High PTPRQ Expression and Its Relationship to Expression of PTPRZ1 and the Presence of KRAS Mutations in Colorectal Cancer Tissues.

BACKGROUND

The risk of sporadic colorectal cancer (CRC) is strongly influenced by Iifestyle, environmental and genetic factors. Protein tyrosine phosphatases belong to a group of enzymes whose role in CRC has not yet been intensively studied. They play an important role in activation/de-activation of many enzymes, influencing cell biology by catalyzing reactions opposing those catalyzed by kinases. Protein tyrosine phosphatase receptor-like type Q (PTPRQ) and protein tyrosine phosphatase receptor-like type Z polypeptide 1 (PTPRZ1) have both been shown to be important in development of many cancer types including CRC.

MATERIALS AND METHODS

The expression level of PTPRQ and PTPRZ1 was determined by real-time polymerase chain reaction in 16 CRC tissues obtained from patients diagnosed with adenocarcinoma coli.

RESULTS

We revealed a high level of PTPRQ expression (p=0.0080), as well as an association between expression levels of PTPRQ and PTPRZ1 (p<0.0001). Moreover PTPRQ expression was higher in tissues presenting with Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation (p=0.0293).

CONCLUSION

We confirmed the contribution of PTPRZ1 and especially PTPRQ in CRC development, supporting the hypothesis that PTPRQ is a candidate oncogene, playing a crucial role in phosphorylation/dephosphorylation signaling pathways.