Activated Leukocyte Cell Adhesion Molecule (ALCAM), a Potential 'Seed' and 'Soil' Receptor in the Peritoneal Metastasis of Gastrointestinal Cancers.

Activated Leukocyte Cell Adhesion Molecule (ALCAM/CD166) is a cell-cell adhesion protein conferring heterotypic and homotypic interactions between cells of the same type and different types. It is aberrantly expressed in various cancer types and has been shown to be a regulator of cancer metastasis. In the present study, we investigated potential roles of ALCAM in the peritoneal transcoelomic metastasis in gastrointestinal cancers, a metastatic type commonly occurred in gastro-intestinal and gynaecological malignancies and resulting in poor clinical outcomes. Specifically, we studied whether ALCAM acts as both a 'seed' receptor in these tumour cells and a 'soil' receptor in peritoneal mesothelial cells during cancer metastasis. Gastric cancer and pancreatic cancer tissues with or without peritoneal metastasis were compared for their levels of ALCAM expression. The impact of ALCAM expression in these tumours was also correlated to the patients' clinical outcomes, namely peritoneal metastasis-free survival. In addition, cancer cells of gastric and pancreatic origins were used to create cell models with decreased or increased levels of ALCAM expression by genetic knocking down or overexpression, respectively. Human peritoneal mesothelial cells were also genetically transfected to generate cell models with different profiles of ALCAM expression. These cell models were used in the tumour-mesothelial interaction assay to assess if and how the interaction was influenced by ALCAM. Both gastric and pancreatic tumour tissues from patients who developed peritoneal metastases had higher levels of ALCAM transcript than those without. Patients who had tumours with high levels of ALCAM had a much shorter peritoneal metastasis free survival compared with those who had low ALCAM expression (p = 0.006). ALCAM knockdown of the mesothelial cell line MET5A rendered the cells with reduced interaction with both gastric cancer cells and pancreatic cancer cells. Likewise, levels of ALCAM in both human gastric and pancreatic cancer cells were also a determining factor for their adhesiveness to mesothelial cells, a process that was likely to be triggered the phosphorylation of the SRC kinase. A soluble ALCAM (sALCAM) was found to be able to inhibit the adhesiveness between cancer cells and mesothelial cells, mechanistically behaving like a SRC kinase inhibitor. ALCAM is an indicator of peritoneal metastasis in both gastric and pancreatic cancer patients. It acts as not only a potential peritoneal 'soil' receptor of tumour seeding but also a 'soil' receptor in peritoneal mesothelial cells during cancer metastasis. These findings have an important therapeutic implication for treating peritoneal transcoelomic metastases.

Striatins and STRIPAK complex partners in clinical outcomes of patients with breast cancer and responses to drug treatment.

Objective: Striatins (STRNs) family, which contains three multi-domain scaffolding proteins, are cornerstones of the striatins interacting phosphatase and kinase (STRIPAK) complex. Although the role of the STRIPAK complex in cancer has become recognized in recent years, its clinical significance in breast cancer has not been fully established. Methods: Using a freshly frozen breast cancer tissue cohort containing both cancerous and adjacent normal mammary tissues, we quantitatively evaluated the transcript-level expression of all members within the STRIPAK complex along with some key interacting and regulatory proteins of STRNs. The expression profile of each molecule and the integrated pattern of the complex members were assessed against the clinical-pathological factors of the patients. The Cancer Genome Atlas (TCGA) dataset was used to evaluate the breast cancer patients' response to chemotherapies. Four human breast cancer cell lines, MDA-MB-231, MDA-MB-361, MCF-7, and SK-BR-3, were subsequently adopted for in vitro work. Results: Here we found that high-level expressions of STRIP2, calmodulin, CCM3, MINK1 and SLMAP were respectively associated with shorter overall survival (OS) of patients. Although the similar pattern observed for STRN3, STRN4 and a contrary pattern observed for PPP2CA, PPP2CB and PPPR1A were not significant, the integrated expression profile of STRNs group and PPP2 group members constitutes a highly significant prognostic indicator for OS [P<0.001, hazard ratio (HR)=2.04, 95% confidence interval (95% CI), 1.36-3.07] and disease-free survival (DFS) (P=0.003, HR=1.40, 95% CI, 1.12-1.75). Reduced expression of STRN3 has an influence on the biological functions including adhesiveness and migration. In line with our clinical findings, the breast cancer cells responded to STRN3 knockdown with changes in their chemo-sensitivity, of which the response is also breast cancer subtype dependent. Conclusions: Our results suggest a possible role of the STRIPAK complex in breast cancer development and prognosis. Among the members, the expression profile of STRN3 presents a valuable factor for assessing patients' responses to drug treatment.

EPLIN, a Putative Tumour Suppressor in Colorectal Cancer, Implications in Drug Resistance.

Colorectal cancer is a serious threat to human health. Poor prognosis and frequently reported drug resistance urges research into novel biomarkers and mechanisms to aid in the understanding of the development and progression of colorectal cancer and to optimise therapeutic strategies. In the current study, we investigated the roles of a putative tumour suppressor, EPLIN, in colorectal cancer. Our clinical colorectal cancer cohort and online databases revealed a downregulation of EPLIN in colorectal cancer tissues compared with normal tissues. The reduced expression of EPLIN was associated with poor clinical outcomes of patients. In vitro cellular function assays showed that EPLIN elicited an inhibitory effect on cellular growth, adhesion, migration and invasion. Utilising a protein microarray on protein samples from normal and tumour patient tissues suggested HSP60, Her2 and other signalling events were novel potential interacting partners of EPLIN. It was further revealed that EPLIN and HSP60 were negative regulators of Her2 in colorectal cancer cells. The clinical cohort also demonstrated that expression of HSP60 and Her2 affected clinical outcomes, but most interestingly the combination of EPLIN, HSP60 and Her2 was able to identify patients with the most unfavourable clinical outcome by independently predicting patient overall survival and disease free survival. Furthermore, EPLIN and HSP60 exhibited potential to regulate cellular response to chemotherapeutic and EGFR/Her2 targeted therapeutic agents. In conclusion, EPLIN is an important prognostic factor for patients with colon cancer and reduced EPLIN in CRC contributes to aggressive traits of CRC cells and their responses to chemotherapeutic drugs. Collectively, EPLIN is a pivotal factor for the development and progression of colorectal cancer and has important clinical and therapeutic values in this cancer type.

Dual effects of targeting S100A11 on suppressing cellular metastatic properties and sensitizing drug response in gastric cancer.

BACKGROUND: S100A11 is a member of the S100 family of proteins containing two EF-hand calcium-binding motifs. The dysregulated expression of the S100A11 gene has been implicated in tumour metastasis. However, the role of S100A11 protein in tumour cell response to chemotherapeutic drugs has not been characterised. METHODS: Transcript levels of S100A11 in gastric cancer were evaluated using an in-house patient cohort. Protein expression of S100A11 in gastric cancer was estimated by immunohistochemistry of a tissue microarray. The stable gastric cancer cell lines were established using lentiviral shRNA vectors. The knockdown of S100A11 was validated by qRT-PCR, PCR, and Western blot. The cellular function of S100A11 was estimated by assays of cell adhesion, migration, and invasion. The cell cytotoxic assay was performed to investigate the response to chemotherapeutic drugs. An unsupervised hierarchical clustering and principal component analysis (HCPC) was applied to unveil the dimensional role of S100A11 among all S100 family members in gastric cancer. RESULTS: High expression of S100A11 is associated with poor survival of gastric cancer patients (p < 0.001, HR = 1.85) and is an independent prognostic factor of gastric cancer. We demonstrate that S100A11 plays its role as a tumour promoter through regulating the MMP activity and the epithelial-mesenchymal transition (EMT) process. The stable knockdown of S100A11 suppresses the metastatic properties of gastric cancer cells, which include enhancing cell adhesion, but decelerating cell migration and invasion. Furthermore, the knockdown of S100A11 gene expression dramatically induces the cellular response of gastric cancer cells to the first-line chemotherapeutic drugs fluoropyrimidine 5-fluorouracil (5-FU) and cisplatin. CONCLUSION: The present study identifies S100A11 as a tumour promoter in gastric cancer. More importantly, the S100A11-specific targeting potentially presents dual therapeutic benefits by not only controlling tumour progression but also sensitising chemotherapeutic cytotoxic response.

Alteration in the sensitivity to crizotinib by Na+/H+ exchanger regulatory factor 1 is dependent to its subcellular localization in ALK-positive lung cancers.

BACKGROUND: Na+/H+ exchanger regulatory factor 1 (NHERF1) is an important scaffold protein participates in the modulation of a variety of intracellular signal pathways. NHERF1 was able to enhance the effects of chemo-drugs in breast and cervical cancer cells. Anaplastic lymphoma kinase (ALK) fusion mutations are validated molecules targeted therapy in lung cancers, where crizotinib can be used as the specific inhibitor to suppress tumor progression. However, due to the less frequent occurrence of ALK mutations and the complexity for factors to determine drug responses, the genes that could alter crizotinib sensitivity are unclear. METHODS: Both ALK-translocated and ALK-negative lung adenocarcinoma specimens in tissue sections were collected for immunohistochemistry. The possible mechanisms of NHERF1 and its role in the cell sensitivity to crizotinib were investigated using an ALK-positive and crizotinib-sensitive lung adenocarcinoma cell line H3122. Either a NHERF1 overexpression vector or agents for NHERF1 knockdown was used for crizotinib sensitivity measures, in association with cell viability and apoptosis assays. RESULTS: The expression level of NHERF1 in ALK-translocated NSCLC was significantly higher than that in other lung cancer tissues. NHERF1 expression in ALK positive lung cancer cells was regulated by ALK activities, and was in return able to alter the sensitivity to crizotinib. The function of NHERF1 to influence crizotinib sensitivity was depending on its subcellular distribution in cytosol instead of its nucleus localized form. CONCLUSION: Ectopically overexpressed NHERF1 could be a functional protein for consideration to suppress lung cancers. The determination of NHERF1 levels in ALK positive NSCLC tissues might be useful to predict crizotinib resistance, especially by distinguishing cytosolic or nuclear localized NHERF1 for the overexpressed molecules.

Enhanced osteopontin splicing regulated by RUNX2 is HDAC-dependent and induces invasive phenotypes in NSCLC cells.

BACKGROUND: Increased cell mobility is a signature when tumor cells undergo epithelial-to-mesenchymal transition. TGF-ß is a key stimulating factor to promote the transcription of a variety of downstream genes to accelerate cancer progression and metastasis, including osteopontin (OPN) which exists in several functional forms as different splicing variants. In non-small cell lung cancer cells, although increased total OPN expression was observed under various EMT conditions, the exact constitution and the underlining mechanism towards the generation of such OPN splicing isoforms was poorly understood. METHODS: We investigated the possible mechanisms of osteopontin splicing variant and its role in EMT and cancer metastasis using NSCLC cell line and cell and molecular biology techniques. RESULTS: In this study, we determined that OPNc, an exon 4 excluded shorter form of Opn gene products, appeared to be more potent to promote cell invasion. The expression of OPNc was selectively increased to higher abundance during EMT following TGF-ß induction. The switching from OPNa to OPNc could be enhanced by RUNX2 (a transcription factor that recognizes the Opn gene promoter) overexpression, but appeared to be strictly in a HDAC dependent manner in A549 cells. The results suggested the increase of minor splicing variant of OPNc required both (1) the enhanced transcription from its coding gene driven by specific transcription factors; and (2) the simultaneous modulation or fluctuation of the coupled splicing process that depends to selective classed of epigenetic regulators, predominately HDAC family members. CONCLUSION: Our study not only emphasized the importance of splicing variant for its role in EMT and cancer metastasis, but also helped to understand the possible mechanisms of the epigenetic controls for defining the levels and kinetic of gene splicing isoforms and their generations.

Effect of younger age on survival outcomes in T1N0M0 breast cancer: A propensity score matching analysis.

PURPOSE: We evaluated the effect of younger age on recurrence risk in Chinese women diagnosed with T1N0M0 breast cancer (BC), using propensity score matching (PSM) analysis. METHODS: We included 365 women who were diagnosed with T1N0M0 BC between 2003 and 2016, and who received surgery at our center. They were classified as younger (≤40 years) and older (>40 years). We used PSM to balance clinicopathologic characteristics between the two age groups. Survival was analyzed by the Kaplan-Meier method, before and after PSM. RESULTS: Over a median follow-up period of 79 months, 54 patients developed recurrences. Before PSM, younger patients had worse recurrence-free survival (RFS) than older patients. Significantly worse RFS was seen in younger patients with HER2+ BC compared with their older counterparts. Younger patients had higher rates of locoregional recurrence rather than metastasis, especially in the first 5 years after diagnosis. After PSM, the two age groups still significantly differed in 5-year RFS. CONCLUSION: Among PSM pairs with T1N0M0 BC, with equal baselines and treatment conditions, we found that patients who presented at younger ages had worse outcomes, independently of other pathological features. Younger patients with BC may require more individualized therapy to improve their prognosis.

Mechanistic insights of epithelial protein lost in neoplasm in prostate cancer metastasis.

EPLIN is frequently downregulated or lost in various cancers. The purpose of this study was to evaluate the importance of EPLIN in prostate cancer progression, with particular focus on the mechanistic implications to elucidate EPLIN's tumor suppressive function in cancer. EPLIN expression was evaluated in prostate cancer cell lines and tissues. PC-3 and LNCaP EPLINα overexpression models were generated through transfection with EPLINα sequence and EPLIN knockdown was achieved using shRNA in CA-HPV-10 cells. Functional assays were performed to evaluate cellular characteristics and potential mechanisms were evaluated using a protein microarray, and validated using western blot analysis. EPLIN expression was reduced in clinical prostate cancer sections, including hyperplasia (p ≤ 0.001) and adenocarcinoma (p = 0.005), when compared to normal prostate tissue. EPLINα overexpression reduced cell growth, migration and invasion, and influenced transcript, protein and phosphoprotein expression of paxillin, FAK and Src. EPLIN knockdown increased the invasive and migratory nature of CA-HPV-10 cells and also induced changes to FAK and Src total and/or phospho expression. Functional characterization of cellular migration and invasion in addition to FAK and Src inhibition demonstrated differential effects between control and EPLINα overexpression and EPLIN knockdown cell lines. This study highlights that EPLIN expression in prostate cancer is able to influence several aspects of cancer cell characteristics, including cell growth, migration and invasion. The mechanism of the tumor suppressive action of EPLIN remains to be fully elucidated; and this study proposes a role for EPLIN's ability to regulate the aggressive characteristics of prostate cancer cells partially through regulating FAK/Src signaling.

Involvement of hedgehog pathway in early onset, aggressive molecular subtypes and metastatic potential of breast cancer.

BACKGROUND: Dysregulation of hedgehog pathway is observed in numerous cancers. Relevance of hedgehog pathway genes in cancer cohort and inhibition of its downstream effector (GLI1) towards metastasis in cell lines are explored in the study. METHOD: One hundred fifty fresh tumours of breast cancer patients were collected for the study. Based on differential expression, panel of 6 key regulators of the pathway (SHH, DHH, IHH, PTCH1, SMO and GLI1) in microarray datasets were identified. Expressional profiles of aforementioned genes were later correlated with clinico-pathological parameters in Pakistani breast cancer cohort at transcript and protein levels. In addition, GLI1 over expressing breast cancer cell lines (MDA-MB-231 and MCF-7) were treated with GANT61 to explore its probable effects on metastasis. RESULT: SHH, DHH, PTCH1 and GLI1 were significantly over-expressed in tumours as compared with respective normal mammary tissues. A significant correlation of SHH, DHH and GLI1 expression with advanced tumour size, stages, grades, nodal involvement and distant metastasis was observed (p < 0.05). Over-expression of SHH, DHH and GLI1 was significantly related with patients having early onset and pre-menopausal status. Of note, hedgehog pathway was frequently up regulated in luminal B and triple negative breast cancer affected women. In addition, positive correlations were observed among aforementioned members of pathway and Ki67 (r-value: 0.63-0.78) emphasizing their role towards disease progression. Exposure of GANT61 (inhibitor for GLI1) significantly restricted cell proliferation, reduced cell motility and invasion. CONCLUSION: Role of activated hedgehog pathway in breast cancer metastasis provides a novel target for cancer therapy against aggressive cancer subtypes.

MicroRNA-1 acts as a tumor suppressor microRNA by inhibiting angiogenesis-related growth factors in human gastric cancer.

BACKGROUND: We recently reported that miR-1 was one of the most significantly downregulated microRNAs in gastric cancer (GC) patients from The Cancer Genome Atlas microRNA sequencing data. Here we aim to elucidate the role of miR-1 in gastric carcinogenesis. METHODS: We measured miR-1 expression in human GC cell lines and 90 paired primary GC samples, and analyzed the association of its status with clinicopathological features. The effect of miR-1 on GC cells was evaluated by proliferation and migration assay. To identify the target genes of miR-1, bioinformatic analysis and protein array analysis were performed. Moreover, the regulation mechanism of miR-1 with regard to these predicted targets was investigated by quantitative PCR (qPCR), Western blot, ELISA, and endothelial cell tube formation. The putative binding site of miR-1 on target genes was assessed by a reporter assay. RESULTS: Expression of miR-1 was obviously decreased in GC cell lines and primary tissues. Patients with low miR-1 expression had significantly shorter overall survival compared with those with high miR-1 expression (P = 0.0027). Overexpression of miR-1 in GC cells inhibited proliferation, migration, and tube formation of endothelial cells by suppressing expression of vascular endothelial growth factor A (VEGF-A) and endothelin 1 (EDN1). Conversely, inhibition of miR-1 with use of antago-miR-1 caused an increase in expression of VEGF-A and EDN1 in nonmalignant GC cells or low-malignancy GC cells. CONCLUSIONS: MiR-1 acts as a tumor suppressor by inhibiting angiogenesis-related growth factors in human gastric cancer. Downregulated miR-1 not only promotes cellular proliferation and migration of GC cells, but may activates proangiogenesis signaling and stimulates the proliferation and migration of endothelial cells, indicating the possibility of new strategies for GC therapy.

PAK5 mediates cell: cell adhesion integrity via interaction with E-cadherin in bladder cancer cells.

Urothelial bladder cancer is a major cause of morbidity and mortality worldwide, causing an estimated 150 000 deaths per year. Whilst non-muscle-invasive bladder tumours can be effectively treated, with high survival rates, many tumours recur, and some will progress to muscle-invasive disease with a much poorer long-term prognosis. Thus, there is a pressing need to understand the molecular transitions occurring within the progression of bladder cancer to an invasive disease. Tumour invasion is often associated with a down-regulation of E-cadherin expression concomitant with a suppression of cell:cell junctions, and decreased levels of E-cadherin expression have been reported in higher grade urothelial bladder tumours. We find that expression of E-cadherin in a panel of bladder cancer cell lines correlated with the presence of cell:cell junctions and the level of PAK5 expression. Interestingly, exogenous PAK5 has recently been described to be associated with cell:cell junctions and we now find that endogenous PAK5 is localised to cell junctions and interacts with an E-cadherin complex. Moreover, depletion of PAK5 expression significantly reduced junctional integrity. These data suggest a role for PAK5 in maintaining junctional stability and we find that, in both our own patient samples and a commercially available dataset, PAK5mRNA levels are reduced in human bladder cancer compared with normal controls. Taken together, the present study proposes that PAK5 expression levels could be used as a novel prognostic marker for bladder cancer progression.

MicroRNA-7 suppresses the homing and migration potential of human endothelial cells to highly metastatic human breast cancer cells.

BACKGROUND: MicroRNA-7 (miR-7) has been observed as a potent tumour suppressor in multiple cancer types including breast cancer. The aim of this study was to investigate the response sensitivities of metastatic breast cancer cells to miR-7 and the roles of miR-7 in the interaction of endothelial cells and metastatic cancer cells. METHODS: Expression profile of miRNAs in a breast cancer specimen cohort and breast cancer cells were determined using real-time quantitative miRNA assays. Effect of the altering expression of miR-7 on migration, invasion, proliferation, interaction and underlying molecular mechanism of breast cancer cells and endothelial cells was investigated after treatment with the synthesised mimic of miR-7. Luciferase activity analysis was performed to validate Wave-3 as a novel target of miR-7. RESULTS: miR-7 expression was negatively correlated with the stage, grade and survival of the breast cancer patients. There was also differential expression of miRNAs including miR-7 in the breast cancer cells. The synthesised mimic of miR-7 inhibits the motility and wound healing potential of breast cancer cells. The highly metastatic MDA-MB-231 cells are more sensitive to the miR-7 treatment than the poorly invasive MCF-7 cells. Treatment with miR-7 downregulated the expression of EGFR, IGF1R and Wave3 in MDA-MB-231 cells but not in MCF-7 cells. In addition, we further demonstrated that miR-7 inhibited the proliferation, migration and invasion of endothelial cells. And more importantly, miR-7 suppressed the homing and migration of endothelial cells to more aggressive tumour cell conditions. CONCLUSIONS: Given the dual inhibitory effect of miR-7 on metastatic breast cancer cells alone and the interaction of endothelial cells with the tumour-conditioned microenvironment, we suggest miR-7 may be a new therapeutic candidate for its capacity not only to prevent breast cancer cell spreading but also to inhibit tumour-associated angiogenesis in the metastatic breast cancer.

Neural Wiskott-Aldrich syndrome protein (nWASP) is implicated in human lung cancer invasion.

Lung cancer is one of the most commonly diagnosed cancers with survival much lower in patients diagnosed with distal metastases. It is therefore imperative to identify pathways involved in lung cancer invasion and metastasis and to consider the therapeutic potential of agents that can interfere with these molecular pathways. This study examines nWASP expression in human lung cancer tissues and explores the effect of nWASP inhibition and knockdown on lung cancer cell behaviour. METHODS: QPCR has been used to measure nWASP transcript expression in human lung cancer tissues. The effect of wiskostatin, an nWASP inhibitor, on A-549 and SK-MES-1 lung carcinoma cell growth, adhesion, migration and invasion was also examined using several in vitro functional assays, including ECIS, and immunofluorescence staining. The effect of nWASP knockdown using siRNA on particular behaviours of lung cancer cells was also examined. RESULTS: Patients with high levels of nWASP expression in tumour tissues have significantly lower survival rates. nWASP transcript levels were found to correlate with lymph node involvement (p = 0.042). nWASP inhibition and knockdown was shown to significantly impair lung cancer cell growth. nWASP inhibition also affected other cell behaviours, in SK-MES-1 invasion and A-549 cell motility, adhesion and migration. Paxillin and FAK activity are reduced in lung cancer cell lines following wiskostatin and nWASP knockdown as shown by immunofluorescence and western blot. CONCLUSIONS: These findings highlight nWASP as an important potential therapeutic target in lung cancer invasion and demonstrate that inhibiting nWASP activity using the inhibitor wiskostatin can significantly alter cell behaviour in vitro.

Key Factors in Breast Cancer Dissemination and Establishment at the Bone: Past, Present and Future Perspectives.

Bone metastases associated with breast cancer remain a clinical challenge due to their associated morbidity, limited therapeutic intervention and lack of prognostic markers. With a continually evolving understanding of bone biology and its dynamic microenvironment, many potential new targets have been proposed. In this chapter, we discuss the roles of well-established bone markers and how their targeting, in addition to tumour-targeted therapies, might help in the prevention and treatment of bone metastases. There are a vast number of bone markers, of which one of the best-known families is the bone morphogenetic proteins (BMPs). This chapter focuses on their role in breast cancer-associated bone metastases, associated signalling pathways and the possibilities for potential therapeutic intervention. In addition, this chapter provides an update on the role receptor activator of nuclear factor-κB (RANK), RANK ligand (RANKL) and osteoprotegerin (OPG) play on breast cancer development and their subsequent influence during the homing and establishment of breast cancer-associated bone metastases. Beyond the well-established bone molecules, this chapter also explores the role of other potential factors such as activated leukocyte cell adhesion molecule (ALCAM) and its potential impact on breast cancer cells' affinity for the bone environment, which implies that ALCAM could be a promising therapeutic target.

EPLIN: a fundamental actin regulator in cancer metastasis?

Treatment of malignant disease is of paramount importance in modern medicine. In 2012, it was estimated that 162,000 people died from cancer in the UK which illustrates a fundamental problem. Traditional treatments for cancer have various drawbacks, and this creates a considerable need for specific, molecular targets to overcome cancer spread. Epithelial protein lost in neoplasm (EPLIN) is an actin-associated molecule which has been implicated in the development and progression of various cancers including breast, prostate, oesophageal and lung where EPLIN expression is frequently lost as the cancer progresses. EPLIN is important in the regulation of actin dynamics and has multiple associations at epithelial cells junctions. Thus, EPLIN loss in cancer may have significant effects on cancer cell migration and invasion, increasing metastatic potential. Overexpression of EPLIN has proved to be an effective tool for manipulating cancerous traits such as reducing cell growth and cell motility and rendering cells less invasive illustrating the therapeutic potential of EPLIN. Here, we review the current state of knowledge of EPLIN, highlighting EPLIN involvement in regulating cytoskeletal dynamics, signalling pathways and implications in cancer and metastasis.

WISP-2 in human gastric cancer and its potential metastatic suppressor role in gastric cancer cells mediated by JNK and PLC-γ pathways.

BACKGROUND: It has recently been shown that WISP proteins (Wnt-inducted secreted proteins), a group of intra- and extra-cellular regulatory proteins, have been implicated in the initiation and progression of a variety of tumour types including colorectal and breast cancer. However, the role of WISP proteins in gastric cancer (GC) cells and their clinical implications have not yet been elucidated. METHODS: The expression of WISP molecules in a cohort of GC patients was analysed using real-time quantitative PCR and immunohistochemistry. The expression of a panel of recognised epithelial-mesenchymal transition (EMT) markers was quantified using Q-PCR in paired tumour and normal tissues. WISP-2 knockdown (kd) sublines using ribozyme transgenes were created in the GC cell lines AGS and HGC27. Subsequently, several biological functions, including cell growth, adhesion, migration and invasion, were studied. Potential pathways for the interaction of EMT, extracellular matrix and MMP were evaluated. RESULTS: Overexpression of WISP-2 was detected in GC and significantly correlated with early tumour node-metastasis staging, differentiation status and positively correlated with overall survival and disease-free survival of the patients. WISP-2 expression was inversely correlated with that of Twist and Slug in paired samples. Kd of WISP-2 expression promoted the proliferation, migration and invasion of GC cells. WISP-2 suppressed GC cell metastasis through reversing EMT and suppressing the expression and activity of MMP9 and MMP2 via JNK and ERK. Cell motility analysis indicated that WISP-2 kd contributed to GC cells' motility and can be attenuated by PLC-γ and JNK small inhibitors. CONCLUSIONS: Increased expression of WISP-2 in GC is positively correlated with favourable clinical features and the survival of patients with GC and is a negative regulator of growth, migration and invasion in GC cells. These findings suggest that WISP-2 is a potential tumour suppressor in GC.

YangZheng XiaoJi exerts anti-tumour growth effects by antagonising the effects of HGF and its receptor, cMET, in human lung cancer cells.

BACKGROUND: Hepatocyte growth factor (HGF) is a cytokine that has a profound effect on cancer cells by stimulating migration and invasion and acting as an angiogenic factor. In lung cancer, the factor also plays a pivotal role and is linked to a poor outcome in patients. In particular, HGF is known to work in combination with EGF on lung cancer cells. In the present study, we investigated the effect of a traditional Chinese medicine reported in cancer therapies, namely YangZheng XiaoJi (YZXJ) on lung cancer and on HGF mediated migration and invasion of lung cancer cells. METHODS: Human lung cancer cells, SKMES1 and A549 were used in the study. An extract from the medicine was used. Cell migration was investigated using the EVOS and by ECIS. Cell-matrix adhesion and in vitro invasion were assessed. In vivo growth of lung cancer was tested using an in vivo xenograft tumour model and activation of the HGF receptor in lung tumours by an immunofluorescence method. RESULTS: Both lung cancer cells increased their migration in response to HGF and responded to YZXJ by reducing their speed of migration. YZXJ markedly reduced the migration and in vitro invasiveness induced by HGF. It worked synergistically with PHA665752 and SU11274, HGF receptor inhibitors on the lung cancer cells both on HGF receptor activation and on cell functions. A combination of HGF and EGF resulted in a greater increase in cell migration, which was similarly inhibited by YZXJ, and in combination with the HGF receptor and EGF receptor inhibitors. In vivo, YZXJ reduced the rate of tumour growth and potentiated the effects of PHA665752 on tumour growth. It was further revealed that YZXJ significantly reduced the degree of phosphorylation of the HGF receptor in lung tumours. CONCLUSION: YZXJ has a significant role in reducing the migration, invasion and in vivo tumour growth of lung cancer and acts to inhibit the migratory and invasive effects induced by HGF and indeed by HGF/EGF. This effect is likely attributed to the inhibition of the HGF receptor activation. These results indicate that YZXJ has a therapeutic role in lung cancer and that combined strategy with methods to block HGF and EGF should be considered.

Knockdown of WAVE3 impairs HGF induced migration and invasion of prostate cancer cells.

BACKGROUND: The WASP (Wiskott-Aldrich syndrome protein) and WAVE (WASP Verpolin homologous) family of proteins are structurally related and responsible for regulation of actin polymerization through their interaction with actin related proteins 2&3 (ARP 2/3). WAVE-3 has exhibited an association with disease progression and poorer prognosis of certain malignancies. In the current study, we determined the role of WAVE-3 in hepatocyte growth factor induced cellular changes including cell matrix interaction, invasion and cellular motility, and pathways that may be responsible for the changes in prostate cancer cells. METHODS: We used hammer head ribozymes to knock down the expression of WAVE-3 in PC-3 prostate cancer cell line. In vitro cellular functional assays including growth, invasion, adhesion, motility and invasion, were performed to assess the effects of WAVE-3 knock down. Further experimentation was performed to investigate the role of different pathway through expression and phosphorylation status of various intermediate proteins. RESULTS: WAVE-3 knockdown reduced invasive potential and motility of prostate cancer cells. Following addition of HGF, control cells showed significantly increased invasion and motility (p value <0.5) and marked increase in cellular growth. However, WAVE-3 knockdown cell line failed to show any increase in these trends (p value <0.5) except increased growth compared with control cells. Further experiments revealed that HGF-induced activation of Paxillin was weakened by the knockdown of WAVE-3. Our study also indicated that reduced invasiveness following WAVE-3 knockdown, may be related to reduce activity of MMP-2. CONCLUSIONS: Our studies suggest a vital role of WAVE-3 in HGF induced invasion and migration in which Paxillin and MMP-2 are involved. Further study will shed light on its potential as therapeutic target to suppress local invasion and metastasis of prostate cancer cells.

The role of death-associated protein 3 in apoptosis, anoikis and human cancer.

Death-associated protein 3 (DAP3) is a molecule with a significant role in the control of both apoptosis and anoikis. Apoptosis is the predominant type of programmed cell death (PCD) which may occur in response to irreparable damage to DNA, or in response to induction by inflammatory cells. Anoikis is subset of apoptosis which occurs in epithelial cells in response to detachment from the surrounding matrix. Both apoptosis and anoikis are of interest in the context of carcinogenesis. In this review, we shall discuss apoptosis and anoikis, and the recent literature regarding the role of DAP3 in both these pathways.