Investigating the expression levels of microRNAs promoting angiogenesis (miR-93) in colon cancer samples and their pathological importance in diagnosis
Investigating the expression levels of microRNAs promoting angiogenesis (miR-93) in colon cancer samples and their pathological importance in diagnosis
Maryam Namdi,1Rodabeh Behzadi,2,*Amin 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-93 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-93 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 the Roc curve analysis, the area under the curve (Area under curve, AUC) for miR-93 was calculated to be 0.74. Examination by ΔCt parameter also showed a significant difference in the serum exosome of patients compared to healthy exosomal samples. This ratio of miR-93 expression in the serum exosome of colon adenocarcinoma was significantly higher than normal serum exosome (P <0.01). The expression level of miR-93 in Stage 3 showed higher expression than Stages 1 and 2 (P <0.05). The expression level of miR-93 in patients with lymph node metastasis was higher than in patients without lymph node involvement (P <0.01).
Conclusion: The results showed that increased expression of 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.