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Abstract Background Plasma transforming growth factor β1 (TGFβ1 ) levels are elevated in patients with lung cancer. As TGFβ1 is mainly found in platelets and as nonmalignant pulmonary diseases (NMPD) are frequently associated with lung cancer, we investigated the potential contribution of platelet degranulation and/or of a concomitant NMPD to the increased plasma levels of TGFβ1 reported in patients with lung cancer. Materials and Methods Blood samples were collected in duplicate from 30 healthy subjects, 14 patients suffering from NMPD and 37 patients with lung cancer. The platelet count was determined and the samples were processed to obtain plasma. One sample was collected in EDTA (EDTA plasma) and the other in a mixture inhibiting platelet degranulation (PIM plasma). TGFβ1 concentrations and β-thromboglobulin (βTG) levels, an index of platelet degranulation, were measured in both plasma samples. Results TGFβ1 and βTG plasma levels measured in PIM plasma were lower than those obtained in EDTA plasma. With respect to PIM plasma, both TGFβ1 and βTG levels were higher in patients with lung cancer than those with NMPD and in healthy individuals. In patients with NMPD, only TGFβ1 levels were increased as compared to healthy controls, βTG levels being similar. Conclusion Methods for collecting and processing blood samples are critical in determining reliable circulating TGFβ1 levels. Increased TGFβ1 plasma levels observed in patients with lung cancer are related, at least partly, to concomitant NMPD and also to platelet degranulation as proved by increased βTG levels. [ABSTRACT FROM AUTHOR]

The intracellular distribution of thymidine phosphorylating kinases has been studied ill rat liver at different times after partial hepatectomy. After conventional fractionation in 0.25 M sucrose, thymidine kinase is present in all fractions, the highest proportion being found, however, in the supernatant; phosphorylation of thymidine to TDP and TTP is detected only in the supernatant fraction from 24 h onwards after hepatectomy. Nuclei prepared in 2.2 M sucrose or in non-aqueous media have the same level of thymidine kinase activity and can never phosphorylate thymidine to TDP and TTP. In the nuclear fractions, the absolute activity of thymidine kinase increases from 16 to 46 h after hepatectomy but represents a decreasing proportion of the activity of the homogenate. At the same time, the proportion of kinase activity rises markedly in the supernatant fraction with a maximum of 83% in 40 h regenerating livers. The implications of these results are discussed. [ABSTRACT FROM AUTHOR]

The kinetics of incorporation of labelled precursors into the DNA of isolated rat liver mitochondria has been studied after X-irradiation in vitro. Incorporation ofH-TTP was slightly inhibited during the initial period, followed by an increase of about 25 % of the specific activity. Incorporations ofH-TdR andH-BUdR were also stimulated by irradiation of mitochondria, although the amount of incorporated precursor was lower than that ofH-TTP. This radiation-induced incorporation of precursors was abolished by the addition of ethidium bromide or EDTA. Degradation of mt-DNA, indicated by the decrease of specific radioactivity, was observed after irradiation of pre-labelled mitochondria; in presence of EDTA the degradation was not detected. These results were discussed from the viewpoint of the repair synthesis of mitochondrial DNA. [ABSTRACT FROM AUTHOR]

Incorporation of thymidine into nuclear and mitochondrial DNA has been measured in the livers of normal rats and of rats killed 17 h or 24 h after partial hepatectomy. When total-body X-irradiation (500 or 1,500 R) is given at increasing intervals (up to 30 h) before sacrifice, a progressive decrease followed by a plateau of low level of incorporation is observed in the nuclear DNA (N-DNA) whereas the synthesis of mitochondrial DNA (M-DNA) first decreases until a minimal value is reached after 4 h in normal liver and 12 h in regenerating liver, then recovers at an exponential rate, quite independently of the nuclear DNA synthesis. The results suggest that irradiation can interfere with the enzymatic processes of both M-DNA and N-DNA syntheses, but that the persistence of the inhibition of N-DNA synthesis must be ascribed to a temporary block in the cell cycle. The SH-protector AET injected to non-irradiated rats exerts a very small inhibitory effect on normal liver N-DNA and M-DNA synthesis. In regenerating liver, both syntheses are affected rather similarly suggesting a common mechanism of inhibition through impairment of some step in the synthetic process. [ABSTRACT FROM AUTHOR]

The activation of the p34cdc2/cyclin B complex is responsible for driving the cell cycle from the G2- to the M-phase. To investigate the effects of irradiation on the activity of the p34cdc2/cyclin B complex in preimplantation embryos, we irradiated one-cell mouse embryos with 2.5 Gy of X-rays at the early pronuclear stage, and measured the fluctuations of histone H1 kinase activity (a biochemical indicator of the kinase activity of the p34cdc2) at different times during the radiation-induced G2-arrest. BALB/c embryos were chosen for these experiments, since earlier results obtained in our laboratory had shown that such a treatment induces a G2-arrest of about 20 hours in more than 90% of the embryos. Our data showed that histone H1 kinase activity of irradiated embryos remained at a very low level during the period of G2-arrest. The level of activity found during late division of the G2-arrested embryos was also significantly lower in comparison with that of control embryos or irradiated embryos dividing without delay. All together, our results suggest that a) low levels of histone H1 kinase activity are sufficient for the division of one-cell embryos, b) there could be a link between the levels of histone H1 kinase activity in mitosis and the health status of the embryo.

Forty patients with intermediate stage (T2 > 3 cm-T3, N0-N1) operable breast cancer received neoadjuvant chemotherapy by MCF (mitoxantrone, cyclophosphamide, 5-fluorouracil). Four cycles were administered at 3-week intervals. The obvious hematological toxicity (64% of grade III for the leucocytes and up to 34% of grade IV for the granulocytes) was rapidly reversible and did not hinder completion of the treatment. Ten patients showed a complete remission and a tumor volume regression of more than 50% was observed in 12 other patients. Tumor shrinkage allowed breast-saving surgery in 50% of the cases. A complete sterilisation of the surgical specimen was found in only two of the 40 patients and a few persisting neoplastic cells were found in ten other cases. A positive response at the level of the axillary lymph nodes was also obtained in more than 50% of the cases. In 25 of the 36 cases examined, the primary chemotherapy induced cellular lesions (fibrosis, necrosis) at the tumor level. A feasibility study was undertaken in order to determine quantitatively several biochemical parameters (steroid hormone receptors, cathepsin D, c-erbB-2 oncoprotein) in very small tumor samples obtained by Tru-Cut before any treatment and in surgical specimens. In the future, these micromethods will be used systematically with the aim of estimating the value of these potential prognostic factors for therapeutic follow-up of the patients.

Epidermal growth factor receptors (EGF-R) have been measured in human tumors of the Central Nervous System (CNS) by 125I EGF ligand binding. High affinity receptors (Ka congruent to 1 x 10(9) M-1) were detected in nearly all individual specimens of meningiomas and tumors of glial origin (astrocytomas, glioblastomas). The phosphotyrosine kinase activity associated with the EGF-R was evaluated by measuring the incorporation of gamma 32P-ATP, after immunoprecipitation of the receptor with the monoclonal antibody EGFRI. A good relationship was observed between the EGF-binding capacity and the autophosphorylation of the receptor, indicating that in most cases functional molecules of EGF-R were expressed on the tumor membranes. In the group of meningiomas, no relationship could be established between the EGF-R level and the histopathology of the tumors. Astrocytomas exemplify a progression of malignancy, from benign (low grade astrocytomas) towards an increased malignant phenotype (glioblastomas). In this group, our observations indicate a positive relationship between the EGF-R level and phosphokinase activity and the degree of malignancy.

The aim of the present experiments was to evaluate the relative biological effectiveness (RBE) of monoenergetic 2.5 MeV neutrons, in view of the scarcity of data on the RBE of neutrons in this energy range. Human peripheral blood lymphocytes from two donors were exposed to doses of neutrons ranging from 0.005 Gy to 0.5 Gy. Gamma rays produced by a telecobalt therapy unit were used as reference radiation. RBE values were of the same order of magnitude, whatever was the model of the dose-response curve chosen for the neutrons (linear or linear-quadratic). As expected, RBE increased markedly with decreasing doses and went beyond 30 at a dose level of 0.2 Gy. The present results, compared with RBE values obtained with neutrons of higher energy (6.5, 14 and 21 MeV), confirm that low energy neutrons are more effective in producing genetic effects, especially at low doses.

The yield of dicentric chromosomes has been recorded in peripheral blood lymphocytes of patients undergoing telecobalt therapy for glioblastoma. Blood samples were taken by venipuncture, prior to the first radiotherapy session and 24 h after 10, 20 and 30 Gy to the tumor volume. On the basis of the maximum likelihood method, the yield of chromosome aberrations was best fitted by a linear quadratic dose-response relationship. According to this relationship, the dose inducing ten dicentrics at the target volume is 58 Gy, a value considerably higher than those found after radiotherapy for mammary carcinoma (15 Gy) or for pelvic tumors (5.62 Gy). Our results indicate that, in the case of fractionated exposures, confined to a small volume of the body, it is not possible to estimate the total dose administered and that the method only provides an estimate of the proportion of the lymphocytes irradiated.

Either a Slow (SL) or Early (EL) type of leukemia are respectively induced in rats by the RadLV-Rs derived BL/F (SL) and BL/F (EL) viral populations. The kinetics of virus propagation was studied comparatively in the thymus, spleen, lymph nodes and bone marrow of rats infected either with BL/F (EL) or BL/F (SL). During the first days after inoculation with BL/F (SL), the viral population increased rapidly in all tissues, reaching a peak at day 8 to 10, except in the lymph nodes which were almost devoid of viral particles. A very different pattern was shown by the EL leukemia, indicating the importance of the early distribution of viruses amongst the lymphoid tissues in view of the further development of the disease. The large amount of viruses observed inside the megakaryocytes and budding from these cells confirm that they play a role in the leukemogenesis.

Two viral populations BL/F (EL) and BL/F (SL) were derived from RadLV-Rs by propagation in rats where they induced respectively a generalized lymphoma in 5-6 weeks or a thymic lymphoma killing the animals in 5-6 months. In both cases, 10 days after inoculation of viral extract, numerous viral particles are present in the megakaryocytes (MKC) of the bone marrow and the spleen. Our results suggested a production rather than a passive accumulation of those particles by the MKC. The kinetics of blood platelet level for both leukemias showed a thrombocytopenia corresponding with the macroscopic development of the tumor. Therefore the evolution of the blood platelet level is not related to the MKC viremia. This suggests a lack of direct effect of virus BL/F on the MKC metabolism.

Enhanced nucleocytoplasmic RNA transport has been demonstrated by incubating normal rat liver nuclei in presence of cytosols originating from the poorly differentiated, fast-growing hepatoma HW-165, in the linear phase of tumor growth. The effect of hepatoma HW-165 cytosol was reduced or suppressed in presence of small amounts of normal liver cytosol: on the other hand, several polypeptides of molecular weight 20,000 to 40,000 daltons were hardly detectable in hepatoma HW-165 cytosol, both arguments indicating that potentially regulatory proteins should be absent or present in reduced concentration in hepatoma HW-165 cytosol. No modification of RNA release was observed in presence of cytosols originating from the thymus of RNA virus (BL/F)-infected rats, whatever be the time after inoculation. Attempts were made to use the nuclear restriction assay, supplemented with plasma or serum of various origins, as a biochemical marker of neoplasia. In a first series of assays, including 80 cancer patients and 12 healthy controls, the RNA transport activity was stimulated by the serum of patients bearing various tumors (lung cancer, cancer of the respiratory tract, uterine cervix...), except in a few cases of mammary carcinoma, where values equivalent to or lower than the controls were obtained.

Two distinct leukemogenic viral subpopulations, BL/F (EL) and BL/F (SL) were derived from RadLV-Rs by propagation in rats. They were purified from the serum and studied by thin section and negative stain electron microscopy. Their ultrastructural organizations were not found to differ significantly from each other or from other murine leukemia viruses for which a detailed model now exists. Our work constitutes to our knowledge a first indepth study of viruses associated with radiation leukemia. It confirms the MuLV model built hitherto exclusively on observations from in vitro grown viruses.

Mouse zygotes (BALB/c) blocked in the G2 phase of the first cell cycle after X-irradiation were allowed to develop in culture medium. Delayed cleavage occurred at the same time in embryos exposed to 1 or 2 Gy and late division coincided with the second division in controls. Two-dimensional electrophoresis showed that blocked irradiated embryos underwent the same modifications in protein synthesis as control embryos of the same age, except during first mitosis, for three polypeptide sets of 30, 35 and 45 kilodaltons molecular weight. The most remarkable difference between them was the appearance in cleaving controls of three spots at 35 kilodaltons that were absent in blocked irradiated embryos. It is assumed that blocked embryos 'missed' some signal necessary for cell division, but remained ready to cleave when a second signal occurred. Eggs from the BALB/c strain were particularly susceptible to this effect of X-irradiation but it was also found in eggs from other strains, irradiated with much higher doses.

Despite extensive epidemiological and biochemical studies, the effects of a thyroid dysfunction on the incidence and progress of human cancer have been, for many years, a controversial subject. Endocrine manipulations on laboratory animals clearly demonstrate the influence of thyroid hormones on the induction and growth of several types of experimental tumors: lymphomas, mammary tumors, primary or transplanted hepatomas. In vitro, triiodothyronine also plays an early and critical role in the neoplastic transformation of cultured cells by X-rays, chemical carcinogens and RNA- and DNA-viruses. At the molecular level, the effects of thyroid hormones on the alterations of gene expression accompanying neoplasms remain unknown. Yet, the presence of nuclear triiodothyronine receptors in experimental and human tumors and the recent discovery, by several authors, that the cellular counterpart of a viral oncogene (v-erb A) encodes a thyroid hormone receptor, suggest: either a direct influence of the hormone on the initiation and/or the progress of these tumors; or an indirect effect, via the modulation of another metabolic regulator, for example a polypeptide growth factor (Epidermal Growth Factor, Transforming Growth Factor).

Two leukemogenic viral populations were derived from a radiation leukemia virus of the C57BL mouse. One (FB), in which only B-tropic virus could be detected, was obtained in vivo by serial passage of cell-free extract in newborn rats. The second (3C), a complex containing at least B-tropic and xenotropic viruses, was produced in vitro by a permanent cell line (13-3C) established from the spleen of a virus-infected C57BL mouse. In molecular hybridization experiments, the 70S RNA of Gross leukemia virus hybridized 96 and 78% of FB and 3C radioactive complementary DNA's, respectively, with a relatively high thermal stability of the duplexes formed. In contrast, the 70S RNA of Rauscher leukemia virus hybridized 23 and 20% of the FB and 3C DNA probes, respectively, with a low thermal stability. The rat-grown FB virions exhibited 50% genome homology with the viruses produced in vitro on the 13-3C cells. Finally, hybridizing the FB and 3C probes with normal or leukemic mouse spleen DNA's resulted in 89 to 100% homology. The rat-grown virions did not appear to contain detectable rat cellular DNA sequences, while about 20 complete copies of their nucleotide sequences were detected in covalent linkage with FB-infected rat spleen DNA. These findings strongly support the endogenous murine origin of the investigated virions.

After X-irradiation at pronuclear stage, mice eggs from certain strains are reversibly blocked in G2 phase of the first cell cycle. However, evolution of polypeptide synthesis takes place in a normal way, except for three polypeptides sets of 30, 35 and 45 kd molecular weight that appear in dividing controls and not in blocked, irradiated eggs. It is shown that those first mitosis-specific polypeptides result from post-translational modifications, involving phosphorylations.

The development of a fast-growing hepatoma (HW-165) in normal euthyroid Wistar rats, was shown to be stimulated by daily injection of a dose of triiodo-L-thyronine (T3) as low as 1.5 microgram/100 g body weight. Administered to thyroidectomized rats, T3 completely restored the frequency of tumor initiation and accelerated the growth of the hepatoma, which had been considerably slowed down in hypothyroid rats. Contrary to other investigators, working on fast-growing Morris hepatomas, we did not observe any significant increase in the T3 level in the serum of hepatoma HW-165-bearing rats. Similarly, the tetra-iodo-L-thyronine (T4) levels were of the same order of magnitude in the blood of both normal and tumor host animals. The mitotic activity was reduced in hepatomas transplanted in hypothyroid rats and increased in tumors of T3-treated animals. These results support the assertion of Short (20) suggesting a relationship between the mitogenic effects of iodothyronines on the normal hepatocyte and on transplanted tumors of hepatic origin.

In some strains of mice, eggs when X irradiated during the pronuclear stage, undergo a mitotic block in the G 2 phase of the first cell cycle and cleave when the second division takes place in controls. The importance of this effect varies considerably with the strain and depends exclusively on the maternal genotype. In previous work, two-dimensional electrophoresis showed that eggs blocked at the one-cell stage after irradiation, undergo the same modifications in polypeptide synthesis as two-cell controls of the same age, except at the time of normal first mitosis, where three polypeptide sets of 30, 35 and 45 kDa appear only in cleaving controls. In the present study, we have found phosphorylations in dividing controls, on polypeptides of 30, 35 and 45 kDa. These phosphorylations are not seen in blocked irradiated eggs.