bluuebunny/crossref_metadata_2025 huggingface dataset:
Validation of Biomarker-Based Risk Prediction Models
Authors: Taylor Jeremy M.G. , Ankerst Donna P. , Andridge Rebecca R.
Published: October 2008

The increasing availability and use of predictive models to facilitate informed decision making highlights the need for careful assessment of the validity of these models. In particular, models involving biomarkers require careful validation for two reasons: issues with overfitting when complex models involve a large number of biomarkers, and interlaboratory variation in assays used to measure biomarkers. In this article, we distinguish between internal and external statistical validation. Internal validation, involving training-testing splits of the available data or cross-validation, is a necessary component of the model building process and can provide valid assessments of model performance. External validation consists of assessing model performance on one or more data sets collected by different investigators from different institutions. External validation is a more rigorous procedure necessary for evaluating whether the predictive model will generalize to populations other than the one on which it was developed. We stress the need for an external data set to be truly external, that is, to play no role in model development and ideally be completely unavailable to the researchers building the model. In addition to reviewing different types of validation, we describe different types and features of predictive models and strategies for model building, as well as measures appropriate for assessing their performance in the context of validation. No single measure can characterize the different components of the prediction, and the use of multiple summary measures is recommended.
Statistical Issues in Translational Cancer Research
Authors: George Stephen L.
Published: October 2008

The explosion of knowledge about the basic biological processes and the genetics of cancer has led to increasing optimism that this knowledge can be put to practical clinical use in the near future. Indeed, important examples of translational approaches can already be found in the areas of drug discovery and development, disease diagnosis and classification, selection of therapeutic regimens for individual patients, and designing clinical trials. These are important developments but, as with any new approach, there is a danger of unwarranted enthusiasm and premature clinical application of laboratory results based on insufficient evidence. To carry out the translation of knowledge into practice with maximal efficiency and effectiveness, it is essential to conduct studies with appropriate designs and analyses based on sound statistical principles. This article provides an overview of some of these principles applied to assay development, validation of predictive models, and the design of clinical trials for targeted therapies.
An Immunotolerant HER-2/neuTransgenic Mouse Model of Metastatic Breast Cancer
Authors: Song Hong , Shahverdi Karineh , Huso David L. , Wang Yuchuan , Fox James J. , Hobbs Robert F. , Gimi Barjor , Gabrielson Kathleen L. , Pomper Martin G. , Tsui Benjamin M. , Bhujwalla Zaver , Reilly R. Todd , Sgouros George
Published: October 2008

Purpose: Animal models of breast cancer metastases that recapitulate the pattern of metastatic progression seen in patients are lacking; metastatic breast cancer models do not currently exist for evaluation of immune-mediated therapies. We have developed and characterized a preclinical model for the evaluation of immune-mediated metastatic breast cancer therapies.

Experimental Design: The NT2.5 mammary tumor cell line was injected into the left cardiac ventricle of immunotolerant transgenic neu-N mice and athymic nu/nu mice. Metastatic progression was monitored by bioluminescent, small-animal magnetic resonance imaging, positron emission tomography, single-photon emission computed tomography/computed tomography imaging, and also by histopathology. Antigen expression in normal organs and tumor metastases was evaluated by Western blot analysis and flow cytometry.

Results: Left cardiac ventricle injection of NT2.5 cells yielded widespread metastases in bones, liver, and spleen. Three to four weeks after injection, mice exhibited hind limb paralysis and occasional abdominal enlargement. Bioluminescence imaging of metastatic progression was successful in nude mice but the bioluminescent cells were rejected in immunocompetent mice. Other imaging modalities allowed successful imaging of nonbioluminescent cells. Small-animal positron emission tomography imaging allowed visualization of disease, in vivo, in the bones and liver. Magnetic resonance imaging revealed initial dissemination of the tumor cells to the bone marrow. Small-animal single-photon emission computed tomography/computed tomography imaging identified metastatic bone lesions targeted by a radiolabeled antibody.

Conclusion: The model closely recapitulates the pattern of metastatic spread in breast cancer. This immunotolerant metastatic model is a novel addition to existing breast cancer models and coupling the model with in vivo imaging greatly facilitates the evaluation of targeted immunotherapies of metastasis.
IFN-Induced Transmembrane Protein 1 Promotes Invasion at Early Stage of Head and Neck Cancer Progression
Authors: Hatano Hiroko , Kudo Yasusei , Ogawa Ikuko , Tsunematsu Takaaki , Kikuchi Akira , Abiko Yoshimitsu , Takata Takashi
Published: October 2008

Purpose: Head and neck squamous cell carcinoma (HNSCC) shows persistent invasion that frequently leads to local recurrence and distant lymphatic metastasis. However, molecular mechanisms associated with invasion of HNSCC remain poorly understood. We identified IFN-induced transmembrane protein 1 (IFITM1) as a candidate gene for promoting the invasion of HNSCC by comparing the gene expression profiles between parent and a highly invasive clone. Therefore, we examined the role of IFITM1 in the invasion of HNSCC.

Experimental Design: IFITM1 expression was examined in HNSCC cell lines and cases by reverse transcription–PCR and immunohistochemistry. IFITM1 overexpressing and knockdown cells were generated, and the invasiveness of these cells was examined by in vitro invasion assay. Gene expression profiling of HNSCC cells overexpressing IFITM1 versus control cells was examined by microarray.

Results: HNSCC cells expressed IFITM1 mRNA at higher levels, whereas normal cells did not. By immunohistochemistry, IFITM1 expression was observed in early invasive HNSCC and invasive HNSCC. Interestingly, IFITM1 was expressed at the invasive front of early invasive HNSCC, and higher expression of IFITM1 was found in invasive HNSCC. In fact, IFITM1 overexpression promoted and IFITM1 knockdown suppressed the invasion of HNSCC cells in vitro. Gene expression profiling of HNSCC cells overexpressing IFITM1 versus control cells revealed that several genes, including matrix metalloproteinase, were up-regulated in IFITM1 overexpressing cells.

Conclusion: Our findings suggest that IFITM1 plays an important role for the invasion at the early stage of HNSCC progression and that IFITM1 can be a therapeutic target for HNSCC.
Constitutively Activated STAT3 Frequently Coexpresses with Epidermal Growth Factor Receptor in High-Grade Gliomas and Targeting STAT3 Sensitizes Them to Iressa and Alkylators
Authors: Lo Hui-Wen , Cao Xinyu , Zhu Hu , Ali-Osman Francis
Published: October 2008

Purpose: The goals of this study are to elucidate the relationship of the oncogenic transcription factor signal transducer and activator of transcription 3 (STAT3) with glioma aggressiveness and to understand the role of high STAT3 activity in the resistance of malignant gliomas and medulloblastomas to chemotherapy.

Experimental Design: Immunohistochemical staining and biochemical methods were used to examine the extent of STAT3 activation and EGFR expression in primary specimens and cell lines, respectively. Cellular response to drug treatments was determined using cell cytotoxicity and clonogenic growth assays.

Results: We found STAT3 to be constitutively activated in 60% of primary high-grade/malignant gliomas and the extent of activation correlated positively with glioma grade. High levels of activated/phosphorylated STAT3 were also present in cultured human malignant glioma and medulloblastoma cells. Three STAT3-activating kinases, Janus-activated kinase 2 (JAK2), EGFR, and EGFRvIII, contributed to STAT3 activation. An inhibitor to JAK2/STAT3, JSI-124, significantly reduced expression of STAT3 target genes, suppressed cancer cell growth, and induced apoptosis. Furthermore, we found that STAT3 constitutive activation coexisted with EGFR expression in 27.2% of primary high-grade/malignant gliomas and such coexpression correlated positively with glioma grade. Combination of an anti-EGFR agent Iressa and a JAK2/STAT3 inhibitor synergistically suppressed STAT3 activation and potently killed glioblastoma cell lines that expressed EGFR or EGFRvIII. JSI-124 also sensitized malignant glioma and medulloblastoma cells to temozolomide, 1,3-bis(2-chloroethyl)-1-nitrosourea, and cisplatin in which a synergism existed between JSI-124 and cisplatin.

Conclusion: STAT3 constitutive activation, alone and in concurrence with EGFR expression, plays an important role in high-grade/malignant gliomas and targeting STAT3/JAK2 sensitizes these tumors to anti-EGFR and alkylating agents.
Shedding of Distinct Cryptic Collagen Epitope (HU177) in Sera of Melanoma Patients
Authors: Ng Bruce , Zakrzewski Jan , Warycha Melanie , Christos Paul J. , Bajorin Dean F. , Shapiro Richard L. , Berman Russell S. , Pavlick Anna C. , Polsky David , Mazumdar Madhu , Montgomery Anthony , Liebes Leonard , Brooks Peter C. , Osman Iman
Published: October 2008

Purpose: Extracellular matrix remodeling during tumor growth plays an important role in angiogenesis. Our preclinical data suggest that a newly identified cryptic epitope (HU177) within collagen type IV regulates endothelial and melanoma cell adhesion in vitro and angiogenesis in vivo. In this study, we investigated the clinical relevance of HUI77 shedding in melanoma patient sera.

Experimental Design: Serum samples from 291 melanoma patients prospectively enrolled at the New York University Medical Center and 106 control subjects were analyzed for HU177 epitope concentration by a newly developed sandwich ELISA assay. HU177 serum levels were then correlated with clinical and pathologic parameters.

Results: Mean HU177 epitope concentration was 5.8 ng/mL (range, 0-139.8 ng/mL). A significant correlation was observed between HU177 concentration and nodular melanoma histologic subtype [nodular, 10.3 ± 1.6 ng/mL (mean ± SE); superficial spreading melanoma, 4.5 ± 1.1 ng/mL; all others, 6.1 ± 2.1 ng/mL; P = 0.01 by ANOVA test]. Increased HU177 shedding also correlated with tumor thickness (≤1.00 mm, 3.8 ± 1.1 ng/mL; 1.01-3.99 mm, 8.7 ± 1.3 ng/mL; ≥4.00 mm, 10.3 ± 2.4 ng/mL; P = 0.003 by ANOVA). After multivariate analysis controlling for thickness, the correlation between higher HU177 concentration and nodular subtype remained significant (P = 0.03). The mean HU177 epitope concentration in control subjects was 2.4 ng/mL.

Conclusions: We report that primary melanoma can induce detectable changes in systemic levels of cryptic epitope shedding. Our data also support that nodular melanoma might be biologically distinct compared with superficial spreading type melanoma. As targeted interventions against cryptic collagen epitopes are currently undergoing phase I clinical trial testing, these findings indicate that patients with nodular melanoma may be more susceptible to such targeted therapies.
Prevention of Anastrozole-Induced Bone Loss with Monthly Oral Ibandronate during Adjuvant Aromatase Inhibitor Therapy for Breast Cancer
Authors: Lester James E. , Dodwell David , Purohit Omprakash P. , Gutcher Sandra A. , Ellis Susan P. , Thorpe Ruth , Horsman Janet M. , Brown Janet E. , Hannon Rosemary A. , Coleman Robert E.
Published: October 2008

Purpose: The aromatase inhibitor anastrozole is a highly effective well-tolerated treatment for postmenopausal endocrine-responsive breast cancer. However, its use is associated with accelerated bone loss and an increase in fracture risk. The ARIBON trial is a double-blind, randomized, placebo-controlled study designed to evaluate the impact of bisphosphonate treatment on bone mineral density (BMD) in women taking anastrozole.

Experimental Design: BMD was assessed in 131 postmenopausal, surgically treated women with early breast cancer at two U.K. centers. Of these, 50 patients had osteopenia (T score −1.0 to −2.5) at either the hip or lumbar spine. All patients were treated with anastrozole 1 mg once a day and calcium and vitamin D supplementation. In addition, osteopenic patients were randomized to receive either treatment with ibandronate 150 mg orally every month or placebo.

Results: After 2 years, osteopenic patients treated with ibandronate gained +2.98% (range −8.9, +19.9) and +0.60% (range −9.0, +6.9) at the lumbar spine and hip, respectively. Patients treated with placebo, however, lost −3.22% (range −16.0, +4.3) at the lumbar spine and −3.90% (range −12.3, +7.2) at the hip. The differences between the two treatment arms were statistically significant at both sites (P < 0.01). At 12 months, urinary n-telopeptide, serum c-telopeptide, and serum bone–specific alkaline phosphatase levels declined in patients receiving ibandronate (30.9%, 26.3%, and 22.8%, respectively) and increased in those taking placebo (40.3%, 34.9%, and 37.0%, respectively).

Conclusions: Monthly oral ibandronate improves bone density and normalizes bone turnover in patients treated with anastrozole.
Phase I Trial of Erlotinib Combined with Cisplatin and Radiotherapy for Patients with Locally Advanced Cervical Squamous Cell Cancer
Authors: Nogueira-Rodrigues Angélica , do Carmo Cláudio C. , Viegas Célia , Erlich Felipe , Camisão Cláudia , Fontão Karina , Lima Roberta , Herchenhorn Daniel , Martins Renato G. , Moralez Giulliana M. , Small Isabele A. , Ferreira Carlos G.
Published: October 2008

Purpose: This phase I trial was aimed to determine the maximum tolerated dose and related toxicity of erlotinib (E) when administered concurrently with standard chemoradiation (CRT) for cervical cancer.

Experimental Design: In a modified Fibonacci design, the study aimed to study three cohorts of at least three patients receiving escalating doses of erlotinib (50/100/150 mg) combined with cisplatin (40 mg/m2, weekly, 5 cycles) and radiotherapy (external beam 4,500 cGy in 25 fractions, followed by 4 fractions/600 cGy/weekly of brachytherapy) in squamous cell cervical carcinoma patients, stage IIB to IIIB.

Results: Fifteen patients were enrolled, 3 at dose level (DL) 50 mg, 4 at DL 100 mg, and 8 at DL 150 mg. Patients presented median age 47 (36-59), stage IIB (46.2%) and IIIB (53.8%). Overall, E+CRT was well-tolerated. Three patients did not complete the planned schedule. One patient at DL 100 mg withdrew informed consent due to grade 2 rash; at DL 150 mg, 1 patient presented Raynaud's Syndrome and had C interrupted, and another patient presented grade 4 hepatotoxicity. The latter was interpreted as dose limiting toxicity and a new cohort of 150 mg was started. No further grade 4 toxicity occurred. Grade 3 toxicity occurred in 6 cases: diarrhea in 3 patients, rash in 2 patients, and leukopenia in 1 patient. E+CRT did not lead to limiting in-field toxicity.

Conclusions: E+CRT is feasible to locally advanced squamous cell cervical cancer and is well tolerated. The maximum tolerated dose has been defined as 150 mg. To the best of our knowledge, this is the first report of a combination of erlotinib, cisplatin, and pelvic radiotherapy.
Letrozole is Superior to Anastrozole in Suppressing Breast Cancer Tissue and Plasma Estrogen Levels
Authors: Geisler Jürgen , Helle Hilgegunn , Ekse Dagfinn , Duong Nhat K. , Evans Dean B. , Nordbø Yngve , Aas Turid , Lønning Per E.
Published: October 2008

Purpose: To evaluate the influence of the third-generation aromatase inhibitor letrozole (Femara) on breast cancer tissue levels of estrone (E1), estradiol (E2), and estrone sulfate (E1S) in postmenopausal women undergoing primary treatment for locally advanced estrogen receptor/progesterone receptor–positive breast cancers.

Experimental Design: Breast cancer tissue samples were collected before and following 4 months of neoadjuvant therapy with letrozole (2.5 mg o.d.), and tissue estrogen levels measured using a highly sensitive RIA after high-pressure liquid chromatography purification.

Results: Letrozole suppressed pretreatment tumor levels of E2, E1, and E1S by 97.6%, 90.7%, and 90.1%, respectively. These data reveal that letrozole suppresses tissue estrogen levels significantly below what has previously been recorded with anastrozole (89.0%, 83.4%, and 72.9% suppression, respectively) using the same methods. To confirm the differential effect of letrozole and anastrozole on each plasma estrogen fraction, we re-analyzed plasma samples obtained from a previous intrapatient cross-over study comparing letrozole and anastrozole using an improved RIA (detection limits of 0.67, 1.14, and 0.55 pmol/L for E2, E1, and E1S, respectively). Letrozole consistently suppressed each plasma estrogen fraction below the levels recorded for anastrozole: E2 (average suppression by 95.2% versus 92.8%; P = 0.018), E1 (98.8% suppression versus 96.3%; P = 0.003), and E1S (98.9% suppression versus 95.3%; P = 0.003).

Conclusion: Our data reveals that letrozole (2.5 mg o.d.) is more effective compared with anastrozole (1.0 mg o.d.) with respect to tissue as well as plasma estrogen suppression in patients with postmenopausal breast cancer.
Multimodality Imaging of IL-18–Binding Protein-Fc Therapy of Experimental Lung Metastasis
Authors: Cao Qizhen , Cai Weibo , Niu Gang , He Lina , Chen Xiaoyuan
Published: October 2008

Purpose: Interleukin (IL)-18 plays important roles in cancer progression and metastasis. The goal of this study is to identify cell lines that are most sensitive to stand alone IL-18–binding protein (IL-18bp)-Fc treatment, to study the pharmacokinetics and tumor targeting efficiency of IL-18bp-Fc, and to evaluate the efficacy of IL-18bp-Fc in treating breast cancer experimental lung metastasis by multimodality imaging.

Experimental Design: Reverse transcription-PCR, ELISA, and other cell-based assays were done on murine 4T1, CT-26, and B16F10 cells. The most IL-18bp-Fc–sensitive 4T1 cells were stably transfected with firefly luciferase (fLuc) and injected i.v. into female BALB/C mice to establish the experimental lung metastasis model. Tumor targeting efficiency and pharmacokinetics of IL-18bp-Fc was assessed by 64Cu-DOTA-IL-18bp-Fc positron emission tomography (PET) and biodistribution studies. Two groups of fLuc-4T1 experimental lung metastasis tumor-bearing mice were each given saline or IL-18bp-Fc (1 mg/kg) daily i.p. Bioluminescence imaging, 18F-FDG PET, and computed tomography scans were done to evaluate the treatment efficacy. Ex vivo experiments were also carried out to validate the imaging results.

Results: IL-18bp-Fc had high and specific accumulation in the fLuc-4T1 lung metastasis tumor as evidenced by both PET and biodistribution studies. Bioluminescence imaging, 18F-FDG PET, and computed tomography scans all revealed that IL-18bp-Fc treatment was effective in inhibiting the lung metastasis tumor progression, validated by ex vivo examination of the lung.

Conclusions: IL-18bp-Fc therapy can inhibit 4T1 breast cancer experimental lung metastasis. Noninvasive multimodality molecular imaging is a powerful tool for evaluating the tumor targeting efficiency/pharmacokinetics of the drug and effective monitoring of the therapeutic response.
Immunohistochemical Expression of Basic Fibroblast Growth Factor and Fibroblast Growth Factor Receptors 1 and 2 in the Pathogenesis of Lung Cancer
Authors: Behrens Carmen , Lin Heather Y. , Lee J. Jack , Raso Maria Gabriela , Hong Waun Ki , Wistuba Ignacio I. , Lotan Reuben
Published: October 2008

Purpose: To identify the patterns of protein expression of basic fibroblast growth factor (bFGF) and FGF receptors 1 and 2 in non-small cell lung carcinoma (NSCLC) and their role in the early pathogenesis of squamous cell carcinoma (SCC) of the lung.

Experimental Design: Archived tissue from NSCLC (adenocarcinoma and SCC; n = 321) and adjacent bronchial epithelial specimens (n = 426) were analyzed for the immunohistochemical expression of bFGF, FGFR1, and FGFR2, and the findings were correlated with clinicopathologic features of the patients.

Results: High expression of bFGF, FGFR1, and FGFR2 was shown in most NSCLC tumors. The pattern of expression for all markers varied according to tumor histologic type and cellular localization. Cytoplasmic expression scores were significantly higher in tumors than in normal epithelia. Nuclear bFGF (P = 0.03) and FGFR1 (P = 0.02) levels were significantly higher in women than in men. Although cytoplasmic FGFR1 expression was significantly higher (P = 0.002) in ever smokers than in never smokers, nuclear FGFR1 (P = 0.0001) and FGFR2 (P = 0.003) expression was significantly higher in never smokers. Different prognostic patterns for the expression of these markers were detected for both NSCLC histologic types. Dysplastic changes showed significantly higher expression of all markers compared with squamous metaplasia.

Conclusions: bFGF, FGFR1, and FGFR2 are frequently overexpressed in SCC and adenocarcinoma of the lung. bFGF signaling pathway activation may be an early phenomenon in the pathogenesis of SCC and thus an attractive novel target for lung cancer chemopreventive and therapeutic strategies.
CpG Island Methylator Phenotype Associates with Low-Degree Chromosomal Abnormalities in Colorectal Cancer
Authors: Cheng Yu-Wei , Pincas Hanna , Bacolod Manny D. , Schemmann Gunter , Giardina Sarah F. , Huang Jianmin , Barral Sandra , Idrees Kamran , Khan Sajid A. , Zeng Zhaoshi , Rosenberg Shoshana , Notterman Daniel A. , Ott Jurg , Paty Philip , Barany Francis
Published: October 2008

Purpose: Aberrant promoter methylation and genomic instability occur frequently during colorectal cancer development. CpG island methylator phenotype (CIMP) has been shown to associate with microsatellite instability, and BRAF mutation and is often found in the right-side colon. Nevertheless, the relative importance of CIMP and chromosomal instability (CIN) for tumorigenesis has yet to be thoroughly investigated in sporadic colorectal cancers.

Experimental Design: We determined CIMP in 161 primary colorectal cancers and 66 matched normal mucosae using a quantitative bisulfite/PCR/ligase detection reaction (LDR)/Universal Array assay. The validity of CIMP was confirmed in a subset of 60 primary tumors using MethyLight assay and five independent markers. In parallel, CIN was analyzed in the same study cohort using Affymetrix 50K Human Mapping arrays.

Results: The identified CIMP-positive cancers correlate with microsatellite instability (P = 0.075) and the BRAF mutation V600E (P = 0.00005). The array-based high-resolution analysis of chromosomal aberrations indicated that the degree of aneuploidy is spread over a wide spectrum among analyzed colorectal cancers. Whether CIN was defined by copy number variations in selected microsatellite loci (criterion 1) or considered as a continuous variable (criterion 2), CIMP-positive samples showed a strong correlation with low-degree chromosomal aberrations (P = 0.075 and P = 0.012, respectively). Similar correlations were observed when CIMP was determined by MethyLight assay (P = 0.001 and P = 0.013, respectively).

Conclusion: CIMP-positive tumors generally possess lower chromosomal aberrations, which may only be revealed using a genome-wide approach. The significant difference in the degree of chromosomal aberrations between CIMP-positive and the remainder of samples suggests that epigenetic (CIMP) and genetic (CIN) abnormalities may arise from independent molecular mechanisms of tumor progression.
Hypoxia-Adenosinergic Immunosuppression: Tumor Protection by T Regulatory Cells and Cancerous Tissue Hypoxia
Authors: Sitkovsky Michail V. , Kjaergaard Jorgen , Lukashev Dmitriy , Ohta Akio
Published: October 2008

Cancerous tissue protection from tumor-recognizing CD8+ and CD4+ T cells (antitumor T cells) limits the therapeutic potential of immunotherapies. We propose that tumor protection is to a large extent due to (a) inhibition of antitumor T cells by hypoxia-driven accumulation of extracellular adenosine in local tumor microenvironment and due to (b) T regulatory cell-produced extracellular adenosine. The adenosine triggers the immunosuppressive signaling via intracellular cyclic AMP–elevating A2A adenosine receptors (A2AR) on antitumor T cells. In addition, the activated antitumor T cells in hypoxic tumor microenvironment could be inhibited by elevated levels of immunosuppressive hypoxia-inducible factor-1α. Complete rejection or tumor growth retardation was observed when A2AR has been genetically eliminated or antagonized with synthetic drug or with natural A2AR antagonist 1,3,7-trimethylxanthine (caffeine). The promising strategy may be in combining the anti-hypoxia-adenosinergic treatment that prevents inhibition of antitumor T cells by tumor-produced and T regulatory cell-produced adenosine with targeting of other negative regulators, such as CTL antigen-4 blockade. Observations of tumor rejection in mice and massive prospective epidemiologic studies support the feasibility of anti-hypoxia-adenosinergic combined immunotherapy.
Immunohistochemical and Biogenetic Features of Diffuse-Type Tenosynovial Giant Cell Tumors: The Potential Roles of Cyclin A, P53, and Deletion of 15q in Sarcomatous Transformation
Authors: Huang Hsuan-Ying , West Robert B. , Tzeng Ching-Cherng , van de Rijn Matt , Wang Jun-Wen , Chou Shih-Cheng , Huang Wen-Wei , Eng Hock-Liew , Lin Ching-Nan , Yu Shih-Chen , Wu Jing-Mei , Lu Chiu-Chin , Li Chien-Feng
Published: October 2008

Purpose: Diffuse-type tenosynovial giant cell tumor (D-TSGCT) is an aggressive proliferation of synovial-like mononuclear cells with inflammatory infiltrates. Despite the COL6A3-CSF1 gene fusion discovered in benign lesions, molecular aberrations of malignant D-TSGCTs remain unidentified.

Experimental Design: We used fluorescent in situ hybridization and in situ hybridization to evaluate CSF1 translocation and mRNA expression in six malignant D-TSGCTs, which were further immunohistochemically compared with 24 benign cases for cell cycle regulators involving G1 phase and G1-S transition. Comparative genomic hybridization, real-time reverse transcription-PCR, and a combination of laser microdissection and sequencing were adopted to assess chromosomal imbalances, cyclin A expression, and TP53 gene, respectively.

Results: Five of six malignant D-TSGCTs displayed CSF1 mRNA expression by in situ hybridization, despite only one having CSF1 translocation. Cyclin A (P = 0.008) and P53 (P < 0.001) could distinguish malignant from benign lesions without overlaps in labeling indices. Cyclin A transcripts were more abundant in malignant D-TSGCTs (P < 0.001). All malignant cases revealed a wild-type TP53 gene, which was validated by an antibody specifically against wild-type P53 protein. Chromosomal imbalances were only detected in malignant D-TSGCTs, with DNA losses predominating over gains. Notably, −15q was recurrently identified in five malignant D-TSGCTs, four of which showed a minimal overlapping deletion at 15q22-24.

Conclusions: Deregulated CFS1 overexpression is frequent in malignant D-TSGCTs. The sarcomatous transformation involves aberrations of cyclin A, P53, and chromosome arm 15q. Cyclin A mRNA is up-regulated in malignant D-TSGCTs. Non–random losses at 15q22-24 suggest candidate tumor suppressor gene(s) in this region. However, P53 overexpression is likely caused by alternative mechanisms rather than mutations in hotspot exons.
Differentiation of Human Embryonic Stem Cells into Immunostimulatory Dendritic Cells under Feeder-Free Culture Conditions
Authors: Su Zhen , Frye Carole , Bae Kyung-Mi , Kelley Vicky , Vieweg Johannes
Published: October 2008

Purpose: The objective of this study was to develop a scalable and broadly applicable active immunotherapy approach against cancer, circumventing the limitations typically encountered with autologous vaccination strategies. We hypothesized that human embryonic stem cells (hESC) can serve as a virtually unlimited source for generating dendritic cells (DC) with potent antigen-presenting function. Here, we investigated the developmental processes and requirements for generating large numbers of mature, antigen-presenting DC from pluripotent hESC.

Experimental Design: A feeder cell-free culture system was developed to differentiate hESC into mature DC sequentially through hematopoietic and myeloid precursor stages.

Results: Using this method, we were able to yield large numbers of mature immunostimulatory DC from hESC to enable clinical investigation. Upon activation, the hESC-derived DC secreted interleukin-12p70, migrated in response to MIP-3β, and exhibited allostimulatory capacity. Most importantly, antigen-loaded, hESC-derived DC were capable of stimulating potent antigen-specific CD8+ T-cell responses in an HLA class I–matched semiallogeneic assay system. Moreover, HLA class II–mismatched hESC-derived DC induced a potent Th1-type cytokine response without expanding FOXP3+ regulatory T cells in vitro.

Conclusions: These data suggest the development of a novel active immunotherapy platform to stimulate potent T-cell immunity in patients with intractable diseases, such as cancer or viral infection.
Epidermal Growth Factor Receptor Mutations in Small Cell Lung Cancer
Authors: Tatematsu Akiko , Shimizu Junichi , Murakami Yoshiko , Horio Yoshitsugu , Nakamura Shigeo , Hida Toyoaki , Mitsudomi Tetsuya , Yatabe Yasushi
Published: October 2008

Purpose: The vast majority of epidermal growth factor receptor (EGFR) mutations occur in lung adenocarcinoma, and even rare cases of other subtypes with this mutation, such as adenosquamous cell carcinoma, are associated with adenocarcinoma histology. According to this adenocarcinoma-specific nature of EGFR mutation, analysis of EGFR mutations with small cell lung cancers (SCLC) may provide a clue to its histogenesis.

Experimental Design: The mutational status of the EGFR gene was accessed in a cohort of 122 patients with SCLC; all patients were from a single institute. When the EGFR mutated, its gene copy number was also examined.

Results: EGFR mutations were detected in five SCLCs (4%). The patients were mainly in the light smoker and histologic combined subtype. All but one of the tumors harbored gene amplifications. Notably, in three tumors of the combined SCLC subtype, both components of adenocarcinoma and SCLC harbored an EGFR mutation, whereas gene amplification was detected only in the adenocarcinoma component. A partial response was achieved in a patient (with an EGFR mutation) who was treated with gefitinib.

Conclusions: Although EGFR mutations are rare in SCLC, a combined subtype of SCLC with adenocarcinoma in light smokers may have a chance of harboring EGFR mutations. For patients with an EGFR mutation, EGFR tyrosine kinase inhibitor can be a treatment option. In terms of molecular pathogenesis, it is suggested that some SCLCs may have developed from pre-existing adenocarcinomas with EGFR mutations, but the development may not be simply linear, taking into consideration the discordant distribution of EGFR amplification.
A Phase I Trial of Pemetrexed Plus Gemcitabine Given Biweekly with B-Vitamin Support in Solid Tumor Malignancies or Advanced Epithelial Ovarian Cancer
Authors: Hensley Martee L. , Larkin Joseph , Fury Matthew , Gerst Scott , Tai D. Fritz , Sabbatini Paul , Konner Jason , Orlando Mauro , Goss Tiana L. , Aghajanian Carol A.
Published: October 2008

Purpose: To determine the maximally tolerated dose (MTD) of biweekly pemetrexed with gemcitabine plus B12 and folate supplementation in patients with advanced solid tumors and ovarian cancer.

Experimental Design: Patients with no prior pemetrexed or gemcitabine therapy enrolled in cohorts of three, expanding to six if dose-limiting toxicity (DLT) was observed. Pemetrexed, escalated from to 700 mg/m2, was given before gemcitabine 1,500 mg/m2 every 14 days. DLTs were grade 4 neutropenia lasting >7 days or febrile neutropenia, grade 4 or 3 thrombocytopenia (with bleeding), grade ≥3 nonhematologic toxicity, or treatment delay of ≥1 week due to unresolved toxicity.

Results: The ovarian cancer cohort enrolled 24 patients with unlimited prior cytotoxic chemotherapies. MTD was observed at pemetrexed 600 mg/m2, with 2 of 9 patients experiencing DLT. Most common grade 3 to 4 toxicities per patient were neutropenia (83%), leukopenia (67%), lymphopenia (73%), and febrile neutropenia (12%). Median cycle per patient was 8 (range, 1-16). Six of 21 (28%) patients had confirmed partial responses. Study protocol was modified for the solid tumor cohort (n = 30) to enroll patients with two or more prior cytotoxic regimens. MTD was observed at pemetrexed 500 mg/m2, with 1 of 9 patients experiencing DLT. Most common grade 3 to 4 toxicities per patient were neutropenia (63%), lymphopenia (43%), leukopenia (70%) and febrile neutropenia (6.6%). Median cycle per patient was 4 (range, 1-20). Three of 29 (10.3%) response-evaluable patients had confirmed partial responses: 2 squamous cell carcinomas of head and neck and 1 nasopharyngeal cancer.

Conclusion: MTDs for the solid tumor and ovarian cancer cohorts were reached at pemetrexed 500 and 600 mg/m2, respectively, given biweekly with gemcitabine 1,500 mg/m2.
Therapy of Advanced B-Lymphoma Xenografts with a Combination of 90Y-anti-CD22 IgG (Epratuzumab) and Unlabeled Anti-CD20 IgG (Veltuzumab)
Authors: Mattes M. Jules , Sharkey Robert M. , Karacay Habibe , Czuczman Myron S. , Goldenberg David M.
Published: October 2008

Purpose: Antibodies are effective therapeutic agents in cancer, but cures are rarely if ever obtained. Combination therapies are likely to be more effective than a single agent. In this study, the combination of a new unconjugated humanized anti-CD20 IgG, veltuzumab, with a 90Y-conjugated humanized antibody to CD22 (epratuzumab) was evaluated for the treatment of B-cell lymphoma in a nude mouse model system.

Experimental Design: Nude mice were grafted with the Ramos human B-lymphoma and treatment initiated when tumors were >0.1 cm3. In most experiments, mice were injected first with unconjugated anti-CD20, then with 90Y-anti-CD22 1 day later. Additional weekly injections of the unconjugated veltuzumab were administered for 3 weeks. Controls included a single agent only and a nonreactive control radiolabeled antibody.

Results: Unconjugated anti-CD20 veltuzumab alone did not have a significant therapeutic effect, even at a total dose of 2.5 mg per mouse. The 90Y-anti-CD22 epratuzumab alone induced marked regressions of all tumors, but they regrew in a few weeks. The combination of these agents cured ∼80% of the mice. A nonreactive control antibody labeled with 90Y, used without veltuzumab, had no therapeutic effect. The therapeutic effect of 90Y-epratuzumab required the maximum tolerated dose of radioactivity, which was 160 μCi per mouse.

Conclusions: These studies illustrate how combinations of unconjugated and radioconjugated antibodies against different B-cell markers can improve therapeutic outcome, and offer a new therapeutic paradigm for the treatment of B-cell lymphomas.
Therapeutic Potential of Replication-Selective Oncolytic Adenoviruses on Cells from Familial and Sporadic Desmoid Tumors
Authors: Peerlinck Inge , Amini-Nik Saeid , Phillips Robin K. , Iggo Richard , Lemoine Nicholas R. , Tejpar Sabine , Vassaux Georges
Published: October 2008

Purpose: Constitutive activation of the Wnt signaling pathway is a hallmark of many cancers and has been associated with familial and sporadic desmoid tumors. The aim of the present study is to assess the therapeutic potential of oncolytic adenoviruses selectively replicating in cells in which the Wnt signaling pathway is active on primary cells from desmoid tumors.

Experimental Design: Primary cells extracted from familial (n = 3) or sporadic (n = 3) desmoid tumors were cultured short term. Cancer cell survival and viral replication were measured in vitro upon infection with two different oncolytic adenoviruses targeting a constitutive activation of the Wnt signaling pathway. Adenoviral infectivity was also assessed.

Results: Although cells extracted from one sporadic desmoid tumor responded very well to the oncolytic action of the adenoviruses (<20% of viable cells upon infection at a multiplicity of infection of 10), cells from two tumor samples were totally resistant to the viral action. Cells from the remaining samples showed intermediate sensitivity to the oncolytic viruses. These effects were correlated to the level of infectivity of the cells. Finally, in responder cells, evidences of viral replication was observed.

Conclusions: Our experimental data suggest that the response of desmoid tumor cells to oncolytic adenovirus is neither correlated to the type of mutation activating the Wnt signaling pathway nor to the familial or sporadic nature of the tumor. In addition, they highlight the variability of infectivity of individual tumors and predict a great variability in the response to oncolytic adenoviruses.
Fluorescence In situ Hybridization Subgroup Analysis of TRIBUTE, a Phase III Trial of Erlotinib Plus Carboplatin and Paclitaxel in Non–Small Cell Lung Cancer
Authors: Hirsch Fred R. , Varella-Garcia Marileila , Dziadziuszko Rafal , Xiao Yun , Gajapathy Sujatha , Skokan Margaret , Lin Ming , O'Neill Vincent , Bunn Paul A.
Published: October 2008

Purpose: TRIBUTE was a phase III trial evaluating the addition of erlotinib to carboplatin and paclitaxel as a first-line treatment for advanced non–small cell lung cancer that did not meet its primary end point of improving overall survival. Here, we assess the value of using epidermal growth factor receptor (EGFR) gene copy number in tumor biopsy samples, as determined by fluorescence in situ hybridization (FISH), as a predictor of treatment outcome.

Methods: EGFR FISH analysis was done using LSI EGFR SpectrumOrange/CEP7 SpectrumGreen probe.

Results: Of 275 samples, 245 (89.1%) were successfully analyzed by FISH. One hundred (40.8%) of patients were EGFR FISH(+). Median overall survival was not different between FISH(+) and FISH(−) patients in either the chemotherapy+erlotinib arm or the chemotherapy+placebo arm. In FISH(+) patients, median time to progression (TTP) was 6.3 months in the erlotinib arm versus 5.8 months in the placebo arm (hazard ratio, 0.59; 95% confidence interval, 0.35-0.99; P = 0.0430); in FISH(−) patients, median TTP was 4.6 months versus 6.0 months (hazard ratio, 1.42; 95% confidence interval, 0.95-2.14; P = 0.0895; treatment interaction test, P = 0.007). After 6 months of treatment, a notable separation of the TTP curves in favor of erlotinib emerged. Objective response rates were 11.6% versus 29.8% in FISH(+) patients (chemotherapy+erlotinib arm versus chemotherapy+placebo arm; P = 0.0495) and 21.8% versus 25.4%, respectively, for FISH(−) patients (P = 0.6954).

Conclusions: EGFR gene copy number by FISH did not predict survival benefit. However, among EGFR FISH(+) patients, TTP was longer in patients who received erlotinib and continued to receive it after completing first-line therapy.
Effects of Manganese Superoxide Dismutase Silencing on Androgen Receptor Function and Gene Regulation: Implications for Castration-Resistant Prostate Cancer
Authors: Sharifi Nima , Hurt Elaine M. , Thomas Suneetha B. , Farrar William L.
Published: October 2008

Purpose: Advanced prostate cancer is first treated with androgen deprivation therapy. However, tumors become resistant to and grow despite castrate levels of testosterone. Growth and proliferation of CRPC is mediated by gain-of-function changes in the AR and AR reactivation. Expression of manganese superoxide dismutase (SOD2), which regulates cellular ROS, is markedly down-regulated in CRPC when compared with hormone-responsive tumors.

Experimental Design: Here, we knocked down SOD2 expression in AR-expressing LNCaP prostate cancer cells and determined gene expression changes, transcription factor binding, and AR transcription activity in SOD2 knockdown cells.

Results: SOD2 knockdown results in an increase in ROS. Gene expression changes induced by SOD2 knockdown results in the up-regulation of genes that are also androgen responsive and 46% of genes up-regulated 2-fold by the androgen ligand R1881 are also up-regulated to the same extent with SOD2 knockdown. The induction of many of these genes with SOD2 knockdown, such as VEGFA and FKBP5, is reversible with the antioxidant N-acetylcysteine, suggesting that this mechanism is directly linked to ROS. Furthermore, an array for transcription factor DNA-binding activity shows that SOD2 knockdown induces DNA binding by several transcription factors, including AR. SOD2 knockdown-induced AR activation was confirmed by electrophoretic mobility shift assay and luciferase activity, and both were readily reversible with N-acetylcysteine.

Conclusions: These findings show that down-regulation of SOD2 induces AR activity in a ROS-dependent manner, and suggest that there may be a role for antioxidant therapy in CRPC.
Zoledronic Acid Markedly Improves Bone Mineral Density for Patients with Monoclonal Gammopathy of Undetermined Significance and Bone Loss
Authors: Berenson James R. , Yellin Ori , Boccia Ralph V. , Flam Marshall , Wong Siu-Fun , Batuman Olcay , Moezi Mehdi M. , Woytowitz Donald , Duvivier Herbert , Nassir Youram , Swift Regina A.
Published: October 2008

Purpose: Patients with monoclonal gammopathy of undetermined significance (MGUS) have increased rates of bone resorption, osteopenia, osteoporosis, and risk of fractures. This study was undertaken to determine the efficacy and safety of zoledronic acid for patients with MGUS and enhanced bone loss.

Experimental Design: In this phase II open-label study, 54 patients with MGUS and osteopenia or osteoporosis were administered zoledronic acid 4 mg i.v. at 0, 6, and 12 months. The primary efficacy end point was bone mineral density, assessed using a dual-energy X-ray absorptiometry scan in the lumbar (L)-spine done at screening and at 13 months (1 month after the final zoledronic acid infusion).

Results: At study end for all patients (N = 54), L-spine T-scores improved by a median of +0.27 (range, −0.38 to +3.91), corresponding to a median increase in bone mineral density of +15.0% (range, −18.0% to +1,140.0%; P < 0.0001). Hip T-scores improved by a median of +0.10 (range, −2.40 to +2.03), corresponding to a median increase of +6.0% (range, −350.0% to +165.0%). During the study, no new fractures, osteonecrosis of the jaw, or significant renal adverse events were reported.

Conclusions: Zoledronic acid administered i.v. at a dosage of 4 mg every 6 months for three doses total was well-tolerated and substantially improved bone mineral density for patients with MGUS and bone loss. Zoledronic acid may be effective for the prevention of new fractures in this high-risk population.
Cotreatment with Vorinostat Enhances Activity of MK-0457 (VX-680) against Acute and Chronic Myelogenous Leukemia Cells
Authors: Fiskus Warren , Wang Yongchao , Joshi Rajeshree , Rao Rekha , Yang Yonghua , Chen Jianguang , Kolhe Ravindra , Balusu Ramesh , Eaton Kelly , Lee Pearl , Ustun Celalettin , Jillella Anand , Buser Carolyn A. , Peiper Stephen , Bhalla Kapil
Published: October 2008

Purpose: We determined the effects of vorinostat (suberoylanalide hydroxamic acid) and/or MK-0457 (VX-680), an Aurora kinase inhibitor on the cultured human (HL-60, OCI-AML3, and K562) and primary acute myelogenous leukemia (AML) and chronic myelogenous leukemia (CML), as well as on the murine pro-B BaF3 cells with ectopic expression of the unmutated and mutant forms of Bcr-Abl.

Experimental Design: Following exposure to MK-0457 and/or vorinostat, apoptosis, loss of viability, as well as activity and levels of Aurora kinase and Bcr-Abl proteins were determined.

Results: Treatment with MK-0457 decreased the phosphorylation of Aurora kinase substrates including serine (S)10 on histone H3 and survivin, and led to aberrant mitosis, DNA endoreduplication as well as apoptosis of the cultured human acute leukemia HL-60, OCI-AML3, and K562 cells. Combined treatment with vorinostat and MK-0457 resulted in greater attenuation of Aurora and Bcr-Abl (in K562) kinase activity and levels as well as synergistically induced apoptosis of OCI-AML3, HL-60, and K562 cells. MK-0457 plus vorinostat also induced synergistic apoptosis of BaF3 cells with ectopic overexpression of wild-type or mutant Bcr-Abl. Finally, cotreatment with MK-0457 and vorinostat induced more loss of viability of primary AML and imatinib-refractory CML than treatment with either agent alone, but exhibited minimal toxicity to normal CD34+ progenitor cells.

Conclusions: Combined in vitro treatment with MK-0457 and vorinostat is highly active against cultured and primary leukemia cells. These findings merit in vivo testing of the combination against human AML and CML cells, especially against imatinib mesylate–resistant Bcr-AblT315I–expressing CML Cells.
Androgen-Regulated and Highly Tumorigenic Human Prostate Cancer Cell Line Established from a Transplantable Primary CWR22 Tumor
Authors: Dagvadorj Ayush , Tan Shyh-Han , Liao Zhiyong , Cavalli Luciane R. , Haddad Bassem R. , Nevalainen Marja T.
Published: October 2008

Purpose: One of the major obstacles in understanding the molecular mechanisms underlying the transition of prostate cancer growth from androgen dependency to a hormone-refractory state is the lack of androgen-regulated and tumorigenic human prostate cancer cell lines.

Experimental Design: We have established and characterized a new human prostate cancer cell line, CWR22Pc, derived from the primary CWR22 human prostate xenograft tumors.

Results: The growth of CWR22Pc cells is induced markedly by dihydrotestosterone, and CWR22Pc cells express high levels of androgen receptor (AR) and prostate-specific antigen (PSA). Importantly, PSA expression in CWR22Pc cells is regulated by androgens. Stat5a/b, Stat3, Akt, and mitogen-activated protein kinase were constitutively active or cytokine inducible in CWR22Pc cells. The AR in CWR22Pc cells contains the H874Y mutation, but not the exon 3 duplication or other mutations. When inoculated subcutaneously into dihydrotestosterone-supplemented castrated nude mice, large tumors formed rapidly in 20 of 20 mice, whereas no tumors developed in mice without circulating dihydrotestosterone. Moreover, the serum PSA levels correlated with the tumor volumes. When androgens were withdrawn from the CWR22Pc tumors grown in nude mice, the tumors initially shrank but regrew back as androgen-independent tumors.

Conclusions: This androgen-regulated and tumorigenic human prostate cancer cell line provides a valuable tool for studies on androgen regulation of prostate cancer cells and on the molecular mechanisms taking place in growth promotion of prostate cancer when androgens are withdrawn from the growth environment. CWR22Pc cells also provide a model system for studies on the regulation of transcriptional activity of mutated H874YAR in a prostate cancer cell context.