Neoadjuvant programmed death-1 blockade plus chemotherapy in locally advanced esophageal squamous cell carcinoma

Background

Immunotherapy is effective in treating unresectable esophageal squamous cell carcinoma (ESCC), but little is known about its role in the preoperative setting. The aim of this study was to evaluate the safety, feasibility and efficacy of neoadjuvant treatment with camrelizumab plus chemotherapy in locally advanced ESCC.

Methods

Patients diagnosed with locally advanced ESCC were retrospectively included if they had received neoadjuvant camrelizumab plus nab-paclitaxel and S1 capsule followed by radical esophagectomy between November, 2019 and June, 2020 at Sun Yat-sen University Cancer Center. Primary endpoints were safety and feasibility. In addition, pathological response and the relationship between tumor immune microenvironment (TIME)/tumor mutational burden (TMB) and treatment response were also investigated.

Results

Twelve patients were included and they all received three courses of preoperative treatment with camrelizumab plus nab-paclitaxel/S1. No grade 3 or higher toxicities occurred. No surgical delay or perioperative death was reported. Nine patients (75%) responded to the treatment, four with a complete pathological response (pCR) and five with a major pathological response (MPR). Neither programmed death-ligand 1 (PD-L1) expression nor TMB was correlated with treatment response. TIME analysis revealed that a higher abundance of CD56dim natural killer cells was associated with better pathological response in the primary tumor, while lower density of M2-tumor-associated macrophages was associated with better pathological response in the lymph nodes (LNs).

Conclusions

Neoadjuvant camrelizumab plus nab-paclitaxel and S1 is safe, feasible and effective in locally advanced ESCC and is worth further investigation.

Defect evolution behaviors from single sulfur point vacancies to line vacancies in monolayer molybdenum disulfide

Two-dimensional monolayer transition metal dichalcogenides (TMDs) are promising candidates for many novel nanoelectronic and optoelectronic applications due to their exceptional electronic, optical, chemical and mechanical properties. Experimentally, single chalcogen point vacancies caused by electron beam irradiation are found to agglomerate into line vacancy defects in monolayer TMDs. Herein, the corresponding defect evolution behaviors from single sulfur point vacancies to line vacancies in the monolayer molybdenum disulfide (MoS₂) have been systematically studied using molecular dynamics and first principles calculations. The experimental observations of the defect evolution from single sulfur point vacancies to line vacancies are reproduced at the atomic level. The results indicate that the di-vacancy line defect and a point vacancy separated by a sulfur atom in a line evolve into tri-vacancy line defects, and the di-vacancy line defects can rotate 60° clockwise or counterclockwise. Moreover, two adjacent di-vacancy line defects with an angle of 120° can evolve into tri-vacancy line defects. High temperature and large vacancy concentrations promote the defect evolution from point vacancies to line vacancies. Intriguingly, compared with the randomly distributed point vacancy defects, the line vacancy defects formed after the defect evolution significantly decrease the mechanical properties, such as the ultimate strength, ultimate strain and Young's modulus of monolayer MoS₂. In addition, the mechanical properties decrease with increasing vacancy concentration and temperature for the final configurations after defect evolution in monolayer MoS₂ with different vacancy concentrations at different temperatures. The band gaps of monolayer MoS₂ with line vacancy defects are smaller than those with randomly distributed point vacancy defects. Therefore, our study clarifies the defect evolution behaviors from single sulfur point vacancies to line vacancies in monolayer MoS₂ and opens an opportunity for the novel nanoelectronic and optoelectronic applications of monolayer TMDs.

TRIM18-Regulated STAT3 Signaling Pathway via PTP1B Promotes Renal Epithelial-Mesenchymal Transition, Inflammation, and Fibrosis in Diabetic Kidney Disease

Diabetic kidney disease (DKD) has become a key cause of end-stage renal disease worldwide. Inflammation and fibrosis have been shown to play important roles in the pathogenesis of DKD. MID1, also known as TRIM18, is an E3 ubiquitin ligase of the tripartite motif (TRIM) subfamily of RING-containing proteins and increased in renal tubule in patients with DKD. However, the function and molecular mechanism of TRIM18 in DKD remain unexplored. Herein we report that TRIM18 expression levels were increased in patients with DKD. An animal study confirms that TRIM18 is involved in kidney injury and fibrosis in diabetic mice. TRIM18 knockdown inhibits high glucose (HG)-induced epithelial–mesenchymal transition (EMT), inflammation, and fibrosis of HK-2 cells. This is accompanied by decreased levels of tumor necrosis factor alpha, interleukin-6, hydroxyproline (Hyp), connective tissue growth factor, and α-smooth muscle actin. Additionally, TRIM18 knockdown inhibits HG-induced increase in the phosphorylated-/total signal transducer and activator of transcription (STAT3). Treatment with niclosamide (STAT3 inhibitor) or protein tyrosine phosphatase-1B (PTP1B) overexpression blocked the TRIM18 induced EMT, inflammation and fibrosis. Co-immunoprecipitation and Western blot assays showed that TRIM18 promoted the ubiquitination of PTP1B. These findings highlight the importance of the TRIM18/PTP1B/STAT3 signaling pathway in DKD and can help in the development of new therapeutics for DKD treatment.

Haplotype-resolved genome assembly and allele-specific gene expression in cultivated ginger

Ginger (Zingiber officinale) is one of the most valued spice plants worldwide; it is prized for its culinary and folk medicinal applications and is therefore of high economic and cultural importance. Here, we present a haplotype-resolved, chromosome-scale assembly for diploid ginger anchored to 11 pseudochromosome pairs with a total length of 3.1 Gb. Remarkable structural variation was identified between haplotypes, and two inversions larger than 15 Mb on chromosome 4 may be associated with ginger infertility. We performed a comprehensive, spatiotemporal, genome-wide analysis of allelic expression patterns, revealing that most alleles are coordinately expressed. The alleles that exhibited the largest differences in expression showed closer proximity to transposable elements, greater coding sequence divergence, more relaxed selection pressure, and more transcription factor binding site differences. We also predicted the transcription factors potentially regulating 6-gingerol biosynthesis. Our allele-aware assembly provides a powerful platform for future functional genomics, molecular breeding, and genome editing in ginger.

Optical Excitation and Trapping of ^{81}Kr

We have realized optical excitation, trapping, and detection of the radioisotope ^{81}Kr with an isotopic abundance of 0.9 ppt. The 124 nm light needed for the production of metastable atoms is generated by a resonant discharge lamp. Photon transport through the optically thick krypton gas inside the lamp is simulated and optimized to enhance both brightness and resonance. We achieve a state-of-the-art ^{81}Kr loading rate of 1800  atoms/h, which can be further scaled up by adding more lamps. The all-optical approach overcomes the limitations on precision and sample size of radiokrypton dating, enabling new applications in the earth sciences, particularly for dating of polar ice cores.

Genomic Profiling of Circulating Tumor DNA from Patients with Extensive-Stage Small Cell Lung Cancer Identifies Potentially Actionable Alterations

Comprehensive genomic profiling may help uncover potentially actionable alterations in small cell lung cancer (SCLC) patients who have progressed on standard chemotherapy. However, tissue procurement may be extremely challenging for extensive-stage patients. We aimed to investigate the possibility of genomic profiling and detecting actionable alterations from blood in Chinese SCLC patients. Blood samples collected from extensive-stage SCLC pateints were subjected to circulating tumor DNA (ctDNA) extraction and targeted-next generation sequencing (NGS) using a 150-gene panel. A total of 1,300 aberrations were detected in 128 genes and 89.2% (116/130) patients harbored at least one oncogenic alteration. The most frequently mutated genes included TP53 (82.3%), RB1 (56.2%), LRP1B (40.8%) etc. and 54.6% of the patients had concurrent TP53/RB1 mutations. The RTK/RAS/RAF axis was the most frequently mutated oncogenic pathway. Samples harboring alterations in the DNA damaging repair (DDR), Notch, PI3K/mTOR, RTK/RAS/RAF, and Wnt pathways exhibited significantly higher blood tumor mutational burden (bTMB) than their wildtype counterparts. Classification based on OncoKB criteria detected potentially actionable alterations in about 50% of the population, half of which were bTMB-H and bMSI-H, indicating response to immune checkpoint inhibitors. Alterations in the RTK/RAS/RAF, DDR, and PI3K/mTOR also suggested potential sensitivity to matched targeted therapies or emerging investigational agents. Blood-based panel NGS is promising for delineating genomic landscape of SCLC and may also shed some light on treatment selection for Chinese SCLC patients.

Molecular characterization of ctDNA from Chinese patients with advanced gastric adenocarcinoma reveals actionable alterations for targeted and immune therapy

Circulating tumor DNA (ctDNA) is considered an ideal sample type for genotyping patients with advanced unresectable cancer to inform treatment decision. It may better capture tumor heterogeneity, especially in gastric adenocarcinoma (GAC). However, there exists little evidence regarding genomic profiling of Chinese advanced GAC patients from ctDNA. Blood samples were obtained from 200 advanced GAC patients. Next-generation sequencing (NGS) was performed on ctDNA using a validated 150-gene panel. Blood tumor mutation burden (bTMB) was calculated according to the NGS results. Blood microsatellite instability (bMSI) status was determined by targeted sequencing of 100 microsatellite loci. One hundred sixty-nine (84.5%) patients carried at least one genomic alteration and 138 (69%) patients had at least one deleterious or likely deleterious alteration (del-alteration). The clonal fraction of del-alterations was higher than that of non-del-alterations (80.1% vs 54.5%, P < 0.0001). The most frequently altered genes were TP53 (38%), LRP1B (20%), MYC (13.5%), ERBB2 (12.5%), and KRAS (11.5%). The alterations were most enriched in the TP53/cell cycle (52%) and the RTK-Ras-MAPK pathway (51.5%). The median bTMB was two (range 0 to 42). Eight patients were identified to be high bMSI, with higher median bTMB than the blood microsatellite stable (bMSS) patients (15 vs 2, P = 0.0062). Patients harboring del-alterations of the DDR pathway had significantly higher percentages of high bTMB and bMSI-H patients than the wild-type subgroup (61.1% vs 6.5%, P < 0.0001; 33.3% vs 1.7%, P = 0.0002). A total of 45.5% cases harbored at least one potentially actionable alteration and one patient achieved complete response after receiving matched targeted therapy. Our study uncovered the molecular characterization of Chinese patients with advanced GAC from ctDNA, including genomic alteration, bTMB, and bMSI status. The findings suggested that targeted NGS-based ctDNA analysis may help inform the clinical decision in advanced GAC. KEY MESSAGES: We report the molecular profiling of the largest Chinese advance stage GACs cohort using a CLIA-certified ctDNA assay. Potentially actionable genomic alterations were identified in 45.5% of patients, suggesting clinical utility for ctDNA NGS in advance stage GACs. There was evidence of clinical benefit in one GAC patient with MET amplification treated with MET inhibitor.

The predictive value of MAP2K1/2 mutations for efficiency of immunotherapy in melanoma

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Background: Immunotherapies targeting immune checkpoint receptors have become the cornerstone of systemic treatment options for malignant melanoma. The response to these immunotherapies may correlate with driver mutations. MAP2K1/2 genes are mutated in approximately 10% of melanomas, however, the impact of MAP2K1/2 gene alterations on the efficiency of immunotherapy has not been clarified. Methods: Six metastatic melanoma clinical cohorts treated with ICIs were included to investigate the association between clinical efficacy of immunotherapy and MAP2K1/2 mutations. Survival analyses were conducted in cohorts receiving two kinds of ICB agents, namely anti-CTLA-4 or anti-PD-1. RNA expression profiling from these cohorts and from the TCGA melanoma cohort were used to explore the potential mechanism related to immune activation. Results: In an independent anti-CTLA-4-treated cohort (n = 110), we found that MAP2K1/2 mutations are predictive of high objective response rate (17.6% vs 1.3%, p = 0.0185) and long progression-free survival [median OS, 49.2 months vs 8.3 months; hazard ratio (HR) = 0.37; 95% CI, 0.15–0.91; p = 0.0307] and overall survival (median PFS, 19.4 months vs 2.8 months; HR = 0.2; 95% CI, 0.05–0.83; p = 0.0262). This predictive value was further validated in a pooled anti-CTLA-4-treated cohort (n = 235) in terms of overall survival (median OS, 49.3 months vs 22.0 months; HR = 0.44; 95% CI, 0.22–0.91; p = 0.0255). However, no correlation between MAP2K1/2 mutations and overall survival was observed in the anti-PD-1-treated cohort (n = 285). Subgroup Cox regression analysis indicated that MAP2K-mutated patients receive less benefit from the anti-PD-1 monotherapy than from the anti-CTLA-4 treatment (median OS, 27.0 months vs 49.3 months; HR = 3.26; 95% CI, 1.18–9.02; p = 0.0225), which was contrary to the result obtained for the total population. Furthermore, transcriptome profiling analysis revealed that MAP2K-mutated tumors are enriched in CD8+ T cells, B cells, and neutrophil cells and also express high levels of CD33 and IL10, which might be the underlying mechanism for melanoma patients with MAP2K1/2-mutated benefit more from anti-CTLA-4 treatment. Conclusions: We identified mutations in MAP2K1/2 genes as the independent predictive factors for anti-CTLA-4 therapy in melanoma patients and found that anti-CTLA-4 treatment in patient harbouring MAP2K1/2 mutations might be more effective than the anti-PD-1 therapy.

Neoadjuvant programmed death-1 blockade plus chemotherapy in locally advanced esophageal squamous cell carcinoma

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Background: Immunotherapy is effective in treating advanced esophageal squamous cell carcinoma (ESCC), but little is known about its role in the setting of neoadjuvant therapy. Methods: Data from a retrospective cohort and a prospective cohort of locally advanced ESCC patients were analyzed. All patients included had received neoadjuvant camrelizumab plus nab-paclitaxel and S1 capsule followed by radical esophagectomy. The main purpose of this study was to evaluate the safety and feasibility of the neoadjuvant treatment. In addition, pathological response and the relationship between tumor immune microenvironment features (TIME)/tumor mutational burden (TMB) and treatment response were also explored. Results: A total of 25 locally advanced ESCC patients from both cohorts were included, of which 12 from the retrospective cohort and 13 from the prospective cohort. Only two patients experienced grade 3 or 4 adverse events, including onehad anemia and the other (4%) had limb numbness. No surgical delay or perioperative death was reported. Sixteen patients (64%) responded to the treatment, eight (32%) with a complete pathological response and eight (32%) with a major pathological response. Neither programmed death-ligand 1 expression nor TMB was correlated with treatment response. In terms of TIME analysis, patients with better pathological response in the primary tumor had significantly higher abundance of CD56dim natural killer cells (109 vs 32, P= 0.01), while lower density of M2-tumor-associated macrophages was associated with numerically better pathological response in the lymph nodes (47 vs 163.1, P= 0.55). Conclusions: Neoadjuvant camrelizumab plus nab-paclitaxel and S1 is safe, feasible and effective, and the efficacy could be predicted by TIME, which is worthy of further investigation. Clinical trial information: ChiCTR2000029807.

92 Reshaping the Diagnostic Pathways for Investigation of Haematuria During and After The COVID-19 Pandemic: Diagnostic Accuracy of Strategies for Detection of Bladder Cancer from The IDENTIFY Cohort Study

Introduction

Diagnostic haematuria services have been reduced due to the COVID-19 pandemic, compromising patient care, and necessitating a more pragmatic pathway.

Method

The IDENTIFY study was an international, prospective, multicentre cohort study of over 11,000 patients referred to secondary care for investigation of haematuria. Using this data, we developed strategies using combinations of imaging and cytology as triage tests to maximise cancer detection within a pragmatic pathway.

Results

8112 patients (74·4%) received an ultrasound or a CT urogram, with or without cytology. 5737 (70·7%) patients had visible haematuria (VH) and 2375 (29·3%) had non-visible haematuria (NVH). Diagnostic test performance was used to determine optimal age cut-offs for four proposed strategies. We recommended proceeding directly to transurethral resection of bladder tumour for patients of any age with positive triage tests for cancer. Patients with negative triage tests under 35-years-old with VH, or under 50-years-old with NVH can safely be discharged without undergoing flexible cystoscopy. The remaining patients may undergo flexible cystoscopy, with a greater priority for older patients to capture high risk bladder cancer.

Conclusions

We suggest diagnostic strategies in patients with haematuria, which focus on detection of bladder cancer, whilst reducing the burden to healthcare services in a resource-limited setting.

377 Global Recruitment for The RESECT Study (Transurethral Resection and Single-Instillation Intravesical Chemotherapy Evaluation in Bladder Cancer Treatment): An International Observational Cohort Study Aiming to Improve the Quality of Surgery for Non-Muscle Invasive Bladder Cancer

Introduction

Non-muscle invasive bladder cancer (NMIBC) can be curatively treated with ‘good quality’ transurethral resection of the bladder tumour (TURBT). However, despite evidence-based international guidelines, there is anecdotal evidence that practice varies widely, and this may affect oncological outcomes. Launching in 2020, RESECT aims to measure and report variation in TURBT quality globally, and determine if outcome reporting improves outcomes.

Method

RESECT was advertised internationally through social media, mailing lists, websites, and in person. Collaborators at each registered site will collect data about current practice and the experience of local TURBT surgeons. The primary outcome is the rate of achievement of key TURBT quality indicators.

Results

As of August 27, 508 collaborators have registered to participate. Collaborators represent 321 centres from 54 countries, with the highest number from the United Kingdom (54.5%), Spain (5.9%), and Argentina (3.7%). 51.2% are trainees, 29.9% consultants, and 17.5% medical students. Based on current registrations, patient recruitment will far exceed initial projections and considerably improve statistical power.

Conclusions

RESECT has attracted a large number of collaborators globally and from all training levels. Therefore, the RESECT study has the potential to improve the quality of TURBT surgery across the world.

The efficacy of dendritic cell vaccine for newly diagnosed glioblastoma: A meta-analysis of randomized controlled studies

INTRODUCTION

The efficacy of dendritic cell vaccine to treat glioblastoma remained elusive and therefore we conducted a meta-analysis to explore the influence of dendritic cell vaccine on treatment efficacy of glioblastoma.

METHODS

PubMed, EMbase, Web of science, EBSCO and Cochrane library databases have been searched through October 2020, and we included randomized controlled trials (RCTs) assessing the efficacy of dendritic cell vaccine for glioblastoma.

RESULTS

Four RCTs and 267 patients were included in the meta-analysis. Compared to control group for glioblastoma, dendritic cell vaccine demonstrated no obvious impact on overall survival (HR=0.59; 95% CI=0.34 to 1.04; P=0.07), progression-free survival (PFS, HR=0.72; 95% CI=0.52 to 1.00; P=0.05), nervous system disorders (OR=0.61; 95% CI=0.29 to 1.29; P=0.20), or adverse events (OR=1.44; 95% CI=0.82 to 2.50; P=0.20).

CONCLUSIONS

Dendritic cell vaccine may be not effective to treat glioblastoma.

P57 Global recruitment for the RESECT study (transurethral REsection and Single-instillation intravesical chemotherapy Evaluation in bladder Cancer Treatment) - an international observational cohort study aiming to improve the quality of surgery for non-muscle invasive bladder cancer

Introduction

Non-muscle invasive bladder cancer (NMIBC) is one of the most expensive cancers to treat, driven by high recurrence rates and disease progression. Mortality rates in the UK for all bladder cancers have remained relatively stable over the past decade. NMIBC can be curatively treated with transurethral resection of the bladder tumour (TURBT). Despite international evidence-based guidelines on the TURBT procedure and postoperative single instillation of mitomycin-C, TURBT quality continues to vary widely. RESECT will be the first ever international study of TURBT surgery evaluating the achievement of TURBT quality indicators globally and assessing if audit and performance feedback can improve surgical outcomes.

Methods

RESECT is a prospective, multicentre international observational cohort study. Collaborators at each site will collect data using REDCap about local TURBT practice, early recurrence rates and the experience of local TURBT surgeons. The primary outcome is the rate of achievement of key TURBT quality indicators. Advertisement for the study launched in 2020.

Results

As of October 1st, 2020, 524 collaborators have registered to participate. Collaborators represent 334 centres from 54 countries, with the highest number of centres from the United Kingdom (133), Spain (17), and India (16). 50.8% are trainees, 30.3% consultants, and 17.2% medical students. Based on current registrations, patient recruitment will far exceed initial projections and considerably improve statistical power.

Conclusion

RESECT has attracted many collaborators internationally from consultants and trainees at all stages. RESECT has significant potential to positively impact TURBT practice, health economics and ultimately improve outcomes for patients with NMIBC globally.

A next-generation sequencing-based strategy combining microsatellite instability and tumor mutation burden for comprehensive molecular diagnosis of advanced colorectal cancer

Background

Mismatch repair (MMR)/microsatellite instability (MSI) and tumor mutational burden (TMB) are independent biomarkers that complement each other for predicting immune checkpoint inhibitors (ICIs) efficacy. Here we aim to establish a strategy that integrates MSI and TMB determination for colorectal cancer (CRC) in one single assay.

Methods

Surgical or biopsy specimens retrospectively collected from CRC patients were subjected to NGS analysis. Immunohistochemistry (IHC) and polymerase chain reaction (PCR) were also used to determine MMR/MSI for those having enough tissues. The NGS-MSI method was validated against IHC and PCR. The MSI-high (MSI-H) or microsatellite stable (MSS) groups were further stratified based on tumor mutational burden, followed by validation using the The Cancer Genome Atlas (TCGA) CRC dataset. Immune microenvironment was evaluated for each subgroup be profiling the expression of immune signatures.

Results

Tissues from 430 CRC patients were analyzed using a 381-gene NGS panel. Alterations in KRAS, NRAS, BRAF, and HER2 occurred at a significantly higher incidence among MSI-H tumors than in MSS patients (83.6% vs. 58.4%, p = 0.0003). A subset comprising 98 tumors were tested for MSI/MMR using all three techniques, where NGS proved to be 99.0 and 93.9% concordant with PCR and IHC, respectively. Four of the 7 IHC-PCR discordant cases had low TMB (1.1–8.1 muts/Mb) and were confirmed to have been misdiagnosed by IHC. Intriguingly, 4 of the 66 MSS tumors (as determined by NGS) were defined as TMB-high (TMB-H) using a cut-off of 29 mut/Mb. Likewise, 15 of the 456 MSS tumors in the TCGA CRC cohort were also TMB-H with a cut-off of 9 muts/Mb. Expression of immune signatures across subgroups (MSS-TMB-H, MSI-H-TMB-H, and MSS-TMB-L) confirmed that the microenvironment of the MSS-TMB-H tumors was similar to that of the MSI-H-TMB-H tumors, but significantly more immune-responsive than that of the MSS-TMB-L tumors, indicating that MSI combined with TMB may be more precise than MSI alone for immune microenvironment prediction.

Conclusion

This study demonstrated that NGS panel-based method is both robust and tissue-efficient for comprehensive molecular diagnosis of CRC. It also underscores the importance of combining MSI and TMB information for discerning patients with different microenvironment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07942-1.

The Relationship between Serum Procalcitonin and Dialysis Adequacy in Peritoneal Dialysis Patients

Background:

To detect the serum procalcitonin (PCT) levels of peritoneal dialysis (PD) patients.

Methods:

We analyzed the relationship between the PCT Level and dialysis adequacy. We studied 120 peritoneal dialysis patients without signs of infection in Affiliated Hangzhou First People’s Hospital and 120 controls from Jan 2014 to Apr 2016. PCT and high sensitivity C-reactive protein (hs-CRP) were detected. 120 PD patients were divided into two groups according to the dialysis adequacy. A correlation analysis was processed between the PCT level and the total solute clearance (Kt/V). The value of PCT for identifying the dialysis adequacy in PD patients was assessed by ROC curve analysis.

Results:

PCT level in serum of PD group (0.29±0.24 ng/ml) was higher than that of the control group (0.02±0.01 ng/ml) (P<0.01). Compared with the inadequate dialysis group (0.5±0.37 ng/ml), the PCT Level of the adequate dialysis group (0.23±0.15 ng/ml) was lower (P<0.01). There were negative correlations between PCT and Kt/v(r=−0.451), Prealbumin (PA) (r=−0.258), Glomerular Filtration Rate (eGFR; r=−0.280), while there was positive correlation between PCT and Hypersensitive c-reactive protein (r=0.458) (P<0.01). At a serum PCT cut-off value of 0.283 ng/ml, the sensitivity and specificity for identifying the dialysis adequacy in PD patients were 0.913 and 0.805 respectively. The serum levels of PCT in peritoneal dialysis patients were significantly higher than the levels in healthy controls.

Conclusion:

The serum level of PCT can be used as an indirect maker to evaluate the adequacy of dialysis.

Axl and Mertk Receptors Cooperate to Promote Breast Cancer Progression by Combined Oncogenic Signaling and Evasion of Host Antitumor Immunity

Despite the promising clinical benefit of targeted and immune checkpoint blocking therapeutics, current strategies have limited success in breast cancer, indicating that additional inhibitory pathways are required to complement existing therapeutics. TAM receptors (Tyro-3, Axl, and Mertk) are often correlated with poor prognosis because of their capacities to sustain an immunosuppressive environment. Here, we ablate Axl on tumor cells using CRISPR/Cas9 gene editing, and by targeting Mertk in the tumor microenvironment (TME), we observed distinct functions of TAM as oncogenic kinases, as well as inhibitory immune receptors. Depletion of Axl suppressed cell intrinsic oncogenic properties, decreased tumor growth, reduced the incidence of lung metastasis and increased overall survival of mice when injected into mammary fat pad of syngeneic mice, and demonstrated synergy when combined with anti-PD-1 therapy. Blockade of Mertk function on macrophages decreased efferocytosis, altered the cytokine milieu, and resulted in suppressed macrophage gene expression patterns. Mertk-knockout mice or treatment with anti-Mertk-neutralizing mAb also altered the cellular immune profile, resulting in a more inflamed tumor environment with enhanced T-cell infiltration into tumors and T-cell-mediated cytotoxicity. The antitumor activity from Mertk inhibition was abrogated by depletion of cytotoxic CD8α T cells by using anti-CD8α mAb or by transplantation of tumor cells into B6.CB17-Prkdc SCID mice. Our data indicate that targeting Axl expressed on tumor cells and Mertk in the TME is predicted to have a combinatorial benefit to enhance current immunotherapies and that Axl and Mertk have distinct functional activities that impair host antitumor response. SIGNIFICANCE: This study demonstrates how TAM receptors act both as oncogenic tyrosine kinases and as receptors that mediate immune evasion in cancer progression.

Enhanced antitumor immunity by a novel small molecule HPK1 inhibitor

Background

Hematopoietic progenitor kinase 1 (HPK1 or MAP4K1) has been demonstrated as a negative intracellular immune checkpoint in mediating antitumor immunity in studies with HPK1 knockout and kinase dead mice. Pharmacological inhibition of HPK1 is desirable to investigate the role of HPK1 in human immune cells with therapeutic implications. However, a significant challenge remains to identify a small molecule inhibitor of HPK1 with sufficient potency, selectivity, and other drug-like properties suitable for proof-of-concept studies. In this report, we identified a novel, potent, and selective HPK1 small molecule kinase inhibitor, compound K (CompK). A series of studies were conducted to investigate the mechanism of action of CompK, aiming to understand its potential application in cancer immunotherapy.

Methods

Human primary T cells and dendritic cells (DCs) were investigated with CompK treatment under conditions relevant to tumor microenvironment (TME). Syngeneic tumor models were used to assess the in vivo pharmacology of CompK followed by human tumor interrogation ex vivo.

Results

CompK treatment demonstrated markedly enhanced human T-cell immune responses under immunosuppressive conditions relevant to the TME and an increased avidity of the T-cell receptor (TCR) to recognize viral and tumor-associated antigens (TAAs) in significant synergy with anti-PD1. Animal model studies, including 1956 sarcoma and MC38 syngeneic models, revealed improved immune responses and superb antitumor efficacy in combination of CompK with anti-PD-1. An elevated immune response induced by CompK was observed with fresh tumor samples from multiple patients with colorectal carcinoma, suggesting a mechanistic translation from mouse model to human disease.

Conclusion

CompK treatment significantly improved human T-cell functions, with enhanced TCR avidity to recognize TAAs and tumor cytolytic activity by CD8+ T cells. Additional benefits include DC maturation and priming facilitation in tumor draining lymph node. CompK represents a novel pharmacological agent to address cancer treatment resistance.

Synergistic vacancy defects and mechanical strain for the modulation of the mechanical, electronic and optical properties of monolayer tungsten disulfide

Monolayer transition metal dichalcogenides (TMDs) are the potential candidate materials in nanoelectronic and optoelectronic applications due to their unique physical and chemical properties. Although both defect and strain greatly alter the structural, physical and chemical properties of monolayer TMDs, the defective monolayer TMDs under applied strain have not been adequately studied. In this paper, the synergistic effects of sulfur vacancy defects and mechanical strain on the mechanical, electronic and optical properties of monolayer tungsten disulfide (WS2) have been systematically studied using first principles density functional theory. The results indicate that the sulfur vacancy formation energy increases linearly with increasing sulfur vacancy concentration under different strains. The strain energy and stress of monolayer WS2 with different sulfur vacancy concentrations increase with increasing applied strain in the strain range of -10% to 10%. The band gap of monolayer WS2 decreases with increasing sulfur vacancy concentration under different strains. Moreover, compared with unstrained conditions, 5% compressive strain increases the band gap at a larger vacancy concentration and the case is just opposite at a smaller vacancy concentration, while 5% tensile strain decreases the band gap. The band gap of monolayer WS2 with different sulfur vacancy concentrations firstly increases and then shrinks with increasing applied strain under compressive strain, whereas it decreases monotonically under tensile strain in the strain range of -10% to 10%. In the visible-light wavelength region, the out-of-plane absorption coefficient under different strains increases with increasing sulfur vacancy concentration. Furthermore, 5% compressive strain enhances the absorption coefficient and 5% tensile strain decreases the absorption coefficient. Hence, the synergistic effects of sulfur vacancy defects and mechanical strain in monolayer TMDs can open new avenues for their applications in nanoelectronic and optoelectronic devices.

Anomalous Octahedron Distortion of Bi-Alloyed Cs2AgInCl6 Crystal via XRD, Raman, Huang-Rhys Factor, and Photoluminescence

The refinement of XRD patterns only provides the average structure parameters for the alloying materials because of the symmetric protection. Raman vibrational modes can append the detailed information about the bond length and structure. The refinements of XRD patterns for Bi alloying Cs₂AgInCl₆ revealed the strong structure distortion with the enlarged octahedron of In(Bi)Cl₆ and the contracted octahedron of AgCl₆ with the increasing Bi. Raman spectra supported the expanded octahedron of InCl₆ and the reduced octahedron of AgCl₆ but identified the anomalous shortening bond length of Bi-Cl with the increasing Bi. These distorting octahedrons break parity forbidden transition, modify Huang-Rhys factor, and result in the maximum values at 30% Bi alloying and the same variation trend for both photoluminescence and Huang-Rhys factor with the increasing Bi alloying.

Plasma-based microsatellite instability detection strategy to guide immune checkpoint blockade treatment

Background

Microsatellite instability (MSI) represents the first pan-cancer biomarker approved to guide immune checkpoint blockade (ICB) treatment. However its widespread testing, especially outside of gastrointestinal cancer, is hampered by tissue availability.

Methods

An algorithm for detecting MSI from peripheral blood was established and validated using clinical plasma samples. Its value for predicting ICB efficacy was evaluated among 60 patients with advanced gastrointestinal cancer. The landscape of MSI in blood was also explored among 5138 advanced solid tumors.

Results

The algorithm included 100 microsatellite markers with high capture efficiency, sensitivity, and specificity. In comparison with orthogonal tissue PCR results, the method displayed a sensitivity of 82.5% (33/40) and a specificity of 96.2% (201/209), for an overall accuracy of 94.0% (234/249). When the clinical validation cohort was dichotomized by pretreatment blood MSI (bMSI), bMSI-high (bMSI-H) predicted both improved progression-free survival and overall survival than the blood microsatellite stable (bMSS) patients (HRs: 0.431 and 0.489, p=0.005 and 0.034, respectively). Four patients with bMSS were identified to have high blood tumor mutational burden (bTMB-H) and trended towards a better survival than the bMSS-bTMB-low (bTMB-L) subset (HR 0.026, 95% CI 0 to 2.635, p=0.011). These four patients with bMSS-bTMB-H plus the bMSI-H group collectively displayed significantly improved survival over the bMSS-bTMB-L patients (HR 0.317, 95% CI 0.157 to 0.640, p<0.001). Pan-cancer prevalence of bMSI-H was largely consistent with that shown for tissue except for much lower rates in endometrial and gastrointestinal cancers, and a remarkably higher prevalence in prostate cancer relative to other cancer types.

Conclusions

We have developed a reliable and robust next generation sequencing-based bMSI detection strategy which, in combination with a panel enabling concurrent profiling of bTMB from a single blood draw, may better inform ICB treatment.

A prospective multicentre randomized all-comers trial to assess the safety and effectiveness of the ultra-thin-strut sirolimus-eluting coronary stent Supraflex: 2-year results of the TALENT trial

Background and purpose

Supraflex is a sirolimus-eluting stent with a biodegradable polymeric coating and 60um ultra-thin struts. In the TALENT study, we found the Supraflex stent was non-inferior to the Xience stent for a device-oriented composite endpoint (DOCE, defined as cardiac death, target-vessel myocardial infarction, or clinically indicated target lesion revascularisation) at 12 months in an all-comer population. Additionally, per-protocol analysis showed a significantly lower clinically indicated target lesion revascularisation (CI-TLR) in the Supraflex group than in the Xience group. We now present the 2-year follow-up results.

Methods

The TALENT study was a prospective, randomised, single-blind, multicentre study across 23 centres in Europe. Eligible participants underwent percutaneous coronary intervention in an all-comers fashion in vessels of 2.25–4.5 mm. Patients were randomized (1:1) to implantation of either Supraflex or Xience (NCT02870140).

Results

Between October 21, 2016 and July 3, 2017, 720 patients with 1046 lesions were randomly assigned to Supraflex, and 715 patients with 1030 lesions to Xience. At 24 months, DOCE had occurred in 49 patients (6.9%) in the Supraflex group and in 56 patients (7.9%) in the Xience group (absolute difference −1.0% [95% CI: −3.7 to 1.7], Plog-rank=0.491). Per-protocol analysis at 24 months showed CI-TLR occurred in 21 and 30 patients in the Supraflex and Xience, respectively (3.3% versus 4.5%, absolute difference −1.2%, [95% CI: −3.3 to 0.9], Plog-rank=0.267).

Conclusion

In an all-comer population, at 2-year follow-up, the use of Supraflex stent was at least as safe and efficacious as Xience stent. However, the significantly lower rate of CI-TLR shown in patients treated with Supraflex at 1-year was no longer retained in the 2-year results. Whether theoretical advantage of ultra-thin strut drug eluting stents Supraflex can translate into clinical benefit or not will be further elucidated through a total of 3 years of follow-up.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): SMT