Toshifumi Kameyama

Regulation of p27 by S-Phase Kinase-Associated Protein 2 Is Associated With Aggressiveness in Non–Small-Cell Lung Cancer

PURPOSE The F-box protein S-phase kinase-associated protein 2 (Skp2) is one of the positive regulators of the cell cycle that promote ubiquitin-mediated proteolysis of the cyclin-dependent kinase inhibitor p27. In this study, we investigated the significance of Skp2 expression in human non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS Clinicopathologic features and immunohistochemical expression of Skp2 and p27 proteins were studied in 138 patients with NSCLC. Survival analyses were performed using the Kaplan-Meier method and the Cox regression model. To analyze the role of Skp2 in vitro, NSCLC cells were transfected with an Skp2-expressing vector or small interfering RNA. RESULTS Skp2 was overexpressed in males, smokers, patients with squamous cell carcinomas, and patients with poorly differentiated cancers (P = .034, < .0001, < .0001, and .002, respectively). The multivariant analysis revealed that Skp2 expression is an independent prognostic factor for survival in NSCLC. An inverse relationship of Skp2 with p27 expression was observed (P = .012), and patients with both a higher expression of Skp2 and a lower expression of p27 showed a significantly unfavorable prognosis (P = .0002). In vitro ectopic expression of Skp2 in NSCLC cells reduced the protein level of p27. Conversely, induction of Skp2 siRNA increased the protein level of p27, leading to growth inhibition in NSCLC cells. CONCLUSION Skp2 overexpression is closely associated with the suppression of p27 and the aggressiveness in NSCLC. It also could be a therapeutic target in NSCLC.

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.

Overexpression of jun activation domain-binding protein 1 in nonsmall cell lung cancer and its significance in p27 expression and clinical features

Decreased expression of p27, which is an inhibitor of cyclin‐dependent kinase, is associated with cancer aggressiveness. It is believed that Jun activation domain‐binding protein 1 (Jab1) plays a role in p27 degradation in a manner that is independent from the role played by S‐phase kinase‐associated protein 2 (Skp2). To examine the clinical significance of Jab1 in nonsmall cell lung cancer (NSCLC), the protein expression of Jab1 in tumor tissues was investigated with regard to the expression of p27 and Skp2.

Blockage of the macrophage migration inhibitory factor expression by short interference RNA inhibited the rejection of an allogeneic tracheal graft

We investigated the inhibitory effect of blocking the macrophage migration inhibitory factor (MIF) on the fibrous obstruction of a transplanted allograft in a murine model of obstructive bronchiolitis (OB). Tracheal grafts from C57BL/6 mice were transplanted into a subcutaneous pouch of BALB/c. Three days after transplantation, liposome including short interference (si) RNA for MIF was injected into the lumen of the grafts. The allografts were then harvested 7, 14 or 28 days after transplantation for an evaluation of the morphological changes. The MIF expression, which was ubiquitously recognized in the epithelium of allografts, decreased after the in vivo transfection of MIF siRNA. OB formation was therefore inhibited significantly more by the treatment with MIF siRNA than the allografts injected with empty liposome on the 14th day, however, no difference was observed between them on the 28th day. Treatment with MIF siRNA inhibits the destruction of tracheal allografts and OB formation in the early phase, and MIF was thus found to be one of the major cytokines involved in the rejection of the allogeneic trachea.

Elective video-assisted thoracoscopic lung biopsy for interstitial lung disease.

Lung biopsy is often required for the definitive subtype classification of interstitial lung disease. The video-assisted thoracoscopic approach has been advocated as an alternative to standard open lung biopsy because it is less invasive; however, whether it makes a positive contribution to treatment strategy remains contentious. We investigated the safety and efficacy of the video-assisted approach in a retrospective review of 30 consecutive patients who underwent the procedure in an elective setting after being diagnosed with interstitial lung disease by chest radiography and computed tomography. The mean age of the patients was 56.7 years. The preoperative vital capacity and forced expiratory volume in 1 second were 80.0% and 83.6%, respectively. There was no operative mortality, but 2 cases of respiratory failure and 1 of prolonged air leak occurred. The diagnostic yield was 100%, and treatment was changed in 57% of the cases as a result of the histological diagnosis. The rate of treatment change was higher for patients with nonspecific interstitial pneumonia than for those with idiopathic pulmonary fibrosis. We conclude that video-assisted biopsy is effective in the subtyping of interstitial lung disease and is a safe procedure when performed electively at the early stage of the disease.

Operative results of clinical stage I non-small cell lung cancer

BACKGROUND Clinical stage (c-stage) I non-small cell lung cancer (NSCLC) is generally indicated for surgery, however, surgical exploration sometimes reveals advanced disease, thus resulting in incomplete resection. PATIENTS AND METHODS A total of 645 consecutive patients were investigated in which 347 were diagnosed to have c-stage IA in 347 and 298 were diagnosed to have IB disease. All cases underwent operation and were investigated for resectability and the cause of an incomplete resection. RESULTS The c-Stage IA patients included 16.6% of T3/4 and 10.4% of N2 whereas clinical stage IB patients included 14.4% of T3/4 and 18.8% of N2/3. A complete resection was performed in 594 patients (91%). In 347 c-stage IA patients, the complete resection rates were 93% in adenocarcinomas (235/252), 100% in squamous cell carcinomas (76/76), and 89% in others (17/19). In 298 c-stage IB patients, the complete resection rates were 86% in adenocarcinomas (141/164), 90% in squamous cell carcinomas (90/100), and 94% in others (31/33). The 5-year survival rates of the c-stage IA and IB patients who underwent a complete resection were 66.4 and 48.3%, respectively. However, the same rates were 18.4 and 14.7% for c-stage IA and IB patients who underwent an incomplete resection. The reasons for an incomplete resection in 54 patients were malignant pleurisy in 38 (70.4%), extranodal invasion of mediastinal nodal metastasis in ten (19%), an incomplete bronchial margin in three (5.6%), and ipsilateral pulmonary metastases in two (3.7%), and ipsilateral adrenal metastasis in one (1.3%). In 13% of the c-stage IB adenocarcinomas, pleural metastasis was discovered during thoracotomy. CONCLUSIONS Pleural dissemination was the most frequent cause of an incomplete resection, and its prevalence was high in c-stage IB adenocarcinomas.

Intrapleural Hypotonic Cisplatin Treatment for Malignant Pleural Mesothelioma : In Vitro Experiments and Clinical Application

PurposeWe studied the inhibitory effects of hypotonic cisplatin on the growth of malignant pleural mesothelioma (MPM) cell lines in vitro, and assessed the effectiveness of intraoperative intrapleural hypotonic cisplatin treatment combined with extrapleural pneumonectomy for patients with this tumor.MethodsIn the in vitro experiments, mesothelioma cell lines were exposed to various concentrations of cisplatin in either saline solution or distilled water for up to 5 min. After 48 h incubation, we calculated the inhibition of cell growth. In the clinical study, five patients with MPM underwent intraoperative intrapleural hypotonic cisplatin treatment combined with extrapleural pneumonectomy.ResultsThe hypotonic cisplatin treatment inhibited cell growth at a significantly greater rate than the isotonic cisplatin treatment. Just 1–5 min exposure to 10 µg/ml of hypotonic cisplatin inhibited growth by more than 80%. Clinically, no recurrence was found in four of the five patients after a median follow-up period of 27 months (range: 16–36 months), although contralateral multiple pulmonary metastases were found in one patient 10 months after surgery.ConclusionHypotonic cisplatin treatment is effective against MPM, and should be investigated further.

Operative Results of Non-small Cell Lung Cancer Clinically Presenting Mediastinal Lymph Adenopathy

OBJECTIVE Selection of treatment for operable N2 non-small cell lung cancer (NSCLC) is still controversial. If considered resectable, we have actively performed surgery even for clinical stage IIIA-N2 disease. In this retrospective study, surgical results in NSCLC with clinically presenting mediastinal lymph adenopathy examined to investigate its indication. METHODS Consecutive 202 patients who were preoperatively diagnosed or suspected of mediastinal lymph adenopathy and underwent operation were investigated for such as pathological judgement of nodal metastasis, completeness of operation and prognosis. Perioperative chemotherapy and/or radiotherapy was performed in 56 patients. RESULTS Pathological diagnosis of nodal status was N0 in 64 patients, N1 in 27, N2 in 104 and N3 in 7. Complete resection was performed in 109 patients (54%). In 111 patients with pathologically proven N2 (pN2), only 40 (36%) were completely resected. The reason of incomplete resection included extranodal extension of mediastinal nodal metastasis in 31 patients, pleural dissemination in 18, extension of primary tumor to mediastinum in 11. Median post-operative survival time was 553 days, and survival rates at 2- and 5-years were 43% and 22%, respectively. In all pN2, survival rates at 2- and 5-years were 33% and 11%, respectively. In 40 patients of completely resected pN2, survival rates at 2- and 5-years were 42% and 22%, respectively, whereas those were 17% and 5% in 64 patients with incompletely resected pN2. The positive effect of perioperative treatment on survival was not apparent. CONCLUSIONS If resectable, surgical approach to N2 might be approved, however, extensive examination is required prior to therapy to avoid incomplete resection.