Synthetic microRNA designed to target glioma-associated antigen 1 transcription factor inhibits division and induces late apoptosis in pancreatic tumor cells.
OBJECTIVE
To determine whether the synthetic microRNAs (miRNA) could effectively target tumor cells we designed several miRNA complementary to glioma-associated antigen-1 (Gli-1) mRNA and investigated their ability to inhibit tumor cell proliferation. The sonic hedgehog pathway is an early and late mediator of tumorigenesis in epithelial cancers. Activation of sonic hedgehog signaling seems to precede transformation of tissue stem cells to cancerous stem cells, with the Gli-1 transcription factor functioning as a mediator of environmental signals. Inhibiting cancer cell proliferation by targeting the Gli-1 effector pathway is difficult to achieve by chemotherapeutic agents or short interfering RNA.


METHODS
We hypothesized that targeting the 3'-untranslated region of Gli-1 mRNA would effectively inhibit tumor cell proliferation. To test this hypothesis, we used synthetic miRNAs of our own design and corresponding duplex/small temporal RNAs by introducing three-nucleotide loops in the 3'-untranslated region Gli-1 sequence of high GU content.


RESULTS
We found that miRNA (Gli-1-miRNA-3548) and its corresponding duplex (Duplex-3548) significantly inhibited proliferation of Gli-1+ ovarian (SK-OV-3) and pancreatic (MiaPaCa-2) tumor cells. The miRNAs mediated delayed cell division and activation of late apoptosis in MiaPaCa-2 cells. This is the first demonstration of inhibition of pancreatic tumor cell division by designed miRNA.


CONCLUSIONS
Gli-1 miRNAs should significantly add to the general understanding of the mechanisms of metastasis and contribute toward the design of better treatments for epithelial cancers.
Tsuda
Naotake
N
Department of Gynecologic Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030-4095, USA.
Ishiyama
Satoshi
S
Li
Yufeng
Y
Ioannides
Constantin G
CG
Abbruzzese
James L
JL
Chang
David Z
DZ
D020413:3' Untranslated Regions; D017209:Apoptosis / Q000235:genetics; D001483:Base Sequence; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D005260:Female; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D020868:Gene Silencing; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D035683:MicroRNAs / Q000138:chemical synthesis / Q000235:genetics; D008969:Molecular Sequence Data; D010051:Ovarian Neoplasms / Q000235:genetics* / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics*; D000071676:Zinc Finger Protein GLI1
D020413:3' Untranslated Regions; C400551:GLI1 protein, human; D035683:MicroRNAs; D012333:RNA, Messenger; D014157:Transcription Factors; D000071676:Zinc Finger Protein GLI1