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Anaplastic lymphoma kinase (ALK) rearrangements (ALK-Rs) have been identified in 3-7% of all non-small-cell lung cancers (NSCLCs) and represent an important molecular target for NSCLC treatment. The authors discuss the role of ALK-Rs in the prediction of clinical-pathological features of NSCLCs and the technical problems related to their determination in specimens. The authors also describe the preclinical and clinical results derived from the use of ALK inhibitors. ALK-R is generally detected in patients with specific clinical-pathological features: never-smokers, young males, adenocarcinoma histotype and EGF receptor/KRAS wild-type. The diagnosis of ALK-R remains a challenge, implicating the need of a careful filtering of patients. NSCLC patients harboring ALK-R have shown sensitivity to ALK inhibitors even if their activity is limited at the time by the occurrence of mechanisms of resistance. The authors summarize the strategies that in the future could overcome these mechanisms of escape.

The aim of the present work was to identify protein tyrosine phosphatases (PTPs) as novel, candidate tumor suppressor genes in lung cancer. Among the 38 PTPs in the human genome that show specificity for phosphotyrosine, we identified six PTPs by quantitative RT-PCR whose mRNA expression levels were significantly down-regulated in lung cancer-derived cell lines (ie, PTPRE, PTPRF, PTPRU, PTPRK, PTPRD, and PTPN13). After validation in primary samples of non-small cell lung cancer (NSCLC), we selected PTPN13 for further studies. The results presented here demonstrate that PTPN13 is a candidate tumor suppressor gene that is frequently inactivated in NSCLC through the loss of either mRNA and protein expression (64/87, 73%) or somatic mutation (approximately 8%). Loss of PTPN13 expression was apparently due to the loss of one or both copies of the PTPN13 locus at 4q (approximately 26% double deletion and approximately 37% single deletion) but not to promoter methylation. Finally, the manipulation of PTPN13 expression in lung cancer cells (ie, NCI-H292, A549) demonstrated that PTPN13 negatively regulates anchorage-dependent and anchorage-independent growth in vitro and restrains tumorigenicity in vivo, possibly through the control of the tyrosine phosphorylation of both EGFR and HER2. In conclusion, the expression screening of PTPs in lung cancer reported here has identified PTPN13 as a novel candidate tumor suppressor in NSCLC whose loss increases signaling from epidermal growth factor receptor and HER2 tyrosine kinase receptors., (Copyright © 2012 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

Objectives: Lung cancer is the main cause of cancer-related death in Western countries. Despite early diagnosis, approximately 40% of patients have undergone surgical resection for localized non-small cell lung cancer relapse within 24 months after surgery. Current prognostic criteria for patients with non-small cell lung cancer are gradually enriched by the discovery of critical biological markers in surgical samples to better stratify patients with high risk for recurrent and metastatic disease after surgical manipulation. In fact, specific biological features are needed to drive metastasis development and, among these chemokine receptors, when activated, seem to play a relevant role, promoting both neovessels formation and tumoral cell migration., Methods: To this purpose, blood samples from the closed stumps of the pulmonary veins were drawn immediately after major pulmonary surgery in 45 patients with resectable non-small cell lung cancer to evaluate the expression of chemokine CXCL12 receptor, CXCR4, in circulating tumor cells. In addition, primary tumor sections have been used to assess microvascular density (MVD) and vessels invasion and build prognostic tissue micro-array to investigate the expression of CXCL12 receptors CXCR4 and CXCR7., Results: Cells positive for cytokeratins from tumor draining pulmonary venous blood were detectable in 11 cases (23.9%). In 8 out of 11 cases, CK positive cells coexpressed CXCR4. Moreover, in tumoral tissue high CXCR4 expression was significantly associated to high mMVD (p = 0.046), high CXCR7 expression (p = 0.001), adenocarcinoma histotype (p = 0.023), and to the presence of circulating tumoral cells in pulmonary veins (p = 0.001). Finally, vessel invasions relate to high MVD., Conclusion: In conclusion, the results of our study underline the significant potential role of CXCL12 receptors in determining both vessel formation and tumoral cell migration to blood stream, favoring metastasis development.

Aberrant activation of PI3K/AKT signalling represents one of the most common molecular alterations in lung cancer, though the relative contribution of the single components of the cascade to the NSCLC development is still poorly defined. In this manuscript we have investigated the relationship between expression and genetic alterations of the components of the PI3K/AKT pathway [KRAS, the catalytic subunit of PI3K (p110α), PTEN, AKT1 and AKT2] and the activation of AKT in 107 surgically resected NSCLCs and have analyzed the existing relationships with clinico-pathologic features. Expression analysis was performed by immunohistochemistry on Tissue Micro Arrays (TMA); mutation analysis was performed by DNA sequencing; copy number variation was determined by FISH. We report that activation of PI3K/AKT pathway in Italian NSCLC patients is associated with high grade (G3-G4 compared with G1-G2; n = 83; p<0.05) and more advanced disease (TNM stage III vs. stages I and II; n = 26; p<0.05). In addition, we found that PTEN loss (41/104, 39%) and the overexpression of p110α (27/92, 29%) represent the most frequent aberration observed in NSCLCs. Less frequent molecular lesions comprised the overexpression of AKT2 (18/83, 22%) or AKT1 (17/96, 18%), and KRAS mutation (7/63, 11%). Our results indicate that, among all genes, only p110α overexpression was significantly associated to AKT activation in NSCLCs (p = 0.02). Manipulation of p110α expression in lung cancer cells carrying an active PI3K allele (NCI-H460) efficiently reduced proliferation of NSCLC cells in vitro and tumour growth in vivo. Finally, RNA profiling of lung epithelial cells (BEAS-2B) expressing a mutant allele of PIK3 (E545K) identified a network of transcription factors such as MYC, FOS and HMGA1, not previously recognised to be associated with aberrant PI3K signalling in lung cancer.

Background: Sarcomatoid carcinomas are a group of poorly differentiated carcinomas containing a sarcomatoid component with the presence of epithelial-mesenchymal transition., Materials and Methods: To obtain a stabilized cell line, three mediums were used: IMDM, BEBM and IMDM/BEBM. CD44, CD29, CD90, CD133, CD326 antigens, cytokeratins and vimentin were tested by flow cytometry and immunofluorescence assay. Side population, spheres formation, tumorigenicity in vitro and in vivo and cell cycle analysis were analyzed., Results: At day of surgery, cytometric analysis revealed that CD133, CD90 and CD326 levels were very low, CD29 and CD44 were about 80%. After 30 days of culture, CD133 levels increased up to 30%, all cells expressed CD90 and vimentin markers and CD326 was lost. The cells grew only in IMDM/BEBM medium. The cell population was heterogeneous with epithelial and mesenchymal cells. After about 15-30 days, only fibroblast-like cells were observed. LC114 cells were not able to grow as spheres and they did not show a side-population phenotype. The cell cycle analysis confirmed an aneuploid population in the tissue and normal diploid population in cell line., Conclusions: We selected, characterized and stabilized a primary cell line of human pulmonary blastoma by the expression both of stemness and differentiation markers and confirmed the presence of the marker CD133., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

Objective: Emerging evidence suggests that specific sub-populations of cancer cells with stem cell characteristics within the bulk of tumours are implicated in the pathogenesis of heterogeneous malignant tumours. The cells that drive tumour growth have been denoted cancer-initiating cells or cancer stem cells (hereafter CSCs). CSCs have been isolated initially from leukaemias and subsequently from several solid tumours including brain, breast, prostate, colon and lung cancer. This study aimed at isolating and characterising the population of tumour-initiating cells in non-small-cell lung cancer (NSCLC)., Methods: Specimens of NSCLC obtained from 89 patients undergoing tumour resection at the Cancer National Institute of Naples were analysed. Three methods to isolate the tumour-initiating cells were used: (1) flow cytometry analysis for identification of positive cells for surface markers such as CD24, CD29, CD31, CD34, CD44, CD133 and CD326; (2) Hoechst 33342 dye exclusion test for the identification of a side-population characteristic for the presence of stem cells; (3) non-adherent culture condition able to form spheres with stem cell-like characteristics. Definition of the tumourigenic potential of the cells through soft agar assay and injection into NOD/SCID mice were used to functionally define (in vitro and in vivo) putative CSCs isolated from NSCLC samples., Results: Upon flow cytometry analysis of NSCLC samples, CD133-positive cells were found in 72% of 89 fresh specimens analysed and, on average, represented 6% of the total cells. Moreover, the number of CD133-positive cells increased markedly when the cells, isolated from NSCLC specimens, were grown as spheres in non-adherent culture conditions. Cells from NSCLC, grown as spheres, when assayed in soft agar, give rise to a 3.8-fold larger number of colonies in culture and are more tumourigenic in non-obese diabetic (NOD)/severe combined immunodeficiency (SCID) mice compared with the corresponding adherent cells., Conclusions: We have isolated and characterised a population of CD133-positive cells from NSCLC that is able to give rise to spheres and can act as tumour-initiating cells.

Somatic mutation (E17K) that constitutively activates the protein kinase AKT1 has been found in human cancer patients. We determined the role of the E17K mutation of AKT1 in lung cancer, through sequencing of AKT1 exon 4 in 105 resected, clinically annotated non-small cell lung cancer specimens. We detected a missense mutations G-->A transition at nucleotide 49 (that results in the E17K substitution) in two squamous cell carcinoma (2/36) but not in adenocarcinoma (0/53). The activity of the endogenous kinase carrying the E17K mutation immunoprecipitated by tumour tissue was significantly higher compared with the wild-type kinase immunoprecipitated by the adjacent normal tissue as determined both by in vitro kinase assay using a consensus peptide as substrate and by in vivo analysis of the phosphorylation status of AKT1 itself (pT308, pS473) or of known downstream substrates such as GSK3 (pS9/S22) and p27 (T198). Immunostaining or immunoblot analysis on membrane-enriched extracts indicated that the enhanced membrane localization exhibited by the endogenous E17K-AKT1 may account for the observed increased activity of mutant E17K kinase in comparison with the wild-type AKT1 from adjacent normal tissue. In conclusion, this is the first report of AKT1 mutation in lung cancer. Our data provide evidence that, although AKT1 mutations are apparently rare in lung cancer (1.9%), the oncogenic properties of E17K-AKT1 may contribute to the development of a fraction of lung carcinoma with squamous histotype (5.5%).