Pioneer Valley Life science Institute

Springfield, MA, United States

Pioneer Valley Life science Institute

Springfield, MA, United States
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Zhang M.,Pioneer Valley Life science Institute | Forbes N.S.,University of Massachusetts Amherst
Journal of Controlled Release | Year: 2015

Chemotherapeutics fail to effectively treat tumors because they cannot reach quiescent regions far from blood vessels. Motile Salmonella are an attractive delivery system that could break this therapeutic barrier. However, little is known about the dissemination and tissue penetration of individual bacteria in tumors after intravenous administration. We hypothesized that eliminating the Trg receptor would improve accumulation in tumor quiescence. To test this hypothesis, we deleted the trg gene from nonpathogenic Salmonella. To quantify individual bacterial behavior, we measured tissue penetration in a tumor-on-a-chip device and measured colony localization in mouse tumors using immunofluorescence. In tumors in vitro and in mice, trg- Salmonella penetrated farther into tissue than control bacteria. This difference in localization was caused by the inability to sense sugars in well perfused tissue. Three distinct bacterial phenotypes were observed: proliferating, penetrating, and inactive. Large proliferating colonies, containing more than 40% of individual bacteria, only formed less than 60 μm from blood vessels. Small colonies, in comparison, were present both near (inactive) and far (penetrating) from vessels. The farthest was 361.2 μm from a vessel, demonstrating the ability to target avascular regions. In addition, colonization was most pronounced in poorly vascularized tumor regions. We show that deletion of trg amplifies Salmonella accumulation in quiescent tumor regions, and, for the first time, identify biological processes that control bacterial distribution in tumors. Understanding how Salmonella penetrate tissue, target quiescence and specifically replicate in tumors are essential steps toward creating a tightly controlled, tunable bacterial therapy. © 2014 Elsevier B.V.

Divakaruni A.S.,University of California at San Diego | Wiley S.E.,University of California at San Diego | Rogers G.W.,Seahorse Bioscience, Inc. | Andreyev A.Y.,University of California at San Diego | And 14 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2013

Facilitated pyruvate transport across the mitochondrial inner membrane is a critical step in carbohydrate, amino acid, and lipid metabolism. We report that clinically relevant concentrations of thiazolidinediones (TZDs), a widely used class of insulin sensitizers, acutely and specifically inhibit mitochondrial pyruvate carrier (MPC) activity in a variety of cell types. Respiratory inhibition was overcome with methyl pyruvate, localizing the effect to facilitated pyruvate transport, and knockdown of either paralog, MPC1 or MPC2, decreased the EC50 for respiratory inhibition by TZDs. Acute MPC inhibition significantly enhanced glucose uptake in human skeletal muscle myocytes after 2 h. These data (i) report that clinically used TZDs inhibit theMPC, (ii) validate thatMPC1 andMPC2 are obligatory components of facilitated pyruvate transport in mammalian cells, (iii) indicate that the acute effect of TZDs may be related to insulin sensitization, and (iv) establish mitochondrial pyruvate uptake as a potential therapeutic target for diseases rooted in metabolic dysfunction.

Nguyen D.,New York University | Nguyen D.,Lawrence Berkeley National Laboratory | Oketch-Rabah H.,Lawrence Berkeley National Laboratory | Illa-Bochaca I.,New York University | And 12 more authors.
Cancer Cell | Year: 2011

Tissue microenvironment is an important determinant of carcinogenesis. We demonstrate that ionizing radiation, a known carcinogen, affects cancer frequency and characteristics by acting on the microenvironment. Using a mammary chimera model in which an irradiated host is transplanted with oncogenic Trp53 null epithelium, we show accelerated development of aggressive tumors whose molecular signatures were distinct from tumors arising in nonirradiated hosts. Molecular and genetic approaches show that TGFβ mediated tumor acceleration. Tumor molecular signatures implicated TGFβ, and genetically reducing TGFβ abrogated the effect on latency. Surprisingly, tumors from irradiated hosts were predominantly estrogen receptor negative. This effect was TGFβ independent and linked to mammary stem cell activity. Thus, the irradiated microenvironment affects latency and clinically relevant features of cancer through distinct and unexpected mechanisms. © 2011 Elsevier Inc.

Fagan-Solis K.D.,University of Massachusetts Amherst | Schneider S.S.,Pioneer Valley Life science Institute | Pentecost B.T.,New York State Department of Health | Bentley B.A.,Baystate Medical Center | And 2 more authors.
Journal of Cellular Biochemistry | Year: 2013

Breast cancer is a heterogeneous disease that varies in its biology and response to therapy. A foremost threat to patients is tumor invasion and metastasis, with the greatest risk among patients diagnosed with triple-negative and/or basal-like breast cancers. A greater understanding of the molecular mechanisms underlying cancer cell spreading is needed as 90% of cancer-associated deaths result from metastasis. We previously demonstrated that the Tamoxifen-selected, MCF-7 derivative, TMX2-28, lacks expression of estrogen receptor α (ERα) and is highly invasive, yet maintains an epithelial morphology. The present study was designed to further characterize TMX2-28 cells and elucidate their invasion mechanism. We found that TMX2-28 cells do not express human epidermal growth factor receptor 2 (HER2) and progesterone receptor (PR), in addition to lacking ERα, making the cells triple-negative. We then determined that TMX2-28 cells lack expression of active matrix metalloproteinases (MMPs)-1, MMP-2, MMP-9, and other genes involved in epithelial-mesenchymal transition (EMT) suggesting that TMX2-28 may not utilize mesenchymal invasion. In contrast, TMX2-28 cells have high expression of Ras Homolog Gene Family Member, A (RhoA), a protein known to play a critical role in amoeboid invasion. Blocking RhoA activity with the RhoA pathway specific inhibitor H-1152, or a RhoA specific siRNA, resulted in inhibition of invasive behavior. Collectively, these results suggest that TMX2-28 breast cancer cells exploit a RhoA-dependent, proteolytic-independent invasion mechanism. Targeting the RhoA pathway in triple-negative, basal-like breast cancers that have a proteolytic-independent invasion mechanism may provide therapeutic strategies for the treatment of patients with increased risk of metastasis. J. Cell. Biochem. 114: 1385-1394, 2013. © 2013 Wiley Periodicals, Inc. Copyright © 2013 Wiley Periodicals, Inc.

McRae Page S.,University of Massachusetts Amherst | Henchey E.,Pioneer Valley Life science Institute | Chen X.,University of Massachusetts Amherst | Schneider S.,Pioneer Valley Life science Institute | Emrick T.,University of Massachusetts Amherst
Molecular Pharmaceutics | Year: 2014

We report the in vivo efficacy, in tumor-bearing mice, of cancer prodrugs consisting of poly(methacryloyloxyethyl phosphorylcholine) (polyMPC) conjugated to doxorubicin (DOX). Our synthesis of polyMPC-DOX conjugates established prodrugs with tunable drug loading, pH sensitive release kinetics, and a maximum tolerated dose in the range of 30-50 mg/kg (DOX equivalent) in healthy mice. Here we show prolonged circulation of polyMPC-DOX, with a measured in vivo half-life (t1/2) 8 times greater than that of the free drug. We observed reduced drug uptake in healthy tissue, and 2-3 times enhanced drug accumulation in tumors for polyMPC-DOX prodrugs compared to free DOX, using BALB/c mice bearing 4T1 tumors. Prolonged survival and reduced tumor growth were observed in mice receiving the polyMPC-DOX prodrug treatment. Moreover, we evaluated immunogenicity of polyMPC-DOX prodrugs by examining complete blood count (CBC) and characteristic cytokine responses, demonstrating no apparent innate or adaptive immune system response. © 2014 American Chemical Society.

Blackburn A.C.,Australian National University | Jerry D.J.,Pioneer Valley Life science Institute | Jerry D.J.,University of Massachusetts Amherst
Journal of Mammary Gland Biology and Neoplasia | Year: 2011

Genetic factors play an important role in determining risk and resistance to increased breast cancer. Recent technological advances have made it possible to analyze hundreds of thousands of single nucleotide polymorphisms in large-scale association studies in humans and have resulted in identification of alleles in over 20 genes that influence breast cancer risk. Despite these advances, the challenge remains in identifying what the functional polymorphisms are that confer the increased risk, and how these genetic variants interact with each other and with environmental factors. In rodents, the incidence of mammary tumors varies among strains, such that they can provide alternate ideas for candidate pathways involved in humans. Mapping studies in animals have unearthed numerous loci for breast cancer susceptibility that have been validated in human populations. In a reciprocal manner, knockin and knockout mice have been used to validate the tumorigenicity of risk alleles found in population studies. Rodent studies also underscore the complexity of interactions among alleles. The fact that genes affecting risk and resistance to mammary tumors in rodents depend greatly upon the carcinogenic challenge emphasizes the importance of gene x environment interactions. The challenge to rodent geneticists now is to capitalize on the ability to control the genetics and environment in rodent models of tumorigenesis to better understand the biology of breast cancer development, to identify those polymorphisms most relevant to human susceptibility and to identify compensatory pathways that can be targeted for improved prevention in women at highest risk of developing breast cancer. © 2011 Springer Science+Business Media, LLC.

Tao L.,University of Massachusetts Amherst | Roberts A.L.,University of Massachusetts Amherst | Dunphy K.A.,University of Massachusetts Amherst | Dunphy K.A.,Pioneer Valley Life science Institute | And 4 more authors.
Stem Cells | Year: 2011

Breast cancer is the most common tumor among women with inherited mutations in the p53 gene (Li-Fraumeni syndrome). The tumors represent the basal-like subtype, which has been suggested to originate from mammary stem/progenitor cells. In mouse mammary epithelium, mammosphere-forming potential was increased with decreased dosage of the gene encoding the p53 tumor suppressor protein (Trp53). Limiting dilution transplantation also showed a 3.3-fold increase in the frequency of longterm regenerative mammary stem cells in Trp53-/- mice. The repression of mammospheres by p53 was apparent despite the absence of apoptotic responses to radiation indicating a dissociation of these two activities of p53. The effects of p53 on progenitor cells were also observed in TM40A cells using both mammosphere-forming assays and the DsRed-let7c-sensor. The frequency of long-term label-retaining epithelial cells was decreased in Trp53-/-mammary glands indicating that asymmetric segregation of DNA is diminished and contributes to the expansion of the mammary stem cells. Treatment with an inhibitor of γ-secretase (N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S- phenylglycine t-butyl ester) reduced the number of Trp53-/-mammospheres to the level found in Trp53+/+ cells. These results demonstrate that basal levels of p53 restrict mammary stem/progenitor cells through Notch and that the Notch pathway is a therapeutic target to prevent expansion of this vulnerable pool of cells. © AlphaMed Press.

Faibish M.,University of Massachusetts Amherst | Francescone R.,University of Massachusetts Amherst | Bentley B.,Pioneer Valley Life science Institute | Yan W.,University of Massachusetts Amherst | And 2 more authors.
Molecular Cancer Therapeutics | Year: 2011

Accumulating evidence has indicated that expression levels of YKL-40, a secreted glycoprotein, were elevated in multiple advanced human cancers. Recently, we have identified an angiogenic role of YKL-40 in cancer development. However, blockade of the function of YKL-40, which implicates therapeutic value, has not been explored yet. Our current study sought to establish a monoclonal anti-YKL-40 antibody as a neutralizing antibody for the purpose of blocking tumor angiogenesis and metastasis. A mouse monoclonal anti-YKL-40 antibody (mAY) exhibited specific binding with recombinant YKL-40 and with YKL-40 secreted from osteoblastoma cells MG-63 and brain tumor cells U87. In the functional analysis, we found that mAY inhibited tube formation of microvascular endothelial cells in Matrigel induced by conditioned medium of MG-63 and U87 cells, as well as recombinant YKL-40. mAY also abolished YKL-40-induced activation of the membrane receptor VEGF receptor 2 (Flk-1/KDR) and intracellular signaling mitogen-activated protein (MAP) kinase extracellular signal-regulated kinase (Erk) 1 and Erk 2. In addition, mAY enhanced cell death response of U87 line to g-irradiation through decreased expression of pAKT and AKT and accordingly, abrogated angiogenesis induced by the conditioned medium of U87 cells in which YKL-40 levels were elevated by treatment with g-irradiation. Furthermore, treatment of xenografted tumor mice with mAY restrained tumor growth, angiogenesis, and progression. Taken together, this study has shown the therapeutic use for the mAY in treatment of tumor angiogenesis and metastasis. ©2011 AACR.

Chen X.,University of Massachusetts Amherst | Parelkar S.S.,University of Massachusetts Amherst | Henchey E.,Pioneer Valley Life science Institute | Schneider S.,Pioneer Valley Life science Institute | Emrick T.,University of Massachusetts Amherst
Bioconjugate Chemistry | Year: 2012

We demonstrate the conjugation of the cancer drug doxorubicin (DOX) to poly(methacryloyloxyethyl phosphorylcholine) (polyMPC), linked by hydrazone groups, using (1) a one-pot ATRP/click sequence, and (2) a post-polymerization conjugation strategy. While the one-pot method gave polyMPC-DOX conjugates in a facile single step, post-polymerization conjugation gave higher-molecular-weight polymers with very high DOX loadings. DOX release from the polyMPC backbone was pH-dependent (faster at pH 5.0 than at pH 7.4) owing to the hydrazone linkage. Half-life values of DOX release ranged from 2 to 40 h at pH 5.0. Cell culture experiments showed that highly loaded polyMPC-DOX conjugates exhibited higher intracellular drug accumulation and lower half-maximal inhibitory concentration (IC50) values, while a polymer with 30 wt % drug loading showed a maximum tolerated dose in the range of 30-50 mg/kg DOX equivalent weight in healthy mice. © 2012 American Chemical Society.

Sun X.,University of North Carolina at Chapel Hill | Casbas-Hernandez P.,University of North Carolina at Chapel Hill | Bigelow C.,University of Massachusetts Amherst | Makowski L.,University of North Carolina at Chapel Hill | And 4 more authors.
Breast Cancer Research and Treatment | Year: 2012

Activation of inflammatory pathways is one plausible mechanism underlying the association between obesity and increased breast cancer risk. However, macrophage infiltration and local biomarkers of inflammation in breast adipose tissue have seldom been studied in association with obesity. Gene expression profiles of normal breast tissue from reduction mammoplasty patients were evaluated by whole genome microarrays to identify patterns associated with obesity status (normal-weight, body mass index (BMI) <25; overweight, BMI 25-29.9; obese, BMI ≤30). The presence of macrophage-enriched inflammatory loci with immunopositivity for CD68 protein was evaluated by immunohistochemistry (IHC). After adjusting for confounding by age, 760 genes were differentially expressed (203 up and 557 down; FDR = 0.026) between normal-weight and obese women. Gene ontology analysis suggested significant enrichment for pathways involving IL-6, IL-8, CCR5 signaling in macrophages and RXRα and PPARα activation, consistent with a pro-inflammatory state and suggestive of macrophage infiltration. Gene set enrichment analysis also demonstrated that the genomic signatures of monocytes and macrophages were over-represented in the obese group with FDR of 0.08 and 0.13, respectively. Increased macrophage infiltration was confirmed by IHC, which showed that the breast adipose tissue of obese women had higher average macrophage counts (mean = 8.96 vs. 3.56 in normal-weight women) and inflammatory foci counts (mean = 4.91 vs. 2.67 in normal-weight women). Obesity is associated with local inflammation and macrophage infiltration in normal human breast adipose tissues. Given the role of macrophages in carcinogenesis, these findings have important implications for breast cancer etiology and progression. © 2011 Springer Science+Business Media, LLC.

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