The evaluation of TLR1, TLR2, TLR4, TLR7, and TLR8 expression levels in the newly-diagnosed acute myeloid leukemia (AML) patients

Abstract

Background: Acute myeloid leukemia (AML) is described by the clonal expansion of myeloid blasts with abnormal differentiation. Considering the role of Toll-like receptors (TLRs) in inflammation induction and the effect of chronic inflammation on cancer development, investigating the state of TLRs’ expression in human malignancies has attracted scientists’ attention. Methods: In this study, 36 newly-diagnosed AML patients and 36 control samples were examined. The mRNA expression levels of TLR1/2/4/7/8 were measured in both groups using real-time PCR. The student’s t-test was utilized to compare gene expression levels between the two populations and the one-way ANOVA test was used to compare data among multiple subtypes. Results: All TLR gene expression levels were significantly up-regulated in patients compared to the control group (p<0.05). Positive correlations between different TLRs were observed as well. AML patients under the age of 55 showed significantly higher TLR1/2/4 expression in comparison with healthy individuals of the same age; a similar comparison in people above 55 also showed an elevated expression of TLR1/2/4/8. Male patients overexpressed almost all genes compared to healthy subjects; the levels of TLR1/2/4 were also higher in female patients. No difference was observed comparing blast percentages and FAB subtypes. Conclusion: By considering the results of this experiment, it seems that TLRs up-regulation in AML patients may contribute to the pathogenesis and development of the disease; however, more investigations are required to elucidate the exact roles of these receptors in AML.

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