Label-free Raman spectroscopy provides early determination and precise localization of breast cancer-colonized bone alterations.

Breast neoplasms frequently colonize bone and induce development of osteolytic bone lesions by disrupting the homeostasis of the bone microenvironment. This degenerative process can lead to bone pain and pathological bone fracture, a major cause of cancer morbidity and diminished quality of life, which is exacerbated by our limited ability to monitor early metastatic disease in bone and assess fracture risk. Spurred by its label-free, real-time nature and its exquisite molecular specificity, we employed spontaneous Raman spectroscopy to assess and quantify early metastasis driven biochemical alterations to bone composition.

CITED2 attenuates macrophage recruitment concordant with the downregulation of CCL20 in breast cancer cells.

The transcriptional co-regulator Cbp/p300-interacting transactivator with Glu/Asp-rich carboxy-terminal domain-2 (CITED2) may promote breast tumor growth; however, the mechanisms by which its effects are mediated remain to be fully elucidated. Tumor-associated macrophages serve an important function in tumor development and progression and are recruited by chemotactic factors produced by cells within the tumor microenvironment. The present study assessed the effects of CITED2 silencing on macrophage recruitment in two xenograft mouse models of human breast cancer, one in which tumor growth was sensitive to CITED2 silencing (MDA-MB-231) and one in which it was insensitive (MDA-MB-468).

Down-regulation of CITED2 attenuates breast tumor growth, vessel formation and TGF-β-induced expression of VEGFA.

While we previously demonstrated that CITED2 expression in primary breast tumor tissues is elevated relative to normal mammary epithelium and inversely correlated with patient survival, its functional impact on primary tumor development and progression remained unknown. To address this issue, we examined the effect of CITED2 silencing on the growth of human breast cancer cell lines MDA-MB-231 and MDA-MB-468 following orthotopic administration in vivo. Here, we show that CITED2 silencing significantly attenuated MDA-MB-231 primary tumor growth concordant with reduced tumor vascularization, while MDA-MB-468 primary tumor growth and tumor vascularization remained unaffected.

CITED2 Modulates Breast Cancer Metastatic Ability through Effects on IKKα.

Unlabelled: Previously, we identified the transcriptional coactivator CITED2 as a potential facilitator of bone metastasis using a murine mammary cancer model. Extending these studies to human breast cancer, it was observed that CITED2 mRNA expression was significantly elevated in patient specimens of metastatic breast cancer relative to primary tumors, with highest levels in metastasis to bone relative to non-bone sites. To further evaluate CITED2 functions in breast cancer metastasis, CITED2 expression was stably reduced in the human breast cancer cell lines MDA-MB-231 and MDA-MB-468, which are metastatic in animal models.

CCL20/CCR6 Signaling Regulates Bone Mass Accrual in Mice.

CCL20 is a member of the macrophage inflammatory protein family and is reported to signal monogamously through the receptor CCR6. Although studies have identified the genomic locations of both Ccl20 and Ccr6 as regions important for bone quality, the role of CCL20/CCR6 signaling in regulating bone mass is unknown. By micro-computed tomography (μCT) and histomorphometric analysis, we show that global loss of Ccr6 in mice significantly decreases trabecular bone mass coincident with reduced osteoblast numbers.

Enpp1: a potential facilitator of breast cancer bone metastasis.

Bone is the most common site of breast cancer metastasis and once established, it is frequently incurable. Critical to our ability to prevent and treat bone metastasis is the identification of the key factors mediating its establishment and understanding their biological function. To address this issue we previously carried out an in vivo selection process to isolate murine mammary tumor sublines possessing an enhanced ability to colonize the bone.

CITED2 modulates estrogen receptor transcriptional activity in breast cancer cells.

Cbp/p300-interacting transactivator with Glu/Asp-rich carboxy-terminal domain 2 (CITED2) is a member of the CITED family of non-DNA binding transcriptional co-activators of the p300/CBP-mediated transcription complex. Previously, we identified CITED2 as being overexpressed in human breast tumors relative to normal mammary epithelium. Upon further investigation within the estrogen receptor (ER)-positive subset of these breast tumor samples, we found that CITED2 mRNA expression was elevated in those associated with poor survival.

MIP-1δ activates NFATc1 and enhances osteoclastogenesis: involvement of both PLCγ2 and NFκB signaling.

Pathological bone resorption is a source of significant morbidity in diseases affecting the skeleton such as rheumatoid arthritis, periodontitis, and cancer metastasis to bone. Evidence indicates that elevated levels of inflammatory mediators such as IL-1, IL-6, and TNF-α play a role in this process by promoting the formation of bone-resorbing osteoclasts. Additionally, current studies have identified inflammatory chemokines of the macrophage inflammatory protein (MIP) family as potential mediators of pathological bone resorption, where both MIP-1α and -3α have been shown to enhance osteoclast (OCL) development.

Preclinical and clinical evaluation of intraductally administered agents in early breast cancer.

Most breast cancers originate in the epithelial cells lining the breast ducts. Intraductal administration of cancer therapeutics would lead to high drug exposure to ductal cells and eliminate preinvasive neoplasms while limiting systemic exposure. We performed preclinical studies in N-methyl-N'-nitrosourea-treated rats to compare the effects of 5-fluorouracil, carboplatin, nanoparticle albumin-bound paclitaxel, and methotrexate to the previously reported efficacy of pegylated liposomal doxorubicin (PLD) on treatment of early and established mammary tumors.

Identification of prospective factors promoting osteotropism in breast cancer: a potential role for CITED2.

Breast cancer metastases develop in the bone more frequently than any other site and are a common cause of morbidity in the form of bone pain, pathological fractures, nerve compression and life-threatening hypercalcemia. Despite ongoing research efforts, the molecular and cellular mechanisms that regulate breast cancer cell homing to and colonization of the bone as well as resultant pathological bone alteration remain poorly understood. To identify key mediators promoting breast cancer metastasis to bone, we utilized an immunocompetent, syngeneic murine model of breast cancer metastasis employing the mammary tumor cell line NT2.

MMP-13 is over-expressed in renal cell carcinoma bone metastasis and is induced by TGF-beta1.

Bone metastasis occurs frequently in renal cell carcinoma (RCC) patients causing significant morbidity by stimulating excessive osteolysis, yet the mechanisms responsible have been little studied. Matrix metalloproteinases (MMPs) are over-expressed in many cancer types and are believed to play a role in bone metastasis, however, the expression of MMPs in RCC bone metastasis (RBM) has not been investigated. Due to their ability to degrade the main component of organic bone matrix, type I collagen, we investigated the expression of MMP-1, -2, -8, -9, and -13 in RBM.

Macrophage inflammatory protein-1 delta: a novel osteoclast stimulating factor secreted by renal cell carcinoma bone metastasis.

Approximately 30% of patients with renal cell carcinoma (RCC) develop bone metastasis, which is characterized by extensive osteolysis leading to severe bone pain and pathologic fracture. Although the mechanism of RCC-induced osteolysis is unknown, studies of bone metastasis have shown that tumor-induced changes in bone remodeling are likely mediated by alterations in the bone microenvironment. Here, we report the discovery of a novel osteoclast stimulatory factor secreted by RCC bone metastasis (RBM).

Clostridium perfringens enterotoxin as a novel-targeted therapeutic for brain metastasis.

Brain metastasis is the most commonly occurring intracranial tumor whose incidence seems to be increasing. With standard therapy, the average survival time of patients is approximately 8 months, and treatment often leads to neurologic dysfunction in long-term survivors, emphasizing the need for novel therapeutics. Clostridium perfringens enterotoxin (CPE) has recently been shown to rapidly and specifically destroy cancer cells expressing CPE receptors claudin-3 and claudin-4.

TGF-beta promotes the establishment of renal cell carcinoma bone metastasis.

Unlabelled: Bone metastases develop in approximately 30% of patients with RCC, and the mechanisms responsible for this phenomenon are unknown. We found that TGF-beta1 stimulation of RCC bone metastasis cells promotes tumor growth and bone destruction possibly by stimulating paracrine interactions between tumor cells and the bone.

Introduction: Bone metastasis is a frequent complication and causes marked morbidity in patients with renal cell carcinoma (RCC).

Claudins: emerging targets for cancer therapy.

The claudin (CLDN) family of transmembrane proteins plays a critical role in the maintenance of epithelial and endothelial tight junctions. In addition to their function in preserving the structure of tight junctions, CLDNs might also play a role in the maintenance of the cytoskeleton and in cell signalling. Interestingly, several studies have recently reported specific CLDN family members to be overexpressed in a wide variety of cancer types.

Ductal access for prevention and therapy of mammary tumors.

In cancer patients and in those at high risk, systemic exposure to agents for therapy or prevention is accompanied by undesirable side effects. We hypothesized that it is possible to prevent and treat breast cancer by introducing anticancer agents into the mammary ductal network. Here, we show the efficacy of intraductally administered anticancer agents 4-hydroxytamoxifen and pegylated liposomal doxorubicin (PLD) in the prevention and treatment of breast cancer using the rat N-methyl-N'-nitrosourea-induced and spontaneous HER-2/neu transgenic mouse (neu-N) models of breast cancer.

Very high frequency of hypermethylated genes in breast cancer metastasis to the bone, brain, and lung.

Purpose: Most often it is not the primary tumor, but metastasis to distant organs that results in the death of breast cancer patients. To characterize molecular alterations in breast cancer metastasis, we investigated the frequency of hypermethylation of five genes (Cyclin D2, RAR-beta, Twist, RASSF1A, and HIN-1) in metastasis to four common sites: lymph node, bone, brain, and lung.

Experimental Design: Methylation-specific PCR for the five genes was performed on DNA extracted from archival paraffin-embedded specimens of paired primary breast cancer and its lymph nodes (LN) metastasis (n = 25 each); in independent samples of metastasis to the bone (n = 12), brain (n = 8), and lung (n = 10); and in normal bone, brain, and lung (n = 22).

Clostridium perfringens enterotoxin elicits rapid and specific cytolysis of breast carcinoma cells mediated through tight junction proteins claudin 3 and 4.

Clostridium perfringens enterotoxin (CPE) induces cytolysis very rapidly through binding to its receptors, the tight junction proteins CLDN 3 and 4. In this study, we investigated CLDN 3 and 4 expression in breast cancer and tested the potential of CPE-mediated therapy. CLDN 3 and 4 proteins were detected in all primary breast carcinomas tested (n = 21) and, compared to normal mammary epithelium, were overexpressed in approximately 62% and 26%, respectively.

Loss of the tight junction protein claudin-7 correlates with histological grade in both ductal carcinoma in situ and invasive ductal carcinoma of the breast.

Claudins are transmembrane proteins that seal tight junctions, and are critical for maintaining cell-to-cell adhesion in epithelial cell sheets. However, their role in cancer progression remains largely unexplored. Here, we report that Claudin-7 (CLDN-7) expression is lower in invasive ductal carcinomas (IDC) of the breast than in normal breast epithelium, as determined by both RT-PCR (9/10) and Western analysis (6/8).