Scientists in the OHSU School of Medicine found that transplanted cells derived from adult bone marrow can fuse with intestinal stem cells of both normal and diseased tissue comprising the cellular lining of intestinal walls, known as the epithelium. The findings, reported recently in the Proceedings of the National Academy of Sciences, point to the integral role of bone marrow-derived cells in not only regeneration of damaged tissue, but also disease progression.
"It's the first observation that there's fusion at the level of stem cells," said the study's corresponding author, Melissa Wong, Ph.D., assistant professor of dermatology, and cell and developmental biology. "Second, we're seeing cell fusion in tumors and we believe that this concept is an underappreciated mechanism for promoting tumor growth. Our findings have implications on how tissues regenerate and how, in the process of this regeneration, cells may become prone to future problems. "
Although the tumor in her study did not "initiate" tumors or become malignant, Wong believes the fusion process is one explanation for how tumors acquire genetic instability and have the potential to give rise to malignant cancer.
One promising result could be in better understanding the careful balance between rapid and effective regeneration after tissue injury, and minimizing the risk of cancer. This balance can be examined in mouse models of inflammatory bowel disease, where, like humans, epithelial damage and chronic tissue repair occurs.
"Ten percent of patients with inflammatory bowel disease go on to get colorectal cancer," Wong said. "We think that the bone marrow cells aid in repair of the epithelium, but the cell fusion hybrids that remain are generally unstable. Fusion ma
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Contact: Jonathan Modie
modiej@ohsu.edu
503-494-8231
Oregon Health & Science University
9-May-2006