Currently, there is no effective therapy for metastatic breast cancer after surgery, radiation, and chemotherapy have been used against the primary tumor. Because curcumin suppresses nuclear factor-nB (NF-nB) activation and most chemotherapeutic agents activate NF-nB that mediates cell survival, proliferation, invasion, and metastasis, we hypothesized that curcumin would potentiate the effect of chemotherapy in advanced breast cancer and inhibit lung metastasis. We tested this hypothesis using paclitaxel (Taxol)-resistant breast cancer cells and a human breast cancer xenograft model. As examined by electrophoretic mobility gel shift assay, paclitaxel activated NF-nB in breast cancer cells and curcumin inhibited it; this inhibition was mediated through inhibition of InBa kinase activation and InBa phosphorylation and degradation. Curcumin also suppressed the paclitaxel-induced expression of antiapoptotic (XIAP, IAP-1, IAP-2, Bcl-2, and Bcl-xL), proliferative (cyclooxygenase 2, c-Myc, and cyclin D1), and metastatic proteins (vascular endothelial growth factor, matrix metalloproteinase-9, and intercellular adhesion molecule-1). It also enhanced apoptosis. In a human breast cancer xenograft model, dietary administration of curcumin significantly decreased the incidence of breast cancer metastasis to the lung and suppressed the expression of NF-nB, cyclooxygenase 2, and matrix metalloproteinase-9. Overall, our results indicate that curcumin, which is a pharmacologically safe compound, has a therapeutic potential in preventing breast cancer metastasis possibly through suppression of NF-nB and NF-nB^regulated gene products.Although early-stage breast cancer is highly treatable, no effective treatment is available for metastatic breast cancer that follows surgery, radiation, and chemotherapy for the primary tumor (1). Paclitaxel (Taxol) is currently used as the front-line chemotherapeutic agent in breast cancers (1); however, because the drug frequently induces drug resistance (2 -4), probably through the activation of nuclear factor-nB (NF-nB; ref. 5), it is not useful in treating advanced breast cancer.Curcumin (diferuloylmethane), a polyphenol (see Fig. 1A) derived from turmeric, Curcuma longa, is a pharmacologically safe and effective agent that can block NF-nB activation. Curcumin has been shown by us and others to suppress NFnB activation induced by various inflammatory stimuli (6) through inhibition of the activation of InBa kinase (IKK) activity needed for NF-nB activation (7,8). Based on the paclitaxel and curcumin data, we hypothesized that curcumin would improve the therapeutic outcome of paclitaxel treatment for breast cancer. We tested this hypothesis using breast cancer cells and a nude mouse xenograft model. Our goal was to determine whether curcumin can suppress paclitaxel-induced NF-nB activation and NF-nB -regulated gene products and prevent breast cancer metastasis to the lung. We found that curcumin did block paclitaxel-induced NF-nB activation and NF-nB -regulated gene expression in breast ...

Purpose:The chemokine receptors CCR7 and CXCR4 have been shown to play an important role in cancer metastasis.We therefore studied the differential expression of CCR7 and CXCR4, along with that of the biomarker HER2-neu, to evaluate whether these biomarkers could predict axillary lymph node metastasis in breast cancer. Experimental Design: Biomarker expression levels were evaluated using paraffin-embedded tissue sections of lymph node^negative (n = 99) and lymph node^positive (n = 98) T 1 breast cancer by immunohistochemical staining. Results: Lymph node^positive tumors showed higher rates of high cytoplasmic CCR7 staining (21.5% versus 8.5%, P = 0.013) and HER2-neu overexpression (21.5% versus 9.3%, P = 0.019) than did lymph node^negative tumors. Similarly, high cytoplasmic CXCR4 expression occurred more commonly in lymph node^positive tumors (11.2% versus 5.1%, P = 0.113). In contrast, predominantly nuclear CXCR4 staining was more likely to be found in lymph node^negative tumors (54.5% versus 37.8%, P = 0.018). Furthermore, cytoplasmic CXCR4 coexpressed with HER2-neu was the only factor associated with involvement of four or more lymph nodes (16.7% versus1.2%, P = 0.04) among lymph node^positive tumors.When all three biomarkers (CCR7, CXCR4, HER2-neu) were utilized together, 50.0% of lymph node^positive tumors highly expressed one of these biomarkers compared with 18.8% of the lymph node^negative tumors (P < 0.0001). Conclusions:Our results suggest that the chemokine receptor CCR7 is a novel biomarker that can predict lymph node metastases in breast cancer. Utilization of additional markers, such as CXCR4 and HER2-neu, further improves the prediction of the presence and extent of lymph node involvement.

The expression of various genes that regulate angiogenesis in human ovarian carcinomas is associated with the pattern of the disease and its progression. Therefore, targeting specific genes that regulate angiogenesis could offer new approaches to the treatment of ovarian cancer.

Trastuzumab shows remarkable efficacy in treatment of ErbB2-positive breast cancers when used alone or in combination with other chemotherapeutics. However, acquired resistance develops in most treated patients, necessitating alternate treatment strategies. Increased aerobic glycolysis is a hallmark of cancer and inhibition of glycolysis may offer a promising strategy to preferentially kill cancer cells. In this study, we investigated the antitumor effects of trastuzumab in combination with glycolysis inhibitors in ErbB2-positive breast cancer. We found that trastuzumab inhibits glycolysis via downregulation of heat shock factor 1 (HSF1) and lactate dehydrogenase A (LDH-A) in ErbB2-positive cancer cells, resulting in tumor growth inhibition. Moreover, increased glycolysis via HSF1 and LDH-A contributes to trastuzumab resistance. Importantly, we found that combining trastuzumab with glycolysis inhibition synergistically inhibited trastuzumab-sensitive and -resistant breast cancers in vitro and in vivo, due to more efficient inhibition of glycolysis. Taken together, our findings show how glycolysis inhibition can dramatically enhance the therapeutic efficacy of trastuzumab in ErbB2-positive breast cancers, potentially useful as a strategy to overcome trastuzumab resistance.

IntroductionDespite exciting progress in the understanding of breast cancer development and progression, and in the development of novel therapeutic strategies, breast cancer remains the second leading cause of cancer-related death in women, with a yearly toll of more than 40,000 deaths in the United States alone. Breast cancer-related deaths are mainly due to the "incurable" nature of metastatic breast cancer (MBC) at the current time. It is estimated that ∼6% of patients have metastatic disease at the time of diagnosis and 20% to 50% patients first diagnosed with primary breast cancer will eventually develop metastatic disease. Even with the remarkable advances in research and clinical management, the current treatment strategies for breast cancer metastasis still largely rely on the use of systemic cytotoxic agents, which frequently deteriorate the patient's life quality due to severe side effects and, in many cases, have limited long-term success. The prognosis for MBC patients is poor, with an estimated 5-year survival of only 26%. Therefore, MBC remains the most challenging task facing both cancer researcher and oncologist. To tackle this challenge, scientists and physicians of the Breast Cancer Research Program at the M.D. Anderson Cancer Center held a symposium to (a) provide a better understanding of breast cancer metastasis at the molecular and cellular level; (b) introduce cutting-edge technologies in metastatic breast cancer detection, including clinicopathologic detection, circulating tumor cells (CTC) detection, and advanced imaging; and (c) solicit innovative ideas in basic, translational research and clinical patient management. The symposium led to a positive consensus notion that we will be able to prevent, and to a lesser degree, treat metastasis and ultimately save most patients from metastatic deaths in the foreseeable future. The Challenges of Breast Cancer Brain MetastasisUnderstanding the molecular and biological basis of metastasis is essential for paving the way to conquering it. Dr. Patricia Steeg (National Cancer Institute, Bethesda, MD) set the stage on the challenges of understanding metastasis in her keynote speech: A Molecular Portrait of Brain Metastasis of Breast Cancer. Brain metastasis represents a devastating consequence of breast cancer, with a particularly dismal prognosis of ∼80% mortality within 1 year of diagnosis. The classic tools in treating brain metastasis, including neurosurgery, stereotactic radiosurgery, or whole brain radiation, are partially effective in treating large macrometastasis; however, these tools have limited effects on controlling small micrometastasis, many of which will grow and eventually become deadly to patients. Therefore, novel molecular therapies to eliminate or stabilize micrometastasis are urgently needed. However, the development of effective chemotherapy in treating brain metastasis has been especially challenging due to the limited permeability of the blood-brain barrier, which is considered a "sanctuary site" for tumor cells. To study b...

Patients with breast cancer brain metastases cannot be cured and have a poor prognosis, with a median survival time of six months after diagnosis, despite developments in diagnostic and therapeutic modalities. In large part the progress in understanding the biology of breast cancer brain metastasis has been limited by the lack of suitable cell lines and experimental models. The objective of this study was to develop a reliable experimental model to study the pathogenesis of breast cancer brain metastases, using intra-internal carotid artery injection of breast cancer cells into nude mice. Brain metastasis-selected variant cells were recovered after three cycles of injection into the internal carotid artery of nude mice and harvest of brain metastases, resulting in variants termed MDA-231 BR1, -BR2 and -BR3. The metastasis-selected cells had increased potential for experimental brain metastasis and mice injected with these cells had significantly shorter mean survival than mice injected with the original cell line. Brain metastatic lesions of the selected variants contained significantly more CD31-positive blood vessels than metastases of the non-selected cell line. The variants selected from brain metastases released significantly more VEGF-A and IL-8 into culture supernatants than the original cell line, and more VEGF-A RNA when cultured in normoxic conditions. Mice injected with MDA-231 BR3 into the carotid artery were treated with the VEGF-receptor tyrosine kinase inhibitor PTK787/Z 222584. Oral administration of the inhibitor resulted in a significant decrease in brain tumor burden, reduced CD31-positive vessels in the brain lesions and incidence of PCNA positive tumor cells, and increased apoptosis in the tumor, as measured by TUNEL labeling. We conclude that elevated VEGF expression contributes to the ability of breast cancer cells to form brain metastases. Targeting endothelial cells with a VEGF-receptor specific tyrosine kinase inhibitor reduced angiogenesis and restricted the growth of the brain metastases.

Experimental evidence suggests that CXCR4, a G i proteincoupled receptor for the ligand CXCL12/stromal cell-derived factor-1A (SDF-1A), plays a role in breast cancer metastasis. Transactivation of HER2-neu by G protein-coupled receptor activation has been reported as a ligand-independent mechanism of activating tyrosine kinase receptors. We found that SDF-1A transactivated HER2-neu in the breast cancer cell lines MDA-MB-361 and SKBR3, which express both CXCR4 and HER2-neu. AMD3100, a CXCR4 inhibitor, PKI 166, an epidermal growth factor receptor/HER2-neu tyrosine kinase inhibitor, and PP2, a Src kinase inhibitor, each blocked SDF-1A-induced HER2-neu phosphorylation. Blocking Src kinase, with PP2 or using a kinase-inactive Src construct, and inhibiting epidermal growth factor receptor/HER2-neu signaling with PKI 166 each inhibited SDF-1A-stimulated cell migration. We report a novel mechanism of HER2-neu transactivation through SDF-1A stimulation of CXCR4 that involves Src kinase activation.

The ATF/CREB family of eukaryotic transcription factors contain the bZIP structural motif and mediate their transcriptional activities via heterodimerization with ATF and AP-1 family members. Quenching of CREBassociated proteins by a dominant-negative CREB (KCREB) that is mutated within its DNA-binding domain decreases radiation resistance of human melanoma cells. The purpose of this study was to determine the role of CREB in tumor growth and metastasis of human melanoma using KCREB. Highly metastatic MeWo human melanoma cells were transfected with the KCREB expression vector and subsequently analysed for changes in their tumorigenic and metastatic potential. Expression of KCREB in MeWo human cells decreased their tumorigenic and metastatic potential in nude mice compared with parental and control transfected cells. The KCREB-transfected cells displayed downregulation of 72 kDa collagenase type IV (MMP-2) mRNA expression and activity and decreased invasiveness through Matrigel-coated ®lters. Moreover, transcriptional activities mediated by the CAT gene driven by the MMP-2 promoter were decreased by 14 ± 45-fold in KCREB-transfected cells. In addition, the cell-surface adhesion molecule MCAM/MUC18 that is involved in metastasis of human melanoma was downregulated in the KCREB-transfected cells. These data indicate that, through their transcriptional activities, CREB and its associated proteins play an important role in the acquisition of the metastatic phenotype of human melanoma cells.