AKT2 phosphorylation of hexokinase 2 at T473 promotes tumorigenesis and metastasis in colon cancer cells via NF-κB, HIF1α, MMP2, and MMP9 upregulation

Fanconi Anemia Complementary Group A (FANCA) Facilitates the Occurrence and Progression of Liver Hepatocellular Carcinoma

BACKGROUND

Liver hepatocellular carcinoma (LIHC) is a serious liver disease worldwide, and its pathogenesis is complicated.

AIMS

This study investigated the potential role of FANCA in the advancement and prognosis of LIHC.

METHODS

Public databases, quantitative reverse transcription polymerase chain reaction (qRT-PCR), western blot (WB) and immunohistochemistry (IHC) were employed to measure FANCA expression between tumor and normal samples. The relationship between FANCA expression and prognosis of LIHC patients were examined. Functional enrichment of FANCA-related genes was performed. Furthermore, univariate and multivariate analyses were conducted to determine the independent prognosis value of FANCA in LIHC. Finally, influence of FANCA knockout on the proliferation, migration, and invasion of HepG2 cell was validated with cloning formation, CCK8, and Transwell assays.

RESULTS

Expression analysis presented that FANCA had high expression level in LIHC tissues and cells. Receiver operating characteristic (ROC) curve analysis showed that FANCA was of great diagnosis value in LIHC. Clinicopathological analysis revealed that FANCA was significantly greater expressed in the advanced stage than in the early stage of LIHC. Univariate, multivariate, and Kaplan-Meier survival analysis confirmed that high expression of FANCA was strongly associated with poor survival of LIHC patients. In addition, high level of FANCA in LIHC showed a negative association with immunoinfiltrated B cells, T cells, and stromal scores. Moreover, Knockout of FANCA significantly inhibited HepG2 cell proliferative activity, migration, and invasion ability.

CONCLUSIONS

Our data revealed that high level of FANCA was closely associated with LIHC malignant progression, suggesting its potential utility as a diagnostic, predictive indicator, and therapeutic target.

All Three AKT Isoforms Can Upregulate Oxygen Metabolism and Lactate Production in Human Hepatocellular Carcinoma Cell Lines

Hepatocellular carcinoma (HCC), the main pathological type of liver cancer, is related to risk factors such as viral hepatitis, alcohol intake, and non-alcoholic fatty liver disease (NAFLD). The constitutive activation of the PI3K/AKT signaling pathway is common in HCC and has essential involvement in tumor progression. The serine/threonine kinase AKT has several downstream substrates, which have been implicated in the regulation of cellular metabolism. However, the contribution of each of the three AKT isoforms, i.e., AKT1, AKT2 and AKT3, to HCC metabolism has not been comprehensively investigated. In this study, we analyzed the functional role of AKT1, AKT2 and AKT3 in HCC metabolism. The overexpression of activated AKT1, AKT2 and AKT3 isoforms in the human HCC cell lines Hep3B and Huh7 resulted in higher oxygen consumption rate (OCR), ATP production, maximal respiration and spare respiratory capacity in comparison to vector-transduced cells. Vice versa, lentiviral vector-mediated knockdowns of each AKT isoform reduced OCR in both cell lines. Reduced OCR rates observed in the three AKT isoform knockdowns were associated with reduced extracellular acidification rates (ECAR) and reduced lactate production in both analyzed cell lines. Mechanistically, the downregulation of OCR by AKT isoform knockdowns correlated with an increased phosphorylation of the pyruvate dehydrogenase on Ser232, which negatively regulates the activity of this crucial gatekeeper of mitochondrial respiration. In summary, our data indicate that each of the three AKT isoforms is able to upregulate OCR, ECAR and lactate production independently of each other in human HCC cells through the regulation of the pyruvate dehydrogenase.

Phytochemicals Target Multiple Metabolic Pathways in Cancer

Cancer metabolic reprogramming is a complex process that provides malignant cells with selective advantages to grow and propagate in the hostile environment created by the immune surveillance of the human organism. This process underpins cancer proliferation, invasion, antioxidant defense, and resistance to anticancer immunity and therapeutics. Perhaps not surprisingly, metabolic rewiring is considered to be one of the "Hallmarks of cancer". Notably, this process often comprises various complementary and overlapping pathways. Today, it is well known that highly selective inhibition of only one of the pathways in a tumor cell often leads to a limited response and, subsequently, to the emergence of resistance. Therefore, to increase the overall effectiveness of antitumor drugs, it is advisable to use multitarget agents that can simultaneously suppress several key processes in the tumor cell. This review is focused on a group of plant-derived natural compounds that simultaneously target different pathways of cancer-associated metabolism, including aerobic glycolysis, respiration, glutaminolysis, one-carbon metabolism, de novo lipogenesis, and β-oxidation of fatty acids. We discuss only those compounds that display inhibitory activity against several metabolic pathways as well as a number of important signaling pathways in cancer. Information about their pharmacokinetics in animals and humans is also presented. Taken together, a number of known plant-derived compounds may target multiple metabolic and signaling pathways in various malignancies, something that bears great potential for the further improvement of antineoplastic therapy.

Identification of lactate regulation pattern on tumor immune infiltration, therapy response, and DNA methylation in diffuse large B-cell lymphoma

Background

Lactate, produced through glycolytic metabolism in the tumor microenvironment (TME), is implicated in tumorigenesis and progression in diverse cancers. However, the impact of lactate on the remodeling of the TME in diffuse large B-cell lymphoma (DLBCL) and its implications for therapy options remain unclear.

Method

A lactate-related (LAR) scoring model was constructed in DLBCL patients using bioinformatic methods. CIBERSORT, XCELL, and ssGSEA algorithms were used to determine the correlation between LAR score and immune cell infiltration. Tumor Immune Dysfunction and Exclusion (TIDE), rituximab, cyclophosphamide, adriamycin, vincristine, and prednisone (R-CHOP) cohorts, and Genomics of Drug Sensitivity in Cancer (GDSC) were utilized to predict the therapeutic response of DLBCL patients. The impact of the hub gene STAT4 on tumor biological behavior and DNA methylation was experimentally validated or accessed by the TSIDE database.

Results

The LAR scoring model was developed based on 20 prognosis-related lactate genes, which enabled the division of DLBCL patients into high- and low-risk groups based on the median LAR score. Patients with high-risk DLBCL exhibited significantly worse survival outcomes in both the training cohorts (GSE181063) and the validation cohorts (GSE10846, GSE32918, and GSE69053), as indicated by statistically significant differences (all P<0.05) and area under the curve (AUC) values exceeding 0.6. Immune analyses revealed that low-risk DLBCL patients had higher levels of immune cell infiltration and antitumor immune activation compared to high-risk DLBCL patients. Furthermore, DLBCL patients with high LAR scores were associated with a lower TIDE value and poor therapeutic efficacy of the R-CHOP regimen. GDSC analysis identified 18 drugs that exhibited significant response sensitivity in low-risk DLBCL patients. Moreover, in vitro experiments demonstrated that overexpression of the lactate key gene STAT4 could suppress proliferation and migration, induce cell cycle arrest, and promote cell apoptosis in DLBCL cells. Transcriptional expression and methylation of the STAT4 gene were found to be associated with immunomodulators and chemokines.

Conclusion

The lactate-based gene signature effectively predicts the prognosis and regulates TME in DLBCL. Our study underscores the role of lactate gene, STAT4, as an important tumor suppressor in DLBCL. Modulating STAT4 could be a promising strategy for DLBCL in clinical practice.

Gastric cancer mesenchymal stem cells via the CXCR2/HK2/PD-L1 pathway mediate immunosuppression

BACKGROUND

Anti-PD-1 immunotherapy has emerged as an important therapeutic modality in advanced gastric cancer (GC). However, drug resistance frequently develops, limiting its effectiveness.

METHODS

The role of gastric cancer mesenchymal stem cells (GCMSCs) in anti-PD-1 resistance was evaluated in vivo in NPGCD34+ or NCGPBMC xenograft mouse model. In addition, we investigated CD8+T cell infiltration and effector function by spectral cytometry and IHC. The effects of GCMSCs conditional medium (GCMSC-CM) on GC cell lines were characterized at the level of the proteome, secretome using western blot, and ELISA assays.

RESULTS

We reported that GCMSCs mediated tolerance mechanisms contribute to tumor immunotherapy tolerance. GCMSC-CM attenuated the antitumor activity of PD-1 antibody and inhibited immune response in humanized mouse model. In GC cells under serum deprivation and hypoxia, GCMSC-CM promoted GC cells proliferation via upregulating PD-L1 expression. Mechanistically, GCMSC-derived IL-8 and AKT-mediated phosphorylation facilitated HK2 nuclear localization. Phosphorylated-HK2 promoted PD-L1 transcription by binding to HIF-1α. What is more, GCMSC-CM also induced lactate overproduction in GC cells in vitro and xenograft tumors in vivo, leading to impaired function of CD8+ T cells. Furthermore, CXCR1/2 receptor depletion, CXCR2 receptor antagonist AZD5069 and IL-8 neutralizing antibody application also significantly reversed GCMSCs mediated immunosuppression, restoring the antitumor capacity of PD-1 antibody.

CONCLUSIONS

Our findings reveal that blocking GCMSCs-derived IL-8/CXCR2 pathway decreasing PD-L1 expression and lactate production, improving antitumor efficacy of anti-PD-1 immunotherapy, may be of value for the treatment of advanced gastric carcinoma.

Protein posttranslational modifications in health and diseases: Functions, regulatory mechanisms, and therapeutic implications

Protein posttranslational modifications (PTMs) refer to the breaking or generation of covalent bonds on the backbones or amino acid side chains of proteins and expand the diversity of proteins, which provides the basis for the emergence of organismal complexity. To date, more than 650 types of protein modifications, such as the most well-known phosphorylation, ubiquitination, glycosylation, methylation, SUMOylation, short-chain and long-chain acylation modifications, redox modifications, and irreversible modifications, have been described, and the inventory is still increasing. By changing the protein conformation, localization, activity, stability, charges, and interactions with other biomolecules, PTMs ultimately alter the phenotypes and biological processes of cells. The homeostasis of protein modifications is important to human health. Abnormal PTMs may cause changes in protein properties and loss of protein functions, which are closely related to the occurrence and development of various diseases. In this review, we systematically introduce the characteristics, regulatory mechanisms, and functions of various PTMs in health and diseases. In addition, the therapeutic prospects in various diseases by targeting PTMs and associated regulatory enzymes are also summarized. This work will deepen the understanding of protein modifications in health and diseases and promote the discovery of diagnostic and prognostic markers and drug targets for diseases.

Nanotechnology-empowered lung cancer therapy: From EMT role in cancer metastasis to application of nanoengineered structures for modulating growth and metastasis

Lung cancer is one of the leading causes of death in both males and females, and it is the first causes of cancer-related deaths. Chemotherapy, surgery and radiotherapy are conventional treatment of lung cancer and recently, immunotherapy has been also appeared as another therapeutic strategy for lung tumor. However, since previous treatments have not been successful in cancer therapy and improving prognosis and survival rate of lung tumor patients, new studies have focused on gene therapy and targeting underlying molecular pathways involved in lung cancer progression. Nanoparticles have been emerged in treatment of lung cancer that can mediate targeted delivery of drugs and genes. Nanoparticles protect drugs and genes against unexpected interactions in blood circulation and improve their circulation time. Nanoparticles can induce phototherapy in lung cancer ablation and mediating cell death. Nanoparticles can induce photothermal and photodynamic therapy in lung cancer. The nanostructures can impair metastasis of lung cancer and suppress EMT in improving drug sensitivity. Metastasis is one of the drawbacks observed in lung cancer that promotes migration of tumor cells and allows them to establish new colony in secondary site. EMT can occur in lung cancer and promotes tumor invasion. EMT is not certain to lung cancer and it can be observed in other human cancers, but since lung cancer has highest incidence rate, understanding EMT function in lung cancer is beneficial in improving prognosis of patients. EMT induction in lung cancer promotes tumor invasion and it can also lead to drug resistance and radio-resistance. Moreover, non-coding RNAs and pharmacological compounds can regulate EMT in lung cancer and EMT-TFs such as Twist and Slug are important modulators of lung cancer invasion that are discussed in current review.

Regulation of tumor metabolism by post translational modifications on metabolic enzymes

Metabolic reprogramming is a hallmark of cancer development, progression, and metastasis. Several metabolic pathways such as glycolysis, tricarboxylic acid (TCA) cycle, lipid metabolism, and glutamine catabolism are frequently altered to support cancer growth. Importantly, the activity of the rate-limiting metabolic enzymes in these pathways are specifically modulated in cancer cells. This is achieved by transcriptional, translational, and post translational regulations that enhance the expression, activity, stability, and substrate sensitivity of the rate-limiting enzymes. These mechanisms allow the enzymes to retain increased activity supporting the metabolic needs of rapidly growing tumors, sustain their survival in the hostile tumor microenvironments and in the metastatic lesions. In this review, we primarily focused on the post translational modifications of the rate-limiting enzymes in the glucose and glutamine metabolism, TCA cycle, and fatty acid metabolism promoting tumor progression and metastasis.

miR-126 regulates the proliferation, migration, invasion, and apoptosis of non-small lung cancer cells via AKT2/HK2 axis

This study tended to clarify the role of miR-126 in non-small cell lung cancer (NSCLC) cell biological behaviors in vitro, containing cell proliferation, migration, invasion, and apoptosis. miRNA expression microarray related to NSCLC was accessed from gene expression omnibus (GEO) database and subjected to differential analysis using the "limma" package. Real-time quantitative PCR was conducted to assess the expression of miR-126 in NSCLC cell lines. wIn vitro experiments including 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), wound healing assay, Transwell, and flow cytometry assay were used for evaluating the effect of miR-126 on cell proliferation, migration, invasion, and apoptosis. Additionally, target mRNA for miR-126 was predicted and further validated by bioinformatics analysis and dual-luciferase reporter assay, respectively. It suggested that miR-126 was significantly down-regulated in NSCLS based on the expression microarray, and similar expression trend was exhibited in cancer cell lines. In the meantime, overexpression of miR-126 was found to result in inhibition of cell proliferation, migration, and invasion while promotion of cell apoptosis, with reductions in protein expression of AKT2 and phosphorylated HK2 (p-HK2) as well. AKT2, identified to be a direct target of miR-126 in NSCLC as judged by dual-luciferase reporter assay. Additionally, overexpression of AKT2 was observed to have the ability of elevating p-HK2 protein expression and reversing the effect of miR-126 on NSCLC cell proliferation, migration, and invasion. Given the above findings, we can see that miR-126 exerts its role in NSCLC cell proliferation, migration, invasion, and apoptosis with the aid of AKT2/HK2 axis.

Hexokinases in cancer and other pathologies

Glucose metabolism is indispensable for cell growth and survival. Hexokinases play pivotal roles in glucose metabolism through canonical functions of hexokinases as well as in immune response, cell stemness, autophagy, and other cellular activities through noncanonical functions. The aberrant regulation of hexokinases contributes to the development and progression of pathologies, including cancer and immune diseases.

Hexokinase 2 promoted cell motility and proliferation by activating Akt1/p-Akt1 in human ovarian cancer cells

Background

Recently, increasing evidence has indicated that elevation of Hexokinase 2 (HK2) plays an important role in several cancers on regulating cell motility and growth. However, its role on regulating cell EMT in human ovarian cancer still less to known.

Methods

The transwell and wound-healing assay were used to detect the effective of HK2 on regulating motility of ovarian cancer cells. Real Time PCR and Western Blotting were used to explore the changing of EMT-related proteins in HK2-modified cells. The clonogenic formation, cell growth curves and MTT assays were used to evaluate the effective of HK2 on regulating cell proliferation in HK2-modified cells. The flow cytometry was used to detect the differences in the distribution of cells in the cell cycle between the HK2-modified cells and their control cells. The correlation of HK2 and Akt1/p-Akt1 was explored by using Western Blotting, Akt1 inhibitor (MK2206) and transient transfection of an Akt1 recombinant plasmid. The potential correlation between HK2 and EMT-related proteins in human ovarian cancer tissues and OV (ovarian serous cystadenocarcinoma) was confirmed by using Pearson correlation analysis and TIMER 2.0.

Results

In ovarian cancer cells, overexpressing of HK2 enhanced cell motility by inducing of EMT-related proteins, such as CDH2, fibronectin, MMP9, ZEB1, ZEB2 and vimentin. Moreover, overexpressing of HK2 promoted cell growth by reducing p21 and p27 expression in ovarian cancer cells. Further studies demonstrated that this promotion of cell motility and growth by HK2 was probably a result of it activating of Akt1 (p-Akt1) in ovarian cancer cells. Additionally, the positive correlation between HK2 and p-Akt1, fibronectin, MMP9 expression in human ovarian cancer samples was verified by using Pearson correlation analysis. The positive correlation between HK2 and CDH2, fibronectin, MMP9, ZEB1, ZEB2 and vimentin in OV (ovarian serous cystadenocarcinoma) was confirmed by using TIMER 2.0.

Conclusion

This study demonstrated that HK2 could induce EMT-related proteins and reduce cell cycle inhibitor by activating Akt1 in human ovarian cancer cells, subsequently enhancing cell motility and growth, suggesting that HK2 participate in the malignant process of ovarian cancer by interacting with Akt1.

ASIC1α up-regulates MMP-2/9 expression to enhance mobility and proliferation of liver cancer cells via the PI3K/AKT/mTOR pathway

A major challenge in the treatment of liver cancer is that a large proportion of patients fail to achieve long-term disease control, with death from liver cancer cell migration and invasion. Acid-sensitive ion channel 1α (ASIC1α) is involved in the migration, invasion, and proliferation of liver cancer cells. Therefore, we explored the mechanism of ASIC1α-mediated liver cancer cell migration and invasion. We determined the levels of ASIC1α by western blotting and immunofluorescence in HepG2 and SK-Hep1 cells cultured in various acidic conditions. In addition, wound healing assay, transwell invasion assay, and MTT assay were conducted to assess the migration, invasion, and proliferation abilities of liver cancer cells. Western blotting was conducted to determine the levels of MMP2, MMP9, ASIC1α, p-PI3Kp85, t-PI3Kp85, p-AKT(Ser473), t-AKT, p-mTOR (Ser2448), t-mTOR. We first found that the levels of ASIC1α in the HepG2 and SK-Hep1 cells in acidic conditions (pH 6.5) were significantly increased. Inhibition and knockdown of ASIC1α down-regulated MMP-2/9 expression and inhibited the migration, invasion, and proliferation of HepG2 and SK-Hep1 cells; overexpression of ASIC1α had the opposite effect. We further demonstrated that ASIC1α up-regulates MMP-2/9 via activation of the PI3K/AKT/mTOR pathway, thereby promoting migration, invasion, and proliferation of liver cancer cells. Overexpression of MMP-2/9 and activation of AKT reversed these effects on liver cancer cells caused by inhibition of ASIC1α. We conclude that ASIC1α can regulate migration, invasion, and proliferation of liver cancer cells through the MMP-2/9/PI3K/AKT/mTOR pathway. These observations may provide a new reference for liver cancer chemotherapy.

Aspirin sensitivity of PIK3CA-mutated Colorectal Cancer: potential mechanisms revisited

PIK3CA mutations are amongst the most prevalent somatic mutations in cancer and are associated with resistance to first-line treatment along with low survival rates in a variety of malignancies. There is evidence that patients carrying PIK3CA mutations may benefit from treatment with acetylsalicylic acid, commonly known as aspirin, particularly in the setting of colorectal cancer. In this regard, it has been clarified that Class IA Phosphatidylinositol 3-kinases (PI3K), whose catalytic subunit p110α is encoded by the PIK3CA gene, are involved in signal transduction that regulates cell cycle, cell growth, and metabolism and, if disturbed, induces carcinogenic effects. Although PI3K is associated with pro-inflammatory cyclooxygenase-2 (COX-2) expression and signaling, and COX-2 is among the best-studied targets of aspirin, the mechanisms behind this clinically relevant phenomenon are still unclear. Indeed, there is further evidence that the protective, anti-carcinogenic effect of aspirin in this setting may be mediated in a COX-independent manner. However, until now the understanding of aspirin's prostaglandin-independent mode of action is poor. This review will provide an overview of the current literature on this topic and aims to analyze possible mechanisms and targets behind the aspirin sensitivity of PIK3CA-mutated cancers.

Circ_0051079 silencing inhibits the malignant phenotypes of osteosarcoma cells by the TRIM66/Wnt/β-catenin pathway in a miR-625-5p-dependent manner

•

Circ_0051079 was significantly increased in OS tissues and cells.

•

Circ_0051079 knockdown inhibited OS cell malignant progression.

•

Circ_0051079 regulated TRIM66 expression through miR-625-5p.

•

Circ_0051079 mediated the Wnt/β-catenin pathway by regulating TRIM66.

Background

Methods

Results

Conclusion

Long noncoding RNA CASC7 is a novel regulator of glycolysis in oesophageal cancer via a miR-143-3p-mediated HK2 signalling pathway

Long noncoding RNAs have been proven to play a crucial role in many tumours. Here, we explored the role of the lncRNA cancer susceptibility candidate 7 (CASC7) in oesophageal cancer. LncRNA CASC7 was identified in our database analysis, and we found that it was significantly higher in oesophageal tumour tissue than in normal tissue and that high expression of lncRNA CASC7 predicted a poor prognosis. Furthermore, we verified through cell experiments that low expression of lncRNA CASC7 in oesophageal cancer cells significantly inhibited tumour proliferation, which could be explained by the effect of lncRNA CASC7 on aerobic glycolysis. Next, we found that the expression of CASC7 and hexokinase 2 (HK2) in oesophageal cancer was positively correlated in database analysis, and this conclusion was further verified in cell experiments. To determine the mechanism, we found that miR-143-3p can bind to both lncRNA CASC7 and HK2. In clinical specimens, we also found high expression of lncRNA CASC7 in tumours, and the expression levels of lncRNA CASC7 and HK2 were positively correlated. In conclusion, downregulating lncRNA CASC7 could inhibit tumour proliferation by reducing glycolysis through the miR-143-3p/HK2 axis.

Integrating adipocyte insulin signaling and metabolism in the multi-omics era

Insulin stimulates glucose uptake into adipocytes via mTORC2/AKT signaling and GLUT4 translocation and directs glucose carbons into glycolysis, glycerol for TAG synthesis, and de novo lipogenesis. Adipocyte insulin resistance is an early indicator of type 2 diabetes in obesity, a worldwide health crisis. Thus, understanding the interplay between insulin signaling and central carbon metabolism pathways that maintains adipocyte function, blood glucose levels, and metabolic homeostasis is critical. While classically viewed through the lens of individual enzyme-substrate interactions, advances in mass spectrometry are beginning to illuminate adipocyte signaling and metabolic networks on an unprecedented scale, yet this is just the tip of the iceberg. Here, we review how 'omics approaches help to elucidate adipocyte insulin action in cellular time and space.

Increased eEF2K Promotes Glycolysis and Aggressive Behaviors of Fibroblast-Like Synoviocytes in Rheumatoid Arthritis

Objective

Aggressive phenotype and abnormal glycolytic metabolism of fibroblast-like synoviocytes (FLSs) are essential to joint inflammation and damage in rheumatoid arthritis (RA). Eukaryotic elongation factor-2 kinase (eEF2K) is a negative regulator of protein synthesis and has been shown to play an important role in regulating various cellular processes and promoting glycolysis in tumor cells. However, the role of eEF2K in regulating the pathogenic FLS behaviors is unknown.

Methods

A specific inhibitor of eEF2K, NH125, and siRNA were used to evaluate the role of eEF2K on RA FLSs in vitro. Collagen-induced arthritis (CIA) mice were used to evaluate the in vivo effect of eEF2K. Cell migration, invasion of RA FLSs were assessed by transwell or wound healing assays. Relative changes of cytokines were analyzed by quantitative real-time PCR, western blot and ELISA.

Results

Herein, we found an increased expression of eEF2K in synovial tissues and FLSs of RA patients. eEF2K knockdown by siRNA or treatment with NH125, an inhibitor of eEF2K, significantly reduced inflammation, migration/invasion, glucose uptake and lactate productions. eEF2K knockdown suppressed TNF-α-induced activation of NF-κB and AKT pathways in RA FLSs. Lactate reversed the inhibitory effect of eEF2K knockdown on inflammation and migration of RA FLSs. Moreover, lactate was also involved in eEF2K-mediated activation of NF-κB and AKT. NH125 treatment attenuated the severity of arthritis in collagen-induced arthritis mice.

Conclusion

eEF2K inhibition suppressed glycolysis and aggressive behaviors of RA FLS, which indicated that targeting eEF2K may be a new strategy for the treatment of RA.

Validating Cell Surface Proteases as Drug Targets for Cancer Therapy: What Do We Know, and Where Do We Go?

Simple Summary

Cell surface proteases (so-called ectoproteases) are associated with cancer, and their targeting may confer valuable options for the improvement of cancer treatment outcome. Over the past 20 years, the permanent development of a multitude of inhibitors against several ectoproteases (including DPP4, FAP, APN, ADAM17, MMP2, and MMP9) has made it into clinical evaluation in haematological and solid tumours. Among them, a few show some efficacy, albeit limited, to cure cancer in the near future. This Review summarizes the efforts thus far undertaken in the development of ectoprotease inhibitors and highlights new directions for targeting ectoproteases as an additional weapon in the fight against cancer.

Abstract

Cell surface proteases (also known as ectoproteases) are transmembrane and membrane-bound enzymes involved in various physiological and pathological processes. Several members, most notably dipeptidyl peptidase 4 (DPP4/CD26) and its related family member fibroblast activation protein (FAP), aminopeptidase N (APN/CD13), a disintegrin and metalloprotease 17 (ADAM17/TACE), and matrix metalloproteinases (MMPs) MMP2 and MMP9, are often overexpressed in cancers and have been associated with tumour dysfunction. With multifaceted actions, these ectoproteases have been validated as therapeutic targets for cancer. Numerous inhibitors have been developed to target these enzymes, attempting to control their enzymatic activity. Even though clinical trials with these compounds did not show the expected results in most cases, the field of ectoprotease inhibitors is growing. This review summarizes the current knowledge on this subject and highlights the recent development of more effective and selective drugs targeting ectoproteases among which small molecular weight inhibitors, peptide conjugates, prodrugs, or monoclonal antibodies (mAbs) and derivatives. These promising avenues have the potential to deliver novel therapeutic strategies in the treatment of cancers.

Stromal Cells Promote Matrix Deposition, Remodelling and an Immunosuppressive Tumour Microenvironment in a 3D Model of Colon Cancer

Simple Summary

Colorectal cancer is the third most common type of cancer in the world. Immune cells and normal supporting cells (MSCs) within a tumour affect patient survival and change how well treatments work. This research aimed to develop a more relevant 3D cancer model that combines MSCs and immune cells with cancer cells to test the effects of multiple cell types on tumour growth. We successfully developed a 3D model that shows that MSCs and immune cells can change the cancer-supporting environment around the tumour cells. We show that combining MSCs and immune cells with cancer cells can increase the level of immune-suppressing molecules they release and change immunotherapeutic drug targets on the cancer cells, similar to changes seen in human tumours. Using this 3D model for research may be better for testing new drugs than traditional 2D methods and could enable the identification of new drug targets.

Abstract

Colorectal cancer (CRC) is the third leading cause of cancer-related deaths worldwide. CRC develops in a complex tumour microenvironment (TME) with both mesenchymal stromal cells (MSCs) and immune infiltrate, shown to alter disease progression and treatment response. We hypothesised that an accessible, affordable model of CRC that combines multiple cell types will improve research translation to the clinic and enable the identification of novel therapeutic targets. A viable gelatine-methacrloyl-based hydrogel culture system that incorporates CRC cells with MSCs and a monocyte cell line was developed. Gels were analysed on day 10 by PCR, cytokine array, microscopy and flow cytometry. The addition of stromal cells increased transcription of matrix remodelling proteins FN1 and MMP9, induced release of tumour-promoting immune molecules MIF, Serpin E1, CXCL1, IL-8 and CXCL12 and altered cancer cell expression of immunotherapeutic targets EGFR, CD47 and PD-L1. Treatment with PD153035, an EGFR inhibitor, revealed altered CRC expression of PD-L1 but only in gels lacking MSCs. We established a viable 3D model of CRC that combined cancer cells, MSCs and monocytic cells that can be used to research the role the stroma plays in the TME, identify novel therapeutic targets and improve the transitional efficacy of therapies.

Hexokinases 2 promoted cell motility and distant metastasis by elevating fibronectin through Akt1/p-Akt1 in cervical cancer cells

Background

Hexokinases 2 (HK2) is a member of the hexokinases, linking with malignant tumor growth and distant metastasis. However, evidence regarding the potential role of HK2 in regulating cell motility and tumor metastasis during the cervical cancer malignant progression remains limited.

Methods

In vitro migration and invasion assay, in vivo metastasis experiments were performed to detect the effective of HK2 on regulating cell motility and tumor metastasis in cervical cancer cells. RNA-Seq was performed to explore the potential molecules that participate in HK2-mediated cell motility and tumor metastasis in cervical cancer cells. The correlation between HK2 and Akt1, p-Akt1, FN1 expression in cervical cancer cells and human squamous cervical carcinoma (SCC) samples was verified in this study.

Results

In this study, cervical cancer cells with exogenous HK2 expression exhibited enhanced cell motility and distant metastasis. Transcriptome sequencing analysis revealed that fibronectin (FN1) was significantly increased in HK2-overexpressing HeLa cells, and the PI3K/Akt signaling pathway was identified by KEGG pathway enrichment analysis. Further studies demonstrated that this promotion of cell motility by HK2 was probably a result of it inducing FN1, MMP2 and MMP9 expression by activating Akt1 in cervical cancer cells. Additionally, HK2 expression was altered with the changing of Akt1/p-Akt1 expression, implying that HK2 expression is also modulated by Akt1/p-Akt1. Moreover, the positive correlation between HK2 and Akt1, p-Akt1, FN1 expression in human squamous cervical carcinoma (SCC) samples was verified by using Pearson correlation analysis.

Conclusions

This study demonstrated that HK2 could activate Akt1 in cervical cancer cells, subsequently enhancing cell motility and tumor metastasis by inducing FN1, MMP2 and MMP9 expression. There likely exists an interactive regulatory mechanism between HK2 and Akt1 during the malignant process of cervical cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02312-0.

D-MT prompts the anti-tumor effect of oxaliplatin by inhibiting IDO expression in a mouse model of colon cancer

Colon cancer is one of the most common malignant tumors in the digestive system. Although oxaliplatin, a chemotherapy drug, has been clinically used to treat colon cancer, its therapeutic effect is unsatisfactory. It has been proved that indoleamine dioxygenase 2,3 (IDO) is a tumor immunosuppressive factor for the immune response. Herein, an IDO inhibitor, D-MT (indoximod, 1-Methyl-D-tryptophan), was combined with oxaliplatin to treat colon cancer in mice. T cell infiltration in tumor tissues, the ratios of immune cells in the spleens, and the tumor growth and survival of the mice were detected and recorded. The results showed that the combination of oxaliplatin and D-MT significantly inhibited tumor growth and prolonged the survival of tumor-bearing mice. More importantly, the combination treatment increased the ratios of CD4⁺ T, CD8⁺ T and NK cells from the spleen in tumor-bearing mice, and prompted T cell infiltration in tumor tissues. This study provided a new therapeutic strategy for colon cancer treatment in the clinic, especially for patients with oxaliplatin resistance.

Hexokinase 2 in Cancer: A Prima Donna Playing Multiple Characters

Hexokinases are a family of ubiquitous exose-phosphorylating enzymes that prime glucose for intracellular utilization. Hexokinase 2 (HK2) is the most active isozyme of the family, mainly expressed in insulin-sensitive tissues. HK2 induction in most neoplastic cells contributes to their metabolic rewiring towards aerobic glycolysis, and its genetic ablation inhibits malignant growth in mouse models. HK2 can dock to mitochondria, where it performs additional functions in autophagy regulation and cell death inhibition that are independent of its enzymatic activity. The recent definition of HK2 localization to contact points between mitochondria and endoplasmic reticulum called Mitochondria Associated Membranes (MAMs) has unveiled a novel HK2 role in regulating intracellular Ca²⁺ fluxes. Here, we propose that HK2 localization in MAMs of tumor cells is key in sustaining neoplastic progression, as it acts as an intersection node between metabolic and survival pathways. Disrupting these functions by targeting HK2 subcellular localization can constitute a promising anti-tumor strategy.

Long Non-Coding RNA AC118344.1 Promotes Gastric Cancer Cell Proliferation, Invasion, and Metastasis via AKT2 and Its Downstream Molecules HK2 and MMP2

Background

Gastric cancer (GC) is a highly occurring cancer with poor prognosis. Reports indicate that long non-coding RNA (LncRNA) potentially regulates tumor progression. Herein, we aim to explore the effect of LncRNA AC118344.1 on the progression of gastric cancer.

Methods

Overexpression and knockout experiments were used to clarify the potential molecular signaling mechanisms induced by AC118344.1. CCK-8, transwell and in vivo metastasis assay were used to detect the function of AC118344.1 in AGS and SGC-7901 cells. Additionally, shRNA silencing techniques, qRT-PCR and Western blot assay were used to explore the relationship between AC118344.1, AKT2, and its downstream molecules.

Results

Upregulating the expression of AC118344.1 induces cell proliferation, invasion in vitro, and lung metastasis in vivo whereas downregulating the expression of AC118344.1 inhibits these effects. Besides, silencing the expression of AC118344.1 downregulated the expression of AKT2 in both the two cells. On the other hand, silencing the expression of AKT2 by shRNA was unable to downregulate the expression of AC118344.1 in both the gastric cancer cells. Also, AC118344.1 regulated AKT2 via its downstream molecules including HK2 and MMP2.

Conclusion

AC118344.1 promotes gastric cancer cell proliferation and invasion and lung metastasis in nude mice by upregulating the expression of AKT2 and its downstream molecules (HK2 and MMP2). Therefore, our findings provide a novel mechanism of the AC118344.1-AKT2-HK2/MMP2 axis in regulating the development of gastric cancer cells.

AKT2 drives cancer progression and is negatively modulated by miR-124 in human lung adenocarcinoma

BACKGROUND

AKT2 is highly expressed in many human cancers, including non-small cell lung cancer (NSCLC). Accumulating evidence has also revealed that AKT2 can promote NSCLC cell proliferation and metastasis. However, the involved mechanism remains unclear. Herein, our study mainly explored the function of AKT2 during cancer progression and uncovered a new post-transcriptional mechanism of AKT2 expression in lung adenocarcinoma (LUAD).

METHODS

Quantitative real-time (qRT-PCR), western blot and immunohistochemistry (IHC) assays were performed to detect the expression of AKT2 and other proteins. Cell counting kit-8 (CCK-8), colony formation and EdU assays were performed to assess cell proliferation. Flow cytometry analysis was used to detect changes in the cell cycle and apoptosis. Transwell assays were used to evaluate cell migration and invasion. Additionally, a luciferase reporter assay and western blotting were employed to assess miR-124 targeting of AKT2. Xenograft mouse model was used to observe the role of miR-124/AKT2 axis on the occurrence and development of LUAD.

RESULTS

We showed that AKT2 was highly expressed in NSCLC tissues and closely related to the poor prognosis of LUAD patients. Moreover, AKT2 affected LUAD cell proliferation, migration and invasion by regulating the cell cycle and promoting the occurrence of epithelial-mesenchymal transition (EMT) and the expression of matrix metalloproteinases (MMPs). In addition, we demonstrated that miR-124 overexpression downregulated AKT2 expression by binding to the 3'-untranslated region (3'- UTR) of AKT2 and thus inhibited the occurrence and development of LUAD in vivo and in vitro.

CONCLUSIONS

Our results suggest that miR-124 overexpression can negatively regulate AKT2 and thus inhibit the progression of LUAD. Therefore, the miR-124/AKT2 axis may serve as a potential target for novel therapies for LUAD.

Up-regulated ANP32E promotes the thyroid carcinoma cell proliferation and migration via activating AKT/mTOR/HK2-mediated glycolysis

Thyroid cancer (THCA) is one of the most common endocrine tumors and keeps rapidly increasing worldwide. Acidic nuclear phosphoprotein 32 family member E (ANP32E) is a H2A.Z histone chaperone that regulates the expression of various genes. It has been shown that ANP32E promotes breast cancer development, whereas its role in THCA remains unknown. In this study, we found that ANP32E was significantly overexpressed in THCA tissues. Down-regulation of ANP32E inhibited the growth, cell cycle progression, DNA synthesis, glycolysis, migration and increased apoptosis in K1 and TPC-1 cells. Opposite results were observed in ANP32E-overexpressing THCA cells. At the molecular level, ANP32E up-regulated MMP9 and MMP13, and activated AKT/mTOR/HK2 signaling in THCA cells. Positive correlation between ANP32E and HK2 was found in THCA tissues. Importantly, silencing of HK2 repressed glycolysis. Inhibition of AKT/mTOR reduced cell proliferation, cell cycle progression and migration in THCA cells. Our findings suggest that ANP32E promotes THCA cell proliferation and migration via potentiating AKT/mTOR/HK2-mediated glycolysis.

Oral and intestinal bacterial exotoxins: Potential linked to carcinogenesis

Growing evidence suggests that imbalances in resident microbes (dysbiosis) can promote chronic inflammation, immune-subversion, and production of carcinogenic metabolites, thus leading to neoplasia. Yet, evidence to support a direct link of individual bacteria species to human sporadic cancer is still limited. This chapter focuses on several emerging bacterial toxins that have recently been characterized for their potential oncogenic properties toward human orodigestive cancer and the presence of which in human tissue samples has been documented. These include cytolethal distending toxins produced by various members of gamma and epsilon Proteobacteria, Dentilisin from mammalian oral Treponema, Pasteurella multocida toxin, two Fusobacterial toxins, FadA and Fap2, Bacteroides fragilis toxin, colibactin, cytotoxic necrotizing factors and α-hemolysin from Escherichia coli, and Salmonella enterica AvrA. It was clear that these bacterial toxins have biological activities to induce several hallmarks of cancer. Some toxins directly interact with DNA or chromosomes leading to their breakdowns, causing mutations and genome instability, and others modulate cell proliferation, replication and death and facilitate immune evasion and tumor invasion, prying specific oncogene and tumor suppressor pathways, such as p53 and β-catenin/Wnt. In addition, most bacterial toxins control tumor-promoting inflammation in complex and diverse mechanisms. Despite growing laboratory evidence to support oncogenic potential of selected bacterial toxins, we need more direct evidence from human studies and mechanistic data from physiologically relevant experimental animal models, which can reflect chronic infection in vivo, as well as take bacterial-bacterial interactions among microbiome into consideration.

Inflammation and tissue homeostasis: the NF-κB system in physiology and malignant progression

Disruption of tissue function activates cellular stress which triggers a number of mechanisms that protect the tissue from further damage. These mechanisms involve a number of homeostatic modules, which are regulated at the level of gene expression by the transactivator NF-κB. This transcription factor shifts between activation and repression of discrete, cell-dependent gene expression clusters. Some of its target genes provide feedback to NF-κB itself, thereby strengthening the inflammatory response of the tissue and later terminating inflammation to facilitate restoration of tissue homeostasis. Disruption of key feedback modules for NF-κB in certain cell types facilitates the survival of clones with genomic aberrations, and protects them from being recognized and eliminated by the immune system, to enable thereby carcinogenesis.

Long Noncoding RNA NEAT1 Promotes Cell Proliferation And Invasion And Suppresses Apoptosis In Hepatocellular Carcinoma By Regulating miRNA-22-3p/akt2 In Vitro And In Vivo

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most aggressive cancers that is associated with cirrhosis and other chronic liver diseases. Although remarkable progress has been made in past decades, it is still necessary to continue exploring the pathology and development of HCC.

OBJECTIVE

In this study, we elucidated the effect of long noncoding RNA (lncRNA) NEAT1 on HCC development and underlying mechanisms.

METHODS

Clinicopathological features of HCC patients were collected and the correlations with NEAT1 expression were assessed. To determine cell activities, CCK-8, flow cytometry, invasion assays, and TUNEL assays were performed. Real-time PCR, Western blot, and luciferase reporter assays were performed to investigate the related mechanism of HCC.

RESULTS

The results revealed that NEAT1 expression was associated with tumor size and differentiation where NEAT1 was upregulated in both HCC tissues and cell lines. Overexpression of NEAT1 promoted proliferation and invasion while inhibited apoptosis in HCC cells, which was opposite to the effect of NEAT1 knockdown. Also, AKT2 was increased in HCC tissues. Downregulation of AKT2 was associated with reduced cell proliferation and invasion while increased apoptosis, while overexpression of AKT2 exerted opposite roles. In addition, the expression of miRNA-22-3p displayed an inverse association with NEAT1. miRNA-22-3p mimic and inhibitor suppressed and promoted HCC development, respectively. The luciferase assay revealed that both NEAT1 and AKT2 were direct target genes of miRNA-22-3p. Furthermore, knockdown and overexpression of NEAT1 suppressed and promoted tumor growth in the HCC mouse model, which were abolished by the miRNA-22-3p inhibitor and mimic, respectively.

CONCLUSION

In conclusion, the results demonstrate that NEAT1 promotes the development of HCC, both in vitro and in vivo, through regulating miRNA-22-3p/AKT2, and provides insight into developing a new strategy for HCC treatment.