Background and aims: Studies have shown that a HOXB13:IL17BR expression ratio index predicts clinical outcome in ER-positive, lymph node-negative breast cancer patients that treated with adjuvant tamoxifen. All of these experiments were conducted with qReal Time RT-PCR using TaqMan probes. The aim of this study was to determine the ratio using SYBR Green I qReal Time RT-PCR.
Methods: In this case- control study, expression levels of HOXB13:IL17BR was measured in
40 paired formalin-fixed, paraffin-embedded primary breast tumor specimens. After extracting RNA from the tissues, cDNA synthesis and amplification with the polymerase chain reaction to obtain the optimum annealing temperature, the expression levels was measured by SYBR Green I qReal Time RT-PCR. To determine and normalize the expression levels, BestKeeper software was used to obtain the BestKeeper Index using the geometric mean of expression levels of housekeeping genes. Comparison of mean expression of genes between tumoral and non-tumoral tissues was performed by t-test and association between patient grouping (high/low risk) and time for disease free survival was assessed by Fisher`s Exact test.
Results: HOXB13:IL17BR expression value did not show significant difference between tumoral and non-tumoral tissues. The results showed that there was a direct and significant association between patient grouping (based on HOXB13:IL17BR ratio) and disease free survival status.
Conclusion: Results in the current study showed that in spite of using SYBR Green dye (instead of TaqMan probes), there is still a significant correlation between HOXB13:IL17BR ratio and disease free survival status
