Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Cancer Immunology Group, Shiraz Institute for Cancer Research, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
Cancer Biomark. 2017;18(4):375-380. doi: 10.3233/CBM-160260.
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.
In this study, we assessed the aberrant cell surface expression of TLR9 in cancer using cell-lines model.
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.
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).
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.
Toll 样受体 9（TLR9）是先天免疫系统的 DNA 受体，在炎症反应中起着关键作用。最近的证据表明，TLR9 在多种癌细胞中过度表达和功能活跃，并促进肿瘤细胞增殖和存活。
本研究通过细胞系模型评估癌症中 TLR9 的异常细胞表面表达。
采用流式细胞术分析三种乳腺癌细胞系（MDA-MB-231、MCF7 和 SKBR3）和五种结直肠腺癌细胞系（HT29、HT29/219、SW480、SW48 和 SW1116）以及一个原代包皮分离成纤维细胞中 TLR9 的细胞表面和细胞内表达。
结直肠细胞系 HT29/219 表面 TLR9 表达最高（38.35%），而基底线成纤维细胞正常细胞（0.12%）最低。MCF-7 细胞内表达最高（35.63%），而 MDA-MB-231 则表现出最高的表面/细胞内表达（277 倍）。
基于这些结果，我们假设肿瘤细胞上 TLR9 的异常表面表达可能促进肿瘤生长和侵袭。这也可能突出 CpG-ODN 作为癌症治疗佐剂的双重矛盾作用。
