer compared to far-field emission for the smallest gap and a 3.5-fold enhancement for the larger gap. Furthermore, the measured transmitted power exhibits an exponential dependence with respect to gap size, a clear signature of NFRHT. Calculations of photon transmission probabilities indicate that the observed increase in heat transfer can be attributed to near-field coupling by surface phonon-polaritons supported by the $$\hbox {SiO}_2$$ SiO 2 films. The fabrication process presented here, relying solely on well-established surface micromachining technology, is a key step toward integration of NFRHT in industrial applications.

There is an unmet clinical need for simple, accessible biomarkers to select patients who are more likely to respond to immune checkpoint therapy. Here the authors show that a lower neutrophil-to-lymphocyte ratio is associated with better overall and progressive-free survival, as well as higher rate of response, in a multi-cancer cohort of patients treated with immune checkpoint inhibitors.

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.

BackgroundThe purpose of this study was to report the clinical outcomes and related prognostic factors of patients who underwent radiotherapy (RT) for the treatment of recurrent, never-irradiated oral cavity cancer (recurrent OCC).MethodsThe records of consecutive patients with nonmetastatic recurrent OCC who presented to and were treated with RT at our institution between 1989 and 2011 were reviewed. The Kaplan-Meier method was used to calculate overall survival (OS). The cumulative incidences of disease-specific death, local failure, regional failure, and distant metastasis were calculated with death as a competing risk.ResultsOne hundred twenty-three patients were identified. Median follow-up for living patients was 54 months and 16 months for all patients. Ninety-one patients had salvage surgery followed by adjuvant RT. Definitive RT was utilized in the remaining 32 patients. The 5-year OS was 40%. The 5-year cumulative incidence of disease-specific death, local failure, regional failure, and distant metastasis was 55%, 34%, 22%, and 20%, respectively. Recurrent T classification and lack of salvage surgery were independently associated with worse disease-specific death and decreased OS, respectively. Subset analysis of patients who underwent salvage surgery demonstrated that age, recurrent T classification, and perineural invasion (PNI) were independently associated with decreased OS; recurrent T classification and thicker tumors were independently associated with worse disease-specific death; and positive/close margins and primary T classification were independently associated with increased local failure.ConclusionIn this group of patients with recurrent OCC, clinical outcomes were similar or improved when compared with other recurrent OCC-specific reports. In the salvage surgery subset, tumor thickness and PNI are recurrent pathologic features associated with outcomes that were only previously demonstrated in studies of primary disease. Because of the relatively worse outcomes in patients receiving definitive or adjuvant RT for recurrent OCC, we advocate for the appropriate use of postoperative RT in the initial management of oral cavity cancers.