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Background and objective Lung cancer is a malignant with high incidence and mortality and adenocarcinoma is among the most popular subtypes. Epidermal growth factor receptor (EGFR) mutation is one of the most important driver mutations for lung adenocarcinoma and EGFR-tyrosine kinase inhibitor (TKI) will benefit those patients with sensitive EGFR mutations. Recently, immune checkpoint inhibitor (ICI) therapy, provide a new breakthrough treatment for lung cancer patients. Whereas immunotherapy as an emerging treatment does not benefit patients with EGFR mutations, for which mechanistic studies are poorly defined and focused on the link of EGFR mutations and programmed cell death-ligand 1 (PD-L1) expression, we speculate that the different immune microenvironment associated with the two classes of patients. Methods Lung adenocarcinoma datasets were collected from the Cancer Genome Atlas (TCGA) database, and clinical information and gene expression profiles were downloaded. The immune related lymphocyte infiltration in TCGA database were generated through timer 2.0 GSEA was used to analyze the difference of pathway expression between EGFR mutant patients and wild type patients. Results EGFR mutation was more frequently among women and never smokers. Immunoinfiltration analysis showed that patients with EGFR mutation tends to have more tumor associated fibroblasts, common myeloid progenitor cells, hematopoietic stem cells, effector CD4+ T cells and natural killer T cells infiltration, and less memory B cells, naïve B cells, plasma B cells, plasmacytoid dendritic cells, memory CD4+ T cells, CD4+ helper T cells 2, naive CD8+ T cells, CD8+ T cells and central memory CD8+ T cells infiltration. Moreover, patients with more infiltration of CD8+ T cells, natural killer T cells, memory B cells and hematopoietic stem cells, tends have better prognosis (Log-rank test, P=0.017, 0.0093, 0.018, 0.016). However, the patients with more CD4+ T th2 infiltration in the tumor tends to have worse prognosis (Log-rank test, P=0.016). Furthermore, the results of gene set enrichment analysis showed that compared with the lung adenocarcinoma patients with EGFR wild type, the three pathways positive regulation of natural killer (NK) cell-mediated immune response to tumor cells, NK cell activation involved in immune response, and NK cell-mediated immune response to tumor cells related to natural killer cells in patients with EGFR mutation were down regulated, while the pathway the positive regulation of cytokine secretion involved in immune response was up-regulated in EGFR mutation patients. Conclusion The tumour microenvironment of patients with EGFR mutations lacks potent tumour killing effector cells and appears dysfunctional with effector cells. This may be a potential reason for the poor efficacy of immunotherapy in patients with EGFR mutations.

Background and objective Lung cancer is the most common malignancy world-wide. Small cell lung cancer is the deadliest subtype of lung cancer, which features such as rapid growth, early metastasis, and high vascularization. Apatinib is a vascular endothelial growth factor receptor 2 inhibitor independently developed in China, which has a significant inhibition in a variety of solid tumors. The purpose of this study is to investigate the effects of Apatinib alone or Apatinib combined with mammalian target of rapamycin (mTOR) inhibitor, CCI-779, on small cell lung cancer cell line NCI-H446 in vitro. Methods The small cell lung cancer cell line NCI-H446 was grew in vitro. The effects of Apatinib alone or Apatinib combined with CCI-779 on proliferation, apoptosis, cell cycle and migration of NCI-H446 small cell lung cancer cells were detected by CCK8; FACS and transwell assays were also carried out; Western blot assays were used to detect vascular endothelial growth factor and cell cycle related protein expression. Results CCK8 assays showed that high concentration of Apatinib could inhibit the proliferation of NCI-H446 cells. Apoptosis assays showed that high concentration of Apatinib could induce NCI-H446 cell apoptosis. Transwell assays showed that high concentration of Apatinib could inhibit NCI-H446 cell migration. After combined with mTOR inhibitor CCI-779, low concentration of Apatinib could inhibit the proliferation and migration of NCI-H446 small cell lung cancer cells and induce apoptosis. Conclusion Apatinib has a concentration-dependent effect on the small cell lung cancer cell line NCI-H446. High concentration of Apatinib can inhibit the proliferation and migration of NCI-H446 small cell lung cancer cells, induce apoptosis. Apatinib combined with the mTOR inhibitor CCI-779 can sensitize the NCI-H446 cells to Apatinib.

Background and objective Rb is an important tumor suppressor gene that regulates cell cycle progression. Rb dysfunction can lead to over proliferation of cells and lead to the occurrence of tumor. Loss or reduced Rb expression as well as over phosphorylation of Rb are important mechanisms of Rb dysfunction. The mutated epidermal growth factor receptor (EGFR) gene is an important driver gene in lung adenocarcinoma, and plays an important role in the development of lung cancer. The purpose of this study was to investigate the status of Rb in lung adenocarcinoma patients with EGFR mutations and define the clinicopathologic features. Methods 23 cases pulmonary adenocarcinoma patients with EGFR mutations were collected. The status of Rb and pRb-780, pRb-795 were determined byimmunohistochemistry. Results Loss or reduced Rb expression were detected in 16 of 23 samples (69.6%). pRb-780 and pRb-795 over-expressed were identified in 17 (73.9%) and 16 (69.6%) of 23 samples respectively. All the 23 patients had showed loss/reduced Rb expression or over-expressed Rb phosphorylation. Further analysis showed that over expression of pRb-780 and pRb-795 occurred more frequently in advanced patients. Conclusion Aberrant expressionof Rb is frequently occurred in lung adenocarcinoma patients with EGFR mutations and may be an important pathogenesis in patients with lung adenocarcinoma.