Takuya Samukawa

Downregulation of the microRNA-1/133a cluster enhances cancer cell migration and invasion in lung-squamous cell carcinoma via regulation of Coronin1C

Lung cancer is clearly the primary cause of cancer-related deaths worldwide. Recent molecular-targeted strategy has contributed to improvement of the curative effect of adenocarcinoma of the lung. However, such current treatment has not been developed for squamous cell carcinoma (SCC) of the disease. The new genome-wide RNA analysis of lung-SCC may provide new avenues for research and the development of the disease. Our recent microRNA (miRNA) expression signatures of lung-SCC revealed that clustered miRNAs miR-1/133a were significantly reduced in cancer tissues. Here, we found that restoration of both mature miR-1 and miR-133a significantly inhibited cancer cell proliferation, migration and invasion. Coronin-1C (CORO1C) was a common target gene of the miR-1/133a cluster, as shown by the genome-wide gene expression analysis and the luciferase reporter assay. Silencing of CORO1C gene expression inhibited cancer cell proliferation, migration and invasion. Furthermore, CORO1C-regulated molecular pathways were categorized by using si-CORO1C transfectants. Further analysis of novel cancer signaling pathways modulated by the tumor-suppressive cluster miR-1/133a will provide insights into the molecular mechanisms of lung-SCC oncogenesis and metastasis.

EGFR mutations and human papillomavirus in lung cancer

Our previous study reported a frequent detection of human papillomavirus (HPV) genome in primary lung adenocarcinomas of the recurrent patients who were responsive to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor, suggesting that HPV presence in lung cancer may be related to a genetic background related to EGFR mutations. The present study examined the association between the HPV presence and mutations in exons 19 and 21 of EGFR gene in Japanese lung cancer patients. Thirteen (31%) out of 42 cases had EGFR mutations. Although these mutations were tended to be observed in females, non-smokers, or adenocarcinomas, there was no statistically significant associations. HPV DNA was found in 7/42 (17%) lung tumors. The frequency of HPV presence did not differ in histological types. The presence of HPV DNA was significantly related to EGFR mutations (P=0.021), especially in adenocarcinomas of the lung (P=0.014). HPV-positive lung tumors accounted for 38% and 7% of those with and without EGFR mutations, respectively. Our results suggest that EGFR mutations are associated with HPV presence in Japanese patients with lung cancer.

The elevation of serum napsin A in idiopathic pulmonary fibrosis, compared with KL-6, surfactant protein-A and surfactant protein-D

BackgroundNapsin A, an aspartic protease, is mainly expressed in alveolar type-II cells and renal proximal tubules and is a putative immunohistochemical marker for pulmonary adenocarcinomas. This study sought to determine whether napsin A could be measured in the serum to evaluate its relationship to idiopathic pulmonary fibrosis (IPF) and determine whether renal dysfunction might affect serum napsin A levels.MethodsSerum levels of napsin A were measured in 20 patients with IPF, 34 patients with lung primary adenocarcinoma, 12 patients with kidney diseases, and 20 healthy volunteers. Surfactant protein (SP)-A, SP-D, and Krebs von den Lungen-6 (KL-6) levels in serum and pulmonary function tests were also evaluated in IPF patients.ResultsCirculating levels of napsin A were increased in patients with IPF, as compared with healthy controls, and they correlated with the severity of disease. Moreover, the serum napsin A levels were not elevated in patients with pulmonary adenocarcinoma or renal dysfunction. The distinguishing point between IPF and the controls was that the area under the receiver operating characteristic curve (ROC) of napsin A was larger than that of KL-6, SP-A, or SP-D.ConclusionThese findings suggest that serum napsin A may be a candidate biomarker for IPF.

Regulation of TPD52 by antitumor microRNA-218 suppresses cancer cell migration and invasion in lung squamous cell carcinoma

The development of targeted molecular therapies has greatly benefited patients with lung adenocarcinomas. In contrast, these treatments have had little benefit in the management of lung squamous cell carcinoma (lung SCC). Therefore, new treatment options based on current genomic approaches are needed for lung SCC. Aberrant microRNA (miRNA) expression has been shown to promote lung cancer development and aggressiveness. Downregulation of microRNA-218 (miR-218) was frequently observed in our miRNA expression signatures of cancers, and previous studies have shown an antitumor function of miR-218 in several types of cancers. However, the impact of miR-218 on lung SCC is still ambiguous. The present study investigated the antitumor roles of miR-218 in lung SCC to identify the target genes regulated by this miRNA. Ectopic expression of miR-218 greatly inhibited cancer cell migration and invasion in the lung SCC cell lines EBC-1 and SK-MES-1. Through a combination of in silico analysis and gene expression data searching, tumor protein D52 (TPD52) was selected as a putative target of miR-218 regulation. Moreover, direct binding of miR-218 to the 3′-UTR of TPD52 was observed by dual luciferase reporter assay. Overexpression of TPD52 was observed in lung SCC clinical specimens, and knockdown of TPD52 significantly suppressed cancer cell migration and invasion in lung SCC cell lines. Furthermore, the downstream pathways mediated by TPD52 involved critical regulators of genomic stability and mitotic checkpoint genes. Taken together, our data showed that downregulation of miR-218 enhances overexpression of TPD52 in lung SCC cells, promoting cancer cell aggressiveness. Identification of tumor-suppressive miRNA-mediated RNA networks of lung SCC will provide new insights into the potential mechanisms of the molecular pathogenesis of the disease.

Interstitial pneumonia induced by bleomycin treatment is exacerbated in Angptl2-deficient mice

Angiopoietin-like protein 2 (ANGPTL2) is a chronic inflammatory mediator that, when deregulated, is associated with various pathologies. However, little is known about its activity in lung. To assess a possible lung function, we generated a rabbit monoclonal antibody that specifically recognizes mouse ANGPTL2 and then evaluated protein expression in mouse lung tissue. We observed abundant ANGPTL2 expression in both alveolar epithelial type I and type II cells and in resident alveolar macrophages under normal conditions. To assess ANGPTL2 function, we compared lung phenotypes in Angptl2 knockout (KO) and wild-type mice but observed no overt changes. We then generated a bleomycin-induced interstitial pneumonia model using wild-type and Angptl2 KO mice. Bleomycin-treated wild-type mice showed specifically upregulated ANGPTL2 expression in areas of severe fibrosing interstitial pneumonia, while Angptl2 KO mice developed more severe lung fibrosis than did comparably treated wild-type mice. Lung fibrosis seen following bone marrow transplant was comparable in wild-type or Angptl2 KO mice treated with bleomycin, suggesting that Angptl2 loss in myeloid cells does not underlie fibrotic phenotypes. We conclude that Angptl2 deficiency in lung epithelial cells and resident alveolar macrophages causes severe lung fibrosis seen following bleomycin treatment, suggesting that ANGPTL2 derived from these cell types plays a protective role against fibrosis in lung.

Comparison of the COPD Population Screener and International Primary Care Airway Group questionnaires in a general Japanese population: the Hisayama study.

Background The incidence of chronic obstructive pulmonary disease (COPD) is increasing worldwide. In Japan and other countries, epidemiological studies have found that many patients with COPD are underdiagnosed and untreated, and thus, early detection and treatment of COPD has been emphasized. Screening questionnaires may have utility in the initial detection of COPD. Objective This study aimed to validate and compare the COPD Population Screener (COPD-PS) and the International Primary Care Airway Group (IPAG) questionnaires in a general Japanese population. Patients and methods Eligible subjects 40 years of age and older living in the town of Hisayama were solicited to participate in a health checkup in 2012. All subjects 40–79 years of age without physician-diagnosed asthma or lung resection were recruited, and 2,336 subjects who fully completed both questionnaires and who had valid spirometry measurements were analyzed. Persistent airflow obstruction (AO) was defined by a postbronchodilator forced expiratory volume in 1 second/forced vital capacity <0.70. Receiver operating characteristic curves, net reclassification improvement, and integrated discrimination improvement were used to examine the ability of the COPD-PS and IPAG questionnaires to discriminate between subjects with and without AO. Results The overall area under the receiver operating characteristic curve for the COPD-PS questionnaire was 0.747 (95% confidence interval [CI], 0.707–0.788) and for the IPAG was 0.775 (95% CI, 0.735–0.816), with no significant difference (P=0.09). The net reclassification improvement and integrated discrimination improvement were −0.107 (95% CI, −0.273–0.058; P=0.203) and −0.014 (95% CI, −0.033–0.006; P=0.182), respectively. Conclusion The five-item COPD-PS questionnaire was comparable to the eight-item IPAG for discriminating between subjects with and without AO. The COPD-PS is a simple and useful screening questionnaire for persistent AO.

Serum B cell–activating factor (BAFF) level in connective tissue disease associated interstitial lung disease

BackgroundInterstitial lung diseases (ILDs) are common in patients with connective tissue diseases (CTDs). Although the diagnosis of an underlying CTD in ILD (CTD-ILD) affects both prognosis and treatment, it is sometimes difficult to distinguish CTD-ILD from chronic fibrosing interstitial pneumonia (CFIP). B cell–activating factor belonging to the tumour necrosis factor family (BAFF) plays a crucial role in B cell development, survival, and antibody production.MethodsWe examined serum levels of BAFF, surfactant protein D (SP-D), and Krebs von den Lungen-6 (KL-6) in 33 patients with CTD-ILD, 16 patients with undifferentiated CTD-ILD, 19 patients with CFIP, and 26 healthy volunteers. And we analysed the relationship between serum BAFF levels and pulmonary function, as well as the expression of BAFF in the lung tissue of patients with CTD-ILD.ResultsSerum levels of BAFF were significantly higher in CTD-ILD patients compared to healthy subjects and CFIP patients. However, there were no significant differences in serum levels of SP-D and KL-6. Furthermore, serum BAFF levels in CTD-ILD patients were inversely correlated with pulmonary function. BAFF was strongly expressed in the lungs of CTD-ILD patients, but weakly in normal lungs.DiscussionThis is the first study to demonstrate that serum BAFF levels were significantly higher in CTD-ILD patients compared to healthy subjects and CFIP patients. Furthermore, serum BAFF levels were correlated with pulmonary function. We consider that serum BAFF levels in patients with CTD-ILD reflect the presence of ILDs disease activity and severity.ConclusionThese finding suggest that BAFF may be a useful marker for distinguishing CTD-ILD from CFIP.

Development of a self-scored persistent airflow obstruction screening questionnaire in a general Japanese population: The Hisayama study

Background The use of a simple screening questionnaire to detect persistent airflow obstruction (AO) in COPD may facilitate the early, accurate diagnosis of COPD in general practice settings. Objective This study developed an original persistent AO questionnaire for screening individuals with COPD in a general Japanese population. Methods A working group was established to generate initial draft questionnaire items about COPD. Eligible subjects aged 40 and older living in Japan were solicited to participate in a health checkup from 2014 to 2015. In study I, 2,338 subjects who fully completed the initial draft questionnaire and who had valid spirometry measurements were statistically analyzed to determine the final questionnaire items as a COPD screening questionnaire (COPD-Q). Persistent AO was defined as a post-bronchodilator FEV1/FVC <0.70. In study II, the working group analyzed the weighted scores for individual items and established a cutoff point for the COPD-Q based on the data of 2,066 subjects in the Hisayama study. Receiver operating characteristic (ROC) curves were used to examine the ability of the COPD-Q to discriminate between subjects with and without AO. Results The five-item COPD-Q was established based on 19 initial draft items in study I and the weighted scores of individual items. The overall area under the ROC curve for the COPD-Q was 0.796 (95% confidence interval, 0.707–0.788). A cutoff of 4 points resulted in a sensitivity of 71.0% and a specificity of 70.1%. The positive predictive value was 10.8%, and the negative predictive value was 97.9%. The crude odds ratio of the COPD-Q for AO was 5.8. Conclusion The five-item COPD-Q is a useful questionnaire for diagnosing persistent AO in a general Japanese population and is expected to be an effective first-stage screening tool for detecting COPD.

Napsin A levels in epithelial lining fluid as a diagnostic biomarker of primary lung adenocarcinoma

BackgroundIt is crucial to develop novel diagnostic approaches for determining if peripheral lung nodules are malignant, as such nodules are frequently detected due to the increased use of chest computed tomography scans. To this end, we evaluated levels of napsin A in epithelial lining fluid (ELF), since napsin A has been reported to be an immunohistochemical biomarker for histological diagnosis of primary lung adenocarcinoma.MethodsIn consecutive patients with indeterminate peripheral lung nodules, ELF samples were obtained using a bronchoscopic microsampling (BMS) technique. The levels of napsin A and carcinoembryonic antigen (CEA) in ELF at the nodule site were compared with those at the contralateral site. A final diagnosis of primary lung adenocarcinoma was established by surgical resection.ResultsWe performed BMS in 43 consecutive patients. Among patients with primary lung adenocarcinoma, the napsin A levels in ELF at the nodule site were markedly higher than those at the contralateral site, while there were no significant differences in CEA levels. Furthermore, in 18 patients who were undiagnosed by bronchoscopy and finally diagnosed by surgery, the napsin A levels in ELF at the nodule site were identically significantly higher than those at the contralateral site. In patients with non-adenocarcinoma, there were no differences in napsin A levels in ELF. The area under the receiver operator characteristic curve for identifying primary lung adenocarcinoma was 0.840 for napsin A and 0.542 for CEA.ConclusionEvaluation of napsin A levels in ELF may be useful for distinguishing primary lung adenocarcinoma.

A Case of Simultaneously Treated Thymoma and Lung Cancer.

症例は72歳, 男性. 胸痛自覚し当科を受診した. 胸部X線, CTにて前縦隔腫瘍とそれに接した左上区に結節影を認めた. 画像所見からは, 術前に胸腺腫と原発性肺癌 (腺癌) と考えられ, 手術を施行した. 術中迅速にて結節影は肺癌との診断となり, 拡大胸腺摘出術と左上区切除術を施行した. 胸腺腫は正岡分類で臨床病期I期であり, 紡錘細胞型, リンパ球優位型であった. 肺癌は16×12×10mmの腺癌で, pT1 N0 M0 stage IAであった. 肺癌が増えている現状では今後本症例のように胸腺腫と肺癌が同時に発見されることが増えると予想された. また胸腺腫では長期経過観察で胸腺外悪性腫瘍の合併が有意に多いとされており, 肺癌を含め, 他臓器の悪性腫瘍合併について充分注意すべきと考えられた.