Prospero homeobox 1 mediates the progression of gastric cancer by inducing tumor cell proliferation and lymphangiogenesis.

BACKGROUND: Prospero homeobox 1 (PROX1) functions as a tumor suppressor gene or an oncogene in various cancer types. However, the distinct function of PROX1 in gastric cancer is unclear. We determined whether PROX1 affected the oncogenic behavior of gastric cancer cells and investigated its prognostic value in patients with gastric cancer. METHODS: A small interfering RNA against PROX1 was used to silence PROX1 expression in gastric cancer cell lines AGS and SNU638. Expression of PROX1 in gastric cancer tissues was investigated by performing immunohistochemistry. Apoptosis, proliferation, angiogenesis, and lymphangiogenesis were determined by performing the TUNEL assay and immunohistochemical staining for Ki-67, CD34, and D2-40. RESULTS: PROX1 knockdown induced apoptosis by activating cleaved caspase-3, caspase-7, caspase-9, and poly(ADP-ribose) polymerase, and by decreasing the expression of anti-apoptotic proteins Bcl-2 and Bcl-xL. PROX1 knockdown also suppressed tumor cell proliferation. In addition, PROX1 knockdown decreased lymphatic endothelial cell invasion and tube formation and the expression of vascular endothelial growth factor (VEGF)-C and -D and cyclooxygenase (COX)-2. However, PROX1 knockdown only decreased umbilical vein endothelial cell invasion, not tube formation. The mean Ki-67 labeling index and lymphatic vessel density value of PROX1-positive tumors were significantly higher than those of PROX1-negative tumors. However, no significant difference was observed between PROX1 expression and apoptotic index or microvessel density. PROX1 expression was significantly associated with age, cell differentiation, lymph node metastasis, cancer stage, and poor survival. CONCLUSIONS: These results indicate that PROX1 mediates the progression of gastric cancer by inducing tumor cell proliferation and lymphangiogenesis.

SOX4 expression is associated with treatment failure and chemoradioresistance in oral squamous cell carcinoma.

BACKGROUND: In humans, sex-determining region-Y (SRY) related high-mobility-group box 4 (SOX4) is linked to development and tumorigenesis. SOX4 is over-expressed in several cancers and has prognostic significance. This study evaluated whether SOX4 affects oncogenic behavior and chemoradiotherapy response in head and neck squamous cell carcinoma (HNSCC) cells, and documented the relationship between its expression and prognosis in oral squamous cell carcinoma (OSCC). METHODS: We used small interfering RNA in HNSCC cells to evaluate the effect of SOX4 on cell proliferation, apoptosis, chemoradiation-induced apoptosis, invasion, and migration. SOX4 expression in OSCC tissues was investigated by immunohistochemistry. RESULTS: SOX4 knockdown (KO) decreased cell proliferation and induced apoptosis by activating caspases-3 and -7, and poly-ADP ribose polymerase and suppressing X-linked inhibitor of apoptosis protein in HNSCC cells; it also enhanced radiation/cisplatin-induced apoptosis; and suppressed tumor cell invasion and migration. Immunostaining showed SOX4 protein was significantly increased in OSCC tissues compared with adjacent normal mucosa. SOX4 expression was observed in 51.8 % of 85 OSCC tissues, and was significantly correlated with treatment failure (P = 0.032) and shorter overall survival (P = 0.036) in patients with OSCC. CONCLUSIONS: SOX4 may contribute to oncogenic phenotypes of HNSCC cells by promoting cell survival and causing chemoradioresistance. It could be a potential prognostic marker for OSCC.

Livin is associated with the invasive and oncogenic phenotypes of human hepatocellular carcinoma cells.

AIM: Livin, a member of the inhibitors of apoptosis proteins, is expressed in variable cancers, and its expression is considered a poor prognostic marker. The aims of this study were to observe the effect of Livin on the behaviors of hepatocellular carcinoma (HCC) cells and to evaluate its expression in HCC tissues and its relation to prognosis. METHODS: The biological effects of Livin on tumor cell behavior were investigated using siRNA in HepG2 and Chang cells. Migration, invasion and proliferation assays were performed. Flow cytometric analyses and western blotting were used to evaluate the impact of Livin on apoptosis and the cell cycle. In addition, western blotting and immunohistochemistry were used to investigate Livin expression in HCC tissues. RESULTS: Livin knockdown suppressed tumor cell migration, invasion and proliferation in HCC cells, and increased the proportion of apoptotic cells as compared with scrambled siRNA-transfected HCC cells. Furthermore, Livin knockdown resulted in the activation of caspases and increased apoptosis. In addition, Livin knockdown modulated cell cycle regulatory protein levels such as decrease of cyclins and cyclin-dependent kinase (CDK) level, and increase of CDK inhibitor (CDKI) level in HCC cells. The Livin protein level was significantly elevated in HCC tissues as compared with normal hepatic tissues. However, Livin expression was not found to be associated with clinicopathological parameters, which included patient survival. CONCLUSION: These results suggest that Livin is associated with invasive and oncogenic phenotypes of human HCC cells.

Impact of Prospero Homeobox-1 (PROX-1) οn the Oncogenic Phenotypes of Hepatocellular Carcinoma Cells.

BACKGROUND/AIM: Transcriptional factor prospero homeobox-1 (PROX-1) is crucial for the embryonic development of various organs and cell fate specification. It exhibits either an oncogenic or tumor suppressive activity depending on cancer types. However, the relationship between PROX-1 and hepatocellular carcinoma (HCC) remains obscure. This study was conducted to investigate the effect of PROX-1 on the invasive and oncogenic phenotypes of human HCC cells. MATERIALS AND METHODS: The effect of PROX-1 on tumor cell behavior was investigated by using a pcDNA-myc vector and a small interfering RNA in HepG2 and Huh7 human HCC cell lines. Flow cytometry, migration, invasion, proliferation, and tube formation assays were performed. PROX-1 expression in human HCC cells was explored by western blotting. RESULTS: PROX-1 overexpression enhanced tumor cell proliferation and inhibited apoptosis and cell cycle arrest by modulating the activities of caspase-3, PARP, and cyclin-dependent kinase inhibitors, including p21, p27, and p57 in HCC cells. After PROX-1 overexpression, the number of migrating and invading HCC cells significantly increased, and the expression levels of N-cadherin and Snail increased in HCC cells. PROX-1 overexpression enhanced angiogenesis through increased VEGF-A and VEGF-C expression and decreased angiostatin expression. PROX-1 overexpression also increased the phosphorylation of glycogen synthase kinase-3ß (GSK-3ß) and forkhead box O1 (FOXO1) in HCC cells. After PROX-1 knockdown, their phosphorylation was reversed. CONCLUSION: PROX-1 overexpression is associated with the invasive and oncogenic phenotypes of human HCC cells via GSK-3ß and FOXO1 phosphorylation.

Expression of an oxysterol-metabolizing enzyme in colorectal cancer and its relation to tumor cell behavior and prognosis.

Oxysterols and oxysterol-metabolizing enzymes have been implicated in the pathogenesis of various cancers. However, the distinct function of the oxysterol-metabolizing enzyme cytochrome P450 family 39 Subfamily A Member 1 (CYP39A1) in colorectal cancer (CRC) remains unclear. The aims of the current study were to evaluate whether CYP39A1 affects the oncogenic behaviors of CRC cells and to investigate the prognostic value of its expression in CRC. A CYP39A1 small-interfering RNA was used to block CYP39A1 gene expression in DLD1 and SW480 cells. The expression of CYP39A1 in CRC tissues was investigated by immunohistochemistry. Tumor angiogenesis and lymphangiogenesis were assessed by CD34 and D2-40 immunohistochemical staining, respectively. CYP39A1 knockdown inhibited tumor cell migration and invasion in DLD1 and SW480 cells. Angiogenesis was also inhibited through the decreased expression of vascular endothelial growth factor (VEGF)-A and hypoxia-inducible factor (HIF)-1α, and angiostatin and endostatin expression increased. In addition, CYP39A1 knockdown inhibited the lymphangiogenesis by decreasing the expression of VEGF-C. CYP39A1 expression was increased in CRC tissues compared with normal colorectal mucosa. CYP39A1 expression was associated with tumor stage, depth of invasion, lymph node metastasis, distant metastasis, and poor survival. The microvessel and lymphatic vessel density values of CYP39A1-positive tumors were significantly higher than those of CYP39A1-negative tumors. These results indicate that CYP39A1 is associated with tumor progression by influencing tumor cell angiogenesis and lymphangiogenesis in CRC.

Over-expression of Anterior Gradient 3 Is Associated With Tumor Progression and Poor Survival in Gastric Cancer.

BACKGROUND/AIM: Anterior gradient (AGR) proteins, including AGR1, AGR2, and AGR3, which are members of the protein disulfide isomerase family, have been reported as biomarkers for various carcinogenesis processes. Although AGR2 and AGR1 have been demonstrated to be associated with gastric cancer (GC) progression and poor survival, the effect of AGR3 on the progression and prognosis of GC remains unknown. Therefore, our study aimed to examine the expression and prognostic significance of AGR3 in patients with GC. PATIENTS AND METHODS: We investigated 271 GC patients receiving curative surgery. Formalin-fixed and paraffin-embedded tissue blocks were obtained, and long-term survival analysis was performed. The expression of AGR3 in GC tissues was investigated by quantitative reverse transcription-polymerase chain reaction, western blotting, and immunohistochemistry. RESULTS: AGR3 was over-expressed in GC tissue compared with paired normal tissue at the mRNA and protein levels. AGR3 over-expression was significantly associated with larger tumor size, deeper tumor invasion, lymph node metastasis, and advanced tumor stage. The overall survival of patients with positive AGR3 expression was significantly lower than that of patients without positive AGR3 expression. Multivariate analysis demonstrated that AGR3 and age were independent prognostic factors associated with overall survival. CONCLUSION: Over-expression of AGR3 was significantly associated with tumor progression and poor survival of GC patients. Therefore, AGR3 may be a novel biomarker and prognostic factor for GC.

A disintegrin and metalloprotease 12 contributes to colorectal cancer metastasis by regulating epithelial­mesenchymal transition.

A disintegrin and metalloprotease 12 (ADAM12) and epithelial­mesenchymal transition (EMT) are linked in the metastasis of various types of cancer. The present study aimed to assess the ability of ADAM12 to induce EMT and its potential as a therapeutic target for colorectal cancer (CRC). ADAM12 expression in CRC cell lines, CRC tissues and a mouse model of peritoneal metastasis was assessed. The effect of ADAM12 on CRC EMT and metastasis was investigated using ADAM12­pcDNA6­myc and ADAM12­pGFP­C­shLenti constructs. ADAM12 overexpression enhanced the proliferation, migration, invasion and EMT of CRC cells. The phosphorylation levels of factors associated with the PI3K/Akt pathway were also increased by ADAM12 overexpression. The knockdown of ADAM12 reversed these effects. ADAM12 expression and the loss of E­cadherin expression were significantly associated with poorer survival compared with other expression statuses of both proteins. In a mouse model of peritoneal metastasis, overexpression of ADAM12 induced increased tumor weight and peritoneal carcinomatosis index compared with that in the negative control group. Conversely, knockdown of ADAM12 reversed these effects. Furthermore, E­cadherin expression was significantly decreased by overexpression of ADAM12 compared with in the negative control group. By contrast, E­cadherin expression was increased by knockdown of ADAM12 compared with in the negative control group. ADAM12 overexpression contributed to CRC metastasis by regulating EMT. In addition, in the mouse model of peritoneal metastasis, ADAM12 knockdown exhibited strong anti­metastatic action. Consequently, ADAM12 may be considered a therapeutic target for CRC metastasis.

Expression of Apurinic/Apyrimidinic Endonuclease 1 in Colorectal Cancer and its Relation to Tumor Progression and Prognosis.

BACKGROUND/AIM: Over-expression of apurinic/apyrimidinic endonuclease 1 (APE1) has been demonstrated to be associated with cancer progression, chemo- and radioresistance in various cancers. This study examined the expression of APE1 and its relation to tumor progression and prognosis in patients with colorectal cancer (CRC). MATERIALS AND METHODS: We investigated 193 patients with CRC who received curative surgery for whom formalin-fixed and paraffin-embedded blocks were available, and long-term tumor-specific survival rate analysis was possible. The expression of APE1 was investigated by reverse transcription-polymerase chain reaction, western blotting, and immunohistochemistry in CRC and lymph node tissues. The apoptosis, proliferation, and angiogenesis of CRC cells were determined using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay, and immunohistochemical staining for Ki-67 and CD34 antibodies. RESULTS: APE1 was over-expressed in CRC and metastatic lymph node tissues compared with normal colorectal mucosa and non-metastatic lymph node tissues. Over-expression of APE1 was significantly associated with advanced stage, lymphovascular invasion, perineural invasion, deeper tumor invasion, lymph node metastasis, distant metastasis, and poor survival. Multivariate analysis demonstrated that APE1, perineural invasion, and lymph node metastasis were the independent prognostic factors associated with overall survival. The mean Ki-67 labeling index value of APE1-positive tumors was significantly higher than that of APE1-negative tumors. However, there was no significant association between APE1 expression and the apoptotic index or microvessel density. CONCLUSION: Over-expression of APE1 is significantly associated with tumor progression and poor survival in patients with CRC. Therefore, APE1 may be a novel biomarker and present a potential prognostic factor for CRC.

Cytochrome P450 Family 46 Subfamily A Member 1 Promotes the Progression of Colorectal Cancer by Inducing Tumor Cell Proliferation and Angiogenesis.

BACKGROUND/AIM: Cytochrome P450 family 46 subfamily A member 1 (CYP46A1) has been implicated in the development and progression of various cancers. This study aimed to analyze the expression of CYP46A1, examining its relationship with oncogenic behaviors, and determining its prognostic implications in colorectal cancer (CRC). MATERIALS AND METHODS: A total of 225 patients with CRC who underwent curative surgical resection were examined using paraffin-embedded tissue blocks and subjected to tumor-specific survival analysis. The expression of CYP46A1 was assessed in CRC tissues through reverse transcription-polymerase chain reaction, western blotting, and immunohistochemistry. The CRC cells' apoptosis, proliferation, angiogenesis, and lymphangiogenesis were analyzed using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assays, alongside immunohistochemical staining for Ki-67, CD34, and D2-40 antibodies. RESULTS: CYP46A1 expression was found to be up-regulated in CRC tissues compared to normal colorectal mucosa. Such expression was significantly associated with advanced stage, deeper tumor invasion, lymph node metastasis, distant metastasis, and decreased survival. Furthermore, the mean Ki-67 labeling index and microvessel density values in CYP46A1-positive tumors were significantly elevated compared to CYP46A1-negative tumors. However, there was no discernible correlation between CYP46A1 expression and either the apoptotic index or lymphatic vessel density value. CONCLUSION: CYP46A1 promotes CRC progression, specifically through the induction of tumor cell proliferation and angiogenesis. The insights provided may hold potential implications for future therapeutic interventions targeting CYP46A1.

Knockdown of RON inhibits AP-1 activity and induces apoptosis and cell cycle arrest through the modulation of Akt/FoxO signaling in human colorectal cancer cells.

BACKGROUND/AIMS: Altered Recepteur d'Origine nantais (RON) expression transduces signals inducting invasive growth phenotype that includes cell proliferation, migration, matrix invasion, and protection of apoptosis in human cancer cells. The aims of the current study were to evaluate whether RON affects tumor cell behavior and cellular signaling pathways including activator protein-1 (AP-1) and Akt/forkhead box O (FoxO) in human colorectal cancer cells. METHODS: To study the biological role of RON on tumor cell behavior and cellular signaling pathways in human colorectal cancer, we used small interfering RNA (siRNA) to knockdown RON gene expression in human colorectal cancer cell line, DKO-1. RESULTS: Knockdown of RON diminished migration, invasion, and proliferation of human colorectal cancer cells. Knockdown of RON decreased AP-1 transcriptional activity and expression of AP-1 target genes. Knockdown of RON activated cleaved caspase-3, -7, -9, and PARP, and down-regulated the expression of Mcl-1, survivin and XIAP, leading to induction of apoptosis. Knockdown of RON induced cell cycle arrest in the G2/M phase of cancer cells by an increase of p27 and a decrease of cyclin D3. Knockdown of RON inhibited the phosphorylation of Akt/FoxO signaling proteins such as Ser473 and Thr308 of Akt and FoxO1/3a. CONCLUSIONS: These results indicate that knockdown of RON inhibits AP-1 activity and induces apoptosis and cell cycle arrest through the modulation of Akt/FoxO signaling in human colorectal cancer cells.

RON is associated with tumor progression via the inhibition of apoptosis and cell cycle arrest in human gastric cancer.

The recepteur d'origine nantais (RON) receptor tyrosine kinase is overexpressed in epithelial cancers, including gastric cancer. The aims of the present study were to evaluate whether RON affects tumor cell behaviors and oncogenic signaling pathways, and to document the relationship of its expression with various clinicopathological parameters in gastric cancer. The biological role of RON in tumor cell behaviors and oncogenic signaling pathways was investigated by using small interfering RNA in gastric cancer cell lines including AGS and MKN28. The expression of RON in gastric cancer tissues was investigated by using reverse transcription polymerase chain reaction and immunohistochemistry. Knockdown of RON suppressed tumor cell migration and invasion in AGS and MKN28, induced apoptosis through modulation of anti-apoptotic and pre-apoptotic genes and induced cell cycle arrest by decreasing cyclin D1, cyclin D3 and CDK4, and by inducing p21 and p27 expression. Signaling cascades, including Akt and mitogen-activated protein kinase (MAPK), were significantly blocked by knockdown of RON. Expression of RON was significantly associated with tumor size, depth of invasion, lymph node metastasis, tumor stage and poor survival. These results indicate that RON is associated with tumor progression via the inhibition of apoptosis and cell cycle arrest in human gastric cancer.

Expression of ADAM12 in Gastric Cancer and its Relation to Tumor Cell Behavior and Prognosis.

BACKGROUND/AIM: A disintegrin and metalloprotease (ADAM) 12 expression has been found up-regulated in various cancer types. The aim of the study was to evaluate whether ADAM12 affects oncogenic behavior of gastric cancer (GC) cells and investigate its prognostic value. MATERIALS AND METHODS: The effect of ADAM12 on tumor cell behavior was examined using the small interfering RNA and pcDNA6-myc vector in human GC cell lines. Expression of ADAM12 in GC tissues was confirmed by immunohistochemistry. Apoptosis and proliferation were determined by a terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay and immunohistochemical staining for Ki-67. RESULTS: ADAM12 overexpression enhanced tumor cell migration and invasion in AGS and SNU638 cells. Down-regulation of caspase-3 and PARP activity due to ADAM12 overexpression enhanced tumor cell proliferation and inhibited apoptosis. The expression of Snail and Vimentin increased and that of E-cadherin decreased following ADAM12 overexpression. In contrast, ADAM12 knockdown reversed these effects. ADAM12 overexpression increased the phosphorylation of Akt and GSK-3ß. The mean Ki-67 labeling index value of ADAM12-positive tumors was significantly higher compared to that of ADAM12-negative tumors. ADAM12 expression was associated with age, tumor size, cancer stage, depth of invasion, lymph node metastasis, and poor survival. CONCLUSION: ADAM12 enhances tumor progression by increasing cell mobility, enhancing cell proliferation, and inhibiting apoptosis in GC cells. Also, ADAM12 is associated with adverse clinicopathological features and poor survival. It may be used as a molecular marker for the prediction of clinical outcomes of patients with GC.

Engulfment and Cell Motility 1 (ELMO1) Regulates Tumor Cell Behavior and Predicts Prognosis in Colorectal Cancer.

BACKGROUND/AIM: Engulfment and cell motility 1 (ELMO1) plays a crucial role in the process of migration, chemotaxis, and metastasis of tumor cells. ELMO1 has been implicated in the pathogenesis of various cancers. However, the distinct function of ELMO1 in colorectal cancer (CRC) is unclear. We determined whether ELMO1 affects the oncogenic behavior of CRC cells and investigated its prognostic value in CRC patients. MATERIALS AND METHODS: We investigated the impact of ELMO1 on tumor cell behavior using small interference RNA (siRNA) in CRC cell lines, including SW480 and DLD1. The expression of ELMO1 was investigated by reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry, and enzyme-linked immunosorbent assay (ELISA) in cancer tissues and sera obtained from CRC patients. RESULTS: ELMO1 knockdown suppressed tumor cell proliferation in SW480 and DLD1 cells. ELMO1 knockdown-induced apoptosis through up-regulation of caspase-3, -7, and PARP activities and down-regulation of the anti-apoptotic Mcl-1 protein. ELMO1 knockdown-induced cell-cycle arrest by decreasing cyclin D1, cyclin-dependent kinase 2, 4 and 6, and the 25C cell division cycle (CDC25C). ELMO1 knockdown suppressed tumor cell invasion and migration. The expression of E-cadherin was increased, while that of Vimentin and Claudin 1 decreased following ELMO1 knockdown. The phosphorylation levels of PDK1, Akt, and GSK-3ß and were down-regulated after ELMO1 knockdown. The expression of ELMO1 was found up-regulated in cancer tissues and sera taken from CRC patients. ELMO1 expression was significantly associated with tumor stage, lymph node metastasis, distant metastases, and poor survival. CONCLUSION: ELMO1 mediates tumor progression by increasing tumor cell motility and inhibiting apoptosis in human CRC.

CD47 mediates the progression of colorectal cancer by inducing tumor cell apoptosis and angiogenesis.

CD47 is an immunoregulatory protein that is found on the cell surface and plays significant roles in cellular functions such as proliferation, apoptosis, migration, and immune homeostasis. CD47 is overexpressed in various human cancers and is associated with tumor development, progression, and poor prognosis. In this study, we analyzed the expression of CD47 to determine whether it affected the oncogenic behavior of colorectal cancer (CRC) and investigated the prognostic value of CD47 expression in patients with CRC. We investigated 468 patients with CRC who underwent curative surgery and examined the expression of CD47 in tumor and lymph node tissues by performing RT-PCR and immunohistochemistry. Apoptosis, proliferation, angiogenesis, and lymphangiogenesis were determined via a TUNEL assay and immunohistochemical staining for Ki-67, CD34, and D2-40. CD47 expression was increased in human CRC tumors and metastatic lymph nodes compared with normal colorectal mucosa and non-metastatic lymph node tissues. CD47 expression was significantly associated with perineural invasion, lymphovascular invasion, cell differentiation, cancer stage, depth of invasion, lymph node metastasis, distant metastasis, and poor survival. The mean apoptotic index and microvessel density value of CD47-positive tumors were significantly higher than those of CD47-negative tumors. However, no significant difference was observed between CD47 expression and Ki-67 labeling index or lymphatic vessel density. These results indicate that CD47 mediated the progression of CRC by inducing tumor cell apoptosis and angiogenesis.

Black tea polyphenol theaflavin suppresses LPS-induced ICAM-1 and VCAM-1 expression via blockage of NF-κB and JNK activation in intestinal epithelial cells.

OBJECTIVE: The aim of this study was to determine the impact of the black tea polyphenol, theaflavin, on the expression of adhesion molecules and activation of lipopolysaccharide (LPS)-induced innate signaling in rat intestinal epithelial (RIE) cells. METHODS: The effect of theaflavin on neutrophil adhesion, expression of intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1, LPS-induced nuclear factor-kappa B (NF-κB), and mitogen-activated protein kinase (MAPK) signaling was examined by neutrophil adhesion assay, RT-PCR, Western blotting, immunofluorescence, and electrophoretic mobility shift assay (EMSA). RESULTS: Theaflavin suppressed adhesion of neutrophils to LPS-stimulated RIE cells. LPS-induced ICAM-1 and VCAM-1 expressions were inhibited by theaflavin. LPS-induced IκBα phosphorylation/degradation and nuclear translocation of NF-κB/p65 were blocked by theaflavin. Also, theaflavin blocked NF-κB DNA-binding activity in EMSA. LPS-induced phosphorylation of JNK was inhibited by theaflavin. Bay11-7082 (a NF-κB inhibitor) and SP600125 (a JNK inhibitor) suppressed the LPS-induced ICAM-1 and VCAM-1 mRNA accumulations. CONCLUSIONS: These results indicate that black tea polyphenol theaflavin suppresses LPS-induced ICAM-1 and VCAM-1 expressions through blockage of NF-κB and JNK activation in intestinal epithelial cells.

KITENIN is associated with activation of AP-1 target genes via MAPK cascades signaling in human hepatocellular carcinoma progression.

KITENIN promotes cancer cell migration and invasion in vitro and cancer metastasis in mouse cancer models, including colon and head and neck cancers. The purposes of this study were to observe the effect of KITENIN on tumor cell behaviors of human hepatocellular carcinoma (HCC) cells and to evaluate its expression in human HCC tissues. To functionally characterize KITENIN in human HCC, we depleted its expression in human HCC cell lines, HepG2 and Huh7, by using small interfering RNA (siRNA). Invasion and proliferation assays were performed. The activator protein-1 (AP-1) transcriptional activity and expression of AP-1 target genes were evaluated by AP-1 luciferase reporter assay and RT-PCR. The contribution of mitogen-activated protein kinase (MAPK) cascade signaling involved in AP-1 activation was assessed by Western blotting. We evaluated the expression of KITENIN and AP-1 target genes at mRNA levels by RT-PCR in human HCC tissues and paired normal hepatic mucosa of the same patients taken by surgery. Knockdown of KITENIN in HepG2 and Huh7 cells resulted in a significant reduction of tumor cell invasion. The tumor cell proliferation was significantly decreased in the KITENIN knocked down Huh7 cells compared to the negative control. The mRNA expressions of MMP-3 and COX-2 were decreased in KITENIN knocked down Huh7 cells. The mRNA expression of MMP-1 was decreased in KITENIN knocked down HepG2 cells. The AP-1 transcriptional activity in Huh7 cells was significantly decreased by knockdown of KITENIN. The JNK and ERK1/2 phosphorylations were decreased in KITENIN knocked down HepG2 and the p38 phosphorylation was decreased in KITENIN knocked down Huh7 cells. The mRNA expressions of KITENIN, MMP-1, and MMP-3 were significantly upregulated in human HCC tissues compared to paired normal mucosa. These results indicate that KITENIN is associated with activation of AP-1 target genes via MAPK cascades signaling in human HCC progression.

Expression of KITENIN in human colorectal cancer and its relation to tumor behavior and progression.

KAI1 COOH-terminal interacting tetraspanin (KITENIN) contributes to tumor invasion and metastasis in various cancers. The aim of current study was to evaluate whether KITENIN affects tumor cell invasion and prognosis in human colorectal cancers. We investigated the biologic role of KITENIN on tumor cell invasion by using small interfering RNA in Caco2, DLD1, and SW480. We evaluated the expression of KITENIN and activator protein-1 (AP-1) target genes in human colorectal cancer tissues. The tumor cell invasion was decreased by knockdown of KITENIN in three tested cell lines. The mRNA expression of cyclin D1 and COX-2 was decreased in KITENIN knockdown Caco2 and the mRNA expression of MMP-3 and COX-2 was decreased in KITENIN knockdown DLD1 and SW480. The extracellular-signal protein kinase 1/2 (ERK1/2) phosphorylation was decreased in KITENIN knockdown in three tested cell lines. Expression of KITENIN and AP-1 target genes was significantly increased in human colorectal cancer tissues. The ERK1/2, c-Jun N-terminal kinase (JNK) and p38 phosphorylations were increased in human colorectal cancer tissues. Expression of KITENIN was significantly associated with lymphovascular invasion, depth of invasion, lymph node metastasis, tumor stage and poor survival. These results indicate that KITENIN is associated with human colorectal cancer progression including invasion and metastasis.

Black tea extract prevents lipopolysaccharide-induced NF-κB signaling and attenuates dextran sulfate sodium-induced experimental colitis.

BACKGROUND: Black tea has been shown to elicit anti-oxidant, anti-carcinogenic, anti-inflammatory and anti-mutagenic properties. In this study, we investigated the impact of black tea extract (BTE) on lipopolysaccharide (LPS)-induced NF-κB signaling in bone marrow derived-macrophages (BMM) and determined the therapeutic efficacy of this extract on colon inflammation. METHODS: The effect of BTE on LPS-induced NF-κB signaling and pro-inflammatory gene expression was evaluated by RT-PCR, Western blotting, immunofluorescence and electrophoretic mobility shift assay (EMSA). The in vivo efficacy of BTE was assessed in mice with 3% dextran sulfate sodium (DSS)-induced colitis. The severity of colitis was measured by weight loss, colon length and histologic scores. RESULTS: LPS-induced IL-12p40, IL-23p19, IL-6 and IL-1ß mRNA expressions were inhibited by BTE. LPS-induced IκBα phosphorylation/degradation and nuclear translocation of NF-κB/p65 were blocked by BTE. BTE treatment blocked LPS-induced DNA-binding activity of NF-κB. BTE-fed, DSS-exposed mice showed the less weight loss, longer colon length and lower histologic score compared to control diet-fed, DSS-exposed mice. DSS-induced IκBα phosphorylation/degradation and phosphorylation of NF-κB/p65 were blocked by BTE. An increase of cleaved caspase-3 and poly (ADP-ribose) polymerase (PARP) in DSS-exposed mice was blocked by BTE. CONCLUSIONS: These results indicate that BTE attenuates colon inflammation through the blockage of NF-κB signaling and apoptosis in DSS-induced experimental colitis model.

A Disintegrin and Metalloprotease 12 Promotes Tumor Progression by Inhibiting Apoptosis in Human Colorectal Cancer.

A disintegrin and metalloprotease 12 (ADAM12) has been implicated in cell growth, tumor formation, and metastasis. Therefore, we evaluated the role of ADAM12 in colorectal cancer (CRC) progression and prognosis, and elucidated whether targeted downregulation of ADAM12 could lead to therapeutic sensitization. The effect of ADAM12 on tumor cell behavior was assessed in CRC cell lines, CRC tissues, and a mouse xenograft model. ADAM12 overexpression enhanced proliferation, inhibited apoptosis, and acted as positive regulator of cell cycle progression in CRC cells. Phosphorylation of PTEN was decreased and that of Akt was increased by ADAM12 overexpression. These results were reversed upon ADAM12 knockdown. ADAM12 overexpression was significantly associated with the cancer stage, depth of invasion, lymph node metastasis, distant metastasis, and poor survival in CRC patients. In a mouse xenograft model, tumor area, volume, and weight were significantly greater for the ADAM12-pcDNA6-myc-transfected group than for the empty-pcDNA6-myc-transfected group, and significantly lower for the ADAM12-pGFP-C-shLenti-transfected group than for the scrambled pGFP-C-shLenti-transfected group. In conclusion, ADAM12 overexpression is essential for the growth and progression of CRC. Furthermore, ADAM12 knockdown reveals potent anti-tumor activity in a mouse xenograft model. Thus, ADAM12 may serve as a promising biomarker and/or therapeutic target in CRC.

Engulfment and cell motility 1 promotes tumor progression via the modulation of tumor cell survival in gastric cancer.

BACKGROUND/AIM: Engulfment and cell motility 1 (ELMO1) protein has been implicated in phagocytosis of apoptotic cells, cell migration, neurite outgrowth, cancer cell invasion and metastasis, and poor prognosis in various cancers. We investigated the role of ELMO1 in mediating the oncogenic behavior of gastric cancer (GC) cells. We also investigated the correlation between expression of ELMO1 in GC tissues and various clinicopathological parameters. METHODS: We studied the impact of ELMO1 on tumor cell behavior using the pcDNA-myc vector and small interfering RNA in AGS and SNU1750 GC cell lines. We performed western blotting and immunohistochemistry to investigate the expression of ELMO1 in GC cells and tissues. RESULTS: ELMO1 overexpression inhibited apoptosis via the modulation of PARP, caspase-3 and caspase-7 in GC cells. ELMO1 overexpression led to significant increase in the number of migrating and invading GC cells. The expression of E-cadherin decreased and that of Snail increased in GC cells upon ELMO1 overexpression. Phosphorylation of PI3K/Akt and GSK-3ß was increased and that of ß-catenin was decreased upon ELMO1 overexpression in GC cells. These results were reversed after ELMO1 knockdown. ELMO1 expression was significantly associated with tumor size, cancer stage, lymph node metastasis and survival. ELMO1-positive tumors had significantly higher mean of Ki-67 labeling index than ELMO1-negative tumors. There was no significant relationship between ELMO1 expression and the mean value of the apoptotic index. CONCLUSIONS: Our results indicate that ELMO1 promotes tumor progression by modulating tumor cell survival in human GC.