MicroRNA signature of small-cell lung cancer after treatment failure: impact on oncogenic targets by miR-30a-3p control.

Small-cell lung cancer (SCLC) is associated with a high mortality rate and limited treatment efficacy. We created a microRNA (miRNA) expression signature by RNA sequencing using specimens from patients with SCLC who had failed treatment. Forty-nine miRNAs were downregulated in SCLC tissues and were candidate tumor-suppressive miRNAs. In this signature, both guide and passenger strands were downregulated for five miRNAs (miR-30a, miR-34b, miR-34c, miR-223, and miR-4529). Recent studies have revealed that passenger strands of miRNAs are involved in the molecular pathogenesis of human cancer. Although miR-30a-5p (the guide strand) has been shown to be a tumor-suppressive miRNA in various types of cancers, miR-30a-3p (the passenger strand) function is not well characterized in SCLC cells. We investigated the functional significance of miR-30a-3p and oncogenic genes regulated by miR-30a-3p in SCLC cells. Ectopic expression assays showed that miR-30a-3p expression inhibited cell proliferation and induced cell cycle arrest and apoptosis in two SCLC cell lines. Furthermore, in silico database searches and gene expression assays identified 25 genes as putative targets of miR-30a-3p in SCLC cells. Luciferase reporter assays revealed that downstream neighbor of SON (DONSON) was directly regulated by miR-30a-3p in SCLC cells. Knockdown of DONSON induced cell cycle arrest in SCLC cells and DONSON overexpression were detected in SCLC clinical samples. Analyzing the regulatory networks of tumor-suppressive miRNAs may lead to the identification of therapeutic targets in SCLC.

Regulation of Oncogenic Targets by Tumor-Suppressive miR-150-3p in Lung Squamous Cell Carcinoma.

Several recent studies have shown that both strands of certain miRNAs derived from miRNA duplexes are involved in cancer pathogenesis. Our own recent studies revealed that both strands of the miR-150 duplex act as tumor-suppressive miRNAs in lung adenocarcinoma (LUAD) through the targeting of several oncogenes. The aim of the study here was to further investigate the tumor-suppressive roles of miR-150-3p (the passenger strand) in lung squamous cell carcinoma (LUSQ) and its control of cancer-promoting genes in LUSQ cells. The downregulation of miR-150-3p in LUSQ tissues was confirmed by data in The Cancer Genome Atlas (TCGA). The ectopic expression of miR-150-3p attenuated cancer cell aggressive features, e.g., cell cycle arrest, migration and invasive abilities. Our target search strategy successfully identified a total of 49 putative targets that were listed as subjects of miR-150-3p regulation in LUSQ cells. Interestingly, among these targets, 17 genes were categorized as related to the "cell cycle" based on Gene Ontology (GO) classification, namely CENPA, CIT, CCNE1, CCNE2, TIMELESS, BUB1, MCM4, HELLS, SKA3, CDCA2, FANCD2, NUF2, E2F2, SUV39H2, CASC5, ZWILCH and CKAP2). Moreover, we show that the expression of HELLS (helicase, lymphoid specific) is directly controlled by miR-150-3p, and its expression promotes the malignant phenotype of LUSQ cells.

Molecular Signature of Small Cell Lung Cancer after Treatment Failure: The MCM Complex as Therapeutic Target.

Small cell lung cancer (SCLC) is a highly aggressive cancer, and patients who become refractory to first-line treatment have a poor prognosis. The development of effective treatment regimens is urgently needed. In this study, we identified a gene expression signature of SCLC after treatment failure using SCLC clinical specimens (GEO accession number: GSE162102). A total of 1,136 genes were significantly upregulated in SCLC tissues. These upregulated genes were subjected to KEGG pathway analysis, and "cell cycle", "Fanconi anemia", "alcoholism", "systemic lupus erythematosus", "oocyte meiosis", "homologous recombination", "DNA replication", and "p53 signaling" were identified as the enriched pathways among the genes. We focused on the cell cycle pathway and investigated the clinical significance of four genes associated with this pathway: minichromosome maintenance (MCM) 2, MCM4, MCM6, and MCM7. The overexpression of these MCM genes was confirmed in SCLC clinical specimens. Knockdown assays using siRNAs targeting each of these four MCM genes showed significant attenuation of cancer cell proliferation. Moreover, siRNA-mediated knockdown of each MCM gene enhanced the cisplatin sensitivity of SCLC cells. Our SCLC molecular signature based on SCLC clinical specimens after treatment failure will provide useful information to identify novel molecular targets for this disease.

Replisome genes regulation by antitumor miR-101-5p in clear cell renal cell carcinoma.

Analysis of microRNA (miRNA) regulatory networks is useful for exploring novel biomarkers and therapeutic targets in cancer cells. The Cancer Genome Atlas dataset shows that low expression of both strands of pre-miR-101 (miR-101-5p and miR-101-3p) significantly predicted poor prognosis in clear cell renal cell carcinoma (ccRCC). The functional significance of miR-101-5p in cancer cells is poorly understood. Here, we focused on miR-101-5p to investigate the antitumor function and its regulatory networks in ccRCC cells. Ectopic expression of mature miRNAs or siRNAs was investigated in cancer cell lines to characterize cell function, ie, proliferation, apoptosis, migration, and invasion. Genome-wide gene expression and in silico database analyses were undertaken to predict miRNA regulatory networks. Expression of miR-101-5p caused cell cycle arrest and apoptosis in ccRCC cells. Downstream neighbor of son (DONSON) was directly regulated by miR-101-5p, and its aberrant expression was significantly associated with shorter survival in propensity score-matched analysis (P = .0001). Knockdown of DONSON attenuated ccRCC cell aggressiveness. Several replisome genes controlled by DONSON and their expression were closely associated with ccRCC pathogenesis. The antitumor miR-101-5p/DONSON axis and its modulated replisome genes might be a novel diagnostic and therapeutic target for ccRCC.

Involvement of Dual Strands of miR-143 (miR-143-5p and miR-143-3p) and Their Target Oncogenes in the Molecular Pathogenesis of Lung Adenocarcinoma.

Our analyses of tumor-suppressive microRNAs (miRNAs) and their target oncogenes have identified novel molecular networks in lung adenocarcinoma (LUAD). Moreover, our recent studies revealed that some passenger strands of miRNAs contribute to cancer cell malignant transformation. Downregulation of both strands of the miR-143 duplex was observed in LUAD clinical specimens. Ectopic expression of these miRNAs suppressed malignant phenotypes in cancer cells, suggesting that these miRNAs have tumor-suppressive activities in LUAD cells. Here, we evaluated miR-143-5p molecular networks in LUAD using genome-wide gene expression and miRNA database analyses. Twenty-two genes were identified as potential miR-143-5p-controlled genes in LUAD cells. Interestingly, the expression of 11 genes (MCM4, RAD51, FAM111B, CLGN, KRT80, GPC1, MTL5, NETO2, FANCA, MTFR1, and TTLL12) was a prognostic factor for the patients with LUAD. Furthermore, knockdown assays using siRNAs showed that downregulation of MCM4 suppressed cell growth, migration, and invasion in LUAD cells. Aberrant expression of MCM4 was confirmed in the clinical specimens of LUAD. Thus, we showed that miR-143-5p and its target genes were involved in the molecular pathogenesis of LUAD. Identification of tumor-suppressive miRNAs and their target oncogenes may be an effective strategy for elucidation of the molecular oncogenic networks of this disease.

Aberrantly expressed PLOD1 promotes cancer aggressiveness in bladder cancer: a potential prognostic marker and therapeutic target.

Bladder cancer (BC) is the ninth most malignant tumor worldwide. Some BC patients will develop muscle-invasive BC (MIBC), which has a 5-year survival rate of approximately 60% due to metastasis. As such, there is an urgent need for novel therapeutic and diagnostic targets for MIBC. Analysis of novel antitumor microRNA (miRNA)-mediated cancer networks is an effective strategy for exploring therapeutic targets and prognostic markers in cancers. Our previous miRNA analysis revealed that miR-140-5p acts as an antitumor miRNA in BC cells. Here, we investigated miR-140-5p regulation of BC molecular pathogenesis. Procollagen-lysine, 2-oxoglutarate 5-dioxygenase 1 (PLOD1) was found to be directly regulated by miR-140-5p, and aberrant expression of PLOD1 was observed in BC clinical specimens. High PLOD1 expression was significantly associated with a poor prognosis (disease-free survival: P = 0.0204; overall survival: P = 0.000174). Multivariate analysis showed PLOD1 expression to be an independent prognostic factor in BC patients (hazard ratio = 1.51, P = 0.0099). Furthermore, downregulation of PLOD1 by siRNAs and a specific inhibitor significantly decreased BC cell aggressiveness. Aberrant expression of PLOD1 was closely associated with BC pathogenesis. In summary, the present study showed that PLOD1 may be a potential prognostic marker and therapeutic target for BC.

Molecular Pathogenesis of Gene Regulation by the miR-150 Duplex: miR-150-3p Regulates TNS4 in Lung Adenocarcinoma.

Based on our miRNA expression signatures, we focused on miR-150-5p (the guide strand) and miR-150-3p (the passenger strand) to investigate their functional significance in lung adenocarcinoma (LUAD). Downregulation of miR-150 duplex was confirmed in LUAD clinical specimens. In vitro assays revealed that ectopic expression of miR-150-5p and miR-150-3p inhibited cancer cell malignancy. We performed genome-wide gene expression analyses and in silico database searches to identify their oncogenic targets in LUAD cells. A total of 41 and 26 genes were identified as miR-150-5p and miR-150-3p targets, respectively, and they were closely involved in LUAD pathogenesis. Among the targets, we investigated the oncogenic roles of tensin 4 (TNS4) because high expression of TNS4 was strongly related to poorer prognosis of LUAD patients (disease-free survival: p = 0.0213 and overall survival: p = 0.0003). Expression of TNS4 was directly regulated by miR-150-3p in LUAD cells. Aberrant expression of TNS4 was detected in LUAD clinical specimens and its aberrant expression increased the aggressiveness of LUAD cells. Furthermore, we identified genes downstream from TNS4 that were associated with critical regulators of genomic stability. Our approach (discovery of anti-tumor miRNAs and their target RNAs for LUAD) will contribute to the elucidation of molecular networks involved in the malignant transformation of LUAD.

Regulation of KIF2A by Antitumor miR-451a Inhibits Cancer Cell Aggressiveness Features in Lung Squamous Cell Carcinoma.

In the human genome, miR-451a is encoded close to the miR-144 on chromosome region 17q11.2. Our previous study showed that both strands of pre-miR-144 acted as antitumor miRNAs and were involved in lung squamous cell carcinoma (LUSQ) pathogenesis. Here, we aimed to investigate the functional significance of miR-451a and to identify its targeting of oncogenic genes in LUSQ cells. Downregulation of miR-451a was confirmed in LUSQ clinical specimens, and low expression of miR-451a was significantly associated with poor prognosis of LUSQ patients (overall survival: p = 0.035, disease-free survival: p = 0.029). Additionally, we showed that ectopic expression of miR-451a significantly blocked cancer cell aggressiveness. In total, 15 putative oncogenic genes were shown to be regulated by miR-451a in LUSQ cells. Among these targets, high kinesin family member 2A (KIF2A) expression was significantly associated with poor prognosis (overall survival: p = 0.043, disease-free survival: p = 0.028). Multivariate analysis showed that KIF2A expression was an independent prognostic factor in patients with LUSQ (hazard ratio = 1.493, p = 0.034). Aberrant KIF2A expression promoted the malignant transformation of this disease. Analytic strategies based on antitumor miRNAs and their target oncogenes are effective tools for identification of novel molecular pathogenesis of LUSQ.

Involvement of dual-strand of the miR-144 duplex and their targets in the pathogenesis of lung squamous cell carcinoma.

The prognosis of patients with advanced-stage lung squamous cell carcinoma (LUSQ) is poor, and effective treatment protocols are limited. Our continuous analyses of antitumor microRNAs (miRNAs) and their oncogenic targets have revealed novel oncogenic pathways in LUSQ. Analyses of our original miRNA expression signatures indicated that both strands of miR-144 (miR-144-5p, the passenger strand; miR-144-3p, the guide strand) showed decreased expression in cancer tissues. Additionally, low expression of miR-144-5p significantly predicted a poor prognosis in patients with LUSQ by The Cancer Genome Atlas database analyses (overall survival, P = 0.026; disease-free survival, P = 0.023). Functional assays revealed that ectopic expression of miR-144-5p and miR-144-3p significantly blocked the malignant abilities of LUSQ cells, eg, cancer cell proliferation, migration, and invasion. In LUSQ cells, 13 and 15 genes were identified as possible oncogenic targets that might be regulated by miR-144-5p and miR-144-3p, respectively. Among these targets, we identified 3 genes (SLC44A5, MARCKS, and NCS1) that might be regulated by both strands of miR-144. Interestingly, high expression of NCS1 predicted a significantly poorer prognosis in patients with LUSQ (overall survival, P = 0.013; disease-free survival, P = 0.048). By multivariate analysis, NCS1 expression was found to be an independent prognostic factor for patients with LUSQ patients. Overexpression of NCS1 was detected in LUSQ clinical specimens, and its aberrant expression enhanced malignant transformation of LUSQ cells. Our approach, involving identification of antitumor miRNAs and their targets, will contribute to improving our understanding of the molecular pathogenesis of LUSQ.

Dual strands of the miR-145 duplex (miR-145-5p and miR-145-3p) regulate oncogenes in lung adenocarcinoma pathogenesis.

Our original microRNA (miRNA) expression signatures (based on RNA sequencing) revealed that both strands of the miR-145 duplex (miR-145-5p, the guide strand, and miR-145-3p, the passenger strand) were downregulated in several types of cancer tissues. Involvement of passenger strands of miRNAs in cancer pathogenesis is a new concept in miRNA biogenesis. In our continuing analysis of lung adenocarcinoma (LUAD) pathogenesis, we aimed here to identify important oncogenes that were controlled by miR-145-5p and miR-145-3p. Downregulation of miR-145-5p and miR-145-3p was confirmed in LUAD clinical specimens. Functional assays showed that miR-145-3p significantly blocked the malignant abilities in LUAD cells, e.g., cancer cell proliferation, migration and invasion. Thus, the data showed that expression of the passenger strand of the miR-145-duplex acted as an anti-tumor miRNA. In LUAD cells, we identified four possible target genes (LMNB2, NLN, SIX4, and DDC) that might be regulated by both strands of miR-145. Among the possible targets, high expression of LMNB2 predicted a significantly poorer prognosis of LUAD patients (disease-free survival, p = 0.0353 and overall survival, p = 0.0017). Overexpression of LMNB2 was detected in LUAD clinical specimens and its aberrant expression promoted malignant transformation of LUAD cells. Genes regulated by anti-tumor miR-145-5p and miR-145-3p are closely involved in the molecular pathogenesis of LUAD. We suggest that they are promising prognostic markers for this disease. Our approach, based on the roles of anti-tumor miRNAs, will contribute to improved understanding of the molecular pathogenesis of LUAD.

Epidemiology of asthma-chronic obstructive pulmonary disease overlap (ACO).

The term "asthma-COPD overlap" (ACO) has been applied to the condition in which a person has persistent airflow limitation with clinical features of both asthma and COPD. The certain definition and diagnostic criteria for ACO have not yet been established, and ACO prevalence has varied widely in studies: from 0.9% to 11.1% in the general population, from 11.1% to 61.0% in asthma patients, and from 4.2% to 66.0% in COPD patients. Furthermore, the frequency of exacerbations and prognosis in ACO patients have not been clearly demonstrated. Although ACO consists with several subgroups of patients with distinct clinical and pathophysiological features, it would be important to propose a standardized definition of and/or diagnostic criteria for ACO based on biomarkers and objective measures, even if it is tentative. It may lead cohort studies with large population or clinical trials around the world.

IL-13 enhances mesenchymal transition of pulmonary artery endothelial cells via down-regulation of miR-424/503 in vitro.

Pulmonary arterial hypertension (PAH) has a major effect on life expectancy with functional degeneracy of the lungs and right heart. Interleukin-13 (IL-13), one of the type 2 cytokines mainly associated with allergic diseases, has recently been reported to be associated with Schistosomiasis-associated PAH which shares pathological features with other forms of PAH, such as idiopathic PAH and connective tissue disease-associated PAH. But a direct pathological role of IL-13 in the development of PAH has not been explored. We examined the effects of recombinant human IL-13 on the function of primary human pulmonary artery endothelial cells (HPAECs) to examine how IL-13 influences exacerbation of PAH. IL-13 increased the expression of Rictor, which is a key molecule of mammalian target of rapamycin complex 2. Treatment of IL-13 induced HPAEC migration via Rictor. Rictor was directly regulated by both miR-424 and 503 (miR-424/503). Therefore, IL-13 increases Rictor level by regulating miR-424/503, causing the increase of HPAEC migration. Since enhancement of HPAEC migration in the lung is thought to be associated with PAH, these data suggest that IL-13 takes some roles in exacerbating PAH.

Downregulation of matrix metalloproteinase 14 by the antitumor miRNA, miR-150-5p, inhibits the aggressiveness of lung squamous cell carcinoma cells.

In the present study, in order to elucidate the aggressive nature of lung squamous cell carcinoma (LUSQ), we investigated the oncogenic RNA networks regulated by antitumor microRNAs (miRNAs or miRs) in LUSQ cells. The analysis of our original miRNA expression signatures of human cancers revealed that microRNA­150­5p (miR­150­5p) was downregulated in various types of cancer, indicating that miR­150­5p acts as an antitumor miRNA by targeting several oncogenic genes. Thus, the aims of this study were to investigate the antitumor roles of miR­150­5p in LUSQ cells and to identify oncogenes regulated by miR­150­5p that are involved in the aggressive behavior of LUSQ. The downregulation of miR­150­5p was validated in clinical samples of LUSQ and cell lines (SK-MES­1 and EBC­1). The ectopic overexpression of miR­150­5p significantly suppressed cancer cell aggressiveness. Comprehensive gene expression analyses revealed that miR­150­5p regulated 9 genes in the LUSQ cells. Among these, matrix metalloproteinase 14 (MMP14) was found to be a direct target of miR­150­5p, as shown by luciferase reporter assay. The knockdown of MMP14 using siRNA against MMP14 (si-MMP14) significantly inhibited cancer cell migration and invasion. The overexpression of MMP14 was detected in clinical specimens of LUSQ by immunohistochemistry. On the whole, these findings suggest that the downregulation of miR­150­5p and the overexpression of MMP14 may be deeply involved in the pathogenesis of LUSQ.

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

BACKGROUND: It 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. METHODS: In 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. RESULTS: We 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. CONCLUSION: Evaluation of napsin A levels in ELF may be useful for distinguishing primary lung adenocarcinoma.

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.

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.

MRI studies of spinal visceral larva migrans syndrome.

We report serial MR findings in four patients with myelitis caused by visceral larva migrans syndrome due to Toxocara canis or Ascaris suum infection. MR imaging revealed spinal cord swelling with or without gadolinium enhancement in three patients. T2-weighted images showed high signal intensities preferentially located in both lateral and posterior columns. Antihelmintic and corticosteroid treatment yielded improvement in neurologic deficits and spinal lesions. However, one patient with T. canis infection relapsed associated with reappearance of MRI abnormalities.