ABSTRACT
<p><b>OBJECTIVE</b>To investigate the diagnostic value of circulating serum miRNA for multiple myeloma.</p><p><b>METHODS</b>Forty blood samples from patients with multiple myeloma were collected from July 2013 to June 2014 in Department of Hematology, Zhongshan Hospital Affiliated to Xiamen University. The real-time quantitative PCR was performed to detect the serum expression levels of miRNAs (miR-29a, miR-155, miR-16 and miR-92a) circulating in the different stages of patients with multiple myeloma and evaluate the diagnostic value for patients with multiple myeloma.</p><p><b>RESULTS</b>The serum level of miR-29a significantly increased in newly diagnosed patients as compared to healthy donor (P<0.01), serum miR-155 levels were significantly lower as compared with healthy donor(P<0.001); The ratio of miR-29a and miR-155 was an effective biomarker for distinguishing multiple myeloma from healthy donor, their sensitivity and specificity were 80.8% and 83.3% respectively for myeloma diagnosis. the change of miR-29a expression was consistent with the changes of bone marrow plasma cells and M protein levels.</p><p><b>CONCLUSION</b>These circulating serum microRNA, such as miR-29a, miR-155 and miR-16, may serve as potential diagnostic biomarkers for multiple myeloma, and the ratio of miR-29a/miR-155 may serve as a most useful biomarker for myeloma diagnosis.</p>
ABSTRACT
This study was aimed to investigate the molecular mechanism of doxorubicin resistance in multiple myeloma cell line and certify the effect of Notch signal over-expression on drug resistance of myeloma cells. The doxorubicin RPMI 8226 cell line (RPMI8226/DOX) was established by culturing 8226 cells with continuous low concentration and intermittent gradually-increasing-concentration of doxorubicin in vitro, the mRNA expression of Notch2,Jagged1, Jagged2, HES1 were measured by RT-PCR and the P-170 protein expression was detected by Western blot in RPMI 8226 cell line; the changes of IL-6 and VEGF were tested by ELISA. The results showed that the Notch mRNA expression (Notch2, Jagged1, Jagged2 increased gradually along with the increase of chemotherapeutic drug resistance, but the expression of HESI mRNA gradually decreased along with the increase of drug resistance. The expression level of P-170 protein was upregulated gradually along with the increase of drug resistance. The level of VEGF and IL-6 in culture supernatants of RPMI8226/DOX was higher than that in RPMI 8226. It is concluded that the establishment of RPMI 8226/DOX cell line is a useful model to analyze the mechanism of chemotherapeutic drug resistance in multiple myeloma, Notch activation is closely correlated with the drug resistance of multiple myeloma and Notch signaling may to be used as a new target for multiple myeloma treatment.