Methylation-induced silencing of ASC and the effect of expressed ASC on p53-mediated chemosensitivity in colorectal cancer.

Tumor suppressor p53 is known to play a crucial role in chemosensitivity in colorectal cancer. We previously demonstrated that an apoptosis-associated speck-like protein, ASC, is a p53-target gene which regulates p53-Bax mitochondrial apoptotic pathway. ASC is also known to be a target of methylation-induced gene silencing. An inactivation of ASC might thus cause resistance to chemotherapy, and if this is the case, then the expression of ASC would restore the chemosensitivity. The aim of this study was to clarify this hypothesis. ASC was methylated in 25% of all resected specimens in patients with colorectal cancer; however, ASC methylation did not always correspond to a lack of ASC protein. When expressed in colon cancer cells, in which ASC is absent due to methylation, ASC was found to enhance the chemosensitivity in a p53-dependent manner. In p53-null cells, ASC increased the p53-mediated cell death induced by p53-expressing adenovirus infection. Our data suggest that the methylation-induced silencing of ASC might cause resistance to p53-mediated chemosensitivity in colorectal cancer. The gene introduction of ASC may thus restore such chemosensitivity, and this modality may therefore be a useful new treatment strategy for colorectal cancer.

The combined use of prostaglandin I2 analogue (OP-2507) and thromboxane A2 synthetase inhibitor (OKY-046) strongly inhibits atherosclerosis of aortic allografts in rats.

BACKGROUND: Atherosclerosis is the main lesion in allografts undergoing chronic rejection. We investigated the effect of OP-2507 (prostaglandin I2 analogue) and OKY-046 (thromboxane A2 synthetase inhibitor) on graft atherosclerosis morphologically and the production of eicosanoids in grafts in a rat aortic allograft model. METHODS: Abdominal aortic allografts of Lewis (RT-1(l)) rats were transplanted orthotopically into fully major histocompatibility complex mismatched Wistar King A/Qdj (RT-1(u)) rats that were subcutaneously administered OP-2507 (0.1 mg/kg/d) or OKY-046 (125 mg/kg/d), or both, with an osmotic pump. Four, 8, or 12 weeks later, the grafts were harvested and examined histologically, and the concentration of eicosanoids in the grafts were analyzed. RESULTS: Lewis aortic allografts in Wistar King A recipients with no treatment displayed atherosclerosis, which involved gradual intimal thickening and medial thinning with continuous inflammation in adventitia. Neither OP-2507 nor OKY-046 treatment affected the intensity of adventitial inflammation. Although inhibition of medial thinning or a decrease in medial nuclear density was not observed, OKY-046 administration alone significantly inhibited an increase in intimal thickness. OP-2507 administration alone significantly inhibited a decrease in medial nuclear density and intimal thickening. Combined treatment with OP-2507 and OKY-046 further decreased the alteration of media and intima. The ratio of thromboxane B2 and 6-keto-prostaglandin F(1alpha) in the grafts was significantly reduced by OKY-046 but not by OP-2507 alone. CONCLUSIONS: We have demonstrated that atherosclerosis in aortic allografts is inhibited by the continuous administration of either OP-2507 or OKY-046, and a combination of both agents strongly increases this inhibitory effect. Amelioration of balance in eicosanoid production in the grafts by the use of thromboxane A2 synthetase inhibitor and the simultaneous usage of stable prostaglandin I2 analogue may be a strategy for preventing atherosclerosis that results from chronic rejection.

Effect of FR167653 on pancreatic ischemia-reperfusion injury in dogs.

BACKGROUND: The role of inflammatory cytokines is still unclear in ischemia-reperfusion injury of the pancreas. We investigated the effect of FR167653 (FR), a newly developed compound that is a potent suppressor of interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha on ischemia-reperfusion injury of the isolated pancreatic tail in dogs. METHODS: The tail of the pancreas was subjected to ischemia for 90 minutes. During occlusion of the vascular inflow, the head of the pancreas was removed. A control group (n = 14) and an FR treatment group (n = 11) were evaluated for survival rate, tissue blood flow, arterial oxygen pressure (Pao(2)), serum amylase and lipase levels, glucose and insulin, liver enzymes, creatinine, IL-1beta mRNA in the peripheral blood, and histopathology. RESULTS: Six of the 14 control animals and 2 of the 11 FR-treated animals died. The FR treatment group showed lower amylase (P=.037) and lipase (P =.030) levels, lower IL-1beta mRNA expression (P =.033), and less pancreatic tissue damage (P =.041) than did the control group, but there was no remarkable change in endocrine function (P =.422). Pao(2) during the acute phase in the FR treatment group was maintained (P=.009), but pulmonary tissue was damaged. Results of biochemical and histologic examinations of the liver and kidneys were unremarkable. CONCLUSIONS: FR ameliorates ischemia-reperfusion injury of the pancreas and reduces the production of inflammatory cytokines that may contribute to secondary damage to distant organs.

Gadolinium chloride inhibits lipopolysaccharide-induced mortality and in vivo prostaglandin E2 release By splenic macrophages.

The monocytic phagocytic system, consisting primarily of tissue macrophages of the liver and spleen, produces prostaglandin E(2) (PGE(2)), a modulator of the septic response. Macrophages are known to internalize gadolinium chloride (GD), a lanthanide metal, which inhibits phagocytic function. Thus we studied the effect of in vivo GD on lipopolysacchride (LPS)-induced mortality and on LPS-stimulated PGE(2) release by cultured splenic macrophages. GD (7 mg/kg intravenously) given on the two days prior to LPS challenge (30 mg/kg intravenously) completely prevented the uniform mortality in rats. This protective effect was transient since rechallenge with LPS 10 days later was uniformly lethal. Previous work in this laboratory has established a critical role of arginine concentration on macrophage behavior in vitro. Therefore, to establish culture conditions reflective of the milieu within the portal venous system, alanine and arginine levels were measured in the portal and hepatic veins of normal and endotoxemic (LPS, 10 mg/kg intraperitoneally) rats. In contrast to alanine levels, which were not altered by endotoxemia, there was a reduction of arginine concentrations from a range of 50 to 250 micromol/L in normal rats to a range of 10 to 50 micromol/L after LPS challenge. Consequently subsequent in vitro assays of splenic macrophage secretory behavior were performed in concentrations of 1200 micromol/L arginine (in standard RPMI-1640), as well as in concentrations reflective of physiologic arginine levels (10 and 100 micromol/L in modified RPMI-1640). Rat splenic macrophages harvested after two consecutive days of either in vivo saline or GD injection (7 mg/kg intravenously) were stimulated with LPS (0.025 to 2.5 microg/ml). At 72 hours of culture, the release of PGE(2) by splenic macrophages from GD-treated rats was significantly (P <0.0001) reduced at all LPS concentrations. Increased PGE(2) production was not present when the splenic macrophages were cultured in the supraphysiologic arginine (1200 micromol/L) concentration. The results demonstrate the relevance of physiologic arginine concentrations in cell culture studies and suggest that the protection conferred by GD against septic mortality may be related to downregulation of the release of immunosuppressive PGE(2) by the monocytic phagocytic system.

Mediastinal lymph node metastasis of colon cancer: report of a case.

We herein describe a patient with mediastinal lymph node metastases which occurred after both a primary sigmoid colon cancer and metachronous ovarian metastasis had been resected. The most likely route of metastases to the mediastinum in this case is the paravertebral venous plexus probably connected to the ovarian metastasis, or so-called remetastasis. This case illustrates that the mediastinum is thus a possible metastatic site in patients with colon cancer. Surgeons should therefore pay attention to the mediastinum as well as the lung fields when checking chest X-ray films during a follow-up of patients after a resection of colon cancer.

Graft persistence effectively induces and maintains donor-specific unresponsiveness.

BACKGROUND: In the present study we attempted to evaluate the role of the graft as an alloantigen in induction and maintenance of donor-specific prolongation of allograft survival by short course(s) of FK506 treatment in rat heart transplantation. Materials and methods. In the WKA/Qdj-to-LEW combination group, FK506 (3 mg/kg/day, 7 days, s.c.) was administered from Day 0 after cardiac transplantation. A second WKA/ Qdj cardiac graft was transplanted on Day 14 into the LEW recipient after removal of the first graft on Day 3 or Day 7. In other groups an additional course of FK506 (3 mg/kg/day, 7 days, s.c.) was given from Day 35. A second WKA/Qdj cardiac graft was transplanted on Day 49 into the LEW recipient after removal of the first graft on Day 7 or Day 28. RESULTS: A short course of FK506 treatment allowed for survival prolongation of a cardiac allograft [mean survival time (MST) = 42.8 days]. Removal of the first graft on Day 7 (MST = 16.4 days) but not on Day 3 (MST = 10.2 days) caused donor-specific prolongation of the second allograft survival, which was significantly shorter than that in the recipient without the graftectomy (MST = 32.8 days). When graftectomy was performed on Day 3, there were immunohistochemically detectable levels of donor class II expressing cells in the recipient spleen on Day 7, indicating that the presence of the graft more effectively induced unresponsiveness than microchimerism alone. The additional course of FK506 treatment on Day 35 maintained graft survival (MST > 90.6 days). Removal of the first graft on Day 7 (MST = 13.5 days) or Day 28 (MST = 24.7 days) did not show significant prolongation of the second allograft survival, whereas significant survival prolongation of the second graft was observed in the recipient without the graftectomy (MST = 38.8 days). However, marked survival prolongation of the second donor-specific allograft in half of the recipients that had received the second course of FK506 treatment after graftectomy on Day 28 indicates that residual donor antigen can function as tolerizing antigen with an FK506 supplement. CONCLUSIONS: We concluded that the persistence of a graft more effectively induces and maintains donor-specific unresponsiveness than does the chimeric state of graft-derived cells alone under immunosuppression by FK506 in the rat heart transplantation model.

In vitro analysis of gadolinium chloride abrogation of the systemic tolerance induced by portal venous administration of ultraviolet B-irradiated donor cells.

BACKGROUND: Normally, a Buffalo (BUF) recipient (RT1b) rejects a heterotopically transplanted Lewis (LEW) heart (RT1l) drained into the portal vein (PV) within 14 days. However, the addition of PV administration of 25x10(6) ultraviolet B (UVB)-treated LEW spleen cells (SC) to BUF recipients 7 days before cardiac transplantation results in 70% long-term allograft survival. METHODS: In this study, we used gadolinium chloride (GdCl3) (7 mg/kg/day) to selectively block the phagocytosis of recipient hepatic Kupffer cells before PV injection of UVB-treated donor SC to examine the mechanism of tolerance induction, as measured by in vitro analysis of mixed lymphocyte culture (MLC), T cell cytotoxicity, T helper cell precursors (pTH), and cytotoxic T cell precursors (pCTL) by limiting dilution analysis. RESULTS: A BUF recipient that received untreated or gamma-irradiated LEW SC intraportally reacted to in vitro stimulation by LEW alloantigen with increased MLC proliferation, T cell cytotoxicity, pTH and pCTL frequencies, and interleukin-2 production. In contrast, SC from BUF that received UVB-treated LEW SC were hyporesponsive on MLC stimulation by donor LEW alloantigen and exhibited markedly reduced cytotoxicity, pTH and pCTL frequency, and interleukin-2 production. However, normal in vitro responsiveness resulted with stimulation by third-party Brown-Norway (RT1n) SC, thus indicating that the systemic hyporesponsiveness was specific for the UVB donor alloantigen given PV. On the other hand, GdCl3 given by intravenous injection daily for 3 days before PV alloantigen blocked the induction of in vitro hyporesponsiveness. CONCLUSION: Therefore, prevention of alloantigen sequestration by GdCl3 inhibition of hepatic Kupffer cell phagocytosis was pivotal in preventing the development of portal venous tolerance.

Primary B-cell lymphoma of the breast in patient with smoldering type adult T-cell lymphoma.

We report a patient with primary B-cell lymphoma of the breast complicated by smoldering type adult T-cell leukaemia (ATL). A 52-year-old Japanese woman complained of a rapidly enlarging lump in her right breast. She had been diagnosed to have smoldering type ATL since the age of 49. Aspiration cytology and subsequent excisional biopsy revealed B-cell type lymphoma of the breast. A gallium-scintigram showed abnormal accumulation in the bilateral breasts. Radiology was adopted because the lesion was localized only in the breasts and associated with smoldering type ATL. The lesions disappeared after the treatment.

Granulomatous mastitis diagnosed and followed up by fine-needle aspiration cytology, and successfully treated by corticosteroid therapy: report of a case.

A 36-year-old woman presented to our hospital with a rapidly growing lump in her left breast. Fine-needle aspiration (FNA) cytology of the mass revealed many epithelioid cells admixed with multinucleated Langhans-type giant cells, neutrophils, lymphocytes, and stromal cells, leading to a diagnosis of granulomatous mastitis. This report describes the clinical course of this patient in whom granulomatous mastitis was successfully treated with corticosteroid therapy. Special reference is made to the usefulness of FNA cytology in the diagnosis and follow-up of this disease.

Male breast cancer--a report of 4 cases and a review of the literature.

Male breast cancer represents only about 1% of all breast cancers. Of 451 patients with breast cancer, we have experienced four cases of male breast cancer. Characteristics of these male patients with breast cancer were an older age at diagnosis (mean: 68.5 years old), prolonged duration of symptom (ranged from 1 month to 6 years with a mean of 25.5 months), centrally located tumor, advanced staging and infiltrating ductal carcinoma in histologic type. Some reported risk factors for the development of male breast cancer, such as radiation exposure, hormonal factors and gallstone disease were present.

Pretransplant intrathymic inoculation of donor antigen combined with FK506 treatment: prolongation of survival of cardiac, but not renal, allografts in rats.

It has been shown that pretransplant intrathymic injection of donor antigen prolongs rat cardiac allograft survival. The purpose of the present study was to evaluate whether co-administration of FK506 could enhance the beneficial effect of intrathymic preimmunization; we also wished to clarify whether this combined treatment could be effective for renal allografts. Seven days prior to transplantation 5 x 10(7) donor splenocytes were injected into the thymus of LEW (RT1l) recipients of WKA (RT1u) cardiac or renal allografts. Using a miniosmotic pump, FK506 was administered for 7 days before transplantation at a dose of 3 mg/kg/day. Whereas intrathymic injection of donor splenocytes or subcutaneous FK506 alone showed limited (15.2 days) or no (7.3 days) prolongation of cardiac allograft survival, the combined treatment with these two modalities synergistically prolonged the survival of the cardiac allograft (> 82.0 days). This combined treatment, however, failed to prolong renal allograft survival (8.4 days). Although donor-specific prolongation of a second cardiac allograft was obtained in LEW rats with a well beating WKA heart, two of the three recipients ultimately rejected both first and second WKA cardiac allografts. Additionally, LEW rats with a long-surviving WKA heart rejected a WKA renal allograft in a normal fashion. These data demonstrate a synergistic effect of intrathymic injection of donor splenocytes and subcutaneous FK506 on cardiac, but not renal, allograft survival and suggest that quantitative or qualitative differences of immunogenicity of kidney may contribute to the rejection of renal allografts.