Despite significant improvement in the diagnosis and treatment of various human
carcinomas, the 5-year survival rate for
lung cancer remains below 20%.
Vasoactive intestinal peptide (VIP) is an important
neuropeptide in the control of lung physiology, and exerts its functions mainly through two receptor subtypes, VPAC1 and VPAC2. Receptors for VPAC1 and VPAC2 are present in human
lung cancer cells, but very limited information exists about the
mRNA expression of these
VIP receptor subtypes in
lung cancer specimens. The aim of the present study was to investigate by RT-PCR the
mRNA expression of the VPAC1 and VPAC2 receptors in surgical specimens of 43 human
lung cancer specimens and 7 normal lung samples.
mRNA expression of the
VPAC1 receptor was detected in 51% of the
tumor specimens, while the incidence of
mRNA expression for VPAC2 was 46%. Twenty-one percent of the
tumor samples expressed only the
VPAC1 receptor and 16% displayed only the
VPAC2 receptor, while 13 samples (30%) expressed neither subtype. Thirteen
cancer tissue specimens (30%), expressed both of these
VIP receptor subtypes. Three normal lung tissue specimens also displayed gene expression for VPAC1 and/or VPAC2 receptors. Our results support the additional investigation of the role of VIP and its receptors in human
lung cancer and suggest a further development of VIP analogs for therapeutic and imaging purposes in this
malignancy.