bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Transcriptional Regulation of miR-31 by Oncogenic KRAS Mediates Metastatic Phenotypes by Repressing RASA1
Authors: Kent Oliver A. , Mendell Joshua T. , Rottapel Robert
Published: March 2024

Abstract
Activating KRAS mutations are nearly ubiquitous in pancreatic cancer occurring in more than 95% of clinical cases. miRNAs are small noncoding RNAs that regulate gene expression by binding sequences within the 3′UTRs of target mRNAs. An integral role for miRNAs in cancer pathogenesis is well established; however, the role of miRNAs in KRAS-mediated tumorigenesis is poorly characterized. Here it is demonstrated that expression of miR-31 is coupled to the expression of oncogenic KRAS and activity of the MAPK pathway. miR-31 is highly expressed in patient-derived xenografts and a panel of pancreatic and colorectal cancer cells harboring activating KRAS mutations. The miR-31 host gene is a large noncoding RNA that correlates with miR-31 expression and enabled identification of the putative miR-31 promoter. Using luciferase reporters, a minimal RAS-responsive miR-31 promoter was found to drive robust luciferase activity dependent on expression of mutant KRAS and the transcription factor ELK1. Furthermore, ELK1 interacts directly with the endogenous miR-31 promoter in a MAPK-dependent manner. Expression of enforced miR-31 significantly enhanced invasion and migration of multiple pancreatic cancer cells resulting from the activation of RhoA through regulation of the miR-31 target gene RASA1. Importantly, acute knockdown of RASA1 phenocopied enforced miR-31 expression on the migratory behavior of pancreatic cancer cells through increased RhoA activation.

Implications: Oncogenic KRAS can activate Rho through the miR-31–mediated regulation of RASA1 indicating miR-31 acts as a KRAS effector to modulate invasion and migration in pancreatic cancer. Mol Cancer Res; 14(3); 267–77. ©2016 AACR.
Data from DRO1 Inactivation Drives Colorectal Carcinogenesis in ApcMin/+ Mice
Authors: Grill Jessica I. , Neumann Jens , Herbst Andreas , Hiltwein Felix , Ofner Andrea , Marschall Maximilian K. , Wolf Eckhard , Kirchner Thomas , Göke Burkhard , Schneider Marlon R. , Kolligs Frank T.
Published: March 2024

Abstract
Colorectal cancer develops from adenomatous precursor lesions by a multistep process that involves several independent mutational events in oncogenes and tumor suppressor genes. Inactivation of the adenomatous polyposis coli (APC) tumor suppressor gene is an early event and a prerequisite for the development of human colorectal adenoma. Previous in vitro studies identified DRO1 (CCDC80) to be a putative tumor suppressor gene that is negatively regulated in colorectal cancers and downregulated upon neoplastic transformation of epithelial cells. To investigate the in vivo role of DRO1 in colorectal carcinogenesis, a constitutive DRO1 knockout mouse model was generated. Disruption of DRO1 did not result in spontaneous intestinal tumor formation, consistent with the notion that DRO1 might have a role in suppressing the development of colon tumors in ApcMin/+ mice, a widely used model for studying the role of APC in intestinal tumorigenesis that is hampered by the fact that mice predominantly develop adenomas in the small intestine and not in the colon. Here, deletion of DRO1 in ApcMin/+ mice results in earlier death, a dramatically increased colonic tumor burden, and frequent development of colorectal carcinoma. Furthermore, enhanced phosphorylation of ERK1/2 is observed in colon epithelium and tumors from DRO1 knockout mice. Thus, this study reveals that inactivation of DRO1 is required for colorectal carcinogenesis in the ApcMin/+ mouse and establishes a new mouse model for the study of colorectal cancer.

Implications: This report characterizes a new mouse model for the study of colorectal cancer and establishes DRO1 (CCDC80) as a tumor suppressor via a mechanism involving ERK phosphorylation. Mol Cancer Res; 12(11); 1655–62. ©2014 AACR.
Data from p53 Deletion or Hotspot Mutations Enhance mTORC1 Activity by Altering Lysosomal Dynamics of TSC2 and Rheb
Authors: Agarwal Stuti , Bell Catherine M. , Taylor Shirley M. , Moran Richard G.
Published: March 2024

Abstract
The activity of mammalian target of rapamycin complex 1 (mTORC1) is frequently enhanced in carcinomas, an effect thought to contribute to the malignant phenotype. Here, it is demonstrated that either deletion or mutation of TP53 in colon or lung carcinoma cells substantially enhances mTORC1 kinase activity by an effect downstream of and independent of AMPK. Mechanistically, it was determined that loss or mutation of p53 decreased expression of TSC2 and Sestrin2 (SESN2). Complementation of p53 null cells with TSC2 or Sestrin2 reduced mTORC1 activity to levels found in p53 wild-type (wt) cells, whereas their genetic depletion enhanced mTORC1 activity in p53 wt cells. However, the primary causal event in enhanced mTORC1 activity upon loss of p53 appeared to be a diminished distribution of TSC2 to lysosomal membranes containing mTOR. Subsequently, there was increased Rheb in the lysosomal compartment, and a higher mTOR association with Raptor. Transfection of TSC2 into p53 null cells replaced TSC2 and diminished Rheb at the lysosome, recapitulating cells with wt p53. In contrast, transfection of Sestrin2 decreased mTOR in lysosomes, but the lower levels of Sestrin2 in p53 null cells did not change lysosomal mTOR. In summary, loss of the transcriptional activity of p53, either by deletion or by key mutations in the DNA-binding domain, diminishes expression of TSC2 and Sestrin2, thus, shifting membrane-bound TSC2 out of lysosomal membranes, increasing lysosomal Rheb and increasing the kinase activity of mTORC1.

Implications: This study establishes that loss of p53 function decreases lysosomal TSC2 and increases lysosomal Rheb resulting in hyperactive mTORC1, findings that are consistent with a more malignant phenotype. Mol Cancer Res; 14(1); 66–77. ©2015 AACR.
Data from Pancreatic Neuroendocrine Tumors and EMT Behavior Are Driven by the CSC Marker DCLK1
Authors: Ikezono Yu , Koga Hironori , Akiba Jun , Abe Mitsuhiko , Yoshida Takafumi , Wada Fumitaka , Nakamura Toru , Iwamoto Hideki , Masuda Atsutaka , Sakaue Takahiko , Yano Hirohisa , Tsuruta Osamu , Torimura Takuji
Published: March 2024

Abstract
Doublecortin-like kinase 1 (DCLK1), a marker for intestinal and pancreatic cancer stem cells, is highly expressed in neuroblastomas. This study was conducted to assess DCLK1 expression levels in pancreatic neuroendocrine tumor (PNET) tissues and to explore the roles of this molecule in clinical tissue from multiple PNET patients, cells (BON1, QGP1, and CM) and tumor xenografts. Immunohistochemically, all PNET tissues highly and diffusely expressed DCLK1 as a full-length isoform, identical to that detected in primary liver NETs. A DCLK1-overexpressing PNET cell line (QGP1-DCLK1) exhibited epithelial–mesenchymal transition (EMT)-related gene signatures, and robust upregulation of Slug (SNAI2), N-Cadherin (CDH2), and Vimentin (VIM) was validated by real-time PCR and immunoblotting. QGP1-DCLK1 cells had increased cell migration in a wound-healing assay and formed significantly larger xenograft tumors in nude mice. The factors involved in the formation of the fast-growing tumors included p-FAK (on Tyr925), p-ERK1/2, p-AKT, Paxillin, and Cyclin D1, which upon knockdown or pharmacologic inhibition of DCLK1 abolished the expression of these molecules. In conclusion, robust and ubiquitous expression of DCLK1 was first demonstrated here in human PNET tissue specimens and cells. DCLK1 characterized the PNET cell behavior, inducing p-FAK/SLUG-mediated EMT. These findings suggest the possibility of developing novel therapeutic strategies against PNETs by targeting DCLK1.

Implications: Evidence here reveals that human PNETs diffusely and robustly express the cancer stem cell marker DCLK1, which drives SLUG-mediated EMT, and suggests that NETs share biological features for druggable targets with other tumors, including neuroblastoma that also highly expresses DCLK1. Mol Cancer Res; 15(6); 744–52. ©2017 AACR.
Data from Differential Expression of OATP1B3 Mediates Unconjugated Testosterone Influx
Authors: Sissung Tristan M. , Ley Ariel M. , Strope Jonathan D. , McCrea Edel M. , Beedie Shaunna , Peer Cody J. , Shukla Suneet , van Velkinburgh Jennifer , Reece Kelie , Troutman Sarah , Campbell Tessa , Fernandez Elena , Huang Phoebe , Smith Jordan , Thakkar Nilay , Venzon David J. , Brenner Stefan , Lee Wooin , Merino Maria , Luo Ji , Jager Walter , Price Douglas K. , Chau Cindy H. , Figg William D.
Published: March 2024

Abstract
Castration-resistant prostate cancer (CRPC) has greater intratumoral testosterone concentrations than similar tumors from eugonadal men; simple diffusion does not account for this observation. This study was undertaken to ascertain the androgen uptake kinetics, functional, and clinical relevance of de novo expression of the steroid hormone transporter OATP1B3 (SLCO1B3). Experiments testing the cellular uptake of androgens suggest that testosterone is an excellent substrate of OATP1B3 (Km = 23.2 μmol/L; Vmax = 321.6 pmol/mg/minute), and cells expressing a doxycycline-inducible SLCO1B3 construct had greater uptake of a clinically relevant concentration of 3H-testosterone (50 nmol/L; 1.6-fold, P = 0.0027). When compared with Slco1b2 (−/−) mice, Slco1b2 (−/−)/hSLCO1B3 knockins had greater hepatic uptake (15% greater AUC, P = 0.0040) and lower plasma exposure to 3H-testosterone (17% lower AUC, P = 0.0030). Of 82 transporters genes, SLCO1B3 is the second-most differentially expressed transporter in CRPC cell lines (116-fold vs. androgen-sensitive cells), with a differentially spliced cancer-type ct-SLCO1B3 making up the majority of SLCO1B3 expression. Overexpression of SLCO1B3 in androgen-responsive cells results in 1.5- to 2-fold greater testosterone uptake, whereas siRNA knockdown of SLCO1B3 in CRPC cells did not change intracellular testosterone concentration. Primary human prostate tumors express SLCO1B3 to a greater extent than ct-SLCO1B3 (26% of total SLCO1B3 expression vs. 0.08%), suggesting that androgen uptake in these tumor cells also is greater. Non-liver tumors do not differentially express SLCO1B3.

Implications: This study suggests that de novo OATP1B3 expression in prostate cancer drives greater androgen uptake and is consistent with previous observations that greater OATP1B3 activity results in the development of androgen deprivation therapy resistance and shorter overall survival. Mol Cancer Res; 15(8); 1096–105. ©2017 AACR.
Data from Differential Expression of Stress and Immune Response Pathway Transcripts and miRNAs in Normal Human Endothelial Cells Subjected to Fractionated or Single-Dose Radiation
Authors: Palayoor Sanjeewani T. , John-Aryankalayil Molykutty , Makinde Adeola Y. , Falduto Michael T. , Magnuson Scott R. , Coleman C. Norman
Published: March 2024

Abstract
Although modern radiotherapy technologies can precisely deliver higher doses of radiation to tumors, thus, reducing overall radiation exposure to normal tissues, moderate dose, and normal tissue toxicity still remains a significant limitation. The present study profiled the global effects on transcript and miR expression in human coronary artery endothelial cells using single-dose irradiation (SD, 10 Gy) or multifractionated irradiation (MF, 2 Gy × 5) regimens. Longitudinal time points were collected after an SD or final dose of MF irradiation for analysis using Agilent Human Gene Expression and miRNA microarray platforms. Compared with SD, the exposure to MF resulted in robust transcript and miR expression changes in terms of the number and magnitude. For data analysis, statistically significant mRNAs (2-fold) and miRs (1.5-fold) were processed by Ingenuity Pathway Analysis to uncover miRs associated with target transcripts from several cellular pathways after irradiation. Interestingly, MF radiation induced a cohort of mRNAs and miRs that coordinate the induction of immune response pathway under tight regulation. In addition, mRNAs and miRs associated with DNA replication, recombination and repair, apoptosis, cardiovascular events, and angiogenesis were revealed.

Implications: Radiation-induced alterations in stress and immune response genes in endothelial cells contribute to changes in normal tissue and tumor microenvironment, and affect the outcome of radiotherapy. Mol Cancer Res; 12(7); 1002–15. ©2014 AACR.
Data from EGFR Mutations Compromise Hypoxia-Associated Radiation Resistance through Impaired Replication Fork–Associated DNA Damage Repair
Authors: Saki Mohammad , Makino Haruhiko , Javvadi Prashanthi , Tomimatsu Nozomi , Ding Liang-Hao , Clark Jennifer E. , Gavin Elaine , Takeda Kenichi , Andrews Joel , Saha Debabrata , Story Michael D. , Burma Sandeep , Nirodi Chaitanya S.
Published: March 2024

Abstract
EGFR signaling has been implicated in hypoxia-associated resistance to radiation or chemotherapy. Non–small cell lung carcinomas (NSCLC) with activating L858R or ΔE746-E750 EGFR mutations exhibit elevated EGFR activity and downstream signaling. Here, relative to wild-type (WT) EGFR, mutant (MT) EGFR expression significantly increases radiosensitivity in hypoxic cells. Gene expression profiling in human bronchial epithelial cells (HBEC) revealed that MT-EGFR expression elevated transcripts related to cell cycle and replication in aerobic and hypoxic conditions and downregulated RAD50, a critical component of nonhomologous end joining and homologous recombination DNA repair pathways. NSCLCs and HBEC with MT-EGFR revealed elevated basal and hypoxia-induced γ-H2AX–associated DNA lesions that were coincident with replication protein A in the S-phase nuclei. DNA fiber analysis showed that, relative to WT-EGFR, MT-EGFR NSCLCs harbored significantly higher levels of stalled replication forks and decreased fork velocities in aerobic and hypoxic conditions. EGFR blockade by cetuximab significantly increased radiosensitivity in hypoxic cells, recapitulating MT-EGFR expression and closely resembling synthetic lethality of PARP inhibition.

Implications: This study demonstrates that within an altered DNA damage response of hypoxic NSCLC cells, mutant EGFR expression, or EGFR blockade by cetuximab exerts a synthetic lethality effect and significantly compromises radiation resistance in hypoxic tumor cells. Mol Cancer Res; 15(11); 1503–16. ©2017 AACR.
Data from Synthetic Lethality in PTEN-Mutant Prostate Cancer Is Induced by Combinatorial PI3K/Akt and BCL-XL Inhibition
Authors: Ren Wenying , Joshi Raghav , Mathew Paul
Published: March 2024

Abstract
The bone-conserved metastatic phenotype of prostate cancer is a prototype of nonrandom metastatic behavior. Adhesion of prostate cancer cells to fibronectin via the integrin α5 (ITGA5) has been proposed as a candidate bone marrow niche localization mechanism. We hypothesized that the mechanisms whereby ITGA5 regulates the adhesion-mediated survival of prostate cancer cells will define novel therapeutic approaches. ITGA5 shRNA reduced expression of BCL-2 family members and induced apoptosis in PC-3 cells. In these PTEN-mutant cells, pharmacologic inhibition of the PI3K signaling pathway in combination with ITGA5 knockdown enhanced apoptosis. Chemical parsing studies with BH3 mimetics indicated that PI3K/Akt inhibition in combination with BCL-XL–specific inhibition induces synergistic apoptosis specifically in PTEN-mutant prostate cancer cells, whereas single-agent PI3K/Akt inhibitors did not. Given the importance of PTEN loss in the progression of prostate and other cancers, synthetic lethality induced by combinatorial PI3K/Akt and BCL-XL inhibition represents a valuable therapeutic strategy.

Implications: Activation of the PI3K pathway through PTEN loss represents a major molecular pathway in the progression of prostate and other cancers. This study defines a synthetic lethal therapeutic combination with significant translational potential.

Overview: Synthetic lethality in PTEN-mutant prostate cancer cells with combined PI3K/Akt and BCL-XL inhibition. PTEN-mutant prostate cancer cells expressing ITGA5 bind to fibronectin in the putative bone marrow niche and transduce survival signals to BCL-XL. Additional PTEN-regulated signals independent of the PI3K/Akt pathway likely feed into the BCL-XL–regulated survival program to explain synthetic lethality observed with the combination.

Visual Overview: http://mcr.aacrjournals.org/content/early/2016/12/02/1541-7786.MCR-16-0202/F1.large.jpg. Mol Cancer Res; 14(12); 1176–81. ©2016 AACR.
Data from TNF Signaling through RIP1 Kinase Enhances SN38-Induced Death in Colon Adenocarcinoma
Authors: Cabal-Hierro Lucia , O'Dwyer Peter J.
Published: March 2024

Abstract
Elucidation of TNF-directed mechanisms for cell death induction and maintenance of tumor growth has revealed a role for receptor-interacting protein kinases 1 and 3 (RIPK1/RIP1 and RIPK3/RIP3), components of the necrosome complex, as determinants of cell fate. Here, the participation of TNF signaling was analyzed with regard to the cytotoxic action of different DNA-damaging agents in a panel of colon cancer cells. While most of these cell lines were insensitive to TNF, combination with these drugs increased sensitivity by inducing cell death and DNA damage, especially in the case of the topoisomerase inhibitor SN38. Changes in levels of RIP1 and RIP3 occurred following monotherapy with SN38 or in combination with TNF. Downregulation of RIP1 resulted in increased resistance to SN38, implying a requirement for RIP1 in mediating cytotoxicity through the TNF/TNFR signaling pathway. Downregulation of RIP1 in a xenograft model impaired tumor growth inhibition from SN38 treatment, suggesting the potential of RIP1 to determine the clinical outcome of irinotecan treatment. These results indicate that TNF plays a key role in determining the cytotoxic effectiveness of SN38 in colorectal cancer and suggests a re-evaluation of TNF-based interventions to enhance therapeutic efficacy.

Implications: The capacity of RIP1 to influence drug sensitivity suggests RIP1 may have biomarker potential. Mol Cancer Res; 15(4); 395–404. ©2017 AACR.
Data from Discovery-Based Protein Expression Profiling Identifies Distinct Subgroups and Pathways in Leiomyosarcomas
Authors: Kirik Ufuk , Hansson Karin , Krogh Morten , Jönsson Mats , Nilbert Mef , James Peter , Carneiro Ana
Published: March 2024

Abstract
Soft tissue sarcomas (STS) are malignant tumors of mesenchymal origin. A substantial portion of these tumors exhibits complex karyotypes and lack characterized chromosomal aberrations. Owing to such properties, both histopathologic and molecular classification of these tumors has been a significant challenge. This study examines the protein expression of a large number of human STS, including subtype heterogeneity, using two-dimensional gel proteomics. In addition, detailed proteome profiles of a subset of pleomorphic STS specimens using an in-depth mass-spectrometry approach identified subgroups within the leiomyosarcomas with distinct protein expression patterns. Pathways analysis indicates that key biologic nodes like apoptosis, cytoskeleton remodeling, and telomere regulation are differentially regulated among these subgroups. Finally, investigating the similarities between protein expression of leiomyosarcomas and undifferentiated pleomorphic sarcomas (UPS) revealed similar protein expression profiles for these tumors, in comparison with pleomorphic leiomyosarcomas.

Implications: These results suggest that UPS tumors share a similar lineage as leiomyosarcomas and are likely to originate from different stages of differentiation from mesenchymal stem cells to smooth muscle cells. Mol Cancer Res; 12(12); 1729–39. ©2014 AACR.
Data from NEDD9 Regulates Actin Dynamics through Cortactin Deacetylation in an AURKA/HDAC6–Dependent Manner
Authors: Kozyreva Varvara K. , McLaughlin Sarah L. , Livengood Ryan H. , Calkins Robin A. , Kelley Laura C. , Rajulapati Anuradha , Ice Ryan J. , Smolkin Matthew B. , Weed Scott A. , Pugacheva Elena N.
Published: March 2024

Abstract
The prometastatic protein NEDD9 (neural precursor cell expressed, developmentally downregulated 9) is highly expressed in many cancers and is required for mesenchymal individual cell migration and progression to the invasive stage. Nevertheless, the molecular mechanisms of NEDD9-driven migration and the downstream targets effecting metastasis are not well defined. In the current study, knockdown of NEDD9 in highly metastatic tumor cells drastically reduces their migratory capacity due to disruption of actin dynamics at the leading edge. Specifically, NEDD9 deficiency leads to a decrease in the persistence and stability of lamellipodial protrusions similar to knockdown of cortactin (CTTN). Mechanistically, it was shown that NEDD9 binds to and regulates acetylation of CTTN in an Aurora A kinase (AURKA)/HDAC6–dependent manner. The knockdown of NEDD9 or AURKA results in an increase in the amount of acetylated CTTN and a decrease in the binding of CTTN to F-actin. Overexpression of the deacetylation mimicking (9KR) mutant of CTTN is sufficient to restore actin dynamics at the leading edge and migration proficiency of the tumor cells. Inhibition of AURKA and HDAC6 activity by alisertib and Tubastatin A in xenograft models of breast cancer leads to a decrease in the number of pulmonary metastases. Collectively, these findings identify CTTN as the key downstream component of NEDD9-driven migration and metastatic phenotypes.

Implications: This study provides a mechanistic platform for therapeutic interventions based on AURKA and HDAC6 inhibition for patients with metastatic breast cancer to prevent and/or eradicate metastases. Mol Cancer Res; 12(5); 681–93. ©2014 AACR.
Data from Defining ATM-Independent Functions of the Mre11 Complex with a Novel Mouse Model
Authors: Balestrini Alessia , Nicolas Laura , Yang-lott Katherine , Guryanova Olga A. , Levine Ross L. , Bassing Craig H. , Chaudhuri Jayanta , Petrini John H.J.
Published: March 2024

Abstract
The Mre11 complex (Mre11, Rad50, and Nbs1) occupies a central node of the DNA damage response (DDR) network and is required for ATM activation in response to DNA damage. Hypomorphic alleles of MRE11 and NBS1 confer embryonic lethality in ATM-deficient mice, indicating that the complex exerts ATM-independent functions that are essential when ATM is absent. To delineate those functions, a conditional ATM allele (ATMflox) was crossed to hypomorphic NBS1 mutants (Nbs1ΔB/ΔB mice). Nbs1ΔB/ΔB Atm−/− hematopoietic cells derived by crossing to vavcre were viable in vivo. Nbs1ΔB/ΔB Atm−/− VAV mice exhibited a pronounced defect in double-strand break repair and completely penetrant early onset lymphomagenesis. In addition to repair defects observed, fragile site instability was noted, indicating that the Mre11 complex promotes genome stability upon replication stress in vivo. The data suggest combined influences of the Mre11 complex on DNA repair, as well as the responses to DNA damage and DNA replication stress.

Implications: A novel mouse model was developed, by combining a vavcre-inducible ATM knockout mouse with an NBS1 hypomorphic mutation, to analyze ATM-independent functions of the Mre11 complex in vivo. These data show that the DNA repair, rather than DDR signaling functions of the complex, is acutely required in the context of ATM deficiency to suppress genome instability and lymphomagenesis. Mol Cancer Res; 14(2); 185–95. ©2015 AACR.
Data from Stromal Senescence By Prolonged CDK4/6 Inhibition Potentiates Tumor Growth
Authors: Guan Xiangnan , LaPak Kyle M. , Hennessey Rebecca C. , Yu Christina Y. , Shakya Reena , Zhang Jianying , Burd Christin E.
Published: March 2024

Abstract
Senescent cells within the tumor microenvironment (TME) adopt a proinflammatory, senescence-associated secretory phenotype (SASP) that promotes cancer initiation, progression, and therapeutic resistance. Here, exposure to palbociclib (PD-0332991), a CDK4/6 inhibitor, induces senescence and a robust SASP in normal fibroblasts. Senescence caused by prolonged CDK4/6 inhibition is DNA damage–independent and associated with Mdm2 downregulation, whereas the SASP elicited by these cells is largely reliant upon NF-κB activation. Based upon these observations, it was hypothesized that the exposure of nontransformed stromal cells to PD-0332991 would promote tumor growth. Ongoing clinical trials of CDK4/6 inhibitors in melanoma prompted a validation of this hypothesis using a suite of genetically defined melanoma cells (i.e., Ras mutant, Braf mutant, and Ras/Braf wild-type). When cultured in the presence of CDK4/6i-induced senescent fibroblasts, melanoma cell lines exhibited genotype-dependent proliferative responses. However, in vivo, PD-0332991–treated fibroblasts enhanced the growth of all melanoma lines tested and promoted the recruitment of Gr-1–positive immune cells. These data indicate that prolonged CDK4/6 inhibitor treatment causes normal fibroblasts to enter senescence and adopt a robust SASP. Such senescent cells suppress the antitumor immune response and promote melanoma growth in immunocompetent, in vivo models.

Implications: The ability of prolonged CDK4/6 inhibitor treatment to induce cellular senescence and a robust SASP in primary cells may hinder therapeutic efficacy and promote long-term, gerontogenic consequences that should be considered in clinical trials aiming to treat melanoma and other cancer types. Mol Cancer Res; 15(3); 237–49. ©2016 AACR.
Data from An Integrative Approach Uncovers Biomarkers that Associate with Clinically Relevant Disease Outcomes in Vulvar Carcinoma
Authors: Lavorato-Rocha Andre M. , Akagi Erica M. , de Melo Maia Beatriz , Rodrigues Iara S. , Botelho Mayara Caroline Silva , Marchi Fabio A. , Fernandes Gabriel , Baiocchi Glauco , Soares Fernando A. , Rogatto Silvia Regina , Sato-Kuwabara Yukie , Rocha Rafael M.
Published: March 2024

Abstract
Vulvar squamous cell carcinoma (VSCC) is a rare disease that has a high mortality rate (∼40%). However, little is known about its molecular signature. Therefore, an integrated genomics approach, based on comparative genome hybridization (aCGH) and genome-wide expression (GWE) array, was performed to identify driver genes in VSCC. To achieve that, DNA and RNA were extracted from frozen VSCC clinical specimens and examined by aCGH and GWE array, respectively. On the basis of the integration of data using the CONEXIC algorithm, PLXDC2 and GNB3 were validated by RT-qPCR. The expression of these genes was then analyzed by IHC in a large set of formalin-fixed paraffin-embedded specimens. These analyses identified 47 putative drivers, 46 of which were characterized by copy number gains that were concomitant with overexpression and one with a copy number loss and downregulation. Two of these genes, PLXDC2 and GNB3, were selected for further validation: PLXDC2 was downregulated and GNB3 was overexpressed compared with non-neoplastic tissue. By IHC, both proteins were ubiquitously expressed throughout vulvar tissue. High expression of GNB3 and low PLXDC2 immunostaining in the same sample was significantly associated with less lymph node metastasis and greater disease-free survival. On the basis of a robust methodology never used before for VSCC evaluation, two novel prognostic markers in vulvar cancer are identified: one with favorable prognosis (GNB3) and the other with unfavorable prognosis (PLXDC2).

Implications: This genomics study reveals markers that associate with prognosis and may provide guidance for better treatment in vulvar cancer. Mol Cancer Res; 14(8); 720–9. ©2016 AACR.
Data from AMPKα2 Regulates Bladder Cancer Growth through SKP2-Mediated Degradation of p27
Authors: Kopsiaftis Stavros , Sullivan Katie L. , Garg Isha , Taylor John A. , Claffey Kevin P.
Published: March 2024

Abstract
AMP-activated protein kinase (AMPK) is the central metabolic regulator of the cell and controls energy consumption based upon nutrient availability. Due to its role in energy regulation, AMPK has been implicated as a barrier for cancer progression and is suppressed in multiple cancers. To examine whether AMPK regulates bladder cancer cell growth, HTB2 and HT1376 bladder cells were treated with an AMPK activator, 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR). AICAR treatment reduced proliferation and induced the expression of p27Kip1 (CDKN1B), which was mediated through an mTOR-dependent mechanism. Interestingly, AMPKα2 knockdown resulted in reduced p27 levels, whereas AMPKα1 suppression did not. To further determine the exact mechanism by which AMPKa2 regulates p27, HTB2 and HT1376 cells were transduced with an shRNA targeting AMPKα2. Stable knockdown of AMPKα2 resulted in increased proliferation and decreased p27 protein. The reduced p27 protein was determined to be dependent upon SKP2. Additionally, loss of AMPKα2 in a xenograft and a chemical carcinogen model of bladder cancer resulted in larger tumors with less p27 protein and high SKP2 levels. Consistent with the regulation observed in the bladder cancer model systems, a comprehensive survey of human primary bladder cancer clinical specimens revealed low levels of AMPKα2 and p27 and high levels of SKP2.

Implications: These results highlight the contribution of AMPKα2 as a mechanism for controlling bladder cancer growth by regulating proliferation through mTOR suppression and induction of p27 protein levels, thus indicating how AMPKα2 loss may contribute to tumorigenesis. Mol Cancer Res; 14(12); 1182–94. ©2016 AACR.
Data from High-Affinity Internalizing Human scFv-Fc Antibody for Targeting FGFR1-Overexpressing Lung Cancer
Authors: Sokolowska-Wedzina Aleksandra , Chodaczek Grzegorz , Chudzian Julia , Borek Aleksandra , Zakrzewska Malgorzata , Otlewski Jacek
Published: March 2024

Abstract
Targeted delivery of anticancer drugs using antibodies specific for tumor-associated antigens represents one of the most important approaches in current immuno-oncology research. Fibroblast growth factor receptor 1 (FGFR1) has been demonstrated to be a high-frequency targetable oncogene specific for smoking-associated lung cancers, present in over 20% of lung squamous cell carcinoma cases. This report describes the generation of a potent, fully human antibody fragment in scFv-Fc format efficiently targeting FGFR1. Antibody phage display was used to select high-affinity scFv antibody fragments against the extracellular domain of FGFR1(IIIc). Enzyme immunoassay (ELISA) and surface plasmon resonance (SPR) analysis were used for antibody screening and characterization. The best binder (named D2) was cloned to diabody and Fc fusion formats. All D2 antibodies demonstrated high affinity for FGFR1 with dissociation constants of 18 nmol/L (scFvD2), 0.82 nmol/L (scFvD2 diabody), and 0.59 nmol/L (scFvD2-Fc). scFvD2 was found to be exquisitely selective for FGFR1 versus other FGFR family members and bound FGFR1 even in the presence of its natural ligand FGF2, as shown by competitive analysis. Confocal microscopy revealed that scFvD2-Fc was specifically and rapidly internalized by a panel of cell lines overexpressing FGFR1. Finally, it was demonstrated that scFvD2-Fc mediated specific delivery of a cytotoxic payload into lung cancer cells harboring oncogenic FGFR1 gene amplifications.

Implications: This study reports a highly specific internalizing antibody fragment that can serve as a therapeutic targeting agent for efficient delivery of cytotoxic drugs into FGFR1-positive lung cancer cells. Mol Cancer Res; 15(8); 1040–50. ©2017 AACR.
Data from Active FOXO1 Is a Key Determinant of Isoform-Specific Progesterone Receptor Transactivation and Senescence Programming
Authors: Diep Caroline H. , Knutson Todd P. , Lange Carol A.
Published: March 2024

Abstract
Progesterone promotes differentiation coupled to proliferation and prosurvival in the breast, but inhibits estrogen-driven growth in the reproductive tract and ovaries. Herein, it is demonstrated, using progesterone receptor (PR) isoform-specific ovarian cancer model systems, that PR-A and PR-B promote distinct gene expression profiles that differ from PR-driven genes in breast cancer cells. In ovarian cancer models, PR-A primarily regulates genes independently of progestin, while PR-B is the dominant ligand-dependent isoform. Notably, FOXO1 and the PR/FOXO1 target gene p21 (CDKN1A) are repressed by PR-A, but induced by PR-B. In the presence of progestin, PR-B, but not PR-A, robustly induced cellular senescence via FOXO1-dependent induction of p21 and p15 (CDKN2B). Chromatin immunoprecipitation (ChIP) assays performed on PR isoform–specific cells demonstrated that while each isoform is recruited to the same PRE-containing region of the p21 promoter in response to progestin, only PR-B elicits active chromatin marks. Overexpression of constitutively active FOXO1 in PR-A–expressing cells conferred robust ligand-dependent upregulation of the PR-B target genes GZMA, IGFBP1, and p21, and induced cellular senescence. In the presence of endogenous active FOXO1, PR-A was phosphorylated on Ser294 and transactivated PR-B at PR-B target genes; these events were blocked by the FOXO1 inhibitor (AS1842856). PR isoform–specific regulation of the FOXO1/p21 axis recapitulated in human primary ovarian tumor explants treated with progestin; loss of progestin sensitivity correlated with high AKT activity.

Implications: This study indicates FOXO1 as a critical component for progesterone signaling to promote cellular senescence and reveals a novel mechanism for transcription factor control of hormone sensitivity. Mol Cancer Res; 14(2); 141–62. ©2015 AACR.
Data from Oncofetal Chondroitin Sulfate Glycosaminoglycans Are Key Players in Integrin Signaling and Tumor Cell Motility
Authors: Clausen Thomas Mandel , Pereira Marina Ayres , Al Nakouzi Nader , Oo Htoo Zarni , Agerbæk Mette Ø , Lee Sherry , Ørum-Madsen Maj Sofie , Kristensen Anders Riis , El-Naggar Amal , Grandgenett Paul M. , Grem Jean L. , Hollingsworth Michael A. , Holst Peter J. , Theander Thor , Sorensen Poul H. , Daugaard Mads , Salanti Ali
Published: March 2024

Abstract
Many tumors express proteoglycans modified with oncofetal chondroitin sulfate glycosaminoglycan chains (ofCS), which are normally restricted to the placenta. However, the role of ofCS in cancer is largely unknown. The function of ofCS in cancer was analyzed using the recombinant ofCS-binding VAR2CSA protein (rVAR2) derived from the malaria parasite, Plasmodium falciparum. We demonstrate that ofCS plays a key role in tumor cell motility by affecting canonical integrin signaling pathways. Binding of rVAR2 to tumor cells inhibited the interaction of cells with extracellular matrix (ECM) components, which correlated with decreased phosphorylation of Src kinase. Moreover, rVAR2 binding decreased migration, invasion, and anchorage-independent growth of tumor cells in vitro. Mass spectrometry of ofCS-modified proteoglycan complexes affinity purified from tumor cell lines on rVAR2 columns revealed an overrepresentation of proteins involved in cell motility and integrin signaling, such as integrin-β1 (ITGB1) and integrin-α4 (ITGA4). Saturating concentrations of rVAR2 inhibited downstream integrin signaling, which was mimicked by knockdown of the core chondroitin sulfate synthesis enzymes β-1,3-glucuronyltransferase 1 (B3GAT1) and chondroitin sulfate N-acetylgalactosaminyltransferase 1 (CSGALNACT1). The ofCS modification was highly expressed in both human and murine metastatic lesions in situ and preincubation or early intravenous treatment of tumor cells with rVAR2 inhibited seeding and spreading of tumor cells in mice. This was associated with a significant increase in survival of the animals. These data functionally link ofCS modifications with cancer cell motility and further highlights ofCS as a novel therapeutic cancer target.

Implications: The cancer-specific expression of ofCS aids in metastatic phenotypes and is a candidate target for therapy. Mol Cancer Res; 14(12); 1288–99. ©2016 AACR.
Data from RAD51 and BRCA2 Enhance Oncolytic Adenovirus Type 5 Activity in Ovarian Cancer
Authors: Tookman Laura A. , Browne Ashley K. , Connell Claire M. , Bridge Gemma , Ingemarsdotter Carin K. , Dowson Suzanne , Shibata Atsushi , Lockley Michelle , Martin Sarah A. , McNeish Iain A.
Published: March 2024

Abstract
Homologous recombination (HR) function is critically important in high-grade serous ovarian cancer (HGSOC). HGSOC with intact HR has a worse prognosis and is less likely to respond to platinum chemotherapy and PARP inhibitors. Oncolytic adenovirus, a novel therapy for human malignancies, stimulates a potent DNA damage response that influences overall antitumor activity. Here, the importance of HR was investigated by determining the efficacy of adenovirus type 5 (Ad5) vectors in ovarian cancer. Using matched BRCA2-mutant and wild-type HGSOC cells, it was demonstrated that intact HR function promotes viral DNA replication and augments overall efficacy, without influencing viral DNA processing. These data were confirmed in a wider panel of HR competent and defective ovarian cancer lines. Mechanistically, both BRCA2 and RAD51 localize to viral replication centers within the infected cell nucleus and that RAD51 localization occurs independently of BRCA2. In addition, a direct interaction was identified between RAD51 and adenovirus E2 DNA binding protein. Finally, using functional assays of HR competence, despite inducing degradation of MRE11, Ad5 infection does not alter cellular ability to repair DNA double-strand break damage via HR. These data reveal that Ad5 redistributes critical HR components to viral replication centers and enhances cytotoxicity.

Implications: Oncolytic adenoviral therapy may be most clinically relevant in tumors with intact HR function. Mol Cancer Res; 14(1); 44–55. ©2015 AACR.
Data from ELF4 Is a Target of miR-124 and Promotes Neuroblastoma Proliferation and Undifferentiated State
Authors: Kosti Adam , Du Liqin , Shivram Haridha , Qiao Mei , Burns Suzanne , Garcia Juan Gabriel , Pertsemlidis Alexander , Iyer Vishwanath R. , Kokovay Erzsebet , Penalva Luiz O.F.
Published: March 2024

Abstract
13-Cis-retinoic acid (RA) is typically used in postremission maintenance therapy in patients with neuroblastoma. However, side effects and recurrence are often observed. We investigated the use of miRNAs as a strategy to replace RA as promoters of differentiation. miR-124 was identified as the top candidate in a functional screen. Genomic target analysis indicated that repression of a network of transcription factors (TF) could be mediating most of miR-124's effect in driving differentiation. To advance miR-124 mimic use in therapy and better define its mechanism of action, a high-throughput siRNA morphologic screen focusing on its TF targets was conducted and ELF4 was identified as a leading candidate for miR-124 repression. By altering its expression levels, we showed that ELF4 maintains neuroblastoma in an undifferentiated state and promotes proliferation. Moreover, ELF4 transgenic expression was able to counteract the neurogenic effect of miR-124 in neuroblastoma cells. With RNA sequencing, we established the main role of ELF4 to be regulation of cell-cycle progression, specifically through the DREAM complex. Interestingly, several cell-cycle genes activated by ELF4 are repressed by miR-124, suggesting that they might form a TF–miRNA regulatory loop. Finally, we showed that high ELF4 expression is often observed in neuroblastomas and is associated with poor survival.
Implications:
miR-124 induces neuroblastoma differentiation partially through the downregulation of TF ELF4, which drives neuroblastoma proliferation and its undifferentiated phenotype.
Data from Thymidine Kinase 1 Loss Confers Trifluridine Resistance without Affecting 5-Fluorouracil Metabolism and Cytotoxicity
Authors: Edahiro Keitaro , Iimori Makoto , Kobunai Takashi , Morikawa-Ichinose Tomomi , Miura Daisuke , Kataoka Yuki , Niimi Shinichiro , Wakasa Takeshi , Saeki Hiroshi , Oki Eiji , Kitao Hiroyuki , Maehara Yoshihiko
Published: March 2024

Abstract
Acquired resistance to therapeutic drugs is a serious problem for patients with cancer receiving systemic treatment. Experimentally, drug resistance is established in cell lines in vitro by repeated, continuous exposure to escalating concentrations of the drug; however, the precise mechanism underlying the acquired resistance is not always known. Here, it is demonstrated that the human colorectal cancer cell line DLD1 with acquired resistance to trifluridine (FTD), a key component of the novel, orally administered nucleoside analogue-type chemotherapeutic drug trifluridine/tipiracil, lacks functional thymidine kinase 1 (TK1) expression because of one nonsense mutation in the coding exon. Targeted disruption of the TK1 gene also conferred severe FTD resistance, indicating that the loss of TK1 protein expression is the primary cause of FTD resistance. Both FTD-resistant DLD1 cells and DLD1-TK1−/− cells exhibited similar 5-fluorouracil (5-FU) sensitivity to that of the parental DLD1 line. The quantity of cellular pyrimidine nucleotides in these cells and the kinetics of thymidylate synthase ternary complex formation in 5-FU–treated cells is similar to DLD1 cells, indicating that 5-FU metabolism and cytotoxicity were unaffected. The current data provide molecular-based evidence that acquired resistance to FTD does not confer 5-FU resistance, implying that 5-FU–based chemotherapy would be effective even in tumors that become refractory to FTD during trifluridine/tipiracil treatment. Mol Cancer Res; 16(10); 1483–90. ©2018 AACR.
Data from Interaction Between MUC1 and STAT1 Drives IFITM1 Overexpression in Aromatase Inhibitor–Resistant Breast Cancer Cells and Mediates Estrogen-Induced Apoptosis
Authors: Escher Taylor E. , Lui Asona J. , Geanes Eric S. , Walter Katherine R. , Tawfik Ossama , Hagan Christy R. , Lewis-Wambi Joan
Published: March 2024

Abstract
The human oncoprotein, mucin 1 (MUC1), drives tumorigenesis in breast carcinomas by promoting epithelial-to-mesenchymal transition (EMT), epigenetic reprogramming, and evasion of immune response. MUC1 interacts with STAT1, through JAK/STAT signaling, and stimulates transcription of IFN-stimulated genes, specifically IFN-induced transmembrane protein 1 (IFITM1). Our laboratory has previously shown that IFITM1 overexpression in aromatase inhibitor (AI)-resistant breast cancer cells promotes aggressiveness. Here, we demonstrate that differential regulation of MUC1 in AI-sensitive (MCF-7 and T-47D) compared with AI-resistant (MCF-7:5C) cells is critical in mediating IFITM1 expression. A tumor microarray of 94 estrogen receptor–positive human breast tumors correlated coexpression of MUC1 and IFITM1 with poor recurrence-free survival, poor overall survival, and AI-resistance. In this study, we investigated the effects of MUC1/IFITM1 on cell survival and proliferation. We knocked down MUC1 levels with siRNA and pharmacologic inhibitors, which abrogated IFITM1 mRNA and protein expression and induced cell death in AI-resistant cells. In vivo, estrogen and ruxolitinib significantly reduced tumor size and decreased expression of MUC1, P-STAT1, and IFITM1.
Implications:
MUC1 and IFITM1 overexpression drives AI resistance and can be targeted with currently available therapies.

Visual Overview: http://mcr.aacrjournals.org/content/molcanres/17/5/1180/F1.large.jpg.
Data from Inhibition of the ATR–CHK1 Pathway in Ewing Sarcoma Cells Causes DNA Damage and Apoptosis via the CDK2-Mediated Degradation of RRM2
Authors: Koppenhafer Stacia L. , Goss Kelli L. , Terry William W. , Gordon David J.
Published: March 2024

Abstract
Inhibition of ribonucleotide reductase (RNR), the rate-limiting enzyme in the synthesis of deoxyribonucleotides, causes DNA replication stress and activates the ataxia telangiectasia and rad3-related protein (ATR)-checkpoint kinase 1 (CHK1) pathway. Notably, a number of different cancers, including Ewing sarcoma tumors, are sensitive to the combination of RNR and ATR-CHK1 inhibitors. However, multiple, overlapping mechanisms are reported to underlie the toxicity of ATR-CHK1 inhibitors, both as single agents and in combination with RNR inhibitors, toward cancer cells. Here, we identified a feedback loop in Ewing sarcoma cells in which inhibition of the ATR–CHK1 pathway depletes RRM2, the small subunit of RNR, and exacerbates the DNA replication stress and DNA damage caused by RNR inhibitors. Mechanistically, we identified that the inhibition of ATR-CHK1 activates CDK2, which targets RRM2 for degradation via the proteasome. Similarly, activation of CDK2 by inhibition or knockdown of the WEE1 kinase also depletes RRM2 and causes DNA damage and apoptosis. Moreover, we show that the concurrent inhibition of ATR and WEE1 has a synergistic effect in Ewing sarcoma cells. Overall, our results provide novel insight into the response to DNA replication stress, as well as a rationale for targeting the ATR, CHK1, and WEE1 pathways, in Ewing sarcoma tumors.
Implications:
Targeting the ATR, CHK1, and WEE1 kinases in Ewing sarcoma cells activates CDK2 and increases DNA replication stress by promoting the proteasome-mediated degradation of RRM2.
Data from A TAZ–ANGPTL4–NOX2 Axis Regulates Ferroptotic Cell Death and Chemoresistance in Epithelial Ovarian Cancer
Authors: Yang Wen-Hsuan , Huang Zhiqing , Wu Jianli , Ding Chien-Kuang C. , Murphy Susan K. , Chi Jen-Tsan
Published: March 2024

Abstract
Ovarian cancer is the deadliest gynecologic cancer. Despite recent advances, clinical outcomes remain poor, necessitating novel therapeutic approaches. To investigate metabolic susceptibility, we performed nutrigenetic screens on a panel of clear cell and serous ovarian cancer cells and identified cystine addiction and vulnerability to ferroptosis, a novel form of regulated cell death. Our results may have therapeutic potential, but little is known about the determinants of ferroptosis susceptibility in ovarian cancer. We found that vulnerability to ferroptosis in ovarian cancer cells is enhanced by lower cell confluency. Because the Hippo pathway effectors Yes-associated protein (YAP)/transcriptional coactivator with PDZ-binding motif (TAZ) are recognized as sensors of cell density, and TAZ is the predominant effector in the tested ovarian cancer cell lines, we investigated the role of TAZ in ferroptosis of ovarian cancer. TAZ removal confers ferroptosis resistance, while TAZS89A overexpression sensitizes cells to ferroptosis. In addition, we found that lower TAZ level in chemo-resistant recurrent ovarian cancer is responsible for reduced ferroptosis susceptibility. The integrative genomic analysis identified ANGPTL4 as a direct TAZ-regulated target gene that sensitizes ferroptosis by activating NOX2. Collectively, cell density–regulated ferroptosis in ovarian cancer is mediated by TAZ through the regulation of the ANGPTL4–NOX2 axis, suggesting therapeutic potentials for ovarian cancers and other TAZ-activated tumors.
Implications:
This study reveals that TAZ promotes ferroptosis in ovarian cancers by regulating ANGPTL4 and NOX, offering a novel therapeutic potential for ovarian tumors with TAZ activation.