Ying Qu

Down‐regulated miR‐625 suppresses invasion and metastasis of gastric cancer by targeting ILK

Accumulating evidence has shown that microRNAs are involved in multiple processes in cancer development and progression. Here, we report that expression of miR‐625 is significantly down‐regulated and negatively correlated with lymph node metastasis in gastric cancer. miR‐625 significantly inhibits invasion and metastasis of gastric cancer cells both in vitro and in vivo. Moreover, we identify that ILK is a direct target gene for miR‐625 and knockdown of ILK has a phenocopy of overexpression of miR‐625. Taken together, our findings suggest that miR‐625 plays an important role in the mechanism of tumor metastasis.

Clinical significance of human kallikrein 10 gene expression in colorectal cancer and gastric cancer

Background and Aim:  Recent evidence suggests that the human kallikrein 10 (KLK10) gene is differentially regulated in endocrine‐related tumors and has potential as diagnostic and/or prognostic marker; however, KLK10 expression has never been investigated in gastrointestinal cancers. The aims of this study were to demonstrate expression and single nucleotide polymorphisms of KLK10 in colorectal cancer (CRC) and gastric cancer (GC), and to correlate the relative KLK10 expression level with clinicopathological factors of CRC and GC.

Hepatocyte growth factor activates tumor stromal fibroblasts to promote tumorigenesis in gastric cancer.

Cancer-associated fibroblasts (CAFs), as the activated fibroblasts in tumor stroma, are important modifiers of tumor progression. However, the mechanisms underlying stromal fibroblast activation and their promotion of tumor growth remain largely unknown in gastric cancer. Here, we show that normal fibroblasts (NFs) from non-cancerous regions of gastric cancer exhibit the traits of CAFs when grown together with gastric cancer cells in vivo. Activation of NFs can be induced by co-culture with gastric cancer cells, while deprivation of hepatocyte growth factor (HGF) using a neutralizing antibody inhibits the activation of NFs. Moreover, we identify HGF as an important factor from CAFs that acts in a paracrine manner to promote tumorigenesis in vitro and in vivo. Taken together, these results suggest that HGF may play a pivotal role in the regulatory circuit between gastric cancer cells and stromal fibroblasts, and neutralization of HGF inhibits both activation and tumor-promoting properties of CAFs.

In vitro and in vivo evidence of metallopanstimulin-1 in gastric cancer progression and tumorigenicity.

Purpose: The metallopanstimulin-1 (MPS-1) gene is a growth factor–inducible gene, which is highly expressed in many human cancers and may be involved in the progression towards tumor malignancy. However, it is unclear whether MPS-1 plays any role in gastric cancer development or progression. Our studies were designed to clarify the MPS-1 expression pattern and to explore its potential role in gastric cancer. Experimental Design: The expression pattern of MPS-1 was determined in primary gastric cancer specimens and gastric cancer cell lines via immunohistochemistry and Western blotting. To investigate the functional significance of MPS-1 expression, three small interfering RNA (siRNA) expression plasmids were constructed and transfected into gastric cancer cell line SGC7901. The stable cell lines transfected with the siRNA targeting MPS-1 mRNA plasmids were selected and the biological features of these cells were examined. Results: MPS-1 was overexpressed in 86% of the gastric cancer tissues and all gastric cancer cells. In addition, MPS-1 expression was significantly increased and corresponded with the tumor-node-metastasis clinical stage, and was significantly higher in the late stage (P < 0.01). The MPS-1 expression level was significantly decreased in the transfected cells with MPS-1-specific siRNA expression plasmid pRNAT-133. Furthermore, the stable transfected cancer cells exhibited an increase in the incidence of spontaneous apoptosis and a decrease in growth ability and tumorigenicity in nude mice. Conclusions: These results provide strong evidence that MPS-1 plays an important role in gastric cancer cell proliferation and development, and suggests that MPS-1 is a promising target for gastric cancer treatment.

Exosomes derived from miR-181-5p-modified adipose-derived mesenchymal stem cells prevent liver fibrosis via autophagy activation

Proliferating hepatic stellate cells (HSCs) respond to liver damage by secreting collagens that form fibrous scar tissue, which can lead to cirrhosis if in appropriately regulated. Advancement of microRNA (miRNA) hepatic therapies has been hampered by difficulties in delivering miRNA to damaged tissue. However, exosomes secreted by adipose‐derived mesenchymal stem cells (ADSCs) can be exploited to deliver miRNAs to HSCs. ADSCs were engineered to overexpress miRNA‐181‐5p (miR‐181‐5p‐ADSCs) to selectively home exosomes to mouse hepatic stellate (HST‐T6) cells or a CCl4‐induced liver fibrosis murine model and compared with non‐targeting control Caenorhabditis elegans miR‐67 (cel‐miR‐67)‐ADSCs. In vitro analysis confirmed that the transfer of miR‐181‐5p from miR‐181‐5p‐ADSCs occurred via secreted exosomal uptake. Exosomes were visualized in HST‐T6 cells using cyc3‐labelled pre‐miRNA‐transfected ADSCs with/without the exosomal inhibitor, GW4869. The effects of miRNA‐181‐5p overexpression on the fibrosis associated STAT3/Bcl‐2/Beclin 1 pathway and components of the extracellular matrix were assessed. Exosomes from miR181‐5p‐ADSCs down‐regulated Stat3 and Bcl‐2 and activated autophagy in the HST‐T6 cells. Furthermore, the up‐regulated expression of fibrotic genes in HST‐T6 cells induced by TGF‐β1 was repressed following the addition of isolated miR181‐5p‐ADSC exosomes compared with miR‐67‐ADSCexosomes. Exosome therapy attenuated liver injury and significantly down‐regulated collagen I, vimentin, α‐SMA and fibronectin in liver, compared with controls. Taken together, the effective anti‐fibrotic function of engineered ADSCs is able to selectively transfer miR‐181‐5p to damaged liver cells and will pave the way for the use of exosome‐ADSCs for therapeutic delivery of miRNA targeting liver disease.

Over-expression of FRZB in gastric cancer cell suppresses proliferation and induces differentiation

PurposeFrizzled motif associated with bone development (FRZB) was a member of secreted frizzled related proteins (sFRPs) family. Previous evidences showed that FRZB played role in embryogenesis and diseases such as osteoarthritis and prostate cancer. The purpose of our study is to clarify the role of FRZB in gastric cancer cell proliferation and differentiation.MethodsThe expression of FRZB in gastric cancer tissues were detected by immunohistochemistry. The expression of FRZB in eight gastric cancer cell lines and one immortal gastric epithelial cell GES-1 were detected by western blotting and real-time quantitative PCR. To investigate the role of over-expressed FRZB in gastric cancer cells, FRZB/pcDNA3.1 plasmid was constructed and transfected into gastric cancer cell line SGC7901. The changes of biological features in these stable transfectants were examined.ResultsFRZB was highly expressed in gastric cancer (90%), intestinal metaplasia (100%) and gastric dysplasia (90%), but no or just weakly (3/40) expressed in normal gastric mucosa. FRZB staining was stronger in intestinal-type gastric cancer tissues than that in diffuse-type ones and was positive correlated with differentiation grade. The expression of FRZB in eight gastric cancer cell lines was higher than in GES-1. Over-expressed FRZB inhibited cell proliferation in vitro and in vivo which was first caused by prolonged cell division progression in G2/M phase, and second by higher sensitivity to apoptotic inducing factors and spontaneous apoptosis. Our findings gave evidences that FRZB suppressed gastric cancer cell proliferation and modulated the balance between proliferation and differentiation in gastric cancer.

Metallopanstimulin-1 regulates invasion and migration of gastric cancer cells partially through integrin β4

MPS-1 (metallopanstimulin-1), also known as ribosomal protein S27, was overexpressed in gastric cancer cells. However, how MPS-1 contributes to gastric carcinogenesis has not been well characterized. Here, we show that high expression of MPS-1 was observed in gastric cancer tissues and associated with gastric cancer cell metastasis. Alteration of MPS-1 expression regulates invasion and migration of gastric cancer cells both in vitro and in vivo. Furthermore, by using Signal-Net and cluster analyses of microarray data we identified integrin β4 (ITGB4) as a downstream target of MPS-1 that mediates its effects on cell metastasis. Knockdown of MPS-1 expression in gastric cancer cells led to significant reduction of ITGB4 expression at both the RNA and protein levels. Mechanically, we found that overexpression of ITGB4 in MPS-1 knockdown cells largely recovers the ability of invasion and migration. Conversely, knockdown of ITGB4 partially reduced cell invading/migrating ability induced by MPS-1 overexpression. Moreover, MPS-1 and ITGB4 expressions are positively correlated in gastric cancer cell lines and tissues. Finally, the survival analyses show that the expression of MPS-1 and ITGB4 is associated with poor outcomes in gastric cancer patients. Collectively, our findings suggest that MPS-1 regulates cell invasiveness and migration partially through ITGB4 and that MPS-1/ITGB4 signaling axis may serve as therapeutic targets in the treatment of gastric cancer.

Knockdown of metallopanstimulin-1 inhibits NF-κB signaling at different levels: The role of apoptosis induction of gastric cancer cells

The ribosomal protein S27 (metallopanstimulin‐1, MPS‐1) has been reported to be a multifunctional protein, with increased expression in a number of cancers. We reported previously that MPS‐1 was highly expressed in human gastric cancer. Knockdown of MPS‐1 led to spontaneous apoptosis and repressed proliferation of human gastric cancer cells in vitro and in vivo. However, how does MPS‐1 regulate these processes is unclear. Here we performed microarray and pathway analyses to investigate possible pathways involved in MPS‐1 knockdown‐induced apoptosis in gastric cancer cells. Our results showed that knockdown of MPS‐1 inhibited NF‐κB activity by reducing phosphorylation of p65 at Ser536 and IκBα at Ser32, inhibiting NF‐κB nuclear translocation, and down‐regulating its DNA binding activity. Furthermore, data‐mining the Gene‐Regulatory‐Network revealed that growth arrest DNA damage inducible gene 45β (Gadd45β), a direct NF‐κB target gene, played a critical role in MPS‐1 knockdown‐induced apoptosis. Over‐expression of Gadd45β inhibited MPS‐1 knockdown‐induced apoptosis via inhibition of JNK phosphorylation. Taken together, these data revealed a novel pathway, the MPS‐1/NF‐κB/Gadd45β signal pathway, played an important role in MPS‐1 knockdown‐induced apoptosis of gastric cancer cells. This study sheds new light on the role of MPS‐1/NF‐κB in apoptosis and the possible use of MPS‐1 targeting strategy in the treatment of gastric cancer.

AZGP1 suppresses epithelial-to-mesenchymal transition and hepatic carcinogenesis by blocking TGFβ1-ERK2 pathways.

Zinc-α2-glycoprotein 1 (AZGP1) has been found to play important roles in TGF-β1 induced epithelial-to-mesenchymal transition (EMT). However, the mechanisms of AZGP1 inhibiting EMT and its therapeutic potential remain unknown in hepatocellular carcinoma (HCC). AZGP1, TGF-β1 or ERK2 expressions were examined in liver tissues of HCC patients and rat model. The effect of AZGP1 on EMT and crosstalking of TGFβ1-ERK2 signaling in human hepatic cancer cell was tested in vitro and in vivo. Hepatic expression of AZGP1 was nearly deficient in HCC patients and rats. It was proved that AZGP1 has the ability of down-regulating mesenchymal markers, up-regulating epithelial marker, inhibiting cell invasion and suppressing EMT in human HCC cells. The results clarified that AZGP1 has the effect on blocking TGF-β1 mediated ERK2 phosphorylation leading to depressing EMT and invasive potential in vitro. Local injection of AZGP1 mimic in vivo could significantly withhold lung metastasis in HCC. In conclusion, loss of AZGP1 could trigger EMT induced by TGFβ1-ERK2 signaling, confuse in energy metabolism, reduce cell proliferation and apoptosis, activate survival signals and promote invasion. Up-regulation of AZGP1 should be proposed to reverse EMT and might be a new promising therapy for HCC.

MicroRNA profile analysis in the liver fibrotic tissues of chronic hepatitis B patients

We aimed to identify the features of microRNA (miRNA) at different fibrotic stages in patients with hepatitis B virus (HBV)‐related liver fibrosis.