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author:("Soh, yuichi")
1.  Targeting the miR-200c/LIN28B axis in acquired EGFR-TKI resistance non-small cell lung cancer cells harboring EMT features 
Scientific Reports  2017;7:40847.
MicroRNA (miR)-200 family members (miR-200s) are frequently silenced in advanced cancer and have been implicated in the process of epithelial-to-mesenchymal transition (EMT). We previously reported that miR-200s were silenced through promoter methylation in acquired EGFR-tyrosine kinase inhibitor (TKI) resistant non-small cell lung cancer (NSCLC) cells harboring EMT features. In this study, we examined the functional role of miR-200s in NSCLC cells and investigated a novel approach to overcoming acquired EGFR-TKI resistance. In the analysis of NSCLC cell lines, each of the miR-200s expression-silenced cell lines showed promoter methylation. Significant correlations between miR-200c silencing and several oncogenic pathway alterations, including EMT-changes and LIN28B overexpression, were observed in the database analysis. In addition, EGFR-wild type cell lines had lower miR-200s expression levels than EGFR-mutant cell lines. The introduction of miR-200c using pre-miR-200c caused LIN28B suppression in cells with acquired EGFR-TKI resistance that harbored EMT features. Interestingly, both the introduction of miR-200c and the knockdown of LIN28B produced an antitumor effect in acquired EGFR-TKI resistance cells, whereas these manipulations were not effective in parental cells. The miR-200c/LIN28B axis plays an important role in cells with acquired resistance to EGFR-TKI that harbor EMT features and might be a useful therapeutic target for overcoming resistance.
PMCID: PMC5233972  PMID: 28084458
2.  Interaction of cytokeratin 19 head domain and HER2 in the cytoplasm leads to activation of HER2-Erk pathway 
Scientific Reports  2016;6:39557.
HER2 is a receptor tyrosine kinase and its upregulation via activating mutations or amplification has been identified in some malignant tumors, including lung cancers. Because HER2 can be a therapeutic target in HER2-driven malignancies, it is important to understand the molecular mechanisms of HER2 activation. In the current study, we identified that cytokeratin 19 (KRT19) binds to HER2 at the inside face of plasma membrane. HER2 and KRT19, which were concurrently introduced to a human embryonic kidney 293 T cells, revealed an association with each other and resulted in phosphorylation of HER2 with the subsequent activation of a downstream Erk-associated pathway. A binding assay revealed that both the NH2-terminal head domain of KRT19 and the COOH-terminal domain of HER2 were essential for their binding. To investigate the impact of the interaction between HER2 and KRT19 in lung cancer, we examined their expressions and localizations in lung cancers. We found that KRT19 was highly expressed in HER2-positive lung cancer cells, and KRT19 and HER2 were co-localized at the cell membrane. In conclusion, we found that KRT19 intracellularly binds to HER2, playing a critical role in HER2 activation.
PMCID: PMC5180104  PMID: 28008968
3.  Randomized feasibility study of S-1 for adjuvant chemotherapy in completely resected Stage IA non–small-cell lung cancer: results of the Setouchi Lung Cancer Group Study 0701 
The feasibility of the S-1 administration schedules (the 4-week versus the 2-week) showed no significant difference for adjuvant chemotherapy among pathological-Stage IA non–small-cell lung cancer patients.
The aim of this multicenter study was to determine the appropriate administration schedule for S-1, an oral fluoropyrimidine, for adjuvant chemotherapy in patients with completely resected pathological-Stage IA (tumor diameter, 2–3 cm) non–small-cell lung cancer.
Patients were randomly assigned to receive adjuvant chemotherapy consisting of either the 4-week oral administration of S-1 (80–120 mg/body/day) followed by a 2-week rest (Group A), or the 2-week oral administration of S-1 (80–120 mg/body/day) followed by a 1-week rest (Group B). The duration of adjuvant chemotherapy was 1 year in both arms. The primary endpoint was compliance, namely drug discontinuation-free survival, which was calculated using the Kaplan–Meier method with log-rank test.
Eighty patients were enrolled in this study, and 76 patients actually received S-1 treatment. The drug discontinuation-free survival rates at 1 year were 49.1% in Group A and 52.7% in Group B (P = 0.373). The means of the relative dose intensities were 55.3% in Group A and 64.6% in Group B (P = 0.237). There were no treatment-related deaths. Patients with grade 3/4 toxicities were significantly more frequent in Group A (40.5%) than in Group B (15.4%, P = 0.021). The 2-year relapse-free survival rates were 97.5% in Group A and 92.5% in Group B, and the 2-year overall survival rates were 100% in both groups.
The feasibility showed no significant difference between the two groups among patients with completely resected Stage IA (tumor diameter, 2–3 cm) non–small-cell lung cancer.
PMCID: PMC5025397  PMID: 27207886
clinical trials; non–small-cell lung cancer; adjuvant chemotherapy; S-1
4.  The proliferative effects of asbestos-exposed peripheral blood mononuclear cells on mesothelial cells 
Oncology Letters  2016;11(5):3308-3316.
Malignant mesothelioma (MM) is thought to arise from the direct effect of asbestos on mesothelial cells. However, MM takes a long time to develop following exposure to asbestos, which suggests that the effects of asbestos are complex. The present study examined the effects of asbestos exposure on the cell growth of MeT-5A human mesothelial cells via cytokines produced by immune cells. Peripheral blood mononuclear cells (PBMCs) were stimulated with antibodies against cluster of differentiation (CD)3 and CD28 upon exposure to the asbestos chrysotile A (CA) or crocidolite (CR); the growth of MeT-5A cells in media supplemented with PBMC culture supernatants was subsequently examined. MeT-5A cells exhibited an increase in proliferation when grown in supernatant from the 7-day PBMC culture exposed to CA or CR. Analysis of cytokine production demonstrated increased levels of granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-1α, IL-1β, IL-3, IL-5, IL-13 and IL-17A in supernatants. Individual administration of these cytokines, excluding G-CSF and GM-CSF, led to an increase in cell growth of MeT-5A, whereas this effect was not observed following the combined administration of these cytokines. The results indicate that cytokines secreted by immune cells upon exposure to asbestos cause an increase in the growth activity of mesothelial cells, suggesting that alterations in the production of cytokines by immune cells may contribute to tumorigenesis in individuals exposed to asbestos.
PMCID: PMC4840842  PMID: 27123108
asbestos; mesothelial cells; mesothelioma; peripheral blood mononuclear cells; T-cell; Th2 cytokines
5.  Antitumor effect of afatinib, as a human epidermal growth factor receptor 2‐targeted therapy, in lung cancers harboring HER2 oncogene alterations 
Cancer Science  2015;107(1):45-52.
Human epidermal growth factor receptor 2 (HER2) is a member of the HER family of proteins containing four receptor tyrosine kinases. It plays an important role in the pathogenesis of certain human cancers. In non‐small‐cell lung cancer (NSCLC), HER2 amplification or mutations have been reported. However, little is known about the benefit of HER2‐targeted therapy for NSCLCs harboring HER2 alterations. In this study, we investigated the antitumor effect of afatinib, an irreversible epidermal growth factor receptor (EGFR)–HER2 dual inhibitor, in lung cancers harboring HER2 oncogene alterations, including novel HER2 mutations in the transmembrane domain, which we recently identified. Normal bronchial epithelial cells, BEAS‐2B, ectopically overexpressing wild‐type HER2 or mutants (A775insYVMA, G776VC, G776LC, P780insGSP, V659E, and G660D) showed constitutive autophosphorylation of HER2 and activation of downstream signaling. They were sensitive to afatinib, but insensitive to gefitinib. Furthermore, we examined the antitumor activity of afatinib and gefitinib in several NSCLC cell lines, and investigated the association between their genetic alterations and sensitivity to afatinib treatment. In HER2‐altered NSCLC cells (H2170, Calu‐3, and H1781), afatinib downregulated the phosphorylation of HER2 and EGFR as well as their downstream signaling, and induced an antiproliferative effect through G1 arrest and apoptotic cell death. In contrast, HER2‐ or EGFR‐non‐dependent NSCLC cells were insensitive to afatinib. In addition, these effects were confirmed in vivo by using a xenograft mouse model of HER2‐altered lung cancer cells. Our results suggest that afatinib is a therapeutic option as a HER2‐targeted therapy for NSCLC harboring HER2 amplification or mutations.
PMCID: PMC4724821  PMID: 26545934
Afatinib; ERBB2; HER2; HER2‐targeted therapy; non‐small‐cell lung cancer
6.  Genetic alterations in lung adenocarcinoma with a micropapillary component 
Molecular and Clinical Oncology  2015;4(2):195-200.
Pulmonary adenocarcinoma (PA) with a micropapillary component (PA-MPC) is known as an aggressive subtype of PA. The molecular profiles of PA-MPC have not been well characterized. the pathological reports of patients who underwent surgical resection for lung cancer between April, 2004 and May, 2012 were reviewed. Of the 674 patients diagnosed with PA, 28 were found to have MPC. A total of 138 resected PAs without MPC were selected in the same period to serve as age-, gender- and smoking status-matched controls to the PA-MPC group. Mutational status was determined by the following two methods: SNaPshot assay based on multiplex polymerase chain reaction (PCR), primer extension and capillary electrophoresis that was designed to assess 38 somatic mutations in 8 genes [AKT1, BRAF, endothelial growth factor receptor (EGFR), Kirsten rat sarcoma viral oncogene homolog (KRAS), mitogen-activated protein kinase kinase 1, neuroblastoma RAS viral oncogene homolog, phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit α (PIK3CA) and phosphatase and tensin homolog]; and a PCR-based sizing assay that assesses EGFR exon 19 (deletions), EGFR exon 20 (insertions) and human epidermal growth factor receptor 2 exon 20 (insertions). echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase fusion gene (EML4-ALK) was screened by ALK immunohistochemistry and confirmed using the reverse transcription PCR assay and the break-apart fluorescence in situ hybridization assay. Regarding genetic alterations, 13 (46.4%) of the 28 PA-MPCs harbored mutually exclusive mutations: 9 (32.1%) EGFR mutations, 1 (3.6%) KRAS mutation and 3 (10.7%) EML4-ALK fusion genes. PAs without MPC harbored 42 (30.4%) EGFR mutations, 17 (12.3%) KRAS mutations, 3 (2.2%) EML4-ALK fusion genes and 1 (0.7%) PIK3CA mutation. EML4-ALK fusion genes appeared to occur significantly more frequently in PA-MPCs compared with PAs without MPC (P=0.027). Although the sample size was small, our study suggests that the molecular pathogenesis of PA-MPC may be different from that of other adenocarcinomas.
PMCID: PMC4734214  PMID: 26893860
micropapillary adenocarcinoma; lung cancer; endothelial growth factor receptor gene; Kirsten rat sarcoma viral oncogene homolog; echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase fusion gene
7.  Establishment and molecular characterization of cell lines from Japanese patients with malignant pleural mesothelioma 
Oncology Letters  2015;11(1):705-712.
Malignant pleural mesothelioma (MPM) is an aggressive disease that is resistant to conventional therapies. Cell lines are useful models for studying the biological characteristics of tumors; therefore, the establishment of MPM cell lines is valuable for exploring novel therapeutic strategies for MPM. In the present study, 4 MPM cell lines (YUMC8, YUMC44, YUMC63, and YUMC64) were established, which consisted of 2 epithelioid and 2 sarcomatoid mesothelioma histological subtypes, from Japanese patients with MPM. The DNA methylation status, mutations, copy number gains, protein expression of representative genes, and the sensitivity to several drugs were examined in these 4 cell lines. Methylation of P16 was demonstrated in 3/4 cell lines, in which the protein expression of p16 was lost. Methylation of RASSF1A was observed in 3/4 cell lines. Copy number gains of EGFR, HER2 or MET were not detected in the 4 cell lines. Mutations in various genes, including EGFR, KRAS, HER2, BRAF, and PIK3CA, which are frequently detected in non-small cell lung cancer, were not detected in the 4 cell lines. microRNA-34b/c is a direct transcriptional target of p53 and is often silenced in MPM by promoter methylation. In the present study, miR-34b/c was heavily methylated in 2/4 established MPM cell lines. For cell adhesion molecules, E-cadherin expression was detected in the 2 epithelioid MPM cell lines, whereas N-cadherin expression was detected in all 4 established cell lines by western blotting. Vimentin was strongly expressed in the 2 sarcomatoid MPM cell lines. None of the established MPM cell lines demonstrated significant responses to the drugs tested, including NVP-AUY922, 17-DMAG, Trichostatin A, and Vorinostat. Although novel molecular findings were not observed in the current characterization of these MPM cell lines, these lines will be useful for future extensive analyses of the biological behavior of MPM and the development of novel therapeutic strategies.
PMCID: PMC4727208  PMID: 26870271
malignant pleural mesothelioma; cell line; methylation; deletion; drug sensitivity
8.  Acquisition of cancer stem cell-like properties in non-small cell lung cancer with acquired resistance to afatinib 
Cancer Science  2015;106(10):1377-1384.
Afatinib is an irreversible epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) that is known to be effective against the EGFR T790M variant, which accounts for half of the mechanisms of acquired resistance to reversible EGFR-TKIs. However, acquired resistance to afatinib was also observed in clinical use. Thus, elucidating and overcoming the mechanisms of resistance are important issues in the treatment of non-small cell lung cancer. In this study, we established various afatinib-resistant cell lines and investigated the resistance mechanisms. EGFR T790M mutations were not detected using direct sequencing in established resistant cells. Several afatinib-resistant cell lines displayed MET amplification, and these cells were sensitive to the combination of afatinib plus crizotinib. As a further investigation, a cell line that acquired resistance to afatinib plus crizotinib, HCC827-ACR, was established from one of the MET amplified-cell lines. Several afatinib-resistant cell lines including HCC827-ACR displayed epithelial-to-mesenchymal transition (EMT) features and epigenetic silencing of miR-200c, which is a suppresser of EMT. In addition, these cell lines also exhibited overexpression of ALDH1A1 and ABCB1, which are putative stem cell markers, and resistance to docetaxel. In conclusion, we established afatinib-resistant cells and found that MET amplification, EMT, and stem cell-like features are observed in cells with acquired resistance to EGFR-TKIs. This finding may provide clues to overcoming resistance to EGFR-TKIs.
PMCID: PMC4638008  PMID: 26202045
Afatinib; cancer stem cells; drug resistance; EGFR-TKI; non-small cell lung cancer
9.  Primary pulmonary melanoma: a report of two cases 
Malignant melanoma is a refractory malignancy with a dismal prognosis. It generally arises from the skin in most cases, and cases of primary pulmonary malignant melanoma are rare and often behave aggressively. We have treated two cases of localized primary pulmonary malignant melanoma using surgical resection. Pulmonary malignant melanomas often metastasize to the brain and liver; one of our cases exhibited metastasis to the cecum at about 8 months after surgery. Because cutaneous melanomas often carry activating mutations in the BRAF gene (V600E), we performed a BRAF mutational analysis using direct sequencing for both of these tumors arising from the lung. However, no BRAF mutations were detected. We detected a p53 mutation, which was thought to be a potential somatic mutation, in one of the two cases using a sequencing panel targeting 20 lung cancer-related genes. Although we also checked the expression of programmed death ligand 1 (PD-L1) on the surface of the tumor cells by immunohistochemical testing, neither of our two cases expressed PD-L1. Further molecular analyses may uncover the characteristics of primary pulmonary malignant melanomas.
PMCID: PMC4573480  PMID: 26376781
Primary pulmonary malignant melanoma; Target sequencing; Surgical resection
10.  DNA copy number gains in malignant pleural mesothelioma 
Oncology Letters  2015;10(5):3274-3278.
Malignant pleural mesothelioma (MPM) is a highly aggressive tumor with an extremely poor prognosis. The incidence of MPM is increasing as a result of widespread exposure to asbestos. The molecular pathogenesis of MPM remains unclear. The present study analyzed the frequency of various genomic copy number gains (CNGs) in MPM using reverse transcription-quantitative polymerase chain reaction. A total of 83 primary MPMs and 53 primary lung adenocarcinomas were analyzed to compare the CNGs of EGFR, KRAS, MET, FGFR1 and SOX2. In MPM, the CNGs of EGFR, KRAS, MET, FGFR1 and SOX2 were detected in 12 (14.5%), 8 (9.6%), 5 (6.0%), 4 (4.8%) and 1 (1.2%) of the samples, respectively. In lung adenocarcinomas, the CNGs of EGFR, KRAS, MET, FGFR1 and SOX2 were detected in 21 (39.6%), 12 (22.6%), 5 (9.4%), 10 (18.9%) and 0 (0.0%) of the samples, respectively. The CNGs of EGFR, KRAS and FGFR1 were significantly less frequent in the MPMs compared with the lung adenocarcinomas (P=0.0018, 0.048 and 0.018, respectively). Overall, the MPMs exhibited these CNGs less frequently compared with the lung adenocarcinomas (P=0.0002). The differences in CNGs between the two tumor types suggested that they are genetically different.
PMCID: PMC4665758  PMID: 26722325
malignant pleural mesothelioma; lung adenocarcinoma; copy number; reverse transcription-quantitative polymerase chain reaction
12.  Acquired Resistance to EGFR Inhibitors Is Associated with a Manifestation of Stem cell–like Properties in Cancer Cells 
Cancer research  2013;73(10):3051-3061.
Acquired resistance to EGF receptor (EGFR) tyrosine kinase inhibitor (TKI) is a critical problem in the treatment of lung cancer. Although several mechanisms have been shown to be responsible for acquired resistance, all mechanisms have not been uncovered. In this study, we investigated the molecular and cellular profiles of the acquired resistant cells to EGFR-TKI in EGFR-mutant lung cancers. Four EGFR-mutant cell lines were exposed to gefitinib by stepwise escalation and high-concentration exposure methods, and resistant sublines to gefitinib were established. The molecular profiles and cellular phenotypes of these resistant sublines were characterized. Although previously reported, alterations including secondary EGFR T790M mutation, MET amplification, and appearance of epithelial-to-mesenchymal transition (EMT) features were observed, these 2 drug-exposure methods revealed different resistance mechanisms. The resistant cells with EMT features exhibited downregulation of miRNA-200c by DNA methylation. Furthermore, the HCC827-derived subline characterized by the high-concentration exposure method exhibited not only EMT features but also stem cell–like properties, including aldehyde dehydrogenase isoform 1 (ALDH1A1) overexpression, increase of side-population, and self-renewal capability. Resistant sublines with stem cell–like properties were resistant to conventional chemotherapeutic agents but equally sensitive to histone deacetylase and proteasome inhibitors, compared with their parental cells. ALDH1A1 was upregulated in clinical samples with acquired resistance to gefitinib. In conclusion, our study indicates that the manner of EGFR-TKI exposure influences the mechanism of acquired resistance and the appearance of stem cell–like property with EGFR-TKI treatment.
PMCID: PMC4506773  PMID: 23542356
13.  Ethnicity affects EGFR and KRAS gene alterations of lung adenocarcinoma 
Oncology Letters  2015;10(3):1775-1782.
Mutations or copy number gains (CNGs) of the EGFR and KRAS genes are representative alterations in lung adenocarcinomas that are individually associated with patient characteristics such as ethnicity, smoking status and gender. However, the effects of combinations of these genetic alterations have not been statistically examined. The present study analyzed previously examined lung adenocarcinoma cases in Asian (n=166) and non-Asian (n=136) individuals in whom all four EGFR and KRAS alterations had been studied. The polynomial logistic regression models were used following adjustment for gender and smoking status, and using patients without any type of EGFR/KRAS alterations as a reference. Between the two ethnic groups, EGFR CNGs (gEGFR) occurred more frequently than EGFR mutations (mEGFR) (46 vs. 38% in Asians; 21 vs. 10% in non-Asians), whereas KRAS mutations (mKRAS) were more frequent than KRAS CNGs (gKRAS) (13 vs. 7% and 35 vs. 4%, respectively). Additionally, gEGFR and gKRAS occurred significantly more frequently in respective mutant cases, and all EGFR alterations were almost exclusive of all KRAS alterations. The polynomial logistic regression models confirmed that all types of EGFR alterations were significantly more frequent among Asian individuals than among non-Asian individuals, independent of gender and smoking status (odds ratios, 2.36–6.67). KRAS alterations occurred less frequently among Asian individuals than among non-Asian individuals, although a significant difference was not detected. The present study results indicated that the EGFR and KRAS profiles, including mutations and CNGs, differ between Asian and non-Asian individuals with lung adenocarcinoma, suggesting that ethnicity strongly affects the molecular characteristics of lung adenocarcinoma.
PMCID: PMC4533243  PMID: 26622749
lung adenocarcinoma; EGFR; KRAS; mutation; copy number gain; ethnicity
14.  TAE226, a Bis-Anilino Pyrimidine Compound, Inhibits the EGFR-Mutant Kinase Including T790M Mutant to Show Anti-Tumor Effect on EGFR-Mutant Non-Small Cell Lung Cancer Cells 
PLoS ONE  2015;10(6):e0129838.
TAE226, a bis-anilino pyrimidine compound, has been developed as an inhibitor of focal adhesion kinase (FAK) and insulin-like growth factor-I receptor (IGF-IR). In this study, we investigated the effect of TAE226 on non-small-cell lung cancer (NSCLC), especially focusing on the EGFR mutational status. TAE226 was more effective against cells with mutant EGFR, including the T790M mutant, than against cells with wild-type one. TAE226 preferentially inhibited phospho-EGFR and its downstream signaling mediators in the cells with mutant EGFR than in those with wild-type one. Phosphorylation of FAK and IGF-IR was not inhibited at the concentration at which the proliferation of EGFR-mutant cells was inhibited. Results of the in vitro binding assay indicated significant differences in the affinity for TAE226 between the wild-type and L858R (or delE746_A750) mutant, and the reduced affinity of ATP to the L858R (or delE746_A750) mutant resulted in good responsiveness of the L858R (or delE746_A750) mutant cells to TAE226. Of interest, the L858R/T790M or delE746_A750/T790M mutant enhanced the binding affinity for TAE226 compared with the L858R or delE746_A750 mutant, resulting in the effectiveness of TAE226 against T790M mutant cells despite the T790M mutation restoring the ATP affinity for the mutant EGFR close to that for the wild-type. TAE226 also showed higher affinity of about 15-fold for the L858R/T790M mutant than for the wild-type one by kinetic interaction analysis. The anti-tumor effect against EGFR-mutant tumors including T790M mutation was confirmed in mouse models without any significant toxicity. In summary, we showed that TAE226 inhibited the activation of mutant EGFR and exhibited anti-proliferative activity against NSCLCs carrying EGFR mutations, including T790M mutation.
PMCID: PMC4474554  PMID: 26090892
15.  Lower lobe origin is a poor prognostic factor in locally advanced non-small-cell lung cancer patients treated with induction chemoradiotherapy 
Molecular and Clinical Oncology  2015;3(3):706-712.
The AIM of this study was to identify prognostic factors in patients receiving trimodality therapy for locally advanced non-small-cell lung cancer (NSCLC). Among patients who underwent induction chemoradiotherapy (CRT) followed by surgery between 1999 and 2011 at our institution, 76 NSCLC patients with clinical (c) N2/3 stage III were enrolled in this retrospective study. Induction CRT consisted of docetaxel and cisplatin with concurrent 40–60 Gy radiation therapy. In total, 76 patients were assessed (53 men and 23 women) with 43 adenocarcinomas and 33 non-adenocarcinomas. Of the 76 patients, 44 had cStage IIIA and 32 had cStage IIIB disease. The primary tumors were located in the right upper lobe (N=33), right middle lobe (N=5), right lower lobe (N=11), left upper lobe (N=20s) and left lower lobe (N=7). For all 76 patients, lower lobe tumors were associated with a significantly shorter overall survival (OS) and disease-free survival (DFS) compared to non-lower lobe tumors (OS, P=0.022; and DFS, P=0.0007). When the analysis was limited to pathologically proven N2/3 disease prior to induction CRT (n=36), lower lobe location, compared to other locations, tended to be a poor prognostic factor (OS, P=0.068; and DFS, P=0.0075). Our results indicated that a lower lobe tumor origin is associated with unfavorable prognosis in NSCLC patients treated with induction CRT, strongly suggesting the significance of appropriate patient selection in order to maximize the benefits of trimodality therapy.
PMCID: PMC4471621  PMID: 26137291
non-small-cell lung cancer; induction chemoradiotherapy; surgery; N2 disease
16.  A Case of Carcinoma Showing Thymus-Like Differentiation with a Rapidly Lethal Course 
Case Reports in Oncology  2014;7(3):840-844.
A 55-year-old woman underwent a total thyroidectomy for carcinoma showing thymus-like differentiation (CASTLE). The patient was referred to our hospital after the tumor was found to have directly invaded the cervical esophagus and the entire circumference of the trachea. A total thyroidectomy was performed, followed by end-to-end anastomosis of the trachea, suprahyoid release and dissection of bilateral pulmonary ligaments. No major complications, including anastomotic dehiscence or stenosis, were observed. The patient experienced some swallowing disturbances and hoarseness during the perioperative period but fully recovered. Radiotherapy to the neck was performed as an adjuvant therapy. Eleven months after surgery, lower back pain and right leg numbness developed and led to gait inability. Multiple lung and bone recurrences were observed, but no local recurrence. Palliative radiotherapy to the bone metastasis was performed. The patient died of pleural metastasis 14 months after the initial diagnosis of CASTLE.
PMCID: PMC4307009  PMID: 25685135
Carcinoma showing thymus-like differentiation; Infiltrating trachea; Reconstruction
17.  CDKN2A/p16 inactivation mechanisms and their relationship to smoke exposure and molecular features in non-small cell lung cancer 
CDKN2A(p16) inactivation is common in lung cancer and occurs via homozygous deletions (HD), methylation of promoter region, or point mutations. While p16 promoter methylation has been linked to KRAS mutation and smoking, the associations between p16 inactivation mechanisms and other common genetic mutations and smoking status are still controversial or unknown.
We determined all three p16 inactivation mechanisms using multiple methodologies for genomic status, methylation, RNA and protein expression, and correlated them with EGFR, KRAS, STK11 mutations and smoking status in 40 cell lines and 45 tumor samples of primary NSCLC. We also performed meta-analyses to investigate the impact of smoke exposure on p16 inactivation.
p16 inactivation was the major mechanism of RB pathway perturbation in NSCLC, with HD being the most frequent method, followed by methylation and the rarer point mutations. Inactivating mechanisms were tightly correlated with loss of mRNA and protein expression. p16 inactivation occurred at comparable frequencies regardless of mutational status of EGFR, KRAS and STK11, however, the major inactivation mechanism of p16 varied. p16 methylation was linked to KRAS mutation but was mutually exclusive with EGFR mutation. Cell lines and tumor samples demonstrated similar results. Our meta-analyses confirmed a modest positive association between p16 promoter methylation and smoking.
Our results confirm that all of the inactivation mechanisms are truly associated with loss of gene product and identify specific associations between p16 inactivation mechanisms and other genetic changes and smoking status.
PMCID: PMC3951422  PMID: 24077454
p16; CDKN2A; inactivation; homozygous deletion; methylation; lung cancer; adenocarcinoma; meta-analysis
18.  Anti-Cancer Effects of REIC/Dkk-3-encoding Adenoviral Vector for the Treatment of Non-small Cell Lung Cancer 
PLoS ONE  2014;9(2):e87900.
REIC/Dkk-3 is down-regulated in a broad range of human cancer cells and is considered to function as a tumor suppressor. We previously reported that REIC/Dkk-3-expressing adenovirus vector (Ad-REIC) induced endoplasmic reticulum (ER) stress and cancer-specific apoptosis in human prostate cancer. In this study, we examined the therapeutic impact of Ad-REIC on non-small cell lung cancer (NSCLC).
Materials and Methods
We examined the anti-tumor effect of Ad-REIC on 25 NSCLC cell lines in vitro and A549 cells in vivo. Two of these cell lines were artificially established as EGFR-tyrosine kinase inhibitor (TKI) resistant sublines.
Ad-REIC-treatment inhibited the cell viability by 40% or more in 13 (52%) of the 25 cell lines at multiplicity of infection (MOI) of 20 (20 MOI). These cell lines were regarded as being highly sensitive cells. The cell viability of a non-malignant immortalized cell line, OUMS-24, was not inhibited at 200 MOI of Ad-REIC. The effects of Ad-REIC on EGFR-TKI resistant sublines were equivalent to those in the parental cell lines. Here, we demonstrated that Ad-REIC treatment activated c-Jun N-terminal kinase (JNK) in NSCLC cell lines, indicating the induction of ER stress with GRP78/BiP (GRP78) up-regulation and resulting in apoptosis. A single intratumoral injection of Ad-REIC significantly inhibited the tumorigenic growth of A549 cells in vivo. As predictive factors of sensitivity for Ad-REIC treatment in NSCLC, we examined the expression status of GRP78 and coxsackievirus and adenovirus receptor (CAR). We found that the combination of the GRP78 and CAR expressional statuses may be used as a predictive factor for Ad-REIC sensitivity in NSCLC cells.
Ad-REIC induced JNK activation and subsequent apoptosis in NSCLC cells. Our study indicated that Ad-REIC has therapeutic potential against NSCLC and that the expression statuses of GRP78 and CAR may predict a potential therapeutic benefit of Ad-REIC.
PMCID: PMC3912155  PMID: 24498395
19.  Novel Germline Mutation in the Transmembrane Domain of HER2 in Familial Lung Adenocarcinomas 
We encountered a family of Japanese descent in which multiple members developed lung cancer. Using whole-exome sequencing, we identified a novel germline mutation in the transmembrane domain of the human epidermal growth factor receptor 2 (HER2) gene (G660D). A novel somatic mutation (V659E) was also detected in the transmembrane domain of HER2 in one of 253 sporadic lung adenocarcinomas. Because the transmembrane domain of HER2 is considered to be responsible for the dimerization and subsequent activation of the HER family and downstream signaling pathways, we performed functional analyses of these HER2 mutants. Mutant HER2 G660D and V659E proteins were more stable than wild-type protein. Both the G660D and V659E mutants activated Akt. In addition, they activated p38, which is thought to promote cell proliferation in lung adenocarcinoma. Our findings strongly suggest that mutations in the transmembrane domain of HER2 may be oncogenic, causing hereditary and sporadic lung adenocarcinomas.
PMCID: PMC3906987  PMID: 24317180
20.  Intrathoracic irrigation with arbekacin for methicillin-resistant Staphylococcus aureus empyema following lung resection 
Empyema is a well-known complication following lung resection. In particular, empyema caused by methicillin-resistant Staphylococcus aureus (MRSA) is difficult to treat. Here, we present our experience of MRSA empyema treated with local irrigation using arbekacin.
Six patients consisted of 4 males and 2 females with an average age of 65.7 years. They developed MRSA empyema following lung resection and were treated at our institution between 2007 and 2011. Cases comprised four primary and one metastatic lung cancer, and 1 patient was a living lung transplantation donor. The surgical procedure consisted of four lobectomies, one segmentectomy and one wedge resection. After diagnosis of MRSA empyema, anti-MRSA drugs were administered intravenously in all cases. In addition, arbekacin irrigation at a dose of 100 mg dissolved in saline was performed after irrigation with saline only.
The average number of postoperative days for the diagnosis of MRSA empyema was 13 (range 4–19). The period of irrigation ranged from 6 to 46 days. Arbekacin irrigation did not induce nephrotoxicity or other complications, and no bacteria resistant to arbekacin was detected in the thoracic cavity. We re-operated on 1 case because he had pulmonary fistula and severe wound infection. At the time of removing the thoracic catheter, MRSA in the pleural effusion disappeared completely in 3 patients. The period until MRSA concentration in the pleural effusion became negative after starting arbekacin irrigation ranged from 4 to 9 days. In the remaining cases, in which MRSA did not disappear, the catheter was removed because of no inflammatory reaction after stopping irrigation and clamping the catheters. All patients were discharged from our institution without thoracic catheterization and no patients had relapsed during the follow-up period ranging from 6 to 44 months.
Irrigation of the thoracic cavity with arbekacin proved to be an effective, safe and readily available method for treating MRSA empyema following lung resection.
PMCID: PMC3422970  PMID: 22718464
Methicillin-resistant Staphylococcus aureus; Empyema; Irrigation; Arbekacin; Lung resection
21.  Impact of aberrant methylation of microRNA-9 family members on non-small cell lung cancers 
Molecular and Clinical Oncology  2012;1(1):185-189.
MicroRNAs (miRs) contribute to cancer development and progression by acting as oncogenes and tumor suppressor genes. miR-9 family members (miR-9s), including miR-9-1, 9-2 and 9-3, have been shown to be oncogenically involved through the downregulation of E-cadherin expression, which promotes the epithelial-mesenchymal transition. Tumor suppressive roles of miR-9s have also been reported to silence miR-9 through methylation, which is associated with an shortened overall survival (OS) period in several types of cancer. In this study, the impact of miR-9s methylation on non-small cell lung cancers (NSCLC) was investigated. In total, 293 resected NSCLC samples were examined and the miR-9s methylation status was determined using a combined bisulfite restriction analysis. miR-9 expression was analyzed by in situ hybridization. Methylation of miR-9-1, 9-2 and 9-3 was present in 20 (7%), 33 (11%) and 34 (12%) of the cases, respectively. Methylation of any miR-9s (miR-9s methylation) was observed in 76 of the cases (26%), and miR-9 expression was silenced in cases with miR-9s methylation. Logistic regression analysis demonstrated that male gender [odds ratio (OR), 2.0; 95% confidence interval (95% CI), 1.1–3.6; P=0.01] and pathologically negative lymph node metastasis (OR, 4.8; 95% CI, 1.4–17.2; P=0.002) were independent relative factors for miR-9s methylation. Additionally, miR-9s methylation [hazard ratio (HR), 4.2; 95% CI, 1.2–27.0; P=0.026] and early pathological stage (HR, 8.3; 95% CI, 2.1–28.6; P=0.004) were found to be independent predictive factors for prolonged OS time by the Cox proportional hazard test. miR-9s methylation which induces expression silencing is common in NSCLC cases without lymph nodal metastasis, suggesting that miR-9s are oncogenically involved in NSCLC carcinogenesis through the promotion of tumor metastasis.
PMCID: PMC3956236  PMID: 24649145
lung cancer; non-small cell lung cancer; microRNA; miR-9; methylation; in situ hybridization
22.  Induction Chemoradiotherapy Followed by Surgical Resection for Clinical T3 or T4 Locally Advanced Non–Small Cell Lung Cancer 
Annals of Surgical Oncology  2012;19(8):2685-2692.
To examine the usefulness of trimodality therapy in patients with clinical T3 or T4 (cT3–4) locally advanced non–small cell lung cancer (LA-NSCLC).
Between 1997 and 2009, a total of 76 LA-NSCLC patients with cT3–4 underwent surgery. Among them, 36 patients underwent induction chemoradiotherapy with docetaxel and cisplatin plus concurrent radiation followed by surgery (IC group). The other 40 patients initially underwent surgery (IS group). The outcomes of the IC and IS groups were then investigated. To minimize possible biases caused by confounding treatment indications, we performed a retrospective cohort analysis by applying a propensity score (PS). Patients were divided into three groups according to PS tertiles, and comparisons between the IC and IS groups were made by PS tertile-stratified Cox proportional hazard models.
For the entire cohort, which had a median follow-up duration of 48 months, the 3- and 5-year overall survival rates were 83.8 and 78.9%, respectively, in the IC group, versus 66.8 and 56.5%, respectively, in the IS group (P = 0.0092). After adjustments for potentially confounding variables, the IC group continued to have a significantly longer overall survival than the IS group (P = 0.0045). In addition, when the analysis was limited to 52 patients with cT3–4N0 or N1 disease, the IC group had a significantly longer overall survival than the IS group after adjustments for confounding variables (P = 0.019).
Our study indicates that trimodality therapy is highly effective in patients with cT3–4 LA-NSCLC.
Electronic supplementary material
The online version of this article (doi:10.1245/s10434-012-2302-x) contains supplementary material, which is available to authorized users.
PMCID: PMC3404289  PMID: 22396006
23.  Knockdown of Oncogenic KRAS in Non-Small Cell Lung Cancers Suppresses Tumor Growth and Sensitizes Tumor Cells to Targeted Therapy 
Molecular cancer therapeutics  2011;10(2):336-346.
Oncogenic KRAS is found in >25% of lung adenocarcinomas, the major histologic subtype of non-small cell lung cancer (NSCLC), and is an important target for drug development. To this end, we generated four NSCLC lines with stable knockdown selective for oncogenic KRAS. As expected, stable knockdown of oncogenic KRAS led to inhibition of in vitro and in vivo tumor growth in the KRAS mutant NSCLC cells, but not in NSCLC cells that have wild-type KRAS (but mutant NRAS). Surprisingly, we did not see large-scale induction of cell death and the growth inhibitory effect was not complete. To further understand the ability of NSCLCs to grow despite selective removal of mutant KRAS expression, we performed microarray expression profiling of NSCLC cell lines with or without mutant KRAS knockdown and isogenic human bronchial epithelial cell lines (HBECs) with and without oncogenic KRAS. We found that while the MAPK pathway is significantly down-regulated after mutant KRAS knockdown, these NSCLCs showed increased levels of phospho-STAT3 and phospho-EGFR, and variable changes in phospho-Akt. In addition, mutant KRAS knockdown sensitized the NSCLCs to p38 and EGFR inhibitors. Our findings suggest that targeting oncogenic KRAS by itself will not be sufficient treatment but may offer possibilities of combining anti-KRAS strategies with other targeted drugs.
PMCID: PMC3061393  PMID: 21306997
24.  DNA methylation status of REIC/Dkk-3 gene in human malignancies 
The 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.
PMCID: PMC3325424  PMID: 22274868
DNA methylation; REIC/Dkk-3; Breast cancer; Lung cancer; Mesothelioma
25.  Presence of EGFR mutation in pathologically non-malignant specimens from computed tomography-guided lung needle biopsies 
Oncology Letters  2011;3(2):401-404.
Activating mutations of the epidermal growth factor receptor (EGFR) gene are characteristic of non-small cell lung cancer (NSCLC). EGFR mutations were previously detected in histologically normal lung tissue around NSCLC tumors. Computed tomography-guided lung needle biopsy (CTNB) is an accurate and useful technique for the diagnosis of lung tumors. However, pathologically non-malignant cases occasionally become apparent following lung tumor resection. In this study, we determined the EGFR mutational status of lung tumors diagnosed as non-malignant in CTNB specimens, but diagnosed as NSCLC following surgical resection. Between 2000 and 2008, 1,109 CTNBs were performed at Okayama University Hospital. Among them, 15 cases were initially diagnosed as non-malignant by CTNB, but diagnosed as NSCLC following surgical resection as a result of a high likelihood of malignancy by clinical findings. Twelve paired DNAs of CTNB and corresponding resected specimens were available to examine the EGFR mutational status using a mutant-enriched PCR assay. EGFR mutations were detected in one out of 12 CTNB specimens and three of the corresponding resected tumors. This case harbored the same EGFR mutation in the CTNB specimen and resected tumor, but not in the distant corresponding non-malignant lung tissue. Our results indicated that the detection of EGFR mutations may therefore aid the diagnosis of NSCLC in pathologically non-malignant CTNB specimens.
PMCID: PMC3362587  PMID: 22740920
non-small cell lung cancer; epidermal growth factor receptor; computed tomography-guided lung needle biopsy

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