bluuebunny/crossref_metadata_2025 huggingface dataset:
Surgical Removal of Primary Tumor Reverses Tumor-Induced Immunosuppression Despite the Presence of Metastatic Disease
Authors: Danna Erika A. , Sinha Pratima , Gilbert Mileka , Clements Virginia K. , Pulaski Beth A. , Ostrand-Rosenberg Suzanne
Published: September 2005

Immunotherapy is a promising approach for the management of malignancies. It may be particularly useful for tumors that do not respond to conventional therapies, such as many metastatic cancers. The efficacy of immunotherapy will depend on many factors, one of which is the immunocompetence of the host. Patients with large primary tumors frequently are immunosuppressed, making them poor candidates for immunotherapy. Although a few studies have reported that surgical removal of primary tumor reverses immunosuppression, it is not known whether metastatic disease in postsurgery patients inhibits this recovery. To determine the role of metastatic disease, we examined tumor-free mice versus mice with primary tumor and metastatic disease versus mice whose primary tumors were removed surgically but who had metastatic disease. We have used the mouse 4T1 mammary carcinoma, a BALB/c-derived transplantable tumor that shares many characteristics with human breast cancer and is an established model for spontaneous, metastatic cancer. Cell-mediated and humoral adaptive immunity, as measured by rejection of allogeneic tumor, antigen-specific T-cell proliferation, and antigen-specific antibody responses, was suppressed in 4T1-bearing nonsurgery mice relative to tumor-free mice. Surgical removal of primary tumor resulted in rebounding of antibody and cell-mediated responses, even in mice with metastatic disease. Macrophage activity, as measured by lipopolysaccharide responsiveness, and dendritic cell function, as measured by nominal and alloantigen presentation, were not suppressed in tumor-bearing mice. Therefore, the presence of primary tumor suppresses T-cell and antibody responses; however, surgical removal of primary tumor restores immunocompetence even when disseminated metastatic disease is present.
Endogenous Control of Cell Cycle Progression by Autocrine Transforming Growth Factor β in Breast Cancer Cells
Authors: Ammanamanchi Sudhakar , Tillekeratne Manoranjani P. M. , Ko Tien C. , Brattain Michael G.
Published: September 2005

Tumor progression due to loss of autocrine negative transforming growth factor-β (TGF-β) activity was reported in various cancers of epithelial origin. Estrogen receptor expressing (ER+) breast cancer cells are refractory to TGF-β effects and exhibit malignant behavior due to loss or inadequate expression of TGF-β receptor type II (RII). The exogenous TGF-β effects on the modulation of cell cycle machinery were analyzed previously. However, very little is known regarding the endogenous control of cell cycle progression by autocrine TGF-β. In this study, we have used a tetracycline regulatable RII cDNA expression vector to demonstrate that RII replacement reconstitutes autocrine negative TGF-β activity in ER+ breast cancer cells as evidenced by the delayed entry into S phase by the RII transfectants. Reversal of the delayed entry into S phase by the RII transfectants in the presence of tetracycline in addition to the decreased steady state transcription from a promoter containing the TGF-β responsive element (p3TP-Lux) by TGF-β neutralizing antibody treatment of the RII transfected cells confirmed that autocrine-negative TGF-β activity was induced in the transfectants. Histone H1 kinase assays indicated that the delayed entry of RII transfectants into phase was associated with markedly reduced cyclin-dependent kinase (CDK)2 kinase activity. This reduction in kinase activity was due to the induction of CDK inhibitors p21/waf1/cip1 and p27/kip, and their association with CDK2. Tetracycline treatment of RII transfectants led to the suppression of p21/waf1/cip1and p27/kip expression, thus, directly demonstrating induction of CDK inhibitors by autocrine TGF-β leading to growth control of ER+ breast cancer cells.
Increased Metastatic Dissemination in Human Melanoma Xenografts after Subcurative Radiation Treatment
Authors: Rofstad Einar K. , Mathiesen Berit , Galappathi Kanthi
Published: September 2005

Cancer patients showing local failure after radiation treatment have increased probability for developing metastatic disease. The mechanisms behind this observation have not been identified. In the present work, metastatic spread after inadequate radiation therapy was studied by using R-18 human melanoma xenografts as models of cancer in humans. Pimonidazole was used as a hypoxia marker, and hypoxia and urokinase-type plasminogen activator receptor (uPAR) expression were detected by immunohistochemistry. R-18 tumors regrowing after subcurative irradiation showed a higher frequency of lymph node metastasis than unirradiated tumors. The expression of uPAR was up-regulated in hypoxic tumor regions, and the fractions of hypoxic and uPAR-positive cells were ∼2-fold higher in regrowing irradiated tumors than in untreated tumors. Treatment with anti-uPAR antibody blocked metastasis almost completely in irradiated as well as unirradiated tumors. The metastatic frequency was higher in tumors regrowing after irradiation than in unirradiated tumors because the irradiation induced tumor hypoxia, and tumor hypoxia induced up-regulation of uPAR.
High-Resolution Magnetic Resonance Imaging of Disparities in the Transcapillary Transfer Rates in Orthotopically Inoculated Invasive Breast Tumors
Authors: Dadiani Maya , Margalit Raanan , Sela Noa , Degani Hadassa
Published: September 2005

In vivo mapping of the transcapillary fluxes in tumors can help predict the efficacy of delivery of blood-borne anticancer drugs. These fluxes are primarily affected by the vascular permeability and the pressure gradients across the blood vessels’ walls. We describe herein high-resolution dynamic contrast-enhanced magnetic resonance imaging of the influx and outflux transcapillary transfer rates in vivo in invasive MDA-MB-231 tumors orthotopically inoculated in severe combined immunodeficient mice. The tumors were noted for rapid growth, impaired drainage of fluid, and subsequent formation of cysts. Consequently, the time evolution of the contrast enhancement, induced by i.v. injection of Gadolinium diethylene-triamine-penta-acetate, exhibited two distinct patterns: transcapillary transfer in the cellular regions and simple diffusion in the cyst fluid. Both processes were analyzed at pixel resolution applying to each a physiological model and a corresponding algorithm. In the cellular region, the influx and outflux transcapillary transfer rates decreased during tumor growth; however, an increased disparity between the transfer constants was observed, with the outflux rate exceeding the influx rate. This quantitative spatial and temporal mapping of this disparity can provide a means to assess the physiological barriers to tracer delivery. It is hypothesized that both the increased disparity in transcapillary transfer rates and impaired fluid drainage in these tumors could arise from the development of interstitial hypertension.
Deficient Nucleotide Excision Repair Capacity Enhances Human Prostate Cancer Risk
Authors: Hu Jennifer J. , Hall M. Craig , Grossman Lawrence , Hedayati Mohammad , McCullough David L. , Lohman Kurt , Case L. Douglas
Published: September 2005

Prostate cancer (CaP) is the most commonly diagnosed non-skin cancer and the second leading cause of cancer death in American men. The etiology of CaP is not fully understood. Because most of the DNA adducts generated by some CaP-related carcinogens, including polycyclic aromatic hydrocarbons, heterocyclic amines, and pesticides, are removed by the nucleotide excision repair (NER) pathway, we pilot tested the hypothesis that CaP is associated with deficient NER capacity (NERC), measured by a plasmid-based host reactivation assay. Using cryopreserved lymphocytes collected in an ongoing, clinic-based case-control study, our results showed that the mean NERC was significantly lower (P = 0.03) in 140 cases (mean ± SD, 8.06 ± 5.17) than in 96 controls (9.64 ± 5.49). There was a significant association between below-median NERC and CaP risk: odds ratio (OR), 2.14; 95% confidence interval (CI), 1.19–3.86, after adjustment for age, race/ethnicity, smoking history, benign prostatic hyperplasia, and family history. This association was stronger in younger (<60 years of age) subjects (OR, 3.98; 95% CI, 1.13–14.02) compared with older (≥60) subjects (OR, 1.74; 95% CI, 0.90–3.37). When we stratified NERC values by quartiles of controls, there was a significant dose-dependent association between lower NERC and elevated CaP risk (p test for linear trend, 0.01). Compared with the highest quartile of NERC as the referent group, the adjusted ORs for the 75th, 50th, and 25th quartiles were: 1.09 (95% CI, 0.46–2.59); 1.81 (95% CI, 0.77–4.27); and 2.63 (95% CI, 1.17–5.95), respectively. This pilot study is the first direct evidence associating deficient NERC with human CaP risk.
Selenium Deficiency Abrogates Inflammation-Dependent Plasma Cell Tumors in Mice
Authors: Felix Klaus , Gerstmeier Simone , Kyriakopoulos Antonios , Howard O. M. Zack , Dong Hui-Fang , Eckhaus Michael , Behne Dietrich , Bornkamm Georg W. , Janz Siegfried
Published: September 2005

The role of the micronutrient, selenium, in human cancers associated with chronic inflammations and persistent infections is poorly understood. Peritoneal plasmacytomas (PCTs) in strain BALB/c (C), the premier experimental model of inflammation-dependent plasma cell transformation in mice, may afford an opportunity to gain additional insights into the significance of selenium in neoplastic development. Here, we report that selenium-depleted C mice (n = 32) maintained on a torula-based low-selenium diet (5–8 μg of selenium/kg) were totally refractory to pristane induction of PCT. In contrast, 11 of 26 (42.3%) control mice maintained on a selenium adequate torula diet (300 μg of selenium/kg) and 15 of 40 (37.5%) control mice fed standard Purina chow (440 μg of selenium/kg) developed PCT by 275 days postpristane. Abrogation of PCT was caused in part by the striking inhibition of the formation of the inflammatory tissue in which PCT develop (pristane granuloma). This was associated with the reduced responsiveness of selenium-deficient inflammatory cells (monocytes and neutrophils) to chemoattractants, such as thioredoxin and chemokines. Selenium-deficient C mice exhibited little evidence of disturbed redox homeostasis and increased mutant frequency of a transgenic lacZ reporter gene in vivo. These findings implicate selenium, via the selenoproteins, in the promotion of inflammation-induced PCT and suggest that small drug inhibitors of selenoproteins might be useful for preventing human cancers linked with chronic inflammations and persistent infections.
HIV-1 Protease Inhibitor, Ritonavir
Authors: Ikezoe Takayuki , Hisatake Yasuko , Takeuchi Tamotsu , Ohtsuki Yuji , Yang Yang , Said Jonathan W. , Taguchi Hirokuni , Koeffler H. Phillip
Published: September 2005

We previously showed that HIV-1 protease inhibitors (PIs) slowed the proliferation of human myeloid leukemia cells and enhanced their differentiation in the presence of all–trans-retinoic acid. In this study, we found that PIs, including ritonavir, saquinavir, and indinavir, inhibited the growth of DU145 and PC-3 androgen-independent prostate cancer cells as measured by a clonal proliferation assay. Recent studies showed that ritonavir inhibited cytochrome P450 3A4 enzyme (CYP3A4) in liver microsomes. The CYP3A4 is involved in drug metabolism and acquisition of drug resistance. To clarify the drug interaction between ritonavir and other anticancer drugs, we cultured DU145 cells with docetaxel either alone or in combination with ritonavir. Ritonavir enhanced the antiproliferative and proapoptotic effects of docetaxel in the hormonally independent DU145 prostate cancer cells in vitro as measured by the clonogenic soft agar assay and detection of the activated form of caspase-3 and cleavage of poly(ADP-ribose) polymerase using Western blot analysis. Real-time PCR showed that docetaxel induced the expression of CYP3A4 at the transcriptional level, and ritonavir (10−5 mol/L) completely blocked this induction. An ELISA-based assay also showed that ritonavir inhibited DNA binding activity of nuclear factor κB (NFκB) in DU145 cells, which is a contributor to drug resistance in cancer cells. Furthermore, combination treatment of docetaxel and ritonavir dramatically inhibited the growth of DU145 cells present as tumor xenografts in BNX nude mice compared with either drug alone. Importantly, docetaxel induced expression of CYP3A4 in DU145 xenografts, and ritonavir completely blocked this induction. Ritonavir also inhibited NFκB DNA binding activity in DU145 xenografts. Extensive histologic analyses of the liver, spleen, kidneys, bone marrow, skin, and subcutaneous fat pads from these mice showed no abnormalities. In summary, combination therapy of ritonavir and anticancer drugs holds promise for the treatment of individuals with advanced, drug resistant cancers.
A Small Interfering RNA Targeting Vascular Endothelial Growth Factor as Cancer Therapeutics
Authors: Takei Yoshifumi , Kadomatsu Kenji , Yuzawa Yukio , Matsuo Seiichi , Muramatsu Takashi
Published: September 2005

Vascular endothelial growth factor (VEGF) plays a critical role during normal embryonic angiogenesis and also in the pathological angiogenesis that occurs in a number of diseases, including cancer. We developed a novel VEGF blockade system using RNA interference. The small interfering RNA (siRNA) targeting human VEGF almost completely inhibited the secretion of VEGF in a human prostate cancer cell line, PC-3, whereas the control scramble siRNA showed no effects. The VEGF siRNA with atelocollagen dramatically suppressed tumor angiogenesis and tumor growth in a PC-3 s.c. xenograft model. Atelocollagen provided a beneficial delivering means by which stabilization and efficient transfection of the siRNA injected into the tumors were achieved.
Polyclonal Development of Mouse Mammary Preneoplastic Nodules
Authors: Kisseberth William C. , Sandgren Eric P.
Published: September 2005

Studies of cellular interactions are critical to the understanding of tumorigenesis. Although many studies have demonstrated a monoclonal composition of advanced neoplasms in humans and mice, the clonal composition of smaller, antecedent lesions has been studied less thoroughly. To examine the clonal development of breast cancer, we generated chimeric mammary glands using mouse mammary epithelium with an inherited predisposition for neoplasia. Analysis of whey acidic protein-transforming growth factor-α transgenic mouse mammary glands, chimeric for two different cell lineage markers, revealed that mammary ducts and alveoli are polyclonal, and putative early preneoplastic lesions, hyperplastic alveolar nodules (HANs), frequently are polyclonal. Furthermore, the chimeric patch patterns in individual HANs were similar to the patterns observed in pregnant chimeric mammary glands. Thus, polyclonality in HANs appears to reflect persistence of the polyclonal architecture of ducts and/or alveoli, suggesting that hyperplasia formation can be the result of non-cell autonomous local tissue microenvironmental influences on groups of cells, rather than clonal progression of a single initiated cell.
A Genome-Wide Screen in
Saccharomyces cerevisiae
Reveals Altered Transport As a Mechanism of Resistance to the Anticancer Drug Bleomycin
Authors: Aouida Mustapha , Pagé Nicolas , Leduc Anick , Peter Matthias , Ramotar Dindial
Published: September 2005

The potent DNA damaging agent bleomycin (BLM) is highly effective for treating various cancers, although, in certain individuals, the development of cellular resistance to the drug can severely diminish its antineoplastic properties. We performed two independent genome-wide screens using a Saccharomyces cerevisiae mutant collection to isolate variants exhibiting either sensitivity or resistance to BLM. This procedure reproducibly identified a relatively large collection of 231 BLM-hypersensitive mutants, representing genes belonging to diverse functional groups. In contrast, only five BLM-resistant mutants could be recovered by our screens. Among these latter mutants, three were deleted for genes involved in plasma membrane transport, including the l-carnitine transporter Agp2, as well as the kinases Ptk2 and Sky1, which are involved in regulating polyamine transport. We further showed that Agp2 acts as a transporter of BLM and that overexpression of this transporter significantly enhances BLM-induced cell killing. Our data strongly implicate membrane transport as a key determinant in BLM resistance in yeast. This finding is critical, given that very little is known about BLM transport in human cells. Indeed, characterization of analogous mechanisms in humans may ultimately lead to enhancement of the antitumor properties of BLM.
Mapping Tumor Epitope Space by Direct Selection of Single-Chain Fv Antibody Libraries on Prostate Cancer Cells
Authors: Liu Bin , Conrad Fraser , Cooperberg Matthew R. , Kirpotin Dmitri B. , Marks James D.
Published: September 2005

The identification of tumor-specific cell surface antigens is a critical step toward the development of targeted therapeutics for cancer. The epitope space at the tumor cell surface is highly complex, composed of proteins, carbohydrates, and other membrane-associated determinants including post-translational modification products, which are difficult to probe by approaches based on gene expression. This epitope space can be efficiently mapped by complementary monoclonal antibodies. By selecting human antibody gene diversity libraries directly on the surface of prostate cancer cells, we have taken a functional approach to identifying fully human, tumor-specific monoclonal antibodies without prior knowledge of their target antigens. Selection conditions have been optimized to favor tumor-specific antibody binding and internalization. To date, we have discovered >90 monoclonal antibodies that specifically bind and enter prostate cancer cells, with little or no binding to control cells. These antibodies are able to efficiently deliver intracellular payloads when attached to nanoparticles such as liposomes. In addition, a subset of the antibodies displayed intrinsic antiproliferative activity. These tumor-specific internalizing antibodies are likely to be useful for targeted therapeutics either alone or in combination with effector molecules. The antigens they bind constitute a tumor-specific internalizing epitope space that is likely to play a significant role in cancer cell homeostasis. Targeting components of this epitope space may facilitate development of immunotherapeutic and small molecule-based strategies as well as the use of other therapeutic agents that rely upon delivery to the interior of the tumor cell.
Activator Protein 2α Inhibits Tumorigenicity and Represses Vascular Endothelial Growth Factor Transcription in Prostate Cancer Cells
Authors: Ruiz Maribelis , Pettaway Curtis , Song Renduo , Stoeltzing Oliver , Ellis Lee , Bar-Eli Menashe
Published: September 2005

Activator protein-2α (AP-2) is a transcription factor that regulates proliferation and differentiation in mammalian cells. We have shown previously that although AP-2 is expressed highly in normal prostatic epithelium, its expression is lost in high-grade prostatic intraepithelial neoplasia and prostate cancer, suggesting that loss of AP-2 plays a role in prostate cancer development. We demonstrate that forced AP-2 expression in the prostate cancer cell line LNCaP-LN3 (AP-2 negative) inhibited dramatically tumor incidence in nude mice. To identify the genes that might have been responsible for this effect, we used microchip expression array. We found several genes known to be involved in malignancy were deregulated, including the vascular endothelial growth factor (VEGF) gene. Because VEGF was down-regulated by 14.7-fold in the AP-2-transfected cells and because it is a major angiogenic factor in prostate cancer development and progression, we chose to examine the AP-2-VEGF interaction. Our evidence suggests that AP-2 repressed transcriptionally the VEGF promoter by competing with the transcriptional activator Sp3. Loss of AP-2 in prostate cancer cells reduced the AP-2:Sp3 ratio and activated VEGF expression. AP-2 acts as a tumor-suppressor gene in prostate cancer. Elucidating the molecular events resulting from loss of AP-2 in the prostate epithelium has implications for the understanding and prevention of the onset of prostate cancer.
Large-Scale Allelotype of Pancreaticobiliary Carcinoma Provides Quantitative Estimates of Genome-Wide Allelic Loss
Authors: Iacobuzio-Donahue Christine A. , van der Heijden Michiel S. , Baumgartner Mark R. , Troup William J. , Romm Jane M. , Doheny Kimberly , Pugh Elizabeth , Yeo Charles J. , Goggins Michael G. , Hruban Ralph H. , Kern Scott E.
Published: September 2005

Studies of the allelotype of human cancers have provided valuable insights into those chromosomes targeted for genetic inactivation during tumorigenesis. We present the comprehensive allelotype of 82 xenografted pancreatic or biliary cancers using 386 microsatellite markers and spanning the entire genome at an average coverage of 10 cM. Allelic losses were nonrandomly distributed across the genome and most prevalent for chromosome arms 9p, 17p, and 18q (>60%), sites of the known tumor suppressor genes CDKN2A, TP53, and MADH4. Moderate rates of loss (at any one locus) were noted for chromosome arms 3p, 6q, 8p, 17q, 18p, 21q, and 22q (40–60%). A mapping of individual loci of allelic loss revealed 11 “hot spots” of loss of heterozygosity (>30%) in addition to loci near known tumor suppressor genes, corresponding to 3p, 4q, 5q, 6q, 8p, 12q, 14q, 21q, 22q, and the X chromosome. The average genomic fractional allelic loss was 15.3% of all tested markers for the 82 xenografted cancers, with allelic loss affecting as little as 1.5% to as much as 32.1% of tested loci, a remarkable 20-fold range. We determined the chromosome location (in cM) of each of the 386 markers used based on mapping data available from the National Center for Biotechnology Information, and we provide the first distance-based estimates of chromosome material lost in a human epithelial cancer. Specifically, we found that the cumulative size of allelic losses ranged from 58 to 1160 cM, with an average loss of 561.32 cM/tumor. We compared the genomic fractional allelic loss of each xenografted cancer with known clinicopathological features for each patient and found a significant correlation with smoking status (P < 0.01). These findings offer new loci for investigation of the genetic alterations common to pancreaticobiliary cancers and aid the understanding of mechanisms of allelic loss in human carcinogenesis.
A Retinoid-Related Molecule that Does Not Bind to Classical Retinoid Receptors Potently Induces Apoptosis in Human Prostate Cancer Cells through Rapid Caspase Activation
Authors: Keedwell Richard G. , Zhao Yi , Hammond Lisette A. , Qin Suofu , Tsang Kwok-Yin , Reitmair Armin , Molina Yanira , Okawa Yumiko , Atangan Larissa I. , Shurland Dixie-Lee , Wen Kaisheng , Wallace D. Michael A. , Bird Roger , Chandraratna Roshantha A. S , Brown Geoffrey
Published: September 2005

Synthetic retinoid-related molecules, such as N-(4-hydroxyphenyl)retinamide (fenretinide) and 6-[3-(1-adamantyl)-4-hydroxyphenyl]-2-naphthalene carboxylic acid (CD437) induce apoptosis in a variety of malignant cells. The mechanism(s) of action of these compounds does not appear to involve retinoic acid receptors (RARs) and retinoid X receptors (RXRs), although some investigators disagree with this view. To clarify whether some retinoid-related molecules can induce apoptosis without involving RARs and/or RXRs, we used 4-[3-(1-heptyl-4,4-dimethyl-2-oxo-1,2,3,4-tetrahydroquinolin-6-yl)-3-oxo-E-propenyl] benzoic acid (AGN193198) that neither binds effectively to RARs and RXRs nor transactivates in RAR- and RXR-mediated reporter assays. AGN193198 potently induced apoptosis in prostate, breast, and gastrointestinal carcinoma cells and in leukemia cells. AGN193198 also abolished growth (by 50% at 130–332 nm) and induced apoptosis in primary cultures established from prostatic carcinoma (13 patients) and gastrointestinal carcinoma (1 patient). Apoptosis was induced rapidly, as indicated by mitochondrial depolarization and DNA fragmentation. Molecular events provoked by AGN193198 included activation of caspase-3, -8, -9, and -10 (by 4–6 h) and the production of BID/p15 (by 6 h). These findings show that caspase-mediated induction of apoptosis by AGN193198 is RAR/RXR-independent and suggest that this compound may be useful in the treatment of prostate cancer.
Estrogen Enhances Angiogenesis through a Pathway Involving Platelet-Activating Factor-Mediated Nuclear Factor-κB Activation
Authors: Seo Kook Heon , Lee Hyun-Suk , Jung Bongnam , Ko Hyun-Mi , Choi Jung-Hwa , Park Sung Jun , Choi Il-Hwan , Lee Hern-Ku , Im Suhn-Young
Published: September 2005

In this study, we investigated the molecular events involved in estrogen-induced angiogenesis. Treatment of the human endometrial adenocarcinoma cells, HEC-1A, with estrogen up-regulated mRNA expression and protein synthesis of various angiogenic factors such as tumor necrosis factor-α, interleukin-1, basic fibroblast growth factor, and vascular endothelial growth factor. The estrogen-dependent induction of the expression was blocked by the platelet-activating factor (PAF) antagonists, WEB 2170. Estrogen treatment caused the activation of nuclear factor (NF)-κB in HEC-1A cells and was also blocked by PAF antagonist. Inhibitors of NF-κB activation inhibited estrogen-induced mRNA expression and protein synthesis of the angiogenic factors. Estrogen led to a pronounced angiogenesis as assessed by a mouse Matrigel model in vivo and endothelial cell sprouting in vitro. PAF antagonists or NF-κB inhibitors significantly inhibited this estrogen-dependent angiogenesis. Estrogen caused phospholipase A2 (PLA2) gene and protein expression. Estrogen-induced vascular endothelial growth factor mRNA expression and sprouting were significantly inhibited by PLA2 inhibitors, suggesting PLA2 expression is the upstream pathway in the estrogen-induced angiogenesis. Taken together, these results suggest that estrogen induces the production of angiogenic factors via a mechanism involving PAF-mediated NF-κB activation.
Donor Cell Cycling, Trafficking, and Accumulation during Adoptive Immunotherapy for Murine Lung Metastases
Authors: Skitzki Joseph , Craig Ronald A. , Okuyama Ryugi , Knibbs Randall N. , McDonagh Kevin , Chang Alfred E. , Stoolman Lloyd M.
Published: September 2005

Adoptive cellular immunotherapy treats metastatic cancer by infusing cultured T cells derived from resected tumors or primed lymph nodes. The infused cells must accumulate in metastatic lesions to suppress growth; however, this process and the resulting clinical response are dynamic and evolve during the days and weeks following cell infusion. This study used novel experimental techniques to determine the fate of infused, cultured tumor-draining lymph node (TDLN) cells during the treatment of murine pulmonary micrometastases. After infusion, the cultured TDLN cells accumulated in the pulmonary vasculature, systemic lymph nodes, and spleen. Donor cells were initially confined to alveolar capillaries with no movement into metastases. Within 4 h, TDLN cells began migrating across pulmonary postcapillary venules and first appeared within metastases. After 24 h, most donor cells in the lung were associated with tumor nodules. Donor cell proliferation within the lung and lymphoid organs was detected within 24 h of infusion and continued throughout the 5-day period of observation. Furthermore, those proliferating in lymphoid organs trafficked back to the tumor-bearing lungs, accounting for ∼50% of the donor cells recovered from these sites after 5 days. Finally, donor T cells entering metastases both early (within 1–2 days) and late (after 2 days) suppressed tumor growth, but the early recruits accounted for most of the therapeutic response. Thus, cultured TDLN cells migrate directly into tumor-bearing organs and seed the recirculating pool of lymphocytes after infusion. Small fractions of the later differentiate in lymphoid organs and migrate into the lungs but appear less effective than effector cells in the initial bolus.
Spontaneous Vitiligo in an Animal Model for Human Melanoma
Authors: Lengagne Renée , Le Gal Frédérique-Anne , Garcette Marylène , Fiette Laurence , Ave Patrick , Kato Masashi , Briand Jean-Paul , Massot Christian , Nakashima Izumi , Rénia Laurent , Guillet Jean-Gérard , Prévost-Blondel Armelle
Published: September 2005

Tumor antigen-reactive T cells can be detected in a large proportion of melanoma patients, but their efficacy on tumor control in vivo remains unclear. On the other hand, vitiligo, a skin disorder characterized by patchy depigmented macules, may occur spontaneously or after antitumor therapies. Moreover, vitiligo is significantly associated with positive clinical response, but the mechanism is not understood. Therefore, the establishment of a relevant animal model in which melanoma and vitiligo spontaneously develop stepwise may be useful for better understanding of the parameters involved in the destruction of both benign and malignant melanocytes. In a previous work, we established a mouse model for melanoma in which MT/ret transgenic mice express the ret oncogene fused to the metallothionein promoter. Here we report that melanoma leads to spontaneous vitiligo. We further investigate, for the first time in this model, the natural antitumor T-cell response and evaluate the role of cellular immunity in the development of the disease. Interestingly, the occurrence of spontaneous tumor nodules in MT/ret mice with melanoma-associated vitiligo is significantly delayed when compared in melanoma mice without vitiligo. Moreover, a significant proportion of mice with melanoma-associated vitiligo resisted a challenge with syngeneic melanoma cells in contrast to animals without vitiligo. Our results confirm that vitiligo is associated with clinical benefit and further demonstrate the crucial role of CD8+ T cells for tumor control in melanoma-associated vitiligo.
Loss of Cables, a Cyclin-Dependent Kinase Regulatory Protein, Is Associated with the Development of Endometrial Hyperplasia and Endometrial Cancer
Authors: Zukerberg Lawrence R. , DeBernardo Robert L. , Kirley Sandra D. , D’Apuzzo Massimo , Lynch Maureen P. , Littell Ramey D. , Duska Linda R. , Boring Landin , Rueda Bo R.
Published: September 2005

Endometrial cancer is the most common gynecological cancer in Western industrialized countries. Cables, a cyclin-dependent kinase binding protein, plays a role in proliferation and/or differentiation. Cables mutant mice are viable, but develop endometrial hyperplasia and carcinoma in situ at a young age. Exposure to chronic low levels of estrogen results in development of endometrial cancer, similar to that observed in the postmenopausal female. In vitro and in vivo studies demonstrate that levels of Cables mRNA in benign human endometrial epithelium are up-regulated by progesterone and down-regulated by estrogen. Furthermore, nuclear immunostaining for Cables is lost in a high percentage of cases of human endometrial hyperplasia and adenocarcinoma, which are likely the product of unopposed estrogen. The loss of Cables immunostaining in the human endometrial cancer samples correlates with a marked decrease in Cables mRNA. Ectopic expression of Cables in human endometrial cells dramatically slows cell proliferation. Collectively, these data provide evidence that Cables is hormonally regulated and is involved in regulating endometrial cell proliferation. In addition, loss or suppression of Cables may be an early step in the development of endometrial cancer.
Insulin-like Growth Factor (IGF)-binding Protein-4 Inhibits Colony Formation of Colorectal Cancer Cells by IGF-independent Mechanisms
Authors: Diehl Daniela , Hoeflich Andreas , Wolf Eckhard , Lahm Harald
Published: September 2005

Effects of insulin-like growth factor-binding protein-4 (IGFBP-4) on proliferation, colony formation, and cell migration were assessed in IGF-sensitive and -insensitive colorectal cancer cell lines. In IGF-insensitive Isreco-1 cells, overexpression of IGFBP-4 reduced colony formation but not cell proliferation and migration, whereas exogenous IGF-II had no effect. In IGF-dependent LS1034 cells, IGFBP-4 inhibited all parameters of growth tested, whereas IGF-II partially restored reduced proliferation and cell migration only. In Isreco-2 cells, which lack endogenous IGF expression but are IGF sensitive, colony formation was also reduced by IGFBP-4. Therefore, specific parameters of malignant progression of colon carcinoma cells are distinctly affected by IGF-dependent and IGF-independent effects of IGFBP-4.
Inhibitory Effect of 12-
O
-Tetradecanoylphorbol-13-acetate Alone or in Combination with All-
trans
-Retinoic Acid on the Growth of LNCaP Prostate Tumors in Immunodeficient Mice
Authors: Zheng Xi , Chang Richard L. , Cui Xiao-Xing , Avila Gina E. , Lee Sabrina , Lu Yao Ping , Lou You Rong , Shih Weichung Joe , Lin Yong , Reuhl Kenneth , Newmark Harold , Rabson Arnold , Conney Allan H.
Published: September 2005

Clinically achievable concentrations of 12-O-tetradecanoylphorbol-13-acetate (TPA; 0.16–0.32 nm) and all-trans-retinoic acid (ATRA; 0.5–1 μm) had a synergistic inhibitory effect on the growth of cultured LNCaP prostate cancer cells, and apoptosis was markedly stimulated. In additional studies, NCr immunodeficient mice received s.c. injection with LNCaP cells in Matrigel. After 4–6 weeks, mice with well-established tumors received i.p. injection with vehicle, TPA (0.16 nmol/g body weight), ATRA (0.5 nmol/g body weight), or TPA+ATRA in vehicle once a day for 46 days. Tumor growth occurred in all of the vehicle-treated control mice. The percentage of animals with some tumor regression after 21 days of treatment was 0% for the control group, 31% for the ATRA group, 62% for the TPA group, and 100% for the TPA+ATRA group (13 mice/group). Although treatment of the mice with TPA or TPA+ATRA continued to inhibit tumor growth for the duration of the 46-day study, treatment of the mice with ATRA alone did not inhibit tumor growth beyond 28 days of daily injections (6 mice/group). Mechanistic studies indicated that treatment of the mice with TPA or TPA+ATRA for 46 days increased apoptosis in the tumors, and treatment with TPA+ATRA also decreased the mitotic index. Because the dose of TPA used in this study was effective and resulted in clinically achievable blood levels, clinical trials with TPA alone or in combination with ATRA in patients with prostate cancer may be warranted.
Cullin 3 Promotes Proteasomal Degradation of the Topoisomerase I-DNA Covalent Complex
Authors: Zhang Hua-Feng , Tomida Akihiro , Koshimizu Ritsuko , Ogiso Yasunari , Lei Shuhong , Tsuruo Takashi
Published: September 2005

DNA topoisomerase I (TOP1)-DNA covalent complexes are the initial lesions produced by antitumor camptothecins (CPTs). The TOP1-directed drugs stimulate degradation of TOP1 via the ubiquitin-proteasome pathway. We found that proteasome inhibition prevents degradation of DNA-bound TOP1 and sustains high levels of covalent complexes, thus enhancing CPT-induced cell death. Consistent with this, increased degradation of TOP1-DNA covalent complexes was seen in acquired CPT-resistant cells. We found that the resistant cells showed elevated expressions of Cul3, a member of the cullin family of E3 ubiquitin ligases. The reduction in Cul3 expression by small interfering RNA decreased degradation of TOP1-DNA covalent complexes. Conversely, Cul3 overexpression by stable transfection promoted covalent complex degradation and reduced CPT-induced cell death without affecting basal TOP1 expression levels. These results indicate that Cul3, by promoting proteasomal degradation of TOP1-DNA covalent complexes, becomes an important regulator for cellular CPT sensitivity.
Antitumor Activity of HKI-272, an Orally Active, Irreversible Inhibitor of the HER-2 Tyrosine Kinase
Authors: Rabindran Sridhar K. , Discafani Carolyn M. , Rosfjord Edward C. , Baxter Michelle , Floyd M. Brawner , Golas Jonathan , Hallett William A. , Johnson Bernard D. , Nilakantan Ramaswamy , Overbeek Elsebe , Reich Marvin F. , Shen Ru , Shi Xiaoqing , Tsou Hwei-Ru , Wang Yu-Fen , Wissner Allan
Published: September 2005

HER-2 belongs to the ErbB family of receptor tyrosine kinases, which has been implicated in a variety of cancers. Overexpression of HER-2 is seen in 25–30% of breast cancer patients and predicts a poor outcome in patients with primary disease. Trastuzumab (Herceptin), a monoclonal antibody to HER-2, is specifically approved for HER-2-positive breast cancer but is active only in a subset of these tumors. Blocking HER-2 function by a small molecule kinase inhibitor, therefore, represents an attractive alternate strategy to inhibit the growth of HER-2-positive tumors. HKI-272 is a potent inhibitor of HER-2 and is highly active against HER-2-overexpressing human breast cancer cell lines in vitro. It also inhibits the epidermal growth factor receptor (EGFR) kinase and the proliferation of EGFR-dependent cells. HKI-272 reduces HER-2 receptor autophosphorylation in cells at doses consistent with inhibition of cell proliferation and functions as an irreversible binding inhibitor, most likely by targeting a cysteine residue in the ATP-binding pocket of the receptor. In agreement with the predicted effects of HER-2 inactivation, HKI-272 treatment of cells results in inhibition of downstream signal transduction events and cell cycle regulatory pathways. This leads to arrest at the G1-S (Gap 1/DNA synthesis)-phase transition of the cell division cycle, ultimately resulting in decreased cell proliferation. In vivo, HKI-272 is active in HER-2- and EGFR-dependent tumor xenograft models when dosed orally on a once daily schedule. On the basis of its favorable preclinical pharmacological profile, HKI-272 has been selected as a candidate for additional development as an antitumor agent in breast and other HER-2-dependent cancers.
A Novel Orally Bioavailable Inhibitor of Kinase Insert Domain-Containing Receptor Induces Antiangiogenic Effects and Prevents Tumor Growth
in Vivo
Authors: Sepp-Lorenzino Laura , Rands Elaine , Mao Xianzhi , Connolly Brett , Shipman Jennifer , Antanavage Joanne , Hill Susan , Davis Lenora , Beck Stephen , Rickert Keith , Coll Kathleen , Ciecko Patrice , Fraley Mark , Hoffman William , Hartman George , Heimbrook David , Gibbs Jackson , Kohl Nancy , Thomas Kenneth
Published: September 2005

A strategy for antagonizing vascular endothelial growth factor (VEGF) -induced angiogenesis is to inhibit the kinase activity of its receptor, kinase insert domain-containing receptor (KDR), the first committed and perhaps the last unique step in the VEGF signaling cascade. We synthesized a novel ATP-competitive KDR tyrosine kinase inhibitor that potently suppresses human and mouse KDR activity in enzyme (IC50 = 7.8–19.5 nm) and cell-based assays (IC50 = 8 nm). The compound was bioavailable in vivo, leading to a dose-dependent decrease in basal- and VEGF-stimulated KDR tyrosine phosphorylation in lungs from naïve and tumor-bearing mice (IC50 = 23 nm). Pharmacokinetics and pharmacodynamics guided drug dose selection for antitumor efficacy studies. HT1080 nude mice xenografts were treated orally twice daily with vehicle, or 33 or 133 mg/kg of compound. These doses afforded trough plasma concentrations approximately equal to the IC50 for inhibition of KDR autophosphorylation in vivo for the 33 mg/kg group, and higher than the IC99 for the 133 mg/kg group. Chronic treatment at these doses was well-tolerated and resulted in dose-dependent inhibition of tumor growth, decreased tumor vascularization, decreased proliferation, and enhanced cell death. Antitumor efficacy correlated with inhibition of KDR tyrosine phosphorylation in the tumor, as well as in a surrogate tissue (lung). Pharmacokinetics and pharmacodynamics assessment indicated that the degree of tumor growth inhibition correlated directly with the extent of inhibition of KDR tyrosine phosphorylation in tumor or lung at trough. These observations highlight the need to design antiangiogenic drug regimens to ensure constant target suppression and to take advantage of PD end points to guide dose selection.
Genetics and Cytogenetics of Multiple Myeloma
Authors: Fonseca Rafael , Barlogie Bart , Bataille Regis , Bastard Christian , Bergsagel P. Leif , Chesi Marta , Davies Faith E. , Drach Johannes , Greipp Philip R. , Kirsch Ilan R. , Kuehl W. Michael , Hernandez Jesus M. , Minvielle Stephane , Pilarski Linda M. , Shaughnessy John D. , Stewart A. Keith , Avet-Loiseau Herve
Published: September 2005

Much has been learned regarding the biology and clinical implications of genetic abnormalities in multiple myeloma. Because of recent advances in the field, an International Workshop was held in Paris in February of 2003. This summary describes the consensus recommendations arising from that meeting with special emphasis on novel genetic observations. For instance, it is increasingly clear that translocations involving the immunoglobulin heavy-chain locus are important for the pathogenesis of one-half of patients. As a corollary, it also clear that the remaining patients, lacking IgH translocations, have hyperdiploidy as the hallmark of their disease. Several important genetic markers are associated with a shortened survival such as chromosome 13 monosomy, hypodiploidy, and others. The events leading the transformation of the monoclonal gammopathy of undetermined significance (MGUS) to myeloma are still unclear. One of the few differential genetic lesions between myeloma and MGUS is the presence of ras mutations in the latter. Gene expression platforms are capable of detecting many of the genetic aberrations found in the clonal cells of myeloma. Areas in need of further study were identified. The study of the genetic aberrations will likely form the platform for targeted therapy for the disease.
Mismatch Repair Gene
PMS2
Authors: Nakagawa Hidewaki , Lockman Janet C. , Frankel Wendy L. , Hampel Heather , Steenblock Kelle , Burgart Lawrence J. , Thibodeau Stephen N. , de la Chapelle Albert
Published: September 2005

The MutLα heterodimer formed by mismatch repair (MMR) proteins MLH1 and PMS2 is a major component of the MMR complex, yet mutations in the PMS2 gene are rare in the etiology of hereditary nonpolyposis colorectal cancer. Evidence from five published cases suggested that contrary to the Knudson principle, PMS2 mutations cause hereditary nonpolyposis colorectal cancer or Turcot syndrome only when they are biallelic in the germline or abnormally expressed. As candidates for PMS2 mutations, we selected seven patients whose colon tumors stained negative for PMS2 and positive for MLH1 by immunohistochemistry. After conversion to haploidy, truncating germline mutations of PMS2 were found in two patients (2192delTAACT and deletion of exon 8). These mutations abrogated PMS2 protein in germline cells by Western analysis. In two additional patients, PMS2 protein from one allele also was abrogated. Novel or previously described missense variants of PMS2 were detected, but their pathogenicity is undetermined. We detected and characterized a new transcript, PMS2CL, showing 98% sequence identity with exons 9 and 11–15 of PMS2 and emanating from a locus close to PMS2 in chromosome 7p. Its predicted protein product was not detected. Thus, in addition to several previously described PMS2-related genes resembling the 5′ end of PMS2, at least one related gene resembles the 3′ end of PMS2. In conclusion, both detectable and presently undefined germline mutations are deleterious and produce susceptibility to cancer by the two-hit mechanism. Paralogous genes interfere with mutation detection, resulting in underdiagnosis of PMS2 mutations. Mutation detection in PMS2 requires haploid DNA.
Chromatin Assembly Factor-1, a Marker of Clinical Value to Distinguish Quiescent from Proliferating Cells
Authors: Polo Sophie E. , Theocharis Stamatios E. , Klijanienko Jerzy , Savignoni Alexia , Asselain Bernard , Vielh Philippe , Almouzni Geneviève
Published: September 2005

Histone synthesis and chromatin assembly are mainly associated with DNA replication and are thus intimately involved in cell cycle regulation. The expression of key components involved in these events in human cells was studied in relation to cell-proliferative status. Among several chromatin assembly factors, chromatin assembly factor (CAF)-1 stood out as the most discriminating marker of the proliferative state. We show, using both immunofluorescence and Western blot analysis, that the expression of both CAF-1 large subunits, p150 and p60, is massively down-regulated during quiescence in several cell lines. Upon exit from the quiescent state, the CAF-1 subunits are re-expressed early, before DNA replication. The amounts of either total or chromatin-associated pools of CAF-1 proteins correlate directly with cell proliferation. Regulation of CAF-1 expression is partly controlled at the RNA level, as shown by quantitative reverse transcription-PCR and Northern blot experiments. Biological material from benign and malignant human breast tumors analyzed by immunocytochemistry and immunohistochemistry exhibits a strong positive correlation between CAF-1 p60 expression and the following proliferation markers: S-phase fraction (r = 0.84, P < 0.0001); Ki-67 (r = 0.94, P < 0.0001); and proliferating cell nuclear antigen (r = 0.95, P = 0.0001). We discuss the advantages of using CAF-1 to assess cell proliferation. High CAF-1 p60 levels are also shown to be associated with various prognostic factors. Our data highlight the precise association of CAF-1 expression with the proliferative state and validate the use of this factor as a useful proliferation marker and prognostic indicator in malignant and benign breast lesions.
Akt Stimulates Aerobic Glycolysis in Cancer Cells
Authors: Elstrom Rebecca L. , Bauer Daniel E. , Buzzai Monica , Karnauskas Robyn , Harris Marian H. , Plas David R. , Zhuang Hongming , Cinalli Ryan M. , Alavi Abass , Rudin Charles M. , Thompson Craig B.
Published: September 2005

Cancer cells frequently display high rates of aerobic glycolysis in comparison to their nontransformed counterparts, although the molecular basis of this phenomenon remains poorly understood. Constitutive activity of the serine/threonine kinase Akt is a common perturbation observed in malignant cells. Surprisingly, although Akt activity is sufficient to promote leukemogenesis in nontransformed hematopoietic precursors and maintenance of Akt activity was required for rapid disease progression, the expression of activated Akt did not increase the proliferation of the premalignant or malignant cells in culture. However, Akt stimulated glucose consumption in transformed cells without affecting the rate of oxidative phosphorylation. High rates of aerobic glycolysis were also identified in human glioblastoma cells possessing but not those lacking constitutive Akt activity. Akt-expressing cells were more susceptible than control cells to death after glucose withdrawal. These data suggest that activation of the Akt oncogene is sufficient to stimulate the switch to aerobic glycolysis characteristic of cancer cells and that Akt activity renders cancer cells dependent on aerobic glycolysis for continued growth and survival.