Tomoya Hirosawa

Zoledronate sensitizes neuroblastoma-derived tumor-initiating cells to cytolysis mediated by human γδ T cells.

Neuroblastoma is the most common extracranial solid tumor in children that is refractory to intensive multimodal therapy. In particular, tumor-initiating cells (TICs) derived from neuroblastoma are believed responsible for tumor formation and resistance to the conventional therapy; an optimal strategy therefore should target this population. Technically, TICs can be enriched from neuroblastoma-derived spheres when the tumor cells are cultured in a serum-free medium supplemented with certain growth factors. Recently, a line of evidence has suggested antitumor potential of V&ggr;9V&dgr;2 T cells (&ggr;&dgr; T cells), a T-cell population that recognizes and kills target cells independent of surface HLA expressions. Furthermore, a mevalonate pathway inhibitor, zoledronate, has been reported to enhance cytolytic activity of &ggr;&dgr; T cells. On the basis of these findings, we hypothesized that zoledronate would sensitize neuroblastoma TICs to &ggr;&dgr; T-cell–mediated cytolysis and promote therapeutic efficacy against neuroblastoma. In the current study, we show that zoledronate efficiently sensitizes both neuroblastoma-derived adherent cells and sphere-forming cells to &ggr;&dgr; T-cell–mediated cytolysis. Subsequently, in vitro colony formation inhibition assay and in vivo animal studies reveal that the presence of &ggr;&dgr; T cells decelerates outgrowth of neuroblastoma TICs. We finally show that addition of interleukin-15 and/or interleukin-18 in culture enhances the cytolytic activity of &ggr;&dgr; T cells. On the basis of these data, we conclude that ex vivo expanded &ggr;&dgr; T cells are a promising tool for antineuroblastoma immunotherapy with options for further improvement.

Glypican‐3 could be an effective target for immunotherapy combined with chemotherapy against ovarian clear cell carcinoma

Glypican‐3 (GPC3) is useful not only as a novel tumor marker, but also as an oncofetal antigen for immunotherapy. We recently established HLA‐A2‐restricted GPC3144‐152 peptide‐specific CTL clones from hepatocellular carcinoma patients after GPC3144‐152 peptide vaccination. The present study was designed to evaluate the tumor reactivity of a HLA‐A2‐restricted GPC3144‐152 peptide‐specific CTL clone against ovarian clear cell carcinoma (CCC) cell lines. The GPC3144‐152 peptide‐specific CTL clone could recognize HLA‐A2‐positive and GPC3‐positive ovarian CCC cell lines on interferon (IFN)‐γ enzyme‐linked immunospot assay and showed cytotoxicity against KOC‐7c cells. The CTL clone recognized naturally processed GPC3‐derived peptide on ovarian CCC cells in a HLA class I‐restricted manner. Moreover, we confirmed that the level of GPC3 expression was responsible for CTL recognition and that subtoxic‐dose chemotherapy made tumor cells more susceptible to the cytotoxic effect of CTL. Thus, it might be possible to treat ovarian CCC patients by combining chemotherapy with immunotherapy. Our data suggest that GPC3 could be an effective target for immunotherapy against ovarian CCC. (Cancer Sci 2011; 102: 1622–1629)

Diagnostic utility of CD117, CD133, SALL4, OCT4, TCL1 and glypican-3 in malignant germ cell tumors of the ovary

Aim:  Primary ovarian malignant germ cell tumors (OMGCTs) are rare and difficult to diagnose. Immunohistochemistry can help in the diagnosis and development of new management strategies. The aim of this study was to investigate the frequency of CD117, CD133, SALL4, OCT4, TCL1 and glypican‐3 marker expression in OMGCTs.

Knowledge and practice of universal precautions among health care workers in four national hospitals in Kabul, Afghanistan

INTRODUCTION This study aimed to assess the knowledge and practice of health care workers (HCWs) towards universal precautions (UPs) and to look into any associations between knowledge and practice. METHODOLOGY A cross-sectional study was undertaken between August and October 2012, involving 300 HCWs from four national public hospitals in Kabul, Afghanistan. A self-administered questionnaire assessing the knowledge and practice of UPs was used. RESULTS Among the 300 respondents, the mean knowledge score was 5.2 with a standard deviation (SD) of 1.5. On the practice score, the mean was 8.7 (SD = 2.2). A total of 90.6% and 70.8% of HCWs believed that UPs were necessary in contact with urine/feces and tears, respectively, although UPs are not necessary in these cases. On the other hand, 57.8% reported that they always recapped the needle after giving an injection, and 31.8% did not always change gloves in between patients. There were no associations between the knowledge and self-reported practice of UPs. CONCLUSIONS The HCWs in Kabul had inadequate knowledge and poor practice of UPs. Training for HCWs is needed to encourage them to adhere to practice based on improved knowledge.

Smoking and associated factors among the population aged 40-64 in Shahroud, Iran.

BACKGROUND Smoking is known as a major risk factor for different types of cancer, as well as cardiovascular disease. Its prevalence is increasing in developing countries. The aims of this study were to determine the prevalence of smoking and its associated factors among the population aged 40-64 years in the city of Shahroud which is a representative urban population in Iran. MATERIALS AND METHODS A cross-sectional population-based study with stratified random cluster sampling was conducted in 2009 as the first phase of Shahroud Eye Cohort Study. Of 6,311 people, 5,190 participated (82.2%). Information about smoking habit was obtained by face-to- face interview. RESULTS The overall prevalence of current tobacco smoking was 11.3% (95%CI: 10.5-12.3). It was significantly higher among males than females (25.7% and 0.71%, P<0.001). The prevalence of current cigarette smoking was 10.8% and 1.75% were past smokers. The smoking rate of water-pipe was 0.67%. Unemployed people smoked more than employed (OR=2.66, 95%CI: 1.38-5.14). CONCLUSIONS The prevalence of smoking is low in Shahroud compared with other parts of Iran and other countries. Age, sex, job and marital status were associated with smoking. The low smoking rate among women may be attributed to cultural and social reasons.

Evaluation of Knowledge, Practices, and Possible Barriers among Healthcare Providers regarding Medical Waste Management in Dhaka, Bangladesh

Background Improper handling of medical wastes, which is common in Bangladesh, could adversely affect the hospital environment and community at large, and poses a serious threat to public health. We aimed to assess the knowledge and practices regarding medical waste management (MWM) among healthcare providers (HCPs) and to identify possible barriers related to it. Material/Methods A cross-sectional study was carried out during June to September, 2012 including 1 tertiary, 3 secondary, and 3 primary level hospitals in Dhaka division, Bangladesh through 2-stage cluster sampling. Data were collected from 625 HCPs, including 245 medical doctors, 220 nurses, 44 technologists, and 116 cleaning staff who were directly involved in MWM using a self-administered (researcher-administered for cleaning staff), semi-structured questionnaire. Results Nearly one-third of medical doctors and nurses and two-thirds of technologists and cleaning staff had inadequate knowledge, and about half of medical doctors (44.0%) and cleaning staff (56.0%) had poor practices. HCPs without prior training on MWM were more likely to have poor practices compared to those who had training. Lack of personal protective equipment, equipment for final disposal, MWM-related staff, proper policy/guideline, and lack of incinerator were identified as the top 5 barriers. Conclusions Strengthening and expansion of ongoing educational programs/training is necessary to improve knowledge and practices regarding MWM. The government should take necessary steps and provide financial support to eliminate the possible barriers related to proper MWM.

An HLA-modified ovarian cancer cell line induced CTL responses specific to an epitope derived from claudin-1 presented by HLA-A*24:02 molecules

In an attempt to induce cytotoxic T lymphocytes (CTLs) that react to ovarian cancer cells, we isolated a CTL clone that specifically recognizes claudin-1 in an HLA-A*24:02-restricted manner. Naïve CD8(+) T lymphocytes were obtained from a healthy adult donor and stimulated twice in vitro with HLA-modified TOV21G cells that were originally derived from an ovarian clear-cell carcinoma line. The TOV21G modification involved RNAi-mediated gene silencing of intrinsic HLA molecules and lentiviral transduction of a synonymously mutated HLA-A*24:02. Then, cDNA library construction using mRNA extracted from the parental TOV21G cells and subsequent expression cloning were conducted. These experiments revealed that a CTL clone obtained from the bulk culture recognized a minimal epitope peptide RYEFGQALF, which was derived from an autoantigen claudin-1 presented by HLA-A*24:02 molecules. This clone exhibited cytolytic activities against three ovarian cancer cell lines and normal bronchial epithelial cells in an HLA-A*24:02-restricted manner. Our data indicate that HLA-modified cancer cells can be used as an artificial antigen-presenting cell to generate antigen-specific CTLs in a manner restricted by an HLA allele of interest.

Mismatched human leukocyte antigen class II-restricted CD8^+ cytotoxic T cells may mediate selective graft-versus-leukemia effects following allogeneic hematopoietic cell transplantation

Partial human leukocyte antigen (HLA)‐mismatched hematopoietic stem cell transplantation (HSCT) is often performed when an HLA‐matched donor is not available. In these cases, CD8+ or CD4+ T cell responses are induced depending on the mismatched HLA class I or II allele(s). Herein, we report on an HLA‐DRB1*08:03‐restricted CD8+ CTL clone, named CTL‐1H8, isolated from a patient following an HLA‐DR‐mismatched HSCT from his brother. Lysis of a patient Epstein–Barr virus‐transformed B cell line (B‐LCL) by CTL‐1H8 was inhibited after the addition of blocking antibodies against HLA‐DR and CD8, whereas antibodies against pan‐HLA class I or CD4 had no effect. The 1H8‐CTL clone did not lyse the recipient dermal fibroblasts whose HLA‐DRB1*08:03 expression was upregulated after 1 week cytokine treatment. Engraftment of HLA‐DRB1*08:03‐positive primary leukemic stem cells in non‐obese diabetic/severe combined immunodeficient/γc‐null (NOG) mice was completely inhibited by the in vitro preincubation of cells with CTL‐1H8, suggesting that HLA‐DRB1*08:03 is expressed on leukemic stem cells. Finally, analysis of the precursor frequency of CD8+ CTL specific for recipient antigens in post‐HSCT peripheral blood T cells revealed a significant fraction of the total donor CTL responses towards the individual mismatched HLA‐DR antigen in two patients. These findings underscore unexpectedly significant CD8 T cell responses in the context of HLA class II. (Cancer Sci 2011; 102: 1281–1286)

Characteristics of Liver Cancer at Khmer-Soviet Friendship Hospital in Phnom Penh, Cambodia

BACKGROUND Hepatocellular carcinoma (HCC) is one of the most frequent cancers in South East Asian countries including Cambodia, where prevalence of chronic carriers of hepatitis B and C virus (HBV and HCV) is reported to be very high. We reviewed HCC cases admitted to a cancer hospital in Phnom Penh, which is the only one hospital for cancer treatment and care in Cambodia during the study period. MATERIALS AND METHODS Information was collected from medical records of 281 cases (210 males and 71 females) diagnosed as primary HCC from 2006 to 2011. RESULTS The subjects were 7-81 years old with a median age of 53 years. Hypochondriac pain was the most common complained symptom (74%). One third of the cases presented with jaundice. Nearly half had ascites at their first visit. One third had liver cirrhosis. Nearly three fourths of the cases presented with tumor sized more than 50 mm in diameter, and in almost all cases (97.4%) the size was more than 20 mm. Among 209 subjects tested, hepatitis virus carriers were 75.6%; 46.4% for HBV only, 21.5% for HCV only, and 7.7% for both viral infections. Median age of patients with HBV was about ten years younger than those with HCV. CONCLUSIONS This study revealed the characteristics of HCC cases in Cambodia, although there were several limitations. Most HCC cases were infected with HBV and/or HCV, and diagnosed at late stages with complications. This implicated that public health intervention to prevent HBV and HCV infection is of high priority.