To our knowledge, this study represents the first comprehensive and concurrent analysis of major recurrent oncogenic mutations found in a large cohort of lung adenocarcinomas from East Asian never-smokers. Since drugs are now available that target mutant EGFR, HER2, and ALK, respectively, this result indicates that prospective mutation testing in these patients should successfully assign a targeted therapy in the majority of cases.
Introduction
Somatic LKB1 mutations are found in lung adenocarcinomas at different frequencies in Caucasian and East Asian (Japanese and Korean) populations. This study was designed to characterize the frequency of LKB1 mutations, their relationship to EGFR and KRAS mutations, and their associated clinicopathologic characteristics in Chinese patients.
Methods
Two hundred thirty-nine lung adenocarcinomas consecutively collected from October 2007 to July 2009 were dissected into 3 to 4 small (3 mm) pieces for histopathological analyses of tumor content. Genomic DNA and/or cDNA from 86 samples with more than 70% tumor content were used for sequencing of LKB1 (exons 1–9), EGFR (exons 18–21), and KRAS (exon 2). LKB1 germline mutation status was determined by sequencing of genomic DNA from matched histologically distant lung tissues that are histologically normal.
Results
6.9% of lung adenocarcinomas harbored LKB1 somatic mutations. A total of 10.5% of patients had an LKB1 germline polymorphism, F354L. Interestingly, in two of these patients, tumors displayed loss of heterozygosity at this allele. EGFR kinase domain and KRAS mutations were found in 66.3% and 2.3% of Chinese lung adenocarcinomas, respectively. Concurrent LKB1 and EGFR somatic mutations were observed in one patient. Both KRAS-mutant tumors harbored LKB1 mutations.
Conclusions
These data provide important clinical and molecular characteristics of lung adenocarcinomas from Chinese patients.
Summary. Background: The interaction of glycoprotein (GP) Iba with von Willebrand factor (VWF) initiates platelet adhesion, and simultaneously triggers intracellular signaling cascades leading to platelet aggregation and thrombus formation. Some of the signaling events are similar to those occurring during apoptosis, however, it is still unclear whether platelet apoptosis is induced by the GPIba-VWF interaction. Objectives: To investigate whether the GPIba-VWF interaction induces platelet apoptosis and the role of 14-3-3f in apoptotic signaling. Methods: Apoptotic events were assessed in platelets or Chinese hamster ovary (CHO) cells expressing wild-type (1b9) or mutant GPIb-IX interacting with VWF by flow cytometry or western blotting. Results: Ristocetin-induced GPIba-VWF interaction elicited apoptotic events in platelets, including phosphatidylserine exposure, elevations of Bax and Bak, gelsolin cleavage, and depolarization of mitochondrial inner transmembrane potential. Apoptotic events were also elicited in platelets exposed to pathologic shear stresses in the presence of VWF; however, the shear-induced apoptosis was eliminated by the anti-GPIba antibody AK2. Furthermore, apoptotic events occurred in 1b9 cells stimulated with VWF and ristocetin, but were significantly diminished in two CHO cell lines expressing mutant GPIb-IX with GPIba truncated at residue 551 or a serine-to-alanine mutation at the 14-3-3f-binding site in GPIba. Conclusions: This study demonstrates that the GPIba-VWF interaction induces apoptotic events in platelets, and that the association of 14-3-3f with the cytoplasmic domain of GPIba is essential for apoptotic signaling. This finding may suggest a novel mechanism for platelet clearance or some thrombocytopenic diseases.
Haemonchus contortus is a parasitic gastrointestinal nematode, and its excretory and secretory products (HcESPs) interact extensively with the host cells. In this study, we report the interaction of proteins from HcESPs at different developmental stages to goat peripheral blood mononuclear cells (PBMCs) in vivo using liquid chromatography-tandem mass spectrometry. A total of 407 HcESPs that interacted with goat PBMCs at different time points were identified from a H. contortus protein database using SEQUEST searches. The L4 and L5 stages of H. contortus represented a higher proportion of the identified proteins compared with the early and late adult stages. Both stage-specific interacting proteins and proteins that were common to multiple stages were identified. Forty-seven interacting proteins were shared among all stages. The gene ontology (GO) distributions of the identified goat PBMC-interacting proteins were nearly identical among all developmental stages, with high representation of binding and catalytic activity. Cellular, metabolic and single-organism processes were also annotated as major biological processes, but interestingly, more proteins were annotated as localization processes at the L5 stage than at the L4 and adult stages. Based on the clustering of homologous proteins, we improved the functional annotations of un-annotated proteins identified at different developmental stages. Some unnamed H. contortus ATP-binding cassette proteins, including ADP-ribosylation factor and P-glycoprotein-9, were identified by STRING protein clustering analysis.
The serine/threonine kinase LKB1 is a well-characterized tumor suppressor that governs diverse cellular processes, including growth, polarity, and metabolism. Somatic-inactivating mutations in LKB1 are observed in about 15% to 30% of non-small cell lung cancers (NSCLC). LKB1 inactivation confers lung adenocarcinomas (ADC) with malignant features that remain refractory to therapeutic intervention. YAP activation has been linked to LKB1 deficiency, but the role of YAP in lung ADC formation and progression is uncertain. In this study, we showed that ectopic expression of YAP in type II alveolar epithelial cells led to hyperplasia in mouse lungs.
YAP overexpression in the KrasG12D lung cancer mouse model accelerated lung ADC progression. Conversely, YAP deletion dramatically delayed the progression of lung ADC in LKB1-deficient Kras G12D mice. Mechanistic studies identified the antiapoptotic oncoprotein survivin as the downstream mediator of YAP responsible for promoting malignant progression of LKB1-deficient lung ADC. Collectively, our findings identify YAP as an important contributor to lung cancer progression, rationalizing YAP inhibition in the context of LKB1 deficiency as a therapeutic strategy to treat lung ADC.Cancer Res; 75(21); 4450-7. Ó2015 AACR.
BackgroundMonocytes and T cells are two major subpopulations of peripheral blood mononuclear cells (PBMC) and play an essential role in the innate and adaptive immune systems. Different members of the galectin family show multiple and distinct regulatory effects on different cell types. Previous studies have demonstrated that the galectin from Haemonchus contortus (Hco-gal-m) performed immunomodulatory effects on goat PBMC, however, which subpopulation of PBMC is the primary target of Hco-gal-m and whether the immune modulations share the same mechanism remain unclear.MethodsIn this study, the developmental expression of Hco-gal-m was analyzed by RT-PCR and Western blot analysis. The distribution of Hco-gal-m in adult worm was detected by an immunohistochemical test. The binding activity of the recombinant Hco-gal-m (rHco-gal-m) on goat monocytes and T cells were assessed by flow cytometry. The immunomodulatory effects of Hco-gal-m on cytokine secretion, cell activation and apoptosis were observed by co-incubation of rHco-gal-m with goat monocytes and T cells.ResultsHco-gal-m was expressed in L4 as well as adult worms and predominantly localized at the internal surface of the worm guts. rHco-gal-m could bind to both monocytes and T cells. The engagement of rHco-gal-m decreased the production of IL-6, IL-10 and TNF-α in T cells, however, it significantly increased the secretion of IL-10 in monocytes. After rHco-gal-m exposure, the expression of MHC-II on monocytes and that of CD25 on T cells were restricted. Consequently, T cell proliferations were potently inhibited by rHco-gal-m. In addition, rHco-gal-m induced apoptosis in T cells, but not significantly in monocytes.ConclusionsOur results indicated that rHco-gal-m modulated goat monocytes and T cell function in different patterns.Electronic supplementary materialThe online version of this article (doi:10.1186/1756-3305-7-342) contains supplementary material, which is available to authorized users.
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