Circulating microRNA Panel as a Potential Novel Biomarker for Oral Squamous Cell Carcinoma Diagnosis

Abstract

A lack of reliable biomarkers for oral squamous cell carcinoma (OSCC) poses a major clinical issue. The sensitivity and specificity of classical serum tumor markers, such as the squamous cell carcinoma antigen (SCC-Ag), are quite poor, especially for early detection. This study aimed to identify specific serum miRNAs potentially serving as OSCC biomarkers. The expression levels of candidate miRNAs in serum samples from 40 OSCC patients and 40 healthy controls were quantitatively analyzed via microarray and reverse transcription PCR (RT-PCR) analyses. To enhance the accuracy of detection, we used Fisher's linear discriminant analysis to establish a diagnostic model that incorporated a combination of selected miRNAs. Consequently, miR-19a and miR-20a were significantly upregulated in the patient group (p = 0.014 and 0.036, respectively), whereas miR-5100 was downregulated (p = 0.001). We found that a combination of six miRNAs (miR-24, miR-20a, miR-122, miR-150, miR-4419a, and miR-5100) could distinguish between OSCC and the control group with a higher degree of accuracy (Area Under the Curve, AUC: 0.844, sensitivity: 55%, and specificity: 92.5%). Furthermore, compared to serum SCC antigen, the 6-miRNA panel could accurately detect the presence of OSCC. The present specific miRNAs panel may serve as a novel candidate biomarker of oral cancer.

Keywords: biomarker; microRNA; oral cancer; oral squamous cell carcinoma; tumor marker.

Figure 1

Comprehensive analysis of serum miRNA using a microarray. Microarray analysis detected 48 upregulated and 40 downregulated oral squamous cell carcinoma (OSCC)-specific miRNAs in patients, compared to healthy controls.

Figure 2

Flow diagram for detection of candidate microRNAs.

Figure 3

Comparison of normalized signal intensities of three microRNAs in oral squamous cell carcinoma (OSCC) patients and the control group. Signal intensities of three microRNAs, miR-20a, miR-19a, and miR-5100, were significantly different (Wilcoxon test, p < 0.05). Relative expression levels were significantly increased in miR-19a and miR-20a of OSCC patients, whereas miR-5100 of the control group showed a higher intensity.

Figure 4

Receiver operating characteristic (ROC) analyses for miR-20a, miR-19a, and miR-5100 indicating a relatively higher area under the curve (AUC).

Figure 5

The diagnostic performance of the models was investigated using a combination of miRNAs. (a) Using the Fisher’s linear discriminant analysis, the diagnostic index (named as miRNA index) was expressed as Equation (1). (b) The level of the miRNA index Q-TPJ, Chen Z. in other references in the listed 10 authors were listed prior to the additional meaning. NPV is also appropriate here, which was demonstrated to be significantly higher in the oral squamous cell carcinoma (OSCC) patient group than that in the control group. (p < 0.0001, Wilcoxon test). (c) Diagnostic performance for OSCC detection by the miRNA index using the cutoff value.

Figure 6

The diagnostic performance of the combination of miRNAs compared with that of a conventional serum tumor marker. (a) The miRNA index level of the OSCC group (OSCC pre-surgery) was significantly higher than that of the post-surgery OSCC group and the control group (p < 0.0001 and p = 0.0033, respectively, Wilcoxon test). (b) The serum squamous cell carcinoma (SCC) antigen level showed no significant difference between pre-surgery and post-surgery OSCC groups (p = 0.79, Wilcoxon test).