Inhibition of ZEB1 by miR-200 characterizes Helicobacter pylori-positive gastric diffuse large B-cell lymphoma with a less aggressive behavior

Molecular Mechanisms and Treatment Strategies for Helicobacter pylori-Induced Gastric Carcinogenesis and Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma

Helicobacter pylori has been classified as a class I carcinogen by WHO because of its primary involvement in the development of gastric cancer and mucosa-associated lymphoid tissue (MALT) lymphoma. This review focuses on understanding the molecular pathophysiological mechanisms that operate within intracellular transduction pathways and their relevance in the treatment strategies for the two main diseases caused by H. pylori. H. pylori virulence factors such as cytotoxin-associated gene A and vacuolating cytotoxin A genotypes, inflammatory mediators, H. pylori-induced microRNA deregulation, alterations in autophagy proteins and regulators, and changes in DNA methylation are some of the molecular mechanisms that play essential roles in H. pylori infection and gastric carcinogenesis. The discovery of novel treatment strategies that target the deregulated intracellular transduction pathways in gastric carcinogenesis and MALT lymphoma is critical. H. pylori eradication (HPE) is not limited to H. pylori-dependent low-grade MALT lymphoma and may be used in patients with high-grade diffuse large B-cell lymphoma (DLBCL) (de novo or DLBCL-MALT lymphoma). The loss of H. pylori dependency and high-grade transformation appear to be distinct events in the progression of gastric lymphoma. Interestingly, patients with H. pylori-positive gastric DLBCL without histological evidence of MALT lymphoma (pure gastric DLBCL) may respond to HPE therapy.

Outcome and patterns of relapse in primary gastric diffuse large B cell lymphoma treated with RCHOP

OBJECTIVES

Patterns and predictors of relapse in primary gastric diffuse large B cell lymphoma (DLBCL) were variably reported. Our study aims to evaluate the patterns and predictors of relapse in early-stage gastric DLBCL treated with Rituximab, Cyclophosphamide, Doxorubicin, Vincristine, and Prednisolone (RCHOP).

METHODS

From 2005 to 2019, the medical records of 72 patients with stage I or stage II gastric DLBCL treated with six cycles of RCHOP without radiotherapy were reviewed. Different variables were correlated with progression free survival (PFS), overall survival (OS), and local relapse free survival (LRFS).

RESULTS

64 (88.1%) patients achieved a complete response (CR), while 8 (11.9%) had refractory disease. After CR, 9 (14%) patients relapsed; 7 (78%) relapses were loco-regional. Abnormal LDH (p = 0.028), H. pylori negative (p = 0.032) and, stage adjusted international prognostic index (sa-IPI) > 1 (p = 0.013) correlated with loco-regional failure. The 5-year PFS, OS, and LRFS were 74.8%, 75.3%, and 87.5%, respectively, after a median follow-up of 58 (range: 6-185) months. The median time to progression or relapse was 9 months (range: 5-54 months). In multivariate analysis, a sa-IPI >1 (HR: 3.56, CI: 1.35-8.8, p = 0.01) was associated with PFS while low albumin (HR: 8.85, CI: 1.09-71.4, p = 0.041) was associated with worse OS. None of the variables were associated with LRFS.

CONCLUSION

Treatment of primary gastric DLBCL with RCHOP results in a high CR rate. The majority of treatment failures were loco-regional. Sa-IPI and H. pylori status may be used to identify patients who may benefit from combined modality treatment.

Using the Precision Lasso for gene selection in diffuse large B cell lymphoma cancer

BACKGROUND

Gene selection from gene expression profiles is the appropriate tool for diagnosing and predicting cancers. The aim of this study is to perform a Precision Lasso regression model on gene expression of diffuse large B cell lymphoma patients and to find marker genes related to DLBCL.

METHODS

In the present case-control study, the dataset included 180 gene expressions from 14 healthy individuals and 17 DLBCL patients. The marker genes were selected by fitting Ridge, Lasso, Elastic Net, and Precision Lasso regression models.

RESULTS

Based on our findings, the Precision Lasso, the Ridge, the Elastic Net, and the Lasso models choose the most marker genes, respectively. In addition, the top 20 genes are based on models compared with the results of clinical studies. The Precision Lasso and the Ridge models selected the most common genes with the clinical results, respectively.

CONCLUSIONS

The performance of the Precision Lasso model in selecting related genes could be considered more acceptable rather than other models.

Multi-platform profiling characterizes molecular subgroups and resistance networks in chronic lymphocytic leukemia

Knowledge of the genomic landscape of chronic lymphocytic leukemia (CLL) grows increasingly detailed, providing challenges in contextualizing the accumulated information. To define the underlying networks, we here perform a multi-platform molecular characterization. We identify major subgroups characterized by genomic instability (GI) or activation of epithelial-mesenchymal-transition (EMT)-like programs, which subdivide into non-inflammatory and inflammatory subtypes. GI CLL exhibit disruption of genome integrity, DNA-damage response and are associated with mutagenesis mediated through activation-induced cytidine deaminase or defective mismatch repair. TP53 wild-type and mutated/deleted cases constitute a transcriptionally uniform entity in GI CLL and show similarly poor progression-free survival at relapse. EMT-like CLL exhibit high genomic stability, reduced benefit from the addition of rituximab and EMT-like differentiation is inhibited by induction of DNA damage. This work extends the perspective on CLL biology and risk categories in TP53 wild-type CLL. Furthermore, molecular targets identified within each subgroup provide opportunities for new treatment approaches.

MicroRNAs and Their Influence on the ZEB Family: Mechanistic Aspects and Therapeutic Applications in Cancer Therapy

Molecular signaling pathways involved in cancer have been intensively studied due to their crucial role in cancer cell growth and dissemination. Among them, zinc finger E-box binding homeobox-1 (ZEB1) and -2 (ZEB2) are molecules that play vital roles in signaling pathways to ensure the survival of tumor cells, particularly through enhancing cell proliferation, promoting cell migration and invasion, and triggering drug resistance. Importantly, ZEB proteins are regulated by microRNAs (miRs). In this review, we demonstrate the impact that miRs have on cancer therapy, through their targeting of ZEB proteins. MiRs are able to act as onco-suppressor factors and inhibit the malignancy of tumor cells through ZEB1/2 down-regulation. This can lead to an inhibition of epithelial-mesenchymal transition (EMT) mechanism, therefore reducing metastasis. Additionally, miRs are able to inhibit ZEB1/2-mediated drug resistance and immunosuppression. Additionally, we explore the upstream modulators of miRs such as long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), as these regulators can influence the inhibitory effect of miRs on ZEB proteins and cancer progression.

Prognostic significance of helicobacter pylori-infection in gastric diffuse large B-cell lymphoma

Background

Helicobacter pylori (H. pylori) is thought to have an oncogenic effect on the development of gastric malignancies. However, the effect of H. pylori status on the prognosis of gastric diffuse large B-cell lymphoma (DLBCL) remains unconfirmed. This study aimed to identify the prognostic importance of H. pylori infection in de novo gastric DLBCL.

Methods

One hundred and twenty-nine patients diagnosed with primary de novo gastric DLBCL at the West China Hospital of Sichuan University from 1st January 2009 to 31st May 2016 were included. The clinical features of the patients were documented. H. pylori status was assessed via urease breath tests and histologic examinations. The prognostic value of H. pylori was verified via univariate and multivariate analyses.

Results

Over a median follow-up of 52.2 months (range 4–116), the 5-year overall survival (OS) for all patients was 78.7%. Patients with H. pylori infections had significantly better 5-year PFS and OS than did the H. pylori-negative subgroup (5-year PFS, 89.3% vs. 74.1%, P = 0.040; 5-year OS, 89.7% vs. 71.8%, P = 0.033). Negative H. pylori status and poor ECOG performance were independent negative prognostic indicators for both PFS and OS (PFS, P = 0.045 and P = 0.001, respectively; OS, P = 0.021 and P < 0.001, respectively).

Conclusions

H. pylori status in de novo gastric DLBCL can be a promising predictor of disease outcome, and patients with negative H. pylori status require careful follow-up since they tend to have a worse outlook.

ZEB Proteins in Leukemia: Friends, Foes, or Friendly Foes?

ZEB1 and ZEB2 play pivotal roles in solid cancer metastasis by allowing cancer cells to invade and disseminate through the transcriptional regulation of epithelial-to-mesenchymal transition. ZEB expression is also associated with the acquisition of cancer stem cell properties and therapy resistance. Consequently, expression levels of ZEB1/2 and of their direct target genes are widely seen as reliable prognostic markers for solid tumor aggressiveness and cancer patient outcome.

Recent loss-of-function mouse models demonstrated that both ZEBs are also essential hematopoietic transcription factors governing blood lineage commitment and fidelity. Interestingly, both gain- and loss-of-function mutations have been reported in multiple hematological malignancies. Combined with emerging functional studies, these data suggest that ZEB1 and ZEB2 can act as tumor suppressors and/or oncogenes in blood borne malignancies, depending on the cellular context. Here, we review these novel insights and discuss how balanced expression of ZEB proteins may be essential to safeguard the functionality of the immune system and prevent leukemia.

Role of miR200b-5p miRNA in lymphomagenesis associated with Sjögren's syndrome (SS)

Background:

Development of non-Hodgkin’s lymphoma (NHL) is the major adverse outcome of primary Sjögren’s Syndrome (pSS) affecting both morbidity and mortality. The high frequency of transformation to lymphoid malignancy in pSS among autoimmune rheumatic diseases (6–10% of patients) and the accessibility of the affected organ (minor salivary glands; MSG), render pSS an ideal model for the study of lymphomagenesis associated with autoimmune diseases and inflammation. Although pSS-related lymphoid transformation is generally considered as an antigen-driven, multi-step process owed to the chronic activation of B-cells in MSGs, the underlying mechanisms remain elusive. Our recent results support that miR200b-5p miRNA is significantly down-regulated in the MSGs of pSS patients who have or will develop lymphoma, long before lymphoma clinical onset, indicating that it may be involved in lymphomagenesis.

Aim:

To investigate the role of miR200b-5p miRNA in pSS-associated lymphomagenesis.

Methods:

At first, the miR200b-5p-expression will be examined by in situ hybridization in MSGs of pSS patients who are at low risk and have not developed NHL during follow-up, high risk and developed NHL in the future (pre-lymphoma) or have NHL, and the expressing cellular types, as well as those with reduced expression during lymphomagenesis, will be identified. Then, the miR200b-5p targeted molecular pathways in those cellular types (epithelial, B-cells and/or other lymphocytes, all non-neoplastic) will be studied in in vitro experiments by over-expressing and silencing of miR200b-5p, followed by transcriptome analysis. This approach is expected to find possibly novel pathogenetic mechanisms underlying SS-related lymphomagenesis. The latter is of high significance, not only for the understanding of lymphomagenesis, but also for its reversal and/or treatment.

Anticipated Benefits:

This approach is anticipated to a) reveal the differentially regulated molecules and pathways by miR200b-5p, b) enlighten novel pathogenetic pathways underlying lymphomagenesis and c) identify novel therapeutic targets and possibly evidence-based therapeutic interventions.

Clinical manifestations and epigenetic mechanisms of gastric mucosa associated lymphoid tissue lymphoma and long-term follow-up following Helicobacter pylori eradication

The current study aimed to summarize the clinical manifestations and identify the epigenetic mechanisms of gastric mucosa associated lymphoid tissue (MALT) lymphoma, as well as evaluate the long-term effects of Helicobacter pylori (H. pylori) eradication. A total of 122 patients with marginal zone B-cell lymphoma of primary gastric MALT lymphoma were enrolled in the present study. The clinical manifestations of gastric MALT lymphoma, including symptoms, H. pylori state and endoscopic type, were summarized. The response to therapy was evaluated in patients that underwent H. pylori eradication. Survival analysis was estimated using the Kaplan-Meier method. The expression of microRNA-383 (miR-383) in tumor tissues and cell lines was determined using reverse transcription quantitative polymerase chain reaction. Furthermore, bioinformatic analyses, luciferase reporter assays. and western blot analysis identified zinc finger E-box binding homeobox 2 (ZEB2) as a direct target gene of miR-383. An MTT assay was used to examine the function of miR-383 and ZEB2 in MALT lymphoma. The clinical symptoms of patients with gastric MALT lymphoma were non-specific and included epigastric pain, abdominal discomfort and bleeding. The majority of endoscopic types were classified as ulcer, erosion and mucosa edema. The H. pylori infection rate was 79.5% (97/122) and a total of 47 patients underwent eradication therapy. Lymphoma remission was achieved in 93.6% (44/47) of patients and complete remission (CR) was achieved in 74.4% (35/47). The median follow-up time was 38 months (range, 10-132 months) and the median time taken to achieve CR was 4 months (range, 3-7 months). The estimated 3-year survival rate was 90.3% and the 5-year survival rate was 76.2%. Therefore, it was determined that patients with stage I or II gastric MALT lymphoma are able to undergo H. pylori eradication as a first-line treatment and that the survival rate of patients undergoing this treatment is high. Furthermore, it was determined that the mechanism by which miR-383 and ZEB2 contribute to MALT lymphoma progression is by the targeting of ZEB2 by miR-383, which inhibits the proliferation of cancer cells.

Identification of microRNAs implicated in the late differentiation stages of normal B cells suggests a central role for miRNA targets ZEB1 and TP53

In the late B cell differentiation stages, miRNAs expression modifications promoting or inhibiting key pathways are only partially defined. We isolated 29 CD19⁺ human B cell samples at different stages of differentiation: B cells from peripheral blood; naïve, germinal center (GC) and subepithelial (SE) B cells from tonsils. SE cells were further split in activated and resting B cell. The miRNA expression profile of these B cells was assessed by microarray analysis and selected miRNAs were validated by quantitative RT-PCR and in situ hybridization on normal tonsils. The comparison of all samples showed changes in 107 miRNAs in total. Among 48 miRNAs differentially expressed in naïve, GC and SE cells, we identified 8 miRNAs: mir-323, mir-138, mir-9*, mir-211, mir-149, mir-373, mir-135a and mir-184, strictly specific to follicular cells that had never been implicated before in late stages of B cell development. Moreover, we unveiled 34 miRNAs able to discriminate between CD5⁻ activated B cells and resting B cells. The miRNAs profile of CD5⁻ resting B cells showed a higher similarity to naïve CD5⁺ than CD5⁻ activated B cells. Finally, network analysis on shortest paths connecting gene targets suggested ZEB1 and TP53 as key miRNA targets during the follicular differentiation pathway. These data confirm and extend our knowledge on the miRNAs-related regulatory pathways involved in the late B cell maturation.

MicroRNA mediated regulation of immunity against gram-negative bacteria

Evidence over the last couple decades has comprehensively established that short, highly conserved, non-coding RNA species called microRNA (miRNA) exhibit the ability to regulate expression and function of host genes at the messenger RNA (mRNA) level. MicroRNAs play key regulatory roles in immune cell development, differentiation, and protective function. Intrinsic host immune response to invading pathogens rely on intricate orchestrated events in the development of innate and adaptive arms of immunity. We discuss the involvement of miRNAs in regulating these processes against gram negative pathogens in this review.

miRNAs in Normal and Malignant Hematopoiesis

Lineage specification is primarily regulated at the transcriptional level and lineage-specific transcription factors determine cell fates. MicroRNAs (miRNAs) are 18–24 nucleotide-long non-coding RNAs that post-transcriptionally decrease the translation of target mRNAs and are essential for many cellular functions. miRNAs also regulate lineage specification during hematopoiesis. This review highlights the roles of miRNAs in B-cell development and malignancies, and discusses how miRNA expression profiles correlate with disease prognoses and phenotypes. We also discuss the potential for miRNAs as therapeutic targets and diagnostic tools for B-cell malignancies.

EMT- and MET-related processes in nonepithelial tumors: importance for disease progression, prognosis, and therapeutic opportunities

The epithelial-to mesenchymal (EMT) process is increasingly recognized for playing a key role in the progression, dissemination, and therapy resistance of epithelial tumors. Accumulating evidence suggests that EMT inducers also lead to a gain in mesenchymal properties and promote malignancy of nonepithelial tumors. In this review, we present and discuss current findings, illustrating the importance of EMT inducers in tumors originating from nonepithelial/mesenchymal tissues, including brain tumors, hematopoietic malignancies, and sarcomas. Among these tumors, the involvement of mesenchymal transition has been most extensively investigated in glioblastoma, providing proof for cell autonomous and microenvironment-derived stimuli that provoke EMT-like processes that regulate stem cell, invasive, and immunogenic properties as well as therapy resistance. The involvement of prominent EMT transcription factor families, such as TWIST, SNAI, and ZEB, in promoting therapy resistance and tumor aggressiveness has also been reported in lymphomas, leukemias, and sarcomas. A reverse process, resembling mesenchymal-to-epithelial transition (MET), seems particularly relevant for sarcomas, where (partial) epithelial differentiation is linked to less aggressive tumors and a better patient prognosis. Overall, a hybrid model in which more stable epithelial and mesenchymal intermediates exist likely extends to the biology of tumors originating from sources other than the epithelium. Deeper investigation and understanding of the EMT/MET machinery in nonepithelial tumors will shed light on the pathogenesis of these tumors, potentially paving the way toward the identification of clinically relevant biomarkers for prognosis and future therapeutic targets.

Status of Epstein-Barr Virus Coinfection with Helicobacter pylori in Gastric Cancer

Epstein-Barr virus is a ubiquitous human herpesvirus whose primary infection causes mononucleosis, Burkett's lymphoma, nasopharyngeal carcinoma, autoimmune diseases, and gastric cancer (GC). The persistent infection causes malignancies in lymph and epithelial cells. Helicobacter pylori causes gastritis in human with chronic inflammation. This chronic inflammation is thought to be the cause of genomic instability. About 45%-word population have a probability of having both pathogens, namely, H. pylori and EBV. Approximately 180 per hundred thousand population is developing GC along with many gastric abnormalities. This makes GC the third leading cause of cancer-related death worldwide. Although lots of research are carried out individually for EBV and H. pylori, still there are very few reports available on coinfection of both pathogens. Recent studies suggested that EBV and H. pylori coinfection increases the occurrence of GC as well as the early age of GC detection comparing to individual infection. The aim of this review is to present status on coinfection of both pathogens and their association with GC.

Relationship between gastrointestinal micro-ecological imbalance and development of gastric cancer

The human body and microorganisms present in the body form a symbiotic system as the relationship between eukaryotes and prokaryotes. Therefore, it is not enough to study human diseases only in terms of human body. Recent studies have pointed out that microorganisms are involved in the occurrence of a large number of malignant tumors. According to a conservative estimate, at least 15% of cancer cases are associated with infectious agents. Gastric cancer is the second major cause of global cancer deaths. For a long period of time, researchers believe that Helicobacter pylori associated with chronic gastritis is the strongest risk factor for the occurrence of gastric cancer. However, with the progress of molecular biology research, it has been found that there is a close interaction between the large microbial flora and Helicobacter pylori in the gastrointestinal tract. The changes of microbial community composition have important effects on the formation, development and intervention of gastric cancer. This article will review the occurrence and development of gastrointestinal microorganism and gastric cancer.

miR-128 modulates chemosensitivity and invasion of prostate cancer cells through targeting ZEB1

OBJECTIVE

Recent reports strongly suggest the profound role of miRNAs in cancer therapeutic response and progression, including invasion and metastasis. The sensitivity to therapy and invasion is the major obstacle for successful treatment in prostate cancer. We aimed to investigate the regulative effect of miR-128/zinc-finger E-box-binding homeobox 1 axis on prostate cancer cell chemosensitivity and invasion.

METHODS

The miR-128 expression pattern of prostate cancer cell lines and tissues was detected by real-time reverse transcriptase-polymerase chain reaction, while the mRNA and protein expression levels of zinc-finger E-box-binding homeobox 1 were measured by real-time reverse transcriptase-polymerase chain reaction and western blot assay, respectively. Dual-luciferase reporter gene assay was used to find the direct target of miR-128. Furthermore, prostate cancer cells were treated with miR-128 mimic or zinc-finger E-box-binding homeobox 1-siRNA, and then the cells' chemosensitivity and invasion were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and transwell assay, respectively.

RESULTS

We found miR-128 expression obviously decreased in prostate cancer tissues compared with paired normal tissues. Restored miR-128 expression sensitized prostate cancer cells to cisplatin and inhibited the invasion. Furthermore, there was an inverse expression pattern between miR-128 and zinc-finger E-box-binding homeobox 1 in prostate cancer cells and tissues, and zinc-finger E-box-binding homeobox 1 was identified as a direct target of miR-128 in prostate cancer. Knockdown of zinc-finger E-box-binding homeobox 1 expression efficiently sensitized prostate cancer cells to cisplatin and inhibited the invasion. However, ectopic zinc-finger E-box-binding homeobox 1 expression impaired the effects of miR-128 on chemosensitivity and invasion in prostate cancer cells.

CONCLUSIONS

miR-128 functions as a potential cancer suppressor in prostate cancer progression and rational therapeutic strategies for prostate cancer would be developed based on miR-128/zinc-finger E-box-binding homeobox 1 axis.

Comprehensive miRNA sequence analysis reveals survival differences in diffuse large B-cell lymphoma patients

Background

Diffuse large B-cell lymphoma (DLBCL) is an aggressive disease, with 30% to 40% of patients failing to be cured with available primary therapy. microRNAs (miRNAs) are RNA molecules that attenuate expression of their mRNA targets. To characterize the DLBCL miRNome, we sequenced miRNAs from 92 DLBCL and 15 benign centroblast fresh frozen samples and from 140 DLBCL formalin-fixed, paraffin-embedded tissue samples for validation.

Results

We identify known and candidate novel miRNAs, 25 of which are associated with survival independently of cell-of-origin and International Prognostic Index scores, which are established indicators of outcome. Of these 25 miRNAs, six miRNAs are significantly associated with survival in our validation cohort. Abundant expression of miR-28-5p, miR-214-5p, miR-339-3p, and miR-5586-5p is associated with superior outcome, while abundant expression of miR-324-5p and NOVELM00203M is associated with inferior outcome. Comparison of DLBCL miRNA-seq expression profiles with those from other cancer types identifies miRNAs that were more abundant in B-cell contexts. Unsupervised clustering of miRNAs identifies two clusters of patients that have distinct differences in their outcomes. Our integrative miRNA and mRNA expression analyses reveal that miRNAs increased in abundance in DLBCL appear to regulate the expression of genes involved in metabolism, cell cycle, and protein modification. Additionally, these miRNAs, including one candidate novel miRNA, miR-10393-3p, appear to target chromatin modification genes that are frequent targets of somatic mutation in non-Hodgkin lymphomas.

Conclusions

Our comprehensive sequence analysis of the DLBCL miRNome identifies candidate novel miRNAs and miRNAs associated with survival, reinforces results from previous mutational analyses, and reveals regulatory networks of significance for lymphomagenesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13059-014-0568-y) contains supplementary material, which is available to authorized users.