Effect of SP600125 on the mitotic spindle in HeLa Cells, leading to mitotic arrest, endoreduplication and apoptosis.

Kaouthar Abid,Abderraouf Kenani,Donia Mili,Imed Rjiba

doi:10.1186/s13039-016-0296-y

Kaouthar Abid, Abderraouf Kenani + Show 2 more

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https://doi.org/10.1186/s13039-016-0296-y

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Journal: Molecular cytogenetics	Publication Date: Nov 25, 2016
Citations: 12	License type: cc-by

Affiliation: University of Monastir

Abstract

BackgroundThe JNK inhibitor SP600125 strongly inhibits cell proliferation in many human cancer cells by blocking mitosis progression and inducing cell death. Despite, all this study, the mechanism by which SP600125 inhibits mitosis-related effects in human cervical cells (HeLa cells) remains unclear. In this study, we investigated the effects of SP600125 on the cell viability, cell cycle, and on the spindle assembly during mitosis in HeLa cells.MethodsTo explore this approach, we used a viability test, an immunofluorescence microscopy to detect Histone phosphorylation and mitotic spindle aberrations. Apoptosis was characterised using Western Blotting.ResultsTreatment of HeLa cells with varying concentrations of SP600125 induces significant G2/M cell cycle arrest with elevated phosphorylation of histone H3 within 48 h, and endoreduplication after 48 h. SP600125 also induces significant abnormal mitotic spindle. High concentrations of SP600125 (20 μM) induce disturbing microtubule assembly in vitro. Additionally, SP600125- induced delayed apoptosis and cell death was accompanied by significant poly ADP-ribose polymerase (PARP) cleavage and caspase-3 activation in the late phase (at 72 h).ConclusionOur results confirmed that SP600125 induce mitosis arrest in G2/M, endoreduplication, mitotic spindle aberrations and apoptosis.

Highlights

The Jun kinase (JNK) inhibitor SP600125 strongly inhibits cell proliferation in many human cancer cells by blocking mitosis progression and inducing cell death
SP600125 induces a dose-dependent inhibition in cell viability and expansion of cell size in human HeLa cells Recent studies have shown that SP600125, a pharmacological inhibitor of JNK, causes cell viability inhibition in certain cell types, including breast cancer [8], multiple myeloma [9], and B-lymphoma [10]
To confirm that SP600125 inhibited JNK activity, we realised a Western blot analysis using p-c-Jun antibodies in HeLa cells extract after their incubation with SP600125 during 48H

Summary

Introduction

The JNK inhibitor SP600125 strongly inhibits cell proliferation in many human cancer cells by blocking mitosis progression and inducing cell death. We investigated the effects of SP600125 on the cell viability, cell cycle, and on the spindle assembly during mitosis in HeLa cells. Microtubule polylerisation inhibitors eg., colchicines), the enzyme poisons (eg: amsacrine, and Adriamycin), catalytic inhibitors (eg: merbarone, aclarubicin) and physical agents that damage DNA, such as X-rays. Some of these microtubule-interfering agents, such as SP600125 is an anthrapyrazolone inhibitor of JNK that competes with ATP to inhibit the phosphorylation of c-Jun. JNK appears to be involved in cell proliferation, there is no evidence linking JNK activation to specific phases of the cell cycle. Recent studies have focused on the effects of JNK in the promotion of cell death, and it has been reported that the JNK-antisense oligonucleotide inhibits tumour growth and induces regression in a high number of cases [6, 7]

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