Ribosomal protein P2: a potential molecular target for antisense therapy of human malignancies.
BACKGROUND
Ribosomal protein P2 is an important component of protein translation machinery. We hypothesized that antisense-mediated depletion may disrupt the proteome of cancer cells. This study includes experiments to ascertain whether this could be a useful approach for cancer therapies.


METHODS
MIA PaCa-2 and BxPC-3 cells were transfected with P2-antisense oligonucleotide or controls. Growth was assayed using MTT. Protein P2 was measured using Western blotting. Proteomes were compared using two-dimensional electrophoresis and changes were characterized by mass spectrometry. A macroarray was used to identify cancers which may be vulnerable.


RESULTS
Antisense-P2 reduced P2 levels by 63% (p < 0.05) and inhibited BxPC-3 growth to 65% of control (p < 0.05). Seventeen (5.4%) proteins changed on two-dimensional electrophoresis including Rho C, translationally-controlled tumor protein, vinculin, LDH, ribosomal protein L23a, F-actin capping protein and eIF-3. Breast cancer underexpressed P2 compared to normal tissue (p < 0.001).


CONCLUSIONS
Antisense-P2 technology has potential to slow growth of cancer cells. This effect is mediated through multiple proteomic changes.
Gardner-Thorpe
James
J
Department of Surgery, Brigham and Women's Hospital/Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA.
Ito
Hiromichi
H
Ashley
Stanley W
SW
Whang
Edward E
EE
D001483:Base Sequence; D001943:Breast Neoplasms; D002455:Cell Division / Q000187:drug effects; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000235:genetics; D009363:Neoplasm Proteins / Q000235:genetics; D009369:Neoplasms / Q000235:genetics* / Q000628:therapy*; D020411:Oligonucleotide Array Sequence Analysis; D016376:Oligonucleotides, Antisense / Q000627:therapeutic use*; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000473:pathology / Q000628:therapy; D010750:Phosphoproteins / Q000235:genetics*; D016133:Polymerase Chain Reaction; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D012269:Ribosomal Proteins / Q000235:genetics; D014158:Transcription, Genetic / Q000235:genetics; D014407:Tumor Cells, Cultured; D016596:Vinculin / Q000235:genetics
D009363:Neoplasm Proteins; D016376:Oligonucleotides, Antisense; D010750:Phosphoproteins; D012333:RNA, Messenger; D012269:Ribosomal Proteins; C031937:phosphoprotein P2, ribosomal; D016596:Vinculin; D007770:L-Lactate Dehydrogenase; D017346:Protein Serine-Threonine Kinases