vasoactive-intestinal-peptide and Bone-Neoplasms

It has previously been shown that radiotherapy leads to an increased level of neuropeptides in various organs. In the study we report here, we examined whether the plasma levels of two neuropeptides, vasoactive intestinal peptide (VIP) and calcitonin gene-related peptide (CGRP), are influenced by radiotherapy. Blood was collected at four time intervals after radiotherapy; 1-12 days after treatment for skeletal metastasis from prostatic carcinoma. The VIP- and CGRP-plasma levels, as analyzed by radioimmunoassay, were not statistically different between the different time points analyzed.

Topics: Bone Neoplasms; Calcitonin Gene-Related Peptide; Humans; Male; Prostatic Neoplasms; Time Factors; Vasoactive Intestinal Peptide

Vasoactive intestinal peptide (VIP) was modified at the C terminus with a spacer and four amino acids to serve as a chelating moiety. The modified peptide, TP 3654, was labeled with Tc-99m and evaluated in normal volunteers, as well as in patients with a history of cancer. Renal clearance (67%) was the primary route of excretion, with approximately 20% of the radioactivity clearing through the hepatobiliary system. No adverse reaction was noted in any of the subjects and all, except one small, of the known lesions as seen by CT, MRI, Tc-99m-MIBI, or mammography were correctly identified within a few minutes of an i.v. injection of approximately 10 mCi of Tc-99m-TP 3654 (specific activity 11.3 x 10(3) Ci/m mol). The scans were in concordance in nine patients. In the remaining two, one with a visible mass in the neck from high grade spindle cell sarcoma and the other with a palpable mass in a breast from ductal epithelial hyperplasia, were localized only with Tc-99m-TP 3654, but not with Tc-99m-MIBI. Both malignancies are known to express VIP receptors. The VIP analog promises to be a nontoxic and reliable agent for imaging cancers in humans that express VIP receptors.

Topics: Adenocarcinoma; Adult; Amino Acid Sequence; Autoradiography; Bone Neoplasms; Breast Neoplasms; Female; Humans; Male; Middle Aged; Molecular Sequence Data; Neoplasms; Organotechnetium Compounds; Osteosarcoma; Radionuclide Imaging; Radiopharmaceuticals; Receptors, Vasoactive Intestinal Peptide; Technetium Tc 99m Sestamibi; Vasoactive Intestinal Peptide

A number of studies have demonstrated the pivotal role of collagen molecules in modulating cell growth and differentiation. In order to analyze the direct effects of collagen type I on the osteoblastic phenotype, we have devised an in vitro culture system for studying the interactions between bovine collagen type I and Saos-2 cells, a human osteoblastic cell line. Saos-2 cells were cultured both on top of collagen-coated culture dishes as well as inside a three-dimensional collagen network. Plating on dishes treated with collagen induced maximal adhesion of Saos-2 cells after 24-hour incubation. Cells cultured on collagen gel matrix expressed about 2.5-fold more alkaline phosphatase when compared with untreated plastic dishes. On collagen-coated dishes the responsiveness of Saos-2 cells to parathyroid hormone was decreased, whereas no modifications were observed in the effect of vasoactive intestinal peptide on these cells. Using a microfluorimetric measurement of DNA, an increase of proliferation was observed in Saos-2 cells cultured on collagen gel. Saos-2 cells were also able to colonize collagen sponges and in this three-dimensional network they were able to synthesize osteocalcin, as assessed both by immunocytochemistry and radioimmunoassay. In this study we have demonstrated that bovine collagen type I exhibits favorable effects on attachment and functional and growth activities of a human osteoblastic cell line, encouraging its use as a bone graft material.

Topics: Alkaline Phosphatase; Bone Neoplasms; Cell Adhesion; Cell Differentiation; Cell Division; Cell Transformation, Neoplastic; Collagen; Cyclic AMP; Cytophotometry; DNA, Neoplasm; Extracellular Matrix; Fluorescent Antibody Technique; Gels; Humans; Immunohistochemistry; Microscopy, Electron; Osteoblasts; Osteocalcin; Osteosarcoma; Parathyroid Hormone; Phenotype; Radioimmunoassay; Tumor Cells, Cultured; Vasoactive Intestinal Peptide