Alanine–Glyoxylate Aminotransferase Sustains Cancer Stemness Properties through the Upregulation of SOX2 and OCT4 in Hepatocellular Carcinoma Cells

Cancer stem cells amino acid metabolism: Roles, mechanisms, and intervention strategies

Cancer stem cells (CSCs) are recognized as key drivers of tumor recurrence and therapy resistance due to their capacity for self-renewal and differentiation. Amino acid metabolic reprogramming, a hallmark of cancer, underpins CSC biology. Methionine, tryptophan, and glutamine support CSC survival and the maintenance of stemness, while proline plays a role in CSC differentiation and susceptibility to cell death. Consequently, the impact of amino acid metabolism on CSCs is multifaceted and complex. This review first outlines the intrinsic amino acid metabolic features of CSCs. It then provides a comprehensive analysis of the distinct roles of various amino acids in regulating CSC biology. Additionally, strategies targeting amino acid metabolism to eliminate CSCs in clinical therapies are discussed, offering new perspectives for the development of innovative tumor-targeting approaches.

Polystyrene microplastics attenuated the impact of perfluorobutanoic acid on Chlorella sorokiniana: Hetero-aggregation, bioavailability, physiology, and transcriptomics

Microplastics (MPs) and perfluorobutanoic acid (PFBA), emerging contaminants, are ubiquitous in the environment and toxic to organisms. The interaction of MPs with other contaminants can affect their toxicity. However, the impact of MPs on PFBA toxicity remains unknown. This research investigated the individual and combined impacts of polystyrene microplastics (PS) and PFBA to Chlorella sorokiniana based on cellular responses and transcriptome analyses. Results showed that both PS and PFBA induced excessive ROS generation, causing cell membrane damage and photosynthesis inhibition, ultimately inhibiting Chlorella sorokiniana growth. The highest inhibition was observed for small particle size PS, with a maximum inhibition rate of 15.98 ± 1.24 % (3PS group). Notably, the combined toxicity of PFBA and PS exhibited antagonism, which was attributed to PFBA adsorption and PS hetero-aggregation via massive EPS secretion, resulting in decreased PS and PFBA bioavailability. Transcriptomic analysis elucidated that EPS secretion was promoted owing to the up-regulation of carbohydrate, amino acid, and energy metabolism (carbon fixation, oxidative phosphorylation, and TCA cycle). Enhanced EPS secretion, ABC transport, and antioxidant response alleviated PS and PFBA toxicity. Our findings offer valuable data for the joint ecotoxicity of PFASs and MPs, contributing to environmental risk assessment of co-pollution.

FVTF inhibits hepatocellular carcinoma stem properties via targeting DNMT1/miR-34a-5p/FoxM1 axis

BACKGROUND

Fructus Viticis Total Flavonoids (FVTF) is a novel candidate preparation that possesses anticancer activity. However, the role and mechanism of FVTF-inhibiting human hepatocellular carcinoma (HCC) cell stem properties is unclear.

METHODS

Liquid chromatography (LC) in conjugation with mass spectrometer (MS) was used to identify the compounds of FVTF. Tumorsphere and soft agar colony formation ability, cancer stem marker expression levels, CD133+ cell percentage, and a xenograft model were utilized to investigate the impact of FVTF on HCC cells stemness. PCR array and qRT-PCR were conducted to identify differentially expressed cancer stem-related genes and miRNAs between FVTF-treated and untreated HCC cells, respectively. Pyrosequencing was conducted to assess the DNA methylation level of the miR-34a-5p promoter. A luciferase reporter assay was performed to verify whether FoxM1 serves as a direct target of miR-34a-5p. Additionally, immunohistochemistry of an HCC tissue microarray was carried out to assess the expression levels of DNMT1, FoxM1, and miR-34a-5p.

RESULTS

A total of 26 compounds, including 10 flavones, in FVTF were identified. FVTF significantly reduced the ability of tumorsphere and soft agar colony formation, the levels of CD44 protein and BMI1, OCT4 and SOX2 mRNAs in HCC cells, and in vivo tumor initiation ability of HCC cells. Mechanistically, FVTF inhibited HCC cell stem properties via targeting DNMT1/miR-34a-5p/FoxM1 axis. Clinically, DNMT1 expression was inversely correlated with miR-34a-5p expression, whereas a positive correlation was noted between DNMT1 and FoxM1 expression levels, and high DNMT1 levels, low miR-34a-5p levels, and high FoxM1 levels were associated with cancer recurrence. Furthermore, a combination of DNMT1, miR-34a-5p and FoxM1 served as an independent prognostic indicator influencing both DFS and OS in patients with HCC.

CONCLUSIONS

FVTF inhibits HCC cell stem properties by targeting DNMT1/miR-34a-5p/FoxM1 axis, which is associated with HCC recurrence and prognosis, and FVTF is a prospective treatment drug for human HCC.

The role of liver cancer stem cells in hepatocellular carcinoma metastasis

Metastasis accounts for the vast majority of cancer deaths; however, this complex process has yet to be fully explained. To form metastases, cancer cells must undergo a series of steps, known as the "Metastatic cascade", each of which requires a specific functional transformation. Cancer stem cells (CSCs) play a vital role in tumor metastasis, but their dynamic behavior and regulatory mechanisms have not been fully elucidated. Based on the "Metastatic cascade" theory, this review summarizes the effect of liver CSCs on the metastatic biological programs that underlie the dissemination and metastatic growth of cancer cells. Liver CSCs have the capacity to initiate distant organ metastasis via EMT, and the microenvironment transformation that supports the ability of these cells to disseminate, evade immune surveillance, dormancy, and regenerate metastasis. Understanding the heterogeneity and traits of liver CSCs in these processes is critical for developing strategies to prevent and treat metastasis of advanced hepatocellular carcinoma (HCC).

Effects of deep, air and vacuum frying on oyster quality and protein-mediated mechanism analysis via TMT quantitative proteomics

Fried oyster is a popular aquatic food product in East Asia, but nutrient loss during thermal processing become a significant concern. The goal of this research was to examine the impact of distinct frying techniques, including deep frying (DF), air frying (AF), and vacuum frying (VF), on the nutritional, textural and flavor characteristics of oysters. The VF method demonstrated superior retention of beneficial properties and flavor, and reduced protein and lipid oxidation compared to the DF and AF methods. Furthermore, proteomic analysis of oysters was attempted to explain the molecular mechanisms governing the influence of key differential proteins. 20 major differential proteins, including actin-2 protein, tryptophan 2,3-dioxygenase and 1-alph, involved in oyster protein oxidation were identified, annotated and analyzed to elucidate their influence mechanisms. This research provides a deeper understanding of intricate interactions between frying techniques and oyster biochemistry, which offers valuable implications for enhancing food quality in seafood industry.

Differential gene expression analysis supports dysregulation of mitochondrial activity as a new perspective for glioblastoma's aggressiveness

Brain cancer is considered one of the most aggressive and lethal types of cancer, including primary tumors, being subdivided into milder forms such as low-grade gliomas and glioblastoma, considered the most aggressive form with higher invasion. Among the hallmarks of glioblastoma, the deregulation of mitochondrial metabolism has not yet been fully elucidated. Therefore, the search for mitochondrial biomarkers that can be used as indicators of the progression of this type of cancer is necessary. The aim of this study was to investigate the difference in gene expression between astrocytoma-type gliomas and glioblastomas, and how genes involved in mitochondrial metabolism can influence the proliferative cascade and be associated with tumor invasion. From the differential analysis of glioblastoma expression when compared to the milder form, 11 differentially expressed genes (DEGs) were found in our study, six of which were upregulated (ATP5MGL, C15orf48, MCUB, TERT, AGXT and CYP27B1) and four downregulated (SLC2A4, GK2, SLC25A48, ETNPPL and HMGCS2). To validate the findings, we used other independent bulk RNA-seq datasets and evaluated the number of normalized counts of the DEGs founded. Among these genes, we highlight that none of them had been reported in glioblastoma until this research, and we suggest these genes as possible biomarkers to be further explored, since they are associated with essential pathways for the tumor, such as glucose metabolization, gluconeogenesis, calcium and vitamin D metabolism, tumor progression and activation of the invasion cascade.

The Z isomer of pyridoxilidenerhodanine 5'-phosphate is an efficient inhibitor of human pyridoxine 5'-phosphate oxidase, a crucial enzyme in vitamin B6 salvage pathway and a potential chemotherapeutic target

Pyridoxal 5'-phosphate (PLP), the catalytically active form of vitamin B6, acts as a cofactor in many metabolic processes. In humans, PLP is produced in the reactions catalysed by pyridox(am)ine 5'-phosphate oxidase (PNPO) and pyridoxal kinase (PDXK). Both PNPO and PDXK are involved in cancer progression of many tumours. The silencing of PNPO and PDXK encoding genes determines a strong reduction in tumour size and neoplastic cell invasiveness in models of acute myeloid leukaemia (in the case of PDXK) and ovarian and breast cancer (in the case of PNPO). In the present work, we demonstrate that pyridoxilidenerhodanine 5'-phosphate (PLP-R), a PLP analogue that has been tested by other authors on malignant cell lines reporting a reduction in proliferation, inhibits PNPO in vitro following a mixed competitive and allosteric mechanism. We also show that the unphosphorylated precursor of this inhibitor (PL-R), which has more favourable pharmacokinetic properties according to our predictions, is phosphorylated by PDXK and therefore transformed into PLP-R. On this ground, we propose the prototype of a novel prodrug-drug system as a useful starting point for the development of new, potential, antineoplastic agents.

TESC associated with poor prognosis enhances cancer stemness and migratory properties in liver cancer

Liver cancer stem cells (LCSCs) are responsible for recurrence, metastasis, and drug resistance in liver cancer. However, the genes responsible for inducing LCSCs have not been fully identified. Based on our previous study, we found that tescalcin (TESC), a calcium-binding EF hand protein that plays a crucial role in chromatin remodeling, transcriptional regulation, and epigenetic modifications, was up-regulated in LCSCs of spheroid cultures. By searching the Cancer Genome Atlas, International Cancer Genome Consortium, Human Protein Atlas, and Kaplan-Meier Plotter databases, we found that TESC expression was significantly elevated in liver cancer compared with that in normal liver tissue and was predictive of a decreased overall survival rate. Multivariate Cox analysis revealed TESC to be an independent prognostic factor for survival. High TESC expression was positively associated with cancer stem cell pathways, cancer stem cell surface markers, stemness transcription factors, epithelial-mesenchymal transition (EMT) factors, immune checkpoint proteins, and various cancer-related biological processes in liver cancer. Furthermore, TESC was implicated as promoting cancer stem cell properties through its influence on EMT. We demonstrated that TESC is a novel stemness-related gene that can serve as an independent prognostic factor for liver cancer.

Exploring the Mechanism of H2S Synthesis in Male Bactrian Camel Poll Glands Based on Data Independent Acquisition Proteomics and Non-Targeted Metabolomics

During estrus, the poll glands of male Bactrian Camels (Camelus Bactrianus) become slightly raised, exuding a large amount of pale yellow watery secretion with a characteristic odor that may contain hydrogen sulfide (H2S). However, whether H2S can be synthesized in the poll glands of male Bactrian Camels and its role in inducing camel estrus remains unclear. This study aimed to identify differentially expressed proteins (DEPs) and signaling pathways in the poll gland tissues of male Bactrian Camels using data independent acquisition (DIA) proteomics. Additionally, gas chromatography-mass spectrometry (GC-MS) was performed to identify differentially expressed metabolites (DEMs) in the neck hair containing secretions during estrus in male Bactrian Camels, to explore the specific expression patterns and mechanisms in the poll glands of camels during estrus. The results showed that cystathionine-γ-lyase (CTH) and cystathionine-β-synthase (CBS), which are closely related to H2S synthesis in camel poll glands during estrus, were mainly enriched in glycine, serine, and threonine metabolism, amino acid biosynthesis, and metabolic pathways. In addition, both enzymes were widely distributed and highly expressed in the acinar cells of poll gland tissues in camels during estrus. Meanwhile, the neck hair secretion contains high levels of amino acids, especially glycine, serine, threonine, and cystathionine, which are precursors for H2S biosynthesis. These results demonstrate that the poll glands of male Bactrian Camels can synthesize and secrete H2S during estrus. This study provides a basis for exploring the function and mechanism of H2S in the estrus of Bactrian Camels.

Cancer stem cells: advances in knowledge and implications for cancer therapy

Cancer stem cells (CSCs), a small subset of cells in tumors that are characterized by self-renewal and continuous proliferation, lead to tumorigenesis, metastasis, and maintain tumor heterogeneity. Cancer continues to be a significant global disease burden. In the past, surgery, radiotherapy, and chemotherapy were the main cancer treatments. The technology of cancer treatments continues to develop and advance, and the emergence of targeted therapy, and immunotherapy provides more options for patients to a certain extent. However, the limitations of efficacy and treatment resistance are still inevitable. Our review begins with a brief introduction of the historical discoveries, original hypotheses, and pathways that regulate CSCs, such as WNT/β-Catenin, hedgehog, Notch, NF-κB, JAK/STAT, TGF-β, PI3K/AKT, PPAR pathway, and their crosstalk. We focus on the role of CSCs in various therapeutic outcomes and resistance, including how the treatments affect the content of CSCs and the alteration of related molecules, CSCs-mediated therapeutic resistance, and the clinical value of targeting CSCs in patients with refractory, progressed or advanced tumors. In summary, CSCs affect therapeutic efficacy, and the treatment method of targeting CSCs is still difficult to determine. Clarifying regulatory mechanisms and targeting biomarkers of CSCs is currently the mainstream idea.