[Show abstract][Hide abstract] ABSTRACT: Alternative polyadenylation (APA), which induces shortening of the 3′UTR, is emerging as an important phenomenon in gene regulation. APA is involved in cell proliferation, development, and cancer. APA may lead to disruption of microRNA-mediated gene silencing in cancer cells via detachment of microRNA binding sites. We studied the correlation between the APA profile and the tumor aggressiveness in cases of lung cancer. We selected the top 10 genes showing significant 3′UTR shortening in lung cancer, using the package of the Bioconductor for probe-level analyses of expression microarrays. We established and evaluated the APA score by qRT-PCR in 147 clinical specimens of non-small cell lung cancer and compared the results with the clinical outcomes and expression levels of APA-related genes, including PABPN1, CPEB1, E2F1 and proliferation markers (MKI67, TOP2A and MCM2). High APA scores were correlated with an advanced tumor stage and a poor prognosis (P < 0.001). Multivariate analysis identified the APA score as an independent prognostic factor (hazard ratio, 3.0; P = 0.03). Both lower expression of PABPN1 and higher expression of the proliferation markers were correlated with high APA scores and a poor prognosis, with suppression of PABPN1 exerting its influence independent of gain of the proliferation markers. Moreover, the APA score was correlated with the maximum standardized uptake value of the tumors on positron emission tomography (r = 0.53; P < 0.001). Our results indicate that the loss of PABPN1, a suppressor of APA, might promote tumor aggressiveness by releasing the cancer cells from microRNA-mediated gene regulation.This article is protected by copyright. All rights reserved.
[Show abstract][Hide abstract] ABSTRACT: Previously, we reported that the overexpression of fer tyrosine kinase (FER), a non-receptor tyrosine kinase, is correlated with poor postoperative prognosis and cancer-cell survival in non-small cell lung cancer (NSCLC). In the present study, we further analyzed FER-overexpressed NSCLC cases and identified various patterns of chimeric mRNAs, composed of paraja ring finger 2 (PJA2) and FER. We detected no genomic rearrangements between PJA2 and FER and attributed these chimeric mRNAs to alterations at the transcriptome level: i.e., trans-splicing. Several chimeric patterns were detected concurrently in each patient, and the pattern sets varied among patients, although the pattern in which PJA2 exon 1 was fused to FER exon 3 (designated as Pe1-Fe3 mRNA) was detected constantly. Therefore, in a wide screening for PJA2-FER mRNAs in NSCLC, we focused on this chimeric pattern as a representative chimera. In analyses of 167 NSCLC samples, Pe1-Fe3 mRNA was identified in about 10% of the patients, and the presence of chimeric mRNA was significantly correlated with a high expression level of parental FER mRNA. Furthermore, we found that the detection of Pe1-Fe3 mRNA was correlated with poor postoperative survival periods in NSCLC, consistent with a previous finding in which FER overexpression was correlated with poor postoperative prognosis in NSCLC. This report is the first to suggest a correlation between chimeric mRNA and the expression level of parental mRNA. Furthermore, our findings may be clinically beneficial, suggesting that PJA2-FER mRNAs might serve as a novel prognostic biomarker in NSCLC.
Cancer Science 11/2013; 104(11). · 3.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A man in his 70s was diagnosed with squamous cell carcinoma (cT1aN2M0) by repeated transbronchial needle aspirations (one conventional and one using endobronchial ultrasonography) of the subcarinal lymph node. Shortly after the initiation of chemoradiotherapy, he began to have chest pain with a high fever. CT showed only subcarinal lymph node swelling. Treatment with several antibiotics was started, and his fever decreased gradually. Chest CT showed shrinking of the subcarinal lymph node, and a diagnosis of infectious lymphadenopathy was made. Infectious lymphadenopathy can be difficult to diagnose because the symptoms are often non-specific and CT findings are not useful in differentiating tumour growth.
[Show abstract][Hide abstract] ABSTRACT: Unicentric Castleman's disease is a rare, benign lymphoproliferative disorder that is curable with surgical resection. However, significant bleeding often occurs during surgery because of tumor hypervascularity. We herein present a case of hyaline-vascular-type mediastinal unicentric Castleman's disease, successfully resected using video-assisted thoracoscopic surgery with preoperative embolization. In the present case, tumor hypervascularity and feeding vessels were revealed by computed tomography (CT), which led us to perform preoperative angiography and embolization to the tumor feeding arteries to reduce intraoperative bleeding. Castleman's disease should be considered in the differential diagnosis of hypervascular mediastinal tumors. Tumor vascularity should be assessed prior to surgery, and preoperative embolization should be considered.
[Show abstract][Hide abstract] ABSTRACT: Here, we show that overexpression of fer tyrosine kinase (FER), a non-receptor tyrosine kinase, predicts poor postoperative outcome and might be involved in cancer-cell survival in non-small cell lung cancer (NSCLC). Systematic screening using in silico analyses and quantitative RT-PCR revealed that FER was overexpressed in about 10% of NSCLC patients. Evaluation of FER expression using immunohistochemistry (IHC) on tissue microarrays was consistent with the mRNA level detected using quantitative RT-PCR. In analyses of 135 NSCLC patients who had undergone potential curative resection, we found that FER overexpression detected using IHC had no association with clinicopathological features such as age, sex, smoking history, histological type, disease stage, T factor, N factor, adjuvant chemotherapy history, or EGFR mutation, but was correlated with poor postoperative survival periods. A multivariate Cox regression analysis showed that this prognostic impact was independent of other clinicopathological features. In functional analyses of FER in vitro, FER exhibited a transforming activity, suggesting that it possesses oncogenic functions. We also found that human lung cancer NCI-H661 cells, which exhibited FER-outlier expression, were led to apoptosis by the knockdown of FER using RNA interference. FER overexpression might serve as a prognostic biomarker and be involved in cancer-cell survival in NSCLC.
International journal of clinical and experimental pathology 01/2013; 6(4):598-612. · 2.24 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We investigated whether the CpG island methylation of certain microRNAs was associated with the clinicopathological features and the prognosis of non-small-cell lung cancer. The methylation of mir-152, -9-3, -124-1, -124-2, and -124-3 was analyzed in 96 non-small-cell lung cancer specimens using a combined bisulfite restriction analysis. The median observation period was 49.5 months. The methylation of mir-9-3, -124-2, and -124-3 was individually associated with an advanced T factor independent of age, sex, and smoking habit. Moreover, the methylation of multiple microRNA loci was associated with a poorer progression-free survival in a univariate analysis. Our result enlightens the accumulation of aberrant DNA methylation which occurs in concordance with the tumor progression. (Cancer Sci 2011; 102: 2126–2131)
Cancer Science 10/2011; 102(12):2126 - 2131. · 3.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Zygomycosis is a life-threatening fungal infection, and its successful treatment requires early diagnosis. To establish radiologic and clinical criteria for early diagnosis, we reviewed 3 post-mortem cases with zygomycosis secondary to hematological diseases. In all cases, an irregular dilatation of pulmonary veins on computed tomography suggested venous invasion by fungal hyphae, which was confirmed at autopsy. In addition, serum samples tested negative for the Aspergillus galactomannan antigen in all cases. These distinguishing radiologic and clinical features may contribute to an earlier diagnosis; more radical treatments, such as amphotericin-B or pulmonary resection; and a more successful outcome for patients with zygomycosis.
Journal of thoracic imaging 09/2011; 27(4):W97-9. · 1.42 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: MicroRNA (miRNA) expression is frequently altered in human cancers. To search for epigenetically silenced miRNAs in non-small-cell lung cancer (NSCLC), we mapped human miRNAs on autosomal chromosomes and selected 55 miRNAs in silico. We treated six NSCLC cell lines with the DNA methylation inhibitor 5-aza-2'-deoxycytidine (5-aza-CdR) and determined the expressions of the 55 miRNAs. Fourteen miRNAs were decreased in the cancer cell lines and were induced after 5-aza-CdR treatment. After a detailed DNA methylation analysis, we found that mir-34b and mir-126 were silenced by DNA methylation. Mir-34b was silenced by the DNA methylation of its own promoter, whereas mir-126 was silenced by the DNA methylation of its host gene, EGFL7. A chromatin immunoprecipitation assay revealed H3K9me2 and H3K9me3 in mir-34b and EGFL7, and H3K27me3 in EGFL7. The overexpression of mir-34b and mir-126 decreased the expression of c-Met and Crk, respectively. The 5-aza-CdR treatment of lung cancer cell line resulted in increased mir-34b expression and decreased c-Met protein. We next analyzed the DNA methylation status of these miRNAs using 99 primary NSCLCs. Mir-34b and mir-126 were methylated in 41 and 7% of all the cases, respectively. The DNA methylation of mir-34b was not associated with c-Met expression determined by immunohistochemistry, but both mir-34b methylation (p = 0.007) and c-Met expression (p = 0.005) were significantly associated with lymphatic invasion in a multivariate analysis. The DNA methylation of mir-34b can be used as a biomarker for an invasive phenotype of lung cancer.
International Journal of Cancer 06/2011; 130(11):2580-90. · 6.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Rapid amplification of cDNA ends (RACE) has widely been used to determine both ends of the cDNA from its partial sequence. Conventionally, 5'- and 3'-RACE products were ligated at a restriction site in the overlap region to reconstruct the full-length cDNA; however, reconstruction is difficult if no appropriate restriction enzymes are available. Here, we report a novel method to reconstruct full-length cDNA with DNA polymerase. Instead of usual PCR, chain reactions were avoided and the elongation time was shortened, which enables non-specific products or undesired point mutations to be minimized. We successfully reconstructed and TA-cloned a full-length cDNA of echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) fusion gene variant 2 from RACE products obtained from a surgically resected lung adenocarcinoma sample. We also evaluated some parameters to provide recommendations for this new method.
[Show abstract][Hide abstract] ABSTRACT: Since the discovery of RNA interference, short interfering RNA (siRNA) has become a standard research tool. However, expression of siRNA in lung alveolar epithelial cells has remained a problem. Adeno-associated virus (AAV) vectors are known to have low toxicity, and AAV type 5 vectors transduce these cells efficiently. In this study, LacZ expression was higher using AAV2/5-LacZ and LA-4 cells compared with transfection of plasmid or transduction to 3T12-3 cells. The authors designed 10 different siRNAs against mouse transforming growth factor β1 (Tgfβ1), selected one with the highest knockdown efficiency, and transduced the AAV vectors carrying the short hairpin RNA (shRNA) to target cells. The AAV vectors transduced LA-4 cells 50 times more efficiently than 3T12-3 cells, and suppression of Tgfβ1 protein expression was similar, at approximately 50%. Knockdown of mRNA was only seen in LA-4 cells. Inhibition of Tgfβ1 resulted in higher number of LA-4 cells, lower number of 3T12-3 cells, and decreased procollagen expression in LA-4 cells. Higher transduction was seen in H23 cells than in H1975 cells, and low transduction was seen MH-S cells. This study shows that AAV2/5 can be used to carry shRNA and suppress gene function in lung alveolar epithelium-derived cells.
Experimental Lung Research 01/2011; 37(3):175-85. · 1.47 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A 60-year-old man was given a clinical diagnosis of sarcoidosis, with enlarged mediastinal and hilar lymphadenopathy by chest CT, high levels of angiotensin-converting enzyme, and gallium scintigraphy findings. After 2 years follow-up, chest CT showed that only the right superior lobe bronchial lymph node had enlarged, occluding the right B1 bronchus, but other enlarged lymph nodes had not changed in size. We performed bronchoscopy to evaluate the occlusion of the right B1 bronchus, and recognized a polypoid lesion. Transbronchial tumor biopsy specimens revealed squamous cell lung carcinoma. A right upper lobectomy and drainage of the hilar and mediastinal lymph regions were performed. Histopathological examination revealed the coexistence of squamous cell carcinoma with many non-caseating epithelioid cell granulomas in all hilar and mediastinal drainage lymph nodes, but no metastasis. Non-caseating epithelioid cell granulomas were also seen in the lung interstitium. Histopathological examination suggested that the squamous cell carcinoma originated from a solitary bronchial papilloma. A diagnosis of lung cancer complicated with sarcoidosis was difficult by clinical imaging alone, including FDG-PET/CT. This suggests the importance of bronchoscopic examination, if a clinical course of the disease appears to be different from the usual course. This was a rare case of squamous cell carcinoma which originated from a solitary bronchial papilloma.
Nihon Kokyūki Gakkai zasshi = the journal of the Japanese Respiratory Society. 11/2010; 48(11):815-20.
[Show abstract][Hide abstract] ABSTRACT: DNA methylation plays a vital role in the regulation of gene expression. Abnormal promoter hypermethylation is an important mechanism of inactivating tumor suppressor genes in human cancers. Combined bisulfite restriction analysis (COBRA) is a widely used method for identifying the DNA methylation of specific CpG sites. Here, we report that exonuclease I and heat-labile alkaline phosphatase can be used for PCR purification for COBRA, improving the visibility of gel electrophoresis after restriction digestion. This improvement is observed when restriction digestion is performed at a high temperature, such as 60 degrees C or 65 degrees C, with BstUI and TaqI, respectively. This simple method can be applied instead of DNA purification using spin columns or phenol/chloroform extraction. It can also be applied to other situations when PCR products are digested by thermophile-derived restriction enzymes, such as PCR restriction fragment length polymorphism (RFLP) analysis.
Biochemical and Biophysical Research Communications 08/2010; 399(3):422-4. · 2.28 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We recently identified that DNA methylation of the G0S2 gene was significantly more frequent in squamous lung cancer than in non-squamous lung cancer. However, the significance of G0S2 methylation levels on cancer cells is not yet known. We investigated the effect of G0S2 methylation levels on cell growth, mRNA expression, and chromatin structure using squamous lung cancer cell lines and normal human bronchial epithelial cells. DNA methylation and mRNA expression of G0S2 were inversely correlated, and in one of the squamous lung cancer cell lines, LC-1 sq, G0S2 was completely methylated and suppressed. Overexpression of G0S2 in LC-1 sq did not show growth arrest or apoptosis. The G0S2 gene has been reported to be a target gene of all-trans retinoic acid and peroxisome proliferator-activated receptor agonists. We treated LC-1 sq with 5-Aza-2'-deoxycytidine, Trichostatin A, all-trans retinoic acid, Wy 14643, or Pioglitazone either alone or in combination. Only 5-Aza-2'-deoxycytidine restored mRNA expression of G0S2. Chromatin immunoprecipitation revealed that histone H3 lysine 9 was methylated regardless of DNA methylation or mRNA expression. In summary, mRNA expression of G0S2 was regulated mainly by DNA methylation in squamous lung cancer cell lines. When the G0S2 gene was methylated, nuclear receptor agonists could not restore mRNA expression of G0S2 and did not show any additive effect on mRNA expression of G0S2 even after the treatment with 5-Aza-2'-deoxycytidine.
Biochemical and Biophysical Research Communications 10/2009; 390(4):1283-7. · 2.28 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Epigenetic changes can lead to abnormal expression of genes in cancer, and several genes have been reported to have aberrant promoter DNA methylation in non-small-cell lung cancer (NSCLC). We identified aberrantly methylated genes in NSCLC by combination of in silico and experimental approaches. We first applied bioinformatics, and from microarray datasets, we selected genes with low expression and having functions related to cancer. Next, combined bisulfite restriction analysis was carried out in 10 pooled resected lung cancer tissues to screen for genes that were aberrantly methylated, and the methylation ratio (the fraction of methylated DNA in extracted DNA from a cancer tissue sample) was quantified using quantitative analysis of methylated alleles. We identified 8 methylated genes (ARPC1B, DNAH9, FLRT2, G0S2, IRS2, PKP1, SPOCK1 and UCHL1) previously unreported in NSCLC. Analyses of methylation profiles of 101 resected lung cancer tissue samples revealed quantitatively low methylation in whole, methylation ratios were almost less than 30% even in the methylated samples, and no significant correlation to prognosis after 2 years of follow-up using hierarchical clustering. DNA methylation of G0S2 gene was significantly more frequent in squamous lung cancer (n = 18, mean of methylation ratios: 15%) compared with nonsquamous lung cancer (n = 83, mean of methylation ratios: 2.6%) (Mann-Whitney U test, p < 0.001). DNA methylation of G0S2 can be an important biomarker for squamous lung cancer.
International Journal of Cancer 10/2009; 126(8):1895-902. · 6.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Pulmonary complications occur in up to 60% of patients after hematopoietic stem cell transplantation (HSCT), causing significant morbidity and mortality. Among them, non-infectious bronchiolitis is considered a late complication in the form of bronchiolitis obliterans. We report a patient who developed non-infectious bronchiolitis within four weeks after undergoing HSCT for biphenotypic leukemia. Chest CT revealed centrilobular nodules that were reminiscent of diffuse panbronchiolitis, and lymphocytic bronchiolitis was confirmed by biopsy. Infection and bronchiolitis obliterans were ruled out, and the bronchiolitis resolved when leukemia relapsed. This case suggests that bronchiolitis may be another early, non-infectious pulmonary complication of HSCT.
Internal Medicine 02/2008; 47(1):61-4. · 0.97 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Cancer-specific gene promoter methylation has been described in many types of cancers, and various semi-quantified results have shown their usefulness. Here, we show a more sensitive and specific second-generation system for profiling the DNA methylation status. This method is based on bisulfite reaction of DNA and real-time PCR using two TaqMan MGB probes labeled with different fluorescence, followed by clustering analysis. Primers were designed with CpG-less sequences, and TaqMan MGB probes were designed to contain three or four CpG sites and to be shorter than conventional TaqMan probes. We have added new criteria for primer and probe design for further specificity. We confirmed the reliability of this system and applied it to analysis of lung cancers. Using 10 promoters, 90 primary lung cancers were clustered into six groups consisting of cases having similar smoking status and pathological findings. EGFR mutation and p16 promoter DNA methylation were exclusive, as previously reported; however, DNA methylation in other genes was unrelated to EGFR mutation. This system was also useful to distinguish double primary lung cancers from a single cancer with intrapulmonary metastasis. As above, our system has widespread availability in clinical use and biological research.
[Show abstract][Hide abstract] ABSTRACT: The field of epigenetics has made progress by the identification of the small RNA-mediated epigenetic modification. However, little is known about the key proteins. Here, we report that the human PIWI-like family is a candidate protein that is involved in the pathway responsible for chromatin remodeling. The PIWI-like family proteins, expressed as the Flag-fusion proteins, formed a bulky body and localized to the nuclear periphery. Transient transfection of PIWI-like 4 (PIWIL4), only member of the PIWI-like family that was ubiquitously expressed in human tissues, induced histone H3 lysine 9 methylation at the p16(Ink4a) (CDKN2A) locus. The elevated level of histone methylation resulted in the downregulation of the p16(Ink4a) gene. These results suggest PIWIL4 plays important roles in the chromatin-modifying pathway in human somatic cells.
Biochemical and Biophysical Research Communications 09/2007; 359(3):497-502. · 2.28 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Here we report that supplementation of a common compound betaine (1-carboxy-N,N,N-trimethylmethanaminium inner salt) enhances restriction digestion of DNA molecules being resistant to digestion despite the existence of recognition sites. A previous study reported total isostabilization of DNA was achieved in the presence of 5.2M of betaine, however, we have observed the enhancement of restriction kinetics at 0.3M of betaine, therefore, it likely provided some catalytic proficiency to restriction enzymes rather than the induction of DNA conformational changes. Betaine also enhances catalytic efficiency of PCR, and our result of restriction digestion, taken together, suggests potential application of betaine in other enzymatic reactions in an aqueous solution.
Biochemical and Biophysical Research Communications 01/2006; 337(4):1027-9. · 2.28 Impact Factor