Fatty acid content in the muscles and liver of mice developing sarcomas induced by 3-methylcholanthrene and Moloney murine sarcoma virus

A comparative analysis was made for the fatty acid composition of lipids in the malignant muscular tissue, muscle and liver under blastomogenesis induced in mice by the Moloney sarcoma virus and 3-methylcholanthrene. The relation of the found changes in the fatty acid composition to the blastomogenesis stages is shown. The development of the tumour node is accompanied by a decrease of the fatty acid amount in the animal tissues and by its increase in the tumour. A spontaneous regression of the Moloney sarcoma results in increased level of the fatty acid content in the animal tissues followed by its normalization.     

DNA-bound lipids of the cells of Zajdela ascites hepatoma and of Ehrlich ascites cancer

DNA-bound neutral lipids (NL) and phospholipids (PL) were isolated and characterized from the Zajdel ascites hepatoma (ZAH) and Ehrlich ascites carcinoma (EAC) cells. The lipids are represented by light- and tightly bound components. It was shown, that the tumour DNA contained minor amount of NL (25, 17 micrograms and 16.87 micrograms per mg DNA, respectively) and of PL (4.54 micrograms and 5.36 micrograms per mg DNA, respectively, for ZAH and EAC). The composition of the tumour DNA-bound lipids was shown to differ from that of DNA-bound lipids of liver and thymus of intact rats by the next parameters: NL/PL ratio is much more than one; increased content of FC; equal values of the three basic ratios--CE/FC, NL/PL, cholesterol/PL, presence of mono- and triglycerides.     

Effectiveness of cycloplatam in the free form and included in liposomes during metastasis of GA-1 tumors in A/He mice

The 6-10-fold freezing and thawing of routine multilamellar phospholipid vesicles in cycloplatam solution give rise to liposomes which entrap in their aqueous phase up to 10 mg of the drug per 100 mg of lipids. When injected intravenously to mice with HA-1 tumour metastases in the liver, liposome-encapsulated cycloplatam increased their survival rate by 112-123%, whereas free cycloplatam--only by 39-61% as compared to the control. The intramuscular transplants of the tumour were affected similarly by both liposome-encapsulated and free cycloplatam (the tumour growth was inhibited by 67.1 and 75.6%, respectively).     

Relation between disorders of glucose metabolism, secretion of somatotropic hormone, thyroxine, thyrotropin and hematocrit indices in rats with transplanted hepatomas

The levels of growth hormone (GH) in the blood of rats with ascite Zajdela hepatoma and hepatoma 27 (H-27) are shown to increase during the tumour growth. Stimulation of the GH secretion is a result of the hypoglycaemic stress. An increase in the blood GH secretion is also observed in the fasting rats. To reveal the predominance of catabolic GH effects over the anabolic ones in the tumour host determination of the molar insulin/GH ratio in the blood is suggested. A direct correlation is found between reduction of this index, glycaemia and the content of liver glycogen. A short-term induced hyperglycaemia evokes a paradoxical reaction in terms of GH secretion. In contrast to control fasting rats, in tumour-bearing animals no correlation between thyrotropin and thyroxine blood concentration could be observed. Anaemia increasing progressively in the course of the tumour growth may be the cause of the above phenomenon.     

Decrease in the antimetastatic effect of vinblastine administered in liposomes

The model of experimental metastases in the HA-1 tumour in the liver of A/He mice was used to show that the anti-tumoural effect of cis-dichlorodiamminoplatinum being used in the liposomes increases, while that of vinblastine (VB) decreases. It is suggested that the low activity of liposome-encapsulated VB as to its influence on the tumour growth in the liver is a result of preferable uptake of liposomes by Kupffer cells and hepatocytes from where VB cannot diffuse into tumour cells since it binds to intracellular tubulin.     

Selective inhibition by chloramphenicol of protein biosynthesis in ascites tumor cells

Chloramphenicol in a dose of 50-200 micrograms/ml sharply inhibits the incorporation of 14C-labelled amino acids into proteins of ascites Zajdela hepatoma cells while it has no effect on protein biosynthesis in rat liver cells. In vivo chloramphenicol selectively inhibits this process in ascites tumour cells of rat Zajdela hepatoma and mouse Ehrlich carcinoma and hepatoma 22a, without inhibiting the process in various organs of tumour-bearing animals. The inhibition of labelled amino acid incorporation into nuclear and especially nuclear matrix proteins is more pronounced than into the whole tissue. A certain degree of inhibition was revealed in liver cells as well.     

Detection of chalones produced by a primary tumor in the blood of mice with Lewis carcinoma

The substance fraction precipitated in 81% ethanol from blood or tumour tissue of mice with Lewis (3LL) carcinoma on the 13th, 20th and 32nd day after the tumour transplantation is established to inhibit the processes of proliferation in the cell culture of the same tumour. The fraction isolated on the 7th day after transplantation stimulated the proliferation. No inhibition of proliferation was observed when studying the effect of the same fraction isolated on the 13th and 20th day from blood of mice with B-16 melanoma on the 3LL carcinoma. This fact suggests a tissue-specific action of proliferation inhibitors isolated from blood of mice with Lewis 3LL carcinoma and permits considering them as chalones. An assumption is advanced that the primary tumour synthesizing chalones and secreting them into blood can regulate not only its own growth but also the growth of remoted metastases.     

The content of tumor angiogenesis factor in the blood serum of C57Bl/6 mice during the growth and metastasis of transplanted tumors

The tumour growth and metastasis development after the primary tumour removal is accompanied by the appearance of the tumour angiogenesis factor (TAF) in blood. The TAF level directly correlates with the volume of tumour cell masses. These results confirm the present notions about the close correlation of the tumour growth and neovascularization and may be used to control the activity of neovascularization and malignant growth.     

Appearance of new transplantation antigens in tumor cells treated with RNA

Immunization of mice with the Wistar rat liver tissue increased their resistance to the subsequent intramuscular transplantation of Krebs-2 tumour cells preincubated with the rat liver RNA and did not affect the transplantability and growth of the same untreated tumour cells. The growth of the tumour cells pretreated with allogenic RNA did not differ from the growth of the untreated tumour cells when the mice were immunized with material genotypically different from the RNA tissue-source. When the immunizing tissue and RNA source were genotypically identical, the mass of the tumours growing in three tested mice strains (A/He, CC57BR, BALB/c) was 40-50% less than that of untreated tumours and the enhancement effect was observed in C3Hf mice. It is suggested that RNA preparations induce the appearance of the transplant antigens in tumour cells similar to those of RNA donors tissues. The effect of RNA preparations was abolished by RNAse incubation.     

Changes in the RNA content of the blood plasma in rats with Ehrlich ascitic cancer

The RNA content in the blood plasma of tumour-bearing animals correlates with the tumour growth stage. The development of Ehrlich carcinoma in rats is followed by the RNA increase in the blood plasma, while spontaneous regression of the tumour is accompanied by a decrease of the RNA content in the blood plasma of rats with Ehrlich carcinoma almost to the normal level. The fractional spectrum of the blood plasma RNA in the tumour bearing rats is similar to that of the cell-free ascitic fluid of rats.     

Phospholipid composition of tumors and homologous tissues of rats exposed to dimethylnitrosamine

Quantitative changes in phospholipid spectra of blood serum, liver, kidneys and tumour tissues were determined at different stages of carcinogenesis induced by nitrosodimethylamine in rats. It was established that tissue of kidney tumours differs from homologous tissue only in the total amount of phospholipids as well as of cardiolipin phosphatidylethanolamine, phosphatidylserine and sphingomyelin. Essential changes were revealed in the phospholipid spectrum of blood serum and liver of tumour-bearing rats. The inverse correlation was found in phosphatidylethanolamine and phosphatidylserine amount in these tissues.     

Proliferation and differentiation of hematopoietic stem cells during tumor growth

The influence of transplantable tumour on migration, proliferation and differentiation of haemopoietic stem cells was studied. It is shown that in the initial period of tumour development the migration and proliferation of stem cells intensify. In the final stage of the tumour growth the quantity of haemopoietic stem cells decreases considerably in the bone marrow, spleen, and peripheral blood. It is established that during the tumour growth the differentiation of stem cells from the spleen changed towards erythropoiesis.     

Hemolytic resistance of erythrocytes in the development of experimental tumors

Peculiarities of variations in the mechanical resistance of erythrocytes from mice with tumours were studied depending on the growth stage of tumours (lymphoma NK/Ly and sarcoma S-37). The accumulation of erythrocytes with the increased mechanical resistance at the stage of rapid tumour development (on the 4 to 6th days) was revealed by the kinetic method of ultrasonic haemolysis. Quantitative parameters of ultrasonic haemolytic resistance of erythrocytes from normal and tumour-bearing mice were used as criteria for the red blood cell changes depending on the cell age in blood. The increase of haemolytic resistance at the rapid stage of tumour growth may be caused by a higher number of "young" erythrocytes in blood. Ultrasonic haemolytic resistance increases when there is no changes in the erythrocyte quantity and hemoglobin concentration. The kinetic study of ultrasonic haemolysis of the erythrocytes isolated from peripheric blood permits estimating the reaction of the blood forming organs to the origin and development of tumours.     

Antitumor effectiveness of chalone-like proteoglycans isolated from normal and tumor tissues

Chalone-like proteoglycans (PG) have been isolated from 22a hepatoma, spontaneous adenocarcinoma of the mammary gland of C3H/He mice and from transplanted X-ray-induced lymphoma in C57Bl mice. It has been found that the biological activity of these PG was considerably weaker than that of PG taken from the liver, mammary gland and spleen of cattle. PG from 22a hepatoma produced a weaker tissue-specific antimitotic effect as against PG from the liver when acting on the liver cells of 6-day C57Bl mice, while the lymphoma PG under these conditions was ineffective. PG from the liver and mammary gland inhibited the growth of certain transplanted tumours in vitro. The lymphoma PG has stimulated the tumour growth.     

Experimental study of the need for the dearterialization of tumors

The influence of local ischaemia on the tumor growth rate and the character of metastases of Walker's carcinosarcoma-256 (WCS-256) and carcinoma RS-1 was studied in 168 male rats of Wistar line. The authors observed the dependence between the quantity of tumour cells in peripheral blood both under normal conditions and under local ischaemia in the tumour area. The efficiency of the produced ischaemia was controlled by the polarographic methods. The local ischaemia decreases grafting of tumours, reduces the growth rate and formation of the regional and distant metastases and decreases the quantity of the tumour cells in the peripheral blood.     

The components of the blood plasma fibrinolytic system in mice with Lewis lung carcinoma

The fibrinolysis system components of the circulating blood plasma have been studied in experiments on C57Bl/6 mice in the dynamics of growth and metastasis of the Lewis lung carcinoma. It has been shown that a growth and metastasis of malignant tumours are accompanied by the fibrinolysis activity inhibition. Changes in the fibrinolysis processes are observed already on the 3rd day after tumour inoculation. These changes increased in the course of the tumour growth progress.     

Capacity of rhabdomyosarcoma cells to produce substances with somatomedin and mitogenic activity

The rats aged 1, 3, 12 and 15 months were intravenously injected with 10,000 of the rhabdomyosarcoma cells. 3 weeks following the injection multiple tumour clones were observed in the lungs of experimental animals, the rats aged 1 and 15 months showing a significantly greater tumour yield than those aged 3 and 12 months. The level of the mitogenic and somatomedin activity increased both in the blood serum and in the lung tissue, the activity varying with the number of tumour clones. Rhabdomyosarcoma cells, probably, synthesize and release growth factors into the blood.     

The effect of lymphocytes on the growth of transplanted adenocarcinoma of the colon in mice

The activation of spleen lymphocytes during tumour growth on the syngeneic mice has been shown. The activated lymphocytes were able to restore the tumour growth after cyclophosphane induction of immunodeficiency. Activated lymphocytes of mice acted the same way with liver regeneration and isoproterenol induction of salivary gland hyperplasia. The inhibitory effect of lymphocytes has been also shown during this process. Both stimulation and inhibition were the function of the ThyI lymphocytes. The regularities shown may reflect important processes of cell proliferation regulation in multicellular organisms.     

Local immunoregulatory action of malignant tumors

It is suggested that the products of tumour metabolism are able of changing the electrokinetic parameters of lymphoid cells, thus providing the favourable growth conditions for the tumour. The studies have been carried out with ascites strain of the ovary tumour. It is shown that ascite liquid increases the electrophoretic mobility of the lymphoid cells in vivo and of blood lymphocytes of control rats (especially of old animals) in vitro. The changes in electrokinetic parameters of the lymphoid cells may be a cause of insufficient response of the local immune reactions.     

Characteristics of disorders of water-electrolyte homeostasis in rats with transplantable hepatomas

The growth of ascitic Zajdela and solid 27 hepatomas in vivo is accompanied by significant changes in parathyroid hormones, calcitonin and aldosterone blood levels. In periods close to terminal ones, their level decreases presumably as a result of energy deficiency in the endocrine glands. The arising hormonal shifts are a result of a "metabolic stress" caused by the growing tumour.