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Akira Sakurada

Publications and source records attributed to Akira Sakurada.

At least 19 recordsLinked to original sources
PubMed2006

Microarray analysis of promoter methylation in lung cancers.

Aberrant DNA methylation is an important event in carcinogenesis. Of the various regions of a gene that can be methylated in cancers, the promoter is the most important for the regulation of gene expression. Here, we describe a microarray analysis of DNA methylation in the promoter regions of genes using a newly developed promoter-associated methylated DNA amplification DNA chip (PMAD). For each sample, methylated Hpa II-resistant DNA fragments and Msp I-cleaved (unmethylated+methylated) DNA fragments were amplified and labeled with Cy3 and Cy5 respectively, then hybridized to a microarray containing the promoters of 288 cancer-related genes. Signals from Hpa II-resistant (methylated) DNA (Cy3) were normalized to signals from Msp I-cleaved (unmethylated+methylated) DNA fragments (Cy5). Normalized signals from lung cancer cell lines were compared to signals from normal lung cells. About 10.9% of the cancer-related genes were hypermethylated in lung cancer cell lines. Notably, HIC1, IRF7, ASC, RIPK3, RASSF1A, FABP3, PRKCDBP, and PAX3 genes were hypermethylated in most lung cancer cell lines examined. The expression profiles of these genes correlated to the methylation profiles of the genes, indicating that the microarray analysis of DNA methylation in the promoter region of the genes is convenient for epigenetic study. Further analysis of primary tumors indicated that the frequency of hypermethylation was high for ASC (82%) and PAX3 (86%) in all tumor types, and high for RIPK3 in small cell carcinoma (57%). This demonstrates that our PMAD method is effective at finding epigenetic changes during cancer.

Adenocarcinoma↗
PubMed2006

Epidermal growth factor receptor tyrosine kinase inhibitors in lung cancer: impact of primary or secondary mutations.

The discovery of mutations in the tyrosine kinase (TK) domain of the epidermal growth factor receptor (EGFR) and the positive results of the National Cancer Institute of Canada Clinical Trials Group BR.21 phase III, randomized, placebo-controlled trial of erlotinib in patients with advanced-stage non-small-cell lung cancer that had failed to respond to first- or second-line chemotherapy provides new treatment options for patients with lung cancer and new insights into the pathophysiology of this malignancy. The similarity in patient characteristics significantly associated with EGFR mutations and in those who responded to therapy in BR.21 led to the hypothesis that EGFR mutation status can be used as a predictive marker for response and survival benefit in patients treated with the EGFR TK inhibitors erlotinib and gefitinib. This review summarizes the available data to date on the frequency and type of EGFR TK domain mutations and their association with clinical features, response, and survival outcome of patients treated with erlotinib and gefitinib.

Antineoplastic Agents↗
PubMed2005

Erlotinib in lung cancer - molecular and clinical predictors of outcome.

BACKGROUND: A clinical trial that compared erlotinib with a placebo for non-small-cell lung cancer demonstrated a survival benefit for erlotinib. We used tumor-biopsy samples from participants in this trial to investigate whether responsiveness to erlotinib and its impact on survival were associated with expression by the tumor of epidermal growth factor receptor (EGFR) and EGFR gene amplification and mutations. METHODS: EGFR expression was evaluated immunohistochemically in non-small-cell lung cancer specimens from 325 of 731 patients in the trial; 197 samples were analyzed for EGFR mutations; and 221 samples were analyzed for the number of EGFR genes. RESULTS: In univariate analyses, survival was longer in the erlotinib group than in the placebo group when EGFR was expressed (hazard ratio for death, 0.68; P=0.02) or there was a high number of copies of EGFR (hazard ratio, 0.44; P=0.008). In multivariate analyses, adenocarcinoma (P=0.01), never having smoked (P<0.001), and expression of EGFR (P=0.03) were associated with an objective response. In multivariate analysis, survival after treatment with erlotinib was not influenced by the status of EGFR expression, the number of EGFR copies, or EGFR mutation. CONCLUSIONS: Among patients with non-small-cell lung cancer who receive erlotinib, the presence of an EGFR mutation may increase responsiveness to the agent, but it is not indicative of a survival benefit.

Adenocarcinoma↗
PubMed2005

Computed tomographic images reflect the biologic behavior of small lung adenocarcinoma: they correlate with cell proliferation, microvascularization, cell adhesion, degradation of extracellular matrix, and K-ras mutation.

BACKGROUND: We previously reported that the computed tomographic M/L ratio (area of the tumor in the mediastinal computed tomographic image/area of the tumor in the lung computed tomographic image) of small peripheral lung adenocarcinoma is correlated with patient prognosis. METHODS: Immunostaining for p53, bcl-2, Ki-67, vascular endothelial growth factor, CD34, matrix metalloproteinase 2, matrix metalloproteinase 9, tissue inhibitor of matrix metalloproteinase 2, and mutation of K-ras was assessed in 131 surgically resected, primary peripheral lung adenocarcinomas of 30 mm or less in maximum diameter to clarify the relationship between computed tomographic findings and biologic activities. RESULTS: The numbers of patients with high labeling indexes of Ki-67 and high expression of vascular endothelial growth factor, CD34, matrix metalloproteinase 2, and matrix metalloproteinase 9 in the solid-type group (computed tomographic M/L ratio > or = 50%) were significantly higher than those in the faint density-type group (computed tomographic M/L ratio < 50%; P = .04 for Ki-67, P = .03 for vascular endothelial growth factor, P = .0009 for CD34, P = .001 for matrix metalloproteinase 2, and P = .00001 for matrix metalloproteinase 9). The number of patients with high levels of CD44v6 or tissue inhibitor of matrix metalloproteinase 2 staining in the faint density-type group was significantly higher than that in the solid-type group (P = .02 for CD44v6 and P = .01 for tissue inhibitor of matrix metalloproteinase 2). Independent variables capable of predicting computed tomographic M/L ratio included CD34, matrix metalloproteinase 2, matrix metalloproteinase 9, and tissue inhibitor of matrix metalloproteinase 2 (P = .0093, P = .0003, P = .0027, and P = .01, respectively; binary logistic regression analysis). CONCLUSIONS: Our results suggest that the computed tomographic image of small lung adenocarcinoma is correlated with biologic activities and thus provides possible prognostic information.

Adenocarcinoma↗
PubMed2004

Are difficulties during transbronchial lung biopsy/brushing through a fiberoptic bronchoscope based on the bronchial anatomy?

Some of the difficulties encountered during transbronchial lung biopsy through a flexible bronchofiberscope are due to anatomical reasons, namely the branching angles of some subsegmental bronchi from their mother bronchi are large, and differences in branching angles during respiration may also be large. This makes insertion of forceps difficult. We have sometimes experienced difficulties reaching the target lesion during a transbronchial approach. Which subsegmental bronchi make transbronchial lung biopsy/brushing difficult, and are such difficulties due to anatomical reasons? To answer these questions, we firstly surveyed 10 bronchologists regarding which five subsegmental bronchi they considered to be the most difficult for transbronchial biopsy/brushing. We then measured the branching angles of subsegmental bronchi in 106 cadaver lungs. Finally, in six volunteers, we also measured differences in branching angles of the subsegmental bronchi between the point of forced inspiration and the point of forced expiration on CT images. According to the survey, left B(1+2)c was considered to be the most difficult for insertion by nine doctors, followed by bilateral B6a by seven, right B1a by five, left B3a by five and left B(1+2)a by four. The results of our dissections showed that a branching angle of over 60 masculine was present in more than 10% of specimens in B3a, B6a and B6c in the right lung and in B(1+2)c, B3a, B6a and B6c in the left lung. In addition, three-dimensional reconstructed images revealed that the angles of some subsegmental bronchi changed during respiration. Inter-individual variations were present in most subsegmental bronchi. The direction of movement of each subsegmental bronchus during respiration varied. In addition, maximum degrees of difference in angles between volunteers were sometimes as much as 80 degrees . In conclusion, branching angles of subsegmental bronchi from their mother bronchi are large in B3a, B6a and B6c in the right lung and in B(1+2)c, B3a, B6a and B6c in the left lung. Most of these correspond to those which many bronchologists felt to be difficult for insertion. In addition, changes in the angles of subsegmental bronchi during respiration are likely to partially account for difficulties encountered during transbronchial approaches.

Aged↗
PubMed2004

Comparative histology of lymph nodes from aged animals and humans with special reference to the proportional areas of the nodal cortex and sinus.

Lymph nodes are composed of a lymphocyte-rich area or cortex (subdivided into the superficial and deep cortex and the medullary cord) and another, macrophage-rich area (incorporating the subcapsular and medullary sinuses). We measured the proportional area of the cortex in lymph nodes from aged experimental mammals (rats, guinea pigs, dogs and rabbits) and elderly Japanese humans. The cervical, axillary and inguinal nodes were generally richer in cortex tissue than the pulmonary regional and mesenteric nodes. Histological heterogeneity and medullary sinus dominance were much more evident in the human nodes than in those from animals, except for the guinea pig thoracic node. Human pulmonary regional nodes were characterized by a large medullary sinus; in guinea pigs, these nodes had a similar histology but the T lymphocyte-containing areas were smaller and thinner than in humans. The paraaortic node was well developed in humans and dogs, but not in other animals tested. These species- and region-specific histological differences may influence the evaluation of experimental animal models of lymph node function, such as those recently identified for research into sentinel nodes.

Aged↗
PubMed2004

Chromosome 12, frequently deleted in human pancreatic cancer, may encode a tumor-suppressor gene that suppresses angiogenesis.

Several lines of evidence have suggested that the long arm of chromosome 12 may carry a tumor-suppressor gene(s) that plays a role in pancreatic ductal carcinogenesis. We have previously found a significant association between loss of heterozygosity of the 12q arm and a poor prognosis in pancreatic cancer patients. In this study, we introduced a normal copy of chromosome 12 into some pancreatic ductal carcinoma cells. Both anchorage-dependent and -independent proliferations as well as invasiveness were similar throughout the hybrid clones when compared with their corresponding parental cells. In sharp contrast, significant suppression of tumorigenesis was observed after inoculation of the hybrid clones into nude mice. Measurements made up to 1 month later showed that there was a significant delay in the growth of tumors into which the introduced normal copy of chromosome 12 had been restored. More significantly, using our dorsal skin chamber and an intravital microscopy system experiment in SCID mice, we demonstrated and visualized directly that implantation of the hybrids failed to promote the angiogenic phenotype encountered in the parental cells. Gene expression profiling using the complementary DNA microarray system identified a set of 24 genes differentially expressed between the hybrids and parental cells. An additional set of 18 genes was also identified that were differentially expressed between the hybrid clone that lost its growth-suppression activity and one that retained such activity. Another set of 25 genes mapped on 12q was detected that showed high expression levels in the hybrid clones retaining growth-suppressive activity. In summary, this study provides the first functional evidence of the existence of an additional tumor-suppressor gene(s) on chromosome 12, whose absence is responsible for the pathogenesis in pancreatic ductal carcinogenesis.

Animals↗
PubMed2004

The natural history of radiographically occult bronchogenic squamous cell carcinoma: a retrospective study of overdiagnosis bias.

OBJECTIVE: An overdiagnosis bias occurs with the diagnosis of a disease that does not produce signs or symptoms before the patient dies from other causes. We sought to determine whether overdiagnosis bias is a factor when screening for squamous cell carcinoma of the lung. DESIGN: Retrospective study of the Miyagi Population-Based Lung Cancer Screening Registry for high-risk patients who were seen between January 1, 1982 (when sputum cytology tests were added for men with long smoking histories), and December 31, 1996. SETTING: Miyagi Prefecture, Japan. PATIENTS: A total of 251 patients (all men) who had sputum cytology test results that were positive for squamous cell carcinoma but had normal radiograph findings, 44 of whom declined cancer treatment (mean age, 70 years) and 207 of whom were treated with resection within 12 weeks of diagnosis (mean age, 65.5 year). END POINTS: Five-year and 10-year survival rates from primary lung cancer in both groups as of August 15, 2001. RESULTS: Among the 44 untreated patients, 15 (34%) remained asymptomatic. The survival rate due to primary lung cancer death in the untreated group was 53.2% at 5 years and 33.5% at 10 years. The survival rate among treated patients was 96.7% at 5 years and 94.9% at 10 years. Of the 125 treated patients who died, 14 (11.2%) died from primary lung cancer. CONCLUSION: Given that the two thirds of the untreated patients with squamous cell carcinoma of the bronchus died from lung cancer within 10 years, overdiagnosis bias does not appear to be a factor in screening for this disease. Thus, we recommend that patients with radiographically occult squamous cell carcinoma of the bronchus undergo tumor treatment after localization.

Aged↗
PubMed2004

A new technique for endobronchial ultrasonography and comparison of two ultrasonic probes: analysis with a plot profile of the image analysis software NIH Image.

STUDY OBJECTIVES: Endobronchial ultrasonography (EBUS) is currently the sole clinical method available for delineating the bronchial wall structure; however, the image resolution is inadequate. Thus, an improved image analysis system is needed for both a more accurate and more readily interpretable endobronchial ultrasonogram. MATERIALS AND METHODS: A total of 10 patients underwent pulmonary resection for lung cancer. EBUS was performed on the bronchi of the resected lungs, which had been immersed in physiologic saline solution. The same bronchial lesion in each specimen was imaged with two probes: 20 MHz and 30 MHz. The images were analyzed using the plot profile derived from freeware image analysis software: NIH Image (National Institutes of Health; Bethesda, MD). The measured echo intensity of the bronchial wall was statistically analyzed. RESULTS: A normal bronchial wall image consists of five layers, and the plot profile shows a W-shaped curve. The mean value of the echo intensity of each peak or trough of the W-shaped curve was calculated and compared for both probes. The differences in the mean echo intensity between both the third and fourth layer and the second and fourth layer were found to be significantly greater with the 30-MHz probe than with the 20-MHz probe. The echo intensity curve of a central-type lung cancer was not W shaped, indicating that the bronchial wall was not composed of the normal five layers. CONCLUSION: We employed image analysis software and drew a plot to obtain a W-shaped curve from the EBUS image data. This enabled us to make an objective assessment of the laminar structure of the bronchial wall. In order to clearly recognize the laminar structure of the bronchial wall, the 30-MHz probe was found to be more useful than the 20-MHz probe.

Bronchi↗
PubMed2004

[Management of central-type early lung cancer: an evidence-based clinical guideline].

With the support of the Japan Ministry of Health, Labour and Welfare, clinical guidelines for the management of lung cancer have been completed according to evidence-based methods. In this article, we focus on the guidelines for central-type early lung cancer. Reviewing a total of 3,196 reports that include key words related to central-type early lung cancer, 41 were selected and applied to determine recommendations for diagnostic or therapeutic methods. Among diagnostic methods, sputum cytology for the high-risk group and bronchoscopy for patients with positive sputum cytology were evaluated as recommendable. Among therapeutic methods, surgery and photodynamic therapy were evaluated as recommendable. For some methods, including fluorescence bronchoscopy and endobronchial ultrasonography brachitherapy, there was insufficient evidence to conclude that they are efficacious. At present, efforts to clarify the efficacy of these methods should be continued.

Bronchoscopy↗
PubMed2004

[Blunt tracheobronchial injury].

Blunt tracheobronchial injury is rare but crucial injury. We discussed some problems about blunt tracheobronchial injury and presented our experience. To rescue patients with blunt tracheobronchial injury, surgical treatment within 24 hours from injury is recommended when general anesthesia is acceptable. Therefore, bronchoscopy should be performed immediately for patients who transferred to hospital due to blunt chest trauma. Outcome of surgery for tracheobronchial injury depends on co-existence of other organs and the degree of tracheobronchial injury itself. To improve the prognosis of patients with blunt trachobronchial injury, we need to know the accurate incidence and results of treatment in Japan. To know the fact, a large-scaled prospective registration of cases with tracheobronchial injury is necessary. At present, the Japanese association for the surgery of trauma is conducting such registration. We present a 29 year-old male who had blunt tracheobronchial injury and underwent reconstruction of carina in our hospital. Rupture of carina was recognized by bronchscopy and pneumomediastinum was shown in chest computed tomography (CT). Operation was successfully performed 22 hours later from injury and the patient discharged 28 days after from injury.

Adult↗
PubMed2003

Endobronchial carcinoid tumor combined with pulmonary non-tuberculous mycobacterial infection: report of two cases.

We report here two cases of endobronchial carcinoid tumor complicated with pulmonary infection with non-tuberculous mycobacteria (NTM). Case 1 was an 81-year-old woman with the left lower lobe atelectasis. Bronchoscopy showed complete obstruction of the left basal bronchus by a tumor and a sleeve lower lobectomy with mediastinal lymph node dissection was performed. Pathological examination showed typical carcinoid located in the left basal bronchus and many caseous granulomas containing mycobacteria in the lung parenchyma distal to the bronchus. Bacterial examinations of sputum and gastric juice after the operation showed a growth of Mycobacterium kansasii. Case 2 was a 50-year-old woman with the atelectasis of the left upper division. Bronchoscopy showed complete obstruction of the left upper division bronchus by a tumor and a left upper lobectomy with mediastinal lymph node dissection was performed. Pathological examination showed typical carcinoid located in the left upper division bronchus and many caseous granulomas in the lung parenchyma distal to the bronchus. The Ziehl-Neelsen stain showed many mycobacteria in these granulomas and they were identified as Mycobacterium avium by PCR analysis. Although NTM are not well recognized as possible pathogens of pulmonary infection related to bronchial obstruction by endobronchial carcinoma, our experiences rouse a caution to consider NTM as potential pathogens. We also discuss the possible mechanisms responsible for the specific relationship between carcinoid tumor and TNM.

Aged↗
PubMed2003

hnRNP B1 protein may be a possible prognostic factor in squamous cell carcinoma of the lung.

Heterogeneous nuclear ribonucleoprotein (hnRNP) B1 is an RNA-binding protein that is required for the maturation of mRNA precursor. It was previously reported that hnRNP A2/B1 was overexpressed at the early clinical stage of lung cancer, and that hnRNP B1 protein, a splicing variant of hnRNP A2 mRNA, was elevated in lung cancer tissues. In this study, we applied the immunohistochemical method, using anti-hnRNP B1 antibody to analyze the usefulness of the hnRNP B1 antibody as a prognostic marker and also as a marker useful for early detection. A total of 206 specimens were examined. Histological examination revealed this protein to be positive in 79 (71.2%) of 111 squamous cell carcinomas and in 45 (64.3%) of 70 adenocarcinomas, respectively. This protein was also expressed in 24 (63.2%) of 38 roentgenographically occult carcinomas and in seven (63.6%) of 11 dysplastic lesions. These findings suggest the possible participation of this protein in early carcinogenesis. Furthermore, the survival curve of the squamous cell carcinoma patients with hnRNP B1 overexpresseion showed a better prognosis compared with that of the patients without hnRNP B1 expression (P=0.014), whereas in adenocarcinoma patients, there was no such a difference between them (P=0.889). These findings indicate that hnRNP B1 could be a useful marker for the early detection of bronchogenic squamous cell carcinoma and that it may be a prognostic factor in this cell type.

Biomarkers, Tumor↗
PubMed2003

A prospective evaluation of transbronchial ultrasonography for assessment of depth of invasion in early bronchogenic squamous cell carcinoma.

In order to determine the appropriate treatment modality for roentgenographically occult bronchogenic squamous cell carcinoma (ROSCC), it is essential to evaluate the depth of invasion, because ROSCC invading beyond the cartilaginous layer cannot be effectively treated by photodynamic therapy (PDT) due to spread of disease. Transtracheal endoscopic ultrasonography (TUS) was useful for predicting the depth of invasion in some ROSCCs. In order to assess the actual significance of TUS as a diagnostic tool for predicting the depth of carcinoma invasion, we have conducted a prospective trial with 22 lesions of ROSCCs. We ultrasonographically classified the degree of the depth of invasion into two groups; A: "invasion does not reach cartilaginous layer" and B: "invasion involves cartilaginous layer". Then the patients were treated by irradiation, PDT, or surgical resection. Pathological findings were also classified into A or B. In order to calculate the sensitivity for evaluating the depth of invasion by TUS, the cases without any tumor and/or malignant cells after PDT were regarded as pathological A. In the evaluation of the depth of carcinoma invasion staying inside the cartilaginous layer, the sensitivity and the positive predictive value were 85.7%, the specificity was 66.7%, and the accuracy was 80.0%. With TUS, preoperative evaluation of the depth of invasion would be more accurate, and the decision of treatment modality would be more appropriate, compared with the conventional bronchoscopic observation alone.

Aged↗
PubMed2003

Surgical treatment of stage I non-small cell lung carcinoma.

In stage I non-small cell lung cancer (NSCLC), the cancer is localized to the lung. For this early stage NSCLC, therefore, surgery is considered to be the treatment of choice. In this report, we reviewed the surgical treatment approaches for stage I NSCLC, placing emphasis on limited resection and video-assisted thoracic surgery (VATS). In regard to limited resection, sublobar resection (wedge resection and segmentectomy) may yield a good long-term outcome in selected cases, as does lobectomy. No strong evidence to recommend this procedure has, however, been published. On the other hand, many descriptive studies have indicated that VATS may be useful for the treatment of NSCLC, although the results have not shown any statistically significant differences from those of resection by conventional open thoracotomy. In addition to the low invasiveness, the curability of NSCLC using the VATS approach has been recognized to be similar to that of the standard thoracotomic approaches in clinical practice. Well-controlled studies with strong statistical results are needed to provide strong supportive evidence for the use of VATS for NSCLC. (Ann Thorac Cardiovasc Surg 2003; 9: 283-9)

Adult↗
PubMed2002

A microarray-based method for detecting methylated loci.

CpG island DNA methylation plays an important role in regulating gene expression in development and carcinogenesis. We developed a new microarray-based method called methylation amplification DNA chip (MAD) for detecting differences in methylation. In this method, only methylated CpG islands from the two samples that we wanted to compare were amplified and used for hybridization. The resource material for the microarray was derived from the methylated DNA library of the sample in which we wanted to detect hypermethylation. Choosing the methylated DNA library as the resource material of the microarray increased the percentage of DNA fragments derived from hypermethylated loci on the microarray.

Animals↗
PubMed2002

A prospective trial of systematic nodal dissection for lung cancer by video-assisted thoracic surgery: can it be perfect?

BACKGROUND: There have been no reports evaluating the completeness of systematic nodal dissection with video-assisted thoracic surgery (VATS). In order to elucidate the completeness of the dissection, we have conducted a prospective trial with patients having primary lung cancer. METHODS: Patients with clinical stage I lung cancer were the candidates for this study. Thoracotomy was performed with a small skin incision of 7 cm to 8 cm in length. Through these small wounds and two trocars, pulmonary resection was performed and then hilar and mediastinal lymph nodes were dissected. After that, a standard thoracotomy was carried out by another surgeon to complete systematic nodal dissection. RESULTS: Video-assisted thoracic surgery lobectomy with lymph node dissection was accomplished in 17 right lung cancer patients and 12 left lung cancer patients. On the right side, the average numbers of resected lymph nodes by VATS and remnant lymph nodes were 40.3 and 1.2, respectively. The average weights of dissected tissues by VATS and remnant tissues were 10.0 g and 0.2 g, respectively. On the left side, there were 37.1 and 1.2 lymph nodes and 8.3 g and 0.2 g of weight of dissected tissues. No nodal involvement was observed in the remnant lymph nodes. CONCLUSIONS: The lymph node dissection with VATS was technically feasible and the remnant ("missed" by VATS) lymph nodes and tissues were 2% to 3%, which seems acceptable for clinical stage I lung cancer.

Adult↗