ABSTRACT
The effect of different potassium concentrations on changes in steroidogenic acute regulatory protein (StAR) and cytochrome P-450(SCC) in human adrenal cortex tissue was studied. A rise in K+ concentration in incubation medium to 8.5 mM caused an increase in StAR and cytochrome P-450(SCC) mRNA level in adrenocorticocytes by 70 and 76%, respectively, compared with control. Thus, potassium ions caused an enhancement of minerocorticoid synthesis in the adrenal cortex, which is associated with mechanisms that regulate the intensity of expression of StAR and cytochrome P-450(SCC) on a transcriptional level.
Subject(s)
Adrenal Cortex/drug effects , Cholesterol Side-Chain Cleavage Enzyme/genetics , Phosphoproteins/genetics , Potassium/pharmacology , Adrenal Cortex/metabolism , Cholesterol/metabolism , Cholesterol Side-Chain Cleavage Enzyme/metabolism , Electrophoresis, Agar Gel , Gene Expression , Humans , Phosphoproteins/metabolism , Polymerase Chain Reaction , Potassium/metabolism , RNA, Messenger/analysis , RNA, Messenger/biosynthesis , Tissue Culture TechniquesABSTRACT
A comparative analysis of the expression of both, RET/PTC1 and RET/PTC3 oncogenes in papillary thyroid carcinomas (PTC) of patients from different age groups was carried out. Those were the following groups: children (mean age - 13 years, mean latency period - 13 years), young adults (mean age - 24 years, mean latency period - 14 years), adults (mean age - 38 years, mean latency period - 22 years). The presence of RET/PTC oncogenes was detected using polymerase chain reaction. In all cases the samples of both tumor and normal thyroid tissue were studied. It was established that induction of both, RET/PTC1 and RET/PTC3 rearrangements was present only in carcinoma samples. In PTCs the percentage of RET/PTC-positive tumors with increasing the age of patients has been decreasing. It should be noted that the part of carcinomas with induction of RET/PTC1 did not change with increasing the age of patients. At the same time the frequency of RET/PTC3 rearrangements with the increasing both the latency period and age of patients, significantly decreased. In conclusion, our data can evidence for the presence of correlation between the age of patients, latency period and induction of RET/PTC3 oncogenes.
Subject(s)
Neoplasms/genetics , Protein Isoforms/genetics , Proto-Oncogene Proteins c-ret/genetics , Adolescent , Adult , Age Factors , Carcinoma , Carcinoma, Papillary , Causality , Chernobyl Nuclear Accident , Female , Gene Expression Regulation, Neoplastic , Humans , Male , Neoplasms/epidemiology , Neoplasms/metabolism , Neoplasms/pathology , Polymerase Chain Reaction , Protein Isoforms/metabolism , Proto-Oncogene Proteins c-ret/metabolism , Thyroid Cancer, Papillary , Thyroid Neoplasms/epidemiology , Thyroid Neoplasms/genetics , Thyroid Neoplasms/metabolism , Thyroid Neoplasms/pathology , Tumor Microenvironment , Ukraine , Young AdultABSTRACT
The effect of corticotropin and inhibitor of protein kinase C, chelerythrine chloride, on the change of caspase-3 level and on the rate of DNA laddering in hyperplasia adrenal cortex tissue of patient with Cushing's syndrome was studied. It was established that ACTH caused significant antiapoptotic effect in the human adrenal cortex. The adding of ACTH to incubation medium caused a sharp decrease of the caspase-3 level in adrenocorticocytes. Chelerythrine chloride, on the contrary, increases the caspase-3 level by 22%. ACTH influence decreases DNA laddering. Either the adding of chelerythrine chloride to incubation medium, or the adding of chelerythrine chloride simultaneously with ACTH, led to the enhancing of DNA fragmentation. The obtained data suggest that antiapoptotic effect of ACTH in adrenal cortex tissue estimated according by the caspase-3 level and by the rate of DNA fragmentation depends on activation of protein kinase C. However, the intensification of DNA laddering can be also explained by cytotoxic effect, high level of interaction with DNA and strong intercalation ability of this alkaloid.
Subject(s)
Adrenal Glands , Adrenocorticotropic Hormone/pharmacology , Apoptosis/drug effects , Caspase 3/metabolism , Cushing Syndrome , DNA Fragmentation/drug effects , Adrenal Glands/drug effects , Adrenal Glands/enzymology , Adrenal Glands/pathology , Alkaloids/pharmacology , Benzophenanthridines/pharmacology , Culture Media , Cushing Syndrome/enzymology , Cushing Syndrome/metabolism , Cushing Syndrome/pathology , Humans , Hyperplasia , Protein Kinase C/metabolismABSTRACT
The messenger mechanisms mediating K+ regulatory signals in human adrenocorticocytes were studied. It was shown that potassium ions initiated decay of polyphosphoinositides to inositolphosphates and obviously diacylglycerol. The latter compounds activate protein kinase C as affected by different agonists. Using western blotting method we showed translocation of PKCalpha from cytosol to membranes after adrenal tissue preincubation in the medium with increased K+ content (8.5 mM). Translocation means activation of the enzyme. Activity of PKC increased in the microsomal fraction and did not change in cytosol. Increased concentration of K+ in the incubation medium also activates protein kinase A, although to a lesser extent compared to PKC. Unlike PKC activity of PKA was changed in cytosol as well. The possibility of involvement of several messenger systems in K+ signal transduction in human adrenocortical cells as well as the hypothesis on cross-talk between messenger mechanisms for main physiological agonists controlling aldosterone biosynthesis in the adrenals are discussed.
