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1.  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
2.  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
3.  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
4.  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
5.  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
6.  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
7.  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
8.  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
9.  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
10.  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
11.  Use of human specimens in research: the evolving United States regulatory, policy, and scientific landscape 
The use of human specimens in research has contributed to significant scientific and medical advancements. However, the development of sophisticated whole genome and informatics technologies and the increase in specimen and data sharing have raised new questions about the identifiability of specimens and the protection of participants in human specimen research.
In the US, new regulations and policies are being considered to address these changes. This review discusses the current and proposed regulations as they apply to specimen research, as well as relevant policy discussions. It summarizes the ways that researchers and other stakeholders can provide their input to these discussions and policy development efforts. Input from all the stakeholders in specimen research will be essential for the development of policies that facilitate such research while at the same time protecting the rights and welfare of research participants.
PMCID: PMC3954467  PMID: 24639889
biorepositories; ethical issues; human specimen research; human subjects protection regulations; personalized medicine; research policy
12.  Sulindac selectively inhibits colon tumor cell growth by activating the cGMP/PKG pathway to suppress Wnt/β-catenin signaling 
Molecular cancer therapeutics  2013;12(9):1848-1859.
NSAIDs display promising antineoplastic activity for colorectal and other cancers, but toxicity from cyclooxygenase (COX) inhibition limits their long-term use for chemoprevention. Previous studies have concluded that the basis for their tumor cell growth inhibitory activity does not required COX inhibition, although the underlying mechanism is poorly understood. Here we report that the NSAID, sulindac sulfide (SS) inhibits cyclic guanosine monophosphate phosphodiesterase (cGMP PDE) activity to increase intracellular cGMP levels and activate cGMP dependent protein kinase (PKG) at concentrations that inhibit proliferation and induce apoptosis of colon tumor cells. SS did not activate the cGMP/PKG pathway, nor affect proliferation or apoptosis in normal colonocytes. Knockdown of the cGMP-specific PDE5 isozyme by siRNA and PDE5-specific inhibitors, tadalafil and sildenafil, also selectively inhibited the growth of colon tumor cells that expressed high levels of PDE5 compared with colonocytes. The mechanism by which SS and the cGMP/PKG pathway inhibits colon tumor cell growth appears to involve the transcriptional suppression of β-catenin to inhibit Wnt/β-catenin TCF transcriptional activity, leading to down-regulation of cyclin D1 and survivin. These observations suggest that safer and more efficacious sulindac derivatives can be developed for colorectal cancer chemoprevention by targeting PDE5 and possibly other cGMP degrading isozymes.
PMCID: PMC3800150  PMID: 23804703
colorectal cancer; chemoprevention; sulindac; phosphodiesterase; β-catenin
13.  DCE-MRI Detects Early Vascular Response in Breast Tumor Xenografts Following Anti-DR5 Therapy 
Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) measured the early vascular changes after administration of TRA-8, bevacizumab, or TRA-8 combined with bevacizumab in breast tumor xenografts.
Groups 1–4 of nude mice bearing human breast carcinoma were injected with phosphate-buffered saline, TRA-8, bevacizumab, and TRA-8 + bevacizumab on day0, respectively. DCE-MRI was performed on days0, 1, 2, and 3, and thereafter tumors were collected for terminal deoxynucleotidyl transferase-mediated dUT nick end labeling and CD31 staining.
DCE-MRI measured a significant Ktrans change within 3 days after TRA-8 therapy that correlated with tumor growth arrest, whichwas not shown with statistical significance by histopathology at these early time points posttreatment. The Ktrans changes followed quadratic polynomial curves.
DCE-MRI detected significantly lower Ktrans levels in breast tumor xenografts following TRA-8 monotherapy or combined therapy with bevacizumab.
PMCID: PMC4138021  PMID: 20383593
DCE-MRI; Reference region model; DR5; TRAIL; TRA-8; Bevacizumab; Breast cancer; Novel biomarker
14.  The Prognostic Value of microRNAs Varies with Patient Race/Ethnicity and Stage of Colorectal Cancer 
MicroRNAs (miRNAs) have potential prognostic value for colorectal cancers (CRCs); however, their value based on patient race/ethnicity and pathologic stage has not been determined. The goal was to ascertain the prognostic value of 5 miRNAs with increased expression in CRCs of African American (Black) and non-Hispanic Caucasian (White) patients.
Experimental Design
TaqMan® qRT-PCR was used to quantify expression of miR-20a, miR-21, miR-106a, miR-181b, and miR-203 in paired normal and tumor CRC archival tissues collected from 106 Black and 239 White patients. The results were correlated with overall survival based on patient race/ethnicity and pathologic stage. Since decisions regarding adjuvant therapy are important for Stage III CRCs, and since miR-181b appeared to have prognostic value only for Stage III Black patients, we assessed its prognostic value in a separate cohort of Stage III CRCs of Blacks.
All 5 miRNAs had higher expression in CRCs (>1.0-fold) than in corresponding normal tissues. High expression of miR-203 was associated with poor survival of Whites with Stage IV CRCs (HR=3.00, 95% CI=1.29–7.53), but in Blacks it was an indicator of poor survival of patients with Stage I and II CRCs (HR=5.63, 95% CI=1.03–30.64). Increased miR-21 expression correlated with poor prognosis for White Stage IV patients (HR=2.50, 95% CI=1.07–5.83). In both test and validation cohorts, high miR-181b expression correlated with poor survival of only Black patients with Stage III CRCs (HR=1.94, 95% CI=1.03–3.67).
These preliminary findings suggest that the prognostic value of miRNAs in CRCs varies with patient race/ethnicity and stage of disease.
PMCID: PMC3746330  PMID: 23719259
Race; miRNAs; prognosis; stage; colorectal cancer
15.  Recurrent read-through fusion transcripts in breast cancer 
Read-through fusion transcripts that result from the splicing of two adjacent genes in the same coding orientation are a recently discovered type of chimeric RNA. We sought to determine if read-through fusion transcripts exist in breast cancer. We performed paired-end RNA-seq of 168 breast samples, including 28 breast cancer cell lines, 42 triple negative breast cancer primary tumors, 42 estrogen receptor positive (ER+) breast cancer primary tumors, and 56 non-malignant breast tissue samples. We analyzed the sequencing data to identify breast cancer associated read-through fusion transcripts. We discovered two recurrent read-through fusion transcripts that were identified in breast cancer cell lines, confirmed across breast cancer primary tumors, and were not detected in normal tissues (SCNN1A-TNFRSF1A and CTSD-IFITM10). Both fusion transcripts use canonical splice sites to join the last splice donor of the 5′ gene to the first splice acceptor of the 3′ gene, creating an in-frame fusion transcript. Western blots indicated that the fusion transcripts are translated into fusion proteins in breast cancer cells. Custom small interfering RNAs targeting the CTSD-IFITM10 fusion junction reduced expression of the fusion transcript and reduced breast cancer cell proliferation. Read-through fusion transcripts between adjacent genes with different biochemical functions represent a new type of recurrent molecular defect in breast cancer that warrant further investigation as potential biomarkers and therapeutic targets. Both breast cancer associated fusion transcripts identified in this study involve membrane proteins (SCNN1A-TNFRSF1A and CTSD-IFITM10), which raises the possibility that they could be breast cancer-specific cell surface markers.
Electronic supplementary material
The online version of this article (doi:10.1007/s10549-014-3019-2) contains supplementary material, which is available to authorized users.
PMCID: PMC4085473  PMID: 24929677
16.  Erythropoietin upregulation in pulmonary arterial hypertension 
Pulmonary Circulation  2014;4(2):269-279.
The pathophysiologic alterations of patients with pulmonary arterial hypertension (PAH) are diverse. We aimed to determine novel pathogenic pathways from circulating proteins in patients with PAH. Multianalyte profiling (MAP) was used to measure 90 specifically selected antigens in the plasma of 113 PAH patients and 51 control patients. Erythropoietin (EPO) functional activity was assessed via in vitro pulmonary artery endothelial cell networking and smooth muscle cell proliferation assays. Fifty-eight patients had idiopathic PAH, whereas 55 had other forms of PAH; 5 had heritable PAH, 18 had connective tissue disease (15 with scleroderma and 3 with lupus erythematosis), 13 had portopulmonary hypertension, 6 had PAH associated with drugs or toxins, and 5 had congenital heart disease. The plasma-antigen profile of PAH revealed increased levels of several novel biomarkers, including EPO. Immune quantitative and histochemical studies revealed that EPO not only was significantly elevated in the plasma of PAH patients but also promoted pulmonary artery endothelial cell network formation and smooth muscle cell proliferation. MAP is a hypothesis-generating approach to identifying novel pathophysiologic pathways in PAH. EPO is upregulated in the circulation and lungs of patients with PAH and may affect endothelial and smooth muscle cell proliferation.
PMCID: PMC4070770  PMID: 25006446
pulmonary arterial hypertension; plasma proteomics; multianalyte profiling; erythropoietin
17.  A novel sulindac derivative inhibits lung adenocarcinoma cell growth through suppression of Akt/mTOR signaling and induction of autophagy 
Molecular cancer therapeutics  2013;12(5):663-674.
Nonsteroidal anti-inflammatory drugs (NSAIDs) such as sulindac sulfide (SS) have shown promising antineoplastic activity in multiple tumor types, but toxicities resulting from cyclooxygenase (COX) inhibition limit their use in cancer therapy. We recently described a N, N-dimethylethyl amine derivative of SS, sulindac sulfide amide (SSA), that does not inhibit COX-1 or -2, yet displays potent tumor cell growth inhibitory activity. Here, we studied the basis for the growth inhibitory effects of SSA on human lung adenocarcinoma cell lines. SSA potently inhibited the growth of lung tumor cells with IC50 values of 2–5 μM compared with 44–52 μM for SS. SSA also suppressed DNA synthesis and caused a G0/G1 cell cycle arrest. SSA-induced cell death was associated with characteristics of autophagy, but significant caspase activation or PARP cleavage were not observed after treatment at its IC50 value. siRNA knockdown of Atg7 attenuated SSA-induced autophagy and cell death, while pan-caspase inhibitor ZVAD was not able to rescue viability. SSA treatment also inhibited Akt/mTOR signaling and the expression of downstream proteins that are regulated by this pathway. Overexpression of a constitutively active form of Akt was able to reduce autophagy markers and confer resistance to SSA-induced cell death. Our findings provide evidence that SSA inhibits lung tumor cell growth by a mechanism involving autophagy induction through the suppression of Akt/mTOR signaling. This unique mechanism of action along with its increased potency and lack of cyclooxygenase inhibition support the development of SSA or related analogs for the prevention and/or treatment of lung cancer.
PMCID: PMC3651802  PMID: 23443799
autophagy; chemoprevention; lung cancer; NSAIDs; sulindac
18.  Prediagnostic Serum Biomarkers as Early Detection Tools for Pancreatic Cancer in a Large Prospective Cohort Study 
PLoS ONE  2014;9(4):e94928.
The clinical management of pancreatic cancer is severely hampered by the absence of effective screening tools.
Sixty-seven biomarkers were evaluated in prediagnostic sera obtained from cases of pancreatic cancer enrolled in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO).
The panel of CA 19-9, OPN, and OPG, identified in a prior retrospective study, was not effective. CA 19-9, CEA, NSE, bHCG, CEACAM1 and PRL were significantly altered in sera obtained from cases greater than 1 year prior to diagnosis. Levels of CA 19-9, CA 125, CEA, PRL, and IL-8 were negatively associated with time to diagnosis. A training/validation study using alternate halves of the PLCO set failed to identify a biomarker panel with significantly improved performance over CA 19-9 alone. When the entire PLCO set was used for training at a specificity (SP) of 95%, a panel of CA 19-9, CEA, and Cyfra 21-1 provided significantly elevated sensitivity (SN) levels of 32.4% and 29.7% in samples collected <1 and >1 year prior to diagnosis, respectively, compared to SN levels of 25.7% and 17.2% for CA 19-9 alone.
Most biomarkers identified in previously conducted case/control studies are ineffective in prediagnostic samples, however several biomarkers were identified as significantly altered up to 35 months prior to diagnosis. Two newly derived biomarker combinations offered advantage over CA 19-9 alone in terms of SN, particularly in samples collected >1 year prior to diagnosis. However, the efficacy of biomarker-based tools remains limited at present. Several biomarkers demonstrated significant velocity related to time to diagnosis, an observation which may offer considerable potential for enhancements in early detection.
PMCID: PMC3991628  PMID: 24747429
19.  Early Therapy Evaluation of Combined Cetuximab and Irinotecan in Orthotopic Pancreatic Tumor Xenografts by Dynamic Contrast-Enhanced Magnetic Resonance Imaging 
Molecular imaging  2011;10(3):153-167.
Early pancreatic cancer response following cetuximab and/or irinotecan therapies was measured by serial dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) before and during therapy. Groups 1 to 4 (n = 6/group) of SCID mice bearing orthotopic pancreatic adenocarcinoma xenografts expressing luciferase were treated with phosphate-buffered saline, cetuximab, irinotecan, or cetuximab combined with irinotecan, respectively, twice weekly for 3 weeks. DCE-MRI was performed on days 0, 1, 2, and 3 after therapy initiation, whereas anatomic magnetic resonance imaging was performed on days 0, 1, 2, 3, 6, and 13. Bioluminescence imaging was performed on days 0 and 21. At day 21, all tumors were collected for further histologic analyses (Ki-67 and CD31 staining), whereas tumor dimensions were measured by calipers. The Ktrans values in the 0.5 mm–thick peripheral tumor region were calculated, and the changes in Ktrans during the 3 days posttherapy were compared to tumor volume changes, bioluminescent signal changes, and histologic findings. The Ktrans changes in the peripheral tumor region after 3 days of therapy were linearly correlated with 21-day decreases in tumor volume (p < .001), bioluminescent signal (p = .050), microvessel densities (p = .002), and proliferating cell densities (p = .001). This study supports the clinical use of DCE-MRI for pancreatic cancer patients for early assessment of an anti–epidermal growth factor receptor therapy combined with chemotherapy.
PMCID: PMC3957340  PMID: 21496446
20.  Alcohol and Tobacco Lower the Age of Presentation in Sporadic Pancreatic Cancer in a Dose-Dependent Manner: A Multicenter Study 
The objective of this study was to examine the association between tobacco and alcohol dose and type and the age of onset of pancreatic adenocarcinoma (PancCa).
Prospective data from the Pancreatic Cancer Collaborative Registry were used to examine the association between age of onset and variables of interest including: gender, race, birth country, educational status, family history of PancCa, diabetes status, and tobacco and alcohol use. Statistical analysis included logistic and linear regression, Cox proportional hazard regression, and time-to-event analysis.
The median age to diagnosis for PancCa was 66.3 years (95% confidence intervals (CIs), 64.5–68.0). Males were more likely than females to be smokers (77% vs. 69%, P = 0.0002) and heavy alcohol and beer consumers (19% vs. 6%, 34% vs. 19%, P < 0.0001). In univariate analysis for effects on PancCa presentation age, the following were significant: gender, alcohol and tobacco use (amount, status and type), family history of PancCa, and body mass index. Both alcohol and tobacco had dose-dependent effects. In multivariate analysis, alcohol status and dose were independently associated with increased risk for earlier PancCa onset with greatest risk occurring in heavy drinkers (HR 1.62, 95% CI 1.04–2.54). Smoking status had the highest risk for earlier onset pancreatic cancer with a HR of 2.69 (95% CI, 1.97–3.68) for active smokers and independent effects for dose (P = 0.019). The deleterious effects for alcohol and tobacco appear to resolve after 10 years of abstinence.
Alcohol and tobacco use are associated with a dose-related increased risk for earlier age of onset of PancCa. Although beer drinkers develop pancreatic cancer at an earlier age than nondrinkers, alcohol type did not have a significant effect after controlling for alcohol dose.
PMCID: PMC3923585  PMID: 22929760
21.  New NSAID Targets and Derivatives for Colorectal Cancer Chemoprevention 
Clinical and preclinical studies provide strong evidence that nonsteroidal anti-inflammatory drugs (NSAIDs) can prevent numerous types of cancers, especially colorectal cancer. Unfortunately, the depletion of physiologically important prostaglandins due to cyclooxygenase (COX) inhibition results in potentially fatal toxicities that preclude the long-term use of NSAIDs for cancer chemoprevention. While studies have shown an involvement of COX-2 in colorectal tumorigenesis, other studies suggest that a COX-independent target may be at least partially responsible for the antineoplastic activity of NSAIDs. For example, certain NSAID derivatives have been identified that do not inhibit COX-2 but have demonstrated efficacy to suppress carcinogenesis with potential for reduced toxicity. A number of alternative targets have also been reported to account for the tumor cell growth inhibitory activity of NSAIDs, including the inhibition of cyclic guanosine monophosphate phosphodiesterases (cGMP PDEs), generation of reactive oxygen species (ROS), the suppression of the apoptosis inhibitor protein, survivin, and others. Here, we review several promising mechanisms that are being targeted to develop safer and more efficacious NSAID derivatives for colon cancer chemoprevention.
PMCID: PMC3703626  PMID: 22893202
22.  The Effect of Antigen Retrieval on Cells Fixed in 10% Neutral Buffered Formalin Followed by Transfer to 70% Ethanol 
PLoS ONE  2013;8(12):e82405.
Fixation in 10% neutral buffered formalin prior to transfer to 70% ethanol for one week has been shown to adequately preserve immunorecognition of PCNA, cytokeratins AE1/AE3 and EGFr. This study investigated whether 12 hrs fixation in 10% NBF plus transfer to 70% ethanol for 4 weeks would similarly preserve immunorecognition to an extent where antigen retrieval (AR) used to reverse the masking effects of fixation on some antigens would not be necessary. Two cell lines, DU145 and SKOV3 were grown on coverslips and fixed either for 684 hrs in 10% NBF or for 12 hrs in 10% NBF which was then replaced with 70% ethanol for 672 hrs. The second experiment had the same design except an additional set of cells were subjected to heat-induced AR concomitantly. PCNA, cytokeratins AE1/AE3, and EGFr (membrane and cytoplasmic) were used to evaluate the effects of immunorecognition. Fixation in 10% NBF for 12 hrs plus transfer to 70% ethanol for 672 hrs did not preserve immunorecognition of PCNA adequately in either cell lines. Cytokeratins immunoreactivity was preserved by transfer to 70% ethanol. Cytoplasmic EGFr antigens were not adversely affected by 10% NBF fixation in either cell line and transfer to 70% ethanol had limited effects. With AR, there was little recovery of PCNA immunorecognition on cells fixed in only 10% NBF, but almost complete recovery for cells transferred to 70% ethanol. For cytokeratins there was complete recovery of immunorecognition either with only 10% NBF or 12 hrs plus transfer to 70% ethanol. For EGFr, AR resulted in complete loss of immunorecognition following either treatment. This study indicated that 12 hrs of fixation in 10% NBF plus transfer to 70% ethanol for 4 weeks with AR resulted in recovery of immunorecognition for PCNA and cytokeratins, but standard methods of AR caused loss of immunorecognition of EGFr.
PMCID: PMC3866107  PMID: 24358179
25.  Validation of a robust proteomic analysis carried out on formalin-fixed paraffin-embedded tissues of the pancreas obtained from mouse and human 
Proteomics  2012;12(22):3393-3402.
A number of reports have recently emerged with focus on extraction of proteins from formalin-fixed paraffin-embedded (FFPE) tissues for MS analysis; however, reproducibility and robustness as compared to flash frozen controls is generally overlooked. The goal of this study was to identify and validate a practical and highly robust approach for the proteomics analysis of FFPE tissues. FFPE and matched frozen pancreatic tissues obtained from mice (n = 8) were analyzed using 1D-nanoLC-MS(MS)2 following work up with commercially available kits. The chosen approach for FFPE tissues was found to be highly comparable to that of frozen. In addition, the total number of unique peptides identified between the two groups was highly similar, with 958 identified for FFPE and 1070 identified for frozen, with protein identifications that corresponded by approximately 80%. This approach was then applied to archived human FFPE pancreatic cancer specimens (n = 11) as compared to uninvolved tissues (n = 8), where 47 potential pancreatic ductal adenocarcinoma markers were identified as significantly increased, of which 28 were previously reported. Further, these proteins share strongly overlapping pathway associations to pancreatic cancer that include estrogen receptor α. Together, these data support the validation of an approach for the proteomic analysis of FFPE tissues that is straightforward and highly robust, which can also be effectively applied toward translational studies of disease.
PMCID: PMC3656494  PMID: 22997103
Animal proteomics; FPE; LC-MS; Nontagged proteomics; Pancreatic cancer; Systems biology

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