Yueguo Wang

Myeloma cell adhesion to bone marrow stromal cells confers drug resistance by microRNA-21 up-regulation

Abstract The bone marrow microenvironment plays a role in myeloma cell proliferation and adhesion-mediated drug resistance. In this study, we investigated microRNA-21 (miR-21) expression changes in myeloma cells that adhered to bone marrow stromal cells (BMSCs). In addition, we studied the synergistic effect of miR-21 inhibition with dexamethasone (Dex), doxorubicin (Dox), or bortezomib (Bort) on myeloma cell survival. We found that up-regulation of miR-21 expression was partially driven by nuclear factor-κB (NF-κB) signaling via myeloma cell adhesion to BMSCs. We also confirmed that RhoB is a miR-21 regulation target gene. Moreover, miR-21 inhibition combined with cytotoxic drug Dex or Dox inhibited myeloma cell survival more effectively than either treatment alone. These results suggest that the regulatory mechanisms of miR-21 expression may be a promising target for fine-tuning anti-myeloma therapy.

Cell-Free circulating DNA: a new biomarker for the acute coronary syndrome.

Background: In recent studies, concentrations of cell-free circulating DNA (cf-DNA) have been correlated with clinical characteristics and prognosis in several diseases. The relationship between cf-DNA concentrations and the acute coronary syndrome (ACS) remains unknown. Moreover, no data are available for the detection cf-DNA in ACS by a branched DNA (bDNA)-based Alu assay. The aim of the present study was to investigate cf-DNA concentrations in ACS and their relationship with clinical features. Methods: Plasma cf-DNA concentrations of 137 ACS patients at diagnosis, of 60 healthy individuals and of 13 patients with stable angina (SA) were determined using a bDNA-based Alu assay. Results: ACS patients (median 2,285.0, interquartile range 916.4–4,857.3 ng/ml), especially in ST-segment elevation myocardial infarction patients (median 5,745.4, interquartile range 4,013.5–8,643.9 ng/ml), showed a significant increase in plasma cf-DNA concentrations compared with controls (healthy controls: median 118.3, interquartile range 81.1–221.1 ng/ml; SA patients: median 202.3, interquartile range 112.7–256.1 ng/ml) using a bDNA-based Alu assay. Moreover, we found positive correlations between cf-DNA and Gensini scoring and GRACE (Global Registry of Acute Coronary Events) scoring in ACS. Conclusion: cf-DNA may be a valuable marker for diagnosing and predicting the severity of coronary artery lesions and risk stratification in ACS.

A sensitive method to quantify human cell-free circulating DNA in blood: relevance to myocardial infarction screening.

OBJECTIVES Human cell-free circulating DNA (cf-DNA) derived mainly from cell apoptosis and necrosis can be measured by a variety of laboratory techniques, but almost all of these methods require sample preparation. We have developed a branched DNA (bDNA)-based Alu assay for quantifying cf-DNA in myocardial infarction (MI) patients. DESIGN AND METHODS A total of 82 individuals were included in the study; 22 MI and 60 normal controls. cf-DNA was quantified using a bDNA-based Alu assay. RESULTS cf-DNA was higher in serum compared to plasma and there was a difference between genders. cf-DNA was significantly higher in MI patients compared to the controls. There was no correlation between cf-DNA and creatine kinase-MB (CK-MB), troponin I (cTnI) or myoglobin (MYO). In serial specimens, cf-DNA was sensitive and peaked earlier than cTnI. CONCLUSIONS The bDNA-based Alu assay is a novel method for quantifying human cf-DNA. Increased cf-DNA in MI patients might complement cTnI, CK-MB and MYO in a multiple marker format.

Correlation of expression levels of BLyS and its receptors with multiple myeloma.

OBJECTIVES To measure the expression levels of B-lymphocyte stimulator (BLyS) and its receptors in multiple myeloma (MM), and to investigate the relationship between them. DESIGN AND METHODS BLyS and its receptors mRNA levels from peripheral blood mononuclear cells (PBMCs) of 31 MM patients and 30 healthy controls were determined by real-time PCR. The results were presented as the ratios of target genes, to beta(2)-microglobulin (beta(2)M), mRNA. BLyS serum level was determined by enzyme-linked immunosorbent assay (ELISA). RESULTS The circulating levels of BLyS in 31 MM patients were significantly elevated and correlated with the levels of Lactate dehydrogenase (LDH). More importantly, 93.55% (29/31) and 90.32% (28/31) of these MM patients had significantly higher expression levels of BLyS and BCMA mRNA respectively, which are correlated with the levels of LDH, while 64.52% (20/31) of these MM patients had significantly lower expression levels of TACI mRNA. CONCLUSION BLyS protein concentration and BLyS, TACI and BAFF-R mRNA expression levels were significantly elevated in patients with MM, suggesting that BLyS, TACI and BAFF-R may be involved in the pathogenesis of MM, and that expression levels could serve as a biomarker of prognosis.

APRIL knockdown suppresses migration and invasion of human colon carcinoma cells

OBJECTIVE The purpose of this study was to investigate the function of a proliferation-inducing ligand (APRIL) gene among the metastatic colorectal cancer (CRC) disease. METHODS Cell adhesion, cell migration and invasion behavior were detected after knockdown of APRIL expression in the colon carcinoma cell line, SW480 by RNAi and the rescue experiments were performed with recombinant human APRIL (rhAPRIL) in vitro. RESULTS This original study indicated that knockdown of APRIL expression strongly inhibited colon carcinoma cell adhesion, cell migration and invasion in vitro. By contrast, reconstitution of APRIL expression with rhAPRIL in these APRILi cells, prominently restores CRC cell migration and invasion. CONCLUSION These results strongly suggest that APRIL play an important role in the tumor development of the invasive or migratory behavior of CRC cells and may be a useful therapeutic target in the malignant colon carcinomas.

Reduced APRIL Expression Induces Cellular Senescence via a HSPG-Dependent Pathway

APRIL, a member of the TNF superfamily, can induce cell proliferation and is overexpressed in most tumor tissues or cells. Nevertheless, it is still unknown about the effect of decreased levels of APRIL expression on tumor cells. In this study, we analyzed APRIL and HSPG expression in the colon carcinoma cell line, SW480 by Western blot and RT-PCR. And the up-regulation of APRIL and HSPG expression was found in SW480. We also observed that knockdown of APRIL levels in SW480, prominently reversed cell proliferation and partially resulted in senescence phenotypes. Furthermore, cellular senescence due to a decreased level of APRIL expression was associated with engagement of HSPG. Thus, our results suggest that low levels of APRIL play an essential role in cellular senescence via a HSPG-dependent signaling pathway in SW480.

The Effect of APOC3 Promoter Polymorphisms on the Risk of Hypertriglyceridemia in Chinese Han Population With or Without Type 2 Diabetes Mellitus

Background: Promoter polymorphisms in the apolipoprotein C3 (APOC3) gene are associated with hypertriglyceridemia (HTG), which is a complication of Type 2 Diabetes Mellitus (T2DM). Because there is a strong insulin resistance in T2DM, it is essential to investigate whether the APOC3 promoter variation affects plasma lipid profiles in the population with or without T2DM. Methods: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was performed to detect the genotypes of APOC3. The levels of serum lipid profiles were also studied by biochemical methods. Results: In the control group, the prevalence of the −455CC or −482TT variants was higher in persons with HTG compared to those with normal triglyceride (NTG). Compared with the most common genotype, −455TT or −482CC, the variants had a significantly increased HTG risk in this population. However, a similar association was not found in the T2DM group. Conclusions: There was no relationship between promoter rare allele −455C or −482T of APOC3 gene and HTG in T2DM, but both the rare alleles contributed to an increased risk of HTG in the control group without T2DM.

Analysis of Dyslipidemia in Nephrotic Syndrome by Capillary Isotachophoresis

Hyperlipidaemia is a secondary change in nephrotic syndrome (NS) patients. Recent studies have highlighted increased risks of atherosclerosis and progression of renal disease associated with nephrotic dyslipidemia. All apolipoprotein B (apoB)-containing lipoproteins, including very-low-density lipoproteins (VLDL), intermediate-density lipoproteins (IDL), low-density lipoproteins (LDL), and lipoprotein(a) [Lp(a)] are elevated in NS patients, while high-density lipoproteins (HDL) remain unchanged or even reduced. In addition, the lipoprotein composition undergoes a marked change, with a higher ratio of cholesterol to triglyceride in apoB-containing lipoproteins and an increase in the proportion of cholesterol, cholesterol ester, and phospholipids compared with proteins. This change in LDL and HDL cholesterol could no longer represent LDL and HDL particles exactly, underscoring the need for an easy and feasible means of analyzing lipoproteins effectively. Unlike capillary zone electrophoresis, cITP can separate mixed sample zones into pure zones of individual substances according to differences in their electrophoretic mobilities by using a discontinuous electrolyte system. Once the separation is completed, a steady state exists and the zones migrate in the order of decreasing mobilities but with the same velocity. The sharpening and self-focusing effect is another special feature of cITP, which improves resolution of small charge differences within lipoparticles and increases fluorescent detection sensitivity of minor lipoprotein subclasses. 1