Influence of Rictor and Raptor Expression of mTOR Signaling on Long-Term Outcomes of Patients with Hepatocellular Carcinoma.

BACKGROUND: Aberrant signaling mediated by the mammalian target of rapamycin (mTOR) occurs at high frequency in hepatocellular carcinoma (HCC), indicating that mTOR is a candidate for targeted therapy. mTOR forms two complexes called mTORC1 (mTOR complexed with raptor) and mTORC2 (mTOR complexed with rictor). There are minor studies of the expression kinetics of mTORC1 and mTORC2 in HCC. METHODS: We studied 62 patients with HCC who underwent curative resection. We used univariate and multivariate analyses to identify factors that potentially influence disease and overall survival after hepatectomy. The mRNA and protein levels of mTOR, rictor and raptor in cancer and non-cancer tissues were analyzed using quantitative RT-PCR, immunohistochemistry and Western blotting. RESULTS/CONCLUSION: High ratio of the levels of rictor and raptor mRNAs in tumors was identified as independent prognostic indicators for disease-free survival. Low and high levels of preoperative serum albumin and mTOR mRNA in the tumor, respectively, were identified as independent indicators of overall survival. HCC is likely to recur early after hepatic resection in patients with high levels of mTOR and rictor mRNAs and high rictor/raptor ratios in cancer tissues. We conclude that analysis of mTOR expression in cancer tissues represents an essential strategy to predict HCC recurrence after curative treatment.

[Clinical applications of indocyanine green-fluorescent imaging to liver surgery].

BACKGROUND: Intravenous injection of the indocyanine green (ICG) reagent was performed as a liver function test 1 to 2 weeks prior to surgery. ICG fluorescent imaging was performed using the Photodynamic Eye (PDE) infrared camera (Hamamatsu Photonics k. k., Shizuoka, Japan). METHODS: Intravenous injection of the ICG reagent was performed as a liver function test 1 to 2 weeks before surgery. ICG fluorescent imaging was performed using the PDE infrared camera. RESULTS: ICG fluorescent imaging was useful for liver surgical navigation as follows: three cases of recurrent hepatocellular carcinoma(HCC) after transcatheter arterial chemoembolization or thermal ablation therapy; three cases of colorectal metastatic liver tumors after chemotherapy as conversion therapy; two cases of intrahepatic cholangiocellular carcinoma (ICC); and two cases of surface HCC that were not detected by preoperative computed tomography (CT) scan. In the ICC cases, although dilatation of the bile duct could be detected, the tumor margins were ambiguous by ultrasonography(US). ICG fluorescent imaging clearly described the dilatation of the bile duct including the tumor. CONCLUSIONS: ICG fluorescent imaging was useful for liver surgical navigation including selection of the mode of hepatic resection.