O18 Activated leukocyte cell adhesion molecule (ALCAM) and its intracellular linkers in assessing the outcome of patients with breast cancer

Introduction

ALCAM (also known as CD166) is a membrane integral protein and said to have a role in predicting the clinical outcome of patients with breast cancer, but the pattern of the prediction value is inconsistent. ALCAM confers cell-cell adhesion via heterotypic and homotypic interactions and linked to cytoskeleton via the ERM protein family (Ezrin, Moesin, Radixin and EHM2), particularly ezrin. The present study explored if the ALCAM and its ERM linkers may assist in refining the prognostic value of ALCAM.

Method

Gene transcripts of ACLAM and the ERM family members were quantitatively analysed in an existing breast cancer cohort collected freshly after surgery. The relationship between ALCAM and patient’s survival (follow-up 10 years) were stratified by the ALCAM linkers. Statistical methods were Kaplan-Meier’s survival method, ROC and logistic regression.

Result

ALCAM significantly correlated with four ERM family members (P < 0.005). Patients with high levels of ALCAM transcripts had significantly long overall survival. Further stratification by the epithelial rich Ezrin and endothelial rich Moesin identified subgroup of patients with good prognosis. Multivariant analysis indicates that the combined power of ALCAM and ERM family serves as an independent prognostic factor (P = 0.003) together with the other two factors, namely the Nottingham Prognostic Index and Nodal status (P = 0.02). A similar prediction power for disease free survival was seen with ALCAM and ERM combination.

Conclusion

ALCAM and its intracellular cytoskeletal linker molecules, the ERM family, together forms a significant prognostic factor to the clinical outcome of patients with breast cancer.

Take-home Message

ALCAM stratified by the ERM family have prognostic value in breast cancer

Development and validation of a gene expression test to identify hard-to-heal chronic venous leg ulcers

Background

Chronic venous leg ulcers pose a significant burden to healthcare systems, and predicting wound healing is challenging. The aim of this study was to develop a genetic test to evaluate the propensity of a chronic ulcer to heal.

Methods

Sequential refinement and testing of a gene expression signature was conducted using three distinct cohorts of human wound tissue. The expression of candidate genes was screened using a cohort of acute and chronic wound tissue and normal skin with quantitative transcript analysis. Genes showing significant expression differences were combined and examined, using receiver operating characteristic (ROC) curve analysis, in a controlled prospective study of patients with venous leg ulcers. A refined gene signature was evaluated using a prospective, blinded study of consecutive patients with venous ulcers.

Results

The initial gene signature, comprising 25 genes, could identify the outcome (healing versus non-healing) of chronic venous leg ulcers (area under the curve (AUC) 0·84, 95 per cent c.i. 0·73 to 0·94). Subsequent refinement resulted in a final 14-gene signature (WD14), which performed equally well (AUC 0·88, 0·80 to 0·97). When examined in a prospective blinded study, the WD14 signature could also identify wounds likely to demonstrate signs of healing (AUC 0·73, 0·62 to 0·84).

Conclusion

A gene signature can identify people with chronic venous leg ulcers that are unlikely to heal.

Abstract P6-09-07: Expression of miR-106b in circulating tumor cells is associated with EMT and prognosis in metastatic breast cancer patients

# Co-first author: W.T., G.L., X.X.

* Co-Correspondence: C.G. and W.G.J.

Abstract

Background: Circulating tumor cells (CTCs) display changes in epithelial-mesenchymal transition (EMT) markers and miRNAs regulate EMT in breast cancer cells. The association between EMT characteristics and miRNA expression in CTCs of metastatic breast cancer (MBC) patients and their clinical implications remain unknown.

Methods: CTC-specific miRNAs were screened based on comparison of the miRNA profile between CTC and primary tumor. RT-PCR was used to quantity the expression levels of EMT makers and miRNA candidates. We enrolled 219 MBC patients with CTCs ≥ 5/7.5mL blood from 2 cohorts and CTCs were detected and enriched by CellSearch. Overall survival (OS) and radiological response were analyzed. CTCs were divided into epithelial- (E-CTCs) and mesenchymal-like CTC (M-CTCs) phenotypes based on a cut-off value derived from suspended breast cancer cells recovered from PBMCs.

Results: MiR-106b displayed upregulation in CTCs, with a higher level in M-CTCs than E-CTCs. Patients with E-CTCs showed better OS than those with M-CTCs (HR 1.77, 95% CI 1.14-2.78, P =0.012). CTCs from chemo-resistant MBC patients exhibited higher miR-106b. CTC-specific miR-106b was negatively associated with therapy response and OS (HR 1.73, 95% CI 1.06-2.84, P = 0.029).

Conclusions: CTC-specific miR-106b was associated with EMT phenotypes of CTCs and may predict prognosis in MBC patients.

Citation Format: Tan W, Liang G, Xie X, Tan L, Sanders AJ, Liu Z, Ling Y, Zhong W, Jiang WG, Gong C. Expression of miR-106b in circulating tumor cells is associated with EMT and prognosis in metastatic breast cancer patients [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-09-07.

Abstract P4-05-03: Heat shock protein 27 (HSP27) and HER2 positively correlate in breast cancer and effect cell responsiveness to neratinib and cMET inhibitor

Background: Upregulation of heat shock protein-27 (HSP27), a key member of the HSP family, has been shown to confer resistance to chemotherapy and radiotherapy in solid tumours including breast cancer. Evidence is also emerging that HSP27 is linked to the metastatic spread of breast cancer and key cellular traits including cellular migration. Neratinib is an orally available tyrosine kinase inhibitor that irreversibly binds and inhibits EGFR, HER2 and HER4 receptor tyrosine kinases. cMET, the receptor for hepatocyte growth factor and target for cancer therapies, has been shown to be trans-phosphorylated by EGFR. In the current study, we evaluated HSP27 expression within a breast cancer cohort and its implications in cellular responsiveness to cMET inhibition and neratinib.

Methods: HSP27 transcript expression was analysed in our chemotherapy naïve breast cancer cohort (n=124) using quantitative PCR (qPCR) and compared to clinic-pathological information including long-term survival over a ten year follow up period. In addition, the correlation between HSP27 and HER2 expression was explored using Spearman Rank order. High-throughput cell migration analysis was performed using ECIS, on MCF-7 control and HSP27 siRNA knockdown cells in conjunction with neratinib and PHA 665752, a small molecule cMET inhibitor.

Results: In our primary breast cancer cohort, there were no significant associations between HSP27 transcript expression levels and tumour grade, TNM or estrogen receptor (ER) status. Combined survival expression analysis indicated that the worst patient prognosis was associated with high levels of both HER2 and HSP27 and high HER2 and low HSP27 whereas best patient prognosis was associated with low HER2 and low HSP27 expression. Knockdown of HSP27 in MCF7 cells brought about a reduction in cellular migration compared to the control. Additionally, this reduction was enhanced by the addition of neratinib, in a concentration dependent manner, and also cMET inhibition when individually treated. Furthermore, the greatest inhibitory effects on MCF-7 migration were seen following HSP27 knockdown and combined treatment with neratinib and PHA 665752.

Conclusions: Our current data suggests that HSP27 confers low sensitivity to drugs such as neratinib and PHA 665752, particularly in relation to cellular migration and hence potentially metastasis. Therefore, the targeting of HSP27, HER2 and cMET appear to act syngeristically to regulate cellular migration in vitro. Furthermore, clinically expression of HER2 and HSP27 may serve as a prognostic marker for breast cancer survival. Hence, combination therapies that target both HSP and HER2 pathways may provide new clinical opportunities for preventing breast cancer progression.

Citation Format: Owen S, Sanders AJ, Ruge F, Lalani AS, Avogadri-Connors F, Bryce RP, Jiang WG. Heat shock protein 27 (HSP27) and HER2 positively correlate in breast cancer and effect cell responsiveness to neratinib and cMET inhibitor [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-05-03.

Abstract P3-15-04: Signalling pathways targeted by the YangZheng Xiaoji extract and the therapeutic implications in human breast cancer

Background. Yangzheng Xiaoji is a formulation of Chinese medicine and has been used in the treatment of solid cancer as an adjuvant to chemotherapy by reducing the side effects to the patient. There has been evidence to show that the medicine has a direct biological role in cancer cells. In the present study, we sought to investigate the potential effects of the medicine on breast cancer cells and in particular aimed to identify the key targets and molecular pathways contributing to the anti-cancer effect of the medicine.

Methods. Human breast cancer cell lines (BT549, BT20, MDA MB-231, MCF-7 and ZR 75-1) with varying invasiveness and receptor status were used. The soluble extract of Yangzheng Xiaoji, namely DME25 was used in the study. The effects of DME25 on the growth, toxicity and cellular migration were assessed. Signalling kinase changes were screened using kinase antibody array based array technologies. Kinases were also validated using phosphorylation based protein blotting.

Results. Of the five breast cancer cell lines tested, Yangzheng Xiaoji extract DME25 showed little cytotoxicity over a broad range of concentrations. However, DME25 were able to markedly reduce the migration of the panel of breast cancer tested, without being toxic. Triple negative cells responded in a similar fashion with other cells. It was also noted that the adhesion of these cells were also inhibited by DME25. Using a protein kinase array, it was shown that a number of kinase complexes were inhibited by the medicine, notable ones including EGFR family kinases (reduced by 35%), Janus protein kinases (JAK) (by 57%), and Ras-related C3 botulinum toxin substrate (Rac1 or CDC42 GTPase) (by 49%) and Ribosomal protein S6 kinases (RSKs) (by 52%). Given the clinical significance of RSKs in human breast cancer, we further evaluated the role of RSK and RSK inhibitors in DME mediated cell functions and have demonstrated that both in triple negative breast cancer cells and receptor positive breast cancer cell lines, DME25 was able to synergistically enhance the effect of RSK2 inhibitor, SL1010-1, on the both the cellular migration and cell growth.

Conclusion. Yangzheng Xiaoji has a broad and direct effect on the migration of breast cancer, an effect unrelated to hormone receptor status and independent of cytotoxicity. The medicine appears to target kinase pathway, particularly for the RSK kinases, suggesting an important clinical implication in the treatment of breast cancer.

Citation Format: Jiang WG, Ye L, Owen S, Ruge F, Martin TA, Sanders AJ, Gao G, Wei C, Wu Y, Davies E. Signalling pathways targeted by the YangZheng Xiaoji extract and the therapeutic implications in human breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-15-04.

Abstract P1-07-27: Prognostic value of programmed death 1/Programmed death ligand 1/ mammalian target of rapamycin/Rictor/Tuberin in human breast cancer

Background:The Mammalian Target of Rapamycin (mTOR) regulates a multitude of cellular processes including metabolism, proliferation and growth. It is known to form two multi-protein complexes - complex 1 (mTORC1) and complex 2 (mTORC2) with Raptor and Rictor being their core proteins vital for their integrity.

Tuberin, the product of the Tuberous Sclerosis Complex gene 2, TSC2, has been characterized as a tumour suppressor and negatively regulates the mTOR pathway.

Programmed Death 1 (PD-1), a transmembrane protein particularly expressed on the surface of tumour cells, acts as an immune checkpoint receptor. Together with its ligand Programmed Death Ligand 1 (PDL-1) they form a pathway which when activated influences anti-tumour immunity and supresses anti-tumour adaptive responses. The expression of PD1/PDL-1 is lightly regulated by the mTOR pathway.

We investigated the value of expression patterns of all these molecules in breast cancer as potential prognostic factors.

Materials and Methods: Quantitative PCR (qPCR) analysis was used to determine the transcript expression profile of the five genes of interest (PD-1, PDL-1, mTOR, Rictor and Tuberin) in 128 breast cancer specimens.The correlation between PD-1 or PDL-1 with mTOR, Rictor and Tuberin was assessed using the Spearman Rank Order Correlation. Subsequently, a combined analysis was performed, where the influence of favourable expression in relation to patient overall (OS) and disease free survival (DFS) using the Kaplan Meier survival curves and multivariate analysis.

Results: The mRNA expression of the molecules showed a varying degree of association with the clinicopathological parameters. PD-1 transcript expression showed a significant correlation with mTOR expression (p < 0.001). PDL-1 transcript expression was seen to correlate with mTOR (p < 0.001), Rictor (p < 0.001) and Tuberin (p < 0.01) transcript expression. However, when the expression profile was analysed using an integrated expression score, the combined predictive value for the clinical outcome of the five genes was highly significant in terms of OS (p < 0.001) and DFS (p = 0.001), and was found to be an independent prognostic factor (p<0.001) for breast cancer related death using a multivariate analysis.

Conclusions: Our study identifies a molecular signature of 5 genes as a powerful prognostic predictor of OS and DFS in patients with breast cancer.

Citation Format: Uhercik M, Sanders AJ, Owen S, Davies EL, Sharma AK, Jiang WG, Mokbel K. Prognostic value of programmed death 1/Programmed death ligand 1/ mammalian target of rapamycin/Rictor/Tuberin in human breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-07-27.

The clinical significance and impact of interleukin 15 on keratinocyte cell growth and migration

Chronic wounds represent a significant burden to health services and are associated with patient morbidity. Novel methods to diagnose and/or treat problematic wounds are needed. Interleukin (IL)-15 is a cytokine involved in a number of biological processes and disease states such as inflammation, healing and cancer progression. The current study explores the expression profile of IL-15 and IL-15 receptor α (IL-15Rα) in chronic wounds and its impact on keratinocytes. IL-15 and IL-15Rα expression were examined in healing and non-healing chronic wounds using qPCR and immunohistochemical analysis. The impact of recombinant IL-15 (rhIL-15) on human adult low calcium temperature (HaCaT) keratinocyte growth and migratory potential was further examined. IL-15 transcript expression was slightly, though non-significantly elevated in healing chronic wounds compared with non-healing chronic wounds. IL-15 protein staining was minimal in both subtypes of chronic wounds. By contrast, IL-15Rα transcript and protein expression were both observed to be enhanced in non-healing chronic wounds compared with healing chronic wounds. The treatment of HaCaT cells with rhIL-15 generally enhanced cell growth and promoted migration. Analysis with small molecule inhibitors suggested that the pro-migratory effect of rhIL-15 may be associated with ERK, AKT, PLCγ and FAK signalling. IL-15 may promote healing traits in keratinocytes and the differential expression of IL-15Rα is observed in chronic wounds. Together, this may imply a complex role for this interleukin in wound healing.

Abstract P6-02-02: mRNA expression of death associated protein 3 (DAP3) and human breast cancer: Clinical correlations and in vitro evidence

BACKGROUND: To our knowledge, this study is the first to focus on the potential role for death-associated protein 3 (DAP3) in human breast cancer.

MATERIAL AND METHODS: mRNA expression of DAP3 in breast cancer tissues (n = 127) and normal background tissues (n = 33) were determined using quantitative polymerase chain reaction (qPCR) and were correlated with clinico-pathological data accumulated over a 10-year follow-up period.

Furthermore the effects of DAP3 knock down in breast cancer cell lines (MCF-7 and MDA-MB-231) were investigated. The cells were subjected to conventional growth, adhesion and invasion assays.

In addition to the above, electric cell-substrate impedance sensing (ECIS) assay and annexin V/propidium iodide binding apoptosis assay were performed. For the apoptosis assay, the cells were subjected to 48 to 72 hours of serum hunger (depending on cell line) before being analyzed using a flow cytometer.

RESULTS: The expression of DAP3 mRNA was demonstrated to decrease with increasing Nottingham Prognostic Index (NPI2 vs. NPI3, p = 0.036), TNM stage (TNM1 vs. 3, p = 0.07), and tumour grade (grade 1 vs. 3, p = 0.08). Lower DAP3 expression levels were significantly associated with local recurrence (p = 0.013), distant metastasis (p = 0.0057) and mortality (p = 0.019).

Kaplan-Meier plot analysis suggests that patient with higher levels of DAP3 expression had better overall survival compared to patients with lower levels of DAP3 expression (p = 0.075).

DAP3 knock down strains in both cell lines demonstrated increased growth and migration compared to controls during ECIS.

In addition, DAP3 knock down strains of MCF-7 appeared more resistant to serum hunger when compared to controls during the apoptosis assay.

CONCLUSIONS: This study demonstrates an inverse association between DAP3 mRNA levels and tumour stage and clinical stage in breast cancer. This is in keeping with the role of DAP3 as a pro-apoptotic protein. The in vitro evidence lends further credence to this hypothesis. The role of DAP3 may require further investigation to better understand the role of apoptosis in breast carcinogenesis, and may potentially serve as a prognostic marker for human breast cancer.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-02-02.

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.

P4-09-20: Expression Profile of Interleukin 17B and the Receptor IL-17BR in Clinical Breast Cancer

Introduction:

Interleukin 17B (IL-17B) is a member of the interleukin 17 cytokine family. Members of this family have been implicated in conditions such as autoimmune diseases and the inflammatory response. A number of studies have examined the role of IL17A in cancer progression and angiogenesis and shown a variety of functions, both pro- and anti- tumorigenic. Currently there is little data on IL-17B and the receptor IL-17BR and their involvement in cancer progression. The current study looks at the expression profile of IL-17B and IL-17BR in a clinical breast cancer cohort.

Methods:

The expression profile of IL-17B and IL-17BR was examined in a cohort of human normal breast and breast cancer specimens (normal, n = 34; tumour, n = 109). IL-17B and IL-17BR transcript expression in the samples was analysed using Q-PCR and compared to clinical and pathological data.

Results:

Both IL-17B and IL-17BR expression seemed to correlate with NPI staging. IL-17B levels were low in patients with NPI-1 or -2 cancers (median values 3.1 and 1.1 respectively), with highest levels of IL-17B being observed in the poorer prognosis NPI-3 group (median value 206.9; p = 0.07 NPI-1 vs NPI-3 and p = 0.01 NPI-3 vs NPI-2). Similar to this IL17B levels in TNM stage 1 cancers were significantly lower than those in higher TNM stages (TNM1 median value = 0.3 vs grouped TNM234 median value 10.3, p = 0.03). IL-17BR expression also tended to increase with NPI staging (IL-17BR median expression, NPI-1 = 0.0, NPI-2 = 0.04 and NPI-3 = 1.59; NPI-1 vs NPI-3 p = 0.07). Additionally, levels of IL-17BR were found to be significantly lower in background tissue compared to cancer tissue (median values 0.00 vs 0.01 respectively, p = 0.014).

Conclusion:

IL-17BR expression seems to be higher in tumour tissue compared to normal background tissue. Additionally, expression of IL-17B and IL-17BR both appear to be associated with higher NPI stage, particularly in the poor prognostic NPI-3 group. Expression of IL-17B seems to be elevated collectively in TNM stage 2, 3 and 4 compared to the better prognostic TNM1 stage. Together the data suggests that IL-17B and IL-17BR expression may be useful molecules to identify poorer prognostic breast cancers in patients.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-09-20.

P4-09-24: Correlation of Aurora Family Member Expression with Clinical Breast Cancer Prognosis

Introduction:

Aurora-A, Aurora-B and Aurora-C are a family of protein kinases which have been identified as key regulators of the mitotic cell division process. Members of this group have been linked with pro-tumorigenic effects and have been reported as being up-regulated in certain cancers. Our current study examines the expression profile of the Aurora-A, Aurora-B and Aurora-C members in a breast cancer cohort in relation to a number of predictive factors.

Materials and Methods:

The expression of Aurora-A, Aurora-B and Aurora-C was examined in a breast cancer cohort using quantitative real time PCR (normal samples n = 34, tumour samples n = 109) and immunhistochemistry (IHC). Expression of the aurora members was related to clinical parameters such as staging and Nottingham prognostic index (NPI).

Results:

Examination of Aurora-A levels in the breast cancer cohort revealed an association of Aurora-A expression with NPI grouping. High levels of Aurora-A levels were seen in NPI-1 and NPI-2 stages (NPI-1 median = 66.0, NPI-2 median = 64.3), with expression reducing significantly at the higher NPI-3 group (NPI-3 median = 20.3; p = 0.029 vs NPI-2 and p = 0.009 vs NPI-1 respectively). Additionally, Aurora-A levels were found to be significantly lower in grade 3 cancers compared to grade 1 (median grade 1 = 86.5 vs median grade 3 levels = 52.6, p = 0.04). In contrast to this, examination of Aurora-C levels in the cohort identified a relatively low level of Aurora-C in NPI-1 and NPI-2 group (median values NPI-1 = 88, NPI-2 = 34.4) compared to a substantial increase in Aurora-C expression in NPI-3 (median value = 1602, p = 0.05 vs NPI-1 and p = 0.06 vs NPI-2). Aurora-B expression levels did not exhibit any significant differences within the breast cancer cohort.

Conclusions:

Differential expression of Aurora-A, Aurora-B and Aurora-C were observed within the breast cancer cohort. Higher Aurora-A expression was associated with low NPI groups and grades and potentially with better patient prognosis whereas lower levels were seen in the poorer prognostic NPI-3 group and higher grades. An opposite trend was seen in Aurora-C where lower levels were associated with the NPI-1 and NPI-2 groups and significantly higher levels were seen in the NPI-3 group. Aurora-B levels appeared to have no predictive function. This data suggests that together Aurora-A and Aurora-C levels, within a patient may be useful for predicting patient outcome.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-09-24.

P4-09-14: Differential Expression of the Akt1 Isoform in Mammary Ductal Carcinoma

Introduction:

AKT1 is an oncogenic protein and controls numerous cellular processes in both normal and cancerous cells. There are three isoforms, Akt1 (PKBα), Akt2 (PKBβ) and Akt3 (PKBγ). Frequently, regulation of the Akt pathway is disrupted in cancerous cells and interest within the scientific community has focused on the use of this pathway in treating cancer. However, recent studies have also implicated that Akt1 may act to limit invasive migration of breast cancer cells suggesting the potential of this isoform to have both pro- and anti- tumorigenic roles. In the current study we examined the expression profile of Akt1 in a cohort of ducal carcinoma of the breast. Methods:

Quantitative transcript analysis was used to assess the expression levels of Akt1 in a range of ductal carcinoma of the breast (n=85) and normal samples. Expression levels were used in conjunction with clinical and pathological data, as well as the clinical outcomes of the patients (median follow-up 120 months).

Results:

Expression of Akt1 levels in the mammary ductal carcinoma cohort demonstrated a lower level of transcript expression in the lower grade and stage cancers. Levels of Akt1 were found to be significantly lower in grade 1 ductal breast carcinomas compared to the combined higher grade 1 and 2 carcinomas (ductal carcinoma grade 1 median = 3.7 vs ductal carcinoma grade 2,3 median = 33.6, p = 0.01). In addition to this, median transcript levels of Akt1 were found to increase with increasing TNM stage of the ductal carcinoma (Median values of Akt1 in ductal carcinoma TNM 1 = 5.9, TNM 2 = 63.6, TNM 3 = 533 and TNM 4 = 13680). This enhanced expression of Akt1 in higher TNM stages, compared to TNM stage 1, was found to be significant in most cases (TNM1 vs TNM2, p = 0.03; TNM1 vs TNM3, p = 0.15; TNM1 vs TNM4, p = 0.03).

Conclusion:

Variable expression of Akt1 was seen throughout the mammary ductal carcinoma cohort and correlated with a number of prognostic factors. Akt1 transcript levels were found to be significantly reduced in the low grade 1 and TNM1 stages when compared to the higher grades and TNM stages. Our current data suggests that low levels of Akt1 may be associated with better clinical patient prognosis in mammary ductal carcinoma.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-09-14.

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 < 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.

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 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 < 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 < 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.

Abstract P1-02-04: The Influence of Matriptase-2 on Angiogenesis and Tumour Growth In Vivo

Background: Metastasis is a key part of cancer progression and angiogenesis plays a large role in the ability of cancer cells to spread around the body and in the progressive growth of the primary tumour. Matriptase-2 is a cell surface serine protease believed to have implications in cancer metastasis. The current study aims to assess the importance of matriptase-2 in angiogenesis and tumour growth, using in vitro and in vivo models. Methods: Matriptase-2 was over-expressed in the HECV endothelial cell line, previously displaying minimal matriptase-2 expression, through the transfection of a mammalian expression construct containing the full coding sequence for matriptase-2. Following verification of forced expression, the cellular effects of matriptase-2 were examined using a number of in vitro cell models. The effect of matriptase-2 over-expression was also examined in in vivo mouse models by co-delivery of endothelial cells and tumour cells.

Results: Matriptase-2 significantly reduced the motility (46.47±16.18 vs 10.93±2.80 p=<0.01) of the HECV cells and their ability to form tubule structures (23841.60±744.75 vs 9817.80±933.85 p=0.01) in an in vitro angiogenesis Matrigel tubule formation model. Matriptase-2 was found to have no significant effect on the growth (691.52±100.17 vs 763.50±91.43 p=0.110) and cell-matrix adhesion of the HECV cells (64.20±8.70 vs 57.42±4.50 p=0.530). However, the in vivo studies showed a reduction in tumour growth and development following co-injection of cancer cells with endothelial cells over-expressing matriptase-2 compared to co-injection with control endothelial cells. The sizes of tumours in two tumour models were: 70.99±19.52mm3 for tumour cells with control endothelial cells vs 0.17±0.10 mm3 for tumours with Matriptase-2 over-expression endothelial cells, p=<0.01; and 80.41±18.31 mm3 vs 43.12±20.33 mm3 p=0.08, in the other tumour model.

Conclusion: Matriptase-2 appears to negatively influence angiogenesis through its inhibitory effect on endothelial cell motility and tubule formation. This is corroborated by the reduction of tumour growth, in vivo. Together this data suggests that matriptase-2 has an important role in the control of angiogenesis and tumour development.

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

Applicability of an image analysis system in alveolar bone loss measurement

Clinical and epidemiological studies in the field of periodontics and endodontics often utilize radiographs to monitor or measure the changes in bone structure and density. Periodontal bone loss or gain can be quantified on a radiograph by measurement of the distance between the bottom of the bony pocket and the apical contour of the involved tooth. The objective of this investigation was to study the accuracy of an image analysis system (IAS) to measure changes in height of the interproximal crest on radiographs. Artificial bone lesions were introduced in a dissectioned part of a human mandible. The distances between crest and apices were measured with a micrometer (MM). Radiographs were produced with horizontal and vertical deviations of 10 degrees. The radiographs were digitized and processed by computer. The landmarks in the digital image were enhanced mathematically and by histogram-based thresholding. The depth of the introduced defect was increased 6 times, followed by the measurement procedure. The IAS produced measurements of crown-apex distances with an accuracy of 0.066 to 0.358 mm. Repeated crest height measurements were recorded with an accuracy of 0.112 to 0.184 mm. Both the histogram-based binarization and the ellipse-fitting type of contour detection could be applied precisely. Misangulation errors during radiographic exposure of 10 horizontal or vertical did not statistically significant influence the IAS-measurements. The IAS can be applied in clinical trials and follow-up studies.

A computer-aided image analysis system for area measurement of tooth root surfaces

The characteristics of a computer-aided Image Analysis System (IAS) to conduct linear and area measurements on tooth root surfaces were investigated. The borders of the features to be measured were extracted from a digitized video image by histogram-based thresholding and binarization. The lengths and square areas were expressed in the number of pixels. The reference-length and area of one pixel were obtained through measurement of the diameter of a metal ball of known diameter in the same digital image. The validity of the IAS was tested using radiographs of teeth containing round metal restorations of known diameter and area. The accuracy of the length measurements ranged from -2.0 to 2.1%, whereas the accuracy of area measurement was between -5.3 and 0.8%. The precision of the IAS to identify the borders of a tooth root surface and to reproducibly calculate its area, expressed in a coefficient of variation, ranges from 0.49 to 4.11%. The results indicate that imaging techniques can be applied to obtain very accurate measurements of tooth root surfaces.