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

 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.

 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.

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.

 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.