Search tips
Search criteria

Results 1-25 (124)

Clipboard (0)

Select a Filter Below

more »
Year of Publication
more »
1.  Feasibility outcomes of a presurgical randomized controlled trial exploring the impact of caloric restriction and increased physical activity versus a wait-list control on tumor characteristics and circulating biomarkers in men electing prostatectomy for prostate cancer 
BMC Cancer  2016;16:61.
Obesity is associated with tumor aggressiveness and disease-specific mortality for more than 15 defined malignancies, including prostate cancer. Preclinical studies suggest that weight loss from caloric restriction and increased physical activity may suppress hormonal, energy-sensing, and inflammatory factors that drive neoplastic progression; however, exact mechanisms are yet to be determined, and experiments in humans are limited.
We conducted a randomized controlled trial among 40 overweight or obese, newly-diagnosed prostate cancer patients who elected prostatectomy to explore feasibility of a presurgical weight loss intervention that promoted a weight loss of roughly one kg. week−1 via caloric restriction and physical activity, as well as to assess effects on tumor biology and circulating biomarkers. Measures of feasibility (accrual, retention, adherence, and safety) were primary endpoints. Exploratory aims were directed at the intervention’s effect on tumor proliferation (Ki-67) and other tumor markers (activated caspase-3, insulin and androgen receptors, VEGF, TNFβ, NFκB, and 4E-BP1), circulating biomarkers (PSA, insulin, glucose, VEGF, TNFβ, leptin, SHBG, and testosterone), lymphocytic gene expression of corresponding factors and cellular bioenergetics in neutrophils, and effects on the gut microbiome. Consenting patients were randomized in a 1:1 ratio to either: 1) weight loss via a healthful, guidelines-based diet and exercise regimen; or 2) a wait-list control. While biological testing is currently ongoing, this paper details our methods and feasibility outcomes.
The accrual target was met after screening 101 cases (enrollment rate: 39.6 %). Other outcomes included a retention rate of 85 %, excellent adherence (95 %), and no serious reported adverse events. No significant differences by age, race, or weight status were noted between enrollees vs. non-enrollees. The most common reasons for non-participation were “too busy” (30 %), medical exclusions (21 %), and “distance” (16 %).
Presurgical trials offer a means to study the impact of diet and exercise interventions directly on tumor tissue, and other host factors that are feasible and safe, though modifications are needed to conduct trials within an abbreviated period of time and via distance medicine-based approaches. Pre-surgical trials are critical to elucidate the impact of lifestyle interventions on specific mechanisms that mediate carcinogenesis and which can be used subsequently as therapeutic targets.
Trial registration
PMCID: PMC4743419  PMID: 26850040
Prostatic neoplasms; Diet; Physical activity; Exercise; Weight loss; Obesity; Intervention; Presurgical
2.  Tumor specific liposomes improve detection of pancreatic adenocarcinoma in vivo using optoacoustic tomography 
Pancreatic cancer often goes undiagnosed until late stage disease due in part to suboptimal early detection. Our goal was to develop a Syndecan-1 tagged liposome containing fluorescent dye as an improved contrast agent for detection of pancreatic adenocarcinoma in vivo using multispectral optoacoustic tomography.
The diagnostic capabilities and specificity to pancreatic adenocarcinoma of Syndecan-1 targeted liposomes were evaluated both in vitro and in vivo. Immunocytochemistry showed that liposomes preferentially bound to and released their contents into cells expressing high levels of insulin-like growth factor 1 receptor. We determined that the contents of the liposome were released into the cell as noted by the change in propidium iodide fluorescence from green to red based upon nucleic acid binding. In an orthotopic mouse model, the liposomes preferentially targeted the pancreatic tumor with little off-target binding in the liver and spleen. Peak accumulation of the liposomes in the tumor occurred at 8 h post-injection. Multispectral optoacoustic tomographic imaging was able to provide high-resolution 3D images of the tumor and liposome location. Ex vivo analysis showed that non-targeted liposomes accumulated in the liver, suggesting that specificity of the liposomes for pancreatic adenocarcinoma was due to the presence of the Syndecan-1 ligand.
This study demonstrated that Syndecan-1 liposomes were able to release cargo into IGF1-R expressing tumor cells. The Syndecan-1 liposomes demonstrated tumor specificity in orthotopic pancreatic cancer as observed using multispectral optoacoustic tomography with reduced kidney and liver uptake. By targeting the liposome with Syndecan-1, this nanovehicle has potential as a targeted theranostic nanoparticle for both drug and contrast agent delivery to pancreatic tumors.
Electronic supplementary material
The online version of this article (doi:10.1186/s12951-015-0139-8) contains supplementary material, which is available to authorized users.
PMCID: PMC4665906  PMID: 26627455
3.  An Autoregulatory Mechanism Governing Mucociliary Transport Is Sensitive to Mucus Load 
Mucociliary clearance, characterized by mucus secretion and its conveyance by ciliary action, is a fundamental physiological process that plays an important role in host defense. Although it is known that ciliary activity changes with chemical and mechanical stimuli, the autoregulatory mechanisms that govern ciliary activity and mucus transport in response to normal and pathophysiological variations in mucus are not clear. We have developed a high-speed, 1-μm-resolution, cross-sectional imaging modality, termed micro-optical coherence tomography (μOCT), which provides the first integrated view of the functional microanatomy of the epithelial surface. We monitored invasion of the periciliary liquid (PCL) layer by mucus in fully differentiated human bronchial epithelial cultures and full thickness swine trachea using μOCT. We further monitored mucociliary transport (MCT) and intracellular calcium concentration simultaneously during invasion of the PCL layer by mucus using colocalized μOCT and confocal fluorescence microscopy in cell cultures. Ciliary beating and mucus transport are up-regulated via a calcium-dependent pathway when mucus causes a reduction in the PCL layer and cilia height. When the load exceeds a physiological limit of approximately 2 μm, this gravity-independent autoregulatory mechanism can no longer compensate, resulting in diminished ciliary motion and abrogation of stimulated MCT. A fundamental integrated mechanism with specific operating limits governs MCT in the lung and fails when periciliary layer compression and mucus viscosity exceeds normal physiologic limits.
PMCID: PMC4189485  PMID: 24937762
cilia; micro-optical coherence tomography; intracellular calcium; mucociliary transport
4.  High Throughput Kinomic Profiling of Human Clear Cell Renal Cell Carcinoma Identifies Kinase Activity Dependent Molecular Subtypes 
PLoS ONE  2015;10(9):e0139267.
Despite the widespread use of kinase-targeted agents in clear cell renal cell carcinoma (CC-RCC), comprehensive kinase activity evaluation (kinomic profiling) of these tumors is lacking. Thus, kinomic profiling of CC-RCC may assist in devising a classification system associated with clinical outcomes, and help identify potential therapeutic targets. Fresh frozen CC-RCC tumor lysates from 41 clinically annotated patients who had localized disease at diagnosis were kinomically profiled using the PamStation®12 high-content phospho-peptide substrate microarray system (PamGene International). Twelve of these patients also had matched normal kidneys available that were also profiled. Unsupervised hierarchical clustering and supervised comparisons based on tumor vs. normal kidney and clinical outcome (tumor recurrence) were performed and coupled with advanced network modeling and upstream kinase prediction methods. Unsupervised clustering analysis of localized CC-RCC tumors identified 3 major kinomic groups associated with inflammation (A), translation initiation (B), and immune response and cell adhesions (C) processes. Potential driver kinases implicated include PFTAIRE (PFTK1), PKG1, and SRC, which were identified in groups A, B, and C, respectively. Of the 9 patients who had tumor recurrence, only one was found in Group B. Supervised analysis showed decreased kinase activity of CDK1 and RSK1-4 substrates in those which progressed compared to others. Twelve tumors with matching normal renal tissue implicated increased PIM’s and MAPKAPK’s in tumors compared to adjacent normal renal tissue. As such, comprehensive kinase profiling of CC-RCC tumors could provide a functional classification strategy for patients with localized disease and identify potential therapeutic targets.
PMCID: PMC4583516  PMID: 26406598
5.  Phosphodiesterase 10A: a novel target for selective inhibition of colon tumor cell growth and β-catenin-dependent TCF transcriptional activity 
Oncogene  2014;34(12):1499-1509.
The cyclic nucleotide phosphodiesterase10A (PDE10) has been mostly studied as a therapeutic target for certain psychiatric and neurological conditions, although a potential role in tumorigenesis has not been reported. Here we show that PDE10 is elevated in human colon tumor cell lines compared with normal colonocytes, as well as in colon tumors from human clinical specimens and intestinal tumors from ApcMin/+ mice compared with normal intestinal mucosa, respectively. An isozyme and tumor-selective role of PDE10 was evident by the ability of small molecule inhibitors and siRNA knockdown to suppress colon tumor cell growth with reduced sensitivity of normal colonocytes. Stable knockdown of PDE10 by shRNA also inhibits colony formation and increases doubling time of colon tumor cells. PDE10 inhibition selectively activates cGMP/PKG signaling to suppress β-catenin levels and T-cell factor (TCF) transcriptional activity in colon tumor cells. Conversely, ectopic expression of PDE10 in normal and precancerous colonocytes increases proliferation and activates TCF transcriptional activity. These observations suggest a novel role of PDE10 in colon tumorigenesis and that inhibitors may be useful for the treatment or prevention of colorectal cancer.
PMCID: PMC4212019  PMID: 24704829
colorectal cancer; phosphodiesterase 10; cGMP; PKG; β-catenin
6.  Retargeting of Gene Expression Using Endothelium Specific Hexon Modified Adenoviral Vector 
Virology  2013;447(0):312-325.
Adenovirus serotype 5 (Ad5) vectors are well suited for gene therapy. However, tissue-selective transduction by systemically administered Ad5-based vectors is confounded by viral particle sequestration in the liver. Hexon-modified Ad5 expressing reporter gene under transcriptional control by the immediate/early cytomegalovirus (CMV) or the Roundabout 4 receptor (Robo4) enhancer/promoter were characterized by growth in cell culture, stability in vitro, gene transfer in the presence of human coagulation factor X, and biodistribution in mice. The obtained data demonstrate the utility of the Robo4 promoter in an Ad5 vector context. Substitution of the hypervariable region 7 (HVR7) of the Ad5 hexon with HVR7 from Ad serotype 3 resulted in decreased liver tropism and dramatically altered biodistribution of gene expression. The results of these studies suggest that the combination of liver detargeting using a genetic modification of hexon with an endothelium-specific transcriptional control element produces an additive effect in the improvement of Ad5 biodistribution.
PMCID: PMC3894856  PMID: 24210128
adenovirus; targeting; endothelium; Roundabout 4 promoter; hexon
7.  A Functional Anatomic Defect of the Cystic Fibrosis Airway 
Rationale: The mechanisms underlying cystic fibrosis (CF) lung disease pathogenesis are unknown.
Objectives: To establish mechanisms linking anion transport with the functional microanatomy, we evaluated normal and CF piglet trachea as well as adult swine trachea in the presence of selective anion inhibitors.
Methods: We investigated airway functional microanatomy using microoptical coherence tomography, a new imaging modality that concurrently quantifies multiple functional parameters of airway epithelium in a colocalized fashion.
Measurements and Main Results: Tracheal explants from wild-type swine demonstrated a direct link between periciliary liquid (PCL) hydration and mucociliary transport (MCT) rates, a relationship frequently invoked but never experimentally confirmed. However, in CF airways this relationship was completely disrupted, with greater PCL depths associated with slowest transport rates. This disrupted relationship was recapitulated by selectively inhibiting bicarbonate transport in vitro and ex vivo. CF mucus exhibited increased viscosity in situ due to the absence of bicarbonate transport, explaining defective MCT that occurs even in the presence of adequate PCL hydration.
Conclusions: An inherent defect in CF airway surface liquid contributes to delayed MCT beyond that caused by airway dehydration alone and identifies a fundamental mechanism underlying the pathogenesis of CF lung disease in the absence of antecedent infection or inflammation.
PMCID: PMC4214131  PMID: 25029666
cystic fibrosis; airway epithelium; optical coherence tomography; mucus transport; viscosity
8.  Clinical Implications of Rabphillin-3A-Like Gene Alterations in Breast Cancer 
PLoS ONE  2015;10(6):e0129216.
For the rabphillin-3A-like (RPH3AL) gene, a putative tumor suppressor, the clinical significance of genetic alterations in breast cancers was evaluated. DNA and RNA were extracted from formalin-fixed, paraffin-embedded (FFPE) cancers and matching normal tissues. DNA samples were assessed for loss of heterozygosity (LOH) at the 17p13.3 locus of RPH3AL and the 17p13.1 locus of the tumor suppressor, TP53. RPH3AL was sequenced, and single nucleotide polymorphisms (SNPs) were genotyped. RNA samples were evaluated for expression of RPH3AL, and FFPE tissues were profiled for its phenotypic expression. Alterations in RPH3AL were correlated with clinicopathological features, LOH of TP53, and patient survival. Of 121 cancers, 80 had LOH at one of the RPH3AL locus. LOH of RHP3AL was associated with nodal metastasis, advanced stage, large tumor size, and poor survival. Although ~50% were positive for LOH at the RPH3AL and TP53 loci, 19 of 105 exhibited LOH only at the RPH3AL locus. Of these, 12 were non-Hispanic Caucasians (Whites), 15 had large tumors, and 12 were older (>50 years). Patients exhibiting LOH at both loci had shorter survival than those without LOH at these loci (log-rank, P = 0.014). LOH at the TP53 locus alone was not associated with survival. Analyses of RPH3AL identified missense point mutations in 19 of 125 cases, a SNP (C>A) in the 5’untranslated region at -25 (5’UTR-25) in 26 of 104, and a SNP (G>T) in the intronic region at 43 bp downstream to exon-6 (intron-6-43) in 79 of 118. Genotype C/A or A/A of the SNP at 5’UTR-25 and genotype T/T of a SNP at intron-6-43 were predominantly in Whites. Low levels of RNA and protein expression of RPH3AL were present in cancers relative to normal tissues. Thus, genetic alterations in RPH3AL are associated with aggressive behavior of breast cancers and with short survival of patients.
PMCID: PMC4466565  PMID: 26070152
9.  Effect of niclosamide on basal-like breast cancers 
Molecular cancer therapeutics  2014;13(4):800-811.
Basal-like breast cancers (BLBCs) are poorly differentiated and display aggressive clinical behavior. These tumors become resistant to cytotoxic agents and tumor relapse has been attributed to the presence of cancer stem cells (CSCs). One of the pathways involved in CSC regulation is the Wnt/β-catenin signaling pathway. LRP6, a Wnt ligand receptor, is one of the critical elements of this pathway and could potentially be an excellent therapeutic target. Niclosamide has been shown to inhibit the Wnt/β-catenin signaling pathway by causing degradation of LRP6. TRA-8, a monoclonal antibody specific to TRAIL death receptor 5, is cytotoxic to BLBC cell lines and their CSC enriched populations. The goal of this study was to examine whether niclosamide is cytotoxic to BLBCs, specifically the CSC population, and if in combination with TRA-8 could produce increased cytotoxicity. Aldehyde dehydrogenase (ALDH) is a known marker of CSCs. By testing BLBC cells for ALDH expression by flow cytometry, we were able to isolate a non-adherent population of cells that have high ALDH expression. Niclosamide showed cytotoxicity against these non-adherent ALDH expressing cells in addition to adherent cells from four BLBC cell lines: 2LMP, SUM159, HCC1187 and HCC1143. Niclosamide produced reduced levels of LRP6 and β-catenin, which is a downstream Wnt/β-catenin signaling protein. The combination of TRA-8 and niclosamide produced additive cytotoxicity and a reduction in Wnt/β-catenin activity. Niclosamide in combination with TRA-8 suppressed growth of 2LMP orthotopic tumor xenografts. These results suggest that niclosamide or congeners of this agent may be useful for the treatment of BLBC.
PMCID: PMC3981919  PMID: 24552774
TRA-8; Tigatuzumab; Death Receptor 5; Basal-like Breast Cancer; Cancer Stem Cells; Tumor Initiating Cells; LRP6; Wnt/β-catenin; Niclosamide (Niclocide)
10.  l-Methionine inhibits growth of human pancreatic cancer cells 
Anti-cancer drugs  2014;25(2):200-203.
We have previously shown that l-methionine inhibits proliferation of breast, prostate, and colon cancer cells. This study extends these findings to BXPC-3 (mutated p53) and HPAC (wild-type p53) pancreatic cancer cells and explores the reversibility of these effects. Cells were exposed to l-methionine (5 mg/ml) for 7 days or for 3 days, followed by 4 days of culture without l-methionine (recovery). Cell proliferation, apoptosis, and cell cycle effects were assessed by flow cytometry after staining for Ki-67 or annexin V/propidium iodide. Cell proliferation was reduced by 31–35% after 7 days of methionine exposure; the effect persisted in BXPC-3 and HPAC cells after 4 days of recovery. Methionine increased apoptosis by 40–75% in HPAC cells, but not in BXPC-3 cells. Continuous exposure to methionine caused accumulation of BXPC-3 cells in the S phase and HPAC cells in both the G0/G1 and S phases; however, after 4 days of recovery, these effects disappeared. In conclusion, l-methionine inhibits proliferation and interferes with the cell cycle of BXPC-3 and HPAC pancreatic cancer cells; the effects on apoptosis remarkably persisted after methionine withdrawal. Apoptosis was induced only in BXPC-3 cells. Some of the differences in the effects of methionine between cell lines may be related to disparate p53 status. These findings warrant further studies on the potential therapeutic benefit of l-methionine against pancreatic cancer.
PMCID: PMC4346324  PMID: 24126240
BXPC-3 cells; HPAC cells; methionine; p53; pancreatic cancer cells
11.  NSAIDs inhibit tumorigenesis, but how? 
Numerous epidemiological studies have reported that the long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with a significant decrease in cancer incidence and delayed progression of malignant disease. The use of NSAIDs has also been linked with reduced risk from cancer-related mortality and distant metastasis. Certain prescription strength NSAIDs, such as sulindac, have been shown to cause regression of precancerous lesions. Unfortunately, the extended use of NSAIDs for chemoprevention results in potentially fatal side effects related to their cyclooxygenase (COX)-inhibitory activity and suppression of prostaglandin synthesis. While the basis for the tumor growth-inhibitory activity of NSAIDs likely involves multiple effects on tumor cells and their microenvironment, numerous investigators have concluded that the underlying mechanism is not completely explained by COX inhibition. It may therefore be possible to develop safer and more efficacious drugs by targeting such COX-independent mechanisms. NSAID derivatives or metabolites that lack COX-inhibitory activity, but retain or have improved anticancer activity support this possibility. Experimental studies suggest that apoptosis induction and suppression of β-catenin-dependent transcription are important aspects of their antineoplastic activity. Studies show that the latter involves phosphodiesterase inhibition and the elevation of intracellular cyclic GMP levels. Here, we review the evidence for COX-independent mechanisms and discuss progress towards identifying alternative targets and developing NSAID derivatives that lack COX-inhibitory activity but have improved antineoplastic properties.
PMCID: PMC3947450  PMID: 24311630
Chemoprevention; NSAIDs; sulindac; colorectal cancer
12.  Vascular Endothelial Growth Factor Reduces Tamoxifen Efficacy and Promotes Metastatic Colonization and Desmoplasia in Breast Tumors 
Cancer research  2008;68(15):6232-6240.
Clinical studies have shown that decreased tamoxifen effectiveness correlates with elevated levels of vascular endothelial growth factor (VEGF)-A165 in biopsy samples of breast cancers. To investigate the mechanisms underlying tamoxifen resistance and metastasis, we engineered the estrogen receptor (ER)–positive MCF-7 human breast cancer cell line to express VEGF to clinically relevant levels in a doxycycline-regulated manner. Induction of VEGF expression in orthotopically implanted xenografts that were initially tamoxifen responsive and noninvasive resulted in tamoxifen-resistant tumor growth and metastasis to the lungs. Lung metastases were also observed in a VEGF-dependent manner following tail vein injection of tumor cells. At both primary and metastatic sites, VEGF-overexpressing tumors exhibited extensive fibroblastic stromal content, a clinical feature called desmoplasia. VEGF-induced metastatic colonies were surrounded by densely packed stromal cells before detectable angiogenesis, suggesting that VEGF is involved in the initiation of desmoplasia. Because expression of VEGF receptors R1 and R2 was undetectable in these tumor cells, the observed VEGF effects on reduction of tamoxifen efficacy and metastatic colonization are most likely mediated by paracrine signaling that enhances tumor/stromal cell interactions and increases the level of desmoplasia. This study reveals new roles for VEGF in breast cancer progression and suggests that combination of antiestrogens and VEGF inhibitors may prolong tamoxifen sensitivity and prevent metastasis in patients with ER-positive tumors.
PMCID: PMC4337242  PMID: 18676847
13.  Human PDE4A8, a novel brain-expressed PDE4 cAMP-specific phosphodiesterase that has undergone rapid evolutionary change 
The Biochemical journal  2008;411(2):361-369.
We have isolated cDNAs encoding PDE4A8 (phosphodiesterase 4 isoform A8), a new human cAMP-specific PDE4 isoform encoded by the PDE4A gene. PDE4A8 has a novel N-terminal region of 85 amino acids that differs from those of the related ‘long’ PDE4A4, PDE4A10 and PDE4A11 isoforms. The human PDE4A8 N-terminal region has diverged substantially from the corresponding isoforms in the rat and other mammals, consistent with rapid evolutionary change in this region of the protein. When expressed in COS-7 cells, PDE4A8 localized predominantly in the cytosol, but approx. 20% of the enzyme was associated with membrane fractions. Cytosolic PDE4A8 was exquisitely sensitive to inhibition by the prototypical PDE4 inhibitor rolipram (IC50 of 11 ± 1 nM compared with 1600 nM for PDE4A4), but was less sensitive to inhibition by cilomilast (IC50 of 101 ± 7 nM compared with 61 nM for PDE4A4). PDE4A8 mRNA was found to be expressed predominantly in skeletal muscle and brain, a pattern that differs from the tissue expression of other human PDE4 isoforms and also from that of rat PDE4A8. Immunohistochemical analysis showed that PDE4A8 could be detected in discrete regions of human brain, including the cerebellum, spinal cord and cerebral cortex. The unique tissue distribution of PDE4A8, combined with the evolutionary divergence of its N-terminus, suggest that this isoform may have a specific function in regulating cAMP levels in human skeletal muscle and brain.
PMCID: PMC4337886  PMID: 18095939
alternative mRNA splicing; cAMP; cilomilast; phosphodiesterase 4 isoform A (PDE4A); phosphoric diester hydrolyase; rolipram
14.  SELDI-TOF MS Whole Serum Proteomic Profiling with IMAC Surface Does Not Reliably Detect Prostate Cancer 
Clinical chemistry  2007;54(1):53-60.
The analysis of bodily fluids using SELDI-TOF MS has been reported to identify signatures of spectral peaks that can be used to differentiate patients with a specific disease from normal or control patients. This report is the 2nd of 2 companion articles describing a validation study of a SELDI-TOF MS approach with IMAC surface sample processing to identify prostatic adenocarcinoma.
We sought to derive a decision algorithm for classification of prostate cancer from SELDI-TOF MS spectral data from a new retrospective sample cohort of 400 specimens. This new cohort was selected to minimize possible confounders identified in the previous study described in the companion paper.
The resulting new classifier failed to separate patients with prostate cancer from biopsy-negative controls; nor did it separate patients with prostate cancer with Gleason scores <7 from those with Gleason scores ≥7.
In this, the 2nd stage of our planned validation process, the SELDI-TOF MS– based protein expression profiling approach did not perform well enough to advance to the 3rd (prospective study) stage. We conclude that the results from our previous studies—in which differentiation between prostate cancer and noncancer was demonstrated—are not generalizable. Earlier study samples likely had biases in sample selection that upon removal, as in the present study, resulted in inability of the technique to discriminate cancer from non-cancer cases.
PMCID: PMC4332515  PMID: 18024530
15.  Effect of exercise and calorie restriction on biomarkers of aging in mice 
Unlike, calorie restriction, exercise fails to extend maximum life span, but the mechanisms that explain this disparate effect are unknown. We used a 24-wk protocol of treadmill running, weight matching, and pair feeding to compare the effects of exercise and calorie restriction on biomarkers related to aging. This study consisted of young controls, an ad libitum-fed sedentary group, two groups that were weight matched by exercise or 9% calorie restriction, and two groups that were weight matched by 9% calorie restriction + exercise or 18% calorie restriction. After 24 wk, ad libitum-fed sedentary mice were the heaviest and fattest. When weight-matched groups were compared, mice that exercised were leaner than calorie-restricted mice. Ad libitum-fed exercise mice tended to have lower serum IGF-1 than fully-fed controls, but no difference in fasting insulin. Mice that underwent 9% calorie restriction or 9% calorie restriction + exercise, had lower insulin levels; the lowest concentrations of serum insulin and IGF-1 were observed in 18% calorie-restricted mice. Exercise resulted in elevated levels of tissue heat shock proteins, but did not accelerate the accumulation of oxidative damage. Thus, failure of exercise to slow aging in previous studies is not likely the result of increased accrual of oxidative damage and may instead be due to an inability to fully mimic the hormonal and/or metabolic response to calorie restriction.
PMCID: PMC4332519  PMID: 18321952
energetics; obesity; energy balance
16.  S100A4 promotes pancreatic cancer progression through a dual signaling pathway mediated by Src and focal adhesion kinase 
Scientific Reports  2015;5:8453.
S100A4 expression is associated with poor clinical outcomes of patients with pancreatic cancer. The effects of loss or gain of S100A4 were examined in pancreatic cancer cell lines. S100A4 downregulation remarkably reduces cell migration and invasion, inhibits proliferation, and induces apoptosis in pancreatic tumor cells. S100A4 downregulation results in significant cell growth inhibition and apoptosis in response to TGF-β1, supporting a non-canonical role of S100A4 in pancreatic cancer. The role of S100A4 in tumor progression was studied by using an orthotopic human pancreatic cancer xenograft mouse model. Tumor mass is remarkably decreased in animals injected with S100A4-deficient pancreatic tumor cells. P27Kip1 expression and cleaved caspase-3 are increased, while cyclin E expression is decreased, in S100A4-deficient pancreatic tumors in vivo. S100A4-deficient tumors have lower expression of vascular endothelial growth factor, suggesting reduced angiogenesis. Biochemical assays revealed that S100A4 activates Src and focal adhesion kinase (FAK) signaling events, and inhibition of both kinases is required to maximally block the tumorigenic potential of pancreatic cancer cells. These findings support that S100A4 plays an important role in pancreatic cancer progression in vivo and S100A4 promotes tumorigenic phenotypes of pancreatic cancer cells through the Src-FAK mediated dual signaling pathway.
PMCID: PMC4326725  PMID: 25677816
17.  Thymus Exosomes-Like Particles Induce Regulatory T Cells1 
Exosomes released from different types of cells have been proposed to contribute to intercellular communication. We report that thymic exosome-like particles (ELPs) released from cells of the thymus can induce the development of Foxp3+ regulatory T (Treg) cells in the lung and liver. Thymic ELPs also induce the conversion of thymic CD4+CD25− T cells into Tregs. Tregs induced by thymic ELPs suppress the proliferation of CD4+CD25− T cells in vitro and in vivo. We further show that neutralization of TGF-β in ELPs partially reverses thymic ELP-mediated induction of CD4+Foxp3+ T cells in the lung and liver. This study demonstrates that thymic ELPs participate in the induction of Foxp3+ Tregs. Also, TGF-β of thymic ELPs might be required for the generation of Tregs in the peripheral tissues.
PMCID: PMC4319673  PMID: 18832678
18.  A Framework for Biobank Sustainability 
Biopreservation and Biobanking  2014;12(1):60-68.
Each year funding agencies and academic institutions spend millions of dollars and euros on biobanking. All funding providers assume that after initial investments biobanks should be able to operate sustainably. However the topic of sustainability is challenging for the discipline of biobanking for several major reasons: the diversity in the biobanking landscape, the different purposes of biobanks, the fact that biobanks are dissimilar to other research infrastructures and the absence of universally understood or applicable value metrics for funders and other stakeholders. In this article our aim is to delineate a framework to allow more effective discussion and action around approaches for improving biobank sustainability. The term sustainability is often used to mean fiscally self-sustaining, but this restricted definition is not sufficient for biobanking. Instead we propose that biobank sustainability should be considered within a framework of three dimensions – financial, operational, and social. In each dimension, areas of focus or elements are identified that may allow different types of biobanks to distinguish and evaluate the relevance, likelihood, and impact of each element, as well as the risks to the biobank of failure to address them. Examples of practical solutions, tools and strategies to address biobank sustainability are also discussed.
PMCID: PMC4150367  PMID: 24620771
19.  IL-23 Promotes TCR-mediated Negative Selection of Thymocytes through the Upregulation of IL-23 Receptor and RORγt 
Nature communications  2014;5:4259.
Transient thymic involution is frequently found during inflammation, yet the mode of action of inflammatory cytokines is not well defined. Here we report that interleukin-23 (IL-23) production by the thymic dendritic cells (DCs) promotes apoptosis of the CD4hiCD8hi double positive (DP) thymocytes. A deficiency in IL-23 signaling interferes with negative selection in the male Db/H-Y T-cell receptor (TCR) transgenic mice. IL-23 plus TCR signaling results in significant up-regulation of IL-23 receptor (IL-23R) expressed predominantly on CD4hiCD8hiCD3+αβTCR+ DP thymocytes, and leads to RORγt dependent apoptosis. These results extend the action of IL-23 beyond its peripheral effects to a unique role in TCR mediated negative selection including elimination of natural T regulatory cells in the thymus.
PMCID: PMC4136447  PMID: 25001511
20.  Loss of N-Myc interactor promotes epithelial-mesenchymal-transition by activation of TGF-β/SMAD signaling 
Oncogene  2013;33(20):2620-2628.
Epithelial-Mesenchymal-Transition (EMT) is one of the critical cellular programs that facilitate the progression of breast cancer to an invasive disease. We have observed that the expression of N-myc interactor (NMI) decreases significantly during progression of breast cancer, specifically in invasive and metastatic stages. Recapitulation of this loss in breast cell lines with epithelial morphology [MCF10A (non-tumorigenic) and T47D (tumorigenic)] by silencing NMI expression causes mesenchymal-like morphological changes in 3-D growth, accompanied by up-regulation of SLUG and ZEB2 and increased invasive properties. Conversely, we found that restoring NMI expression attenuated mesenchymal attributes of metastatic breast cancer cells accompanied by distinctly circumscribed 3-D growth with basement membrane deposition and decreased invasion. Further investigations into the downstream signaling modulated by NMI revealed that NMI expression negatively regulates SMAD signaling, which is a key regulator of cellular plasticity. We demonstrate that NMI blocks TGF-β/SMAD signaling via up-regulation of SMAD7, a negative feedback regulator of the pathway. We also provide evidence that NMI activates STAT signaling which negatively modulates TGF-β/SMAD signaling. Taken together, our findings suggest that loss of NMI during breast cancer progression could be one of the driving factors that enhance invasive ability of breast cancer by aberrant activation of TGF-β/SMAD signaling.
PMCID: PMC4267223  PMID: 23770854
N-Myc interactor; EMT; SMAD; Breast cancer
21.  A histological evaluation and in vivo assessment of intratumoral near infrared photothermal nanotherapy-induced tumor regression 
Nanoparticle (NP)-enabled near infrared (NIR) photothermal therapy has realized limited success in in vivo studies as a potential localized cancer therapy. This is primarily due to a lack of successful methods that can prevent NP uptake by the reticuloendothelial system, especially the liver and kidney, and deliver sufficient quantities of intravenously injected NPs to the tumor site. Histological evaluation of photothermal therapy-induced tumor regression is also neglected in the current literature. This report demonstrates and histologically evaluates the in vivo potential of NIR photothermal therapy by circumventing the challenges of intravenous NP delivery and tumor targeting found in other photothermal therapy studies.
Subcutaneous Cal 27 squamous cell carcinoma xenografts received photothermal nanotherapy treatments, radial injections of polyethylene glycol (PEG)-ylated gold nanorods and one NIR 785 nm laser irradiation for 10 minutes at 9.5 W/cm2. Tumor response was measured for 10–15 days, gross changes in tumor size were evaluated, and the remaining tumors or scar tissues were excised and histologically analyzed.
The single treatment of intratumoral nanorod injections followed by a 10 minute NIR laser treatment also known as photothermal nanotherapy, resulted in ~100% tumor regression in ~90% of treated tumors, which was statistically significant in a comparison to the average of all three control groups over time (P<0.01).
Photothermal nanotherapy, or intratumoral nanorod injections followed by NIR laser irradiation of tumors and tumor margins, demonstrate the potential of NIR photothermal therapy as a viable localized treatment approach for primary and early stage tumors, and prevents NP uptake by the reticuloendothelial system.
PMCID: PMC4227627  PMID: 25395847
photothermal cancer therapy; malignancy; cancer treatment; intratumoral; gold nanorods; nanoparticles; PEGylation; laser therapy
24.  Suppression by L-Methionine of Cell Cycle Progression in LNCaP and MCF-7 Cells but not Benign Cells 
Anticancer research  2010;30(6):1881-1885.
Methionine inhibits proliferation of breast and prostate cancer cells. This study aimed to determine cell cycle effects of methionine and selectivity for cancer cells.
Materials and Methods
MCF-7 (breast), LNCaP (prostate), and LS-174 (colon) cancer cells (wild-type p53), DU-145 (prostate) and SW480 (colon) cancer cells (mutated p53), and immortalized, non-tumorigenic MCF-10A (breast), BPH-1 (prostate), and NCM-460 (colon) epithelial cells were used. Cell cycle effects were assessed by flow cytometry and cell cycle-related gene expression by microarray analysis and QRT-PCR.
L-Methionine at 5 mg/ml for 72 hours (non-apoptotic) arrested cell cycle in LNCaP, DU145, and MCF-7 cells, but not in untransformed cells, nor in LS-174 cells. LNCaP and MCF-7 cells were arrested at G1, but DU-145 at S. Methionine up-regulated CDKIs and down-regulated CDKs.
L-Methionine selectively inhibits proliferation of breast and prostate cancer cells, but not non-tumorigenic cells, and may thus have therapeutic benefits. p53 status appeared to determine the cell cycle stage at which methionine acts.
PMCID: PMC4166481  PMID: 20651330
Methionine; prostate; breast; colon; p53
25.  Translational pathology of neoplasia 
With the increasing use of individualized medical care (personalized medicine) in treating and managing patients with cancer, the utilization of biomarkers in selecting and tailoring such medical approaches also is increasing and becoming more important. Specifically, many therapies are effective against only a subgroup of a specific type of tumors and exposing patients with different non-responsive subgroups of the same tumor to ineffective therapies, not only exposes these patients needlessly to acute and chronic side effects of the therapy, but also adds to the costs of medical care. For example, the Oncotype Dx test for estrogen receptor positive tumors that are node negative has been used to identify low risk tumors for which surgery alone is an adequate therapy. Biomarkers may be used to aid in multiple aspects of medical care related to cancer, including early detection, diagnosis, risk assessment, as well as in predicting the aggressiveness of cancers (i.e., prognosis) and predicting the therapeutic efficacy of treatments (i.e., prediction). Biomarkers may be also used as surrogate endpoints to aid in evaluating therapies and preventive approaches. Types of biomarkers vary greatly and include histopathologic appearance, stage of the lesion, quantitative morphologic features, size of the lesion, metastatic pattern and extent of metastasis, as well as imaging and molecular features. The types of measurements of biomarkers also vary; for example, molecular features can be measured at the DNA, mRNA or protein levels as well as at regulatory levels (e.g., microRNA). The usefulness of each biomarker is limited by its sensitivity and specificity in fulfilling its role (e.g., in early detection) and the requirements of sensitivity and specificity to accomplish specific tasks are affected by multiple variables. For example, both very high specificity and sensitivity of a test are required to screen a population with a low prevalence of a specific tumor. The goal of this manuscript is to introduce the reader to how biomarkers may be used and the limitations on the uses of biomarkers in translational research.
PMCID: PMC3445029  PMID: 22112467
Sensitivity; specificity; early detection; prognosis; risk assessment; surrogate endpoints; diagnosis; receiver operating characteristic; prediction; biomarkers; prevalence; medical costs; side effects; histopathology; molecular features; imaging; prevention; treatment; personalized medicine; individualized medical care

Results 1-25 (124)