P-002 - The therapeutic effect of irreversible electroporation according to tissue properties of upper gastrointestinal tract: feasibility study for esophag...

Date 04 July 2015
Event WorldGI 2015
Session Posters
Topics Oesophageal Cancer
Surgery and/or Radiotherapy of Cancer
Presenter H.S. Choi
Citation Annals of Oncology (2015) 26 (suppl_4): 1-100. 10.1093/annonc/mdv233
Authors H.S. Choi1, H.J. Chun1, I.K. Yoo1, J.M. Lee1, S.H. Kim1, E.S. Kim1, B. Keum1, Y.T. Jeen2, H.S. Lee1, C.D. Kim1
  • 1Korea University College of Medicine, Seoul/KR
  • 2Department of Internal Medicine, Seoul/KR

Abstract

Introduction

Irreversible electroporation (IRE) is a promising novel technique for the ablation of tumors. IRE has an advantage over other ablation technique in its mechanism to remove undesired cells by affecting the cell membrane without thermally destructing blood vessels, nerves and the surrounding tissues. This therapeutic modality has been considered to apply to Barrett's dysplasia or epithelial neoplasm of upper gastrointestinal tract instead of previous radiofrequency ablation. Recently, we have validated the effectiveness of IRE tissue ablation on stomach, but there was no study about treatment effect of IRE according to tissue property in upper gastrointestinal tract. Our purpose was to study effectiveness of IRE according to tissue properties in rat stomach.

Methods

The Sprague-Dawley rats were used throughout this study. IRE ablation was applied in upper stomach (squamous cell epithelium) and lower stomach (columnar cell epithelium) with same energy parameters. The energy delivered for each ablation was 50/100 pulses of 1KV/cm ∼ 3KV/cm. All samples for histologic analysis and tunnel assay were got at 0hrs, 10hrs, 24hrs and 72hrs after IRE. And we used DNA microarrays to measure the expression levels of large numbers of genes in rat stomach according to different electrical energy. And we measured several apoptotic gene expression levels using real time RT-PCR.

Results

All animals survived for their designated times. H-E staining showed extensive cell death area, which were proved by a pyknotic nucleus and eosinophilic cytoplasm near absence of cell at 10 hours after IRE ablation in upper (squamous cell epithelium) and lower (columnar cell epithelium) gastric tissue. We confirmed apoptotic cell death by Tunnel assay. The number of significantly up-regulated apoptotic genes was higher in 2KV, 100 pulse and 10hr than that of other electrical energy groups. The significantly up-regulated genes related to apoptosis after IRE ablation in all IRE setting were s100a8/9, Ccl2, Timp1, Aif1, Lcn2, and hspb1 genes, but caspase-related genes were down regulated in all conditions.

Conclusion

This study showed that IRE ablated stomach tissue through cellular apoptosis. And the degree of apoptosis after IRE ablation was tissue and electric energy specific in gastrointestinal tract. This study suggests the potentiality of IRE application in the treatment of not only gastric neoplasm but also esophageal neoplasm including dysplasia of Barrett's esophagus without metastasis.