Autoantibody-mediated regulation of B cell responses by functional anti-CD22 autoantibodies in patients with systemic sclerosis.

Studies have demonstrated that B cells play important roles in systemic sclerosis (SSc), especially through the CD19/CD22 autoimmune loop. CD22 is a B cell-specific inhibitory receptor that dampens B cell antigen receptor (BCR) signalling via tyrosine phosphorylation-dependent mechanism. In this study, we examined the presence and functional property of circulating autoantibodies reacting with CD22 in systemic sclerosis. Serum samples from 10 tight skin (TSK/+) mice and 50 SSc patients were assessed for anti-CD22 autoantibodies by enzyme-linked immunosorbent assays using recombinant mouse or human CD22. The association between anti-CD22 antibodies and clinical features was also investigated in SSc patients. Furthermore, the influence of SSc serum including anti-CD22 autoantibodies for CD22 tyrosine phosphorylation was examined by Western blotting using phosphotyrosine-specific antibodies reacting with four major tyrosine motifs of CD22 cytoplasmic domain. Anti-CD22 autoantibodies were positive in 80% of TSK/+ mice and in 22% of SSc patients. Patients positive for anti-CD22 antibodies showed significantly higher modified Rodnan skin thickness score compared with patients negative for anti-CD22 antibodies. Furthermore, anti-CD22 antibodies from patients' sera were capable of reducing phosphorylation of all four CD22 tyrosine motifs, while sera negative for anti-CD22 antibodies did not affect CD22 phosphorylation. Thus, a subset of SSc patients possessed autoantibodies reacting with a major inhibitory B cell response regulator, CD22. Because these antibodies can interfere CD22-mediated suppression onto B cell activation in vitro, SSc B cells produce functional autoantibodies that can enhance their own activation. This unique regulation may contribute to the autoimmune aspect of SSc.

Autoantibody against activating transcription factor-2 in patients with systemic sclerosis.

OBJECTIVES: To determine the prevalence and clinical correlation of autoantibody to activating transcription factor (ATF)-2, a transcription factor of ATF/CREB family, in patients with systemic sclerosis (SSc). METHODS: Anti-ATF-2 Ab was examined by ELISA and immunoblotting using human recombinant ATF-2. ATF-2 activity to bind target DNA was evaluated by ELISA using a plate coated with oligonucleotide containing the consensus binding site for ATF-2. RESULTS: IgG anti-ATF-2 Ab levels in SSc patients (n=69) were significantly higher than those in normal controls (n=26). SSc patients positive for IgG anti-ATF-2 Ab had significantly longer disease duration, more frequent presence of decreased %VC and %DLco, and elevated levels of serum IgG, serum IgA, and erythrocyte sedimentation rates than those negative. More-over, IgG anti-ATF-2 Ab levels correlated inversely with %VC or %DLco. The presence of anti-ATF-2 Ab in SSc patients was confirmed by immunoblotting analysis. IgG isolated from serum samples of SSc patients positive for IgG anti-ATF-2 Ab by ELISA slightly but significantly inhibited ATF-2 activity compared with normal controls. CONCLUSIONS: These results suggest that anti-ATF-2 Ab is a new autoantibody in SSc and that it serves as a novel serological marker for inflammation and lung involvement in SSc.

Psychological and behavioral mechanisms influencing the use of complementary and alternative medicine (CAM) in cancer patients.

BACKGROUND: This study explored the psychological and behavioral mechanisms of complementary and alternative medicine (CAM) use in Japanese cancer patients using two applied behavioral models, the transtheoretical model (TTM), and theory of planned behavior (TPB). PATIENTS AND METHODS: Questionnaires were distributed to 1100 patients at three cancer treatment facilities in Japan and data on 521 cancer patients were used in the final analysis. The questionnaire included items based on TTM and TPB variables, as well as three psychological batteries. RESULTS: According to the TTM, 88 patients (17%) were in precontemplation, 226 (43%) in contemplation, 33 (6%) in preparation, 71 (14%) in action, and 103 (20%) in maintenance. The model derived from structural equation modeling revealed that the stage of CAM use was significantly affected by the pros, cons, expectation from family, norms of medical staff, use of chemotherapy, period from diagnosis, and place of treatment. The primary factor for the stage of CAM use was the expectation from family. CONCLUSIONS: The findings revealed the existence of a number of psychologically induced potential CAM users, and psychological variables including positive attitude for CAM use and perceived family expectation greatly influence CAM use in cancer patients.

Involvement of gaseous low molecular monoxides in the cutaneous reverse passive Arthus reaction: cytoprotective action of carbon monoxide.

The deposition of immune complexes (IC) induces an acute inflammatory response with tissue injury, for which the involvement of nitric oxide (NO) and carbon monoxide (CO) has been suggested. NO is induced by NO synthase (NOS) and CO is generated by haeme oxygenase (HO). Among HO isoenzymes, HO-1 is an induced type. To assess the role of NO and CO in the pathogenic process, the cutaneous reverse passive Arthus reaction was examined using NOS inhibitor, HO-1 stimulator and HO-1 inhibitor. To evaluate the reaction we considered oedema, tumour necrosis factor-alpha, interleukin-6, and neutrophil number. The values of these four parameters were significantly reduced in mice treated with HO-1 stimulator as compared with the positive control mice. Quite the reverse was observed in mice treated with HO-1 inhibitor. These results suggest that the HO-1/CO signalling pathway is a therapeutic target for human IC-mediated disease.

Blockade of CD40/CD40 ligand interactions attenuates skin fibrosis and autoimmunity in the tight-skin mouse.

OBJECTIVE: To assess the association of CD40/CD40 ligand (CD40L) interactions with the development of skin fibrosis and autoimmunity in tight-skin (TSK/+) mouse, which is a mouse model for human systemic sclerosis. METHODS: Newly born TSK/+ mice were treated with murine anti-CD40L monoclonal antibody (100 microg intraperitoneally weekly). Hypodermal thickness of 8-week-old female mice (defined as the thickness of a subcutaneous loose connective tissue layer beneath the panniculus carnosus) was measured under a light microscope. All skin sections were taken from the para-midline, upper back region. Serum anti-topoisomerase I autoantibody levels, serum immunoglobulin levels and plasma soluble CD40L levels were determined by enzyme-linked immunosorbent assay. For analysis of lymphocyte surface molecules, single cell suspensions of lymphocytes were stained by monoclonal antibodies. Proliferation of TSK/+ B cells and fibroblasts to anti-CD40 antibodies was assessed by the uptake of [3H]-labelled thymidine and bromodeoxyuridine, respectively. RESULTS: The blockade of CD40/CD40L interactions by anti-CD40L monoclonal antibody significantly reduced cutaneous fibrosis (65%) and anti-topoisomerase I autoantibody in TSK/+ mice. Anti-CD40L monoclonal antibody also normalised B lymphocyte abnormal activation in TSK/+ mice, demonstrated by hyper-gamma-globulinaemia. Furthermore, augmented CD40/CD40L interactions in TSK/+ mice were suggested by upregulated expression of CD40L on CD4(+) T cells, elevated plasma soluble CD40L levels. The hyperresponsiveness to CD40 stimulation was also observed in TSK/+ B cells and fibroblasts. CONCLUSIONS: Cutaneous fibrosis and autoimmunity in TSK/+ mice are closely correlated with CD40/CD40L interactions.

Autoantibody against a protease domain of caspase-8 in patients with systemic sclerosis.

BACKGROUND: Systemic sclerosis (SSc) is characterized by autoantibodies against various cellular components. OBJECTIVE: To determine the presence or levels of antibodies (Abs) against a protease domain (PD) of caspase-8 and their clinical relevance in SSc. METHODS: Anti-caspase-8 PD Ab was examined by enzyme-linked immunosorbent assay and immunoblotting using human recombinant caspase-8 PD. Caspase-8 activity was evaluated by spectrophotometric detection of cleavage from p-nitroanilide-labeled IETD, a substrate of caspase-8. RESULTS: IgG anti-caspase-8 PD Ab levels in patients with SSc, systemic lupus erythematosus, or dermatomyositis were higher than in normal controls (CTL). Furthermore, anit-caspase-8 PD Ab levels in limited cutaneous SSc (ISSc) patients were elevated compared to diffuse cutameous SSc (dSSc) patients. To investigate the clinical correlation, laboratory findings were compared between SSc patients with high levels (>the mean+2SD of CTL) of anti-caspase-8 PD Ab and those with low levels. SSc patients with high level exhibited lower frequency of male and decreased C-reactive protein levels relative to those with low levels. Immunoblotting showed the anit-caspase-8 PD Ab was present in all SSc patients examined, while it was also detected in 75% of CTL. Caspase-8 activity was inhibited by IgG isolated from sera of SSc patients and CTL, although inhibitory effect was greater in SSc patients than CTL. CONCLUSION: These results suggest that immune response to caspase-8 occurs in healthy individuals, although it is greater in patients with systemic autoimmune diseases including SSc. Furthermore, high level of anti-caspase-8 PD Ab may be a serological indicator for a milder SSc subset.

Safety of Elderly Living Kidney Donors: 2 Cases of Donors Older Than 80 Years: A Case Report.

Much controversy exists over the performance of elderly living donor kidney transplantation. We report the safety of 2 cases of elderly living kidney donations in our hospital. CASE 1: An 82-year-old man was a living kidney donor for his 56-year-old son. The donor suffered from hypertension, but has successfully managed his blood pressure with only one medication. His serum creatinine was 0.7 mg/dL and inulin clearance was 122.5 mL/min, which met the usual criteria for living kidney donors. This was his son's secondary kidney transplantation, and no other donors existed. CASE 2: An 80-year-old woman was a living kidney donor for her 45-year-old son. Her serum creatinine was 0.61 mg/dL and inulin clearance was 71.7 mL/min, which met the marginal kidney donor criteria. In both cases, we determined that the donor kidney function was acceptable. Though we explained the risks of the transplantation thoroughly, the patients' strong will to offer a kidney to their family member did not change. We decided to carry out the transplantation. At the time of publication, nearly 2 years have passed since the transplantation, but both donors and recipients are doing well. In the future, it seems more likely that the number of elderly living donor kidney transplantation will rise. On one hand, there is no absolute contraindication for elderly donors, while on the other hand, the criteria for a living kidney donor must be strictly examined. Furthermore, careful observation of both donors and recipients after transplantation is required.

Effect of Systematic Conversion to Generic Mycophenolate Mofetil (MMF) in Kidney Transplantation: A Single-Center Clinical Experience from Japan.

INTRODUCTION: Recently, more and more generic drugs have been used for immunosuppressive drugs in the field of organ transplantation. Some reports have indicated that blood concentration of most generic drugs is difficult to maintain stability, and it may cause the difference in graft survival of transplanted organs between original drugs and generic drugs. In this article, we report the cases could not maintain blood concentration of generic drugs of mycophenolate mofetil (MMF). RESULTS: In 4 cases out of 5 cases that we had to change original MMF to generic MMF, there were cases that blood concentration level was not stabilized. There were possibility that the lowered blood concentration level of MMF caused a rejection, in two cases. Mean MMF trough level was decreased from 3.6 ± 1.9 µg/mL to 0.6 ± 0.4 µg/mL. Due to the early detection, it did not become severe or failure of graft function, however, we cannot deny the possibilities that side effects were increased and rejection rose. In these cases, we discontinued to use the generic drugs thereafter due to unstable plasma concentration of MMF. DISCUSSION: Some reports have indicated that failure to maintain plasma concentration of MMF leads to rejection. Therefore, maintenance of effective plasma concentration and prevention of rejection are essential to long-term graft survival in kidney transplant. CONCLUSION: Generic drug formulations may exhibit differences in effects and absorption compared to the brand-name drug. If the generic drug should be used, patients should be closely monitored.

Increased serum levels of nitrotyrosine, a marker for peroxynitrite production, in systemic sclerosis.

OBJECTIVE: To determine serum levels of nitrotyrosine (NT), an end product of peroxynitrite (ONOO-), and its clinical association in patients with systemic sclerosis (SSc). METHODS: Serum NT levels from 25 patients with limited cutaneous SSc (lSSc) and 34 patients with diffuse cutaneous SSc (dSSc) were examined by enzyme-linked immunosorbent assay. RESULTS: Serum NT levels were elevated in SSc patients compared with normal controls (n = 27), the levels being similar between lSSc and dSSc patients (P < 0.001). SSc patients with elevated NT had higher serum levels of anti- agalactosyl IgG Ab, IgG and IgA than those with normal NT levels (P < 0.05). NT levels correlated inversely with the percentage diffusion capacity for carbon monoxide (DLco) (P < 0.02, r = -0.414, n = 47). CONCLUSION: These results suggest that ONOO- may play an important role in the clinical manifestations of SSc, especially vascular damage to the lungs, and that ONOO- may be related to immunological abnormalities in SSc.

Plutonium and 137Cs in surface water of the South Pacific Ocean.

The present plutonium and 137Cs concentrations in South Pacific Ocean surface waters were determined. The water samples were collected in the South Pacific mid-latitude region (32.5 degrees S) during the BEAGLE expedition conducted in 2003-04 by JAMSTEC. 239,240Pu concentrations in surface seawater of the South Pacific were in the range of 0.5 to 4.1 mBq m(-3), whereas 137Cs concentrations ranged from 0.07 to 1.7 Bq m(-3). The observed 239,240Pu and 137Cs concentrations in the South Pacific were almost of the same level as those in the North Pacific subtropical gyre. The surface 239,240Pu in the South Pacific subtropical gyre showed larger spatial variations than 137Cs, as it may be affected by physical and biogeochemical processes. The 239,240Pu/137Cs activity ratios, which reflect biogeochemical processes in seawater, were generally smaller than that observed in global fallout, except for the most eastern station. The 239,240Pu/137Cs ratios in the South Pacific tend to be higher than that in the North Pacific. The relationships between anthropogenic radionuclides and oceanographic parameters such as salinity and nutrients were examined. The 137Cs concentrations in the western South Pacific (the Tasman Sea) and the eastern South Pacific were negatively correlated with the phosphate concentration, whereas there is no correlation between the 137Cs and nutrients concentrations in the South Pacific subtropical gyre. The mutual relationships between anthropogenic radionuclides and oceanographic parameters are important for better understanding of transport processes of anthropogenic radionuclides and their fate in the South Pacific.

Atomic bomb induced 152Eu: reconciliation of discrepancy between measurements and calculation.

In order to resolve the discrepancy between the measured and calculated 152Eu activity induced by the atomic bomb at Hiroshima, extremely low background gamma-ray spectrometry was performed for 17 granite samples collected from 134 m to more than 3 km from the hypocenter. Measurements agreed well with theoretical calculations based on DS02 up to 1.4 km from hypocenter.

Measurements of short-lived cosmic-ray-produced radionuclides in rainwater.

Cosmic-ray-produced (CP) nuclides with half-lives shorter than 21h were measured in rainwater by ultra-low-background gamma spectrometry at Ogoya Underground Laboratory. As levels of CP nuclides are extremely low and their half-lives are very short, quick sampling methods for a large volume of rainwater and rapid chemical separations by ion exchange method were developed. The nuclides measured were short-lived (24)Na, (28)Mg, (38)S, (38)Cl, (39)Cl, as well as nuclides with longer half-lives (7)Be and (22)Na. The number of atoms of CP nuclides in rainwater were evaluated to range from 30 to 1500L(-1) for (24)Na (n=16, mean; 520 [6.7mBqL(-1)]), 80 to 600L(-1) for (28)Mg (n=13, mean; 260 [2.4mBqL(-1)]), 400 to 1900L(-1) for (39)Cl (n=6, mean; 1200 [250mBqL(-1)]), 1x10(6) to 4x10(7)L(-1) for (7)Be (n=16, mean; 7x10(6) [1.05BqL(-1)]) and 2x10(3) to 1x10(5)L(-1) for (22)Na (n=9, mean; 2x10(4) [0.2mBqL(-1)]).

MUC1-C activates BMI1 in human cancer cells.

B-cell-specific Moloney murine leukemia virus integration site 1 (BMI1) is a component of the polycomb repressive complex 1 (PRC1) complex that is overexpressed in breast and other cancers, and promotes self-renewal of cancer stem-like cells. The oncogenic mucin 1 (MUC1) C-terminal (MUC1-C) subunit is similarly overexpressed in human carcinoma cells and has been linked to their self-renewal. There is no known relationship between MUC1-C and BMI1 in cancer. The present studies demonstrate that MUC1-C drives BMI1 transcription by a MYC-dependent mechanism in breast and other cancer cells. In addition, we show that MUC1-C blocks miR-200c-mediated downregulation of BMI1 expression. The functional significance of this MUC1-C→︀BMI1 pathway is supported by the demonstration that targeting MUC1-C suppresses BMI1-induced ubiquitylation of H2A and thereby derepresses homeobox HOXC5 and HOXC13 gene expression. Notably, our results further show that MUC1-C binds directly to BMI1 and promotes occupancy of BMI1 on the CDKN2A promoter. In concert with BMI1-induced repression of the p16INK4a tumor suppressor, we found that targeting MUC1-C is associated with induction of p16INK4a expression. In support of these results, analysis of three gene expresssion data sets demonstrated highly significant correlations between MUC1-C and BMI1 in breast cancers. These findings uncover a previously unrecognized role for MUC1-C in driving BMI1 expression and in directly interacting with this stem cell factor, linking MUC1-C with function of the PRC1 in epigenetic gene silencing.

Seasonal variations in 228Ra/226Ra ratio within coastal waters of the Sea of Japan: implications for water circulation patterns in coastal areas.

In this study, low-background gamma-spectrometry was used to determine the (228)Ra/(226)Ra ratio of 131 coastal water samples from various environments around Honshu Island, Japan (mainly around Noto Peninsula) at 1-3 month intervals from April 2003 until September 2005. Spatial variation in (228)Ra/(226)Ra ratios was also assessed by analyzing 34 coastal water samples from five areas within the Sea of Japan during May and June 2004. The (228)Ra/(226)Ra ratio of coastal water from all sites around Noto Peninsula shows seasonal variation, with minimum values during summer ((228)Ra/(226)Ra=0.7) and maximum values during autumn-winter ((228)Ra/(226)Ra=1.7-2). This seasonal variation is similar to that recorded for coastal water between Tsushima Strait and Noto Peninsula. The measured lateral variation in (228)Ra/(226)Ra ratios within coastal water between Tsushima Strait and Noto Peninsula is only minor (0.5-0.7; May-June 2004). Coastal waters from two other sites (Pacific shore and Tsugaru Strait, north Honshu) show no clear seasonal variation in (228)Ra/(226)Ra ratio. These measured variations in (228)Ra/(226)Ra ratio, especially the temporal variations, have important implications for seasonal changes in patterns of coastal water circulation within the Sea of Japan.

Seasonal variation of 228Ra/226Ra ratio in seaweed: implications for water circulation patterns in coastal areas of the Noto Peninsula, Japan.

To examine water circulation patterns of coastal water, 72 seaweed (Sargasso) samples and 27 coastal water samples were collected from coastal areas of the Noto Peninsula, Japan, during the period from December 1998 to June 2002. The (228)Ra and (226)Ra activities of those samples were measured by low-background gamma-ray spectrometry. There was a wide range of activities of (228)Ra (0.5-2Bq/kg-fresh) and (226)Ra (0.5-1.2Bq/kg-fresh) in the Sargasso samples. The (228)Ra/(226)Ra activity ratio of Sargasso samples exhibited seasonal variation with minimum values in June ((228)Ra/(226)Ra= approximately 1) and maximum values in December (1.5-2.5), which was mainly governed by changes in (228)Ra activity. It is also notable that the seasonal variation of the (228)Ra/(226)Ra ratio of Sargasso is in approximate agreement with that of the ambient coastal water. Sargasso samples appear to have retained the (228)Ra/(226)Ra ratio of the ambient coastal waters, and the temporal variations in that ratio provide insight into seasonal changes in water circulation in the Noto Peninsula coastal area.

Hepatocellular carcinoma with sarcomatous change arising in primary biliary cirrhosis.

We report an autopsy case of hepatocellular carcinoma (HCC) with sarcomatous change arising in the context of primary biliary cirrhosis (PBC) in a 79-year-old man. Primary biliary cirrhosis was diagnosed (stage I according to Scheuer's classification) by findings on blood biochemical analysis, laparoscopy, and liver biopsy at age 69 years. Five years later, (at age 74 years), a mass lesion was detected in the S6 region of the liver by abdominal ultrasonography, and target biopsy revealed well differentiated HCC. Blood biochemistry, ultrasonography, and computed tomography findings showed that the PBC had progressed to stage IV (cirrhotic stage). Percutaneous ethanol injection therapy (PEIT) was administered to the HCC several times over a 5-year period; however, the patient died of liver failure in February, 1994 (at age 79 years). Viral markers for hepatitis B and C were negative during the course, and hepatitis C virus RNA was not detected by polymerase chain reaction. Autopsy findings showed liver cirrhosis and diffuse involvement of spindle-shaped sarcomatoid cells in the liver, particularly in the S6 region, associated with several nodules of trabecular HCC cells. A zone of transition between the sarcomatoid cells and the trabecular hepatocellular carcinoma cells was observed. The sarcomatoid cells were diffusely disseminated in the peritoneal cavity and had metastasized to multiple organs. Immunohistochemically, the cells were positive for fibrinogen, as were the coexisting trabecular hepatocellular carcinoma cells. The HCC had been treated several times with PEIT. Of interest, PEIT may be an important factor in this type of tumor progression.

Radiochemical approach to the JCO criticality accident in Tokai-mura, 1999--an overview of the radiochemistry group.

A few days after the JCO criticality accident in Tokai-mura, a collaborating scientific investigation group was organized to evaluate the environmental impact of the accident. The group consisted of two groups: an environmental research group (radiochemistry group) and a biological research group. This paper overviews the scientific activity of the former group based on 6 sampling campaigns conducted at the JCO campus, Tokai-mura and Naka-machi. Some of the topical results and our remaining tasks concerning the JCO accident are discussed.

A review of forty-five years study of Hiroshima and Nagasaki atomic bomb survivors. Residual radioactivity in neutron-exposed objects and residual alpha radioactivity in black rain areas.

The residual Eu-142 radioactivity due to the atomic bomb explosion in 1945 was first found in 1976 by in-situ high resolution gamma-ray spectrometry at Hiroshima. Since then, various studies on this nuclide have continued not only in Hiroshima but also in Nagasaki and they have contributed to the reevaluation of the neutron dose due to the A-bombing. By radiochemical separation methods and alpha-ray spectrometry, rather high levels of plutonium were found in the surface soil and in the bottom sediment of water reservoir which were collected at "Black rain area" in Nagasaki. The U-234/U-238 activity ratios for the uranium leached with 0.1 HNO3 from the surface of soil samples were found to be relatively higher for the samples which were collected at "Black rain area" in Hiroshima.

Activation of soil and chemical reagents exposed to the neutrons released by the JCO criticality accident in Tokai-mura.

Specific activities (Bq/g-element) of residual neutron-induced radionuclides by the JCO criticality accident were measured for soil, concrete block and chemical reagent samples collected in the JCO campus. Induced radionuclides such as 24Na, 46Sc, 54Mn, 59Fe, 60Co, 65Zn, 82Br, 122Sb, 134Cs and 140La were detected in the samples, depending on the ground distance from the accident point and the sampling date. Apparent thermal, epi-thermal and fast neutron fluences, which reached the sample at each point, were roughly estimated from the specific activities and cross sections of the target nuclides taken from a literature. The present data are believed to be important as validation data for a three-dimensional neutron transport model calculation.

Two types of sporadic multiple colorectal cancers with and without HNPCC-like genetic instability.

BACKGROUND/AIMS: Sporadic multiple colorectal cancers (MCCs) potentially have similar genetic alterations to hereditary nonpolyposis colorectal cancers (HNPCCs), but genetically unstable MCCs other than HNPCCs are not well characterized. We report the frequency of HNPCC-like sporadic multiple colon cancers and their characterization as for HNPCC-related gene mutations. METHODOLOGY: Microsatellite instability (MSI) at 12 microsatellite loci was examined by a polymerase chain reaction in 19 cases each of MCC and single colorectal cancer (SCC). The target sequences of MSI, transforming growth factor beta type II receptor (TGF beta RII) gene, and the HNPCC genes, hMSH2 and hMLH1, were amplified and analyzed for mutations by sequencing. RESULTS: In 5 of 19 cases with MCC, MSI was observed at more than 4 microsatellite loci, and the other cases including all SCCs showed no MSI or MSI(+) at a single locus. In 4 of the 5 severe MSI(+) cases, a 10-bp adenine tract at codons 125-128 of the TGF beta RII gene was mutated. In terms of the hMSH2 and hMLH1 genes, only silent mutations and non-critical amino acid substitutions were found. CONCLUSIONS: We found severe MSI in 26% of sporadic multiple colorectal cancers. Mutations of the TGF beta RII gene are closely associated with severe MSI(+) MCCs as observed in HNPCC, suggesting that these MCCs develop by the similar carcinogenic process to HNPCC.