Cell membrane and intracellular expression of toll-like receptor 9 (TLR9) in colorectal cancer and breast cancer cell-lines

Article type: Research Article

Authors: Shahriari, Shadab^a | Rezaeifard, Somayeh^b | Moghimi, Hamid Reza^c | Khorramizadeh, Mohammad Reza^{a; d} | Faghih, Zahra^{b; *}

Affiliations: [a] Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran | [b] Cancer Immunology Group, Shiraz Institute for Cancer Research, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran | [c] School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran | [d] Biosensor Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, EMRI, Tehran University of Medical Sciences, Tehran, Iran

Correspondence: [*] Corresponding author: Zahra Faghih, Cancer Immunology Group, Shiraz Institute for Cancer Research, School of Medicine, Shiraz University of Medical Sciences, Shiraz, P.O. Box: 71345-1798, Iran. Tel.: +98 71 3230 3687; Fax: +98 71 3230 4952; E-mail:faghihz@sums.ac.ir

Abstract: BACKGROUND: Toll-like receptor 9 (TLR9) is a DNA receptor of innate immune system which plays a pivotal role in inflammatory response. Recent evidence reveals over-expression and functionality of TLR9 in a wide variety of cancer cells and its contribution to tumor cell proliferation and survival. OBJECTIVE: In this study, we assessed the aberrant cell surface expression of TLR9 in cancer using cell-lines model. METHODS: Three breast cancer cell-lines (MDA-MB-231, MCF7 and SKBR3) and five colorectal adenocarcinoma cell-lines (HT29, HT29/219, SW480, SW48 and SW1116) in addition to one primary foreskin isolated fibroblast cell were analyzed for cell surface and intracellular expression of TLR9 by flow cytometry method. RESULTS: Maximum surface expression of TLR9 was observed in colorectal cell-line HT29/219 (38.35%), as compared with the bottom line fibroblast normal cells (0.12%). The most intracellular expression was observed in MCF-7 cells (35.63%), whereas MDA-MB-231 expressed the maximum surface/intra cellular expression (277 times). CONCLUSIONS: Based on the results, we hypothesize that aberrant surface expression of TLR9 on tumor cells may promote tumor growth and invasion. It might also highlight a dual contradictory role for CpG-ODNs, as adjutant in cancer therapy.

Keywords: TLR9, colon cancer, breast cancer

DOI: 10.3233/CBM-160260

Journal: Cancer Biomarkers, vol. 18, no. 4, pp. 375-380, 2017