Investigating the expression levels of microRNAs promoting angiogenesis (miR-296 )in colon cancer samples and their pathological importance in diagnosis
Investigating the expression levels of microRNAs promoting angiogenesis (miR-296 )in colon cancer samples and their pathological importance in diagnosis
Maryam Namdi,1,*Rodabeh Behzadi,2Amin Khalili,3
1. Department of Biology, Central Tehran Branch, Islamic Azad University, Tehran, Iran 2. Department of Biology, Central Tehran Branch, Islamic Azad University, Tehran, Iran 3. Department of Biology, Central Tehran Branch, Islamic Azad University, Tehran, Iran
Introduction: Colon cancer is the third most common cancer and the second leading cause of cancer death. Early diagnosis of colon adenocarcinoma is one of the most important challenges in cancer management. Due to the importance of identifying non-coding RNAs and their stability, this study aimed to investigate the expression levels of miR-296 of serum extracellular microvesicles in patients with colon adenocarcinoma and controls. This study is likely to lead to the identification of a non-invasive diagnostic biomarker for colon adenocarcinoma.
Methods: In this study, 40 patients with colorectal adenocarcinoma and 40 healthy cases were selected for blood sampling. Then exosomal vesicles isolated from serum based on differential centrifuge protocol. The size and morphology of the exosomal Nanovesicles were assessed by SEM electron microscopy. After RNA extraction from the exosomes was performed using trisol, polyadenylation and cDNA synthesis. The expression level of miR-296 was compared with the expression of U6snRNA gene as a reference gene for normalization of data in the patient's exosome with a healthy sample by real-time PCR.
Results: The findings of this study showed that the isolated exosomes have a spherical appearance with a size range of 30 to 150 nm. After real-time PCR, in Roc curve analysis, Area under curve (AUC) was calculated to be 0.76 for miR-296. Also, the ΔCt parameter showed a significant difference in serum exosomes of patients compared to healthy exosomal samples, miR-296 expression level was significantly higher in serum exosomes of colon adenocarcinoma than in normal serum exosomes. (P <0. 01). The expression level of miR-296 in Stage 3 shows a higher expression than Stages 1 and 2 (P <0.05). Also, the expression level of miR-296 in patients with lymph node metastasis showed higher expression than patients with no lymph node involvement (P <0.01).
Conclusion: The results showed that increased expression of miR-296 and miR-93 in the serum exosomes of patients compared to healthy samples could be a criterion for the diagnosis of colorectal cancer. In addition, the expression of these two miRNAs with the clinical pathological features of the disease can confirm their biomarker potential.