Itaru Kataoka

Elevation of serum hepatocyte growth factor during granulocyte colony-stimulating factor-induced peripheral blood stem cell mobilization.

We examined serum levels of the angiogenic factors, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and hepatocyte growth factor (HGF), in normal donors for allogeneic peripheral blood stem cell (PBSC) transplantation. Granulocyte colony‐stimulating factor (G‐CSF) (filgrastim 400 μg/m2/d) was administered to 23 donors for 5 d and aphereses were performed on days 4 and 5. Although bFGF remained at similar levels after G‐CSF treatment, serum VEGF and HGF levels increased 1·5‐fold (n = 13; P = 0·02) and 6·8‐fold (n = 23; P < 0·0001) respectively. The serum HGF level before G‐CSF administration on day 1 correlated inversely with mobilized CD34+ cell numbers. Time course kinetics of HGF showed that on the day after G‐CSF administration (day 2), serum HGF levels increased to 3678 pg/ml. For auto PBSC mobilization with chemotherapy and G‐CSF 200 μg/m2/d (n = 8), we observed similar HGF elevation, which appeared to be dose‐dependent on the G‐CSF administered.

Clinical impact of graft-versus-host disease against leukemias not in remission at the time of allogeneic hematopoietic stem cell transplantation from related donors. The Japan society for hematopoietic cell transplantation working party

Summary:Acute graft-versus-host disease (GVHD) increases post-transplant mortality and morbidity, but exerts a potent graft-versus-leukemia (GVL) effect. To clarify the impact of GVHD on outcome after transplant in aggressive diseases, patients with acute myeloid or lymphoblastic leukemia (AML, n=366 or ALL, n=255) in nonremission states, or chronic myelogenous leukemia (CML, n=180) in accelerated phase (AP) or blastic crisis (BC), who received allogeneic hematopoietic stem cell transplantation (HSCT) from a related donor between 1991 and 2000, were analyzed. Significant improvement in overall and disease-free survival (DFS) was detected with grade I acute GVHD in AML (P=0.0002 for overall survival and 0.0009 for DFS, respectively) and in CML (P=0.0256 and 0.0366, respectively), while the trend towards improved survival was observed in ALL. Relapse rate was lower in grade I acute GVHD than in grade II in all three diseases, suggesting that treatment for grade II GVHD may compromise the GVL effect associated with GVHD. Chronic GVHD was found to suppress relapse in CML and ALL, but not in AML, although no improvement in survival was observed in any disease category. Our results suggest that treatment for grade II acute GVHD may need to be attenuated in transplant for refractory leukemias.

Vandetanib is effective in EGFR-mutant lung cancer cells with PTEN deficiency.

The effectiveness of vandetanib, an agent that targets RET, VEGFR and EGFR signaling, against EGFR-mutant lung cancer cells with PTEN loss was investigated. Two EGFR mutant non-small cell lung cancer (NSCLC) cell lines, PC-9 (PTEN wild type) and NCI-H1650 (PTEN null), were used. We transfected an intact PTEN gene into H1650 cells and knocked down PTEN expression in PC-9 cells using shRNA. The effectiveness of gefitinib and vandetanib was assessed using a xenograft model. While PC-9 cells were more resistant to vandetanib than gefitinib, H1650 cells were more sensitive to vandetanib than gefitinib. Both gefitinib and vandetanib suppressed the activation of EGFR and MAPK in H1650 cells, although phosphorylated AKT levels were not affected. In an H1650 cell xenograft model, vandetanib was also more effective than gefitinib. Although PTEN-transfected H1650 cells did not show restoration of sensitivity to gefitinib in vitro, the xenograft tumors responded to gefitinib and vandetanib. Knockdown of PTEN in PC-9 cells caused resistance to gefitinib. In conclusion, vandetanib might be effective in NSCLC with EGFR mutations that lack PTEN expression. The contribution of PTEN absence to vandetanib activity in NSCLC cells harboring EGFR mutations should be further examined.

The type 1 CD10/neutral endopeptidase 24.11 promoter: functional characterization of the 5¢-untranslated region

Summary. The cell surface zinc metalloproteinase CD10/neutral endopeptidase 24.11 (NEP) is expressed on normal and malignant lymphoid progenitors, granulocytes and a variety of epithelial cells. Because CD10/NEP functions as part of a regulatory loop that controls local concentrations of peptide substrates and associated peptide‐mediated signal transduction, its role in each tissue is different depending on the availability of substrate. To characterize further how this widely distributed molecule is regulated differentially in each tissue, we analysed the major type 2 CD10/NEP promoter and found three functionally important transcription factor binding sites, one of which was identical to CCAAT‐binding transcription factor/nuclear transcription factor Y. In this report, we analyse the type 1 CD10/NEP promoter and found a functionally important transcription factor binding site in the 5′‐untranslated region. The results of the competition and supershift experiments demonstrated that the functionally important transcription factor was identical to Sp1. Our results suggest that ubiquitously expressed Sp1 may play an important role in differentiation stage‐specific regulation of CD10/NEP expression in lymphoid lineage.

The effect of adding rituximab to CHOP-based therapy on clinical outcomes for Japanese patients with diffuse large B-cell lymphoma: a propensity score matching analysis.

We conducted a retrospective analysis to evaluate the impact on clinical outcomes of adding rituximab to cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) treatment for diffuse large B-cell lymphoma (DLBCL) patients in Japan. A propensity score method was used to compensate for the non-randomized study design. From January 2000 to December 2004, 378 patients who were newly diagnosed with DLBCL at 13 institutes were enrolled: 123 in the rituximab plus CHOP-based chemotherapy (R+) group, and 255 in the CHOP-based chemotherapy only (R−) group. The complete response rate was significantly higher in the R+ group than in the R− group (77.7 vs. 69.4%, P < 0.001). The progression-free survival (PFS) at 2 years was 62.4% in the R+ group and 57.0% in the R− group. The 2-year overall survival (OS) was 76.9% for the R+ group and 70.5% for the R− group. A multivariate analysis revealed that the addition of rituximab was a strong independent prognostic factor for PFS (hazard ratio 0.64, 95% CI 0.43–0.96, P = 0.031). A subgroup analysis revealed that R+ particularly benefited younger patients (hazard ratio 0.25, 95% CI 0.08–0.75, P = 0.013). IPI also showed significant impact for PFS (hazard ratio 1.82, 95% CI 1.55–2.14 for one score increase, P < 0.001) as well as OS (hazard ratio 2.10, 95% CI 1.71–2.57, P < 0.001). In summary, the addition of rituximab to CHOP-based chemotherapy results in better outcomes for Japanese DLBCL patients, particularly younger patients.

Characterization of the short isoform of Helios overexpressed in patients with T‐cell malignancies

In an earlier report, we demonstrated overexpression of a short isoform of Helios, Hel‐5, which lacks three of four N‐terminal zinc fingers, in patients with adult T‐cell leukemia/lymphoma. Here, we characterized Hel‐5 using immunoprecipitation, and gel shift and luciferase promoter assays, and found that Hel‐5 lacks the repressor function observed with a full‐length isoform of Helios. Moreover, Hel‐5 associates with the full‐length isoforms of the Ikaros gene family, Ikaros, Aiolos and Helios, and inhibits their DNA binding activity when present in excess, leading to dominant‐negative effects on the full‐length isoforms of the Ikaros gene family. Our results suggest a critical role for Helios in the mechanism of leukemogenesis. (Cancer Sci 2007; 98: 182–188)

Abstract 3620: Efficacy of Vandetanib on EGFR mutant lung cancer cells with PTEN loss

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC Introduction EGFR gene is frequently mutated in non-small cell lung cancer (NSCLC) of never smokers, especially in Asian ethnicity. The mutations often predict dramatic response to EGFR-tyrosine kinase inhibitors (TKIs) like gefitinib. PTEN is a tumor-suppressor gene deactivating PI3K in downstream of EGFR signaling. Approximately 2% to 9% in NSCLC tumors were considered to be PTEN loss. PTEN loss and EGFR mutation co-occurred in 1 out of 24 EGFR mutant patients with lung adenocarcinoma (Sos, et al. Cancer Res 69, 2009). PTEN loss was considered to represent primary or acquired resistance to EGFR-TKIs. Therefore, a new strategy is needed to break through for the resistance due to PTEN loss. Objective We clarify the effectiveness of vandetanib, EGFR and vascular endothelial growth factor receptor (VEGFR) inhibitor, against lung cancer cell lines harboring EGFR mutations with PTEN loss. Materials and methods: Two EGFR mutant (deletion in exon19) NSCLC cell lines, PC-9 (PTEN wild type) and NCI-H1650 (PTEN loss) were used. Other two cell lines with PTEN loss, prostate cancer cell line (PC-3) and glioblastoma cell line (U-87MG) were also examined. We transfected intact PTEN gene into H1650 cells and knocked down PTEN expression in the PC-9 cells using shRNA. Antiproliferative activity was determined by MTT assay in terms of 50% inhibitory concentration (IC50) values. We also examined the effectiveness of the drugs (15 mg/kg/day) in xenograft model. Protein expression profile was examined by Western blotting. Expression of VEGFR mRNA levels was also assessed by RT-PCR. Results PC-9 cells were more resistant to vandetanib (IC50: 0.08 μM) than to gefitinib (IC50: 0.01 μM). However, mean IC50 values of vandetenib were significantly lower than those of gefitinib against H1650 cells (2 μM vs 25 μM), PC-3 cells (8 μM vs 25 μM), and U87MG cells (6 μM vs 28 μM) with PTEN loss. EGFR downstream signals including pAKT, pMAPK, and pSTAT3, and VEGFR were not different in the H1650 cells treated with vandetanib or gefitinib. In the xenograft model using H1650 cells, vandetanib was also more effective than gefitinib. Although PTEN transfected H1650 cells did not restore sensitiveness to gefitinib in vitro, the xenograft tumors responded to gefitinib as well as vandetanib. Knockdown of PTEN lead six times more resistance to gefitinib in PC-9 cells. Conclusion PTEN loss may play a role to determine the sensitivity to gefitinib in NSCLC with EGFR mutations. Vandetanib is more effective in NSCLC with EGFR mutation and PTEN loss. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3620.