Silencing of Wnt-1 by siRNA induces apoptosis of MCF-7 human breast cancer cells.
OBJECTIVE
Wnt family of secreted-type glycoproteins plays key role in carcinogenesis and embryogenesis. Signals of Wnts are transduced through seven-transmembrane-type Wnt receptors encoded by Frizzled (Fzd) genes to the beta-catenin-Tcf pathway, the c-Jun-N-terminal kinase (JNK) pathway or the Ca(2+)-releasing pathway. Aberrant activation of the Wnt/beta-catenin signaling pathway is associated with a variety of human cancers. In human breast cancer, evidence of beta-catenin accumulation implies that the canonical Wnt signaling pathway is active in over 50% of carcinomas.


RESULTS
We found that in breast cancer cells overexpressing Wnt-1 siRNA anti-Wnt-1 induced apoptosis and caused changes in downstream proteins levels. Among treated cells there were 71% apoptotic cells in comparison to cells treated with scrambled siRNA (6%) and control cells (6%) after 48 h (p < 0.01).


METHODS
To examine if Wnt-1 signal is essential for cancer cell survival, we investigated the effect of Wnt-1 gene silencing in triggering of apoptosis in MCF-7 breast cancer cell line. Light microscopy, viability/cytotoxicity tests, flow cytometry, real-time PCR and western blotting were used for evaluation of the morphological features of cell death, percentage of apoptotic cells, Wnt-1 mRNA and protein level.


CONCLUSIONS
Our results significantly indicate that anti-Wnt-1 siRNA inhibits Wnt-1 signaling, inducing apoptosis in human breast cancer MCF-7 cells and thus may serve as a potential anti-cancer drug.
Wieczorek
Maciej
M
Department of Research and Development, Celon Pharma Ltd., Lomianki, Poland.
Paczkowska
Aleksandra
A
Guzenda
Piotr
P
Majorek
Maria
M
Bednarek
Andrzej K
AK
Lamparska-Przybysz
Monika
M
D017209:Apoptosis / Q000235:genetics* / Q000502:physiology; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000235:genetics; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D020868:Gene Silencing; D006801:Humans; D011506:Proteins / Q000032:analysis / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology; D051155:Wnt1 Protein / Q000235:genetics / Q000378:metabolism*; D051176:beta Catenin / Q000096:biosynthesis / Q000235:genetics
D011506:Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C495247:WNT1 protein, human; D051155:Wnt1 Protein; D051176:beta Catenin