Circulating Serum miRNAs as Diagnostic Markers for Colorectal Cancer

<div><p>Aim</p><p>The study was designed to assess the possibility of using circulating miRNAs (serum miRNAs) as diagnostic biomarkers in colorectal cancer (CRC) and to identify their possibility as candidates for targeted therapy.</p><p>Methods</p><p>The study involved two sample sets: 1- a training set which included 90 patients with colorectal related disease (30 with CRC, 18 with inflammatory bowel disease (IBD), 18 with colonic polyps (CP) and 24 with different colonic symptoms but without any colonoscopic abnormality who were enrolled as control group) and 2- a validation set which included 100 CRC patients. Serum miRNAs were extracted from all subjects to assess the expression profiles for the following miRNAs (<i>miR-17</i>, <i>miR-18a</i>, <i>miR-19a</i>, <i>miR-19b</i>, <i>miR-20a</i>, <i>miR-21</i>, <i>miR-146a</i>, <i>miR-223</i>, <i>miR-24</i>, <i>miR-454</i>, <i>miR-183</i>, <i>miR-135a</i>, <i>miR- 135b and miR- 92a</i>) using the custom miScript miRNA PCR-based sybergreen array. The area under the receiver operating characteristic curve (AUC) was used to evaluate the diagnostic performance of the studied miRNAs for colorectal cancer diagnosis.</p><p>Results</p><p>Data analysis of miRNA from the training set showed that; compared to control group, only <b><i>miR-19b</i></b> was significantly up-regulated in patients with IBD group (fold change = 5.24, p = 0.016), whereas in patients with colonic polyps, <b><i>miR-18a</i></b> was significantly up-regulated (fold change = 3.49, p-value = 0.018). On the other hand, <i>miR-17</i>, <i>miR-19a</i>, <i>miR-20a and</i> <b><i>miR-223</i></b> were significantly up-regulated (fold change = 2.35, 3.07, 2.38 and 10.35; respectively and p-value = 0.02, 0.015, 0.017 and 0.016; respectively in CRC patients. However, the validation set showed that only <b><i>miR-223</i></b> was significantly up-regulated in CRC patients (fold change = 4.06, p-value = 0.04).</p><p>Conclusion</p><p>Aberrant miRNA expressions are highly involved in the cascade of colorectal carcinogenesis. We have found that (<i>miR-17</i>, <i>miR-19a</i>, <i>miR-20a and miR-223</i>) could be used as diagnostic biomarkers for CRC. On the other hand, <i>miR-19b</i> and <i>miR-18a</i> could be used as diagnostic biomarkers for CP and IBD respectively.</p></div

The clinical data of the studied groups.

<p>The clinical data of the studied groups.</p

Differential expression of the studied miRNAs in CRC group compared to control group.

<p>Differential expression of the studied miRNAs in CRC group compared to control group.</p

Differential expression of the studied miRNAs in CRC validation set versus control group.

<p>Differential expression of the studied miRNAs in CRC validation set versus control group.</p

Volcano plot shows differential expression of 14-miRNAs in the CRC group versus the control group.

<p><i>miR-17</i>,<i>miR-19a</i>.<i>miR-20a and miR-233</i> were significantly up regulated. B) ROC curve analysis of <i>miR-17</i>,<i>miR-19a</i>.<i>miR-20a and miR-233</i> between the CRC group and the control group. C) The clustergram performs hierarchical clustering of the entire dataset to display a heat map with dendrograms indicating co-regulated genes across control, IBD, colonic polyps and CRC groups respectively.</p

ROC curve analysis of individual miRNAs among the studied groups.

<p>ROC curve analysis of individual miRNAs among the studied groups.</p