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1.  A Comprehensive Gene Expression Analysis of Resistance Formation upon Metronomic Cyclophosphamide Therapy12 
Translational Oncology  2013;6(1):1-9.
Resistance formation is one of the major hurdles in cancer therapy. Metronomic anti-angiogenic treatment of xenografted prostate cancer tumors in severe combined-immunodeficiency (SCID) mice with cyclophosphamide (CPA) results in the appearance of resistant tumors. To investigate the complex molecular changes occurring during resistance formation, we performed a comprehensive gene expression analysis of the resistant tumors in vivo. We observed a multitude of differentially expressed genes, e.g., PAS domain containing protein 1, annexin A3 (ANXA3), neurotensin, or plasminogen activator tissue (PLAT), when comparing resistant to in vivo passaged tumor samples. Furthermore, tumor cells from in vivo and in vitro conditions showed a significant difference in target gene expression. We assigned the differentially expressed genes to functional pathways like axon guidance, steroid biosynthesis, and complement and coagulation cascades. Most of these genes were involved in anti-coagulation. Up-regulation of anticoagulatory ANXA3 and PLAT and down-regulation of PLAT inhibitor serpin peptidase inhibitor clade A were validated by quantitative real-time polymerase chain reaction. In contrast, coagulation factor F3 was upregulated, accompanied by the expression of an altered gene product. These findings give insights into the resistance mechanisms of metronomic CPA treatment, suggesting an important role of anti-coagulation in resistance formation.
PMCID: PMC3573648  PMID: 23418611
2.  The Reliability of Endoscopic Biopsies in Assessing HER2 Status in Gastric and Gastroesophageal Junction Cancer: A Study Comparing Biopsies with Surgical Samples 
Translational Oncology  2013;6(1):10-16.
AIM: The aim of this study is to validate the accuracy of HER2 assessment on biopsies by comparing matched biopsy/surgical material from the same patients. METHODS: HER2 status was evaluated by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) in 103 cases of gastric and gastroesophageal junction cancers in coupled biopsy and surgical material. RESULT: Complete concordance between IHC and FISH results on biopsy versus surgical samples was noted in 80% and 95% of cases, respectively. At comprehensive comparison, including IHC and FISH data on biopsy and surgical samples, 89% of biopsies were predictive of HER2 status in surgical samples, whereas 11% showed variable inconsistencies. The majority of these (10 of 12 cases) showed IHC score 0/1+ on biopsy but were all IHC positive and amplified at surgery; in particular, three (3 of 35; 8.5%) IHC score 0 and four (4 of 16; 25%) IHC score 1+ cases were FISH amplified on biopsy material also, whereas the remaining three cases were FISH non-amplified on biopsy. The percentage of cases, which were FISH amplified with IHC score 1+ or 2+ on biopsies, were similar (25% and 33%, respectively) and they also shared a similar grade of amplification. These data suggest that both IHC score 1+ and 2+ on biopsy material represent “equivocal cases” that may merit further investigation. CONCLUSIONS: The predictive value of HER2 IHC in biopsies is high. FISH analysis should be considered for IHC score 2+ and 1+ biopsy cases. Approximately 8% of cases will not be accurately predicted by biopsy evaluation.
PMCID: PMC3573649  PMID: 23418612
3.  Evaluation of Neoadjuvant Chemotherapy Response in Women with Locally Advanced Breast Cancer Using Ultrasound Elastography1 
Translational Oncology  2013;6(1):17-24.
PURPOSE: Ultrasound elastography is a new imaging technique that can be used to assess tissue stiffness. The aim of this study was to investigate the potential of ultrasound elastography for monitoring treatment response of locally advanced breast cancer patients undergoing neoadjuvant therapy. METHODS: Fifteen women receiving neoadjuvant chemotherapy had the affected breast scanned before, 1, 4, and 8 weeks following therapy initiation, and then before surgery. Changes in elastographic parameters related to tissue biomechanical properties were then determined and compared to clinical and pathologic tumor response after mastectomy. RESULTS: Patients who responded to therapy demonstrated a significant decrease (P < .05) in strain ratios and strain differences 4 weeks after treatment initiation compared to non-responding patients. Mean strain ratio and mean strain difference for responders was 81 ± 3% and 1 ± 17% for static regions of interest (ROIs) and 81 ± 3% and 6 ± 18% for dynamic ROIs, respectively. In contrast, these parameters were 102±2%, 110±17%, 101±4%, and 109±30% for non-responding patients, respectively. Strain ratio using static ROIs was found to be the best predictor of treatment response, with 100% sensitivity and 100% specificity obtained 4 weeks after starting treatment. CONCLUSIONS: These results suggest that ultrasound elastography can be potentially used as an early predictor of tumor therapy response in breast cancer patients.
PMCID: PMC3573650  PMID: 23418613
4.  Cytotoxicity of Anthrax Lethal Toxin to Human Acute Myeloid Leukemia Cells Is Nonapoptotic and Dependent on Extracellular Signal-Regulated Kinase 1/2 Activity1 
Translational Oncology  2013;6(1):25-32.
In this study, we attempt to target the mitogen-activated protein kinase (MAPK) pathway in acute myeloid leukemia (AML) cells using a recombinant anthrax lethal toxin (LeTx). LeTx consists of protective antigen (PrAg) and lethal factor (LF). PrAg binds cells, is cleaved by furin, oligomerizes, binds three to four molecules of LF, and undergoes endocytosis, releasing LF into the cytosol. LF cleaves MAPK kinases, inhibiting the MAPK pathway. We tested potency of LeTx on a panel of 11 human AML cell lines. Seven cell lines showed cytotoxic responses to LeTx. Cytotoxicity of LeTx was mimicked by the specific mitogen-activated protein/extracellular signal-regulated kinase kinase 1/2 (MEK1/2) inhibitor U0126, indicating that LeTx-induced cell death is mediated through the MEK1/2-extracellular signal-regulated kinase (ERK1/2) branch of the MAPK pathway. The four LeTx-resistant cell lines were sensitive to the phosphatidylinositol 3-kinase inhibitor LY294002. Co-treatment of AML cells with both LeTx and LY294002 did not lead to increased sensitivity, showing a lack of additive/synergistic effects when both pathways are inhibited. Flow cytometry analysis of MAPK pathway activation revealed the presence of phospho-ERK1/2 only in LeTx-sensitive cells. Staining for Annexin V/propidium iodide and active caspases showed an increase in double-positive cells and the absence of caspase activation following treatment, indicating that LeTx-induced cell death is caspase-independent and nonapoptotic. We have shown that a majority of AML cell lines are sensitive to the LF-mediated inhibition of the MAPK pathway. Furthermore, we have demonstrated that LeTx-induced cytotoxicity in AML cells is nonapoptotic and dependent on phospho-ERK1/2 levels.
PMCID: PMC3573651  PMID: 23418614
5.  High-Resolution Optical Molecular Imaging of Changes in Choline Metabolism in Oral Neoplasia1 
Translational Oncology  2013;6(1):33-41.
This study was aimed at developing an optical molecular imaging approach to measure differences in uptake and intracellular retention of choline in clinically isolated tissue biopsies from head and neck cancer patients. An optically detectable analogue of choline (propargyl choline) was synthesized and evaluated in 2D and 3D models and clinically isolated paired biopsies (n = 22 biopsies). Fluorescence contrast between clinically abnormal and normal tissues based on uptake and intracellular retention of propargyl choline was measured and correlated with pathologic diagnosis. Results in 2D and 3D models demonstrated a rapid uptake of propargyl choline in cancer cells, uniform permeation in tissue models, and specific detection of intracellular entrapped propargyl choline using the click chemistry reaction with an azide-modified Alexa 488 dye. Fluorescence imaging measurements following topical delivery of propargyl choline in clinically isolated biopsies showed that the mean fluorescence intensity (MFI) of neoplastic tissues was four-fold to five-fold higher than the MFI of clinically and pathologically normal samples. This difference in fluorescence contrast was measured on the basis of comparison of paired biopsy sets isolated from individual patients as well as comparison of clinically abnormal and normal biopsies independent of anatomic locations in the head and neck cavity and across diverse patients. In conclusion, a novel imaging approach based on monoalkyne-modified choline was developed and validated using cell and tissue models. Results in clinically isolated tissue biopsies demonstrate a significant fluorescent contrast between neoplastic and normal tissues and illustrate high specificity of the optical imaging approach.
PMCID: PMC3573652  PMID: 23418615
6.  Diverse Responses to Vascular Disrupting Agent Combretastatin A4 Phosphate: A Comparative Study in Rats with Hepatic and Subcutaneous Tumor Allografts Using MRI Biomarkers, Microangiography, and Histopathology1 
Translational Oncology  2013;6(1):42-50.
OBJECTIVE: Differently located tumors of the same origin may exhibit diverse responses to the same therapeutics. To test this hypothesis, we compared the responses of rodent hepatic and subcutaneous engrafts of rhabdomyosarcoma-1 (R1) to a vascular disrupting agent Combretastatin A4 phosphate (CA4P). METHODS: Twelve WAG/Rij rats, each bearing three R1 implanted in the right and left hepatic lobes and subcutaneously in the thoracic region, received CA4P intravenously at 5 mg/kg (n = 6) or solvent (n = 6). Therapeutic responses were compared interindividually and intraindividually among tumors of different sites till 48 hours after injection using in vivo MRI, postmortem digital microangiography, and histopathology. RESULTS: MRI revealed that the subcutaneous tumors (STs) significantly increased in volume than hepatic tumors (HTs) 48 hours after CA4P (P < .05). Relative to vehicle controls and treated group at baseline, necrosis ratio, apparent diffusion coefficient, and enhancement ratio changed slightly with the STs but significantly with HTs (P < .05) after CA4P treatment. Vessel density derived from microangiography was significantly lower in STs compared to HTs without CA4P treatment. CA4P treatment resulted in decreased vessel density in HTs, while it did not affect vessel density in STs. MRI and microangiography outcomes were supported by histopathologic findings. CONCLUSIONS: MRI and microangiography allowed quantitative comparison of therapeutic responses to CA4P in rats with multifocal tumors. The discovered diverse effects of the same drug on tumors of the same origin but different locations emphasize the presence of cancer heterogeneity and the importance of individualization of drug delivery.
PMCID: PMC3573653  PMID: 23418616
7.  Three-Dimensional Telomeric Analysis of Isolated Circulating Tumor Cells (CTCs) Defines CTC Subpopulations12 
Translational Oncology  2013;6(1):51-65.
Circulating tumor cells (CTCs) have been identified with the potential to serve as suitable biomarkers for tumor stage and progression, but the availability of effective isolation technique(s) coupled with detailed molecular characterization have been the challenges encountered in making CTCs clinically relevant. For the first time, we combined isolation of CTCs using the ScreenCell filtration technique with quantitative analysis of CTC telomeres by TeloView. This resulted in the identification and molecular characterization of different subpopulations of CTCs in the same patient. Three-dimensional (3D) telomeric analysis was carried out on isolated CTCs of 19 patients that consisted of four different tumor types, namely, prostate, colon, breast, melanoma, and one lung cancer cell line. With telomeric analysis of the filter-isolated CTCs, the level of chromosomal instability (CIN) of the CTCs can be determined. Our study shows that subpopulations of CTCs can be identified on the basis of their 3D telomeric properties.
PMCID: PMC3573654  PMID: 23418617
8.  Changes in the Secretory Profile of NSCLC-Associated Fibroblasts after Ablative Radiotherapy: Potential Impact on Angiogenesis and Tumor Growth1 
Translational Oncology  2013;6(1):66-74.
In the context of radiotherapy, collateral effects of ablative doses of ionizing radiation (AIR) on stromal components of tumors remains understudied. In this work, cancer-associated fibroblasts (CAFs) isolated from freshly resected human lung tumors were exposed to AIR (1x 18 Gy) and analyzed for their release of paracrine factors. Inflammatory mediators and regulators of angiogenesis and tumor growth were analyzed by multiplex protein assays in conditioned medium (CM) from irradiated and non-irradiated CAFs. Additionally, the profile of secreted proteins was examined by proteomics. In functional assays, effects of CAF-CM on proliferative and migratory capacity of lung tumor cells (H-520/H-522) and human umbilical vein endothelial cells (HUVECs) and their tube-forming capacity were assessed. Our data show that exposure of CAFs to AIR results in 1) downregulated release of angiogenic molecules such as stromal cell-derived factor-1, angiopoietin, and thrombospondin-2 (TSP-2); 2) upregulated release of basic fibroblast growth factor from most donors; and 3) unaffected expression levels of hepatocyte growth factor, interleukin-6 (IL-6), IL-8, IL-1β, and tumor necrosis factor-α. CM from irradiated and control CAFs did not affect differently the proliferative or migratory capacity of tumor cells (H-520/H-522), whereas migratory capacity of HUVECs was partially reduced in the presence of irradiated CAF-CM. Overall, we conclude that AIR mediates a transformation on the secretory profile of CAFs that could influence the behavior of other cells in the tumor tissue and hence guide therapeutic outcomes. Downstream consequences of the changes observed in this study merits further investigations.
PMCID: PMC3573655  PMID: 23418618
9.  GL3, a Novel 4β-Anilino-4′-O-Demethyl-4-Desoxypodophyllotoxin Analog, Traps Topoisomerase II Cleavage Complexes and Exerts Anticancer Activities1 
Translational Oncology  2013;6(1):75-82.
A novel VP-16 derivative, 4β-[N -(4‴-acetyloxyl-phenyl-1‴-carbonyl)-4″-aminoanilino]-4′-O-demethyl-4-desoxypodophyllotoxin (GL3), displayed a wide range of cytotoxicity in a panel of human tumor cell lines, with half-maximal inhibitory concentration (IC50) values ranging from 0.82 to 4.88 µM, much less than that of VP-16 (4.18–39.43 µM). Importantly, GL3 induces more significant apoptosis and cell cycle arrest than VP-16. The molecular and cellular machinery studies showed that GL3 functions as a topoisomerase II (Top 2) poison through direct binding to the enzyme, and the advanced cell-killing activities of GL3 were ascribed to its potent effects on trapping Top 2-DNA cleavage complex, Moreover, GL3-triggered DNA double-strand breaks and apoptotic cell death were in a Top 2-dependent manner, because the catalytic inhibitor aclarubicin attenuated these biologic consequences caused by Top 2 poisoning in GL3-treated cells. Taken together, among a series of 4β-anilino-4′-O-demethyl-4-desoxypodophyllotoxin analog, GL3 stood out by its improved anticancer activity and well-defined Top 2 poisoning mechanisms, which merited the potential value of GL3 as an anticancer lead compound/drug candidate deserving further development.
PMCID: PMC3573656  PMID: 23418619
10.  Arsenic Trioxide as a Vascular Disrupting Agent: Synergistic Effect with Irinotecan on Tumor Growth Delay in a CT26 Allograft Model1 
Translational Oncology  2013;6(1):83-91.
The mechanism of action of arsenic trioxide (ATO) has been shown to be complex, influencing numerous signal transduction pathways and resulting in a vast range of cellular effects. Among these mechanisms of action, ATO has been shown to cause acute vascular shutdown and massive tumor necrosis in a murine solid tumor model like vascular disrupting agent (VDA). However, relatively little is understood about this VDA-like property and its potential utility in developing clinical regimens. We focused on this VDA-like action of ATO. On the basis of the endothelial cell cytotoxicity assay and tubulin polymerization assay, we observed that higher concentrations and longer treatment with ATO reduced the level of α- and β-tubulin and inhibited the polymerization of tubulin. The antitumor action and quantitative tumor perfusion studies were carried out with locally advanced murine CT26 colon carcinoma grown in female BALB/c mice. A single injection of ATO intraperitoneally displayed central necrosis of the tumor tissue by 24 hours. T1-weighted dynamic contrast-enhanced magnetic resonance image revealed a significant decrease in tumor enhancement in the ATO-treated group. Similar to other VDAs, ATO treatment alone did not delay the progression of tumor growth; however, ATO treatment after injection of other cytotoxic agent (irinotecan) showed significant additive antitumor effect compared to control and irinotecan alone therapy. In summary, our data demonstrated that ATO acts as a VDA by means of microtubule depolymerization. It exhibits significant vascular shutdown activity in CT26 allograft model and enhances antitumor activity when used in combination with another cytotoxic chemotherapeutic agent.
PMCID: PMC3573657  PMID: 23418620
11.  Erratum 
Translational Oncology  2013;6(1):erratum.
PMCID: PMC3573658  PMID: 23418621
12.  Gene Signatures in Breast Cancer: Current and Future Uses 
Translational Oncology  2012;5(6):398-403.
Gene signatures have been developed for estrogen receptor-positive breast cancer to complement pathological factors in providing prognostic information. The 70-gene and the 21-gene signatures identify patients who may not require adjuvant chemotherapy. Gene signatures in triple-negative disease and HER2-positive disease have not been fully developed yet, although studies demonstrate heterogeneity within these subgroups. Further research is needed before genotyping will help in making clinical decisions in triple-negative and HER2-positive disease. Molecular subtyping of breast cancer led to define luminal, basal, and HER2-enriched subtypes, which have specific clinical behavior. This approach may lead to identify new subgroups requiring specific therapies. Standardization of techniques will be required to translate investigations to the clinic.
PMCID: PMC3542834  PMID: 23323153
13.  A Systemic Complete Response of Metastatic Melanoma to Local Radiation and Immunotherapy 
Translational Oncology  2012;5(6):404-407.
BACKGROUND: Melanoma is a relatively immunogenic tumor, in which infiltration of melanoma cells by T lymphocytes is associated with a better clinical prognosis. We hypothesized that radiation-induced cell death may provide additional stimulation of an anti-tumor immune response in the setting of anti-CTLA-4 treatment. METHODS: In a pilot melanoma patient, we prospectively tested this hypothesis. We treated the patient with two cycles of ipilimumab, followed by stereotactic ablative radiotherapy to two of seven hepatic metastases, and two additional cycles of ipilimumab. RESULTS: Subsequent positron emission tomography-computed tomography scan indicated that all metastases, including unirradiated liver lesions and an unirradiated axillary lesion, had completely resolved, consistent with a complete response by RECIST. CONCLUSION: The use of radiotherapy in combination with targeted immunotherapy as a noninvasive in vivo tumor vaccine strategy appears to be a promising method of enhancing the induction of systemic immune responses and anti-tumor effect.
PMCID: PMC3542835  PMID: 23323154
14.  Microscopic Delineation of Medulloblastoma Margins in a Transgenic Mouse Model Using a Topically Applied VEGFR-1 Probe1 
Translational Oncology  2012;5(6):408-414.
The unambiguous demarcation of tumor margins is critical at the final stages in the surgical treatment of brain tumors because patient outcomes have been shown to correlate with the extent of resection. Real-time high-resolution imaging with the aid of a tumor-targeting fluorescent contrast agent has the potential to enable intraoperative differentiation of tumor versus normal tissues with accuracy approaching the current gold standard of histopathology. In this study, a monoclonal antibody targeting the vascular endothelial growth factor receptor 1 (VEGFR-1) was conjugated to fluorophores and evaluated as a tumor contrast agent in a transgenic mouse model of medulloblastoma. The probe was administered topically, and its efficacy as an imaging agent was evaluated in vitro using flow cytometry, as well as ex vivo on fixed and fresh tissues through immunohistochemistry and dual-axis confocal microscopy, respectively. Results show a preferential binding to tumor versus normal tissue, suggesting that a topically applied VEGFR-1 probe can potentially be used with real-time intraoperative optical sectioning microscopy to guide brain tumor resections.
PMCID: PMC3542836  PMID: 23323155
15.  Multimodality Imaging of Tumor and Bone Response in a Mouse Model of Bony Metastasis1 
Translational Oncology  2012;5(6):415-421.
Cancer drug development generally performs in vivo evaluation of treatment effects that have traditionally relied on detection of morphologic changes. The emergence of new targeted therapies, which may not result in gross morphologic changes, has spurred investigation into more specific imaging methods to quantify response, such as targeted fluorescent probes and bioluminescent cells. The present study investigated tissue response to docetaxel or zoledronic acid (ZA) in a mouse model of bony metastasis. Intratibial implantations of breast cancer cells (MDA-MB-231) were monitored throughout this study using several modalities: molecular resonance imaging (MRI) tumor volume and apparent diffusion coefficient (ADC), micro-computed tomography (µCT) bone volume, bioluminescence imaging (BLI) reporting cancer cell apoptosis, and fluorescence using Osteosense 800 and CatK 680-FAST. Docetaxel treatment resulted in tumor cell kill reflected by ADC and BLI increases and tumor volume reduction, with delayed bone recovery seen in µCT prefaced by increased osteoblastic activity (Osteosense 800). In contrast, the ZA treatment group produced similar values in MRI, BLI, and Osteosense 800 fluorescence imaging readouts when compared to controls. However, µCT bone volume increased significantly by the first week post-treatment and the CatK 680-FAST signal was slightly diminished by 4 weeks following ZA treatment. Multimodality imaging provides a more comprehensive tool for new drug evaluation and efficacy screening through identification of morphology as well as function and apoptotic signaling.
PMCID: PMC3542837  PMID: 23323156
16.  Evidence of mTOR Activation by an AKT-Independent Mechanism Provides Support for the Combined Treatment of PTEN-Deficient Prostate Tumors with mTOR and AKT Inhibitors1 
Translational Oncology  2012;5(6):422-429.
Activation of the phosphoinositide 3-kinase pathway is commonly observed in human prostate cancer. Loss of function of phosphatase and tensin homolog (PTEN) is associated with the activation of AKT and mammalian target of rapamycin (mTOR) in many cancer cell lines as well as in other model systems. However, activation of mTOR is also dependent of kinases other than AKT. Here, we show that activation of mTOR is not dependent on AKT in a prostate-specific PTEN-deficient mouse model of prostate cancer. Pathway bifurcation of AKT and mTOR was noted in both mouse and human prostate tumors. We demonstrated for the first time that cotargeting mTOR and AKT with ridaforolimus/MK-8669 and M1K-2206, respectively, delivers additive antitumor effects in vivo when compared to single agents. Our preclinical data suggest that the combination of AKT and mTOR inhibitors might be more effective in treating prostate cancer patients than current treatment regimens or either treatment alone.
PMCID: PMC3542838  PMID: 23323157
17.  Analysis of the BRAFV600E Mutation in Central Nervous System Tumors1 
Translational Oncology  2012;5(6):430-436.
BRAFV600E mutations are involved in the development of melanoma, colon cancer, and papillary thyroid carcinoma. These mutations are also found in primary brain tumors at low to moderate frequencies. In this study, we investigated a series of brain tumors to determine the prevalence and associated clinicopathologic features of BRAFV600E mutations. By direct sequencing, we analyzed 223 brain tumors, including 51 gangliogliomas (GGs), 45 pilocytic astrocytomas (PAs), 12 pleomorphic xanthoastrocytomas (PXAs), 35 glioblastomas (GBs), 28 anaplastic astrocytomas (AAs), 44 oligodendroglial tumors (ODGs), 3 anaplastic oligoastrocytomas, and 5 diffuse astrocytomas. Thirty-six cases (16.1%) exhibited the BRAFV600E mutation, including 66.7% of PXAs, 23.5% of GGs, 15.6% of PAs, and 9.7% of the malignant gliomas; the latter included 14.3% of AAs, 8.6% of GBs, and 4.5% of ODGs. Copy number aberration at the 7q34 (BRAF) locus was found in 73.1% of PAs and 50% of PXAs. 9p Homozygous deletion was found in 66.7% of PXAs, but it was not correlated with the BRAFV600E mutation. Patients' age, sex, histologic grade, and progression-free survival were also not correlated with the BRAFV600E mutation. The BRAFV600E mutation in brain tumors did not have prognostic value but is certainly a diagnostic marker and therapeutic target, not only for pediatric low-grade gliomas but also for malignant gliomas, even though the rate of mutation was not high. These results should be verified in a larger study with more cases and a longer follow-up period to overcome the limitation of small sample size.
PMCID: PMC3542839  PMID: 23323158
18.  Heterogeneity of ERα and ErbB2 Status in Cell Lines and Circulating Tumor Cells of Metastatic Breast Cancer Patients12 
Translational Oncology  2012;5(6):475-485.
Hormone therapy and anti-ErbB2 therapies are prescribed according to the hormone receptor [estrogen receptor α (ERα)/progesterone receptor] and ErbB2 status of the initial tumor, but it appears that circulating tumor cells (CTCs) and, consequently, the metastatic cells may have a different receptor status. As an attempt to meet the crucial need for identification of the subpopulation of patients that will benefit from more individualized therapies, rapidly evolving therapies should allow a profiling of the tumors and/or of the CTCs. We established a triple fluorescence staining using eight cell lines to visualize the CTCs (cytokeratin detection) and then to define their individual ERα and ErbB2 status. Afterward, we used this method for blood samples from 26 metastatic breast cancer patients. We identified major differences of ERα levels between the cell lines and even within one cell line. For the metastatic patients, we detected and characterized CTCs in 38.5% of the patients with a total of 92 CTCs. We could demonstrate that at least 69.6% of the CTCs exhibit an ERα and/or ErbB2 status different from the status of the primary tumor and that the CTCs from only 30% of the patients had no change of receptor status. Strikingly, heterogeneities of the status, aggregation, and size clearly appear within the CTCs. The data we generated outline the importance of a profiling not only of tumors but also of CTCs to establish individualized treatments. CTCs may then appear as new prognosis and treatment marker for both metastatic and adjuvant breast cancers.
PMCID: PMC3542840  PMID: 23323159
19.  Interpretation of Changes in Circulating Tumor Cell Counts12 
Translational Oncology  2012;5(6):486-491.
The presence of circulating tumor cells (CTCs) in the blood of cancer patients may guide the use of therapy. We investigated how to evaluate a reduction in the number of CTCs after administration of therapy. CTCs were enumerated with the CellSearch system in 111 metastatic breast and 185 metastatic prostate cancer patients before start of a new line of chemotherapy and after initiation of therapy. Different means to express changes in CTC counts were evaluated with respect to overall survival (OS). A static CTC cutoff is the best method to determine whether a therapy is effective. This is exemplified by the highest Cox hazard ratio of 2.1 for OS; three methods to express relative differences performed worse. A lookup table is provided from which the significance of a change in CTCs can be derived. The aim of therapy should be the elimination of all CTCs. A period of 10 to 12 weeks of therapy is needed to reach the treatment effect on CTCs.
PMCID: PMC3542841  PMID: 23323160
20.  Superior Therapeutic Index of Calmangafodipir in Comparison to Mangafodipir as a Chemotherapy Adjunct1 
Translational Oncology  2012;5(6):492-502.
Mangafodipir is a magnetic resonance imaging contrast agent with manganese superoxide dismutase (MnSOD) mimetic activity. The MnSOD mimetic activity protects healthy cells against oxidative stress-induced detrimental effects, e.g., myelosuppressive effects of chemotherapy drugs. The contrast property depends on in vivo dissociation of Mn2+ from mangafodipir—about 80% dissociates after injection. The SOD mimetic activity, however, depends on the intact Mn complex. Complexed Mn2+ is readily excreted in the urine, whereas dissociated Mn2+ is excreted slowly via the biliary route. Mn is an essential but also a potentially neurotoxic metal. For more frequent therapeutic use, neurotoxicity due to Mn accumulation in the brain may represent a serious problem. Replacement of 4/5 of Mn2+ in mangafodipir with Ca2+ (resulting in calmangafodipir) stabilizes it from releasing Mn2+ after administration, which roughly doubles renal excretion of Mn. A considerable part of Mn2+ release from mangafodipir is governed by the presence of a limited amount of plasma zinc (Zn2+). Zn2+ has roughly 103 and 109 times higher affinity than Mn2+ and Ca2+, respectively, for fodipir. Replacement of 80% of Mn2+ with Ca2+ is enough for binding a considerable amount of the readily available plasma Zn2+, resulting in considerably less Mn2+ release and retention in the brain and other organs. At equivalent Mn2+ doses, calmangafodipir was significantly more efficacious than mangafodipir to protect BALB/c mice against myelosuppressive effects of the chemotherapy drug oxaliplatin. Calmangafodipir did not interfere negatively with the antitumor activity of oxaliplatin in CT26 tumor-bearing syngenic BALB/c mice, contrary calmangafodipir increased the antitumor activity.
PMCID: PMC3542842  PMID: 23323161
21.  Mapping Tumor Hypoxia In Vivo Using Pattern Recognition of Dynamic Contrast-enhanced MRI Data12 
Translational Oncology  2012;5(6):437-447.
In solid tumors, hypoxia contributes significantly to radiation and chemotherapy resistance and to poor outcomes. The “gold standard” pO2 electrode measurements of hypoxia in vivo are unsatisfactory because they are invasive and have limited spatial coverage. Here, we present an approach to identify areas of tumor hypoxia using the signal versus time curves of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) data as a surrogate marker of hypoxia. We apply an unsupervised pattern recognition (PR) technique to determine the differential signal versus time curves associated with different tumor microenvironmental characteristics in DCE-MRI data of a preclinical cancer model. Well-perfused tumor areas are identified by rapid contrast uptake followed by rapid washout; hypoxic areas, which are regions of reduced vascularization, are identified by delayed contrast signal buildup and washout; and necrotic areas exhibit slow or no contrast uptake and no discernible washout over the experimental observation. The strength of the PR concept is that it captures the pixel-enhancing behavior in its entirety—during both contrast agent uptake and washout—and thus, subtleties in the temporal behavior of contrast enhancement related to features of the tumor microenvironment (driven by vascular changes) may be detected. The assignment of the tumor compartments/microenvironment to well vascularized, hypoxic, and necrotic is validated by comparison to data previously obtained using complementary imaging modalities. The proposed novel analysis approach has the advantage that it can be readily translated to the clinic, as DCE-MRI is used routinely for the identification of tumors in patients, is widely available, and easily implemented on any clinical magnet.
PMCID: PMC3546126  PMID: 23326621
22.  Histologic Parameters Predictive of Disease Outcome in Women with Advanced Stage Ovarian Carcinoma Treated with Neoadjuvant Chemotherapy1 
Translational Oncology  2012;5(6):469-474.
The use of neoadjuvant chemotherapy followed by tumor reduction surgery, also called interval debulking surgery (IDS), is considered an alternative therapeutic regimen for selected patients with advanced stage epithelial ovarian cancer (EOC). Although minimal residual disease has been proven to be a prognostic factor in traditional cytoreduction for advanced stage EOC, predictive factors after IDS still remain unexplored. The aim of this study was to determine the prognostic value of post-neoadjuvant histologic changes with clinical outcome. Three pathologists evaluated 67 cases for the following parameters: fibrosis, necrosis, residual tumor, and inflammation. The Cohen's kappa statistic was used to measure agreement among pathologists. Univariate and multivariate Cox proportional hazards models were used to determine the association between histologic parameters and recurrence-free survival (RFS) and overall survival (OS). There was substantial to almost perfect agreement among the three pathologists in all four histologic parameters (k ranged from 0.65 to 0.97). Fibrosis was associated with longer RFS (P = 0.0257) with a median of 20 months for tumors with fibrosis (3+) versus 12 months for tumors with fibrosis (1+, 2+) and longer OS (P = 0.0249) with a median of 51 months for tumors with fibrosis (3+) versus 32 months for tumors with fibrosis (1+, 2+). Our results revealed that patients with tumors exhibiting fibrosis (1+, 2+), as well as necrosis (0, 1+), had significant shorter RFS and OS (P = 0.059 and P = 0.0234, respectively). We suggest that the assessment of fibrosis and necrosis should be implemented in pathologic evaluation and prospectively validated in future studies.
PMCID: PMC3567723  PMID: 23397476
23.  Polymorphisms of CHRNA5-CHRNA3-CHRNB4 Gene Cluster and NSCLC Risk in Chinese Population1 
Translational Oncology  2012;5(6):448-452.
AIM: To explore the potential association between single-nucleotide polymorphisms (SNPs) and haplotypes of the CHRNA5-CHRNA3-CHRNB4 gene cluster and the non-small cell lung cancer (NSCLC) susceptibility in never-smoking Chinese. METHODS: A case-control study was conducted with 200 NSCLC patients and 200 healthy controls, matched on age and sex. Five SNPs distributed in CHRNA5-CHRNA3-CHRNB4 gene cluster were selected for genotyping. The association between genotype and lung cancer risk was evaluated by computing the odds ratio (OR) and 95% confidence interval (CI) from multivariate unconditional logistic regression analyses with adjustment for gender and age. RESULTS: For CHRNA3 rs578776 status, data were available in 199 NSCLC patients and 199 controls. The G/G homozygote in CHRNB4 rs7178270 had a reduced risk of developing NSCLC (OR = 0.553; 95% CI = 0.309–0.989; P = .0437), especially squamous cell carcinoma (SQC) (OR = 0.344; 95% CI = 0.161–0.732; P = .0043), compared with those who carry at least one C allele (C/C and C/G). The polymorphisms of rs578776, rs938682, rs17486278, and rs11637635 were not significantly different between controls and cases or between controls and histologic subgroups, adenocarcinoma and SQC, respectively. CONCLUSIONS: In our study, we found that the SNP of CHRNB4 rs7178270 is significantly associated with reduced risk of NSCLC, especially with reduced risk of SQC in never-smoking Chinese population.
PMCID: PMC3567724  PMID: 23397474
24.  Specific Biomarkers Are Associated with Docetaxeland Gemcitabine-Resistant NSCLC Cell Lines1 
Translational Oncology  2012;5(6):461-468.
Five-year survival rate for lung cancer is limited to 10% to 15%. Therefore, the identification of novel therapeutic prognostic factors is an urgent requirement. The aim of this study is thus to highlight specific biomarkers in chemoresistant non-small cell lung cancer cell lines. Therefore, we checked—in the control condition as well as after short-term pharmacological treatment with either docetaxel or gemcitabine—the expression of genes such as tumor suppressor genes (CDKN2A, DAPK, FHIT, GSTP1, MGMT, RARβ2, RASSF1A, and TIMP3), genes associated with drug resistance (BRCA1, COX2, ERCC1, IGFBP3, RRM1, and TUBB3), and stemness-related genes (CD133, OCT4, and SLUG) in two cellular models of squamous carcinoma (CAEP) and adenocarcinoma (RAL) of the lung originally established. Their promoter methylation profile was also evaluated. Drug-related genes were upregulated. Cisplatin resistance matched with high levels of BRCA1 and ERCC1 in both cell lines; docetaxel sensitivity of CAEP cells was associated to levels of TUBB3 lower than RAL cells. Although CAEP cells were more sensitive to gemcitabine, both cell lines showed high levels of RRM1. Stemness-related genes were downregulated in the control condition but became upregulated in docetaxel-resistant cells, indicating the selection of a population with stemness features. We did not find an unequivocal correspondence between gene expression and respective DNA promoter methylation status, suggesting the involvement of additional mechanisms of gene expression regulation. These results highlight specific biomarkers consistent with the different responses of the two cell lines to standard pharmacological treatments and indicate specific molecular traits for their chemoresistance.
PMCID: PMC3567725  PMID: 23397475
25.  The 16p13.3 (PDPK1) Genomic Gain in Prostate Cancer: A Potential Role in Disease Progression1 
Translational Oncology  2012;5(6):453-460.
BACKGROUND: Prostate cancer (PCa) is a leading cause of cancer death, and distinguishing aggressive from indolent tumors is a major challenge. Identification and characterization of genomic alterations associated with advanced disease can provide new markers of progression and better therapeutic approaches. METHODS: We performed fluorescence in situ hybridization to detect the copy number gain of chromosome 16p13.3 in 75 PCa samples including 10 lymph node (LN) metastases and their matched primary tumors, 9 samples of castration-resistant prostate cancer (CRPC), and 46 additional primary PCa specimens with clinicopathologic parameters. RESULTS: We detected the gain in 5 of 10 LN metastases and 3 of 5 matched primary tumors, 3 of 9 CRPC samples, and 9 of 46 (20%) primary tumors where the 16p13.3 alteration was associated with high Gleason score and elevated preoperative prostate-specific antigen levels. The level of 16p13.3 gain was higher in LN metastasis and CRPC specimens compared to primary PCa. Chromosome mapping revealed the gain spans PDPK1 encoding the 3-phosphoinositide-dependent protein kinase-1 (PDK1). Knockdown of PDK1 in three PCa cell lines reduced migration without affecting growth and re-expressing PDK1 rescued motility. CONCLUSION: Our findings support a prognostic value of the 16p13.3 gain and a role of PDK1 in PCa progression through migration.
PMCID: PMC3568696  PMID: 23401739

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