Bone metastasis is a common complication of advanced castration-resistant prostate cancer (CRPC), but there are no targeted treatments for bone metastasis. To address this, Kim and colleagues studied the transcriptional targets of pS473-TRIM28 and evaluated how the TRIM28/LDHA axis can be targeted to reduce bone metastasis in CRPC. RNA sequencing, DepMap-informed CRISPR-mediated knockout studies, CUT&RUN sequencing, and luciferase assays found a dependence on TRIM28 in prostate cancer cell lines and identified LDHA as a downstream target of TRIM28. Further analysis using Lactate-Glo assays and seahorse glycolytic assays showed a decrease in cellular and extracellular lactate levels and glycolytic activity upon TRIM28 knockdown, TRIM28-S473A expression, and LDHA knockdown compared to the control. IVIS analysis of C4-2B cells transduced with TRIM28 or LDHA knockdown constructs and injected into NSG mouse tibias found reduced bioluminescent signals in TRIM28 and LDHA knockdown tumors compared to the control. Rescue studies for TRIM28-S473 phosphorylation also exhibited reduced bioluminescent signals. The authors also treated bone metastatic prostate cancer models with LDH inhibitor, FX-11, finding a decrease in the colony formation ability in vitro and reduced bioluminescent signals in orthotopic bone injection models. Altogether, this study highlights the TRIM28/LDHA axis in CRPC and proposes it has a potential therapeutic target to reduce bone metastasis.Colorectal cancer is an aggressive malignancy with poor outcomes in late-stage patients. Despite this, our understanding of the molecular mechanism driving the progression of this disease is limited. In their study, Qi and colleagues analyzed a cohort of colorectal cancer transcriptomic datasets to determine the major contributors to colorectal cancer pathogenesis. Integrated transcriptomic analysis and LASSO analysis identified DBNDD1 as a key gene associated with colorectal cancer. Proliferation, apoptosis, and colony formation assays of DBNDD1 knockdown cells showed decreased proliferation and colony formation ability, but increased levels of apoptosis. Expression of mesenchymal markers and inflammatory markers were also reduced upon DBNDD1 knockdown. In vivo DBNDD1-deficient xenograft tumors had reduced volume and weight compared to the control, and the spleen capsule injection model and tail vein injection model using DBNDD1-deficient cells revealed a reduced number of metastases compared to the controls. Colocalization of DBNDD1 and GDF15 was observed using laser confocal microscopy, and coimmunoprecipitation demonstrated their direct interaction. Genetic manipulation of DBNDD1 and GDF15 in colorectal cancer cells further found that prometastatic markers were upregulated and the NF-κB signaling pathway was activated upon high expression of DBNDD1 and GDF15, indicating these molecules may have a tumor-promoting synergistic relationship.Cell death mechanisms in cancer are widely studied, but the molecular underpinning of chaperone-mediated autophagy (CMA) in HPV− head and neck squamous cell carcinoma (HNSCC) is unclear. To elucidate CMA substrates in HNSCC, Cao and colleagues perform integrated proteomics and motif analysis to find targets of rate-limiting protein LAMP2A. IP–LC/MS-MS analysis of HNSCC cells, followed by proteomics, identified SELENBP1 as an LAMP2A-interacting protein. Coimmunoprecipitation further validated direct interaction between SELENBP1 and LAMP2A. LAMP2A knockdown inhibited CMA and showed increased expression of SELENBP1. Additionally, overexpression of SELENBP1 decreased HNSCC cell proliferation and increased apoptosis, while CCK-8 assays, EdU assays, and flow cytometry analysis of LAMP2A knockdown cells demonstrated decreased cell viability and proliferation. Expression of cancer stem cell markers, the CD133+ cancer stem cell population, and tumor sphere formation ability were also decreased upon LAMP2A knockdown. The authors found that concurrent knockdown of SELENBP1 and LAMP2A rescued the apoptotic rate of HNSCC cells. Overall, this study highlights the role of CMA in HNSCC progression and identifies the LAMP2A–CMA–SELENBP1 axis.

The Molecular Cancer Research editors wish to acknowledge with sincere appreciation the assistance of the following reviewers who have generously contributed their time and effort during the past year1 in the appraisal of manuscripts. These reviewers have been enormously helpful in assessing the merit of original articles: their careful analysis and critique and their constructive recommendations have greatly enhanced the value of manuscripts they have handled. The quality of the journal can be attributed in large measure to the quality of their effort. We are sincerely grateful.Abdel-Wahab, O.Abel, E.Ager, C.Aird, K.Alberti, S.Ali, S.Alluri, P.Alvarez, J.Aoki, M.Aplin, A.Applebaum, M.Aqeilan, R.Arrieta, V.Ashkenazi, A.Atri, P.Avgeris, M.Baldari, C.Band, V.Barbieri, C.Barnoud, T.Barrett, M.Barta, J.Ben-Sahra, I.Bernards, R.Beverly, L.Bhatt, S.Bishnupuri, K.Blakely, A.Bozkurt, E.Bremner, R.Brennen, W.Brody, J.Broggini, M.Brown, A.Burdett, N.Burns, T.Byrne, F.Cai, H.Campbell, M.Cao, Y.Caplen, N.Carew, J.Carnero, A.Carr, R.Carroll, J.Cen, B.Centenera, M.Chadli, A.Chakrabarti, R.Chakraborty, A.Chakraborty, G.Chakravarti, D.Chalfant, C.Chan, J.Chang, Y.Chen, G.Chen, H.Chen, W.Chen, X.Chen, X.S.Chen, Y.Chernoff, J.Cheung, E.Ciardiello, F.Citron, F.Coarfa, C.Coffey, K.Condello, S.Cook, L.Cooper, S.Corey, E.Corver, W.Cress, A.Crisafulli, G.Curtis, M.Dai, W.Dallos, M.Das, C.Davies, K.de Joussineau, C.De Marzo, A.DeCaprio, J.Dela Cruz, F.Delahunty, R.Delattre, O.Deng, M.Deng, Y.Deraco, M.DeSisto, J.Dey, P.Di Vizio, D.Diergaarde, B.Dogan, A.Dong, Z.Dou, Y.Dowlati, A.Drew, D.Duan, D.Dumbrava, E.Dutt, A.Eferl, R.Eischen, C.Elf, S.Elias, R.Faber, A.Fassl, A.Fatatis, A.Faust Akl, C.Feigin, M.Fernandez-Zapico, M.Fidelito, G.Fiorentino, M.Fisher, P.Frank, D.French, C.Frigo, D.Fuchs, S.Fujimoto, J.Gabrielson, E.Gadad, S.Gallo, K.Gao, S.Gao, X.Gaughan, L.Geng, X.Geppetti, P.Ghosh, S.Giamas, G.Gibson, J.Giguere, V.Gilbert-Ross, M.Giordano, S.Golemis, E.Gonda, A.Govindarajan, R.Graham, D.Gray, J.Griffin, D.Grillo, G.Guilford, P.Guo, J.Guo, W.Haider, S.Hajirahimkhan, A.Hamidi, H.Harrell, J.Haugen, B.Hayman, T.He, Y.Healy, L.Hegde, S.Hemming, M.Henske, E.Hicks, J.Hogg, S.Holliday, H.Hollis, R.Hong, P.Horvath, L.Hossein, G.Hsu, T.Huang, S.Hudson, B.Hugh-White, R.Hurley, P.Ishii, H.Ishii, K.Islam, S.Ittmann, M.Janknecht, R.Jha, S.Jin, X.Jones, D.Kabos, P.Kang, C.Kato, T.Katzenellenbogen, B.Keklikoglou, I.Keller, E.Kenny, H.Keri, R.Keyomarsi, K.Kharas, M.Kim, K.Kim, M.Kirsch, D.Kittler, R.Knudsen, E.Kobarg, J.Kohsaka, S.Kosari, F.Koskinen, P.Kraus, W.Krum, S.Kuhn, P.Kundu, S.Kyprianou, N.Labanca, E.Lagerweij, T.Landry, A.Languino, L.Lathia, J.Law, B.Lazzara, M.Leandersson, K.Lee, M.Levi, M.Lewis, R.Li, J.Li, S.Li, T.Li, X.Li, Z.Liao, D.Lim, B.Lim, M.Lin, F.Liu, C.Liu, P.Liu, X.Lord, C.Louault, K.Lu, C.Luddy, K.Lundberg, A.Ma, G.Ma, L.Madak-Erdogan, Z.Malumbres, M.Mankoff, D.Mannan, R.Mantamadiotis, T.Marchionni, L.Marignol, L.Marks, J.Marzioni, D.Massari, F.Matei, D.Matsuda, K.Maynard, J.McEachron, T.McFadden, D.Medler, T.Mehta, G.Mei, S.Melotte, V.Migliore, C.Miles, W.Mills, I.Mischel, P.Mishra, A.Miyamoto, H.Mondal, J.Morelli, E.Moreno, C.Msaouel, P.Mucha, B.Muranen, T.Murga-Zamalloa, C.Murphy, M.Murtola, T.Mutch, D.Muzumdar, M.Naccarati, A.Nagathihalli, N.Nakagawa, H.Nakamura, T.Nelson, E.Nelson, P.Nonn, L.Offenbacher, R.Opferman, J.Ostrand-Rosenberg, S.Ostrander, J.Palmbos, P.Pan, Q.Park, J.Park, S.Park, W.Parmar, K.Pederzoli, F.Pereira-Martins, D.Pili, R.Pitarresi, J.Piwocka, K.Plymate, S.Porciuncula, A.Pratilas, C.Qian, B.Qin, Z.Quigley, D.Quinn, B.Raghavan, S.Ramos, K.Rangel, R.Rao, C.Rauh, D.Ribeiro, C.Ricciardelli, C.Richer, J.Roden, R.Rodrigues, F.Roper, N.Roussos Torres, E.Rovira, A.Saab, R.Sabnis, A.Sak, A.Salaroglio, I.Salzet, M.Sancisi, V.Sangaletti, S.Sareddy, G.Scagliotti, G.Schiemann, W.Schreck, K.Sena, L.Setaluri, V.Shafi, A.Sharifi, N.Shen, F.Shen, Z.Shern, J.Shiozawa, Y.Sholl, L.Shukla, S.Signoretti, S.Sladek, F.Sloan, E.Sloan, L.Smith, K.So, C.Solit, D.Somwar, R.Søreide, K.Sowalsky, A.Spangle, J.Spanheimer, P.Sprick, M.Su, R.Su, W.Su, X.Suematsu, M.Summers, M.Sun, M.Sun, S.Sunakawa, Y.Sutton, M.Swinnen, J.Tan, I.Tanaka, S.Tattersall, L.Tew, K.Tirosh, B.Toska, E.Trejo, J.Turajlic, S.van Gent, D.Van Tine, B.Varambally, S.Vaseva, A.Viswanath, P.Wajapeyee, N.Walker, S.Wan, J.Wang, B.Wang, H.Wang, J.Wang, N.Wang, QianbenWang, QiangWang, QingdingWang, Qi-EnWang, X.Wang, Y.Waugh, D.Webb, T.Wei, Q.Wei, W.Wellen, K.Westermack, J.Whitsett, T.Wilcox, R.Wilkinson, S.Wolf, D.Woo, J.Woolley, C.Wu, K.Xu, R.Yan, Q.Yan, Y.Yang, J.Yang, K.Yang, X.Yang, Y.Yates, M.Yi, J.Yoshida, A.Yu, K.Yu, W.Zadra, G.Zauderer, M.Zaytseva, Y.Zhan, C.Zhang, G.Zhang, H.Zhang, J.Zhang, L.Zhang, Y.Zhang, Z.Zhou, B.Zhu, W.Zi, X.Zimmerman, M.Zorko, N.

The interaction of ETS transcription factors and EWSR1 is associated with oncogenic function in prostate cancer and Ewing sarcoma. However, the mechanism of this pro-tumoral activity is unclear. In their study, Downing and colleagues investigated the specificity and overlap in ETS factors involved in gene fusions in Ewing sarcoma and prostate cancer. Proliferation and colony formation assays performed with EWSR1::FLI1 genetic knockdown Ewing sarcoma cells that express EWSR1::ETS fusion proteins demonstrated a rescue in colony formation ability for ETV1, ETV4, ETV5, and ERG S96E. Ewing sarcoma cells treated with EZH2 inhibitor GSK503 further showed rescue of colony formation ability in ERG expressing cells, indicating that EZH2 represses this process. Affinity pulldown revealed similar interactions between EZHZ and FOXO1 with ETS proteins, and immunoprecipitation in prostate cancer cells found an ERG/PRC2/FOXO1 complex. Pulldown of ERG in cells expressing low levels of FOXO1 also demonstrated reduced ERG/PRC2 interaction. Cells expressing high levels of AKT appeared to have depleted ERG/EZHZ interaction, while inhibition of AKT increased FOXO1. Altogether, this study shows that the ETS factors that drive Ewing sarcoma and prostate cancer are interchangeable, and that the mechanisms governing this process may be a candidate for therapeutic intervention in either malignancy.Temozolomide (TMZ) resistance is commonly developed in glioblastoma multiforme (GBM) patients, but little is known about its mechanism. In their study, Sui and colleagues identified a protein that modulates sensitivity to TMZ and evaluated the mechanism of its regulation. MTT assays using ACYP2 knockdown GBM cell lines treated with TMZ showed lower IC50 values in the knockdown compared to the control. ACYP2 knockdown cells also exhibited decreased proliferation, colony formation ability, and increased cell apoptosis upon treatment with TMZ. The opposite effect was observed upon ACYP2 overexpression in GBM cells. KEGG analysis of TCGA data further found an enrichment in differentially expressed genes associated with DNA repair pathways in patients with high expression of ACYP2. Comet tail assays and immunofluorescence staining also showed enhanced DNA damage upon ACPY2 knockdown and TMZ treatment, whereas overexpression of ACYP2 appeared to prevent DNA damage upon TMZ treatment. The authors also observed a correlation between c-Myc, a target of ACYP2, and PARP1. ChIP assays demonstrated c-Myc binding to PARP1 promoter, and dual-luciferase assays indicated c-Myc increased the transcriptional activity of the PARP1 promoter. In vivo analysis of ACYP2 knockdown also enhanced TMZ sensitivity in GBM-bearing mice, with the tumors presenting decreased levels of proliferation and growth compared to the control. Overall, this study proposes ACYP2 as a regulator of TMZ resistance and suggests that the ACYP2-driven c-Myc/PARP1 signaling axis may be targeted to remediate resistance in GBM.PTEN and SOX4, a respective tumor suppressor and transcription factor, have been clearly associated with prostate cancer progression, but the mechanism of their interaction is largely unknown. In their study, Sun and colleagues investigated the relationship between these two proteins and demonstrated their potential as therapeutic targets. Immunohistochemical staining of prostate cancer tissues revealed SOX4 and PTEN expression were inversely correlated, and that patients with SOX4+/PTEN– expression had a more aggressive phenotype, including castration-resistant prostate cancer. Further analysis in PTEN-intact prostate cancer cell lines showed that genetic manipulation of SOX4 altered PTEN protein expression but did not affect PTEN mRNA levels. A miRNA screen using TCGA and GSE data showed that the miR-106b∼25 cluster was positively correlated with SOX4 and predicted to target PTEN. Rescue experiments and dual-luciferase assays highlighted the inhibitory role of the miR-106b∼25 cluster on PTEN. Transcription factor binding databases, ChIP-qPCR, and luciferase reporter assays confirmed transcriptional regulation of the miR-106b∼25 cluster by SOX4. In vivo synergy analysis also demonstrated that SOX4 inhibition and LY294002, a small-molecule inhibitor that suppressed AKT signaling, could be combined to reduce tumor growth. Taken together, this study highlights the cooperation between SOX4 and PTEN and shows how they may be manipulated to improve patient outcomes.

Conventional therapies have demonstrated limited therapeutic efficacy in most ovarian cancer patients, highlighting the need to identify alternative therapeutic targets. In their study, Lesage and colleagues investigated how the ferroptosis pathway may be manipulated to improve the response of ovarian tumor cells to PARP inhibitors (PARPi). DDR2 knockdown CAF cell lines treated with ferroptosis inducers showed an accumulation of lipid peroxides that was reversable upon treatment with an iron chelator or treatment with a lipid peroxidation inhibitor. The authors also found that expression of the antioxidant xCT-GSH-GPX4 axis was depleted upon DDR2 knockdown in CAF cell lines. Intracellular ROS levels measured using superoxide indicator dye DHE after treatment with hydrogen peroxide also exhibited enhanced levels of ROS in DDR2 depleted cells. DDR2 proficient and deficient cells treated with an NRF2 inhibitor or activator, respectively, revealed that DDR2 modulates ferroptosis through a p62-KEAP1-NRF2-dependent pathway. Interestingly, immunohistochemical analyses of ovarian tumor tissues and single cell RNA-sequencing showed an association between DDR2 expression and clinical PARPi resistance. Cell death assays performed with DDR2 proficient and deficient cells treated with olaparib validated these findings, with enhanced olaparib sensitivity observed in DDR2 deficient cells compared to proficient cells. Taken together, this study demonstrates the role of DDR2 in CAF-mediated ferroptosis sensitivity and highlights the utility of DDR2 targeting to improve PARPi response in ovarian cancer.The tumor microenvironment (TME) plays an important role in cancer progression and treatment response, but there are limited modalities to study the TME at the genomic level in established clinically annotated cancer multi-omics cohorts. To address this, Bayati and colleagues developed the PACIFIC method, which allowed them to evaluate how genomic alterations in cancer cells interact with transcriptome-derived immune signatures in TCGA datasets corresponding to 26 different cancer types. Utilizing PACIFIC, the authors found that immunogenomic interactions were associated with survival, and that driver mutations including those in PIK3CA and KMT2D were similarly associated with immunogenomic interactions in specific cancer types. In addition, the authors observed an association between genomic deletions and decreased expression of tumor suppressors, and genomic gains with increased expression of oncogenes. Immunogenomic interactions also demonstrated an association with prognosis, specific immune cell populations, and ICI targets. The utility of immunogenomic interactions as biomarkers and potential therapeutic targets was also indicated using the loss of MEN1 in luminal-A breast cancer as a model. Altogether, this study proposes a computational methodology to evaluate immunogenomic interactions in the context of tumor progression and therapeutics and emphasizes the value of understanding the interactions of the TME and genomic alterations in tumors.FOXA1 is a key transcriptional regulator and promising therapeutic target in hormone-dependent cancers. However, our understanding of its regulatory mechanism and protein interactions is limited. To address this, Plagens and colleagues mapped the FOXA1 interactome in ER-positive breast cancer. Proximity-dependent biotinylation using miniTurbo labeling and LC-MS/MS analysis of FOXA1 in MCF-7 cells revealed a high-confidence FOXA1-interactome comprised of 185 proteins, including known FOXA1 interactors. Comparison against the known BioGRID database for FOXA1 interactors showed that miniTurbo labeling identified 157 novel interactions. One candidate protein, NR2C2, also demonstrated strong interaction with FOXA1 in coimmunoprecipitation assays of ER-positive breast cancer cells. Further ChIP-seq and motif analysis of FOXA1 proficient and deficient MCF-7 cells found altered NR2C2 binding in FOXA1 deficient cells, specifically noting enhanced binding of NR2C2 to the NFIL3 motif. The authors also observed patterns of FOXA1-independent and -dependent NR2C2 binding, where NR2C2 binding at the ESR1 promoter was found to be FOXA1-dependent. FOXA1/NR2C2 codependent genes, including EXO1, CCNA2, and RUVBL2, were also identified using transcriptome analysis and ChIP-sequencing. Overall, this study defines the FOXA1/NR2C2 interaction and provides a resource for future mechanistic studies that interrogate the FOXA1 interactome.

Hepatoblastoma (HBL) and fibrolamellar carcinoma (FLC) are both rare forms of liver cancer with largely unstudied mechanisms of pathogenesis. In their study, Fleifil and colleagues explored the role of J-PKAc–β-catenin and the cohesin ring in oncogenic activation. Immunoprecipitation assays revealed that a complex of CTCF, Rad21, SMC3 and SMC1 forms in HBL, and that these proteins bind to CEGRs/ALCD, the CTCF consensus binding site, and to the NRF2 promoter through TCF4/TCF4–β-catenin interaction. Immunofluorescence and BET bromodomain inhibition studies using liver cancer cell lines showed that the cohesin ring cooperates with ph-S675–β-catenin in activating CEGRs/ALCD-containing oncogenes and promoting cell proliferation in a Rad21-dependent manner. The authors also found that FLC patients had increased levels of cohesin ring proteins and β-catenin–CEGRs/ALCD targets. Further ChIP analysis demonstrated that the cohesin ring binds to the Thy1 promoter and CEGR/ALCD in FLC. Overall, this study illustrates the cooperation of J-PKAc–β-catenin and the cohesin ring in HBL and FLC and emphasizes the importance of understanding the complex mechanisms underlying oncogenesis.Merkel cell carcinoma (MCC) is a rare skin cancer often caused by Merkel cell polyomavirus (MCPyV). Despite this, our understanding of MCPyV genomic integration and its functional implications is limited. To address this deficiency, Smith and colleagues evaluated the tumor mutational burden and copy-number variation present in virus-positive (VP) and virus-negative (VN) MCC and created an informatics pipeline for MCPyV genomic integration analysis. Genomic analyses of VP-MCC and VN-MCC identified a higher number of activating alterations in VN-MCC, specifically in proto-oncogenes and genes driving epigenetic silencing, including KMT2B, KMT2C, KMT2D, DNMT1, and ARID1B. Inactivating mutations for key tumor suppressor genes, such as RB1, TP53, NOTCH1, and PTEN were also found in the majority of VN-MCC tumors. Genomic scores based on tumor mutational burden and copy-number variation in patients with lymph node metastasis and MCPyV showed patients with high TMB and CNV had poorer survival compared to patients with low TMB and CNV. Taken together, this study dissects MCPyV genomic integration and introduces MCPyViewer, a resource-based informatics pipeline that can be used to visualize MCPyV integration sites.HNF4α is an important transcriptional regulator for the classical subtype of pancreatic ductal adenocarcinoma (PDAC). To determine the significance of HNF4α isoforms in PDAC subtypes, Fang and colleagues studied how isoforms driven by either the P1 or P2 promoter contribute to PDAC progression and differentiation. In vitro analysis of the P1 isoform, HNF4α2, and the P2 isoform, HNF4α8, revealed that expression of P1 and P2 isoforms hinder PDAC proliferation. RNA sequencing and GSEA of PDAC cells expressing either isoform further showed that the P1 isoform strongly inhibits signatures for normal squamous cell and basal-like PDAC. A scatterplot of the DEGs significantly regulated by both isoforms and ChIP sequencing further demonstrated that P1 isoforms are stronger transcriptional regulators compared to P2 isoforms. CRISPRi competition assays using P1 and P2 knockdown PDAC cells also found a greater functional effect for dual knockdown cells, indicating their partial redundancy. Cell line dependent P1 and P2 transcriptional regulation was also observed. These findings altogether highlight the role of HNF4α isoforms across PDAC subtypes and suggest that isoforms of key transcriptional regulators may play important roles in cancer progression.

Bispecific antibodies functioning as T-cell engagers have emerged as a unique treatment strategy to facilitate the interaction between immune cells and cancer cells, forcing clearance of cancerous cells. In prostate cancer, a novel mechanism of immunogenic reprogramming is highlighted with a bispecific integrin α5β1/αv antibody (BsAbα5β1/αv) which triggers the degradation of key integrins implicated in metastatic progression and tumor-stromal interactions. To determine the significance of this loss of integrin expression, Joshi and colleagues investigated the pathological signaling pathways impacted by BsAbα5β1/αv treatment. Subcellular fractionation and RNA sequencing of basal-type prostate cancer cells treated with BsAbα5β1/αv showed reduced nuclear localization and decreased enrichment of gene sets associated with YAP, β-catenin, and FAK compared to controls. Prostate cancer xenografts in nude mice further demonstrated that the BsAbα5β1/αv eliminated clonogenic survival of basal-type tumors and had a significantly greater effect on complete tumor regression and survival than monoclonal antibodies. Engrafted tumors were inflamed with innate immune cells following BsAbα5β1/αv treatment, and tumor elimination required natural killer (NK) cells. Additional studies using RNA sequencing indicated that treatment with BsAbα5β1/αv decreased Myc/E2F, EMT and TGF-β signaling and activated type I and type II interferon responses in vitro and in vivo. Enhanced tumor-autonomous CXCL10 and CCL5 chemokine secretion was demonstrated, which is linked to NK cell recruitment. In vivo clonogenic survival assays performed with isogenic PTEN mutant prostate cancer cells indicated that BsAbα5β1/αv is effective independent of PTEN inactivation. High-frequency target integrin expression in metastatic disease samples was demonstrated, with principal correlation of integrin αv with the Myc pathway and integrin α5 with EMT respectively. Taken together, this study implicates mechanosignaling by integrins αv and α5 in lethal prostate cancer and establishes BsAbα5β1/αv integrin therapy as a novel immunological strategy to control Myc, EMT and TGF-β signaling, critical regulators of the immune-suppressed tumor microenvironment.Luminal progenitor cells have been widely associated with triple-negative breast cancer (TNBC) initiation and progression. In their study, Xu and colleagues found that the long non-coding RNA LINC01235 acts as a transcriptional regulator and modulates the luminal progenitor-like cells of TNBC. Patient-derived organoids of TNBC were analyzed using single cell RNA sequencing and single-molecule RNA fluorescence in situ hybridization, which demonstrated enriched expression of chromatin-associated LINC01235 in the luminal progenitor-enriched cell populations expressing EpCAM and CD49f surface proteins. TNBC cell lines and organoid lines treated with LINC01235-specific antisense oligonucleotides were found to have reduced viability and organoid formation, respectively, compared to the control. MTT and rescue assays performed with a CRISPR/Cas9-mediated LINC01235 knockout TNBC cell line further confirmed LINC01235 mediates proliferation. TNBC cells subjected to chromatin isolation by RNA purification revealed that LINC01235 directly binds to the promoter of NFIB. Correspondingly, the expression of NFIB-regulated NOTCH1 and NOTCH3, were found to be significantly decreased in LINC01235 knockout cells. These findings altogether indicate that LINC01235 functions as a transcriptional regulator of the NFIB/Notch axis and proposes a luminal progenitor cell-associated pathway that may be targeted to improve TNBC outcomes.PAD2, a peptidyl-arginine deiminase, is understood to function as an epigenetic regulator of histone citrullination, but its significance and mechanism in pancreatic ductal adenocarcinoma (PDAC) are largely unknown. To address this gap, Umemura and colleagues utilized in vitro and in vivo models to understand the role of PAD2 in histone citrullination and the tumor microenvironment modulation. Immunohistochemical analysis of PDAC tissues indicated an association between nuclear expression of PAD2 and citrullinated H3R2/8/17 (Cit-H3), both of which were correlated with poor patient prognosis. Expression analyses of knockdown cell line models and PDAC tissues also found that nuclear expression of PAD2 may be RAN-dependent. RNA sequencing, ChIP, and chromatin accessibility assays of PAD2 knockdown cell lines demonstrated that PAD2 catalyzes histone citrullination at the PRUNE1 and E2F1 promoters, thereby enhancing chromatin accessibility and upregulating the expression of these genes. The authors also showed that PAD2-mediated PRUNE1 expression promotes tumor growth and M2 polarization using subcutaneous xenograft models, immunofluorescence staining, and M2 macrophage polarization assays. Syngeneic mouse models and human PDAC tissues supported a tumorigenic PAD2/PRUNE1 axis that influences macrophage subpopulations. Overall, these findings revealed a pathway of PAD2 histone citrullination that impacts the tumor immune microenvironment and patient outcomes.

Glioblastoma multiforme (GBM) is a highly aggressive brain tumor with a poor prognosis. Temozolomide (TMZ) is the most widely used chemotherapeutic agent and can significantly improve patient survival rates. However, numerous patients develop TMZ resistance, leading to limited therapeutic benefits. Therefore, it is crucial to investigate the mechanisms of TMZ resistance in patients with GBM and identify the sensitizing targets of TMZ to improve its clinical efficacy. In this study, we demonstrated that acylphosphatase 2 (ACYP2) was involved in regulating the sensitivity of GBM to TMZ. ACYP2 knockdown significantly reduced the IC50 values of TMZ in GBM cells, whereas overexpression of ACYP2 increased their IC50 values. The combination of ACYP2 knockdown and TMZ treatment not only inhibited the malignant behavior of GBM cells in vitro but also slowed the progression of intracranial GBM in mice. Additionally, comet tail and γ-H2AX staining assays showed that ACYP2 knockdown enhanced the TMZ-induced DNA damage. Mechanistically, ACYP2 upregulates the transcription factor c-Myc to promote the transcription of its downstream target PARP1, an important regulatory molecule for DNA damage repair, ultimately inducing TMZ resistance in GBM cells. Thus, this study demonstrated that ACYP2 is a potential therapeutic target for TMZ-resistant patients with GBM.Implications:The ACYP2-driven c-Myc/PARP1 signaling axis defines a critical pathway driving TMZ resistance and represents a translationally actionable target for therapeutic intervention in GBM.

Bone metastasis is a commonly observed phenomenon in prostate cancer patients and is the primary cause of death. Despite the prominent osteoblastic nature of bone-metastatic prostate cancer, targeted therapeutics aimed at bone-metastatic prostate cancer are mainly focused on inhibition of osteolysis. In their study, Johnson and colleagues aimed to elucidate the significance of bone-metastatic prostate cancer-induced mesenchymal stem cell (MSC) CXCL8 expression on osteogenesis. The authors performed Alizarin Red and alkaline phosphatase assays on murine CRISPR-Cas9 Cxcl1 (murine homolog of CXCL8) knockout MSCs to evaluate its role in osteoblastogenesis and found enhanced calcium deposits and increased alkaline phosphatase activity in Cxcl1 knockout MSCs compared to control MSCs. The expression of osteoblastic transcription factors RUNX2 and OSX were differentially altered in murine Cxcl1 knockout MSCs and human bone marrow CXCL8 knockdown MSCs, suggesting a regulatory role of CXCL8 in MSC differentiation. RNA sequencing and subsequent analysis of differentially expressed genes using GO enrichment and GSEA for Cxcl1 knockout MSCs showed altered enrichment of genes associated with extracellular matrix remodeling, steroid metabolism, and immune activation. Ex vivo tibias derived from in vivo bone metastasis studies using intratibial injection of murine Cxcl1 knockout MSCs, revealed increased Trichrome staining in Cxcl1 knockout MSC tumors compared to the control. Although CXCL1 blockade increased MSC osteogenesis, Cxcl1 knockout MSCs significantly suppressed tumor growth and altered neutrophil phenotypes in vivo. Overall, this study demonstrates the regulatory function of CXCL1 in osteogenesis and the bone microenvironment and proposes its potential as a therapeutic target in bone-metastatic prostate cancer.Pseudogene-derived lncRNA SFTA1P has recently been linked with the development of multiple cancers, but its mechanism of action remains largely unstudied. To investigate the molecular function of SFTA1P in non-small cell lung cancer (NSCLC), Xia and colleagues evaluated SFTA1P for its impact on gene regulation and tumor progression. Proliferation, migration, and invasion assays using SFTA1P overexpressing and deficient lung cancer cells showed that SFTAP1 induced an inhibitory effect on cancer progression. In vivo subcutaneous xenograft tumor models and tail vein injection metastasis models using SFTA1P overexpressing lung cancer cells demonstrated a similar inhibitory effect on tumor development and dissemination compared to the control. The authors also analyzed the SFTA1P/miR-665/TGFBR2 regulatory network using luciferase reporter assays, RNA-seq data, and RNA immunoprecipitation assays, and found that the ceRNA SFTA1P may modulate TGFBR2 by sponging miR-665 in the cytoplasm. Additional GO analysis, GSEA, and RNA pull-down assays using SFTA1P overexpressing cells revealed that SFTA1P/P-TEFb complex interaction inhibited RNA Pol II function in the nucleus. RNA immunoprecipitation assays also found an interaction between nuclear m6A reader YTHDC1 and SFTA1P and showed a YTHDC1-dependent differential localization of SFTA1P. Taken together, this study demonstrates that SFTA1P functions as a tumor suppressor pseudogene in NSCLC by orchestrating TGFBR2 and P-TEFb interactions, revealing its clinical potential.N6-methyladenosine (m6A) modifications are widely acknowledged as significant players in cancer development and progression. Despite this, the function and mechanism of m6A in gastric cancer is poorly understood. In their study, Hu and colleagues evaluated m6A modifications in the context of gastric cancer by analyzing METTL3, a key enzyme involved in m6A deposition. Analysis of METTL3 knockdown cells using MTT, colony formation, and migration assays demonstrated a decrease in the proliferative ability of METTL3 deficient cells compared to the control. A Dot blot also showed a significant decrease in the RNA m6A level in METTL3 deficient cells. Interaction between METTL3 and FNTA, resulting in METTL3-mediated m6A deposition on FNTA, was observed using RNA immunoprecipitation assays. Further analysis of this interaction through RNA immunoprecipitation and computational tools demonstrated interaction between m6A reader YTHDF1 and FNTA mRNA, highlighting YTHDF1 as a regulator of FNTA translation. Luciferase assays validated the METTL3/YTHDF1/FNTA axis, and in vivo tumor models and tail vein metastasis models demonstrated the pro-tumoral function of METTL3 and FNTA. METTL3 was also shown to promote KRAS localization to the plasma membrane, resulting in enhanced MEK/ERK signaling. Altogether, this study shows that METTL3 is responsible for m6A modification deposition on FNTA in a YTHDF1-dependent manner, resulting in KRAS plasma membrane localization and cancer progression.

Intrahepatic cholangiocarcinoma (ICC) is the second most common liver cancer. LINC00519 plays a prominent role in the progression of numerous cancers. To explore the molecular mechanism of LINC00519 in ICC, the expressions of LINC00519, hsa-miR-22-3p, and MECOM in ICC were assessed using the ENCORI database and qRT-PCR. The biological functions of LINC00519 in ICC were examined using a clone formation experiment, Transwell analysis, flow cytometry, and Western blot. Meanwhile, the mechanism of LINC00519 in ICC was determined by a dual-luciferase reporter assay. Results showed that LINC00519 and MECOM were highly expressed in ICC, whereas hsa-miR-22-3p was decreased. Functionally, silencing LINC00519 weakened ICC cell proliferation and migration and induced cell apoptosis. Also, LINC00519 knockdown repressed the PI3K/AKT (protein kinase B) pathway. Mechanistically, LINC00519 acted as a competitive endogenous RNA to target MECOM by sponging hsa-miR-22-3p. Meanwhile, rescue assays further proved that low LINC00519 expression restrained ICC cell proliferation and migration and accelerated apoptosis through the PI3K/AKT pathway by miR-22-3p/MECOM. In conclusion, this research revealed a novel LINC00519/hsa-miR-22-3p/MECOM regulatory axis and PI3K/AKT pathway that modulated ICC progression.Implications:This study deepens the understanding of the noncoding RNA regulatory network in ICC and provides potential targets for the diagnosis and targeted therapy of ICC.