Calcium signaling in BRAF mutant
melanoma
Agnes Enyedi
Molecular Oncology Research Group
HAS - Semmelweis University
Budapest, Hungary
Semmelweis Symposium, 2015
The role of a Ca2+ transport ATPase
(PMCA) in the motility and metastatic
activity of BRAF mutant melanoma
cells.
Ca2+ channels initiate while Ca2+ pumps
terminate the Ca2+ signal
ON
OFF
Uhlén P, Fritz N. Biochem Biophys Res Commun,2010
Altered
2+
Ca signaling
in cancer
2+
Ca
signal patterns formed by
different PMCA variants
Plasma membrane Ca2+ATPase
PMCA 1-4, ATP2B 1-4
+ alternative splice (a, b, c...)
>20 PMCA variants
high PMCA
Pászty et al, Science Signaling 2015;8(364) ra19
Plasma membrane Ca2+ pump
(PMCA) in cancer
decreased PMCA4b expression in
colon and breast cancer cells
Ribitzey et al., Cell Calcium, 42 (2007) 590-605
Lee et al., Cell physiology, 301 (2011) C969-976
Varga et al., Cell Calcium, 55 (2014) 78-92.
BRAF signaling in melanoma
Ascierto et al. Journal of Translational Medicine 2012
PMCA4b is upregulated in BRAF mutant
melanoma cells after BRAF inhibition
BRAF (wt)
BRAF (m)
V – vemurafenib
G – GDC 0879
BRAF (wt)
BRAF (m)
Luca Hegedűs et al, Journal of Cell Science, under revision
High PMCA4b abundance is associated
with fast Ca2+ clearance
PMCA4b
antibody JA3
Luca Hegedűs et al, Journal of Cell Science, under revision
Vemurafenib inhibits migration of
BRAF mutant A375 cells
BRAF (m)
BRAF (wt)
Luca Hegedűs et al, Journal of Cell Science, under revision
GFP-PMCA4b over-expression in
melanoma cells
BRAF(wt)
BRAF(m)
BRAF (m)
BRAF (wt)
Luca Hegedűs et al, Journal of Cell Science, under revision
PMCA4b inhibits migration of BRAF mutant
A375 cells
GFP-A375
PMCA4b-A375
Luca Hegedűs et al, Journal of Cell Science, under revision
PMCA4b inhibits migration
but does not affect proliferation of BRAF
mutant A375 cells
Migration assay
Proliferation assay
vemurafenib
BRAF(m)
-PMCA4b
+PMCA4b
BRAF(wt)
Luca Hegedűs et al, Journal of Cell Science, under revision
PMCA4b decreases metastasis in vivo
SCID mouse
Number of animals with lung metastasis
Total area of tumors in each group
Luca Hegedűs et al, Journal of Cell Science, under revision
Conclusion
over-expression
PMCA4b
mutBRAF
vemurafenib
Decreased Ca2+ signaling
Did not change proliferation
Changed morphology
Reduced migration
Reduced metastastatic activity
PMCA4b is a putative metastasis suppressor
Acknowledgement
Molecular Oncology Research Group
of HAS-SE, Budapest
Ágnes Enyedi
Luca Hegedűs
Krisztina Lór
Katalin Pászty
Rita Padányi
Karolina Varga
Balázs Hegedűs
Tamás Garay
Eszter Molnár
Agnes Bilecz
József Tímár
National Koranyi Institute of Pulmonology,
Budapest
Balazs Döme
Szilvia Török
Medical University of Vienna
Eniko Kallay
Luca Hegedűs
Walter Berger
Michael Grusch
Matthias Wolf
Funding
OTKA K101064
OTKA ANN110922
KTIA AIK12-1-2012-0025
TRANSRAT KMR-12-1-2012-0112