Apoptosis Effects of Oxalis corniculata L. Extract on Human MCF-7 Breast Cancer Cell Line:.

Background: Recently, the non-toxic properties of natural plant products have gained more focus as anticancer agents. Therefore, this study aimed to assess the apoptosis effects of the ethanolic extract of Oxalis corniculata on the MCF-7 breast cancer cell line.Materials and Methods: In this experimental study, aerial parts of O. corniculata were collected in Lahijan city (Iran), and after confirmation, they were dried and extracted with ethanol for 24 h. Then, the total phenolic and flavonoid contents of the extract were measured. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay was used to measure the antioxidant properties of the extract. Selected cell lines (MCF-7 and human dermal fibroblast) were cultured in 6-wells dishes (1×106 cells/well). After 72 h of treating the extract, cytotoxicity was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. The expression of apoptotic genes (such as p53, bcl-2, bax, and CD95) was studied by real-time polymerase chain reaction (PCR). Results: The extract's total phenolic content was 31.30±02 µg of gallic acid equivalents/mg of dry extract, and the total flavonoid content was 49.61±04 µg of quercetin as equivalents/mg of extract. The antioxidant activity ofO. corniculata was measured at the dose of 619.2 µg/µl, indicating that it decreases cancer cell viability and enhances apoptosis. Within the half maximal inhibitory concentrations, real-time PCR revealed substantial increases in p53 (P<0.001), CD95 (P<0.05), and bcl-2 expression (P<0.05) in MCF-7 cells treated with O. corniculata. Conclusion: This study suggests that O. corniculata may cause apoptosis by oxidative stress in cancer cells.[GMJ.2022;11:e2484].

Preliminary study on the effect of nucleolin specific aptamer-miRNA let-7d chimera on Janus kinase-2 expression level and activity in gastric cancer (MKN-45) cells.

Recently, much attention has been focused on the use of miRNAs in cancer treatment. The role of proto-oncogene Janus kinase-2 (JAK-2) in proliferation and survival of gastric cancer has been previously documented. The aim of this study was to evaluate the effect of a chimera consisted of nucleolin specific aptamer (NCL-Apt) and miRNA let-7d on JAK2 expression level and activity in gastric cancer cells. NCL-Apt-miRNA let-7d chimera was prepared by two methods. Gastric cancer (MKN-45) cell line and control cell line of human dermal fibroblast (HDF) were treated with the chimera and the changes in JAK2 expression and activity were determined using real-time PCR and ELISA techniques, respectively. In MKN-45 cells, the chimera caused significant decrease in JAK2 expression level and activity compared to the aptamer alone and miRNA mimic negative control. Nevertheless, transfected miRNA let-7d showed remarkable reduction in the expression level of JAK2 in comparison with control state in both MKN-45 and HDF, confirmed unspecific effect of let-7d on normal and cancerous cells. With regard to the synergic effect of this chimera on JAK2 activity, it might be viewed as a therapeutic candidate in gastric cancer. However, further studies are warranted to prove it.

Aptamer-based Targeted Delivery of miRNA let-7d to Gastric Cancer Cells as a Novel Anti-Tumor Therapeutic Agent.

miRNAs as one of the potential therapeutic agents have been recently considered for cancer treatment. AS1411 (aptNCL) is a DNA aptamer specifically binding to nucleolin protein on the cancer cell surface with antiproliferative effect. The aim of the study was to develop a conjugate consisting of aptNCL (as targeted delivery of therapeutic agent) and miRNA let-7d (as a tumor suppressor) using two different linking methods and also to evaluate the potential effect of the conjugates on the proliferation of gastric cancer (MKN-45) cell line compared to negative control cell line of human dermal fibroblast (HDF). Conjugation was performed covalently by SM (PEG)2 as a bifunctional crosslinker (conjugate-1) and noncovalently, using 19bp complementary sticky end sequences (conjugate-2). Nucleolin positive MKN-45 and nucleolin negative HDF cells were cultured and treated with the conjugates. Then, the changes in let-7d expression and cell proliferation were determined using Real-time PCR and MTT methods, respectively. In MKN-45 cells, the conjugates caused significant increase in let7-d uptake compared with HDF cells (P = 0.0001). The conjugate-1, likely due to its higher stability compared with the conjugate-2, led to significantly more increase in intracellular let-7d in MKN-45 cells (30 fold versus 15 fold, respectively, P = 0.0001). The conjugates revealed more potent antiproliferative effect against gastric cancer cells compared with aptNCL alone (P = 0.0001). It was found that the aptNCL-let-7d conjugate efficiently carried let-7d into the cancer cells. Also, it appears that in the setting of aptNCL-let-7d conjugate, let-7d and aptNCL moieties could cooperate and synergistically exhibit the antiproliferative effect on cancer cells.