Biomarkers For Immunotherapy Research Articles

Abstract A031: Identification of therapeutic vulnerabilities in the subset of pancreatic ductal adenocarcinoma (PDAC) with homologous recombination deficiency

Abstract The genetic landscape of pancreatic ductal adenocarcinoma (PDAC) is characterized by mutations in the KRAS, TP53, CDKN2A and SMAD4 genes alongside multiple low-frequency mutations, which may offer opportunities for precision medicine. The success of poly-ADP-ribose polymerase (PARP) inhibitors in metastatic PDAC characterized by germline mutations in the Breast Cancer (BRCA) genes has led to the hypothesis that mutations in other BRCAness genes may sensitize PDAC to PARP inhibitors. To test this hypothesis, we used KPC mice as a backbone (Pdx1-Cre; LSL-KrasG12D/+; LSL-Trp53R172H/+) to generate models of PDAC driven by the loss of Ataxia Telangiectasia mutated (Atm, KPCA) or Brca1 (KPCB). Loss of Atm or Brca1 resulted in homologous recombination deficiency and genomic instability in vivo. In vitro cultures of KPCA and KPCB PDAC cells had higher numbers of micronuclei and were more radiosensitive than KPC cells. Next, we performed bulk and single-cell RNA sequencing to identify therapeutic vulnerabilities associated with Atm or Brca1 loss. We found that loss of Atm upregulated ATR signaling, suggesting ATR as a therapeutic target in KPCA mice. In agreement, ATR inhibition improved the survival of KPCA mice, with evidence of tumor growth delay. However, though PARP inhibition significantly improved the survival of KPCB mice, with delayed tumor growth, it was ineffective in KPCA mice. In addition, transcriptomic analysis showed an enrichment of immune cells in KPCB PDAC compared to KPC and KPCA PDAC. Notably, we found greater levels of STING signaling, a more diverse and abundant cytokine profile and more CD8 T cells in KPCB PDAC, suggesting sensitivity to immune checkpoint blockade (ICB). However, ICB was ineffective in KPCB mice as a single agent or in combination with PARP inhibition. Based on our transcriptomic data, we hypothesized that boosting antigen priming using a CD40 agonist (CD40a) in combination with FLT3-L may improve ICB efficacy in our mouse models of BRCAness. Immunotherapy consisting of combined ICB, CD40a and FLT-3L had little efficacy in either KPCA or KPCB mice. However, ATR inhibition improved the efficacy of combined ICB, CD40a and FLT-3L in KPCA mice, as indicated by increased CD8 T cell infiltration in the tumor, delayed tumor growth and longer survival. In contrast, we found that PARP inhibition combined with ICB, CD40a and FLT-3L was ineffective in KPCB mice. In summary, we present evidence to suggest that PDAC characterized by BRCAness is not a homogeneous group with respect to sensitivity to PARP inhibition, composition of the tumor microenvironment and response to immunotherapy. We highlight ATM loss as a potential predictive biomarker of ATR inhibitor efficacy and immunotherapy in PDAC. Future directions include the evaluation of inflammation as a therapeutic vulnerability in murine PDAC with loss of Brca1. Ultimately, we aim to inform clinical trials to refine precision medicine of PDAC characterized by BRCAness. Citation Format: Mathias Tesson, Kay Kong, Peter Repsicak, Aldo Bader, Ya-Ching Hsieh, Craig Nourse, Kristina Kirschner, Crispin Miller, Ed Roberts, David Chang, Jen Morton. Identification of therapeutic vulnerabilities in the subset of pancreatic ductal adenocarcinoma (PDAC) with homologous recombination deficiency [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A031.

Abstract A040: Multiplex fluorescent immunohistochemistry reveals immunosuppressive tumor microenvironment in COMPASS-like complex gene mutated pancreatic cancer

Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) is highly resistant to chemoradiation and immune therapies. There is limited biomarker to identify subsets of PDAC that responds to immunotherapy or targeted therapy. We have identified a subset of PDACs (approximately 25%) carrying COMPASS-like complex (CLC) gene mutations. Analysis of the clinicopathologic and molecular features of this PDAC subset revealed that these tumors are an aggressive group of PDACs with poor or squamous histologic differentiation, increased rates of TP53 mutations, and poor patient survival compared to control PDACs. Our preliminary data showed that PDACs carrying mutations in two members of the CLC genes (KDM6A and KMT2D) have immunosuppressive tumor microenvironment (TME), suggesting that CLC genes are candidate biomarkers for immunotherapy. However, a comprehensive analysis of the immune composition, immune checkpoint expression, and the relationship between tumor cells and immune cells in CLC gene mutated PDACs compared to controls has not been performed. In this study, we characterized the immune composition in CLC gene mutated PDACs compared to paired control PDACs using tyramide signal amplification multiplex fluorescent immunohistochemistry (mfIHC). Methods: Human PDAC tissue slides were stained with 2 mfIHC panels and cell types were defined by different markers: panel 1 (PanCK, CD163, PD-L1, CD3, CD8, FoxP3) and panel 2 (PanCK, CD163, CD3, CD8, TIGIT, TIM3). Random image sections were selected in each sample (5∼8 sections per sample) and divided into wild-type (WT) group (n=57) and mutant group (n=41) and analyzed using InForm Cell Analysis software. Tissue segmentation training was performed to separate stromal and epithelial elements. Cell percentage, cell density, and nearest neighbor distance of each cell type were calculated using R program. Results: The CLC gene mutation is associated with elevated epithelial cells (ECs) and PDL1+ ECs and increased infiltration of exhausted cytotoxic T cells (TIGIT+/TIM3+ CD8 T cells). CLC gene mutated PDACs are characterized by spatial proximity between exhausted T cells (TIGIT+) and epithelial cells/antigen presenting cells (APCs). Higher number of epithelial cells is associated with reduced infiltration of helper T cells in the mutant PDAC tissue. We also observed that high numbers of APC in proximity to CD4 T cells were positively correlated with the proximity of EC and CD8 cytotoxic T cells as well as the proximity of CD4 T cells and cytotoxic T cells in the WT group but not in the CLC gene mutant group. Conclusion: Our results provide insight into the effects of CLC gene mutations on shaping the immune microenvironment of PDAC and suggest that CLC gene mutated PDACs have an immunosuppressive immune microenvironment than other PDACs and may respond differently to immunotherapy. Citation Format: Shungang Zhang, Elaina Daniels, Jake McGue, Hong Sun Kim, Dafydd Thomas, Timothy Frankel, Jiaqi Shi. Multiplex fluorescent immunohistochemistry reveals immunosuppressive tumor microenvironment in COMPASS-like complex gene mutated pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A040.

A multicenter, randomized, non-comparative, phase II study of nivolumab ± ipilimumab for patients with metastatic sarcoma (Alliance A091401): expansion cohorts and correlative analyses

BackgroundIn this open-label, randomized, non-comparative, multicenter phase II study (Alliance A091401) we report on three expansion cohorts treated with nivolumab (N) with and without ipilimumab (N+I) and provide a multi-omic...

Re-analysis of single cell and spatial transcriptomics data reveals B cell landscape in gastric cancer microenvironment and its potential crosstalk with tumor cells for clinical prognosis

BackgroundAt present, immunotherapy has become a powerful treatment for advanced gastric cancer (AGC), but not all patients can benefit from it. According to the latest research, the impact of B cell subpopulations on the immune microenvironment of gastric cancer (GC) is unknown. Exploring whether the interaction between B cells and tumor cells in GC affects the effectiveness of immunotherapy has attracted our interest.MethodsThis study involved the re-analysis of single-cell RNA (scRNA) and spatial transcriptomics (ST) data from publicly available datasets. The focus was on investigating the subpopulations and differentiation trajectories of B cells in the gastric cancer (GC) tumor immune microenvironment (TIME). Spatial transcriptomics (ST) and multiple immunofluorescence (mIF) revealed a clear co-localization pattern between B cells and tumor cells. Multiple immunotherapy datasets were collected to identify unique immunotherapy biomarkers. The unique immunotherapeutic potential of targeting CCL28 was validated through a mouse gastric cancer model. In addition, flow cytometry revealed changes in the tumor immune microenvironment targeting CCL28.ResultsThe re-analysis of ST data from multiple cancer types revealed a co-localization pattern between B cells and tumor cells. A significant number of IgA plasma cells were identified in the GC TIME. Five different tumor-infiltrating B cell subpopulations and two unique B cell differentiation trajectories were characterized, along with seven GC-related states. By analyzing the communication between GC cells and B cells, it was further discovered that tumor cells can influence and recruit plasma cells through CCL28-CCR10 signaling. Additionally, there was a crosstalk between GC cells and B cells. Finally, we identified the LAMA/CD44 signaling axis as a potential prognostic marker for immunotherapy through a large amount of immunotherapy data. We also validated through various animal tumor models that targeting CCL28 can significantly promote CD8+T cell infiltration and function in the TME by regulating B cell and plasma cell functions, and has the ability to synergize immunotherapy.ConclusionThe co-localization and crosstalk between GC cells and B cells significantly affect the efficacy of immunotherapy, and inhibiting the CCL28-CCR10 signal axis is a potential immunotherapy target for GC. Meanwhile, LAMA/CD44 pair may be a potential adverse indicator for immunotherapy and tumor prognosis.

A Peptide Microarray Platform Approach for Discovery of Immunodominant Antibody Epitopes.

Immunodominant epitope discovery platforms play an important role in identifying novel biomarkers for effective immunotherapies and diagnostics. Methods to analyze the B-cell repertoire have been improved both experimentally and computationally. We developed an enhanced peptide microarray platform to discover and subsequently screen immunodominant epitopes. We utilized SARS-Cov-2 IgG positive and negative samples as a proof-of-concept to demonstrate the power of these improved peptide microarrays. The method identified significantly discriminant epitopes that classify positive and negative samples with good performance both as single peptides and in combination. We provide the assay conditions and parameters that justify the use of peptide microarrays in the selection of high-affinity epitopes, and we directly compare peptide performance against proteins. The results suggest that this platform can be used to confidently identify immunodominant antiviral epitopes while also serving as a useful tool for high-volume screening.

Genomic landscape of malignant phyllodes tumors reveals multiple targetable opportunities.

Malignant phyllodes tumors (MPT) are rare fibroepithelial breast cancers with no known effective systemic therapy; metastatic progression portends a dismal prognosis. We sought to describe the genomic landscape of MPTs through genomic profiling and immunotherapeutic biomarker analysis. Cases of sequenced MPT were identified from a Clinical Laboratory Improvement Amendments-certified, College of American Pathologists-accredited laboratory (Foundation Medicine). All cases underwent genomic profiling using adaptor ligation-based, next-generation sequencing assay of 324 genes. Tumor agnostic immunotherapy biomarkers, microsatellite instability, tumor mutational burden (TMB), and programmed death-ligand 1 (PD-L1) expression were evaluated. Fisher's Exact Tests and analysis of variance were used to test for differences between groups and for continuous variables as appropriate. Of 135 MPT cases identified; 94 (69.6%) were localized/locally recurrent and 41 (30.4%) were metastatic. Median age was 54 years (range 14-86). The median TMB was 2.5 mut/Mb and 3 were TMB-high (≥10 mut/Mb). 21.4% were PD-L1+ via Dako 22C3 assay (CPS ≥1). Most commonly altered genes included TERT-promoter (69.7%), CDKN2A (45.9%), TP53 (37.8%), NF1 (35.6%), CDKN2B (33.3%), MED12 (28.9%), MTAP (27.7%), KMT2D (22.2%), PIK3CA (20.0%), PTEN (18.5%), and RB1 (18.5%). Several tumors harboring genomic alterations with US Food and Drug Administration-approved indications in other tumor types were found including NF1, PIK3CA, EGFR Exon 19/20 insertions, and BRAF V600E mutations. In the largest genomic evaluation of MPT to date, multiple clinically actionable mutations were found. Routine sequencing of metastatic MPT may provide additional information to guide treatment decisions and clinical trial enrollment.

SLC8A1, a novel prognostic biomarker and immunotherapy target in RSA and UCEC based on scRNA-seq and pan-cancer analysis

BackgroundThe field of gynaecological immunology has increasingly focused on recurrent spontaneous abortion (RSA). The complex mechanisms underlying the interaction between RSA and cancer are not well understood. MethodsWeighted gene coexpression network analysis (WGCNA), single-cell RNA sequencing (scRNA-seq), and machine learning algorithms were used for the analysis of RSA decidua samples to identify the hub genes. The expression and distribution of the hub genes were subsequently investigated via the pancancer database TCGA. A prognostic prediction was made to assess the impact of the hub genes on the cancer response, mutation burden, immune microenvironment, immune checkpoint, and chemotherapy. In vitro assays were performed to determine whether SLC8A1 influences HTR-8/SVneo cell proliferation, apoptosis and the concentration of calcium ions. ResultsSLC8A1 was identified as a hub gene within RSA and was highly expressed in uterine corpus endometrial carcinoma (UCEC). The efficacy of SLC8A1 as a predictive marker was substantiated by calibration curves and the concordance index. The mutation rate of SLC8A1 was found to be 6 % on the basis of the waterfall plot. Immune analysis revealed notable differences in the fractions of T cells and macrophages between the high- and low-expression groups. Patients classified in the low-risk group exhibited enhanced responsiveness to osimertinib, dasatinib, and ibrutinib. The results of in vitro experiments revealed that SLC8A1 promotes proliferation and inhibits the apoptosis and concentration of calcium ions in HTR-8/SVneo cells. ConclusionThese findings suggest that SLC8A1 may serve as a promising prognostic biomarker and potential target for immunotherapy in the context of RSA and UCEC.

DNA Vaccines Encoding HTNV GP-Derived Th Epitopes Benefited from a LAMP-Targeting Strategy and Established Cellular Immunoprotection.

Vaccines has long been the focus of antiviral immunotherapy research. Viral epitopes are thought to be useful biomarkers for immunotherapy (both antibody-based and cellular). In this study, we designed a novel vaccine molecule, the Hantaan virus (HTNV) glycoprotein (GP) tandem Th epitope molecule (named the Gnc molecule), in silico. Subsequently, computer analysis was used to conduct a comprehensive and in-depth study of the various properties of the molecule and its effects as a vaccine molecule in the body. The Gnc molecule was designed for DNA vaccines and optimized with a lysosomal-targeting membrane protein (LAMP) strategy. The effects of GP-derived Th epitopes and multiepitope vaccines were initially verified in animals. Our research has resulted in the design of two vaccines based on effective antiviral immune targets. The effectiveness of molecular therapies has also been preliminarily demonstrated in silico and in laboratory animals, which lays a foundation for the application of a vaccines strategy in the field of antivirals.

Analysis of proliferating Treg cells as a predictor for immunotherapy response using systemic longitudinal immune profiling: Biomarker analysis of the phase 3 CONTINUUM trial.

140 Background: The discovery of predictive biomarkers for immunotherapy is hindered by the lack of control groups in most translational studies, making it impossible to discern whether the identified biomarkers are merely prognostic or truly predictive for treatment outcomes. This study reported on prospectively designed biomarker analyses of the phase 3 CONTINNUUM trial (NCT03700476), the first trial that demonstrated prolonged event-free survival (EFS) with the addition of anti-PD-1 (aPD1) to chemoradiotherapy (CRT) in locoregionally-advanced nasopharyngeal carcinoma (LA-NPC). Methods: Mass cytometry was performed to generate a dynamic single-cell atlas on longitudinal peripheral blood mononuclear cell (PBMC) samples from 12 pairs of matched patients with or without relapse in the aPD1-CRT arm. The machine-learning algorithm CellCnn was applied to identify a cell subset that was most strongly associated with disease relapse, which was further confirmed by flow cytometry (n = 120). Single-cell RNA sequencing data from matched PBMC and tumor samples were analyzed and multiplex immunohistochemistry was performed on baseline tumor samples (n = 249) to verify the predictive value of the cell subset within tumors. Results: Baseline circulating regulatory T cells (Tregs), with a Ki67+ proliferating phenotype, were found to display a higher frequency in LA-NPC patients who developed posttreatment relapse ( P < 0.001), which was further validated by flow cytometry. The intratumoral Ki67+ Tregs were also identified and correlated with an immunosuppressive tumor microenvironment. In patients with a low baseline level of Ki67+ Tregs, additional aPD1 significantly improved EFS compared with CRT alone (log-rank P = 0.011, HR = 0.22, 95% CI: 0.06−0.79), while EFS was almost identical in both treatment arms in patients with high Ki67+ Treg levels (log-rank P = 0.995, HR = 1.00, 95% CI: 0.49−2.05; interaction P = 0.047). This predictive value was further validated in datasets from two independent randomized trials in renal cancer. Conclusions: The frequency of Ki67+ Tregs can serve as a reliable predictive tool in selecting patients who are more likely to benefit from immunotherapy, potentially informing individualized immunotherapy strategies.

Identification of RNA-binding protein RBMS3 as a potential biomarker for immunotherapy in bladder cancer.

RNA-binding protein (RBP) plays pivotal roles in the malignant progression of cancer by regulating gene expression. In this paper, we aimed to develop RBP-based prognostic signature and identify critical hub RBPs in bladder cancer (BLCA). Firstly, a risk model based on differentially expressed RBP gens (DERBPs) between normal and tumor tissues was successfully established, which can predict the tumor stromal score and drug sensitivity. Then two another RBP risk models based on miRNA-correlated RBPs or lncRNA-correlated RBPs were also established, and RBMS3 was identified as the overlapping gene in the three models. Data from multiple bioinformatics databases revealed that RBMS3 was an independent prognostic factor for overall survival (OS), and was associated with an immunosuppressive tumor microenvironment (TME) in BLCA. Further, Single-cell RNA-Seq (scRNA-Seq) data and the human protein altas (HPA) database showed that RBMS3 expression (both mRNA and protein) were up-regulated in BLCA tumor and tumor stromal cells. Finally, RBMS3 was shown to be associated with worse response to BLCA immunotherapy. Overall, RBMS3 is a key prognostic RBP with TME remodeling function and may serve as a target for BLCA immunotherapy.

Combined Transcriptome and Circulating Tumor DNA Longitudinal Biomarker Analysis Associates With Clinical Outcomes in Advanced Solid Tumors Treated With Pembrolizumab.

Immune gene expression signatures are emerging as potential biomarkers for immunotherapy (IO). VIGex is a 12-gene expression classifier developed in both nCounter (Nanostring) and RNA sequencing (RNA-seq) assays and analytically validated across laboratories. VIGex classifies tumor samples into hot, intermediate-cold (I-Cold), and cold subgroups. VIGex-Hot has been associated with better IO treatment outcomes. Here, we investigated the performance of VIGex and other IO biomarkers in an independent data set of patients treated with pembrolizumab in the INSPIRE phase II clinical trial (ClinicalTrials.gov identifier: NCT02644369). Patients with advanced solid tumors were treated with pembrolizumab 200 mg IV once every 3 weeks. Tumor RNA-seq data from baseline tumor samples were classified by the VIGex algorithm. Circulating tumor DNA (ctDNA) was measured at baseline and start of cycle 3 using the bespoke Signatera assay. VIGex-Hot was compared with VIGex I-Cold + Cold and four groups were defined on the basis of the combination of VIGex subgroups and the change in ctDNA at cycle 3 from baseline (ΔctDNA). Seventy-six patients were enrolled, including 16 ovarian, 12 breast, 12 head and neck cancers, 10 melanoma, and 26 other tumor types. Objective response rate was 24% in VIGex-Hot and 10% in I-Cold/Cold. VIGex-Hot subgroup was associated with higher overall survival (OS) and progression-free survival (PFS) when included in a multivariable model adjusted for tumor type, tumor mutation burden, and PD-L1 immunohistochemistry. The addition of ΔctDNA improved the predictive performance of the baseline VIGex classification for both OS and PFS. Our data indicate that the addition of ΔctDNA to baseline VIGex may refine prediction for IO.

Five-year follow-up of neoadjuvant PD-1 inhibitor (sintilimab) in non-small cell lung cancer

BackgroundNeoadjuvant anti-programmed cell death protein-1 (PD-1) therapy exhibits potential in treating resectable non-small cell lung cancer (NSCLC). Previously, we have reported the 3-year clinical outcomes of this trial, implying the...

Peripheral immune biomarkers for immune checkpoint inhibition of solid tumours.

With the rapid adoption of immunotherapy for the treatment of cancer comes the pressing need for readily accessible biomarkers to guide immunotherapeutic strategies and offer insights into outcomes with specific treatments. Regular sampling of solid tumour tissues outside of melanoma for immune monitoring is not often feasible; conversely, routine, frequent interrogation of circulating immune biomarkers is entirely possible. As immunotherapies and immune checkpoint inhibitors, in particular, are more widely used in first-line, neoadjuvant, and metastatic settings, the discovery and validation of peripheral immune biomarkers are urgently needed across solid tumour types for improved prediction and prognostication of clinical outcomes in response to immunotherapy, as well as elucidation of mechanistic underpinnings of the intervention. Careful experimental design, encompassing both retrospective and prospective studies, is required in such biomarker identification studies, and concerted efforts are essential for their advancement into clinical settings. In this review, we summarize shared immune features between the tumour microenvironment and systemic circulation, evaluate exploratory peripheral immune biomarker studies, and discuss associations between candidate biomarkers with clinical outcomes. We also consider integration of multiple peripheral immune parameters for better prediction and prognostication and discuss considerations in study design to further evaluate the clinical utility of candidate peripheral immune biomarkers for immunotherapy of solid tumours. Peripheral immune biomarkers are critical for improved prediction and prognostication of clinical outcomes for patients with solid tumours treated with immune checkpoint inhibition. Candidate peripheral biomarkers, such as cytokines, soluble factors, and immune cells, have potential as biomarkers to guide immunotherapy of solid tumours. Multiple peripheral immune parameters may be integrated to improve prediction and prognostication. The potential of peripheral immune biomarkers to guide immunotherapy of solid tumours requires critical work in biomarker discovery, validation, and standardization.

RNF43 in cancer: Molecular understanding and clinical significance in immunotherapy.

Identifying biomarkers to predict immune checkpoint inhibitor (ICI) efficacy is warranted. Considering that somatic mutation-derived neoantigens induce strong immune responses, patients with a high tumor mutational burden reportedly tend to respond to ICIs. Therefore, the original function of neoantigenic mutations and their impact on the tumor microenvironment (TME) require attention. RNF43 is a type of RING E3 ubiquitin ligase, and long-term survivors in most cancers had conserved patterns of mutations of RNF43. Also, high microsatellite instability patients had a higher RNF43 mutation rate compared with microsatellite stability tumor patients, who were more sensitive to ICI treatment. Therefore, RNF43 has become a promising biomarker of immunotherapy in a wide range of cancers. This review focuses on the up-to-date knowledge of RNF43 mutation in cancer. We summarize the cancer hallmarks involving activities regulated by RNF43 and highlight its extremely sophisticated regulation of WNT signaling and tumor microenvironment. The key genes interacting with RNF43 have also been summarized and discussed. Additionally, we highlight and propose new strategies of targeting RNF43 and RNF43-based combinations with established immunotherapy and combination therapy. These efforts may provide new perspectives for RNF43-based target therapy in cancer.

SPOP expression is associated with tumor-infiltrating lymphocytes in pancreatic cancer.

Speckle Type POZ Protein (SPOP), despite its tumor type-dependent role in tumorigenesis, primarily as a tumor suppressor gene is associated with a variety of different cancers. However, its function in pancreatic cancer remains uncertain. SPOP expression and the association between its expression and patient prognosis and immune function were evaluated using The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx), The Tumor Immune Estimation Resource 2.0 (TIMER2.0) database, cBioportal, and various bioinformatic databases. Enrichment analysis of SPOP and the association between SPOP expression with clinical stage and grade were analyzed using the R software package. Then immunohistochemistry (IHC) was used to estimate the correlation between SPOP and tumor-infiltrating lymphocytes (TILs) in patients with pancreatic cancer. As part of our study, we assessed that SPOP was anomalously expressed in kinds of cancers, associated with clinical stage and outcomes. Meanwhile, SPOP also played a crucial role in the tumor microenvironment (TME). The expression level of SPOP was significantly correlated to tumor-infiltrating immune cells (TICs) in pancreatic cancer. Our study uncovered the potential corrections in SPOP with TICs, suggesting that SPOP may act as a biomarker for immunotherapy in pancreatic cancer.

ImmunoPET imaging of LAG-3 expression in tumor microenvironment with 68Ga-labelled cyclic peptides tracers: from bench to bedside

BackgroundLymphocyte activation gene 3 (LAG-3) has been considered as the next generation of immune checkpoint and a promising prognostic biomarker of immunotherapy. As with programmed cell death protein-1/programmed death-ligand 1...

A pilot study on the detection of microsatellite instability using long mononucleotide repeats in solid tumors.

Microsatellite instability (MSI) status is a prognostic biomarker for immunotherapy in certain types of cancers, such as colorectal cancers (CRCs) and endometrial cancers (ECs). Tumors that are categorized as having high MSI (MSI-H) express high levels of neoantigens for immune recognition. The typical MSI test measures the length of short mononucleotide repeats (SMR) poly(A) 21-27; however, a limitation of this test is the difficulty in determining the shift size, particularly in endometrial cancer. To investigate an MSI detection assay with improved performance, the present study analyzed the use of poly(A) 40-44 mononucleotide repeats to detect the MSI status of 100 patients with either CRC (n=50) or EC (n=50). Capillary electrophoresis was used to evaluate five long mononucleotide repeat (LMR) markers, including poly(A) 40-A, 40-B, 40-C, 40-D and 44. The concordance rate of the LMR-MSI assay compared with an immunohistochemistry MSI detection assay was 96.0 and 95.1% for CRCs and ECs respectively, with the detection limit of the LMR-MSI assay demonstrated to be 2.5% MSI-H in HCT116 colorectal carcinoma cell lines. The LMR-MSI assay yielded a 95.1% concordance rate in ECs compared with that in the SMR-MSI test (87.8%). The LMR-MSI test identified a significantly higher mean shift size (13 bp) in MSI-H tumors compared with the SMR-MSI test (10 bp), in both EC and CRC tissue samples. Together, the present study suggested that the LMR-MSI test could potentially be a sensitive and practical technology for molecular laboratory testing, particularly in the use of immunotherapy for patients with CRCs and ECs.

An integrated pan-cancer assessment of prognosis, immune infiltration, and immunotherapy response for B7 family using multi-omics data

AimsB7 molecules (B7s) are crucial synergistic signals for effective immune surveillance against tumor cells. While previous studies have explored the association between the B7 family and cancer, most have been limited to specific genes or cancer subtypes. Main methodsOur study utilized multi-omics data to investigate potential correlations between B7s expression (B7s exp.) and prognosis, clinicopathological features, somatic mutations (SMs), copy number variations (CNVs), immune characteristics, tumor microenvironment (TME), microsatellite instability, tumor mutation burden, immune checkpoint gene (ICG), and drug responsiveness in TCGA tumors. Furthermore, the connection between B7s exp. and immunotherapy (IT) performance assessed in various validated datasets. Following this, immune infiltration analysis (IIA) was conducted based on B7s exp., CNVs, or SMs in bladder cancer (BLCA), complemented by real-time PCR (RT-PCR) and protein confirmation of B7-H3. Key findingsAcross most cancer types, B7s exp. was related to prognosis, clinicopathological characteristics, mutations, CNVs, ICG, TMB, TME. The examination of sensitivity to anticancer drugs unveiled correlations between B7 molecules and different drug sensitivities. Specific B7s exp. patterns were linked to the clinical effectiveness of IT. Using GSEA, several enriched immune-related functions and pathways were identified. Particularly in BLCA, IIA revealed significant connections between B7 CNVs, mutation status, and various immune cell infiltrates. RT-PCR confirmed elevated B7-H3 gene levels in BLCA tumor tissues. SignificanceThis study confirmed the significance of B7s exp. and genomic changes in predicting outcomes and treatment across different cancer types. Moreover, they indicate a critical function of B7s in BLCA and their potential as IT biomarkers.

Molecular profiling of core immune-escape genes highlights TNFAIP3 as an immune-related prognostic biomarker in neuroblastoma.

Neuroblastoma (NB) is the most prevalent and deadliest pediatric solid tumor. With of over 50% of high-risk neuroblastoma cases relapse, the imperative for novel drug targets and therapeutic strategies is accentuated. In neuroblastoma, the existence of tumor-associated macrophages (TAMs) correlates with an unfavorable patient prognosis. However, the clinical relevance and prognostic implications of regulatory genes linked to TAMs infiltration in neuroblastoma remain unclear, and further study is required. We conducted a comprehensive analysis utilizing transcriptome expression profiles from three primary datasets associated with neuroblastoma (GSE45547, GSE49710, TARGET) to identify hub genes implicated in immune evasion within neuroblastoma. Subsequently, we utilized single-cell RNA sequencing analysis on 17 clinical neuroblastoma samples to investigate the expression and distribution of these hub genes, leading to the identification of TNFAIP3. The above three public databases were merged to allowed for the validation of TNFAIP3's molecular functions through GO and KEGG analysis. Furthermore, we assessed TNFAIP3's correlation with immune infiltration and its potential immunotherapeutic impact by multiple algorithms. Our single-cell transcriptome data revealed the role of TNFAIP3 in macrophage polarization. Finally, preliminary experimental verifications to confirm the biological functions of TNFAIP3-mediated TAMs in NB. A total of 6 genes related to immune evasion were screened and we found that TNFAIP3 exhibited notably higher expression in macrophages than other immune cell types, based on the scRNA-sequencing data. GO and KEGG analysis showed that low expression of TNFAIP3 significantly correlated with the activation of multiple oncogenic pathways as well as immune-related pathways. Then validation affirmed that individuals within the TNFAIP3 high-expression cohort could potentially derive greater advantages from immunotherapeutic interventions, alongside exhibiting heightened immune responsiveness. Deciphering the pseudotime trajectory of macrophages, we revealed the potential of TNFAIP3 in inducing the polarization of macrophages towards the M1 phenotype. Finally, we confirmed that patients in the TNFAIP3 high expression group might benefit more from immunotherapy or chemotherapy as substantiated by RT-qPCR and immunofluorescence examinations. Moreover, the role of TNFAIP3 in macrophage polarization was validated. Preliminary experiment showed that TNFAIP3-mediated TAMs inhibit the proliferation, migration and invasion capabilities of NB cells. Our results suggest that TNFAIP3 was first identified as a promising biomarker for immunotherapy and potential molecular target in NB. Besides, the presence of TNFAIP3 within TAMs may offer a novel therapeutic strategy for NB.

Mapping the genetic landscape establishing a tumor immune microenvironment favorable for anti-PD-1 response in mice and humans.

Identifying host genetic factors modulating immune checkpoint inhibitor (ICI) efficacy has been experimentally challenging because of variations in both host and tumor genomes, differences in the microbiome, and patient life exposures. Utilizing the Collaborative Cross (CC) multi-parent mouse genetic resource population, we developed an approach that fixes the tumor genomic configuration while varying host genetics. With this approach, we discovered that response to anti-PD-1 (aPD1) immunotherapy was significantly heritable in four distinct murine tumor models (H2 between 0.18-0.40). For the MC38 colorectal carcinoma system (H2 = 0.40), we mapped four significant ICI response quantitative trait loci (QTL) localized to mouse chromosomes (mChr) 5, 9, 15 and 17, and identified significant epistatic interactions between specific QTL pairs. Differentially expressed genes within these QTL were highly enriched for immune genes and pathways mediating allograft rejection and graft vs host disease. Using a cross species analytical approach, we found a core network of 48 genes within the four QTLs that showed significant prognostic value for overall survival in aPD1 treated human cohorts that outperformed all other existing validated immunotherapy biomarkers, especially in human tumors of the previously defined immune subtype 4. Functional blockade of two top candidate immune targets within the 48 gene network, GM-CSF and high affinity IL-2/IL-15 signaling, completely abrogated the MC38 tumor transcriptional response to aPD1 therapy in vivo. Thus, we have established a powerful cross species in vivo platform capable of uncovering host genetic factors that establish the tumor immune microenvironment configuration propitious for ICI response.