Is Interstitial Pneumonia in Patients with Collagen Diseases a Contraindication to Lung Cancer Surgery?

PURPOSE

Lung cancer surgery can be dangerous in patients with interstitial pneumonia (IP) as acute exacerbation of the IP may prove fatal. It remains unclear if patients with collagen diseases (CD), who often suffer from IP, are also at increased risk during lung cancer surgery.

METHODS

We retrospectively examined 17 (3.1%) patients with CD among 545 patients who underwent surgery for lung cancer at our institution.

RESULTS

Nine patients with rheumatoid arthritis, five with systemic sclerosis, two with Sjögren's disease, and one with systemic lupus erythematosus were enrolled in this study. Eleven patients (65%) were taking corticosteroids at the time of surgery. Fourteen patients underwent lobectomy and lymph node dissection, and three patients with pStage IA lung cancer underwent pulmonary wedge resection. Pathologically, 11 (65%) patients had IP with various inflammatory cellular infiltrations, and three (18%) had honeycombing of the lung. Postoperatively, none of the patients suffered acute exacerbation of their IP.

CONCLUSIONS

Despite the high incidence of IP in patients with lung cancer and CD, our results suggest that CD is not a contraindication to the surgical resection of lung cancer.

[Pulmonary thromboembolism after lung resection in patients with schizophrenia; report of 2 cases]

We report 2 cases of pulmonary thromboembolism after lung resection in patients with schizophrenia. The first case is a 67-year-old woman. She underwent right lower lobectomy for primary lung cancer and suddenly felt dyspnea 2 days after the operation. She was diagnosed pulmonary thromboembolism by computed tomography (CT) and lung perfusion scintigram, and recoverd soon. The second case is a 42-year-old man. He underwent partial resection of the right lung for metastatic germ cell tumor. Six days after the operation, he fell into acute respiratory failure and died in spite of resuscitation. The autopsy showed that the cause of death was pulmonary thromboembolism. Because patients with schizophrenia have high-risk of pulmonary thromboembolism, extreme care must be exercised to avoid it.

CYP2A7 polymorphic alleles confound the genotyping of CYP2A6*4A allele

Human cytochrome P450 (CYP) 2A6 metabolizes nicotine to cotinine. Genetic polymorphisms of CYP2A6 contribute to the interindividual variability of nicotine metabolism. We encountered some subjects possessing two copies of the CYP2A6 gene, although they were genotyped as heterozygotes of the CYP2A6*4A allele (entire CYP2A6 gene deleted allele). From the subjects, we found CYP2A7 polymorphic alleles (CYP2A7*1B, CYP2A7*1C, and CYP2A7*1D) in which the sequences in the 3'-flanking region were converted to the corresponding CYP2A6 sequences, being confused with the CYP2A6*4A. These allele frequencies in European-Americans (n=187) were 1.3, 2.1, 0.3%, respectively, but these were very rare in African-Americans (n=176), Japanese (n=184), and Koreans (n=209). By an improved genotyping method, the allele frequency of CYP2A6*4A of 3.7% in European-Americans was corrected to 0%. The comprehensible and reliable genotyping method developed in this study would be useful to evaluate associations between the genotype and phenotype.

Hypermethylation of the TSLC1/IGSF4 promoter is associated with tobacco smoking and a poor prognosis in primary nonsmall cell lung carcinoma

BACKGROUND

The tumor suppressor gene TSLC1/IGSF4 on chromosomal region 11q23 is frequently inactivated by promoter methylation in various cancers, including nonsmall cell lung carcinoma (NSCLC). Several studies have demonstrated that the hypermethylation of the CpG islands of genes, including tumor suppressors, is associated with exposure to tobacco smoke. The purpose of this study was to investigate the possible association of TSLC1/IGSF4 methylation with tobacco smoking as well as with the clinical characteristics of tumors using a large number of primary NSCLC.

METHODS

The promoter methylation of TSLC1/IGSF4 was analyzed in 103 primary NSCLC. TSLC1/IGSF4 expression was examined by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry, whereas its methylation status was determined by bisulfite single-strand conformation polymorphism (SSCP) coupled with bisulfite sequencing.

RESULTS

The TSLC1/IGSF4 promoter was methylated in 45 (44%) of 103 primary NSCLC. Methylation was observed in all histologic subtypes of NSCLC, including adenocarcinoma (29 of 68, 43%), squamous cell carcinoma (14 of 26, 54%), adenosquamous carcinoma (1 of 2, 50%), and large cell carcinoma (1 of 7, 14%). The incidence of methylation in tumors was significantly higher in male patients than in female patients (P = .027). The TSLC1/IGSF4 methylation was preferentially observed in heavy smokers (smoking index > or = 800) (P = .0054). Furthermore, in smokers the methylation was significantly associated with pack-years smoked (P = .034) and cigarettes per day (P = .021). The TSLC1/IGSF4 methylation was also significantly associated with a shorter disease-free survival (P = .049), providing an independent prognostic factor (P = .038) in adenocarcinoma patients.

CONCLUSIONS

TSLC1/IGSF4 methylation is associated with tobacco smoking and could be an indicator of poor prognosis.

Disruption of spermatogenic cell adhesion and male infertility in mice lacking TSLC1/IGSF4, an immunoglobulin superfamily cell adhesion molecule

TSLC1/IGSF4, an immunoglobulin superfamily molecule, is predominantly expressed in the brain, lungs, and testes and plays important roles in epithelial cell adhesion, cancer invasion, and synapse formation. We generated Tslc1/Igsf4-deficient mice by disrupting exon 1 of the gene and found that Tslc1(-/-) mice were born with the expected Mendelian ratio but that Tslc1(-/-) male mice were infertile. In 11-week-old adult Tslc1(-/-) mice, the weight of a testis was 88% that in Tslc1(+/+) mice, and the number of sperm in the semen was approximately 0.01% that in Tslc1(+/+) mice. Histological analysis revealed that the round spermatids and the pachytene spermatocytes failed to attach to the Sertoli cells in the seminiferous tubules and sloughed off into the lumen with apoptosis in the Tslc1(-/-) mice. On the other hand, the spermatogonia and the interstitial cells, including Leydig cells, were essentially unaffected. In the Tslc1(+/+) mice, TSLC1/IGSF4 expression was observed in the spermatogenic cells from the intermediate spermatogonia to the early pachytene spermatocytes and from spermatids at step 7 or later. These findings suggest that TSLC1/IGSF4 expression is indispensable for the adhesion of spermatocytes and spermatids to Sertoli cells and for their normal differentiation into mature spermatozoa.

Appraisal of surgical treatment for pulmonary metastasis from hepatocellular carcinoma

The outcome of pulmonary metastasectomy of hepatocellular carcinoma (HCC) was appraised in this study. Twenty patients with pulmonary metastasis from HCCs undergoing pulmonary resection between 1990 and 2003 were included in this study. They had undergone curative treatment for the primary lesion and were candidates for a pulmonary metastasectomy for complete resection. Among the 20 patients, 13 died: 5 from hepatic failure, 5 from respiratory failure, and 2 from brain metastasis due to recurrence of the HCC. One patient died from cardiac failure without HCC recurrence. At the latest observation, three of the seven survivors were doing well without HCC recurrence, and others survived with recurrence. The overall survival rates after the initial lung surgery were 45.3% at 1 year and 23.8% at 3 years, respectively. The survival rates without recurrence were 32.4% at 1 year and 21.6% at 3 years, respectively. A Kaplan-Meier analysis showed that multiple lung surgeries and a negative histologic finding of the liver cut surface were favorable characteristics for survival without recurrence. In conclusion, the selected patients were Candidates for pulmonary metastasectomy after a curative hepatectomy for HCC and could benefit from the complete resection. Also, repeated pulmonary resections through thoracoscopy could result in the long-term survival of patients with pulmonary recurrence of HCC.

Promoter methylation of DAL-1/4.1B predicts poor prognosis in non-small cell lung cancer

PURPOSE

DAL-1/4.1B is an actin-binding protein originally identified as a molecule whose expression is down-regulated in lung adenocarcinoma. We have previously shown that a lung tumor suppressor, TSLC1, associates with DAL-1, suggesting that both proteins act in the same cascade. The purpose of this study is to understand the molecular mechanisms and clinical significance of DAL-1 inactivation in lung cancer.

EXPERIMENTAL DESIGN

We studied aberration of the DAL-1 in 103 primary non-small cell lung cancers (NSCLC) and 18 lung cancer cells. Expression and allelic and methylation status of DAL-1 was examined by reverse transcription-PCR, microsatellite analysis, and bisulfite sequencing or bisulfite single-strand conformational polymorphism, respectively.

RESULTS

Loss of DAL-1 expression was strongly correlated with promoter methylation in lung cancer cells, whereas DAL-1 expression was restored by a demethylating agent, 5-aza-2'-deoxycytidine. The DAL-1 promoter was methylated in 59 (57%) primary NSCLC tumors, 37% of which were associated with loss of heterozygosity around the DAL-1 on chromosomal region 18p11.3. In squamous cell carcinomas, DAL-1 methylation was observed in 9 of 10 tumors at stage I, whereas the incidence of methylation gradually increased in adenocarcinomas as they progressed [13 of 36 (36%), 4 of 12 (33%), 14 of 17 (82%), and 3 of 3 (100%) tumors at stages I, II, III, and IV, respectively; P = 0.0026]. Furthermore, in adenocarcinomas, disease-free survival and overall survival were significantly shorter in patients with tumors harboring the methylated DAL-1 (P = 0.0011 and P = 0.045, respectively).

CONCLUSIONS

DAL-1 methylation is involved in the development and progression of NSCLC and provides an indicator for poor prognosis.

Rearrangement of T-cell receptor beta and gamma genes in thymoma

To investigate the differentiation stage of tumor-infiltrating lymphocytes in thymoma tissue, we performed Southern blot analysis of T-cell receptor beta and gamma genes in thymomas resected from 19 patients. At the same time, we conducted flow cytometric analysis of T-cell surface markers and examined the clinicopathological features of the thymomas. We found that the incidence of T-cell receptor gamma gene rearrangement was significantly higher in Masaoka stage I thymomas (11 of 12 cases) than in stage II or III invasive thymomas (3 of 7 cases). Moreover, gamma gene rearrangement was observed in all 10 type AB and B1 thymoma specimens and in 4 of 6 type B2 thymoma specimens. The 2 specimens of type B3 thymomas, which were classified as stage III, showed neither gamma nor beta gene arrangement and were single-positive for CD4 or CD8. Six thymoma specimens that showed beta gene rearrangement expressed both CD4 and CD8. In conclusion, thymomas have the capability of T-lineage cell differentiation, except for a subset of invasive thymomas with malignant characteristics.

Overexpression of a cell adhesion molecule, TSLC1, as a possible molecular marker for acute-type adult T-cell leukemia

Adult T-cell leukemia (ATL) caused by human T-cell leukemia virus type 1 (HTLV-1) infection, occurs in 2% to 4% of the HTLV-1 carriers with a long latent period, suggesting that additional alterations participate in the development of ATL. To characterize and identify novel markers of ATL, we examined the expression profiles of more than 12 000 genes in 8 cases of acute-type ATL using microarray. One hundred ninety-two genes containing interleukin 2 (IL-2) receptor alpha were up-regulated more than 2-fold compared with CD4(+) and CD4(+)CD45RO(+) T cells, and tumor suppressor in lung cancer 1 (TSLC1), caveolin 1, and prostaglandin D2 synthase showed increased expression of more than 30-fold. TSLC1 is a cell adhesion molecule originally identified as a tumor suppressor in the lung but lacks its expression in normal or activated T cells. We confirmed ectopic expression of the TSLC1 in all acute-type ATL cells and in 7 of 10 ATL- or HTLV-1-infected T-cell lines. Introduction of TSLC1 into a human ATL cell line ED enhanced both self-aggregation and adhesion ability to vascular endothelial cells. These results suggested that the ectopic expression of TSLC1 could provide a novel marker for acute-type ATL and may participate in tissue invasion, a characteristic feature of the malignant ATL cells.

Isolation of the mouse Tsll1 and Tsll2 genes, orthologues of the human TSLC1-like genes 1 and 2 (TSLL1 and TSLL2)

We have recently identified the human TSLL1 and TSLL2 genes, which are highly homologous to the human lung tumor suppressor gene, TSLC1. Loss of expression of the TSLL1 or TSLL2 in several cancers suggests that these genes could also act as tumor suppressors. Here, we report the isolation of the mouse orthologous genes, Tsll1 and Tsll2. The Tsll1 and Tsll2 cDNAs contain a single open reading frame of 1188 and 1164 bp encoding a putative immunoglobulin-like cell adhesion molecules of 396 and 388 amino acids, which display 95% and 98% identity with those of human TSLL1 and TSLL2, respectively. The Tsll1 and Tsll2 genes are both composed of nine exons and mapped on mouse chromosome 1q H2-H4 and on 7q A3-B2, respectively, both of which conserve syntenies with human chromosomes 1q and 19q. Like the human TSLL1, the mouse Tsll1 was expressed exclusively in the brain and neurogenic cells, while Tsll1 expression was lost in one of four rodent neuroblastoma cell lines. Tsll2 was expressed in the brain and several organs including the kidney and liver, whereas loss of Tsll2 expression was detected in some rodent cancer cells derived from these tissues. Furthermore, both murine TSLL1 and TSLL2 proteins were expressed on the plasma membrane, especially at the cell-cell attached site. These data, together with their strong conservation during the vertebrate evolution, suggest that TSLL1and TSLL2 could play an important role in cell-cell interaction as well as in tumor suppression.

Association of a lung tumor suppressor TSLC1 with MPP3, a human homologue of Drosophila tumor suppressor Dlg

We have previously identified the tumor suppressor in lung cancer 1 (TSLC1) gene as a novel tumor suppressor in human non-small cell lung cancer (NSCLC) by functional complementation. TSLC1 encodes a membrane glycoprotein belonging to an immunoglobulin superfamily and participates in cell adhesion. A truncating mutation of the TSLC1 corresponding to its cytoplasmic domain in a primary NSCLC tumor suggests that this domain is important for tumor suppressor activity. Here, we report that TSLC1 directly associates with MPP3, one of the human homologues of a Drosophila tumor suppressor gene, Discs large (Dlg). This interaction was dependent on the presence of a PDZ-binding motif at the carboxyl terminus of TSLC1. Furthermore, TSLC1 and MPP3 were colocalized at the cell-cell attachment sites in both a low and a high cell density. The MPP3 gene was expressed in normal lung as well as in many tissues examined except for peripheral blood lymphocytes but lost its expression in one of the nine NSCLC cell lines. These results suggest that TSLC1 and MPP3 are involved in the same cascade of cell-cell interaction, and that the disruption of this cascade might lead cells to malignant growth and tumor formation in lung cancer.

Promoter methylation of the TSLC1 gene in advanced lung tumors and various cancer cell lines

We previously identified TSLC1, a tumor suppressor gene in human nonsmall cell lung cancer (NSCLC). TSLC1 belongs to immunoglobulin superfamily molecules and is involved in cell adhesion. Loss of TSLC1 expression was strongly correlated with the promoter hypermethylation in several NSCLC cell lines. Here, we examined the methylation status of the TSLC1 gene promoter in 48 primary NSCLC tumors by bisulfite SSCP in combination with bisulfite sequencing. Six CpG sites around the promoter regions were significantly methylated in 21 of 48 primary NSCLC tumors (44%). Promoter methylation was more likely to be observed in relatively advanced tumors with TNM classification of pT2, pT3 or pT4 (19 of 33, 58%) than in those with pT1 (2 of 15, 13%), suggesting that alteration of TSLC1 would be involved in the progression of human NSCLC. Loss of TSLC1 expression was also observed in 20 of 46 (43%) human cancer cell lines, including those from esophageal (3 of 3), gastric (8 of 9), ovarian (2 of 5), endometrial (2 of 2), breast (1 of 3), colorectal (2 of 8) and small cell lung cancers (2 of 10). Combined analysis of promoter methylation and the allelic state in these cell lines indicated that the TSLC1 gene was often silenced not only by mono-allelic methylation associated with loss of the other allele but also through bi-allelic methylation. These results suggest that alteration of TSLC1 would be involved in advanced NSCLC as well as in many other human cancers.

A novel method for DNA molecular counting

We have developed a new method for counting DNA molecules using 'capillary-plates' consisting of a large number of small glass-capillary 'channels' fused together in parallel. PCR mixtures containing serially diluted DNA templates with the DNA indicator dye Hoechst 33258 were poured into the plates and sealed with silicone rubber-plates. Following 40 PCR cycles, fluorescence microscopy revealed that the fluorescence in some channels had increased about three-times more than in others at template concentrations of 1 fM or lower. No bright fluorescence was observed in the absence of template. The relationship between the proportion of fluorescent channels in the capillary-plates and the template concentrations was linear according to Poisson probabilities in the range of 0.1-1,000 aM. These results demonstrate the amplification of single templates in the channels, and that a small number of templates could be quantified by counting the proportion of positive channels on the capillary-plates.

Fluorometric assay of DNA binding proteins using class IIS endonuclease

Fluorometric DNA-protein binding assay was developed with class IIS restriction enzyme and FITC-labeled DNA fixed on magnetic beads. We used this assay with AP1 and FokI as a case study to quantify DNA-protein binding. Fluorescent images of the treated beads showed that the transcriptional factor bound to its DNA site and inhibited the restricted digestion effectively. The affinity of AP1 to its site was estimated as a Kd value, which was approximately 10 nM.

Direct association of TSLC1 and DAL-1, two distinct tumor suppressor proteins in lung cancer

The tumor suppressor gene TSLC1, which we recently identified in human non-small cell lung cancer, encodes a membrane glycoprotein of the immunoglobulin superfamily. Here, we report that TSLC1 directly associates with DAL-1, a gene product of another lung tumor suppressor belonging to the protein 4.1 family. TSLC1 additionally interacts with the actin filament through DAL-1 at the cell-cell attached site where the complex formation of TSLC1 and DAL-1 is dependent on the integrity of actin cytoskeleton. Redistribution of both TSLC1 and DAL-1 to the newly generated membrane ruffling areas suggests that these proteins are also involved in cell motility accompanying the actin rearrangement. Furthermore, restoration of TSLC1 expression strongly suppressed the metastasis of a human non-small cell lung cancer cell line, A549, from the spleen to the liver in nude mice. These findings, together with frequent loss of their expression in lung cancers, suggest that TSLC1 and DAL-1 play a critical role in the same pathway involved in the suppression of lung tumor formation and metastasis.

Identification of the Tslc1 gene, a mouse orthologue of the human tumor suppressor TSLC1 gene

We have recently identified the TSLC1 gene as a novel tumor suppressor in human non-small lung cancer on chromosome 11q23.2. TSLC1 encodes a membrane glycoprotein showing significant homology with immunoglobulin superfamily molecules. Here, we report the isolation of a mouse orthologous gene, Tslc1. The Tslc1 cDNA contains a single open reading frame of 1335 bp encoding a putative protein of 445 amino acids, and its expression was detected in all tissues examined. The Tslc1 gene is mapped on mouse chromosome 9, a synteny of human chromosome 11q, and is composed of ten exons, the exon-intron junctions being highly conserved between human and mouse. The predicted amino acids of mouse Tslc1 display 98% identity with that of human TSLC1. Furthermore, data base analysis indicates that the amino acid sequences corresponding to the cytoplasmic domain of Tslc1 are identical in five mammals and highly conserved in vertebrates, suggesting an important role of Tslc1 in normal cell-cell interaction.

Promoter methylation of TSLC1 and tumor suppression by its gene product in human prostate cancer

We recently identified TSLC1, a tumor suppressor gene in human lung cancer. Gene silencing by promoter methylation has been observed frequently in adenocarcinoma of the lung, liver, and pancreas. Here, we demonstrate that TSLC1 expression is also absent or markedly reduced in 3 of 4 prostate cancer cell lines. Promoter sequences of TSLC1 were heavily methylated in PPC-1 cells that lacked TSLC1 expression, supporting the idea that promoter methylation is strongly correlated with complete loss of gene expression. Promoter sequences of TSLC1 were also methylated significantly in 7 of 22 (32%) primary prostate cancers. Hypermethylation of the promoter occurred not only in advanced tumors, but also in relatively early-stage tumors. Restoration of TSLC1 expression substantially suppressed tumor formation of PPC-1 cells in nude mice. These findings indicate that alteration of TSLC1 is involved in prostate cancer.