title: Occurrence of Aurora A positive multipolar mitoses in distinct molecular classes of colorectal carcinomas and effect of Aurora A inhibition.
abstract: Aurora A "over-"expression may induce supernumerary centrosomes, respective multipolar mitoses, and aneuploidy. Here, we examined Aurora A positive multipolar mitoses in aneuploid, microsatellite-stable (MSS, "CIN-type") versus near-diploid, microsatellite-instable (MSI, "MIN-type") colorectal carcinomas (CRC) and CRC cell lines as well as the effect of Aurora A inhibition in CRC cell lines. In situ, three-dimensional immunofluorescence (3D-IF) revealed Aurora A positive multipolar mitoses in both CIN- (n = 8) and MIN- (n = 10) type primary CRCs with similar frequencies (CIN: 27 ± 14%; MIN: 34 ± 14%, P = 0.224). In vitro, Aurora A positive multipolar mitoses were detected in asynchronized or thymidine synchronized CIN-type (HT29, CaCo-2), but not MIN-type (HCT116, DLD-1) CRC cells. Nocodazole treatment arrested mitotic cells with multiple centrosomal Aurora A signals in CIN- and MIN-type CRC cells, albeit to a lower extent in CaCo-2 cells. This was associated with concomitant activation of Aurora A (T288 phosphorylation) and Polo-like kinase 1 (PLK-1, T210 phosphorylation). Aurora A inhibition by siRNA resulted in increased apoptosis (>50%) in all cell lines, but did not abolish PLK-1 expression. Double 3D-IF revealed that Aurora A siRNA treated, still viable CIN-type (HT29, CaCo-2) CRC cells were Aurora A negative and mostly in prophase/(pro)metaphase with maintained phosphorylated PLK-1 T210 expression. Aurora A positive multipolar mitoses occur in both aneuploid, CIN- and near-diploid MIN-type CRCs. This appears to be largely independent of Aurora A expression alone. Although Aurora A inhibition causes apoptosis in both CIN- and MIN-type CRC cells, remaining PLK-1 activation by other factors may affect therapeutic Aurora inhibition.
authors: Institute of Pathology, University Medical Center, Freiburg, Germany.
authors: Corinna
authors: C
authors: Herz
authors: Fabienne
authors: F
authors: Schlürmann
authors: Daniela
authors: D
authors: Batarello
authors: Christiane D
authors: CD
authors: Fichter
authors: Anja
authors: A
authors: Schöpflin
authors: Claudia
authors: C
authors: Münch
authors: Dieter
authors: D
authors: Hauschke
authors: Martin
authors: M
authors: Werner
authors: Silke
authors: S
authors: Lassmann
mesh_terms: D000782:Aneuploidy; D017209:Apoptosis; D064127:Aurora Kinases; D015153:Blotting, Western; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D049109:Cell Proliferation; D018385:Centrosome; D015179:Colorectal Neoplasms / Q000145:classification* / Q000235:genetics / Q000473:pathology*; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D018628:Gene Dosage; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007124:Immunoenzyme Techniques; D017404:In Situ Hybridization, Fluorescence; D053842:Microsatellite Instability; D008938:Mitosis; D009154:Mutation / Q000235:genetics; D009367:Neoplasm Staging; D011003:Ploidies; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics / Q000378:metabolism; D016283:Proto-Oncogene Proteins p21(ras); D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D018631:ras Proteins / Q000235:genetics / Q000378:metabolism; D000097869:Polo-Like Kinase 1
chemical_list: D064127:Aurora Kinases; D018797:Cell Cycle Proteins; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D048493:Proto-Oncogene Proteins B-raf; D016283:Proto-Oncogene Proteins p21(ras); D012333:RNA, Messenger; D034741:RNA, Small Interfering; D018631:ras Proteins; D000097869:Polo-Like Kinase 1; C117307:KRAS protein, human; C482119:BRAF protein, human