High expression of VARS promotes the growth of multiple myeloma cells by causing imbalance in valine metabolism / 中南大学学报(医学版)

OBJECTIVES@#Multiple myeloma (MM) is a plasma cell malignancy occurring in middle and old age. MM is still an incurable disease due to its frequent recurrence and drug resistance. However, its pathogenesis is still unclear. Abnormal amino acid metabolism is one of the important characteristics of MM, and the important metabolic pathway of amino acids participates in protein synthesis as basic raw materials. Aminoacyl transfer ribonucleic acid synthetase (ARS) gene is a key regulatory gene in protein synthesis. This study aims to explore the molecular mechanism for ARS, a key factor of amino acid metabolism, in regulating amino acid metabolism in MM and affecting MM growth.@*METHODS@#The corresponding gene number was combined with the gene expression profile GSE5900 dataset and GSE2658 dataset in Gene Expression Omnibus (GEO) database to standardize the gene expression data of ARS. GSEA_4.2.0 software was used to analyze the difference of gene enrichment between healthy donors (HD) and MM patients in GEO database. GraphPad Prism 7 was used to draw heat maps and perform data analysis. Kaplan-Meier and Cox regression model were used to analyze the expression of ARS gene and the prognosis of MM patients, respectively. Bone marrow samples from 7 newly diagnosed MM patients were collected, CD138+ and CD138- cells were obtained by using CD138 antibody magnetic beads, and the expression of ARS in MM clinical samples was analyzed by real-time RT-PCR. Human B lymphocyte GM12878 cells and human MM cell lines ARP1, NCI-H929, OCI-MY5, U266, RPMI 8266, OPM-2, JJN-3, KMS11, MM1.s cells were selected as the study objects. The expression of ARS in MM cell lines was analyzed by real-time RT-PCR and Western blotting. Short hairpin RNA (shRNA) lentiviruses were used to construct gene knock-out plasmids (VARS-sh group). No-load plasmids (scramble group) and gene knock-out plasmids (VARS-sh group) were transfected into HEK 293T cells with for virus packaging, respectively. Stable expression cell lines were established by infecting ARP1 and OCI-MY5 cells, and the effects of knockout valyl-tRNA synthetase (VARS) gene on proliferation and apoptosis of MM cells were detected by cell counting and flow cytometry, respectively. GEO data were divided into a high expression group and a low expression group according to the expression of VARS. Bioinformatics analysis was performed to explore the downstream pathways affected by VARS. Gas chromatography time-of-flight mass spectrometry (GC-TOF/MS) and high performance liquid chromatography (HPLC) were used to detect the valine content in CD138+ cells and ARP1, OCI-MY5 cells and supernatant of knockdown VARS gene in bone marrow samples from patients, respectively.@*RESULTS@#Gene enrichment analysis showed that tRNA processing related genes were significantly enriched in MM compared with HD (P<0.0001). Further screening of tRNA processing-pathway related subsets revealed that cytoplasmic aminoacyl tRNA synthetase family genes were significantly enriched in MM (P<0.0001). The results of gene expression heat map showed that the ARS family genes except alanyl-tRNA synthetase (AARS), arginyl-tRNA synthetase (RARS), seryl-tRNA synthetase (SARS) in GEO data were highly expressed in MM (all P<0.01). With the development of monoclonal gammopathy of undetermined significance (MGUS) to MM, the gene expression level was increased gradually. Kaplan-Meier univariate analysis of survival results showed that there were significant differences in the prognosis of MM patients in methionyl-tRNA synthetase (MARS), asparaginyl-tRNA synthetase (NARS) and VARS between the high expression group and the low expression group (all P<0.05). Cox regression model multivariate analysis showed that the high expression of VARS was associated with abnormal overall survival time of MM (HR=1.83, 95% CI 1.10 to 3.06, P=0.021). The high expression of NARS (HR=0.90, 95% CI 0.34 to 2.38) and MARS (HR=1.59, 95% CI 0.73 to 3.50) had no effect on the overall survival time of MM patients (both P>0.05). Real-time RT-PCR and Western blotting showed that VARS, MARS and NARS were highly expressed in CD138+ MM cells and MM cell lines of clinical patients (all P<0.05). Cell counting and flow cytometry results showed that the proliferation of MM cells by knockout VARS was significantly inhibited (P<0.01), the proportion of apoptosis was significantly increased (P<0.05). Bioinformatics analysis showed that in addition to several pathways including the cell cycle regulated by VARS, the valine, leucine and isoleucine catabolic pathways were upregulated. Non-targeted metabolomics data showed reduced valine content in CD138+ tumor cells in MM patients compared to HD (P<0.05). HPLC results showed that compared with the scramble group, the intracellular and medium supernatant content of ARP1 cells and the medium supernatant of OCI-MY5 in the VARS-shRNA group was increased (all P<0.05).@*CONCLUSIONS@#MM patients with abnormal high expression of VARS have a poor prognosis. VARS promotes the malignant growth of MM cells by affecting the regulation of valine metabolism.

Diagnosis and treatment of multiple myeloma in Hunan Province / 中南大学学报(医学版)

OBJECTIVES@#There is less clinical data on multiple myeloma (MM) in China, and the aim of this study was to collect and analyze the clinical data of newly diagnosed multiple myeloma (NDMM) patients in Hunan Province during 1 year, to understand the real clinical features and treatment outcome for Hunan Province patients with MM, and to strengthen the understanding of the standardized diagnosis process and treatment plan of MM.@*METHODS@#The clinical data of 529 patients with NDMM in 12 large-scale general hospitals in Hunan Province from January 1 to December 31, 2019 were collected and analyzed, including baseline data, treatment regimens, duration of treatment, and adverse reactions. The clinical characteristics, treatment, and safety of patients were analyzed by SPSS 21.0.@*RESULTS@#Among the 529 NDMM patients, the age was 33-90 (median 64) years and the male-female ratio was 1.38꞉1. The clinical features ranged from high to low were as follows: Bone pain (77.7%), anemia (66.8%), renal insufficiency (40.6%), hypercalcemia (15.1%). Typing: IgG 46.5%, IgA 24.6%, IgD 2.6%, IgM 0.8%, light chain 15.7%, double clone 3.0%, no secretion 0.6%, absence 6.2%. Staging: Durie-Salmon stage I, II, and III were 4.5%, 10.6%, 77.3%, respectively, and 40 cases (7.6%) missed this data. International Staging System (ISS) stage I, II, and III were 10.4%, 24.4%, and 47.6%, respectively, and 93 cases (17.6%) were missing. Revised International Staging System (R-ISS) stage I, II, and III were 5.5%, 27.0%, 23.1%, respectively, and 235 cases (44.4%) missed this data. Among the 98 NDMM patients in the Third Xiangya Hospital, Central South University, Durie-Salmon (DS) stage missing 2.0%, ISS stage missing 12.3%, and R-ISS stage missing 12.3%.Treatment: Among the 529 patients,475 received treatment, the rate of treatment was 89.8%; 67.4% of the patients were able to complete four courses of chemotherapy at induction phase, 90.3% of the patients received proteasome inhibitor based combination chemotherapy regimen more than once, 67.2% received immunomodulator based regimen more than once, and 59.8% of the patients received proteasome inhibitor and immunomodulator based combination chemotherapy regimen more than once. Curative: Overall response rate (ORR) and high quality response rate (HQR) of the 4-course group were better than those of the 2-course group (ORR: 85% vs 65%, P=0.006; HQR: 68.3% vs 24.0%, P<0.001). The HQR of the standard chemotherapy group was better than that of the non-standard chemotherapy group (65.1% vs 48.2%, P=0.035). Adverse reactions during treatment included hematologic toxicity (17.5%), peripheral neuropathy (24.8%), gastrointestinal adverse events (23.8%), pulmonary infection (25.9%), herpes zoster (4.6%), and venous thrombotic events (1.7%).@*CONCLUSIONS@#In 2019, the missed diagnosis rate of MM patients was high, the medium age of diagnosis was older, and the accuracy of patient diagnosis was not high. There is a great difference among medical centers, especially in the stage and risk stratified, nearly half of NDMM patients are not diagnosed with R-ISS stage; the lack of cytogenetic data needs to be supplemented by follow-up studies. A high proportion of patients with NDMM present with bone pain and anemia.Patients received treatment have higher use of chemotherapy regimens containing proteasome inhibitors and/or immunomodulators, but there is a significant gap among different medical centers, and standardized treatment needs to be strengthened. The safety during chemotherapy is controllable.

Curative effect of low dose cytarabine and aclarubin in combination with granulocyte colony-stimulating factor priming (CAG regimen) on patients with the intermediate and high-risk myelodysplastic syndrome / 中南大学学报(医学版)

OBJECTIVE@#To evaluate the curative effect and adverse effect of low dose cytarabine and aclarubin in combination with granulocyte colony-stimulating factor priming (CAG regimen) on patients with the intermediate and high-risk myelodysplastic syndrome.@*METHODS@#A: total of 46 patients with intermediate and high-risk myelodysplastic syndrome was retrospectively analyzed. Twenty-eight patients received CAG regimen and 18 received conventional chemotherapy. CAG regimen: aclarubicin 10 mg/(m2.d)intravenously daily, Day 1~8; cytarabine 10 mg/ m2 subcutaneously once every 12 hours, Day 1~14; and subcutaneously use of granulocyte colony-stimulating factor 200 mug/(m2.d) until 12 hours before the last use of cytarabine. The initial outcome was evaluated after the first course of treatment. The responders received the second course. The ultimate therapeutic effect was evaluated after the 2 courses.@*RESULTS@#The overall response rate in the CAG regimen group was 78.6% (22/28). Thirteen patients (46.4%) responded, 5 (17.9%) showed partial response, and 4 (14.3%) hematologic improvement. The overall response rate in the conventional chemotherapy group was 50%(9/18). Six patients (33.3%) achieved complete response, 2 (11.1%) partial response, and 1(5.6%) hematologic improvement. The overall response rate of the CAG group was significantly higher than that in the control group (P<0.05). The adverse effects of CAG regimen were bearable.@*CONCLUSION@#With acceptable adverse effect, CAG regimen is effective for the intermediate and high-risk myelodysplastic syndrome. Long-time outcome needs further observation.

Effect of Velcade combined with Dexamethasone on multiple myeloma / 中南大学学报(医学版)

OBJECTIVE@#To compare the effect and safety between Velcade-Dexamethasone (VD)and revised Vinorebine+Pirarubicin+ Dexamethasone (VAD) regiment for multiple myeloma (MM).@*METHODS@#Thirty-six patients with MM were reviewed, 16 of whom were treated with VD (VD Group) and the others with VAD. European Group for Blood and Marrow Transplant (EBMT) criteria and National Cancer Institute Common Terminology Criteria for Adverse Events (NCICTCAE) were chosen to analyze the efficacy and side effects.@*RESULTS@#In the VD group and the revised VAD group, the rates of complete response, partial response, minimal response, no change and progress disease were 50% vs. 5%, 25% vs. 25%, 18.8% vs. 15%, 6.2% vs. 35% and 0 vs. 20%, respectively. The total response rates were 93.8% vs 45%. There was significant difference in the overall response rate between the 2 groups (P<0.05). The side effects were less serious, and the endurance was better in the VD group than those in the revised VAD group. No serious effects of hematology and cardiology were seen, and good endurance was showed in the renal dysfunction in the VD group.@*CONCLUSION@#Velcade combined with dexamethasone is a safe and effective regiment for multiple myeloma with good safety and endurance.