The expression of genes KRAS, DPM1, ACRV1, and MBD3L2 in the saliva as potential tumor markers in the detection of pancreatic cancer

<b>Introduction:</b> Pancreatic cancer is still an unresolved, significant diagnostic and clinical problem. An ideal tumor marker with a high sensitivity, organ specificity, and prognostic value that correlates with tumor stages and eliminates the imperfection of preoperative serum carbohydrate antigen 19-9 (CA 19-9) concentration is still being sought.<b>Aim:</b> This study aimed to conduct a comparative analysis expression of genes <i>KRAS, DPM1, ACRV1</i>, and <i>MBD3L2</i> in the saliva of patients with pancreatic cancer (PC) and a control group (CG).<b>Material and methods:</b> The study was performed on a group of 55 patients. Group 1 consisted of 44 patients with PC, group 2 (CG) consisted of 11 individuals who were recruited among patients operated on for non-inflammatory cholelithiasis. Group 1 was divided into 2 subgroups group 1a, 19 patients with resectable pancreatic tumors, and group 1b, 25 patients with unresectable pancreatic tumors. The saliva samples were taken from patients twice, before surgery and 10 days after surgery, and the expression of genes <i>KRAS, DPM1, ACRV1</i>, and <i>MBD3L2</i> in the saliva was evaluated. Gene expression at the transcriptional level was analyzed by assessing the number of mRNA copies using the reverse transcriptase reaction and polymerase chain reaction (RT-PCR).<b>Results:</b> The revealed expression of genetic cancer biomarkers (CB) (<i>KRAS, DPM1, ACRV1, MBD3L2</i>) in saliva was statistically significantly higher in the PC group in comparison to CG. There was a statistically significant decrease in the <i>KRAS</i> gene expression and a statistically significant increase in the <i>MBD3L2</i> expression in patients in subgroup 1a, 10 days after resection procedures. The revealed serum concentration of CA 19-9 was significantly higher in subgroup 1b in comparison to subgroup 1a. Although higher gene expression of <i>KRAS, DPM1</i>, and <i>MBD3L2 </i>was observed in subgroup 1b, no statistical significance was obtained. A statistically significant correlation between <i>DPM1</i> expression and serum CA 19-9 level in the PC group was observed. There were statistically significant differences in <i>KRAS </i>and <i>DPM1</i> expression depending on the tumor stage in the TNM/UICC classification regarding to T and N category. A significant difference in <i>MBD3L2</i> expression was observed in N category. A statistically significant increase in the expression of <i>KRAS, DPM1</i>, and <i>MBD3L2 </i>was observed in the case of neoplastic infiltration of blood vessels, and a significant increase in the expression of <i>KRAS</i> and <i>MBD3L2 <i/>in the case of neoplastic infiltration of nerve fibers.<b>Conclusions:</b> Presented findings suggest the usefulness of the salivary transcriptome profiles in distinguishing patients with PC from healthy controls but its usefulness in the differential diagnosis between resectable and unresectable PC is limited. However, more studies on a large population are needed to support our result.