مقالات پذیرفته شده در سومین کنگره بین المللی زیست پزشکی
The role of Bcl-2 family members in anti-proliferation and apoptotic inducing effect of Calprotectin (S100A8/S100A9)
The role of Bcl-2 family members in anti-proliferation and apoptotic inducing effect of Calprotectin (S100A8/S100A9)
Fatemeh shabani,1,*Nematollah Gheibi,2Majid Mahdavi1 ,3
1. Department of Biology, Faculty of Natural Science, University of Tabriz 2. Cellular and Molecular Research Center, Qazvin University of Medical Sciences 3. Department of Biology, Faculty of Natural Science, University of Tabriz
Introduction: Introduction: Calprotectin, a member of S100s proteins, is a heterodimeric complex of EF-hand calcium-binding protein consisting of S100A8 and S100A9 subunits and constitutively expressed by phagocytes like neutrophils and secreted from activated phagocytes. It is also a zinc and manganese chelator which can inhibit microbial growth and activity of zinc-dependent enzymes such as: matrix metalloproteinase. Calprotectin is a key protein between cancer and inflammation. at low concentration, it involves in immune response, survival and proliferation, inflammation and cancer whereas induces apoptosis in higher concentration. It should be noted that in the normal conditions, the concentration of calprotectin in human serum is less than 1 μg/ml, which increase in such inflammatory disease including: inflammatory bowel disease (IBD), rheumatoid arthritis (RA), cystic fibrosis, chronic bronchitis, autoimmune disease and many types of cancers and neurodegenerative disorders such as Alzheimer. It is suggested that calprotectin can be considered as a significant marker for diagnostic purposesSince the cancer cells have developed various mechanisms to resist cell death so apoptosis is known as an efficient strategy for control and treatment of cancer. The aim of this study was to evaluate the effects of recombinant human calprotectin (rhS100A8/A9) in the adenocarcinoma AGS, the most common type of gastric cancer cell line.
Methods: Methods: The AGS cells were exposed to the different concentrations (5-100 µg/mL) of calprotectin for 24, 48 and 72 hours. Cell viability and apoptotic effects of calprotectin were assessed by using MTT assay and Annexin V/PI double staining assay, respectively. Furthermore, real-time PCR and western blot were performed for evaluation of the Bax and Bcl2 genes expression and proteins level in AGS treated with and without calprotectin by real-time PCR and Western blot analysis which provide important insight into the molecular mechanisms of S100A8/A9-inducing apoptotic
Results: Results: We observed cytotoxicity and apoptotic effects of calprotectin on AGS cells in a time- and concentration-dependent manner. the results of MTT-assay and flow cytometry show that this protein has an inhibitory effect on the cancer cells proliferation and reduced viability and induced apoptosis in AGS cell lines. Considering our finding from real time PCR technique, a significantly decrease in Bcl2/Bax genes expression ratio has been seen and we can say induction of apoptosis by calprotectin was achieved by down-regulation of Bcl2 and up-regulation of Bax. Due to the quantified data from Western blot analysis, altered ratio of Bax/Bcl2 can trigger the intrinsic or mitochondrial pathway of apoptosis. Therefore, altered ratio of pro-apoptotic and anti-apoptotic Bcl2 family members might be an important key question to understand the sensitizing effect of calprotectin on cancer cells.
Conclusion: Conclusion: These findings indicated that calprotectin inhibits the proliferation and induces apoptosis in the AGS cells by regulating of Bcl2 family and may be useful for the treatment of cancer. Calprotectin is an important biological marker and a good crosstalk factor between cancer and inflammation and protein design aims to identify new protein sequences of desirable structure and biological function in apoptosis inducing, not inflammation stimulating, can be considered in the future.