vasoactive-intestinal-peptide and Mouth-Neoplasms

Oral cancer is a major health problem. The study of exfoliative cytology material helps in the differentiation of premalignant and malignant alterations of oral lesions. The objective of this study was to assess the feasibility of detecting oral cancer by targeting genomic VPAC (combined vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating peptide) receptors expressed on malignant oral cancer cells.. All patients with suspected oral cavity cancers/lesions formed the study group. The samples from the oral cavity lesion or suspicious area were collected with a cytology brush. The harvested material was examined for malignant cells by 1. the standard PAP stain and 2. targeting the VPAC receptors on the cell surface using a fluorescent microscope. Similarly, malignant cells were identified from cells shed in oral gargles.. A total of 60 patients with oral lesions were included in the study. The histopathological diagnosis was squamous cell carcinoma in 30 of these. The VPAC receptor positivity both on the brush cytology staining as well oral gargle staining was more sensitive than the brush cytology PAP staining. The accuracy of the various techniques was as follows, brush cytology PAP staining at 86.67%, brush cytology VPAC staining at 91.67% and oral gargle VPAC staining at 95%.. This preliminary study validates our belief that malignant cells in the saliva can be identified by targeting the VPAC receptors. The test is simple, easy, non-invasive and reliable in the detection of oral cancers.

Topics: Humans; Mouth Neoplasms; Pituitary Adenylate Cyclase-Activating Polypeptide; Receptors, Vasoactive Intestinal Peptide; Vasoactive Intestinal Peptide

The purpose of this study was to determine whether exposure of cultured chemically transformed hamster oral keratinocytes (HCPC-1) to an aqueous extract of smokeless tobacco (STE) potentiates DNA synthesis elicited by vasoactive intestinal peptide (VIP), an autocrine neuropeptide, and, if so, whether this response is associated with inactivation of neutral endopeptidase 24.11 (NEP 24. 11), an ectoenzyme that cleaves and inactivates VIP very effectively, in these cells. I found that STE and VIP each elicited a modest, albeit significant, increase in DNA synthesis in cultured HCPC-1 cells (P < 0.05). However, incubation of HCPC-1 cells with STE together with VIP evoked a significant, concentration- dependent increase in DNA synthesis that was mediated by VIP receptors. The effects of STE and VIP were synergistic. Maximal response was observed after a 48-h incubation. STE significantly attenuated NEP 24.11 activity in HCPC-1 cells at a time when VIP-induced DNA synthesis was maximal. Collectively, these data indicate that STE potentiates VIP-induced DNA synthesis in cultured oral keratinocytes, and that this response is temporally related to STE-induced inactivation of NEP 24.11 in these cells. I suggest that NEP 24.11 modulates the mitogenic effects of smokeless tobacco in the oral epithelium, in part, by inactivating VIP.

Topics: Animals; Antimetabolites; Bromodeoxyuridine; Cell Line, Transformed; Cricetinae; DNA; Enzyme Activation; Keratinocytes; Leukoplakia; Mesocricetus; Mouth Mucosa; Mouth Neoplasms; Neprilysin; Plants, Toxic; Tobacco, Smokeless; Vasoactive Intestinal Peptide

The human gene coding for vasoactive intestinal peptide was recently isolated and shown to contain seven exons. We now demonstrate that an intron-containing precursor RNA can be the major vasoactive intestinal peptide-related RNA in the cell, which is in contrast to most known genes. By RNA blot analysis using a variety of genomic and cDNA-related probes we show that in a human tumor producing vasoactive intestinal peptide, most of the RNA encoding the peptide is of the precursor type. Similar precursor transcripts were found in total rat brain RNA as well. A proof of the identity of the intron-containing RNA, cDNA clones corresponding to this RNA sequence have been isolated.

Topics: Animals; Base Sequence; Brain Chemistry; Cell Line; Cloning, Molecular; DNA; Exons; Humans; Introns; Molecular Weight; Mouth Neoplasms; Nucleic Acid Hybridization; Rats; RNA; RNA, Messenger; Vasoactive Intestinal Peptide

To understand the regulation of the production of peptide hormones, it is vital to elucidate their biosynthetic pathways. We chose to study a major regulatory peptide, vasoactive intestinal peptide (VIP), a peptide possessing both neurotransmitter and neurohormone actions. To identify the specific peptide mRNA we are using, as hybridization probes, radiolabeled synthetic oligodeoxynucleotides with sequence complementary to the predicted peptide mRNA sequence. Employing this approach, we identified and partially purified a approximately 1600-base long mRNA containing VIP related sequences which can be translated in vitro into VIP-immunoreactive polypeptides. Such mRNA was detected in normal VIP producing tissue (rat brain), as well as in a tumor producing VIP (human buccal tumor). This mRNA differs in size from a known VIP-mRNA identified in human neuro-blastoma cells, suggesting the possibility of different VIP-mRNAs in different cell types.

Topics: Animals; Base Sequence; Brain; Humans; In Vitro Techniques; Mouth Neoplasms; Nucleic Acid Hybridization; Oligodeoxyribonucleotides; Rats; RNA, Messenger; Vasoactive Intestinal Peptide