Metastasis is the major cause of death in cancer patients and more effective therapies are required. Radiotherapy is one of the most commonly used treatments for both primary breast tumors and brain metastases, with more than 60% of patients undergoing radiotherapy as a first treatment option. The efficacy of radiotherapy against metastatic breast tumours however is often limited by the development of radioresistance and damage to the surrounding normal tissue. Accordingly, combination therapies aiming to minimize radiation damage to normal tissue and/or to increase the radiosensitivity of tumours are increasingly being investigated.
In this respect, natural diatery polyphenols are attracting significant interest due to their reported chemo/radio-protective effect on normal tissue and their more recently documented anti-tumour and selective radiosensitising properties against tumour cells.
Resveratrol, a phytochemical present in grapes, has been shown to mediate anticancer activity, as well as to increase radiation sensitivity in various tumour types (Nambiar et al. 2012). Recently, we reported that [10]–Gingerol, a natural product extracted from ginger with homology to [6]-gingerol, also demonstrate anticancer activities against MDA-MB-231 breast metastatic cells in vitro.
Hence, the aim of our study was to compare the anti-tumour efficacy and radiosensitising effect of Resveratrol and [10]-gingerol in vitro against highly metastatic variant of MDA-MB-231 human breast cancer cell line (MDA-MB-231HM) and a murine brain-metastatic mammary carcinoma line (4T1Br4).
A sulforhodamine B colorimetric assay was performed to evaluate the inhibitory effect of these natural products on cell proliferation. Preliminary data indicate that Resveratrol inhibited proliferation with an IC50 of 34.7µM in MDA-MB-231HM and 3.01µM in 4T1Br4 and [10]-gingerol, 64.34µM and 41.47µM, respectively.
Additional work utilizing in vitro functional assays is currently underway to investigate the anti-metastatic and radiosensitising properties of these compounds against MDA-MB-231HM and 4T1Br4 and will be presented.