Spontaneous myogenic differentiation was observed in 2 out of 15 monolayer cultures from schwannomas induced in BD1X rats by transplacental exposure to N-enthyl-N-nitrosourea (ENU). Cells were sorted following fluorescence-activating method with monoclonal antibody (Mab) 217c. Myotubes and numerous mononucleated cells no longer expressed the Schwann cell antigens 217c and S-100 protein, but rather revealed the presence of desmin, the alpha-sarcomeric form (alpha-sr) of actin, and the cell surface antigen specified by Mab RB21-7, a glycoprotein sharing an epitope with the neural cell adhesion molecule (N-CAM). Subcutaneous reimplantation of such cells into syngeneic animals resulted in the appearance of tumours composed of both S-100 positive Schwann cells and desmin and alpha-sr-actin positive rhabdomyoblasts, thus closely resembling the human "triton" tumour. With the use of the polymerase chain reaction and allele-specific oligonucleotide hybridization, DNA isolated from individual myotubes was analysed for the presence of a T-->A transversion mutation at nucleotide 2007 of the neu gene, which is diagnostic of ENU-induced rat schwannomas. All of the amplified DNA isolated contained the mutant neu allele, thus providing direct genetic proof for the capacity of mammalian neuroectodermal cells for myogenic differentiation.

Morphologically atypical cells were first detected on the 98th day after subcutaneous implantation to rats of a paraffin pellet containing 2 mg of 7,12-dimethylbenz(a)anthracene (DMBA). These cells subsequently formed groups and finally gave rise to malignant fibrous histiocytomas. Early atypical cells were located between proliferating fibroblasts and histiocytes in the center of a fibrous capsule surrounding the DMBA-pill. They exhibited a smooth cell surface, dilated rough endoplasmic reticulum, multiple Golgi complexes, and were often associated with newly formed collagen. These cells incorporated 3H-thymidine and 3H-proline intensively, and showed weak acid phosphatase activity, but no features typical for macrophages (microvilli, numerous lysosomes, high activity of acid phosphatase, nonspecific esterases, antigens recognized by monoclonal antibodies ED1 and OX-42, vital staining with trypan blue). Atypical cells also did not differentiate into muscle cells (no expression of desmin and the alpha-sarcomeric form of actin), nor into Schwann cells (no expression of S-100 protein). No point mutation of the neu gene at nucleotide 2007, which is specific for N-ethyl-N-nitrosourea and DMBA-induced malignant rat schwannoma cells, was detected by polymerase chain reaction-restriction fragment length polymorphism analyses of microscopically selected regions of individual 7 micron cryostat sections. These results support the view that malignant fibrous histiocytoma is derived from immature fibroblasts exhibiting pronounced phenotypic diversity during later stages of carcinogenesis.

DNA quantitation by flow cytometry was made in 36 patients with morphologically diagnosed prostatic cancer (PC) in stage II, III and IV (4, 14 and 18 patients, respectively). All the patients received adequate treatment. Aneuploid tumours were found in 25 patients (group 1), diploid ones in 11 patients (group 2). A 3-year survival in group 1 made up 65.5%, in group 2 all the patients survived 3 years. The recurrence-free survival was 22.2% and 78.8%, respectively. The above findings make it possible to regard flow cytometry DNA estimation as a reliable prognostic indication in PC.

Immunohistochemical analysis of the protein expression c-myc, ets 1, ets 2, TPR-met, c-fos, c-jun, c-ras-pan, p53, yes, src in 79 samples of normal, metaplastic squamous epithelium, intraepithelial and invasive squamous cell carcinoma of uterine cervix was performed using polyclonal rabbit antibodies to the synthetic peptides homologous active areas of corresponding oncoproteins. Higher content of myc, fos, ets2, p53, ras is noted in metaplasia, dysplasia and in tumours as compared to the normal tissues. Protein myc is revealed in the cytoplasm at a grave dysplasia and in the nucleus in the intraepithelial carcinoma: this may serve as a criterion at a differential diagnosis of these conditions. Expression of the oncoproteins fos, ets2, p53, src in the metaplastic squamous cell carcinoma was higher than in the true squamous cell (ectocervical) carcinoma. When compared to the advanced carcinomas, increase of ets2, p53, and at some degree that of myc, the increase is noted in the latter. Invasive carcinoma with a high level of oncoproteins showed a tendency to the synchronization of myc and ras expression. Poor prognosis was associated with a low level (before treatment) of the expression of the majority of the oncoproteins studied.

The dermatoglyphic analysis of finger and palm prints was conducted in oncologic patients living in the same town and in corresponding with respect to the number control groups of inhabitants of the same town that were matched to each patient by the most relevant risk factors. The study was based on 61 dermatoglyphic characters. Using computer pattern recognition programs sufficiently informative subcomplexes of these characters were formed. They permitted to discriminate between ill and control persons.

The comparative dermatoglyphic analysis of palms and fingers of seven children with different forms of macrodactyly showed that they are fairly similar to those of normal children. The differences concern certain flattening of papillary ridges and reduced parameters of the total ridge count in the patients. Only in two cases of macrodactyly an increase in the relative length of fingers was accompanied by an increase in number of epidermal ridges and in the distance between fingers. If macrodactyly is based on somatic mutations or recombinations, then, depending on the time when the resulting mutant cell clones appear (before or after the epidermal ridges are laid down), the increased size of finger rudiments will or will not affect the value of ridge count.

Adaptive repair is the restoration of chemically induced DNA breaks in human fibroblasts previously gamma-irradiated at low doses. The adaptive repair in xeroderma pigmentosum (XP) cells was compared to that in normal human fibroblasts. The obtained results suggest that the repair is inducible and error-free. Adaptive repair was not found in XP cells in experiments with 4-NQO. This is correlated with the presence of an excision repair defect in XP.

Upon exposures of Ehrlich ascites carcinoma cells to heat shock (44 degrees, 1 hr), oxidative stress or energy deprivation, their DNA undergoes fragmentation (35-45% after 5 hrs of incubation) which is considered as a hallmark of apoptosis. Prior to DNA fragmentation the cells exhibited blebbing (55-90% after 1 hr), thus being suggestive of cytoskeletal damage and a 1.5-2-fold increase in the Triton-insoluble protein concentration (protein aggregation) after 3 hrs. Rapid cell death (75% after 4 hrs) occurred only under oxidative stress. Electrophoresis of the Triton-insoluble protein fraction revealed that the common feature of all stress exposures used in this study was a dramatic increase in the aggregation of cytoskeletal proteins--actin and the 57 kDa protein. No dependence of DNA fragmentation on intracellular Ca2+ increase was found. Both DNA fragmentation and protein aggregation were suppressed by glucose, whereas Zn2+, an endonuclease inhibitor, suppressed only DNA fragmentation without any effect on protein aggregation. It is suggested that cytoskeletal damage may trigger tumor cell apoptosis.

In this investigation the primary structure of E1A and E1B regions of SA7 (C8) simian adenovirus integrated in malignant SH2 rat cell line was studied. Southern blotting revealed at least two copies of the SA7 oncogene integrated in the SH2 genome. PCR analysis of E1A and E1B regions showed heteroduplex structures, proving the different structure of the integrated copies. The heteroduplex molecules with different electrophoretic mobility were separated, and chains corresponding to different copies were sequenced according to the modified Sanger method. We found that two copies differ mainly in microsatellite regions, in E1A between positions 894-902 (GCG)3/(GCG)4, in E1B between positions 2037-2048 (GCA)3/(GCA)4. It is necessary to stress that all deviations found belong to the coding regions of the SA7 oncogene.

The tumours studied were as follows: benign carcinoids, well differentiated carcinomas (atypical carcinoids) and poorly differentiated tumours (small-cell carcinoma with neuroendocrine differentiation). Oncoproteins c-myc, c-fos, c-jun, L-myc, c-sis, c-ras, c-src, c-ets-1, c-met were studied immunohistochemically in the material obtained from 25 patients during the operations. A higher expression of c-fos, c-jun, c-ets-1 and c-met is observed at early stages of progression and that of c-myc and L-myc at later stages. Enhancement of c-myc and L-myc expression correlated with the invasiveness and lymphogenic metastasizing. Co-expression and negative correlation between some oncogenes are established. The data obtained may be used for prognosis and therapy.

Chromosomal examination was made in the bone marrow and lymphocytes of the peripheral blood of 37 children with acute leukemia. Of them 25 had acute lymphoblastic leukemia (ALL), 12 had acute nonlymphoblastic leukemia (ANLL). NA karyotype was registered in 13 patients (5 with ALL, 9 with ANLL), AA karyotype in 17 children (12 with ALL, 5 with ANLL). In All the following chromosomal markers were identified: del(6)/(q22), del(7)(q32), del(11)(q23), 9p+, t(8; 14) (q24; q32). In ANLL there were: 46, XY, t(3; 8)/46, XY; 47, XY, +16, +(2; 14)--M1-form; 46, XX, t(8; 21); 46, XX, t(8; 21)/46, XX--M2-form; 47, XX, +mar/46, XX; 47, XY, +12--M4-form; 46, XX, del(16)/46, XX, 47, XY, +16; 48, XY, +5, +8--M5-form FAB.

cDNA of HL-60 cells induced to differentiation into granulocytes was hybridized with the excess of mRNA of K 562 cells induced to differentiation into erythrocytes. Cloning of cDNA sequences characterizing the induced differentiation of HL-60 cells into granulocytes was performed. The clones obtained were shown to contain sequences encoding a zinc finger motif, which is specific for DNA-binding domain of protein activators of transcription.

The globin gene expression in normal and Rauscher virus-transformed murine erythroid cells and the effect of heatshock and cycloheximide (CHI) were investigated. The hybridization analysis of RNA transcripts synthesized using erythroid cell chromatin as a template with globin cDNA demonstrated the disturbance of globin gene transcription in transformed erythroblasts. Using the Northern hybridization analysis of poly(A) +RNA with pCR1 beta MG9 as a probe, the presence of a rather broad RNA set (from approximately 1500 to 450 nucleotides) in these cells was discovered, while hemoglobin was not synthesized. This indicated that the processing of globin mRNA was probably also disturbed. As a result of heatshock, the RNA set approached that in normal erythroid cells (500-650 nucleotides), and the proteins corresponding to globins were synthesized. The stable appearance of low molecular weight proteins and the irregular synthesis of HSP-90 and HSP-70 in response to heat shock were the characteristic features of transformed erythroblasts. After CHI treatment, the content of globin sequences in RNA of transformed erythroblasts increased and beta-globin protein chains appeared.

The authors studied a number of original genetic phenotypical markers in leukemia patients. They suggested the existence of polygenic impacts involved in leukemia genesis. Hence, leukemias may be linked with some gene markers. It was established that leukemic subjects had phenotypical frequencies of cerebral hemispheric and sighting eye asymmetry, density of ear wax, hair color significantly different from those in the population. Hence, the above markers may indicate individual predisposition to leukemias.

Stable mutant cells spEBR-5, resistant to ethidium bromide in concentration of 5 micrograms/ml, have been isolated by multistep selection in mouse myeloma cells sp2/0-Ag14. The spEBR-5 cells, selected with ethidium bromide, appeared to be cross resistant to unrelated drugs in connection with mdr/lb gene amplification and overexpression. Five specific chromosomal markers were detected in the karyotype of spEBR-5 cells as a result of chromosome structural rearrangement. No cytological manifestation of gene amplification such as HCR of chromosomes or DMs was found. A diffuse location of amplified sequences in chromosome(s) is suggested. The new mutant cell lines spEBR-5 can be used as a model for investigation of multidrug resistance mechanisms.