Combined inhibition of PD-1/PD-L1, Lag-3, and Tim-3 axes augments antitumor immunity in gastric cancer-T cell coculture models.

BACKGROUND: Immunotherapy targeting PD-1 provides a limited survival benefit in patients with unresectable advanced or recurrent gastric cancer (GC). Beside PD-L1, the expression of inhibitory ligands such as CEACAM-1 and LSECtin on GC cells account for this limitation. Here we assessed their expression and immune suppressive effect in GC patients. METHODS: Using multiplexed immunohistochemistry staining, we evaluated the distribution of different inhibitory ligands, including PD-L1, CEACAM-1, LSECtin, and MHC class II, in 365 GC patients. We analyzed their correlations and overall survival (OS) based on the expression of each inhibitory ligand and the independent prognostic factors that affect OS. Subsequently, we evaluated the additive effect of anti-PD-1 mAb or anti-PD-L1 mAb with/without anti-Lag-3 mAb with/without anti-Tim-3 mAb in cytotoxic assay using tumor-antigen specific CTL clones against GC cell lines. RESULTS: Co-expression of the inhibitory ligands for PD-1, Tim-3, and Lag-3 was observed in the largest proportion (34.7%). CEACAM-1, LSECtin, and MHC class II expression showed significant correlation with PD-L1 expression and OS. Multivariable analysis demonstrated that CEACAM-1 low is an independent prognostic factor. Furthermore, combining dual and triple ICIs yielded additive effect on cytotoxicity of CTL clones against each immune inhibitory ligand positive GC cell lines. CONCLUSIONS: Our findings suggested that the expression of inhibitory ligands for Tim-3 and Lag-3 on GC cells serve as potential biomarkers to predict the response to anti-PD-1 therapy and the combinatorial immunotherapy with ICIs targeting for PD-1, Tim-3, and Lag-3 has a therapeutic potential for GC patients.

An LCM-based genomic analysis of SPEM, Gastric Cancer and Pyloric Gland Adenoma in an Asian cohort.

Spasmolytic polypeptide-expressing metaplasia (SPEM) and pyloric gland adenoma (PGA) in the stomach are metaplastic and neoplastic lesions, respectively, in which gastric body glands are replaced by pyloric glands. The aim of this study was to evaluate the genomic profile of SPEM and compare it with intestinal-type gastric cancer (GC) and PGA. Thirteen gastrectomies showing PGA with or without dysplasia, GC and SPEM were retrospectively selected. MUC5AC, MUC6, gastrin, and TFF2 IHC were performed. Lesions were subjected to laser capture microdissection followed by DNA extraction. Forty-three DNA samples were extracted from PGA without cytological dysplasia, PGA with low-grade and high-grade dysplasia and pyloric gland adenocarcinoma, GC, SPEM, and adjacent normal tissue from the body of the stomach and were subjected to exome sequencing for 49 genes that are commonly dysregulated in GC. Sanger sequencing was performed for confirmation. Twenty nonsynonymous mutations were identified in SPEM, and none of these were frameshifts or indels. PGA with or without cytological dysplasia showed a significantly higher number of mutations compared with SPEM. As cytological dysplasia increased from no dysplasia to dysplasia in PGA, the percentage of frameshift mutations, indels, and missense variations increased. Further missense or frameshift mutations were observed in the KRAS, APC, TP53, and CTNNB1 genes in the PGA group. In GC, mutations were observed in the TP53 gene (p.Arg248Gln). Missense mutations in the MUC5AC, KRAS, BRAF, and EZH2 genes were common between SPEM and GC. SPEM showed fewer genomic variations than GC and PGA, and was genomically distinct from the pyloric epithelium in PGA. Stepwise progression of PGA from PGA without dysplasia to PGA with dysplasia/adenocarcinoma was associated an increase in mutations. SPEM appears to be more genomically similar to GC than PGA.

PD-L1 expression is mainly regulated by interferon gamma associated with JAK-STAT pathway in gastric cancer.

Despite multidisciplinary treatment for patients with advanced gastric cancer, their prognosis remains poor. Therefore, the development of novel therapeutic strategies is urgently needed, and immunotherapy utilizing anti-programmed death 1/-programmed death ligand-1 mAb is an attractive approach. However, as there is limited information on how programmed death ligand-1 is upregulated on tumor cells within the tumor microenvironment, we examined the mechanism of programmed death ligand-1 regulation with a particular focus on interferon gamma in an in vitro setting and in clinical samples. Our in vitro findings showed that interferon gamma upregulated programmed death ligand-1 expression on solid tumor cells through the JAK-signal transducer and activator of transcription pathway, and impaired the cytotoxicity of tumor antigen-specific CTL against tumor cells. Following treatment of cells with anti-programmed death ligand-1 mAb after interferon gamma-pre-treatment, the reduced anti-tumor CTL activity by interferon gamma reached a higher level than the non-treatment control targets. In contrast, programmed death ligand-1 expression on tumor cells also significantly correlated with epithelial-mesenchymal transition phenotype in a panel of solid tumor cells. In clinical gastric cancer samples, tumor membrane programmed death ligand-1 expression significantly positively correlated with the presence of CD8-positive T cells in the stroma and interferon gamma expression in the tumor. The results suggest that gastric cancer patients with high CD8-positive T-cell infiltration may be more responsive to anti-programmed death 1/-programmed death ligand-1 mAb therapy.

Determinants of variability of five programmed death ligand-1 immunohistochemistry assays in non-small cell lung cancer samples.

Programmed death ligand-1 (PD-L1) expression as determined by immunohistochemistry (IHC) is potentially predictive of clinical outcome. The aim of this study was to assess the concordance of reported PD-L1 IHC assays and investigate factors influencing variability. Consecutive sections from 20 non-small cell lung cancers (NSCLCs) comprising resection, core biopsy, cytology and pleural fluid samples underwent IHC with 5 different antibody/autostainer combinations: 22C3/Link48, 28-8/BOND-MAX, E1L3N/BOND-MAX, SP142/BenchMark and SP263/BenchMark. PD-L1 RNA levels were assessed using RNAscope. The frequency of positive cases using scoring thresholds from clinical trials was 72%, 33%, 61%, 56%, and 33% for the 5 IHC protocols respectively, and 33% for RNAscope. Pairwise agreement on the classification of cases as positive or negative for PD-L1 expression ranged from 61%-94%. On a continuous scale, the lowest correlation was between 28-8/BOND-MAX and SP142/BenchMark (R2=0.25) and highest was between 22C3/Link48 and E1L3N/BOND-MAX (R2=0.71). When cases were ordered according to tumor cell (TC)%, a similar ranking of cases across IHC protocols could be observed, albeit with different quanta and limits of detection. Single-slide OPAL 7-color fluorescence IHC analysis revealed a high degree of co-localization of staining from the 5 PD-L1 antibodies. Using SP142 antibody in a BOND-MAX protocol led to increased TC% quanta, while retaining a similar ranking of samples according to TC%. The results of this study highlight tumor PD-L1 status can vary significantly according to IHC protocol. Protocol-dependent staining intensities and nominated thresholds for positivity contribute to this variability, while the antibody used appears to be less of a factor.

Significance of immune checkpoint proteins in EGFR-mutant non-small cell lung cancer.

OBJECTIVES: To characterize the expression of PD-L1, PD-1, cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and T-cell immunoglobulin and mucin-domain containing-3 (TIM3) in epidermal growth factor receptor (EGFR) mutant non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: Samples from 90 patients with newly diagnosed advanced stage NSCLC harboring EGFR mutations and treated with first line EGFR tyrosine kinase inhibitors (TKI) within 3 months of diagnosis were stained for CTLA-4, PD-L1, PD-1, TIM-3 and CD3 expression by immunohistochemistry. RESULTS: PD-L1 was present in at least 1% of immune and tumor cells in 44% and 59% of samples, respectively. In multivariate analysis, increased CD3 immune shaped cell (ISC) counts (HR 2.805, p=0.034) and high PD-L1 tumor H-score (HR 3.805, p=0.022) was associated with a shorter progression free survival and high CTLA-4 ISC counts was associated with borderline overall survival significance (HR 1.054, p=0.061). CONCLUSION: Tumor PD-L1 expression was significantly associated with a shorter PFS whereas immune cell CTLA-4 may be prognostic for OS. Our findings support the ongoing development of CTLA-4 and PD1/PD-L1 inhibitors in this important molecularly defined subset of lung adenocarcinoma.

Low Levels of NDRG1 in Nerve Tissue Are Predictive of Severe Paclitaxel-Induced Neuropathy.

INTRODUCTION: Sensory peripheral neuropathy caused by paclitaxel is a common and dose limiting toxicity, for which there are currently no validated predictive biomarkers. We investigated the relationship between the Charcot-Marie-Tooth protein NDRG1 and paclitaxel-induced neuropathy. METHODS/MATERIALS: Archived mammary tissue specimen blocks of breast cancer patients who received weekly paclitaxel in a single centre were retrieved and NDRG1 immunohistochemistry was performed on normal nerve tissue found within the sample. The mean nerve NDRG1 score was defined by an algorithm based on intensity of staining and percentage of stained nerve bundles. NDRG1 scores were correlated with paclitaxel induced neuropathy. RESULTS: 111 patients were studied. 17 of 111 (15%) developed severe paclitaxel-induced neuropathy. The mean nerve NDRG1 expression score was 5.4 in patients with severe neuropathy versus 7.7 in those without severe neuropathy (p = 0.0019). A Receiver operating characteristic (ROC) curve analysis of the mean nerve NDRG1 score revealed an area under the curve of 0.74 (p = 0.0013) for the identification of severe neuropathy, with a score of 7 being most discriminative. 13/54 (24%) subjects with an NDRG1 score < = 7 developed severe neuropathy, compared to only 4/57 (7%) in those with a score >7 (p = 0.017). CONCLUSION: Low NDRG1 expression in nerve tissue present within samples of surgical resection may identify subjects at risk for severe paclitaxel-induced neuropathy. Since nerve biopsies are not routinely feasible for patients undergoing chemotherapy for early breast cancer, this promising biomarker strategy is compatible with current clinical workflow.