sCLU Overexpression Research Articles

Secreted clusterin inhibits keloid formation by promoting fibroblast apoptosis.

Secretory clusterin promotes oral cancer cell survival via inhibiting apoptosis by activation of autophagy in AMPK/mTOR/ULK1 dependent pathway

BackgroundTo explore the modulatory effects and mechanism of secretory clusterin (sCLU) on cancer stem cell (CSC) properties in hepatocellular carcinoma (HCC).MethodsThe effects of sCLU repression or overexpression on chemoresistance, migration, invasion, and tumor growth were detected by MTT, wound healing, transwell assays, and xenograft assay, respectively. The tumor sphere assay was performed to evaluate the self-renewal ability of HCC cells. In addition, the molecular regulation between sCLU and AKT/GSK-3β/β-catenin axis in HCC cells were discovered by western blotting, quantitative real-time PCR (qRT-PCR), and immunofluorescence. The expression status of sCLU and β-catenin in HCC tissues were investigated by immunohistochemistry.ResultsKnockdown or overexpressing sCLU remarkably inhibited or promoted the chemoresistance against sorafenib/doxorubicin, metastasis, and tumor growth of HCC cells, respectively. HepG2 and HCCLM3-derived spheroids showed higher expression of sCLU than that in attached cells. Additionally, repressing sCLU impaired the self-renewal capacity of HCC cells and CSC-related chemoresistance while overexpression of sCLU enhanced these CSC properties. Knockdown or overexpression of sCLU inhibited or increased the expressions of β-catenin, cyclinD1, MMP-2 and MMP-9, and the phosphorylation of AKT or GSK3β signaling, respectively. However, LiCl or LY294002 abrogated the effects mediated by sCLU silencing or overexpression on chemoresistance, metastasis, and CSC phenotype. Furthermore, co-expression of sCLU and β-catenin in HCC tissues indicated poor prognosis of HCC patients.ConclusionsTaken together, the oncogenic sCLU might promote CSC phenotype via activating AKT/GSK3β/β-catenin axis, suggesting that sCLU was a potential molecular-target for HCC therapy.

The aim of the study was to investigate the expression of sCLU in relation to the clinicopathological features and prognosis of patients with untreated High-Grade Osteosarcoma (HGOS) and to evaluate sCLU as a target for osteosarcoma (OS) therapies. The expression of sCLU in 98 patients of HGOS enrolled from April 2005 to March 2015 at the affiliated hospital of Qingdao University was evaluated by immunohistochemistry. The sCLU expression, clinical data and survival were compared. siRNA-mediated sCLU gene silencing on cell apoptosis, viability, invasion and chemosensitivity to doxorubicin in U2OS cells in vitro was evaluated. sCLU expression was found in 59 (60%) of the 98 patients. A positive correlation was observed between sCLU expression and metastatic disease (P = 0.036) and a negative correlation between sCLU expression and response to chemotherapy (P = 0.002). Targeting sCLU expression in U2OS cells induced significant reduction in cellular growth and higher rates of spontaneous endogenous apoptosis. In addition, targeting sCLU expression inhibited the invasion of U2OS cells. Furthermore, targeting sCLU expression significantly sensitized to chemotherapeutic drug, doxorubicin. The overexpression of sCLU was significantly correlated with metastasis and chemosensitivity in patients with HGOS. sCLU may be a promising therapeutic or chemopreventive target for human OS treatment.

ABSTRACT Recent focus has turned to secretory clusterin (sCLU) as a key contributor to chemoresistance of anticancer agents, but the role of sCLU on chemotherapy drug response to gastric cancer cells is not fully understood. Previous research found that sCLU was overexpressed in the induced multidrug-resistant MGC-803/5-FU cell line, suggesting that sCLU upregulation was closely related to chemoresistance to anticancer agents. In the present study, we aimed to clarify the role and mechanisms of sCLU in regulating the chemoresistance of gastric cancer cells. Cell apoptosis and cell viability were evaluated by annexin V/propidium iodide staining and CCK8. Expression of sCLU and miR-195-5P was detected using quantitative RT-PCR assays. The expression of sCLU in gastric cancer tissues was detected by RT-PCR assays. Upregulating or downregulating sCLU or miR-195-5P in gastric cancer cells was used to evaluate the mechanisms of chemoresistance. We found that sCLU was significantly elevated in the MGC-803/5-FU and SGC-7901 cells, and the downregulating sCLU sensitized MGC-803/5-FU and SGC-7901 cells to cisplatin and Docetaxel by upregulation of miR-195-5P. Upregulating sCLU in MGC-803 and HGC-27 cells was resistant to cisplatin and Docetaxel by downregulating miR-195-5p. Targeting miR-195-5P reduced the sensitivity of MGC-803 cells to 5-FU, and miR-195-5P overexpression enhanced the sensitivity of MGC-803/5-FU cells to 5-FU. The overexpression of sCLU in gastric cancer tissues was associated with chemoresistance. Our findings suggest that overexpression of sCLU induced chemoresistance in gastric cancer cells by downregulating miR-195-5p, thus providing a potential target for the development of agents that targeting sCLU for gastric cancer therapy.

ABSTRACT Osteosarcoma (OS) is the most common primary malignant bone tumor. Secretory apolipoprotein J/clusterin (sCLU) is overexpressed in many cancers; however, its role in OS has not been previously investigated. The objectives of this study were to address this question and also to assess the clinical value of sCLU as a prognostic biomarker and therapeutic target by comparing sCLU expression in human OS (n = 106), normal bone (n = 16), fibrous dysplasia (n = 9), and ossifying myositis (n = 11) tissues and by evaluating the effect of sCLU silencing on OS growth, invasion, and chemosensitivity in vitro and in vivo. We found that sCLU was highly expressed in OS tissue specimens, which was positively correlated with metastatic disease and negatively correlated with response to chemotherapy. sCLU knockdown in KHOS cells inhibited proliferation and invasion and increased apoptosis as well as sensitivity to the chemotherapy drug gemcitabine (Gem). In a mouse xenograft model, sCLU depletion suppressed lung metastasis and enhanced the effects of Gem, thereby slowing KHOS tumor growth. These results indicate that sCLU overexpression is a biomarker for malignant transformation of OS and that therapeutic strategies targeting sCLU may be an effective treatment for OS. Highlights ● Secretory apolipoprotein J/clusterin (sCLU) is overexpressed in osteosarcoma (OS). ● sCLU overexpression is associated with metastasis and chemoresistance. ● Silencing sCLU inhibits metastasis and enhances chemosensitivity in OS cells. sCLU is a biomarker for metastatic OS and a potential therapeutic target.

Secretory clusterin (sCLU) is a small stress-induced cytoprotective chaperone protein. Its biological functions are similar to those of a heat-shock protein. The sCLU plays a crucial role in cell proliferation, multiple drug resistance, metastasis, and tumor progression. Abnormal sCLU expression in tumor tissues or sera of patients with primary hepatic cancer has been considered a useful biomarker for diagnosis and surveillance. However, the exact relationship between sCLU overexpression and malignant transformation of hepatocytes is still unknown. The present review examines some novel advances of the knowledge about the oncogenic role of sCLU in hepatocarcinogenesis.

Recurrence and metastasis are the two leading causes of poor prognosis in patients with hepatocellular carcinoma (HCC). Secreted clusterin (sCLU) is a stress-induced chaperone that is overexpressed in HCC. However, the precise molecular mechanisms of sCLU in HCC invasion and migration are largely unknown. In the present study, it was indicated that downregulation of sCLU significantly alleviated invasiveness whereas overexpression of sCLU notably enhanced the number of invasive cells via mediating the expression level of MMP-2 and E-cadherin in Bel-7402 and SMMC-7721 cells. Furthermore, as an important mediator of invasiveness, sCLU may be responsible for proliferation and invasion suppression induced by meloxicam (a selective inhibitor of cyclooxygenase-2) in HCC cells. The combination of meloxicam and CLU shRNA significantly decreased invasion in HCC cells in vitro. Furthermore, it was observed that overexpression of sCLU significantly potentiated expression of p-AKT and MMP-2. However, downregulation of sCLU by CLU shRNA alleviated the extent of p-AKT. These results suggest the targeting of sCLU may be a novel therapeutic strategy against invasion and migration in HCC.

Purpose: Systemic therapy has often been used for patients with advanced hepatocellular carcinoma (HCC). However, due to drug resistance, the use of cytotoxic chemotherapy in the treatment of patients with advanced HCC has typically demonstrated low response rates. Secretory clusterin (sCLU) is expressed in aggressive late-stage tumors and associated with resistance to chemotherapy, including that in HCC cases. The present research aimed to investigate the biological role of sCLU in HCC.Methods: sCLU expression in HCC and normal tissues was examined using immunohistochemical staining, followed by analysis of the correlation between sCLU expression and clinical indicators. In addition, the role and internal mechanism of sCLU in cell proliferation and apoptosis were investigated in HCC cells.Results: sCLU expression was significantly upregulated in HCC tissues; and was associated with histological grade and poor overall survival. The levels of sCLU were significantly increased in Bel7402, SMMC7721 and resistant HCC cells (Bel7404-OR). Inhibiting the activity of sCLU enhanced the chemosensitivity of Bel7402 and SMMC7721 cells. Downregulation of sCLU could increase the expression of Gadd45a in HCC cells. Overexpression of sCLU contributed to drug resistance in Bel7402, SMMC7721 and Bel7404-OR cells; whereas, overexpression of Gadd45a alone overcame drug resistance in the cells above. No significant expression changes of sCLU and Gadd45a were observed in HCC cells after the interference of a selective inhibitor of the PI3K/Akt signaling pathway. However, regulation of the expression of Gadd45a could influence the phosphorylation level of Akt; and further regulate the expression of Bcl-2 and Bax proteins involved in the mitochondrial apoptosis pathways.Conclusions: The results demonstrate that sCLU/Gadd45a/PI3K/Akt signaling represents a novel pathway that could regulate drug resistance in a one-way manner in HCC cells.

During prostate cancer progression cancer cells undergo a variety of molecular alterations that lead to the acquisition of uncontrolled growth properties. One such set of molecular alterations is mediated by the PI3K/Akt signaling pathway. Here, we describe a regulatory system that modulates the phosphoinosited 3-kinase/Akt (PI3K/Akt) pathway downstream of secreted Clusterin (sCLU) in normal and cancer prostate cells. The overexpression of sCLU is very frequent in prostate cancer, and can lead to Akt-activation. This prompted us to investigate how sCLU overexpression influences PI3K/Akt signaling network in a study model represented by human epithelial prostate PNT1A cells stably transfected with sCLU or with empty vector alone. We found that CLU cells show a marked differential phosphorylation of several members of the PI3K/Akt cascade, and in particular of Akt2. Moreover, we found that the phosphatase PHLPP1, known to dephosphorylate Akt2 at S473, is severely downregulated in CLU compared to MOCK cells. We thus investigated whether sCLU alters PHLPP1 protein stability or expression. Our results indicate that sCLU indeed stimulates PHLPP1 degradation by β-TrCP. Interestingly, we further demonstrated that sCLU alters also PHLPP1 through the negative regulator miR-190. Next, because sCLU has been reported to inhibit or to stimulate the aggressive behavior of cancer cells depending on the cell model, we investigated the effects of CLU overexpression or addition of recombinant Clusterin to the medium on cell migration and invasion in PNT1A cell line, which is not expected to display an invasive phenotype, and in the cancer prostate epithelial cell lines LNCaP and PC3. The result was extremely clear: not only CLU overexpression gives PNT1A cells the same behavior of wild-type PC3 cells, but also increases the migration and invasion index of all the above cell models by two to four times, compared to controls. As a confirmation, in the same model silencing of Clusterin abrogates migration of CLU cells. Next, the effect of Akt single-isoform silencing on cell migration was explored. While silencing of Akt1 affected migration only slightly, silencing of Akt2 prevented migration of both MOCK and CLU cells completely. The same result was obtained by pharmacological inhibition of Akt2. All together our results, clearly demonstrate for the first time that Clusterin can switch the low migration phenotype of normal prostate cells towards a high migration phenotype through the modulation of the expression of the PHLPP1 and, in turn, the activity of Akt2.

Ku70, Ku80, and sClusterin: A Cluster of Predicting Factors for Response to Neoadjuvant Chemoradiation Therapy in Patients With Locally Advanced Rectal Cancer

BackgroundIn a previous analysis using a lung cancer cell line model, we have found that therapies directed against secreted clusterin (sCLU) and its downstream signaling targets pAkt and pERK1/2 may have the potential to enhance the efficacy of cisplatin (DDP)-based chemotherapy in vitro. Here, we investigated the therapies directed against sCLU on the DDP-based chemotherapy in vivo and explored the mechanism.MethodsUsing lung cancer cell lines, A549 cells and DDP-resistant A549 cells (A549DDP), we determined the effect of sCLU silencing using short interfering double-stranded RNA (siRNA) on chemosensitivity in immunocompromised mice bearing A549DDP tumors. We then determined the effect of sCLU overexpression via stable sCLU transfection on chemosensitivity in immunocompromised mice bearing A549 tumors. The effect of sCLU silencing or overexpression on pAkt and pERK1/2 expression and chemosensitivity in vivo was detected by Western blot assay.ResultsThe results showed sCLU silencing increased the chemosensitivity of A549DDP cells to DDP in vivo via downregulation of pAkt and pERK1/2 expression. And sCLU overexpression decreased the chemosensitivity of A549 cells to DDP in vivo via upregulation of pAkt and pERK1/2 expression.ConclusionsWe therefore concluded that the DDP-induced sCLU activation, which involved induction of pAkt and pERK1/2 activation that confer DDP resistance in immunocompromised mice and alteration of this balance, allows sensitization to the antitumor activity of cisplatin chemotherapy.

BackgroundSeveral studies have shown that secreted clusterin (sCLU) up-regulation in multi-drug resistant osteosarcoma (OS) cells relates to enhanced drug resistance. Furthermore, sCLU silencing directed against sCLU induces significant reduction of cellular growth and sensitizes OS cells to chemotherapy. However, the molecular mechanisms underlying the effect of sCLU on OS cells are not known.MethodsTo evaluate the roles and possible mechanisms of sCLU in chemoresistance of OS cells to cisplatin (DPP), we utilized RNA interference to knockdown sCLU expression in the sCLU-rich U-2 OS cells and to overexpress sCLU in the sCLU-poorer KH OS cells, and further assessed the cell viability and chemosensitivity to DDP as well as possible signaling transduction pathways.ResultsThe data showed that sCLU depletion inhibited growth and sensitized sCLU-rich U-2 OS cells to cisplatin in vitro and in vivo by inducing inactivation of ERK1/2, and sCLU overexpression promoted growth and increased resistance of sCLU-less KH OS cells to cisplatin in vitro and in vivo by activation of ERK1/2.ConclusionsThe data also suggests critical roles of sCLU in OS cell chemoresistance to DPP and raises the possibility of sCLU depletion as a promising approach to OS therapy.

The purpose of this study was to investigate whether the therapeutic activity of gemcitabine (GCB) in hepatocellular carcinoma (HCC) could be increased by the down-regulation of secretory clusterin (sCLU), a glycoprotein that is considered to play a cytoprotective role in the resistance to chemotherapy. The expression of sCLU was detected in HCC tumor tissues and cell lines. A cell viability and apoptosis assay were performed in parental HCC cells or the same cells transfected with sCLU shRNA and treated with or without GCB. The potential downstream pathways were investigated using the Human Apoptosis RT(2) Profiler™ PCR Array. The expression levels of sCLU in HCC tissues were significantly higher than in adjacent non-tumor liver tissues and were associated with the histological grade and transarterial chemoembolization. sCLU overexpression was also found in three HCC cell lines and hepatocytes. The depletion of sCLU synergistically increased GCB sensitivity in Bel7402 and SMMC7721 cells and induced cell apoptosis. Based on the PCR array analysis, sCLU depletion also resulted in the up-regulation of BNIP1, GADD45A, TNFRSF10A, and TRADD and down-regulation of AKT1 in Bel7402 and SMMC7721 cells compared with the parental controls. These results were further supported by a Western blot analysis, which showed increased GADD45a protein expression and the decreased expression of phosphorylated AKT. GADD45a overexpression also increased the sensitivity to GCB in the Bel7402 and SMMC7721 cells. Targeting sCLU may be a useful method to enhance the cytotoxic effect of GCB in hepatocellular carcinoma.

Several studies have shown Secreted Clusterin (sCLU) silencing directed against sCLU mRNA in sCLU-rich lung cancer cell lines sensitized cells to chemotherapy. However, the molecular mechanisms underlying the effect of sCLU silencing on lung cancer cell chemosensitivity is not known. In the present study, we aimed to determine that vector expressing short hairpin RNA against sCLU RNA (sCLU-shRNA) enhances the chemosensitivity in human small cell lung cancer A549 cells in vitro by inhibition of phosphorylated ERK1/2 (p-ERK1/2) and Akt (p-Akt). The pCDNA3, 1-sCLU and control scrambled pCDNA3. 1 plaismid was constructed. We investigated the effects of sCLU overexpression by pCDNA3. 1-sCLU transfection on chemosensitivity to cisplatin (DDP) in A549 cells in vitro. We down-regulated sCLU expression by short hairpin RNA against sCLU RNA (sCLU-shRNA) and investigated the effects on chemosensitivity to DDP in A549 cells and A549DDP in vitro. In order to confirm the correlation between sCLU and AKT and ERK1/2 signals, cells were treated with wortmannin and U0126. We found the chemotherapeutic agent DDP activated sCLU. Overexpression of sCLU increased cellular DDP chemoresistance in the A549DDP and pCDNA3. 1-sCLU transfected A549 cells via inhibition DDP-induced apoptosis.Whereas sCLU knockdown induced chemosensitization in the S549 and A549DDP cells via increase of DDP-induced apoptosis. sCLU overexpression activated pAkt Ser473 and pERK1/2Thr202/Tyr204, and vice versa. Inhibition of pAkt Ser473 and pERK1/2Thr202/Tyr204 was sufficient to induce significant recovery in chemosensitivity to DDP in A549DDP in the presence of sCLU overexpression. The chemotherapeutic agent DDP activated sCLU, which directly regulated pAkt and pERK1/2. This novel finding suggests that therapies directed against sCLU and its downstream signaling targets pAkt and pERK1/2 may have the potential to enhance the efficacy of DDP-based chemotherapy.

Background/Aims: Several studies have shown secreted clusterin (sCLU) silencing directed against sCLU mRNA in sCLU-rich lung cancer cell lines sensitized cells to chemotherapy. However, the molecular mechanisms underlying the effect of sCLU silencing on lung cancer cell chemosensitivity is not known. In the present study, we aimed to determine that vector expressing short hairpin RNA against sCLU RNA (sCLU-shRNA) enhances the chemosensitivity in human small cell lung cancer A549 cells in vitro by inhibition of phosphorylated ERK1/2 (p-ERK1/2) and Akt (p-Akt). Methods: The pCDNA3.1-sCLU and control scrambled pCDNA3.1 plasmid was constructed. We investigated the effects of sCLU overexpression by pCDNA3.1-sCLU transfection on chemosensitivity to cisplatin (DDP) in A549 cells in vitro. We down-regulated sCLU expression by short hairpin RNA against sCLU RNA (sCLU-shRNA) and investigated the effects on chemosensitivity to DDP in A549 cells and A549^DDPin vitro. In order to confirm the correlation between sCLU and AKT and ERK1/2 signals, cells were treated with wortmannin and U0126. Results: We found the chemotherapeutic agent DDP activated sCLU. Overexpression of sCLU increased cellular DDP chemoresistance in the A549^DDP and pCDNA3. 1-sCLU transfected A549 cells via inhibition DDP-induced apoptosis. Whereas sCLU knockdown induced chemosensitization in the S549 and A549^DDP cells via increase of DDP-induced apoptosis. sCLU overexpression activated pAKT Ser⁴⁷³ and pERK1/2^{Thr202/Tyr204}, and vice versa. Inhibition of pAKT Ser⁴⁷³ and pERK1/2^{Thr202/Tyr204} was sufficient to induce significant recover y in chemosensitivity to DDP in A549^DDP in the presence of sCLU overexpression. The DDP activated sCLU, which directly regulated pAKT and pERK1/2. Conclusions: This novel finding suggests that therapies directed against sCLU and its downstream signaling targets pAKT and pERK1/2 may have the potential to enhance the efficacy of DDP-based chemotherapy.

Secretory clusterin (sCLU) is expressed in numerous cancers and is associated with the resistance to chemotherapy. However, the role of sCLU in the resistance of hepatocellular carcinoma (HCC) to oxaliplatin (OXA), a recently used third-generation platinum agent, remains unclear. The stable transfectants that are depleted of or overexpress sCLU and OXA-resistant cells were generated using human HCC cells. Overexpression of sCLU abrogated OXA-induced inhibition of cell growth and cell apoptosis, but depletion of sCLU synergized with OXA to inhibit cell growth and enhance cell apoptosis, by regulating proteins involved in mitochondrial apoptosis pathways, such as Bcl-2, Bax, Bcl-xL and caspase-9, and affecting phosphorylation of Akt and GSK-3β. Overexpression of sCLU in either OXA-resistant cells or stable transfectants that overexpress sCLU significantly increased phosphorylated Akt. However, specific inhibition of Akt enhanced sensitivity of sCLU-overexpressing cells to OXA, but had no effect on sCLU expression, suggesting that the regulatory effects between sCLU and pAkt may be in a one-way manner in HCC cells. The expression levels of sCLU affected the therapeutic efficacy of OXA to treat HCC tumors established in immunodeficiency mice. The results have demonstrated that sCLU contributes to OXA resistance by activating Akt pathway, indicating that sCLU may be a novel molecular target for overcoming OXA resistance in HCC.

Secretory clusterin (sClu) is an anti-apoptotic protein that plays a role in protecting cells from Tumour-necrosis factor (TNF)-alpha-induced apoptosis. The aim of the present study was to investigate the molecular mechanisms underlying the effect of sClu on TNF-alpha-induced apoptosis in breast cancer cells. The wild-type p53 expressing MCF-7 cell line was engineered to overexpress sClu (MCF-7/sClu), whereas the MDA-MB-231 cell line with mutant p53 was transfected with a sClu silencing siRNA (MDA-MB-231/sClu siRNA). The effects of clusterin overexpression and downregulation on apoptosis and sensitivity to TNF-alpha were examined in vitro. Our results showed that TNF-alpha treatment increased Bcl-2 mRNA and protein levels in breast cancer cells, suggesting that Bcl-2 is directly regulated by nuclear factor-kappaB (NF-kappaB) in response to TNF-alpha. The induction of Bcl-2 was mediated by the p65 subunit of NF-kappaB. siRNA-mediated silencing of Bcl-2 led to a significant increase in TNF-alpha-induced apoptosis. Silencing of sClu in MDA-MB-231/sClu siRNA cells abrogated TNF-alpha-mediated NF-kappaB activation and Bcl-2 overexpression, and rendered the MDA-MB-231/sClu siRNA cells significantly more sensitive to TNF-alpha-mediated apoptosis than the parental cells. Furthermore, overexpression of sClu in MCF-7/sClu cells promoted TNF-alpha-mediated NF-kappaB activity and Bcl-2 overexpression, and rendered the MCF-7/Clu cells significantly more resistant to TNF-alpha-mediated apoptosis. Inhibition of NF-kappaB activity or p65 and Bcl-2 expression reversed these effects. The present results suggested that sClu confers breast cancer cells resistance to TNF-alpha-induced apoptosis through NF-kappaB activation and Bcl-2 overexpression.

Tumor-derived secretory clusterin induces epithelial–mesenchymal transition and facilitates hepatocellular carcinoma metastasis

Secreted clusterin (sCLU) has been shown to be overexpressed in metastatic hepatocellular carcinoma (HCC) tissue, and its overexpression in HCC cells increases cell migration and the formation of liver metastatic tumor nodules in vivo. In this study, we tested the hypothesis that sCLU plays a role in the invasiveness of human HCC and may be associated with its metastatic spread. HCCLM3, a human hepatocellular carcinoma cell line, was transiently transfected with an antisense oligonucleotide (ASO) against sCLU (OGX-011). HepG2 liver hepatocellular cells were transiently transfected with the pc.DNA3.1-sCLU plasmid to overexpress sCLU, and subsequently evaluated for effects on invasion and the expression of molecules involved in invasion. We observed that suppression of the sCLU gene significantly reduced the invasive capability of the highly invasive HCCLM3 cells, and vice versa in the low invasive HepG2 cell line. The results revealed that knockdown of sCLU by OGX-011 resulted in a significant increase in the expression of E-cadherin and a decrease in matrix metalloproteinase-2 (MMP-2) gene transcription. Overexpression of sCLU by transfection with pc.DNA3.1-sCLU significantly decreased the expression of E-cadherin and increased MMP-2 gene transcription. These data were further verified by reverse transcription-PCR and Western blot analysis. A significant reduction in MMP-2 expression and an increase in E-cadherin expression in sCLU-knockdown HCCLM3 cells were observed, as well as a significant increase in MMP-2 expression and a decrease in E-cadherin expression in HepG2 cells overexpressing sCLU. These data indicate a role for sCLU in augmenting MMP-2 transcription and decreasing E-cadherin expression. Our data show the involvement of sCLU in human HCC invasion, and demonstrate that silencing sCLU gene expression inhibits the invasion of human HCC cells by inhibiting MMP-2 expression and promoting E-cadherin expression. Thus, OGX-011 could be an effective therapeutic agent for HCC.