Hyperactivation of Akt/mTOR and deficiency in tuberin increased the oxidative DNA damage in kidney cancer patients with diabetes

Plasma Proteomics of Type 2 Diabetes, Hypertension, and Co-Existing Diabetes/Hypertension in Thai Adults

The study explored proteomics to better understand the relationship between type 2 diabetes (T2DM) and hypertension (HT) in Thai adults, using shotgun proteomics and bioinformatics analysis. Plasma samples were taken from 61 subjects: 14 healthy subjects (mean age = 40.85 ± 7.12), 13 with T2DM (mean age = 57.38 ± 6.03), 16 with HT (mean age = 66.87 ± 10.09), and 18 with coexisting T2DM/HT (mean age = 58.22 ± 10.65). Proteins were identified using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Protein-protein interactions were analyzed using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) version 11.5. We identified six unique proteins in T2DM patients, including translationally controlled 1 (TPT1) and nibrin (NBN), which are associated with the DNA damage response. In HT patients, seven unique proteins were identified, among them long-chain fatty acid-CoA ligase (ASCL), which functions in the stimulation of triacylglycerol and cholesterol synthesis, and NADPH oxidase activator 1 (NOXA1), which is involved in high blood pressure via angiotensin II-induced reactive oxygen species (ROS)-generating systems. In coexisting T2DM/HT patients, six unique proteins were identified, of which two-microtubule-associated protein 1A (MAP1A)-might be involved in dementia via RhoB-p53 and diacylglycerol kinase beta (DGKB), associated with lipid metabolism. This study identified new candidate proteins that are possibly involved in the pathology of these diseases.

A Scoping Review of Population Diversity in the Common Genomic Aberrations of Clear Cell Renal Cell Carcinoma

INTRODUCTION

Previous literature has shown that clear cell renal cell carcinoma (ccRCC) is becoming a more prevalent diagnosis and that the incidence and mortality differ both regionally and racially. While the molecular profiles for ccRCC are studied regionally through biopsy and sequencing techniques, the genomic landscape and ccRCC diversity data are not well studied. We conducted a review of the known genomic data on 6 of the most clinically relevant DNA biomarkers in ccRCC: von Hippel-Lindau (vHL), Polybromo-1 (PBRM1), Breast Cancer Gene 1-Associated Protein 1 (BAP1), Histone-Lysine N-Methyltransferase Domain-Containing 2 (SETD2), Mammalian Target of Rapamycin (mTOR), and Lysine-Specific Demethylase 5C (KDM5C). The review compiled genomic diversity data, incidence, and risk factor differences by geographical and racial cohorts.

METHODS

The review methodology was created using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) principles from articles on PubMed and Embase through July 31, 2023, written and published in English, with diagnoses of primary or metastatic ccRCC via cytology or pathology, recorded the incidence of one or more of the 6 biomarkers, explored gene aberration via sequencing, were epidemiological in nature, and/or discussed basic science research, cohort studies, or retrospective studies.

RESULTS

Aberrations in vHL, PBRM1, and SETD2 driving ccRCC are studied frequently, but the data are heterogeneous, whereas there is a paucity in the data regarding KDM5C, PBRM1, and mTOR mutations.

CONCLUSION

Studying the genetic aberrations that frequently occur in different regions gives insight into what current research lacks. When more genomic landscape research arises, precision therapy, risk calculators, and artificial intelligence may help better prognosticate and individualize treatment for those at risk for ccRCC. Provided the scarcity of existing data, and the rising prevalence of ccRCC, more studies must be conducted at the clinical level.

INTRODUCTION

Previous literature has shown that clear cell renal cell carcinoma (ccRCC) is becoming a more prevalent diagnosis and that the incidence and mortality differ both regionally and racially. While the molecular profiles for ccRCC are studied regionally through biopsy and sequencing techniques, the genomic landscape and ccRCC diversity data are not well studied. We conducted a review of the known genomic data on 6 of the most clinically relevant DNA biomarkers in ccRCC: von Hippel-Lindau (vHL), Polybromo-1 (PBRM1), Breast Cancer Gene 1-Associated Protein 1 (BAP1), Histone-Lysine N-Methyltransferase Domain-Containing 2 (SETD2), Mammalian Target of Rapamycin (mTOR), and Lysine-Specific Demethylase 5C (KDM5C). The review compiled genomic diversity data, incidence, and risk factor differences by geographical and racial cohorts.

METHODS

The review methodology was created using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) principles from articles on PubMed and Embase through July 31, 2023, written and published in English, with diagnoses of primary or metastatic ccRCC via cytology or pathology, recorded the incidence of one or more of the 6 biomarkers, explored gene aberration via sequencing, were epidemiological in nature, and/or discussed basic science research, cohort studies, or retrospective studies.

RESULTS

Aberrations in vHL, PBRM1, and SETD2 driving ccRCC are studied frequently, but the data are heterogeneous, whereas there is a paucity in the data regarding KDM5C, PBRM1, and mTOR mutations.

CONCLUSION

Studying the genetic aberrations that frequently occur in different regions gives insight into what current research lacks. When more genomic landscape research arises, precision therapy, risk calculators, and artificial intelligence may help better prognosticate and individualize treatment for those at risk for ccRCC. Provided the scarcity of existing data, and the rising prevalence of ccRCC, more studies must be conducted at the clinical level.

Meta-analysis of the Relationship between Type 2 Diabetes Mellitus and Renal Cancer Risk

OBJECTIVE

This study aimed to investigate the relationship between type 2 diabetes mellitus and the risk of renal cancer.

METHODS

A search was carried out on PubMed, Embase, Web of Science, China Biology Medicine disc (CBM), China National Knowledge Infrastructure (CNKI), Wanfang and other databases. The search period was from 2000 to 2022. The two authors independently conducted literature screening, extracted literature data, and then conducted a literature quality evaluation. The type of study is a cohort study. Meta-analysis was carried out on the included literature through Stata12.0 software, and the combined value was calculated with RR value and 95% confidence interval. Subgroup analysis was carried out to explore the impact of different factors on the overall results.

RESULTS

A total of 10 articles were included. Through cohort study, the meta-analysis on the risk of type 2 diabetes and renal cancer showed that the combined effect value Risk Ratio (RR) = 1.57 with 95% Confidence Intervals (CI) (1.36, 1.82) and P<0.05. The difference had a significant impact, indicating that the risk of renal cancer in type 2 diabetes patients was 1.55 times higher than that in non-type 2 diabetes patients. The subgroup analysis showed that the combined effect value RR and 95% CI for men was 1.49 (1.26, 1.75), and the combined effect value RR and 95% CI for women was 1.60 (1.35, 1.88), which was basically consistent.

CONCLUSION

Type 2 diabetes can significantly increase the risk of renal cell carcinoma, and the former is a risk factor for the latter. It is suggested that multi-center studies with larger sample sizes should be conducted in the future, and adjustments should be made according to the type of diabetes, the source of the study population, the pathological type of renal cell carcinoma, the use of hypoglycemic drugs, and other factors, to provide a reliable basis for the study of the relationship between diabetes and renal cell carcinoma. At present, the specific mechanism of diabetes increasing the risk of renal cell carcinoma and whether diabetes increases mortality due to renal cell carcinoma is still unclear and needs further research.

Transcriptomics analyses reveal the effects of Pentagamaboronon-0-ol on PI3K/Akt and cell cycle of HER2+ breast cancer cells

Introduction

Monoclonal antibodies and targeted therapies against HER2+ breast cancer has improved overall and disease-free survival in patients; however, encountering drug resistance causes recurrence, necessitating the development of newer HER2-targeted medications. A curcumin analog PGB-0-ol showed most cytotoxicity against HCC1954 HER2+ breast cancer cells than against other subtypes of breast cancer cells.

Objective

Here, we employed next-generation sequencing technology to elucidate the molecular mechanism underlying the effect of PGB-0-ol on HCC1954 HER2+ breast cancer cells.

Methods

The molecular mechanism underlying the action of PGB-0-ol on HCC1954 HER2+ breast cancer cells was determined using next-generation sequencing technologies. Additional bioinformatics studies were performed, including gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, disease-gene, and drug-gene associations, network topology analysis (NTA), and gene set enrichment analysis (GSEA).

Results

We detected 2,263 differentially expressed genes (DEGs) (1,459 upregulated and 804 downregulated) in the PGB-0-ol- and DMSO-treated HCC1954 cells. KEGG enrichment data revealed the control of phosphatidylinositol signaling system, and ErbB signaling following PGB-0-ol treatment. Gene ontology (GO) enrichment analysis demonstrated that these DEGs governed cell cycle, participated in the mitotic spindle and nuclear membrane, and controlled kinase activity at the molecular level. According to the NTA data for GO enrichment, GSEA data for KEGG, drug-gene and disease-gene, PGB-0-ol regulated PI3K/Akt signaling and cell cycle in breast cancer. Overall, our investigation revealed the transcriptomic profile of PGB-0-ol-treated HCC1954 breast cancer cells following PGB-0-ol therapy. Bioinformatics analyses showed that PI3K/Akt signaling and cell cycle was modulated. However, further studies are required to validate the findings of this study.

Dietary glycemic index, glycemic load, and renal cancer risk: findings from prostate, lung, colorectal, and ovarian cancer trial

Background

Dietary glycemic index (GI) or glycemic load (GL) has been associated with the development of many cancers, but the evidence for renal cancer is still limited. The aim of the present study was to investigate the association between GI or GL and renal cancer risk in the Prostate, Lung, Colorectal, and Ovarian Cancer (PLCO) Screening Trial.

Methods

The cohort for our analysis consisted of 101,190 participants. GI and GL were calculated from the FFQ data using previously published reference values. Multivariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox regression model after adjusting for most known renal cancer risk factors.

Results

During a median of 12.2 years of follow-up, 443 incident renal cancer cases occurred. Higher dietary GI was significantly associated with a higher risk of renal cancer (HR_Q3vsQ1: 1.38; 95% CI: 1.09-1.74; p for trend = 0.008). There was no significant association between dietary GL and renal cancer risk (HR_Q3vsQ1 = 1.12, 95% CI = 0.79-1.59, p for trend = 0.591). Spline regression plot revealed a higher risk of renal cancer with a higher GI but not GL. There was no statistical evidence for nonlinearity (p for nonlinearity >0.05).

Conclusion

In summary, findings of this large-scale prospective cohort study suggested that dietary GI may be associated with the risk of renal cancer. If confirmed in other populations and settings, dietary GI could be considered as a modifiable risk factor for renal cancer prevention.

Trilateral association of autophagy, mTOR and Alzheimer's disease: Potential pathway in the development for Alzheimer's disease therapy

The primary and considerable weakening event affecting elderly individuals is age-dependent cognitive decline and dementia. Alzheimer's disease (AD) is the chief cause of progressive dementia, and it is characterized by irreparable loss of cognitive abilities, forming senile plaques having Amyloid Beta (Aβ) aggregates and neurofibrillary tangles with considerable amounts of tau in affected hippocampus and cortex regions of human brains. AD affects millions of people worldwide, and the count is showing an increasing trend. Therefore, it is crucial to understand the underlying mechanisms at molecular levels to generate novel insights into the pathogenesis of AD and other cognitive deficits. A growing body of evidence elicits the regulatory relationship between the mammalian target of rapamycin (mTOR) signaling pathway and AD. In addition, the role of autophagy, a systematic degradation, and recycling of cellular components like accumulated proteins and damaged organelles in AD, is also pivotal. The present review describes different mechanisms and signaling regulations highlighting the trilateral association of autophagy, the mTOR pathway, and AD with a description of inhibiting drugs/molecules of mTOR, a strategic target in AD. Downregulation of mTOR signaling triggers autophagy activation, degrading the misfolded proteins and preventing the further accumulation of misfolded proteins that inhibit the progression of AD. Other target mechanisms such as autophagosome maturation, and autophagy-lysosomal pathway, may initiate a faulty autophagy process resulting in senile plaques due to defective lysosomal acidification and alteration in lysosomal pH. Hence, the strong link between mTOR and autophagy can be explored further as a potential mechanism for AD therapy.

Duration of diabetes mellitus and risk of kidney and bladder cancer: a longitudinal nationwide cohort study

Previous studies have suggested that diabetes mellitus (DM) may increase the risk of kidney and bladder cancer; however, little is known about the duration of DM. We aimed to analyze the risk of kidney and bladder cancer according to the duration of DM in a longitudinal nationwide cohort. This study was conducted in a cohort of 9,773,462 participants ≥ 20 years old who underwent a National Health Examination in 2009 and were followed up until December 2017. Cox-proportional hazard models were used to evaluate the risk of kidney and bladder cancer in relation to the duration of DM. During follow-up (mean 7.3 years), kidney and bladder cancer occurred in 11,219 and 13,769 participants, respectively. DM was associated with an increased risk of kidney and bladder cancer (hazard ratio (HR), 95% confidence interval (95% CI); 1.14, 1.09-1.20 and 1.23, 1.17-1.28, respectively). Compared to fasting glucose < 100 mg/dL, impaired fasting glucose (IFG) and longer DM duration were associated with increased risks (HR, 95% CI): IFG (1.05, 1.01-1.10), new-onset DM (1.13, 1.03-1.24), DM < 5 years (1.11, 1.02-1.20), and DM ≥ 5 years (1.25, 1.15-1.36) in kidney cancer; IFG (1.05, 1.01-1.09), new-onset DM (1.10, 1.01-1.19), DM < 5 years (1.26, 1.18-1.35), and DM ≥ 5 years (1.34, 1.26-1.43) in bladder cancer, respectively. Our findings suggest that the subjects with IFG and longer duration of DM had a higher risk for kidney and bladder cancer than those without DM.

Versatile activity and morphological effects of zinc oxide submicron particles as anticancer agents

Background: Submicron particles (SMPs), as novel bionanomaterials, offer complementary benefits to their conventional nano-counterparts. Aim: To explore zinc oxide (ZnO) SMPs' bioimaging and anticancer potentials. Materials & methods: ZnO SMPs were synthesized into two shapes. Fluorescent spectrum and microscopy were studied for the bioimaging property. Wound healing and Live/Dead assays of glioblastoma cells were characterized for anticancer activities. Results: ZnO SMPs exhibited a high quantum yield (49%) with stable orange fluorescence emission. Both morphologies (most significant in the rod shape) showed tumor-selective properties in cytotoxicity, inhibition to cell migration and attenuating the cancer-upregulated genes. The tumor selectivity was attributed to particle degradation and surface properties on pH dependency. Conclusion: The authors propose that ZnO SMPs could be a promising anticancer drug with tunable, morphology-dependent properties for bioimaging and controlled release.

Effects of H2O2 Treatment Combined With PI3K Inhibitor and MEK Inhibitor in AGS Cells: Oxidative Stress Outcomes in a Model of Gastric Cancer

Gastric cancer is worldwide the fifth and third cancer for incidence and mortality, respectively. Stomach wall is daily exposed to oxidative stress and BER system has a key role in the defense from oxidation-induced DNA damage, whilst ErbB receptors have important roles in the pathogenesis of cancer. We used AGS cells as an aggressive gastric carcinoma cell model, treated with H2O2 alone or combined with ErbB signaling pathway inhibitors, to evaluate the effects of oxidative stress in gastric cancer, focusing on the modulation of ErbB signaling pathways and their eventual cross-talk with BER system. We showed that treatment with H2O2 combined with PI3K/AKT and MEK inhibitors influenced cell morphology and resulted in a reduction of cancer cell viability. Migration ability was reduced after H2O2 treatment alone or combined with MEK inhibitor and after PI3K/AKT inhibitor alone. Western blotting analysis showed that oxidative stress stimulated EGFR pathway favoring the MAPKs activation at the expense of PI3K/AKT pathway. Gene expression analysis by RT-qPCR showed ErbB2 and OGG1 increase under oxidative stress conditions. Therefore, we suggest that in AGS cells a pro-oxidant treatment can reduce gastric cancer cell growth and migration via a different modulation of PI3K and MAPKs pathways. Moreover, the observed ErbB2 and OGG1 induction is a cellular response to protect the cells from H2O2-induced cell death. In conclusion, to tailor specific combinations of therapies and to decide which strategy to use, administration of a chemotherapy that increases intracellular ROS to toxic levels, might not only be dependent on the tumor type, but also on the molecular targeting therapy used.

Dietary glycemic index, glycemic load and cancer risk: a meta-analysis of prospective cohort studies

PURPOSE

There is considerable inconsistency in results regarding the association of dietary glycemic index (GI) and glycemic load (GL) with cancer risk. We therefore conducted this systematic review and dose-response meta-analysis of prospective cohort studies to evaluate the relationship between dietary GI/GL and cancer risk.

METHODS

We searched PubMed and Web of Science for prospective cohort studies of dietary GI/GL in relation to risks of all types of cancer up to 31 March 2021. We used a random-effect model to calculate summary relative risks (RR) and 95% confidence intervals (CI). The certainty of evidence was assessed by the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. This study was registered at PROSPERO (CRD42020215338).

RESULTS

Overall, 55 cohorts were included in the meta-analysis. We assessed the relationship between dietary GI or GL and risks of 23 cancer types, including hormone-related cancers, cancers from digestive system, respiratory system, urinary system and other cancer sites. High GI diet increased overall risk of cancer with low certainty of evidence (highest vs lowest categories, n = 3, RR 1.04, 95% CI 1.01-1.07). For site-specific cancers, high GI diet increased risks of lung cancer (highest vs lowest categories, n = 5, RR 1.08, 95% CI 1.01-1.18) and breast cancer (highest vs lowest categories, n = 14, RR 1.05, 95% CI 1.01-1.09), especially for postmenopausal breast cancer (highest vs lowest categories, n = 10, RR 1.06, 95% CI 1.00-1.13), all with low certainty of evidence. Additionally, dietary GI was positively related to risk of bladder cancer with low certainty of evidence (highest vs lowest categories, n = 3, RR 1.23, 95% CI 1.09-1.40), as well as negatively related to ovarian cancer risk with very low certainty of evidence (highest vs lowest categories, n = 4, RR 0.83, 95% CI 0.69-1.00) and lymphoma risk with low certainty of evidence (highest vs lowest categories, n = 2, RR 0.84, 95% CI 0.72-0.98). Besides, we found an inverse association of dietary GL with lung cancer risk with low certainty of evidence (highest vs lowest categories, n = 5, RR 0.87, 95% CI 0.80-0.94).

CONCLUSION

High dietary GI increased overall cancer risk with low certainty of evidence. For site-specific cancers, high GI diet increased the risks of breast cancer with low certainty of evidence and lung cancer with low certainty of evidence. Dietary GL was inversely associated with lung cancer risk with low certainty of evidence.

TP63 Is Significantly Upregulated in Diabetic Kidney

The role of tumor protein 63 (TP63) in regulating insulin receptor substrate 1 (IRS-1) and other downstream signal proteins in diabetes has not been characterized. RNAs extracted from kidneys of diabetic mice (db/db) were sequenced to identify genes that are involved in kidney complications. RNA sequence analysis showed more than 4- to 6-fold increases in TP63 expression in the diabetic mice’s kidneys, compared to wild-type mice at age 10 and 12 months old. In addition, the kidneys from diabetic mice showed significant increases in TP63 mRNA and protein expression compared to WT mice. Mouse proximal tubular cells exposed to high glucose (HG) for 48 h showed significant decreases in IRS-1 expression and increases in TP63, compared to cells grown in normal glucose (NG). When TP63 was downregulated by siRNA, significant increases in IRS-1 and activation of AMP-activated protein kinase (AMPK (p-AMPK-Th¹⁷²)) occurred under NG and HG conditions. Moreover, activation of AMPK by pretreating the cells with AICAR resulted in significant downregulation of TP63 and increased IRS-1 expression. Ad-cDNA-mediated over-expression of tuberin resulted in significantly decreased TP63 levels and upregulation of IRS-1 expression. Furthermore, TP63 knockdown resulted in increased glucose uptake, whereas IRS-1 knockdown resulted in a decrease in the glucose uptake. Altogether, animal and cell culture data showed a potential role of TP63 as a new candidate gene involved in regulating IRS-1 that may be used as a new therapeutic target to prevent kidney complications in diabetes.

The Role of Metabolic Factors in Renal Cancers

An increasing number of evidence indicates that metabolic factors may play an important role in the development and progression of certain types of cancers, including renal cell carcinoma (RCC). This tumour is the most common kidney cancer which accounts for approximately 3-5% of malignant tumours in adults. Numerous studies indicated that concomitant diseases, including diabetes mellitus (DM) and hypertension, as well as obesity, insulin resistance, and lipid disorders, may also influence the prognosis and cancer-specific overall survival. However, the results of studies concerning the impact of metabolic factors on RCC are controversial. It appears that obesity increases the risk of RCC development; however, it may be a favourable factor in terms of prognosis. Obesity is closely related to insulin resistance and the development of diabetes mellitus type 2 (DM2T) since the adipocytes in visceral tissue secrete substances responsible for insulin resistance, e.g., free fatty acids. Interactions between insulin and insulin-like growth factor (IGF) system appear to be of key importance in the development and progression of RCC; however, the exact role of insulin and IGFs in RCC pathophysiology remains elusive. Studies indicated that diabetes increased the risk of RCC, but it might not alter cancer-related survival. The risk associated with a lipid profile is most mysterious, as numerous studies provided conflicting results. Even though large studies unravelling pathomechanisms involved in cancer growth are required to finally establish the impact of metabolic factors on the development, progression, and prognosis of renal cancers, it seems that the monitoring of health conditions, such as diabetes, low body mass index (BMI), and lipid disorders is of high importance in clear-cell RCC.

Dietary fiber, glycemic index, glycemic load and renal cell carcinoma risk

Several epidemiological studies have investigated the potential association between dietary fiber, glycemic index (GI) or glycemic load (GL), and renal cell carcinoma (RCC) risk with inconsistent results. The aim of this study was to systematically evaluate this issue with a meta-analysis approach. A comprehensive literature search up to March 2018 was performed in PubMed and Web of Science databases. Summary relative risks (RRs) and 95% confidence intervals (CIs) were estimated with a random-effects model. Twelve studies were finally included in this study (eight for fiber analysis, five for GI and five for GL). A significant positive association was observed between GI and the risk of RCC (summary RR 1.16, 95% CI 1.02-1.32), and no significant heterogeneity was detected among studies (I2 = 22.8%, P = 0.262). A significant inverse association was found between fiber intake and the risk of RCC (summary RR 0.82, 95% CI 0.72-0.92), and no significant heterogeneity was observed across studies (I2 = 27.6%, P = 0.218). GL was not significantly associated with RCC risk (summary RR 1.14, 95% CI 0.81-1.60), and significant heterogeneity was found across studies (I2 = 78.6%, P < 0.001). In conclusion, this systematic review and meta-analysis suggests that dietary GI and fiber may be associated with the risk of RCC. Further large prospective cohort studies are still warranted to confirm our preliminary findings.

Regulation of Microcystin-LR-Induced DNA Damage by miR-451a in HL7702 Cells

Microcystin-LR is a cyclic heptapeptide hepatotoxin produced by harmful cyanobacteria. A panel of microRNAs containing miR-451a were found to be significantly changed in normal human liver cells HL7702 after exposure to microcystin-LR (MC-LR) in our previous study. However, the functions of miR-451a in hepatotoxicity induced by MC-LR remained unclear. The study aimed to investigate the impacts of miR-451a in HL7702 cells following treatment with 5 or 10 μM MC-LR. The comet assay indicated that MC-LR can influence Olive tail moment (OTM) in HL7702 cells. Furthermore, increase of miR-451a significantly repressed DNA damage and the protein expression level of γ-H2AX induced by MC-LR. Moreover, over-expression of miR-451a inhibited the expression level of p-AKT1 protein in cells following treatment by MC-LR. These results showed that miR-451a may protect from MC-LR-induced DNA damage by down-regulating the expression of p-AKT1, which provides new clues for the diagnosis and therapy policies for liver damage induced by MC-LR.

Obesity, DNA Damage, and Development of Obesity-Related Diseases

Obesity has been recognized to increase the risk of such diseases as cardiovascular diseases, diabetes, and cancer. It indicates that obesity can impact genome stability. Oxidative stress and inflammation, commonly occurring in obesity, can induce DNA damage and inhibit DNA repair mechanisms. Accumulation of DNA damage can lead to an enhanced mutation rate and can alter gene expression resulting in disturbances in cell metabolism. Obesity-associated DNA damage can promote cancer growth by favoring cancer cell proliferation and migration, and resistance to apoptosis. Estimation of the DNA damage and/or disturbances in DNA repair could be potentially useful in the risk assessment and prevention of obesity-associated metabolic disorders as well as cancers. DNA damage in people with obesity appears to be reversible and both weight loss and improvement of dietary habits and diet composition can affect genome stability.

Oxidant and antioxidant levels and DNA damage in tuberous sclerosis

OBJECTIVE

The pathogenesis of inherited diseases is thought to involve oxidative stress and the associated DNA damage, which are also implicated in many other conditions including cancer. Tuberous sclerosis is a genetic disease with autosomal dominant inheritance pattern that is characterized by the development of hamartomas in multiple organ systems. Oxidative stress and the related DNA damage are also likely to play a significant role in the pathogenesis of this condition. Thus, our study aimed to assess total oxidant-antioxidant level, oxidative stress index and DNA damage in patients diagnosed with tuberous sclerosis.

METHODS

The study included 30 patients with tuberous sclerosis between the ages of 0 and 16 years. The control group consisted of 29 age-matched healthy children. Blood samples obtained from each subject were centrifuged to separate the sera. The Total Antioxidant Status (TAS) and Total Oxidant Status (TOS) were measured in serum samples with a Thermo Scientific Multiscan plate reader (FC, 2011-06, USA) at wavelengths of 240 nm and 520 nm, respectively. The measured TAS and TOS values were used to calculate the Oxidative Stress Index (OSI). In addition, the Comet Assay Method was used to determine DNA damage in the samples. Data were analyzed using SPSS software.

RESULTS

Patients with tuberous sclerosis complex (TSC) and controls were compared with respect to TAS, TOS, and OSI. TAS was significantly lower (p < 0.01), while TOS and OSI were significantly higher (p < 0.01, for both) in patients as compared to controls. In addition, patients had significantly higher DNA damage as shown by the Comet Assay (p < 0.01).

CONCLUSIONS

Increased oxidative stress and DNA damage may contribute to the pathogenesis of tuberous sclerosis.

miR‑122 and miR‑199 synergistically promote autophagy in oral lichen planus by targeting the Akt/mTOR pathway

The aim of the present study was to characterize the roles of two microRNAs (miRNAs), miR-122 and miR-199, in oral lichen planus (OLP). miRNA microarray analysis was performed to detect potential miRNAs involved in OLP, while in-silicon analysis, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blot and immunohistochemistry (IHC) analyses were utilized to explore the molecular mechanisms underlying the roles of miR-199 and miR-122 in OLP. The results from the microarray and RT-qPCR analyses demonstrated that the expression levels of miR-122 and miR-199 were significantly decreased in the peripheral blood mononuclear cells (PBMCs) collected from the OLP group compared with the control group. In addition, miR-122 and miR-199 directly targeted AKT serine/threonine kinase 1 (AKT1) and mammalian target of rapamycin (mTOR), respectively, by binding to their 3′ UTRs. AKT1 and mTOR were highly expressed in PBMCs derived from OLP patients. In fact, a negative regulatory relationship was observed between miR-122 and AKT1, and between miR-199 and mTOR, with negative correlation coefficients of −0.41 and −0.51, respectively. Furthermore, the protein levels of AKT1, mTOR and microtubule associated protein 1 light chain 3β (LC3B) were upregulated in the OLP group compared with the control group. Finally, overexpression of miR-122 inhibited the expression of AKT1 and LC3B, while overexpression of miR-199 reduced the levels of mTOR and LC3B. In conclusion, the present study demonstrated that miR-199 and miR-122 are implicated in the pathogenesis of OLP by regulating the expression of mTOR and AKT1.

Hormonal manipulation with finasteride or oral contraception does not influence incidence of renal cell carcinoma

Androgens have been suspected to be involved in the initiation of renal cell carcinoma because of a two-fold increased risk in men compared with women. To investigate the role of self-reported finasteride or oral contraceptive use in the Prostate, Lung, Colorectal, and Ovarian (PCLO) to determine whether the androgen receptor reduces renal cancer development. We query the PCLO trial for predictor variables from the baseline questionnaire and follow-up questionnaires enquiring medication use, specifically the use of 5-α reductase inhibitors (dutasteride or finasteride) and oral contraceptive therapy. The primary outcome of this study was the incidence of renal cancer. Statistical analysis included Student's t-test for continuous variables, χ, or Fisher's exact tests for dichotomous or categorical variables, and multivariable analysis using Cox proportional hazards models. Eight percent (n=6117/73 694) of men in the PCLO trial reported the use of finasteride. 52 (10.6%) of the 492 men diagnosed with renal cancer had self-reported exposure to finasteride and this was not significant in univariable analysis (52/6169; 0.84% vs. 440/66 454; 0.67%, P=0.12) or multivariable main effects analysis (hazard ratio: 1.12; 95% confidence interval: 0.83-1.5; P=0.47). Approximately 54% of women (n=40 997/75 989) in the PCLO trial reported the use of oral contraceptives by questionnaire. 136 (52.1%) of the 261 women diagnosed with renal cancer had self-reported exposure to oral contraceptive therapy and this was not significant in univariable analysis (136/40 997; 0.33% vs. 125/34 992; 0.36%, P=0.36) or in multivariable main effects analysis (hazard ratio: 1.03; 95% confidence interval: 0.97-1.1; P=0.30). Self-reported use of finasteride or oral contraceptives is not associated with a reduced incidence of renal cancer.

Galectin-1 is a new fibrosis protein in type 1 and type 2 diabetes

Chronic exposure of tubular renal cells to high glucose contributes to tubulointerstitial changes in diabetic nephropathy. In the present study, we identified a new fibrosis gene called galectin-1 (Gal-1), which is highly expressed in tubular cells of kidneys of type 1 and type 2 diabetic mouse models. Gal-1 protein and mRNA expression showed significant increase in kidney cortex of heterozygous Akita^+/- and db/db mice compared with wild-type mice. Mouse proximal tubular cells exposed to high glucose showed significant increase in phosphorylation of Akt and Gal-1. We cloned Gal-1 promoter and identified the transcription factor AP4 as binding to the Gal-1 promoter to up-regulate its function. Transfection of cells with plasmid carrying mutations in the binding sites of AP4 to Gal-1 promoter resulted in decreased protein function of Gal-1. In addition, inhibition of Gal-1 by OTX-008 showed significant decrease in p-Akt/AP4 and protein-promoter activity of Gal-1 and fibronectin. Moreover, down-regulation of AP4 by small interfering RNA resulted in a significant decrease in protein expression and promoter activity of Gal-1. We found that kidney of Gal-1^-/- mice express very low levels of fibronectin protein. In summary, Gal-1 is highly expressed in kidneys of type 1 and 2 diabetic mice, and AP4 is a major transcription factor that activates Gal-1 under hyperglycemia. Inhibition of Gal-1 by OTX-008 blocks activation of Akt and prevents accumulation of Gal-1, suggesting a novel role of Gal-1 inhibitor as a possible therapeutic target to treat renal fibrosis in diabetes.-Al-Obaidi, N., Mohan, S., Liang, S., Zhao, Z., Nayak, B. K., Li, B., Sriramarao, P., Habib, S. L. Galectin-1 is a new fibrosis protein in type 1 and type 2 diabetes.

mTOR signalling: jack-of-all-trades 1

The mechanistic target of rapamycin (mTOR) is an evolutionarily conserved serine/threonine kinase that senses and integrates environmental information into cellular regulation and homeostasis. Accumulating evidence has suggested a master role of mTOR signalling in many fundamental aspects of cell biology and organismal development. mTOR deregulation is implicated in a broad range of pathological conditions, including diabetes, cancer, neurodegenerative diseases, myopathies, inflammatory, infectious, and autoimmune conditions. Here, we review recent advances in our knowledge of mTOR signalling in mammalian physiology. We also discuss the impact of mTOR alteration in human diseases and how targeting mTOR function can treat human diseases.

Generation of TALEN-mediated FH knockout rat model

Transcription activator-like effector nucleases (TALENs) are valuable tools for precise genome engineering of laboratory animals. Here we utilized this technique for efficient site-specific gene modification to create a fumarate hydratase (FH) gene knockout rat model, in which there was an 11 base-pair deletion in the first exon of the FH gene in 111 rats. 18 live-born targeted mutation offsprings were produced from 80 injected zygotes with 22.5% efficiency, indicating high TALEN knockout success in rat zygots. Only heterozygous deletion was observed in the offsprings. Sixteen pairs of heterozygous FH knockout (FH+/−) rats were arranged for mating experiments for six months without any homozygous KO rat identified. Sequencing from the pregnant rats embryo samples showed no homozygous FH KO, indicating that homozygous FH KO is embryonically lethal. Comparatively, the litter size was decreased in both male and female FH+/− KO rats. There was no behaviour difference between the FH+/− KO and the control rats except that the FH+/− KO male rats showed significantly higher body weight in the 16-week observation period. Clinical haematology and biochemical examinations showed hematopoietic and kidney dysfunction in the FH+/− KO rats. Small foci of anaplastic lesions of tubular epithelial cells around glomeruli were identified in the FH+/− kidney, and these anaplastic cells were comparatively positive for Ki67, p53 and Sox9, and such findings are most probably related to the kidney dysfunction reflected by the biochemical examinations of the rats. In conclusion, we have successfully established an FH+/− KO rat model, which will be useful for further functional FH studies.

Advanced Glycation End Products Increase MDM2 Expression via Transcription Factor KLF5

Type 2 diabetes increases the risk for all-site cancers including colon cancer. Diabetic patients present typical pathophysiological features including an increased level of advanced glycation end products (AGEs), which comes from a series of nonenzymatic reactions between sugars and biological macromolecules, positively associated with the occurrence of diabetic complications. MDM2 is an oncogene implicated in cancer development. The present study investigated whether diabetes promoted MDM2 expression in colon cells and the underlying mechanisms. Our results showed that AGE increased the protein level of MDM2 in a cell model and promoted binding between MDM2 and Rb as well as p53, which led to degradation of Rb and p53. KLF5 was able to bind to the regulatory sequence of the MDM2 gene, and knockdown of the KLF5 protein level inhibited the AGE-triggered MDM2 overexpression, which indicated that KLF5 was the transcription factor for MDM2. In a mouse model of diabetes, we found that AGE level was increased in serum. The protein levels of both KLF5 and MDM2 were increased. KLF5 was able to bind to the regulatory sequence of the MDM2 gene. In conclusion, our results suggest that diabetes increases the level of AGE which enhances the expression of MDM2 via transcription factor KLF5 in colon cells. MDM2 overexpression is a candidate biological link between type 2 diabetes and colon cancer development.

Glycemic index, glycemic load and carbohydrate intake in association with risk of renal cell carcinoma

Carbohydrate intake affects postprandial glucose levels and insulin response, which plays a role in carcinogenesis. The relationship between carbohydrate intake, dietary glycemic index (GI) and glycemic load (GL), and risk of renal cell carcinoma (RCC) remains unclear. We conducted a case-control study including 854 patients with newly diagnosed RCC (cases) and 1255 healthy participants (controls) recruited since 2002. GI, GL and carbohydrate intake were obtained via a validated food frequency questionnaire. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariable logistic regression, adjusting for potential confounders. We found that higher GI was significantly associated with RCC risk with an OR of 1.32 (95% CI, 0.99-1.74; Ptrend = 0.026) (the highest versus the lowest quartiles). We also observed an inverse association between fiber intake and RCC risk with OR of 0.70 (95% CI = 0.50-0.99) as well as between starch intake and risk of RCC with OR of 0.65 (95% CI = 0.49-0.87). Individuals with a high-GI diet and hypertension or high body mass index (BMI) had a 2.7 times (OR = 2.67, 95% CI = 1.96-3.64) and two times (OR = 1.95, 95% CI = 1.29-2.92) higher RCC risk, respectively, than those without these factors. Our findings suggest that a high-GI diet is associated with an increased risk of RCC, whereas increased fiber and starch intakes appear to be associated with a decreased risk of RCC. We found that reducing GI levels and increasing fiber intake could be a dietary strategy to decrease RCC risk, especially for individuals with hypertension or high BMI.

Resveratrol-mediated apoptosis in renal cell carcinoma via the p53/AMP‑activated protein kinase/mammalian target of rapamycin autophagy signaling pathway

Resveratrol, known as phytoalexin, is a natural compound. Clinical studies have revealed that resveratrol has a variety of effects including anti‑inflammatory, antivirus and tumor suppressor activities. It has been reported that it may serve an important role in renal cell carcinoma (RCC) however, the molecular mechanism underlying resveratrol‑induced apoptosis in RCC is still unclear. The aim of the present study was to determine whether resveratrol could suppress RCC progression. Analysis of apoptosis demonstrated that resveratrol may act as a RCC suppressor in a dose‑ and time‑dependent manner. In addition, the results of the MTT and cell migration experiments revealed that resveratrol significantly decreased cell viability and migration. In addition, the expression of the anti‑apoptosis gene B‑cell lymphoma 2 (Bcl‑2) was downregulated by resveratrol, and the expression of pro‑apoptosis gene Bcl‑2‑associated X was upregulated at the mRNA and protein levels. Resveratrol also promoted the expression of p53 and activated phospho‑AMP‑activated protein kinase (AMPK). The phosphorylation of mammalian target of rapamycin (mTOR) was inhibited and the autophagy‑associated genes, light chain 3, autophagy related (ATG)5 and ATG7, were upregulated at the mRNA and protein levels. In conclusion, resveratrol suppressed RCC viability and migration, and promoted RCC apoptosis via the p53/AMPK/mTOR‑induced autophagy signaling pathway.

MicroRNA-26a inhibits the growth and invasiveness of malignant melanoma and directly targets on MITF gene

Metastatic melanoma is the most aggressive form of skin cancer and is refractory to therapy. MicroRNAs have been recently discovered as novel molecules that provide therapeutic benefits against melanoma. This work aims to examine the effects of miR-26a and let-7a on the growth and invasiveness of malignant melanoma in vitro and in vivo. In addition, we elucidate the mechanism of action by identifying the target gene of miR-26a. Both miR-26a and let-7a inhibited proliferation and invasiveness and halted the cell cycle at the G₁/G₀ phase in SKMEL-28 and WM1552C malignant melanoma cell lines. Moreover, miR-26a potently induced apoptosis and downregulated the expressions of microphthalmia-associated transcription factor (MITF) and MAP4K3 in both cell lines. The luciferase reporter assay demonstrated that miR-26a suppresses MITF expression by binding the 3′-UTR, suggesting that MITF is a bona fide target of miR-26a. SiRNA knockdown of the MITF gene confirmed that miR-26a reduced cell viability and induced apoptosis by regulating MITF. Using a murine model, we also found miR-26a significantly retarded the growth of melanoma tumors in vivo. In conclusion, miR-26a and let-7a suppressed the growth and invasiveness of melanoma cells, suggesting that miR-26a and let-7a may represent novel therapies for malignant melanoma.

Formation and repair of oxidatively generated damage in cellular DNA

In this review article, emphasis is placed on the critical survey of available data concerning modified nucleobase and 2-deoxyribose products that have been identified in cellular DNA following exposure to a wide variety of oxidizing species and agents including, hydroxyl radical, one-electron oxidants, singlet oxygen, hypochlorous acid and ten-eleven translocation enzymes. In addition, information is provided about the generation of secondary oxidation products of 8-oxo-7,8-dihydroguanine and nucleobase addition products with reactive aldehydes arising from the decomposition of lipid peroxides. It is worth noting that the different classes of oxidatively generated DNA damage that consist of single lesions, intra- and interstrand cross-links were unambiguously assigned and quantitatively detected on the basis of accurate measurements involving in most cases high performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry. The reported data clearly show that the frequency of DNA lesions generated upon severe oxidizing conditions, including exposure to ionizing radiation is low, at best a few modifications per 106 normal bases. Application of accurate analytical measurement methods has also allowed the determination of repair kinetics of several well-defined lesions in cellular DNA that however concerns so far only a restricted number of cases.

Klotho, an antiaging molecule, attenuates oxidant-induced alveolar epithelial cell mtDNA damage and apoptosis

Alveolar epithelial cell (AEC) apoptosis and inadequate repair resulting from "exaggerated" lung aging and mitochondrial dysfunction are critical determinants promoting lung fibrosis. α-Klotho, which is an antiaging molecule that is expressed predominantly in the kidney and secreted in the blood, can protect lung epithelial cells against hyperoxia-induced apoptosis. We reasoned that Klotho protects AEC exposed to oxidative stress in part by maintaining mitochondrial DNA (mtDNA) integrity and mitigating apoptosis. We find that Klotho levels are decreased in both serum and alveolar type II (AT2) cells from asbestos-exposed mice. We show that oxidative stress reduces AEC Klotho mRNA and protein expression, whereas Klotho overexpression is protective while Klotho silencing augments AEC mtDNA damage. Compared with wild-type, Klotho heterozygous hypomorphic allele (kl/+) mice have increased asbestos-induced lung fibrosis due in part to increased AT2 cell mtDNA damage. Notably, we demonstrate that serum Klotho levels are reduced in wild-type but not mitochondrial catalase overexpressing (MCAT) mice 3 wk following exposure to asbestos and that EUK-134, a MnSOD/catalase mimetic, mitigates oxidant-induced reductions in AEC Klotho expression. Using pharmacologic and genetic silencing studies, we show that Klotho attenuates oxidant-induced AEC mtDNA damage and apoptosis via mechanisms dependent on AKT activation arising from upstream fibroblast growth factor receptor 1 activation. Our findings suggest that Klotho preserves AEC mtDNA integrity in the setting of oxidative stress necessary for preventing apoptosis and asbestos-induced lung fibrosis. We reason that strategies aimed at augmenting AEC Klotho levels may be an innovative approach for mitigating age-related lung diseases.

The ribosomal protein S6 in renal cell carcinoma: functional relevance and potential as biomarker

Inhibitors of the mTOR pathway, such as everolimus, are promising compounds to treat patients with renal cell carcinomas (RCCs). However, the precise mechanisms of action are far from clear, and biomarkers predicting the response to mTOR inhibitors are still missing. Here, we provide evidence that in RCCs the rpS6 protein is the major mediator of anti-tumoral effects exerted by everolimus. Inhibition of mTOR signaling results in substantially decreased clonogenicity and proliferation of RCC cells, but did not significantly induce apoptosis. Everolimus effectively blocked protein biosynthesis both in vitro and in a novel ex vivo tissue slice model using fresh vital human RCC tissue. Compared to other components of the mTOR pathway, phosphorylation of rpS6 was most effectively downregulated by everolimus. Importantly, siRNA-mediated downregulation of rpS6, but not of 4ebp1 or p27, abolished the inhibitory effects of everolimus on proliferation and protein synthesis. Moreover, we analyzed the tissue expression of phosphorylated rpS6 (p-rpS6) and non-phosphorylated rpS6 in a large collection of patients with RCCs (n=598 and n=548, respectively). Expression of both proteins qualified as independent negative prognostic markers with a substantially shorter survival of patients with RCCs exhibiting high levels of rpS6 and p-rpS6. Taken together, our functional studies identified rpS6 as a main mediator of the anti-tumoral activity of Everolimus. Therefore, further (pre-)clinical evaluations of rpS6 as a predictive marker for everolimus-based treatment for RCC patients are warranted. Finally, the combined detection of phosphorylated and non-phosphorylated rpS6 could represent a robust prognostic marker to identify patients with high risk RCCs.

Evidence for DNA damage as a biological link between diabetes and cancer

Objective:

This review examines the evidence that: Diabetes is a state of DNA damage; pathophysiological factors in diabetes can cause DNA damage; DNA damage can cause mutations; and DNA mutation is linked to carcinogenesis.

Data Sources:

We retrieved information from the PubMed database up to January, 2014, using various search terms and their combinations including DNA damage, diabetes, cancer, high glucose, hyperglycemia, free fatty acids, palmitic acid, advanced glycation end products, mutation and carcinogenesis.

Study Selection:

We included data from peer-reviewed journals and a textbook printed in English on relationships between DNA damage and diabetes as well as pathophysiological factors in diabetes. Publications on relationships among DNA damage, mutagenesis, and carcinogenesis, were also reviewed. We organized this information into a conceptual framework to explain the possible causal relationship between DNA damage and carcinogenesis in diabetes.

Results:

There are a large amount of data supporting the view that DNA mutation is a typical feature in carcinogenesis. Patients with type 2 diabetes have increased production of reactive oxygen species, reduced levels of antioxidant capacity, and increased levels of DNA damage. The pathophysiological factors and metabolic milieu in diabetes can cause DNA damage such as DNA strand break and base modification (i.e., oxidation). Emerging experimental data suggest that signal pathways (i.e., Akt/tuberin) link diabetes to DNA damage. This collective evidence indicates that diabetes is a pathophysiological state of oxidative stress and DNA damage which can lead to various types of mutation to cause aberration in cells and thereby increased cancer risk.

Conclusions:

This review highlights the interrelationships amongst diabetes, DNA damage, DNA mutation and carcinogenesis, which suggests that DNA damage can be a biological link between diabetes and cancer.

Insulin and IGFs in renal cancer risk and progression

Insulin and IGFs play a significant role in cancer development and progression, including renal cell carcinoma (RCC). RCC is the most frequent type of kidney cancer in adults and the tenth most common malignancy worldwide. Insulin is normally associated with metabolism control, whereas IGFs are defined as proliferation regulators. Today, there is convincing evidence of an association between obesity and the risk of RCC. Indicated risk factors together with type 2 diabetes are irreversibly connected with circulating insulin and IGF levels. The interplay between these molecules, their receptors, and IGF-binding proteins might be crucial for RCC cell biology and RCC progression. Given the potent activity IGF/IGF receptor 1 (IGF1R) inhibitors demonstrate against RCC in basic research, some type of combination therapy may prove to be beneficial clinically in the management of RCC. This review addresses not only molecular but also clinical associations between insulin and IGF1 signaling pathways and both RCC biology and clinical course. Revealing these interactions may improve our understanding of basic molecular oncology processes in RCC and improve treatment strategies.

The Impact of Diabetes Mellitus on Renal Cell Carcinoma Prognosis: A Meta-Analysis of Cohort Studies

Previous studies that investigated the relationship between DM and survival in renal cell carcinoma (RCC) patients reported inconsistent findings. Hence, we conducted a meta-analysis to obtain a more precise evaluation of the prognostic significance of DM in RCC. A systematic review was conducted with PubMed, Embase, and Web of Science to identify relevant articles that evaluated the effect of DM on RCC patients. Based on the inclusion and quality assessment criteria, 18 studies were eligible for the meta-analysis. Pooled hazard ratios (HR) and corresponding 95% confidence intervals (CI) for overall survival (OS), cancer-specific survival (CSS), and recurrence-free survival (RFS) were calculated by standard meta-analysis techniques. The results suggested that DM was associated with poor OS (HR 1.56, 95% CI, 1.35-1.81, P < 0.001), poor CSS (HR 2.03, 95% CI, 1.37-3.01, P < 0.001), and poor RFS (HR 1.73, 95% CI, 1.25-2.39, P = 0.012). In addition, for patients with localized RCC, patients with clear cell RCC, or patients receiving nephrectomy, DM was associated with both poor OS and CSS by subgroup analyses. Our study revealed that there was a significant negative impact of DM on OS, CSS, and RFS in RCC patients. Therefore, more attention should be paid to RCC patients with preexisting DM because of their poor prognosis.

Novel mechanism of transcriptional regulation of cell matrix protein through CREB

The transcription mechanism(s) of renal cell matrix accumulation in diabetes does not explored. Phosphorylation of the transcription factor cAMP-responsive element binding protein (CREB) significantly increased in cells treated with high glucose (HG) compared to cell grown in normal glucose (NG). Cells pretreated with rapamycin before exposure to HG showed significant decrease phosphorylation of CREB, increase in AMPK activity and decrease protein/mRNA and promoter activity of fibronectin. In addition, cells transfected with siRNA against CREB showed significant increase in AMPK activity, decrease in protein/mRNA and promoter activity of fibronectin. Cells treated with HG showed nuclear localization of p-CREB while pretreated cells with rapamycin reversed HG effect. Moreover, gel shift analysis shows increase binding of CREB to fibronectin promoter in cells treated with HG while cells pretreated with rapamycin reversed the effect of HG. Furthermore, db/db mice treated with rapamycin showed significant increase in AMPK activity, decrease in expression of p-CREB and protein/mRNA of fibronectin. Strong staining of fibronectin and p-CREB was detected in kidney cortex of db/db mice while treated mice with rapamycin reversed hyperglycemia effect. In summary, our data provide a novel mechanism of transcriptional regulation of fibronectin through CREB that may be used as therapeutic approach to prevent diabetes complications.

Wood dust exposure induces cell transformation through EGFR-mediated OGG1 inhibition

A high risk of neoplastic transformation of nasal and paranasal sinuses mucosa is related to the occupational exposure to wood dust. However, the role of occupational exposures in the aetiology of the airway cancers remains largely unknown. Here, an in vitro model was performed to investigate the carcinogenic effect of wood dusts. Human bronchial epithelial cells were incubated with hard and soft wood dusts and the DNA damage and response to DNA damage evaluated. Wood dust exposure induced accumulation of oxidised DNA bases, which was associated with a delay in DNA repair activity. By exposing cells to wood dust at a prolonged time, wood dust-initiated cells were obtained. Initiated-cells were able to form colonies in soft agar, and to induce blood vessel formation. These cells showed extensive autophagy, reduced DNA repair, which was associated with reduced OGG1 expression and oxidised DNA base accumulation. These events were found related to the activation of EGFR/AKT/mTOR pathway, through phosphorylation and subsequent inactivation of tuberin. The persistence in the tissue of wood dusts, their repetitious binding with EGFR may continually trigger the activation switch, leading to chronic down-regulation of genes involved in DNA repair, leading to cell transformation and proliferation.

Activation of mTOR: a culprit of Alzheimer's disease?

Alzheimer's disease (AD) is characterized by cognitive impairment in clinical presentation, and by β-amyloid (Aβ) production and the hyper-phosphorylation of tau in basic research. More highlights demonstrate that the activation of the mammalian target of rapamycin (mTOR) enhances Aβ generation and deposition by modulating amyloid precursor protein (APP) metabolism and upregulating β- and γ-secretases. mTOR, an inhibitor of autophagy, decreases Aβ clearance by scissoring autophagy function. mTOR regulates Aβ generation or Aβ clearance by regulating several key signaling pathways, including phosphoinositide 3-kinase (PI3-K)/protein kinase B (Akt), glycogen synthase kinase 3 [GSK-3], AMP-activated protein kinase (AMPK), and insulin/insulin-like growth factor 1 (IGF-1). The activation of mTOR is also a contributor to aberrant hyperphosphorylated tau. Rapamycin, the inhibitor of mTOR, may mitigate cognitive impairment and inhibit the pathologies associated with amyloid plaques and neurofibrillary tangles by promoting autophagy. Furthermore, the upstream and downstream components of mTOR signaling are involved in the pathogenesis and progression of AD. Hence, inhibiting the activation of mTOR may be an important therapeutic target for AD.