[Experiences of Cardioaortic Surgery with Small Anterior Mediastinal Mass on Preoperative Computed Tomography].

Computed tomography(CT) is indispensable for diagnostic imaging. During preoperative assessment for cardioaortic surgery, a CT examination is performed not only for diagnostic purposes but also to decide the surgical strategy. In some cases, CT demonstrates a small abnormal mass in the adipose tissue of the anterior mediastinum. Sometimes radiologists diagnose the image and send the diagnostic report to cardiologists or cardiovascular surgeons. However, they tend to limit their focus to their field of specialty. Thus, they might overlook or underestimate an abnormal mass. Anterior mediastinal masses, though small, may include malignant tumors. Thus, we reviewed 12 cases in which anterior mediastinal masses were found on preoperative CT. Two of these patients were finally diagnosed with malignant tumors. We should pay attention to not only cardiovascular assessment but also mediastinal masses on preoperative CT. In some cases, concomitant surgery for cardioaortic disease and an anterior mediastinal tumor is effective.

Pembrolizumab-induced interstitial lung disease following thoracic surgery in a patient with non-small cell lung cancer.

The safety of treatment with immune-checkpoint inhibitors prior to thoracic surgery in patients with non-small cell lung cancer (NSCLC) remains unclear. Here, we describe the case of a 62-year-old woman with NSCLC with programmed death ligand 1 expression on 85% of tumor cells. The patient was initially considered to have unresectable stage IIIB disease and received pembrolizumab monotherapy. After 12 cycles of pembrolizumab, the primary tumor was reduced, but a small lung nodule in another lobe was unchanged. Based on the course of image findings, the nodule was considered to be an old inflammatory change. The clinical stage was changed to stage IB and partial resection was performed. Three days after thoracic surgery, the patient began to complain of coughing and shortness of breath. A CT of the chest revealed ground-glass opacity in the bilateral lung fields, suggesting interstitial lung disease (ILD) associated with pembrolizumab. Corticosteroid therapy was started and a chest X-ray showed a reduction in the opacity with improved oxygenation. This is the first case of immune-checkpoint inhibitor-related ILD triggered by thoracic surgery following long-term immune-checkpoint therapy.

Lobectomy for subsegmental lymph node metastasis of unknown origin.

We report a very rare case of resected subsegmental lymph node metastasis of unknown origin. Hilar (N1) lymph node metastasis of unknown origin has previously been reported, but intrapulmonary lymph node metastasis has not been reported to date. At this patient's first visit to our hospital, an abnormal nodule was found on the upper lung lobe on a chest radiograph. After 4 years' follow-up, the nodule vanished, but a tiny nodule had emerged. 2-Fluoro-2-deoxy-D-glucose positron-emission tomography (FDG-PET) computed tomography was performed, and abnormal accumulation was observed only in the newly emerged intrapulmonary nodule. Right upper lobectomy was performed and a metastatic subsegmental lymph node, but no primary lesion, was found. Our observations suggest that evanescence of a suspicious primary lesion indicates the possibility of metastasis. FDG-PET was useful in this case for detecting lymph node metastases and demonstrating that the primary and further metastatic lesions were absent.

The Antemortem Diagnosis of Primary Malignant Pericardial Mesothelioma: A Multidisciplinary Evaluation.

A 64-year-old woman complaining of progressive dyspnea was admitted with recurrence of massive pericardial effusion. The patient had been diagnosed with radiation pericarditis based on a previous case of pericardiocentesis. To make a diagnosis and improve her symptoms, imaging examinations and pericardial fenestration were performed. Because of difficulty making a diagnosis, after some months, pericardiotomy and incision of the epicardium were performed. The patient was ultimately diagnosed with primary malignant pericardial mesothelioma of the epithelioid type. Primary malignant pericardial mesothelioma is a rare tumor that is difficult to diagnose. An antemortem diagnosis can be made by a multidisciplinary evaluation.

[Traumatic Lung Injury].

Pulmonary injuries requiring thoracotomy are uncommon. Most patients with lung injuries can be treated with a simple tube thoracostomy. Resectional procedures include non-anatomic lung resection, formal lobectomy and formal pneumonectomy. Non-anatomic lung resection is indicated for control of hemorrhage, control of air leaks and resection of destroyed lung tissues. Lobectomy and pneumonectomy are indicated for control of major air leaks, and control of life-threatening hemorrhage. The high mortality rates reported for pneumonectomy when performed after traumatic lung injury. Video-assisted thoracoscopic surgery (VATS) also has been demonstrated to be a reliable operative therapy for lung injury. Surgical treatment of traumatic pulmonary injuries requires knowledge of multiple approaches and operative interventions.

Combination effect of photodynamic therapy using NPe6 with pemetrexed for human malignant pleural mesothelioma cells.

To identify a possible new treatment modality for malignant pleural mesothelioma (MPM), we examined whether combination treatment consisting of pemetrexed chemotherapy and photodynamic therapy (PDT) using the photosensitizer NPe6, enhanced the antitumor effect in both in vitro and in vivo models. We also investigated preclinical treatment schedules. Four human malignant mesothelioma cell lines (MSTO­211H, H2052, H2452 and H28) were assayed using the WST assay after treatment with pemetrexed and NPe6­PDT. The treatment schedule for the combination treatment was examined using nude mice. Pemetrexed pre­treatment enhanced the lethal effect of NPe6­PDT in the four malignant mesothelioma cell lines, but NPe6­PDT followed by pemetrexed treatment did not enhance cell lethality in the in vitro assay. Pemetrexed pre­treatment did not enhance the intracellular accumulation of NPe6, which is one of the determinants of the antitumor effect of PDT. In nude mice injected with MSTO­211H cells and then treated using a combination of pemetrexed and NPe6­PDT (10 mg/kg NPe6, 10 J/cm(2) laser irradiation), the tumor volume decreased by 50% but subsequently increased, reaching the pre­treatment value after 14 days. Pemetrexed treatment followed by NPe6­PDT resulted in an 80% reduction in the tumor size and inhibited re­growth. NPe6­PDT followed by pemetrexed treatment resulted in a 60% reduction in tumor size but did not inhibit re­growth. NPe6­PDT induced the expression of thymidylate synthase (TS), which confers resistance to pemetrexed, and NPe6­PDT followed by pemetrexed treatment did not enhance the treatment outcome in vivo. In conclusion, combination treatment, consisting of pemetrexed followed by NPe6­PDT, should be further investigated as a new treatment modality for MPM. In the future, this combination treatment may contribute to a reduction in local recurrence and a prolonged survival period in patients with MPM.

An intrapericardial foregut cyst: report of a thoracoscopically resected case.

Intrapericardial foregut cysts are rare, and are usually found serendipitously. An abnormal shadow was incidentally found on a chest X-ray film of a 45-year-old asymptomatic female undergoing a regular check-up. Computed tomography revealed a smooth-walled, left mediastinal cyst (70 × 46 mm) immediately adjacent to the pericardium and left ventricle. We performed video-assisted thoracic surgery, which suggested that the lesion had macroscopically originated from the epicardium. However, the resected cyst was histologically determined to be an intrapericardial foregut cyst. This experience taught us that, while intrapericardial cysts possess the latent possibility of causing sudden death, cardiac failure, or eventual malignant changes, carefully planned and meticulously executed resection, avoiding damage to adjacent organs or vessels, is recommended.

Molecular determinants of photodynamic therapy for lung cancers.

BACKGROUND AND OBJECTIVES: PDT induces apoptosis, inflammatory reactions, immune reactions, and damage to the microvasculature around the tumors. The mechanisms responsible for the anticancer effects of Photofrin-PDT and NPe6-PDT differ somewhat. To select a photosensitizer for lung cancer treatment and to improve the efficacy of PDT, the mechanisms of action for PDT using Photofrin or NPe6 must be elucidated and the phenomena validated by analyzing molecular determinants from clinical samples. STUDY DESIGN/MATERIALS AND METHODS: We examined the role of immunological reactions in the anti-tumor effects of PDT using cytokine-overexpressing cells and investigated whether the anti-apoptotic protein Bcl-2 may be a molecular target. Moreover, we investigated the association between ATP-binding cassette transporter proteins such as breast cancer-resistant protein (BCRP), which can pump out some types of photosensitizer, and the efficacy of PDT using clinical samples from 81 early lung cancer lesions treated with PDT between 1998 and 2006 at the Tokyo Medical University Hospital. RESULTS: Photofrin-PDT damaged Bcl-2 and rapidly induced apoptosis, but NPe6-PDT did not damage Bc-2 nor did it induce morphologically typical apoptosis. However, NPe6-PDT exerted a strong anti-tumor effect, regardless of the overexpression of Bcl-2. By analyzing the BCRP-overexpressing cells, Photofrin, but not NPe6, was found to be a substrate of BCRP. All 81 lung cancer lesions were BCRP-positive; as Photofrin was found to be a substrate of BCRP, the expression of BCRP significantly affected the efficacy of Photofrin-PDT. However, NPe6-PDT exerted a strong antitumor effect regardless of BCRP expression, and the complete response rate after NPe6-PDT was much higher than that after Photofrin-PDT. CONCLUSIONS: Our translational research suggests that NPe6-PDT may be superior to Photofrin-PDT for the treatment of lung caner, and individualized approaches to PDT based on the expression status of Bcl-2 and/or BCRP may improve the efficacy of PDT in patients with lung cancers.

New aspects of photodynamic therapy for central type early stage lung cancer.

BACKGROUND: and Objective Photodynamic therapy (PDT) has come to be considered as the first choice of treatment for central type early stage lung cancer (CELC). Recent advances in the ability to diagnose CELC, and in photosensitizers, as well as sophisticated clinical management, may improve the therapeutic outcome and expand the indications of PDT. MATERIALS AND METHODS: We made the search for papers on PDT for lung cancer to select the most relevant articles. Based on this review and our recent data, we discussed the best available evidence for the diagnosis, the definition of indications, photosensitizers, and clinical management with regard to PDT. RESULTS: To obtain complete response (CR) by PDT, the selection of the indications is extremely important, including the extent of the tumor on the bronchial surface and the depth of invasion in the bronchial wall. The development of autofluorescence bronchoscopy (AFB) and endobronchial ultrasonography (EBUS) have had a large impact on diagnostic bronchoscopy for CELC. CELCs less than 1 cm in diameter showed a favorable cure rate by PDT, thus this is a good indication for PDT. The relatively newer photosensitizer NPe6, which has a stronger antitumor effect than Photofrin, showed similar treatment outcome even for large tumors >1.0 cm in diameter. Furthermore, comprehensive management including photodynamic diagnosis before and after PDT should be effective to minimize the possibility of local recurrence after PDT. CONCLUSION: The present guidelines of PDT for CELC were established based on the data obtained from studies in the 1980's. We postulate that comprehensive diagnosis and the new generation of photosensitizers may increase the CR rate and expand the indications of PDT for larger tumors.

Klotho predicts good clinical outcome in patients with limited-disease small cell lung cancer who received surgery.

BACKGROUND: The important role of surgery in early-stage small cell lung cancer (SCLC) has been recognized, and curative surgical resection is recommended. However, the role of adjuvant chemotherapy for stage I SCLC has not yet been evaluated, and novel approaches focusing on the specific genomic characteristics of SCLC may be invaluable for customized therapy. In this study, we focused on the Klotho gene, which is an anti-aging gene known to be a potential tumor suppressor. We investigated whether the expression of Klotho, assessed by immunohistochemistry, can predict survival in patients with resected SCLC. METHODS: The medical records of patients diagnosed as having limited-disease (LD) SCLC and treated by surgical resection (n=30) at Tokyo Medical University Hospital were retrospectively reviewed. The expression status of Klotho, and of the ATP-binding cassette (ABC) transporters MRP1, MDR and breast cancer resistant protein (BCRP), which can cause resistance to anticancer drugs, including irinotecan, was assessed by immunohistochemical analysis in resected surgical specimens of patients with early-stage SCLC. RESULTS: Of the 30 patients, Klotho expression was seen in the specimens from 18 patients (60.0%), but not in those of the remaining 12 patients (40.0%). The immunostaining for Klotho was mostly localized in the cytoplasm. The expression of Klotho was significantly associated with the overall survival (OS) (ratio 0.088; 95% confidence interval 0.019-0.409; P=0.002). The administration of perioperative chemotherapy had no significant effect in improving the survival, as assessed by the Kaplan-Meier method. However, the patients showing Klotho expression in the resected specimens in p-stage I and II, may have benefited from perioperative chemotherapy. A multivariate analysis revealed no significant association between the expression status of MRP1, MDR or BCRP and the OS. CONCLUSION: Expression of Klotho was predictive of a favorable outcome following resection in limited-disease SCLC patients, and the Klotho expression status may serve as a new biomarker for the need of additional therapies to be developed in the future.

Klotho is a novel biomarker for good survival in resected large cell neuroendocrine carcinoma of the lung.

BACKGROUND: In terms of prognosis, large cell neuroendocrine carcinoma (LCNEC) differs distinctively from other non-small cell lung cancers, with the prognosis of LCNEC being poor, even for early-stage disease. Improvements in survival require a biomarker capable of defining a subset of patients destined to do poorly so that these patients can be targeted for additional therapies, including chemotherapy. In this study, we focused on the Klotho gene, which is an anti-aging gene known to be a potential tumor suppressor. We investigated whether the immunohistochemical expression of Klotho can predict survival patients with resected LCNEC. METHODS: The histological characteristics of patients receiving an initial diagnosis of LCNEC (n=30) at Tokyo Medical University Hospital were retrospectively reviewed, and multiple variables including stage, lymphangioinvasion, lymph node status and the expression of Klotho as identified using an immunohistochemical analysis, were assessed. RESULTS: Immunostaining for Klotho was mostly cytoplasmic, and Klotho expression was seen in 10 patients (33.3%) but not in 20 patients (66.7%). The expression of Klotho was significantly associated with a good outcome of resected patients with LCNEC and Klotho(-) was associated with increased LCNEC risk by multivariate analysis (hazard ratio 4.92, 95% confidence interval 1.04-23.24, p=0.044). Neither lymph node status nor lymphangioinvasion were significantly associated with a poor survival. However, among patients without lymph node metastasis or angioinvasion, the survival benefit of Klotho expression in the primary tumor was significantly higher, compared with that of patients without Klotho expression. CONCLUSION: Klotho staining provides a new biomarker for a good outcome in patients with LCNEC, especially among patients without lymph node metastasis or lymphangioinvasion.

Outcomes of airway stenting for advanced lung cancer with central airway obstruction.

Approximately 30% of lung cancer patients will develop central airway obstruction (CAO). Interventional therapeutic bronchoscopy including airway stenting (AS) providing immediate and effective palliation is therefore essential to improve quality of life (QoL). However, no report has demonstrated the survival benefit of AS. We retrospectively reviewed 65 patients with CAO due to lung cancer who underwent AS from June 1994 to May 2008. Seventy-nine stents were required. Silicon, metallic, or both stents were placed in 42 (60%), 19 (29%), or eight (11%) patients, respectively. Single stent was required in 53 (83%) patients, double in 10 (14%), and triple in two (3%). AS could provide acute relief of central airway and significant improvement was seen in 98% of patients. Fifty-nine patients with detailed observations were assessed further. Morbidity and mortality rates were 22% and 8%, respectively. AS resulted in 25.2% of one-year survival rate and 6.2 months of median survival time (MST). AS followed by adjuvant therapy provided a four-month increase in MST, although overall survival was not significantly changed. This study represents a single-institution experience. Although an aggressive strategy of AS is justified in order to improve symptoms and QoL, AS itself did not contribute to survival benefit.

Outcome of photodynamic therapy using NPe6 for bronchogenic carcinomas in central airways >1.0 cm in diameter.

PURPOSE: Most centrally located early lung cancers (CLELC) <1.0 cm in diameter do not invade beyond the bronchial cartilage, and photodynamic therapy (PDT) with Photofrin is currently recommended as a treatment option for such lesions. NPe6 is a second-generation photosensitizer, and because it has a longer absorption band (664 nm) than Photofrin (630 nm), we hypothesized that NPe6-PDT would exert a strong antitumor effect against cancer lesions >1.0 cm in diameter, which are assumed to involve extracartilaginous invasion and to be unsuitable for treatment with Photofrin-PDT. EXPERIMENTAL DESIGN: Between June 2004 and December 2008, 75 patients (91 lesions) with CLELC underwent NPe6-PDT after the extent of their tumors had been assessed by fluorescence bronchoscopy for photodynamic diagnosis and tumor depth had been assessed by optical coherence tomography. RESULTS: Seventy cancer lesions < or =1.0 cm in diameter and 21 lesions >1.0 cm in diameter were identified, and the complete response rate was 94.0% (66 of 70) and 90.4% (19 of 21), respectively. After the mass of large tumors and deeply invasive tumors had been reduced by electrocautery, NPe6-PDT was capable of destroying the residual cancer lesions. CONCLUSION: NPe6-PDT has a strong antitumor effect against CLELCs >1.0 cm in diameter that have invaded beyond the bronchial cartilage, thereby enabling the destruction of residual cancer lesions after mass reduction of large nodular- or polypoid-type lung cancers by electrocautery. The PDT guidelines for lung cancers should therefore be revised because use of NPe6-PDT will enable expansion of the clinical indications for PDT.

Management of multiple primary lung cancer in patients with centrally located early cancer lesions.

BACKGROUND: Patients with centrally located early lung cancer (CLELC) are often heavy smokers with a considerably high risk of multiple primary lung cancer (MPLC) lesions; treatment strategies for such patients must preserve the cardiopulmonary function. METHODS: Between July 2004 and July 2008, patients with CLELC underwent photodynamic therapy (PDT) using NPe6, second-generation photosensitizer at Tokyo Medical University Hospital. Among these patients, we retrospectively analyzed MPLC, which was treated by surgery plus PDT or PDT alone and examined the effectiveness of PDT, and we propose a treatment strategy for patients with MPLC. RESULTS: A total of 64 patients with CLECL received NPe6-PDT, and MPLCs were found in 22 patients (34.4%) using sputum cytology and a bronchoscopical examination using autofluorescence bronchoscopy. Among these 22 patients, 10 patients underwent surgery for primary lung cancer and underwent NPe6-PDT for the treatment of secondary primary CLELC, one patient underwent PDT for CLELC as a primary lesion followed by an operation for peripheral-type lung cancer as a secondary primary lesion, and 11 patients underwent PDT alone for MPLC lesions (28 lesions) that were roentgenographically occult lung cancers. Among these 22 patients with MPLC including peripheral-type lung cancers, which were resected by surgery, all 39 CLELC lesions exhibited a complete response after PDT, and all patients were alive. CONCLUSIONS: For patients with lung cancer with a long-term history of smoking, careful follow-up examinations after surgical resection are needed considering the incidence of metachronous primary lung cancers. PDT can play an important role for the treatment strategy for MPLC.

Breast cancer resistant protein (BCRP) is a molecular determinant of the outcome of photodynamic therapy (PDT) for centrally located early lung cancer.

The ATP-binding cassette (ABC) transporter protein, BCRP (breast cancer resistance protein)/ABCG2 pumps out some types of photosensitizers used in photodynamic therapy (PDT) and causes resistance to the antitumor effect of PDT. The purpose of this study was to investigate the association between the expression of BCRP and the efficacy of PDT using Photofrin, or the second-generation photosensitizer, NPe6, for centrally located early lung cancers. Using human epidermoid carcinoma cells, A431 cells and the BCRP-overexpressing A431/BCRP cells, we examined the effects of BCRP expression on the effect of PDT by cell viability assay in vitro, and investigated the expression of BCRP by immunohistochemical analysis in 81 tumor samples obtained from patients with centrally located early lung cancers. The A431/BCRP cells were more resistant to Photofrin-PDT than A431 cells in vitro, and Fumitremorgin C, a specific inhibitor of BCRP, reversed the resistance. However, there was no significant difference in the antitumor effect of NPe6-PDT between these cells. All of the 81 centrally located early lung cancer lesions were BCRP-positive (2+, 45 lesions; 1+, 30 lesions) and all the patients were male and heavy smokers (>30 pack-years). The expression of BCRP significantly affected the efficacy of Photofrin-PDT in cancer lesions > or =10mm in diameter (P=0.04). On the other hand, NPe6-PDT exhibited a strong antitumor effect, regardless of the expression status of BCRP. Photofrin may be a substrate of BCRP and be pumped out from the cells, therefore, BCRP may be a molecular determinant of the outcome of Photofrin-PDT.

Tailor-made approach to photodynamic therapy in the treatment of cancer based on Bcl-2 photodamage.

It is very important to elucidate the mechanism of action and identify the molecular determinant of photodynamic medicine, in order to increase the number of clinical applications of photodynamic therapy (PDT) and perform personalized medicine. We have previously reported that PDT using some photosensitizers, such as phthalocyanine 4 (Pc 4) damages the anti-apoptotic protein Bcl-2, and that Bcl-2 is a molecular PDT target using a mitochondrion-targeting photosensitizer. In this study, we examined the molecular targets of Photofrin-PDT and NPe6-PDT, which are approved for early stage lung cancers by the Japanese Ministry of Health Labor and Welfare, by evaluating the photodamage to Bcl-2 using Western blot analysis. Our results showed that Photofrin-PDT damaged Bcl-2, induced morphologically typical apoptosis, and demonstrated equal sensitivity between MCF-7c3 cells (human breast cancer cells expressing stably transfected procaspase-3) and Bcl-2 overexpressing cells, MCF-7c3-GFP-Bcl-2 cells, with a clonogenic assay. However, NPe6-PDT did not damage Bcl-2 and took longer to induce typical apoptosis compared with Photofrin-PDT. MCF-7c3-GFP-Bcl-2 cells were considerably more resistant to the lethal effects of NPe6-PDT than parental MCF-7c3 cells. In conclusion, Photofrin-PDT damages different molecular targets, and our data indicate that the extent of Bcl-2 photodamage can determine the sensitivity of cancer cells to apoptosis and to overall cell killing caused by PDT using Photofrin, but not the lysosomal targeting NPe6. The application of these findings to clinical PDT may depend on the levels of the Bcl-2 proteins in the tumor being treated, and the tailor-made medicine based on the Bcl-2 photodamage may overcome any resistance afforded by elevated amounts of Bcl-2.

Long-term survival after a surgical resection of pulmonary metastases from gastric cancer: report of a case.

We describe a patient who survived for a prolonged period after repeated resections of pulmonary metastases from gastric cancer. A 59-year-old man underwent a distal gastrectomy for gastric cancer. A right middle lobectomy and a left lower lobectomy were performed for metastases from gastric cancer at 34 months and 82 months after the initial gastric resection, respectively. The patient died of cerebral infarction 65 months after the first lung resection, with no further relapse. To our knowledge, long-term survival after resection of pulmonary metastases from gastric cancer has only been reported in 3 patients previously. We herein review the literature and discuss the role of surgery in such patients.

Photodynamic therapy for lung cancers based on novel photodynamic diagnosis using talaporfin sodium (NPe6) and autofluorescence bronchoscopy.

BACKGROUND: We had previously developed the possibility of use of a photodynamic diagnosis (PDD) system using a tumor-selective photosensitizer and laser irradiation for the early detection and photodynamic therapy (PDT) for centrally located early lung cancers. Recently, we established the autofluorescence diagnosis system integrated into a videoendoscope (SAFE-3000) as a very useful technique for the early diagnosis of lung cancer. PATIENTS AND METHODS: Twenty-nine patients (38 lesions) with centrally located early lung cancer received PDD and PDT using the second-generation photosensitizer, talaporfin sodium (NPe6). Just before the PDT, we defined the tumor margin accurately using the novel PDD system SAFE-3000 with NPe6 and a diode laser (408nm). RESULTS: Red fluorescence emitted from the tumor by excitation of the photosensitizer by the diode laser (408nm) from SAFE-3000 allowed accurate determination of the tumor margin just before the PDT. The complete remission (CR) rate following NPe6-PDT in the cases with early lung cancer was 92.1% (35/38 lesions). We also confirmed the loss of red fluorescence from the tumors immediately after the PDT using SAFE-3000. We confirmed that all the NPe6 in the tumor had been excited and photobleached by the laser irradiation (664nm) and that no additional laser irradiation was needed for curative treatment. CONCLUSIONS: This novel PDD system using SAFE-3000 and NPe6 improved the quality and efficacy of PDT and avoided misjudgement of the dose of the photosensitizer or laser irradiation in PDT. PDT using NPe6 will become a standard option of treatments for centrally located early lung cancer.

Lysosomal cathepsin initiates apoptosis, which is regulated by photodamage to Bcl-2 at mitochondria in photodynamic therapy using a novel photosensitizer, ATX-s10 (Na).

ATX-s10 is a novel and second-generation photosensitizer for photodynamic therapy (PDT). In order to conduct clinical trials of ATX-s10-PDT and/or extend its clinical applications, it is very important to elucidate the mechanisms of the action of ATX-s10-PDT. We examined the apoptic response against ATX-s10-PDT using a Bcl-2 or Bcl-2 mutant overexpressing cells. Using fluorescent microscopy, ATX-s10 localized not only to mitochondria but also to lysosomes and possibly other intracellular organelles, but not to the plasma membrane or the nucleus. These results suggest that ATX-s10-PDT can damage mitochondria and lysosomes. By Western blot analysis, ATX-s10-PDT damaged Bcl-2, which localized preferentially at mitochondrial membranes, and caused Bcl-2 to cross-link immediately after laser irradiation. However, ATX-s10-PDT was not able to rapidly induce morphologically typical apoptosis (i.e. chromatin condensation and fragmentation) as PDT using mitochondria targeted photosensitizers, such as phthalocyanine 4 (Pc 4). Pharmacological inhibitions of lysosomal cytokine protease cathepsins, such as cathepsin B and D, protected MCF-7c3 cells (human breast cancer cells expressing stably transfected procaspase-3) from apoptosis caused by ATX-s10-PDT. Overexpression of wild-type Bcl-2 or Bcl-2Delta33-54 resulted in relative resistance of cells to ATX-s10-PDT, as assessed by the degree of morphological apoptosis or loss of clonogenicity. We conclude that lysosomal damage by ATX-s10-PDT can initiate apoptotic response and this apoptotic pathway can be regulated by photodamage to Bcl-2 via mitochondrial damage.

Optical coherence tomography in the diagnosis of bronchial lesions.

PURPOSE: Optical coherence tomography (OCT) can obtain high-resolution, cross-sectional microscopic images of tissue, potentially enabling optical biopsy to substitute for conventional excisional biopsy. We sought to investigate the capability of OCT to image the microstructure of normal and abnormal bronchial tissue. EQUIPMENT: The OCT system was produced by Light Lab Imaging (Boston, U.S.A.) and Pentax. (Tokyo, Japan). Preliminary examination: the OCT system was used to image-resected lung specimens from patients who had given written informed consent for this study. We inserted the OCT catheter via the working channel of the bronchoscope to evaluate the bronchial lumen. The catheter delivers a radial OCT beam and scans circumferentially to generate a transluminal image. We collected OCT images of normal bronchus, primary tumors and alveoli. All images were saved and labeled according to the patient and type of tissue imaged for later correlation with histologic studies. Clinical examination: five other patients, all of whom had given written informed consent, were examined with the OCT system under local anesthesia. The OCT catheter was inserted into the working channel of the bronchoscope for evaluation of the bronchial lumen. We collected OCT images of the normal bronchus and tumors in vivo. RESULTS: (1) Normal bronchus: the bronchial mucosal and submucosal layers appear homogeneous in OCT images. The submucosal layer is relatively reflective due to the presence of an extracellular matrix. A membrane can be seen between the submucosal and the smooth muscle layer, and areas of cartilage show high levels of scattering. (2) Alveoli: OCT images show the uniform appearance of the bronchial wall and the structure of air-containing alveoli. (3) Central type lung cancers: in preliminary and clinical examinations, the tumors showed unevenly distributed high backscattering areas and resultant loss of the normal layer structure. CONCLUSIONS: This study was the first report of the endobronchial OCT for lung cancer in clinical practice. Layers of the bronchial wall were distinctly observed in the normal bronchus on the OCT images, as opposed to bronchial tumors which lacked a layered structure. The ability of OCT to identify abnormal areas may well revise present methods for early diagnosis endoscopically.