Review Article

Peptide Receptor Targeting in Cancer: The Somatostatin Paradigm

Table 2

Main signalling systems regulated by the activation of SST receptors.

sst1 sst2 sst3 sst4sst5

cAMP production
 Adenylyl cyclase
Tyrosine phosphatases
 PTP
 SHP-1
 SHP-2
Ion channels and transporters
 Ca2+ channels
 K+ currents
 Na+/H+ exchanger 1 (NHE1)/▲
MAPK
 ERK1/2/▲/▲
 p38
 JNK
Tyrosine kinases
 c-Src
 JAK2
Phospholipid kinases
 PI3K/▲/▲
Cyclin-dependent kinase inhibitors
 p27kip1
 p21Cip1
 Zac1
Nitric oxide synthases
 nNOS▲/
 eNOS
Apoptotic pathways
 p53
 BAX
 Bcl-2

▲: activation, : inhibition, ∘: no effects.