Toshiro Nishida

Proteomics-based identification of α-enolase as a tumor antigen in non-small lung cancer

Autoantibodies against tumor antigens represent one type of biomarker that may be assayed in serum for detection of cancer and monitoring of disease progression. In the present study, we used a proteomics‐based approach to identify novel tumor antigens in non‐small cell lung cancer (NSCLC). By combining two‐dimensional electrophoresis, western blotting, mass spectrometry and enzyme‐linked immunosorbent assay technology, we detected autoantibodies against α‐enolase in a subset of NSCLC patients’ sera. When ‘Mean ODhealthy control sera + 3 SDhealthy control sera’ was used as the cut‐off point, the prevalence of this autoantibody was 27.7% in patients with NSCLC (26 of 94), 1.7% in healthy control subjects (1 of 60), and not detectable in sera from 15 patients with small cell lung cancer, 18 patients with gastrointestinal cancer and nine patients with Mycobacterium avium complex infection of lung. Immunohistochemical staining showed that expression of α‐enolase was increased in cancer tissues of NSCLC patients, and flow cytometric analysis confirmed the expression of α‐enolase at the surface of cancer cells. The combined detection of autoantibodies against α‐enolase, carcinoembryonic antigen and cytokeratin 19 fragment (CYFRA21‐1) enhanced sensitivity for the diagnosis of NSCLC. Therefore, autoantibodies against α‐enolase may constitute a promising biomarker for NSCLC. (Cancer Sci 2007; 98: 1234–1240)

Tumor budding in tumor invasive front predicts prognosis and survival of patients with esophageal squamous cell carcinomas receiving neoadjuvant chemotherapy.

In neoadjuvant chemotherapy for advanced esophageal cancers, complete tumor regression has been difficult to achieve, and tumor often remained after chemotherapy. However, the best method for evaluating the response to chemotherapy based on histopathologic examination of residual tumors has not been established.

Significant inhibition of human CD8(+) cytotoxic T lymphocyte-mediated xenocytotoxicity by overexpression of the human decoy Fas antigen.

Background. Human CD8+ CTL-mediated killing may be important for xenograft rejection. The purpose of this study was to explore the preventing methods for CTL-mediated xenocytotoxicity by overexpression of human decoy Fas, which lacks a death domain in its cytoplasmic region, by binding competition with endogenous pig Fas. Moreover, the cytoprotective effect of this CTL-killing of membrane-bound human FasL, which is resistant to metalloproteolytic cleavage, was also assessed. Methods. Human CTL were generated by the stimulation of human PBMC with swine endothelial cells (SEC) and human IL-2, subsequently a CD8+ population were selected by magnetic beads and employed as the effector cells. Stable SEC transfectants expressing either decoy Fas or membrane-bound FasL were established. Double-transfectants were also created. The amelioration of cytotoxicity to these transfectants was examined with 51Cr release assay. Results. Human CD8+ CTL were highly detrimental against parental SEC. This CTL-killing was strongly inhibited by anti-FasL mAb treatment, however partial suppression was observed by Concanamycin A treatment. The overexpression of either decoy Fas or membrane-bound FasL in SEC markedly inhibited CTL-xenocytotoxicity. The double expressions of these molecules also significantly reduced this xenocytotoxicity despite the low levels of expression of either decoy Fas or membrane-bound FasL. Conclusion. These findings indicate that the strong xenocytotoxicity of human CD8+ CTL is mediated mainly by the Fas/FasL pathway. The overexpression of either decoy Fas or membrane-bound FasL were quite effective in preventing CTL-killing. Furthermore, the combined expression of both molecules in pig cells may create a window of opportunity for prolonging xenograft survival.

Inhibition of donor-derived T cells trafficking into target organs by FTY720 during acute graft-versus-host disease in small bowel transplantation

In small bowel transplantation (SBTx), graft‐versus‐host disease (GVHD) is mediated by donor‐derived T cells recognizing host major histocompatibility complex (MHC) alloantigens, and represents an important immunological event influencing life in experimental and clinical situations. We evaluated the possibility that a new sphingosine 1‐phosphate receptor agonist, FTY720, could diminish GVHD in a rat SBTx model through traffic alteration of donor‐derived T cells in target organs. Heterotopic SBTx was performed using a parent (WF)‐into‐F1 (WF × ACI) rat combination. Recipient survival, body weight, histopathology, donor‐derived T cell subpopulation and cytokine production were compared with untreated controls. FTY720 inhibited lethality and histopathological changes in target organs when administered at 0·5 mg/kg, possibly due to sequestration of donor‐derived T cells in the intestinal graft. FTY720 caused a significant reduction in donor T cell numbers in target organs by promoting these cells to home into donor, but not recipient, secondary lymphoid tissues. FTY720 significantly decreased production of interferon (IFN)‐γ in target organs. These findings indicate that FTY720 effectively reduced recirculation of activated donor‐derived T cells and recruitment to target organs in GVHD, and was also associated with down‐regulated IFN‐γ production. These properties may offer the potential to treat ongoing GVHD in SBTx.

The potent role of graft-derived NKR-P1+TCRalphabeta+ T (NKT) cells in the spontaneous acceptance of rat liver allografts.

Background. The mechanism involved in the spontaneous acceptance of liver allografts in some rat strain combinations remains unclear. Immunoregulatory NKR-P1+TCRαβ+T (NKT) cells primarily produce IL-4 and IFN-γ, and enhance the polarization of immune responses to Th2 and Th1, respectively. The aim of this study was to clarify the role of graft-derived NKT cells in inducing the spontaneous acceptance of rat orthotopic liver transplantation (OLTx) Methods. The experimental groups were divided as follows: Group 1, BN to LEW “low responder (acceptor)” combination; Group 2, DA to LEW “high responder (rejector)” combination; naïve BN (Group 3) or LEW recipients (Group 4) with liver allografts from irradiated BN donors. The recipients had liver allografts from irradiated donors reconstituted from the following cell populations 24 hr before harvesting, spleen cells (SPCs, Group 5), Ig−SPCs (Group 6), Ig−NKR-P1−SPCs (Group 7), and Ig−TCRab−SPCs (Group 8) Results. In Group 1, the percent of graft-derived NKT cells harvested on day 7 posttransplant were significantly higher than in Group 2. In the case of BN liver allografts that had been irradiated and reconstituted with cell populations including NKT cells (Groups 5 and 6), the mean graft survival (MST) was extended to 39.2±5.7 and 38.8±8.0 days, respectively. In contrast, when NKT cells were excluded (Groups 7 and 8), the grafts were acutely rejected within MST of 17.8±4.0 and 18.8±7.7 days, respectively. The concentrations of IL-10 and TGF-β, but not IL-4 in Ig−GICs culture supernatants were predominant in the acceptor, whereas those with IFN-γ predominated in the rejector. Conclusions. Graft-derived NKT cells might be responsible for spontaneous acceptance in the rat OLTx.

A suspected [18F]fluorodeoxyglucose positron emission tomography-negative metastatic lymph node successfully diagnosed by laparoscopic staging in esophageal cancer: Report of two cases

An accurate preoperative staging is important for selecting an appropriate therapy for esophageal cancer. In particular, diagnosis of lymph node metastases influences the indication for radical surgery. [18F]Fluorodeoxyglucose positron emission tomography (FDG-PET) has been widely applied primarily as a useful tool for initial staging of esophageal cancer. However, false-negative cases sometimes make it difficult to select the appropriate treatment. We report two patients with esophageal cancer and PET-negative enlarged lymph node successfully diagnosed by laparoscopic sampling. This procedure did not only allow accurate histopathological staging, but also helped to select the optimal minimally invasive management. This technique can be recommended for patients with esophageal cancer in whom the diagnosis of enlarged lymph node cannot be confirmed by preoperative imaging.

Evidence-based Anticancer Kampo Medicine for Gastric Cancer

Herbal medicines originating in China have been used in East Asia for thousands of years, while taking root and evolving independently in countries like China, Korea, and Japan. In Japan, herbal medicines may be referred to as Chinese herbal medicine, Japanese herbal medicine, and traditional Japanese medicine or Kampo medicine. Until recently, the efficacy of Kampo medicines remained largely empirical and lacked rigorous scientific evaluations. However, more studies have begun to elucidate their basic mechanisms and pharmacological effects of some of the active ingredients using the latest biochemical and biomolecular methods. The number of clinical trials and epidemiological studies of Kampo medicines have exponentially increased as well. Here, we have reviewed the scientific and clinical evidence on Kampo medicines for gastric cancer into several categories, including effect in postoperative symptoms, effect against side effects of chemotherapy, direct or indirect effects against cancer, and the role in preventive medicine. In summary, several Kampo medicines appear to alleviate postoperative symptoms and side effects of chemotherapy, while others appear to exhibit potential antitumor and/or cancer-preventive activities. However, most data on their preventive effects against adverse effects of chemotherapy as well as on their antitumor activities are limited to in vitro or in vivo experiments. There are a few clinical studies on Kampo medicines for the treatment of postoperative symptoms, yet these studies are small and hard to draw any concrete conclusions. In the future, large randomized, controlled trials are required to establish clinical and scientific evidence of Kampo medicines in gastric cancer.