bluuebunny/crossref_metadata_2025 huggingface dataset:
Methylation of
p16
CpG Islands Associated with Malignant Transformation of Gastric Dysplasia in a Population-Based Study
Authors: Sun Yu , Deng Dajun , You Wei-Cheng , Bai Hua , Zhang Lian , Zhou Jing , Shen Lin , Ma Jun-Ling , Xie Yu-Quan , Li Ji-You
Published: September 2005

Purpose: Inactivation of p16 by aberrant methylation of CpG islands is a frequent event in carcinomas and precancerous lesions of various organs, including the stomach. The aim of this study is to investigate the relationship between p16 methylation and malignant transformation of human gastric dysplasia (DYS) based on follow-up endoscopic screening in a high-risk population.

Experimental Design: Genomic DNA samples were extracted from paraffin blocks of gastric mucosal biopsies that were histopathologically diagnosed as low-grade DYS from patients who developed gastric carcinomas [GCs (n = 21)] and those that did not do so (n = 21) during 5 years of follow-up. The methylation status of p16 CpG islands of each sample was detected by methylation-specific PCR, denatured high-performance liquid chromatography, and sequencing.

Results: Aberrant p16 methylation was observed in 5 of 21 samples of DYS that progressed to GC but in 0 of 21 samples that did not progress to GC (P = 0.048, two-sided). Sequencing results confirmed that all CpG sites were methylated in the analyzed sequence from these five p16-methylated cases. Furthermore, p16 methylation was also observed in the five subsequent GCs. Unmethylated p16 CpG islands were detected in all of the samples without p16 methylation.

Conclusions: Our findings suggest p16 methylation is correlated with the malignant transformation of gastric DYS, and p16 methylation might be a useful biomarker for prediction of malignant potential of gastric DYS.
Genetically Altered Fields as Origin of Locally Recurrent Head and Neck Cancer
Authors: Tabor Maarten P. , Brakenhoff Ruud H. , Ruijter-Schippers Henrique J. , Kummer J. Alain , Leemans C. René , Braakhuis Boudewijn J. M.
Published: September 2005

Purpose: Surgeons treating patients with head and neck squamous cell carcinoma (HNSCC) rely heavily on histology to decide whether the resection margins are tumor free and subsequent adjuvant treatments can be omitted. However, despite the presence of tumor-free margins, 10–30% of HNSCC patients still develop a locally recurrent tumor. Evidence is available that recurrent cancer develops from either (a) outgrowth of a relatively small number of tumor cells that have not been detected by the pathologist or (b) a precursor lesion in which additional genetic alterations have led again to invasive cancer.

Experimental Design: In a retrospective study on 13 HNSCC cases, we analyzed the primary tumor, its surrounding histologically tumor-free resection margins, and local recurrences for loss of heterozygosity (22 microsatellite markers on 6 chromosomes) and TP53 mutations to determine the origin of the recurrent cancer.

Results: A precursor lesion was absent in 5 of 13 (39%) cases, and the genetic similarity of the primary and recurrent cancer was high, providing evidence that residual cancer cells were the origin of recurrence. For the remaining eight cases (61%) a genetically related precursor lesion (field) was detected, and for five of these cases, evidence was found that both the primary and recurrent carcinoma originated from this field. The remaining three cases were less conclusive.

Conclusions: This study explains the pathobiology of locally recurrent HNSCC in patients with histologically tumor-free resection margins and indicates that the development of novel therapies to decrease the local recurrence rates in HNSCC should not only be focused on eradicating residual cancer cells but also on the precursor lesions that are left behind.
Ability to Predict Metastasis Based On Pathology Findings and Alterations in Nuclear Structure Of Normal-Appearing and Cancer Peripheral Zone Epithelium in the Prostate
Authors: Veltri Robert W. , Khan Masood A. , Miller M. Craig , Epstein Jonathan I. , Mangold Leslie A. , Walsh Patrick C. , Partin Alan W.
Published: September 2005

Purpose: Malignant transformation in the prostate produces significant alterations in glandular architecture (Gleason grade) and nuclear structure that provide valuable prognostic information. Normal-appearing nuclei (NN) adjacent to cancer may also have altered functions in response to malignancy. We studied NN adjacent to peripheral zone (PZ) prostate cancer (PCa), as well as the PZ cancer nuclei (CaN) using quantitative image cytometry. The nuclear structure information was combined with routine pathological findings to predict metastatic PCa progression and/or death.

Experimental Design: Tissue microarrays of normal-appearing and cancer areas were prepared from 182 pathologist-selected paraffin blocks. Feulgen-stained CaN and NN were captured from the tissue microarrays using the AutoCyte Pathology Workstation. Multivariate logistic regression was used to calculate quantitative nuclear grade (QNG) solutions based on nuclear morphometric descriptors determined from NN and CaN. Multivariate logistic regression and Kaplan-Meier plots were also used to predict risk for distant metastasis and/or PCa-specific death using QNG solutions and routine pathology.

Results: The pathology model yielded an area under the receiver operator characteristic curve of 72.5%. The QNG-NN and QNG-CaN solutions yielded an area under the receiver operator characteristic curve of 81.6 and 79.9%, respectively, but used different sets of nuclear morphometric descriptors. Kaplan-Meier plots for the pathology variables, the QNG-NN and QNG-CaN solutions, were combined with pathology to defined three statistically significantly distinct risk groups for distant metastasis and/or death (P < 0.0001).

Conclusions: Alterations in cancer or normal-appearing nuclei adjacent to peripheral zone cancer areas can predict PCa progression and/or death. The QNG-NN and QNG-CA solutions could be combined with pathology variables to improve the prediction of distant metastasis.
Identification of C-Met Oncogene as a Broadly Expressed Tumor-Associated Antigen Recognized by Cytotoxic T-Lymphocytes
Authors: Schag Kerstin , Schmidt Susanne M. , Müller Martin R. , Weinschenk Toni , Appel Silke , Weck Markus M. , Grünebach Frank , Stevanovic Stefan , Rammensee Hans-Georg , Brossart Peter
Published: September 2005

Purpose: C-Met proto-oncogene is a receptor tyrosine kinase that mediates the oncogenic activities of the hepatocyte growth factor. Using a DNA chip analysis of tumor samples from patients with renal cell carcinoma and sequencing of peptides bound to the HLA-A*0201 molecules on tumor cells a peptide derived from the c-Met protein was identified recently.

Experimental Design: We used this novel HLA-A*0201 peptide for the induction of specific CTLs to analyze the presentation of this epitope by malignant cells.

Results: The induced CTL efficiently lysed target cells pulsed with the cognate peptide, as well as HLA-A*0201-matched tumor cell lines in an antigen-specific and HLA-restricted manner. Furthermore, the induced c-Met-specific CTLs recognized autologous dendritic cells (DCs) pulsed with the peptide or transfected with whole-tumor mRNA purified from c-Met-expressing cell lines. We next induced c-Met-specific CTLs using peripheral blood mononuclear cells and DC from an HLA-A*0201-positive patient with plasma cell leukemia to determine the recognition of primary autologous malignant cells. These CTLs lysed malignant plasma cells while sparing nonmalignant B- and T-lymphocytes, monocytes, and DCs.

Conclusion: Our results demonstrate that c-Met oncogene is a novel tumor rejection antigen recognized by CTL and expressed on a broad variety of epithelial and hematopoietic malignant cells.
Selective Tyrosine Hyperphosphorylation of Cytoskeletal and Stress Proteins in Primary Human Breast Cancers
Authors: Lim Yoon-Pin , Wong Chow Yin , Ooi London Lucien , Druker Brian J. , Epstein Richard J.
Published: September 2005

Purpose: Small-molecule growth factor receptor inhibitors block cell growth in vitro and downstream signaling in vivo, but controlled trials in patients with advanced solid tumors have yielded disappointing response rates. To clarify this discrepancy, we compared the patterns of tyrosine phosphoprotein expression in human cancer cells and primary tumors.

Experimental Design: Immunoaffinity chromatography, two-dimensional electrophoresis, and antiphosphotyrosine immunoblotting were combined with mass spectrometry to determine the phosphoproteomic signatures of 40 matched normal and malignant tissues from patients with breast or liver cancer. The identities and abundance of the detected tyrosine phosphoproteins were compared with those of ligand-responsive A431 cells.

Results: Patterns of tyrosine-phosphorylated proteins are similar among normal tissues of the same origin but vary markedly between different tissues. Primary breast tumors exhibit a strikingly homogeneous tyrosine phosphorylation profile, whereas liver cancers display greater phosphoproteomic diversity. The main breast-tumor-specific tyrosine phosphoproteins are cytoskeletal molecules (actin, tubulin, and vimentin) and molecular chaperones (Hsp70, Hsc71, and Grp75). In contrast, control studies in ligand-stimulated A431 human cancer cells revealed an additional phosphorylated subset of promitogenic phosphoproteins (Grb2, Shc, Jnk2, phospholipase C-γ, and phosphatidylinositol 3′-kinase).

Conclusions: Identification of cytoskeletal and stress proteins as the most abundant tyrosine phosphoproteins in breast tumors implicates these molecules, rather than promitogenic effectors, as the prime stoichiometric substrates for kinase-inhibitory anticancer drugs in vivo. Because phosphorylated cytoskeletal proteins and chaperones mediate cell motility and apoptotic resistance, respectively, these data raise the intriguing possibility that small-molecule tyrosine kinase inhibitors may be of greatest value either as adjuvant antimetastatic/-invasive drugs or as chemo-/radiosensitizers.
HER-2 Gene Amplification Correlates with Higher Levels of Angiogenesis and Lower Levels of Hypoxia in Primary Breast Tumors
Authors: Blackwell Kimberly L. , Dewhirst Mark W. , Liotcheva Vlayka , Snyder Stacey , Broadwater Gloria , Bentley Rex , Lal Anita , Riggins Gregory , Anderson Steve , Vredenburgh Jim , Proia Alan , Harris Lyndsay N.
Published: September 2005

Purpose: This study investigated the connection among HER-2 gene amplification, HER-2 protein expression, and markers of tumor angiogenesis and oxygenation in patients with operable, invasive breast tumors.

Experimental Design: From 1988 to 1995, 425 patients with metastatic breast cancer were enrolled in a study of high-dose chemotherapy with autologous transplant. Primary tumor blocks were obtained and evaluated using immunohistochemistry (IHC) staining of vessels with von Willebrand factor antibody. Mean microvessel densities (MVD) were determined by counting von Willebrand factor stained cells in three separate “vascular hot spots” using image analysis. Tumor samples were also stained for HER-2 by IHC, HER-2 gene amplification by fluorescence in situ hybridization, carbonic anhydrase 9 by IHC, and vascular endothelial growth factor (VEGF) by IHC. Plasma from 36 patients with primary tumor samples had VEGF (R&D Systems, MN) and d-dimer (American Diagnostica, Greenwich, CT) levels determined.

Results: There was a significant positive correlation between HER-2 gene amplification and both maximum and average MVD (Spearman coefficient = 0.51 and 0.50; P = 0.03 and 0.05, respectively). There was an inverse correlation with HER-2 gene amplification and expression of the tumor hypoxia marker CA-9 (χ2 P = 0.02). The level of HER-2 gene amplification correlated with plasma d-dimer levels (Spearman coefficient = 0.43; P = 0.021). Interestingly, tumors with HER-2 by IHC had decreased amounts of VEGF staining (χ2 = 5.81; P = 0.01). There was no correlation between HER-2 by IHC and MVD or d-dimer. Of all of the variables examined, only average (P = 0.0016) and maximum MVD (P = 0.0128) predicted disease-free survival (Cox univariate model).

Conclusions: HER-2-amplified breast cancers have increased amounts of angiogenesis, decreased amounts of hypoxia, and increased markers of fibrin degradation. These findings have prognostic, predictive, and therapeutic implications in breast cancer treatment.
Antitumor Effects of Thalidomide Analogs in Human Prostate Cancer Xenografts Implanted in Immunodeficient Mice
Authors: Ng Sylvia S. W. , MacPherson Gordon R. , Gütschow Michael , Eger Kurt , Figg William D.
Published: September 2005

Purpose: Thalidomide has demonstrated clinical activity in various malignancies including androgen-independent prostate cancer. The development of novel thalidomide analogs with better activity/toxicity profiles is an ongoing research effort. Our laboratory previously reported the in vitro antiangiogenic activity of the N-substituted thalidomide analog CPS11 and the tetrafluorinated analogs CPS45 and CPS49. The current study evaluated the therapeutic potential of these analogs in the treatment of prostate cancer in vivo.

Experimental Design: Severely combined immunodeficient mice bearing s.c. human prostate cancer (PC3 or 22Rv1) xenografts were treated with the analogs at their maximum tolerated doses. Tumors were then excised and processed for ELISA and CD31 immunostaining to determine the levels of various angiogenic factors and microvessel density (MVD), respectively.

Results: CPS11, CPS45, and CPS49 induced prominent and modest growth inhibition in PC3 and 22Rv1 tumors, respectively. Thalidomide had no effect on tumor growth in either xenograft. Vascular endothelial growth factor and basic fibroblast growth factor levels were not significantly altered by any of the thalidomide analogs or thalidomide in both PC3 and 22Rv1 tumors. CPS45, CPS49, and thalidomide significantly reduced PC3 tumor platelet-derived growth factor (PDGF)-AA levels by 58–82% (P < 0.05). Interestingly, treatment with the analogs and thalidomide resulted in differential down-regulation (≥1.5-fold) of genes encoding PDGF and PDGF receptor isoforms as determined by DNA microarray analysis. Intratumoral MVD of 22Rv1 xenografts was significantly decreased by CPS45 and CPS49. CPS49 also reduced MVD in PC3 xenografts.

Conclusions: Thalidomide analogs CPS11 and 49 are promising anti-cancer agents. PDGF signaling pathway may be a potential target for these thalidomide analogs. Detailed microarray and functional analyses are under way with the aim of elucidating the molecular mechanism(s) of action of these thalidomide analogs.
CpG Island Methylation Is Responsible for
p14ARF
Inactivation and Inversely Correlates with p53 Overexpression in Resected Non–Small Cell Lung Cancer
Authors: Hsu Han-Shui , Wang Yu-Chien , Tseng Ruo-Chia , Chang Jer-Wei , Chen Jung-Ta , Shih Chuen-Ming , Chen Chih-Yi , Wang Yi-Ching
Published: September 2005

Purpose and Experimental Design: The molecular mechanisms by which the p14ARF gene is altered in non–small cell lung cancer (NSCLC) are complex and unclear. Using genetic and epigenetic analyses, we examined various molecular alterations including the loss of protein and mRNA expression, and 5′CpG hypermethylation, allelic imbalance, and mutation of the p14ARF gene in a series of 102 NSCLC samples, in parallel with clinicopathological and prognostic analyses. To clarify the biological significance of p14ARF alterations, its relationship with p16INK4a and p53 alterations was also examined.

Results: We found that 34% of NSCLC patients had aberrant P14ARF protein expression, which was more frequent in adenocarcinomas (AD; 44%) than in squamous cell carcinomas (22%; P = 0.024). A high concordance was observed between alterations in protein and mRNA expression and 5′CpG hypermethylation (P ≤ 0.001). The p14ARF hypermethylation inversely correlated with P53 overexpression (P = 0.001). This mutually exclusive relationship for alteration between p14ARF and p53 was also supported by a worse prognosis of AD patients with positive P14ARF expression (P = 0.01) and of AD patients with P53 overexpression (P = 0.006). Our data also indicated that hemizygous/homozygous deletion and mutation in the p14ARF gene occurred at 26%, 9%, and 0%, respectively, of microdissected NSCLCs.

Conclusions: Our data suggest that p14ARF 5′CpG hypermethylation is the predominant mechanism involved in the aberrant expression of the p14ARF gene. In addition, p14ARF 5′CpG hypermethylation occurs inversely to P53 overexpression.
Molecular Profiles of Neurofibromatosis Type 1-Associated Plexiform Neurofibromas
Authors: Lévy Pascale , Bièche Ivan , Leroy Karen , Parfait Béatrice , Wechsler Janine , Laurendeau Ingrid , Wolkenstein Pierre , Vidaud Michel , Vidaud Dominique
Published: September 2005

Purpose: Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder with a complex variety of clinical symptoms. The hallmark of NF1 is the development of heterogeneous benign neurofibromas, which may appear as dermal neurofibromas or plexiform neurofibromas. NF1 patients with plexiform neurofibromas are at risk of developing malignant peripheral nerve sheath tumors.

Experimental Design: To obtain additional insight into the molecular pathogenesis of plexiform neurofibromas, we used real-time quantitative reverse transcription-PCR assays to quantify the mRNA expression of 349 selected genes in plexiform neurofibromas in comparison with dermal neurofibromas and patient-matched malignant peripheral nerve sheath tumors.

Results: Thirty genes were significantly up-regulated in plexiform neurofibromas compared with dermal neurofibromas. None were down-regulated. The up-regulated genes mainly encoded transcription factors and growth factors and secreted proteins, cytokines, and their receptors, pointing to a role of paracrine and autocrine signaling defects in the genesis of plexiform neurofibromas. We also identified a gene expression profile, based on MMP9, FLT4/VEGFR3, TNFRSF10B/TRAILR2, SHH, and GLI1, which discriminated those plexiform neurofibromas most likely to undergo malignant transformation.

Conclusion: Our study has identified a limited number of signaling pathways that could be involved, when altered, in plexiform neurofibroma development. Some of the up-regulated genes could be useful diagnostic or prognostic markers or form the basis of novel therapeutic strategies.
Molecular Cytogenetic Identification of Subgroups of Grade III Invasive Ductal Breast Carcinomas with Different Clinical Outcomes
Authors: Jones Chris , Ford Emily , Gillett Cheryl , Ryder Ken , Merrett Samantha , Reis-Filho Jorge S. , Fulford Laura G. , Hanby Andrew , Lakhani Sunil R.
Published: September 2005

Tumor grade is an established indicator of breast cancer outcome, although considerable heterogeneity exists even within-grade. Around 25% of grade III invasive ductal breast carcinomas are associated with a “basal” phenotype, and these tumors are reported to be a distinct subgroup. We have investigated whether this group of breast cancers has a distinguishing pattern of genetic alterations and which of these may relate to the different clinical outcome of these patients. We performed comparative genomic hybridization (CGH) analysis on 43 grade III invasive ductal breast carcinomas positive for basal cytokeratin 14, as well as 43 grade- and age-matched CK14-negative controls, all with up to 25 years (median, 7 years) of clinical follow-up. Significant differences in CGH alterations were seen between the two groups in terms of mean number of changes (CK14+ve − 6.5, CK14−ve − 10.3; P = 0.0012) and types of alterations at chromosomes 4q, 7q, 8q, 9p, 13q, 16p, 17p, 17q, 19p, 19q, 20p, 20q and Xp. Supervised and unsupervised algorithms separated the two groups on CGH data alone with 76% and 74% accuracy, respectively. Hierarchical clustering revealed distinct subgroups, one of which contained 18 (42%) of the CK14+ve tumors. This subgroup had significantly shorter overall survival (P = 0.0414) than other grade III tumors, regardless of CK14 status, and was an independent prognostic marker (P = 0.031). These data provide evidence that the “basal” phenotype on its own does not convey a poor prognosis. Basal tumors are also heterogeneous with only a subset, identifiable by pattern of genetic alterations, exhibiting a shorter overall survival. Robust characterization of this basal group is necessary if it is to have a major impact on management of patients with breast cancer.
Contribution of Androgen Deprivation Therapy to Elevated Osteoclast Activity in Men with Metastatic Prostate Cancer
Authors: Michaelson M. Dror , Marujo Rose M. , Smith Matthew R.
Published: September 2005

Purpose: Biochemical markers of both osteoblast and osteoclast activity are elevated in men with osteoblastic metastases from prostate cancer. Androgen deprivation therapy (ADT), the mainstay of therapy for advanced prostate cancer, increases markers of osteoblast and osteoclast activity, even in the absence of bone metastases. Little is known about the relative contributions of ADT and skeletal metastases to elevated bone turnover in men with prostate cancer.

Experimental Design: To evaluate the relative contributions of ADT and skeletal metastases to osteoblast and osteoclast activity, we performed a cross-sectional study in three groups of men with advanced prostate cancer: (a) hormone-naïve men without bone metastases; (b) castrate men without bone metastases; and (c) castrate men with bone metastases. The primary study end points were serum levels of bone-specific alkaline phosphatase (BSAP), a marker of osteoblast activity, and N-telopeptide (NTX), a marker of osteoclast activity.

Results: Serum levels of both BSAP and NTX were significantly higher in groups of castrate men (groups 2 and 3) than in hormone-naïve men (group 1; P < 0.01 for all comparisons). Among castrate men, serum BSAP was significantly higher in men with bone metastases than in men without bone metastases (P = 0.01). In contrast, serum levels of NTX were similar in groups 2 and 3 (P = 0.33).

Conclusions: The unintended effects of ADT on the skeleton are sufficient to explain increased osteoclast activity in castrate men with bone metastases. These results may have important implications for the optimal timing and schedule of osteoclast-targeted therapy in men with advanced prostate cancer.
Enhanced Expression of Leptin and Leptin Receptor (OB-R) in Human Breast Cancer
Authors: Ishikawa Makoto , Kitayama Joji , Nagawa Hirokazu
Published: September 2005

Purpose: To evaluate leptin and leptin receptor (OB-R) expression in human breast cancer and determine whether it could be effective for the prevention and treatment of breast cancer.

Experimental Design: Immunohistochemical staining using specific antibodies was used to evaluate the protein expression of leptin and OB-R in 76 invasive ductal carcinomas and 32 samples of corresponding normal mammary gland, and the relationship between the expression of OB-R and leptin and clinicopathological features was analyzed.

Results: Normal mammary epithelial cells did not express a significant level of Ob-R, whereas carcinoma cells showed positive staining for OB-R in 63 (83%) cases. Both normal epithelial cells and carcinoma cells expressed a significant level of leptin. However, overexpression of leptin, as determined by staining intensity, was observed in 70 cancers (92%) but in no normal epithelium. The expression of OB-R showed a significant correlation with the level of leptin expression. Interestingly, distant metastasis was detected in 21 (34%) of 61 OB-R-positive tumors with leptin overexpression, but in none of the 15 tumors that lacked OB-R expression or leptin overexpression (P < 0.05). Consequently, patients with the former tumors showed significantly lower survival than those with the latter.

Conclusions: Leptin may have a promoting effect on the carcinogenesis and metastasis of breast cancer, possibly in an autocrine manner. Functional inhibition of leptin may be effective for the prevention and treatment of breast cancer.
Cyclin D1, p53, and p21Waf1/Cip1 Expression Is Predictive of Poor Clinical Outcome in Serous Epithelial Ovarian Cancer
Authors: Bali Anish , O’Brien Philippa M. , Edwards Lyndal S. , Sutherland Robert L. , Hacker Neville F. , Henshall Susan M.
Published: September 2005

Purpose: Dysregulation of cell cycle control, in particular G1-S-phase transition, is implicated in the pathogenesis of most human cancers, including epithelial ovarian cancer (EOC). However, the prognostic significance of aberrant cell cycle gene expression in EOC remains unclear.

Experimental Design: The expression of selected genes from the pRb pathway that regulates G1-S-phase progression, including cyclin D1, p16Ink4a, cyclin E, p27Kip1, p21Waf1/Cip1, and p53, was examined in a consecutive series of 134 serous EOC using immunohistochemistry and the results correlated to disease outcome.

Results: Molecular markers predictive of reduced overall survival in univariate analysis were overexpression of cyclin D1 (P = 0.03) and p53 (P = 0.03) and reduced expression of p27Kip1 (P = 0.05) and p21Waf1/Cip1 (P = 0.02), with the latter three also being prognostic for a shorter progression-free interval. In addition, patients displaying overexpression of p53 with concurrent loss of p21Waf1/Cip1 had a significantly shorter overall (P = 0.0008) and progression-free survival (P = 0.0001). On multivariate analysis, overexpression of cyclin D1 and combined loss of p21Waf1/Cip1 in the presence of p53 overexpression were independent predictors of overall survival. Similarly, the combination of p21Waf1/Cip1 loss and p53 overexpression was independently predictive of a shorter progression-free interval. Overexpression of p53 and cyclin E and reduced expression of p27Kip1 and p21Waf1/Cip1 were significantly associated with increasing tumor grade.

Conclusions: This study confirms that dysregulation of cell cycle genes is common in EOC, and that aberrant expression of critical cell cycle regulatory proteins can predict patient outcome in serous EOC.
Reduced Lecithin
Authors: Boorjian Stephen , Tickoo Satish K. , Mongan Nigel P. , Yu Huayin , Bok Dean , Rando Robert R. , Nanus David M. , Scherr Douglas S. , Gudas Lorraine J.
Published: September 2005

Purpose: Retinoids, which include vitamin A (retinol; ROL) and its derivatives, have been investigated in the treatment of bladder cancer. We have shown that expression of the enzyme lecithin:ROL acyltransferase (LRAT), which converts ROL to retinyl esters, is reduced in several human cancers. Here we evaluated expression of LRAT protein and mRNA in normal and malignant bladder tissue specimens from human patients. We also examined the effect of retinoids on LRAT expression in bladder cancer cell lines.

Experimental Design: We evaluated 49 bladder cancer specimens for LRAT protein expression using immunohistochemistry with affinity-purified antibodies to human LRAT. LRAT mRNA expression was assessed using reverse transcription-PCR in bladder specimens from an additional 16 patients. We examined the effect of retinoic acid and ROL on LRAT mRNA expression in five human bladder cancer cell lines.

Results: LRAT protein was detected throughout the nonneoplastic bladder epithelium in all of the specimens. In bladder tumors, LRAT protein expression was reduced compared with the nonneoplastic epithelium or was completely absent in 7 of 32 (21.9%) superficial tumors versus 16 of 17 (94.1%) invasive tumors (P < 0.001). All of the non-neoplastic bladder specimens tested (11 of 11) showed LRAT mRNA expression, compared with 5 of 8 (62%) superficial tumors and 0 of 5 (0%) invasive tumors (P = 0.001). Three of five human bladder cancer cell lines expressed LRAT mRNA independent of retinoid exposure, whereas in two cell lines LRAT mRNA expression was induced by retinoid treatment.

Conclusions: We report a significant reduction in LRAT expression in bladder cancer. Moreover, we demonstrate an inverse correlation of LRAT mRNA and protein expression with increasing tumor stage. These data suggest that loss of LRAT expression is associated with invasive bladder cancer.
Global Gene Expression Profile of Nasopharyngeal Carcinoma by Laser Capture Microdissection and Complementary DNA Microarrays
Authors: Sriuranpong Virote , Mutirangura Apiwat , Gillespie John W. , Patel Vyomesh , Amornphimoltham Panomwat , Molinolo Alfredo A. , Kerekhanjanarong Veerachai , Supanakorn Siripornchai , Supiyaphun Pakpoom , Rangdaeng Samreung , Voravud Narin , Gutkind J. Silvio
Published: September 2005

A number of genetic and epigenetic changes underlying the development of nasopharyngeal carcinomas have recently been identified. However, there is still limited information on the nature of the genes and gene products whose aberrant expression and activity promote the malignant conversion of nasopharyngeal epithelium. Here, we have performed a genome-wide transcriptome analysis by probing cDNA microarrays with fluorescent-labeled amplified RNA derived from laser capture microdissected cells procured from normal nasopharyngeal epithelium and areas of metaplasia-dysplasia and carcinoma from EBV-associated nasopharyngeal carcinomas. This approach enabled the identification of genes differentially expressed in each cell population, as well as numerous genes whose expression can help explain the aggressive clinical nature of this tumor type. For example, genes indicating cell cycle aberrations (cyclin D2, cyclin B1, activator of S-phase kinase, and the cell cycle checkpoint kinase, CHK1) and invasive-metastatic potential (matrix metalloproteinase 11, v-Ral, and integrin β4) were highly expressed in tumor cells. In contrast, genes underexpressed in tumors included genes involved in apoptosis (B-cell CLL/lymphoma 6, secretory leukocyte protease inhibitor, and calpastatin), cell structure (keratin 7 and carcinoembryonic antigen-related cell adhesion molecule 6), and putative tumor suppressor genes (H-Ras-like suppressor 3, retinoic acid receptor responder 1, and growth arrested specific 8) among others. Gene expression patterns also suggested alterations in the Wnt/β-catenin and transforming growth factor β pathways in nasopharyngeal carcinoma. Thus, expression profiles indicate that aberrant expression of growth, survival, and invasion-promoting genes may contribute to the molecular pathogenesis of nasopharyngeal carcinoma. Ultimately, this approach may facilitate the identification of clinical useful markers of disease progression and novel potential therapeutic targets for nasopharyngeal carcinoma.
Serum Levels of Insulin Growth Factor (IGF-I) and IGF-Binding Protein Predict Risk of Second Primary Tumors in Patients with Head and Neck Cancer
Authors: Wu Xifeng , Zhao Hua , Do Kim-Anh , Johnson Marcella M. , Dong Qiong , Hong Waun Ki , Spitz Margaret R.
Published: September 2005

Purpose: Second primary tumors (SPTs) are a hallmark of head and neck squamous cell carcinomas (HNSCCs). Serum levels of insulin growth factors (IGFs) and their binding proteins (IGFBPs) have been associated with subsequent development of several epithelial cancers in prospective studies.

Experimental Design: To examine the role of IGFs in SPT development, we conducted a nested case–control study within a randomized, placebo-controlled chemoprevention trial in patients with early-stage HNSCC. We compared prediagnostic serum IGF-I and IGFBP-3 levels in 80 patients who subsequently developed SPTs and 173 controls (patients without SPTs) matched to the cases on age (±5 years), sex, ethnicity, year of randomization, and length of follow-up.

Results: The cases exhibited significantly higher levels of IGF-I and IGFBP-3 than did the controls (P = 0.001 and 0.019, respectively). Elevated IGF-I levels were associated with a 3.66-fold significantly increased risk of SPT. Lower and higher IGFBP-3 levels were associated with a 2.22- and 7.12-fold significant increased risk, respectively. The median SPT-free time was significantly shorter in patients with higher IGF-I levels than in patients with lower IGF-I levels (P < 0.0001). A similar trend was observed for IGFBP-3 (P = 0.002). Moreover, in the Cox proportional hazards model, higher IGF-I levels were significantly associated with increased risk of SPT with a hazard ratio of 2.78. Patients with the lower and higher IGFBP-3 levels also exhibited significantly increased risks with hazard ratios of 1.65 and 2.17, respectively.

Conclusions: This is the first study demonstrating that higher IGF-I levels, and lower and higher IGFBP-3 levels are risk factors for SPT development. Thus, measuring serum IGF-I and IGFBP-3 levels may be useful markers in assessing the risk of second tumors in patients successfully treated for their index cancer.
Mitogen-Activated Protein Kinase Phosphatase-1 Is Overexpressed in Non-Small Cell Lung Cancer and Is an Independent Predictor of Outcome in Patients
Authors: Vicent Silvestre , Garayoa Mercedes , López-Picazo José M. , Lozano María D. , Toledo Gemma , Thunnissen Frederik B. J. M. , Manzano Ramón G. , Montuenga Luis M.
Published: September 2005

Purpose: An increase in the activity of the mitogen-activated protein kinases (MAPKs) has been correlated with a more malignant phenotype in several tumor models in vitro and in vivo. A key regulatory mechanism of the MAPKs [extracellular signal-regulated kinase (ERK); c-jun NH2-terminal kinase (JNK); and p38] is the dual specificity phosphatase CL100, also called MAPK phosphatase-1 (MKP-1). This study was designed to examine the involvement of CL100/MKP-1 and stress-related MAPKs in lung cancer.

Experimental Design: We assessed the expression of CL100/MKP-1 and the activation of the MAPKs in a panel of 18 human cell lines [1 primary normal bronchial epithelium, 8 non-small cell lung cancer (NSCLC), 7 small cell lung cancer (SCLC), and 2 carcinoids] and in 108 NSCLC surgical specimens.

Results: In the cell lines, CL100/MKP-1 expression was substantially higher in NSCLC than in SCLC. P-ERK, P-JNK, and P-p38 were activated in SCLC and NSCLC, but the degree of their activation was variable. Immunohistochemistry in NSCLC resection specimens showed high levels of CL100/MKP-1 and activation of the three MAPK compared with normal lung. In univariate analysis, no relationship was found among CL100/MKP-1 expression and P-ERK, P-JNK, or P-p38. Interestingly, high CL100/MKP-1 expression levels independently predicted improved survival in multivariate analysis. JNK activation associated with T1–2 and early stage, whereas ERK activation correlated with late stages and higher T and N. Neither JNK nor ERK activation were independent prognostic factors when studied for patient survival.

Conclusions: Our data indicate the relevance of MAPKs and CL100/MKP-1 in lung cancer and point at CL100/MKP-1 as a potential positive prognostic factor in NSCLC. Finally, our study supports the search of new molecular targets for lung cancer therapy within the MAPK signaling pathway.
Novel Histone Deacetylase Inhibitors in the Treatment of Thyroid Cancer
Authors: Mitsiades Constantine S. , Poulaki Vassiliki , McMullan Ciaran , Negri Joseph , Fanourakis Galinos , Goudopoulou Athina , Richon Victoria M. , Marks Paul A. , Mitsiades Nicholas
Published: September 2005

Histone deacetylases (HDAC) and histone acetyltransferases exert opposing enzymatic activities that modulate the degree of acetylation of histones and other intracellular molecular targets, thereby regulating gene expression, cellular differentiation, and survival. HDAC inhibition results in accumulation of acetylated histones and induces differentiation and/or apoptosis in transformed cells. In this study, we characterized the effect of two HDAC inhibitors, suberoylanilide hydroxamic acid (SAHA) and m-carboxycinnamic acid bis-hydroxamide, on thyroid carcinoma cell lines, including lines originating from anaplastic and medullary carcinomas. In these models, both SAHA and m-carboxycinnamic acid bis-hydroxamide induced growth arrest and caspase-mediated apoptosis and increased p21 protein levels, retinoblastoma hypophosphorylation, BH3-interacting domain death agonist cleavage, Bax up-regulation, down-regulation of Bcl-2, A1, and Bcl-xL expression, and cleavage of poly(ADP-ribose) polymerase and caspase-8, -9, -3, -7, and -2. Transfection of Bcl-2 cDNA partially suppressed SAHA-induced cell death. SAHA down-regulated the expression of the apoptosis inhibitors FLIP and cIAP-2 and sensitized tumor cells to cytotoxic chemotherapy and death receptor activation. Our studies provide insight into the tumor type–specific mechanisms of antitumor effects of HDAC inhibitors and a framework for future clinical applications of HDAC inhibitors in patients with thyroid cancer, including histologic subtypes (e.g., anaplastic and medullary thyroid carcinomas) for which limited, if any, therapeutic options are available.
Antiangiogenic Properties of 17-(Dimethylaminoethylamino)-17-Demethoxygeldanamycin
Authors: Kaur Gurmeet , Belotti Dorina , Burger Angelika M. , Fisher-Nielson Kirsten , Borsotti Patrizia , Riccardi Elena , Thillainathan Jagada , Hollingshead Melinda , Sausville Edward A. , Giavazzi Raffaella
Published: September 2005

Purpose: The purpose of this study was to investigate the antiangiogenic properties of 17-(dimethylaminoethylamino)-17-demethoxygeldanamycin (17-DMAG; NSC707545), a water-soluble benzoquinone ansamycin.

Experimental Design: The activity of 17-DMAG, in vivo, was evaluated for inhibition of fibroblast growth factor (FGF)-2-induced angiogenesis in s.c. implanted Matrigel in mice. In vitro, the activity of 17-DMAG on endothelial cells (human umbilical vein endothelial cells; HUVEC) was tested in FGF-2; and vascular endothelial growth factor (VEGF)-induced proliferation and apoptosis, motility, and extracellular matrix invasion; and on the alignment of capillary like structures in Matrigel. The protein level of heat shock protein (Hsp)90 and client proteins was examined by Western blot in FGF-2 and VEGF-stimulated HUVEC.

Results: Daily oral administration of 17-DMAG affected the angiogenic response in Matrigel in a dose-dependent manner. The hemoglobin content in the Matrigel implants was significantly inhibited, and the histological analysis confirmed a decrease of CD31+ endothelial cells and of structures organized in cord and erythrocyte-containing vessels. In vitro, the compound inhibited dose-dependently the migration and the extracellular matrix-invasiveness of HUVEC and their capacity to form capillary like structures in Matrigel. 17-DMAG treatment also inhibited FGF-2 and VEGF-induced HUVEC proliferation and resulted in apoptosis. Accordingly, the expression of Hsp90 direct client proteins (pAkt and c-Raf-1) or their downstream substrates including pERK was also affected. 17-DMAG consistently increased the expression of Hsp70. Throughout the study similar results were obtained with 17-allylamino-17-demethoxygeldanamycin (17-AAG; NSC330507), the analog compound currently undergoing clinical trials.

Conclusions: We show that the Hsp90 targeting agents 17-DMAG and 17-AAG inhibit angiogenesis. The strong effects on endothelial cell functions, in vitro, indicate that the antiangiogenic activity of 17-DMAG/17-AAG could also be due to a direct effect on endothelial cells. The oral bioavailability of 17-DMAG might be of advantage in investigating the potential of this compound in clinical trials with antiangiogenic as well as antiproliferative endpoints.
Genetic and Epigenetic Changes in
p21
and
p21B
Do Not Correlate with Resistance to Doxorubicin or Mitomycin and 5-Fluorouracil in Locally Advanced Breast Cancer
Authors: Staalesen Vidar , Leirvaag Beryl , Lillehaug Johan Richard , Lønning Per Eystein
Published: September 2005

Purpose: The cyclin-dependent kinase inhibitor p21 acts as a main executor of p53-induced growth arrest. Recently, a second transcript, p21B, was found to code for a protein expressing proapoptotic activity. We investigated p21 and p21B for mutations and epigenetic silencing in locally advanced breast cancers treated with doxorubicin or 5-fluorouracil/mitomycin and correlated our findings with treatment response and TP53 status.

Experimental Design: We used reverse transcription-PCR to analyze p21/p21B mutation status in 73 breast cancer samples. The p21 promoter region was sequenced and analyzed for hypermethylations by methylation-specific PCR. In addition, a selection of patients were analyzed for mutations in the p21B promoter.

Results: The p21 gene was neither mutated nor silenced by promoter hypermethylation in any of the tumors examined. One patient harbored a novel p21 splice variant in addition to the wild-type transcript. We observed two base substitutions in the p21 transcript, C93A and G251A, each affecting six patients (8.2%). The G251A variant had not been reported previously. In 12 patients (16.4%), we observed a novel base substitution, T35C, in p21B. All three base substitutions were observed in lymphocyte DNA and therefore considered polymorphisms. The polymorphisms did not correlate with p21 staining index, treatment response to doxorubicin or 5-fluorouracil/mitomycin, or TP53 status.

Conclusions: Our findings do not suggest that genetic or epigenetic disturbances in p21 or p21B cause resistance to doxorubicin or mitomycin/5-fluorouracil in breast cancer. Future studies should assess potential associations between these novel polymorphisms and breast cancer risk.
Enhanced Activity of Hu14.18-IL2 Immunocytokine against Murine NXS2 Neuroblastoma when Combined with Interleukin 2 Therapy
Authors: Neal Zane C. , Yang Jeannie C. , Rakhmilevich Alexander L. , Buhtoiarov Ilia N. , Lum Hillary E. , Imboden Michael , Hank Jacquelyn A. , Lode Holger N. , Reisfeld Ralph A. , Gillies Stephen D. , Sondel Paul M.
Published: September 2005

Established s.c. NXS2 murine neuroblastoma tumors exhibited transient resolution after suboptimal therapy using the hu14.18-IL2 immunocytokine (IC). The hu14.18-IL2 IC is a fusion protein that has linked a molecule of interleukin 2 (IL-2) to the COOH terminus of each of the IgG heavy chains on the humanized anti-GD2 monoclonal antibody hu14.18. To induce more potent and longer lasting in vivo antitumor effects, we tested hu14.18-IL2 IC in a regimen combining it with constant infusion IL-2 in NXS2 tumor-bearing mice. The addition of the constant infusion IL-2 augmented the antitumor response induced by treatment with the hu14.18-IL2 IC in animals with experimentally induced hepatic metastases and in animals bearing localized s.c. tumors. The combined treatment induced prolonged tumor eradication in most animals bearing s.c. tumors and involved both natural killer cells and T cells. The enhanced ability of this combined treatment to prevent tumor recurrence was not observed when a larger dose of hu14.18-IL2 IC, similar in IL-2 content to the IC plus systemic IL-2 regimen, was tested as single-agent therapy. Animals showing prolonged tumor eradication of established tumors after the combined hu14.18-IL2 plus IL-2 regimen exhibited a protective T-cell-dependent antitumor memory response against NXS2 rechallenge.
The Tumor-Associated Antigen
PRAME
Is Universally Expressed in High-Stage Neuroblastoma and Associated with Poor Outcome
Authors: Oberthuer André , Hero Barbara , Spitz Rüdiger , Berthold Frank , Fischer Matthias
Published: September 2005

Purpose: The tumor-associated antigen PRAME, a potential candidate for immunotherapeutic targeting, is frequently expressed in a variety of cancers. However, no information about its presence in neuroblastoma is available to date. We therefore evaluated and quantified PRAME expression in a considerable number of neuroblastoma tumors and assessed its impact on the outcome of patients.

Experimental Design: Qualitative analysis of PRAME expression was assessed by reverse transcription (RT)-PCR screening of 94 patients with primary neuroblastoma. The same cohort was used for semiquantitative determination of transcript levels by Northern blotting, comparing the signal intensities of patients with those of testis total RNA. For more precise quantification of PRAME expression, real-time RT-PCR was performed in 88 patients of the above cohort and 7 additional patients, thus leaving a total of 101 patients that were analyzed with either method. Furthermore, association with tumor stage, age of patients at diagnosis, and MYCN amplification was determined as well as the prognostic impact of PRAME expression.

Results: RT-PCR screening detected PRAME expression in 93% of primary neuroblastoma and 100% of patients with advanced disease. Furthermore, RT-PCR and Northern blot analysis showed a highly significant association of PRAME expression with both higher tumor stage (P < 0.01) and the age of patients at diagnosis (P < 0.01). Finally, precise quantification of PRAME expression by quantitative real-time reverse transcription-PCR displayed significant impact on the outcome of patients.

Conclusions: PRAME expression in neuroblastoma is extraordinarily common and was universally seen in patients with advanced-stage disease in our study. Furthermore, significant impact of PRAME expression on the outcome of patients was shown. Thus, PRAME may present a particularly attractive target for immunotherapeutic strategies in neuroblastoma.
Vascular Endothelial Growth Factor-Trap Suppresses Tumorigenicity of Multiple Pancreatic Cancer Cell Lines
Authors: Fukasawa Mitsuharu , Korc Murray
Published: September 2005

Purpose: Vascular endothelial growth factor A (VEGF-A) is a potent angiogenic agent that binds to two high affinity VEGF receptors (VEGFRs), a process facilitated by the low affinity neuropilin receptors. Although VEGF-A is overexpressed in pancreatic ductal adenocarcinoma, it is not known whether the in vivo growth of multiple pancreatic cancer cells can be efficiently blocked by VEGF-A sequestration.

Experimental Design: Four human pancreatic cancer cell lines were grown s.c. in athymic nude mice. One cell line also was used to generate an orthotopic model of metastatic pancreatic cancer. The consequences of VEGF-A sequestration on tumor growth and metastasis were examined by injecting the mice with a soluble VEGFR chimer (VEGF-Trap) that binds VEGF-A with high affinity.

Results: VEGF-Trap, initiated 2 days after tumor cell inoculation, suppressed the s.c. growth of four pancreatic cancer cell lines and markedly decreased tumor microvessel density. Analysis of RNA from tumors generated with T3M4 cells revealed that VEGF-Trap decreased the expression of VEGFR-1 and neuropilin-1 and -2. VEGF-Trap, initiated 3 weeks after tumor implantation, also attenuated intrapancreatic tumor growth and metastasis in an orthotopic model using PANC-1 cells.

Conclusions: VEGF-Trap is a potent suppressor of pancreatic tumor growth and metastasis and also may act to attenuate neuropilin-1 and -2 and VEGFR-1 expression. Therefore, VEGF-Trap may represent an exceedingly useful therapeutic modality for pancreatic ductal adenocarcinoma.