Resveratrol Induces Cancer Cell Apoptosis through MiR-326/PKM2-Mediated ER Stress and Mitochondrial Fission

Transcriptional regulation and post-translational modifications in the glycolytic pathway for targeted cancer therapy

Cancer cells largely rely on aerobic glycolysis or the Warburg effect to generate essential biomolecules and energy for their rapid growth. The key modulators in glycolysis including glucose transporters and enzymes, e.g. hexokinase 2, enolase 1, pyruvate kinase M2, lactate dehydrogenase A, play indispensable roles in glucose uptake, glucose consumption, ATP generation, lactate production, etc. Transcriptional regulation and post-translational modifications (PTMs) of these critical modulators are important for signal transduction and metabolic reprogramming in the glycolytic pathway, which can provide energy advantages to cancer cell growth. In this review we recapitulate the recent advances in research on glycolytic modulators of cancer cells and analyze the strategies targeting these vital modulators including small-molecule inhibitors and microRNAs (miRNAs) for targeted cancer therapy. We focus on the regulation of the glycolytic pathway at the transcription level (e.g., hypoxia-inducible factor 1, c-MYC, p53, sine oculis homeobox homolog 1, N6-methyladenosine modification) and PTMs (including phosphorylation, methylation, acetylation, ubiquitination, etc.) of the key regulators in these processes. This review will provide a comprehensive understanding of the regulation of the key modulators in the glycolytic pathway and might shed light on the targeted cancer therapy at different molecular levels.

Modified Hu-lu-ba-wan protects diabetic glomerular podocytes via promoting PKM2-mediated mitochondrial dynamic homeostasis

BACKGROUND

Mitochondrial dysfunction is implicated in the progression of diabetic kidney disease (DKD). Damaged mitochondria produce excessive reactive oxygen species (ROS) that can cause apoptosis. Mitochondrial dynamics control the quality and function of mitochondria. Targeting mitochondrial dynamics may reduce ROS-induced apoptosis and improve renal injury in DKD. Modified Hu-lu-ba-wan (MHLBW) shows distinct clinical effects on DKD patients, which are related to its role in antioxidant stress modulation. However, the relevant mechanisms of MHLBW have not been clearly explored.

PURPOSE

This study was aimed to evaluate the therapeutic effects of MHLBW on spontaneous DKD mice and clarify the potential mechanisms.

METHODS

The main components of MHLBW were identified by HPLC. Using db/db mice as DKD models, we evaluated the therapeutic effects of MHLBW on mice after an 8-week administration. We investigated the molecular mechanism of MHLBW in regulating mitochondrial dynamic homeostasis, podocyte apoptosis, and glomerular damage. After that, computational docking analysis and in vitro experiments were conducted for further mechanism verification.

RESULTS

Intragastric administration of MHLBW for 8 weeks in db/db mice significantly improved glucose metabolism, basement membrane thickening, mesangial expansion, glomerular fibrosis, and podocyte injury. MHLBW can reverse podocyte apoptosis via promoting mitochondrial dynamic homeostasis, which was related to regulating the PKM2/ PGC-1α/Opa1 pathway. Berberine (BBR), one of the components of MHLBW, exhibited preeminent affinity with PKM2 as reflected by computational docking analysis. In cultured podocytes, BBR can also prevent apoptosis by promoting PKM2-mediated mitochondrial dynamic homeostasis.

CONCLUSION

Our study demonstrates that MHLBW can treat DKD by inhibiting glomerular damage and podocyte apoptosis through positive regulation of PKM2-mediated mitochondrial dynamic homeostasis. These results may provide a potential strategy against DKD.

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

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

Recent insights into the nutritional immunomodulation of cancer-related microRNAs

Cancer is the most common cause of death worldwide, following cardiovascular diseases. Cancer is a multifactorial disease and many reasons such as physical, chemical, biological, and lifestyle-related factors. Nutrition, which is one of the various factors that play a role in the prevention, development, and treatment of many types of cancer, affects the immune system, which is characterized by disproportionate pro-inflammatory signaling in cancer. Studies investigating the molecular mechanisms of this effect have shown that foods rich in bioactive compounds, such as green tea, olive oil, turmeric, and soybean play a significant role in positively changing the expression of miRNAs involved in the regulation of genes associated with oncogenic/tumor-suppressing pathways. In addition to these foods, some diet models may change the expression of specific cancer-related miRNAs in different ways. While Mediterranean diet has been associated with anticancer effects, a high-fat diet, and a methyl-restricted diet are considered to have negative effects. This review aims to discuss the effects of specific foods called "immune foods," diet models, and bioactive components on cancer by changing the expression of miRNAs in the prevention and treatment of cancer.

Pseudolaric acid B triggers cell apoptosis by activating AMPK/JNK/DRP1/mitochondrial fission pathway in hepatocellular carcinoma

Pseudolaric acid B (PAB), a natural product isolated from the root bark of Pseudolarix kaempferi, has been reported to exert inhibitory effects in various cancers. However, the underlying mechanisms remain largely unclear. In the present study, we investigated the mechanism through which PAB exert its anticancer effects in hepatocellular carcinoma (HCC). PAB inhibited the viability of and induced apoptosis in Hepa1-6 cells in a dose-dependent manner. It disrupted mitochondrial membrane potential (MMP) and impaired ATP production. Furthermore, PAB induced phosphorylation of DRP1 at Ser616 and mitochondrial fission. Blocking DRP1 phosphorylation by Mdivi-1 inhibited mitochondrial fission and PAB-induced apoptosis. Moreover, c-Jun N-terminal kinase (JNK) was activated by PAB, and blocking JNK activity using SP600125 inhibited PAB-induced mitochondrial fission and cell apoptosis. Furthermore, PAB activated AMP-activated protein kinase (AMPK), and inhibiting AMPK by compound C attenuated PAB-stimulated JNK activation and blocked DRP1-dependent mitochondrial fission and apoptosis. Our in vivo data confirmed that PAB inhibited tumor growth and induced apoptosis in an HCC syngeneic mouse model by inducing the AMPK/JNK/DRP1/mitochondrial fission signaling pathway. Furthermore, a combination of PAB and sorafenib showed a synergistic effect in inhibiting tumor growth in vivo. Taken together, our findings highlight a potential therapeutic strategy for HCC.

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.

Cancer metabolism control by natural products: Pyruvate kinase M2 targeting therapeutics

Glycolysis is the primary source of energy for cancer growth and metastasis. The shift in metabolism from mitochondrial oxidative phosphorylation to aerobic glycolysis is called the Warburg effect. Cancer progression due to aerobic glycolysis is often associated with the activation of oncogenes or the loss of tumor suppressors. Therefore, inhibition of glycolysis is one of the effective strategies in cancer control. Pyruvate kinase M2 (PKM2) is a key glycolytic enzyme overexpressed in breast, prostate, lung, colorectal, and liver cancers. Here, we discuss published studies regarding PKM2 inhibitors from natural products that are promising drug candidates for cancer therapy. We have highlighted the potential of natural PKM2 inhibitors for various cancer types. Moreover, we encourage researchers to evaluate the combinational effects between natural and synthetic PKM2 inhibitors. Also, further high-quality studies are needed to firmly establish the clinical efficacy of natural products.

Targeting Energy Metabolism in Cancer Treatment

Cancer is the second most common cause of death worldwide after cardiovascular diseases. The development of molecular and biochemical techniques has expanded the knowledge of changes occurring in specific metabolic pathways of cancer cells. Increased aerobic glycolysis, the promotion of anaplerotic responses, and especially the dependence of cells on glutamine and fatty acid metabolism have become subjects of study. Despite many cancer treatment strategies, many patients with neoplastic diseases cannot be completely cured due to the development of resistance in cancer cells to currently used therapeutic approaches. It is now becoming a priority to develop new treatment strategies that are highly effective and have few side effects. In this review, we present the current knowledge of the enzymes involved in the different steps of glycolysis, the Krebs cycle, and the pentose phosphate pathway, and possible targeted therapies. The review also focuses on presenting the differences between cancer cells and normal cells in terms of metabolic phenotype. Knowledge of cancer cell metabolism is constantly evolving, and further research is needed to develop new strategies for anti-cancer therapies.

The Role of PKM2 in the Regulation of Mitochondrial Function: Focus on Mitochondrial Metabolism, Oxidative Stress, Dynamic, and Apoptosis. PKM2 in Mitochondrial Function

The M2 isoform of pyruvate kinase (PKM2) is one isoform of pyruvate kinase (PK). PKM2 is expressed at high levels during embryonic development and tumor progression and is subject to complex allosteric regulation. PKM2 is a special glycolytic enzyme that regulates the final step of glycolysis; the role of PKM2 in the metabolism, survival, and apoptosis of cancer cells has received increasing attention. Mitochondria are directly or indirectly involved in the regulation of energy metabolism, susceptibility to oxidative stress, and cell death; however, the role of PKM2 in mitochondrial functions remains unclear. Herein, we review the related mechanisms of the role of PKM2 in the regulation of mitochondrial functions from the aspects of metabolism, reactive oxygen species (ROS), dynamic, and apoptosis, which can be highlighted as a target for the clinical management of cardiovascular and metabolic diseases.

The role and mechanism of noncoding RNAs in regulation of metabolic reprogramming in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. Metabolic reprogramming is considered to be an important hallmark of cancer. Emerging studies have demonstrated that noncoding RNAs (ncRNAs) are closely associated with metabolic reprogramming of HCC. NcRNAs can directly regulate the expressions or functions of metabolic enzymes or indirectly regulate the metabolism of HCC cells through some vital signaling pathways. Until now, the mechanisms of HCC development and progression remain largely unclear, and understanding the regulatory mechanism of ncRNAs on metabolic reprogramming of HCC may provide an important basis for breakthrough progress in the treatment of HCC. In this review, we summarize the ncRNAs involved in regulating metabolic reprogramming of HCC. Specifically, the regulatory roles of ncRNAs in glucose, lipid and amino acid metabolism are elaborated. In addition, we discuss the molecular mechanism of ncRNAs in regulation of metabolic reprogramming and possible therapeutic strategies that target the metabolism of cancer cells by modulating the expressions of specific ncRNAs.

Resveratrol drives cancer cell senescence via enhancing p38MAPK and DLC1 expressions

Pro-senescence therapy is a recently proposed anti-cancer strategy and has been shown to effectively inhibit cancer. Resveratrol is gaining attention for its cancer preventive and suppressive properties. The mechanisms of resveratrol in cancer suppression by inducing cancer cell senescence are unclear. Our results showed that resveratrol induced cell senescence along with an increase of SA-β-Gal activity and inhibition of colony formation in breast and lung cancer cells. The underlying mechanisms were that resveratrol induced ER-stress by increasing SIRT1 to promote p38MAPK expression and by reducing NO level to up-regulate DLC1 expression, and ER-stress further resulted in DNA damage and mitochondrial dysfunction, eventually leading to cancer cell senescence. Our findings on resveratrol's induction of cancer cell senescence via activating ER-stress through the SIRT1/p38MAPK and NO/DLC1 pathways provide a solid base for its clinical application and its preventive application as a food additive.

Involvement of microRNA modifications in anticancer effects of major polyphenols from green tea, coffee, wine, and curry

Epidemiological studies have shown that consumption of green tea, coffee, wine, and curry may contribute to a reduced risk of various cancers. However, there are some cancer site-specific differences in their effects; for example, the consumption of tea or wine may reduce bladder cancer risk, whereas coffee consumption may increase the risk. Animal and cell-based experiments have been used to elucidate the anticancer mechanisms of these compounds, with reactive oxygen species (ROS)-based mechanisms emerging as likely candidates. Chlorogenic acid (CGA), curcumin (CUR), epigallocatechin gallate (EGCG), and resveratrol (RSV) can act as antioxidants that activate AMP-activated protein kinase (AMPK) to downregulate ROS, and as prooxidants to generate ROS, leading to the downregulation of NF-κB. Polyphenols can modulate miRNA (miR) expression, with these dietary polyphenols shown to downregulate tumor-promoting miR-21. CUR, EGCG, and RSV can upregulate tumor-suppressing miR-16, 34a, 145, and 200c, but downregulate tumor-promoting miR-25a. CGA, EGCG, and RSV downregulate tumor-suppressing miR-20a, 93, and 106b. The effects of miRs may combine with ROS-mediated pathways, enhancing the anticancer effects of these polyphenols. More precise analysis is needed to determine how the different modulations of miRs by polyphenols relate to the cancer site-specific differences found in epidemiological studies related to the consumption of foods containing these polyphenols.

Epigenetic Small-Molecule Modulators Targeting Metabolic Pathways in Cancer

Metabolic deregulation is a key factor in cancer progression. Epigenetic changes and metabolic rewiring are intertwined in cancer. Deregulated epigenetic modifiers cause metabolic aberrations by targeting the expression of metabolic enzymes. Conversely, metabolites and cofactors affect the expression and activity of epigenetic regulators. Small molecules are promising therapeutic approaches to target the epigenetic-metabolomic crosstalk in cancer. Here, we focus on the interplay between metabolic rewiring and epigenetic landscape in the context of tumourigenesis and highlight recent advances in the use of small-molecule drug targets for therapy.

Cynaropicrin Induces Cell Cycle Arrest and Apoptosis by Inhibiting PKM2 to Cause DNA Damage and Mitochondrial Fission in A549 Cells

Metabolic reprogramming is critical for tumorigenesis. Pyruvate kinase M2 (PKM2) is overexpressed in lung carcinoma cells and plays a critical role in the Warburg effect, making the enzyme a research hotspot for anticancer drug development. Cynaropicrin (CYN), a natural sesquiterpene lactone compound from artichoke, has received increasing consideration due to its consumable esteem and pharmacological properties. Our data reveal that CYN not only inhibited the purified PKM2 activity but also decreased the cellular PKM2 expression in A549 cells. The inhibition of PKM2 leads to the upregulation of p53 and the downregulation of the DNA repair enzyme poly (ADP-ribose) polymerase (PARP), and subsequently causes the cell cycle arrest. Additionally, CYN inhibits the interaction of PKM2 and Nrf2, resulting in the impairment of cellular antioxidant capacity, induction of oxidative stress, and mitochondrial damages. Overexpression of PKM2 attenuates the CYN-induced DNA damage, mitochondrial fission, and cell viability. Thus, targeting PKM2 provides an original mechanism for understanding the pharmacological impact of CYN and assists in the further development of CYN as an anticancer agent.

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.

Targeting pyruvate kinase muscle isoform 2 (PKM2) in cancer: What do we know so far?

Cancer is a leading cause of death globally. Cancer cell transformation is the result of intricate crosstalk between intracellular components and proteins. A characteristic feature of cancer cells is the ability to reprogram their metabolic pathways to ensure their infinite proliferative potential. Pyruvate kinase muscle isoform 2 (PKM2) is a glycolytic enzyme that plays crucial roles in cancer, apart from carrying out its metabolic roles. PKM2 is involved in all the major events associated with cancer growth. Modulation of PKM2 activity (dimer inhibition or tetramer activation) has been successful in controlling cancer. However, recent studies provide contrary evidences regarding the oncogenic functions of PKM2. Moreover, several studies have highlighted the cancerous roles of PKM1 isoform in certain contexts. The present review aims at providing the current updates regarding PKM2 targeting in cancer. Further, the review discusses the contradictory results that suggest that both the isoforms of PKM can lead to cancer growth. In conclusion, the review emphasizes revisiting the approaches to target cancer metabolism through PKM to find novel and effective targets for anticancer therapy.

Upregulation of MicroRNA-34a Sensitizes Ovarian Cancer Cells to Resveratrol by Targeting Bcl-2

PURPOSE

Resveratrol (REV), a natural compound found in red wine, exhibits antitumor activity in various cancers, including ovarian cancer (OC). However, its potential anti-tumor mechanisms in OC are not well characterized. Here, we tried to elucidate the underlying mechanisms of REV in OC cells.

MATERIALS AND METHODS

The anti-proliferative effects of REV against OC cells were measured using CCK-8 assay. Apoptosis was measured using an Annexin V-FITC/PI apoptosis detection kit. The anti-metastasis effects of REV were evaluated by invasion assay and wound healing assay. The miRNA profiles in REV-treated cells were determined by microarray assay.

RESULTS

Our results showed that REV treatment suppresses the proliferation, induces the apoptosis, and inhibits the invasion and migration of OV-90 and SKOV-3 cells. miR-34a was selected for further study due to its tumor suppressive roles in various human cancers. We found miR-34a overexpression enhanced the inhibitory effects of REV on OC cells, whereas miR-34a inhibition had the opposite effect in OC cells. In addition, we verified that BCL2, an anti-apoptotic gene, was found directly targeted by miR-34a. We also found that REV reduced the expression of Bcl-2 in OC cells. Further investigations revealed that overexpression of Bcl-2 significantly abolished the anti-tumor effects of REV on OC cells.

CONCLUSION

Overall, these results demonstrated that REV exerts anti-cancer effects on OC cells through an miR-34a/Bcl-2 axis, highlighting the therapeutic potential of REV for treatment of OC.

Oxygen sensing, mitochondrial biology and experimental therapeutics for pulmonary hypertension and cancer

The homeostatic oxygen sensing system (HOSS) optimizes systemic oxygen delivery. Specialized tissues utilize a conserved mitochondrial sensor, often involving NDUFS2 in complex I of the mitochondrial electron transport chain, as a site of pO₂-responsive production of reactive oxygen species (ROS). These ROS are converted to a diffusible signaling molecule, hydrogen peroxide (H₂O₂), by superoxide dismutase (SOD2). H₂O₂ exits the mitochondria and regulates ion channels and enzymes, altering plasma membrane potential, intracellular Ca²⁺ and Ca²⁺-sensitization and controlling acute, adaptive, responses to hypoxia that involve changes in ventilation, vascular tone and neurotransmitter release. Subversion of this O₂-sensing pathway creates a pseudohypoxic state that promotes disease progression in pulmonary arterial hypertension (PAH) and cancer. Pseudohypoxia is a state in which biochemical changes, normally associated with hypoxia, occur despite normal pO₂. Epigenetic silencing of SOD2 by DNA methylation alters H₂O₂ production, activating hypoxia-inducible factor 1α, thereby disrupting mitochondrial metabolism and dynamics, accelerating cell proliferation and inhibiting apoptosis. Other epigenetic mechanisms, including dysregulation of microRNAs (miR), increase pyruvate dehydrogenase kinase and pyruvate kinase muscle isoform 2 expression in both diseases, favoring uncoupled aerobic glycolysis. This Warburg metabolic shift also accelerates cell proliferation and impairs apoptosis. Disordered mitochondrial dynamics, usually increased mitotic fission and impaired fusion, promotes disease progression in PAH and cancer. Epigenetic upregulation of dynamin-related protein 1 (Drp1) and its binding partners, MiD49 and MiD51, contributes to the pathogenesis of PAH and cancer. Finally, dysregulation of intramitochondrial Ca²⁺, resulting from impaired mitochondrial calcium uniporter complex (MCUC) function, links abnormal mitochondrial metabolism and dynamics. MiR-mediated decreases in MCUC function reduce intramitochondrial Ca²⁺, promoting Warburg metabolism, whilst increasing cytosolic Ca²⁺, promoting fission. Epigenetically disordered mitochondrial O₂-sensing, metabolism, dynamics, and Ca²⁺ homeostasis offer new therapeutic targets for PAH and cancer. Promoting glucose oxidation, restoring the fission/fusion balance, and restoring mitochondrial calcium regulation are promising experimental therapeutic strategies.

Resveratrol Counteracts Hypoxia-Induced Gastric Cancer Invasion and EMT through Hedgehog Pathway Suppression

BACKGROUND

Gastric Cancer (GC) is one of the most malignant and lethal tumors worldwide. The hypoxic microenvironment is correlated with GC cell invasion, metastasis and Epithelial-Mesenchymal Transition (EMT). Resveratrol is a compound extracted from various plants, including grapes, berries, and some traditional Chinese medicines. Recently, the anticancer properties of resveratrol against many cancers have been reported in a range of studies. However, the exact mechanism through which resveratrol prevents GC invasion and metastasis under hypoxic conditions remains unclear.

OBJECTIVE

The objective of this study is to show to what extent resveratrol could inhibit the hypoxia-induced malignant biological behavior of GC.

METHODS

SGC-7901 cells were cultured in a consistent 3% O2 hypoxic condition or 21% O2 normal condition for 48 hours to establish an in vitro hypoxia model. Western blot and qRT-PCR were used to detect EMT markers of SGC- 7901 cells, including E-cadherin, HIF-1a, Vimentin, etc. Transwell Matrigel Invasion Assays were used to test the invasive ability of SGC-7901 cells. The siRNA targeting Gli-1 showed its role in hypoxia-induced EMT and invasion of SGC-7901 cells.

RESULTS

Resveratrol was found to significantly decrease HIF-1α protein levels induced by hypoxia in SGC-7901 cells. HIF-1α accumulation was found to promote cell proliferation, migration, and invasive capacities in addition to EMT changes through the activation of the Hedgehog pathway. These effects were found to be reversed by resveratrol.

CONCLUSION

Therefore, these data indicate that resveratrol may serve as a potential anticancer agent for the treatment of GC, even in a hypoxic tumor microenvironment.

LncRNA RPPH1 attenuates Aβ25-35-induced endoplasmic reticulum stress and apoptosis in SH-SY5Y cells via miR-326/PKM2

BACKGROUND

The durative endoplasmic reticulum stress (ERS) and subsequent apoptosis contributes to the development and progression of Alzheimer's disease (AD). MiR-326 can reduce pyruvate kinase M2 (PKM2) expression, leading to ERS. Whereas, lncRNA RPPH1 is able to increase dendritic spine density and protect hippocampal pyramidal neurons through targeting miR-326. Our study aims to investigate the regulation of lncRNA RPPH1 and miR-326/PKM2 on ERS and related apoptosis in AD.

METHODS

SH-SY5Y cells treated with Aβ25-35 were selected as an in vitro AD model. RPPH1 and miR-326 overexpression and silencing cells were established by transforming vectors. The expression of RPPH1 and miR-326 were detected by qRT-PCR. MTT, flow cytometric, intracellular calcium assay and Western blot were used to test the functions of RPPH1 and miR-326 in SH-SY5Y cell proliferation, apoptosis and ERS. Dual-luciferase assay was used to detect the interaction among RPPH1, miR-326 and PKM2.

RESULTS

RPPH1 overexpression enhanced the viability of SH-SY5Y cells, and attenuated the apoptosis of of SH-SY5Y cells. Moreover, RPPH1 overexpression down-regulated ER stress related proteins such as GRP78, CHOP and cleaved caspase-12. Mechanistically, RPPH1 directly targeted miR-326, thereby counteracting its inhibitory effect on PKM2 expression, contributing to attenuation of apoptosis and ERS induced by Aβ25-35.

CONCLUSION

Aβ25-35-induced ERS and apoptosis in SH-SY5Y cells can be attenuated by lncRNA RPPH1 through regulating miR-326/PKM2 axis. This study provided therapeutic options for AD patients.

Kaempferol Reverses Aerobic Glycolysis via miR-339-5p-Mediated PKM Alternative Splicing in Colon Cancer Cells

Colon cancer is an aggressive malignancy with very limited therapeutic approaches. The available therapeutic agents for colon cancer show strong adverse effects and poor effectiveness, indicating the urgent need to identify new therapeutic drugs for this malignancy. Kaempferol, a flavonoid found in a variety of natural foods, exhibits significant inhibitory effects on colon cancer. Here, it was found that kaempferol inhibited the proliferation of human colon cancer cells HCT116 and DLD1 in a dose-dependent manner, and the IC₅₀ values were 63.0 ± 12.9 and 98.3 ± 15.9 μM, respectively. Also, kaempferol treatment delayed G1 phase progression of cell cycle and induced apoptosis. Aerobic glycolysis is the major energy source for various tumor growths, including colon cancer. Indeed, kaempferol treatment impaired glucose consumption, which subsequently led to reduced lactic acid accumulation and ATP production. Mechanistically, kaempferol promoted the expression of miR-339-5p. Further studies identified hnRNPA1 and PTBP1 as two direct targets of miR-339-5p. By directly targeting hnRNPA1 and PTBP1, miR-339-5p reduced the expression of M2-type pyruvate kinase (PKM2) but induced that of PKM1. In conclusion, these data demonstrate that by modulating miR-339-5p-hnRNPA1/PTBP1-PKM2 axis, kaempferol inhibits glycolysis and colon cancer growth, which reveals a new explanation for the molecular mechanism underlying kaempferol anti-tumor.

Anti-Tumor Mechanisms Associated With Regulation of Non-Coding RNA by Active Ingredients of Chinese Medicine: A Review

Cancer has become the second leading cause of death worldwide; however, its complex pathogenesis remains largely unclear. Previous research has shown that cancer development and progression are closely associated with various non-coding RNAs, including long non-coding RNAs and microRNAs, which regulate gene expression. Target gene abnormalities are regulated and engaged in the complex mechanism underlying tumor formation, thereby controlling apoptosis, invasion, and migration of tumor cells and providing potentially effective targets for the treatment of malignant tumors. Chemotherapy is a commonly used therapeutic strategy for cancer; however, its effectiveness is limited by general toxicity and tumor cell drug resistance. Therefore, increasing attention has been paid to developing new cancer treatment modalities using traditional Chinese medicines, which exert regulatory effects on multiple components, targets, and pathways. Several active ingredients in Chinese medicine, including ginsenoside, baicalin, and matrine have been found to regulate ncRNA expression levels, thus, exerting anti-tumor effects. This review summarizes the scientific progress made regarding the anti-tumor mechanisms elicited by various active ingredients of Chinese medicine in regulating non-coding RNAs, to provide a theoretical foundation for treating tumors using traditional Chinese medicine.

Role of Resveratrol in Modulating microRNAs in Human Diseases: From Cancer to Inflammatory Disorder

Cancer and inflammatory disorders are two important public health issues worldwide with significant socio.economic impacts. Despite several efforts, the current therapeutic platforms are associated with severe limitations. Therefore, developing new therapeutic strategies for the treatment of these diseases is a top priority. Besides current therapies, the utilization of natural compounds has emerged as a new horizon for the treatment of cancer and inflammatory disorders as well. Such natural compounds could be used either alone or in combination with the standard cancer therapeutic modalities such as chemotherapy, radiotherapy, and immunotherapy. Resveratrol is a polyphenolic compound that is found in grapes as well as other foods. It has been found that this medicinal agent displays a wide pharmacological spectrum, including anti-cancer, anti-inflammatory, anti-microbial, and antioxidant activities. Recently, clinical and pre-clinical studies have highlighted the anti-cancer and anti-inflammatory effects of resveratrol. Increasing evidence revealed that resveratrol exerts its therapeutic effects by targeting various cellular and molecular mechanisms. Among cellular and molecular targets that are modulated by resveratrol, microRNAs (miRNAs) have appeared as key targets. MiRNAs are short non-coding RNAs that act as epigenetic regulators. These molecules are involved in many processes that are involved in the initiation and progression of cancer and inflammatory disorders. Herein, we summarized various miRNAs that are directly/indirectly influenced by resveratrol in cancer and inflammatory disorders.

The Role of PKM2 in Metabolic Reprogramming: Insights into the Regulatory Roles of Non-Coding RNAs

Pyruvate kinase is a key regulator in glycolysis through the conversion of phosphoenolpyruvate (PEP) into pyruvate. Pyruvate kinase exists in various isoforms that can exhibit diverse biological functions and outcomes. The pyruvate kinase isoenzyme type M2 (PKM2) controls cell progression and survival through the regulation of key signaling pathways. In cancer cells, the dimer form of PKM2 predominates and plays an integral role in cancer metabolism. This predominance of the inactive dimeric form promotes the accumulation of phosphometabolites, allowing cancer cells to engage in high levels of synthetic processing to enhance their proliferative capacity. PKM2 has been recognized for its role in regulating gene expression and transcription factors critical for health and disease. This role enables PKM2 to exert profound regulatory effects that promote cancer cell metabolism, proliferation, and migration. In addition to its role in cancer, PKM2 regulates aspects essential to cellular homeostasis in non-cancer tissues and, in some cases, promotes tissue-specific pathways in health and diseases. In pursuit of understanding the diverse tissue-specific roles of PKM2, investigations targeting tissues such as the kidney, liver, adipose, and pancreas have been conducted. Findings from these studies enhance our understanding of PKM2 functions in various diseases beyond cancer. Therefore, there is substantial interest in PKM2 modulation as a potential therapeutic target for the treatment of multiple conditions. Indeed, a vast plethora of research has focused on identifying therapeutic strategies for targeting PKM2. Recently, targeting PKM2 through its regulatory microRNAs, long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) has gathered increasing interest. Thus, the goal of this review is to highlight recent advancements in PKM2 research, with a focus on PKM2 regulatory microRNAs and lncRNAs and their subsequent physiological significance.

Resveratrol's Anti-Cancer Effects through the Modulation of Tumor Glucose Metabolism

Simple Summary

The prevention and treatment of cancer is an ongoing medical challenge. In the context of personalized medicine, the well-studied polyphenol resveratrol could complement classical tumor therapy. It may affect key processes such as inflammation, angiogenesis, proliferation, metastasis, glucose metabolism, and apoptosis in various cancers because resveratrol acts as a multi-targeting agent by modulating multiple signal transduction pathways. This review article focuses on resveratrol’s ability to modify tumor glucose metabolism and its associated therapeutic capacity. Resveratrol reduces glucose uptake and glycolysis by affecting Glut1, PFK1, HIF-1α, ROS, PDH, and the CamKKB/AMPK pathway. It also inhibits cell growth, invasion, and proliferation by targeting NF-kB, Sirt1, Sirt3, LDH, PI-3K, mTOR, PKM2, R5P, G6PD, TKT, talin, and PGAM. In addition, resveratrol induces apoptosis by targeting integrin, p53, LDH, and FAK. In conclusion, resveratrol has many potentials to intervene in tumor processes if bioavailability can be increased and this natural compound can be used selectively.

Abstract

Tumor cells develop several metabolic reprogramming strategies, such as increased glucose uptake and utilization via aerobic glycolysis and fermentation of glucose to lactate; these lead to a low pH environment in which the cancer cells thrive and evade apoptosis. These characteristics of tumor cells are known as the Warburg effect. Adaptive metabolic alterations in cancer cells can be attributed to mutations in key metabolic enzymes and transcription factors. The features of the Warburg phenotype may serve as promising markers for the early detection and treatment of tumors. Besides, the glycolytic process of tumors is reversible and could represent a therapeutic target. So-called mono-target therapies are often unsafe and ineffective, and have a high prevalence of recurrence. Their success is hindered by the ability of tumor cells to simultaneously develop multiple chemoresistance pathways. Therefore, agents that modify several cellular targets, such as energy restriction to target tumor cells specifically, have therapeutic potential. Resveratrol, a natural active polyphenol found in grapes and red wine and used in many traditional medicines, is known for its ability to target multiple components of signaling pathways in tumors, leading to the suppression of cell proliferation, activation of apoptosis, and regression in tumor growth. Here, we describe current knowledge on the various mechanisms by which resveratrol modulates glucose metabolism, its potential as an imitator of caloric restriction, and its therapeutic capacity in tumors.

Multi-omics reveals the anticancer mechanism of asparagus saponin-asparanin A on endometrial cancer Ishikawa cells

Multi-omics reveals that AA not only induced apoptosis, but also triggered autophagy in Ishikawa cells through ER stress and DNA damage-related pathways.

Resveratrol-induced apoptosis is associated with regulating the miR-492/CD147 pathway in malignant melanoma cells

Resveratrol (RES) as a natural phytoalexin has anti-tumor effects on various cancers through its pro-apoptotic activities. Our aim was to determine that RES induces apoptosis in melanoma cells by regulating miR-492 resulting in decreased CD147 expression. We treated A375 and SK-MEL-28 melanoma cells via RES at different concentrations and time-points. The results have shown that the inhibition rate of A375 and SK-MEL-28 was significantly increased after RES treatment. Subsequently, we investigated cell apoptosis by flow cytometry, as well as detected apoptotic-associated proteins including PARP, Caspase-3, Bcl-2, and Bax by western blotting. Meanwhile, the expression of miR-492 and CD147 was analyzed. We found that RES remarkably induces apoptosis in melanoma cells, along with an upregulation of miR-492 and the inhibition of CD147 expression. Furthermore, the detection of luciferase reporter activity confirmed that miR-492 could target CD147 mRNA, and transfected with mimic miR-492 in cells reduced CD147 expression. We also performed the rescued experiment by using a miR-492 inhibitor in melanoma cells. The results showed that the ability of induced apoptosis by RES in melanoma cells was to be attenuated via inhibiting miR-492 expression resulting in CD147 augment. Finally, we determined that the effect of RES-induced apoptosis in melanoma cells is associated with, at least in part, its ability to regulate the miR-492/CD147 pathway.

The Regulatory Mechanisms of Dynamin-Related Protein 1 in Tumor Development and Therapy

Background: Various types of tumors are likely to acquire drug resistance over time. Hence, the development of novel therapies to overcome drug resistance is critical. Studies have demonstrated that drug resistance is closely associated with the dynamic regulation of mitochondria in tumor cells. The dynamin-related protein 1 (Drp1) is involved in the regulation of mitochondrial fission and plays an important role in maintaining mitochondrial morphology, function, and distribution. It is a key protein in mitochondrial quality control. Drp1 is a GTPase localized to the cytoplasm and is a potential target in cancer therapy. A variety of drugs targeting Drp1 have shown great promise in reducing the viability and proliferation of cancer cells. The dynamic regulation of Drp1-mediated mitochondria is closely associated with tumor development, and treatment. Aim: In this article, the authors reviewed the occurrence and progression of mitochondrial fission regulated by Drp1, and its influence on cell cycle, autophagy, apoptosis, migration, invasion, the molecular mechanism of tumor stemness, and metabolic reprogramming. Targeted inhibition of Drp1 and mitochondrial fission could reduce or prevent tumor occurrence and progression in a variety of cancers. Drp1 inhibitors could reduce tumor stemness and enhance tumor sensitivity to chemotherapeutic drugs. Conclusion: Research into identifying compounds that could specifically target Drp1 will be valuable for overcoming drug resistance in tumors.

A Licorice Roots Extract Induces Apoptosis and Cell Cycle Arrest and Improves Metabolism via Regulating MiRNAs in Liver Cancer Cells

Targeting altered metabolism in cancer provides a promising preventive and therapeutic approach. Natural products interplay between gene expression and metabolism either by targeting altered metabolic enzymes and/or affecting the regulating miRNAs. Licorice is a widely known product used as flavoring agent. Glycyrrhizin and other metabolites were reported to exert several metabolic benefits. Here, we investigated the effect of licorice roots extract on some metabolic pathways and their regulating miRNAs in hepatocellular carcinoma cells. Our data showed various beneficial effects of licorice roots extract including induction of apoptosis and cell cycle arrest. Second, upregulating tumor suppressor miRNAs; let7a-3p, miR-34c-5p, miR-122-5p, miR-126-3p, miR195-5p, miR-199a-5p, miR-206, and miR-326-5p. Third, inhibiting HIF1α, PI3K and C-Myc and activating AMPK and p53. Fourth, inhibiting enzymes of glycolysis; HK-2, LDH-A and PK-M2; pentose phosphate pathway; G6PD and glutaminolysis; glutaminase. However, such an extract upregulated oncogenic miRNAs; miR-21, miR-221, and miR-222. Although the present data highlights the ability of licorice roots extract to enhance apoptosis and cell cycle arrest and correct altered metabolism, it warns against its unfavorable effects, hence, its use for prevention and therapy should proceed with caution. Further experiments are required to investigate whether a specific bioactive ingredient is responsible for upregulating the oncogenic miRNAs.

Natural products and phytochemical nanoformulations targeting mitochondria in oncotherapy: an updated review on resveratrol

Mitochondria are intracellular organelles with two distinct membranes, known as an outer mitochondrial membrane and inner cell membrane. Originally, mitochondria have been derived from bacteria. The main function of mitochondria is the production of ATP. However, this important organelle indirectly protects cells by consuming oxygen in the route of energy generation. It has been found that mitochondria are actively involved in the induction of the intrinsic pathways of apoptosis. So, there have been efforts to sustain mitochondrial homeostasis and inhibit its dysfunction. Notably, due to the potential role of mitochondria in the stimulation of apoptosis, this organelle is a promising target in cancer therapy. Resveratrol is a non-flavonoid polyphenol that exhibits significant pharmacological effects such as antioxidant, anti-diabetic, anti-inflammatory and anti-tumor. The anti-tumor activity of resveratrol may be a consequence of its effect on mitochondria. Multiple studies have investigated the relationship between resveratrol and mitochondria, and it has been demonstrated that resveratrol is able to significantly enhance the concentration of reactive oxygen species, leading to the mitochondrial dysfunction and consequently, apoptosis induction. A number of signaling pathways such as sirtuin and NF-κB may contribute to the mitochondrial-mediated apoptosis by resveratrol. Besides, resveratrol shifts cellular metabolism from glycolysis into mitochondrial respiration to induce cellular death in cancer cells. In the present review, we discuss the possible interactions between resveratrol and mitochondria, and its potential application in cancer therapy.

Mitochondrial Dysfunction at the Center of Cancer Therapy

Significance: Mitochondria undergo constant morphological changes through fusion, fission, and mitophagy. As the key organelle in cells, mitochondria are responsible for numerous essential cellular functions such as metabolism, regulation of calcium (Ca²⁺), generation of reactive oxygen species, and initiation of apoptosis. Unsurprisingly, mitochondrial dysfunctions underlie many pathologies including cancer. Recent Advances: Currently, the gold standard for cancer treatment is chemotherapy, radiation, and surgery. However, the efficacy of these treatments varies across different cancer cells. It has been suggested that mitochondria may be at the center of these diverse responses. In the past decade, significant advances have been made in understanding distinct types of mitochondrial dysfunctions in cancer. Through investigations of underlying mechanisms, more effective treatment options are developed. Critical Issues: We summarize various mitochondria dysfunctions in cancer progression that have led to the development of therapeutic options. Current mitochondrial-targeted therapies and challenges are discussed. Future Directions: To address the "root" of cancer, utilization of mitochondrial-targeted therapy to target cancer stem cells may be valuable. Investigation of other areas such as mitochondrial trafficking may offer new insights into cancer therapy. Moreover, common antibiotics could be explored as mitocans, and synthetic lethality screens can be utilized to overcome the plasticity of cancer cells.

PKM2 regulates angiogenesis of VR-EPCs through modulating glycolysis, mitochondrial fission, and fusion

Vascular resident endothelial progenitor cells (VR-EPCs) have a certain ability to differentiate into endothelial cells (ECs) and participate in the process of angiogenesis. Glycolysis and mitochondrial fission and fusion play a pivotal role in angiogenesis. Pyruvate kinase muscle isoenzyme 2 (PKM2), which mediates energy metabolism and mitochondrial morphology, is regarded as the focus of VR-EPCs angiogenesis in our study. VR-EPCs were isolated from the hearts of 12-weeks-old Sprague-Dawley rats. The role of PKM2 on angiogenesis was evaluated by tube formation assay, wound healing assay, transwell assay, and chick chorioallantoic membrane assay. Western blot analysis, flow cytometry, mitochondrial membrane potential detection, reactive oxygen species (ROS) detection, immunofluorescence staining, and quantitative real-time polymerase chain reaction were used to investigate the potential mechanism of PKM2 for regulating VR-EPCs angiogenesis. We explored the function of PKM2 on the angiogenesis of VR-EPCs. DASA-58 (the activator of PKM2) promoted VR-EPCs proliferation and PKM2 activity, it also could promote angiogenic differentiation. At the same time, DASA-58 significantly enhanced glycolysis, mitochondrial fusion, slightly increased mitochondrial membrane potential, and maintained ROS at a low level. C3k, an inhibitor of PKM2, inhibited PKM2 activity, expression of angiogenesis-related genes and tube formation. Besides, C3k drastically reduced glycolysis and mitochondrial membrane potential while significantly promoting mitochondrial fission and ROS level. Activation of PKM2 could promote VR-EPCs angiogenesis through modulating glycolysis, mitochondrial fission and fusion. By contrast, PKM2 inhibitor has opposite effects.

Gold nano-particles (AuNPs) carrying miR-326 targets PDK1/AKT/c-myc axis in hepatocellular carcinoma

Abnormal expression of microRNAs (miRNAs) contributes to tumour growth and invasion. MiR-326 expression often down-regulates in several kinds of cancer and low expression of miR-326 is linked with poor prognosis in cancer patients. In the present study, we aimed to explore the modulatory mechanism of miR-326 in hepatocellular carcinoma (HCC). miR-326 expression was significantly decreased in HCC cell lines and tissues. miR-326 decreased HCC cell growth by affecting cell-cycle progression and by promoting apoptosis. In addition, miR-326 inhibited HCC cell invasion by decreasing the EMT phenotype. We found that miR-326 functioned as a tumour suppressor by repressing its down-stream target PDK1. C-myc contributed to miR-326 down-regulation through binding at its promoter and inhibited its expression. Based on these results, we conducted a therapeutic experiment by using gold nano-particles (AuNPs) carrying miR-326. Restoration of miR-326 reduced tumour growth in vivo. Our findings suggest that miR-326 may be a candidate prognostic biomarker and a target for new therapies in HCC patients.

Modulation of Multiple Signaling Pathways of the Plant-Derived Natural Products in Cancer

Natural compounds are highly effective anticancer chemotherapeutic agents, and the targets of plant-derived anticancer agents have been widely reported. In this review, we focus on the main signaling pathways of apoptosis, proliferation, invasion, and metastasis that are regulated by polyphenols, alkaloids, saponins, and polysaccharides. Alkaloids primarily affect apoptosis-related pathways, while polysaccharides primarily target pathways related to proliferation, invasion, and metastasis. Other compounds, such as flavonoids and saponins, affect all of these aspects. The association between compound structures and signaling pathways may play a critical role in drug discovery.

Glut 1 in Cancer Cells and the Inhibitory Action of Resveratrol as A Potential Therapeutic Strategy

An important hallmark in cancer cells is the increase in glucose uptake. GLUT1 is an important target in cancer treatment because cancer cells upregulate GLUT1, a membrane protein that facilitates the basal uptake of glucose in most cell types, to ensure the flux of sugar into metabolic pathways. The dysregulation of GLUT1 is associated with numerous disorders, including cancer and metabolic diseases. There are natural products emerging as a source for inhibitors of glucose uptake, and resveratrol is a molecule of natural origin with many properties that acts as antioxidant and antiproliferative in malignant cells. In the present review, we discuss how GLUT1 is involved in the general scheme of cancer cell metabolism, the mechanism of glucose transport, and the importance of GLUT1 structure to understand the inhibition process. Then, we review the current state-of-the-art of resveratrol and other natural products as GLUT1 inhibitors, focusing on those directed at treating different types of cancer. Targeting GLUT1 activity is a promising strategy for the development of drugs aimed at treating neoplastic growth.

Effects of Piceatannol and Resveratrol on Sirtuins and Hepatic Inflammation in High-Fat Diet-Fed Mice

Piceatannol (PIC) is a natural hydroxylated analog of resveratrol (RSV) and considered as a potential metabolic regulator. The purpose of this study was to compare the effects of PIC and RSV on parameters affecting inflammation, oxidative stress, and sirtuins (Sirt). Male C57BL/6J mice, 20 weeks old, were assigned to the following groups; (1) lean control, (2) high-fat diet control (HF), (3) HF_PIC, and (4) HF_RSV. Oral administration of PIC and RSV (10 mg/kg/day) for 4 weeks improved glucose control as shown by decreasing levels of area under the curve (AUC) during the oral glucose tolerance test compared with HF group. PIC improved glycemic control by increasing hepatic levels of insulin receptor and AMP-activated protein kinase. PIC increased the levels of Sirt1, Sirt3, and Sirt6 and also increased two downstream targets of Sirt, peroxisome proliferator-activated receptor gamma coactivator 1-alpha and forkhead box O1, in the liver. The inflammatory markers, interleukin (IL)-1 and IL-6, in the liver were downregulated by RSV treatment. Exposure to PIC and RSV significantly lowered hepatic levels of tumor necrosis factor-alpha. However, PIC and RSV treatments showed minimal effects on hepatic markers of oxidative stress. The levels of antioxidant enzyme, NAD(P)H:quinone oxidoreductase 1 (NQO1), were only increased in livers of RSV-treated mice compared with HF control mice. In conclusion, PIC was superior to an equal concentration of RSV in the regulation of Sirt and its downstream targets as well as insulin signaling-related parameters, while RSV potentially suppressed levels of proinflammatory markers and increased NQO1 protein levels.

MicroRNA-Mediated Health-Promoting Effects of Phytochemicals

Phytochemicals are known to benefit human health by modulating various cellular processes, including cell proliferation, apoptosis, and inflammation. Due to the potential use of phytochemicals as therapeutic agents against human diseases such as cancer, studies are ongoing to elucidate the molecular mechanisms by which phytochemicals affect cellular functions. It has recently been shown that phytochemicals may regulate the expression of microRNAs (miRNAs). MiRNAs are responsible for the fine-tuning of gene expression by controlling the expression of their target mRNAs in both normal and pathological cells. This review summarizes the recent findings regarding phytochemicals that modulate miRNA expression and promote human health by exerting anticancer, photoprotective, and anti-hepatosteatosis effects. Identifying miRNAs modulated by phytochemicals and understanding the regulatory mechanisms mediated by their target mRNAs will facilitate the efforts to maximize the therapeutic benefits of phytochemicals.

Emergence of MicroRNAs as Key Players in Cancer Cell Metabolism

BACKGROUND

Metabolic reprogramming is a hallmark of cancer. MicroRNAs (miRNAs) have been found to regulate cancer metabolism by regulating genes involved in metabolic pathways. Understanding this layer of complexity could lead to the development of novel therapeutic approaches.

CONTENT

miRNAs are noncoding RNAs that have been implicated as master regulators of gene expression. Studies have revealed the role of miRNAs in the metabolic reprogramming of tumor cells, with several miRNAs both positively and negatively regulating multiple metabolic genes. The tricarboxylic acid (TCA) cycle, aerobic glycolysis, de novo fatty acid synthesis, and altered autophagy allow tumor cells to survive under adverse conditions. In addition, major signaling molecules, hypoxia-inducible factor, phosphatidylinositol-3 kinase/protein kinase B/mammalian target of rapamycin/phosphatase and tensin homolog, and insulin signaling pathways facilitate metabolic adaptation in tumor cells and are all regulated by miRNAs. Accumulating evidence suggests that miRNA mimics or inhibitors could be used to modulate the activity of miRNAs that drive tumor progression via altering their metabolism. Currently, several clinical trials investigating the role of miRNA-based therapy for cancer have been launched that may lead to novel therapeutic interventions in the future.

SUMMARY

In this review, we summarize cancer-related metabolic pathways, including glycolysis, TCA cycle, pentose phosphate pathway, fatty acid metabolism, amino acid metabolism, and other metabolism-related oncogenic signaling pathways, and their regulation by miRNAs that are known to lead to tumorigenesis. Further, we discuss the current state of miRNA therapeutics in the clinic and their future potential.

Mitochondria in Neuroprotection by Phytochemicals: Bioactive Polyphenols Modulate Mitochondrial Apoptosis System, Function and Structure

In aging and neurodegenerative diseases, loss of distinct type of neurons characterizes disease-specific pathological and clinical features, and mitochondria play a pivotal role in neuronal survival and death. Mitochondria are now considered as the organelle to modulate cellular signal pathways and functions, not only to produce energy and reactive oxygen species. Oxidative stress, deficit of neurotrophic factors, and multiple other factors impair mitochondrial function and induce cell death. Multi-functional plant polyphenols, major groups of phytochemicals, are proposed as one of most promising mitochondria-targeting medicine to preserve the activity and structure of mitochondria and neurons. Polyphenols can scavenge reactive oxygen and nitrogen species and activate redox-responsible transcription factors to regulate expression of genes, coding antioxidants, anti-apoptotic Bcl-2 protein family, and pro-survival neurotrophic factors. In mitochondria, polyphenols can directly regulate the mitochondrial apoptosis system either in preventing or promoting way. Polyphenols also modulate mitochondrial biogenesis, dynamics (fission and fusion), and autophagic degradation to keep the quality and number. This review presents the role of polyphenols in regulation of mitochondrial redox state, death signal system, and homeostasis. The dualistic redox properties of polyphenols are associated with controversial regulation of mitochondrial apoptosis system involved in the neuroprotective and anti-carcinogenic functions. Mitochondria-targeted phytochemical derivatives were synthesized based on the phenolic structure to develop a novel series of neuroprotective and anticancer compounds, which promote the bioavailability and effectiveness. Phytochemicals have shown the multiple beneficial effects in mitochondria, but further investigation is required for the clinical application.

Noncoding RNAs as Molecular Targets of Resveratrol Underlying Its Anticancer Effects

Cancer is a significant disease burden worldwide. Chemotherapy is the mainstay of cancer treatment. Clinically used chemotherapeutic agents may elicit severe side effects. Remarkably, most of cancer cells develop chemoresistance after a period of treatment. Therefore, it is imperative to seek more effective agents without side effects. In recent years, increasing research efforts have attempted to identify natural agents that may be used alone or in combination with traditional therapeutics for cancer management. Resveratrol is a natural polyphenolic phytoalexin that can be found in various foods including blueberries, peanuts, and red wine. As a natural food ingredient, resveratrol possesses antioxidant, anti-inflammatory, and cardioprotective properties. Moreover, resveratrol exhibited promising effects in suppressing the initiation and progression of cancers. Noncoding RNAs (ncRNAs) have been universally accepted as vital regulators in cancer pathogenesis. The modulation of miRNAs and lncRNAs by resveratrol has been described. Thus, the mechanism involving the domination of ncRNA function is one of the keys to understand the anticancer effects of resveratrol. In this review, we focus on the antagonistic effects of resveratrol on cancer progression through regulation of miRNAs and lncRNAs. We also discuss the potential application of resveratrol in cancer management.

Alkaloids from nux vomica suppresses colon cancer cell growth through Wnt/β-catenin signaling pathway

Brucine and Strychnine are alkaloids isolated from the seeds of Strychnos nux vomica L., which have long been used as a traditional medicine for the treatment of tumor. However, the effect of Brucine and Strychnine on colorectal cancer (CRC) and the underlying molecular mechanism remain unclear. In the present study, Brucine and Strychnine displayed profound inhibitory effects on the growth of human colon cancer cells. The results of flow cytometric analysis demonstrated that the two alkaloids induced cellular apoptosis. Moreover, the growth of DLD1 xenografted tumors in nude mice was significantly suppressed in the Brucine or Strychnine treated group. Mechanistically, the Wnt/β-catenin is involved in this phenomenon, which is characterized by significantly increased expression of DKK1 and APC, whereas decreased expression of β-catenin, c-Myc, and p-LRP6 in CRC cells as well as tumor tissues. Collectively, Brucine and Strychnine have targeted inhibition for colon cancer proliferation both in vitro and in vivo, and it is valuable for future exploitation and utilization as an antitumor agent of CRC.

Baicalin induced colon cancer cells apoptosis through miR-217/DKK1-mediated inhibition of Wnt signaling pathway

To analyze the anti-tumor mechanism of Baicalin in human colon cancer. The MTT assay and colony formation assay demonstrated that Baicalin treatment inhibits the proliferation of DLD1 and HCT-116 cells. The apoptosis rates were induced upon Baicalin treatment and which was determined by FACS. The qPCR and western blot analysis showed that Baicalin promotes expression of DKK1 (Dickkopf), an important antagonist of Wnt signaling pathway, thereby reduces the expression of its downstream protein β-catenin and c-Myc. Reduction of DKK1 expression by siRNA attenuates β-catenin and c-Myc expression. microRNA-217 (miR-217) is decreased upon Baicalin treatment. Moreover, DKK1 is identified as the direct downstream target gene of miR-217 through the dual-luciferase reporter assay. miR-217/DKK1-mediated inhibition of Wnt signaling pathway participate in apoptosis induced by Baicalin.

Metabolic reprogramming results in abnormal glycolysis in gastric cancer: a review

The Warburg effect in tumor cells involves the uptake of high levels of glucose, enhanced glycolysis, and the metabolism of pyruvate to lactic acid rather than oxidative phos-phorylation to generate energy under aerobic conditions. This effect is closely related to the occurrence, invasion, metastasis, drug resistance, and poor prognosis of gastric cancer (GC). Current research has further demonstrated that the Warburg effect in GC cells is not only mediated by the glycolysis pathway, but also includes roles for mitochondria, noncoding RNAs, and other proteins that do not directly regulate metabolism. As a result, changes in the glycolysis pathway not only lead to abnormal glucose metabolism, but they also affect mitochondrial functions, cellular processes such as apoptosis and cell cycle regulation, and the metabolism of lipids and amino acids. In this review, we discuss metabolic reprogramming in GC based on glycolysis, a possible link between glucose metabolism, lipid metabolism, and amino acid metabolism, and we clarify the role of mitochondria. We also examine recent studies of metabolic inhibitors in GC.

Resveratrol induces apoptosis in human melanoma cell through negatively regulating Erk/PKM2/Bcl-2 axis

Background

Resveratrol is known as a natural phytoalexin found in grapes and wine, which has significant antitumor activity under in vitro and in vivo conditions. In recent years, great progress has been made in understanding the underlying mechanisms of resveratrol in inducing cellular apoptosis of melanoma cells. Our previous study has shown that the apoptosis regulation of resveratrol in melanoma cells was independent of activation of classical apoptosis-related protein p53.

Materials and methods

MTT assay and 5-bromo-2′-deoxyuridine staining assay were used to analyze cell viability and proliferation. Immunofluorescence analysis of γ-H2AX was employed to clarify DNA damages. Annexin V–propidine iodide/fluorescein isothiocyanate assay was performed to evaluate the cell apoptosis. The mechanisms underlying the activation of M2-type pyruvate kinase (PKM2) by Erk1/2 to stabilize and maintain Bcl-2 signaling was investigated by subcellular fractionation analyses, immunofluorescence analysis, co-immunoprecipitation assay, ubiquitination assay, and glutathione S-transferase pull-down assay.

Results

In the present study, we found that resveratrol dramatically inhibited melanoma cell proliferation and induced cell apoptosis through upregulation of p53 in a concentration-dependent manner. Conversely, p53 downregulation by short hairpin RNA couldn’t rescue resveratrol-induced cell proliferation inhibition or apoptosis enlargement. Additionally, we found that resveratrol downregulated antiapoptotic protein Bcl-2 and activated Bax in the protein levels by promoting Bcl-2 degradation and cytochrome c release. Moreover, we discovered that PKM2, had a key role in cell apoptosis triggered by resveratrol through interacting with Bcl-2. Based on these results, we overexpressed PKM2 in melanoma cells and found that this prevented resveratrol-induced apoptosis by stabilizing the protein level of Bcl-2.

Conclusion

Taken together, our results provided a novel mechanism accounting for the apoptosis induction of resveratrol in melanoma cells and suggested that downregulating Erk/PKM2/Bcl-2 axis appears to be a new approach for the prevention or treatment of melanoma.

Dauricine upregulates the chemosensitivity of hepatocellular carcinoma cells: Role of repressing glycolysis via miR-199a:HK2/PKM2 modulation

Dauricine (Dau) is a natural alkaloid exhibiting anti-proliferative activity against several different types of malignant cell. However, effects of Dau on hepatocellular carcinoma (HCC) cells and the underlying molecular mechanisms have remained to be fully elucidated. In this study, we found that Dau elevated the sensitivities of HCC cells to chemotherapeutic reagents, including cisplatin, sorafenib, and isoliensinine. Moreover, Dau promoted apoptosis of HCC cells triggered by these chemotherapeutic reagents. Consistently, in a xenograft mouse model, Dau sensitized HCC cells to sorafenib. In HCC cells, Dau dose-dependently inhibited glucose glycolysis and increased oxidative phosphorylation. Mechanistically, Dau downregulated the expression of hexokinase 2 (HK2) and pyruvate kinase M2 (PKM2). HK2 and PKM2 can be directly targeted by miR-199a. Dau dose-dependently increased miR-199a expression in HCC cells. Transfection of anti-miR-199a abrogated Dau-mediated suppression of HK2 and PKM2. Dau-induced metabolic shift was thereby severely crippled by anti-miR-199a. In addition, the incremental activity of Dau on sorafenib sensitivity of HCC cells was diminished in response to the transfection of anti-miR-199a. Taken together, our findings provided novel insights into the impact of Dau on HCC cells and supported considering Dau as an adjuvant reagent in the clinical treatment of HCC.