title: Rapid induction of orthotopic hepatocellular carcinoma in immune-competent rats by non-invasive ultrasound-guided cells implantation.
abstract: BACKGROUND
  The fact that prognoses remain poor in patients with advanced hepatocellular carcinoma highlights the demand for suitable animal models to facilitate the development of anti-cancer medications. This study employed a relatively non-invasive approach to establish an orthotopic hepatocellular carcinoma model in immune-competent rats. This was done by ultrasound-guided implantation of cancer cells and the model was used to evaluate the therapeutic efficacy of short-term and low-dose epirubicin chemotherapy.
  
  
  METHODS
  Rat Novikoff hepatoma cells were injected percutaneously into the liver lobes of Sprague-Dawley rats under the guidance of high resolution ultrasound. The implantation rate and the correlation between dissected and ultrasound-measured tumor sizes were evaluated. A similar induction procedure was performed by means of laparotomy in a different group of rats. Pairs of tumor measurement were compared by ultrasound and computerized tomography scan. Rats with a successful establishment of the tumor were divided into the treatment (7-day low-dose epirubicin) group and the control group. The tumor sizes were non-invasively monitored by the same ultrasound machine. Blood and tumor tissues from tumor-bearing rats were examined by biochemical and histological analysis respectively.
  
  
  RESULTS
  Ultrasound-guided implantation of Novikoff hepatoma cells led to the formation of orthotopic hepatocellular carcinoma in 60.4% (55/91) of the Sprague-Dawley rats. Moreover, tumor sizes measured by ultrasound significantly correlated with those measured by calipers after sacrificing the animals (P < 0.00001). The rate of tumor induction by ultrasound-guided implantation was comparable to that of laparotomy (55/91, 60.4% vs. 39/52, 75%) and no significant difference in sizes of tumor was noted between the two groups. There was a significant correlation in tumor size measurement by ultrasound and computerized tomography scan. In tumor-bearing rats, short-term and low-dose epirubicin chemotherapy caused a significant reduction in tumor growth, and was found to be associated with enhanced apoptosis and attenuated proliferation as well as a decrease in the microvessel density in tumors.
  
  
  CONCLUSIONS
  Ultrasound-guided implantation of Novikoff hepatoma cells is an effective means of establishing orthotopic hepatocellular carcinoma in Sprague-Dawley rats. Short-term and low-dose epirubicin chemotherapy had perturbed tumor progression by inducing apoptosis and neovascularization blockade.
authors.affiliation: Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan.
authors.forename: Hoi-Hung
authors.initials: HH
authors.lastname: Chan
authors.forename: Tian-Huei
authors.initials: TH
authors.lastname: Chu
authors.forename: Hsin-Fan
authors.initials: HF
authors.lastname: Chien
authors.forename: Cheuk-Kwan
authors.initials: CK
authors.lastname: Sun
authors.forename: E-Ming
authors.initials: EM
authors.lastname: Wang
authors.forename: Huay-Ben
authors.initials: HB
authors.lastname: Pan
authors.forename: Hsiao-Mei
authors.initials: HM
authors.lastname: Kuo
authors.forename: Tsung-Hui
authors.initials: TH
authors.lastname: Hu
authors.forename: Kwok-Hung
authors.initials: KH
authors.lastname: Lai
authors.forename: Jiin-Tsuey
authors.initials: JT
authors.lastname: Cheng
authors.forename: Ming-Hong
authors.initials: MH
authors.lastname: Tai
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000627:therapeutic use; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy / Q000209:etiology* / Q000473:pathology*; D002460:Cell Line; D045744:Cell Line, Tumor; D017690:Cell Transplantation / Q000379:methods*; D004195:Disease Models, Animal; D018450:Disease Progression; D004305:Dose-Response Relationship, Drug; D015251:Epirubicin / Q000627:therapeutic use; D005240:Feasibility Studies; D007121:Immunocompetence; D008113:Liver Neoplasms / Q000188:drug therapy / Q000209:etiology* / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014463:Ultrasonography
chemical_list: D000903:Antibiotics, Antineoplastic; D015251:Epirubicin