Search

OBJECTIVES: Lymphangiogenesis plays a critical role in the immune response, tumour progression and therapy effectiveness. The aim of this study was to determine whether the interplay between the lymphatic and the blood microvasculature, tumour-infiltrating lymphocytes and the programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) immune checkpoint constitutes an immune microenvironment affecting the clinical outcome of patients with non-small-cell lung cancer. METHODS: Samples from 50 squamous cell carcinomas and 42 adenocarcinomas were subjected to immunofluorescence to detect blood and lymphatic vessels. CD3pos, CD8pos and PD-1pos tumour-infiltrating lymphocytes and tumour PD-L1 expression were assessed by immunohistochemical analysis. RESULTS: Quantification of vascular structures documented a peak of lymphatics at the invasive margin together with a decreasing gradient of blood and lymphatic vessels from the peritumour area throughout the neoplastic core. Nodal involvement and pathological stage were strongly associated with vascularization, and an increased density of vessels was detected in samples with a higher incidence of tumour-infiltrating lymphocytes and a lower expression of PD-L1. Patients with a high PD-L1 to PD-1 ratio and vascular rarefaction had a gain of 10 months in overall survival compared to those with a low ratio and prominent vascularity. CONCLUSIONS: Microvessels are an essential component of the cancer immune microenvironment. The clinical impact of the PD-1/PD-L1-based immune contexture may be implemented by the assessment of microvascular density to potentially identify patients with non-small-cell lung cancer who could benefit from immunotherapy and antiangiogenic treatment.

Purpose: The success of immune checkpoint inhibitors strengthens the notion that tumor growth and regression are immune regulated. To determine whether distinct tissue immune microenvironments differentially affect clinical outcome in non–small cell lung cancer (NSCLC), an extended analysis of PD-L1 and tumor-infiltrating lymphocytes (TIL) was performed. Experimental Design: Samples from resected adenocarcinoma (ADC 42), squamous cell carcinoma (SCC 58), and 26 advanced diseases (13 ADC and 13 SCC) treated with nivolumab were analyzed. PD-L1 expression and the incidence of CD3, CD8, CD4, PD-1, CD57, FOXP3, CD25, and Granzyme B TILs were immunohistochemically assessed. Results: PD-L1 levels inversely correlated with N involvement, although they did not show a statistically significant prognostic value in resected patients. The incidence and phenotype of TILs differed in SCC versus ADC, in which EGFR and KRAS mutations conditioned a different frequency and tissue localization of lymphocytes. NSCLC resected patients with high CD8pos lymphocytes lacking PD-1 inhibitory receptor had a longer overall survival (OS: HR = 2.268; 95% CI, 1.056–4.871, P = 0.03). PD-1-to-CD8 ratio resulted in a prognostic factor both on univariate (HR = 1.952; 95% CI, 1.34–3.12, P = 0.001) and multivariate (HR = 1.943; 95% CI, 1.38–2.86, P = 0.009) analysis. Moreover, low PD-1 incidence among CD8pos cells was a distinctive feature of nivolumab-treated patients, showing clinical benefit with a prolonged progression-free survival (PFS: HR = 4.51; 95% CI, 1.45–13.94, P = 0.004). Conclusions: In the presence of intrinsic variability in PD-L1 expression, the reservoir of PD-1–negative effector T lymphocytes provides an immune-privileged microenvironment with a positive impact on survival of patients with resected disease and response to immunotherapy in advanced NSCLC. Clin Cancer Res; 24(2); 407–19. ©2017 AACR.

Introduction Development of resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors is a clinical issue in patients with epidermal growth factor receptor gene ( EGFR ) - mutated non–small cell lung cancer (NSCLC). The aim of this study was to investigate the potential of combining gefitinib and pemetrexed in preventing the acquisition of resistance to EGFR tyrosine kinase inhibitors in NSCLC cell lines harboring EGFR exon 19 deletion. Methods The effect of different combinatorial schedules of gefitinib and pemetrexed on cell proliferation, cell cycle, apoptosis, and acquisition of gefitinib resistance in PC9 and HCC827 NSCLC cell lines and in PC9 xenograft models was investigated. Results Simultaneous treatment with gefitinib and pemetrexed enhanced cell growth inhibition and cell death and prevented the appearance of gefitinib resistance mediated by T790M mutation or epithelial-to-mesenchymal transition (EMT) in PC9 and HCC827 cells, respectively. In PC9 cells and in PC9 xenografts the combination of gefitinib and pemetrexed, with different schedules, prevented gefitinib resistance only when pemetrexed was the first treatment, given alone or together with gefitinib. Conversely, when gefitinib alone was administered first and pemetrexed sequentially alternated, a negative interaction was observed and no prevention of gefitinib resistance was documented. The mechanisms of resistance that developed in vivo included T790M mutation and EMT. The induction of EMT was a feature of tumors treated with gefitinib when given before pemetrexed, whereas T790M was recorded only in tumors treated with gefitinib alone. Conclusions The combination of gefitinib and pemetrexed is effective in preventing gefitinib resistance; the application of intermittent treatments requires that gefitinib not be administered before pemetrexed.

A prominent role in the pathogenesis of squamous cell carcinoma of the lung (SQCLC) has been attributed to the aberrant activation of the PI3K signaling pathway, due to amplification or mutations of the p110α subunit of class I phosphatidylinositol 3-kinase (PIK3CA) gene. The aim of our study was to determine whether different genetic alterations of PIK3CA affect the biologic properties of SQCLC and to evaluate the response to specific targeting agents in vitro and in vivo. The effects of NVP-BEZ235, NVP-BKM120, and NVP-BYL719 on two-dimensional/three-dimensional (2D/3D) cellular growth, epithelial-to-mesenchymal transition, and invasiveness were evaluated in E545K or H1047R PIK3CA–mutated SQCLC cells and in newly generated clones carrying PIK3CA alterations, as well as in a xenograft model. PIK3CA mutated/amplified cells showed increased growth rate and enhanced migration and invasiveness, associated with an increased activity of RhoA family proteins and the acquisition of a mesenchymal phenotype. PI3K inhibitors reverted this aggressive phenotype by reducing metalloproteinase production, RhoA activity, and the expression of mesenchymal markers, with the specific PI3K inhibitors NVP-BKM120 and NVP-BYL719 being more effective than the dual PI3K/mTOR inhibitor NVP-BEZ235. A xenograft model of SQCLC confirmed that PIK3CA mutation promotes the acquisition of a mesenchymal phenotype in vivo and proved the efficacy of its specific targeting drug NVP-BYL719 in reducing the growth and the expression of mesenchymal markers in xenotransplanted tumors. These data indicate that PIK3CA mutation/amplification may represent a good predictive feature for the clinical application of specific PI3K inhibitors in SQCLC patients. Mol Cancer Ther; 14(8); 1916–27. ©2015 AACR.