Class III beta-tubulin and gamma-tubulin are co-expressed and form complexes in human glioblastoma cells.
We have previously shown that the neuronal-associated class III beta-tubulin isotype and the centrosome-associated gamma-tubulin are aberrantly expressed in astrocytic gliomas (Cell Motil Cytoskeleton 2003, 55:77-96; J Neuropathol Exp Neurol 2006, 65:455-467). Here we determined the expression, distribution and interaction of betaIII-tubulin and gamma-tubulin in diffuse-type astrocytic gliomas (grades II-IV) (n = 17) and the human glioblastoma cell line T98G. By immunohistochemistry and immunofluorescence microscopy, betaIII-tubulin and gamma-tubulin were co-distributed in anaplastic astrocytomas and glioblastomas and to a lesser extent, in low-grade diffuse astrocytomas (P < 0.05). In T98G glioblastoma cells betaIII-tubulin was associated with microtubules whereas gamma-tubulin exhibited striking diffuse cytoplasmic staining in addition to its expectant centrosome-associated pericentriolar distribution. Treatment with different anti-microtubule drugs revealed that betaIII-tubulin was not associated with insoluble gamma-tubulin aggregates. On the other hand, immunoprecipitation experiments unveiled that both tubulins formed complexes in soluble cytoplasmic pools, where substantial amounts of these proteins were located. We suggest that aberrant expression and interactions of betaIII-tubulin and gamma-tubulin may be linked to malignant changes in glial cells.
Katsetos
Christos D
CD
Department of Pediatrics, Drexel University College of Medicine and St. Christopher's Hospital for Children, Philadelphia, PA 19134, USA. Christos.Katsetos@DrexelMed.edu
Dráberová
Eduarda
E
Smejkalová
Barbora
B
Reddy
Goutham
G
Bertrand
Louise
L
de Chadarévian
Jean-Pierre
JP
Legido
Agustin
A
Nissanov
Jonathan
J
Baas
Peter W
PW
Dráber
Pavel
P
D000328:Adult; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D001932:Brain Neoplasms / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D002648:Child; D005909:Glioblastoma / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D046912:Multiprotein Complexes; D015739:Nocodazole / Q000494:pharmacology; D017239:Paclitaxel / Q000494:pharmacology; D014404:Tubulin / Q000235:genetics / Q000378:metabolism*; D050257:Tubulin Modulators / Q000494:pharmacology; D014747:Vinblastine / Q000494:pharmacology
D000972:Antineoplastic Agents, Phytogenic; D046912:Multiprotein Complexes; C498585:TUBB3 protein, human; D014404:Tubulin; D050257:Tubulin Modulators; D014747:Vinblastine; D017239:Paclitaxel; D015739:Nocodazole