Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0598934 (tumor growth)
 58,965 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nude mice bearing xenografts of MIA PaCa-2 human pancreatic cancer cell line were treated for 4 weeks with AN-51, a somatostatin octapeptide analog D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Thr-NH2 (RC-121) containing methotrexate attached to the alpha-amino group of D-Phe in position 1. Control groups of mice received saline, RC-121 or methotrexate. Drugs were given in equimolar doses by daily s.c. injections. After 7 days of treatment with 25 micrograms/day of AN-51, tumor growth was completely inhibited although the treatment had to be suspended because of toxic side effects, especially on the gastrointestinal tract, accompanied by major weight loss of the animals. Mice were allowed to recover for 1 week and treatment was continued with 12.5 micrograms/day AN-51. After 2 weeks of additional therapy, tumor volume, percentage change in tumor volume, and tumor weights were significantly decreased, compared with controls, only in the group treated with AN-51. Methotrexate and RC-121 also inhibited tumor growth, but their effects were not statistically significant. AN-51 retained its hormonal activity and decreased serum growth hormone levels in mice. Binding affinity of AN-51 for somatostatin receptors on MIA PaCa-2 cells was found to be 2.5-times lower than that of parent compound RC-121. This is the first report on inhibition of human pancreatic cancer growth in vivo by somatostatin analogs carrying cytotoxic radicals.
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PMID:Cytotoxic analog of somatostatin containing methotrexate inhibits growth of MIA PaCa-2 human pancreatic cancer xenografts in nude mice. 131 46

The effect of long-term administration of analogs of luteinizing hormone-releasing hormone (LH-RH) and somatostatin on the growth of the growth hormone (GH)- and prolactin (PRL)-secreting rat pituitary GH3 tumor was investigated. Daily administration of [D-Trp6]LH-RH (50 micrograms/day), early after inoculation of the GH3 tumor, inhibited tumor growth by more than 90% as compared to controls. Similarly, in two experiments, a single once-a-month injection of long-acting [D-Trp6]LH-RH microcapsules (in a dose calculated to release about 25 micrograms/day for 30 days) inhibited the growth of GH3 pituitary tumor by more than 50% 6 or 13 wk after transplantation, when the tumors were fully developed. Serum GH and PRL levels also were reduced markedly by treatment with [D-Trp6]LH-RH. On the other hand, the administration of an antagonistic analog of LH-RH, N-Ac-[D-Phe(4Cl)1,2, D-Trp3, D-Arg6, D-Ala10]LH-RH, did not significantly reduce the growth of this tumor, and the treatment with two different analogs of somatostatin, cyclo(Pro-Phe-D-Trp-Lys-Thr-Phe) and D-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-Thr NH2, appeared to enhance it. These results are in agreement with previous findings of growth inhibition of 7315a pituitary tumors with different hormone-secreting characteristics by agonistic analogs of LH-RH. The collective data from experimental work with rat pituitary tumor models support the contention that the use of [D-Trp6]LH-RH might be considered for the treatment of some patients with pituitary tumors who failed to respond to conventional therapy.
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PMID:Inhibition of growth of a prolactin and growth hormone-secreting pituitary tumor in rats by D-tryptophan-6 analog of luteinizing hormone-releasing hormone. 285 96

The combination of a long-acting delivery system for the agonist [D-Trp6]luteinizing hormone-releasing hormone ([D-Trp6]LH-RH) with modern somatostatin analogs was studied in the Dunning R-3327H rat prostate cancer model. Microcapsules of [D-Trp6]LH-RH releasing 25 micrograms/day were injected once a month. In the first experiment the adjunct was the somatostatin analog D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Thr-NH2 (RC-121), administered at a dose of 2.5 micrograms twice a day, and the therapy was continued for 70 days. Tumor volume was significantly decreased by [D-Trp6]LH-RH microcapsules or RC-121 given alone. The combination of microcapsules and analog RC-121 caused a greater inhibition of tumor growth than the single agents. Similar effects were seen when the percent increase in the tumor volume was examined. The inhibition of tumor growth caused by the [D-Trp6]LH-RH microcapsules was greater than that caused by RC-121. The combination of the two agents was again the most effective, resulting in the smallest increase in tumor volume. Tumor weights were much lower in the groups treated with microcapsules or RC-121 alone than in controls. The lowest tumor weights were obtained in the group that received the combination of [D-Trp6]LH-RH microcapsules and RC-121. Similar results were obtained in the second experiment, in which the animals were treated for a period of 83 days with microcapsules containing the somatostatin analog D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Trp-NH2 (RC-160) that released 5 micrograms/day and were injected twice a month alone or in combination with microcapsules of [D-Trp6]LH-RH. Microcapsules of analog RC-160 given alone significantly decreased tumor growth as measured by the final tumor volume, the percentage change from the initial tumor volume, and the reduction in tumor weight. The inhibition of tumor growth induced by [D-Trp6]LH-RH microcapsules was greater than that caused by RC-160. The most striking decrease in tumor weight and volume was obtained in animals treated with microcapsules of [D-Trp6]LH-RH combined with the delayed delivery system for RC-160. The overall response to the combination therapy could reflect the inhibition by somatostatin analogs of the proliferation of prostate cancer cells through a decrease in growth hormone and prolactin release and interference with endogenous growth factors, in addition to the main effect, which is the suppression by [D-Trp6]LH-RH of the growth of androgen-dependent tumor cells. Our results indicate that somatostatin analogs enhance the inhibitory effects of [D-Trp6]LH-RH on the growth of prostate tumors. The administration of somatostatin analogs in combination with microcapsules of [D-Trp6]LH-RH might improve clinical response in patients with advanced prostate carcinoma.
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PMID:Somatostatin analogs as adjuncts to agonists of luteinizing hormone-releasing hormone in the treatment of experimental prostate cancer. 289 Jan 64

An endocrinologically-potent octapeptide analogue of somatostatin (SRIF), 3-(2-naphthyl)-D-Ala-Cys-Tyr-D-Trp-Lys-Val-Cys-Thr-NH2 (BIM-23014 C), was examined for its ability to inhibit the in vitro and in vivo growth of the human small cell lung carcinoma (SCLC) line, NCI-H69. When cultured cells were implanted into athymic nude mice, treatment (500 micrograms/injection, twice daily) resulted in a prolongation of lag time for the appearance of measurable tumors, and there was a marked inhibition of the growth rate. Indeed, peptide injection in the region of the tumor resulted in a complete regression of the NCI-H69 tumors. Withdrawal of BIM-23014 C treatment resulted in an acceleration of tumor growth indicating an antiproliferative rather the oncolytic action. A similar inhibition of tumor growth was also observed when solid tumors obtained from the first implantation were used as the donor tissues. In cell culture, the proliferation in the presence of a low concentration (10nM) of BIM-23104 C was also significantly retarded suggesting a direct mechanism of action.
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PMID:In vitro and in vivo inhibition of human small cell lung carcinoma (NCI-H69) growth by a somatostatin analogue. 289 54

Mice were fed diets deficient in a single essential amino acid, and the primary immune responses to inoculation of allogenic tumor cells was measured by in vitro assay of cellular immunity. Moderate reduction of the amino acids phenylalanine-tyrosine, valine, threonine, methionine-cystine, isoleucine, and tryptophane in the diet produced profound depression of hemagglutinating and blocking antibody responses, although cytotoxic cell-mediated immunity remained intact. These diets had previously been shown to result in a selective depression of tumor growth in mice. Limitation of the amino acids arginine, histidine, and lysine in the diets gave rise to only slight depression of the immune responses. These diets had previously been shown to produce a proportional decrease in both tumor growth and host body weight. Moderate leucine restriction resulted in a paradoxical depression of cytotoxic cell-mediated immunity with little effect on serum blocking activity. Slight increases had previously been noted in the weight of tumors in mice fed leucine-restricted diets. Deficiency or imbalance of essential amino acids in the diet may produce profound depression of immune responses and apparent, marked changes in the immune resistance of the host animal to tumors.
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PMID:Quantitative effects of nutritional essential amino acid deficiency upon immune responses to tumors in mice. 468 18

Using animal models of acinar and ductal pancreatic cancer, we investigated the effect of analogs of hypothalamic hormones on tumor growth. In Wistar/Lewis rats bearing the acinar pancreatic tumor DNCP-322, chronic administration of [L-5-Br-Trp8]somatostatin-14 significantly decreased tumor weights and volume. Somatostatin-28 and the cyclic hexapeptide analog of somatostatin cyclo(Pro-Phe-D-Trp-Lys-Thr-Phe) failed to influence the growth of this tumor. The agonistic analog of luteinizing hormone-releasing hormone [D-Trp6]LH-RH also significantly decreased tumor weight and volume in this model and reduced testosterone levels and the weights of the ventral prostate and tests. In Syrian hamsters bearing ductal type of pancreatic carcinoma, chronic administration of [L-5-Br-Trp8]somatostatin diminished tumor weights and volume. The percentage change in tumor volume was significantly decreased when compared to control animals. In one experiment, cyclic hexapeptide of somatostatin also inhibited growth of this tumor. [D-Trp6]LH-RH, given twice daily or injected in the form of microcapsules for constant controlled release, significantly decreased tumor weight and volume and suppressed serum testosterone levels. Hamsters castrated 4 days after transplantation of the pancreatic tumors showed a significant decrease in weight and volume of these tumors. This suggests that pancreatic cancers may, at least in part, be sex hormone sensitive. [D-Trp6]LH-RH may decrease the growth of pancreatic carcinomas by suppressing androgens. Somatostatin analogs reduce the growth of pancreatic ductal and acinar cancers, probably by inhibiting the release or stimulatory action of gastrointestinal hormones on tumor cells (or both). Inhibition of animal models of pancreatic tumors by chronic administration of somatostatin analogs and [D-Trp6]LH-RH suggests that these compounds should be considered for the development of a new hormonal therapy for cancer of the pancreas.
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PMID:Inhibition of growth of pancreatic carcinomas in animal models by analogs of hypothalamic hormones. 614 60

Within the physiological range of other known releasing factors, human pancreatic tumor growth hormone releasing factor (hpGRF) is specific for GH release. Data concerning hpGRF action on cAMP and GH are consistent with the concept of cAMP acting as a second messenger for this releasing factor. hpGRF-stimulated GH release is Ca++ dependent. Exogenous hpGRF40 does not alter the interdigestive gastric motility or secretion of gastrin and motilin in dogs, while large doses of hpGRF stimulate somatostatin release into the hepatic portal blood of the rat. Significant GRF activity as determined by a rat pituitary perifusion system is confined within the median eminence and the arcuate nucleus, though detectable but insignificant GRF activity is present in other area of the hypothalamus and cortex in the rat. GRF activity is present in the ovine brain as well as in the gut. Both tissues contain large (between 4000-5000 daltons) and small (but possibly larger than 1000 daltons) m.w. GRF materials. GRF appears to be structurally different between species and more than one GRF may be present within the same species. One of the ovine brain peptides with GH-releasing activity was partially characterized as His-Ser-Asp-Gly-Ile-Phe-Thr-Asp-Ser-Tyr- Lys-Arg-Try-Asn-Lys-Glu-Met- Ala-Lys--which is similar to rat GRF and porcine VIP having His at the N-terminus. Another peptide with GRF activity which eluted earlier on reverse phase HPLC and later on cation exchange chromatography has also been obtained in a pure form.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Growth hormone releasing factors in the brain and the gut: chemistry, actions, and localization. 620 12

The intraperitoneal (i.p.) injection of tuftsin, Thr-Lys-Pro-Arg, into C57BL/6 mice that were injected with B16/5B melanoma cells, resulted in a considerable suppression and elimination of solid tumor growth. While 100% of control animals exhibited tumor growth, 38% of the treated animals failed to show tumor formation for the duration of the experiment, 60-80 days. The octapeptide, tuftsinyltuftsin, was effective at 3 ng per mouse as was a dose of 2 and 20 micrograms per mouse. In each case there was a significant number of mice free of tumors. The octapeptide was also quite effective against L1210 cells resulting in the survival of 35-40% of the treated animals. The lethal effect of increased superoxide, O X 2, production by tuftsin treatment may explain the antineoplastic effect of the tetrapeptide. This may result not only from higher concentrations of O X 2 but also from the potentially lethal effects of H2O2 and OH X radical, both of which are products of O X 2 metabolism.
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PMID:The antineoplastic effects of tuftsin and tuftsinyltuftsin on B16/5B melanoma and L1210 cells. 632 37

Recent studies have shown that inactivation of tumor suppressor p53 gene is a key point in the development of human carcinomas and that normal p53 protein acts as a "molecular policeman" monitoring the integrity of the genome. In the present study, a series of 22 primary human salivary gland carcinomas were examined for alterations and expression of the p53 gene by a combined molecular and immunohistochemical approach, polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP), direct gene sequencing and p53 protein immunostaining. In addition, in order to identify correlations between p53 abnormalities and genetic instability, DNA aneuploidy and tumor growth characteristics were analyzed by cytofluorometry and the AgNOR technique. Seven of the 22 cases displayed nuclear p53 overexpression as revealed by immunostaining with p53 monoclonal antibody (Do-7), and 2 of these 7 cases were associated with the presence of point mutations [codon 140: ACC (Thr)-->ATC (Ile), codon 175: CGC (Arg)-->CAC (His)] of the p53 gene. Twelve of the 22 cases were aneuploid on the DNA histogram, and this phenomenon was statistically correlated with the 7 cases exhibiting p53 nuclear accumulation. AgNOR staining, on the other hand, was not statistically correlated with p53 abnormalities. These findings support the view that abnormal nuclear accumulation of the p53 protein is correlated with genetic instability of human salivary gland carcinoma cells.
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PMID:[p53 abnormality in salivary gland carcinoma and its relation to tumor DNA aneuploidy and AgNOR]. 786

Integrins can trigger signals by activation of cytoplasmic tyrosine kinases, including pp125FAK. Preliminary evidence suggests that serine/threonine kinases such as ERKs may also be activated via integrins. Thus, there seems to be at least partial overlap between RTK signaling pathways and integrin signaling. In tumor cells, ectopic expression or over-expression of certain integrins such as alpha 5/beta 1 can result in reduced tumorigenesis. Presumably the effects of integrins on tumor growth are mediated by the integrin signaling pathway(s) involving FAK and ERKs. However, the precise mechanisms involved have not yet been elucidated.
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PMID:Integrin signals and tumor growth control. 898 69


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