Researchers have discovered the cell type that gives rise to rhabdomyosarcoma, the most prevalent soft tissue cancer in children, according to a new study published on January 8, 2018.
Researchers at St. Jude Children’s Research Hospital oncologists discovered that cancer arises from immature progenitors that would normally develop into cells lining blood vessels.
“We are still using the same chemotherapy that was in use 46 years ago, with the same outcomes. A better understanding of the machinery of rhabdomyosarcoma could enable entirely new treatment approaches.” said Hatley, lead author of the study.
“While these tumors appear to be muscle cells under the microscope, and clinicians had thought that they arose from muscle progenitor cells, that didn’t explain why the tumors can occur in tissues that don’t have skeletal muscle, like bladder, prostate and liver,” he continued.
The researchers had genetically engineered a mouse to have a biological switch that enabled researchers to selectively turn on a key piece of cellular machinery called the Hedgehog pathway. Abnormal activation of this pathway was known to trigger cancers. However, the animals developed head and neck tumors.
“These tumors were not driven by muscle cells at all, so we decided to zero in on the biological machinery to find the cell of origin in these mouse tumors,” Hatley said.
His experiments revealed the cells that became rhabdomyosarcoma were not muscle cells, but were immature cells that would mature into cells lining the inner surface of blood vessels. The blood vessels occupy the space between muscle fibers.
The finding suggested the cancer process began before birth. “Indeed, when we studied the mice at the embryonic stage, we saw the cells between the muscle fibers expanded explosively and formed tumors early in development,” Hatley said.
The discovery that rhabdomyosarcoma is not really a muscle cancer, which may help researchers not to jump to assumptions about the origins of tumors based on their appearance under the microscope or the genes that are turned on. This discovery can guide us to new treatment strategies.
Growing incidence of cancer around the globe is increasing the demand for targeted cancer therapy measures, as per Targeted Cancer Therapies Market report published by Coherent Market Insights.