Sialylated glycoproteins and sialyltransferases in digestive cancers: Mechanisms, diagnostic biomarkers, and therapeutic targets.

Sialic acid (SA), as the ultimate epitope of polysaccharides, can act as a cap at the end of polysaccharide chains to prevent their overextension. Sialylation is the enzymatic process of transferring SA residues onto polysaccharides and is catalyzed by a group of enzymes known as sialyltransferases (SiaTs). It is noteworthy that the sialylation level of glycoproteins is significantly altered when digestive cancer occurs. And this alteration exhibits a close correlation with the progression of these cancers. In this review, from the perspective of altered SiaTs expression levels and changed glycoprotein sialylation patterns, we summarize the pathogenesis of gastric cancer (GC), colorectal cancer (CRC), pancreatic ductal adenocarcinoma (PDAC), and hepatocellular carcinoma (HCC). Furthermore, we propose potential early diagnostic biomarkers and prognostic indicators for different digestive cancers. Finally, we summarize the therapeutic value of sialylation in digestive system cancers.

Effect of procyanidins on lipid metabolism and inflammation in rats exposed to alcohol and iron.

BACKGROUND: Lifestyle involving uncontrolled alcohol consumption coupled regularly with red meat and other iron sources has detrimental effects on the liver, which in the long term, results in Alcoholic Liver Disease (ALD). Procyanidin has lately garnered increasing attention and has become the focus of research owing to its antioxidant properties. This study explores the anti-inflammatory effects of procyanidins, in preventing ALD, by analyzing the biological activities of the compound on liver injury caused by excessive alcohol and iron. METHOD: Male SPF Wistar rats were placed in 4 groups; the control Group A (basic diet); the model Group B (excess alcohol 8-12 mL/kg/d and iron 1000 mg/kg diet); the low dose procyanidin Group C (model group diet plus 60 mg/kg/d of procyanidin); and the high dose procyanidin Group D (model group diet plus 120 mg/kg/d of procyanidin). Serum biochemical markers for liver damage were measured spectrophotometrically. The NFκB and IκB mRNA expression levels were determined using RT-PCR; the NFκB p65 and IκB protein expression levels were assessed via western blotting, while ELISA was used to detect serum inflammatory factors. RESULTS: The pathological score of the model Group B, low and high dose procyanidin Groups C and D were 6.58 ± 0.90,4.69 ± 0.70 and 2.00 ± 0.73, respectively (P < 0.05). The results showed that high alcohol and iron contents in the model group led to significant damage of liver structure, increased low-density lipoproteins (LDLs), steatosis, and increased levels of inflammatory cytokines. High amounts of procyanidins led to the preservation of the liver structure, production of high-density lipoproteins, and reduction in serum inflammatory cytokines while also significantly decreasing the expression levels of NFκB p65. CONCLUSION: The results prove that procyanidins have hepatoprotective potential and could be effective in reversing histopathology, possibly by alleviating inflammation and improving lipid metabolism.