SUMOylation is implicated in the regulation of multiple malignancies. However, its potential roles in head and neck squamous cell carcinoma (HNSCC) remain insufficiently characterised. By integrating bulk RNA-seq, scRNA-seq and stRNA-seq datasets, we systematically interrogated the biological relevance of SUMOylation in HNSCC. Key markers from the signature were further validated using in vitro functional assays. A recognition model was established and validated using 692 HNSCC and 178 non-HNSCC samples. SROC analysis demonstrated robust performance across eight datasets (AUC = 0.92). Functional enrichment and scRNA-seq analyses indicated that SUMOylation may exert its effects in HNSCC primarily through cell-cycle regulation. Among the model features, SAE1 was markedly overexpressed in HNSCC (SMD = 1.07, 95% CI 0.56-1.59, p < 0.05). In vitro assays further confirmed that SAE1 enhanced proliferation, colony formation and migration in SAS and SCC-9 cells and validated its role in regulating cell cycle progression and apoptosis. We established a SUMOylation-related recognition model for HNSCC with consistently strong performance in multiple external validation cohorts. SAE1 emerges as a candidate molecular biomarker for HNSCC.

SWI/SNF chromatin remodelers are represented by three biochemically distinct subcomplexes, the abundant cBAF and the less abundant PBAF and GBAF. Genetics have identified important roles for PBAF in development and disease; however, relating PBAF-mediated phenotypes to biochemical function in chromatin regulation and gene activation has been challenging. Here, we show that the PBRM1 subunit of PBAF is critical for the completion of TGFβ1-mediated epithelial-mesenchymal transition (EMT) of mammary cells in vitro as well as the metastasis of murine breast cancers in vivo. Using epigenomics to profile different stages of EMT, we find that PBRM1 is necessary for targeting PBAF to inducible promoters marked by H3K14ac. We further find that PBRM1 facilitates DNA accessibility at sites bound by TGFβ1-inducible transcription factors, such as Atf3, for the induction of genes involved in migration, cell survival, and inflammation, providing evidence that PBAF is a vulnerability in late-stage metastatic cancers.

Growing evidence indicates that nuclear architecture is severely altered in many pathological contexts, primarily in cancer, with major implications for chromatin arrangement and, consequently, gene expression. Actin microfilaments located in the perinuclear region at the apical surface of cells, collectively known as the "perinuclear actin cap", integrate mechanical and biochemical cues from the cell membrane and translate them into compressive forces acting on the nuclear envelope, thereby modulating nuclear shape and size. In concert with well-established mechanotransduction paradigms, these highly dynamic and finely tuned stress fibers are emerging as key players in several biological processes - from cell migration to sensing of the surrounding microenvironment - with significant implications for development, genetic disorders and tumor progression. However, how classic pathogenetic mechanisms intersect with perinuclear actin remodeling remains mostly unknown. In this review, we will describe in detail the unique functional and structural features of perinuclear actin stress fibers and recapitulate current knowledge on their upstream regulation by membrane receptors signaling. Finally, we will explore how alterations of the perinuclear actin cap may contribute to different pathogenetic processes, with a particular focus on cancer progression and metastasis.

Synaptotagmin-binding cytoplasmic RNA-interacting protein (SYNCRIP) is an RNA-binding protein (RBP) implicated in the pathogenesis of various cancers through involvement in regulating multiple cellular processes. Notably, this study identified that SYNCRIP expression is significantly elevated in glioblastoma (GBM) and is associated with poor prognosis and tumor progression. Mechanistically, SYNCRIP upregulates SIRT1 expression at both the transcriptional and post-transcriptional levels by stabilizing SIRT1 mRNA. Meanwhile, loss of SYNCRIP leads to reduced SIRT1 expression, accumulation of reactive oxygen species (ROS), and induction of ferroptosis. Notably, restoration of SIRT1 rescues cells from ferroptotic cell death, supporting the critical role of SIRT1 in SYNCRIP-mediated ferroptosis resistance. SYNCRIP also enhances hexokinase 2 (HK2) expression through transcriptional activation and internal ribosome entry site (IRES)-mediated translation, thereby promoting glycolytic activity in GBM. Furthermore, depletion of SYNCRIP results in mitochondrial dysfunction and impairs GBM cell migration and invasion by downregulating epithelial-mesenchymal transition (EMT)-associated factors. Collectively, these findings suggest that SYNCRIP is a key regulator of GBM progression by maintaining metabolic homeostasis and ferroptosis resistance, highlighting SYNCRIP as a potential therapeutic target in GBM.

Glioblastoma (GBM), the most common and aggressive primary brain tumor, exhibits profound metabolic reprograming that sustains its progression and therapy resistance. Our previously published work demonstrated that C3G expression is downregulated in GBM, which enhances migration and invasion. Here, we show that C3G silencing or knockout in GBM cells reprograms glucose metabolism favoring glycolysis and lactate production through upregulation of PKM2 and LDHA. Furthermore, Seahorse metabolic profiling further revealed increased respiratory capacity and glycolysis upon C3G downregulation or depletion. Mechanistically, C3G silencing increases the levels of the splicing factor PTBP1, which forces PKM splicing towards PKM2 expression as demonstrated by transient PTBP1 silencing, although other splicing factors such as SRSF3 could also contribute to PKM2 expression. Additionally, C3G downregulation or depletion enhances sphere formation, stemness and tumor initiating capacity in GBM cells, which is rescued by C3G re-expression in C3G knockout GBM cells. This enhanced stemness induced by C3G silencing in GBM cells is prevented by transient PTBP1 or PKM2 silencing or pharmacological inhibition of PKM2 with compound 3K, which also decreases cell viability within the spheres (3D-cell cultures) and the expression of stemness markers. However, in 2D-cell cultures compound 3K increases cell viability in C3G-silenced GBM cells, while decreasing that of C3G knockout cells. This supports a specific role for C3G/PKM2 axis in GBM cancer stem cells through mechanisms likely dependent on both PKM2-mediated metabolic reprogramming and nuclear effects on gene transcription. Altogether, our findings identify C3G as a novel regulator of GBM metabolism and stemness acting through PKM2, unveiling new potential diagnostic and therapeutic implications for C3G in a subset of GBM patients.

Tumor-immune cell interactions critically contribute to the progression of non-small cell lung cancer (NSCLC). In this study, we investigated the role of WNT1-inducible signaling pathway protein 3 (WISP-3) in regulating tumor cell adhesion and the underlying molecular mechanisms in lung adenocarcinoma cells. Treatment with recombinant WISP-3 significantly increased intercellular adhesion molecule-4 (ICAM-4) expression at both mRNA and protein levels in A549 and H1299 cells in a dose-dependent manner. Consistently, WISP-3 enhanced tumor-monocyte adhesion, indicating its involvement in tumor-immune cell interactions. Mechanistically, WISP-3 stimulated rapid activation of the MEK/ERK signaling cascade, as demonstrated by increased phosphorylation of MEK and ERK. Pharmacological inhibition of MEK using PD98059 or U0126, as well as direct inhibition of ERK with SCH772984, markedly attenuated WISP-3-induced ICAM-4 expression and THP-1 adhesion. These findings were further supported by siRNA-mediated knockdown of MEK or ERK, confirming the essential role of this pathway. In addition, WISP-3 suppressed the expression of hsa-miR-12131, which was identified as a negative regulator of ICAM-4. Restoration of hsa-miR-12131 significantly reduced ICAM-4 expression and impaired tumor-monocyte adhesion, indicating that miR-12131 functions downstream of MEK/ERK signaling. Collectively, these results demonstrate that WISP-3 promotes ICAM-4-dependent monocyte adhesion through activation of the MEK/ERK pathway and subsequent suppression of hsa-miR-12131. This WISP-3/MEK/ERK/miR-12131/ICAM-4 axis provides new insight into tumor-immune interactions in NSCLC and highlights potential therapeutic targets.

Tumor necrosis factor-related apoptosis-induced ligand (TRAIL) selectively induces apoptosis in cancer cells. However, many cancer cells are resistant to TRAIL because of downregulation of death receptors (DRs) and overexpression of anti-apoptotic proteins. Ubiquitin-conjugating enzyme E2N (UBE2N), also known as Ubc13, plays a central role in ubiquitin-mediated cellular activities. In this study, we aimed to explore the sensitization effect of UBE2N inhibition in TRAIL-mediated apoptosis in cancer cells. NSC697923 (a potent inhibitor of UBE2N) alone and TRAIL alone did not induce apoptosis in renal carcinoma Caki cells. However, combined treatment with NSC697923 and TRAIL significantly enhanced apoptotic cell death in cancer cells, but not in normal cells. Mechanistically, NSC697923 induced upregulation of DR5 mRNA and protein levels through CHOP-mediated DR5 transcriptional activation and ubiquitin-mediated DR5 stabilization. NSC697923-mediated DR5 mRNA upregulation was regulated by upregulation of CHOP expression, a key transcriptional factor of DR5. CHOP siRNA treatment inhibited NSC697923-mediated DR5 protein expression. Moreover, NSC697923 generated ROS, and pretreatment with ROS scavengers inhibited DR5 upregulation and NSC697923 plus TRAIL-mediated cell death. These findings suggest that UBE2N inhibitor enhances TRAIL-induced apoptosis by DR5 upregulation and UBE2N inhibition may serve as a potential strategy to overcome TRAIL resistance in cancer therapy.

Oral squamous cell carcinoma (OSCC) frequently metastasizes, leading to poor patient outcomes. Cysteine-rich angiogenic inducer 61 (Cyr61/CCN1) has been implicated in cancer progression; however, the downstream mechanism driving OSCC motility remains incompletely defined. Cyr61 expression was elevated in OSCC and associated with advanced clinicopathological features. In OSCC cell lines, recombinant Cyr61 enhanced wound closure and Transwell migration and increased intercellular adhesion molecule-1 (ICAM-1) expression at both the mRNA and protein levels. ICAM-1 silencing significantly attenuated Cyr61-induced cell motility, indicating that ICAM-1 is an important downstream effector. Mechanistically, Cyr61 signaling was initiated through integrin αvβ3 and αvβ5, as neutralizing antibodies and siRNAs targeting these integrins suppressed Cyr61-induced migration and ICAM-1 expression. Cyr61 also induced phosphorylation of PLC, PKC, and c-Src, and pharmacological or siRNA-mediated inhibition of these kinases attenuated ICAM-1 upregulation and cell migration. Moreover, Cyr61 enhanced AP-1 activity via c-Jun phosphorylation, increased c-Jun occupancy at the ICAM-1 promoter, and inhibition of AP-1 signaling diminished Cyr61-driven ICAM-1 expression and motility. Together, these data define an integrin αvβ3/αvβ5-PLC-PKC-c-Src-AP-1 axis that transcriptionally upregulates ICAM-1, promoting OSCC migration and providing a mechanistic basis for targeting Cyr61-driven migratory programs in OSCC.

ObjectiveTo investigate whether naringin enhances the chemosensitivity of nasopharyngeal carcinoma-derived CNE2 cells to paclitaxel and identify potential molecular mediators.MethodsCNE2 cells were treated with naringin alone or in combination with paclitaxel, cisplatin, or 5-fluorouracil. Cell viability, proliferation, and migration were assessed using cell counting kit-8 and Transwell assays. Transcriptomic profiling followed by bioinformatic analysis of Gene Expression Omnibus datasets (GSE53819, GSE12452, and GSE102349) was performed to identify nasopharyngeal carcinoma prognosis-related genes. AKR1C3 overexpression was established via lentiviral transduction, and pharmacological inhibition was performed using ASP9521. mRNA and protein expression were validated using reverse transcription quantitative polymerase chain reaction and Western blot analysis.ResultsNaringin (160 μM) demonstrated a trend toward reducing the half-maximal inhibitory concentration of paclitaxel from 10.52 to 8.04 nM; however, it did not significantly alter sensitivity to cisplatin or 5-fluorouracil. Combined treatment with 2 nM paclitaxel and 160 μM naringin synergistically suppressed CNE2 proliferation and migration compared with that using either agent alone (p < 0.05). Bioinformatic analysis revealed that high AKR1C3 expression was correlated with improved survival in patients with nasopharyngeal carcinoma (p < 0.05), whereas high PAIP1, PRKDC, PTPRR, and COL12A1 expressions were correlated with poorer outcomes. Reverse transcription quantitative polymerase chain reaction confirmed that both naringin and paclitaxel upregulated AKR1C3 mRNA, with the combination producing the strongest effect. Gain-of-function studies demonstrated that AKR1C3 overexpression significantly enhanced paclitaxel sensitivity, with half-maximal inhibitory concentration values decreasing from 13.63 to 6.994 nM in CNE2 cells and from 8.534 to 4.668 nM in CNE1 cells. Furthermore, the specific AKR1C3 inhibitor, ASP9521, significantly attenuated the synergistic anti-proliferative and anti-migratory effects of paclitaxel + naringin in CNE2 cells, confirming that naringin enhances chemosensitivity to paclitaxel by upregulating AKR1C3 expression.ConclusionsNaringin sensitizes CNE2 cells to paclitaxel, potentially via AKR1C3 upregulation. This flavonoid may represent a low-toxicity adjunct to enhance the efficacy of paclitaxel in nasopharyngeal carcinoma.

The objective of this study was to investigate the inhibitory effects and underlying molecular mechanisms of Isorhamnetin-3-O-neohesperidoside (IHN), a naturally occurring O-methylated flavonol, against human hepatocellular carcinoma (HepG2) cells, with a particular focus on its impact on cell proliferation, apoptosis, metabolic regulation, and oxidative stress.

Human liver cancer HepG2 cells were treated with varying concentrations of IHN for 24 and 48 hours. The cytotoxic and anti-proliferative effects were assessed using standard cytotoxicity assays. Flow cytometry was performed to analyze cell cycle distribution and apoptosis induction. Metabolic assays evaluated glucose uptake and lactate dehydrogenase A (LDH-A) activity to assess the Warburg effect. Oxidative stress markers were analyzed by measuring reactive oxygen species (ROS), lipid peroxidation, and the glutathione (GSH/GSSG) ratio. Quantitative real-time PCR (qRT-PCR) was used to determine the expression of key regulatory genes.

IHN exhibited potent, dose- and time-dependent cytotoxicity against HepG2 cells, with Half-maximal inhibitory concentration (IC₅₀) values decreasing from 161.22 μM (24 h) to 95.87 μM (48 h). IHN- induced G0/G1 cell cycle arrest accompanied by the upregulation of Cyclin-dependent kinase inhibitor 1A (CDKN1A/p21) and promoted apoptosis through the intrinsic pathway, as shown by increased expression of BCL2-associated X Protein (BAX), Caspase-3 (CASP-3), and Caspase-9 (CASP-9). Metabolically, IHN suppressed the Warburg effect, leading to reduced glucose uptake and decreased LDH-A activity. This was associated with a marked increase in ROS levels and lipid peroxidation, along with depletion of GSH/GSSG and downregulation of antioxidant genes, indicating severe oxidative stress.

IHN exerts significant anti-hepatocellular carcinoma activity by targeting multiple oncogenic pathways. Its mechanism involves cell cycle arrest, intrinsic apoptosis induction, metabolic suppression, and redox imbalance. These findings suggest that IHN is a promising multi-target natural compound that exploits the metabolic and oxidative vulnerabilities of HepG2 cells, highlighting its potential as a novel therapeutic candidate for hepatocellular carcinoma.