Search Results (1,196)

Neuroendocrine prostate cancer (NEPC) is characterized by androgen receptor (AR) independence and poor response to conventional therapies, highlighting the need to unveil the molecular mechanisms behind NEPC. We previously showed that heme oxygenase 1 (HO-1, encoded by HMOX1) translocates to the nucleus exerting unexplored non-canonical functions. The present study delineates the nuclear interactome of HO-1, revealing a potential mechanism that impairs NEPC establishment. Through a proteomics approach integrated with bioinformatics analyses, we identified eleven novel nuclear interactors of HO-1. Unsupervised clustering analyses of RNA-seq data from prostate cancer (PCa) patient-derived xenografts (MDA PCa PDXs) and clinical cohorts demonstrated high expression of three HO-1 interactors (ILF3, SAFB, BCLAF1, and DDX17) in NEPC samples, with concomitant HMOX1 under-expression. Spatial transcriptomics in a mixed-histology tumor confirmed enrichment of the interactors in the NEPC foci. To better understand the link between HO-1 and NEPC, we established and characterized an in vitro model of NE transdifferentiation in PCa cell lines using forskolin to induce phenotypic reprogramming. HO-1 upregulation in transdifferentiated cells significantly attenuated the expression of NE markers and triggered a morphological shift, restoring epithelial phenotypes. This work identifies for the first time HO-1 nuclear interactome association with NEPC, where the HMOX1-ILF3-SAFB-BCLAF1-DDX17 print emerges as a useful marker for disease stratification. Full article

Anti-CD226 antibody-mediated stimulation of NK-92 cells (sNK-92) represents a potential immunotherapeutic approach; however, its cytotoxic and apoptosis-associated effects in hormone-independent solid tumors remain insufficiently characterized. This study investigated the activity of sNK-92 cells against PC3 castration-resistant prostate cancer and SH-SY5Y neuroblastoma cell lines, using PNT1A normal prostate epithelial and BJ normal dermal fibroblast cells as non-malignant controls. Cytotoxicity was assessed by CCK-8 assay at target-to-effector (T:E) ratios of 1:1, 1:5, and 1:10, and markers historically associated with the intrinsic (BAX, caspase-9), extrinsic (caspase-8), and executioner (caspase-3) apoptotic pathways were evaluated quantitatively by ImageJ-based corrected total cell fluorescence (CTCF) analysis. sNK-92 cells produced significant ratio-dependent cytotoxicity against PC3 and SH-SY5Y cells, reaching 23.76% and 26.29%, respectively, at the 1:10 T:E ratio, with sNK-92 producing significantly greater cytotoxicity than unstimulated NK-92 at this ratio in both cell lines and additionally at the 1:5 ratio in SH-SY5Y cells; no significant reduction in CCK-8 viability was detected in PNT1A or BJ cells at any ratio. Quantitative immunofluorescence analysis demonstrated substantially increased relative fluorescence intensity of all four apoptosis-associated markers in sNK-92-treated PC3 and SH-SY5Y cells compared with their corresponding controls and, in most comparisons, with NK-92-treated cells, whereas changes observed in the PNT1A and BJ non-malignant models examined were markedly smaller. These findings provide preliminary quantitative evidence that anti-CD226-stimulated NK-92 cells exert a preferential cytotoxic effect on the tumor cell models examined, relative to the non-malignant models tested, and induce changes in apoptosis-associated markers consistent with engagement of apoptotic signaling. Further orthogonal validation is warranted. Full article

Enhydrin, a melampolide-type sesquiterpene lactone abundant in the leaves of yacon (Smallanthus sonchifolius), has not previously been investigated for its anti-prostate cancer activity. This study investigated the antiproliferative effects of enhydrin in human prostate cancer cells, its regulatory effects on apoptosis-related molecules, and its impact on the PI3K/AKT and NF-κB signaling pathways. Three prostate cancer cell lines (PC3, DU145, and LNCaP) were treated with enhydrin, and its effects were analyzed using cell viability assays, morphological observation, flow cytometry, apoptosis-focused TaqMan qPCR array, qRT-PCR, and Western blotting. In vivo antitumor activity was assessed in a PC3 xenograft mouse model. Enhydrin reduced cell viability in a dose- and time-dependent manner, induced morphological changes associated with cytotoxicity, and caused G1 cell-cycle arrest. Gene expression analysis revealed downregulation of PI3K/AKT- and NF-κB-related genes and modulation of BCL2 family genes toward a pro-apoptotic profile, which was confirmed at both mRNA and protein levels. In vivo, enhydrin suppressed tumor growth without significant body-weight loss. These findings suggest that enhydrin exerts antitumor effects in prostate cancer by reducing the expression of PI3K/AKT and NF-κB related molecules and modulating apoptosis-related proteins. Although additional studies are required to determine pathway activity, directly confirm apoptosis, and evaluate normal-cell cytotoxicity and the therapeutic window, these findings provide preliminary biological evidence of the effects of enhydrin in prostate cancer models. Full article

Background: Homeobox transcription factors regulate developmental programs, cellular plasticity, and tumor progression, yet the role of H2.0-like homeobox (HLX) in prostate cancer (PCa) remains poorly defined. We investigated the clinical significance of HLX and its relationship to the pro-metastatic transcription factor TBX2. Methods: Transcriptomic and clinical datasets from TCGA, MET500, and SU2C/PCF cohorts were analyzed to assess HLX expression, clinicopathologic associations, and its relationship with TBX2. Functional studies in human PCa cell lines included TBX2 gain- and loss-of-function, HLX knockdown, chromatin immunoprecipitation (ChIP), and expression analyses. Shared HLX- and TBX2-associated pathways were evaluated by Reactome enrichment analysis, and Hallmark Gene Set Enrichment Analysis compared castration-resistant prostate cancer (CRPC) bone metastases with high versus low HLX expression (GSE77930; n = 5/group). In vivo relevance was assessed in an orthotopic TBX2 dominant-negative PCa xenograft model. Results: Human PCa datasets showed that HLX expression was elevated in PCa versus normal prostate tissue and associated with higher Gleason grade, lymph node involvement, aggressive molecular subtypes, and shorter disease-free survival. HLX expression also positively correlated with TBX2 across human PCa cohorts. HLX- and TBX2-associated transcriptional programs converged on extracellular matrix organization, cell adhesion, NOTCH, and VEGF-MAPK signaling pathways. Furthermore, HLX-high CRPC bone metastases were enriched for epithelial–mesenchymal transition, NOTCH, TGF-β, inflammatory, angiogenic, hypoxic, and KRAS signaling pathways. Mechanistic studies showed that HLX knockdown suppressed extracellular matrix-associated genes and key NOTCH pathway components. ChIP demonstrated direct TBX2 binding to the HLX promoter, and genetic modulation of TBX2 expression established HLX as a downstream target of TBX2. Consistent with these findings, reduced HLX expression in orthotopic TBX2 dominant-negative xenografts was associated with loss of metastatic progression. Conclusions: HLX is a candidate biomarker of aggressive PCa and a direct transcriptional target of TBX2. These findings identify a previously unrecognized TBX2–HLX regulatory axis associated with metastatic transcriptional programs and aggressive disease in advanced PCa. Full article

Preclinical models play a critical role in the development of PSMA-targeted radiopharmaceuticals for prostate cancer. However, many existing models have practical limitations, including slow tumor growth, low engraftment rates, and restricted availability, and all human PSMA-positive lines are confined to immunodeficient hosts. We developed and characterized a novel PSMA-expressing transgenic cell line, CT26-PSMA, as a practical tool for preclinical screening of PSMA-targeting agents. The CT26-PSMA cell line was established by stable transfection of the murine colon carcinoma CT26 cell line with human PSMA using the Sleeping Beauty transposon system. PSMA expression was confirmed by RT-qPCR (reverse transcription quantitative polymerase chain reaction), flow cytometry, and radioligand saturation binding on intact cells. Two [⁶⁸Ga]Ga-labeled radioconjugates—the well-established PSMA-617 and a newly synthesized conjugate (Conjugate-1)—were used to validate the functionality of the model through in vitro binding, uptake and internalization studies, and through ex vivo biodistribution in CT26-PSMA tumor-bearing athymic male nu/nu mice. The CT26-PSMA cell line demonstrated high and stable PSMA expression, with approximately 95% of cells expressing the biomarker and no measurable loss over 16 passages in antibiotic-free medium. Saturation binding gave a receptor density of ∼3.5 × 10⁶ sites per cell, approximately four-fold higher than that of LNCaP cells (∼0.8 × 10⁶), with dissociation constants that were indistinguishable between the two radioconjugates and between the two cell lines (K_d 9.0–11.6 nM). Subcutaneous tumors reached ~300 mm³ within 8–10 days of inoculation, with a take rate of 10/10 versus 1/10 for LNCaP (Fisher’s exact test, p = 1.2 × 10⁻⁴). Both radiotracers showed saturable, 2-PMPA-blockable binding and uptake in CT26-PSMA cells, confirming the functional activity of the recombinant receptor. Biodistribution studies revealed accumulation of both conjugates in CT26-PSMA tumors, with generally comparable tumor-to-background profiles. The CT26-PSMA cell line represents a robust, rapid, and reproducible platform for preclinical evaluation of PSMA-targeting radiopharmaceuticals, and its murine BALB/c origin permits engraftment in immunocompetent or minimally immunosuppressed hosts, whereas existing human PSMA-positive lines do not. It is intended as a screening platform rather than as a model of prostate cancer biology. The validation data obtained with [⁶⁸Ga]Ga-labelled conjugates confirm the suitability of this cell line for future studies of PSMA-directed compounds. Full article

Background/Objectives: High linear energy transfer (LET) carbon ions achieved more effective and biologically robust tumor control than photons in preclinical prostate cancer models; however, the longitudinal development of histopathological parameters remains insufficiently characterized, limiting the selection of the optimal treatment modality in patients. This study analyzed the temporal histological patterns after isoeffective photon, proton, and carbon ion irradiations. Methods: Two Dunning R3327 prostate carcinoma sublines (H, HI) grown subcutaneously in male Copenhagen rats received single-fraction isoeffective curative photon or carbon ion doses. For HI-tumors, the effectiveness of isoeffective curative proton doses and isoeffective subcurative photon and carbon ion doses was additionally investigated. Tumors were collected prior and up to 3 weeks after irradiation and processed for quantitative histology of proliferation (BrdU), DNA damage (γH2AX), hypoxia (pimonidazole), vascular (CD31), and immune cell (CD3, CD68) markers. Results: All modalities induced an early peak in γH2AX⁺ tumor cells and a pronounced suppression of BrdU⁺ cells, with more sustained effects after isoeffective carbon ions doses, particularly in the HI-tumors. These findings, however, differed strongly between hypoxic and oxic micro-environments. Vascular parameters, diffusion distances, and global and compartment-specific hypoxic fractions showed distinct temporal dynamics between photons and carbon ions in HI-tumors, whereas H-tumors exhibited more moderate and reversible changes. At curative carbon ion doses, there was a late rebound of BrdU-positive tumor cells and increased CD68⁺ macrophage accumulation in chronically hypoxic regions. CD3⁺ T cells showed a biphasic decrease-recovery pattern in HI-tumors largely independent of radiation quality and oxygenation. Conclusions: Longitudinal histology revealed modality- and tumor-line-specific trajectories of tumor, vascular, hypoxic, and immune responses after isoeffective photon, proton, and carbon ion irradiations in prostate carcinoma. The more persistent tumor cell damage and distinct vascular response, together with late proliferative and macrophage rebounds under chronic hypoxia after carbon ions, provide mechanistic support for the increased biological effectiveness and highlight hypoxia-driven repopulation and inflammation as key processes. Full article

Background/Objectives: Advanced prostate cancer remains difficult to treat because docetaxel, although clinically important, is limited by systemic toxicity, poor tumor selectivity, and acquired resistance. Camptothecin is a potent anticancer agent, but its clinical application is restricted by poor solubility and instability. This study investigated the synergy between docetaxel and camptothecin and developed transferrin-conjugated, camptothecin-bearing dendrimersomes entrapping docetaxel as a targeted nanocarrier for prostate cancer therapy. Methods: Drug synergy was evaluated in PC3-Luc cells using an MTT assay and combination index analysis. Transferrin-conjugated, disulfide-linked camptothecin-bearing PEGylated DAB dendrimers were synthesized and characterized by ¹H-NMR, critical aggregation concentration analysis, transmission electron microscopy, and entrapment efficiency measurements. pH- and redox-dependent drug release was assessed by dialysis. Cellular uptake and uptake mechanisms were investigated by confocal microscopy, flow cytometry, and inhibitor studies in PC3-Luc, DU145, and LNCaP cells. Anti-proliferative efficacy was determined by an MTT assay. Results: Docetaxel and camptothecin showed marked synergy in PC3-Luc cells, with a minimum combination index of 0.20 ± 0.01 and 88.10 ± 0.41% growth inhibition at low nanomolar concentrations. Transferrin-conjugated dendrimersomes self-assembled into spherical vesicles with a critical aggregation concentration of approximately 250 µg/mL. They had high docetaxel entrapment efficiency (89.10 ± 0.08%) and enhanced drug release under acidic and reductive conditions. They significantly increased cellular uptake of docetaxel relative to non-targeted dendrimersomes (by up to 3-fold) and free drugs (by up to 20-fold), mainly through transferrin receptor-mediated endocytosis, and improved anti-proliferative activity in all three cell lines. Tf-conjugated DPSSC produced the lowest IC₅₀ values among the tested formulations: 11.72 ± 1.02 nM in PC3-Luc, 9.88 ± 1.22 nM in DU145, and 7.88 ± 1.35 nM in LNCaP cells. Conclusions: Transferrin-conjugated camptothecin-based dendrimersomes entrapping docetaxel represent a promising multifunctional nanocarrier for prostate cancer that combines synergistic dual-drug therapy, active targeting, and stimulus-responsive release, supporting further evaluation as a selective delivery strategy in advanced prostate cancer using preclinical models and in vivo studies. Full article

Long-established prostate cancer cell lines provide limited insight into how contemporary early prostate cancer evolves into drug-resistant and neuroendocrine-like refractory disease. Patient-derived three-dimensional (3D) ex vivo models may better preserve this transition. Here, we found that 8 of 10 magnetic resonance imaging-guided biopsy specimens from patients with early-stage prostate cancer generated sustained 3D tumor spheroid cultures. After 12 weeks of enzalutamide selection, only one patient-derived culture acquired a resistant phenotype with treatment-emergent neuroendocrine prostate cancer (t-NEPC)-like features, including increased chromogranin A (CgA) and synaptophysin (SYP); reduced androgen receptor (AR), prostate-specific antigen (PSA), and prostate-specific membrane antigen (PSMA); and conversion from compact spheroids into irregular resistant aggregates. During this transition, WD repeat and SOCS box-containing protein 1 (WSB1) increased, whereas PSMA progressively decreased. WSB1 silencing restored PSMA, AR, and PSA expression and reduced neuroendocrine-associated features. A similar WSB1 dependency was observed in enzalutamide-resistant LNCaP cells, the castration-resistant prostate cancer model 22Rv1, and the neuroendocrine/small-cell prostate cancer model NCI-H660. Mechanistically, WSB1 functioned as a SOCS box-dependent E3 ubiquitin ligase adaptor that promoted PSMA ubiquitination and degradation. SOCS box deletion or T380A mutation impaired this process, while Aurora kinase A (AURKA) inhibition reduced WSB1-dependent PSMA ubiquitination. WSB1 depletion, AURKA inhibition with alisertib, and combined AURKA inhibition with EZH2 suppression reduced resistant aggregate growth and increased apoptosis-associated markers in patient-derived enzalutamide-resistant neuroendocrine-like spheroids and related models. These findings nominate the AURKA–WSB1–PSMA axis as a therapeutic vulnerability in refractory prostate cancer. Full article

Background/Objectives: Prostate cancer (PC) exhibits marked disparities in incidence and mortality across ethnicities, with men of Sub-Saharan African (SSA) ancestry experiencing 1.7 and 2.0 times higher values, respectively, than European men (EUR). However, SSA preclinical models remain scarce (just one commercial cell line). In this study, we established and characterized a novel panel of PC cell lines derived from SSA patients using conditional reprogramming (CR), a method that enables efficient propagation of primary cells while maintaining their genotypic and phenotypic features. Methods: CR was applied to five SSA-PC samples, and successfully propagated samples were authenticated by STR and ~1 million SNP profiling, and extensively characterized for proliferative capacity, migratory behaviour, karyotyping and epithelial and prostate tumour lineage markers. To explore drug response profiles, a high-throughput screen (HTS) of 1280 clinically annotated compounds was conducted. Results: Three SSA-PC cell lines were successfully established and authenticated, and five potential drug hits were validated. A new finding was the reduced sensitivity of SSA-derived models (9.0 times difference compared to commercial EUR PC cell lines) to camptothecin, a TOP1 inhibitor, while being equally sensitive to epirubicin hydrochloride, a TOP2 inhibitor. The cardiac glycoside digoxin, anthelmintic pyrvinium pamoate and antirheumatic agent auranofin were also efficient drugs in the in vitro testing. Conclusions: These results support the relevance of SSA-derived PC models for preclinical drug screening and highlight the value of including ancestry-diverse models in oncobiology research. Full article

ZnO nanoparticles (ZnO NPs) have been widely investigated in the biomedical field, particularly their anti-tumor efficacy. The potential of ZnO hierarchical structures (ZnO HSs) in tumor cell eradication remains largely unexplored in prostate cancer (PCa) and thyroid cancer (TC). In this study, we successfully synthesized and characterized ZnO NPs and ZnO HSs using green tea extract (Camellia sinensis) as a reducing agent and conjugation of FIT-C tracking for both ZnO NPs and ZnO HSs. UV-vis spectrophotometry, Dynamic Light Scattering (DLS), FTIR, XDR, SEM and TEM revealed significant differences in morphology between ZnO NPs and ZnO HSs. Our in vitro experiments demonstrated that SNPs were more effective on aggressive PCa and TC cell lines compared to ZnO NPs. Notably, ZnO HSs exhibited enhanced cytotoxicity in 3D tumor cell spheroid models. Mechanistically, ZnO HSs induced apoptosis through cholesterol-mediated reactive oxygen species (ROS) generation. Our in vivo study revealed no histopathological changes in major organs (liver, kidneys, spleen and lungs), emphasizing the safe administration of both ZnO NPs and ZnO HSs. Our study synthesized FITC-conjugated non-spherical ZnO nanoparticles, providing evidence for a novel treatment strategy for hormone-related cancers and prospective fluorescent-guided nanomedicine. Full article

Background/Objectives: Poor aqueous solubility and low bioavailability limit the therapeutic use of many hydrophobic anticancer agents. This study developed liposomal and polymeric micellar formulations of a fluorinated curcumin derivative (FCur) and naringenin (NG), prepared as single-compound and mixed systems, and compared their physicochemical and biological properties. Methods: Soluplus^®-based polymeric micelles and POPC:DOTAP liposomes were prepared by the thin-film hydration method and characterised using dynamic light scattering (DLS), zeta potential measurements, HPLC, NMR relaxation studies, and in vitro cytotoxicity assays. Results: Polymeric micelles formed homogeneous dispersions with particle sizes below 95 nm and a slightly negative zeta potential (~−3 mV), whereas liposomes were larger (>130 nm) and strongly positively charged (>+40 mV). Both systems achieved high encapsulation efficiencies (>72% for FCur and >95% for NG). NMR relaxation studies revealed more restricted molecular dynamics within liposomal bilayers and greater motional freedom in micelles. In biological studies, FCur and mixed liposomes exhibited the highest overall cytotoxicity against bladder (5637), prostate (LNCaP) cancer as well as normal fibroblast (MRC-5) cell lines, compared with the free compounds and polymeric micelles. Notably, polymeric micelles with FCur (single and mixed) exhibited a more favourable differential cytotoxicity response between bladder cancer and normal cells. Conclusions: These findings demonstrate that the nanocarrier system plays a critical role in determining both molecular dynamics and biological performance of encapsulated agents. Full article

Background/Objectives: Though PARP inhibition has improved the management of advanced prostate cancer, patient outcomes may be modest and disease progression on treatment is common. We sought to improve understanding of tumor cell response to PARP inhibition to support development of novel strategies to enhance and/or prolong PARP inhibitor (PARPi) efficacy. Methods: Cell viability assays and microscopy were used for initial characterization of PARPi response in models of advanced prostate cancer. RNA sequencing was performed to investigate time-dependent transcriptomic changes induced by PARP inhibition. Western blots, flow cytometry, and both additional viability assays and microscopy were used to validate RNA sequencing results and test potential therapeutic strategies. Results: Characterization of responses to PARP inhibition reveals time-dependent changes which may be targeted to improve treatment efficacy. In line with the expected PARPi mechanism of action, short-term treatment is largely associated with activation of ATM and the DNA damage response and cell cycle checkpoint signaling. Targeting ATM with clinical stage inhibitors significantly enhances reduction of tumor cell viability by PARP inhibition. Tumor cells exposed to longer-term treatment exhibit SLUG-dependent epithelial–mesenchymal transition (EMT) and evidence for altered fatty acid metabolism, both of which may be targeted to enhance PARPi anti-tumor cell effects. Conclusions: This study provides insight into both short and longer-term cellular response to PARPi treatment and provides a foundation for additional efforts to explore effective strategies to maximize the utility of PARP inhibition for managing prostate cancer. Full article

Prostate cancer remains a major cause of cancer-related mortality, and new therapeutic strategies are needed for advanced disease. Niclosamide and related salicylanilide compounds have emerged as multitarget anticancer agents, but the molecular contexts associated with their activity remain incompletely understood. Here, we applied a phenotype-oriented integrative framework to characterize the molecular context and phenotypic activity of NSC828786, a niclosamide-like salicylanilide derivative. Cross-cohort transcriptomic analyses identified AMACR (alpha-methylacyl-CoA racemase) and HPN (hepsin) as consistently upregulated genes in independent prostate adenocarcinoma cohorts. NCI-60 profiling demonstrated broad-spectrum low-micromolar antiproliferative activity, including AR-negative prostate cancer and breast cancer cell lines spanning multiple receptor subtypes; however, quantitative ranking did not support preferential receptor subtype selectivity. CellMiner COMPARE analysis showed no significant correlation between baseline AMACR or HPN expression and NSC828786 sensitivity. Structure-based analyses supported computational compatibility of NSC828786 with predicted HPN- and AMACR-associated binding regions, while zebrafish assays showed no overt developmental abnormalities at concentrations ≤ 5 μM. These findings identify NSC828786 as a phenotypically active salicylanilide derivative and position HPN and AMACR as exploratory candidate molecular associations warranting further mechanistic and target engagement studies. Full article

Lung cancer represents a substantial global oncology burden, exhibiting mortality rates that surpass those of prostate, pancreatic, and breast cancers. Extensive research has established a correlation between exposure to polycyclic aromatic hydrocarbon mixtures—particularly those containing benzo(a)pyrene (BaP)—and elevated risks of pulmonary and dermal malignancies across various species, including humans. Hesperidin (HSP), a prominent bioactive flavonoid found in citrus fruits and medicinal herbs such as Hypericum perforatum, is recognized for its diverse pharmacological properties. The present study aimed to elucidate the antioxidant and anti-inflammatory efficacy of HSP against BaP-induced toxicity in the A549 non-small cell lung cancer (NSCLC) cell line. Following the determination of application concentrations via MTT assay, the modulatory effects of HSP on cellular proliferation, oxidative stress markers (TAS, TOS, and OSI), and key pro-inflammatory cytokines (TNF−α, IL−1β, and TGF−β) were systematically evaluated. Isolated exposure to BaP predominantly triggered a targeted upregulation of IL-1β; however, hesperidin demonstrated unexpected pro-oxidant dynamics, characterized by a substantial drop in TAS alongside a concurrent elevation in both TOS and OSI profiles, especially at maximum-dose concentrations. Notably, combining BaP with this heightened hesperidin regimen manifested the most severe oxidative distress phenotype, implying a synergistic pro-oxidant cascade between the two agents. On the contrary, minimized concentrations of hesperidin exerted explicit cytoprotective mitigation against the BaP-induced surge in IL-1β, thereby confirming a highly delicate and narrow therapeutic index for this flavonoid. Full article

Prostate stem cell antigen (PSCA), a pivotal member of the lymphocyte antigen-6 (Ly6) protein family, has been implicated in the tumorigenesis and neoplastic progression of diverse cancer types. In this study, we conducted a thorough investigation into the role of PSCA in the development of colorectal cancer (CRC). Survival analysis based on The Cancer Genome Atlas (TCGA) dataset demonstrated that elevated expression of PSCA was tightly correlated with unfavorable overall survival, inferior relapse-free survival, and worse post-progression survival among CRC patients. Additionally, PSCA exhibited significantly higher expression levels in colorectal cancer stem cell (CRC-SCs) relative to CRC cell lines. Loss-of-function assays using small interfering RNA (siRNA)-mediated silencing were performed to evaluate the effects of PSCA downregulation on the stemness properties of CRC-SCs, including proliferative capacity, invasive potential, and apoptotic rate, which were assessed by MTS assay, transwell invasion assay, and flow cytometry analysis, respectively. The results showed that silencing PSCA markedly suppressed the proliferation and invasion of CRC-SCs, while significantly promoting cellular apoptosis. RNA sequencing was performed to identify differentially expressed genes (DEGs) in the PSCA knockdown group compared to the negative control group. Follow-up analyses using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) indicated that these DEGs were significantly enriched in the cell-substrate adherens junction term and the mitogen-activated protein kinase 9MAPK signaling pathway. Moreover, PSCA silencing substantially reduced the phosphorylation levels of the core MAPK signaling constituents, pBRAF and pERK1/2; conversely, PSCA overexpression prominently upregulated the expression of pBRAF and pERK1/2. In nude mice with CRC-SCs cancer xenograft tumors, treatment with PSCA siRNA significantly decreased tumor volume and weight, while also notably extending the survival time of the tumor-bearing mice compared to the control group. Collectively, these findings confirm that PSCA plays a critical oncogenic role in CRC cancer growth and malignant progression, suggesting its potential as a novel and promising therapeutic target for CRC. Full article