ROR1, a transmembrane tyrosine kinase receptor is intensively expressed by cells during embryonic development, but it is not detected in adult tissues. An increased expression of the ROR1 protein was found in patients with malignant tumors, and especially important prognostic and diagnostic values were demonstrated for patients with CLL (chronic lymphocytic leukemia). However, studies of the expression of ROR1 mRNA are single, and the use of RT-PCR technology, available in most laboratories, could significantly increase the application of this study in clinical practice.

THE AIM

Of the work was to study the level of ROR1 mRNA expression in blood leukocytes in patients with CLL.

MATERIAL AND METHODS

In the study venous blood samples from 37 patients with the first diagnosed B-cell CLL, before and during the course of therapy were used, as also 10 samples from patients with CML, 6 patients with B-cell small lymphocytic lymphoma, 11 patients with multiple myeloma and 21 health donors made up the control group. RNA was isolated from blood leukocytes using the Ribosol D reagent kit, reverse transcription was performed using the Reverta-L reagent kit. The level of ROR1 mRNA expression was determined by RT-PCR using original primers and a TaqMan probe developed in our laboratory.

RESULTS

ROR1 mRNA expression was observed in the blood samples of 23 CLL patients and it did not depend on the number of blood cells and the stage of the disease, while ROR1 expression was not detected in the samples of patients of all other groups or healthy donors. During therapy, ROR1 expression decreased in all 11 patients examined.

CONCLUSIONS

The developed method allows to determine the expression of ROR1 mRNA, which has promising diagnostic and prognostic value for patients with CLL.