Stenotrophomonas maltophilia infection in hematopoietic SCT recipients: high mortality due to pulmonary hemorrhage

To clarify the clinical features and outcome of Stenotrophomonas maltophilia infection among hematopoietic SCT (HCT) recipients, we retrospectively reviewed the records of 1085 consecutive HCT recipients and identified 42 episodes in 31 HCT recipients with S. maltophilia infection. We compared these recipients with 30 non-HCT patients with S. maltophilia infection. The mortality rate in HCT recipients was significantly higher than that in non-HCT patients (relative risk 5.7, P=0.04), and we identified seven patients with pulmonary hemorrhage due to S. maltophilia, exclusively in the HCT cohort. Six of these latter seven patients died within 1 day from the onset of hemorrhage and the isolate was identified after death in most cases; one patient, who received empiric therapy for S. maltophilia and granulocyte transfusion, survived for more than 2 weeks. The patients with pulmonary hemorrhage had a more severe and longer duration of neutropenia, persistent fever despite of the use of broad-spectrum antibiotics, complication by pneumonia and higher C-reactive protein levels than those without pulmonary hemorrhage. In conclusion, S. maltophilia was associated with fulminant and fatal pulmonary hemorrhage in HCT recipients. Empiric therapy with antibiotics before the onset of pulmonary hemorrhage may be effective in HCT recipients who carry the conditions identified.

Insufficient ex vivo expansion of Valpha24(+) natural killer T cells in malignant lymphoma patients related to the suppressed expression of CD1d molecules on CD14(+) cells

BACKGROUND

Valpha24(+) natural killer T (NKT) cell is a human counterpart of mice Valpha14(+) NKT cell that has a regulatory role for innate and acquired potential antitumor activity. The efficient expansion of NKT cells is an obstacle to the clinical application of Valpha24(+) NKT cells for immunotherapy.

METHODS

We used mononuclear cells (MNC) obtained from the peripheral blood (PB) of normal healthy donor (HD) and malignant lymphoma (ML) patients before and after granulocyte colony-stimulating factor (G-CSF) treatment. MNC were cultured for 12 days with alpha-galactosylceramide (100 ng/mL) and interleukin-2 (IL-2; 100 U/mL).

RESULTS

The fold expansion of Valpha24(+) NKT cells was higher in HD than in ML patients (208 versus 0.00), despite comparable numbers of Valpha24(+) NKT cells before culture. G-CSF administration enhanced the predominance of Valpha24(+) NKT cell fold expansion in HD compared with ML patients (1935 versus 1.95). After treatment with G-CSF, the expression of CD1d molecules was up-regulated in CD14(+) cells from HD but not ML patients. The fold expansion of Valpha24(+) NKT cells and CD1d expression on CD14(+) cells was strongly correlated in both HD and ML patients (r(2)=0.84). However, replacement of a patient's CD14(+) cells with HD cells did not increase the efficacy of Valpha24(+) NKT cell expansion.

DISCUSSION

G-CSF-mobilized PB from ML patients has inhibitory characteristics for Valpha24(+) NKT cell expansion as a result of both monocytes and Valpha24(+) NKT cells. Multiple procedures would be needed for the expansion of patients' Valpha24(+) NKT cells.

Intensive glucose control after allogeneic hematopoietic stem cell transplantation: a retrospective matched-cohort study

Some studies have shown that intensive glucose control (IGC) improves outcome in the intensive care unit setting. However, it is the benefit of IGC in hematopoietic SCT (HSCT) that is not well defined. Between June 2006 and May 2007, IGC was maintained prospectively after allogeneic HSCT and clinical outcomes were compared with a cohort matched for conditioning regimen, source of stem cells, age and relation to donor. A stratified Cox regression model was used. There were no significant differences in baseline clinical characteristics. The median age was 43.5 years in both groups. The primary diagnosis was a hematologic malignancy. Patients in the IGC group had a lower glucose level (least-square mean, 116.4 vs 146.8 mg per 100 ml, P<0.001) compared to the standard glucose control group. The incidences of documented infections and bacteremia were significantly lower in the IGC group (14 vs 46%, P=0.004, 9 vs 39%, P=0.002, respectively). IGC tended to reduce the incidence of renal dysfunction (19 vs 37%, P=0.36) and the elevation of C-reactive protein (18 vs 38%, P=0.13). This study suggests that IGC has may have a beneficial effect after HSCT. IGC should be evaluated further in a large prospective, randomized study.

Evaluation of cytomegalovirus-specific cytotoxic T-lymphocytes in patients with the HLA-A*02 or HLA-A*24 phenotype undergoing hematopoietic stem cell transplantation

Cytomegalovirus-specific cytotoxic T-lymphocytes (CMV-CTL) are essential for the control of CMV reactivation. To monitor the quantity and function of CMV-CTL after hematopoietic stem cell transplantation (HSCT), two CMV epitopes that bind to HLA-A*0201 NLVPMVATV (A*02NLV) and HLA-A*2402 QYDPVAALF (A*24QYD) were evaluated for their immunological potential. Samples from patients with the HLA-A*02 or HLA-A*24 serotype were analyzed by tetramer, intracellular cytokine staining and enzyme-linked immunospot (ELISPOT) assay. There were significantly more A*02NLV-specific CMV-CTL than A*24QYD (23 x 10(6) vs 0.4 x 10(6)/l). The frequency of IFN-gamma-producing cells was also higher upon stimulation with A*02NLV than with A*24QYD (2.5 vs 0.1%/CD8). Furthermore, the magnitude of CMV-CTL expansion was two- to 50-fold when cells were cultured with A*02NLV, while only an insignificant increase was observed in culture with A*24QYD. Although the number of A*24QYD-specific CMV-CTL was very low in most of the HLA-A*24 patients, the incidence of CMV reactivation did not differ between those with HLA-A*02 and HLA-A*24 serotype alone. These results suggest that an epitope other than A*24QYD plays a major role in patients with HLA-A*24. Our study also showed that A*02NLV may be a useful epitope for monitoring CMV-CTL not only in patients with HLA-A*0201 but also in those with the A*0206 genotype.

Reduced-intensity stem cell transplantation from an HLA-identical sibling donor in patients with myeloid malignancies

The purpose of this study was to evaluate the feasibility and efficacy of allogeneic hematopoietic stem cell transplantation with a reduced-intensity regimen (RIST) in patients with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). In all, 36 patients (median age 55 years) underwent RIST from an HLA-matched related donor between September 1999 and December 2002. The diagnoses included AML (n=14), leukemia evolving from MDS (n=10), and MDS (refractory anemia with excess blasts n=6, refractory anemia n=6). The RIST regimen consisted of purine analog (cladribine or fludarabine)/busulfan, with or without antithymocyte globulin. The regimen was well tolerated, and 34 patients achieved durable engraftment and most achieved remission after RIST. A total of 17 patients developed grade II-IV acute GVHD, and 27 developed chronic GVHD. Eight patients relapsed, and five of them received antithymocyte globulin (ATG) as part of the preparative regimen. A total of 12 patients died (four disease progression, six transplantation-related complications, and two others). Estimated 1-year disease-free survival (DFS) in low- and high-risk groups was 85 and 64%, respectively. We conclude that RIST can be performed safely in elderly patients with myeloid malignancies, and has therapeutic potential for those who fail conventional chemotherapy. In view of the significant association between GVHD or ATG and DFS, defined management of GVHD following RIST should become a major target of clinical research.

Late hemorrhagic cystitis after reduced-intensity hematopoietic stem cell transplantation (RIST)

We reviewed medical records of 256 patients to investigate the frequency and characteristics of hemorrhagic cystitis (HC) associated with reduced-intensity stem cell transplantation (RIST) as opposed to conventional stem cell transplantation (CST); 137 patients underwent CST and 119 RIST. Diagnosis of HC was made based on two or more episodes of sterile, macroscopic hematuria with normal coagulation profiles, without any evidence of renal stones or genitourinary malignancy. Actuarial frequency of HC development in RIST group was 7.6% (9/119), which gave a cumulative annual incidence of 11.7%. In CST group, 13 of 137 patients (9.5%) developed HC, giving an estimated annual incidence of 9.7%. The probability of developing HC was similar between the two groups (P=0.77). The viral etiologies of HC, adenovirus (n=12) and BK virus (n=2), were documented in eight patients after RIST and in six after CST. HC was milder and of a shorter duration, with less blood transfusion requirements, in RIST group than in CST group. A multivariate analysis revealed that HC was associated with antiadenovirus antibody positivity in the recipients, total dose of busulfan, and chronic GVHD. Although HC following RIST is less severe than that following CST, it is still a significant problem.

Feasibility of reduced intensity hematopoietic stem cell transplantation from an HLA-matched unrelated donor

To evaluate the feasibility of reduced intensity stem cell transplantation (RIST) with bone marrow from a matched unrelated donor (MUD), we retrospectively investigated 20 patients with hematological disorders who received RIST in the Tokyo SCT consortium from January 2000 to October 2002. The preparative regimens were fludarabine-based (150-180 mg/m(2), n=18) or cladribine-based (0.77 mg/kg, n=2). To enhance engraftment, antithymocyte globulin (ATG) and 4 or 8 Gy total body irradiation (TBI) were added to these regimens in nine and 11 patients, respectively. GVHD prophylaxis was cyclosporine with or without methotrexate. In all, 19 achieved primary engraftment. Three developed graft failure (one primary, two secondary), and five died of treatment-related mortality within 100 days of transplant. Seven of the 19 patients who achieved initial engraftment developed grade II-IV acute GVHD, and seven of 13 patients who survived >100 days developed chronic GVHD. At a median follow-up of 5.5 months, estimated 1-year overall survival was 35%. Compared with a TBI-containing regimen, an ATG-containing regimen was associated with a high risk of graft failure (30 vs 0%, P=0.0737). This study supports the feasibility of RIST from MUD; however, procedure-related toxicities remain significant in its application to patients.

p16 Gene transfer increases cell killing with abnormal nucleation after ionising radiation in glioma cells

It is well established that cells synchronised at the G1–S phase are highly radiosensitive. In this study, p16-null human glioma cell lines were induced into G1 cell cycle arrest by adenovirus-mediated p16 gene transfer, and examined for radiation-induced cell killing. Clonogenic analysis and trypan blue extraction test showed that the p16 gene transfer enhanced radiation-induced cell killing in p16-null glioma cell lines. TUNEL assays and pulse-field gel electrophoresis confirmed that the radiation-induced cell killing of p16-transfected cells could be caused by a nonapoptotic mechanism. Gimsa staining demonstrated that irradiation alone or Ax-mock infection plus irradiation results in a slight increase in the frequency of cells with abnormal nucleus, compared to unirradiated uninfected or Ax-mock infected cells. However, Ax-hp16 or Ax-hp21 infection alone modestly increased the frequency of cells with abnormal nucleus (especially bi- and multinucleation), and 4-Gy irradiation of Ax-hp16 or Ax-hp21 infected cells substantially enhanced this frequency. These results suggest that there exists some unknown interaction between radiation and p16 in cytoplasm/membranes, which decreases cytokinesis and promotes abnormal nucleation. Thus, p16 expression prevented radiation-induced apoptosis by promoting abnormal nucleation, thereby leading to another mode of cell death.

Immune reconstitution following reduced-intensity transplantation with cladribine, busulfan, and antithymocyte globulin: serial comparison with conventional myeloablative transplantation

The primary object of the conditioning regimen for allogeneic reduced-intensity stem cell transplantation (RIST) is immunosuppression to achieve stable engraftment of donor cells, rather than bone marrow ablation. Therefore, immune reconstitution after RIST might be different from that after conventional stem cell transplantation (CST). In this study, 22 patients underwent RIST and 28 underwent CST. The RIST regimen consisted of cladribine (2-CdA; 0.11 mg/kg/day for 6 days), BU (4 mg/kg/day for 2 days), and rabbit anti-thymocyte globulin (ATG; 2.5 mg/kg/day for 2-4 days). The CST group received either the BU (4 mg/kg/day x 4 days)/CY (60 mg/kg/day x 2 days) (n=13) or CY (60 mg/kg/day x 2 days)/TBI (4 Gy/day x 3 days) regimen (n=15). All patients underwent transplantation with G-CSF-mobilized blood stem cells. Engraftment speed after RIST was fast and seven of 22 patients did not require platelet transfusion. We noted that the numbers of CD4+, CD4+CD45RA+, and CD4+CD45RO+ T cells after transplant in the RIST group were significantly lower than those in the CST group (P=0.0001 for both the comparisons). However, the reconstitution of CD20+ B cells was faster in the RIST group (P=0.0001). The response of T cells to PHA stimulation was lower in the RIST group (P=0.0001 on day 30 and P=0.02 on day 90). Nevertheless, there were no significant differences in the incidence of bacterial, fungal, or viral infections between the two groups. We concluded that our RIST regimen might delay laboratory-evaluated T-cell immune reconstitution compared to CST; however, the observed setbacks did not directly translate into clinically significant increases in infectious episodes.

Induction of graft-versus-autoimmune (GVA) disease effect against refractory psoriasis by complete donor-type chimerism and graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

A 67-year-old man with AML, who had a 21-year history of psoriasis without remission, received a reduced-intensity transplantation from an HLA-identical sibling. The preparative regimen consisted of busulfan and fludarabine. Graft-versus-host-disease (GVHD) prophylaxis was cyclosporine and methotrexate. Psoriasis was completely resolved on day 18. The subsequent clinical course was uneventful until day 42, when psoriasis recurred at the same sites as before RIST. Peripheral blood examined on day 63 showed mixed chimerism with 54% recipient type. Cyclosporine was rapidly tapered off over the next 2 weeks. On day 90, 100% donor-type chimerism was confirmed. Subsequently, psoriasis improved simultaneously with the occurrence of mucositis and rash as a manifestation of GVHD. Scattered erythematous patches of psoriasis disappeared again by day 105. We initiated 0.5 mg/kg prednisolone on day 119, and resumed cyclosporine on day 133. At 7 months after RIST, he still suffers from chronic GVHD, but his psoriasis remains in remission for the first time in 21 years. The anti-psoriasis effect of the conditioning is mild and transient, while the graft-versus-autoimmunity effect, related to the induction of complete donor-type chimerism and GVHD, is more profound and persisting. A graft-versus-autoimmunity effect lies in the delicate balance between alloimmunity and immunosuppressant used for GVHD prophylaxis/treatment.

Antitumor action of the PKC activator gnidimacrin through cdk2 inhibition

Daphnane-type diterpene gnidimacrin (NSC252940), isolated from a Chinese plant, exhibited antitumor activity against murine leukemias and solid tumors. At concentrations of 10(-9) to 10(-10) M, this agent strongly inhibited the growth of human tumor cell lines. In sensitive human leukemia K562 cells, gnidimacrin is a PKC activator that arrests the cell cycle in the G(1) phase by inhibiting cdk2 activity. A 4 hr exposure of K562 cells to gnidimacrin induced the CDK inhibitor p21(WAF1/Cip1), but this effect was transient and did not correlate temporally with the onset of G(1) arrest. Expression of cdc25A, a phosphatase that activates cdk2, was reduced during 24-hr exposure to gnidimacrin. Moreover, the suppression corresponded in a concentration- and time-dependent manner to both the inhibition of cdk2 activity and the mobility shift observed when cdk2 was electrophoresed on SDS-PAGE, indicating that the phosphorylation state of cdk2 must change. Cyclin E, the other regulator of cdk2 activity, was not influenced by gnidimacrin. These results suggest that gnidimacrin exerts antitumor activity through suppression of cdc25A and inhibition of cdk2 activity.

Adenovirus-mediated p16 gene transfer changes the sensitivity to taxanes and Vinca alkaloids of human ovarian cancer cells

BACKGROUND

Deletions and point mutations of the p16 gene are detectable in more than 50% of ovarian cancer cells. In this study, we examined the effect of p16 gene transduction on the growth of ovarian cancer cells and on the effect of anti-cancer agents.

MATERIALS AND METHODS

p16-null human ovarian cancer cell lines, SKOV-3 and OVCAR-5, were used in this study. We transduced the full-length human p16 gene using recombinant adenovirus (AxCA-hp16).

RESULTS

The spontaneous growth of these cells was significantly inhibited by hp16 transduction. MTT assay revealed that AxCA-hp16 infection induced chemoresistance in both cell lines. Flow cytometric analysis revealed that only hp16 -transduced SKOV-3, were arrested at the G1-phase for 3 days whereas those infected with AxCA-mock and OVCAR-5 infected with both recombinant viruses did not. Western blot analysis showed increased microtubule-associated proteins 4 (MAP4) in both cell lines.

CONCLUSION

These results suggest that in SKOV-3 cells, G1-arrest induced by p16-transduction prevents paclitaxel- and vindesine-induced cell death, and in OVCAR-5 cells, the other unknown mechanisms play a role of chemoresistance.

Overcoming multi-drug resistance using an intracellular anti-MDR1 sFv

We made an intracellular single-chain variable fragment (sFv) from the C219 monoclonal antibody that recognized the intracellular domain of the multidrug resistance (MDR) gene product, P-glycoprotein (P-gp). Immuno-cytochemistry using the FITC conjugated anti-C-myc tag antibody showed that the sFv protein was expressed in the cytoplasm of the cells. Although transfection of the sFv did not result in the down-regulation of P-gp expression in P-gp positive MDR cells as determined by flow cytometry analysis, Adriamycin (ADM) uptake and Rhodamine123 (Rh123) retention were increased by the C219 intra-cellular sFv transfection. The transfected cells exhibited a higher sensitivity to ADM using a 10-day colony formation assay. The conventional 3-day MTT assay showed the drug resistant tendency in C219 sFv transfected cell we tested. The growth rate of C219 sFv transfected cells was delayed in all non-MDR and MDR cells that might be the reason why C219 transfected cells exhibited the drug resistant tendency in the MTT assay. Despite this unexpected effect of C219 sFv on growth rate, our data suggest that the intra-cellular sFv technique could knockout MDR functionally and may offer a means of increasing the effectiveness of tumor chemotherapy.

Absence of endothelial cells, central necrosis, and fibrosis are associated with aggressive inflammatory breast cancer

We recently established a new human inflammatory breast cancer (IBC) xenograft (WIBC-9) originating from a patient with IBC. The graft was transplantable in BALB/c nude and severe combined immunodeficient (SCID) mice. WIBC-9 was frequently accompanied by lung metastasis and exhibited erythema of the overlying skin, reflecting its human counterpart. Histological study of the original tumor and WIBC-9 revealed invasive ductal carcinoma with a hypervascular structure of solid nests and marked lymphatic permeation in the overlying dermis. In the central part of the solid nests, absence of endothelial cells, central necrosis, and fibrosis were observed. In vitro, WIBC-9 formed tube-like structures and loops, reflecting its in vivo feature and its human counterpart. WIBC-9 exhibited aneuploidy, ErbB-2 gene amplification, and an absence of estrogen receptor and progesterone receptor, which is consistent with IBC. Comparative studies of WIBC-9, three established non-IBC xenografts, and a human breast cancer cell line (SK-BR3) by reverse transcription-PCR, ELISA, and immunohistochemistry indicated that certain human genes (interleukin 8, vascular epidermal growth factor, basic fibroblast growth factor, angiopoietin 13, Flt-1, Tie-2, and Tie-1) and certain murine genes (integrin alpha(v)beta3, flt-1, tie-2, vascular epidermal growth factor, and CD31) were overexpressed in exposure to tumor cells. The molecular basis and these unique histological features may be associated with aggressive IBC on angiogenic and nonangiogenic pathways.

Establishment and usefulness of an anti-human CD57 IgG1 monoclonal antibody

In the present study we established a new monoclonal antibody, JNK-1, which recognizes all cells recognized by CD57/HNK-1 mAb. JNK-1 and CD57 mAbs inhibited the binding of each other, suggesting that the molecules they recognize are either identical or sufficiently close to cause steric hindrance in the binding assay. JNK-1 mAb detected the 110-kDa protein, which is identical to the protein recognized by CD57/HNK-1 mAb in Western immunoblot analysis combined with immunoprecipitation. Therefore, JNK-1 mAb appears to recognize homogeneous molecules identified by the currently available CD57 mAb. Notably, JNK-1 mAb is composed of mouse IgG1 heavy chains, and thus can be used easily in immunoprecipitation, which cannot easily be performed with the available CD57 mAb because it is an IgM isotype. Thus, JNK-1, which is an IgG isotype, may present a useful tool to elucidate the CD57 protein.

Absence of mutations in the NBS1 gene in B-cell malignant lymphoma patients

BACKGROUND

Nijmegen breakage syndrome (NBS), also known as ataxia-telangiectasia (AT) variant, is an autosomal recessive disorder characterized by microcephaly, growth retardation, severe combined immunodeficiency and a high incidence of lymphoid carcinoma, the majority of which are B-cell lymphomas. To determine whether the NBS1 gene is a tumor suppressor gene in B-cell lymphoma, we screened B-cell malignant lymphoma (ML) for any evidence of NBS1 mutation.

MATERIALS AND METHODS

Sequence analysis of the NBS1 gene was performed from PCR products amplified from the DNA of 12 extracranial ML or RT-PCR products amplified from cDNA of 8 primary central nervous system lymphoma.

RESULTS

Direct sequence analysis revealed that no NBS1 mutations were present in any of these patients.

CONCLUSION

The present results suggested that the contribution of NBS1 mutations to B-cell ML was minimal, despite the fact that the NBS1 gene was causative factor in these cases.

Tetracycline-induced expression of an anti-c-Myb single-chain antibody and its inhibitory effect on proliferation of the human leukemia cell line K562

Ablation of c-Myb function might be an effective approach for the therapy of chronic myelogenous leukemia or other c-myb-dependent malignancies. To this end, we have previously used an intracellular anti-c-Myb single-chain antibody (sFv) to achieve the functional knockout of the c-Myb oncoprotein. In this study, we have employed a tetracycline-inducible system to control the expression of the sFv. A nuclear-localizing form of an anti-c-Myb sFv was cloned into a tet-regulated plasmid vector. Using a transient expression system in COS-1 cells, we observed that doxycycline (Dox) induced expression of the sFv in a dose-dependent manner, and that the sFv was localized mainly in the nucleus. The Dox-induced anti-c-Myb sFv also inhibited the transactivating activity of c-Myb in a dose-dependent manner. We subsequently confirmed the Dox-induced expression of the sFv in the leukemia cell line K562. Proliferation of the target leukemia cells was also inhibited. These results suggest that the anti-c-Myb sFv may represent a viable method for gene therapy of c-myb-dependent hematopoietic malignancies.

Undifferentiated carcinoma with lymphoid infiltration of the esophagus: a case report

This paper reports a surgically treated case of undifferentiated carcinoma with lymphoid infiltration of the esophagus. Histologically, most of the tumor consisted of undifferentiated carcinoma (non-small cell type) with lymphoid infiltration and a small portion showed features of poorly differentiated squamous cell carcinoma. Carcinoma with lymphoid infiltration in the stomach, breast or nasopharynx has a good prognosis, but in the esophagus this histological type is extremely rare and its characterization is unclear. This is only the sixth report to date of undifferentiated carcinoma with lymphoid infiltration of the esophagus.

High concentrations of recombinant adenovirus expressing p16 gene induces apoptosis in lung cancer cell lines

In this study, we discussed the effects of treatment with recombinant adenovirus expressing p16 (AX-p16) on cell growth and cell death. Ax-p16 at 10 m.o.i. groups showed growth inhibition 3 days after gene transfection, but the cells regrew and did not undergo cell death. On the other hand, Ax-p16 at 300 m.o.i. groups showed complete cell growth inhibition leading to cell death which was apparent 7 days after p16 gene transfection. In the high m.o.i. Ax-mock groups, cell death was marked just after infection, but had diminished by 7 days after infection. Downregulation of pRB was detected only in Ax-p16 at 300 m.o.i. groups. These data suggest that a) high m.o.i. condition of Ax-p16 gives therapeutic benefits due to the combined effects of adenovirus and high expression of p16; and b) the cell killing mechanism of the p16 transgene is different from that of high m.o.i. adenoviral infection.

Induction of specific T-cell tolerance by adenovirus-transfected, Fas ligand-producing antigen presenting cells

A major problem associated with adenovirus gene therapy is the T cell-mediated immune response, which is elicited by inoculation of the adenovirus vector and leads to rapid clearance of the virus and loss of transgene expression. In this study, the immune response to adenovirus was prevented by induction of specific T-cell tolerance by pretreatment with adenovirus-infected antigen-presenting cells (APC) that express Fas ligand. Compared with control-treated mice, the tolerized mice showed prolonged expression of lacZ upon administration of AdCMVlacZ 1 week after tolerance induction. In contrast to the control mice, the tolerized mice did not display proliferation of CD3+ T cells in the spleen in response to AdCMVlacZ. Tolerance induction also was indicated by the lower production of interferon-gamma and interleukin-2 by peripheral T cells isolated from AdCMVlacZ-challenged tolerized mice than by AdCMVlacZ-challenged control-treated mice. The T-cell tolerance was specific for the adenovirus as the T-cell responses to irrelative murine cytomegalovirus remained unimpaired. Our results indicate that adenovirus-specific T-cell tolerance can be induced by APCs that coexpress Fas ligand and adenovirus antigens. We propose that this new strategy can be used to induce tolerance to adenovirus vector gene therapy with resultant prolonged expression of the transgene.

Paracrine expression of a native soluble vascular endothelial growth factor receptor inhibits tumor growth, metastasis, and mortality rate

Vascular endothelial growth factor (VEGF) is a potent and selective vascular endothelial cell mitogen and angiogenic factor. VEGF expression is elevated in a wide variety of solid tumors and is thought to support their growth by enhancing tumor neovascularization. To block VEGF-dependent angiogenesis, tumor cells were transfected with cDNA encoding the native soluble FLT-1 (sFLT-1) truncated VEGF receptor which can function both by sequestering VEGF and, in a dominant negative fashion, by forming inactive heterodimers with membrane-spanning VEGF receptors. Transient transfection of HT-1080 human fibrosarcoma cells with a gene encoding sFLT-1 significantly inhibited their implantation and growth in the lungs of nude mice following i.v. injection and their growth as nodules from cells injected s.c. High sFLT-1 expressing stably transfected HT-1080 clones grew even slower as s.c. tumors. Finally, survival was significantly prolonged in mice injected intracranially with human glioblastoma cells stably transfected with the sflt-1 gene. The ability of sFLT-1 protein to inhibit tumor growth is presumably attributable to its paracrine inhibition of tumor angiogenesis in vivo, since it did not affect tumor cell mitogenesis in vitro. These results not only support VEGF receptors as antiangiogenic targets but also demonstrate that sflt-1 gene therapy might be a feasible approach for inhibiting tumor angiogenesis and growth.

Adenovirus-mediated p16 gene transfer prevents drug-induced cell death through G1 arrest in human glioma cells

This study examined the effects of full-length p16 gene transfer by recombinant adenovirus on cell growth and on sensitivity to CDDP or ACNU chemotherapies. We developed a recombinant adenovirus expressing the full-length human p16 gene (AxCA-hp16) by the COS-TPC method. AxCA-hp16 was infected into the p16-null human glioma cell line, U251MG. AxCA-hp16 infection inhibited proliferation of U251MG cells. A proliferation assay employing MTT showed that AxCA-hp16 infection induced chemoresistance, preventing CDDP-induced cell death (11- to 15-fold) and ACNU-induced cell death (80- to 92-fold). In the absence of AxCA-hp16, cell death was induced with CDDP or ACNU at 3 to 5 days after treatment, as demonstrated by Trypan-blue exclusion. Flow-cytometric analysis showed that CDDP or ACNU arrested cells in the G2 phase on day 1 and that cells re-entered the cycle on day 3. However, the cells infected with AxCA-hp16 after CDDP or ACNU treatment showed G1 arrest on day 5 after re-entering the cycle from G2 arrest on day 3. The cells infected with AxCA-hp16 before CDDP or ACNU treatment showed G1 arrest over the 5 days after the infection. This study demonstrated that G1 arrest induced with p16-gene expression prevents ACNU- or CDDP-induced cell death. The cell death induced by ACNU and CDDP therefore appears to occur in the phase after the G1/S check point.

Efficient generation of autologous peripheral blood-derived cytotoxic T lymphocytes against poorly immunogenic human tumors using recombinant CD80-adenovirus together with interleukin 12 and interleukin 2

To generate CTLs against poorly immunogenic human tumor cells, we transfected the human CD80 gene into the tumor cells using a replication-deficient adenovirus (Ad) vector. The successful surface expression of CD80 was obtained in both cultured tumor cell lines and primary cultured tumor cells. Transduction of CD80 alone was not sufficient to induce cytotoxicity of peripheral blood lymphocytes against allogeneic tumor cell lines except for melanoma cells. We, therefore, investigated a combined effect of CD80-Ad-infected tumor cells and interleukin 12 (IL-12). Although 7-day cultivation of autologous or allogeneic lymphocytes with CD80-Ad-infected tumor cells and IL-12 slightly enhanced cytotoxicity against some allogeneic tumor cells, no substantial cytotoxicity was observed against autologous tumor cells. When we extended the culture period to 14 days in the presence of IL-2, a prominent enhancement of cytotoxicity was observed against both allogeneic and autologous tumor cells. Cytotoxicity against autologous tumor cells, but not against allogeneic tumor cells, was efficiently inhibited by anti-CD3 monoclonal antibody. Furthermore, the selective cytotoxicity against a panel of targets indicated that the induced CTLs recognize specific antigens on autologous tumor cells. These results suggest that stimulation with a combination of IL-12- and CD80-modified tumor cells and subsequent expansion with IL-2 may efficiently generate tumor-specific CTLs from autologous peripheral blood lymphocytes. Our data imply that the combination of CD80 transduction and suitable cytokines is useful for enhancing antitumor immunity to poorly immunogenic human tumors.

Genetic immunotherapy by intrapleural, intraperitoneal and subcutaneous injection of IL-2 gene-modified Lewis lung carcinoma cells

The induction and augmentation of tumor non-specific immunity and of tumor-specific immunity by intrapleural, intraperitoneal and subcutaneous injection of interleukin-2 (IL-2) gene-modified Lewis lung carcinoma (LLC) cells (LLC-IL2) was tested in C57BL/6 mice. Intrapleural injection of LLC cells induced lung tumors with a malignant effusion, intraperitoneal injection induced peritoneal tumors with ascites and subcutaneous injection induced subcutaneous tumors. Intrapleural injection of irradiated LLC-IL2 cured pre-existing lung LLC tumors and extended the survival of the mice but did not affect survival of mice with pre-existing peritoneal tumors nor did it affect the growth of s.c. tumors. Intraperitoneal injection of irradiated LLC-IL2 cured pre-existing LLC peritoneal tumors and extended the survival of the mice but did not affect survival of mice bearing lung tumors nor did it affect the growth of s.c. tumors. Subcutaneous injection of irradiated LLC-IL2 did not affect the growth of preexisting s.c. tumors and also did not improve survival of mice bearing the lung or peritoneal tumors. Injection with irradiated LLC-IL2 by all routes, i.e., intrapleural, intraperitoneal and s.c., protected against subsequent re-challenge with LLC. Eight days after the initial immunization (early stage of immunization), non-adherent mononuclear cells in the peritoneal cavity of the mice treated with intraperitoneal injection of irradiated LLC-IL2 displayed enhanced cytotoxicity against LLC, B16-F10 and P815 cells, while the cytotoxic activity of spleen cells in the same mice did not change. The efficiency of induction of tumor-specific immunity was the strongest after intraperitoneal immunization and weakest after s.c. immunization. In vitro analysis using the spleen cells of mice immunized with irradiated LLC-IL2 suggested that CD8+ T cells play a key role in tumor-specific immunity.

[Clinical trial of IL-12 for cancer patients]

Interleukin-12 (IL-12) is a cytokine that stimulates T cells and NK cells. It induces interferon-gamma and plays a unique role in promoting type 1 T helper cell responses. In various animal models, IL-12 has shown a therapeutic effect controlling growth of primary and metastatic tumors at nontoxic doses. On the basis of these findings, IL-12 is now under clinical trial. Fever, flu-like, general fatigue, arthralgia, myalgia, leukopenia, liver dysfunction and so on are the reported toxicities of IL-12. A dramatic decrease of IL-12 AUC after consecutive dosing of IL-12, production of IL-10 and temporal elevation of NK and LAK activities after IL-12 administration have also been observed. Several patients achieve PRs after the administration, but dramatic clinical responses have never been reported. Intensive research on the mechanisms of antitumor response of IL-12 in cancer patients should be very important to the successful development of IL-12 as an anti-cancer agent.

Genetic immunotherapy by intrapleural, intraperitoneal and subcutaneous injection of IL-2 gene-modified Lewis lung carcinoma cells

The induction and augmentation of tumor non-specific immunity and of tumor-specific immunity by intrapleural, intraperitoneal and subcutaneous injection of interleukin-2 (IL-2) gene-modified Lewis lung carcinoma (LLC) cells (LLC-IL2) was tested in C57BL/6 mice. Intrapleural injection of LLC cells induced lung tumors with a malignant effusion, intraperitoneal injection induced peritoneal tumors with ascites and subcutaneous injection induced subcutaneous tumors. Intrapleural injection of irradiated LLC-IL2 cured pre-existing lung LLC tumors and extended the survival of the mice but did not affect survival of mice with pre-existing peritoneal tumors nor did it affect the growth of s.c. tumors. Intraperitoneal injection of irradiated LLC-IL2 cured pre-existing LLC peritoneal tumors and extended the survival of the mice but did not affect survival of mice bearing lung tumors nor did it affect the growth of s.c. tumors. Subcutaneous injection of irradiated LLC-IL2 did not affect the growth of preexisting s.c. tumors and also did not improve survival of mice bearing the lung or peritoneal tumors. Injection with irradiated LLC-IL2 by all routes, i.e., intrapleural, intraperitoneal and s.c., protected against subsequent re-challenge with LLC. Eight days after the initial immunization (early stage of immunization), non-adherent mononuclear cells in the peritoneal cavity of the mice treated with intraperitoneal injection of irradiated LLC-IL2 displayed enhanced cytotoxicity against LLC, B16-F10 and P815 cells, while the cytotoxic activity of spleen cells in the same mice did not change. The efficiency of induction of tumor-specific immunity was the strongest after intraperitoneal immunization and weakest after s.c. immunization. In vitro analysis using the spleen cells of mice immunized with irradiated LLC-IL2 suggested that CD8+ T cells play a key role in tumor-specific immunity.

Transformation of human glioma cell lines with the p16 gene inhibits cell proliferation

We examined the genomic status of the p16 gene in 5 human glioma cell lines by Southern blot analysis. The p16 gene was located in the 9p21 chromosomal region and homozygous deletion was detected in 4 of 5 (80%) human glioma cell lines and 5 of 15 (33%) clinical samples. We transfected the full-length human p16 gene into p16-null human glioma cell line, U251MG cells, using the plasmid vector pRc/CMV-p16 and evaluated the effect of p16 gene transfer on the growth suppression of malignant glioma cells. The transfection of p16 cDNA caused growth suppression through G1 cell cycle arrest in U251MG cells. We also examined the effect of p16 gene transfer on the chemosensitivity to cis-diamminedichloroplatinum II (CDDP), 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl) -3-nitrosourea hydrochloride (ACNU), and 5'-azacytidine (AZC). We did not detect any change in them after p16 gene transfer. These results might suggest that deletion of p16 genes promoted unrestrained growth in human glioma but has no relationship to the chemosensitivity to CDDP, ACNU and AZC.

Interferon-gamma-inducing factor gene transfection into Lewis lung carcinoma cells reduces tumorigenicity in vivo

To investigate the immunoregulatory effect of murine interferon-gamma-inducing factor (mIGIF), we transfected Lewis lung carcinoma (LLC) cells with a mammalian expression vector containing the mIGIF complementary DNA. The culture medium of the transfectant cells stimulated interferon-gamma (IFN-gamma) production by spleen cells in vitro in the presence of anti-CD3 antibody and markedly potentiated the effect of interleukin-12 (IL-12) on IFN-gamma production by spleen cells. mIGIF transfectant cells showed reduction of tumorigenicity and induction of an in vivo immuno-protective effect against the parental LLC cells. To examine the combined effect of systemic administration of recombinant IL-12 (rIL-12) and local mIGIF on the tumorigenicity, mice were challenged with LLC or transfectant cells on day 0, and the tumor-bearing mice were injected with 50 ng of rIL-12 intraperitoneally from day 7 to 11. Systemic rIL-12 showed an anti-tumor effect. However, mIGIF gene expression did not potentiate this effect of systemic rIL-12 in vivo.

Identification of cis-acting DNA elements of the human gamma-glutamylcysteine synthetase heavy subunit gene

Transcriptional activity of the 5'-flanking sequence of the human gamma-glutamylcysteine synthetase heavy subunit (gamma-GCSh) gene was investigated in COS7 cells transfected with hGH reporter constructs having successively deleted 5'-flanking sequence of the gamma-GCSh gene. Transcriptional activity was determined by the amounts of hGH secreted from the reporter constructs. Deletion of the sequence from -1,413 to -664 or -315 base pairs (bp) increased transcriptional activity from 100 to 138 or 136%. Further deletion from -315 to -241 bp, which contained an AP1 site, decreased transcriptional activity to 87%. Mutations introduced into the AP1 decreased transcriptional activity from 136 to 105%. These findings suggested that the AP1 increased transcriptional activity. When the sequence from -241 to -192 bp was deleted, transcriptional activity was restored from 87 to 128%. When this sequence was linked to the thymidine kinase promoter, it also decreased transcriptional activity by 38%. Deletion from -192 to -149, -116, or -108 bp did not significantly alter transcriptional activity. Further deletion of the GC-rich sequences from -108 to -70 and -28 bp dramatically decreased transcriptional activity from 135 to 87 and 34%, respectively. These findings indicate that multiple DNA elements, especially those in the proximal GC-rich sequences, are involved in the regulation of transcriptional activity of the gamma-GCSh gene.

Interleukin-2 gene transduction into freshly isolated lung adenocarcinoma cells with adenoviral vectors

We evaluated the efficiency of gene transduction and of gene expression by adenoviral vectors in human lung adenocarcinoma cells. Freshly isolated cancer cells were collected from pleural effusions in adenocarcinoma patients by centrifugation with a Percoll gradient. Adenoviral vectors resulted in effective gene transduction into human lung cancer cell lines and into freshly isolated lung adenocarcinoma cells. In an experiment using the beta-galactosidase (LacZ) gene, the Adex1CA vector with a regulatory sequence of chicken beta-actin as promoter and an enhancer derived from cytomegalovirus produced a higher transduction ratio and greater expression levels than adenoviral vectors with other promoter systems. Transduction with Adex1CA vectors containing the human interleukin-2 (IL-2) gene (Adex1CAhIL-2) resulted in enhanced secretion of IL-2 from gene-modified lung cancer cells. Treatment with normal human serum inhibited gene transduction by Adex1CAhIL-2 but did not inhibit gene expression after transduction by Adex1CAhIL-2. The secretion of IL-2 from the gene-modified cells, which were irradiated at 100 Gy before transduction, continued for 8 days. In a mouse model, the intrapleural injection of IL-2 gene-modified 3LL cells transduced by Adex1CAhIL-2 could cure the pre-existing lung tumours with malignant pleural effusions to induce tumor-specific immunity. But these therapies did not show any therapeutic benefit on the pre-existing tumor in subcutaneous region. These data suggest a potentially useful but limited clinical role of Adex1CAhIL-2 in gene therapy for lung cancer patients.

In vitro and in vivo modulation by rhizoxin of non-P-glycoprotein-mediated vindesine resistance

Rhizoxin is an antineoplastic drug that inhibits tubulin polymerization. In this study, we demonstrated that rhizoxin was approximately twice as active in vitro against a human small-cell lung cancer cell line with non-P-glycoprotein-mediated resistance to vindesine, H69/VDS, as against its parental line, H69. Tubulin polymerization in H69/VDS, demonstrated by Western blot analysis, was inhibited markedly by rhizoxin compared with that in H69, in a concentration-dependent manner. A drug-accumulation study showed that the intracellular rhizoxin level in H69/VDS was 15% lower than that in H69, whereas efflux from H69/VDS was enhanced slightly. These results indicate that enhanced inhibition of tubulin polymerization rather than increased intracellular drug concentration accounted for the higher sensitivity of H69/VDS to rhizoxin. In an experiment using mice with severe combined immunodeficiency and inoculated subcutaneously with H69/VDS, in vivo tumor growth was reduced markedly by three intermittent intraperitoneal doses of rhizoxin compared with that in mice inoculated with H69. Three weeks after the last rhizoxin dose, the relative treated/untreated tumor volumes were 0.29 for H69, but only 0.06 for H69/VDS, indicating that H69/VDS regrowth was minimal even after a 3-week treatment-free period. In conclusion, rhizoxin conquers vindesine resistance of a human small-cell lung cancer cell line in vitro and in vivo.

Long-term human hematopoiesis in SCID-hu mice bearing transplanted fragments of adult bone and bone marrow cells

An attempt was made to establish an SCID-hu murine model of long-term human hematopoiesis by coimplantation of a bone fragment and bone marrow (BM) cells from an adult human. The SCID-hu mice were treated with a cytokine mixture (recombinant human stem cell factor, interleukin-3, granulocyte/macrophage colony-stimulating factor, and granulocyte colony-stimulating factor) for 4 months and were then maintained for further 8 months under cytokine-free conditions. In the peripheral blood, spleen, and implanted bone fragments in the SCID-hu mice that had received both a bone fragment and BM cells, human CD59+ cells were detected 1 year after transplantation; however, they were not detectable in SCID-hu mice that had received either a bone fragment or BM cells only. Thus, implantation of both a bone fragment and BM cells appears to provide a model of long-term adult human hematopoiesis in SCID mice.

Correlation of gene-specific damage with cisplatin between human adenocarcinoma cells and peripheral blood mononuclear cells analyzed by polymerase chain reaction-stop assay

We investigated gene-specific damage in adenocarcinoma cells, obtained from pleural effusions of 9 primary lung cancer patients, induced by incubation with cisplatin for 3 h in vitro. The 2.7 kb fragment of the hypoxanthine phosphoribosyltransferase (HPRT) gene was amplified by the polymerase chain reaction (PCR) to quantify the DNA damage. A 7-fold difference in the extent of gene-specific damage among the patients was observed. Mononuclear cells (MNC) were obtained from freshly isolated blood from the same patients before they received chemotherapy. These cells were also incubated with cisplatin in vitro, and PCR amplification of the HPRT gene was carried out. A 4-fold variation of DNA damage among the patients was observed. Moreover, there was a linear correlation between the extents of the DNA damage in the tumor cells and MNCs (R2 = 0.676, P = 0.0016). These results suggest that the PCR-stop assay could be used to detect interindividual variations in the extent of gene-specific damage in both tumor cells and MNC from the same patients induced by cisplatin treatment. In conclusion, MNC could be used to analyze cisplatin-induced gene-specific damage in cancer patients whose tumor cells are inaccessible.

In vivo screening models of cisplatin-resistant human lung cancer cell lines using SCID mice

In vivo screening models of a cisplatin (CDDP)-resistant human small-cell lung cancer cell (SCLC) line, H69/CDDP, and a non-small-cell lung cancer cell (NSCLC) line, PC-14/CDDP, were evaluated. The transplantability of the tumor xenografts to SCID mice was more than 90%. Tumor xenografts of H69/CDDP and PC-14/CDDP showed CDDP resistance during in vivo treatment. The novel anticancer agent 254-S showed only a partial effect on the growth of H69/CDDP and PC-14/CDDP while ormaplatin showed no cross resistance to CDDP. The in vivo results correlated well with the results of the in vitro MTT assay. In this in vivo sensitivity test, H69/CDDP and PC-14/CDDP were more sensitive to ormaplatin than its parental cell lines. In vivo sensitivity testing using SCID mice bearing transplanted CDDP-resistant tumors was shown to be useful for evaluating the effects of new anti-cancer drugs, especially those that might overcome CDDP resistance.

In vitro and in vivo growth of B16F10 melanoma cells transfected with interleukin-4 cDNA and gene therapy with the transfectant

In an attempt to develop the most effective cytokine gene therapy, we transfected mouse interleukin(IL)-2, mouse IL-4, and human IL-6 cDNAs into mouse melanoma cells, B16F10. Transfection with IL-4 cDNA decreased the tumorigenicity of B16F10 most strongly. We investigated whether gene therapy with IL-4-transfected B16F10 cells was possible. Flow-cytometric analysis showed that major histocompatibility complex class I and II expression in B16F10 and IL-4-cDNA-transfected B16F10 (B16F10-IL4) cells did not differ. Doubling times of B16F10 and B16F10-IL4 were 20.1 and 21.1 h respectively. The growth of B16F10 cells was retarded if C57BL/6 mice were inoculated with B16F10-IL4 at the contralateral sides. When 5 x 10(5) B16F10 cells were transplanted subcutaneously into the flanks of C57BL/6 mice, they all developed a tumor mass, whereas no tumor masses formed in those transplanted with B16F10-IL4 cells within 60 days. No nude, severe combined immunodeficient or beige mice were able to reject parental B16F10 or B16F10-IL4 cells, although, B16F10-IL4 tumor growth in all these immunodeficient mice was slower than that of B16F10. Therefore, we concluded that T and natural killer cells are necessary for rejection of B16F10-IL4 tumor cells.