Lewis Lung Tumor Research Articles

Lewis lung tumor system as a model for studying the immune function in syngeneic in equillibrium allogeneic chimeras.

Lewis lung tumor (LLT) passaged in F1 hybrids of the original C57B1/6 strain, where it arose spontaneously, is rejected by allogeneic SWA (Swiss albino) mice. However, aggregation chimeras derived from these SWA mice and the F1 hybrids of C57B1/6 developed an increased growth of primary tumor and reduced number of metastases when compared with the F1 hybrids. In the present study LLT passaged in C57B1/6 mice is not rejected by SWA mice. It is demonstrated that in aggregation chimeras now derived from two strains both taking the tumor, primary tumor growth was enhanced and the number of metastases reduced as in the former experiment. The tendency of reactions of lymphatic orgains in chimeras to tumor burden was comparable with the SWA and F1 hybrid (C57B1/6 multiplied by SWA and SWA multiplied by C57B1/6) recipients' response. Furthermore, chimeras had the highest spleen enlargement. Possible alternations in immune functions of chimeras due to their differing genotype combination are discussed in the LLT model.

Fractional incorporation of [3H]thymidine and DNA specific activity as assays of inhibition of tumour growth.

The Fractional Incorporation (FI) of [3H] thymidine ([3H]TdR) has been examined in small lung tumours after cyclophosphamide (CY) treatment in vivo and compared to the DNA specific activity (SA) at different times after treatment. FI was found to correlate with the incidence of labelled cells after treatment, whereas SA did not, due to the loss of DNA from drug-killed cells 72 h after treatment. The FI is independent of the precursor concentration in the tissue, and therefore may give a better index of DNA synthesis in irregularly perfused tissues than SA. Following either CY or 60Co radiation treatment, the time necessary for FI to reach the pretreatment level is quite similar to the growth delay measured for the FI depression 45 h after treatment and growth delay has been established in the Lewis lung tumour, which would allow the prediction of growth delay induced by another agent to be made within 2 days of treatment.

Suppressed Tumor Growth and Metastasis by Vitamin A + BCG in Lewis Lung Tumor Bearing Mice

The anti-tumor effect of vitamin A and/or BCG was investigated in Lewis lung tumor system. Tumor growth and lung metastases were significantly suppressed, when tumor cells were mixed with BCG and inoculated subcutaneously into vitamin A-treated animals. Survival time was also prolonged by the same treatment. Vitamin A alone, without BCG, showed no effect on tumour growth, lung metastases or survival time.

ChemInform Abstract: SYNTHESES OF HETEROCYCLIC FUSED THIAZOLE ACETIC ACIDS. 2

Abstract3‐Brom‐3‐p‐chlorbenzoyl‐propionsäure (Ia) bzw. ihr Ester (Ib) werden mit 2‐Mercaptobenzimidazol (II) umgesetzt.

A soft agar colony assay for Lewis lung tumour and B16 melanoma taken directly from the mouse

A soft agar colony assay has been developed for the B16 mouse melanoma and the Lewis lung tumour. The special features of the technique are the use of a gas phase with 5% O2 instead of air and the addition of rat red blood cells. Single cell suspensions are prepared by trypsinization from the solid tumour and the cells are plated out in 0-3% agar over a layer of 0-5% agar in 30-mm Petri dishes. After 8 to 15 days' incubation in 5% O2, colonies of more than 50 cells are produced. Plating efficiencies of between 30 and 50% are usually obtained. The addition of up to 10(4) heavily irradiated tumour cells gives some further improvement in plating efficiency for the B16 melanoma but not for the Lewis lung tumour. Applications of the technique to measure cell survival in the two tumours after treatment with cytotoxic drugs and radiation are reported. The scatter of experimental points is relatively small, and in comparative experiments good agreement has been obtained with results using in vivo assay techniques.

Syntheses of heterocylic fused thiazole acetic acids. 2.

A number of tricyclic and bicyclic fused thiazole-2-acetic acid derivatives were prepared and the chemistry and biological properties of these compounds are discussed. Many of the esters exhibited antitubercular activity. The bicyclic thiazole-2-acetic acids had antidepressant activity. Interesting antimetastatic activity against Lewis lung tumor in mice was found with several compounds, in particular, the thiazolo[3,2-a]benzimidazole-2-acetic acid derivative XI.

Anti-tumour and anti-metastatic activity of 3-(P-Chlorophenyl)-2,3-Dihydro-3-Hydroxythiazolo (3,2-A)-Benzimidazole-2-acetic acid (WY-13,876).

Extensive investigation of 3-(p-chlorophenyl)-2,3-dihydro-3-hydroxythiazolo(3,2-alpha)-benzimidazole-2-acetic acid (Wy-13,876) in BDF1 mice implanted with Lewis lung tumour has shown that it is an effective anti-tumour and anti-metastatic agent. In vitro examination using HEp-2 human epidermal tumour cells has indicated that Wy-13,876 is not cytotoxic. When mice implanted with Lewis lung tumour and treated with Wy-13,876 are also injected with anti-thymocyte serum, an increase in lung metastases is observed suggesting that thymocyte activity is involved in the drug's mechanism of action. An increase in peripheral T lymphocytes observed in rats 18 h after a single oral dose of Wy-13,876 further supports this possibility. When Wy-13,876 is given to tumour -bearing mice in combination with low, ineffective doses of 5-fluorouracil or cyclophosphamide, further reduction of primary tumour growth is observed.

Enhanced tumor growth in chimeric mice.

Chimeras were produced by aggregation of B6D2F1 and SWA early embryos. Lewis lung tumor, syngeneic in B6D2F1, was used to study tumor growth and metastases in these chimeras. Enhanced tumor growth, low metastases rate and pronounced enlarged spleen could be observed in SWA equilibrium B6D2F1 chimeras 21 days after inoculation of tumor cells. Increased activity of suppressor T-cells which might be due to permanent allogeneic stimulation in chimeras is discussed as one of the possible mechanisms.

Inhibition of tumor growth in syngeneic chimeric mice mediated by a depletion of suppressor T cells.

Syngeneic chimeric (lethally irradiated and reconstituted with syngeneic bone marrow cells) mice manifested an increased resistance to the development of Lewis lung carcinoma. In addition, these mice had a higher response to polyvinylpyrrolidone and a reduced reactivity to T mitogens. The present findings suggest that syngeneic chimeric mice lack suppressor T cells shown to regulate the development of Lewis lung tumor and the response to polyvinylpyrrolidone. Other components of the T cell population, such as helper cells responding to sheep red blood cells or cells involved in allograft rejection, assayed in these syngeneic chimeras were found unaffected. The fact that chimeric mice are deficient in a certain suppressor T cell population whereas other T activities are normal suggests the existence of different cell lines within the T cell population.

The lung-colony assay: extension to the Lewis lung tumour and the B16 melanoma--radiosensitivity of B16 melanoma cells.

Experiments are described which demonstrate that a lung-colony assay can be used to study the viability of unknown cell populations from the B16 Melanoma or the Lewis Lung Tumour. It is shown that the number of lung colonies formed can be increased by the addition of plastic microspheres to the injected cell suspension or by pre-irradiating the lungs of the recipient mice. The colony technique has been used to isolate melanotic and amelanotic cell-lines from the B16 Melanoma which were found to have different growth-rates. In vitro radiation survival curves for B16 Melanoma cells have also been established, and these have parameters in the usual range for mammalian cells.

Tumor localization studies with radioactive lanthanide and actinide complexes

153Smcitrate solutions were prepared from enriched 152Sm2O3 which had been irradiated at 1012n cm−2 s−1 in the University of Alberta Slowpoke reactor. 153Sm was rapidly bound (93% in 2 h) by Melanoma 2AB cells in tissue culture upon incubation in the presence of 153Smcitrate (1.9 nmol 106 cells). In vitro ultracentrifugation studies of 153Smcitrate solutions showed that colloid formation under incubation conditions could have been responsible in part for the uptake by cultured cells. Low uptakes (<1% in 2h) of 67Gacitrate were seen under similar conditions.153Smcitrate injected into BDF1 mice (Lewis lung carcinoma) and Copenhagen × Fisher rats (Dunning R3327-H prostatic tumors) was concentrated mainly in the liver, with some tumor and bone uptake. The percent of injected dose per organ for 153Sm and 67Ga in the murine and rat models respectively, 24 h after i.v. dosing, was 17.2 ± 4.7 and 2.0 ± 0.6 (tumor), 63.9 ± 7.9 and 14.4 ± 1.4 (liver) and 0.6 ± 0.1 and 1.3 ± 0.1 (blood); % injected dose g−1 femur was 6.2 ± 2.7 and 12.9 ± 2.7, respectively. Scintigrams of rats showed qualitative biodistributions similar to the quantitative mouse data obtained by dissection studies. The high hepatic uptake detracted from the otherwise superior tumor localization of 153Sm citrate when compared to 67Gacitrate in these models. The murine Lewis lung tumor index (% injected dose g−1 tumor × tumor:blood) was 303.6 for 153Smcitrate and 48.9 for 67Gacitrate, 24 h after injection.

The growth of transplanted tumours in mice after chronic inhalation of fresh cigarette smoke.

The subcutaneous growth of the Lewis lung tumour in C57BL mice chronically exposed to fresh cigarette smoke was increased above that in age-matched control mice. When murine sarcoma virus (Harvey) induced tumour cells were introduced to the lungs of groups of BALB/c mice, only mice chronically exposed to fresh cigarette smoke died with tumour cells in the lungs. Tumour cell growth in mice during short term cigarette smoke exposure was indistinguishable from that in controls.

Immunological enhancement of tumor growth by syngeneic thymus-derived lymphocytes.

The role of lymphoid cells in the development of a transplanted syngeneic Lewis lung tumor (3LL) was investigated. It was found that thymocytes or thymus-derived lymphocytes could stimulate 3LL tumor growth in the recipients. This enhancing effect was manifested by a higher number of tumor takes, acceleration of tumor growth, and an increase in metastatic incidence. Lymphocytes from tumor-bearing mice were more effective than lymphocytes from nontumor-bearing controls in the manifestation of this phenomenon. Mice partially deprived of their T cell population by adult thymectomy manifested a striking reduction in tumor development.

Levamisole inactive in treatment of four animal tumours.

LEVAMISOLE (2,3,5,6-tetrahydro-6-phenylimidazo (2, 1-b) thiazole) a compound known to be active against a wide range of nematodes1,2, has been reported to enhance the humoral and cellular immune responses of animals and to reduce the incidence of both primary tumours and lung metastases in the Lewis lung (3a) tumour system in C57BL mice3. We report here studies on the effect of levamisole on the growth of four transplantable tumours, all known to be immunogenic. They were: a transplantable adenovirus 12-induced tumour of CBA mice4; a chick embryo lethal orphan (CELO) virus-induced tumour of hamsters5; a Moloney leukaemia virus-induced lymphoma of BALB/c mice6; and a chemically-induced metastasising anaplastic neoplasm of inbred rats7. We also studied the effect of levamisole on the humoral antibody response to influenza virus vaccine in hamsters.

Levamisole inhibits and cures a solid malignant tumour and its pulmonary metastases in mice.

WE have reported the stimulatory effects of racemic 2,3,5,6-tetrahydro-6-phenyl-imidazo (2,1,-b) thiazole, “tetramisole” and of its l-isomer, “levamisole”, on antibacterial immunization1 and on antibody-forming spleen cells in mice immunized with sheep red blood cells2. Tetramisole restored the impaired immunological system of aged mice3. The graft vs host reaction in F1 hybrid recipients was increased following inoculation of splenic cells from a parental donor previously stimulated by injection of these drugs4. These results and further studies in progress suggested that tetramisole and levamisole actively stimulated cell-mediated immunity and we wished to determine the effects of levamisole on the growth of a solid metastasizing tumour. Lewis lung (3 LL) tumour of C57B1 mice provides a good experimental model5–8; it has a rapid subcutaneous growth and the macroscopic pulmonary metastases can be easily counted 3 weeks after tumour inoculation8. We report the activity of levamisole against the growth of the primary subcutaneous 3 LL tumour and against the development of pulmonary metastases.

New drugs on the horizon in bronchogenic carcinoma.

The Chemotherapy Program of the National Cancer Institute in its drug development function sponsors for clinical trial a wide range of new antiplastic drugs. All of these drugs are tested in lung cancer which is considered one of the Program's “signal” tumor types. Among the new drugs sponsored for trial, which have shown evidence of activity against lung cancer, are the nitrosoureas of which three are in various stages of clinical evaluation. BCNU has shown activity in 9/83 (11%) while CCNU has shown activity in 11/52 (21%). The newest analogue, Methyl CCNU, is of great interest because of its superior activity against the advanced Lewis lung tumor. Other new agents which have shown some evidence of activity include adriamycin (30/147 = 20%), hexamethylmelamine (42/202 = 21%), and bleomycin (5/62 = 8%). Among the new drugs just completing Phase I evaluation and awaiting trial in lung cancer are: Iphosphamide (NSC 109724) an analogue of cyclophosphamide, ICRF-159 (NSC 129943), 5-azacytidine (NSC 102816), and Cis-platinum (II) Diamminodichloride (NSC 119875).

Formation, functions and regulatory importance of S-adenosyl- l-methionine

Summary The present status of knowledge of the synthesis and the metabolic and regulatory functions of S -adenosyl- l -methionine (AMe) is reviewed. The mechanism of the enzymatic synthesis of AMe from ATP from ATP and l -methionine by the ATP: l -methionine adenosyltransferase has been examined extensively and appears to be well characterized. However, recent kinetic investigations have uncovered complex deviations from classical Michaelis-Menten kinetics and suggest that the enzyme may be endowed with regulatory properties. The substrate specificity of ATP: l -methionine adenosyltransferase was found to be quite rigid. Only a few closely related analogues of methionine can be activated to their S -adenosylmethionine-derivatives by enzyme preparations obtained from yeast, E. coli and rat liver. A myriad of methionine analogues were also tested as inhibitors of the reaction in order to determine the conformation of l -methionine at the enzyme active site. In addition to dl -2-amino-4- trans -hexenoic acid, an acetylenic amino acid ( l -2-amino-4-hexynoic acid) and a cyclic amino acid (l-aminocyclopentanecarboxylic acid), all of which lack a sulfur atom, have been found to be the most potent inhibitors. The distribution of adenosyltransferase enzyme, in normal and malignant tissues, appears to be ubiquitous although the enzyme is most active in liver and moderately active in kidney and pancreas. The effects of steroid hormones, age and diet on the enzyme activities are reviewed. In addition to the widely recognized functions of AMe as a methyl group donor for transmethylations and as a propylamine donor for polyamine synthesis, a number of regulatory roles including feedback inhibitions and allosteric modifiers have been recently recognized. S -Adenosyl- l -methionine synthesis appears to be self-regulating in that AMe stimulates the hydrolysis of tripolyphosphate, an obligatory enzyme-bound intermediate. The complex B 12 -dependent methylation of l -homocysteine to l -methionine, utilizing N 5 -methyltetrahydrofolate, also requires AMe in what appears to be a priming methylation of the initial molecules of B 12 . Methionine biosynthesis in microbial systems is under feedback control. The enzymes involved in the formation of O -succinyl- l -homoserine and O -acetyl- l -homoserine (intermediates in the pathway of methionine bio-synthesis), in E. coli and yeast, respectively, are inhibited by S -adenosyl- l -methionine. However, in Neurospora the homoserine transacetylase reaction is unaffected by AMe but the following enzyme in the pathway, cystathionine synthetase, catalyzing the condensation of cysteine with O -acetyl- l -homoserine is powerfully inhibited. The allosteric effect of AMe in the lysine 2,3-aminomutase reaction and the requirement of AMe for bacteriophage restriction enzymes are described. The metabolism of S -adenosyl- l -methionine is examined and the implications of the major metabolic degradative pathways are discussed in detail both in mammalian and microbial systems. Data on S -adenosyl- l -methionine levels of normal mammalian tissues are presented together with information on the perturbation of these levels under various physiological and pharmacological conditions. Tissue levels of AMe are affected by administration of: (a) l -methionine, (b) drugs which are known methyl group acceptors, (c) monoamine oxidase inhibitors, and (d) analogues of methionine which are inhibitors of ATP: l -methionine adenosyltransferase reaction, specifically, l -2-amino-4-hexynoic and 1-aminocyclopentanecarboxylic acid. The latter two compounds when administered to male rats bearing the Walker-256 sarcoma and male mice bearing the Lewis lung tumor were found to increase the liver levels of AMe (50–100%) while decreasing these levels in the tumor (30–50%). A possible explanation for these opposing effects in the liver and tumors is obtained from in vitro data which show a stimulatory effect on the adenosyltransferases at low concentrations of these inhibitors. Data concerning the turnover rates of S -adenosyl- l -methionine in various mammalian tissues are also presented and discussed.

Control of malignant metastases by ICRF l59.

THE aim of cancer chemotherapy to destroy the last malignant cell may be unnecessarily ambitious if inhibition of metastases formation by chemotherapy could convert a malignant to a quasi-benign tumour. Systematic investigations into the experimental chemotherapy of spontaneous metastases have, however, been remarkably few1. This is perhaps not surprising in view of the technical difficulties experienced in the past in obtaining meaningful results. We have for some time attempted to study the effects of potential anticancer agents on the development of metastases by using the Lewis lung (3LL) tumour of mice, a tumour which produces metastases regularly, spontaneously and consistently to give multiple lung metastases2–4. We have attempted to do this not only because the ability to invade adjacent tissues is riot shared by most normal dividing tissues5, but also because it seems entirely possible that the basic processes of secondary tumour formation—invasion, dissemination and implantation—may have similar biochemical and biophysical characteristics in most malignant tumours.

An experimental model for studying factors which influence metastasis of malignant tumors.

AbstractImplantation of Lewis lung tumor into the leg muscle of BDF1 male mice resulted in tumor growth at the site of implantation. Metastasis to the lungs regularly occurred, early in the course of the disease, when the primary tumor was small and the mouse was capable of tolerating both surgery and chemotherapy.Treatment with cyclophosphamide alone was relatively ineffective in increasing the survival time of the animals and failed to increase the percentage of survivors.Radical surgery, performed early in the course of the disease, resulted in “cures” of almost 60% of the animals. Later, after definite metastasis had occurred, surgery alone was ineffective.Surgery plus adjuvant chemotherapy was in some instances more effective than surgery alone or chemotherapy alone in yielding “cures”. Also, in many instances, the combination constituted more effective treatment in increasing the survival time of the animals. However, cumulative drug toxicity appeared to interfere with the potential of the combination modality of therapy.