Human Tumor Research Articles

Transcriptomic analysis-guided assessment of precision-cut tumor slices (PCTS) as an ex-vivo tool in cancer research

With cancer immunotherapy and precision medicine dynamically evolving, there is greater need for pre-clinical models that can better replicate the intact tumor and its complex tumor microenvironment (TME). Precision-cut tumor slices (PCTS) have recently emerged as an ex vivo human tumor model, offering the opportunity to study individual patient responses to targeted therapies, including immunotherapies. However, little is known about the physiologic status of PCTS and how culture conditions alter gene expression. In this study, we generated PCTS from head and neck cancers (HNC) and mesothelioma tumors (Meso) and undertook transcriptomic analyses to understand the changes that occur in the timeframe between PCTS generation and up to 72 h (hrs) in culture. Our findings showed major changes occurring during the first 24 h culture period of PCTS, involving genes related to wound healing, extracellular matrix, hypoxia, and IFNγ-dependent pathways in both tumor types, as well as tumor-specific changes. Collectively, our data provides an insight into PCTS physiology, which should be taken into consideration when designing PCTS studies, especially in the context of immunology and immunotherapy.

Cryptorchidism and testicular cancer in the dog: unresolved questions and challenges in translating insights from human studies.

Cryptorchidism, the failure of one or both testes to descend into the scrotum, and testicular cancer show a strong correlation in both dogs and humans. Yet, long-standing medical debates persist about whether the location of undescended testes directly causes testicular cancer in humans or if both conditions stem from a common origin. Although testicular cancer is a prevalent disease in dogs, even less is known about its cause and correlation with testicular descent in this species. This review investigates the relation between these two disorders in dogs, drawing insights from human studies, and examines key biomarkers identified thus far. In addition, it explores potential causal links, including the impact of temperature on maturing testicular cells and a potential shared genetic origin. Notably, this literature review reveals significant differences between men and dogs in reproductive development, histological and molecular features of testicular tumors, and the prevalence of specific tumor types, such as Sertoli cell tumors (SCTs) in cryptorchid dogs and germ cell tumors (GCTs) in humans. These disparities caution against using dogs as models for human testicular cancer research and underscore the limitations when drawing comparisons between species. The paper concludes by suggesting specific research initiatives to enhance our understanding of the complex interplay between cryptorchidism and testicular cancer in dogs.

Chondrosarcoma evaluation using hematein-based x-ray staining and high-resolution 3D micro-CT: a feasibility study

BackgroundChondrosarcomas are rare malignant bone tumors diagnosed by analyzing radiological images and histology of tissue biopsies and evaluating features such as matrix calcification, cortical destruction, trabecular penetration, and tumor cell entrapment.MethodsWe retrospectively analyzed 16 cartilaginous tumor tissue samples from three patients (51-, 54-, and 70-year-old) diagnosed with a dedifferentiated chondrosarcoma at the femur, a moderately differentiated chondrosarcoma in the pelvis, and a predominantly moderately differentiated chondrosarcoma at the scapula, respectively. We combined a hematein-based x-ray staining with high-resolution three-dimensional (3D) microscopic x-ray computed tomography (micro-CT) for nondestructive 3D tumor assessment and tumor margin evaluation.ResultsWe detected trabecular entrapment on 3D micro-CT images and followed bone destruction throughout the volume. In addition to staining cell nuclei, hematein-based staining also improved the visualization of the tumor matrix, allowing for the distinction between the tumor and the bone marrow cavity. The hematein-based staining did not interfere with further conventional histology. There was a 5.97 ± 7.17% difference between the relative tumor area measured using micro-CT and histopathology (p = 0.806) (Pearson correlation coefficient r = 0.92, p = 0.009). Signal intensity in the tumor matrix (4.85 ± 2.94) was significantly higher in the stained samples compared to the unstained counterparts (1.92 ± 0.11, p = 0.002).ConclusionsUsing nondestructive 3D micro-CT, the simultaneous visualization of radiological and histopathological features is feasible.Relevance statement3D micro-CT data supports modern radiological and histopathological investigations of human bone tumor specimens. It has the potential for being an integrative part of clinical preoperative diagnostics.Key points• Matrix calcifications are a relevant diagnostic feature of bone tumors.• Micro-CT detects all clinically diagnostic relevant features of x-ray-stained chondrosarcoma.• Micro-CT has the potential to be an integrative part of clinical diagnostics.Graphical

Medicinal attributes of thienopyrimidine scaffolds incorporating the aryl urea motif as potential anticancer candidates via VEGFR inhibition.

Worldwide, cancer is a major public health concern. It is a well-acknowledged life-threatening disease. Despite numerous advances in the understanding of the genetic basis of cancer growth and progression, therapeutic challenges remain high. Human tumors exhibited mutation or overexpression of several tyrosine kinases (TK). The vascular endothelial growth factor receptor (VEGFR) is a TK family member and is well known for tumor growth and progression. Therefore, VEGF/VEGFR pathway inhibition is an appealing approach for cancer drug discovery. This review will discuss the structure-based optimization of thienopyrimidines incorporating the aryl urea moiety to develop scaffolds of potent anticancer activity via VEGFR inhibition published between 2013 and 2023. Increasing knowledge of probable scaffolds that can act as VEGFR inhibitors might spur the hunt for novel anticancer medications that are safer, more effective, or both.

Single-cell mtDNA dynamics in tumors is driven by coregulation of nuclear and mitochondrial genomes.

The extent of cell-to-cell variation in tumor mitochondrial DNA (mtDNA) copy number and genotype, and the phenotypic and evolutionary consequences of such variation, are poorly characterized. Here we use amplification-free single-cell whole-genome sequencing (Direct Library Prep (DLP+)) to simultaneously assay mtDNA copy number and nuclear DNA (nuDNA) in 72,275 single cells derived from immortalized cell lines, patient-derived xenografts and primary human tumors. Cells typically contained thousands of mtDNA copies, but variation in mtDNA copy number was extensive and strongly associated with cell size. Pervasive whole-genome doubling events in nuDNA associated with stoichiometrically balanced adaptations in mtDNA copy number, implying that mtDNA-to-nuDNA ratio, rather than mtDNA copy number itself, mediated downstream phenotypes. Finally, multimodal analysis of DLP+ and single-cell RNA sequencing identified both somatic loss-of-function and germline noncoding variants in mtDNA linked to heteroplasmy-dependent changes in mtDNA copy number and mitochondrial transcription, revealing phenotypic adaptations to disrupted nuclear/mitochondrial balance.

Carboxylesterase Activatable Molecular Probe for Personalized Treatment Guidance by Analyte-Induced Molecular Transformation.

Accurate visualization of tumor microenvironment is of great significance for personalized medicine. Here, we develop a near-infrared (NIR) fluorescence/photoacoustic (FL/PA) dual-mode molecular probe (denoted as NIR-CE) for distinguishing tumors based on carboxylesterase (CE) level by an analyte-induced molecular transformation (AIMT) strategy. The recognition moiety for CE activity is the acetyl unit of NIR-CE, generating the pre-product, NIR-CE-OH, which undergoes spontaneous hydrogen atom exchange between the nitrogen atoms in the indole group and the phenol hydroxyl group, eventually transforming into NIR-CE-H. In cellular experiments and in vivo blind studies, the human hepatoma cells and tumors with high level of CE were successfully distinguished by both NIR FL and PA imaging. Our findings provide a new molecular imaging strategy for personalized treatment guidance.

The glucose transporter GLUT12, a new actor in obesity and cancer.

Obesity constitutes a global health epidemic which worsens the main leading death causes such as type 2 diabetes, cardiovascular diseases, and cancer. Changes in the metabolism in patients with obesity frequently lead to insulin resistance, along with hyperglycemia, dyslipidemia and low-grade inflammation, favoring a more aggressive tumor microenvironment. One of the hallmarks of cancer is the reprogramming of the energy metabolism, in which tumor cells change oxidative phosphorylation to aerobic glycolysis or "Warburg effect". Aerobic glycolysis is faster than oxidative phosphorylation, but less efficient in terms of ATP production. To obtain sufficient ATP, tumor cells increase glucose uptake by the glucose transporters of the GLUT/SLC2 family. The human glucose transporter GLUT12 was isolated from the breast cancer cell line MCF7. It is expressed in adipose tissue, skeletal muscle and small intestine, where insulin promotes its translocation to the plasma membrane. Moreover, GLUT12 over-expression in mice increases the whole-body insulin sensitivity. Thus, GLUT12 has been proposed as a second insulin-responsive glucose transporter. In obesity, GLUT12 is downregulated and does not respond to insulin. In contrast, GLUT12 is overexpressed in human solid tumors such as breast, prostate, gastric, liver and colon. High glucose concentration, insulin, and hypoxia upregulate GLUT12 both in adipocytes and tumor cells. Inhibition of GLUT12 mediated Warburg effect suppresses proliferation, migration, and invasion of cancer cells and xenografted tumors. This review summarizes the up-to-date information about GLUT12 physiological role and its implication in obesity and cancer, opening new perspectives to consider this transporter as a therapeutic target.

Carboxylesterase Activatable Molecular Probe for Personalized Treatment Guidance by Analyte‐Induced Molecular Transformation

Accurate visualization of tumor microenvironment is of great significance for personalized medicine. Here, we develop a near‐infrared (NIR) fluorescence/photoacoustic (FL/PA) dual‐mode molecular probe (denoted as NIR‐CE) for distinguishing tumors based on carboxylesterase (CE) level by an analyte‐induced molecular transformation (AIMT) strategy. The recognition moiety for CE activity is the acetyl unit of NIR‐CE, generating the pre‐product, NIR‐CE‐OH, which undergoes spontaneous hydrogen atom exchange between the nitrogen atoms in the indole group and the phenol hydroxyl group, eventually transforming into NIR‐CE‐H. In cellular experiments and in vivo blind studies, the human hepatoma cells and tumors with high level of CE were successfully distinguished by both NIR FL and PA imaging. Our findings provide a new molecular imaging strategy for personalized treatment guidance.

TOP CAR with TMIGD2 as a safe and effective costimulatory domain in CAR cells treating human solid tumors.

Chimeric antigen receptor (CAR)-T cell therapy shows impressive efficacy treating hematologic malignancies but requires further optimization in solid tumors. Here, we developed a TMIGD2 optimized potent/persistent (TOP) CAR that incorporated the costimulatory domain of TMIGD2, a T and NK cell costimulator, and monoclonal antibodies targeting the IgV domain of B7-H3, an immune checkpoint expressed on solid tumors and tumor vasculature. Comparing second- and third-generation B7-H3 CARs containing TMIGD2, CD28, and/or 4-1BB costimulatory domains revealed superior antitumor responses in B7-H3.TMIGD2 and B7-H3.CD28.4-1BB CAR-T cells in vitro. Comparing these two constructs using in vivo orthotopic human cancer models demonstrated that B7-H3.TMIGD2 CAR-T cells had equivalent or superior antitumor activity, survival, expansion, and persistence. Mechanistically, B7-H3.TMIGD2 CAR-T cells maintained mitochondrial metabolism; produced less cytokines; and established fewer exhausted cells, more central memory cells, and a larger CD8/CD4 T cell ratio. These studies demonstrate that the TOP CAR with TMIGD2 costimulation offered distinct benefits from CD28.41BB costimulation and is effective against solid tumors.

Dimeric Bis-Benzimidazole-Pyrroles DB2Py(n) - AT-Site-Specific Ligands: Synthesis, Physicochemical Analysis, and Biological Activity.

Its broad spectrum of biological activity makes benzimidazole a fundamental pharmacophore in pharmaceutics. The paper describes newly synthesized AT-specific fluorescent bis-benzimidazole molecules DB2Py(n) that contain a pyrrolcarboxamide fragment of the antibiotic drug netropsin. Physico-chemical methods using absorption, fluorescence, and circular dichroism spectra have shown the ability of bis-benzimidazole- pyrroles to form complexes with DNA. The new DB2Py(n) series have turned out to be more toxic to human tumor lines and less vulnerable to non-tumor cell lines. Bis-benzimidazole-pyrroles penetrated the cell nucleus, affected the cell-cycle synthesis (S) phase, and inhibited eukaryotic topoisomerase I in a cellfree model at low concentrations. A real-time tumor cell proliferation test confirmed the molecule's enhanced toxic properties upon dimerization. Preliminary cytotoxicity data for the bis-benzimidazole-pyrroles tested in a cell model with a MDR phenotype showed that monomeric compounds can overcome MDR, while dimerization weakens this ability to its intermediate values as compared to doxorubicin. In this respect, the newly synthesized cytotoxic structures seem promising for further, in-depth study of their properties and action mechanism in relation to human tumor cells, as well as for designing new AT-specific ligands.

Cytotoxic prenylated phenols of false indigo-bush (Amorpha fruticosa L.)

This study employed the MTT assay to assess the cytotoxicity of one flavan and two stilbene derivatives isolated from the false indigo-bush (Amorpha fruticosa L.) fruits: 5,7-dihydroxy-8-geranylflavanone (1), 2-carboxy-3,5-dihydroxy-4-geranylbibenzyl (2), and 2-carboxy-3-hydroxy-4-prenyl-5-methoxybibenzyl (3). The examined compounds reduced the survival of human cervical and colon tumour cells (HeLa, HT-29, HCT-116, and LS174) with IC50 values ranging from 10.55 to 147.09 μg/mL, except for 1, which did not affect LS174 cells within the tested concentrations. The highest activity was observed for 1 against HeLa cells, and 1 also exhibited the weakest effect against normal foetal lung fibroblasts (IC50 = 166.11 μg/mL), demonstrating good potency and selectivity. Stilbenes 2 and 3 proved efficacious, but lacked selectivity compared to 1. Our findings revealed the cytotoxicity of false indigo-bush constituents, justifying further mechanistic and in vivo investigations, particularly on 5,7-dihydroxy-8-geranylflavanone, which displayed considerable in vitro anticancer capacity and a potentially favourable safety profile.

Application of Machine Learning Algorithms for Prediction of Tumor T-Cell Immunogens

The identification and characterization of immunogenic tumor antigens are essential for cancer vaccine development. In light of the impracticality of isolating and evaluating each putative antigen individually, in silico prediction algorithms, particularly those utilizing machine learning (ML) approaches, play a pivotal role. These algorithms significantly reduce the experimental workload necessary for discovering vaccine candidates. In this study, we employed six supervised ML methods on a dataset comprising 212 experimentally validated human tumor peptide antigens and an equal number of non-antigenic human peptides to develop models for immunogenicity prediction. These methods encompassed k-nearest neighbor (kNN), linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), support vector machine (SVM), random forest (RF), and extreme gradient boosting (XGBoost). The models underwent validation through internal cross-validation within 10 groups from the training set and were further assessed using an external test set. Remarkably, the kNN model demonstrated superior performance, recognizing 90% of the known immunogens in the test set. The RF model excelled in the identification of non-immunogens, accurately classifying 93% of them in the test set. The three top-performing ML models according to multiple evaluation metrics (SVM, RF, and XGBoost) are to be subsequently integrated into the new version of the VaxiJen server, facilitating tumor antigen prediction through a majority voting mechanism.

B7-H3-Targeting Chimeric Antigen Receptors Epstein Barr Virus Specific T Cells Provides a Tumor Agnostic Off-The-Shelf Therapy Against B7-H3 Positive Solid Tumors.

Encouraged by our observations of pronounced B7-H3 protein over-expression in many human solid tumors compared to healthy tissues, we focused on targeting B7-H3 with CAR T cells. We utilized a nanobody as the t B7-H3 targeting domain in our CAR construct to circumvent the stability issues associated with scFv-based domains. In efforts to expand patient access to CAR T cell therapy, we engineered our nanobody-based CAR into human Epstein-Barr Virus Specific T Cells (EBVSTs), offering a readily available off-the-shelf treatment. B7H3.CAR-armored EBVSTs demonstrated potent in vitro and in vivo activities against multiple B7-H3-positive human tumor cell lines and patient-derived xenograft models. Murine T cells expressing a murine equivalent of our B7H3.CAR exhibited no life-threatening toxicities in immunocompetent mice bearing syngeneic tumors. Further in vitro evaluation revealed that while human T, B and NK cells were unaffected by B7H3.CAR EBVSTs, monocytes were targeted due to upregulation of B7-H3. Such targeting of myeloid cells, which are key mediators of cytokine release syndrome (CRS), contributed to a low incidence of CRS in humanized mice after B7H3.CAR EBVST treatment. Notably, we showed that B7H3.CAR EBVSTs can target B7-H3 expressing myeloid-derived suppressor cells (MDSCs), thereby mitigating MDSC-driven immune suppression. In summary, our data demonstrate that our nanobody-based B7H3.CAR EBVSTs are effective as an off-the-shelf therapy for B7-H3 positive solid tumors. These cells also offer an avenue to modulate the immunosuppressive tumor microenvironment, highlighting their promising clinical potential in targeting solid tumors.

A Neural Tract-Inspired Conduit for Facile, On-Demand Biopsy of Glioblastoma

Abstract Background A major hurdle to effectively treating glioblastoma (GBM) patients is the lack of longitudinal information about tumor progression, evolution, and treatment response. Methods In this study, we report the use of a neural tract-inspired conduit containing aligned polymeric nanofibers (i.e., an aligned nanofiber device) to enable on-demand access to GBM tumors in two rodent models. Depending on the experiment, a humanized U87MG xenograft tumor and/or F98-GFP+ syngeneic rat tumor models were chosen to test the safety and functionality of the device in providing continuous sampling access to the tumor and its microenvironment. Results The aligned nanofiber device was safe and provided a high quantity of quality genomic materials suitable for omics analyses and yielded a sufficient number of live cells for in vitro expansion and screening. Transcriptomic and genomic analyses demonstrated continuity between material extracted from the device and that of the primary, intracortical tumor (in the in vivo model). Conclusions The results establish the potential of this neural tract-inspired, aligned nanofiber device as an on-demand, safe, and minimally invasive access point which enables rapid, high-throughput, longitudinal assessment of tumor and its microenvironment, leading to more informed clinical treatment strategies.

Plasminogen activator inhibitor-1 promotes immune evasion in tumors by facilitating the expression of programmed cell death-ligand 1

BackgroundIncreased levels of plasminogen activator inhibitor-1 (PAI-1) in tumors have been found to correlate with poor clinical outcomes in patients with cancer. Although abundant data support the involvement of PAI-1 in cancer progression, whether PAI-1 contributes to tumor immune surveillance remains unclear. The purposes of this study are to determine whether PAI-1 regulates the expression of immune checkpoint molecules to suppresses the immune response to cancer and demonstrate the potential of PAI-1 inhibition for cancer therapy.MethodsThe effects of PAI-1 on the expression of the immune checkpoint molecule programmed cell death ligand 1 (PD-L1) were investigated in several human and murine tumor cell lines. In addition, we generated tumor-bearing mice and evaluated the effects of a PAI-1 inhibitor on tumor progression or on the tumor infiltration of cells involved in tumor immunity either alone or in combination with immune checkpoint inhibitors.ResultsPAI-1 induces PD-L1 expression through the JAK/STAT signaling pathway in several types of tumor cells and surrounding cells. Blockade of PAI-1 impedes PD-L1 induction in tumor cells, significantly reducing the abundance of immunosuppressive cells at the tumor site and increasing cytotoxic T-cell infiltration, ultimately leading to tumor regression. The anti-tumor effect elicited by the PAI-1 inhibitor is abolished in immunodeficient mice, suggesting that PAI-1 blockade induces tumor regression by stimulating the immune system. Moreover, combining a PAI-1 inhibitor with an immune checkpoint inhibitor significantly increases tumor regression.ConclusionsPAI-1 protects tumors from immune surveillance by increasing PD-L1 expression; hence, therapeutic PAI-1 blockade may prove valuable in treating malignant tumors.

Left ventricular global longitudinal strain is worse in BRCA mutation positive breast cancer patients prior to cancer treatment and premature menopause.

Breast cancer patients with mutations in human tumor suppressor genes BRCA1 and BRCA2 are at higher risk of cardiovascular disease (CVD) than the general population, as they are frequently exposed to cardiotoxic chemotherapy, anti-estrogen therapy, radiation, and/or oophorectomy for cancer-related treatment and prophylaxis. Animal and cell culture models suggest that BRCA mutations may play an independent role in heart failure. We sought to evaluate cardiac structure and function in female BRCA1 and BRCA2 mutation carriers with breast cancer compared to BRCA wildtype women with breast cancer. We performed a 1:2 age- and hypertension-matched retrospective cohort study comparing BRCA1 and BRCA2 mutation carriers (n = 38) versus BRCA wildtype controls (n = 76) with a new diagnosis of breast cancer. Echocardiographic data were obtained within 6months of breast cancer diagnosis and prior to chemotherapy, anti-estrogen therapy, radiation, or oophorectomy. Left ventricular global longitudinal strain (LV-GLS), a highly sensitive marker of LV function, was measured using QLab 15 (Philips Healthcare). In the total cohort of 114 patients with a new diagnosis of breast cancer, the median age was 45 ± 11years and the prevalence of hypertension was 8%. There were no differences in traditional cardiovascular disease risk factors between cases and controls. BRCA carriers had lower LV-GLS (-18.1% ± 4.7% vs. -20.1% ± 3.8%, p = 0.02) and greater right atrial area (12.9cm2 ± 2.7cm2 vs. 11.8cm2 ± 2.0cm2, p = 0.04) compared to controls; however, both LV-GLS and right atrial area were within the normal range. Compared to controls, BRCA carriers had a trend toward worse LV posterior wall thickness (0.89cm ± 0.15cm vs. 0.83cm ± 0.16cm, p = 0.06) although not statistically significant. In women with newly diagnosed breast cancer and prior to treatment, LV-GLS was worse in BRCA1 and BRCA2 mutation carriers compared to those with BRCA wildtype. These findings suggest that BRCA mutations may be associated with subtle changes in cardiac function. Whether differences in GLS translate to increased cardiovascular risk in women with BRCA mutations needs to be further characterized.

HER2 mutation as an emerging target in advanced breast cancer.

HER2 activating mutations have emerged as oncogenic drivers and therapeutic targets in a variety of human tumors. In breast cancer, these deregulations occur at low frequency, and are mostly detected in HER2-nonamplified, metastatic disease. Preclinical evidence has clarified the role of hotspot mutations in HER2 constitutive activation, defining them as an alternative mechanism to HER2 gene amplification. Furthermore, recent clinical studies have indicated the emergence of newly acquired HER2 deregulations in significant proportions of breast cancer patients who experience disease progression following both endocrine and HER2-targeted therapies. As the involvement of HER2 mutation in therapy resistance may profoundly impact patient outcomes on successive therapies, several clinical trials are currently investigating the efficacy of various HER2-targeted drugs in HER2-mutant breast cancer. In this review, we firstly summarize the structural organization of the HER2 oncogene and its historical impact on breast cancer prognosis and therapeutic advancement. Then, we provide an overview of the frequencies and functional relevance of clinically recurrent HER2 mutations in breast cancer with a special focus on their role in therapeutic resistance. Finally, we provide a collection of the clinical trials that are currently exploring novel therapeutic approaches for this patient subset and discuss the related perspectives and challenges.

Catheter-Directed Ionic Liquid Embolic Agent for Rapid Portal Vein Embolization, Segmentectomy, and Bile Duct Ablation.

Embolic materials currently in use for portal vein embolization (PVE) do not treat the tumor, which poses a risk for tumor progression during the interval between PVE and surgical resection. Here, is developed an ionic-liquid-based embolic material (LEAD) for portal vein embolization, liver ablation, and drug delivery. LEAD is optimized and characterized for diffusivity, X-ray visibility, and cytotoxicity. In the porcine renal embolization model, LEAD delivered from the main renal artery reached vasculature down to 10 microns with uniform tissue ablation and delivery of small and large therapeutics. In non-survival and survival porcine experiments, successful PVE is achieved in minutes, leading to the expected chemical segmentectomy, and delivery of a large protein drug (i.e., Nivolumab) with LEAD. In cholangiocarcinoma mouse tumor models and in ex vivo human tumors, LEAD consistently achieved an effective ablation and wide drug distribution. Furthermore, various strains of drug-resistant patient-derived bacteria showed significant susceptibility to LEAD, suggesting that LEAD may also prevent infectious complications resulting from tissue ablation. With its capabilities to embolize, ablate, and deliver therapeutics, ease of use, and a high safety profile demonstrated in animal studies, LEAD offers a potential alternative to tumor ablation with or without PVE for FLR growth.

Temporal and regional expression changes and co-staining patterns of metabolic and stemness-related markers during glioblastoma progression.

Glioblastomas (GBMs) are characterized by high heterogeneity, involving diverse cell types, including those with stem-like features contributing to GBM's malignancy. Moreover, metabolic alterations promote growth and therapeutic resistance of GBM. Depending on the metabolic state, antimetabolic treatments could be an effective strategy. Against this background, we investigated temporal and regional expression changes and co-staining patterns of selected metabolic markers [pyruvate kinase muscle isozyme 1/2 (PKM1/2), glucose transporter 1 (GLUT1), monocarboxylate transporter 1/4 (MCT1/4)] in a rodent model and patient-derived samples of GBM. To understand the cellular sources of marker expression, we also examined the connection of metabolic markers to markers related to stemness [Nestin, Krüppel-like factor 4 (KLF4)] in a regional and temporal context. Rat tumour biopsies revealed a temporally increasing expression of GLUT1, higher expression of MCT1/4, Nestin and KLF4, and lower expression of PKM1 compared to the contralateral hemisphere. Patient-derived tumours showed a higher expression of PKM2 and Nestin in the tumour centre vs. edge. Whereas rare co-staining of GLUT1/Nestin was found in tumour biopsies, PKM1/2 and MCT1/4 showed a more distinct co-staining with Nestin in rats and humans. KLF4 was mainly co-stained with GLUT1, MCT1 and PKM1/2 in rat and human tumours. All metabolic markers yielded individual co-staining patterns among themselves. Co-staining mainly occurred later in tumour progression and was more pronounced in tumour centres. Also, positive correlations were found amongst markers that showed co-staining. Our results highlight a link between metabolic alterations and stemness in GBM progression, with complex distinctions depending on studied markers, time points and regions.

CTGF expression in human pituitary tumors and its association with their aggressiveness: preliminary data from an ongoing study

CTGF expression in human pituitary tumors and its association with their aggressiveness: preliminary data from an ongoing study