Contrast enhancement of the brain by folate-conjugated gadolinium-diethylenetriaminepentaacetic acid-human serum albumin nanoparticles by magnetic resonance imaging.

Different from regular small molecule contrast agents, nanoparticle-based contrast agents have a longer circulation time and can be modified with ligands to confer tissue-specific contrasting properties. We evaluated the tissue distribution of polymeric nanoparticles (NPs) prepared from human serum albumin (HSA), loaded with gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) (Gd-HSA-NP), and coated with folic acid (FA) (Gd-HSA-NP-FA) in mice by magnetic resonance imaging (MRI). FA increases the affinity of the Gd-HSA-NP to FA receptor-expressing cells. Clinical 3 T MRI was used to evaluate the signal intensities in the different organs of mice injected with Gd-DTPA, Gd-HSA-NP, or Gd-HSA-NP-FA. Signal intensities were measured and standardized by calculating the signal to noise ratios. In general, the NP-based contrast agents provided stronger contrasting than Gd-DTPA. Gd-HSA-NP-FA provided a significant contrast enhancement (CE) in the brain (p  =  .0032), whereas Gd-DTPA or Gd-HSA-NP did not. All studied MRI contrast agents showed significant CE in the blood, kidney, and liver (p < .05). Gd-HSA-NP-FA elicited significantly higher CE in the blood than Gd-HSA-NP (p  =  .0069); Gd-HSA-NP and Gd-HSA-NP-FA did not show CE in skeletal muscle and gallbladder; Gd-HSA-NP, but not Gd-HSA-NP-FA, showed CE in the cardiac muscle. Gd-HSA-NP-FA has potential as an MRI contrast agent in the brain.

Reduced efficacy of the Plk1 inhibitor BI 2536 on the progression of hepatocellular carcinoma due to low intratumoral drug levels.

Highly promising preclinical data obtained in cultured cells and in nude mice bearing xenografts contrast with the rather modest clinical efficacy of Polo-like kinase 1 (Plk1) inhibitors. In the present study, we investigated if Plk1 might be a suitable target in hepatocellular carcinoma (HCC) and if a genetically engineered mouse tumor model that well reflects the tumor cell and micro-environmental features of naturally occurring cancers might be suitable to study anti-Plk1 therapy. Analysis of Plk1 expression in human HCC samples confirmed that HCC express much higher Plk1 levels than the adjacent normal liver tissue. Inhibition of Plk1 by an adenovirus encoding for a short hairpin RNA against Plk1 or by the small-molecule inhibitor BI 2536 reduced the viability of HCC cell lines and inhibited HCC xenograft progression in nude mice. Treatment of transforming growth factor (TGF) α/c-myc bitransgenic mice with BI 2536 during hepatocarcinogenesis reduced the number of dysplastic foci and of Ki-67-positive cells within the foci, indicating diminished tumorigenesis. In contrast, BI 2536 had no significant effect on HCC progression in the transgenic mouse HCC model as revealed by magnetic resonance imaging. Measurement of BI 2536 by mass spectrometry revealed considerably lower BI 2536 levels in HCC compared with the adjacent normal liver tissue. In conclusion, low intratumoral levels are a novel mechanism of resistance to the Plk1 inhibitor BI 2536. Plk1 inhibitors achieving sufficient intratumoral levels are highly promising in HCC treatment.

Gadoxetate acid-enhanced MRI of hepatocellular carcinoma in a c-myc/TGFα transgenic mouse model including signal intensity and fat content: initial experience.

Genetically engineered mouse models, such as double transgenic c-myc/TGFα mice, with specific pathway abnormalities might be more successful at predicting the clinical response of hepatocellular carcinoma (HCC) treatment. But a major drawback of the tumour models is the difficulty of visualizing endogenously formed tumours. The optimal imaging procedure should be brief and minimally invasive. Magnetic resonance imaging (MRI) satisfies these criteria and gadoxetate acid-enhanced MRI improves the detection of HCC. Fat content is stated to be an additional tool to help assess tumour responses, for example, in cases of radiofrequency ablation. Therefore the aim of this study was to investigate if gadoxetate acid-enhanced MRI could be used to detect HCC in c-myc/TGFα transgenic mice by determining the relation between the signal intensity of HCC and normal liver parenchyma and the corresponding fat content as a diagnostic marker of HCC. In our study, 20 HCC in c-myc/TGFα transgenic male mice aged 20-34 weeks were analyzed. On gadoxetate acid-enhanced MRI, the signal intensity was 752.4 for liver parenchyma and 924.5 for HCC. The contrast to noise ratio was 20.4, the percentage enhancement was 267.1% for normal liver parenchyma and 353.9% for HCC. The fat content was 11.2% for liver parenchyma and 16.2% for HCC. There was a correlation between fat content and signal intensity with r = 0.7791. All parameters were statistically significant with P < 0.05. Our data indicate that gadoxetate acid contrast enhancement allows sensitive detection of HCC in c-myc/TGFα transgenic mice and determination of the fat content seems to be an additional useful parameter for HCC.

Different signal intensity at Gd-EOB-DTPA compared with Gd-DTPA-enhanced MRI in hepatocellular carcinoma transgenic mouse model in delayed phase hepatobiliary imaging.

PURPOSE: To evaluate hyperintense Gd-DTPA- compared with hyper- and hypointense Gd-EOB-DTPA-enhanced magnet resonance imaging (MRI) in c-myc/TGFα transgenic mice for detecting hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Twenty HCC-bearing transgenic mice with overexpression of the protooncogene c-myc and transforming growth factor-alpha (TGF-α) were analyzed. MRI was performed using a 3-T MRI scanner and an MRI coil. The imaging protocol included Gd-DTPA- and Gd-EOB-DTPA-enhanced T1-weighted images. The statistically evaluated parameters are signal intensity (SI), signal intensity ratio (SIR), contrast-to-noise ratio (CNR), percentage enhancement (PE), and signal-to-noise ratio (SNR). RESULTS: On Gd-DTPA-enhanced MRI compared with Gd-EOB-DTPA-enhanced MRI, the SI of liver was 265.02 to 573.02 and of HCC 350.84 to either hyperintense with 757.1 or hypointense with 372.55 enhancement. Evaluated parameters were SNR of HCC 50.1 to 56.5/111.5 and SNR of liver parenchyma 37.8 to 85.8, SIR 1.32 to 1.31/0.64, CNR 12.2 to 26.1/-30.08 and PE 42.08% to 80.5/-98.2%, (P < 0.05). CONCLUSION: Gd-EOB-DTPA is superior to Gd-DTPA for detecting HCC in contrast agent-enhanced MRI in the c-myc/TGFα transgenic mouse model and there was no difference between the hyperintense or hypointense appearance of HCC. Either way, HCCs can easily be distinguished from liver parenchyma in mice.

Pretreatment serum microRNA-122 is not predictive for treatment response in chronic hepatitis C virus infection.

BACKGROUND: MicroRNA-122 is a liver specific microRNA and is elevated in the sera of patients with chronic hepatitis C virus infection. Hepatic microRNA-122 levels have been described to be reduced in patients with non-response to antiviral treatment with pegylated interferon-α and ribavirin. AIM: Assessment of differences in serum microRNA-122 levels in patients with sustained virological response and non-response. METHODS: RNA was extracted from pretreatment serum samples and microRNA-122 and microRNA-16 levels were measured by quantitative PCR and compared in patients with sustained virological response and non-response. RESULTS: The levels of microRNA-122 and microRNA-16 in the sera did not differ between patients with sustained virological response and non-response. CONCLUSION: Serum microRNA-122 is not a suitable marker for treatment response prediction to combination therapy with pegylated interferon-α and ribavirin in patients with chronic hepatitis C virus infection.

Serum microRNA-21 as marker for necroinflammation in hepatitis C patients with and without hepatocellular carcinoma.

BACKGROUND: MicroRNA-21 (miR-21) is up-regulated in tumor tissue of patients with malignant diseases, including hepatocellular carcinoma (HCC). Elevated concentrations of miR-21 have also been found in sera or plasma from patients with malignancies, rendering it an interesting candidate as serum/plasma marker for malignancies. Here we correlated serum miR-21 levels with clinical parameters in patients with different stages of chronic hepatitis C virus infection (CHC) and CHC-associated HCC. METHODOLOGY/PRINCIPAL FINDINGS: 62 CHC patients, 29 patients with CHC and HCC and 19 healthy controls were prospectively enrolled. RNA was extracted from the sera and miR-21 as well as miR-16 levels were analyzed by quantitative real-time PCR; miR-21 levels (normalized by miR-16) were correlated with standard liver parameters, histological grading and staging of CHC. The data show that serum levels of miR-21 were elevated in patients with CHC compared to healthy controls (P<0.001); there was no difference between serum miR-21 in patients with CHC and CHC-associated HCC. Serum miR-21 levels correlated with histological activity index (HAI) in the liver (r = -0.494, P = 0.00002), alanine aminotransferase (ALT) (r = -0.309, P = 0.007), aspartate aminotransferase (r = -0.495, P = 0.000007), bilirubin (r = -0.362, P = 0.002), international normalized ratio (r = -0.338, P = 0.034) and γ-glutamyltransferase (r = -0.244, P = 0.034). Multivariate analysis revealed that ALT and miR-21 serum levels were independently associated with HAI. At a cut-off dC(T) of 1.96, miR-21 discriminated between minimal and mild-severe necroinflammation (AUC = 0.758) with a sensitivity of 53.3% and a specificity of 95.2%. CONCLUSIONS/SIGNIFICANCE: The serum miR-21 level is a marker for necroinflammatory activity, but does not differ between patients with HCV and HCV-induced HCC.

Serum miR-122 as a biomarker of necroinflammation in patients with chronic hepatitis C virus infection.

OBJECTIVES: The liver contains large amounts of microRNA-122 (miR-122), whereas other tissues contain only marginal amounts of this miRNA. MicroRNAs have also been found to circulate in the blood in a cell-free form; their potential as readily accessible disease markers is currently evaluated. Here, we investigated if the serum levels of miR-122 might be useful as disease parameter in patients with chronic hepatitis C virus (HCV) infection. METHODS: RNA was extracted from sera of patients with chronic HCV infection (CHC) and healthy controls and was analyzed for miR-22 content by quantitative real-time reverse-transcription polymerase chain reaction. miR-122 serum levels were correlated with standard parameters of liver function. Liver biopsies from the same patients were examined for the histologic activity index (HAI) and the degree of fibrosis. RESULTS: Sera from patients with CHC contained higher levels of miR-122 than sera from healthy controls. Serum miR-122 levels correlated well with markers of liver inflammatory activity, that is, the serum levels of alanine leucine transaminase (ALT) and aspartate transaminase, and the HAI score. In patients with persistently normal ALT levels, serum miR-122 levels did not differ from healthy controls. There was no correlation of serum miR-122 levels with serum albumin, international normalized ratio, liver fibrosis, or serum HCV RNA. CONCLUSIONS: The serum level of miR-122 strongly correlates with serum ALT activity and with necroinflammatory activity in patients with CHC and elevated ALT levels, but not with fibrosis stage and functional capacity of the liver.