S1P1 essential for tumor growth and is blocked by RNA interference

Requirement for sphingosine 1–phosphate receptor-1 in tumor angiogenesis demonstrated by in vivo RNA interference

Tumor growth and metastasis require new blood ves-sel growth, a process called angiogenesis. There are many factors involved in the nor-mal growth and stabilization of new blood vessels. One of these, sphingosine 1-phosphate receptor 1 (S1P1), is required during embryonic development to stabilize new blood vessels. Timothy Hla and colleagues, from the University of Connecticut Health Science Center, inves-tigated the importance of S1P1 in angiogenesis in tumors. The authors implanted mice with Lewis lung carcinoma cells and examined tissue sections for S1P1 expression. S1P1 expression was found in the blood vessels only in the areas around the implanted tumor.

The researchers then developed an RNA interference technique, a method that specifically blocks S1P1 expression. They showed that using RNA interference they successfully blocked S1P1 expression in cell culture and that when they injec-tion of the S1P1-specific interfering RNA into tumors in mice, these also showed repressed S1P1 expres-sion. In conjunction with loss of S1P1 expression, new blood vessel stabilization and growth were compromised and tumor growth suppressed in vivo. This study indicates both that S1P1 is vital for blood vessel growth in tumors and that RNA interference technology may be of great use in anticancer therapies.

Title: Requirement for sphingosine 1–phosphate receptor-1 in tumor angiogenesis demonstrated by in vivo RNA interference

Author Contact:
Timothy Hla
University of Connecticut Health Center, Farmington, CT 06030, USA
Phone: (860) 679-4128; Fax: (860) 679-1201; E-mail: hla@nso2.uchc.edu