Exosomes play important roles in cancer progression. Although its contents (e.g., proteins and microRNAs) have been focused on in cancer research, particularly as potential diagnostic markers, the exosome behavior and methods for exosome quantification remain unclear. In the present study, we analyzed the tumor-derived exosome behavior and assessed the quantification of exosomes in patient plasma as a biomarker for esophageal squamous cell carcinoma (ESCC). A CD63-GFP expressing human ESCC cell line (TE2-CD63-GFP) was made by transfection, and mouse subcutaneous tumor models were established. Fluorescence imaging was performed on tumors and plasma exosomes harvested from mice. GFP-positive small vesicles were confirmed in the plasma obtained from TE2-CD63-GFP tumor-bearing mice. Patient plasma was collected in Chiba University Hospital (n=86). Exosomes were extracted from 100 µl of the plasma and quantified by acetylcholinesterase (AChE) activity. The relationship between exosome quantification and the patient clinical characteristics was assessed. The quantification of exosomes isolated from the patient plasma revealed that esophageal cancer patients (n=66) expressed higher exosome levels than non-malignant patients (n=20) (P=0.0002). Although there was no correlation between the tumor progression and the exosome levels, exosome number was the independent prognostic marker and low levels of exosome predicted a poor prognosis (P=0.03). In conclusion, exosome levels may be useful as an independent prognostic factor for ESCC patients.
We examined the effect of the combination of herpes simplex virus type1-thymidine kinase (HSV-TK)-suicide gene therapy and interleukin-21 (IL-21) immune gene therapy.To improve tumor specificity and the safety of gene therapy, we designed the suicide gene (HSV-TK) to be driven by midkine (MK) minimal promoter (MKp-TK). Plasmid DNA containing HSV-TK-suicide gene or IL-21 gene was injected into TE2 and Colon26 tumors developed in nude mice and electric pulses were then delivered.Tumors transduced with the MKp-TK gene demonstrated increased sensitivity to ganciclovir (GCV) in vitro and in vivo. MK minimal promoter conferred efficient transcriptional activity to the HSV-TK-suicide gene and in vivo electroporation was an effective method for transducing the MKp-TK gene. IL-21-transduced tumors disappeared completely in syngeneic BALB/c mice. However, the tumors were not suppressed completely in T-cell-depleted nude mice, and antitumor effects were absent in NK-cell-depleted mice. These data suggest that IL-21 induces T- and NK-cell-dependent antitumor effects. Furthermore, the growth of IL-21-producing tumors subsequently transduced with MKp-TK by electroporation was significantly retarded compared with control groups.Using the minimal promoter region of MK to drive the HSV-TK gene and in vivo electroporation to transduce IL-21 DNA into the tumors produced an efficient gene therapy with improved safety. To our knowledge, this is the first report of a combination gene therapy using HSV-TK/GCVand IL-21.
In laparoscopic proximal gastrectomy(LPG)with esophago-gastro anastomosis, the key of obtaining good surgical view is how to exclude the stomach from the supra-pancreatic area.
Short gastric vessel division (SGVD) has been performed as a part of fundoplication for achalasia. However, whether or not SGVD is necessary is still unknown. Forty-six patients with achalasia who underwent a laparoscopic surgery with or without SGVD were analyzed. A questionnaire was administered to assess the postoperative improvement. Regarding improvement of dysphagia and postoperative reflux, there were no significant differences between SGVD (+) group and SGVD (-) group (P = 0.588 and P = 0.686, respectively). Nineteen patients (95%) in the SGVD (+) group and 24 (92%) in the SGVD (-) group answered that the surgery was satisfactory (P = 0.756). In the SGVD (+) group, the pre- and postsurgical body weight increase was +7.3%. In the SGVD (-) group, it was 8.2%. There was no significant difference of body weight increase between the 2 groups (P = 0.354). SGVD is not always required in laparoscopic surgery for achalasia.
To clarify the usefulness of arterial phase scans in contrast computed tomography (CT) imaging of strangulation ileus in order to make an early diagnosis.A comparative examination was carried out with respect to the CT value of the intestinal tract wall in each scanning phase, the CT value of the content in the intestinal tract, and the CT value of ascites fluid in the portal vein phase for a group in which ischemia was observed (Group I) and a group in which ischemia was not observed (Group N) based on the pathological findings or intra-surgical findings. Moreover, a comparative examination was carried out in Group I subjects for each scanning phase with respect to average differences in the CT values of the intestinal tract wall where ischemia was suspected and in the intestinal tract wall in non-ischemic areas.There were 15 subjects in Group I and 30 subjects in Group N. The CT value of the intestinal tract wall was 41.8 ± 11.2 Hounsfield Unit (HU) in Group I and 69.6 ± 18.4 HU in Group N in the arterial phase, with the CT value of the ischemic bowel wall being significantly lower in Group I. In the portal vein phase, the CT value of the ischemic bowel wall was 60.6 ± 14.6 HU in Group I and 80.7 ± 17.7 HU in Group N, with the CT value of the ischemic bowel wall being significantly lower in Group I; however, no significant differences were observed in the equilibrium phase. The CT value of the solution in the intestine was 18.6 ± 9.5 HU in Group I and 10.4 ± 5.1 HU in Group N, being significantly higher in Group I. No significant differences were observed in the CT value of the accumulation of ascites fluid. The average difference in the CT values between the ischemic bowel wall and the non-ischemic bowel wall for each subject in Group I was 33.7 ± 20.1 HU in the arterial phase, being significantly larger compared to the other two phases.This is a retrospective study using a small number of subjects; however, it suggests that there is a possibility that CT scanning in the arterial phase is useful for the early diagnosis of strangulation ileus.
