Abstract: Inhibition of deacetylases represents a new treatment option for human cancer diseases. We applied the novel and potent pan-deacetylase inhibitor panobinostat (LBH589) to human hepatocellular carcinoma models and investigated by which pathways tumor cell survival is influenced. HepG2 (p53wt) and Hep3B (p53null) responded to panobinostat treatment with a reduction of cell proliferation and a significant increase in apoptotic cell death at low micromolar concentrations. Apoptosis was neither mediated by the extrinsic nor the intrinsic pathway but quantitative RT-PCR showed an upregulation of CHOP, a marker of the unfolded protein response and endoplasmic reticulum stress with subsequent activation of caspase 12. Dependent on the p53 status, a transcriptional upregulation of p21(cip1/waf1), an increased phosphorylation of H2AX, and an activation of the MAPK pathway were observed. In a subcutaneous xenograft model, daily i.p. injections of 10 mg/kg panobinostat lead to a significant growth delay with prolonged overall survival, mediated by reduced tumor cell proliferation, increased apoptosis and reduced angiogenesis in tumor xenografts. Panobinostat increased the acetylation of histones H3 and H4. Panobinostat is a well tolerated new treatment option for HCC that activates alternative pathways of apoptosis, also in p53-deficient tumors.
Abstract: Abstract Intermittent energy application seems to have positive effects in achieving necrotic zones. We analyzed different pulse periods (PPs) to optimize this method. A radiofrequency alternating current was delivered via a triple-needle applicator (3 cm distance of each needle) introduced into freshly procured bovine liver. The open applicator system was constantly perfused with physiological NaCl solution (3x80 ml/h, power output was constant 90 W). Radiofrequency current was fed to the individual needle in turn of varying PPs (1, 2, 5, and 7 s) over 15 min. Each experimental run comprised a total of 30 applications and temperature was recorded over time. The largest necrotic diameters were found at PP 1 s (relevant: shortest axial diameter/D in the center of the lesion: 9.27 cm, SD+/-0.97 cm) (PP 2 s D=8.65 cm, SD+/-0.95 cm, p=0.021; PP 5 s D=8.35 cm, SD+/-0.95 cm, p=0.001; PP 7 s D=8.18 cm, SD+/-0.79 cm, p=0.0001). Neither doubling the perfusion rate nor raising the concentration of the perfusion liquid led at PP 1 s to increased necrotic diameters (p=0.82). Our study shows that reducing the PP to 1 s of an open perfused intermittent radiofrequency ablation system produces significantly larger coagulation volumes in explanted liver tissue reaching necrotic diameters over 9 cm. Neither doubling perfusion rates nor higher concentrated perfusion liquid increase necrotic diameters.
Abstract: The overall survival for patients with advanced hepatocellular carcinoma (HCC) is still limited. Although the multi-kinase inhibitor sorafenib has recently been approved for this disease, response rates are still low and patients often face dose-limiting toxicities which lead to a reduction in prognosis and treatment success. We here report a patient with metastasized HCC who shows a sustained response for more than 30 mo to sorafenib therapy after failure of a first line therapy with gemcitabine, oxaliplatin and bevacizumab.
Abstract: Tumor cells have the capability to trans- and to dedifferentiate, for example by reactivating embryonic development genes and stem cell characteristics. The aim of our study was to show the differential expression of stem- and progenitor cell markers in human hepatocellular carcinoma cell lines (HCC). Different human HCC cell lines (HUH7, HUH7 5-15, HUH7 pcDNA3.1, Hep3B and HepG2) were cultured under standard conditions in vitro or implanted subcutaneously (5x10(6) cells) in male NMRI mice. Specimens were characterized by quantitative real-time PCR, Western blotting, methylation-specific PCR and immunohistochemistry for markers of differentiation (cytokeratins, vimentin), embryonic development or stem cells (PTC, PDX-1, SHH, Thy1, c-kit, CD34, beta-catenin, Ki-67). The investigated HCC cell lines showed different patterns of marker expression allowing to distinguish four distinct groups: the classical cholangiocellular type (Huh-7, Huh-7 pcDNA3.1, Hep3B) with expression of CK7/19, beta-catenin and CD34; a dedifferentiated mesenchymal-proliferative type (Huh-7 5-15) characterized by CK19, Vimentin and Ki-67; a dedifferentiated embryonic-development type (Hep3B implanted in matrigel) with expression of CK19, beta-catenin and PTC and a classical HCC type (HepG2) showing CK18/19 and beta-catenin expression. HCC cell lines showed significantly different expression patterns of differentiation markers in a xenograft model. Furthermore, direct association of some markers was observed. The groups differ from each other in expression patterns, but also show that environmental factors play an important role in the behaviour of cells.
Abstract: PURPOSE: To asses if laser-induced thermotherapy (LITT) induces a specific cytotoxic T cell response in patients treated with LITT for colorectal cancer liver metastases. METHODS: Eleven patients with liver metastases of colorectal cancer underwent LITT. Blood was sampled before and after LITT. Peripheral T cell activation was assessed by an interferon gamma (IFNg) secretion assay and flow cytometry. Test antigens were autologous liver and tumor lysate obtained from each patient by biopsy. T cells were stained for CD3/CD4/CD8 and IFNg to detect activated T cells. The ratio of IFNg positive to IFNg negative T cells was determined as the stimulation index (SI). To assess cytolytic activity, T cells were co-incubated with human colorectal cancer cells (CaCo) and cytosolic adenylate kinase release was measured by a luciferase assay. RESULTS: IFNg secretion assay: before LITT SI was 12.73 (+/-4.83) for CD3+, 4.36 (+/-3.32) for CD4+ and 3.64 (+/-1.77) for CD8+ T cells against autologous tumor tissue. Four weeks after LITT SI had increased to 92.09 (+/-12.04) for CD3+ (P < 0.001), 42.92 (+/-16.68) for CD4+ (P < 0.001) and 47.54 (+/-15.68) for CD8+ T cells (P < 0.001) against autologous tumor tissue. No increased SI was observed with normal liver tissue at any time point. Cytotoxicity assay: before LITT activity against the respective cancer cells was low, with RLU = 1,493 (+/-1,954.68), whereas after LITT cytolytic activity had increased to RLU = 7,260 [+/-3,929.76 (P < 0.001)]. CONCLUSION: Patients with liver metastases of colorectal cancer show a tumor-specific cytotoxic T cell stimulation and a significantly increased cytolytic activity of CD3+, CD4+ and CD8+ T cells after LITT against an allogenic tumor (CaCo cell line).
Abstract: Effective therapies for advanced stages of hepatocellular carcinoma (HCC) have yet to be developed. We investigated how far a combination of the HDAC inhibitor MS-275 and the CDK inhibitor CYC-202 synergizes to inhibit proliferation and promotes apoptosis of hepatoma cells in vitro. Human hepatoma cell lines Hep3B and HepG2 as well as primary human foreskin fibroblasts as non-malignant controls were cultured under standardized conditions and incubated with increasing concentrations of CYC-202 and MS-275 as single agents and in combination. After 24 to 72 h, apoptosis was analyzed by flow cytometry (propidium iodide, JC-1) and by immunocytochemistry for cytokeratin 18 fragmentation. DNA synthesis was assessed using bromodeoxyuridine incorporation. Protein was separated for Western blotting against p21, bax and bcl-2 and fluorimetric activity assays against caspase 3 and 8. The results showed that the combination of CYC-202 and MS-275 leads to better pro-apoptotic effects than the employment of single substances. Apoptosis was induced via the mitochondrial pathway as evidenced by a shift in the bax/bcl-2 ratio and breakdown of mitochondrial transmembrane potentials. Caspase assays revealed a strong induction of caspase 3 but not of the extrinsic initiator caspase 8. In conclusion, combination therapy with the biomodulators MS-275 and CYC-202 is a promising treatment option for HCC.
Abstract: We investigated the effect of AEE788, a novel dual receptor tyrosine kinase inhibitor of the EGF and the VEGF receptor, for treatment of human HCC cell lines and in a subcutaneous xenograft model. Cell viability and apoptosis of HepG2 and Hep3B cells incubated with 0.1-100 microM AEE788 were quantified. In vivo, HepG2 cells were xenografted to NMRI mice and animals were treated orally with 50 mg/kg AEE788 3x/week. Immunohistochemistry and quantitative Western blotting was performed for pathway analysis in vitro and in vivo. AEE788 reduced growth and induced apoptosis of HCC cells by disrupting mitochondrial transmembrane potentials and inhibiting MAPK phosphorylation. In the xenografts, AEE788 lead to a reduced tumor growth by reducing proliferation and vascularisation. Except for a reversible skin reaction and weight loss, no signs of toxicity were observed. AEE788 is a promising new option for the treatment of HCC.
Abstract: PURPOSE: Radiofrequency ablation (RFA) with multiple saline-perfused electrodes is a minimally invasive alternative to archive large coagulation zones. Few long-term results have been published so far. This is a report of our long-term experience using multiple saline-perfused electrodes for the treatment of malignant hepatic tumors. MATERIALS AND METHODS: Thirty-eight patients with biopsy-proven hepatocellular carcinoma (HCC) or liver metastases of colorectal cancer (CRC) (17 CRC, 21 HCC) with a total of 56 tumors (26 CRC, 30 HCC) were treated with the Integra HiTT 106 RF generator using multiple saline-perfused electrodes. Mean size was 42 mm for HCC and 36 mm for CRC. Follow-up examinations took place after 2 days and 1, 3, 6, and 9 months after RFA and every 6 months thereafter. RESULTS: We performed 2.6 (2.7 CRC, 2.4 HCC) sessions per patient. Major complications occurred in 2% of patients. Ninety-two percent (35/38) were treated technically successfully. Local tumor progression was found in 8 patients out of 35 (22% overall, 21% HCC, 25% CRC). For HCC, 43% of patients suffered distant intrahepatic recurrence. One- and two-year survival for HCC patients was 71% and 58%. (Child-Pugh status A, one- and two-year survival was 90% and 80%; Child status B, 35% and 18%). For CRC, 11 of 17 (65%) patients suffered distant intrahepatic recurrence. One- and two-year survival for CRC patients was 94% and 86%. CONCLUSIONS: RFA using multiple saline-perfused electrodes shows results in the treatment of liver tumors comparable with other established ablation techniques.
Abstract: PURPOSE: For many reasons, resection of hepatocellular cancer (HCC) is not feasible in most cases. Radiofrequency (RFA) ablation has proven to be an effective minimally invasive alternative. It has been shown in ex vivo and animal trials that needle applicators perfused with isotonic saline solution could be an effective approach to enlarging the coagulation zone. However, long term survival data for the treatment of HCC are not yet available. MATERIALS AND METHODS: 37 patients with a total of 64 histologically proven HCC with a maximum of 3 tumors of up to 6 cm and a contraindication to partial liver resection or orthotopic liver transplantation were treated with the Integra HiTT106 using wet monopolar single, wet bipolar double or wet triple needle electrodes. The mean HCC size was 37.7 mm (range 15 to 60 mm). Follow-up examinations were performed 2 days and 1, 3, 6, 9 months after RFA and every 6 months thereafter. The survival rate was calculated from the time of the first RFA session. RESULTS: 1, 2 and 5-year survival was 24/32 (75%), 14/31 (45%) and 3/21 (14%) overall; 18/19 (95%), 12/18 (67%) and 3/10 (30%) for HCC Child A; and 6/13 (46%), 2/13 (15%) and 0/11 (0%), for HCC Child B. Complete remission was achieved in 86.5 % of the patients (total: 32 out of 37, multi-needle 18 / 21, single needle 14 / 16). Distant recurrence occurred overall in 20 out of 37 patients (54%), including 9 of 21 treated with multiple needles (43% of patients) and 11 of the 16 patients treated with a single electrode (69%). The overall complication rate was 10.8%. Local recurrence was found for tumors measuring 3 cm-5 cm (n=28) in 7 out of 13 cases after single electrode RFA and in 1 out of 15 after multiple electrode treatment (significant, p=0.009). No significant difference between the single and multi-needle group was found for tumors >5 cm and <3 cm. CONCLUSION: RFA using multiple wet electrodes shows promise as an effective method for treating inoperable HCC especially in cases with well-preserved liver function. Multiple electrodes seem to be superior to single electrodes with respect to the local recurrence rate for tumors between 3 and 5 cm.
Abstract: AIM: To assess if a specific cytotoxic T cell response can be induced in patients with malignant liver tumors treated with radio-frequency ablation (RFA). METHODS: Six Patients with liver metastases of colorectal cancer and 6 with hepatocellular carcinoma (HCC) underwent RFA. Blood was sampled before, 4 and 8 wk after RFA. Test antigens were autologous liver and tumor lysate obtained from each patient by biopsy. Peripheral T cell activation was assessed by an interferon gamma (IFNgamma) secretion assay and flow cytometry. T cells were double-stained for CD4/CD8 and IFNgamma to detect cytotoxic T cells. The ratio of IFNgamma positive and IFNgamma negative T cells was determined as the stimulation index (SI). To assess cytolytic activity, T cells were co-incubated with human CaCo colorectal cancer and HepG2 HCC cells and release of cytosolic adenylate kinase was measured by a luciferase assay. RESULTS: Before RFA SI was 0.021 (+/- 0.006) for CD4(+) and 0.022 (+/- 0.004) for CD8(+) T cells against nonmalignant liver tissue and 0.018 (+/- 0.005) for CD4(+) and 0.021 (+/- 0.004) for CD8(+) cells against autologous tumor tissue. Four weeks after RFA SI against tumor tissue increased to 0.109 (+/- 0.005) for CD4(+) and 0.11 (+/- 0.012) for CD8(+) T cells against HCC, and to 0.115 (+/- 0.031) for CD4(+) and 0.15 (+/- 0.02) for CD8(+) cells for colorectal metastases (P < 0.0001). No increased SI was observed with nonmalignant tumor tissue at all time points. Before RFA cytolytic activity against the respective cancer cells was low with 2.62 (+/- 0.37) relative luminescence units (RLU), but rose more than 100 fold 4 and 8 wk after RFA. Spontaneous release was < 2% of maximum release in all experiments. CONCLUSION: Patients with primary and secondary tumors of the liver show a significant tumor-specific cytotoxic T-cell stimulation with a dramatically increased tumor specific cytolytic activity of CD8(+) T cells after RFA.
Abstract: Radio-frequency ablation (RFA) is used as a minimally invasive treatment for inoperable hepatic tumors. Immunological reactions secondary to RFA may play a role in the observed tumor control. In our study, the VX2 carcinoma was implanted into the liver of rabbits. After 3 weeks, tumors were treated with RFA or were left untreated. Peripheral blood lymphocytes were harvested before tumor implantation, 2 weeks postoperatively and at 2-week intervals thereafter. T cells were stimulated with lysates of either tumor tissue or nontumorous liver loaded on autologous antigen-presenting cells and their stimulation index was determined by [(3)H]thymidine incorporation. A 3-fold increase over background or controls was considered significant. Stimulation with phytohemagglutinin served as a positive control. The animals were necropsied, and liver and tumor tissue were analyzed immunohistologically for T-cell infiltration. T cells from tumor-bearing (n = 9) and RFA-treated (n = 11) animals were investigated in a follow-up study. The mean postoperative observation was 45 days. All of the 11 RFA-treated animals exhibited circulating T cells activated specifically toward tumor antigens throughout the observation period, which was accompanied by dense T-cell infiltration. In contrast, T cells of untreated tumor-bearing rabbits showed no reaction and only sparse T cell infiltration. We concluded that RFA induces a tumor-specific T-cell reaction in the otherwise unreactive tumor-bearing host, apparently overcoming immune tolerance and leading to the presentation of otherwise cryptic tumor antigens. Therefore, in addition to destroying tumor tissue, RFA induces an immune response against tumor antigens that may be exploited in multimodal antitumor strategies.
