A vasoactive intestinal peptide receptor analog alters the expression of homeobox genes.
A lipophilic analog of vasoactive intestinal peptide (VIP), stearyl-Nle(17)-neurotensin(6-11)VIP(7-28) (SNH), that inhibited lung cancer growth, has been previously described. The mechanism of SNH inhibition of cancer growth is still being elucidated. The present study examined the effects of SNH on homeobox genes in the colon cancer cell line HT 29 that expresses VIP receptors. Homeobox genes contain a characteristic DNA sequence, coding for a stretch of 61 amino acid homeodomain that binds specific DNA motifs. While the HOX gene family contains a single homeodomain, the POU gene family contains an additional DNA binding homeodomain. HT 29 cells were incubated with SNH; RNA was extracted and subjected to reverse-transcription-polymerase chain reaction (RT-PCR) with primers that matched the conserved area of the various HOX or POU genes. The PCR products that were altered by SNH treatment were sequenced. Three candidate SNH-responsive genes, the HOX A4, the HOX B5 and the PUO V transcription factor I (Oct-3) were identified. Semi-quantitative RT-PCR with specific primers confirmed the increase in HOX A4 and the decrease in Oct-3 expression levels following SNH treatment. Thus, the HOX A4 and the Oct-3 homeobox genes may partially mediate SNH activity on cancer cells.
Steingart
Ruth A
RA
Department of Clinical Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Israel.
Heldenberg
Eitan
E
Pinhasov
Albert
A
Brenneman
Douglas E
DE
Fridkin
Mati
M
Gozes
Illana
I
D017931:DNA Primers / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D005801:Genes, Homeobox; D019073:HT29 Cells / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D009496:Neurotensin / Q000494:pharmacology*; D050814:Octamer Transcription Factor-3; D012334:RNA, Neoplasm / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
D017931:DNA Primers; D004268:DNA-Binding Proteins; C489126:HOXB5 protein, human; D018398:Homeodomain Proteins; C484113:Hoxd3 protein, mouse; D050814:Octamer Transcription Factor-3; C494173:POU5F1 protein, human; D012334:RNA, Neoplasm; D014157:Transcription Factors; C439005:stearyl-Nle(17)-neurotensin(6-11)VIP(7-28); C073547:HOXA4 protein, human; D014660:Vasoactive Intestinal Peptide; D009496:Neurotensin