P38 MAPK expression and activation predicts failure of response to CHOP in patients with Diffuse Large B-Cell Lymphoma

Intratumoral T-cell composition predicts epcoritamab-based treatment efficacy in B-cell non-Hodgkin lymphomas

Leveraging endogenous tumor-resident T-cells for immunotherapy using bispecific antibodies (BsAb) targeting CD20 and CD3 has emerged as a promising therapeutic strategy for patients with B-cell non-Hodgkin lymphomas. However, features associated with treatment response or resistance are unknown. To this end, we analyzed data from patients treated with epcoritamab-containing regimens in the EPCORE NHL-2 trial (NCT04663347). We observed downregulation of CD20 expression on B-cells following treatment initiation both in progressing patients and in patients achieving durable complete responses (CR), suggesting that CD20 downregulation does not universally predict resistance to BsAb-based therapy. Single-cell immune profiling of tumor biopsies obtained following one cycle of therapy revealed substantial clonal expansion of cytotoxic CD4+ and CD8+ T-cells in patients achieving CR, and an expansion of follicular helper and regulatory CD4+ T-cells in patients whose disease progressed. These results identify distinct tumor-resident T-cell profiles associated with response or resistance to BsAb therapy.

Sulfated Laminarin Polysaccharides Reduce the Adhesion of Nano-COM Crystals to Renal Epithelial Cells by Inhibiting Oxidative and Endoplasmic Reticulum Stress

Purpose: Adhesion between calcium oxalate crystals and renal tubular epithelial cells is a vital cause of renal stone formation; however, the drugs that inhibit crystal adhesion and the mechanism of inhibition have yet to be explored. Methods: The cell injury model was constructed using nano-COM crystals, and changes in oxidative stress levels, endoplasmic reticulum (ER) stress levels, downstream p38 MAPK protein expression, apoptosis, adhesion protein osteopontin expression, and cell-crystal adhesion were examined in the presence of Laminarin polysaccharide (DLP) and sulfated DLP (SDLP) under protected and unprotected conditions. Results: Both DLP and SDLP inhibited nano-COM damage to human kidney proximal tubular epithelial cell (HK-2), increased cell viability, decreased ROS levels, reduced the opening of mitochondrial membrane permeability transition pore, markedly reduced ER Ca2+ ion concentration and adhesion molecule OPN expression, down-regulated the expression of ER stress signature proteins including CHOP, Caspase 12, and p38 MAPK, and decreased the apoptosis rate of cells. SDLP has a better protective effect on cells than DLP. Conclusions: SDLP protects HK-2 cells from nano-COM crystal-induced apoptosis by reducing oxidative and ER stress levels and their downstream factors, thereby reducing crystal-cell adhesion interactions and the risks of kidney stone formation.

p38 Molecular Targeting for Next-Generation Multiple Myeloma Therapy

Resistance to therapy and disease progression are the main causes of mortality in most cancers. In particular, the development of resistance is an important limitation affecting the efficacy of therapeutic alternatives for cancer, including chemotherapy, radiotherapy, and immunotherapy. Signaling pathways are largely responsible for the mechanisms of resistance to cancer treatment and progression, and multiple myeloma is no exception. p38 mitogen-activated protein kinase (p38) is downstream of several signaling pathways specific to treatment resistance and progression. Therefore, in recent years, developing therapeutic alternatives directed at p38 has been of great interest, in order to reverse chemotherapy resistance and prevent progression. In this review, we discuss recent findings on the role of p38, including recent advances in our understanding of its expression and activity as well as its isoforms, and its possible clinical role based on the mechanisms of resistance and progression in multiple myeloma.

Mechanism of action and therapeutic targeting of CD30 molecule in lymphomas

At present, the treatment of lymphoma has entered the era of precision medicine, and CD30, as a transmembrane protein, has become an important marker to help the diagnosis and formulation of treatment plans for lymphomas. This protein is widely expressed in various types of lymphomas and can play a role through nuclear factor-κB (NF-κB), mitogen-activated protein kinase (MAPK), and other pathways, and ultimately lead to the up-regulation of CD30 expression to give tumor cells a survival advantage. Brentuximab vedotin (BV), as an antibody-drug conjugate (ADC) targeting CD30, is one of the first new drugs to significantly improve survival in patients with CD30+lymphomas. However, the biological function of CD30 has not been fully elucidated. Therefore, this review highlights the CD30-mediated tumor-promoting mechanisms and the molecular factors that regulate CD30 expression. We hope that a better understanding of CD30 biology will provide new insights into clinical treatment and improve the survival and quality of life of lymphoma patients.

Identification and overcoming rituximab resistance in diffuse large B-cell lymphoma using next-generation sequencing

BACKGROUND/AIMS

Although rituximab, an antiCD20 monoclonal antibody, has dramatically improved the clinical outcomes of diffuse large B-cell lymphoma, rituximab resistance remains a challenge.

METHODS

We developed a rituximab-resistant cell line (RRCL) by sequential exposure to gradually increasing concentrations of rituximab in a rituximab-sensitive cell line (RSCL). When the same dose of rituximab was administered, RRCL showed a smaller decrease in cell viability and apoptosis than RSCL. To determine the differences in gene expression between RSCL and RRCL, we performed next-generation sequencing.

RESULTS

In total, 1,879 differentially expressed genes were identified, and in the over-representation analysis of Consensus-PathDB, mitogen-activated protein kinase (MAPK) signaling pathway showed statistical significance. MAPK13, which encodes the p38δ protein, was expressed more than four-fold in RRCL. Western blot analysis revealed that phosphop38 expression mainwas increased in RRCL, and when p38 inhibitor was administered, phosphop38 expression was significantly decreased. Therefore, we hypothesized that p38 MAPK activation was associated with rituximab resistance. Previous studies have suggested that p38 is associated with NF-κB activation. Deferasirox has been reported to inhibit NF-κB activity and suppress phosphorylation of the MAPK pathway. Furthermore, it also has cytotoxic effects on various cancers and synergistic effects in overcoming drug resistance. In this study, we confirmed that deferasirox induced dose-dependent cytotoxicity in both RSCL and RRCL, and the combination of deferasirox and rituximab showed a synergistic effect in RRCL at all combination concentrations.

CONCLUSION

We suggest that p38 MAPK, especially p38δ, activation is associated with rituximab resistance, and deferasirox may be a candidate to overcome rituximab resistance.

Obesity and Risk for Lymphoma: Possible Role of Leptin

Obesity, which is considered a pandemic due to its high prevalence, is a risk factor for many types of cancers, including lymphoma, through a variety of mechanisms by promoting an inflammatory state. Specifically, over the last few decades, obesity has been suggested not only to increase the risk of lymphoma but also to be associated with poor clinical outcomes and worse responses to different treatments for those diseases. Within the extensive range of proinflammatory mediators that adipose tissue releases, leptin has been demonstrated to be a key adipokine due to its pleotropic effects in many physiological systems and diseases. In this sense, different studies have analyzed leptin levels and leptin/leptin receptor expressions as a probable bridge between obesity and lymphomas. Since both obesity and lymphomas are prevalent pathophysiological conditions worldwide and their incidences have increased over the last few years, here we review the possible role of leptin as a promising proinflammatory mediator promoting lymphomas.

Orelabrutinib and venetoclax synergistically induce cell death in double-hit lymphoma by interfering with the crosstalk between the PI3K/AKT and p38/MAPK signaling

PURPOSE

Double-hit lymphoma (DHL) is a rare and aggressive mature B-cell malignancy with concurrent MYC and BCL2 rearrangements. When DHL becomes relapsed or refractory, it becomes resistant to the majority of therapeutic approaches and has subpar clinical results. Therefore, innovative therapeutics for this particular patient population are urgently needed.

METHODS

Orelabrutinib, a new oral BTK inhibitor, combined with the Bcl-2 inhibitor venetoclax, was used to confirm the antitumor effect of DHL. Cell counting kit-8 and Annexin V-FITC/PI assays were used to examine the interaction of this combined regimen on DHL cell lines and primary lymphoma cells. RNA sequencing, EdU incorporation assay, mitochondrial membrane potential assay, and western blotting were employed to explore the molecule mechanism for the cytotoxicity of orelabrutinib with or without venetoclax against DHL cell lines.

RESULTS

In this study, orelabrutinib combined with venetoclax synergistically induced DHL cell death, as evidenced by the inhibition of cell proliferation, the induct of cell cycle arrest, and the promotion of cell apoptosis via the mitochondrial pathway. Orelabrutinib treatment alters genome-wide gene expression in DHL cells. The combined regimen decreases the expression of BTK and Mcl-1, potentially interfering with the activity and crosstalk of PI3K/AKT signaling and p38/MAPK signaling. In addition, the combination of orelabrutinib and venetoclax shows cytotoxic activity in primary B-lymphoma cells.

CONCLUSION

In summary, these findings reveal a novel therapy targeting BCR signaling and the Bcl-2 family for DHL patients with a poor prognosis.

Inhibition of p38 MAPK or immunoproteasome overcomes resistance of chronic lymphocytic leukemia cells to Bcl-2 antagonist venetoclax

Chronic lymphocytic leukemia (CLL) is a hematological neoplasm of CD19-positive mature-appearing B lymphocytes. Despite the clinical success of targeted therapies in CLL, the development of resistance diminishes their therapeutic activity. This is also true for the Bcl-2 antagonist venetoclax. We investigated the molecular mechanisms that drive venetoclax resistance in CLL, with a clear focus to provide new strategies to successfully combat it. Activation of CLL cells with IFNγ, PMA/ionomycin, and sCD40L diminished the cytotoxicity of venetoclax. We demonstrated that the metabolic activity of cells treated with 1 nM venetoclax alone was 48% of untreated cells, and was higher for cells co-treated with IFNγ (110%), PMA/ionomycin (78%), and sCD40L (62%). As of molecular mechanism, we showed that PMA/ionomycin and sCD40L triggered translocation of NFκB in primary CLL cells, while IFNγ activated p38 MAPK, suppressed spontaneous and venetoclax-induced apoptosis and induced formation of the immunoproteasome. Inhibition of immunoproteasome with ONX-0914 suppressed activity of immunoproteasome and synergized with venetoclax against primary CLL cells. On the other hand, inhibition of p38 MAPK abolished cytoprotective effects of IFNγ. We demonstrated that venetoclax-resistant (MEC-1 VER) cells overexpressed p38 MAPK and p-Bcl-2 (Ser70), and underexpressed Mcl-1, Bax, and Bak. Inhibition of p38 MAPK or immunoproteasome triggered apoptosis in CLL cells and overcame the resistance to venetoclax of MEC-1 VER cells and venetoclax-insensitive primary CLL cells. In conclusion, the p38 MAPK pathway and immunoproteasome represent novel targets to combat venetoclax resistance in CLL.

A single-cell atlas of diffuse large B cell lymphoma

Diffuse large B cell lymphoma (DLBCL) is one of the most common yet aggressive types of B cell lymphoma and remains incurable in 40% of patients. Herein, we profile the transcriptomes of 94,324 cells from 17 DLBCLs and 3 control samples using single-cell RNA sequencing. Altogether, 73 gene expression programs are identified in malignant cells, demonstrating high intra- and intertumor heterogeneity. Furthermore, 2,754 pairs of suggestive cell-cell interactions are predicted, indicating a complex and highly dynamic tumor microenvironment. Especially for B cell lymphomas, a strong costimulatory CD70-CD27 interaction is predicted between malignant and T cells. Furthermore, coinhibitory signals mediated by TIM3 or TIGIT seem to be the main driving force for T cell exhaustion. Finally, we find that chronic hepatitis B virus infection may have a significant impact on tumor cell survival and immune evasion in DLBCL. Our results provide insights into B cell lymphomagenesis and may facilitate the design of targeted immunotherapy strategies.

PAK4 and NAMPT as Novel Therapeutic Targets in Diffuse Large B-Cell Lymphoma, Follicular Lymphoma, and Mantle Cell Lymphoma

Simple Summary

Non-Hodgkin’s lymphomas (NHL) are cancers of the white blood cells. While some NHL subtypes, such as Diffuse large B-cell lymphoma (DLBCL) and mantle cell lymphoma (MCL), grow and spread aggressively, others, like follicular lymphoma (FL), are indolent in nature. Irrespective of how fast they grow, all NHL subtypes can spread to other organs in the body if not treated. In this study, we have demonstrated that the targeted inhibition of p21-activated kinase 4 (PAK4) and nicotinamide phosphoribosyl transferase (NAMPT) in different NHL subtypes by a novel, orally bioavailable, dual inhibitor KPT-9274 can lead to energy depletion, inhibition of cell proliferation, and ultimately apoptosis. KPT-9274 treatment shows potent anti-tumor effects in DLBCL and MCL subcutaneous xenograft models and enhances mice survival in a systemic FL model. Therefore, this study demonstrates the potential of targeting PAK4 and NAMPT by a small molecule inhibitor KPT-9274 for NHL therapy.

Abstract

Diffuse large B-cell lymphoma (DLBCL), grade 3b follicular lymphoma (FL), and mantle cell lymphoma (MCL) are aggressive non-Hodgkin’s lymphomas (NHL). Cure rates are suboptimal and novel treatment strategies are needed to improve outcomes. Here, we show that p21-activated kinase 4 (PAK4) and nicotinamide phosphoribosyl transferase (NAMPT) is critical for lymphoma subsistence. Dual targeting of PAK4-NAMPT by the Phase I small molecule KPT-9274 suppressed cell proliferation in DLBCL, FL, and MCL. Growth inhibition was concurrent with apoptosis induction alongside activation of pro-apoptotic proteins and reduced pro-survival markers. We observed NAD suppression, ATP reduction, and consequent cellular metabolic collapse in lymphoma cells due to KPT-9274 treatment. KPT-9274 in combination with standard-of-care chemotherapeutics led to superior inhibition of cell proliferation. In vivo, KPT-9274 could markedly suppress the growth of WSU-DLCL2 (DLBCL), Z-138, and JeKo-1 (MCL) sub-cutaneous xenografts, and a remarkable increase in host life span was shown, with a 50% cure of a systemic WSU-FSCCL (FL) model. Residual tumor analysis confirmed a reduction in total and phosphorylated PAK4 and activation of the pro-apoptotic cascade. This study, using various preclinical experimental models, demonstrates the therapeutic potential of targeting PAK4-NAMPT in DLBCL, FL, and MCL. The orally bioavailable, safe, and efficacious PAK4-NAMPT dual inhibitor KPT-9274 warrants further clinical investigation.

Salvianolic acid A inhibits the growth of diffuse large B-cell lymphoma through MAPK pathways

Treatment options are limited in patients with diffuse large B-cell lymphoma (DLBCL). Salvianolic acid A (SAA) is a water-soluble phenolic acid extracted from Salvia miltiorrhiza (Danshen) with anti-tumor properties. The anti-leukemic activity of SAA found in our recent research prompted us to investigate the therapeutic effect and mechanism of action of SAA in DLBCL. In the work described here, we found that SAA inhibited the viability of DLBCL cells by inducing cellular apoptosis, which was accompanied by upregulation of Bax and cleavage of PARP. Pre-incubation of SAA increased the phosphorylation of JNK, while it decreased the phosphorylation of p38 and ERK in DLBCL cells. Importantly, pharmacologic JNK inhibition partially mitigated the anti-survival effect of SAA, and inhibition of p38 and ERK synergized with SAA. Furthermore, SAA suppressed DLBCL tumor growth in a xenograft mouse model in vivo. Therefore, our data suggest the therapeutic utility of SAA in the management of DLBCL.

P38-β/SAPK-inhibiting and apoptosis-inducing activities of (E)-4-chloro-2-((3-ethoxy-2-hydroxybenzylidene) amino)phenol

The present study has three purposes; first evaluating cytotoxicity of (E)-4-chloro-2-((3-ethoxy-2-hydroxybenzylidene)amino)phenol (ACES), second deciphering ACES-mediated cellular death mechanism, and third estimating ACES-mediated alterations in the expressions of mitogen-activated protein kinase (MAPK) pathway-related genes. Neutral red uptake assay, cell cycle analysis, mitochondrial membrane potential (MMP), reactive oxygen species (ROS) measurements, caspase 3/7 and 9 activations, and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) were implemented. IC₅₀ values of ACES-treated five cells were around 4-6 µg/mL. However, Caco-2 and Huh-7 cells were found to be twofold resistant and fivefold sensitive with IC₅₀ values of 11 µg/mL and 0.93 µg/mL, respectively. In this study, it was initially reported that ACES exhibits selective cytotoxicity to Huh-7 cells. In addition, ACES induced apoptosis by nuclear fragmentation, MMP disruption, and intracellular ROS elevation in MCF-7 cells. qRT-PCR experiment indicated the expressions of 30 genes including ATF2, CREB1, MYC, NFATC4 (NFAT3), CCNA1, CCNB1, CCND2, CDK2, CDKN1A (p21CIP1), CDKN1C (p57KIP2), CDKN2A (p16INK4a), CDKN2B (p15INK4b), DLK1, NRAS, CDC42, PAK1, MAP4K1 (HPK1), MAP3K3 (MEKK3), MAP2K3 (MEK3), MAP2K6 (MEK6), MOS, MAPK1 (ERK2), MAPK8 (JNK1), MAPK10 (JNK3), MAPK11 (p38-β), LAMTOR3 (MP1), MAPK8IP2 (JIP-1), PRDX6 (AOP2), COL1A1, and HSPA5 (Grp78) were downregulated at least 1.5-fold. Moreover, ACES effectively inhibited expressions of genes that code for elements of p38-β/stress-activated protein kinase (SAPK) pathway. ACES has the potential to be used for the reversal of trastuzumab resistance in breast cancer patients by inhibiting p38/SAPK pathway in MCF-7 cells. Therefore, with the selective cytotoxic, apoptosis-inducing, and p38-β/SAPK-inhibiting activities, ACES can be utilized for developing a novel anticancer drug.

The critical role of RasGRP4 in the growth of diffuse large B cell lymphoma

Background

This study aimed to confirm that blocking RasGRP4 can effectively slow down the growth of DLBCL both in vitro and in vivo and ascertain the role of RasGRP4 in the prognosis of DLBCL clinically.

Methods

RasGRP4 expression levels were examined in benign tissues and lymphomas. In order to verify somatic mutation in RasGRP4 gene, cDNA sequencing was performed in DLBCL patients. RasGRP4-dependent cell proliferation, mitochondrial membrane potential, oxidative stress levels and signaling pathway changes were measured by knockdown of RasGRP4. Tumor growth was monitored in xenografted lymphoma model. Clinical data were collected to confirm the role of RasGRP4 in DLBCL.

Results

RasGRP4 expression was significantly elevated in DLBCL while no somatic mutations were detected of this gene in DLBCL patients. Decreased RasGRP4 significantly inhibited cell proliferation by simultaneously reducing mitosis and promoting apoptosis and increased the oxidative stress levels. Mechanistically, reduced expression of RasGRP4 decreased ERK while increased JNK expression in SUDHL-4 cells. Knockdown of RasGRP4 also significantly inhibited tumor formation in vivo. Furthermore, RasGRP4 expression levels were significantly higher in patients with larger DLBCL lesions (P = 0.0004), high-risk international prognostic index score groups (P = 0.0042), and its expression was positively correlated with maximum standardized uptake value in DLBCL (P = 0.0004).

Conclusions

These findings indicate the oncogenic role of RasGRP4 in DLBCL, suggesting it as a prognostic biomarker and potential therapeutic target in DLBCL.

Electronic supplementary material

The online version of this article (10.1186/s12964-019-0415-6) contains supplementary material, which is available to authorized users.

Regulation of Krüppel-Like Factor 4 (KLF4) expression through the transcription factor Yin-Yang 1 (YY1) in non-Hodgkin B-cell lymphoma

Krüppel-Like Factor 4 (KLF4) is a member of the KLF transcription factor family, and evidence suggests that KLF4 is either an oncogene or a tumor suppressor. The regulatory mechanism underlying KLF4 expression in cancer, and specifically in lymphoma, is still not understood. Bioinformatics analysis revealed two YY1 putative binding sites in the KLF4 promoter region (-950 bp and -105 bp). Here, the potential regulation of KLF4 by YY1 in NHL was analyzed. Mutation of the putative YY1 binding sites in a previously reported system containing the KLF4 promoter region and CHIP analysis confirmed that these binding sites are important for KLF4 regulation. B-NHL cell lines showed that both KLF4 and YY1 are co-expressed, and transfection with siRNA-YY1 resulted in significant inhibition of KLF4. The clinical implications of YY1 in the transcriptional regulation of KLF4 were investigated by IHC in a TMA with 43 samples of subtypes DLBCL and FL, and all tumor tissues expressing YY1 demonstrated a correlation with KLF4 expression, which was consistent with bioinformatics analyses in several databases. Our findings demonstrated that KLF4 can be transcriptionally regulated by YY1 in B-NHL, and a correlation between YY1 expression and KLF4 was found in clinical samples. Hence, both YY1 and KLF4 may be possible therapeutic biomarkers of NHL.

Identification of B-cell translocation gene 1-controlled gene networks in diffuse large B-cell lymphoma: A study based on bioinformatics analysis

B-cell translocation gene 1 (BTG1) is a member of the BTG/transducer of Erb family. The present study evaluated the impact of BTG1 gene expression on the clinical outcome of diffuse large B-cell lymphoma (DLBCL) and investigated potential mechanisms using the Gene Expression Omnibus (GEO) database. The gene expression profile datasets GSE31312, GSE10846, GSE65420 and GSE87371 were downloaded from the GEO database. BTG1 expression and clinicopathological data were obtained from the GSE31312 dataset. In 498 cases, the expression of BTG1 in DLBCL was associated with treatment response (χ²=19.020; P<0.001) and International Prognostic Index score (χ²=5.320; P=0.025). Using the Kaplan-Meier method, it was identified that the expression of BTG1 was associated with overall survival (OS) and progression-free survival (PFS) times. Univariate and multivariate Cox regression analysis demonstrated that BTG1 was an independent predictive factor for OS and PFS. From the overlapping analysis of 407 BTG1-associated genes and 22,187 DLBCL-associated genes, 401 genes were identified as BTG1-associated DLBCL genes. Pathway analysis revealed that BTG1-associated DLBCL genes were associated with cancer progression and DLBCL signaling pathways. Subsequently, a protein-protein interaction network was constructed of the BTG1-associated genes, which consisted of 235 genes and 601 interactions. Additionally, 24 genes with high degrees in the network were identified as hub genes, which included genes associated with ‘ribosome’ [ribosomal protein (RP) L11, RPL3, RPS29, RPL19, RPL15 and RPL12], ‘cell cycle’ (ubiquitin carboxyl extension protein 52, ATM and Ras homolog family member H), ‘mitogen-activated protein kinase pathway’ (mitogen-activated protein kinase 1), ‘histone modification’ (ASH1-like protein) and ‘transcription/translation’ (eukaryotic translation initiation factor 3 subunit E, eukaryotic translation elongation factor 1 δ, transcription termination factor 1, cAMP responsive element binding protein 1 and RNA polymerase II subunit F). In conclusion, BTG1 may serve as a predictive biomarker for DLBCL prognosis. Additionally, bioinformatics analysis indicated that BTG1 may exhibit key functions in the progression and development of DLBCL.

Integration of bioinformatics and experiments to identify TP53 as a potential target in Emodin inhibiting diffuse large B cell lymphoma

Non-Hodgkin's Lymphoma (NHL) is a group of lymphoid malignancies with unsatisfactory treatment effect in some aggressive subtypes, including diffuse large B cell lymphoma (DLBCL). Emodin is an anthraquinone with potent anti-cancer activities. However, the molecular mechanism of Emodin repressing aggressive NHL remains to be revealed in detail. This study delineated the active mechanism of Emodin action in aggressive NHL by using bioinformatics analysis and in vitro assay. 4 Emodin's primary direct protein targets (DPT) were identified and the DPTs-associated proteins/genes were predicted. Those Emodin-related proteins/genes were subject to enrich Emodin-associated pathways, from which 3 significantly NHL-related signal pathways were refined identified. Advanced integrated analysis exhibited TP53 and PI3K as the significant molecule and pathway by which Emodin may function in NHL. To verify those bioinformatics findings, effects of Emodin and E35, a novel derivative of emodin were investigated on DLBCL cell lines SU-DHL4. Emodin and E35 suppressed proliferation and induced apoptosis of SU-DHL4 cells in a time- and dose-dependent manner. Emodin and E35 declined TP53 protein expression and decreased phosphorylation of PI3K/AKT protein in a dose-dependent manner. All of above showed that combined bioinformatics analysis with experiments offered a novel approach for outlining the mechanisms of Emodin action in DLBCL with convenience and integrity.

Qiang-Xin 1 Formula Prevents Sepsis-Induced Apoptosis in Murine Cardiomyocytes by Suppressing Endoplasmic Reticulum- and Mitochondria-Associated Pathways

Sepsis is reported to be an unusual systemic reaction to infection, accompanied by multiple-organ failure. Sepsis-induced cardiomyopathy (SIC), defined as damages and dysfunction of the heart, is essential in the pathogenesis of sepsis. Traditional Chinese formula, which has long been used to improve the situation of patients through multitarget regulation, is now gradually being used as complementary therapy. The present study aimed to investigate the effect of Qiang-Xin 1 (QX1) formula, a traditional Chinese herbal medicine designed for cardiac dysfunction, on cecal ligation puncture (CLP)-induced heart damage and its underlying mechanisms in mice. Survival test first showed that an oral administration of QX1 formula significantly increased the 7-days survival of septic mice from 22 to 40%. By estimating the secretion of serum cytokines, QX1 treatment dramatically inhibited the excessive production of interleukin-1β and tumor necrosis factor-α. Immunohistochemical staining illustrated that the expression of c-Jun N-terminal kinase, caspase-12, and high-mobility group box 1 was downregulated in cardiomyocytes of the QX1-treated group compared with that of the CLP surgery group. Western blotting confirmed that the activation of essential caspase family members, such as caspase-3, caspase-9, and caspase-12, was prohibited by treatment with QX1. Moreover, the abnormal expression of key regulators of endoplasmic reticulum (ER) and mitochondria-associated apoptosis in cardiomyocytes of septic mice, including CHOP, GRP78, Cyt-c, Bcl-2, Bcl-X_L, and Bax, was effectively reversed by treatment with QX1 formula. This study provided a new insight into the role of QX1 formula in heart damage and potential complementary therapeutic effect of traditional Chinese medicine on sepsis.

Key Players of Cisplatin Resistance: Towards a Systems Pharmacology Approach

The major obstacle in the clinical use of the antitumor drug cisplatin is inherent and acquired resistance. Typically, cisplatin resistance is not restricted to a single mechanism demanding for a systems pharmacology approach to understand a whole cell's reaction to the drug. In this study, the cellular transcriptome of untreated and cisplatin-treated A549 non-small cell lung cancer cells and their cisplatin-resistant sub-line A549^rCDDP²⁰⁰⁰ was screened with a whole genome array for relevant gene candidates. By combining statistical methods with available gene annotations and without a previously defined hypothesis HRas, MAPK14 (p38), CCL2, DOK1 and PTK2B were identified as genes possibly relevant for cisplatin resistance. These and related genes were further validated on transcriptome (qRT-PCR) and proteome (Western blot) level to select candidates contributing to resistance. HRas, p38, CCL2, DOK1, PTK2B and JNK3 were integrated into a model of resistance-associated signalling alterations describing differential gene and protein expression between cisplatin-sensitive and -resistant cells in reaction to cisplatin exposure.

Whole-exome and transcriptome sequencing of refractory diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma. Although rituximab therapy improves clinical outcome, some patients develop resistant DLBCL; however, the genetic alterations in these patients are not well documented. To identify the genetic background of refractory DLBCL, we conducted whole-exome sequencing and transcriptome sequencing for six patients with refractory and seven with responsive DLBCL. The average numbers of pathogenic somatic single nucleotide variants and indels in coding regions were 71 in refractory patients (range 28–120) and 38 (range 19–66) in responsive patients. Missense mutations of TP53 were exclusive in 50% (3/6) of refractory patients and involved the DNA-binding domain of TP53. All missense mutations of TP53 were accompanied by copy number deletions. RAB11FIP5, PRKCB, PRDM15, FNBP4, AHR, CEP128, BRE, DHX16, MYO6, and NMT1 mutations were recurrent in refractory patients. MYD88, B2M, SORCS3, and WDFY3 mutations were more frequent in refractory patients than in responsive patients. REL–BCL11A fusion was found in two refractory patients; one had both fusion and copy number gain. Recurrent copy gains of POU2AF1, SLC1A4, REL11, FANCL, CACNA1D, TRRAP, and CUX1 with significantly increased average expression were found in refractory patients. The expression profile revealed enriched gene sets associated with treatment resistance, including oxidative phosphorylation and ATP-binding cassette transporters. In conclusion, this study integrated both genomic and transcriptomic alterations associated with refractory DLBCL and found several treatment-resistance alterations that may contribute to refractoriness.

Discovery and validation of the tumor-suppressive function of long noncoding RNA PANDA in human diffuse large B-cell lymphoma through the inactivation of MAPK/ERK signaling pathway

Diffuse large B-cell lymphoma (DLBCL) is one of the leading causes of cancer-related mortality, and responds badly to existing treatment. Thus, it is of urgent need to identify novel prognostic markers and therapeutic targets of DLBCL. Recent studies have shown that long non-coding RNAs (lncRNAs) play an important role in the development of cancer. By using the next generation HiSeq sequencing assay, we determined lncRNAs exhibiting differential expression between DLBCL patients and healthy controls. Then, RT-qPCR was performed for identification in clinical samples and cell materials, and lncRNA PANDA was verified to be down-regulated in DLBCL patients and have considerable diagnostic potential. In addition, decreased serum PANDA level was correlated to poorer clinical outcome and lower overall survival in DLBCL patients. Subsequently, we determined the experimental role of lncRNA PANDA in DLBCL progression. Luciferase reporter assay and chromatin immunoprecipitation assay suggested that lncRNA PANDA was induced by p53 and p53 interacts with the promoter region of PANDA. Cell functional assay further indicated that PANDA functioned as a tumor suppressor gene through the suppression of cell growth by a G0/G1 cell cycle arrest in DLBCL. More importantly, Cignal Signal Transduction Reporter Array and western blot assay showed that lncRNA PANDA inactivated the MAPK/ERK signaling pathway. In conclusion, our integrated approach demonstrates that PANDA in DLBCL confers a tumor suppressive function through inhibiting cell proliferation and silencing MAPK/ERK signaling pathway. Thus, PANDA may be a promising therapeutic target for patients with DLBCL.

Two novel p38 MAPKs identified from Epinephelus coioides and their expression pattern in response to Cryptocaryon irritans infection

P38 mitogen-activated protein kinases (MAPKs) are one of the most important central regulatory proteins response to extra environmental stresses. In this study, two novel p38 MAPKs, Ec-P38γ and Ec-P38δ, were identified from Epinephelus coioides, an economically important cultured fish in China and Southeast Asian counties. Both of Ec-p38γ and Ec-p38δ sequences contain a serine/threonine protein kinase (S_TKc) domain and a highly conserved Thr-Gly-Tyr (TGY) motif. Analysis of phylogenetic relationships illustrated that p38 amino acid sequences were conserved between different species indicating that the functions may be similar. The four subtypes of p38 (α, β, γ, and δ) mRNA can be detected in all thirteen tissues examined, but the expression level is different in these tissues. The expression patterns of the four Ec-p38 subtypes in E. coioides were also detected response to Cryptocaryon irritans infection, one of the most important protozoan pathogens of marine fish. The expression of four p38 subtypes was up-regulated in the tissues examined, with the highest expressions of Ec-p38α (5.2 times) and Ec-p38δ (4.2 times) occurring in the skin, while Ec-p38β (24.8 times) and γ (16.6 times) occurred in the spleen. There was no significantly correlation between the expression of Ec-p38γ/Ec-p38δ and the expression of nuclear factor kappaB (NF-kB). The results indicated the sequences and the characters of Ec-p38γ and Ec-p38δ were conserved, the p38 subtypes showed tissue-specific expression patterns in healthy grouper, and their expressions were significantly up-regulated post C. irritans infection, suggesting these p38 MAPKs may play important roles in these tissues during pathogen-caused inflammation.

Regulation of glucose uptake in lymphoma cell lines by c-MYC- and PI3K-dependent signaling pathways and impact of glycolytic pathways on cell viability

BACKGROUND

Changes in glucose and energy metabolism contribute to the altered phenotype of cancer cells and are the basis for positron emission tomography with ¹⁸F-fluoro-2-deoxy-D-glucose (FDG) to visualize tumors in vivo. The molecular background of the enhanced glucose uptake and its regulation in lymphoma cells is not fully clarified and may provide new possibilities to reverse the altered metabolism. Thus in this study we investigated regulation of glucose uptake by different signaling pathways. Furthermore, the effect of the glucose analog 2-deoxy-D-glucose (2-DG) alone and in combination with other inhibitors on cell survival was studied.

METHODS

An FDG uptake assay was established and uptake of FDG by lymphoma cells was determined after incubation with inhibitors of the c-MYC and the PI3K signalling pathways that are known to be activated in lymphoma cells and able to regulate glucose metabolism. Inhibitors of MAPK signalling pathways whose role in altered metabolism is still unclear were also investigated. Expression of mRNAs of the glucose transporter 1 (GLUT1), hexokinase 2 (HK2), glucose-6-phosphatase (G6Pase) and lactate dehydrogenase A (LDHA) and of the glucose metabolism-regulating micro RNAs (miRNA) miR21, -23a, -133a, -133b, -138-1 and -143 was determined by RT-PCR. Cell viability was analysed by MTT assay.

RESULTS

Treatment with the c-MYC inhibitor 10058-F4 and inhibitors of the PI3K/mTOR pathway diminished uptake of FDG in all three cell lines, while inhibition of MAPK pathways had no effect on glucose uptake. Expression of glycolysis-related genes and miRNAs were diminished, although to a variable degree in the three cell lines. The c-MYC inhibitor, the PI3K inhibitor LY294002, the mTOR inhibitor Rapamycin and 2-DG all diminished the number of viable cells. Interestingly, in combination with 2-DG, the c-MYC inhibitor, LY294002 and the p38 MAPK inhibitor SB203580 had synergistic effects on cell viability in all three cell lines.

CONCLUSIONS

c-MYC- and PI3K/mTOR-inhibitors decreased viability of the lymphoma cells and led to decreased glucose uptake, expression of glycolysis-associated genes, and glucose metabolism-regulating miRNAs. Inhibition of HK by 2-DG reduced cell numbers as a single agent and synergistically with inhibitors of other intracellular pathways. Thus, targeted inhibition of the pathways investigated here could be a strategy to suppress the glycolytic phenotype of lymphoma cells and reduce proliferation.

ZLD1122, a novel EZH2 and EZH1 small molecular inhibitor, blocks H3K27 methylation and diffuse large B cell lymphoma cell growth

Here, we reported a novel, selective, small-molecule inhibitor of EZH2 and EZH1 synthesized by us, ZLD1122, which inhibited both EZH1 and wild type and mutant EZH2 activities with nanomolar potency.