The expression of PLK-1 in cervical carcinoma: a possible target for enhancing chemosensitivity.
BACKGROUND
Polo-like kinase-1 (PLK-1) is reported to be upregulated in a variety of human tumors and is implicated in cell proliferation and survival. However, its importance in cervical carcinoma has not yet been fully elucidated.


METHODS
We examined PLK-1 expression in cervical carcinoma tissues using immunohistochemical staining. Furthermore, we blocked PLK-1 expression in HeLa cells using specific siRNA and detected the cell cycle, cell proliferation and chemosensitivity using western blotting, MTT and flow cytometry.


RESULTS
We provide evidence that expression of PLK-1 exists in human cervical carcinoma tissues and establish an association with tumor size. Furthermore, we show that PLK-1 knockdown by transfection of siRNA induces accumulation of HeLa cells in the G2/M cell cycle phase and enhances cisplatin-induced apoptosis.


CONCLUSIONS
Our results indicate that PLK-1 production in HeLa cells might be critical in determining whether cells survive or undergo apoptosis. Therefore, targeting PLK-1 might be a promising strategy for enhancing sensitivity to chemotherapeutic reagents in cervical carcinoma.
Zhang
Yuan
Y
Department of Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Hubei, PR China. yuanzhang75@hotmail.com
Liu
Yu
Y
Yang
Yuan-Xian
YX
Xia
Jia-Hong
JH
Zhang
Hong-Xiu
HX
Li
Hua-Bin
HB
Yu
Chun-Zhao
CZ
D017209:Apoptosis / Q000502:physiology; D014408:Biomarkers, Tumor / Q000032:analysis*; D015153:Blotting, Western; D053148:Caspase 3 / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000096:biosynthesis*; D019008:Drug Resistance, Neoplasm / Q000502:physiology*; D005260:Female; D005434:Flow Cytometry; D006367:HeLa Cells; D006801:Humans; D007150:Immunohistochemistry; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis*; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis*; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D020133:Reverse Transcriptase Polymerase Chain Reaction; D002583:Uterine Cervical Neoplasms / Q000201:enzymology*; D000097869:Polo-Like Kinase 1
D014408:Biomarkers, Tumor; D053148:Caspase 3; D018797:Cell Cycle Proteins; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D000097869:Polo-Like Kinase 1