Glioma stem cells promote radioresistance by preferential activation of the DNA damage response

Diversity of metabolic features and relevance to clinical subtypes of gliomas

Gliomas carry a dismal prognosis and have proven difficult to treat. Current treatments and efforts to target individual signaling pathways have failed. This is thought to be due to genetic and epigenetic heterogeneity and resistance. Therefore, interest has grown in developing a deeper understanding of the metabolic alterations that represent drivers and dependencies in gliomas. Therapies that target glioma-specific metabolic dependencies overcome the challenges of disease heterogeneity. Here, we present the diverse metabolic features of each current clinical subtype of glioma. We believe that this approach will enable the development of novel strategies to specifically target the various clinical and molecular subtypes of glioma using these metabolic features.

Advances in the study of epithelial mesenchymal transition in cancer progression: Role of miRNAs

Epithelial-mesenchymal transition (EMT) has been extensively studied for its roles in tumor metastasis, the generation and maintenance of cancer stem cells and treatment resistance. Epithelial mesenchymal plasticity allows cells to switch between various states within the epithelial-mesenchymal spectrum, resulting in a mixed epithelial/mesenchymal phenotypic profile. This plasticity underlies the acquisition of multiple malignant features during cancer progression and poses challenges for EMT in tumors. MicroRNAs (miRNAs) in the microenvironment affect numerous signaling processes through diverse mechanisms, influencing physiological activities. This paper reviews recent advances in EMT, the role of different hybrid states in tumor progression, and the important role of miRNAs in EMT. Furthermore, it explores the relationship between miRNA-based EMT therapies and their implications for clinical practice, discussing how ongoing developments may enhance therapeutic outcomes.

MiR-326: Role and significance in brain cancers

MicroRNAs (miRNAs) are small non-coding RNAs that act as critical regulators of gene expression by repressing mRNA translation. The role of miRNAs in cell physiology spans from cell cycle control to cell proliferation and differentiation, both during development and in adult tissues. Accordingly, dysregulated expression of miRNAs has been reported in several diseases, including cancer, where miRNAs can act as oncogenes or oncosuppressors. Of note, miRNA signatures are also under investigation for classification, diagnosis, and prognosis of cancer patients. Brain tumours are primarily associated with poor prognosis and high mortality, highlighting an urgent need for novel diagnostic, prognostic, and therapeutic tools. Among miRNAs investigated in brain tumours, miR-326 has been shown to act as a tumour suppressor in adult and paediatric brain cancers. In this review, we describe the role of miR-326 in malignant as well as benign cancers originating from brain tissue. In addition, since miR-326 expression can be regulated by other non-coding RNA species, adding a further layer of regulation in the cancer-promoting axis, we discuss this miRNA's role in targeted therapy for brain cancers.

Evaluation of folic acid-targeted gadolinium-loaded perfluorohexane nanodroplets on the megavoltage X-ray treatment efficiency of liver cancer

The efficacy of radiation therapy can decrease due to the inherent radioresistance of different tumor cells. Gadolinium shows significant potential as a radiosensitivity enhancer due to its high atomic number. In this study, a novel theranostic nanoprobe based on folic acid-conjugated gadolinium-loaded nanodroplets (FA-Gd-NDs) has been introduced for ultrasound imaging (USI)-guided radiation therapy of hepatocellular carcinoma. The ultrasound echogenicity evaluation of NDs, Gd release studies, biocompatibility test of Gd-NDs, colony assay, cellular uptake of NDs via fluorescence microscopy, and flow cytometry analysis were performed on Hepa1-6 cancer and L929 normal cell lines. Our results showed that synthesized NDs significantly enhanced ultrasound signal intensity in PBS solution and agarose gel phantom. MTT and clonogenic assays indicated that Gd-NDs substantially reduced the cell viability and also surviving fraction of Hepa1-6 cancer cells under US and X-ray exposure. Additionally, FA-Gd-NDs exhibited sensitization enhancement factor (SER) of 1.8 after concurrent exposure to US and X-ray. Fluorescence imaging demonstrated more internalization of FA-Gd-NDs into cancer cells in comparison with normal cells. According to flow cytometry results, the Gd-NDs and FA-Gd-NDs uptake by L929 cell line were 20 % and 28 %, respectively, while their uptake by Hepa1-6 cells was 60 % and 94 %, respectively. In conclusion, the synthesized novel theranostic nanoprobe shows great potential for enhancing the efficacy of radiation therapy and enabling ultrasound image-guided radiation therapy of cancers.

FOXM1 Promotes Non-Small Cell Lung Cancer Progression by Increasing CHEK1 Expression

OBJECTIVE

Non-small cell lung cancer (NSCLC) is a leading cause of cancer-associated mortality. This study aimed to investigate the role of checkpoint kinase 1 (CHEK1) in NSCLC progression and its regulatory relationship with forkhead box protein M1 (FOXM1).

METHODS

Transwell assays were used to evaluate the migration and invasion capabilities of NSCLC cells with either CHEK1 overexpression or knockdown. The expression of epithelial-mesenchymal transition (EMT) markers in NSCLC cells under CHEK1 overexpression or knockdown conditions was analyzed via Western blotting. Proliferative capacity was assessed using CCK-8 assays in NSCLC cells with modulated CHEK1 expression. Additionally, real-time quantitative PCR was employed to measure CHEK1 and FOXM1 expression levels in NSCLC tissues. The effects of CHEK1 knockdown on tumor growth were further validated in animal models. The binding of FOXM1 to the CHEK1 promoter region was examined using dual-luciferase reporter assays and chromatin immunoprecipitation (ChIP) assays.

RESULTS

FOXM1 and CHEK1 were upregulated in NSCLC tissues. CHEK1 overexpression promoted NSCLC cell proliferation, while its knockdown suppressed proliferation, inhibited EMT, and reduced tumor growth in vivo. FOXM1 was shown to directly bind to CHEK1 promoter, thereby upregulating CHEK1 expression.

CONCLUSION

CHEK1 promotes NSCLC cell proliferation and tumor growth, and its expression is regulated by FOXM1. These findings suggest CHEK1 and FOXM1 are potential therapeutic targets for NSCLC treatment.

Elevated nonhomologous end-joining by AATF enables efficient DNA damage repair and therapeutic resistance in glioblastoma

Glioblastoma (GB) is a highly aggressive brain tumor resistant to chemoradiotherapy, largely due to glioma stem-like cells (GSCs) with robust DNA damage repair capabilities. Here we reveal that GSCs enhance their DNA repair capacity by activating non-homologous end-joining (NHEJ) through upregulation of the apoptosis antagonizing transcription factor (AATF), thereby promoting therapeutic resistance in GB. AATF interacts with XRCC4, a core NHEJ subunit, preventing its degradation via ubiquitin-mediated proteasomal processes. Upon DNA damage, AATF undergoes phosphorylation at Ser189 by ATM, leading to its dissociation from XRCC4 and rapid recruitment of XRCC4 to DNA break sites for efficient NHEJ repair. Moreover, AATF depletion or deficient AATF phosphorylation impedes NHEJ in GSCs, sensitizing GB xenografts to chemoradiotherapy. Additionally, elevated levels of AATF inform poor prognosis in GB patients. Collectively, our findings unveil a crucial role of AATF in XRCC4-mediated NHEJ repair, and underscore targeting AATF as a potential strategy to overcome GB resistance to chemoradiotherapy.

Detection of p53 aggregates in plasma of glioma patients

BACKGROUND

The tumour-suppressor protein p53 can form amyloid aggregates resulting in loss of tumour-suppressing functions and leading to tumour formation. The detection of p53 aggregates in cancer cells has been demonstrated but these aggregates have not been detected in liquid biopsies to date, due to the lack of sufficiently sensitive methods.

METHODS

We developed an ultrasensitive immunoassay based on the single-molecule array (SiMoA) technology to detect p53 aggregates in plasma, based on antibody capture of the aggregates. We confirmed that the assay detects p53 aggregates using super-resolution imaging. We then investigated the p53 aggregate concentrations in the plasma of 190 pre-surgery glioblastoma (GB) patients and 22 controls using this assay.

RESULTS

We found that the plasma p53 aggregate levels are significantly elevated in pre-surgery GB patients' plasma compared to controls. Longitudinal study further reveals that p53 aggregate levels may increase before GB recurrence and decrease following treatment. We also observed raised p53 aggregate concentrations in the plasma of cancer patients with brain metastases.

CONCLUSIONS

This study demonstrates the detection of p53 aggregates in liquid biopsies. Our findings highlight the potential of p53 aggregates as a novel biomarker for glioblastoma.

Targeting Glioblastoma Stem Cells via EphA2: Structural Insights into the RNA Aptamer A40s for Precision Therapy

EphA2 receptor tyrosine kinase is overexpressed in many solid tumors and serves as a key driver of tumorigenesis and metastasis. It is highly expressed in glioblastoma multiforme, the most aggressive brain tumor in adults, and in its stem cells [glioblastoma stem cells (GSCs)], which contribute to treatment resistance and tumor relapse. In a previous study, we used the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) procedure, a method for selecting high-affinity nucleic acids to specific targets via iterative selection and amplification, to identify the 2'-fluorinated EphA2-targeting RNA aptamer A40L and a truncated 30-mer derivative, A40s. Both aptamers were able to inhibit GSC growth, stemness, and migration upon EphA2 binding. Here, by integrating computational and experimental methods, the A40s structure was unraveled and its interaction with EphA2 was investigated. Our model offers a blueprint to accelerate the development of optimized A40s variants, advancing next-generation EphA2-targeted anticancer therapies.

All-Trans Retinoic Acid Induces Differentiation and Downregulates Stemness Markers and MGMT Expression in Glioblastoma Stem Cells

BACKGROUND

Glioblastoma (GBM) remains almost uniformly fatal, owing in part to therapy-resistant cancer stem-like cells (CSCs) and to temozolomide (TMZ) resistance driven by O6-methylguanine-DNA methyltransferase (MGMT). Differentiation therapy with all-trans retinoic acid (ATRA) has the potential to attenuate stemness and sensitize GBM to TMZ. We therefore asked whether ATRA reduces expression of key CSC markers and MGMT in established GBM lines.

METHODS

Two established human GBM cell lines, U87-MG and A172, were cultured under neurosphere-promoting conditions to enrich for potential stem-like subpopulations. Cells were treated with either 1 µM ATRA or vehicle control (DMSO) for 5 days. Total RNA was extracted, and cDNA was synthesized. Quantitative Real-Time PCR (qPCR) assessed relative mRNA expression levels of key stemness transcription factors (SOX2, NES) and the DNA repair gene MGMT and corresponding protein levels were measured by an Enzyme-Linked Immunosorbent Assay (ELISA). Gene expression was normalized to the geometric mean of two validated housekeeping genes (GAPDH, ACTB). Relative quantification was calculated using the ΔΔCt method, and statistical significance was determined using Student's t-tests.

RESULTS

ATRA markedly suppressed stemness and MGMT in both lines. In U87-MG, SOX2 mRNA fell 3.7-fold (p = 0.0008) and protein 2.99-fold (148.3 ± 6.0 → 49.7 ± 2.7 pg µg-1; p = 0.0002); Nestin dropped 4.1-fold (p = 0.0005) and 3.51-fold (450.0 ± 17.3 → 128.3 ± 4.4 pg µg-1; p = 0.00008). MGMT decreased 2.6-fold at transcript level (p = 0.0065) and 2.11-fold at protein level (81.7 ± 4.4 → 38.7 ± 1.8 pg µg-1; p = 0.0005). In A172, SOX2 was reduced 2.9-fold (p = 0.0041) and 2.31-fold (p = 0.0007); Nestin 3.3-fold (p = 0.0028) and 2.79-fold (p = 0.00009). MGMT declined 2.2-fold (p = 0.0132) and 1.82-fold (p = 0.0015), respectively.

CONCLUSIONS

Five-day exposure to ATRA diminishes SOX2, Nestin, and MGMT at both mRNA and protein levels in stem-enriched GBM cultures, supporting the premise that ATRA-induced differentiation can concurrently blunt CSC traits and TMZ-resistance mechanisms. These data provide a molecular rationale for testing ATRA in combination regimens aimed at improving GBM therapy.

Cytoplasmic connexin43-microtubule interactions promote glioblastoma stem-like cell maintenance and tumorigenicity

Glioblastoma (GBM) is the most common primary tumor of the central nervous system. One major challenge in GBM treatment is the resistance to chemotherapy and radiotherapy observed in subpopulations of cancer cells, including GBM stem-like cells (GSCs). These cells have the capacity to self-renew and differentiate and as such, GSCs participate in tumor recurrence following treatment. The gap junction protein connexin43 (Cx43) has complex roles in oncogenesis and we have previously demonstrated an association between Cx43 and GBM chemotherapy resistance. Here, we report, for the first time, increased direct interaction between non-junctional Cx43 and microtubules in the cytoplasm of GSCs. We hypothesize that non-junctional Cx43/microtubule complexing is critical for GSC maintenance and survival and sought to specifically disrupt this interaction while maintaining other Cx43 functions, such as gap junction formation. Using a Cx43 mimetic peptide of the carboxyl terminal tubulin-binding domain of Cx43 (JM2), we successfully disrupted Cx43 interaction with microtubules in GSCs. Importantly, administration of JM2 significantly decreased GSC survival in vitro, and limited GSC-derived and GBM patient-derived xenograft tumor growth in vivo. Together, these results identify JM2 as a novel peptide drug to ablate GSCs in GBM treatment.

Stress-induced pro-inflammatory glioblastoma stem cells secrete TNFAIP6 to enhance tumor growth and induce suppressive macrophages

Glioblastoma (GBM) is the most aggressive primary intracranial tumor, with glioblastoma stem cells (GSCs) enforcing the intratumoral hierarchy. The inflammatory microenvironment influences tumor development at varying stages, while the underlying mechanism of GSCs facing pro-inflammatory stress remains unclear. Here, we show that, in human GBM, pro-inflammatory stress from pro-inflammatory macrophages (pTAMs) maintains GSC proliferation and self-renewal. Tumor necrosis factor alpha-induced protein 6 (TNFAIP6), as a responder in patient-derived GSCs to pro-inflammatory stress tumor necrosis factor alpha (TNF-α) from human pTAMs, promotes tumor growth through binding epidermal growth factor (EGF) and prolonging EGF receptor (EGFR)-phosphatidylinositol 3-kinase (PI3K)-protein kinase B (AKT) signaling activation. Meanwhile, pro-inflammatory stress-induced patient-derived GSCs secrete TNFAIP6 to transform macrophage phenotype from pTAMs to inflammatory-suppressive macrophages (sTAMs). Collectively, pharmacological or genetic disruption of TNFAIP6 autocrine and paracrine communication between patient-derived GSCs and TAMs inhibited GSC proliferation and self-renewal in vitro and in patient-derived xenograft tumor-bearing mice, suggesting that TNFAIP6 is an effective target for GBM therapy.

Targeting the glioblastoma resection margin with locoregional nanotechnologies

Surgical resection is the first stage of treatment for patients diagnosed with resectable glioblastoma and is followed by a combination of adjuvant radiotherapy and systemic single-agent chemotherapy, which is typically commenced 4-6 weeks after surgery. This delay creates an interval during which residual tumour cells residing in the resection margin can undergo uninhibited proliferation and further invasion, even immediately after surgery, thus limiting the effectiveness of adjuvant therapies. Recognition of the postsurgical resection margin and peri-marginal zones as important anatomical clinical targets and the need to rethink current strategies can galvanize opportunities for local, intraoperative approaches, while also generating a new landscape of innovative treatment modalities. In this Perspective, we discuss opportunities and challenges for developing locoregional therapeutic strategies to target the glioblastoma resection margin as well as emerging opportunities offered by nanotechnology in this clinically transformative setting. We also discuss how persistent barriers to clinical translation can be overcome to offer a potential path forward towards broader acceptability of such advanced technologies.

Effects of Integrin-Linked Kinase Silencing Combined With Trichostatin A on Cancer Stem Cells

OBJECTIVES

Oral squamous cell carcinoma (OSCC) is characterized by high invasiveness and metastasis, with cancer stem cells (CSCs) playing a central role in tumor progression. This study investigates the effects of integrin-linked kinase (ILK) silencing and trichostatin A (TSA) treatment on CSCs, assessing their potential to diminish CSC properties and inhibit OSCC progression.

METHODS AND MATERIALS

CSCs were enriched and isolated from primary OSCC samples and Tca8113 cell line and MOC1 cell line using side population (SP) analysis, with their characteristics and the therapeutic impact of treatments assessed through assays such as MTT, wound healing, cell invasion, cell cycle, and apoptosis.

RESULTS

Higher SP cell content correlated significantly with poor pathological classification, metastasis, and recurrence. Treated CSCs showed reduced proliferation, migration, and invasion, along with increased apoptosis. In vivo experiments demonstrated that the combined treatment substantially reduced tumor growth.

CONCLUSION

The study confirms the efficacy of targeting CSCs with ILK silencing and TSA treatment in OSCC, suggesting a promising strategy for CSC-directed therapies that merit further investigation.

Nanoemulsification of PTX and BEZ235 inhibits colon cancer growth

Colorectal cancer is one of the most common malignant tumors, and its drug resistance poses a huge challenge and a serious threat to people's health. In previous studies, we have found that the combination of paclitaxel and BEZ235 has synergistic anti-colon cancer effects, particularly in drug-resistant colorectal cancer, demonstrating excellent anti-tumor effects. Therefore, this study aims to investigate the preparation of the nanoemulsification of paclitaxel and BEZ235 (NEs-PTX-BEZ235) and to explore the potential key parameters for its clinical translation. This study aims to provide a new therapeutic strategy for colorectal cancer, especially for drug-resistant colorectal cancer. The nanomaterials were prepared by low energy self-emulsification method, and analyzed by Malvern laser particle size analyzer. Cell drug uptake was observed under fluorescence microscope. CCK8, Western blot and flow cytometry were used to compare the anti-cancer effects and mechanisms of different experimental groups on ordinary and drug-resistant colon cancer cells. Human colon cancer primary cells were extracted to verify the anti-tumor effect of drugs. Finally, we found that NEs-PTX-BEZ235 significantly killed colon cancer cells, especially drug-resistant cells, and performed better than Nab-PTX. It may play a synergistic role in reducing drug resistance, inhibiting tumor stemness and inducing apoptosis of colon cancer cells by inhibiting drug resistance proteins.

Discovery of a Potent, Selective, and Brain-Penetrant Checkpoint Kinase 1 Inhibitor, BEN-28010, for the Treatment of Glioblastoma

Glioblastoma (GBM) patients face a dire prognosis and alternative therapeutic options are desperately needed. Inhibition of checkpoint kinase 1 (CHK1) represents a potential therapeutic strategy for GBM through regulation of the DNA damage response (DDR) pathway, but no suitable brain-penetrant CHK1 inhibitors have been reported to date. In this study, we disclose the discovery and optimization of clinical candidate 38 (BEN-28010) as a freely brain-penetrant, potent, and selective CHK1 inhibitor, derived from virtual screening hit 1. In vivo pharmacological studies demonstrated efficacy of orally administered 38 in several GBM CDX and PDX models as a monotherapy and in combination with ionizing radiation, including improved overall survival in an intracranially implanted GBM PDX mouse model. Additionally, 38 utilizes an underrepresented aminoimidazole kinase hinge-binding motif that may have broader utility within kinase inhibitor drug discovery.

Targeting Glioma Stem Cells: Therapeutic Opportunities and Challenges

Glioblastoma (GBM), or grade 4 glioma, is the most common and aggressive primary brain tumor in adults with a median survival of 15 months. Increasing evidence suggests that GBM's aggressiveness, invasiveness, and therapy resistance are driven by glioma stem cells (GSCs), a subpopulation of tumor cells that share molecular and functional characteristics with neural stem cells (NSCs). GSCs are heterogeneous and highly plastic. They evade conventional treatments by shifting their state and entering in quiescence, where they become metabolically inactive and resistant to radiotherapy and chemotherapy. GSCs can exit quiescence and be reactivated to divide into highly proliferative tumor cells which contributes to recurrence. Understanding the molecular mechanisms regulating the biology of GSCs, their plasticity, and the switch between quiescence and mitotic activity is essential to shape new therapeutic strategies. This review examines the latest evidence on GSC biology, their role in glioblastoma progression and recurrence, emerging therapeutic approaches aimed at disrupting their proliferation and survival, and the mechanisms underlying their resistance to therapy.

A Positive Feedback DNA-PK/MYT1L-CXCR1-ERK1/2 Proliferative Signaling Loop in Glioblastoma

Glioblastoma is the most common primary brain tumor in adults. Our previous studies revealed a functional interplay of myelin transcription factor 1-like (MYT1L) with the DNA-dependent protein kinase (DNA-PK) in the regulation of p21 transcription. However, the contributing role of this functional interplay in glioblastoma remains largely unknown. Here, we used cell lines with normal DNA-PK (HEK293 and M059K) or deficient DNA-PK (M059J) as a model system to demonstrate the importance of the DNA-PK-dependent activation of MYT1L in controlling the transcription of CXC chemokine receptor 1 (CXCR1) in a positive-feedback proliferative signaling loop in glioblastoma with numerous conventional techniques. In normal DNA-PK cells, MYT1L acted as an oncogene by promoting cell proliferation, inhibiting apoptosis, and shortening a cell cycle S phase. However, in DNA-PK-deficient cells, MYT1L functioned as a tumor suppressor by inhibiting cell proliferation and inducing a G1 arrest. The enforced expression of MYT1L promoted CXCR1 transcription in DNA-PK-normal cells but attenuated transcription in DNA-PK-deficient cells. Bioinformatics analysis predicted a MYT1L-binding sequence at the CXCR1 promoter. The functional dependence of MYT1L on DNA-PK in CXCR1 transcription was validated by luciferase assay. Although the expression of CXCR1 was lower in M059J cells as compared to M059K cells, it was higher than in normal brain tissue. The CXCR1 ligands interleukin 8 (IL-8) and GRO protein alpha (GROα) expressed in M059J and M059K cells may signal through the extracellular signal-regulated kinase 1/2 (ERK1/2) pathway that can be blocked by CXCR1 siRNA. Our findings demonstrate the existence of a positive feedback DNA-PK/MYT1L-CXCR1-ERK1/2 proliferation loop in glioblastoma cells that may represent a pharmacological target loop for therapeutic intervention.

Raman spectroscopies for cancer research and clinical applications: a focus on cancer stem cells

Over the last 2 decades, research has increasingly focused on cancer stem cells (CSCs), considered responsible for tumor formation, resistance to therapies, and relapse. The traditional "static" CSC model used to describe tumor heterogeneity has been challenged by the evidence of CSC dynamic nature and plasticity. A comprehensive understanding of the mechanisms underlying this plasticity, and the capacity to unambiguously identify cancer markers to precisely target CSCs are crucial aspects for advancing cancer research and introducing more effective treatment strategies. In this context, Raman spectroscopy (RS) and specific Raman schemes, including CARS, SRS, SERS, have emerged as innovative tools for molecular analyses both in vitro and in vivo. In fact, these techniques have demonstrated considerable potential in the field of cancer detection, as well as in intraoperative settings, thanks to their label-free nature and minimal invasiveness. However, the RS integration in pre-clinical and clinical applications, particularly in the CSC field, remains limited. This review provides a concise overview of the historical development of RS and its advantages. Then, after introducing the CSC features and the challenges in targeting them with traditional methods, we review and discuss the current literature about the application of RS for revealing and characterizing CSCs and their inherent plasticity, including a brief paragraph about the integration of artificial intelligence with RS. By providing the possibility to better characterize the cellular diversity in their microenvironment, RS could revolutionize current diagnostic and therapeutic approaches, enabling early identification of CSCs and facilitating the development of personalized treatment strategies.

Efficacy of MET-targeting CAR T cells against glioblastoma patient-derived xenograft models

BACKGROUND

Genetic alteration of the MET receptor tyrosine kinase frequently occurs in glioblastoma (GBM). Clinically, bevacizumab treatment results in MET signaling activation, leading to GBM recurrence with a more malignant phenotype. While MET has been a promising therapeutic target, MET inhibitors have not been successful in treating GBM patients. MET-directed chimeric antigen receptor (CAR) T cells hold the promise of targeting MET-positive GBM regardless of genetic alterations or kinase activity.

METHODS

GBM patient-derived xenografts (PDX) harboring MET amplification (METamp) or PTPRZ-MET fusion (ZM) were propagated in vivo followed by glioma stem cell (GSC) isolation. Cell-based assays were used for comparing GSC survival in response to MET inhibitors and CAR T cells. Multi-panel cytokine release was analyzed to profile MET-CAR T cell activation during co-culture with GBM. Orthotopic tumor growth and real-time imaging were performed to evaluate MET-CAR T cell therapeutic efficacy in vivo.

RESULTS

Although GBM are heterogeneous tumors, neuro-sphere cells isolated from METamp or ZM fusion PDX tumors showed universal cognate genetic MET alteration along with GSC markers such as SOX2 and nestin. Both METamp and ZM fusion tumors showed MET overexpression but only the METamp cells presented activated MET signaling which was vulnerable to MET inhibitors. In contrast, MET-CAR T cells specifically inhibited all MET-positive tumor growth regardless of MET activation status.

CONCLUSIONS

Whereas MET inhibitors are effective in MET-active tumors, MET-CAR T cells eradicate MET-positive GBM growth in an antigen-dependent manner, demonstrating a promising therapeutic approach for treating MET-positive GBM. MET overexpression, especially METamp and ZM fusion may be used to predefine the GBM patients for treating with MET-CAR T cell therapy.

RSK2-mediated phosphorylation and degradation of UBE2O inhibits hepatocellular carcinoma growth and resistance to radiotherapy

Radioresistance poses the main challenge in radiation therapy (RT) for liver cancer, with the DNA Damage response (DDR) being a crucial component of this resistance. Ubiquitin-conjugating enzyme E2O (UBE2O) has been implicated in regulating tumor proliferation, cholesterol metabolism, and drug resistance. However, the role of the ubiquitin-conjugating enzyme E2O (UBE2O) in DDR of liver cancer remains to be fully explored. We discovered an elevated expression of UBE2O within liver cancer tissues, which was notably associated with unfavorable prognoses in hepatocellular carcinoma (HCC) patients. Furthermore, we found that the suppression of UBE2O can effectively reduce the growth and resistance to radiotherapy of HCC cells in vitro and in vivo. Moreover, p90 ribosomal S6 kinase2 (RSK2) was confirmed as a novel interacting kinase of UBE2O, which mediated the phosphorylation and degradation of UBE2O at the Thr838 site. RSK2 inhibition promotes tumor proliferation and resistance to radiotherapy of HCC cells in vitro and in vivo, and these effects are abrogated upon UBE2O knockdown. Collectively, our work revealed that UBE2O promotes tumor progression and resistance to radiotherapy, which was negatively regulated by RSK2 for phosphorylation and degradation, indicating that the RSK2/UBE2O axis provides a potential radiosensitization target for HCC patients.

Glioblastoma Stem Cells at the Nexus of Tumor Heterogeneity, Immune Evasion, and Therapeutic Resistance

Glioblastoma (GBM) is an exceedingly aggressive primary brain tumor defined by rapid growth, extensive infiltration, and resistance to standard therapies. A central factor driving these malignancies is the subpopulation of glioblastoma stem cells (GSCs), which possess self-renewal capacity, multipotency, and the ability to regenerate tumor heterogeneity. GSCs contribute to key hallmarks of GBM pathobiology, including relentless progression, resistance to chemotherapy and radiotherapy, and inevitable recurrence. GSCs exhibit distinct molecular signatures, enhanced DNA repair, and metabolic adaptations that protect them against conventional treatments. Moreover, they reside within specialized niches-such as perivascular or hypoxic microenvironments-that sustain stemness, promote immunosuppression, and facilitate angiogenesis. Recent discoveries highlight signaling pathways like Notch, Wnt/β-catenin, Hedgehog, STAT3-PARN, and factors such as TFPI2 and HML-2 as critical regulators of GSC maintenance, plasticity, and immune evasion. These findings underscore the complexity of GSC biology and their pivotal role in driving GBM heterogeneity and therapeutic failure. Emerging therapeutic strategies aim to target GSCs through multiple avenues, including surface markers, immunotherapeutics (e.g., CAR T cells), metabolic vulnerabilities, and combination regimens. Advances in patient-derived organoids, single-cell omics, and 3D co-culture models enable more accurate representation of the tumor ecosystem and personalized therapeutic approaches. Ultimately, improved understanding of GSC-specific targets and the tumor microenvironment promises more effective interventions, paving the way toward better clinical outcomes for GBM patients.

The Mevalonate Pathway in the Radiation Response of Cancer

The mevalonate (MVA) pathway plays a critical role in cholesterol biosynthesis, protein prenylation, and metabolic reprogramming, all of which contribute to cancer progression and therapy resistance. Targeting the MVA pathway with statins and other inhibitors has shown promise in preclinical studies; however, clinical outcomes remain controversial, raising concerns about translating these findings into effective treatments. Additionally, the interaction between the MVA pathway and radiation therapy (RT) is not yet fully understood, as RT upregulates the pathway, which can enhance tumor cell survival. This review summarizes the current literature on MVA pathway inhibition in cancer therapy, focusing on its potential to enhance the efficacy of RT. A better understanding of the pathway's role in radiation responses will be essential to translate combination therapies that target this pathway.

Silver nanoparticles enhance neutron radiation sensitivity in cancer cells: An in vitro study

Growing interest in cancer radiotherapy has led to the application of nanoparticles as radiosensitizers. Here, we, for the first time, present the results of the radiosensitizing properties of silver nanoparticles (AgNPs) (possessing low toxicity towards human body) against cancer cells under neutron irradiation. Five standard cancer cultures (including glioblastoma, known for its resistance to conventional photon radiation) were used to evaluate the radiosensitizing properties of AgNPs suing MTT test, flow cytometry, and optical fluorescence microscopy. Neutron irradiation was applied in the absorbed dose of 0.5-1.5 Gy with an average neutron energy of 7.5 MeV. AgNPs increased the irradiation efficiency with the radiosensitivity enhancement ratios 1.02-2.32, for glioblastoma with ratios 1.22-1.47. It was revealed that at 1.5 Gy, AgNP-induced cytotoxicity made a significant contribution to the total observed radiosensitizer effect: on average, for five cell types, 29.8 and 96.2 % at the AgNP concentration of 0.2 and 1.6 μg/mL, respectively.

(-)-Epicatechin regulates the resistance of lung adenocarcinoma cells to radiotherapy through the downregulation of FOXM1

Radioresistance, particularly as manifested by cancer stem cells (CSCs), is the most common reason for the failure of cancer radiotherapy. It is essential for effective radiotherapy to inhibit cancer cell stemness. Research indicates that (-)-epicatechin (EC) enhances the radiosensitivity of non-small cell lung cancer (NSCLC); however, its influence on cell stemness in lung adenocarcinoma (LUAD) resistant to radiotherapy is still not well understood. In this study, radioresistant cell lines A549R and H1299R were constructed by repeatedly irradiating A549 and H1299 cells with gradient doses of X-rays. CCK-8, cell cloning, flow cytometry, RT-qPCR, Western blot, sphere formation detection, and other methods were used for experimental exploration. This study revealed that the radioresistance of LUAD cells was related to their stemness. By inhibiting KLF4, SOX2, CD133, and ALDH1A1 expression, EC treatment increased radiosensitivity and reduced cell sphere formation. Also, FOXM1 expression was upregulated in LUAD and in radioresistant LUAD cells. Knocking down FOXM1 inhibited the stemness of radioresistant LUAD cells. Mechanistically, EC inhibited radiotherapy-resistant LUAD cell stemness by downregulating FOXM1 expression, thereby increasing radiosensitivity. In summary, our study revealed that EC inhibited radiotherapy resistance in LUAD cells through downregulating FOXM1, and it provides a theoretical framework for treating LUAD clinically.

Transitioning from molecular methods to therapeutic methods: An in‑depth analysis of glioblastoma (Review)

Glioblastoma (GBM) is the most aggressive primary brain tumour, characterised by high heterogeneity, aggressiveness and resistance to conventional therapies, leading to poor prognosis for patients. In recent years, with the rapid development of molecular biology and genomics technologies, significant progress has been made in understanding the molecular mechanisms of GBM. This has revealed a complex molecular network involving aberrant key signalling pathways, epigenetic alterations, interactions in the tumour microenvironment and regulation of non‑coding RNAs. Based on these molecular features, novel therapeutic strategies such as targeted therapies, immunotherapy and gene therapy are rapidly evolving and hold promise for improving the outcome of GBM. This review systematically summarises the advances in molecular mechanisms and therapeutic approaches for GBM. It aims to provide new perspectives for the precise diagnosis and personalised treatment of GBM, and to ultimately improve the prognosis of patients.

Cancer stem cells in meningiomas: novel insights and therapeutic implications

Meningiomas (MGs), which arise from meningothelial cells of the dura mater, represent a significant proportion of primary tumours of the central nervous system (CNS). Despite advances in treatment, the management of malignant meningioma (MMG) remains challenging due to diagnostic, surgical, and resection limitations. Cancer stem cells (CSCs), a subpopulation within tumours capable of self-renewal and differentiation, are highlighted as key markers of tumour growth, metastasis, and treatment resistance. Identifying additional CSC-related markers enhances the precision of malignancy evaluations, enabling advancements in personalised medicine. The review discusses key CSC biomarkers that are associated with high levels of expression, aggressive tumour behaviour, and poor outcomes. Recent molecular research has identified CSC-related biomarkers, including Oct-4, Sox2, NANOG, and CD133, which help maintain cellular renewal, proliferation, and drug resistance in MGs. This study highlights new therapeutic strategies that could improve patient prognosis with more durable tumour regression. The use of combination therapies, such as hydroxyurea alongside diltiazem, suggests more efficient and effective MG management compared to monotherapy. Signalling pathways such as NOTCH and hedgehog also offer additional avenues for therapeutic development. CRISPR/Cas9 technology has also been employed to create meningioma models, uncovering pathways related to cell growth and proliferation. Since the efficacy of traditional therapies is limited in most cases due to resistance mechanisms in CSCs, further studies on the biology of CSCs are warranted to develop therapeutic interventions that are likely to be effective in MG. Consequently, improved diagnostic approaches may lead to personalised treatment plans tailored to the specific needs of each patient.

PEA3 Transcription Factors, Role in Invasion, Proliferation and Radioresistance of Glioblastoma Stem Cells

The presence of glioblastoma stem cells (GSCs), known for their high invasiveness and resistance to radiation, is one of the reasons for systematic recurrence. It is therefore important to understand the resistance mechanisms of these cells to optimise therapies. We focused on the PEA3 family of transcription factors, ETV1, ETV4 and ETV5, in patient-derived GSCs. We demonstrate that ETV1 is over-expressed in high invasive GSCs. In 3D invasion assays, inhibiting ETV1 expression using specific siRNAs significantly reduces cell invasion. Furthermore, we show a significant correlation between ETV1 and ZEB1, a major driver of invasion. Blocking ETV1 decreases ZEB1 expression in GSCs. The study also demonstrates the essential role of ETV1, ETV4 and ETV5 in the radioresistance of GSCs and their ability to form neurospheres. Using specific siRNAs to inhibit the expression of these transcription factors led to an increased sensitivity of GSCs to radiation and a decrease in both the number and size of neurospheres. These findings suggest that PEA3 transcription factors play a major role in GSCs aggressiveness by regulating invasion, radioresistance and the ability to form neurospheres. Trial Registration: Registry and the Registration N° of the study/trial: 12TETE01, ID-RCB No. 2012-A00585-38, approval Date: May 7, 2012.

All-stage targeted nanodiscs for glioma treatment by inducing cuproptosis and apoptosis of cancer cells and cancer stem cells

There remain several intractable challenges for chemotherapy in glioma treatment, including the blood-brain barrier (BBB), blood-brain tumor barrier (BBTB), and tumor heterogeneity caused by cancer stem cells (CSCs), which are resistant to conventional chemotherapy. Here, we established a nano strategy to kill glioma cells and CSCs, combining carfilzomib and bis(diethyldithiocarbamate)copper. The synergistic drug combination disturbed cell protein metabolism at different stages and induced apoptosis and cuproptosis. The Y-shaped targeting ligand pHA-VAP-modified nanodiscs were designed to help the chemotherapeutic agents cross the BBB/BBTB and finally accumulate in tumor site. This all-stage targeting and all-stage treatment nanomedicine significantly prolonged the survival in glioma-bearing mice and might inspire the rational design of advanced drug delivery platforms.

Challenges and Emerging Strategies of Immunotherapy for Glioblastoma

Glioblastoma (GBM) is recognized as the most lethal primary malignant tumor of the central nervous system. Although traditional treatments can somewhat prolong patient survival, the overall prognosis remains grim. Immunotherapy has become an effective method for GBM treatment. Oncolytic virus, checkpoint inhibitors, CAR T cells and tumor vaccines have all been applied in this field. Moreover, the combining of immunotherapy with traditional radiotherapy, chemotherapy, or gene therapy can further improve the treatment outcome. This review systematically summarizes the features of GBM, the recent progress of immunotherapy in overcoming GBM.

D-bait: A siDNA for regulation of DNA-protein kinases against DNA damage and its implications in cancer

siDNA fragments, also called Dbait and Pbait, are small DNA oligonucleotides of 30-32 base pairs that cause impairment in DNA repair pathways. Like siRNA and miRNA molecules, which lead to the degradation of mRNA molecules through the Argonaute and Drosha machinery, respectively, Dbait molecules act as false DNA damage signals and trigger and exhaust the DNA repair machinery. In normal cells with no significant DNA damage, the influence of these molecules is negligible. However, in cancer, when there is heavy DNA damage due to replication and anticancer therapies, the cancer cell is heavily dependent on DNA repair proteins to keep the genome intact and limit breaks. This phenomenon primarily occurs during radiation therapy, as significant DNA damage surpasses several DNA repair mechanisms, causing an accumulation of unrepaired lesions and ultimately leading to cell death. This review explores the therapeutic capacity of siDNA molecules in cancer treatment by stimulating the repair mechanisms in cells that depend on DNA repair pathways. For aggressive malignancies such as glioblastoma, prostate cancer, and colorectal cancer, the use of siDNA as a radiosensitizer, especially when combined with other treatments, increases the vulnerability of tumor cells to radiation-induced DNA damage, hence potentially enhancing therapy results.

Changes in adrenoceptor expression level contribute to the cellular plasticity of glioblastoma cells

Glioblastoma cells are known to regulate their cellular plasticity in response to their surrounding microenvironment, but it is not fully understood what factors contribute to the cells' changing plasticity. Here, we found that glioblastoma cells alter the expression level of adrenoreceptors depending on their differentiation stage. Catecholamines are abundant in the central nervous system, and we found that noradrenaline, in particular, enhances the stemness of glioblastoma cells and promotes the dedifferentiation potential of already differentiated glioblastoma cells. Antagonist and RNAi experiments revealed that signaling through α1D-adrenoreceptor is important for noradrenaline action on glioblastoma cells. We also found that high α1D-adrenoreceptor expression was associated with poor prognosis in patients with gliomas. These data suggest that glioblastoma cells increase the expression level of their own adrenoreceptors to alter the surrounding tumor microenvironment favorably for survival. We believe that our findings will contribute to the development of new therapeutic strategies for glioblastoma.

Therapeutic Targets in Glioblastoma: Molecular Pathways, Emerging Strategies, and Future Directions

Glioblastoma (GBM) is the most aggressive primary brain tumor in adults, characterized by rapid growth, invasive infiltration into surrounding brain tissue, and resistance to conventional therapies. Despite advancements in surgery, radiotherapy, and chemotherapy, median survival remains approximately 15 months, underscoring the urgent need for innovative treatments. Key considerations informing treatment development include oncogenic genetic and epigenetic alterations that may dually serve as therapeutic targets and facilitate treatment resistance. Various immunotherapeutic strategies have been explored and continue to be refined for their anti-tumor potential. Technical aspects of drug delivery and blood-brain barrier (BBB) penetration have been addressed through novel vehicles and techniques including the incorporation of nanotechnology. Molecular profiling has emerged as an important tool to individualize treatment where applicable, and to identify patient populations with the most drug sensitivity. The goal of this review is to describe the spectrum of potential GBM therapeutic targets, and to provide an overview of key trial outcomes. Altogether, the progress of clinical and preclinical work must be critically evaluated in order to develop therapies for GBM with the strongest therapeutic efficacy.

Combined targeting of glioblastoma stem cells of different cellular states disrupts malignant progression

Glioblastoma (GBM) is the most lethal primary brain tumor with intra-tumoral hierarchy of glioblastoma stem cells (GSCs). The heterogeneity of GSCs within GBM inevitably leads to treatment resistance and tumor recurrence. Molecular mechanisms of different cellular state GSCs remain unclear. Here, we find that classical (CL) and mesenchymal (MES) GSCs are enriched in reactive immune region and high CL-MES signature informs poor prognosis in GBM. Through integrated analyses of GSCs RNA sequencing and single-cell RNA sequencing datasets, we identify specific GSCs targets, including MEOX2 for the CL GSCs and SRGN for the MES GSCs. MEOX2-NOTCH and SRGN-NFκB axes play important roles in promoting proliferation and maintaining stemness and subtype signatures of CL and MES GSCs, respectively. In the tumor microenvironment, MEOX2 and SRGN mediate the resistance of CL and MES GSCs to macrophage phagocytosis. Using genetic and pharmacologic approaches, we identify FDA-approved drugs targeting MEOX2 and SRGN. Combined CL and MES GSCs targeting demonstrates enhanced efficacy, both in vitro and in vivo. Our results highlighted a therapeutic strategy for the elimination of heterogeneous GSCs populations through combinatorial targeting of MEOX2 and SRGN in GSCs.

Histone lactylation enhances GCLC expression and thus promotes chemoresistance of colorectal cancer stem cells through inhibiting ferroptosis

Colorectal cancer stem cells (CCSCs) play a critical role in mediating chemoresistance. Lactylation is a post-translational modification induced by lactate that regulates gene expression. However, whether lactylation affects the chemoresistance of CCSCs remains unknown. Here, we demonstrate that histone lactylation enhances CCSC chemoresistance both in vitro and in vivo. Furthermore, our findings showed that p300 catalyzes the lactylation of histone H4 at K12, whereas HDAC1 facilitates its delactylation in CCSCs. Notably, lactylation at H4K12 (H4K12la) upregulates GCLC expression and inhibits ferroptosis in CCSCs, and the inhibition of p300 or LDHA decreases H4K12la levels, thereby increasing the chemosensitivity of CCSCs. Additionally, the GCLC inhibitor BSO promotes ferroptosis and sensitizes CCSCs to oxaliplatin. Taken together, these findings suggest that histone lactylation upregulates GCLC to inhibit ferroptosis signaling, thus enhancing CCSC chemoresistance. These findings provide new insights into the relationship between cellular metabolism and chemoresistance and suggest potential therapeutic strategies targeting p300, LDHA, and GCLC. We showed that histones H4K12 lactylation promoted chemoresistance in CSCs. p300 catalyzes the lactylation of histone H4 at K12, HDAC1 inhibits the histone lactylation at the same site. H4K12la in CSCs regulates the expression of the ferroptosis-related gene GCLC, thereby inhibiting ferroptosis and leading to chemoresistance. Targeting the p300, LDHA, or GCLC may be overcome tumor chemoresistance.

PHGDH activation fuels glioblastoma progression and radioresistance via serine synthesis pathway

BACKGROUND

Glioma stem-like cells (GSCs) are key drivers of treatment resistance and recurrence in glioblastoma (GBM). Phosphoglycerate dehydrogenase (PHGDH), a crucial enzyme in the de novo serine synthesis pathway (SSP), is implicated in tumorigenesis and therapy resistance across various cancers. However, its specific role in GBM, particularly in radioresistance, remains poorly understood.

METHODS

In silico analysis of GBM patient data assessed SSP enrichment and PHGDH expression linked with tumor stemness. Comparative gene expression analysis focused on PHGDH in paired GBM specimens and GSCs. Genetic and pharmacological loss-of-function assays were performed in vitro and in vivo to evaluate PHGDH's impact on GSC self-renewal and malignant progression. Comprehensive transcriptomic and metabolomic analyses, along with chromatin immunoprecipitation, mass spectrometry, and various other biochemical assays, were used to elucidate PHGDH-mediated mechanisms in GBM progression and radioresistance.

RESULTS

PHGDH expression is significantly elevated in GSCs, associated with aggressive glioma progression and poor clinical outcomes. PHGDH activation enhances GSC self-renewal by regulating redox homeostasis, facilitating one-carbon metabolism, and promoting DNA damage response via SSP activation. Importantly, MYC was identified as a crucial transcriptional regulator of PHGDH expression. Furthermore, genetic ablation or pharmacological inhibition of PHGDH markedly reduced tumor growth and increased tumor sensitivity to radiotherapy, thereby improving survival outcomes in orthotopic GSC-derived and patient-derived GBM xenograft models.

CONCLUSIONS

This study underscores the pivotal role of MYC-mediated PHGDH activation in driving GSC malignant progression and radioresistance in GBM. Targeting PHGDH presents a promising approach to enhance radiotherapy efficacy in GBM patients.

Developing and validating a prognostic disulfidptosis-related signature for glioblastoma: predicting radioresistance and synergestic effect with immunotherapy

BACKGROUND

Programmed cell death (PCD) modulated radioresistance is one of the predominant causes of treatment failure in glioblastoma (GBM). Disulfidptosis, a newly discovered form of PCD, plays a crucial role in GBM progression. However, the association among disulfidptosis, radiosensitivity and radiotherapy (RT) in GBM remain unclear.

METHODS

We systematically analyzed disulfidptosis-related genes in 1075 GBM patients and constructed a disulfidptosis-related gene signature (DRS). Correlations among the DRS, patient prognosis and immune microenvironment were fully explored. The effects of DRS and EFEMP2 on radiotherapy efficacy were investigated via single cell sequencing analysis and validated via in vitro and in vivo experiments.

RESULTS

The DRS was identified as a robust and independent prognostic biomarker for GBM by multivariate Cox regression analysis, receiver operating characteristic (ROC) curve analysis and decision curve analysis (DCA) in multiple cohorts. High DRS is characterized by radioresistance, and EFEMP2 was proven to be the key gene involved in this process by single cell sequencing analysis, CCK-8 assay and a clonogenic survival assay. In high-DRS patients, the cancer-immunity cycle is attenuated because the antitumor cytotoxicity of CD8+ T cells is inhibited by immune checkpoints. Preclinically, the overexpression of EFEMP2 induced radioresistance and enhancing the efficacy of programmed cell death ligand-1 (PD-L1) blockade in GL261-bearing mice. The combination of irradiation and anti-PD-L1 therapy had a synergistic effect on GBM murine models in which EFEMP2 was overexpressed.

CONCLUSION

Our study bioinformatically and experimentally reveals the molecular landscape of disulfidptosis in GBM, develops a predictive signature for predicting prognosis as well as radioresistance, and provides a synergistic treatment that combines radiotherapy with immunotherapy for radioresistant GBM patients with high DRS or EFEMP2 expression.

SUV39H1 maintains cancer stem cell chromatin state and properties in glioblastoma

Glioblastoma (GBM) is the most lethal brain cancer, with GBM stem cells (GSCs) driving therapeutic resistance and recurrence. Targeting GSCs offers a promising strategy for preventing tumor relapse and improving outcomes. We identify SUV39H1, a histone-3, lysine-9 methyltransferase, as critical for GSC maintenance and GBM progression. SUV39H1 is upregulated in GBM compared with normal brain tissues, with single-cell RNA-seq showing its expression predominantly in GSCs due to super-enhancer-mediated activation. Knockdown of SUV39H1 in GSCs impaired their proliferation and stemness. Whole-cell RNA-seq analysis revealed that SUV39H1 regulates G2/M cell cycle progression, stem cell maintenance, and cell death pathways in GSCs. By integrating the RNA-seq data with ATAC-seq data, we further demonstrated that knockdown of SUV39H1 altered chromatin accessibility in key genes associated with these pathways. Chaetocin, an SUV39H1 inhibitor, mimics the effects of SUV39H1 knockdown, reducing GSC stemness and sensitizing cells to temozolomide, a standard GBM chemotherapy. In a patient-derived xenograft model, targeting SUV39H1 inhibits GSC-driven tumor growth. Clinically, high SUV39H1 expression correlates with poor glioma prognosis, supporting its relevance as a therapeutic target. This study identifies SUV39H1 as a crucial regulator of GSC maintenance and a promising therapeutic target to improve GBM treatment and patient outcomes.

Prospective longitudinal analysis of physiologic MRI-based tumor habitat predicts short-term patient outcomes in IDH-wildtype glioblastoma

BACKGROUND

This study validates MRI-based tumor habitats in predicting time-to-progression (TTP), overall survival (OS), and progression sites in isocitrate dehydrogenase (IDH)-wildtype glioblastoma patients.

METHODS

Seventy-nine patients were prospectively enrolled between January 2020 and June 2022. MRI, including diffusion-weighted and dynamic susceptibility contrast imaging, were obtained immediately postoperation and at three serial timepoints. Voxels from cerebral blood volume and apparent diffusion coefficient maps were grouped into three habitats (hypervascular cellular, hypovascular cellular, and nonviable tissue) using k-means clustering. Predefined cutoffs for increases in hypervascular and hypovascular cellular habitat were applied to calculate the habitat risk score. Associations between spatiotemporal habitats, habitat risk score, TTP, and OS were investigated using Cox proportional hazards modeling. Habitat risk score was compared to tumor volume using time-dependent receiver operating characteristics analysis. Progression sites were matched with spatial habitats.

RESULTS

Increases in hypervascular and hypovascular cellular habitats and habitat risk scores were associated with shorter TTP and OS (all P < .05). Hypovascular cellular habitat and habitat risk scores 1 and 2 independently predicted TTP (hazard ratio [HR], 4.14; P = .03, HR, 4.51; P = .001 and HR, 10.02; P < .001, respectively). Hypovascular cellular habitat and habitat risk score 2 independently predicted OS (HR, 4.01, P = .003; and HR, 3.27, P < .001, respectively). Habitat risk score outperformed tumor volume in predicting TTP (12-month AUC, 0.762 vs. 0.646, P = .048). Hypovascular cellular habitat predicted progression sites (mean Dice index: 0.31).

CONCLUSIONS

Multiparametric physiologic MRI-based spatiotemporal tumor habitats and habitat risk scores are useful biomarkers for early tumor progression and outcomes in IDH-wildtype glioblastoma patients.

Targeting GOLPH3L improves glioblastoma radiotherapy by regulating STING-NLRP3-mediated tumor immune microenvironment reprogramming

Radiotherapy (RT) has been the standard-of-care treatment for patients with glioblastoma (GBM); however, the clinical effectiveness is hindered by therapeutic resistance. Here, we demonstrated that the tumor immune microenvironment (TIME) exhibited immunosuppressive properties and high expression of Golgi phosphoprotein 3 like (GOLPH3L) in RT-resistant GBM. Our study showed that GOLPH3L interacted with stimulator of interferon genes (STING) at the aspartic acid residue 184 in Golgi after RT, leading to coat protein complex II-mediated retrograde transport of STING from Golgi to endoplasmic reticulum. This suppressed the STING-NOD-like receptor thermal protein domain associated protein 3 (NLRP3)-mediated pyroptosis, resulting in suppressive TIME, driving GBM resistance to RT. Genetic GOLPH3L ablation in RT-resistant GBM cells augmented antitumor immunity and overcame tumor resistance to RT. Moreover, we have identified a small molecular inhibitor of GOLPH3L, vitamin B5 calcium (VB5), which improved the therapeutic efficacy of RT and immune checkpoint blockade by inducing a robust antitumor immune response in mouse models. Clinically, patients with GBM treated with VB5 exhibited improved responses to RT. Thus, reprogramming the TIME by targeting GOLPH3L may offer a potential opportunity to improve RT in GBM.

Radiation-induced cellular plasticity primes glioblastoma for forskolin-mediated differentiation

Glioblastoma (GBM) is the deadliest brain cancer in adults, and all patients succumb to the tumor. While surgery followed by chemoradiotherapy delays disease progression, these treatments do not lead to tumor control, and targeted therapies or biologics have failed to further improve survival. Utilizing a transient radiation-induced state of multipotency, we used the adenylcyclase activator forskolin to alter the fate of irradiated glioma cells. The effects of the combined treatment on neuronal marker expression, cell cycle distribution, and proliferation were studied. Gene expression profiling was conducted using bulk RNA-seq. Changes in cell populations were investigated using single-cell RNA-seq. Effects on glioma stem cells (GSCs) were studied in extreme limiting dilution assays, and the effects on median survival were studied in both syngeneic and PDOX mouse models of GBM. The combined treatment induced the expression of neuronal markers in glioma cells, reduced proliferation, and led to a distinct gene expression profile. scRNA-seq revealed that the combined treatment forced glioma cells into a microglia- and neuron-like phenotype. In vivo, this treatment led to a loss of GSCs and prolonged median survival. Collectively, our data suggest that revisiting a differentiation therapy with forskolin in combination with radiation could lead to clinical benefit.

DOT1L Mediates Stem Cell Maintenance and Represents a Therapeutic Vulnerability in Cancer

Tumor-initiating cancer stem cells (CSC) pose a challenge in human malignancies as they are largely treatment resistant and can seed local recurrence and metastasis. Epigenetic mechanisms governing cell fate decisions in embryonic and adult stem cells are deregulated in CSCs. This review focuses on the methyltransferase disruptor of telomeric silencing protein 1-like (DOT1L), which methylates histone H3 lysine 79 and is a key epigenetic regulator governing embryonic organogenesis and adult tissue stem cell maintenance. DOT1L is overexpressed in many human malignancies, and dysregulated histone H3 lysine 79 methylation is pathogenic in acute myeloid leukemia and several solid tumors. DOT1L regulates core stem cell genes governing CSC self-renewal, tumorigenesis, and multidrug resistance. Recent work has situated DOT1L as an attractive stem cell target in cancer. These reports showed that DOT1L is overexpressed and its protein activated specifically in malignant stem cells compared with bulk tumor cells, making them vulnerable to DOT1L inhibition in vitro and in vivo. Although early DOT1L inhibitor clinical trials were limited by inadequate drug bioavailability, accumulating preclinical data indicate that DOT1L critically regulates CSC self-renewal and might be more effective when given with other anticancer therapies. The appropriate combinations of DOT1L inhibitors with other agents and the sequence and timing of drug delivery for maximum efficacy warrant further investigation.

Killing the killers: Natural killer cell therapy targeting glioma stem cells in high-grade glioma

High-grade gliomas (HGGs), including glioblastoma (GBM) in adults and diffuse intrinsic pontine glioma (DIPG) in children, are among the most aggressive and deadly brain tumors. A key factor in their resilience is the presence of glioma stem cells (GSCs), which drive tumor initiation, progression, and resistance to treatment. Targeting and eradicating GSCs holds potential for curing both GBM and DIPG. Natural killer (NK) cells, as part of the innate immune system, naturally recognize and destroy malignant cells. Recent advances in NK cell-based therapies, such as chimeric antigen receptor (CAR)-NK cells, NK cell engagers, and NK cell-derived exosomes, offer promising approaches for treating GBM and DIPG, particularly by addressing the persistence of GSCs. This review highlights these advancements, explores challenges such as the blood-brain barrier and the immunosuppressive tumor microenvironment, and proposes future directions for improving and clinically advancing these NK cell-based therapies for HGGs.

SOX2 promotes the glycolysis process to accelerate cervical cancer progression by regulating the expression of HK2

BACKGROUND

Cervical cancer is a major health burden in females worldwide, available studies indicated that sex-determining region Y-box 2 (SOX2) is closely related to the malignant phenotypes of multiple cancers including cervical cancer. However, the underlying mechanisms were blurred.

EXPERIMENTAL PROCEDURES

A bioinformatics analysis was conducted to investigate the clinical correlation between SOX2 and cervical cancer. Transient transfection and lentivirus infection were utilized to achieve overexpression and knockdown of SOX2, respectively. The role of SOX2 in cervical cancer was confirmed by transwell and colony-forming assays. Immunoblot, dual-luciferase reporter, chromatin immunoprecipitation (ChIP), and biochemical experiments were employed. In addition, the xenograft models and immunohistochemistry (IHC) experiments were performed to validate the findings in vivo.

RESULTS

The expression of SOX2 was significantly positively associated with the cell migration, invasion, and colony-forming abilities of cervical cancer cells. The following immunoblots revealed that the SOX2-induced malignant phenotypes might be related to the glycolysis process, since overexpressing SOX2 significantly promoted the hexokinase 2 (HK2) and glucose transporter-1 (GLUT1) expression, and increased the content of glucose and lactic acid. The further dual-luciferase reporter and ChIP experiments confirmed a binding relationship between SOX2 and HK2 promoter. More importantly, overexpressing SOX2 promoted tumor growth concomitant with a hyper-expression of HK2 and GLUT1 in xenograft tumor tissues, yet the treatment of glycolysis inhibitor significantly reversed those outcomes.

CONCLUSION

SOX2 promotes the malignant progression of cervical cancer by facilitating glycolysis.

Malformin C preferentially kills glioblastoma stem-like cells via concerted induction of proteotoxic stress and autophagic flux blockade

Glioblastoma is a highly aggressive brain tumor for which there is no cure. The dire prognosis of this disease is largely attributable to a high level of heterogeneity, including the presence of a subpopulation of tumor-initiating glioblastoma stem-like cells (GSCs), which are refractory to chemo- and radiotherapy. Here, in an unbiased marine-derived fungal extract screen, together with bioguided dereplication based on high-resolution mass spectrometry, we identified malformin C to preferentially induce cell death in patient-derived GSCs and explore the potential of this cyclic peptide as a therapeutic agent for glioblastoma. Malformin C significantly reduced tumor growth in an in vivo xenograft model of glioblastoma. Using transcriptomics and chemoproteomics, we found that malformin C binds to many proteins, leading to their aggregation, and rapidly induces the unfolded protein response, including autophagy, in GSCs. Crucially, chemical inhibition of translation using cycloheximide rescued malformin C-induced cell death in GSCs, demonstrating that the proteotoxic effect of the compound is necessary for its cytotoxicity. At the same time, malformin C appears to accumulate in lysosomes, disrupting autophagic flux, and driving cells to death. Supporting this, malformin C synergizes with chloroquine, an inhibitor of autophagy. Strikingly, we observed that autophagic flux is differentially regulated in GSCs compared with normal astrocytes. The sensitivity of GSCs to malformin C highlights the relevance of proteostasis and autophagy as a therapeutic vulnerability in glioblastoma.

CASCADES, a novel SOX2 super-enhancer-associated long noncoding RNA, regulates cancer stem cell specification and differentiation in glioblastoma

Glioblastoma is the most common primary malignant brain tumor in adults, with a median survival of just over 1 year. The failure of available treatments to achieve remission in patients with glioblastoma (GBM) has been attributed to the presence of cancer stem cells (CSCs), which are thought to play a central role in tumor development and progression and serve as a treatment-resistant cell repository capable of driving tumor recurrence. In fact, the property of "stemness" itself may be responsible for treatment resistance. In this study, we identify a novel long noncoding RNA (lncRNA), cancer stem cell-associated distal enhancer of SOX2 (CASCADES), that functions as an epigenetic regulator in glioma CSCs (GSCs). CASCADES is expressed in isocitrate dehydrogenase (IDH)-wild-type GBM and is significantly enriched in GSCs. Knockdown of CASCADES in GSCs results in differentiation towards a neuronal lineage in a cell- and cancer-specific manner. Bioinformatics analysis reveals that CASCADES functions as a super-enhancer-associated lncRNA epigenetic regulator of SOX2. Our findings identify CASCADES as a critical regulator of stemness in GSCs that represents a novel epigenetic and therapeutic target for disrupting the CSC compartment in glioblastoma.

Targeting CDK4/6 suppresses colorectal cancer by destabilizing YAP1

Colorectal cancer (CRC) is among the most prevalent and deadly cancers worldwide. The Yes-associated protein 1 (YAP1) is frequently dysregulated in cancers, contributing to cancer stemness, chemoresistance, and cancer-related death. However, strategies directly targeting YAP1 have not yet been successful because of the lack of active binding pockets and unregulated toxicity. In this study, our Food and Drug Administration (FDA)-approved drug screening reveals that abemaciclib, a cyclin-dependent kinase 4/6 (CDK4/6) inhibitor, dramatically promotes the proteasome-dependent degradation of YAP1, thereby inhibiting tumor progression in CRC cells and patient-derived xenograft models. We further identify deubiquitinating enzyme 3 (DUB3) as the bona fide deubiquitinase of YAP1 in CRC. Mechanistically, CDK4/6 directly phosphorylates DUB3 at Ser41, activating DUB3 to deubiquitinate and stabilize YAP1. Conversely, loss of Ser41 phosphorylation by CDK4/6 inhibition or Ser41A mutation, promotes YAP1 degradation and suppresses YAP1-driven tumor progression. Histological analysis shows a positive correlation between DUB3 and YAP1 expression in CRC specimens. Collectively, our study uncovers a novel oncogenic role of the CDK4/6-DUB3 pathway, which promotes YAP1 stabilization and tumor-promoting function, highlighting that targeting CDK4/6 offers a potential therapeutic strategy for CRC with aberrantly upregulated DUB3 and YAP1.

The translatome of glioblastoma

Glioblastoma (GB), the most common and aggressive brain tumor, demonstrates intrinsic resistance to current therapies, resulting in poor clinical outcomes. Cancer progression can be partially attributed to the deregulation of protein translation mechanisms that drive cancer cell growth. In this study, we present the translatome landscape of GB as a valuable data resource. Eight patient-derived GB sphere cultures (GSCs) were analyzed using ribosome profiling and messenger RNA (mRNA) sequencing. We investigated inter-cell-line differences through differential expression analysis at both the translatome and transcriptome levels. Translational changes post-radiotherapy were assessed at 30 and 60 min. The translation of non-coding RNAs (ncRNAs) was validated using in-house and public mass spectrometry (MS) data, whereas RNA expression was confirmed by quantitative PCR (qPCR). Our findings demonstrate that ribosome sequencing provides more detailed information than MS or transcriptional analyses. Transcriptional similarities among GSCs correlate with translational similarities, aligning with previously defined subtypes such as proneural and mesenchymal. Additionally, we identified a broad spectrum of open reading frame types in both coding and non-coding mRNA regions, including long non-coding RNAs (lncRNAs) and pseudogenes undergoing active translation. Translation of ncRNAs into peptides was independently confirmed by in-house data and external MS data. We also observed that translational regulation of histones (downregulated) and splicing factors (upregulated) occurs in response to radiotherapy. These data offer new insights into genome-wide protein synthesis, identifying translationally regulated genes and alternative translation initiation sites in GB under normal and radiotherapeutic conditions, providing a rich resource for GB research. Further functional validation of differentially expressed genes after radiotherapy is needed. Understanding translational control in GB can reveal mechanistic insights and identify currently unknown biomarkers, ultimately enhancing the diagnosis and treatment of this aggressive brain cancer.

A novel TAp73-inhibitory compound counteracts stemness features of glioblastoma stem cells

Glioblastoma (GB) is the most common and fatal type of primary malignant brain tumor for which effective therapeutics are still lacking. GB stem cells, with tumor-initiating and self-renewal capacity, are mostly responsible for GB malignancy, representing a crucial target for therapies. The TP73 gene, which is highly expressed in GB, gives rise to the TAp73 isoform, a pleiotropic protein that regulates neural stem cell biology; however, its role in cancer has been highly controversial. We inactivated TP73 in human GB stem cells and revealed that TAp73 is required for their stemness potential, acting as a regulator of the transcriptional stemness signatures, highlighting TAp73 as a possible therapeutic target. As proof of concept, we identified a novel natural compound with TAp73-inhibitory capacity, which was highly effective against GB stem cells. The treatment reduced GB stem cell-invasion capacity and stem features, at least in part by TAp73 repression. Our data are consistent with a novel paradigm in which hijacking of p73-regulated neurodevelopmental programs, including neural stemness, might sustain tumor progression, pointing out TAp73 as a therapeutic strategy for GB.

Cancer stem cells: Masters of all traits

Cancer is a heterogeneous disease, which contributes to its rapid progression and therapeutic failure. Besides interpatient tumor heterogeneity, tumors within a single patient can present with a heterogeneous mix of genetically and phenotypically distinct subclones. These unique subclones can significantly impact the traits of cancer. With the plasticity that intratumoral heterogeneity provides, cancers can easily adapt to changes in their microenvironment and therapeutic exposure. Indeed, tumor cells dynamically shift between a more differentiated, rapidly proliferating state with limited tumorigenic potential and a cancer stem cell (CSC)-like state that resembles undifferentiated cellular precursors and is associated with high tumorigenicity. In this context, CSCs are functionally located at the apex of the tumor hierarchy, contributing to the initiation, maintenance, and progression of tumors, as they also represent the subpopulation of tumor cells most resistant to conventional anti-cancer therapies. Although the CSC model is well established, it is constantly evolving and being reshaped by advancing knowledge on the roles of CSCs in different cancer types. Here, we review the current evidence of how CSCs play a pivotal role in providing the many traits of aggressive tumors while simultaneously evading immunosurveillance and anti-cancer therapy in several cancer types. We discuss the key traits and characteristics of CSCs to provide updated insights into CSC biology and highlight its implications for therapeutic development and improved treatment of aggressive cancers.

Exploiting metabolic vulnerability in glioblastoma using a brain-penetrant drug with a safe profile

Glioblastoma is one of the most treatment-resistant and lethal cancers, with a subset of self-renewing brain tumour stem cells (BTSCs), driving therapy resistance and relapse. Here, we report that mubritinib effectively impairs BTSC stemness and growth. Mechanistically, bioenergetic assays and rescue experiments showed that mubritinib targets complex I of the electron transport chain, thereby impairing BTSC self-renewal and proliferation. Gene expression profiling and Western blot analysis revealed that mubritinib disrupts the AMPK/p27Kip1 pathway, leading to cell-cycle impairment. By employing in vivo pharmacokinetic assays, we established that mubritinib crosses the blood-brain barrier. Using preclinical patient-derived and syngeneic models, we demonstrated that mubritinib delays glioblastoma progression and extends animal survival. Moreover, combining mubritinib with radiotherapy or chemotherapy offers survival advantage to animals. Notably, we showed that mubritinib alleviates hypoxia, thereby enhancing ROS generation, DNA damage, and apoptosis in tumours when combined with radiotherapy. Encouragingly, toxicological and behavioural studies revealed that mubritinib is well tolerated and spares normal cells. Our findings underscore the promising therapeutic potential of mubritinib, warranting its further exploration in clinic for glioblastoma therapy.