Neuroendocrine tumors are a unique malignant neoplasm that can arise from the respiratory tree. Although well-differentiated bronchial neuroendocrine tumors (also called carcinoid tumors) are reported to account for approximately 25% of all neuroendocrine tumors, they represent only 1% to 2% of all lung cancers. The epidemiology, clinical behavior, and treatment of neuroendocrine carcinoid tumors differ significantly from other lung malignancies. In this article, the recent data regarding these tumors were reviewed with attention to the treatment modalities used. Although conventional cytotoxic therapy has not been reported to demonstrate much promise in this entity over the past 4 decades, newer molecular targeted agents including those that targeted angiogenesis and the mammalian target of rapamycin (mTOR) Well-differentiated neuroendocrine, or carcinoid, tumors are a unique class of malignancies capable of producing hormones identical to those from the nervous system. Although the first carcinoid tumor described was in the ileum, neuroendocrine malignancies are a family of malignancies found throughout the body. Tumors of the bronchial tree in particular account for approximately 25% of all well-differentiated neuroendocrine tumors (Table 1). [1][2][3] However, compared with other malignancies of the bronchoalveolar tree, these well-differentiated neuroendocrine tumors are rare, accounting for only 1% of all lung cancers. 3 The pathologic spectrum of neuroendocrine malignancies ranges from low-grade carcinoid to aggressive small cell lung cancer. The low-grade and intermediate-grade neuroendocrine malignancies, also known as typical and atypical carcinoid, will be the focus of this review. The distinct features of this malignancy include its pathologic characteristics, clinical behavior, epidemiology, prognosis, and treatment.
As we age, there is an increased risk for the development of pulmonary diseases, including infections, but few studies have considered changes in lung surfactant and components of the innate immune system as contributing factors to the increased susceptibility of the elderly to succumb to infections. We and others have demonstrated that human alveolar lining fluid (ALF) components, such as surfactant protein (SP)-A, SP-D, complement protein C3, and alveolar hydrolases, play a significant innate immune role in controlling microbial infections. However, there is a lack of information regarding the effect of increasing age on the level and function of ALF components in the lung. Here we addressed this gap in knowledge by determining the levels of ALF components in the aging lung that are important in controlling infection. Our findings demonstrate that pro-inflammatory cytokines, surfactant proteins and lipids, and complement components are significantly altered in the aged lung in both mice and humans. Further, we show that the aging lung is a relatively oxidized environment. Our study provides new information on how the pulmonary environment in old age can potentially modify mucosal immune responses, thereby impacting pulmonary infections and other pulmonary diseases in the elderly population.
Purpose
We performed genome-wide microRNA-sequencing (miRNA-seq) in primary cancer tissue from lung adenocarcinoma patients to identify markers for the presence of lymph node metastasis.
Experimental Design
Markers for lymph node metastasis identified by sequencing were validated in a separate cohort using QPCR. After additional validation in the TCGA dataset, functional characterization studies were performed in vitro.
Results
MiR-31 was upregulated in lung adenocarcinoma tissues from patients with lymph node metastases compared to those without lymph node metastases. We confirmed miR-31 to be up-regulated in lymph node positive patients in a separate patient cohort (p=0.009, t-test), and to be expressed higher in adenocarcinoma tissue than in matched normal adjacent lung tissues (p<0.0001, paired t-test). MiR-31 was then validated as a marker for lymph node metastasis in an external validation cohort of 233 lung adenocarcinoma cases of the TCGA (p=0.031, t-test). In vitro functional assays showed that miR-31 increases cell migration, invasion, and proliferation in an ERK1/2 signaling dependent manner. Of note, miR-31 was a significant predictor of survival in a multivariate cox regression model even when controlling for cancer staging. Exploratory in silico analysis showed that low expression of miR-31 is associated with excellent survival for T2N0 patients.
Conclusions
We applied microRNA-seq to study microRNomes in lung adenocarcinoma tissue samples for the first time and identified potentially a microRNA predicting the presence of lymph node metastasis and survival outcomes in lung adenocarcinoma patients.
Amplification of oncogenes is an important mechanism that can cause gene overexpression and contributes to tumor development. The identification of amplified regions might have both prognostic and therapeutic significance. We used primary lung carcinomas and lung cancer cell lines for restriction landmark genomic scanning (RLGS) to identify novel amplified sequences. Enhanced RLGS fragments that indicate gene amplification were observed in primary tumors and lung cancer cell lines of both non-small cell lung cancer and small cell lung cancer. We identified one novel amplicon on chromosome 11q22, in addition to previously reported amplicons that include oncogenes MYCC, MYCL1 and previously identified amplification of chromosomal regions 6q21 and 3q26-27. Amplification of 11q22 has been reported in other types of cancer and was refined to an approximately 1.19 Mbp region for which the complete sequence is available. Based on a patient sample with a small region of low-level amplification we were able to further narrow this region to 0.92 Mbp. Genes localized in this region include two inhibitors of apoptosis (cIAP1 and cIAP2). Immunohistochemistry and western blot analysis identified cIAP1 and cIAP2 as potential oncogenes in this region as both are overexpressed in multiple lung cancers with or without higher copy numbers.
Septal capillary injury accompanied by direct and indirect immunofluorescent evidence of humoral immunity is a frequent finding on transbronchial biopsies. The findings suggest that humoral immunity to endothelial-based alloantigen is a common occurrence in lung grafts and may be a critical factor in chronic graft dysfunction.
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