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Rationale: As computed tomography (CT) screening for lung cancer becomes more widespread, volumetric analyses, including doubling times, of CT-screen detected lung nodules and lung cancers may provide useful information in the follow-up and management of CT-detected lung nodules and cancers.Objectives: To analyze doubling times in CT screen detected lung cancers and compare prevalent and nonprevalent cancers and different cell types on non small cell lung cancer.Methods: We performed volumetric and doubling time analysis on 63 non–small cell lung cancers detected as part of the Pittsburgh Lung Screening Study using a commercially available VITREA 2 workstation and VITREA VITAL nodule segmentation software.Measurements and Main Results: Doubling times (DT) were divided into three groups: rapid (DT<183 d), typical (DT 183–365 d), and slow (DT>365 d). Adenocarcinoma/bronchioloalveolar carcinoma comprised 86.7% of the slow DT group compared with 20% of the rapid DT group. Conversely, squamous cell cancer comprised 60% of the rapid DT group compared with 3.3% of the slow DT group. Twenty-eight of 42 (67%) prevalent and 2 of 21 (10%) nonprevalent cancers were in the slow DT group (P<0.0001; Fisher's exact test). Twenty-four of 32 (75%) prevalent and 1 of 11 (9%) nonprevalent adenocarcinomas were in the slow DT group (P<0.0002; Fisher's exact test).Conclusions: Volumetric analysis of CT-detected lung cancers is particularly useful in AC/BAC. Prevalent cancers have a significantly slower DT than nonprevalent cancers and a higher percentage of adenocarcinoma/bronchioloalveolar carcinoma. These results should affect the management of indeterminant lung nodules detected on screening CT scans. [ABSTRACT FROM AUTHOR]

Rationale: The role of computed tomography (CT) screening for lung cancer is controversial, currently under study, and not yet fully elucidated.Objectives: To report findings from initial and 1-year repeat screening low-radiation-dose CT of the chest and 3-year outcomes for 50- to 79-year-old current and ex-smokers in the Pittsburgh Lung Screening Study (PLuSS).Methods: Notified of findings on screening CT, subjects received diagnostic advice from both study and personal physicians. Tracking subjects for up to three years since initial screening, we obtained medical records to document diagnostic procedures, lung cancer diagnoses, and deaths.Measurements and Main Results: 3,642 and 3,423 subjects had initial and repeat screening. A total of 1,477 (40.6% of 3,624) were told about noncalcified lung nodules on the initial screening and, before repeat screening, 821 (55.6% of 1,477, 22.5% of 3,642) obtained one or more subsequent diagnostic imaging studies (CT, positron emission tomography [PET], or PET-CT). Tracking identified 80 subjects with lung cancer, including 53 subjects with tumor seen at initial screening. In all, 36 subjects (1.0% of the 3,642 screened), referred for abnormalities on either the initial or repeat screening, had a major thoracic surgical procedure (thoracotomy, video-assisted thoracoscopic surgery [VATS], median sternotomy, or mediastinoscopy) leading to a noncancer final diagnosis. Out of 82 subjects with thoracotomy or VATS to exclude malignancy in a lung nodule, 28 (34.1%) received a noncancer final diagnosis. Forty of 69 (58%) subjects with non-small cell lung cancer had stage I disease at diagnosis.Conclusions: Though leading to the discovery of early stage lung cancer, CT screening also led to many diagnostic follow-up procedures, including major thoracic surgical procedures with noncancer outcomes. [ABSTRACT FROM AUTHOR]

Rationale: To study the relationship between emphysema and/or airflow obstruction and lung cancer in a high-risk population.Objective: We studied lung cancer related to radiographic emphysema and spirometric airflow obstruction in tobacco-exposed persons who were screened for lung cancer using chest computed tomography (CT).Methods: Subjects completed questionnaires, spirometry, and low-dose helical chest CT. CT scans were scored for emphysema based on National Emphysema Treatment Trial criteria. Multiple logistic regressions estimated the independent associations between various factors, including radiographic emphysema and airflow obstruction, and subsequent lung cancer diagnosis.Measurements and Main Results: Among 3,638 subjects, 57.5, 18.8, 14.6, and 9.1% had no, trace, mild, and moderate-severe emphysema, and 57.3, 13.6, 22.8, and 6.4% had no, mild (Global Initiative for Chronic Obstructive Lung Disease [GOLD] I), moderate (GOLD II), and severe (GOLD III-IV) airflow obstruction. Of 3,638 subjects, 99 (2.7%) received a lung cancer diagnosis. Adjusting for sex, age, years of cigarette smoking, and number of cigarettes smoked daily, logistic regression showed the expected lung cancer association with the presence of airflow obstruction (GOLD I-IV, odds ratio [OR], 2.09; 95% confidence interval [CI], 1.33-3.27). A second logistic regression showed lung cancer related to emphysema (OR, 3.56; 95% CI, 2.21-5.73). After additional adjustments for GOLD class, emphysema remained a strong and statistically significant factor related to lung cancer (OR, 3.14; 95% CI, 1.91-5.15).Conclusions: Emphysema on CT scan and airflow obstruction on spirometry are related to lung cancer in a high-risk population. Emphysema is independently related to lung cancer. Both radiographic emphysema and airflow obstruction should be considered when assessing lung cancer risk. [ABSTRACT FROM AUTHOR]

Altered expression of syndecan-2 (SDC2), a heparan sulfate proteoglycan, has been associated with diverse types of human cancers. However, the mechanisms by which SDC2 may contribute to the pathobiology of lung adenocarcinoma have not been previously explored. SDC2 levels were measured in human lung adenocarcinoma samples and lung cancer tissue microarrays using immunohistochemistry and real-time PCR. To understand the role of SDC2 in vitro , SDC2 was silenced or overexpressed in A549 lung adenocarcinoma cells. The invasive capacity of cells was assessed using Matrigel invasion assays and measuring matrix metalloproteinase (MMP) 9 expression. Finally, we assessed tumor growth and metastasis of SDC2-deficient A549 cells in a xenograft tumor model. SDC2 expression was upregulated in malignant epithelial cells and macrophages obtained from human lung adenocarcinomas. Silencing of SDC2 decreased MMP9 expression and attenuated the invasive capacity of A549 lung adenocarcinoma cells. The inhibitory effect of SDC2 silencing on MMP9 expression and cell invasion was reversed by overexpression of MMP9 and syntenin-1. SDC2 silencing attenuated NF-κB p65 subunit nuclear translocation and its binding to the MMP9 promoter, which were restored by overexpression of syntenin-1. SDC2 silencing in vivo reduced tumor mass volume and metastasis. These findings suggest that SDC2 plays an important role in the invasive properties of lung adenocarcinoma cells and that its effects are mediated by syntenin-1. Thus, inhibiting SDC2 expression or activity could serve as a potential therapeutic target to treat lung adenocarcinoma.

Rationale: Gene promoter hypermethylation detected in sputum assesses the extent of field cancerization and predicts lung cancer (LC) risk in ever-smokers. A rapid decline of FEV 1 is a major driver for development of airway obstruction., Objectives: To assess the effects of methylation of 12 genes on FEV 1 decline and of FEV 1 decline on subsequent LC incidence using two independent, longitudinal cohorts (i.e., LSC [Lovelace Smokers Cohort] and PLuSS [Pittsburgh Lung Screening Study])., Methods: Gene methylation was measured in sputum using two-stage nested methylation-specific PCR. The linear mixed effects model was used to assess the effects of studied variables on FEV 1 decline., Measurements and Main Results: A dose-dependent relationship between number of genes methylated and FEV 1 decline was identified, with smokers with three or more methylated genes having 27.8% and 10.3% faster FEV 1 decline than smokers with zero to two methylated genes in the LSC and PLuSS cohort, respectively (all P < 0.01). High methylation in sputum was associated with a shorter latency for LC incidence (log-rank P = 0.0048) and worse all-cause mortality (log-rank P < 0.0001). Smokers with subsequent LC incidence had a more rapid annual decline of FEV 1 (by 5.2 ml, P = 0.038) than smoker control subjects., Conclusions: Gene methylation detected in sputum predicted FEV 1 decline, LC incidence, and all-cause mortality in smokers. Rapid FEV 1 decline may be a risk factor for LC incidence in smokers, which may explain a greater prevalence of airway obstruction seen in patients with LC.

Rationale: Vascular endothelial growth factor down-regulates microRNA-1 (miR-1) in the lung endothelium, and endothelial cells play a critical role in tumor progression and angiogenesis., Objectives: To examine the clinical significance of miR-1 in non-small cell lung cancer (NSCLC) and its specific role in tumor endothelium., Methods: miR-1 levels were measured by Taqman assay. Endothelial cells were isolated by magnetic sorting. We used vascular endothelial cadherin promoter to create a vascular-specific miR-1 lentiviral vector and an inducible transgenic mouse. KRAS G12D mut /Trp 53-/- (KP) mice, lung-specific vascular endothelial growth factor transgenic mice, Lewis lung carcinoma xenografts, and primary endothelial cells were used to test the effects of miR-1., Measurements and Main Results: In two cohorts of patients with NSCLC, miR-1 levels were lower in tumors than the cancer-free tissue. Tumor miR-1 levels correlated with the overall survival of patients with NSCLC. miR-1 levels were also lower in endothelial cells isolated from NSCLC tumors and tumor-bearing lungs of KP mouse model. We examined the significance of lower miR-1 levels by testing the effects of vascular-specific miR-1 overexpression. Vector-mediated delivery or transgenic overexpression of miR-1 in endothelial cells decreased tumor burden in KP mice, reduced the growth and vascularity of Lewis lung carcinoma xenografts, and decreased tracheal angiogenesis in vascular endothelial growth factor transgenic mice. In endothelial cells, miR-1 level was regulated through phosphoinositide 3-kinase and specifically controlled proliferation, de novo DNA synthesis, and ERK1/2 activation. Myeloproliferative leukemia oncogene was targeted by miR-1 in the lung endothelium and regulated tumor growth and angiogenesis., Conclusions: Endothelial miR-1 is down-regulated in NSCLC tumors and controls tumor progression and angiogenesis.

Rationale: Lung cancer is the leading cause of cancer death in both men and women in the United States and worldwide. Matrix metalloproteinases (MMPs) have been implicated in the development and progression of lung cancer, but their role in the molecular pathogenesis of lung cancer remains unclear. We have found that MMP19, a relatively novel member of the MMP family, is overexpressed in lung tumors when compared with control subjects., Objectives: To test the hypothesis that MMP19 plays a significant role in the development and progression of non-small cell lung cancer (NSCLC)., Methods: We have analyzed lung cancer gene expression data, immunostained lung tumors for MMP19, and performed in vitro assays to test the effects of MMP19 in NSCLC cells., Measurements and Main Results: We found that MMP19 gene and protein expression is increased in lung cancer tumors compared with adjacent and histologically normal lung tissues. In three independent datasets, increased MMP19 gene expression conferred a poorer prognosis in NSCLC. In vitro, we found that overexpression of MMP19 promotes epithelial-mesenchymal transition, migration, and invasiveness in multiple NSCLC cell lines. Overexpression of MMP19 with a mutation at the catalytic site did not impair epithelial-mesenchymal transition or expression of prometastasis genes. We also found that miR-30 isoforms, a microRNA family predicted to target MMP19, is markedly down-regulated in human lung cancer and regulates MMP19 expression., Conclusions: Taken together, these findings suggest that MMP19 is associated with the development and progression of NSCLC and may be a potential biomarker of disease severity and outcome.

Significant progress has been made toward identifying growth factors that display autocrine or paracrine effects on the growth of lung cancer cells. Determining the in vivo relevance of specific growth factors on lung tumor formation, however, has not often been demonstrated in laboratory models. Although hepatocyte growth factor (HGF) has been shown to have mitogenic and motogenic effects on human lung cancer cells in vitro, and to have prognostic importance in patients with lung cancer, the effects of HGF on tumor behavior in vivo remain unknown. We therefore developed an airway tumor xenograft model that allowed us to test the hypothesis that HGF promotes human non-small cell lung cancer (NSCLC) growth in vivo. Human airway tumor xenografts were created in Severe Combined Immunodeficient mice by injecting human lung adenocarcinoma cells into human bronchial segments. After determining the optimal times for tumor-cell injection and the time course of tumor growth, we evaluated the effects of HGF on tumor growth by injecting recombinant HGF, or saline as a control, into the lumen of tumor xenografts for 10 consecutive days. Histologic evaluation 2 to 3 wk later revealed that the HGF-injected xenografts had a significantly greater tumor volume and more tumor cells were located in the submucosal space than were found in the saline-injected xenografts. These data demonstrate the usefulness of this novel in vivo model to study NSCLC, and show that HGF promotes both the growth and invasion of human lung cancer in vivo.

Bombesin-like peptides (BLPs) are important regulators of lung development and may also act as autocrine growth factors in lung tumors. We have previously demonstrated expression of mRNA for the three BLP receptor subtypes (neuromedin B [NMB]) receptor, gastrin-releasing peptide [GRP] receptor, and bombesin receptor subtype 3 [BRS-3]) in human non-small cell lung carcinoma (NSCLC) cell lines and bronchial biopsies using the reverse transcription-polymerase chain reaction (RT-PCR; DeMichele, et al. Am. J. Respir. Cell Mol. Biol. 1994; 11:66-74). We have also previously found that growth responses to BLPs could be elicited in some, but not all, cultures of human bronchial epithelial (HBE) cells (Siegfried, et al. Anat. Rec. 1993; 236:241-247). In this report, we utilized RT-PCR to demonstrate mRNA expression of BLP receptor subtypes in cultured HBE cells and also assessed the response of these cultures to BLPs in proliferation assays. The pattern of mRNA expression was correlated with proliferative response, and the results were also analyzed in relation to smoking history and pulmonary function of the subjects studied. Our results suggest that expression of mRNA for the GRP receptor is associated with a long smoking history (> 25 pack-years [PY], p = 0.02). This association was related to past tobacco exposure, regardless of whether the subjects were still active smokers at the time of tissue procurement. Responsiveness to GRP and NMB in proliferation assays was also found only in those HBE cultures with expression of mRNA for at least one of the known receptors for BLPs, and there was a significant association between expression of mRNA for the GRP receptor and proliferative response to both GRP and NMB (p = 0.048). HBE cultures from subjects with a greater than 25 PY smoking history were also more likely to respond to BLPs in the proliferation assays than cells from subjects with less than a 25 PY history (10 of 16 versus 1 of 7, p = 0.06). Cultures of HBE cells from four of the five subjects with severe obstructive lung disease gave a positive response to GRP and NMB in proliferation assays, compared to five of fifteen without severe obstructive lung disease, but this difference was not significant (p = 0.13). These results suggest there is an increased likelihood of expression of the GRP receptor mRNA in the respiratory epithelium of some individuals with a history of prolonged tobacco exposure, and that expression of the GRP receptor mRNA is accompanied by responsiveness to the mitogenic effects of BLPs. These effects appear to persist after smoking cessation.

Gastrin-releasing peptide (GRP), the mammalian form of the amphibian peptide bombesin, may act as a growth-regulatory peptide in the lung. Cultured human bronchial epithelial (HBE) cells have previously been found to proliferate in response to GRP or bombesin. Three receptors have been identified for bombesin and its analogs, namely gastrin-releasing peptide receptor (GRPR), neuromedin B receptor (NMBR), and bombesin receptor subtype 3 (BRS-3). The human genes for these receptors have been cloned and sequenced. We used the polymerase chain reaction to detect transcripts for these three receptor subtypes in HBE cells cultured from bronchial mucosal biopsies. Primers specific for each receptor subtype were used to amplify DNA fragments from reverse-transcribed mRNA isolated from these cultures. An amplified fragment was detected for GRPR in seven of nine cases, for NMBR in six of 10 cases, and the BRS-3 in three of nine cases. We have also amplified message for NMBR in five of five fresh bronchial biopsies, but message for GRPR could not be detected. In preliminary evaluation of two biopsies, there was also no evidence of BRS-3 expression. Additionally, we have detected transcripts for GRPR and NMBR in four of seven and seven of seven cases, respectively, of cultured non-small cell lung carcinomas (NSCLC). BRS-3 expression was seen in one of seven carcinomas in culture. Identity of the amplified fragments was confirmed by restriction enzyme digestion and Southern blotting. Furthermore, GRP induced expression of the early-response gene, c-jun, in an HBE cell culture and an NSCLC cell line. GRP also promoted colony formation in the NSCLC cells.(ABSTRACT TRUNCATED AT 250 WORDS)