bluuebunny/crossref_metadata_2025 huggingface dataset:
Blockade of Transforming Growth Factor-β Signaling Suppresses Progression of Androgen-Independent Human Prostate Cancer in Nude Mice
Authors: Zhang Fahao , Lee Juwon , Lu Shan , Pettaway Curtis A. , Dong Zhongyun
Published: September 2005

We investigated the role of transforming growth factor-β (TGF-β) signaling in the growth and metastasis of PC-3MM2 human prostate cancer cells. Highly metastatic PC-3MM2 human prostate cancer cells were engineered to constitutively overexpress a dominant-negative type II TGF-β receptor (DNR). Transfection of DNR had minimal direct effects on cell growth and attenuated TGF-β-induced cell growth inhibition and TGF-β1 production. There were no discernable differences in tumorigenicity (tumor incidence) among PC-3MM2 variants when the cells were implanted into the prostates of nude mice. Growth rate and metastatic incidence of DNR-engineered PC-3MM2 cells, however, were significantly reduced. Most cells in the control tumors were positively stained by an antibody to proliferation cell nuclear antigen and very few cells were stained by terminal deoxynucleotidyl transferase–mediated nick-end labeling (TUNEL). In sharp contrast, tumors formed by PC-3MM2-DNR cells contained fewer proliferation cell nuclear antigen–positive cells and many more TUNEL-positive cells. Staining with antibody against CD31 showed that control tumors contained more blood vessels than PC-3MM2-DNR tumors. Expression of interleukin-8 (IL-8) in tumors formed by PC-3MM2 cells was significantly reduced as revealed by both Northern blotting and ELISA. Finally, transfection of antisense IL-8 cDNA significantly reduced IL-8 production by PC-3MM2 cells and antisense IL-8-transfected PC-3MM2 cells grew slower in comparison with parental and control vector-transfected cells. Taken together, our data suggest that TGF-β signaling, by regulating IL-8 expression in tumor cells and hence tumor angiogenesis, is critical for progressive growth of PC-3MM2 cells in the prostate of nude mice.
Noninvasive Monitoring of Murine Tumor Blood Flow During and After Photodynamic Therapy Provides Early Assessment of Therapeutic Efficacy
Authors: Yu Guoqiang , Durduran Turgut , Zhou Chao , Wang Hsing-Wen , Putt Mary E. , Saunders H. Mark , Sehgal Chandra M. , Glatstein Eli , Yodh Arjun G. , Busch Theresa M.
Published: September 2005

Purpose: To monitor tumor blood flow noninvasively during photodynamic therapy (PDT) and to correlate flow responses with therapeutic efficacy.

Experimental Design: Diffuse correlation spectroscopy (DCS) was used to measure blood flow continuously in radiation-induced fibrosarcoma murine tumors during Photofrin (5 mg/kg)/PDT (75 mW/cm2, 135 J/cm2). Relative blood flow (rBF; i.e., normalized to preillumination values) was compared with tumor perfusion as determined by power Doppler ultrasound and was correlated with treatment durability, defined as the time of tumor growth to a volume of 400 mm3. Broadband diffuse reflectance spectroscopy concurrently quantified tumor hemoglobin oxygen saturation (SO2).

Results: DCS and power Doppler ultrasound measured similar flow decreases in animals treated with identical protocols. DCS measurement of rBF during PDT revealed a series of PDT-induced peaks and declines dominated by an initial steep increase (average ± SE: 168.1 ± 39.5%) and subsequent decrease (59.2 ± 29.1%). The duration (interval time; range, 2.2-15.6 minutes) and slope (flow reduction rate; range, 4.4 -45.8% minute−1) of the decrease correlated significantly (P = 0.0001 and 0.0002, r2 = 0.79 and 0.67, respectively) with treatment durability. A positive, significant (P = 0.016, r2 = 0.50) association between interval time and time-to-400 mm3 was also detected in animals with depressed pre-PDT blood flow due to hydralazine administration. At 3 hours after PDT, rBF and SO2 were predictive (P ≤ 0.015) of treatment durability.

Conclusion: These data suggest a role for DCS in real-time monitoring of PDT vascular response as an indicator of treatment efficacy.
Spontaneous Regression of High-Grade Cervical Dysplasia: Effects of Human Papillomavirus Type and HLA Phenotype
Authors: Trimble Cornelia L. , Piantadosi Steven , Gravitt Patti , Ronnett Brigitte , Pizer Ellen , Elko Andrea , Wilgus Barbara , Yutzy William , Daniel Richard , Shah Keerti , Peng Shiwen , Hung Chienfu , Roden Richard , Wu Tzyy Choou , Pardoll Drew ,   The Johns Hopkins Medical Institutions, Baltimore, MD
Published: September 2005

Purpose: Persistent infection with oncogenic human papillomaviruses (HPV) plays a central etiologic role in the development of squamous carcinomas of the cervix and their precursor lesions, cervical intraepithelial neoplasias (CIN). We carried out a prospective observational cohort study evaluating known, quantifiable prognostic variables of clinical behavior in women with high-grade cervical lesions.

Experimental Design: Our study cohort included healthy women with high-grade cervical lesions (CIN2/3) with residual visible lesions after colposcopically directed biopsy. We prospectively followed 100 women over 15 weeks before standard resection. HPV typing was done using PCR and a reverse line blot detection method.

Results: The rate of spontaneous histologic regression, defined as (CIN1 or less at resection) was 28%. The overall rate of HPV infection was 100%. HPV16 was identified in 68% of the lesions. Women with HPV16 only were significantly less likely to regress, compared with women with HPV types other than HPV16 (odds ratio, 0.342; 95% confidence interval, 0.117-0.997; P = 0.049). In the cohort with HPV16 only, patients who had an HLA*A201 allele had similar outcomes to those who did not carry A201. However, among patients with HPV types other than HPV16, the HLA*A201 allele interaction was significant; patients with HLA*A201 were the least likely to resolve.

Conclusions: CIN2/3 lesions associated with HPV16 alone are significantly less likely to resolve spontaneously than those caused by other types. Interactions among HPV type, HLA type, and regression rate support a role for HLA-restricted HPV-specific immune responses in determining disease outcome.
Cyr61 Induces Gastric Cancer Cell Motility/Invasion via Activation of the Integrin/Nuclear Factor-κB/Cyclooxygenase-2 Signaling Pathway
Authors: Lin Ming-Tsai , Zuon Chung-Yaou , Chang Cheng-Chi , Chen Szu-Ta , Chen Chih-Ping , Lin Been-Ren , Wang Ming-Yang , Jeng Yung-Ming , Chang King-Jen , Lee Po-Huang , Chen Wei-Jao , Kuo Min-Liang
Published: September 2005

Purpose: Cysteine-rich 61 (Cyr61/CCN1) is involved in many different types of tumor development and progression. Nonetheless, the role of Cyr61 in human gastric cancer has not yet been fully characterized.

Experimental design: We addressed the issue by immunohistochemical staining of 81 gastric adenocarcinoma specimens. Liposome-mediated transfection was used to introduce a Cyr61 expression vector into gastric cancer AGS cell lines. Transfectants were tested in invasion assay by a Boyden chamber. Furthermore, a cyclooxygenase-2 (COX-2) reporter assay and gel mobility shift assay were done to investigate the potential signal pathway of Cyr61.

Results: Patients with gastric adenocarcinoma whose tumor displayed high expression of Cyr61 correlated well with aggressive lymph node metastasis, more advanced tumor stage, histologic diffuse type, and early recurrence. Stable transfection of Cyr61 into the AGS cell line strongly enhanced its invasive activity. The overexpression of Cyr61 into AGS cells significantly increased the expression of COX-2 mRNA, protein, and enzymatic activity. Gel mobility shift assays further showed that the nuclear factor-κB (NF-κB) pathway was evidently activated in Cyr61-expressing AGS cells. Function-neutralizing antibody to αvβ3 but not αvβ5 effectively suppressed Cyr61-mediated NF-κB activation, COX-2 gene expression, and cell invasiveness.

Conclusions: Cyr61 may contribute to the malignant progression of gastric cancer by promoting tumor cell motility/invasion through up-regulation of the functional COX-2 via an integrin αvβ3/NF-κB-dependent pathway.
A Phase I Clinical Trial of the Sequential Combination of Irinotecan Followed by Flavopiridol
Authors: Shah Manish A. , Kortmansky Jeremy , Motwani Monica , Drobnjak Marija , Gonen Mithat , Yi Sandy , Weyerbacher Amanda , Cordon-Cardo Carlos , Lefkowitz Robert , Brenner Baruch , O'Reilly Eileen , Saltz Leonard , Tong William , Kelsen David P. , Schwartz Gary K.
Published: September 2005

Purpose: Flavopiridol potently enhances the effect of irinotecan with cures in colorectal cancer xenografts, and is associated with modulation of several molecular targets, including p21, Differentiation-related gene 1 (Drg1), and p53. We initiated a phase I trial of the sequential combination of irinotecan followed by flavopiridol to determine the maximal tolerated dose of this combination therapy.

Patients and Methods: Forty-five patients with advanced solid tumors were enrolled. Irinotecan was administered first (100 or 125 mg/m2) followed 7 hours later by escalating flavopiridol (10-70 mg/m2) given weekly over 1 hour for 4 of 6 weeks. At the maximal tolerated dose, the pharmacokinetic analysis was expanded and pre- and posttreatment tumor biopsies were done.

Results: At irinotecan 100 mg/m2, dose-limiting diarrhea and myelosuppression were observed with flavopiridol 70 mg/m2. At irinotecan 125 mg/m2, we observed dose-limiting hyperbilirubinemia, fatigue, and myelosuppression at flavopiridol 60 mg/m2. Peak flavopiridol concentrations of ≥2 μmol/L were achieved above flavopiridol 50 mg/m2. No significant pharmacokinetic interactions with irinotecan were noted. Baseline serum bilirubin significantly predicted cycle 1 dose-limiting toxicity and neutropenia. We observed partial responses in three patients and prolonged stable disease (i.e., >6 months) in 36% of patients including adrenocortical cancer and hepatocellular cancer. Patients with wild-type p53 and either no change or low posttreatment biopsy p21 and a decrease in Drg1 expression showed stable or responsive disease to the combination therapy.

Conclusions: The recommended phase II dose with irinotecan 100 mg/m2 is flavopiridol 60 mg/m2 and with irinotecan 125 mg/m2 is flavopiridol 50 mg/m2. Toxicity can be predicted by baseline bilirubin. Clinical activity is encouraging and may correlate to changes in p21 and Drg1 levels in patients with wild type p53 tumors following therapy.
Treatment of Human Tumor Xenografts with Monoclonal Antibody 806 in Combination with a Prototypical Epidermal Growth Factor Receptor–Specific Antibody Generates Enhanced Antitumor Activity
Authors: Perera Rushika M. , Narita Yoshitaka , Furnari Frank B. , Gan Hui K. , Murone Carmel , Ahlkvist Marika , Luwor Rodney B. , Burgess Antony W. , Stockert Elisabeth , Jungbluth Achim A. , Old Lloyd J. , Cavenee Webster K. , Scott Andrew M. , Johns Terrance G.
Published: September 2005

Monoclonal antibody (mAb) 806 is a novel epidermal growth factor receptor (EGFR) antibody with significant antitumor activity that recognizes a mutant EGFR commonly expressed in glioma known as delta2-7 EGFR (de2-7 EGFR or EGFRvIII) and a subset of the wild-type (wt) EGFR found in cells that overexpress the receptor. We have used two human xenograft mouse models to examine the efficacy of mAb 806 in combination with mAb 528, a prototypical anti-EGFR antibody with similar specificity to cetuximab. Treatment of nude mice, bearing s.c. or i.c. tumor human xenografts expressing the wt or de2-7 EGFR, with mAbs 806 and 528 in combination resulted in additive and in some cases synergistic, antitumor activity. Interestingly, mAb 528 was also effective against xenografts expressing the ligand independent de2-7 EGFR when used as a single agent, showing that its antitumor activity is not merely mediated through inhibition of ligand binding. When used as single agents, neither mAbs 806 or 528 induced down-regulation of the de2-7 EGFR either in vitro or in vivo. In contrast, the combination of antibodies produced a rapid and dramatic decrease in the total cell surface de2-7 EGFR both in vitro and in xenografts. Consistent with this decrease in total cell surface de2-7 EGFR, we observed up-regulation of the cell cycle inhibitor p27KIP1 and a decrease in tumor cell proliferation as measured by Ki-67 immunostaining when the antibodies were used in combination in vivo. Thus, mAb 806 can synergize with other EGFR-specific antibodies thereby providing a rationale for its translation into the clinic.
Tumor Vascular Response to Photodynamic Therapy and the Antivascular Agent 5,6-Dimethylxanthenone-4-Acetic Acid: Implications for Combination Therapy
Authors: Seshadri Mukund , Spernyak Joseph A. , Mazurchuk Richard , Camacho Susan H. , Oseroff Allan R. , Cheney Richard T. , Bellnier David A.
Published: September 2005

Purpose: Photodynamic therapy (PDT) is a clinically approved treatment for a variety of solid malignancies. 5,6-Dimethylxanthenone-4-acetic acid (DMXAA) is a potent vascular targeting agent that has been shown to be effective against a variety of experimental rodent tumors and xenografts and is currently undergoing clinical evaluation. We have previously reported that the activity of PDT against transplanted mouse tumors is selectively enhanced by DMXAA. In the present study, we investigated the in vivo tumor vascular responses to the two treatments given alone and in combination.

Experimental Design: Vascular responses to (i) four different PDT regimens using the photosensitizer 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a (HPPH) at two different fluences (128 and 48 J/cm2) and fluence rates (112 and 14 mW/cm2), (ii) 5-aminolevulinic acid (ALA)–sensitized PDT (135 J/cm2 at 75 mW/cm2), (iii) DMXAA at a high (30 mg/kg) and low dose (25 mg/kg), and (iv) the combination of HPPH-PDT (48 J/cm2 at 112 mW/cm2) and low-dose DMXAA were studied in BALB/c mice bearing Colon-26 tumors.

Results: PDT-induced changes in vascular permeability, determined using noninvasive magnetic resonance imaging with a macromolecular contrast agent, were regimen dependent and did not predict tumor curability. However, a pattern of increasing (4 hours after treatment) and then decreasing (24 hours after) contrast agent concentrations in tumors, seen after high-dose DMXAA or the combination of PDT and low-dose DMXAA, was associated with long-term cure rates of >70%. This pattern was attributed to an initial increase in vessel permeability followed by substantial endothelial cell damage (CD31 immunohistochemistry) and loss of blood flow (fluorescein exclusion assay). Low dose–rate PDT, regardless of the delivered dose, increased the level of magnetic resonance contrast agent in peritumoral tissue, whereas treatment with either DMXAA alone, or PDT and DMXAA in combination resulted in a more selective tumor vascular response.

Conclusions: The observed temporal and spatial differences in the response of tumor vessels to PDT and DMXAA treatments could provide valuable assistance in the optimization of scheduling when combining these therapies. The combination of PDT and DMXAA provides therapeutically synergistic and selective antitumor activity. Clinical evaluation of this combination is warranted.
The Role of Gefitinib in Lung Cancer Treatment
Authors: Giaccone Giuseppe
Published: September 2005

Gefitinib (Iressa) is a novel targeted therapy that inhibits the tyrosine kinase activity of the epidermal growth factor receptor by competitively blocking the ATP binding site. In preclinical studies gefitinib has shown potent activity in a number of tumor models, including several lung cancer cell lines and xenografts. Two large randomized Phase II studies (IDEAL 1 and IDEAL 2) in pretreated non-small cell lung cancer reported a response rate approaching 20% in second-line patients and ∼10% in those pretreated with two or more chemotherapy regimens. The median survival in these two studies approached 6–8 months. As a first-line therapy, gefitinib has been assessed in combination with two different chemotherapy regimens in two large randomized studies (INTACT 1 and INTACT 2). Both studies failed to show an improvement in survival on a total patient accrual of >1000 patients in each study. Other end points (e.g., time to progression and response rate) were also not improved by the addition of gefitinib. Additional studies are indicated to assess the possible role of gefitinib in the maintenance of patients who received chemotherapy or chemoradiotherapy. Studies investigating gefitinib as first-line monotherapy are also required.
The Biology of Epidermal Growth Factor Receptor in Lung Cancer
Authors: Scagliotti Giorgio V. , Selvaggi Giovanni , Novello Silvia , Hirsch Fred R.
Published: September 2005

The prognostic significance of epidermal growth factor receptor (EGFR) expression in lung cancer and, more importantly, its ability to predict response to anti-EGFR therapies, are currently subjects of active research. In a meta-analysis, EGFR overexpression confirmed a worse prognosis (HR 1.13) in eight studies using immunohistochemistry, although cutoff values were generally selected arbitrarily by investigators. Most applied clinical research on the EGFR has been focused on the overexpression of the receptor, whereas less research has addressed the potential role of other mechanisms of increased signaling or of nonmembrane-bound events. The emerging concept of EGFR signaling reveals a multilayered network that allows for horizontal interactions and permits multiple combinatorial responses that may explain the specificity of cellular outcomes to receptor activation. New technologies such as nucleotide arrays and proteomics will help to elucidate the issue by providing information on how EGFR signaling may affect the expression of genes and proteins in cancer cells.
Pemetrexed (ALIMTA), A Novel Multitargeted Antineoplastic Agent
Authors: Adjei Alex A.
Published: September 2005

Pemetrexed (ALIMTA, LY231514, MTA) is a novel antimetabolite that inhibits at least three enzymes involved in the folate pathway. These enzymes are thymidylate synthase, dihydrofolate reductase, and glycinamide ribonucleotide formyltransferase. Pemetrexed has demonstrated clinical activity in non-small cell lung cancer as well as in a broad array of other solid tumors, including mesothelioma, breast, colorectal, bladder, cervical, gastric and pancreatic cancer. In non-small cell lung cancer, single-agent activity has been documented in the first- and second-line settings in Phase II and Phase III trials. Promising activity has also been demonstrated when pemetrexed is combined with platinum compounds (cisplatin, carboplatin, and oxaliplatin), vinorelbine, and gemcitabine. Low level dietary supplement of folic acid and vitamin B12 has significantly decreased the mucosal and bone marrow toxicity of pemetrexed without compromising its antitumor effect.
Bronchioloalveolar Carcinoma
Authors: Gandara David R. , West Howard , Chansky Kari , Davies Angela M. , Lau Derick H. M. , Crowley John , Gumerlock Paul H. , Hirsch Fred R. , Franklin Wilbur A.
Published: September 2005

Bronchioloalveolar carcinoma (BAC) is a previously uncommon subset of non-small cell lung cancer (NSCLC) with unique epidemiology, pathology, clinical features, radiographic presentation, and natural history compared with other NSCLC subtypes. Recent data suggest that the incidence of BAC is increasing, notably in younger nonsmoking women. Despite reports of prolonged survival after repeated surgical resection of multifocal lesions and slow growth kinetics, advanced bilateral or recurrent diffuse BAC remains incurable, with the vast majority of patients dying of respiratory failure or intercurrent pneumonia within 5 years. Limited data suggest that chemotherapy may yield poor results in BAC. However, anecdotal reports of prolonged complete response to tyrosine kinase inhibitors of the epidermal growth factor receptor (EGFR), a member of the human epidermal growth factor receptor (erbB) family, have raised considerable interest in studying this NSCLC subset. Here we present clinical data and preliminary results of correlative science studies analyzing human epidermal growth factor receptor pathways from the following two prospective Southwest Oncology Group clinical trials performed in advanced stage BAC: S9714 testing a 96-h continuous infusion of paclitaxel (Taxol) and S0126 evaluating the small molecule EGFR inhibitor gefitinib (ZD1839 or Iressa). These studies provide a biological rationale for investigating BAC as a model of predictive markers of EGFR inhibition.
The Role of Erlotinib (Tarceva, OSI 774) in the Treatment of Non-Small Cell Lung Cancer
Authors: Perez-Soler Roman
Published: September 2005

Erlotinib (Tarceva) is a reversible and highly specific inhibitor of epidermal growth factor receptor (EGFR) tyrosine kinase. Phase I studies established a fixed daily oral dose of 150 mg as the recommended dose for Phase II studies. Using this dose and schedule, the response rate in a group of 57 patients with EGFR-positive non-small cell lung cancer after failure of platinum-containing chemotherapy was 12%. The median survival was 8.4 months, and the 1-year survival was 40%. Occurrence and severity of rash were correlated with an improved survival independently of performance status. Another ongoing Phase II study in 50 patients with bronchoalveolar carcinoma has shown a response rate of 26%. Results from two Phase III front-line studies in combination with chemotherapy, TALENT and TRIBUTE, have been recently reported. The addition of erlotinib did not improve response rate, time to progression, or survival. Efforts in the continued development of erlotinib should be focused on the following: (a) investigating the reasons for the lack of relationship between EGFR expression and clinical outcome; (b) the reasons for the failure of the front-line combination trials; and (c) confirming the rash/clinical outcome relationship. Progress in these tasks will allow a better selection of patients who can benefit from this therapy, permit the development of more effective combination schedules with cytotoxics, and define whether this agent should be used at the optimal biological dose or at the maximum-tolerated dose.
Molecularly Targeted Approaches to the Chemoprevention of Lung Cancer
Authors: Khuri Fadlo R. , Cohen Victor
Published: September 2005

Large, randomized trials have been conducted in the primary prevention of lung cancer using micronutrients or derivative agents for which epidemiological data suggested a potential role in lung cancer prevention. The disappointing primary prevention trials of β-carotene, α-tocopherol, and retinyl palmitate have led to the development of a more compact, biomarker-driven series of translational trials of lung cancer prevention that target reversal of premalignancy as the primary end point. Serial trials of 13-cis-retinoic acid (isotretinoin) and other retinoids have failed to show a difference in reversal of premalignancy in active smokers or in second primary tumor prevention. However, a trial of 9-cis-retinoic acid, a pan retinoid/rexinoid agonist, showed up-regulation of retinoic acid receptor β (RAR-β), a potentially important intermediate marker of response in lung cancer premalignancy. Other planned or ongoing trials currently target important molecular markers of lung carcinogenesis and progression including cyclooxygenase-2, the ras-signaling pathway through farnesyl transferase inhibitors, and the tyrosine kinase/epidermal growth factor receptor pathway (gefitinib, erlotinib). Early results of bioadjuvant trials in head and neck cancer suggest that combination chemoprevention will ultimately be an important option.
Long-Term Exposure to Tamoxifen Induces Hypersensitivity to Estradiol
Authors: Berstein Lev M. , Wang Ji-Ping , Zheng Hong , Yue Wei , Conaway Mark , Santen Richard J.
Published: September 2005

In women with hormone-dependent breast cancer, tamoxifen (TAM) frequently induces tumor regression, but regrowth occurs with continuation of antiestrogen therapy. Studies of breast xenografts in nude mice suggest that this secondary resistance to TAM may reflect the development of enhanced sensitivity to the estrogenic properties of TAM. In the current study, we examined the hypothesis that TAM could also induce a state of hypersensitivity to estradiol (E2) itself. Oophorectomized nude mice with MCF-7 cell xenografts received 25-mg implants of TAM [long-term TAM treated (LTTT) mice] or cholesterol (C-MCF-7) over a 5-month period (phase 1). The LTTT group regressed to a lesser extent than did C-MCF-7 tumors. After 4 months of TAM exposure, the LTTT tumors begin to regrow, as did the C-MCF-7, as assessed by slope analysis. At 5 months, TAM or vehicle implants were removed, and the LTTT and C-MCF-7 subgroups were given vehicle or two doses of E2 to test estrogen sensitivity (phase 2). We used our “E2 clamp” technique to maintain levels of plasma E2 at either 1.25 or 20 pg/ml. Neither group responded to the very low concentrations of E2 (1.25 pg/ml) or vehicle. The LTTT tumors but not C-MCF-7 tumors exhibited a growth response on exposure to 20 pg/ml E2 during 7 weeks, as demonstrated with mixed models analysis. These studies provide evidence that long-term TAM exposure enhances sensitivity to the estrogenic effects of TAM and also to E2 itself.
Adenovirus-Mediated Retinoblastoma 94 Gene Transfer Induces Human Pancreatic Tumor Regression in a Mouse Xenograft Model
Authors: Roig Josep Maria , Molina Miguel Angel , Cascante Anna , Calbó Joaquim , Carbó Neus , Wirtz Uwe , Sreedharan Sunil , Fillat Cristina , Mazo Adela
Published: September 2005

Purpose: Gene transfer of a truncated variant of the retinoblastoma (RB) gene encoding a Mr 94,000 protein that lacks the NH2-terminal 112 amino acid residues, termed RB94, has been shown to inhibit proliferation of several human tumor cell types. We have assessed its therapeutic effectiveness on pancreatic cancer, one of the most aggressive and therapy-resistant types of cancer. For this purpose, preclinical studies aimed to evaluate the therapeutic potential of RB94 gene transfer in pancreatic cancer were carried out.

Experimental Design: We have compared the antiproliferative effects of adenovirus-mediated gene transfer of RBwt and RB94 at the in vitro and in vivo levels in three RB-positive human pancreatic tumor cell lines: (a) NP-9; (b) NP-18; and (c) NP-31. We have also examined their effects on cell cycle and their capacity to induce apoptosis.

Results: In vitro results indicate that RB94 gene transfer has stronger antiproliferative effects compared with RBwt. RB94 transduction correlated with accumulation at the S-G2 phase of the cell cycle in the three cell lines tested and induction of apoptosis in two of them. In vivo studies show significant decreases in the growth rate of tumors treated with Ad-RB94 when compared with those treated with Ad-RBwt. Moreover, terminal deoxynucleotidyl transferase-mediated nick end labeling analyses of Ad-RB94-treated tumor sections revealed that only RB94 is able to significantly induce apoptosis.

Conclusions: RB94 gene expression has antiproliferative effects also in human pancreatic tumor cells, being more effective than wild-type RB in preventing tumor growth.
Reduced Growth, Increased Vascular Area, and Reduced Response to Cisplatin in CD13-Overexpressing Human Ovarian Cancer Xenografts
Authors: van Hensbergen Yvette , Broxterman Henk J. , Rana Sareena , van Diest Paul J. , Duyndam Monique C. A. , Hoekman Klaas , Pinedo Herbert M. , Boven Epie
Published: September 2005

Purpose: Expression of aminopeptidase N/CD13 can be detected in several solid tumor types. Thus far, the role of CD13 in ovarian cancer has not been studied. We have investigated the expression pattern and biological function of CD13 in ovarian cancer.

Experimental Design: First, we studied the expression of CD13 in ovarian cancer tissue of 15 patients representing three different histological types (5 patients each) by immunohistochemistry. We then stably transfected the IGROV-1 human ovarian cancer cell line with a CD13 expression vector and examined the biological effect of CD13 in vitro and in vivo.

Results: The expression of CD13 in ovarian cancer was associated with the histological subtype: CD13 expression in tumor cells was observed in 80–100% of the patients with a serous or mucinous carcinoma and in only 20% of the clear cell carcinoma patients. In all patients’ tumor samples, CD13-positive blood vessels were present. CD13 overexpression in IGROV-1 cells did not affect in vitro cell growth and sensitivity to doxorubicin, cisplatin, or gemcitabine. CD13 overexpression reduced invasion in Matrigel, which appeared to be independent of the aminopeptidase activity of CD13. Furthermore, the growth rate of IGROV-1/CD13 xenografts was reduced. The area of the vessel lumens was enlarged in a small percentage of vessels in the CD13-overexpressing xenografts. In addition, the CD13-overexpressing tumors were less sensitive to cisplatin.

Conclusions: CD13 is expressed in tumor as well as endothelial cells in human ovarian cancer. Our results suggest that CD13 overexpression affects ovarian cancer growth, vascular architecture, and response to chemotherapy. Further elucidation of the mechanism of the observed effects of CD13 is warranted to better understand its role in the pathophysiology of ovarian cancer.
A Phase II Trial with Pharmacodynamic Endpoints of the Proteasome Inhibitor Bortezomib in Patients with Metastatic Colorectal Cancer
Authors: Mackay Helen , Hedley David , Major Pierre , Townsley Carol , Mackenzie Mary , Vincent Mark , Degendorfer Pam , Tsao Ming-Sound , Nicklee Trudey , Birle Diana , Wright John , Siu Lillian , Moore Malcolm , Oza Amit
Published: September 2005

Purpose: To evaluate the effects of the proteasome inhibitor bortezomib on tumor growth in patients with advanced colorectal cancer, and to explore the relationship between correlative studies and clinical outcome.

Design: Bortezomib (1.3 mg/m2) was administered i.v. on days 1, 4, 8, and 11 of a 21-day cycle. Tumor response was assessed after every two cycles. Tumor biopsies were done prior to treatment and on day 9 of the first treatment cycle. Biopsies were examined for Ser32/36-IκB, Ser276-nuclear factor κB (NFκB), hypoxia-inducible factor-1α (HIF-1α), carbonic anhydrase IX (CAIX), p53, and microvessel density using immunohistochemistry.

Results: Nineteen patients received 42 cycles (range 1-4) of bortezomib. No objective response was seen; three patients had stable disease at cycle 2, two patients had progressive disease after cycle 1, and 11 patients had progressive disease at cycle 2. Of the three patients with stable disease, one had progressive disease after cycle 4, and two were withdrawn due to toxicity. The median time to progression was 5.1 weeks (95% confidence interval, 5.1-11.1 weeks). There was a significant increase in the expression of HIF-1α relative to its transcriptional target CAIX following bortezomib, and a similar effect was also observed in a companion study using a human tumor xenograft model. Expression of p53, Ser276-NFκB, and Ser32/36-IκB was unchanged.

Conclusion: Single agent bortezomib is inactive in metastatic colorectal cancer. Using this regimen, there was no detectable effect on NFκB, but a significant accumulation of HIF-1α was seen relative to CAIX. This suggests that proteasome inhibition alters the response to tumor hypoxia, and further investigation of this effect is indicated.
Critical Role of Peroxisome Proliferator-Activated Receptor γ on Anoikis and Invasion of Squamous Cell Carcinoma
Authors: Masuda Tomotake , Wada Koichiro , Nakajima Atsushi , Okura Masaya , Kudo Chiho , Kadowaki Takashi , Kogo Mikihiko , Kamisaki Yoshinori
Published: September 2005

Purpose: Peroxisome proliferator-activated receptor γ (PPARγ) plays a important role in various physiological functions. We examined whether PPARγ is expressed in primary squamous cell carcinoma and lymph node metastasis and whether PPARγ is a potential target for tumor therapy.

Experimental Design and Results: A high-level expression of PPARγ was observed in tumor cells of human primary squamous cell carcinoma, lymph node metastasis, and squamous cell carcinoma cell lines. Treatment with PPARγ-specific antagonists, but not agonists, caused apoptotic cell death on squamous cell carcinoma cell lines in a concentration-dependent manner. Small interfering RNA for PPARγ also inhibited cell adhesion and growth of squamous cell carcinomas. The phosphorylation of focal adhesion kinase (FAK) was decreased by treatment with PPARγ antagonists, and resulted in decreases in phosphorylation of Erk and mitogen-activated protein kinase. Furthermore, PPARγ antagonists decreased the adhesion of squamous cell carcinomas into fibronectin-coated plates, indicating the inhibition of interaction between squamous cell carcinomas and fibronectin. Expression of integrin α5, a counter adhesion molecule for fibronectin, was inhibited by the treatment with PPARγ antagonists. These results indicate that the decrease in integrin α5 and following inhibition of cell adhesion may cause the inhibition of FAK signaling pathways. PPARγ antagonists also strongly inhibited invasion of squamous cell carcinoma via down-regulation of CD151 expression.

Conclusions: The cell death caused by the PPARγ antagonists was a result of direct interference with cell adhesion “anoikis” involving intracellular FAK signaling pathways. These results imply a potentially important and novel role for the inhibition of PPARγ function via the use of specific antagonists in the treatment of squamous cell carcinoma and the prevention of tumor invasion and metastasis.
S100P Promotes Pancreatic Cancer Growth, Survival, and Invasion
Authors: Arumugam Thiruvengadam , Simeone Diane M. , Van Golen Kenneth , Logsdon Craig D.
Published: September 2005

Purpose: In the current study, we examined the functional significance and mechanism of action of S100P in pancreatic cancer cells.

Experimental Design: S100P levels were increased in Panc-1 cells, which do not express S100P, by transfection with an S100P cDNA and S100P levels were reduced in BxPC3 cells, which express high levels of S100P, by small interfering RNA gene silencing. Effects of these manipulations on cell proliferation, resistance to apoptotic insults, cell migration, and invasion were estimated in vitro using standard assays. The influences of S100P on tumor growth in vivo were studied using xenograft mouse models. To identify the mechanisms involved in these responses, coimmunoprecipitation studies were conducted with S100P with receptor for advanced glycation end products (RAGE) and the effects of inhibiting RAGE using an antagonistic peptide were analyzed.

Results: S100P levels correlated with the rates of cell proliferation, survival, migration, and invasion in both cell models in vitro. In vivo, increased S100P levels increased the growth of tumors in mice with s.c.-implanted Panc-1 cells and decreased S100P levels decreased tumor growth after orthotopic implantation of BxPC-3 cells. A direct interaction between S100P and RAGE was indicated by coimmunoprecipitation of these molecules from pancreatic cancer cells. A RAGE antagonist peptide inhibited this interaction and also inhibited the biological effects of S100P on these cells in vitro.

Conclusions: These data suggest that S100P plays a major role in the aggressiveness of pancreatic cancer that is likely mediated by its ability to activate RAGE. Thus, interference with S100P may provide a novel approach for treatment of pancreatic cancer.
Phase I Clinical Trial of BMS-247550, A Derivative of Epothilone B, Using Accelerated Titration 2B Design
Authors: Gadgeel Shirish M. , Wozniak Antoinette , Boinpally Ramesh R. , Wiegand Richard , Heilbrun Lance K. , Jain Vikas , Parchment Ralph , Colevas Dimitrios , Cohen Marvin B. , LoRusso Patricia M.
Published: September 2005

Purpose: BMS-247550 is a semisynthetic derivative of epothilone B with mechanism of action analogous to paclitaxel. It has shown impressive antitumor activity in preclinical studies including in taxane-resistant models. We conducted a phase I trial, based on accelerated titration “2B” design, of BMS-247550 given as a 1-hour infusion every 3 weeks.

Experimental Design: Seventeen patients (M:F, 10:7; median age, 54 years; performance status, 0-2) were treated on the trial. Forty-five cycles (1-9 cycles) of BMS-247550 were given at dosages ranging from 7.4 to 56 mg/m2. All patients received prophylaxis for hypersensitivity reactions, related to Cremophor-EL, with steroids and histamine antagonists.

Results: First-course dose-limiting toxicity (DLT) was observed in two of three patients at 56 mg/m2 (neutropenic sepsis, prolonged grade 4 neutropenia) and in one of six patients at 40 mg/m2. Nonhematologic grade 3 to 4 toxicities observed were emesis and fatigue and they occurred only at 56 mg/m2. Grade 1 to 2 peripheral neuropathy was also observed. Other grade 1 to 2 toxicities were myalgias, arthralgias, rash, hand/foot syndrome, and mucositis. AUC and Cmax seemed proportional to the dose and the DLT. Development of neutropenia with BMS-247550 is related to the duration of drug exposure above a threshold.

Conclusions: The maximum tolerated dose (MTD) of BMS-247550 is 40 mg/m2 given every 3 weeks. Neutropenia is the DLT. The accelerated titration “2B” design may help in determining MTD with fewer patients enrolled and more being treated closer to the MTD. However, the accelerated titration design did not seem to shorten the study duration.
Identification of a Novel Homozygous Deletion Region at 6q23.1 in Medulloblastomas Using High-Resolution Array Comparative Genomic Hybridization Analysis
Authors: Hui Angela B.Y. , Takano Hirokuni , Lo Kwok-Wai , Kuo Wen-Lin , Lam Cleo N.Y. , Tong Carol Y.K. , Chang Qing , Gray Joe W. , Ng Ho-Keung
Published: September 2005

Purpose: The aim of this study is to comprehensively characterize genome copy number aberrations in medulloblastomas using high-resolution array comparative genomic hybridization.

Experimental Design: High-density genomic arrays containing 1,803 BAC clones were used to define recurrent chromosomal regions of gains or losses throughout the whole genome of medulloblastoma. A series of 3 medulloblastoma cell lines and 16 primary tumors were investigated.

Results: The detected consistent chromosomal aberrations included gains of 1q21.3-q23.1 (36.8%), 1q32.1 (47.4%), 2p23.1-p25.3 (52.6%), 7 (57.9%), 9q34.13-q34.3 (47.4%), 17p11.2-q25.3 (89.5%), and 20q13.31-q13.33 (42.1%), as well as losses of 3q26.1 (57.9%), 4q31.23-q32.3 (42.1%), 6q23.1-25.3 (57.9%), 8p22-23.3 (79%), 10q24.32-26.2 (57.9%), and 16q23.2-q24.3 (63.2%). One of the most notable aberrations was a homozygous deletion on chromosome 6q23 in the cell line DAOY, and single copy loss on 30.3% primary tumors. Further analyses defined a 0.887 Mbp minimal region of homozygous deletion at 6q23.1 flanked by markers SHGC-14149 (6q22.33) and SHGC-110551 (6q23.1). Quantitative reverse transcription-PCR analysis showed complete loss of expression of two genes located at 6q23.1, AK091351 (hypothetical protein FLJ34032) and KIAA1913, in the cell line DAOY. mRNA levels of these genes was reduced in cell lines D283 and D384, and in 50% and 70% of primary tumors, respectively.

Conclusion: Current array comparative genomic hybridization analysis generates a comprehensive pattern of chromosomal aberrations in medulloblastomas. This information will lead to a better understanding of medulloblastoma tumorigenesis. The delineated regions of gains or losses will indicate locations of medulloblastoma-associated genes. A 0.887 Mbp homozygous deletion region was newly identified at 6q23.1. Frequent detection of reduced expression of AK091351 and KIAA1913 genes implicates them as suppressors of medulloblastoma tumorigenesis.
Expression and Growth Dependency of the Insulin-Like Growth Factor I Receptor in Craniopharyngioma Cells: A Novel Therapeutic Approach
Authors: Ulfarsson Elfar , Karström Alexandra , Yin Shucheng , Girnita Ada , Vasilcanu Daiana , Thoren Marja , Kratz Gunnar , Hillman Jan , Axelson Magnus , Larsson Olle , Girnita Leonard
Published: September 2005

Craniopharyngioma is a rare benign intracranial epithelial tumor that, however, often recurs and sometimes kills the affected patients, one-third of which are children. In many cases, the patients acquire growth hormone deficiency and postoperatively need substitution. Generally, growth hormone promotes local release of insulin-like growth factor I (IGF-I), which in turn activates the IGF-I receptor (IGF-IR) if present. Together, these circumstances raise the question whether IGF-IR may be involved in craniopharyngioma growth. To address this issue, we analyzed phenotypically well-characterized primary low-passage craniopharyngioma cell lines from nine different patients for IGF-IR expression and IGF-I dependency. Two of the cell lines showed no/very low expression of the receptor and was independent on IGF-I, whereas five cell lines exhibited a strong expression and was clearly contingent on IGF-I. The two remaining cell lines had low receptor expression and IGF-I dependency. Upon treatment with an IGF-IR inhibitor, cells with high IGF-IR expression responded promptly with decreased Akt phosphorylation followed by growth arrest. These responses were not seen in cells with no/very low receptor expression. Growth of cell lines with low IGF-IR expression was only slightly affected by IGF-IR inhibition. Taken together, our data suggest that IGF-IR may be involved in the growth of a subset of craniopharyngiomas and points to the possibility of the involvement of IGF-IR inhibitors as a treatment modality to obtain complete tumor-free conditions before growth hormone substitution.
Assessment of the Transcriptional Activity of p53 Improves the Prediction of Recurrence in Superficial Transitional Cell Carcinoma of the Bladder
Authors: Dekairelle Anne-France , Tombal Bertrand , Cosyns Jean-Pierre , Gala Jean-Luc
Published: September 2005

Purpose: To investigate the value of p53 functional analysis of separated alleles in yeast (FASAY) as a witness of p53/p21 pathway alteration and as a predictor of recurrence in superficial transitional cell carcinomas.

Experimental Design: p53 transcriptional activity was prospectively analyzed in 52 newly diagnosed transitional cell carcinoma using FASAY competent for the transactivation of p21 and bax promoters. TP53 and p21 gene expression was quantified by real-time PCR, and expression of corresponding proteins was assessed by immunohistochemistry. In addition to tumor stage and grade, the predictive value of FASAY, real-time PCR, and immunohistochemistry for tumor recurrence was assessed by Cox survival analysis.

Results: A total (p21 and bax) or partial (bax only) loss of transcriptional activity was observed in 15 of 52 (29%) and 4 of 52 (7.7%) cases, respectively, a partial loss being consistently associated with R283H mutation. p53 nuclear overexpression grossly overestimated (∼40%) or underestimated (∼10%) the true incidence of p53 transcriptional abnormalities, especially in Ta-T1 grade 1 to 2 tumors. Loss of p21 transactivation significantly correlated with decreased p21 gene expression and lack of expression of p21 (P = 0.001). FASAY had a better predictive value for recurrence than p53 immunohistochemistry (Cox hazard ratio, 6.57 versus 3.95; P = 0.0002 versus 0.019, respectively), whereas neither p21 immunohistochemistry (hazard ratio, 1.9; P = 0.29) nor TP53 or p21 gene expression were significant predictors of recurrence. The prognostic difference between FASAY and p53 immunohistochemistry was maintained in the subgroup of Ta-T1 grade 3 tumors.

Conclusions: FASAY is a valuable surrogate marker for assessing p53/p21 pathway alteration and predicts transitional cell carcinoma recurrence better than p53 immunohistochemistry.
Hematogenous Micrometastases in Osteosarcoma Patients
Authors: Bruland Øyvind S. , Høifødt Hanne , Sæter Gunnar , Smeland Sigbjørn , Fodstad Øystein
Published: September 2005

Bone marrow and peripheral blood samples from 60 patients with suspected bone sarcoma were examined for the presence and number of micrometastatic osteosarcoma cells by a sensitive immunomagnetic detection assay, using in parallel two osteosarcoma-associated antibodies. Forty-nine of the patients had osteosarcoma, and of these, as many as 31 (63%) had tumor cells in bone marrow, in many cases with a high number of cells. Only four (8%) were positive also in blood. None of 38 control bone marrow samples were positive, including 11 from patients with suspected bone sarcoma at time of sampling who later were found not to have osteosarcoma. Fifteen of 28 patients without overt metastases at primary diagnosis (54%) were positive, 12 of whom had localized high-grade primary tumors in the extremity. Four of these have relapsed compared with none of 10 negative patients. In the group of 22 patients with extremity localized nonmetastatic osteosarcoma, information was available on the histologic response to preoperative chemotherapy in 15 patients. None of the three patients in the bone marrow–negative group who had a poor response to chemotherapy have relapsed, whereas two of the four poor responders in the bone marrow–positive cohort are dead of disease. Among 12 patients with overt metastasis at primary diagnosis, 11 (92%) were positive in bone marrow with a very high number of osteosarcoma cells. The immunomagnetically isolated cells were further characterized by the use of fluorescent latex microparticles with surface-bound antibodies targeting different membrane markers. Moreover, in cases with numerous osteosarcoma cells in bone marrow attempts to grow the selected cells in vitro were successful in two of eight attempts, and in two of five cases, isolated cells produced tumors with osteosarcoma characteristics in nude mice. In conclusion, already at primary diagnosis, a very high fraction of osteosarcoma patients had malignant cells in bone marrow, and a correlation between the presence of tumor cells, clinical stage, and disease progression was found. The data show the clinical potential of this immunomagnetic method. Attempts to subgroup osteosarcoma patients for more individualized treatment based on the presence of micrometastatic cells should be studied in a larger cohort of patients.