. . . . . . "investigational"@en . . . . "R115777"@en . "Tipifarnib"@en . . . . "192185-68-5"@en . . . . . . . "R115777 is a substance that is being studied in the treatment of acute myeloid leukemia (AML) and other types of cancer. It belongs to the family of drugs called farnesyltransferase inhibitors. It is also called tipifarnib and Zarnestra."@en . . . . . "# Martin LA, Head JE, Pancholi S, Salter J, Quinn E, Detre S, Kaye S, Howes A, Dowsett M, Johnston SR: The farnesyltransferase inhibitor R115777 (tipifarnib) in combination with tamoxifen acts synergistically to inhibit MCF-7 breast cancer cell proliferation and cell cycle progression in vitro and in vivo. Mol Cancer Ther. 2007 Sep;6(9):2458-67. \"Pubmed\":http://www.ncbi.nlm.nih.gov/pubmed/17876043 # Wang CC, Liao YP, Mischel PS, Iwamoto KS, Cacalano NA, McBride WH: HDJ-2 as a target for radiosensitization of glioblastoma multiforme cells by the farnesyltransferase inhibitor R115777 and the role of the p53/p21 pathway. Cancer Res. 2006 Jul 1;66(13):6756-62. \"Pubmed\":http://www.ncbi.nlm.nih.gov/pubmed/16818651"@en . "The farnesyltransferase inhibitors (FTIs) are a class of experimental cancer drugs that target protein farnesyltransferase with the downstream effect of preventing the proper functioning of the Ras protein, which is commonly abnormally active in cancer. After translation, RAS goes through four steps of modification: isoprenylation, proteolysis, methylation and palmitoylation. Isoprenylation involves the enzyme farnesyltransferase (FTase) transferring a farnesyl group from farnesyl pyrophosphate (FPP) to the pre-RAS protein. Also, a related enzyme geranylgeranyltransferase I (GGTase I) has the ability to transfer a geranylgeranyl group to K and N-RAS. Farnesyl is necessary to attach RAS to the cell membrane. Without attachment to the cell membrane, RAS is not able to transfer signals from membrane receptors (Reuter et al., 2000)."@en . . . . . . . "Investigated for use/treatment in colorectal cancer, leukemia (myeloid), pancreatic cancer, and solid tumors."@en . . . " "@en . . "Humans and other mammals"@en .