Tuesday, July 7, 2009
TUESDAY, July 7 (HealthDay News) -- Prosaposin, a protein secreted by non-metastatic tumors, inhibits metastasis by producing factors that inhibit angiogenesis, and may be a potential cancer treatment, according to a study published online July 6 in the Proceedings of the National Academy of Sciences.
Soo-Young Kang, Ph.D., of Children's Hospital Boston, and colleagues injected mice with highly metastatic tumor cells that contained additional prosaposin. They also injected mice with tumor cells followed by a direct injection of prosaposin.
In the first experiment, the researchers found that additional prosaposin reduced lung metastases by 80 percent and almost eliminated lymph node metastases. In the second experiment, they found that the tumor cells formed few or no lung metastases, and that prosaposin-treated mice lived 30 percent longer than untreated mice. They demonstrated that prosaposin stimulated production of tumor suppressor p53, which in turn stimulated production of thrombospondin-1.
"Further studies into the mechanism of prosaposin stimulation of stromal p53 and thrombospondin-1 expression may provide therapeutic targets that could prevent the metastatic spread of human prostate and breast tumors," the authors conclude. "Based on our observations, we propose that activation of stromal p53 may also be a possible strategy to limit and perhaps cause regression of tumor growth and metastasis."
Diabetes & Endocrinology
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