Cancer/testis genes expression in human melanoma cell lines

We analyzed the expression of 15 cancer/testis and four melanoma differentiation antigens in 21 metastatic melanoma cell lines using reverse transcriptase-polymerase chain reaction (RT-PCR) assay. On the basis of morphological characteristics, tumor cell lines were divided into three groups with high, moderate, and low grade of differentiation. Evaluation of gene expression and melanoma cell morphology has revealed a correlation between increased expression of cancer/testis genes and differentiation grade of cancer cells. The gene expression pattern for lymph node metastases and primary tumors exhibits the distribution of expression level and frequency similar to that found for established cell lines. Nevertheless, only 60% lymph node metastases or primary tumor tissue of randomly selected patients show marked expression of the most prominent cancer/testis genes, and almost 90% lesion tissue expresses at least one of 15 cancer/testis genes.

[Melanoma cell lines as the basis for antitumor vaccine preparation]

The aim of the study was to obtain cell lines from tumor samples, and to determine phenotypic cell characteristics in order to choose the optimal line for vaccine preparation. 15 cell lines with stable growth, varying in cultural growth character and cytomorphology, were obtained from samples taken from patients with metastatic skin melanoma. Immunofluorescense method was used to determine the expression of T- and B-lymphocyte markers, antigens of major histocompatibility complex (MHC) class I and II, and CD86 co-stimulating molecule in the cell lines. The expression of melanocyte differentiation antigens and cancer/testicular antigens was evaluated using immunocytochemical assay. The results allowed the authors to distinguish three types of melanoma cell lines according to the expression of MHC molecules: MHC-negative; MHC class I positive; MHC classes I and II positive.

[Her-2/neu, Ki-67 expression and ploidy in breast carcinoma]

Expression of the markers was studied immunocytochemically on cytological preparations of breast tumor, ploidy was assessed by flow cytofluorimetry. The material was divided into 2 groups: diploid--41.4% cases and aneuploid--58.6%. Hyperexpression of Her-2/neu in the first group was observed in 54.5%, in the 2nd group in 48.6% cases. Expression of Ki-67 in 63.4% and in 68.9%, respectively. Tumours with high proliferative activity were numerous in aneuploid tissues, and in diploid tumours moderate activity prevailed (p = 0.006). Direct correlation between the markers was observed, high expression of Ki-67 more frequently was associated with positive expression of Her-2/neu. Thus, aneuploid tumours with high proliferative activity and hyperexpression of Her-2/neu are more aggressive tumours of a large size.

[Comparison of immunocytochemical and immunohistochemical methods for biomarker detection in breast cancer]

The detection of the biological parameters of the tumor before the treatment beginning becomes of more importance. The present study aimed to carry out the comparative analysis of the molecular markers expression (P53, Ki-67, Her-2/neu, Bcl-2, Bax, ER, FasL and CD95) at the cytologic and the correspondent histologic samples. The 18 tissue samples of the breast cancer were investigated. The immunocytochemical and the immunohistochemical methods of the molecular markers determination were used. Our study showed the correlation between two methods and the possibility of the use of the immunocytochemical staining as routine method of the molecular markers expression determination.

[Apoptosis and proliferative activity of bone marrow cells in patients with aplastic syndromes as evidenced by trephine biopsy]

AIM

To clarify the effect of cyclosporin A (CSA) on the apoptosis and proliferative activity of bone marrow cells in patients with aplastic syndromes by trepanobiopsy evidence.

MATERIALS AND METHODS

The TUNEL immunohistochemical assay was used to study apoptosis of bone marrow cells in the histological specimens from 24 patients: 8 with refractory anemia (RA), 8 with acute small-proportion leukemias [RA with excessive blasts (RAEB) + RAEB in transformation (RAEBt)], 3 with acute non-lymphoblastic leukemia (ANLL), 5 with lymphogranulomatosis (LGM). Control apoptosis examination was made in 10 patients treated with CSA. The proliferative activity of bone marrow cell was evaluated by bone marrow histological specimens from 10 patients (8 patients with RA and 2 with RAEB + RAEBt) at the onset of disease and during CSA therapy in the immunohistochemical test with primary nuclear antigen Ki-67 antigen antibodies. Changes in the proliferative activity and degree of apoptosis of bone marrow cells were assessed in relation to the cellularity detectable by the histological specimens.

RESULTS

Patients with RA showed an increase in bone marrow cell apoptosis to 25.375 +/- 6.874 (-10.8 +/- 5.122 and 8.333 +/- 5.84 in controls and ANLL patients, respectively). The cells of hemopoiesis and stromal microenvironment are in the process of cell death. Higher bone marrow cellularity is observed in CSA-treated patients at clinical and hematological remission, which is followed by rises in the index of proliferation and the degree of apoptosis.

CONCLUSION

The clinical effect of CSA in patients with aplastic syndromes is induced by its direct or mediated stimulating effect on pluripotent stem cells of hemopoiesis, by increasing bone marrow cellularity at the expense of clonal and/or normal hemopoiesis.