Suppression of tumor invasion and migration in breast cancer cells following             delivery of siRNA against Stat3 with the antimicrobial peptide PR39.
PR39, a porcine cathelicidin rich in the amino acids proline and arginine             can interact with the negatively charged component of the cell surface, and rapidly             penetrate cell membranes. Therefore, we hypothesized that PR39, as a membrane             penetrating peptide (MPP), could be exploited as a novel carrier to deliver siRNA             into the cell cytoplasm in order to knockdown target gene expression. Firstly,             a complex formation of PR39 with siRNA and its cellular colocalization were investigated             in our studies. Further, we optimized the ratio of the PR39/siRNA complex, cell/complex             incubation period and the concentration of siRNA. The results suggest that PR39             could form a complex with siRNA, and mediate translocation of the siRNA into 4T1             cells. The optimal ratio of siRNA with PR39 was 1:90 which was found to have a             maximum Stat3 gene silencing effect after 48 h treatment. Moreover, 4T1 cell proliferation,             cell cycle, invasion and migration were investigated. The results suggested that             Stat3 knockdown could not result in 4T1 cell proliferation inhibition and cell             cycle arrest, while invasion and migration of 4T1 cells were strongly inhibited.             Notably, the data also showed that in addition to inhibition of carcinogenesis,             single PR39 may play a role in cell invasion and migration. PR39 and Stat3 siRNA             displayed synergistic biological effects in inhibiting cell invasion and migration             of 4T1 cells, which was more prominent compared with the popular Lipofectamine             delivery system.
Department of Laboratory Medicine, Key Laboratory of Diagnostic Medicine, Ministry of Education, Chongqing Medical University, Chongqing 400016, PR China.
Wenxia
W
Tian
Bing
B
Li
Xiwen
X
Zhang
Weiqi
W
Dang
Xiaofei
X
Wang
Hao
H
Tang
Lin
L
Wang
Hong
H
Cao
Tingmei
T
Chen
D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000008:administration & dosage* / Q000737:chemistry / Q000235:genetics; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D059447:Cell Cycle Checkpoints / Q000235:genetics; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D049109:Cell Proliferation; D005260:Female; D016650:Fluorescein-5-isothiocyanate / Q000032:analysis / Q000378:metabolism; D020868:Gene Silencing; D018014:Gene Transfer Techniques; D051379:Mice; D008969:Molecular Sequence Data; D034741:RNA, Small Interfering / Q000008:administration & dosage* / Q000737:chemistry / Q000235:genetics; D050796:STAT3 Transcription Factor / Q000235:genetics*
D023181:Antimicrobial Cationic Peptides; D034741:RNA, Small Interfering; D050796:STAT3 Transcription Factor; C494087:Stat3 protein, mouse; C072212:PR 39; D016650:Fluorescein-5-isothiocyanate