title: Fluorescent cyclin-dependent kinase inhibitors block the proliferation of human breast cancer cells.
abstract: Inhibitors of cyclin-dependent kinases (CDKs) are an emerging class of drugs for the treatment of cancers. CDK inhibitors are currently under evaluation in clinical trials as single agents and as sensitizers in combination with radiation therapy and chemotherapies. Drugs that target CDKs could have important inhibitory effects on cancer cell cycle progression, an extremely important mechanism in the control of cancer cell growth. Using rational drug design, we designed and synthesized fluorescent CDK inhibitors (VMY-1-101 and VMY-1-103) based on a purvalanol B scaffold. The new agents demonstrated more potent CDK inhibitory activity, enhanced induction of G2/M arrest and modest apoptosis as compared to purvalanol B. Intracellular imaging of the CDK inhibitor distribution was performed to reveal drug retention in the cytoplasm of treated breast cancer cells. In human breast cancer tissue, the compounds demonstrated increased binding as compared to the fluorophore. The new fluorescent CDK inhibitors showed undiminished activity in multidrug resistance (MDR) positive breast cancer cells, indicating that they are not a substrate for p-glycoprotein. Fluorescent CDK inhibitors offer potential as novel theranostic agents, combining therapeutic and diagnostic properties in the same molecule.
authors: Drug Discovery Program, Georgetown University Medical Center, Washington, DC 20057, USA.
authors: Venkata Mahidhar
authors: VM
authors: Yenugonda
authors: Tushar B
authors: TB
authors: Deb
authors: Scott C
authors: SC
authors: Grindrod
authors: Sivanesan
authors: S
authors: Dakshanamurthy
authors: Yonghong
authors: Y
authors: Yang
authors: Mikell
authors: M
authors: Paige
authors: Milton L
authors: ML
authors: Brown
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000494:pharmacology; D000225:Adenine / Q000031:analogs & derivatives; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000175:diagnosis / Q000188:drug therapy* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors*; D003619:Dansyl Compounds; D005260:Female; D005456:Fluorescent Dyes; D006801:Humans; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*
chemical_list: C557984:2-chloro-N-(2-(5-(dimethylamino)naphthalene-1-sulfonamido)ethyl)-4-(2-(1-hydroxy-3-methylbutan-2-ylamino)-9-isopropyl-9H-purin-6-ylamino)benzamide; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D003619:Dansyl Compounds; D005456:Fluorescent Dyes; D047428:Protein Kinase Inhibitors; D018844:Cyclin-Dependent Kinases; D000225:Adenine