Minireview: functional roles of tissue kallikrein, kinins, and kallikrein-related peptidases in lung cancer

Despite campaigns and improvements in detection and treatment, lung cancer continues to increase worldwide and represents a major public health problem. One approach to treating patients suffering from lung cancer is to target surface receptors overexpressed on tumor cells, such as GPCR-family kinin receptors, and proteases that control tumor progression, such as kallikrein-related peptidases (KLKs). These proteases have been visualized in recent years due to their contribution to the progression of cancers, such as prostate and ovarian cancer, facilitating the invasive and metastatic capacity of tumor cells in these tissues. In fact, KLK3 is the specific prostate antigen, the only tissue-specific biomarker used to diagnose this malignancy. In lung cancer to date, evidence indicates that KLK5, KLK6, KLK8, KLK11, and KLK14 are the major peptidases regulated and involved in its progression. The expression levels of KLKs in this neoplasm are modulated by the secretome of the different cell types present in the tumor microenvironment, the cancer subtype and the tumor stage, among others. Considering the multiple functions of kinin receptors and KLKs, this review highlights their roles, even considering the SARS-CoV-2 effects. Since lung cancer is often diagnosed in advanced stages, our efforts should focus on early diagnosis, validating for example specific KLKs, especially in high-risk populations such as smokers and people exposed to carcinogenic fumes, oil fields, and contaminated workplaces, unexplored fields to investigate. Furthermore, their modulation could be considered as a promising approach in lung cancer therapeutics.

Intersections between innate immune response and gastric cancer development

Worldwide, gastric cancer (GC) is the fifth most commonly diagnosed malignancy. It has a reduced prevalence but has maintained its poor prognosis being the fourth leading cause of deaths related to cancer. The highest mortality rates occur in Asian and Latin American countries, where cases are usually diagnosed at advanced stages. Overall, GC is viewed as the consequence of a multifactorial process, involving the virulence of the Helicobacter pylori (H. pylori) strains, as well as some environmental factors, dietary habits, and host intrinsic factors. The tumor microenvironment in GC appears to be chronically inflamed which promotes tumor progression and reduces the therapeutic opportunities. It has been suggested that inflammation assessment needs to be measured qualitatively and quantitatively, considering cell-infiltration types, availability of receptors to detect damage and pathogens, and presence or absence of aggressive H. pylori strains. Gastrointestinal epithelial cells express several Toll-like receptors and determine the first defensive line against pathogens, and have been also described as mediators of tumorigenesis. However, other molecules, such as cytokines related to inflammation and innate immunity, including immune checkpoint molecules, interferon-gamma pathway and NETosis have been associated with an increased risk of GC. Therefore, this review will explore innate immune activation in the context of premalignant lesions of the gastric epithelium and established gastric tumors.

The Armed Conflict and the Impact on Patients With Cancer in Ukraine: Urgent Considerations

On February 24, 2022, a war began within the Ukrainian borders. At least 3.0 million Ukrainian inhabitants have already fled the country. Critical infrastructure, including hospitals, has been damaged. Children with cancer were urgently transported to foreign countries, in an effort to minimize interruption of their life-saving treatments. Most adults did not have that option. War breeds cancer—delaying diagnosis, preventing treatment, and increasing risk. We project that a modest delay in care of only 4 months for five prevalent types of cancer will lead to an excess of over 3,600 cancer deaths in the subsequent years. It is critical that we establish plans to mitigate that risk as soon as possible.

Ukraine conflict may cost 3600 lives or more because of a delay and lack of access for patients with cancer.

Tumor cell SYK expression modulates the tumor immune microenvironment composition in human cancer via TNF-α dependent signaling

BACKGROUND

The expression of SYK in cancer cells has been associated with both tumor promoting and tumor suppressive effects. Despite being proposed as anticancer therapeutic target, the possible role of SYK in modulating local adaptive antitumor immune responses remains uncertain. Using detailed analysis of primary human tumors and in vitro models, we reveal the immunomodulatory effect of SYK protein in human solid cancer.

METHODS

We spatially mapped SYK kinase in tumor cells, stromal cells and tumor-infiltrating leukocytes (TILs) in 808 primary non-small cell lung carcinomas (NSCLCs) from two cohorts and in 374 breast carcinomas (BCs) from two independent cohorts. We established the associations of localized SYK with clinicopathologic variables and outcomes. The immunomodulatory role of SYK on tumor cells was assessed using in vitro cytokine stimulation, transcriptomic analysis and selective SYK blockade using a small molecule inhibitor. Functional responses were assessed using cocultures of tumor cells with peripheral blood lymphocytes. T cell responses in baseline and post-treatment biopsies from patients with BC treated with a SYK inhibitor in a phase I clinical trial were also studied.

RESULTS

Elevated tumor cell or leukocyte SYK expression was associated with high CD4⁺ and CD8⁺ TILs and better outcome in both NSCLC and BC. Tumor cell SYK was associated with oncogenic driver mutations in EGFR or KRAS in lung adenocarcinomas and with triple negative phenotype in BC. In cultured tumor cells, SYK was upregulated by TNFα and required for the TNFα-induced proinflammatory responses and T cell activation. SYK blockade after nivolumab in a phase I clinical trial including three patients with advanced triple negative BC reduced TILs and T cell proliferation. Our work establishes the proinflammatory function of tumor cell SYK in lung and breast cancer. SYK signaling in cultured tumor cells is required for T cell activation and SYK blockade limits adaptive antitumor immune responses and tumor rejection in patients with cancer.

CONCLUSIONS

Together, our results establish the immunomodulatory role of SYK expression in human solid tumors. This information could be used to develop novel biomarkers and/or therapeutic strategies.

Quantitative tissue analysis and role of myeloid cells in non-small cell lung cancer

BACKGROUND

Despite the prominent role of innate immunity in the antitumor response, little is known about the myeloid composition of human non-small cell lung cancer (NSCLC) with respect to histology and molecular subtype. We used multiplexed quantitative immunofluorescence (QIF) to measure the distribution and clinical significance of major myeloid cell subsets in large retrospective NSCLC collections.

METHODS

We established a QIF panel to map major myeloid cell subsets in fixed human NSCLC including 4',6-Diamidino-2-Phenylindole for all cells, pancytokeratin for tumor-epithelial cells, CD68 for M1-like macrophages; and CD11b plus HLA-DR to interrogate mature and immature myeloid cell populations such as myeloid derived suppressor cells (MDSCs). We interrogated 793 NSCLCs represented in four tissue microarray-based cohorts: #1 (Yale, n=379) and #2 (Greece, n=230) with diverse NSCLC subtypes; #3 (Yale, n=138) with molecularly annotated lung adenocarcinomas (ADC); and #4 (Yale, n=46) with patient-matched NSCLC and morphologically-normal lung tissue. We examined associations between marker levels, myeloid cell profiles, clinicopathologic/molecular variables and survival.

RESULTS

The levels of CD68+ M1 like macrophages were significantly lower and the fraction of CD11b+/HLA-DR- MDSC-like cells was prominently higher in tumor than in matched non-tumor lung tissues. HLA-DR was consistently higher in myeloid cells from tumors with elevated CD68 expression. Stromal CD11b was significantly higher in squamous cell carcinomas (SCC) than in ADC across the cohorts and EGFR-mutated lung ADCs displayed lower CD11b levels than KRAS-mutant tumors. Increased stromal CD68- and HLA-DR-expressing cells was associated with better survival in ADCs from two independent NSCLC cohorts. In SCC, increased stromal CD11b or HLA-DR expression was associated with a trend towards shorter 5-year survival.

CONCLUSIONS

NSCLCs display an unfavorable myeloid immune contexture relative to non-tumor lung and exhibit distinct myeloid-cell profiles across histologies and presence of major oncogenic driver-mutations. Elevated M1-like stromal proinflammatory myeloid cells are prognostic in lung ADC, but not in SCC.

Effects of Radiation on the Tumor Microenvironment

A malignant tumor consists of malignant cells as well as a wide array of normal host tissues including stroma, vasculature, and immune infiltrate. The interaction between cancer and these host tissues is critical as these host tissues play a variety of roles in supporting or resisting disease progression. Radiotherapy (RT) has direct effects on malignant cells, but, also, critically important effects on these other components of the tumor microenvironment (TME). Given the growing role of immune checkpoint inhibitors and other immunotherapy strategies, understanding how RT affects the TME, particularly the immune compartment, is essential to advance RT in this new era of cancer therapy. The interactions between RT and the TME are complex, affecting the innate and adaptive arms of the immune system. RT can induce both proinflammatory effects and immune suppressive effects that can either promote or impede antitumor immunity. It is likely that the initial proinflammatory effects of RT eventually lead to rebound immune-suppression as chronic inflammation sets in. The exact kinetics and nature of how RT changes the TME likely depends on timing, dose, fractionation, site irradiated, and tumor type. With increased understanding of the effects of RT on the TME, in the future it is likely that we will be able to personalize RT by varying the dose, site, and timing of intervention to generate the desired response to partner with immunotherapy strategies.

Early versus deferred anti-SARS-CoV-2 convalescent plasma in patients admitted for COVID-19: A randomized phase II clinical trial

BACKGROUND

Convalescent plasma (CP), despite limited evidence on its efficacy, is being widely used as a compassionate therapy for hospitalized patients with COVID-19. We aimed to evaluate the efficacy and safety of early CP therapy in COVID-19 progression.

METHODS AND FINDINGS

The study was an open-label, single-center randomized clinical trial performed in an academic medical center in Santiago, Chile, from May 10, 2020, to July 18, 2020, with final follow-up until August 17, 2020. The trial included patients hospitalized within the first 7 days of COVID-19 symptom onset, presenting risk factors for illness progression and not on mechanical ventilation. The intervention consisted of immediate CP (early plasma group) versus no CP unless developing prespecified criteria of deterioration (deferred plasma group). Additional standard treatment was allowed in both arms. The primary outcome was a composite of mechanical ventilation, hospitalization for >14 days, or death. The key secondary outcomes included time to respiratory failure, days of mechanical ventilation, hospital length of stay, mortality at 30 days, and SARS-CoV-2 real-time PCR clearance rate. Of 58 randomized patients (mean age, 65.8 years; 50% male), 57 (98.3%) completed the trial. A total of 13 (43.3%) participants from the deferred group received plasma based on clinical aggravation. We failed to find benefit in the primary outcome (32.1% versus 33.3%, odds ratio [OR] 0.95, 95% CI 0.32-2.84, p > 0.999) in the early versus deferred CP group. The in-hospital mortality rate was 17.9% versus 6.7% (OR 3.04, 95% CI 0.54-17.17 p = 0.246), mechanical ventilation 17.9% versus 6.7% (OR 3.04, 95% CI 0.54-17.17, p = 0.246), and prolonged hospitalization 21.4% versus 30.0% (OR 0.64, 95% CI, 0.19-2.10, p = 0.554) in the early versus deferred CP group, respectively. The viral clearance rate on day 3 (26% versus 8%, p = 0.204) and day 7 (38% versus 19%, p = 0.374) did not differ between groups. Two patients experienced serious adverse events within 6 hours after plasma transfusion. The main limitation of this study is the lack of statistical power to detect a smaller but clinically relevant therapeutic effect of CP, as well as not having confirmed neutralizing antibodies in donor before plasma infusion.

CONCLUSIONS

In the present study, we failed to find evidence of benefit in mortality, length of hospitalization, or mechanical ventilation requirement by immediate addition of CP therapy in the early stages of COVID-19 compared to its use only in case of patient deterioration.

TRIAL REGISTRATION

NCT04375098.

Graph of graphs analysis for multiplexed data with application to imaging mass cytometry

Imaging Mass Cytometry (IMC) combines laser ablation and mass spectrometry to quantitate metal-conjugated primary antibodies incubated in intact tumor tissue slides. This strategy allows spatially-resolved multiplexing of dozens of simultaneous protein targets with 1μm resolution. Each slide is a spatial assay consisting of high-dimensional multivariate observations (m-dimensional feature space) collected at different spatial positions and capturing data from a single biological sample or even representative spots from multiple samples when using tissue microarrays. Often, each of these spatial assays could be characterized by several regions of interest (ROIs). To extract meaningful information from the multi-dimensional observations recorded at different ROIs across different assays, we propose to analyze such datasets using a two-step graph-based approach. We first construct for each ROI a graph representing the interactions between the m covariates and compute an m dimensional vector characterizing the steady state distribution among features. We then use all these m-dimensional vectors to construct a graph between the ROIs from all assays. This second graph is subjected to a nonlinear dimension reduction analysis, retrieving the intrinsic geometric representation of the ROIs. Such a representation provides the foundation for efficient and accurate organization of the different ROIs that correlates with their phenotypes. Theoretically, we show that when the ROIs have a particular bi-modal distribution, the new representation gives rise to a better distinction between the two modalities compared to the maximum a posteriori (MAP) estimator. We applied our method to predict the sensitivity to PD-1 axis blockers treatment of lung cancer subjects based on IMC data, achieving 97.3% average accuracy on two IMC datasets. This serves as empirical evidence that the graph of graphs approach enables us to integrate multiple ROIs and the intra-relationships between the features at each ROI, giving rise to an informative representation that is strongly associated with the phenotypic state of the entire image.

Seroconversion and Abundance of IgG Antibodies against S1-RBD of SARS-CoV-2 and Neutralizing Activity in the Chilean Population

COVID-19 is a pandemic caused by SARS-CoV-2. In Chile, half a million people have been infected and more than 16,000 have died from COVID-19. As part of the clinical trial NCT04384588, we quantified IgG against S1-RBD of SARS-CoV-2 (anti-RBD) in recovered people in Santiago and evaluated their suitability as COVID-19 convalescent plasma donors. ELISA and a luminescent SARS-CoV-2 pseudotype were used for IgG and neutralizing antibody quantification. 72.9% of the convalescent population (468 of 639) showed seroconversion (5-55 μg/mL anti-RBD IgG) and were suitable candidates for plasma donation. Analysis by gender, age, and days after symptom offset did not show significant differences. Neutralizing activity correlated with an increased concentration of anti-RBD IgG (p < 0.0001) and showed a high variability between donors. We confirmed that the majority of the Chilean patients have developed anti-SARS-CoV-2 antibodies. The quantification of anti-RBD IgG in convalescent plasma donors is necessary to increase the detection of neutralizing antibodies.

Biomarker Discovery in Patients with Immunotherapy-Treated Melanoma with Imaging Mass Cytometry

PURPOSE

Imaging mass cytometry (IMC) is among the first tools with the capacity for multiplex analysis of more than 40 targets, which provides a novel approach to biomarker discovery. Here, we used IMC to characterize the tumor microenvironment of patients with metastatic melanoma who received immunotherapy in efforts to find indicative factors of treatment response. In spite of the new power of IMC, the image analysis aspects are still limited by the challenges of cell segmentation.

EXPERIMENTAL DESIGN

Here, rather than segment, we performed image analysis using a newly designed version of the AQUA software to measure marker intensity in molecularly defined compartments: tumor cells, stroma, T cells, B cells, and macrophages. IMC data were compared with quantitative immunofluorescence (QIF) and digital spatial profiling.

RESULTS

Validation of IMC results for immune markers was confirmed by regression with additional multiplexing methods and outcome assessment. Multivariable analyses by each compartment revealed significant associations of 12 markers for progression-free survival and seven markers for overall survival (OS). The most compelling indicative biomarker, beta2-microglobulin (B2M), was confirmed by correlation with OS by QIF in the discovery cohort and validated in an independent published cohort profiled by mRNA expression.

CONCLUSIONS

Using digital image analysis based on pixel colocalization to assess IMC data allowed us to quantitively measure 25 markers simultaneously on formalin-fixed, paraffin-embedded tissue microarray samples. In addition to showing high concordance with other multiplexing technologies, we identified a series of potentially indicative biomarkers for immunotherapy in metastatic melanoma, including B2M.

Abstract 2523: Loss of expression of wild-type transcript of CDH1 gene is associated with overexpression of microRNA-20 in diffuse-type of gastric cancer

Background: Gastric cancer (GC) is the third cause of cancer death in the world. In Latin America, GC is one of the leading causes of death, particularly in Chile. E-cadherin has been classified as a tumor suppressor gene that participates in cell adhesion. Reduction or loss of E-cadherin expression could promote tumor progression particularly in the sporadic diffuse subtype of GC (SDGC). In addition, inactivation germline mutations of CDH1 (E-cadherin gene) have been linked to the hereditary diffuse gastric cancer (HDGC) syndrome.

Methods: We evaluated the expression of E-cadherin by Immunohistochemistry (IHC) in SDGC (n=27) and HDGC (n=22) cohorts. We also analyzed, by Sanger sequencing the full coding region of CDH1 in both cohorts. To identified miRNA-CDH1 interactions, an in silico analysis by mirWalk 2.0 software (5 or more algorithms) was performed. To validated in silico findings, 10 paired tumor and normal matched fresh gastric tissues were analyzed by miQ-PCR (miRNA) and qRT-PCR assay (CDH1 transcript) were performed.

Results: The expression analysis of E-cadherin showed loss of expression in 13/27 (48%) SDGC and in 19/22 (90%) HDGC cases, respectively. The decrease of E-cadherin expression was significantly higher in the hereditary cohort (p=0.002, χ2: 9.12, 95%CI:13.0-63.3). Exome sequence analysis of the full coding region of CDH1 identified 3 and 9 mutations in SDGC and HDGC, respectively. Correlation between loss of protein expression by IHC and mutations was not found. Next, we explore the role of miRNA, as an alternative mechanism of the loss of E-cadherin protein expression. In silico analysis identified 417 miRNAs candidates with predicted binding sites. Among these candidates, all members of the polycistronic cluster miR-17/92 have seed regions against the 3'-UTR of the CDH1 transcript. Levels of expression of all 6 members of the polycistronic cluster were validated against CDH1 expression in paired normal and tumor fresh tissues of SDGC. A strong inverse correlation between the overexpression of miR-20a and downregulation of CDH1 transcript was found exclusively in tumor tissue (p= 0.0267) but not in normal counterparts. These results were validated in the STAD-TCGA cohort.

Conclusions: Our results might explain the loss of expression of CDH1 in GC due to overexpression miR-20, a member of the polycistronic cluster miR-17/92. Future experimental validation of the predicted seed region will be necessary to confirm these findings.

Grant support: CONICYT-FONDAP-15130011, Fondecyt-1191928

Citation Format: Natalia Landeros, Maria A. Alarcon, Graciela Molina, Pablo Santoro, Keila Torres, Wilda Olivares, Ignacio Wichmann, Franz Villarroel-Espindola, Iva Polakovicova, Enrique Norero, Alejandro H. Corvalan. Loss of expression of wild-type transcript of CDH1 gene is associated with overexpression of microRNA-20 in diffuse-type of gastric cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2523.

Abstract 2001: Biomarker discovery in immunotherapy-treated melanoma patients with imaging mass cytometry

Background: Understanding the complexity of the tumor microenvironment could allow identification of new biomarkers that predict response to immunotherapy in cancer patients and anticipate the toxicity associated with the treatment. Since the number of targets measurable by quantitative immunofluorescence (QIF) is limited, we applied Imaging Mass Cytometry (IMC), a metal-conjugated antibody-based high-plex technology, to generate a multidimensional analysis of the microenvironment. We interrogated a 25-antibody panel, including tumor and immune cell markers, in a cohort of melanoma patients treated with immune checkpoint blockers.

Methods: We used a validated, optimized panel of 25 antibodies conjugated to unique metals, including a DNA intercalator conjugated with 191/193Ir, for detection using HyperionTM (Fluidigm). Digital image analysis was performed using a newly designed version of the AQUA software (Navigate BP) to measure marker intensity in molecularly defined masks or compartments as follows: all cells (DNA intercalator Ir191/193), tumor cells (HMB45/S100), stroma (tumor cells subtracted from all cells), T cells (CD3), B cells (CD20) and macrophages (CD68). Results were compared to QIF and Digital Spatial Profiling (DSP), a NanoString technology based on primary antibodies conjugated to indexing DNA oligos. We examined archived formalin-fixed paraffin-embedded (FFPE) samples from a metastatic melanoma cohort treated with immunotherapy (n=60) in tissue microarray format.

Results: Immune markers such as CD3, CD4 and CD8 showed a high correlation between the three multiplexing methods: IMC, DSP and QIF (r=0.48-0.89, p&lt;0.0001). Moreover, high CD3 and CD8 levels assessed by IMC were statistically significantly associated with favorable outcome, confirming results previously published on the same cohort (Toki et al, CCR, 2018). Multivariable analyses revealed significant associations of MHC-I, CSF1R, IRF1, LAG3, PD1, MHC-II and beta2-microglobulin (B2M) in tumor with progression-free survival (PFS) independent of age, sex, mutation, stage, treatment, and prior immune checkpoint blockade treatment. In stroma, high TIM3 and high PD-L2 also predicted response to immunotherapy. Furthermore, we tested for validation by QIF B2M, MHC-I and CSF1R, predictive markers identified by IMC. However, only B2M showed a statistically significant correlation with overall survival.

Conclusion: Using IMC technology and digital image analysis based on pixel colocalization, we were able to evaluate simultaneously 25 markers on FFPE tissue microarray samples. There was a high concordance with QIF and DSP for immune markers such as CD3, CD4 and CD8. A series of potentially predictive biomarkers for immunotherapy in metastatic melanoma were identified.

Citation Format: Sandra Martinez-Morilla, Franz Villarroel-Espindola, Pok Fai Wong, Harriet Kluger, Maria Toki, Thazin New Aung, Vasiliki Pelekanou, Brian Bourke-Martin, David L. Rimm. Biomarker discovery in immunotherapy-treated melanoma patients with imaging mass cytometry [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2001.

Abstract 5525: VISTA/PSGL1 axis as a dominant immunomodulatory pathway in human non-small cell lung cancer

Introduction.

VISTA/PD-1H is an Ig domain-containing type I transmembrane protein able to suppress T-cell activation and is being evaluated as a candidate anti-cancer immunotherapy target. VISTA can bind P-selectin glycoprotein ligand-1 (PSGL1) and V-set and immunoglobulin domain containing 3 (VSIG3) suggesting these interactions could mediate VISTA's immunomodulatory effect. We studied the tissue distribution of VISTA, PSGL1 and VSIG3 in human non-small cell lung cancer (NSCLC).

Methods

We used multiplexed quantitative immunofluorescence (QIF) to simultaneously measure DAPI, cytokeratin (CK), VISTA, PSGL1 and VSIG3 in 48 paired tumor/normal lung samples and in 850 stage I-IV NSCLCs from four independent cohorts represented in tissue microarray format. The first 2 NSCLC cohorts (Cohorts #1, n=382 and #2, n=282) included cases treated with standard of care non-immunotherapy. Cohort #3 included 137 lung adenocarcinomas with analysis of mutant oncogenic drivers; and Cohort #4 included 49 NSCLC cases treated with PD-1 axis blockers. The targets were selectively measured in CK+ tumor cells and CK-negative stromal cells. We also determined the spatial association between VISTA and its binding partners by fluorescence signal co-localization. The association between target levels, clinicopathologic/molecular variables, tumor infiltrating lymphocytes (TILs), PD-L1 expression and survival was established.

Results

PSGL1 was located predominantly in stromal/immune cells and VSIG3 was detected in both tumor and stromal compartments. Both targets were expressed at higher levels in NSCLC than in non-tumor lung tissue and showed a positive association with VISTA in cancer tissues. Using the visual detection threshold PSGL1 and VSIG3 expression were detected in &gt;90% of cases from cohorts #1 and #2 and showed positive association with CD3+ TILs and PD-L1 levels. PSGL1 was higher in lung adenocarcinomas harboring EGFR mutations than in tumors with KRAS variants or cases lacking mutations in both oncogenes. Elevated VISTA/PSGL1 co-localization was significantly associated with longer 5-year overall survival in cases not treated with immunostimulatory therapy (Cohorts #1 and #2). However, an opposite association was seen in cases treated with PD-1 axis blockers, where elevated VISTA/PSGL1 co-expression was associated with shorter survival.

Conclusions

PSGL1 and VSIG3 are frequently expressed in human NSCLC. Expression of PSGL1 is associated with increased tumor immune infiltration and activating EGFR mutations. High baseline VISTA/PSGL1 co-expression is associated with adverse outcome after PD-1 axis blockers. The latter suggest VISTA/PSGL1 as a dominant immune evasion pathway independent from PD-1/PD-L1 axis in a subset of human NSCLC. Validation of these findings is ongoing.

Citation Format: Alicia Ding, Franz Villarroel-Espindola, Adam Ducler, Brian S. Henick, Shruti Desai, Nicole Gianino, Jon Zugazagoitia, David L. Rimm, Alain Robert, Francisco Cruzalegui, Pierre Ferré, Roy Herbst, Miguel Sanmamed, Lieping Chen, Kurt A. Schalper. VISTA/PSGL1 axis as a dominant immunomodulatory pathway in human non-small cell lung cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5525.

Multiplexed (18-Plex) Measurement of Signaling Targets and Cytotoxic T Cells in Trastuzumab-Treated Patients using Imaging Mass Cytometry

PURPOSE

Imaging mass cytometry (IMC) uses metal-conjugated antibodies to provide multidimensional, objective measurement of protein targets. We used this high-throughput platform to perform an 18-plex assessment of HER2 ICD/ECD, cytotoxic T-cell infiltration and other structural and signaling proteins in a cohort of patients treated with trastuzumab to discover associations with trastuzumab benefit.

EXPERIMENTAL DESIGN

An antibody panel for detection of 18 targets (pan-cytokeratin, HER2 ICD, HER2 ECD, CD8, vimentin, cytokeratin 7, β-catenin, HER3, MET, EGFR, ERK 1-2, MEK 1-2, PTEN, PI3K p110 α, Akt, mTOR, Ki67, and Histone H3) was used with a selection of trastuzumab-treated patients from the Hellenic Cooperative Oncology Group 10/05 trial (n = 180), and identified a case-control series.

RESULTS

Patients that recurred after adjuvant treatment with trastuzumab trended toward a decreased fraction of HER2 ECD pixels over threshold compared with cases without recurrence (P = 0.057). After exclusion of the lowest HER2 expressers, 5-year recurrence events were associated with reduced total extracellular domain (ECD)/intracellular domain (ICD) ratio intensity in tumor (P = 0.044). These observations are consistent with our previous work using quantitative immunofluorescence, but represent the proof on identical cell content. We also describe the association of the ECD of HER2 with CD8 T-cell infiltration on the same slide.

CONCLUSIONS

The proximity of CD8 cells as a function of the expression of the ECD of HER2 provides further evidence for the role of the immune system in the mechanism of action of trastuzumab.

CD68, CD163, and matrix metalloproteinase 9 (MMP-9) co-localization in breast tumor microenvironment predicts survival differently in ER-positive and -negative cancers

Background

The role of tumor-associated macrophages (TAMs) in the cancer immune landscape and their potential as treatment targets or modulators of response to treatment are gaining increasing interest. TAMs display high molecular and functional complexity. Therefore their objective assessment as breast cancer biomarkers is critical. The aims of this study were to objectively determine the in situ expression and significance of TAM biomarkers (CD68, CD163, and MMP-9) in breast cancer and to identify subclasses of patients who could benefit from TAM-targeting therapies.

Methods

We measured CD68, CD163, and MMP-9 protein expression in formalin-fixed paraffin-embedded tissues of breast carcinomas represented in tissue microarray format using multiplexed quantitative immunofluorescence (QIF) in two independent Yale cohorts: cohort A—n = 398, estrogen receptor–positive (ER⁺) and ER⁻ cases—and the triple-negative breast cancer (TNBC)-only cohort B (n = 160). Associations between macrophage markers, ER status, and survival were assessed. Protein expression measured by QIF was compared with mRNA expression data from the METABRIC study.

Results

All three macrophage markers were co-expressed, displaying higher expression in ER⁻ cancers. High pan-macrophage marker CD68 correlated with poorer overall survival (OS) only in ER⁻ cases of cohort A (P = 0.02). High expression of CD163 protein in TAMs was associated with improved OS in ER⁻ cases (cohort A, P = 0.03 and TNBC cohort B, P = 0.04, respectively) but not in ER⁺ cancers. MMP-9 protein was not individually associated with OS. High expression of MMP-9 in the CD68⁺/CD163⁺ TAMs was associated with worse OS in ER⁺ tumors (P <0.001) but not in ER⁻ cancers. In the METABRIC dataset, mRNA levels followed the co-expression pattern observed in QIF but did not always show the same trend regarding OS.

Conclusions

Macrophage activity markers correlate with survival differently in ER⁺ and ER⁻ cancers. The association between high co-expression and co-localization of MMP-9/CD163/CD68 and poor survival in ER⁺ cancers suggests that these cancers may be candidates for macrophage-targeted therapies.

Electronic supplementary material

The online version of this article (10.1186/s13058-018-1076-x) contains supplementary material, which is available to authorized users.

Spatially Resolved and Quantitative Analysis of VISTA/PD-1H as a Novel Immunotherapy Target in Human Non-Small Cell Lung Cancer

Purpose: Determine the localized expression pattern and clinical significance of VISTA/PD-1H in human non-small cell lung cancer (NSCLC).Experimental Design: Using multiplex quantitative immunofluorescence (QIF), we performed localized measurements of VISTA, PD-1, and PD-L1 protein in 758 stage I-IV NSCLCs from 3 independent cohorts represented in tissue microarray format. The targets were selectively measured in cytokeratin+ tumor epithelial cells, CD3+ T cells, CD4+ T-helper cells, CD8+ cytotoxic T cells, CD20+ B lymphocytes and CD68+ tumor-associated macrophages. We determined the association between the targets, clinicopathological/molecular variables and survival. Genomic analyses of lung cancer cases from TCGA were also performed.Results: VISTA protein was detected in 99% of NSCLCs with a predominant membranous/cytoplasmic staining pattern. Expression in tumor and stromal cells was seen in 21% and 98% of cases, respectively. The levels of VISTA were positively associated with PD-L1, PD-1, CD8+ T cells and CD68+ macrophages. VISTA expression was higher in T-lymphocytes than in macrophages; and in cytotoxic T cells than in T-helper cells. Elevated VISTA was associated with absence of EGFR mutations and lower mutational burden in lung adenocarcinomas. Presence of VISTA in tumor compartment predicted longer 5-year survival.Conclusions: VISTA is frequently expressed in human NSCLC and shows association with increased tumor-infiltrating lymphocytes, PD-1 axis markers, specific genomic alterations and outcome. These results support the immunomodulatory role of VISTA in human NSCLC and suggests its potential as therapeutic target. Clin Cancer Res; 24(7); 1562-73. ©2017 AACR.

Abstract P2-09-18: Multiplexed (18-Plex) measurement of protein targets in trastuzumab-treated patients using imaging mass cytometry

Introduction: Recent studies have shown that the molecular heterogeneity of HER2 intracellular (ICD) and extracellular (ECD) domains, as well as overall immune infiltration, are associated with response to adjuvant trastuzumab. Traditional strategies for in situ measurement in the tumor microenvironment allow the combination of up to 6 targets, limiting our capability for in-depth interrogation of tissues. Imaging Mass Cytometry (IMC) uses metal-conjugated antibodies to provide multidimensional, objective measurement of protein targets. We used this high-throughput multiplexing platform to perform an 18-plex assessment of HER2 ICD/ECD, cytotoxic T cell infiltration and other structural and signaling proteins in a cohort of patients treated with trastuzumab.

Methods: An antibody panel for detection of 18 targets (Pancytokeratin, HER2 ICD, HER2 ECD, CD8, vimentin, cytokeratin 7, beta-catenin, HER3, MET, EGFR, ERK 1-2, MEK 1-2, PTEN, PI3K p110 alpha, Akt, mTOR, Ki67 and Histone H3) was conjugated to unique metals for detection in an IMC instrument (Fluidigm). All assays were objectively standardized and validated using quantitative immunofluoresce (QIF). Finally, the IMC technique was validated against HER2 single marker assays by QIF. We used a collection of trastuzumab-treated patients from the HeCOG 10/05 trial (n=180), and identified a case:control series using 5-year recurrence events (n=19), which were matched to controls (n=41) by age and TNM stage. Formalin-fixed, paraffin embedded tissues in tissue microarray format were ablated in the IMC attachment to the CyTOF flow cytometer for simultaneous detection of markers. Image visualization was conducted using MCD Viewer (Fluidigm). Statistical analyses were performed using a range of platforms.

Results: Patients that recurred after adjuvant treatment with trastuzumab showed a decreased fraction of HER2 ECD pixels over threshold in a compartment determined by CK and HER2 ICD compared to cases without recurrence (p=0.057). After exclusion of the lowest HER2 expressers (that would have fallen below the threshold for positive by current HER2 assays), 5-year recurrence events where associated with reduced total ECD/ ICD ratio intensity in tumor (p=0.044). Patients below the median for total ECD/ICD ratio showed a trend for decreased benefit from trastuzumab (p=0.066). Levels of cytotoxic T cell infiltration, depicted by total CD8 intensity, were lower in patients with recurrences (p=0.05).

Conclusion: Objective measurement of highly multiplexed protein targets in routine, fixed breast cancer tissues shows that a decreased ratio of HER2 ECD/ ICD is associated with 5-year recurrence after trastuzumab treatment. This observation is consistent with our previous work using QIF but represents the first time this has been done on identical cell content (on a single tissue section). Additionally, on the same section we found that lower levels of overall cytotoxic T cell infiltration were associated with worse outcome. Further analysis of the multiplexed data, including both correlative and distance-based analyses are underway.

Citation Format: Carvajal-Hausdorf DE, Stanton KP, Patsenker J, Villarroel-Espindola F, Esch A, Montgomery RR, Psyrri A, Kalogeras KT, Kotoula V, Fountzilas G, Schalper KA, Kluger Y, Rimm DL. Multiplexed (18-Plex) measurement of protein targets in trastuzumab-treated patients using imaging mass cytometry [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-09-18.

Abstract 5657: Objective measurement and significance of VISTA (PD-1H) expression in non-small cell lung cancer (NSCLC)

Introduction: VISTA (PD-1H) is a member of the B7 family of immune co-regulatory molecules and has been proposed as a novel anti-cancer immunotherapy target. The intra- and extracellular domains of VISTA show homology to PD-1 and PD-L1, respectively, suggesting a role in anti-tumor immune evasion. The expression of VISTA, its association with PD-1 axis components and biological role in human NSCLC are unknown.

Methods: Using multiplex quantitative immunofluorescence (QIF), we simultaneously measured the levels of VISTA (clone D1L2G, CST), PD-L1 (clone 405.9A11, CST) and PD-1 (clone EH33, CST) protein in 732 stage I-IV NSCLCs from 3 retrospective collections represented in tissue microarray format (cohort #1 [n=297, Yale], cohort #2 [n=329, Greece]; and cohort #3 [n=106, Yale]). To evaluate the tumor tissue distribution, VISTA was also selectively measured in cytokeratin+ tumor cells, CD3+ T-cells, CD4+ T-helper cells, CD8+ cytotoxic T-cells and CD20+ B-lymphocytes. Associations between the marker levels, clinico-pathological-molecular variables and survival were studied.

Results: VISTA protein was detected in all NSCLCs, showed a membranous staining pattern and was localized predominantly in the tumor cells in 27.4% of cases; and in the stromal compartment in 98.5%. Although VISTA was detected in all major tumor infiltrating lymphocyte (TIL) subsets, the signal was higher in CD20+ B-cells than in CD3+ T-lymphocytes (P&lt;0.05); and in CD4+ helper than in CD8+ cytotoxic T-cells (P&lt;0.001). Using the median score as cut point, elevated VISTA in tumor and/or stromal cells was significantly associated with high PD-L1, PD-1 protein expression and increased CD8+TILs in the cohorts (P&lt;0.001 - P&lt;0.05). No consistent association between VISTA levels and age, gender, smoking status, specific NSCLC histology, stage, EGFR/KRAS mutations and overall survival was found.

Conclusion: VISTA is expressed in the majority of NSCLCs and shows differential distribution in tumor/stromal cells and TIL subsets, suggesting a complex function as a ligand and receptor. Elevated expression of VISTA in NSCLC is associated with increased PD-1 axis targets and cytotoxic T-cell density, indicating its possible modulation by pro-inflammatory signals. Our results support VISTA as a candidate target for anti-cancer immunotherapy in NSCLC alone or in combination with PD-1 axis blockers.

Citation Format: Franz Villarroel-Espindola, Ila J. Datar, Vamsidhar Velcheti, David L. Rimm, Roy S. Herbst, Kurt A. Schalper. Objective measurement and significance of VISTA (PD-1H) expression in non-small cell lung cancer (NSCLC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5657. doi:10.1158/1538-7445.AM2017-5657

Abstract 5600: Simultaneous measurement and clinical significance of PD-1, LAG-3 and TIM-3 in non-small cell lung cancer (NSCLC)

Introduction: The ineffective anti-tumor immune response is characterized by increased immune suppressive signals in the tumor microenvironment. In particular, T-cells recognizing tumor antigens can express diverse immune inhibitory receptors mediating lymphocyte inactivation and limiting tumor rejection. Blockade of these receptors such as PD-1 induces prominent clinical benefit in patients with NSCLC. However, the expression and significance of additional potentially actionable immune inhibitory receptors in lung cancer is poorly understood.

Methods: After careful validation of assays and using multiplexed quantitative immunofluorescence (QIF) we measured the levels of CD3 (rabbit polyclonal, Dako), PD-1 (clone EH33, CST), LAG-3 (Clone 17B4, Abcam) and TIM-3 (clone D5D5R, CST) in 698 stages I-IV formalin-fixed paraffin embedded (FFPE) lung carcinomas represented in three tissue microarrays (cohort #1 [Yale n=186], cohort #2 [Yale n=192, and cohort #3 [Greece n=320]). We also included a collection of lung adenocarcinomas with molecular annotation (cohort #4 [Yale n=106]). The targets were measured in all cells of the preparation using fluorescence co-localization with DAPI and specifically in CD3-positive T-lymphocytes. Associations between the markers and with major clinico-pathological variables, driver mutations and survival were studied.

Results: All the targets were detected predominantly in CD3+ T-cells with membranous staining. Expression of PD-1, LAG-3 and TIM-3 in T-cells across all NSCLC cohorts was 68.7%, 39.7% and 55.8%, respectively. Elevated levels of PD-1, LAG-3 or TIM-3 were significantly associated with increased tumor infiltrating lymphocytes and with the co-expression of one or more of the other inhibitory receptors (P&lt;0.001). Simultaneous co-expression of all 3 markers was identified in 32.6% of cases. No consistent association was seen between the targets and patient age, gender, smoking status, clinical stage, tumor histology and overall survival. PD-1, TIM-3 and CD3 expression was significantly lower in EGFR and KRAS mutant lung adenocarcinomas than in tumors lacking mutations in these oncogenic drivers (P&lt;0.05).

Conclusion: PD-1, LAG-3 and TIM-3 are differentially expressed in NSCLC, show frequent co-expression and association with elevated CD3+ T-cells. Our results support the biological role of PD-1, LAG-3 and TIM-3 in NSCLC and suggest co-activation of these immune inhibitory pathways in a proportion of cases. Modulation of these receptors could enhance the anti-tumor immune response in lung cancer.

Citation Format: Ila J. Datar, Jun Wang, Nikita Mani, Franz Villarroel-Espindola, Patrick Ryan, Miguel F. Sanmamed, Kristen McEachern, David Jenkins, David L. Rimm, Leiping Chen, Roy Herbst, Kurt Schalper. Simultaneous measurement and clinical significance of PD-1, LAG-3 and TIM-3 in non-small cell lung cancer (NSCLC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5600. doi:10.1158/1538-7445.AM2017-5600