Young-Ik Son

Metabolic Tumor Volume of [18F]-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Predicts Short-Term Outcome to Radiotherapy With or Without Chemotherapy in Pharyngeal Cancer

Purpose: This study aimed to investigate whether metabolic tumor volume (MTV) measured from [18F]-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) predicts short-term outcome to radiotherapy with or without chemotherapy and disease-free survival (DFS) in patients with pharyngeal cancers. Experimental Design: The MTVs of primary sites with or without neck nodes were measured in 82 patients. Short-term outcome was assessed using the treatment response evaluation by the Response Evaluation Criteria in Solid Tumors and recurrence events during follow-up (complete response/no recurrence or residual disease/recurrence). Results: A total of 64 patients had complete response/no recurrence as of the last follow-up. A cutoff of 40 mL for the MTV was the best discriminative value for predicting treatment response. By univariate analyses, patients with MTV >40 mL showed a significantly lower number of complete response/no recurrence than did patients with MTV ≤40 mL [68.2% versus 87.8%; hazard ratio (HR), 3.34; 95% confidence interval (95% CI), 1.09-10.08; P = 0.03], as is the same in tumor-node-metastasis stage (87.5% for I-II versus 90% for III versus 63.8% for IV; P = 0.02). However, MTV was only a significant predictor of short-term outcome by multivariate analyses (HR, 4.09; 95% CI, 1.02-16.43; P = 0.04). MTV >40 mL indicated a significantly worse DFS than MTV ≤40 mL (HR, 3.42; 95% CI, 1.04-11.26;P = 0.04). The standardized uptake value for the primary tumor did not show any correlation with treatment outcome or DFS. Conclusion: MTV has a potential value in predicting short-term outcome and DFS in patients with pharyngeal cancers. (Clin Cancer Res 2009;15(18):5861–8)

Interleukin 12 Gene Therapy of Cancer by Peritumoral Injection of Transduced Autologous Fibroblasts: Outcome of a Phase I Study

A phase I dose-escalation clinical trial of peritumoral injections of interleukin 12 (IL-12)-transduced autologous fibroblasts was performed in patients with disseminated cancer for whom effective treatment does not exist. The goals of this study were to assess the safety and toxicities as well as the efficacy, and ancillarily the immunomodulatory effects, of peritumoral IL-12 gene transfer. Primary dermal fibroblasts cultured from the patients were transduced with retroviral vector carrying human IL-12 genes (p35 and p40) as well as the neomycin phosphotransferase gene (TFG-hIL-12-Neo). Patients received four injections at intervals of 7 days. Nine patients were enrolled in this dose-escalation study, with secreted IL-12 doses ranging from 300 ng/24 hr for the first three patients to 1000, 3000, and 5000 ng/24 hr for two patients in each subsequent dosage level. Although a definite statement cannot be made, there appears to be perturbation of systemic immunity. Also, the locoregional effects mediated by tumor necrosis factor alpha (TNF-alpha) and CD8+ T cells were observed with tumor regression. Treatment-related adverse events were limited to mild to moderate pain at the injection site; clinically significant toxicities were not encountered. Transient but clear reductions of tumor sizes were observed at the injected sites in four of nine cases, and at noninjected distant sites in one melanoma patient. Hemorrhagic necrosis of tumors was observed in two melanoma patients. These data indicate that gene therapy by peritumoral injection of IL-12-producing autologous fibroblasts is feasible, and promising in patients with advanced cancer.

A novel bulk-culture method for generating mature dendritic cells from mouse bone marrow cells

We established a novel culture method for generating dendritic cells (DC) from mouse bone marrow (BM) cells. Unfractionated bulk BM cells were cultured in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4) for 5-7 days and a DC population was isolated by gradient centrifugation with 14.5% (w/v) metrizamide. Through this method, 30-40 x 10(6)/mouse DC with 85-95% purity was obtained on day 7; this yield was higher than those of conventional DC generated by Inabas method either with GM-CSF alone (conventional-GM DC) or GM-CSF and IL-4 (conventional-GM/4 DC). Bulk-cultured DC have a more matured phenotype than both conventional-GM and -GM/4 DC as shown by higher expression of CD86, MHC class II and CD40. Functional analyses reveal that (1) bulk-DC show less ability in endocytosis than conventional-GM DC and are comparable in IL-12 p70 production with conventional-GM and -GM/4 DC. (2) Bulk-DC exhibit stronger stimulatory capacity in allogeneic T-cell proliferation than conventional DC. (3) By using ovalbumin (OVA) and OVA-specific T-cell receptor (TCR) transgenic mice (DO11.10) system, OVA protein-loaded bulk-DC stimulated CD4 T cells of DO11.10 mice more than conventional-GM DC and comparable with conventional-GM/4 DC. (4) Furthermore, OVA peptide-pulsed bulk-DC stimulated CD4 T cells more than conventional-GM and -GM/4 DC. These data indicate that bulk-DC are functionally more mature than conventional DC. Taken together, bulk-culture method is a simple technique for generating functionally mature BM-DC in large quantities and high purity.

Dendritic cells pulsed with apoptotic squamous cell carcinoma have anti-tumor effects when combined with interleukin-2.

Objectives Dendritic cells, the most potent of the antigen‐presenting cells, have been widely studied as a promising tool for antitumor immunotherapies. However, little has been determined about the efficacy of dendritic cell–based therapy for the treatment of squamous cell carcinoma (SCC) because there are no known SCC‐specific antigens. Recent reports indicate that dendritic cells can acquire antigens in the form of apoptotic cells and induce cytotoxic T‐lymphocyte responses. The aim of this study was to test the feasibility of adoptive dendritic cell immunotherapy against SCC by using apoptotic tumor cells as a source of tumor antigens.

Combined treatment with interleukin-18 and low-dose interleukin-2 induced regression of a murine sarcoma and memory response.

Among cytokines applied for immunotherapy of cancer, one of the most successful approaches to date involves systemic delivery of high-dose interleukin (IL)-2. However, the clinical utility of high-dose IL-2 has been limited by significant adverse effects, including vascular leak syndrome. Given this limitation, many attempts to decrease the dosage of IL-2 while maintaining its antitumor therapeutic effects are being made. In this study, the authors observed that combined use of IL-18 and low-dose IL-2 synergistically promoted in vitro proliferation of natural killer cells with up-regulation of IL-2 receptor-&agr; and also synergistically stimulated cytolytic activity and interferon-&ggr; production by these cells. Furthermore, intratumoral injections of these two cytokines completely eradicated day-12 established subcutaneous tumor and induced CD4+-dependent memory in a MCA205 murine tumor model. Observed primary antitumor responses depended largely on natural killer cells and partly on CD8+ T cells. Fas-L pathway and interferon-&ggr; production were critical in tumor eradication. These results indicate that combined administration of IL-18 and low-dose IL-2 could be a new model for cancer immunotherapy, which probably engages the activation of natural killer cells through interferon-&ggr;– and Fas-L–dependent pathways.

Dendritic cells promote T-cell survival or death depending upon their maturation state and presentation of antigen.

Introduction: The presence of an ineffective immune response to cancer has been widely recognized. Although we and others have used a variety of strategies to augment anti-tumor immune responses’4, even with the relatively recent identification of melanoma antigens, and the subsequent generation of antigen specific T-cells6, clinical responses in this disease remain limited. The limited in vivo success of immunotherapy for cancer may be due to the premature death of immune effector cells caused by factors in the tumor microenvironment. Tumors cause DC dysfi~nction’-~, DC apoptosis lo”l, and signaling defects ‘‘I3 in immune effectors including loss of CD3 c-chain in Tcells. CTL capable of recognizing and eliminating tumor targets are also preferentially susceptible to an activation induced cell death (AICD)“ following antigen engagement of the Tcell receptor. Although DCs play a critical role in the induction of antigen specific immune responses by presenting antigens and co-stirnulatory signal(s)I6 to naive and memory T-cells, DCs can also induce a state of specific immune t~lerance””~ through the induction of Tcell anergy andor apoptotic death. Tolerogenic DCs within the tumor may also allow their escape from immune effector cell^^^^. DC function depends in part on its state of maturation. DC induction of immune activation or tolerance may represent a direct consequence of their maturational state. 15

Genetic Alterations and Their Clinical Implications in High-Recurrence Risk Papillary Thyroid Cancer

Purposen Papillary thyroid carcinomas (PTCs) frequently involve genetic alterations. The objective of this study was to investigate genetic alterations and further explore the relationships between these genetic alterations and clinicopathological characteristics in a high-recurrence risk (node positive, N1) PTC group. Materials and Methodsn Tumor tissue blocks were obtained from 240 surgically resected patients with histologically confirmed stage III/IV (pT3/4 or N1) PTCs. We screened gene fusions using NanoString’s nCounter technology and mutational analysis was performed by direct DNA sequencing. Data describing the clinicopathological characteristics and clinical courses were retrospectively collected. Resultsn Of the 240 PTC patients, 207 (86.3%) had at least one genetic alteration, including BRAF mutation in 190 patients (79.2%), PIK3CA mutation in 25 patients (10.4%), NTRK1/3 fusion in six patients (2.5%), and RET fusion in 24 patients (10.0%). Concomitant presence of more than two genetic alterations was seen in 36 patients (15%). PTCs harboring BRAF mutation were associated with RET wild-type expression (p=0.001). RET fusion genes have been found to occur with significantly higher frequency in N1b stage patients (p=0.003) or groups of patients aged 45 years or older (p=0.031); however, no significant correlation was found between other genetic alterations. There was no trend toward favorable recurrence-free survival or overall survival among patients lacking genetic alterations. Conclusionn In the selected high-recurrence risk PTC group, most patients had more than one genetic alteration. However, these known alterations could not entirely account for clinicopathological features of high-recurrence risk PTC.