A study of circulating anti-CD25 antibodies in non-small cell lung cancer

PURPOSE

Tumors can trigger specific immune response to tumor-associated antigens but the precise mechanism remains unclear. Since regulatory T-lymphocytes (Treg) play a crucial role in controlling autoimmune responses, the present work was undertaken to test whether dysfunction of Treg cells could be involved in developing autoimmunity in patients with lung cancer.

METHODS

In this study, we developed an in-house enzyme-linked immunosorbent assay to test circulating anti-CD25 autoantibodies among 272 patients with non-small cell lung cancer (NSCLC) and 226 control subjects matched in age, gender and smoking history.

RESULTS

Mann-Whitney U test showed that the anti-CD25 IgG level was significantly higher in patients with NSCLC than control subjects (Z = -7.48, P < 0.001) while the anti-CD25 IgA level was not significantly changed in the patient group as compared with the control group (Z = -1.34, P = 0.181). Spearman correlation analysis failed to reveal a significant correlation between the levels of anti-CD25 IgG and IgA either in patients with NSCLC (r = -0.034, P = 0.578) or in control subjects (r = 0.055, P = 0.429). ROC analysis showed an AUC of 0.70 for anti-CD25 IgG, in which NSCLC at stage III had the highest AUC (0.75). The sensitivity against a specificity of >90 % was 35.0 % for anti-CD25 IgG assay with an inter-assay deviation of 9.4 %, and 4.0 % for anti-CD25 IgA assay with an inter-assay deviation of 13.0 %.

CONCLUSIONS

Circulating anti-CD25 IgG antibody may be a useful biomarker for prognosis of lung cancer.

MT-MMPs in pre-eclamptic placenta: relationship to soluble endoglin production

INTRODUCTION

Pre-eclampsia is a serious complication of pregnancy, characterized by severe endothelial dysfunction resulting in hypertension, proteinuria and maternal end-organ damage. Soluble endoglin is an anti-angiogenic factor released from placenta that has been linked to severe pre-eclampsia. We recently reported MMP-14 is capable of cleaving endoglin to release soluble endoglin from placenta, however inhibition studies only partially repressed production. To this end we have sought to identify other proteases that mediate endoglin shedding from placenta. MMP-14 is one of six-membrane-type (MT-) MMPs, a sub-family of the MMP superfamily, so named because they are membrane bound. MMP-15 is phylogenetically the closest MMP relative to MMP-14, however its inhibition has no effect on soluble endoglin production from placenta.

METHODS

Here we aimed to characterize the remaining four MT-MMPs (MMP-16, -17, -24 and -25) in severe early-onset pre-eclamptic placenta and assess their relative contribution to soluble endoglin production.

RESULTS

Immunolocalisation studies revealed MMP-16, -24 and -25 were localized to the syncytiotrophoblast, the same site as endoglin, whilst MMP-17 was predominantly localized to fetal vessels and underlying stroma. MMP-17 protein was significantly (p < 0.05) up-regulated in pre-eclamptic placentas compared to gestationally matched pre-term controls, whilst MMP-25 mRNA was significantly (p < 0.05) down regulated. siRNA knockdown of MMP-16, -17, -24 and -25 in syncytialised BeWo cells did not alter soluble endoglin production in vitro.

CONCLUSION

This is the first study to characterize MT-MMP protein localization in human placenta and indicates that MMP-14 is the only MT-MMP that contributes to soluble endoglin production in pre-eclampsia.

Abstract P1-04-03: Knocking down Suppressor of Cytokine Signaling 7 in breast cancer: The role in Insulin-like Growth Factor - I/Phospholipase Cγ-1 signaling

BACKGROUND: Suppressor of Cytokine Signaling 7 (SOCS7) is a member of the SOCS family and is known to interact with Phospholipase Cγ-1 (PLCγ-1), one of the Insulin like Growth Factor - I (IGF-I) receptor downstream molecules. In the present study, we sought to examine the effect of knocking down SOCS7 gene on breast cancer cells growth and migration and to elucidate whether this has involved IGF-I — PLCγ-1 signaling using the PLCγ-1 blocker U73122.

METHODS: Suitable breast cancer cells (MCF7 and MDA-MB-231) were transfected with anti-SOCS7 ribozymal transgene, to create sublines with SOCS7 knockdown that was verified by RT-PCR. The growth and migration of the cells were evaluated in the presence or absence of IGF-I and PLCγ-1 inhibitor using in vitro growth assay and Electrical Cell Impedance Sensing (ECIS) migration assay.

RESULTS: MCF7ΔSOCS7 and MDA-MB-231ΔSOCS7 (SOCS7 knockdown) were constructed. Both sublines showed a higher rate of growth compared to control cells with and without IGF-I stimulation. U73122 treatment did not appear to change this growth outcome. Using ECIS migration assay, it was shown that knocking down SOCS7 had a significant positive effect on the migration of MCF7 and MDA-MB-231 cells, and that both IGF-I treatment and SOCS7 knockdown had a synergistic positive influence on their migration (p &lt; 0.05). We further demonstrated that the impact of U73122 on the IGF-I migratory effect was dependent upon SOCS7 knockdown as it has significantly blocked the stimulatory effect of IGF-I on MCF7ΔSOCS7 and MDA-MB-231ΔSOCS7 migration but not that of the control cells. While SOCS7 has acted to control the IGF-I effect, it appeared to cancel the inhibitory function of U73122, indicating a specific anti - PLCγ-1 role for SOCS7 in IGF-I induced breast cancer cellular migration.

CONCLUSION: SOCS7 loss resulted in increased growth and migration of breast cancer cells and this had a synergistic effect on their response to IGF-I. This role could be related to its interaction with PLCγ-1 during the cellular migration but not the growth. It may be possible that SOCS7 acts through different mechanism to control the cellular growth.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-04-03.

Lower incidence and severity of tomato virus in elevated CO(2) is accompanied by modulated plant induced defence in tomato

Elevation in atmospheric CO(2) concentration broadly affects plant phenology and physiology, and these effects may alter the performance of plant viruses. The effects of elevated CO(2) on the susceptibility of tomato plants to Tomato yellow leaf curl virus (TYLCV) were examined for two successive years in open top chambers (OTC) in the field. We experimentally tested the hypothesis that elevated CO(2) would reduce the incidence and severity of TYLCV on tomato by altering plant defence strategies. Our results showed that elevated CO(2) decreased TYLCV disease incidence (by 14.6% in 2009 and 11.8% in 2010) and decreased disease severity (by 20.0% in 2009 and 10.4% in 2010). Elevated CO(2) also decreased the level of TYLCV coat protein in tomato leaves. Regardless of virus infection, elevated CO(2) increased plant height and aboveground biomass. Additionally, elevated CO(2) increased the leaf C:N ratio of tomato, but decreased soluble protein content in leaves. Notably, elevated CO(2) increased the salicylic acid (SA) level in uninfected and infected plants. In contrast, elevated CO(2) reduced jasmonic acid (JA) in uninfected plants while it increased JA and abscisic acid (ABA) in virus-infected plants. Furthermore, combined exogenous SA and JA application enhanced resistance to TYLCV more than application of either SA or JA alone. Our results suggest that the modulated antagonistic relationship between SA and JA under elevated CO(2) makes a great contribution to increased tomato resistance to TYLCV, and the predicted increases in tomato productivity may be enhanced by reduced plant virus susceptibility under projected rising CO(2) conditions.

MicroRNA-520e suppresses growth of hepatoma cells by targeting the NF-κB-inducing kinase (NIK)

MicroRNAs (miRNAs) are small, non-coding RNAs that can act as oncogenes or tumor suppressor genes in human cancer. Emerging evidence indicates that deregulation of miRNAs contributes to the hepatocarcinogenesis. In the present study, we demonstrated that the levels of miR-520e were dramatically decreased in examined hepatoma cell lines and clinical hepatocellular carcinoma (HCC) tissues. Moreover, we found that DNA hypermethylation in the upstream region of miR-520e resulted in the downregulation of miR-520e. Next, we demonstrated that introduction of miR-520e dramatically suppressed the growth of hepatoma cells in vitro and in vivo, whereas silencing the expression of miR-520e by anti-miR-520e resulted in a promoted cell proliferation, suggesting that miR-520e may be a novel tumor suppressor. Further studies revealed that NF-κB-inducing kinase (NIK) was one of the direct target genes of miR-520e, as miR-520e directly bound to the 3'untranslated region of NIK, which reduced the expression of NIK at the levels of mRNA and protein. Moreover, silencing of NIK was able to inhibit the growth of hepatoma cells, similar to the effect of miR-520e overexpression on growth of hepatoma cells. Meanwhile, the knockdown of NIK expression reversed the enhanced proliferation mediated by anti-miR-520e. In addition, miR-520e significantly decreased the phosphorylation of ERK1/2 (p-ERK1/2) and depressed the transcriptional activity and nuclear translocation of nuclear factor κB (NF-κB) (p65). These results suggest that miR-520e suppresses the growth of hepatoma cells by targeting NIK involving the NIK/p-ERK1/2/NF-κB signaling pathway. Finally, we showed that the intratumoral injection with miR-520e was able to directly repress the growth of hepatoma cells in the nude mice. Thus, our finding provides new insight into the mechanism of hepatocarcinogenesis, indicating a therapeutic potential of miR-520e in the treatment of HCC.

CFTR suppresses tumor progression through miR-193b targeting urokinase plasminogen activator (uPA) in prostate cancer

Cystic fibrosis (CF) transmembrane conductance regulator (CFTR) is expressed in the epithelial cells of a wide range of organs/tissues from which most cancers are derived. Although accumulating reports have indicated the association of cancer incidence with genetic variations in CFTR gene, the exact role of CFTR in cancer development and the possible underlying mechanism have not been elucidated. Here, we report that CFTR expression is significantly decreased in both prostate cancer cell lines and human prostate cancer tissue samples. Overexpression of CFTR in prostate cancer cell lines suppresses tumor progression (cell growth, adhesion and migration), whereas knockdown of CFTR leads to enhanced malignancies both in vitro and in vivo. In addition, we demonstrate that CFTR knockdown-enhanced cell proliferation, cell invasion and migration are significantly reversed by antibodies against either urokinase plasminogen activator (uPA) or uPA receptor (uPAR), which are known to be involved in various malignant traits of cancer development. More interestingly, overexpression of CFTR suppresses uPA by upregulating the recently described tumor suppressor microRNA-193b (miR-193b), and overexpression of pre-miR-193b significantly reverses CFTR knockdown-enhanced malignant phenotype and abrogates elevated uPA activity in prostate cancer cell line. Finally, we show that CFTR gene transfer results in significant tumor repression in prostate cancer xenografts in vivo. Taken together, the present study has demonstrated a previously undefined tumor-suppressing role of CFTR and its involvement in regulation of miR-193b in prostate cancer development.

Arrhythmia and sudden death associated with elevated cardiac chloride channel activity

The identification and analysis of several cationic ion channels and their associated genes have greatly improved our understanding of the molecular and cellular mechanisms of cardiac arrhythmia. Our objective in this study was to examine the involvement of anionic ion channels in cardiac arrhythmia. We used a transgenic mouse model to overexpress the human cystic fibrosis transmembrane conductance regulator (CFTR) gene, which encodes a cAMP-regulated chloride channel. We used RNase protection and in situ hybridization assays to determine the level of CFTR expression, and radiotelemetry and in vivo electrophysiological study in combination with pharmacological intervention to analyse the cardiac function. Cardiac CFTR overexpression leads to stress-related sudden death in this model. In vivo intracardiac electrophysiological studies performed in anaesthetized mice showed no significant differences in baseline conduction parameters including atrial-His bundle (AH) or His bundle-ventricular (HV) conduction intervals, atrioventricular (AV) Wenckebach or 2:1 AV block cycle length and AV nodal functional refractory period. However, following isoproterenol administration, there was marked slowing of conduction parameters, including high-grade AV block in transgenic mice, with non-sustained ventricular tachycardia easily inducible using programmed stimulation or burst pacing. Our sudden death mouse model can be a valuable tool for investigation of the role of chloride channels in arrhythmogenesis and, potentially, for future evaluation of novel anti-arrhythmic therapeutic strategies and pharmacological agents.

New precision limit on the strange vector form factors of the proton

The parity-violating cross-section asymmetry in the elastic scattering of polarized electrons from unpolarized protons has been measured at a four-momentum transfer squared Q2 = 0.624  GeV2 and beam energy E(b) = 3.48  GeV to be A(PV) = -23.80 ± 0.78(stat) ± 0.36(syst) parts per million. This result is consistent with zero contribution of strange quarks to the combination of electric and magnetic form factors G(E)(s) + 0.517G(M)(s) = 0.003 ± 0.010(stat) ± 0.004(syst) ± 0.009(ff), where the third error is due to the limits of precision on the electromagnetic form factors and radiative corrections. With this measurement, the world data on strange contributions to nucleon form factors are seen to be consistent with zero and not more than a few percent of the proton form factors.

Investigation of the relationship between SLA-1 and SLA-3 gene expression and susceptibility to Escherichia coli F18 in post-weaning pigs

Porcine post-weaning diarrhea and edema disease are principally caused by Escherichia coli strains that produce F18 adhesin. FUT1 genotyping and receptor binding studies divided piglets into E. coli F18-resistant and -sensitive groups, and the roles of SLA-1 and SLA-3 were investigated. SLA-1 and SLA-3 expression was detected in 11 pig tissues, with higher levels of SLA-1 in lung, immune tissues and gastrointestinal tract, and higher levels of SLA-3 also in lung and lymphoid tissues. Both genes were expressed higher in F18-resistant piglets, and their expression was positively correlated in different tissues; a negative correlation was observed in some tissues of F18-sensitive group, particularly in lung and lymphatic samples. Gene ontology and pathway analyses showed that SLA-1 and SLA-3 were involved in 37 biological processes, including nine pathways related to immune functions. These observations help to elucidate the relationship between SLA class I genes and E. coli F18-related porcine gastrointestinal tract diseases.

P5-07-07: Follistatin Suppresses In Vitro Growth of Breast Cancer Cells and Its Reduced Expression in Breast Cancer Associated with Poor Differentiation and Prognosis

Background: Bone morphogenetic protein (BMP) belongs to TGF-β superfamily, being widely involved in prenatal and postnatal development and homeostasis of various tissues and organs. BMP signaling has been implicated in tumorigenesis and disease progression of certain malignancies. Recent studies demonstrated a profound role played Noggin, a BMP antagonist in bone metastasis from breast cancer. Current study examined expression of Follistatin, another BMP antagonist in a breast cancer cohort, and its relevance to pathological and clinical parameters.

Methods: Expression of Follistatin was examined in breast cancer tissues (n=93) and normal background tissues (n=30) using quantitative real time PCR and immunhistochemistry (IHC). The breast tissue samples were collected immediately after surgery. The clinical follow-up was routinely performed after surgery. The median follow-up period was 120 months (June 2004). Full-length human Follistatin coding sequence was cloned into a plasmid vector. Following transfection and verification, effect of Follistatin overexpression on cell growth was examined using an in vitro growth assay.

Results: IHC revealed cytoplamic staining of Follistatin in mammary epithelial cells in breast tissues. The staining appeared to be weaker in breast cancer, but there was no significant difference in its transcripts levels compared with that of normal background tissues. Follistatin transcripts were decreased in both moderately differentiated and poorly differentiated tumors, p=0.0165 and p=0.0169 in comparison with well differentiated tumors respectively. Transcript levels of Follistatin in primary tumors tended to be lower in the patients with poor prognosis (33.8±14.7) including those patients had local recurrence, metastases and died of breast cancer, p=0.09 when compared with that of patients remained disease free (117.0±46.0). Its expression appeared particularly lower in the patients died of the disease (21.8±12.0), p=0.05 v.s. disease free. Over-expression of Follistatin exerted inhibitory effect on in vitro growth of MDA-MB-231 cells.

Conclusions: Decreased expression of Follistatin in primary tumors of breast cancer correlates with poorer differentiation and mortality. Follistatin suppresses in vitro growth of breast cancer cells. It suggests that Follistatin is a negative regulator for tumor growth and disease progression of breast cancer.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-07-07.

P2-05-05: Receptor-Like Protein Tyrosine Phosphatase Kappa (PTPRK) and Its Biological Role in Angiogenesis

Introduction: Protein Tyrosine Phosphatases (PTPs) are known as signalling molecules which affect cell growth, differentiation and oncogenic transformation. PTPs have been indicated in tumourigenesis and progression of various solid tumours. PTPRK, receptor-type protein tyrosine phosphatase kappa, has been shown to down-regulate transcriptional activity of beta-catenin and impact distribution of beta-catenin/E-cadherin complexes on cancer cell membrane. However, the role played by PTPRK in angiogenesis remains unknown. In present study, the effect of PTPRK knock-down on functions and tubule formation ability of HECV cells was investigated. (or In the present study, the effect of PTPRK on angiogenesis process was investigated.)

Methods: anti-PTPRK ribozyme transgenes were constructed to knock-down PTPRK expression in vascular endothelial cells, HECV cells. The subsequent effect upon in vitro cell growth, adhesion, migration and microvascular tubule formation was examined using a variety of functional assays.

Result: Knock-down PTPRK in HECV cells (HECVΔPTPRK) resulted in a decrease of cell growth in vitro. The growth rate of HECVΔPTPRK was 276.3±16.4, p=0.01 compared with HECVpEF (314.8±21.9) controls. However, knock-down of PTPRK in HECV cells increased cell motility. The cell migration distance of HECVΔPTPRK was 83.8±19.8μm, p=0.008 compared with HECVpEF (61.8±11.8μm) controls. No effect on cell adhesion by PTPRK knockdown was seen in HECVΔPTPRK (81.2±6.6), compared with HECVpEF control (78.8±15.6). Furthermore, knock-down of PTPRK suppressed tubule formation in HECV cells, the length of total tubules (μm) in HECVΔPTPRK was 2167.4±943.2, p&lt;0.05 compared with HECVpEF (3130.6±386.9) control.

Conclusion: Knock-down of PTPRK reduced the growth and tubule formation abilities of vascular endothelial cells. It suggests that PTPRK is pivotal regulator for angiogenic process. Further investigations are required to identify the downstream pathways involved in these impacts.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-05-05.

P2-01-19: Expression of Receptor Like Protein Tyrosine Phosphatases mu (PTPRM) in Breast Cancer and the Biological Effects of PTPRM on Breast Cancer Cells

Introduction: Protein tyrosine phosphatases (PTPs) play a major role in many cellular functions including cell survival, proliferation, differentiation and motility. The receptor-like protein tyrosine phosphatase mu (PTPRM) has a similar structure to cell-cell adhesion molecules and has been shown to exhibit homophilic binding and confer cell-cell adhesion in cells including epithelial and cancer cells. However, the role played by PTPRM in breast cancer remains unclear. The present study investigated the expression of PTPRM in breast cancer and the biological impact of PTPRM on breast cancer cells.

Methods: Expression of PTPRM protein and gene transcript was examined in a cohort of primary breast cancer tumours. The association of PTPRM transcripts level and pathological and clinical aspects was then analysed. Expression of PTPRM transcript in breast cancer cells were knocked down using a specific anti-PTPRM transgene. The impact of PTPRM knockdown on breast cancer was evaluated using a series of in vitro cell models and in vivo tumour model.

Result: PTPRM protein was seen generally distributed in the breast tissues, including tumours and normal background tissues. A stronger staining was revealed in cytoplasm of both mammary epithelia and cancer cells in comparison with the surrounding stromal cells. A significantly decrease was seen in poorly differentiated tumours (92.5±279), and moderately differentiated tumours (288±110), compared with that of well differentiated (472±114), p=0.011 and p=0.031 respectively. PTPRM transcript levels were decreased in patients died from breast cancer. The expression of PTPRM transcripts was significantly associated with disease free survival. Patients with lower expression of PTPRM had shorter survival compared with those with high level of PTPRM expression (p=0.029). Knocking down PTPRM from breast cancer cells significantly increased cell adhesion compared with control cells (p&lt;0.001). Likewise, the knockdown also marked increase the rate of cell migration (102.9±11.3μm for control vs 115.3±10.5μm for PTPRM knockdown, p&lt;0.05).

Conclusion: The expression of PTPRM transcripts is decreased in poorly differentiated breast tumours and is correlated with poorer long term survival. This is likely to be contributed to by the biological impact of PTPRM on the aggressiveness of breast cancer cells.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-01-19.

P3-18-01: cMET Inhibitor and the Inhibition of Growth of Breast Cancer Cells in Bone Marrow Matrix Environment

Background: Hepatocyte growth factor (HGF) is a cytokine that has a diverse but potential role in cancer including breast cancer. HGF, which action is mediated by its specific receptor, cMET, stimulate the aggressiveness of cancer cells by increasing the invasiveness and cellular migration. HGF is also a potent angiogenic factor. Small inhibitors to the HGF receptor are currently investigated in clinical trials of various cancers. In solid tumours which have potency of bone metastasis, HGF and particularly the HGF receptor, cMET, have been found to be particularly over-expressed in tumour cells metastasised to bones.

Materials and methods. A panel of breast cancer cell lines were used. Cell growth was determined using a colorimetic method. Cell adhesion and migration were investigated using a ECIS model. Bone matrix proteins were prepared from fresh bones. A small inhibitor to human cMET, PF02341066 was used in the present study in all the cell models.

Results. Depending on cell types, cancer cells tended to grow at a faster rate in bone marrow microenvironment than under normal conditions (12% higher for MDA MB 231 cells, for example). While PF02341066 have a concentration dependent effect on the growth of breast cancer, this effect became more marked when cells were growing in the bone marrow matrix. Breast cancer cells migrated rapidly in the presence of bone marrow environment, in comparison with controls. This was also inhibited by the cMET inhibitor. The study further showed that cells over-expressing a molecule linked to bone metastasis, namely ALCAM (1,2), responded more vigorously to cMET inhibitor in the matrix adhesion and cellular migration.

Conclusions. The present study has shown that the HGF receptor inhibitor has an inhibitory effect on breast cancer cells. This is particularly so when cells are grown in bone matrix microenvironment. It is concluded therefore that inhibitors to the HGF receptor may have a particular role in the management of bone metastasis in breast cancer.

References: 1. Davies S, Jiang WG. ALCAM, activated leukocyte cell adhesion molecule, influences the aggressive nature of breast cancer cells, a potential connection to bone metastasis. Anticancer Res. 2010, 30(4):1163–8; 2. King JA, et al. Activated leukocyte cell adhesion molecule in breast cancer: prognostic indicator. Breast Cancer Res. 2004;6(5):R478–87

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-18-01.

P1-01-08: Expression of Interleukin-15 (IL-15) and the IL-15 Receptor in Human Breast Cancer

Introduction: Interleukin-15 (IL15) is a cytokine that influences activation and proliferation of T-lymphocytes. IL-15 is produced in the body leukocytes such as phagocytes and in many ways has similar immunoregulatory functions to IL-2 including stimulation of NK cells and CD8(+) T cells. It has been suggested that IL-15 may increase the immunity to cancer cells and cancer cell's response to therapeutic agents. IL-15 has also been shown to be able to inhibit tumour growth in vivo. However, the expression profile of IL-15 and IL-15 receptor (IL-15) in solid tumours including human breast cancer is not clear. The present study investigated the expression profile of both IL-15 and IL-15R in human breast cancer and deduced a clinical and pathological relevance with breast cancer.

Methods: Immunohistochemical methods were used to detect IL-15 and IL-15RA in mammary tissues. IL-15 and IL-15RA transcripts were analysed using real-time quantitative PCR method. Levels of IL-15 and IL-15RA were compared in normal and tumour tissues as well as against tumour staging, nodal status, disease progression and clinical outcome after a 10-year followup.

Results: Both IL-15 and IL-15RA were detectable in mammary tissues and were seen in both epithelial cells and infiltrating cells. Node positive tumours had low levels of IL-15 compared with node negative tumours (21.7±10 vs 103±46, respectively). Late stage tumour also had lower levels of IL-15 (95±43, 31±15, 3.7±2 and 1.3±1.15 for stage I, II, III and IV tumours respectively. p=0.036 and p=0.032, stage-II and Stage-III vs stage-I). Patients with metastatic disease (10.3±3) and patients died of breast cancer related conditions (8.5±6) had markedly low levels of IL-15 when compared with those who were disease free (54.7±25). The disease free survival time for patients with low levels IL-15 was 126 (114-138, 95%CI) months, compared with 139 (131-148) months for those with high levels of IL-15. Despite the reduced expression of IL-15 in aggressive tumours, expression of IL-15 receptor, IL-15RA, did not display a significant change and failed to showed a link with nodal status, tumour staging and clinical outcome.

Conclusions: Interleukin-15, an immuoregulatory cytokine, has an aberrant expression in human breast cancer. Low levels of IL-15, but not IL-15 receptor, is associated with the aggressiveness and disease progression of breast cancer. Together with reported effect of IL-15 on NK cells and other anti-tumour lymphocytes, IL-15 appears to be a useful therapeutic option.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-01-08.

P2-05-06: Role of Repulsive Guidance Molecule b (RGMb) in HGF Mediated Angiogenesis

Introduction: Hepatocyte Growth Factor (HGF) has been widely documented as playing a key role in enhancing the aggressive nature of cancer through its ability to promote cellular processes such as migration, invasion and angiogenesis. Development of a blood supply is vital to advanced tumour growth and increased metastatic potential. In the current study we identified RGMb (DRAGON), a member of the Repulsive Guidance Molecule family, as being upregulated by HGF and assessed its potential to contribute to HGF mediated proangiogenic traits.

Methods: Expression of RGMb was identified as being upregulated in human endothelial HECV cells following 4 hour treatment with HGF (40ng/ml) using micro array analysis and Q-PCR. Subsequently, the expression of RGMb was targeted through the transfection of HECV cells with a plasmid containing a ribozyme transgene specifically targeted to RGMb. The role of RGMb in HGF mediated cellular migration and tubule formation in vitro was examined.

Results: Significant increases in RGMb expression in HECV cells were observed on the mirco-array following 4 hour treatment with HGF (P = 0.004) and this trend was also identified using Q-PCR. Transfection with the ribozyme transgene brought about substantial reductions in RGMb expression at both transcript and protein levels as assessed using RT-PCR, QPCR and Western blot analysis. Knockout of RGMb brought about a significant increase in migration rates, compared to HECV cells transfected with a closed pEF6 plasmid only (HECVpEF6), following a 90minute period (p = 0.034 at 90 minute time point vs pEF6 control). Treatment of HGF enhanced migration rates of HECV control cells with significant differences between untreated and HGF treated pEF6 cells obvious following 60 minutes (p &lt; 0.05 at 60 and 75 minutes, p = 0.002 at 90 minutes). In contrast to this, HECV cells transfected with the RGMb ribozyme transgene (HECVRGMbKO) were unaffected by HGF treatment, with no significant differences observed between treated or untreated HECVRGMbKO cells at any time points. A similar trend was observed in the angiogenic tubule formation assay, where treatment of HECVpEF6 cells with HGF could significantly enhance the levels of tubules formed (mean tubule perimeter, untreated 8087+/− 632 vs HGF treated 13131+/− 988, p = 0.001). Treatment of HECVRGMbKO cells with HGF did not significantly enhance levels of tubule formation (mean tubule perimeter, untreated 7523+/−2458 vs HGF treated 11050+/−1512, p = 0.21).

Conclusions: Targeting of RGMb in endothelial cells appears to reduce their sensitivity to the promotional effect of HGF on cell migration and tubule formation, important traits in the angiogenic cascade. Our data suggests that RGMb may be one molecule involved in the process through which HGF enhances angiogenic potential and targeting this molecule may be a useful strategy in a number of cancer types to interfere with HGF promoted angiogenesis.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-05-06.

Polymorphism of M307 of the FUT1 gene and its relationship with some immune indexes in Sutai pigs (Duroc x Meishan)

The alpha (1,2)fucosyltransferase (FUT1) gene has been identified as a candidate gene for controlling the expression of the enterotoxigenic Escherichia coli (ETEC) F18 receptor. Polymorphisms were detected at the M307 position in FUT1 of a breeding base population of Sutai pigs and their correlations to immune parameters analyzed. After digestion by Hin6I, three genotypes were identified at M307, AA (frequency 0.235), AG (0.609), and GG (0.156), with significant deviation from Hardy-Weinberg equilibrium (P < 0.01). The hemoglobin and white blood cell count of the AA genotype pigs were significantly higher than those of AG and GG pigs (P < 0.05). The results indicated that AA pigs not only are resistant to edema disease and post-weaning diarrhea in piglets but also have relatively strong resistance to disease in general.

Performance of sequential organ failure assessment, logistic organ dysfunction and multiple organ dysfunction score in severe sepsis within Chinese intensive care units

This study assessed the performance of Sequential Organ Failure Assessment, Logistic Organ Dysfunction Score and Multiple Organ Dysfunction Score in outcome prediction in severe sepsis. A total of 528 consecutive patients with a diagnosis of severe sepsis were enrolled from two surgical intensive care units of university hospitals in China. Clinical and laboratory data of patients were collected and admission and maximum values of each scoring system were calculated. Areas under the receiver operating characteristic curve, which were used to assess discrimination, were 0.80, 0.83 and 0.74 for admission Sequential Organ Failure Assessment, Logistic Organ Dysfunction Score and Multiple Organ Dysfunction Score respectively, and 0.91, 0.93 and 0.86 for corresponding maximum values respectively. Calibration assessed by the Hosmer-Lemeshow statistic was better with admission (chi2 = 18.2) and maximum Logistic Organ Dysfunction Score (chi2 = 19.6) than with admission (chi2 = 98.1) and maximum Multiple Organ Dysfunction Score (chi2 = 30.9). Brier Scores, indicating the overall performance of the scores, were 0.18, 0.17 and 0.22 for admission Sequential Organ Failure Assessment, Logistic Organ Dysfunction Score and Multiple Organ Dysfunction Score respectively, and 0.12, 0.10 and 0.15 for their maximum counterparts respectively. This study found good performance of both admission Sequential Organ Failure Assessment and Logistic Organ Dysfunction Score in severe sepsis, and a slightly weaker performance of admission Multiple Organ Dysfunction Score. Since poor calibration was observed in Logistic Organ Dysfunction Score and Multiple Organ Dysfunction Score, we suggest further study of customisation of these scores in critical illness with severe sepsis.

Could nitrite/free nitrous acid favour GAOs over PAOs in enhanced biological phosphorus removal systems?

Enhanced biological phosphorus removal (EBPR) normally occurs together with nitrogen removal in wastewater treatment plants (WWTPs). In recent years, efforts have been devoted to remove nitrogen via the nitrite pathway (oxidation of ammonia to nitrite and reduction of nitrite to nitrogen gas without going through nitrate), reducing the requirement for carbon and oxygen in the plant. However nitrite and free nitrous acid (FNA), the protonated species of nitrite, have been shown to cause EBPR deterioration under certain concentrations. This study provides a direct comparison between the different levels of FNA inhibition in the aerobic processes of polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) by reviewing the studies published in this area. Also, new data is presented assessing the FNA effect on the anaerobic metabolism of these two groups of bacteria. Overall, FNA has shown inhibitory effects on most of the processes involved in the metabolism of PAOs and GAOs. However, the inhibition-initiation levels are different between different processes and, even more importantly between the two groups. In general, PAOs appear to be more affected than GAOs at the same level of FNA, thus giving GAOs competitive advantage over PAOs in EBPR systems when nitrite is present.

Abstract P1-02-05: EPLIN? Can Negatively Impact on Angiogenesis and Is Associated with ERK Signalling

Background: EPLIN (epithelial protein lost in neoplasm) is a cytoskeletal associated protein involved in regulating actin dynamics and cell motility. EPLIN expression is frequently lost in cells as they progress to a cancer state and this loss may account for enhanced cancer cell motility. EPLIN has also been shown to be lost in clinical breast cancer, which is associated with patients clinical outcome. Recently, EPLIN has been linked to ERK signalling. This study examined the potential of EPLIN to influence the angiogenesis process and its links to ERK in endothelial cells Methods: Over-expression of EPLIN α was achieved through transfection of the vascular endothelial cell, HECV, with a mammalian expression construct containing the full coding sequence of EPLINα. Enhanced levels of EPLINα were verified through RT-PCR, Q-PCR and Western blot analysis before assessing the angiogenic potential of control and transfected cells using angiogenesis and cell migration models. Treatment of transfected and control cells with ERK inhibitor was used to assess the potential interaction between EPLINα and ERK in endothelial cells. Results: Substantial enhancement in EPLINα expression was seen in transfected cells compared to control cells at both transcript and protein level. Over-expression of EPLINα in HECV endothelial cells resulted in a reduced capacity, compared to control, of these cells to form tubule like structures in an in vitro angiogenesis tubule formation assay (6566 +/− 856µm tubule perimeter of control cells vs 2881 +/− 546µm EPLINα overexpressing HECV cells, p = 0.007). This was seen together with a reduced cell migration following overexpression of EPLINα in the cells. Treatment of control cells with ERK inhibitor significantly reduced tubule formation (3537 +/− 277µm tubule perimeter of ERK inhibitor treated control cells vs 6566 +/− 856µm total perimeter of untreated control cells, p = 0.01), however treatment of HECV cells transfected with EPLINα expression construct caused tubule formation levels to return to control levels (6566 +/− 856µm tubule perimeter of untreated control cells vs 5326 +/− 784µm tubule perimeter of ERK inhibitor treated EPLINα overexpressing HECV cells, p = 0.317).

Discussion: EPLINα can negatively influence tubule formation in vitro and thus may impact on the angiogenesis process. Furthermore, its impact on tubule formation appears to be linked to ERK signalling. Together, this study suggests a role for EPLINα in angiogenesis, which may be linked with ERK signalling.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-02-05.

Abstract P2-07-07: Ehm2 Influences the Aggressiveness of Breast Cancer Cells through Regulation of MMP-9 Expression, and Aberrant Expression of Ehm2 Correlates with Disease Progression in Breast Cancer

Background. Ehm2 is a member of NF2/ERM/4.1 superfamily and has been indicated in cell membrane/cytoskeletal interaction and cellular motility. In the present study, we investigated the expression pattern of Ehm2 in breast cancer and the impact of Ehm2 on the biological behavior of breast cancer cells.

Methods. A cohort of breast cancer specimens (normal, n=33; cancer, n=127) was tested for Ehm2 expression, using both quantitative real time PCR and immunohistochemical staining. A hammerhead ribozyme transgene was employed to knockdown Ehm2 expression in breast cancer cells. The effect on growth, cell matrix adhesion, motility and invasion by Ehm2 knockdown was then examined using in vitro assays. Results. Immunohistochemical staining and quantitative real time PCR revealed an increased expression of Ehm2 in breast cancer. High levels of Ehm2 transcripts correlated with disease progression, metastasis and poor prognosis. Disease free survival of the patients with lower level of Ehm2 was 135.8 (125.1-146.5, 95%CI) months, significantly longer compared with 102.5 (78.7-126.4, 95%CI) months of patients with higher level of Ehm2 expression, P=0.039. Knockdown of Ehm2 had inhibitory effects on both in vitro growth and invasion of breast cancer cells. Flow cytometric analysis showed that knockdown of Ehm2 resulted in an increase (&gt;10%) of apoptotic cells overthe control cells. Furthermore, it was shown that knockdown of Ehm2 significantly decreased the protein and mRNA expression of matrix metalloprotease MMP9. Zymograhpy revealed a reduced activity of MMP9 in breast cancer cells after knockdown of Ehm2.

In conclusion, Ehm2 is able to promote invasion of cancer cells via regulating MMP9, and can also protect them from apoptosis. This may have important implication in the correlation between increased Ehm2 expression and poor prognosis and metastasis in breast cancer.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-07-07.

Abstract P1-04-02: The Role of BIK (BCL-2 Interaction Killer) Pro-Apoptotic Gene in Breast Cancer

Background: The human BIK (BCL-2 interaction killer) gene is a pro-apoptotic member in the Bcl-2 gene family. The BIK gene encodes a Mr 18,000 protein product, which contains a BH3 domain critical for its pro-apoptotic activities. Bik forms heterodimers with various anti-apoptotic proteins, including Bcl-2 and Bcl-XL, the association of which hinders the function of the anti-apoptotic proteins. Fluorescent in-situ hybridization has established the chromosomal localization of the BIK gene to 22q13.3. Recent evidence also reveals that oestrogen starvation-induced apoptosis of breast cancer cells requires BIK.

Methods: Breast cancer tissues (n = 122) and Normal background tissues (n = 33) were collected post surgery. Q-PCR was performed on these tissues to quantify BIK transcript levels in both tissue samples. For in vitro tests, MDA-MB-231 wild type (WT) cell was transfected with anti-BIK ribozyme transgenes, constructed based on the secondary structure of BIK and specifically targeted human BIK, in order to generate a BIK-knockdown subline. The successful knock down of the gene transcript was then verified with RT-PCR and Quantitative real time PCR (Q-PCR) alongside control MDA-MB-231 WT and MDA-MB-231 pEF cells. Cell functions; cell growth using a colorimetric growth assay and cellular motility using conventional scratch wounding assay were tested. Results: Median BIK levels on the normal background and breast cancer tissues were 0.827 and 1.23 respectively being non-significant on Mann-Whitney U test(p=0.27). Patients with higher histological grade (Grade3) (n=55, median 1.53) and TNM4 (n= 4, median= 9.75) demonstrated relatively higher levels of BIK. Tumours from patients with a poor prognosis (Nottingham prognostic index (NPI)&gt;5.4) (n=15, median=2.54) had higher level of BIK transcripts in comparison with patients with good prognosis (NPI&lt;3.4) (n = 65, Median = 1.010), P&lt;0.05. Overall mean survival for patients with low levels of BIK was 139.1 months and 119.2 months for those with high levels. The disease free survival was 133.5 and 113.2 months for patients with low and high levels of BIK, respectively. In vitro, breast cancer cells MDA MB-231 expressed BIK transcript as shown by both RT-PCR and Q-PCR. The anti-BIK transgene successfully knocked down of BIK transcript in the cells. Using a scratch wounding assay and growth assays, it was shown that there was an increase in the rate of migration and growth in the BIK knockdown cells compared to control cell lines.

Conclusion: BIK is a recognized apoptosis promoting gene in breast cancer. Our cohort of breast cancer patients showed a correlation of increased levels of BIK with advancing disease, which also correlates to the estimated overall and disease free survival times. Together with the results from in vitro tests, it is postulated that BIK played a complex role in breast cancer and that the type of interactions with other apoptosis interaction regulators of BIK may be key in deciding the aggressiveness of breast cancer cells.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-04-02.

Abstract P5-05-11: The Cellular Impact of HuR (Human (Hu) Antigen R) in Breast Cancer Cells on the Growth and Invasion In Vitro and the Expression of Cyclin D1 and MMP-9

Introduction: HuR, a ubiquitously expressed member of the Hu family, selectively binds and stabilizes ARE-containing mRNAs encoding proto-oncogenes, cell cycle regulators, cytokines and growth factors. The role of HuR and its cellular function in breast cancer remains unclear. In the present study, we aimed to provide new insights into the molecular and cellular implication of HuR in breast cancer.

Materials and methods. We first constructed a set of anti-HuR ribozyme transgenes that targeted human HuR. Breast cancer cells were transfected with the transgene, in order to establish new sublines with HuR expression knocked down. Cell growth and invasiveness were investigated using in vitro cell models. The expression of cyclin-D1 and MMP2 were determined using immunocytochemistry, Western blotting and polymerase chain reaction.

Results: Here, we show that MCF7 and MDA-MB-231 cells breast cancer cells stability transfected with a hammerhead ribozyme transgene specifically targeted to HuR (MCF7HuRKO and MDA-MB-231HuRKO) have a reduction in HuR expression both at mRNA and protein levels. Using these new sublines of breast cancer cells, the in vitro growth was evaluated. We showed that that HuR knockdown dramatically reduced cell growth in MCF7 cells (P &lt; 0.001) and to a lesser degree reduced that in MDA MB 231 cells. We further demonstrated that reduction of HuR in MDA MB 231 cells (MDA-MB-231HuRKO) resulted in a significant reduction of the in vitro invasiveness in MDA-MB-231 cells (P &lt; 0.001), although the same failed to occur to MCF-7 cells. Furthermore, we found that the decreased cell growth rate in MCF7 cells following HuR knockdown was seen together with a reduction in cyclin D1 transcript and protein levels. It was also interest to observe that the change in invasiveness in MDA-MB-231 cells after HuR knockdown was accompanied by a decrease in MMP-9 levels.

Conclusion: Our study shows that targeting HuR can influences breast cancer cell growth and invasion and suggests a role for HuR in vitro in enhancing breast cancer cell growth and invasion. These changes may be facilitated through changes in the level of cyclin D1 and MMP-9.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-05-11.

Cyclosporin A inhibits hepatitis C virus replication and restores interferon-alpha expression in hepatocytes

Hepatitis C virus (HCV) infection is the leading indication for liver transplantation and a major cause of graft failure. This study investigated whether cyclosporin A (CsA), a widely used immunosuppressant for organ transplantation, inhibits full cycle HCV replication and restores type I interferon (IFN) signaling pathway in human hepatocytes. CsA treatment of hepatocytes before, during, and after HCV infection significantly inhibited full cycle viral replication, which is evidenced by decreased expression of HCV RNA, protein, and infectious viruses in human hepatocytes. The suppression of HCV replication by CsA was associated with elevated levels of endogenous IFN-α in infected hepatocytes. Although CsA had little effect on IFN-α signaling pathway in uninfected hepatocytes, CsA treatment of HCV-infected hepatocytes specifically upregulated the expression of IFN regulatory factor-1 and inhibited the expression of suppressor of cytokine signaling-1 and protein inhibitor of activated signal transducers and activators of transcription-x, the primary negative regulators of IFN signaling pathway. These findings provide additional evidence to support the development of CsA-based prevention/treatment of HCV infection for transplant recipients.

Wnt5a promotes differentiation of human dental papilla cells

AIM

To investigate the role of Wnt5a in the process of differentiation of human dental papilla cells (HDPCs).

METHODOLOGY

Recombinant adenovirus encoding full-length Wnt5a cDNA was constructed to investigate the biological role of Wnt5a on the differentiation of HDPCs. The effect of Wnt5a on HDPCs differentiation was determined by ALP activity assay, ALP staining and mineral induction assay. Mineralization-related gene expressions were assessed by RT-PCR.

RESULTS

Immunostaining revealed Wnt5a expression in the odontoblast layer and dental papilla tissue. Over-expression of Wnt5a by transfecting HDPCs with an Wnt5a-carrying construct increased ALPase activity and the formation of mineralized nodules of HDPCs. RT-PCR analysis showed that the expressions of mineralization-related genes, such as bone sialoprotein, collagen type I, osteonectin, osteopontin (OCN), dentine matrix protein-1 were up-regulated by Wnt5a.

CONCLUSIONS

Wnt5a promoted differentiation of HDPCs.

Properties of hepatitis C virus minigenome containing mutated 5'UTR region and luciferase transgene

Sequences at the 3'UTR of Hepatitis C virus (HCV) negative-strand (-)RNA play an important role in the initiation of positive-strand (+)RNA synthesis. However, the underlying mechanism in cellular context is still unclear. In this report, we designed several cDNA-based HCV-like minigenomes containing different mutations at the 5'UTR of (+)RNA. These (+)RNAs transcribed from the minigenomes in vitro were transfected into HCV replicon cells for producing (-)RNAs with deletions of different stem loops (SL) at the 3'-end. The results showed that expression of the antisense transgene from minigenome increased, when the minigenome containing deletion of SL-C1+D1+E1 at the 3'-end of (-)RNA was transfected into the HCV replicon cells compared to that of the full minigenome. The expression of the transgene from minigenome decreased using other mutant minigenomes containing deletions SL-A1, SL-A1+B1, and SL-A1+B1+C1 at the 3'-end of (-)RNA. Finally, the transgene from SL-C1+D1+E1 of (-)RNA using CMV promoter-driven minigenome was expressed at higher level than full minigenome in HCV replicon cell lines. These results indicated that the region of (-)RNA interacting with HCV replicase may locate in the SL-C1+D1+E1 region of (-)RNA.

KEYWORDS

Hepatitis C virus; minigenome; RNA dependent RNA polymerase; replication.

134. DIFFERENTIATION OF HUMAN EMBRYONIC STEM CELLS TO MULLERIAN TISSUE

The human uterus develops from the distal Mullerian Duct, a derivative of the mesoderm germ layer. Unlike other mammalian species (eg. mouse) the endometrium of the human uterus develops prenatally during gestation. Little is known about the developmental process involved. A better understanding of human endometrial development may shed light on the mechanisms involved in endometrial regeneration and pathogenesis of adult proliferative endometrial diseases. Mouse neonatal uterine mesenchyme (mNUM) is inductive and can maintain the phenotype of normal adult human endometrial epithelial cells [1]. Both adult human endometrial stroma and neonatal mouse endometrial mesenchyme secrete growth factors of the TGF-beta family including BMPs which have been shown to play an important role in differentiation of human embryonic stem cells (HESC) [2, 3]. Hypothesis: mNUM will direct differentiation of HESC to form Mullerian Duct-like epithelium. Aim: to investigate the role of mNUM in differentiating HESC in vitro and in vivo using A tissue recombination technique. Method: Embryoid bodies (EB) were formed from GFP labelled HESC (ENVY) and GFP-MIXL1 HESC reporter line [4, 5] and recombined with 2 × 0.5 mm pieces of day 1 epithelial cell-free mNUM. Recombinant tissues were either harvested for gene expression analysis or grafted under the kidney capsule of NOD/SCID mice. Results: We found by qRT-PCR that mNUM induces HESC to form mesendoderm/mesoderm progenitors in vitro, obligate intermediates of the developing Mullerian Duct. After further incubation in vivo under the guidance of mNUM, HESC differentiated to form duct-like structures comprising mesoepithelial cells that co-expressed several key developmental proteins of the Mullerian Duct including Emx2, Pax2, Hoxa10, CA125, and also intermediate filament markers such as CK8/18, Vimentin (n = 8). Conclusion: Our study demonstrated for the first time that mNUM can direct HESC to form a mesodermally derived epithelium that is Mullerian Duct-like, providing a novel model for studying human uterine development. (1) Kurita T, et al., The activation function-1 domain of estrogen receptor alpha in uterine stromal cells is required for mouse but not human uterine epithelial response to estrogen. Differentiation, 2005. 73(6): 313–22.(2) Hu J, Gray CA, Spencer TE, Gene expression profiling of neonatal mouse uterine development. Biol Reprod, 2004. 70(6): 1870–6.(3) Stoikos CJ, et al., A distinct cohort of the TGFbeta superfamily members expressed in human endometrium regulate decidualization. Hum Reprod, 2008. 23(6): 1447–56.(4) Davis R, et al., Targeting a GFP reporter gene to the MIXL1 locus of human embryonic stem cells identifies human primitive streak-like cells and enables isolation of primitive hematopoietic precursors. Blood, 2008. 111(4): 1876–84.(5) Costa M, et al., The hESC line Envy expresses high levels of GFP in all differentiated progeny. Nat Methods, 2005. 2(4): 259–60.

The Role of Dragon (Repulsive Guidance Molecule-B, RGM-B) in Human Breast Cancer

Introduction: Repulsive guidance molecules (RGMs) are involved in embryonic development and iron homeostasis. RGM-A mediates repulsive axonal guidance and neural tube closure, and RGM-C is mutated in juvenile hemochromatosis. RGM-B, also known as Dragon, is a myelin-derived inhibitor of axon growth in the central nervous system. The RGM family was also identified as co-receptors of bone morphogenetic proteins (BMPs), a group of proteins that are involved in development of bones, the differentiation and progression of cancer. However, the role of RGMs played in breast cancer remains unclear. In the present study, we examined the pattern of expression of the RGM family in human breast cancer cells and investigated the impact of Dragon (RGM-B) on BMP-induced cell function in breast cancer cells.Material and Methods: Conventional RT-PCR was performed to screen the expression of RGMs in human breast cancer samples and a range of breast cancer cell lines. Dragon/RGM-B ribozyme transgenes were generated and in order to knock down the Dragon transcript. Subsequently, MDA-231RGMB-Knock-down variants were created by way of the transgenes. A series of cell function assays were employed to investigate any biological effects upon RGM-B knockdown on the breast cancer cells as well as cell's response to recombinant BMP proteins.Results: RGM-A and RGM-C transcripts were barely detectable in breast cancer cell lines (MDA-MB-231 and MCF-7) and tissues. However RGM-B transcripts were expressed in both cell lines. Using anti-RGM-B transgenes, MDA-231RGMB-Knock-down variant cell lines, in which RGM-B transcripts were knocked down, were created. Compared with wild type and control transfection, MDA-231RGMB-Knock-down variants displayed a significant increase in both the adhesiveness and cells growth (p &lt; 0.05, vs the respective controls, for adheresion and for cell growth). Interestingly, RGM-B knockdown did not have any significant effects on the invasiveness of the cells. Finally, wild type breast cancer cells and the RGMB knock down variant cell lines showed a similar response to the treatment with rhBMP-11, indicating that RGM-B is less critical in BMP-11 mediated cell functions.Conclusion: The present study is the first to examine the role of RGM-B in breast cancer and has demonstrated that knock-down of RGMB could enhance breast cancer cells' ability to grow and attach, indicating that RGM-B may act as an inhibitor in breast cancer. This property is unique to RGMB, as this ability is not associated with any other member in the RGM family.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6158.

BMPR-II Mediates Positive Regulation on In Vitro Cell Growth, the Potential Implications for Breast Cancer

Introduction: Breast cancer is the primary type of female cancer in the UK. We have recently shown that reduced expression of BMPR-IB correlates with poor prognosis, and may be useful as a prognostic indicator in breast cancer (1). This current study aimed to see if a role for the BMP type II receptor (BMPR-II), also exists in the progression of breast cancer.Methods: Expression of BMPR-II was examined in a cohort of 32 normal breast tissue and 112 primary breast tumour tissue samples. Transcript levels of BMPR-II were then determined using quantitative real time-PCR and protein levels were assessed using immunohistochemical (IHC) staining. Finally, ribozyme transgenes were constructed to knock-down BMPR-II expression in MDA-MB-231 cells. The effect this had in vitro cell growth was examined.Results: In normal breast tissue, IHC staining demonstrated strong expression of BMPR-II, specifically in the epithelial cells. In comparison to the normal breast tissue, reduced expression of BMPR-II was evident in the breast tumour samples. BMPR-II transcript levels were further determined using Q-PCR. A trend was evident in that patients with poor prognosis (0.012±0.09) including those with metastasis, local recurrence and breast cancer deaths, demonstrated reduced BMPR-II expression compared to disease free patients (33±13, p=0.09 vs. poor prognosis). Furthermore, lower expression levels were seen in patient samples with a Nottingham Prognosis Index (NPI) greater than 5.4 (poor prognosis group) (18±17) compared to those with NPI &lt;3.4 (good prognosis group) (41±18, p=0.19). Finally, BMPR-II expression was markedly lower in advanced breast cancer of TNM stage 3 and 4 (0±0.1) compared with those of early stage of the disease (TNM1, 46±17, both p&lt;0.01). Despite the clear trend seen, the majority of the data was not found to be significant, suggesting that unlike BMPR-IB, BMPR-II is less useful in predicting prognosis of breast cancer. However, knocking down BMPR-II expression in MDA-MB-231 breast cancer cell line resulted in a reduction of in vitro cell growth, suggesting BMPR-II may play a positive role in breast cancer cell growth. The absorbance of MDA-MB-231BMPR-IIKO cells at day 5 was 1.29±0.09, p&lt;0.01 compared with MDA-MB-231WT (1.90±0.18) and MDA-MB-231GFP control cells (2.30±0.23).Conclusion: This study reveals a trend for BMPR-II in that its expression appears to be reduced in breast cancer patients with poor prognosis. Despite this, it is not as useful of a prognostic indicator as its type I counterpart BMPR-IB, suggesting that in breast cancer progression, BMPR-IB plays a more important role. However, reduced expression of BMPR-II in MDA-MB-231 resulted in a promotion of cell growth, suggesting that BMPs in breast cancer cells may act via BMPR-II to promote tumour growth. However, this needs further investigation.Reference:1. Bokobza SM, et al. Reduced expression of BMPR-IB correlates with poor prognosis and increased proliferation of breast cancer cells. Cancer Genom Proteom, 2009, 6, 101-108

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3039.

Implication of a Pro-Apoptotic Protein, Prostate Apoptosis Response-4 (Par-4) in Breast Cancer

Background: Par-4, Prostate Apoptosis Response-4, is pro-apoptotic in certain cell types and has been implicated in the development and progression of solid tumours. However, the role of Par-4 in breast cancer remains unclear. The current study investigated the role played by Par-4 in breast cancer.Methods: The expression of Par-4 was examined in a breast cancer cohort using quantitative real time PCR and immunohistochemistry (IHC). The biological functions of Par-4 in breast cancer cells were tested by creating breast cancer cell lines that had differential Par-4 expression. The cell functions were examined using a variety of in vitro assays, including growth, migration and invasion. The implication of Par-4 in breast cancer was further tested in an in vivo tumour model.Results: A marked decrease of both Par-4 mRNA and protein was seen in breast tumours compared with background tissues. Par-4 staining was cytoplasmic in both mammary epithelial cells and cancer cells in the tissues. The level of Par-4 transcripts in primary tumours was decreased in the patients with poor prognosis and worse clinical outcome. The overall survival was poor in the patients with lower Par-4 transcript level, p=0.0082 compared with the patients who had higher expression. Patients with higher expression level also had longer disease free survival (133.1 months (95% CI, 121.1-145.1 months)), p=0.0597 compared with patients who had lower expression (118.4 months (95% CI, 103.2-133.5 months)). Over-expression of Par-4 in MDA-MB-231 cells (MDA-MB-231Par4exp) resulted a reduction of cell growth, migration and invasion in vitro. The invaded cell number of MDA-MB-231Par4exp was 17.9±2.5, p&lt;0.01 compared with both MDA-MB-231WT(30.8±2.6) and MDA-MB-231pEF(34.1±6.5) controls. This also led to a decreased in vivo tumour growth, in an athymic mice model.Conclusions: Taken together, decreased Par-4 expression in breast cancer correlates with poor prognosis and shorter survival. Par-4 suppresses growth, migration and invasiveness of breast cancer cells in vitro, and also inhibits in vivo tumour growth. It suggests that Par-4 plays critical roles in the progression of breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6155.

Cellular Location and Expression Pattern of NHERF1 in Human Breast Cancer and the Impact of NHERF1 on the Growth of Breast Cancer Cells

BACKGROUND: The Na+/H+ exchange regulatory factor 1 (NHERF1) is an adapter protein that, when present in the cytoplasmic region, regulates trafficking and signaling of several G protein-coupled receptors (GPCRs). However, it has been recently suggested that, when located in the nucleus of cells, NHERF1 may have an oncogenic role in cancer. Recent work has shown that NHERF1 may be involved in the progression of certain solid tumours including breast cancer. The aim of the current study were: first to evaluate the spatial and cellular location of the NHEREF1 protein in mammary tissues, mammary epithelial and cancer cells, second to determine the expression pattern of the NHERF1 transcript in human breast cancer and deduce a possible association with clinical and pathological factors and, finally, to investigate the cellular impact of NHERF1 expression on breast cancer cells.MATERIALS AND METHODS: Expression of NHERF1 was examined in a cohort of breast tissue samples. The protein levels and distributions were assessed using immunohistochemical staining (IHC) and imaging analysis tools. The distribution of the NHERF1 protein in nucleus and cytoplasm was calculated using the protein staining intensity ratio between the two compartments. The transcript level was determined using quantitative real time-PCR. Constructed ribozyme transgenes were used to knock-down NHERF1 in MCF-7 cells, and the effect this had on in vitro cell growth was examined using in vitro methods.RESULTS: NHERF1 protein staining was seen in both normal epithelial cells and cancer cells in tissues. However, the staining pattern in cancer cells and normal epithelial cells was different. The protein was seen at a higher level in the nucleaus of cancer cells, as shown by a higher nuclear/cytoplasmic ratio of NHERF1 staining in breast cancer cells when compared with that in normal mammary epithelial cells (p=0.038). NHERF1 expression was increased in high grade tumours compared with low grade tumours (p=0.0016, grade-3 vs grade-1). Quantitative analysis of the NHERF1 transcript revealed a higher level expression in samples from patients with poor prognosis and that this was linked to the long term survival: mean survival for patients with high NHERF1 was 102 (55-148.8, 95%CI) months compared with 136 (126.6-145.9) months for patients with low NHERF1 transcripts. Using human breast cancer cell line, MCF7, we created NHERF1 knockdown subline. Loss of NHERF1 in the MCF-7 subline resulted in an increase in the growth rate, in vitro.CONCLUSION: This study shows that NHERF1 influences the growth of breast cancer cells. However, the effect of NHERF1 is dependent upon the levels of expression of NHERF1 in breast cancer tissues and most importantly determined by the cellular location of this protein in cancer cells.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3155.

Aberrant Expression of ARP2/3 in Breast Cancer and the Association with Disease Progression

Background: Increased motility is an important characteristics of neoplastic cells, a cell function mediated through actin polymerization. During this process, aside from creation of new branches and lengthening of pre-existing actin molecule, Actin-Related Proteins (ARP)- 2 and ARP-3 work as a complex promotes polymerization through production of new nuclei for actin polymerization. This regulation is orchestrated by other intracellular regulators including and WAVE and WASP proteins, which have been shown to be aberrant in breast cancer (1,2). In this study we determined the differential expression of ARP-2 and ARP-3 and correlated the expression with various prognostic factors.Methods: Expression of ARP-2 and ARP-3 was examined in a cohort of mammary tissues (n=33 normal breast tissue and n=127 primary breast tumor tissue samples). Transcript levels of ARP2 and ARP3 were then determined using quantitative real time PCR (Q-PCR) and protein levels were assessed using immunohistochemical (IHC) staining. Results were analyzed by Mann-Whitney U test.Results: Cytoplasmic staining for both ARP-2 and ARP-3 was noted along with strong epithelial staining as compared to stromal cells. Quantitative real time PCR (Q-PCR) data analysis showed lower expression of both ARP -2 & -3 in tumour tissue as compared to normal but without statistical significance. ARP-2 expression was significantly reduced in tumour samples from patients with poor prognosis (p=0.037) and patients who died of breast cancer (p=0.0265). Primary breast tumor tissue samples from patients classified as TNM stage 3 and 4 showed statistically significant lower expression of ARP-3 as compared to normal tissue (p= 0.019 and 0.020, respectively). ARP-3 expression was also significantly lower in patients who developed local recurrence of breast cancer (p=0.027). Using a Spearman correlation analysis, ARP-3 transcripts were find to be significantly correlated with the WAVE-2 transcript (r=0.42, p&lt;0.01).Conclusions: Breast cancer shows aberrant expression of ARP-2 and ARP-3, a pattern linked to the prognosis of the patients. ARP-3 and WAVE-2 may have an intimate interplay in this association which warrants further investigation.References1. Fernando HS et al. Expression of the WASP verprolin-homologues (WAVE members) in human breast cancer. Oncology. 2007;73:376-3832. Martin TA, et al. N-WASP is a putative tumour suppressor in breast cancer cells, in vitro and in vivo, and is associated with clinical outcome in patients with breast cancer. Clin Exp Metastasis. 2008;25:97-108

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6169.

Skeletal myoblast transplantation for attenuation of hyperglycaemia, hyperinsulinaemia and glucose intolerance in a mouse model of type 2 diabetes mellitus

AIMS/HYPOTHESIS

We aimed to demonstrate the feasibility and efficacy of intra-muscular transplantation of human skeletal myoblasts (hSkMs) for attenuation of hyperglycaemia and improvement of insulin sensitivity using a mouse model of type 2 diabetes mellitus.

METHODS

KK Cg-Ay/J mice, aged 12 to 14 weeks, underwent an initial intraperitoneal glucose tolerance test (GTT) and were divided into the following groups: KK control group, basal medium (M199) only; KK myoblast group, with hSkM transplantation; KK fibroblast group, with human fibroblast transplantation. Non-diabetic C57BL mice were used as an additional normal control and also had hSkM transplantation. Cells were transplanted intra-muscularly into the skeletal muscles of the mice. All animals were treated with ciclosporin for 6 weeks only. HbA(1c) and fasting GTT, as well as serum adiponectin, cholesterol, insulin and triacylglycerol were studied.

RESULTS

Immunohistochemistry studies showed extensive survival of the transplanted hSkMs in the skeletal muscles at 12 weeks, with nuclei of the hSkMs integrated into the host muscle fibres. Repeat GTT showed a significant decrease in glucose concentrations in the KK myoblast group compared with the KK control and KK fibroblast groups. The KK myoblast group also had reduced mean HbA(1c), cholesterol, insulin and triacylglycerol, and increased adiponectin compared with the KK control and KK fibroblast groups. C57BL mice showed no change in glucose homeostasis after hSkM transplant.

CONCLUSIONS/INTERPRETATION

Human skeletal myoblast transplantation attenuated hyperglycaemia and hyperinsulinaemia and improved glucose tolerance in the KK mouse. This novel approach of improving muscle insulin resistance may be a potential alternative treatment for type 2 diabetes mellitus.

Beyond RET: potential therapeutic approaches for advanced and metastatic medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) is a rare calcitonin-producing neuroendocrine tumour that originates from the parafollicular C-cells of the thyroid gland. The RET proto-oncogene encodes the RET receptor tyrosine kinase, which has essential roles in cell survival, differentiation and proliferation. Activating mutations of RET are associated with the pathogenesis of MTC and have been demonstrated in nearly all hereditary and in 30-50% of sporadic MTC cases, making this receptor an excellent target for small-molecule inhibitors for this tumour. Clinical trials of small organic inhibitors of tyrosine kinase receptors (TKIs) targeting the RET receptor have shown efficacy for treatment of metastatic MTC with 30-50% of patients responding to these agents. Despite the importance of the RET receptor in MTC, it is clear that other signal transduction pathways, tyrosine kinase receptors, and tumour suppressor genes are involved in MTC tumourigenesis and progression. A better understanding of molecular cross-talk between these signal pathways and the RET receptor may lead to combinatorial therapy that will improve outcomes beyond what is currently possible with RET-directed TKIs. Finally, there is evidence that immunological-based therapy using dendritic cell vaccination strategies have been effective for reducing tumour mass in a small number of patients. The identification of additional MTC-specific tumour antigens and a better understanding of specific epitopes in these tumour antigens may lead to improvement of response rates.