Cancer progression is linked to aberrant protein glycosylation due to the overexpression of several glycosylation enzymes. These enzymes are underexploited as potential anticancer drug targets and the development of rapid-screening methods and identification of glycosylation inhibitors are highly sought. An integrated bioinformatics and mass spectrometry-based glycomics-driven glycoproteomics analysis pipeline was performed to identify an N-glycan inhibitor against lung cancer cells. Combined network pharmacology and in silico screening approaches were used to identify a potential inhibitor, pictilisib, against several glycosylation-related proteins, such as Alpha1-6FucT, GlcNAcT-V, and Alpha2,6-ST-I. A glycomics assay of lung cancer cells treated with pictilisib showed a significant reduction in the fucosylation and sialylation of N-glycans, with an increase in high mannose-type glycans. Proteomics analysis and in vitro assays also showed significant upregulation of the proteins involved in apoptosis and cell adhesion, and the downregulation of proteins involved in cell cycle regulation, mRNA processing, and protein translation. Site-specific glycoproteomics analysis further showed that glycoproteins with reduced fucosylation and sialylation were involved in apoptosis, cell adhesion, DNA damage repair, and chemical response processes. To determine how the alterations in N-glycosylation impact glycoprotein dynamics, modeling of changes in glycan interactions of the ITGA5–ITGB1 (Integrin alpha 5-Integrin beta-1) complex revealed specific glycosites at the interface of these proteins that, when highly fucosylated and sialylated, such as in untreated A549 cells, form greater hydrogen bonding interactions compared to the high mannose-types in pictilisib-treated A549 cells. This study highlights the use of mass spectrometry to identify a potential glycosylation inhibitor and assessment of its impact on cell surface glycoprotein abundance and protein–protein interaction.
Diabetes mellitus, a complex chronic disease that is associated with hyperglycemia (high blood sugar) affects millions of people worldwide. This study evaluated the hypoglycemic activities of male and female Antidesma bunius, commonly known as currant tree or bignay, extracts in alloxan-treated ICR mice. In addition, the effects of the treatments on blood urea nitrogen (BUN) and creatinine levels were determined. Phytochemical screening using standard protocol was performed. Plant extracts (500 mg/kg) were administered orally via gavage for 14 days and fasting blood glucose (FBG) levels were monitored prior to alloxan-induction on the day of alloxan-induction, and on the 3rd, 7th and 14th days of treatment. Sera were collected on the 14th day to measure the BUN and creatinine levels. Phytochemical screening was performed using standard TLC spray tests. All extracts were found to significantly lower FBG levels compared to the positive (glibenclamide 10 mg/kg) and negative (distilled water) controls (One-way ANOVA, p-value<0.0001). The most active extract, aqueous male A. bunius extract, significantly lowered FBG levels by as much as 61.26±17.89% after the 14th day (paired t-test, p-value = 0.0211). Both BUN and creatinine values were found to be significantly different in the treated mice compared to the controls (One-way ANOVA, p-value = 0.0005 and 0.000479, respectively). The BUN level of all mice was still within normal range, unlike with the creatinine level where only the female and male aqueous A. bunius and female ethanolic A. bunius extracts were within normal range. Phytochemical screening showed the presence of saponins, tannins, and polyphenols, phlobatannins, steroids and terpenoids. This study demonstrates the potential of male and female A. bunius leaf extracts to reduce fasting blood glucose levels. Additional work, pertaining to the identification of possible bioactive compounds and establishing the mechanisms thereof, could be performed.
Annona muricata L. (Guyabano) leaves are reported to exhibit anticancer activity against cancer cells. In this study, the ethyl acetate extract from guyabano leaves was purified through column chromatography, and the cytotoxic effects of the semi-purified fractions were evaluated against A549 lung cancer cells using in vitro MTS cytotoxicity and scratch/wound healing assays. Fractions F15-16C and F15-16D exhibited the highest anticancer activity in the MTS assay, with % cytotoxicity values of 99.6% and 99.4%, respectively. The bioactivity of the fractions was also consistent with the results of the scratch/wound healing assay. Moreover, untargeted metabolomics was employed on the semi-purified fractions to determine the putative compounds responsible for the bioactivity. The active fractions were processed using LC-MS/MS analysis with the integration of the following metabolomic tools: MS-DIAL (for data processing), MetaboAnalyst (for data analysis), GNPS (for metabolite annotation), and Cytoscape (for network visualization). Results revealed that the putative compounds with a significant difference between active and inactive fractions in PCA and OPLS-DA models were pheophorbide A and diphenylcyclopropenone.
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