Expression Of DJ-1 Gene In Multiple Myeloma Cells And Its Clinical Relevance

Objective: In this study,we aimed to explore the expression of DJ-1gene in CD138+ cells of newly diagnosed multiple myeloma(MM)patients and its clinical relevance.Method: Mononucleated cells were isolated from bone marrow of newly diagnosed MM patients(BM-MNCs)and peripheral blood of healthy donors(HD)(PB-MNCs)by using density-gradient centrifugation.Next,CD138+myeloma cells were further separated with magnetic-activated cell sorting(MACS)and the purity was measured with flow cytometry.The expression of DJ-1 mRNA in CD138+ myeloma cells and HD PB-MNCs was detected by using quantitative reverse transcription PCR(RT-qPCR).The expression of DJ-1 protein was also detected by Western blot.Finally,the clinical relevance of DJ-1 mRNA was analyzed,including disease subtypes,baseline international scoring system(ISS)stages,lactate dehydrogenase(LDH)levels.Meanwhile,patients were followed up and their response to treatment was evaluated,and the correlation between baseline DJ-1 mRNA expression and response was analyzed.Result: 1.A total of 28 newly diagnosed MM bone marrow samples were collected,of which 23 cases of CD138+ myeloma cells were successfully separated and available for further study.2.The relative expression level of DJ-1 mRNA in CD138+ mylema cells was 0.197(0.117-0.408)(2-?CT,n=23),and the relative expression level of DJ-1 mRNA in HD PB-MNCs was 0.019(0.017-0.021)(2-?CT,n=23),and thedifference was statistically significant(P<0.001),which was also verified by DJ-1 protein detection.3.The relative expression levels of DJ-1 mRNA in CD138+ myeloma cells in male and female MM patients were 0.232(0.095-0.511)(2-?CT,n=16)and 0.197(0.133-0.307)(2-?CT,n=7),respectively,and the difference was not statistically significant(P=0.764);MM patients ? 65 and <65 years old had DJ-1 mRNA levels of no statistical difference(P=0.336),and the relative expression levels of DJ-1 mRNA were 0.285(0.164-0.408)(2-?CT,n=10)and 0.168(0.112-0.307)(2-?CT,n=13)respectively.4.The relative expression levels of DJ-1 mRNA in CD138+ myeloma cells in patients with IgG and IgA MM were 0.178(0.133-0.510)(2-?CT,n=10)and 0.273(0.095-0.408)(2-?CT,n=9),and the difference was not statistically significant(P = 0.806).Similarly,the relative expression of DJ-1 mRNA in ? and ? type MM was 0.249(0.112-0.558)(2-?CT,n=12)and0.192(0.117-0.307)(2-?CT,n=11),and there was no significant difference(P= 0.460).5.For MM patients with ISS I + II disease,the relative expression level of DJ-1 mRNA was 0.273(0.164-0.343)(2-?CT,n=12),and for those with ISS III disease,was 0.192(0.117-0.307)(2-?CT,n=10).6.MM patients with ISS I + II(n=10)disease had a LDH level of 138.1(124.8-197)U/L,and patients with ISS III(n=7)disease had 171.8(126-214.5)U/L,and the correlation coefficient between DJ-1mRNA(2-?CT)and LDH was 0.458,(n=17).7.The baseline DJ-1 mRNA were 0.51(0.117-0.558)(2-?CT,n=5)in patients with partial remission and above(?PR)and 0.273(0.112-0.307)(2-?CT,n=7)in those with less than PR,after 2 cycles of chemotherapy.Conclusion:1.The expression level of DJ-1 in CD138+ cells of MM patients was aberrantly increased.2.The expression level of DJ-1 mRNA in CD138+ myeloma cells was not relevant to the gender(male or female)or age(? 65 or <65)of MM patients.3.The correlation of DJ-1mRNA expression with and disease stage,LDH and response to therapy was not determined,due to the limited number of samples and duration of follow-up in this studywhich warranted a further study.