Shaoqing Ju

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.

Long non-coding RNA HULC as a novel serum biomarker for diagnosis and prognosis prediction of gastric cancer

Long non-coding RNAs (lncRNAs) have recently emerged as vital players in tumor biology with potential value in cancer diagnosis, prognosis, and therapeutics. The lncRNA HULC (highly up-regulated in liver cancer) is increased in many malignancies, yet its serum expression profile and clinical value in gastric cancer (GC) patients remain unclear. Quantitative real-time polymerase chain reaction (RT-qPCR) for large-scale analysis of the serum expression of HULC in GC patients reliably detected circulating HULC and revealed that it is upregulated in GC patients. A high serum HULC level correlated with tumor size, lymph node metastasis, distant metastasis, tumor-node-metastasis stage, and H. pylori infection. The area under the ROC curve for HULC was up to 0.888, which was higher than that for CEA (0.694) and CA72-4 (0.514). Follow-up detection and Kaplan-Meier curve analysis revealed HULC is a good predictor of GC prognosis. Our present study indicates that circulating HULC may represent a novel serum tumor marker for early diagnosis and monitoring progression and prognosis of GC.

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.

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

OBJECTIVE The 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. DESIGN AND METHODS Specific 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. RESULTS In 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. CONCLUSION These 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.

Serum APRIL, a potential tumor marker in pancreatic cancer

Abstract Background: A proliferation-inducing ligand (APRIL) is a newly-found member in the tumor necrosis factor (TNF) superfamily. Our previous studies have already confirmed that APRIL is overexpressed in pancreatic cancer tumors, however, it is not expressed or has a weak expression in normal pancreatic gland tissues. Furthermore, there is no report on serum APRIL in patients with pancreatic diseases. Herein, in order to explore the clinical implication of serum APRIL in patients with pancreatic cancer, serum APRIL, together with carcinoembryonic antigen (CEA) and carbohydrate antigen (CA)19-9, was examined. Methods: Serum APRIL was tested by ELISA in patients with pancreatic cancer. Meanwhile, two other conventional serum tumor markers, CEA and CA19-9, were measured by Elecsys 2010 Chemistry Analyzer. Results: Serum APRIL increased in patients with pancreatic cancer, which proved a positive correlation with CEA and CA19-9. When the diagnosis of benign or malignant condition was examined by one tumor marker, the sensitivity of APRIL alone (70.1%) was greater than that of CEA alone (56.7%), and the specificity of APRIL alone (85.5%) was higher than that of CA19-9 alone (83.6%). When examined by a combination of two markers, the sensitivity of the combination of APRIL and CA19-9 was the highest (88.1%), as it was compared with that of APRIL alone, CEA alone and APRIL+CEA, p<0.05. In addition, serum APRIL also correlated with the tumor stage and postoperative survival in patients with pancreatic cancer. Conclusions: Our results indicate that serum APRIL, as a potential biomarker, has a positive diagnosis and prognosis value for pancreatic cancer. Moreover, the combination assay of APRIL and CA19-9 is highly sensitive to pancreatic cancer.

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.

Transplantation of RADA16-BDNF peptide scaffold with human umbilical cord mesenchymal stem cells forced with CXCR4 and activated astrocytes for repair of traumatic brain injury.

Due to the poor self-regeneration of brain tissue, stem cell transplantation therapy is purported to enable the replacement of lost neurons after traumatic brain injury (TBI). The main challenge of brain regeneration is whether the transplanted cells can survive and carry out neuronal functions in the lesion area. The brain is a complex neuronal network consisting of various types of cells that significantly influence on each other, and the survival of the implanted stem cells in brain is critically influenced by the surrounding cells. Although stem cell-based therapy is developing rapidly, most previous studies just focus on apply single type of stem cells as cell source. Here, we found that co-culturing human umbilical cord mesenchymal stem cells (hUC-MSCs) directly with the activated astrocytes benefited to the proliferation and neuron differentiation of hUC-MSCs in vitro. In this study, hUC-MSCs and the activated astrocytes were seeded in RADA16-BDNF peptide scaffold (R-B-SPH scaffold), a specifical self-assembling peptide hydrogel, in which the environment promoted the differentiation of typical neuron-like cells with neurites extending in three-dimensional directions. Moreover, the results showed co-culture of hUC-MSCs and activated astrocytes promoted more BDNF secretion which may benefit to both neural differentiation of ectogenic hUC-MSCs and endogenic neurogenesis. In order to promote migration of the transplanted hUC-MSCs to the host brain, the hUC-MSCs were forced with CXC chemokine receptor 4 (CXCR4). We found that the moderate-sized lesion cavity, but not the large cavity caused by TBI was repaired via the transplantation of hUC-MSCsCXCR4 and activated astrocytes embedded in R-B-SPH scaffolds. The functional neural repair for TBI demonstrated in this study is mainly due to the transplantation system of double cells, hUC-MSCs and activated astrocytes. We believe that this novel cell transplantation system offers a promising treatment option for cell replacement therapy for TBI. STATEMENT OF SIGNIFICANCE In this reach, we specifically linked RGIDKRHWNSQ, a functional peptide derived from BDNF, to the C-terminal of RADARADARADARADA (RADA16) to structure a functional self-assembling peptide hydrogel scaffold, RADA16-BDNF (R-B-SPH scaffold) for the better transplantation of the double cell unit. Also, the novel scaffold was used as cell-carrier for transplantation double cell unit (hUC-MSCs/astrocyte) for treating traumatic brain injury. The results of this study showing that R-B-SPH scaffold was pliancy and flexibility to fit the brain lesion cavity and promotes the outgrowth of axons and dendrites of the neurons derived from hUC-MSCs in vitro and in vivo, indicating the 3D R-B-SPH scaffold provided a suitable microenvironment for hUC-MSC survival, proliferation and differentiation. Also, our results showing the double-cells transplantation system (hUC-MSCs/astrocyte) may be a novel cell-based therapeutic strategy for neuroregeneration after TBI with potential value for clinical application.

Recent Advances in Clinical Applications of Circulating Cell-free DNA Integrity

Circulating DNA is an emerging biomarker in various types of cancer. It is generally believed that DNA released from apoptotic cells is uniformly truncated to small DNA fragments with 185-200 base pair (bp), whereas DNA produced by malignant cells varies in size (most of these are longer DNA fragments). Recently, the application of circulating DNA integrity indexes, represented by the ratio of the longer DNA fragments concentration to the shorter ones, has been reported in different cancers. This review will summarize the recently reported assays for detection of the circulating cell-free DNA (ccf-DNA) integrity and their clinical utility.