OBJECTIVE:Episcleral plaque brachytherapy (EPBT) provides effective local tumor control in uveal melanoma (UM), although dosing regimens vary across institutions. We report a single institution's experience of using low-dose-rate Iodine-125 EPBT for the treatment of UM over a period of 38 years, evaluating long-term outcomes, complications, and survival rates. DESIGN:Retrospective chart review. SUBJECTS:One-thousand eight-hundred-seven patients diagnosed with UM and treated with low-dose-rate Iodine-125 EPBT between 1984 and 2022. METHODS:We reviewed medical records of UM patients treated with EPBT between 1984 and 2022 where we delivered a targeted dose of 85 Gy to the tumor apex at a rate of 52.8 cGy/hour over 168 hours. We applied Cox proportional hazards models and Kaplan-Meier survival analysis to evaluate survival outcomes and recurrence risks. MAIN OUTCOME MEASURES:Local tumor control, incidence of radiation-related complications, disease-specific, and overall patient survival. RESULTS:Of 1807 patients, 1674 (93%) achieved local control, 762 (42%) developed radiation retinopathy, and 332 (18%) developed radiation optic neuropathy. Kaplan-Meier estimates of local recurrence at 5 and 10 years were 12% and 18%, respectively. Increasing age (P = 0.01) and juxtapapillary location (P < 0.001) were correlated with increased risk of recurrence. At 10 years, 1472 patients (82%) were alive without metastasis, 75 (4%) were alive with metastasis, 120 (7%) had died from metastasis, 27 (2%) had died from non-UM causes, and 113 (6%) had died from unknown causes. Age at surgery and advanced American Joint Cancer Committee T stage were associated with lower overall survival (P < 0.001). CONCLUSIONS:Low-dose-rate Iodine-125 EPBT yields similar complication rates to those reported in the literature. The incidence of local recurrence, albeit slightly higher, was comparable to other large cohorts. The consistency of low-dose-rate EPBT over 3 decades served as a reliable framework for a standardized UM treatment protocol. FINANCIAL DISCLOSURE(S):Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Ovarian cancer (OC) remains a significant health issue for women due to its late diagnosis and chemoresistance. Currently, there is no relevant mouse OC model for preclinical drug screening and treatment. We established a mouse OC cell line model, PC53K, by transforming primary ovarian surface epithelial cells through CRISPR/Cas9-mediated TP53 knockout and simultaneous overexpression of human PTK2 and cMyc. We further developed the paclitaxel-resistant PC53K/TxR cell line. PC53K and PC53K/TxR cell lines were validated in vitro and in vivo in an orthotopic mouse model. We also evaluated the efficacy of two novel tubulin inhibitors, the clinical drug VERU-111 and the preclinical compound SB-216, using the PC53K/TxR model in vitro and in vivo. Mice intrabursally injected with PC53K cells exhibited bloody ascites, aggressive primary tumor growth and widespread metastasis, which faithfully recapitulates the phenotypes of human ovarian serous adenocarcinoma. Additionally, the paclitaxel-resistant PC53K/TxR cell line shows significant higher IC50 for paclitaxel than PC53K cell line, indicating it is a valuable tool for studying OC chemoresistance. Compounds VERU-111 and SB-216 significantly inhibited tumor growth and metastasis in orthotopic OC mouse models by overcoming chemoresistance. This study demonstrates the effectiveness of the PC53K and PC53K/TxR models for preclinical drug screening and validates the potential of VERU-111 and SB-216 in overcoming chemoresistance and treating OC. The development of the PC53K and PC53K/TxR mouse models represents a significant advancement in OC research. By mimicking the genetic profile, aggressive behavior and chemoresistance of human OC, these models provide a robust platform for preclinical drug discovery and development. Ziping Liu, Wenjing Zhang, Xinxin Zhao, Yongshuai Li, Xiaoya Hou, Satyanarayana Pochampally, Shelby Waddell, Shiji Song, Yaohong Wang, Lawrence M. Pfeffer, Duane D. Miller, Junming Yue, Wei Li. A p53-deficient, PTK2/cMyc-driven ovarian cancer mouse model for preclinical drug discovery [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 3922.

Deoxyhypusine synthase (DHPS) is an enzyme encoded by the DHPS gene, with high expression in various cancers, including ovarian cancer (OC). DHPS regulates the translation initiation factor EIF5A, and EIF5A2 knockout inhibits OC tumor growth and metastasis by blocking the epithelial-to-mesenchymal transition (EMT) and the TGFβ pathway. In this study, we show that DHPS is amplified in OC patients, and its elevated expression correlates with poor survival. Using lentiviral CRISPR/Cas9 vectors for DHPS knockout, we observed EMT inhibition in SKOV3 and OVCAR8 cells through suppressed hypusination and reduced EIF5A2 expression. Inhibition of DHPS activity with GC7 similarly blocked hypusination and EMT. Disrupting DHPS expression, either genetically or pharmacologically, inhibited primary tumor growth and metastasis in OC mouse models. These findings suggest that targeting DHPS and inhibiting hypusination could be promising strategies for OC treatment.

Background/Objectives: Human glioblastoma (GBM) is the most aggressive brain cancer in adults and a highly treatment-refractory malignancy. The overall prognosis for the GBM is extremely poor, with a median survival of 12–14 months after initial diagnosis. Many GBM patients initially respond to the DNA alkylating agent temozolomide (TMZ), but patients often become therapy-resistant, and tumors recur. We previously reported that treatment with PFI-3, which is a small molecule inhibitor of the bromodomain of the BRG1 subunit of the SW1/SNF chromatin remodeling complex, enhanced the sensitivity of GBM cells to TMZ in vitro and in vivo GBM animal models. Our general objective was to perform an SAR study of new diphenyl PFI-3 analogs. Methods: New structural analogs of PFI-3 were developed, synthesized, and tested for their ability to enhance TMZ-induced GBM cell death by ELISA. Results: Following on the enhanced activity of compounds 2a and 2b, new diphenyl PFI-3 analogs with specific structural adjustments were made to better understand the structural requirements to optimize function. Additionally, several new structurally different candidates (e.g., 4a, 4b, and 5) showed much better efficacy in sensitizing GBM cells to TMZ-induced GBM cell death. Conclusions: Four series of PFI-3 analogs (2, 3, 4, and 5) were designed, synthesized, and tested for the ability to sensitize GBM cells to TMZ-induced cell death. Series 2 optimized the A-ring and R-isomer chirality. Series 3 used a 5-membered linker with weak activity. Series 4’s di-phenyl urea compounds showed better bromodomain inhibition. Series 5’s methoxyphenyl-B-ring analogs were exceptionally strong inhibitors.

BRG1 and BRM are subunits of the SWI/SNF chromatin remodelling complex, which has DNA-stimulated ATPase activity and can destabilise histone-DNA interactions. Targeting SWI/SNF is beneficial for treating various tumours, including glioblastoma (GBM). Our research focussed on BRG1 due to its overexpression in GBM. We developed IV-255, a selective bromodomain (BRD) inhibitor that binds to BRG1 but not BRM. IV-255 sensitised GBM cells to temozolomide (TMZ), the standard GBM treatment. We identified the binding site of IV-255 within the BRG1 BRD and found that the Tyr1497 residue is crucial for IV-255's effect on TMZ-induced GBM cell death, while Asn1540 is not. Structural analyses confirmed that Tyr1497 is involved in the IV-255 binding pocket. Mechanistically, IV-255 increases γH2AX staining in GBM cell nuclei in response to TMZ, indicating an impaired DNA double-strand break response dependent on Tyr1497. IV-255 also sensitised GBM cells to TMZ-induced apoptosis, as shown by PARP and caspase-3 cleavage, which also requires Tyr1497. In conclusion, Tyr1497 within the BRD of BRG1 is critical for its interaction with IV-255 and for sensitising GBM cells to TMZ-induced DNA double-strand breaks and apoptotic cell death.

MicroRNAs (miRNAs) can function as either tumor suppressors or oncogenes. This study explores the role of miR-675 in ovarian cancer (OC) using in vitro OC cell lines and an in vivo orthotopic mouse model. We demonstrate that miR-675 expression inhibits primary tumor growth and metastasis by targeting TGFI31, suppressing epithelial to mesenchymal transition (EMT), and attenuating the TGFI3 signaling pathway. Functional assays revealed significant inhibition of cell proliferation, migration, and invasion by miR-675. In addition, miR-675 synergistically enhanced the apoptotic effect of paclitaxel and carboplatin, suggesting potential for combination therapy of miRNA-675 with chemotherapeutic agents. In vivo studies using orthotopic injection of miR-675 expressing and control OC cells in NSG mice demonstrated significant inhibition of primary OC growth and metastasis. These findings indicate that miR-675 is a promising therapeutic target for OC treatment.

The Ccr4-Not complex containing the Not4 ubiquitin ligase regulates gene transcription and mRNA decay, yet it also has poorly defined roles in translation, proteostasis, and endolysosomal-dependent nutrient signaling. To define how Ccr4-Not mediated ubiquitin signaling regulates these additional processes, we performed quantitative proteomics in the yeast Saccharomyces cerevisiae lacking the Not4 ubiquitin ligase, and also in cells overexpressing either wild-type or functionally inactive ligase. Herein, we provide evidence that both increased and decreased Ccr4-Not ubiquitin signaling disrupts ribosomal protein (RP) homeostasis independently of reduced RP mRNA changes or reductions in known Not4 ribosomal substrates. Surprisingly, we also find that both Not4-mediated ubiquitin signaling, and the Ccr4 subunit, actively inhibit 40S ribosomal autophagy. This 40S autophagy is independent of canonical Atg7-dependent macroautophagy, thus indicating microautophagy activation is responsible. Furthermore, the Not4 ligase genetically interacts with endolysosomal pathway effectors to control both RP expression and 40S autophagy efficiency. Overall, we demonstrate that balanced Ccr4-Not ligase activity maintains RP homeostasis, and that Ccr4-Not ubiquitin signaling interacts with the endolysosomal pathway to both regulate RP expression and inhibit 40S ribosomal autophagy.

Cancers develop resistance to inhibitors of oncogenes mainly due to target- centric mechanisms such as mutations and splicing. While inhibitors or antagonists force targets to unnatural conformation contributing to protein instability and resistance, activating tumor suppressors may maintain the protein in an agonistic conformation to elicit sustainable growth inhibition. Due to the lack of tumor suppressor agonists, this hypothesis and the mechanisms underlying resistance are not understood. In estrogen receptor (ER)- positive breast cancer (BC), androgen receptor (AR) is a druggable tumor suppressor offering a promising avenue for this investigation. Spatial genomics suggests that the molecular portrait of AR- expressing BC cells in tumor microenvironment corresponds to better overall patient survival, clinically confirming AR's role as a tumor suppressor. Ligand activation of AR in ER- positive BC xenografts reprograms cistromes, inhibits oncogenic pathways, and promotes cellular elasticity toward a more differentiated state. Sustained AR activation results in cistrome rearrangement toward transcription factor PROP paired- like homeobox 1, transformation of AR into oncogene, and activation of the Janus kinase/signal transducer (JAK/STAT) pathway, all culminating in lineage plasticity to an aggressive resistant subtype. While the molecular profile of AR agonist- sensitive tumors corresponds to better patient survival, the profile represented in the resistant phenotype corresponds to shorter survival. Inhibition of activated oncogenes in resistant tumors reduces growth and resensitizes them to AR agonists. These findings indicate that persistent activation of a context- dependent tumor suppressor may lead to resistance through lineage plasticity- driven tumor metamorphosis. Our work provides a framework to explore the above phenomenon across multiple cancer types and underscores the importance of factoring sensitization of tumor suppressor targets while developing agonist-like drugs.

UVR decreased melanoma susceptibility to CTLs which required IRF3.

<p>UVB-induced NF-kB activation is independent of p38, CK2, TAK1 and DDR kinases.</p>

Supplementary Figures and Tables

Supplementary Figure S1. Survivin and EMT markers were stained in sections of ovarian tumor of survivin KO and control mice; Supplementary Figure S2. Ovarian cancer cell migration and invasion following inhibition of apoptosis; Supplementary Figure S3. Cell viability in the upper chamber following treatment of MX106 in the migration assay; Supplementary Figure S4. Cell viability in the upper chamber following treatment of MX106 in the invasion assay; Supplementary Figure S5. SMAD dependent reporter gene luciferase activity; Supplementary Figure S6. TGFβ did not activate non-SMAD pathway in ovarian cancer cells; Supplementary Figure S7. Immunostaining for survivin and EMT markers in sections of ovarian tumor tissue following MX106 or vehicle treatment.

Glioblastoma (GBM) is an aggressive brain cancer with a poor prognosis. While surgical resection is the primary treatment, adjuvant temozolomide (TMZ) chemotherapy and radiotherapy only provide slight improvement in disease course and outcome. Unfortunately, most treated patients experience recurrence of highly aggressive, therapy-resistant tumours and eventually succumb to the disease. To increase chemosensitivity and overcome therapy resistance, we have modified the chemical structure of the PFI-3 bromodomain inhibitor of the BRG1 and BRM catalytic subunits of the SWI/SNF chromatin remodelling complex. Our modifications resulted in compounds that sensitized GBM to the DNA alkylating agent TMZ and the radiomimetic bleomycin. We screened these chemical analogues using a cell death ELISA with GBM cell lines and a cellular thermal shift assay using epitope tagged BRG1 or BRM bromodomains expressed in GBM cells. An active analogue, IV-129, was then identified and further modified, resulting in new generation of bromodomain inhibitors with distinct properties. IV-255 and IV-275 had higher bioactivity than IV-129, with IV-255 selectively binding to the bromodomain of BRG1 and not BRM, while IV-275 bound well to both BRG1 and BRM bromodomains. In contrast, IV-191 did not bind to either bromodomain or alter GBM chemosensitivity. Importantly, both IV-255 and IV-275 markedly increased the extent of DNA damage induced by TMZ and bleomycin as determined by nuclear γH2AX staining. Our results demonstrate that these next-generation inhibitors selectively bind to the bromodomains of catalytic subunits of the SWI/SNF complex and sensitize GBM to the anticancer effects of TMZ and bleomycin. This approach holds promise for improving the treatment of GBM.

<p>UVR-promoted melanoma evasion from CTL cytotoxicity, in an IRF3-dependent manner, was mitigated by blocking PD-1/PD-L1.</p>

Glioblastoma (GBM) is the most common primary brain malignancy in adults with a dismal prognosis. Despite advances in genomic analysis and surgical technique and the development of targeted therapeutics, most treatment options are ineffective and mainly palliative. Autophagy is a form of cellular self-digestion with the goal of recycling intracellular components to maintain cell metabolism. Here, we describe some recent findings that suggest GBM tumors are more sensitive to the excessive overactivation of autophagy leading to autophagy-dependent cell death. GBM cancer stem cells (GSCs) are a subset of the GBM tumor population that play critical roles in tumor formation and progression, metastasis, and relapse, and they are inherently resistant to most therapeutic strategies. Evidence suggests that GSCs are able to adapt to a tumor microenvironment of hypoxia, acidosis, and lack of nutrients. These findings have suggested that autophagy may promote and maintain the stem-like state of GSCs as well as their resistance to cancer treatment. However, autophagy is a double-edged sword and may have anti-tumor properties under certain conditions. The role of the STAT3 transcription factor in autophagy is also described. These findings provide the basis for future research aimed at targeting the autophagy-dependent pathway to overcome the inherent therapeutic resistance of GBM in general and to specifically target the highly therapy-resistant GSC population through autophagy regulation.