Biomedical subjects

Setsuo Hirohashi

Publications and source records attributed to Setsuo Hirohashi.

At least 55 records · Page 3Linked to original sources

PubMed2005

Protein expression pattern distinguishes different lymphoid neoplasms.

To identify proteins associated with the histological subtypes of lymphoid neoplasms, we studied the proteomes of 42 cell lines from human lymphoid neoplasms including Hodgkin's lymphoma (HL; four cell lines), B cell malignancies (19 cell lines), T cell malignancies (16 cell lines), and natural killer (NK) cell lymphoma (three cell lines). The protein spots were sequentially selected by (i) Wilcoxon or Kruskal-Wallis tests to find the spots whose intensity was significantly (p <0.05) different among the cell line groups, (ii) by statistical-learning methods to prioritize the spots according to their contribution to the classification, and (iii) by unsupervised classification methods to validate the classification robustness by the selected spots. The selected spots discriminated (i) between HL cells and other cells, (ii) between the cells from B cell malignancies, T cell malignancies, and NK cell lymphoma cells, and (iii) between HL cells and anaplastic large cell lymphoma cells. Among the 31 informative protein spots, MS identified 24 proteins corresponding to 23 spots. Previous reports did not correlate these proteins to lymphocyte differentiation, suggesting that a proteomic study would identify the novel mechanisms responsible for the histogenesis of lymphoid neoplasms. These proteins may have potential as differential diagnostic markers for lymphoid neoplasms.

Amino Acid Sequence↗

PubMed2005

Multistep and multicentric development of hepatocellular carcinoma: histological analysis of 980 resected nodules.

BACKGROUND/AIMS: Histological observations support the concept of multistep and multicentric development of hepatocellular carcinoma (HCC) in cases of chronic liver disease. However, the relationship between the incidence of such a modality of development of HCC and the type of background liver disease has not been fully investigated. METHODS: A total of 980 HCC nodules resected from 664 patients were analyzed. Multistep HCC was defined as well differentiated HCC containing the portal tracts (early HCC), or the presence of early HCC-like areas in the periphery of the nodule. In cases with multiple nodules, if the smaller nodule showed the features of multistep HCC, or if each nodule showed a distinct histology, the case was defined to have multicentric HCC. RESULTS: Of the 980 nodules, 369 (37.7%) met the criteria of multistep HCC. Of the 664 patients, 177 (26.7%) had multiple nodules that met the criteria of multicentric HCC. Both the incidences of multistep and multicentric HCC were significantly higher in HCV-Ab-positive cases than in HBs-Ag-positive cases (46.0 vs. 19.1%, P<0.001 and 34.1 vs. 16.5%, P=0.005, respectively). CONCLUSIONS: Multistep and multicentric HCC develops most frequently in patients with HCV infection.

Carcinoma, Hepatocellular↗

PubMed2005

Mutations of the epidermal growth factor receptor gene in atypical adenomatous hyperplasia and bronchioloalveolar carcinoma of the lung.

A hypothesis of multistep carcinogenesis of lung adenocarcinoma from atypical adenomatous hyperplasia (AAH) to invasive adenocarcinoma through bronchioloalveolar carcinoma (BAC) has been proposed. However, the genetic alterations that play a role during these processes are not yet clear. Recently, somatic mutations of the epidermal growth factor receptor (EGFR) gene were found in lung adenocarcinoma. We examined the status of EGFR mutations in AAH and BAC to elucidate the role they play during multistage of lung adenocarcinoma. We found somatic EGFR mutations in 3% (1/35) of AAH, 10.8% (4/37) of BAC and 41.9% (13/31) of invasive adenocarcinoma. Sixteen of 18 EGFR mutations were found in exon 19 and two were in exon 21. Among the 16 EGFR mutations in exon 19, 13 were deletions of 15bp and one was an insertion/duplication of 18bp. Mutations of the K-ras gene were detected in 26.7% (8/30) of AAH, 16.7% (5/30) of BAC and 10% (3/30) of invasive adenocarcinoma. None of the tumors with EGFR mutations had K-ras mutation simultaneously. Patients who had invasive adenocarcinoma with EGFR mutations were younger than those without mutations (60.6 versus 67.4 years, p=0.03). These results suggest that tumors with EGFR mutations may progress more rapidly and develop into invasive cancer faster than those without mutations. Alternatively it is also possible that some invasive adenocarcinomas with EGFR mutations may not follow the AAH-adenocarcinoma sequence. We analyzed 24 patients with multiple lung lesions and 13 patients had at least one lesion that had either an EGFR or K-ras mutation. In all cases each lesion had a different mutation status. This finding suggests that the genetic alterations responsible for the development of lung adenocarcinoma occur randomly even under exposure to the same carcinogen.

Adenocarcinoma↗

PubMed2005

Loss of blood group A antigen expression in bladder cancer caused by allelic loss and/or methylation of the ABO gene.

Loss of ABO blood group antigen expression has been reported in transitional cell carcinoma (TCC) of the bladder. Synthesis of the ABO blood group antigen was genetically determined by allelic variants of the ABO gene assigned on 9q34.1. We analyzed loss of heterozygosity (LOH) and promoter hypermethylation of the ABO gene in TCC and compared them with alterations of A antigen expression in TCC, dysplasia and normal urothelium. A total of 81 samples of TCC of the bladder obtained from transurethral resection (TUR) (n=44) and radical cystectomy (n=37) were examined. Expression of the A antigen was evaluated by immunohistochemical staining (IHC) using anti-A antigen monoclonal antibody. LOH of the ABO gene locus was examined by blunt-end single-strand DNA conformational polymorphism (SSCP) analysis using flouresence-based auto sequencer. Promoter hypermethylation of the ABO gene were examined by bisulfite PCR-SSCP (BiPS) analysis and/or methylation-specific PCR (MSP). Loss of A allele and/or hypermethylation were significantly associated with abnormal expression of the A antigen in cases undergoing TUR (P=0.02) and radical cystectomy (P=0.0005). For the analysis of the concomitant dysplasia in 23 cases with TCC of the bladder, the expression of the A antigen was maintained, regardless of the A allelic loss or methylation status in the tumor. In conclusion, A allelic loss and hypermethylation in the promoter region of the ABO gene showed significant correlation with reduction of A antigen expression in TCC, while the expression of the A antigen is maintained in concomitant dysplasia or normal urothelium, suggesting that loss of the ABO gene and/or its promoter hypermethylation is a specific marker for TCC.

ABO Blood-Group System↗

PubMed2005

Actinin-4 increases cell motility and promotes lymph node metastasis of colorectal cancer.

BACKGROUND & AIMS: Enhanced motility of cancer cells by remodeling of the actin cytoskeleton seems crucial in the process of cancer invasion and metastasis. We previously identified an actin-binding protein, actinin-4, as a new biomarker of cancer invasion and an indicator of prognosis for patients with breast cancer. However, its involvement in the mechanisms of cancer invasion and metastasis remains undetermined. The current study tested the role of actinin-4 in the motility and metastatic potential of colorectal cancer cells. METHODS & RESULTS: Quantitative immunofluorescence histochemistry showed that the expression level of the actinin-4 protein was increased in 73.1% (19/26) of the cases of colorectal cancer over the corresponding normal intestinal epithelium. The increased expression of actinin-4 was most significant in dedifferentiated cancer cells at the invasive front. A colorectal cancer cell clone capable of inducing actinin-4 using the tetracycline-regulatory system (designated DLD1 Tet-off ACTN-4) was established. Upon the induction of actinin-4, DLD1 Tet-off ACTN-4 cells spread filopodia and significantly increased their motility ( P = .00027); actinin-4 protein was concentrated at the leading edges of these actin-rich podia. When injected into the mesocecum of severe combined immunodeficient mice, DLD1 Tet-off ACTN4 cells, but not the control cells, metastasized into regional mesenteric lymph nodes, resembling the behavior of clinical cancers. The expression of actinin-4 in focally dedifferentiated cancer cells at the invasive front was significantly correlated with the frequency of lymph node metastasis of colorectal cancer ( P = .038). CONCLUSIONS: Actinin-4 actively increases cell motility and promotes lymph node metastasis of colorectal cancer.

Actinin↗

PubMed2005

Poly(ADP-ribose) polymerase-1 is a component of the oncogenic T-cell factor-4/beta-catenin complex.

BACKGROUND & AIMS: T-cell factor (TCF)-4 regulates a certain set of genes related to growth and differentiation of intestinal epithelial cells. Aberrant transactivation of these TCF-4-regulated genes by beta-catenin protein plays a crucial role in early intestinal carcinogenesis, and the transcriptional machinery of the TCF-4/beta-catenin complex is likely to contain targets for molecular therapy. We explored the molecular composition of the TCF-4/beta-catenin transcriptional complex by means of proteomics. METHODS & RESULTS: A protein of approximately 112 kilodaltons was consistently coimmunoprecipitated with FLAG-tagged TCF-4 transiently expressed in HEK293 cells, and the protein was identified by mass spectrometry as poly(ADP-ribose) polymerase-1 (PARP-1). PARP-1 physically interacted with TCF-4 and augmented the transcriptional activity of the beta-catenin/TCF-4 complex. Knockdown of PARP-1 by RNA interference significantly suppressed both transcriptional activity and proliferation by colorectal cancer cells. Auto-polyADP-ribosylation of the PARP-1 protein induced by DNA damage inhibited the functional interaction of PARP-1 with TCF-4. PARP-1 was overexpressed in the intestinal adenomas of patients with familial adenomatous polyposis and multiple intestinal polyposis mice. The expression of PARP-1 was closely associated with the accumulation of beta-catenin and with the undifferentiated status of intestinal epithelial cells. CONCLUSIONS: In this study, we identified PARP-1 as a novel coactivator of the beta-catenin/TCF-4 complex. Although PARP-1 has been believed to play a protective role against carcinogenesis, these expression patterns and functional properties of PARP-1 were highly suggestive of its participation in early colorectal carcinogenesis.

Cell Transformation, Neoplastic↗

PubMed2005

Beta-catenin interacts with the FUS proto-oncogene product and regulates pre-mRNA splicing.

BACKGROUND & AIMS: beta-Catenin is a downstream effector of the Wnt signaling pathway and is believed to exert its oncogenic function by activating T-cell factor (TCF)/lymphoid enhancer factor (LEF) family transcriptional factors. However, it is still uncertain whether the diverse effects of beta-catenin are caused solely by aberrant gene transactivation. In this study, we used a proteomics approach to obtain further insight into the functional properties of nuclear beta-catenin. METHODS: The protein assembly of a native beta-catenin-containing complex in nuclear extracts from a colorectal cancer cell line, DLD-1, was identified using immunoprecipitation and mass spectrometry. RESULTS: beta-Catenin physically interacted with fusion (FUS)/translocated in liposarcoma (TLS) and various RNA-binding proteins. The expression of FUS/TLS was closely associated with the accumulation of beta-catenin and with the undifferentiated status of intestinal epithelial cells. The transient transfection of FUS suppressed beta-catenin-evoked gene transactivation of TCF/LEF, and beta-catenin transfection affected the splicing pattern of the E1A minigene and induced a novel splicing variant of estrogen receptor (ER)-beta exerting a dominant-negative activity. CONCLUSIONS: Human cancer expresses a large variety of alternatively spliced messenger RNA (mRNA), but the precise molecular mechanisms responsible for cancer-related alternative splicing are largely unknown. In this study, we demonstrated the interaction of beta-catenin with FUS/TLS and other RNA-binding proteins involved in the regulation of pre-mRNA splicing. Certain mRNA splicing abbreviations seen in human cancers may be induced by the activation of the Wnt signaling pathway.

Alternative Splicing↗

PubMed2005

DNA hypomethylation on pericentromeric satellite regions significantly correlates with loss of heterozygosity on chromosome 9 in urothelial carcinomas.

PURPOSE: DNA methylation has important roles in genomic stability. Accordingly DNA hypomethylation on pericentromeric satellite regions may induce chromosomal instability through heterochromatin decondensation and chromosomal recombination enhancement. We elucidated the significance of aberrant DNA methylation on pericentromeric satellite regions during urothelial carcinogenesis. MATERIALS AND METHODS: We examined DNA methylation status on satellites 2 and 3 by Southern blotting and determined the allelic status of chromosome 9 using 6 microsatellite markers (D9S775, D9S925, D9S304, D9S303, D9S283 and D9S747) in 27 transitional cell carcinomas of the bladder, ureter or renal pelvis and corresponding noncancerous tissues. RESULTS: DNA hypomethylation on satellites 2 and 3 was detected in 2 (7%) and no (0%) noncancerous tissues, and in 11 (41%) and 12 (44%) urothelial carcinomas, respectively. DNA hypomethylation in urothelial carcinomas significantly correlated with histological grade (p = 0.0012 and 0.0043), invasion depth (p = 0.0055 and 0.0228) and morphological structure (papillary vs nodular, p = 0.0161 and 0.0297) for satellites 2 and 3, respectively. Loss of heterozygosity on at least 1 locus of chromosome 9 was detected in 14 urothelial carcinomas (52%). DNA hypomethylation on satellites 2 (p = 0.0098) and 3 (p = 0.0034) significantly correlated with loss of heterozygosity on chromosome 9. CONCLUSIONS: DNA hypomethylation on pericentromeric satellite regions may participate in the development and progression of urothelial carcinomas by inducing loss of heterozygosity on chromosome 9.

Aged↗

PubMed2005

DNA hypermethylation on multiple CpG islands associated with increased DNA methyltransferase DNMT1 protein expression during multistage urothelial carcinogenesis.

PURPOSE: We elucidated the significance of aberrant DNA methylation on multiple CpG islands and its correlation with DNA methyltransferase DNMT1 protein expression during urothelial carcinogenesis. MATERIALS AND METHODS: We examined the DNA methylation status on multiple CpG islands by methylation specific polymerase chain reaction and combined bisulfite restriction enzyme analysis in 12 specimens of normal urothelium, 23 of noncancerous urothelium showing no remarkable histological changes obtained from patients with bladder cancer (NBC) and 70 of transitional cell carcinoma (TCC). RESULTS: DNA methylation on CpG islands of the p16 (0%, 17% and 21%) and death-associated protein kinase (13%, 33% and 29%) genes, and methylated in tumor-2 (56%, 60% and 76%), 12 (0%, 6% and 30%), 25 (25%, 27% and 35%) and 31 (45%, 56% and 79%) clones was detected in normal urothelium, NBCs and TCCs, respectively. The incidence of concurrent DNA hypermethylation on 3 or more CpG islands in NBCs (38%) was significantly higher than that in normal urothelium (0%, p = 0.0455) and even higher in TCCs (59%, p = 0.0043). The incidence of the CpG island methylator phenotype in nonpapillary carcinomas (nodular invasive carcinomas and their precursors, ie flat carcinoma in situ, 71%) was significantly higher than in papillary carcinomas (40%, p = 0.0143). In all specimens examined concurrent DNA hypermethylation on 3 or more CpG islands significantly correlated with immunohistochemically evaluated DNMT1 protein over expression (p = 0.0167). CONCLUSIONS: DNA hypermethylation on multiple CpG islands in association with DNMT1 protein over expression may participate in multistage urothelial carcinogenesis even at the precancerous stage and particularly in the development of nodular invasive carcinomas of the bladder.

Carcinoma, Transitional Cell↗

PubMed2005

Identification of 2 serum biomarkers of renal cell carcinoma by surface enhanced laser desorption/ionization mass spectrometry.

PURPOSE: Surface enhanced laser desorption/ionization mass spectrometry can generate robust information from a small amount of clinical samples such as serum and plasma. In this study we identified novel diagnostic biomarkers of renal cell carcinoma (RCC) by large-scale serum protein profiling using surface enhanced laser desorption/ionization mass spectrometry. MATERIALS AND METHODS: Proteomic spectra were generated by a time of flight mass spectrometer from a set of training samples (21 patients with RCC and 24 healthy volunteers) and another set of validation samples (19 patients with RCC, 20 healthy volunteers and 5 patients with pyelonephritis). Information on the peaks (intensity and m/z) was extracted from the mass spectra using newly developed algorithms, and the Mann-Whitney's U test and linear support vector machine were used to identify the peaks distinguishing RCC samples from the controls. RESULTS: Two peaks with molecular masses of 4,151 and 8,968 m/z were selected as significantly more prominent in RCC samples (p <0.01) among the 3,539 peaks in the range of 3,000 to 30,000 m/z obtained from the training samples. Simultaneous recognition of these 2 biomarkers was shown to have a sensitivity of 89.5% for the diagnosis of RCC and an overall specificity of 80.0% (95% [19 of 20] of healthy volunteers and 20% [1 of 5] of patients with pyelonephritis) in the blinded validation samples, and to allow detection of RCC in stage I (UICC) in 88.9% (16 of 18) of the cases. CONCLUSIONS: We identified 2 serum biomarkers potentially useful for the early diagnosis of RCC. This finding warrants a further large-scale multi-institutional analysis for clinical evaluation of the diagnostic significance of these biomarkers.

Adult↗

PubMed2005

Development and biological analysis of peritoneal metastasis mouse models for human scirrhous stomach cancer.

The number of published studies on peritoneal dissemination of scirrhous gastric carcinoma is very small as a result of the unavailability of highly reproducible animal models. Orthotopic implantation of HSC-44PE and HSC-58 (scirrhous gastric carcinoma-derived cell lines) cells into nude mice led to dissemination of the tumor cells to the greater omentum, mesenterium, peritoneum and so on, and caused ascites in a small number of animals. Cycles of isolation of the ascitic tumor cells and orthotopic inoculation of these cells were repeated in turn to animals. This was to isolate highly metastatic cell lines with a strong capability of inducing the formation of ascites (44As3 from HSC-44PE; 58As1 and 58As9 from HSC-58). All three cell lines induced tumor formation at the site of orthotopic injection, and caused fatal cancerous peritonitis and bloody ascites in 90-100% of the animals approximately 3-5 weeks after the inoculation. When the parent cells were implanted, the animals became moribund in approximately 12-18 weeks, however, none of the animals developed ascites. Complementary DNA microarray and immunohistochemical analyses revealed differences in the expression levels of genes coding for the matrix proteinase, cell adhesion, motility, angiogenesis and proliferation between the highly metastatic- and parent-cell lines. The usefulness of this model for the evaluation of drugs was assessed by analyzing the stability of the metastatic potential of the cells and the reproducibility. Animals intravenously treated with CPT-11 and GEM showed suppressed tumor growth and significantly prolonged survival. The metastatic cell lines and the in vivo model established in the present study are expected to serve as a model of cancerous peritonitis developing from primary lesions, and as a useful means of clarifying the pathophysiology of peritoneal dissemination of scirrhous gastric carcinoma and the development of drugs for its treatment.

Adenocarcinoma, Scirrhous↗

PubMed2005

Frequent KIT and epidermal growth factor receptor overexpressions in undifferentiated-type breast carcinomas with 'stem-cell-like' features.

It was hypothesized that four histopathological types or subtypes of breast carcinoma were undifferentiated types characterized by bidirectional differentiation toward both luminal epithelial and myoepithelial cells and had characteristic molecular changes: invasive ductal carcinoma (IDC) with a large central acellular zone, atypical medullary carcinoma (a subgroup in Grade 3 solid-tubular carcinoma), matrix-producing carcinoma, and spindle-cell carcinoma (or carcinoma with spindle-cell metaplasia). In 32 cases of the undifferentiated type and 37 cases of the relatively differentiated types, we immunohistochemically examined the expressions of myoepithelial markers and KIT, epidermal growth factor receptor (EGFR), and c-erbB-2 oncoproteins. Vimentin, S-100, and alpha-smooth muscle actin were positive in 28 (88%), 22 (69%), and 15 (47%) of the undifferentiated types, but were positive in seven (19%), one (3%), and one (3%) of relatively differentiated types (P < 0.0001). KIT and EGFR overexpressions were detected more frequently in the undifferentiated types (34 and 88%, respectively) than in relatively differentiated types (3 and 3%, respectively) (P < 0.0001, for both). In 11 (85%) of 13 cases with KIT overexpression, EGFR overexpression concurred. c-erbB-2 overexpression was almost equally detected in both the undifferentiated and relatively differentiated types, and did not correlate with KIT or EGFR overexpression. Phosphotyrosine was detected in 16 (67%) of 24 cases with KIT, EGFR, and/or c-erbB-2 overexpression but only in six (18%) of 34 cases without KIT, EGFR, or c-erbB-2 overexpression (P = 0.0002). The undifferentiated-type breast carcinomas appeared to show mammary epithelial stem cell-like features, and they could be identified by KIT and/or EGFR overexpressions.

Biomarkers, Tumor↗

PubMed2005

Increased DNA methyltransferase 1 (DNMT1) protein expression in precancerous conditions and ductal carcinomas of the pancreas.

Aberrant DNA methylation has been shown to play an important role during multistage carcinogenesis in various human organs. The aim of the present study was to evaluate the significance of DNA methyltransferase 1 (DNMT1) protein expression during pancreatic carcinogenesis. Immunohistochemical analysis of DNMT1 in 48 peripheral pancreatic duct epithelia showing no remarkable histological findings without an inflammatory background (DE), 54 peripheral pancreatic duct epithelia with an inflammatory background (DEI), 188 pancreatic intraepithelial neoplasias (PanIN), and 220 areas of invasive ductal carcinoma from surgical specimens resected from 100 patients, was carried out. The average incidence of DNMT1 immunoreactivity increased progressively from DE to DEI (P = 0.003), from DE and DEI to PanIN (P < 0.0001), among PanIN with different grades of dysplasia (from PanIN I to PanIN II, P = 0.0012), from PanIN to invasive ductal carcinomas (P < 0.0001) and among invasive ductal carcinomas with different grades of histological differentiation (from well or moderately to poorly differentiated adenocarcinomas, P < 0.0001). High-level DNMT1 protein expression in invasive ductal carcinomas was correlated significantly with an advanced t category (P = 0.0224) and an advanced stage (P = 0.0294). Moreover, patients with invasive ductal carcinomas showing high-level DNMT1 protein expression had a poorer outcome (P = 0.0469). These data suggest that increased DNMT1 protein expression participates in multistage pancreatic carcinogenesis from the precancerous stage to malignant progression of ductal carcinomas and may be a biological predictor of poor prognosis.

Adult↗

PubMed2005

Array-based comparative genomic hybridization analysis of high-grade neuroendocrine tumors of the lung.

We examined a large number of primary high-grade neuroendocrine tumors of the lung (10 small cell lung carcinomas and 31 large cell neuroendocrine carcinomas) by using array-based comparative genomic hybridization using microarrays spotted with 800 bacterial artificial chromosome clones containing tumor-related genes from throughout the human genome. We identified the genome-wide copy number alteration profiles of these tumors, including recurrent amplifications located at 2q21.2, 3q21-27, 3q26, 3q27-29, 5p14.2, 5p13, 7q21.1, 8q21, and 8q24 and homozygous deletions at 1p36, 4p16, 4p16.3, 9p21.3, 9p21, 19p13.3, and 20q13. Our results revealed that small cell lung carcinomas and large cell neuroendocrine carcinomas have multiple characteristic chromosomal alterations in common, but that distinctive alterations also exist between the two subtypes. Moreover, we found that the two subtypes undergo different processes of accumulating these genetic alterations during tumor development. By comparing the genetic profiles with the clinicopathological features, we discovered many chromosomal loci whose alterations were significantly associated with clinical stage and patient prognosis. These results will be valuable for evaluating clinical status, including patient prognosis, and for identifying novel molecular targets for effective therapies.

Carcinoma, Small Cell↗

PubMed2004

Dysadherin expression facilitates cell motility and metastatic potential of human pancreatic cancer cells.

Dysadherin is a membrane glycoprotein expressed strongly in several human cancers. Overexpression of dysadherin in tumor cells is closely associated with malignant phenotype (e.g., metastasis) and poor prognosis. In our analysis, six pancreatic cancer cell lines showed a positive correlation between dysadherin expression and cell motility. Introduction of small interfering RNA (siRNA) against dysadherin into the Panc-1 cell line caused reduction of dysadherin expression and suppression of cell motility. In contrast, stable transfection of a dysadherin expression vector into the Capan-1 cell line increased cell motility. In vivo, the metastatic potential of orthotopically transplanted Capan-1 tumor cells in severe combined immunodeficient mice was increased by dysadherin overexpression. Cell morphology and actin organization were also influenced by modulation of dysadherin expression. Cells transfected with dysadherin siRNA tended to have a relatively larger, more spread shape and increased transverse actin stress fibers compared with parent cells and cells transfected with control siRNA. Our study suggests that dysadherin is able to modulate actin structures, stimulate cell motility, and contribute directly to the metastatic potential of human pancreatic cancer cells.

Actins↗

PubMed2004

Reduced expression of liver-intestine cadherin is associated with progression and lymph node metastasis of human colorectal carcinoma.

Liver-intestine cadherin (LI-cadherin) is a recently identified member of the cadherin superfamily. We examined LI-cadherin expression in four human colorectal carcinoma cell lines and 45 human primary colorectal carcinomas using a monoclonal antibody against LI-cadherin. We also investigated the correlation between LI-cadherin expression and clinicopathologic parameters. Among the cell lines, LI-cadherin expression was detected in a differentiated phenotype, but not in dedifferentiated phenotypes. Among the 45 tumor samples, LI-cadherin expression was preserved in 28 (62%) and reduced in 17 (38%). Reduced LI-cadherin expression was significantly associated with a high tumor grade (P = 0.015), lymphatic invasion (P = 0.033), lymph node metastasis (P = 0.015), and an advanced pTNM stage (P = 0.033). These results suggest that analysis of LI-cadherin expression may help to indicate the biological aggressiveness of this malignancy.

Aged↗

PubMed2004

Alterations in gene expression associated with the overexpression of a splice variant of DNA methyltransferase 3b, DNMT3b4, during human hepatocarcinogenesis.

PURPOSE: Overexpression of a splice variant of DNA methyltransferase 3b, DNMT3b4, correlates significantly with DNA hypomethylation in pericentromeric satellite regions, which is known to result in centromeric decondensation and enhanced chromosomal recombination in precancerous conditions and hepatocellular carcinomas (HCCs). We aimed to elucidate further the significance of DNMT3b4 during human hepatocarcinogenesis. METHODS: DNMT3b4-transfected human epithelial 293 cells were characterized using growth rate measurements, gene expression microarray, and quantitative reverse transcription-polymerase chain reaction (RT-PCR) analyses. RT-PCR was also performed on eight normal liver specimens, 45 noncancerous liver specimens showing chronic hepatitis or cirrhosis, which are considered to be precancerous conditions, and 56 HCCs. RESULTS: The growth rate of the DNMT3b4 transfectants was about double that of mock-transfectants. Induction of signal transducer and activator of transcription 1 (STAT1), an effector of interferon signaling, and of a set of downstream genes implicated in such signaling, was observed in the DNMT3b4 transfectants. There was significant correlation between the mRNA expression levels of DNMT3b4 and STAT1 in HCCs. mRNA expression levels of STAT1 and the three downstream genes examined were all significantly elevated in the chronic hepatitis and cirrhosis specimens compared with the normal liver specimens. Among the HCCs, the mRNA expression levels of STAT1 and the downstream genes were higher in tumors without portal vein involvement than in more malignant HCCs with portal vein involvement. Significant correlations between the mRNA expression levels of STAT1 and each of the downstream genes were observed in the tissue samples. CONCLUSIONS: Overexpression of DNMT3b4 is involved in human hepatocarcinogenesis, even at the precancerous stages, not only by inducing chromosomal instability but also by affecting the expression of specific genes.

Carcinoma, Hepatocellular↗

PubMed2004

Alternative splice variant of actinin-4 in small cell lung cancer.

Tumor-associated alternative RNA splicing has gained considerable attention. We identified a novel alternative splice variant RNA of actinin-4 in human small cell lung cancer (SCLC). Expression of the splice variant was highly specific to SCLC cell lines (10/10), biopsies (3/3), and testis. The variant encoded a peptide with a three amino-acid change in exon 8, where the germline missense mutation takes place in familial focal segmental glomerulosclerosis (FSGS). The variant protein showed high affinity to filamentous actin polymers and was not localized with cortical actin. Alternatively spliced actinin-4 may be a new diagnostic marker of SCLC and a candidate target for selective therapy.

Actinin↗