Biomedical subjects

Yoshihiko Hoshida

Publications and source records attributed to Yoshihiko Hoshida.

At least 37 records · Page 2Linked to original sources

PubMed2004

Elevated expression of valosin-containing protein (p97) is associated with poor prognosis of prostate cancer.

PURPOSE: Valosin-containing protein (VCP) has been shown to be associated with metastasis and prognosis in human cancers. In the present study, the correlation of VCP with recurrence and prognosis in patients with prostate cancer (PCA) receiving conservative therapy was examined. EXPERIMENTAL DESIGN: VCP expression was analyzed immunohistochemically in 136 patients ranging from 46 to 92 years (median, 72 years), who received conservative therapy, including androgen deprivation, radiotherapy, or watchful waiting. Staining intensity of tumor cells was categorized as weaker (level 1) or equal to or stronger (level 2) than that in endothelial cells. The correlation of VCP expression between the mRNA and protein levels was examined in 10 patients. RESULTS: Thirty-two cases (23.5%) showed level 1 and 100 (76.5%) level 2 VCP expression. Quantitative reverse transcription-PCR analysis revealed greater VCPmRNA expression in level 2 (n = 5) than level 1 cases (n = 5; P < 0.05). A significant difference was observed between VCP level 1 and 2 patients in the positive rate for the digital rectal examination (P < 0.01), serum prostate-specific antigen level (P < 0.0001), cancer volume (P < 0.0001), Gleason score (P < 0.0001), stage (P < 0.0001), and progression-free and overall survival (P < 0.0001 for both). Multivariate analysis revealed VCP expression level, serum prostate-specific antigen level, and Gleason score to be independent prognosticators for progression-free and overall survival. Progression of PCA was found in 9.4% of level 1 but in 64% of level 2 patients. CONCLUSIONS: PCA with level 1 VCP expression could be treated conservatively.

Adenosine Triphosphatases↗

PubMed2004

Prognostic significance of activated Akt expression in pancreatic ductal adenocarcinoma.

PURPOSE: Akt is a serine/threonine kinase that plays a central role in tumorigenesis. Among the members of Akt family, Akt2 is associated with the development of human cancers. The present study was designed to clarify the prognostic significance of Akt2 and activated Akt expression in pancreatic ductal adenocarcinoma (PDAC). In addition, activated extracellular signal-regulated kinase 1 and 2 (ERK1/2) and the proliferation activity of tumor cells detected by Ki-67 immunohistochemistry were examined. EXPERIMENTAL DESIGN: Immunohistochemical analysis was performed on paraffin-embedded specimens from 65 patients with PDAC; 36 males and 29 females with ages ranging from 48 to 79 years (median, 66 years) of age. Expression levels of Akt2, phosphorylated Akt (p-Akt), and phosphorylated ERK 1/2 (p-ERK 1/2) were categorized as either weaker (low intensity) or equal to stronger (high intensity) compared with those in the endothelial cells of the same specimens. For Ki-67 immunohistochemistry, cases were divided into two groups: level 1, Ki-67 labeling index (LI), <20%; level 2, Ki-67 LI, > or = 20%. RESULTS: Twenty-six (42.6%), 28 (45.9%), 39 (63.9%), and 46 (75.4%) of the tumors showed high intensity of Akt2, p-Akt, and p-ERK 1/2 expression, and Ki-67 LI level 2, respectively. A significant positive correlation was observed between Akt2 and p-Akt expression (P < 0.01). Multivariate analysis revealed that p-Akt expression, Ki-67 LI, and histological differentiation are independent prognosticators for PDAC. CONCLUSIONS: p-Akt expression is a significant prognostic indicator for PDAC. Inhibition of Akt is a possible molecular approach for treatment of PDAC.

Adenocarcinoma↗

PubMed2004

WT1 peptide vaccination combined with BCG-CWS is more efficient for tumor eradication than WT1 peptide vaccination alone.

A Wilms' tumor gene WT1 is expressed at high levels not only in most types of leukemia but also in various types of solid tumors, including lung and breast cancer. WT1 protein has been reported to serve as a target antigen for tumor-specific immunotherapy both in vitro in human systems and in vivo in murine models. We have shown that mice immunized with WT1 peptide or WT1 cDNA could reject a challenge from WT1-expressing tumor cells (a "prophylactic" model). However, it was not examined whether WT1 peptide vaccination had the potency to reject tumor cells in a "therapeutic" setting. In the present study, we demonstrated for the first time that WT1 peptide vaccination combined with Mycobacterium bovis bacillus Calmette-Guérin cell wall skeleton (BCG-CWS) was more effective for eradication of WT1-expressing tumor cells that had been implanted into mice before vaccination (a "therapeutic" model) compared with WT1 peptide vaccination alone. An intradermal injection of BCG-CWS into mice, followed by that of WT1 peptide at the same site on the next day, generated WT1-specific cytotoxic T lymphocytes (CTLs) and led to rejection of WT1-expressing leukemia or lung cancer cells. These results showed that BCG-CWS, which was well known to enhance innate immunity, could enhance WT1-specific immune responses (acquired immunity) in combination with WT1 peptide vaccination. Therefore, WT1 peptide vaccination combined with BCG-CWS may be applied to cancer immunotherapy in clinical settings.

Animals↗

PubMed2004

Lymphoproliferative disorders in autoimmune diseases in Japan: analysis of clinicopathological features and Epstein-Barr virus infection.

Lymphoproliferative disorders (LPD) occasionally develop in individuals with immune deficiencies such as immunosuppressive conditions and autoimmune diseases (AID). In our study, the clinicopathologic features and virus status were analyzed in 53 cases with LPD developing in rheumatoid arthritis (RA) and other AID. AID in only 4 of 53 patients had been treated with some sort of immunosuppressive therapy, including methotrexate. Median age at the diagnosis of LPD in AID was 60 years old with marked female predominance (M/F = 0.4). The median interval between the onset of AID and LPD development was 45 months, and longer in RA patients than in other AID (p < 0.01). The primary site of lymphoma was nodal in 21 cases and extra-nodal in 24, with clinical Stage I in 17, II in 5, III in 13, and IV in 13. Immunohistochemistry showed that 39 cases were B cell type, 10 were T cell type and 4 were Hodgkin lymphoma (HL). Then majority of B cell cases were diffuse large B cell lymphomas, and 2 were diffuse polymorphic type. EBER-1 in situ hybridization for Epstein-Barr virus (EBV) showed positive signals in tumor cells in 16 of 53 (30.2%) cases. The EBV-positive rate in T cell LPD (70%) was much higher than that in B cell LPD (12.8%) (p < 0.01). All 4 cases of HL were EBV-positive. Immunohistochemistry showed a latency II pattern of EBV infection (LMP-1(+) and EBNA-2(-)). Five-year overall survival rate was 33%. Multivariate analysis showed that only type of AID was an independent factor for survival of patients, i.e., LPD in RA showed the most favorable prognosis. In conclusion, LPD in AID generally shared common features with sporadic LPD except for a much higher EBV-positive rate in T cell LPD.

Adult↗

PubMed2004

Expression of valosin-containing protein in colorectal carcinomas as a predictor for disease recurrence and prognosis.

PURPOSE: Valosin-containing protein (VCP or p97) is associated with antiapoptotic function and metastasis via activation of the nuclear factor-kappaB signaling pathway. The present study was designed to investigate the prognostic significance of VCP expression in colorectal adenocarcinoma. EXPERIMENTAL DESIGN: We analyzed VCP expression immunohistochemically in 129 patients with colorectal carcinoma ages 35-84 years. The staining intensity of tumor cells was categorized as either weaker-to-equal (low VCP expression) or stronger (high expression) than that in noncancerous colonic mucosa. We also analyzed 8 colorectal adenomas and 10 metastatic foci. RESULTS: Low VCP expression was noted in 41 (31.8%) cases and high expression in 88 (68.2%) cases. A low level of VCP expression was noted in all adenomas, whereas a high level was seen in all metastatic tumors. A significant difference was observed in depth of invasion (T(1-2) versus T(3-4), P < 0.05), presence or absence of venous invasion (P < 0.05), and tumor stage (I and II versus III and IV; P < 0.05) between adenocarcinomas with low and high VCP expression. Patients with high VCP-expressing tumors had a higher recurrence rate (P < 0.001) and poorer disease-free and overall survival (P < 0.01 and P < 0.05, respectively) compared with the low expression group. Multivariate analysis revealed VCP expression level to be an independent prognosticator for both disease-free and overall survival. VCP level was an indicator of disease-free survival in both stage II and III (pathological Tumor-Node-Metastasis classification, P < 0.05 and <0.01, respectively). CONCLUSIONS: A high expression level of VCP in tumors is a poor prognostic marker in patients with colorectal carcinomas.

Adenoma↗

PubMed2004

Interstitial pneumonia induced by combined intraarterial 5-fluorouracil and subcutaneous interferon-alpha therapy for advanced hepatocellular carcinoma.

Previously we reported combined chemo-immunotherapy, using interferon (IFN)-alpha and 5-fluorouracil (5-FU) for patients with advanced hepatocellular carcinoma (HCC), and this regimen improved the prognosis. Recently, we experienced an HCC patient who died of severe interstitial pneumonia during the combined IFN-alpha and 5-FU therapy. This is the first report of the occurrence of interstitial pneumonia during combined IFN-alpha and 5-FU treatment. A 60-year-old-man was admitted to Osaka University Hospital to receive systemic chemo-immunotherapy for recurrent HCC. In the second week of the chemo-immunotherapy, he showed a decreased level of consciousness, and respiratory insufficiency. Emergency roentgenogram revealed diffuse infiltration in both lungs. Respiratory dysfunction due to interstitial pneumonia was suspected, and steroid pulse therapy was started. However, the patient showed respiratory failure, and he died 32 days after the start of the therapy. Autopsy findings showed atelectasis in the bilateral lungs, which showed elastic hard solidity and a dark red color; esophageal varices were also shown, and there was cirrhosis with a large tumor in the liver. Microscopically, the alveolar wall showed marked fibrous thickness and moderate inflammatory change, which is consistent with acute interstitial pneumonia, and the acute pulmonary change was suspected to have been the cause of death. The association of IFN with the development of interstitial pneumonia has been reported. However, the prognosis of IFN-induced interstitial pneumonia has mostly been favorable when the medication was discontinued. It has been postulated that interstitial pneumonia induced by the combination of IFN and 5-FU may be therapy-resistant. The combination of IFN-alpha and 5-FU is a useful therapy for patients with advanced HCC, such as that with portal vein invasion or multiple metastatic foci. Thus, interstitial pneumonia in these patients should be carefully managed.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2004

Distinct pattern of gene expression in pyothorax-associated lymphoma (PAL), a lymphoma developing in long-standing inflammation.

Pyothorax-associated lymphoma (PAL) is a unique lymphoma developing in the pleural cavity after long-standing pyothorax. They are diffuse large B-cell lymphomas (DLBCLs), frequently with immunoblastic morphology, and show a strong association with Epstein-Barr virus (EBV) infection. In this study, cDNA microarray analysis was performed in six cases with PAL and 12 with nodal DLBCL. Among 5516 informative genes, 348 displayed more than 2-fold difference (higher or lower) of expression level between PAL and nodal DLBCL (P < 0.001). These genes are known to be involved in apoptosis, interferon response, and signal transduction. One of the most differentially expressed genes, IFI27 (interferon-alpha-inducible protein 27) was subjected to quantitative RT-PCR analysis, and increased expression of IFI27 was confirmed. Overexpression of IFI27 was also found in cell lines derived from PAL, but not in other lymphoid cell lines. This study shows that PAL is a distinctive subtype of DLBCL not only in its clinical presentation, but also in its molecular profile.

Adult↗

PubMed2004

Malignancies in organ transplant recipients.

The development of cancer in organ transplant recipients is well known; depressed immunosurveillance induced by the use of immunosuppressive agents for prevention of rejection is a causative factor. The types of malignancies in renal transplant patients vary geographically and are influenced by the type of immunosuppressant used. In the present study in Japan, malignancies had developed in 2.6% of renal transplant recipients; the observed number/expected number ratio was 2.78. For the primary sites, the relative risk in Japan was quite different from that in Western countries, with a lower frequency of skin cancer, an absence of Kaposi's sarcoma and higher frequencies of renal and thyroid cancer in Japan. Epstein-Barr virus is an oncogenic virus causing lymphoproliferative disorders in immunocompromised hosts. In renal transplant recipients, who usually receive hemodialysis before transplantation, human T lymphotrophic virus (HTLV)-1 is also oncogenic and causes adult T-cell leukemia/lymphoma. The HTLV-1 in donor blood might be transmitted to transplant recipients via transfusion during hemodialysis. The epidemiology and characteristics of representative malignancies in transplant recipients are described, with a review of pertinent literature.

Adult↗

PubMed2004

Expression of uridine diphosphate N-acetyl-alpha-D-galactosamine: polypeptide N-acetylgalactosaminyl transferase 3 in adenocarcinoma of the pancreas.

Uridine diphosphate (UDP) N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyl transferase 3 (GalNAc-T3), one of the enzymes that catalyze the initial glycosylation of mucin type O-linked proteins, was shown to associate with the differentiation of cancer cell lines and the prognosis of some kinds of cancers. In the present study, the association of GalNAc-T3 expression with clinicopathologic features of pancreatic adenocarcinoma and patients' survival was examined. The level of expression of GalNAc-T3 was analyzed immunohistochemically in paraffin-embedded tumor samples from surgically resected specimens of 59 patients with pancreatic ductal adenocarcinoma. The correlations of GalNAc-T3 expression with clinicopathologic features and prognosis were studied. Thirty-five tumors showed high- intensity GalNAc-T3 staining, whereas 24 showed low-intensity staining. A close association was observed between GalNAc-T3 staining intensity and histologic differentiation and the stage of the tumors. The low-intensity group showed a high rate of the poorly differentiated subtype (p < 0.001) and T4 of the pTNM staging system (p < 0.05). These findings indicate that the expression of GalNAc-T3 is associated with the differentiation and aggressiveness of ductal adenocarcinoma of the pancreas.

Aged↗

PubMed2004

Valosin-containing protein (p97) and Ki-67 expression is a useful marker in detecting malignant behavior of pancreatic endocrine neoplasms.

OBJECTIVE: To determine the prognostic value of valosin-containing protein (VCP) expression and the Ki-67 labeling index (LI) in pancreatic endocrine neoplasms (PENs), the present analysis was employed. METHODS: The Ki-67 LI and VCP expression at the mRNA and protein level were evaluated in 32 patients (12 male and 20 female) with PENs aged from 22 to 73 years (median 49 years). VCP staining intensity in tumor cells was categorized as weaker (level 1) or equal to stronger (level 2) compared to nontumorous islet cells. Ki-67 LI was divided into two categories: level 1, Ki-67 LI < 5%, and level 2, > or = 5%. RESULTS: Five cases (15.6%) showed level 1 and 25 (84.4%) level 2 VCP expression by immunohistochemistry. A significant association was observed between VCP expression and the malignant behavior of PENs (p < 0.01). All level 1 VCP tumors were benign PENs. Quantitative reverse transcription polymerase chain reaction analysis showed higher VCP mRNA expression in malignant PENs (n = 5) than benign cases (n = 5) (p < 0.05). For Ki-67 LI, 28 cases (87.5%) showed level 1 and 4 (12.5%) level 2 expression. All patients with level 2 Ki-67 LI had metastasis. CONCLUSION: VCP expression analysis and Ki-67 LI are useful prognosticators for PENs.

Adenosine Triphosphatases↗

PubMed2004

Increased expression of valosin-containing protein (p97) is associated with lymph node metastasis and prognosis of pancreatic ductal adenocarcinoma.

BACKGROUND: Valosin-containing protein (VCP, also known as p97) exhibits antiapoptotic function and metastasis by activation of nuclear factor kappa-B signaling pathway. Our previous study showed that VCP expression level correlated with prognosis of hepatocellular and gastric carcinoma. In the present study, association of VCP expression with lymph node metastasis and prognosis of pancreatic ductal adenocarcinoma (PDAC) was examined. METHODS: VCP expression in 83 patients (46 males and 37 females) of ages ranging from 43 to 80 (median, 66) years who had undergone curative surgery for primary PDAC was analyzed by immunohistochemistry, in which staining intensity in tumor cells was categorized as weaker or equal to (low expression) or stronger (high expression) than that in noncancerous ductal tissue. RESULTS: Thirty-two tumors (38.6%) and 51 tumors (61.4%) were classified as low-VCP-expressing and high-VCP-expressing tumors, respectively. VCP expression correlated significantly with lymph node metastasis (P <.01) but not with various clinicopathologic factors, including age, gender, and histologic differentiation. Multivariate analysis revealed VCP expression as an independent prognosticator for both disease-free and overall survival, along with histologic differentiation, T stage of pathologic tumor-node-metastasis (pTNM) classification, and lymph node metastasis. Furthermore, VCP expression was a prognosticator for disease-free and overall survival in each relatively early stage (I or II) and advanced stage (III) group of pTNM classification. CONCLUSIONS: Our results indicate the potential usefulness of VCP expression as a marker of metastasis and overall prognosis of PDAC.

Adenosine Triphosphatases↗

PubMed2004

Expression level of valosin-containing protein (p97) is correlated with progression and prognosis of non-small-cell lung carcinoma.

BACKGROUND: Valosin-containing protein (VCP; also known as p97) was shown to be associated with antiapoptosis and metastasis via activation of a nuclear factor-kappaB signaling pathway. Our previous study showed that the VCP expression level correlated with the disease recurrence rate and prognosis of patients with hepatocellular carcinoma and gastric carcinoma. This study was designed to evaluate the prognostic significance of VCP expression in non-small-cell lung carcinoma (NSCLC). METHODS: VCP expression in 207 patients with NSCLC (133 men and 74 women) aged 35 to 78 years (median, 62 years) was examined by immunohistochemistry, in which staining intensity in tumor cells was categorized as weaker than (level 1) or equal to or stronger than (level 2) that in endothelial cells. RESULTS: Sixty-nine (33.8%) cases showed level 1 and 135 (66.2%) showed level 2 VCP expression. The frequency of the following was higher in patients with level 2 expression than in those with level 1 expression: male sex (P <.01), histological subtype of squamous cell carcinoma (P <.05), and smoking (P <.05). Patients with level 2 expression had poorer disease-free and overall survival rates (P <.05 and P <.01, respectively) than those with level 1 expression. Multivariate analysis revealed VCP expression and pathologic T (pT) and pN classifications to be independent prognostic factors for both disease-free and overall survival and showed vascular invasion to be an independent prognostic factor for overall survival. VCP level was a prognosticator for overall survival in both the early (pT1) and advanced (pT2-3) group of the pT classification (P <.05 for both). CONCLUSIONS: The prognostic significance of VCP expression in NSCLC was demonstrated.

Adenosine Triphosphatases↗

PubMed2003

Expression level of valosin-containing protein is strongly associated with progression and prognosis of gastric carcinoma.

PURPOSE: Valosin-containing protein (VCP; also known as p97) was shown to be associated with antiapoptotic function and metastasis via activation of nuclear factor kappa-B signaling pathway. In this study, association of VCP expression with recurrence of gastric carcinoma (GC), in which lymphatic vessels are the main route of spread, was examined. PATIENTS AND METHODS: VCP expression in 330 patients with GC (242 males and 88 females) with ages ranging from 26 to 81 years (median, 60 years) was analyzed by immunohistochemistry, in which staining intensity in tumor cells was categorized as weaker (level 1) or equal to or stronger (level 2) than that in endothelial cells. RESULTS: Ninety-four (28.7%) patient cases showed level 1 and 233 patient cases (71.3%) showed level 2 VCP expression. Patients with level 2 expression showed higher rates of large tumor size (P <.0001), undifferentiated histologic subtype (P <.05), presence of vascular and lymphatic invasion (P <.0001 for both), presence of lymph node metastasis (P <.0001), deep tumor invasion (P <.0001), and poorer disease-free and overall survivals (P <.0001 for both) compared with those with level 1 VCP expression. Multivariate analysis revealed VCP expression level as an independent prognosticator for disease-free and overall survival. VCP level was an indicator for disease-free and overall survival in the early (pT1; P <.01 and P <.05, respectively) and advanced (pT2-4; P <.05 for both) group of pathologic tumor-node-metastasis system classification. CONCLUSION: The prognostic significance of VCP expression level in GC was demonstrated.

Adenosine Triphosphatases↗

PubMed2003

Expression of tetraspanins in human lung cancer cells: frequent downregulation of CD9 and its contribution to cell motility in small cell lung cancer.

Small cell lung cancer (SCLC) invades locally and metastasizes distantly extremely early when compared with nonsmall cell lung cancer (NSCLC). The underlying molecular mechanisms, however, have not been elucidated. Accumulating evidence suggests that downregulation of several members of tetraspanins is associated with progression of solid tumors, thus indicating poor prognosis. Here we screened 30 lung cancer cell lines for expression of tetraspanins, CD9, CD63, CD81, CD82, CD151, and NAG-2. Flow cytometry revealed that, among these proteins, CD9 is broadly expressed in NSCLC lines, but is absent or highly reduced in most SCLC lines (P<0.0001). Using the Boyden chamber and videomicroscopic cell motility assays, we showed that stable transfection of CD9 into an SCLC line, OS3-R5, reduced cell motility on fibronectin. Furthermore, by transient transfection of green fluorescent protein (GFP)-tagged CD9 into three other SCLC lines, we observed that SCLC cells expressing GFP-CD9 were uniformly less motile than untransfected cells. CD9 or GFP-CD9 was associated with beta1 integrins and distributed at the tumor cell periphery and cell-cell contacts, suggesting that CD9 modifies beta1 integrin function to reduce motility. These findings suggest that low expression of CD9 may contribute to the highly invasive and metastatic phenotype of SCLC.

Antigens, CD↗

PubMed2003

Elevated expression of valosin-containing protein (p97) in hepatocellular carcinoma is correlated with increased incidence of tumor recurrence.

PURPOSE: Valosin-containing protein (VCP; also known as p97) has been shown to be associated with antiapoptotic function and metastasis via activation of the nuclear factor-kappaB signaling pathway. In this study, association of VCP expression with recurrence of hepatocellular carcinoma (HCC) and patient survival was examined. PATIENTS AND METHODS: VCP expression in 170 patients (139 male and 31 female) with ages ranging from 31 to 81 years (median, 61 years) was analyzed by quantitative reverse-transcription polymerase chain reaction (RT-PCR) and immunohistochemistry, in which staining intensity in tumor cells was categorized as weaker (level 1) or equal to or stronger (level 2) than that in endothelial cells. RESULTS: Immunohistochemically, 57 patients (35.2%) showed level 1, and 105 patients (64.8%) showed level 2, VCP expression. Quantitative RT-PCR analysis revealed higher VCP mRNA expression in level 2 patients (n = 7) than level 1 (n = 4) (P <.05). Patients with VCP-level 2 HCC showed higher rate of portal vein invasion in the tumor (P <.01) and poorer disease-free and overall survival (P <.0001 and P <.05, respectively) compared with level 1 patients. Multivariate analysis revealed VCP expression level, tumor multiplicity, and degree of fibrosis in the noncancerous liver tissue to be independent prognosticators for disease-free and overall survival. VCP level was an indicator for disease-free survival in each early- (I and II) and advanced- (III and IV) stage group of pathologic tumor-node-metastasis classification (P <.001 and P <.01, respectively). CONCLUSION: VCP expression level has prognostic significance for disease-free and overall survival of patients with HCC.

Adenosine Triphosphatases↗

PubMed2003

Cronkhite-Canada syndrome with colon cancer, portal thrombosis, high titer of antinuclear antibodies, and membranous glomerulonephritis.

A 64-year-old man, who came to us with diarrhea, presented with ectodermal changes such as hyperpigmentation, alopecia, and onychatrophy, and was affected by polyposis in the colorectum and stomach. The polyps were histologically consistent with those in Cronkhite-Canada syndrome (CCS). Interestingly, the patient also had colon cancer, as well as portal thrombosis and a high concentration of antinuclear antibody. Treatment with prednisolone ameliorated the symptoms and the gastrointestinal polyposis, while the cancer was successfully treated with a hemicolectomy. Six months after the surgery, the patient developed nephropathy, with nephrotic-range proteinuria, without recurrence of the cancer. The biopsied renal specimen showed membranous glomerulonephritis. This is a rare case of CCS associated with various complications such as colon cancer, portal vein thrombosis, a high titer of antinuclear antibodies, and membranous glomerulonephritis. Although the pathogenesis of CCS is essentially unknown, these complications might have been indicative of an underlying immunological abnormality.

Antibodies, Antinuclear↗

PubMed2003

Hypermethylation of death-associated protein (DAP) kinase CpG island is frequent not only in B-cell but also in T- and natural killer (NK)/T-cell malignancies.

Death-associated protein (DAP) kinase is a pro-apoptotic serine/threonine kinase with a death domain, which is involved in apoptosis induced by interferon-gamma, tumor necrosis factor-alpha, and Fas ligand. Down-regulation of DAP kinase gene expression by hypermethylation of its promoter region might result in resistance to apoptotic cell death, and could provide a basis for tumor development. In the present study, we employed methylation-specific polymerase chain reaction to examine the methylation status of CpG islands in the DAP kinase gene in 19 cases of T-cell malignancies (including eight adult T-cell leukemia/lymphoma), 24 of natural killer (NK)/T-cell, and 34 of B-cell. Frequency of methylation was significantly higher in B-cell (27 of 34, 79.4%) than in T-cell malignancies (nine of 19, 47.4%) (P<0.05). Fifteen of 24 (62.5%) NK/T-cell lymphomas showed DNA methylation. One B-cell lymphoma cell line with DNA methylation was resistant to apoptotic stimuli, and treatment of the cells with a demethylating agent restored apoptotic cell death. These findings suggested that suppression of DAP kinase expression by DNA methylation might play a substantial role in the development of not only B-cell, but also T- and NK/T-cell lymphomas.

Antibodies, Monoclonal↗

PubMed2003

Analysis of p53, K-ras, c-kit, and beta-catenin gene mutations in sinonasal NK/T cell lymphoma in northeast district of China.

Recently we reported the different frequencies of p53 and c-kit gene mutations among sinonasal NK/T cell lymphoma (NKTCL) in Korea, north China (Beijing), and Japan, suggesting some racial, environmental, or life-style differences as a possible cause of nasal tumorigenesis. In this study, gene mutations in p53, c-kit, K-ras, and beta-catenin gene were analyzed by polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) followed by direct sequencing in 20 cases of sinonasal NKTCL from northeast China (Shen Yang). Age of patients ranged from 5 to 63 (median, 40.0) years. p53 gene mutations were found in eight of 20 cases (40%), with exon 4 involvement in 10% of cases. The majority was missense mutations and G:C to A:T transition was predominant. The frequency of the c-kit and K-ras gene mutations was low (5%), while that of the beta-catenin gene was six of 20 cases (30%). From these findings, it is concluded that nasal NKTCL in northeast China shared common features with that in Korea in the younger onset of disease compared to that in Japan and lower frequency of p53 gene mutations with infrequent exon 4 involvement compared to that in Japan and north China. These differences might be caused by migration of susceptible populations or some environmental confounding factors.

Adolescent↗