Intraarterial hepatic chemotherapy with fluorouracil, fluorodeoxyuridine, mitomycin C, cisplatin or methotrexate as single-agent anticancer drugs for a transplanted experimental liver tumor in rats

Quimioembolização transarterial hepática: modelo experimental de tumor em ratos

OBJETIVO: Estabelecer um modelo de tumor no fígado de ratos para estudo do comportamento tumoral e avaliar o uso da quimiembolização transarterial. MÉTODOS: Utilizou-se oitenta e oito ratos Wistar, fêmeas, adultos, pesando entre 175- 284 g . Realizado incisão abdominal de 3 cm e implantou-se o carcinossarcoma de Walker 256 no lóbulo esquerdo do fígado. Dividiu-se em três grupos que receberam respectivamente 100x 10³ , 200x 10³ e 300x 10³ células tumorais, avaliado a pega do tumor e a sobrevida. Em outro grupo de experimento com 39 animais inoculados com tumor de Walker foi avaliado a sobrevida dos animais após infusão do 5-Flourouracil (5-FU) por via intra-peritoneal e intra-arterial. RESULTADOS: O implante do carcinossarcoma de Walker no fígado de ratos apresentou desenvolvimento de 100 %, teve um crescimento rápido e desenvolvimento de metástases tardiamente, levando os animais ao óbito entre o sétimo e décimo quinto dia. A quimiembolização transarterial é possível de ser realizada experimentalmente. O uso do 5-FU aumentou a sobrevida em comparação ao grupo controle. CONCLUSÃO: O modelo de implante do tumor de Walker no fígado de ratos é eficiente, de fácil reprodutibilidade, e sobrevida média de 9,96±0.3 dias. A quimioterapia transarterial hepática pode ser realizada experimentalmente para avaliar diversas drogas.

Regression of Novikoff rat hepatocellular carcinoma following locoregional administration of a novel formulation of clofazimine in lipiodol

We report here that, clofazimine (CFZ) treatment (0.1-10 microM) led to inhibition of in vitro proliferation of hepatocellular carcinoma (HCC) cell lines Hep3-beta, HuH-7, HepG2, SKHEP-1, PLC/PRF-5 and Novikoff. A 24 h exposure of human HuH-7 cells to various concentrations of CFZ dissolved in lipiodol (CFZ-L 10-160 microM), followed by 4 days treatment with medium alone, also led to dose-dependant inhibition of post-treatment cell growth. In vivo, direct intratumoural and intrahepatic arterial injection (IHA) of CFZ-L led to profound inhibition of orthotopic growth of rat Novikoff liver tumours (P < 0.0001 and P < 0.005, respectively). On the contrary, daily oral administration of 150 mg/kg CFZ for 7 days, did not influence the rate of Novikoff tumour growth. Histological examination of rat tumours, revealed the presence of lipiodol in tumour cells, 7 days after treatment with a single IHA dose. Histopathology did not show any abnormality in liver, lung or bowel sections taken from animals 1 week after IHA administration of CFZ-L. Similarly, liver function tests were all normal compared to saline treated animals. Deoxynucleotidyl transferase-mediated deoxyuridinetriphosphate nick end-labelling revealed the presence of large numbers of apoptotic cells in the CFZ-L treated tumours. Thus, intraarterial administration of the highly lipophilic antiproliferative agent CFZ in lipiodol solution may represent an effective and yet safe strategy for the regional treatment of HCCs.

An implantable rat liver tumor model for experimental transarterial chemoembolization therapy and its imaging features

AIM: To establish an ideal implantable rat liver tumor model for interventional therapy study and examine its angiographic signs and MRI, CT features before and after embolization.

METHODS: Forty male Wistar rats were implanted with Walker-256 tumor in the left lateral lobe of liver. Digital subtraction angiography (DSA) and transarterial chemoembolization were performed on day 14 after implantation. Native computer tomography (CT, n = 8) and native magnetic resonance (MR, n = 40) were performed between the day 8 and day 21 after implantation. The radiological morphological characteristics were correlated with histological findings.

RESULTS: Successful implantation was achieved in all forty rats, which was confirmed by CT and MRI. MR allowed tumor visualization from day 8 while CT from day 11 after implantation. The tumors were hypodensity on CT, hypointense on MR T1-weighted and hyperintense on T2-weighted. The model closely resembled human hepatocarcinoma in growth pattern and the lesions were rich in vasculature on angiography and got its filling mainly from the hepatic artery. Before therapy, tumor size was 211.9 ± 48.7 mm³. No ascites, satellite liver nodules or lung metastasis were found. One week after therapy, tumor size was 963.6 ± 214.8 mm³ in the control group and 356.5 ± 78.4 mm³ in TACE group. Ascites (4/40), satellite liver nodules (7/40) or lung metastasis (3/40) could be seen on day 21.

CONCLUSION: Walker-256 tumor rat model is suitable for the interventional experiment. CT and MRI are helpful in animal optioning and evaluating experimental results.