PKM2 promotes tumor angiogenesis by regulating HIF-1α through NF-κB activation

HIF-1α regulates the cell viability in radioiodine-resistant papillary thyroid carcinoma cells induced by hypoxia through PKM2/NF-κB signaling pathway

The curative treatment options for papillary thyroid cancer (PTC) encompass surgical intervention, radioactive iodine administration, and chemotherapy. However, the challenges of radioiodine (RAI) resistance, metastasis, and chemotherapy resistance remain inadequately addressed. The objective of this study was to investigate the protective role of hypoxia-inducible factor-1α (HIF-1α) in 131 I-resistant cells and a xenograft model under hypoxic conditions, as well as to explore potential mechanisms. The effects of HIF-1α on 131 I-resistant BCPAP and TPC-1 cells, as well as the xenograft model, were assessed in this study. Cell viability, migration, invasion, and apoptosis rates were measured using Cell Counting Kit-8, wound-healing, Transwell, and flow cytometry assays. Additionally, the expressions of Ki67, matrix metalloproteinase-9 (MMP-9), and pyruvate kinase M2 (PKM2) were examined using immunofluorescence or immunohistochemistry assays. Sodium iodide symporter and PKM2/NF-κBp65 relative protein levels were detected by western blot analysis. The findings of our study indicate that siHIF-1α effectively inhibits cell proliferation, cell migration, and invasion in 131 I-resistant cells under hypoxic conditions. Additionally, the treatment of siHIF-1α leads to alterations in the relative protein levels of Ki67, MMP-9, PKM2, and PKM2/NF-κBp65, both in vivo and in vitro. Notably, the effects of siHIF-1α are modified when DASA-58, an activator of PKM2, is administered. These results collectively demonstrate that siHIF-1α reduces cell viability in PTC cells and rat models, while also mediating the nuclear factor-κB (NF-κB)/PKM2 signaling pathway. Our findings provide a new rationale for further academic and clinical research on RAI-resistant PTC.

New sights of immunometabolism and agent progress in colitis associated colorectal cancer

Colitis associated colorectal cancer is a disease with a high incidence and complex course that develops from chronic inflammation and deteriorates after various immune responses and inflammation-induced attacks. Colitis associated colorectal cancer has the characteristics of both immune diseases and cancer, and the similarity of treatment models contributes to the similar treatment dilemma. Immunometabolism contributes to the basis of life and is the core of many immune diseases. Manipulating metabolic signal transduction can be an effective way to control the immune process, which is expected to become a new target for colitis associated colorectal cancer therapy. Immune cells participate in the whole process of colitis associated colorectal cancer development by transforming their functional condition via changing their metabolic ways, such as glucose, lipid, and amino acid metabolism. The same immune and metabolic processes may play different roles in inflammation, dysplasia, and carcinoma, so anti-inflammation agents, immunomodulators, and agents targeting special metabolism should be used in combination to prevent and inhibit the development of colitis associated colorectal cancer.

Targeting PKM2 improves the gemcitabine sensitivity of intrahepatic cholangiocarcinoma cells via inhibiting β-catenin signaling pathway

Gemcitabine is considered the standard first-line chemotherapeutic agent for patients with intrahepatic cholangiocarcinoma (ICC). However, its therapeutic efficacy is hampered by the development of chemoresistance. Pyruvate kinase M2 (PKM2), a crucial mediator of the final step in glycolysis, has been implicated in the origination and advancement of diverse malignancies. Its expression is increased in many tumor types and this may correlate with increased drug sensitivity. However, the specific effect of PKM2 on the gemcitabine sensitivity in ICC remains to be elucidated. In this research, we aimed to elucidate the role and functional significance of PKM2 in ICC, as well as the heightened susceptibility of ICC cells to gemcitabine by targeting PKM2 and the underlying molecular mechanisms. Immunohistochemical and immunofluorescence analyses revealed elevated expression of PKM2 in both tumor cells and macrophages in human ICC tissues. Reducing PKM2 levels significantly restrained the proliferation of tumor cells, impeded cell cycle advance, induced programmed cell death, and suppressed metastasis. In addition, knockdown or pharmacological inhibition of PKM2 could enhance the response of ICC cells to gemcitabine in vitro. Interestingly, conditioned medium co-culture system suggested that conditioned medium from M2 macrophages increased gemcitabine sensitivity of ICC cells. However, silencing PKM2 or pharmacological inhibition of PKM2 in M2 macrophages did not ameliorate the gemcitabine resistance mediated by M2 macrophages derived conditioned medium. Mechanistically, downregulation of PKM2 repressed the expression of β-catenin and its downstream transcriptional targets, thereby hindering the propagation of β-catenin signaling cascade. Finally, the results of the subcutaneous xenograft experiment in nude mice provided compelling evidence of a synergistic interaction between PKM2-IN-1 and gemcitabine in vivo. In summary, we reported that PKM2 may function as an advantageous target for increasing the sensitivity of ICC to gemcitabine treatment. Targeting PKM2 improves the gemcitabine sensitivity of ICC cells via inhibiting β-catenin signaling pathway.

The Diagnostic and Prognostic Value of the Combination of Tumor M2-Pyruvate Kinase, Carcinoembryonic Antigen, and Cytokeratin 19 Fragment in Non-Small Cell Lung Cancer

Objective: Finding biomarkers related to non-small cell lung cancer (NSCLC) is helpful for the diagnosis and precise treatment of lung cancer. The relationship between serum tumor M2-pyruvate kinase (TuM2-PK), carcinoembryonic antigen (CEA), and cytokeratin 19 fragment (CYFRA21-1) and NSCLC was analyzed. Methods: The serum levels of TuM2-PK, CEA, and CYFRA21-1 in 184 patients with the NSCLC group, 60 patients with the benign lung disease (BLD) group, and 90 healthy controls (HC) group were detected. The levels of TuM2-PK were measured by using an enzyme-linked immunosorbent assay. The detection methods of CEA and CYFRA21-1 were electrochemiluminescence. The receiver operating characteristic (ROC) curve was drawn to evaluate the diagnostic value of TuM2-PK, CEA, and CYFRA21-1 on NSCLC. The Kaplan-Meier survival curve was drawn to evaluate the survival status in NSCLC patients with different serum levels of TuM2-PK, CEA, and CYFRA21-1. Results: Serum levels of TuM2-PK, CEA, and CYFRA21-1 in the NSCLC group were significantly higher than those in the BLD group and the HC group (P < .01). Serum levels of TuM2-PK, CEA, and CYFRA21-1 in NSCLC patients were associated with the tumor lymph node metastasis stage (P < .05), lymph node metastasis (P < .05), and distant metastasis (P < .05). The ROC curve showed that the area under the curve of serum levels of TuM2-PK, CEA, and CYFRA21-1 was 0.814, 0.638, and 0.719, respectively, and that the combination of the above 3 was 0.918. The Kaplan-Meier survival curve showed that the 1-, 3- and 5-year survival rate in NSCLC patients with positive TuM2-PK, CEA, and CYFRA21-1 was significantly lower than that in NSCLC patients with negative TuM2-PK, CEA, and CYFRA21-1, respectively (P < .05). Conclusions: Serum TuM2-PK, CEA, and CYFRA21-1 levels have high clinical values in the diagnosis of NSCLC, and can effectively judge the prognosis of patients.

RFX6 facilitates aerobic glycolysis-mediated growth and metastasis of hepatocellular carcinoma through targeting PGAM1

BACKGROUND

Hepatocellular carcinoma (HCC) cells undergo reprogramming of glucose metabolism to support uncontrolled proliferation, of which the intrinsic mechanism still merits further investigation. Although regulatory factor X6 (RFX6) is aberrantly expressed in different cancers, its precise role in cancer development remains ambiguous.

METHODS

Microarrays of HCC tissues were employed to investigate the expression of RFX6 in tumour and adjacent non-neoplastic tissues. Functional assays were employed to explore the role of RFX6 in HCC development. Chromatin immunoprecipitation, untargeted metabolome profiling and sequencing were performed to identify potential downstream genes and pathways regulated by RFX6. Metabolic assays were employed to investigate the effect of RFX6 on glycolysis in HCC cells. Bioinformatics databases were used to validate the above findings.

RESULTS

HCC tissues exhibited elevated expression of RFX6. High RFX6 expression represented as an independent hazard factor correlated to poor prognosis in patients with HCC. RFX6 deficiency inhibited HCC development in vitro and in vivo, while its overexpression exerted opposite functions. Mechanistically, RFX6 bound to the promoter area of phosphoglycerate mutase 1 (PGAM1) and upregulated its expression. The increased PGAM1 protein levels enhanced glycolysis and further promoted the development of HCC.

CONCLUSIONS

RFX6 acted as a novel driver for HCC development by promoting aerobic glycolysis, disclosing the potential of the RFX6-PGAM1 axis for therapeutic targeting.

The interaction between apigenin and PKM2 restrains progression of colorectal cancer

Apigenin, a flavonoid that widely existed in vegetables and fruits, possesses anticarcinogenic, low toxicity, and no mutagenic properties, suggesting that apigenin is a potential therapeutic agent for tumors. However, the underlying anti-cancer molecular target of apigenin is still unclear. Therefore, to reveal the direct target and amino acid site of apigenin against colorectal cancer is the focus of this study. In the present study, the results proved that the anti-CRC activity of apigenin was positively correlated with pyruvate kinase M2 (PKM2) expression, characterized by the inhibition of cell proliferation and increase of apoptotic effects induced by apigenin in LS-174T cells of knock down PKM2. Next, pull-down and MALDI-TOF/TOF analysis determined that apigenin might interact directly with PKM2 in HCT-8 cells. Further, the study confirmed that lysine residue 433 (K433) was a key amino acid site for PKM2 binding to apigenin. Apigenin restricted the glycolysis of LS-174T and HCT-8 cells by targeting the K433 site of PKM2, thereby playing an anti-CRC role in vivo and in vitro. Meanwhile, apigenin markedly attenuated tumor growth without any adverse effects. Taken together, these findings reveal that apigenin is worthy of consideration as a promising PKM2 inhibitor for the prevention of CRC.

Research progress of hyperthermia in tumor therapy by influencing metabolic reprogramming of tumor cells

Cellular metabolic reprogramming is an important feature of malignant tumors. Metabolic reprogramming causes changes in the levels or types of specific metabolites inside and outside the cell, which affects tumorigenesis and progression by influencing gene expression, the cellular state, and the tumor microenvironment. During tumorigenesis, a series of changes in the glucose metabolism, fatty acid metabolism, amino acid metabolism, and cholesterol metabolism of tumor cells occur, which are involved in the process of cellular carcinogenesis and constitute part of the underlying mechanisms of tumor formation. Hyperthermia, as one of the main therapeutic tools for malignant tumors, has obvious effects on tumor cell metabolism. In this paper, we will combine the latest research progress in the field of cellular metabolic reprogramming and focus on the current experimental research and clinical treatment of hyperthermia in cellular metabolic reprogramming to discuss the feasibility of cellular metabolic reprogramming-related mechanisms guiding hyperthermia in malignant tumor treatment, so as to provide more ideas for hyperthermia to treat malignant tumors through the direction of cellular metabolic reprogramming.

Non-metabolic enzyme function of PKM2 in hepatocellular carcinoma: A review

Hepatocellular carcinoma (HCC) is one of the most malignant tumors with the highest incidence and mortality in the world, causing a serious burden on society. Pyruvate kinase M2 (PKM2) is one of the principal metabolic enzymes involved in glycolysis. Studies have shown that PKM2 is highly expressed in HCC and can be translocated to the nucleus, where it interacts with various transcription factors and proteins such as hypoxia-inducible factor-1α, sterol regulatory element-binding protein 1a, signal transducer and activator of transcription 3, nuclear factor erythroid 2-like 2 and histone H3, exerting non-metabolic enzyme functions to regulate the cell cycle, proliferation, apoptosis, immune escape, migration, and invasion, as well as HCC angiogenesis and tumor microenvironment. This review is focused on the recent progress of PKM2 interacting with various transcription factors and proteins affecting the onset and development of HCC, as well as natural drugs and noncoding RNA impacting diverse biological functions of liver cancer cells by regulating PKM2 non-metabolic enzyme functions, thereby providing valuable directions for the prognosis improvement and molecular targeted therapy of HCC in the future.

Intracellular spatiotemporal metabolism in connection to target engagement

The metabolism in eukaryotic cells is a highly ordered system involving various cellular compartments, which fluctuates based on physiological rhythms. Organelles, as the smallest independent sub-cell unit, are important contributors to cell metabolism and drug metabolism, collectively designated intracellular metabolism. However, disruption of intracellular spatiotemporal metabolism can lead to disease development and progression, as well as drug treatment interference. In this review, we systematically discuss spatiotemporal metabolism in cells and cell subpopulations. In particular, we focused on metabolism compartmentalization and physiological rhythms, including the variation and regulation of metabolic enzymes, metabolic pathways, and metabolites. Additionally, the intricate relationship among intracellular spatiotemporal metabolism, metabolism-related diseases, and drug therapy/toxicity has been discussed. Finally, approaches and strategies for intracellular spatiotemporal metabolism analysis and potential target identification are introduced, along with examples of potential new drug design based on this.

LincRNA-EPS Alleviates Inflammation in TMJ Osteoarthritis by Binding to SRSF3

Temporomandibular joint osteoarthritis (TMJOA) is a common inflammatory disease that can cause pain, cartilage degradation, and subchondral bone loss. However, the key regulatory factors and new targets for the treatment of TMJOA have yet to be determined. Long noncoding RNAs (lncRNAs) have shown remarkable potential in regulating tissue homeostasis and disease development. The long intergenic RNA-erythroid prosurvival (lincRNA-EPS) is reported to be an effective inhibitor of inflammation, but its role in TMJOA is unexplored. Here, we found that lincRNA-EPS is downregulated and negatively correlated with inflammatory factors in the condyles of TMJOA mice. LincRNA-EPS knockout aggravated inflammation and tissue destruction after TMJOA modeling. The in vitro studies confirmed that loss of lincRNA-EPS facilitated inflammatory factor expression in condylar chondrocytes, while recovered expression of lincRNA-EPS showed anti-inflammatory effects. Mechanistically, RNA sequencing revealed that the inflammatory response pathway nuclear factor-kappa B (NF-κB) was mostly affected by lincRNA-EPS deficiency. Moreover, lincRNA-EPS was proved to effectively bind to serine/arginine-rich splicing factor 3 (SRSF3) and inhibit its function in pyruvate kinase isoform M2 (PKM2) formation, thus restraining the PKM2/NF-κB pathway and the expression of inflammatory factors. In addition, local injection of the lincRNA-EPS overexpression lentivirus significantly alleviated inflammation, cartilage degradation, and subchondral bone loss in TMJOA mice. Overall, lincRNA-EPS regulated the inflammatory process of condylar chondrocytes by binding to SRSF3 and showed translational application potential in the treatment of TMJOA.

Role of Leptin and Adiponectin in Carcinogenesis

Hormones produced by adipocytes, leptin and adiponectin, are associated with the process of carcinogenesis. Both of these adipokines have well-proven oncologic potential and can affect many aspects of tumorigenesis, from initiation and primary tumor growth to metastatic progression. Involvement in the formation of cancer includes interactions with the tumor microenvironment and its components, such as tumor-associated macrophages, cancer-associated fibroblasts, extracellular matrix and matrix metalloproteinases. Furthermore, these adipokines participate in the epithelial-mesenchymal transition and connect to angiogenesis, which is critical for cancer invasiveness and cancer cell migration. In addition, an enormous amount of evidence has demonstrated that altered concentrations of these adipocyte-derived hormones and the expression of their receptors in tumors are associated with poor prognosis in various types of cancer. Therefore, leptin and adiponectin dysfunction play a prominent role in cancer and impact tumor invasion and metastasis in different ways. This review clearly and comprehensively summarizes the recent findings and presents the role of leptin and adiponectin in cancer initiation, promotion and progression, focusing on associations with the tumor microenvironment and its components as well as roles in the epithelial-mesenchymal transition and angiogenesis.

Polo-like kinase 1 promotes pulmonary hypertension

BACKGROUND

Pulmonary hypertension (PH) is a lethal vascular disease with limited therapeutic options. The mechanistic connections between alveolar hypoxia and PH are not well understood. The aim of this study was to investigate the role of mitotic regulator Polo-like kinase 1 (PLK1) in PH development.

METHODS

Mouse lungs along with human pulmonary arterial smooth muscle cells and endothelial cells were used to investigate the effects of hypoxia on PLK1. Hypoxia- or Sugen5416/hypoxia was applied to induce PH in mice. Plk1 heterozygous knockout mice and PLK1 inhibitors (BI 2536 and BI 6727)-treated mice were checked for the significance of PLK1 in the development of PH.

RESULTS

Hypoxia stimulated PLK1 expression through induction of HIF1α and RELA. Mice with heterozygous deletion of Plk1 were partially resistant to hypoxia-induced PH. PLK1 inhibitors ameliorated PH in mice.

CONCLUSIONS

Augmented PLK1 is essential for the development of PH and is a druggable target for PH.

Glycolytic enzyme PKM2 regulates cell senescence but not inflammation in the process of osteoarthritis

Chondrocyte senescence is an important mechanism underlying osteoarthritis in the senile population and is characterized by reduced expressions of the extracellular matrix proteins. The involvement of glycolysis and the tricarboxylic acid cycle in the development of osteoarthritis is inclusive. The present study aims to investigate the role of the glycolytic enzyme M2 isoform of pyruvate kinase (PKM2) in chondrocytes in senescence and inflammation. Primary chondrocytes are isolated from the knee joints of neonatal mice. Small interfering RNAs (siRNAs) against PKM2 are transfected using lipofectamine. RNA sequencing is conducted in primary chondrocytes with the PKM2 gene deleted. Cell apoptosis, autophagy, reactive oxygen species measurement, and senescent conditions are examined. The glycolytic rate in cells is measured by Seahorse examination. Interleukin 1-β (IL-1β) increases the protein expressions of matrix metallopeptidases (MMP)13 and PKM2 and reduces the protein expression of collagen type II (COL2A1) in primary chondrocytes. Silencing of PKM2 alters the protein expressions of MMP13, PKM2, and COL2A1 in the same pattern in quiescent and stimulated chondrocytes. RNA sequencing analysis reveals that PKM2 silencing reduces senescent biomarker p16 INK4a expression. Compared with low-passage chondrocytes, high-passage chondrocytes exhibit increased expression of p16 INK4a and reduced expression of COL2A1. Silencing of PKM2 reduces SA-β-Gal signals and increases COL2A1 expression in high-passage chondrocytes. Seahorse assay reveals that PKM2 deletion favors the tricarboxylic acid cycle in mitochondria in low- but not in high-passage chondrocytes. In summary, the glycolytic enzyme PMK2 modulates chondrocyte senescence but does not participate in the regulation of inflammation.

Pyruvate Kinase M2 Accelerates Cutaneous Wound Healing via Glycolysis and Wnt/β-Catenin Signaling

Cutaneous wound healing is a complex and dynamic process with high energy demand. The activation of glycolysis is essential for restoring the structure and function of injured tissues in wounds. Pyruvate kinase M2 (PKM2) is an enzyme that plays a crucial role in the last step of glycolysis. PKM2-mediated glycolysis is known to play an important role in diseases related to regeneration and inflammation. However, the role of PKM2 in wound healing has not been fully elucidated. In this study, we found that PKM2 expression and pyruvate kinase (PK) activity were increased with the activation of Wnt/β-catenin signaling during wound healing in mice. TEPP-46, an allosteric activator of PKM2, enhanced HaCaT human keratinocyte migration and cutaneous wound healing with an increment of PK activity. Moreover, we confirmed the effect of co-treatment with TEPP-46 and KY19382, a Wnt/β-catenin signaling activator through the interference with the CXXC-type zinc finger protein 5 (CXXC5) Dishevelled interaction, on wound healing. The combination treatment significantly accelerated wound healing, which was confirmed by the expression level of PCNA, keratin 14, and α-SMA. Furthermore, co-treatment induced angiogenesis in the wound beds. Overall, activation of both glycolysis and Wnt/β-catenin signaling has the potential to be used as a therapeutic approach for wound healing.

Important roles of Hif1a in maternal or adult BPA exposure induced pancreatic injuries

Bisphenol A (BPA) is a monomer to produce polycarbonate plastics and can be released into the environment through human activities, leading to its accumulation in animals, plants and humans through direct contact or environmental exposure. Epidemiological studies have reported that BPA exposure is associated with metabolic disorders. The pancreas is an important endocrine organ and plays an important role in metabolic disorders. To explore the possible long-term effects of BPA exposure on neonatal health, bioinformatic methods were used to identify differentially expressed genes (DEGs) by comparing the neonatal pancreas after maternal exposure to BPA with the adult pancreas after direct exposure to BPA. Two datasets about BPA exposure and pancreatic abnormality, GSE82175 and GSE126297 in Gene Expression Omnibus (GEO) at the National Center for Biotechnology Information (NCBI) were collected. Control (or BPA-exposed) offspring (maternal exposure) and Control (or BPA-exposed) adults (direct exposure) were defined as Control (or BPA) groups. The results showed that BPA disturbed the normal function of the pancreas in both offspring and adults, with offspring showing higher susceptibility to BPA than adults. Seventeen insulin secretion-related DEGs (Stxbp5l, Fam3d, Mia3, Igf1, Hif1a, Aqp1, Kif5b, Tiam1, Map4k4, Cyp51, Pde1c, Rab3c, Arntl, Clock, Edn3, Kcnb1, and Krt20) in the BPA group were identified, and 15 regulator DEGs (Zfp830, 4931431B13Rik, Egr1, Ddit4l, Cep55, G530011O06Rik, Hspa1b, Hspa1a, Cox6a2, Ibtk, Banf1, Slc35b2, Golt1b, Lrp8, and Pttg1) with opposite expression trends and a regulator gene Cerkl with the similar expression trend in the Control and BPA groups were identified. Hif1α might be an important molecular target for pancreatic cancer caused by BPA exposure, and pregnancy is a critical window of susceptibility to BPA exposure.

PDGF-BB/PDGFRβ induces tumour angiogenesis via enhancing PKM2 mediated by the PI3K/AKT pathway in Wilms' tumour

Platelet-derived growth factor receptor-β (PDGFRβ) is a critical type III receptor tyrosine kinase family member, which is involved in Wilms' tumour (WT) metastasis and aerobic glycolysis. The role of PDGFRβ in tumour angiogenesis has not been fully elucidated. Here, we examined the effect of PDGFRβ on angiogenesis in WT. First, the NCBI database integrated three datasets, GSE2712, GSE11151, and GSE73209, to screen differentially expressed genes. The R language was used to analyse the correlation between PDGFRB and vascular endothelial growth factor (VEGF). The results showed that PDGFRB, encoding PDGFRβ, was upregulated in WT, and its level was correlated with VEGFA expression. Next, PDGFRβ expression was inhibited by small interfering RNA (siRNA) or activated with the exogenous ligand PDGF-BB. The expression and secretion of the angiogenesis elated factor VEGFA in WT G401 cells were detected using Western blotting and ELISA, respectively. The effects of conditioned medium from G401 cells on endothelial cell viability, migration, invasion, the total length of the tube, and the number of fulcrums were investigated. To further explore the mechanism of PDGFRβ in the angiogenesis of WT, the expression of VEGFA was detected after blocking the phosphatidylinositol-3-kinase (PI3K) pathway and inhibiting the expression of PKM2, a key enzyme of glycolysis. The results indicated that PDGFRβ regulated the process of tumour angiogenesis through the PI3K/AKT/PKM2 pathway. Therefore, this study provides a novel therapeutic strategy to target PDGFRβ and PKM2 to inhibit glycolysis and anti-angiogenesis, thus, developing a new anti-vascular therapy.

NUSAP1-LDHA-Glycolysis-Lactate feedforward loop promotes Warburg effect and metastasis in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is characterized by hypoxia and hypovascular tumor microenvironment. Nucleolar and spindle associated protein 1 (NUSAP1) is a microtubule-associated protein that is known to be involved in cancer biology. Our study aimed to investigate the role of NUSAP1 in glycolytic metabolism and metastasis in PDAC. Expression and prognostic value of NUSAP1 in PDAC and common gastrointestinal tumors was evaluated. The function of NUSAP1 in PDAC progression was clarified by single-cell RNA-seq and further experiments in vitro, xenograft mouse model, spontaneous PDAC mice model and human tissue microarray. The downstream genes and signaling pathways regulated by NUSAP1 were explored by RNA-Seq. And the regulation of NUSAP1 on Lactate dehydrogenase A (LDHA)-mediated glycolysis and its underlying mechanism was further clarified by CHIP-seq. NUSAP1 was an independent unfavorable predictor of PDAC prognosis that playing a critical role in metastasis of PDAC by regulating LDHA-mediated glycolysis. Mechanically, NUSAP1 could bind to c-Myc and HIF-1α that forming a transcription regulatory complex localized to LDHA promoter region and enhanced its expression. Intriguingly, lactate upregulated NUSAP1 expression by inhibiting NUSAP1 protein degradation through lysine lactylated (Kla) modification, thus forming a NUSAP1-LDHA-glycolysis-lactate feedforward loop. The NUSAP1-LDHA-glycolysis-lactate feedforward loop is one of the underlying mechanisms to explain the metastasis and glycolytic metabolic potential in PDAC, which also provides a novel insights to understand the Warburg effect in cancer. Targeting NUSAP1 would be an attractive paradigm for PDAC treatment.

Functions of Key Enzymes of Glycolytic Metabolism in Tumor Microenvironment

The tumor microenvironment (TME) plays a crucial role in tumor initiation, growth and metastasis. Metabolic enzymes involved in tumor glycolytic reprogramming, including hexokinase, pyruvate kinase, and lactate dehydrogenase, not only play key roles in tumorigenesis and maintaining tumor cell survival, but also take part in the modulation of the TME. Many studies have been devoted to the role of key glycolytic enzymes in the TME over the past decades. We summarize the studies on the role of glycolytic enzymes in the TME of these years and found that glycolytic enzymes remodel the TME primarily through regulating immune escape, angiogenesis, and affecting stromal cells and exosomes. Notably, abnormal tumor vascular system, peritumoral stromal cells, and tumor immunosuppressive microenvironment are important contributors to the failure of antitumor therapy. Therefore, we discuss the mechanisms of regulation by key glycolytic enzymes that may contribute to a promising biomarker for therapeutic intervention. We argue that targeting key glycolytic enzymes in combination with antiprogrammed cell death ligand 1 or antivascular endothelial growth factor could emerge as the more integrated and comprehensive antitumor treatment strategy.

Development of isoselenazolium chlorides as selective pyruvate kinase isoform M2 inhibitors

Alterations in cancer metabolic pathways open up an opportunity for targeted and effective elimination of tumor cells. Pyruvate kinase M2 (PKM2) is predominantly expressed in proliferating cells and plays an essential role in directing glucose metabolism in cancer. Here, we report the design of novel class of selective PKM2 inhibitors as anti-cancer agents and their mechanism of action. Compound 5c being the most active with IC₅₀ = 0.35 ± 0.07 μM, also downregulates PKM2 mRNA expression, modulates mitochondrial functionality, induces oxidative burst and is cytotoxic for various cancer types. Isoselenazolium chlorides have an unusual mechanism of PKM2 inhibition, inducing a functionally deficient tetrameric assembly, while exhibiting a competitive inhibitor character. The discovery of robust PKM2 inhibitors not only offers candidates for anticancer therapy but is also crucial for studying the role of PKM2 in cancer.

Targeting tumor endothelial cells with methyltransferase inhibitors: Mechanisms of action and the potential of combination therapy

Tumor endothelial cells (TECs) reside in the inner lining of blood vessels and represent a promising target for targeted cancer therapy. DNA methylation is a chemical process that involves the transfer of a methyl group to a specific base in the DNA strand, catalyzed by DNA methyltransferase (DNMT). DNMT inhibitors (DNMTis) can inhibit the activity of DNMTs, thereby preventing the transfer of methyl groups from s-adenosyl methionine (SAM) to cytosine. Currently, the most viable therapy for TECs is the development of DNMTis to release cancer suppressor genes from their repressed state. In this review, we first outline the characteristics of TECs and describe the development of tumor blood vessels and TECs. Abnormal DNA methylation is closely linked to tumor initiation, progression, and cell carcinogenesis, as evidenced by numerous studies. Therefore, we summarize the role of DNA methylation and DNA methyltransferase and the therapeutic potential of four types of DNMTi in targeting TECs. Finally, we discuss the accomplishments, challenges, and opportunities associated with combination therapy with DNMTis for TECs.

PKM2/STAT1-mediated PD-L1 upregulation on neutrophils during sepsis promotes neutrophil organ accumulation by serving an anti-apoptotic role

BACKGROUND

Delayed neutrophil apoptosis during sepsis may impact neutrophil organ accumulation and tissue immune homeostasis. Elucidating the mechanisms underlying neutrophil apoptosis may help identify potential therapeutic targets. Glycolysis is critical to neutrophil activities during sepsis. However, the precise mechanisms through which glycolysis regulates neutrophil physiology remain under-explored, especially those involving the non-metabolic functions of glycolytic enzymes. In the present study, the impact of programmed death ligand-1 (PD-L1) on neutrophil apoptosis was explored. The regulatory effect of the glycolytic enzyme, pyruvate kinase M2 (PKM2), whose role in septic neutrophils remains unaddressed, on neutrophil PD-L1 expression was also explored.

METHODS

Peripheral blood neutrophils were isolated from patients with sepsis and healthy controls. PD-L1 and PKM2 levels were determined by flow cytometry and Western blotting, respectively. Dimethyl sulfoxide (DMSO)-differentiated HL-60 cells were stimulated with lipopolysaccharide (LPS) as an in vitro simulation of septic neutrophils. Cell apoptosis was assessed by annexin V/propidium iodide (annexin V/PI) staining, as well as determination of protein levels of cleaved caspase-3 and myeloid cell leukemia-1 (Mcl-1) by Western blotting. An in vivo model of sepsis was constructed by intraperitoneal injection of LPS (5 mg/kg) for 16 h. Pulmonary and hepatic neutrophil infiltration was assessed by flow cytometry or immunohistochemistry.

RESULTS

PD-L1 level was elevated on neutrophils under septic conditions. Administration of neutralizing antibodies against PD-L1 partially reversed the inhibitory effect of LPS on neutrophil apoptosis. Neutrophil infiltration into the lung and liver was also reduced in PD-L1-/- mice 16 h after sepsis induction. PKM2 was upregulated in septic neutrophils and promoted neutrophil PD-L1 expression both in vitro and in vivo. In addition, PKM2 nuclear translocation was increased after LPS stimulation, which promoted PD-L1 expression by directly interacting with and activating signal transducer and activator of transcription 1 (STAT1). Inhibition of PKM2 activity or STAT1 activation also led to increased neutrophil apoptosis.

CONCLUSION

In this study, a PKM2/STAT1-mediated upregulation of PD-L1 on neutrophils and the anti-apoptotic effect of upregulated PD-L1 on neutrophils during sepsis were identified, which may result in increased pulmonary and hepatic neutrophil accumulation. These findings suggest that PKM2 and PD-L1 could serve as potential therapeutic targets.

Sarsasapogenin, a principal active component absorbed into blood of total saponins of Anemarrhena, attenuates proliferation and invasion in rheumatoid arthritis fibroblast-like synoviocytes through downregulating PKM2 inhibited pathological glycolysis

Increased glycolytic in fibroblast-like synoviocytes (FLS) of rheumatoid arthritis (RA) not only contributes to early-stage disease pathogenesis but leads to sustained proliferation of FLS. Given the importance of PKM2 in glycolysis and apoptosis, PKM2 is considered a potential therapeutic and drug discovery target in RA. Total saponins of anemarrhena (TSA), a class of steroid saponins, originated from Anemarrhena asphodeloides Bge. In this study, we verified that 200 mg/kg TSA could significantly alleviate inflammation and the pathological characteristics of RA and inhibit synovial hyperplasia in AA rats. We confirmed that sarsasapogenin (SA) was the principal active ingredient absorbed into the blood of TSA by the UPLC/Q Exactive MS test. Then we used TNF-α-induced MH7A to get the conclusion that 20 μM SA could effectively inhibit the glycolysis by inhibiting the activity of PKM2 tetramer and glucose uptake. Moreover, 20 μM SA could suppress proliferation, migration, invasion, and cytokine release of FLS, interfere with the growth cycle of FLS, and induce FLS apoptosis by depressing the phosphorylation of PKM2. At last, In-1, a potent inhibitor of the PKM2 was used to reverse verify the above results. Taken together, the key mechanisms of SA on RA treatment through downregulating the activity of PKM2 tetramer and phosphorylation of PKM2 inhibited pathological glycolysis and induced apoptosis to exert inhibition on the proliferation and invasion of RA FLS.

Interpretable attention-based deep learning ensemble for personalized ovarian cancer treatment without manual annotations

Inhibition of pathological angiogenesis has become one of the first FDA approved targeted therapies widely tested in anti-cancer treatment, i.e. VEGF-targeting monoclonal antibody bevacizumab, in combination with chemotherapy for frontline and maintenance therapy for women with newly diagnosed ovarian cancer. Identification of the best predictive biomarkers of bevacizumab response is necessary in order to select patients most likely to benefit from this therapy. Hence, this study investigates the protein expression patterns on immunohistochemical whole slide images of three angiogenesis related proteins, including Vascular endothelial growth factor, Angiopoietin 2 and Pyruvate kinase isoform M2, and develops an interpretable and annotation-free attention based deep learning ensemble framework to predict the bevacizumab therapeutic effect on patients with epithelial ovarian cancer or peritoneal serous papillary carcinoma using tissue microarrays (TMAs). In evaluation with five-fold cross validation, the proposed ensemble model using the protein expressions of both Pyruvate kinase isoform M2 and Angiopoietin 2 achieves a notably high F-score (0.99±0.02), accuracy (0.99±0.03), precision (0.99±0.02), recall (0.99±0.02) and AUC (1.00±0). Kaplan-Meier progression free survival analysis confirms that the proposed ensemble is able to identify patients in the predictive therapeutic sensitive group with low cancer recurrence (p<0.001), and the Cox proportional hazards model analysis further confirms the above statement (p=0.012). In conclusion, the experimental results demonstrate that the proposed ensemble model using the protein expressions of both Pyruvate kinase isoform M2 and Angiopoietin 2 can assist treatment planning of bevacizumab targeted therapy for patients with ovarian cancer.

Regulative Roles of Metabolic Plasticity Caused by Mitochondrial Oxidative Phosphorylation and Glycolysis on the Initiation and Progression of Tumorigenesis

One important feature of tumour development is the regulatory role of metabolic plasticity in maintaining the balance of mitochondrial oxidative phosphorylation and glycolysis in cancer cells. In recent years, the transition and/or function of metabolic phenotypes between mitochondrial oxidative phosphorylation and glycolysis in tumour cells have been extensively studied. In this review, we aimed to elucidate the characteristics of metabolic plasticity (emphasizing their effects, such as immune escape, angiogenesis migration, invasiveness, heterogeneity, adhesion, and phenotypic properties of cancers, among others) on tumour progression, including the initiation and progression phases. Thus, this article provides an overall understanding of the influence of abnormal metabolic remodeling on malignant proliferation and pathophysiological changes in carcinoma.

Empagliflozin mediated miR-128-3p upregulation promotes differentiation of hypoxic cancer stem-like cells in breast cancer

AIMS

The hsa-miR-128-3p expression is downregulated in advanced breast cancer patients. Empagliflozin (EMPA) is an anti-diabetic drug with anticancer potential. The present study investigated the effect of EMPA on cancer cell differentiation by acting as a miR-128-3p mimicking drug in breast cancer.

MAIN METHODS

Our results first demonstrate SP1 and PKM2 as the downstream effectors of hsa-miR-128-3p. Further, transfection with siPKM2, miR-128-3p mimics, and inhibitors was performed to assess their involvement in cancer stemness using flow cytometry. Further, EMPA as miR-128-3p mimicking drug was screened and explored on cancer cell differentiation. Then, we treated the 4T1-Red-FLuc allograft breast tumor with EMPA to assess its inhibitory potential toward tumor growth using IVIS® Spectrum. Immunohistochemistry was performed to evaluate cancer cell differentiation and cell proliferation.

KEY FINDINGS

We found that hsa-miR-128-3p is the upstream regulator of SP1 and PKM2 in hypoxic breast cancer cells. Overexpression of miR-128-3p with mimics downregulate SP1 and PKM2, whereas miR-128-3p inhibitor shows an opposite effect. The enhanced expression of miR-128-3p and PKM2 knockdown diminishes hypoxia-induced CD44 expression and enhance CD44⁺/CD24⁺ differentiated cells. We also identified EMPA as the miR-128-3p mimicking drug that can enhance the differentiated cell population. Further, EMPA suppressed in vivo tumor growth, lung metastasis, tumor bioluminescence, and cell proliferation. Therefore, EMPA abrogates breast cancer stemness by inactivating SP1 and PKM2 via enhanced miR-128-3p expression.

SIGNIFICANCE

EMPA could be a promising drug in combination with other chemotherapeutic drugs in advanced breast cancer.

MYB sustains hypoxic survival of pancreatic cancer cells by facilitating metabolic reprogramming

Extensive desmoplasia and poor vasculature renders pancreatic tumors severely hypoxic, contributing to their aggressiveness and therapy resistance. Here, we identify the HuR/MYB/HIF1α axis as a critical regulator of the metabolic plasticity and hypoxic survival of pancreatic cancer cells. HuR undergoes nuclear-to-cytoplasmic translocation under hypoxia and stabilizes MYB transcripts, while MYB transcriptionally upregulates HIF1α. Upon MYB silencing, pancreatic cancer cells fail to survive and adapt metabolically under hypoxia, despite forced overexpression of HIF1α. MYB induces the transcription of several HIF1α-regulated glycolytic genes by directly binding to their promoters, thus enhancing the recruitment of HIF1α to hypoxia-responsive elements through its interaction with p300-dependent histone acetylation. MYB-depleted pancreatic cancer cells exhibit a dramatic reduction in tumorigenic ability, glucose-uptake and metabolism in orthotopic mouse model, even after HIF1α restoration. Together, our findings reveal an essential role of MYB in metabolic reprogramming that supports pancreatic cancer cell survival under hypoxia.

Inhibition of ATF4-mediated elevation of both autophagy and AKT/mTOR was involved in antitumorigenic activity of curcumin

Curcumin, a natural hydrophobic polyphenol, carries significant anticancer activity. The protein kinase B (AKT)/the mammalian target of the rapamycin (mTOR) pathway and autophagy are well known to be involved in carcinogenesis, and usually, inhibition of mTOR is the main reason to promote autophagy. In this study, however, autophagy and mTOR were found to be inhibited simultaneously by curcumin treatments, and both of them played an important role in the effect of curcumin on suppressing the growth of A549 cells. Tunicamycin (TM), the activator of Endoplasmic Reticulum (ER) stress, increased both autophagy and AKT/mTOR, while curcumin could significantly decrease TM-induced autophagy and AKT/mTOR. Furthermore, curcumin could inhibit TM-induced aerobic glycolysis in A549 cells, and decrease the level of cycle-related and migration-related proteins. Blocking activating transcription factor 4 (ATF4) by siRNA strongly reduced both the expression of autophagy-related proteins and AKT/mTOR. ChIP assay illustrated that ATF4 protein could bind to the promotor sequence of either ATG4B or AKT1. The transplantation tumor experiment showed that the weight and volume of the transplanted tumors were reduced significantly in the BALB/c mice subcutaneously injected with A549 cells treated with curcumin. Moreover, intranasal administration of curcumin decreased the protein level of autophagy, AKT/mTOR and ER stress in lung tissues of BALB/c mice. Taken together, our results demonstrated that inhibition of ER stress-dependent ATF4-mediated autophagy and AKT/mTOR pathway plays an important role in anticancer effect of curcumin.

Shikonin reverses pyruvate kinase isoform M2-mediated propranolol resistance in infantile hemangioma through reactive oxygen species-induced autophagic dysfunction

Infantile hemangioma (IH) is the most common benign tumor in infancy. Propranolol, a nonselective β-adrenergic receptor blocker, is now the first-line therapy for IH. Recently, low sensitivity to propranolol therapy has become one major reason for the failure of IH treatment. However, the exact underlying mechanisms are yet to be fully elucidated. Here, we reported that pyruvate kinase isoform M2 (PKM2), an essential glycolytic enzyme, played a critical role in regulating the progression of IH and the therapeutic resistance of propranolol treatment. Shikonin reversed the propranolol resistance in hemangioma-derived endothelial cells and in hemangioma animal models. Moreover, shikonin combined with propranolol could induce excessive reactive oxygen species (ROS) accumulation and lead to autophagic dysfunction, which is essential for the enhanced therapeutic sensitivity of propranolol treatment. Taken together, our results indicated that PKM2 has a significant role in hemangiomas progression and therapeutic resistance; it could be a safe and effective therapeutic strategy for those hemangiomas with poor propranolol sensitivity combined with shikonin.

YY1-induced upregulation of LncRNA-ARAP1-AS2 and ARAP1 promotes diabetic kidney fibrosis via aberrant glycolysis associated with EGFR/PKM2/HIF-1α pathway

Objectives: Dimeric pyruvate kinase (PK) M2 (PKM2) plays an important role in promoting the accumulation of hypoxia-inducible factor (HIF)-1α, mediating aberrant glycolysis and inducing fibrosis in diabetic kidney disease (DKD). The aim of this work was to dissect a novel regulatory mechanism of Yin and Yang 1 (YY1) on lncRNA-ARAP1-AS2/ARAP1 to regulate EGFR/PKM2/HIF-1α pathway and glycolysis in DKD. Materials and methods: We used adeno-associated virus (AAV)-ARAP1 shRNA to knocked down ARAP1 in diabetic mice and overexpressed or knocked down YY1, ARAP1-AS2 and ARAP1 expression in human glomerular mesangial cells. Gene levels were assessed by Western blotting, RT-qPCR, immunofluorescence staining and immunohistochemistry. Molecular interactions were determined by RNA pull-down, co-immunoprecipitation, ubiquitination assay and dual-luciferase reporter analysis. Results: YY1, ARAP1-AS2, ARAP1, HIF-1α, glycolysis and fibrosis genes expressions were upregulated and ARAP1 knockdown could inhibit dimeric PKM2 expression and partly restore tetrameric PKM2 formation, while downregulate HIF-1α accumulation and aberrant glycolysis and fibrosis in in-vivo and in-vitro DKD models. ARAP1 knockdown attenuates renal injury and renal dysfunction in diabetic mice. ARAP1 maintains EGFR overactivation in-vivo and in-vitro DKD models. Mechanistically, YY1 transcriptionally upregulates ARAP1-AS2 and indirectly regulates ARAP1 and subsequently promotes EGFR activation, HIF-1α accumulation and aberrant glycolysis and fibrosis. Conclusion: Our results first highlight the role of the novel regulatory mechanism of YY1 on ARAP1-AS2 and ARAP1 in promoting aberrant glycolysis and fibrosis by EGFR/PKM2/HIF-1α pathway in DKD and provide potential therapeutic strategies for DKD treatments.

The long noncoding RNA HOXA11-AS promotes lung adenocarcinoma proliferation and glycolysis via the microRNA-148b-3p/PKM2 axis

BACKGROUND

Lung cancer is the most common malignancy in the world and a growing number of researches have focused on its metabolic characteristics. Studies have shown that the long non-coding RNA (lncRNA) HOXA11-AS is aberrantly expressed in many tumors. However, the role of HOXA11-AS in lung adenocarcinoma (LUAD) glycolysis and other energy metabolism pathways has not been characterized.

METHOD

The mRNA levels of HOXA11-AS, microRNA-148b-3p (miR-148b-3p), and pyruvate kinase M2 (PKM2) were detected using qRT-PCR. The expression levels of proteins were measured using immunohistochemistry and western blot. The CCK-8, EdU, and colony formation assays were used to assess proliferation. Glycolytic changes were assessed by measuring lactate production, ATP production, and ¹⁸ F-FDG uptake. Bioinformatics analysis and dual-luciferase reporter assays were used to characterize the relationship between HOXA11-AS, miR-148b-3p, and PKM2. Proliferation and glycolytic changes were analyzed in xenograft tumor experiments using Micro-PET imaging after downregulation of HOXA11-AS in vivo.

RESULTS

The expression of HOXA11-AS was markedly increased in LUAD, and was strongly associated with a poor prognosis. In addition, HOXA11-AS promoted proliferation and glycolysis in LUAD, and miR-148b-3p inhibited proliferation and glycolysis in LUAD. Mechanistically, HOXA11-AS positively regulated PKM2 expression by binding to miR-148b-3p, thereby promoting LUAD proliferation and glycolysis. In addition, HOXA11-AS inhibited LUAD xenograft growth and glycolysis via upregulation of miR-148b-3p expression and downregulation of PKM2 expression in vivo.

CONCLUSIONS

These results showed that HOXA11-AS enhanced LUAD proliferation and glycolysis via the miR-148b-3p/PKM2 axis. The findings in this paper expanded our understanding of the molecular mechanisms of LUAD tumorigenesis and glycolysis and showed that HOXA11-AS could be useful as a diagnostic and prognostic marker for LUAD. ¹⁸ F-FDG PET/CT can be used to visually evaluate the therapeutic effect of targeting HOXA11-AS.

Negative correlation between serum pyruvate kinase M2 and cognitive function in patients with cerebral small vessel disease

OBJECTIVE

Cerebral small vessel disease (CSVD) is one of the main contributing factors to vascular cognitive impairment (VCI), with an increasing incidence rate. However, the genesis of CSVD cognitive impairment remains unknown. Inflammation and metabolic disorders are considered important pathogenesis of CSVD. In addition to acting as the key regulator of aerobic glycolysis, pyruvate kinase muscle isozyme 2 (PKM2) is a proinflammatory mediator transcriptional activator that can promote an inflammatory response. This study explored whether serum PKM2 is associated with cognitive impairment in CSVD patients.

METHODS

The demographic data, history of risk factors, laboratory data, and cognitive function scale assessment of 219 CSVD patients were analyzed, and the correlation between the CSVD clinical data and neuroimaging parameters with serum PKM2 was further explored. The serum PKM2 level was determined by enzyme-linked immunosorbent assay using the collected serum samples. Insulin resistance (IR) was assessed with reference to the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR). HOMA-IR was calculated using the formula HOMA-IR = fasting plasma glucose (FPG, mmol/L) × fasting insulin (FINS, μU/mL)/22.5. A binomial logistic regression model was referred to infer the risk factors for VCI, and the ability of serum PKM2 to diagnose VCI was assessed by using a ROC curve.

RESULTS

Serum PKM2 level was positively correlated with HOMA-IR (r = 0.206, P = 0.002), negatively correlated with MMSE and MOCA on the cognitive scale in CSVD patients, and higher in CSVD patients with white matter hyperintensities (WMH) (P < 0.001). When compared with patients without cognitive impairment, the serum PKM2 levels were elevated in cases with suspected dementia, mild dementia, mild to moderate dementia, and moderate to severe dementia, and the differences were statistically significant (P < 0.05). Serum PKM2 levels were correlated with cognitive screening test scores in CSVD.

CONCLUSION

The present findings indicated that the serum PKM2 level was positively correlated with HOMA-IR, WMH, and enlarged perivascular spaces and negatively correlated with cognitive function in CSVD patients.

Endothelial GLUTs and vascular biology

Endothelial metabolism is a promising target for vascular functional regulation and disease therapy. Glucose is the primary fuel for endothelial metabolism, supporting ATP generation and endothelial cell survival. Multiple studies have discussed the role of endothelial glucose catabolism, such as glycolysis and oxidative phosphorylation, in vascular functional remodeling. However, the role of the first gatekeepers of endothelial glucose utilization, glucose transporters, in the vasculature has long been neglected. Here, this review summarizes glucose transporter studies in vascular research. We mainly focus on GLUT1 and GLUT3 because they are the most critical glucose transporters responsible for most endothelial glucose uptake. Some interesting topics are also discussed, intending to provide directions for endothelial glucose transporter research in the future.

Modulating Glycolysis to Improve Cancer Therapy

Cancer cells undergo metabolic reprogramming and switch to a 'glycolysis-dominant' metabolic profile to promote their survival and meet their requirements for energy and macromolecules. This phenomenon, also known as the 'Warburg effect,' provides a survival advantage to the cancer cells and make the tumor environment more pro-cancerous. Additionally, the increased glycolytic dependence also promotes chemo/radio resistance. A similar switch to a glycolytic metabolic profile is also shown by the immune cells in the tumor microenvironment, inducing a competition between the cancer cells and the tumor-infiltrating cells over nutrients. Several recent studies have shown that targeting the enhanced glycolysis in cancer cells is a promising strategy to make them more susceptible to treatment with other conventional treatment modalities, including chemotherapy, radiotherapy, hormonal therapy, immunotherapy, and photodynamic therapy. Although several targeting strategies have been developed and several of them are in different stages of pre-clinical and clinical evaluation, there is still a lack of effective strategies to specifically target cancer cell glycolysis to improve treatment efficacy. Herein, we have reviewed our current understanding of the role of metabolic reprogramming in cancer cells and how targeting this phenomenon could be a potential strategy to improve the efficacy of conventional cancer therapy.

Honokiol inhibits interleukin-induced angiogenesis in the NSCLC microenvironment through the NF-κB signaling pathway

Tumor angiogenesis, which may be affected by microenvironmental inflammation and promotes tumor development and metastasis, is one of the key reasons contributing to increased mortality. The goal of this study is to investigate how lignin analogs, specifically honokiol (HNK), block angiogenesis induced by the inflammatory milieu of lung cancer. The human lung cancer cell lines A549 and H460 were treated with HNK. Interleukin-1 was employed to mimic an inflammatory tumor microenvironment. Findings demonstrated that HNK drastically decreased the cell viability of A549 and H460 cells. In A549 and H460 cells, HNK also reduced the production of vascular endothelial growth factor (VEGF), the most important marker of tumor angiogenesis. Signal pathway studies revealed that HNK blocked the NF-κB signaling pathway. This effect, in turn, prevented the expression of VEGF by inhibiting the NF-κB signaling pathway. Human umbilical vein endothelial cells (HUVECs) from A549-conditioned medium cultures were subjected to HNK treatment, which decreased tubulogenesis, horizontal and vertical migration, and cell proliferation in HUVECs. Overall, HNK inhibited the NF-κB pathway. This effect resulted in the downregulation of VEGF, thus reducing the viability and angiogenesis of human lung cancer cell lines. In A549 cell xenografts, HNK decreased VEGF expression, tumor angiogenesis, and tumor development. Our research shows that HNK is a potential antiangiogenic molecule for the treatment of lung cancer.

Biological and Clinical Impacts of Glucose Metabolism in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer type as it is prone to metastases and is difficult to diagnose at an early stage. Despite advances in molecular detection, its clinical prognosis remains poor and it is expected to become the second leading cause of cancer-related deaths. Approximately 85% of patients develop glucose metabolism disorders, most commonly diabetes mellitus, within three years prior to their pancreatic cancer diagnosis. Diabetes, or glucose metabolism disorders related to PDAC, are typically associated with insulin resistance, and beta cell damage, among other factors. From the perspective of molecular regulatory mechanisms, glucose metabolism disorders are closely related to PDAC initiation and development and to late invasion and metastasis. In particular, abnormal glucose metabolism impacts the nutritional status and prognosis of patients with PDAC. Meanwhile, preliminary research has shown that metformin and statins are effective for the prevention or treatment of malignancies; however, no such effect has been shown in clinical trials. Hence, the causes underlying these conflicting results require further exploration. This review focuses on the clinical significance of glucose metabolism disorders in PDAC and the mechanisms behind this relationship, while also summarizing therapeutic approaches that target glycolysis.

Hypoxia-mediated activation of hypoxia-inducible factor-1α in head and neck squamous cell carcinoma: A review

Since the 1950s, hypoxia has been recognized as a crucial characteristic of cancer cells and their microenvironment. Indeed, hypoxia promotes the growth, survival, and metastasis of cancer cells. In the early 1990s, we found that as many phenomena in hypoxia can occur through hypoxia-inducible factor-1α (HIF1α). HIF1α is known as an angiogenesis converter in hypoxia, which promotes tumorigenesis, development, immune escape, recurrence, etc; This page goes into great detail on how HIF1α is activated during hypoxia and how the 2 signaling channels interact. It specifically emphasizes the significance of reactive oxygen species, the function of the PI3K/the serine/threonine kinase Akt/mammalian target of rapamycin cascade, and outlines the similarities between the 2 important factors (reactive oxygen species and PI3K/the serine/threonine kinase Akt/mammalian target of rapamycin cascade), nuclear factor κB, for HIF1α Important implications, in an effort to offer fresh views for the treatment of head and neck squamous cell carcinoma and HIF1α research.

NF-κB mediated regulation of tumor cell proliferation in hypoxic microenvironment

Hypoxia is caused by a cancer-promoting milieu characterized by persistent inflammation. NF-κB and HIF-1α are critical participants in this transition. Tumor development and maintenance are aided by NF-κB, while cellular proliferation and adaptability to angiogenic signals are aided by HIF-1α. Prolyl hydroxylase-2 (PHD-2) has been hypothesized to be the key oxygen-dependent regulator of HIF-1α and NF-transcriptional B's activity. Without low oxygen levels, HIF-1α is degraded by the proteasome in a process dependent on oxygen and 2-oxoglutarate. As opposed to the normal NF-κB activation route, where NF-κB is deactivated by PHD-2-mediated hydroxylation of IKK, this method actually activates NF-κB. HIF-1α is protected from degradation by proteasomes in hypoxic cells, where it then activates transcription factors involved in cellular metastasis and angiogenesis. The Pasteur phenomenon causes lactate to build up inside the hypoxic cells. As part of a process known as lactate shuttle, MCT-1 and MCT-4 cells help deliver lactate from the blood to neighboring, non-hypoxic tumour cells. Non-hypoxic tumour cells use lactate, which is converted to pyruvate, as fuel for oxidative phosphorylation. OXOPHOS cancer cells are characterized by a metabolic switch from glucose-facilitated oxidative phosphorylation to lactate-facilitated oxidative phosphorylation. Although PHD-2 was found in OXOPHOS cells. There is no clear explanation for the presence of NF-kappa B activity. The accumulation of the competitive inhibitor of 2-oxo-glutarate, pyruvate, in non-hypoxic tumour cells is well established. So, we conclude that PHD-2 is inactive in non-hypoxic tumour cells due to pyruvate-mediated competitive suppression of 2-oxo-glutarate. This results in canonical activation of NF-κB. In non-hypoxic tumour cells, 2-oxoglutarate serves as a limiting factor, rendering PHD-2 inactive. However, FIH prevents HIF-1α from engaging in its transcriptional actions. Using the existing scientific literature, we conclude in this study that NF-κB is the major regulator of tumour cell growth and proliferation via pyruvate-mediated competitive inhibition of PHD-2.

Chemoselective Synthesis of Mannich Adducts from 1,4-Naphthoquinones and Profile as Autophagic Inducers in Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is a worldwide public health problem, accounting for approximately 90% of all oral cancers, and is the eighth most common cancer in men. Cisplatin and carboplatin are the main chemotherapy drugs used in the clinic. However, in addition to their serious side effects, such as damage to the nervous system and kidneys, there is also drug resistance. Thus, the development of new drugs becomes of great importance. Naphthoquinones have been described with antitumor activity. Some of them are found in nature, but semi synthesis has been used as strategy to find new chemical entities for the treatment of cancer. In the present study, we promote a multiple component reaction (MCR) among lawsone, arylaldehydes, and benzylamine to produce sixteen chemoselectively derivated Mannich adducts of 1,4-naphthoquinones in good yield (up to 97%). The antitumor activities and molecular mechanisms of action of these compounds were investigated in OSCC models and the compound 6a induced cytotoxicity in three different tumor cell lines (OSCC4, OSCC9, and OSCC25) and was more selective (IS > 2) for tumor cells than the chemotropic drug carboplatin and the controls lapachol and shikonin, which are chemically similar compounds with cytotoxic effects. The 6a selectively and significantly reduced the amount of cell colony growth, was not hemolytic, and tolerable in mice with no serious side effects at a concentration of 100 mg/kg with a LD50 of 150 mg/kg. The new compound is biologically stable with a profile similar to carboplatin. Morphologically, 6a does not induce cell retraction or membrane blebs, but it does induce intense vesicle formation and late emergence of membrane bubbles. Exploring the mechanism of cell death induction, compound 6a does not induce ROS formation, and cell viability was not affected by inhibitors of apoptosis (ZVAD) and necroptosis (necrostatin 1). Autophagy followed by a late apoptosis process appears to be the death-inducing pathway of 6a, as observed by increased viability by the autophagy inhibitor (3-MA) and by the appearance of autophagosomes, later triggering a process of late apoptosis with the presence of caspase 3/7 and DNA fragmentation. Molecular modeling suggests the ability of the compound to bind to topoisomerase I and II and with greater affinity to hPKM2 enzyme than controls, which could explain the mechanism of cell death by autophagy. Finally, the in-silico prediction of drug-relevant properties showed that compound 6a has a good pharmacokinetic profile when compared to carboplatin and doxorubicin. Among the sixteen naphthoquinones tested, compound 6a was the most effective and is highly selective and well tolerated in animals. The induction of cell death in OSCC through autophagy followed by late apoptosis possibly via inhibition of the PKM2 enzyme points to a promising potential of 6a as a new preclinical anticancer candidate.

Pyruvate kinase M2 mediates IL-17 signaling in keratinocytes driving psoriatic skin inflammation

Psoriasis is an inflammatory skin disease characterized by keratinocyte proliferation and inflammatory cell infiltration induced by IL-17. However, the molecular mechanism through which IL-17 signaling in keratinocytes triggers skin inflammation remains not fully understood. Pyruvate kinase M2 (PKM2), a glycolytic enzyme, has been shown to have non-metabolic functions. Here, we report that PKM2 mediates IL-17A signaling in keratinocytes triggering skin psoriatic inflammation. We find high expression of PKM2 in the epidermis of psoriatic patients and mice undergoing psoriasis models. Specific depletion of PKM2 in keratinocytes attenuates the development of experimental psoriasis by reducing the production of pro-inflammatory mediators. Mechanistically, PKM2 forms a complex with Act1 and TRAF6 regulating NF-κB transcriptional signaling downstream of the IL-17 receptor. As IL-17 also induces PKM2 expression in keratinocytes, our findings reveal a sustained signaling circuit critical for the psoriasis-driving effects of IL-17A, suggesting that PKM2 is a potential therapeutic target for psoriasis.

The significance of glycolysis in tumor progression and its relationship with the tumor microenvironment

It is well known that tumor cells rely mainly on aerobic glycolysis for energy production even in the presence of oxygen, and glycolysis is a known modulator of tumorigenesis and tumor development. The tumor microenvironment (TME) is composed of tumor cells, various immune cells, cytokines, and extracellular matrix, among other factors, and is a complex niche supporting the survival and development of tumor cells and through which they interact and co-evolve with other tumor cells. In recent years, there has been a renewed interest in glycolysis and the TME. Many studies have found that glycolysis promotes tumor growth, metastasis, and chemoresistance, as well as inhibiting the apoptosis of tumor cells. In addition, lactic acid, a metabolite of glycolysis, can also accumulate in the TME, leading to reduced extracellular pH and immunosuppression, and affecting the TME. This review discusses the significance of glycolysis in tumor development, its association with the TME, and potential glycolysis-targeted therapies, to provide new ideas for the clinical treatment of tumors.

circCYP24A1 facilitates esophageal squamous cell carcinoma progression through binding PKM2 to regulate NF-κB-induced CCL5 secretion

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is a common gastrointestinal malignant tumor, while the molecular mechanisms have not been fully elucidated. Multiple circular RNAs have been reported to involve in the onset and progression of malignant tumors through various molecular mechanisms. However, the clinical significance and functional mechanism of most circRNAs involved in the progression of ESCC remains obscure.

METHODS

RNA-Seq was used to explore potential circRNAs in participated in 5 pairs of ESCC and their corresponding normal esophageal tissues. The up-regulated circCYP24A1 was selected. Fluorescence in situ hybridization was cunducted to verificated the expression and intracellular localization of circCYP24A1 by using the tissue microarray. The Kaplan-Meier method and Cox proportional hazards model was used to examine the potential prognostic value of circCYP24A1 on overall survival of ESCC patients. The biological function were confirmed by gain- and loss-of-function approaches in vivo. mRNA expression profile microarray was proformed to investigate the downstream signaling pathways involved in circCYP24A1. RNA pull-down assay and mass spectrometry were performed to identify the proteins associated with circCYP24A1. Rescue experiments were carried out to identified hypothetical regulatory role of circCYP24A1 on ESCC progression in vivo and in virto.

RESULTS

In this study, we identified circCYP24A1 in ESCC tissues by RNA sequencing, which is up-regulated in 114 cases of ESCC tissues and acts as a novel prognosis-related factor. Moreover, circCYP24A1 promoted the ability of proliferation, migration, invasion and clone formation in vitro, as well as tumor growth in vivo. Mechanistically, chemokine (C-Cmotif) ligand 5 (CCL5) is functional downstream mediator for circCYP24A1, which is screened by mRNA microarray. Moreover, circCYP24A1 physically interacts with M2 isoform of pyruvate kinase (PKM2). Rescue experiments showed that PKM2 knockdown partly reverses the promotional effects of circCYP24A1. It was revealed that circCYP24A1 increases secretion of CCL5 through the mechanism mainly by interacting with PKM2, an activator of NF-κB pathway, and thereby accelerate malignant progression of ESCC.

CONCLUSIONS

Up-regulated circCYP24A1 could activate NF-κB pathway by binding PKM2, which promotes the secretion of CCL5 and accelerate malignant progression of ESCC. Our fndings recommended a novel function for circCYP24A1 as a potential effective biomarker for judging prognosis and a therapeutic target in ESCC.

A functional loop between YTH domain family protein YTHDF3 mediated m6A modification and phosphofructokinase PFKL in glycolysis of hepatocellular carcinoma

BACKGROUND & AIMS

N⁶-methyladenosine (m⁶A) modification plays a critical role in progression of hepatocellular carcinoma (HCC), and aerobic glycolysis is a hallmark of cancer including HCC. However, the role of YTHDF3, one member of the core readers of the m⁶A pathway, in aerobic glycolysis and progression of HCC is still unclear.

METHODS

Expression levels of YTHDF3 in carcinoma and surrounding tissues of HCC patients were evaluated by immunohistochemistry. Loss and gain-of-function experiments in vitro and in vivo were used to assess the effects of YTHDF3 on HCC cell proliferation, migration and invasion. The role of YTHDF3 in hepatocarcinogenesis was observed in a chemically induced HCC model with Ythdf3^-/- mice. Untargeted metabolomics and glucose metabolism phenotype assays were performed to evaluate relationship between YTHDF3 and glucose metabolism. The effect of YTHDF3 on PFKL was assessed by methylated RNA immunoprecipitation assays (MeRIP). Co-immunoprecipitation and immunofluorescence assays were performed to investigate the connection between YTHDF3 and PFKL.

RESULTS

We found YTHDF3 expression was greatly upregulated in carcinoma tissues and it was correlated with poor prognosis of HCC patients. Gain-of-function and loss-of-function assays demonstrated YTHDF3 promoted proliferation, migration and invasion of HCC cells in vitro, and YTHDF3 knockdown inhibited xenograft tumor growth and lung metastasis of HCC cells in vivo. YTHDF3 knockout significantly suppressed hepatocarcinogenesis in chemically induced mice model. Mechanistically, YTHDF3 promoted aerobic glycolysis by promoting phosphofructokinase PFKL expression at both mRNA and protein levels. MeRIP assays showed YTHDF3 suppressed PFKL mRNA degradation via m⁶A modification. Surprisingly, PFKL positively regulated YTHDF3 protein expression, not as a glycolysis rate-limited enzyme, and PFKL knockdown effectively rescued the effects of YTHDF3 overexpression on proliferation, migration and invasion ability of Sk-Hep-1 and HepG2 cells. Notably, co-immunoprecipitation assays demonstrated PFKL interacted with YTHDF3 via EFTUD2, a core subunit of spliceosome involved in pre-mRNA splicing process, and ubiquitination assays showed PFKL could positively regulate YTHDF3 protein expression via inhibiting ubiquitination of YTHDF3 protein by EFTUD2.

CONCLUSIONS

our study uncovers the key role of YTHDF3 in HCC, characterizes a positive functional loop between YTHDF3 and phosphofructokinase PFKL in glucose metabolism of HCC, and suggests the connection between pre-mRNA splicing process and m⁶A modification.

Reregulated mitochondrial dysfunction reverses cisplatin resistance microenvironment in colorectal cancer

Chemotherapy is one of the most basic and important treatments for malignant tumors. However, most chemotherapeutic drugs suffer from the resistance of tumor cells and lead to chemotherapy failure. Multidrug resistance (MDR) of tumor cells is the main obstacle to chemotherapy failure. The generation of MDR is not only the result of the performance of tumor cells, but the tumor microenvironment (TEM) also plays an important role in this process. The simultaneous dual intervention of cancer cells and the TEM has the potential to provide surprising results in overcoming MDR tumor therapy. Therefore, in this study, we designed a folate acid ligand-modified nanoparticle (FA-NPs) with a size of about 145 nm targeting multidrug-resistant colorectal cancer and successfully co-loaded cisplatin and Tris(2-chloroisopropyl) phosphate (TCPP). FA-NPs can enrich tumor sites through receptor-mediated endocytosis. In vitro mechanism studies have shown that nanoparticles can reverse cisplatin resistance mainly by further increasing the level of reactive oxygen species in tumor cells, breaking the homeostasis of the internal environment, then trigging mitochondrial stress, regulating drug resistance-related pathways, and improving the tumor drug resistance microenvironment; finally, the cisplatin recovers the antitumor effect with assistance from TCPP.

Caveolin-1 suppresses hippocampal neuron apoptosis via the regulation of HIF1α in hypoxia in naked mole-rats

Naked mole-rats (NMRs) (Heterocephalus glaber) are highly social and subterranean rodents with large communal colonies in burrows containing low oxygen levels. The inhibition of severe hypoxic conditions is of particular interest to this study. To understand the mechanisms that facilitate neuronal preservation during hypoxia, we investigated the proteins regulating hypoxia tolerance in NMR hippocampal neurons. Caveolin-1 (Cav-1), a transmembrane scaffolding protein, confers prosurvival signalling in the central nervous system. The present study aimed to investigate the role of Cav-1 in hypoxia-induced neuronal injury. Western blotting analysis and immunocytochemistry showed that Cav-1 expression was significantly upregulated in NMR hippocampal neurons under 8% O₂ conditions for 8 h. Cav-1 alleviates apoptotic neuronal death from hypoxia. Downregulation of Cav-1 by lentiviral vectors suggested damage to NMR hippocampal neurons under hypoxic conditions in vitro and in vivo. Overexpression of Cav-1 by LV-Cav-1 enhanced hypoxic tolerance of NMR hippocampal neurons in vitro and in vivo. Mechanistically, the levels of hypoxia inducible factor-1α (HIF-1α) are also increased under hypoxic conditions. After inhibiting the binding of HIF-1α to hypoxia response elements in the DNA by echinomycin, Cav-1 levels were downregulated significantly. Furthermore, chromatin immunoprecipitation assays showed the direct role of HIF1α in regulating the expression levels of Cav-1 in NMR hippocampal neurons under hypoxic conditions. These findings suggest that Cav-1 plays a critical role in modulating the apoptosis of NMR hippocampal neurons and warrant further studies targeting Cav-1 to treat hypoxia-associated brain diseases.

Gut fungi enhances immunosuppressive function of myeloid-derived suppressor cells by activating PKM2-dependent glycolysis to promote colorectal tumorigenesis

Background

Accumulating evidence implicates that gut fungi are associated with the pathogenesis of colorectal cancer (CRC). Our previous study has revealed that Candida tropicalis (C. tropicalis) promotes colorectal tumorigenesis by enhancing immunosuppressive function of myeloid-derived suppressor cells (MDSCs) and increasing accumulation of MDSCs, but the underlying mechanisms remain unestablished.

Methods

Bone marrow–derived MDSCs were stimulated with C. tropicalis. RNA-sequencing analysis was performed to screen the differentially expressed genes. Quantitative real-time PCR and western blot were used to measure the expression of related proteins. Co-culture assay of MDSCs and CD8+ T cells was used to determine the immunosuppressive ability of MDSCs. Metabolomic analysis was conducted to detect metabolic reprogramming of MDSCs. Aerobic glycolysis of MDSCs was assessed by extracellular acidification rate (ECAR), glucose consumption and lactate production. A CAC mouse model was induced by AOM and DSS to determine the therapeutic action of TEPP-46. IHC and immunofluorescence were performed to examine the expression of PKM2, PKM2 (p-Y105) and iNOS in human CRC-infiltrated MDSCs.

Results

C. tropicalis facilitates immunosuppressive function of MDSCs by increasing the expression of iNOS, COX2 and NOX2, production of nitric oxide (NO) and reactive oxygen species (ROS). Mechanistically, C. tropicalis facilitates the immunosuppressive function of MDSCs through the C-type lectin receptors Dectin-3 and Syk. C. tropicalis-enhanced immunosuppressive function of MDSCs is further dependent on aerobic glycolysis. On the one hand, NO produced by MDSCs enhanced aerobic glycolysis in a positive feedback manner. On the other hand, C. tropicalis promotes p-Syk binding to PKM2, which results in PKM2 Tyr105 phosphorylation and PKM2 nuclear translocation in MDSCs. Nuclear PKM2 interacts with HIF-1α and subsequently upregulates the expression of HIF-1α target genes encoding glycolytic enzymes, GLUT1, HK2, PKM2, LDHA and PDK1, which are required for the C. tropicalis-induced aerobic glycolysis of MDSCs. Blockade of PKM2 nuclear translocation attenuates C. tropicalis-mediated colorectal tumorigenesis. The high expression of PKM2, PKM2 (p-Y105) and iNOS in CRC-infiltrated MDSCs correlates with the development of human CRC.

Conclusion

C. tropicalis enhances immunosuppressive function of MDSCs via Syk-PKM2-HIF-1α-glycolysis signaling axis, which drives CRC. Therefore, we identify the Syk-PKM2-HIF-1α-glycolysis signaling axis as a potential therapeutic target for CRC.

Orchestration of mesenchymal plasticity and immune evasiveness via rewiring of the metabolic program in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is the most fatal cancer in humans, due to its difficulty of early detection and its high metastatic ability. The occurrence of epithelial to mesenchymal transition in preinvasive pancreatic lesions has been implicated in the early dissemination, drug resistance, and cancer stemness of PDAC. PDAC cells also have a reprogrammed metabolism, regulated by driver mutation-mediated pathways, a desmoplastic tumor microenvironment (TME), and interactions with stromal cells, including pancreatic stellate cells, fibroblasts, endothelial cells, and immune cells. Such metabolic reprogramming and its functional metabolites lead to enhanced mesenchymal plasticity, and creates an acidic and immunosuppressive TME, resulting in the augmentation of protumor immunity via cancer-associated inflammation. In this review, we summarize our recent understanding of how PDAC cells acquire and augment mesenchymal features via metabolic and immunological changes during tumor progression, and how mesenchymal malignancies induce metabolic network rewiring and facilitate an immune evasive TME. In addition, we also present our recent findings on the interesting relevance of the small G protein ADP-ribosylation factor 6-based signaling pathway driven by KRAS/TP53 mutations, inflammatory amplification signals mediated by the proinflammatory cytokine interleukin 6 and RNA-binding protein ARID5A on PDAC metabolic reprogramming and immune evasion, and finally discuss potential therapeutic strategies for the quasi-mesenchymal subtype of PDAC.

Role of hypoxia in the tumor microenvironment and targeted therapy

Tumor microenvironment (TME), which is characterized by hypoxia, widely exists in solid tumors. As a current research hotspot in the TME, hypoxia is expected to become a key element to break through the bottleneck of tumor treatment. More and more research results show that a variety of biological behaviors of tumor cells are affected by many factors in TME which are closely related to hypoxia. In order to inhibiting the immune response in TME, hypoxia plays an important role in tumor cell metabolism and anti-apoptosis. Therefore, exploring the molecular mechanism of hypoxia mediated malignant tumor behavior and therapeutic targets is expected to provide new ideas for anti-tumor therapy. In this review, we discussed the effects of hypoxia on tumor behavior and its interaction with TME from the perspectives of immune cells, cell metabolism, oxidative stress and hypoxia inducible factor (HIF), and listed the therapeutic targets or signal pathways found so far. Finally, we summarize the current therapies targeting hypoxia, such as glycolysis inhibitors, anti-angiogenesis drugs, HIF inhibitors, hypoxia-activated prodrugs, and hyperbaric medicine.

COMMD3 Expression Affects Angiogenesis through the HIF1α/VEGF/NF-κB Signaling Pathway in Hepatocellular Carcinoma In Vitro and In Vivo

Background

High expression of copper metabolizing MURR1 domain (COMMD3) is significantly correlated with poor prognosis in hepatocellular carcinoma (HCC) patients. Here, we explored the mechanism by which COMMD3 affects HCC angiogenesis through the HIF1α/VEGF/NF-κB signaling pathway.

Methods

SK-Hep1 and Hep-3B cell lines were transfected by COMMD3 overexpression and RNA interference lentivirus and verified using RT-qPCR and western blotting techniques. Using RNA sequencing, we analyzed differentially expressed genes in COMMD3-overexpressed and COMMD3-knockdown HCC cells. Altogether, colony formation assay, wound healing assay, transwell cell invasion assay, flow cytometry apoptosis experiments, HUVEC tube formation detection, phalloidin staining assay, western blotting, immunohistochemical staining, and a nude mouse xenograft model were used for experimental verification.

Results

Lentivirus COMMD3 overexpression and knockdown were successfully established in HCC cells. COMMD3 overexpression significantly promoted the proliferation, angiogenesis, migration, and invasion capacities of HCC cells with no obvious effect on apoptosis versus controls while COMMD3 knockdown showed the opposite trend. The expression and protein levels of COMMD3 as well as HIF1α, VEGF, and NF-κB were increased in COMMD3-overexpressing HCC cells versus control cells, while they were reduced after COMMD3 knockdown. In addition, RNA-seq indicated that COMMD3 is an indispensable gene for HCC angiogenesis through HIF1α and NF-κB signaling pathways.

Conclusion

This study showed that low expression of COMMD3 can inhibit HCC angiogenesis by suppressing the HIF1α/VEGF/NF-κB pathway. This implicates COMMD3 as a potential biomarker for improving the therapeutic outcome of HCC.

Attenuation of placental pyruvate kinase M2 promotes oxidative imbalance and enhances inflammatory- apoptosis cross talk in rats with hyperhomocysteinemia associated pregnancy loss.. [DOI: 10.21203/rs.3.rs-1997950/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

10-15% of clinically recognized pregnancies end in miscarriage. Hyperhomocysteinemia in pregnant women has been associated with deep venous thrombosis, recurrent miscarriage, preeclampsia to name a few. Impaired placental function due to overt oxidative stress is one of the key mechanisms in development of pregnancy loss. Paucity of pathway–based microarray approach in embryonic–endometrial communication warrants elucidation of distinct profile of miRNAs in hyperhomocysteinemia-associated pregnancy loss (HAPL). Hyperhomocysteinemia was induced at a dose of 100mg/kg body-weight/day for D1-D18 of pregnancy. Placental histology by haematoxylin-eosin staining documented thrombus with reduced area of spongiotropoblasts in chorionic plate vessel. Placental mRNA was subjected to microarray analysis followed by pathway-analysis using Ingenuity Pathway Analysis (IPA). Genes involved in reproductive physiology, inflammatory pathways, immune responses, homocysteine metabolism, glucose metabolism, and oxidative stress were differentially expressed in HAPL. 21 pathways documented by IPA, were skewed to 10 by recursive feature elimination highlighting possible deregulation/s. Expression/s was re-confirmed by quantitative real- time PCR (qRT-PCR), western blot and flow cytometric analysis (FACS). Nine priori molecules (PKM2, AKT, PI3K, NF-κB, COX-2, sflt-1, HIF-1α, bax, caspase 9) were specifically modulated in HAPL as demonstrated by protein and mRNA expression. A parallel increase in insulin signaling (PI3K+,AKT+), inflammation (COX2+,NF-κB+), hypoxia (sflt-1+,HIF-1α+), apoptosis (bax+,caspase9+) with concomitant decrease in pyruvate kinase M2 in hyperhomocysteinemic placental cells by FACS with CD56, a marker for pregnancy loss was documented. The findings provide evidence that an oxidative stress-mediated placental damage perhaps represents the pathogenesis of HAPL, which may explore pathway-based therapeutic options for recurrent miscarriage.10–15% of clinically recognized pregnancies end in miscarriage. Hyperhomocysteinemia in pregnant women has been associated with deep venous thrombosis, recurrent miscarriage, preeclampsia to name a few. Impaired placental function due to overt oxidative stress is one of the key mechanisms in development of pregnancy loss. Paucity of pathway–based microarray approach in embryonic–endometrial communication warrants elucidation of distinct profile of miRNAs in hyperhomocysteinemia-associated pregnancy loss (HAPL). Hyperhomocysteinemia was induced at a dose of 100mg/kg body-weight/day for D1-D18 of pregnancy. Placental histology by haematoxylin-eosin staining documented thrombus with reduced area of spongiotropoblasts in chorionic plate vessel. Placental mRNA was subjected to microarray analysis followed by pathway-analysis using Ingenuity Pathway Analysis (IPA). Genes involved in reproductive physiology, inflammatory pathways, immune responses, homocysteine metabolism, glucose metabolism, and oxidative stress were differentially expressed in HAPL. 21 pathways documented by IPA, were skewed to 10 by recursive feature elimination highlighting possible deregulation/s. Expression/s was re-confirmed by quantitative real- time PCR (qRT-PCR), western blot and flow cytometric analysis (FACS). Nine priori molecules (PKM2, AKT, PI3K, NF-κB, COX-2, sflt-1, HIF-1α, bax, caspase 9) were specifically modulated in HAPL as demonstrated by protein and mRNA expression. A parallel increase in insulin signaling (PI3K+,AKT+), inflammation (COX2+,NF-κB+), hypoxia (sflt-1+,HIF-1α+), apoptosis (bax+,caspase9+) with concomitant decrease in pyruvate kinase M2 in hyperhomocysteinemic placental cells by FACS with CD56, a marker for pregnancy loss was documented. The findings provide evidence that an oxidative stress-mediated placental damage perhaps represents the pathogenesis of HAPL, which may explore pathway-based therapeutic options for recurrent miscarriage.