bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Cationic Albumin–Conjugated Pegylated Nanoparticles Allow Gene Delivery into Brain Tumors via Intravenous Administration
Authors: Lu Wei , Sun Qing , Wan Jin , She Zhenjue , Jiang Xin-Guo
Published: March 2023

Abstract
Patients with malignant gliomas have a poor prognosis because these tumors do not respond well to conventional treatments. Studies of glioma xenografts suggest that they may be amenable to gene therapy with cytotoxic genes, such as the proapoptotic Apo2 ligand/tumor necrosis factor–related apoptosis-inducing ligand (Apo2L/TRAIL). Gene therapy of gliomas ideally employs i.v. given vectors, thus excluding viral vectors as they cannot cross the brain microvascular endothelium or blood-brain barrier. Recently, we reported the synthesis of cationic albumin–conjugated pegylated nanoparticles (CBSA-NP) and showed their accumulation in mouse brain cells upon i.v. administration. In this study, plasmid pORF-hTRAIL (pDNA) was incorporated into CBSA-NP, and the resulting CBSA-NP-hTRAIL was evaluated as a nonviral vector for gene therapy of gliomas. Thirty minutes after transfection of C6 glioma cells, CBSA-NP-hTRAIL was internalized and mostly located in the cytoplasm, whereas NP-hTRAIL was entrapped in the endolysosomal compartment. At 6 and 48 hours after transfection, respectively, released pDNA was present in the nuclei and induced apoptosis. At 30 minutes after i.v. administration of CBSA-NP-hTRAIL to BALB/c mice bearing i.c. C6 gliomas, CBSA-NP-hTRAIL colocalized with glycoproteins in brain and tumor microvasculature and, via absorptive-mediated transcytosis, accumulated in tumor cells. At 24 and 48 hours after i.v. administration of CBSA-NP-hTRAIL, respectively, hTRAIL mRNA and protein were detected in normal brain and tumors. Furthermore, repeated i.v. injections of CBSA-NP-hTRAIL induced apoptosis in vivo and significantly delayed tumor growth. In summary, this study indicates that CBSA-NP-hTRAIL is a promising candidate for noninvasive gene therapy of malignant glioma. (Cancer Res 2006; 66(24): 11878-87)
Data from Tumor Necrosis Factor-α Is a Potent Endogenous Mutagen that Promotes Cellular Transformation
Authors: Yan Bin , Wang Huili , Rabbani Zahid N. , Zhao Yulin , Li Wenrong , Yuan Yuqing , Li Fang , Dewhirst Mark W. , Li Chuan-Yuan
Published: March 2023

Abstract
Tumor necrosis factor-α (TNF-α) is an important inflammation cytokine without known direct effect on DNA. In this study, we found that TNF-α can cause DNA damages through reactive oxygen species. The mutagenic effect of TNF-α is comparable with that of ionizing radiation. TNF-α treatment in cultured cells resulted in increased gene mutations, gene amplification, micronuclei formation, and chromosomal instability. Antioxidants significantly reduced TNF-α–induced genetic damage. TNF-α also induced oxidative stress and nucleotide damages in mouse tissues in vivo. Moreover, TNF-α treatment alone led to increased malignant transformation of mouse embryo fibroblasts, which could be partially suppressed by antioxidants. As TNF-α is involved in chronic inflammatory diseases, such as chronic hepatitis, ulcerative colitis, and chronic skin ulcers, and these diseases predispose the patients to cancer development, our results suggest a novel pathway through which TNF-α promotes cancer development through induction of gene mutations, in addition to the previously reported mechanisms, in which nuclear factor-κB activation was implicated. (Cancer Res 2006; 66(24): 11565-70)
Data from Inhibition of Epidermal Growth Factor Receptor Signaling Elevates 15-Hydroxyprostaglandin Dehydrogenase in Non–Small-Cell Lung Cancer
Authors: Yang Li , Amann Joseph M. , Kikuchi Takefumi , Porta Rut , Guix Marta , Gonzalez Adriana , Park Kyung-Ho , Billheimer Dean , Arteaga Carlos L. , Tai Hsin-Hsiung , DuBois Raymond , Carbone David P. , Johnson David H.
Published: March 2023

Abstract
Evidence indicates that the induction of cyclooxygenase-2 (COX-2) and high prostaglandin E2 (PGE2) levels contribute to the pathogenesis of non–small-cell lung cancer (NSCLC). In addition to overproduction by COX-2, PGE2 concentrations also depend upon the levels of the PGE2 catabolic enzyme 15-hydroxyprostaglandin dehydrogenase (15-PGDH). We find a dramatic down-regulation of PGDH protein in NSCLC cell lines and in resected human tumors when compared with matched normal lung. Affymetrix array analysis of 10 normal lung tissue samples and 49 resected lung tumors revealed a much lower expression of PGDH transcripts in all NSCLC histologic groups. In addition, treatment with the epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) erlotinib increased the expression of 15-PGDH in a subset of NSCLC cell lines. This effect may be due in part to an inhibition of the extracellular signal-regulated kinase (ERK) pathway as treatment with mitogen-activated protein kinase kinase (MEK) inhibitor U0126 mimics the erlotinib results. We show by quantitative reverse transcription-PCR that the transcript levels of ZEB1 and Slug transcriptional repressors are dramatically reduced in a responsive cell line upon EGFR and MEK/ERK inhibition. In addition, the Slug protein, but not ZEB1, binds to the PGDH promoter and represses transcription. As these repressors function by recruiting histone deacetylases to promoters, it is likely that PGDH is repressed by an epigenetic mechanism involving histone deacetylation, resulting in increased PGE2 activity in tumors. This effect is reversible in a subset of NSCLC upon treatment with an EGFR TKI. [Cancer Res 2007;67(12):5587–93]
Data from Subtractive Transcriptomics: Establishing Polarity Drives In vitro Human Endothelial Morphogenesis
Authors: Glesne David A. , Zhang Wen , Mandava Suneeta , Ursos Lyann , Buell Margaret E. , Makowski Lee , Rodi Diane J.
Published: March 2023

Abstract
Although investigations of mature normal and tumor-derived capillaries have resulted in characterization of these structures at the phenotypic level, less is known regarding the initial molecular cues for cellular assembly of endothelial cells into human capillaries. Here, we employ a novel combination of microenvironmental manipulation and microarray data filtration over narrowly delineated temporal data series to identify the morphogenesis component apart from the proliferation component, as pooled human microvascular-derived endothelial cells are induced to form capillary-like structures in vitro in a murine tumor-derived matrix. The 217 morphogenesis-specific genes identified using this subtractive transcriptomics approach are mostly independent of the angiogenic proteins currently used as therapeutic targets for aberrant angiogenesis. Quantitative real-time PCR was used to validate 20% of these transcripts. Immunofluorescent analysis of proliferating and tube-forming cells validates at the protein level the morphogenesis-specific expression pattern of 16 of the 217 gene products identified. The transcripts that are selectively up-regulated in tube-forming endothelial cells reveal a temporal expression pattern of genes primarily associated with intracellular trafficking, guided migration, cytoskeletal reorganization, cellular adhesion, and proliferation inhibition. These data show that a sequential up-regulation of genes that establish and maintain polarity occurs during migration and morphogenesis of in vitro human endothelial cells undergoing tubulogenesis; some of which may well be effective as novel antiangiogenic drug targets. (Cancer Res 2006; 66(8): 4030-40)
Data from Ultradeep Bisulfite Sequencing Analysis of DNA Methylation Patterns in Multiple Gene Promoters by 454 Sequencing
Authors: Taylor Kristen H. , Kramer Robin S. , Davis J. Wade , Guo Juyuan , Duff Deiter J. , Xu Dong , Caldwell Charles W. , Shi Huidong
Published: March 2023

Abstract
We developed a novel approach for conducting multisample, multigene, ultradeep bisulfite sequencing analysis of DNA methylation patterns in clinical samples. A massively parallel sequencing-by-synthesis method (454 sequencing) was used to directly sequence >100 bisulfite PCR products in a single sequencing run without subcloning. We showed the utility, robustness, and superiority of this approach by analyzing methylation in 25 gene-related CpG rich regions from >40 cases of primary cells, including normal peripheral blood lymphocytes, acute lymphoblastic leukemia (ALL), chronic lymphocytic leukemia (CLL), follicular lymphoma (FL), and mantle cell lymphoma (MCL). A total of 294,631 sequences was generated with an average read length of 131 bp. On average, >1,600 individual sequences were generated for each PCR amplicon far beyond the few clones (<20) typically analyzed by traditional bisulfite sequencing. Comprehensive analysis of CpG methylation patterns at a single DNA molecule level using clustering algorithms revealed differential methylation patterns between diseases. A significant increase in methylation was detected in ALL and FL samples compared with CLL and MCL. Furthermore, a progressive spreading of methylation was detected from the periphery toward the center of select CpG islands in the ALL and FL samples. The ultradeep sequencing also allowed simultaneous analysis of genetic and epigenetic data and revealed an association between a single nucleotide polymorphism and the methylation present in the LRP1B promoter. This new generation of methylome sequencing will provide digital profiles of aberrant DNA methylation for individual human cancers and offers a robust method for the epigenetic classification of tumor subtypes. [Cancer Res 2007;67(18):8511–8]
Data from Altered Expression of the Early Mitotic Checkpoint Protein, CHFR, in Breast Cancers: Implications for Tumor Suppression
Authors: Privette Lisa M. , González Maria E. , Ding Lei , Kleer Celina G. , Petty Elizabeth M.
Published: March 2023

Abstract
Checkpoint with FHA and Ring Finger (CHFR) is hypothesized to mediate a delay in cell cycle progression early in mitosis in response to microtubule stress, independent of the spindle assembly checkpoint. As a potential regulator of cell cycle progression, CHFR naturally becomes an interesting target for understanding cancer cells. In recent years, there has been increasing evidence supporting the role of CHFR as a tumor suppressor, most of which report loss of expression, occasionally due to promoter hypermethylation, in cancers compared with patient-matched normal tissues. We studied both a panel of breast cancer cell lines as well as primary tissue samples from breast cancer patients to investigate CHFR as a relevant tumor suppressor in breast cancer and to determine whether CHFR expression was associated with clinical and pathologic variables. We report that 41% of cell lines and 36% of patient samples showed low or negative CHFR protein expression or staining. In addition, lack of CHFR detection was associated with increased tumor size and weakly correlated with estrogen receptor–negative tumors from patients. To study the effects of low CHFR expression in vitro, we stably expressed a short hairpin RNA construct targeting CHFR in two lines of immortalized human mammary epithelial cells. Notably, decreased CHFR expression resulted in the acquisition of many phenotypes associated with malignant progression, including accelerated growth rates, higher mitotic index, enhanced invasiveness, increased motility, greater aneuploidy, and amplified colony formation in soft agar, further supporting the role of CHFR as a tumor suppressor in breast cancer. [Cancer Res 2007;67(13):6064–74]
Data from Fc Optimization of Therapeutic Antibodies Enhances Their Ability to Kill Tumor Cells In vitro and Controls Tumor Expansion In vivo via Low-Affinity Activating Fcγ Receptors
Authors: Stavenhagen Jeffrey B. , Gorlatov Sergey , Tuaillon Nadine , Rankin Christopher T. , Li Hua , Burke Stephen , Huang Ling , Johnson Syd , Bonvini Ezio , Koenig Scott
Published: March 2023

Abstract
Monoclonal antibodies (mAb) are widely used in the treatment of non-Hodgkin's lymphoma and autoimmune diseases. Although the mechanism of action in vivo is not always known, the therapeutic activity of several approved mAbs depends on the binding of the Fcγ regions to low-affinity Fcγ receptors (FcγR) expressed on effector cells. We did functional genetic screens to identify IgG1 Fc domains with improved binding to the low-affinity activating Fc receptor CD16A (FcγRIIIA) and reduced binding to the low-affinity inhibitory Fc receptor, CD32B (FcγRIIB). Identification of new amino acid residues important for FcγR binding guided the construction of an Fc domain that showed a dramatically enhanced CD16A binding and greater than a 100-fold improvement in antibody-dependent cell-mediated cytotoxicity. In a xenograft murine model of B-cell malignancy, the greatest enhancement of an Fc-optimized anti-human B-cell mAb was accounted for by improved binding to FcγRIV, a unique mouse activating FcγR that is expressed by monocytes and macrophages but not natural killer (NK) cells, consistent with experimental and clinical data suggesting that mononuclear phagocytes, effector cells expressing both activating and inhibitory FcγR, are critical mediators of B-cell depletion in vivo. By using mice transgenic for human CD16A, enhanced survival was observed due to expression of CD16A-158phe on monocytes and macrophages as well as on NK cells in these mice. The design of new generations of improved antibodies for immunotherapy should aim at Fc optimization to increase the engagement of activating FcγR present on the surface of tumor-infiltrating effector cell populations. [Cancer Res 2007;67(18):8882–90]
Data from Antitumor Activity of PR-171, a Novel Irreversible Inhibitor of the Proteasome
Authors: Demo Susan D. , Kirk Christopher J. , Aujay Monette A. , Buchholz Tonia J. , Dajee Maya , Ho Mark N. , Jiang Jing , Laidig Guy J. , Lewis Evan R. , Parlati Francesco , Shenk Kevin D. , Smyth Mark S. , Sun Congcong M. , Vallone Marcy K. , Woo Tina M. , Molineaux Christopher J. , Bennett Mark K.
Published: March 2023

Abstract
Clinical studies with bortezomib have validated the proteasome as a therapeutic target for the treatment of multiple myeloma and non-Hodgkin's lymphoma. However, significant toxicities have restricted the intensity of bortezomib dosing. Here we describe the antitumor activity of PR-171, a novel epoxyketone-based irreversible proteasome inhibitor that is currently in clinical development. In comparison to bortezomib, PR-171 exhibits equal potency but greater selectivity for the chymotrypsin-like activity of the proteasome. In cell culture, PR-171 is more cytotoxic than bortezomib following brief treatments that mimic the in vivo pharmacokinetics of both molecules. Hematologic tumor cells exhibit the greatest sensitivity to brief exposure, whereas solid tumor cells and nontransformed cell types are less sensitive to such treatments. Cellular consequences of PR-171 treatment include the accumulation of proteasome substrates and induction of cell cycle arrest and/or apoptosis. Administration of PR-171 to animals results in the dose-dependent inhibition of the chymotrypsin-like proteasome activity in all tissues examined with the exception of the brain. PR-171 is well tolerated when administered for either 2 or 5 consecutive days at doses resulting in >80% proteasome inhibition in blood and most tissues. In human tumor xenograft models, PR-171 mediates an antitumor response that is both dose and schedule dependent. The antitumor efficacy of PR-171 delivered on 2 consecutive days is stronger than that of bortezomib administered on its clinical dosing schedule. These studies show the tolerability, efficacy, and dosing flexibility of PR-171 and provide validation for the clinical testing of PR-171 in the treatment of hematologic malignancies using dose-intensive schedules. [Cancer Res 2007;67(13):6383–91]
Data from Enrichment of a Population of Mammary Gland Cells that Form Mammospheres and Have In vivo Repopulating Activity
Authors: Liao Mai-Jing , Zhang Cheng Cheng , Zhou Beiyan , Zimonjic Drazen B. , Mani Sendurai A. , Kaba Megan , Gifford Ann , Reinhardt Ferenc , Popescu Nicholas C. , Guo Wenjun , Eaton Elinor Ng , Lodish Harvey F. , Weinberg Robert A.
Published: March 2023

Abstract
The identification of mammary gland stem cells (MGSC) or progenitors is important for the study of normal breast development and tumorigenesis. Based on their immunophenotype, we have isolated a population of mouse mammary gland cells that are capable of forming “mammospheres” in vitro. Importantly, mammospheres are enriched for cells that regenerate an entire mammary gland on implantation into a mammary fat pad. We also undertook cytogenetic analyses of mammosphere-forming cells after prolonged culture, which provided preliminary insight into the genomic stability of these cells. Our identification of new cell surface markers for enriching mammosphere-initiating cells, including endoglin and prion protein, will facilitate the elucidation of the cell biology of MGSC. [Cancer Res 2007;67(17):8131–8]
Data from Melanocyte Expression of Survivin Promotes Development and Metastasis of UV-Induced Melanoma in HGF-Transgenic Mice
Authors: Thomas Joshua , Liu Tong , Cotter Murray A. , Florell Scott R. , Robinette Kyle , Hanks Adrianne N. , Grossman Douglas
Published: March 2023

Abstract
We previously found the apoptosis inhibitor Survivin to be expressed in melanocytic nevi and melanoma but not in normal melanocytes. To investigate the role of Survivin in melanoma development and progression, we examined the consequences of forced Survivin expression in melanocytes in vivo. Transgenic (Tg) mouse lines (Dct-Survivin) were generated with melanocyte-specific expression of Survivin, and melanocytes grown from Dct-Survivin mice expressed Survivin. Dct-Survivin melanocytes exhibited decreased susceptibility to UV-induced apoptosis but no difference in proliferative capacity compared with melanocytes derived from non-Tg littermates. Induction of nevi in Dct-Survivin and non-Tg mice by topical application of 7,12-dimethylbenz(a)anthracene did not reveal significant differences in lesion onset (median, 10 weeks) or density (4 lesions per mouse after 15 weeks). Dct-Survivin mice were bred with melanoma-prone MH19/HGF-B6 Tg mice, and all progeny expressing either individual, neither, or both (Survivin/HGF) transgenes were UV-treated as neonates and then monitored for 43 weeks. Melanocytes in neonatal Survivin+/HGF+ mouse skin were less susceptible to UV-induced apoptosis than those from Survivin−/HGF+ mice. Onset of melanocytic tumors was earlier (median, 18 versus 24 weeks; P = 0.01, log-rank test), and overall tumor density was greater (7.7 versus 5.2 tumors per mouse; P = 0.04) in Survivin+/HGF+ compared with Survivin−/HGF+ mice. Strikingly, melanomas arising in Survivin+/HGF+ mice showed a greater tendency for lymph node (35% versus 0%; P = 0.04) and lung (53% versus 22%) metastasis and lower rates of spontaneous apoptosis than those in Survivin−/HGF+ mice. These studies show a role for Survivin in promoting both early and late events of UV-induced melanoma development in vivo. [Cancer Res 2007;67(11):5172–8]
Data from Krüppel-Like Factor 8 Induces Epithelial to Mesenchymal Transition and Epithelial Cell Invasion
Authors: Wang Xianhui , Zheng Mingzhe , Liu Gang , Xia Weiya , McKeown-Longo Paula J. , Hung Mien-Chie , Zhao Jihe
Published: March 2023

Abstract
Tumor invasion and metastasis are the main causes of death from cancer. Epithelial to mesenchymal transition (EMT) is a determining step for a cancer cell to progress from a noninvasive to invasive state. Krüppel-like factor 8 (KLF8) plays a key role in oncogenic transformation and is highly overexpressed in several types of invasive human cancer, including breast cancer. To understand the role of KLF8 in regulating the progression of human breast cancer, we first established stable expression of KLF8 in an immortalized normal human breast epithelial cell line. We found that KLF8 strongly induced EMT and enhanced motility and invasiveness in the cells, by analyzing changes in cell morphology and epithelial and mesenchymal marker proteins, and using cell migration and Matrigel invasion assays. Chromatin immunoprecipitations (ChIP), oligonucleotide precipitations, and promoter-reporter assays showed that KLF8 directly bound and repressed the promoter of E-cadherin independent of E boxes in the promoter and Snail expression. Aberrant elevation of KLF8 expression is highly correlated with the decrease in E-cadherin expression in the invasive human breast cancer. Blocking KLF8 expression by RNA interference restored E-cadherin expression in the cancer cells and strongly inhibited the cell invasiveness. This work identifies KLF8 as a novel EMT-regulating transcription factor that opens a new avenue in EMT research and suggests an important role for KLF8 in human breast cancer invasion and metastasis. [Cancer Res 2007;67(15):7184–93]
Data from TIP30 Mutant Derived from Hepatocellular Carcinoma Specimens Promotes Growth of HepG2 Cells through Up-Regulation of N-cadherin
Authors: Jiang Chao , Pecha Jill , Hoshino Isamu , Ankrapp David , Xiao Hua
Published: March 2023

Abstract
TIP30 is a tumor suppressor whose expression is altered in human liver, prostate, lung, colon, and breast cancers. Mice lacking TIP30 spontaneously developed hepatocellular carcinomas (HCC) and other tumors at a higher incidence than wild-type mice. Somatic missense mutations in the TIP30 gene were identified in human HCC tissue specimens, which resulted in instability or abnormal cellular distribution of TIP30 protein in cells. Here, we show that TIP30 mutants are able to promote cell growth and invasion and inhibit cisplatin-induced apoptosis in the HCC cell line HepG2 negative for endogenous TIP30. Moreover, one of the TIP30 mutants can dramatically accelerate tumor formation in immunodeficient mice. Analysis of gene expression in HepG2 cells, ectopically expressing either wild-type TIP30 or mutant TIP30, by Affymetrix GeneChip array, real-time quantitative PCR, and Western blotting assays reveals that TIP30 mutants can alter expression of genes involved in the regulation of tumorigenesis. This includes up-regulation of expression of N-cadherin and c-MYC and down-regulation of expression of p53 and E-cadherin. N-cadherin knockdown with small interfering RNA in HepG2 cells expressing mutant TIP30 resulted in a profound reduction in cell viability. Taken together, our data indicate that somatic mutations in the TIP30 gene may abolish its native tumor-suppressor activity and gain oncogenic activities partially through up-regulation of N-cadherin, thereby potentiating the pathogenesis of HCC in patients. [Cancer Res 2007;67(8):1–9]
Data from Epidermal Growth Factor Receptors with Tyrosine Kinase Domain Mutations Exhibit Reduced Cbl Association, Poor Ubiquitylation, and Down-regulation but Are Efficiently Internalized
Authors: Padrón David , Sato Mitsuo , Shay Jerry W. , Gazdar Adi F. , Minna John D. , Roth Michael G.
Published: March 2023

Abstract
Some non–small cell lung cancers (NSCLC) with epidermal growth factor receptor (EGFR) tyrosine kinase domain mutations require altered signaling through the EGFR for cell survival and are exquisitely sensitive to tyrosine kinase inhibitors. EGFR down-regulation was impaired in two NSCLCs with EGFR tyrosine kinase domain mutations. The mutant receptors were poorly ubiquitylated and exhibited decreased association with the ubiquitin ligase Cbl. Overexpression of Cbl increased the degradation of EGFR. Treatment with geldanamycin, an inhibitor of the chaperone heat shock protein 90, also increased both wild-type and mutant EGFR degradation without affecting internalization. The down-regulation of the mutant EGFRs was still impaired when they were stably expressed in normal human bronchial epithelial cells. Thus, the mutations that altered signaling also decreased the interaction of EGFRs with the mechanisms responsible for endosomal sorting. [Cancer Res 2007;67(16):7695–702]
Data from Murine Cell Lines Derived from Pten Null Prostate Cancer Show the Critical Role of PTEN in Hormone Refractory Prostate Cancer Development
Authors: Jiao Jing , Wang Shunyou , Qiao Rong , Vivanco Igor , Watson Philip A. , Sawyers Charles L. , Wu Hong
Published: March 2023

Abstract
PTEN mutations are among the most frequent genetic alterations found in human prostate cancers. Our previous works suggest that although precancerous lesions were found in Pten heterozygous mice, cancer progression and metastasis only happened when both alleles of Pten were deleted. To understand the molecular mechanisms underlying the role of PTEN in prostate cancer control, we generated two pairs of isogenic, androgen receptor (AR)–positive prostate epithelial lines from intact conditional Pten knock-out mice that are either heterozygous (PTEN-P2 and -P8) or homozygous (PTEN-CaP2 and PTEN-CaP8) for Pten deletion. Further characterization of these cells showed that loss of the second allele of Pten leads to increased anchorage-independent growth in vitro and tumorigenesis in vivo without obvious structural or numerical chromosome changes based on SKY karyotyping analysis. Despite no prior exposure to hormone ablation therapy, Pten null cells are tumorigenic in both male and female severe combined immunodeficiency mice. Furthermore, knocking down PTEN can convert the androgen-dependent Myc-CaP cell into androgen independence, suggesting that PTEN intrinsically controls androgen responsiveness, a critical step in the development of hormone refractory prostate cancer. Importantly, knocking down AR by shRNA in Pten null cells reverses androgen-independent growth in vitro and partially inhibited tumorigenesis in vivo, indicating that PTEN-controlled prostate tumorigenesis is AR dependent. These cell lines will serve as useful tools for understanding signaling pathways controlled by PTEN and elucidating the molecular mechanisms involved in hormone refractory prostate cancer formation. [Cancer Res 2007;67(13):6083–91]
Data from Identification of Pax5 as a Target of MTA1 in B-Cell Lymphomas
Authors: Balasenthil Seetharaman , Gururaj Anupama E. , Talukder Amjad H. , Bagheri-Yarmand Rozita , Arrington Ty , Haas Brian J. , Braisted John C. , Kim Insun , Lee Norman H. , Kumar Rakesh
Published: March 2023

Abstract
Previously, we have shown that metastasis-associated protein 1 (MTA1) overexpression in transgenic mice was accompanied by high incidence of spontaneous B-cell lymphomas including diffuse large B-cell lymphomas (DLBCL). To understand the molecular basis of lymphoma in MTA1-transgenic (MTA1-TG) mice, we wished to identify a putative MTA1 target with a causal role in B-cell lymphogenesis. Using chromatin immunoprecipitation assays, we identified paired box gene 5 (Pax5), a molecule previously implicated in B-cell lymphogenesis, as a potential downstream effector of MTA1. Lymphomas from MTA1-TG mice also showed up-regulation of Pax5. We also found that MTA1 acetylated on Lys626 interacted with p300 histone acetyltransferase, and that acetylated MTA1 was recruited to the Pax5 promoter to stimulate Pax5 transcription. Global gene profiling identified down-regulation of a set of genes, including those downstream of Pax5 and directly implicated in the B-cell lymphogenesis. Significance of these murine studies was established by evidence showing a widespread up-regulation of both MTA1 and Pax5 in DLBCL from humans. These observations provide in vivo genetic evidence for a role of MTA1 in lymphomagenesis. [Cancer Res 2007;67(15):7132–8]
Data from Tissue-Specific Consequences of Cyclin D1 Overexpression in Prostate Cancer Progression
Authors: He Yue , Franco Omar E. , Jiang Ming , Williams Karin , Love Harold D. , Coleman Ilsa M. , Nelson Peter S. , Hayward Simon W.
Published: March 2023

Abstract
The cyclin D1 oncogene encodes the regulatory subunit of a holoenzyme that phosphorylates and inactivates the Rb protein and promotes progression through G1 to S phase of the cell cycle. Several prostate cancer cell lines and a subset of primary prostate cancer samples have increased cyclin D1 protein expression. However, the relationship between cyclin D1 expression and prostate tumor progression has yet to be clearly characterized. This study examined the effects of manipulating cyclin D1 expression in either human prostatic epithelial or stromal cells using a tissue recombination model. The data showed that overexpression of cyclin D1 in the initiated BPH-1 cell line increased cell proliferation rate but did not elicit tumorigenicity in vivo. However, overexpression of cyclin D1 in normal prostate fibroblasts (NPF) that were subsequently recombined with BPH-1 did induce malignant transformation of the epithelial cells. The present study also showed that recombination of BPH-1 + cyclin D1–overexpressing fibroblasts (NPFcyclin D1) resulted in permanent malignant transformation of epithelial cells (BPH-1NPF-cyclin D1 cells) similar to that seen with carcinoma-associated fibroblasts (CAF). Microarray analysis showed that the expression profiles between CAFs and NPFcyclin D1 cells were highly concordant including cyclin D1 up-regulation. These data indicated that the tumor-promoting activity of cyclin D1 may be tissue specific. [Cancer Res 2007;67(17):8188–97]
Data from Small Interfering RNA–Directed Reversal of Urokinase Plasminogen Activator Demethylation Inhibits Prostate Tumor Growth and Metastasis
Authors: Pulukuri Sai Murali Krishna , Rao Jasti S.
Published: March 2023

Abstract
Recent studies have shown that small interfering RNA (siRNA) silences genes at the transcriptional level in human cells. However, the therapeutic potential of siRNA-mediated transcriptional gene silencing remains unclear. Here, we show that siRNA targeted to the urokinase plasminogen activator (uPA) promoter induced epigenetic transcriptional silencing in human prostate cancer cells. This silencing resulted in a dramatic reduction of tumor cell invasion and angiogenesis in vitro. Furthermore, the results from a bioluminescence tumor/metastasis model showed that the silencing of uPA significantly inhibits prostate tumor growth and the incidence of lung metastasis. Our findings represent a potentially powerful new approach to not only epigenetic silencing of metastasis or growth-promoting genes as a cancer therapy, but also as a means to shed light on how aberrant de novo methylation during cancer progression might be targeted to specific sequences. [Cancer Res 2007;67(14):6637–46]
Data from Real-time Imaging of Tumor-Cell Shedding and Trafficking in Lymphatic Channels
Authors: Hayashi Katsuhiro , Jiang Ping , Yamauchi Kensuke , Yamamoto Norio , Tsuchiya Hiroyuki , Tomita Katsuro , Moossa A.R. , Bouvet Michael , Hoffman Robert M.
Published: March 2023

Abstract
In the present report, we show real-time imaging of cancer cell trafficking in lymphatic vessels. Cancer cells labeled with both green fluorescent protein (GFP) in the nucleus and red fluorescent protein (RFP) in the cytoplasm or with GFP only or RFP only were injected into the inguinal lymph node of nude mice. The labeled cancer cells trafficked through lymphatic vessels where they were imaged via a skin flap in real time at the cellular level until they entered the axillary lymph node. The bright fluorescence of the cancer cells and the real-time microscopic imaging capability of the Olympus OV100 small-animal imaging system enabled imaging of the trafficking cancer cells in the lymphatics. Using this imaging strategy, two different cancer cell lines, one expressing GFP and the other expressing RFP, were simultaneously injected in the inguinal lymph node. Fluorescence imaging readily distinguished the two color-coded cell lines and their different abilities to survive in the lymphatic system. Using this imaging technology, we also investigated the role of pressure on tumor-cell shedding into lymphatic vessels. Pressure was generated by placing 25- and 250-g weights for 10 s on the bottom surface of a tumor-bearing footpad. Tumor cell fragments, single cells, and emboli shed from the footpad tumor were easily distinguished with the labeled cells and OV100 imaging system. Increasing pressure on the tumor increased the numbers of shed cells, fragments, and emboli. Pressure also deformed the shed emboli, increasing their maximum major axis. Imaging lymphatic trafficking of cancer cells can reveal critical steps of lymph node metastasis. [Cancer Res 2007;67(17):8223–8]
Data from Pediatric KIT–Wild-Type and Platelet-Derived Growth Factor Receptor α–Wild-Type Gastrointestinal Stromal Tumors Share KIT Activation but not Mechanisms of Genetic Progression with Adult Gastrointestinal Stromal Tumors
Authors: Janeway Katherine A. , Liegl Bernadette , Harlow Amy , Le Claudia , Perez-Atayde Antonio , Kozakewich Harry , Corless Christopher L. , Heinrich Michael C. , Fletcher Jonathan A.
Published: March 2023

Abstract
Fewer than 15% of gastrointestinal stromal tumors (GIST) in pediatric patients harbor KIT or platelet-derived growth factor receptor α (PDGFRA) mutations in contrast to a mutation rate of 80% in adult GISTs. However, some therapeutic inhibitors of KIT have efficacy in pediatric GIST, suggesting that KIT may, nevertheless, play an important role in oncogenesis. In adult GIST, characteristic cytogenetic changes occur during progression to malignancy. A better understanding of mechanisms of genetic progression and KIT and PDGFRA transforming roles in pediatric GIST might facilitate treatment advances. KIT and PDGFRA mutation analysis was done in 27 pediatric GISTs. The activation status of KIT, PDGFRA, and downstream signaling intermediates was defined, and chromosomal aberrations were determined by single nucleotide polymorphism assays. Mutations in KIT or PDGFRA were identified in 11% of pediatric GISTs. KIT and the signaling intermediates AKT and mitogen-activated protein kinase were activated in pediatric GISTs. In particular, most pediatric KIT–wild-type GISTs displayed levels of KIT activation similar to levels in adult KIT-mutant GISTs. Pediatric KIT–wild-type GISTs lacked the typical cytogenetic deletions seen in adult KIT-mutant GISTs. Notably, most pediatric KIT–wild-type GISTs progress to malignancy without acquiring large-scale chromosomal aberrations, which is a phenomenon not reported previously in malignant solid tumors. KIT activation levels in pediatric KIT–wild-type GISTs are comparable with those in KIT-mutant GISTs. Therapies that inhibit KIT activation, or crucial KIT signaling intermediates, should be explored in pediatric KIT–wild-type GIST. [Cancer Res 2007;67(19):9084–8]
Data from Transgenic E2F1 Expression in the Mouse Brain Induces a Human-Like Bimodal Pattern of Tumors
Authors: Olson Melissa V. , Johnson David G. , Jiang Hong , Xu Jing , Alonso Marta M. , Aldape Kenneth D. , Fuller Gregory N. , Bekele B. Nebiyou , Yung W.K. Alfred , Gomez-Manzano Candelaria , Fueyo Juan
Published: March 2023

Abstract
The Rb/E2F pathway is deregulated in most human brain tumors, and the finding that loss of E2F1 reduced pituitary tumorigenesis in Rb+/− mice suggests that loss of pRb induces brain tumors by activating E2F1. We therefore investigated the role of E2F1 in the development and maintenance of brain cancer using a transgenic mouse model engineered to express E2F1 specifically within glial cells (GFAP-tgE2F1). GFAP-tgE2F1 mice developed a highly penetrant phenotype characterized by neurologic defects, and examination of the brains revealed the presence of brain tumors in 20% of these animals. Importantly, the distribution of tumors according to mouse age suggests the existence of a bimodal pattern of tumor development, forcing a comparison with the human disease. Mice, at an early age, with deregulated E2F1 show the formation of embryonal brain tumors such as medulloblastoma, choroid plexus carcinoma, and primary neuroectodermal tumor. Conversely, at an older age, mice escaping embryonal tumor formation present with malignant gliomas, which are typically identified in the human adult population. Thus, this study offers the first evidence for a global role of E2F1 in the formation and maintenance of multilineage brain tumors, irrefutably establishing E2F1 as an oncogene in the brain. [Cancer Res 2007;67(9):4005–9]
Data from Nonhomologous End Joining Is Essential for Cellular Resistance to the Novel Antitumor Agent, β-Lapachone
Authors: Bentle Melissa S. , Reinicke Kathryn E. , Dong Ying , Bey Erik A. , Boothman David A.
Published: March 2023

Abstract
Commonly used antitumor agents, such as DNA topoisomerase I/II poisons, kill cancer cells by creating nonrepairable DNA double-strand breaks (DSBs). To repair DSBs, error-free homologous recombination (HR), and/or error-prone nonhomologous end joining (NHEJ) are activated. These processes involve the phosphatidylinositol 3′-kinase–related kinase family of serine/threonine enzymes: ataxia telangiectasia mutated (ATM), ATM- and Rad3-related for HR, and DNA-dependent protein kinase catalytic subunit (DNA-PKcs) for NHEJ. Alterations in these repair processes can cause drug/radiation resistance and increased genomic instability. β-Lapachone (β-lap; also known as ARQ 501), currently in phase II clinical trials for the treatment of pancreatic cancer, causes a novel caspase- and p53-independent cell death in cancer cells overexpressing NAD(P)H:quinone oxidoreductase-1 (NQO1). NQO1 catalyzes a futile oxidoreduction of β-lap leading to reactive oxygen species generation, DNA breaks, γ-H2AX foci formation, and hyperactivation of poly(ADP-ribose) polymerase-1, which is required for cell death. Here, we report that β-lap exposure results in NQO1-dependent activation of the MRE11-Rad50-Nbs-1 complex. In addition, ATM serine 1981, DNA-PKcs threonine 2609, and Chk1 serine 345 phosphorylation were noted; indicative of simultaneous HR and NHEJ activation. However, inhibition of NHEJ, but not HR, by genetic or chemical means potentiated β-lap lethality. These studies give insight into the mechanism by which β-lap radiosensitizes cancer cells and suggest that NHEJ is a potent target for enhancing the therapeutic efficacy of β-lap alone or in combination with other agents in cancer cells that express elevated NQO1 levels. [Cancer Res 2007;67(14):6936–45]
Data from Glutathione Peroxidase 3, Deleted or Methylated in Prostate Cancer, Suppresses Prostate Cancer Growth and Metastasis
Authors: Yu Yan P. , Yu Guoying , Tseng George , Cieply Kathleen , Nelson Joel , Defrances Marie , Zarnegar Reza , Michalopoulos George , Luo Jian-Hua
Published: March 2023

Abstract
Glutathione peroxidase 3 is a selenium-dependent enzyme playing a critical role in detoxifying reactive oxidative species and maintaining the genetic integrity of mammalian cells. In this report, we found that the expression of glutathione peroxidase 3 (GPx3) was widely inactivated in prostate cancers. Complete inactivation of GPx3 correlates with a poor clinical outcome. Deletions (hemizygous and homozygous) of GPx3 gene are frequent in prostate cancer samples, occurring in 39% of the samples studied. The rate of methylation of the GPx3 exon 1 region in prostate cancer samples reaches 90%. Overexpression of GPx3 in prostate cancer cell lines induced the suppression of colony formation and anchorage-independent growth of PC3, LNCaP, and Du145 cells. PC3 cells overexpressing GPx3 reduced invasiveness in Matrigel transmigration analysis by an average of 2.7-fold. Xenografted PC3 cells expressing GPx3 showed reduction in tumor volume by 4.8-fold, elimination of metastasis (0/16 versus 7/16), and reduction of animal death (3/16 versus 16/16). The tumor suppressor activity of GPx3 seems to relate to its ability to suppress the expression of c-met. The present findings suggest that GPx3 is a novel tumor suppressor gene. [Cancer Res 2007;67(17):8043–50]
Data from Integrative Analysis of Genomic Aberrations Associated with Prostate Cancer Progression
Authors: Kim Jung H. , Dhanasekaran Saravana M. , Mehra Rohit , Tomlins Scott A. , Gu Wenjuan , Yu Jianjun , Kumar-Sinha Chandan , Cao Xuhong , Dash Atreya , Wang Lei , Ghosh Debashis , Shedden Kerby , Montie James E. , Rubin Mark A. , Pienta Kenneth J. , Shah Rajal B. , Chinnaiyan Arul M.
Published: March 2023

Abstract
Integrative analysis of genomic aberrations in the context of trancriptomic alterations will lead to a more comprehensive perspective on prostate cancer progression. Genome-wide copy number changes were monitored using array comparative genomic hybridization of laser-capture microdissected prostate cancer samples spanning stages of prostate cancer progression, including precursor lesions, clinically localized disease, and metastatic disease. A total of 62 specific cell populations from 38 patients were profiled. Minimal common regions (MCR) of alterations were defined for each sample type, and metastatic samples displayed the most number of alterations. Clinically localized prostate cancer samples with high Gleason grade resembled metastatic samples with respect to the size of altered regions and number of affected genes. A total of 9 out of 13 MCRs in the putative precursor lesion, high-grade prostatic intraepithelial neoplasia (PIN), showed an overlap with prostate cancer cases (amplifications in 3q29, 5q31.3-q32, 6q27, and 8q24.3 and deletions in 6q22.31, 16p12.2, 17q21.2, and 17q21.31), whereas postatrophic hyperplasia (PAH) did not exhibit this overlap. Interestingly, prostate cancers that do not overexpress ETS family members (i.e., gene fusion–negative prostate cancers) harbor differential aberrations in 1q23, 6q16, 6q21, 10q23, and 10q24. Integrative analysis with matched mRNA profiles identified genetic alterations in several proposed candidate genes implicated in prostate cancer progression. [Cancer Res 2007;67(17):8229–39]
Data from Side Population in Human Lung Cancer Cell Lines and Tumors Is Enriched with Stem-like Cancer Cells
Authors: Ho Maria M. , Ng Alvin V. , Lam Stephen , Hung Jaclyn Y.
Published: March 2023

Abstract
Stem cells have been isolated by their ability to efflux Hoechst 33342 dye and are referred to as the “side population” (SP). In this study, we used flow cytometry and Hoechst 33342 dye efflux assay to isolate and characterize SP cells from six human lung cancer cell lines (H460, H23, HTB-58, A549, H441, and H2170). Nonobese diabetic/severe combined immunodeficiency xenograft experiments showed that SP cells were enriched in tumor-initiating capability compared with non-SP cells. Matrigel invasion assay showed that SP cells also have higher potential for invasiveness. Further characterization of this SP phenotype revealed several stem cell properties. We found evidence for repopulating ability by SP to regenerate a population resembling the original population. SP displayed elevated expression of ABCG2 as well as other ATP-binding cassette transporters and showed resistance to multiple chemotherapeutic drugs. Human telomerase reverse transcriptase expression was higher in the SP, suggesting that this fraction may represent a reservoir with unlimited proliferative potential for generating cancer cells. mRNA levels of minichromosome maintenance (MCM) 7, a member of the MCM family of proteins critical to the DNA replication complex, were lower in SP cells, suggesting that a majority of the SP fraction was in the G0 quiescent state. Sixteen clinical lung cancer samples also displayed a smaller but persistent SP population. These findings indicate that SP is an enriched source of lung tumor–initiating cells with stem cell properties and may be an important target for effective therapy and a useful tool to investigate the tumorigenic process. [Cancer Res 2007;67(10):4827–33]
Data from In vivo Imaging of the Systemic Recruitment of Fibroblasts to the Angiogenic Rim of Ovarian Carcinoma Tumors
Authors: Granot Dorit , Addadi Yoseph , Kalchenko Vyacheslav , Harmelin Alon , Kunz-Schughart Leoni A. , Neeman Michal
Published: March 2023

Abstract
Tumor-associated stroma, in general, and tumor fibroblasts and myofibroblasts, in particular, play a role in tumor progression. We previously reported that myofibroblast infiltration into implanted ovarian carcinoma spheroids marked the exit of tumors from dormancy and that these cells contributed to vascular stabilization in ovarian tumors by expression of angiopoietin-1 and angiopoietin-2. Ex vivo labeling of fibroblasts with either magnetic resonance or optical probes rendered them detectable for in vivo imaging. Thus, magnetic resonance imaging (MRI) follow-up was feasible by biotin-bovine serum albumin-gadolinium diethylenetriaminepentaacetic acid or iron oxide particles, whereas labeling with near-IR and fluorescent vital stains enabled in vivo visualization by near-IR imaging and two-photon microscopy. Using this approach, we show here that prelabeled fibroblasts given i.p. to CD-1 nude mice can be followed in vivo by MRI and optical imaging over several days, revealing their extensive recruitment into the stroma of remote s.c. MLS human epithelial ovarian carcinoma tumors. Two-photon microscopy revealed the alignment of these invading fibroblasts in the outer rim of the tumor, colocalizing with the angiogenic neovasculature. Such angiogenic vessels remained confined to the stroma tracks within the tumor and did not penetrate the tumor nodules. These results provide dynamic evidence for the role of tumor fibroblasts in maintenance of functional tumor vasculature and offer means for image-guided targeting of these abundant stroma cells to the tumor as a possible mechanism for cellular cancer therapy. [Cancer Res 2007;67(19):9180–9]
Data from Distinct ErbB-2–Coupled Signaling Pathways Promote Mammary Tumors with Unique Pathologic and Transcriptional Profiles
Authors: Schade Babette , Lam Sonya H.L. , Cernea Daniela , Sanguin-Gendreau Virginie , Cardiff Robert D. , Jung Boonim L. , Hallett Michael , Muller William J.
Published: March 2023

Abstract
ErbB-2 overexpression and amplification occurs in 15% to 30% of human invasive breast carcinomas associated with poor clinical prognosis. Previously, we have shown that four ErbB-2/Neu tyrosine-autophosphorylation sites within the cytoplasmic tail of the receptor recruit distinct adaptor proteins and are sufficient to mediate transforming signals in vitro. Two of these sites, representing the growth factor receptor binding protein 2 (Grb2; Neu-YB) and the Src homology and collagen (Shc; Neu-YD) binding sites, can induce mammary tumorigenesis and metastasis. Here, we show that transgenic mice bearing the two other ErbB-2 autophosphorylation sites (Neu-YC and Neu-YE) develop metastatic mammary tumors. A detailed comparison of biological profiles among all Neu mutant mouse models revealed that Neu-YC, Neu-YD, and Neu-YE mammary tumors shared similar pathologic and transcriptional features. By contrast, the Neu-YB mouse model displayed a unique pathology with a high metastatic potential that correlates with a distinct transcriptional profile, including genes that promote malignant tumor progression such as metalloproteinases and chemokines. Furthermore, Neu-YB tumor epithelial cells showed abundant intracellular protein level of the chemokine CXCL12/SDF-1α, which may reflect the aggressive nature of this Neu mutant mouse model. Taken together, these findings indicate that activation of distinct Neu-coupled signaling pathways has an important impact on the biological behavior of Neu-induced tumors. [Cancer Res 2007;67(16):7579–88]