Introduction: Protein and gene expressions are intensively profiled for potential biomarkers in diagnosis or prognosis of diseases. The correlation between corresponding protein and mRNA of a gene is important to establish whether transcript levels of a given gene can be used as proxies for the corresponding protein levels. mRNA profiling is more commonly utilised as this method is cheaper and the technology more advanced. Acute myeloid leukaemia (AML) is a heterogeneous group of malignant precursors of the myeloid lineage that leads to death if not treated. Cytokines and death receptors are commonly evaluated in this disease in search of potential biomarkers; however, the mRNA/protein correlations of these biomarkers are still unclear. Methods: Semi-quantitative expression of mRNA expression and protein levels of IL-1β, IL-18Rα, IL-6, TNF-α and DR5 were measured by conventional polymerase reaction (PCR) and flow cytometry in 11 cases of AML at diagnosis. Correlation in the intensity of the PCR amplicon and corre-sponding mean fluorescence intensity of protein was determined by Spearman’s rank correlation test. Results: None of the cytokines/death receptor was significantly correlated except IL-6 (Rs= -0.6287, p=0.038). Unexpectedly, this was also a significant negative correlation. Conclusion: For the majority of selected biomarkers in AML, whether secreted or surface-expressed, mRNA and protein expressions were not significantly correlated. The strong negative correlation for IL-6 is worth further investigation.
Acute myeloid leukemia (AML) constitutively express growth factors and cytokines for survival. Chemotherapy alters these signals to induce cell death. However, drug resistance in AML remains a major hindrance to successful treatment and early warning is unavailable. Modulation of signaling pathways during chemotherapy may provide a window to detect response and predict treatment outcome. Blood samples collected from AML patients before and at day-3 of induction therapy were compared for changes in expression of CD117, CD34, pro-inflammatory cytokines and mediators of Akt and MAPK pathways, using multi-color flow cytometry. Nine patients were diagnosed as drug-resistant and seven sensitive to chemotherapy. Twelve were paired. Average percentages of CD34 (66.8 ± 11.7% vs. 26.2 ± 5.8%, p = 0.033) and pBAD (66.9 ± 8.2% vs. 28.9 ± 8.2%, p = 0.016) were significantly increased in chemo-resistant (N = 9) compared to chemo-sensitive (N = 5) samples. Percentages of CD34 were strongly correlated with pBAD (R = 0.785; p = 0.001; N = 14) and pFKHR (R = 0.755; p = 0.002; N = 14) at day-3 induction. Chemo-sensitive cases expressed significantly higher percentages of IL-18Rα (71.9 ± 9.6% vs. 29.8 ± 5.8%, p = 0.016). Though not significantly different in the outcome, IL-1β was strongly associated with activated Akt-S473, IL-6 with phosphorylated JNK and FKHR while TNF-α appeared to trigger Bim, in treated samples. These preliminary results suggested AML cells resistant to chemotherapy increased expression of CD34 and may signal through pBAD while cells sensitive to chemotherapy-induced IL18Rα expression. These were observed early during induction therapy. Identifying CD34 is interesting as it is a convenient marker to monitor drug-resistance in AML patients. Inhibition of CD34 and pBAD signaling may be important in treating drug-resistant AML.