Record Details

Mechanism of mitotic arrest induced by dolastatin 15 involves loss of tension across kinetochore pairs

DSpace at IIT Bombay

View Archive Info
 
 
Field Value
 
Title Mechanism of mitotic arrest induced by dolastatin 15 involves loss of tension across kinetochore pairs
 
Creator LOPUS, M
 
Subject Cancer
Microtubules
Tubulin
HeLa cells
Kinetochores
Dolastatin 15 (DL15)
ADVANCED SOLID TUMORS
BOVINE BRAIN TUBULIN
EVERY 3 WEEKS
MICROTUBULE DYNAMICS
VINCA-DOMAIN
PHASE-I
BETA-TUBULIN
SPINDLE
CHECKPOINT
ATTACHMENT
 
Description Dolastatin 15 (DL15) is a potent, tubulin-targeted, vinca-site binding, anticancer agent that induces mitotic arrest and inhibit cell proliferation in a variety of cell types. Several analogs of DL15, including LU 103793 and tasidotin, have been progressed to clinical trials for different types of cancer. DL15 has been known to interfere with cellular microtubules and purified tubulin in vitro. However, the molecular mechanism with which the peptide arrests cells in mitosis is poorly understood. This study reports a possible antimitotic mechanism of action of DL15. DL15 inhibited HeLa cell proliferation in a concentration-dependent manner with a half-maximal inhibitory concentration (IC50) of 2.8 +/- A 0.3 nM, induced mitotic arrest, disrupted cellular microtubules near its IC50 for cell proliferation, and inhibited the re-polymerization of cellular microtubules. By staining the centrosomes of DL15-treated cells with anti-gamma tubulin antibodies, the study found a significant reduction in interpolar distances in mitotic HeLa cells, indicating a disruption in the normal assembly dynamics of the microtubules. The study further found that DL15 induced a loss of tension across the kinetochore pairs as indicated by a reduction in interkinetochore distance. In response to this loss of tension, the tension-sensing checkpoint protein BuBR1 accumulated at the kinetochores, promoting mitotic arrest. In vitro, DL15 promoted formation of curved and fragmented polymers of microtubule proteins and inhibited tubulin decay in a manner similar to vinca-site binding agents such as phomopsin A. Together, the data indicate that the mitotic arrest induced by DL15 involves a loss of tension across the kinetochore pairs due to disruption of normal assembly dynamics of microtubules.
 
Publisher SPRINGER
 
Date 2014-10-15T17:14:16Z
2014-10-15T17:14:16Z
2013
 
Type Article
 
Identifier MOLECULAR AND CELLULAR BIOCHEMISTRY, 382(1-2)93-102
http://dx.doi.org/10.1007/s11010-013-1721-8
http://dspace.library.iitb.ac.in/jspui/handle/100/15301
 
Language en