Kazuko Takagi

Assessment of laparoscopic training for gynecological malignancies using Thiel‑embalmed human cadavers

The introduction of laparoscopic surgery has also been beneficial for patients with gynecological malignancies. In this respect, surgeons should receive related training in the context of human resource development. Hands-on training was introduced using Thiel-embalmed human cadavers (THCs) in 2014. To determine the usefulness of THCs, they were evaluated in terms of tissue color, consistency and operative tactility, among others, compared with in vivo laparoscopic training for gynecological malignancies. Hands-on training sessions using THCs were held for a total of 11 times at Ehime University Graduate School of Medicine between March 2014 and October 2017. Training on THCs included advanced laparoscopic procedures for radical hysterectomy type III. At the end of each training session, data were collected using a standardized, anonymous questionnaire termed the Likert scale. THCs ensured flexibility and plasticity of tissues and organs; therefore, the working space was similar to that in the living body under pneumoperitoneum. After analyzing the quality and consistency of tissue and organ color compared with in vivo conditions, most of the participants agreed or strongly agreed regarding the uterus, adnexa and ureter, but not regarding the large blood vessels. The highest scores were observed in the authenticity of the anatomical condition of each organ. Most participants strongly agreed that training using THCs would help improve their laparoscopic skills with a high level of satisfaction. Furthermore, most participants reported that they would recommend this training to other obstetrician-gynecologists. Laparoscopic training for gynecological malignancies using THCs was comparable to the in vivo conditions in terms of surgical view and operative tactility. Therefore, THCs may be an excellent training tool for improving laparoscopic surgical skills for gynecological malignancies.

420. Improvement of Antitumor Activity in Intraperitoneal Ovarian Cancer Model by a Noble Cloned Carrier Cell Infected with Oncolytic Adenovirus

Infection inhibition of virus by antiviral antibodies is one of the major problems that cancer gene therapy has never shown the significant antitumor activity in human clinical trial. Oncolytic adenovirus-infected A549 carrier cells develop cell fragments and exosomes containing oncolytic adenoviral particles and could infect target cancer cells by overcoming antiadenoviral immunogenicity. A549 carrier cells induce complete tumor reduction in syngeneic subcutaneous mouse tumor model by direct antitumor activity of oncolytic adenovirus, antiadenoviral cytotoxic T lymphocyte and antitumor immunity but not in syngeneic intraperitoneal ovarian cancer mouse model. In this study, we cloned and established a noble carrier cell by limiting dilution to induce the complete tumor reduction of the intraperitoneal ovarian tumor by increasing antitumor activity of carrier cells. Oncolytic adenovirus AdE3-midkine driven by midkine promoter and non-replicative adenovirus Ad-mGM-CSF were used in this study. We cloned a nobel carrier cell from EHMK adenocarcinoma cells by limiting dilution, which were established in our laboratory. EHMK cells were infected with AdE3-midkine and co-cultured with ovarian adenocarcinoma HEY cells with or without antiadenoviral antibodies. In vitro antitumor activity of cloned EHMK carrier cells was calculated by IC50 and compared with that of A549 carrier cells infected with AdE3-midkine. B6C3F1 mouse and cognate ovarian cancer OVHM cell line were used in this study. Mice were injected intraperitoneally with OVHM cells after immunization with adenovirus and treated by carrier cells infected with AdE-midkine with or without Ad-mGM-CSF. Antitumor activity of carrier cells was analyzed by Kaplan Meier survival curve. In vitro antitumor activity of EHMK carrier cells was 1.0±0.1 and 1.1±0.2 that of A549 carrier cells with or without antiadenoviral antibodies, respectively. In vitro antitumor activity of EHMK-51 carrier cells after limiting dilution of EHMK cells was 4.5±1.1 and 3.4±1.9 that of A549 carrier cells with or without antiadenoviral antibodies, respectively. EMHK-51 cells were further cloned by limiting dilution. In vitro antitumor activity of EHMK-51-35 carrier cells was 3.1±1.5 and 2.8±0.9 that of EHMK-51 carrier cells with or without antiadenoviral antibodies, respectively. In comparison with A549 carrier cells, in vitro antitumor activity of EHMK-51-35 carrier cells was 12.5±4.3 and 10.5±5.0 that of A549 carrier cells with or without antiadenoviral antibodies, respectively. In mouse intraperitoneal tumor model, A549 carrier cells infected with AdE3-midkine ± Ad-mGM-CSF did not show any antitumor effect but EHMK carrier cells infected with AdE3-midkine with or without Ad-mGM-CSF showed 40% and 70% complete tumor reduction, respectively. From these results, it is concluded that EHMK-51-35 carrier cells might be potent to treat intraperitoneally metastasized ovarian cancer

437. Biosafety After the Injection of Carrier Cells Infected With Oncolytic Adenovirus

Although replication-competent viruses have been developed to treat cancers, their cytotoxic effects are insufficient, since infection with them is inhibited by generation of neutralizing antibodies. To address this limitation, we developed a carrier cell system to deliver a replication-competent adenovirus. Carrier cells infected with oncolytic adenovirus were injected into syngeneic subcutaneous ovarian tumors after immunization with adenovirus and induced complete tumor regression by the induction of antiadenoviral and antitumoral CTL responses. To start clinical trial, toxicity and biodistribution study were carried out in nude mice, rabbits and beagle dogs. Acute toxicity and distribution test were carried out after the single injection of carrier cells into ovarian tumor in nude mice. Chronic toxicity test was carried out by 8 injections of carrier cells into rabbits for 4 weeks. Excretion study was carried out to determine whether oncolytic adenovirus was excreted from the beagle dogs after the single injection of carrier cells. Acute toxicity test did not show any lethal side effects in nude mice. In biodistribution test, single injection of carrier cells into ovarian tumor induced the peak levels of oncolytic adenovirus the next day but did not show any significant levels of that in nude mice 14 days after injection. In chronic toxicity test, 8 injections of 1.25×107 cells/kg or less did not show any significant toxicity in rabbits. In excretion test, oncolytic adenovirus was not excreted into the urine and the stool of beagle dogs. This oncolytic adenovirus-infected carrier cell system might prove effective and safe in the preclinical efficacy and the biosafety test, respectively. Clinical trial is being scheduled to treat recurrent solid cancers.