Targeting the HGF/SF receptor c-met using a hammerhead ribozyme transgene reduces in vitro invasion and migration in prostate cancer cells.
BACKGROUND
Hepatocyte growth factor scatter factor (HGF/SF) elicits a number of biological activities including invasion and migration through activation of its tyrosine kinase receptor c-Met. Over expression of c-Met has been implicated in prostate cancer development and progression. This study examined the effect of a ribozyme transgene, designed to inhibit human c-Met expression, and its impact on in vitro invasion and migration in prostate cancer.


METHODS
A transgene (Met 560) consisting of U1 snRNA, hammerhead ribozyme, and antisense was cloned into a modified pZeoU1-EcoSpe vector and transfected into DU-145 cells. The effect of HGF/SF was tested on prostate cancer cells whose expression of c-Met had been blocked by way of a ribozyme transgene.


RESULTS
Met 560 stable transfectants (DU-145(+/+)) manifested a complete loss of c-Met expression at mRNA and protein levels. In contrast, control plasmid (DU-145(+/-)) and wild-type DU-145 cells (DU-145(-/-)) had similar levels of c-Met expression. HGF/SF significantly increased the in vitro invasiveness (mean 47.71 +/- SE 7.75; P < 0.01 vs. control 24.14 +/- 1.34), and migration (mean 48.44 +/- SE 3.51; P < 0.01 vs. control 22.95 +/- 1.47) of DU-145(-/-) cells, respectively. Similarly, HGF/SF also increased the invasion (62.33 +/- 6.34; P < 0.001 vs. control 24.5 +/- 2.35) and migration (46.14 +/- 2.26; P < 0.01 vs. control 21.82 +/- 1.62) of DU-145(+/-) cells. In contrast, DU-145(+/+) cells had lost its response to HGF/SF induced invasion (22.33 +/- 2.08; P > 0.05 vs. control 23.5 +/- 2.11) and migration (24.12 +/- 0.86; P > 0.05 vs. control 23.27 +/- 0.81).


CONCLUSIONS
Targeting the HGF/SF receptor by way of a hammerhead ribozyme encoding antisense to c-Met, is an effective method to reduce the invasive or migration potential in prostate cancer, and may have important therapeutic implications.
Davies
Gaynor
G
Metastasis Research Group, University Department of Surgery, University of Wales College of Medicine, Heath Park, Cardiff, United Kingdom. DAVIESG11@cf.ac.uk
Watkins
Gareth
G
Mason
Malcolm D
MD
Jiang
Wen G
WG
D002465:Cell Movement; D015972:Gene Expression Regulation, Neoplastic; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D008297:Male; D009361:Neoplasm Invasiveness; D011471:Prostatic Neoplasms / Q000235:genetics / Q000473:pathology*; D019859:Proto-Oncogene Proteins c-met / Q000096:biosynthesis* / Q000494:pharmacology*; D016337:RNA, Catalytic / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D014162:Transfection; D019076:Transgenes; D014407:Tumor Cells, Cultured
D016337:RNA, Catalytic; D012333:RNA, Messenger; C427204:hammerhead ribozyme; D019859:Proto-Oncogene Proteins c-met