Increased risk for cancer in multiple myeloma patients and their first-degree relatives.

Analyzing data of 125 multiple myeloma patients, the authors found a 40-fold increased tumor incidence among the patients and their first-degree relatives as compared to the average population. These tumors were the same as those usually found among Hungarians. There was no difference as to the patient's blood group antigens in the families of myeloma patients with or without other tumor. IgA-type disease was found to be relatively more frequent in the group of patients who had tumor besides myeloma. In a prospective study, authors could not find mutation of suppressor gene p53 in 14 patients and their 16 healthy first-degree relatives. This may indicate that there is no p53 suppressor gene alteration responsible for the high-risk condition for tumorgenesis in this population.

The usefulness of in vivo gene expression investigations from peripheral white blood cells: a preliminary study.

Alterations of onco/tumour suppressor genes are involved in the formation of human hematological malignancies. Previously, in animal models, we demonstrated the applicability of in vivo gene expression investigations to monitor the effects of certain carcinogenic chemicals. In our present study we determined the expression of onco/suppressor genes from isolated peripheral white blood cells of patients with chronic myeloid leukaemia (CLL) and non-Hodgkin lymphoma (NHL). Gene expressions were determined by isolation of total RNA and slot blot hybridization with chemiluminescently labeled gene probes (Ha-ras, c-myc and p53) Expression levels were compared before and after treatment with a combined cytostatic protocol, containing cyclophosphamide, doxorubicin, vincristine and prednisolone (CHOP). Both the CLL and NHL group of patients exhibited significantly higher expression of the investigated genes than healthy controls. One month after the cytostatic treatment, we found considerably fewer individuals with overexpressed oncogenes than before the treatment. Our study proved that onco/tumour suppressor gene expressions could be used as biomarkers of certain hematological malignancies, and to monitor the therapeutical effect of cytostatic drugs.

In vivo effects of CHOP protocol on onco and suppressor gene expression: follow-up study.

In vivo investigation of onco/suppressor gene effects may provide new findings concerning chemical carcinogenesis. In earlier studies we pointed out the carcinogenic potential of COPP and ABVD chemotherapeutical protocols in "long-term" experiments. In another follow up study we proved the connection between the early gene expression changes and the late consequences of COPP and ABVD treatment during, a one year latency period. CHOP protocol is containing both proved carcinogenic cyclophosphamide and highly mutagenic doxorubicyn. CHOP protocol in "short-term" experiments shows strong effect on Ha-ras oncogene expression.

Effect of ABVD therapeutic protocol on oncogene and tumor suppressor gene expression in CBA/Ca mice.

The in vivo investigation of onco/suppressor gene effects may provide new information on chemical-environmental carcinogenesis. We previously described the elevation of onco/suppressor gene expression due to CHOP and COPP chemotherapeutical protocols in a CBA/Ca mouse model. Below we describe the results of the onco/suppressor gene expression studies after treatment with ABVD, a non-cyclophosphamide containing protocol. Expression of c-myc, Ha-ras, and p53 genes was investigated 1/2, 1, 3, 6, 12, 24 hours, 2 6 30 days, 6, and 12 months after treatment with a single dose of ABVD protocol. RNA was isolated from the thymus, spleen, liver, bone marrow, kidneys, and hybridzed with chemiluminescently labelled probes of Ha-ras, c-myc, and p53 genes. Significant changes of gene expression was found in the spleen and thymus, even after 30 minutes. The female spleen seemed to be more sensitive than the male one, but no sex difference was observed in the thymus. No significant alteration was detected in the other investigated organs.

In vivo effects of COPP protocol on onco- and suppressor gene expression in a 'follow up study'.

In vivo investigation of onco or suppressor genes may provide new information concerning chemical carcinogenesis. In earlier studies we illustrated the carcinogenic potential of COPP chemotherapeutical protocol in "long term" experiments. Elevated expression of oncogenes was shown as soon as 24 hours after treatment in CBA/Ca inbred mice, in "short term" experiments. Now we present the results of the follow-up study dealing with the carcinogenic effect of COPP. The genes most frequently involved were N-ras and p53, with the thymus being the target organ of COPP.

Effect of different cytostatic protocols on oncogene expression in CBA/Ca mice.

In vivo investigations on oncogene action may provide new findings on the toxicology of potential carcinogens. In this study we investigated the early effects of different cytostatic protocols on early oncogene expression in CBA/Ca mice. Most of the examined protocols showed detectable early changes, especially those containing cyclophosphamide. The most frequently involved oncogenes were N-ras, c-myc, and c-myb.

Establishment and characterization of an EBNA-negative human lymphoma cell line (BHL-89).

BACKGROUND: The aim of the work was to establish human malignant lymphomas in culture, in order to study the biological characteristics and drug sensitivity of lymphomas of human lymphoid origin. MATERIALS AND METHODS: Lymph nodes of patients were explanted and kept in cultures using conventional tissue culture methods. Cytogenetic methods were used for karyotype analysis. Clonogenic assay was applied to test drug sensitivity. The tumorigenic capacity of the cells was determined by inoculating them into immunosuppressed mice. Immunological and other markers were examined with conventional techniques. RESULTS: A cell line, BHL-89, was established in culture from a patient with B-cell type non-Hodgkin's malignant lymphoma. Cells started to grow after a few days without a feeder layer in stationary suspension. The population doubling time was 48 h. The cells were hyperploid, and non-random aberrations were +1, -15, +14q+. Cloning efficiency in soft agar was found to be as high as 50-60%. The cells expressed markers characteristic of early B cells. The BHL-89 cells were Epstein-Barr nuclear antigen (EBNA) negative. They produced tumors when 10(7) cells were injected into immunosuppressed mice. The cells were sensitive to dibromodulcitol (Elobromol), an alkylating antitumor drug, and resistant to the phorbol ester TPA. CONCLUSIONS: The established EBNA-negative BHL-89 cell line has a few unique characteristics, e.g. rapid establishment without feeder cells, origin from the lymph node of an adult patient, high clonogenicity in soft agar, and resistance to TPA. The cell line is suitable for studying the nature of B lymphomas and testing compounds against lymphoproliferative disorders.

Carcinogenic effects of cytostatic protocols in CBA/Ca mice.

An in vivo mouse model was developed in order to study the characteristics of secondary tumor induction by cytostatic drug combinations used in human anticancer treatment. In this model we have proved the carcino-leukemogenic effects of widely used chemotherapeutical drug combinations (CHOP, COPP, COPBLAM, VAM). The carcinogenic hazards of cyclophosphamide and other alkylating drugs could also be demonstrated in our model.

Comparative studies on genotoxic and carcinogenic effects of different cytostatic protocols. I. In vivo cytogenetic analyses in CBA mice.

In vivo rodent cytogenetics may provide an important basis for an animal model for the assessment of the carcinogenic potential of antitumor drugs in man. In this paper, genotoxic alterations (i.e. sister chromatid exchanges and micronuclei) caused by different cytostatic protocols in CBA/Ca mice are described. The strongest sister chromatid exchange inducing effects were shown by the ABVD (doxorubicin-dacarbazine-bleomycinvinblastine) group and combinations containing cyclophosphamide. Compounds which affect the mitotic spindle induced only micronuclei, but not sister chromatid exchanges.

Cytochemical maturation index for the prognostication of adult acute nonlymphocytic leukaemia.

76 adult acute nonlymphocytic leukaemias (ANLL) were characterized by cytochemical markers and placed in a coordinate system. The position of each ANLL was determined on the basis of the peroxidase and nonspecific esterase reactivity of the blast cells. This classification numerically identifies the maturation tendency and heterogeneity of individual ANLL cases according to its position in the coordinate system. 49 ANLL patients were treated with TAD protocol and the response rate seemed to be in a conspicous correlation with the position of the individual ANLL cases in the modified arrangement. Cases exhibiting a strong peroxidase maturation, i.e. the cytochemical maturation index being 80% or more had a considerable higher complete remission rate and longer duration of remission than those with low (less than 80%) maturation index. Age profoundly influenced even this figure.

Studies on the vasoocclusive crisis of sickle cell disease IV. Mechanism of action of pentoxifylline (Trental).

Pentoxifylline was shown to prevent sickling induced by deoxygenation of SS-genotype blood from sickle cell disease patients. It also prevents development of cell stiffness, based on decreased membrane fluidity. This effect is related to increased red cell ATP content, decreased potassium loss during sickling and decreased attachment of hemoglobin to the red cell membrane during sickling. There was no effect on osmotic fragility or mean corpuscular volume. There was some increase in pH of blood from patients in vasoocclusive crisis of sickle cell disease under the effect of pentoxifylline. The consideration is discussed that pentoxifylline may prevent vasoocclusive crisis, but may not abort an existing process.

The relationship between sister chromatid exchange induction and leukemogenicity of different cytostatics.

The genotoxicity of frequently used cytostatic agents was characterized by the enumeration of the sister chromatid exchanges (SCEs) induced by them in vivo in phytohemagglutinin-stimulated peripheral blood lymphocytes. Fifty-nine cancer patients undergoing and off chemotherapy are included in this study. The aim was to identify cytostatics according to their ability to alter the SCE frequency. Cytostatics with strong SCE-inducing ability (melphalan, cyclophosphamide, cyclophosphamide + vincristine + 5-fluorouracil, cyclophosphamide + vincristine + procarbazid + prednisolone) usually exhibited a longlasting SCE elevation. Cytosine arabinoside, hydroxyurea, vincristine, 5-fluorouracil, tamoxifen, and azathioprine did not induce SCEs. These data were compared with the leukemogenic potential of the same drugs in order to validate the relevance of SCE studies in man to signal carcinogenic hazards. It was found that over 80% of all secondary leukemias (collected from the world literature from 1930 to 1980) were preceded by the administration of cytotoxic compounds inducing long-lasting SCE elevation in lymphocytes. Only 3% of all secondary leukemias can be attributed to drugs not inducing SCEs in vivo in PHA-stimulated lymphocytes. This indicates that the lesions important for SCEs and secondary leukemias to emerge bear close biological similarities. Thus SCE studies can be used in selecting therapeutical protocols or new cytostatics with less carcinogenic potential to man.

Characteristics of secondary acute nonlymphocytic leukemias. Cytological aspects (a review).

A register of 746 cases of secondary acute leukemias has been established by reviewing the literature from 1930-1980. Out of these 680 belong to acute nonlymphocytic leukemias, FAB M1-M6. Data have been subjected to a multiparameter analysis in term of previous therapy and subtype characteristics of acute nonlymphocytic leukemia (ANLL). There are indications that secondary ANLL are characterized by the preponderance of early acute myeloblastic leukemias if compared to de novo ones. Furthermore it has been shown that alkylating agents induced decidedly more acute myelomonocytic leukemias whereas irradiation tended to induce more acute myeloblastic leukemia. Since secondary acute leukemias represent a serious late consequence of alkylating agent and irradiation therapy it is high time to find new therapeutical modalities for lymphomas and to consider the withdrawal of alkylating agents from the therapy of autoimmune disorders.

Clastogenicity and sister chromatid exchange induction by ftorafur.

The main effect of Ftorafur at the chromosomal level is the induction of chromatid and chromosome breaks, which is some pronounced in neoplastic or transformed cells than in normal cells. Different cell lines used in the study exhibited both in vitro and in vivo varying sensitivity to Ftorafur. Ftorafur does not increase the frequency of SCE.