Impact of high glucose on metastasis of colon cancer cells

Synergistic antitumor effects of Phlorizin and Temozolomide in glioblastoma: Mechanistic insights and molecular targeting

Glioblastoma (GBM), one of the most aggressive brain cancers, presents significant treatment challenges due to its complex biology and resistance to conventional therapies, necessitating the development of new, low-toxicity, and effective treatments. This study explores the antitumor potential of phlorizin, a naturally occurring dihydrochalcone, as a standalone agent and in combination with temozolomide (TMZ), the standard chemotherapeutic for GBM. Phlorizin was found to significantly inhibit cell viability and migration in vitro, with synergistic effects observed when combined with TMZ. Comprehensive analyses, including protein-protein interaction network construction, enrichment analysis, and molecular docking with AKT1, identified the PI3K/AKT/mTOR signaling pathway as a critical mediator of glioblastoma cell survival and proliferation targeted by phlorizin. Pathway enrichment analysis of 88 intersection targets further highlighted this pathway's role in phlorizin's activity. Western blot validation confirmed that phlorizin inhibits the expression of key proteins within the PI3K/AKT/mTOR pathway, providing a mechanistic basis for its antitumor effects. These findings suggest that phlorizin, particularly in combination with TMZ, holds significant potential as a therapeutic strategy for glioblastoma by targeting molecular pathways critical for cancer cell survival and proliferation.

"Hyperglycemic Memory": Observational Evidence to Experimental Inference

Several epidemiological studies have appreciated the impact of "duration" and "level" of hyperglycemia on the initiation and development of chronic complications of diabetes. However, glycemic profiles could not fully explain the presence/absence and severity of diabetic complications. Genetic issues and concepts of "hyperglycemic memory" have been introduced as additional influential factors involved in the pathobiology of late complications of diabetes. In the extended phase of significant diabetes randomized, controlled clinical trials, including DCCT/EDIC and UKPDS, studies have concluded that the quality of glycemic or metabolic control at the early time around the diabetes onset could maintain its protective or detrimental impact throughout the following diabetes course. There is no reliable indication of the mechanism by which the transient exposure to a given glucose concentration level could evoke a consistent cellular response at target tissues at the molecular levels. Some biological phenomena, such as the production and the concentration of advanced glycation end products (AGEs), reactive oxygen species (ROS) and protein kinase C (PKC) pathway activations, epigenetic changes, and finally, the miRNAs-mediated pathways, may be accountable for the development of hyperglycemic memory. This work summarizes evidence from previous experiments that may substantiate the hyperglycemic memory soundness by its justification in molecular terms.

The effect of GLP-1R agonists on the medical triad of obesity, diabetes, and cancer

Glucagon-like peptide-1 receptor (GLP-1R) agonists have garnered significant attention for their therapeutic potential in addressing the interconnected health challenges of diabetes, obesity, and cancer. The role of GLP-1R in type 2 diabetes mellitus (T2DM) is highlighted, emphasizing its pivotal contribution to glucose homeostasis, promoting β-cell proliferation, and facilitating insulin release. GLP-1R agonists have effectively managed obesity by reducing hunger, moderating food intake, and regulating body weight. Beyond diabetes and obesity, GLP-1R agonists exhibit a multifaceted impact on cancer progression across various malignancies. The mechanisms underlying these effects involve the modulation of signaling pathways associated with cell growth, survival, and metabolism. However, the current literature reveals a lack of in vivo studies on specific GLP-1R agonists such as semaglutide, necessitating further research to elucidate its precise mechanisms and effects, particularly in cancer. While other GLP-1R agonists have shown promising outcomes in mitigating cancer progression, the association between some GLP-1R agonists and an increased risk of cancer remains a topic requiring more profound investigation. This calls for more extensive research to unravel the intricate relationships between the GLP-1R agonist and different cancers, providing valuable insights for clinicians and researchers alike.

HKDC1 functions as a glucose sensor and promotes metabolic adaptation and cancer growth via interaction with PHB2

Glucose sensing and metabolic adaptation to glucose availability in the tumor microenvironment are critical for cancer development. Here we show that HKDC1, a hexokinase highly expressed in cancer associated with poor prognosis, functions as a glucose sensor that alters its stability in response to environmental glucose. The glucose-sensing domain is located between amino acids 751-917, with Ser896 as a key residue that regulates HKDC1 stability by affecting Lys620 ubiquitination. This sensing mechanism enables cellular adaptation to glucose starvation by promoting mitochondrial fatty acid utilization. Furthermore, HKDC1 promotes tumor growth by sequestering prohibitin 2 (PHB2) to disable its suppressive effect on SP1, thus promoting the expression of pro-oncogenic molecules. Abrogation of HKDC1 by genetic knockout or by glucose depletion releases PHB2, leading to suppression of cancer cell proliferation and inhibition of tumor growth. Our study reveals a previously unrecognized role of HKDC1 in glucose sensing and metabolic adaptation, and identifies HKDC1 as a potential therapeutic target.

Hyperglycemic environments directly compromise intestinal epithelial barrier function in an organoid model and hyaluronan (∼35 kDa) protects via a layilin dependent mechanism

BACKGROUND

Metabolic syndrome and diabetes in obese individuals are strong risk factors for development of inflammatory bowel disease (IBD) and colorectal cancer. The pathogenic mechanisms of low-grade metabolic inflammation, including chronic hyperglycemic stress, in disrupting gut homeostasis are poorly understood. In this study, we sought to understand the impact of a hyperglycemic environment on intestinal barrier integrity and the protective effects of small molecular weight (35 kDa) hyaluronan on epithelial barrier function.

METHODS

Intestinal organoids derived from mouse colon were grown in normal glucose media (5 mM) or high glucose media (25 mM) to study the impact of hyperglycemic stress on the intestinal barrier. Additionally, organoids were pretreated with 35 kDa hyaluronan (HA35) to investigate the effect of hyaluronan on epithelial barrier under high glucose stress. Immunoblotting as well as confocal imaging was used to understand changes in barrier proteins, quantitative as well as spatial distribution, respectively. Alterations in barrier function were measured using trans-epithelial electrical resistance and fluorescein isothiocyanate flux assays. Untargeted proteomics analysis was performed to elucidate mechanisms by which HA35 exerts a protective effect on the barrier. Intestinal organoids derived from receptor knockout mice specific to various HA receptors were utilized to understand the role of HA receptors in barrier protection under high glucose conditions.

RESULTS

We found that high glucose stress decreased the protein expression as well as spatial distribution of two key barrier proteins, zona occludens-1 (ZO-1) and occludin. HA35 prevented the degradation or loss of ZO-1 and maintained the spatial distribution of both ZO-1 and occludin under hyperglycemic stress. Functionally, we also observed a protective effect of HA35 on the epithelial barrier under high glucose conditions. We found that HA receptor, layilin, was involved in preventing barrier protein loss (ZO-1) as well as maintaining spatial distribution of ZO-1 and occludin. Additionally, proteomics analysis showed that cell death and survival was the primary pathway upregulated in organoids treated with HA35 under high glucose stress. We found that XIAP associated factor 1 (Xaf1) was modulated by HA35 thereby regulating apoptotic cell death in the intestinal organoid system. Finally, we observed that spatial organization of both focal adhesion kinase (FAK) as well as F-actin was mediated by HA35 via layilin.

CONCLUSION

Our results highlight the impact of hyperglycemic stress on the intestinal barrier function. This is of clinical relevance, as impaired barrier function has been observed in individuals with metabolic syndrome. Additionally, we demonstrate barrier protective effects of HA35 through its receptor layilin and modulation of cellular apoptosis under high glucose stress.

Associations between blood glucose and early- and late-onset colorectal cancer: evidence from two prospective cohorts and Mendelian randomization analyses

Background

The incidence of early-onset colorectal cancer (EOCRC), which exhibits differential clinical, pathological, and molecular features compared to late-onset CRC (LOCRC), is rising globally. The potential differential effects of blood glucose on EOCRC compared to LOCRC have not been investigated.

Methods

This study analyzed 374,568 participants from the UK Biobank cohort and 172,809 participants from the Kailuan cohort. The linear associations between blood glucose and EOCRC/LOCRC were estimated using Cox regression models. Restricted cubic spline (RCS) analysis and non-linear Mendelian randomization (MR) analysis using a 70-SNPs genetic instrument for fasting glucose were used to explore the potential non-linear associations.

Results

Participants in the highest quintile of blood glucose had higher overall CRC risk compared to the lowest quintile (HR = 1.10 in the UK Biobank cohort, 95% CI: 1.01-1.21, P-trend = 0.012; HR = 1.23 in the Kailuan cohort, 95% CI: 1.01-1.51, P-trend = 0.036). Elevated glucose (>7.0 mmol/L) was more strongly associated with increased risk of EOCRC (HR = 1.61, 95% CI: 1.07-2.44) than with LOCRC (HR = 1.14, 95% CI: 1.02-1.27) in the UK Biobank cohort (P-heterogeneity = 0.014). Elevated glucose (>7.0 mmol/L) was associated with increased risk of LOCRC (HR = 1.25, 95% CI: 1.04-1.65) in the Kailuan cohort as well. There was no evidence for non-linear associations between blood glucose and risks of EOCRC/LOCRC.

Conclusions

This study showed a positive association between blood glucose and CRC risk in a dose-response manner, particularly for EOCRC, suggesting that tighter glucose control should be a priority for younger age groups.

High glucose microenvironment and human mesenchymal stem cell behavior

High glucose (HG) culture conditions in vitro and persistent exposure to hyperglycemia in diabetes patients are detrimental to stem cells, analogous to any other cell type in our body. It interferes with diverse signaling pathways, i.e. mammalian target of rapamycin (mTOR)-phosphoinositide 3-kinase (PI3K)-Akt signaling, to impact physiological cellular functions, leading to low cell survival and higher cell apoptosis rates. While elucidating the underlying mechanism responsible for the apoptosis of adipose tissue-derived mesenchymal stem cells (MSCs), a recent study has shown that HG culture conditions dysregulate mTOR-PI3K-Akt signaling in addition to mitochondrial malfunctioning due to defective mitochondrial membrane potential (MtMP) that lowers ATP production. This organelle-level dysfunction energy-starves the cells and increases oxidative stress and ultrastructural abnormalities. Disruption of the mitochondrial electron transport chain produces an altered mitochondrial NAD+/NADH redox state as evidenced by a low NAD+/NADH ratio that primarily contributes to the reduced cell survival in HG. Some previous studies have also reported altered mitochondrial membrane polarity (causing hyperpolarization) and reduced mitochondrial cell mass, leading to perturbed mitochondrial homeostasis. The hostile microenvironment created by HG exposure creates structural and functional changes in the mitochondria, altering their bioenergetics and reducing their capacity to produce ATP. These are significant data, as MSCs are extensively studied for tissue regeneration and restoring their normal functioning in cell-based therapy. Therefore, MSCs from hyperglycemic donors should be cautiously used in clinical settings for cell-based therapy due to concerns of their poor survival rates and increased rates of post engraftment proliferation. As hyperglycemia alters the bioenergetics of donor MSCs, rectifying the loss of MtMP may be an excellent target for future research to restore the normal functioning of MSCs in hyperglycemic patients.

Matrix metalloproteinase-2 inducing COL1A1 synthesis via integrin alpha Ⅴ promotes invasion and metastasis of cholangiocarcinoma cells

INTRODUCTION AND OBJECTIVES

Cholangiocarcinoma (CCA) is characterized by early distant invasion and metastasis, whereas the underlying mechanism is still obscure. Increasing evidence shows that collagen type Ι alpha 1 (COL1A1) is a gene associated with the progression of multiple diseases. Here, we attempted to investigate the role of COL1A1 in CCA.

MATERIALS AND METHODS

The expression of COL1A1 between tumor tissues and adjacent normal tissues obtained from CCA patients was detected by Western blot and immunofluorescence, followed by analysis of its clinical significance. Then, the biological effects of COL1A1 overexpression or knockdown on CCA cells were evaluated in vitro and in vivo. Finally, molecular mechanism of COL1A1 in regulating the invasion and metastasis of CCA cells was determined by a series of experiments.

RESULTS

COL1A1 expression was significantly higher in CCA pathological tissues than in corresponding adjacent normal tissues. Analysis of 83 CCA patients showed that higher expression of COL1A1 was correlated with poorer patient prognosis. Notably, overexpression or knockdown experiments revealed that COL1A1 contributed to the migration and invasion, as well as epithelial-to-mesenchymal transition (EMT), in CCA cells. Further investigations demonstrated that matrix metalloproteinase-2 (MMP2) promoted COL1A1 upregulation via the integrin alpha Ⅴ pathway, therefore affecting ECM remodelling and inducing EMT in CCA cells. Moreover, COL1A1 expression was positively related to PD-1 and PD-L1 in CCA, and COL1A1 increased PD-L1 expression by activating the NF-κB pathway.

CONCLUSIONS

COL1A1 plays an important role in regulating CCA progression and may act as a promising biomarker and therapeutic target for CCA.

The Mechanical and Biological Performance of Photopolymerized Gelatin-Based Hydrogels as a Function of the Reaction Media

From the first experiments with biomaterials to mimic tissue properties, the mechanical and biochemical characterization has evolved extensively. Several properties can be described, however, what should be essential is to conduct a proper and physiologically relevant characterization. Herein, the influence of the reaction media (RM) and swelling media (SM)-phosphate buffered saline (PBS) and Dulbecco's modified Eagle's medium (DMEM) with two different glucose concentrations-is described in gelatin methacrylamide (GelMA) hydrogel mechanics and in the biological behavior of two tumoral cell lines (Caco-2 and HCT-116). All scaffolds are UV-photocrosslinked under identical conditions and evaluated for mass swelling ratio and stiffness. The results indicate that stiffness is highly susceptible to the RM, but not to the SM. Additionally, PBS-prepared hydrogels exhibited a higher photopolymerization degree according to high resolution magic-angle spinning (HR-MAS) NMR. These findings correlate with the biological response of Caco-2 and HCT-116 cells seeded on the substrates, which demonstrated flatter morphologies on stiffer hydrogels. Overall, cell viability and proliferation are excellent for both cell lines, and Caco-2 cells displayed a characteristic apical-basal polarization based on F-actin/Nuclei fluorescence images. These characterization experiments highlight the importance of conducting mechanical testing of biomaterials in the same medium as cell culture.

The global burden of colorectal cancer attributable to high plasma glucose in 204 countries and territories, 1990-2019: an analysis of the Global Burden of Disease Study

OBJECTIVES

This study aimed to estimate the burden of colorectal cancer (CRC) attributable to high plasma glucose from 1990 to 2019.

STUDY DESIGN AND METHODS

Data on the disease burden were retrieved from the Global Burden of Disease online database. Estimated average percentage change (EAPC) was used to quantify the age-standardized mortality rate (ASMR) and age-standardized disability-adjusted life years (DALYs) rate (ASDR) of high plasma glucose-related CRC trends by sex and location between 1990 and 2019.

RESULTS

Globally, the death number and DALYs of CRC attributable to high plasma glucose remained a steady increase at global level from 1990 to 2019, and similar trends have been reported in age-standardized rate. The country with the largest number of death cases and DALYs of high plasma glucose-related CRC in 2019 was China, followed by the United States of America and India. Nearly three-quarters of total countries experienced an increase in the ASMR and ASDR, and the greatest increase of ASMR and ASDR was found in Uzbekistan (EAPC = 5.32) and Equatorial Guinea (EAPC = 4.65), respectively. A negative correlation was found between sociodemographic indices and the EAPC of ASMR and ASDR (r_ASMR = -0.259, p < 0.001; r_ASDR = -0.282, p < 0.001).

CONCLUSIONS

A significant increase in mortality and DALYs of CRC attributable to high plasma glucose was observed in global and most countries, especially in the developing countries. Public health policies and targeted programs are needed to reduce the burden of disease.

Ethnic disparities in mortality and group-specific risk factors in the UK Biobank

Despite a substantial overall decrease in mortality, disparities among ethnic minorities in developed countries persist. This study investigated mortality disparities and their associated risk factors for the three largest ethnic groups in the United Kingdom: Asian, Black, and White. Study participants were sampled from the UK Biobank (UKB), a prospective cohort enrolled between 2006 and 2010. Genetics, biological samples, and health information and outcomes data of UKB participants were downloaded and data-fields were prioritized based on participants with death registry records. Kaplan-Meier method was used to evaluate survival differences among ethnic groups; survival random forest feature selection followed by Cox proportional-hazard modeling was used to identify and estimate the effects of shared and ethnic group-specific mortality risk factors. The White ethnic group showed significantly worse survival probability than the Asian and Black groups. In all three ethnic groups, endoscopy and colonoscopy procedures showed significant protective effects on overall mortality. Asian and Black women show lower relative risk of mortality than men, whereas no significant effect of sex was seen for the White group. The strongest ethnic group-specific mortality associations were ischemic heart disease for Asians, COVID-19 for Blacks, and cancers of respiratory/intrathoracic organs for Whites. Mental health-related diagnoses, including substance abuse, anxiety, and depression, were a major risk factor for overall mortality in the Asian group. The effect of mental health on Asian mortality, particularly for digestive cancers, was exacerbated by an observed hesitance to answer mental health questions, possibly related to cultural stigma. C-reactive protein (CRP) serum levels were associated with both overall and cause-specific mortality due to COVID-19 and digestive cancers in the Black group, where elevated CRP has previously been linked to psychosocial stress due to discrimination. Our results point to mortality risk factors that are group-specific and modifiable, supporting targeted interventions towards greater health equity.

Glucose and Inositol Transporters, SLC5A1 and SLC5A3, in Glioblastoma Cell Migration

(1) Background: The recurrence of glioblastoma multiforme (GBM) is mainly due to invasion of the surrounding brain tissue, where organic solutes, including glucose and inositol, are abundant. Invasive cell migration has been linked to the aberrant expression of transmembrane solute-linked carriers (SLC). Here, we explore the role of glucose (SLC5A1) and inositol transporters (SLC5A3) in GBM cell migration. (2) Methods: Using immunofluorescence microscopy, we visualized the subcellular localization of SLC5A1 and SLC5A3 in two highly motile human GBM cell lines. We also employed wound-healing assays to examine the effect of SLC inhibition on GBM cell migration and examined the chemotactic potential of inositol. (3) Results: While GBM cell migration was significantly increased by extracellular inositol and glucose, it was strongly impaired by SLC transporter inhibition. In the GBM cell monolayers, both SLCs were exclusively detected in the migrating cells at the monolayer edge. In single GBM cells, both transporters were primarily localized at the leading edge of the lamellipodium. Interestingly, in GBM cells migrating via blebbing, SLC5A1 and SLC5A3 were predominantly detected in nascent and mature blebs, respectively. (4) Conclusion: We provide several lines of evidence for the involvement of SLC5A1 and SLC5A3 in GBM cell migration, thereby complementing the migration-associated transportome. Our findings suggest that SLC inhibition is a promising approach to GBM treatment.

Differences in glucose concentration shows new perspectives in gastric cancer metabolism

Gastric cancer (GC) is among the deadliest cancers worldwide despite available therapies, highlighting the need for novel therapies and pharmacological agents. Metabolic deregulation is a potential study area for new anticancer targets, but the in vitro metabolic studies are controversial, as different ranges of glucose used in the culture medium can influence results. In this study, we evaluated cellular viability, glucose uptake, and LDH activity in gastric cell lines when exposed to different glucose concentrations: high (HG, 25 mM), low (LG, 5.5 mM), and free (FG, 0 mM) glucose mediums. Moreover, we evaluated how glucose variations may influence cellular phenotype and the expression of genes related to epithelial-mesenchymal transition (EMT), metabolism, and cancer development in metastatic GC cells (AGP-01). Results showed that in the FG metastatic cells evidenced higher viability when compared with other cell lines and that when exposed to either LG or HG mediums most of the phenotypic assays did not differ. However, cells exposed to LG increased colony formation and mRNA levels of metabolic-related genes when compared to HG medium. Our results recommend LG medium to metabolic studies once glucose concentration is closer to physiological levels. These findings are important to point out new relevant targets in metabolic reprogramming that can be alternatives to current chemotherapies in patients with metastatic GC.

TNF-α Antagonizes the Effect of Leptin on Insulin Secretion through FOXO1-Dependent Transcriptional Suppression of LepRb in INS-1 Cells

Proinflammatory cytokines play a causal role in the development of hyperinsulinemia and T2MD. FOXO1, a transcription factor which is known to enhance proinflammation, was recently shown to be involved in obesity-induced β cell dysfunction. However, molecular mechanisms for the association remained elusive. In this study, we first found that both leptin (10 nM) and TNF-α (20 ng/ml) significantly inhibited glucose-stimulated insulin secretion (GSIS) of INS-1E cells. When in combination, the GSIS function of INS-1E cells was significantly increased compared with that of the leptin alone treatment, indicating that TNF-α attenuated the inhibiting effect of leptin on GSIS of INS-1E cells. Similarly, we found that TNF-α has the same inhibitory effect on leptin in regulating insulin synthesis and secretion, and the survival and apoptosis of insulin cells. Further studies showed that TNF-α blocks leptin pathway by reducing the expression of leptin receptor (LepRb, also called OBRb) and inhibiting the activation of STAT3, a key molecule involved in the leptin signaling pathway in INS-1E cells. Besides, the downregulated expression of phosphorylated FOXO1 was found to be involved in the possible mechanism of TNF-α. Overexpression of constitutively active FOXO1 markedly aggravated the LepRb reduction by TNF-α treatment of INS-1E cells, and the endogenous FOXO1 knockdown abolished the effect of TNF-α on INS-1E cells. Furthermore, we have proved that FOXO1 could directly bind to the promoter of LepRb as a negative transcription regulator. Taken together, the results of this study reveal that TNF-α-induced LepRb downregulated in pancreatic β cells and demonstrate that transcriptional reduction of FOXO1 might be the primary mechanism underlying TNF-α promoting INS-1E leptin resistance and β cell dysfunction. Conclusions. Our current studies based on INS-1E cells in vitro indicate that the inflammatory factor TNF-α plays an important role in the development of INS-1E leptin resistance and glucose metabolism disorders, probably through FOXO1-induced transcription reduction of LepRb promoter in pancreatic β cells, and FOXO1 may be a novel target for treating β cell dysfunction in obesity-induced hyperinsulinemia and T2DM.

Effect of diabetes mellitus comorbidity on outcomes in stages II and III colorectal cancer

AIM

The effects of diabetes mellitus (DM) on the outcomes of colorectal cancer (CRC) are controversial. This retrospective study evaluated the effects of DM on American Joint Committee on Cancer (AJCC, 7th) Stages II and III CRC patients who received curative surgery.

METHODS

We reviewed the records of CRC patients who were treated from January 2008 to December 2014 and identified the presence of DM and hypertension prior to CRC diagnosis. Cox proportional hazards analyses were used for prognostic factor determination, and survival was analyzed using the Kaplan-Meier method with the log-rank test.

RESULTS

Total of 1066 consecutive eligible patients with stage II/III CRC were enrolled. There were 326 (30.6%) patients diagnosed with DM, and 311 (29.2%) CRC patients had recurrence. Patients with DM did not have a higher recurrence risk (p = 0.183) but had higher mortality (adjusted hazard ratio [aHR] = 1.381; 95% conference interval [CI], 1.069-1.782). In addition, HbA1c (≥7 vs. <7) was not associated with recurrence (p = 0.365). Patients with DM had more hypertension than patients without DM (69.1% vs. 37.6%, p < 0.001). A lower recurrence risk was noted in patients with hypertension (p = 0.002), but the overall survival (OS) did not reach statistical significance (aHR = 0.910; 95% CI, 0.707-1.169).

CONCLUSION

In our study, DM was a poor prognostic factor for survival in curative CRC patients. More studies are required to elucidate the effects that DM and other metabolic disorders, such as hypertension, have on the prognosis of patients with CRC.

Fasting Plasma Glucose and Incident Colorectal Cancer: Analysis of a Nationwide Epidemiological Database

CONTEXT

Although diabetes mellitus (DM) was reported to be associated with incident colorectal cancer (CRC), the detailed association between fasting plasma glucose (FPG) and incident CRC has not been fully understood.

OBJECTIVE

We assessed whether hyperglycemia is associated with a higher risk for CRC.

DESIGN

Analyses were conducted using the JMDC Claims Database [n = 1 441 311; median age (interquartile range), 46 (40-54) years; 56.6% men). None of the participants were taking antidiabetic medication or had a history of CRC, colorectal polyps, or inflammatory bowel disease. Participants were categorized as normal FPG (FPG level < 100 mg/dL; 1 125 647 individuals), normal-high FPG (FPG level = 100-109 mg/dL; 210 365 individuals), impaired fasting glucose (IFG; FPG level = 110-125 mg/dL; 74 836 individuals), and DM (FPG level ≥ 126 mg/dL; 30 463 individuals).

RESULTS

Over a mean follow-up of 1137 ± 824 days, 5566 CRC events occurred. After multivariable adjustment, the hazard ratios for CRC events were 1.10 (95% CI 1.03-1.18) for normal-high FPG, 1.24 (95% CI 1.13-1.37) for IFG, and 1.36 (95% CI 1.19-1.55) for DM vs normal FPG. We confirmed this association in sensitivity analyses excluding those with a follow-up of< 365 days and obese participants.

CONCLUSION

The risk of CRC increased with elevated FPG category. FPG measurements would help to identify people at high-risk for future CRC.

Type 2 diabetes mellitus promotes the proliferation, metastasis, and suppresses the apoptosis in oral squamous cell carcinoma

BACKGROUND

Our previous study revealed that patients with oral squamous cell carcinoma and concomitant type 2 diabetes mellitus presented a lower 5-year survival rate. Hyperglycemia has been increasingly recognized as a risk factor for more advanced disease and poorer prognosis in patients with oral squamous cell carcinoma. However, its role remains unclear.

METHODS

The expressions of BRIP1, Ki67, E-cadherin, and cleaved caspase-3 were detected by immunohistochemistry in oral squamous cell carcinoma tissues with or without type 2 diabetes mellitus. Cell counting kit-8 assay and wound healing assay were used to determine the proliferative and migratory ability of oral squamous cell carcinoma cells cultured with or without high glucose in vitro. Flow cytometry was applied to distinguish the role of high glucose on the cell cycle and apoptosis rates.

RESULTS

The expression level of Ki67 was elevated while BRIP1, E-cadherin, and cleaved caspase-3 were downregulated in patients with oral squamous cell carcinoma coexisting with diabetes. The cell proliferation and migration in oral squamous cell carcinoma cell lines were significantly enhanced by high glucose. Flow cytometric analysis suggested that high glucose predisposed cancer cells to stay at S/G₂ phase and to exhibit lower apoptosis rates.

CONCLUSION

Our results implicated that type 2 diabetes mellitus may play a crucial role in the development and progression of oral squamous cell carcinoma through hyperglycemia, affecting cancer cell proliferation, migration, and apoptosis. This finding might provide a new direction for the prevention and treatment of oral squamous cell carcinoma.

Fatty acid synthase mediates high glucose-induced EGFR activation in oral dysplastic keratinocytes

BACKGROUND

Recent studies point to the epidermal growth factor receptor (EGFR) as a critical mediator of type 2 diabetes mellitus (T2DM)-induced renal, cardiac, and ocular complications. T2DM is considered a systemic contributing factor in oral carcinogenesis. Similarly, increased EGFR gene copy number and protein expression strongly predict tumor progression. Yet, the impact of hyperglycemia on EGFR activity in oral potentially malignant disorders remains unclear. We recently reported that fatty acid synthase (FASN), a key de novo lipogenic enzyme, mediates EGFR activation in nicotine-treated oral dysplastic keratinocytes. While in non-malignant tissues FASN expression is extremely low, it is frequently upregulated in several cancers, including oral squamous cell carcinoma. The present study was carried out to investigate whether high glucose conditions trigger pro-oncogenic responses in oral dysplastic keratinocytes via FASN-mediated EGFR activation.

METHODS

Cell viability and migration of oral dysplastic keratinocytes were evaluated when exposed to normal (5 mM) or high (20 mM) glucose conditions in the presence of FASN and EGFR inhibitors. Western blotting was also performed to assess changes in FASN protein expression and EGFR activation.

RESULTS

Oral dysplastic keratinocytes exposed to high glucose led to EGFR activation in a FASN-dependent manner. Likewise, high glucose significantly enhanced cell viability and migration in a FASN/EGFR-mediated fashion. Notably, EGFR inhibition by the anti-EGFR monoclonal antibody cetuximab significantly reduced the proliferation of FASN-overexpressing oral dysplastic keratinocytes.

CONCLUSION

These novel findings suggest that FASN may act as a key targetable metabolic regulator of glucose-induced EGFR oncogenic signaling in oral potentially malignant disorders.

High glucose: an emerging association between diabetes mellitus and cancer progression

The association of cancer and diabetes mellitus (DM) has been studied for decades. Hyperglycemia and the imbalance of hormones are factors that contribute to the molecular link between DM and carcinogenesis and cancer progression. Hyperglycemia alone or in combination with hyperinsulinemia are key factors that promote cancer aggressiveness. Many preclinical studies suggest that high glucose induces abnormal energy metabolism and aggressive cancer via several mechanisms. As evidenced by clinical studies, hyperglycemia is associated with poor clinical outcomes in patients who have comorbid DM. The prognoses of cancer patients with DM are improved when their plasma glucose levels are controlled. This suggests that high glucose level maybe be involved in the molecular mechanism that causes the link between DM and cancer and may also be useful for prognosis of cancer progression. This review comprehensively summarizes the evidence from recent pre-clinical and clinical studies of the impact of hyperglycemia on cancer advancement as well as the underlying molecular mechanism for this impact. Awareness among clinicians of the association between hyperglycemia or DM and cancer progression may improve cancer treatment outcome in patients who have DM.

NF-κB and STAT3 co-operation enhances high glucose induced aggressiveness of cholangiocarcinoma cells

AIMS

The present report aimed to investigate the underlying genes and pathways of high glucose driving cholangiocarcinoma (CCA) aggressiveness.

MAIN METHODS

We screened and compared the gene expression profiles obtained by RNA sequencing, of CCA cells cultured in high and normal glucose. Results from the transcriptomic analysis were confirmed in additional cell lines using in vitro migration-invasion assay, Western blotting and immunocytofluorescence.

KEY FINDINGS

Data indicated that high glucose increased the expression of interleukin-1β (IL-1β), an upstream regulator of nuclear factor-κB (NF-κB) pathway, through the nuclear localization of NF-κB. High glucose-induced NF-κB increased the migration and invasion of CCA cells and the expression of downstream NF-κB targeted genes associated with aggressiveness, including interleukin-6, a potent triggering signal of the signal transducer and activator of transcription 3 (STAT3) pathway. Such effects were reversed by inhibiting NF-κB nuclear translocation which additionally reduced the phosphorylation of STAT3 at Y705.

SIGNIFICANCE

These results indicate that NF-κB is activated by high glucose and they suggest that NF-κB interaction with STAT3 enhances CCA aggressiveness. Therefore, targeting multiple pathways such as STAT3 and NF-κB might improve CCA treatment outcome especially in condition such as hyperglycemia.

Platelet-derived PDGF promotes the invasion and metastasis of cholangiocarcinoma by upregulating MMP2/MMP9 expression and inducing EMT via the p38/MAPK signalling pathway

Cholangiocarcinoma (CCA) is an aggressive tumour with a poor prognosis due to its late clinical presentation and the lack of effective non-surgical therapies. Previous studies have reported that platelets are implicated in tumour invasion and metastasis, while their role and the underlying mechanism in CCA remain unclear. Here, we show that platelets are hyperactivated in patients with CCA and that platelet-derived growth factor (PDGF) promotes the migration of CCA tumour cells both in vitro and in vivo. Further investigations revealed that PDGF can upregulate the expression of MMP2/MMP9 and induce epithelial-mesenchymal transition (EMT) by activating the p38/MAPK signalling pathway in CCA cells. In addition, the expression of MMP2/MMP9 was associated with lymph node metastasis and poor prognosis in CCA patients after surgical resection. In conclusion, our findings demonstrate that platelets play an important role in facilitating the invasion and metastasis of CCA cells by secreting PDGF, which may provide a novel target for CCA treatment.

Combined usage of monosaccharides with polysaccharides may decelerate tumor growth and malignance versus solely using a certain kind of saccharide

Saccharides used in clinical nutrients and the hyperglycemia status may facilitate tumor growth and aggravate cancer patients' outcome. As glucose, fructose and maltodextrin are widely used in clinical practice, various effects on tumor progress among them remain unknown. Six kinds of tumor cell lines were included in this study. We evaluated the discrepant effects of sugars on tumor growth by nude mice xenograft model, wound-healing assay and cell counting kit-8 test were for measuring the migration and proliferation capability in vitro, and oral gavage on C57BL/6 N mice was applied to assess the fluctuation of blood glucose level. Results showed that though tumor cells presented discrepant sensitivity to different saccharides, the combined usage of glucose, fructose with maltodextrin has milder effect on tumor progression and moderate effect on blood glucose fluctuation, which may indicate a brighter option on saccharides selection for tumor patients.

STAT3 inhibitory stattic enhances immunogenic cell death induced by chemotherapy in cancer cells

BACKGROUND

Induction of immunogenic cell death (ICD) is considered a promising strategy for cancer immunotherapy. Stattic is an inhibitor of STAT3, which is found constitutively active in many cancers and plays a major role in cancer progression.

OBJECTIVES

In the present study, we proposed to evaluate whether stattic can enhance the effects of chemotherapy in the induction of ICD in cancer cells harboring hyperactive STAT3.

METHODS

The growth inhibitory effects of stattic and chemo agents including doxorubicin (DOX) and oxaliplatin (OXP) were evaluated using MTT assay in B16F10 and CT26 cell lines. Flow cytometry was applied to study cell apoptosis and calreticulin (CRT) surface exposure. The levels of high mobility group box 1 (HGMB1), heat shock protein70 (HSP70) and interleukin-12 (IL-12) were measured using ELISA.

RESULTS

Treatment of B16F10 and CT26 cells with stattic in combination with DOX resulted in synergistic antitumor effects with combination index being 0.82 and 0.87, respectively. Interestingly, we found a higher level of ICD markers including CRT expression as well as HMGB1 and HSP70 secretion in the cells received combination therapy of stattic and DOX as compared with monotherapies. Moreover, exposure of dendritic cells (DCs) to conditioned media (CM) from cancer cells treated with stattic and/or DOX resulted in secretion of IL-12, which is an indicator of DCs maturation and induction of Th1 response. OXP and stattic monotherapy induced ICD in CT26 cells and stimulated IL-12 secretion by DCs; however, we did not observe a significant increase in the level of ICD in CT26 cells and IL-12 secretion by DCs when CT26 cells were treated with stattic and OXP combination as compared with monotherapy groups.

CONCLUSION

These findings indicate that STAT3 inhibitory stattic can increase ICD induced by DOX. Graphical abstract.

Glycoxidative profile of cancer patient serum: A clinical result to associate glycation to cancer

The influence of advanced glycation end products (AGEs) in the biological processes contribute to the life-changing complications such as progression of cancer, diabetes and other chronic disorders. The receptor of AGEs while interacting with its ligands causes a never-ending irregularity in the cell-signaling communication. Hence, AGEs are considered as an important link between progression and contribution to cancer. This study focuses on the presence and/or absence of oxidative and glycative stress in the serum samples of various cancer patients. During analysis of the early and intermediate glycation product in cancer patient’s sera, our result indicates an increasing trend of both the adducts as compared to normal healthy subjects. Similarly, one of the AGEs i.e., carboxymethyllysine was found to be enhanced in cancer sera as compared to NHS. The binding characteristics of circulating auto-antibodies in cancer patient’s sera against human serum albumin (HSA)-AGEs were assessed through ELISA and furthermore, the maximum percent inhibition against HSA-AGEs was observed as 57–63%, 46–62% and 42–64% in prostate cancer, lung cancer and head and neck cancer. Hence, our result successfully assisted the presence of AGEs in all the cancer patient’s sera though it is not clear which specific cancer is more potent to AGEs.

High Glucose Concentrations Negatively Regulate the IGF1R/Src/ERK Axis through the MicroRNA-9 in Colorectal Cancer

Studies have revealed that people with hyperglycemia have a high risk of colorectal cancer (CRC). Hyperglycemia may be responsible for supplying energy to CRC cells. However, the potential molecular mechanism for this association remains unclear. Furthermore, microRNA-9 (miR-9) has a tumor-suppressive function in CRC. Aberrant reduced expression of miR-9 is involved in the development and progression of malignancy caused by a high glucose (HG) concentration. In this study, we used an HG concentration to activate miR-9 downregulation in CRC cells. Our results indicated that miR-9 decreased the insulin-like growth factor-1 receptor (IGF1R)/Src signaling pathway and downstream cyclin B1 and N-cadherin but upregulated E-cadherin. The HG concentration not only promoted cell proliferation, increased the G1 population, and modulated epithelial-to-mesenchymal transition (EMT) protein expression and morphology but also promoted the cell migration and invasion ability of SW480 (low metastatic potential) and SW620 (high metastatic potential) cells. In addition, low glucose concentrations could reverse the effect of the HG concentration in SW480 and SW620 cells. In conclusion, our results provide new evidence for multiple signaling pathways being regulated through hyperglycemia in CRC. We propose that blood sugar control may serve as a potential strategy for the clinical management of CRC.

Plasma C-peptide and glycated albumin and subsequent risk of cancer: From a large prospective case-cohort study in Japan

To elucidate the individual impacts of insulin and blood glucose on cancer risk, we investigated the association of plasma C-peptide, a surrogated marker of insulin and glycated albumin (GA), a more stable marker of blood glucose, with all-site and site-specific cancer risk by mutually accounting for their confounding effects. The study was prospectively conducted with nearly 4,000 cancer cases arising in our population-based cohort of 33,736 subjects who answered the baseline questionnaire and supplied blood samples. After exclusion of subjects with apparent DM, analysis was done in 3,036 cancer cases and 3,667 subcohort subjects. Among men and women combined, highest levels of C-peptide were statistically significantly associated with an increased risk of all-site [Hazard ratio (HR): 1.21; 95% confidence interval: 1.02-1.42], colon [1.73; 1.20-2.47], liver [3.23; 1.76-5.91], kidney, renal pelvis and ureter cancers [2.47; 1.07-5.69], compared to the respective lowest levels, after adjustment for GA levels. Among these C-peptide-related cancers, colon and liver cancers also showed an increased risk associated with elevated GA levels independently of C-peptide levels. The corresponding HRs for colon and liver cancers compared to the highest and lowest GA levels were 1.43 [1.02-2.00] and 2.02 [1.15-3.55], respectively. Effect modification by gender was only evident for the association between C-peptide and colon cancer (p for interaction = 0.04). Higher insulin levels, independently of higher blood glucose levels, may be relevant to DM-related carcinogenesis for several cancer sites. Examination of circulating insulin levels is a plausible option in evaluating cancer risk even in individuals who have not developed DM.

Effects of β-caryophyllene on arginine ADP-ribosyltransferase 1-mediated regulation of glycolysis in colorectal cancer under high-glucose conditions

Type 2 diabetes mellitus (T2DM) is associated with an increased risk of the development of colorectal cancer (CRC). A previous study revealed that the levels of arginine-specific mono-ADP-ribosyltransferase 1 (ART1) in CRC tissues from patients with T2DM were higher than in non-diabetic patients. Hyperglycemia, which is a risk factor of cancer, is a common feature of T2DM; however, the effects of ART1 on glycolysis and energy metabolism in CRC cells under high-glucose conditions remains to be elucidated. β-caryophyllene (BCP) has been reported to exert anticancer and hypoglycemic effects. In the present study, CT26 cells were cultured under a high-glucose conditions and the expression levels of relevant factors were detected by western blotting. Cell Counting Kit-8 assay, flow cytometry, Hoechst 33258 staining, ATP assay and lactic acid assay were used to detect the proliferation, apoptosis and energy metabolism of CT26 cells. To observe the effects of ART1 and BCP on tumor growth in vivo, CT26 cell tumors were successfully transplanted into BALB/c mice with T2DM. The results demonstrated that overexpression of ART1 may increase glycolysis and energy metabolism in CT26 CRC cells under high glucose conditions by regulating the protein kinase B/mammalian target of rapamycin/c‑Myc signaling pathway and the expression of glycolytic enzymes. BCP inhibited the effects induced by ART1, which may be due to a BCP-induced reduction in the expression levels of ART1 via nuclear factor-κB. Therefore, ART1 may be considered a therapeutic target for the treatment of diabetic patients with CRC.

Hyperglycemia-induced mouse trophoblast spreading is mediated by reactive oxygen species

During embryo implantation, the outer layer of the blastocyst interacts with the endometrium giving rise to the development of the trophoblast cell lineage. The cells in this lineage participate in the penetration of endometrium due to their motility and invasive properties. The mechanisms that regulate the differentiation and invasive ability of these cells are essential for the establishment and maintenance of an efficient exchange between maternal and fetal tissues during pregnancy. In this context, hyperglycemia can induce oxidative stress causing alterations in the placenta. This study evaluated the role of reactive oxygen species (ROS) in the actions of high glucose concentration (HG) on trophoblast spreading and the expression of extracellular proteases in cultured mouse conceptuses. Blastocysts from gestational day 4 (GD4) were cultured until GD7 in HAM-F10 medium and further treated for 48 hr with HG (25 mM glucose) from GD7 to GD9. This treatment induced larger trophoblast outgrowths and increased ROS concentration, which was associated with increased expression levels of urokinase-type plasminogen activator (PLAU), plasminogen activator inhibitor 1 (PAI-1), and matrix metalloproteinase 9 (MMP-9). These effects were prevented by treatment with the non-specific antioxidant N-acetylcysteine (NAC) or apocynin, an inhibitor of NADPH oxidase. Our data suggest that the HG-induced trophoblast spreading and the expression of PLAU, PAI-1, and MMP-9 were mediated by the production of ROS via NADPH oxidase activity. Our results shed light on placental alterations in gestational diabetes mellitus.

Activation of PI3K in response to high glucose leads to regulation of SOCS-3 and STAT1/3 signals and induction of glomerular mesangial extracellular matrix formation

Excessive deposition of extracellular matrix (ECM) in the glomerulus contributed by mesangial cells is the hallmark of diabetic nephropathy, eventually leading to glomerulosclerosis. In this study, we examined the regulatory signals involved in the high glucose (HG)-induced overproduction of ECM in rat mesangial cells (RMCs). We disclosed excessive fibronectin and collagen IV production, tyrosine phosphorylation of signal transducer and activator of transcription 1 and 3 (STAT1/3), and up-regulation of suppressor of cytokine signaling-3 (SOCS-3) expression in HG-treated RMCs. STAT1/STAT3 binding element was essential for SOCS-3 promoter activity stimulated by HG. HG was capable of promoting the specific DNA binding activities to an oligonucleotide probe containing the SOCS-3 sequence. The selective phosphoinositide 3-kinase (PI3K) inhibitor LY294002 and dominant negative p85 vector (DNΔp85) transfection effectively abolished these HG-induced responses. Moreover, HG markedly increased the cyclin kinase inhibitor p27^Kip1 protein expression, which could be inhibited by LY294002 or transfection of DNΔp85. Taken together, these results suggest that HG-induced SOCS-3 upregulation depends upon the presence of STAT-binding element in the SOCS-3 promoter, which is specifically activated by STAT1/3. The PI3K/STAT1/3 signaling pathway mediated HG-triggered ECM accumulation and SOCS-3 upregulation in RMCs.

Hyperglycemia exacerbates colon cancer malignancy through hexosamine biosynthetic pathway

Hyperglycemia is a common feature of diabetes mellitus, considered as a risk factor for cancer. However, its direct effects in cancer cell behavior are relatively unexplored. Herein we show that high glucose concentration induces aberrant glycosylation, increased cell proliferation, invasion and tumor progression of colon cancer. By modulating the activity of the rate-limiting enzyme, glutamine-fructose-6-phosphate amidotransferase (GFAT), we demonstrate that hexosamine biosynthetic pathway (HBP) is involved in those processes. Biopsies from patients with colon carcinoma show increased levels of GFAT and consequently aberrant glycans’ expression suggesting an increase of HBP flow in human colon cancer. All together, our results open the possibility that HBP links hyperglycemia, aberrant glycosylation and tumor malignancy, and suggest this pathway as a potential therapeutic target for colorectal cancer.

High glucose levels boost the aggressiveness of highly metastatic cholangiocarcinoma cells via O-GlcNAcylation

Increased glucose utilization is a feature of cancer cells to support cell survival, proliferation, and metastasis. An association between diabetes mellitus and cancer progression was previously demonstrated in cancers including cholangiocarcinoma (CCA). This study was aimed to determine the effects of high glucose on protein O-GlcNAcylation and metastatic potentials of CCA cells. Two pairs each of the parental low metastatic and highly metastatic CCA sublines were cultured in normal (5.6 mM) or high (25 mM) glucose media. The migration and invasion abilities were determined and underlying mechanisms were explored. Results revealed that high glucose promoted migration and invasion of CCA cells that were more pronounced in the highly metastatic sublines. Concomitantly, high glucose increased global O-GlcNAcylated proteins, the expressions of vimentin, hexokinase, glucosamine-fructose-6-phosphate amidotransferase (GFAT) and O-GlcNAc transferase of CCA cells. The glucose level that promoted migration/invasion was shown to be potentiated by the induction of GFAT, O-GlcNAcylation and an increase of O-GlcNAcylated vimentin and vimentin expression. Treatment with a GFAT inhibitor reduced global O-GlcNAcylated proteins, vimentin expression, and alleviated cell migration. Altogether, these results suggested the role of high glucose enhanced CCA metastasis via modulation of O-GlcNAcylation, through the expressions of GFAT and vimentin.

Hyperglycemic memory in metabolism and cancer

Hyperglycemia is a hallmark of both type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). Recent evidence strongly suggests that prolonged exposure to hyperglycemia can epigenetically modify gene expression profiles in human cells and that this effect is sustained even after hyperglycemic control is therapeutically achieved; this phenomenon is called hyperglycemic memory. This metabolic memory effect contributes substantially to the pathology of various diabetic complications, such as diabetic retinopathy, hypertension, and diabetic nephropathy. Due to the metabolic memory in cells, diabetic patients suffer from various complications, even after hyperglycemia is controlled. With regard to this strong association between diabetes and cancer risk, cancer cells have emerged as key target cells of hyperglycemic memory in diabetic cancer patients. In this review, we will discuss the recent understandings of the molecular mechanisms underlying hyperglycemic memory in metabolism and cancer.

Clinically compatible flexible wide-field multi-color fluorescence endoscopy with a porcine colon model

Early detection of structural or molecular changes in dysplastic epithelial tissues is crucial for cancer screening and surveillance. Multi-targeting molecular endoscopic fluorescence imaging may improve noninvasive detection of precancerous lesions in the colon. Here, we report the first clinically compatible, wide-field-of-view, multi-color fluorescence endoscopy with a leached fiber bundle scope using a porcine model. A porcine colon model that resembles the human colon is used for the detection of surrogate tumors composed of multiple biocompatible fluorophores (FITC, ICG, and heavy metal-free quantum dots (hfQDs)). With an ex vivo porcine colon tumor model, molecular imaging with hfQDs conjugated with MMP14 antibody was achieved by spraying molecular probes on a mucosa layer that contains xenograft tumors. With an in vivo porcine colon embedded with surrogate tumors, target-to-background ratios of 3.36 ± 0.43, 2.70 ± 0.72, and 2.10 ± 0.13 were achieved for FITC, ICG, and hfQD probes, respectively. This promising endoscopic technology with molecular contrast shows the capacity to reveal hidden tumors and guide treatment strategy decisions.

Apple Polyphenol Phloretin Inhibits Colorectal Cancer Cell Growth via Inhibition of the Type 2 Glucose Transporter and Activation of p53-Mediated Signaling

Glucose transporters (GLUTs) are required for glucose uptake in malignant cells, and they can be used as molecular targets for cancer therapy. An RT-PCR analysis was performed to investigate the mRNA levels of 14 subtypes of GLUTs in human colorectal cancer (COLO 205 and HT-29) and normal (FHC) cells. RT-PCR (n = 27) was used to assess the differences in paired tissue samples (tumor vs normal) isolated from colorectal cancer patients. GLUT2 was detected in all tested cells. The average GLUT2 mRNA level in 12 of 27 (44.4%) cases was 2.4-fold higher in tumor compared to normal tissues (*, p = 0.027). Higher GLUT2 mRNA expression was preferentially detected in advanced-stage tumors (stage 0 vs 3 = 16.38-fold, 95% CI = 9.22-26.54-fold; *, p = 0.029). The apple polyphenol phloretin (Ph) and siRNA methods were used to inhibit GLUT2 protein expression. Ph (0-100 μM, for 24 h) induced COLO 205 cell growth cycle arrest in a p53-dependent manner, which was confirmed by pretreatment of the cells with a p53-specific dominant negative expression vector. Hepatocyte nuclear factor 6 (HNF6), which was previously reported to be a transcription factor that activates GLUT2 and p53, was also induced by Ph (0-100 μM, for 24 h). The antitumor effect of Ph (25 mg/kg or DMSO twice a week for 6 weeks) was demonstrated in vivo using BALB/c nude mice bearing COLO 205 tumor xenografts. In conclusion, targeting GLUT2 could potentially suppress colorectal tumor cell invasiveness.

High glucose enhances progression of cholangiocarcinoma cells via STAT3 activation

Epidemiological studies have indicated diabetes mellitus (DM) as a risk of cholangiocarcinoma (CCA), however, the effects and mechanisms of high glucose on progression of CCA remain unclear. This study reports for the first time of the enhancing effects of high glucose on aggressive phenotypes of CCA cells via STAT3 activation. CCA cells cultured in high glucose media exerted significantly higher rates of cell proliferation, adhesion, migration and invasion than those cultured in normal glucose. The phosphokinase array revealed STAT3 as the dominant signal activated in response to high glucose. Increased nuclear STAT3, p-STAT3 and its downstream target proteins, cyclin D1, vimentin and MMP2, were shown to be underling mechanisms of high glucose stimulation. The link of high glucose and STAT3 activation was confirmed in tumor tissues from CCA patients with DM that exhibited higher STAT3 activation than those without DM. Moreover, the levels of STAT3 activation were correlated with the levels of blood glucose. Finally, decreasing the level of glucose or using a STAT3 inhibitor could reduce the effects of high glucose. These findings suggest that controlling blood glucose or using a STAT3 inhibitor as an alternative approach may improve the therapeutic outcome of CCA patients with DM.

A Linear Dose-Response Relationship between Fasting Plasma Glucose and Colorectal Cancer Risk: Systematic Review and Meta-analysis

For many years, the question of whether hyperglycaemia, a manifestation of prediabetes, diabetes mellitus and metabolic syndrome, is a risk factor for colorectal cancer has been intensely studied. In fact, even after the conclusion of several prospective studies, the topic is still controversial. We conducted a systematic review and meta-analysis to investigate the dose-response relationship between blood glucose concentration and the incidence of colorectal cancer. A linear (P = 0.303 for non-linearity) dose-response relationship was observed between fasting plasma glucose (FPG) and colorectal cancer risk without significant heterogeneity. The relative risk (RR) for colorectal cancer per 20 mg/dL increase in FPG was 1.015 (95% CI: 1.012-1.019, P = 0.000). In subgroup analyses, the pooled RRs for colon cancer (CC) and rectal cancer (RC) studies were 1.035 (95% CI 1.008-1.062, P = 0.011) and 1.031 (95% CI: 0.189-5.628, P = 0.972), respectively; in the analysis comparing men and women, the pooled RRs were 1.016 (95% CI: 1.012-1.020, P = 0.000) and 1.011 (95% CI: 0.995-1.027, P = 0.164), respectively. Sensitivity analyses using two methods showed similar results. In conclusion, there is a significant linear dose-response relationship between FPG and the incidence risk of colorectal cancer. For people with diabetes or prediabetes, controlling blood glucose might be useful to prevent colorectal cancer.