Investigating the TLR9 mRNA Expression Level in Different Histological Types of Colorectal Polyps.

Sama Rezasoltani,Maryam Sharafkhah,Zahra Pezeshkiyan,Ehsan Nazemalhosseini-Mojarad,Mohammad Reza Zali,Amir Sadeghi,Hamid Asadzadeh Aghdaei,Shirin Khatibi

doi:10.31557/apjcp.2019.20.8.2299

Abstract

Toll-like receptor 9 (TLR9) is a cellular DNA receptor of the innate immune system which plays a pivotal role in inflammatory response. Recently, changing expression levels of TLR9 has been observed in a wide range of cancer cells; however, there is little information about colorectal polyps. Herein, we assessed the mRNA expression of TLR9 in different colorectal polyp types compared to normal group in order to investigate its expression level during CRC initiation. Fifty-four biopsy samples from colorectal polyp patients and from 20 healthy subjects were collected. The mucosal mRNA expression level of TLR9 gene was identified by real time PCR. Fold change of gene expression was evaluated by 2-ΔΔct method. There was a significant relationship between the lower expression of TLR9 gene in the polyp cases compared to normal individuals (P value = 0.0005), Also, decreased TLR9 mRNA expression was obtained in adenomas in contrast to hyperplastic and normal groups (P value = 0.0008). Based on the current results, we hypothesized that aberrant surface expression of TLR9 on tumor cells may promote the growth and invasion of colorectal polyps. Further, TLR9 modulation may have an important impact on the development of novel therapeutic strategies.

Highlights

Colorectal cancer (CRC) is a considerable global health problem in the world and the third diagnosed malignancy following lung and breast cancer (Peters et al, 2016; Hale et al, 2017)
There was a significant relationship between the lower expression of Toll-like receptor 9 (TLR9) gene in the polyp cases compared to normal individuals (P value = 0.0005), decreased TLR9 mRNA expression was obtained in adenomas in contrast to hyperplastic and normal groups (P value = 0.0008)
It was found that TLR-9 mRNA expression was reduced in adenomatous polyps (AP) and HP cases compared with the normal individuals; it was suggested that reduction of TLR-9 may play an important role in CRC initiation

Summary

Introduction

Colorectal cancer (CRC) is a considerable global health problem in the world and the third diagnosed malignancy following lung and breast cancer (Peters et al, 2016; Hale et al, 2017). Most CRC cases progress from precursors recognized as colorectal polyps; the two common types of polyps include: hyperplastic (HP) and adenomatous polyps (AP). Colorectal polyps are found in different shapes including adenoma, hyperplastic, hamartomatous, and inflammatory polyps (Leslie et al, 2002). Recent investigations have revealed that hyperplastic polyps have the malignancy potential in some cases (Liljegren et al, 2003; Inoue et al, 2007). The relationship between inflammation and tumor is becoming increasingly important in the study on the pathogenesis of CRC. Several studies have confirmed that TLRs as immune molecules could mediate inflammatory response and play an important role in this process (Chen et al, 2007; Kolumam et al, 2005; Siegel et al, 2016). We dealt with evaluating the expression level of the TLR9 in colonic AP and HP cases in contrast to healthy subjects and with finding the relationship between TLR9 mRNA expression level and pathological features of AP and HP cases

Methods

Results

Conclusion