Prostate cancer cells stimulated by calcium-mediated activation of protein kinase C undergo a refractory period before re-releasing calcium-bearing microvesicles

Dan Stratton; Colin Moore; Lei Zheng; Sigrun Lange; Jameel Inal

doi:10.1016/j.bbrc.2015.03.061

Prostate cancer cells stimulated by calcium-mediated activation of protein kinase C undergo a refractory period before re-releasing calcium-bearing microvesicles

Biochem Biophys Res Commun. 2015 May 8;460(3):511-7. doi: 10.1016/j.bbrc.2015.03.061. Epub 2015 Mar 19.

Authors

Dan Stratton¹, Colin Moore¹, Lei Zheng², Sigrun Lange³, Jameel Inal⁴

Affiliations

¹ Cellular and Molecular Immunology Research Centre, School of Human Sciences, London Metropolitan University, London, UK.
² Dept. of Laboratory Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, China.
³ University College London School of Pharmacy, 29-39 Brunswick Square, London WC1N 1AX, UK.
⁴ Cellular and Molecular Immunology Research Centre, School of Human Sciences, London Metropolitan University, London, UK. Electronic address: j.inal@londonmet.ac.uk.

PMID: 25797625
DOI: 10.1016/j.bbrc.2015.03.061

Abstract

MVs are released in response to several stress agents, in an attempt to prevent continued cellular damage. After an initial stimulus of prostate cancer cells with sublytic C5b-9 and activation of MV release through PKC, cells take at least 20 min to fully recover their ability to microvesiculate. This release of MVs through activation of sublytic C5b-9 was inhibited by the PKC inhibitor bisindoylmaleimide I but not the Rho kinase inhibitor, Y27632. After stimulus there is a rise of 79 nMs(-1) over 11 s, reaching a peak [Ca(2+)]i of 920 nM. The concentration of cytosolic calcium then falls steadily at 2.4 nMs(-1) over 109 s reaching baseline levels (50-100 nM) within 10-15 min. In PC3 cells the rate of release of MVs from stimulated cells also reaches a minimum within 10-15 min. Using fura-2 AM-loaded cells, upon stimulation, cells were found to release MVs with a concentration of intravesicular calcium estimated at ∼ 430 nM.

Keywords: Intravesicular calcium; Microvesicles; Refractory period; Sublytic C5b-9.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Blotting, Western
Calcium / metabolism*
Cell Line, Tumor
Complement Membrane Attack Complex / administration & dosage
Electrophoresis, Polyacrylamide Gel
Enzyme Activation
Humans
Male
Prostatic Neoplasms / enzymology
Prostatic Neoplasms / metabolism*
Protein Kinase C / metabolism*

Substances

Complement Membrane Attack Complex
Protein Kinase C
Calcium