[Clinical perspectives of the study of RANK/RANKL/OPG system components in primary and metastatic bone tumor].

Disbalance of bone homeostasis, associated with malfunctioning of RANK/RANKL/OPG system underlies the oncological processes such as the destruction of bone, metastasis development, tumor progression. Pathological activity of system was described in such conditions, as breast cancer, prostate cancer, multiple myeloma, squamous cell carcinoma, Hodgkin's disease, and also metastasis in bones from lung cancer and other malignant diseases. In the literature, there is evidence of involvement of RANK/RANKL/OPG system in the pathogenesis of bone tumors (osteosarcoma, giant cell tumor of bone, chondroblastoma). Experimental data show that RANKL inhibitors can play a role in reducing tumor-induced lesions of bone in multiple myeloma, breast cancer, prostate cancer and lung cancer. Also this review presents data from clinical studies of the drug efficacy targeted on RANK/RANKL/OPG system and results of authors' study of the levels of this system's components and proinflammatory cytokines in blood serum of primary bone sarcoma patients.

[Ganglioneuroblastoma in Yemenite chameleon (Chamaeleo calyptratus): the first recorded case of a tumor of neuroectodermal histogenesis in reptiles].

Nerve tissue tumors are rarely encountered in reptiles and mainly represented by some documented cases of malignant peripheral nerve sheath tumor (MPNST). The paper is the first to describe a tumor mimicking MPNST by some ultrastructural features of tumor cells; however, significantly differing in the combination of immunohistochemical characteristics. Based on the data of electronic microscopy, immunohistochemistry, cytology, and histology, the tumor was classified as ganglioneuroblastoma. Since this nosological entity, unlike MPNST, cannot be assigned to a group of sarcomatoid tumors, the described pathology should be regarded as the first registered case of neuroectodermal histogenesis of tumors in reptiles.

[Primary renal osteosarcoma]. / Pervichnaia osteosarkoma pochki.

A rare case of a primary kidney osteosarcoma with fusiform and bone component is described in a 38-year-old male.

[Bone tumors: classification, nomenclature, diagnostic problems]. / Opukholi kostei: klassifikatsiia, nomenklatura, problemy diagnostiki.

Main principles of current classification and nomenclature of bone tumours and tumour-like lesions are presented. Association of pathological processes in the skeletons with functional features of certain anatomophysiological zones and processes of skeleton growth acceleration is shown. Main principles of bone tumours diagnosis are formulated and difficulties associated with lack of clinical information are outlined.

[Osteosarcoma: biochemical and endocrinological studies as a basis for its pathogenetic treatments]. / Biokhimicheskie i éndokrinologicheskie issledovaniia pri osteosarkome -- osnova patogeneticheskikh metodov lecheniia opukholi.

The paper considers data of the long-term studies of androgen metabolism, baseline serum levels of reproductive steroid hormones and their receptors in the tumor, in the blood concentrations of sex steroid-binding globulin and pituitary hormones, the expression of epidermal growth factor, its receptors and ligands, soluble Fas-antigen, vascular endothelial growth factor, angiogenin, and the content of calmodulin, cAMP in the osteosarcoma in 300 patients aged 14 to 56 years, which were made at the N. N. Blokhin Russian Cancer Research Center, Russian Academy of Medical Sciences. Analyzing the findings identified some lines in the study of new pathogenetic treatments for osteosarcoma, aimed at regulating androgen metabolism, correcting the cyclooxygenase pathway of arachidonic acid, the expression of receptors of epidermal growth factor and its ligands, the processes of neoangiogenesis in the tumor. A role of the above parameters in the pathogenesis of osteosarcoma is discussed.

[Prognostic significance of p53, HER-2/neu, Ki-67 and VEGF expression in chondrosarcomas]. / Prognosticheskoe znachenie ékspressii p53, HER2/neu, Ki-67 i VEGF v khondrosarkomakh.

Expression of the mutant protein-suppressor of tumor growth p53 and the receptor of epidermal growth factor of type II--HER-2/neu may serve as prognostic factors for patients with chondrosarcoma of malignancy grade II. Combined expression of these proteins in the tumor tissue correlates with shorter 5-year survival of recurrence-free patients. The data obtained may be used for prognosis of chondrosarcoma course and choice of adequate therapy.

[Cranial bone neoplasm in early triassic amphibia]. / Novoobrazovanie pokrovnykh kostei chereepa rannetriasovoi amfibii.

A neoplasm in cranial bone of an early Triassic amphibian has been investigated. Although no tissue has survived, the cranial flat bone is similar to that in living animals of the same class. Evidence is presented in support of a hypothesis that the neoplasm is a skeletal tumor which consists of non-functional bone and looks like an atypical tumorous bone of skeletal origin. It was identified as a parostotic osteosarcoma on the basis of macro- and microscopic and X-ray examination.

[Expression of the apoptosis inhibitor soluble Fas antigen in patients with malignant and benign bone neoplasms]. / Ekspressiia ingibitora apoptoza--rastvorimogo Fas-antigena u bol'nykh so zlokachestvennymi i dobrokachestvennymi novoobrazovaniiami kostei.

This paper presents results of comparative enzyme immunoassay of soluble serum Fas antigen (sFas) in 98 patients with benign and malignant bone tumors, 15 patients with mechanical bone traumas, and 60 normal individuals of compatible age. The prevalence and concentration of sFas were significantly greater in patients with bone tumors than in normal donors and patients with mechanical bone traumas. The association of sFas with the pathogenesis of primary bone tumors is discussed in the paper.

[Epidermal growth factor receptors in malignant and benign tumors in children]. / Retseptory épidermal'nogo faktora rosta v zlokachestvennykh i dobrokachestvennykh opukholiakh u detei.

The radioligand technique was used to study the amount of epidermal growth factor receptors (EGFR) in malignant and benign tumors in 32 children aged 8 months to 17 years. The membranous fraction of 11 of the 32 tumors studied showed EGFR equal to 10.1 to 1327 fmol/mg (163.0 +/- 117.5 fmol/mg, median 38.0 fmol/mg). The greatest amount of EGFR was found in breast fibroadenomas. There was no clear relationship of the frequency and level of EGFR expression to a nosological tumor entity in children. A possible role of the EGFR system in tumors in children is discussed.

[Chordoma]. / Khordoma.

Chordoma is characterized clinicomorphologically and epidemiologically using own observations for 1955-1995 and literature data. Chordoma is a rare tumor. Its histogenetic association with the notochorda remnants and location in the region of axial skeleton results in a grave clinical course due to alteration of nervous structures of the brain and spinal cord. The diagnosis is based on roentgenological data showing the connection of the tumor with axial skeleton (in sacral-coccygeus and occipital-basilar regions in 90% of cases) and on typical histologic structure.

[Bone tumors and androgen metabolism]. / Opukholi kostei i metabolizm androgenov.

The paper provides data of comparative assessment of activity of the key enzymes in metabolism of androgens in various morphological variants of sarcomas and benign bone tumors in 46 patients within the age range from 15 to 61, which were under treatment in the ORC named after N. N. Blokhin, RAMS, from 1996 to 1997. On the basis on publications and our own research results we can suggest that malignant human bone tumors of various histogenesis are subject to metabolic processes of testosterone (T), the principal androgen regulator in the bone tissue, as well as formation in bones of 5 alpha-dihydrotestosterone (DHT). One cannot exclude a possibility that metabolism of androgen in bone tissues is directed towards formation of other androgens (in addition to DHT), which may participate in the bone tissue regulation, for instance, 3 alpha- and 3 beta-diols; specific activity of the latter has recently been intensively scrutinized. One can expect that further research shall disclose the clinical significance of metabolism of androgens and of individual androgens in human bone formations.

[Metabolism of androgens in various histological variants of bone tumors]. / Osobennosti metabolizma androgenov v razlichnykh gistologicheskikh variantakh opukholei kostei.

The role of androgens in human normal and neoplastic bone tissues is still unclear. The paper presents data on metabolism of androgens in homogenates of malignant (osteosarcoma, chondrosarcoma, Ewing and giant cell) and benign primary tumors from 46 male and female patients aged 14-58 years. Using two substrates (testosterone and 5 alpha-dihydrotestosterone) for the first time are shown activities of main enzymes of androgen metabolism in all tumor types. 5 alpha-reductase activity was similar in all tumors, 3 alpha-hydroxysteroid dehydrogenase activity was the highest while that of 17 beta-hydroxysteroid dehydrogenase was the lowest. Unknown metabolite(s) of 5 alpha-dehydrotestosterone was discovered which may be hydroxy-metabolites of 5 alpha-androstane-3 beta, 17 beta-diol. A principal scheme of androgen metabolism in human neoplastic tissue is proposed.