SpringerActa Medica Okayama0171-521613852012DNA methylation status of REIC/Dkk-3 gene in human malignancies799809ENTatsuroHayashiHiroakiAsanoShinichiToyookaKazunoriTsukudaJunichiSohTadahikoShienNarutoTairaYuhoMakiNorimitsuTanakaHiroyoshiDoiharaYasutomoNasuNam-hoHuhShinichiroMiyoshiThe REIC (reduced expression in immortalized cells)/Dkk-3 is down-regulated in various cancers and considered to be a tumor suppressor gene. REIC/Dkk-3 mRNA has two isoforms (type-a,b). REIC type-a mRNA has shown to be a major transcript in various cancer cells, and its promoter activity was much stronger than that of type-b. In this study, we examined the methylation status of REIC/Dkk-3 type-a in a broad range of human malignancies.
We examined REIC/Dkk-3 type-a methylation in breast cancers, non-small-cell lung cancers, gastric cancers, colorectal cancers, and malignant pleural mesotheliomas using a quantitative combined bisulfite restriction analysis assay and bisulfate sequencing. REIC/Dkk-3 type-a and type-b expression was examined using reverse transcriptional PCR. The relationships between the methylation and clinicopathological factors were analyzed.
The rate of REIC/Dkk-3 type-a methylation ranged from 26.2 to 50.0% in the various primary tumors that were examined. REIC/Dkk-3 type-a methylation in breast cancer cells was significantly heavier than that in the other cell lines that we tested. REIC/Dkk-3 type-a methylation was inversely correlated with REIC/Dkk-3 type-a expression. There was a correlation between REIC/Dkk-3 type-a and type-b mRNA expression. REIC/Dkk-3 type-a expression was restored in MDA-MB-231 cells using 5-aza-2'-deoxycytidine treatment. We found that estrogen receptor-positive breast cancers were significantly more common among the methylated group than among the non-methylated group.
REIC/Dkk-3 type-a methylation was frequently detected in a broad range of cancers and appeared to play a key role in silencing REIC/Dkk-3 type-a expression in these malignancies.No potential conflict of interest relevant to this article was reported.Okayama University Medical SchoolActa Medica Okayama0386-300X6812014Preclinical Evaluation of MicroRNA-34b/c Delivery for Malignant Pleural Mesothelioma2326ENTsuyoshiUenoShinichiToyookaTakuyaFukazawaTakafumiKuboJunichiSohHiroakiAsanoTakayukiMuraokaNorimitsuTanakaYuhoMakiKazuhikoShienMasashiFurukawaMasakiyoSakaguchiHiromasaYamamotoKazunoriTsukudaShinichiroMiyoshiOriginal Article10.18926/AMO/52140The microRNA-34s (miR-34s) have p53 response elements in their 5ʼ-flanking regions and demonstrate tumor-suppressive functions. In malignant pleural mesothelioma (MPM), we previously reported that expression of miR-34b and miR-34c (miR-34b/c) was frequently downregulated by methylation in MPM cell lines and primary tumors. The forced overexpression of miR-34b/c showed significant antitumor effects with the induction of apoptosis in MPM cells. In this study, we examined the in vivo antitumor effects of miR-34b/c using adenovirus vector on MPM. We subcutaneously transplanted NCI-H290, a human MPM cell line, into BALB/C mice and injected adenovirus vector expressing miR-34b/c, luciferase driven by the cytomegalovirus promoter (Ad-miR-34b/c or Ad-Luc), or PBS control into tumors over 5mm in diameter. A statistically significant growth inhibition of the tumor volume was observed in the Ad-miR-34b/c group from day 6 onward compared to the Ad-Luc group. The inhibition
rate of Ad-miR-34b/c, compared to the tumor volume treated with Ad-Luc, was 58.6% on day 10 and 54.7% on day13. Our results indicate that adenovirus-mediated miR-34b/c gene therapy could be useful for the clinical treatment of MPM.No potential conflict of interest relevant to this article was reported.Elsevier Ireland Ltd.Acta Medica Okayama0169-50028232013The degree of microRNA-34b/c methylation in serum-circulating DNA is associated with malignant pleural mesothelioma485490ENTakayukiMuraokaJunichiSohShinichiToyookaKeisukeAoeNobukazuFujimotoShinsukeHashidaYuhoMakiNorimitsuTanakaKazuhikoShienMasashiFurukawaHiromasaYamamotoHiroakiAsanoKazunoriTsukudaTakumiKishimotoTakemiOtsukiShinichiroMiyoshiObjectives: Malignant pleural mesothelioma (MPM) is an aggressive tumor with a poor prognosis. microRNA-34b/c (miR-34b/c), which plays an important role in the pathogenesis of MPM, is frequently downregulated by DNA methylation in approximately 90% of MPM cases. In this study, we estimated the degree of miR-34b/c methylation in serum-circulating DNA using a digital methylation specific PCR assay (MSP).
Materials and methods: A real-time MSP assay was performed using the SYBR Green method. The melting temperature (Tm) of each PCR product was examined using a melting curve analysis. For a digital MSP assay, 40 wells were analyzed per sample. A total of 110 serum samples from 48 MPM cases, 21 benign asbestos pleurisy (BAP) cases, and 41 healthy volunteers (HVs) were examined.
Results: Positive range of Tm value for miR-34b/c methylation was defined as 77.71-78.79 degrees C which was the mean 3 standard deviations of 40 wells of a positive control. The number of miR-34b/c methylated wells was counted per sample according to this criterion. The number of miR-34b/c methylated wells in MPM cases was significantly higher than that in BAP cases (P = 0.03) or HVs (P < 0.001). Advanced MPM cases tended to have higher number of miR-34b/c methylated wells than early MPM cases. Receiver-operating characteristic (ROC) curve analysis revealed that three number of miR-34b/c methylated wells per sample was the best cut-off of positivity of MPM with a 67% of sensitivity and a 77% specificity for prediction. The area under the ROC curve was 0.77.
Conclusions: Our digital MSP assay can quantify miR-34b/c methylation in serum-circulating DNA. The degree of miR-34b/c methylation in serum-circulating DNA is associated with MPM, suggesting that this approach might be useful for the establishment of a new detection system for MPM.No potential conflict of interest relevant to this article was reported.Acta Medica Okayama1021-335X2912013Impact of GLUT1 and Ki-67 expression on early-stage lung adenocarcinoma diagnosed according to a new international multidisciplinary classification133140ENYuhoMakiJunichiSohKouichiIchimuraKazuhikoShienMasashiFurukawaTakayukiMuraokaNorimitsuTanakaTsuyoshiUenoHiromasaYamamotoHiroakiAsanoKazunoriTsukudaShinichiToyookaShinichiroMiyoshiHigh expression levels of glucose transporter isoform 1 (GLUT1) and Ki-67 are reportedly associated with malignancy-related clinicopathological factors in malignant tumors. Recently, a new histological IASLC/ATS/ERS classification for lung adenocarcinoma was proposed. In this study, we investigated the clinicopathological impact of GLUT1 and Ki-67 expression on early-stage lung adenocarcinoma classified according to the IASLC/ATS/ERS classification. One hundred and five patients with completely resected stage IA lung adenocarcinoma were retrospectively classified into two groups, a 'non-invasive type' (n=31) or an 'invasive type' (n=74), based on the IASLC/ATS/ERS classification. GLUT1 and Ki-67 expression status was evaluated using immunohistochemistry. The epidermal growth factor receptor (EGFR) and KRAS mutation status was determined using PCR-based assays. Positive GLUT1 and Ki-67 expression and EGFR and KRAS mutations were detected in 28 (27%), 33 (31%), 51 (49%) and 5 (8%) cases, respectively. Positive GLUT1 expression was significantly associated with a wild-type EGFR and mutant KRAS status. A multivariate analysis revealed that positive GLUT1 expression was independently associated with the 'invasive type'. In multivariate analyses for overall survival (OS) and disease-free survival (DFS), positive Ki-67 and GLUT1 expression was the only independent factor for a poor OS (P=0.012) and DFS (P=0.040), respectively. In addition, when stratified according to the GLUT1 and Ki-67 status, double-positive cases had the poorest DFS and OS times, compared with the other categories. Positive GLUT1 expression is associated with the invasive character of early-stage lung adenocarcinoma and with early disease relapse. Our results strongly suggest that GLUT1 and Ki-67 play important roles in acquiring biological malignant potential in early-stage lung adenocarcinoma.No potential conflict of interest relevant to this article was reported.Elsevier Ireland Ltd.Acta Medica Okayama0169-50027612012Strong anti-tumor effect of NVP-AUY922, a novel Hsp90 inhibitor, on non-small cell lung cancer2631ENTsuyoshiUenoKazunoriTsukudaShinichiToyookaMidoriAndoMunenoriTakaokaJunichiSohHiroakiAsanoYuhoMakiTakayukiMuraokaNorimitsuTanakaKazuhikoShienMasashiFurukawaTomokiYamatsujiKatsuyukiKiuraYoshioNaomotoShinichiroMiyoshiThe anti-tumor activity of a newly developed Hsp90 inhibitor, NVP-AUY922 (AUY922), against non-small cell lung cancer (NSCLC) was examined. Twenty-one NSCLC cell lines were used, the somatic alterations of which were characterized. Cell proliferation was analyzed using a modified MTS assay. Expression of the client proteins was assessed using Western blotting. The cell cycle was analyzed using flow cytometry. The IC50 value of AUY922 for the NSCLC cell lines ranged from 5.2 to 860 nM (median, 20.4 nM). Based on previous data, cells with an IC50 of less than 50 nM were classified as sensitive cells and 19 of the 21 NSCLC cell lines were judged to be sensitive. The IC50 of five malignant pleural mesothelioma (MPM) cell lines revealed that the MPM cells had a significantly higher IC50 value (median, 89.2 nM; range, 22.2-24, 100 nM) than the NSCLC cells (p = 0.015). There was significant depletion of both the total and phosphorylated client proteins - EGFR, MET, HERZ and ART - at low drug concentrations (50-100 nM) in drug-sensitive cell lines. Cell-cycle analysis was performed for two sensitive cell lines, H1975 and H838. Following AUY922 treatment, an increase in the sub-G(0)-G(1) cell population, as well as appearance of cleaved PARP expression, indicated the induction of apoptosis. In conclusion, AUY922 was effective against most NSCLC cell lines, independent of the type of known molecular alteration, and appears to be a promising new drug for the treatment of NSCLC. (C) 2011 Elsevier Ireland Ltd. All rights reserved.No potential conflict of interest relevant to this article was reported.Elsevier Ireland Ltd.Acta Medica Okayama0169-50027612012Frequent methylation and oncogenic role of microRNA-34b/c in small-cell lung cancer3238ENNorimitsuTanakaShinichiToyookaJunichiSohTakafumiKuboHiromasaYamamotoYuhoMakiTakayukiMuraokaKazuhikoShienMasashiFurukawaTsuyoshiUenoHiroakiAsanoKazunoriTsukudaKeisukeAoeShinichiroMiyoshiSmall-cell lung cancer (SCLC) is an aggressive tumor with a dismal prognosis among primary lung cancers. MicroRNAs (miRNAs) can act as oncogenes or tumor-suppressor genes in human malignancy. The miR-34 family is comprised of tumor-suppressive miRNAs, and its reduced expression by methylation has been reported in various cancers, including non-small cell lung cancer (NSCLC). In this study, we investigated the alteration and tumor-suppressive impact of miR-34s in SCLC. The methylation of miR-34a and miR-34b/c was observed in 4 (36%) and 7 (64%) of 11 SCLC cell lines, respectively. Among the 27 SCLC clinical specimens, miR-34a and miR-34b/c were methylated in 4(15%) and 18 (67%), respectively. In contrast, 13 (28%) miR-34a methylated cases and 12 (26%) miR-34b/c methylated cases were found in 47 NSCLC primary tumors. The frequency of miR-34b/c methylation was significantly higher in SCLC than in NSCLC (p < 0.001). The expressions of miR-34s were reduced in methylated cell lines and tumors and restored after 5-aza-2'-deoxycytidine treatment, indicating that methylation was responsible for the reduced expression of miR-34s. Because the frequency of methylation was higher in miR-34b/c, we focused on miR-34b/c for a functional analysis. We examined the effect of miR-34b/c introduction on cell proliferation, migration and invasion. The transfection of miR-34b/c to two SCLC cell lines (H1048 and SBC5) resulted in the significant inhibition of cell growth, migration, and invasion, compared with control transfectants. Our results indicate that the aberrant methylation of miR-34b/c plays an important role in the pathogenesis of SCLC, implying that miR-34b/c may be a useful therapeutic target for SCLC.No potential conflict of interest relevant to this article was reported.Elsevier Ireland Ltd.Acta Medica Okayama0169-50027712012Prognostic impact of cancer stem cell-related markers in non-small cell lung cancer patients treated with induction chemoradiotherapy162167ENKazuhikoShienShinichiToyookaKouichiIchimuraJunichiSohMasashiFurukawaYuhoMakiTakayukiMuraokaNorimitsuTanakaTsuyoshiUenoHiroakiAsanoKazunoriTsukudaMasaomiYamaneTakahiroOtoKatsuyukiKiuraShinichiroMiyoshiThe expression of several cancer stem cell (CSC)-related markers has been confirmed in non-small cell lung cancer (NSCLC). The aim of this study was to clarify the clinical role of CSC-related markers in patients with NSCLC undergoing induction chemoradiotherapy (CRT). Fifty patients with clinically diagnosed N2 or N3 NSCLC who underwent induction CRT with docetaxel and cisplatin concurrently with thoracic radiation followed by surgery were examined in this study. The expressions of CSC related markers (CD133, ALDH1, ABCG2, and Bmi-1) were examined using immunohistochemical staining in surgically resected specimens. Among the 50 patients, 20 patients had no residual tumor cells in the resected specimen when examined pathologically; CSC-related marker expressions and their correlation to survival were evaluated in the other 30 patients. After a median follow-up period of 72 months, the 5-year overall survival rate of the patients with CD133-positive or ALDH1-positive specimens was significantly worse than that of the patients with both CD133-negative and ALDH1-negative expressions (449% vs. 90.0%, respectively; P=0.042). In a multivariate analysis. CD133 and ALDH1 negativity (P=0.047) and cN2-3 single station metastasis (P=0.03) were significant independent prognostic factors for prolonged survival. The expressions of CSC-related markers after CRT were significantly correlated with a poor prognosis in patients with NSCLC. The development of therapeutic strategies including adjuvant therapy that take CSC-related marker positivity into consideration is likely to be a key factor in further improvements of the prognosis of patients undergoing trimodality therapy.No potential conflict of interest relevant to this article was reported.Okayama University Medical SchoolActa Medica Okayama0386-300X6712013Silenced Expression of NFKBIA in Lung Adenocarcinoma Patients with a Never-smoking History1924ENMasashiFurukawaJunichiSohHiromasaYamamotoKouichiIchimuraKazuhikoShienYuhoMakiTakayukiMuraokaNorimitsuTanakaTsuyoshiUenoHiroakiAsanoKazunoriTsukudaShinichiToyookaShinichiroMiyoshiOriginal Article10.18926/AMO/49253Nuclear factor of -light polypeptide gene enhancer in B cells inhibitor (NFKBIA), which is a tumor suppressor gene, was found to be silenced in lung adenocarcinomas. We examined NFKBIA expression, mutations in the EGFR and K-ras genes, and EML4-ALK fusion in 101 resected lung adenocarcinoma samples from never-smokers. NFKBIA expression was evaluated using immunohistochemistry. NFKBIA expression was negative in 16 of the 101 samples (15.8%). EGFR and K-ras mutations and EML4-ALK fusion were detected in 61 (60.5%), 1 (1.0%), and 2 (2.0%) of the 101 samples, respectively, in a completely mutually exclusive manner. Negative NFKBIA expression was observed significantly more frequently among the tumors with none of the three genetic alterations compared to those with such alterations (p0.009). In addition, negative NFKBIA expression was significantly more frequent among the EGFR-wild type samples compared to the EGFR-mutant samples (p0.013). In conclusion, NFKBIA expression was silenced in adenocarcinomas without EGFR/K-ras mutations or EML4-ALK fusion, suggesting that the silencing of NFKBIA may play an important role in the carcinogenesis of adenocarcinomas independent of EGFR/K-ras mutations or EML4-ALK fusion.No potential conflict of interest relevant to this article was reported.