Polydatin Induces Differentiation and Radiation Sensitivity in Human Osteosarcoma Cells and Parallel Secretion through Lipid Metabolite Secretion.

Osteosarcoma is a bone cancer characterized by the production of osteoid tissue and immature bone from mesenchymal cells. Osteosarcoma mainly affects long bones (femur is most frequently site) and occur in children and young adults with greater incidence. Here, we investigated the role accomplished by polydatin, a natural antioxidative compound, in promoting osteogenic differentiation alone or after radiation therapy on osteosarcoma cells. In vitro, polydatin significantly induced cell cycle arrest in S-phase and enhanced bone alkaline phosphatase activity. Moreover, the differentiation process was paralleled by the activation of Wnt-ß-catenin pathway. In combination with radiotherapy, the pretreatment with polydatin promoted a radiosensitizing effect on osteosarcoma cancer cells as demonstrated by the upregulation of osteogenic markers and reduced clonogenic survival of tumor cells. Additionally, we analyzed, by mass spectrometry, the secretion of sphingolipid, ceramides, and their metabolites in osteosarcoma cells treated with polydatin. Overall, our results demonstrate that polydatin, through the secretion of sphingolipids and ceramide, induced osteogenic differentiation, alone and in the presence of ionizing therapy. Future investigations are needed to validate the use of polydatin in clinical practice as a potentiating agent of radiotherapy-induced anticancer effects.

Vascular endothelial growth factor: An important molecular target of curcumin.

The discovery of Vascular Endothelial Growth Factor (VEGF), the key modulator of angiogenesis, has triggered intensive research on anti-angiogenic therapeutic modalities. Although several clinical studies have validated anti-VEGF therapeutics, with few of them approved by the U.S. Food and Drug Administration (FDA), anti-angiogenic therapy is still in its infancy. Phytochemicals are compounds that have several metabolic and health benefits. Curcumin, the yellow pigment derived from turmeric (Curcuma longa L.) rhizomes, has a wide range of pharmaceutical properties. It has also been shown to inhibit VEGF by several studies. In this review, we elaborate the effect of curcumin on VEGF and angiogenesis and its therapeutic application.

Anti-Cancer and Radio-Sensitizing Effects of Curcumin in Nasopharyngeal Carcinoma.

Nasopharyngeal Cancer (NPC) is a rare type of head and neck cancer that is mainly treated by radiotherapy, but sometimes it is radioresistant. Curcumin is a polyphenolic natural product with established anticancer effects in various human cancers. Recent studies have shown that curcumin has therapeutic and radiosensitizing effects on NPC cells. In fact, it has been found that curcumin can sensitize NPC cells to radiation through different mechanisms, including modulation of ROS generation, Jab1/CSN5 and non-coding RNAs. As curcumin is safe and lacks systemic toxic effects in humans, it may be considered as a potential candidate to enhance the therapeutic effects of radiation and potentiate the efficacy of chemotherapy in the context of combination regimens.

A Long-term Treatment with Silybin in Patients with Non-alcoholic Steatohepatitis Stimulates Catalase Activity in Human Endothelial Cells.

AIM: To compare levels of oxidative stress markers in patients' sera with non-alcoholic steatohepatitis (NASH) treated for 12 months (T12) with silybin conjugated with phosphatidylcholine (Realsil®) (R) or placebo (P) and investigate oxidative stress responses in human endothelial cells conditioned with patients' sera. PATIENTS AND METHODS: We recruited twenty-seven patients with histological NASH. We measured thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD) and catalase (CAT) activities in human endothelial cells conditioned with patients' sera exposed or not to H2O2 Results: We found in decreased-TBARS patients' sera, at T12, a decrease of alanine aminotransferase (p=0.038), transforming growth factor-beta (p=0.009) and procollagen I (p=0.001). By dividing patients into two groups, increased (P-I/R-I) and decreased TBARS (P-II/R-II) at T12 compared to T0, we found an increased CAT activity in conditioned endothelial cells at T12 in both groups (p=0.05 and p=0.001, respectively). CONCLUSION: Realsil® may be effective against endothelial dysfunction by stimulating the cellular antioxidant defense.

Naturally occurring anti-cancer agents targeting EZH2.

Natural products are considered as promising tools for the prevention and treatment of cancer. The enhancer of zeste homolog 2 (EZH2) is a histone methyltransferase unit of polycomb repressor complexes such as PRC2 complex that has oncogenic roles through interference with growth and metastatic potential. Several agents targeting EZH2 has been discovered but they often induce side effects in clinical trials. Recently, EZH2 has emerged as a potential target of natural products with documented anti-cancer effects and this discloses a new scenario for the development of EZH2 inhibitory strategies with agents with low cytotoxic detrimental effects. In fact, several natural products such as curcumin, triptolide, ursolic acid, sulforaphane, davidiin, tanshindiols, gambogic acid, berberine and Alcea rosea have been shown to serve as EZH2 modulators. Mechanisms like inhibition of histone H3K4, H3K27 and H3K36 trimethylation, down-regulation of matrix metalloproteinase expression, competitive binding to the S-adenosylmethionine binding site of EZH2 and modulation of tumor-suppressive microRNAs have been demonstrated to mediate the EZH2-inhibitory activity of the mentioned natural products. This review summarizes the pathways that are regulated by various natural products resulting in the suppression of EZH2, and provides a plausible molecular mechanism for the putative anti-cancer effects of these compounds.

Polydatin administration improves serum biochemical parameters and oxidative stress markers during chronic alcoholism: a pilot study.

AIM: Polydatin, a hydroxystilbene derived from the rhizome of Polygonum cuspidatum, elicits hepatoprotective and neuroprotective effects through its anti-oxidant properties. The present study aimed to determine the effects of oral administration of polydatin in alcoholic patients in order to improve liver biochemical parameters, serum oxidative stress and mental state. We enrolled 20 chronic alcoholic patients hospitalized for rehabilitative therapy. The patients were divided into two groups receiving the following treatment regimes for two weeks: administration of an anti-oxidant nutritional supplement containing glutathione and vitamin C (group 1), or glutathione, vitamin C and polydatin (group 2). RESULTS: The results of the present study show that elevated plasma aspartate aminotransferase and alanine aminotransferase levels in patients after two weeks of alcohol withdrawal were significantly reduced by polydatin (group 2), when compared to group 1. Polydatin also significantly reduced lipid peroxidation levels. Finally, our preliminary data resulting from the analysis of the Mini-Mental Status suggest that polydatin improves cognitive performance. CONCLUSION: Daily dietary administration of polydatin should be considered for prevention and treatment of liver disease and cognitive impairment in alcoholic patients.

Exploring the efficacy and safety of single-agent sorafenib in a cohort of Italian patients with hepatocellular carcinoma.

This study investigates the effectiveness and safety of sorafenib in a heterogeneous cohort of Child-Pugh A, B and C patients with advanced hepatocellular carcinoma in a clinical-practice scenario. Adult patients with hepatocellular carcinoma and treated with sorafenib 800 mg/day were eligible for this multicentric retrospective observational study. Safety analyses were performed and the effectiveness of sorafenib was assessed in terms of time to progression (TTP) and overall survival (OS). In total, 93 patients were enrolled: 14 were Child-Pugh A, 70 were Child-Pugh B and nine were Child-Pugh C. No differences in the frequency of grade 3 adverse events among different Child-Pugh classes were reported. In the overall cohort, median OS was 12 months (95% CI: 11.7-12.8 months) and TTP was 3 months (95% CI: 2.5-3.4 months). The Child-Pugh score had a statistically significant effect on TTP: 6.6 months in Child-Pugh A, 2.8 months in Child-Pugh B and 2.0 months in Child-Pugh C patients (p = 0.012). To our knowledge, this study includes the largest cohort of Caucasian Child-Pugh B and C patients ever treated with sorafenib. Although the retrospective design of this study does not allow reaching any definite conclusion, the results could lend some preliminary support to the safety and the effectiveness of sorafenib monotherapy in patients with Child-Pugh B and Child-Pugh C liver function.

Molecular targets for the treatment of multiple myeloma.

Multiple myeloma (MM) represents a suitable disease to be treated with Molecularly targeted drugs (MTDs). MM clone aberrations affect signal transduction pathways controlling both proliferation and/or cell survival. Research findings on small drugs or monoclonal antibodies (mAb) against the components of these pathways are now available and related clinical trials in MM patients are rapidly growing up. Promising results have been recently obtained with AKT inhibitors (perifosine) and mTOR inhibitors (everolimus and temsirolimus). However, the activity of these agents used alone is still limited and can be strongly increased by their combination with other drugs such as bortezomib or dexamethasone. The present review will summarize the main signaling components that can be targeted by MTDs and the most important available results derived from the clinical trials based on their use. Another important issue in the treatment of MM is the control of the related bone disease. Two main strategies can be used: i) inhibition of bone resorption and ii) promotion of bone formation. Emerging clinical data suggest that specific MTDs are able to prolong survival not only for the prevention of the skeletal-related events but also for a direct or indirect effect on the proliferation and/or survival of MM cells. A summary on the main preclinical and clinical results in this setting will be provided. In conclusion, the use of MTD in the treatment of MM is a promising approach but still far from becoming a current indication: a new dawn is arising with still unpredictable results.

Sorafenib plus octreotide is an effective and safe treatment in advanced hepatocellular carcinoma: multicenter phase II So.LAR. study.

PURPOSE: Advanced hepatocellular carcinoma (HCC) not eligible for local therapies has limited chances of cure. Sorafenib is a multikinase inhibitor with proven activity in advanced HCC. Octreotide is used in this setting with conflicting results. Treatment with sorafenib and long-acting octreotide was tested in advanced HCC to evaluate safety and activity. METHODS: Fifty patients with advanced HCC, Child-Pugh A or B, received sorafenib at a dosage of 800 mg/day for 28 days with a following week of rest and long-acting octreotide at a dose of 40 mg, administered every 28 days. RESULTS: All patients were assessable for safety and efficacy. Sixteen patients out of 50 (34%) were naïve from other therapies, while all the others were previously treated with local and/or systemic treatments. We achieved 5 partial responses (10%), 33 stable diseases (66%) and 12 progressions of disease (24%). Median time to progression was 7.0 months (95% CI, 3.0-10.9 months), and median overall survival was 12 months (95% CI, 6.3-17.4 months). Treatment was well tolerated. Diarrhoea (6%) and hypertension (4%) were the most frequent grade 3 toxicities. CONCLUSIONS: Our data suggest that the combination between sorafenib and long-acting octreotide is active and well tolerated in patients with advanced HCC and could represent another efficacious chance for the management of this population.

In vivo anti-myeloma activity and modulation of gene expression profile induced by valproic acid, a histone deacetylase inhibitor.

Valproic acid (VPA) is a well-tolerated anticonvulsant that exerts anti-tumour activity as a histone deacetylase inhibitor. This study investigated the in vitro and in vivo activity of VPA against multiple myeloma (MM) cells. In vitro exposure of interleukin-6-dependent or -independent MM cells to VPA inhibited cell proliferation in a time- and dose-dependent manner and induced apoptosis. In a cohort of severe combined immunodeficiency mice bearing human MM xenografts, VPA induced tumour growth inhibition and survival advantage in treated animals versus controls. Flow cytometric analysis performed on MM cells from excised tumours showed increase of G(0)-G(1) and a decreased G(2)/M- and S-phase following VPA treatment, indicating in vivo effects of VPA on cell cycle regulation. Gene expression profiling of MM cells exposed to VPA showed downregulation of genes involved in cell cycle progression, DNA replication and transcription, as well as upregulation of genes implicated in apoptosis and chemokine pathways. Pathfinder analysis of gene array data identified cell growth, cell cycle, cell death, as well as DNA replication and repair as the most important signalling networks modulated by VPA. Taken together, our data provide the preclinical rationale for VPA clinical evaluation as a single agent or in combination, to improve patient outcome in MM.

Highlights of the Annual Meeting of the Italian Association for Cell Cultures (AICC): new drug delivery strategies and technological platforms for diagnosis and therapy of tumors. Part II. 6 - 7 December 2007, Naples, Italy.

In recent decades considerable advances have been achieved in the development of new strategies based on the specific delivery of drugs into tumor tissues through the use of bio-materials and nanoparticles. The AICC meeting was divided into different sessions addressing different issues. The first section was about new delivery systems for either drugs or DNA. In detail, the pharmacokinetics and pharmaco-distribution of different carrier systems were explained. Thereafter, the possibility of drug delivery with pegylated liposomes or with nanoparticles or micelles was analyzed. The crossing of the blood-brain barrier by pegylated liposomes in order to deliver antitumor drugs to brain tumor sites was also explored.

Dendritic cell-mediated cross-presentation of antigens derived from colon carcinoma cells exposed to a highly cytotoxic multidrug regimen with gemcitabine, oxaliplatin, 5-fluorouracil, and leucovorin, elicits a powerful human antigen-specific CTL response with antitumor activity in vitro.

Gemcitabine, oxaliplatin, leucovorin, and 5-fluorouracil (GOLF) is a novel multidrug regimen inducing high levels of necrosis and apoptosis in colon carcinoma cells. This regimen is also able to promote a process of Ag remodeling including up-regulation of immunotherapy targets like carcinoembryonic Ag (CEA), thymidylate synthase (TS). We have conducted a preclinical study aimed to investigate whether these drug-induced modifications would also enhance colon cancer cell immunogenicity. Several CTL lines were thus generated by in vitro stimulating human HLA-A(*)02.01(+) PBMCs, from normal donors and colon cancer patients, with autologous dendritic cells cross-primed with cell lysates of colon cancer cells untreated, irradiated, or previously exposed to different drug treatments including the GOLF regimen. Class I HLA-restricted cytolytic activity of these CTL lines was tested against colon cancer cells and CEA and TS gene transfected target cells. These experiments revealed that CTLs sensitized with GOLF-treated cancer cells were much more effective than those sensitized with the untreated colon carcinoma cells or those exposed to the other treatments. CTL lines sensitized against the GOLF-treated colon cancer cells, also expressed a greater percentage of T-lymphocyte precursors able to recognize TS- and CEA-derived peptides. These results suggest that GOLF regimen is a powerful antitumor and immunomodulating regimen that can make the tumor cells a suitable means to induce an Ag-specific CTL response. These results suggest that a rationale combination of GOLF chemotherapy with cytokine-based immunotherapy could generate a chemotherapy-modulated Ag-specific T-lymphocyte response in cancer patients able to destroy the residual disease survived to the cytotoxic drugs.