alpha-chymotrypsin and Testicular-Neoplasms

The pregnancy and tumor marker human chorionic gonadotropin (hCG) belongs to the family of the glycoprotein hormones. Information on epitope forming sequences of hCG and its subunits hCG alpha and hcg beta has significant impact on the examination of intra- and extracellular metabolism and the standardization of diagnostic assay systems. Variants of hCG appear in biological fluids with variable modifications on different parts of the molecule. These changes may influence the binding patterns of monoclonal antibodies (MCA), thereby causing erroneous results in hCG immunoassays. The aim of the present work was to investigate the influence of peptide bond cleavages and the loss of certain segments of the molecule, which were induced by proteases on the expression of the seven hCG alpha-(alpha 1-alpha 7), nine hCG beta- (beta 1-beta 9) and four hCG beta-core-fragment-epitopes (beta 10-beta 13), previously identified by us [1-10]. To this end, we digested hCG alpha and hCG beta with chymotrypsin. Hormone fragments were separated by high performance liquid chromatography (HPLC) and subsequently immunochemically examined by direct binding radioimmunoassay (DB-RIA), competitive RIA and immunoenzymometric assays (IEMA). Fractions containing hCG-like immunoreactivity were sequenced by Edman and carboxypeptidase-Y degradation. It appeared that: (I) Amino acids (AA) alpha 41-47 and the peptide bonds between AA alpha 40/41, alpha 47/48 and alpha 29/30 do not influence the expression of the 7 alpha-epitopes, (II) The absence of the hCG beta N-terminus plays a crucial role for the formation of epitopes beta 10 and beta 13. (III) Neither the presence nor the absence of the C-terminal peptide of hCG beta (hCG beta CTP, AA beta 114-145) has any importance for the expression of epitopes beta 1-beta 7 and beta 10-beta 13 (IV).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Biomarkers, Tumor; Choriocarcinoma; Chorionic Gonadotropin; Chymotrypsin; Female; Humans; Infant, Newborn; Male; Peptide Fragments; Pregnancy; Pregnancy Tests, Immunologic; Structure-Activity Relationship; Testicular Neoplasms; Uterine Neoplasms

Sertoli cell intracellular protein 1 (SCc1) and 2 (SCc2) are polypeptides found in rat Sertoli cell cultures incubated with either FSH or (Bu)2cAMP. They were first identified in [35S]methionine-labeled Sertoli cell lysates using two-dimensional gel electrophoresis. Here we extend these observations by showing that SCc1 and SCc2 are present in rat seminiferous tubules, ovaries, and granulosa cells incubated with either FSH or (Bu)2cAMP and in testicular peritubular cells incubated with (Bu)2cAMP. Peritubular cells do not, however, respond to FSH with the production of SCc1 and SCc2. Peptide mapping with N-chlorosuccinimide revealed that SCc1 and SCc2 have similar cleavage patterns, suggesting a common primary amino acid sequence that is modified posttranslationally. Metabolic labeling with [32P]orthophosphate provided direct evidence that SCc1 and SCc2 are phosphoproteins. A shift in mobility of SCc1 and SCc2 toward the basic region of the gel to positions designated SCc1' and SCc2' occurred when cell lysates were treated with alkaline phosphatase before electrophoresis, providing additional evidence that SCc1 and SCc2 are phosphoproteins. SCc1 and SCc2 are also shown to be mitochondrially-associated in the Sertoli cell. Peptide maps of SCc1, SCc2, SCc1', and SCc2' obtained by treatment with alpha-chymotrypsin, are identical to proteolytic maps of proteins pp30', p30, and pp30 from adrenocortical cells. SCc1, SCc2, SCc1', and SCc2' are homologous with regard to their regulated expression, electrophoretic mobility, and mitochondrial localization to the adrenal proteins pp30' and pp30 as well as a series of 30 kilodalton proteins from MA-10 Leydig tumor cells. Both the adrenal cell proteins and the Leydig tumor cell proteins are thought to participate in cholesterol transport to the inner mitochondrial membrane, providing substrate for the cholesterol side-chain cleavage enzyme complex, an activity which the Sertoli cell does not perform, suggesting that alternative functions must be sought for SCc1 and SCc2 in Sertoli cells.

Topics: Adrenal Cortex; Alkaline Phosphatase; Animals; Cells, Cultured; Chymotrypsin; Cyclic AMP; Electrophoresis, Polyacrylamide Gel; Female; Follicle Stimulating Hormone; Granulosa Cells; Leydig Cell Tumor; Male; Mitochondria; Peptide Mapping; Phosphorus Radioisotopes; Phosphorylation; Proteins; Rats; Rats, Sprague-Dawley; Seminiferous Tubules; Sequence Homology, Amino Acid; Sertoli Cells; Subcellular Fractions; Succinimides; Sulfur Radioisotopes; Testicular Neoplasms; Tumor Cells, Cultured

Using an ammoniacal silver nitrate stain, we have demonstrated typical microglial cells in three teratomas. Microglia appeared identical to their counterparts in the mature human brain, both resting and slightly hypertrophic types being present in differentiated nervous tissue, which also comprised astrocytes, neurones and ependyma. The implications of the presence of microglia with ectodermal derivatives in teratomas are discussed.

Topics: Adolescent; Adult; Aged; alpha 1-Antichymotrypsin; Astrocytes; Chymotrypsin; Female; Glial Fibrillary Acidic Protein; Humans; Male; Middle Aged; Nerve Tissue; Ovarian Neoplasms; Teratoma; Testicular Neoplasms