Dr. Fukamachi from Japan stays in AMC, Korea: Part7

A3 Foresight Program: Collaborative Research on the Role of Epigenetic Pathway in Gastric Carcinogenesis

Report of a visit to AMC in Korea (May 14 to May 26, 2012)

HIROSHI FUKAMACHI (Department of Molecular Oncology, Tokyo Medical and Dental University)

Host researcher

Prof. Se Jin Jang (Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine)

Summary

I visited again Prof. Se Jin Jang’s laboratory (Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul) in Korea to culture tumor cells obtained from newly-dissected gastric cancers in a serum-free condition to examine whether these cells formed spheres, which have been considered to be a characteristic of stem cells. Preliminary results using gastric tumor xenografts suggest that there is a close relationship between tumorigenicity and sphere-formation. We hope that we can soon explore the mechanism of gastric tumorigenesis by using these sphere-forming cells in vitro. I deeply thank Prof. Se Jin Jang, Dr. Hyang Sook Seol and other members of AMC for giving me a chance to do experiment in a wonderful institute.


Contents

1. Background

As described in my previous report (“Dr. Fukamachi from Japan stays in AMC, Korea: Part 6”), we have been trying to identify and characterize human gastric tumor-initiating cells. In my previous visit to AMC, I tried to cultivate FACS-sorted tumor cells in a serum-free condition to examine whether cells obtained from newly-dissected gastric tumors formed spheres in vitro, and whether these sphere-forming cells were tumorigenic or not. We, however, could not obtain conclusive results, partly because number of samples used for experiments was small. Thus, I visited again AMC to do more work on this subject, in collaboration with researchers in AMC including Professor Jang and Dr. Seol.

2. The experiment in AMC

We tried to cultivate MACS-sorted tumor cells, partly because FACS machine was not fully working in AMC. We found some tumor cells formed spheres in vitro, and their tumorigenicity is now under investigation by subcutaneously injecting them into NOD-Scid mice. I also attended an international seminar hosted by Dana-Faber Cancer Institute in Boston, USA and AMC for Cancer Genome Discovery. It was an interesting seminar because both epigenetic and genetic changes play important roles in the carcinogenesis.

3. Discussion at SNU

During my stay in AMC, I visited Professor Woo Ho Kim, Department of Pathology, Seoul National University College of Medicine, to discuss how to collaborate with him on the characterization of markers on gastric epithelial cells, using tissue array system developed by him. It was a good chance for me to see latest pathological systems including a whole slide imaging system. Collaboration with Professor Kim will give us better understanding on the function of the markers.

4. Acknowledgments

I deeply thank Professor Jang and members of his laboratory including Dr. Seol for their help and kindness during my stay in AMC.