Analysis of Kynurenine/Tryptophan ratio and expression of IDO1 and 2 mRNA in tumour tissue of cervical cancer patients

Abstract Objectives Indoleamine 2,3-Dioxygenase (IDO) catalyses the degradation of the essential amino acid tryptophan leading to the production of immunosuppressive Kynurenine. In the present study, we developed a modified method for measurement of Kynurenine/tryptophan (K/T) ratio in the cervical tissue using HPLC and investigated its relationship with the expression of IDO1 and 2 genes in the cervical tumour milieu. Design and Methods Cervical cancer punch biopsy samples of 27 women who presented at the Cancer Institute (WIA) were used for detection of K/T ratio by HPLC as well as expression of IDO1 and 2 at the mRNA level by Realtime PCR after obtaining Institutional ethical committee approval. Results The K/T ratio was elevated significantly in cancer cervix samples compared to normal cervix ( p p Conclusion Our preliminary data indicates that the K/T ratio at the tissue level may be investigated reliably using HPLC, as an indirect measure of IDO1 gene expression and activity.