GLUT1 expression in malignant tumors and its use as an immunodiagnostic marker

Targeting Pivotal Hallmarks of Cancer for Enhanced Therapeutic Strategies in Triple-Negative Breast Cancer Treatment-In Vitro, In Vivo and Clinical Trials Literature Review

This literature review provides a comprehensive overview of triple-negative breast cancer (TNBC) and explores innovative targeted therapies focused on specific hallmarks of cancer cells, aiming to revolutionize breast cancer treatment. TNBC, characterized by its lack of expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2), presents distinct features, categorizing these invasive breast tumors into various phenotypes delineated by key elements in molecular assays. This article delves into the latest advancements in therapeutic strategies targeting components of the tumor microenvironment and pivotal hallmarks of cancer: deregulating cellular metabolism and the Warburg effect, acidosis and hypoxia, the ability to metastasize and evade the immune system, aiming to enhance treatment efficacy while mitigating systemic toxicity. Insights from in vitro and in vivo studies and clinical trials underscore the promising effectiveness and elucidate the mechanisms of action of these novel therapeutic interventions for TNBC, particularly in cases refractory to conventional treatments. The integration of targeted therapies tailored to the molecular characteristics of TNBC holds significant potential for optimizing clinical outcomes and addressing the pressing need for more effective treatment options for this aggressive subtype of breast cancer.

Value of glucose transport protein 1 expression in detecting lymph node metastasis in patients with colorectal cancer

BACKGROUND

There are limited data on the use of glucose transport protein 1 (GLUT-1) expression as a biomarker for predicting lymph node metastasis in patients with colorectal cancer. GLUT-1 and GLUT-3, hexokinase (HK)-II, and hypoxia-induced factor (HIF)-1 expressions may be useful biomarkers for detecting primary tumors and lymph node metastasis when combined with fluorodeoxyglucose (FDG) uptake on positron emission tomography/computed tomography (PET/CT).

AIM

To evaluate GLUT-1, GLUT-3, HK-II, and HIF-1 expressions as biomarkers for detecting primary tumors and lymph node metastasis with 18F-FDG-PET/CT.

METHODS

This retrospective study included 169 patients with colorectal cancer who underwent colectomy and preoperative 18F-FDG-PET/CT at Chungbuk National University Hospital between January 2009 and May 2012. Two tissue cores from the central and peripheral areas of the tumors were obtained and were examined by a dedicated pathologist, and the expressions of GLUT-1, GLUT-3, HK-II, and HIF-1 were determined using immunohistochemical staining. We analyzed the correlations among their expressions, various clinicopathological factors, and the maximum standardized uptake value (SUVmax) of PET/CT.

RESULTS

GLUT-1 was found at the center or periphery of the tumors in 109 (64.5%) of the 169 patients. GLUT-1 positivity was significantly correlated with the SUVmax of the primary tumor and lymph nodes, regardless of the biopsy site (tumor center, P < 0.001 and P = 0.012; tumor periphery, P = 0.030 and P = 0.010, respectively). GLUT-1 positivity and negativity were associated with higher and lower sensitivities of PET/CT, respectively, for the detection of lymph node metastasis, regardless of the biopsy site. GLUT3, HK-II, and HIF-1 expressions were not significantly correlated with the SUVmax of the primary tumor and lymph nodes.

CONCLUSION

GLUT-1 expression was significantly correlated with the SUVmax of 18F-FDG-PET/CT for primary tumors and lymph nodes. Clinicians should consider GLUT-1 expression in preoperative endoscopic biopsy in interpreting PET/CT findings.

Biological role of fructose in the male reproductive system: Potential implications for prostate cancer

BACKGROUND

Over the last 20 years, fructose has gradually emerged as a potential metabolic substrate capable of promoting the growth and progression of various cancers, including prostate cancer (PCa). The biological and molecular mechanisms that underlie the effects of fructose on cancer are beginning to be elucidated.

METHODS

This review summarizes the biological function of fructose as a potential carbon source for PCa cells and its role in the functionality of the male reproductive tract under normal conditions.

RESULTS

The most recent biological advances related to fructose transport and metabolism as well as their implications in PCa growth and progression suggest that fructose represent a potential carbon source for PCa cells. Consequently, fructose derivatives may represent efficient radiotracers for obtaining PCa images via positron emission tomography and fructose transporters/fructose-metabolizing enzymes could be utilized as potential diagnostic and/or predictive biomarkers for PCa.

CONCLUSION

The existing data suggest that restriction of fructose from the diet could be a useful therapeutic strategy for patients with PCa.

Study of expression of GLUT-1 in oral potentially malignant disorders and oral squamous cell carcinoma: An immuno-histochemical analysis

Background

Glucose is the chief source of energy for cells, and glucose transporter 1 (GLUT-1) is one of the most common glucose transporters in humans. Tumour cells are known to express hypoxia-related protein, and these may allow tumour cells to survive under a sustained hypoxic environment. Surviving cells develop a more aggressive phenotype, which results in poor prognosis.

Aims and Objectives

Expression and comparison of GLUT-1 in normal tissues, potentially malignant disorders (PMDs), and oral squamous cell carcinoma (OSCC) and comparison of expression in different grades of OSCC.

Material and Methods

A total of 57 cases (10 normal, 17 PMD, and 30 cases of OSCC) were stained immuno-histochemically with GLUT-1. The expression was scored as 0, 1, 2, 3, and 4 for negative, mild, moderate, severe, and intense staining, respectively.

Results

GLUT-1 expression was detected in all grades of OSCC. A significant correlation was found on comparing normal and OSCC, normal and PMDs, and PMD and OSCC. The expression of GLUT-1 was significant when compared with different histopathological grades of OSCC.

Conclusions

Expression of GLUT-1 increased from normal to PMDs to increasing grades of OSCC and hence can be used as a prognostic predictive marker for OSCC.

Metabolic Interplay in the Tumor Microenvironment: Implications for Immune Function and Anticancer Response

Malignant tumors exhibit rapid growth and high metabolic rates, similar to embryonic stem cells, and depend on aerobic glycolysis, known as the "Warburg effect". This understanding has enabled the use of radiolabeled glucose analogs in tumor staging and therapeutic response assessment via PET scans. Traditional treatments like chemotherapy and radiotherapy target rapidly dividing cells, causing significant toxicity. Despite immunotherapy's impact on solid tumor treatment, gaps remain, leading to research on cancer cell evasion of immune response and immune tolerance induction via interactions with the tumor microenvironment (TME). The TME, consisting of immune cells, fibroblasts, vessels, and the extracellular matrix, regulates tumor progression and therapy responses. TME-targeted therapies aim to transform this environment from supporting tumor growth to impeding it and fostering an effective immune response. This review examines the metabolic disparities between immune cells and cancer cells, their impact on immune function and therapeutic targeting, the TME components, and the complex interplay between cancer cells and nontumoral cells. The success of TME-targeted therapies highlights their potential to achieve better cancer control or even a cure.

Prognostic value of glucose transporter proteins-1 (GLUT1) in breast carcinoma

Several studies have reported increased glucose transporters (GLUT) expression in different cancer types, including breast cancer. The primary purpose of this study is to examine GLUT1 immunoexpression in breast cancer patients in Saudi Arabia and to determine its significance. The study examined the association between GLUT1 immunophenotype and the clinicopathological characteristics in breast cancer. GLUT1 expression was analyzed in retrospectively collected tissue samples (n = 578) from breast cancer patients using immunohistochemistry. A total of 311 (54%) of the cases expressed GLUT1 cytoplasmic immunohistochemical staining. In univariate analysis, we found a significant association between GLUT1 expression and high-grade tumors (p < 0.0001). Positive estrogen and progesterone receptor results predicted lower GLUT1 immunoexpression (p < 0.0001 for both). Vascular invasion showed a significant association with GLUT1 immunoexpression (p = 0.045). Our findings support that GLUT1 immunohistochemistry can be used as a marker to determine the grade and hormonal receptor status in breast cancer.

Inverse correlation between Alzheimer's disease and cancer from the perspective of hypoxia

Sporadic Alzheimer's disease and cancer remain epidemiologically inversely related, and exploring the reverse pathogenesis is important for our understanding of both. Cognitive dysfunctions in Alzheimer's disease (AD) might result from the depletion of adaptive reserves in the brain. Energy storage in the brain is limited and is dynamically regulated by neurovascular and neurometabolic coupling. The research on neurodegenerative diseases has been dominated by the neurocentric view that neuronal defects cause the diseases. However, the proposal of the 2-hit vascular hypothesis in AD led us to focus on alterations in the vasculature, especially hypoperfusion. Chronic hypoxia is a feature shared by AD and cancer. It is interesting how contradicting chronic hypoxia's effects on both cancer and AD are. In this article, we discuss the potential links between the 2 diseases' etiology, from comparable upstream circumstances to diametrically opposed downstream effects. We suggest opposing potential mechanisms, including upregulation and downregulation of hypoxia-inducible factor-1α, the Warburg and reverse-Warburg effects, lactate-mediated intracellular acidic and alkaline conditions, and VDAC1-mediated apoptosis and antiapoptosis, and search for regulators that may be identified as the crossroads between cancer and AD.

Metabolic Phenotype Intricacies on Altered Glucose Metabolism of Breast Cancer Cells upon Glut-1 Inhibition and Mimic Hypoxia In Vitro

Breast cancer is the frequently diagnosed cancer and the leading cancer death among women. The growing tumour of the breast is composed of both normoxic and hypoxic cells, and the heterogeneity of tumour affects the targeted treatment strategies against breast cancer. The functional and therapeutic status of the Warburg effect is mostly recognized, and the genes involved in glycolysis have become a target for anticancer therapeutic strategies. Glut-1 is essential for basal glucose uptake among the glucose transporters and could act as a potential target for anticancer therapy. In the present study, we explored the alteration in the metabolic phenotype of SKBR-3 cells, representing HER-2 overexpressed breast cancer cell line, with Glut-1 inhibition by a synthetic small molecule inhibitor WZB117 in the presence or absence of cobalt chloride (CoCl2) induced biochemical hypoxia in vitro. We found that WZB117 and CoCl2 in combination could inhibit metabolic phenotype characteristics such as glucose uptake, cell migration, lactate and ATP production in SKBR-3 cells. Also, Glut-1 inhibition induced apoptosis and cell cycle arrest at the G0-G1 phase even under CoCl2-induced mimic hypoxia. Our findings suggest that Glut-1 inhibition by WZB117 could overcome the protective effect of CoCl2 mimic hypoxia by regulating glycolysis and altering the metabolic phenotype of breast cancer cells. The considering excellent efficacy and minimal toxicity suggest that WZB117 may be a promising anticancer drug to the current therapies.

Tumour follower cells: A novel driver of leader cells in collective invasion (Review)

Collective cellular invasion in malignant tumours is typically characterized by the cooperative migration of multiple cells in close proximity to each other. Follower cells are led away from the tumour by specialized leader cells, and both cell populations play a crucial role in collective invasion. Follower cells form the main body of the migration system and depend on intercellular contact for migration, whereas leader cells indicate the direction for the entire cell population. Although collective invasion can occur in epithelial and non‑epithelial malignant neoplasms, such as medulloblastoma and rhabdomyosarcoma, the present review mainly provided an extensive analysis of epithelial tumours. In the present review, the cooperative mechanisms of contact inhibition locomotion between follower and leader cells, where follower cells coordinate and direct collective movement through physical (mechanical) and chemical (signalling) interactions, is summarised. In addition, the molecular mechanisms of follower cell invasion and metastasis during remodelling and degradation of the extracellular matrix and how chemotaxis and lateral inhibition mediate follower cell behaviour were analysed. It was also demonstrated that follower cells exhibit genetic and metabolic heterogeneity during invasion, unlike leader cells.

Deciphering the Mysterious Relationship between the Cross-Pathogenetic Mechanisms of Neurodegenerative and Oncological Diseases

The relationship between oncological pathologies and neurodegenerative disorders is extremely complex and is a topic of concern among a growing number of researchers around the world. In recent years, convincing scientific evidence has accumulated that indicates the contribution of a number of etiological factors and pathophysiological processes to the pathogenesis of these two fundamentally different diseases, thus demonstrating an intriguing relationship between oncology and neurodegeneration. In this review, we establish the general links between three intersecting aspects of oncological pathologies and neurodegenerative disorders, i.e., oxidative stress, epigenetic dysregulation, and metabolic dysfunction, examining each process in detail to establish an unusual epidemiological relationship. We also focus on reviewing the current trends in the research and the clinical application of the most promising chemical structures and therapeutic platforms that have a modulating effect on the above processes. Thus, our comprehensive analysis of the set of molecular determinants that have obvious cross-functional pathways in the pathogenesis of oncological and neurodegenerative diseases can help in the creation of advanced diagnostic tools and in the development of innovative pharmacological strategies.

Low-temperature photothermal-induced alkyl radical release facilitates dihydroartemisinin-triggered "valve-off" starvation therapy

The high nutrient and energy demand of tumor cells compared to normal cells to sustain rapid proliferation offer a potentially auspicious avenue for implementing starvation therapy. However, conventional starvation therapy, such as glucose exhaustion and vascular thrombosis, can lead to systemic toxicity and exacerbate tumor hypoxia. Herein, we developed a new "valve-off" starvation tactic, which was accomplished by closing the valve of glucose transporter protein 1 (GLUT1). Specifically, dihydroartemisinin (DHA), 2,20-azobis [2-(2-imidazolin-2-yl) propane] dihydrochloride (AI), and Ink were co-encapsulated in a sodium alginate (ALG) hydrogel. Upon irradiation with the 1064 nm laser, AI rapidly disintegrated into alkyl radicals (R•), which exacerbated the DHA-induced mitochondrial damage through the generation of reactive oxygen species and further reduced the synthesis of adenosine triphosphate (ATP). Simultaneously, the production of R• facilitated DHA-induced starvation therapy by suppressing GLUT1, which in turn reduced glucose uptake. Systematic in vivo and in vitro results suggested that this radical-enhanced "valve-off" strategy for inducing tumor cell starvation was effective in reducing glucose uptake and ATP levels. This integrated strategy induces tumor starvation with efficient tumor suppression, creating a new avenue for controlled, precise, and concerted tumor therapy.

Prognostic impact of the combination of HIF‑1α and GLUT1 in patients with oesophageal squamous cell carcinoma

Oesophageal squamous cell carcinoma (ESCC) is a common type of carcinoma. Hypoxia is associated with chemo- and radio-resistance, which may lead to a poor prognosis. Hypoxia-inducible factor-1α (HIF-1α) is the main transcriptional regulator of the cellular response to low oxygen levels. Moreover, it can trigger the expression of critical genes, including glucose transporter protein type 1 (GLUT1). The aim of the present study was to evaluate the roles of HIF-1α and GLUT1 in ESCC and their usefulness as prognostic markers. HIF-1α and GLUT1 were measured in four ESCC cell lines, namely Eca109, KYSE150, TE-1 and TE-10, by western blotting following culture under normoxic and hypoxic conditions. In addition, xenograft tumors were established in mice using normoxic and hypoxic Eca109 cells and the chemosensitivity of the xenografts to 5-fluorouracil (5-FU) was evaluated. Furthermore, HIF-1α and GLUT1 were analysed by immunochemistry in the tumor tissues of patients with ESCC and the associations of their expression levels with clinicopathological parameters were investigated. The results revealed that HIF-1α and GLUT1 protein expression was weak in all four cell lines under a normoxic atmosphere but increased following culture in a hypoxic environment. In vivo, 5-FU inhibited tumor growth more strongly in normoxic Eca109 ×enografts than hypoxic Eca109 ×enografts. Higher levels of apoptosis were also detected in the normoxic Eca109 ×enografts via western blotting and TUNEL analysis. In patients with ESCC, HIF-1α expression was associated with advanced ESCC while GLUT1 expression was associated with the sex of the patients. Multivariate analysis demonstrated that HIF-1α and GLUT1 were negatively associated with progression-free survival (PFS) and overall survival (OS). Additionally, a combination of HIF-1α and GLUT1 expression was a predictor of RFS and OS in patients with ESCC without lymph node metastasis but not those with lymph node metastasis. The study demonstrated that HIF-1α and GLUT1 were strongly expressed in vitro and in xenograft models when cells were exposed to hypoxia. The simultaneous high expression of HIF-1α and GLUT1 was associated with poorer survival, and may play an important role in ESCC chemoresistance and the prognosis of ESCC.

The Effect of GLUT1 and HIF-1α Expressions on Glucose Uptake and Patient Survival in Non-Small-Cell Lung Carcinoma

Lung cancer is the second-most-common cancer while being the leading cause of cancer deaths worldwide. It has been found that glucose transporter 1 (GLUT1) and hypoxia-inducible factor 1α (HIF-1α) are overexpressed in various malignancies and that they correlate with the maximum standard uptake values (SUVmax) on 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG PET/CT) and poor prognosis. In this study, we aim to evaluate the relationship between the SUVmax, GLUT1, and HIF-1α expression with primary tumor size, histological type, lymph node metastases, and patient survival. Of the 48 patients with non-small-cell lung cancer, those with squamous cell carcinomas (SCCs) had significantly higher GLUT1 and HIF-1α immunohistochemical expressions in comparison to adenocarcinomas (ACs), while there was no statistically significant difference in FDG accumulation between them. No significant correlation was noted between either GLUT1 or HIF-1α protein expression and FDG uptake and overall survival. However, an analysis of tumor transcriptomics showed a significant difference in overall survival depending on mRNA expression; patients with SCC and high HIF-1α levels survived longer compared to those with low HIF-1α levels, while patients with AC and low GLUT1 levels had a higher average survival time than those with high GLUT1 levels. Further studies are needed to determine the prognostic value of the expression of these factors depending on the histologic type.

Functional importance of glucose transporters and chromatin epigenetic factors in Glioblastoma Multiforme (GBM): possible therapeutics

Glioblastoma Multiforme (GBM) is an aggressive brain cancer affecting glial cells and is chemo- and radio-resistant. Glucose is considered the most vital energy source for cancer cell proliferation. During metabolism, hexose molecules will be transported into the cells via transmembrane proteins known as glucose transporter (GLUT). Among them, GLUT-1 and GLUT-3 play pivotal roles in glucose transport in GBM. Knockdown studies have established the role of GLUT-1, and GLUT-3 mediated glucose transport in GBM cells, providing insight into GLUT-mediated cancer signaling and cancer aggressiveness. This review focussed on the vital role of GLUT-1 and GLUT-3 proteins, which regulate glucose transport. Recent studies have identified the role of GLUT inhibitors in effective cancer prevention. Several of them are in clinical trials. Understanding and functional approaches towards glucose-mediated cell metabolism and chromatin epigenetics will provide valuable insights into the mechanism of cancer aggressiveness, cancer stemness, and chemo-resistance in Glioblastoma Multiforme (GBM). This review summarizes the role of GLUT inhibitors, micro-RNAs, and long non-coding RNAs that aid in inhibiting glucose uptake by the GBM cells and other cancer cells leading to the identification of potential therapeutic, prognostic as well as diagnostic markers. Furthermore, the involvement of epigenetic factors, such as microRNAs, in regulating glycolytic genes was demonstrated.

Anthracycline cardiotoxicity: current methods of diagnosis and possible role of 18F-FDG PET/CT as a new biomarker

Despite advances in chemotherapy, the drugs used in cancer treatment remain rather harmful to the cardiovascular system, causing structural and functional cardiotoxic changes. Positron-emission tomography associated with computed tomography (PET/CT) has emerged like a promising technique in the early diagnosis of these adverse drug effects as the myocardial tissue uptake of fluorodeoxyglucose labeled with fluorine-18 (¹⁸F-FDG), a glucose analog, is increased after their use. Among these drugs, anthracyclines are the most frequently associated with cardiotoxicity because they promote heart damage through DNA breaks, and induction of an oxidative, proinflammatory, and toxic environment. This review aimed to present the scientific evidence available so far regarding the use of ¹⁸F-FDG PET/CT as an early biomarker of anthracycline-related cardiotoxicity. Thus, it discusses the physiological basis for its uptake, hypotheses to justify its increase in the myocardium affected by anthracyclines, importance of ¹⁸F-FDG PET/CT findings for cardio-oncology, and primary challenges of incorporating this technique in standard clinical oncology practice.

The metabolic crosstalk between PIN1 and the tumour microenvironment

Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN1) is a member of a family of peptidyl-prolyl isomerases that specifically recognizes and binds phosphoproteins, catalyzing the rapid cis-trans isomerization of phosphorylated serine/threonine-proline motifs, which leads to changes in the structures and activities of the targeted proteins. Through this complex mechanism, PIN1 regulates many hallmarks of cancer including cell autonomous metabolism and the crosstalk with the cellular microenvironment. Many studies showed that PIN1 is largely overexpressed in cancer turning on a set of oncogenes and abrogating the function of tumor suppressor genes. Among these targets, recent evidence demonstrated that PIN1 is involved in lipid and glucose metabolism and accordingly, in the Warburg effect, a characteristic of tumor cells. As an orchestra master, PIN1 finely tunes the signaling pathways allowing cancer cells to adapt and take advantage from a poorly organized tumor microenvironment. In this review, we highlight the trilogy among PIN1, the tumor microenvironment and the metabolic program rewiring.

A review on the roles and molecular mechanisms of MAFG-AS1 in oncogenesis

Long non-coding RNAs (lncRNAs) have more than 200 nucleotides and do not encode proteins. At the same time, they can regulate various biological functions and therefore play an essential role as oncogenes or tumor suppressors in human cancers. MAFG-AS1 is an antisense RNA of MAF BZIP Transcription Factor G (MAFG) located at chromosome 17q25.3 head-to-head with the MAFG encoding gene containing a transcript size of 1895 bp. Accumulating evidence shows that MAFG-AS1 is overexpressed in many cancers, functions as an oncogene, and is significantly associated with poor clinical characteristics and prognosis. In this review, we first discuss the recent literature regarding the role of MAFG-AS1 in different cancers as well as its diagnostic and prognostic values. Then we will provide insights into its biological functions, such as its role in cancer progression, competing endogenous RNA (ceRNA) activity, regulation of EMT, glycolysis, energy metabolism, transcription factors, proteasomal degradation, and signaling pathways.

GLUT1 and PKM2 may be useful prognostic predictors in patients with non‑small cell lung cancer following curative R0 resection

Lung cancer has a poor prognosis despite recent progresses being made regarding its treatment. In addition, there is a paucity of reliable and independent prognostic predictors for non-small cell lung cancer (NSCLC) following curative resection. Glycolysis is associated with the malignancy and proliferation of cancer cells. Glucose transporter 1 (GLUT1) promotes glucose uptake, whereas pyruvate kinase M2 (PKM2) promotes anaerobic glycolysis. The present study aimed to evaluate the relationship between the expression of GLUT1 and PKM2 and the clinicopathological features of patients with NSCLC, and to identify a reliable prognostic factor for NSCLC following curative resection. Patients with NSCLC who underwent curative surgery were retrospectively enrolled to the present study. GLUT1 and PKM2 expression was assessed using immunohistochemistry. Subsequently, the association between the clinicopathological features of patients with NSCLC and the expression of GLUT1 and PKM2 was assessed. Of the 445 patients with NSCLC included in the present study, 65 (15%) were positive for both GLUT1 and PKM2 expression (G+/P+ group). GLUT1 and PKM2 positivity was significantly associated with sex, absence of adenocarcinoma, lymphatic invasion and pleural invasion. Furthermore, patients with NSCLC in the G+/P+ group presented significantly poorer survival rates than those expressing other markers. G+/P+ expression was significantly associated with poor disease-free survival. In conclusion, the findings of the present study indicated that the combination of GLUT1 and PKM2 may be considered a reliable prognostic factor for patients with NSCLC following curative resection, especially in patients with stage I NSCLC.

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.

Trend in biodegradable porous nanomaterials for anticancer drug delivery

In recent years, biodegradable nanomaterials have exhibited remarkable promise for drug administration to tumors due to their high drug-loading capacity, biocompatibility, biodegradability, and clearance. This review will discuss and summarize the trends in utilizing biodegradable nanomaterials for anticancer drug delivery, including biodegradable periodic mesoporous organosilicas (BPMOs) and metal-organic frameworks (MOFs). The distinct structure and features of BPMOs and MOFs will be initially evaluated, as well as their use as delivery vehicles for anticancer drug delivery applications. Then, the themes for the development of each material will be utilized to illustrate their drug delivery performance. Finally, the current obstacles and potential for future development as efficient drug delivery systems will be thoroughly reviewed. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Fighting Carcinogenesis with Plant Metabolites by Weakening Proliferative Signaling and Disabling Replicative Immortality Networks of Rapidly Dividing and Invading Cancerous Cells

BACKGROUND

Cancer, an uncontrolled multistage disease causing swift division of cells, is a leading disease with the highest mortality rate. Cellular heterogeneity, evading growth suppressors, resisting cell death, and replicative immortality drive the tumor progression by resisting the therapeutic action of existing anticancer drugs through a series of intrinsic and extrinsic cellular interactions. The innate cellular mechanisms also regulate the replication process as a fence against proliferative signaling, enabling replicative immortality through telomere dysfunction.

AREA COVERED

The conventional genotoxic drugs have several off-target and collateral side effects associated with them. Thus, the need for the therapies targeting cyclin-dependent kinases or P13K signaling pathway to expose cancer cells to immune destruction, deactivation of invasion and metastasis, and maintaining cellular energetics is imperative. Compounds with anticancer attributes isolated from plants and rich in alkaloids, terpenes, and polyphenols have proven to be less toxic and highly targetspecific, making them biologically significant. This has opened a gateway for the exploration of more novel plant molecules by signifying their role as anticancer agents in synergy and alone, making them more effective than the existing cytotoxic regimens.

EXPERT OPINION

In this context, the current review presented recent data on cancer cases around the globe, along with discussing the fundamentals of proliferative signaling and replicative immortality of cancer cells. Recent findings were also highlighted, including antiproliferative and antireplicative action of plant-derived compounds, besides explaining the need for improving drug delivery systems.

Endosomal Sorting Protein SNX27 and Its Emerging Roles in Human Cancers

SNX27 belongs to the sorting nexin (SNX) family of proteins that play a critical role in protein sorting and trafficking in the endocytosis pathway. This protein family is characterized by the presence of a Phox (PX) domain; however, SNX27 is unique in containing an additional PDZ domain. Recently, SNX27 has gained popularity as an important sorting protein that is associated with the retromer complex and mediates the recycling of internalized proteins from endosomes to the plasma membrane in a PDZ domain-dependent manner. Over 100 cell surface proteins have been identified as binding partners of the SNX27-retromer complex. However, the roles and underlying mechanisms governed by SNX27 in tumorigenesis remains to be poorly understood. Many of its known binding partners include several G-protein coupled receptors, such as β2-andrenergic receptor and parathyroid hormone receptor, are associated with multiple pathways implicated in oncogenic signaling and tumorigenesis. Additionally, SNX27 mediates the recycling of GLUT1 and the activation of mTORC1, both of which can regulate intracellular energy balance and promote cell survival and proliferation under conditions of nutrient deprivation. In this review, we summarize the structure and fundamental roles of SNX proteins, with a focus on SNX27, and provide the current evidence indicating towards the role of SNX27 in human cancers. We also discuss the gap in the field and future direction of SNX27 research. Insights into the emerging roles and mechanism of SNX27 in cancers will provide better development strategies to prevent and treat tumorigenesis.

Discovery of highly potent and selective 7-ethyl-10-hydroxycamptothecin-glucose conjugates as potential anti-colorectal cancer agents

7-Ethyl-10-hydroxycamptothecin (SN38), a highly potent metabolite of irinotecan, has an anticancer efficacy 100-1000 folds more than irinotecan in vitro. However, the clinical application of SN38 has been limited due to the very narrow therapeutic window and poor water solubility. Herein, we report the SN38-glucose conjugates (Glu-SN38) that can target cancer cells due to their selective uptake via glucose transporters, which are overexpressed in most cancers. The in vitro antiproliferative activities against human cancer cell lines and normal cells of Glu-SN38 were investigated. One of the conjugates named 5b showed high potency and selectivity against human colorectal cancer cell line HCT116. Furthermore, 5b remarkably inhibited the growth of HCT116 in vivo. These results suggested that 5b could be a promising drug candidate for treating colorectal cancer.

An appraisal of the current status of inhibition of glucose transporters as an emerging antineoplastic approach: Promising potential of new pan-GLUT inhibitors

Neoplastic cells displayed altered metabolism with accelerated glycolysis. Therefore, these cells need a mammoth supply of glucose for which they display an upregulated expression of various glucose transporters (GLUT). Thus, novel antineoplastic strategies focus on inhibiting GLUT to intersect the glycolytic lifeline of cancer cells. This review focuses on the current status of various GLUT inhibition scenarios. The GLUT inhibitors belong to both natural and synthetic small inhibitory molecules category. As neoplastic cells express multiple GLUT isoforms, it is necessary to use pan-GLUT inhibitors. Nevertheless, it is also necessary that such pan-GLUT inhibitors exert their action at a low concentration so that normal healthy cells are left unharmed and minimal injury is caused to the other vital organs and systems of the body. Moreover, approaches are also emerging from combining GLUT inhibitors with other chemotherapeutic agents to potentiate the antineoplastic action. A new pan-GLUT inhibitor named glutor, a piperazine-one derivative, has shown a potent antineoplastic action owing to its inhibitory action exerted at nanomolar concentrations. The review discusses the merits and limitations of the existing GLUT inhibitory approach with possible future outcomes.

The history of small extracellular vesicles and their implication in cancer drug resistance

Small extracellular vesicles (EVs) in the last 20 years are demonstrated to possess promising properties as potential new drug delivery systems, biomarkers, and therapeutic targets. Moreover, EVs are described to be involved in the most important steps of tumor development and progression including drug resistance. The acquired or intrinsic capacity of cancer cells to resist chemotherapies is one of the greatest obstacles to overcome to improve the prognosis of many patients. EVs are involved in this mechanism by exporting the drugs outside the cells and transferring the drug efflux pumps and miRNAs in recipient cells, in turn inducing drug resistance. In this mini-review, the main mechanisms by which EVs are involved in drug resistance are described, giving a rapid and clear overview of the field to the readers.

Targeting O-GlcNAcylation to overcome resistance to anti-cancer therapies

In cancer cells, metabolic reprogramming is associated with an alteration of the O-GlcNAcylation homeostasis. This post-translational modification (PTM) that attaches O-GlcNAc moiety to intracellular proteins is dynamically and finely regulated by the O-GlcNAc Transferase (OGT) and the O-GlcNAcase (OGA). It is now established that O-GlcNAcylation participates in many features of cancer cells including a high rate of cell growth, invasion, and metastasis but little is known about its impact on the response to therapies. The purpose of this review is to highlight the role of O-GlcNAc protein modification in cancer resistance to therapies. We summarize the current knowledge about the crosstalk between O-GlcNAcylation and molecular mechanisms underlying tumor sensitivity/resistance to targeted therapies, chemotherapies, immunotherapy, and radiotherapy. We also discuss potential benefits and strategies of targeting O-GlcNAcylation to overcome cancer resistance.

Importance of GLUT Transporters in Disease Diagnosis and Treatment

Facilitative sugar transporters (GLUTs) are the primary method of sugar uptake in all mammalian cells. There are 14 different types of those transmembrane proteins, but they transport only a handful of substrates, mainly glucose and fructose. This overlap and redundancy contradict the natural tendency of cells to conserve energy and resources, and has led researchers to hypothesize that different GLUTs partake in more metabolic roles than just sugar transport into cells. Understanding those roles will lead to better therapeutics for a wide variety of diseases and disorders. In this review we highlight recent discoveries of the role GLUTs play in different diseases and disease treatments.

Development of Sesamol Carbamate-L-Phenylalanine Prodrug Targeting L-Type Amino Acid Transporter1 (LAT1) as a Potential Antiproliferative Agent against Melanoma

Sesamol is a compound reported to have anti-melanogenesis and anti-melanoma actions. Sesamol, however, has low intracellular drug concentration and fast excretion, which can limit its benefits in the clinic. To overcome this drawback and increase intracellular delivery of sesamol into the target melanoma, research has focused on L-type amino acid transporter 1 (LAT1)-mediated prodrug delivery into melanoma cells. The sesamol prodrug was designed by conjugating sesamol with L-phenylalanine at the para position with a carbamate bond. LAT1 targeting was evaluated vis-à-vis a competitive [¹⁴C]-leucine uptake inhibition. The sesamol prodrug has a higher [¹⁴C]-leucine uptake inhibition than sesamol in human LAT1-transfected HEK293 cells. Moreover, the sesamol prodrug was taken up by LAT1-mediated transport into SK-MEL-2 cells more effectively than sesamol. The sesamol prodrug underwent complete hydrolysis, releasing the active sesamol at 72 h, which significantly exerted its cytotoxicity (IC₅₀ of 29.3 µM) against SK-MEL-cells more than sesamol alone. Taken together, the strategy for LAT1-mediated prodrug delivery has utility for the selective uptake of sesamol, thereby increasing its intracellular concentration and antiproliferation activity, targeting melanoma SK-MEL-2 cells that overexpress the LAT1 protein. The sesamol prodrug thus warrants further evaluation in an in vivo model.

Historical perspective of tumor glycolysis: A century with Otto Warburg

Tumors have long been known to rewire their metabolism to endorse their proliferation, growth, survival, and invasiveness. One of the common characteristics of these alterations is the enhanced glucose uptake and its subsequent transformation into lactic acid by means of glycolysis, regardless the availability of oxygen or the mitochondria effectiveness. This phenomenon is called the "Warburg effect", which has turned into a century of age now, since its first disclosure by German physiologist Otto Heinrich Warburg. Since then, this peculiar metabolic switch in tumors has been addressed by extensive studies covering several areas of research. In this historical perspective, we aim at illustrating the evolution of these studies over time and their implication in various fields of science.

Local problems need global solutions - the metabolic needs of regenerating organisms

The vast majority of species that belong to the plant or animal kingdom evolved with two main strategies to counter tissue damage - scar formation and regeneration. Whereas scar formation provides a fast and cost-effective repair to exit life-threatening conditions, complete tissue regeneration is time-consuming and requires vast resources to reinstall functionality of affected organs or structures. Local environments in wound healing are widely studied and findings have provided important biomedical applications. Less well understood are organismic physiological parameters and signaling circuits essential to maintain effective tissue repair. Here, we review accumulated evidence that positions the interplay of local and systemic changes in metabolism as essential variables modulating the injury response. We particularly emphasize the role of lipids and lipid-like molecules as significant components long overlooked. This article is protected by copyright. All rights reserved.

Diaminobutoxy-substituted Isoflavonoid (DBI-1) Enhances the Therapeutic Efficacy of GLUT1 Inhibitor BAY-876 by Modulating Metabolic Pathways in Colon Cancer Cells

Cancer cells undergo significant "metabolic remodeling" to provide sufficient ATP to maintain cell survival and to promote rapid growth. In colorectal cancer cells, ATP is produced by mitochondrial oxidative phosphorylation and by substantially elevated cytoplasmic glucose fermentation (i.e., the Warburg effect). Glucose transporter 1 (GLUT1) expression is significantly increased in colorectal cancer cells, and GLUT1 inhibitors block glucose uptake and hence glycolysis crucial for cancer cell growth. In addition to ATP, these metabolic pathways also provide macromolecule building blocks and signaling molecules required for tumor growth. In this study, we identify a diaminobutoxy-substituted isoflavonoid (DBI-1) that inhibits mitochondrial complex I and deprives rapidly growing cancer cells of energy needed for growth. DBI-1 and the GLUT1 inhibitor, BAY-876, synergistically inhibit colorectal cancer cell growth in vitro and in vivo. This study suggests that an electron transport chain inhibitor (i.e., DBI-1) and a glucose transport inhibitor, (i.e., BAY-876) are potentially effective combination for colorectal cancer treatment.

GLUT1 and ASCT2 Protein Expression in Papillary Thyroid Carcinoma Patients and Relation to Hepatitis C Virus: A Propensity-Score Matched Analysis

Purpose

Recently, glucose and amino acid transporters have gradually become a hot topic in thyroid gland biology and cancer research. We aimed to investigate the expressions of glucose transporter 1 (GLUT1) and glutamine transporter 2 (ASCT2) in papillary thyroid carcinoma (PTC) and their clinical significance and relation to HCV-related hepatitis.

Patients and Methods

Screening 202 TC tissue samples against the selection criteria using a propensity-score matched analysis to adjust for age, sex, side of tumor, histopathological variants, TNM staging system, and the positivity for HCV yielded 51 matched (17 HCV positive and 34 HCV negative) PTC samples. The expressions of GLUT1 and ASCT2 expressions were detected by immunohistochemical staining. Kaplan–Meier survival curves were generated for disease-free and overall survival, and multivariate Cox regression analysis was applied to identify predictors for mortality.

Results

Of 51 thyroid cancer tissues, 85% showed positive GLUT1 cytoplasmic staining, and 26% had a high expression score. All thyroid cancer specimens demonstrated ASCT2 cytoplasmic staining with membranous accentuation. Of these, 78% showed a high expression score, and 22% showed weak staining. On stratifying the study cohort based on the HCV status, HCV negative cohort showed a significantly higher immunoreactivity score for GLUT1 (p = 0.004) but not ASCT2 (p = 0.94) than HCV positive group. The expressions of the studied transporters showed no significant associations with the prognostic features of PTC nor the disease-free/overall survival.

Conclusion

GLUT1 and ASCT2 immunohistochemical staining showed positive expression with variable intensity in nearly 85% and 100% of PTC tissue samples compared to normal ones, respectively. Furthermore, GLUT1 protein expression, not ASCT2, showed a higher immunoreactivity score in PTC patients who are negative for HCV than cancer patients with positive HCV. Meanwhile, the expression of both protein markers was not associated with the clinicopathological characteristics of the studied PTC patients. Further large-scale multicenter studies are recommended to validate the present findings.

Glucose transporters as markers of diagnosis and prognosis in cancer diseases

The primary metabolic substrate for cells is glucose, which acts as both a source of energy and a substrate in several processes. However, being lipophilic, the cell membrane is impermeable to glucose and specific carrier proteins are needed to allow transport. In contrast to normal cells, cancer cells are more likely to generate energy by glycolysis; as this process generates fewer molecules of adenosine triphosphate (ATP) than complete oxidative breakdown, more glucose molecules are needed. The increased demand for glucose in cancer cells is satisfied by overexpression of a number of glucose transporters, and decreased levels of others. As specific correlations have been observed between the occurrence of cancer and the expression of glucose carrier proteins, the presence of changes in expression of glucose transporters may be treated as a marker of diagnosis and/or prognosis for cancer patients.

Glucose transporter 1 expression in ameloblastoma and odontogenic keratocyst - A comparative immunohistochemical study

INTRODUCTION

Facilitative glucose transporters (GLUTs), which mediate glucose transport across the cell membrane, differ in their tissue distribution and affinity for glucose. GLUT1 is ubiquitously present and help in the basal uptake of glucose into the cells. Its expression is known to be elevated in conditions that induce hypoxia and by growth factors. GLUT1 is known to be increased in many malignant tumors to meet the metabolic requirements, but its role in odontogenic tumors is not known.

OBJECTIVE

The objective of this study is to evaluate and compare the immunohistochemical expression of GLUT1 in ameloblastoma (AM) and odontogenic keratocyst (OKC).

MATERIALS AND METHODOLOGY

Thirty cases each of AM and OKCs were immunohistochemically stained using anti-GLUT1 antibody according to the standard protocol. Qualitative assessment of GLUT1 expression was done under the categories of distribution, intensity and localization of staining. Quantitative assessment was done using Image J software. The results were tabulated and statistically analyzed.

RESULTS

GLUT1 positivity was observed in 25 (83.3%) cases of OKC and 26 (86.7%) of AM cases. The majority of cells in the suprabasal layer of OKC showed positivity, whereas the equal distribution of staining was observed in the central and peripheral cells of AM.

CONCLUSION

GLUT1 expression in these tumors is suggestive of an increased glucose uptake and probably increased utilization of energy, which may be correlated with their aggressive behavior.

Unraveling the Role of STK11/LKB1 in Non-small Cell Lung Cancer

There are two major groups of lung cancer: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). NSCLCs can be further separated into three different categories: lung adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. Pulmonary adenocarcinomas represent nearly half of all lung cancer cases and are known to be caused by smoking, certain occupational exposures, and specific genetic mutations. Scientists have noticed that most NSCLCs are driven by defects in the following genes: EGFR, BRAF, ALK, MET, and HER. Abnormalities in the STK11/LKB1 gene have also been shown to induce lung adenocarcinoma. LKB1-deficient cancer cells contain an overactive AMPK “energy sensor,” which inhibits cellular death and promotes glucose, lipid, and protein synthesis via the mTOR protein complex. Studies have also discovered that the loss of STK11/LKB1 favors oncogenesis by creating an immunosuppressive environment for tumors to grow and accelerate events such as angiogenesis, epithelial-mesenchymal transition (EMT), and cell polarity destabilization. STK11/LKB1-mutant lung cancers are currently treated with radiotherapy with or without chemotherapy. Recent clinical trials studying the effects of glutaminase inhibitors, mTOR inhibitors, and anti-PD-L1 therapy in lung cancer patients have yielded promising results. This narrative review provides an overview of the STK11/LKB1 gene and its role in cancer development. Additionally, a summary of the LKB1/APMK/mTOR is provided.

Complex cellular environments imaged by SERS nanoprobes using sugars as an all-in-one vector

Raman spectroscopy coupled with confocal microscopy offers an alternative bioimaging technique overcoming limitations associated with sensitivity, tissue penetration and image resolution. Allied to the surface-enhanced Raman scattering (SERS) properties of gold nanoparticles (AuNP), we designed SERS nanoprobes with enhanced properties and straightforward application as bio-labelling agents for gliomas. The ensuing nanoprobes coated with simple sugar units (galactose or glucose) allowed assessing information about their intracellular localization (vesicular structures), with impressive sensitivity towards complex environments and proved the ability to overcome biological auto-fluorescence and high penetration in tissues. We validate the use of sugars as an all-in-one vector (Raman reporter, conferring high stability, biocompatibility and affinity to glioma cells) as imaging agents using an impressive technique.

A Novel Prognostic Biomarker Panel for Early-Stage Colon Carcinoma

Molecular characterization of colorectal cancer has helped us understand better the biology of the disease. However, previous efforts have yet to provide significant clinical value in order to be integrated into clinical practice for patients with early-stage colon cancer (CC). The purpose of this study was to assess PD-L1, GLUT-1, e-cadherin, MUC2, CDX2, and microsatellite instability (dMMR) and to propose a risk-panel with prognostic capabilities. Biomarkers were immunohistochemically assessed through tissue microarrays in a cohort of 144 patients with stage II/III colon cancer. A biomarker panel consisting of PD-L1, GLUT-1, dMMR, and potentially CDX2 was constructed that divided patients into low, medium, and high risk of overall survival or disease-free survival (DFS) in equally sized groups. Compared with low-risk patients, medium-risk patients have almost twice the risk of death (HR = 2.10 (0.99-4.46), p = 0.054), while high-risk patients have almost four times the risk (HR = 3.79 (1.77-8.11), p = 0.001). The multivariate goodness of fit was 0.756 and was correlated with Kaplan-Meier curves (p = 0.002). Consistent results were found for DFS. This study provides a critical basis for the future development of an immunohistochemical assessment capable of discerning early-stage CC patients as a function of their prognosis. This tool may aid with treatment personalization in daily clinical practice and improve survival outcomes.

Viral Membrane Fusion Proteins and RNA Sorting Mechanisms for the Molecular Delivery by Exosomes

The advancement of precision medicine critically depends on the robustness and specificity of the carriers used for the targeted delivery of effector molecules in the human body. Numerous nanocarriers have been explored in vivo, to ensure the precise delivery of molecular cargos via tissue-specific targeting, including the endocrine part of the pancreas, thyroid, and adrenal glands. However, even after reaching the target organ, the cargo-carrying vehicle needs to enter the cell and then escape lysosomal destruction. Most artificial nanocarriers suffer from intrinsic limitations that prevent them from completing the specific delivery of the cargo. In this respect, extracellular vesicles (EVs) seem to be the natural tool for payload delivery due to their versatility and low toxicity. However, EV-mediated delivery is not selective and is usually short-ranged. By inserting the viral membrane fusion proteins into exosomes, it is possible to increase the efficiency of membrane recognition and also ease the process of membrane fusion. This review describes the molecular details of the viral-assisted interaction between the target cell and EVs. We also discuss the question of the usability of viral fusion proteins in developing extracellular vesicle-based nanocarriers with a higher efficacy of payload delivery. Finally, this review specifically highlights the role of Gag and RNA binding proteins in RNA sorting into EVs.

Evaluation of 18F-EF5 for detection of hypoxia in localized adenocarcinoma of the prostate

BACKGROUND

A common feature of solid tumours that are resistant to therapy is the presence of regions with low oxygen content (i.e., hypoxia). Oxygen electrode studies suggest that localized prostate adenocarcinoma is commonly hypoxic, although conflicting data have been reported between immunohistochemical detection of hypoxia-induced proteins in biopsy specimens and positron emission tomography (PET) imaging of ¹⁸F-labeled hypoxia reporters. Although the 2-nitroimidazole ¹⁸F-EF5 is well-established to label hypoxic tumour cells in pre-clinical tumour models and clinical trials of multiple primary tumour sites, it has yet to be tested in prostate cancer. The purpose of this study was to evaluate the feasibility of using ¹⁸F-EF5 to detect hypoxia in clinical prostate tumours.

MATERIAL AND METHODS

Patients with localized adenocarcinoma of the prostate were recruited for pre-treatment ¹⁸F-EF5 PET scans. Immunohistochemistry was conducted on diagnostic biopsies to assess the expression of glucose transporter 1 (GLUT1), osteopontin (OPN), and carbonic anhydrase IX (CAIX). Immunoreactivity scores of staining intensity and frequency were used to indicate the presence of tumour hypoxia.

RESULTS

We found low tumour-to-muscle ratios of ¹⁸F-EF5 uptake that were not consistent with tumour hypoxia, causing early termination of the study. However, we observed GLUT1 and OPN expression in all prostate tumour biopsies, indicating the presence of hypoxia in all tumours.

CONCLUSION

Our data do not support the use of ¹⁸F-EF5 PET to detect hypoxia in prostate adenocarcinoma, and suggest the use of immunohistochemistry to quantify expression of the hypoxia-inducible proteins GLUT1 and OPN as indications of prostate tumour hypoxia.

MicroRNAs and Metabolism: Revisiting the Warburg Effect with Emphasis on Epigenetic Background and Clinical Applications

Since the well-known hallmarks of cancer were described by Hanahan and Weinberg, fundamental advances of molecular genomic technologies resulted in the discovery of novel puzzle pieces in the multistep pathogenesis of cancer. MicroRNAs are involved in the altered epigenetic pattern and metabolic phenotype of malignantly transformed cells. They contribute to the initiation, progression and metastasis-formation of cancers, also interacting with oncogenes, tumor-suppressor genes and epigenetic modifiers. Metabolic reprogramming of cancer cells results from the dysregulation of a complex network, in which microRNAs are located at central hubs. MicroRNAs regulate the expression of several metabolic enzymes, including tumor-specific isoforms. Therefore, they have a direct impact on the levels of metabolites, also influencing epigenetic pattern due to the metabolite cofactors of chromatin modifiers. Targets of microRNAs include numerous epigenetic enzymes, such as sirtuins, which are key regulators of cellular metabolic homeostasis. A better understanding of reversible epigenetic and metabolic alterations opened up new horizons in the personalized treatment of cancer. MicroRNA expression levels can be utilized in differential diagnosis, prognosis stratification and prediction of chemoresistance. The therapeutic modulation of microRNA levels is an area of particular interest that provides a promising tool for restoring altered metabolism of cancer cells.

Emerging role of tumor-derived extracellular vesicles in T cell suppression and dysfunction in the tumor microenvironment

Immunotherapeutic drugs including immune checkpoint blockade antibodies have been approved to treat patients in many types of cancers. However, some patients have little or no reaction to the immunotherapy drugs. The mechanisms underlying resistance to tumor immunotherapy are complicated and involve multiple aspects, including tumor-intrinsic factors, formation of immunosuppressive microenvironment, and alteration of tumor and stromal cell metabolism in the tumor microenvironment. T cell is critical and participates in every aspect of antitumor response, and T cell dysfunction is a severe barrier for effective immunotherapy for cancer. Emerging evidence indicates that extracellular vesicles (EVs) secreted by tumor is one of the major factors that can induce T cell dysfunction. Tumor-derived EVs are widely distributed in serum, tissues, and the tumor microenvironment of patients with cancer, which serve as important communication vehicles for cancer cells. In addition, tumor-derived EVs can carry a variety of immune suppressive signals driving T cell dysfunction for tumor immunity. In this review, we explore the potential mechanisms employed by tumor-derived EVs to control T cell development and effector function within the tumor microenvironment. Especially, we focus on current understanding of how tumor-derived EVs molecularly and metabolically reprogram T cell fates and functions for tumor immunity. In addition, we discuss potential translations of targeting tumor-derived EVs to reconstitute suppressive tumor microenvironment or to develop antigen-based vaccines and drug delivery systems for cancer immunotherapy.

Preoperative FDG-Positive Lymph Nodes Predict the Postoperative Prognosis in Resectable Biliary Tract Cancers

BACKGROUND

F-18 fluorodeoxyglucose-positron emission tomography (FDG-PET) has been used to diagnose and stage various cancers. In regard to biliary tract cancer (BTC), due to cholangitis it is difficult to evaluate FDG uptake caused by cancer. We previously showed that FDG-positive lymph nodes (LNs) of resectable BTC had a possibility of predicting postoperative prognosis.

OBJECTIVE

This study aimed to validate the usability of FDG-PET for LNs using another cohort and to investigate in detail the relationship between FDG-positive LNs and the prognosis of BTC.

METHODS

We measured the preoperative maximum standardized uptake value (SUV_max) at each of the 190 surgically dissected LN areas in 67 patients and investigated the prognosis using our previously determined SUV_max cut-off values of ≥ 2.8.

RESULTS

Regarding the prognosis of patients with resectable BTC, a LN SUV_max ≥ 2.8 [PET N (+)] was a poor prognostic factor for recurrence-free survival (RFS) compared with a LN SUV_max < 2.8 [PET N (-)]. It was confirmed that the hazard ratio forest plot [PET N (+)/PET N (-)] for RFS indicated a similar tendency among subcategories. Moreover, we investigated patients with pN0 disease and demonstrated that the PET N (+) group also had a significantly worse RFS outcome compared with the PET N (-) group. Recurrence of the PET N (+) group has significantly occurred more often in LNs than that of the PET N (-) group.

CONCLUSION

High LN SUV_max was confirmed to be the preoperatively diagnosed prognostic risk factor for RFS in resectable BTC and could be helpful for clinical decision making regarding the perioperative treatment strategy.

Upregulated glycolysis correlates with tumor progression and immune evasion in head and neck squamous cell carcinoma

Altered metabolism is an emerging hallmark of cancer. Cancer cells preferentially utilize glycolysis for energy production, termed "aerobic glycolysis." In this study, we performed a comprehensive analysis of the glycolytic activity in head and neck squamous cell carcinoma (HNSCC) using data obtained from The Cancer Genome Atlas database. We first divided 520 patients with HNSCC into four groups based on the mRNA expression of 16 glycolysis-related genes. The upregulated glycolytic activity positively correlated with human papillomavirus-negative tumor type, advanced T factor, and unfavorable prognosis. The gene set enrichment analysis revealed upregulation of several hallmark pathways, including interferon-alpha response, myc targets, unfolded protein response, transforming growth factor-β signaling, cholesterol homeostasis, and interleukin 6-Janus kinase-signal transducer and activator of transcription 3 signaling, in the glycolysis-upregulated groups. Immune cell enrichment analysis revealed decreased infiltration of T cells, dendritic cells, and B cells in the glycolysis-upregulated groups, suggesting impaired tumor antigen presentation, T cell activation, and antibody production in the TME. Moreover, the expression profile of immune-related genes indicated increased immune evasion in the glycolysis-upregulated tumors. Collectively, these findings suggest that transcriptome analysis of glycolytic activity of tumors has the potential as a biomarker for tumor progression and immunological status in patients with HNSCC.

Clinical value of baseline 18F-FDG PET/CT in soft tissue sarcomas

Background

The use of ¹⁸F-FDG Positron emission tomography/Computed tomography (PET/CT) in the initial staging of many cancers is clearly established. Most soft tissue sarcoma (STS) has a high affinity for ¹⁸F-FDG, which is why ¹⁸F-FDG PET/CT has been proposed as a non-invasive method, useful in diagnosis and follow-up. The standardized uptake value values (SUV), the volume-based metabolic parameters MTV (metabolic tumor volume), and TLG (total lesion glycolysis) determine tumor viability and provide its total volume and the total activity of metabolically active tumor cells. The histological grade is the most important predictor of metastases and mortality associated with STS, and a significant relationship between the metabolic parameters of ¹⁸F-FDG PET/CT and the histological grade has been described.

Methods

A retrospective study was conducted on STS patients, who had histological grade according to the FNCLCC (Fédération Nationale des Centres de Lutte Contre Le Cancer) criteria, as well as a baseline PET/CT. SUV (SUV_max, SUV_mean, and SUV_peak), MTV, and TLG were quantified. A T-student test was performed to establish the relationship between the metabolic biomarkers and the histological grade. Their usefulness as predictors of the histological grade was verified using receiver operator characteristic (ROC) curves. A survival function study was performed using the Kaplan–Meier method. To assess the prognostic utility of the metabolic biomarkers we use the Log-Rank method.

Results

The SUV values were useful to discriminate high-grade STS. We found a significant relationship between the histological grade and the SUV values. SUV_max, SUV_peak, MTV, and TLG were predictors of overall survival (OS). There were no significant differences in the OS for the SUV_mean, or in the disease-free survival (DFS) for SUV_max, SUV_mean, SUV_peak, MTV, and TLG.

Conclusions

The SUV_max, SUV_mean, and SUV_peak values correlate with the HG and are useful to discriminate high-grade from low-grade STS. Patients with high SUV_max, SUV_peak, MTV, and TLG have a significantly lower OS.