indinavir-sulfate and Carcinoma--Hepatocellular

Accumulating evidences show a higher incidence of hepatic neoplasm in HIV/hepatitis C virus (HCV)-coinfected individuals compared with HCV-monoinfected patients. Treatment with HIV-1 protease inhibitors inhibited cancer-promoted angiogenesis in HIV-infected patients affected by Kaposi sarcoma. We aimed to evaluate the antineoplastic potential activities of the protease inhibitor indinavir (Crixivan) in in vitro and in vivo hepatocarcinoma models.. We analyzed effects of indinavir on cell growth and invasiveness in Huh7 and SK-HEP-1 hepatocarcinoma cell lines and on in vivo tumor growth of the same cells in nude mice. Morphologic and molecular analyses on explanted tumors were carried out to evaluate vascularization and apoptosis.. We observed a reduced ability to invade an in vitro extracellular matrix for both cell lines treated with indinavir compared with controls (P = 0,001). Moreover, indinavir treatment was able to inhibit matrix metalloproteinase-2 proteolytic activation, whereas there was no effect on cell proliferation. The drug was also able to delay in vivo tumor growth. The inhibition of tumor growth was statistically significant from days 6 to 21 (P = 0.004 and P = 0.003, respectively). Moreover, the drug showed antiangiogenic and proapoptotic actions, as revealed by vessel count and apoptotic index by terminal deoxynucleotide transferase-mediated nick end labeling in explanted tumors. Finally, treatment with indinavir did not block the production of vascular endothelial growth factor in the tumors.. Indinavir could be helpful to prevent the development of hepatocarcinomas in HIV/HCV-coinfected individuals. In view of the current trend to substitute protease inhibitors with other antiretroviral agents, this information may have clinical implications.

Topics: Angiogenesis Inhibitors; Animals; Antineoplastic Agents; Apoptosis; Blotting, Western; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Survival; Drug Evaluation, Preclinical; Enzyme Activation; HIV Protease Inhibitors; Humans; In Situ Nick-End Labeling; Indinavir; Liver Neoplasms, Experimental; Male; Matrix Metalloproteinase 2; Mice; Mice, Nude; Vascular Endothelial Growth Factor A; Xenograft Model Antitumor Assays

HIV protease inhibitor treatment is associated with insulin resistance. We have recently demonstrated that the HIV protease inhibitor indinavir influences initial insulin signaling steps in HepG2 cells. Here we investigated in the same cell model whether indinavir alters insulin-stimulated glycogen synthesis. Since an altered phosphotyrosine phosphatase activity could represent a mechanism by which insulin signaling is influenced, we also assessed potential indinavir effects on protein tyrosine phosphatase activity directed against tyrosine phosphorylated insulin receptor substrate-1. HepG2 cells were incubated for 48 h without or with indinavir (100 micro mol/l). Subsequently, the insulin-stimulated incorporation of 14C-glucose into glycogen was measured. In indinavir-treated cells the insulin effect on glycogen synthesis was reduced by 30 +/- 4.5 %. Dephosphorylation of immobilized tyrosine-phosphorylated insulin-receptor substrate-1 by the cell extracts was determined using a microwell plate-based method, and indinavir treatment did not alter this dephosphorylation. In conclusion, our data suggest that indinavir affects insulin-stimulation of glycogen synthesis in liver cells, and this may be related to the previously observed alterations in insulin signaling. Direct effects of indinavir on the GLUT4 transport system, that have been suggested from data in other cell systems, are unlikely in HepG2 cells that express no or almost no GLUT4 transport system. Finally, our data do not support the hypothesis that indinavir alters insulin signaling by influencing protein tyrosine phosphatase activity directed against insulin receptor substrate-1.

Topics: Carcinoma, Hepatocellular; Glucose; Glycogen; HIV Protease Inhibitors; Humans; Hypoglycemic Agents; Indinavir; Insulin; Liver; Liver Neoplasms; Protein Tyrosine Phosphatases; Stimulation, Chemical; Tumor Cells, Cultured

Indinavir is a viral protease inhibitor used for the treatment of HIV infection. Unconjugated hyperbilirubinemia develops in up to 25% of patients receiving indinavir, prompting drug discontinuation and further clinical evaluation in some instances. We postulated that this side-effect is due to indinavir-mediated impairment of bilirubin UDP-glucuronosyltransferase (UGT) activity and would be most pronounced in individuals with reduced hepatic enzyme levels, as occurs in approximately 10% of the population manifesting Gilbert's syndrome. This hypothesis was tested in vitro, in the Gunn rat model of UGT deficiency, and in HIV-infected patients with and without the Gilbert's polymorphism. Indinavir was found to competitively inhibit UGT enzymatic activity (K(I) = 183 microM) while concomitantly inducing hepatic bilirubin UGT mRNA and protein expression. Although oral indinavir increased plasma bilirubin levels in wild-type and heterozygous Gunn rats, the mean rise was significantly greater in the latter group of animals. Similarly, serum bilirubin increased by a mean of 0.34 mg/dl in indinavir-treated HIV patients lacking the Gilbert's polymorphism versus 1.45 mg/dl in those who were either heterozygous or homozygous for the mutant allele. Whereas saquinavir also competitively inhibits UGT activity, this drug has not been associated with hyperbilirubinemia, most likely because of the higher K(I) (360 microM) and substantially lower therapeutic levels as compared with indinavir. Taken together, these findings indicate that elevations in serum-unconjugated bilirubin associated with indinavir treatment result from direct inhibition of bilirubin-conjugating activity.

Topics: Animals; Bilirubin; Carcinoma, Hepatocellular; Glucuronosyltransferase; HIV Infections; HIV Protease Inhibitors; Hyperbilirubinemia; Indinavir; Male; Rats; Rats, Gunn; Rats, Wistar

Patients treated with human immunodeficiency virus-1 protease inhibitors often develop impaired glucose tolerance or diabetes, most likely due to an induction of insulin resistance. We therefore investigated whether the protease inhibitor indinavir alters insulin signalling.. We incubated HepG2 cells for 48 h without or with indinavir (100 micromol/l). Subsequently 125I-insulin binding to the cells and the effects of insulin stimulation on insulin-receptor substrate-1-phosphorylation, association of phosphatidylinositol 3-kinase with insulin-receptor substrate-1 and Akt-Thr308-phosphorylation were measured.. In cells not exposed to indinavir, insulin (100 nmol/l) led to rapid increases of insulin-receptor substrate-1-phosphorylation, association of phosphatidylinositol 3-kinase with insulin-receptor substrate-1 and Akt-phosphorylation during the first 75 s, followed by subsequent decreases. In indinavir-treated cells, these insulin-stimulated increases during the first 75 s were reduced by 30-60% and this was not associated with alterations in cell number or viability, insulin binding to the cells or cellular insulin-receptor substrate-1-content.. Effects of indinavir on initial insulin signalling could cause, or contribute to, the metabolic effects of human immunodeficiency virus-1 protease inhibitors.

Topics: Carcinoma, Hepatocellular; Cell Survival; HIV Protease; HIV Protease Inhibitors; Humans; Indinavir; Insulin; Insulin Receptor Substrate Proteins; Kinetics; Liver Neoplasms; Phosphoproteins; Phosphorylation; Receptor, Insulin; Signal Transduction; Tumor Cells, Cultured