Hepatocarcinogenesis tumor grading correlated with in vivo image-guided 1H-NMR spectroscopy in a rat model.

Hepatocellular carcinoma (HCC) is a common malignancy worldwide, the occurrence of which is unevenly distributed. Most hepatocellular carcinoma cases present late and have a poor prognosis; therefore, early diagnosis is essential to prolong survival. Differential diagnosis with magnetic resonance imaging (MRI) is difficult. We studied the feasibility of using magnetic resonance spectroscopy (MRS) at 7.0 T for the diagnosis and grading of liver tumors. An animal model of hepatocarcinogenesis was used, which allowed tumor progression from precancerous lesions to hepatocellular carcinomas. This study was focused primarily on the grading of the tumors and its correlation with the ratio between the MRS peaks arising from MRS-detected lipid hydrogens (0.9, 1.3 and 5.3 ppm) and compared to the gamma-methylene hydrogens of glutamate (Glu) and glutamine (Gln) which was used as an internal reference (2.4 ppm). The lipid methylene hydrogen (1.3 ppm) to (Glu + Gln) ratio was found to correlate with the formation of differentiated small foci and (precancerous) hepatic nodules, whereas the unsaturated olefinic lipid hydrogen (5.3 ppm) to (Glu + Gln) ratio was able to correlate with the formation of late stage tumors such as adenomas and hepatocellular carcinomas. The results of our study suggest that MRS-detected alterations in lipid metabolism can be correlated with the grading of liver tumor tissue at different stages during the carcinogenesis process.

Expression of growth arrest-specific gene 6 and its receptors in dysfunctional human renal allografts.

Growth arrest-specific gene 6 (Gas6) and its receptors Rse, Axl and Mer have recently been found to be involved in a rat model of chronic allograft nephropathy (CAN). Thus, in this study we investigated the function of Gas6 and its receptors in human renal allograft dysfunction. Expression of Gas6 and its receptors was detected by immunohistochemical staining. Gas6 and its receptors were widely expressed in glomeruli, tubules and vessels of renal allografts. Gas6 expression was detected in normal-functioning allografts and was increased in acute rejection ( P<0.05), acute tubular necrosis ( P<0.05) and CAN ( P<0.01). Gas6 receptors were not upregulated in any of the allograft groups, except for the Axl receptor, which increased only in acute tubular necrosis ( P<0.01). Gas6 expression was also found to correspond with the expression of alpha-smooth muscle actin, a general marker of CAN ( r(2)=0.21, P<0.01). These findings suggest that Gas6, acting as a growth factor, is increased in the process of kidney allograft dysfunction and in CAN.

p53, deleted in colorectal cancer gene, and thymidylate synthase as predictors of histopathologic response and survival in low, locally advanced rectal cancer treated with preoperative adjuvant therapy.

PURPOSE: Adjuvant therapy, either preoperatively or postoperatively, and modifications of surgery have been used to try to improve outcome of surgery for rectal cancer in regard to both local recurrence and survival. Assessment of prognosis in patients after resection is currently primarily based on clinicopathologic factors. These predict the subsequent behavior of the tumor only imperfectly. The aim of this study was to evaluate three potential molecular genetic markers of prognosis (p53, deleted in colorectal cancer gene, and thymidylate synthase) in Dukes Stage B and C low rectal tumors treated with adjuvant therapy and to determine whether they correlate with survival, local recurrence, or the pathologic response to adjuvant therapy (assessed by extent of tumor regression and tumor down-staging). METHODS: Sixty locally advanced low rectal tumors resected after preoperative chemoradiotherapy or radiotherapy alone were studied by immunohistochemical staining for p53, deleted in colorectal cancer gene, and thymidylate synthase. In addition, p53 gene mutations were sought by polymerase chain reaction-single-strand conformation polymorphism analysis. These results were correlated with survival, local recurrence, and pathologic response to adjuvant therapy. RESULTS: Lack of thymidylate synthase staining by immunohistochemistry was associated with tumor down-staging after preoperative chemoradiotherapy but not after radiotherapy or for these two combined groups. There was no correlation between p53, deleted in colorectal cancer gene, or thymidylate synthase immunohistochemical staining or between p53 polymerase chain reaction-single-strand conformation polymorphism and local recurrence or survival in locally advanced low rectal cancers treated with preoperative adjuvant therapies. CONCLUSION: Prediction of prognosis in patients with locally advanced low rectal cancers treated with preoperative adjuvant therapies continues to be problematic. Thymidylate synthase immunohistochemistry appears to be the most promising factor of those assessed in predicting tumor down-staging after preoperative chemoradiotherapy for locally advanced low rectal cancers.

Pathology of hepatocellular carcinoma and its precursors using proton magnetic resonance spectroscopy and a statistical classification strategy.

AIM: Apply the statistical classification strategy (SCS) to magnetic resonance spectroscopy (MRS) data from liver biopsies and test its potential to discriminate between normal liver, cirrhotic nodules and nodules of hepatocellular carcinoma with a high degree of accuracy. METHODS: Liver tissue specimens from 54 patients undergoing either partial (hemi) or total hepatectomy were analysed by one-dimensional proton MRS at 8.5 Tesla. Histologically, these specimens were confirmed as normal (n=31), cirrhotic (n=59), and hepatocellular carcinoma (HCC, n=32). Diagnostic correlation was performed between the MR spectra and histopathology. An SCS was applied consisting of pre-processing MR magnitude spectra to identify spectral regions of maximal discriminatory value, and cross-validated linear discriminant analysis. RESULTS: SCS applied to MRS data distinguished normal liver tissue from HCC with an accuracy of 100%. Normal liver tissue was distinguished from cirrhotic liver with an accuracy of 92% and cirrhotic liver was distinguished from HCC with an accuracy of 98%. CONCLUSIONS: SCS applied to proton MRS of liver biopsies provides a robust method to distinguish, with a high degree of accuracy, HCC from both cirrhotic and normal liver.

Intrahepatic cytokine profiles associated with posttransplantation hepatitis C virus-related liver injury.

Recurrent chronic hepatitis, cholestatic hepatitis, and acute rejection in conjunction with hepatitis C virus (HCV) recurrence are well-recognized clinical sequelae of reinfection of the hepatic allograft with HCV. The aim of this study is to characterize intrahepatic cytokine responses associated with reinfection of the allograft with HCV in these settings. Intrahepatic messenger RNA expression of T helper cell subtype 1 (TH1) cytokines interleukin-2 (IL-2), interferon-gamma, and tumor necrosis factor-alpha and TH2 cytokines IL-4 and IL-10 was measured by real-time polymerase chain reaction system using TaqMan probes in 53 liver specimens from six groups of patients. These were: (1) recurrent chronic hepatitis C (CH-I; n = 15), (2) cholestatic hepatitis (n = 6), (3) acute rejection associated with HCV recurrence (AR-HCV; n = 12), (4) acute rejection in non-HCV-infected allografts (AR non-HCV; n = 5), (5) patients with chronic hepatitis C who did not undergo transplantation (CH-C; n = 10), and (6) non-diseased liver tissue (n = 6). Intrahepatic viral loads were measured using an Amplicor monitor assay (Roche Diagnostic Systems, Branchburg, NJ). The CH-I and CH-C groups had similar TH1 intrahepatic cytokine profiles. Compared with the CH-I group, the cholestatic group expressed increased levels of the TH2 cytokines IL-10 (P =.024) and IL-4 (P =.0024). The AR-HCV group also expressed more TH2 cytokines IL-10 (P =.014) and IL-4 (P =.034) compared with the CH-I group. Both the AR-HCV and AR non-HCV groups showed similar intrahepatic cytokine profiles. Intrahepatic viral loads were highest in the cholestatic group compared with the AR-HCV, CH-I, and CH-C groups (P =.0007). In conclusion, a novel observation is that the cholestatic group showed upregulation of the TH2 cytokines IL-10 and IL-4, in addition to high viral loads. In this setting, the TH2 immune response may favor viral replication and graft damage.