Human cells of neural origin are permissive for bovine leukemia virus.

Bovine leukemia virus (BLV) propagated in a cell clone of fetal lamb kidney origin was transmitted by cell contact to different mammalian cells including human cells. The transmission of the BLV genome was effectively achieved by cocultivation of mitomycin-C-killed, virus-producing cells of the cell clone with recipient cells. In particular, human cells of neural origin were highly susceptible to BLV infection, while some other cells were resistant. The transmission of the BVL genome from virus-nonproducing cells failed which suggests the existence of virus specific receptors on the cells. The donor cells contained three integrated BLV proviruses. In recipient cells only one provirus was found. The majority of cells contained both unintegrated and integrated BLV provirus. In the cells containing the transmitted BLV, the viral genome was expressed to its protein products. The results indirectly suggest that retroviruses with similar properties could cause various neural diseases in man.

Primary and transplantable hepatomas induced by aflatoxin B1 in hypothyroid rats.

The influence of hypothyroidism on AFB1 carcinogenesis in inbred Wistar rats was studied. The primary AFB1 hepatocarcinogenesis was significantly delayed and reduced. The transplantable hepatomas showed prolonged latency periods in rats of both sexes, and in males decreased tumor weights and a lower number of lung metastases were observed. The level of GGTP in serum and liver paralleled the advancement of morphological hepatic lesions, and the activity of serum GGTP in hypothyroid bearers of the transplantable hepatoma was lower in females than in males. It was concluded that the lack of thyroid hormones during the latency period of primary and transplantable hepatomas is decisive for delayed AFB1 carcinogenesis.

Complex biochemical analysis of human breast tumor tissue.

The quantitative biochemical analysis of tissue specimens from 76 human breast carcinomas consisted of examination for cytosolic estrogen receptors (cER), nuclear estrogen receptors (nER), progesterone receptors (PgR), 1,25-dihydroxycholecalciferol receptors (DR), carcinoembryonic antigen (CEA), alpha-lactalbumin (aLA), and gamma-glutamyl transferase (gGT). The highest incidence was found in CEA (76%), DR (70%), and aLA (62%). There was a high percentage of tumors containing only DR, in contrast to the tumors containing only cER or PgR. The simultaneous occurrence of DR and CEA was considerably high (61%). No statistically significant differences were observed in these biochemical parameters in relation to the grade of differentiation of the tumors. The values of aLA in tumors that invaded lymphatic or blood vessels were lower as compared to those tumors that invaded adipose or connective tissues. The level of statistical significance of this difference was close to 5%, the differences in other parameters were statistically insignificant. For prognosis assessed at the time of surgery, after a 2-3-year follow-up of 36 patients the level of gGT in the tumor seems to be the most promising prognostic factor. The values of gGT were significantly lower in those patients whose tumors were in progression during this time. The significance of nER and aLA was also taken into consideration.

Monoclonal antibodies (series Bra-) of broad (non-lineage) or restricted (myelomonocytic) reactivities elicited with granulocytes or K 562 cells.

A series of monoclonal antibodies was obtained by hybridoma technology after immunization with granulocytes from healthy donors or K 562 immature erythroid-myeloid leukemia cells. Three different types of reactivities with examined hematopoietic-, nonhematopoietic cells and cell lines were observed by microscopic immunofluorescence, immunocytofluorometry and enzyme-linked immunoassay (ELISA), as follows: (i) broad, non-lineage type of two monoclonal antibodies (Bra10G and Bra7F1) with examined hematopoietic and nonhematopoietic human neoplastic cell lines, (ii) non-lineage type of reactivity restricted to hematopoietic cell lines, and (iii) restricted (myelomonocytic) pattern of binding to myeloid cell lines and healthy donors' granulocytes (monoclonal antibodies Bra4F1, BraC8 and Bra1F2). Monoclonal antibodies Bra10G and BraC6 were shown to immunoprecipitate specifically a heterodimeric two-chain cell surface protein p200,95 from cell lysates of lactoperoxidase radioiodinated U 937 cells with recognized epitope localized on the heavy chain (as shown by immunoblotting experiments). Antibodies with restricted myelomonocytic type of reactivity exhibited minor quantitative differences in their microscopic immunofluorescence and immunocytofluorometric patterns of reactivities with examined myeloid leukemia cell lines (K 562, HL 60, U 937) and healthy donors' granulocytes. The monoclonal antibody Bra4F1 was defined by the 4th International Workshop on Leukocyte Differentiation Antigens as CD15 (with typical selective reactivity towards myelomonocytic leukemia cells and cell lines as well as healthy donors' granulocytes) recognizing the X-hapten carbohydrate antigenic determinant.

Antitumor activity and cross-resistance studies with Pt-ascorbato complexes.

Two ascorbatoplatinum complexes, cis-diammineascorbatoplatinum(II) (AMA) and cis-bis(ascorbato)-trans-diaminocyclohexaneplatinum(II) (CHA), were tested for antitumor activity in vivo on P388 leukemia and in vitro in suspension culture and soft agar assay. Sensitive line of L1210 and sublines with resistance induced against cis-diamminedichloroplatinum(II) (DDP) and two derivatives of trans-1,2-diaminocyclohexane (DACH) were used for the in vitro tests. DNA synthesis inhibition in both sensitive and resistant cells was tested. The results are compared with DDP and DACH-Pt(II)-4-carboxyphtalate (TMA). Both tested complexes proved their antitumor activity in our experimental systems. The CHA complex was more effective than AMA and its effectiveness is comparable with that of DDP and TMA. Cross-resistance was found between DDP and AMA as well as TMA and CHA. There was no cross-resistance between DDP versus CHA, and TMA versus AMA.

Changes of lipid-bound sialic acid in the plasma of mice bearing benzpyrene-induced tumors.

The level of lipid-bound sialic acid (LSA) was followed in inbred C57Bl/6 mice bearing tumors induced by benzpyrene at a dose of 20 mg per kg of body weight. In the plasma of mice with macroscopically ascertained tumors, the level of LSA was increased significantly. The LSA level was also significantly increased in the plasma of suspect mice i.e., in a period when the tumor was not yet macroscopically ascertained, however, when a change was observed in the motion of the hind limb of mice to which benzpyrene was administered.

Adriamycin response of two human tumor xenografts using a double-radiolabel organ culture method.

A double-radiolabel method of quantitating drug response in a simple organ culture system was used to study the effects of adriamycin on two human tumor xenografts in vitro. Explants of X56, an adenocarcinoma of colon, and HXG2, an amelanotic melanoma, both maintained by serial transplantation in athymic mice, were sequentially incubated in vitro with 14C-thymidine, one of several concentrations of adriamycin, and then 3H-thymidine. The ratios of second to first radiolabel incorporation declined as a function of adriamycin concentration. HXG2 was significantly more responsive to adriamycin than X56 in the double-radiolabeled assay. Greater sensitivity of HXG2 was confirmed by three additional methods: The human tumor stem cell assay (HTSCA), chemotherapy trials in tumor-bearing athymic mice, and a double-radiolabel protocol in vivo in tumor-bearing athymic mice. An organ culture method of this type may be useful in screening individual patients' tumors for drug resistance.

Is isochromosome i(12p) present in gonadal precancerous tissue?

The development of frequent gonadal tumors in some syndromes of abnormal sexual differentiation is often preceded by carcinoma in situ. To detect possible early changes in chromosome number and/or structure associated with the carcinoma in situ, gonadal tissue was studied in one patient with the complete form of testicular feminization syndrome, two patients with the incomplete form of this syndrome, and one patient with Swyer's syndrome. In all patients aneuploidy with a bimodal distribution of chromosome numbers with the peaks at diploid and near-tetraploid values was shown. The possible specific chromosomal marker of gonadal tumors, isochromosome i(12p), has not been found. Its absence suggests that this marker might be associated with more advanced stages of long-term cancer development or it could be confined only to a subgroup of testicular tumors, as was proposed earlier. The hypothesis that the major source of hypotetraploid or near-triploid cells often found in many gonadal tumors might be endoreduplications with their subsequent chromosome loss is supported.

Natural killer activity and NK cytotoxic factors in peripheral blood and lymph node cells from non-Hodgkin's lymphoma patients.

Natural killer (NK) activity and natural killer cytotoxic factors (NKCF) were found to be depressed in large granular lymphocytes (LGL) from the peripheral blood and lymph node lymphocytes (LNL) from untreated non-Hodgkin's lymphoma (NHL) patients. The LGL number was also reduced in NHL patients as compared to the normal subjects. The depression in all the activities mentioned above showed a correlation with the clinical status of the patients. Exogenous interferon-alpha (IFN-alpha) treatment of the effector cells could augment the NK activity to a comparable extent in normal as well as patient's LNL. The results indicate that the production of interferon may be affected in cases of NHL and therefore it would be worthwhile to test the tolerance and efficacy of IFN-alpha in these patients.

Treatment of advanced Hodgkin's disease with modified MOPP regimens. A long-term observation.

Fifty-three patients with advanced Hodgkin's disease, most of them previously treated, received 8 to 16 courses of modified MOPP regimens (nitrogen mustard replaced by trichlormethine in arm A, with addition of vinblastine to the 4-drug regimen in arm B, and alternation of three drugs--trichlormethine, vincristine, and prednisone--with probably non-cross resistant two drugs--vinblastine and procarbazine in arm C). Thirty patients (57%) achieved complete remission. Higher complete remission rate and longer survival was recorded in patients treated with 5-drug regimens (arms B and C) as compared to the 4-drug regimen (arm A), but the differences were not significant. Higher complete remission rates were observed in asymptomatic patients, females, and patients with lymphocyte predominance and nodular sclerosis subtypes of Hodgkin's disease. Besides expected short-term toxicity, 4 out of 30 complete responders developed secondary malignancies (two acute myeloblastic leukemias, one hepatocellular carcinoma, and one cerebellar astrocytoma). Several other patients had serious toxicity which could be attributed to chemotherapy. Twenty-eight percent of the patients has been alive 15 to 18 years since the start of this study.

Clinical features of Hodgkin's disease in Cuba and Sweden.

A clinical study of 182 Swedish and 164 Cuban consecutive adult patients with Hodgkin's disease was performed comparing age, sex, histopathology, clinical stage, symptoms, and various laboratory tests. A bimodal age distribution was observed which was more pronounced in the Swedish series. A male/female ratio 1.8/1.0 in both samples was observed. Nodular sclerosis and Stage IA and IIA were more common in Swedish patients while in the Cuban, mixed cellularity and Stage IIIB and IVB dominated in patients below fifty years of age. The Swedish patients exhibited an age distribution similar to that found in other industrialized Western countries, while the Cuban patients had an age distribution pattern typical for countries with an intermediate epidemiological pattern.

Interstitial radiotherapy of malignant tumors of the vagina.

A total of 65 patients with malignant tumors of the vagina aged 32-81 years were treated by interstitial radiotherapy. Out of the 65 subjects, 52 patients were irradiated with 60Co sources, and 13 patients with 252Cf sources. Fixing devices of three types were used which ensured the practical realization of interstitial radiotherapy in regard to tumor localization, its shape, and volume. Complete tumor regression occurred in 54 patients (83.1%) and partial regression was observed in 9 patients (13.8%). Mild radiation reactions were found in 17 patients (26.1%). No effect was observed in 2 patients (3.1%). In one case necrotic radiation ulcer developed. On the basis of the above data the conclusion was drawn that interstitial radiotherapy represents the treatment of choice in malignant tumors of the vagina.

Effect of oxoplatinum and CBDCA on renal functions in rats.

Changes in renal function in rats after single-dose intravenous administration of CBDCA (cis-diammine-1,1-cyclobutane dicarboxylate platinum(II) and oxoplatinum [cis-dichlorodiammine-trans-dihydroxo-platinum(IV)] at a dose of 20 mg/kg were determined and compared. Renal function was monitored by several determinations of effective renal plasma flow (ERPF), glomerular filtration rate (GRF), plasma creatinine and urea and urine beta 2-microglobulin. A significant reduction of ERPF and GRF and a significant increase of plasma creatinine and urea concentration after oxoplatinum treatment were found. On the other hand, no significant changes in renal function parameters were determined after CBDCA. The increase in beta 2-microglobulin amount in rat urine and polyuria persisted until the 14th day after oxoplatinum administration. Histological examination of the kidneys in the experimental animals revealed marked nephrotoxicity changes in the distal tubules after the single-dose administration of oxoplatinum. Administration of CBDCA did not produce pathological renal changes.

Substances with antineoplastic activity. XCVI. Some pharmacological properties and therapeutic synergism of 6-purinyl-N-(2-chloroethyl)thiocarbamate with cytosine arabinoside.

The cancerostatic effect of 6-purinyl-N-(2-chloroethyl)thiocarbamate (Cloturin VUFB, VUFB-15686) was studied in detail in mice and rats bearing transplantable tumors. The cytotoxic activities were measured by determining the incorporation rate of 5-iodo-2'-deoxy[6-3H]uridine and uniformly labeled [U-14C]amino acid mixture into trichloroacetic acid-insoluble fraction of Yoshida ascites reticulosarcoma cells during a short-term incubation with the drug. From the results obtained it follows that the new substance is therapeutically more effective in comparison with 6-mercaptopurine (NSC-755). A therapeutic synergism of Cloturin with cytosine arabinoside (NSC-63978) was observed.

Expression of p21 ras protein in human melanoma cell lines.

Samples obtained from six human melanoma cell lines have been tested for the presence of p21 ras oncogene product by Western blotting analysis. The overexpression of p21 was detected in two cell lines out of the six samples. These DNA samples have not been shown to be transformants by transfection assay. Moreover, amplification or rearrangement of DNAs from these cell lines was not found by Southern blotting analysis. Northern blotting analysis, however, detected the expression of Ki-ras gene in RNA extracted from the two cell lines. Thus, it was suggested that the overexpression of p21 might be a result of increased normal mRNA transcript of Ki-ras gene.

Phenotypical study of human lymphokine-activated killer (LAK) cells.

In the present study, T-cell enriched lymphocyte populations were stimulated with recombinant interleukin-2 (IL-2) to obtain lymphokine-activated killer (LAK) cells, and their cytotoxicity was tested against different target cells. The expression of phenotypical markers with a panel of monoclonal antibodies (Moabs) using indirect immunofluorescence techniques and cytofluorometric analysis was studied. The results showed slight variations in T-cell antigen expression and an increase in the expression of immature NK and proliferation associated antigens.

The effect of platinum cytostatics on delayed-type hypersensitivity in mice.

The effect of cisplatin, carboplatin, oxoplatin, and iproplatin on delayed-type hypersensitivity in mice was studied. Comparing the equitoxic doses, which were close to therapeutic dosages, we found a greater inhibition of delayed-type hypersensitivity in the second-generation platinum complexes than in cisplatin. This inhibition occurred mainly when these drugs were applied after sensitization. This phenomenon might be explained by the antimitotic action of platinum cytostatics. The lower toxicity of second-generation platinum drugs was not accompanied by a corresponding decrease of immunotoxicity.

Mediastinal teratoma and acute megakaryoblastic leukemia.

The association between mediastinal teratoma and acute megakaryoblastic leukemia (AMKL) in a 15-year-old boy is described. The clinical course is compared with 20 previously reported cases of AMKL in children. Chromosome studies at diagnosis of the leukemia showed multiple leukemic stem lines with numerical and structural abnormalities.

Circulating immune complexes in acute leukemia.

Circulating immune complexes (CIC) were measured at the time of diagnosis in 81 patients with acute leukemia or blast crisis of chronic myeloid leukemia using precipitation by 3.75% polyethyleneglycol. Elevated CIC levels did not adversely influence complete remission duration and survival, patients with normal CIC levels exhibited mostly shorter remission and survival than those with elevated or borderline levels. No significant correlation was observed between CIC levels and Hb, WBC, CBC, platelet count, age, serum bilirubin, total protein, fibrinogen, AST and ALT levels, presence of hepatosplenomegaly and/or lymphadenopathy, HbSAg positivity, complete remission duration and survival. The lack of correlation may be caused by altered immune response in leukemic patients, but the obtained results may also be affected by the nonspecific nature of the method used for the detection. Simultaneous detection of CIC levels by multiple tests and evaluation not only of the number but also of the composition and size of CIC may decrease the incidence of false results. Nevertheless, only the establishment of antigen-specific assays may resolve the controversies in the detection of CIC and thus contribute to a more precise assessment of the role of CIC in prognosis of cancer, as well as to the verification of reliability of using CIC as a tumor marker.

Enhanced take of spontaneous murine tumors in mice treated with inhibitors of macrophage and/or NK cell function.

Both macrophages and NK cells have been suggested to play a role in recognizing and eliminating early, in situ neoplasms. Therefore we studied the effect of inhibitors of macrophage and/or NK cell function on the take of transplantable spontaneous murine tumors in syngeneic mice. The treatment of animals with trypan blue, a selective inhibitor of macrophage function, decreased considerably the period of latency of BSP3 adenocarcinoma; however, it did not increase the take of SP4, SP82 and SP84 adenocarcinomas. The treatment of recipients with neutral red, a selective inhibitor of NK cell function, enhanced the take of SP4 adenocarcinoma. The treatment of mice with agents depressing both macrophage and NK cell function (silica or carrageenan) decreased the both macrophage and NK cell function (silica or carrageenan) decreased the period of latency and/or increased the take of SP4, SP82 and SP84 adenocarcinomas. Carrageenan or a combined treatment with both trypan blue and neutral red also enhanced the take of BaF1, a benzo(a)pyrene-induced fibrosarcoma. We concluded that both macrophages and NK cells may function as effector cells of an antitumoral surveillance system.

Cathepsin B in human breast tumor tissue and cancer cells.

The cysteine proteinase cathepsin B (EC 3.4.22.1) has been proposed to play an important role in the proteolytic mechanism of the ability of breast cancer cells to invade into and through normal tissues during metastasis. In this study, activity of cathepsin B was measured with a fluorometric microtiter plate assay in human breast tumors as well as in mammary gland dysplasias and in four human breast cancer cell lines (BT-20, MDA-MB-231, PMC42 and T47D). It was found that primary breast carcinomas and cystosarcomas phyllodes contain significantly higher levels of cathepsin B activity than mammary dysplasias; the activity of cathepsin B in cystosarcomas phyllodes was comparable with that in breast carcinomas. The enzyme from breast carcinoma tissue exhibited properties of a mature form of cathepsin B. All investigated breast cancer cell lines display positive cytochemical staining for cathepsin B activity with granular pattern of distribution of the final reaction product. Biochemically, the breast cancer cell lines differed significantly from each other in the level of cathepsin B activity decreasing in the following order: T47D, PMC42, MDA-MB-231 and BT-20.

Cytogenetic analysis of metastatic effusions from breast tumors.

Chromosome analysis was performed on direct and in vitro cultures of 30 effusions from breast carcinoma. Although in 14 samples normal diploid stem-lines were found, chromosome abnormalities were present in stem- or side-lines of all cases. Recurrent numerical deviations were only verified as gains of Nos. 6 and 7. Rearrangements were seen involving almost all chromosome pairs (except No. 18 and gonosomes), however, Nos. 1, 3, 6 and 11 were those most frequently related to the genesis of markers. Double minutes (DMs) were found in seven samples, and there was a homogeneously staining region (HSR) in one.

Inhibitor of normal granulopoiesis produced by cells of MDS patients.

Low-density blood cells from patients with refractory anemia with excess of blasts (RAEB) and RAEB in transformation (RAEB-T) release a high molecular weight inhibitory substance that reduces the entry of normal progenitor cells of granulocytes and macrophages (CFU-GM) into the S-phase. Out of 20 patients with refractory anemia (RA and RAS) only 3 were positive. One patient with CMML was negative. Serial examination of 3 patients (two RA and one CMML) revealed that the production of the inhibitory activity preceded the development of the disease into RAEB, RAEB-T, or AML. With one exception, the inhibitory activity in positive cases was neutralized by antiserum against human placental ferritin.

Primary screening and inhibition of macromolecular biosynthesis by benfluron metabolites in vitro.

Cytotoxicity and mechanisms of action of 2 metabolites of benfluron (BF), namely 7-dihydrobenfluron (DBF) and benfluron N-oxide (NOBF) were tested. Cytotoxicity in the primary biochemical screening was measured by the inhibition of 14C-adenine and 14C-valine incorporation into the TCA-insoluble fraction of Ehrlich ascites carcinoma (EAC) cells under defined in vitro conditions. Both metabolites were found to have cytotoxic effects, with NOBF being more active than DBF. Further we investigated the kinetics of incorporation not only of adenine and valine, but also of 14C-thymidine and 14C-uridine both into Ehrlich carcinoma cells and into P388 leukemia cells.

Induction of gastric cancer in monkeys by N-methyl-N-nitro-N-nitrosoguanidine (MNNG).

N-methyl-N-nitro-N-nitrosoguanidine (MNNG) was administered to 9 Macaca fascicularis monkeys (7 males and 2 females) through a tube at a dose of 40 mg/kg body weight 3 times a month. Tumors of the pyloric part of the stomach were observed in 2 male monkeys after MNNG doses of 800 and 848 mg/kg body weight, with a latent period of tumor development of 49 and 50 weeks, respectively. Histologically, in one case the tumor was a solid carcinoma, and in the other it had a mixed structure showing alternating solid and signet ring cell carcinoma areas.

In vivo autofluorescence investigations on animal tumors.

The in vivo fluorescence behavior of unmarked tissue (autofluorescence) of tumor-bearing mice was investigated. An argon-ion laser was used as the excitation source emitting radiation at 351 nm and 364 nn. Fluorescence bands in the red spectral range were recorded. The spectral distribution of the fluorescence of the solid Ehrlich carcinoma was different from that of the neighboring tissue.

Osmotic fragility, sialic acid content and survival of circulating erythrocytes in anemic tumor-bearing mice.

Effect of tumor growth on the survival of circulating erythrocytes was studied in mice bearing a wide spectrum of experimental tumors. RBC half-life (t1/2), measured by 51Cr-labeling technique, decreased significantly (p less than 0.05) in all the tumor types studied, particularly in transplantable Sarcoma-180 and benzo(a)pyrene-induced primary fibrosarcoma. Changes in erythrocyte morphology like anisopoikilocytosis were also observed in the tumor hosts. Cross-transfusion of 51Cr-labeled RBCs between normal and tumor-bearing animals revealed that both intrinsic and extrinsic factors are responsible for shortened RBC survival. As far as the cellular abnormalities are concerned, the decrease in RBC t1/2 was not attributable to increased osmotic fragility as the cells were observed to be osmotically more resistant. Similarly, membrane sialic acid content was markedly elevated in the tumor hosts, thus the shortened erythrocyte life-span cannot be attributed to decrease in sialic acid content of the erythrocyte membrane.

Effect of cisplatin on con A agglutinability of different lymphoid cells of Swiss albino rats.

Thymocytes, splenocytes, and lymph node cells showed a differential degree of agglutination which con A, which was the lowest for thymocytes and the highest for lymph node cells. Cisplatin treatment of the cells showed a gradual increase and then decrease in the degree of agglutination of the cells which varied with cisplatin concentration and time of treatment. The cells treated with 20 micrograms/ml of cisplatin for 30 min showed the maximum increase in the degree of con A agglutination. Incubation of these cisplatin-treated cells with D-xylose, D-glucose, or sialic acid before con A agglutination showed a decrease in the cell agglutinability which was the lowest for sialic acid-incubated cells. It is suggested that the removal of cell surface carbohydrate moieties after cisplatin treatment may play a role in the changes in con A agglutination of these cells.

Blood coagulation changes in rats during development of epithelioma.

Coagulation activity in the blood of rats during the development of Guerin epithelioma was studied. Clotting time, level of fibrinogen and some coagulation factors (II, V, VII + X) in the plasma were determined and thromboelastographic studies were performed. Two periods of blood hypercoagulability were observed in the process of epithelioma development. The first a short-term period, was noticed during the first days following the implantation of the neoplastic tissue. The second took place during the intensive growth of the primary tumor and metastases.

Retrovirus-neutralizing antibodies in AML and AMMoL patients: stage-specific distribution.

Plasma samples of patients with AML or AMMoL were tested for antibodies reacting with gp70 antigens of BaEV and GaLV as well as for antibodies neutralizing BaEV or GaLV. Both frequency and titer values of antibodies were higher in remission than in blastosis. Neutralizing activity could be detected only in those plasma samples which contained antibodies to the appropriate gp70 antigen. The data suggest the presence of retroviruses in humans as antigenic stimuli for the immune system in AML and AMMoL.