The observed anti-apoptotic phenotype in HB cell lines may contribute to resistance to cytotoxic drugs used in the standard treatment protocol of HB. These pre-clinical results suggest that apoptosis sensitizers with BH-3 mimicry, such as ABT-737, should be further evaluated in preclinical models of HB.

Treatment with sorafenib led to a potent inhibition of cell viability, tumour progression and angiogenesis. Sorafenib might therefore also be a promising treatment option for high risk or recurrent HB.

In children with hepatocellular carcinoma (pHCC) the 5-year overall survival rate is poor. Effects of cytostatic therapies such as cisplatin and doxorubicin are limited due to chemoresistance and tumor relapse. In adult HCC, several antitumor properties are described for the use of curcumin. Curcumin is one of the best-investigated phytochemicals in complementary oncology without relevant side effects. Its use is limited by low bioavailability. Little is known about the influence of curcumin on pediatric epithelial hepatic malignancies. We investigated the effects of curcumin in combination with cisplatin on two pediatric epithelial liver tumor cell lines. As mechanisms of action inhibition of NFkappaB, beta-catenin, and decrease of cyclin D were identified. Using a mouse xenograft model we could show a significant decrease of alpha-fetoprotein after combination therapy of oral micellar curcumin and cisplatin. Significant concentrations of curcuminoids were found in blood samples, organ lysates, and tumor tissue after oral micellar curcumin administration. Micellar curcumin in combination with cisplatin can be a promising strategy for treatment of pediatric HCC.

The data provide evidence that ABT-737 and obatoclax might improve treatment results in children with HB.

BackgroundThe primary goal of current chemotherapy in hepatoblastoma (HB) is reduction of tumour volume and vitality to enable complete surgical resection and reduce risk of recurrence or metastatic disease. Drug resistance remains a major challenge for HB treatment. In some malignancies inhibition of anti-apoptotic pathways using small BH3 mimetic molecules like ABT-737 shows synergistic effects in combination with cystotoxic agents in vitro. Now we analysed toxicology and synergistic effects of this approach in HB cells and HB xenografts.MethodsViability was monitored in HB cells (HUH6 and HepT1) and fibroblasts treated with paclitaxel, ABT-737 and a combination of both in a MTT assay. HUH6 xenotransplants in NOD/LtSz-scid IL2Rγnull mice (NSG) were treated accordingly. Tumour volume and body weight were monitored. Xenografted tumours were analysed by histology and immunohistochemistry (Ki-67 and TUNEL assay).ResultsABT-737 reduced viability in HUH6 and HepT1 cells cultures at concentrations above 1 μM and also enhanced the cytotoxic effect of paclitaxel when used in combination. Thereby paclitaxel could be reduced tenfold to achieve similar reduction of viability of tumour cells. In contrast no toxicity in fibroblasts was observed at the same regiments. Subcutaneous HB (HUH6) treated with paclitaxel (12 mg/kg body weight, n = 7) led to delayed tumour growth in the beginning of the experiment. However, tumour volume was similar to controls (n = 5) at day 25. Combination treatment with paclitaxel and ABT-737 (100 mg/kg, n = 8) revealed significantly 10 fold lower relative tumour volumes compared to control and paclitaxel groups. Paclitaxel dependent toxicity was observed in this mice strain.ConclusionsOur results demonstrate enhancement of chemotherapy by using modulators of apoptosis. Further analyses should include improved pharmacological formulations of paclitaxel and BH3 mimetics in order to reduce toxicological effects. Sensitising HB to apoptosis may also render resistant HB susceptible to established chemotherapy regimens.