bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Palbociclib Renders Human Papilloma Virus–Negative Head and Neck Squamous Cell Carcinoma Vulnerable to the Senolytic Agent Navitoclax
Authors: Gadsden Nicholas J. , Fulcher Cory D. , Li Daniel , Shrivastava Nitisha , Thomas Carlos , Segall Jeffrey E. , Prystowsky Michael B. , Schlecht Nicolas F. , Gavathiotis Evripidis , Ow Thomas J.
Published: March 2024

Abstract
We demonstrate that inhibition of cyclin-dependent kinases 4/6 (CDK4/6) leads to senescence in human papillomavirus (HPV)–negative (−) head and neck squamous cell carcinoma (HNSCC), but not in HPV-positive (+) HNSCC. The BCL-2 family inhibitor, navitoclax, has been shown to eliminate senescent cells effectively. We evaluated the efficacy of combining palbociclib and navitoclax in HPV− HNSCC. Three HPV− HNSCC cell lines (CAL27, HN31, and PCI15B) and three HPV+ HNSCC cell lines (UPCI-SCC-090, UPCI-SCC-154, and UM-SCC-47) were treated with palbociclib. Treatment drove reduced expression of phosphorylated Rb (p-Rb) and phenotypic evidence of senescence in all HPV− cell lines, whereas HPV+ cell lines did not display a consistent response by Rb or p-Rb and did not exhibit morphologic changes of senescence in response to palbociclib. In addition, treatment of HPV− cells with palbociclib increased both β-galactosidase protein expression and BCL-xL protein expression compared with untreated controls in HPV− cells. Co-expression of β-galactosidase and BCL-xL occurred consistently, indicating elevated BCL-xL expression in senescent cells. Combining palbociclib with navitoclax led to decreased HPV− HNSCC cell survival and led to increased apoptosis levels in HPV− cell lines compared with each agent given alone.
Implications:
This work exploits a key genomic hallmark of HPV− HNSCC (CDKN2A disruption) using palbociclib to induce BCL-xL–dependent senescence, which subsequently causes the cancer cells to be vulnerable to the senolytic agent, navitoclax.
Data from Hypoxic Induction of Exosome Uptake through Proteoglycan-Dependent Endocytosis Fuels the Lipid Droplet Phenotype in Glioma
Authors: Cerezo-Magaña Myriam , Christianson Helena C. , van Kuppevelt Toin H. , Forsberg-Nilsson Karin , Belting Mattias
Published: March 2024

Abstract
As an adaptive response to hypoxic stress, aggressive tumors rewire their metabolic phenotype into increased malignant behavior through extracellular lipid scavenging and storage in lipid droplets (LD). However, the underlying mechanisms and potential lipid source retrieved in the hypoxic tumor microenvironment remain poorly understood. Here, we show that exosome-like extracellular vesicles (EV), known as influential messengers in the tumor microenvironment, may also serve anabolic functions by transforming hypoxic, patient-derived human glioblastoma cell lines into the LD+ phenotype. EVs were internalized via a hypoxia-sensitive, endocytic mechanism that fueled LD formation through direct lipid transfer, and independently of fatty acid synthase activity. EVs can enter cells through multiple and yet ill-defined pathways. On a mechanistic level, we found that hypoxia-mediated EV uptake depends on increased heparan sulfate proteoglycan (HSPG) endocytosis that preferentially followed the lipid raft pathway. The functional relevance of HSPG was evidenced by the reversal of EV-mediated LD loading by targeting of HSPG receptor function.
Implications:
Together, our data extend the multifaceted role of EVs in cancer biology by showing their LD-inducing capacity in hypoxic glioma cells. Moreover, these findings highlight a potential function for HSPG-mediated endocytosis as a salvage pathway for EV retrieval during tumor stress conditions.
Data from Oncogenic Gene-Expression Programs in Leiomyosarcoma and Characterization of Conventional, Inflammatory, and Uterogenic Subtypes
Authors: Hemming Matthew L. , Fan Changyu , Raut Chandrajit P. , Demetri George D. , Armstrong Scott A. , Sicinska Ewa , George Suzanne
Published: March 2024

Abstract
Leiomyosarcoma (LMS) is a mesenchymal neoplasm with complex copy-number alterations and characteristic loss of tumor suppressor genes without known recurrent activating mutations. Clinical management of advanced LMS relies on chemotherapy and complementary palliative approaches, and research efforts to date have had limited success identifying clinically actionable biomarkers or targeted therapeutic vulnerabilities. To explore the biological underpinning of LMS, we evaluated gene-expression patterns of this disease in comparison with diverse sarcomas, nonmesenchymal neoplasms, and normal myogenic tissues. We identified a recurrent gene-expression program in LMS, with evidence of oncogenic evolution of an underlying smooth-muscle lineage-derived program characterized by activation of E2F1 and downstream effectors. Recurrently amplified or highly expressed genes in LMS were identified, including IGF1R and genes involved in retinoid signaling pathways. Though the majority of expressed transcripts were conserved across LMS samples, three separate subtypes were identified that were enriched for muscle-associated transcripts (conventional LMS), immune markers (inflammatory LMS), or a uterine-like gene-expression program (uterogenic LMS). Each of these subtypes expresses a unique subset of genes that may be useful in the management of LMS: IGF1R was enriched in conventional LMS, worse disease-specific survival was observed in inflammatory LMS, and prolactin was elaborated by uterogenic LMS. These results extend our understanding of LMS biology and identify several strategies and challenges for further translational investigation.
Implications:
LMS has a recurrent oncogenic transcriptional program and consists of molecular subtypes with biological and possible clinical implications.
Data from Mutant p53 Attenuates Oxidative Phosphorylation and Facilitates Cancer Stemness through Downregulating miR-200c–PCK2 Axis in Basal-Like Breast Cancer
Authors: Chao Chi-Hong , Wang Chen-Yun , Wang Cing-Hong , Chen Ting-Wen , Hsu Huai-Yu , Huang Hao-Wei , Li Chia-Wei , Mai Ru-Tsun
Published: March 2024

Abstract
miR-200c is a tumor suppressor miRNA that plays a critical role in regulating epithelial phenotype and cancer stemness. p53 deficiency downregulates the expression of miR-200c and leads to epithelial-mesenchymal transition (EMT) and stemness phenotype, which contributes to the progression of breast cancers. In this study, we demonstrated that CRISPR-mediated knockout (KO) of miR-200c induces metabolic features similar to the metabolic rewiring caused by p53 hot-spot mutations, and that impairing this metabolic reprogramming interferes with miR-200c deficiency–induced stemness and transformation. Moreover, restoring miR-200c expression compromised EMT, stem-cell properties, and the Warburg effect caused by p53 mutations, suggesting that mutant p53 (MTp53) induces EMT-associated phenotypes and metabolic reprogramming by downregulating miR-200c. Mechanistically, decreased expression of PCK2 was observed in miR-200c– and p53-deficient mammary epithelial cells, and forced expression of miR-200c restored PCK2 in p53 mutant–expressing cells. Reduced PCK2 expression not only led to attenuated oxidative phosphorylation (OXPHOS) and increased stemness in normal mammary epithelial cells but also compromised the enhanced OXPHOS and suppression of cancer stemness exerted by miR-200c in p53 mutation–bearing basal-like breast cancer (BLBC) cells. Clinically, PCK2 expression is negatively associated with EMT markers and is downregulated in basal-like subtype and cases with low miR-200c expression or p53 mutation. Notably, low expression of PCK2 is associated with poor overall survival (OS) in patients with breast cancer.
Implications:
Together, our results suggest that p53 and miR-200c regulate OXPHOS and stem/cancer stemness through PCK2, and loss of the p53–miR-200c–PCK2 axis might provide metabolic advantages that facilitate cancer stemness, leading to the progression of BLBCs.
Data from Quantitative Longitudinal Imaging Reveals that Inhibiting Hedgehog Activity Alleviates the Hypoxic Tumor Landscape
Authors: Lama-Sherpa Tshering D. , Das Shamik , Hinshaw Dominique C. , Kammerud Sarah C. , Song Patrick N. , Alsheikh Heba A. , Sorace Anna G. , Samant Rajeev S. , Shevde Lalita A.
Published: March 2024

Abstract
Metastases account for the majority of mortalities related to breast cancer. The onset and sustained presence of hypoxia strongly correlates with increased incidence of metastasis and unfavorable prognosis in patients with breast cancer. The Hedgehog (Hh) signaling pathway is dysregulated in breast cancer, and its abnormal activity enables tumor progression and metastasis. In addition to programming tumor cell behavior, Hh activity enables tumor cells to craft a metastasis-conducive microenvironment. Hypoxia is a prominent feature of growing tumors that impacts multiple signaling circuits that converge upon malignant progression. We investigated the role of Hh activity in crafting a hypoxic environment of breast cancer. We used radioactive tracer [18F]-fluoromisonidazole (FMISO) positron emission tomography (PET) to image tumor hypoxia. We show that tumors competent for Hh activity are able to establish a hypoxic milieu; pharmacologic inhibition of Hh signaling in a syngeneic mammary tumor model mitigates tumor hypoxia. Furthermore, in hypoxia, Hh activity is robustly activated in tumor cells and institutes increased HIF signaling in a VHL-dependent manner. The findings establish a novel perspective on Hh activity in crafting a hypoxic tumor landscape and molecularly navigating the tumor cells to adapt to hypoxic conditions.

Implications: Importantly, we present a translational strategy of utilizing longitudinal hypoxia imaging to measure the efficacy of vismodegib in a preclinical model of triple-negative breast cancer.
Data from Radiomics Biomarkers Correlate with CD8 Expression and Predict Immune Signatures in Melanoma Patients
Authors: Aoude Lauren G. , Wong Bernadette Z.Y. , Bonazzi Vanessa F. , Brosda Sandra , Walters Shaun B. , Koufariotis Lambros T. , Naeini Marjan M. , Pearson John V. , Oey Harald , Patel Kalpana , Bradford Julia J. , Bloxham Conor J. , Atkinson Victoria , Law Phillip , Strutton Geoffrey , Bayley Gerard , Yang Samuel , Smithers B. Mark , Waddell Nicola , Miles Kenneth , Barbour Andrew P.
Published: March 2024

Abstract
Treatment for metastatic melanoma includes targeted and/or immunotherapy. Although many patients respond, only a subset has complete response. As late-stage patients often have multiple tumors in difficult access sites, non-invasive techniques are necessary for the development of predictive/prognostic biomarkers. PET/CT scans from 52 patients with stage III/IV melanoma were assessed and CT image parameters were evaluated as prognostic biomarkers. Analysis indicated patients with high standard deviation or high mean of positive pixels (MPP) had worse progression-free survival (P = 0.00047 and P = 0.0014, respectively) and worse overall survival (P = 0.0223 and P = 0.0465, respectively). Whole-exome sequencing showed high MPP was associated with BRAF mutation status (P = 0.0389). RNA-sequencing indicated patients with immune “cold” signatures had worse survival, which was associated with CT biomarker, MPP4 (P = 0.0284). Multiplex immunofluorescence confirmed a correlation between CD8 expression and image biomarkers (P = 0.0028).
Implications:
CT parameters have the potential to be cost-effective biomarkers of survival in melanoma, and reflect the tumor immune-microenvironment.
Data from Studying Immunotherapy Resistance in a Melanoma Autologous Humanized Mouse Xenograft
Authors: Morton J. Jason , Alzofon Nathaniel , Keysar Stephen B. , Chimed Tugs-Saikhan , Reisinger Julie , Perrenoud Loni , Le Phuong N. , Nieto Cera , Gomez Karina , Miller Bettina , Yeager Randi , Gao Dexiang , Tan Aik-Choon , Somerset Hilary , Medina Theresa , Wang Xiao-Jing , Wang Jing H. , Robinson William , Roop Dennis R. , Gonzalez Rene , Jimeno Antonio
Published: March 2024

Abstract
Resistance to immunotherapy is a significant challenge, and the scarcity of human models hinders the identification of the underlying mechanisms. To address this limitation, we constructed an autologous humanized mouse (aHM) model with hematopoietic stem and progenitor cells (HSPC) and tumors from 2 melanoma patients progressing to immunotherapy. Unlike mismatched humanized mouse (mHM) models, generated from cord blood–derived HSPCs and tumors from different donors, the aHM recapitulates a patient-specific tumor microenvironment (TME). When patient tumors were implanted on aHM, mHM, and NOD/SCID/IL2rg−/− (NSG) cohorts, tumors appeared earlier and grew faster on NSG and mHM cohorts. We observed that immune cells differentiating in the aHM were relatively more capable of circulating peripherally, invading into tumors and interacting with the TME. A heterologous, human leukocyte antigen (HLA-A) matched cohort also yielded slower growing tumors than non–HLA-matched mHM, indicating that a less permissive immune environment inhibits tumor progression. When the aHM, mHM, and NSG cohorts were treated with immunotherapies mirroring what the originating patients received, tumor growth in the aHM accelerated, similar to the progression observed in the patients. This rapid growth was associated with decreased immune cell infiltration, reduced interferon gamma (IFNγ)–related gene expression, and a reduction in STAT3 phosphorylation, events that were replicated in vitro using tumor-derived cell lines.
Implications:
Engrafted adult HSPCs give rise to more tumor infiltrative immune cells, increased HLA matching leads to slower tumor initiation and growth, and continuing immunotherapy past progression can paradoxically lead to increased growth.
Data from SHOC2 Is a Critical Modulator of Sensitivity to EGFR–TKIs in Non–Small Cell Lung Cancer Cells
Authors: Terai Hideki , Hamamoto Junko , Emoto Katsura , Masuda Takeshi , Manabe Tadashi , Kuronuma Satoshi , Kobayashi Keigo , Masuzawa Keita , Ikemura Shinnosuke , Nakayama Sohei , Kawada Ichiro , Suzuki Yusuke , Takeuchi Osamu , Suzuki Yukio , Ohtsuki Sumio , Yasuda Hiroyuki , Soejima Kenzo , Fukunaga Koichi
Published: March 2024

Abstract
EGFR mutation-positive patients with non–small cell lung cancer (NSCLC) respond well to treatment with EGFR–tyrosine kinase inhibitors (EGFR–TKI); however, treatment with EGFR–TKIs is not curative, owing to the presence of residual cancer cells with intrinsic or acquired resistance to this class of drugs. Additional treatment targets that may enhance the efficacy of EGFR–TKIs remain elusive. Using a CRISPR/Cas9-based screen, we identified the leucine-rich repeat scaffold protein SHOC2 as a key modulator of sensitivity to EGFR–TKI treatment. On the basis of in vitro assays, we demonstrated that SHOC2 expression levels strongly correlate with the sensitivity to EGFR–TKIs and that SHOC2 affects the sensitivity to EGFR–TKIs in NSCLC cells via SHOC2/MRAS/PP1c and SHOC2/SCRIB signaling. The potential SHOC2 inhibitor celastrol phenocopied SHOC2 depletion. In addition, we confirmed that SHOC2 expression levels were important for the sensitivity to EGFR–TKIs in vivo. Furthermore, IHC showed the accumulation of cancer cells that express high levels of SHOC2 in lung cancer tissues obtained from patients with NSCLC who experienced acquired resistance to EGFR–TKIs. These data indicate that SHOC2 may be a therapeutic target for patients with NSCLC or a biomarker to predict sensitivity to EGFR–TKI therapy in EGFR mutation-positive patients with NSCLC. Our findings may help improve treatment strategies for patients with NSCLC harboring EGFR mutations.
Implications:
This study showed that SHOC2 works as a modulator of sensitivity to EGFR–TKIs and the expression levels of SHOC2 can be used as a biomarker for sensitivity to EGFR–TKIs.
Data from Mastermind Like Transcriptional Coactivator 3 (MAML3) Drives Neuroendocrine Tumor Progression
Authors: Alzofon Nathaniel , Koc Katrina , Panwell Kristin , Pozdeyev Nikita , Marshall Carrie B. , Albuja-Cruz Maria , Raeburn Christopher D. , Nathanson Katherine L. , Cohen Debbie L. , Wierman Margaret E. , Kiseljak-Vassiliades Katja , Fishbein Lauren
Published: March 2024

Abstract
Metastatic disease in pheochromocytomas and paragangliomas (PCC/PGL) is not well-understood. The Cancer Genome Atlas discovered recurrent MAML3 fusion genes in a subset of tumors that lacked known germline or somatic driver mutations and were associated with aggressive disease. Here, we aimed to investigate the role of MAML3 in tumorigenesis. Human PCC/PGLs were used for IHC and genetic analysis. Three neuroendocrine tumor cell lines, SK-N-SH, QGP-1, and BON-1, were transiently transfected with MAML3 (FL) or exon 1 deleted MAML3 (dEx1; mimicking the fusion), and biologic effects of overexpression were examined in vitro. We found 7% (4/55) of human PCC/PGL have UBTF∼MAML3 fusions and all were sporadic cases with metastatic disease. Fusion-positive tumors had intense MAML3 nuclear staining and increased β-catenin by IHC and showed increased WNT4 expression. In vitro, overexpression of FL and dEx1 MAML3 increased invasion in SK-N-SH, QGP-1, and BON-1 (all P < 0.05) and increased soft-agar colony formation in QGP-1 and BON-1 (all P < 0.05). Cotransfection with FL or dEx1 MAML3 and β-catenin increased TCF/LEF promoter activation by luciferase activity and coimmunoprecipitation confirmed interaction between MAML3 and β-catenin. These data suggest MAML3 is involved in WNT signaling pathway activation. In summary, UBTF∼MAML3 fusions are present in a subset of PCC/PGL and associated with metastatic disease without other known drivers. MAML3 overexpression led to increased tumorigenicity in neuroendocrine tumor cells and the mechanism of action may involve WNT signaling pathways.
Implications:
MAML3 increases tumorigenicity and invasion in neuroendocrine tumor cells and may be a prognostic marker for aggressive disease.
Data from Adipokine Apelin/APJ Pathway Promotes Peritoneal Dissemination of Ovarian Cancer Cells by Regulating Lipid Metabolism
Authors: Dogra Samrita , Neelakantan Deepika , Patel Maulin M. , Griesel Beth , Olson Ann , Woo Sukyung
Published: March 2024

Abstract
Adipose tissue, which can provide adipokines and nutrients to tumors, plays a key role in promoting ovarian cancer metastatic lesions in peritoneal cavity. The adipokine apelin promotes ovarian cancer metastasis and progression through its receptor APJ, which regulates cell proliferation, energy metabolism, and angiogenesis. The objective of this study was to investigate the functional role and mechanisms of the apelin-APJ pathway in ovarian cancer metastasis, especially in context of tumor cell–adipocyte interactions. When co-cultured in the conditioned media (AdipoCM) derived from 3T3-L1 adipocytes, which express and secrete high apelin, human ovarian cancer cells with high APJ expression showed significant increases in migration and invasion in vitro. We also found that cells expressing high levels of APJ had increased cell adhesion to omentum ex vivo, and preferentially “home-in” on the omentum in vivo. These apelin-induced pro-metastatic effects were reversed by APJ antagonist F13A in a dose-dependent manner. Apelin-APJ activation increased lipid droplet accumulation in ovarian cancer cells, which was further intensified in the presence of AdipoCM and reversed by F13A or APJ knockdown. Mechanistically, this increased lipid uptake was mediated by CD36 upregulation via APJ-STAT3 activation, and the lipids were utilized in promoting fatty acid oxidation via activation of AMPK-CPT1a axis. Together, our studies demonstrate that adipocyte-derived apelin activates APJ-expressing tumor cells in a paracrine manner, promoting lipid uptake and utilization and providing energy for ovarian cancer cell survival at the metastatic sites. Hence, the apelin-APJ pathway presents a novel therapeutic target to curb ovarian cancer metastasis.
Implications:
Targeting the APJ pathway in high-grade serous ovarian carcinoma is a novel strategy to inhibit peritoneal metastasis.
Data from IQ Motif-Containing GTPase-Activating Protein 2 Inhibits Breast Cancer Angiogenesis by Suppressing VEGFR2–AKT Signaling
Authors: Kumar Dinesh , Patel Saket Awadhesbhai , Khan Rehan , Chawla Saurabh , Mohapatra Nachiketa , Dixit Manjusha
Published: March 2024

Abstract
Antiangiogenesis cancer therapies are facing setbacks due to side effects and resistance. Parallel targeting of multiple pathways can help in the development of more effective therapies. This requires the discovery of new molecules that can regulate multiple cellular processes. Our study has recently established the association of reduced IQGAP2 expression in breast cancer with EMT and poor prognosis of the patient. Existing literature indirectly suggests the role of IQGAP2 in angiogenesis that is still unexplored. In this study, we searched the role of IQGAP2 in tumor angiogenesis in a comprehensive manner using cell culture, patients, and animal models. Depletion of IQGAP2 in breast cancer cells increased proliferation, migration, and tubulogenesis of HUVECs. Findings were validated in ex ovo CAM, Matrigel plug and skin wound-healing assays in mouse model, showing that the reduction of IQGAP2 significantly increased angiogenesis. As a confirmation, IHC analysis of the patient's tissues showed a negative correlation of IQGAP2 expression with the microvessel density. Mechanistically, loss of IQGAP2 appeared to activate VEGF-A via ERK activation in tumor cells, which activated the VEGFR2–AKT axis in HUVECs.
Implications:
The findings of this study suggest the antiangiogenic properties of IQGAP2 in breast cancer. The Dual effect of IQGAP2 on EMT and angiogenesis makes it a potential target for anticancer therapy.
Data from Role of TET1 and 5hmC in an Obesity-Linked Pathway Driving Cancer Stem Cells in Triple-Negative Breast Cancer
Authors: Bao Bin , Teslow Emily A. , Mitrea Cristina , Boerner Julie L. , Dyson Greg , Bollig-Fischer Aliccia
Published: March 2024

Abstract
Triple-negative breast cancer (TNBC) is a subtype of breast cancer that lacks expression of estrogen receptor, progesterone receptor, and the HER2 but is enriched with cancer stem cell–like cells (CSC). CSCs are the fraction of cancer cells recognized as the source of primary malignant tumors that also give rise to metastatic recurrence. 5-Hydroxymethylcytosine (5hmC) is a DNA epigenetic feature derived from 5-methylcytosine by action of tet methylcytosine dioxygenase enzymes (e.g., TET1); and although TET1 and 5hmC are required to maintain embryonic stem cells, the mechanism and role in CSCs remain unknown. Data presented in this report support the conclusion that TET1 and TET1-dependent 5hmC mediate hydrogen peroxide (H2O2)–dependent activation of a novel gene expression cascade driving self-renewal and expansion of CSCs in TNBC. Evidence presented also supports that the H2O2 affecting this pathway arises due to endogenous mechanisms—including downregulation of antioxidant enzyme catalase in TNBC cells—and by exogenous routes, such as systemic inflammation and oxidative stress coupled with obesity, a known risk factor for TNBC incidence and recurrence.
Implications:
This study elucidates a pathway dependent on H2O2 and linked to obesity-driven TNBC tumor-initiating CSCs; thus, it provides new understanding that may advance TNBC prevention and treatment strategies.
Data from Autophagy-Dependent Sensitization of Triple-Negative Breast Cancer Models to Topoisomerase II Poisons by Inhibition of the Nucleosome Remodeling Factor
Authors: Tyutyunyk-Massey Liliya , Sun Yilun , Dao Nga , Ngo Hannah , Dammalapati Mallika , Vaidyanathan Ashish , Singh Manjulata , Haqqani Syed , Haueis Joshua , Finnegan Ryan , Deng Xiaoyan , Kirberger Steve E. , Bos Paula D. , Bandyopadhyay Dipankar , Pomerantz William C.K. , Pommier Yves , Gewirtz David A. , Landry Joseph W.
Published: March 2024

Abstract
Epigenetic regulators can modulate the effects of cancer therapeutics. To further these observations, we discovered that the bromodomain PHD finger transcription factor subunit (BPTF) of the nucleosome remodeling factor (NURF) promotes resistance to doxorubicin, etoposide, and paclitaxel in the 4T1 breast tumor cell line. BPTF functions in promoting resistance to doxorubicin and etoposide, but not paclitaxel, and may be selective to cancer cells, as a similar effect was not observed in embryonic stem cells. Sensitization to doxorubicin and etoposide with BPTF knockdown (KD) was associated with increased DNA damage, topoisomerase II (TOP2) crosslinking and autophagy; however, there was only a modest increase in apoptosis and no increase in senescence. Sensitization to doxorubicin was confirmed in vivo with the syngeneic 4T1 breast tumor model using both genetic and pharmacologic inhibition of BPTF. The effects of BPTF inhibition in vivo are autophagy dependent, based on genetic autophagy inhibition. Finally, treatment of 4T1, 66cl4, 4T07, MDA-MB-231, but not ER-positive 67NR and MCF7 breast cancer cells with the selective BPTF bromodomain inhibitor, AU1, recapitulates genetic BPTF inhibition, including in vitro sensitization to doxorubicin, increased TOP2-DNA crosslinks and DNA damage. Taken together, these studies demonstrate that BPTF provides resistance to the antitumor activity of TOP2 poisons, preventing the resolution of TOP2 crosslinking and associated autophagy. These studies suggest that BPTF can be targeted with small-molecule inhibitors to enhance the effectiveness of TOP2-targeted cancer chemotherapeutic drugs.
Implications:
These studies suggest NURF can be inhibited pharmacologically as a viable strategy to improve chemotherapy effectiveness.
Data from R-Loop–Mediated ssDNA Breaks Accumulate Following Short-Term Exposure to the HDAC Inhibitor Romidepsin
Authors: Safari Maryam , Litman Thomas , Robey Robert W. , Aguilera Andrés , Chakraborty Arup R. , Reinhold William C. , Basseville Agnes , Petrukhin Lubov , Scotto Luigi , O'Connor Owen A. , Pommier Yves , Fojo Antonio T. , Bates Susan E.
Published: March 2024

Abstract
Histone deacetylase inhibitors (HDACi) induce hyperacetylation of histones by blocking HDAC catalytic sites. Despite regulatory approvals in hematological malignancies, limited solid tumor clinical activity has constrained their potential, arguing for better understanding of mechanisms of action (MOA). Multiple activities of HDACis have been demonstrated, dependent on cell context, beyond the canonical induction of gene expression. Here, using a clinically relevant exposure duration, we established DNA damage as the dominant signature using the NCI-60 cell line database and then focused on the mechanism by which hyperacetylation induces DNA damage. We identified accumulation of DNA–RNA hybrids (R-loops) following romidepsin-induced histone hyperacetylation, with single-stranded DNA (ssDNA) breaks detected by single-cell electrophoresis. Our data suggest that transcription-coupled base excision repair (BER) is involved in resolving ssDNA breaks that, when overwhelmed, evolve to lethal dsDNA breaks. We show that inhibition of BER proteins such as PARP will increase dsDNA breaks in this context. These studies establish accumulation of R-loops as a consequence of romidepsin-mediated histone hyperacetylation. We believe that the insights provided will inform design of more effective combination therapy with HDACis for treatment of solid tumors.
Implications:
Key HDAC inhibitor mechanisms of action remain unknown; we identify accumulation of DNA–RNA hybrids (R-loops) due to chromatin hyperacetylation that provokes single-stranded DNA damage as a first step toward cell death.
Data from Thyroid Hormone Receptor Beta Induces a Tumor-Suppressive Program in Anaplastic Thyroid Cancer
Authors: Bolf Eric L. , Gillis Noelle E. , Davidson Cole D. , Rodriguez Princess D. , Cozzens Lauren , Tomczak Jennifer A. , Frietze Seth , Carr Frances E.
Published: March 2024

Abstract
The thyroid hormone receptor beta (TRβ), a key regulator of cellular growth and differentiation, is frequently dysregulated in cancers. Diminished expression of TRβ is noted in thyroid, breast, and other solid tumors and is correlated with more aggressive disease. Restoration of TRβ levels decreased tumor growth supporting the concept that TRβ could function as a tumor suppressor. Yet, the TRβ tumor suppression transcriptome is not well delineated and the impact of TRβ is unknown in aggressive anaplastic thyroid cancer (ATC). Here, we establish that restoration of TRβ expression in the human ATC cell line SW1736 (SW-TRβ) reduces the aggressive phenotype, decreases cancer stem cell populations and induces cell death in a T3-dependent manner. Transcriptomic analysis of SW-TRβ cells via RNA sequencing revealed distinctive expression patterns induced by ligand-bound TRβ and revealed novel molecular signaling pathways. Of note, liganded TRβ repressed multiple nodes in the PI3K/AKT pathway, induced expression of thyroid differentiation markers, and promoted proapoptotic pathways. Our results further revealed the JAK1–STAT1 pathway as a novel, T3-mediated, antitumorigenic pathway that can be activated in additional ATC lines. These findings elucidate a TRβ-driven tumor suppression transcriptomic signature, highlight unexplored therapeutic options for ATC, and support TRβ activation as a promising therapeutic option in cancers.
Implications:
TRβ-T3 induced a less aggressive phenotype and tumor suppression program in anaplastic thyroid cancer cells revealing new potential therapeutic targets.
Data from Distinct Biomarker Profiles and TCR Sequence Diversity Characterize the Response to PD-L1 Blockade in a Mouse Melanoma Model
Authors: El Meskini Rajaa , Atkinson Devon , Kulaga Alan , Abdelmaksoud Abdalla , Gumprecht Michelle , Pate Nathan , Hayes Susana , Oberst Michael , Kaplan Ian M. , Raber Patrick , Van Dyke Terry , Sharan Shyam K. , Hollingsworth Robert , Day Chi-Ping , Merlino Glenn , Weaver Ohler Zoë
Published: March 2024

Abstract
Only a subset of patients responds to immune checkpoint blockade (ICB) in melanoma. A preclinical model recapitulating the clinical activity of ICB would provide a valuable platform for mechanistic studies. We used melanoma tumors arising from an Hgftg;Cdk4R24C/R24C genetically engineered mouse (GEM) model to evaluate the efficacy of an anti–mouse PD-L1 antibody similar to the anti–human PD-L1 antibodies durvalumab and atezolizumab. Consistent with clinical observations for ICB in melanoma, anti–PD-L1 treatment elicited complete and durable response in a subset of melanoma-bearing mice. We also observed tumor growth delay or regression followed by recurrence. For early treatment assessment, we analyzed gene expression profiles, T-cell infiltration, and T-cell receptor (TCR) signatures in regressing tumors compared with tumors exhibiting no response to anti–PD-L1 treatment. We found that CD8+ T-cell tumor infiltration corresponded to response to treatment, and that anti–PD-L1 gene signature response indicated an increase in antigen processing and presentation, cytokine–cytokine receptor interaction, and natural killer cell–mediated cytotoxicity. TCR sequence data suggest that an anti–PD-L1–mediated melanoma regression response requires not only an expansion of the TCR repertoire that is unique to individual mice, but also tumor access to the appropriate TCRs. Thus, this melanoma model recapitulated the variable response to ICB observed in patients and exhibited biomarkers that differentiate between early response and resistance to treatment, providing a valuable platform for prediction of successful immunotherapy.
Implications:
Our melanoma model recapitulates the variable response to anti–PD-L1 observed in patients and exhibits biomarkers that characterize early antibody response, including expansion of the TCR repertoire.
Data from Circulating Tumor Cell Genomic Evolution and Hormone Therapy Outcomes in Men with Metastatic Castration-Resistant Prostate Cancer
Authors: Gupta Santosh , Halabi Susan , Kemeny Gabor , Anand Monika , Giannakakou Paraskevi , Nanus David M. , George Daniel J. , Gregory Simon G. , Armstrong Andrew J.
Published: March 2024

Abstract
Men with circulating tumor cell (CTC) AR-V7–positive metastatic castration-resistant prostate cancer (mCRPC) have worse outcomes when treated with enzalutamide/abiraterone. However, most men lack CTC AR-V7 detection, and additional predictive biomarkers are needed. We conducted a retrospective secondary analysis of the prospective PROPHECY trial (NCT02269982) of men with mCRPC undergoing treatment with enzalutamide/abiraterone, analyzing pooled CTC and germline DNA for whole-genome copy-number alterations (CNA) in 73 samples from 48 men over time along with pooled CTC and germline whole-exome sequencing on 22 paired samples before and following progression on androgen receptor (AR) inhibitor therapy to identify somatic genomic alterations associated with acquired resistance. We observed broad interpatient and longitudinal CTC genomic heterogeneity from AR-V7–negative men with mCRPC, including common gains of KDM6A, MYCN, and AR, and loss of ZFHX3, BRCA1, and PTEN. Men who had progression-free survival of ≤3 months despite enzalutamide/abiraterone treatment were more likely to have baseline CTC genomic loss of CHD1, PTEN, PHLPP1, and ZFHX3 and gains of BRCA2, KDM5D, MYCN, and SPARC. After progression on abiraterone/enzalutamide, we observed clonal evolution of CTCs harboring TP53 mutations and gain of ATM, KDM6A, and MYC, and loss of NCOR1, PTEN, RB1, and RUNX2. CTC genomic findings were independently confirmed in a separate cohort of mCRPC men who progressed despite prior treatment with abiraterone/enzalutamide (NCT02204943).
Implications:
We identified common and reproducible genomic alterations in CTCs from AR-V7–negative mCRPC men associated with poor outcomes during enzalutamide/abiraterone treatment, including CNAs in genes linked to lineage plasticity and epigenetic signaling, DNA repair, AR, TP53/RB1, PTEN, and WNT pathways.
Data from MUC16 Promotes Liver Metastasis of Pancreatic Ductal Adenocarcinoma by Upregulating NRP2-Associated Cell Adhesion
Authors: Marimuthu Saravanakumar , Lakshmanan Imayavaramban , Muniyan Sakthivel , Gautam Shailendra K. , Nimmakayala Rama Krishna , Rauth Sanchita , Atri Pranita , Shah Ashu , Bhyravbhatla Namita , Mallya Kavita , Grandgenett Paul M. , Hollingsworth Michael A. , Datta Kaustubh , Jain Maneesh , Ponnusamy Moorthy P. , Batra Surinder K.
Published: March 2024

Abstract
Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal types of cancer, as it commonly metastasizes to the liver resulting in an overall poor prognosis. However, the molecular mechanism involved in liver metastasis remains poorly understood. Here, we aimed to identify the MUC16-mediated molecular mechanism of PDAC-liver metastasis. Previous studies demonstrated that MUC16 and its C-terminal (Cter) domain are involved in the aggressiveness of PDAC. In this study, we observed MUC16 and its Cter expression significantly high in human PDAC tissues, PDAC organoids, and metastatic liver tissues, while no expression was observed in normal pancreatic tissues using IHC and immunofluorescence (IFC) analyses. MUC16 knockdown in SW1990 and CD18/HPAF PDAC cells significantly decreased the colony formation, migration, and endothelial/p-selectin binding. In contrast, MUC16-Cter ectopic overexpression showed significantly increased colony formation and motility in MiaPaCa2 pancreatic cancer cells. Interestingly, MUC16 promoted cell survival and colonization in the liver, mimicking an ex vivo environment. Furthermore, MUC16 enhanced liver metastasis in the in vivo mouse model. Our integrated analyses of RNA-sequencing suggested that MUC16 alters Neuropilin-2 (NRP2) and cell adhesion molecules in pancreatic cancer cells. Furthermore, we identified that MUC16 regulated NRP2 via JAK2/STAT1 signaling in PDAC. NRP2 knockdown in MUC16-overexpressed PDAC cells showed significantly decreased cell adhesion and migration. Overall, the findings indicate that MUC16 regulates NRP2 and induces metastasis in PDAC.
Implications:
This study shows that MUC16 plays a critical role in PDAC liver metastasis by mediating NRP2 regulation by JAK2/STAT1 axis, thereby paving the way for future therapy efforts for metastatic PDAC.
Data from The Lack, Need, and Opportunities for Decision-Making and Informational Tools to Educate Primary-Care Physicians and Women about Breast Cancer Chemoprevention
Authors: Ravdin Peter M.
Published: March 2024

Abstract
This perspective on Vogel et al. (beginning on page 696 in this issue of the journal) examines tamoxifen and raloxifene prescription patterns and why these agents are little used for breast cancer prevention despite their effectiveness in definitive trials, Food and Drug Administration approval, and American Society of Clinical Oncology Guidelines Committee endorsement for this purpose. The complexity of weighing the positive and negative aspects of the drugs and estimating net benefit is discussed, as is the need for informational resources such as interactive Internet-based tools to allow better individualized decisions about the options for chemoprevention. Cancer Prev Res; 3(6); 686–8. ©2010 AACR.
Data from Loss of Heterozygosity (LOH) Profiles—Validated Risk Predictors for Progression to Oral Cancer
Authors: Zhang Lewei , Poh Catherine F. , Williams Michele , Laronde Denise M. , Berean Ken , Gardner Pamela J. , Jiang Huijun , Wu Lang , Lee J. Jack , Rosin Miriam P.
Published: March 2024

Abstract
A major barrier to oral cancer prevention has been the lack of validated risk predictors for oral premalignant lesions (OPL). In 2000, we proposed a loss of heterozygosity (LOH) risk model in a retrospective study. This paper validated the previously reported LOH profiles as risk predictors and developed refined models via the largest longitudinal study to date of low-grade OPLs from a population-based patient group. Analysis involved a prospective cohort of 296 patients with primary mild/moderate oral dysplasia enrolled in the Oral Cancer Prediction Longitudinal Study. LOH status was determined in these OPLs. Patients were classified into high-risk or low-risk profiles to validate the 2000 model. Risk models were refined using recursive partitioning and Cox regression analyses. The prospective cohort validated that the high-risk lesions (3p and/or 9p LOH) had a 22.6-fold increase in risk (P = 0.002) compared with low-risk lesions (3p and 9p retention). Addition of another 2 markers (loci on 4q/17p) further improved the risk prediction, with five-year progression rates of 3.1%, 16.3%, and 63.1% for the low-, intermediate-, and high-risk lesions, respectively. Compared with the low-risk group, intermediate- and high-risk groups had 11.6-fold and 52.1-fold increase in risk (P < 0.001). LOH profiles as risk predictors in the refined model were validated in the retrospective cohort. Multicovariate analysis with clinical features showed LOH models to be the most significant predictors of progression. LOH profiles can reliably differentiate progression risk for OPLs. Potential uses include increasing surveillance for patients with elevated risk, improving target intervention for high-risk patients while sparing a large number of low-risk patients from needless screening and treatment. Cancer Prev Res; 5(9); 1081–9. ©2012 AACR.
Data from Big Punches Come in Nanosizes for Chemoprevention
Authors: Sharma Dipali , Sukumar Saraswati
Published: March 2024

Abstract
Literature to support the chemopreventive potential of several bioactive molecules has been prolific and convincing, but the clinical development of these agents has been slow. Major hurdles for development of bioactive chemoprevention approaches include low potency, lack of reliable formulations with high bioavailability that are suitable for oral administration, and relevant preclinical primary prevention models that use meaningful doses that can be translated to humans. The paper presented in this issue (Grandhi and colleagues) is an important step forward in this direction. It shows the efficacy of an oral, low dose, solid-lipid nanoparticles encapsulated curcumin and aspirin combined with free sulforaphane for long-term chemoprevention of pancreatic cancer in a carcinogen-induced hamster model. Reproducing this benefit in multiple cancer models, accompanied by development of intermediate markers of response will allow rapid translation of these findings. It will constitute the first successful multipronged attack at key pathways known to initiate and promote carcinogenesis. Cancer Prev Res; 6(10); 1007–10. ©2013 AACR.
Data from Estrogen and Cytochrome P450 1B1 Contribute to Both Early- and Late-Stage Head and Neck Carcinogenesis
Authors: Shatalova Ekaterina G. , Klein-Szanto Andres J.P. , Devarajan Karthik , Cukierman Edna , Clapper Margie L.
Published: March 2024

Abstract
Squamous cell carcinoma of the head and neck (HNSCC) is the sixth most common type of cancer in the United States. The goal of this study was to evaluate the contribution of estrogens to the development of HNSCCs. Various cell lines derived from early- and late-stage head and neck lesions were used to characterize the expression of estrogen synthesis and metabolism genes, including cytochrome P450 (CYP) 1B1, examine the effect of estrogen on gene expression, and evaluate the role of CYP1B1 and/or estrogen in cell motility, proliferation, and apoptosis. Estrogen metabolism genes (CYP1B1, CYP1A1, catechol-o-methyltransferase, UDP-glucuronosyltransferase 1A1, and glutathione-S-transferase P1) and estrogen receptor (ER) β were expressed in cell lines derived from both premalignant (MSK-Leuk1) and malignant (HNSCC) lesions. Exposure to estrogen induced CYP1B1 2.3- to 3.6-fold relative to vehicle-treated controls (P = 0.0004) in MSK-Leuk1 cells but not in HNSCC cells. CYP1B1 knockdown by shRNA reduced the migration and proliferation of MSK-Leuk1 cells by 57% and 45%, respectively. Exposure of MSK-Leuk1 cells to estrogen inhibited apoptosis by 26%, whereas supplementation with the antiestrogen fulvestrant restored estrogen-dependent apoptosis. Representation of the estrogen pathway in human head and neck tissues from 128 patients was examined using tissue microarrays. The majority of the samples exhibited immunohistochemical staining for ERβ (91.9%), CYP1B1 (99.4%), and 17β-estradiol (88.4%). CYP1B1 and ERβ were elevated in HNSCCs relative to normal epithelium (P = 0.024 and 0.008, respectively). These data provide novel insight into the mechanisms underlying head and neck carcinogenesis and facilitate the identification of new targets for chemopreventive intervention. Cancer Prev Res; 4(1); 107–15. ©2011 AACR.
Data from Rapamycin Is a Potent Inhibitor of Skin Tumor Promotion by 12-O-Tetradecanoylphorbol-13-Acetate
Authors: Checkley L. Allyson , Rho Okkyung , Moore Tricia , Hursting Steve , DiGiovanni John
Published: March 2024

Abstract
Aberrant activation of phosphoinositide-3-kinase (PI3K)/Akt signaling has been implicated in the development and progression of multiple human cancers. During the process of skin tumor promotion induced by treatment with the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA), activation of epidermal Akt occurs as well as several downstream effectors of Akt, including the activation of mTORC1. Rapamycin, an established mTORC1 inhibitor, was used to further explore the role of mTORC1 signaling in epithelial carcinogenesis, specifically during the tumor promotion stage. Rapamycin blocked TPA-induced activation of mTORC1 as well as several downstream targets. In addition, TPA-induced epidermal hyperproliferation and hyperplasia were inhibited in a dose-dependent manner with topical rapamycin treatments. Immunohistochemical analyses of the skin from mice in this multiple treatment experiment revealed that rapamycin also significantly decreased the number of infiltrating macrophages, T cells, neutrophils, and mast cells seen in the dermis following TPA treatment. Using a two-stage skin carcinogenesis protocol with 7,12-dimethylbenz(a)anthracene (DMBA) as initiator and TPA as the promoter, rapamycin (5–200 nmol per mouse given topically 30 minutes prior to TPA) exerted a powerful antipromoting effect, reducing both tumor incidence and tumor multiplicity. Moreover, topical application of rapamycin to existing papillomas induced regression and/or inhibited further growth. Overall, the data indicate that rapamycin is a potent inhibitor of skin tumor promotion and suggest that signaling through mTORC1 contributes significantly to the process of skin tumor promotion. The data also suggest that blocking this pathway either alone or in combination with other agents targeting additional pathways may be an effective strategy for prevention of epithelial carcinogenesis. Cancer Prev Res; 4(7); 1011–20. ©2011 AACR.
Data from Acacetin Inhibits In Vitro and In Vivo Angiogenesis and Downregulates Stat Signaling and VEGF Expression
Authors: Bhat Tariq A. , Nambiar Dhanya , Tailor Dhanir , Pal Arttatrana , Agarwal Rajesh , Singh Rana P.
Published: March 2024

Abstract
Angiogenesis is an effective target in cancer control. The antiangiogenic efficacy and associated mechanisms of acacetin, a plant flavone, are poorly known. In the present study, acacetin inhibited growth and survival (up to 92%; P < 0.001), and capillary-like tube formation on Matrigel (up to 98%; P < 0.001) by human umbilical vein endothelial cells (HUVEC) in regular condition, as well as VEGF-induced and tumor cells conditioned medium–stimulated growth conditions. It caused retraction and disintegration of preformed capillary networks (up to 91%; P < 0.001). HUVEC migration and invasion were suppressed by 68% to 100% (P < 0.001). Acacetin inhibited Stat-1 (Tyr701) and Stat-3 (Tyr705) phosphorylation, and downregulated proangiogenic factors including VEGF, endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), matrix metalloproteinase-2 (MMP-2), and basic fibroblast growth factor (bFGF) in HUVEC. It also suppressed nuclear localization of pStat-3 (Tyr705). Acacetin strongly inhibited capillary sprouting and networking from rat aortic rings and fertilized chicken egg chorioallantoic membrane (CAM; ∼71%; P < 0.001). Furthermore, it suppressed angiogenesis in Matrigel plugs implanted in Swiss albino mice. Acacetin also inhibited tyrosine phosphorylation of Stat-1 and -3, and expression of VEGF in cancer cells. Overall, acacetin inhibits Stat signaling and suppresses angiogenesis in vitro, ex vivo, and in vivo, and therefore, it could be a potential agent to inhibit tumor angiogenesis and growth. Cancer Prev Res; 6(10); 1128–39. ©2013 AACR.
Data from Prostatic and Dietary Omega-3 Fatty Acids and Prostate Cancer Progression during Active Surveillance
Authors: Moreel Xavier , Allaire Janie , Léger Caroline , Caron André , Labonté Marie-Ève , Lamarche Benoît , Julien Pierre , Desmeules Patrice , Têtu Bernard , Fradet Vincent
Published: March 2024

Abstract
The association between omega-3 (ω-3) fatty acids and prostate cancer has been widely studied. However, little is known about the impact of prostate tissue fatty acid content on prostate cancer progression. We hypothesized that compared with the estimated dietary ω-3 fatty acids intake and the ω-3 fatty acids levels measured in red blood cells (RBC), the prostate tissue ω-3 fatty acid content is more strongly related to prostate cancer progression. We present the initial observations from baseline data of a phase II clinical trial conducted in a cohort of 48 untreated men affected with low-risk prostate cancer, managed under active surveillance. These men underwent a first repeat biopsy session within 6 months after the initial diagnosis of low-risk prostate cancer, at which time 29% of the men had progressed from a Gleason score of 6 to a Gleason score of 7. At the first repeat biopsy session, fatty acid levels were assessed with a food-frequency questionnaire, and determined in the RBC and in the prostate tissue biopsy. We found that eicosapentaenoic acid (EPA) was associated with a reduced risk of prostate cancer progression when measured directly in the prostate tissue. Thus, this initial interim study analysis suggests that prostate tissue ω-3 fatty acids, especially EPA, may be protective against prostate cancer progression in men with low-risk prostate cancer. Cancer Prev Res; 7(7); 766–76. ©2014 AACR.