STK33 plays an important positive role in the development of human large cell lung cancers with variable metastatic potential.

Serine/threonine kinase 33 (STK33) is a novel protein that has attracted considerable interest in recent years. Previous research has revealed that STK33 expression plays a special role in cancer cell proliferation. However, the mechanisms of STK33 induction of cancer cells remain largely unknown. In this study, it is demonstrated that STK33 expression varies in NL9980 and L9981 cells which are homogeneous cell lines with similar genetic backgrounds. STK33 can promote cell migration and invasion and suppress p53 gene expression in the NL9980 and L9981 cells. In addition, this protein also promotes epithelial-mesenchymal transition (EMT). Moreover, STK33 knockdown decreases tumor-related gene expression and inhibits cell migration, invasion, and EMT, suggesting that STK33 may be a mediator of signaling pathways that are involved in cancer. In conclusion, our results suggest that STK33 may be an important prognostic marker and a therapeutic target for the metastatic progression of human lung cancer.

Cyclooxygenase-2 expression is a prognostic biomarker for non-small cell lung cancer patients treated with adjuvant platinum-based chemotherapy.

BACKGROUND: Adjuvant chemotherapy after the resection of stage IB-IIIA non-small cell lung cancer (NSCLC) is now the standard of care based on large-scale phase III trials and a meta-analysis. However, chemotherapy has plateaued in terms of its efficacy, and the search for treatment prediction biomarkers is imperative for the further identification of treatable subgroups. Therefore, we investigated the significance of cyclooxygenase-2 (Cox-2) expression and the applicability of a Cox-2 inhibitor in patients who had received adjuvant chemotherapy. METHODS: We conducted a retrospective review of data from 97 patients who had received adjuvant chemotherapy. The adjuvant chemotherapy consisted of an oral tegafur agent (OT) or platinum-based chemotherapy (PB). The criteria for regimen selection were based on a discussion among the cancer board and enrollment in a clinical trial. Immunohistochemical staining (IHC) for Cox-2 was performed, and the correlation between Cox-2 expression and disease-free survival (DFS) was evaluated. RESULTS: IHC showed that 56 cases (57.7%) were positive for Cox-2. The rate of Cox-2 expression was similar for the PB and OT groups. Among the patients who received PB, the DFS of the patients with Cox-2 expression was significantly poorer than that of the patients without Cox-2 expression (P = 0.017), but there was no significant difference among the patients who received OT (P = 0.617). In a multivariate analysis, Cox-2 expression and lymph node metastasis were independent predictors of DFS among patients who received PB. CONCLUSIONS: Cox-2 expression was a powerful predictor of DFS among patients who received PB as an adjuvant chemotherapy. Further study investigating the use of a Cox-2 inhibitor for adjuvant chemotherapy is needed.

[Significance of serum neuron-specific enolase before treatment in predicting brain metastases and prognosis of advanced non-small cell lung cancer].

OBJECTIVE: To explore the value of serum neuron-specific enolase (NSE) before treatment in predicting brain metastases and prognosis of advanced non-small cell lung cancer (NSCLC). METHODS: A total of 128 hospitalized patients with advanced NSCLC from Jan 2012 to Mar 2012 were followed up, and their clinicopathological data, serum NSE, carcinoembryonic antigen, cytokeratin 21-1 (cyfra21-1) levels, albumin (ALB), white blood cell (WBC) before treatment were analyzed retrospectively to determine the factors affecting brain metastasis and prognosis of advanced NSCLC. RESULTS: Among the 128 NSCLC patients, 90 cases were of adenocarcinoma, 30 cases were of squamous cell carcinoma, and 8 cases were of large cell carcinoma. The median levels of pre-treatment NSE, CEA and cyfra21-1 were 13.6 ng/ml, 7.8 ng/ml and 6.1 ng/ml, respectively. The average levels of ALB and WBC were (35.41 ± 5.60) g/L and (8.16 ± 2.53) × 109/ml, respectively. Multi-variate logistic regression analysis showed that serum NSE before treatment was associated with brain metastasis of advanced NSCLC (P = 0.030). Pre-treatment NSE levels were (34.18 ± 28.48) ng/ml in 28 patients with brain metastasis and (13.87 ± 4.49) ng/ml in 98 patients without brain metastasis (P < 0.05). The median survival time were 3.5 months in patients with normal levels of NSE, and 10.7 months in patients with elevated levels of NSE pre-treatment (P < 0.05). CONCLUSIONS: A higher pre-treatment level of NSE is closely correlated with brain metastasis of advanced NSCLC, and can be used as a predictor of brain metastases in advanced NSCLC. High pre-treatment levels of NSE indicate a poor prognosis in advanced NSCLC patients.

COX-2 overexpression and -8473 T/C polymorphism in 3' UTR in non-small cell lung cancer.

A new class of compounds targeting cyclooxygenase 2 (COX-2) together with other different clinically used therapeutic strategies has recently shown a promise for the chemoprevention of several solid tumors including lung cancer. The aim was to study the possible role of COX-2 -8473 T/C NP and its expression in the pathogenesis of non-small cell lung cancer. One hundred ninety non-small cell lung cancer (NSCLC) patients and 200 healthy age-, sex-, and smoking-matched controls were used for polymorphic analysis, and 48 histopathologically confirmed NSCLC patients were analyzed for COX-2 messenger RNA (mRNA) and protein expression. Our results showed that the frequencies of variant genotypes 8473 CT/CC were significantly less common in the cases (30.0%) than in the controls (36%), suggesting that the 8473 C variant allele is related with lower susceptibility in NSCLC (OR = 0.79, 95% CI 0.54-1.4). However, the frequency of COX-2 -8473 TC and CC genotypes were significantly associated with age in NSCLC (P = 0.02). Quantitative real-time expression analysis showed a significant increase in the COX-2 mRNA in tumor tissues as compared to their adjacent normal tissues [delta cycle threshold (ΔCT) = 9.25 ± 4.67 vs 5.63 ± 3.85, P = 0.0001]. Multivariate logistic regression analyses revealed that the COX-2 expression was associated significantly with age (P = 0.044). Also, an increasing trend was observed in stages I and II and in female patients compared to stages III and IV and male patients, respectively, but no statistical significance was observed. However, COX-2 mRNA expression shown no association with the -8473 C variant allele. Our findings indicate that the COX-2 T8473C polymorphism may contribute to NSCLC cancer susceptibility in the Kashmiri population, while our expression analysis revealed a significant increase of COX-2 in tumor tissues as compared to their adjacent normal tissues, suggesting that it could become an important therapeutic marker in NSCLC in the future.

Methylenetetrahydrofolate reductase C677T polymorphism in patients with lung cancer in a Korean population.

BACKGROUND: This study was designed to investigate an association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and the risk of lung cancer in a Korean population. METHODS: We conducted a large-scale, case-control study involving 3938 patients with newly diagnosed lung cancer and 1700 healthy controls. Genotyping was performed with peripheral blood DNA for MTHFR C677T polymorphisms. Statistical significance was estimated by logistic regression analysis. RESULTS: The MTHFR C677T frequencies of CC, CT, and TT genotypes were 34.5%, 48.5%, and 17% among lung cancer patients, and 31.8%, 50.7%, and 17.5% in the controls, respectively. The MTHFR 677CT and TT genotype showed a weak protection against lung cancer compared with the homozygous CC genotype, although the results did not reach statistical significance. The age- and gender-adjusted odds ratio (OR) of overall lung cancer was 0.90 (95% confidence interval (CI), 0.77-1.04) for MTHFR 677 CT and 0.88 (95% CI, 0.71-1.07) for MTHFR 677TT. However, after stratification analysis by histological type, the MTHFR 677CT genotype showed a significantly decreased risk for squamous cell carcinoma (age- and gender-adjusted OR, 0.78; 95% CI, 0.64-0.96). The combination of 677 TT homozygous with 677 CT heterozygous also appeared to have a protection effect on the risk of squamous cell carcinoma. We observed no significant interaction between the MTHFR C677T polymorphism and age and gender or smoking habit. CONCLUSIONS: This is the first reported study focusing on the association between MTHFR C677T polymorphisms and the risk of lung cancer in a Korean population. The T allele was found to provide a weak protective association with lung squamous cell carcinoma.

[Correlation Analysis of Serum LDH Concentration before and after Operation and Prognosis of Large Cell Neuroendocrine Lung Cancer Patients].

BACKGROUND: Studies have shown that elevated serum lactate dehydrogenase (LDH) concentration can lead to poor prognosis in patients with small cell lung cancer and lung adenocarcinoma, but its relationship with the prognosis of patients with lung large-cell neuroendocrine carcinoma (L-LCNEC) is not clear. This study aims to explore the influence of L-LCNEC preoperative serum LDH concentration and postoperative LDH concentration change trend on the disease-free survival (DFS) of patients after surgery, so as to judge the clinical prognosis of L-LCNEC provides new ideas. METHODS: Collected the clinical data. The receiver operating characteristic (ROC) curve was used to determine the optimal cut-off value, while the Kaplan-Meier and Cox proportional hazard model were used to analyze data. RESULTS: DFS was shortened in patients with high serum LDH concentration before operation and increased LDH concentration after operation (P<0.001, P<0.001). The preoperative LDH concentration and postoperative LDH concentration change trend were independent prognostic factors for patients (P<0.001, P=0.037). CONCLUSIONS: Preoperative LDH concentration and its postoperative concentration change trend in patients with L-LCNEC are independent prognostic factors for DFS of patients.

MMP1 drives tumor progression in large cell carcinoma of the lung through fibroblast senescence.

Large cell carcinoma (LCC) is a rare and aggressive lung cancer subtype with poor prognosis and no targeted therapies. Tumor-associated fibroblasts (TAFs) derived from LCC tumors exhibit premature senescence, and coculture of pulmonary fibroblasts with LCC cell lines selectively induces fibroblast senescence, which in turn drives LCC cell growth and invasion. Here we identify MMP1 as overexpressed specifically in LCC cell lines, and we show that expression of MMP1 by LCC cells is necessary for induction of fibroblast senescence and consequent tumor promotion in both cell culture and mouse models. We also show that MMP1, in combination with TGF-ß1, is sufficient to induce fibroblast senescence and consequent LCC promotion. Furthermore, we implicate PAR-1 and oxidative stress in MMP1/TGF-ß1-induced TAF senescence. Our results establish an entirely new role for MMP1 in cancer, and support a novel therapeutic strategy in LCC based on targeting senescent TAFs.

Identification of thymidylate synthase as a potential therapeutic target for lung cancer.

BACKGROUND: Thymidylate synthase (TS), a key enzyme in the de novo synthesis of thymidine, is an important chemotherapeutic target for malignant tumours including lung cancer. Although inhibition of TS has an antiproliferative effect in cancer cells, the precise mechanism of this effect has remained unclear. METHODS: We examined the effects of TS inhibition with an RNA interference-based approach. The effect of TS depletion on the growth of lung cancer cells was examined using colorimetric assay and flow cytometry. RESULTS: Measurement of the enzymatic activity of TS in 30 human lung cancer cell lines revealed that such activity differs among tumour histotypes. Almost complete elimination of TS activity by RNA interference resulted in inhibition of cell proliferation in all tested cell lines, suggestive of a pivotal role for TS in cell proliferation independent of the original level of enzyme activity. The antiproliferative effect of TS depletion was accompanied by arrest of cells in S phase of the cell cycle and the induction of caspase-dependent apoptosis as well as by changes in the expression levels of cyclin E and c-Myc. Moreover, TS depletion induced downregulation of the antiapoptotic protein X-linked inhibitor of apoptosis (XIAP), and it seemed to activate the mitochondrial pathway of apoptosis. CONCLUSION: Our data provide insight into the biological relevance of TS as well as a basis for clinical development of TS-targeted therapy for lung cancer.

High-grade neuroendocrine carcinoma of the lung shows increased thymidylate synthase expression compared to other histotypes.

BACKGROUND: Thymidylate synthase (TS) expression has been reported in various tumors, including non-small-cell lung carcinoma (NSCLC), but not in high-grade neuroendocrine (HGNE) carcinoma of the lung. METHODS: We measured TS expression in surgically resected pulmonary tumors, comparing HGNE carcinomas of the lung (13 large-cell neuroendocrine carcinomas, 8 small-cell lung carcinomas) with squamous cell carcinoma and adenocarcinoma of the lung using laser-capture microdissection for tissue isolation, real-time polymerase chain reaction (PCR), and immunohistochemistry. We also measured TS mRNA expression in small-cell lung carcinoma (SCLC) and NSCLC cell lines using real-time PCR. RESULTS: At both mRNA and protein levels, TS expression was significantly higher in squamous cell carcinoma compared to adenocarcinoma. Moreover, TS expression was significantly higher in HGNE carcinomas of the lung compared to squamous cell carcinoma. A significant correlation was found between mRNA and protein expression. TS mRNA expression in SCLC cell lines was significantly higher than in NSCLC cell lines. CONCLUSIONS: TS expression was higher in HGNE carcinomas of the lung than in squamous cell carcinoma, which was higher than in adenocarcinoma. This information may be useful in predicting the effects of TS-inhibiting agents in patients with NSCLC and HGNE carcinomas of the lung.

Cytosolic phospholipase A2: targeting cancer through the tumor vasculature.

PURPOSE: In vascular endothelial cells, low doses of ionizing radiation trigger the immediate activation of cytosolic phospholipase A2 (cPLA2). This event initiates prosurvival signaling that could be responsible for radioresistance of tumor vasculature. Thus, the development of radiosensitizers targeting these survival pathways may enhance tumor response to radiation therapy. Arachidonyltrifluoromethyl Ketone (AACOCF3), a specific cPLA2 inhibitor, was studied as a potential radiosensitizer. EXPERIMENTAL DESIGN: Vascular endothelial cells (3B11 and MPMEC) and lung tumor cells (LLC and H460) were treated with 1 micromol/L AACOCF3 for 30 minutes prior to irradiation. Treatment response was evaluated by clonogenic survival, activation of extracellular signal-regulated kinase 1/2 (ERK1/2), tubule formation, and migration assays. For in vivo experiments, mice with LLC or H460 tumors in the hind limbs were treated for 5 consecutive days with 10 mg/kg AACOCF3 administered daily 30 minutes prior to irradiation. Treatment response was assessed by tumor growth delay, Power Doppler Sonography, and immunohistochemistry. RESULTS: In cell culture experiments, inhibition of cPLA2 with AACOCF3 prevented radiation-induced activation of ERK1/2 and decreased clonogenic survival of irradiated vascular endothelial cells but not the lung tumor cells. Treatment with AACOCF3 also attenuated tubule formation and migration in irradiated vascular endothelial cells. In both tumor mouse models, treatment with AACOCF3 prior to irradiation significantly suppressed tumor growth and decreased overall tumor blood flow and vascularity. Increased apoptosis in both tumor cells and tumor vascular endothelium was determined as a possible mechanism of the observed effect. CONCLUSION: These findings identify cPLA2 as a novel molecular target for tumor sensitization to radiation therapy through the tumor vasculature.

Somatic alterations of the serine/threonine kinase LKB1 gene in squamous cell (SCC) and large cell (LCC) lung carcinoma.

Somatic LKB1 serine/threonine kinase alterations are rare in sporadic cancers, with the exception lung adenocarcinoma, but no mutations in squamous cell or large cell primary carcinoma were discovered. We screened the LKB1 gene in 129 primary nonsmall cell lung carcinomas, adjacent healthy lung tissue, and control blood samples. Forty-five percent of nonsmall cell lung tumors harbored either intron or exon alterations. We identified R86G, F354L, Y272Y and three polymorphisms: 290+36G/T, 386+156G/T, and 862+145C/T (novel). R86G (novel) and F354L mutations were found in six squamous cell carcinomas and three large cell cancer carcinomas, but not in the adjacent healthy tissue or controls samples. The F354L mutation was found in advanced squamous cell carcinomas with elevated COX-2 expression, rare P53, and no K-RAS mutation. Results indicate that the LKB1 gene is changed in a certain proportion of nonsmall cell lung tumors, predominately in advanced squamous lung carcinoma. Inactivation of the gene takes place via the C-terminal domain and could be related to mechanisms influencing tumor initiation, differentiation, and metastasis.

Increased human telomerase reverse transcriptase (hTERT) mRNA expression but not telomerase activity is related to survival in curatively resected non-small cell lung cancer.

BACKGROUND: The purpose of this study was to evaluate the significance of human telomerase reverse transcriptase (hTERT) mRNA expression and telomerase activity as prognostic markers in non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: In a series of 69 curatively resected NSCLC specimens, telomerase activity was analyzed with the telomeric repeat amplification protocol (TRAP) assay and expression of hTERT mRNA by quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Partitioning of gene expression levels and protein activities to construct prognostic groups was attempted. RESULTS: Human hTERT mRNA transcripts were detected in 62 (89.9%) cases of NSCLC. Seven (10.1%) tumors were completely negative for hTERT expression. Dichotomized hTERT levels (<0.42 versus > or =0.42) were associated with prognosis and Kaplan-Meier survival curves demonstrated a significant difference (log rank: p<0.01) with 5-year survival rates of 44.3% (+/-7.1%) for low as compared to 80% (+/-8.9%) for high hTERT mRNA expression. Low hTERT expression was also significantly associated with squamous cell histology (p<0.03). Telomerase activity was not associated with survival, stage, pT and pN categories, histological type or grading. Comparison of hTERT mRNA expression and telomerase activity was possible in 66 patients and showed a significant difference (p<0.0001) by Wilcoxon rank test. CONCLUSION: This is the first study which demonstrates that high hTERT mRNA expression is associated with improved 5-year survival rates. Expression patterns are distinct among histopathological subtypes of NSCLC and telomerase activity (TRAP) is significantly higher than hTERT mRNA expression.

The expression of COX-2, hTERT, MDM2, LATS2 and S100A2 in different types of non-small cell lung cancer (NSCLC).

Several studies have reported different expression levels of certain genes in NSCLC, mostly related to the stage and advancement of the tumours. We investigated 65 stage I-III NSCLC tumours: 32 adenocarcinomas (ADC), 26 squamous cell carcinomas (SCC) and 7 large cell carcinomas (LCC). Using the real-time reverse transcription polymerase chain reaction (RT-PCR), we analysed the expression of the COX-2, hTERT, MDM2, LATS2 and S100A2 genes and researched the relationships between the NSCLC types and the differences in expression levels. The differences in the expression levels of the LATS2, S100A2 and hTERT genes in different types of NSCLC are significant. hTERT and COX-2 were over-expressed and LATS2 under-expressed in all NSCLC. We also detected significant relative differences in the expression of LATS2 and MDM2, hTERT and MDM2 in different types of NSCLC. There was a significant difference in the average expression levels in S100A2 for ADC and SCC. Our study shows differences in the expression patterns within the NSCLC group, which may mimic the expression of the individual NSCLC type, and also new relationships in the expression levels for different NSCLC types.

Expression of glutathione S-transferase pi and glutathione synthase correlates with survival in early stage non-small cell carcinomas of the lung.

The glutathione S-transferase (GST) family of genes encode for detoxification enzymes that protect against reactive oxygen species and influence host susceptibility to carcinogens, including tobacco smoke. It has not been determined whether isoenzyme GST-pi or glutathione synthase (GSH2) expression by tumor cells bears a relationship to survival. A total of 201 non-small cell lung cancers (NSCLC) with long-term follow-up were immunostained with antibodies to GST-pi and GSH2 using standard immunostaining techniques. Results were graded semiquantitatively using a scale of 0 to 3 (0 < or = 10%; 1 = 10%-50%; 2 = 51%-80%; 3 > or = 80%) for both nuclear and cytoplasmic staining. Results were correlated with patient survival using Kaplan-Meier analysis. Nuclear staining with GST-pi in greater than 10% of the cells was closely associated with decreased survival (P = .02) in stage I and II squamous cell carcinomas (n = 40). Cytoplasmic staining showed a similar trend that did not reach statistical significance. No significant correlation between GST-pi staining and survival was determined for other histologic types of NSCLC. Cytoplasmic GSH2 staining in greater than 80% of tumor cells was associated with a trend toward improved survival for stage I adenocarcinoma (P = .08) but did not show a relationship to survival for other histologic types of NSCLC. GST-pi expression predicts prognosis in stage I and II squamous cell lung carcinoma, and GSH2 expression may indicate better survival in early stage adenocarcinoma of the lung. Manipulation of GST-pi and GSH2 may be a potential basis for treatment of some NSCLC.

CYP2A6 overexpression in human lung cancers correlates with a high malignant status.

CYP2A6 is a major phase I enzyme metabolizing tobacco-specific nitrosamines, implicated as risk factors for lung cancer. In this study, immunohistochemistry and in situ hybridization (ISH) for CYP2A6 with human lung cancer tissues (n=31) obtained by surgical resection showed significantly higher immunoreactivity in the cases with lymph node metastasis. The adenocarcinoma cases (n=23) with lymph node metastasis or large tumor size showed a high immunoreactivity for CYP2A6. The squamous cell carcinoma cases (n=6) with large tumor size showed a tendency for low CYP2A6 immunoreactivity. ISH for CYP2A6 revealed mRNA expression in both adenocarcinoma and squamous cell carcinoma cells. The data suggest that CYP2A6 could have an important role in the development and proliferation of lung carcinomas. With adenocarcinomas, CYP2A6 could be a target candidate for therapeutic and chemopreventive intervention.

Identification of alpha-enolase as an autoantigen in lung cancer: its overexpression is associated with clinical outcomes.

PURPOSE: Although existence of humoral immunity has been previously shown in malignant pleural effusions, only a limited number of immunogenic tumor-associated antigens (TAA) have been identified and associated with lung cancer. In this study, we intended to identify more TAAs in pleural effusion-derived tumor cells. EXPERIMENTAL DESIGN: Using morphologically normal lung tissues as a control lysate in Western blotting analyses, 54 tumor samples were screened with autologous effusion antibodies. Biochemical purification and mass spectrometric identification of TAAs were done using established effusion tumor cell lines as antigen sources. We identified a p48 antigen as alpha-enolase (ENO1). Semiquantitative immunohistochemistry was used to evaluate expression status of ENO1 in the tissue samples of 80 patients with non-small cell lung cancer (NSCLC) and then correlated with clinical variables. RESULTS: Using ENO1-specifc antiserum, up-regulation of ENO1 expression in effusion tumor cells from 11 of 17 patients was clearly observed compared with human normal lung primary epithelial and non-cancer-associated effusion cells. Immunohistochemical studies consistently showed high level of ENO1 expression in all the tumors we have examined thus far. Log-rank and Cox's analyses of ENO1 expression status revealed that its expression level in primary tumors was a key factor contributing to overall- and progression-free survivals of patients (P < 0.05). The same result was also obtained in the early stage of NSCLC patients, showing that tumors expressing relatively higher ENO1 level were tightly correlated with poorer survival outcomes. CONCLUSIONS: Our data strongly support a prognostic role of ENO1 in determining tumor malignancy of patients with NSCLC.

Somatic mutations of the protein kinase gene family in human lung cancer.

Protein kinases are frequently mutated in human cancer and inhibitors of mutant protein kinases have proven to be effective anticancer drugs. We screened the coding sequences of 518 protein kinases (approximately 1.3 Mb of DNA per sample) for somatic mutations in 26 primary lung neoplasms and seven lung cancer cell lines. One hundred eighty-eight somatic mutations were detected in 141 genes. Of these, 35 were synonymous (silent) changes. This result indicates that most of the 188 mutations were "passenger" mutations that are not causally implicated in oncogenesis. However, an excess of approximately 40 nonsynonymous substitutions compared with that expected by chance (P = 0.07) suggests that some nonsynonymous mutations have been selected and are contributing to oncogenesis. There was considerable variation between individual lung cancers in the number of mutations observed and no mutations were found in lung carcinoids. The mutational spectra of most lung cancers were characterized by a high proportion of C:G > A:T transversions, compatible with the mutagenic effects of tobacco carcinogens. However, one neuroendocrine cancer cell line had a distinctive mutational spectrum reminiscent of UV-induced DNA damage. The results suggest that several mutated protein kinases may be contributing to lung cancer development, but that mutations in each one are infrequent.

Role of chemotherapy and the receptor tyrosine kinases KIT, PDGFRalpha, PDGFRbeta, and Met in large-cell neuroendocrine carcinoma of the lung.

PURPOSE: Pulmonary large-cell neuroendocrine carcinoma (LCNEC) is a relatively uncommon, high-grade neuroendocrine tumor sharing several features with small-cell lung carcinoma (SCLC) but currently considered as a variant of non-SCLC and accordingly treated with poor results. Little is known about the optimal therapy of LCNEC and the possible therapeutic molecular targets. PATIENTS AND METHODS: We reviewed 83 patients with pure pulmonary LCNEC to investigate their clinicopathologic features, therapeutic strategy, and immunohistochemical expression and the mutational status of the receptor tyrosine kinases (RTKs) KIT, PDGFRalpha, PDGFRbeta, and Met. RESULTS: LCNEC histology predicted a dismal outcome (overall median survival, 17 months) even in stage I patients (5-year survival rate, 33%). LCNEC strongly expressed RTKs (KIT in 62.7% of patients, PDGFRalpha in 60.2%, PDGFRbeta in 81.9%, and Met in 47%), but no mutations were detected in the exons encoding for the relevant juxtamembrane domains. Tumor stage and size (> or = 3 cm) and Met expression were significantly correlated with survival. At univariate and multivariate analysis, SCLC-based chemotherapy (platinum-etoposide) was the most important variable correlating with survival, both in the adjuvant and metastatic settings (P < .0001). CONCLUSION: Pulmonary LCNEC represents an aggressive tumor requiring multimodal treatment even for resectable stage I disease, and LCNEC seems to respond to adjuvant platinum-etoposide-based chemotherapy. Patients who received this therapy had the best survival rate. Despite our failure in finding mutational events in the tested RTKs, the strong expression of KIT, PDGFRalpha, PDGFRbeta, and Met in tumor cells suggests an important role of these RTKs in LCNEC, and these RTKs seem to be attractive therapeutic targets.

High telomerase activity in primary lung cancers: association with increased cell proliferation rates and advanced pathologic stage.

BACKGROUND: Telomerase enzyme activity is not detected in most normal cells, a phenomenon believed to be associated with limitations on cellular proliferation. Since this activity is detected in nearly all human tumors, including non-small-cell lung cancers, it has been suggested that telomerase activation may be coupled to acquisition of the malignant phenotype. In this study, we determined whether telomerase activity was associated with tumor pathologic stage, tumor cell proliferation rates, and clinical outcome in a cohort of patients with resected non-small-cell lung cancer for whom long-term follow-up was available. METHODS: Primary tumor specimens from 99 patients treated with surgery alone and six patients treated with surgery after chemotherapy were analyzed. Telomerase activity was measured by means of a modified Telomeric Repeat Amplification Protocol (TRAP) assay. Southern blot analysis of terminal restriction fragments was used to evaluate telomere length. Immunohistochemical analysis of Ki-67, a proliferation-associated nuclear antigen, was used to assess tumor cell proliferation. RESULTS: Telomerase activity was detected in 84 of the 99 tumors treated with surgery alone; this activity was not detected in specimens of adjacent, benign lung tissue. Telomerase was detected in only three of six tumors resected after chemotherapy. For the surgery-alone group, statistically significant positive associations were found between the level of telomerase activity and tumor stage, lymph node metastasis, pathologic TNM (tumor-node-metastasis) stage, and Ki-67 immunostaining; a statistically significant inverse association was found between telomerase activity and patient age. No statistically significant differences in telomere length were found in relation telomerase activity or pathologic stage. Telomerase activity was not found to be associated with clinical outcome in a multivariate Cox proportional hazards analysis adjusted for tumor stage and lymph node status. CONCLUSIONS: High telomerase activity is detected frequently in primary non-small-cell lung cancers that exhibit high tumor cell proliferation rates and advanced pathologic stage.

MicroRNAs associated with increased AKT gene number in human lung carcinoma.

MicroRNA (miRNA) expression profiles were examined in 3 groups of lung carcinomas that had been stratified by increases in AKT1 or AKT2 gene number. Microarray analysis using 2000 probes revealed 87 miRNAs that were up-regulated and 32 down-regulated miRNAs in carcinomas harboring amplification or high-level polysomy of the AKT1 (AKT1+), as well as 123 up-regulated and 83 down-regulated miRNAs in those of the AKT2 genes (AKT2+), in comparison with carcinomas harboring disomy of both (AKTd/d). In total, 182 miRNAs were up-regulated in AKT1+ or AKT2+, compared with AKTd/d. Among these, 28 miRNAs were up-regulated in both the AKT1+ and AKT2+ groups, with a log2 ratio between 1.02 and 3.71 relative to AKTd/d group, including all miR-200 family members. Quantitative real-time polymerase chain reaction showed that carcinomas exhibiting lymph vessel invasion had significantly lower expression of miR-200a (P=.0230) and miR-200b (P=.0168), regardless of the status of the AKT genes. Moreover, a detailed statistical analysis revealed that, in adenocarcinoma and in the early stage of carcinomas (pathologic stage I/II), expression of miR-200a was higher in the AKT2+ group compared with the AKT1+ group, and these differences were statistically significant (P=.0334 and P=.0239, respectively). However, the expression of miR-200a was not significantly correlated with the expression of its target, the zinc finger E-box-binding homeobox 1 (ZEB1; P=.3801) or E-cadherin (P=.2840), a marker of the epithelial-mesenchymal transition. These results suggest that AKT2 can regulate miR-200a in a histology- or stage-specific manner and that this regulation is independent of subsequent involvement of miR-200a in epithelial-mesenchymal transition.