Role of hormonal factor in development of primary and secondary tumorous process in the brain

Abstract

Introduction. Causes of the development onset of primary malignant cerebral neoplasms have not yet been determined. Not excluded is a possibility of unfavorable effect of the environment, genetic abnormalities, changes alterations in the hormonal background as well as metabolism, ionizing radiation: possible is also the role of viral infections and injuries. One of the main most severest complications of malignant tumors remain are metastatic lesions of the central nervous system whose proportion increases as with the patients’ longlivity. Cerebral metastases of malignant tumors are encountered more often than primary neoplasms of the central nervous system. The brain is not only a hormone-dependent organ the effect of sex hormones as early the embryonic state conditions normal development of the body as a whole and controls the sex related differentiation. It is known that neurons and glyocites like gonads and adrenal glands are able to produce steroid hormones. The enzymes responsible for the synthesis of neurosteroids were detected in the brain tissue in the embryonic period of the development. The human brain is not only a hormone-dependent organ effect influence of sex hormones as early as in the embrional state conditiones normal development of the body as a whole and controls sexual gender differentiation. It is known that neurons and glyocytes like gonads and adrenal glands are able to produce steroid hormones. Enzymes responsible for synthesis of neurosteroids were revealed in cerebral tissue both in during the embryonic period of the development and in adult condition. Besides there are have been obtained large amount of data on the presence in the cerebral cells of receptors to steroidal hormones. In various periods of life the influence effect exerted by steroids on nervous cells can change the morphofunctional state of the brain and manifests as altering myelinization, neuronal growth, and differentiation of nerve cells. The present study was aimed at comparing the level of certain some hormones in tissue of glioblastomes, metastases of breast cancer into the brain and meningiomas, as well as the respective peritumoral zones. Materials and methods. Examined were samples of tissue obtained from a total of 56 patients admitted for operative treatment to our Department. Of these, 24 glioblastomas, 19 breast cancer metastases to the brain, 13 meningiomes without peritumoral edema. The histological control was carried out in all cases. The patients’ age varied form 35 to 72 years. During operative interventions we carried out removed neoplasms of the brain followed by biochemical study of the samples of tumor tissue and immediately adjoining to the tumorous foci tissue (perifocal zone). In 10 % of cytozolic fractions of tissue prepared on the potassium-phosphate buffer of pH 7.4 containing 0.15 of Tween-20 and 1 % of bovine serum albumin by means of immunoenzymatic assay (IEA) using standard test systems we determined the level of steroid hormones – cortisole, testosterone, progesterone, estradiole, estriole, prolactine (IEA, HEMA, Russia) estrone (IEA, DBC, Canada) as well as sex-steroid-binding globulin (IEA, Alcor-Bio, Russia) and hormones of adrenohypophysis – adrenocorticotropine (ACTH) and somatotropic hormone (STH). Results. The obtained findings showed that the most hormonally saturated were metastases of breast cancer. In them along with elevated levels of cortisole, prolactine ACTH and STH concentrations whose concentrations increased virtually in any proliferative process we determined growth of saturation of tissues with estrone and free testosterone on the background of decrease level of active metabolite of estrogens – estriole. Besides, disorders of the steroid metabolism also touched the perifocal zone. Presence of glioblastoma turned out characteristic of identity of tumorous tissue and the perifocal zone by the level of cortizole, which is not found observed if tumors of other genesis. In case of glioblastoms and their perifocal zones the ratio of cortizole to ACTH excedded the norm 2.1–2.5-fold. Meningiomas revealed high concentration of cortisole, ACTH, prolactine, STH, testosterone and sex-binding globulin, as well as a low level of progesterone. In the present study meningiomas turned out liders of production of prolactine and STH as well as estriolle with sufficiently low activity. However alterations of the hormonal background of meningiomas are local isolated form the rest tissues of the brain. Probably, increase of the level of prolactine and STH in tumor tissue is a marker of proliferation, but not malignant cell transformation