Search Results (453)

Background/Objectives: The orphan nuclear receptors 4A1 (NR4A1) and NR4A2 are overexpressed in multiple solid tumors, and both receptors exhibit tumor promoter-like activities. A recent study reported that luteolin, a flavonoid that binds NR4A1, decreased the expression of the pro-oncogenic receptor tyrosine kinase MerTK in colon cancer cells. Methods/Results: In this study, we observed that MerTK protein was expressed in human SW480 and HCT116 and mouse CT26 colon cancer cell lines, and was significantly downregulated after treatment with 1,1-bis(3′-indolyl)-1-(3,5-disubstitutedphenyl)methane (DIM-3,5) compounds, which are dual NR4A1/NR4A2 ligands. Moreover, knockdown of NR4A1 and NR4A2 also decreased MerTK protein expression and DIM-3,5 ligands, and receptor knockdown also decreased MerTK RNA levels expression. MerTK expression was also downregulated by knockdown of Sp1, Sp3, or Sp4 and by treatment with mithramycin. Subsequent studies using chromatin immunoprecipitation and transfection of a MERTK (promoter)–luciferase construct containing transcriptionally active GC-rich promoter elements indicated that MerTK expression in colon cancer cells was regulated by NR4A/Sp complexes, including NR4A1, NR4A2, Sp1, Sp3, and Sp4 transcription factors. Conclusions: The participation of NR4A1 and NR4A2 in the regulation of MerTK indicates that DIM-3,5 ligands represent a novel class of agents that can be used to inhibit MerTK expression in cancer cells by acting as dual NR4A1 and NR4A2 inverse agonists. Full article

Andean berry (Vaccinium meridionale Swartz) is an underutilized fruit that could serve as a source of bioactive compounds with biological properties associated with apoptosis and cytotoxicity in colorectal cancer cells. This study aimed to evaluate the cytotoxic and proapoptotic effects of Andean berry juice (ABJ) in human SW480 and SW620 colon cancer cell lines, which represent early-stage and metastatic colorectal cancer, respectively. The juice was prepared from freeze-dried fruits, and several concentrations were assayed in cells. Bioactive compounds in ABJ showed the strongest reductions in metabolic activity and proliferation observed in SW620 cells. ABJ treatments promoted early apoptosis while inducing cell cycle arrest in the S phase (SW480) and in the G2/M (SW620). Mild mitochondrial depolarization was observed, while increased reactive oxygen species (ROS) accumulation was detected in both cell lines. More proteins involved in the apoptotic process were modulated in SW620 cells, whereas SW480 displayed greater fold changes in regulatory and stress-response proteins. Proteomics and bioinformatics analyses suggested that extrinsic apoptosis predominated in SW480 cells, whereas intrinsic apoptosis was observed in SW620 cells. These results highlighted the cytotoxic and pro-apoptotic potential of the combined activity of polyphenolic compounds from ABJ, demonstrating distinct mechanisms in vitro. Full article

Background/Objectives: Colorectal cancer (CRC) remains a leading cause of cancer-related mortality, with poor outcomes in advanced stages and significant limitations in current chemotherapy regimens due to systemic toxicity. Extracellular vesicles (EVs) have emerged as promising natural drug delivery vehicles, offering the potential for targeted, less toxic therapies. This study investigates the feasibility of using autologous, patient-derived EVs as a delivery system for the chemotherapeutic agent doxorubicin, focusing on how disease stage and the EV protein corona influence loading and delivery efficiency. Methods: EVs were isolated from plasma and tissue samples of CRC patients at different disease stages, as well as from healthy controls, demonstrating successful isolation and characterisation of EVs, with distinct profiles across different sources. Results: Doxorubicin loading into EVs was significantly higher in CRC patient-derived EVs compared to healthy controls, and tissue-derived EVs yielded higher quantities of drug-loaded particles. Delivery of doxorubicin-loaded EVs to recipient CRC cell lines (SW480 and SW620) revealed that disease stage impacts both EV uptake and drug delivery, with late-stage EVs showing reduced uptake and delivery efficiency. The protein corona, known to coat circulating EVs, was found to influence drug loading and delivery. Pre-treatment of cell line-derived EVs with plasma proteins enhanced EV uptake but reduced doxorubicin loading and subsequent delivery, particularly when using plasma from healthy volunteers. Conclusions: These findings underscore the importance of EV source and protein corona composition in optimising drug delivery strategies. Our results suggest that autologous, patient-derived EVs hold potential as a targeted drug delivery system for CRC, but highlight the need for further optimisation of EV isolation, loading methods, and understanding of how disease progression affects EV functionality. This approach could ultimately reduce systemic toxicity and improve therapeutic outcomes for CRC patients. Full article

Objectives: This study aimed to investigate the phytochemical content of the endemic plant Thymus fedtschenkoi var. handelii (Ronniger) Jalas and, for the first time, to examine its anticancer potential on various cancer cell lines. Methods: The plant was collected from its natural habitat and the essential oils’ (EOs) composition was analyzed using GC-MS. The anticancer efficacy and cytotoxicity of plant extracts and the EOs were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) methods on lung (A549, Calu1, H1650), bone (SW1353, MG63, Saos2), prostate (PC3, DU145, LNCaP) and brain (A172, B35, C6) cancer cell lines, as well as normal cell lines (Beas2B, FL, HC). Results: The main components of the EOs were determined to be high amounts of carvacrol (51.12%), γ-gamma-terpinene (16.87%), and p-cymene (14.76%). Both the extract (GI₅₀: 1.10–3.28 µg/mL) and the EOs (GI₅₀: 1.05–2.03 µg/mL) exhibited strong antiproliferative activity. However, the EOs demonstrated markedly superior growth suppression, with TGI values of 1.97–9.19 µg/mL, whereas the extract required substantially higher concentrations (110.6–261.5 µg/mL). The LC₅₀ values of all samples exceeded 500 µg/mL in all cell lines tested, indicating that the natural compounds predominantly had a cytostatic effect. Normal cells showed comparable reduced sensitivity, supporting selectivity. Morphological analyses further confirmed treatment-induced cellular alterations consistent with antiproliferative and apoptotic processes. Overall, essential oils emerged as the most effective fraction, combining low TGI values with moderate cytotoxicity and showing promise in in vitro activity. Conclusions: The potent and selective antiproliferative activity of T. fedtschenkoi var. handelii may hold significant therapeutic potential in the pharmaceutical industry. Full article

Background/Objectives: Amplitude-modulated radiofrequency (AMRF) fields have emerged as promising non-temperature-induced strategies in oncology. While conventional hyperthermia (HT) relies on thermal stress, the biological impact of AMRF, particularly in combination with radiotherapy (RT), remains insufficiently characterized. Methods: We assessed RF and AMRF, alone or with RT, using phenotypic analyses of proliferation, apoptosis, and necrosis across four cancer cell lines (HT29, SW620, U343, U138). Transcriptomic profiling with Kyoto Encyclopedia of Genes and Genomes (KEGG), GO:BP, and Reactome enrichment was performed in SW620 and U138 cells, selected for their strong phenotypic responses. Results: Across the panel, AMRF was associated with broader cytotoxic responses than RF or HT in most but not all cell lines. AMRF+RT produced the strongest necrotic responses, with cell-line-specific exceptions identified explicitly in the Results (the absence of a significant AMRF+RT apoptotic effect in SW620 and the absence of a significant AMRF+RT necrotic response in U343). In SW620 cells, AMRF was associated with extensive transcriptional reprogramming involving immune modulation, extracellular matrix remodeling, and cell cycle regulation, whereas RF alone showed narrower and delayed effects. In contrast, U138 cells showed elevated apoptosis and necrosis but limited transcriptional changes—a phenotype–transcriptome divergence that points to mechanisms operating downstream of transcription and warrants functional investigation in dedicated follow-up studies. Conclusions: AMRF and AMRF+RT emerge as promising non-temperature-induced anticancer modalities in the cell-line models profiled here, with the pattern of response varying between cell lines. These findings expand the biological impact of RF-based treatments and set the grounds for further investigation in mechanistic and translational studies. Full article

Background/Objectives: Triptolide (TP), a potent natural diterpenoid, exhibits anti-glioma activity, but faces significant clinical translation challenges, including poor water solubility, systemic toxicity such as hepatotoxicity, and inadequate tumor targeting. This study aimed to develop a novel epidermal growth factor receptor (EGFR)-targeted liposomal formula-tion, designated as TP-CTX-Lip (where CTX denotes cetuximab), to enhance the deliv-ery efficiency and therapeutic window of TP. Methods: The formulation was optimized using a uniform design approach (four factors, six levels) and prepared via thin-film hydra-tion–ultrasonication. The encapsulation of TP was supported by Fourier transform in-frared spectroscopy (FTIR) and thermal analysis (DSC/TGA), which revealed molecu-lar interactions (e.g., hydrogen bonding) with lipid components and a marked en-hancement in thermal stability, consistent with successful incorporation into the lipo-somal bilayer. The physicochemical properties, including the size, polydispersity index (PDI), zeta potential, encapsulation efficiency, and drug loading, were characterized. In vitro release kinetics were evaluated in phosphate buffer (pH 7.4), and cytotoxicity was assessed in high-EGFR (U87-MG) and low-EGFR (SW1088) glioma cells. In vivo efficacy and developmental toxicity were investigated using zebrafish models. The op-timized TP-CTX-Lip demonstrated favorable characteristics: size = 131.3 ± 4.5 nm, PDI = 0.24 ± 0.006, zeta potential = −23.37 ± 0.27 mV, encapsulation efficiency = 85.83% ± 1.81%, and drug loading = 13%. In vitro release followed first-order kinetics dominated by Higuchi diffusion (79.0% ± 4% at 24 h). After 48 h of treatment, TP-CTX-Lip exhib-ited significantly enhanced cytotoxicity in U87-MG cells (IC50 = 10.4 ± 0.2 nM), com-pared with IC50 values of 42.8 nM in SW1088 cells and 45.3 nM for non-targeted lipo-somes. In the 3T3-L1 non-cancerous cell line, the 48 h IC50 value of TP-CTX-Lip (8.433 ± 0.954µM) was higher than that of the TP solution (2.173 ± 0.181µM) but lower than that of TP-Lip (25.78 ± 2.691µM). Specifically, in 3T3-L1 cells, the 48 h IC50 of TP-CTX-Lip (8.43 µM) was approximately 4-fold higher than that of free TP (2.17 µM), confirming its substantially reduced cytotoxicity against non-cancerous cells. Results: In comparison to TP-Lip and free FITC solution, the uptake rate of TP-CTX-Lip in U87-MG cells exhibited a significantly higher level. Specifically, the uptake rate for the TP-CTX-Lip group (57.46 ± 5.44%) was statistically significantly higher than that of TP-Lip (13.7 ± 2.33%) and the free FITC solution group (20.97 ± 1.60%) (p < 0.01). In zebrafish, TP-CTX-Lip reduced developmental toxicity, with LC50 increased 1.26 times to 5.733 μg/mL, and suppressed orthotopic U87-MG xenograft growth (p < 0.001), in-dicating an improved therapeutic window as reflected by the LC50/IC50 ratio. Conclusions: the EGFR-targeted TP-CTX-Lip significantly enhances the tumor selectivity and safety of TP, providing a promising strategy for targeted glioma therapy. Full article

MicroRNAs (miRNAs) play important roles in the regulation of gene expression and are frequently dysregulated in cancer. Among them, the miR-196 family has been implicated in multiple malignancies, including colorectal cancer (CRC), but the isoform-specific transcriptional effects of miR-196A and miR-196B remain poorly understood. In this study, we generated miR-196A and miR-196B knockout SW48 CRC cell lines using CRISPR-based genome editing and performed RNA sequencing to investigate the transcriptional consequences of individual miR-196 isoform deletion. Transcriptomic analysis revealed widespread gene expression changes in both knockout models and demonstrated distinct clustering patterns between parental SW48 cells and miR-196-deficient cells. Functional enrichment analysis indicated that the altered genes were associated with biological processes related to cytoskeletal organization, intracellular transport, protein folding, and metabolic regulation. Notably, both shared and isoform-specific transcriptional alterations were observed, suggesting that miR-196A and miR-196B contribute to partially overlapping but distinct regulatory networks in CRC cells. Collectively, these findings provide a comprehensive transcriptomic overview of miR-196 isoform deletion in colorectal cancer cells and highlight potential isoform-dependent transcriptional programs that may contribute to CRC biology. Full article

Natural products from plants have played an important role in cancer and neurodegenerative diseases. In this context, the root bark of Maytenus chiapensis (Celastraceae) was investigated to examine its chemical constituents and potential biological activities. Chromatographic separation of the root bark extract yielded a new Diels–Alder adduct (morenine) formed by a triterpenophenolic moiety derived from tingenone and a bicyclic guaiane-type sesquiterpene linked through a 1,4-dioxane bridge. In addition, eight previously reported Diels–Alder adducts—retusonine and cheiloclines A–D and F–H—were isolated, together with their biosynthetic precursors, the quinone-methide triterpenoids (QMTs) pristimerin and tingenone. Structural elucidation was achieved through detailed 1D and 2D NMR spectroscopic analyses. The adducts were tested for cytotoxicity against six cancer cell lines (A549, SW1573, MIA PaCa-2, T-47D, HeLa, and WiDr cell lines), showing moderate-to-low activity compared with their precursors. Continuous live cell imaging identified apoptosis and vacuole formation as the main modes of action of pristimerin in SW1573 cells. Moreover, acetylcholinesterase inhibition assays revealed that cheiloclines B–D, F, and H exhibited up to 50% inhibition. These findings reinforce the potential of Celastraceae species as a source of unique and complex compounds and enhance our understanding of their therapeutic potential. Full article

Natural products from bryophytes represent an underexplored source of structurally diverse bioactive compounds. In this study, extracts of Isotachis serrulata collected in southern Ecuador were evaluated for antiproliferative activity against five human tumor cell lines. Sequential extraction and chromatographic fractionation yielded six fractions, among which fraction IsF5 displayed the most notable activity, particularly against lung (SW1573) and breast (T-47D) cancer cell lines, with GI₅₀ values within the moderate activity range according to National Cancer Institute criteria. Phytochemical investigation of IsF5 revealed the presence of two glycosylated aromatic constituents, tentatively assigned as tachioside and isotachioside, based on comparative ¹H and ¹³C NMR spectroscopic analysis. These compounds were obtained as a mixture and were not evaluated individually due to limited material. Additionally, species distribution modeling using MaxEnt indicated that I. serrulata is primarily associated with humid montane and páramo ecosystems in the southern, central and northern Andes of Ecuador, where elevation and precipitation variables strongly influence its distribution. This study provides the first integrated assessment of the antiproliferative activity, chemical profiling, and ecological distribution of I. serrulata. Full article

Herbal melanin (HM), previously reported for its antiproliferative and pro-apoptotic properties, has garnered interest as a promising anti-colorectal cancer drug. However, HM’s biological effects and underlying molecular mechanisms and the related signaling pathways in colorectal cancer (CRC) cell motility are poorly investigated. To evaluate the impact of various concentrations (50, 100, and 200 μg/mL) of HM on cell migration, invasion, and tumorigenicity on human HT29 and SW620 CRC cell lines, a real-time cell analyzer instrument and colony formation assays were employed, respectively. An angiogenesis-related protein array was also used, and the levels of protein expression contributing to colony formation and extracellular proteolysis-driven cell migration and invasion, such as E-cadherin, N-cadherin and urokinase-type plasminogen activator receptor (uPAR), were monitored using Western blotting and RT-qPCR technologies. HM significantly decreased CRC cell motility, invasiveness, and formation of colonies, associated with E-cadherin upregulation and N-cadherin downregulation. In addition, HM specifically inhibited uPAR expression levels, which were also decreased by the pharmacological mitogen-activated protein kinase (MAPK) kinase (MEK) inhibitor UO126 and Jun N-terminal kinase (JNK) inhibitor SP600125, in both CRC cell lines, including metastatic CRC (mCRC) SW620 cell line. Addition of HM to cells pretreated with JNK and MEK inhibitors attenuated the blockade of JNK and ERK phosphorylation and alleviated HM-downregulated uPAR expression and HM-inhibited mCRC cell migration. In conclusion, our in vitro studies demonstrate that HM exhibits an inhibitory effect on CRC migration and invasiveness, associated with uPAR downregulation through JNK and ERK pathways. Full article

Background: Small nucleolar RNAs (snoRNAs) are emerging regulators of tumorigenesis, yet their pan-cancer landscape and immunological roles remain poorly defined. This study investigates the expression pattern, prognostic significance, and immune correlation of SNORA12 across cancers, with mechanistic validation in osteosarcoma. Methods: We integrated RNA-seq data from the TCGA, TARGET, and GTEx databases to evaluate SNORA12 expression and its prognostic value using Cox regression and Kaplan–Meier analyses (progression-free survival, PFS). The correlation between SNORA12 and the tumor immune microenvironment was assessed using six independent algorithms (TIMER, EPIC, CIBERSORT, IPS, MCP-counter, xCELL). In vitro, the regulatory effect of SNORA12 on the immune checkpoint TIGIT was validated by overexpression and knockdown experiments in osteosarcoma cell lines (SW1353, U2OS) and NK cells. Results: SNORA12 expression exhibited significant tumor-type specificity. High SNORA12 expression was associated with poor prognosis in glioma (HR = 1.31, p = 0.006) but favorable outcomes in pancreatic (HR = 0.51, p = 0.01) and breast cancer (HR = 0.56, p = 0.02). Immunologically, SNORA12 showed robust positive correlations with CD8+ T cell infiltration in thyroid carcinoma (THCA) and lung adenocarcinoma (LUAD) across multiple algorithms. Notably, SNORA12 expression was positively correlated with m6A modifiers METTL3 and YTHDF1, and negatively correlated with the demethylase FTO. Experimentally, overexpression of SNORA12 in osteosarcoma cells and primary NK cells significantly upregulated TIGIT at both the mRNA and protein levels, while SNORA12 knockdown in NK92 cells reduced TIGIT expression. Conclusions: This pan-cancer analysis positions SNORA12 as a tumor type-specific prognostic biomarker and reveals its novel role as a positive regulator of TIGIT in osteosarcoma, offering a potential mechanistic link between snoRNA dysregulation and immune evasion. Full article

Three new cyclic tetrapeptides (nectriatidels A-C, 1–3), two new curvularin analogs (6 and 7), and four known compounds (4 and 5, 8 and 9) were isolated from the marine-derived fungal-bacterial symbiont Aspergillus spelaeus GXIMD 04541/Sphingomonas echinoides GXIMD 04532, which was obtained from Mauritia arabica in shallow coastal waters. Their structures were elucidated through NMR spectroscopy and HRESIMS, and their absolute configurations were determined by Marfey’s method and quantum chemical calculations. Compounds 1–5 showed moderate amphotericin B (AmB)-potentiating activity against Candida albicans. Compounds 7 and 8 exhibited significant activities against Mycobacterium tuberculosis, with MIC values of 32 and 16 μg/mL, respectively. Additionally, compounds 7 and 8 exhibited moderate cytotoxicity against human colorectal cancer cell lines DLD-1 and SW480, with IC₅₀ values of 25~36 μM. Whole-genome sequencing of A. spelaeus revealed a 35.91 Mb assembly encoding 106 biosynthetic gene clusters (BGCs). antiSMASH analysis revealed that 79 of these BGCs (74.5%) displayed no significant similarity to known pathways in the MIBiG database, which is dominated by hybrid clusters, terpene, T1PKS, NRPS, and NRPS-like types. Genomic analysis identified the putative biosynthetic gene clusters for these metabolites and confirmed the fungal host as the predominant producer. Full article

Chemoresistance remains a major barrier to effective colorectal cancer (CRC) therapy, yet its metabolic underpinnings are poorly defined. Here, we integrate lipidomic profiling, enzymatic analysis, and functional perturbation approaches to elucidate the contribution of phosphatidylcholine (PC) metabolism and its biosynthetic regulator Choline Phosphotransferase 1 (CHPT1) to drug response. Comparative analysis of chemosensitive and chemoresistant CRC cell lines revealed that resistant HT29 cells exhibited significantly higher PC content and altered PC/lysophosphatidylcholine (LPC)ratios relative to sensitive counterparts. Importantly, functional perturbation confirmed causality: CHPT1 overexpression in SW620 cells was sufficient to promote PC accumulation and confer a chemoresistant phenotype. These findings identify CHPT1 as a metabolic gatekeeper of chemoresistance. Consistently, Human Protein Atlas survival analyses further support its clinical relevance, as elevated CHPT1 expression correlates with poor patient outcomes in CRC. Mechanistically, CHPT1-driven PC enrichment may sustain pro-survival signaling, while reducing lysophospholipid-mediated stress pathways. To therapeutically target this vulnerability, we investigated edelfosine (Edel), an alkyl-lysophospholipid that disrupts lipid rafts and inhibits PC biosynthesis upstream of CHPT1. Notably, edelfosine-mediated disruption of the Kennedy pathway enhances chemosensitivity in the resistant CRC model. Collectively, our study identifies CHPT1 and PC metabolism as central determinants of CRC drug response and proposes edelfosine-based metabolic reprogramming as a promising strategy to overcome resistance. Full article

Background: When tumors are surgically removed, an immediate rise in circulating tumor cells is often observed, accompanied by several postoperative changes that can enable these cells to evade immune detection and metastasize. The perioperative period following tumor resection can often promote the formation of new distant micrometastatic foci triggered by upregulation of distinct molecules. Our lab previously reported an increase in distinct inflammatory cytokine molecules following surgical resection in prostate, breast, and colorectal cancer patients, and the secretion of these signals begins as early as 2–24 h after surgery. Here, we investigated whether these distinct cytokines could orchestrate the formation of tunneling nanotube (TNT) conduits to enhance cancer cell migration. Methods and Results: Here, we provide supporting evidence that specific pro-inflammatory cytokines upregulated following cancer surgery may be potential triggers of disease recurrence and migration through TNT formation. In the tumor microenvironment, TNTs act as conduits between cancer and normal cells, facilitating the transfer of organelles that contribute to cancer cell survival and metastasis. Here, The effects of TGF-β1, IL-6, and HGF cytokines on the development of TNT conduits between adjacent cancer cells, as well as the effects of oseltamivir phosphate (OP) treatment, were measured using fluorescent microscopy and image analysis software. In PANC-1 pancreatic cancer cells, the addition of these cytokines significantly increased (p < 0.009) the quantity and extent of TNTs compared with untreated control cells. MCF-7 breast cancer cells yielded comparable results, with a significant increase in TNT observed in cells treated with TGFβ-1, IL-6, and HGF. In contrast, SW620 colorectal cancer cells did not express TNTs in response to any of the three cytokines tested. OP treatment with cytokines significantly reduced TNT formation in pancreatic and breast cancer cells, with no effect on the colorectal SW620 cancer cell line. Cell migration in response to cytokines was assessed using the scratch wound assay. Out of the three cell lines analyzed, the PANC-1 cells fully closed after 12 h of the wound gap. In contrast, the SW620 and MCF-7 cells had no significant change in wound closure rate following cytokine treatment. The SW620 cells exhibited a slight but insignificant increase in the wound closure rate with TGFβ-1 and HGF treatment, while IL-6 in the SW620 cells and all three cytokines in the MCF-7 cells were comparable to the control. OP significantly reduced the scratch wound closure rate on PANC-1, SW620, and MCF-7 cells treated with these cytokines. Conclusions: These findings further support the link between perioperative cytokine activity and increased metastatic potential by promoting the formation of intercellular tunneling nanotube conduits. OP, a specific inhibitor of the mammalian neuraminidase-1 (NEU-1) enzyme, disrupts this process. Full article

Background/Objectives: Sarcomas are malignant bone tumors for which current therapeutic approaches provide limited improvement in patient survival. Cancer-associated extracellular acidosis, driven in part by Na⁺/H⁺ exchanger 1 (NHE1) activity, promotes malignant cell migration and proliferation while exerting inhibitory effects on normal bone-forming cells. Calcineurin Homologous Protein 2 (CHP2) is a binding partner and functional regulator of NHE1 that is preferentially expressed in cancer cells; however, its role in bone sarcoma biology remains undefined. Methods: In this study, we examined how serum deprivation, used as a model of metabolic stress, affects migration and proliferation in human bone sarcoma cell lines (143B and SW1353) and investigated the contribution of NHE1 and CHP2 to these behaviors. Results: Serum deprivation induced a time-dependent adaptive response in sarcoma cells, characterized by transient suppression followed by recovery of migratory and proliferative capacity, whereas both migration and proliferation were consistently inhibited in non-malignant osteoblastic (hFOB) cells. Both sarcoma cell lines predominantly expressed NHE1, and pharmacological inhibition of NHE1 activity with zoniporide significantly reduced migration and moderately reduced proliferation. Serum deprivation did not significantly alter CHP1 or CHP2 protein expression; however, silencing of CHP2 reduced NHE1 activity under serum-deprived conditions and significantly decreased migration and proliferation in both sarcoma cell lines. Conclusions: Together, these findings demonstrate that NHE1 activity is a critical determinant of migratory capacity in bone sarcoma cells and that CHP2 supports malignant migration and proliferation. Under stress conditions, CHP2 action is associated with NHE1 activity, supporting CHP2 as a conditional modulator of malignant behavior in human bone sarcoma cells. Full article