A gene encoding human gastric signet ring cell carcinoma antigen recognized by HLA-A31-restricted cytotoxic T lymphocytes

SUMMARY: We previously reported acid-extracted natural antigenic peptide (F4.2 [YSWMDISCWI]) of a gastric signet ring cell carcinoma HST-2 cells, recognized by HLA-A*31012-restricted autologous cytotoxic T lymphocytes, TcHST-2 line. In this study, the full-length cDNA (1101 bp), termed c98, predicting a protein composed of 170 amino acids was obtained. Because TcHST-2 cells could lyse the HLA-A31 antigen (+) allogeneic tumor cells that were introduced with c98 gene, this gene was suggested to possess antigenicity. Beginning at N-terminal 61 amino acid, the N-terminal six amino acid sequence that is completely identical to F4.2 was present in c98; however, a sequence of four amino acids in C-terminal was not found. Nevertheless, this peptide, c98(61-70), seemed to be immunogenic, because cells pulsed with c98(61-70) peptide were lysed in a dose-dependent manner by TcHST-2 cells. The c98 gene was expressed ubiquitously in tumor cells as well as in normal tissues. However, some tumor cells, including HST-2 cells, expressed this antigen in a high content, and such cells were lysed by TcHST-2 cells in the context of HLA-A31 antigen. However, TcHST-2 cells did not lyse cells that expressed lower amounts of c98 than HST-2 cells. These data suggested that c98-gene product and/or c98(61-70) peptides could be used as a candidate for tumor vaccines in cancer immunotherapy.     

Clinicopathological and prognostic characteristics of CD56-negative multiple myeloma

We analysed CD56 expression in 70 patients with multiple myeloma (MM) to determine its clinicopathological and prognostic significance. Fifty-five (79%) patients were CD56+. CD56- patients (n = 15) had higher beta2 microglobulin levels and a higher incidence of extramedullary disease, Bence Jones protein, renal insufficiency and thrombocytopenia than CD56+ patients. Their myelomas more frequently had a plasmablastic morphology. Overall survival was significantly lower in CD56- than CD56+ patients (22 vs 63 months, P = 0.0002). We conclude that CD56- MM is a discrete entity associated with more aggressive disease. The higher incidence of plasmablastic cases suggested that CD56- MM may develop from a less mature plasma cell than CD56+ MM.     

Rationale for extensive lymphadenectomy in early gastric carcinoma.

The incidence of nodal metastasis in early gastric carcinoma (EGC) is 10-20%. However, the optimal nodal dissection for early gastric carcinoma has not been established. A retrospective study was conducted in 392 consecutive patients who underwent potentially curative distal gastrectomy for EGC between 1962 and 1990. Of these 295 patients treated after September 1972 were prospectively entered into an extensive lymphadenectomy protocol. These patients were compared with 97 patients with simple gastrectomy in respect of the causes of death after surgery and the 10 year disease-specific survival rate. The incidence of nodal metastasis in early gastric carcinoma patients was 13.0%. Operative mortality from extensive lymphadenectomy was almost the same as from simple gastrectomy (2.0% and 2.1% respectively). Extensive lymphadenectomy provided a significantly higher 10 year survival rate than limited lymph node dissection (97.9% vs 88.1% respectively; P < 0.005). Among patients with nodal metastasis, the survival rate following extensive lymphadenectomy was significantly higher than that after simple gastrectomy (87.5% vs 55.6%; P = 0.018). Among patients without nodal metastasis, there was no difference between the two groups in the survival rate (99.4% and 96.7% respectively; P = 0.12). Multivariate analysis using the Cox proportional hazards model disclosed two significant independent prognostic factors on disease-specific survival, the nodal involvement (risk ratio: 8.4; P < 0.0001) and the extent of lymph node dissection (risk ratio: 5.8; P < 0.005). Extensive nodel dissection appears to prevent recurrence and to improve the cancer-specific survival in EGC patients with nodal metastasis.     

Detection of replicative intermediate with closed terminus of Bombyx densonucleosis virus

Summary. Two kinds of Bombyx densonucleosis virus (BmDNV), BmDNV-1 and 2, have been isolated from sericultural farms in Japan or China. These viruses are classified into the family Parvoviridae because of the small spherical virus particle containing a single-stranded linear DNA genome. Recent studies on the genome structure of these viruses suggested that BmDNV-2 was a new type of virus with unique replication mechanism, though that of BmDNV-1 was similar to parvoviruses. However, details about the replication mechanism of BmDNVs have not been reported so far. Here, in order to elucidate the difference on replication mechanism between BmDNVs and parvoviruses, we analyzed the structure of the replicative intermediate (RI) of BmDNV DNAs by CR using specific primers designed for detection of RI with closed terminal structure (RI-CT) which is expected to be formed by replication with self-priming mechanism. PCR using the DNA from the cells infected with BmDNV-1 could detect the expected DNA fragment, showing the existence of RI-CT. On the other hand, no fragment could be amplified from the virion DNA of the BmDNVs and the DNA extracted from BmDNV-2-infected cells, respectively. These observations strongly suggested that the BmDNV-1 replicates with the “self-priming and hairpin-transfer” mechanism similar to the human parvoviruses, while BmDNV-2 does not. Received June 20, 1996 Accepted September 27, 1996     

Dynamic expression patterns of G protein-regulated inducer of neurite outgrowth 1 (GRIN1) and its colocalization with Galphao implicate significant roles of Galphao-GRIN1 signaling in nervous system

GRIN1 (Gprin 1) is a signaling molecule coexpression of which with constitutively active form of Galphao can stimulate neurite extensions in Neuro2a cells, yet its in vivo roles remain elusive. Here, we examine expression profiles of GRIN1 during mouse development by in situ hybridization (ISH) and immunohistochemistry. ISH analysis revealed that GRIN1 expression was limited to the nervous system at all developmental stages tested: in the central nervous system, GRIN1 expression occurred within the entire embryonic mantle zones, while it became restricted to sets of nuclei at postnatal to adult stages. Immunohistochemistry using a GRIN1-specific antibody demonstrated that GRIN1 colocalized with Galphao at neuronal dendrites and axons, but it was not detected in glial cells. These results suggest that Galphao-GRIN1 pathway could mediate significant roles in neuronal migration and differentiation at embryonic stages and exert functions in wiring and/or maintenance of specific neural circuitries at postnatal to adult stages.     

Deletion 6p23 and add(11)(p15) leading to NUP98 translocation in a case of therapy-related atypical chronic myelocytic leukemia transforming to acute myelocytic leukemia

A NUP98 gene translocation occurring with a del(6p23) and an add(11)(p15) was determined in a 61-year-old patient with therapy-related atypical chronic myelocytic leukemia after complete remission from acute promyelocytic leukemia that eventually underwent clonal evolution and transformed to CD56-positive acute myelocytic leukemia (French-American-British classification M0). Precise chromosome analysis by G-banding, spectral karyotyping analysis, and dual-color fluorescence in situ hybridization showed this abnormality as 46,XY,del(6)(p23),add(p15). ish del(6)(NUP98-,D6Z1+),der(7)(NUP98+,D7Z1+),der(11)(NUP98+,D11Z1). A split signal of NUP98 was observed in 68.4% of the 117 cells analyzed, which clearly indicated that the NUP98 partially translocated to chromosome 7. However, the potential fusion partner of the NUP98 was not HOX family or DEK. The fusion gene has not been found by a differential display method. The significance of simultaneously combined del(6)(p23), which also has been reported with secondary leukemogenesis, has not been elucidated. Additional karyotype abnormalities evolved increasingly, and leukocytosis with blasts with more complex karyotypic abnormalities appeared 5 months later. Careful and continuous analysis of karyotype change clarified the process of the clonal evolution after NUP98 translocation. Further investigation of molecular characterization of this NUP98 translocation and interaction with 6p23 abnormalities might be worthwhile for understanding leukemogenesis.     

Selective dysfunction of the vagal component of the baroreflex following cerebral ischemia: protection by ifenprodil and flunarizine

Baroreflex sensitivity assessed from the phenylephrine-induced reflex bradycardia was significantly decreased following 5 min global incomplete cerebral ischemia in pentobarbitalized dogs. Although bilateral vagotomy in the cervical region decreased baroreflex sensitivity by about 50% in sham-operated animals, it hardly affected the baroreflex in animals subjected to ischemia. The extent of the decrease in the influence of vagotomy on the baroreflex was dependent on the severity of ischemia in the dorsal medulla oblongata. In animals vagotomized before ischemia, no significant decrease in baroreflex sensitivity was observed following ischemia. Pretreatment with ifenprodil or flunarizine, 1 mg/kg i.v., 5 min prior to ischemia prevented the post-ischemic decrease in baroreflex sensitivity. Vagotomy decreased baroreflex sensitivity during the reperfusion period in these treated animals. These results suggest that the post-ischemic attenuation of reflex bradycardia may be due to a selective dysfunction of the vagal component of baroreflex, which can be prevented by the cerebroprotective agents.     

Mechanism of the immunosuppressive effect in vivo of novel immunosuppressive drug beta-SQAG9, which inhibits the response of the CD62L+ T-cell subset

INTRODUCTION: We synthesized sulfo-glycolipid, beta-SQAG9 (designate square beta-SQAG9 liposome, because it efficiently forms a liposome structure) that possessed immunosuppressive effects such as inhibition of T-cell responses in human allogeneic MLR and skin allograft survival in rats, and bound to CD62L (L-selectin) in vitro. In this study, we further investigated the immunosuppressive mechanism in vivo by beta-SQAG9 liposome in a skin-allografted rat model. METHODS: ACI rats (RT1(a)) were grafted skin of LEW rats (RT1(1)) treated with PBS or beta-SQAG9 liposome IV once a day for 7 days. Subsequently, we investigated the population of T cells and CD62L(+) T-cell subset in the spleen, axillary lymph nodes (ALNs), and peripheral blood of skin-allografted rats by two-color flow cytometry. RESULTS: Five of 11 (45.5%) rats that were treated with 50 mg/kg beta-SQAG9 liposome showed graft survival and another showed moderate rejection in graft. The CD62L(+) T-cell subset population in ALNs of beta-SQAG9 liposome-treated rats decreased in a dose-dependent manner. No significant difference in the T-cell population was observed between the beta-SQAG9 and control groups. These data suggest that beta-SQAG9 could bind to the CD62L(+) T-cell subset in vivo as well as in vitro and affect T-cell migration, which might lead to T-cell tolerance in vivo.