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MicroRNAs regulate gene expression at the posttranscriptional level and play important roles in tumor development, progression, and metastasis. The aim of this study was to investigate the role of microRNA-92a (miR-92a) in metastasis of colorectal cancer (CRC).One hundred fifty-eight CRC patients were enrolled. The expression of miR-92a, PTEN, and E-cadherin was analyzed by real-time PCR. Univariate (Kaplan-Meier) analysis was used to analyze primary outcomes included 5-year overall survival and tumor recurrence. CRC cell model studies were used to analyze the miR-92a-involved CRC metastasis.The expression of miR-92a in tumor tissues was significantly positively correlated with lymph node metastasis in CRC patients (p = 0.012). After adjusting for age, sex, and disease differentiation, this correlation remained significant (p = 0.01). In addition, there was a negative correlation between levels of miR-92a and the PTEN gene (p 0.0001). No any association of miR-92a and E-cadherin was found (p = 0.128). Patients with high miR-92a/low PTEN had poorer overall survival and disease-free survival rates than those with high miR-92a/high PTEN, low miR-92a/high PTEN, and low miR-92a/low PTEN. The association of levels of miR-92a and PTEN with tumor cell migration in CRC was also confirmed in CRC cell models.We suggest that miR-92a is involved in lymph node metastasis of CRC patients through PTEN-regulated PI3K/AKT signaling pathway.

Glucose-regulated protein 78 (GRP78) plays an important role in embryonic development and cancer progression. However, there is little information regarding the regulation of GRP78 in hepatocellular carcinoma (HCC) metastasis.We used RNA silencing and cDNA expression vectors to manipulate target gene expression in HCC cells. The transwell migration assay and xCelligence biosensor system were applied to determine the proliferatory and migratory ability of the HCC cells.In this study, we found that GRP78 silencing enhanced cell migration in both HepJ5 and Mahlavu cells. Overexpressed GRP78 in skHep1 cells suppressed the migratory ability. In the insight mechanism dissection for GRP78-mediated cancer migration, we found that downregulation of GRP78 caused the increase of vimentin expression on HCC cells. Suppressed vimentin expression also decreased the migratory ability on HCC, indicating that vimentin expression levels modulated the cell migratory ability.We found that silencing GRP78 in HCC cells may enhance cell migration through the increase of vimentin expression.

Survivin has multiple functions during the progression of cancer. However, the role of survivin in the progression and metastasis of hepatocellular carcinoma (HCC) remains unknown. Survivin expression in HCC cells (Mahlavu and Hep3B) was assessed using reverse transcription real-time PCR and Western blot analyses. In addition, survivin expression in HCC cells was manipulated using small interfering RNA (siRNA) or overexpression and proliferation and transwell migration assays were performed to monitor the effect of manipulated survivin expression on the growth rate and migratory ability of the transfected cells. Among the HCC cell lines tested, we found high endogenous expression of survivin mRNA and protein in Mahlavu cells. After silencing survivin expression in Mahlavu cells, there was a dramatic decrease in the cell growth rate and an increase in the metastatic potential of the cells. Overexpression of survivin in Hep3B cells suppressed the ability of the cell to migrate. The mechanism of enhanced cell migration caused by decreased survivin expression is mediated through the downregulation of glucose-regulated protein 78 (GRP78) and the upregulation of the epithelial-mesenchymal transition (EMT) marker, vimentin. Survivin may mediate metastasis in HCC. The knockdown of survivin expression may enhance cancer metastasis through the downregulation of GRP78 and upregulation of vimentin expression.

Glucose-regulated protein 78 (GRP78) plays an important role in the therapeutic treatment and progression of cancer. However, little is known about the effect of GRP78 expression to curcumin in hepatocellular carcinoma (HCC). In this study, we generated GRP78 knockdown cells (GRP78KD) by a short interfering RNA (siRNA) technique. The antiproliferation effects of curcumin were determined by MTT assay, TUNEL assay, and cell cycle determination. We found that GRP78KD cells were more resistant to curcumin treatment compared with the parental cells in MTT assay. The apoptosis cell population was increased in scrambled-siRNA cells treated with curcumin compared with GRP78KD cells in cell cycle distribution and TUNEL assays. Finally, we found that knocking down GRP78 causes resistance to curcumin treatment through the suppression of caspase-3 and caspase-8 expression levels. We conclude that the expression level of GRP78 may contribute to the therapeutic effect of curcumin on HCC cells.

Survivin is a potential therapeutic target for cancer. Increased survivin expression promotes cell survival and therapeutic resistance. However, there is little information regarding whether the expression level of survivin affects curcumin treatment in hepatocellular carcinoma (HCC). Survivin expression was suppressed in HCC cells using a short interfering RNA (siRNA) technique. The anticancer effects of curcumin were examined using a biosensor system, MTT assay, TUNEL assay, and cell cycle analysis. Curcumin resistance developed in cells with suppressed survivin, in contrast to the parental cells, as determined by survival assays. Cell cycle analysis and TUNEL assays revealed that the apoptotic cell population was increased in the scrambled-siRNA cells treated with curcumin compared with the survivin-siRNA cells. Suppression of survivin expression resulted in curcumin resistance via the modulation of Bcl-2 and Bax expression. We conclude that the expression levels of survivin may mediate the therapeutic efficacy of curcumin in HCC cells.

In this study, we intended to dissect the mechanism of 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-enhanced migration of gastric cancer. Smoking has been defined as a risk factor for gastric cancer. Tobacco-specific carcinogen, NNK, was reported to enhance cancer progression in gastric cancer. Currently, metastasis is the major issue for clinical cancer therapy, but the influence of NNK on the migration of gastric cancer remains to be determined. The expression of nicotinic receptor in gastric cancer cells was identified by real-time polymerase chain reaction and Western blotting. The influence of NNK on migration of gastric cancer cells was evaluated by the transwell migration assay system. Receptor-mediated migration was studied by both inhibitor and small interfering RNA. Alpha7 nicotinic acetylcholine receptor, alpha7-nicotinic acetylcholine receptor (nAChR), was identified higher than alpha9-nAChR in gastric cancer cell lines, AGS cells. NNK enhanced significantly gastric cancer cell migration in transwell assay. We used inhibitor and siRNA to demonstrate that alpha7-nAChR mediated NNK-enhanced gastric cancer cell migration and upregulation of fibronectin were involved in NNK-enhanced migration of gastric cancer cells. Finally, we found that silenced fibronectin expression level inhibited the migratory ability in AGS cells. NNK enhanced gastric cancer metastasis through alpha7-nAChR and fibronectin—one of the hallmarks of epithelial mesenchymal transition.

Survivin is an antiapoptotic molecule that is widely expressed in cancers, including hepatocellular carcinoma (HCC). Survivin has become a general therapeutic target for cancers because of its selective overexpression in a majority of tumors. However, little is known regarding the effect of survivin expression in combination with gemcitabine on HCC.We generated survivin knockdown cells (survivin-KD) via a short interfering RNA (siRNA) technique. The antiproliferation effects of gemcitabine were determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, TUNEL (terminal deoxynucleotidyl transferase dUTP nick-end labeling) assay, and cell cycle evaluation.According to the MTT assay, we found that survivin-KD cells were more sensitive than parental cells and scrambled control cells to gemcitabine treatment. The apoptotic cell population increased in survivin-KD cells that were treated with gemcitabine in comparison to scrambled control cells, as observed by the cell cycle distribution and TUNEL assays. We found that survivin knockdown resulted in a reduction of glucose-regulated protein 78 (GRP78), which may be responsible for the observed increased survivin-KD cell sensitivity to gemcitabine.We conclude that survivin knockdown may contribute to a therapeutic effect of gemcitabine through GRP78 on HCC cells.

MicroRNAs (miRNAs) play an essential role in mediating gene expression in both normal and malignant cells. However, little is known about specific miRNAs during the development of hepatocellular carcinoma (HCC) from well-differentiated to poorly differentiated cells.We performed miRNA array analysis of three different HCC cell lines: HepG2, HepJ5, and skHep-1. The expression patterns of miR-200 family members were confirmed by real-time polymerase chain reaction (PCR). We overexpressed miR-200 family members by using a lentivirus system and selected for stably transduced cells using antibiotics. The migration ability of the cells was tested using the Transwell migration assay system.Our miRNA array and real-time PCR results indicated a decrease in the expression of miR-200 family members in poorly differentiated skHep-1 cells compared with well-differentiated HepG2 cells. We overexpressed miR-200a and miR-200b in both HepJ5 and skHep-1 cells and found that the overexpression of the miR-200 family members did not influence proliferation, although migration was decreased in these cells. We found that overexpression of miR-200 family members led to an upregulation of E-cadherin expression in both HepJ5 and skHep-1 cells. Furthermore, we silenced E-cadherin expression by shRNA in miR200a-HepJ5 cells and found that the migratory ability of these cells was enhanced upon the decrease in E-cadherin expression.Members of the miR-200 family (miR-200a and miR-200b) play important roles in HCC migration by regulating E-cadherin expression.

The objective was to study the mechanism of nicotine-enhanced migration of gastric cancer cells. Long-term cigarette smoking increases the risk of gastric cancer mortality. Tobacco-specific mitogen, nicotine, was reported to correlate with cancer progression on gastric cancer. Since metastasis is the major cause of cancer death, the influence of nicotine on the migration of gastric cancer cells remains to be determined.The influence of nicotine on migration of gastric cancer cells was evaluated by transwell assay and wound-healing migration assay. Receptor-mediated migration was studied by both inhibitor and small interfering RNA.Alpha7 nicotinic acetylcholine receptor, alpha7-nAChR, was identified in gastric cancer cell lines, AGS cells. Nicotine enhanced AGS cell migration in transwell assay and wound-healing migration assay in a dose-dependent manner. We used inhibitor and siRNA to demonstrate that alpha7-nAChR mediated nicotine-enhanced gastric cancer cell migration through downregulation E-cadherin and upregulation ZEB-1 and snail.Tobacco-specific mitogen, nicotine, enhanced gastric cancer metastasis through alpha7-nAChR and suppression of E-cadherin level-one of the hallmarks of epithelial to mesenchymal transition. Therefore, patients with gastric cancer should avoid smoking.

Long-term cigarette smoking increases the risk of colorectal cancer mortality. Tobacco’s addictive toxin, nicotine, was reported to increase DNA synthesis of colon cancer cells. Because metastasis is the major cause of cancer death, the influence of nicotine on the migration of colon cancer cells remains to be determined. The influence of nicotine on the migration of colon cancer cells was evaluated using transwell assay. Nicotine receptor-mediated migration was studied by using both inhibitors and small interfering RNA (siRNA). The role of COX-2 signal was studied using pharmacological inhibitors. The expression of epithelial mesenchymal transition (EMT) marker and COX-2 signal was evaluated using real-time polymerase chain reaction (PCR). Nicotine enhanced DLD-1 and SW480 cell migration in a dose-dependent manner. We used inhibitors and siRNA to demonstrate that α7-nAChR mediates nicotine-enhanced colon cancer cell migration and upregulates fibronectin expression, which is involved in nicotine-enhanced migration. Furthermore, COX-2 signal was induced by nicotine treatment and is involved in nicotine-enhanced fibronectin expression. Nicotine, tobacco’s additive toxin, enhances colon cancer metastasis through α7-nAChR and fibronectin—a mesenchymal marker for epithelial mesenchymal transition. Furthermore, COX-2 signal was involved in the induction of fibronectin. Therefore, smoking may play role in the progression of colon cancer.

Thrombomodulin (TM) is a key molecule mediating circulation homeostasis through its binding to thrombin. The TM–thrombin complex can activate protein C and thrombin-activatable fibrinolysis inhibitor to form a tight clot. In many cancer tissues, decrease of TM expression may correlate with cancer metastasis. However, the role of TM in hepatocellular carcinoma (HCC) progression is still unclear. We characterized TM expression in HCC cells (HepJ5 and skHep-1 cells) using real-time polymerase chain reaction (PCR) and Western blotting. We then manipulated TM expression using both TM-specific short hairpin RNA (shRNA) and overexpressing it in HCC cells. Transwell migration assay was performed to monitor the migratory ability of HCC cells under different levels of TM expression. We found that TM was ectopically highly expressed in skHep-1 at both transcriptional and translational levels. After silencing TM expression in skHep-1 cells, we found that metastatic capability was dramatically increased. Conversely, overexpression of TM in HepJ5 cells decreased metastatic ability. We investigated the possible mechanism and found that decreased TM-mediated enhancement of cell migration was dependent on upregulation of ZEB1, a repressor of E-cadherin. TM may be a modulator of cancer metastasis in HCC. Downregulation of TM expression may increase ZEB1 and decrease E-cadherin levels.

GRP78 plays an essential role in embryonic development and in the therapeutic treatment and progression of cancer. However, little is known about the role of GRP78 in hepatocellular carcinoma (HCC).In this study, we characterized five different HCC cell lines to examine GRP78 expression patterns and found that only HepJ5 cells ectopically overexpress GRP78. We knocked down GRP78 expression in HepJ5 cells using a small interfering RNA (siRNA), and the proliferation assay and migration assay were performed.Using siRNA technique, we could successfully reduce GRP78 expression levels in HepJ5 cells. In a cell growth study, we found that GRP78-siRNA caused no significant changes in cellular proliferation in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), colony formation, and cell cycle distribution. In a cell migration study, we found that GRP78-siRNA HepJ5 cells had dramatically increased migration ability in Transwell assay.We conclude that ectopically expressed GRP78 does not contribute to the increased proliferation of HepJ5 cells, but does correlate with the migration of HCC cells under normoxic conditions.

Sorafenib is a newly established cancer drug found to be an effective systemic treatment for advanced hepatocellular carcinoma (HCC). However, little is known about any potential effectors that modify tumor cell sensitivity towards sorafenib. Here, we present the first evidence that glucose-regulated protein 78 (GRP78) is intimately associated with acquisition of resistance towards sorafenib.The role of GRP78 in acquisition of resistance towards sorafenib was determined using HepJ5 (a GRP78-overexpressing subline) and HepG2 as its pair-matched control. RNA interference in cancer cells was applied to determine the influence of GRP78 expression on sensitivity to sorafenib treatment.We found that HepG2 cells exhibited higher sensitivity toward sorafenib, with 50% inhibition concentration (IC(50))20 microMu for HepJ5 and 4.8 microM for HepG2. Specifically, when HepG2 cells received 20 microM sorafenib treatment for 24 h, over 80% of cells underwent apoptosis compared with only 32% of HepJ5 cells under similar experimental conditions. Similarly, GRP78 knockdown in HepJ5 cells by small interfering RNA (siRNA) technique enhanced the efficacy of sorafenib-mediated cell death. This was reflected by a shift of IC(50) values from20 microM to 4.8 microM.GRP78 is a positive modifier for sorafenib resistance acquisition in HCC and represents a prime target for overcoming sorafenib resistance.