Bone-derived soluble factors and laminin-511 cooperate to promote migration, invasion and survival of bone-metastatic breast tumor cells

Tumor intrinsic and extrinsic factors are thought to contribute to bone metastasis but little is known about how they cooperate to promote breast cancer spread to bone. We used the bone-metastatic 4T1BM2 mammary carcinoma model to investigate the cooperative interactions between tumor LM-511 and bone-derived soluble factors in vitro. We show that bone conditioned medium cooperates with LM-511 to enhance 4T1BM2 cell migration and invasion and is sufficient alone to promote survival in the absence of serum. These responses were associated with increased secretion of MMP-9 and activation of ERK and AKT signaling pathways and were partially blocked by pharmacological inhibitors of MMP-9, AKT-1/2 or MEK. Importantly, pre-treatment of 4T1BM2 cells with an AKT-1/2 inhibitor significantly reduced experimental metastasis to bone in vivo. Promotion of survival and invasive responses by bone-derived soluble factors and tumor-derived LM-511 are likely to contribute to the metastatic spread of breast tumors to bone.

Smoothened activates breast cancer stem-like cell and promotes tumorigenesis and metastasis of breast cancer

Smoothened (Smo) is a G protein-coupled receptor protein encoded by the Smo gene of the hedgehog signalling pathway, which is thought to play an important role in maintaining organ patterning, cell differentiation and self-renewal. The possible role of Smo in the process of tumorigenesis and metastasis of breast cancer still remains unclear. The present experiments were to investigate the effect of Smo on activating breast cancer stem-like CD44(+)CD24(-) cells and the tumorigenesis and metastasis of breast cancer. By injected CD44(+)CD24(-) cells (1×10(4)) into the cleared fat pad of NOD/SCID mice, it was observed that CD44(+)CD24(-) cells possess higher tumor-initiating capacity and metastasis properties than equal numbers of non-CD44(+)CD24(-) cells. The mRNA and protein expressions of Smo in CD44(+)CD24(-) cells were higher than those in non-CD44(+)CD24(-) cells, indicating that Smo may play a role in maintaining breast cancer stem cell features. qRT-PCR results revealed that expressions of STAT3, Bcl-2 and cyclinD1 mRNA in MCF-7 cells were decreased after transfected by Smo siRNA. In addition, the expressions of MMP-2 and MMP-9 were downregulated in MCF-7 cells after Smo expression was inhibited. Smo inhibition may be a possible therapeutic target that potentially suppresses breast tumor formation and development.

Upregulation of glutathione-related genes and enzyme activities in cultured human cells by sublethgal concentrations of inorganic arsenic

Inorganic arsenic (jAs), a known human carcinogen, acts as a tumor promoter in part by inducing a rapid burst of reactive oxygen species (ROS) in mammalian cells. This causes oxidative stress and a subsequent increase in the level of cellular glutathione (GSH). Glutathione, a ubiquitous reducing sulfhydryl tripeptide, is involved in ROS detoxification and its increase may be part of an adaptive response to the oxidative stress. Glutathione related enzymes including glutathione reductase (GR) and glutathione S-transferase (GST) also play key roles in these processes. In this study the regulatory effects of inorganic arsenite (As111) on the activities of GSH-related enzymes were investigated in cultured human keratinocytes. Substantial increases in GR enzyme activity and mRNA levels were shown in keratinocytes and other human cell lines after exposure to low, subtoxic, micromolar concentrations of As111 for 24 h. Upregulation of GSH synthesis paralleled the upregulation of GR as shown by increases in glutamatecysteine lyase (GeL) enzyme activity and mRNA levels, cystine uptake, and intracellular GSH levels. Glutathione S-transferase activity was also shown to increase slightly in keratinocytes, but not in fibroblasts or breast tumor cells. Overall the results show that sublethal arsenic induces a multicomponent response in human keratinocytes that involves upregulation of parts, but not all of the GSH system and counteracts the acute toxic effects of jAs. The upregulation of GR has not previously been shown to be an integral part of this response, although GR is critical for maintaining levels of reduced GSH.

Theranostic multimodular potential of zinc-doped ferrite-saturated metal-binding protein-loaded novel nanocapsules in cancers

The present study successfully developed orally deliverable multimodular zinc (Zn) iron oxide (Fe3O4)-saturated bovine lactoferrin (bLf)-loaded polymeric nanocapsules (NCs), and evaluated their theranostic potential (antitumor efficacy, magnetophotothermal efficacy and imaging capability) in an in vivo human xenograft CpG-island methylator phenotype (CIMP)-1(+)/CIMP2(-)/chromosome instability-positive colonic adenocarcinoma (Caco2) and claudin-low, triple-negative (ER(-)/PR(-)/HER2(-); MDA-MB-231) breast cancer model. Mice fed orally on the Zn-Fe-bLf NC diet showed downregulation in tumor volume and complete regression in tumor volume after 45 days of feeding. In human xenograft colon cancer, vehicle-control NC diet-group (n=5) mice showed a tumor volume of 52.28±11.55 mm(3), and Zn-Fe-bLf NC diet (n=5)-treated mice had a tumor-volume of 0.10±0.073 mm(3). In the human xenograft breast cancer model, Zn-Fe-bLf NC diet (n=5)-treated mice showed a tumor volume of 0.051±0.062 mm(3) within 40 days of feeding. Live mouse imaging conducted by near-infrared fluorescence imaging of Zn-Fe-bLf NCs showed tumor site-specific localization and regression of colon and breast tumor volume. Ex vivo fluorescence-imaging analysis of the vital organs of mice exhibited sparse localization patterns of Zn-Fe-bLf NCs and also confirmed tumor-specific selective localization patterns of Zn-Fe-bLf NCs. Dual imaging using magnetic resonance imaging and computerized tomography scans revealed an unprecedented theranostic ability of the Zn-Fe-bLf NCs. These observations warrant consideration of multimodular Zn-Fe-bLf NCs for real-time cancer imaging and simultaneous cancer-targeted therapy.

Induction of epithelial to mesenchymal transition in PMC42-LA human breast carcinoma cells by carcinoma-associated fibroblast secreted factors

Background
Breast carcinoma is accompanied by changes in the acellular and cellular components of the microenvironment, the latter typified by a switch from fibroblasts to myofibroblasts.


Methods
We utilised conditioned media cultures, Western blot analysis and immunocytochemistry to investigate the differential effects of normal mammary fibroblasts (NMFs) and mammary cancer-associated fibroblasts (CAFs) on the phenotype and behaviour of PMC42-LA breast cancer cells. NMFs were obtained from a mammary gland at reduction mammoplasty, and CAFs from a mammary carcinoma after resection.


Results
We found greater expression of myofibroblastic markers in CAFs than in NMFs. Medium from both CAFs and NMFs induced novel expression of α-smooth muscle actin and cytokeratin-14 in PMC42-LA organoids. However, although conditioned media from NMFs resulted in distribution of vimentin-positive cells to the periphery of PMC42-LA organoids, this was not seen with CAF-conditioned medium. Upregulation of vimentin was accompanied by a mis-localization of E-cadherin, suggesting a loss of adhesive function. This was confirmed by visualizing the change in active β-catenin, localized to the cell junctions in control cells/cells in NMF-conditioned medium, to inactive β-catenin, localized to nuclei and cytoplasm in cells in CAF-conditioned medium.


Conclusion
We found no significant difference between the influences of NMFs and CAFs on PMC42-LA cell proliferation, viability, or apoptosis; significantly, we demonstrated a role for CAFs, but not for NMFs, in increasing the migratory ability of PMC42-LA cells. By concentrating NMF-conditioned media, we demonstrated the presence of factor(s) that induce epithelial-mesenchymal transition in NMF-conditioned media that are present at higher levels in CAF-conditioned media. Our in vitro results are consistent with observations in vivo showing that alterations in stroma influence the phenotype and behaviour of surrounding cells and provide evidence for a role for CAFs in stimulating cancer progression via an epithelial-mesenchymal transition. These findings have implications for our understanding of the roles of signalling between epithelial and stromal cells in the development and progression of mammary carcinoma.

Kernel-based naive bayes classifier for breast cancer prediction

The classification of breast cancer patients is of great importance in cancer diagnosis. Most classical cancer classification methods are clinical-based and have limited diagnostic ability. The recent advances in machine learning technique has made a great impact in cancer diagnosis. In this research, we develop a new algorithm: Kernel-Based Naive Bayes (KBNB) to classify breast cancer tumor based on memography data. The performance of the proposed algorithm is compared with that of classical navie bayes algorithm and kernel-based decision tree algorithm C4.5. The proposed algorithm is found to outperform in the both cases. We recommend the proposed algorithm could be used as a tool to classify the breast patient for early cancer diagnosis.

Psychosocial factors and survival of young women with breast cancer: a population-based prospective cohort study

Purpose: Most women with early-stage breast cancer believe that psychosocial factors are an important influence over whether their cancer will recur. Studies of the issue have produced conflicting results.

Patients and Methods: A population-based sample of 708 Australian women diagnosed before age 60 years with nonmetastatic breast cancer was observed for a median of 8.2 years. Depression and anxiety, coping style, and social support were assessed at a median of 11 months after diagnosis. Hazard ratios for distant disease-free survival (DDFS) and overall survival (OS) associated with psychosocial factors were estimated separately using Cox proportional hazards survival models, with and without adjustment for known prognostic factors.

Results: Distant recurrence occurred in 209 (33%) of 638 assessable patients, and 170 (24%) of 708 patients died during the follow-up period. There were no statistically significant associations between any of the measured psychosocial factors and DDFS or OS from the adjusted analyses. From unadjusted analyses, associations between greater anxious preoccupation and poorer DDFS and OS were observed (P = .02). These associations were no longer evident after adjustment for established prognostic factors; greater anxious preoccupation was associated with younger age at diagnosis (P = .03), higher tumor grade (P = .02), and greater number of involved axillary nodes (P = .008).

Conclusion: The findings do not support the measured psychosocial factors being an important influence on breast cancer outcomes. Interventions for adverse psychosocial factors are warranted to improve quality of life but should not be expected to improve survival.

Low-dose metronomic paclitaxel chemotherapy suppresses breast tumors and metastases in mice

This study investigated the use of low-dose metronomic (LDM) chemotherapy with paclitaxel in a highly metastatic mouse model of 4T1 breast cancers, and compared it with the maximum tolerable dose (MTD) therapy. LDM therapy displayed a stronger anti-tumor activity in suppressing primary and metastatic breast tumors with less degree of side effects, and stronger anti-angiogenic and anti-lymphangiogenic activities than MTD therapy. But MTD therapy showed stronger pro-apoptotic and anti-proliferative activities in situ. Paclitaxel therapy downregulated expression of vascular endothelial growth factor receptor-2 (VEGFR2) and up-regulated expression of thrombospondin-1. The results support the application of paclitaxel LDM therapy to treat advanced breast cancer.

Primary systemic therapy in HER2-amplified breast cancer : a clinical review

Primary systemic therapy (PST) in early breast cancer is utilized in locally advanced breast tumors and when breast-conserving surgery is desirable. In addition, the PST setting provides an opportunity to monitor response including histopathological and biomarker examination of the tumor and host tissues before and after systemic therapy. Trastuzumab is a monoclonal antibody targeting the hEGF receptor that is overexpressed in 15–20% of breast tumors. Trastuzumab is effective in prolonging survival when used to treat women with hEGF receptor overexpressed tumors, both in adjuvant and metastatic disease settings. Trastuzumab has also shown promising activity in PST/neoadjuvant studies by achieving high rates of complete pathologic response. This is a review of clinical studies that incorporated trastuzumab in PST and/or neoadjuvant chemotherapy, including the results of recently reported studies using trastuzumab in combination with other novel therapies such as lapatinib or pertuzumab.

Contribution of fibroblast and mast cell (afferent) and tumor (efferent) IL-6 effects within the tumor microenvironment

Hyperactive inflammatory responses following cancer initiation have led to cancer being described as a ‘wound that never heals’. These inflammatory responses elicit signals via NFκB leading to IL-6 production, and IL-6 in turn has been shown to induce epithelial to mesenchymal transition in breast cancer cells in vitro, implicating a role for this cytokine in cancer cell invasion. We previously have shown that conditioned medium derived from cancer-associated fibroblasts induced an Epithelial to Mesenchymal transition (EMT) in PMC42-LA breast cancer cells and we have now identify IL-6 as present in this medium. We further show that IL-6 is expressed approximately 100 fold higher in a cancer-associated fibroblast line compared to normal fibroblasts. Comparison of mouse-specific (stroma) and human-specific (tumor) IL-6 mRNA expression from MCF-7, MDA MB 468 and MDA MB 231 xenografts also indicated the stroma rather than tumor as a significantly higher source of IL-6 expression. Mast cells (MCs) feature in inflammatory cancer-associated stroma, and activated MCs secrete IL-6. We observed a higher MC index (average number of mast cells per xenograft section/average tumor size) in MDA MB 468 compared to MDA MB 231 xenografts, where all MC were observed to be active (degranulating). This higher MC index correlated with greater mouse-specific IL-6 expression in the MDA MB 468 xenografts, implicating MC as an important source of stromal IL-6. Furthermore, immunohistochemistry on these xenografts for pSTAT3, which lies downstream of the IL-6 receptor indicated frequent correlations between pSTAT3 and mast cell positive cells. Analysis of publically available databases for IL-6 expression in patient tissue revealed higher IL-6 in laser capture microdissected stroma compared to adjacent tissue epithelium from patients with inflammatory breast cancer (IBC) and invasive non-inflammatory breast cancer (non-IBC) and we show that IL-6 expression was significantly higher in Basal versus Luminal molecular/phenotypic groupings of breast cancer cell lines. Finally, we discuss how afferent and efferent IL-6 pathways may participate in a positive feedback cycle to dictate tumor progression.

Is chemotherapy dose intensity adequate in breast cancer management in the Australian healthcare setting: a retrospective analysis

Aim
To determine the adequacy of chemotherapy received dose intensity (RDI) in breast cancer treatment in a general population and to identify factors that influence RDI.

Methods
A retrospective analysis of breast cancer patients who commenced a course of i.v. chemotherapy in 2008 was undertaken. Data were collected on patient and tumor characteristics, chemotherapy regimen, dose (including delays, reductions and the reasons for these), granulocyte colony-stimulating factor (G-CSF) use and febrile neutropenia incidence. RDI was calculated using the planned and actual dose received and time taken. A level of ≥85% RDI was considered acceptable for treatment given with curative intent.

Results
In all, 131 patients (aged 28 to 77 years) received chemotherapy in adjuvant (n = 76, 58%), neoadjuvant (n = 11, 8%) and metastatic settings (n = 44, 34%). RDI did not reach 85% for 12% adjuvant, 36% neoadjuvant and 34% metastatic cases (χ2 = 10.55, P = 0.005). Overall, 43% of patients received G-CSF.

Conclusion
Acceptable chemotherapy RDI was delivered for most patients in the adjuvant setting but not in the neoadjuvant setting. G-CSF treatment contributed to the optimization of dose intensity in the adjuvant setting only. Dose intensity in the metastatic setting was considered satisfactory where quality of life is the primary focus. Other factors can be modified to improve RDI.