Bone marrow¹ transplantation with genetically² modified cells may prolong the period of cancer-free survival, suggests a study led by Dr. Vivek Rangnekar, associate director of translational research for the Markey Cancer Center at the University of Kentucky. Bone marrow, a spongy（海绵状的） tissue inside bones, contains stem cells that produce blood cells, including leukocytes（白血球） , erythrocytes（红细胞） and platelets（血小板） . In the cover story of the July issue of Cancer Biology & Therapy, Rangnekar and his team explore the transfer of bone marrow from Par-4/SAC-transgenic donor³ mice to control mice as a means of transferring anti-cancer potential.

Par-4 (also known as PAWR) is a tumor⁵ suppressor protein that selectively induces apoptosis（细胞死亡） in cancer cells, but not normal cells. This function of Par-4 is mediated⁶ by its central core domain⁷, SAC. SAC-transgenic mice are resistant⁸ to the growth of spontaneous and inducible⁹（可诱导的） tumors.

After transplantation, the researchers discovered the expression of cancer-killer¹⁰ SAC-GFP activity in bone marrow cells of the recipient¹¹ mice, implying the successful transfer and colonization¹² of the anti-cancer tissue from the donors¹³. In addition, soluble¹⁴ Par-4 or SAC protein injected into mice inhibited¹⁵ the growth of metastatic tumors.

Rangnekar, the Alfred Cohen Endowed Chair of Oncology Research at Markey, says the study shows promise for treating both primary and metastatic tumors.

"We are excited by the findings of this study as they indicate that secreted¹⁷ Par-4 is systemically active in mice," Rangnekar said. "Optimization¹⁸ of the bone marrow transplantation procedure using stem cells that are genetically modified to systemically secrete¹⁶ potent⁴ protein payloads of Par-4/SAC killer activity may offer a new approach to treat not only primary tumors but also metastatic tumors of diverse（不同的） origin."