bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Recognition of Recurrent Protein Expression Patterns in Pediatric Acute Myeloid Leukemia Identified New Therapeutic Targets
Authors: Hoff Fieke W. , Hu Chenyue W. , Qiu Yihua , Ligeralde Andrew , Yoo Suk-Young , Mahmud Hasan , de Bont Eveline S.J.M. , Qutub Amina A. , Horton Terzah M. , Kornblau Steven M.
Published: April 2023

Abstract
Heterogeneity in the genetic landscape of pediatric acute myeloid leukemia (AML) makes personalized medicine challenging. As genetic events are mediated by the expression and function of proteins, recognition of recurrent protein patterns could enable classification of pediatric AML patients and could reveal crucial protein dependencies. This could help to rationally select combinations of therapeutic targets. To determine whether protein expression levels could be clustered into functionally relevant groups, custom reverse-phase protein arrays were performed on pediatric AML (n = 95) and CD34+ normal bone marrow (n = 10) clinical specimens using 194 validated antibodies. To analyze proteins in the context of other proteins, all proteins were assembled into 31 protein functional groups (PFG). For each PFG, an optimal number of protein clusters was defined that represented distinct transition states. Block clustering analysis revealed strong correlations between various protein clusters and identified the existence of 12 protein constellations stratifying patients into 8 protein signatures. Signatures were correlated with therapeutic outcome, as well as certain laboratory and demographic characteristics. Comparison of acute lymphoblastic leukemia specimens from the same array and AML pediatric patient specimens demonstrated disease-specific signatures, but also identified the existence of shared constellations, suggesting joint protein deregulation between the diseases.

Implication: Recognition of altered proteins in particular signatures suggests rational combinations of targets that could facilitate stratified targeted therapy. Mol Cancer Res; 16(8); 1275–86. ©2018 AACR.

See related article by Hoff et al., p. 1263
Data from Combined AURKA and H3K9 Methyltransferase Targeting Inhibits Cell Growth By Inducing Mitotic Catastrophe
Authors: Mathison Angela , Salmonson Ann , Missfeldt Mckenna , Bintz Jennifer , Williams Monique , Kossak Sarah , Nair Asha , de Assuncao Thiago M. , Christensen Trace , Buttar Navtej , Iovanna Juan , Huebert Robert , Lomberk Gwen
Published: April 2023

Abstract
The current integrative pathobiologic hypothesis states that pancreatic cancer (PDAC) develops and progresses in response to an interaction between known oncogenes and downstream epigenomic regulators. Congruently, this study tests a new combinatorial therapy based on the inhibition of the Aurora kinase A (AURKA) oncogene and one of its targets, the H3K9 methylation–based epigenetic pathway. This therapeutic combination is effective at inhibiting the in vitro growth of PDAC cells both, in monolayer culture systems, and in three-dimensional spheroids and organoids. The combination also reduces the growth of PDAC xenografts in vivo. Mechanistically, it was found that inhibiting methyltransferases of the H3K9 pathway in cells, which are arrested in G2–M after targeting AURKA, decreases H3K9 methylation at centromeres, induces mitotic aberrations, triggers an aberrant mitotic check point response, and ultimately leads to mitotic catastrophe. Combined, these data describe for the first time a hypothesis-driven design of an efficient combinatorial treatment that targets a dual oncogenic–epigenomic pathway to inhibit PDAC cell growth via a cytotoxic mechanism that involves perturbation of normal mitotic progression to end in mitotic catastrophe. Therefore, this new knowledge has significant mechanistic value as it relates to the development of new therapies as well as biomedical relevance.

Implications: These results outline a model for the combined inhibition of a genetic-to-epigenetic pathway to inhibit cell growth and suggest an important and provocative consideration for harnessing the capacity of cell-cycle inhibitors to enhance the future use of epigenetic inhibitors. Mol Cancer Res; 15(8); 984–97. ©2017 AACR.
Data from Targeting of SGK1 by miR-576-3p Inhibits Lung Adenocarcinoma Migration and Invasion
Authors: Greenawalt Evan J. , Edmonds Mick D. , Jain Neha , Adams Clare M. , Mitra Ramkrishna , Eischen Christine M.
Published: April 2023

Abstract
Metastatic lung cancer is common in patients with lung adenocarcinoma, but the molecular mechanisms of metastasis remain incompletely resolved. miRNA regulate gene expression and contribute to cancer development and progression. This report identifies miR-576-3p and its mechanism of action in lung cancer progression. miR-576-3p was determined to be significantly decreased in clinical specimens of late-stage lung adenocarcinoma. Overexpression of miR-576-3p in lung adenocarcinoma cells decreased mesenchymal marker expression and inhibited migration and invasion. Inhibition of miR-576-3p in nonmalignant lung epithelial cells increased migration and invasion as well as mesenchymal markers. Serum/glucocorticoid–regulated kinase 1 (SGK1) was a direct target of miR-576-3p, and modulation of miR-576-3p levels led to alterations in SGK1 protein and mRNA as well as changes in activation of its downstream target linked to metastasis, N-myc downstream regulated 1 (NDRG1). Loss of the ability of miR-576-3p to bind the 3′-UTR of SGK1 rescued the inhibition in migration and invasion observed with miR-576-3p overexpression. In addition, increased SGK1 levels were detected in lung adenocarcinoma patient samples expressing mesenchymal markers, and pharmacologic inhibition of SGK1 resulted in a similar inhibition of migration and invasion of lung adenocarcinoma cells as observed with miR-576-3p overexpression. Together, these results reveal miR-576-3p downregulation is selected for in late-stage lung adenocarcinoma due to its ability to inhibit migration and invasion by targeting SGK1. Furthermore, these results also support targeting SGK1 as a potential therapeutic for lung adenocarcinoma.
Implications:
This study reveals SGK1 inhibition with miR-576-3p or pharmacologically inhibits migration and invasion of lung adenocarcinoma, providing mechanistic insights into late-stage lung adenocarcinoma and a potential new treatment avenue.
Data from HPV Integration in HNSCC Correlates with Survival Outcomes, Immune Response Signatures, and Candidate Drivers
Authors: Koneva Lada A. , Zhang Yanxiao , Virani Shama , Hall Pelle B. , McHugh Jonathan B. , Chepeha Douglas B. , Wolf Gregory T. , Carey Thomas E. , Rozek Laura S. , Sartor Maureen A.
Published: April 2023

Abstract
The incidence of human papillomavirus (HPV)–related oropharynx cancer has steadily increased over the past two decades and now represents a majority of oropharyngeal cancer cases. Integration of the HPV genome into the host genome is a common event during carcinogenesis that has clinically relevant effects if the viral early genes are transcribed. Understanding the impact of HPV integration on clinical outcomes of head and neck squamous cell carcinoma (HNSCC) is critical for implementing deescalated treatment approaches for HPV+ HNSCC patients. RNA sequencing (RNA-seq) data from HNSCC tumors (n = 84) were used to identify and characterize expressed integration events, which were overrepresented near known head and neck, lung, and urogenital cancer genes. Five genes were recurrent, including CD274 (PD-L1). A significant number of genes detected to have integration events were found to interact with Tp63, ETS, and/or FOX1A. Patients with no detected integration had better survival than integration-positive and HPV− patients. Furthermore, integration-negative tumors were characterized by strongly heightened signatures for immune cells, including CD4+, CD3+, regulatory, CD8+ T cells, NK cells, and B cells, compared with integration-positive tumors. Finally, genes with elevated expression in integration-negative specimens were strongly enriched with immune-related gene ontology terms, while upregulated genes in integration-positive tumors were enriched for keratinization, RNA metabolism, and translation.

Implications: These findings demonstrate the clinical relevancy of expressed HPV integration, which is characterized by a change in immune response and/or aberrant expression of the integration-harboring cancer-related genes, and suggest strong natural selection for tumor cells with expressed integration events in key carcinogenic genes. Mol Cancer Res; 16(1); 90–102. ©2017 AACR.
Data from FLYWCH1, a Novel Suppressor of Nuclear β-Catenin, Regulates Migration and Morphology in Colorectal Cancer
Authors: Muhammad Belal A. , Almozyan Sheema , Babaei-Jadidi Roya , Onyido Emenike K. , Saadeddin Anas , Kashfi Seyed Hossein , Spencer-Dene Bradley , Ilyas Mohammad , Lourdusamy Anbarasu , Behrens Axel , Nateri Abdolrahman S.
Published: April 2023

Abstract
Wnt/β-catenin signaling plays a critical role during development of both normal and malignant colorectal cancer tissues. Phosphorylation of β-catenin protein alters its trafficking and function. Such conventional allosteric regulation usually involves a highly specialized set of molecular interactions, which may specifically turn on a particular cell phenotype. This study identifies a novel transcription modulator with an FLYWCH/Zn-finger DNA-binding domain, called “FLYWCH1.” Using a modified yeast-2-hybrid based Ras-Recruitment system, it is demonstrated that FLYWCH1 directly binds to unphosphorylated (nuclear) β-catenin efficiently suppressing the transcriptional activity of Wnt/β-catenin signaling that cannot be rescued by TCF4. FLYWCH1 rearranges the transcriptional activity of β-catenin/TCF4 to selectively block the expression of specific downstream genes associated with colorectal cancer cell migration and morphology, including ZEB1, EPHA4, and E-cadherin. Accordingly, overexpression of FLYWCH1 reduces cell motility and increases cell attachment. The expression of FLYWCH1 negatively correlates with the expression level of ZEB1 and EPHA4 in normal versus primary and metastatic colorectal cancer tissues in patients. Thus, FLYWCH1 antagonizes β-catenin/TCF4 signaling during cell polarity/migration in colorectal cancer.
Implications:
This study uncovers a new molecular mechanism by which FLYWCH1 with a possible tumor suppressive role represses β-catenin-induced ZEB1 and increases cadherin-mediated cell attachment preventing colorectal cancer metastasis.
Data from Mechanochemical Disruption Suppresses Metastatic Phenotype and Pushes Prostate Cancer Cells toward Apoptosis
Authors: Murad Hakm Y. , Yu Heng , Luo Daishen , Bortz Emma P. , Halliburton Gray M. , Sholl Andrew B. , Khismatullin Damir B.
Published: April 2023

Abstract
Chemical-based medicine that targets specific oncogenes or proteins often leads to cancer recurrence due to tumor heterogeneity and development of chemoresistance. This challenge can be overcome by mechanochemical disruption of cancer cells via focused ultrasound (FUS) and sensitizing chemical agents such as ethanol. We demonstrate that this disruptive therapy decreases the viability, proliferation rate, tumorigenicity, endothelial adhesion, and migratory ability of prostate cancer cells in vitro. It sensitized the cells to TNFR1-‐ and Fas-‐mediated apoptosis and reduced the expression of metastatic markers CD44 and CD29. Using a prostate cancer xenograft model, we observed that the mechanochemical disruption led to complete tumor regression in vivo. This switch to a nonaggressive cell phenotype was caused by ROS and Hsp70 overproduction and subsequent impairment of NFκB signaling. FUS induces mechanical perturbations of diverse cancer cell populations, and its combination with agents that amplify and guide remedial cellular responses can stop lethal cancer progression.
Implications:
Mechanochemical disruption therapy in which FUS is combined with ethanol can be curative for locally aggressive and castration-resistant prostate cancer.
Data from The TWEAK Receptor Fn14 Is an Src-Inducible Protein and a Positive Regulator of Src-Driven Cell Invasion
Authors: Cheng Emily , Whitsett Timothy G. , Tran Nhan L. , Winkles Jeffrey A.
Published: April 2023

Abstract
The TNF receptor superfamily member Fn14 (TNFRSF12A) is the sole signaling receptor for the proinflammatory cytokine TWEAK (TNFSF12). TWEAK:Fn14 engagement stimulates multiple signal transduction pathways, including the NF-κB pathway, and this triggers important cellular processes (e.g., growth, differentiation, migration, and invasion). The TWEAK–Fn14 axis is thought to be a major physiologic mediator of tissue repair after acute injury. Various studies have revealed that Fn14 is highly expressed in many solid tumor types, and that Fn14 signaling may play a role in tumor growth and metastasis. Previously, it was shown that Fn14 levels are frequently elevated in non–small cell lung cancer (NSCLC) tumors and cell lines that exhibit constitutive EGFR phosphorylation (activation). Furthermore, elevated Fn14 levels increased NSCLC cell invasion in vitro and lung metastatic tumor colonization in vivo. The present study reveals that EGFR-mutant NSCLC cells that express high levels of Fn14 exhibit constitutive activation of the cytoplasmic tyrosine kinase Src, and that treatment with the Src family kinase (SFK) inhibitor dasatinib decreases Fn14 gene expression at both the mRNA and protein levels. Importantly, siRNA-mediated depletion of the SFK member Src in NSCLC cells also decreases Fn14 expression. Finally, expression of the constitutively active v-Src oncoprotein in NIH 3T3 cells induces Fn14 gene expression, and NIH 3T3/v-Src cells require Fn14 expression for full invasive capacity.

Implications: These results indicate that oncogenic Src may contribute to Fn14 overexpression in solid tumors, and that Src-mediated cell invasion could potentially be inhibited with Fn14-targeted therapeutics. Mol Cancer Res; 13(3); 575–83. ©2014 AACR.
Data from Genetic Ablation of the Tetraspanin CD151 Reduces Spontaneous Metastatic Spread of Prostate Cancer in the TRAMP Model
Authors: Copeland Ben T. , Bowman Matthew J. , Ashman Leonie K.
Published: April 2023

Abstract
Tetraspanins are integral membrane proteins that associate with motility-related molecules such as integrins. Experimental studies have indicated that they may be important regulators of tumor invasion and metastasis, and high expression of the tetraspanin CD151 has been linked to poor prognosis in a number of cancers. Here, we show for the first time that genetic ablation of CD151 inhibits spontaneous metastasis in a transgenic mouse model of de novo tumorigenesis. To evaluate the effects of CD151 on de novo prostate cancer initiation and metastasis, a Cd151−/− (KO) murine model was crossed with the Transgenic Adenocarcinoma of Mouse Prostate (TRAMP) model. Mice were analyzed for initiation of prostate tumor by palpation and primary tumors were analyzed by immunohistochemistry. Liver and lungs were examined for incidence and size of spontaneous metastatic lesions by histopathology. Knocking-out Cd151 had no significant effect on prostate cancer initiation or on expression of markers of proliferation, apoptosis, or angiogenesis in primary tumors. However, it did significantly decrease metastasis in a site-specific fashion, notably to the lungs but not the liver. Thus, CD151 acts principally as promoter of metastasis in this model. Prostate cancer is the second highest cause of cancer-related deaths in men in most Western countries, with the majority of deaths attributed to late-stage metastatic disease. CD151 may prove to be a valuable prognostic marker for treatment stratification and is a possible antimetastatic target. Mol Cancer Res; 11(1); 95–105. ©2012 AACR.
Data from Threonine 2609 Phosphorylation of the DNA-Dependent Protein Kinase Is a Critical Prerequisite for Epidermal Growth Factor Receptor–Mediated Radiation Resistance
Authors: Javvadi Prashanthi , Makino Haruhiko , Das Amit K. , Lin Yu-Fen , Chen David J. , Chen Benjamin P. , Nirodi Chaitanya S.
Published: April 2023

Abstract
The EGF receptor (EGFR) contributes to tumor radioresistance, in part, through interactions with the catalytic subunit of DNA-dependent protein kinase (DNA-PKc), a key enzyme in the nonhomologous end joining DNA repair pathway. We previously showed that EGFR-DNA-PKcs interactions are significantly compromised in the context of activating mutations in EGFR in non–small cell lung carcinoma (NSCLC) and human bronchial epithelial cells. Here, we investigate the reciprocal relationship between phosphorylation status of DNA-PKcs and EGFR-mediated radiation response. The data reveal that both the kinase activity of DNA-PKcs and radiation-induced phosphorylation of DNA-PKcs by the ataxia telangiectasia–mutated (ATM) kinase are critical prerequisites for EGFR-mediated radioresponse. Alanine substitutions at seven key serine/threonine residues in DNA-PKcs or inhibition of DNA-PKcs by NU7441 completely abrogated EGFR-mediated radioresponse and blocked EGFR binding. ATM deficiency or ATM inhibition with KU55933 produced a similar effect. Importantly, alanine substitution at an ATM-dependent DNA-PKcs phosphorylation site, T2609, was sufficient to block binding or radioresponse of EGFR. However, mutation of a DNA-PKcs autophosphorylation site, S2056 had no such effect indicating that DNA-PKcs autophosphorylation is not necessary for EGFR-mediated radioresponse. Our data reveal that in both NSCLCs and human bronchial epithelial cells, activating mutations in EGFR specifically abolished the DNA-PKcs phosphorylation at T2609, but not S2056. Our study underscores the critical importance of a reciprocal relationship between DNA-PKcs phosphorylation and EGFR-mediated radiation response and elucidates mechanisms underlying mutant EGFR-associated radiosensitivity in NSCLCs. Mol Cancer Res; 10(10); 1359–68. ©2012 AACR.
Data from The Proto-oncogene PKCι Regulates the Alternative Splicing of Bcl-x Pre-mRNA
Authors: Shultz Jacqueline C. , Vu Ngoc , Shultz Michael D. , Mba Mba-Uzoma U. , Shapiro Brian A. , Chalfant Charles E.
Published: April 2023

Abstract
Two splice variants derived from the Bcl-x gene via alternative 5′ splice site selection (5′SS) are proapoptotic Bcl-x(s) and antiapoptotic Bcl-x(L). Previously, our laboratory showed that apoptotic signaling pathways regulated the alternative 5′SS selection via protein phosphatase-1 and de novo ceramide. In this study, we examined the elusive prosurvival signaling pathways that regulate the 5′SS selection of Bcl-x pre-mRNA in cancer cells. Taking a broad-based approach by using a number of small-molecule inhibitors of various mitogenic/survival pathways, we found that only treatment of non–small cell lung cancer (NSCLC) cell lines with the phosphoinositide 3-kinase (PI3K) inhibitor LY294002 (50 μmol/L) or the pan-protein kinase C (PKC) inhibitor Gö6983 (25 μmol/L) decreased the Bcl-x(L)/(s) mRNA ratio. Pan-PKC inhibitors that did not target the atypical PKCs, PKCι and PKCζ, had no effect on the Bcl-x(L)/(s) mRNA ratio. Additional studies showed that downregulation of the proto-oncogene, PKCι, in contrast to PKCζ, also resulted in a decrease in the Bcl-x(L)/(s) mRNA ratio. Furthermore, downregulation of PKCι correlated with a dramatic decrease in the expression of SAP155, an RNA trans-acting factor that regulates the 5′SS selection of Bcl-x pre-mRNA. Inhibition of the PI3K or atypical PKC pathway induced a dramatic loss of SAP155 complex formation at ceramide-responsive RNA cis-element 1. Finally, forced expression of Bcl-x(L) “rescued” the loss of cell survival induced by PKCι siRNA. In summary, the PI3K/PKCι regulates the alternative splicing of Bcl-x pre-mRNA with implications in the cell survival of NSCLC cells. Mol Cancer Res; 10(5); 660–9. ©2012 AACR.
Data from Targeting RET Kinase in Neuroendocrine Prostate Cancer
Authors: VanDeusen Halena R. , Ramroop Johnny R. , Morel Katherine L. , Bae Song Yi , Sheahan Anjali V. , Sychev Zoi , Lau Nathan A. , Cheng Larry C. , Tan Victor M. , Li Zhen , Petersen Ashley , Lee John K. , Park Jung Wook , Yang Rendong , Hwang Justin H. , Coleman Ilsa , Witte Owen N. , Morrissey Colm , Corey Eva , Nelson Peter S. , Ellis Leigh , Drake Justin M.
Published: April 2023

Abstract
The increased treatment of metastatic castration-resistant prostate cancer (mCRPC) with second-generation antiandrogen therapies (ADT) has coincided with a greater incidence of lethal, aggressive variant prostate cancer (AVPC) tumors that have lost dependence on androgen receptor (AR) signaling. These AR-independent tumors may also transdifferentiate to express neuroendocrine lineage markers and are termed neuroendocrine prostate cancer (NEPC). Recent evidence suggests kinase signaling may be an important driver of NEPC. To identify targetable kinases in NEPC, we performed global phosphoproteomics comparing several AR-independent to AR-dependent prostate cancer cell lines and identified multiple altered signaling pathways, including enrichment of RET kinase activity in the AR-independent cell lines. Clinical NEPC patient samples and NEPC patient-derived xenografts displayed upregulated RET transcript and RET pathway activity. Genetic knockdown or pharmacologic inhibition of RET kinase in multiple mouse and human models of NEPC dramatically reduced tumor growth and decreased cell viability. Our results suggest that targeting RET in NEPC tumors with high RET expression could be an effective treatment option. Currently, there are limited treatment options for patients with aggressive neuroendocrine prostate cancer and none are curative.
Implications:
Identification of aberrantly expressed RET kinase as a driver of tumor growth in multiple models of NEPC provides a significant rationale for testing the clinical application of RET inhibitors in patients with AVPC.
Data from TRAIL Resistance of Breast Cancer Cells Is Associated with Constitutive Endocytosis of Death Receptors 4 and 5
Authors: Zhang Yaqin , Zhang Baolin
Published: April 2023

Abstract
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and its agnostic antibodies, which are being evaluated clinically as anticancer therapies, selectively kill cancer cells through the death receptors DR4 and DR5. However, their therapeutic potential is limited by occurring resistance in tumor cells. Here, we compared the apoptotic response of a panel of six human breast cancer cell lines with recombinant human TRAIL and antibodies to DR4 or DR5. Despite their total mRNA and protein expression, TRAIL death receptors, with a higher frequency in DR4, are absent on cell surface in some cell lines. Loss of cell surface expression of DR4 or DR5 accounts for resistance to their corresponding antibody and, importantly, correlates with a decreased sensitivity to TRAIL. TRAIL resistance occurs when both receptors are absent on cell surface regardless of alterations in Bcl-2 family proteins or caspases. Furthermore, inhibition of endocytosis by pharmacologic inhibitors or disruption of clathrin-dependent endocytosis signaling components (adaptor protein 2 and clathrin) restores cell surface expression of the death receptors and sensitize TRAIL-resistant cells to TRAIL-induced apoptosis. DR4 endocytosis appears to be mediated by its cytoplasmic domain EAQC337LL. The results show that TRAIL death receptors undergo constitutive endocytosis in some breast cancer cells. Loss of cell surface expression of DR4 and DR5 could be evaluated as a biomarker for TRAIL resistance in breast tumors. Moreover, the clathrin-mediated endocytosis pathway could be a potential target for therapeutics to overcome tumor resistance to TRAIL receptor-targeted therapies. (Mol Cancer Res 2008;6(12):1861–71)
Data from Biological Responses to TGF-β in the Mammary Epithelium Show a Complex Dependency on Smad3 Gene Dosage with Important Implications for Tumor Progression
Authors: Kohn Ethan A. , Yang Yu-an , Du Zhijun , Nagano Yoshiko , Van Schyndle Catherine M.H. , Herrmann Michelle A. , Heldman Madeleine , Chen Jin-Qiu , Stuelten Christina H. , Flanders Kathleen C. , Wakefield Lalage M.
Published: April 2023

Abstract
TGF-β plays a dual role in epithelial carcinogenesis with the potential to either suppress or promote tumor progression. We found that levels of Smad3 mRNA, a critical mediator of TGF-β signaling, are reduced by approximately 60% in human breast cancer. We therefore used conditionally immortalized mammary epithelial cells (IMEC) of differing Smad3 genotypes to quantitatively address the Smad3 requirement for different biologic responses to TGF-β. We found that a two-fold reduction in Smad3 gene dosage led to complex effects on TGF-β responses; the growth-inhibitory response was retained, the pro-apoptotic response was lost, the migratory response was reduced, and the invasion response was enhanced. Loss of the pro-apoptotic response in the Smad3+/− IMECs correlated with loss of Smad3 binding to the Bcl-2 locus, whereas retention of the growth-inhibitory response in Smad3 IMECs correlated with retention of Smad3 binding to the c-Myc locus. Addressing the integrated outcome of these changes in vivo, we showed that reduced Smad3 levels enhanced metastasis in two independent models of metastatic breast cancer. Our results suggest that different biologic responses to TGF-β in the mammary epithelium are differentially affected by Smad3 dosage and that a mere two-fold reduction in Smad3 is sufficient to promote metastasis. Mol Cancer Res; 10(10); 1389–99. ©2012 AACR.
Data from Copper Modulates Zinc Metalloproteinase-Dependent Ectodomain Shedding of Key Signaling and Adhesion Proteins and Promotes the Invasion of Prostate Cancer Epithelial Cells
Authors: Parr-Sturgess Catherine A. , Tinker Claire L. , Hart Claire A. , Brown Michael D. , Clarke Noel W. , Parkin Edward T.
Published: April 2023

Abstract
A disintegrin and metalloproteinases (ADAMs) and matrix metalloproteinases (MMPs) are zinc metalloproteinases (ZMPs) that catalyze the “ectodomain shedding” of a range of cell surface proteins including signaling and adhesion molecules. These “sheddases” are associated with the invasion and metastasis of a range of cancers. Increased serum and tumor tissue levels of copper are also observed in several cancers, although little is known about how the metal might promote disease progression at the molecular level. In the current study, we investigated whether copper might regulate the ectodomain shedding of two key cell surface proteins implicated in the invasion and metastasis of prostate cancer, the Notch ligand Jagged1 and the adhesion molecule E-cadherin, and whether the metal was able to influence the invasion of the prostate cancer epithelial cell line PC3. Physiological copper concentrations stimulated the ZMP-mediated proteolysis of Jagged1 and E-cadherin in cell culture models, whereas other divalent metals had no effect. Copper-mediated Jagged1 proteolysis was also observed following the pretreatment of cells with cycloheximide and in a cell-free membrane system, indicating a posttranslational mechanism of sheddase activation. Finally, the concentrations of copper that stimulated ZMP-mediated protein shedding also enhanced PC3 invasion; an effect that could be negated using a sheddase inhibitor or copper chelators. Collectively, these data implicate copper as an important factor in promoting prostate cancer cell invasion and indicate that the selective posttranslational activation of ZMP-mediated protein shedding might play a role in this process. Mol Cancer Res; 10(10); 1282–93. ©2012 AACR.
Data from Impaired Long-Term Expansion and Self-Renewal Potential of Pediatric Acute Myeloid Leukemia–Initiating Cells By PTK787/ZK 222584
Authors: Weidenaar Alida C. , ter Elst Arja , Kampen Kim R. , Meeuwsen-de Boer Tiny , Kamps Willem A. , Schuringa Jan Jacob , de Bont Eveline S.J.M.
Published: April 2023

Abstract
Although most children with acute myeloid leukemia (AML) achieve complete remission, the relapse rate is 30% to 40%. Because it is thought that leukemia-initiating cells (LIC) are responsible for AML relapses, targeting these cells might improve outcome. Treatment of pediatric AML blasts with the receptor tyrosine kinase (RTK) inhibitor PTK787/ZK 222584 (PTK/ZK) induces cell death in vitro. However, the role of PTK/ZK inhibition on outgrowth of (pediatric) LICs is unknown. In this study, we cultured CD34+ cells from pediatric patients with AML on MS5 stromal cells in long-term cocultures. In analogy to adult AML, long-term expansion of leukemic cells up to 10 weeks could be generated in 9 of 13 pediatric AMLs. Addition of PTK/ZK to long-term cocultures significantly inhibited leukemic expansion in all samples, ranging from 4% to 80% growth inhibition at week 5 compared with untreated samples. In 75% of the samples, the inhibitory effect was more pronounced at week 10. Proteome profiler array analysis of downstream kinases revealed that PTK/ZK reduced activation of PI3K/Akt kinase signaling. Although main targets of PTK/ZK are VEGF receptors (VEGFR), no effect was seen on outgrowth of LICs when cultured with bevacizumab (monoclonal VEGFA-antibody), specific antibodies against VEGFR2 or VEGFR3, or exposed to stroma-derived VEGFA. These data suggest that the effect of PTK/ZK on LICs is not only dependent on inhibition of VEGFA/VEGFR signaling. Taken together, our data elucidated antileukemic properties of PTK/ZK in long-term expansion cultures, and suggest that targeting multiple RTKs by PTK/ZK might be a potential effective approach in eradicating (pediatric) LICs. Mol Cancer Res; 11(4); 339–48. ©2013 AACR.
Data from Opposing Roles of c-Jun NH2-Terminal Kinase and p38 Mitogen-Activated Protein Kinase in the Cellular Response to Ionizing Radiation in Human Cervical Cancer Cells
Authors: Kim Min-Jung , Choi Soon-Young , Park In-Chul , Hwang Sang-Gu , Kim Changil , Choi Young-Hyun , Kim Haekwon , Lee Kee-Ho , Lee Su-Jae
Published: April 2023

Abstract
Exposure of cells to ionizing radiation induces activation of multiple signaling pathways that play critical roles in determining cell fate. However, the molecular basis for cell death or survival signaling in response to radiation is unclear at present. Here, we show opposing roles of the c-jun NH2-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) pathways in the mitochondrial cell death in response to ionizing radiation in human cervical cancer cells. Ionizing radiation triggered Bax and Bak activation, Bcl-2 down-regulation, and subsequent mitochondrial cell death. Inhibition of JNK completely suppressed radiation-induced Bax and Bak activation and Bcl-2 down-regulation. Dominant-negative forms of stress-activated protein kinase/extracellular signal-regulated kinase kinase 1 (SEK-1)/mitogen-activated protein kinase kinase-4 (MKK-4) inhibited JNK activation. Radiation also induced phosphoinositide 3-kinase (PI3K) activation. Interestingly, inhibition of PI3K effectively attenuated radiation-induced mitochondrial cell death and increased clonogenic survival. Inhibition of PI3K also suppressed SEK-1/MKK-4 and JNK activation, Bax and Bak activation, and Bcl-2 down-regulation. In contrast, inhibition of p38 MAPK led to enhanced Bax and Bak activation and mitochondrial cell death. RacN17, a dominant-negative form of Rac1, inhibited p38 MAPK activation and increased Bax and Bak activation. Exposure of cells to radiation also induced selective activation of c-Src among Src family kinases. Inhibition of c-Src by pretreatment with Src family kinase inhibitor PP2 or small interfering RNA targeting of c-Src attenuated radiation-induced p38 MAPK and Rac1 activation and enhanced Bax and Bak activation and cell death. Our results support the notion that the PI3K-SEK-1/MKK-4-JNK pathway is required for the mitochondrial cell death in response to radiation, whereas the c-Src-Rac1-p38 MAPK pathway plays a cytoprotective role against mitochondrial cell death. (Mol Cancer Res 2008;6(11):1718–31)
Data from Human ESC Self-renewal Promoting microRNAs Induce Epithelial–Mesenchymal Transition in Hepatocytes by Controlling the PTEN and TGFβ Tumor Suppressor Signaling Pathways
Authors: Jung Christine J. , Iyengar Sushma , Blahnik Kimberly R. , Jiang Joy X. , Tahimic Candice , Torok Natalie J. , de vere White Ralph W. , Farnham Peggy J. , Zern Mark
Published: April 2023

Abstract
The self-renewal capacity ascribed to embryonic stem cells (ESC) is reminiscent of cancer cell proliferation, raising speculation that a common network of genes may regulate these traits. A search for general regulators of these traits yielded a set of microRNAs for which expression is highly enriched in human ESCs and liver cancer cells (HCC) but attenuated in differentiated quiescent hepatocytes. Here, we show that these microRNAs promote hESC self-renewal, as well as HCC proliferation, and when overexpressed in normally quiescent hepatocytes, induce proliferation and activate cancer signaling pathways. Proliferation in hepatocytes is mediated through translational repression of Pten, Tgfbr2, Klf11, and Cdkn1a, which collectively dysregulates the PI3K/AKT/mTOR and TGFβ tumor suppressor signaling pathways. Furthermore, aberrant expression of these miRNAs is observed in human liver tumor tissues and induces epithelial–mesenchymal transition in hepatocytes. These findings suggest that microRNAs that are essential in normal development as promoters of ESC self-renewal are frequently upregulated in human liver tumors and harbor neoplastic transformation potential when they escape silencing in quiescent human hepatocytes. Mol Cancer Res; 10(7); 979–91. ©2012 AACR.
Data from Notch Inhibits Expression of the Krüppel-Like Factor 4 Tumor Suppressor in the Intestinal Epithelium
Authors: Ghaleb Amr M. , Aggarwal Gaurav , Bialkowska Agnieszka B. , Nandan Mandayam O. , Yang Vincent W.
Published: April 2023

Abstract
The zinc finger-containing transcription factor, Krüppel-like factor 4 (KLF4), inhibits cell proliferation. An in vivo tumor-suppressive role for KLF4 is shown by the recent finding that Klf4 haploinsufficiency in ApcMin/+ mice promotes intestinal tumorigenesis. Studies also show that KLF4 is required for the terminal differentiation of goblet cells in the mouse intestine. The Notch signaling pathway suppresses goblet cell formation and is up-regulated in intestinal tumors. Here, we investigated the relationship between Notch signaling and KLF4 expression in intestinal epithelial cells. The rate of proliferation of HT29 human colon cancer cells was reduced when treated with the γ-secretase inhibitor dibenzazepine to inhibit Notch signaling or small interfering RNA directed against Notch. KLF4 levels were increased in dibenzazepine-treated or Notch small interfering RNA-treated cells. Conversely, overexpression of Notch in HT29 cells reduced KLF4 levels, suppressed KLF4 promoter activity, and increased proliferation rate. Treatment of ApcMin/+ mice with dibenzazepine resulted in a 50% reduction in the number of intestinal adenomas compared with the vehicle-treated group (P < 0.001). Both the normal-appearing intestinal mucosa and adenomas obtained from dibenzazepine-treated ApcMin/+ mice had increased goblet cell numbers and Klf4 staining accompanied by reduced cyclin D1 and Ki-67 staining when compared with those from vehicle-treated mice. Results of these studies indicate that Notch signaling suppresses KLF4 expression in intestinal tumors and colorectal cancer cells. Inhibition of Notch signaling increases KLF4 expression and goblet cell differentiation and reduces proliferation and tumor formation. KLF4 is therefore a potential mediator for the antitumor effect of Notch inhibitors such as dibenzazepine. (Mol Cancer Res 2008;6(12):1920–7)
Data from The Tyrosine Kinase Adaptor Protein FRS2 Is Oncogenic and Amplified in High-Grade Serous Ovarian Cancer
Authors: Luo Leo Y. , Kim Eejung , Cheung Hiu Wing , Weir Barbara A. , Dunn Gavin P. , Shen Rhine R. , Hahn William C.
Published: April 2023

Abstract
High-grade serous ovarian cancers (HGSOC) are characterized by widespread recurrent regions of copy-number gain and loss. Here, we interrogated 50 genes that are recurrently amplified in HGSOC and essential for cancer proliferation and survival in ovarian cancer cell lines. FRS2 is one of the 50 genes located on chromosomal region 12q15 that is focally amplified in 12.5% of HGSOC. We found that FRS2-amplified cancer cell lines are dependent on FRS2 expression, and that FRS2 overexpression in immortalized human cell lines conferred the ability to grow in an anchorage-independent manner and as tumors in immunodeficient mice. FRS2, an adaptor protein in the FGFR pathway, induces downstream activation of the Ras–MAPK pathway. These observations identify FRS2 as an oncogene in a subset of HGSOC that harbor FRS2 amplifications.

Implications: These studies identify FRS2 as an amplified oncogene in a subset of HGSOC. FRS2 expression is essential to ovarian cancer cells that harbor 12q15 amplification. Mol Cancer Res; 13(3); 502–9. ©2014 AACR.
Data from The Novel miR-7515 Decreases the Proliferation and Migration of Human Lung Cancer Cells by Targeting c-Met
Authors: Lee Ji Min , Yoo Jung Ki , Yoo Hanna , Jung Ho Yong , Lee Dong Ryul , Jeong Hye Cheol , Oh Seoung Hun , Chung Hyung Min , Kim Jin Kyeoung
Published: April 2023

Abstract
MicroRNAs (miRNA) are small noncoding RNAs that regulate gene expression in human diseases, including lung cancer. miRNAs have oncogenic and nononcogenic functions in lung cancer. In this study, we report the identification of a novel miRNA, miR-7515, from lung cancer cells. The novel miR-7515 was characterized using various predictive programs and experimental methods. miR-7515 was able to forming a stem-loop structure and its sequence was conserved in mammals. The expression level of miR-7515 in lung cancer cells and tissues was profiled using TaqMan miRNA assays. miR-7515 was downregulated in lung cancer compared with normal human lung cells and tissues. The target of miR-7515 was determined using a dual luciferase reporter assay. Expression of the target gene was determined by quantitative RT-PCR and Western blot analysis after transfection with miR-7515. miR-7515 directly suppressed human mesenchymal–epithelial transition factor (c-Met) by binding to the 3′ untranslated region (UTR). Overexpression of miR-7515 significantly decreased cell-cycle–related proteins downstream of c-Met through c-Met inhibition. Cell proliferation and migration were examined using the XTT proliferation assay and the Transwell migration assay. miR-7515 led to decreased cell proliferation, migration and invasion in a lung cancer cell line. These results suggest that miR-7515 plays an important role in the proliferation and migration of lung cancer cells through c-Met regulation. Mol Cancer Res; 11(1); 43–53. ©2012 AACR.
Data from miR-629 Targets TRIM33 to Promote TGFβ/Smad Signaling and Metastatic Phenotypes in ccRCC
Authors: Jingushi Kentaro , Ueda Yuko , Kitae Kaori , Hase Hiroaki , Egawa Hiroshi , Ohshio Ikumi , Kawakami Ryoji , Kashiwagi Yuri , Tsukada Yohei , Kobayashi Takumi , Nakata Wataru , Fujita Kazutoshi , Uemura Motohide , Nonomura Norio , Tsujikawa Kazutake
Published: April 2023

Abstract
Renal cell carcinoma (RCC) is the most common neoplasm of the adult kidney, and clear cell RCC (ccRCC) represents its most common histological subtype. To identify a therapeutic target for ccRCC, miRNA expression signatures from ccRCC clinical specimens were analyzed. miRNA microarray and real-time PCR analyses revealed that miR-629 expression was significantly upregulated in human ccRCC compared with adjacent noncancerous renal tissue. Functional inhibition of miR-629 by a hairpin miRNA inhibitor suppressed ccRCC cell motility and invasion. Mechanistically, miR-629 directly targeted tripartite motif-containing 33 (TRIM33), which inhibits the TGFβ/Smad signaling pathway. In clinical ccRCC specimens, downregulation of TRIM33 was observed with the association of both pathologic stages and grades. The miR-629 inhibitor significantly suppressed TGFβ-induced Smad activation by upregulating TRIM33 expression and subsequently inhibited the association of Smad2/3 and Smad4. Moreover, a miR-629 mimic enhanced the effect of TGFβ on the expression of epithelial–mesenchymal transition–related factors as well as on the motility and invasion in ccRCC cells. These findings identify miR-629 as a potent regulator of the TGFβ/Smad signaling pathway via TRIM33 in ccRCC.

Implications: This study suggests that miR-629 has biomarker potential through its ability to regulate TGFβ/Smad signaling and accelerate ccRCC cell motility and invasion. Mol Cancer Res; 13(3); 565–74. ©2014 AACR.
Data from Macrophages Promote Fibroblast Growth Factor Receptor-Driven Tumor Cell Migration and Invasion in a Cxcr2-Dependent Manner
Authors: Bohrer Laura R. , Schwertfeger Kathryn L.
Published: April 2023

Abstract
Infiltration of immune cells, specifically macrophages, into the tumor microenvironment has been linked to increased mammary tumor formation and progression. Activation of growth factor receptor signaling pathways within mammary epithelial cells, such as the fibroblast growth factor receptor 1 (FGFR1) pathway, induces recruitment of macrophages to the mammary epithelium. These macrophages promote increased epithelial cell proliferation and angiogenesis. However, the specific mechanisms by which these macrophages are regulated by the preneoplastic epithelial cells and the mechanisms of action of the macrophages within the developing FGFR1-driven tumor microenvironment remain unknown. In this study, we show that activation of inducible FGFR1 in mammary glands leads to decreased activity of the TGFβ/Smad3 pathway in macrophages associated with early stage lesions. Further studies show that macrophages have increased expression of inflammatory chemokines that bind Cxcr2 following exposure to conditioned media from mammary epithelial and tumor cells in which the FGF pathway had been activated. The increase in these ligands is inhibited following activation of the TGFβ pathway, suggesting that decreased TGFβ signaling contributes to the upregulation of these chemokines. Using coculture studies, we further show that macrophages are capable of promoting epithelial and tumor cell migration and invasion through activation of Cxcr2. These results indicate that macrophage-derived Cxcr2 ligands may be important for promoting mammary tumor formation regulated by FGFR signaling. Furthermore, these results suggest that targeting Cxcr2 may represent a novel therapeutic strategy for breast cancers that are associated with high levels of infiltrating macrophages. Mol Cancer Res; 10(10); 1294–305. ©2012 AACR.
Data from The Modulation of MicroRNAs by Type I IFN through the Activation of Signal Transducers and Activators of Transcription 3 in Human Glioma
Authors: Ohno Masasuke , Natsume Atsushi , Kondo Yutaka , Iwamizu Hidetaka , Motomura Kazuya , Toda Hiroshi , Ito Motokazu , Kato Takenori , Wakabayashi Toshihiko
Published: April 2023

Abstract
Type I IFNs are involved in double-stranded RNA responses. Here, we investigated the possibility that IFN-β may induce or downregulate cellular microRNAs (miRNA) in human neoplasms and thereby use the RNA interference system to show antitumor effects. Because of its known connection to glioma biology, we focused on miR-21 among seven miRNAs influenced by IFN-β. We analyzed the effect of IFN-β treatment on miR-21 expression in glioma cells and intracranial glioma xenografts. IFN-β treatment reduced miR-21 expression in glioma cells markedly, and IFN-β administration suppressed the growth of glioma-initiating cell–derived intracranial tumors. The levels of primary miR-21 gene transcripts, precursor miR-21, and mature miR-21 decreased 6 hours after the addition of IFN-β, indicating that the reduction in miR-21 levels was due to transcriptional suppression. We did reporter assays to elucidate the IFN-β–mediated suppression of miR-21; the addition of signal transducers and activators of transcription 3 (STAT3)–expressing vectors induced the IFN-β–mediated suppression of miR-21, whereas STAT3-inhibiting agents inhibited the miR-21 suppression. Thus, the results of our study show that the downregulation of miR-21 contributes to the antitumor effects of IFN-β and that miR-21 expression is negatively regulated by STAT3 activation. These results highlight the importance of understanding the transcriptional regulation of the miRNAs involved in oncogenesis. (Mol Cancer Res 2009;7(12):2022–30)
Data from PAX5α Enhances the Epithelial Behavior of Human Mammary Carcinoma Cells
Authors: Vidal Laurent J-P , Perry Jo K. , Vouyovitch Cecile M. , Pandey Vijay , Brunet-Dunand Severine E. , Mertani Hichem C. , Liu Dong-Xu , Lobie Peter E.
Published: April 2023

Abstract
Deregulated PAX5 expression has been associated with metastatic mammary carcinoma, although the precise role of PAX5 in cancer progression is unclear. Stable forced expression of PAX5α in the mammary carcinoma cell lines MCF-7 and MDA-MB-231 reduced cell cycle progression, cell survival, and anchorage-independent cell growth. In xenograft studies, forced expression of PAX5α was associated with a significant reduction in tumor volume. Furthermore, forced expression of PAX5α in mammary carcinoma cells resulted in altered cell morphology with resultant enhancement of epithelial cell characteristics. Morphologic changes were associated with localization of β-CATENIN at cell-cell junctions and with altered mRNA expression of mesenchymal markers in mammary carcinoma cells. In addition, forced expression of PAX5α in MCF-7 and MDA-MB-231 cells significantly reduced cell migration and invasion. Concomitantly, small interfering RNA–mediated depletion of PAX5α increased MCF-7 total cell number, cell motility, migration, and invasion. These studies show that PAX5α enhances the epithelial characteristics of mammary carcinoma cells, reminiscent of mesenchymal to epithelial transition. Mol Cancer Res; 8(3); 444–56
Data from Exon-Level Microarray Analyses Identify Alternative Splicing Programs in Breast Cancer
Authors: Lapuk Anna , Marr Henry , Jakkula Lakshmi , Pedro Helder , Bhattacharya Sanchita , Purdom Elizabeth , Hu Zhi , Simpson Ken , Pachter Lior , Durinck Steffen , Wang Nicholas , Parvin Bahram , Fontenay Gerald , Speed Terence , Garbe James , Stampfer Martha , Bayandorian Hovig , Dorton Shannon , Clark Tyson A. , Schweitzer Anthony , Wyrobek Andrew , Feiler Heidi , Spellman Paul , Conboy John , Gray Joe W.
Published: April 2023

Abstract
Protein isoforms produced by alternative splicing (AS) of many genes have been implicated in several aspects of cancer genesis and progression. These observations motivated a genome-wide assessment of AS in breast cancer. We accomplished this by measuring exon level expression in 31 breast cancer and nonmalignant immortalized cell lines representing luminal, basal, and claudin-low breast cancer subtypes using Affymetrix Human Junction Arrays. We analyzed these data using a computational pipeline specifically designed to detect AS with a low false-positive rate. This identified 181 splice events representing 156 genes as candidates for AS. Reverse transcription-PCR validation of a subset of predicted AS events confirmed 90%. Approximately half of the AS events were associated with basal, luminal, or claudin-low breast cancer subtypes. Exons involved in claudin-low subtype–specific AS were significantly associated with the presence of evolutionarily conserved binding motifs for the tissue-specific Fox2 splicing factor. Small interfering RNA knockdown of Fox2 confirmed the involvement of this splicing factor in subtype-specific AS. The subtype-specific AS detected in this study likely reflects the splicing pattern in the breast cancer progenitor cells in which the tumor arose and suggests the utility of assays for Fox-mediated AS in cancer subtype definition and early detection. These data also suggest the possibility of reducing the toxicity of protein-targeted breast cancer treatments by targeting protein isoforms that are not present in limiting normal tissues. Mol Cancer Res; 8(7); 961–74. ©2010 AACR.