Expression of pAkt is associated with a poor prognosis in Chinese women with invasive ductal breast cancer

CRISPR/Cas9 mediated knocking out of OPN gene enhances radiosensitivity in MDA-MB-231 breast cancer cell line

PURPOSE

Although chemotherapy and radiotherapy in conjunction with surgery have been known as the standard methods for patients with breast cancer, they frequently face resistance due to the failure of cells to death. Accordingly, improving the results requires discovering novel therapeutic approaches based on the changes in the molecular biology of cancer cells. Osteopontin (OPN) is a secreted protein that previous studies have shown to be associated with progression, poor prognosis, and metastasis in breast cancer. The current study examined the synergistic effects of radiotherapy and knocking out of OPN gene, utilizing CRISPR/Cas9 technique in MDA-MB-231 breast cancer cells.

METHODS

We used to knock out the OPN gene by the two different gRNAs. The cells irradiated 24 h after transfection. The mRNA expression, tumor cell proliferation, cell cycle distribution, growth, and apoptosis were measured. Moreover, activation of Chk1 and AKT were measured via western blot.

RESULTS

We demonstrated the OPN knocking out along with radiation led to the promotion of apoptosis, suppression of downstream genes, reduction of cell viability, and inhibition of cell-cycle progression. The western blot analysis has indicated that the knocking out of the OPN gene along with radiotherapy changes DNA damage responses substantially.

CONCLUSIONS

The OPN gene knocking out with radiotherapy might be an efficient approach to overcome the radioresistance in breast cancer.

Anti-Cancer Activity of Catechin against A549 Lung Carcinoma Cells by Induction of Cyclin Kinase Inhibitor p21 and Suppression of Cyclin E1 and P–AKT

Catechin is one of the major polyphenols in teas, beans, and berry fruits. A number of studies have confirmed that catechins extract possesses health benefits in the prevention of various chronic diseases. In this study, the anti-cancer activity and mechanism of catechin against non-small cell lung cancer A549 cells were investigated. The inhibitory rate of catechin on the proliferation of A549 cells reached 19.76% at a concentration of 600 μmol·L−1 with 24 h incubation. The results demonstrated that catechin inhibits A549 cells by increasing the expressions of p21 and p27 in the cancer cells. Furthermore, the catechin treatment inhibited the expressions of cyclin E1 and phosphorylation of protein kinase (P–AKT) in a dose-dependent manner, which also contributed to the inhibition of cancer cell proliferation. Therefore, the results of this study indicated that catechin can effectively inhibit the proliferation of A549 cells through regulating its cell cycle arrest or indirectly via the p21 signaling pathway. It would provide important information for developing catechin and catechin-rich functional food or co-therapy for antitumor purposes.