The Effect of Cytokines on MicroRNA Expression in TW01 Nasopharyngeal Carcinoma Cells
Ting Wei Lee
Institute of Postgraduate Studies and Research, International Medical University, No. 126 Jalan 19/155B, Bukit Jalil, 57000 Kuala Lumpur, Malaysia.
Eng Lai Tan
School of Pharmacy, International Medical University, No. 126 Jalan 19/155B, Bukit Jalil, 57000 Kuala Lumpur, Malaysia.
Ching Ching Ng
Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
Sook Yee Gan *
School of Pharmacy, International Medical University, No. 126 Jalan 19/155B, Bukit Jalil, 57000 Kuala Lumpur, Malaysia.
*Author to whom correspondence should be addressed.
Abstract
Aims: To determine the effect of cytokines, namely transforming growth factor-beta one (TGF-β1), and interleukin-6 (IL-6) on the expression of 88 cancer-related microRNAs (miRNAs) in TW01 nasopharyngeal carcinoma (NPC) cells with or without the presence of Epstein-Barr virus latent membrane protein 1 (LMP1).
Methodology: TW01 and TW01-LMP1 cells were treated with cytokines. MicroRNAs were isolated from treated and untreated TW01/TW01-LMP1 cells and were subjected to RT-PCR array of 88 cancer-related microRNAs. The threshold cycle (Ct) data were analysed and fold-change in the level of gene expression was calculated based on ΔΔCt using two endogenous controls, SNORD 47 and SNORD 44. Data obtained from each treatment were compared with the data obtained from the respective control group (untreated TW01/ TW01-LMP1).
Results: TGF-β1 down-regulated miR-143 in TW01 NPC cells. In TW01 cells that expressed the EBV LMP1 gene (TW01-LMP1), approximately 97% of the 88 miRNAs were up-regulated by TGF-β1. Among them was miR-181c a well-known repressor of NOTCH2/4 and KRAS and has important role in cell differentiation. IL-6 up-regulated approximately 65% of the miRNAs in TW01 cells but in less than four-fold. In TW0-LMP1 cells, eight miRNAs; namely, miR-15b, miR-155, miR-16, miR-215, miR-23b, miR-25, miR-9 and miR-98 were significantly up-regulated by IL-6. Among these, miR-15b, miR-155 and miR-25 had been reported to be elevated in NPC tissues.
Conclusion: This study provides a preliminary perspective on the effects of cytokines on the expression of miRNAs in TW01 NPC cells.
Keywords: microRNA, cytokines, nasopharyngeal carcinoma, Epstein-Barr, latent membrane protein one