Shigeo Hara

Early Immune Reaction after Reduced-intensity Cord-blood Transplantation for Adult Patients

Background. To investigate immune reactions after reduced-intensity cord-blood transplantation (RI-CBT). Materials and Methods. We reviewed medical records of 57 adult RI-CBT recipients. Preparative regimen comprised fludarabine, total-body irradiation, and either melphalan (n=51) or busulfan (n=6). Graft-versus-host disease (GvHD) prophylaxis was cyclosporine. PostRI-CBT immune reactions were classified according to time course: pre-engraftment immune reactions (PIR), engraftment syndrome (ES), and GvHD. Results. Forty-five patients achieved engraftment at a median of day 19. PIR was characterized by high-grade fever and weight gain and developed on a median of day 9 in 35 of the 45 evaluable patients, including 3 who did not achieve engraftment. PIR subsided spontaneously in 12 patients, whereas corticosteroids were required in the other 23. ES and grade I to IV acute GvHD developed in 36 and 29 patients, respectively. GvHD could not be distinguished from preceding PIR or ES in 10 patients. Causes of the 32 nonrelapse mortalities included GvHD (n=5) and PIR (n=1). There were no significant differences in relapse and nonrelapse deaths between patients with PIR and those without it (18% vs. 5%, and 60% vs. 65%, respectively). Conclusions. Immune reactions after RI-CBT can be categorized into three distinct subtypes.

Characteristics and modifying factors of asbestos-induced oxidative DNA damage

Respiratory exposure to asbestos has been linked with mesothelioma in humans. However, its carcinogenic mechanism is still unclear. Here we studied the ability of chrysotile, crocidolite and amosite fibers to induce oxidative DNA damage and the modifying factors using four distinct approaches. Electron spin resonance analyses revealed that crocidolite and amosite containing high amounts of iron, but not chrysotile, catalyzed hydroxyl radical generation in the presence of H2O2, which was enhanced by an iron chelator, nitrilotriacetic acid, and suppressed by desferal. Natural iron chelators, such as citrate, adenosine 5′‐triphosphate and guanosine 5′‐triphosphate, did not inhibit this reaction. Second, we used time‐lapse video microscopy to evaluate how cells cope with asbestos fibers. RAW264.7 cells, MeT‐5 A and HeLa cells engulfed asbestos fibers, which reached not only cytoplasm but also the nucleus. Third, we utilized supercoiled plasmid DNA to evaluate the ability of each asbestos to induce DNA double strand breaks (DSB). Crocidolite and amosite, but not chrysotile, induced DNA DSB in the presence of iron chelators. We cloned the fragments to identify break sites. DSB occurred preferentially within repeat sequences and between two G:C sequences. Finally, i.p. administration of each asbestos to rats induced not only formation of nuclear 8‐hydroxy‐2′‐deoxyguanosine in the mesothelia, spleen, liver and kidney but also significant iron deposits in the spleen. Together with the established carcinogenicity of i.p. chrysotile, our data suggest that asbestos‐associated catalytic iron, whether constitutional or induced by other mechanisms, plays an important role in asbestos‐induced carcinogenesis and that chemoprevention may be possible through targeting the catalytic iron. (Cancer Sci 2008; 99: 2142–2151)

Fluorescence (Förster) resonance energy transfer imaging of oncogene activity in living cells

A hallmark of cancer cells is their uncontrolled activation of growth signal transduction cascades comprised of oncogene products. Overexpression and activating mutations of the growth factor receptors Ras and Raf are frequently observed in human cancer cells. Several research groups, including our own, have been developing probes based on the principle of fluorescence (Förster) resonance energy transfer (FRET) to visualize how signaling molecules, including oncogene products, are regulated in normal and cancerous cells in the living state. In this review, we will briefly introduce the principle of FRET‐based probes, present an overview of the probes reported to date, and discuss the perspectives of these probes and fluorescent imaging systems in cancer biology. (Cancer Sci 2006; 97: 8–15)

Use of hydroxy-methyl-glutaryl coenzyme A reductase inhibitors is associated with risk of lymphoid malignancies

It has been speculated that the use of hydroxy‐methyl‐glutaryl coenzyme A reductase inhibitors (statins) is associated with the risk of malignant diseases. Considering their immunosuppressive activities, malignant diseases that are associated with an immunosuppressive status seem feasible to examine the association. We therefore examined the association between statin use and development of lymphoid malignancies in a case‐control study. Cases were 221 consecutive incident cases with histopathologically proven lymphoid malignancies (lymphoma and myeloma), hospitalized in the Department of Hematology of Toranomon Hospital (Tokyo, Japan) between 1995 and 2001. Two independent control groups, comprising 442 and 437 inpatients without malignancies from the Departments of Orthopedics and Otorhinolaryngology of the same hospital, were selected to test for consistency of association. Controls were matched individually with cases for age, sex and year of admission. Subject information, including statin use, was abstracted from medical records at the time of hospitalization. Strength of association was evaluated as an adjusted odds ratios (aOR) using a conditional logistic regression model. A higher frequency of statin use was found among patients with lymphoid malignancies in comparison with both orthopedic (aOR 2.11, 95% CI 1.20–3.69, P = 0.009) and otorhinolaryngology patients (aOR 2.59, 95% CI 1.45–4.65, P = 0.001), the significance being maintained when the two control groups were combined (aOR 2.24, 95% CI 1.37–3.66, P = 0.001). In conclusion, we observed an elevated risk of lymphoid malignancy with statin use among Japanese patients. Further evaluations in different populations are required to draw conclusions as to the carcinogenicity of lymphoid malignancies with statin use. (Cancer Sci 2006; 97: 133 –138)

The DHR1 domain of DOCK180 binds to SNX5 and regulates cation-independent mannose 6-phosphate receptor transport.

DOCK180 is the archetype of the DOCK180-family guanine nucleotide exchange factor for small GTPases Rac1 and Cdc42. DOCK180-family proteins share two conserved domains, called DOCK homology region (DHR)-1 and -2. Although the function of DHR2 is to activate Rac1, DHR1 is required for binding to phosphoinositides. To better understand the function of DHR1, we searched for its binding partners by direct nanoflow liquid chromatography/tandem mass spectrometry, and we identified sorting nexins (SNX) 1, 2, 5, and 6, which make up a multimeric protein complex mediating endosome-to-trans-Golgi-network (TGN) retrograde transport of the cation-independent mannose 6-phosphate receptor (CI-MPR). Among these SNX proteins, SNX5 was coimmunoprecipitated with DOCK180 most efficiently. In agreement with this observation, DOCK180 colocalized with SNX5 at endosomes. The RNA interference-mediated knockdowns of SNX5 and DOCK180, but not Rac1, resulted in the redistribution of CI-MPR from TGN to endosomes. Furthermore, expression of the DOCK180 DHR1 domain was sufficient to restore the perturbed CI-MPR distribution in DOCK180 knockdown cells. These data suggest that DOCK180 regulates CI-MPR trafficking via SNX5 and that this function is independent of its guanine nucleotide exchange factor activity toward Rac1.

Postmortem examination of the kidney in allogeneic hematopoietic stem cell transplantation recipients: possible involvement of graft-versus-host disease

To investigate the association between graft-versus-host disease (GVHD) and renal injury after allogeneic stem cell transplantation (allo-SCT), we compared autopsy findings of 26 consecutive allo-SCT recipients with two control groups: patients with hematologic malignancies who received cytotoxic chemotherapy alone (Control 1, n = 21) and those with non-hematologic diseases (Control 2, n = 12). We evaluated the following renal pathology; renal tubulitis, allograft glomerulitis, intimal arteritis, allograft nephropathy, and peritubular capillaritis. These changes were found in 11 allo-SCT recipients and 10 patients in Control 1, but none in Control 2. While overall frequency of renal impairments was similar between allo-SCT recipients and Control 1 (3/26 vs. 1/21), allo-SCT recipients were more likely to have renal tubulitis and peritubular capillaritis compared to Control 1 (5/26 vs. 1/21), but less likely to present with glomerulitis (1/26 vs. 6/21). Grade III–IV acute or extensive-type chronic GVHD were seen in all of the three patients with renal tubulitis and four of the five patients with peritubular capillaritis. Allo-SCT recipients with severe GVHD tended to have tubulitis and peritubular capillaritis. These findings have implications of some renal impairment attributable to GVHD.

Intestinal thrombotic microangiopathy following reduced-intensity umbilical cord blood transplantation

Summary:Thrombotic microangiopathy (TMA) is a significant complication after hematopoietic stem-cell transplantation (HSCT); however, there is little information on it following reduced-intensity cord blood transplantation (RI-CBT). We reviewed the medical records of 123 adult patients who received RI-CBT at Toranomon Hospital between January 2002 and August 2004. TMA was diagnosed in seven patients based on intestinal biopsy (n=6) or autopsy results (n=1). While these patients showed some clinical symptoms such as diarrhea and/or abdominal pain, mental status alterations or neurological disorders were not observed in any of them. Laboratory results were mostly normal at the onset of TMA; >2% fragmented erythrocytes (n=1), <10 mg/dl haptoglobin (n=1), and >200 IU/dl lactic dehydrogenase (LD) (n=4). On endoscopic examination, TMA lesions, consisting of ulcers, erosions, and diffuse exfoliation, were distributed spottily from terminal ileum to rectum. Intestinal graft-versus-host disease (GVHD) and cytomegalovirus (CMV) colitis were confirmed in five and four patients, respectively. With therapeutic measures including supportive care (n=4), fresh frozen plasma (n=1), and a reduction of immunosuppressive agents (n=1), TMA improved in four patients. The present study demonstrates that intestinal TMA is a significant complication after RI-CBT. Since conventional diagnostic criteria can overlook TMA, its diagnosis requires careful examination of the gastrointestinal tract using endoscopy with biopsy.

Ankyrin repeat domain 28 (ANKRD28), a novel binding partner of DOCK180, promotes cell migration by regulating focal adhesion formation.

DOCK180 is a guanine exchange factor of Rac1 originally identified as a protein bound to an SH3 domain of the Crk adaptor protein. DOCK180 induces tyrosine phosphorylation of p130(Cas), and recruits the Crk-p130(Cas) complex to focal adhesions. To understand the role of DOCK180 in cell adhesion and migration, we searched for DOCK180-binding proteins with a nano-LC/MS/MS system, and identified ANKRD28, a protein that contains twenty-six ankyrin domain repeats. Knockdown of ANKRD28 by RNA interference reduced the velocity of migration of HeLa cells, suggesting that this protein plays a physiologic role in the DOCK180-Rac1 signaling pathway. Furthermore, knockdown of ANKRD28 was found to alter the distribution of focal adhesion proteins such as Crk, paxillin, and p130(Cas). On the other hand, expression of ANKRD28, p130(Cas), Crk, and DOCK180 induced hyper-phosphorylation of p130(Cas), and impaired detachment of the cell membrane during migration. Consequently, cells expressing ANKRD28 exhibited multiple long cellular processes. ANKRD28 associated with DOCK180 in an SH3-dependent manner and competed with ELMO, another protein bound to the SH3 domain of DOCK180. In striking contrast to ANKRD28, overexpression of ELMO induced extensive lamellipodial protrusion around the entire circumference. These data suggest that ANKRD28 specifies the localization and the activity of the DOCK180-Rac1 pathway.

Outcome and treatment of bucillamine-induced nephropathy

Background: Bucillamine (BCL), a treatment for rheumatoid arthritis, occasionally causes proteinuria. Renal specimens are reported to show segmental granular deposition of immunoglobulin G, associated with membranous nephropathy. Long-term course and optimal treatment have remained unknown, and were investigated here. Methods: We examined clinical records of 400 patients treated with BCL for rheumatoid arthritis, at our hospital from 1998 to 2003, finding 17 with proteinuria and biopsy-proven BCL-induced nephropathy. Results: In all 17 patients, proteinuria resolved without loss of renal function between 3 and 85 months after discontinuing BCL (14.1 ± 3.4). The only factor influencing time to remission was pathologic stage of membranous nephropathy (stage I vs. stage II or III: 11.5 ± 4.8 vs. 21.6 ± 3.3 months; p = 0.02). Maximal proteinuria, total amount of BCL, BCL exposure time, and use of prednisolone or other immunosuppressant agents did not significantly influence time until remission. Conclusion: The most important therapeutic step in treating BCL-induced nephropathy is to discontinueBCL. Prednisolone or other immunosuppressant agents might not be effective.

Long‐term course of post‐transplant mesangial IgA deposition: clinicopathologic study of nine cases

Abstract:  We conducted the present study to elucidate the fate of post‐transplant mesangial IgA deposit under the long‐term observation. Out of a total of 45 cases with post‐transplant mesangial IgA deposition, nine cases with more than 4 yr of follow‐up term were enrolled in this study, and clinicopathologic characteristics were described. The study included three men and six women with a mean age of 34.2 yr. The average observation time from the detection of mesangial IgA deposition was 6.1 yr. Three cases were categorized as recurrent IgA nephropathy, while six cases were classified into latent mesangial IgA deposition. One case with hypertension developed end‐stage renal disease. The significant improvement in microscopic hematuria was observed in one recurrent IgA nephropathy case. Microscopic findings included mild mesangial stalk thickening in all but one case. IgA deposition demonstrated a significant decrease in three latent mesangial IgA deposition cases. No apparent reduction in dense deposit quantity was observed on electron microscopy. There was no association between clinicopathologic findings and the regimen of anti‐immunosuppressive agents. This study showed the improvement of the disease activity did occur in both recurrent IgA nephropathy and latent mesangial IgA deposition. Further investigation of latent mesangial IgA deposition may present the important clue to the pathogenesis of IgA nephropathy.