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Effects of prolactin on intracellular calcium concentration and cell proliferation in human glioma cells
Author(s) -
Ducret Thomas,
Boudina Sihem,
Sorin Bruno,
Vacher Anne Marie,
Gourdou Isabelle,
Liguoro Dominique,
Guerin Jean,
BressonBepoldin Laurence,
Vacher Pierre
Publication year - 2002
Publication title -
glia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.954
H-Index - 164
eISSN - 1098-1136
pISSN - 0894-1491
DOI - 10.1002/glia.10056
Subject(s) - biology , intracellular , extracellular , prolactin , cell growth , calcium in biology , glioma , signal transduction , cell culture , microbiology and biotechnology , endocrinology , medicine , hormone , biochemistry , cancer research , genetics
Prolactin (PRL) has several physiological effects on peripheral tissues and the brain. This hormone acts via its membrane receptor (PRL‐R) to induce cell differentiation or proliferation. Using reverse transcription–polymerase chain reaction (RT‐PCR) combined with Southern blot analysis, we detected PRL‐R transcripts in a human glioma cell line (U87‐MG) and in primary cultured human glioblastoma cells. These transcripts were deleted or not in their extracellular domains. We examined the effects of PRL on intracellular free Ca 2+ concentration ([Ca 2+ ] i ) in these cells in order to improve our understanding of the PRL transduction mechanism, which is still poorly documented. [Ca 2+ ] i was measured by microspectrofluorimetry using indo‐1 as the Ca 2+ fluorescent probe. Spatiotemporal aspects of PRL‐induced Ca 2+ signals were investigated using high‐speed fluo‐3 confocal imaging. We found that physiological concentrations (0.4–4 nM) of PRL‐stimulated Ca 2+ entry and intracellular Ca 2+ mobilization via a tyrosine kinase–dependent mechanism. The two types of Ca 2+ responses observed were distinguishable by their kinetics: one showing a slow (type I) and the other a fast (type II) increase in [Ca 2+ ] i . The amplitude of PRL‐induced Ca 2+ increases may be sufficient to provoke several physiological responses, such as stimulating proliferation. Furthermore, PRL induced a dose‐dependent increase in [ 3 H]thymidine incorporation levels and in cellular growth and survival, detected by the MTT method. These data indicate that PRL induced mitogenesis of human glioma cells. GLIA 38:200–214, 2002. © 2002 Wiley‐Liss, Inc.