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 (NFkB2) and RelB. 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.

Reverse effect of Semaphorin-3F on rituximab resistance in diffuse large B-cell lymphoma via the Hippo pathway.

BACKGROUND: Exploring the underlying mechanism of rituximab resistance is critical to improve the outcomes of patients with diffuse large B-cell lymphoma (DLBCL). Here, we tried to identify the effects of the axon guidance factor semaphorin-3F (SEMA3F) on rituximab resistance as well as its therapeutic value in DLBCL. METHODS: The effects of SEMA3F on the treatment response to rituximab were investigated by gain- or loss-of-function experiments. The role of the Hippo pathway in SEMA3F-mediated activity was explored. A xenograft mouse model generated by SEMA3F knockdown in cells was used to evaluate rituximab sensitivity and combined therapeutic effects. The prognostic value of SEMA3F and TAZ (WW domain-containing transcription regulator protein 1) was examined in the Gene Expression Omnibus (GEO) database and human DLBCL specimens. RESULTS: We found that loss of SEMA3F was related to a poor prognosis in patients who received rituximab-based immunochemotherapy instead of chemotherapy regimen. Knockdown of SEMA3F significantly repressed the expression of CD20 and reduced the proapoptotic activity and complement-dependent cytotoxicity (CDC) activity induced by rituximab. We further demonstrated that the Hippo pathway was involved in the SEMA3F-mediated regulation of CD20. Knockdown of SEMA3F expression induced the nuclear accumulation of TAZ and inhibited CD20 transcriptional levels via direct binding of the transcription factor TEAD2 and the CD20 promoter. Moreover, in patients with DLBCL, SEMA3F expression was negatively correlated with TAZ, and patients with SEMA3F low TAZ high had a limited benefit from a rituximab-based strategy. Specifically, treatment of DLBCL cells with rituximab and a YAP/TAZ inhibitor showed promising therapeutic effects in vitro and in vivo . CONCLUSION: Our study thus defined a previously unknown mechanism of SEMA3F-mediated rituximab resistance through TAZ activation in DLBCL and identified potential therapeutic targets in patients.

The Novel Prognostic Index Model of Combining Circulating Tumor DNA and PINK-E Predicts the Clinical Outcomes for Newly Diagnosed Extranodal NK/T-cell Lymphoma.

Extranodal NK/T-cell lymphoma (ENKTL) is a highly aggressive and heterogeneous disease with poor clinical outcome. Our previous work had demonstrated that circulating tumor DNA (ctDNA) analyses were feasible in ENKTL, and dynamic tracing of ctDNA could be used to monitor the disease status. However, the prognostic value of ctDNA in ENKTL has not been fully investigated. Patients with newly diagnosed ENKTL from February 2017 to December 2021 (n = 70) were enrolled. The pretreatment ctDNA concentration (hGE/mL) was measured. The prognostic value of ctDNA, international prognostic index (IPI), Korean prognostic index (KPI), PINK-E, and the combination of PINK-E and ctDNA (PINK-EC) were investigated in our cohort. The IPI and PINK-E risk categories had a significant difference in progression-free survival (PFS) and overall survival (OS) between the low-risk and intermediate-risk groups. The KPI risk category had a difference in PFS and OS between the intermediate-risk and high-risk groups. Furthermore, integrating ctDNA into the PINK-E model could overcome the shortcomings of other prognostic models, which could significantly distinguish the different-risk groups. Overall, our results demonstrated that PINK-EC showed a superior prognostic prediction value and stability compared with IPI, KPI, and PINK-E. The integration of molecular features of the tumor into classic risk categories might better characterize a high-risk group where novel treatment approaches are most needed.