The Golgi apparatus is a central hub for protein trafficking and signaling, yet its rapid imaging and cell-selective disruption remain challenging. Here, we report cycling molecular assemblies (CyMA) for fast Golgi imaging and cell-selective interference. CyMA precursors are acetylated amphiphilic thiopeptides that traverse plasma membrane and are deacetylated by intracellular thioesterases. This exposes thiols that undergo palmitoylation by Golgi-resident palmitoyl acyltransferases utilizing palmitoyl-CoA. The resulting palmitoylated peptides self-assemble into dynamic nanostructures (i.e., CyMA) localized at the Golgi. Their continuous, reversible S-acylation enables near-instantaneous Golgi imaging. Replacing fluorophore with a biphenyl motif promotes CyMA accumulation and disrupts functions such as protein modifications, trafficking, and secretion, leading to cell death. This study establishes dynamic supramolecular assembly as an active and selective strategy for Golgi-targeting, pleiotropically interfering with Golgi functions, which may be applicable to targeting other organelles by utilizing alternative enzyme switches to enable kinetic trapping. Tan and colleagues present “cycling molecular assemblies” that borrow cellular lipidation machinery to build nanostructures inside the Golgi apparatus. These tools enable rapid organelle imaging and selective destruction of cancer cells.

Abstract Treatment emergent neuroendocrine prostate cancer (t-NEPC) is a highly aggressive subtype of castration resistant prostate cancer (CRPC) with rapid progression and a very limited therapeutic arsenal. Clinical outcomes remain poor, and new treatment strategies with clear translational potential are urgently needed. Analyses of publicly available prostate cancer datasets showed that high PTPN1 expression is strongly associated with poor recurrence free survival in metastatic disease, suggesting that PTPN1 may serve as a clinically relevant molecular determinant of aggressive prostate cancer. We found that PTPN1 promotes t-NEPC progression and discovered a reciprocal interaction between PTPN1 and the androgen receptor and the RE1 silencing transcription factor (REST) repressor complex. This interaction represents a key regulatory mechanism driving the trans differentiation of androgen receptor positive CRPC into t-NEPC. Through CRISPR mediated PTPN1 knockout, PTPN1 cDNA overexpression, and pharmacologic inhibition in prostate cancer cells, we demonstrated that PTPN1 modulates neuroendocrine lineage plasticity. PTPN1 inhibition reduced neuroendocrine features and restored responses to anti androgen therapy in both in vitro and in vivo models. The therapeutic efficacy observed with PTPN1 inhibition highlights its translational potential as a druggable target for patients with t-NEPC, a population with urgent unmet clinical needs. These findings support further development of PTPN1 directed therapies and provide a strong rationale for future clinical investigation. Citation Format: Yu-An Chen, Mickey Glover, Rey-Chen Pong, Payal Kapur, Jer-Tsong Hsieh. PTPN1 activates neuroendocrine of treatment emergent prostate cancer by targeting the AR and REST complex [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 321.

INTRODUCTION:Androgens and androgen receptor (AR) signaling may play a role in lung cancer pathophysiology. Patients with benign prostatic hyperplasia (BPH) may represent a population with relatively lower androgen levels, and AR signaling can be inhibited through androgen pathway manipulation (APM). OBJECTIVES:This study aimed to evaluate the impact of BPH and APM on survival outcomes in lung cancer patients. METHODS:A total of 4,742 male lung cancer patients diagnosed between 2006 and 2021 were retrospectively analyzed. APM exposure referred to treatment with antiandrogens, 5-alpha reductase inhibitors, or gonadotropin-releasing hormone modulators for 30 days or longer post lung cancer diagnosis. Experimental validation was carried out using cultured A549 cells and a xenograft model in BALB/c nude mice. RESULTS:Among the enrolled patients, 1,219 (25.7%) had BPH, and 121 (2.6%) were exposed to APM. Multivariable Cox analysis showed that both BPH (aHR 0.72) and APM exposure (aHR 0.63) were independently associated with improved overall survival (both p < 0.001). The in vitro study demonstrated that AR was involved in A549 cell proliferation, and that AR inhibition with finasteride decreased AR protein levels and markedly inhibited A549 cell growth. Mechanistically, finasteride promoted AR protein ubiquitination and degradation, thereby destabilizing AR protein, further inhibiting cell cycle progression, and inducing apoptosis in A549 cells. In addition, the in vivo results corroborated finasteride's inhibitory effect on lung cancer growth. CONCLUSIONS:These findings suggest that both BPH and APM exposure were associated with improved survival in male patients with lung cancer. Finasteride disruption of AR stability might subsequently inhibit A549 lung cancer cell growth. Overall, these results highlight the potential therapeutic value of targeting androgen and AR signaling in lung cancer treatment.

Nectin-4-targeted imaging has emerged as a promising strategy for patient stratification in urothelial carcinoma, yet currently available radiotracers remain limited by rapid renal clearance, urinary background activity, or potential pharmacologic confounding associated with antibody-drug conjugate (ADC)-based constructs. To overcome some of these limitations, we developed a payload-free immunoPET radiotracer based on the native enfortumab antibody conjugated with the bifunctional chelator DFO*-sq and radiolabeled with zirconium-89 (89Zr). The resulting [89Zr]Zr-DFO*-sq-Enfortumab preserved Nectin-4-specific targeting while demonstrating high radiochemical stability in human serum (>99% through Day 12). In vitro studies showed efficient antigen-specific cellular internalization (80-85%), prolonged intracellular retention, and evidence consistent with partial recycling of antibody-associated species. In vivo, [89Zr]Zr-DFO*-sq-Enfortumab exhibited sustained tumor uptake reaching 17.4 ± 2.8% ID/g in high Nectin-4-expressing xenografts and correlated with differential Nectin-4 expression across multiple bladder cancer models. Importantly, the full-length antibody platform enabled high-contrast visualization of pulmonary metastatic lesions and orthotopic bladder tumors despite some urinary background activity. Together, these findings demonstrate that payload-free [89Zr]Zr-DFO*-sq-Enfortumab provides a biologically relevant immunoPET platform for noninvasive assessment of variable Nectin-4 expression and support its further evaluation as a companion imaging strategy for Enfortumab Vedotin-based therapies.

Aberrant PI3K/Akt activation is linked to prostate cancer (PCa) malignancy, while androgen receptor (AR) is critical in early-stage PCa development. Investigating the interaction between these pathways is crucial for PCa malignancy. Our previous study demonstrated that p35-CDK5 mediates post-translational modifications of AR, STAT3, and p21CIP1, eventually promoting PCa cell growth. This study revealed the role of p35-CDK5 in between PI3K/Akt and AR by utilizing LNCaP and 22Rv1 cells. Through the TCGA database analysis, we observed a positive correlation between PTEN and p35 expression, implying a potential negative correlation between PI3K/Akt activation and p35-CDK5. Inhibiting PI3K/Akt with LY294002, Capivasertib (AZD5363), or using an inactive Akt mutant significantly increased p35 expression and subsequently enhanced AR stability and activation in PCa cells. On the other hand, CDK5-knockdown reversed these effects. The involvement of the β-catenin/Egr1-axis was observed in regulating PI3K/Akt inhibition and p35-CDK5 activation, implying a possible mechanistic connection. Importantly, CDK5 knockdown further reduced PI3K/Akt-inhibition-induced AR and cell viability maintenance, suggesting a compensatory role for CDK5-AR in maintaining cell viability under Akt inhibition. In conclusion, PI3K/Akt inhibition could trigger p35-CDK5-dependent AR activation and cell viability, highlighting p35-CDK5 as a critical link connecting PI3K/Akt inhibition to AR activation and pivotal in PCa cell resistance to PI3K/Akt blockade.

The Golgi apparatus is a critical organelle responsible for intracellular trafficking and signaling, orchestrating essential processes such as protein and lipid sorting 1-5 . Dysregulation of its function has been implicated in various pathologies, including obesity, diabetes, and cancer, highlighting its importance as a potential therapeutic target. Despite this, the development of tools to selectively target the Golgi in specific cell types remain a significant unmet challenge in imaging and drug discovery. Golgi-specific enzyme activities, such as those mediated by protein acyltransferases and thioesterases 6 , offer an untapped opportunity to develop subcellularly localized therapeutics. Current approaches predominantly rely on direct protein binding but lack the necessary cell selectivity 7 , underscoring the unmet need for innovative strategies to selectively disrupt Golgi function in cancer cells. Here, we report the development of cycling molecular assemblies (CyMA), a novel class of small peptide derivatives (e.g., dipeptides), which exploit the unique enzymatic environment of the Golgi to establish futile cycles of reversible S-acylation. These assemblies selectively accumulate in cancer cell Golgi, interfering with protein S-acylation cycles and disrupting organelle homeostasis. CyMA impair key Golgi functions, including protein trafficking, glycosylation, and secretion, while demonstrating selective sparing hepatocytes and immune cells such as M1 macrophages. This selective activity represents a paradigm shift, utilizing an enzyme switch and leveraging intracellular environment rather than direct protein binding. Unlike conventional approaches, CyMA reduce tumor growth, drug resistance, and metastasis by pleiotropically disrupting Golgi related functions. By demonstrating the potential of futile cycles as a therapeutic strategy 8 , this study introduces a generalizable method for targeting organelle-specific enzyme activities. These findings not only underscore the therapeutic potential of CyMA in cancer but also pave the way for future applications in other Golgi-associated diseases.

OBJECTIVE:Partitioning defective protein 3 (Par3) has recently been found to have important roles in cancer progression. Interestingly, Par3's functions vary among cancers: both Par3 elevation (in the prostate or liver) and loss (in the breast or lung) have been implicated in cancer metastasis. Although Par3 overexpression has been correlated with diminished survival in renal cell carcinoma (RCC), data indicating the role of Par3 in RCC metastasis are lacking. Given reports of interactions between Par3 and oncoproteins such as Yes-associated protein (YAP)/WW domain-containing transcription regulator 1 (TAZ), we investigated whether Par3-mediated RCC metastasis might be due to activation of the Hippo pathway components YAP and TAZ. METHODS:Par3 levels were analyzed in RCC cell lines and human RCC patient tissues by western blotting and immunohistochemical (IHC) staining, as appropriate. Co-immunoprecipitation (co-IP) and immunofluorescence studies were conducted to examine the interaction between Par3 and YAP. Quantitative PCR and luciferase assays were used to investigate the effects of Par3 on YAP target gene expression and co-transcriptional regulation. PDZ domain deletion mutants of Par3 were generated to elucidate the structural basis of the interaction between Par3 and YAP. RESULTS:Higher Par3 levels were found in distant-organ-RCC-metastasis-derived ACHN sublines than wild type ACHN cell lines. Par3 levels were also higher in the patient tissue obtained from metastatic sites than in normal kidney and primary RCC tumor tissues. Co-IP and IHC experiments demonstrated that Par3 directly interacted and co-localized with YAP/TAZ proteins. Moreover, Par3 upregulated the transcription of YAP/TAZ downstream target genes and increased the luciferase activity of YAP/TAZ responsive elements. PDZ domain 3 in the PARD3 gene was demonstrated to be particularly important in the interactions between Par3 and YAP. Furthermore, Par3 was found to upregulate intracellular levels of YAP/TAZ molecules and promote nuclear translocation of YAP. CONCLUSIONS:Together, these results indicate the role of Par3 in RCC metastasis, via driving metastatic RCC progression by promoting the YAP/TAZ pathway.

Partitioning defective protein 3 (Par3) has recently been found to have important roles in cancer progression. Interestingly, Par3's functions vary among cancers: both Par3 elevation (in the prostate or liver) and loss (in the breast or lung) have been implicated in cancer metastasis. Although Par3 overexpression has been correlated with diminished survival in renal cell carcinoma (RCC), data indicating the role of Par3 in RCC metastasis are lacking. Given reports of interactions between Par3 and oncoproteins such as Yes-associated protein (YAP)/WW domain-containing transcription regulator 1 (TAZ), we investigated whether Par3-mediated RCC metastasis might be due to activation of the Hippo pathway components YAP and TAZ. Par3 levels were analyzed in RCC cell lines and human RCC patient tissues by western blotting and immunohistochemical (IHC) staining, as appropriate. Co-immunoprecipitation (co-IP) and immunofluorescence studies were conducted to examine the interaction between Par3 and YAP. Quantitative PCR and luciferase assays were used to investigate the effects of Par3 on YAP target gene expression and co-transcriptional regulation. PDZ domain deletion mutants of Par3 were generated to elucidate the structural basis of the interaction between Par3 and YAP. Higher Par3 levels were found in distant-organ-RCC-metastasis-derived ACHN sublines than wild type ACHN cell lines. Par3 levels were also higher in the patient tissue obtained from metastatic sites than in normal kidney and primary RCC tumor tissues. Co-IP and IHC experiments demonstrated that Par3 directly interacted and co-localized with YAP/TAZ proteins. Moreover, Par3 upregulated the transcription of YAP/TAZ downstream target genes and increased the luciferase activity of YAP/TAZ responsive elements. PDZ domain 3 in the PARD3 gene was demonstrated to be particularly important in the interactions between Par3 and YAP. Furthermore, Par3 was found to upregulate intracellular levels of YAP/TAZ molecules and promote nuclear translocation of YAP. Together, these results indicate the role of Par3 in RCC metastasis, via driving metastatic RCC progression by promoting the YAP/TAZ pathway.

Renal function biomarkers such as serum blood urea nitrogen (BUN) and creatinine (Cr) serve as key indicators for guiding clinical decisions before administering kidney-excreted small-molecule agents. With engineered nanoparticles increasingly designed to be renally clearable to expedite their clinical translation, understanding the relationship between renal function biomarkers and nanoparticle transport in diseased kidneys becomes crucial to their biosafety in future clinical applications. In this study, renal-clearable gold nanoparticles (AuNPs) are used as X-ray contrast agents to noninvasively track their transport and retention in cisplatin-injured kidneys with varying BUN and Cr levels. The findings reveal that AuNP transport is significantly slowed in the medulla of severely injured kidneys, with BUN and Cr levels elevated to 10 times normal. In mildly injured kidneys, where BUN and Cr levels only four to five times higher than normal, AuNP transport and retention are not predictable by BUN and Cr levels but correlate strongly with the degree of tubular injury due to the formation of gold-protein casts in the Henle's loop of the medulla. These results underscore the need for caution when employing renal-clearable nanomedicines in compromised kidneys and highlight the potential of renal-clearable AuNPs as X-ray probes for assessing kidney injuries noninvasively.

Targeting immunosuppressive metastatic cancer cells is a key challenge in therapy. We recently have shown that a rigid-rod aromatic, pBP-NBD, that responds to enzymes and kill immunosuppressive metastatic osteosarcoma (mOS) and castration resistant prostate cancer (CRPC) cells in mimetic bone microenvironment. However, pBP-NBD demonstrated moderate efficacy against CRPC cells. To enhance activity, we incorporated the unnatural amino acid L- or D-4,4 '-biphenylalanine (L- or D-BiP) into pBP-NBD, drastically increasing cellular uptake and CRPC inhibition. Specifically, we inserted BiP into pBP-NBD to target mOS (Saos2 and SJSA1) and CRPC (VCaP and PC3) cells with overexpressed phosphatases. Our results show that the D-peptide backbone with an aspartate methyl diester at the C-terminal offers the highest activity against these immunosuppressive mOS and CRPC cells. Importantly, imaging shows that the peptide assemblies almost instantly enter the cells and accumulate primarily within the endoplasmic reticulum of Saos2, SJSA1, and PC3 cells and at the lysosomes of VCaP cells. By using BiP to boost cellular uptake and self-assembly within cancer cells, this work illustrates an unnatural hydrophobic amino acid as a versatile and effective residue to boost endocytosis of synthetic peptides for intracellular self-assembly. This research demonstrates that the integration of unnatural amino acids (L- or D-4,4 '-biphenylalanine) into peptide assemblies significantly accelerates their accumulation within prostate cancer cells, boosting their capacity to hinder cancer proliferation. This work paves a way for engineering supramolecular medicine, potentially heightening the efficacy of peptide-based treatments for prostate cancer. It may lead to more effective therapeutic strategies for treating other cancers. image

SPHK1 (sphingosine kinase type 1) is characterized as a rate-limiting enzyme in sphingolipid metabolism to phosphorylate sphingosine into sphingosine-1-phosphate (S1P) that can bind to S1P receptors (S1PRs) to initiate several signal transductions leading to cell proliferation and survival of normal cell. Many studies have indicated that SPHK1 is involved in several types of cancer development, however, a little is known in bladder cancer. The TCGA database analysis was utilized for analyzing the clinical relevance of SPHK1 in bladder cancer. Through CRISPR/Cas9 knockout (KO) and constitutive activation (CA) strategies on SPHK1 in the bladder cancer cells, we demonstrated the potential downstream target could be programmed cell death 1 ligand 2 (PD-L2). On the other hand, we demonstrated that FDA-approved SPHK1 inhibitor Gilenya® (FTY720) can successfully suppress bladder cancer metastasis by in vitro and in vivo approaches. This finding indicated that SPHK1 as a potent therapeutic target for metastatic bladder cancer by dissecting the mechanism of action, SPHK1/S1P-elicited Akt/β-catenin activation promoted the induction of PD-L2 that is a downstream effector in facilitating bladder cancer invasion and migration. Notably, PD-L2 interacted with c-Src that further activates FAK. Here, we unveil the clinical relevance of SPHK1 in bladder cancer progression and the driver role in bladder cancer metastasis. Moreover, we demonstrated the inhibitory effect of FDA-approved SPHK1 inhibitor FTY720 on bladder cancer metastasis from both in vitro and in vivo models.

Background/Aim: Bladder cancer remains a significant global health concern, necessitating a deeper understanding of the molecular mechanisms underlying its progression. Cyclin-Dependent Kinase 5 (CDK5) has recently emerged as a potential player in bladder cancer pathogenesis. This study investigated the involvement of CDK5 in bladder cancer, emphasizing its potential as a therapeutic target. Materials and Methods: The expression levels of CDK5 and p35 (CDK5 regulatory protein) and their roles in the tumor grade and malignancy of patient samples were evaluated using western blot analysis and immunohistochemistry. In addition, tumor cancer genome atlas (TCGA) was utilized to evaluate survival rate in patients with bladder cancer. We further confirmed the role of CDK5 with in vitro experiments using western blot analysis, immunocytochemistry, cell culture-based proliferation and migration assays. Results: Higher CDK5 and p35 were associated with a higher tumor grade and poor survival rate in patients with bladder cancer. To confirm the role of CDK5 in vitro, we over-expressed CDK5 in bladder cancer cells. The results showed that the over-expression of CDK5 enhanced bladder cancer cell proliferation and migration. In addition, CDK5 inhibition by a pan-CDK inhibitor, Roscovitine (RV), significantly reduced proliferation of bladder cancer cells. Indeed, the migration and adhesion of bladder cancer cells were inhibited by RV treatment. Conclusion: CDK5 might play important roles in bladder cancer progression and be a potential diagnostic and therapeutic target in the near future.