Altered TUBB3 expression contributes to the epothilone response of mitotic cells

Narvi, Elli; Jaakkola, Kimmo; Winsel, Sebastian; Oetken-Lindholm, Christina; Halonen, Pasi; Kallio, Lila; Kallio, Marko J.

doi:10.1038/bjc.2012.553

Cited by 38 publications

(38 citation statements)

References 31 publications

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“…Moreover, the exogenous protein appears to be incorporated in microtubules, including those of the midbody (Supplementary Figure S2C), as previously reported. 41 The overexpression (Figure 4a) or knockdown ( Figure 4b) of TUBB3 had no effect on the basal rate of cytokinesis failure. The overexpression of TUBB3 in CIT-K-depleted HeLa cells significantly increased the ratio of binucleated cells generated within the observation time (Figure 4a).…”

Section: Resultsmentioning

confidence: 93%

Tissue-specific control of midbody microtubule stability by Citron kinase through modulation of TUBB3 phosphorylation

et al. 2015

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Cytokinesis, the physical separation of daughter cells at the end of cell cycle, is commonly considered a highly stereotyped phenomenon. However, in some specialized cells this process may involve specific molecular events that are still largely unknown. In mammals, loss of Citron-kinase (CIT-K) leads to massive cytokinesis failure and apoptosis only in neuronal progenitors and in male germ cells, resulting in severe microcephaly and testicular hypoplasia, but the reasons for this specificity are unknown. In this report we show that CIT-K modulates the stability of midbody microtubules and that the expression of tubulin β-III (TUBB3) is crucial for this phenotype. We observed that TUBB3 is expressed in proliferating CNS progenitors, with a pattern correlating with the susceptibility to CIT-K loss. More importantly, depletion of TUBB3 in CIT-K-dependent cells makes them resistant to CIT-K loss, whereas TUBB3 overexpression increases their sensitivity to CIT-K knockdown. The loss of CIT-K leads to a strong decrease in the phosphorylation of S444 on TUBB3, a post-translational modification associated with microtubule stabilization. CIT-K may promote this event by interacting with TUBB3 and by recruiting at the midbody casein kinase-2α (CK2α) that has previously been reported to phosphorylate the S444 residue. Indeed, CK2α is lost from the midbody in CIT-K-depleted cells. Moreover, expression of the nonphosphorylatable TUBB3 mutant S444A induces cytokinesis failure, whereas expression of the phospho-mimetic mutant S444D rescues the cytokinesis failure induced by both CIT-K and CK2α loss. Altogether, our findings reveal that expression of relatively low levels of TUBB3 in mitotic cells can be detrimental for their cytokinesis and underscore the importance of CIT-K in counteracting this event.

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Section: Resultsmentioning

confidence: 93%

Tissue-specific control of midbody microtubule stability by Citron kinase through modulation of TUBB3 phosphorylation

et al. 2015

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“…In addition, other microtubule-targeted drugs including estramustine, vincristine, and vinorelbine interact more weakly with βIII-tubulin than with other β-tubulin isotypes in vitro [32][33][34][35]. Epothilones, from which ixabepilone was derived, are also more effective when βIII-tubulin levels are reduced [15]. Differences in amino acid sequences of βIII-tubulin as compared to other β-tubulin isotypes [36] are likely responsible for the differences.…”

Section: Effects Of βIii-tubulin and Ixabepilone On Microtubule Dynammentioning

confidence: 95%

“…Drug binding and suppression of microtubule dynamic instability also impair many interphase functions of microtubules including migration, intracellular trafficking, and cell secretion [11][12][13]. Several studies have briefly reported some of ixabepilone's properties in cells [14,15] and in vitro [7][8][9], but there has been no full elucidation of its mechanism of action including its response to altered tubulin isotype expression.…”

Section: Introductionmentioning

confidence: 99%

Mechanism of action of ixabepilone and its interactions with the βIII-tubulin isotype

Lopus

Smiyun

Miller

et al. 2015

Cancer Chemother Pharmacol

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Ixabepilone (Ixempra, BMS-247550), a semisynthetic analog of epothilone B, is a microtubule-targeted drug in clinical use for treatment of metastatic or locally advanced breast cancer. Ixabepilone's binding and mechanism of action on microtubules and their dynamics, as well as its interactions with isotypically altered microtubules, both in vitro and in tumor cells, have not been described. Microtubules are dynamic polymers of the protein tubulin that function in mitosis, intracellular transport, cell proliferation, and migration. They continually undergo dynamic instability, periods of slow growth and rapid shortening that are crucial to these cell functions. We determined ixabepilone's microtubule binding and polymerization effects in vitro and also determined its effects on inhibition of dynamic instability in vitro and in cells, both with and without removal of the βIII isotype of tubulin. The βIII isotype of tubulin is associated with drug resistance and tumor aggressivity. We found that removal (in vitro) and knockdown (in cells) of βIII-tubulin led to increased inhibition of microtubule dynamic instability by ixabepilone. Depletion of βIII-tubulin from MCF7 human breast cancer cells also induced increased mitotic arrest by ixabepilone. Thus, βIII-tubulin expression suppresses the antitumor effects of ixabepilone, indicating that increased βIII-tubulin may be an important contributor to the development of resistance to ixabepilone.

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“…Epothilones from the myxobacterium Sorangium cellulosum are potential anticancer drugs that act as microtubule disrupters, similar to taxanes 164 . Several epothilone analogues are currently undergoing clinical trials: patupilone (also known as EPO-906 or epothilone B) has been through Phase III trials in the United States and Phase III trials are ongoing in the United Kingdom, Spain, and…”

Section: Applyingmentioning

confidence: 99%

The re-emergence of natural products for drug discovery in the genomics era

Harvey

Edrada-Ebel

Quinn

2015

Nat Rev Drug Discov

2,063

1,410

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Natural products have been a rich source of compounds for drug discovery. However, their use has diminished in the past two decades in part because of technical barriers to screening natural products in high-throughput assays against molecular targets. Here, we review advances in chemical techniques for the isolation and structural elucidation of natural products that have reduced these technological barriers. We also assess the use of genomic and metabolomic approaches to augment traditional methods of studying natural products, and highlight recent examples of natural products in antimicrobial drug discovery and as inhibitors of protein protein interactions. The growing appreciation of functional assays and phenotypic screens may further contribute to a revival of interest in natural products for drug discovery.

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Altered TUBB3 expression contributes to the epothilone response of mitotic cells

Cited by 38 publications

References 31 publications

Tissue-specific control of midbody microtubule stability by Citron kinase through modulation of TUBB3 phosphorylation

Tissue-specific control of midbody microtubule stability by Citron kinase through modulation of TUBB3 phosphorylation

Mechanism of action of ixabepilone and its interactions with the βIII-tubulin isotype

The re-emergence of natural products for drug discovery in the genomics era

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