Apoptosis In Diffuse Large B-cell Lymphoma Cells Research Articles

Michael Acceptor Pyrrolidone Derivatives and Their Activity against Diffuse Large B-cell Lymphoma.

This study aimed to design and evaluate the efficacy of pyrrolidone derivatives as potential therapeutic agents against diffuse large B-cell lymphoma (DLBCL), a common and heterogeneous malignancy of the adult lymphohematopoietic system. Given the limitations of current therapies, there is a pressing need to develop new and effective drugs for DLBCL treatment. A series of pyrrolidone derivatives were synthesized, and their antitumor activities were assessed, particularly against DLBCL cell lines. Structure-activity relationship (SAR) analysis was conducted to identify key structural components essential for activity. The most promising compound, referred to as compound 7, was selected for further mechanistic studies. The expression levels of relevant mRNA and protein were detected by RT-qPCR and Western blotting, and the expression of mitochondrial membrane potential and ROS was detected using flow cytometry for further assessment of cell cycle arrest and apoptosis. The compound 7 exhibited good antitumor activity among the synthesized derivatives, specifically in DLBCL cell lines. SAR analysis highlighted the critical role of α, β-unsaturated ketones in the antitumor efficacy of these compounds. Mechanistically, compound 7 was found to induce significant DNA damage, trigger an inflammatory response, cause mitochondrial dysfunction, and disrupt cell cycle progression, ultimately leading to apoptosis of DLBCL cells. The compound 7 has good antitumor activity and can induce multiple cellular mechanisms leading to cancer cell death. These findings warrant further investigation of the compound 7 as a potential therapeutic agent for DLBCL.

Ouabain-mediated downregulation of ALKBH5 and IGF2BP2 inhibits the malignant progression of DLBCL.

m6A modification is a crucial epigenetic regulatory mechanism in diffuse large B-cell lymphoma (DLBCL). Low-dose cardiotonic drugs have been shown to induce apoptosis in DLBCL cells through epigenetic modulation. However, the involvement of the cardiotonic drug ouabain in the malignant progression of DLBCL remains unclear. Our study revealed that ouabain indeed contributes to the malignant progression of DLBCL through m6A modification. Through qPCR analysis, we observed a negative correlation between ouabain concentration and the expression levels of the demethylase ALKBH5 and the m6A-binding protein IGF2BP2 in DLBCL cells. Furthermore, high expression levels of ALKBH5 and IGF2BP2 were identified in both the GEO database and DLBCL patient tissue samples. Notably, elevated ALKBH5 and IGF2BP2 promoted cell proliferation both in vitro and in vivo. Inhibition of their expression rendered DLBCL cells more sensitive to ouabain treatment, resulting in significant suppression of cell proliferation, G1/S phase cell cycle arrest, and increased apoptosis. In summary, our results clarify that the demethylase ALKBH5 and the m6A-binding protein IGF2BP2 are involved in the malignant progression of DLBCL, and that the cardiotonic drug ouabain can inhibit the proliferation of DLBCL cells by inhibiting the expression of ALKBH5 and IGF2BP2, which provides new insights into the targeted treatment of DLBCL.

Transcriptional activation of SIRT5 by FOXA1 reprograms glycolysis to facilitate the malignant progression of diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common diagnosed subtype of lymphoma with high invasiveness and heterogeneity. Glycolysis is involved in regulating DLBCL progression. We aimed to explore the role of forkhead box protein A1 (FOXA1) in DLBCL and the mechanisms related to sirtuine5 (SIRT5) and glycolysis. FOXA1 expression in DLBCL cells was analyzed. Then, the proliferation and apoptosis of DLBCL cells were detected using Cell Counting Kit-8 (CCK-8), 5-ethynyl-2′-deoxyuridine (EDU) staining and flow cytometry analysis following FOXA1 or SIRT5 knockdown. The glycolysis was assessed by measuring extracellular acidification rate (ECAR), glucose consumption and lactate secretion. Immunoblotting was employed to examine the expression of apoptosis- and glycolysis-related proteins. Additionally, luciferase reporter assay and chromatin immunoprecipitation (ChIP) assay were conducted to test the combination of FOXA1 to SIRT5 promotor region. Subsequently, SIRT5 expression was upregulated to conduct rescue assays. Finally, the effects of FOXA1 downregulation on the growth and glycolysis in OCI-ly7 tumor-bearing mice were examined. As a result, FOXA1 was upregulated in DLBCL cells and FOXA1 or SIRT5 knockdown inhibited the proliferation, accelerated the apoptosis and suppressed glycolysis reprograming in DLBCL cells. Importantly, FOXA1 could transcriptionally activate SIRT5 expression in DLBCL cells. Besides, SIRT5 overexpression counteracted the effects of FOXA1 deficiency on the proliferation, apoptosis and glycolysis reprogramming in DLBCL cells. Furthermore, FOXA1 knockdown inhibited the tumor growth, suppressed the glycolysis reprogramming and downregulated SIRT5 expression in vivo. In summary, FOXA1 could transcriptionally activate SIRT5 to reprogram glycolysis, thereby facilitating the malignant progression of DLBCL.

Low NDRG2, regulated by the MYC/MIZ-1 complex and methylation, predicts poor outcomes in DLBCL patients.

Diffuse large B-cell lymphoma (DLBCL) represents the most common tumor in non-Hodgkin's lymphoma. N-Myc downstream-regulated gene 2 (NDRG2) is a tumor suppressor highly expressed in healthy tissues but downregulated in many cancers. Although cell proliferation-related metabolism rewiring has been well characterized, less is known about the mechanism of metabolic changes with DLBCL. Herein, we investigated the expressions of NDRG2, MYC and Myc-interacting zinc finger protein 1 (MIZ-1) in seven human lymphoma (mostly DLBCLs) cell lines. NDRG2 expression was inversely correlated with the expressions of MYC and MIZ-1. Further, we explored the regulatory mechanism and biological functions underlying the lymphomagenesis involving NDRG2, MYC and MIZ-1. MYC and MIZ-1 promoted DLBCL cell proliferation, while NDRG2 induced apoptosis in LY8 cells. Moreover, NDRG2 methylation was reversed by the 5-Aza-2'-deoxycytidine (5-Aza-CDR) treatment, triggering the downregulation of MYC and inhibiting DLBCL cell survival. MYC interacts with NDRG2 to regulate energy metabolism associated with mTOR. Remarkably, supporting the biological significance, the converse correlation between NDRG2 and MYC was observed in human DLBCL tumor tissues (R = -0.557). Bioinformatics analysis further validated the association among NDRG2, MYC, MIZ-1, mTOR, and related metabolism genes. Additionally, NDRG2 (P = 0.001) and MYC (P < 0.001) were identified as promising prognostic biomarkers in DLBCL patients through survival analysis. Together, our data demonstrate that the MYC/MIZ-1 complex interplays with NDRG2 to influence the proliferation and apoptosis of DLBCL cells and show the characterizations of NDRG2, MYC and MIZ-1 for metabolism features and prediction prognosis in DLBCL.

β-Sitosterol Inhibits Tumor Growth and Amplifies Rituximab Sensitivity through Acid Sphingomyelinase/Ceramide Signaling in Diffuse Large B-Cell Lymphoma.

Rituximab (RTX) resistance is a notable challenge in treating diffuse large B-cell lymphoma (DLBCL). β-Sitosterol (β-ST) is a plant sterol that has been found in a broad variety of fruits, spices, and medicinal plants. The antineoplastic properties of β-ST are established in various solid malignancies; however, its effect on DLBCL is uncharted. This study investigates the role of β-ST in DLBCL as well as the underlying mechanisms. Our findings indicated that β-ST impeded DLBCL cell proliferation in a concentration- and time-dependent manner. β-ST appeared to alter sphingolipid metabolism, facilitate acid sphingomyelinase (ASM) translocation to the plasma membrane, augment ceramide platforms through increased ceramide synthesis, and consequently induce apoptosis in DLBCL cells. Furthermore, we found that RTX initiated both apoptotic and survival pathways in vitro, with the former contingent on the transient activation of the ASM, and β-ST could amplify the anti-DLBCL efficacy of RTX by modulating ASM/Ceramide (Cer) signaling. Collectively, our findings elucidate the mechanistic role of β-ST in DLBCL and underscore its potential in amplifying the antineoplastic efficacy of RTX via ASM activation, proposing a potential avenue to improve the efficacy of RTX therapy.

Aurkin-A, a TPX2-Aurora A small molecule inhibitor disrupts Alisertib-induced polyploidy in aggressive diffuse large B cell lymphoma

Chemotherapy induced polyploidy is a mechanism of inherited drug resistance resulting in an aggressive disease course in cancer patients. Alisertib, an Aurora Kinase A (AK-A) ATP site inhibitor, induces cell cycle disruption resulting in polyaneuploidy in Diffuse Large B Cell Lymphoma (DLBCL). Propidium iodide flow cytometry was utilized to quantify alisertib induced polyploidy in U2932 and VAL cell lines. In U2932 cells, 1µM alisertib generated 8n+ polyploidy in 48% of the total cell population after 5 days of treatment. Combination of Aurkin A an AK-A/TPX2 site inhibitor, plus alisertib disrupted alisertib induced polyploidy in a dose-dependent manner with associated increased apoptosis. We generated a stable FUCCI U2932 cell line expressing Geminin-clover (S/G2/M) and cdt1-mKO (G1), to monitor cell cycle progression. Using this system, we identified alisertib induces polyploidy through endomitosis, which was eliminated with Aurkin A treatment. In a VAL mouse xenograft model, we show polyploidy generation in alisertib treated mice versus vehicle control or Aurkin A. Aurkin A plus alisertib significantly reduced polyploidy to vehicle control levels. Our in vitro and in vivo studies show that Aurkin A synergizes with alisertib and significantly decreases the alisertib dose needed to disrupt polyploidy while increasing apoptosis in DLBCL cells.

FOXO3 suppresses lymphoma progression through promoting miR-34b/HSPG2 axis.

Diffuse large B-cell lymphoma (DLBCL) is the most common type of lymphoma, which caused many patients to lose their precious lives. FOXO3 was a suppressor in various cancers, however, the role and mechanism of FOXO3 in DLBCL remain unclear. Bioinformatics analysis was used to offer information FOXO3 expression and its expression for prognosis of DLBCL patients. The abundance of genes and proteins was evaluated using RT-qPCR and western blot. Cell proliferation and apoptosis was detected by CCK-8 and flow cytometry. The interactions among FOXO3, miR-34b, and HSPG2 were predicted by TransmiR and Starbase and validated using dual luciferase reporter assay, ChIP assay, and RIP assay. Our findings revealed that FOXO3 expression was abnormally declined in DLBCL cells. FOXO3 upregulation restrained cell proliferation and promoted cell apoptosis of DLBCL cells, while miR-34b inhibitor eliminated these influences. Similarly, miR-34b mimic suppressed malignant behaviors of DLBCL cells, which were abolished by HSPG2 overexpression. Mechanically, FOXO3 induced miR-34b expression through interacting with miR-34b promoter and HSPG2 was a targeted gene of miR-34b. FOXO3 attenuated the capability of cell proliferation and promoted cell apoptosis rate of DLBCL cells through affecting miR-34b/HSPG2 axis, therefore inhibiting DLBCL progression.

MYC-dependent MiR-7-5p regulated apoptosis and autophagy in diffuse large B cell lymphoma by targeting AMBRA1.

Diffuse large B-cell lymphoma (DLBCL) is the leading cause of mortality from invasive hematological malignancies worldwide. MicroRNA-7-5p (miR-7-5p) has been shown to be a tumor suppressor in several types of tumors. However, its role in DLBCL is not fully understood. This study explored the role of miR-7-5p in the progression of DLBCL and pursued the underlying mechanism. Quantitative real-time PCR and transfection of miRNA mimic and inhibitors were used to assess the effects of miR-7-5p on autophagy and apoptosis in SU-DHL-4 and SU-DHL-10 cells. Dual-luciferase reporter assay was used to identify target genes of miR-7-5p. Immunofluorescence, flow cytometry, and western blotting (WB) were performed to explore the underlying mechanism and downstream pathways of miR-7-5p and AMBRA1 in DLBCL cells. MiR-7-5p was upregulated in DLBCL cells. Luciferase reporter assays implicated AMBRA1 as a downstream target of miR-7-5p in DLBCL. WB and flow cytometry showed that an increase in miR-7-5p level and a decrease in AMBRA1 expression led to a decrease in autophagy and apoptosis-related protein expression. Furthermore, miR-7-5p prevented c-MYC dephosphorylation through AMBRA1 downregulation. On the contrary, c-MYC increased the expression of miR-7-5p, thereby establishing positive feedback on miR-7-5p transcription. The addition of hydroxychloroquine, an autophagy inhibitor, reduced autophagy and increased apoptosis in DLBCL cells. In vivo experiments further proved that the increase of miR-7-5p played a regulatory role in the expression of downstream AMBRA1 and c-MYC. These results demonstrate that c-MYC-dependent MiR-7-5p suppressed autophagy and apoptosis by targeting AMBRA1 in DLBCL cells. MiR-7-5p also suppressed autophagy and apoptosis by targeting AMBRA1 in DLBCL cells. Therefore, these data suggest that targeting miR-7-5p may be a promising strategy in DLBCL therapy.

M6A-related lncRNAs as potential biomarkers and the lncRNA ELFN1-AS1/miR-182-5p/BCL-2 regulatory axis in diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoid subtype. However, unsatisfactory survival outcomes remain a major challenge, and the underlying mechanisms are poorly understood. N6-methyladenosine (m6A), the most common internal modification of eukaryotic mRNA, participates in cancer pathogenesis. In this study, m6A-associated long non-coding RNAs (lncRNA) were retrieved from publicly available databases. Univariate, LASSO, and multivariate Cox regression analyses were performed to establish an m6A-associated lncRNA model specific to DLBCL. Kaplan-Meier curves, principal component analysis, functional enrichment analyses and nomographs were used to study the risk model. The underlying clinicopathological characteristics and drug sensitivity predictions against the model were identified. Risk modelling based on the three m6A-associated lncRNAs was an independent prognostic factor. By regrouping patients using our model-based method, we could differentiate patients more accurately for their response to immunotherapy. In addition, prospective compounds that can target DLBCL subtypes have been identified. The m6A-associated lncRNA risk-scoring model developed herein holds implications for DLBCL prognosis and clinical response prediction to immunotherapy. In addition, we used bioinformatic tools to identify and verify the ceRNA of the m6A-associated lncRNA ELFN1-AS1/miR-182-5p/BCL-2 regulatory axis. ELFN1-AS1 was highly expressed in DLBCL and DLBCL cell lines. ELFN1-AS1 inhibition significantly reduced the proliferation of DLBCL cells and promoted apoptosis. ABT-263 inhibits proliferation and promotes apoptosis in DLBCL cells. Invitro and invivo studies have shown that ABT-263 combined with si-ELFN1-AS1 can inhibit DLBCL progression.

Cinobufagin Induces Apoptosis of DLBCL Cells By Targeting the Inhibition of G6PD Activity

Background:Globally, there are 150,000 new cases of diffuse large B-cell lymphoma (DLBCL) each year, accounting for approximately 30% of all non-Hodgkin lymphoma cases. Although most patients can be cured with R-CHOP immunochemotherapy, 30-40% of patients progress or relapse after treatment. Therefore, there is an urgent need to find new treatments to improve the survival rate of this group of patients. Natural small molecule drugs have unique advantages as anticancer agents due to their low toxicity and multiple targets. This project aims to explore potentially effective natural compounds as new therapeutic strategies for DLBCL. Methods:Search for suitable natural compounds through GEO database, CMAP server and bioinformatics analysis. The effects of natural compounds on the biological function of DLBCL cells were studied by IC50 assay, apoptosis assay, cell cycle assay and subcutaneous transplanted tumor model. RNA sequencing, metabolomics detection, SEA server and 3D molecular simulation docking analysis were used to explore the drug target. The drug mechanism was verified by G6PD activity assay, EdU incorporation assay, NADPH assay and ROS assay. Results:We used GEO and CMAP databases to identify 20 natural compounds that target DLBCL prognostic genes. Cinobufagin, a natural bufodienol isolated from toad venom, became the main object of this study because of its low IC50 value. Flow cytometry analysis showed that cinobufagin can effectively induce G2 arrest and apoptosis of DLBCL cells. In addition, cinobufagin significantly inhibited the growth of tumor tissue in a mouse model of heterotopic subcutaneous tumor transplantation. The results of transcriptome sequencing suggested that cinobufagin treatment inhibited multiple metabolism-related pathways. Metabolomic analysis showed a decrease in nucleoside metabolite content and inhibition of niacinamide synthesis. Through SEA server and 3D molecular docking simulation analysis, it was found that glucose-6-phosphate dehydrogenase (G6PD) may be a potential target of cinobufagin. G6PD activity assay showed that cinobufagin could inhibit the catalytic ability of G6PD. EdU incorporation experiments showed that cinobufagin inhibited DNA synthesis in DLBCL cells. In addition, cinobufagin also promoted the up-regulation of NADP+/NADPH ratio and the increase of ROS. The addition of ROS scavengers and nucleotides partially reversed the apoptosis-inducing ability of cinobufagin. Conclusion:G6PD is a target of cinobufagin. By inhibiting the enzyme activity of G6PD, cinobufagin can inhibit DNA synthesis and the production of reducing NADPH, thereby inducing apoptosis of DLBCL cells. This suggests that Cinobufagin has potential application as a new drug for the treatment of DLBCL.

Long non-coding RNA SNHG17 may function as a competitive endogenous RNA in diffuse large B-cell lymphoma progression by sponging miR-34a-5p.

We investigated the functional mechanism of long non-coding small nucleolar host gene 17 (SNHG17) in diffuse large B-cell lymphoma (DLBCL). lncRNAs related to the prognosis of patients with DLBCL were screened to analyze long non-coding small nucleolar host gene 17 (SNHG17) expression in DLBCL and normal tissues, and a nomogram established for predicting DLBCL prognosis. SNHG17 expression in B-cell lymphoma cells was detected using qPCR. The effects of SNHG17 with/without doxorubicin on the proliferation and apoptosis of DoHH2 and Daudi were detected. The effects of combined SNHG17 and doxorubicin were analyzed. The regulatory function of SNHG17 in DLBCL was investigated using a mouse tumor xenotransplantation model. RNA sequencing was used to analyze the signaling pathways involved in SNHG17 knockdown in B-cell lymphoma cell lines. The target relationships among SNHG17, microRNA, and downstream mRNA biomolecules were detected. A higher SNHG17 level predicted a lower survival rate. SNHG17 was highly expressed in DLBCL patient tissues and cell lines. We established a prognostic model containing SNHG17 expression, which could effectively predict the overall survival rate of DLBCL patients. SNHG17 knockdown inhibited the proliferation and induced the apoptosis of B-cell lymphoma cells, and the combination of SNHG17 and doxorubicin had a synergistic effect. SNHG17, miR-34a-5p, and ZESTE gene enhancer homolog 2 (EZH2) had common hypothetical binding sites, and the luciferase reporter assay verified that miR-34a-5p was the direct target of SNHG17, and EZH2 was the direct target of miR-34a-5p. The carcinogenic function of SNHG17 in the proliferation and apoptosis of DLBCL cells was partially reversed by a miR-34a-5p inhibitor. SNHG17 increases EZH2 levels by inhibiting miR-34a-5p. Our findings indicate SNHG17 as critical for promoting DLBCL progression by regulating the EZH2 signaling pathway and sponging miR-34a-5p. These findings provide a new prognostic marker and therapeutic target for the prognosis and treatment of DLBCL.

Pulsatilla saponin A Inhibits Proliferation and Induces Apoptosis in Diffuse Large Bcell Lymphoma Cells through the JAK2/STAT3 Signaling Pathway.

This study aimed to investigate the performance of Pulsatilla saponin A (PsA) in diffuse large B-cell lymphoma (DLBCL) cells. Proliferation, ELISA, apoptosis, cell cycle analysis, and assays were carried out to detect the growth and apoptosis in DLBCL cells. Western blotting was used to identify the change in the protein. In cell assays, PsA significantly inhibited the growth and apoptosis in DLBCL cells. The IL-10 and TNF-α of OCI-LY10 and U2932 cells were reduced after 24 h PsA treatment. Bax, cleaved PARP, and cleaved Caspase-3 were increased, while Bcl-2 and C-Myc decreased after PsA treatment. IL-10 may regulate the expression of C-Myc protein in cells by activating the JAK2/STAT3 signaling pathway. PsA can inhibit the overexpression of p-JAK2 and p- STAT3 signaling pathways induced by IL-10 stimulants. The proliferation and apoptosis induced by PsA were confirmed in DLBCL cells. Our findings revealed that PsA may exert its antitumor effect by causing G1 arrest and apoptosis in DLBCL cells. The mechanism of PsA regulating apoptosis in DLBCL cells is probably through the JAK2/STAT3 signaling pathway in vitro.

Identification of lactate regulation pattern on tumor immune infiltration, therapy response, and DNA methylation in diffuse large B-cell lymphoma.

Lactate, produced through glycolytic metabolism in the tumor microenvironment (TME), is implicated in tumorigenesis and progression in diverse cancers. However, the impact of lactate on the remodeling of the TME in diffuse large B-cell lymphoma (DLBCL) and its implications for therapy options remain unclear. A lactate-related (LAR) scoring model was constructed in DLBCL patients using bioinformatic methods. CIBERSORT, XCELL, and ssGSEA algorithms were used to determine the correlation between LAR score and immune cell infiltration. Tumor Immune Dysfunction and Exclusion (TIDE), rituximab, cyclophosphamide, adriamycin, vincristine, and prednisone (R-CHOP) cohorts, and Genomics of Drug Sensitivity in Cancer (GDSC) were utilized to predict the therapeutic response of DLBCL patients. The impact of the hub gene STAT4 on tumor biological behavior and DNA methylation was experimentally validated or accessed by the TSIDE database. The LAR scoring model was developed based on 20 prognosis-related lactate genes, which enabled the division of DLBCL patients into high- and low-risk groups based on the median LAR score. Patients with high-risk DLBCL exhibited significantly worse survival outcomes in both the training cohorts (GSE181063) and the validation cohorts (GSE10846, GSE32918, and GSE69053), as indicated by statistically significant differences (all P<0.05) and area under the curve (AUC) values exceeding 0.6. Immune analyses revealed that low-risk DLBCL patients had higher levels of immune cell infiltration and antitumor immune activation compared to high-risk DLBCL patients. Furthermore, DLBCL patients with high LAR scores were associated with a lower TIDE value and poor therapeutic efficacy of the R-CHOP regimen. GDSC analysis identified 18 drugs that exhibited significant response sensitivity in low-risk DLBCL patients. Moreover, in vitro experiments demonstrated that overexpression of the lactate key gene STAT4 could suppress proliferation and migration, induce cell cycle arrest, and promote cell apoptosis in DLBCL cells. Transcriptional expression and methylation of the STAT4 gene were found to be associated with immunomodulators and chemokines. The lactate-based gene signature effectively predicts the prognosis and regulates TME in DLBCL. Our study underscores the role of lactate gene, STAT4, as an important tumor suppressor in DLBCL. Modulating STAT4 could be a promising strategy for DLBCL in clinical practice.

Effect of MELK Inhibitor OTSSP167 on Diffuse Large B-Cell Lymphoma

To investigate the effect of MELK inhibitor OTSSP167 against diffuse large B-cell lymphoma (DLBCL). The effect of OTSSP167 on activity, proliferation, and apoptosis of DLBCL cell line (SUDHL2 and HBL1) was detected by CCK-8 assay, 5-ethynyl-2'-deoxyuridine (EdU) staining, and Annexin V-FITC/PI double staining, respectively. DLBCL cells were inoculated into nude mice, after 4 weeks of OTSSP167 treatment, the effect of OTSSP167 on DLBCL growth in vivo was detected. Caspase-GloTM 3/7 enzyme activity assay kit was used to detect the effect of OTSSP167 on Caspase 3/7 enzyme activity of DLBCL cells. The expression levels of apoptosis and cycle-related proteins were detected by Western blot. OTSSP167 significantly inhibited the activity of SUDHL2 and HBL1 cells in a dose-dependent manner (r =-0.61, r =-0.52). EdU staining showed that OTSSP167 could significantly inhibit the proliferation of SUDHL2 and HBL1 cells. Annexin V-FITC/PI result showed that OTSSP167 could significantly promote the apoptosis of SUDHL2 and HBL1 cells (P <0.001). The result of in vivo experiment showed that OTSSP167 could inhibit the growth of SUDHL2 cells in nude mice. The result of TUNEL staining of tumor further confirmed that OTSSP167 could promote the apoptosis of SUDHL2 cells. Caspase 3/7 enzyme activity test demonstrated that OTSSP167 could significantly increase caspase activity in SUDHL2 and HBL1 cells (r =0.98, r =0.87). Western blot showed that OTSSP167 could dose-dependently inhibit the expression of PARP, Bcl-xL, and Bcl-2 in apoptosis signaling pathway (r =-0.93, r =-0.66, r =-0.87), while p53 protein was significantly up-regulated (r =0.82). The expression of cell cycle-related proteins cdc2, Cyclin E1, Cyclin A2, and Cyclin B1 also showed a dose-dependent down-regulation (r =-0.89, r =-0.83, r =-0.61, r =-0.93). The MELK inhibitor OTSSP167 can inhibit the proliferation and promote the apoptosis of DLBCL cells by inhibiting the expression of cycle-related proteins and anti-apoptosis-related proteins.

Ras interacting protein 1 facilitated proliferation and invasion of diffuse large B-cell lymphoma cells

ABSTRACT A GTPase binding protein, Ras interacting protein 1 (RASIP1), has been reported with a tumor-promoting role in lung cancer cells, and its role in lymphoma remains unknown. The analysis of medical databank shows that RASIP1 is upregulated in diffuse large B-cell lymphoma (DLBCL) specimens. In this article, we demonstrated that RASIP1 is highly expressed in DLBCL cell lines, compared with primary B cells. The gain- and loss-of-function experiments were performed to investigate the effects of RASIP1 on DLBCL cells. CCK-8, flow cytometry, western blot, and transwell assays demonstrated that silence of RASIP1 inhibited proliferation, cell cycle transition, and invasion and induced significant apoptosis in DLBCL cells, and ectopic expression of RASIP1 played opposite roles. Xenograft results revealed that RASIP1 facilitated the growth of DLBCL cells in vivo. These findings suggest that RASIP1 may be required for malignancy of DLBCL cells. In addition, we also found that the expression of RASIP1 was negatively regulated by forkhead box O3 (FOXO3), which has been reported to suppress the proliferation of DLBCL cells. Our results indicate that FOXO3 is bound to the promoter sequence of RASIP1 and inhibits its transcription. The suppressive effects of FOXO3 on proliferation and invasion of DLBCL cells were neutralized by RASIP1. In conclusion, we demonstrate that FOXO3 negatively regulated RASIP1 facilitates growth and invasion of DLBCL cells, provides novel diagnostic markers and therapeutic targets for DLBCL in clinic.

Overexpression of interleukin-20 correlates with favourable prognosis in diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common type of lymphoma worldwide, accounting for about 40% of cases. The role of cytokines in the pathogenesis of lymphomas has been rarely addressed, although cytokines have a close immunological relationship with lymphocytes. We observed overexpression of interleukin (IL)-20 in reactive germinal centres (GCs) leading us to hypothesise that IL-20 may play a role in lymphomagenesis. In this study, we surveyed for IL-20 expression in various types of lymphoma and found that IL-20 was expressed most frequently in follicular lymphoma (94%), but also in Burkitt lymphoma (81%), mantle cell lymphoma (57%), nodal marginal zone lymphoma (56%), Hodgkin lymphomas (50%), small lymphocytic lymphoma (50%) and diffuse large B-cell lymphoma (DLBCL, 48%). IL-20 was not expressed in extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), lymphoplasmacytic lymphoma, and plasmacytoma. T-cell lymphomas were largely negative for IL-20 expression, except for anaplastic large cell lymphoma (ALCL, 61%), which frequently expressed IL-20, especially in cutaneous ALCL, and showed an inverse association with ALK expression (p=0.024). We further tested IL-20 expression in another large cohort of DLBCL and found IL-20 expression more frequently in germinal centre B-cell (GCB) than in non-GCB subtype [16/26 (62%) versus 24/64 (38%), p=0.038]. In this cohort, IL-20 was associated with a lower rate of extranodal involvement (p=0.009), bone marrow involvement (p=0.040), and better overall survival (p=0.020). Mechanistically, IL-20 overexpression promoted G1 cell cycle arrest and subsequent apoptosis of DLBCL cells and vice versa invitro. We conclude that IL-20 may be involved in lymphomagenesis and may be useful as a prognostic marker in patients with DLBCL. In addition, IL-20 plays an inhibitory role in DLBCL growth, probably through cell cycle regulation.

Knockdown of the long non-coding RNA CACNA1G-AS1 enhances cytotoxicity and apoptosis of human diffuse large B cell lymphoma by regulating miR-3160-5p.

: Long non-coding RNAs (lncRNAs) have been confirmed to be connected with tumor proliferation, apoptosis, metastasis and recurrence. Previous studies have indicated that lncRNA calcium voltage-gated channel subunit α1 G (CACNA1G)-antisense 1 (AS1) can function as a pro-oncogene in several types of cancer. However, the specific role and mechanism of CACNA1G-AS1 have not been fully elucidated in human diffuse large B cell lymphoma (DLBCL). In the present study, CACNA1G-AS1 expression was verified in DLBCL tissues and cells by reverse transcription-quantitative PCR, and the relationship between CACNA1G-AS1 and microRNA (miR)-3160-5p was confirmed using luciferase reporter assays. After CACNA1G-AS1-knockdown and miR-3160-5p-overexpression, MTT, colony formation and flow cytometry assays were conducted to assess the changes in the cytotoxicity and apoptosis of OCI-Ly10 and SUDHL-4 cells. In addition, in vivo experiments were performed to determine the impact of CACNA1G-AS1-knockdown on tumor growth and apoptosis. It was revealed that CACNA1G-AS1 was highly expressed in DLBCL tissues and cells and that expression of CACNA1G-AS1 was associated with the clinical stage of DLBCL. Functionally, CACNA1G-AS1-knockdown was demonstrated to increase cytotoxicity and expedite apoptosis in DLBCL cells in vitro and in vivo. In addition, CACNA1G-AS1 could downregulate miR-3160-5p by targeting binding in DLBCL cells. Overexpression of miR-3160-5p had the same effects on the cytotoxicity and apoptosis of DLBCL cells as CACNA1G-AS1-knockdown. Overall, the present study revealed that CACNA1G-AS1-knockdown and miR-3160-5p-overexpression could prevent DLBCL carcinogenesis, which might provide novel therapeutic targets for DLBCL.

Decreased RNA‑binding protein IGF2BP2 downregulates NT5DC2, which suppresses cell proliferation, and induces cell cycle arrest and apoptosis in diffuse large B‑cell lymphoma cells by regulating the p53 signaling pathway.

Diffuse large B-cell lymphoma (DLBCL) remains difficult to treat clinically due to its highly aggressive characteristics. Insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) and 5′-nucleotidase domain-containing 2 (NT5DC2) have been suggested as potential regulators in numerous types of cancer. The present study aimed to determine whether downregulation of IGF2BP2 and NT5DC2 suppresses cell proliferation, and induces cell cycle arrest and apoptosis in DLBCL cells by regulating the p53 signaling pathway. The expression levels of IGF2BP2 and NT5DC2 in DLBCL cells were determined by reverse transcription-quantitative PCR (RT-qPCR) and western blot analysis. Transfection of cells with IGF2BP2 overexpressing plasmids and NT5DC2 interference plasmids was performed, and the efficacy of transfection was confirmed by RT-qPCR and western blot analysis. The viability, proliferation, cell cycle progression and apoptosis of DLBCL cells were analyzed by Cell Counting Kit-8 assay, 5-bromo-2-deoxyuridine staining and flow cytometry. RNA pull-down and immunoprecipitation assays were used to verify the binding of IGF2BP2 and NT5DC2. The expression levels of apoptosis, cell cycle and p53 pathway-associated proteins were determined by western blotting. The results revealed that NT5DC2 expression was increased in DLBCL cell lines and was the highest in OCI-Ly7 cells. IGF2BP2 expression was also increased in OCI-Ly7 cells and IGF2BP2 bound to NT5DC2. Knockdown of NT5DC2 suppressed cell viability and proliferation, induced cell cycle arrest and promoted apoptosis in DLBCL cells, which was reversed by upregulation of IGF2BP2. In addition, knockdown of NT5DC2 increased the expression of p53 and p21, but suppressed the expression of proliferating cell nuclear antigen, CDK4 and cyclin D1; these effects were reversed by upregulation of IGF2BP2. In conclusion, knockdown of NT5DC2 suppressed cell viability and proliferation, induced cell cycle arrest and promoted apoptosis in DLBCL cells by regulating the p53 signaling pathway and these effects were reversed by upregulation of IGF2BP2.

Effects of hsa-miR-28-5p on Adriamycin Sensitivity in Diffuse Large B-Cell Lymphoma.

Background Adriamycin (doxorubicin) is an important traditional drug that exhibits cytotoxicity in Diffuse Large B-cell Lymphoma (DLBCL). Doxorubicin affects the DLBCL cells at all stages of their cell cycle. Combined with our previous results, this study discovered that the overexpression of hsa-miR-28-5p inhibited the proliferation, promoted apoptosis, and triggered cell cycle arrest at the S-phase in DLBCL cells. However, the effect of (Homo sapiens, hsa)-microRNA (miR)-28-5p on doxorubicin sensitivity in DLBCL has not been investigated. This study aims to reveal the effects of hsa-miR-28-5p on doxorubicin sensitivity at the level of DLBCL cells. Methods To determine the optimal concentration of doxorubicin, different concentrations of doxorubicin were used to treat DLBCL cells. CCK-8 assay was used to detect the proliferation of DLBCL cells. The hsa-miR-28-5p-mimic NC and hsa-miR-28-5p mimic were transfected to doxorubicin-mediated DLBCL cells. Simultaneously, blank control groups were set up. The cells were cultured and transfected for 24 h. Next, each group was administered with different concentrations of doxorubicin and cultured again for 24 h to observe the effects of hsa-miR-28-5p on doxorubicin sensitivity at different times. The proliferation, early apoptosis, and late apoptosis in DLBCL cells were determined using soft agar colony-forming assay, mitochondrial membrane potential assay, and caspase-3 activity assay, respectively. The apoptosis and cell cycle were explored using Annexin V-PE/7-AAD and PI/RNase staining buffer, respectively. We speculated that PD-L1 might be involved in the effect of hsa-miR-28-5p on the sensitivity of adriamycin (doxorubicin) in the DLBCL cells. Hence, we performed immunohistochemistry (IHC) to determine PD-L1 expression within formalin-fixed paraffin-embedded (FFPE) samples from 52 DLBCL cases. Results The optimal concentration of doxorubicin targeting DLBCL cells was found to be 3.028 μmol/l. The effect of doxorubicin on DLBCL cells was time- and concentration-dependent. hsa-miR-28-5p mimic + doxorubicin remarkably decreased proliferation of DLBCL. DLBCL cell apoptosis rate was the highest in hsa-miR-28-5p mimic + doxorubicin group. Apart from that, hsa-miR-28-5p mimic plus doxorubicin had the best effect in promoting DLBCL cell apoptosis. After the intervention of hsa-miR-28-5p mimic + doxorubicin on DLBCL cells, the cell cycle was arrested in the S-phase and DNA synthesis was blocked. hsa-miR-28-5p mimic + doxorubicin could regulate the cycle of DLBCL cells. As a result, overexpression of hsa-miR-28-5p combined with doxorubicin is possibly involved in the development of DLBCL by affecting the proliferation, apoptosis, and cycle of DLBCL cells. PD-L1 showed an association with the prognosis of DLBCL patients. Combining with the literature, this suggested hsa-miR-28-5p may influence DLBCL occurrence and therapeutic effect by regulating the PD-L1 level. Conclusion The combination of hsa-miR-28-5p mimic and doxorubicin may be considered more effective in inhibiting growth, arresting the cell cycle, and promoting cell apoptosis of DLBCL cells compared to using doxorubicin alone. The effects of doxorubicin on DLBCL cells were found to be time- and concentration-dependent. The overexpression of hsa-miR-28-5p enhanced the effect of doxorubicin on DLBCL cells, which may be attributed to the regulation of PD-L1 levels.

A novel Gboxin analog induces OXPHOS inhibition and mitochondrial dysfunction-mediated apoptosis in diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is an aggressive B-cell non-Hodgkin's lymphoma. Currently, moderate efficacy and limitations of approved drugs still exist, and it is necessary to develop newer and more effective drugs. Gboxin is a promising inhibitor of OXPHOS, which specifically inhibits the growth of many kinds of cancer cell lines. In the present study, 21 Gboxin analogs incorporating amide and ester moieties were designed and synthesized. Preliminary screening results show that 5d also has specific selectivity for cancer cells, particularly on the DLBCL cells, which is weaker than that of Gboxin but still good. Thus, the effect and underlying mechanism of 5d on DLBCL cells were further studied. The results showed that 5d exhibits potent proliferation inhibition and cell cycle arrest effects, and its IC50 to DLBCL cells is below 1 µM. In addition, 5d induces apoptosis of DLBCL cells in a time- and dose-dependent manner, and this effect is stronger than that of Gboxin and VP16. Mechanistically, 5d plays its role mainly through the stimulation of metabolic stress in DLBCL cell lines, which induces OXPHOS inhibition, inflammation, DNA damage and mitochondrial dysfunction. These data suggest that 5d has potential as a candidate agent for DLBCL alternative drug development.