Showing papers by "Naoto T. Ueno published in 2013"

Bone Metastasis of Breast Cancer.

Abstract: Bone is the most common site of metastasis for breast cancer. Bone metastasis significantly affects both quality of life and survival of the breast cancer patient. Clinically, complications secondary to bone metastasis include pain, pathologic fractures, spinal cord compression, and hypercalcemia of malignancy. Because bone metastasis is extremely common in patients with metastatic breast cancer, clinical management of bone metastases is an important and challenging aspect of treatment in the metastatic setting. The skeleton is a metabolically active organ system that undergoes continuous remodeling throughout life. A delicate balance of the bone-forming osteoblasts and bone-resorbing osteoclasts in the dynamic microenvironment of the skeleton maintains normal bone remodeling and integrity. The presence of metastatic lesions in bone disrupts the normal bone microenvironment and upsets the fine balance between the key components. The changes in the bone microenvironment then create a vicious cycle that further promotes bone destruction and tumor progression. Various therapeutic options are available for bone metastases of breast cancer, and treatment can be tailored for each patient and, often requires multiple therapeutic interventions. Commonly used modalities include local therapies such as surgery, radiation therapy and radiofrequency ablation (RFA) together with systemic therapies such as endocrine therapy, chemotherapy, monoclonal antibody-based therapy, bone-enhancing therapy and radioisotope therapy. Despite the use of various therapeutic modalities, bone metastases eventually become resistant to therapy, and disease progresses. In this chapter, we describe the clinical picture and biological mechanism of bone metastases in breast cancer. We also discuss known risk factors as well as detection and assessment of bone metastases. We present therapeutic options for bone metastasis using a multidisciplinary approach. Further, we describe future directions for bone metastasis management, focusing on novel bone-specific targeted therapies.

Statin use in primary inflammatory breast cancer: a cohort study.

Abstract: Some studies have suggested that statins, which have cholesterol-lowering and anti-inflammatory properties, may have antitumor effects. Effects of statins on inflammatory breast cancer (IBC) have never been studied. We reviewed 723 patients diagnosed with primary IBC in 1995–2011 and treated at The University of Texas MD Anderson Cancer Center. Statin users were defined as being on statins at the initial evaluation. Based on Ahern et al's statin classification (JNCI, 2011), clinical outcomes were compared by statin use and type (weakly lipophilic to hydrophilic (H-statin) vs lipophilic statins (L-statin)). We used the Kaplan–Meier method to estimate the median progression-free survival (PFS), overall survival (OS) and disease-specific survival (DSS), and a Cox proportional hazards regression model to test the statistical significance of potential prognostic factors. In the multivariable Cox model, H-statins were associated with significantly improved PFS compared with no statin (hazard ratio=0.49; 95% confidence interval=0.28–0.84; P<0.01); OS and DSS P-values were 0.80 and 0.85, respectively. For L-statins vs no statin, P-values for PFS, DSS, and OS were 0.81, 0.4, and 0.74, respectively. H-statins were associated with significantly improved PFS. A prospective randomised study evaluating the survival benefits of statins in primary IBC is warranted.

TIG1 Promotes the Development and Progression of Inflammatory Breast Cancer through Activation of Axl Kinase

Abstract: Inflammatory breast cancer (IBC) is the most lethal form of breast cancer, but the basis for its aggressive properties are not fully understood. In this study, we report that high tumoral expression of TIG1 (RARRES1), a functionally undefined membrane protein, confers shorter survival in patients with IBC. TIG1 depletion decreased IBC cell proliferation, migration, and invasion in vitro and inhibited tumor growth of IBC cells in vivo. We identified the receptor tyrosine kinase, Axl, as a TIG1-binding protein. TIG1 interaction stablilized Axl by inhibiting its proteasome-dependent degradation. TIG1-depleted IBC cells exhibited reduced Axl expression, inactivation of NF-κB, and downregulation of matrix metalloproteinase-9, indicating that TIG1 regulates invasion of IBC cells by supporting the Axl signaling pathway in IBC cells. Consistent with these results, treatment of IBC cells with the Axl inhibitor SGI-7079 decreased their malignant properties in vitro. Finally, TIG1 expression correlated positively with Axl expression in primary human IBC specimens. Our findings establish that TIG1 positively modifies the malignant properties of IBC by supporting Axl function, advancing understanding of its development and rationalizing TIG1 and Axl as promising therapeutic targets in IBC treatment.

Comparison of molecular subtype distribution in triple-negative inflammatory and non-inflammatory breast cancers

Abstract: Because of its high rate of metastasis, inflammatory breast cancer (IBC) has a poor prognosis compared with non-inflammatory types of breast cancer (non-IBC). In a recent study, Lehmann and colleagues identified seven subtypes of triple-negative breast cancer (TNBC). We hypothesized that the distribution of TNBC subtypes differs between TN-IBC and TN-non-IBC. We determined the subtypes and compared clinical outcomes by subtype in TN-IBC and TN-non-IBC patients. We determined TNBC subtypes in a TNBC cohort from the World IBC Consortium for which IBC status was known (39 cases of TN-IBC; 49 cases of TN-non-IBC). We then determined the associations between TNBC subtypes and IBC status and compared clinical outcomes between TNBC subtypes. We found the seven subtypes exist in both TN-IBC and TN-non-IBC. We found no association between TNBC subtype and IBC status (P = 0.47). TNBC subtype did not predict recurrence-free survival. IBC status was not a significant predictor of recurrence-free or overall survival in the TNBC cohort. Our data show that, like TN-non-IBC, TN-IBC is a heterogeneous disease. Although clinical characteristics differ significantly between IBC and non-IBC, no unique IBC-specific TNBC subtypes were identified by mRNA gene-expression profiles of the tumor. Studies are needed to identify the subtle molecular or microenvironmental differences that contribute to the differing clinical behaviors between TN-IBC and TN-non-IBC.

The antihelmintic drug pyrvinium pamoate targets aggressive breast cancer.

Abstract: WNT signaling plays a key role in the self-renewal of tumor initiation cells (TICs). In this study, we used pyrvinium pamoate (PP), an FDA-approved antihelmintic drug that inhibits WNT signaling, to test whether pharmacologic inhibition of WNT signaling can specifically target TICs of aggressive breast cancer cells. SUM-149, an inflammatory breast cancer cell line, and SUM-159, a metaplastic basal-type breast cancer cell line, were used in these studies. We found that PP inhibited primary and secondary mammosphere formation of cancer cells at nanomolar concentrations, at least 10 times less than the dose needed to have a toxic effect on cancer cells. A comparable mammosphere formation IC50 dose to that observed in cancer cell lines was obtained using malignant pleural effusion samples from patients with IBC. A decrease in activity of the TIC surrogate aldehyde dehydrogenase was observed in PP-treated cells, and inhibition of WNT signaling by PP was associated with down-regulation of a panel of markers associated with epithelial-mesenchymal transition. In vivo, intratumoral injection was associated with tumor necrosis, and intraperitoneal injection into mice with tumor xenografts caused significant tumor growth delay and a trend toward decreased lung metastasis. In in vitro mammosphere-based and monolayer-based clonogenic assays, we found that PP radiosensitized cells in monolayer culture but not mammosphere culture. These findings suggest WNT signaling inhibition may be a feasible strategy for targeting aggressive breast cancer. Investigation and modification of the bioavailability and toxicity profile of systemic PP are warranted.

Genomic and expression analysis of microdissected inflammatory breast cancer

Abstract: Inflammatory breast cancer (IBC) is a unique clinical entity characterized by rapid onset of erythema and swelling of the breast often without an obvious breast mass. Many studies have examined and compared gene expression between IBC and non-IBC (nIBC), repeatedly finding clusters associated with receptor subtype, but no consistent gene signature associated with IBC has been validated. Here we compared microdissected IBC tumor cells to microdissected nIBC tumor cells matched based on estrogen and HER-2/neu receptor status. Gene expression analysis and comparative genomic hybridization were performed. An IBC gene set and genomic set were identified using a training set and validated on the remaining data. The IBC gene set was further tested using data from IBC consortium samples and publicly available data. Receptor driven clusters were identified in IBC; however, no IBC-specific gene signature was identified. Fifteen genes were correlated between increased genomic copy number and gene overexpression data. An expression-guided gene set upregulated in the IBC training set clustered the validation set into two clusters independent of receptor subtype but segregated only 75 % of samples in each group into IBC or nIBC. In a larger consortium cohort and in published data, the gene set failed to optimally enrich for IBC samples. However, this gene set had a high negative predictive value for excluding the diagnosis of IBC in publicly available data (100 %). An IBC enriched genomic data set accurately identified 10/16 cases in the validation data set. Even with microdissection, no IBC-specific gene signature distinguishes IBC from nIBC. Using microdissected data, a validated gene set was identified that is associated with IBC tumor cells. Inflammatory breast cancer comparative genomic hybridization data are presented, but a validated genomic data set that identifies IBC is not demonstrated.

Allogeneic hematopoietic cell transplantation for neuroblastoma: the CIBMTR experience

Abstract: Although the role of autologous hematopoietic cell transplantation (auto-HCT) is well established in neuroblastoma (NBL), the role of allogeneic HCT (allo-HCT) is controversial. The Center for International Blood and Marrow Transplant Research conducted a retrospective review of 143 allo-HCT for NBL reported in 1990-2007. Patients were categorized into two different groups: those who had not (Group 1) and had (Group 2) undergone a prior auto-HCT (n=46 and 97, respectively). One-year and five-year OS were 59% and 29% for Group 1 and 50% and 7% for Group 2, respectively. Among donor types, disease-free survival (DFS) and OS were significantly lower for unrelated transplants at 1 and 3 years but not at 5 years post HCT. Patients in CR or very good partial response (VGPR) at transplant had lower relapse rates and better DFS and OS, compared with those not in CR or VGPR. Our analysis indicates that allo-HCT can cure some neuroblastoma patients, with lower relapse rates and improved survival in patients without a history of prior auto-HCT as compared with those patients who had previously undergone auto-HCT. Although the data do not address why either strategy was chosen for patients, allo-HCT after a prior auto-HCT appears to offer minimal benefit. Disease recurrence remains the most common cause of treatment failure.

Adding hormonal therapy to chemotherapy and trastuzumab improves prognosis in patients with hormone receptor-positive and human epidermal growth factor receptor 2-positive primary breast cancer

Abstract: Adjuvant hormonal therapy for hormone receptor (HR)-positive primary breast cancer patients and a human epidermal growth factor receptor 2 (HER2)-targeted agent for HER2-positive primary breast cancer patients are standard treatment. However, it is not well known whether adding hormonal therapy to the combination of preoperative or postoperative chemotherapy and HER2-targeted agent contributes any additional clinical benefit in patients with HR-positive/HER2-positive primary breast cancer regardless of cross-talk between HR and HER2. We retrospectively reviewed records from 897 patients with HR-positive/HER2-positive primary breast cancer with clinical stage I-III disease who underwent surgery between 1988 and 2009. We determined the overall survival (OS) and disease-free survival (DFS) rates according to whether they received hormonal therapy or not and according to the type of hormonal therapy, tamoxifen and aromatase inhibitor, they received. The median followup time was 52.8 months (range 1-294.6 months). Patients who received hormonal therapy with chemotherapy and trastuzumab (n = 128) had significantly higher OS and DFS rates than did those who received only chemotherapy and trastuzumab (n = 46) in log-rank analysis (OS 96.1 vs. 87.0 %, p = 0.023, DFS 86.7 vs. 78.3 %, p = 0.029). There was no statistical difference in OS or DFS between those given an aromatase inhibitor and those given tamoxifen. In multivariate analysis, receiving hormonal therapy in addition to the combination of chemotherapy and trastuzumab was the sole independent prognostic factor for DFS (hazard ratio 0.446; 95 % CI 0.200-0.992; p = 0.048), and there was a similar trend in OS. Our study supported that hormonal therapy, whether in the form of an aromatase inhibitor or tamoxifen, confers a survival benefit when added to chemotherapy and trastuzumab in patients with HR-positive/HER2-positive primary breast cancer. Adjuvant treatment without hormonal therapy is inferior for this patient population.

Latest biopsy approach for suspected metastases in patients with breast cancer.

Abstract: Biopsy of suspected metastases in patients with breast cancer is recommended in the practice guidelines of the National Comprehensive Cancer Network, but not always performed in routine oncology practice, often because of the cost and invasiveness of the procedure. Biopsies can confirm the presence of metastatic disease, reveal unsuspected benign disease or second (non-breast) malignancies and confirm expression of biomarkers, all of which can aid the optimal management of the cancer. Image-guided biopsy has increased the accuracy and safety of the procedure. Here, we aim to provide a practical algorithm for deciding when to perform biopsy of suspected breast cancer metastases, in order to optimize clinical practice. We expect that future clinical trials and standard-of-care practice will increasingly obtain tissue from metastases to assess molecular differences (DNA, RNA, protein) between the primary tumour and metastases. Advances in targeted therapy for breast cancer will be highly dependent on the availability of metastatic tissue. In this article, we provide an up-to-date review of the current issues in biopsy of suspected metastases in patients with breast cancer, including technical details of biopsy, pathology review of biopsy specimens, and interpretation of biopsy findings.

Status of the anaplastic lymphoma kinase (ALK) gene in inflammatory breast carcinoma

Abstract: Background Although preliminary reports suggest that ALK gene amplification may occur in inflammatory breast cancer (IBC), data are limited. We performed a comprehensive investigation of the status of ALK gene in IBC.

(18)F-FDG PET/CT predicts survival in patients with inflammatory breast cancer undergoing neoadjuvant chemotherapy.

Abstract: Purpose The objective of this study was to evaluate the role of 18F-FDG PET/CT in predicting overall survival in inflammatory breast cancer patients undergoing neoadjuvant chemotherapy.

A Brief Review of the Biophysical Hallmarks of Metastatic Cancer Cells.

Abstract: A hallmark of metastatic cancer cells is their invasion through the basal membrane and endothelial layer, which requires a highly elastic cytoskeleton and nucleus. Therefore, cellular deformability can serve as a universal biophysical marker for detecting a tumor's propensity for invasion, migration, and metastasis. In this review, we define the importance of the biophysical features of cancer cells in tumor metastasis and summarize the state-of-the-art technology for the study of cell biomechanics. This review will serve as a brief introduction to the interdisciplinary character of cancer cell biophysics for cancer biologists, physicists, and engineers.

Bisphosphorylated PEA-15 Sensitizes Ovarian Cancer Cells to Paclitaxel by Impairing the Microtubule-Destabilizing Effect of SCLIP

Abstract: Paclitaxel is a standard chemotherapeutic agent for ovarian cancer. PEA-15 (phosphoprotein enriched in astrocytes-15 kDa) regulates cell proliferation, autophagy, apoptosis, and glucose metabolism and also mediates AKT-dependent chemoresistance in breast cancer. PEA-15's functions are tightly regulated by its phosphorylation status at Ser104 and Ser116. However, the effect of PEA-15 phosphorylation status on chemosensitivity of cancer cells remains unknown. Here, we tested the hypothesis that PEA-15 phosphorylated at both Ser104 and Ser116 (pPEA-15) sensitizes ovarian cancer cells to paclitaxel. We first found that knockdown of PEA-15 in PEA-15-high-expressing HEY and OVTOKO ovarian cancer cells resulted in paclitaxel resistance, whereas re-expression of PEA-15 in these cells led to paclitaxel sensitization. We next found that SKOV3.ip1-DD cells (expressing phosphomimetic PEA-15) were more sensitive to paclitaxel than SKOV3.ip1-AA cells (expressing nonphosphorylatable PEA-15). Compared to SKOV3.ip1-vector and SKOV3.ip1-AA cells, SKOV3.ip1-DD cells displayed reduced cell viability, inhibited anchorage-independent growth, and augmented apoptosis when treated with paclitaxel. Furthermore, HEY and OVTOKO cells displayed enhanced paclitaxel sensitivity when transiently overexpressing phosphomimetic PEA-15 and reduced paclitaxel sensitivity when transiently overexpressing nonphosphorylatable PEA-15. These results indicate that pPEA-15 sensitizes ovarian cancer cells to paclitaxel. cDNA microarray analysis suggested that SCLIP (SCG10-like protein), a microtubule (MT)-destabilizing protein, is involved in pPEA-15-mediated chemosensitization. We found that reduced expression and possibly posttranslational modification of SCLIP following paclitaxel treatment impaired SCLIP's MT-destabilizing effect, thereby promoting induction of mitotic arrest and apoptosis by paclitaxel. Our findings highlight the importance of pPEA-15 as a promising target for improving the efficacy of paclitaxel-based therapy in ovarian cancer.

Breast Cancer Biomarkers: Utility in Clinical Practice.

Abstract: Breast cancer is a heterogeneous disease. For the past decades, new technical tools have been developed for biomarkers at the DNA, RNA, and protein levels to better understand the biology of breast cancer. This progress is essential to classify the disease into clinically relevant subtypes, which may lead to new therapeutic opportunities. Novel biomarker development is paramount to deliver personalized cancer therapies. Further, tumor evolution, being natural or under treatment pressure, should be monitored and “liquid biopsies” by detecting circulating tumor cells or circulating free tumor DNA in blood samples will become an important option. This article reviews the new generation of biomarkers and the current evidence to demonstrate their analytical validity, clinical validity and clinical utility.

Differential pathologic complete response rates after neoadjuvant chemotherapy among molecular subtypes of triple-negative breast cancer.

Abstract: 1005 Background: By gene profiling, Lehmann et al. (J Clin Invest 121:2750-2767, 2011) reported that triple-negative breast cancer (TNBC) can be classified into 6 clusters—basal-like 1 (BL1), basal...

Novel functional assay for spindle-assembly checkpoint by cyclin-dependent kinase activity to predict taxane chemosensitivity in breast tumor patient.

Abstract: Taxanes are among the drugs most commonly used for preoperative chemotherapy for breast cancer. Taxanes induce mitotic arrest and subsequent apoptosis. The spindle-assembly checkpoint (SAC) is known to be activated during mitosis, along with cyclin-dependent kinase-1 (CDK1), and is required for taxane-induced cell death. We hypothesized that CDK1 activity predicts response to taxane-containing chemotherapy. This study included breast cancer patients who received preoperative chemotherapy- taxane-containing treatment followed by anthracycline-based treatment-and then underwent surgery. Before starting taxane-containing chemotherapy, patients underwent fine-needle aspiration biopsy, and the biopsy samples were incubated in paclitaxel solution to measure CDK activity. Clinical were evaluated after taxane therapy, and pathological resposes were evaluated after completion of all preoperative chemotherapy. Thirty five patients were eligible for analysis of clinical response to taxane-containing therapy. Twenty-six patients had taxane-sensitive and 9 taxane-resistant tumors. Using a cut-off of CDK activity determined by the ROC analysis, patients were classified into SAC function and dysfunction groups. Univariate logistic regression analysis with clinicopathologic parameters showed that only CDK-based SAC functionality was significantly correlated with clinical response (P =0.017). No significant correlation was observed between SAC functionality and pathologic response. CDK-based SAC functionality significantly predicted clinical response (P =.0072, overall agreement = 71.4%), and this is a unique mechanism-based marker for predicting taxane chemosensitivity. Further, large prospective study is needed to determine CDK-based SAC functionality could be developed as a predictive biomarker.

Paclitaxel and Trastuzumab as Maintenance Therapy in Patients with HER2-Positive Metastatic Breast Cancer Who Underwent High-Dose Chemotherapy and Autologous Hematopoietic Stem Cell Transplantation

Abstract: We examined the feasibility and safety of using paclitaxel and trastuzumab as maintenance therapy after high-dose chemotherapy (HDC) with autologous hematopoietic stem cell transplantation (AHST) for patients with HER2-positive metastatic breast cancer. Ten patients (9 women and 1 man) were enrolled in the study. The median age was 46.5 years (range, 27-65 years). The median follow-up time was 1003 days (range, 216-2526 days). All patients had metastatic disease, but 2 had only bone metastasis. One patient had complete response, 6 had partial response and 3 had stable disease to the standard-dose chemotherapy prior to transplantation. The conditioning regimen consisted of cyclophosphamide, carmustine, and thiotepa. After AHST, patients received weekly paclitaxel for 12 doses and trastuzumab every 3 weeks for 1 year as maintenance therapy. All patients experienced successful engraftment. The only grade 4 toxic effects observed were leukopenia and thrombocytopenia. The most common grade 3 toxic effect was neutropenic fever. No treatment-related deaths were observed. The median progression-free survival time was 441 days, and the median overall survival time was 955 days. Two patients died in accidents while their disease remained in remission. Five patients died with disease progression. At the time of this report, 3 patients are alive with stable disease, 1 of whom has remained free of disease progression for 2526 days since transplantation. Our findings indicate that paclitaxel plus trastuzumab as maintenance therapy after HDC with AHST for patients with HER2-positive metastatic breast cancer not only is feasible and safe but also results in survival outcomes similar to historical results.

Change in HER2 status during breast tumor progression

Abstract: The HER2 status of breast cancers is routinely assessed using the testing algorithm standardized by the American Society of Clinical Oncology and the College of American Pathologists, which includes immunohistochemical analysis of HER2 protein expression and fluorescence in situ hybridization (FISH) analysis of HER2 gene copy number. Studies have suggested that HER2 status may differ between primary and metastatic tumors. Furthermore, studies have suggested that trastuzumab may convert HER2 status from positive in a primary tumor to negative in a metastatic site. Assessment of HER2 status is affected by aspects of the pathologic analysis, including the method of tumor sampling, the method of specimen fixation, whether immunohistochemical or FISH analysis is used. In this review, we discuss the clinical significance of HER2 discordance in breast cancer. Moreover, the importance of tumor sample handling in assessing HER2-positivity.

Breast cancer evaluation and targeted investigational therapy (BEAT-IT): A pilot prospective tissue testing to guide clinical trial selection.

Abstract: 532 Background: An increasing number of molecularly targeted drugs are now available in Phase I and II clinical trials. Many of these drugs target specific molecular abnormalities such as mutated, ...

Abstract B51: ApoStream™ isolated circulating tumor cells from primary breast cancer patients reveals heterogeneous phenotypes related to epithelial-mesenchymal transition and stem cell markers.

Abstract: Background: Detection of circulating tumor cells (CTCs) is an indicator of poor prognosis in patients with metastatic breast cancer and not in primary breast cancer (PBC). The classical phenotypic definition of a CTC is a nucleated cell that is cytokeratin (CK) positive but CD45 negative. Several reports have shown that EpCAM based capture methods detect only a fraction of CTCs and not the heterogeneous subpopulations of CTCs. Moreover, subsets of CTCs may acquire a more aggressive phenotype with features of invasiveness and motility by undergoing an epithelial to mesenchymal transition (EMT) and down regulate the epithelial cell adhesion molecule, EpCAM. EMT is a hallmark of cellular invasion and metastasis and CTCs undergoing EMT may express the putative cancer stem cell like phenotype, CD24lowCD44+. CTCs undergoing EMT (CTC-EMT) are not readily detected by current CTC detection technologies. Thus, it is desirable to isolate CTCs using capture methods independent of EpCAM to recover a heterogeneous CTC population for more extensive characterization. Here we use ApoStream™, a novel antibody-free CTC isolation device that does not rely on EpCAM to capture circulating rare cells, to evaluate the molecular heterogeneity of CTCs. Methods: Baseline blood samples from 14 newly diagnosed PBC patients were collected and processed using ApoStream™. Isolated cells were stained with anti-CK and anti-CD45, and DAPI. In addition, a multiplexed immunofluorescence assay and laser scanning cytometry analysis were applied to identify multiple combinations of CK+CD45− cells for the expression and distribution of EpCAM, vimentin, CD44, CD24, β-catenin and E-cadherin. Results: ApoStream™ recovered both EpCAM+ and EpCAM− cells. CK+CD45− cells were detected in 9 out of 14 PBC patients. The expression of EpCAM− vimentin+ in the CK+CD45− population was heterogeneous across the patient population. E-cadherin and β-catenin were detected in 0-94% (Mean 52 %) and 0-37% (Mean 8 %), respectively of the CK+CD45− population. All patients with CK+CD45− cells had a subset of cells with the putative phenotype of CD44+CD24low cells. Conclusions: Heterogeneous CTC phenotypes with CD44+CD24lowin both EpCAM+ and EpCAM− cells were observed in patients with PBC. Our aim is to correlate ApoStream™ EMT-CTC counts in patients with PBC with the pathological clinical response (pCR). This study will continue to enroll PBC patients and test the hypothesis that low EMT-CTC count patients have higher pCR rates compared to high EMT-CTC count patients. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B51. Citation Format: Kenna L. Anderes, Insiya Jafferji, Vladislava O. Melnikova, Jackson A. Summer, Darren W. Davis, James M. Reuben, Naoto T. Ueno. ApoStream™ isolated circulating tumor cells from primary breast cancer patients reveals heterogeneous phenotypes related to epithelial-mesenchymal transition and stem cell markers. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B51.

Abstract 3241: Preclinical development of JNK-targeted therapy for triple-negative breast cancer.

Abstract: Patients with triple-negative breast cancer (TNBC), which is negative for estrogen receptor, progesterone receptor, and HER2, have a very poor prognosis due to metastasis and limited targeted therapies. JNK (c-Jun N-terminal kinase) signaling promotes tumorigenesis and metastasis and regulates cancer stem cell self-renewal and maintenance in glioma, and the JNK pathway is hyperactivated in basal-like TNBC. Therefore, we hypothesized that suppressing JNK activity inhibits tumorigenesis and metastasis of TNBC cells. To test our hypothesis, we generated several JNK-targeted JIP (JNK-interacting protein) mimetic peptides as well as the small molecule JNK inhibitor JNK-In-8 and assessed their therapeutic potential in TNBC cells. JIP mimetic peptides were designed and synthesized on the basis of the D-site of JIP, which is critical for JNK binding. All the peptides and JNK-In-8 specifically inhibited JNK kinase activity. Because of high JNK specificity, JIP2 (JIP peptide) and JNK-In-8 were chosen for bioactivity studies. JIP2 (10 μM) inhibited phosphorylation of JNK and its substrate c-Jun in HEK293 cells. Similar results were observed for JNK-In-8 (0.5 μM) in SUM149 and MDA-MB-231 cells. However, whereas JIP2 was not cytotoxic against SUM149 and MDA-MB-231 cells, JNK-In-8 (IC50=4.0 μM) significantly inhibited proliferation of these cells by inducing G1 cell-cycle arrest at low doses and apoptosis at high doses. Furthermore, SUM149 and MDA-MB-231 cells treated with JNK-In-8 (2.5 μM, P JIP2 (10 μM) strongly inhibited SUM149 cell migration (42.02%, P Interestingly, JNK-In-8 (2.5 μM) also reduced the proportion of CD44+ CD24- cells (SUM149: DMSO 50.23% vs JNK-In-8 40.41%) and that of ALDH1+ cells (SUM149: DMSO 38.25% vs JNK-In-8 25.84%; MDA-MB-231: DMSO 19.94% vs JNK-In-8 9.21%) as well as mammosphere formation (SUM149: 65.95%, P Our data demonstrate that JNK inhibitors may inhibit tumorigenesis and metastasis of TNBC cells by suppressing cancer stem cell maintenance and that JNK may serve as a promising target for TNBC therapy. Further studies will be conducted to determine the molecular mechanisms of JIP2- and JNK-In-8-mediated antitumor action in TNBC and the therapeutic efficacy of JIP2 and JNK-In-8 in a TNBC xenograft mouse model. Citation Format: Xuemei Xie, Tamer S. Kaoud, Ramakrishna Edupuganti, Rachel M. Sammons, Gabriel N. Hortobagyi, Naoto T. Ueno, Kevin N. Dalby, Chandra Bartholomeusz. Preclinical development of JNK-targeted therapy for triple-negative breast cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3241. doi:10.1158/1538-7445.AM2013-3241