bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Fibroblast Hepatocyte Growth Factor Promotes Invasion of Human Mammary Ductal Carcinoma In situ
Authors: Jedeszko Christopher , Victor Bernadette C. , Podgorski Izabela , Sloane Bonnie F.
Published: March 2023

Abstract
Stromal-derived hepatocyte growth factor (HGF) acting through its specific proto-oncogene receptor c-Met has been suggested to play a paracrine role in the regulation of tumor cell migration and invasion. The transition from preinvasive ductal carcinoma in situ (DCIS) to invasive breast carcinoma is marked by infiltration of stromal fibroblasts and the loss of basement membrane. We hypothesized that HGF produced by the infiltrating fibroblasts may alter proteolytic pathways in DCIS cells, and, to study this hypothesis, established three-dimensional reconstituted basement membrane overlay cocultures with two human DCIS cell lines, MCF10.DCIS and SUM102. Both cell lines formed large dysplastic structures in three-dimensional cultures that resembled DCIS in vivo and occasionally developed invasive outgrowths. In coculture with HGF-secreting mammary fibroblasts, the percentage of DCIS structures with invasive outgrowths was increased. Activation of c-Met with conditioned medium from HGF-secreting fibroblasts or with recombinant HGF increased the percentage of DCIS structures with invasive outgrowths, their degradation of collagen IV, and their secretion of urokinase-type plasminogen activator and its receptor. In agreement with the in vitro findings, coinjection with HGF-secreting fibroblasts increased invasiveness of MCF10.DCIS xenografts in severe combined immunodeficient mice. Our study shows that paracrine HGF/c-Met signaling between fibroblasts and preinvasive DCIS cells enhances the transition to invasive carcinomas and suggests that three-dimensional cocultures are appropriate models for testing therapeutics that target tumor microenvironment-enhanced invasiveness. [Cancer Res 2009;69(23):9148–55]
Data from Methylation-Mediated Repression of GADD45α in Prostate Cancer and Its Role as a Potential Therapeutic Target
Authors: Ramachandran Kavitha , Gopisetty Gopal , Gordian Edna , Navarro Loida , Hader Christiane , Reis Isildinha M. , Schulz Wolfgang A. , Singal Rakesh
Published: March 2023

Abstract
Defects in apoptotic pathway contribute to uncontrolled proliferation of cancer cells and confer resistance to chemotherapy. Growth arrest and DNA damage inducible, alpha (GADD45α) is up-regulated on docetaxel treatment and may contribute to docetaxel-mediated cytotoxicity. We examined the mechanism of regulation of GADD45α in prostate cancer cells and the effect of its up-regulation on sensitivity to docetaxel chemotherapy. Expression of GADD45α in PC3 cells was higher than that in Du145 and LNCaP cells (17- and 12-fold, respectively; P < 0.05). Although the proximal promoter region was unmethylated in all three cell lines, methylation of a 4 CpG region upstream of the proximal promoter correlated inversely with gene expression levels. Methylation was reversed by treatment of Du145 and LNCaP cells with DNA methyltransferase inhibitors, leading to reactivation of GADD45α expression in these cells. The 5′ 4 CpG region was also frequently methylated in prostate cancer tissues. Methylation of this region correlated inversely with gene expression in prostate cancer and benign prostate tissues. The methyl binding protein MeCP2 was associated with the methylated 4 CpGs in Du145 cells, and knockdown of MeCP2 in these cells (Du145 MeCP2−) led to a significantly increased expression of GADD45α (3-fold; P = 0.035) without affecting the methylation status of the gene. Enhanced sensitivity to docetaxel was observed by up-regulation of GADD45α in Du145 cells by recombinant expression of GADD45α or pretreatment with 5-azacytidine. Our results show that GADD45α is epigenetically repressed and is a potential target for treatment of prostate cancer. [Cancer Res 2009;69(4):1527–35]
Data from Ligand-Dependent Platelet-Derived Growth Factor Receptor (PDGFR)-α Activation Sensitizes Rare Lung Cancer and Sarcoma Cells to PDGFR Kinase Inhibitors
Authors: McDermott Ultan , Ames Rachel Y. , Iafrate A. John , Maheswaran Shyamala , Stubbs Hannah , Greninger Patricia , McCutcheon Kaitlin , Milano Randy , Tam Angela , Lee Diana Y. , Lucien Laury , Brannigan Brian W. , Ulkus Lindsey E. , Ma Xiao-Jun , Erlander Mark G. , Haber Daniel A. , Sharma Sreenath V. , Settleman Jeffrey
Published: March 2023

Abstract
Platelet-derived growth factor (PDGF) receptors (PDGFR) and their ligands play critical roles in several human malignancies. Sunitinib is a clinically approved multitargeted tyrosine kinase inhibitor that inhibits vascular endothelial growth factor receptor, c-KIT, and PDGFR, and has shown clinical activity in various solid tumors. Activation of PDGFR signaling has been described in gastrointestinal stromal tumors (PDGFRA mutations) as well as in chronic myeloid leukemia (BCR-PDGFRA translocation), and sunitinib can yield clinical benefit in both settings. However, the discovery of PDGFR activating mutations or gene rearrangements in other tumor types could reveal additional patient populations who might benefit from treatment with anti-PDGFR therapies, such as sunitinib. Using a high-throughput cancer cell line screening platform, we found that only 2 of 637 tested human tumor-derived cell lines show significant sensitivity to single-agent sunitinib exposure. These two cell lines [a non–small-cell lung cancer (NSCLC) and a rhabdomyosarcoma] showed expression of highly phosphorylated PDGFRA. In the sunitinib-sensitive adenosquamous NSCLC cell line, PDGFRA expression was associated with focal PFGRA gene amplification, which was similarly detected in a small fraction of squamous cell NSCLC primary tumor specimens. Moreover, in this NSCLC cell line, focal amplification of the gene encoding the PDGFR ligand PDGFC was also detected, and silencing PDGFRA or PDGFC expression by RNA interference inhibited proliferation. A similar codependency on PDGFRA and PDGFC was observed in the sunitinib-sensitive rhabdomyosarcoma cell line. These findings suggest that, in addition to gastrointestinal stromal tumors, rare tumors that show PDGFC-mediated PDGFRA activation may also be clinically responsive to pharmacologic PDGFRA or PDGFC inhibition. [Cancer Res 2009;69(9):3937–46]
Data from Reprogramming T Lymphocytes for Melanoma Adoptive Immunotherapy by T-Cell Receptor Gene Transfer with Lentiviral Vectors
Authors: Bobisse Sara , Rondina Maria , Merlo Anna , Tisato Veronica , Mandruzzato Susanna , Amendola Mario , Naldini Luigi , Willemsen Ralph A. , Debets Reno , Zanovello Paola , Rosato Antonio
Published: March 2023

Abstract
T-cell receptor (TCR) gene transfer for cancer immunotherapy is limited by the availability of large numbers of tumor-specific T cells. TCR α and β chains were isolated from a highly lytic HLA-A2–restricted cytotoxic T lymphocyte (CTL) clone recognizing the melanoma-associated Melan-A/MART-1 antigen and inserted into a lentiviral vector carrying a bidirectional promoter capable of robust and coordinated expression of the two transgenes. Lentiviral vector–based gene delivery systems have shown increased transfer efficiency and transgene expression compared with the widely used γ-retroviral vectors. This vector performed more efficiently than a γ-retrovirus–based vector containing the same expression cassette, resulting in a T-cell population with 60% to 80% of transgenic TCR expression with mainly CD8+ intermediate effector phenotype. Transgenic T cells specifically produced cytokine in response to and killed antigen-expressing melanoma cells, retained an overlapping functional avidity in comparison with the TCR donor CTL clone, and exerted significant therapeutic effects in vivo upon adoptive transfer in melanoma-bearing severe combined immunodeficient mice. Optical imaging showed their accumulation in the tumor site. Overall, our results indicate that lentiviral vectors represent a valid tool for stable and high-intensity expression of transgenic TCR and support clinical exploitation of this approach for therapeutic application. [Cancer Res 2009;69(24):9385–94]
Data from Heat Shock Factor 1–Mediated Aneuploidy Requires a Defective Function of p53
Authors: Kim Eun-Ho , Lee Yoon-Jin , Bae Sangwoo , Lee Jae Seon , Kim Joon , Lee Yun-Sil
Published: March 2023

Abstract
Because heat shock factor 1 (HSF1) phosphorylation by Plk1 has been previously reported to be involved in mitotic regulation and p53 function may be involved in this mitotic regulation, we have further examined HSF1 functions in mitotic regulation according to p53 status. Nocodazole-mediated aneuploidy was increased in p53-defective (p53Mut) cells; however, it was not increased in p53 wild-type (p53WT) cells. Phosphorylation of HSF1 at Ser216 was increased in p53Mut cells with increased stability of securin and cyclin B1 in mitosis compared with p53WT cells. The interaction of p53 with Plk1 that was shown in p53WT cells and that induced normal mitotic checkpoint function was not observed in p53Mut cells; instead, the binding of HSF1 with Plk1 and HSF1 phosphorylation at Ser216 were seen in p53Mut cells, which resulted in increased aneuploidy production. Moreover, the interaction affinity of Cdc20 with Mad2 was inhibited in p53Mut cells, whereas the interaction between Cdc20 and HSF1 was increased. From the data, it was suggested that HSF1-mediated aneuploidy was more facilitated in p53-defective cells, indicating the importance of novel mechanisms for p53 function in HSF1-mediated mitotic regulation and genomic instability. [Cancer Res 2009;69(24):9404–12]
Data from FMS-Like Tyrosine Kinase 3–Internal Tandem Duplication Tyrosine Kinase Inhibitors Display a Nonoverlapping Profile of Resistance Mutations In vitro
Authors: von Bubnoff Nikolas , Engh Richard A. , Åberg Espen , Sänger Jana , Peschel Christian , Duyster Justus
Published: March 2023

Abstract
FMS-like tyrosine kinase 3 (FLT3) inhibitors have shown activity in the treatment of acute myelogenous leukemia (AML). Secondary mutations in target kinases can cause clinical resistance to therapeutic kinase inhibition. We have previously shown that sensitivity toward tyrosine kinase inhibitors varies between different activating FLT3 mutations. We therefore intended to determine whether different FLT3 inhibitors would produce distinct profiles of secondary, FLT3 resistance mutations. Using a cell-based screening approach, we generated FLT3–internal tandem duplication (ITD)–expressing cell lines resistant to the FLT3 inhibitors SU5614, PKC412, and sorafenib. Interestingly, the profile of resistance mutations emerging with SU5614 was limited to exchanges in the second part of the kinase domain (TK2) with exchanges of D835 predominating. In contrast, PKC412 exclusively produced mutations within tyrosine kinase domain 1 (TK1) at position N676. A mutation at N676 recently has been reported in a case of PKC412-resistant AML. TK1 mutations exhibited a differential response to SU5614, sorafenib, and sunitinib but strongly impaired response to PKC412. TK2 exchanges identified with SU5614 were sensitive to PKC412, sunitinib, or sorafenib, with the exception of Y842D, which caused a strong resistance to sorafenib. Of note, sorafenib also produced a highly distinct profile of resistance mutations with no overlap to SU5614 or PKC412, including F691L in TK1 and exchanges at position Y842 of TK2. Thus, different FLT3 kinase inhibitors generate distinct, nonoverlapping resistance profiles. This is in contrast to Bcr-Abl kinase inhibitors such as imatinib, nilotinib, and dasatinib, which display overlapping resistance profiles. Therefore, combinations of FLT3 inhibitors may be useful to prevent FLT3 resistance mutations in the setting of FLT3-ITD–positive AML. [Cancer Res 2009;69(7):3032–41]
Data from Inhibiting the Cyclin-Dependent Kinase CDK5 Blocks Pancreatic Cancer Formation and Progression through the Suppression of Ras-Ral Signaling
Authors: Feldmann Georg , Mishra Anjali , Hong Seung-Mo , Bisht Savita , Strock Christopher J. , Ball Douglas W. , Goggins Michael , Maitra Anirban , Nelkin Barry D.
Published: March 2023

Abstract
Cyclin-dependent kinase 5 (CDK5), a neuronal kinase that functions in migration, has been found to be activated in some human cancers in which it has been implicated in promoting metastasis. In this study, we investigated the role of CDK5 in pancreatic cancers in which metastatic disease is most common at diagnosis. CDK5 was widely active in pancreatic cancer cells. Functional ablation significantly inhibited invasion, migration, and anchorage-independent growth in vitro, and orthotopic tumor formation and systemic metastases in vivo. CDK5 blockade resulted in the profound inhibition of Ras signaling through its critical effectors RalA and RalB. Conversely, restoring Ral function rescued the effects of CDK5 inhibition in pancreatic cancer cells. Our findings identify CDK5 as a pharmacologically tractable target to degrade Ras signaling in pancreatic cancer. Cancer Res; 70(11); 4460–9. ©2010 AACR.
Data from Disruption of the E2 Gene Is a Common and Early Event in the Natural History of Cervical Human Papillomavirus Infection: A Longitudinal Cohort Study
Authors: Collins Stuart I. , Constandinou-Williams Christothea , Wen Kaisheng , Young Lawrence S. , Roberts Sally , Murray Paul G. , Woodman Ciaran B.J.
Published: March 2023

Abstract
Integration of high-risk human papillomavirus (HPV) types into the host-cell genome disrupts the HPV regulatory E2 protein, resulting in a loss of negative feedback control of viral oncogene expression; this disruption has been considered a critical event in the pathogenesis of cervical neoplasia, and a potential biomarker of progressive disease. However, using serial samples taken from a cohort of young women who were recruited soon after they first had sexual intercourse, we show that disruption of the E2 gene is a common and early event in the natural history of incident cervical HPV infections. The E2 gene was significantly more likely to be disrupted in women who tested positive for HPV18 in their baseline sample than in those who tested positive for HPV16 [26% versus 58%; relative risk, 2.26; 95% confidence interval (CI), 1.38–3.71; χ2, 9.23; 1 degree of freedom (df); P = 0.002]. Among women with an intact E2 gene in their baseline sample, the median time to first detection of E2 disruption was also shorter for those who tested positive for HPV18 than HPV16 (5.7 versus 10.9 months; hazards ratio, 1.93; 95% CI, 0.84–4.44; χ2, 2.49; 1 df; P = 0.11). This tendency for HPV18 to integrate early, coupled with the substantial reduction in viral load in HPV18-positive samples in which E2 is disrupted, may explain why HPV18-associated disease is often reported to be characterized by minor cytologic changes, which underestimate the severity of the underlying histologic abnormality. [Cancer Res 2009;69(9):3828–32]
Data from TGF-β1 + EGF-Initiated Invasive Potential in Transformed Human Keratinocytes Is Coupled to a Plasmin/MMP-10/MMP-1–Dependent Collagen Remodeling Axis: Role for PAI-1
Authors: Wilkins-Port Cynthia E. , Ye Qunhui , Mazurkiewicz Joseph E. , Higgins Paul J.
Published: March 2023

Abstract
The phenotypic switching called epithelial-to-mesenchymal transition is frequently associated with epithelial tumor cell progression from a comparatively benign to an aggressive, invasive malignancy. Coincident with the emergence of such cellular plasticity is an altered response to transforming growth factor-β (TGF-β) as well as epidermal growth factor (EGF) receptor amplification. TGF-β in the tumor microenvironment promotes invasive traits largely through reprogramming gene expression, which paradoxically supports matrix-disruptive as well as stabilizing processes. ras-transformed HaCaT II-4 keratinocytes undergo phenotypic changes typical of epithelial-to-mesenchymal transition, acquire a collagenolytic phenotype, and effectively invade collagen type 1 gels as a consequence of TGF-β1 + EGF stimulation in a three-dimensional physiologically relevant model system that monitors collagen remodeling. Enhanced collagen degradation was coupled to a significant increase in matrix metalloproteinase (MMP)-10 expression and involved a proteolytic axis composed of plasmin, MMP-10, and MMP-1. Neutralization of any one component in this cascade inhibited collagen gel lysis. Similarly, addition of plasminogen activator inhibitor type 1 (SERPINE1) blocked collagen degradation as well as the conversion of both proMMP-10 and proMMP-1 to their catalytically active forms. This study therefore identifies an important mechanism in TGF-β1 + EGF-initiated collagen remodeling by transformed human keratinocytes and proposes a crucial upstream role for plasminogen activator inhibitor type 1–dependent regulation in this event. [Cancer Res 2009;69(9):4081–91]
Data from Tripeptidyl Peptidase II Plays a Role in the Radiation Response of Selected Primary Cell Types but not Based on Nuclear Translocation and p53 Stabilization
Authors: Firat Elke , Tsurumi Chizuko , Gaedicke Simone , Huai Jisen , Niedermann Gabriele
Published: March 2023

Abstract
The giant cytosolic protease tripeptidyl peptidase II (TPPII) was recently proposed to play a role in the DNA damage response. Shown were nuclear translocation of TPPII after γ-irradiation, lack of radiation-induced p53 stabilization in TPPII-siRNA–treated cells, and complete tumor regression in mice after γ-irradiation when combined with TPPII-siRNA silencing or a protease inhibitor reported to inhibit TPPII. This suggested that TPPII could be a novel target for tumor radiosensitization and prompted us to study radiation responses using TPPII-knockout mice. Neither the sensitivity to total body irradiation nor the radiosensitivity of resting lymphoid cells, which both strongly depend on p53, was altered in the absence of TPPII. Functional integrity of p53 in TPPII-knockout cells is further shown by a proper G1 arrest and by the accumulation of p53 and its transcriptional targets, p21, Bax, and Fas, on γ-irradiation. Furthermore, we could not confirm radiation-induced nuclear translocation of TPPII. Nevertheless, after γ-irradiation, we found slightly increased mitotic catastrophe of TPPII-deficient primary fibroblasts and increased apoptosis of TPPII-deficient activated CD8+ T cells. The latter was accompanied by delayed resolution of the DNA double-strand break marker γH2AX. This could, however, be due to increased apoptotic DNA damage rather than reduced DNA damage repair. Our data do not confirm a role for TPPII in the DNA damage response based on nuclear TPPII translocation and p53 stabilization but nevertheless do show increased radiation-induced cell death of selected nontransformed cell types in the absence of the TPPII protease. [Cancer Res 2009;69(8):3325–31]
Data from Prognostic Significance of Growth Kinetics in Newly Diagnosed Glioblastomas Revealed by Combining Serial Imaging with a Novel Biomathematical Model
Authors: Wang Christina H. , Rockhill Jason K. , Mrugala Maciej , Peacock Danielle L. , Lai Albert , Jusenius Katy , Wardlaw Joanna M. , Cloughesy Timothy , Spence Alexander M. , Rockne Russ , Alvord Ellsworth C. , Swanson Kristin R.
Published: March 2023

Abstract
Glioblastomas are the most aggressive primary brain tumors, characterized by their rapid proliferation and diffuse infiltration of the brain tissue. Survival patterns in patients with glioblastoma have been associated with a number of clinicopathologic factors including age and neurologic status, yet a significant quantitative link to in vivo growth kinetics of each glioma has remained elusive. Exploiting a recently developed tool for quantifying glioma net proliferation and invasion rates in individual patients using routinely available magnetic resonance images (MRI), we propose to link these patient-specific kinetic rates of biological aggressiveness to prognostic significance. Using our biologically based mathematical model for glioma growth and invasion, examination of serial pretreatment MRIs of 32 glioblastoma patients allowed quantification of these rates for each patient's tumor. Survival analyses revealed that even when controlling for standard clinical parameters (e.g., age and Karnofsky performance status), these model-defined parameters quantifying biological aggressiveness (net proliferation and invasion rates) were significantly associated with prognosis. One hypothesis generated was that the ratio of the actual survival time after whatever therapies were used to the duration of survival predicted (by the model) without any therapy would provide a therapeutic response index (TRI) of the overall effectiveness of the therapies. The TRI may provide important information, not otherwise available, about the effectiveness of the treatments in individual patients. To our knowledge, this is the first report indicating that dynamic insight from routinely obtained pretreatment imaging may be quantitatively useful in characterizing the survival of individual patients with glioblastoma. Such a hybrid tool bridging mathematical modeling and clinical imaging may allow for stratifying patients for clinical studies relative to their pretreatment biological aggressiveness. [Cancer Res 2009;69(23):9133–40]
Data from Microenvironmental Independence Associated with Tumor Progression
Authors: Anderson Alexander R.A. , Hassanein Mohamed , Branch Kevin M. , Lu Jenny , Lobdell Nichole A. , Maier Julie , Basanta David , Weidow Brandy , Narasanna Archana , Arteaga Carlos L. , Reynolds Albert B. , Quaranta Vito , Estrada Lourdes , Weaver Alissa M.
Published: March 2023

Abstract
Tumor-microenvironment interactions are increasingly recognized to influence tumor progression. To understand the competitive dynamics of tumor cells in diverse microenvironments, we experimentally parameterized a hybrid discrete-continuum mathematical model with phenotypic trait data from a set of related mammary cell lines with normal, transformed, or tumorigenic properties. Surprisingly, in a resource-rich microenvironment, with few limitations on proliferation or migration, transformed (but not tumorigenic) cells were most successful and outcompeted other cell types in heterogeneous tumor simulations. Conversely, constrained microenvironments with limitations on space and/or growth factors gave a selective advantage to phenotypes derived from tumorigenic cell lines. Analysis of the relative performance of each phenotype in constrained versus unconstrained microenvironments revealed that, although all cell types grew more slowly in resource-constrained microenvironments, the most aggressive cells were least affected by microenvironmental constraints. A game theory model testing the relationship between microenvironment resource availability and competitive cellular dynamics supports the concept that microenvironmental independence is an advantageous cellular trait in resource-limited microenvironments. [Cancer Res 2009;69(22):8797–806]
Data from Cyclin D1/Cyclin-Dependent Kinase 4 Interacts with Filamin A and Affects the Migration and Invasion Potential of Breast Cancer Cells
Authors: Zhong Zhijiu , Yeow Wen-Shuz , Zou Chunhua , Wassell Richard , Wang Chenguang , Pestell Richard G. , Quong Judy N. , Quong Andrew A.
Published: March 2023

Abstract
Cyclin D1 belongs to a family of proteins that regulate progression through the G1-S phase of the cell cycle by binding to cyclin-dependent kinase (cdk)-4 to phosphorylate the retinoblastoma protein and release E2F transcription factors for progression through cell cycle. Several cancers, including breast, colon, and prostate, overexpress the cyclin D1 gene. However, the correlation of cyclin D1 overexpression with E2F target gene regulation or of cdk-dependent cyclin D1 activity with tumor development has not been identified. This suggests that the role of cyclin D1 in oncogenesis may be independent of its function as a cell cycle regulator. One such function is the role of cyclin D1 in cell adhesion and motility. Filamin A (FLNa), a member of the actin-binding filamin protein family, regulates signaling events involved in cell motility and invasion. FLNa has also been associated with a variety of cancers including lung cancer, prostate cancer, melanoma, human bladder cancer, and neuroblastoma. We hypothesized that elevated cyclin D1 facilitates motility in the invasive MDA-MB-231 breast cancer cell line. We show that MDA-MB-231 motility is affected by disturbing cyclin D1 levels or cyclin D1-cdk4/6 kinase activity. Using mass spectrometry, we find that cyclin D1 and FLNa coimmunoprecipitate and that lower levels of cyclin D1 are associated with decreased phosphorylation of FLNa at Ser2152 and Ser1459. We also identify many proteins related to cytoskeletal function, biomolecular synthesis, organelle biogenesis, and calcium regulation whose levels of expression change concomitant with decreased cell motility induced by decreased cyclin D1 and cyclin D1-cdk4/6 activities. Cancer Res; 70(5); 2105–14
Data from Hypoxia-Regulated Delta-like 1 Homologue Enhances Cancer Cell Stemness and Tumorigenicity
Authors: Kim Yuri , Lin Qun , Zelterman Daniel , Yun Zhong
Published: March 2023

Abstract
Reduced oxygenation, or hypoxia, inhibits differentiation and facilitates stem cell maintenance. Hypoxia commonly occurs in solid tumors and promotes malignant progression. Hypoxic tumors are aggressive and exhibit stem cell–like characteristics. It remains unclear, however, whether and how hypoxia regulates cancer cell differentiation and maintains cancer cell stemness. Here, we show that hypoxia increases the expression of the stem cell gene DLK1, or delta-like 1 homologue (Drosophila), in neuronal tumor cells. Inhibition of DLK1 enhances spontaneous differentiation, decreases clonogenicity, and reduces in vivo tumor growth. Overexpression of DLK1 inhibits differentiation and enhances tumorigenic potentials. We further show that the DLK1 cytoplasmic domain, especially Tyrosine339 and Serine355, is required for maintaining both clonogenicity and tumorigenicity. Because elevated DLK1 expression is found in many tumor types, our observations suggest that hypoxia and DLK1 may constitute an important stem cell pathway for the regulation of cancer stem cell–like functionality and tumorigenicity. [Cancer Res 2009;69(24):9271–80]
Data from Absence of Both Cytochrome P450 3A and P-glycoprotein Dramatically Increases Docetaxel Oral Bioavailability and Risk of Intestinal Toxicity
Authors: van Waterschoot Robert A.B. , Lagas Jurjen S. , Wagenaar Els , van der Kruijssen Cornelia M.M. , van Herwaarden Antonius E. , Song Ji-Ying , Rooswinkel Rogier W. , van Tellingen Olaf , Rosing Hilde , Beijnen Jos H. , Schinkel Alfred H.
Published: March 2023

Abstract
Docetaxel is one of the most widely used anticancer drugs. A major problem with docetaxel treatment, however, is the considerable interpatient variability in docetaxel exposure. Another disadvantage of the drug is that it has a very low oral bioavailability and can therefore only be administered i.v. The drug-metabolizing enzyme cytochrome P450 3A (CYP3A) and the drug transporter P-glycoprotein (P-gp; MDR1) are considered to be major determinants of docetaxel pharmacokinetics. It has been hypothesized that CYP3A and P-gp work synergistically in limiting the systemic exposure to many orally ingested drugs. However, it has been difficult to examine this interplay in vivo. We therefore generated mice lacking all CYP3A and P-gp genes. Although missing two primary detoxification systems, Cyp3a/Mdr1a/1b−/− mice are viable, fertile, and without spontaneous abnormalities. When orally challenged with docetaxel, a disproportionate (>70-fold) increase in systemic exposure was observed compared with the increases in single Cyp3a−/− (12-fold) or Mdr1a/1b−/− (3-fold) mice. Unexpectedly, although CYP3A and P-gp collaborated extremely efficiently in lowering docetaxel exposure, their individual efficacy was not dependent on activity of the other protein. On reflection, this absence of functional synergism makes biological sense, as synergism would conflict with a robust detoxification defense. Importantly, the disproportionate increase in docetaxel exposure in Cyp3a/Mdr1a/1b−/− mice resulted in dramatically altered and lethal toxicity, with severe intestinal lesions as a major cause of death. Simultaneous inhibition of CYP3A/P-gp might thus be a highly effective strategy to improve oral drug bioavailability but with serious risks when applied to drugs with narrow therapeutic windows. [Cancer Res 2009;69(23):8996–9002]
Data from Functional Genetic Polymorphisms in the Aromatase Gene CYP19 Vary the Response of Breast Cancer Patients to Neoadjuvant Therapy with Aromatase Inhibitors
Authors: Wang Liewei , Ellsworth Katarzyna A. , Moon Irene , Pelleymounter Linda L. , Eckloff Bruce W. , Martin Yvette N. , Fridley Brooke L. , Jenkins Gregory D. , Batzler Anthony , Suman Vera J. , Ravi Saranya , Dixon J. Michael , Miller William R. , Wieben Eric D. , Buzdar Aman , Weinshilboum Richard M. , Ingle James N.
Published: March 2023

Abstract
Aromatase (CYP19) is a critical enzyme in estrogen biosynthesis and aromatase inhibitors (AI) are employed widely for endocrine therapy in postmenopausal women with breast cancer. We hypothesized that single nucleotide polymorphisms (SNPs) in the CYP19 gene may alter the effectiveness of AI therapy in the neoadjuvant setting. Genomic DNA was obtained for sequencing from 52 women pre-AI and post-AI treatment in this setting. Additionally, genomic DNA obtained from 82 samples of breast cancer and 19 samples of normal breast tissue was subjected to resequencing. No differences in CYP19 sequence were observed between tumor and germ-line DNA in the same patient. A total of 48 SNPs were identified including 4 novel SNPs when compared with previous resequencing data. For genotype-phenotype association studies, we determined the levels of aromatase activity, estrone, estradiol, and tumor size in patients pre-AI and post-AI treatment. We defined two tightly linked SNPs (rs6493497 and rs7176005 in the 5'-flanking region of CYP19 exon 1.1) that were significantly associated with a greater change in aromatase activity after AI treatment. In a follow-up study of 200 women with early-stage breast cancer who were treated with adjuvant anastrozole, these same two SNPs were also associated with higher plasma estradiol levels in patients pre-AI and post-AI treatment. Electrophoretic mobility shift and reporter gene assays confirmed likely functional effects of these two SNPs on transcription of CYP19. Our findings indicate that two common genetic polymorphisms in the aromatase gene CYP19 vary the response of breast cancer patients to aromatase inhibitors. Cancer Res; 70(1); 319–28
Data from Presence of a Putative Tumor-Initiating Progenitor Cell Population Predicts Poor Prognosis in Smokers with Non–Small Cell Lung Cancer
Authors: Ooi Aik T. , Mah Vei , Nickerson Derek W. , Gilbert Jennifer L. , Ha Vi Luan , Hegab Ahmed E. , Horvath Steve , Alavi Mohammad , Maresh Erin L. , Chia David , Gower Adam C. , Lenburg Marc E. , Spira Avrum , Solis Luisa M. , Wistuba Ignacio I. , Walser Tonya C. , Wallace William D. , Dubinett Steven M. , Goodglick Lee , Gomperts Brigitte N.
Published: March 2023

Abstract
Smoking is the most important known risk factor for the development of lung cancer. Tobacco exposure results in chronic inflammation, tissue injury, and repair. A recent hypothesis argues for a stem/progenitor cell involved in airway epithelial repair that may be a tumor-initiating cell in lung cancer and which may be associated with recurrence and metastasis. We used immunostaining, quantitative real-time PCR, Western blots, and lung cancer tissue microarrays to identify subpopulations of airway epithelial stem/progenitor cells under steady-state conditions, normal repair, aberrant repair with premalignant lesions and lung cancer, and their correlation with injury and prognosis. We identified a population of keratin 14 (K14)–expressing progenitor epithelial cells that was involved in repair after injury. Dysregulated repair resulted in the persistence of K14+ cells in the airway epithelium in potentially premalignant lesions. The presence of K14+ progenitor airway epithelial cells in NSCLC predicted a poor prognosis, and this predictive value was strongest in smokers, in which it also correlated with metastasis. This suggests that reparative K14+ progenitor cells may be tumor-initiating cells in this subgroup of smokers with NSCLC. Cancer Res; 70(16); 6639–48. ©2010 AACR.
Data from Signatures of MicroRNAs and Selected MicroRNA Target Genes in Human Melanoma
Authors: Philippidou Demetra , Schmitt Martina , Moser Dirk , Margue Christiane , Nazarov Petr V. , Muller Arnaud , Vallar Laurent , Nashan Dorothee , Behrmann Iris , Kreis Stephanie
Published: March 2023

Abstract
Small noncoding microRNAs (miRNA) regulate the expression of target mRNAs by repressing their translation or orchestrating their sequence-specific degradation. In this study, we investigated miRNA and miRNA target gene expression patterns in melanoma to identify candidate biomarkers for early and progressive disease. Because data presently available on miRNA expression in melanoma are inconsistent thus far, we applied several different miRNA detection and profiling techniques on a panel of 10 cell lines and 20 patient samples representing nevi and primary or metastatic melanoma. Expression of selected miRNAs was inconsistent when comparing cell line–derived and patient-derived data. Moreover, as expected, some discrepancies were also detected when miRNA microarray data were correlated with qPCR-measured expression levels. Nevertheless, we identified miRNA-200c to be consistently downregulated in melanocytes, melanoma cell lines, and patient samples, whereas miRNA-205 and miRNA-23b were markedly reduced only in patient samples. In contrast, miR-146a and miR-155 were upregulated in all analyzed patients but none of the cell lines. Whole-genome microarrays were performed for analysis of selected melanoma cell lines to identify potential transcriptionally regulated miRNA target genes. Using Ingenuity pathway analysis, we identified a deregulated gene network centered around microphthalmia-associated transcription factor, a transcription factor known to play a key role in melanoma development. Our findings define miRNAs and miRNA target genes that offer candidate biomarkers in human melanoma. Cancer Res; 70(10); 4163–73. ©2010 AACR.
Data from Angiopoietin-2 Regulates Gene Expression in TIE2-Expressing Monocytes and Augments Their Inherent Proangiogenic Functions
Authors: Coffelt Seth B. , Tal Andrea O. , Scholz Alexander , De Palma Michele , Patel Sunil , Urbich Carmen , Biswas Subhra K. , Murdoch Craig , Plate Karl H. , Reiss Yvonne , Lewis Claire E.
Published: March 2023

Abstract
TIE2-expressing monocytes/macrophages (TEM) are a highly proangiogenic subset of myeloid cells in tumors. Here, we show that circulating human TEMs are already preprogrammed in the circulation to be more angiogenic and express higher levels of such proangiogenic genes as matrix metalloproteinase-9 (MMP-9), VEGFA, COX-2, and WNT5A than TIE2− monocytes. Additionally, angiopoietin-2 (ANG-2) markedly enhanced the proangiogenic activity of TEMs and increased their expression of two proangiogenic enzymes: thymidine phosphorylase (TP) and cathepsin B (CTSB). Three “alternatively activated” (or M2-like) macrophage markers were also upregulated by ANG-2 in TEMs: interleukin-10, mannose receptor (MRC1), and CCL17. To investigate the effects of ANG-2 on the phenotype and function of TEMs in tumors, we used a double-transgenic (DT) mouse model in which ANG-2 was specifically overexpressed by endothelial cells. Syngeneic tumors grown in these ANG-2 DT mice were more vascularized and contained greater numbers of TEMs than those in wild-type (WT) mice. In both tumor types, expression of MMP-9 and MRC1 was mainly restricted to tumor TEMs rather than TIE2− macrophages. Furthermore, tumor TEMs expressed higher levels of MRC1, TP, and CTSB in ANG-2 DT tumors than WT tumors. Taken together, our data show that although circulating TEMs are innately proangiogenic, exposure to tumor-derived ANG-2 stimulates these cells to exhibit a broader, tumor-promoting phenotype. As such, the ANG-2–TEM axis may represent a new target for antiangiogenic cancer therapies. Cancer Res; 70(13); 5270–80. ©2010 AACR.
Data from Differential Enhancement of Breast Cancer Cell Motility and Metastasis by Helical and Kinase Domain Mutations of Class IA Phosphoinositide 3-Kinase
Authors: Pang Huan , Flinn Rory , Patsialou Antonia , Wyckoff Jeffrey , Roussos Evanthia T. , Wu Haiyan , Pozzuto Maria , Goswami Sumanta , Condeelis John S. , Bresnick Anne R. , Segall Jeffrey E. , Backer Jonathan M.
Published: March 2023

Abstract
Class IA (p85/p110) phosphoinositide 3-kinases play a major role in regulating cell growth, survival, and motility. Activating mutations in the p110α isoform of the class IA catalytic subunit (PIK3CA) are commonly found in human cancers. These mutations lead to increased proliferation and transformation in cultured cells, but their effects on cell motility and tumor metastasis have not been evaluated. We used lentiviral-mediated gene transfer and knockdown to produce stable MDA-MB-231 cells in which the endogenous human p110α is replaced with either wild-type bovine p110α or the two most common activating p110α mutants, the helical domain mutant E545K and the kinase domain mutant H1047R. The phosphoinositide 3-kinase/Akt pathway was hyperactivated in cells expressing physiologic levels of helical or kinase domain mutants. Cells expressing either mutant showed increased motility in vitro, but only cells expressing the helical domain mutant showed increased directionality in a chemotaxis assay. In severe combined immunodeficient mice, xenograft tumors expressing either mutant showed increased rates of tumor growth compared with tumors expressing wild-type p110α. However, tumors expressing the p110α helical domain mutant showed a marked increase in both tumor cell intravasation into the blood and tumor cell extravasation into the lung after tail vein injection compared with tumors expressing wild-type p110α or the kinase domain mutant. Our observations suggest that, when compared with kinase domain mutations in a genetically identical background, expression of helical domain mutants of p110α produce a more severe metastatic phenotype. [Cancer Res 2009;69(23):8868–76]
Data from Epigenetic Silencing of the Sulfate Transporter Gene DTDST Induces Sialyl Lewisx Expression and Accelerates Proliferation of Colon Cancer Cells
Authors: Yusa Akiko , Miyazaki Keiko , Kimura Naoko , Izawa Mineko , Kannagi Reiji
Published: March 2023

Abstract
Colon cancer cells express the carbohydrate determinant sialyl Lewisx, while they exhibit markedly decreased the expression of its sulfated derivative, sialyl 6-sulfo Lewisx. In contrast, normal colonic epithelial cells strongly express sialyl 6-sulfo Lewisx, but they virtually do not express sialyl Lewisx. Impaired sulfation was therefore suggested to occur during the course of malignant transformation of colonic epithelial cells and was assumed to be responsible for the increased sialyl Lewisx expression in cancers. To elucidate the molecular biological background of the impaired sulfation in cancers, we studied the expression levels of mRNA for 6-O-sulfotransferase isoenzymes, PAPS synthases and transporters, and a cell membrane sulfate transporter, DTDST, in cancer tissues. The most striking decrease in cancer cells compared with nonmalignant epithelial cells was noted in the transcription of the DTDST gene (P = 0.0000014; n = 20). Most cultured colon cancer cells had a diminished DTDST transcription, which was restored when cultured with histone deacetylase inhibitors. Suppression of DTDST transcription under the control of a tet-off inducible promoter resulted in increased sialyl Lewisx expression and reduced sialyl 6-sulfo Lewisx expression. Unexpectedly, the growth rate of the cancer cells was markedly enhanced when transcription of DTDST was suppressed. These results show that the decrease in the transcription of the sulfate transporter gene is the major cause of decreased expression of sialyl 6-sulfo Lewisx and increased expression of sialyl Lewisx in colon cancers. The results also suggest that the diminished DTDST expression is closely related to enhanced proliferation of cancer cells. Cancer Res; 70(10); 4064–73. ©2010 AACR.
Data from Immutable Functional Attributes of Histologic Grade Revealed by Context-Independent Gene Expression in Primary Breast Cancer Cells
Authors: Dairkee Shanaz H. , Sayeed Aejaz , Luciani Gloria , Champion Stacey , Meng Zhenhang , Jakkula Lakshmi R. , Feiler Heidi S. , Gray Joe W. , Moore Dan H.
Published: March 2023

Abstract
Inherent cancer phenotypes that are independent of fluctuating cross-talk with the surrounding tissue matrix are highly desirable candidates for targeting tumor cells. Our novel study design uses epithelial cell lines derived from low versus high histologic grade primary breast cancer to effectively diminish the breadth of transient variability generated within the tumor microenvironment of the host, revealing a “paracrine-independent expression of grade-associated” (PEGA) gene signature. PEGA members extended beyond “proliferation-driven” signatures commonly associated with aggressive, high-grade breast cancer. The calcium-binding protein S100P was prominent among PEGA genes overexpressed in high-grade tumors. A three-member fingerprint of S100P-correlated genes, consisting of GPRC5A, FXYD3, and PYCARD, conferred poor outcome in multiple breast cancer data sets, irrespective of estrogen receptor status but dependent on tumor size (P < 0.01). S100P silencing markedly diminished coregulated gene transcripts and reversed aggressive tumor behavior. Exposure to pathway-implicated agents, including the calmodulin inhibitor N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide, phenothiazine, and chlorpromazine, resulted in rapid apoptotic cell death in high-grade tumor cells resistant to the chemotherapeutic drug cisplatin. This is the first comprehensive study describing molecular phenotypes intimately associated with histologic grade whose expression remains relatively fixed despite an unavoidably changing environment to which tumor cells are invariably exposed. [Cancer Res 2009;69(19):7826–34]
Data from Tangeretin Sensitizes Cisplatin-Resistant Human Ovarian Cancer Cells through Downregulation of Phosphoinositide 3-Kinase/Akt Signaling Pathway
Authors: Arafa El-Shaimaa A. , Zhu Qianzheng , Barakat Bassant M. , Wani Gulzar , Zhao Qun , El-Mahdy Mohamed A. , Wani Altaf A.
Published: March 2023

Abstract
Combination of innocuous dietary components with anticancer drugs is an emerging new strategy for cancer chemotherapy to increase antitumor responses. Tangeretin is a citrus flavonoid known to inhibit cancer cell proliferation. Here, we show an enhanced response of A2780/CP70 and 2008/C13 cisplatin-resistant human ovarian cancer cells to various combination treatments of cisplatin and tangeretin. Pretreatment of cells with tangeretin before cisplatin treatment synergistically inhibited cancer cell proliferation. This combination was effective in activating apoptosis via caspase cascade as well as arresting cell cycle at G2-M phase. Moreover, phospho-Akt and its downstream substrates, e.g., NF-κB, phospho-GSK-3β, and phospho-BAD, were downregulated upon tangeretin-cisplatin treatment. The tangeretin-cisplatin–induced apoptosis in A2780/CP70 cells was increased by phosphoinositide-3 kinase (PI3K) inhibition and siRNA-mediated Akt silencing, but reduced by overexpression of constitutively activated Akt and GSK-3β inhibition. The overall results indicated that tangeretin exposure preconditions cisplatin-resistant human ovarian cancer cells for a conventional response to low-dose cisplatin-induced cell death occurring through downregulation of PI3K/Akt signaling pathway. Thus, effectiveness of tangeretin combinations, as a promising modality in the treatment of resistant cancers, warrants systematic clinical studies. [Cancer Res 2009;69(23):8910–7]
Data from ΔNp63α Repression of the Notch1 Gene Supports the Proliferative Capacity of Normal Human Keratinocytes and Cervical Cancer Cells
Authors: Yugawa Takashi , Narisawa-Saito Mako , Yoshimatsu Yuki , Haga Kei , Ohno Shin-ichi , Egawa Nagayasu , Fujita Masatoshi , Kiyono Tohru
Published: March 2023

Abstract
The p53 family member p63 is a master regulator of epithelial development. One of its isoforms, ΔNp63α, is predominantly expressed in the basal cells of stratified epithelia and plays a fundamental role in control of regenerative potential and epithelial integrity. In contrast to p53, p63 is rarely mutated in human cancers, but it is frequently overexpressed in squamous cell carcinomas (SCC). However, its functional relevance to tumorigenesis remains largely unclear. We previously identified the Notch1 gene as a novel transcriptional target of p53. Here, we show that ΔNp63α functions as a transcriptional repressor of the Notch1 gene through the p53-responsive element. Knockdown of p63 caused upregulation of Notch1 expression and marked reduction in proliferation and clonogenicity of both normal human keratinocytes and cervical cancer cell lines overexpressing ΔNp63α. Concomitant silencing of Notch1 significantly rescued this phenotype, indicating the growth defect induced by p63 deficiency to be, at least in part, attributable to Notch1 function. Conversely, overexpression of ΔNp63α decreased basal levels of Notch1, increased proliferative potential of normal human keratinocytes, and inhibited both p53-dependent and p53-independent induction of Notch1 and differentiation markers upon genotoxic stress and serum exposure, respectively. These results suggest that ΔNp63α maintains the self-renewing capacity of normal human keratinocytes and cervical cancer cells partly through transcriptional repression of the Notch1 gene and imply a novel pathogenetical significance of frequently observed overexpression of ΔNp63α together with p53 inactivation in SCCs. Cancer Res; 70(10); 4034–44. ©2010 AACR.
Data from Breast Cancer Cells in Three-dimensional Culture Display an Enhanced Radioresponse after Coordinate Targeting of Integrin α5β1 and Fibronectin
Authors: Nam Jin-Min , Onodera Yasuhito , Bissell Mina J. , Park Catherine C.
Published: March 2023

Abstract
Tactics to selectively enhance cancer radioresponse are of great interest. Cancer cells actively elaborate and remodel their extracellular matrix (ECM) to aid in survival and progression. Previous work has shown that β1-integrin inhibitory antibodies can enhance the growth-inhibitory and apoptotic responses of human breast cancer cell lines to ionizing radiation, either when cells are cultured in three-dimensional laminin-rich ECM (3D lrECM) or grown as xenografts in mice. Here, we show that a specific α heterodimer of β1-integrin preferentially mediates a prosurvival signal in human breast cancer cells that can be specifically targeted for therapy. 3D lrECM culture conditions were used to compare α-integrin heterodimer expression in malignant and nonmalignant cell lines. Under these conditions, we found that expression of α5β1-integrin was upregulated in malignant cells compared with nonmalignant breast cells. Similarly, we found that normal and oncofetal splice variants of fibronectin, the primary ECM ligand of α5β1-integrin, were also strikingly upregulated in malignant cell lines compared with nonmalignant acini. Cell treatment with a peptide that disrupts the interactions of α5β1-integrin with fibronectin promoted apoptosis in malignant cells and further heightened the apoptotic effects of radiation. In support of these results, an analysis of gene expression array data from breast cancer patients revealed an association of high levels of α5-integrin expression with decreased survival. Our findings offer preclinical validation of fibronectin and α5β1-integrin as targets for breast cancer therapy. Cancer Res; 70(13); 5238–48. ©2010 AACR.