Heterogeneous Tumor-Immune Microenvironments among Differentially Growing Metastases in an Ovarian Cancer Patient

Nucleotide excision repair protein ERCC1 and tumour-infiltrating lymphocytes are potential biomarkers of neoadjuvant platinum resistance in high grade serous ovarian cancer

OBJECTIVE

ERCC1 is a nucleotide excision repair protein that may have a role in drug resistance in high grade serous ovarian cancer (HGSOC). We hypothesized that ERCC1 expression and tumour infiltrating lymphocytes (TILS) are induced by chemotherapy in HGSOC, which may be prognostically useful.

METHODS

115 HGSOC patients were used for this study. 92 (80%) of the tissue analysed had not been exposed to platinum chemotherapy. The remaining 20% (n = 23) of cases received combination or monotherapy with carboplatin before tissue was collected. Immunohistochemistry was used to score for ERCC1 expression and morphology to score for TILs. Correlation analysis of all clinical parameters, TILs and ERCC1 and Kaplan-Meier survival analysis was performed using the ERCC1 and TILs scoring parameters (0, 1, 2 or 3).

RESULTS

ERCC1 expression was 2-fold higher in the neoadjuvant chemotherapy group compared to the primary cytoreductive surgery group (p < 0.0001). The mean overall survival for the neoadjuvant group with high ERCC1 was 141.6 ± 20.2 months which was significantly longer than absent ERCC1 survival of 61 + 22.6 months (p = 0.028). ERCC1 score strongly correlated with TILs score across the whole cohort (0.349, p = 1.3 × 10^-4) suggesting there is a relationship between ERCC1 expression and TILs, but this requires further investigation.

CONCLUSION

In conclusion, ERCC1 was identified as a potential biomarker of platinum response overall survival in HGSOC undergoing neoadjuvant HGSOC treatment.

Regulation of Ovarian Cancer Prognosis by Immune Cells in the Tumor Microenvironment

It is estimated that in the United States in 2018 there will be 22,240 new cases of ovarian cancer and 14,070 deaths due to this malignancy. The most common subgroup of this disease is high-grade serous ovarian cancer (HGSOC), which is known for its aggressiveness, high recurrence rate, metastasis to other sites, and the development of resistance to conventional therapy. It is important to understand the ovarian cancer tumor microenvironment (TME) from the viewpoint of the function of pre-existing immune cells, as immunocompetent cells are crucial to mounting robust antitumor responses to prevent visible tumor lesions, disease progression, or recurrence. Networks consisting of innate and adaptive immune cells, metabolic pathways, intracellular signaling molecules, and a vast array of soluble factors, shape the pathogenic nature of the TME and are useful prognostic indicators of responses to conventional therapy and immunotherapy, and subsequent survival rates. This review highlights key immune cells and soluble molecules in the TME of ovarian cancer, which are important in the development of effective antitumor immunity, as well as those that impair effector T cell activity. A more insightful knowledge of the HGSOC TME will reveal potential immune biomarkers to aid in the early detection of this disease, as well as biomarkers that may be targeted to advance the design of novel therapies that induce potent antitumor immunity and survival benefit.

Regulation of Ovarian Cancer Prognosis by Immune Cells in the Tumor Microenvironment

It is estimated that in the United States in 2018 there will be 22,240 new cases of ovarian cancer and 14,070 deaths due to this malignancy. The most common subgroup of this disease is high-grade serous ovarian cancer (HGSOC), which is known for its aggressiveness, high recurrence rate, metastasis to other sites, and the development of resistance to conventional therapy. It is important to understand the ovarian cancer tumor microenvironment (TME) from the viewpoint of the function of pre-existing immune cells, as immunocompetent cells are crucial to mounting robust antitumor responses to prevent visible tumor lesions, disease progression, or recurrence. Networks consisting of innate and adaptive immune cells, metabolic pathways, intracellular signaling molecules, and a vast array of soluble factors, shape the pathogenic nature of the TME and are useful prognostic indicators of responses to conventional therapy and immunotherapy, and subsequent survival rates. This review highlights key immune cells and soluble molecules in the TME of ovarian cancer, which are important in the development of effective antitumor immunity, as well as those that impair effector T cell activity. A more insightful knowledge of the HGSOC TME will reveal potential immune biomarkers to aid in the early detection of this disease, as well as biomarkers that may be targeted to advance the design of novel therapies that induce potent antitumor immunity and survival benefit.

Regulation of Ovarian Cancer Prognosis by Immune Cells in the Tumor Microenvironment

It is estimated that in the United States in 2018 there will be 22,240 new cases of ovarian cancer and 14,070 deaths due to this malignancy. The most common subgroup of this disease is high-grade serous ovarian cancer (HGSOC), which is known for its aggressiveness, high recurrence rate, metastasis to other sites, and the development of resistance to conventional therapy. It is important to understand the ovarian cancer tumor microenvironment (TME) from the viewpoint of the function of pre-existing immune cells, as immunocompetent cells are crucial to mounting robust antitumor responses to prevent visible tumor lesions, disease progression, or recurrence. Networks consisting of innate and adaptive immune cells, metabolic pathways, intracellular signaling molecules, and a vast array of soluble factors, shape the pathogenic nature of the TME and are useful prognostic indicators of responses to conventional therapy and immunotherapy, and subsequent survival rates. This review highlights key immune cells and soluble molecules in the TME of ovarian cancer, which are important in the development of effective antitumor immunity, as well as those that impair effector T cell activity. A more insightful knowledge of the HGSOC TME will reveal potential immune biomarkers to aid in the early detection of this disease, as well as biomarkers that may be targeted to advance the design of novel therapies that induce potent antitumor immunity and survival benefit.

The molecular limitations of biomarker research in bladder cancer

PURPOSE

Urothelial carcinoma of the bladder (UCB) is a common malignancy with limited systemic treatment options in advanced stages. Despite recent advances in immunotherapy, the majority of patients do not respond to these treatments. There is an unmet need for developing robust biomarkers to inform treatment decisions and identify patients who are likely to respond.

METHODS

A MEDLINE/PubMed literature search was performed, focusing on tissue-based and circulating biomarkers, and their potential in muscle-invasive UCB.

RESULTS

UCB is a heterogeneous disease that consists of several clonal and subclonal populations, each with a mix of truncal and private genomic alterations. This inter- and intra-tumoral heterogeneous landscape results in the development of treatment resistance. Tumor heterogeneity also constitutes a barrier to the development of robust markers of response and resistance to chemotherapy and immunotherapy. Defects in DNA repair genes and a high tumor mutational burden independently confer sensitivity to cisplatin-based chemotherapy and checkpoint inhibitors. Oncogenic alterations such as FGFR3 mutations and fusions are associated with response to FGFR3 inhibitors. Several emerging potential biomarkers, including gene expression-based molecular subtypes, T-cell receptor clonality, and tissue- or blood-based immune-gene profiling, require prospective testing and validation. Tissue-based biomarkers such as PD-L1 immunohistochemistry have several limitations due to discordance in assay methodology and trial designs. Novel liquid-biopsy techniques are promising as potential biomarkers.

CONCLUSIONS

Validated biomarkers that capture the complexity of the biology of both the tumor and the tumor microenvironment are needed in muscle-invasive UCB. Standardization of methods is critical to developing reliable biomarkers to guide clinical management.

Targeting the Microenvironment in High Grade Serous Ovarian Cancer

Cancer⁻stroma interactions play a key role in cancer progression and response to standard chemotherapy. Here, we provide a summary of the mechanisms by which the major cellular components of the ovarian cancer (OC) tumor microenvironment (TME) including cancer-associated fibroblasts (CAFs), myeloid, immune, endothelial, and mesothelial cells potentiate cancer progression. High-grade serous ovarian cancer (HGSOC) is characterized by a pro-inflammatory and angiogenic signature. This profile is correlated with clinical outcomes and can be a target for therapy. Accumulation of malignant ascites in the peritoneal cavity allows for secreted factors to fuel paracrine and autocrine circuits that augment cancer cell proliferation and invasiveness. Adhesion of cancer cells to the mesothelial matrix promotes peritoneal tumor dissemination and represents another attractive target to prevent metastasis. The immunosuppressed tumor milieu of HGSOC is permissive for tumor growth and can be modulated therapeutically. Results of emerging preclinical and clinical trials testing TME-modulating therapeutics for the treatment of OC are highlighted.

Immunogenomic Analyses of Advanced Serous Ovarian Cancer Reveal Immune Score is a Strong Prognostic Factor and an Indicator of Chemosensitivity

Purpose: Ovarian cancer is one of the first human cancers for which in situ immune response was reported to be important for the clinical outcome. To elucidate the mechanistic relationship between immune repertoire and cancer genotype in ovarian cancer, the development of a well-defined immune score for ovarian cancer is required.Experimental Design: From a collection of 2,203 patient samples of advanced ovarian cancer from public available resources, we evaluated the prognostic values for a compendium of immune marker genes and proposed an immune score. The relationships between immune score, tumor-infiltrating immune cells, cancer genotypes, and their impact on patient outcome were characterized.Results: Loss of chemokine and IFNγ pathway genes is frequent in ovarian cancer and is significantly associated with low immune score and poor outcome. Chemotherapy can increase the immune score of tumors by inducing the expression of IFNγ inducible chemokines. High immune score is significantly associated with BRCA1/2 mutation status and the response to chemotherapy. Multivariate analysis revealed that immune score is a strong predictor of patient survival and the response to immunotherapy.Conclusions: Our results reveal the drivers of the immune repertoire of advanced ovarian cancer and demonstrate the importance of immune score as an independent prognostic signature and a potent indicator of intratumoral immune status. Clin Cancer Res; 24(15); 3560-71. ©2018 AACR.

Metastatic niche functions and therapeutic opportunities

Metastasis is an inefficient process, especially during colonization at a distant organ. This bottleneck underlies the importance of the metastatic niche for seeding and outgrowth of metastases. Here, we classify the common functions of different metastatic niches: anchorage, survival support, protection from external insults, licensing proliferation and outgrowth. We highlight the emerging role of the metastatic niche in maintaining cancer stemness and promoting immune evasion, and discuss therapeutic opportunities against the metastatic niche.

Ovarian Cancer Immunotherapy: Preclinical Models and Emerging Therapeutics

Immunotherapy has emerged as one of the most promising approaches for ovarian cancer treatment. The tumor microenvironment (TME) is a key factor to consider when stimulating antitumoral responses as it consists largely of tumor promoting immunosuppressive cell types that attenuate antitumor immunity. As our understanding of the determinants of the TME composition grows, we have begun to appreciate the need to address both inter- and intra-tumor heterogeneity, mutation/neoantigen burden, immune landscape, and stromal cell contributions. The majority of immunotherapy studies in ovarian cancer have been performed using the well-characterized murine ID8 ovarian carcinoma model. Numerous other animal models of ovarian cancer exist, but have been underutilized because of their narrow initial characterizations in this context. Here, we describe animal models that may be untapped resources for the immunotherapy field because of their shared genomic alterations and histopathology with human ovarian cancer. We also shed light on the strengths and limitations of these models, and the knowledge gaps that need to be addressed to enhance the utility of preclinical models for testing novel immunotherapeutic approaches.

Tumor-associated macrophages promote the metastasis of ovarian carcinoma cells by enhancing CXCL16/CXCR6 expression

This study investigated the underlying mechanism by which C-X-C motif chemokine ligand 16 (CXCL16)/C-X-C motif chemokine receptor 6 (CXCR6) signaling is activated by tumor-associated macrophages and assists in regulating the metastasis of ovarian carcinoma. Specimens of ovarian carcinoma tissue and adjacent tissue were collected from 20 ovarian carcinoma patients. Human THP-1 cells were induced to differentiate into macrophages, which were then co-cultured with SKOV3 cells and low concentrations of tumor necrosis factor-α (TNF-α) to simulate the inflammatory microenvironment of ovarian carcinoma. Additionally, small interfering RNA (siRNA) targeting CXCR6 was transfected into SKOV3 cells; after which, the levels of nuclear factor kappa B p65 (NF-κB p65) protein and phosphorylated PI3K and Akt were measured. The migration and invasion abilities of the SKOV3 cells were also tested. The levels of TNF-α, interluekin-6 (IL-6), NF-κB p65, CXCL16, and CXCR6 expression in the ovarian carcinoma tissues were higher than those in the precancerous tissues. CXCR6 expression was positively correlated with TNF-α, IL-6, and CXCL16 expression. Co-culture of SKOV3 cells with macrophages significantly promoted CXCL16, CXCR6, NF-κB, and p65 expression by the SKOV3 cells, increased their levels of phosphorylated PI3K and Akt, and increased the migration and invasion abilities of SKOV3 cells. Silencing of CXCR6 or blocking the PI3K/Akt signal pathway markedly attenuated the expression of NF-κB p65 and phosphorylation of PI3K and Akt, as well as the migration and invasion abilities of SKOV3 cells. These findings demonstrate that macrophages can promote the migration and invasion of ovarian carcinoma cells by affecting the CXCL16/CXCR6 pathway.

Single-Cell Map of Diverse Immune Phenotypes in the Breast Tumor Microenvironment

Knowledge of immune cell phenotypes in the tumor microenvironment is essential for understanding mechanisms of cancer progression and immunotherapy response. We profiled 45,000 immune cells from eight breast carcinomas, as well as matched normal breast tissue, blood, and lymph nodes, using single-cell RNA-seq. We developed a preprocessing pipeline, SEQC, and a Bayesian clustering and normalization method, Biscuit, to address computational challenges inherent to single-cell data. Despite significant similarity between normal and tumor tissue-resident immune cells, we observed continuous phenotypic expansions specific to the tumor microenvironment. Analysis of paired single-cell RNA and T cell receptor (TCR) sequencing data from 27,000 additional T cells revealed the combinatorial impact of TCR utilization on phenotypic diversity. Our results support a model of continuous activation in T cells and do not comport with the macrophage polarization model in cancer. Our results have important implications for characterizing tumor-infiltrating immune cells.

Targeting the Immune Microenvironment in Acute Myeloid Leukemia: A Focus on T Cell Immunity

Immunotherapies, such as chimeric antigen receptor T cells, bispecific antibodies, and immune checkpoint inhibitors, have emerged as promising modalities in multiple hematologic malignancies. Despite the excitement surrounding immunotherapy, it is currently not possible to predict which patients will respond. Within solid tumors, the status of the immune microenvironment provides valuable insight regarding potential responses to immune therapies. Much less is known about the immune microenvironment within hematologic malignancies but the characteristics of this environment are likely to serve a similar predictive role. Acute myeloid leukemia (AML) is the most common hematologic malignancy in adults, and only 25% of patients are alive 5 years following their diagnosis. There is evidence that manipulation of the immune microenvironment by leukemia cells may play a role in promoting therapy resistance and disease relapse. In addition, it has long been documented that through modulation of the immune system following allogeneic bone marrow transplant, AML can be cured, even in patients with the highest risk disease. These concepts, along with the poor prognosis associated with this disease, have encouraged many groups to start exploring the utility of novel immune therapies in AML. While the implementation of these therapies into clinical trials for AML has been supported by preclinical rationale, many questions still exist surrounding their efficacy, tolerability, and the overall optimal approach. In this review, we discuss what is known about the immune microenvironment within AML with a specific focus on T cells and checkpoints, along with their implications for immune therapies.

Immunotherapy in non-small-cell lung cancer: a bridge between research and clinical practice

Lung cancer has been historically considered a poorly immunogenic disease because of the few evidence of immune responses in affected patients and the limited efficacy of immunomodulating strategies. Recent understanding of the molecular mechanisms leading to cancer immune evasion has allowed the development of a new class of drugs called immune checkpoint inhibitors, which reactivate host responses with outstanding clinical benefits in a portion of patients with non-small-cell lung cancer. In this review, we briefly summarize the basis of immunogenicity and immune escape of cancer, with specific focus on non-small-cell lung cancer, mechanisms underlying immune checkpoint inhibitors efficacy and the most updated results on potential biomarkers, with the final aim of defining current unmet needs of immunotherapy in clinical practice.

A Functional Homologous Recombination Assay Predicts Primary Chemotherapy Response and Long-Term Survival in Ovarian Cancer Patients

Purpose: Homologous recombination deficiency (HRD) correlates with platinum sensitivity in patients with ovarian cancer, which clinically is the most useful predictor of sensitivity to PARPi. To date, there are no reliable diagnostic tools to anticipate response to platinum-based chemotherapy, thus we aimed to develop an ex vivo functional HRD detection test that could predict both platinum-sensitivity and patient eligibility to targeted drug treatments.Experimental Design: We obtained a functional HR score by quantifying homologous recombination (HR) repair after ionizing radiation-induced DNA damage in primary ovarian cancer samples (n = 32). Samples clustered in 3 categories: HR-deficient, HR-low, and HR-proficient. We analyzed the HR score association with platinum sensitivity and treatment response, platinum-free interval (PFI) and overall survival (OS), and compared it with other clinical parameters. In parallel, we performed DNA-sequencing of HR genes to assess if functional HRD can be predicted by currently offered genetic screening.Results: Low HR scores predicted primary platinum sensitivity with high statistical significance (P = 0.0103), associated with longer PFI (HR-deficient vs. HR-proficient: 531 vs. 53 days), and significantly correlated with improved OS (HR score <35 vs. ≥35, hazard ratio = 0.08, P = 0.0116). At the genomic level, we identified a few unclear mutations in HR genes and the mutational signature associated with HRD, but, overall, genetic screening failed to predict functional HRD.Conclusions: We developed an ex vivo assay that detects tumor functional HRD and an HR score able to predict platinum sensitivity, which holds the clinically relevant potential to become the routine companion diagnostic in the management of patients with ovarian cancer. Clin Cancer Res; 24(18); 4482-93. ©2018 AACR.

Influence of CA125, platelet count and neutrophil to lymphocyte ratio on the immune system of ovarian cancer patients

OBJECTIVE

The effect of CA125, neutrophil to lymphocyte ratio (NLR) and thrombocytosis on survival has been studied in ovarian cancer. This study explores the link between these variables and serum markers of ovarian cancer patients, such as signaling proteins and cytokines.

METHODS

Serum samples of 39 patients with high-grade serous ovarian cancer (HGSOC) were collected at diagnosis and were retrospectively analysed for clinical characteristics, clinical parameters (NLR, CA125, platelet count) and immune profile [IL-4 (interleukin), IL-10, IL-13, IL-17, transforming growth factor-β, Arginase-1, Interferon gamma), vascular endothelial growth factor (VEGF), galectin-1 and chemokine (C-C) motif ligand 2.

RESULTS

CA125 correlates negatively with VEGF (p = 0.02) and if CA125 rises above 500 kU/L, IL-10 is significantly increased (p = 0.01). NLR > 6 (p < 0.01) was significantly correlated with decreased overall survival. Thrombocytosis was significantly correlated with IL-10 (p < 0.01) and a platelet count > 400 × 10⁹/l led to an improvement in progression free survival (p < 0.01).

CONCLUSIONS

A correlation, at the time of diagnosis, of HGSOC between CA125, NLR and thrombocytes and an immunosuppressive cytokine-profile in serum is shown, and correlates with survival.

Prognosis of ovarian cancer is associated with effector memory CD8+ T cell accumulation in ascites, CXCL9 levels and activation-triggered signal transduction in T cells

The accumulation of intratumoral CD8⁺ T cells is associated with the survival of high grade serous ovarian carcinoma patients, but it is unclear which CD8⁺ T cell subsets contribute to this effect and how they are affected by the peritoneal tumor microenvironment. Here, we provide evidence for a functional link between long relapse-free survival, accumulation of CD8⁺ effector memory T (T_EM) cells in peritoneal effusion (ascites), and the level of the CD8⁺ T_EM attracting chemokine CXCL9, produced by macrophages as a major source. We also propose a novel mechanism by which the tumor microenvironment could contribute to T cell dysfunction and shorter survival, i.e., diminished expression levels of essential signaling proteins, including STAT5B, PLCγ1 and NFATc2. CD8⁺ T_EM cells in ascites, CXCL9 levels and the expression of crucial signal transduction proteins may therefore be important biomarkers to gauge the efficiency of immune therapies and potentially represent therapeutic targets.

Emerging Concepts for Immune Checkpoint Blockade-Based Combination Therapies

Checkpoint blockade has formally demonstrated that reactivating anti-tumor immune responses can regress tumors. However, this only occurs in a fraction of patients. Incorporating these therapies in more powerful combinations is thus a logical next step. Here, we review functional roles of immune checkpoints and molecular determinants of checkpoint-blockade clinical activity. Limited-size T cell-infiltrated tumors, differing substantially from "self," generally respond to checkpoint blockade. Therefore, we propose that reducing tumor burden and increasing tumor immunogenicity are key factors to improve immunotherapy. Lastly, we outline criteria to select proper immunotherapy combination partners and highlight the importance of activity biomarkers for timely treatment optimization.

Circulating programmed death ligand-1 (cPD-L1) in non-small-cell lung cancer (NSCLC)

Background

This study aimed at investigating feasibility of programmed death ligand-1 (PD-L1) testing in plasma samples of advanced NSCLC patients receiving first-line treatment, assessing whether circulating (c)PD-L1 levels were modified by the therapy and whether baseline cPD-L1 levels were associated with patients’ clinical responses and survival outcome.

Methods

Peripheral blood samples were collected from 16 healthy volunteers and 56 newly diagnosed NSCLC patients before and at 12th week during the course of first-line therapy. The level of PD-L1 was measured in plasma samples using the human (PD-L1/CD274) ELISA kit (CUSABIO, MD, USA). The Mann Whitney test or Fisher’s test were used for comparisons. Survival analysis was performed using Kaplan Meyer method, providing median and p-value.

Results

Baseline median cPD-L1 was 42.21 pg/ml (range 12.00-143.49) in NSCLC patients and 37.81 pg/ml (range 9.73-90.21) in healthy control cohort (p = 0.78). Median cPD-L1 increased in patients treated with first-line chemotherapy (63.20 pg/ml vs 39.34 pg/ml; p = 0.002), with no changes in patients exposed to non-chemotherapy drugs (42.39 pg/ml vs 50.67 pg/ml; p = 0.398). Time to progression and overall survival were 4.4 vs 6.9 months (p = 0.062) and 8.8 vs 9.3 months (p = 0.216) in cPD-L1 positive vs cPD-L1 negative patients. Baseline cPD-L1 levels increased with the ascending number of metastatic sites, even if the association was not statistically significant (p = 0.063).

Conclusions

This study showed that cPD-L1 testing is feasible, with chemotherapy influencing PD-L1 plasma levels. The possibility of using such test for predicting or monitoring the effect of immunotherapy or combination of chemotherapy and immunotherapy warrant further investigations.

Combination Cancer Therapy with Immune Checkpoint Blockade: Mechanisms and Strategies

The success of immune checkpoint blockade in patients with a wide variety of malignancies has changed the treatment paradigm in oncology. However, combination therapies with immune checkpoint blockade will be needed to overcome resistance and broaden the clinical utility of immunotherapy. Here we discuss a framework for rationally designing combination therapy strategies based on enhancing major discriminatory functions of the immune system that are corrupted by cancer-namely, antigenicity, adjuvanticity, and homeostatic feedback inhibition. We review recent advances on how conventional genotoxic cancer therapies, molecularly targeted therapies, epigenetic agents, and immune checkpoint inhibitors can restore these discriminatory functions. Potential barriers that can impede response despite combination therapy are also discussed.

The RNA binding protein SORBS2 suppresses metastatic colonization of ovarian cancer by stabilizing tumor-suppressive immunomodulatory transcripts

BACKGROUND

Ovarian cancer constitutes one of the most lethal gynecologic malignancies for females. Currently, early detection strategies and therapeutic options for ovarian cancer are far from satisfactory, leading to high diagnosis rates at late stages and disease relapses. New avenues of therapy are needed that target key processes in ovarian cancer progression. While a variety of non-coding RNAs have been proven to regulate ovarian cancer metastatic progression, the functional roles of RNA-binding proteins (RBPs) in this process are less well defined.

RESULTS

In this study, we identify that the RBP sorbin and SH3 domain containing 2 (SORBS2) is a potent suppressor of ovarian cancer metastatic colonization. Mechanistic studies show that SORBS2 binds the 3' untranslated regions (UTRs) of WFDC1 (WAP four-disulfide core domain 1) and IL-17D (Interleukin-17D), two secreted molecules that are shown to act as metastasis suppressors. Enhanced expression of either WFDC1 or IL-17D potently represses SORBS2 depletion-mediated cancer metastasis promotion. By enhancing the stability of these gene transcripts, SORBS2 suppresses ovarian cancer invasiveness and affects monocyte to myeloid-derived suppressor cell and M2-like macrophage polarization, eliciting a tumor-suppressive immune microenvironment.

CONCLUSIONS

Our data illustrate a novel post-transcriptional network that links cancer progression and immunomodulation within the tumor microenvironment through SORBS2-mediated transcript stabilization.

Prognosis of ovarian cancer is associated with effector memory CD8+ T cell accumulation in ascites, CXCL9 levels and activation-triggered signal transduction in T cells

The accumulation of intratumoral CD8⁺ T cells is associated with the survival of high grade serous ovarian carcinoma patients, but it is unclear which CD8⁺ T cell subsets contribute to this effect and how they are affected by the peritoneal tumor microenvironment. Here, we provide evidence for a functional link between long relapse-free survival, accumulation of CD8⁺ effector memory T (T_EM) cells in peritoneal effusion (ascites), and the level of the CD8⁺ T_EM attracting chemokine CXCL9, produced by macrophages as a major source. We also propose a novel mechanism by which the tumor microenvironment could contribute to T cell dysfunction and shorter survival, i.e., diminished expression levels of essential signaling proteins, including STAT5B, PLCγ1 and NFATc2. CD8⁺ T_EM cells in ascites, CXCL9 levels and the expression of crucial signal transduction proteins may therefore be important biomarkers to gauge the efficiency of immune therapies and potentially represent therapeutic targets.

Genetic Mechanisms of Immune Evasion in Colorectal Cancer

To understand the genetic drivers of immune recognition and evasion in colorectal cancer, we analyzed 1,211 colorectal cancer primary tumor samples, including 179 classified as microsatellite instability-high (MSI-high). This set includes The Cancer Genome Atlas colorectal cancer cohort of 592 samples, completed and analyzed here. MSI-high, a hypermutated, immunogenic subtype of colorectal cancer, had a high rate of significantly mutated genes in important immune-modulating pathways and in the antigen presentation machinery, including biallelic losses of B2M and HLA genes due to copy-number alterations and copy-neutral loss of heterozygosity. WNT/β-catenin signaling genes were significantly mutated in all colorectal cancer subtypes, and activated WNT/β-catenin signaling was correlated with the absence of T-cell infiltration. This large-scale genomic analysis of colorectal cancer demonstrates that MSI-high cases frequently undergo an immunoediting process that provides them with genetic events allowing immune escape despite high mutational load and frequent lymphocytic infiltration and, furthermore, that colorectal cancer tumors have genetic and methylation events associated with activated WNT signaling and T-cell exclusion.Significance: This multi-omic analysis of 1,211 colorectal cancer primary tumors reveals that it should be possible to better monitor resistance in the 15% of cases that respond to immune blockade therapy and also to use WNT signaling inhibitors to reverse immune exclusion in the 85% of cases that currently do not. Cancer Discov; 8(6); 730-49. ©2018 AACR.This article is highlighted in the In This Issue feature, p. 663.

Impact of oncogenic pathways on evasion of antitumour immune responses

Immunotherapeutic interventions are showing effectiveness across a wide range of cancer types, but only a subset of patients shows clinical response to therapy. Responsiveness to checkpoint blockade immunotherapy is favoured by the presence of a local, CD8+ T cell-based immune response within the tumour microenvironment. As molecular analyses of tumours containing or lacking a productive CD8+ T cell infiltrate are being pursued, increasing evidence is indicating that activation of oncogenic pathways in tumour cells can impair induction or execution of a local antitumour immune response. This Review summarizes our current knowledge of the influence of oncogenic effects on evasion of antitumour immunity.

Engineering chimeric antigen receptor-T cells for cancer treatment

Intratumor heterogeneity of tumor clones and an immunosuppressive microenvironment in cancer ecosystems contribute to inherent difficulties for tumor treatment. Recently, chimeric antigen receptor (CAR) T-cell therapy has been successfully applied in the treatment of B-cell malignancies, underscoring its great potential in antitumor therapy. However, functional challenges of CAR-T cell therapy, especially in solid tumors, remain. Here, we describe cancer-immunity phenotypes from a clonal-stromal-immune perspective and elucidate mechanisms of T-cell exhaustion that contribute to tumor immune evasion. Then we assess the functional challenges of CAR-T cell therapy, including cell trafficking and infiltration, targeted-recognition and killing of tumor cells, T-cell proliferation and persistence, immunosuppressive microenvironment and self-control regulation. Finally, we delineate tumor precision informatics and advancements in engineered CAR-T cells to counteract inherent challenges of the CAR-T cell therapy, either alone or in combination with traditional therapeutics, and highlight the therapeutic potential of this approach in future tumor precision treatment.

Recent advances and opportunities in proteomic analyses of tumour heterogeneity

Solid tumour malignancies comprise a highly variable admixture of tumour and non-tumour cellular populations, forming a complex cellular ecosystem and tumour microenvironment. This tumour heterogeneity is not incidental, and is known to correlate with poor patient prognosis for many cancer types. Indeed, non-malignant cell populations, such as vascular endothelial and immune cells, are known to play key roles supporting and, in some cases, driving aggressive tumour biology, and represent targets of emerging therapeutics, such as antiangiogenesis and immune checkpoint inhibitors. The biochemical interplay between these cellular populations and how they contribute to molecular tumour heterogeneity remains enigmatic, particularly from the perspective of the tumour proteome. This review focuses on recent advances in proteomic methods, namely imaging mass spectrometry, single-cell proteomic techniques, and preanalytical sample processing, that are uniquely positioned to enable detailed analysis of discrete cellular populations within tumours to improve our understanding of tumour proteomic heterogeneity. This review further emphasizes the opportunity afforded by the application of these techniques to the analysis of tumour heterogeneity in formalin-fixed paraffin-embedded archival tumour tissues, as these represent an invaluable resource for retrospective analyses that is now routinely accessible, owing to recent technological and methodological advances in tumour tissue proteomics. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Tumor associated macrophages in gynecologic cancers

The complex tumor microenvironment in gynecologic cancers plays a major role in modulating anti-tumor immune responses. The interaction of cancer cells with the diverse spectrum of immune effector cells has an important impact on the efficacy of standard chemotherapy and novel immunotherapy approaches. In this review, we specifically focus on the role of macrophages in ovarian, endometrial and cervical cancers. We discuss the origins of macrophages and their polarization state dictated by the microenvironment's cues. Within the tumor niche, tumor-associated macrophages (TAMs) promote tumor growth and mediate immune-suppression thereby effecting treatment responses. We outline clinical strategies that directly target TAMs, including inhibition of macrophage differentiation, prevention of the recruitment of monocytes to the tumor, enhancement of phagocytosis and immune checkpoint blockade.

Immuno-oncology-101: overview of major concepts and translational perspectives

Cancer immunotherapy is demonstrating impressive clinical benefit in different malignancies and clinical oncologists are increasingly turning their attention to immune-oncology. It is now well recognized that innate and adaptive immune cells infiltrating tumors are associated with clinical outcomes and responses to treatments, and can be harnessed to patients' benefit. Considerable advances have also been made in understanding how cancers escape from immune attack. Targeting of immunological escape processes regulated by the expression of immune checkpoint receptors and ligands and the down-modulation of tumor antigen presentation is the basis of immuno-oncology treatments. Despite recent achievements, there remain a number of unresolved issues in order to successfully implement cancer immunotherapy in many cancers. Importantly, clinical biomarkers are still needed for better optimization of emerging combination immunotherapies and better treatment tailoring. In this review, we summarize the function of innate and adaptive immune cells in anti-tumor immunity and the general mechanisms exploited by tumor cells to escape and inhibit immune responses as well as therapeutic strategies developed to overcome these mechanisms and discuss emerging biomarkers in immuno-oncology.

Ovarian Cancers: Genetic Abnormalities, Tumor Heterogeneity and Progression, Clonal Evolution and Cancer Stem Cells

Four main histological subtypes of ovarian cancer exist: serous (the most frequent), endometrioid, mucinous and clear cell; in each subtype, low and high grade. The large majority of ovarian cancers are diagnosed as high-grade serous ovarian cancers (HGS-OvCas). TP53 is the most frequently mutated gene in HGS-OvCas; about 50% of these tumors displayed defective homologous recombination due to germline and somatic BRCA mutations, epigenetic inactivation of BRCA and abnormalities of DNA repair genes; somatic copy number alterations are frequent in these tumors and some of them are associated with prognosis; defective NOTCH, RAS/MEK, PI3K and FOXM1 pathway signaling is frequent. Other histological subtypes were characterized by a different mutational spectrum: LGS-OvCas have increased frequency of BRAF and RAS mutations; mucinous cancers have mutation in ARID1A, PIK3CA, PTEN, CTNNB1 and RAS. Intensive research was focused to characterize ovarian cancer stem cells, based on positivity for some markers, including CD133, CD44, CD117, CD24, EpCAM, LY6A, ALDH1. Ovarian cancer cells have an intrinsic plasticity, thus explaining that in a single tumor more than one cell subpopulation, may exhibit tumor-initiating capacity. The improvements in our understanding of the molecular and cellular basis of ovarian cancers should lead to more efficacious treatments.

Tissue-Dependent Tumor Microenvironments and Their Impact on Immunotherapy Responses

Recent advances in cancer immunology have led to a better understanding of the role of the tumor microenvironment (TME) in tumor initiation, progression, and metastasis. Tumors can occur at many locations within the body and coevolution between malignant tumor cells and non-malignant cells sculpts the TME at these sites. It has become increasingly clear that there are specific differences of the TMEs at different anatomical locations, and these tissue-specific TMEs regulate tumor growth, determine metastatic progression, and impact on the outcome of therapy responses. Herein, we review the scientific advances in understanding tissue-specific TMEs, discuss their impact on immunotherapeutic response, and assess the current clinical knowledge in this emerging field. A deeper understanding of the tissue-specific TME will help to develop effective immunotherapies against tumors and their metastases and assist in predicting clinical outcomes.

Tumor Immunity and Survival as a Function of Alternative Neopeptides in Human Cancer

The immune system exerts antitumor activity via T cell-dependent recognition of tumor-specific antigens. Although the number of tumor neopeptides-peptides derived from somatic mutations-often correlates with immune activity and survival, most classically defined high-affinity neopeptides (CDNs) are not immunogenic, and only rare CDNs have been linked to tumor rejection. Thus, the rules of tumor antigen recognition remain incompletely understood. Here, we analyzed neopeptides, immune activity, and clinical outcome from 6,324 patients across 27 tumor types. We characterized a class of "alternatively defined neopeptides" (ADNs), which are mutant peptides predicted to bind MHC (class I or II) with improved affinity relative to their nonmutated counterpart. ADNs are abundant and molecularly distinct from CDNs. The load of ADNs correlated with intratumoral T-cell responses and immune suppression, and ADNs were also strong predictors of patient survival across tumor types. These results expand the spectrum of mutation-derived tumor antigens with potential clinical relevance. Cancer Immunol Res; 6(3); 276-87. ©2018 AACR.

Elucidating the genomic architecture of Asian EGFR-mutant lung adenocarcinoma through multi-region exome sequencing

EGFR-mutant lung adenocarcinomas (LUAD) display diverse clinical trajectories and are characterized by rapid but short-lived responses to EGFR tyrosine kinase inhibitors (TKIs). Through sequencing of 79 spatially distinct regions from 16 early stage tumors, we show that despite low mutation burdens, EGFR-mutant Asian LUADs unexpectedly exhibit a complex genomic landscape with frequent and early whole-genome doubling, aneuploidy, and high clonal diversity. Multiple truncal alterations, including TP53 mutations and loss of CDKN2A and RB1, converge on cell cycle dysregulation, with late sector-specific high-amplitude amplifications and deletions that potentially beget drug resistant clones. We highlight the association between genomic architecture and clinical phenotypes, such as co-occurring truncal drivers and primary TKI resistance. Through comparative analysis with published smoking-related LUAD, we postulate that the high intra-tumor heterogeneity observed in Asian EGFR-mutant LUAD may be contributed by an early dominant driver, genomic instability, and low background mutation rates.

EGFR mutant lung adenocarcinoma (LUAD) exhibit diverse clinical outcomes in response to targeted therapies. Here the authors show that these LUADs involve a complex genomic landscape with high intratumor heterogeneity, providing insights into the evolutionary trajectory of oncogene-driven LUAD and potential mediators of EGFR TKI resistance.

Immuno-oncology from the perspective of somatic evolution

The past years have witnessed significant success for cancer immunotherapies that activate a patient's immune system against their cancer cells. At the same time our understanding of the genetic changes driving tumor evolution have progressed dramatically. The study of cancer genomes has shown that tumors are best understood as cell populations governed by the rules of evolution, leading to the emergence and spread of cell lineages with pathogenic mutations. Moreover, somatic evolution can explain the acquisition of mutations conferring drug resistance in the ever-lasting battle for reaching even fitter cell states. Here, we review the current state of the art of somatic cancer evolution and mechanisms of immune control and escape. We also revisit the principles of immunotherapy from the perspective of somatic evolution and discuss the basic rules of resistance to immunotherapies as dictated by evolution.

Trial watch: Immunogenic cell death induction by anticancer chemotherapeutics

The expression "immunogenic cell death" (ICD) refers to a functionally unique form of cell death that facilitates (instead of suppressing) a T cell-dependent immune response specific for dead cell-derived antigens. ICD critically relies on the activation of adaptive responses in dying cells, culminating with the exposure or secretion of immunostimulatory molecules commonly referred to as "damage-associated molecular patterns". Only a few agents can elicit bona fide ICD, including some clinically established chemotherapeutics such as doxorubicin, epirubicin, idarubicin, mitoxantrone, bleomycin, bortezomib, cyclophosphamide and oxaliplatin. In this Trial Watch, we discuss recent progress on the development of ICD-inducing chemotherapeutic regimens, focusing on studies that evaluate clinical efficacy in conjunction with immunological biomarkers.

Cancer Evolution Constrained by the Immune Microenvironment

Tumor development is a Darwinian evolutionary process, involving the interplay between cancer subclones and the local immune microenvironment. These complex interactions are highlighted in this issue of Cell by the results from Jiménez-Sánchez et al. of a deep analysis of one patient with advanced serous carcinoma of the ovary.