Expression of stanniocalcin in zona glomerulosa and medulla of normal human adrenal glands, and some adrenal tumors and cell lines

Stanniocalcin (STC) is a calcium (Ca)-regulating hormone that was originall y discovered in the fish Stannius body, which is a unique endocrine organ. Hypercalcemia increases STC secretion, which inhibits Ca uptake by the gill s and normalizes serum Ca level. In this study we investigated the STC expr ession in human normal and abnormal adrenal cells. Immunohistochemistry usi ng monoclonal antibody against STC revealed specific staining in zona glome rulosa and medulla of normal human adrenal glands. STC was also detected in human adrenal tumors, such as pheochromocytoma, differentiated neuroblasto ma, and aldosterone-producing adenoma, and cultured adrenal tumor cells (ra t pheochromocytoma PC-12 cells and human neuroblastoma NB-1 cells). However , undifferentiated human adrenal neuroblastoma was negative for STC stainin g. Reverse transcription polymerase chain reaction demonstrated STC mRNA ex pression in cultured PC-12 cells and NB-1 cells. Following several studies indicating that zona glomerulosa cells of adrenal glands express neuroendoc rine properties, STC expression in normal and abnormal adrenal cells provid es additional evidence to support the neuroendocrine differentiation of the se cells. In conclusion, STC may be useful as a new cell marker of adrenal glands under physiological and pathological conditions.