Confirmation of drug delivery after liver chemoembolization: direct tissue doxorubicin measurement by UHPLC-MS-MS.

Because liver cancer is rarely suitable for surgery, transcatheter arterial chemoembolization (TACE) is used for palliative therapy. In this procedure, an emulsion of doxorubicin in iodized oil is injected directly into liver tumors through a catheter positioned within the artery supplying blood flow to the tumor. At present, there is limited understanding of factors affecting the delivery and dispersion of doxorubicin within treated tumors during TACE. This study addresses the development and application of an ultrahigh-pressure liquid chromatography-tandem mass spectrometry (UHPLC-MS-MS) method for rapid confirmation of drug delivery after TACE in a rabbit VX2 liver cancer model. Doxorubicin levels in liver tumors were measured using UHPLC-MS-MS and compared with computed tomography measured levels of iodized oil, a metric used clinically to indicate drug delivery. We found that tissue drug levels determined using UHPLC-MS-MS did not correlate with the regional iodized oil concentration (vehicle) within tumors following TACE, suggesting that chemotherapeutic drugs like doxorubicin spread throughout tumors, and that lack of iodized oil staining in portions of a tumor does not necessarily indicate inadequate therapy during TACE.

Effect of A-L tonic capsule on DNA content in rat experimental hepatocarcinogenesis.

The effects of A-L tonic capsule on DNA content in rat experimental hepatocarcinogenesis induced by diethylnitrosamine (DENA) were observed. The experimental rats were divided into 4 groups. With exception of group D in which the rats were only administered with DENA, the rats in the groups A, B, C were previously, simultaneously and subsequently fed with A-L tonic capsule respectively while they were administered with DENA. The DNA content of all rat livers was measured using automatic image analysis technique 20 weeks after administration of DENA. The results showed that the highest and lowest DNA contents were respectively seen in the groups D and A. There was significant difference in DNA contents between the groups A or B or C and D, and also between the groups A and B or C (both P < 0.01). 4 components (4C) and > or = 5C cells were predominant in the group D, while 2C cells were the minority. The number of 2C cells in the groups A, B, C was significantly higher than that in the group D, and the number of > or = 5C cells in the groups A, B, C was markedly lower than that in the group D (P < 0.01). Also, there was very significant difference in the number of 2C and > or = 5C cells between group A and B or C (P < 0.01). It was concluded that A-L tonic capsule could effectively inhibit the increase of DNA content of hepatocytes and improve the distribution of DNA content in rat hepatocarcinogenesis, especially in group A.

Low in vivo toxicity of a novel cisplatin-ursodeoxycholic derivative (Bamet-UD2) with enhanced cytostatic activity versus liver tumors.

Cisplatin-bile acid derivatives belonging to the Bamet-family maintain both liver organotropism and cytostatic activity. "In vivo" toxicity and usefulness as chemotherapeutic agent versus liver tumors of a novel drug, Bamet-UD2 [cis-diamminechlorocholylglycinate platinum (II)], with enhanced "in vitro" cytostatic activity was investigated. Using orthotopically implanted mouse Hepa 1-6 hepatoma in the liver of Nude mice, the antitumor effect of Bamet-UD2 was compared with that of a previously characterized compound of this family, Bamet-R2 [cis-diamminebis-ursodeoxycholate platinum(II)], and cisplatin. Life span was significantly prolonged in mice treated with both Bamets (Bamet-UD2 > Bamet-R2), compared with animals receiving saline or cisplatin. All these drugs inhibit tumor growth (Bamet-UD2 = cisplatin > Bamet-R2). However, toxicity-related deaths only occurred under cisplatin treatment. Using rats maintained in metabolic cages, organ-specific toxicity and drug accumulation in tissues were investigated. The amount of both Bamets in the liver was severalfold higher than that of cisplatin. By contrast, a significantly higher amount of cisplatin in kidney and nerve was found. In lung, heart, muscle, brain, and bone marrow the amount of drug was small and also significantly lower in animals receiving Bamets. Signs of neurotoxicity (altered nerve conduction velocity), nephrotoxicity (increased serum urea and creatinine concentrations and decreased creatinine clearance), and bone marrow toxicity (decreased platelet and white blood counts) in animals treated with cisplatin but not with the Bamets were found. These results indicate that, owing to strong antitumor activity together with absence of side effects, Bamet-UD2 may be useful in the treatment of liver tumors.

Effect of dietary lipid on gamma-glutamyl transferase-positive foci during hepatocarcinogenesis in rats.

The effect of dietary lipid on gamma-glutamyl transferase-positive (GGT-positive) foci was investigated. Female Sprague-Dawley rats were dosed with diethylnitrosamine (15 mg/kg) at 24 h of age. After weaning, they were fed nutritionally complete semipurified diets for 3 months. Rats fed 15% corn oil had significantly lower hepatic phospholipid eicosapentaenoate and docosahexaenoate than rats fed 7.5% corn oil plus 7.5% fish oil, 5% corn oil plus 10% fish oil (P < 0.05). However, rats fed 15% corn oil had significantly greater hepatic phospholipid arachidonate than rats fed the other two diets (P < 0.05), suggesting that n-3 polyunsaturated fatty acids were incorporated into hepatic phospholipid at the expense of n-6 polyunsaturated fatty acids. Hepatic PGF2alpha content was significantly greater in rats fed 15% corn oil than in rats fed the other two diets (P < 0.05). Rats fed fish oil had significantly lower hepatic vitamin E content than rats fed corn oil (P < 0.05). Hepatic lipid peroxidation (TBARS) tended to increase with increased dietary fish oil (P < 0.05). Dietary lipid did not influence GGT-positive foci area or number. In conclusion, dietary lipid affected hepatic PGF2alpha production, however, showed no effect on GGT-positive foci area and number. This may suggest that PGF2alpha is not the underlying mechanism for GGT-positive foci during hepatocarcinogenesis.

Effect of Vicia faba and bran feeding on nitrosamine carcinogenesis and formation.

The goal of this work was to study the effect of the most common Egyptian food items, Vicia faba beans (VF) and bran, on the carcinogenicity of dibutylnitrosamine (DBN) precursors (dibutylamine and nitrite). Mice receiving DBN precursors showed a delayed gain in body weight as well as decreased protein level and 5-nucleotidase activity. Acid ribonuclease, alkaline phosphatase, and DNA level and rate of synthesis were significantly increased compared with corresponding controls. Hepatomas and bladder papillomas developed in 60% and 40% of mice, respectively, after nine months of treatment. On the other hand, administration of VF or bran, in addition to DBN precursors, lessened the damage caused by DBN precursors alone, except DNA level and rate of synthesis were elevated. Alkaline phosphatase was also elevated when bran was administered with DBN precursors. However, these elevations were still less than corresponding elevations in mice receiving DBN precursors alone. The incidence of hepatoma was also reduced to only 20% for both groups. Meanwhile, incidence of bladder papillomas was only 20% in mice receiving VF in addition to DBN precursors, and bladder papillomas were completely absent in mice receiving bran in addition to DBN precursors. In vitro studies were also performed to clarify the effect of VF or bran on diphenylnitrosamine (DPhNA) and its formation from its precursors (diphenylamine and nitrite). The study revealed that VF and bran have the ability to eliminate nitrite and DPhNA from the reaction media and to reduce the rate of formation of DPhNA from its precursors. This reaction depends on the concentration and form of VF or bran and the duration of the reaction. Thus it is concluded that some naturally occurring food items, such as VF and bran, could protect humans against the hazardous effect of nitrosamines and their precursors.

Tumor promotion as a target for estrogen/antiestrogen effects in rat hepatocarcinogenesis.

Tamoxifen is a well-tolerated palliative and adjuvant treatment for human breast cancer and requires continuous, long-term administration for optimal therapeutic effectiveness. A two-stage model of experimental hepatocarcinogenesis, based upon the natural history of cancer development, has been employed to assess the carcinogenic potential of tamoxifen. In this study, the effectiveness of tamoxifen both as an initiator and a promoter in hepatocarcinogenesis was assessed in female F-344 rats. Tamoxifen was tested as an initiator at a single intragastric dose of 40 mg/kg, followed by promotion with 0.05% phenobarbital. The number and size of the resulting altered hepatic lesions were quantified, and tamoxifen was found to lack initiating action at the dose tested. Other groups of animals were initiated with a nonnecrogenic, subcarcinogenic dose of diethylnitrosamine (10 mg/kg) and were fed tamoxifen at either 250 or 500 mg/kg in the AIN-76A purified diet for 6 months. The livers of these animals showed an increase in the size and number of altered hepatic lesions compared with those animals that were initiated but not exposed to tamoxifen; this indicates that tamoxifen acts as a tumor promoter in the rat liver. The promotion index of tamoxifen, a measure of relative potency, was less than one-tenth that of ethinyl estradiol and more than four times that of phenobarbital, an agent commonly employed as a representative promoting agent in experimental carcinogenesis. Since tamoxifen lacked initiating activity in the rat liver at the dose tested, the mechanism of tumor induction in long-term feeding studies by tamoxifen may be due to its promotion of spontaneously initiated hepatocytes. The chronic therapeutic use of tamoxifen should therefore be limited by the potential carcinogenic risk of this agent as an effective tumor promoter.

Synthetic estrogens and tamoxifen as promoters of hepatocarcinogenesis.

Previously, we demonstrated that the synthetic estrogens mestranol and ethinyl estradiol (EE) were strong promoters of hepatocarcinogenesis initiated in intact female rats by prior treatment with diethylnitrosamine (J. D. Yager, H. A. Campbell, D. S. Longnecker, B. D. Roebuck, and M. C. Benoit, Cancer Res. 1984; 44:3862-3869). In subsequent studies designed to elucidate possible mechanisms of promotion by EE, we investigated whether the antiestrogen tamoxifen was antagonistic to the effects of EE (J. D. Yager, B. D. Roebuck, T. L. Paluszcyk, and V. A. Memoli, Carcinogenesis 1986; 7:2007-2014). In these and more recent studies we found that tamoxifen inhibited the stimulatory effects of EE on pituitary size, liver DNA synthesis, and, in cultured hepatocytes, the potentiation by EE of epidermal growth factor-induced DNA synthesis. Furthermore, tamoxifen also inhibited the ability of EE to promote hepatocarcinogenesis. However, paradoxically, tamoxifen alone enhanced the appearance of gamma-glutamyl transpeptidase positive foci in diethylnitrosamine-initiated livers indicating that it is a promoter of hepatocarcinogenesis.