PFKFB3 is involved in breast cancer proliferation, migration, invasion and angiogenesis

Size-Specific Modulation of a Multienzyme Glucosome Assembly during the Cell Cycle

Enzymes in glucose metabolism have been subjected to numerous studies, revealing the importance of their biological roles during the cell cycle. However, due to the lack of viable experimental strategies for measuring enzymatic activities particularly in living human cells, it has been challenging to address whether their enzymatic activities and thus anticipated glucose flux are directly associated with cell cycle progression. It has remained largely elusive how human cells regulate glucose metabolism at a subcellular level to meet the metabolic demands during the cell cycle. Meanwhile, we have characterized that rate-determining enzymes in glucose metabolism are spatially organized into three different sizes of multienzyme metabolic assemblies, termed glucosomes, to regulate the glucose flux between energy metabolism and building block biosynthesis. In this work, we first determined using cell synchronization and flow cytometric techniques that enhanced green fluorescent protein-tagged phosphofructokinase is adequate as an intracellular biomarker to evaluate the state of glucose metabolism during the cell cycle. We then applied fluorescence single-cell imaging strategies and discovered that the percentage of Hs578T cells showing small-sized glucosomes is drastically changed during the cell cycle, whereas the percentage of cells with medium-sized glucosomes is significantly elevated only in the G1 phase, but the percentage of cells showing large-sized glucosomes is barely or minimally altered along the cell cycle. Should we consider our previous localization-function studies that showed assembly size-dependent metabolic roles of glucosomes, this work strongly suggests that glucosome sizes are modulated during the cell cycle to regulate glucose flux between glycolysis and building block biosynthesis. Therefore, we propose the size-specific modulation of glucosomes as a behind-the-scenes mechanism that may explain functional association of glucose metabolism with the cell cycle and, thereby, their metabolic significance in human cell biology.

Expression of Pfkfb isoenzymes during in vitro differentiation of mouse embryonic stem cells into insulin-producing cells

Background/aim

Type 1 diabetes mellitus (T1DM) is caused by the autoimmune-mediated destruction of insulin-producing cells (IPCs) and still has no effective cure. Better understanding of the molecular mechanisms involved in the differentiation of embryonic stem cells (ESCs) into IPCs may help us improve the therapeutic strategies for treating T1DM. 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatases (Pfkfb1-4) are key regulators of glucose metabolism. Although Pfkfb3 has been shown to be required for the growth of early differentiated mouse ESCs (mESCs), more studies are needed to further assess the roles of Pfkfb isoenzymes in embryonic development and differentiation, particularly into specific cell types. In this study, we aimed to elucidate the changes in the expression of Pfkfb isoenzymes on the differentiation of mESCs into IPCs.

Materials and methods

A 3-step protocol was used to differentiate R1 and J1 mESCs into IPCs. The changes in the gene expression of MafA, MafB, Ins2, and Nkx6.1 (IPC specific markers) and Pfkfb1-4 were analyzed using real-time quantitative polymerase chain reaction (qPCR). Insulin expression and secretion were determined by immunofluorescence (IF) staining and the enzyme linked immunosorbent assay (ELISA), respectively.

Results

Upon differentiation, the IPC specific markers in differentiated cells were upregulated. Continued differentiation was confirmed by the development of insulin-positive islet-like clusters that secreted insulin in response to glucose uptake. Expressions of the Pfkfb2 and Pfkfb3 isoenzymes were markedly increased in various stages of differentiation.

Conclusion

These findings suggest that Pfkfb2 and Pfkfb3 may impact the differentiation of mESCs into IPCs and the regulation of the insulin response to glucose levels. This study also lays a foundation for researchers to further probe the roles of Pfkfb isoenzymes on the differentiation of mESCs into IPCs and may open new avenues for regenerative medicine.

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.

Metabolism in Cancer Stem Cells: Targets for Clinical Treatment

Cancer stem cells (CSCs) have high tumorigenicity, high metastasis and high resistance to treatment. They are the key factors for the growth, metastasis and drug resistance of malignant tumors, and are also the important reason for the occurrence and recurrence of tumors. Metabolic reprogramming refers to the metabolic changes that occur when tumor cells provide sufficient energy and nutrients for themselves. Metabolic reprogramming plays an important role in regulating the growth and activity of cancer cells and cancer stem cells. In addition, the immune cells or stromal cells in the tumor microenvironment (TME) will change due to the metabolic reprogramming of cancer cells. Summarizing the characteristics and molecular mechanisms of metabolic reprogramming of cancer stem cells will provide new ideas for the comprehensive treatment of malignant tumors. In this review, we summarized the changes of the main metabolic pathways in cancer cells and cancer stem cells.

A miR-34a-guided, tRNAiMet-derived, piR_019752-like fragment (tRiMetF31) suppresses migration and angiogenesis of breast cancer cells via targeting PFKFB3

Although we recently demonstrated that miR-34a directly targets tRNA_i^Met precursors via Argonaute 2 (AGO2)-mediated cleavage, consequently attenuating the proliferation of breast cancer cells, whether tRNA_i^Met fragments derived from this cleavage influence breast tumor angiogenesis remains unknown. Here, using small-RNA-Seq, we identified a tRNA_i^Met-derived, piR_019752-like 31-nt fragment tRiMetF31 in breast cancer cells expressing miR-34a. Bioinformatic analysis predicted 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3) as a potential target of tRiMrtF31, which was validated by luciferase assay. tRiMetF31 was downregulated, whereas PFKFB3 was overexpressed in cancer cell lines. Overexpression of tRiMetF31 profoundly inhibited the migration and angiogenesis of two breast cancer cell lines while slightly inducing apoptosis. Conversely, knockdown of tRiMetF31 restored PFKFB3-driven angiogenesis. miR-34a was downregulated, whereas tRNA_i^Met and PFKFB3 were upregulated in breast cancer, and elevated PFKFB3 significantly correlated with metastasis. Our findings demonstrate that tRiMetF31 profoundly suppresses angiogenesis by silencing PFKFB3, presenting a novel target for therapeutic intervention in breast cancer.

Construction of Glycolytic Regulator Gene Signature to Predict the Prognosis and Tumor Immune Cell Infiltration Levels for Prostate Cancer

Prostate cancer (PCa) is the commonly generated noncutaneous neoplasm among men worldwide. Glycolysis had been validated to promote cancer progression. However, the clinical significance of glycolytic regulators in PCa was not well understood. Here, we discovered that glycolytic regulators were dysregulated in PCa samples using GSE8511, GSE6919, and GEPIA. By detecting the expression of these regulators in PCa samples, we found that SLC2A1, SLC2A3, HK2, PFKFB2, TPI1, PKM2, and LDHA had higher expression in PCa compared with normal tissues. Moreover, both higher expression of TPI1, ALDOA, ENO1, LDHA, and PKM and lower expression of LDHB and HK2 were significantly related to shorter progression-free survival time in PCa. Of note, an 8 gene-based risk score was further constructed and confirmed to have a good performance in predicting progression-free survival (PFS) time in PCa. The signature risk score significantly correlated with NK cell, neutrophil cell, macrophage M2 cell, and myeloid dendritic cell infiltration levels in PCa. After bioinformatics analysis, our data suggested glycolytic regulators participated in the regulation of multiple nonmetabolic biological processes, such as RNA transport, biosynthesis of antibiotics, and cell cycle. We recapitulate that the glycolytic regulator signature was a prospective indicator for prognosis and immune cell infiltration levels in PCa.

PFKFB3 Regulates Chemoresistance, Metastasis and Stemness via IAP Proteins and the NF-κB Signaling Pathway in Ovarian Cancer

Glycolysis has been reported to be critical for cancer stem cells (CSCs), which are associated with tumor chemoresistance, metastasis and recurrence. Thus, selectively targeting glycolytic enzymes may be a potential therapy for ovarian cancer. 6‐phosphofructo‐2‐kinase/fructose‐2,6‐biphosphatase 3 (PFKFB3), the main source of fructose-2,6-bisphosphate, controls the first committed step in glycolysis. We investigate the clinical significance and roles of PFKFB3 in ovarian cancer using in vitro and in vivo experiments. We demonstrate that PFKFB3 is widely overexpressed in ovarian cancer and correlates with advanced stage/grade and poor outcomes. Significant up-regulation of PFKFB3 was found in ascites and metastatic foci, as well as CSC-enriched tumorspheres and ALDH+CD44+ cells. 3PO, a PFKFB3 inhibitor, reduced lactate level and sensitized A2780CP cells to cisplatin treatment, along with the modulation of inhibitors of apoptosis proteins (c-IAP1, c-IAP2 and survivin) and an immune modulator CD70. Blockade of PFKFB3 by siRNA approach in the CSC-enriched subset led to decreases in glycolysis and CSC properties, and activation of the NF-κB cascade. PFK158, another potent inhibitor of PFKFB3, impaired the stemness of ALDH+CD44+ cells in vitro and in vivo, whereas ectopic expression of PFKFB3 had the opposite results. Overall, PFKFB3 was found to mediate metabolic reprogramming, chemoresistance, metastasis and stemness in ovarian cancer, possibly via the modulation of inhibitors of apoptosis proteins and the NF-κB signaling pathway; thus, suggesting that PFKFB3 may be a potential therapeutic target for ovarian cancer.

TKTL1 participated in malignant progression of cervical cancer cells via regulating AKT signal mediated PFKFB3 and thus regulating glycolysis

BACKGROUND

Cervical cancer (CC) is the second most common cancer among women with high morbidity and mortality. TKTL1 is a key protein in glucose metabolism in cancer cells and controls the pentose phosphate pathway (PPP). In this paper, we aim to explore whether TKTL1 can participate in the malignant process of CC cells through glucose metabolism.

METHODS

The expression and activity of TKTL1 in CC cell lines were detected by RT-qPCR and Western blot. Cell transfection was conducted to interfere the expression of TKTL1 in SiHa cells, with efficiency detected by RT-qPCR and Western blot. Cell proliferation was then measured by CCK-8 kits. Wound Healing and Transwell experiments were performed to respectively detect the levels of cell migration and invasion, and western blot was used to detect the expressions of migration-related proteins. Tunel and Western blot were used to detect the apoptosis and apoptosis-related proteins. Glucose uptake, lactate production, and ATP production were measured by corresponding commercial kits. Next, the expression of p-Akt, AKT, p-MTOR, mTOR, HK2 and PFKFB3 was detected by Western blot. The mechanism was further investigated by interfering the expression of HK2 and PFKFB3 and adding AKT agonist SC79. At the animal level, the tumor bearing mouse model of CC was constructed, and the weight, volume and pathological morphology of the tumor tissue were detected to verify the cell experiment.

RESULTS

TKTL1 expression was increased in CC cells. Interference of TKTL1 expression can inhibit TKTL1 enzyme activity, proliferation, invasion and migration of CC cells, and simultaneously suppress the generation of glycolysis. In addition, the results showed that TKTL1 activated PFKFB3 through AKT rather than HK2 signaling and is involved in glycolysis, cell invasion, migration, and apoptosis of CC cells. In animal level, inhibition of TKTL1 also contributed to decreased tumor volume of CC tumor bearing mice and improved histopathological status.

CONCLUSION

TKTL1 participated in malignant progression of CC cells via regulating AKT signal-mediated HK2 and PFKFB3 and thus regulating glucose metabolism.

Identification of a novel glycolysis-related signature to predict the prognosis of patients with breast cancer

Background

Breast cancer (BC) has a high incidence and mortality rate in females. Its conventional clinical characteristics are far from accurate for the prediction of individual outcomes. Therefore, we aimed to develop a novel signature to predict the survival of patients with BC.

Methods

We analyzed the data of a training cohort from the Cancer Genome Atlas (TCGA) database and a validation cohort from the Gene Expression Omnibus (GEO) database. After the applications of Gene Set Enrichment Analysis (GSEA) and Cox regression analyses, a glycolysis-related signature for predicting the survival of patients with BC was developed; the signature contained AK3, CACNA1H, IL13RA1, NUP43, PGK1, and SDC1. Furthermore, on the basis of expression levels of the six-gene signature, we constructed a risk score formula to classify the patients into high- and low-risk groups. The receiver operating characteristic (ROC) curve and the Kaplan-Meier curve were used to assess the predicted capacity of the model. Later, a nomogram was developed to predict the outcomes of patients with risk score and clinical features over a period of 1, 3, and 5 years. We further used Human Protein Atlas (HPA) database to validate the expressions of the six biomarkers in tumor and sample tissues, which were taken as control.

Results

We constructed a six-gene signature to predict the outcomes of patients with BC. The patients in the high-risk group showed poor prognosis than those in the low-risk group. The area under the curve (AUC) values were 0.719 and 0.702, showing that the prediction performance of the signature is acceptable. Additionally, Cox regression analysis revealed that these biomarkers could independently predict the prognosis of BC patients with BC without being affected by clinical factors. The expression levels of all six biomarkers in BC tissues were higher than that in normal tissues; however, AK3 was an exception.

Conclusion

We developed a six-gene signature to predict the prognosis of patients with BC. Our signature has been proved to have the ability to make an accurate prediction and might be useful in expanding the hypothesis in clinical research.

Salmonella enterica Serovar Typhi Induces Host Metabolic Reprogramming to Increase Glucose Availability for Intracellular Replication

Salmonella enterica serovar Typhi (S. Typhi) is a human-limited intracellular pathogen and the cause of typhoid fever, a severe systemic disease. Pathogen–host interaction at the metabolic level affects the pathogenicity of intracellular pathogens, but it remains unclear how S. Typhi infection influences host metabolism for its own benefit. Herein, using metabolomics and transcriptomics analyses, combined with in vitro and in vivo infection assays, we investigated metabolic responses in human macrophages during S. Typhi infection, and the impact of these responses on S. Typhi intracellular replication and systemic pathogenicity. We observed increased glucose content, higher rates of glucose uptake and glycolysis, and decreased oxidative phosphorylation in S. Typhi-infected human primary macrophages. Replication in human macrophages and the bacterial burden in systemic organs of humanized mice were reduced by either the inhibition of host glucose uptake or a mutation of the bacterial glucose uptake system, indicating that S. Typhi utilizes host-derived glucose to enhance intracellular replication and virulence. Thus, S. Typhi promotes its pathogenicity by inducing metabolic changes in host macrophages and utilizing the glucose that subsequently accumulates as a nutrient for intracellular replication. Our findings provide the first metabolic signature of S. Typhi-infected host cells and identifies a new strategy utilized by S. Typhi for intracellular replication.

Glucose Metabolism and Glucose Transporters in Breast Cancer

Breast cancer is the most common malignancy in women worldwide and is associated with high mortality rates despite the continuously advancing treatment strategies. Glucose is essential for cancer cell metabolism owing to the Warburg effect. During the process of glucose metabolism, various glycolytic metabolites, such as serine and glycine metabolites, are produced and other metabolic pathways, such as the pentose phosphate pathway (PPP), are associated with the process. Glucose is transported into the cell by glucose transporters, such as GLUT. Breast cancer shows high expressions of glucose metabolism-related enzymes and GLUT, which are also related to breast cancer prognosis. Triple negative breast cancer (TNBC), which is a high-grade breast cancer, is especially dependent on glucose metabolism. Breast cancer also harbors various stromal cells such as cancer-associated fibroblasts and immune cells as tumor microenvironment, and there exists a metabolic interaction between these stromal cells and breast cancer cells as explained by the reverse Warburg effect. Breast cancer is heterogeneous, and, consequently, its metabolic status is also diverse, which is especially affected by the molecular subtype, progression stage, and metastatic site. In this review, we will focus on glucose metabolism and glucose transporters in breast cancer, and we will additionally discuss their potential applications as cancer imaging tracers and treatment targets.

Inhibition of Glycolysis Suppresses Cell Proliferation and Tumor Progression In Vivo: Perspectives for Chronotherapy

A high rate of glycolysis is considered a hallmark of tumor progression and is caused by overexpression of the enzyme 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3). Therefore, we analyzed the possibility of inhibiting tumor and endothelial cell metabolism through the inhibition of PFKFB3 by a small molecule, (E)-1-(pyridin-4-yl)-3-(quinolin-2-yl)prop-2-en-1-one (PFK15), as a promising therapy. The effects of PFK15 on cell proliferation and apoptosis were analyzed on human umbilical vein endothelial cells (HUVEC) and the human colorectal adenocarcinoma cell line DLD1 through cytotoxicity and proliferation assays, flow cytometry, and western blotting. The results showed that PFK15 inhibited the proliferation of both cell types and induced apoptosis with decreasing the Bcl-2/Bax ratio. On the basis of the results obtained from in vitro experiments, we performed a study on immunodeficient mice implanted with DLD1 cells. We found a reduced tumor mass after morning PFK15 treatment but not after evening treatment, suggesting circadian control of underlying processes. The reduction in tumor size was related to decreased expression of Ki-67, a marker of cell proliferation. We conclude that inhibition of glycolysis can represent a promising therapeutic strategy for cancer treatment and its efficiency is circadian dependent.

Positive regulation of PFKFB3 by PIM2 promotes glycolysis and paclitaxel resistance in breast cancer

BACKGROUND

Breast cancer (BC) is one of the most common female malignancies in the world. Chemotherapeutic resistance is the major cause of BC therapy failure, leading to tumor recurrence and metastasis. Studies have illustrated the close relationship between glycolysis and BC progression and drug resistance. The key glycolysis regulator, PFKFB3 makes a difference during BC progression and drug resistance. However, the mechanism remains to be unknown.

METHODS

Mass spectrometry analyses were used to found that PIM2 was a potential new binding protein of PFKFB3. Co-immunoprecipitated and western blot were used to verify the interaction between PIM2 and PFKFB3 in BC and the molecular mechanism by which PIM2 phosphorylates PFKFB3 in regulating the protein function. PFKFB3 mutant forms were used to demonstrate the need for PFKFB3 in BC drug resistance.

RESULTS

We identified that PIM2 is a new binding protein of PFKFB3. We used biochemical methods to determine that PIM2 can directly bind and change the phosphorylation of PFKFB3 at Ser478 to enhance PFKFB3 protein stability through the ubiquitin-proteasome pathway. Importantly, phosphorylation of PFKFB3 at Ser478 promoted glycolysis, BC cell growth, and paclitaxel resistance together with PIM2 in vitro and in vivo.

CONCLUSION

Our study demonstrates that PIM2 mediates PFKFB3 phosphorylation thus regulates glycolysis and paclitaxel resistance to promote tumor progression in BC and provides preclinical evidence for targeting PFKFB3 as a new strategy in BC treatment to battle paclitaxel resistance.

Effects of the Novel PFKFB3 Inhibitor KAN0438757 on Colorectal Cancer Cells and Its Systemic Toxicity Evaluation In Vivo

BACKGROUND

Despite substantial progress made in the last decades in colorectal cancer (CRC) research, new treatment approaches are still needed to improve patients' long-term survival. To date, the promising strategy to target tumor angiogenesis metabolically together with a sensitization of CRC to chemo- and/or radiotherapy by PFKFB3 (6-phosphofructo-2-kinase/fructose-2,6-biphosphatase-3) inhibition has never been tested. Therefore, initial evaluation and validation of newly developed compounds such as KAN0438757 and their effects on CRC cells are crucial steps preceding to in vivo preclinical studies, which in turn may consolidate new therapeutic targets.

MATERIALS AND METHODS

The efficiency of KAN0438757 to block PFKFB3 expression and translation in human CRC cells was evaluated by immunoblotting and real-time PCR. Functional in vitro assays assessed the effects of KAN0438757 on cell viability, proliferation, survival, adhesion, migration and invasion. Additionally, we evaluated the effects of KAN0438757 on matched patient-derived normal and tumor organoids and its systemic toxicity in vivo in C57BL6/N mice.

RESULTS

High PFKFB3 expression is correlated with a worse survival in CRC patients. KAN0438757 reduces PFKFB3 protein expression without affecting its transcriptional regulation. Additionally, a concentration-dependent anti-proliferative effect was observed. The migration and invasion capacity of cancer cells were significantly reduced, independent of the anti-proliferative effect. When treating colonic patient-derived organoids with KAN0438757 an impressive effect on tumor organoids growth was apparent, surprisingly sparing normal colonic organoids. No high-grade toxicity was observed in vivo.

CONCLUSION

The PFKFB3 inhibitor KAN0438757 significantly reduced CRC cell migration, invasion and survival. Moreover, on patient-derived cancer organoids KAN0438757 showed significant effects on growth, without being overly toxic in normal colon organoids and healthy mice. Our findings strongly encourage further translational studies to evaluate KAN0438757 in CRC therapy.

Role of PFKFB3 and PFKFB4 in Cancer: Genetic Basis, Impact on Disease Development/Progression, and Potential as Therapeutic Targets

Glycolysis is a crucial metabolic process in rapidly proliferating cells such as cancer cells. Phosphofructokinase-1 (PFK-1) is a key rate-limiting enzyme of glycolysis. Its efficiency is allosterically regulated by numerous substances occurring in the cytoplasm. However, the most potent regulator of PFK-1 is fructose-2,6-bisphosphate (F-2,6-BP), the level of which is strongly associated with 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase activity (PFK-2/FBPase-2, PFKFB). PFK-2/FBPase-2 is a bifunctional enzyme responsible for F-2,6-BP synthesis and degradation. Four isozymes of PFKFB (PFKFB1, PFKFB2, PFKFB3, and PFKFB4) have been identified. Alterations in the levels of all PFK-2/FBPase-2 isozymes have been reported in different diseases. However, most recent studies have focused on an increased expression of PFKFB3 and PFKFB4 in cancer tissues and their role in carcinogenesis. In this review, we summarize our current knowledge on all PFKFB genes and protein structures, and emphasize important differences between the isoenzymes, which likely affect their kinase/phosphatase activities. The main focus is on the latest reports in this field of cancer research, and in particular the impact of PFKFB3 and PFKFB4 on tumor progression, metastasis, angiogenesis, and autophagy. We also present the most recent achievements in the development of new drugs targeting these isozymes. Finally, we discuss potential combination therapies using PFKFB3 inhibitors, which may represent important future cancer treatment options.

Sex Differences in the Pro-Angiogenic Response of Human Endothelial Cells: Focus on PFKFB3 and FAK Activation

Female hormones and sex-specific factors are established determinants of endothelial function, yet their relative contribution to human endothelium phenotypes has not been defined. Using human umbilical vein endothelial cells (HUVECs) genotyped by donor's sex, we investigated the influence of sex and estrogenic agents on the main steps of the angiogenic process and on key proteins governing HUVEC metabolism and migratory properties. HUVECs from female donors (fHUVECs) showed increased viability (p < 0.01) and growth rate (p < 0.01) compared with those from males (mHUVECs). Despite higher levels of G-protein coupled estrogen receptor (GPER) in fHUVECs (p < 0.001), treatment with 17β-estradiol (E2) and the selective GPER agonist G1 (both 1-100 nM) did not affect HUVEC viability. Migration and tubularization in vitro under physiological conditions were higher in fHUVECs than in mHUVECs (p < 0.05). E2 treatment (1-100 nM) upregulated the glycolytic activator PFKFB3 with higher potency in fHUVECs than in mHUVECs, despite comparable baseline levels. Moreover, Y576/577 phosphorylation of focal adhesion kinase (FAK) was markedly enhanced in fHUVECs (p < 0.001), despite comparable Src activation levels. While the PI3K inhibitor LY294002 (25 µM) inhibited HUVEC migration (p < 0.05), Akt phosphorylation levels in fHUVECs and mHUVECs were comparable. Finally, digitoxin treatment, which inhibits Y576/577 FAK phosphorylation, abolished sexual dimorphism in HUVEC migration. These findings unravel complementary modulation of HUVEC functional phenotypes and signaling molecules involved in angiogenesis by hormone microenvironment and sex-specific factors, and highlight the need for sex-oriented pharmacological targeting of endothelial function.

The effect of a novel glycolysis-related gene signature on progression, prognosis and immune microenvironment of renal cell carcinoma

Background

Glycolysis is a central metabolic pathway for tumor cells. However, the potential roles of glycolysis-related genes in renal cell carcinoma (RCC) have not been investigated.

Methods

Seven glycolysis-related gene sets were selected from MSigDB and were analyzed through GSEA. Using TCGA database, the glycolysis-related gene signature was constructed. Prognostic analyses were based on the Kaplan–Meier method. The cBioPortal database was employed to perform the mutation analyses. The CIBERSORT algorithm and TIMER database were used to determine the immunological effect of glycolytic gene signature. The expressions in protein level of eight glycolytic risk genes were determined by HPA database. Finally, qPCR, MTT and Transwell invasion assays were conducted to validate the roles of core glycolytic risk genes (CD44, PLOD1 and PLOD2) in RCC.

Results

Four glycolysis-related gene sets were significantly enriched in RCC samples. The glycolytic risk signature was constructed (including CD44, PLOD2, KIF20A, IDUA, PLOD1, HMMR, DEPDC1 and ANKZF1) and identified as an independent RCC prognostic factor (HR = 1.204). Moreover, genetic alterations of glycolytic risk genes were uncommon in RCC (10.5%) and glycolytic risk signature can partially affect immune microenvironment of RCC. Six glycolytic risk genes (except for IDUA and HMMR) were over-expression in A498 and 786-O renal cancer cells through qPCR test. MTT and Transwell assays revealed that silencing of CD44, PLOD1 and PLOD2 suppressed the proliferation and invasion of renal cancer cells.

Conclusions

The glycolysis-related risk signature is closely associated with RCC prognosis, progression and immune microenvironment. CD44, PLOD1 and PLOD2 may serve as RCC oncogenes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-020-07702-7.

Prognostic model of invasive ductal carcinoma of the breast based on differentially expressed glycolysis-related genes

Background

Invasive ductal carcinoma (IDC) is a common pathological type of breast cancer that is characterized by high malignancy and rapid progression. Upregulation of glycolysis is a hallmark of tumor growth, and correlates with the progression of breast cancer. We aimed to establish a model to predict the prognosis of patients with breast IDC based on differentially expressed glycolysis-related genes (DEGRGs).

Methods

Transcriptome data and clinical data of patients with breast IDC were from The Cancer Genome Atlas (TCGA). Glycolysis-related gene sets and pathways were from the Molecular Signatures Database (MSigDB). DEGRGs were identified by comparison of tumor tissues and adjacent normal tissues. Univariate Cox regression and least absolute shrinkage and selection operator (LASSO) regression were used to screen for DEGRGs with prognostic value. A risk-scoring model based on DEGRGs related to prognosis was constructed. Receiver operating characteristic (ROC) analysis and calculation of the area under the curve (AUC) were used to evaluate the performance of the model. The model was verified in different clinical subgroups using an external dataset (GSE131769). A nomogram that included clinical indicators and risk scores was established. Gene function enrichment analysis was performed, and a protein-protein interaction network was developed.

Results

We analyzed data from 772 tumors and 88 adjacent normal tissues from the TCGA database and identified 286 glycolysis-related genes from the MSigDB. There were 185 DEGRGs. Univariate Cox regression and LASSO regression indicated that 13 of these genes were related to prognosis. A risk-scoring model based on these 13 DEGRGs allowed classification of patients as high-risk or low-risk according to median score. The duration of overall survival (OS) was longer in the low-risk group (P < 0.001), and the AUC was 0.755 for 3-year OS and 0.726 for 5-year OS. The results were similar when using the GEO data set for external validation (AUC for 3-year OS: 0.731, AUC for 5-year OS: 0.728). Subgroup analysis showed there were significant differences in OS among high-risk and low-risk patients in different subgroups (T1-2, T3-4, N0, N1-3, M0, TNBC, non-TNBC; all P < 0.01). The C-index was 0.824, and the AUC was 0.842 for 3-year OS and 0.808 for 5-year OS from the nomogram. Functional enrichment analysis demonstrated the DEGRGs were mainly involved in regulating biological functions.

Conclusions

Our prognostic model, based on 13 DEGRGs, had excellent performance in predicting the survival of patients with IDC of the breast. These DEGRGs appear to have important biological functions in the progression of this cancer.

Targeting Glucose Metabolism to Overcome Resistance to Anticancer Chemotherapy in Breast Cancer

Breast cancer (BC) is the most prevalent cancer in women. BC is heterogeneous, with distinct phenotypical and morphological characteristics. These are based on their gene expression profiles, which divide BC into different subtypes, among which the triple-negative breast cancer (TNBC) subtype is the most aggressive one. The growing interest in tumor metabolism emphasizes the role of altered glucose metabolism in driving cancer progression, response to cancer treatment, and its distinct role in therapy resistance. Alterations in glucose metabolism are characterized by increased uptake of glucose, hyperactivated glycolysis, decreased oxidative phosphorylation (OXPHOS) component, and the accumulation of lactate. These deviations are attributed to the upregulation of key glycolytic enzymes and transporters of the glucose metabolic pathway. Key glycolytic enzymes such as hexokinase, lactate dehydrogenase, and enolase are upregulated, thereby conferring resistance towards drugs such as cisplatin, paclitaxel, tamoxifen, and doxorubicin. Besides, drug efflux and detoxification are two energy-dependent mechanisms contributing to resistance. The emergence of resistance to chemotherapy can occur at an early or later stage of the treatment, thus limiting the success and outcome of the therapy. Therefore, understanding the aberrant glucose metabolism in tumors and its link in conferring therapy resistance is essential. Using combinatory treatment with metabolic inhibitors, for example, 2-deoxy-D-glucose (2-DG) and metformin, showed promising results in countering therapy resistance. Newer drug designs such as drugs conjugated to sugars or peptides that utilize the enhanced expression of tumor cell glucose transporters offer selective and efficient drug delivery to cancer cells with less toxicity to healthy cells. Last but not least, naturally occurring compounds of plants defined as phytochemicals manifest a promising approach for the eradication of cancer cells via suppression of essential enzymes or other compartments associated with glycolysis. Their benefits for human health open new opportunities in therapeutic intervention, either alone or in combination with chemotherapeutic drugs. Importantly, phytochemicals as efficacious instruments of anticancer therapy can suppress events leading to chemoresistance of cancer cells. Here, we review the current knowledge of altered glucose metabolism in contributing to resistance to classical anticancer drugs in BC treatment and various ways to target the aberrant metabolism that will serve as a promising strategy for chemosensitizing tumors and overcoming resistance in BC.

Emerging roles and the regulation of aerobic glycolysis in hepatocellular carcinoma

Liver cancer has become the sixth most diagnosed cancer and the fourth leading cause of cancer death worldwide. Hepatocellular carcinoma (HCC) is responsible for up to 75–85% of primary liver cancers, and sorafenib is the first targeted drug for advanced HCC treatment. However, sorafenib resistance is common because of the resultant enhancement of aerobic glycolysis and other molecular mechanisms. Aerobic glycolysis was firstly found in HCC, acts as a hallmark of liver cancer and is responsible for the regulation of proliferation, immune evasion, invasion, metastasis, angiogenesis, and drug resistance in HCC. The three rate-limiting enzymes in the glycolytic pathway, including hexokinase 2 (HK2), phosphofructokinase 1 (PFK1), and pyruvate kinases type M2 (PKM2) play an important role in the regulation of aerobic glycolysis in HCC and can be regulated by many mechanisms, such as the AMPK, PI3K/Akt pathway, HIF-1α, c-Myc and noncoding RNAs. Because of the importance of aerobic glycolysis in the progression of HCC, targeting key factors in its pathway such as the inhibition of HK2, PFK or PKM2, represent potential new therapeutic approaches for the treatment of HCC.

FAM46C inhibits cell proliferation and cell cycle progression and promotes apoptosis through PTEN/AKT signaling pathway and is associated with chemosensitivity in prostate cancer

Family with sequence similarity 46 member C (FAM46C) is a non-canonical poly(A) polymerase that is associated with tumorigenesis. However, its role in prostate cancer development is not fully understood. Herein, we determined expression pattern of FAM46C in prostate cancer and further identified its effect on the tumorigenesis and chemosensitivity. FAM46C expression was decreased in prostate cancer tissues and cell lines compared with corresponding controls. FAM46C expression was significantly associated with the Gleason score, tumor size and overall survival. FAM46C knockdown in 22RV1 and DU145 cells significantly inhibited apoptosis and promoted cell proliferation and cell cycle progression as well as activation of AKT. FAM46C overexpression had an inverse effect in DU145 cells and inhibited tumor growth in vivo. FAM46C inhibited cell proliferation and cell cycle progression and induced apoptosis via the PTEN/AKT signaling pathway. FAM46C promoted PTEN expression through inhibiting PTEN ubiquitination. The prostate cancer cells and patient-derived xenograft (PDX) mice with high-FAM46C-expressing demonstrated an enhanced chemosensitivity to docetaxel. These findings suggest that FAM46C control cell proliferation, cell cycle and apoptosis through PTEN/AKT signaling pathway and is associated with chemosensitivity of prostate cancer. Modulation of their levels may offer a new approach for improving anti-tumor efficacy for chemotherapeutic agents in prostate cancer.

The enhancement of glycolysis regulates pancreatic cancer metastasis

Pancreatic ductal adenocarcinoma is prone to distant metastasis and is expected to become the second leading cause of cancer-related death. In an extremely nutrient-deficient and hypoxic environment resulting from uncontrolled growth, vascular disturbances and desmoplastic reactions, pancreatic cancer cells utilize "metabolic reprogramming" to satisfy their energy demand and support malignant behaviors such as metastasis. Notably, pancreatic cancer cells show extensive enhancement of glycolysis, including glycolytic enzyme overexpression and increased lactate production, and this is caused by mitochondrial dysfunction, cancer driver genes, specific transcription factors, a hypoxic tumor microenvironment and stromal cells, such as cancer-associated fibroblasts and tumor-associated macrophages. The metabolic switch from oxidative phosphorylation to glycolysis in pancreatic cancer cells regulates the invasion-metastasis cascade by promoting epithelial-mesenchymal transition, tumor angiogenesis and the metastatic colonization of distant organs. In addition to aerobic glycolysis, oxidative phosphorylation also plays a critical role in pancreatic cancer metastasis in ways that remain unclear. In this review, we expound on the intracellular and extracellular causes of the enhancement of glycolysis in pancreatic cancer and the strong association between glycolysis and cancer metastasis, which we expect will yield new therapeutic approaches targeting cancer metabolism.

Endothelial Cells (ECs) Metabolism: A Valuable Piece to Disentangle Cancer Biology

Effective therapies to fight cancer should not be focused specifically on cancer cells, but it should consider the various components of the TME. Non-cancerous cells cooperate with cancer cells by sharing signaling and organic molecules, accounting for cancer progression. Most of the anti-angiogenic therapy clinically approved for the treatment of human diseases relies on targeting vascular endothelial growth factor (VEGF) signaling pathway. Unexpectedly and unfortunately, the results of anti-angiogenic therapies in the treatment of human diseases are not so effective, showing an insufficient efficacy and resistance.This chapter will give some insights on showing that targeting endothelial cell metabolism is a missing piece to revolutionize cancer therapy. Only recently endothelial cell (EC) metabolism has been granted as an important inducer of angiogenesis. Metabolic studies in EC demonstrated that targeting EC metabolism can be an alternative to overcome the failure of anti-angiogenic therapies. Hence, it is urgent to increase the knowledge on how ECs alter their metabolism during human diseases, in order to open new therapeutic perspectives in the treatment of pathophysiological angiogenesis, as in cancer.

The influence of PFK-II overexpression on neuroblastoma patients' survival may be dependent on the particular isoenzyme expressed, PFKFB3 or PFKFB4

Background/Aim

During cancer progression metabolic reprogramming is observed in parallel to the alternation in transcriptional profiles of malignant cells. Recent studies suggest that metabolic isoenzymes of phosphofructokinase II (PFK-II) – PFKFB3 and PFKFB4, often induced in hypoxic environment, significantly contribute to enhancement of glucose metabolism and in consequence cancer progression.

Materials and methods

Using the publicly available data deposited in the R2 data base we performed a Kaplan–Meyer analysis for cancer patients divided into groups with high and low expression levels of PFKFB3/4, determined based on the median.

Results

Our data showed that high PFKFB3/4 expression significantly correlates with shorter overall survival in several cancers. Moreover, we found that neuroblastoma patients with poor overall survival and evidence free survival are characterized by high PFKFB3 and at the same time low PFKFB4 expression, whereas patients with high PFKFB4 expressions are characterized by significantly better overall survival/evidence free survival rates.

Conclusion

Our analysis clearly indicates that expression of PFKFB3/4 isoenzymes may have a key prognostic value for several cancers. What’s more, it seems that in neuroblastoma the prognostic value of PFK-II may be dependent on the relation between PFKFB3 and PFKFB4 isoenzyme expression, indicating that further studies analyzing the role of both cancer specific PFK-II isoenzymes are highly desired.

Emerging roles of aerobic glycolysis in breast cancer

Altered aerobic glycolysis is a well-recognized characteristic of cancer cell energy metabolism, known as the Warburg effect. Even in the presence of abundant oxygen, a majority of tumor cells produce substantial amounts of energy through a high glycolytic metabolism, and breast cancer (BC) is no exception. Breast cancer continues to be the second leading cause of cancer-associated mortality in women worldwide. However, the precise role of aerobic glycolysis in the development of BC remains elusive. Therefore, the present review attempts to address the implication of key enzymes of the aerobic glycolytic pathway including hexokinase (HK), phosphofructokinase (PFK) and pyruvate kinase (PK), glucose transporters (GLUTs), together with related signaling pathways including protein kinase B(PI3K/AKT), mammalian target of rapamycin (mTOR) and adenosine monophosphate-activated protein kinase (AMPK) and transcription factors (c-myc, p53 and HIF-1) in the research of BC. Thus, the review of aerobic glycolysis in BC may evoke novel ideas for the BC treatment.

A Comprehensive Pan-Cancer Molecular Study of Gynecologic and Breast Cancers

We analyzed molecular data on 2,579 tumors from The Cancer Genome Atlas (TCGA) of four gynecological types plus breast. Our aims were to identify shared and unique molecular features, clinically significant subtypes, and potential therapeutic targets. We found 61 somatic copy-number alterations (SCNAs) and 46 significantly mutated genes (SMGs). Eleven SCNAs and 11 SMGs had not been identified in previous TCGA studies of the individual tumor types. We found functionally significant estrogen receptor-regulated long non-coding RNAs (lncRNAs) and gene/lncRNA interaction networks. Pathway analysis identified subtypes with high leukocyte infiltration, raising potential implications for immunotherapy. Using 16 key molecular features, we identified five prognostic subtypes and developed a decision tree that classified patients into the subtypes based on just six features that are assessable in clinical laboratories.