Integration of metabolomics, transcriptomics, and microRNA expression profiling reveals a miR-143-HK2-glucose network underlying zinc-deficiency-associated esophageal neoplasia

Zinc Deficiency as a General Feature of Cancer: a Review of the Literature

Trace elements are minerals that are present in very low concentrations in the human body and yet are crucial for a wide range of physiological functions. Zinc, the second most abundant trace element, is obtained primarily from the diet. After being taken up in the intestine, zinc is distributed to various target organs, where it plays key roles in processes such as immunity, protein folding, apoptosis, and antioxidant activity. Given the important role of zinc in a wide range of enzymatic reactions and physiological processes, zinc deficiency has been identified in a variety of diseases, notably cancer. In recent years, multiple meta-analyses and reviews looking at zinc levels in individual cancer types have been published, as have a plethora of primary studies demonstrating a link between low zinc levels and specific types of cancer. In this review, we summarize recent evidence implicating low zinc concentrations in serum or tissues as a characteristic in a wide range of cancers. We also discuss preliminary findings indicating that zinc level measurement could ultimately become a useful clinical tool for cancer diagnosis and predicting outcomes in patients with cancer. Finally, we suggest future directions for further elucidating the role of zinc deficiency in cancer development and progression.

Shikonin reverses cancer-associated fibroblast-induced gemcitabine resistance in pancreatic cancer cells by suppressing monocarboxylate transporter 4-mediated reverse Warburg effect

BACKGROUND

Gemcitabine is a first-line chemotherapeutic agent for pancreatic cancer (PC); however, most patients who receive adjuvant gemcitabine rapidly develop resistance and recurrence. Cancer-associated fibroblasts (CAFs) are a crucial component of the tumor stroma that contribute to gemcitabine-resistance. There is thus an urgent need to find a novel therapeutic strategy to improve the efficacy of gemcitabine in PC cells under CAF-stimulation.

PURPOSE

To investigate if shikonin potentiates the therapeutic effects of gemcitabine in PC cells with CAF-induced drug resistance.

METHODS

PC cell-stimulated fibroblasts or primary CAFs derived from PC tissue were co-cultured with PC cells to evaluate the ability of shikonin to improve the chemotherapeutic effects of gemcitabine in vitro and in vivo. Glucose uptake assay, ATP content analysis, lactate measurement, real-time PCR, immunofluorescence staining, western blot, and plasmid transfection were used to investigate the underlying mechanism.

RESULTS

CAFs were innately resistant to gemcitabine, but shikonin suppressed the PC cell-induced transactivation and proliferation of CAFs, reversed CAF-induced resistance, and restored the therapeutic efficacy of gemcitabine in the co-culture system. In addition, CAFs underwent a reverse Warburg effect when co-cultured with PC cells, represented by enhanced aerobic glycolytic metabolism, while shikonin reduced aerobic glycolysis in CAFs by reducing their glucose uptake, ATP concentration, lactate production and secretion, and glycolytic protein expression. Regarding the mechanism underlying these sensitizing effects, shikonin suppressed monocarboxylate transporter 4 (MCT4) expression and cellular membrane translocation to inhibit aerobic glycolysis in CAFs. Overexpression of MCT4 accordingly reversed the inhibitory effects of shikonin on PC cell-induced transactivation and aerobic glycolysis in CAFs, and reduced its sensitizing effects. Furthermore, shikonin promoted the effects of gemcitabine in reducing the growth of tumors derived from PC cells and CAF co-inoculation in BALB/C mice, with no significant systemic toxicity.

CONCLUSION

These results indicate that shikonin reduced MCT4 expression and activation, resulting in inhibition of aerobic glycolysis in CAFs and overcoming CAF-induced gemcitabine resistance in PC. Shikonin is a promising chemosensitizing phytochemical agent when used in combination with gemcitabine for PC treatment. The results suggest that disrupting the metabolic coupling between cancer cells and stromal cells might provide an attractive strategy for improving gemcitabine efficacy.

Zinc treatment reverses and anti-Zn-regulated miRs suppress esophageal carcinomas in vivo

Esophageal squamous cell carcinoma (ESCC) is a deadly disease with few prevention or treatment options. ESCC development in humans and rodents is associated with Zn deficiency (ZD), inflammation, and overexpression of oncogenic microRNAs: miR-31 and miR-21. In a ZD-promoted ESCC rat model with upregulation of these miRs, systemic antimiR-31 suppresses the miR-31-EGLN3/STK40-NF-κB-controlled inflammatory pathway and ESCC. In this model, systemic delivery of Zn-regulated antimiR-31, followed by antimiR-21, restored expression of tumor-suppressor proteins targeted by these specific miRs: STK40/EGLN3 (miR-31), PDCD4 (miR-21), suppressing inflammation, promoting apoptosis, and inhibiting ESCC development. Moreover, ESCC-bearing Zn-deficient (ZD) rats receiving Zn medication showed a 47% decrease in ESCC incidence vs. Zn-untreated controls. Zn treatment eliminated ESCCs by affecting a spectrum of biological processes that included downregulation of expression of the two miRs and miR-31-controlled inflammatory pathway, stimulation of miR-21-PDCD4 axis apoptosis, and reversal of the ESCC metabolome: with decrease in putrescine, increase in glucose, accompanied by downregulation of metabolite enzymes ODC and HK2. Thus, Zn treatment or miR-31/21 silencing are effective therapeutic strategies for ESCC in this rodent model and should be examined in the human counterpart exhibiting the same biological processes.

The novel importance of miR-143 in obesity regulation

Obesity and substantially increased risk of metabolic diseases have become a global epidemic. microRNAs have attracted a great deal of attention as a potential therapeutic target for obesity. MiR-143 has been known to specifically promote adipocyte differentiation by downregulating extracellular signal-regulated kinase 5. Our latest study found that miR-143 knockout is against diet-induced obesity by promoting brown adipose tissue thermogenesis and inhibiting white adipose tissue adipogenesis. Moreover, LPS- or IL-6-induced inhibition of miR-143 expression in brown adipocytes promotes thermogenesis by targeting adenylate cyclase 9. In this review, we will summarize the expression and functions of miR-143 in different tissues, the influence of obesity on miR-143 in various tissues, the important role of adipose-derived miR-143 in the development of obesity, the role of miR-143 in immune cells and thermoregulation and discuss the potential significance and application prospects of miR-143 in obesity management.

miR-143-Mediated Responses to Betaine Supplement Repress Lipogenesis and Hepatic Gluconeogenesis by Targeting MAT1a and MAPK11

The liver as the central organ is responsible for lipogenesis, gluconeogenesis and one-carbon metabolism. Methyl donors (e.g., betaine) modulate metabolic homeostasis and gene regulation through one-carbon metabolism. MiR-143 regulates DNA methylation by targeting DNMT3A, thereby suggesting that this miRNA participates in one-carbon metabolic pathways. However, the effect and mechanism that regulate glucose and lipid metabolism via the methyl group metabolism pathway remain elusive. In this study, we found that a betaine supplement and miR-143 KO significantly promoted lipolysis and glucose utilization and repressed lipogenesis and gluconeogenesis through enhancing energy consumption and thermogenesis, repressing GPNMB and targeting MAPK11, respectively. We further explored the relationship between miR-143 and a methyl donor (betaine) and the miR-143-mediated responses to the betaine supplement regulating the mechanism of the glucose and lipid metabolism. The results showed that betaine significantly down-regulated the expression of miR-143 that subsequently increased SAM levels in the liver by targeting MAT1a. In brief, the regulations of glucose and lipid metabolism are related to the miR-143-regulation of one-carbon units, and the relationship between betaine and miR-143 in the methionine cycle is a typical yin-yang type of regulation. Thus, betaine and miR-143 function together as key regulators and biomarkers for preventing and diagnosing metabolic diseases such as fatty liver disease, obesity, and diabetes.

Gut microbiome composition and serum metabolome profile among individuals with spinal cord injury and normal glucose tolerance or prediabetes/type 2 diabetes

OBJECTIVE

To compare the gut microbiome composition and serum metabolome profile among individuals with spinal cord injury (SCI) and normal glucose tolerance (NGT) or prediabetes/type 2 diabetes (P/DM).

DESIGN

Cross-sectional design.

SETTING

Research university.

PARTICIPANTS

A total of 25 adults with SCI were included in the analysis and categorized as NGT (n=16) or P/DM (n=9) based on their glucose concentration at minute 120 during a 75-g oral glucose tolerance test. The American Diabetes Association diagnosis guideline was used for grouping participants.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE(S)

A stool sample was collected and used to assess the gut microbiome composition (alpha and beta diversity, microbial abundance) via the 16s rRNA sequencing technique. A fasting serum sample was used for liquid chromatography-mass spectrometry-based untargeted metabolomics analysis, the results from which reflect the relative quantity of metabolites detected and identified. Gut microbiome and metabolomics data were analyzed by the Quantitative Insights into Microbial Ecology 2 and Metaboanalyst platforms, respectively.

RESULTS

Gut microbiome alpha diversity (Pielou's evenness index, Shannon's index) and beta diversity (weighted UniFrac distances) differed between groups. Compared with participants with NGT, participants with P/DM had less evenness in microbial communities. In particular, those with P/DM had a lower abundance of the Clostridiales order and higher abundance of the Akkermansia genus, as well as higher serum levels of gut-derived metabolites, including indoxyl sulfate and phenylacetylglutamine (P < 0.05 for all).

CONCLUSION(S)

Our results provide evidence for altered gut microbiome composition and dysregulation of gut-derived metabolites in participants with SCI and P/DM. Both indoxyl sulfate and phenylacetylglutamine have been implicated in the development of cardiovascular diseases in the able-bodied population. These findings may inform future investigations in the field of SCI and cardio-metabolic health.

Potential pathways of zinc deficiency-promoted tumorigenesis

Zinc (Zn) is the second most abundant necessary trace element in the human body. It is reported that zinc deficiency (ZD) promotes many types of cancer progression through multiple signal pathways. It is well known that oxidative stress, DNA damage, DNA repair, cell cycle, cell apoptosis, metabolic alterations, microRNAs abnormal expression, and inflammation level are closely related to cancer development. Cumulative evidence suggests that ZD influences these biological functions. This review explores the latest advances in understanding the role of ZD in tumorigenesis. Fully comprehending the potential mechanisms of ZD-induced tumors may provide novel clues for prevention and clinical treatment of cancers.

Regulation of Glycolysis by Non-coding RNAs in Cancer: Switching on the Warburg Effect

The “Warburg effect” describes the reprogramming of glucose metabolism away from oxidative phosphorylation toward aerobic glycolysis, and it is one of the hallmarks of cancer cells. Several factors can be involved in this process, but in this review, the roles of non-coding RNAs (ncRNAs) are highlighted in several types of human cancer. ncRNAs, including microRNAs, long non-coding RNAs, and circular RNAs, can all affect metabolic enzymes and transcription factors to promote glycolysis and modulate glucose metabolism to enhance the progression of tumors. In particular, the 5′-AMP-activated protein kinase (AMPK) and the phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathways are associated with alterations in ncRNAs. A better understanding of the roles of ncRNAs in the Warburg effect could ultimately lead to new therapeutic approaches for suppressing cancer.

Xanthohumol suppresses glioblastoma via modulation of Hexokinase 2 -mediated glycolysis

Deregulation of aerobic glycolysis is a common phenomenon in human cancers, including glioblastoma (GBM). In the present study, we demonstrated that the natural compound xanthohumol has a profound anti-tumor effect on GBM via direct inhibition of glycolysis. Xanthohumol suppressed cell proliferation and colony formation of GBM cells, and significantly impaired glucose metabolism via inhibiting Hexokinase 2 (HK2) expression. We demonstrated that down-regulation of c-Myc was required for xanthohumol-induced decrease of HK2. Xanthohumol destabilization of c-Myc, and promoted FBW7-mediated ubiquitination of c-Myc. Xanthohumol attenuated Akt activity and inhibited the activation of GSK3β, resulted in c-Myc degradation. Overexpression of Myr-Akt1 significantly rescued xanthohumol-mediated c-Myc inhibition and glycolysis suppression. Finally, the xanthohumol-mediated down-regulation of the PI3-K/Akt-GSK3beta-FBW7 signaling axis promoted the destabilization of c-Myc. Finally, the animal results demonstrated that xanthohumol substantially inhibited tumor growth in vivo. Collectively, xanthohumol appears to be a promising new anti-tumor agent with the therapeutic potential for GBM.

The critical role of microRNAs in stress response: Therapeutic prospect and limitation

Stress response refers to the systemic nonspecific response upon exposure to strong stimulation or chronic stress, such as severe trauma, shock, infection, burn, major surgery or improper environment, which disturb organisms and damage their physical and psychological health. However, the pathogenesis of stress induced disorder remains complicated and diverse under different stress exposure. Recently, studies have revealed a specific role of microRNAs (miRNAs) in regulating cellular function under different types of stress, suggesting a significant role in the treatment and prevention of stress-related diseases, such as stress ulcer, posttraumatic stress disorder, stress-induced cardiomyopathy and so on. This paper have reviewed the literature on microRNA related stress diseases in different databases including PubMed, Web of Science, and the MiRbase. It considers only peer-reviewed papers published in English between 2004 and 2018. This review summarizes new advances in principles and mechanisms of miRNAs regulating stress signalling pathway and the role of miRNAs in human stress diseases. This comprehensive review is to provide an integrated account of how different stresses affect miRNAs and how stress-miRNA pathways may, in turn, be linked with disease, which offers some potential strategies for stress disorder treatment. Furthermore, the limitation of current studies and challenges for clinical use are discussed.

Metabolic Pathways of the Warburg Effect in Health and Disease: Perspectives of Choice, Chain or Chance

Focus on the Warburg effect, initially descriptive of increased glycolysis in cancer cells, has served to illuminate mitochondrial function in many other pathologies. This review explores our current understanding of the Warburg effect’s role in cancer, diabetes and ageing. We highlight how it can be regulated through a chain of oncogenic events, as a chosen response to impaired glucose metabolism or by chance acquisition of genetic changes associated with ageing. Such chain, choice or chance perspectives can be extended to help understand neurodegeneration, such as Alzheimer’s disease, providing clues with scope for therapeutic intervention. It is anticipated that exploration of Warburg effect pathways in extreme conditions, such as deep space, will provide further insights crucial for comprehending complex metabolic diseases, a frontier for medicine that remains equally significant for humanity in space and on earth.

HOTAIR regulates HK2 expression by binding endogenous miR-125 and miR-143 in oesophageal squamous cell carcinoma progression

Esophageal Squamous Cell Carcinoma (ESCC) is one of the most common malignant cancers worldwide with a high death rate worldwide. Long non-coding RNA (LncRNA) has been recently demonstrated to play a critical role in ESCC. LncRNA HOTAIR played important regulatory roles in ESCC. We highlight the molecular mechanisms by which HOTAIR could influence the expression of Hexokinase 2 (HK2) in ESCC through binding miR-125 and miR-143 directly. Taken together, this study identified a functional lncRNA HOTAIR involved with regulation of glycolysis via miRNA-125/miRNA-143-HK2 in ESCC cells. The “competitive endogenous RNA” (ceRNA) model of HOTAIR/miR-125 and miR143/HK2 interaction might serve as important targets for ESCC diagnosis and therapy.