An Overview of the Enhanced Effects of Curcumin and Chemotherapeutic Agents in Combined Cancer Treatments.

Due to the progressive ageing of the human population, the number of cancer cases is increasing. For this reason, there is an urgent need for new treatments that can prolong the lives of cancer patients or ensure them a good quality of life. Although significant progress has been made in the treatment of cancer in recent years and the survival rate of patients is increasing, limitations in the use of conventional therapies include the frequent occurrence of side effects and the development of resistance to chemotherapeutic agents. These limitations are prompting researchers to investigate whether combining natural agents with conventional drugs could have a positive therapeutic effect in cancer treatment. Several natural bioactive compounds, especially polyphenols, have been shown to be effective against cancer progression and do not exert toxic effects on healthy tissues. Many studies have investigated the possibility of combining polyphenols with conventional drugs as a novel anticancer strategy. Indeed, this combination often has synergistic benefits that increase drug efficacy and reduce adverse side effects. In this review, we provide an overview of the studies describing the synergistic effects of curcumin, a polyphenol that has been shown to have extensive cytotoxic functions against cancer cells, including combined treatment. In particular, we have described the results of recent preclinical and clinical studies exploring the pleiotropic effects of curcumin in combination with standard drugs and the potential to consider it as a promising new tool for cancer therapy.

Aglianico Grape Seed Semi-Polar Extract Exerts Anticancer Effects by Modulating MDM2 Expression and Metabolic Pathways.

Grapevine (Vitis vinifera L.) seeds are rich in polyphenols including proanthocyanidins, molecules with a variety of biological effects including anticancer action. We have previously reported that the grape seed semi-polar extract of Aglianico cultivar (AGS) was able to induce apoptosis and decrease cancer properties in different mesothelioma cell lines. Concomitantly, this extract resulted in enriched oligomeric proanthocyanidins which might be involved in determining the anticancer activity. Through transcriptomic and metabolomic analyses, we investigated in detail the anticancer pathway induced by AGS. Transcriptomics analysis and functional annotation allowed the identification of the relevant causative genes involved in the apoptotic induction following AGS treatment. Subsequent biological validation strengthened the hypothesis that MDM2 could be the molecular target of AGS and that it could act in both a p53-dependent and independent manner. Finally, AGS significantly inhibited tumor progression in a xenograft mouse model of mesothelioma, confirming also in vivo that MDM2 could act as molecular player responsible for the AGS antitumor effect. Our findings indicated that AGS, exerting a pro-apoptotic effect by hindering MDM2 pathway, could represent a novel source of anticancer molecules.

Ran signaling in melanoma: implications for the development of alternative therapeutic strategies.

We performed a comparative study between two human metastatic melanoma cell lines (A375 and 526), and melanocytes (FOM78) by gene expression profiling and pathway analysis, using Gene Set Enrichment Analysis (GSEA) and Ingenuity Pathway Analysis (IPA) software. Genes involved in Ran signaling were significantly over-represented (p ≤ 0.001) and up-regulated in melanoma cells. A melanoma-associated molecular pathway was identified, where Ran, Aurora Kinase A (AurkA) and TERT were up-regulated, while c-myc and PTEN were down-regulated. A consistent high Ran and AurkA gene expression was detected in about 48% and 53%, respectively, of 113 tissue samples from metastatic melanoma patients. AurkA down-regulation was observed in melanoma cells, by Ran knockdown, suggesting AurkA protein is a Ran downstream target. Furthermore, AurkA inhibition, by exposure of melanoma cells to MLN8054, a specific AurKA inhibitor, induced apoptosis in both melanoma cell lines and molecular alterations in the IPA-identified molecular pathway. These alterations differed between cell lines, with an up-regulation of c-myc protein level observed in 526 cells and a slight reduction seen in A375 cells. Moreover, Ran silencing did not affect the A375 invasive capability, while it was enhanced in 526 cells, suggesting that Ran knockdown, by AurkA down-regulation, resulted in a Ran-independent enhanced melanoma cell invasion. Finally, AurK A inhibition induced a PTEN up-regulation and its action was independent of B-RAF mutational status. These findings provide insights relevant for the development of novel therapeutic strategies as well as for a better understanding of mechanisms underlying therapy resistance in melanoma.