Mutations in the epidermal growth factor receptor (EGFR) gene have been reported to be present in non-small cell lung cancer (NSCLC) and related to the responsiveness of tumors to EGFR tyrosine ...kinase inhibitors, suggesting its usefulness as a biomarker. Because clinical samples contain tumor and normal cells or genes, a highly sensitive assay for detecting mutation is critical for clinical applications.
The mutant-enriched PCR is a rapid and sensitive assay with selective restriction enzyme digestion. We developed the mutant-enriched PCR assay targeting exons 19 and 21 of EGFR and applied the developed assay to detect mutations in 108 cases of surgically resected specimens of NSCLCs, 18 samples of computed tomography (CT)-guided needle lung biopsies, and 20 samples of pleural fluid. In addition, results were then compared with those from direct sequencing and a nonenriched PCR assay.
The mutant-enriched PCR that was proved to enrich one mutant of 2 x 10(3) normal genes detected mutations in 37 cases of 108 resected tumors, seven samples of CT-guided lung biopsies, and seven samples of pleural fluid. Among mutant cases, four resected tumors, two CT-guided lung biopsies, and two pleural fluid were identified as additional mutant cases by the mutant-enriched PCR, which were considered normal based on nonenriched assays.
Our results indicate that EGFR mutations are readily detectable by mutant-enriched PCR in various clinical samples. Thus, mutant-enriched PCR may provide a valuable method of potentially detecting a small fraction of mutant genes in heterogeneous specimens, indicating its possible use in clinical application for NSCLC.
The value of radical systematic lymphadenectomy for treatment of early‐stage bronchial carcinoma is controversial. We performed a prospective randomized study to address this question. Altogether 115 ...patients with peripheral non‐small‐cell lung cancers smaller than 2 cm in diameter were enrolled in this study. They were randomly assigned into a lobectomy with lymph node sampling group (sampling group, n= 56) or a lobectomy with radical systematic lymph node dissection group (dissection group,n= 59). Inclusion criteria were based only on preoperative clinical studies. Four tumors were larger than 2 cm postoperatively. One patient had disseminated disease, and two had intrapulmonary metastases discovered at surgery. Two patients had small‐cell carcinoma. There were four with pathologic N1 disease and seven with N2 disease in the dissection group and three with N1 and eight with N2 disease in the sampling group. The numbers of local and distant recurrences were two and six, respectively, in the dissection group and two and five in the sampling group. The overall 5‐year survival was 81% in the dissection group and 84% in the sampling group. No significant differences in the recurrence rate or survival was seen between the groups. Our results demonstrate that clinically evaluated peripheral non‐small‐cell carcinomas smaller than 2 cm in diameter do not require radical systematic mediastinal and hilar lymph node dissection.
Chlamydophila felis (Chlamydia psittaci feline pneumonitis agent) is a worldwide spread pathogen for pneumonia and conjunctivitis in cats. Herein, we determined the entire genomic DNA sequence of the ...Japanese C. felis strain Fe/C-56 to understand the mechanism of diseases caused by this pathogen. The C. felis genome is composed of a circular 1,166,239 bp chromosome encoding 1005 protein-coding genes and a 7552 bp circular plasmid. Comparison of C. felis gene contents with other Chlamydia species shows that 795 genes are common in the family Chlamydiaceae species and 47 genes are specific to C. felis. Phylogenetic analysis of the common genes reveals that most of the orthologue sets exhibit a similar divergent pattern but 14 C. felis genes accumulate more mutations, implicating that these genes may be involved in the evolutional adaptation to the C. felis-specific niche. Gene distribution and orthologue analyses reveal that two distinctive regions, i.e. the plasticity zone and frequently gene-translocated regions (FGRs), may play important but different roles for chlamydial genome evolution. The genomic DNA sequence of C. felis provides information for comprehension of diseases and elucidation of the chlamydial evolution.
We sought a marker to differentiate tuberculous pleural effusions from nontuberculous pleural effusions, which otherwise can be difficult.
We studied 55 patients with pleural effusions, 20 (36%) with ...tuberculous pleuritis and 35 (64%) with a nontuberculous etiology.
Pleural fluid levels of adenosine deaminase, interferon (INF)-γ, interleukin (IL)-12p40, IL-18, immunosuppressive acidic protein, and soluble IL-2 receptors were measured and were subjected to receiver operating characteristic analysis. INF-γ had the greatest sensitivity and specificity for tuberculous pleuritis among the six biological markers studied.
The determination of INF-γ levels in pleural fluid is the most informative in the diagnosis of tuberculous effusion.
A new marking technique was developed to localize small or indistinct pulmonary lesions, involving preoperative radioisotope injection and intraoperative detection with a handheld gamma probe.
...National hospital for respiratory disease.
A technetium suspension (either 99mTc tin colloid 2 to 4 mCi, 0.5 to 2.5 mL or 99mTc phytate 2 mCi, 2.0 mL) was injected preoperatively in the vicinity of the lesion under CT guidance in 25 patients with small or indistinct pulmonary lesions. A handheld gamma probe (Navigator GPS; Tyco Healthcare Japan; Tokyo, Japan) was used to detect the hot spot where radioactivity was localized during surgery. The lesion marked by the radioisotope then was thoracoscopically resected using endostaplers.
The preoperative marking procedure took approximately 30 min. A small pneumothorax and mild intrapulmonary bleeding were observed in two patients and one patient, respectively, but no additional treatment was needed for these complications. The lesion was resected soon after the marking procedure in 21 patients, and on the next day in 4 patients. All lesions were easily identified during surgery as radioactive hot spots detected by the handheld gamma probe. Thoracoscopic wedge resection was successfully performed in all patients without complications.
This new marking technique for small or indistinct pulmonary lesions (radioisotope injection under CT guidance and intraoperative detection with a handheld gamma probe) seems to be safe, reliable, and convenient.
Malignant mesothelioma is the most common primary pleural neoplasm. Association of simian virus 40 (SV40) with malignant mesothelioma has been reported, suggesting that SV40 plays an important role ...in the origin of a subset of these tumors. However, significant geographic variation is present as to how often this association occurs. As no study concerning SV40 in malignant mesothelioma has been reported from Japan, we examined the frequency of SV40 infection in Japanese malignant mesothelioma cases. In pleural malignant mesothelioma tissue from 35 patients in Japan, we sought the presence of SV40 large T antigen DNA using real‐time polymerase chain reaction (PCR), as well as expression of the viral protein using immunohistological methods. Real‐time PCR demonstrated that two of 35 mesotheliomas contained DNA sequences encoding portions of SV40 large T antigen. None of the 35 malignant mesothelioma specimens showed immunoreactivity for SV40 large T antigen. SV40 infection does not appear to have a major role in the development of malignant mesothelioma in Japan. (Cancer Sci 2006; 97: 292–295)
Malignant mesothelioma is the most common primary pleural neoplasm. Angiogenesis is an important component of a variety of pathological processes, including carcinogenesis and tumor metastases. ...Vascular endothelial growth factor (VEGF) is the most potent known endothelial, cell specific mitogen. The authors assessed the relation between VEGF expression and clinicopathological variables or overall survival, in malignant mesothelioma. We studied 37 patients with malignant pleural mesothelioma and found that 36 out of 37 (97.3%) malignant mesothelioma samples were stained positively for VEGF. An increased expression of VEGF was observed in the epithelioid type compared with the other histological types of malignant mesothelioma, including the biphasic and sarcomatoid types. No statistically significant association was observed between VEGF expression and gender, age, or clinical stage. Furthermore, the expression of VEGF did not impact on the survival of patients with malignant mesothelioma. Although VEGF expression might be important for tumor development and maintenance, it was not identified as a prognostic factor in malignant mesothelioma.
Heterogeneous nuclear ribonucleoprotein B1, an RNA‐binding protein required for mRNA maturation, reportedly is overexpressed in early lung cancer and in several other tumors, including precancerous ...lesions. Expression of the protein was assessed immunohistochemically in 39 specimens of malignant mesothelioma and five of non‐neoplastic pleura, and by flow cytometry in a human epithelioid mesothelioma cell line. No tumor showed overexpression, but 29 of 39 cases showed modest expression. Patients whose tumors showed expression had significantly better survival rates than others. Epithelioid tumors and reactive mesothelial cells were more likely to express the protein than sarcomatoid tumors and resting mesothelial cells. Flow cytometric analysis of an epithelioid mesothelioma cell line demonstrated stronger expression in exponentially growing than growth‐restricted cells. Heterogeneous nuclear ribonucleoprotein B1 is expressed widely in malignant mesotheliomas and in reactive mesothelial cells, but is not overexpressed. This protein may regulate proliferation linked with differentiation toward epithelioid morphology in mesothelial cells. Expression of the protein may be a prognostic indicator for patents with malignant mesothelioma. (Cancer Sci 2006; 97: 1175–1181)
Rac1, one of the Rho family small guanosine triphosphatases, has been shown to work as a "molecular switch" in various signal transduction pathways. To assess the function of Rac1 in the ...differentiation process of CD4 single-positive (CD4-SP) T cells from CD4CD8 double-positive (DP) cells, we used a DP cell line DPK, which can differentiate into CD4-SP cells upon TCR stimulation in vitro. DPK expressing dominant-negative (dn)Rac1 underwent massive apoptosis upon TCR stimulation and resulted in defective differentiation of CD4-SP cells. Conversely, overexpression of dnRac2 did not affect differentiation. TCR-dependent actin polymerization was inhibited, whereas early ERK activation was unaltered in dnRac1-expressing DPK. We found that TCR-dependent induction of Bcl-2 was suppressed greatly in dnRac1-expressing DPK, and this suppression was independent of actin rearrangement. Furthermore, introduction of exogenous Bcl-2 inhibited TCR-dependent induction of apoptosis and restored CD4-SP generation in dnRac1-expressing DPK without restoring TCR-induced actin polymerization. Collectively, these data indicate that Rac1 is critical in differentiation of CD4-SP from the DP cell line by preventing TCR-induced apoptosis via Bcl-2 up-regulation.
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