Lactate Decreases Bortezomib Sensitivity and Predicts Poor Clinical Outcomes of Multiple Myeloma

Objective:Metabolic disorders are regarded as hallmarks of multiple myeloma(MM)and are responsible for rapid cancer cell proliferation and tumor growth.However,the exact biological roles of metabolites in MM cells have not been fully explored.This study aimed to explore the feasibility and clinical significance of lactate for MM and investigate the molecular mechanism of lactic acid(Lac)in the proliferation of myeloma cells and cell sensitivity to bortezomib(BTZ).Methods:Metabolomic analysis of the serum was carried out to obtain metabolites expression and clinical characteristics in MM patients.The CCK8 assay and flow cytometry were used to detect cell proliferation,apoptosis,and cell cycle changes.Western blotting was used to detect the potential mechanism and apoptosis-and cycle-related protein changes.Results:Lactate was highly expressed in both the peripheral blood and bone marrow of MM patients.It was significantly correlated with Durie-Salmon Staging(DS Staging)and the International Staging System(ISS Staging)and the serum and urinary involved/uninvolved free light chain ratios.Patients with relatively high lactate levels had a poor treatment response.Moreover,in vitro experiments showed that Lac could promote the proliferation of tumor cells and decrease the proportion of G0/G1-phase cells,which was accompanied by an increased proportion of S-phase cells.In addition,Lac could decrease tumor sensitivity to BTZ by disrupting the expression of nuclear factor kappa B subunit 2(NFκB2)and Re1B.Conclusion:Metabolic changes are important in MM cell proliferation and treatment response;lactate could be used as a biomarker in MM and as a therapeutic target to overcome cell resistance to BTZ.

Long noncoding RNA 1392 regulates MDA5 by interaction with ELAVL1 to inhibit coxsackievirus B5 infection

Long noncoding RNAs(lncRNAs)modulate many aspects of biological and pathological processes.Recent studies have shown that host lncRNAs participate in the antiviral immune response,but functional lncRNAs in coxsackievirus B5(CVB5)infection remain unknown.Here,we identified a novel cytoplasmic lncRNA,LINC1392,which was highly inducible in CVB5 infected RD cells in a time-and dose-dependent manner,and also can be induced by the viral RNA and IFN-β.Further investigation showed that LINC1392 promoted several important interferon-stimulated genes(ISGs)expression,including IFIT1,IFIT2,and IFITM3 by activating MDA5,thereby inhibiting the replication of CVB5 in vitro.Mechanistically,LINC1392 bound to ELAV like RNA binding protein 1(ELAVL1)and blocked ELAVL1 interaction with MDA5.Functional study revealed that the 245–835 nt locus of LINC1392 exerted the antiviral effect and was also an important site for ELAVL1 binding.In mice,LINC1392 could inhibit CVB5 replication and alleviated the histopathological lesions of intestinal and brain tissues induced by viral infection.Our findings collectively reveal that the novel LINC1392 acts as a positive regulator in the IFN-I signaling pathway against CVB5 infection.Elucidating the underlying mechanisms on how lncRNA regulats the host innate immunity response towards CVB5 infection will lay the foundation for antiviral drug research.