Resveratrol Induces Apoptosis and Attenuates Proliferation of MCF-7 Cells in Combination with Radiation and Hyperthermia.

AIM: In the current in vitro study, we tried to examine the possible role of resveratrol as a sensitizer in combination with radiotherapy or hyperthermia. BACKGROUND: Breast cancer is the most common malignancy for women and one of the most common worldwide. It has been suggested that using non-invasive radiotherapy alone cannot eliminate cancer cells. Hyperthermia, which is an adjuvant modality, induces cancer cell death mainly through apoptosis and necrosis. However, cancer cells can also develop resistance to this modality. OBJECTIVE: The objective of this study was to determine possible potentiation of apoptosis when MCF-7 cells treated with resveratrol before hyperthermia or radiotherapy. METHODS: MCF-7 cancer cells were treated with different doses of resveratrol to achieve IC50%. Afterwards, cells treated with the achieved concentration of resveratrol were exposed to radiation or hyperthermia. Proliferation, apoptosis and the expression of pro-apoptotic genes were evaluated using flow cytometry, MTT assay and real-time PCR. Results for each combination therapy were compared to radiotherapy or hyperthermia without resveratrol. RESULTS: Both irradiation or hyperthermia could reduce the viability of MCF-7 cells. Furthermore, the regulation of Bax and caspase genes increased, while Bcl-2 gene expression reduced. Resveratrol potentiated the effects of radiation and hyperthermia on MCF-7 cells. CONCLUSION: Results of this study suggest that resveratrol is able to induce the regulation of pro-apoptotic genes and attenuate the viability of MCF-7 cells. This may indicate the sensitizing effect of resveratrol in combination with both radiotherapy and hyperthermia.

The anti-aging protein klotho alleviates injury of nigrostriatal dopaminergic pathway in 6-hydroxydopamine rat model of Parkinson's disease: Involvement of PKA/CaMKII/CREB signaling.

Parkinson's disease (PD) is a prevalent movement disorder in the elderly. PD is hallmarked with progressive deterioration of mesencephalic dopaminergic neurons and development of debilitating motor and non-motor clinical symptoms. Klotho protein is the product of an aging-suppressor gene that its overexpression could protect neurons against oxidative injury. This study was undertaken to explore whether exogenous klotho could alleviate injury of nigrostriatal dopaminergic pathway in 6-hydroxydopamine (6-OHDA) rat model of PD. Intrastriatal 6-OHDA-lesioned rats were pretreated with klotho at a dose of 10µg/rat. Results showed that klotho mitigates apomorphine-induced rotational behavior and reduces the latency to initiate and the total time in the narrow beam test. In addition, beneficial effect of klotho was attenuated following i.c.v. microinjection of protein kinase A (PKA) inhibitor H-89 and Ca(2+)/calmodulin-dependent protein kinase II (CamKII) inhibitor KN-62. Additionally, klotho significantly lowered striatal levels of malondialdehyde (MDA), reactive oxygen species (ROS), glial fibrillary acid protein (GFAP), α synuclein, phospho-cAMP-response element binding protein (pCREB), and DNA fragmentation. Furthermore, klotho was capable to prevent degeneration of tyrosine hydroxylase (TH)-positive neurons within substantia nigra pars compacta (SNC). Collectively, these findings denote neuroprotective potential of exogenous klotho in 6-OHDA rat model of PD through alleviation of astrogliosis, apoptosis, and oxidative stress. It was also obtained that part of its protective effect is dependent on PKA/CaMKII/CREB signaling cascade.