bluuebunny/crossref_metadata_2025 huggingface dataset:
High Expression of Neuropeptide Y Receptors in Tumors of the Human Adrenal Gland and Extra-Adrenal Paraganglia
Authors: Körner Meike , Waser Beatrice , Reubi Jean Claude
Published: September 2005

Purpose: Recently, a role of neuropeptide Y (NPY) in tumor biology was suggested based on the high density of NPY receptors in breast and ovarian cancers. The high frequency of NPY receptors in steroid hormone-producing ovarian sex cord-stromal tumors, together with the known influence of NPY on steroid hormone and catecholamine secretion in the rodent adrenal gland, led to the investigation of NPY receptor expression in the human adrenal gland and related tumors.

Experimental Design: Fifteen adrenal cortical tumors, 20 paragangliomas, 23 pheochromocytomas, 20 neuroblastomas, and 8 normal adrenal glands were investigated by in vitro NPY receptor autoradiography using 125I-labeled peptide YY in competition experiments with receptor subtype selective analogs.

Results: Ninety three percent of cortical tumors express Y1, 35% of pheochromocytomas and 61% of paragangliomas express Y1 and Y2, and 90% of neuroblastomas express Y2 receptors. The NPY receptors in pheochromocytomas, paragangliomas, and neuroblastomas are often expressed concomitantly with the NPY hormone detected immunohistochemically. The adrenal cortex strongly expresses Y1, whereas no NPY receptors are found in the adrenal medulla.

Conclusions: These receptor data suggest a role of NPY in adrenal cortical tumors and, together with the strong NPY innervation of the cortex, a physiologic role in the adrenal gland, mediated by Y1 receptors. These NPY receptors are a potential new molecular target for the therapy of malignant tumors.
Myeloma Cells Are Highly Sensitive to the Granule Exocytosis Pathway Mediated by WT1-Specific Cytotoxic T Lymphocytes
Authors: Azuma Taichi , Otsuki Takemi , Kuzushima Kiyotaka , Froelich Christopher J. , Fujita Shigeru , Yasukawa Masaki
Published: September 2005

Purpose: Because WT1 is a universal tumor antigen, we examined the sensitivity of myeloma cells to WT1-specific cytotoxic T lymphocyte (CTL)-mediated cytotoxicity.

Experimental Design: WT1 expression in hematologic malignant cells was examined by quantitative reverse transcription-polymerase chain reaction. The cytotoxicity of a WT1-specific CTL clone against hematologic malignant cells, including myeloma cells, was examined by standard chromium-51 release assays. The extent of membrane damage induced by purified perforin was examined. Induction of WT1-specific CTLs from the patients with multiple myeloma (MM) was attempted, and we examined their function against myeloma cells.

Results: The expression levels of WT1 mRNA in myeloma and lymphoma cells were significantly lower than that in acute leukemia cells. Although the WT1 expression levels in myeloma and lymphoma cells were almost same, only myeloma cells were lysed efficiently by WT1-specific CTLs in a HLA-restricted manner. The amounts of interferon-γ produced by WT1-specific CTLs in response to stimulation with myeloma cells and with lymphoma cells were almost the same, suggesting that WT1 protein is processed and expressed in the context of HLA class I molecules similarly on both myeloma and lymphoma cells. The extent of membrane damage induced by purified perforin appeared to be significantly higher in myeloma cells than in lymphoma cells. WT1-specific CTLs appeared to be present in patients with MM.

Conclusions: The present study has shown that susceptibility of membranes to perforin is an important factor determining the sensitivity of target cells to CTL-mediated cytotoxicity and that WT1 is an ideal target antigen for cellular immunotherapy of MM.
Potent Antitumor Activity of Novel Iron Chelators Derived from Di-2-Pyridylketone Isonicotinoyl Hydrazone Involves Fenton-Derived Free Radical Generation
Authors: Chaston Timothy B. , Watts Ralph N. , Yuan Jun , Richardson Des R.
Published: September 2005

Purpose: The development of novel and potent iron chelators as clinically useful antitumor agents is an area of active interest. Antiproliferative activity of chelators often relates to iron deprivation or stimulation of iron-dependent free radical damage. Recently, we showed that novel iron chelators of the di-2-pyridylketone isonicotinoyl hydrazone (PKIH) class have potent and selective antineoplastic activity (E. Becker, et al., Br. J. Pharmacol., 138: 819–30, 2003). In this study, we assessed the effects of the PKIH analogues on the redox activity of iron in terms of understanding their antitumor activity.

Experimental Design: We tested the PKIH analogues for their ability to promote iron-mediated ascorbate oxidation, benzoate hydroxylation, and plasmid degradation. Subsequent experiments assessed their ability to bind DNA, inhibit topoisomerase I, and cause DNA damage. To measure intracellular reactive oxygen species, we used the redox-sensitive probe, 2′,7′-dichloro-fluorescein-diacetate, to measure intracellular PKIH-dependent redox activity.

Results: The PKIH analogues had relatively little effect on ascorbate oxidation in the presence of Fe(III) but stimulated benzoate hydroxylation and plasmid DNA degradation in the presence of Fe(II) and H2O2. These ligands could not inhibit DNA topoisomerase I or cause DNA damage in intact cells. PKIH markedly increased the intracellular generation of reactive oxygen species, and this was inhibited by catalase. This enzyme also decreased the antiproliferative effect of PKIH, indicating H2O2 played a role in its cytotoxic activity.

Conclusions: Our results suggest that the antiproliferative effects of these chelators relates to intracellular iron chelation, followed by the stimulation of iron-mediated free radical generation via the so-formed iron complex.
Absence of a Correlation between the Presence of a Single Nucleotide Polymorphism in the Matrix Metalloproteinase 1 Promoter and Outcome in Patients of Chondrosarcoma
Authors: Fong Yi-Chin , Dutton Charyl M. , Cha Stephen S. , Garamszegi Nandor , Sim Franklin H. , Scully Sean P.
Published: September 2005

Purpose: Increased levels of matrix metalloproteinase 1 (MMP-1) expression have been associated with poor outcome in chondrosarcoma. The existence of a single nucleotide polymorphism creating an Ets-binding site in the MMP-1 promoter may be one mechanism for elevated MMP-1 transcription. The aim of our study was to identify the prevalence of this single nucleotide polymorphism (SNP) in chondrosarcoma patients, to determine its correlation with disease outcome, and to discern whether it could serve as a prognostic marker in patients with chondrosarcoma.

Experimental Design: Sixty-seven chondrosarcoma specimens were selected sequentially from an established tumor bank with a median duration of 47 months follow-up (range, 24 to 179 months). DNA was extracted, amplified with PCR, and sequenced to determine presence (GG) or absence of the Ets-binding site created by the SNP.

Results: Eighteen (27%) samples were homozygous for the absence of the Ets site, 34 (51%) were heterozygous for the SNP, and 15 (22%) were homozygous for the SNP. The 5-year overall survival rate for patients was 78, 80, and 84%, respectively (P = 0.5527). The disease-free survival rate was 16, 63, and 76%, respectively (P = 0.0801). The 5-year disease-free survival rate for patients with the homozygous G/G genotype was 16%, compared with 71% for patients who were either homozygous or heterozygous for the GG allele (P = 0.0444).

Conclusions: Despite a statistical correlation between MMP-1 gene expression and outcome in chondrosarcoma, this study demonstrates an absence of a correlation between the presence of the SNP and prognosis in patients with chondrosarcoma.
Combination Antiangiogenic and Androgen Deprivation Therapy for Prostate Cancer
Authors: Nicholson Brian , Gulding Kathryn , Conaway Mark , Wedge Stephen R. , Theodorescu Dan
Published: September 2005

Purpose: Androgen ablation therapy leads to mild regression or stabilization of prostate cancer, followed by progression to the fatal androgen-independent state. Whereas androgen ablation diminishes tumor angiogenesis by suppressing vascular endothelial growth factor (VEGF) production, androgen-independent disease is marked by androgen-independent VEGF expression. We examined combined androgen ablation and inhibition of VEGF signaling in an androgen-sensitive human prostate cancer xenograft model (LNCaP) that is known to develop androgen-independent growth after androgen ablation.

Experimental Design: N-(4-Bromo-2-fluorophenyl)-6-methoxy-7-[(1-methylpiperidin-4-yl)methoxy]quinazolin-4-amine (ZD6474) is an orally active inhibitor of VEGF receptor tyrosine kinase activity, with additional activity against epidermal growth factor receptor tyrosine kinase. ZD6474 (50 mg/kg/d, per os) was administered to groups of castrated and noncastrated athymic mice bearing established (4–616 mm3) LNCaP xenografts. To evaluate the extent of tumor regrowth after ZD6474, treatment was stopped after 40 days of continuous dosing, and subsequent tumor growth was monitored. Prostate-specific antigen expression was assessed to determine the effect of ZD6474 on androgen-regulated genes.

Results: In comparison with orchiectomy, ZD6474 treatment produced greater tumor growth inhibition (P < 0.001), inducing complete cytostasis for the duration of dosing. An analysis of serum prostate-specific antigen concentration and tumor weight indicated that ZD6474 did not have a direct effect on androgen-related gene expression. Combination therapy (castration plus ZD6474) produced a comparable therapeutic effect to treatment with ZD6474 alone (in noncastrated mice), for the duration of ZD6474 administration. However, when ZD6474 treatment was discontinued, the rate of tumor regrowth was significantly less in the combination group. Tumors from mice receiving combined treatment were also found to be more necrotic than tumors from mice receiving either androgen ablation or ZD6474 alone.

Conclusions: These data indicate that inhibition of VEGF signaling produces a highly significant inhibition of tumor growth in a human androgen-dependent prostate tumor model, which far exceeds that produced by androgen ablation alone. However, when ZD6474 treatment is removed, concurrent androgen ablation produces a greater inhibition of tumor regrowth than is observed in mice without androgen ablation. Increased necrosis observed in tumors from orchiectomized mice receiving ZD6474 also suggests benefit from combining anti-androgen and anti-VEGF signaling approaches.
The Influence of Androgen Deprivation Therapy on Dihydrotestosterone Levels in the Prostatic Tissue of Patients with Prostate Cancer
Authors: Nishiyama Tsutomu , Hashimoto Yutaka , Takahashi Kota
Published: September 2005

Purpose: The influence of androgen deprivation therapy on dihydrotestosterone levels in the prostatic tissue is not clearly known. Changes in dihydrotestosterone levels in the prostatic tissue during androgen deprivation therapy in the same patients have not been reported. We analyzed dihydrotestosterone levels in prostatic tissue before and after androgen deprivation therapy.

Experimental Design: A total of 103 patients who were suspected of having prostate cancer underwent prostatic biopsy. Sixty-nine patients were diagnosed as having prostate cancer whereas the remaining 34 were negative. Serum samples were collected before biopsy or prostatectomy. Dihydrotestosterone levels in prostatic tissue and serum were analyzed using liquid chromatography/electrospray ionization-mass spectrometry after polar derivatization. In 30 of the patients with prostate cancer, dihydrotestosterone levels in prostatic tissue were determined by performing rebiopsy or with prostate tissues excised after 6 months on androgen deprivation therapy with castration and flutamide.

Results: Dihydrotestosterone levels in prostate tissue after androgen deprivation therapy remained at ∼25% of the amount measured before androgen deprivation therapy. Dihydrotestosterone levels in serum decreased to ∼7.5% after androgen deprivation therapy. The level of dihydrotestosterone in prostatic tissue before androgen deprivation therapy was not correlated with the serum level of testosterone. Serum levels of adrenal androgens were reduced to ∼60% after androgen deprivation therapy.

Conclusions: The source of dihydrotestosterone in prostatic tissue after androgen deprivation therapy involves intracrine production within the prostate, converting adrenal androgens to dihydrotestosterone. Dihydrotestosterone still remaining in prostate tissue after androgen deprivation therapy may require new therapies such as treatment with a combination of 5α-reductase inhibitors and antiandrogens, as well as castration.
Granulin–Epithelin Precursor Overexpression Promotes Growth and Invasion of Hepatocellular Carcinoma
Authors: Cheung Siu Tim , Wong San Yu , Leung Ka Ling , Chen Xin , So Samuel , Ng Irene O. , Fan Sheung Tat
Published: September 2005

Purpose: Granulin–epithelin precursor (GEP) is a novel growth factor. Our earlier cDNA microarray study indicated that GEP was overexpressed in hepatocellular carcinoma (HCC). The aim of this study was to investigate the clinical significance of GEP expression and its potential as a therapeutic target in HCC.

Experimental Design: A total of 110 pairs of HCCs and adjacent nontumor liver tissues, and 22 normal liver tissues were examined. The GEP RNA level was examined by quantitative reverse transcription-PCR, and protein localization by immunohistochemistry. The GEP function was examined by transfection experiments.

Results: The RNA levels of the HCCs were significantly higher than those of the nontumor liver tissues and normal livers (P < 0.001). GEP protein staining was observed in tumor cytoplasm, and the GEP protein levels of the HCCs were also significantly higher than those of the nontumor liver tissues and normal livers (P < 0.001). The majority of HCCs demonstrated up-regulation of GEP protein compared with their adjacent liver tissues [79 (71.8%) of 110]. Positive correlation of GEP RNA with protein levels was observed in HCCs (P < 0.01). Strong GEP expression was associated with large HCCs, venous infiltration, and early intrahepatic recurrence (P < 0.05). Functional studies on the HCC cell line Hep3B demonstrated that reduction of GEP protein levels resulted in decreased cell prolifera-tion rates, tumor invasion ability, anchorage-independent growth in soft agar, and tumorigenicity in nude mice (P < 0.05).

Conclusion: GEP is an important factor for HCC growth, invasion, and metastasis. GEP has the potential to serve as a tumor marker and therapeutic target.
Efficacy of the Novel Camptothecin Gimatecan against Orthotopic and Metastatic Human Tumor Xenograft Models
Authors: De Cesare Michelandrea , Pratesi Graziella , Veneroni Silvia , Bergottini Raffaella , Zunino Franco
Published: September 2005

Purpose: Gimatecan, a novel oral lipophilic camptothecin characterized by favorable features at molecular/cellular level and by a promising profile of preclinical activity, is currently in clinical phase I/II. The aim of the study was to additionally investigate the therapeutic potential of the drug in human tumor xenografts growing in different organs as models representative of tumor growth in the clinical setting.

Experimental Design: The models include two orthotopic central nervous system tumors, two melanomas growing intracranially, and an ovarian carcinoma growing i.p. In addition, gimatecan was tested against experimental lung metastases of two tumor types (lung and ovarian carcinomas). Gimatecan was delivered by oral gavage according to various schedules (daily or intermittent). The time (in days) mice required to show evident signs of disease was used as end point for drug efficacy.

Results: Gimatecan was highly effective in delaying disease manifestations in all tumor systems investigated. In the intracranially growing tumors, a significant time increase (versus control mice) was achieved by the drug administered according to all of the schedules. In addition, almost all treated mice were alive and tumor-free at the end of the experiment in the metastatic models and in the ascitic ovarian tumor. The daily prolonged treatment schedule was the best one.

Conclusions: In all tumor systems investigated, including orthotopic tumor growth models and lung metastases, the oral administration of gimatecan showed a therapeutic benefit in terms of survival increase. The good oral availability allowed a prolonged daily treatment regimen, which seems the most promising to exploit the therapeutic potential of the drug.
Genetic Analysis of the
RNASEL
Gene in Hereditary, Familial, and Sporadic Prostate Cancer
Authors: Wiklund Fredrik , Jonsson Björn-Anders , Brookes Anthony J. , Strömqvist Linda , Adolfsson Jan , Emanuelsson Monica , Adami Hans-Olov , Augustsson-Bälter Katarina , Grönberg Henrik
Published: September 2005

Purpose: The RNASEL gene has been proposed as a candidate gene for the HPC1 locus through a positional cloning and candidate gene approach. Cosegregation between the truncating mutation E265X and disease in a hereditary prostate cancer (HPC) family and association between prostate cancer risk and the common missense variant R462Q has been reported. To additionally evaluate the possible role of RNASEL in susceptibility to prostate cancer risk, we performed a comprehensive genetic analysis of sequence variants in RNASEL in the Swedish population.

Experimental Design: Using 1624 prostate cancer cases and 801 unaffected controls, the truncating mutation E265X and five common sequence variants, including the two missense mutations R462Q and D541E, were evaluated for association between genotypes/haplotypes and prostate cancer risk.

Results: The prevalence of E265X carriers among unaffected controls and prostate cancer patients was almost identical (1.9 and 1.8% in controls and cases, respectively), and evidence for segregation of E265X with disease was not observed within any HPC family. Overall, the analyses of common sequence variants provided limited evidence for association with prostate cancer risk. We found a marginally significant inverse association between the missense mutation D541E and sporadic prostate cancer risk (odds ratio, 0.77; 95% confidence interval, 0.59–1.00) and reduced risk of prostate cancer in carriers of two different haplotypes being completely discordant.

Conclusions: Considering the high quality in genotyping and the size of this study, these results provide solid evidence against a major role of RNASEL in prostate cancer etiology in Sweden.
The CC Chemokine Receptor 4 as a Novel Specific Molecular Target for Immunotherapy in Adult T-Cell Leukemia/Lymphoma
Authors: Ishida Takashi , Iida Shinsuke , Akatsuka Yoshiki , Ishii Toshihiko , Miyazaki Mikinori , Komatsu Hirokazu , Inagaki Hiroshi , Okada Noriko , Fujita Teizo , Shitara Kenya , Akinaga Shiro , Takahashi Toshitada , Utsunomiya Atae , Ueda Ryuzo
Published: September 2005

Adult T-cell leukemia/lymphoma (ATLL) is a peripheral T-cell neoplasm with dismal prognosis, and no optimal therapy has been developed. We tested the defucosylated chimeric anti-CC chemokine receptor 4 (CCR4) monoclonal antibody, KM2760, to develop a novel immunotherapy for this refractory tumor. In the presence of peripheral blood mononuclear cells (PBMCs) from healthy adult donors, KM2760 induced CCR4-specific antibody-dependent cellular cytotoxicity (ADCC) against CCR4-positive ATLL cell lines and primary tumor cells obtained from ATLL patients. We next examined the KM2760-induced ADCC against primary ATLL cells in an autologous setting. Antibody-dependent cellular cytotoxicity mediated by autologous effector cells was generally lower than that mediated by allogeneic control effector cells. However, a robust ADCC activity was induced in some cases, which was comparable with that mediated by allogeneic effector cells. It suggests that the ATLL patients’ PBMCs retain substantial ADCC-effector function, although the optimal conditions for maximal effect have not yet been determined. In addition, we also found a high expression of FoxP3 mRNA and protein, a hallmark of regulatory T cells, in ATLL cells, indicating the possibility that ATLL cells originated from regulatory T cells. KM2760 reduced FoxP3 mRNA expression in normal PBMCs along with CCR4 mRNA by lysis of CCR4+ T cells in vitro. Our data suggest not only that the CCR4 molecule could be a suitable target for the novel antibody-based therapy for patients with ATLL but also that KM2760 may induce effective tumor immunity by reducing the number of regulatory T cells.
pRb2/p130 Decreases Sensitivity to Apoptosis Induced by Camptothecin and Doxorubicin but not by Taxol
Authors: Tonini Tiziana , Gabellini Chiara , Bagella Luigi , D’Andrilli Giuseppina , Masciullo Valeria , Romano Gaetano , Scambia Giovanni , Zupi Gabriella , Giordano Antonio
Published: September 2005

Purpose: In addition to their original function as cell cycle regulators, retinoblastoma (Rb) family members were recently reported to modulate the sensitivity of cancer cells to chemotherapeutic agents. The purpose of this study is to investigate the possible role of pRb2/p130 in the sensitivity of ovarian cancer to camptothecin, doxorubicin, and taxol.

Experimental Design: pRb2/p130 was overexpressed in the CAOV-3 ovarian cancer cell line, and the effect of pRb2/p130 overexpression on sensitivity to apoptosis trigged by IC50 doses of different drugs was evaluated by various methods, including 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, flow cytometry, and Western blot analyses.

Results: The results reported in this study support the conclusion that overexpression of pRb2/p130 in the CAOV-3 ovarian cancer cell line lacking wild-type p53 is able to inhibit apoptosis triggered by camptothecin and doxorubicin through the c-Jun NH2-terminal kinase signaling transduction pathway. Conversely, taxol-induced cell death is not influenced by the pRb2/p130 protein level.

Conclusions: A careful analysis of pRb2/p130 expression in tumor specimens could help to identify the best clinical protocol to be used for each patient, improving efficacy and tolerance and therefore offering additional progress in the treatment of advanced ovarian cancer.
Proteomic Analysis to Identify Breast Cancer Biomarkers in Nipple Aspirate Fluid
Authors: Alexander Hannah , Stegner Andrew L. , Wagner-Mann Colette , Du Bois Garrett C. , Alexander Stephen , Sauter Edward R.
Published: September 2005

Purpose: Proteomic analysis of breast nipple aspirate fluid (NAF) holds promise as a noninvasive method to identify markers of breast cancer. The objectives of the study were to: (a) describe the NAF proteome, (b) identify candidate markers of breast cancer in NAF by using proteomic analysis, and (c) validate the markers identified by using a quantitative, high-throughput ELISA analysis.

Experimental Design: For proteome analysis, NAF proteins from a single subject without breast cancer were separated by two-dimensional PAGE and were subjected to matrix-assisted laser desorption ionization time-of-flight mass spectometry identification. A total of 41 different proteins were identified, 25 of which were known to be secreted. To identify breast cancer markers, we separated 20 NAF samples (10 normal, 10 cancer) by two-dimensional PAGE. Three protein spots were detected that were up-regulated in three or more cancer samples. These spots were identified to be gross cystic disease fluid protein (GCDFP)-15, apolipoprotein D (apoD), and α1-acid glycoprotein (AAG). To validate these three potential biomarkers, 105 samples (53 from benign breasts and 52 from breasts with cancer) were analyzed using ELISA.

Results: Among all of the subjects, GCDFP-15 levels were lower (P < 0.001) and AAG levels were higher (P = 0.001) in breasts with cancer. This was also true in premenopausal (GCDFP-15, P = 0.011; AAG, P = 0.002) but not in postmenopausal women. GCDFP-15 levels were lowest (P = 0.003) and AAG levels highest (P < 0.001) in women with ductal carcinoma in situ (DCIS). Menopausal status influenced GCDFP-15 and AAG more in women without breast cancer than in women with breast cancer. apoD levels did not correlate significantly with breast cancer.

Conclusions: Our study revealed that the NAF proteome, as defined by two-dimensional PAGE, consists of a limited number of proteins, and that the expression of AAG and GCDFP-15 correlates with disease presence and stage.
Efficient Elimination of B-Lineage Lymphomas by Anti-CD20–Auristatin Conjugates
Authors: Law Che-Leung , Cerveny Charles G. , Gordon Kristine A. , Klussman Kerry , Mixan Bruce J. , Chace Dana F. , Meyer Damon L. , Doronina Svetlana O. , Siegall Clay B. , Francisco Joseph A. , Senter Peter D. , Wahl Alan F.
Published: September 2005

The anti-CD20 antibody rituximab is useful in the treatment of certain B-cell malignancies, most notably non-Hodgkin’s lymphoma. Its efficacy has been increased when used in combination with chemotherapy, yet anti-CD20 monoclonal antibodies (mAbs) directly conjugated with drugs such as doxorubicin (Dox) have failed to deliver drug or to demonstrate antitumor activity. We have produced anti-CD20 antibody-drug conjugates that possess potent antitumor activity by using the anti-mitotic agent, monomethyl auristatin E (MMAE), linked via the lysosomally cleavable dipeptide, valine-citrulline (vc). Two anti-CD20 conjugates, rituximab-vcMMAE and 1F5-vcMMAE, were selectively cytotoxic against CD20+ B-lymphoma cell lines, with IC50 values ranging from 50 ng/mL to 1 μg/mL. Unlike rituximab, which showed diffuse surface localization, rituximab-vcMMAE capped and was internalized within 4 hours after binding to CD20+ B cells. Internalization of rituximab-vcMMAE was followed by rapid G2-M phase arrest and onset of apoptosis. Anti-CD20 antibody-drug conjugates prepared with Dox were internalized and localized as with rituximab-vcMMAE, yet these were not effective for drug delivery (IC50 > 50 μg/mL). Consistent with in vitro activity, rituximab-vcMMAE showed antitumor efficacy in xenograft models of CD20-positive lymphoma at doses where rituximab or rituximab-Dox conjugates were ineffective. These data indicate that anti-CD20–based antibody-drug conjugates are effective antitumor agents when prepared with a stable, enzyme-cleavable peptide linkage to highly potent cytotoxic agents such as MMAE.
c-
erb
B-2 Related Aggressiveness in Breast Cancer Is Hypoxia Inducible Factor-1α Dependent
Authors: Giatromanolaki Alexandra , Koukourakis Michael I. , Simopoulos Costantinos , Polychronidis Alexandros , Gatter Kevin C. , Harris Adrian L. , Sivridis Efthimios
Published: September 2005

c-erbB-2–positive breast carcinomas are highly aggressive tumors. In vitro data on breast cell lines showed that c-erbB-2 enhanced translational efficiency of hypoxia inducible factor-1α (HIF1α) production (Laughner et al., Mol Cell Biol 2001;21:3995–4005). We investigated the clinical correlate of this observation to assess whether c-erbB-2 expression was related to HIF1α expression, angiogenesis, and prognosis. A series of 180 breast carcinomas of known c-erbB-2 status (90 c-erbB-2–positive and 90 c-erbB-2–negative carcinomas) were stained immunohistochemically for HIF1α and CD31 endothelial cell antigen. c-erbB-2 positivity was clearly related to HIF1α protein expression and high angiogenesis. However, prognosis was decreased only in cases with simultaneous c-erbB-2 and HIF1α expression. If activation of c-erbB-2 in humans results in overexpression of HIF1α independently of conditions of hypoxia, as occur in experimental studies, this interaction may represent a main pathway conferring clinical aggressiveness to c-erbB-2–positive breast tumors.
Human Autologous Tumor-Specific T-Cell Responses Induced by Liposomal Delivery of a Lymphoma Antigen
Authors: Neelapu Sattva S. , Baskar Sivasubramanian , Gause Barry L. , Kobrin Carol B. , Watson Thelma M. , Frye Andrea Robin , Pennington Robin , Harvey Linda , Jaffe Elaine S. , Robb Richard J. , Popescu Mircea C. , Kwak Larry W.
Published: September 2005

Purpose: The idiotype (Id) of the immunoglobulin on a given B-cell malignancy is a clonal marker that can serve as a tumor-specific antigen. We developed a novel vaccine formulation by incorporating Id protein with liposomal lymphokine that was more potent than a prototype, carrier-conjugated Id protein vaccine in preclinical studies. In the present study, we evaluated the safety and immunogenicity of this vaccine in follicular lymphoma patients.

Experimental Design: Ten patients with advanced-stage follicular lymphoma were treated with five doses of this second generation vaccine after chemotherapy-induced clinical remission. All patients were evaluated for cellular and humoral immune responses.

Results: Autologous tumor and Id-specific type I cytokine responses were induced by vaccination in 10 and 9 patients, respectively. Antitumor immune responses were mediated by both CD4+ and CD8+ T cells, were human lymphocyte antigen class I and II associated, and persisted 18 months beyond the completion of vaccination. Specific anti-Id antibody responses were detected in four patients. After a median follow-up of 50 months, 6 of the 10 patients remain in continuous first complete remission.

Conclusions: This first clinical report of a liposomal cancer vaccine demonstrates that liposomal delivery is safe, induces sustained tumor-specific CD4+ and CD8+ T-cell responses in lymphoma patients, and may serve as a model for vaccine development against other human cancers and infectious pathogens.
Genetic Polymorphisms of Human
Flavin Monooxygenase 3
in Sulindac-Mediated Primary Chemoprevention of Familial Adenomatous Polyposis
Authors: Hisamuddin Irfan M. , Wehbi Mohammad A. , Chao Ann , Wyre Hadley W. , Hylind Linda M. , Giardiello Francis M. , Yang Vincent W.
Published: September 2005

Purpose: Sulindac is a nonsteroidal anti-inflammatory drug (NSAID) effective in regressing adenomas in patients with familial adenomatous polyposis (FAP). However, a recent randomized trial showed that sulindac, when compared with placebo, failed to prevent the development of adenomatous polyps in genotypically positive but phenotypically negative FAP patients. The present study determined whether polymorphisms in the gene encoding flavin monooxygenase 3 (FMO3), a hepatic microsomal enzyme that inactivates sulindac, played a role in determining the efficacy of sulindac in preventing polyposis in this cohort of FAP patients.

Experimental Design: Genotyping was performed on seven established FMO3 polymorphisms previously shown to have functional relevance—M66I, P153L, E158K, V257M, E305X, E308G, and R492W—in 21 and 20 FAP patients, who received sulindac and placebo, respectively.

Results: None of the 41 patients exhibited heterozygous or homozygous M66I and R492W variant alleles, or homozygous P153L, V257M, and E305X variant alleles. Among sulindac-treated patients who did not develop adenomas (“responders”), 4 (33%) were homozygous for E158K and 2 (17%) were homozygous for E308G variant alleles. In contrast, none of the patients on sulindac who developed adenomas (“nonresponders”) exhibited homozygosity for either of the two variant alleles. In addition, polymorphisms in the E158K or E308G allele were associated with a significant reduction in mucosal prostanoid levels in patients treated with sulindac.

Conclusions: Polymorphisms in FMO3, particularly at the E158K and E308G loci, may reduce activity in catabolizing sulindac and result in an increased efficacy to prevent polyposis in FAP.
Evaluation of Combination Chemotherapy
Authors: Zhao Liang , Wientjes M. Guillaume , Au Jessie L-S.
Published: September 2005

Isobologram and combination index (CI) analyses are the two most popular methods for evaluating drug interactions in combination cancer chemotherapy. As the commonly used CI-based software program uses linear regression, our first objective was to evaluate the effects of logarithmic data transformation on data analysis and conclusions. Monte-Carlo simulations were conducted with experimentally relevant parameter values to generate error-containing effect or concentration-effect data of single agents and combinations. The simulated data were then analyzed with linear and nonlinear regression. The results showed that data transformation reduced the accuracy and precision of the regression-derived IC50, curve shape parameter and CI values. Furthermore, as neither isobologram nor CI analyses provide output of concentration-effect curves for investigator evaluation, our second objective was to develop a method and the associated computer program/algorithm to (a) normalize drug concentrations in IC50 equivalents and thereby enable simultaneous presentation of the curves for single agents and combinations in a single plot for visual inspection of potential curve shifts, (b) analyze concentration-effect data with nonlinear regression, and (c) use the curve shift analysis simultaneously with isobologram and CI analyses. The applicability of this method was shown with experimentally obtained data for single agent doxorubicin and suramin and their combinations in cultured tumor cells. In summary, this method, by incorporating nonlinear regression and curve shift analysis, although retaining the attractive features of isobologram and CI analyses, reduced the potential errors introduced by logarithmic data transformation, enabled visual inspection of data variability and goodness of fit of regression analysis, and simultaneously provided information on the extent of drug interaction at different combination ratios/concentrations and at different effect levels.
Phase I/II Randomized Trial Evaluating the Safety and Clinical Effects of Repifermin Administered to Reduce Mucositis in Patients Undergoing Autologous Hematopoietic Stem Cell Transplantation
Authors: Freytes Cesar O. , Ratanatharathorn Voravit , Taylor Charles , Abboud Camille , Chesser Nancy , Restrepo Alejandro , Arango Jorge , Odenheimer Daniel
Published: September 2005

Purpose: To evaluate the safety of repifermin (keratinocyte growth factor-2) administered before and after autologous hematopoietic stem cell transplantation (auto-HSCT). A preliminary analysis of the ability of keratinocyte growth factor-2 to prevent mucositis was also done.

Experimental Design: Forty-two patients received intravenous repifermin (25 μg/kg or 50 μg/kg) or placebo for 3 days before their auto-HSCT conditioning regimen and for up to 10 days after auto-HSCT. Within each dose level, 14 patients were randomized to repifermin and 7 patients to placebo. Clinical evaluations of mucositis were scheduled before auto-HSCT conditioning regimen, on the day of transplant, and three times per week until mucositis resolved.

Results: In general, the incidence of adverse events was similar for patients treated with repifermin and placebo. No clinically meaningful differences were noted among treatment groups for clinical laboratory variables. Treatment groups experienced similar time to engraftment. The frequency of Grade 2 to 4 mucositis was 100% for patients in the placebo group, 64% for patients in the 25 μg/kg group (P = 0.041 versus placebo), and 50% for patients in the 50 μg/kg group (P = 0.006 versus placebo). Results of other endpoints, including pain on swallowing and use of pain medication specifically for mucositis, suggested a better outcome for patients in the 50 μg/kg group compared with the placebo and 25 μg/kg groups.

Conclusions: Repifermin was well tolerated. Repifermin given before and after auto-HSCT seems to be active in reducing mucositis, but a larger trial will be necessary to determine the efficacy of repifermin with this dose schedule.
A Novel
Ex vivo
Model System for Evaluation of Conditionally Replicative Adenoviruses Therapeutic Efficacy and Toxicity
Authors: Kirby Tyler O. , Rivera Angel , Rein Daniel , Wang Minghui , Ulasov Ilya , Breidenbach Martina , Kataram Manjula , Contreras Juan L. , Krumdieck Carlos , Yamamoto Masato , Rots Marianne G. , Haisma Hidde J. , Alvarez Ronald D. , Mahasreshti Parameshwar J. , Curiel David T.
Published: September 2005

Purpose: Current animal tumor models are inadequate for the evaluation of toxicity and efficacy of conditionally replicative adenoviruses. A novel model system is needed that will provide insight into the anticipated therapeutic index of conditionally replicative adenoviruses preclinically. We endeavored to show a novel model system, which involves ex vivo evaluation of conditionally replicative adenovirus toxicity and therapeutic efficacy in thin, precision-cut slices of human primary tumor and liver.

Experimental Design: The Krumdieck thin-slice tissue culture system was used to obtain and culture slices of tumor xenografts of ovarian cancer cell lines, human primary ovarian tumors, and human liver. We determined the viability of slices in culture over a period of 36 to 48 hours by ([3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxphenyl-2-(4-sulfophenyl)-2H-tetrazolium, inner salt)]) (MTS) assay. In vitro Hey cells, slices of Hey xenografts, and human ovarian tumor or human liver slices were infected with 500vp/cell of either replication competent wild-type adenovirus (Ad5/3wt), conditionally replicative adenovirus (Ad5/3cox-2), or the replication deficient adenovirus (Ad5/3luc1). At 12-, 24-, and 36-hour intervals, the replication of adenoviruses in these slices was determined by quantitative reverse transcription-PCR of adenoviral E4 copy number.

Results: Primary tumor slices were able to maintain viability for up to 48 hours after infection with nonreplicative virus (Ad5luc1). Infection of Hey xenografts with Ad5/3cox-2 showed replication consistent with that seen in Hey cells infected in an in vitro setting. Primary tumor slices showed replication of both Ad5/3wt and Ad5/3cox over a 36-hour time period. Human liver slices showed replication of Ad5/3wt but a relative reduction in replication of Ad5/3cox-2 indicative of conditional replication “liver off” phenotype, thus predicting lower toxicity.

Conclusions: The thin-slice model system represents a stringent method of ex vivo evaluation of novel replicative adenoviral vectors and allows assessment of human liver replication relative to human tumor replication. This is the first study to incorporate this system for evaluation of therapeutic efficacy and replicative specificity of conditionally replicative adenoviruses. Also, the study is the first to provide a valid means for preclinical assay of potential conditionally replicative adenovirus-based hepatotoxicities, thus providing a powerful tool to determine therapeutic index for clinical translation of conditionally replicative adenoviruses.
Salivary Transcriptome Diagnostics for Oral Cancer Detection
Authors: Li Yang , St. John Maie A. R. , Zhou Xiaofeng , Kim Yong , Sinha Uttam , Jordan Richard C. K. , Eisele David , Abemayor Elliot , Elashoff David , Park No-Hee , Wong David T.
Published: September 2005

Purpose: Oral fluid (saliva) meets the demand for noninvasive, accessible, and highly efficient diagnostic medium. Recent discovery that a large panel of human RNA can be reliably detected in saliva gives rise to a novel clinical approach, salivary transcriptome diagnostics. The purpose of this study is to evaluate the diagnostic value of this new approach by using oral squamous cell carcinoma (OSCC) as the proof-of-principle disease.

Experimental Design: Unstimulated saliva was collected from patients (n = 32) with primary T1/T2 OSCC and normal subjects (n = 32) with matched age, gender, and smoking history. RNA isolation was done from the saliva supernatant, followed by two-round linear amplification with T7 RNA polymerase. Human Genome U133A microarrays were applied for profiling human salivary transcriptome. The different gene expression patterns were analyzed by combining a t test comparison and a fold-change analysis on 10 matched cancer patients and controls. Quantitative polymerase chain reaction (qPCR) was used to validate the selected genes that showed significant difference (P < 0.01) by microarray. The predictive power of these salivary mRNA biomarkers was analyzed by receiver operating characteristic curve and classification models.

Results: Microarray analysis showed there are 1,679 genes exhibited significantly different expression level in saliva between cancer patients and controls (P < 0.05). Seven cancer-related mRNA biomarkers that exhibited at least a 3.5-fold elevation in OSCC saliva (P < 0.01) were consistently validated by qPCR on saliva samples from OSCC patients (n = 32) and controls (n = 32). These potential salivary RNA biomarkers are transcripts of IL8, IL1B, DUSP1, HA3, OAZ1, S100P, and SAT. The combinations of these biomarkers yielded sensitivity (91%) and specificity (91%) in distinguishing OSCC from the controls.

Conclusions: The utility of salivary transcriptome diagnostics is successfully demonstrated in this study for oral cancer detection. This novel clinical approach could be exploited to a robust, high-throughput, and reproducible tool for early cancer detection. Salivary transcriptome profiling can be applied to evaluate its usefulness for other major disease applications as well as for normal health surveillance.
Mouse Homologue of a Novel Human Oncofetal Antigen, Glypican-3, Evokes T-Cell–Mediated Tumor Rejection without Autoimmune Reactions in Mice
Authors: Nakatsura Tetsuya , Komori Hiroyuki , Kubo Tatsuko , Yoshitake Yoshihiro , Senju Satoru , Katagiri Toyomasa , Furukawa Yoichi , Ogawa Michio , Nakamura Yusuke , Nishimura Yasuharu
Published: September 2005

Purpose and Experimental Design: We recently identified glypican-3 (GPC3) overexpressed specifically in human hepatocellular carcinoma, as based on cDNA microarray analysis of 23,040 genes, and we reported that GPC3 is a novel tumor marker for human hepatocellular carcinoma and melanoma. GPC3, expressed in almost all hepatocellular carcinomas and melanomas, but not in normal tissues except for placenta or fetal liver, is a candidate of ideal tumor antigen for immunotherapy. In this study, we attempted to identify a mouse GPC3 epitope for CTLs in BALB/c mice, and for this, we set up a preclinical study to investigate the usefulness of GPC3 as a target for cancer immunotherapy in vivo.

Results: We identified a mouse GPC3-derived and Kd- restricted CTL epitope peptide in BALB/c mice. Inoculation of this GPC3 peptide-specific CTL into s.c. Colon26 cancer cells transfected with mouse GPC3 gene (C26/GPC3) led to rejection of the tumor in vivo, and i.v. inoculation of these CTLs into sublethally irradiated mice markedly inhibited growth of an established s.c. tumor. Inoculation of bone marrow-derived dendritic cells pulsed with this peptide prevented the growth of s.c. and splenic C26/GPC3 accompanied with massive infiltration of CD8+ T cells into tumors. Evidence of autoimmune reactions was never observed in surviving mice that had rejected tumor cell challenges.

Conclusions: We found the novel oncofetal protein GPC3 to be highly immunogenic in mice and elicited effective antitumor immunity with no evidence of autoimmunity. GPC3 is useful not only for diagnosis of hepatocellular carcinoma and melanoma but also for possible immunotherapy or prevention of these tumors.
Intermittent Hypoxia Induces Proteasome-Dependent Down-Regulation of Estrogen Receptor α in Human Breast Carcinoma
Authors: Cooper Charlton , Liu Guang-Yu , Niu Yu-Lian , Santos Sylvia , Murphy Leigh C. , Watson Peter H.
Published: September 2005

Purpose: Hypoxia may influence gene expression to promote malignancy, and acute hypoxia has been shown to transiently repress estrogen receptor (ER)-α expression in breast cell lines. However, the effect of intermittent hypoxia, which is likely more prevalent in breast cancers, remains to be determined.

Experimental Design: ER-α expression was assessed by Western blot and immunohistochemistry in a selected cohort of 51 ER-α–positive breast carcinomas, in relation to markers of hypoxia. The effect of acute and intermittent hypoxia on ER-α expression was also determined in MCF7 and ZR-75 breast cell lines, together with the role of proteasome function with the proteasome inhibitor bortezomib.

Results: Regional loss of ER-α expression occurs in breast tumors and is consistently present in hypoxic regions defined by the proximity of necrosis and induction of hypoxia-induced genes carbonic anhydrase IX (CA-IX) and glucose transporter 1 (Glut-1), in both in situ (n = 29; P < 0.0001) and invasive (n = 20; P = 0.0001) carcinomas. In MCF7 and ZR-75 cells, ER-α is transiently down-regulated by acute hypoxia and rapidly restored by reoxygenation. However, intermittent, acute hypoxia can cause a similar down-regulation of ER-α that is not attributable to decreased mRNA and persists in MCF7 cells despite reoxygenation for up to 14 days. This effect occurs with no change in cell viability but a corresponding reduction in growth response to estradiol. However, ER-α expression can be restored by bortezomib.

Conclusions: Intermittent hypoxia can cause persistent changes in proteasome function that may contribute to reduced ER-α expression in breast tumors and consequently to diminished response and development of resistance to endocrine therapy.
Proteinase Activity in Human and Murine Saliva as a Biomarker for Proteinase Inhibitor Efficacy
Authors: Fingleton Barbara , Menon Ramkumar , Carter Kathy J. , Overstreet P. Dawn , Hachey David L. , Matrisian Lynn M. , McIntyre J. Oliver
Published: September 2005

As molecularly targeted agents reach the clinic, there is a need for assays to detect their presence and effectiveness against target molecules in vivo. Proteinase inhibitors are one example of a class of therapeutic agent for which satisfactory methods of identifying successful target modulation in vivo are lacking. This is of particular importance while these drugs are in clinical trials because standard maximum-tolerated dose-finding studies often are not suitable due to lack of toxicity. Saliva represents a readily accessible bodily fluid that can be repeatedly sampled and used for assaying in vivo effects of systemic drugs. Here we show the development of a simple assay that can be used to measure proteinase activity in saliva and proteinase inhibition after systemic treatment with three different proteinase inhibitors. A variety of gelatinolytic activities present in human and murine saliva have been assayed with a fluorescent dye-labeled substrate and assigned to different proteinase categories by inclusion of specific classes of inhibitors. Treatment of mice with either matrix metalloproteinase inhibitors or a urokinase inhibitor for a period as short as 48 hours results in levels of the drugs that can be detected in saliva by mass spectrometry and concomitant decreases in salivary proteinase activity, thus demonstrating that these inhibitors successfully modulate their targets in vivo.