Tomoyoshi Takenaka

Combined evaluation of Rad51 and ERCC1 expressions for sensitivity to platinum agents in non-small cell lung cancer

DNA repair enzyme expression in tumor cells possibly affects sensitivity to anti‐cancer agents. The aim of this study was to determine the relationship between expression status of DNA repair enzymes and chemosensitivity in patients with non‐small cell lung cancer (NSCLC). NSCLC tissues prepared from the surgical specimens of 41 patients were subjected to immunohistochemical analysis for Rad51 and ERCC1 proteins and to a chemosensitivity test using the MTT assay. The relationships between the expression status of the DNA repair enzymes and ex vivo chemosensitivity to various agents were evaluated. A positive expression for Rad51 and ERCC1 was observed in 17 cases (41%) and 20 cases (49%), respectively. The positivity of Rad51 was closely related to a certain histologic type of squamous cell carcinoma and poor differentiation, and the positivity of ERCC1 tended to be related to squamous cell carcinoma. In chemosensitivity tests, sensitivities to CDDP and CBDCA were significantly lower when both 2 enzymes were positive (p = 0.012 and 0.04 in CDDP, 0.014 and 0.03 in CBDCA). Both Rad51 and ERCC1 expressions showed no significant relationship with sensitivities to paclitaxel, etoposide, vinorelbine, gemcitabine, 5‐FU, or irinotecan. In conclusion, combined expression of Rad51 and ERCC1 expression is associated with resistance to platinum agents in the ex vivo study of clinical NSCLC, and evaluation of expression status of both DNA repair enzymes would be a predictor for clinical response to platinum‐based chemotherapies.

Never-smoking Nonsmall Cell Lung Cancer as a Separate Entity : Clinicopathologic Features and Survival

To propose ‘never‐smoking nonsmall cell lung cancer (NSCLC)’ as a separate entity, the clinicopathologic differences of operable NSCLC between never‐smoking patients and patients with a history of smoking were investigated.

Effects of excision repair cross-complementation group 1 (ERCC1) single nucleotide polymorphisms on the prognosis of non-small cell lung cancer patients

BACKGROUND Excision repair cross-complementation group 1 (ERCC1) is the lead enzyme in the nucleotide excision repair process. Two polymorphisms of ERCC1, T19007C (rs11615) and C8092A (rs3212986), have been reported to affect both the carcinogenesis and the survival of the patients who received platinum-based chemotherapy, but the mechanism by which these polymorphisms influence the survival is unclear. In this study, we determined the function of these ERCC1 polymorphisms in the survival of NSCLC patients. METHOD The ERCC1 T19007C and C8092A single nucleotide polymorphisms (SNPs) were evaluated in 122 Japanese non-small cell lung cancer (NSCLC) patients who underwent a complete resection and analyzed the clinicopathological significance of these SNPs. None of the patients received peri-operative platinum-based chemotherapy. The relationship between these SNPs and ERCC1 protein expression and the platinum sensitivity of the primary tumors were also examined. RESULT Regarding T19007C SNP, the distribution of the CC, CT, and TT genotypes was 45%, 48% and 7%, respectively. As for C8092A SNP, the distribution of CC and CA genotypes was 70% and 30%, respectively. The patients with C8092A CA genotype were significantly poorer disease-free survival (DFS) and overall survival (OS) than those with the CC genotype (p=0.037 and 0.004). In addition, no relationship was observed between T19007C SNP and DFS or OS. These two SNPs also did not correlate with either ERCC1 protein expression or platinum sensitivity. CONCLUSION The ERCC1 C8092A polymorphism may influence the NSCLC prognosis regardless of the ERCC1 protein expression and platinum sensitivity.

Induction of epithelial-mesenchymal transition-related genes by benzo[a]pyrene in lung cancer cells

It is believed that epithelial‐mesenchymal transition (EMT) occurs during the development and progression of cancer; however, the correlation between tobacco smoking and EMT remains to be elucidated.

Upregulation of Hypoxia-Inducible Factor-1α mRNA and its Clinical Significance in Non-small Cell Lung Cancer

Background: Hypoxia-inducible factor 1α (HIF-1α) is a transcription factor that plays an important role in tumor growth by regulating the energy metabolism and angiogenesis. We herein investigated the mRNA expression level of HIF-1α in non-small cell lung cancer (NSCLC) tissues to clarify the impact on the clinical aspects of NSCLC patients. Experimental Design: HIF-1α mRNA derived from either a tumor or an adjacent lung tissue was quantified using quantitative reverse transcription polymerase chain reaction in 66 patients with NSCLC. The relationship between the mRNA expression level of HIF-1α and clinicopathological factors was investigated. Results: The expression level of HIF-1α mRNA, which correlated with its protein level, was significantly higher in tumor tissue than in the corresponding nontumor-bearing lung tissue (4.22 × 104 ± 4.99 × 104 versus 1.24 × 104 ± 1.15 × 104; p < 0.001). The level of HIF-1α mRNA showed a significantly positive correlation with the mRNA levels of vascular endothelial growth factor and type II hexokinase in tumors (p < 0.0001 for each). In node-negative patients, high expression levels of HIF-1α mRNA in tumors were associated with a poor prognosis (p = 0.0401), but not in the node-positive cases. Conclusion: The expression of HIF-1α mRNA is associated with disease progression in NSCLC tissues, and is expected as a biomarker or therapeutic target.

Benzo[a]pyrene promotes proliferation of human lung cancer cells by accelerating the epidermal growth factor receptor signaling pathway

Smoking is an independent prognostic factor of lung adenocarcinoma. Benzo[a]pyrene (B[a]P) is one of the strongest carcinogens and it is present in both the environment and cigarette smoke. In this study, the effect of B[a]P on the proliferative activity of lung adenocarcinoma cells was investigated. A lung adenocarcinoma cell line, A549, was cultured with B[a]P for various periods, and its proliferative activity was examined by an MTS assay. To investigate the intracellular events related to the proliferative activity, the gene expression profile was investigated by a microarray analysis and a quantitative RT-PCR, and the protein expression and activation status of Akt, ERK 1/2 and the epidermal growth factor receptor (EGFR) were examined by a western blot analysis. Following the culture with B[a]P for 24 weeks, the serum-independent proliferative activity was increased. A microarray analysis revealed that a reversible upregulation of the EGFR and epiregulin genes was recognized in the B[a]P treated cells, in which the overexpression of the phosphorylated EGFR protein was also recognized. The EGFR tyrosine kinase inhibitor reduced the cellular proliferation and the level of phosphorylation of ERK1/2, which is a downstream signal of the EGFR, in the B[a]P-treated A549 cells. Moreover, the B[a]P treatment increased the mRNA expressions of the ligands for EGFR such as amphiregulin and epiregulin. B[a]P increases the proliferative potential of lung adenocarcinoma cells through the EGFR signaling pathway.

Serum carcinoembryonic antigen level is associated with epidermal growth factor receptor mutations in recurrent lung adenocarcinomas

The presence of epidermal growth factor receptor (EGFR) gene mutations is a good indicator of the clinical efficacy of gefitinib in patients with nonsmall cell lung cancer. It was recently reported that the serum carcinoembryonic antigen (CEA) level could be a predictive factor for the efficacy of gefitinib treatment; therefore, it is suggested that the EGFR gene mutation is associated with the serum CEA level. The current study analyzed the association between EGFR gene mutations and clinical features, including the serum CEA level, in patients with recurrent lung adenocarcinomas.

An extremely rare case of small-cell lung cancer harboring variant 2 of the EML4-ALK fusion gene

Anaplastic lymphoma kinase (ALK) fuses echinoderm microtubule-associated protein-like 4 (EML4) to acquire a transforming activity in lung adenocarcinomas. However, the presence of an EML4-ALK fusion gene in other lung cancer histologies is an extremely rare phenomenon. A 43-year-old female was referred to our department due to dyspnea on effort and left back pain. Computed tomography (CT) showed a large mass in the upper lobe of the left lung and a massive left pleural effusion, while a CT-guided needle biopsy confirmed a diagnosis of small-cell lung cancer (SCLC). Surprisingly, the tumor was genetically considered to harbor the EML4-ALK fusion gene (variant 2). Although the patient underwent two regimens of cytotoxic chemotherapy for SCLC, she died approximately seven months after the administration of first-line chemotherapy. Our analysis of 30 consecutive patients with SCLC for EML4-ALK revealed that two patients, including the current patient and a patient we previously reported, harbored the EML4-ALK fusion gene.

Role of surgical resection for patients with limited disease-small cell lung cancer

OBJECTIVES Although chemotherapy and radiotherapy are recommended for patients with limited disease small cell lung cancer (LD-SCLC), several series have reported favorable survival outcomes even in patients with stages II and III disease who underwent surgical resection. The purpose of this study is to compare the outcomes of the use of surgical resection to the other conventional non-surgical treatments in patients with LD-SCLC with respect to each clinical stage. MATERIALS AND METHODS We retrospectively reviewed 277 patients who received treatment for LD-SCLC and compared the outcomes of the use of surgical resection to the other conventional non-surgical treatments. RESULTS The clinical stage was stage I in 50 cases (18%), stage II in 53 cases (19%) and stage III in 174 cases (63%). Eighty-eight patients received surgical resection and 189 patients were treated with non-surgical treatment. Surgery was performed in 44 patients (88%) with stage I, 27 patients (52%) with stage II and 17 patients (10%) with stage III disease. The five-year survival rates of the patients according to clinical stage were 58% in stage I, 29% in stage II and 18% in stage III. The five-year survival rates of the patients with and without surgical resection according to clinical stage were as follows: 62% and 25% in stage I (p<0.01), 33% and 24% in stage II (p=0.95), 18% and 18% in stage III (p=0.35), respectively. In 44 propensity score-matched pairs with stages II and III disease, including matching for variables such as age, gender and the PS, the five-year survival rates was better in patients with surgical resection than in those without surgery (p=0.04). CONCLUSION Surgical resection is effective for the patients with stage I LD-SCLC and some cases of stage II or III disease.

Expression of mismatch repair proteins, hMLH1/hMSH2, in non-small cell lung cancer tissues and its clinical significance

hMLH1 and hMSH2 have been implicated to be involved in the DNA mismatch repair (MMR) system. The purpose of this study is to investigate the expression of hMLH1 and hMSH2 DNA MMR proteins in non‐small cell lung cancer (NSCLC) tissue and to elucidate their clinical significance.