Clinical Features,Treatment and Outcome of Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma of the Ocular Adnexa: Single Center Experience of 60 Patients

Background

Orbital marginal zone B-cell lymphoma (OAML) constitutes for the most frequent diagnosis in orbital lymphoma. Relatively little data, however, have been reported in larger cohorts of patients staged in a uniform way and no therapy standard exists to date.

Material and Methods

We have retrospectively analyzed 60 patients diagnosed and treated at our institution 1999–2012. Median age at diagnosis was 64 years (IQR 51–75) and follow-up time 43 months (IQR 16–92). All patients had undergone uniform extensive staging and histological diagnosis was made by a reference pathologist according to the WHO classification.

Results

The majority of patients presented with stage IE (n = 40/60, 67%), three had IIE/IIIE and the remaining 17 stage IVE. Seven patients with IVE had bilateral orbital disease whereas the others showed involvement of further organs. Treatment data were available in 58 patients. Local treatment with radiotherapy (14/58, 24%) or surgery (3/58, 5%) resulted in response in 82% of patients. A total of 26 patients (45%) received systemic treatment with a response rate of 85%. Nine patients received antibiotics as initial therapy; response rate was 38%. Watchful-waiting was the initial approach in 6/58 patients. In total 28/58 patients (48%) progressed and were given further therapy. Median time-to-progression in this cohort was 20 months (IQR 9–39). There was no difference in time-to-progression after first-line therapy between the different therapy arms (p = 0.14). Elevated beta-2-microglobulin, plasmacytic differentiation, autoimmune disorder and site of lymphoma were not associated with a higher risk for progress.

Conclusion

Our data underscore the excellent prognosis of OAML irrespective of initial therapy, as there was no significant difference in time-to-progression and response between local or systemic therapy. In the absence of randomized trials, the least toxic individual approach should be chosen for OAML.     

miR-142-3p/5p role in cancer: From epigenetic regulation to immunomodulation

MicroRNAs (miRNAs) play critical roles in cancer pathobiology, acting as regulators of gene expression and pivotal drivers of tumorigenesis. It is believed that miRNAs act through canonical mechanisms, involving the binding of mature miRNAs to target messenger RNAs (mRNAs) and subsequent repression of protein translation or degradation of target mRNAs. miR-142-3p/5p has been extensively studied and established as a key regulator in various malignancies. Recent discoveries have revealed miR-142-3p/5p serve as either oncogene or tumor suppressor in cancer. By targeting epigenetic factor and cancer-related signaling pathway, miR-142-3p/5p can regulate wide range of downstream genes. The immune modulatory role of miR-142-3p/5p has been shown in various cancers, which provides significant insight into immunosuppression and tumor escape from the immune response. Exosomes with miR-142-3p/5p facilitate cell communication and can affect cancer cell behavior, offering potential therapeutic, and diagnosis applications in cancer therapy. In this review, for the first time, we comprehensively summarize the current knowledge regarding mentioned functions of miR-142-3p/5p in cancer pathobiology.     

BCL10GFP fusion protein as a substrate for analysis of determinants required for Mucosa-Associated Lymphoid Tissue 1 (MALT1)-mediated cleavage

Background

MALT1 belongs to a family of paracaspase and modulates NF-κB signaling pathways through its scaffolding function and proteolytic activity. MALT1 cleaves protein substrates after a positively charged Arginine residue. BCL10, a 233 amino acids polypeptide, is identified as one of the MALT1 proteolytic substrates. MALT1 cleaves BCL10 at the C-terminal end of Arg228. A mere 5 amino acids difference between the substrate and the proteolytic product made it difficult to tell whether the cleavage event took place by using a simple western blot analysis. Here, BCL10GFP was constructed and utilized to examine the specificity and domain determinants for MALT1 cleavage in cells.

Methods

Various BCL10GFP constructs were transfected into HEK293T cell with MALT1 construct by using calcium phosphate-DNA precipitation method. Lysates of transfectants were resolved by SDS/PAGE and analyzed by western blot analysis.

Results

BCL10GFP was proteolytically processed by MALT1 as BCL10. The integrity of caspase recruitment domain (CARD) and MALT1-interacting domain on BCL10 were required for MALT1 proteolytic activity. Besides the invariant P1 cleavage site Arg228, P4 Leu225 played a role in defining BCL10 as a good substrate for MALT1.

Conclusions

We offered a way of monitoring the catalytic activity of MALT1 in HEK293T cells using BCL10GFP as a substrate. BCL10GFP can be utilized as a convenient tool for studying the determinants for efficient MALT1 cleavage in HEK293T cells     

Acute Stressor Exposure Modifies Plasma Exosome-Associated Heat Shock Protein 72 (Hsp72) and microRNA (miR-142-5p and miR-203)

Exosomes, biologically active nanoparticles (40–100 nm) released by hematopoietic and non-hematopoietic cells, contain a variety of proteins and small, non-coding RNA known as microRNA (miRNA). Exposure to various pathogens and disease states modifies the composition and function of exosomes, but there are no studies examining invivo exosomal changes evoked by the acute stress response. The present study reveals that exposing male Fisher 344 rats to an acute stressor modulates the protein and miRNA profile of circulating plasma exosomes, specifically increasing surface heat shock protein 72 (Hsp72) and decreasing miR-142-5p and -203. The selected miRNAs and Hsp72 are associated with immunomodulatory functions and are likely a critical component of stress-evoked modulation of immunity. Further, we demonstrate that some of these stress-induced modifications in plasma exosomes are mediated by sympathetic nervous system (SNS) activation of alpha-1 adrenergic receptors (ADRs), since drug-mediated blockade of the receptors significantly attenuates the stress-induced modifications of exosomal Hsp72 and miR-142-5p. Together, these findings demonstrate that activation of the acute stress response modifies the proteomic and miRNA profile of exosomes released into the circulation.     

Helicobacter pylori (H. pylori) molecular signature in conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma

Conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma is an extranodal marginal zone B-cell lymphoma that is characterized by an exaggerated clonal expansion of B cells, which implicate a pathological proliferative response to antigen(s) including bacteria. Helicobacter pylori (H. pylori) infection is recognized as one of the causative agents of gastric MALT lymphoma; however, it has not been reported in extra gastric MALT lymphoma. We studied 5 patients (4 adults and 1 child) with salmon-colored conjunctival lesions. One patient also had a history of abnormal bone marrow biopsy a year earlier with lymphoid aggregates involving 5% of the overall bone marrow. The conjunctival lesions of the 5 patients were biopsied. Histopathological diagnoses were consistent with conjunctival MALT lymphoma. Lymphoma and normal conjunctival cells were microdissected using laser capture microscopy or manual techniques. DNA was extracted and subjected to PCR amplification using H. pylori gene-specific primers from the urease B and vac/m2 gene. Cells from chronic conjunctivitis (normal lymphocytes), conjunctival human T-cell lymphotropic virus type-1/adult T-cell leukemia/lymphoma (HTLV-1/ATL), and orbital B-cell lymphoma were also microdissected, processed and analyzed. PCR amplification and Southern blot hybridization demonstrated H. pylori DNA in the conjunctival MALT lymphoma cells of 4/5 cases. The negative case was the one with a history of abnormal bone marrow. In contrast, H. pylori gene was not detected in normal conjunctival cells from the cases of MALT lymphoma or the lymphocytes, ATL and orbital B-lymphoma cells from the controls. These data suggest that H. pylori may play a role in conjunctival MALT lymphoma.     

MiR-142-5p and miR-486-5p as biomarkers for early detection of chronic antibody-mediated rejection in kidney transplantation

De novo donor-specific HLA antibody (DSA) would not necessarily contribute to chronic antibody-mediated rejection (CAMR) in kidney transplantation. Here, we investigated whether PBMC miRNAs could be predictable biomarkers for CAMR. Microarray profiling of 435 mature miRNAs in pooled samples was conducted. Individual analysis revealed that miR-142-5p was significantly (p?<?0.01) underexpressed in patients with DSA. After DSA production, miR-486-5p and its target PTEN/foxO3 mRNA were significantly overexpressed (p?<?0.01) and underexpressed (p?<?0.01), respectively, in patients with biopsy-proven CAMR, compared with non-CAMR. Our studies suggest that miRNA expression patterns may serve as noninvasive diagnostic biomarkers to evaluate immune response and kidney allograft status.     

Cost-Effectiveness of Eradication of Helicobacter pylori in Gastric Cancer Survivors After Endoscopic Resection of Early Gastric Cancer

Background:  Clinical effectiveness of Helicobacter pylori eradication in gastric cancer survivors after endoscopic resection of early gastric cancer (EGC) was recently established in a randomized controlled trial. We aimed to establish long-term cost-effectiveness in gastric cancer survivors after endoscopic resection of EGC.
Materials and Methods:  A Markov model was constructed to compare the costs and outcomes of the two intervention strategies: (1) eradicate H. pylori after complete resection of EGC by endoscopy (2) do not eradicate. Estimates for variables in the model were obtained by extensive review of published reports. Analyses were made from the Korean public healthcare provider's perspective.
Results:  Base-case analysis indicated H. pylori eradication costs less (US$ 29,780 vs. US$ 30,594) than no eradication, and save more lives (mean life expectancy from eradication: 13.60 years vs. 13.55 years). One-way and three-way sensitivity analyses showed the robustness of the cost-effectiveness results.
Conclusion:  In this selective population with very high risk of developing gastric cancer, H. pylori eradication should be considered for reimbursement with priority to prevent subsequent cancer and also reduce health care cost.     

Expression and Prognostic Value of miR-486-5p in Patients with Gastric Adenocarcinoma

MicroRNA (miR)-486-5p expression is often reduced in human cancers. However, its expression in gastric carcinoma and its relation to clinicopathological features and prognosis are unclear. Tissue microarrays were constructed from 84 patients with gastric adenocarcinoma (GC) who were undergoing radical resection. miR-486-5p expression was detected by miRNA-locked nucleic acid in situ hybridization, and its correlations with clinicopathological features and overall survival were analyzed. Bioinformatic studies predict that fibroblast growth factor 9 (FGF9) is a potential target gene of miR-486-5p. miR-486-5p was mainly located in the cytoplasm of GC cells and neighboring normal tissues. Compared with paracancerous normal tissue, miR-486-5p expression was decreased in 63.1% (53/84) of the GC samples, increased in 32.1% (27/84) and unchanged in 4.8% (4/84). FGF9 expression was decreased in 69.0% (58/84) of GC samples and increased in 31.0% (26/84) compared with normal paracancerous tissues using immunohistochemical analysis. Low or unchanged miR-486-5p expression (P = 0.002), tumor stage (P = 0.001), tumor status (P = 0.001), node status (P = 0.001), tumor size (P = 0.004), and depth of tumor invasion (P = 0.013) were significant negative prognostic predictors for overall survival in patients with GC. After stratification according to American Joint Committee on Cancer (AJCC) stage, low/unchanged miR-486-5p expression remained a significant predictor of poor survival in stage II (P = 0.024) and stage III (P = 0.003). Cox regression analysis identified the following predictors of poor prognosis: tumor status (hazard ratio [HR], 7.19; 95% confidence interval [CI], 1.75–29.6; P = 0.006), stage (HR, 2.62; 95%CI, 1.50–4.59; P = 0.001), lymph node metastasis (HR, 2.52; 95% CI, 1.27–4.99; P = 0.008), low/unchanged miR-486-5p (HR, 2.47; 95% CI, 1.35–4.52; P = 0.003), high level of FGF9 (HR, 2.41; 95% CI, 1.42–4.09; P = 0.001) and tumor size (HR, 2.50; 95% CI, 1.30–4.82; P = 0.006). Low or unchanged expression of miR-486-5p compared with neighboring normal tissues was associated with a poor prognosis, while high expression was associated with a good prognosis in GC. miR-486-5p may thus be useful for evaluating prognosis and may provide a novel target treatment in patients with GC.     

miR-15a-5p和miR-16-5p在骨肉瘤组织中的表达分析

目的:使用microRNAs基因芯片及实时定量PCR法测定骨肉瘤组织中miR-15a-5p和miR-16-5p的相对表达含量,并与瘤旁组织对比,分析骨肉瘤细胞内miR-15a-5p和miR-16-5p的表达变化。方法:选取34例骨肉瘤组织蜡块样本,使用microRNAs基因芯片观察miR-15a-5p和miR-16-5p在骨肉瘤和瘤旁组织内的表达差异;实时定量PCR法测定骨肉瘤组织和瘤旁组织中miR-15a-5p和miR-16-5p的相对表达含量,并将两种结果对比分析。结果:microRNAs基因芯片结果显示,在骨肉瘤组织中,miR-15a-5p在肿瘤中的表达较瘤旁组织低1.79倍,miR-16-5p较瘤旁组织低1.62倍。实时定量PCR实验结果表明,miR-15a-5p和miR-16-5p表达较瘤旁组织降低,差异有统计学意义(P0.05)。经过统计学计算,miR-15a-5p在肿瘤中的表达较瘤旁组织低3.14倍,miR-16-5p较瘤旁组织低5.65倍。结论:在骨肉瘤中,miR-15a-5p和miR-16-5p表达含量降低,提示这两种microRNAs在骨肉瘤中可能做为抑癌因子存在。     

Exosomal miR-146a-5p and miR-155-5p promote CXCL12/CXCR7-induced metastasis of colorectal cancer by crosstalk with cancer-associated fibroblasts

C-X-C motif chemokine receptor 7 (CXCR7) is a newly discovered atypical chemokine receptor that binds to C-X-C motif chemokine ligand 12 (CXCL12) with higher affinity than CXCR4 and is associated with the metastasis of colorectal cancer (CRC). Cancer-associated fibroblasts (CAFs) have been known to promote tumor progression. However, whether CAFs are involved in CXCR7-mediated metastasis of CRC remains elusive. We found a significant positive correlation between CXCR7 expression and CAF activation markers in colonic tissues from clinical specimens and in villin-CXCR7 transgenic mice. RNA sequencing revealed a coordinated increase in the levels of miR-146a-5p and miR-155-5p in CXCR7-overexpressing CRC cells and their exosomes. Importantly, these CRC cell-derived miR-146a-5p and miR-155-5p could be uptaken by CAFs via exosomes and promote the activation of CAFs through JAK2–STAT3/NF-κB signaling by targeting suppressor of cytokine signaling 1 (SOCS1) and zinc finger and BTB domain containing 2 (ZBTB2). Reciprocally, activated CAFs further potently enhanced the invasive capacity of CRC cells. Mechanistically, CAFs transfected with miR-146a-5p and miR-155-5p exhibited a robust increase in the levels of inflammatory cytokines interleukin-6, tumor necrosis factor-α, transforming growth factor-β, and CXCL12, which trigger the epithelial–mesenchymal transition and pro-metastatic switch of CRC cells. More importantly, the activation of CAFs by miR-146a-5p and miR-155-5p facilitated tumor formation and lung metastasis of CRC in vivo using tumor xenograft models. Our work provides novel insights into CXCR7-mediated CRC metastasis from tumor–stroma interaction and serum exosomal miR-146a-5p and miR-155-5p could serve as potential biomarkers and therapeutic targets for inhibiting CRC metastasis.Subject terms: Cancer microenvironment, Colon cancer     

Downregulation of XIST ameliorates acute kidney injury by sponging miR-142-5p and targeting PDCD4

Acute kidney injury (AKI) is a common kidney disease that markedly affects public health. To date, the roles of long noncoding RNA XIST in AKI are poorly understood. Here, we investigated the biological functions of XIST in AKI. We observed that XIST expression increased in patients with AKI and HK-2 cells stimulated by CoCl₂. In addition, a rat AKI model induced by ischemia–reperfusion was established. Tumor necrosis factor-α, interleukin-6, and cyclooxygenase-2 messenger RNA expression were induced in vivo; moreover, XIST expression was upregulated. Knockdown of XIST significantly repressed CoCl₂-triggered injury in HK-2 cells. However, microRNA (miR)-142-5p, a downstream target of XIST, was downregulated in AKI. miR-142-5p was repressed by XIST and miR-142-5p could inhibit CoCl₂-induced injury in HK-2 cells. Moreover, PDCD4 expression was significantly increased in AKI. PDCD4 was predicted to be the target of miR-142-5p. Subsequently, loss of PDCD4 was able to retard injury in HK-2 cells exposed to CoCl_2. Thus, we suggest that XIST regulates miR-142-5p and PDCD4, and it has the potential to function as a biomarker in therapeutic strategies for AKI.     

miR-29a and miR-142-3p downregulation and diagnostic implication in human acute myeloid leukemia

Expression profiling of microRNAs (miRNAs) in most diseases might be popular and provide the possibility for diagnostic implication, but few studies have accurately quantified the expression level of dysregulated miRNAs in acute myeloid leukemia (AML). In this study, we analyzed the peripheral blood mononuclear cells (PBMCs) from 10 AML patients (subtypes M1 to M5) and six normal controls by miRNA microarray and identified several differentially expressed miRNAs. Among them miR-29a and miR-142-3p were selectively encountered in Northern blot analysis and their significantly decreased expression in AML was further confirmed. Quantitative real-time PCR in 52 primarily diagnosed AML patients and 100 normal controls not only verified the expression properties of these 2 miRNAs, but also established that the expression level of miR-142-3p and miR-29a in PBMCs could be used as novel diagnostic markers. A better diagnostic outcome was achieved by combining miR-29a and miR-142-3p with about 90% sensitivity, 100% specificity, and an area under the ROC curve (AUC) of 0.97. Our results provide insights into the involvement of miRNAs in leukemogenesis, and offer candidates for AML diagnosis and therapeutic strategy.     

Eradication of Helicobacter pylori in children in Vietnam in relation to antibiotic resistance

Background: Low Helicobacter pylori eradication rates are common in pediatric trials especially in developing countries. The aim of the study was to investigate the role of antibiotic resistance, drug dosage, and administration frequency on treatment outcome for children in Vietnam. Materials and Methods: Antibiotics resistance of H. pylori was analyzed by the Etest in 222 pretreatment isolates from children 3–15 years of age who were originally recruited in a randomized trial with two treatment regiments: lansoprazole with amoxicillin and either clarithromycin (LAC) or metronidazole (LAM) in two weight groups with once‐ or twice‐daily administration. The study design was an observational study embedded in a randomized trial. Results: The overall resistance to clarithromycin, metronidazole, and amoxicillin was 50.9%, 65.3%, and 0.5%, respectively. In LAC, eradication was linked to the strains being susceptible to clarithromycin (78.2% vs 29.3%, p = .0001). Twice‐daily dosage of proton‐pump inhibitor (PPI) and clarithromycin was more effective for eradication than once‐daily dosage for resistant strains (50.0% vs 14.7%, p = .004) and tended to be so also for sensitive strains (87.5% vs 65.2%, p = .051). Exact antibiotic dose per body weight resulted in more eradication for resistant strains (45.3% vs 8.0%, p = .006). These differences were less pronounced for the LAM regimen, with twice‐daily PPI versus once daily for resistant strains resulting in 69.2% and 50.0% eradication (p = .096), respectively. Conclusions: Helicobacter pylori clarithromycin resistance was unexpectedly high in young children in Vietnam. Clarithromycin resistance was an important cause for eradication treatment failure. Twice‐daily administration and exact antibiotic dosing resulted in more eradicated infections when the strains were antibiotic resistant, which has implications for the study design in pediatric H. pylori eradication trials.