bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from TAS6417/CLN-081 Is a Pan-Mutation–Selective EGFR Tyrosine Kinase Inhibitor with a Broad Spectrum of Preclinical Activity against Clinically Relevant EGFR Mutations
Authors: Udagawa Hibiki , Hasako Shinichi , Ohashi Akihiro , Fujioka Rumi , Hakozaki Yumi , Shibuya Mikiko , Abe Naomi , Komori Toshiharu , Haruma Tomonori , Terasaka Miki , Fujita Ryoto , Hashimoto Akihiro , Funabashi Kaoru , Yasuda Hiroyuki , Miyadera Kazutaka , Goto Koichi , Costa Daniel B. , Kobayashi Susumu S.
Published: April 2023

Abstract
Despite the worldwide approval of three generations of EGFR tyrosine kinase inhibitors (TKI) for advanced non–small cell lung cancers with EGFR mutations, no TKI with a broad spectrum of activity against all clinically relevant mutations is currently available. In this study, we sought to evaluate a covalent mutation-specific EGFR TKI, TAS6417 (also named CLN-081), with the broadest level of activity against EGFR mutations with a prevalence of ≥1%. Lung cancer and genetically engineered cell lines, as well as murine xenograft models were used to evaluate the efficacy of TAS6417 and other approved/in-development EGFR TKIs (erlotinib, afatinib, osimertinib, and poziotinib). We demonstrate that TAS6417 is a robust inhibitor against the most common EGFR mutations (exon 19 deletions and L858R) and the most potent against cells harboring EGFR-T790M (first/second-generation TKI resistance mutation). In addition, TAS6417 has activity in cells driven by less common EGFR-G719X, L861Q, and S768I mutations. For recalcitrant EGFR exon 20 insertion mutations, selectivity indexes (wild-type EGFR/mutant EGFR ratio of inhibition) favored TAS6417 in comparison with poziotinib and osimertinib, indicating a wider therapeutic window. Taken together, we demonstrate that TAS6417 is a potent EGFR TKI with a broad spectrum of activity and a wider therapeutic window than most approved/in-development generations of EGFR inhibitors.
Implications:
TAS6417/CLN-081 is a potent EGFR TKI with a wide therapeutic window and may be effective in lung cancer patients with clinically relevant EGFR mutations.
Data from The Hypoxic Tumor Microenvironment Promotes Invadopodia Formation and Metastasis through LPA1 Receptor and EGFR Cooperation
Authors: Harper Kelly , R. Lavoie Roxane , Charbonneau Martine , Brochu-Gaudreau Karine , Dubois Claire M.
Published: April 2023

Abstract
Hypoxia, a common feature of solid tumors, has been critically involved in cell invasion and metastasis, but the underlying mechanisms remain poorly understood. Previously, it has been observed that the lysophosphatidic acid receptor 4 (LPA4) signaling axis mediates production of the degradative subcellular structures invadopodia, which are known to be required for metastasis. Here, it is demonstrated that LPA1 (LPAR1) is a common and major receptor used for hypoxia-induced invadopodia production in various cancer cell lines. The widespread use of LPA1 was not due to increased LPA1 expression but rather relied on Src-mediated cross-talk with EGFR. LPA1-mediated phosphorylation of Y845-EGFR under hypoxia led to PI3K/Akt activation, an event that increases the ability of cells to produce invadopodia. Moreover, phospho-Y845-EGFR was upregulated in hypoxic zones of tumors and a combination of EGFR and LPA1 inhibition synergistically suppressed metastasis in vivo.

Implications: This study uncovers an LPA1–EGFR signaling axis that is used for cell invasion in hypoxia and suggests a potential target to impede cancer metastasis. Mol Cancer Res; 16(10); 1601–13. ©2018 AACR.
Data from Targeting USP22 Suppresses Tumorigenicity and Enhances Cisplatin Sensitivity Through ALDH1A3 Downregulation in Cancer-Initiating Cells from Lung Adenocarcinoma
Authors: Yun Xinwei , Zhang Keqiang , Wang Jinhui , Pangeni Rajendra P. , Yang Lu , Bonner Melissa , Wu Jun , Wang Jami , Nardi Isaac K. , Gao Ming , Raz Dan J.
Published: April 2023

Abstract
Loss of monoubiquitination of histone H2B (H2Bub1) was found to be associated with poor-differentiation and enhanced malignancy of lung adenocarcinoma. This study investigated the association and impact of the ubiquitin-specific peptidase 22 (USP22), an H2Bub1 deubiquitinase, on stem cell-like characteristics and cisplatin resistance in cancer-initiating cells (CIC) from primary lung adenocarcinoma. CICs were isolated, enriched, and characterized from patient-derived cancer tissues using both in vitro tumorsphere formation and in vivo xenograft assays. USP22 was determined to be predominantly expressed in CICs, a subpopulation of cells with high expression of the stem cell biomarkers, CD133 and CD44. The expression of USP22 in CICs is markedly reduced upon FBS/retinoic acid-induced differentiation. Moreover, knockdown of USP22 significantly suppressed tumorsphere formation and xenograft growth in NOD-SCID gamma (NSG) mice. Notably, USP22 and aldehyde dehydrogenase (ALDH) activity were elevated in tumorsphere cells that survived cisplatin treatment, whereas knockdown of USP22 significantly sensitizes tumorsphere cells to cisplatin. Interestingly, ALDH1A3, a predominant ALDH isozyme implicated in enhancing cisplatin resistance in lung adenocarcinoma, is significantly downregulated upon knockdown of USP22 in tumorsphere cells. Furthermore, knockdown of ALDH1A3 significantly sensitizes tumorsphere cells to cisplatin. Combined, these data demonstrate that USP22, predominantly expressed in CD133+ CICs, plays a critical role in tumorigenicity and cisplatin resistance in lung adenocarcinoma.

Implications: Targeting USP22 represents a potential therapeutic approach to suppress CICs in lung adenocarcinoma partially through downregulation of ALDH1A3 expression. Mol Cancer Res; 16(7); 1161–71. ©2018 AACR.
Data from Elevated V–ATPase Activity Following PTEN Loss Is Required for Enhanced Oncogenic Signaling in Breast Cancer
Authors: Mohammad Amro H. , Kim Sung-Hoon , Bertos Nicholas , El-Assaad Wissal , Nandi Ipshita , Smith Harvey , Yang Jieyi , Chen Owen J. , Gamache Isabelle , Rao Trisha , Gagnon Bruno , Gruosso Tina , Tremblay Michel L. , Sonenberg Nahum , Guiot Marie-Christine , Muller William , Park Morag , Teodoro Jose G.
Published: April 2023

Abstract
PTEN loss-of-function contributes to hyperactivation of the PI3K pathway and to drug resistance in breast cancer. Unchecked PI3K pathway signaling increases activation of the mechanistic target of rapamycin complex 1 (mTORC1), which promotes tumorigenicity. Several studies have suggested that vacuolar (H+)–ATPase (V–ATPase) complex activity is regulated by PI3K signaling. In this study, we showed that loss of PTEN elevated V–ATPase activity. Enhanced V–ATPase activity was mediated by increased expression of the ATPase H+ transporting accessory protein 2 (ATP6AP2), also known as the prorenin receptor (PRR). PRR is cleaved into a secreted extracellular fragment (sPRR) and an intracellular fragment (M8.9) that remains associated with the V–ATPase complex. Reduced PTEN expression increased V–ATPase complex activity in a PRR-dependent manner. Breast cancer cell lines with reduced PTEN expression demonstrated increased PRR expression. Similarly, PRR expression became elevated upon PTEN deletion in a mouse model of breast cancer. Interestingly, concentration of sPRR was elevated in the plasma of patients with breast cancer and correlated with tumor burden in HER2-enriched cancers. Moreover, PRR was essential for proper HER2 receptor expression, localization, and signaling. PRR knockdown attenuated HER2 signaling and resulted in reduced Akt and ERK 1/2 phosphorylation, and in lower mTORC1 activity. Overall, our study demonstrates a mechanism by which PTEN loss in breast cancer can potentiate multiple signaling pathways through upregulation of the V–ATPase complex.
Implications:
Our study contributed to the understanding of the role of the V–ATPase complex in breast cancer cell tumorigenesis and provided a potential biomarker in breast cancer.
Data from The mTOR Targets 4E-BP1/2 Restrain Tumor Growth and Promote Hypoxia Tolerance in PTEN-driven Prostate Cancer
Authors: Ding Mei , Van der Kwast Theodorus H. , Vellanki Ravi N. , Foltz Warren D. , McKee Trevor D. , Sonenberg Nahum , Pandolfi Pier P. , Koritzinsky Marianne , Wouters Bradly G.
Published: April 2023

Abstract
The mTOR signaling pathway is a central regulator of protein synthesis and cellular metabolism in response to the availability of energy, nutrients, oxygen, and growth factors. mTOR activation leads to phosphorylation of multiple downstream targets including the eukaryotic initiation factor 4E (eIF4E) binding proteins-1 and -2 (EIF4EBP1/4E-BP1 and EIF4EBP2/4E-BP2). These binding proteins inhibit protein synthesis, but are inactivated by mTOR to stimulate cell growth and metabolism. However, the role of these proteins in the context of aberrant activation of mTOR, which occurs frequently in cancers through loss of PTEN or mutational activation of the PI3K/AKT pathway, is unclear. Here, even under conditions of aberrant mTOR activation, hypoxia causes dephosphorylation of 4E-BP1/4E-BP2 and increases their association with eIF4E to suppress translation. This is essential for hypoxia tolerance as knockdown of 4E-BP1 and 4E-BP2 decreases proliferation under hypoxia and increases hypoxia-induced cell death. In addition, genetic deletion of 4E-BP1 and 4E-BP2 significantly accelerates all phases of cancer development in the context of PTEN loss–driven prostate cancer in mice despite potent PI3K/AKT and mTOR activation. However, even with a more rapid onset, tumors that establish in the absence of 4E-BP1 and 4E-BP2 have reduced levels of tumor hypoxia and show increased cell death within hypoxic tumor regions. Together, these data demonstrate that 4E-BP1 and 4E-BP2 act as essential metabolic breaks even in the context of aberrant mTOR activation and that they are essential for the creation of hypoxia-tolerant cells in prostate cancer. Mol Cancer Res; 16(4); 682–95. ©2018 AACR.
Data from Metformin Reduces Prostate Tumor Growth, in a Diet-Dependent Manner, by Modulating Multiple Signaling Pathways
Authors: Sarmento-Cabral André , L-López Fernando , Gahete Manuel D. , Castaño Justo P. , Luque Raúl M.
Published: April 2023

Abstract
Prostate-cancer is strongly influenced by obesity, wherein metformin could represent a promising treatment; however, the endocrine metabolic/cellular/molecular mechanisms underlying these associations and effects are still unclear. To determine the beneficial antitumoral effects of metformin on prostate cancer progression/aggressiveness and the relative contribution of high-fat diet (HFD; independently of obesity), we used HFD-fed immunosuppressed mice inoculated with PC3 cells (which exhibited partial resistance to diet-induced obesity) compared with low-fat diet (LFD)-fed control mice. Moreover, gene expression analysis was performed on cancer-associated genes in the xenografted tumors, and the antitumorigenic role of metformin on tumoral (PC3/22Rv1/LNCaP) and normal (RWPE1) prostate cells was evaluated. The results demonstrate that HFD is associated with enhanced prostate cancer growth irrespective of body weight gain and endocrine metabolic dysregulations and that metformin can reduce prostate cancer growth under LFD but more prominently under HFD, acting through the modulation of several tumoral-associated processes (e.g., cell cycle, apoptosis, and/or necrosis). Moreover, the actions observed in vivo could be mediated by the modulation of the local expression of GH/IGF1 axis components. Finally, it was demonstrated that metformin had disparate effects on proliferation, migration, and prostate-specific antigen secretion from different cell lines. Altogether, these data reveal that metformin inhibits prostate cancer growth under LFD and, specially, under HFD conditions through multiple metabolic/tumoral signaling pathways.

Implications: The current study linking dietary influence on metformin-regulated signaling pathways and antitumoral response provides new and critical insight on environment–host interactions in cancer and therapy. Mol Cancer Res; 15(7); 862–74. ©2017 AACR.
Data from Inhibition of Ciliogenesis Promotes Hedgehog Signaling, Tumorigenesis, and Metastasis in Breast Cancer
Authors: Hassounah Nadia B. , Nunez Martha , Fordyce Colleen , Roe Denise , Nagle Ray , Bunch Thomas , McDermott Kimberly M.
Published: April 2023

Abstract
Primary cilia are chemosensors that play a dual role to either activate or repress Hedgehog signaling, depending on presence or absence of ligand, respectively. While inhibition of ciliogenesis has been shown to be characteristic of breast cancers, the functional consequence is unknown. Here, for the first time, inhibition of ciliogenesis led to earlier tumor formation, faster tumor growth rate, higher grade tumor formation, and increased metastasis in the polyoma middle T (PyMT) mouse model of breast cancer. In in vitro model systems, inhibition of ciliogenesis resulted in increased expression of Hedgehog-target genes through a mechanism involving loss of the repressor form of the GLI transcription factor (GLIR) and activation of Hedgehog target gene expression through cross-talk with TGF-alpha (TGFA) signaling. Bioinformatics analysis revealed that increased Hedgehog signaling is frequently associated with increased TGFA; signaling in patients with triple-negative breast cancers (TNBC), a particularly aggressive breast cancer subtype. These results identify a previously unrecognized role for inhibition of ciliogenesis in breast cancer progression. This study identifies inhibition of ciliogenesis as an important event for activation of Hedgehog signaling and progression of breast cancer to a more aggressive, metastatic disease.

Implications: These findings change the way we understand how cancer cells turn on a critical signaling pathways and a provide rationale for developing novel therapeutic approaches to target noncanonical Hedgehog signaling for the treatment of breast cancer. Mol Cancer Res; 15(10); 1421–30. ©2017 AACR.
Data from Mutational Landscape of Ovarian Adult Granulosa Cell Tumors from Whole Exome and Targeted TERT Promoter Sequencing
Authors: Alexiadis Maria , Rowley Simone M. , Chu Simon , Leung Dilys T.H. , Stewart Colin J.R. , Amarasinghe Kaushalya C. , Campbell Ian G. , Fuller Peter J.
Published: April 2023

Abstract
Adult granulosa cell tumor (aGCT), the most common malignant ovarian sex cord-stromal tumor, is characterized by the forkhead transcription factor FOXL2 p.C134W somatic mutation. Late recurrences are relatively common but the molecular mechanisms of relapse or aggressive behavior are not known. The mutational landscape of FOXL2 p.C134W mutation–positive tumors (n = 22) was determined using whole-exome sequencing (WES). An average of 64 coding and essential splice-site variants were identified per tumor. As the TERT promoter region is poorly covered by the WES, targeted sequencing identified the TERT -124C>T promoter mutation as the only recurrent mutation (∼40% of cases). Pathway analysis suggested an association with DNA replication/repair and the EGFR family canonical pathways. Copy number analysis confirmed that gains of chromosomes 12 and 14 occur in approximately 30% of aGCT and loss of chromosome 22 occurs in approximately 40% of cases. In summary, exome-wide analysis of the mutational landscape of aGCT revealed that, except for the TERT promoter mutation, recurrence and/or aggressive behavior is not defined by activation or loss of specific genes.
Implications:
This study found that although aGCTs are defined by the presence of a common FOXL2 gene mutation, recurrence and/or aggressive behavior cannot be attributed to subsequent mutation of specific gene(s) or pathways; however, there is a high frequency of the TERT -124C>T promoter mutation, which is associated with more aggressive disease.
Data from Interferon-Stimulated Genes Are Transcriptionally Repressed by PR in Breast Cancer
Authors: Walter Katherine R. , Goodman Merit L. , Singhal Hari , Hall Jade A. , Li Tianbao , Holloran Sean M. , Trinca Gloria M. , Gibson Katelin A. , Jin Victor X. , Greene Geoffrey L. , Hagan Christy R.
Published: April 2023

Abstract
The progesterone receptor (PR) regulates transcriptional programs that drive proliferation, survival, and stem cell phenotypes. Although the role of native progesterone in the development of breast cancer remains controversial, PR clearly alters the transcriptome in breast tumors. This study identifies a class of genes, Interferon (IFN)-stimulated genes (ISGs), potently downregulated by ligand-activated PR which have not been previously shown to be regulated by PR. Progestin-dependent transcriptional repression of ISGs was observed in breast cancer cell line models and human breast tumors. Ligand-independent regulation of ISGs was also observed, as basal transcript levels were markedly higher in cells with PR knockdown. PR repressed ISG transcription in response to IFN treatment, the canonical mechanism through which these genes are activated. Liganded PR is robustly recruited to enhancer regions of ISGs, and ISG transcriptional repression is dependent upon PR's ability to bind DNA. In response to PR activation, key regulatory transcription factors that are required for IFN-activated ISG transcription, STAT2 and IRF9, exhibit impaired recruitment to ISG promoter regions, correlating with PR/ligand-dependent ISG transcriptional repression. IFN activation is a critical early step in nascent tumor recognition and destruction through immunosurveillance. As the large majority of breast tumors are PR positive at the time of diagnosis, PR-dependent downregulation of IFN signaling may be a mechanism through which early PR-positive breast tumors evade the immune system and develop into clinically relevant tumors.

Implications: This study highlights a novel transcriptional mechanism through which PR drives breast cancer development and potentially evades the immune system. Mol Cancer Res; 15(10); 1331–40. ©2017 AACR.
Data from Near-Infrared Photoimmunotherapy Targeting Prostate Cancer with Prostate-Specific Membrane Antigen (PSMA) Antibody
Authors: Nagaya Tadanobu , Nakamura Yuko , Okuyama Shuhei , Ogata Fusa , Maruoka Yasuhiro , Choyke Peter L. , Kobayashi Hisataka
Published: April 2023

Abstract
Prostate-specific membrane antigen (PSMA) is a membrane protein that is overexpressed manifold in prostate cancer and provides an attractive target for molecular therapy. Near-infrared photoimmunotherapy (NIR-PIT) is a highly selective tumor treatment that employs an antibody-photoabsorber conjugate (APC). Here, we describe the efficacy of NIR-PIT, using a fully human IgG1 anti-PSMA monoclonal antibody (mAb), conjugated to the photoabsorber, IR700DX, in a PSMA-expressing PC3 prostate cancer cell line. Anti-PSMA-IR700 showed specific binding and cell-specific killing was observed after exposure of the cells to NIR light in vitro. In the in vivo study, anti-PSMA-IR700 showed high tumor accumulation and high tumor–background ratio. Tumor-bearing mice were separated into 4 groups: (i) no treatment; (ii) 100 μg of anti-PSMA-IR700 i.v.; (iii) NIR light exposure; (iv) 100 μg of anti-PSMA-IR700 i.v., NIR light exposure was administered. These were performed every week for up to 3 weeks. Tumor growth was significantly inhibited by NIR-PIT treatment compared with the other control groups (P < 0.001), and significantly prolonged survival was achieved (P < 0.0001 vs. other control groups). More than two thirds of tumors were cured with NIR-PIT. In conclusion, the anti-PSMA antibody is suitable as an APC for NIR-PIT. Furthermore, NIR-PIT with the anti-PSMA-IR700 antibody is a promising candidate of the treatment of PSMA-expressing tumors and could be readily translated to humans.

Implications: NIR-infrared photoimmunotherapy (NIR-PIT) using a fully human anti-PSMA-IR700 conjugate showed potential therapeutic effects against a PSMA-expressing prostate cancer that is readily translated to humans. Mol Cancer Res; 15(9); 1153–62. ©2017 AACR.
Data from Discovery and Characterization of Recurrent, Targetable ALK Fusions in Leiomyosarcoma
Authors: Davis Lara E. , Nusser Kevin D. , Przybyl Joanna , Pittsenbarger Janét , Hofmann Nicolle E. , Varma Sushama , Vennam Sujay , Debiec-Rychter Maria , van de Rijn Matt , Davare Monika A.
Published: April 2023

Abstract
Soft-tissue sarcomas such as leiomyosarcoma pose a clinical challenge because systemic treatment options show only modest therapeutic benefit. Discovery and validation of targetable vulnerabilities is essential. To discover putative kinase fusions, we analyzed existing transcriptomic data from leiomyosarcoma clinical samples. Potentially oncogenic ALK rearrangements were confirmed by application of multiple RNA-sequencing fusion detection algorithms and FISH. We functionally validated the oncogenic potential and targetability of discovered kinase fusions through biochemical, cell-based (Ba/F3, NIH3T3, and murine smooth muscle cell) and in vivo tumor modeling approaches. We identified ALK rearrangements in 9 of 377 (2.4%) patients with leiomyosarcoma, including a novel KANK2-ALK fusion and a recurrent ACTG2-ALK fusion. Functional characterization of the novel ALK fusion, KANK2-ALK, demonstrates it is a dominant oncogene in Ba/F3 or NIH3T3 model systems, and has tumorigenic potential when introduced into smooth muscle cells. Oral monotherapy with targeted ALK kinase inhibitor lorlatinib significantly inhibits tumor growth and prolongs survival in a murine model of KANK2-ALK leiomyosarcoma. These results provide the first functional validation of a targetable oncogenic kinase fusion as a driver in a subset of leiomyosarcomas. Overall, these findings suggest that some soft-tissue sarcomas may harbor previously unknown kinase gene translocations, and their discovery may propel new therapeutic strategies in this treatment-refractory cancer.
Implications:
A subset of leiomyosarcomas harbor previously unrecognized oncogenic ALK fusions that are highly responsive to ALK inhibitors and thus these data emphasize the importance of detailed genomic investigations of leiomyosarcoma tumors.
Data from A Minimal DNA Methylation Signature in Oral Tongue Squamous Cell Carcinoma Links Altered Methylation with Tumor Attributes
Authors: Krishnan Neeraja M. , Dhas Kunal , Nair Jayalakshmi , Palve Vinayak , Bagwan Jamir , Siddappa Gangotri , Suresh Amritha , Kekatpure Vikram D. , Kuriakose Moni Abraham , Panda Binay
Published: April 2023

Abstract
Oral tongue squamous cell carcinomas (OTSCC) are a homogenous group of aggressive tumors in the head and neck region that spread early to lymph nodes and have a higher incidence of regional failure. In addition, there is a rising incidence of oral tongue cancer in younger populations. Studies on functional DNA methylation changes linked with altered gene expression are critical for understanding the mechanisms underlying tumor development and metastasis. Such studies also provide important insight into biomarkers linked with viral infection, tumor metastasis, and patient survival in OTSCC. Therefore, we performed genome-wide methylation analysis of tumors (N = 52) and correlated altered methylation with differential gene expression. The minimal tumor-specific DNA 5-methylcytosine signature identified genes near 16 different differentially methylated regions, which were validated using genomic data from The Cancer Genome Atlas cohort. In our cohort, hypermethylation of MIR10B was significantly associated with the differential expression of its target genes NR4A3 and BCL2L11 (P = 0.0125 and P = 0.014, respectively), which was inversely correlated with disease-free survival (P = 9E−15 and P = 2E−15, respectively) in patients. Finally, differential methylation in FUT3, TRIM5, TSPAN7, MAP3K8, RPS6KA2, SLC9A9, and NPAS3 genes was found to be predictive of certain clinical and epidemiologic parameters.

Implications: This study reveals a functional minimal methylation profile in oral tongue tumors with associated risk habits, clinical, and epidemiologic outcomes. In addition, NR4A3 downregulation and correlation with patient survival suggests a potential target for therapeutic intervention in oral tongue tumors. Data from the current study are deposited in the NCBI Geo database (accession number GSE75540). Mol Cancer Res; 14(9); 805–19. ©2016 AACR.
Data from HDAC1 Is a Required Cofactor of CBFβ-SMMHC and a Potential Therapeutic Target in Inversion 16 Acute Myeloid Leukemia
Authors: Richter Lisa E. , Wang Yiqian , Becker Michelle E. , Coburn Rachel A. , Williams Jacob T. , Amador Catalina , Hyde R. Katherine
Published: April 2023

Abstract
Acute myeloid leukemia (AML) is a neoplastic disease characterized by the uncontrolled proliferation and accumulation of immature myeloid cells. A common mutation in AML is the inversion of chromosome 16 [inv (16)], which generates a fusion between the genes for core binding factor beta (CBFB) and smooth muscle myosin heavy chain gene (MYH11), forming the oncogene CBFB-MYH11. The expressed protein, CBFβ-SMMHC, forms a heterodimer with the key hematopoietic transcription factor RUNX1. Although CBFβ-SMMHC was previously thought to dominantly repress RUNX1, recent work suggests that CBFβ-SMMHC functions together with RUNX1 to activate transcription of specific target genes. However, the mechanism of this activity or a requirement for additional cofactors is not known. Here, we show that the epigenetic regulator histone deacetylase 1 (HDAC1) forms a complex with CBFβ-SMMHC, colocalizes with RUNX1 and CBFβ-SMMHC on the promoters of known fusion protein target genes, and that Hdac1 is required for expression of these genes. These results imply that HDAC1 is an important component of the CBFβ-SMMHC transcriptional complex, and that leukemia cells expressing the fusion protein may be sensitive to treatment with HDAC1 inhibitors. Using a knock-in mouse model expressing CBFβ-SMMHC, we found that in vivo treatment with the HDAC1 inhibitor entinostat decreased leukemic burden, and induced differentiation and apoptosis of leukemia cells. Together, these results demonstrate that HDAC1 is an important cofactor of CBFβ-SMMHC and a potential therapeutic target in inv (16) AML.
Implications:
This report describes a novel role for HDAC1 as a cofactor for the leukemogenic fusion protein CBFβ-SMMHC and shows that inhibitors of HDAC1 effectively target leukemia cells expressing the fusion protein in vivo.
Data from ADAM12 Is a Novel Regulator of Tumor Angiogenesis via STAT3 Signaling
Authors: Roy Roopali , Dagher Adelle , Butterfield Catherine , Moses Marsha A.
Published: April 2023

Abstract
ADAM12, (A Disintegrin and metalloproteinase domain-containing protein 12), is upregulated in epithelial cancers and contributes to increased tumor proliferation, metastasis, and endocrine resistance. However, its role in tumor angiogenesis is unknown. Here, we report that ADAM12 is upregulated in the vessels of aggressive breast tumors and exerts key regulatory functions. ADAM12 significantly increases bFGF-mediated angiogenesis in vivo and ADAM12 levels are upregulated in tumors that have undergone a switch to the angiogenic phenotype. Importantly, ADAM12-overexpressing breast tumors display a higher microvessel density (MVD). Our goal was to identify the mechanisms by which tumor-associated ADAM12 promotes angiogenesis. ADAM12 expression in breast tumor cells correlated with a significant upregulation of proangiogenic factors such as VEGF and MMP-9 and downregulation of antiangiogenic factors such as Thrombospondin-1 (THBS1/TSP1) and Tissue Inhibitor of Metalloproteinases-2 (TIMP-2). Co-culture with ADAM12-expressing tumor cells promoted endothelial cell (EC) recruitment and capillary tube formation. Conversely, downregulation of endogenous ADAM12 in breast cancer cell lines resulted in reduction of pro-angiogenic factors and EC recruitment. These ADAM12-mediated effects are driven by the activation of EGFR, STAT3 and Akt signaling. Blockade of EGFR/STAT3 or silencing of ADAM12 reversed the proangiogenic tumor phenotype, significantly downregulated pro-angiogenic mitogens and reduced EC recruitment. In human breast cancer tissues, ADAM12 expression was significantly positively correlated with pro-angiogenic factors including VEGF and MMP-9 but negatively associated with TSP1.

Implications: These novel findings suggest that ADAM12 regulates EC function and facilitates a proangiogenic microenvironment in a STAT3-dependent manner. A combined approach of targeting ADAM12 and STAT3 signaling in breast cancer may represent a promising strategy to inhibit tumor neovascularization. Mol Cancer Res; 15(11); 1608–22. ©2017 AACR.
Data from Synthetic Lethality of PARP Inhibition and Ionizing Radiation is p53-dependent
Authors: Sizemore Steven T. , Mohammad Rahman , Sizemore Gina M. , Nowsheen Somaira , Yu Hao , Ostrowski Michael C. , Chakravarti Arnab , Xia Fen
Published: April 2023

Abstract
PARP inhibitors (PARPi) are potentially effective therapeutic agents capable of inducing synthetic lethality in tumors with deficiencies in homologous recombination (HR)-mediated DNA repair such as those carrying BRCA1 mutations. However, BRCA mutations are rare, the majority of tumors are proficient in HR repair, and thus most tumors are resistant to PARPi. Previously, we observed that ionizing radiation (IR) initiates cytoplasmic translocation of BRCA1 leading to suppression of HR-mediated DNA repair and induction of synthetic PARPi lethality in wild-type BRCA1 and HR-proficient tumor cells. The tumor suppressor p53 was identified as a key factor that regulates DNA damage–induced BRCA1 cytoplasmic sequestration following IR. However, the role of p53 in IR-induced PARPi sensitization remains unclear. This study elucidates the role of p53 in IR-induced PARPi cytotoxicity in HR-proficient cancer cells and suggests p53 status may help define a patient population that might benefit from this treatment strategy. Sensitization to PARPi following IR was determined in vitro and in vivo utilizing human breast and glioma tumor cells carrying wild-type BRCA1 and p53, and in associated cells in which p53 function was modified by knockdown or mutation. In breast and glioma cells with proficient HR repair, IR-induced BRCA1 cytoplasmic sequestration, HR repair inhibition, and subsequent PARPi sensitization in vitro and in vivo was dependent upon functional p53.

Implications: Implications: p53 status determines PARP inhibitor sensitization by ionizing radiation in multiple BRCA1 and HR-proficient tumor types and may predict which patients are most likely to benefit from combination therapy. Mol Cancer Res; 16(7); 1092–102. ©2018 AACR.
Data from Combining Homologous Recombination and Phosphopeptide-binding Data to Predict the Impact of BRCA1 BRCT Variants on Cancer Risk
Authors: Petitalot Ambre , Dardillac Elodie , Jacquet Eric , Nhiri Naima , Guirouilh-Barbat Josée , Julien Patrick , Bouazzaoui Isslam , Bonte Dorine , Feunteun Jean , Schnell Jeff A. , Lafitte Philippe , Aude Jean-Christophe , Noguès Catherine , Rouleau Etienne , Lidereau Rosette , Lopez Bernard S. , Zinn-Justin Sophie , Caputo Sandrine M.
Published: April 2023

Abstract
BRCA1 mutations have been identified that increase the risk of developing hereditary breast and ovarian cancers. Genetic screening is now offered to patients with a family history of cancer, to adapt their treatment and the management of their relatives. However, a large number of BRCA1 variants of uncertain significance (VUS) are detected. To better understand the significance of these variants, a high-throughput structural and functional analysis was performed on a large set of BRCA1 VUS. Information on both cellular localization and homology-directed DNA repair (HR) capacity was obtained for 78 BRCT missense variants in the UMD-BRCA1 database and measurement of the structural stability and phosphopeptide-binding capacities was performed for 42 mutated BRCT domains. This extensive and systematic analysis revealed that most characterized causal variants affect BRCT-domain solubility in bacteria and all impair BRCA1 HR activity in cells. Furthermore, binding to a set of 5 different phosphopeptides was tested: all causal variants showed phosphopeptide-binding defects and no neutral variant showed such defects. A classification is presented on the basis of mutated BRCT domain solubility, phosphopeptide-binding properties, and VUS HR capacity. These data suggest that HR-defective variants, which present, in addition, BRCT domains either insoluble in bacteria or defective for phosphopeptide binding, lead to an increased cancer risk. Furthermore, the data suggest that variants with a WT HR activity and whose BRCT domains bind with a WT affinity to the 5 phosphopeptides are neutral. The case of variants with WT HR activity and defective phosphopeptide binding should be further characterized, as this last functional defect might be sufficient per se to lead to tumorigenesis.
Implications:
The analysis of the current study on BRCA1 structural and functional defects on cancer risk and classification presented may improve clinical interpretation and therapeutic selection.
Data from A Role for Tryptophan-2,3-dioxygenase in CD8 T-cell Suppression and Evidence of Tryptophan Catabolism in Breast Cancer Patient Plasma
Authors: Greene Lisa I. , Bruno Tullia C. , Christenson Jessica L. , D'Alessandro Angelo , Culp-Hill Rachel , Torkko Kathleen , Borges Virginia F. , Slansky Jill E. , Richer Jennifer K.
Published: April 2023

Abstract
Tryptophan catabolism is an attractive target for reducing tumor progression and improving antitumor immunity in multiple cancers. Tumor infiltration by CD8 T cells correlates with improved prognosis in triple-negative breast cancer (TNBC) and a significant effort is underway to improve CD8 T-cell antitumor activity. In this study, primary human immune cells were isolated from the peripheral blood of patients and used to demonstrate that the tryptophan catabolite kynurenine induces CD8 T-cell death. Furthermore, it is demonstrated that anchorage-independent TNBC utilizes the tryptophan-catabolizing enzyme tryptophan 2,3-dioxygenase (TDO) to inhibit CD8 T-cell viability. Publicly available data revealed that high TDO2, the gene encoding TDO, correlates with poor breast cancer clinical outcomes, including overall survival and distant metastasis-free survival, while expression of the gene encoding the more commonly studied tryptophan-catabolizing enzyme, IDO1 did not. Metabolomic analysis, using quantitative mass spectrometry, of tryptophan and its catabolites, including kynurenine, in the plasma from presurgical breast cancer patients (n = 77) and 40 cancer-free donors (n = 40) indicated a strong correlation between substrate and catabolite in both groups. Interestingly, both tryptophan and kynurenine were lower in the plasma from patients with breast cancer compared with controls, particularly in women with estrogen receptor (ER)-negative and stage III and IV breast cancer.
Implications:
This study underscores the importance of tryptophan catabolism, particularly in aggressive disease, and suggests that future pharmacologic efforts should focus on developing drugs that target both TDO and IDO1.
Data from Normal and Cancerous Tissues Release Extrachromosomal Circular DNA (eccDNA) into the Circulation
Authors: Kumar Pankaj , Dillon Laura W. , Shibata Yoshiyuki , Jazaeri Amir A. , Jones David R. , Dutta Anindya
Published: April 2023

Abstract
Cell-free circulating linear DNA is being explored for noninvasive diagnosis and management of tumors and fetuses, the so-called liquid biopsy. Previously, we observed the presence of small extrachromosomal circular DNA (eccDNA), called microDNA, in the nuclei of mammalian tissues and cell lines. Now, we demonstrate that cell-free microDNA derived from uniquely mapping regions of the genome is detectable in plasma and serum from both mice and humans and that they are significantly longer (30%–60% >250 bases) than cell-free circulating linear DNA (∼150 bases). Tumor-derived human microDNA is detected in the mouse circulation in a mouse xenograft model of human ovarian cancer. Comparing the microDNA from paired tumor and normal lung tissue specimens reveals that the tumors contain longer microDNA. Consistent with human cancers releasing microDNA into the circulation, serum and plasma samples (12 lung and 11 ovarian cancer) collected prior to surgery are enriched for longer cell-free microDNA compared with samples from the same patient obtained several weeks after surgical resection of the tumor. Thus, circular DNA in the circulation is a previously unexplored pool of nucleic acids that could complement miRNAs and linear DNA for diagnosis and for intercellular communication.

Implications: eccDNA derived from chromosomal genomic sequence, first discovered in the nuclei of cells, are detected in the circulation, are longer than linear cell-free DNA, and are released from normal tissue and tumors into the circulation. Mol Cancer Res; 15(9); 1197–205. ©2017 AACR.
Data from HIF1α Regulates mTOR Signaling and Viability of Prostate Cancer Stem Cells
Authors: Marhold Maximilian , Tomasich Erwin , El-Gazzar Ahmed , Heller Gerwin , Spittler Andreas , Horvat Reinhard , Krainer Michael , Horak Peter
Published: April 2023

Abstract
Tumor-initiating subpopulations of cancer cells, also known as cancer stem cells (CSC), were recently identified and characterized in prostate cancer. A well-characterized murine model of prostate cancer was used to investigate the regulation of hypoxia-inducible factor 1α (HIF1A/HIF1α) in CSCs and a basal stem cell subpopulation (Lin−/Sca-1+/CD49f+) was identified, in primary prostate tumors of mice, with elevated HIF1α expression. To further analyze the consequences of hypoxic upregulation on stem cell proliferation and HIF1α signaling, CSC subpopulations from murine TRAMP-C1 cells (Sca-1+/CD49f+) as well as from a human prostate cancer cell line (CD44+/CD49f+) were isolated and characterized. HIF1α levels and HIF target gene expression were elevated in hypoxic CSC-like cells, and upregulation of AKT occurred through a mechanism involving an mTOR/S6K/IRS-1 feedback loop. Interestingly, resistance of prostate CSCs to selective mTOR inhibitors was observed because of HIF1α upregulation. Thus, prostate CSCs show a hypoxic deactivation of a feedback inhibition of AKT signaling through IRS-1. In light of these results, we propose that deregulation of the PI3K/AKT/mTOR pathway through HIF1α is critical for CSC quiescence and maintenance by attenuating CSC metabolism and growth via mTOR and promoting survival by AKT signaling. We also propose that prostate CSCs can exhibit primary drug resistance to selective mTOR inhibitors.

Implications: This work contributes to a deeper understanding of hypoxic regulatory mechanisms in CSCs and will help devise novel therapies against prostate cancer. Mol Cancer Res; 13(3); 556–64. ©2014 AACR.
Data from Genome-Wide Analysis in a Murine Dnmt1 Knockdown Model Identifies Epigenetically Silenced Genes in Primary Human Pituitary Tumors
Authors: Dudley Kevin J. , Revill Kate , Whitby Philip , Clayton Richard N. , Farrell William E.
Published: April 2023

Abstract
DNA methylation at promoter CpG islands (CGI) is an epigenetic modification associated with inappropriate gene silencing in multiple tumor types. In the absence of a human pituitary tumor cell line, small interfering RNA–mediated knockdown of the maintenance methyltransferase DNA methyltransferase (cytosine 5)-1 (Dnmt1) was used in the murine pituitary adenoma cell line AtT-20. Sustained knockdown induced reexpression of the fully methylated and normally imprinted gene neuronatin (Nnat) in a time-dependent manner. Combined bisulfite restriction analysis (COBRA) revealed that reexpression of Nnat was associated with partial CGI demethylation, which was also observed at the H19 differentially methylated region. Subsequent genome-wide microarray analysis identified 91 genes that were significantly differentially expressed in Dnmt1 knockdown cells (10% false discovery rate). The analysis showed that genes associated with the induction of apoptosis, signal transduction, and developmental processes were significantly overrepresented in this list (P < 0.05). Following validation by reverse transcription-PCR and detection of inappropriate CGI methylation by COBRA, four genes (ICAM1, NNAT, RUNX1, and S100A10) were analyzed in primary human pituitary tumors, each displaying significantly reduced mRNA levels relative to normal pituitary (P < 0.05). For two of these genes, NNAT and S100A10, decreased expression was associated with increased promoter CGI methylation. Induced expression of Nnat in stable transfected AtT-20 cells inhibited cell proliferation. To our knowledge, this is the first report of array-based “epigenetic unmasking” in combination with Dnmt1 knockdown and reveals the potential of this strategy toward identifying genes silenced by epigenetic mechanisms across species boundaries. (Mol Cancer Res 2008;6(10):1567–74)
Data from Activation of Epidermal Growth Factor Receptor and Its Downstream Signaling Pathway by Nitric Oxide in Response to Ionizing Radiation
Authors: Lee Hyung-Chahn , An Sungkwan , Lee Hansoo , Woo Sang-Hyeok , Jin Hyeon-Ok , Seo Sung-Keum , Choe Tae-Boo , Yoo Doo-Hyun , Lee Su-Jae , Hong Young-Joon , Park Myung-Jin , Rhee Chang-Hun , Park In-Chul , Hong Seok-Il
Published: April 2023

Abstract
Epidermal growth factor receptor (EGFR) is activated by ionizing radiation (IR), but the molecular mechanism for this effect is unknown. We have found that intracellular generation of nitric oxide (NO) by NO synthase (NOS) is required for the rapid activation of EGFR phosphorylation by IR. Treatment of A549 lung cancer cells with IR increased NOS activity within minutes, accompanied by an increase of NO. 2-Phenyl-4,4,5,5,-tetramethylimidazolline-1-oxyl-3-oxide, an NO scavenger, and NG-monomethyl-l-arginine, an NOS inhibitor, abolished the increase in intracellular NO and activation of EGFR by IR. In addition, an NO donor alone induced EGFR phosphorylation. Transient transfection with small interfering RNA for endothelial NOS reduced IR-induced NO production and suppressed IR-induced EGFR activation. Overexpression of endothelial NOS increased IR-induced NO generation and EGFR activation. These results indicate a novel molecular mechanism for EGFR activation by IR-induced NO production via NOS. (Mol Cancer Res 2008;6(6):996–1002)
Data from FES Kinase Promotes Mast Cell Recruitment to Mammary Tumors via the Stem Cell Factor/KIT Receptor Signaling Axis
Authors: Kwok Ester , Everingham Stephanie , Zhang Shengnan , Greer Peter A. , Allingham John S. , Craig Andrew W.B.
Published: April 2023

Abstract
KIT receptor is required for mast cell development, survival, and migration toward its ligand stem cell factor (SCF). Many solid tumors express SCF and this leads to mast cell recruitment to tumors and release of mediators linked to tumor angiogenesis, growth, and metastasis. Here, we investigate whether FES protein-tyrosine kinase, a downstream effector of KIT signaling in mast cells, is required for migration of mast cells toward SCF-expressing mammary tumors. Using a novel agarose drop assay for chemotaxis of bone marrow–derived mast cells (BMMC) toward SCF, we found that defects in chemotaxis of fes-null BMMCs correlated with disorganized microtubule networks in polarized cells. FES displayed partial colocalization with microtubules in polarized BMMCs and has at least two direct microtubule binding sites within its N-terminal F-BAR and SH2 domains. An oligomerization-disrupting mutation within the Fer/CIP4 homology-Bin/Amphiphysin/Rvs (F-BAR) domain had no effect on microtubule binding, whereas microtubule binding to the SH2 domain was dependent on the phosphotyrosine-binding pocket. FES involvement in mast cell recruitment to tumors was tested using the AC2M2 mouse mammary carcinoma model. These tumor cells expressed SCF and promoted BMMC recruitment in a KIT- and FES-dependent manner. Engraftment of AC2M2 orthotopic and subcutaneous tumors in control or fes-null mice, revealed a key role for FES in recruitment of mast cells to the tumor periphery. This may contribute to the reduced tumor growth and metastases observed in fes-null mice compared with control mice. Taken together, FES is a potential therapeutic target to limit the progression of tumors with stromal mast cell involvement. Mol Cancer Res; 10(7); 881–91. ©2012 AACR.
Data from Disseminated Prostate Cancer Cells Can Instruct Hematopoietic Stem and Progenitor Cells to Regulate Bone Phenotype
Authors: Joseph Jeena , Shiozawa Yusuke , Jung Younghun , Kim Jin Koo , Pedersen Elisabeth , Mishra Anjali , Zalucha Janet Linn , Wang Jingcheng , Keller Evan T. , Pienta Kenneth J. , Taichman Russell S.
Published: April 2023

Abstract
Prostate cancer metastases and hematopoietic stem cells (HSC) frequently home to the bone marrow, where they compete to occupy the same HSC niche. We have also shown that under conditions of hematopoietic stress, HSCs secrete the bone morphogenetic proteins (BMP)-2 and BMP-6 that drives osteoblastic differentiation from mesenchymal precursors. As it is not known, we examined whether metastatic prostate cancer cells can alter regulation of normal bone formation by HSCs and hematopoietic progenitor cells (HPC). HSC/HPCs isolated from mice bearing nonmetastatic and metastatic tumor cells were isolated and their ability to influence osteoblastic and osteoclastic differentiation was evaluated. When the animals were inoculated with the LNCaP C4-2B cell line, which produces mixed osteoblastic and osteolytic lesions in bone, HPCs, but not HSCs, were able to induced stromal cells to differentiate down an osteoblastic phenotype. Part of the mechanism responsible for this activity was the production of BMP-2. On the other hand, when the animals were implanted with PC3 cells that exhibits predominantly osteolytic lesions in bone, HSCs derived from these animals were capable of directly differentiating into tartrate-resistant acid phosphatase–positive osteoclasts through an interleukin-6–mediated pathway. These studies for the first time identify HSC/HPCs as novel targets for future therapy involved in the bone abnormalities of prostate cancer. Mol Cancer Res; 10(3); 282–92. ©2012 AACR.
Data from Geldanamycin-Induced Down-Regulation of ErbB2 from the Plasma Membrane Is Clathrin Dependent but Proteasomal Activity Independent
Authors: Pedersen Nina Marie , Madshus Inger Helene , Haslekås Camilla , Stang Espen
Published: April 2023

Abstract
ErbB2, a member of the epidermal growth factor receptor family, is overexpressed in a number of human cancers. In contrast to the epidermal growth factor receptor, ErbB2 is normally endocytosis resistant. However, ErbB2 can be down-regulated by inhibitors of heat shock protein 90, such as geldanamycin. We now show that geldanamycin induces endocytosis and lysosomal degradation of full-length ErbB2. We further report that the endocytosis of ErbB2 is dynamin and clathrin dependent. When ErbB2 was retained at the plasma membrane due to knockdown of clathrin heavy chain, the intracellular part of ErbB2 was degraded in a proteasomal manner. However, our data strongly suggest that proteasomal activity is not required for geldanamycin-induced endocytosis of ErbB2 in SKBr3 cells. Interestingly, however, proteasomal inhibitors retarded degradation of ErbB2, and electron microscopy analysis strongly suggested that proteasomal activity is required to sort internalized ErbB2 to lysosomes. Because geldanamycin derivatives and inhibitors of proteasomal activity are both used in experimental cancer treatment, knowledge of molecular mechanisms involved in geldanamycin-induced down-regulation of ErbB2 is important for future design of cancer treatment. (Mol Cancer Res 2008;6(3):491–500)