Multiple myloma represents the second most common blood cancer.Although new drugs emerge rapidly,multiple myeloma is still incurable.Drug resistance is one of the main causes of myeloma recurrence and relapse.In this paper,advances about the drug resistance mechanisms reported in the 55th ASH annual meeting are summarized.

Objective:To explore the role of cell division cycle protein 37 (Cdc37) mediating bortezomib (BTZ) resistance in multiple myeloma (MM) via the regulation of autophagy activity to provide a novel strategy for MM therapy.Methods:The expressions of Cdc37 and LC3b were investigated in BTZ-resistant MM cell line ANBL-6.BR using quantitative real-time PCR (qRT-PCR) and western blot (WB) analysis. Cdc37 was upregulated in ANBL-6.BR cells owing to lentivirus transfection. The LC3b expression was detected with WB, and BTZ-induced apoptosis was explored using flow cytometry. Cdc37 was then down-regulated by shRNA in the MM cell line NCI-H929. Sensitivity of BTZ was evaluated using CCK-8 analysis. WB analysis was performed to check the expression of the AKT/mTOR pathway and autophagy-associated proteins. The sensitivity of NCI-H929 cells to BTZ in the presence of autophagy inhibitor chloroquine (CQ) was analyzed using flow cytometry.Results:Cdc37 was down-regulated, while autophagy-associated gene LC3b was upregulated in BTZ-resistant cell line ANBL-6.BR. Up-regulated Cdc37 in ANBL-6.BR cells could inhibit LC3b expression and increase the sensitivity of MM to BTZ. Suppressing Cdc37 expression in MM cell line NCI-H929 induced BTZ resistance and autophagy activation, while CQ could rescue BTZ resistance caused by Cdc37 inhibition.Conclusion:Cdc37 may participate in BTZ resistance in MM via the regulation of autophagy activity.

OBJECTIVETo investigate the influence of renal function on the level of β₂-microglobulin (β₂-MG) as prognostic factor in newly diagnosed multiple myeloma (MM) patients, and to analyze the overall survival (OS) in different level of β₂-MG with relatively normal or abnormal renal function in MM patients.

METHODSAccording to the level of β₂-MG, 666 newly diagnosed MM patients were divided into three groups as β₂-MG<3.5, 3.5-<5.5, ≥5.5 mg/L. According to the level of serum creatinine, these patients were divided into two groups:serum creatinine <177 μmol/L as relatively normal group, serum creatinine ≥177 μmol/L as abnormal group.

RESULTSAmong 666 patients, there were 416 male and 250 female, the median age was 58 (25-86) years old. Comparison of OS among β₂-MG<3.5, 3.5-<5.5, ≥5.5 mg/L groups indicated that the median OS of the three groups were 85.75 (95% CI 70.99-100.50), 47.25 (95% CI 40.98-53.53) and 35.05 (95% CI 30.75-39.35) months, respectively (P<0.01). Comparison of OS between serum creatinine <177 and ≥177 mmol/L groups, the median OS of the two groups were 64.67 (95% CI 56.57-72.77) and 32.74 (95% CI 27.74-37.73) months, respectively (P<0.01). In β₂-MG≥5.5 mg/L, the median OS of relatively normal and abnormal groups were 37.25 (95% CI 31.45-43.06) and 32.55 (95% CI 26.26-38.83) months, respectively (P=0.142).

CONCLUSIONHigh level of β₂-MG and renal function correlated with shorter survival of MM patients. Higher level of β₂-MG with abnormal renal function can't change the prognostic value of β₂-microglobulin on MM.

Adult ; Aged ; Aged, 80 and over ; Female ; Humans ; Kidney ; Kidney Function Tests ; Male ; Middle Aged ; Multiple Myeloma ; Neoplasm Staging ; Prognosis ; beta 2-Microglobulin