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Query: UMLS:C0598934 (tumor growth)
 58,965 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A significant tumor damaging effect (growth inhibition) on transplanted syngeneic sarcoma in mouse was obtained by means of pH-dependent activation of a transport form of a cancerostatic drug by an enzyme foreign to the organism. This effect was achieved by combined administration of 8-0-(alpha-L-arabinofuranosyl)beta-peltatin-A as a transport form of beta-peltatin-A and the exogenous enzyme alpha-L-arabinofuranosidase from Aspergillus niger and additional increase of the acidity of the tumor by injection of glucose. The combined application of the transport form plus enzyme showed a more favorable effect on selectivity than free peltatin when a quantitative comparison was made between the tumor growth inhibition and the damage to the blood picture.
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PMID:Experiments to increase the selectivity of tumor chemotherapy by means of in vivo activation of transport forms of cancerostatics by exogenous enzymes. 2 45

A 53 year old woman presented with diabetes mellitus, hyperglucagonemia (600 to 1,500 pg/ml), clinical hyperparathyroidism and an abdominal mass diagnosed on biopsy as an islet cell carcinoma. Glucagon content of the tumor was 0.78 mug/g wet weight. Hourly blood samples during a 24 hour period revealed a direct correlation between plasma glucose and glucagon. The oral administration of glucose paradoxically increased whereas the intravenous administration decreased plasma glucagon. Circulating glucagon levels were markedly increased with arginine and epinephrine infusion. Both short- and long-term administration of alpha adrenergic blockade depressed the glucagon response to epinephrine infusion. In contrast, long-term alpha adrenergic blockade increased glucagon secretion despite improved glucose tolerance during a second 24 hour study. Although the patient demonstrated overt clinical and chemical findings of hyperparathyroidism, parathyroid hormone (PTH) was not detected in her plasma. The pattern of tumor growth was consistent with an origin from pancreatic islets. We conclude that (1) the tumor was responsive to physiologic stimuli known to affect glucagon secretion; (2) elevations of plasma glucagon levels with oral and dietary glucose suggest regulation of secretion by intestinal factors; and (3) improvement of glucose tolerance with alpha adrenergic blockade may be related to increased insulin secretion.
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PMID:Uncontrolled diabetes mellitus and hyperglucagonemia associated with an islet cell carcinoma. 4 4

Parenteral and enteral nutrition are being used as adjuncts to cancer therapy. A liquid diet formulation containing a 27% solution of glucose and 3.9% crystalline amino acids with electrolytes and vitamins was given continuously for a week via parenteral (iv), and via intragastric (ig) routes and also was given ad libitum via the oral or per os (po) route to groups of Buffalo rats with and without a Morris No. 7777 transplantable hepatoma to find out how these feeding procedures affect tumor-host interactions. Other groups of rats with and without the hepatoma were given solid food ad libitum. The following parameters were examined: mortality, carcass and organ weights, body and tumor growth, nitrogen balance, energy intake, fluid balance, urinalysis, hematology values, and serum protein levels. The results are considered with respect to the influence of the tumor on the host and the influence of the feeding procedure on the animal with and without a tumor. The presence of the hepatoma was associated with: higher mortality, a decrease in carcass mass, leucocytosis, anemia, a decrease in serum IgG, transferrin and albumin, and an increase in serum alpha fetoprotein. The iv and ig feeding procedures alone resulted in some mortality which was exacerbated by the presence of the tumor. Mortality was especially high in the tumorous rats on the ig feeding procedure. The degree of positive nitrogen balance and carcass mass was similar in non-tumorous rats fed the same liquid diet formula when given iv, ig, or po. Tumorous rats fed the liquid diet ad libitum showed anorexia and a significantly lower nitrogen balance. The iv and ig feeding of tumorous rats at a level which was well above those of the tumorous rats given solid or liquid diet ad libitum maintained the same degree of positive nitrogen balance as non-tumorous rats. Even though the iv feeding of tumorous rats maintained about the same degree of positive nitrogen balance as non-tumorous rats, these tumorous rats still suffered loss of carcass mass. It appears that the large rapidly growing hepatoma has priority for available nutrition over the host. It is further suggested that the rapidly growing hepatoma places an ever increasing demand on the available nutrients. Thus, a point is eventually reached where even supplemental nutritional support can no longer meet the needs of the growing hepatoma and the host.
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PMID:Tumor-host responses to various nutritional feeding procedures in rats. 10 99

The R3230AC mammary adenocarcinoma was not dependent on insulin; tumor growth was equal to or greater in diabetic rats than in intact animals. However, tumor growth was reduced when daily doses of insulin were administered. Treatment with estrogen inhibited growth of the R3230AC carcinoma, either in diabetic rats or in intact animals simultaneously treated with insulin. The effects of insulin plus estrogen treatment appeared to be additive in causing inhibition of tumor growth. Tumors from diabetic rats showed few metabolic alterations as reflected by little or no changes in the activities of selected glycolytic enzymes, pyruvate kinase, phosphofructokinase, and hexokinase, nor any striking changes in the activities of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase, representing the pentose phosphate pathway. A modest reduction in the ratio of utilization of (1-14C)glucose: (6-14C)glucose was seen in vitro by tumors from diabetic rats. It was concluded that insulin, along with estrogen and prolactin, should be considered as a hormonal factor that influences growth of this automonous, hormone-responsive adenocarcinoma.
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PMID:Influence of insulin on estrogen-induced responses in the r3230ac mammary carcinoma. 12 68

1-(2-Chloroethyl)-3-(beta-D-glucopyranosyl)-1-nitrosourea (GANU), a water-soluble nitrosourea, differs from 2-[3-(2-chloroethyl)-3-nitrosoureido]-D-glucopyranose (chlorozotocin) by the placement of the cytotoxic group on C-1 of glucose. Its biological and biochemical properties are compared with those of chlorozotocin. At a 10% lethal dose (10 mg/kg i.p.), GANU demonstrates minimal myelosuppression. This dose failed to depress normal bone marrow DNA synthesis, in contrast to a 96% inhibition in L1210 DNA synthesis. In L1210 cell suspension, equimolar doses of GANU and chlorozotocin produced equivalent degrees of inhibition in DNA synthesis. GANU has significant L1210 activity in BALB/c X DBA/2 F1 mice treated on Day 2 of tumor growth. A 117% increased life-span and 15% 45-day survivors are atained with 15 mg/kg i.p., a 50% lethal dose. However, in concurrent studies using randomly selected littermate groups of mice, GANU proved less active than chlorozotocin which produced a 306% increased life-span (15 mg/kg i.p.). GANU and chlorozotocin have similar in vitro alkylating activity but the in vitro carbamoylating activity of GANU is sevenfold that of chlorozotocin. On a molar basis, the lethal toxicity of GANU is twice that of chlorozotocin. The significant carbamoylating activity of GANU may contribute to its greater toxicity and therefore limit the mumoles of alkylating agent that can be administered to the tumor. These structure-activity studies further confirm that the addition of a glucose carrier to a cytotoxic nitrosourea moiety can selectively reduce bone marrow toxicity while retaining antitumor activity.
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PMID:Biological and biochemical properties of 1-(2-chloroethyl)-3-(beta-D-glucopyranosyl)-1-nitrosourea (NSC D 254157), a nitrosourea with reduced bone marrow toxicity. 13 78

The effects of estrogens on transport and incorporation of amino acids into the R3230AC mammary adenocarcinoma were studied in vivo and in vitro. Dissociated tumor cells from ovariectomized rats, like those from diabetic rats, displayed elevated transport of proline, representing entry by the A system; transport of phenylalanine (L system) was unaltered, as was glucose transport and its utilization. Administration of estradiol valerate decreased the entry of proline into tumor cells from intact, diabetic, or ovariectomized animals; the response to the steroid hormone was greater in ovariectomized or diabetic rats compared to intact animals. The time course of the effects of estrogen treatment was examined in diabetic rats. By 72 hr, transport of both proline and leucine was significantly decreased; incorporation of leucine into proteins and uridine into RNA was significantly reduced by 24 hr after injection of estradiol valerate. The effects of estrogen in vivo to reduce transport of amino acids and their incorporation into proteins appeared to correlate with the reduced tumor growth observed. Experiments were performed to examine the effects of 17 beta-estradiol in vitro on amino acid transport into dissociated cells from ovariectomized or diabetic rats. Under these experimental conditions, 17 beta-estradiol (10(-6)M) inhibited proline transport with little or no effect on leucine transport in cells from ovariectomized rats; in cells from diabetic rats, proline transport and leucine incorporation were significantly reduced by estradiol, whereas phenylalanine transport was slightly inhibited (approximately 20%). The effect of estradiol in vitro was also manifest in tumor cells obtained from diabetic rats treated in vivo with estradiol valerate; estradiol in vitro caused a further reduction in proline transport but not in leucine transport, results that imply some specificity to the action of estrogen on the A system. Since we had earlier shown that insulin action on transport in these tumor cells were directed towards the A system, we examined the effects of insulin, estradiol, and their combination in vitro on proline and leucine transport. Insulin (10(-8) M) stimulated proline transport; 17 beta-estradiol, at a selected lower level of 10(-8) M, inhibited proline transport. When both were added in vitro, estradiol (10(-8 M) was capable of significantly reducing the insulin (10(-8) M)-induced increase in proline transport. Leucine transport was not altered in any of these experiments. Together, these data suggest that estrogens are capable of inhibiting amino acid transport into the R3230AC mammary carcinoma, an effect that is compatible with reduced tumor growth. The possible relationship of estrogen and insulin at the level of amino acid transport remains to be elucidated.
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PMID:Effects of estrogen to alter amino acid transport in R3230AC mammary carcinomas and its relationship to insulin action. 15 4

Cells dissociated from the R3230AC mammary adenocarcinoma from intact and diabetic rats were examined for insulin binding and glucose transport. The Kd for insulin binding, approximately 10(--10) M, was similar in all tumors studied. However, the apparent number of receptor sites per cell increased in cells from diabetic rats. Kinetic analysis of 3-0-methyl glucose (3-OMG) entry showed both diffusional and passive carrier characteristics. Insulin (4 X 10(--9) M) in vitro did not affect diffusional entry, whereas the hormone altered the passive carrier system, as reflected by an increase in Km and Vmax. Insulin decreased initial velocity of glucose transport at 4--6 mM glucose levels but increased initial velocity of glucose transport at 20 mM glucose. An explanation of the role of insulin on tumor growth in vivo from effects on glucose transport in vitro is proposed.
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PMID:Insulin binding and glucose transport in the R3230AC mammary adenocarcinoma. 17 15

Chick embryo (CE) fibroblasts and normal rat kidney (NRK) cells transformed by temperature-sensitive (ts) mutants of avian sarcoma virus (NY68, LA23, LA24, LA25, LA29, LA31, GI201, GI202, GI251, GI253 induce tumors on the chorioallantoic membrane (CAM) of chick eggs at temperatures that correspond to the permissive and nonpermissive temperatures used to induce conditional expression of the "transformed" phenotype in these cells when cultured in vitro. Chick embryo cells infected with transformation-defective mutants of ASV (td101, td108) or RAV-50 were nontumorigenic under the same conditions, as were nontransformed CE and NRK cells. This indicates that the CAM is not an unusually susceptible substrate for cell growth and that the ability of tsASV-transformed cells to form tumors at nonpermissive temperatures reflects their true tumorigenicity. In contrast, a ts mutant chemically transformed rat liver cell line, ts-223, only formed tumors on the CAM under permissive conditions. The wild-type parent cells (W-8) of this mutant produced tumors at both permissive and nonpermissive temperatures. Direct implantation of microprobe thermometers into tumors caused by ts-ASV-transformed cells at nonpermissive temperatures confirmed that tumor formation occurred in a stable temperature environment and was not due to temperature fluctuations which might have created semi-permissive conditions for tumor growth. Cells isolated from tumors formed at nonpermissive temperatures and recultured in vitro displayed temperature-dependent hexose transport and colony formation in agar similar to the orginal parent cell inoculum. Similarly, virus recovered from tumors at nonpermissive temperatures retained the ts mutation.
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PMID:Cells transformed by temperature-sensitive mutants of avian sarcoma virus cause tumors in vivo at permissive and nonpermissive temperatures. 22 65

Increased glucose levels in blood of diabetic and of normoinsulinemic hyperglycemic CBA/H mice were accompanied by suppressed growth of aplastic carcinoma. Tumors maintained in diabetic mice grew faster after each subsequent transplantation into diabetic mice, but those maintained in hyperglycemic normoinsulinemic mice grew at a constant rate. Evidence revealed that tumor growth was suppressed by hyperglycemia. The observed proliferation enhancement of aplastic carcinoma maintained in diabetic mice was caused by de novo insulin synthesis, probably by the tumor cells themselves.
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PMID:Aplastic carcinoma in diabetic mice: hyperglycemia-suppressed proliferation rate and insulin synthesis by tumor cells. 28 69

A study was made of the action of glucose or sodium succinate on subpopulations of the Ehrlich-I.Ch.Ph. ascite strain characterised by markers "A1" and "A", resp. After i.p. injection of glucose the amount of "A1"-cell reached 50 and almost 100% on the 5th and 7th day of tumor growth. After the transplantation of "A1"-cells into intact animals, a homogenous cytogenetic feature of subpopulation persisted during 2 passages only. Kinetics studies of a subvariance of the Ehrlich-I.Ch.Ph. tumor containing "A1"-cells show that the tumor growth rate and grade of malignancy slightly differ from those seen in the controls.
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PMID:[Polymorphism of a tumor cell population and selective processes. III. A change in the correlation of tumor cell subpopulations of the ascitic strain of Ehrlich-I.Ch.Ph. under the influence of glucose and sodium succinate]. 29 Dec 23


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