Head and neck squamous cell carcinoma (HNSCC) is characterized by aggressive progression, frequent therapeutic resistance, and poor clinical outcomes. Although the RNA-binding protein La/SSB is aberrantly expressed in multiple malignancies, its functional and mechanistic role in HNSCC remains incompletely understood. Here, by integrating transcriptomic and chromatin accessibility profiling with comprehensive in vitro and in vivo analyses, we identify La/SSB as a putative regulator associated with HNSCC progression and cisplatin (CDDP) resistance. La/SSB was markedly upregulated in HNSCC tissues and cell lines, and elevated expression was associated with unfavorable survival. Genetic depletion of La/SSB suppressed proliferation, migration, and invasion, promoted apoptosis, and reduced tumor growth and metastatic colonization, whereas ectopic expression exerted the opposite effects. Multi-omics analyses implicated FSCN1 as a functionally relevant downstream candidate associated with La/SSB-dependent phenotypes. Mechanistically, La/SSB depletion was associated with reduced H3K27ac enrichment and diminished TFAP2C occupancy at the FSCN1 promoter, supporting a TFAP2C/FSCN1-linked regulatory framework. Importantly, loss of La/SSB significantly enhanced CDDP responsiveness in the PDO model established in this study and in vivo conditional knockout models. Clinically, elevated La/SSB showed independent prognostic value, whereas TFAP2C and FSCN1 supported a biologically associated regulatory framework linked to aggressive disease features. Collectively, our findings identify La/SSB as a clinically relevant factor associated with HNSCC progression and CDDP responsiveness, and support a TFAP2C/FSCN1-linked regulatory framework that may contribute to malignant phenotypes.
Expression of long non-coding RNAs (lncRNAs) is frequently dysregulated in human cancers. We previously reported that the lncRNA GSEC accelerates colorectal cancer (CRC) cell motility by inhibiting the RNA helicase DHX36. Here, we demonstrated that a nuclear polypeptide (designated ‘GESP’) is translated from a short ORF encoded by GSEC, which is highly expressed in CRC cells. In vivo experiments using CRC cell-xenografted mice revealed that GESP is required for development of immature tumors through suppression of a critical differentiation factor, NDRG1. Suppression of GESP by shRNA-mediated knockdown of GSEC caused growth retardation associated with tumor differentiation. At the molecular level, GESP recruits c-Myc to the promoter region of NDRG1 by forming a GESP-NPM1-c-Myc complex, which consequently represses transcription of NDRG1. Collectively, these data indicate a novel lncRNA product, GESP, plays a pivotal role in CRC tumor development/progression by suppression of tumor cell differentiation through the GESP-NDRG1 axis.
Neuroendocrine prostate cancer (NEPC) is an increasingly recognized, highly aggressive disease variant with no actionable therapeutic targets and a life expectancy of 7 months or less. Using a transgenic mouse model, we now show that early stages of NEPC are associated with increased intraprostatic recruitment of Ly6G+ polymorphonuclear neutrophils (PMN) and reduced infiltration of CD8+ T cells. This coincided with expansive transcriptional changes of increased cell viability and cell migration, as well as upregulation of multiple neuronal mediators with the neuropeptide, Neuromedin U (NMU) as the top hit (Z score = 4.34; FDR < 5%; p = 3.62 × 10-9). Analysis of a large cohort of human patient samples revealed that NMU was highly expressed in early and late stage prostate cancer, preferentially segregating with AR-/NE+ metastases. Exposure of PMN to recombinant NMU was sufficient to stimulate cell migration, inflammatory gene expression with increased levels of the cytokine-like alarmin, S100A9 and suppression of T cell proliferation. Genetic or pharmacological targeting of NMU/S100A9 signaling inhibited NEPC growth, reinvigorated an intratumoral immune microenvironment via recruitment of tumor antigen-specific CD8+ T cells with 'stem-like' (TCF1+/PD1+) and cytotoxic (GrzB+/KLRG1+) properties and enhanced the activity of therapeutic immune checkpoint inhibition, in vivo. Therefore, NMU 'innervation' drives myeloid immunosuppression in NEPC and provides a therapeutic target to restore sensitivity to immunotherapy in this highly refractory malignancy.
Advanced bladder cancer (BLCA), a malignancy with high recurrence, carries a dismal prognosis, demanding the identification of novel therapeutic targets. In this study, we aim to investigate a critical molecular mechanism driving BLCA progression. By integrating published sequencing datasets, we identified that POC1A is overexpressed in BLCA tissues, a factor positively correlated with advanced stage, high grade, disease progression, and inversely correlated with overall survival. In vitro and in vivo analyses indicate that POC1A knockdown inhibits BLCA cell proliferation, metastasis, and stemness. Mechanistically, POC1A functions as a scaffold protein, forming a complex with USP7 and BMI1. This enhances the USP7-BMI1 interaction, reduces BMI1 ubiquitination in a USP7-dependent manner, and consequently stabilizes the BMI1 protein. The functional significance of this pathway was confirmed as overexpression of either BMI1 or USP7 rescued the inhibitory phenotypes induced by POC1A knockdown. Furthermore, pharmacological targeting of BMI1 with Unesbulin suppressed BLCA growth in cell-line and patient-derived xenograft models, supporting the therapeutic tractability of the POC1A-BMI1 axis. Taken together, these findings reveal that POC1A facilitates the USP7-mediated deubiquitination and stabilization of BMI1, establishing the POC1A-USP7-BMI1 complex as a compelling therapeutic target in BLCA.
SHANK2 is crucial for neuronal synapse development and has been implicated in certain tumors; however, its role in esophageal squamous cell carcinoma (ESCC) remains underexplored. In this study, the expression and prognostic significance of SHANK2 in ESCC were assessed through bioinformatics analyses and immunohistochemical staining. We examined the relationship between SHANK2 expression and genetic alterations across multiple ESCC datasets. The effects of SHANK2 on cell proliferation, migration, and invasion were evaluated using cell-based assays. Potential SHANK2-interacting proteins were identified via co-immunoprecipitation followed by mass spectrometry and further validated using immunoprecipitation and immunoblotting. Additionally, we investigated the in vivo role of SHANK2 in ESCC progression using tumor xenograft mouse models. Our findings demonstrated that SHANK2 expression was significantly elevated in ESCC tissues, with high levels correlating with poor patient prognosis. Genetic amplification of SHANK2 was frequently observed in ESCC samples. SHANK2 promoted the proliferation, motility, and epithelial-mesenchymal transition of ESCC cells. Mechanistically, SHANK2 may activate the YAP signaling through competitive binding with DVL2, thereby facilitating malignant progression. In vivo studies indicated that targeting YAP signaling can mitigate SHANK2-induced ESCC growth. Taken together, SHANK2 is upregulated in ESCC and activates YAP signaling by interacting with DVL2, contributing to tumor progression. The SHANK2/DVL/YAP axis presents a potential therapeutic target for ESCC.
Cisplatin-based combination therapy remains the primary treatment modality for patients with advanced bladder cancer (BCa); however, the emergence of drug resistance severely restricts clinical benefits. The molecular mechanisms underlying chemoresistance remain incompletely understood. By integrating single-cell transcriptomics with in vitro and in vivo experiments, we revealed that cholesterol metabolism was significantly hyperactivated in cisplatin-resistant BCa tissues. Further subpopulation re-clustering identified a specific chemoresistant epithelial cell subset (C3) characterized by robust cholesterol metabolism, in which the cholesterol metabolic enzyme DHCR24 was significantly upregulated and played a pivotal role in mediating cisplatin resistance in BCa. Mechanistically, the elevated expression of TFDP1 in cisplatin-resistant BCa epithelial cells upregulated DHCR24 via the formation of the TFDP1-E2F1 transcriptional complex, thereby promoting cholesterol biosynthesis. The enriched intracellular cholesterol facilitated the formation of cell membrane lipid rafts and enhanced the phosphorylation of Src, which in turn hyperactivated the downstream MAPK signaling pathway, ultimately conferring cisplatin resistance. Furthermore, the accumulated cholesterol enhanced PD-L1 protein stability, thereby impairing the efficacy of immunotherapy in BCa. Taken together, our study characterizes a specific DHCR24+ tumor epithelial subpopulation that orchestrates cisplatin resistance via the “cholesterol-lipid raft-MAPK” axis. These findings establish a clear mechanistic link between cholesterol metabolism and cisplatin sensitivity.
Although chemotherapy in colorectal cancer (CRC) primarily targets epithelial tumor cells, the epithelial cell-intrinsic mechanisms underlying heterogeneous treatment responses remain poorly understood. We integrated the genomic, transcriptomic, and in vitro drug response profiles of CRC patient-derived tumor organoids (PDTOs) with functional assays to identify epithelial cell-intrinsic determinants of chemotherapy response. An epithelial interferon-stimulated gene (ISG) program, reflecting JAK-STAT pathway activity, was associated with reduced chemosensitivity in PDTOs. Single-cell RNA sequencing data of CRC tumors before and after neoadjuvant chemotherapy showed persistent epithelial ISG expression, with EPSTI1 notably enriched in tumors with incomplete pathological responses. Functional studies demonstrated that EPSTI1 knockdown reduced CRC cell viability and enhanced chemosensitivity. Pharmacologic JAK-STAT inhibition with ruxolitinib suppressed ISG expression and attenuated chemotherapy-induced ISG upregulation. These findings highlight the utility of PDTOs for studying tumor-intrinsic mechanisms of treatment response and identify EPSTI1 as an epithelial modulator of chemosensitivity.
Primary liver cancers, including hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), arise from the neoplastic transformation of hepatocytes and cholangiocytes, respectively. Loss or downregulation of PTEN, a tumor suppressor negatively regulating the PI3K/AKT pathway, is frequently observed in CCA and HCC. Notably, PTEN mutations are observed at nearly twice the frequency in combined CCA-HCC tumors than either HCC or CCA alone. Using lineage-specific liver-targeted PTEN-deficient mouse models, we demonstrate that PTEN loss drives cellular dedifferentiation and tumorigenesis, a process that is critically dependent on AKT2. Mechanistically, PTEN deficiency induces activation of NOTCH and upregulation of transcriptional factor SOX9, which plays a central role in tumor cell transformation. In parallel, PTEN loss increases SMAD4 expression and sensitizes the tumor cells to TGFβ signaling, with TGFβ treatment repressing SOX9 expression in tumor cells lacking PTEN. Together, our study defined a critical role for PTEN-AKT2 signaling in maintaining liver epithelial lineage fidelity and revealed how its disruption promotes the conversion of mature hepatocytes or cholangiocytes into liver cancer stem-like cells (LCSCs). Furthermore, we identify a PTEN-dependent crosstalk between NOTCH and TGFβ pathways that governs liver tumor development. Together, this work provides mechanistic insight into lineage plasticity in liver cancer with implications for pathway-directed therapy.
Cancer immunotherapy, particularly immune checkpoint inhibitors (ICIs), has emerged as a pillar of modern oncology. However, clinical response rates in head and neck squamous cell carcinoma (HNSCC) remain modest, underscoring the need to identify novel therapeutic targets. Here, we investigated the role of Pentraxin 3 (PTX3) in orchestrating an immunosuppressive tumor microenvironment (TME) in HNSCC. Analysis of the TCGA dataset revealed that elevated PTX3 expression correlates with poor prognosis in HNSCC patients. Moreover, PTX3 is markedly upregulated in aggressive, ICI-resistant TAb2 tumors harboring an activated PIK3CA allele and TP53 deficiency. Using a CRISPR/Cas9 approach to delete PTX3 in TAb2 cells (PTX3-KO), we found that PTX3-KO tumors grew significantly slower than wild-type tumors in vivo. This reduced tumor growth was partially dependent on CD8+ T cells and occurred independently of tumor-intrinsic effects on cell proliferation. Genetic deletion of PTX3 profoundly reprogrammed the TME, increasing CD8+ tumor-infiltrating lymphocytes (TILs) and shifting the myeloid landscape by reducing immunosuppressive M2-like tumor-associated macrophages (TAMs) while promoting pro-inflammatory M1-like TAMs. Mechanistically, PTX3 drives M2-TAM polarization by activating downstream PI3K-γ/δ-dependent signaling, with evidence implicating the CD44 receptor. Crucially, anti-CD44 treatment or pharmacological blockade of PI3K-γ or PI3K-δ phenocopied the effects of PTX3 loss, substantially reducing M2-like TAMs and elevating M1-like TAMs. Collectively, our findings establish the innate immune molecule PTX3 as a critical regulator of myeloid-driven immune suppression in HNSCC. While PTX3 deficiency alone did not sensitize these models to PD-L1 blockade, therapeutic targeting of the PTX3-CD44-PI3K axis represents a promising strategy for remodeling the immunosuppressive TME.
Inversion of chromosome 16 [inv(16)] generates the fusion gene CBFB::MYH11 (CM) and is one of the most common chromosomal rearrangements in Acute Myeloid Leukemia (AML). Expression of CM is required for leukemia initiation. Patients with inv(16) at diagnosis invariably have the rearrangement at relapse, leading to the assumption that CM is also required after leukemic transformation. However, a role for CM in leukemia maintenance has yet to be shown experimentally. To address this, we used an inducible CM knockdown (KD) mouse model and found that decreased CM eliminated leukemia cells from the peripheral blood and spleen, but not the bone marrow, despite all populations exhibiting significantly decreased CM mRNA and protein. The surviving CM KD cells in the bone marrow showed decreased apoptosis and proliferation, and increased expression of autophagy related genes. Surprisingly, with prolonged KD of CM, ~40% of mice re-established disease despite maintaining decreased CM. Our work indicates that CM is required for leukemia survival in the spleen and peripheral blood, but in the bone marrow CM KD leukemia cells can survive and re-establish disease independent of the fusion protein. These findings imply that targeting CM alone has potential to reduce leukemic burden but not cure the disease.
Combined alterations of TP53 and CDKN2A are frequently observed in head and neck squamous cell carcinoma (HNSCC); however, their cooperative roles in oral carcinogenesis remain unclear. To investigate their interaction under carcinogenic stress, we generated Cdkn2a knock-in (KI) mice harboring a human-relevant R80X truncating mutation, along with Trp53 loss-of-function (LOF) mutants and exposed them to 4-nitroquinoline-1-oxide (4NQO). Partial loss of Cdkn2a combined with Trp53 heterozygosity was associated with increased STING-related inflammatory signaling and enhanced T-cell/NK-cell-associated immune infiltration, coinciding with delayed malignant progression. Enhanced production of proinflammatory cytokines and chemokines further indicated selective activation of the cGAS-STING-NF-κB axis. Analysis of the TCGA-HNSC cohort showed that combined TP53/CDKN2A alterations significantly separated overall survival and were associated with distinct survival patterns. These findings reveal a previously unrecognized mechanism by which imbalanced p53-RB signaling triggers tumor immunity during the early stages of oral carcinogenesis.
Cuproptosis is a novel form of programmed cell death characterized by the accumulation of copper ions in the mitochondria, the formation of DLAT oligomers, and the depletion of Fe-S cluster proteins. However, the alterations in mitochondrial morphology and function during cuproptosis and the potential role of mitophagy in cuproptosis remain insufficiently elucidated. In this study, we induced cuproptosis of breast cancer cells using Elesclomol (ES) and assessed changes in mitochondrial reactive oxygen species, mitochondrial membrane potential, and oxygen consumption rate. Stable cell lines with overexpression or knockdown of PINK1/Parkin genes were constructed to elucidate the impact of mitophagy on cuproptosis. Subcutaneous mouse xenograft models were employed to identify drugs that may synergize with ES and enhance antitumor effects. Our results demonstrated that ES induced cuproptosis of breast cancer cells, which was associated with the activation of PINK1/Parkin-mediated mitophagy. Both gene knockdown and pharmacological inhibition of mitophagy enhanced the sensitivity of breast cancer cells to cuproptosis in vitro and in vivo. The combination of dichloroacetate (DCA) and ES exhibited a synergistic antitumor effect without significant tissue damage on the brain, heart, liver, and kidneys in subcutaneous mouse xenograft models. Collectively, our findings reveal that inhibiting PINK1/Parkin-mediated mitophagy enhances the sensitivity of breast cancer to cuproptosis, offering a novel combined treatment strategy for breast cancer.
Immune evasion and an immunosuppressive tumor microenvironment contribute to the poor prognosis of gastric cancer (GC), but the mechanisms governing tumor-associated macrophage (TAM) polarization remain unclear. Here we identify P-selectin (SELP) as a key driver of GC progression and immune suppression. SELP was markedly upregulated in GC and correlated with advanced stage, increased M2 macrophage infiltration, and poor survival. Mechanistically, SELP engaged PSGL1 on TAMs to activate PI3K/AKT/mTOR signaling, which enhanced glycolysis and lactate production. Lactate in turn induced MYB, thereby promoting SELP transcription and establishing a feed-forward circuit that sustained M2-like polarization. Therapeutically, genetic or pharmacological targeting of SELP reprogrammed TAMs towards a pro-inflammatory state, increased intratumoural CD8+ T-cell infiltration, and inhibited tumor growth. Moreover, SELP inhibition with KF38789 potentiated the antitumour efficacy of PD-1 blockade in syngeneic GC models. Together, these findings define a SELP/PSGL1-PI3K/AKT/mTOR-lactate-MYB signaling axis that promotes macrophage-mediated immune evasion in GC and highlight SELP as a potential therapeutic target for improving immunotherapy response.
Circadian rhythm (CR) governs systemic and tissue physiological homeostasis by regulating sleep-wake cycles, hormone secretion, and metabolism. CR disruption (CRD), such as shift work, has been associated with increased cancer risk, particularly female breast cancer (BC), yet the mechanisms underlying breast tumorigenesis and immunosuppression resulting from a specific clock gene dysfunction remain unclear. Here, we identify that circadian regulator Period 2 (PER2) is significantly downregulated in BC and correlates with poor prognosis. PER2 functional deficiency mice (PAS-B domain deletion, Per2m/m) display high susceptibility to DMBA/MPA-induced breast tumors. Tumor microenvironment (TME) profiling reveals that compared with Per2wt tumors induced in Per2wt mice, Per2m/m tumors generated in Per2m/m mice show reduced CD8⁺ T cells and M1-like macrophages infiltration and increased Foxp3+ Tregs and M2-like macrophages. Of note, reciprocal transplantation of Per2m/m and Per2wt tumors into Per2wt or Per2m/m mouse hosts reveals that systemic PER2 functional deficiency status not only boosts tumor growth but also promotes immunosuppression in TME. Consistently, Per2 knockdown in tumor cells enhances tumor cell proliferation and immune evasion in WT hosts. Mechanistically, PER2 knockdown leads to aberrant CLOCK transactivation, which upregulates the co-expression of HER2 and CD47, thereby leading to tumor aggressive growth with limited macrophage immune checkpoint surveillance. Collectively, our findings suggest that PER2 functional deficiency-driven CLOCK-HER2/CD47 axis promotes BC susceptibility and tumor immunosuppression, which provides a potential therapeutic target to mitigate CRD-associated BC risk and aggressiveness.
Metastatic cancer remains largely incurable and is responsible for the majority of cancer-related deaths. Despite this, therapeutic strategies are still predominantly guided by insights from primary tumors, often overlooking the distinct biological features of clinical metastases. In this Review, we provide an overview of current knowledge on clinical metastatic cancer, spanning dissemination, dormancy, colonization, and therapy resistance. We examine the genomic evolution of metastatic clones, including evidence for both early and late dissemination, as well as the impact of treatment-driven selection. Furthermore, we highlight how organ-specific microenvironments shape metastatic outgrowth and therapeutic response and explore how wound-healing and regenerative programs are co-opted during colonization. Finally, we discuss clinical perspectives on treating metastases and outline how advances in single-cell and spatial multi-omics technologies are transforming our ability to interrogate metastatic disease at high resolution, concluding with future perspectives.
The plasma membrane EGFR ligand, amphiregulin (AREG), is key to mammary luminal progenitor differentiation and governs estrogen-induced ductal elongation during puberty. However, AREG has also been detected in the nucleus of several epithelial cancers, although the physiological stimulus and nuclear function are not known. Using immortalized normal and BRCA2mut/+ mammary epithelial cells (MECs), we have discovered that endogenous AREG is required for maintenance of constitutive heterochromatin. Replication stress (RS) transiently increased prelamin A association with AREG in the cytoplasm, followed by incorporation into the nuclear membrane (NM), resulting in increased H3K9me3 heterochromatin in an ATR-dependent manner. Enforced nuclear AREG increased, while siRNA-mediated depletion of AREG reduced HP1α and SUV39h1 proteins, accompanied by global decompaction and reduction in H3K9me3 heterochromatin despite the presence of exogenous soluble AREG. Depletion of AREG also impacted the nuclear membrane, including dissipation of the Ran-GTPase gradient and formation of nuclear ruptures and invaginations. Loss of H3K9me3 with AREG knockdown increased replication origin usage and depleted nucleotide while enhancing global transcription. Reduced endogenous AREG also amplified RS-induced DNA damage, underscored by increased senescence of AREG-depleted BRCA2mut/+ MECs. Overall, this study reveals a novel and fundamental role for nuclear AREG in heterochromatin maintenance and genome stability in proliferating MECs.
Anterior Gradient 2 (AGR2) is an endoplasmic reticulum (ER)-resident protein that belongs to the protein disulphide isomerase (PDI) family, and whose expression and secretion are induced by stress. Extracellular (secreted) AGR2 has been proposed as a marker of ER stress-related proteostasis alterations. Cancer cells frequently overexpress intracellular AGR2 (iAGR2) and secrete extracellular AGR2 (eAGR2). These features are associated with tumour progression and may serve as potential biomarkers in epithelial ovarian cancer (EOC). To investigate the roles of both iAGR2 and eAGR2 in EOC, we first generated EOC cells overexpressing iAGR2 and secreting eAGR2. Antibodies blocking eAGR2 reduced the proliferation and migration of these overexpressing cells. Concurrently, supplementation of parental cells with recombinant eAGR2 partially rescued these properties, further supporting a functional extracellular role for AGR2 in EOC. Quantitative proteomics, complemented by analysis of the TCGA database, revealed that eAGR2 modulated the expression of proteins involved in autophagy. This suggests that eAGR2-induced signalling may enhance catabolic activity under stress conditions, thereby increasing nutrient availability and, in turn, facilitating protein synthesis. This was reflected in the increased translational activity observed in AGR2-overexpressing and eAGR2-stimulated cells. Our results highlight two distinct, compartmentalised roles for AGR2. Specifically, iAGR2 acts as an ER-resident PDI, enhancing protein folding and ER quality control. In a complementary manner, eAGR2 functions as a metabolic regulator that may relieve constraints on tumour cell aggressiveness by maintaining autophagic flux and promoting protein synthesis. Overall, these findings support a dual-compartment model in which iAGR2 couples ER proteostasis with the metabolic and translational stimulation mediated by eAGR2.
Alternative polyadenylation (APA) generates mRNA isoforms with distinct 3' untranslated regions (3'UTRs), thereby influencing transcript stability and translation. In cancer, 3'UTR shortening can activate oncogenes by escaping microRNA (miRNA)-mediated repression, but its role in hepatocellular carcinoma (HCC) remains poorly defined. Here, we profiled mRNA length alterations in multistage human HCC transcriptome datasets and investigated their functional consequences. Approximately 77% of mRNAs with altered length exhibited 3'UTR shortening. Glypican-3 (GPC3) was the most prominently upregulated shortened transcript, and high GPC3 expression was associated with poor prognosis in HCC. GPC3 knockdown reduced proliferation and induced apoptosis, whereas GPC3 overexpression promoted cell growth. Among APA regulators, Cleavage Stimulation Factor 2 (CSTF2) was upregulated in HCC, correlated positively with GPC3 expression, and predicted adverse clinical outcomes. Modulation of CSTF2 expression altered GPC3 3'UTR length, with CSTF2 overexpression promoting GPC3 3'UTR shortening, increasing GPC3 protein expression, enhancing proliferation, and suppressing apoptosis. Further analysis revealed that GPC3 3'UTR shortening removed binding sites for miR-96-5p and miR-140-5p, relieving miRNA-mediated translational repression. These findings identify CSTF2-driven APA as a mechanism of oncogenic GPC3 activation in HCC and suggest the CSTF2-GPC3 axis as a potential therapeutic target.
