Purpose: There is currently no reliable biomarker to predict who would benefit from anti-PD-1/PD-L1 inhibitors. We comprehensively analyzed the immunogenomic properties in The Cancer Genome Atlas (TCGA) according to the classification of tumor into four groups based on PD-L1 status and tumor-infiltrating lymphocyte recruitment (TIL), a combination that has been suggested to be a theoretically reliable biomarker of anti-PD-1/PD-L1 inhibitors.Experimental Design: The RNA expression levels of PD-L1 and CD8A in the samples in the pan-cancer database of TCGA (N ¼ 9,677) were analyzed. Based on their median values, the samples were classified into four tumor microenvironment immune types (TMIT). The mutational profiles, PD-L1 amplification, and viral association of the samples were compared according to the four TMITs.Results: The proportions of TMIT I, defined by high PD-L1 and CD8A expression, were high in lung adenocarcinoma (67.1%) and kidney clear cell carcinoma (64.8%) among solid cancers. The number of somatic mutations and the proportion of microsatellite instable-high tumor in TMIT I were significantly higher than those in other TMITs, respectively (P < 0.001). PD-L1 amplification and oncogenic virus infection were significantly associated with TMIT I, respectively (P < 0.001). A multivariate analysis confirmed that the number of somatic mutations, PD-L1 amplification, and Epstein-Barr virus/human papillomavirus infection were independently associated with TMIT I.Conclusions: TMIT I is associated with a high mutational burden, PD-L1 amplification, and oncogenic viral infection. This integrative analysis highlights the importance of the assessment of both PD-L1 expression and TIL recruitment to predict responders to immune checkpoint inhibitors.

Solid tumors elicit a detectable immune response including the infiltration of tumor-associated macrophages (TAMs). Unfortunately, this immune response is co-opted into contributing toward tumor growth instead of preventing its progression. We seek to reestablish an antitumor immune response by selectively targeting surface receptors and endogenous signaling processes of the macrophage subtypes driving cancer progression. RP-182 is a synthetic 10-mer amphipathic analog of host defense peptides that selectively induces a conformational switch of the mannose receptor CD206 expressed on TAMs displaying an M2-like phenotype. RP-182–mediated activation of this receptor in human and murine M2-like macrophages elicits a program of endocytosis, phagosome-lysosome formation, and autophagy and reprograms M2-like TAMs to an antitumor M1-like phenotype. In syngeneic and autochthonous murine cancer models, RP-182 suppressed tumor growth, extended survival, and was an effective combination partner with chemo- or immune checkpoint therapy. Antitumor activity of RP-182 was also observed in CD206high patient-derived xenotransplantation models. Mechanistically, via selective reduction of immunosuppressive M2-like TAMs, RP-182 improved adaptive and innate antitumor immune responses, including increased cancer cell phagocytosis by reprogrammed TAMs.

Virus-associated malignancies and sarcomatoid cancers correlate with high PD-L1 expression, however, underlying mechanisms remain controversial. We evaluated the correlation between PD-L1 expression and epithelial-mesenchymal transition (EMT) in head and neck squamous cell carcinomas (HNSCC). Tumor tissues from 50 patients with HNSCC were evaluated for PD-L1 by immunohistochemistry, which showed 32 (64.0%) were PD-L1 positive (PD-L1+). Interestingly, PD-L1 expression was significantly associated with EMT (P = 0.010), as assessed by low E-cadherin and high vimentin expression. The overall survival of PD-L1+ patients with EMT features was significantly worse than those without EMT features (P = 0.007). In an independent validation cohort (N = 91), as well as in HNSCC cases of The Cancer Genome Atlas (TCGA) and the Cancer Cell Line Encyclopedia, high PD-L1 expression was also associated with the high probability of an EMT signature, referred from the GEO dataset, GSE4824. Survival analysis confirmed PD-L1+/EMT+ patients had a poorer prognosis than PD-L1+/EMT- patients in the TCGA cohort. PD-L1 positivity can thus be divided into two categories according to the absence or presence of EMT. PD-L1 expression is also independently associated with EMT features in HNSCC.

Colorectal cancer is driven by the accumulation of driver mutations, but the contributions of specific mutations to different steps in malignant progression are not fully understood. In this study, we generated mouse models harboring different combinations of key colorectal cancer driver mutations () in intestinal epithelial cells to comprehensively investigate their roles in the development of primary tumors and metastases. mutation caused intestinal adenomas and combination with mutation or deletion induced submucosal invasion. The addition of mutation yielded epithelial-mesenchymal transition (EMT)-like morphology and lymph vessel intravasation of the invasive tumors. In contrast, combinations of with and mutation were insufficient for submucosal invasion, but still induced EMT-like histology. Studies using tumor-derived organoids showed that was critical for liver metastasis following splenic transplantation, when this mutation was combined with either plus or deletion, with the highest incidence of metastasis displayed by tumors with a genotype. RNA sequencing analysis of tumor organoids defined distinct gene expression profiles characteristic for the respective combinations of driver mutations, with upregulated genes in tumors found to be similarly upregulated in specimens of human metastatic colorectal cancer. Our results show how activation of Wnt and Kras with suppression of TGFβ signaling in intestinal epithelial cells is sufficient for colorectal cancer metastasis, with possible implications for the development of metastasis prevention strategies. These findings illuminate how key driver mutations in colon cancer cooperate to drive the development of metastatic disease, with potential implications for the development of suitable prevention strategies. .

Immunotherapy has emerged as a promising anti-cancer treatment, however, little is known about the genetic characteristics that dictate response to immunotherapy. We develop a transcriptional predictor of immunotherapy response and assess its prediction in genomic data from ~10,000 human tissues across 30 different cancer types to estimate the potential response to immunotherapy. The integrative analysis reveals two distinct tumor types: the mutator type is positively associated with potential response to immunotherapy, whereas the chromosome-instable type is negatively associated with it. We identify somatic mutations and copy number alterations significantly associated with potential response to immunotherapy, in particular treatment with anti-CTLA-4 antibody. Our findings suggest that tumors may evolve through two different paths that would lead to marked differences in immunotherapy response as well as different strategies for evading immune surveillance. Our analysis provides resources to facilitate the discovery of predictive biomarkers for immunotherapy that could be tested in clinical trials.

We co-assessed PD-L1 expression and CD8+ tumor-infiltrating lymphocytes in gastric cancer (GC), and categorized into 4 microenvironment immune types. Immunohistochemistry (PD-L1, CD8, Foxp3, E-cadherin, and p53), PD-L1 mRNA in situ hybridization (ISH), microsatellite instability (MSI), and EBV ISH were performed in 392 stage II/III GCs treated with curative surgery and fluoropyrimidine-based adjuvant chemotherapy, and two public genome databases were analyzed for validation. PD-L1+ was found in 98/392 GCs (25.0%). The proportions of immune types are as follows: PD-L1+/CD8High, 22.7%; PD-L1−/CD8Low, 22.7%; PD-L1+/CD8Low, 2.3%; PD-L1−/CD8High, 52.3%. PD-L1+/CD8High type accounted for majority of EBV+ and MSI-high (MSI-H) GCs (92.0% and 66.7%, respectively), and genome analysis from public datasets demonstrated similar pattern. PD-L1−/CD8High showed the best overall survival (OS) and PD-L1−/CD8Low the worst (P < 0.001). PD-L1 expression alone was not associated with OS, however, PD-L1−/CD8High type compared to PD-L1+/CD8High was independent favorable prognostic factor of OS by multivariate analysis (P = 0.042). Adaptation of recent molecular classification based on EBV, MSI, E-cadherin, and p53 showed no significant survival differences. These findings support the close relationship between PD-L1/CD8 status based immune types and EBV+, MSI-H GCs, and their prognostic significance in stage II/III GCs.

Programmed death-ligand 1 (PD-L1) expression is regarded as a predictive marker for anti-PD-1/PD-L1 therapy. The purpose of study was to explore the changes in PD-L1 expression in head and neck squamous cell carcinoma (HNSCC) during treatment. Paired HNSCC tissues prior to and after cisplatin-based treatment were evaluated to determine PD-L1 protein expression by immunohistochemistry. Among the 35 HNSCC patient samples, PD-L1 expression status changed after treatment in 37.1% (13/35) of samples. Among the 13 patients whose baseline PD-L1 was negative, PD-L1 expression was increased in 9 cases (69.2%) and remained negative in 4 cases (30.8%, P = 0.003). Patients exposed to cisplatin generally showed PD-L1 up-regulation (83.3%, P = 0.037) compared to those not exposed to cisplatin (57.1%, P = 0.072). To validate these findings in vitro, changes in PD-L1 expression in HNSCC cell lines (Detroit-562, PCI-13, SNU-1041, SNU-1066, SNU-1076, and FaDu) were analyzed by western blotting and flow cytometry after treatment with cisplatin and interferon-gamma. In HNSCC cell lines, PD-L1 expression was significantly up-regulated after cisplatin, along with phosphor-MAPK/ERK kinase up-regulation. In conclusion, PD-L1 expression in HNSCC may be altered during cisplatin treatment, activating the MAPK/ERK kinase pathway.

Purpose: Chemotherapy plus trastuzumab is standard of care for HER2-positive advanced gastric cancer (AGC). However, not all patients with HER2-positive AGC seem to benefit from trastuzumab. We evaluated the association between treatment outcomes with trastuzumab and HER2 status in patients with HER2-positive AGC.Experimental Design: We enrolled 126 patients with HER2-positive AGC treated with trastuzumab plus chemotherapy in a training cohort. HER2 IHC (N ¼ 126), HER2/CEP17 ratio (N ¼ 66), and HER2 gene copy number (GCN; N ¼ 59) were analyzed, and the optimal values for discriminating overall survival (OS) were determined using receiver operating characteristic (ROC) curve analysis. We validated the findings from the training cohort using an independent validation cohort (N ¼ 72).Results: Patients with HER2 IHC 3þ showed significantly longer OS (29 vs. 15.3 months; P ¼ 0.025) than patients with IHC2þ. An HER2/CEP17 ratio of 4.48 was the optimal cutoff for predicting longer OS (26.9 vs. 14.7 months; P ¼ 0.027). In subgroup analysis, treatment outcomes of patients with IHC 3þ were not influenced by the level of HER2 gene amplification. However, in patients with IHC 2þ, an HER2/ CEP17 ratio more than 3.69 and HER2 GCN more than 7.75 were positive predictive factors for better outcomes with trastuzumab-based chemotherapy. These findings were confirmed in both the validation cohort and the combined cohort.Conclusions: HER2 IHC status, HER2/CEP17 ratio, and HER2 GCN were correlated with clinical outcomes of trastuzumabbased treatment in HER2-positive AGC. Clinical outcomes of patients with IHC 2þ were strongly dependent on the HER2/CEP17 ratio and HER2 GCN.