title: A possible usage of a CDK4 inhibitor for breast cancer stem cell-targeted therapy.
abstract: Cancer stem cells (CSCs) are one of the main reasons behind cancer recurrence due to their resistance to conventional anti-cancer therapies. Thus, many efforts are being devoted to developing CSC-targeted therapies to overcome the resistance of CSCs to conventional anti-cancer therapies and decrease cancer recurrence. Differentiation therapy is one potential approach to achieve CSC-targeted therapies. This method involves inducing immature cancer cells with stem cell characteristics into more mature or differentiated cancer cells. In this study, we found that a CDK4 inhibitor sensitized MDA-MB-231 cells but not MCF7 cells to irradiation. This difference appeared to be associated with the relative percentage of CSC-population between the two breast cancer cells. The CDK4 inhibitor induced differentiation and reduced the cancer stem cell activity of MDA-MB-231 cells, which are shown by multiple marker or phenotypes of CSCs. Thus, these results suggest that radiosensitization effects may be caused by reducing the CSC-population of MDA-MB-231 through the use of the CDK4 inhibitor. Thus, further investigations into the possible application of the CDK4 inhibitor for CSC-targeted therapy should be performed to enhance the efficacy of radiotherapy for breast cancer.
authors.affiliation: Research Center, Dongnam Institute of Radiological & Medical Sciences, Busan 619-953, Republic of Korea.
authors.forename: Yu Kyeong
authors.initials: YK
authors.lastname: Han
authors.forename: Jae Ho
authors.initials: JH
authors.lastname: Lee
authors.forename: Ga-Young
authors.initials: GY
authors.lastname: Park
authors.forename: Sung Hak
authors.initials: SH
authors.lastname: Chun
authors.forename: Jeong Yun
authors.initials: JY
authors.lastname: Han
authors.forename: Sung Dae
authors.initials: SD
authors.lastname: Kim
authors.forename: Janet
authors.initials: J
authors.lastname: Lee
authors.forename: Chang-Woo
authors.initials: CW
authors.lastname: Lee
authors.forename: Kwangmo
authors.initials: K
authors.lastname: Yang
authors.forename: Chang Geun
authors.initials: CG
authors.lastname: Lee
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D001943:Breast Neoplasms / Q000532:radiotherapy / Q000628:therapy*; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D051358:Cyclin-Dependent Kinase 4 / Q000037:antagonists & inhibitors*; D005260:Female; D006801:Humans; D058990:Molecular Targeted Therapy; D014411:Neoplastic Stem Cells / Q000187:drug effects* / Q000528:radiation effects; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D011836:Radiation Tolerance / Q000187:drug effects*; D011838:Radiation-Sensitizing Agents / Q000627:therapeutic use*
chemical_list: D047428:Protein Kinase Inhibitors; D011838:Radiation-Sensitizing Agents; D051358:Cyclin-Dependent Kinase 4