Generation of PEGylated VPAC1-selective antagonists that inhibit proliferation of a lung cancer cell line.
Vasoactive intestinal peptide (VIP) binds to two receptors, VPAC1 and VPAC2. Non-selective VIP antagonists have been shown to inhibit human cancer cell proliferation and reduce tumor growth in mice. Many human cancers over-express VPAC1 but not VPAC2. We show that VPAC1-selective antagonists can inhibit human cancer cell proliferation and identify five positions in the VPAC1-selective antagonist PG 97-269 that may be responsible for VPAC1 selectivity. Position 16 appears to be particularly critical for selectivity, as demonstrated in the replacement of Arg16 of PG 97-269 with the native VIP amino acid; this single change results in greatly reduced VPAC1 binding and selectivity. Finally, we show that site-specific conjugation with a 22kDa polyethylene glycol (PEG) at the C-terminus of VPAC1-selective antagonists further improves VPAC1-selective binding and has minimal effect on antagonistic activity. Our studies have further solidified VPAC1 as a cancer target and offer the possibility of generating highly potent VPAC1-selective antagonists with minimal number of mutations to reduce the risk of immunogenicity and potentially prolonged duration of action to allow more efficient treatment regimen.
Pan
Clark Q
CQ
Department of Cancer Biology, Bayer HealthCare Pharmaceuticals, West Haven, CT 06516, USA.
Hamren
Sarah
S
Roczniak
Steve
S
Tom
Irene
I
DeRome
Mary
M
D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D006224:Cricetinae; D003412:Cricetulus; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000494:pharmacology*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011485:Protein Binding / Q000187:drug effects; D011863:Radioimmunoassay; D051238:Receptors, Vasoactive Intestinal Polypeptide, Type I / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013329:Structure-Activity Relationship; D014660:Vasoactive Intestinal Peptide / Q000737:chemistry / Q000494:pharmacology
C110307:PG 97-269; D010446:Peptide Fragments; D051238:Receptors, Vasoactive Intestinal Polypeptide, Type I; D014660:Vasoactive Intestinal Peptide; D011092:Polyethylene Glycols