bluuebunny/crossref_metadata_2025 huggingface dataset:
Silibinin Efficacy against Human Hepatocellular Carcinoma
Authors: Varghese Leyon , Agarwal Chapla , Tyagi Alpana , Singh Rana P. , Agarwal Rajesh
Published: March 2006

Purpose: Hepatocellular carcinoma (HCC) is one of the most common recurrent malignancies, for which, currently, there is no effective therapy. Considering the antihepatotoxic activity of silibinin, a widely used drug and supplement for various liver disorders, together with its strong preventive and anticancer efficacy against various epithelial cancers, we investigated the efficacy of silibin against human HCC cells.

Experimental Design: Silibinin effects were examined on growth, cytotoxicity, apoptosis, and cell cycle progression in two different HCC cell lines, HepG2 (hepatitis B virus negative; p53 intact) and Hep3B (hepatitis B virus positive; p53 mutated). At molecular level, cell cycle effects of silibinin were assessed by immunoblotting and in-bead kinase assays.

Results: Silibinin strongly inhibited growth of both HepG2 and Hep3B cells with a relatively stronger cytotoxicity in Hep3B cells, which was associated with apoptosis induction. Silibinin also caused G1 arrest in HepG2 and both G1 and G2-M arrests in Hep3B cells. Mechanistic studies revealed that silibinin induces Kip1/p27 but decreases cyclin D1, cyclin D3, cyclin E, cyclin-dependent kinase (CDK)-2, and CDK4 levels in both cell lines. In Hep3B cells, silibinin also reduced the protein levels of G2-M regulators. Furthermore, silibinin strongly inhibited CDK2, CDK4, and CDC2 kinase activity in these HCC cells.

Conclusion: Together, these results for the first time identify the biological efficacy of silibinin against HCC cells, suggesting the importance of conducting further investigations in preclinical HCC models, especially on in vivo efficacy, to support the clinical usefulness of silibinin against hepatocellular carcinoma in addition to its known clinical efficacy as an antihepatotoxic agent.
Synergistic Antitumor Activity of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor Gefitinib and IFN-α in Head and Neck Cancer Cells In vitro and In vivo
Authors: Bruzzese Francesca , Di Gennaro Elena , Avallone Antonio , Pepe Stefano , Arra Claudio , Caraglia Michele , Tagliaferri Pierosandro , Budillon Alfredo
Published: March 2006

Purpose: Epidermal growth factor receptor (EGFR) overexpression has been implicated in the development of head and neck squamous cell carcinomas (HNSCC) and represents a potential therapeutic target for this disease. We have reported previously that growth inhibitory concentrations of IFN-α enhance the expression and activity of EGFR and that this effect could represent an escape mechanism to the growth inhibition and apoptotic cell death induced by IFN-α. In this study, we investigate whether the combination of IFN-α and gefitinib (Iressa, AstraZeneca Pharmaceuticals, Macclesfield, United Kingdom), a selective EGFR tyrosine kinase inhibitor, might have a cooperative antitumor effect on HNSCC-derived cell lines.

Experimental Design: The interaction of IFN-α and gefitinib was evaluated in vitro on HNSCC-derived cell lines by median drug effect analysis calculating a combination index with CalcuSyn software and in vivo by using HNSCC xenografts in nude mice. The mechanism of gefitinib and IFN-α interactions was also studied by analysis of cell cycle kinetics, apoptosis assays, and Western blotting of EGFR signal transduction components.

Results: Simultaneous exposure to gefitinib and IFN-α produced synergistic antiproliferative and proapoptotic effects compared with single drug treatment. Furthermore, daily treatment of gefitinib (50 mg/kg p.o.) in combination with an IFN-α regimen (50,000 units s.c. three times weekly) induced tumor growth delay and increased survival rate on established HNSCC xenografts in nude mice. Moreover, the concomitant treatment with gefitinib suppressed the stimulation of extracellular signal-regulated kinase phosphorylation/activity induced by IFN-α both in vitro and in vivo.

Conclusion: The observed cooperative antitumor effects could be, at least in part, explained by the inhibition exerted by gefitinib of an IFN-α-induced EGF-dependent survival pathway, which involves extracellular signal-regulated kinase activation. These results provide a rationale for the clinical evaluation of gefitinib in combination with IFN-α in HNSCC.
Naturally occurring T-cell response against mutated p21 ras oncoprotein in pancreatic cancer.
Authors: Kubuschok Boris , Neumann Frank , Breit Rainer , Sester Martina , Schormann Claudia , Wagner Claudia , Sester Urban , Hartmann Frank , Wagner Mathias , Remberger Klaus , Schilling Martin , Pfreundschuh Michael
Published: March 2006

Mutated p21 ras proteins (muRas) are present in approximately 90% of pancreatic adenocarcinomas and express mutants which can function as cancer-specific antigens. To evaluate the frequency and magnitude of the natural T-cell response against muRas in 19 HLA-A2-positive patients with muRas-positive pancreatic carcinomas, antigen-experienced T lymphocytes in fresh peripheral blood mononuclear cells were shown by IFN-gamma enzyme-linked immunospot using muRas peptides (5-21) that encompass both HLA class I (HLA-A2)- and class II-restricted (HLA-DRB1) epitopes. Six of 19 patients (32%) were found to have a specific T-cell response against individual mutation-specific ras(5-21) but not against other ras mutations or wild-type ras. In contrast, none of 19 healthy subjects had T cells specifically secreting IFN-gamma (P = 0.004). The T-cell response consisted of both CD8(+) and CD4(+) T cells but was dominated by CD8 T cells in three of four patients. MuRas(5-14) and muRas(6-14) were shown to specifically induce CD8(+) T-cell mediated cytotoxicity against HLA-A2-positive, muRas-bearing pancreatic carcinoma cells. The T-cell response was not correlated with prognostic or clinical variables such as tumor-node-metastasis status, stage, or survival. In conclusion, a natural T-cell response against muRas proteins that could be exploited for immunostimulatory therapeutic approaches has been shown in a significant proportion of patients with pancreatic cancer.
Tumor Vascular Permeabilization by Vascular-Targeting Photosensitization: Effects, Mechanism, and Therapeutic Implications
Authors: Chen Bin , Pogue Brian W. , Luna Jorge M. , Hardman Rulon L. , Hoopes P. Jack , Hasan Tayyaba
Published: March 2006

Purpose: Loss of vascular barrier function has been observed shortly following vascular-targeting photodynamic therapy. However, the mechanism involved in this event is still not clear, and the therapeutic implications associated with this pathophysiologic change have not been fully explored.

Experimental Design: The effect of vascular-targeting photodynamic therapy on vascular barrier function was examined in both s.c. and orthotopic MatLyLu rat prostate tumor models and endothelial cells in vitro, using photosensitizer verteporfin. Vascular permeability to macromolecules (Evans blue-albumin and high molecular weight dextran) was assessed with dye extraction (ex vivo) and intravital microscopy (in vivo) methods. Intravital microscopy was also used to monitor tumor vascular functional changes after vascular-targeting photodynamic therapy. The effects of photosensitization on monolayer endothelial cell morphology and cytoskeleton structures were studied with immunofluorescence staining.

Results: Vascular-targeting photodynamic therapy induced vascular barrier dysfunction in the MatLyLu tumors. Thus, tumor uptake of macromolecules was significantly increased following photodynamic therapy treatments. In addition to vascular permeability increase, blood cell adherence to vessel wall was observed shortly after treatment, further suggesting the loss of endothelial integrity. Blood cell adhesion led to the formation of thrombi that can occlude blood vessels, causing vascular shutdown. However, viable tumor cells were often detected at tumor periphery after vascular-targeting photodynamic therapy. Endothelial cell barrier dysfunction following photodynamic therapy treatment was also observed in vitro by culturing monolayer endothelial cells on Transwell inserts. Immunofluorescence study revealed microtubule depolymerization shortly after photosensitization treatment and stress actin fiber formation thereafter. Consequently, endothelial cells were found to retract, and this endothelial morphologic change led to the formation of intercellular gaps.

Conclusions: Vascular-targeting photodynamic therapy permeabilizes blood vessels through the formation of endothelial intercellular gaps, which are likely induced via endothelial cell microtubule depolymerization following vascular photosensitization. Loss of endothelial barrier function can ultimately lead to tumor vascular shutdown and has significant implications in drug transport and tumor cell metastasis.
Somatic Mutations of Epidermal Growth Factor Receptor in Bile Duct and Gallbladder Carcinoma
Authors: Leone Francesco , Cavalloni Giuliana , Pignochino Ymera , Sarotto Ivana , Ferraris Renato , Piacibello Wanda , Venesio Tiziana , Capussotti Lorenzo , Risio Mauro , Aglietta Massimo
Published: March 2006

Objective: Conventional therapies are still unsuccessful in patients with carcinoma arising from the biliary tract. Somatic mutations of the epidermal growth factor receptor (EGFR) gene and the activation of its downstream pathways predict the sensitivity to small-molecule inhibitors in non–small cell lung carcinoma. Therefore, we analyzed EGFR mutations and related pathways in gallbladder and bile duct carcinomas to consider the possible application of these alternative therapeutic strategies.

Experimental Design: Forty paraffin-embedded samples, including intrahepatic or extrahepatic cholangiocarcinoma and gallbladder carcinoma, were studied after tumor cell isolation by laser microdissection and sequencing of EGFR tyrosine kinase domain (exons 18-21). Activation of EGFR pathway was studied by evaluating phosphorylation of mitogen-activated protein kinase and Akt.

Results: None of the 40 specimens had mutations in exon 18; one had one missense point mutation in exon 19, two in exon 20, and three in exon 21. In addition, 36 of 40 specimens had the same silent mutation at codon 787 in exon 20, which was also found in peripheral blood cells from healthy donors. Tumor samples harboring EGFR mutation had phosphorylation of one or both downstream transducers analyzed.

Conclusions: This is the first evidence of somatic mutations of the EGFR gene in bile duct carcinoma. Our findings suggest that a subgroup of patients with cholangiocarcinoma or gallbladder carcinoma exhibits somatic mutations of EGFR in the tyrosine kinase domain that can elicit cell signals sustaining survival and proliferation. These tumors might be further evaluated for their susceptibility to small-molecule inhibitor treatment.
Purification and Characterization of Human Kallikrein 11, a Candidate Prostate and Ovarian Cancer Biomarker, from Seminal Plasma
Authors: Luo Liu-Ying , Shan Shannon J.C. , Elliott Marc B. , Soosaipillai Antoninus , Diamandis Eleftherios P.
Published: March 2006

Purpose: Preliminary data suggest that hK11 is a novel serum biomarker for prostate and ovarian cancer. To examine the enzymatic characteristics of hK11, we purified and functionally characterized native hK11 from seminal plasma.

Experimental Design: hK11 was purified from seminal plasma by immunoaffinity chromatography and characterized by kinetic analysis, electrophoresis, Western blots, and mass spectrometry.

Results: hK11 is present in seminal plasma at concentrations ranging from 2 to 37 μg/mL. Using immunoaffinity chromatography and reverse-phase high-performance liquid chromatography, we purified hK11 to homogeneity. In seminal plasma, hK11 is present as a free enzyme of ∼40 kDa. About 40% of hK11 is enzymatically active, whereas the rest is inactivated by internal cleavage after Arg156 (Genbank accession no. AF164623), which generates two peptides of ∼20 kDa, connected by internal disulfide bonds. Purified hK11 possesses trypsin-like activity and cleaves synthetic peptides after arginine but not lysine residues. It does not cleave chymotrypsin substrates. Antithrombin, α1-antichymotrypsin, α2-antiplasmin, and α1-antitrypsin have no effect on hK11 activity and do not form complexes with hK11 in vitro. The strongest inhibitor, APMSF, completely inhibited hK11 activity at a concentration of 2.5 mmol/L. Aprotinin and an hK11-specific monoclonal antibody inhibited hK11 activity up to 40%. Plasmin is a strong candidate for cleaving hK11 at Arg156.

Conclusion: This is the first report on purification and characterization of native hK11. We speculate that hK11, along with other kallikreins, proteases, and inhibitors, participates in a cascade enzymatic pathway responsible for semen liquefaction after ejaculation.
Comparison of the expression and prognostic significance of differentiation markers between diffuse large B-cell lymphoma of central nervous system origin and peripheral nodal origin.
Authors: Lin Ching-Hung , Kuo Kuan-Ting , Chuang Shih-Sung , Kuo Sung-Hsin , Chang Julia Hueimei , Chang Kung-Chao , Hsu Hui-Chen , Tien Hwei-Fang , Cheng Ann-Lii
Published: March 2006

PURPOSE: Whether diffuse large B-cell lymphoma (DLBCL) of primary central nervous system origin (PCNSL) is biologically different from DLBCL of peripheral nodal origin (NL) remains unclear. The purpose of this study was to compare the expression frequencies and prognostic significance of a panel of cell differentiation markers between these two disease entities. EXPERIMENTAL DESIGN: This study included HIV-unrelated patients with PCNSL (n = 51) and NL (n = 72) treated at four hospitals in Taiwan for whom archival tumor tissue was available. Immunohistochemistry for CD10, BCL-6, MUM-1, vs38c, CD138, and BCL-2 was done. CD10, BCL-6, and MUM-1 expression results were used to classify all cases into the germinal center B-cell (GCB) or the non-GCB subgroup. The prognostic significances of clinical and immunophenotypic markers were evaluated. RESULTS: Nuclear MUM-1 expression was significantly higher in PCNSL than in NL (P < 0.001; 84% versus 53%). PCNSL tumors were more frequently classified into the non-GCB subgroup than NL tumors (P = 0.020; 78% versus 62%). For patients with PCNSL, univariate analysis showed that patients with BCL-6 expression had a trend towards longer survival (P = 0.073; median survival, 25.3 versus 7.3 months), and multivariate analysis showed BCL-6 was an independent prognostic factor (P = 0.026). For patients with NL, both of univariate (P = 0.003) and multivariate analyses (P = 0.002) showed that GCB was significantly associated with favorable survival. CONCLUSION: The higher frequency of non-GCB subclassification, which was mainly contributed by nuclear MUM-1 expression in PCNSL implies that it has a more differentiated cellular origin than NL. BCL-6 expression in patients with PCNSL and GCB subgroup in patients with NL were favorable prognostic factors.
p8 Is a New Target of Gemcitabine in Pancreatic Cancer Cells
Authors: Giroux Valentin , Malicet Cédric , Barthet Marc , Gironella Meritxell , Archange Cendrine , Dagorn Jean-Charles , Vasseur Sophie , Iovanna Juan L.
Published: March 2006

Gemcitabine is the only available chemotherapeutic treatment of pancreatic cancers. It is, however, moderately effective, showing a tumor response rate of only 12%. The aim of this work was to identify new pathways involved in the resistance of pancreatic cancer cells to gemcitabine, in the hope of developing new adjuvant strategies to enhance its therapeutic efficacy. Comparison of gene expression patterns of five human pancreatic cancer cell lines showing different degrees of resistance to gemcitabine revealed specific overexpression of several genes in the most resistant. One of them encoded the antiapoptotic p8 protein. We found that (a) knocking down p8 expression in gemcitabine-resistant cells promoted cell death and increased caspase-3 activity; (b) forced overexpression of p8 in gemcitabine-sensitive cells increased their resistance to gemcitabine-induced apoptosis; and (c) gemcitabine down-regulated p8 mRNA expression. These results suggest that, in pancreatic cancer cells, a large part of gemcitabine-induced apoptosis results from the inhibition of the constitutive antiapoptotic activity of p8. Hence, targeting the p8-associated pathway could be a new adjuvant therapy improving the response of patients with pancreatic cancer to gemcitabine treatment.
MOPPEBVCAD Chemotherapy with Limited and Conditioned Radiotherapy in Advanced Hodgkin's Lymphoma: 10-Year Results, Late Toxicity, and Second Tumors
Authors: Gobbi Paolo G. , Broglia Chiara , Levis Alessandro , La Sala Antonio , Valentino Francesco , Chisesi Teodoro , Sacchi Stefano , Corbella Franco , Cavanna Luigi , Iannitto Emilio , Pavone Vincenzo , Molica Stefano , Corazza Gino Roberto , Federico Massimo
Published: March 2006

Purpose: MOPPEBVCAD (mechlorethamine, vincristine, procarbazine, prednisone, epidoxirubicin, bleomycin, vinblastine, lomustine, doxorubicin, and vindesine) chemotherapy with limited radiotherapy was devised in 1987 to reduce late toxicity and second tumor incidence while trying to improve effectiveness through increases of dose intensity and dose density. Late results, toxicity, and second tumor incidence were reviewed in all the patients treated.

Experimental Design: The drugs of three previous alternating regimens [CAD (lomustine, melphalan, and vindesine), MOPP (mechlorethamine, vincristine, procarbazine, and prednisone), and ABV (doxorubicin, bleomycin, and vinblastine)] were intensified and hybridized, the cumulative dose of mechlorethamine was lowered, and irradiation was delivered to no more than two sites either bulky or partially responding to chemotherapy.

Results: A total of 307 previously untreated advanced-stage patients underwent MOPPEBVCAD chemotherapy. Radiotherapy was delivered to 118 of 307 patients (38%). Remission was complete in 290 patients (94%). With a median follow-up of 114 months, 10-year overall, disease-free, and failure-free survival rates were 79%, 84%, and 71%, respectively. Forty-two patients relapsed and 60 died. The causes of death were Hodgkin's lymphoma in 36 patients, second neoplasms in 12, cardiorespiratory diseases in 4, pulmonary diseases in 2, and unknown in 6. Sixteen second tumors (of which nine were myelodysplasia and/or acute leukemia) were diagnosed in all. Outside this series of 307 patients, MOPPEBVCAD obtained complete responses in 12 of 15 relapsed and 9 of 9 refractory patients who had previously been treated with other regimens.

Conclusions: Clinical response and long-term results are very satisfactory, whereas the second tumor incidence was lower than would have been expected with MOPP analogues. Given its response/late toxicity balance, MOPPEBVCAD does not undermine the leading role of ABVD as first-line regimen but can be indicated as a very effective second-line conventional therapy.
Guggulsterone Inhibits Osteoclastogenesis Induced by Receptor Activator of Nuclear Factor-κB Ligand and by Tumor Cells by Suppressing Nuclear Factor-κB Activation
Authors: Ichikawa Haruyo , Aggarwal Bharat B.
Published: March 2006

Bone resorption is commonly associated with aging and with certain types of cancer, including multiple myeloma and breast cancer. What induces bone resorption is not fully understood, but the role of osteoclasts is well established. Recently, receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL), a member of the tumor necrosis factor superfamily, was implicated as a major mediator of bone resorption, suggesting that agents that can suppress RANKL signaling have the potential to inhibit bone resorption or osteoclastogenesis. Guggulsterone [4,17(20)-pregnadiene-3,16-dione], isolated from the guggul tree Commiphora mukul and used to treat osteoarthritis and bone fractures, was recently shown to antagonize the farnesoid X receptor, decrease the expression of bile acid–activated genes, and suppress the NF-κB activation induced by various carcinogens. We investigated whether guggulsterone could modulate RANKL signaling and osteoclastogenesis induced by RANKL or tumor cells. We found that treatment of monocytes with guggulsterone suppressed RANKL-activated NF-κB activation (as indicated by gel-shift assay) and that this suppression correlated with inhibition of IκBα kinase and phosphorylation and degradation of IκBα, an inhibitor of NF-κB. Guggulsterone also suppressed the differentiation of monocytes to osteoclasts in a dose-dependent and time-dependent manner. Suppression of osteoclastogenesis by the NF-κB-specific inhibitory peptide implies a link between NF-κB and osteoclastogenesis. Finally, differentiation to osteoclasts induced by coincubating human breast tumor cells (MDA-MB-468) or human multiple myeloma (U266) cells with monocytes was also completely suppressed by guggulsterone. Collectively, our results indicate that guggulsterone suppresses RANKL and tumor cell–induced osteoclastogenesis by suppressing the activation of NF-κB.
p95HER-2 Predicts Worse Outcome in Patients with HER-2-Positive Breast Cancer
Authors: Sáez Rosana , Molina Miguel A. , Ramsey Elizabeth E. , Rojo Federico , Keenan Edward J. , Albanell Joan , Lluch Ana , García-Conde Javier , Baselga José , Clinton Gail M.
Published: March 2006

Background: The HER-2 receptor undergoes a proteolytic cleavage generating an NH2-terminally truncated fragment, p95HER-2, that is membrane-associated and tyrosine-phosphorylated. We have reported that p95HER-2, but not the full-length receptor, p185HER-2, correlated with the extent of lymph node involvement in patients with breast cancer and its expression was significantly enhanced in nodal metastatic tissue. These facts suggested an important role for p95HER-2 either as a marker or cause of metastasis and poor outcome in breast cancer. In this work, we have studied the prognostic value of p95HER-2 in breast cancer.

Methods: Primary breast tumor tissues (n = 483) were from surgical resections conducted in hospitals in two different countries: the U.S. (n = 334) and Spain (n = 149). HER-2 protein forms, including p185HER-2 and p95HER-2, were examined in extracts of primary breast tumors by Western blot analysis. The levels of the two forms (high or low) were tested for association with other clinicopathologic factors and for correlation with disease-free survival.

Results: The median follow-up was 46 months. A high level of p95HER-2 in primary tumor tissue correlated with reduced 5-year disease-free survival (hazard ratio, 2.55; 95% confidence interval, 2.13-8.01; P < 0.0001). The median time for disease-free survival was 32 versus 139 months in patients with low levels of p95HER-2. In comparison, high levels of the full-length p185HER-2 did not significantly correlate with poor outcome (P > 0.1). Multivariate analysis revealed that high p95HER-2 was an independent predictor of disease-free survival (hazard ratio, 1.59; 95% confidence interval, 1.246-1.990; P = 0.0004).

Conclusions: p95HER-2 expression is an independent prognostic factor in breast cancer and defines a group of patients with HER-2-positive breast cancer with significantly worse outcome.
Stomatin-like Protein 2 Is Overexpressed in Cancer and Involved in Regulating Cell Growth and Cell Adhesion in Human Esophageal Squamous Cell Carcinoma
Authors: Zhang Liyong , Ding Fang , Cao Wenfeng , Liu Zhongmin , Liu Wei , Yu Zaicheng , Wu Yu , Li Wendong , Li Yanda , Liu Zhihua
Published: March 2006

Purpose: Stomatin-like protein 2 (SLP-2) is a novel and unusual stomatin homologue of unknown functions. It has been implicated in interaction with erythrocyte cytoskeleton and presumably other integral membrane proteins, but not directly with the membrane bilayer. We show here the involvement of SLP-2 in human esophageal squamous cell carcinoma (ESCC), lung cancer, laryngeal cancer, and endometrial adenocarcinoma and the effects of SLP-2 on ESCC cells.

Experimental Design: Previous work of cDNA microarray in our laboratory revealed that SLP-2 was significantly up-regulated in ESCC. The expression of SLP-2 was further evaluated in human ESCC, lung cancer, laryngeal cancer, and endometrial adenocarcinoma by semiquantitative reverse transcription-PCR, Western blot, and immunohistochemistry. Mutation detection of SLP-2 exons was done by PCR and automated sequencing. Antisense SLP-2 eukaryotic expression plasmids were constructed and transfected into human ESCC cell line KYSE450. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, clonogenecity assay, flow cytometry assay, nude mice tumorigenetic assay, and cell attachment assay were done to investigate the roles of SLP-2 gene.

Results: All tumor types we tested showed overexpression of SLP-2 compared with their normal counterparts (P ≤ 0.05). Moreover, immunohistochemistry analysis of mild dysplasia, severe dysplasia, and ESCC showed that overexpression of SLP-2 occurred in premalignant lesions. Mutation analysis indicated that no mutation was found in SLP-2 exons. KYSE450 cells transfected with antisense SLP-2 showed decreased cell growth, proliferation, tumorigenecity, and cell adhesion.

Conclusions: SLP-2 was first identified as a novel cancer-related gene overexpressed in human ESCC, lung cancer, laryngeal cancer, and endometrial adenocarcinoma. Decreased cell growth, cell adhesion, and tumorigenesis in the antisense transfectants revealed that SLP-2 may be important in tumorigenesis.
Expression of Synovial Sarcoma X (SSX) Antigens in Epithelial Ovarian Cancer and Identification of SSX-4 Epitopes Recognized by CD4+ T Cells
Authors: Valmori Danila , Qian Feng , Ayyoub Maha , Renner Christoph , Merlo Andrea , Gjnatic Sacha , Stockert Elisabeth , Driscoll Deborah , Lele Shashikant , Old Lloyd J. , Odunsi Kunle
Published: March 2006

Purpose: Synovial sarcoma X (SSX) breakpoint genes are expressed in a variety of cancers but not in normal tissues, except for testis, and are potential targets for immunotherapy. The aims of this study were to determine the expression and immunogenicity of these antigens in patients with epithelial ovarian cancer (EOC).

Experimental Design: SSX-1-, SSX-2-, and SSX-4-specific reverse transcription-PCR were done on a panel of EOC specimens. Sera from a subgroup of the patients were tested for SSX-2 and SSX-4 antibody by ELISA and recombinant antigen expression on yeast surface (RAYS). In vitro stimulation of peripheral blood mononuclear cells from a patient bearing SSX-4-expressing tumor with a pool of long peptides spanning the protein sequence was used for assessment of SSX-4-specific CD4+ T cells recognizing distinct antigenic sequences restricted by HLA class II alleles.

Results: Our results indicate expression of SSX-1, SSX-2, and SSX-4 in 2.5%, 10%, and 16% of 120 EOC specimens, respectively. When all three SSX antigens are considered, aberrant expression was found in 26% of ovarian tumors. Antibodies to SSX-2 and SSX-4 were detectable by ELISA and RAYS in two patients. SSX-4-specific CD4+ T cells recognizing two previously undescribed SSX-4-derived T-cell epitopes in association with HLA-DR (SSX-4: 51-70 and SSX-4: 61-180) were identified.

Conclusions: Our study shows aberrant expression of SSX antigens in a proportion of patients with EOC. The evidence of humoral immunity to SSX-2 and SSX-4, and SSX-4-specific CD4+ T cells among circulating lymphocytes in patients with antigen expressing EOC suggest that these antigens are attractive targets for specific immunotherapy in EOC.
Lovastatin Protects Human Endothelial Cells from Killing by Ionizing Radiation without Impairing Induction and Repair of DNA Double-Strand Breaks
Authors: Nübel Tobias , Damrot Julia , Roos Wynand P. , Kaina Bernd , Fritz Gerhard
Published: March 2006

Purpose: 3-hydroxy-3-methylglutaryl CoA reductase inhibitors (statins) are frequently used lipid-lowering drugs. Moreover, they are reported to exert pleiotropic effects on cellular stress responses, proliferation, and apoptosis. Whether statins affect the sensitivity of primary human cells to ionizing radiation (IR) is still unknown. The present study aims at answering this question.

Experimental Design: The effect of lovastatin on IR-provoked cytotoxicity was analyzed in primary human umbilical vein endothelial cells (HUVEC). To this end, cell viability, proliferation, and apoptosis as well as DNA damage–related stress responses were investigated.

Results: The data show that lovastatin protects HUVEC from IR-induced cell death. Lovastatin did not confer radioresistance to human fibroblasts. The radioprotective, antiapoptotic effect of lovastatin was observed at low, physiologically relevant dose level (1 μmol/L). Lovastatin affected various IR-induced stress responses in HUVEC: It attenuated the increase in p53/p21 protein level and impaired the activation of nuclear factor-κB, Chk-1, and Akt kinase but did not inhibit extracellular signal-regulated kinase activation. Exposure of HUVEC to IR did not change the level of Bax and Bcl-2 and did not cause activation of caspase-3, indicating that radioprotection by lovastatin does not depend on the modulation of the mitochondrial death pathway. Also, IR-induced DNA double-strand break formation and repair were not influenced by lovastatin.

Conclusions: The data show that lovastatin has multiple inhibitory effects on IR-stimulated DNA damage–dependent stress responses in HUVEC. Because lovastatin causes radioresistance, it might be useful in the clinic for attenuating side effects of radiation therapy that are related to endothelial cell damage.
Increased Expression of Leptin and the Leptin Receptor as a Marker of Breast Cancer Progression: Possible Role of Obesity-Related Stimuli
Authors: Garofalo Cecilia , Koda Mariusz , Cascio Sandra , Sulkowska Mariola , Kanczuga-Koda Luiza , Golaszewska Jolanta , Russo Antonio , Sulkowski Stanislaw , Surmacz Eva
Published: March 2006

Purpose: Recent in vitro studies suggested that the autocrine leptin loop might contribute to breast cancer development by enhancing cell growth and survival. To evaluate whether the leptin system could become a target in breast cancer therapy, we examined the expression of leptin and its receptor (ObR) in primary and metastatic breast cancer and noncancer mammary epithelium. We also studied whether the expression of leptin/ObR in breast cancer can be induced by obesity-related stimuli, such as elevated levels of insulin, insulin-like growth factor-I (IGF-I), estradiol, or hypoxic conditions.

Experimental Design: The expression of leptin and ObR was examined by immunohistochemistry in 148 primary breast cancers and 66 breast cancer metastases as well as in 90 benign mammary lesions. The effects of insulin, IGF-I, estradiol, and hypoxia on leptin and ObR mRNA expression were assessed by reverse transcription-PCR in MCF-7 and MDA-MB-231 breast cancer cell lines.

Results: Leptin and ObR were significantly overexpressed in primary and metastatic breast cancer relative to noncancer tissues. In primary tumors, leptin positively correlated with ObR, and both biomarkers were most abundant in G3 tumors. The expression of leptin mRNA was enhanced by insulin and hypoxia in MCF-7 and MDA-MB-231 cells, whereas IGF-I and estradiol stimulated leptin mRNA only in MCF-7 cells. ObR mRNA was induced by insulin, IGF-I, and estradiol in MCF-7 cells and by insulin and hypoxia in MDA-MB-231 cells.

Conclusions: Leptin and ObR are overexpressed in breast cancer, possibly due to hypoxia and/or overexposure of cells to insulin, IGF-I, and/or estradiol.
A study of the biological receptor activator of nuclear factor-kappaB ligand inhibitor, denosumab, in patients with multiple myeloma or bone metastases from breast cancer.
Authors: Body Jean-Jacques , Facon Thierry , Coleman Robert E , Lipton Allan , Geurs Filip , Fan Michelle , Holloway Donna , Peterson Mark C , Bekker Pirow J
Published: March 2006

PURPOSE: Receptor activator of nuclear factor-kappaB ligand (RANKL) is essential for the differentiation, function, and survival of osteoclasts, which play a key role in establishment and propagation of skeletal disease in patients with multiple myeloma or bone metastases as well as many other skeletal diseases. Denosumab (AMG 162), a fully human monoclonal antibody to RANKL, was developed to treat patients with skeletal diseases. EXPERIMENTAL DESIGN: This was a randomized, double-blind, double-dummy, active-controlled, multicenter study to determine the safety and efficacy of denosumab in patients with breast cancer (n = 29) or multiple myeloma (n = 25) with radiologically confirmed bone lesions. Patients received a single dose of either denosumab (0.1, 0.3, 1.0, or 3.0 mg/kg s.c.) or pamidronate (90 mg i.v.). Bone antiresorptive effect was assessed by changes in urinary and serum N-telopeptide levels. Pharmacokinetics of denosumab also were assessed. RESULTS: Following a single s.c. dose of denosumab, levels of urinary and serum N-telopeptide decreased within 1 day, and this decrease lasted through 84 days at the higher denosumab doses. Pamidronate also decreased bone turnover, but the effect diminished progressively through follow-up. Denosumab injections were well tolerated. Mean half-lives of denosumab were 33.3 and 46.3 days for the two highest dosages. CONCLUSIONS: A single s.c. dose of denosumab given to patients with multiple myeloma or bone metastases from breast cancer was well tolerated and reduced bone resorption for at least 84 days. The decrease in bone turnover markers was similar in magnitude but more sustained than with i.v. pamidronate.
5,6-Dimethylxanthenone-4-Acetic Acid in the Treatment of Refractory Tumors: a Phase I Safety Study of a Vascular Disrupting Agent
Authors: McKeage Mark J. , Fong Peter , Jeffery Mark , Baguley Bruce C. , Kestell Phil , Ravic Miroslav , Jameson Michael B.
Published: March 2006

This phase I safety study aimed to identify the optimal dose of the vascular disrupting agent 5,6-dimethylxanthenone-4-acetic acid (DMXAA) for combination studies. Using a crossover design, 15 patients with refractory tumors were allocated randomly to receive six sequential doses of DMXAA (300, 600, 1,200, 1,800, 2,400, and 3,000 mg m−2), each given once-weekly as a 20-minute i.v. infusion. The drug was generally well tolerated. Transient, moderate increases in the heart rate–corrected cardiac QT interval occurred at the two highest doses. DMXAA produced transient dose-dependent increases in blood pressure. Transient, dose-related visual disturbances occurred at the two highest doses. No significant changes in Ktrans and kep were observed but Ve, a secondary dynamic contrast–enhanced magnetic resonance imaging variable, increased significantly after giving DMXAA. At 1,200 mg m−2, the Cmax and the area under the concentration-time curve over 24 hours for total and free DMXAA plasma concentrations were 315 ± 25.8 μg/mL, 29 ± 6.4 μg/mL·d, 8.0 ± 1.77 μg/mL, and 0.43 ± 0.07 μg/mL·d, respectively. Plasma levels of the vascular damage biomarker 5-hydroxyindoleacetic acid increased in the 4 hours after treatment in a dose-dependent fashion up to 1,200 mg m−2, with a plateau thereafter. Doses in the range of 1,200 mg m−2 have been selected for further studies (phase II combination studies with taxanes and platins are under way) because this dose produced no significant effect on heart rate–corrected cardiac QT interval, produced near maximum levels of 5-hydroxyindoleacetic acid, achieved DMXAA plasma concentrations within the preclinical therapeutic range, and was well tolerated.
Biological Significance of Isolated Tumor Cells and Micrometastasis in Lymph Nodes Evaluated Using a Green Fluorescent Protein–Tagged Human Gastric Cancer Cell Line
Authors: Yokoyama Hiroyuki , Nakanishi Hayao , Kodera Yasuhiro , Ikehara Yuzuru , Ohashi Norifumi , Ito Yuichi , Koike Masahiko , Fujiwara Michitaka , Tatematsu Masae , Nakao Akimasa
Published: March 2006

Purpose: The biological significance of isolated tumor cells and micrometastasis in lymph node defined by the International Union against Cancer remains essentially unknown because of the lack of appropriate animal models. In the present study, we developed a lymph node micrometastasis model featuring a human gastric cancer cell line tagged with green fluorescent protein gene (GCIY-EGFP), which allows visualization of even isolated tumor cells in the development of metastasis without histologic procedure. Using this model, we investigated the effect of surgery and chemotherapy on the growth of early-phase metastasis formation in the lymph nodes.

Experimental Design: The time course of spontaneous inguinal lymph node metastasis after s.c. inoculation of GCIY-EGFP cells into nude mice was examined with fluorescence dissecting microscopy. Then, the effects of surgical removal of the primary tumor with or without anti-asialo GM1 treatment or postoperative chemotherapy on the growth of isolated tumor cells and micrometastasis in the lymph nodes were examined.

Results: GCIY-EGFP cells were found to metastasize spontaneously to the inguinal lymph nodes to form isolated tumor cells, micrometastasis, and, finally, develop macroscopic metastasis at 1 to 2, 3 to 5, and 5 weeks postinjection, respectively. When the primary tumors were removed within 2 weeks of inoculation, isolated tumor cells, but not micrometastasis, in the lymph nodes regressed by 4 weeks after surgery in all the mice examined (five of five). This spontaneous regression of isolated tumor cells was completely reversed by anti-asialo GM1 treatment, which could deplete natural killer cells effectively in nude mice. Chemotherapy following resection of the primary tumor at an early stage partially eliminated the remaining micrometastasis in the lymph nodes.

Conclusions: These results suggest that isolated tumor cells in the regional lymph nodes regressed by removal of the primary tumor mainly via natural killer cell–mediated antitumor activity and that micrometastasis in the lymph nodes could be effectively eliminated by the postoperative chemotherapy.
Prognostic value of indoleamine 2,3-dioxygenase expression in colorectal cancer: effect on tumor-infiltrating T cells.
Authors: Brandacher Gerald , Perathoner Alexander , Ladurner Ruth , Schneeberger Stefan , Obrist Peter , Winkler Christiana , Werner Ernst R , Werner-Felmayer Gabriele , Weiss Helmut G , G√∂bel Georg , Margreiter Raimund , K√∂nigsrainer Alfred , Fuchs Dietmar , Amberger Albert
Published: March 2006

PURPOSE: The pathologic interactions between tumor and host immune cells within the tumor microenvironment create an immunosuppressive network that promotes tumor growth and protects the tumor from immune attack. In this study, we examined the contribution of the immunomodulatory enzyme indoleamine 2,3-dioxygenase (IDO) on this phenomenon. EXPERIMENTAL DESIGN: Expression of IDO was analyzed in colorectal cancer cell lines by reverse transcription-PCR and functional enzyme activity was assessed by high-pressure liquid chromatography. Semiquantitative immunohistochemistry was used to evaluate IDO expression in the tissue samples of 143 patients with colorectal carcinoma, and was then correlated with the number of tumor-infiltrating T cells and clinical variables. RESULTS: In vitro IDO expression and functional enzyme activity in colorectal cancer cells was found to be strictly dependent on IFN-gamma stimulation. Immunohistochemical scores revealed IDO-high expression in 56 of 143 (39.2%) tumor specimens, whereas 87 of 143 (60.8%) cases showed low IDO expression levels. IDO-high expression was associated with a significant reduction of CD3+ infiltrating T cells (46.02 +/- 7.25) as compared with tissue samples expressing low IDO (19.42 +/- 2.50; P = 0.0003). Furthermore, IDO-high immunoreactivity significantly correlated with the frequency of liver metastases (P = 0.003). Kaplan-Meier analysis showed the crossing of survival curves at 45 months. By multivariate Cox's analysis, IDO-high expression emerged as an independent prognostic variable (<45 months, P = 0.006; >45 months, P = 0.04). CONCLUSION: IDO-high expression by colorectal tumor cells enables certain cancer subsets to initially avoid immune attack and defeat the invasion of T cells via local tryptophan depletion and the production of proapoptotic tryptophan catabolites. Thus, IDO significantly contributes to disease progression and overall survival in patients with colorectal cancer.
Computer-Assisted Analysis of Biopsy Specimen Microvessels Predicts the Outcome of Esophageal Cancers Treated with Chemoradiotherapy
Authors: Zhang Shi-chuan , Hironaka Shuichi , Ohtsu Atsushi , Yoshida Shigeaki , Hasebe Takahiro , Fukayama Masashi , Ochiai Atsushi
Published: March 2006

Purpose: A computer-assisted microvessel analysis system was developed to evaluate correlations between the architecture of biopsy specimen microvessels and the outcome for patients with esophageal cancer treated with chemoradiotherapy.

Experimental Design: Biopsy specimens from 51 patients with esophageal cancer (T2-3, any N, M0) treated with chemoradiotherapy were immunostained with an anti-CD31 antibody and quantified using computerized image analysis. We evaluated the association of several microvessel factors with overall survival, including the ratio of total microvessel perimeter to total tumor area (TP/TA), the tumor hypoxic ratio, and the ratio of total microvessel number to total tumor area (TN/TA). Results from traditional manual microvessel density (MVD) hotspot count and computerized hotspot count were compared and the relation between hotspot MVD count and survival rate was evaluated.

Results: The median follow-up time was 32 months. Both univariate and multivariate analyses revealed that computer-counted hotspot MVD and TN/TA and TP/TA ratios correlated significantly with the outcome of chemoradiotherapy. Kaplan-Meier survival curves showed that patients with high computer-counted hotspot MVDs and high TN/TA and TP/TA ratios had better overall survival rate than patients with low MVDs or ratios (P = 0.025, 0.008, and 0.031, respectively). Combining computer-counted MVD or TN/TA ratio with TP/TA ratio proved more predictive than any single factor. Two researcher-counted hotspot MVDs had no significant relation with outcome.

Conclusion: Computer-assisted tumor microvessel analysis is a powerful tool in predicting the outcome for patients with esophageal cancer treated with chemoradiotherapy because intraobserver and interobserver variability is minimized.
Oncogenic Property of Acrogranin in Human Uterine Leiomyosarcoma: Direct Evidence of Genetic Contribution in In vivo Tumorigenesis
Authors: Matsumura Noriomi , Mandai Masaki , Miyanishi Masanori , Fukuhara Ken , Baba Tsukasa , Higuchi Toshihiro , Kariya Masatoshi , Takakura Kenji , Fujii Shingo
Published: March 2006

To identify potential oncogenes that contribute to the development of uterine leiomyosarcoma, we conducted a cDNA microarray analysis between normal uterine smooth muscle and uterine leiomyosarcoma. We found that acrogranin (also named PCDGF or progranulin) is overexpressed in uterine leiomyosarcoma. With immunohistochemical staining of 12 leiomyosarcoma cases, we verified acrogranin expression in tumor cells. Furthermore, the intensity of acrogranin expression correlated with high histologic grade and poor prognosis. To directly analyze the oncogenic properties of acrogranin, we established an immortalized uterine smooth muscle cell line by transfection of human telomerase reverse transcriptase into primary culture. This cell line retained the original characteristics of uterine smooth muscle cells, including spindle-shaped extension as well as expression of vimentin, estrogen receptor α, progesterone receptor, and α smooth muscle actin. Transfection of acrogranin into the immortalized uterine smooth muscle cells resulted in colony formation in soft agar, but the diameter of the colonies did not exceed 100 μm. Transfection of both acrogranin and SV40 early region (SV40ER) into the immortalized uterine smooth muscle cells resulted in an increased number of colonies and increased colony size in soft agar versus transfection of SV40ER alone. We show that only immortalized uterine smooth muscle cells expressing both acrogranin and SV40ER are capable of tumor formation in nude mice. Thus, acrogranin is overexpressed in uterine leiomyosarcoma cells, particularly in high-grade cases, and forced expression of acrogranin in immortalized uterine smooth muscle cells contributes to malignant transformation, which suggest that acrogranin plays an important role in the pathogenesis of uterine leiomyosarcoma.
A phase I and pharmacokinetic study of fixed-dose selenomethionine and irinotecan in solid tumors.
Authors: Fakih Marwan G , Pendyala Lakshmi , Smith Patrick F , Creaven Patrick J , Reid Mary E , Badmaev Vladimir , Azrak Rami G , Prey Joshua D , Lawrence David , Rustum Youcef M
Published: March 2006

PURPOSE: We conducted a phase I study to determine the maximum tolerated dose (MTD) of irinotecan with fixed, nontoxic high dose of selenomethionine. EXPERIMENTAL DESIGN: Selenomethionine was given orally as a single daily dose containing 2,200 mug of elemental selenium (Se) starting 1 week before the first dose of irinotecan. Irinotecan was given i.v. once weekly x 4 every 6 weeks (one cycle). The starting dose of irinotecan was 125 mg/m(2)/wk. Escalation occurred in cohorts of three patients until the MTD was defined. Pharmacokinetic studies were done for selenium and irinotecan and its metabolites. RESULTS: Three of four evaluable patients at dose level 2 of irinotecan (160 mg/m(2)/wk) had a dose-limiting diarrhea. None of the six evaluable patients at dose level 1 (125 mg/m(2)/wk irinotecan) had a dose-limiting toxicity. One patient with history of irinotecan-refractory colon cancer achieved a partial response. The long half-life of selenium resulted in a prolonged accumulation towards steady-state concentrations. No significant changes in the pharmacokinetics of CPT-11, SN-38, or SN-38G were identified; however, the coadministration of selenomethionine significantly reduced the irinotecan biliary index, which has been associated with gastrointestinal toxicity. CONCLUSIONS: Selenomethionine at 2,200 mug/d did not allow the safe escalation of irinotecan beyond the previously defined MTD of 125 mg/m(2). None of the patients receiving 125 mg/m(2) of irinotecan had grade >2 diarrhea. Unexpected responses and disease stabilizations were noted in a highly refractory population. Further escalation of selenomethionine is recommended in future trials to achieve defined protective serum concentrations of selenium.