bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Silencing of SmgGDS, a Novel mTORC1 Inducer That Binds to RHEBs, Inhibits Malignant Mesothelioma Cell Proliferation
Authors: Sato Tatsuhiro , Mukai Satomi , Ikeda Haruna , Mishiro-Sato Emi , Akao Ken , Kobayashi Toshiyuki , Hino Okio , Shimono Wataru , Shibagaki Yoshio , Hattori Seisuke , Sekido Yoshitaka
Published: March 2024

Abstract
Malignant mesothelioma (MM) is an aggressive tumor that typically develops after a long latency following asbestos exposure. Although mechanistic target of rapamycin complex 1 (mTORC1) activation enhances MM cell growth, the mTORC1 inhibitor everolimus has shown limited efficacy in clinical trials of MM patients. We explored the mechanism underlying mTORC1 activation in MM cells and its effects on cell proliferation and progression. Analysis of the expression profiles of 87 MMs from The Cancer Genome Atlas revealed that 40 samples (46%) displayed altered expression of RPTOR (mTORC1 component) and genes immediately upstream that activate mTORC1. Among them, we focused on RHEB and RHEBL1, which encode direct activators of mTORC1. Exogenous RHEBL1 expression enhanced MM cell growth, indicating that RHEB–mTORC1 signaling acts as a pro-oncogenic cascade. We investigated molecules that directly activate RHEBs, identifying SmgGDS as a novel RHEB-binding protein. SmgGDS knockdown reduced mTORC1 activation and inhibited the proliferation of MM cells with mTORC1 activation. Interestingly, SmgGDS displayed high binding affinity with inactive GDP-bound RHEBL1, and its knockdown reduced cytosolic RHEBL1 without affecting its activation. These findings suggest that SmgGDS retains GDP-bound RHEBs in the cytosol, whereas GTP-bound RHEBs are localized on intracellular membranes to promote mTORC1 activation. We revealed a novel role for SmgGDS in the RHEB–mTORC1 pathway and its potential as a therapeutic target in MM with aberrant mTORC1 activation.
Implications:
Our data showing that SmgGDS regulates RHEB localization to activate mTORC1 indicate that SmgGDS can be used as a new therapeutic target for MM exhibiting mTORC1 activation.
Data from Defects in Emerin–Nucleoskeleton Binding Disrupt Nuclear Structure and Promote Breast Cancer Cell Motility and Metastasis
Authors: Liddane Alexandra G. , McNamara Chelsea A. , Campbell Mallory C. , Mercier Isabelle , Holaska James M.
Published: March 2024

Abstract
Nuclear envelope proteins play an important role in regulating nuclear size and structure in cancer. Altered expression of nuclear lamins are found in many cancers and its expression is correlated with better clinical outcomes. The nucleus is the largest organelle in the cell with a diameter between 10 and 20 μm. Nuclear size significantly impacts cell migration. Nuclear structural changes are predicted to impact cancer metastasis by regulating cancer cell migration. Here we show emerin regulates nuclear structure in invasive breast cancer cells to impact cancer metastasis. Invasive breast cancer cells had 40% to 50% less emerin than control cells, which resulted in decreased nuclear size. Overexpression of GFP-emerin in invasive breast cancer cells rescued nuclear size and inhibited migration through 3.0 and 8.0 μm pores. Mutational analysis showed emerin binding to nucleoskeletal proteins was important for its regulation of nuclear structure, migration, and invasion. Importantly, emerin expression inhibited lung metastasis by 91% in orthotopic mouse models of breast cancer. Emerin nucleoskeleton-binding mutants failed to inhibit metastasis. These results support a model whereby emerin binding to the nucleoskeleton regulates nuclear structure to impact metastasis. In this model, emerin plays a central role in metastatic transformation, because decreased emerin expression during transformation causes the nuclear structural defects required for increased cell migration, intravasation, and extravasation.
Implications:
Modulating emerin expression and function represents new targets for therapeutic interventions of metastasis, because increased emerin expression rescued cancer metastasis.
Data from Selective ERBB2 and BCL2 Inhibition Is Synergistic for Mitochondrial-Mediated Apoptosis in MDS and AML Cells
Authors: Kam Angel Y.F. , Piryani Sadhna O. , Lee Chang-Lung , Rizzieri David A. , Spector Neil L. , Sarantopoulos Stefanie , Doan Phuong L.
Published: March 2024

Abstract
The ERBB2 proto-oncogene is associated with an aggressive phenotype in breast cancer. Its role in hematologic malignancies is incompletely defined, in part because ERBB2 is not readily detected on the surface of cancer cells. We demonstrate that truncated ERBB2, which lacks the extracellular domain, is overexpressed on primary CD34+ myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) cells compared with healthy hematopoietic cells. This overexpression of ERBB2 is associated with aberrant, oncogenic signaling with autophosphorylation of multiple tyrosine sites. Like in breast cancers, ERBB2 can exist as truncated isoforms p95ERBB2 and p110ERBB2 in MDS and AML. Neutralization of ERBB2 signaling with ERBB2 tyrosine kinase inhibitors (i.e., lapatinib, afatinib, and neratinib) increases apoptotic cell death and reduces human engraftment of MDS cells in mice at 21 weeks posttransplantation. Inhibition of ERBB2 modulates the expression of multiple pro- and anti-apoptotic mitochondrial proteins, including B-cell lymphoma 2 (BCL2). Dual blockade with ERBB2 and BCL2 inhibitors triggers additional reductions of BCL2 phosphorylation and myeloid cell leukemia-1 (MCL1) expression compared with single drug treatment. Dual therapy was synergistic at all tested doses, with a dose reduction index of up to 29 for lapatinib + venetoclax compared with venetoclax alone. Notably, these agents operated together and shifted cancer cells to a pro-apoptotic phenotype, resulting in increased mitochondrial cytochrome c release and activated caspase-3-mediated cell death.
Implications:
These findings warrant study of ERBB2 and BCL2 combination therapy in patients with MDS and AML.
Data from Genomic Alterations during the In Situ to Invasive Ductal Breast Carcinoma Transition Shaped by the Immune System
Authors: Trinh Anne , Gil Del Alcazar Carlos R. , Shukla Sachet A. , Chin Koei , Chang Young Hwan , Thibault Guillaume , Eng Jennifer , Jovanović Bojana , Aldaz C. Marcelo , Park So Yeon , Jeong Joon , Wu Catherine , Gray Joe , Polyak Kornelia
Published: March 2024

Abstract
The drivers of ductal carcinoma in situ (DCIS) to invasive ductal carcinoma (IDC) transition are poorly understood. Here, we conducted an integrated genomic, transcriptomic, and whole-slide image analysis to evaluate changes in copy-number profiles, mutational profiles, expression, neoantigen load, and topology in 6 cases of matched pure DCIS and recurrent IDC. We demonstrate through combined copy-number and mutational analysis that recurrent IDC can be genetically related to its pure DCIS despite long latency periods and therapeutic interventions. Immune “hot” and “cold” tumors can arise as early as DCIS and are subtype-specific. Topologic analysis showed a similar degree of pan-leukocyte-tumor mixing in both DCIS and IDC but differ when assessing specific immune subpopulations such as CD4 T cells and CD68 macrophages. Tumor-specific copy-number aberrations in MHC-I presentation machinery and losses in 3p, 4q, and 5p are associated with differences in immune signaling in estrogen receptor (ER)-negative IDC. Common oncogenic hotspot mutations in genes including TP53 and PIK3CA are predicted to be neoantigens yet are paradoxically conserved during the DCIS-to-IDC transition, and are associated with differences in immune signaling. We highlight both tumor and immune-specific changes in the transition of pure DCIS to IDC, including genetic changes in tumor cells that may have a role in modulating immune function and assist in immune escape, driving the transition to IDC.
Implications:
We demonstrate that the in situ to IDC evolutionary bottleneck is shaped by both tumor and immune cells.
Data from Exosomal Delivery of FTO Confers Gefitinib Resistance to Recipient Cells through ABCC10 Regulation in an m6A-dependent Manner
Authors: Xiao Peng , Liu Yu-kang , Han Wei , Hu Yan , Zhang Bo-you , Liu Wen-liang
Published: March 2024

Abstract
Gefitinib is suitable for the treatment of locally advanced or metastatic non–small cell lung cancer. However, the development of acquired resistance limits its long-term efficacy in regardless of significant clinical benefit to patients. Therefore, to elucidate the mechanism of gefitinib resistance in addition to target gene mutation may greatly increase its clinical efficacy. It was found first that N6-methyladenosine RNA demethylase FTO was significantly enriched in serum exosomes of gefitinib-resistant (GR) patients compared with that of gefitinib-sensitive (GS) patients through exosomal RNA sequencing. Meanwhile, the average m6A proportion in GR patients was significantly lower when compared with that in GS patients. Besides, GR cell–derived exosome internalization attenuated the total m6A abundance and gefitinib sensitivity of PC9 cells. Not only FTO knockdown enhanced the gefitinib sensitivity of GR cells but also FTO reduction in donor exosomes alleviated the acquired resistance of recipient PC9 cells. GR cell–derived exosomal-FTO promoted ABCC10 of recipient cells in a m6A-dependent manner. FTO/YTHDF2/ABCC10 axis played a role in intercellular transmission of GR cell–derived exosome-mediated gefitinib resistance both in vitro and in vivo. In general, this research showed that m6A modification was involved in the decrease of gefitinib sensitivity. GR cell–derived exosomes could decrease gefitinib sensitivity of recipient cells in exosomal delivery of FTO-dependent manner. FTO/YTHDF2/ABCC10 axis played a role in intercellular transmission of GR cell–derived exosome-mediated gefitinib resistance.
Implications:
Our results elucidated another potential molecular mechanism of gefitinib resistance in non–small cell lung cancer besides secondary EGFR mutations.
Data from AKT1 E17K Inhibits Cancer Cell Migration by Abrogating β-Catenin Signaling
Authors: Gao Sizhi Paul , Kiliti Amber J. , Zhang Kai , Vasani Naresh , Mao Ninghui , Jordan Emmet , Wise Hannah C. , Shrestha Bhattarai Tripti , Hu Wenhuo , Dorso Madeline , Rodrigues James A. , Kim Kwanghee , Hanrahan Aphrothiti J. , Razavi Pedram , Carver Brett , Chandarlapaty Sarat , Reis-Filho Jorge S. , Taylor Barry S. , Solit David B.
Published: March 2024

Abstract
Mutational activation of the PI3K/AKT pathway is among the most common pro-oncogenic events in human cancers. The clinical utility of PI3K and AKT inhibitors has, however, been modest to date. Here, we used CRISPR-mediated gene editing to study the biological consequences of AKT1 E17K mutation by developing an AKT1 E17K–mutant isogenic system in a TP53-null background. AKT1 E17K expression under the control of its endogenous promoter enhanced cell growth and colony formation, but had a paradoxical inhibitory effect on cell migration and invasion. The mechanistic basis by which activated AKT1 inhibited cell migration and invasion was increased E-cadherin expression mediated by suppression of ZEB1 transcription via altered β-catenin subcellular localization. This phenotypic effect was AKT1-specific, as AKT2 activation had the opposite effect, a reduction in E-cadherin expression. Consistent with the opposing effects of AKT1 and AKT2 activation on E-cadherin expression, a pro-migratory effect of AKT1 activation was not observed in breast cancer cells with PTEN loss or expression of an activating PIK3CA mutation, alterations which induce the activation of both AKT isoforms. The results suggest that the use of AKT inhibitors in patients with breast cancer could paradoxically accelerate metastatic progression in some genetic contexts and may explain the frequent coselection for CDH1 mutations in AKT1-mutated breast tumors.
Implications:
AKT1 E17K mutation in breast cancer impairs migration/invasiveness via sequestration of β-catenin to the cell membrane leading to decreased ZEB1 transcription, resulting in increased E-cadherin expression and a reversal of epithelial–mesenchymal transition.
Data from Neoadjuvant Chemotherapy Induces IL34 Signaling and Promotes Chemoresistance via Tumor-Associated Macrophage Polarization in Esophageal Squamous Cell Carcinoma
Authors: Nakajima Shotaro , Mimura Kosaku , Saito Katsuharu , Thar Min Aung Kyi , Endo Eisei , Yamada Leo , Kase Koji , Yamauchi Naoto , Matsumoto Takuro , Nakano Hiroshi , Kanke Yasuyuki , Okayama Hirokazu , Saito Motonobu , Neupane Prajwal , Saze Zenichiro , Watanabe Yohei , Hanayama Hiroyuki , Hayase Suguru , Kaneta Akinao , Momma Tomoyuki , Ohki Shinji , Ohira Hiromasa , Kono Koji
Published: March 2024

Abstract
The tumor microenvironment (TME) plays a key role in the efficacy of neoadjuvant chemotherapy (NAC) in solid tumors including esophageal squamous cell carcinoma (ESCC). However, the TME profile of ESCC treated with NAC is not fully understood. In this study, we investigated the effect of NAC on the TME especially tumor-associated macrophages (TAM), the important immunosuppressive components of the TME, in ESCC. We quantified the expression of CD163, a crucial marker of TAM, in pretherapeutic biopsy and surgically resected ESCC specimens from patients who received NAC (n = 33) or did not receive NAC (n = 12). We found that NAC dramatically increased the expression of CD163 on TAMs in ESCC. Colony-stimulating factor 1 (CSF-1) and IL34 are crucial cytokines that recruit monocytes into tumor sites and differentiate them into TAMs. Interestingly, NAC significantly upregulated the expression of IL34 but not CSF-1 on tumor cells, and the frequencies of CD163+ TAMs were significantly correlated with IL34 expression in ESCC after NAC. The expression of IL34 in NAC-nonresponsive patients was significantly higher than that in NAC-responsive patients, and patients with IL34-high ESCC exhibited worse prognosis as compared with patients with IL34-low ESCC. We also demonstrated that 5-fluorouracil (5-FU)/cisplatin preferentially increased mRNA expression of IL34 on human ESCC cell lines. Human peripheral blood monocytes co-cultured with ESCC cells treated with 5-FU/cisplatin increased the expression of CD163, which was attenuated by the treatment with CSF-1R inhibitors. These data suggest that IL34 expression by NAC shifts the TME toward CD163+ TAM-rich immunosuppressive and chemo-insensitive microenvironment in ESCC.
Implications:
The blockade of IL34 signaling may offer a novel therapeutic strategy against chemoresistance in ESCC by inhibiting M2-TAM polarization.
Data from EGR1 Addiction in Diffuse Large B-cell Lymphoma
Authors: Kimpara Shuichi , Lu Li , Hoang Nguyet M. , Zhu Fen , Bates Paul D. , Daenthanasanmak Anusara , Zhang Shanxiang , Yang David T. , Kelm Amanda , Liu Yunxia , Li Yangguang , Rosiejka Alexander , Kondapelli Apoorv , Bebel Samantha , Chen Madelyn , Waldmann Thomas A. , Capitini Christian M. , Rui Lixin
Published: March 2024

Abstract
Early growth response gene (EGR1) is a transcription factor known to be a downstream effector of B-cell receptor signaling and Janus kinase 1 (JAK1) signaling in diffuse large B-cell lymphoma (DLBCL). While EGR1 is characterized as a tumor suppressor in leukemia and multiple myeloma, the role of EGR1 in lymphoma is unknown. Here we demonstrate that EGR1 is a potential oncogene that promotes cell proliferation in DLBCL. IHC analysis revealed that EGR1 expression is elevated in DLBCL compared with normal lymphoid tissues and the level of EGR1 expression is higher in activated B cell–like subtype (ABC) than germinal center B cell–like subtype (GCB). EGR1 expression is required for the survival and proliferation of DLBCL cells. Genomic analyses demonstrated that EGR1 upregulates expression of MYC and E2F pathway genes through the CBP/p300/H3K27ac/BRD4 axis while repressing expression of the type I IFN pathway genes by interaction with the corepressor NAB2. Genetic and pharmacologic inhibition of EGR1 synergizes with the BRD4 inhibitor JQ1 or the type I IFN inducer lenalidomide in growth inhibition of ABC DLBCL both in cell cultures and xenograft mouse models. Therefore, targeting oncogenic EGR1 signaling represents a potential new targeted therapeutic strategy in DLBCL, especially for the more aggressive ABC DLBCL.
Implications:
The study characterizes EGR1 as a potential oncogene that promotes cell proliferation and defines EGR1 as a new molecular target in DLBCL, the most common non-Hodgkin lymphoma.
Data from ILT3 (LILRB4) Promotes the Immunosuppressive Function of Tumor-Educated Human Monocytic Myeloid-Derived Suppressor Cells
Authors: Singh Latika , Muise Eric S. , Bhattacharya Anannya , Grein Jeff , Javaid Sarah , Stivers Peter , Zhang Jun , Qu Yujie , Joyce-Shaikh Barbara , Loboda Andrey , Zhang Chunsheng , Meehl Michael , Chiang Derek Y. , Ranganath Sheila H. , Rosenzweig Michael , Brandish Philip E.
Published: March 2024

Abstract
Myeloid-derived suppressor cells (MDSC) are immature myeloid cells that accumulate in the tumor microenvironment (TME). MDSCs have been shown to dampen antitumor immune responses and promote tumor growth; however, the mechanisms of MDSC induction and their role in promoting immune suppression in cancer remain poorly understood. Here, we characterized the phenotype and function of monocytic MDSCs (M-MDSC) generated by coculture of human peripheral blood mononuclear cells with SK-MEL-5 cancer cells in vitro. We selected the SK-MEL-5 human melanoma cell line to generate M-MDSCs because these cells form subcutaneous tumors rich in myeloid cells in humanized mice. M-MDSCs generated via SK-MEL-5 coculture expressed low levels of human leukocyte antigen (HLA)-DR, high levels of CD33 and CD11b, and suppressed both CD8+ T-cell proliferation and IFNγ secretion. M-MDSCs also expressed higher levels of immunoglobulin-like transcript 3 (ILT3, also known as LILRB4) and immunoglobulin-like transcript 4 (ILT4, also known as LILRB2) on the cell surface compared with monocytes. Therefore, we investigated how ILT3 targeting could modulate M-MDSC cell function. Treatment with an anti-ILT3 antibody impaired the acquisition of the M-MDSC suppressor phenotype and reduced the capacity of M-MDSCs to cause T-cell suppression. Finally, in combination with anti-programmed cell death protein 1 (PD1), ILT3 blockade enhanced T-cell activation as assessed by IFNγ secretion.
Implications:
These results suggest that ILT3 expressed on M-MDSCs has a role in inducing immunosuppression in cancer and that antagonism of ILT3 may be useful to reverse the immunosuppressive function of M-MDSCs and enhance the efficacy of immune checkpoint inhibitors.
Data from Genomic Landscape of Primary and Recurrent Anal Squamous Cell Carcinomas in Relation to HPV Integration, Copy-Number Variation, and DNA Damage Response Genes
Authors: Aldersley Jordan , Lorenz David R. , Mouw Kent W. , D'Andrea Alan D. , Gabuzda Dana
Published: March 2024

Abstract
The incidence of anal squamous cell carcinoma (ASCC) has been increasing, particularly in populations with HIV. Human papillomavirus (HPV) is the causal factor in 85% to 90% of ASCCs, but few studies evaluated HPV genotypes and integrations in relation to genomic alterations in ASCC. Using whole-exome sequence data for primary (n = 56) and recurrent (n = 31) ASCC from 72 patients, we detected HPV DNA in 87.5% of ASCC, of which HPV-16, HPV-18, and HPV-6 were detected in 56%, 22%, and 33% of HIV-positive (n = 9) compared with 83%, 3.2%, and 1.6% of HIV-negative cases (n = 63), respectively. Recurrent copy-number variations (CNV) involving genes with documented roles in cancer included amplification of PI3KCA and deletion of APC in primary and recurrent tumors; amplifications of CCND1, MYC, and NOTCH1 and deletions of BRCA2 and RB1 in primary tumors; and deletions of ATR, FANCD2, and FHIT in recurrent tumors. DNA damage response genes were enriched among recurrently deleted genes in recurrent ASCCs (P = 0.001). HPV integrations were detected in 29 of 76 (38%) ASCCs and were more frequent in stage III–IV versus stage I–II tumors. HPV integrations were detected near MYC and CCND1 amplifications and recurrent targets included NFI and MUC genes. These results suggest HPV genotypes in ASCC differ by HIV status, HPV integration is associated with ASCC progression, and DNA damage response genes are commonly disrupted in recurrent ASCCs.
Implications:
These data provide the largest whole-exome sequencing study of the ASCC genomic landscape to date and identify HPV genotypes, integrations, and recurrent CNVs in primary or recurrent ASCCs.
Data from GAS6/AXL Inhibition Enhances Ovarian Cancer Sensitivity to Chemotherapy and PARP Inhibition through Increased DNA Damage and Enhanced Replication Stress
Authors: Mullen Mary M. , Lomonosova Elena , Toboni Michael D. , Oplt Alyssa , Cybulla Emily , Blachut Barbara , Zhao Peinan , Noia Hollie , Wilke Daniel , Rankin Erinn B. , Kuroki Lindsay M. , Hagemann Andrea R. , Hagemann Ian S. , McCourt Carolyn K. , Thaker Premal H. , Mutch David G. , Powell Matthew A. , Mosammaparast Nima , Vindigni Alessandro , Fuh Katherine C.
Published: March 2024

Abstract
Over 80% of women with high-grade serous ovarian cancer (HGSOC) develop tumor resistance to chemotherapy and die of their disease. There are currently no FDA-approved agents to improve sensitivity to first-line platinum- and taxane-based chemotherapy or to PARP inhibitors. Here, we tested the hypothesis that expression of growth arrest–specific 6 (GAS6), the ligand of receptor tyrosine kinase AXL, is associated with chemotherapy response and that sequestration of GAS6 with AVB-S6–500 (AVB-500) could improve tumor response to chemotherapy and PARP inhibitors. We found that GAS6 levels in patient tumor and serum samples collected before chemotherapy correlated with ovarian cancer chemoresponse and patient survival. Compared with chemotherapy alone, AVB-500 plus carboplatin and/or paclitaxel led to decreased ovarian cancer-cell survival in vitro and tumor burden in vivo. Cells treated with AVB-500 plus carboplatin had more DNA damage, slower DNA replication fork progression, and fewer RAD51 foci than cells treated with carboplatin alone, indicating AVB-500 impaired homologous recombination (HR). Finally, treatment with the PARP inhibitor olaparib plus AVB-500 led to decreased ovarian cancer-cell survival in vitro and less tumor burden in vivo. Importantly, this effect was seen in HR-proficient and HR-deficient ovarian cancer cells. Collectively, our findings suggest that GAS6 levels could be used to predict response to carboplatin and AVB-500 could be used to treat platinum-resistant, HR-proficient HGSOC.
Implications:
GAS6/AXL is a novel target to sensitize ovarian cancers to carboplatin and olaparib. Additionally, GAS6 levels can be associated with response to carboplatin treatment.
Data from EML4-ALK Variant 3 Promotes Mitotic Errors and Spindle Assembly Checkpoint Deficiency Leading to Increased Microtubule Poison Sensitivity
Authors: Lucken Kellie , O'Regan Laura , Choi Jene , Sampson Josephina , Pashley Sarah L. , Bayliss Richard , Khan Sam , Fry Andrew M.
Published: March 2024

Abstract
EML4-ALK is an oncogenic fusion protein present in approximately 5% of non–small cell lung cancers (NSCLC). Alternative breakpoints in the gene encoding EML4 result in distinct variants that are linked to markedly different patient outcomes. Patients with EML4-ALK variant 3 (V3) respond poorly to ALK inhibitors and have lower survival rates compared with patients with other common variants, such as V1. Here, we use isogenic Beas-2B bronchial epithelial cell lines expressing EML4-ALK V1 or V3, as well as ALK-positive NSCLC patient cells that express V1 (H3122 cells) or V3 (H2228 cells), to show that EML4-ALK V3 but not V1 leads to hyperstabilized K-fibers in mitosis, as well as errors in chromosome congression and segregation. This is consistent with our observation that EML4-ALK V3 but not V1 localizes to spindle microtubules and that wild-type EML4 is a microtubule stabilizing protein. In addition, cells expressing EML4-ALK V3 exhibit loss of spindle assembly checkpoint control that is at least in part dependent on ALK catalytic activity. Finally, we demonstrate that cells expressing EML4-ALK V3 have increased sensitivity to microtubule poisons that interfere with mitotic spindle assembly, whereas combination treatment with paclitaxel and clinically approved ALK inhibitors leads to a synergistic response in terms of reduced survival of H2228 cells.
Implications:
This study suggests that combining the microtubule poison, paclitaxel, with targeted ALK inhibitors may provide an effective new treatment option for patients with NSCLC with tumors that express the EML4-ALK V3 oncogenic fusion.
Data from Subtype and Site Specific–Induced Metabolic Vulnerabilities in Prostate Cancer
Authors: Mossa Federica , Robesti Daniele , Sumankalai Ramachandran , Corey Eva , Titus Mark , Kang Yuqi , Zhang Jianhua , Briganti Alberto , Montorsi Francesco , Vellano Christopher P. , Marszalek Joseph R. , Frigo Daniel E. , Logothetis Christopher J. , Gujral Taranjit S. , Dondossola Eleonora
Published: March 2024

Abstract
Aberrant metabolic functions play a crucial role in prostate cancer progression and lethality. Currently, limited knowledge is available on subtype-specific metabolic features and their implications for treatment. We therefore investigated the metabolic determinants of the two major subtypes of castration-resistant prostate cancer [androgen receptor–expressing prostate cancer (ARPC) and aggressive variant prostate cancer (AVPC)]. Transcriptomic analyses revealed enrichment of gene sets involved in oxidative phosphorylation (OXPHOS) in ARPC tumor samples compared with AVPC. Unbiased screening of metabolic signaling pathways in patient-derived xenograft models by proteomic analyses further supported an enrichment of OXPHOS in ARPC compared with AVPC, and a skewing toward glycolysis by AVPC. In vitro, ARPC C4–2B cells depended on aerobic respiration, while AVPC PC3 cells relied more heavily on glycolysis, as further confirmed by pharmacologic interference using IACS-10759, a clinical-grade inhibitor of OXPHOS. In vivo studies confirmed IACS-10759′s inhibitory effects in subcutaneous and bone-localized C4–2B tumors, and no effect in subcutaneous PC3 tumors. Unexpectedly, IACS-10759 inhibited PC3 tumor growth in bone, indicating microenvironment-induced metabolic reprogramming. These results suggest that castration-resistant ARPC and AVPC exhibit different metabolic dependencies, which can further undergo metabolic reprogramming in bone.
Implications:
These vulnerabilities may be exploited with mechanistically novel treatments, such as those targeting OXPHOS alone or possibly in combination with existing therapies. In addition, our findings underscore the impact of the tumor microenvironment in reprogramming prostate cancer metabolism.
Data from The C-terminus of Gain-of-Function Mutant p53 R273H Is Required for Association with PARP1 and Poly-ADP-Ribose
Authors: Lundine Devon , Annor George K. , Chavez Valery , Maimos Styliana , Syed Zafar , Jiang Shuhong , Ellison Viola , Bargonetti Jill
Published: March 2024

Abstract
The TP53 gene is mutated in 80% of triple-negative breast cancers. Cells that harbor the hot-spot p53 gene mutation R273H produce an oncogenic mutant p53 (mtp53) that enhances cell proliferative and metastatic properties. The enhanced activities of mtp53 are collectively referred to as gain-of-function (GOF), and may include transcription-independent chromatin-based activities shared with wild-type p53 (wtp53) such as association with replicating DNA and DNA replication associated proteins like PARP1. However, how mtp53 upregulates cell proliferation is not well understood. wtp53 interacts with PARP1 using a portion of its C-terminus. The wtp53 oligomerization and far C-terminal domain (CTD) located within the C-terminus constitute putative GOF-associated domains, because mtp53 R273H expressing breast cancer cells lacking both domains manifest slow proliferation phenotypes. We addressed if the C-terminal region of mtp53 R273H is important for chromatin interaction and breast cancer cell proliferation using CRISPR-Cas9 mutated MDA-MB-468 cells endogenously expressing mtp53 R273H C-terminal deleted isoforms (R273HΔ381–388 and R273HΔ347–393). The mtp53 R273HΔ347–393 lacks the CTD and a portion of the oligomerization domain. We observed that cells harboring mtp53 R273HΔ347–393 (compared with mtp53 R273H full-length) manifest a significant reduction in chromatin, PARP1, poly-ADP-ribose (PAR), and replicating DNA binding. These cells also exhibited impaired response to hydroxyurea replicative stress, decreased sensitivity to the PARP-trapping drug combination temozolomide–talazoparib, and increased phosphorylated 53BP1 foci, suggesting reduced Okazaki fragment processing.
Implications:
The C-terminal region of mtp53 confers GOF activity that mediates mtp53–PARP1 and PAR interactions assisting DNA replication, thus implicating new biomarkers for PARP inhibitor therapy.
Data from Small-Molecule NSC59984 Induces Mutant p53 Degradation through a ROS-ERK2-MDM2 Axis in Cancer Cells
Authors: Zhang Shengliang , Zhou Lanlan , El-Deiry Wafik S.
Published: March 2024

Abstract
Increased reactive oxygen species (ROS) and hyperstabilized mutant p53 are common in cancer. Hyperstabilized mutant p53 contributes to its gain of function (GOF) which confers resistance to chemotherapy and radiotherapy. Targeting mutant p53 degradation is a promising cancer therapeutic strategy. We used a small-molecule NSC59984 to explore elimination of mutant p53 in cancer cells, and identified an inducible ROS-ERK2-MDM2 axis as a vulnerability for induction of mutant p53 degradation in cancer cells. NSC59984 treatment promotes a constitutive phosphorylation of ERK2 via ROS in cancer cells. The NSC59984-sustained ERK2 activation is required for MDM2 phosphorylation at serine-166. NSC59984 enhances phosphorylated-MDM2 binding to mutant p53, which leads to mutant p53 ubiquitination and degradation. High cellular ROS increases the efficacy of NSC59984 targeting mutant p53 degradation and antitumor effects. Our data suggest that mutant p53 stabilization has a vulnerability under high ROS cellular conditions, which can be exploited by compounds to target mutant p53 protein degradation through the activation of a ROS-ERK2-MDM2 axis in cancer cells.
Implications:
An inducible ROS-ERK2-MDM2 axis exposes a vulnerability in mutant p53 stabilization and can be exploited by small-molecule compounds to induce mutant p53 degradation for cancer therapy.
Data from mTOR Inhibition and T-DM1 in HER2-Positive Breast Cancer
Authors: Casadevall David , Hernández-Prat Anna , García-Alonso Sara , Arpí-Llucià Oriol , Menéndez Silvia , Qin Mengjuan , Guardia Cristina , Morancho Beatriz , Sánchez-Martín Francisco Javier , Zazo Sandra , Gavilán Elena , Sabbaghi Mohammad A. , Eroles Pilar , Cejalvo Juan Miguel , Lluch Ana , Rojo Federico , Pandiella Atanasio , Rovira Ana , Albanell Joan
Published: March 2024

Abstract
In patients with trastuzumab-resistant HER2-positive breast cancer, the combination of everolimus (mTORC1 inhibitor) with trastuzumab failed to show a clinically significant benefit. However, the combination of mTOR inhibition and the antibody–drug conjugate (ADC) trastuzumab-emtansine (T-DM1) remains unexplored. We tested T-DM1 plus everolimus in a broad panel of HER2-positive breast cancer cell lines. The combination was superior to T-DM1 alone in four cell lines (HCC1954, SKBR3, EFM192A, and MDA-MB-36) and in two cultures from primary tumor cells derived from HER2-positive patient-derived xenografts (PDX), but not in BT474 cells. In the trastuzumab-resistant HCC1954 cell line, we characterized the effects of the combination using TAK-228 (mTORC1 and -2 inhibitor) and knockdown of the different mTOR complex components. T-DM1 did not affect mTOR downstream signaling nor induct autophagy. Importantly, mTOR inhibition increased intracellular T-DM1 levels, leading to increased lysosomal accumulation of the compound. The increased efficacy of mTOR inhibition plus T-DM1 was abrogated by lysosome inhibitors (chloroquine and bafilomycin A1). Our experiments suggest that BT474 are less sensitive to T-DM1 due to lack of optimal lysosomal processing and intrinsic resistance to the DM1 moiety. Finally, we performed several in vivo experiments that corroborated the superior activity of T-DM1 and everolimus in HCC1954 and PDX-derived mouse models. In summary, everolimus in combination with T-DM1 showed strong antitumor effects in HER2-positive breast cancer, both in vitro and in vivo. This effect might be related, at least partially, to mTOR-dependent lysosomal processing of T-DM1, a finding that might apply to other ADCs that require lysosomal processing.
Implications:
Inhibition of mTOR increases the antitumor activity of T-DM1, supporting that the combination of mTOR inhibitors and antibody–drug conjugates warrants clinical evaluation in patients with HER2-positive breast cancer.
Data from Pan-Cancer HLA Gene-Mediated Tumor Immunogenicity and Immune Evasion
Authors: Gong Xutong , Karchin Rachel
Published: March 2024

Abstract
Human leukocyte antigen (HLA) expression contributes to the activation of antitumor immunity through interactions with T-cell receptors. Pan-cancer HLA-mediated immunogenicity and immunoediting mechanisms have not been systematically studied previously. In a retrospective analysis of 33 tumor types from the Cancer Genome Atlas (TCGA), we characterized the differential expression of HLA class I and class II genes across various oncogenic pathways and immune subtypes. While HLA I genes were upregulated in all immunogenically hot tumors, HLA II genes were upregulated in an inflammatory immune subtype associated with best prognosis and were systematically downregulated in specific oncogenic pathways. A subset of immunogenically hot tumors which upregulated HLA class I but not class II genes exploited HLA-mediated escape strategies. Furthermore, with a machine learning model, we demonstrated that HLA gene expression data can be used to predict the immune subtypes of patients receiving immune checkpoint blockade and stratify patient survival. Interestingly, tumors with the highest immune infiltration did not have the best prognosis but showed significantly higher immune exhaustion.
Implications:
Taken together, we highlight the prognostic potential of HLA genes in immunotherapies and suggest that higher tumor immunogenicity mediated by HLA expression may sometimes lead to tumor escape under strong selective pressure.
Data from Stromal p53 Regulates Breast Cancer Development, the Immune Landscape, and Survival in an Oncogene-Specific Manner
Authors: Wu Jinghai , Liu Xin , Reeser Julie A. Wallace , Trimboli Anthony J. , Pécot Thierry , Sizemore Gina M. , Naidu Shan K. , Fernandez Soledad A. , Yu Lianbo , Hallett Michael , Park Morag , Leone Gustavo W. , Hildreth Blake E. , Ostrowski Michael C.
Published: March 2024

Abstract
Coevolution of tumor cells and adjacent stromal elements is a key feature during tumor progression; however, the precise regulatory mechanisms during this process remain unknown. Here, we show stromal p53 loss enhances oncogenic KrasG12D, but not ErbB2, driven tumorigenesis in murine mammary epithelia. Stroma-specific p53 deletion increases both epithelial and fibroblast proliferation in mammary glands bearing the KrasG12D oncogene in epithelia, while concurrently increasing DNA damage and/or DNA replication stress and decreasing apoptosis in the tumor cells proper. Normal epithelia was not affected by stromal p53 deletion. Tumors with p53-null stroma had a significant decrease in total, cytotoxic, and regulatory T cells; however, there was a significant increase in myeloid-derived suppressor cells, total macrophages, and M2-polarized tumor-associated macrophages, with no impact on angiogenesis or connective tissue deposition. Stroma-specific p53 deletion reprogrammed gene expression in both fibroblasts and adjacent epithelium, with p53 targets and chemokine receptors/chemokine signaling pathways in fibroblasts and DNA replication, DNA damage repair, and apoptosis in epithelia being the most significantly impacted biological processes. A gene cluster in p53-deficient mouse fibroblasts was negatively associated with patient survival when compared with two independent datasets. In summary, stroma-specific p53 loss promotes mammary tumorigenesis in an oncogene-specific manner, influences the tumor immune landscape, and ultimately impacts patient survival.
Implications:
Expression of the p53 tumor suppressor in breast cancer tumor stroma regulates tumorigenesis in an oncogene-specific manner, influences the tumor immune landscape, and ultimately impacts patient survival.
Data from TRAF4 Inhibits Bladder Cancer Progression by Promoting BMP/SMAD Signaling
Authors: Iyengar Prasanna Vasudevan , Marvin Dieuwke Louise , Lama Dilraj , Tan Tuan Zea , Suriyamurthy Sudha , Xie Feng , van Dinther Maarten , Mei Hailiang , Verma Chandra Shekhar , Zhang Long , Ritsma Laila , ten Dijke Peter
Published: March 2024

Abstract
Patients with bladder cancer often have a poor prognosis due to the highly invasive and metastatic characteristics of bladder cancer cells. Epithelial-to-mesenchymal transition (EMT) has been causally linked to bladder cancer invasion. The E3 ubiquitin ligase, tumor necrosis factor receptor–associated factor 4 (TRAF4) has been implicated as a tumor promoter in a wide range of cancers. In contrast, here we show that low TRAF4 expression is associated with poor overall survival in patients with bladder cancer. We show that the TRAF4 gene is epigenetically silenced and that ERK mediates TRAF4 phosphorylation, resulting in lower TRAF4 protein levels in bladder cancer cells. In addition, we demonstrate that TRAF4 is inversely correlated with an EMT gene signature/protein marker expression. Functionally, by manipulating TRAF4 expression, we show that TRAF4 regulates EMT genes and epithelial and invasive properties in bladder cancer cells. Transcriptomic analysis of dysregulated TRAF4 expression in bladder cancer cell lines revealed that high TRAF4 expression enhances the bone morphogenetic protein (BMP)/SMAD and inhibits the NF-κB signaling pathway. Mechanistically, we show that TRAF4 targets the E3 ubiquitin ligase SMURF1, a negative regulator of BMP/SMAD signaling, for proteasomal degradation in bladder cancer cells. This was corroborated in patient samples where TRAF4 positively correlates with phospho-SMAD1/5, and negatively correlates with phospho-NFκb-p65. Lastly, we show that genetic and pharmacologic inhibition of SMURF1 inhibits the migration of aggressive mesenchymal bladder cancer cells.
Implications:
Our findings identify E3 ubiquitin ligase TRAF4 as a potential therapeutic target or biomarker for bladder cancer progression.
Data from The E3 Ligase MIB1 Promotes Proteasomal Degradation of NRF2 and Sensitizes Lung Cancer Cells to Ferroptosis
Authors: Wang Haiyun , Huang Qiuling , Xia Jianhong , Cheng Shan , Pei Duanqing , Zhang Xiaofei , Shu Xiaodong
Published: March 2024

Abstract
Dysregulation of Notch signaling has been implicated in cellular transformation and tumorigenesis in a variety of cancers while potential roles of MIB1, an E3 ubiquitin ligase required for efficient Notch activation, remains to be investigated. We analyzed MIB1 expression levels in tumor samples and performed gain-of-function and loss-of-function studies in cell lines to investigate potential roles of MIB1 in epithelial-to-mesenchymal transition (EMT), cell migration, and cell survival. We found that overexpression of MIB1 is detected in a subset of lung squamous carcinoma and adenocarcinoma samples and negative correlation is observed between MIB1 expression and overall patient survival. Ectopic expression of MIB1 in A549 cells induces EMT and stimulates cell migration via a Notch-dependent pathway. Meanwhile, MIB1 stimulates the degradation of nuclear factor erythroid 2-related factor 2 (NRF2) in a Notch-independent manner and disrupts the antioxidant capacity of cells, rendering them more sensitive to inducers of ferroptosis. On the other hand, MIB1 knockout induces accumulation of NRF2 and resistance to ferroptosis. Collectively, these results indicate that MIB1 may function as a positive regulator of ferroptosis through targeted degradation of the master antioxidant transcription factor NRF2.
Implications:
This study identifies a MIB1-induced proteasomal degradation pathway for NRF2 and reveals elevated ferroptosis sensitivity in MIB1-overexpressing cells which may provide novel insights into the treatment of MIB1-overexpressing cancers.
Data from PARK2 Regulates eIF4B-Driven Lymphomagenesis
Authors: Kapadia Bandish B. , Roychowdhury Anirban , Kayastha Forum , Nanaji Nahid , Gartenhaus Ronald B.
Published: March 2024

Abstract
Patients with high-risk diffuse large B-cell lymphoma have poor outcomes following first-line cyclophosphamide, doxorubicin, vincristine, prednisone, and rituximab (R-CHOP); thus, treatment of this fatal disease remains an area of unmet medical need and requires identification of novel therapeutic approaches. Dysregulation of protein translation initiation has emerged as a common downstream node in several malignancies, including lymphoma. Ubiquitination, a prominent posttranslational modification associated with substrate degradation, has recently been shown to be a key modulator of nascent peptide synthesis by limiting several translational initiation factors. While a few deubiquitinases have been identified, the E3 ligase responsible for the critical ubiquitination of these translational initiation factors is still unknown. In this study, using complementary cellular models along with clinical readouts, we establish that PARK2 ubiquitinates eIF4B and consequently regulates overall protein translational activity. The formation of this interaction depends on upstream signaling, which is negatively regulated at the protein level of PARK2. Through biochemical, mutational, and genetic studies, we identified PARK2 as a mTORC1 substrate. mTORC1 phosphorylates PARK2 at Ser127, which blocks its cellular ubiquitination activity, thereby hindering its tumor suppressor effect on eIF4B's stability. This resultant increase of eIF4B protein level helps drive enhanced overall protein translation. These data support a novel paradigm in which PARK2-generated eIF4B ubiquitination serves as an anti-oncogenic intracellular inhibitor of protein translation, attenuated by mTORC1 signaling.
Implications:
Our data implicate the FASN/mTOR-PARK2-eIF4B axis as a critical driver of enhanced oncogene expression contributing to lymphomagenesis.
Data from LncRNA A2M-AS1 Promotes Ferroptosis in Pancreatic Cancer via Interacting With PCBP3
Authors: Qiu Xin , Shi Qiuyue , Zhang Xianglian , Shi Xiaoyan , Jiang Haixing , Qin Shanyu
Published: March 2024

Abstract
Ferroptosis is a newly-discovered cell death mechanism involved in the progression of various tumors, the role of noncoding RNAs (ncRNAs) in it was relatively less explored. This study identified the low levels of a recently studied long noncoding RNA (lncRNA), A2M-AS1, in pancreatic cancer and suggested its positive correlation with the overall survival time of patients with pancreatic cancer. A2M-AS1 was mainly localized in the cytoplasm, inhibiting the cellular proliferation, migration, and invasion as well as the tumor growth of the pancreatic cancer cells. Moreover, the Erastin-induced ferroptosis increased the expression levels of A2M-AS1. The overexpression of A2M-AS1 promoted ferroptosis in the pancreatic cancer, which was inhibited by the silencing of A2M-AS1. Mechanically, A2M-AS1 could directly interact with the poly (rC) binding protein 3 (PCBP3), which plays an important role in the process of iron metabolism, thereby promoting the ferroptosis in pancreatic cancer. In addition, the A2M-AS1/PCBP3 axis could facilitate the p38 activation and inhibit the phosphorylation of the AKT–mTOR signaling pathway; all these participate in regulating ferroptosis. In conclusion, the regulation of ferroptosis by targeting the A2M-AS1/PCBP3 axis might provide a novel target for the treatment of pancreatic cancer in the future.
Implications:
A2M-AS1 might be a potential novel therapeutic target for patients with pancreatic cancer in the future.
Data from A Hyaluronan and Proteoglycan Link Protein 1 Matrikine: Role of Matrix Metalloproteinase 2 in Multiple Myeloma NF-κB Activation and Drug Resistance
Authors: Mark Christina , Warrick Jay , Callander Natalie S. , Hematti Peiman , Miyamoto Shigeki
Published: March 2024

Abstract
The NF-κB signaling pathway plays key roles in inflammation and the pathogenesis of many solid and hematologic malignancies, including multiple myeloma, a malignancy of the plasma cells. While proteasome inhibitors, such as bortezomib, employed in multiple myeloma treatments may inhibit NF-κB signaling pathways, multiple myeloma cells often become drug resistant in part due to non–cell autonomous mechanism(s) from the multiple myeloma tumor microenvironment. We previously found that fragments of, but not full-length, hyaluronan and proteoglycan link protein 1 (HAPLN1), produced by multiple myeloma bone marrow stromal cells (BMSC), activate an atypical bortezomib-resistant NF-κB pathway in multiple myeloma cells. In our current study, we found that multiple myeloma cells promote HAPLN1 expression and matrix metalloproteinase 2 (MMP2) activity in cocultured BMSCs and MMP2 activity is higher in BMSCs established from multiple myeloma patients’ BM aspirates relative to normal equivalents. Moreover, MMP2 cleaves HAPLN1 into forms similar in size to those previously observed in patients with multiple myeloma with progressive disease. Both HAPLN1 and MMP2 in BMSCs were required to enhance NF-κB activation and resistance to bortezomib-induced cell death in cocultured multiple myeloma cells. We propose that MMP2-processing of HAPLN1 produces a matrikine that induces NF-κB activation and promotes bortezomib resistance in multiple myeloma cells.
Implications:
HAPLN1 and MMP2 produced by BMSCs obtained from patients with multiple myeloma promote NF-κB activity and resistance to bortezomib toxicity in multiple myeloma cells, uncovering their potential as biomarkers or therapeutic targets to address bortezomib resistance in patients with multiple myeloma.
Data from GFI1 Cooperates with IKZF1/IKAROS to Activate Gene Expression in T-cell Acute Lymphoblastic Leukemia
Authors: Sun Wenxiang , Guo Jingtao , McClellan David , Poeschla Alexandra , Bareyan Diana , Casey Mattie J. , Cairns Bradley R. , Tantin Dean , Engel Michael E.
Published: March 2024

Abstract
Growth factor independence-1 (GFI1) is a transcriptional repressor and master regulator of normal and malignant hematopoiesis. Repression by GFI1 is attributable to recruitment of LSD1-containing protein complexes via its SNAG domain. However, the full complement of GFI1 partners in transcriptional control is not known. We show that in T–acute lymphoblastic leukemia (ALL) cells, GFI1 and IKAROS are transcriptional partners that co-occupy regulatory regions of hallmark T-cell development genes. Transcriptional profiling reveals a subset of genes directly transactivated through the GFI1—IKAROS partnership. Among these is NOTCH3, a key factor in T-ALL pathogenesis. Surprisingly, NOTCH3 expression by GFI1 and IKAROS requires the GFI1 SNAG domain but occurs independent of SNAG—LSD1 binding. GFI1 variants deficient in LSD1 binding fail to activate NOTCH3, but conversely, small molecules that disrupt the SNAG—LSD1 interaction while leaving the SNAG primary structure intact stimulate NOTCH3 expression. These results identify a noncanonical transcriptional control mechanism in T-ALL which supports GFI1-mediated transactivation in partnership with IKAROS and suggest competition between LSD1-containing repressive complexes and others favoring transactivation.
Implications:
Combinatorial diversity and cooperation between DNA binding proteins and complexes assembled by them can direct context-dependent transcriptional outputs to control cell fate and may offer new insights for therapeutic targeting in cancer.