Biomedical subjects

J D Haag

Publications and source records attributed to J D Haag.

29 records · Page 2Linked to original sources

PubMed1994

Mammary carcinoma regression induced by perillyl alcohol, a hydroxylated analog of limonene.

The monoterpene perillyl alcohol has been shown to induce the regression of 81% of small mammary carcinomas and up to 75% of advanced mammary carcinomas initiated by 7,12-dimethylbenz(a)anthracene (DMBA) in the Wistar-Furth rat. Dietary perillyl alcohol was greater than 5 times more potent than the monoterpene limonene at inducing tumor regression. Perillyl alcohol is rapidly metabolized in the rat, as is limonene. Rats chronically fed perillyl alcohol had the same circulating plasma metabolites as rats fed limonene; however, the levels of these metabolites found in the plasma were higher for perillyl alcohol-fed rats. For example, rats given a 2% perillyl alcohol diet for 10 weeks had plasma levels of terpene metabolites of 0.82 mM whereas those fed a 10% limonene diet for the same period had blood levels of 0.27 mM. It thus appears that the increased potency of perillyl alcohol over limonene in causing tumor regression may be due at least in part to differences in the pharmacokinetics of these two monoterpenes. We feel that perillyl alcohol is a good candidate for clinical testing of anticancer efficacy in humans.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1994

Human metabolism of the experimental cancer therapeutic agent d-limonene.

d-Limonene has efficacy in preclinical models of breast cancer, causing > 80% of carcinomas to regress with little host toxicity. We performed a pilot study on healthy human volunteers to identify plasma metabolites of limonene and to assess the toxicity of supradietary quantities of d-limonene. Seven subjects ingested 100 mg/kg limonene in a custard. Blood was drawn at 0 and 24 h for chemistry-panel analysis and at 0, 4, and 24 h for limonene-metabolite analysis. On-line capillary gas chromatography/mass spectrometry (GC/MS) analysis indicated that at least five compounds were present at 4 h that were not present at time zero. Two major peaks were identified as the rat limonene metabolites dihydroperillic acid and perillic acid, and two minor peaks were found to be the respective methyl esters of these acids. A third major peak was identified as limonene-1,2-diol. Limonene was a minor component. At a dose of 100 mg/kg, limonene caused no gradable toxicity. Limonene is metabolized by humans and rats in a similar manner. These observations and the high therapeutic ratio of limonene in the chemotherapy of rodent cancers suggest that limonene may be an efficacious chemotherapeutic agent for human malignancies.

Adult↗

PubMed1993

ApcMin, a mutation in the murine Apc gene, predisposes to mammary carcinomas and focal alveolar hyperplasias.

ApcMin (Min, multiple intestinal neoplasia) is a point mutation in the murine homolog of the APC gene. Min/+ mice develop multiple intestinal adenomas, as do humans carrying germ-line mutations in APC. Female mice carrying Min are also prone to develop mammary tumors. Min/+ mammary glands are more sensitive to chemical carcinogenesis than are +/+ mammary glands. Transplantation of mammary cells from Min/+ or +/+ donors into +/+ hosts demonstrates that the propensity to develop mammary tumors is intrinsic to the Min/+ mammary cells. Long-term grafts of Min/+ mammary glands also gave rise to focal alveolar hyperplasias, indicating that the presence of the Min mutation also has a role in the development of these lesions.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1993

Increased mannose 6-phosphate/insulin-like growth factor II receptor and transforming growth factor beta 1 levels during monoterpene-induced regression of mammary tumors.

The monoterpenes represent a potentially new class of breast cancer therapeutic agents. We have shown that d-limonene induces the regression of advanced rat mammary adenocarcinomas. These regressing tumors have an increased cellular concentration of both the mannose-6-phosphate/insulin-like growth factor II receptors and transforming growth factor beta 1. The terpene-induced regression of mammary tumors may result in part from the mitoinhibitory and differentiation properties of active transforming growth factor beta 1. Furthermore, the activation of transforming growth factor beta 1 in these tumors is likely to be facilitated by the increased concentration of the mannose-6-phosphate/insulin-like growth factor II receptors in the mammary tumor cells. Tumors not responding to terpene therapy lacked a rise in the mannose-6-phosphate/insulin-like growth factor II receptor level which may relate to the fact that this gene is hemizygous due to maternal imprinting.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1992

Limonene-induced regression of mammary carcinomas.

Dietary administration of the monocyclic monoterpenoid d-limonene causes complete regression of both dimethylbenz[alpha]anthracene- and N-nitroso-N-methylurea-induced rat mammary carcinomas. Carcinomas regress when limonene is added to the diet either when the tumor is small and still capable of spontaneously regressing or when it is large and progressed beyond the stage when it is susceptible to spontaneous regression. The limonene dose-tumor regression response relationship is steep. Significant regressions are not observed at 5% dietary levels, while a majority of tumors completely regress above a 7.5% dietary level. Limonene appears to act in a cytostatic fashion. Its removal from the diet results in a significant number of tumor recurrences. Regressing tumors have a unique histopathological appearance that is not associated with gross cytotoxicity, immune cell involvement, or apoptosis. Preliminary analysis suggests a remodeling/redifferentiation event underlying regression. The underlying mechanism of action of limonene in causing tumor regression is unknown. However, it should be noted that limonene can selectively inhibit the isoprenylation of small G proteins. Monoterpenoids such as limonene represent a novel class of anticancer drugs with the potential to cause tumor regressions with limited toxicity.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1992

Mammary carcinoma suppressor and susceptibility genes in the Wistar-Kyoto rat.

The Copenhagen (Cop) rat carries a homozygous mammary carcinoma suppressor (MCS) gene that prevents both spontaneous and induced mammary cancer. Here we identify an additional rat strain, the Wistar-Kyoto (WKy), that is resistant to the development of mammary carcinomas. This rat strain is similar to Cop in having one homozygous copy of a mammary suppressor gene. The Cop MCS gene and the gene responsible for mammary cancer resistance in the WKy were found to be very closely linked genetically and thus are likely to be the same gene. It was found that, unlike the Cop strain, the WKy strain also carries multiple copies of a susceptibility gene(s). This is analogous to the susceptible Wistar-Furth strain, which carries three copies of dominant susceptibility genes. The MCS gene is epistatic in regard to these susceptibility genes. The availability of the WKy rat strain carrying MCS on a background independent of the Cop strain will aid both mechanistic studies and the molecular cloning of MCS.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1992

Chemoprevention of mammary carcinogenesis by hydroxylated derivatives of d-limonene.

The monoterpene d-limonene has been shown to an effective, non-toxic chemopreventive agent in mammary and other rodent tumor models. The studies reported here investigated structure-activity relationships among limonene and three hydroxylated derivatives in the prevention of dimethylbenz[a]anthracene (DMBA)-induced mammary cancer. Rats were fed control or 1% limonene, carveol, uroterpenol or sobrerol diets from 2 weeks before to one week after carcinogen administration. Carveol, uroterpenol and sobrerol significantly prolonged tumor latency and decreased tumor yield. Sobrerol was the most potent of the monoterpenes tested, decreasing tumor yield to half that of the control, a level previously achieved with 5% limonene diets. Excretion of radioactivity from [3H]DMBA was doubled in rats fed 5% limonene and nearly tripled in rats fed 1% sobrerol. Sobrerol is thus 5-fold more potent than limonene in both enhancing carcinogen excretion and in preventing tumor formation. These data demonstrate that hydroxylation of monoterpenes affects chemopreventive potential, with 2 hydroxyl groups greater than 1 greater than 0. Sobrerol, carveol and uroterpenol are novel cancer chemopreventive agents with little or no toxicity.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1991

A comparison of tocopherol and tocotrienol for the chemoprevention of chemically induced rat mammary tumors.

Two forms of vitamin E, tocopherol and tocotrienol, were tested for chemopreventive activity in two chemically induced rat mammary-tumor models. When mammary tumors were induced by 7,12-dimethylbenz(a)anthracene (DMBA, 50 mg/kg), only the tocotrienol group had a statistically significant increase in tumor latency. There was no effect of either compound on tumor multiplicity. When tumors were induced by N-nitrosomethylurea (NMU, 30 mg/kg), neither analogue of vitamin E modified latency, whereas tocotrienol increased tumor multiplicity. In summary, neither vitamin analog had a major impact on mammary-tumor development after tumor induction with either DMBA or NMU.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1991

Quantitating the frequency of initiation and cH-ras mutation in in situ N-methyl-N-nitrosourea-exposed rat mammary gland.

Mammary carcinogenesis is a multistep process consisting minimally of initiation and promotion/progression stages. The rate-limiting stage in the carcinogenesis process is undetermined but can in part be addressed by estimating the frequency of initiation, a heritable early event. Here, we use an in vivo limiting dilution transplantation assay to estimate initiation frequency in a rat mammary epithelial stem-like cell population that was exposed in situ to 50 mg/kg N-methyl-N-nitrosourea (NMU) administered i.v. We estimate that this dose resulted in the killing of 65% of exposed mammary cells. Known numbers of cells surviving NMU exposure were grafted into fat-pads of recipient rats in which the cells grew and differentiated into structurally and functionally normal mammary glands. Recipient rats were hormonally manipulated to provide maximal promotion of initiated cells. Mammary carcinomas developing at graft sites were quantitated over a 2-year period. Based on these results, we estimate that at least 1 surviving NMU-exposed mammary cell in 7,200 was initiated. Seventeen % of these graft site carcinomas had an activated H-ras oncogene with a G to A mutation in codon 12. This suggests that at least 1 mammary cell in 43,000 was mutated in this fashion by in situ exposure to NMU. These data suggest that cH-ras represents approximately 1 of 5 of the initiation events produced by NMU exposure of rat mammary glands.

Animals↗

PubMed1990

Reduction in the frequency of activated ras oncogenes in rat mammary carcinomas with increasing N-methyl-N-nitrosourea doses or increasing prolactin levels.

The role of c-Ha-ras-1 oncogene activation in the multistage biological process of N-methyl-N-nitrosourea (NMU)-induced mammary carcinogenesis was investigated. The average yield of NMU-induced mammary tumors in Wistar-Furth rats was altered by modification of either the initiation or promotion/progression stage of carcinogenesis. Initiation was varied by the use of different doses of NMU from 20 to 50 mg/kg. Tumor yield was increased with increasing NMU doses. However, the frequency of mammary tumors with activated c-Ha-ras-1 decreased in a linear fashion with increasing NMU doses. Promotion/progression was varied by increasing prolactin levels starting approximately 2 weeks after NMU administration. This hormonal manipulation increased tumor yield, while reducing the frequency of tumors with activated ras. It is postulated that ras activation represents one of several possible mechanisms by which NMU initiates mammary carcinogenesis. Furthermore, initiated cells without activated ras are more dependent on epigenetic promotional events provided by either prolactin or NMU than are ras-initiated cells.

Adrenalectomy↗

PubMed1990

Site of expression and biological function of the rat mammary carcinoma suppressor gene.

The rat mammary carcinoma suppressor (MCS) gene is an autosomal dominant gene found in the Copenhagen (Cop) rat that specifically prevents carcinogen-induced and spontaneous mammary carcinomas. Mammary cells from the Wistar-Furth (WF) rat, which do not carry the MCS gene, were grafted into ectopic sites in WF X Cop and WF X Fischer 344 hybrid rats. Only the former hybrid carried the MCS gene. These chimeric rats were then treated with 7,12-dimethylbenz[a]anthracene (DMBA) and the development of mammary carcinomas was followed. The results suggested that the main site of MCS activity was within the mammary parenchyma. However, a minor abscopal effect of this gene was also observed. Ectopic mixed mammary glands composed of a mixture of Cop and WF cells were also examined for susceptibility to DMBA-induced carcinogenesis. The presence of Cop cells did not inhibit tumor development from WF cells in these mixed glands. Finally, graft sites in which palpable tumors did not develop were examined for focal epithelial lesions. The MCS gene was found to inhibit completely the formation of microcarcinomas, but did not affect the development of alveolar hyperplasias.

9,10-Dimethyl-1,2-benzanthracene↗