cyclic-gmp and Sarcoma

Since the cyclic nucleotides (CN) adenosine 3',5'-monophosphate (cAMP) and guanoside 3',5'-monophosphate (cGMP) are involved in the regulation of cell proliferation and tumor growth in vitro, a study was made of the levels of these compounds in the lumbar cerebrospinal fluid (CSF) of 20 patients with intracranial and spinal tumors. In the presence of benign or malignant intracranial tumors there was a slight and not significant decrease of cAMP as well as cGMP levels in the CSF, as compared to control patients. While there was no significant correlation between the levels of the two CN in controls, there was a positive correlation in tumor patients. Total protein content and cAMP were negatively correlated in malignant intracranial tumors. Possible influences of tumor growth and intracranial pressure increases on CN levels are discussed. In spinal tumor patients normal CN levels were observed. However, in a patient with meningeal sarcoma an extremely marked elevation of cAMP occurred in parallel with the extension of the tumor to the spinal meningeal space, suggesting massive secretion of cAMP from the tumor cells.

Topics: Adolescent; Adult; Aged; Brain Neoplasms; Cyclic AMP; Cyclic GMP; Female; Humans; Male; Meningeal Neoplasms; Middle Aged; Sarcoma; Spinal Neoplasms

Adenylate, guanylate cyclase and protein kinases in a fibrous sarcoma originating from rat prostate have been studied. A decrease in levels of adenosine 3', 5'-monophosphate (cyclic AMP) and adenylate cyclase activities and an increase in levels of guanosine 3',5'-monophosphate (cyclic GMP) and guanylate cyclase activities were observed in the tumor tissue when compared with the normal prostatic tissue of rats. Protein kinases from the tumor and the prostate were both responsive to exogenous cyclic AMP, with an apparent Ka of 0.08 muM in the tumor and of 0.11 muM in the prostate. It is of interest that the protein kinases from the tumor responded to cyclic AMP to the same extent as was observed in the enzyme preparation from the prostate. The protein kinase from the tumor was more sensitive to cyclic GMP than that from the prostate, showing an apparent Ka of 0.88 muM in the tumor and of 4.85 muM in the prostate. This tumor has been characterized with an increase in guanylate cyclase activities with a subsequent rise in cellular cyclic GMP and an increased sensitivity of the protein kinase to cyclic GMP.

Topics: 3',5'-Cyclic-AMP Phosphodiesterases; Adenylyl Cyclases; Animals; Carrier Proteins; Cyclic AMP; Cyclic GMP; Dose-Response Relationship, Drug; Guanylate Cyclase; Male; Prostate; Prostatic Neoplasms; Protein Kinases; Rats; Sarcoma