[Effect of antisense RNA targeting Polo-like kinase 1 on cell cycle of lung cancer cell line A549].
OBJECTIVE
Expression of polo-like kinase 1 (Plk1), which has several functions in mitotic progression, is elevated in lung adenocarcinoma cell line A549. It suggests that over-expression of Plk1 relates to chemotherapy- and radiotherapy-resistance, and poor prognosis of lung cancer patients. This study was to investigate the effect of down-regulation of Plk1 on cell cycle of A549 cells using the technique of antisense RNA.


METHODS
Antisense RNA targeting Plk1 (pcDNA3.0-Plk1, pc3.0P) was designed and constructed, and transfected into A549 cells. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to examine expression of Plk1 gene. Cell proliferation was evaluated by BrdU stain; cell cycle changes and apoptosis were examined by flow cytometry; expression of alpha-tubulin was detected by immunofluorescence.


RESULTS
mRNA level of Plk1 was significantly lower in pc3.0P-transfected A549 cells than in control cells (P < 0.05). pc3.0P reduced Plk1 mRNA in A549 cells by 46.75% 24 h after transfection, and by 61.84% 48 h after transfection. Protein level of Plk1 was also decreased after transfection. Positive rate of BrdU stain in experimental cells was only 25.59% 48 h after transfection, which was significantly lower than that in control cells (P < 0.05). A549 cells showed a strong G(2)/M arrest and apoptosis 72 h after transfection. alpha-tubulin staining showed absence of microtubule connection,and spindle abnormalities.


CONCLUSIONS
Down-regulation of Plk1 interferes spindle formation, and inhibits cell proliferation, induces cell cycle arrest and apoptosis.
Zhou
Qiong
Q
Department of Respiratory Disease, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Health Ministry of China, Wuhan, Hubei, 430022, P. R. China.
Bai
Ming
M
Su
Yuan
Y
D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology*; D017209:Apoptosis; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000096:biosynthesis* / Q000235:genetics; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015536:Down-Regulation; D006801:Humans; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology*; D010957:Plasmids; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis* / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis* / Q000235:genetics; D016372:RNA, Antisense / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D014162:Transfection; D000097869:Polo-Like Kinase 1
D018797:Cell Cycle Proteins; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D016372:RNA, Antisense; D012333:RNA, Messenger; D000097869:Polo-Like Kinase 1