bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Antitumor and Antivascular Effects of AVE8062 in Ovarian Carcinoma
Authors: Kim Tae Jin , Ravoori Murali , Landen Charles N. , Kamat Aparna A. , Han Liz Y. , Lu Chunhua , Lin Yvonne G. , Merritt William M. , Jennings Nicholas , Spannuth Whitney A. , Langley Robert , Gershenson David M. , Coleman Robert L. , Kundra Vikas , Sood Anil K.
Published: March 2023

Abstract
The purpose of this study was to examine the therapeutic efficacy and underlying mechanisms of action of a vascular-disrupting agent, AVE8062, and to determine its effects on tumor metabolic activity. The in vitro and in vivo effects of AVE8062 alone and in combination with docetaxel were tested in chemotherapy-sensitive and chemotherapy-resistant ovarian cancer models. Tumors were analyzed for necrosis, microvessel density, endothelial cell apoptosis, and proliferation following treatment. The effect of AVE8062 on tumor regression and metabolic activity was examined by magnetic resonance (MR) or by [18F]fluorodeoxyglucose ([18F]FDG) uptake by positron emission tomography (PET) with MR imaging, respectively. AVE8062 monotherapy was effective in inhibiting tumor growth in all models (range 43–51% versus control; P < 0.05). Combination therapy was even more effective in inhibiting tumor growth (range 76–90% compared with controls, P < 0.01). AVE8062 in combination with chemotherapy significantly prolonged survival in HeyA8-injected mice (P < 0.001) compared with other groups. AVE8062-based therapy resulted in rapid development of central tumor necrosis, decreased microvessel density, decreased proliferation, and induction of apoptosis of tumor-associated endothelial cells. MR imaging showed regression of established HeyA8 ovarian tumors and [18F]FDG PET with MR showed rapid decrease in metabolic activity after AVE8062 therapy. Combination of AVE8062 plus docetaxel results in potent inhibition of ovarian cancer growth. These results suggest that AVE8062 may be useful as a clinical therapeutic approach for ovarian cancer patients and that functional [18F]FDG PET imaging may predict clinical response before an anatomic reduction in tumor size. [Cancer Res 2007;67(19):9337–45]
Data from Inhibition of Cyclooxygenase-2 Suppresses Lymph Node Metastasis via Reduction of Lymphangiogenesis
Authors: Iwata Caname , Kano Mitsunobu R. , Komuro Akiyoshi , Oka Masako , Kiyono Kunihiko , Johansson Erik , Morishita Yasuyuki , Yashiro Masakazu , Hirakawa Kosei , Kaminishi Michio , Miyazono Kohei
Published: March 2023

Abstract
Cyclooxygenase-2 (COX-2) inhibitor has been reported to suppress tumor progression. However, it is unclear whether this inhibitor can also prevent lymphatic metastasis. To determine the effects of COX-2 inhibitor on lymphatic metastasis, etodolac, a COX-2 inhibitor, was given p.o. to mice bearing orthotopic xenografts or with carcinomatous peritonitis induced with a highly metastatic human diffuse-type gastric carcinoma cell line, OCUM-2MLN. Tumor lymphangiogenesis was significantly decreased in etodolac-treated mice compared with control mice. Consistent with this decrease in lymphangiogenesis, the total weight of metastatic lymph nodes was less in etodolac-treated mice than in control mice. Immunohistochemical analysis revealed that the major source of vascular endothelial growth factor-C (VEGF-C) and VEGF-D was F4/80-positive macrophages in our models. The mRNA levels of VEGF-C in mouse macrophage-like RAW264.7 cells, as well as those in tumor tissues, were suppressed by etodolac. The growth of human dermal lymphatic microvascular endothelial cells was also suppressed by etodolac. Supporting these findings, etodolac also inhibited lymphangiogenesis in a model of chronic aseptic peritonitis, suggesting that COX-2 can enhance lymphangiogenesis in the absence of cancer cells. Our findings suggest that COX-2 inhibitor may be useful for prophylaxis of lymph node metastasis by reducing macrophage-mediated tumor lymphangiogenesis. [Cancer Res 2007;67(21):10181–9]
Data from Combination of Tumor Site–Located CTL-Associated Antigen-4 Blockade and Systemic Regulatory T-Cell Depletion Induces Tumor-Destructive Immune Responses
Authors: Tuve Sebastian , Chen Bing-Mae , Liu Ying , Cheng Tian-Lu , Touré Papa , Sow Papa Salif , Feng Qinghua , Kiviat Nancy , Strauss Robert , Ni Shaoheng , Li Zong-Yi , Roffler Steve R. , Lieber André
Published: March 2023

Abstract
Accumulating data indicate that tumor-infiltrating regulatory T cells (Treg) are present in human tumors and locally suppress antitumor immune cells. In this study, we found an increased Treg/CD8 ratio in human breast and cervical cancers. A similar intratumoral lymphocyte pattern was observed in a mouse model for cervical cancer (TC-1 cells). In this model, systemic Treg depletion was inefficient in controlling tumor growth. Furthermore, systemic CTL-associated antigen-4 (CTLA-4) blockade, an approach that can induce tumor immunity in other tumor models, did not result in TC-1 tumor regression but led to spontaneous development of autoimmune hepatitis. We hypothesized that continuous expression of an anti–CTLA-4 antibody localized to the tumor site could overcome Treg-mediated immunosuppression and locally activate tumor-reactive CD8+ cells, without induction of autoimmunity. To test this hypothesis, we created TC-1 cells that secrete a functional anti–CTLA-4 antibody (TC-1/αCTLA-4-γ1 cells). When injected into immunocompetent mice, the growth of TC-1/αCTLA-4-γ1 tumors was delayed compared with control TC-1 cells and accompanied by a reversion of the intratumoral Treg/CD8 ratio due to an increase in tumor-infiltrating IFNγ-producing CD8+ cells. When local anti–CTLA-4 antibody production was combined with Treg inhibition, permanent TC-1 tumor regression and immunity was induced. Importantly, no signs of autoimmunity were detected in mice that received local CTLA-4 blockade alone or in combination with Treg depletion. [Cancer Res 2007;67(12):5929–39]
Data from Involvement of RNA Helicases p68 and p72 in Colon Cancer
Authors: Shin Sook , Rossow Kari L. , Grande Joseph P. , Janknecht Ralf
Published: March 2023

Abstract
The homologous proteins p68 and p72 are members of the DEAD box family of RNA helicases. Here, we show that expression of both of these helicases strongly increases during the polyp→adenoma→adenocarcinoma transition in the colon. Furthermore, p68 and p72 form complexes with β-catenin and promote the ability of β-catenin to activate gene transcription. Conversely, simultaneous knockdown of p68 and p72 leads to reduced expression of the β-catenin–regulated genes, c-Myc, cyclin D1, c-jun, and fra-1, all of which are proto-oncogenes. Moreover, transcription of the cell cycle inhibitor p21WAF1/CIP1, whose expression is suppressed by c-Myc, is enhanced on p68/p72 knockdown. Thus, p68/p72 may contribute to colon cancer formation by directly up-regulating proto-oncogenes and indirectly by down-regulating the growth suppressor p21WAF1/CIP1. Accordingly, knockdown of p68 and p72 in colon cancer cells inhibits their proliferation and diminishes their ability to form tumors in vivo. Altogether, these results suggest that p68/p72 overexpression is not only a potential marker of colon cancer but is also causally linked to this disease. Therefore, p68 and p72 may be novel targets in the combat against colon cancer. [Cancer Res 2007;67(16):7572–8]
Data from Targeting Human γδ T Cells with Zoledronate and Interleukin-2 for Immunotherapy of Hormone-Refractory Prostate Cancer
Authors: Dieli Francesco , Vermijlen David , Fulfaro Fabio , Caccamo Nadia , Meraviglia Serena , Cicero Giuseppe , Roberts Andrew , Buccheri Simona , D'Asaro Matilde , Gebbia Nicola , Salerno Alfredo , Eberl Matthias , Hayday Adrian C.
Published: March 2023

Abstract
The increasing evidence that γδ T cells have potent antitumor activity suggests their value in immunotherapy, particularly in areas of unmet need such as metastatic carcinoma. To this end, we initiated a phase I clinical trial in metastatic hormone-refractory prostate cancer to examine the feasibility and consequences of using the γδ T-cell agonist zoledronate, either alone or in combination with low-dose interleukin 2 (IL-2), to activate peripheral blood γδ cells. Nine patients were enlisted to each arm. Neither treatment showed appreciable toxicity. Most patients were treated with zoledronate + IL-2, but conversely only two treated with zoledronate displayed a significant long-term shift of peripheral γδ cells toward an activated effector-memory–like state (TEM), producing IFN-γ and perforin. These patients also maintained serum levels of tumor necrosis factor–related apoptosis inducing ligand (TRAIL), consistent with a parallel microarray analysis showing that TRAIL is produced by γδ cells activated via the T-cell receptor and IL-2. Moreover, the numbers of TEM γδ cells showed a statistically significant correlation with declining prostate-specific antigen levels and objective clinical outcomes that comprised three instances of partial remission and five of stable disease. By contrast, most patients treated only with zoledronate failed to sustain either γδ cell numbers or serum TRAIL, and showed progressive clinical deterioration. Thus, zoledronate + IL-2 represents a novel, safe, and feasible approach to induce immunologic and clinical responses in patients with metastatic carcinomas, potentially providing a substantially increased window for specific approaches to be administered. Moreover, γδ cell phenotypes and possibly serum TRAIL may constitute novel biomarkers of prognosis upon therapy with zoledronate + IL-2 in metastatic carcinoma. [Cancer Res 2007;67(15):7450–7]
Data from Nuclear Factor of Activated T3 Is a Negative Regulator of Ras-JNK1/2-AP-1–Induced Cell Transformation
Authors: Yao Ke , Cho Yong-Yeon , Bergen H. Robert , Madden Benjamin J. , Choi Bu Young , Ma Wei-Ya , Bode Ann M. , Dong Zigang
Published: March 2023

Abstract
The c-jun-NH2-kinases (JNK) play a critical role in tumor promoter–induced cell transformation and apoptosis. Here, we showed that the nuclear factor of activated T3 (NFAT3) is phosphorylated by JNK1 or JNK2 at Ser213 and Ser217, which are located in the conserved SP motif. The transactivation domain of NFAT3 is found between amino acids (aa) 113 and 260 and includes the phosphorylation targets of JNK1 and JNK2. NFAT3 transactivation activity was suppressed in JNK1−/− or JNK2−/− mouse embryonic fibroblast (MEF) cells compared with wild-type MEF cells. Moreover, a 3xNFAT-luc reporter gene assay indicated that NFAT3 transcriptional activity was increased in a dose-dependent manner by JNK1 or JNK2. Double mutations at Ser213 and Ser217 suppressed NFAT3 transactivation activity; and SP600125, a JNK inhibitor, suppressed NFAT3-induced 3xNFAT-luciferase activity. Knockdown of JNK1 or JNK2 suppressed foci formation in NIH3T3 cells. Importantly, ectopic expression of NFAT3 inhibited AP-1 activity and suppressed foci formation. Furthermore, knockdown of NFAT3 enhanced Ras-JNK1 or JNK2-induced foci formation in NIH3T3 cells. Taken together, these results provided direct evidence for the anti-oncogenic potential of the NFAT3 transcription factor. [Cancer Res 2007;67(18):8725–35]
Data from Human Papillomavirus 16 E5 Oncogene Contributes to Two Stages of Skin Carcinogenesis
Authors: Maufort John P. , Genther Williams Sybil M. , Pitot Henry C. , Lambert Paul F.
Published: March 2023

Abstract
High-risk human papillomaviruses (HPVs), which cause the vast majority of cervical cancer, other anogenital cancers, and a subset of head and neck squamous cell carcinomas, encode three oncogenes: E5, E6, and E7. To determine the oncogenic properties of HPV16 E5 in vivo, we previously generated K14E5 transgenic mice, in which expression of E5 was directed to the basal compartment of stratified squamous epithelia. In these mice, E5 induced epidermal hyperplasia and spontaneous skin tumors. In the current study, we determined how E5 contributes to tumor formation in the skin using a multistage model for skin carcinogenesis that specifies the role of genes in three stages: initiation, promotion, and malignant progression. Both initiation and promotion are required steps for papilloma formation. K14E5 mice treated with the initiating agent 7,12-dimethylbenz(a)anthracene (DMBA) developed more papillomas than like-treated nontransgenic mice, whereas neither K14E5 nor nontransgenic mice treated with the promoting agent 12-O-tetradecanoylphorbol-13-acetate (TPA) developed papillomas. K14E5 mice treated with both DMBA and TPA to induce large numbers of papillomas had a higher incidence and earlier onset of carcinoma progression compared with like-treated nontransgenic mice. Thus, HPV16 E5 contributes to two stages of skin carcinogenesis: promotion and progression. The progressive neoplastic disease in K14E5 mice differed from that in nontransgenic mice in that benign tumors converted from exophytic to endophytic papillomas before progressing to carcinomas. Initial genetic and immunohistopathologic analyses did not determine the underlying basis for this distinct morphology, which correlates with a highly penetrant neoplastic phenotype. [Cancer Res 2007;67(13):6106–7]
Data from Her-2 Overexpression Increases the Metastatic Outgrowth of Breast Cancer Cells in the Brain
Authors: Palmieri Diane , Bronder Julie L. , Herring Jeanne M. , Yoneda Toshiyuki , Weil Robert J. , Stark Andreas M. , Kurek Raffael , Vega-Valle Eleazar , Feigenbaum Lionel , Halverson Douglas , Vortmeyer Alexander O. , Steinberg Seth M. , Aldape Kenneth , Steeg Patricia S.
Published: March 2023

Abstract
Retrospective studies of breast cancer patients suggest that primary tumor Her-2 overexpression or trastuzumab therapy is associated with a devastating complication: the development of central nervous system (brain) metastases. Herein, we present Her-2 expression trends from resected human brain metastases and data from an experimental brain metastasis assay, both indicative of a functional contribution of Her-2 to brain metastatic colonization. Of 124 archival resected brain metastases from breast cancer patients, 36.2% overexpressed Her-2, indicating an enrichment in the frequency of tumor Her-2 overexpression at this metastatic site. Using quantitative real-time PCR of laser capture microdissected epithelial cells, Her-2 and epidermal growth factor receptor (EGFR) mRNA levels in a cohort of 12 frozen brain metastases were increased up to 5- and 9-fold, respectively, over those of Her-2–amplified primary tumors. Co-overexpression of Her-2 and EGFR was also observed in a subset of brain metastases. We then tested the hypothesis that overexpression of Her-2 increases the colonization of breast cancer cells in the brain in vivo. A subclone of MDA-MB-231 human breast carcinoma cells that selectively metastasizes to brain (231-BR) overexpressed EGFR; 231-BR cells were transfected with low (4- to 8-fold) or high (22- to 28-fold) levels of Her-2. In vivo, in a model of brain metastasis, low or high Her-2–overexpressing 231-BR clones produced comparable numbers of micrometastases in the brain as control transfectants; however, the Her-2 transfectants yielded 3-fold greater large metastases (>50 μm2; P < 0.001). Our data indicate that Her-2 overexpression increases the outgrowth of metastatic tumor cells in the brain in this model system. [Cancer Res 2007;67(9):4190–8]
Data from The Putative Tumor Suppressor Gene PTPN13/PTPL1 Induces Apoptosis through Insulin Receptor Substrate-1 Dephosphorylation
Authors: Dromard Mathilde , Bompard Guillaume , Glondu-Lassis Murielle , Puech Carole , Chalbos Dany , Freiss Gilles
Published: March 2023

Abstract
The protein tyrosine phosphatase (PTP) PTPL1/PTPN13 is a candidate tumor suppressor gene. Indeed, PTPL1 activity has been reported recently to be decreased through somatic mutations, allelic loss, or promoter methylation in some tumors. We showed previously that its expression was necessary for inhibition of Akt activation and induction of apoptosis by antiestrogens in breast cancer cells. Implications of the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway in cancer progression are now well established, and our study was therefore designed to define whether PTPL1 is sufficient to inhibit this pathway and, if so, to identify a direct substrate of this PTP, which may trigger a proapoptotic effect. We first show by complementary approaches that PTPL1 specifically dephosphorylates insulin receptor substrate-1 (IRS-1) in vitro and in cellulo. Next, our experiments using a dominant-negative mutant and RNA interference confirm the crucial role of PTPL1 in IRS-1 dephosphorylation. Finally, we report that PTPL1 expression is sufficient to block the IRS-1/PI3K/Akt signaling pathway, to inhibit the insulin-like growth factor-I effect on cell survival, and to induce apoptosis. Altogether, these data provide the first evidence for a direct positive role of the putative tumor suppressor gene PTPL1/PTPN13 on apoptosis and identify its target in the IRS-1/PI3K/Akt signaling pathway. [Cancer Res 2007;67(14):6806–13]
Data from Aromatase Expression Predicts Survival in Women with Early-Stage Non–Small Cell Lung Cancer
Authors: Mah Vei , Seligson David B. , Li Ai , Márquez Diana C. , Wistuba Ignacio I. , Elshimali Yahya , Fishbein Michael C. , Chia David , Pietras Richard J. , Goodglick Lee
Published: March 2023

Abstract
Estrogen signaling is critical in the progression of tumors that bear estrogen receptors. In most patients with breast cancer, inhibitors that block interactions of estrogen with its receptors or suppress the production of endogenous estrogens are important interventions in the clinic. Recent evidence now suggests that estrogen also contributes to the pathogenesis of non–small cell lung cancer (NSCLC). We used a human lung cancer xenograph model system to analyze the effect of aromatase or estradiol on tumor growth. We further examined the level of protein expression of aromatase in 422 patients with NSCLC using a high-density tissue microarray. Results were confirmed and validated on an independent patient cohort (n = 337). Lower levels of aromatase predicted a greater chance of survival in women 65 years and older. Within this population, the prognostic value of aromatase was greatest in earlier stage lung cancer (stage I/II). In addition, for women with no history of smoking, lower aromatase levels were a strong predictor of survival. Our findings implicate aromatase as an early-stage predictor of survival in some women with NSCLC. We predict that women whose lung cancers have higher levels of aromatase might be good candidates for targeted treatment with aromatase inhibitors. [Cancer Res 2007;67(21):10484–90]
Data from Macrophages Mediate Inflammation-Enhanced Metastasis of Ovarian Tumors in Mice
Authors: Robinson-Smith Toni M. , Isaacsohn Idit , Mercer Carol A. , Zhou Mingfu , Van Rooijen Nico , Husseinzadeh Nader , McFarland-Mancini Molly M. , Drew Angela F.
Published: March 2023

Abstract
The tumor microenvironment is known to have a profound effect on tumor progression in a highly context-specific manner. We have investigated whether peritoneal inflammation plays a causative role in ovarian tumor metastasis, a poorly understood process. Implantation of human ovarian tumor cells into the ovaries of severe combined immunodeficient mice resulted in peritoneal inflammation that corresponds temporally with tumor cell dissemination from the ovaries. Enhancement of the inflammatory response with thioglycolate accelerated the development of ascites and metastases. Suppression of inflammation with acetyl salicylic acid delayed ascites development and reduced tumor implant formation. A similar prometastatic effect for inflammation was observed when tumor cells were injected directly into the peritoneum of severe combined immunodeficient mice, and in a syngeneic immunocompetent mouse model. Inflammation-modulating treatments did not affect primary tumor development or in vitro tumor cell growth. Depletion of peritoneal macrophages, but not neutrophils or natural killer cells, reduced tumor progression, as assessed by ascites formation and peritoneal metastasis. We conclude that inflammation facilitates ovarian tumor metastasis by a mechanism largely mediated by macrophages, and which may involve stromal vascular endothelial growth factor production. The confirmation of these findings in immunocompetent mice suggests relevance to human disease. Identifying the mechanisms by which macrophages contribute to tumor metastasis may facilitate the development of new therapies specifically targeting immune cell products in the tumor microenvironment. [Cancer Res 2007;67(12):5708–16]
Data from B7-H3 Ligand Expression by Prostate Cancer: A Novel Marker of Prognosis and Potential Target for Therapy
Authors: Roth Timothy J. , Sheinin Yuri , Lohse Christine M. , Kuntz Susan M. , Frigola Xavier , Inman Brant A. , Krambeck Amy E. , Mckenney Maureen E. , Karnes R. Jeffrey , Blute Michael L. , Cheville John C. , Sebo Thomas J. , Kwon Eugene D.
Published: March 2023

Abstract
B7 coregulatory ligands can be aberrantly expressed in human disease. In the context of cancer, these ligands may act as antigen-specific inhibitors of T-cell–mediated antitumoral immunity. We recently reported that B7-H1 expression by carcinomas of the kidney and bladder portends aggressive disease and diminished survival. The expression of these proteins in prostate cancer, however, has not been investigated. We evaluated B7-H3 and B7-H1 protein expression in the pathologic specimens of 338 men treated for clinically localized prostate cancer between 1995 and 1998 with radical retropubic prostatectomy. Expression levels of B7-H3 in prostate cancer were correlated with pathologic indicators of aggressive cancer as well as clinical outcome. We report that B7-H3 is uniformly and aberrantly expressed by adenocarcinomas of the prostate, high-grade prostatic intraepithelial neoplasia, and four prostate cancer cell lines, whereas B7-H1 is rarely expressed. B7-H3 is expressed by benign prostatic epithelia, although at a more reduced level relative to neoplastic tissue. Increasing levels of B7-H3 intensity correlate with worsening clinicopathologic features of prostate cancer. Marked B7-H3 intensity, present in 67 (19.8%) specimens, confers a >4-fold increased risk of cancer progression after surgery (risk ratio, 4.42; P < 0.001). A survey of normal tissues revealed that B7-H3 is expressed within the liver, urothelium, and fetal kidney. In summary, B7-H3 is aberrantly expressed in all prostate cancers and represents an independent predictor of cancer progression following surgery. Moreover, B7-H3 encompasses a novel diagnostic and potential therapeutic target for the clinical management of prostate cancer and, perhaps, other malignancies as well. [Cancer Res 2007;67(16):7893–900]
Data from The Unhydrolyzable Fenretinide Analogue 4-Hydroxybenzylretinone Induces the Proapoptotic Genes GADD153 (CHOP) and Bcl-2–Binding Component 3 (PUMA) and Apoptosis that Is Caspase- Dependent and Independent of the Retinoic Acid Receptor
Authors: Anding Allyson L. , Chapman Jason S. , Barnett Derek W. , Curley Robert W. , Clagett-Dame Margaret
Published: March 2023

Abstract
The synthetic retinoid N-(4-hydroxyphenyl)retinamide (4-HPR) induces apoptosis in a variety of cell lines and has shown promise as an anticancer agent both in vitro and in vivo. The clinical dose of 4-HPR, however, is limited by residual-associated toxicities, indicating a need for a less toxic drug. In this study, we show that 4-hydroxybenzylretinone (4-HBR), the unhydrolyzable analogue of 4-HPR, is effective in producing apoptosis in a variety of 4-HPR–sensitive cell lines, including breast cancer, neuroblastoma, and leukemia cells. We also show through the use of a pan-caspase inhibitor that this 4-HBR–induced apoptosis is dependent, at least in part, on caspase activity. 4-HBR is shown to exhibit binding to the retinoic acid receptors (RAR) at concentrations necessary to induce cell death and induces expression of all-trans-retinoic acid–responsive genes that can be blocked by a RAR pan-antagonist. However, through the use of this RAR pan-antagonist, 4-HBR–induced apoptosis and cell death is shown to be independent of the RAR signaling pathway. To further characterize the mechanism of action of 4-HBR, expression of the endoplasmic reticulum stress–induced genes GADD153 and Bcl-2–binding component 3 was examined. These mRNAs are shown to be rapidly induced in 4-HBR–treated and 4-HPR–treated breast cancer cells, and this up-regulation is also shown to be independent of the RARs. These results suggest that a stress-mediated apoptotic cascade is involved in the mechanism of action of these retinoids. [Cancer Res 2007;67(13):6270–7]
Data from Antagonism of HOX/PBX Dimer Formation Blocks the In vivo Proliferation of Melanoma
Authors: Morgan Richard , Pirard Patricia Macanas , Shears Liesl , Sohal Jastinder , Pettengell Ruth , Pandha Hardev S.
Published: March 2023

Abstract
Malignant melanoma is a cancer that arises from melanocyte cells in a complex but well-studied process, and which can only be successfully treated prior to metastasis as it is highly resistant to conventional therapies. A number of recent reports have indicated that members of the HOX family of homeodomain-containing transcription factors are deregulated in melanoma, and may actually be required to maintain proliferation. In this report, we describe the use of a novel, cell-permeable antagonist of the interaction between HOX proteins and PBX, a second homeodomain-containing transcription factor that modifies HOX activity. This antagonist can block the growth of murine B16 cells and trigger apoptosis both in vitro and in vivo when administered to mice with flank tumors. [Cancer Res 2007;67(12):5806–13]
Data from Cutaneous Human Papillomaviruses Down-regulate AKT1, whereas AKT2 Up-regulation and Activation Associates with Tumors
Authors: O'Shaughnessy Ryan F.L. , Akgũl Baki , Storey Alan , Pfister Herbert , Harwood Catherine A. , Byrne Carolyn
Published: March 2023

Abstract
Epithelial tumorigenesis has been linked to AKT up-regulation. Human papillomaviruses (HPV) cause anogenital cancers and anogenital HPV infection up-regulates AKT activity. Mounting evidence points to a role for cutaneous HPVs as etiologic factors in skin tumorigenesis. High-risk cutaneous β HPVs have been linked to carcinogenesis in immunosuppressed patients, and high-risk cutaneous HPV8 genes enhance tumorigenesis in transgenic mice. We find that, in contrast to anogenital HPVs, cutaneous HPV8 early genes down-regulate epidermal AKT activity by down-regulating AKT1 isoform levels. This down-regulation occurs before papilloma formation or tumorigenesis and leads to cutaneous differentiation changes that may weaken the epidermal squame for viral release. We find that, in viral warts (papillomas) and HPV gene-induced epidermal tumors, AKT activity can be activated focally by up-regulation and phosphorylation of the AKT2 isoform. In squamous cell carcinomas (SCC), AKT1 down-regulation is also common, consistent with a viral influence, whereas AKT2 up-regulation is widespread. Activation of up-regulated AKT2 by serine phosphorylation associates with high-grade tumors. Our data suggest that AKT2 up-regulation is characteristic of SCC and that coincident AKT2 activation through serine phosphorylation correlates with malignancy. These findings highlight differences between the effects of anogenital and cutaneous HPV on epithelial AKT activity and furthermore show that AKT isoforms can behave differently during epidermal tumorigenesis. These findings also suggest AKT2 as a possible therapeutic tumor target in SCC. [Cancer Res 2007;67(17):8207–15]
Data from Oncogenic Potential of the Nuclear Receptor Coregulator Proline-, Glutamic Acid–, Leucine-Rich Protein 1/Modulator of the Nongenomic Actions of the Estrogen Receptor
Authors: Rajhans Rajib , Nair Sujit , Holden Alan H. , Kumar Rakesh , Tekmal Rajeshwar Rao , Vadlamudi Ratna K.
Published: March 2023

Abstract
Proline-, glutamic acid–, leucine-rich protein 1 (PELP1), a novel nuclear receptor coactivator, and its expression is deregulated in hormone-dependent cancers, including those of the breast, endometrium, and ovary. PELP1 interacts with estrogen receptor and modulates its genomic and nongenomic functions. In this study, we examined whether PELP1 functions as an oncogene. The overexpression of PELP1 in fibroblasts and epithelial model cells resulted in cellular transformation. PELP1 also enhanced the transformation potential of c-Src kinase in focus formation assays, and PELP1 overexpression potentiated estradiol-mediated cell migratory potential and anchorage-independent growth. Using PELP1-small interfering RNA, we provided evidence that endogenous PELP1 plays an essential role in E2-mediated anchorage-independent growth, cell migration, and cytoskeletal changes. When compared with control vector transfectants, breast cancer cells stably overexpressing PELP1 showed a rapid tumor growth in xenograft studies. Immunohistochemical analysis of PELP1 expression using a tumor progression array of 252 breast carcinomas and normal breast tissue specimens revealed that PELP1 expression is deregulated to a greater degree in higher grade node-positive invasive tumors than in normal breast tissue or ductal carcinoma in situ. Our data suggest that PELP1 is a potential oncogene, that its expression is deregulated during cancer progression, and that PELP1 may play a role in oncogenesis. [Cancer Res 2007;67(11):5505–12]
Data from Combined Natural Killer T-Cell–Based Immunotherapy Eradicates Established Tumors in Mice
Authors: Teng Michele W.L. , Westwood Jennifer A. , Darcy Phillip K. , Sharkey Janelle , Tsuji Moriya , Franck Richard W. , Porcelli Steven A. , Besra Gurdyal S. , Takeda Kazuyoshi , Yagita Hideo , Kershaw Michael H. , Smyth Mark J.
Published: March 2023

Abstract
A rational monoclonal antibody (mAb)-based antitumor therapy approach has previously been shown to eradicate various established experimental and carcinogen-induced tumors in a majority of mice. This therapy comprised an agonistic mAb reactive with tumor necrosis factor–related apoptosis-inducing ligand receptor (DR5), expressed by tumor cells, an agonistic anti-CD40 mAb to mature dendritic cells, and an agonistic anti-4-1BB mAb to costimulate CD8+ T cells. Because agonists of CD40 have been toxic in patients, we were interested in substituting anti-CD40 mAb with other dendritic cell–maturing agents, such as glycolipid ligands recognized by invariant natural killer T (iNKT) cells. Here, we show that CD1d-restricted glycolipid ligands for iNKT cells effectively substitute for anti-CD40 mAb and reject established experimental mouse breast and renal tumors when used in combination with anti-DR5 and anti-4-1BB mAbs (termed “NKTMab” therapy). NKTMab therapy–induced tumor rejection was dependent on CD4+ and CD8+ T cells, NKT cells, and the cytokine IFN-γ. NKTMab therapy containing either α-galactosylceramide (α-GC) or α-C-galactosylceramide (α-c-GC) at high concentrations induced similar rates of tumor rejection in mice; however, toxicity was observed at the highest doses of α-GC (>250 ng/injection), limiting the use of this glycolipid. By contrast, even very low doses of α-c-GC (25 ng/injection) retained considerable antitumor activity when used in combination with anti-DR5/anti-4-1BB, and thus, α-c-GC showed a considerably greater therapeutic index. In summary, sequential tumor cell apoptosis and amplification of dendritic cell function by NKT cell agonists represents an exciting and novel approach for cancer treatment. [Cancer Res 2007;67(15):7495–504]
Data from Substrate Overlap between Mrp4 and Abcg2/Bcrp Affects Purine Analogue Drug Cytotoxicity and Tissue Distribution
Authors: Takenaka Kazumasa , Morgan Jessica A. , Scheffer George L. , Adachi Masashi , Stewart Clinton F. , Sun Daxi , Leggas Markos , Ejendal Karin F.K. , Hrycyna Christine A. , Schuetz John D.
Published: March 2023

Abstract
The use of probe substrates and combinations of ATP-binding cassette (ABC) transporter knockout (KO) animals may facilitate the identification of common substrates between apparently unrelated ABC transporters. An unexpectedly low concentration of the purine nucleotide analogue, 9-(2-(phosphonomethoxy)ethyl)-adenine (PMEA), and up-regulation of Abcg2 in some tissues of the Mrp4 KO mouse prompted us to evaluate the possibility that Abcg2 might transport purine-derived drugs. Abcg2 transported and conferred resistance to PMEA. Moreover, a specific Abcg2 inhibitor, fumitremorgin C, both increased PMEA accumulation and reversed Abcg2-mediated PMEA resistance. We developed Mrp4 and Abcg2 double KO mice and used both single KOs of Abcg2 and Mrp4 mice to assess the role of these transporters in vivo. Abcg2 contributed to PMEA accumulation in a variety of tissues, but in some tissues, this contribution was only revealed by the concurrent absence of Mrp4. Abcg2 also transported and conferred resistance to additional purine analogues, such as the antineoplastic, 2-chloro-2′-deoxyadenosine (cladribine) and puromycin, a protein synthesis inhibitor that is often used as a dominant selectable marker. Purine analogues interact with ABCG2 by a site distinct from the prazosin binding site as shown by their inability to displace the substrate analogue and photoaffinity tag [125I]iodoarylazidoprazosin. These studies show that Abcg2, like Mrp4, transports and confers resistance to purine nucleoside analogues and suggest that these two transporters work in parallel to affect drug cytotoxicity and tissue distribution. This new knowledge will facilitate an understanding of how Abcg2 and Mrp4, separately and in combination, protect against purine analogue host toxicity as well as resistance to chemotherapy. [Cancer Res 2007;67(14):6965–72]
Data from Loss of Betaglycan Expression in Ovarian Cancer: Role in Motility and Invasion
Authors: Hempel Nadine , How Tam , Dong Mei , Murphy Susan K. , Fields Timothy A. , Blobe Gerard C.
Published: March 2023

Abstract
The transforming growth factor-β (TGF-β) superfamily members, TGF-β, activin, and inhibin, all have prominent roles in regulating normal ovarian function. Betaglycan, or the type III TGF-β receptor, is a coreceptor that regulates TGF-β, activin, and inhibin signaling. Here, we show that betaglycan expression is frequently decreased or lost in epithelial derived ovarian cancer at both the mRNA and protein level, with the degree of loss correlating with tumor grade. Treatment of ovarian cancer cell lines with the methyltransferase inhibitor 5-aza-2-deoxycytidine and the histone deacetylase inhibitor trichostatin A resulted in significant synergistic induction of betaglycan message levels and increased betaglycan protein expression, indicating that epigenetic silencing may play a role in the loss of betaglycan expression observed in ovarian cancer. Although restoring betaglycan expression in Ovca429 ovarian cancer cells is not sufficient to restore TGF-β–mediated inhibition of proliferation, betaglycan significantly inhibits ovarian cancer cell motility and invasiveness. Furthermore, betaglycan specifically enhances the antimigratory effects of inhibin and the ability of inhibin to repress matrix metalloproteinase levels in these cells. These results show, for the first time, epigenetic regulation of betaglycan expression in ovarian cancer, and a novel role for betaglycan in regulating ovarian cancer motility and invasiveness. [Cancer Res 2007;67(11):5231–8]
Data from Targeting Human Medulloblastoma: Oncolytic Virotherapy with Myxoma Virus Is Enhanced by Rapamycin
Authors: Lun Xue Qing , Zhou Hongyuan , Alain Tommy , Sun Beichen , Wang Limei , Barrett John W. , Stanford Marianne M. , McFadden Grant , Bell John , Senger Donna L. , Forsyth Peter A.
Published: March 2023

Abstract
We have shown previously the oncolytic potential of myxoma virus in a murine xenograft model of human glioma. Here, we show that myxoma virus used alone or in combination with rapamycin is effective and safe when used in experimental models of medulloblastoma in vitro and in vivo. Nine of 10 medulloblastoma cell lines tested were susceptible to lethal myxoma virus infection, and pretreatment of cells with rapamycin increased the extent of in vitro oncolysis. Intratumoral injection of live myxoma virus when compared with control inactivated virus prolonged survival in D341 and Daoy orthotopic human medulloblastoma xenograft mouse models [D341 median survival: 21 versus 12.5 days; P = 0.0008; Daoy median survival: not reached (three of five mice apparently “cured” after 223 days) versus 75 days; P = 0.0021]. Rapamycin increased the extent of viral oncolysis, “curing” most Daoy tumor-bearing mice and reducing or eliminating spinal cord and ventricle metastases. Rapamycin enhanced tumor-specific myxoma virus replication in vivo and prolonged survival of D341 tumor-bearing mice (median survival of mice treated with live virus (LV) and rapamycin, versus LV alone, versus rapamycin alone, versus inactivated virus: 25 days versus 19, 13, and 11 days, respectively; P < 0.0001). Rapamycin increased the levels of constitutively activated Akt in Daoy and D341 cells, which may explain its ability to enhance myxoma virus oncolysis. These observations suggest that myxoma virus may be an effective oncolytic agent against medulloblastoma and that combination therapy with signaling inhibitors that modulate activity of the phosphatidylinositol 3-kinase/Akt pathway will further enhance the oncolytic potential of myxoma virus. [Cancer Res 2007;67(18):8818–27]
Data from Tissue Inhibitor of Metalloproteinases-1 Promotes Liver Metastasis by Induction of Hepatocyte Growth Factor Signaling
Authors: Kopitz Charlotte , Gerg Michael , Bandapalli Obul Reddy , Ister Dilek , Pennington Caroline J. , Hauser Stephanie , Flechsig Christin , Krell Hans-Willi , Antolovic Dalibor , Brew Keith , Nagase Hideaki , Stangl Manfred , Hann von Weyhern Claus W. , Brücher Björn L.D.M. , Brand Karsten , Coussens Lisa M. , Edwards Dylan R. , Krüger Achim
Published: March 2023

Abstract
Balanced expression of proteases and their inhibitors is one prerequisite of tissue homeostasis. Metastatic spread of tumor cells through the organism depends on proteolytic activity and is the death determinant for cancer patients. Paradoxically, increased expression of tissue inhibitor of metalloproteinases-1 (TIMP-1), a natural inhibitor of several endometalloproteinases, including matrix metalloproteinases and a disintegrin and metalloproteinase-10 (ADAM-10), in cancer patients is negatively correlated with their survival, although TIMP-1 itself inhibits invasion of some tumor cells. Here, we show that elevated stromal expression of TIMP-1 promotes liver metastasis in two independent tumor models by inducing the hepatocyte growth factor (HGF) signaling pathway and expression of several metastasis-associated genes, including HGF and HGF-activating proteases, in the liver. We also found in an in vitro assay that suppression of ADAM-10 is in principle able to prevent shedding of cMet, which may be one explanation for the increase of cell-associated HGF receptor cMet in livers with elevated TIMP-1. Similar TIMP-1–associated changes in gene expression were detected in livers of patients with metastatic colorectal cancer. The newly identified role of TIMP-1 to create a prometastatic niche may also explain the TIMP-1 paradoxon. [Cancer Res 2007;67(18):8615–23]
Data from Kallikrein 6 Induces E-Cadherin Shedding and Promotes Cell Proliferation, Migration, and Invasion
Authors: Klucky Britta , Mueller Regina , Vogt Ingeborg , Teurich Sibylle , Hartenstein Bettina , Breuhahn Kai , Flechtenmacher Christa , Angel Peter , Hess Jochen
Published: March 2023

Abstract
Recently, we described phorbol ester–induced expression of the brain and skin serine proteinase Bssp/kallikrein 6 (Klk6), the mouse orthologue of human KLK6, in mouse back skin and in advanced tumor stages of a well-established multistage tumor model. Here, we show KLK6 up-regulation in squamous skin tumors of human patients and in tumors of other epithelial tissues. Ectopic Klk6 expression in mouse keratinocyte cell lines induces a spindle-like morphology associated with accelerated proliferation, migration, and invasion capacity. We found reduced E-cadherin protein levels in the cell membrane and nuclear translocation of β-catenin in Klk6-expressing mouse keratinocytes and human HEK293 cells transfected with a KLK6 expression plasmid. Additionally, HEK293 cells exhibited induced T-cell factor–dependent transcription and impaired cell-cell adhesion in the presence of KLK6, which was accompanied by induced E-cadherin ectodomain shedding. Interestingly, tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-3 interfere with KLK6-induced E-cadherin ectodomain shedding and rescue the cell-cell adhesion defect in vitro, suggesting the involvement of matrix metalloproteinase and/or a disintegrin and metalloproteinase (ADAM) proteolytic activity. In line with this assumption, we found increased levels of the mature 62-kDa ADAM10 proteinase in cells expressing ectopic KLK6 compared with mock controls. Finally, enhanced epidermal keratinocyte proliferation and migration in concert with decreased E-cadherin protein levels are confirmed in an in vivo Klk6 transgenic mouse model. [Cancer Res 2007;67(17):8198–206]
Data from The Proteasome Inhibitor PS-341 (Bortezomib) Up-Regulates DR5 Expression Leading to Induction of Apoptosis and Enhancement of TRAIL-Induced Apoptosis Despite Up-Regulation of c-FLIP and Survivin Expression in Human NSCLC Cells
Authors: Liu Xiangguo , Yue Ping , Chen Shuzhen , Hu Liping , Lonial Sagar , Khuri Fadlo R. , Sun Shi-Yong
Published: March 2023

Abstract
The proteasome inhibitor PS-341 (bortezomib or Velcade), an approved drug for treatment of patients with multiple myeloma, is currently being tested in clinical trials against various malignancies, including lung cancer. Preclinical studies have shown that PS-341 induces apoptosis and enhances tumor necrosis factor–related apoptosis-inducing ligand (TRAIL)–induced apoptosis in human cancer cells with undefined mechanisms. In the present study, we show that PS-341 induced caspase-8–dependent apoptosis, cooperated with TRAIL to induce apoptosis, and up-regulated death receptor 5 (DR5) expression in human non–small cell lung cancer (NSCLC) cells. DR5 induction correlated with the ability of PS-341 to induce apoptosis. Blockage of PS-341–induced DR5 up-regulation using DR5 small interfering RNA (siRNA) rendered cells less sensitive to apoptosis induced by either PS-341 or its combination with TRAIL, indicating that DR5 up-regulation mediates PS-341–induced apoptosis and enhancement of TRAIL-induced apoptosis in human NSCLC cells. We exclude the involvement of c-FLIP and survivin in mediating these events because c-FLIP (i.e., FLIPS) and survivin protein levels were actually elevated on exposure to PS-341. Reduction of c-FLIP with c-FLIP siRNA sensitized cells to PS-341–induced apoptosis, suggesting that c-FLIP elevation protects cells from PS-341–induced apoptosis. Thus, the present study highlights the important role of DR5 up-regulation in PS-341–induced apoptosis and enhancement of TRAIL-induced apoptosis in human NSCLC cells. [Cancer Res 2007;67(10):4981–8]
Data from Carcinoembryonic Antigen Inhibits Anoikis in Colorectal Carcinoma Cells by Interfering with Trail-R2 (DR5) Signaling
Authors: Samara Raed N. , Laguinge Luciana M. , Jessup J. Milburn
Published: March 2023

Abstract
Carcinoembryonic antigen (CEA) is a tumor marker that is associated with metastasis, poor response to chemotherapy of colorectal cancer (CRC), and anoikis, a form of apoptosis caused by cell detachment from matrix that is dependent on TRAIL-R2 (DR5) and caspase-8 activation in CRC. Although CEA is a homophilic binding protein that may provide survival signals through homotypical cell aggregation, we now report that CEA binds TRAIL-R2 (DR5) directly in two-hybrid assays to decrease anoikis through the extrinsic pathway. Deletion of the PELPK sequence (delPELPK) of CEA (delPELPK CEA) restores sensitivity to anoikis while it maintains its cell aggregation function. Wild-type (WT) CEA also increases experimental hepatic metastasis, whereas the delPELPK CEA does not. Thus, membrane CEA interacts with DR5 to inhibit anoikis and increase metastatic potential in CRC. [Cancer Res 2007;67(10):4774–82]
Data from Ras Transformation of RIE-1 Cells Activates Cap-Independent Translation of Ornithine Decarboxylase: Regulation by the Raf/MEK/ERK and Phosphatidylinositol 3-Kinase Pathways
Authors: Origanti Sofia , Shantz Lisa M.
Published: March 2023

Abstract
Ornithine decarboxylase (ODC) is the first and generally rate-limiting enzyme in polyamine biosynthesis. Deregulation of ODC is critical for oncogenic growth, and ODC is a target of Ras. These experiments examine translational regulation of ODC in RIE-1 cells, comparing untransformed cells with those transformed by an activated Ras12V mutant. Analysis of the ODC 5′ untranslated region (5′UTR) revealed four splice variants with the presence or absence of two intronic sequences. All four 5′UTR species were found in both cell lines; however, variants containing intronic sequences were more abundant in Ras-transformed cells. All splice variants support internal ribosome entry site (IRES)–mediated translation, and IRES activity is markedly elevated in cells transformed by Ras. Inhibition of Ras effector targets indicated that the ODC IRES element is regulated by the phosphorylation status of the translation factor eIF4E. Dephosphorylation of eIF4E by inhibition of mitogen-activated protein/extracellular signal-regulated kinase (ERK) kinase (MEK) or the eIF4E kinase Mnk1/2 increases ODC IRES activity in both cell lines. When both the Raf/MEK/ERK and phosphatidylinositol 3-kinase/mammalian target of rapamycin pathways are inhibited in normal cells, ODC IRES activity is very low and cells arrest in G1. When these pathways are inhibited in Ras-transformed cells, cell cycle arrest does not occur and ODC IRES activity increases, helping to maintain high ODC activity. [Cancer Res 2007;67(10):4834–42]
Data from Mutations in BRAF and KRAS Converge on Activation of the Mitogen-Activated Protein Kinase Pathway in Lung Cancer Mouse Models
Authors: Ji Hongbin , Wang Zhenxiong , Perera Samanthi A. , Li Danan , Liang Mei-Chih , Zaghlul Sara , McNamara Kate , Chen Liang , Albert Mitchell , Sun Yanping , Al-Hashem Ruqayyah , Chirieac Lucian R. , Padera Robert , Bronson Roderick T. , Thomas Roman K. , Garraway Levi A. , Jänne Pasi A. , Johnson Bruce E. , Chin Lynda , Wong Kwok-Kin
Published: March 2023

Abstract
Mutations in the BRAF and KRAS genes occur in ∼1% to 2% and 20% to 30% of non–small-cell lung cancer patients, respectively, suggesting that the mitogen-activated protein kinase (MAPK) pathway is preferentially activated in lung cancers. Here, we show that lung-specific expression of the BRAF V600E mutant induces the activation of extracellular signal–regulated kinase (ERK)-1/2 (MAPK) pathway and the development of lung adenocarcinoma with bronchioloalveolar carcinoma features in vivo. Deinduction of transgene expression led to dramatic tumor regression, paralleled by dramatic dephosphorylation of ERK1/2, implying a dependency of BRAF-mutant lung tumors on the MAPK pathway. Accordingly, in vivo pharmacologic inhibition of MAPK/ERK kinase (MEK; MAPKK) using a specific MEK inhibitor, CI-1040, induced tumor regression associated with inhibition of cell proliferation and induction of apoptosis in these de novo lung tumors. CI-1040 treatment also led to dramatic tumor shrinkage in murine lung tumors driven by a mutant KRas allele. Thus, somatic mutations in different signaling intermediates of the same pathway induce exquisite dependency on a shared downstream effector. These results unveil a potential common vulnerability of BRAF and KRas mutant lung tumors that potentially affects rational deployment of MEK targeted therapies to non–small-cell lung cancer patients. [Cancer Res 2007;67(10):4933–9]