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Query: UMLS:C0001418 (adenocarcinoma)
 68,496 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. A non-pepsin proteinase, proteinase 2, was successfully isolated free from pepsinogen (by repetitive chromatography on DEAE- and CM-celluloses) from the gastric mucosa of a patient with a duodenal ulcer and the uninvaded mucosa of a patient with a gastric adenocarcinoma. 2. Proteinases 1a and 1b, found in gastric adenocarcinoma, were not found in the gastic mucosa of these patients. 3. Proteinase 2 was shown to have an asymmetrical broad pH-activity curve with a maximum over the pH range 3.0-3.7. 4. Proteolytic activity of proteinase 2 was inhibited by pepstatin; the concentration of pepstatin giving 50% inhibition is of the order of 3nm. 5. Inhibition of proteolytic activity by carbenoxolone and related triterpenoids indicated that at pH 4.0 proteinase 2 possesses structural characteristics relating it to the pepsins and at pH 7.4 to the pepsinogens. 6. The sites of cleavage of the B-chain of oxidized insulin for proteinase 2 at pH 1.7 and pH 3.5 were shown to be similar to those previously established for human pepsin 3 and for the cathepsin E of rabbit bone marrow. 7. The non-pepsin proteinase 2 (cathepsin) of human gastric mucosa has properties more similar to cathepsin E than to the cathepsins D.
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PMID:The isolation and properties of a non-pepsin proteinase from human gastric mucosa. 2 49

Several cell culture factors were found to influence in vitro expression of mouse mammary tumor virus (MMTV) in the mouse adenocarcinoma cell line Mm5mt/c1. Cells were propagated in a variety of commercially available cell culture media to which dexamethasone (DXM) was added as a stimulator of MMTV production. Culture seeding density, culture medium type, and glucose concentration each influenced MMTV production when expressed on a per cell basis. Maximum cell growth occurred in cultures grown in RPMI-1640 medium containing insulin. Those media which provided good cell growth were not necessarily optimal for virus expression. Addition of insulin did not stimulate MMTV synthesis although dexamethasone alone was stimulatory in all media used; however, maximum MMTV expression was obtained when dexamethasone and insulin were used in concert. Equivalent levels of MMTV-specific cell membrane antigen, MMTV-specific protein, and virus particles were produced at incubation temperatures of 32 degrees, 34 degrees or 37 degrees C; however, higher levels of virus-related RNA-dependent DNA polymerase (RDDP) activity were recovered from cultures incubated at 32 degrees and 34 degrees C than at 37 degrees C. Decreased levels of RDDP were attributed to enzyme thermolability at 37 degrees C incubation.
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PMID:Cell culture factors influencing in vitro expression of mouse mammary tumor virus. 6 18

By using a chemically defined serum-free (SF) medium for propagation of Mm5mtc1 mouse adenocarcinoma cell cultures and clonal derivatives, medium components including hormones, glucose and individual amino acids were evaluated as to modulation of mouse mammary tumor virus (MMTV) porduction. Insulin, hydrocortisone and dexamethasone each increased MMTV production on a per cell basis over constitutive expression that occurs in SF medium devoid of hormones. Maximum production occurred when all three hormones were present. Hormone-stimulated virus expression also was influenced by glucose concentration. Cell growth and maximum MMTV expression increased when thyroxine, asparagine, proline and serine were omitted from the medium formulation. The resulting modified SF medium provides and ideal system for the propagation of high MMTV-producer clones and for the study of the biochemical regulation of MMTV expression.
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PMID:Demonstration of components of serum-free culture medium effecting maximum in vitro expression of mouse mammary tumor virus. 7 89

Primary cultures of mammary cells from virgin Lewis rats were seeded at 5 X 10(5) cells per cm2 in medium 199 supplemented with 10% fetal calf serum, insulin (5 microgram/ml), prolactin (5 microgram/ml), estradiol (5 ng/ml), progesterone (0.5 microgram/ml), and hydrocortisone (0.5 microgram/ml). On the second or third day of culture, cells were exposed to either 7,12-dimethylbenz[alpha]anthracene (0.1 microgram/ml for 24 hr) or N-nitrosomethylurea (80 microgram/ml for 2 hr). The cells were later assayed for transformation by transplanting 10(6) or 10(5) cells into gland-free mammary fat pads of 3-week-old female hosts. Untreated cells produced only normal mammary outgrowths when transplanted. Cells treated with 7,12-dimethylbenz[alpha]anthracene or N-nitrosomethylurea produced abnormal outgrowths in 11% of the transplants. These abnormal outgrowths ranged from rapidly growing adenocarcinoma to alveolar and ductal hyperplastic lesions. The results indicate that rat mammary epithelial cells can be transformed by exposure to chemical carcinogens in culture and thus represent a potential in vitro model for epithelial cell transformation.
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PMID:Neoplastic transformation of rat mammary cells exposed to 7,12-dimethylbenz[alpha]anthracene or N-nitrosomethylurea in cell culture. 9 42

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

The binding of labeled insulin to dissociated R3230AC mammary adenocarcinoma cells from diabetic and intact rats was investigated in vitro. At 20 degrees, specific binding (total binding minus binding in the presence of 1000-fold excess or 10(-6) M unlabeled insulin) reached a plateau at 45 to 60 min and was directly related to the number of cells used. Degradation of labeled insulin, as measured by trichloroacetic acid precipitation, was related to the number of cells used, was not prevented by trasylol or phenylmethylsulfonyl fluoride (general proteolytic enzyme inhibitors), but was prevented by addition of 1 to 2% bovine serum albumin to the incubation medium. Specificity of insulisulin, and desoctapeptide insulin were capable of competing for insulin binding in an order of potency related to their relative biological activity; prolactin and glucagon were unable to compete for insulin binding. Scatchard analysis of the binding data demonstrated a curvilinear-plot; specific binding (over the concentration range of 10(-11) to 10(-10) M insulin) showed a high affinity (Kd approximately 1 to 3 X 10(-10) M), and the estimated number of sites was greater in tumors from diabetic animals than in tumors from intact animals or intact animals given insulin prior to sacrifice. Reversibility of insulin binding was studied by dissociation experiments; dissociation was enhanced in the presence of added unlabeled insulin compared to dissociation examined under conditions of "infinite" dilutions only. Maximum dissociation of bound insulin was observed in the presence of 10(-7) M unlabeled insulin, with less of an effect at lower or higher concentrations of added insulin (no effect seen at 10(-10) M insulin). Two techniques were investigated for separating cells from unbound labeled insulin; the procedure using centrifugation was found to be more efficient. Thus, in the R3230AC mammary adenocarcinoma, data obtained on saturability, reversibility, and specificity of insulin binding indicate the existence of an insulin receptor with properties similar to those found in normal cells.
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PMID:Identification and characterization of the insulin receptor in the R3230AC mammary adenocarcinoma of the rat. 13 40

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

BK virus (BKV), a human papovavirus, was inoculated iv into 3-week-old Syrian golden hamsters. Between 2 1/2 and 9 months after inoculation, 82% of the animals developed tumors. The induced neoplasms were ependymoma, carcinoma of the pancreatic islets, osteosarcoma, adenocarcinoma, angiosarcoma, angioma, lymphoma, and seminoma. Hypersecretion of insulin, glucagon, C-peptide, and calcitonin was detected in tumors of pancreatic islets. BKV etiology of tumors was supported by the following evidence: 1) No tumors with BKV-specific markers appeared in animals given injections of buffer, animals inoculated with BKV neutralized by anti-BKV-specific serum, or uninoculated controls; 2) BKV tumor (T) antigen was detected by immunofluorescence and complement fixation tests in tumors of animals inoculated with infectious BKV and in transplanted tumors; 3) antibodies to BKV T-antigen were detected in sera of animals bearing primary or transplanted tumors; 4) BKV could be activated by Sendai virus-mediated fusion of neoplastic cells with susceptible Vero cells; and 5) no endogenous hamster oncornaviruses were found in tumors.
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PMID:Ependymomas, malignant tumors of pancreatic islets, and osteosarcomas induced in hamsters by BK virus, a human papovavirus. 21 Dec 43

The clinicopathologic aspects of pancreatic islet cell adenocarcinoma in 6 dogs were compared. Diagnosis was based on insulin-glucose ratios in 5 dogs. Surgical excision of the tumor resulted in absence of clinical signs for at least 1 year in 3 dogs.
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PMID:Pancreatic islet cell adenocarcinoma: clinical and diagnostic features of six cases. 21 19


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