Epsilon-aminocaproic acid prevents high glucose and insulin induced-invasiveness in MDA-MB-231 breast cancer cells, modulating the plasminogen activator system

Single-Cell Protein and Transcriptional Characterization of Epiretinal Membranes From Patients With Proliferative Vitreoretinopathy

Purpose

Proliferative vitreoretinopathy (PVR) remains an unresolved clinical challenge and can lead to frequent revision surgery and blindness vision loss. The aim of this study was to characterize the microenvironment of epiretinal PVR tissue, in order to shed more light on the complex pathophysiology and to unravel new treatment options.

Methods

A total of 44 tissue samples were analyzed in this study, including 19 epiretinal PVRs, 13 epiretinal membranes (ERMs) from patients with macular pucker, as well as 12 internal limiting membranes (ILMs). The cellular and molecular microenvironment was assessed by cell type deconvolution analysis (xCell), RNA sequencing data and single-cell imaging mass cytometry. Candidate drugs for PVR treatment were identified in silico via a transcriptome-based drug-repurposing approach.

Results

RNA sequencing of tissue samples demonstrated distinct transcriptional profiles of PVR, ERM, and ILM samples. Differential gene expression analysis revealed 3194 upregulated genes in PVR compared with ILM, including FN1 and SPARC, which contribute to biological processes, such as extracellular matrix (ECM) organization. The xCell and IMC analyses showed that PVR membranes were composed of macrophages, retinal pigment epithelium, and α-SMA-positive myofibroblasts, the latter predominantly characterized by the co-expression of immune cell signature markers. Finally, 13 drugs were identified as potential therapeutics for PVR, including aminocaproic acid and various topoisomerase-2A inhibitors.

Conclusions

Epiretinal PVR membranes exhibit a unique and complex transcriptional and cellular profile dominated by immune cells and myofibroblasts, as well as a variety of ECM components. Our findings provide new insights into the pathophysiology of PVR and suggest potential targeted therapeutic options.

Prevention of High Glucose-Mediated EMT by Inhibition of Hsp70 Chaperone

Hyperglycemia may contribute to the progression of carcinomas by triggering epithelial-to-mesenchymal transition (EMT). Some proteostasis systems are involved in metastasis; in this paper, we sought to explore the mechanism of Hsp70 chaperone in EMT. We showed that knockdown of Hsp70 reduced cell migration capacity concomitantly with levels of mRNA of the Slug, Snail, and Twist markers of EMT, in colon cancer cells incubated in high glucose medium. Conversely, treatment of cells with Hsp70 inducer U-133 were found to elevate cell motility, along with the other EMT markers. To prove that inhibiting Hsp70 may reduce EMT efficiency, we treated cells with a CL-43 inhibitor of the HSF1 transcription factor, which lowered Hsp70 and HSF1 content in the control and induced EMT in carcinoma cells. Importantly, CL-43 reduced migration capacity, EMT-linked transcription factors, and increased content of epithelial marker E-cadherin in colon cancer cells of three lines, including one derived from a clinical sample. To prove that Hsp70 chaperone should be targeted when inhibiting the EMT pathway, we treated cancer cells with 2-phenylethynesulfonamide (PES) and demonstrated that the compound inhibited substrate-binding capacity of Hsp70. Furthermore, PES suppressed EMT features, cell motility, and expression of specific transcription factors. In conclusion, the Hsp70 chaperone machine efficiently protects mechanisms of the EMT, and the safe inhibitors of the chaperone are needed to hamper metastasis at its initial stage.

Determination of Epsilon Aminocaproic Acid Based on Charge Transfer Complexation with p-Nitrophenlol by Spectrophotometry

Introduction:

Spectrophotometry was investigated for the determination of epsilon aminocaproic acid (EACA) with p-nitrophenol (PNP). The method was based on Charge Transfer (CT) complexation of this drug as n-electron donor with π-acceptor PNP.

Methods:

The experiment indicated that CT complexation was carried out at room temperature for 10 minutes in dimethyl sulfoxide solvent. The spectrum obtained for EACA/PNP system showed the maximum absorption band at a wavelength of 425 nm. The stoichiometry of the CT complex was found to be a 1:1 ratio by Job’s method between the donor and the acceptor. Different variables affecting the complexation were carefully studied and optimized. At the optimum reaction conditions, Beer’s law was obeyed in a concentration limit of 1～6 μg mL-1. The relative standard deviation was less than 2.9%. The apparent molar absorptivity was determined to be 1.86×104 L mol-1cm-1 at 425 nm. The CT complexation was also confirmed by both FTIR and 1H NMR measurements.

Results:

The thermodynamic properties and reaction mechanism of the CT complexation have been discussed.

Conclusion:

The developed method could be applied successfully for the determination of the studied compound in its pharmaceutical dosage forms with good precision and accuracy compared to the official method comprising t- and F-tests.

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.

Epithelial Mesenchymal Transition and Progression of Breast Cancer Promoted by Diabetes Mellitus in Mice Are Associated with Increased Expression of Glycolytic and Proteolytic Enzymes

The development of breast cancer (BC) is influenced by age, overweight, obesity, metabolic syndrome, and diabetes mellitus (DM), which are associated with hyperglycemia, glucose intolerance, insulin resistance, and oxidative stress. High glucose concentration increases a metastatic phenotype in cultured breast cancer cells, promoting cell proliferation, reactive species production (ROS), epithelial mesenchymal transition (EMT), and expression of proteolytic enzymes. Our aim was to determine whether diabetes mellitus favor BC progression in mice and its association with changes in the content of ROS and glycolytic and proteolytic enzymes. Diabetes was induced in 7-week-old Balb/c mice, under 6-h fasting with a unique i. p. dose of streptozotocin 120 mg/kg. Furthermore, 4T1 breast cancer cells were injected beneath the nipple to induce tumors. G6PD, GAPDH, ENO1, uPA, uPAR, PAI-1, β-catenin, Snail, vimentin, and E-cadherin were measured by western blot and MPP-9 and MMP-2 by gel zymography. TBARS were measured as markers of the lipid peroxidation. Lower survival and increased tumor growth, together with marked EMT, were found in diabetic in comparison with nondiabetic mice. The effects of diabetes were associated with enhanced lipid peroxidation and higher levels of glycolytic (G6PD, GAPDH, and ENO1) and proteolytic (uPA, MMP-9) enzymes. Possibly, hyperglycemia and ROS led to faster progression of breast cancer in diabetic mice, fomenting EMT and the expression of glycolytic and proteolytic enzymes. These enzymes participate in the supply of energy and precursors for macromolecular biosynthesis and extracellular matrix degradation during breast cancer progression.

Effects of hyperglycemia on the progression of tumor diseases

Malignant tumors are often multifactorial. Epidemiological studies have shown that hyperglycemia raises the prevalence and mortality of certain malignancies, like breast, liver, bladder, pancreatic, colorectal, endometrial cancers. Hyperglycemia can promote the proliferation, invasion and migration, induce the apoptotic resistance and enhance the chemoresistance of tumor cells. This review focuses on the new findings in the relationship between hyperglycemia and tumor development.

Featured Species-Specific Loops Are Found in the Crystal Structure of Mhp Eno, a Cell Surface Adhesin From Mycoplasma hyopneumoniae

Enolase is an evolutionarily conserved enzyme involved in the processes of glycolysis and gluconeogenesis. Mycoplasma hyopneumoniae belongs to Mycoplasma, whose species are wall-less and among the smallest self-replicating bacteria, and is an important colonizing respiratory pathogen in the pig industry worldwide. Mycoplasma hyopneumoniae enolase (Mhp Eno) expression is significantly increased after infection and was previously found to be a virulence factor candidate. Our studies show that Mhp Eno is a cell surface-localized protein that can adhere to swine tracheal epithelial cells (STECs). Adhesion to STECs can be specifically inhibited by an Mhp Eno antibody. Mhp Eno can recognize and interact with plasminogen with high affinity. Here, the first crystal structure of the mycoplasmal enolase from Mycoplasma hyopneumoniae was determined. The structure showed unique features of Mhp Eno in the S3/H1, H6/S6, H7/H8, and H13 regions. All of these regions were longer than those of other enolases and were exposed on the Mhp Eno surface, making them accessible to host molecules. These results show that Mhp Eno has specific structural characteristics and acts as a multifunctional adhesin on the Mycoplasma hyopneumoniae cell surface.