Abstract. Cancer is a public health problem in the world and breast cancer is the most frequently cancer in women. Approximately 15% of the breast cancers are triple-negative. Apoptosis regulates normal growth, homeostasis, development, embryogenesis and appropriate strategy to treat cancer. Bax is a protein pro-apoptotic enhancer of apoptosis in contrast to Bcl-2 with antiapoptotic properties. Initiator caspase-9 and caspase-8 are features of intrinsic and extrinsic apoptosis pathway, respectively. NF-κB is a transcription factor known to be involved in the initiation and progression of breast cancer. Noscapine, an alkaloid derived from opium is used as antitussive and showed antitumor properties that induced apoptosis in cancer cell lines. The aim of the present study was to determine the apoptotic effect of noscapine in breast cancer cell lines compared to breast normal cell line. Three cell lines were used: i) a control breast cell line MCF-10F; ii) a luminallike adenocarcinoma triple-positive breast cell line MCF-7; iii) breast cancer triple-negative cell line MDA-MB-231. Our results showed that noscapine had lower toxicity in normal cells and was an effective anticancer agent that induced apoptosis in breast cancer cells because it increases Bax gene and protein expression in three cell lines, while decreases Bcl-xL gene expression, and Bcl-2 protein expression decreased in breast cancer cell lines. Therefore, Bax/Bcl-2 ratio increased in the three cell lines. This drug increased caspase-9 gene expression in breast cancer cell lines and caspase-8 gene expression increased in MCF-10F and MDA-MB-231. Furthermore, it increased cleavage of caspase-8, suggesting that noscapineinduced apoptosis is probably due to the involvement of extrinsic and intrinsic apoptosis pathways. Antiapoptotic gene and protein expression diminished and proapoptotic gene and protein expression increased noscapine-induced expression, probably due to decrease in NF-κB gene and protein expression and also by increase of IκBα gene expression induced by this drug.
IntroductionCancer is a leading cause of death in both more and less economically developed countries; the burden is expected to grow worldwide due to the growth and aging of the population and improvements in early detection and treatment (1). Cancer is a major public health problem in many parts of the world. It is currently the second leading cause of death in the United States (1,2). Breast cancer, is the most frequently occurring cancer in women and some cases show slow growth with excellent prognosis, while aggressive tumors have poor prognosis (1-3). Breast tumors have also been identified into different subtypes based on the expression of estrogen receptors (ER), progesterone receptors (PR) and Her2 oncogene. The breast tumors that do not express ER, PR or Her2 are called triple-negative breast cancers and ~15% of the breast cancers fall into this category (3,4).Apoptosis is a process of programmed cell death that occurs in response to environmental stimuli and normal gro...