Induction of apoptosis and cell cycle arrest in colorectal cancer cells by novel anticancer metabolites of Streptomyces sp. 801.

BACKGROUND: Colorectal cancer is the third and most significant cause of death and fourth most common cancer in the world. Chemotherapy can be introduced in the cases of locally or distantly invasive colorectal cancer. In recent years Actinomycetes, especially the genus Streptomyces, contain numerous bioactive compounds, some of which are known as important anti-tumor chemotherapy drugs. In this research, we aimed to explore the anti-cancer mode of action of Streptomyces sp. 801 on colorectal cancer cells in vitro conditions. METHODS: Fermented supernatant of strain Streptomyces sp. 801 isolated from soil showed maximum growth inhibition on human colorectal cancer cells. The cytotoxic effects of various concentrations of EtOAc extract from bacterial culture supernatant on HT-29, HCT 116 and SW480 cancer cells were surveyed using the MTT assay. Moreover, flow cytometry assays and Bax, Bcl-2, Cyclin D1 and P21 gene expressions were carried out to assess the apoptotic and cell cycle effects. Also, the scratch assay was performed to measure migration. Finally, Ethyl acetate (EtOAc) extract was analyzed by LC-MS to identify anti-cancer compounds. RESULTS: The cell viability of all three cell lines were decreased in a dose-dependent manner. The successful induction of apoptosis and cell cycle arrest at IC50 values, were confirmed by flow cytometry as well as by the mRNA expression levels of the genes involved in these processes. Scratch assays indicated the inhibition of cell migration in the cancer cell lines treated by Streptomyces sp. 801. Nine anti-cancer compounds of Streptomyces sp. 801 were detected by liquid chromatography-mass spectrometry (LC-MS) analysis. CONCLUSIONS: These findings suggest that Streptomyces sp. 801 can be a source of promising anticancer metabolites.

Association between 318C/T polymorphism of the CTLA-4 gene and systemic lupus erythematosus in Iranian patients.

BACKGROUND: Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) is an important negative regulator of T-cell response. It is a functional candidate gene connected with susceptibility to systemic lupus erythematosus (SLE). We analyzed the role of -318C/T polymorphism in the promoter region of the CTLA-4 gene in Iranian patients suffering from SLE. METHODS: A total of 180 SLE patients and 304 healthy ethnically matched controls were enrolled in the study. DNA was extracted from blood samples according to the standard procedure. Polymerase chain reaction restriction fragments length polymorphism (PCR-RFLP) was used to analyze the genotype and allele frequencies of these polymorphisms. RESULTS: The CC genotype was observed in 170 (94.5%) of the SLE patients, which was significantly different compared to the controls (251 [82.4%]; P = 0.0001, OR = 3.51 95%CI = 1.77-7.53). T allele was significantly more common in the controls (9.2%) compared to SLE patients 2.8% (P = 0.0001, OR = 0.26, 95%CI = 0.13-0.53). There was no significant correlation between different genotypes and age, gender or family history of SLE in the studied population. CONCLUSION: It can be concluded that -318C/T polymorphism of CTLA-4 gene might play a significant role in the development of SLE in the Iranian patients.

Endothelial nitric oxide synthase VNTR (intron 4 a/b) polymorphism association with type 2 diabetes and its chronic complications.

UNLABELLED: SUBJECT AND AIMS: Endothelial derived nitric oxide (eNOS) is involved in several functions playing important role in development of type 2 diabetes and insulin resistance. The aim of this study was to examine the association between eNOS intron 4 VNTR polymorphism and type 2 diabetes in an Iranian population. METHODS: A total of 220 patients with type 2 diabetes and 96 healthy control subjects were recruited from the same area. Genotyping was performed using PCR. RESULTS: A significant difference was found in genotype frequencies of eNOS polymorphism between patients and controls (aa+ab vs. bb p=0.02, OR 2.0 95% CI; 1.05-3.96). Also allele a frequency was significantly increased in patients with diabetes compared with controls (p=0.007, OR 2.1 95% CI; 1.19-4.08). We found that in patients with diabetic neuropathy the frequency of 'a' allele was significantly increased compared to the controls p=0.03, OR=1.8 95% CI (1.00-3.7). Both genotype and allele frequencies were significantly different between patients who were complication free compared to the controls [aa+ab vs. bb p=0.007, OR=2.6 95% CI (1.2-5.8) and p=0.001, OR=2.8 95% CI (1.4-5.9)] respectively with the a allele conferring the risk. CONCLUSION: The association between eNOS VNTR polymorphism and T2DM seems to be stronger in patients without diabetic complications indicating diverse effect of eNOS polymorphism on diabetes and diabetic microvascular complications.