Liver Biopsy Hydroxyproline Content Is a Diagnostic for Hepatocellular Carcinoma in Murine Models of Nonalcoholic Steatohepatitis

Abstract

There is increasing evidence that nonalcoholic steatohepatitis (NASH) is a risk factor for hepatocellular carcinoma (HCC) in the absence of cirrhosis, a phenomenon termed noncirrhotic HCC. Early diagnosis of HCC is critical to a favorable prognosis. We tested the hypothesis that hydroxyproline content of liver biopsy samples is diagnostic for HCC in murine models of NASH induced by diet or by diet and chemicals. The training set comprised mice fed a standard diet or a fast-food diet with or without administration of thioacetamide. At harvest, livers from the modified diet cohort exhibited NASH with a subset of NASH livers exhibiting HCC. Hydroxyproline content was measured in liver biopsy samples with tissue in the NASH+HCC cohort sampled from the remote, nontumor parenchyma. Plotting the receiver operating characteristics (ROC) with hydroxyproline as the continuous variable against the absence or presence of HCC yielded an area under ROC of 0.87, a threshold of >0.18 μg hydroxyproline/mg liver and sensitivity of 91% with a specificity of 83.3%. The use of liver hydroxyproline content as a diagnostic for HCC in a test set comprising healthy, NASH and NASH+HCC livers proved 87% accurate.

Collagen Characterization in a Model of Nonalcoholic Steatohepatitis with Fibrosis; A Call for Development of Targeted Therapeutics

“…In the present study, we tested the hypothesis that NASH with fibrosis is associated with upregulation of hepatic COL I and COL III, both of which are fibrillar collagens. Consistent with previous reports [ 4 , 5 , 6 ], livers from mice randomized to a FFD exhibited hallmark features of NASH with fibrosis, i.e., lipid deposition, inflammation, hepatocyte ballooning, increased serum AST and ALT, and matrix deposition. The novel finding in this study was increased hepatic col1a1, col1a2, and col3a1 accompanying NASH with fibrosis.…”

“…However, the risk associated with NAFLD is not merely limited to the need for transplantation but also includes the risk of developing HCC. In fact, a preponderance of experimental and clinical evidence suggests that increased scar deposition in the liver is associated with transformation of the liver to a cancerous phenotype [ 4 , 5 , 6 , 12 , 13 , 14 , 15 , 16 ]. In murine models of NASH, livers with the highest hydroxyproline content, a component of collagen, exhibited evidence of HCC [ 4 , 6 ].…”

“…In murine models of NASH, livers with the highest hydroxyproline content, a component of collagen, exhibited evidence of HCC [ 4 , 6 ]. In fact, in these models liver hydroxyproline content was diagnostic for HCC [ 6 ]. Clinically, cirrhotics are at highest risk for HCC.…”

“…Spurred by the diabetes and metabolic syndrome crises, the prevalence of nonalcoholic fatty liver disease (NAFLD) in the United States alone is estimated at 80–100 million individuals [ 1 , 2 , 3 ]. Left untreated, NAFLD can progress from simple steatosis to nonalcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and hepatocellular carcinoma (HCC) [ 1 , 4 , 5 , 6 ]. It is estimated that 8–10 million people in the United States present with NASH and 2–5 million NASH with fibrosis [ 1 ].…”

“…A therapeutic effective in a given patient might prove ineffective in other patients. A number of reports indicate that deposition of extracellular matrix, i.e., scarring or fibrosis, in the setting of NASH is associated with progression to cirrhosis and/or HCC [ 4 , 5 , 6 , 12 , 13 , 14 , 15 , 16 ]. Identification of transcriptional elements together with identification of the nature of the matrix deposited might yield strategies to more effectively mitigate disease progression.…”