Apigenin down-regulates the hypoxia response genes: HIF-1α, GLUT-1, and VEGF in human pancreatic cancer cells

Flavonoids as modulators of miRNA expression in pancreatic cancer: Pathways, Mechanisms, And Therapeutic Potential

Pancreatic cancer (PC) is a complex malignancy, distinguished by its aggressive characteristics and unfavorable prognosis. Recent developments in understanding the molecular foundations of this disease have brought attention to the noteworthy involvement of microRNAs (miRNAs) in disease development, advancement, and treatment resistance. The anticancer capabilities of flavonoids, which are a wide range of phytochemicals present in fruits and vegetables, have attracted considerable interest because of their ability to regulate miRNA expression. This review provides the effects of flavonoids on miRNA expression in PC, explains the underlying processes, and explores the possible therapeutic benefits of flavonoid-based therapies. Flavonoids inhibit PC cell proliferation, induce apoptosis, and enhance chemosensitivity via the modulation of miRNAs involved in carcinogenesis. Additionally, this review emphasizes the significance of certain miRNAs as targets of flavonoid action. These miRNAs have a role in regulating important signaling pathways such as the phosphoinositide-3-kinase-protein kinase B/Protein kinase B (Akt), mitogen activated protein kinase (MAPK), Janus kinase/signal transducers and activators of transcription (JAK/STAT), and Wnt/β-catenin pathways. This review aims to consolidate current knowledge on the interaction between flavonoids and miRNAs in PC, providing a comprehensive analysis of how flavonoid-mediated modulation of miRNA expression could influence cancer progression and therapy. It highlights the use of flavonoid nanoformulations to enhance stability, increase absorption, and maximize anti-PC activity, improving patient outcomes. The review calls for further research to optimize the use of flavonoid nanoformulations in clinical trials, leading to innovative treatment strategies and more effective approaches for PC.

The Pros and Cons of Estrogens in Prostate Cancer: An Update with a Focus on Phytoestrogens

The role of estrogens in prostate cancer (PCa) is shrouded in mystery, with its actions going from angelic to devilish. The findings by Huggins and Hodges establishing PCa as a hormone-sensitive cancer have provided the basis for using estrogens in therapy. However, despite the clinical efficacy in suppressing tumor growth and the panoply of experimental evidence describing its anticarcinogenic effects, estrogens were abolished from PCa treatment because of the adverse secondary effects. Notwithstanding, research work over the years has continued investigating the effects of estrogens, reporting their pros and cons in prostate carcinogenesis. In contrast with the beneficial therapeutic effects, many reports have implicated estrogens in the disruption of prostate cell fate and tissue homeostasis. On the other hand, epidemiological data demonstrating the lower incidence of PCa in Eastern countries associated with a higher consumption of phytoestrogens support the beneficial role of estrogens in counteracting cancer development. Many studies have investigated the effects of phytoestrogens and the underlying mechanisms of action, which may contribute to developing safe estrogen-based anti-PCa therapies. This review compiles the existing data on the anti- and protumorigenic actions of estrogens and summarizes the anticancer effects of several phytoestrogens, highlighting their promising features in PCa treatment.

Targeting the pancreatic tumor microenvironment by plant-derived products and their nanoformulations

Pancreatic cancer remains a significant health issue with limited treatment options. The tumor stroma, a complex environment made up of different cells and proteins, plays a crucial role in tumor growth and chemoresistance. Targeting tumor stroma, consisting of diverse non-tumor cells such as fibroblasts, extracellular matrix (ECM), immune cells, and also pre-vascular cells is encouraging for remodeling solid cancers, such as pancreatic cancer. Remodeling the stroma of pancreas tumors can be suggested as a strategy for reducing resistance to chemo/immunotherapy. Several studies have shown that phytochemicals from plants can affect the tumor environment and have anti-cancer properties. By targeting key pathways involved in stromal activation, phytochemicals may disrupt communication between the tumor and stroma and make tumor cells more sensitive to different treatments. Additionally, phytochemicals have immunomodulatory and anti-angiogenic properties, all of which contribute to their potential in treating pancreatic cancer. This review will provide a detailed look at how phytochemicals impact the tumor stroma and their effects on pancreatic tumor growth, spread, and response to treatment. It will also explore the potential of combining phytochemicals with other treatment options like chemotherapy, immunotherapy, and radiation.

Nature's weapons: Bioactive compounds as anti-cancer agents

Cancer represents a major global health burden, prompting continuous research for effective therapeutic strategies. Natural compounds derived from plants have emerged as potential strategies for preventing cancer and treatment because of their inherent pharmacological properties. This comprehensive review aimed to evaluate the therapeutic potential of five key natural compounds: apigenin, quercetin, piperine, curcumin, and resveratrol in cancer prevention and therapy. By examining their molecular mechanisms and preclinical evidence, this review seeks to elucidate their role as potential adjuvants or stand-alone therapies in cancer management. The exploration of natural compounds as cancer therapeutics offers several advantages, including low toxicity, wide availability, and compatibility with conventional chemotherapeutic agents. We highlighted the current understanding of their anticancer mechanisms and clinical applications for advancing personalized cancer care to improve patient outcomes. We discussed the empirical findings from in vitro, in vivo, and clinical studies reporting biological activity and therapeutic efficacy in antioxidant, immunomodulatory, anti-carcinogenic, and chemo-sensitizing modes. Innovative delivery systems and personalized treatment approaches may further enhance their bioavailability and therapeutic utility in a synergistic approach with chemo- and radiotherapeutic disease management. This review underscores the importance of natural compounds in cancer prevention and treatment, promoting a multidisciplinary approach to the development of innovative therapeutic strategies.

Metabolism and structure of PDA as the target for new therapies: possibilities and limitations for nanotechnology

INTRODUCTION

Certainly, pancreatic ductal adenocarcinoma poses one of the greatest challenges in current oncology. The dense extracellular matrix and low vessel density in PDA tumor impede the effective delivery of drugs, primarily due to the short pharmacokinetics of most drugs and potential electrostatic interactions with stroma components.

AREA COVERED

Owing to the distinctive metabolism of PDA and challenges in accessing nutrients, there is a growing interest in cell metabolism inhibitors as a potential means to inhibit cancer development. However, even if suitable combinations of inhibitors are identified, the question about their administration remains, as the same hindrances that impede effective treatment with conventional drugs will also hinder the delivery of inhibitors. Methods including nanotechnology to increase drugs in PDA penetrations are reviewed and discussed.

EXPERT OPINION

Pancreatic cancer is one of the most difficult tumors to treat due to the small number of blood vessels, high content of extracellular matrix, and specialized resistance mechanisms of tumor cells. One possible method of treating this tumor is the use of metabolic inhibitors in combinations that show synergy. Despite promising results in in vitro tests, their effect is uncertain due to the tumor's structure. In the case of pancreatic cancer, priming of the tumor tissue is required through the sequential administration of drugs that generate blood vessels, increase blood flow, and enhance vascular permeability and extracellular matrix. The use of drug carriers with a size of 10-30 nm may be crucial in the therapy of this cancer.

Flavonoids with Anti-Angiogenesis Function in Cancer

The formation of new blood vessels, known as angiogenesis, significantly impacts the development of multiple types of cancer. Consequently, researchers have focused on targeting this process to prevent and treat numerous disorders. However, most existing anti-angiogenic treatments rely on synthetic compounds and humanized monoclonal antibodies, often expensive or toxic, restricting patient access to these therapies. Hence, the pursuit of discovering new, affordable, less toxic, and efficient anti-angiogenic compounds is imperative. Numerous studies propose that natural plant-derived products exhibit these sought-after characteristics. The objective of this review is to delve into the anti-angiogenic properties exhibited by naturally derived flavonoids from plants, along with their underlying molecular mechanisms of action. Additionally, we summarize the structure, classification, and the relationship between flavonoids with their signaling pathways in plants as anti-angiogenic agents, including main HIF-1α/VEGF/VEGFR2/PI3K/AKT, Wnt/β-catenin, JNK1/STAT3, and MAPK/AP-1 pathways. Nonetheless, further research and innovative approaches are required to enhance their bioavailability for clinical application.

Modulation of hypoxia-inducible factor-1 signaling pathways in cancer angiogenesis, invasion, and metastasis by natural compounds: a comprehensive and critical review

Tumor cells employ multiple signaling mediators to escape the hypoxic condition and trigger angiogenesis and metastasis. As a critical orchestrate of tumorigenic conditions, hypoxia-inducible factor-1 (HIF-1) is responsible for stimulating several target genes and dysregulated pathways in tumor invasion and migration. Therefore, targeting HIF-1 pathway and cross-talked mediators seems to be a novel strategy in cancer prevention and treatment. In recent decades, tremendous efforts have been made to develop multi-targeted therapies to modulate several dysregulated pathways in cancer angiogenesis, invasion, and metastasis. In this line, natural compounds have shown a bright future in combating angiogenic and metastatic conditions. Among the natural secondary metabolites, we have evaluated the critical potential of phenolic compounds, terpenes/terpenoids, alkaloids, sulfur compounds, marine- and microbe-derived agents in the attenuation of HIF-1, and interconnected pathways in fighting tumor-associated angiogenesis and invasion. This is the first comprehensive review on natural constituents as potential regulators of HIF-1 and interconnected pathways against cancer angiogenesis and metastasis. This review aims to reshape the previous strategies in cancer prevention and treatment.

Targeting the Warburg effect: A revisited perspective from molecular mechanisms to traditional and innovative therapeutic strategies in cancer

Cancer reprogramming is an important facilitator of cancer development and survival, with tumor cells exhibiting a preference for aerobic glycolysis beyond oxidative phosphorylation, even under sufficient oxygen supply condition. This metabolic alteration, known as the Warburg effect, serves as a significant indicator of malignant tumor transformation. The Warburg effect primarily impacts cancer occurrence by influencing the aerobic glycolysis pathway in cancer cells. Key enzymes involved in this process include glucose transporters (GLUTs), HKs, PFKs, LDHs, and PKM2. Moreover, the expression of transcriptional regulatory factors and proteins, such as FOXM1, p53, NF-κB, HIF1α, and c-Myc, can also influence cancer progression. Furthermore, lncRNAs, miRNAs, and circular RNAs play a vital role in directly regulating the Warburg effect. Additionally, gene mutations, tumor microenvironment remodeling, and immune system interactions are closely associated with the Warburg effect. Notably, the development of drugs targeting the Warburg effect has exhibited promising potential in tumor treatment. This comprehensive review presents novel directions and approaches for the early diagnosis and treatment of cancer patients by conducting in-depth research and summarizing the bright prospects of targeting the Warburg effect in cancer.

Pancreatic ductal adenocarcinoma chemoresistance: From metabolism reprogramming to novel treatment

ABSTRACT

As pancreatic cancer (PC) is highly malignant, its patients tend to develop metastasis at an early stage and show a poor response to conventional chemotherapies. First-line chemotherapies for PC, according to current guidelines, include fluoropyrimidine- and gemcitabine-based regimens. Accumulating research on drug resistance has shown that biochemical metabolic aberrations in PC, especially those involving glycolysis and glutamine metabolism, are highly associated with chemoresistance. Additionally, lipid metabolism is a major factor in chemoresistance. However, emerging compounds that target these key metabolic pathways have the potential to overcome chemoresistance. This review summarizes how PC develops chemoresistance through aberrations in biochemical metabolism and discusses novel critical targets and pathways within cancer metabolism for new drug research.

The effect of Apigenin on glycometabolism and cell death in an anaplastic thyroid cancer cell line

AIMS AND BACKGROUND

A more pronounced characteristic of cancer cells is the energy dependence on glucose, which mitigated by glucose transporters. The comprehension of the regulatory mechanisms behind the Warburg effect holds promise for developing therapeutic interventions for cancers. Studies are lacking which targeted the GLUTs for treatment of malignancy of thyroid tumors. In our current investigation, we have undertaken this study to determine the potential of Apigenin, plant derived flavonoid in modulating tumor apoptosis by targeting GLUTs expression in SW1736 cell line of anaplastic thyroid carcinoma.

MATERIAL METHODS

Flow cytometry with propidium iodide staining was used to determine cell apoptosis. For glucose uptake detection, the "GOD-PAP" enzymatic colorimetric test was used to measure the direct glucose levels inside the cells. To determine the expression of GLUT1 and GLUT3 mRNA in the SW1736 cell line qRT-PCR was employed. Protein levels of GLUT1 and GLUT3 in the SW1736 cell line were detected with western blotting. Also, the scratch wound healing assay was conducted for cell migration.

RESULTS

According to qRT-PCR analysis, the levels of GLUT1 and GLUT3 mRNA were lower in the group that received Apigenin relative to the control group. The Apigenin treatment of SW1736 cells decreased protein expression of the GLUT1 and GLUT3 levels in conformity to qRT-PCR. The scratch assays revealed that Apigenin treatment of cancer cell lines inhibited cell migration as compared to control.

CONCLUSION

These findings demonstrate the possibility of targeting the glucose facilitators' pathway for making thyroid cancer cells more susceptible to programmed cell death.

Hypoxia-Targeted Dose Painting in Radiotherapy

Hypoxia (oxygen deprivation) occurs in most solid malignancies, albeit with considerable heterogeneity. Hypoxia is associated with an aggressive cancer phenotype by promotion of genomic instability, evasion of anti-cancer therapies including radiotherapy and enhancement of metastatic risk. Therefore, hypoxia results in poor cancer outcomes. Targeting hypoxia to improve cancer outcomes is an attractive therapeutic strategy. Hypoxia-targeted dose painting escalates radiotherapy dose to hypoxic sub-volumes, as quantified and spatially mapped using hypoxia imaging. This therapeutic approach could overcome hypoxia-induced radioresistance and improve patient outcomes without the need for hypoxia-targeted drugs. This article will review the premise and underpinning evidence for personalized hypoxia-targeted dose painting. It will present data on relevant hypoxia imaging biomarkers, highlight the challenges and potential benefit of this approach and provide recommendations for future research priorities in this field. Personalized hypoxia-based radiotherapy de-escalation strategies will also be addressed.

Apigenin in cancer therapy: Prevention of genomic instability and anticancer mechanisms

The incidence of cancer has been growing worldwide. Better survival rates following the administration of novel drugs and new combination therapies may concomitantly cause concern regarding the long-term adverse effects of cancer therapy, for example, second primary malignancies. Moreover, overcoming tumour resistance to anticancer agents has been long considered as a critical challenge in cancer research. Some low toxic adjuvants such as herb-derived molecules may be of interest for chemoprevention and overcoming the resistance of malignancies to cancer therapy. Apigenin is a plant-derived molecule with attractive properties for chemoprevention, for instance, promising anti-tumour effects, which may make it a desirable adjuvant to reduce genomic instability and the risks of second malignancies among normal tissues. Moreover, it may improve the efficiency of anticancer modalities. This paper aims to review various effects of apigenin in both normal tissues and malignancies. In addition, we explain how apigenin may have the ability to protect usual cells against the genotoxic repercussions following radiotherapy and chemotherapy. Furthermore, the inhibitory effects of apigenin on tumours will be discussed.

Natural products targeting glycolytic signaling pathways-an updated review on anti-cancer therapy

Glycolysis is a complex metabolic process that occurs to convert glucose into pyruvate to produce energy for living cells. Normal cells oxidized pyruvate into adenosine triphosphate and carbon dioxide in the presence of oxygen in mitochondria while cancer cells preferentially metabolize pyruvate to lactate even in the presence of oxygen in order to maintain a slightly acidic micro-environment of PH 6.5 and 6.9, which is beneficial for cancer cell growth and metastasis. Therefore targeting glycolytic signaling pathways provided new strategy for anti-cancer therapy. Natural products are important sources for the treatment of diseases with a variety of pharmacologic activities. Accumulated studies suggested that natural products exhibited remarkable anti-cancer properties both in vitro and in vivo. Plenty of studies suggested natural products like flavonoids, terpenoids and quinones played anti-cancer properties via inhibiting glucose metabolism targets in glycolytic pathways. This study provided an updated overview of natural products controlling glycolytic pathways, which also provide insight into druggable mediators discovery targeting cancer glucose metabolism.

Targeting Glucose Metabolism Enzymes in Cancer Treatment: Current and Emerging Strategies

Simple Summary

Reprogramming of glucose metabolism is a hallmark of cancer and can be targeted by therapeutic agents. Some metabolism regulators, such as ivosidenib and enasidenib, have been approved for cancer treatment. Currently, more advanced and effective glucose metabolism enzyme-targeted anticancer drugs have been developed. Furthermore, some natural products have shown efficacy in killing tumor cells by regulating glucose metabolism, offering novel therapeutic opportunities in cancer. However, most of them have failed to be translated into clinical applications due to low selectivity, high toxicity, and side effects. Recent studies suggest that combining glucose metabolism modulators with chemotherapeutic drugs, immunotherapeutic drugs, and other conventional anticancer drugs may be a future direction for cancer treatment.

Abstract

Reprogramming of glucose metabolism provides sufficient energy and raw materials for the proliferation, metastasis, and immune escape of cancer cells, which is enabled by glucose metabolism-related enzymes that are abundantly expressed in a broad range of cancers. Therefore, targeting glucose metabolism enzymes has emerged as a promising strategy for anticancer drug development. Although several glucose metabolism modulators have been approved for cancer treatment in recent years, some limitations exist, such as a short half-life, poor solubility, and numerous adverse effects. With the rapid development of medicinal chemicals, more advanced and effective glucose metabolism enzyme-targeted anticancer drugs have been developed. Additionally, several studies have found that some natural products can suppress cancer progression by regulating glucose metabolism enzymes. In this review, we summarize the mechanisms underlying the reprogramming of glucose metabolism and present enzymes that could serve as therapeutic targets. In addition, we systematically review the existing drugs targeting glucose metabolism enzymes, including small-molecule modulators and natural products. Finally, the opportunities and challenges for glucose metabolism enzyme-targeted anticancer drugs are also discussed. In conclusion, combining glucose metabolism modulators with conventional anticancer drugs may be a promising cancer treatment strategy.

Phytochemicals as Regulators of Tumor Glycolysis and Hypoxia Signaling Pathways: Evidence from In Vitro Studies

The full understanding of the complex nature of cancer still faces many challenges, as cancers arise not as a result of a single target disruption but rather involving successive genetic and epigenetic alterations leading to multiple altered metabolic pathways. In this light, the need for a multitargeted, safe and effective therapy becomes essential. Substantial experimental evidence upholds the potential of plant-derived compounds to interfere in several important pathways, such as tumor glycolysis and the upstream regulating mechanisms of hypoxia. Herein, we present a comprehensive overview of the natural compounds which demonstrated, in vitro studies, an effective anticancer activity by affecting key regulators of the glycolytic pathway such as glucose transporters, hexokinases, phosphofructokinase, pyruvate kinase or lactate dehydrogenase. Moreover, we assessed how phytochemicals could interfere in HIF-1 synthesis, stabilization, accumulation, and transactivation, emphasizing PI3K/Akt/mTOR and MAPK/ERK pathways as important signaling cascades in HIF-1 activation. Special consideration was given to cell culture-based metabolomics as one of the most sensitive, accurate, and comprising approaches for understanding the response of cancer cell metabolome to phytochemicals.

Hypoxia as a Modulator of Inflammation and Immune Response in Cancer

A clear association between hypoxia and cancer has heretofore been established; however, it has not been completely developed. In this sense, the understanding of the tumoral microenvironment is critical to dissect the complexity of cancer, including the reduction in oxygen distribution inside the tumoral mass, defined as tumoral hypoxia. Moreover, hypoxia not only influences the tumoral cells but also the surrounding cells, including those related to the inflammatory processes. In this review, we analyze the participation of HIF, NF-κB, and STAT signaling pathways as the main components that interconnect hypoxia and immune response and how they modulate tumoral growth. In addition, we closely examine the participation of the immune cells and how they are affected by hypoxia, the effects of the progression of cancer, and some innovative applications that take advantage of this knowledge, to suggest potential therapies. Therefore, we contribute to the understanding of the complexity of cancer to propose innovative therapeutic strategies in the future.

Effect of Glut-1 and HIF-1α double knockout by CRISPR/CAS9 on radiosensitivity in laryngeal carcinoma via the PI3K/Akt/mTOR pathway

Hypoxic resistance is the main obstacle to radiotherapy for laryngeal carcinoma. Our previous study indicated that hypoxia-inducible factor 1α (HIF-1α) and glucose transporter 1 (Glut-1) double knockout reduced tumour biological behaviour in laryngeal carcinoma cells. However, their radioresistance mechanism remains unclear. In this study, cell viability was determined by CCK8 assay. Glucose uptake capability was evaluated by measurement of ¹⁸ F-fluorodeoxyglucose radioactivity. A tumour xenograft model was established by subcutaneous injection of Tu212 cells. Tumour histopathology was determined by haematoxylin and eosin staining, immunohistochemical staining, and TUNEL assays. Signalling transduction was evaluated by Western blotting. We found that hypoxia induced radioresistance in Tu212 cells accompanied by increased glucose uptake capability and activation of the PI3K/Akt/mTOR pathway. Inhibition of PI3K/Akt/mTOR activity abolished hypoxia-induced radioresistance and glucose absorption. Mechanistic analysis revealed that hypoxia promoted higher expressions of HIF-1α and Glut-1. Moreover, the PI3K/Akt/mTOR pathway was a positive mediator of HIF-1α and/or Glut-1 in the presence of irradiation. HIF-1α and/or Glut-1 knockout significantly reduced cell viability, glucose uptake and PI3K/Akt/mTOR activity, all of which were induced by hypoxia in the presence of irradiation. In vivo analysis showed that knockout of HIF-1α and/or Glut-1 also inhibited tumour growth by promoting cell apoptosis, more robustly compared with the PI3K inhibitor wortmannin, particularly in tumours with knockout of both HIF-1α and Glut-1. HIF-1α and/or Glut-1 knockout also abrogated PI3K/Akt/mTOR signalling transduction in tumour tissues, in a manner similar to wortmannin. HIF-1α and/or Glut-1 knockout facilitated radiosensitivity in laryngeal carcinoma Tu212 cells by regulation of the PI3K/Akt/mTOR pathway.

Apigenin Increases Natural Killer Cytotoxicity to Human Hepatocellular Carcinoma Expressing HIF-1α through High Interaction of CD95/CD95L

Natural killer (NK) cell activity is more attenuated in hepatocellular carcinoma (HCC) patients than normal. Hypoxic-inducible factor (HIF)-1α is highly expressed in tumors to maintain their metabolism in a hypoxic environment. The expression of HIF-1α in cancers can lead to cell growth, proliferation, invasion/metastasis and immune escape. Although apigenin, a flavonoid, is known to have various biological activities, it has not been demonstrated in NK cell immune activity in HCC cells. In this study, NK-92 cells were directly cocultured with HCC SK-Hep1 cells for 24 h to evaluate NK cell activity in HCC cells or HCC cells expressing HIF-1α by apigenin. NK cell cytotoxicity to HCC cells expressing HIF-1α was significantly increased, and NK cell-activating receptors, NKG2D, NKp30 and NKp44 were highly expressed. The activating effect of apigenin on NK cells substantially induced apoptosis in HCC cells expressing HIF-1α through high expression of CD95L on the surface of NK-92 cells. Moreover, apigenin excellently inhibited the level of TGF-β1 in a coculture of NK cells and HCC cells. In conclusion, apigenin seems to be a good compound that increases NK cell cytotoxicity to HCC cells by controlling HIF-1α expression.

Semaphorin 3A attenuates the hypoxia suppression of osteogenesis in periodontal ligament stem cells

OBJECTIVE AND BACKGROUND

The occurrence and development of periodontitis are closely related to hypoxia of the periodontal microenvironment. Periodontal ligament stem cells (PDLSCs) are considered to have potential to regenerate periodontal tissues. Semaphorin 3A (Sema3A) plays an essential role in promoting osteogenesis. However, the effect of Sema3A on osteogenesis of PDLSCs under hypoxia remains unclear. The aim of this study was to investigate the effect of Sema3A on osteogenesis of PDLSCs under hypoxia.

METHODS

Isolated PDLSCs were identified using flow cytometry. Adipogenic differentiation potential was identified by oil red O staining. Osteogenesis was measured using Alizarin Red S staining and ALP staining. Intracellular hypoxia was induced using cobalt chloride (CoCl₂ ). The expression level of hypoxia-inducible factor-1α (HIF-1α) was detected via ELISA. Expression of osteogenic markers and Sema3A was analyzed using western blot and real-time PCR.

RESULTS

The proliferation and osteogenesis of PDLSCs were markedly inhibited with increased concentrations of CoCl₂ . Under the treatment with a low concentration of CoCl₂ , expression of related osteogenic markers and Sema3A decreased in a time-dependent manner. ARS and ALP staining results also showed that osteogenic calcification decreased under hypoxia. Apigenin, an inhibitor of HIF-1α, effectively up-regulated expression of Sema3A and osteogenic markers with CoCl₂ treatment. Moreover, exogenous Sema3A significantly increased the expression of osteogenesis-related markers and mineralization of PDLSCs according to ALP and ARS staining with CoCl₂ treatment.

CONCLUSIONS

Hypoxia markedly inhibited osteogenesis of PDLSCs. Sema3A explicitly attenuated the hypoxia suppression of osteogenesis in PDLSCs.

Phyto-targeting the CEMIP Expression as a Strategy to Prevent Pancreatic Cancer Metastasis

INTRODUCTION

Metastasis of primary pancreatic cancer (PC) to adjacent or distant organs is responsible for the poor survival rate of affected individuals. Chemotherapy, radiotherapy, and immunotherapy are currently being prescribed to treat PC in addition to surgical resection. Surgical resection is the preferred treatment for PC that leads to 20% of 5-year survival, but only less than 20% of patients are eligible for surgical resection because of the poor prognosis. To improve the prognosis and clinical outcome, early diagnostic markers need to be identified, and targeting them would be of immense benefit to increase the efficiency of the treatment. Cell migration-inducing hyaluronan-binding protein (CEMIP) is identified as an important risk factor for the metastasis of various cancers, including PC. Emerging studies have pointed out the crucial role of CEMIP in the regulation of various signaling mechanisms, leading to enhanced migration and metastasis of PC.

METHODS

The published findings on PC metastasis, phytoconstituents, and CEMIP were retrieved from Pubmed, ScienceDirect, and Cochrane Library. Computational tools, such as gene expression profiling interactive analysis (GEPIA) and Kaplan-Meier (KM) plotter, were used to study the relationship between CEMIP expression and survival of PC individuals.

RESULTS

Gene expression analysis using the GEPIA database identified a stupendous increase in the CEMIP transcript in PC compared to adjacent normal tissues. KM plotter analysis revealed the impact of CEMIP on the overall survival (OS) and disease-free survival (DFS) among PC patients. Subsequently, several risk factors associated with PC development were screened, and their ability to regulate CEMIP gene expression was analyzed using computational tools.

CONCLUSION

The current review is focused on gathering information regarding the regulatory role of phytocomponents in PC migration and exploring their possible impact on the CEMIP expression.

Apigenin Induces Autophagy and Cell Death by Targeting EZH2 under Hypoxia Conditions in Gastric Cancer Cells

Hypoxia is a major obstacle to gastric cancer (GC) therapy and leads to chemoresistance as GC cells are frequently exposed to the hypoxia environment. Apigenin, a flavonoid found in traditional medicine, fruits, and vegetables and an HDAC inhibitor, is a powerful anti-cancer agent against various cancer cell lines. However, detailed mechanisms involved in the treatment of GC using APG are not fully understood. In this study, we investigated the biological activity of and molecular mechanisms involved in APG-mediated treatment of GC under hypoxia. APG promoted autophagic cell death by increasing ATG5, LC3-II, and phosphorylation of AMPK and ULK1 and down-regulating p-mTOR and p62 in GC. Furthermore, our results show that APG induces autophagic cell death via the activation of the PERK signaling, indicating an endoplasmic reticulum (ER) stress response. The inhibition of ER stress suppressed APG-induced autophagy and conferred prolonged cell survival, indicating autophagic cell death. We further show that APG induces ER stress- and autophagy-related cell death through the inhibition of HIF-1α and Ezh2 under normoxia and hypoxia. Taken together, our findings indicate that APG activates autophagic cell death by inhibiting HIF-1α and Ezh2 under hypoxia conditions in GC cells.

Tumor Microenvironment Features and Chemoresistance in Pancreatic Ductal Adenocarcinoma: Insights into Targeting Physicochemical Barriers and Metabolism as Therapeutic Approaches

Currently, the median overall survival of PDAC patients rarely exceeds 1 year and has an overall 5-year survival rate of about 9%. These numbers are anticipated to worsen in the future due to the lack of understanding of the factors involved in its strong chemoresistance. Chemotherapy remains the only treatment option for most PDAC patients; however, the available therapeutic strategies are insufficient. The factors involved in chemoresistance include the development of a desmoplastic stroma which reprograms cellular metabolism, and both contribute to an impaired response to therapy. PDAC stroma is composed of immune cells, endothelial cells, and cancer-associated fibroblasts embedded in a prominent, dense extracellular matrix associated with areas of hypoxia and acidic extracellular pH. While multiple gene mutations are involved in PDAC initiation, this desmoplastic stroma plays an important role in driving progression, metastasis, and chemoresistance. Elucidating the mechanisms underlying PDAC resistance are a prerequisite for designing novel approaches to increase patient survival. In this review, we provide an overview of the stromal features and how they contribute to the chemoresistance in PDAC treatment. By highlighting new paradigms in the role of the stromal compartment in PDAC therapy, we hope to stimulate new concepts aimed at improving patient outcomes.

Antiproliferative and Mitochondrial Protective Effects of Apigenin in an Oxygen-Induced Retinopathy In Vivo Mouse Model

Purpose: To investigate the effects of a common dietary flavonoid apigenin on retinal endothelial cell proliferation, retinal morphological structure, and apoptotic cell death in an oxygen-induced retinopathy (OIR) mouse model to evaluate the possibility of the use of apigenin in the treatment of ocular neovascular diseases (ONDs). Methods: Ninety-six newborn C57BL/6J mice were included. Eight groups were randomized, each including 12 mice. Two negative control groups were kept in room air: the first without any injection and the second received intravitreal (IV) dimethyl sulfoxide (DMSO), which is the solvent we used. The OIR groups were exposed to 75% ± 2% oxygen from postnatal days (PD) 7 to 12. On PD 12, the mice were randomly assigned to 6 groups: 2 OIR control groups (1 received no injection, 1 received IV-DMSO), 2 IV-apigenin groups (10 and 20 μg/mL), and 2 intraperitoneal (IP)-apigenin groups (10 and 20 mg/kg). We quantified retinal endothelial cell proliferation by counting neovascular tufts in cross-sections and examined histological and ultrastructural changes through light and electron microscopy. We evaluated apoptosis by terminal deoxynucleotidyl transferase-mediated nick end-labeling (TUNEL). Results: We detected a significant increase in endothelial cell proliferation in the OIR groups. Groups receiving apigenin, both IP and IV, had significant decreases in endothelial cells, atypical mitochondrion count, and apoptotic cells compared with the groups receiving no injections. None of the apigenin-injected groups revealed cystic degeneration or cell loss. Conclusions: Apigenin suppresses neovascularization, has antiapoptotic and antioxidative effects in an OIR mouse model, and can be considered a promising agent for treating OND. Clinical trial (Project number: DA15/19).

Up-down regulation of HIF-1α in cancer progression

Hypoxia induicible factor-1 alpha (HIF-1α) is a key transcription factor in cancer progression and target therapy in cancer. HIF-1α acts differently depending on presence or absence of Oxygen. In an oxygen-immersed environment, HIF-1α completely deactivated and destroyed by the ubiquitin proteasome pathway (UPP). In contrast, in the oxygen-free environment, it escapes destruction and enters to the nucleus of cells then upregulates many genes involved in cancer progression. Overexpressed HIF-1α and downstream genes support cancer progression through various mechanisms including angiogenesis, proliferation and survival of cells, metabolism reprogramming, invasion and metastasis, cancer stem cell maintenance, induction of genetic instability, and treatment resistance. HIF-1α can be provoked by signaling pathways unrelated to hypoxia during cancer progression. Therefore, cancer development and progression can be modulated by targeting HIF-1α and its downstream signaling molecules. In this regard, HIF-1α inhibitors which are categorized into the agents that regulate HIF-1α in gene, mRNA and protein levels used as an efficient way in cancer treatment. Also, HIF-1α expression can be negatively affected by the agents suppressing the activation of mTOR, PI3k/Akt and MAPK pathways.

An Overview of the Recent Development of Anticancer Agents Targeting the HIF-1 Transcription Factor

Hypoxia, a characteristic feature of solid tumors, is associated with the malignant phenotype and therapy resistance of cancers. Hypoxia-inducible factor 1 (HIF-1), which is responsible for the metazoan adaptive response to hypoxia, has been recognized as a rational target for cancer therapy due to its critical functions in hypoxic regions. In order to efficiently inhibit its activity, extensive efforts have been made to elucidate the molecular mechanism underlying the activation of HIF-1. Here, we provide an overview of relevant research, particularly on a series of HIF-1 activators identified so far and the development of anticancer drugs targeting them.

The Hallmarks of Flavonoids in Cancer

Flavonoids represent an important group of bioactive compounds derived from plant-based foods and beverages with known biological activity in cells. From the modulation of inflammation to the inhibition of cell proliferation, flavonoids have been described as important therapeutic adjuvants against several diseases, including diabetes, arteriosclerosis, neurological disorders, and cancer. Cancer is a complex and multifactor disease that has been studied for years however, its prevention is still one of the best known and efficient factors impacting the epidemiology of the disease. In the molecular and cellular context, some of the mechanisms underlying the oncogenesis and the progression of the disease are understood, known as the hallmarks of cancer. In this text, we review important molecular signaling pathways, including inflammation, immunity, redox metabolism, cell growth, autophagy, apoptosis, and cell cycle, and analyze the known mechanisms of action of flavonoids in cancer. The current literature provides enough evidence supporting that flavonoids may be important adjuvants in cancer therapy, highlighting the importance of healthy and balanced diets to prevent the onset and progression of the disease.

Flavonoids Targeting HIF-1: Implications on Cancer Metabolism

Tumor hypoxia is described as an oxygen deprivation in malignant tissue. The hypoxic condition is a consequence of an imbalance between rapidly proliferating cells and a vascularization that leads to lower oxygen levels in tumors. Hypoxia-inducible factor 1 (HIF-1) is an essential transcription factor contributing to the regulation of hypoxia-associated genes. Some of these genes modulate molecular cascades associated with the Warburg effect and its accompanying pathways and, therefore, represent promising targets for cancer treatment. Current progress in the development of therapeutic approaches brings several promising inhibitors of HIF-1. Flavonoids, widely occurring in various plants, exert a broad spectrum of beneficial effects on human health, and are potentially powerful therapeutic tools against cancer. Recent evidences identified numerous natural flavonoids and their derivatives as inhibitors of HIF-1, associated with the regulation of critical glycolytic components in cancer cells, including pyruvate kinase M2(PKM2), lactate dehydrogenase (LDHA), glucose transporters (GLUTs), hexokinase II (HKII), phosphofructokinase-1 (PFK-1), and pyruvate dehydrogenase kinase (PDK). Here, we discuss the results of most recent studies evaluating the impact of flavonoids on HIF-1 accompanied by the regulation of critical enzymes contributing to the Warburg phenotype. Besides, flavonoid effects on glucose metabolism via regulation of HIF-1 activity represent a promising avenue in cancer-related research. At the same time, only more-in depth investigations can further elucidate the mechanistic and clinical connections between HIF-1 and cancer metabolism.

Rationalizing the therapeutic potential of apigenin against cancer

BACKGROUND

Despite the remarkable advances made in the diagnosis and treatment of cancer during the past couple of decades, it remains the second largest cause of mortality in the world, killing approximately 9.6 million people annually. The major challenges in the treatment of the advanced stage of this disease are the development of chemoresistance, severe adverse effects of the drugs, and high treatment cost. Therefore, the development of drugs that are safe, efficacious, and cost-effective remains a 'Holy Grail' in cancer research. However, the research over the past four decades shed light on the cancer-preventive and therapeutic potential of natural products and their underlying mechanism of action. Apigenin is one such compound, which is known to be safe and has significant potential in the prevention and therapy of this disease.

AIM

To assess the literature available on the potential of apigenin and its analogs in modulating the key molecular targets leading to the prevention and treatment of different types of cancer.

METHOD

A comprehensive literature search has been carried out on PubMed for obtaining information related to the sources and analogs, chemistry and biosynthesis, physicochemical properties, biological activities, bioavailability and toxicity of apigenin.

KEY FINDINGS

The literature search resulted in many in vitro, in vivo and a few cohort studies that evidenced the effectiveness of apigenin and its analogs in modulating important molecular targets and signaling pathways such as PI3K/AKT/mTOR, JAK/STAT, NF-κB, MAPK/ERK, Wnt/β-catenin, etc., which play a crucial role in the development and progression of cancer. In addition, apigenin was also shown to inhibit chemoresistance and radioresistance and make cancer cells sensitive to these agents. Reports have further revealed the safety of the compound and the adaptation of nanotechnological approaches for improving its bioavailability.

SIGNIFICANCE

Hence, the present review recapitulates the properties of apigenin and its pharmacological activities against different types of cancer, which warrant further investigation in clinical settings.

Nestin Promotes Peritoneal Fibrosis by Protecting HIF1-α From Proteasomal Degradation

Background

Peritoneal dialysis (PD) is a treatment for end stage renal disease patients, but it can also cause peritoneal fibrosis. Nestin is known as a neural stem cell marker and it has many functions. The hypoxia induced factor (HIF) signaling pathway can be activated under hypoxia conditions, leading to the overexpression of some angiogenesis related genes. The aim of our study is to demonstrate Nestin’s role in the development of peritoneal fibrosis (PF), and to provide a new target (Nestin) to treat PF.

Methods

PD mice models were constructed by an intraperitoneal administration of PDS at 10 ml/100g/d for 4 weeks. Nestin-positive cells were isolated from peritonea of Nestin-GFP mice by flow cytometry. The relationship of Nestin and HIF1-α-VEGFA pathway was detected by Nestin knockdown, Co-immunoprecipitation and immunofluorescence. Also, proteasomal activity was demonstrated by CHX and MG132 application, followed by Western blotting and Co-immunoprecipitation.

Results

In our experiments, we found that Nestin expression resulted in PF. Also, HIF1-α/VEGFA pathway was activated in PF. Nestin knockdown reduced the level of HIF1-α. Nestin directly bound to HIF1-α and protected HIF1-α from proteasomal degradation. Overexpression of HIF1-α reverts the fibrosis levels in Nestin-knockdown cells. In brief, Nestin inhibited the degradation of HIF1-α by mitigating its ubiquitination level, leading to the activation of HIF1-α signaling pathway, and eventually promoted PF.

Conclusion

We found a novel mechanism of PF that Nestin promotes by protecting HIF1-α from proteasomal degradation. Taken together, our key findings highlight a novel mechanism by which the silencing of Nestin hinders HIF1- α -induced PF.

Galectin-3 Expression in Pancreatic Cell Lines Under Distinct Autophagy-Inducing Stimulus

Hypoxia and nutrient deprivation are responsible for inducing malignant behavior in neoplastic cells. In these conditions, metabolic stress leads the cells to enhance their autophagic flux and to activate key molecules for homeostasis maintenance. Galectin-3 (Gal-3) is upregulated in pancreatic cancer and it is activated under the hypoxic atmosphere. We aimed to analyze the most effective autophagic-inducing conditions in pancreatic ductal adenocarcinoma cells and the effect exerted under these conditions in association with hypoxia on the Gal-3 expression. Gal-3 and the microtubule-associated protein light chain 3 beta (LC3) were accessed through western blot and immunofluorescence. Degradative vacuole quantification was analyzed by transmission electronic microscopy, and inhibition of Gal-3 was performed using siRNA. According to the analyses, the most effective conditions in the inducement of autophagy for PANC-1 and MIA PaCa-2 cells were nutritional deprivation and complete amino acid/glucose deprivation, respectively. PANC-1 cells presented higher Gal-3 when they were submitted to 24 h of nutritional deprivation alone and simultaneously nutritional and oxygen deprivation. Inhibition of Gal-3 causes a decrease of LC3 levels in all experimental conditions. These results confirm that Gal-3 is modulated by microenvironment factors and the possibility of Gal-3 participating in an adaptive response from PDAC cells to extreme conditions.

Apigenin as Tumor Suppressor in Cancers: Biotherapeutic Activity, Nanodelivery, and Mechanisms With Emphasis on Pancreatic Cancer

Pancreatic cancer is the most lethal malignancy of the gastrointestinal tract. Due to its propensity for early local and distant spread, affected patients possess extremely poor prognosis. Currently applied treatments are not effective enough to eradicate all cancer cells, and minimize their migration. Besides, these treatments are associated with adverse effects on normal cells and organs. These therapies are not able to increase the overall survival rate of patients; hence, finding novel adjuvants or alternatives is so essential. Up to now, medicinal herbs were utilized for therapeutic goals. Herbal-based medicine, as traditional biotherapeutics, were employed for cancer treatment. Of them, apigenin, as a bioactive flavonoid that possesses numerous biological properties (e.g., anti-inflammatory and anti-oxidant effects), has shown substantial anticancer activity. It seems that apigenin is capable of suppressing the proliferation of cancer cells via the induction of cell cycle arrest and apoptosis. Besides, apigenin inhibits metastasis via down-regulation of matrix metalloproteinases and the Akt signaling pathway. In pancreatic cancer cells, apigenin sensitizes cells in chemotherapy, and affects molecular pathways such as the hypoxia inducible factor (HIF), vascular endothelial growth factor (VEGF), and glucose transporter-1 (GLUT-1). Herein, the biotherapeutic activity of apigenin and its mechanisms toward cancer cells are presented in the current review to shed some light on anti-tumor activity of apigenin in different cancers, with an emphasis on pancreatic cancer.

Dietary Polyphenols in Cancer Chemoprevention: Implications in Pancreatic Cancer

Naturally occurring dietary agents present in a wide variety of plant products, are rich sources of phytochemicals possessing medicinal properties, and thus, have been used in folk medicine for ages to treat various ailments. The beneficial effects of such dietary components are frequently attributed to their anti-inflammatory and antioxidant properties, particularly in regards to their antineoplastic activities. As many tumor types exhibit greater oxidative stress levels that are implicated in favoring autonomous cell growth activation, most chemotherapeutic agents can also enhance tumoral oxidative stress levels in part via generating reactive oxygen species (ROS). While ROS-mediated imbalance of the cellular redox potential can provide novel drug targets, as a consequence, this ROS-mediated excessive damage to cellular functions, including oncogenic mutagenesis, has also been implicated in inducing chemoresistance. This remains one of the major challenges in the treatment and management of human malignancies. Antioxidant-enriched natural compounds offer one of the promising approaches in mitigating some of the underlying mechanisms involved in tumorigenesis and metastasis, and therefore, have been extensively explored in cancer chemoprevention. Among various groups of dietary phytochemicals, polyphenols have been extensively explored for their underlying chemopreventive mechanisms in other cancer models. Thus, the current review highlights the significance and mechanisms of some of the highly studied polyphenolic compounds, with greater emphasis on pancreatic cancer chemoprevention.

Apigenin Attenuates the Allergic Reactions by Competitively Binding to ER With Estradiol

Apigenin (API) is a natural phytoestrogen with properties including anti-inflammatory and other abilities. This study aims to 1) systematically validate that excessive estrogen exacerbates allergic reactions; 2) explore the anti-allergic effects and mechanisms of API. We conduct a survey of college students, indicating that of the 505 effective results, 70 individuals were self-reported allergic and 74.1% of them were women, which proved the gender difference in allergic reactions. BALB/c mice are grouped into the negative control group (N-Ctrl), the OVA-sensitized group (P-Ctrl), the estrogenized OVA-sensitized group (E2), and three treatment groups administrating different dose of API (E2 + API/L/M/H). In vivo data indicated that API treatment significantly inhibited the enhancement of estradiol on clinical symptoms. Moreover, we found that high doses of API inhibited Th2 type humoral response and mast cell degranulation levels in vivo and in vitro. Additionally, medium, and high doses of API significantly reduced the potentiation of estradiol on ER expression, attenuated the transmission of estrogen/ER signaling, thereby inhibiting the phosphorylation of ERK1/2 and JNK1/2/3 in the MAPK. Besides, we found that API competitively bound to ER with estradiol, and showed a weak selectivity to ERβ. Overall, we identified API can be beneficial in allergic disease.

hENT1 reverses chemoresistance by regulating glycolysis in pancreatic cancer

Gemcitabine (GEM) chemotherapy, as the first-line regimen for pancreatic cancer, tends to induce drug resistance, which ultimately worsens the prognosis of patients with pancreatic cancer. Our previous study indicated a close correlation between pancreatic cancer progression and glucose metabolism, especially at the chemoresistant stage, highlighting the importance of the application of 18F-FDG PET dual-phase imaging in the early detection of pancreatic cancer. We speculate that glycolysis, participates in the development of chemoresistance in pancreatic cancer. In this article, we wanted to determine whether manipulating hENT1 expression in pancreatic cancer cells can reverse GEM chemoresistance and whether glucose transport and glycolysis are involved during this process. We found that hENT1 reversed GEM-induced drug resistance by inhibiting glycolysis and altering glucose transport mediated by HIF-1α in pancreatic cancer. Our findings also suggest that 18F-FDG PET dual-phase imaging after the 4th chemotherapy treatment can accurately identify drug-resistant pancreatic tumors and improve hENT1 reversal therapy. Our findings highlight that the dynamic observation of (retention index) RI changes from the beginning of treatment can also be helpful for evaluating the therapeutic effect.

Apigenin as an anticancer agent

Apigenin is an edible plant-derived flavonoid that has been reported as an anticancer agent in several experimental and biological studies. It exhibits cell growth arrest and apoptosis in different types of tumors such as breast, lung, liver, skin, blood, colon, prostate, pancreatic, cervical, oral, and stomach, by modulating several signaling pathways. Apigenin induces apoptosis by the activation of extrinsic caspase-dependent pathway by upregulating the mRNA expressions of caspase-3, caspase-8, and TNF-α. It induces intrinsic apoptosis pathway as evidenced by the induction of cytochrome c, Bax, and caspase-3, while caspase-8, TNF-α, and B-cell lymphoma 2 levels remained unchanged in human prostate cancer PC-3 cells. Apigenin treatment leads to significant downregulation of matrix metallopeptidases-2, -9, Snail, and Slug, suppressing invasion. The expressions of NF-κB p105/p50, PI3K, Akt, and the phosphorylation of p-Akt decreases after treatment with apigenin. However, apigenin-mediated treatment significantly reduces pluripotency marker Oct3/4 protein expression which might be associated with the downregulation of PI3K/Akt/NF-κB signaling.

A critical review on anti-angiogenic property of phytochemicals

Angiogenesis, a process involved in neovascularization, has been found to be associated with several metabolic diseases like cancer, retinopathy etc. Thus, currently, the focus on anti-angiogenic therapy for treatment and prevention of diseases has gained significant attention. Currently available Food and Drug Administration (FDA) approved drugs are targeting either vascular endothelial growth factor or it's receptor, but in the long term, these approaches were shown to cause several side effects and the chances of developing resistance to these drugs is also high. Therefore, identification of safe and cost-effective anti-angiogenic molecules is highly imperative. Over the past decades, dietary based natural compounds have been studied for their anti-angiogenic potential which provided avenues in improving the angiogenesis based therapy. In this review, major emphasis is given to the molecular mechanism behind anti-angiogenic effect of natural compounds from dietary sources.

Beta 2-microglobulin regulates amyloid precursor-like protein 2 expression and the migration of pancreatic cancer cells

Beta 2-microglobulin (β₂m) is a component of the major histocompatibility complex (MHC) class I molecule, which presents tumor antigens to T lymphocytes to trigger cancer cell destruction. Notably, β₂m has been reported as persistently expressed, rather than down regulated, in some tumor types. For renal cell and oral squamous cell carcinomas, β₂m expression has been linked to increased migratory capabilities. The migratory ability of pancreatic cancer cells contributes to their metastatic tendencies and lethal nature. Therefore, in this study, we examined the impact of β₂m on pancreatic cancer cell migration. We found that β₂m protein is amply expressed in several human pancreatic cancer cell lines (S2-013, PANC-1, and MIA PaCa-2). Reducing β₂m expression by short interfering RNA (siRNA) transfection significantly slowed the migration of the PANC-1 and S2-013 cancer cell lines, but increased the migration of the MIA PaCa-2 cell line. The amyloid precursor-like protein 2 (APLP2) has been documented as contributing to pancreatic cancer cell migration, invasiveness, and metastasis. We have previously shown that β₂m/HLA class I/peptide complexes associate with APLP2 in S2-013 cells, and in this study we also detected their association in PANC-1 cells but not MIA PaCa-2 cells. In addition, siRNA down regulation of β₂m expression diminished the expression of APLP2 in S2-013 and PANC-1 but heightened the level of APLP2 in MIA PaCa-2 cells, consistent with our migration data and co-immunoprecipitation data. Thus, our findings indicate that β₂m regulates pancreatic cancer cell migration, and furthermore suggest that APLP2 is an intermediary in this process.

Significance of 18F-Fluorodeoxyglucose (FDG) Uptake in Response to Chemoradiotherapy for Pancreatic Cancer

BACKGROUND

A metabolic shift to glycolysis is reportedly involved in radioresistance. We examined whether pretreatment ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET), which can detect enhanced glucose uptake, was able to predict the therapeutic response to chemoradiotherapy (CRT) in patients with pancreatic cancer (PC).

METHODS

Of 125 PC patients (75 unresectable and 50 borderline resectable), 37 and 26 underwent induction chemotherapy before CRT and surgical resection after CRT, respectively. FDG-PET was performed at three different institutions.

RESULTS

Of the 88 patients who underwent upfront CRT, 31 (35%), 34 (39%), and 23 (26%) showed a partial response (PR), stable disease, and progressive disease, respectively. The tumor PR rate was an independent factor associated with longer overall survival (OS) on multivariate analysis. We evaluated the optimal cut-off of maximum standardized uptake values (SUV_max) at initial diagnosis to detect the tumor PR rate at the three institutions separately. The SUV_max was independently associated with tumor response rate on multivariate analysis. In the low SUV_max group, induction chemotherapy had no significant impact on OS. In contrast, induction chemotherapy was significantly associated with longer OS in the high SUV_max group.

CONCLUSIONS

FDG-PET SUV_max was significantly associated with the therapeutic response to CRT in PC patients. Moreover, induction chemotherapy may improve the prognosis of patients with a high SUV_max tumor.

An Array of Bioactive Compounds From Australian Eucalypts and Their Relevance in Pancreatic Cancer Therapeutics

Pancreatic cancer (PC) is one of the most devastating human cancers, and despite the significant advances in the current therapeutic options, the overall survival rate for PC has remained static for the past 50 years. Plant-derived bioactive compounds play a vital role in cancer therapeutics by providing new lead compounds for future drug development. Therefore, the isolation, characterization, and identification of new bioactive compounds for the prevention and treatment of cancer continue to be an important aspect of natural product research. Many in vitro and in vivo studies published in the last few decades have established strong links between the phytochemical profile of eucalypts and anticancer activity. However, only a small number of these reports have attempted to demonstrate a relationship between the biological activity of eucalypt extracts and PC. This review focuses on potential anti-PC effects of an array of bioactive compounds present in various species of eucalypts. It also highlights the necessity for further in vitro and in vivo studies to develop a complete understanding of the potential this group of plants has for the development of potent and specific chemotherapeutic drugs for PC.

Eucalyptus microcorys leaf extract derived HPLC-fraction reduces the viability of MIA PaCa-2 cells by inducing apoptosis and arresting cell cycle

New therapeutic strategies such as the development of novel drugs and combinatorial therapies with existing chemotherapeutic agents are urgently needed to improve the clinical prognosis of pancreatic cancer. We have previously reported the antiproliferative properties of aqueous crude Eucalyptus microcorys extract against pancreatic cancer cell lines. In this study, bioassay-guided fractionation of the aqueous crude E. microcorys extract using RP-HPLC and subsequent assessment of the resultant fractions (F1-F5) for their antioxidant activity and cytotoxicity against pancreatic cancer cell lines were performed. The molecular mechanisms associated with the cytotoxicity was characterised by studying the effects of the most potent fraction-1 (F1) on apoptosis and cell cycle profiles as well as its phytochemical constituents by LC-ESI/MS/MS. F1 displayed significantly greater antioxidant activity in three different assays (p < 0.05). Moreover, F1 exhibited significantly greater antiproliferative activity (IC₅₀ = 93.11 ± 3.43 μg/mL) against MIA PaCa-2 cells compared to the other four fractions (p < 0.05). F1 induced apoptosis by regulating key apoptotic proteins- Bcl-2, Bak, Bax, cleaved PARP, procaspase-3 and cleaved caspase-3 in MIA PaCa-2 cells, suggesting the involvement of intrinsic mitochondrial apoptotic pathway and arrested cells at G2/M phase. A combination of gemcitabine and F1 exerted a greater effect on apoptosis and cell cycle arrest than F1 or gemcitabine alone (p < 0.05). LC-ESI/MS/MS revealed the tentative identities of phytochemicals present in F1 and their similarities with the phenolic compounds previously reported in Eucalyptus with antipancreatic cancer activity. Our study shows that the polyphenol and antioxidant-rich fraction of E. microcorys extract is a promising candidate for developing mono or combination therapies against pancreatic cancer.

Role of metabolism in cancer cell radioresistance and radiosensitization methods

BACKGROUND

Radioresistance is a major factor leading to the failure of radiotherapy and poor prognosis in tumor patients. Following the application of radiotherapy, the activity of various metabolic pathways considerably changes, which may result in the development of resistance to radiation.

MAIN BODY

Here, we discussed the relationships between radioresistance and mitochondrial and glucose metabolic pathways, aiming to elucidate the interplay between the tumor cell metabolism and radiotherapy resistance. In this review, we additionally summarized the potential therapeutic targets in the metabolic pathways.

SHORT CONCLUSION

The aim of this review was to provide a theoretical basis and relevant references, which may lead to the improvement of the sensitivity of radiotherapy and prolong the survival of cancer patients.

Molecular and functional evaluation of a novel HIF inhibitor, benzopyranyl 1,2,3-triazole compound

Hypoxia occurs in a variety of pathological events, including the formation of solid tumors. Hypoxia-inducible factor (HIF)-1α is stabilized under hypoxic conditions and is a key molecule in tumor growth and angiogenesis. Seeking to develop novel cancer therapeutics, we investigated small molecules from our in-house chemical libraries to target HIF-1α. We employed a dual-luciferase assay that uses a luciferase (Luc) reporter vector harboring five copies of hypoxia-responsive element (HRE) in the promoter. Under hypoxic conditions that increased Luc reporter activity by four-fold, we screened 144 different compounds, nine of which showed 30–50% inhibition of hypoxia-induced Luc reporter activity. Among these, “Compound 12, a benzopyranyl 1,2,3-triazole” was the most efficient at inhibiting the expression of HIF-1α under hypoxic conditions, reducing its expression by 80%. Under hypoxic conditions, the half maximal IC₅₀ of the compound was 24 nM in HEK-293 human embryonic kidney cells, and 2 nM in A549 human lung carcinoma cells. Under hypoxic conditions, Compound 12 increased hydroxylated HIF-1α levels and HIF-1α ubiquitination, and also dose-dependently decreased HIF-1α target gene expression as well as vascular endothelial growth factor (VEGF) secretion. Furthermore, this compound inhibited VEGF-induced in vitro angiogenesis in human umbilical vein endothelial cells (HUVECs), and in vivo, it inhibited chick chorioallantoic membrane angiogenesis. In allogaft assays, cotreatment with Compound 12 and gefitinib significantly inhibited tumor growth and angiogenesis. Compound 12 can be a novel inhibitor of HIF-1α by accelerating its degradation, and shows much potential as an anti-cancer agent through its ability to suppress tumor growth and angiogenesis.

Significance of Glucose Transporter Type 1 (GLUT-1) Expression in the Therapeutic Strategy for Pancreatic Ductal Adenocarcinoma

BACKGROUND

This study aimed to examine the prognostic relevance of glucose transporter type 1 (GLUT-1), which is a key regulator of the glucose metabolism. In particular, the study aimed to examine the association between GLUT-1 expression and the therapeutic effect of chemoradiotherapy (CRT) in pancreatic ductal adenocarcinoma (PDAC).

METHODS

Patients with PDAC were enrolled in the study. Patients with distant metastases and those who received only chemotherapy as treatment were excluded from the study. Specimens for immunohistochemical evaluations were obtained through surgical resection and endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of the primary tumor before any treatment.

RESULTS

This study included 197 patients. Of these 197 patients, 100 underwent upfront surgery, and 97 received neoadjuvant CRT (NACRT), which was performed mainly for patients with locally advanced tumors. Of the 97 patients who received NACRT, 21 later underwent surgical resection. For the patients who underwent upfront surgery, low GLUT-1 expression was an independent factor for a better prognosis. For the patients who underwent NACRT, low GLUT-1 expression was significantly associated with greater tumor size reduction, a higher resection rate, and a better prognosis. Additionally, GLUT-1 expression was significantly increased after NACRT treatment.

CONCLUSIONS

Among the patients with PDAC, those with low GLUT-1 expression in the primary tumor had a better prognosis those with high GLUT-1 expression. Moreover, the patients with low GLUT-1 expression displayed a better therapeutic response to NACRT.

Plant flavone apigenin: An emerging anticancer agent

Research in cancer chemoprevention provides convincing evidence that increased intake of vegetables and fruits may reduce the risk of several human malignancies. Phytochemicals present therein provide beneficial anti-inflammatory and antioxidant properties that serve to improve the cellular microenvironment. Compounds known as flavonoids categorized anthocyanidins, flavonols, flavanones, flavonols, flavones, and isoflavones have shown considerable promise as chemopreventive agents. Apigenin (4', 5, 7-trihydroxyflavone), a major plant flavone, possessing antioxidant, anti-inflammatory, and anticancer properties affecting several molecular and cellular targets used to treat various human diseases. Epidemiologic and case-control studies have suggested apigenin reduces the risk of certain cancers. Studies demonstrate that apigenin retain potent therapeutic properties alone and/or increases the efficacy of several chemotherapeutic drugs in combination on a variety of human cancers. Apigenin's anticancer effects could also be due to its differential effects in causing minimal toxicity to normal cells with delayed plasma clearance and slow decomposition in liver increasing the systemic bioavailability in pharmacokinetic studies. Here we discuss the anticancer role of apigenin highlighting its potential activity as a chemopreventive and therapeutic agent. We also highlight the current caveats that preclude apigenin for its use in the human trials.

Clinicopathological significance of glucose transporter protein-1 overexpression in human osteosarcoma

Although previous studies have demonstrated that Glut-1 is the predominant glucose transporter, is significantly overexpressed in various types of tumor and is correlated with poor prognosis, the potential function and clinical value of Glut-1 expression in osteosarcoma remains largely unclear. In particular, the prospective associations between Glut-1 expression levels and clinicopathological factors remains to be elucidated. In the present study, immunohistochemistry was performed to detect Glut-1 protein expression in 51 paired osteosarcoma specimens and adjacent non-cancerous tissues, and reverse transcription-quantitative polymerase chain reaction analysis was performed to examine Glut-1 mRNA expression levels in 6 pairs of these tissues. Statistical analyses were conducted to determine the associations between Glut-1 expression and various clinicopathological parameters. Glut-1 protein was revealed to be overexpressed in 38 (74.5%) osteosarcoma tissues, but only in 6 (11.8%) adjacent non-cancerous tissues. Glut-1 mRNA levels were also upregulated in osteosarcoma tissues compared with adjacent non-cancerous tissues. While there were no clear statistical relationships between Glut-1 expression and patient sex, resection, tumor location, size, T stage and adjuvant treatment, Glut-1 expression levels were significantly associated with age, tumor-node-metastasis stage, lymph node metastasis and survival. The median survival time in patients with low Glut-1 expression levels was longer than in patients with a high expression level. Glut-1 was significantly overexpressed in osteosarcoma tissues, and Glut-1 expression was associated with clinicopathological factors which upregulate the invasion and metastasis of osteosarcoma, and may be a potential predictor of survival in patients with osteosarcoma.

Strategies to Target Glucose Metabolism in Tumor Microenvironment on Cancer by Flavonoids

The imbalance between glucose metabolism and cancer cell growth in tumor microenvironment (TME), which are closely related with the occurrence and progression of cancer. Accumulating evidence has demonstrated that flavonoids exert many biological properties, including antioxidant and anticarcinogenic activities. Recently, the roles and applications of flavonoids, particularly in relation to glucose metabolism in cancers, have been highlighted. Thus, the identification of flavonoids targeting alternative glucose metabolism pathways in TME may represent an attractive approach to the more effective therapeutic strategies for cancer. In this review, we will focus on the roles of flavonoids in regulating glucose metabolism and cancer cell growth in TME, such as proliferation advantage, cell mobility, and chemoresistance to cancer, as well as modifiers of thermal sensitivity. Not only have such large-scale endeavors been useful in providing fundamental insights into natural and synthesized flavonoids that can prevent and treat cancer, but also have led to the discovery of potential targets for cancer therapy.