Cloning of carrier cells infected with oncolytic adenovirus driven by midkine promoter and biosafety studies.

BACKGROUND: A549 carrier cells infected with oncolytic adenovirus can induce complete tumor reduction of subcutaneous ovarian tumors but not intraperitoneal disseminated ovarian tumors. This appears to be a result of the insufficient antitumor effect of A549 carrier cells. Therefore, in the present study, we cloned a novel carrier cell with the aim of improving the antitumor effects. METHODS: Carrier cells infected with oncolytic adenovirus AdE3-midkine with a midkine promoter were cloned by limiting dilution. We examined the antitumor effects of these cells on subcutaneous and intraperitoneal OVHM ovarian tumors in a syngeneic mouse model. Biosafety tests were conducted in beagle dogs and rabbits. RESULTS: We cloned EHMK-51-35 carrier cells with 10-fold higher antitumor effects compared to A549 carrier cells in vitro. EHMK-51-35 carrier cells co-infected with AdE3-midkine and Ad-mGM-CSF induced a 100% complete tumor reduction in subcutaneous tumors and a 60% reduction of intraperitoneal disseminated tumors. Single-dose acute toxicity test on beagle dogs with EHMK-51-35 carrier cells co-infected with AdE3-midkine and Ad-cGM-CSF showed no serious side effects. Biologically active adenoviruses were not detected in the blood, saliva, feces, urine or whole organs. In a chronic toxicity test, VX2 tumors in rabbits were injected five times with EHMK-51-35 carrier cells infected with AdE3-midkine and these rabbits showed no serious side effects. CONCLUSIONS: Significant antitumor effects and safety of cloned EHMK-51-35 carrier cells were confirmed in intraperitoneal ovarian tumors and toxicity tests, respectively. These findings will be extended to preclinical efficacy studies using dogs and cats, with the aim of conducting human clinical trials on refractory solid tumors.

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.