Xudong 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.

Livin gene plays a role in drug resistance of colon cancer cells

OBJECTIVEnThe objective of this study was to investigate the effect of knockdown of Livin expression on reversing drug resistance phenotype of colon cancer HCT-8/V cells.nnnDESIGN AND METHODSnSpecific short hairpin RNA (shRNA) was chosen and transfected in human colon cancer HCT-8/V cell line. Cell apoptosis and chemosensitivity were evaluated following downregulation of Livin expression.nnnRESULTSnIn the current study, Livin was found to be highly expressed in the HCT-8/V colon cancer cells, which were resistant to several anti-tumor drugs. Knocking down of Livin expression in HCT-8/V cells by specific RNAi facilitated the apoptosis of HCT-8/V cells in response to vincristine (VCR), etoposide (VP-16), and 5-flourouracil (5-FU). Chemosensitivity assay confirmed the results and demonstrated the reversal of drug resistance phenotype of HCT-8/V cells.nnnCONCLUSIONnThese data suggest that specific silencing of Livin gene expression could be a promising target for further research in clinical chemotherapy of colon cancer.

APRIL Induces Tumorigenesis and Metastasis of Colorectal Cancer Cells via Activation of the PI3K/Akt Pathway

A proliferation-inducing ligand (APRIL) is highly expressed in colorectal cancer (CRC) tissues and cell lines. However, the biological functions and precise signals elicited by APRIL in CRC have not been fully understood. Here, we used small interfering RNA to selectively deplete APRIL and to determine its tumorigenic effects in a CRC cell line SW480 both in vitro and in vivo. Knockdown of APRIL in SW480 cells was associated with modulation of cell proliferation as well as reduction of cell migration and invasion in vitro. Moreover APRIL-knockdown SW480 cells displayed markedly inhibited tumor growth and decreased metastasis to the liver in immunodeficient mice upon subcutaneous injection. Importantly, we observed that downregulation of APRIL in SW480 cells resulted in greatly decreased activity of phosphoinositide 3-kinase (PI3K)/Akt pathway. In addition, we observed that recombinant human APRIL mediated activation of the PI3K/Akt pathway in CRC cells resulting in induced expression of important cell cycle proteins and matrix metalloproteinases in a PI3K/Akt dependent manner. This was concurrent with marked cell growth viability as well as increased cell migration and invasion. Together, these compelling data suggest that APRIL-induced tumorigenesis and metastasis of CRC cells may be accomplished through activation of the PI3K/Akt pathway. These findings may lead to a better understanding of the biological effects of APRIL and may provide clues for identifying novel therapeutic and preventive molecular markers for CRC.

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

OBJECTIVESnTo measure the expression levels of B-lymphocyte stimulator (BLyS) and its receptors in multiple myeloma (MM), and to investigate the relationship between them.nnnDESIGN AND METHODSnBLyS 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).nnnRESULTSnThe 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.nnnCONCLUSIONnBLyS 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.

Upregulated lncRNA-PCAT1 is closely related to clinical diagnosis of multiple myeloma as a predictive biomarker in serum.

OBJECTIVEnThe purpose of this study was to explore serum PCAT-1 expression in multiple myeloma (MM) and examine the potential usefulness of this molecule as a biomarker for diagnosis in MM.nnnMETHODSnSerum samples were collected from 60 newly diagnosed untreated MM patients, and 48 healthy controls. Serum PCAT-1 expression levels were detected by RT-qPCR. In addition, correlations between the relative expression of serum PCAT-1 and the concentrations of lactic acid dehydrogenase (LDH), β2M, λ light chain and κ light chain were assessed.nnnRESULTSnIt was found that the relative expression of serum PCAT-1 in MM patients (81.02 ± 136.9) was higher than that in healthy controls (3.17 ± 5.75) (U= 307.0, P< 0.0001) and was significantly correlated with β2M concentration (r= 0.461, P= 0.0002), but not with LDH, κ light and λ light chain concentration (r= 0.061, P= 0.641; r= 0.007, P= 0.956; r=-0.090, P= 0.499 respectively). Additionally, it was significantly correlated with different isotype of MM (H= 7.464, P= 0.024). The AUC of the ROC curve of serum PCAT-1 was 0.892 (95% CI 0.833-0.950), which was higher than other markers. Combining PCAT-1 and β2M together, the sensitivity was highest compared with other markers alone, or combined.nnnCONCLUSIONnThe expression levels of serum PCAT-1 in MM patients were significantly higher than that in healthy controls, suggesting that it may be useful in the auxiliary diagnosis of MM.

BLyS expression and JNK activation may form a feedback loop to promote survival and proliferation of multiple myeloma cells.

B-Lymphocyte stimulator (BLyS), a member of tumor necrosis factor superfamily, is a potent co-activator of B cells in vitro, and in vivo induces B cell proliferation and immunoglobulin secretion. Multiple myeloma (MM) is an incurable malignancy of terminally differentiated B cells (plasma cells). Previous studies have well ascertained that BLyS plays an important contributory role in the pathogenesis and propagation of multiple myeloma by virtue of its ability to promote B cell survival, expansion, and differentiation. However, the intracellular signaling of BLyS in human MM cells remains undefined. This study was designed to see whether there was interaction between MAPK signaling pathway and BLyS expression. It was found that the active protein p-JNK was expressed in KM3, U266 and PBMCs of MM patients, and that the expression of BLyS could be changed by JNK pathway activator and inhibitor. In addition, recombinant BLyS activated JNK pathway, while BLyS siRNA treatment inhibited the activation of JNK pathway. The level of BLyS expression and the activation of JNK pathway were positively correlated. These findings suggest that JNK activation and BLyS expression in MM cells may form a positive feedback loop that promotes the survival and proliferation of MM cells, and these may shed some light on the pathogenesis and treatment of MM.

Serum level of long noncoding RNA H19 as a diagnostic biomarker of multiple myeloma

Circulating long noncoding RNA (lncRNA) H19 has been reported to be a biomarker for cancer monitoring. The purpose of this study was to determine whether serum lncRNA could serve as a novel biomarker for the diagnosis of multiple myeloma (MM) and evaluate its value of clinical application. In our study, the expression of lncRNA H19 was up-regulated in 80 patients with MM and MM cell lines by RT-PCR analysis. Clinicopathological analysis showed the expression level of H19 could assist clinical staging, and the severity of the disease could be roughly determined according to the amount of H19 expressed in the patient serum. This is the first report to show that H19 was expressed in the serum of MM patients, suggesting that upregulation of serum lncRNA H19 may prove to be a novel biomarker for early diagnosis and clinical treatment of MM.

Combined detection of plasma miR-127-3p and HE4 improves the diagnostic efficacy of breast cancer

OBJECTIVEnTo explore the diagnostic value of combined detection of plasma miR-127-3p and HE4 for breast cancer (BC).nnnMETHODSnIncluded in this study were 102 patients with pathologically confirmed BC who received treatment in the affiliated hospital of Nantong University between March 2015 and April 2016, 87 patients with benign breast tumors, and 90 healthy volunteers as control. Plasma miR-127-3p was detected by SYBR Green RT-qPCR, and plasma HE4 was detected by chemiluminescent immunoassay. The diagnostic efficacy of miR-127-3p alone, HE4 alone and combined detection of miR-127-3p and HE4 in BC women patients was evaluated by ROC curve analysis.nnnRESULTSnThe relative expression quantity (RQ) of plasma miR-127-3p and HE4 in BC patients was 13.561 (3.345∼18.281) pmol/L and 105.42 (40.28∼156.31) pmol/L. The RQ of plasma miR-127-3p in BC patients was significantly higher than that in benign breast tumor patients and healthy individuals (both P< 0.001), and there was no significant difference between benign breast tumor patients and healthy individuals (P> 0.05). There was no significant correlation between plasma miR-127-3p and HE4 levels (r2= 0.086, P= 0.471). ROC curve analysis on the diagnostic efficacy of plasma miR-127-3p and HE4 in BC diagnosis showed that the cut-off value of miR-127-3p and HE4 in BC diagnosis was 3.471 and 63.21 pmol/L; AUC was 0.767 and 0.670; sensitivity was 78.2% and 64.6%; specificity was 79.1% and 69.3%; accuracy was 73.2% and 65.1%, respectively. Prediction probability (P) obtained from the miR-127-3p and HE4 model established by logistic regression was P= 1/ [1 + exp (-0.142miR-127-3p-0.024HE4 + 2.875)]. AUC calculated from ROC was 0.825 and the sensitivity was increased to 87.4%.nnnCONCLUSIONnCombined detection of plasma miR-127-3p and HE4 greatly improved the sensitivity of BC diagnosis and may prove to be a candidate biomarker for early detection and diagnosis of BC.

BRCA1 and BRCA2 expression patterns and prognostic significance in digestive system cancers

The role of BRCA1 and BRCA2 genes is mainly to maintain genome integrity in response to DNA damage through different mechanisms. Deregulation of BRCA1 and BRCA2 is associated with the development of tumor and altered sensitivity to chemotherapeutic agents. In this study, we determined protein expression of BRCA1 and BRCA2 in 4 digestive system cancers (gastric cancer, colorectal cancer, hepatocellular carcinoma, and pancreatic cancer) by immunohistochemistry on tissue microarrays. A total of 1546 samples of 4 types of cancer tissues, their matched adjacent nontumor tissues, and corresponding benign tissues were studied, respectively. Immunohistochemistry expression patterns of the 2 proteins and their correlation with patients clinical parameters and overall survival were analyzed. The results showed that low expression of cytoplasmic BRCA1 and BRCA2 was commonly associated with advanced tumor-lymph node-metastasis stage, whereas high expression of nuclear BRCA1 was generally correlated with advanced tumor stages in these cancers. High expression of cytoplasmic BRCA1 and BRCA2 had significantly favorable overall survival in digestive system cancers; in contrast, BRCA1 nuclear expression usually predicted poor outcomes. We conclude that BRCA1 and BRCA2 could be used as clinicopathological biomarkers to evaluate the prognosis of digestive system cancers.

Significance of BAFF/APRIL Expression and Their Receptors in Pediatric Patients With Acute Lymphoblastic Leukemia.

In this study, we investigated the mRNA expression and protein levels of B-cell activating factor (BAFF)/a proliferation-inducing ligand (APRIL) and their receptors in acute lymphoblastic leukemia (ALL) cell lines and pediatric patients with ALL using real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and Western blotting. The location and level of the BAFF/APRIL proteins in ALL cell lines were also detected by immunofluorescence cytochemistry and flow cytometry. Correlations between plasma protein levels of BAFF/APRIL and primary clinical parameters were analyzed. We found that BAFF/APRIL was highly expressed in pediatric ALL patients and ALL cell lines. The BAFF/APRIL proteins were located on the cell membrane, and the proportion of positive cells and mean fluorescence intensity were significantly higher than in the healthy control group (P<0.05). The mRNA expression and protein levels of BAFF/APRIL and their receptors in untreated ALL children were significantly higher than in healthy controls (P<0.05) as well as were significantly reduced in the remission group (P<0.05). The plasma protein levels of BAFF/APRIL were positively correlated with the white blood cell count, lactate dehydrogenase, and serum ferritin. Abnormal levels of BAFF/APRIL in pediatric ALL suggest that BAFF/APRIL are associated with the development and progression of ALL in children and may provide information for the development of BAFF-based and APRIL-based targeted therapies.