Glioma Diagnosis and Treatment (2)COVID-19 and healthcare impacts (2)Brain Metastases and Treatment (2)Cancer Treatment and Pharmacology (2)COVID-19 Impact on Reproduction (2)
Unhealthy diets (e.g., higher red meat consumption) and tobacco exposure are major risk factors for colorectal cancer (CRC), contributing the toxic substances exposure of polycyclic aromatic hydrocarbons (PAHs). However, the genetic regulation of PAHs metabolism-related genes involved in CRC susceptibility remains unexplored. To address this gap, we performed a meta-analysis using cross-ancestry genome-wide data, including East Asian populations (Chinese: N = 1150, N = 1342; Japanese: N = 6692, N = 27,178) and European (N = 78,473, N = 107,143) to evaluate the genetic association of 47 PAHs-metabolism-related genes with CRC risk. Expression patterns were derived from Nanjing ColoRectal Cancer cohort (NJCRC) and public datasets, including a total of 828 bulk RNA-Seq samples, 62 samples for cell-type-specific expression samples, and 50 paired protein validation samples. Finally, we observed that rs7927381 C > T in GSTP1 was associated with reduced CRC risk (odds ratio (OR) = 0.94, 95% confidence interval (CI) = 0.92-0.96, P = 1.90 × 10). Intriguingly, it downregulated the GSTP1 expression specifically in plasmablast cells. This effect may be attributed to its location in the DNA-hypersensitive regulatory region with enhancer and promoter activity, which could alter transcription factor binding. Notably, both GSTP1 mRNA and protein level were upregulated in CRC tissues, suggesting its elevation may influence PAHs metabolism through the oxidative phosphorylation and ribosome biological processes, promoting carcinogenesis. In conclusion, we identified GSTP1 rs7927381 as a cross-ancestry genetic variant affecting CRC risk through influencing PAHs metabolizing, offering new insights into the genetic mechanisms underlying CRC.
Sugars are necessary for plant growth and fruit development. Cucumber (Cucumis sativus L.) transports sugars, mainly raffinose family oligosaccharides (RFOs), in the vascular bundle. As the dominant sugars in cucumber fruit, glucose and fructose are derived from sucrose, which is the product of RFO hydrolysis by α-galactosidase (α-Gal). Here, we characterized the cucumber alkaline α-galactosidase 2 (CsAGA2) gene and found that CsAGA2 has undergone human selection during cucumber domestication. Further experiments showed that the expression of CsAGA2 increases gradually during fruit development, especially in fruit vasculature. In CsAGA2-RNA interference (RNAi) lines, fruit growth was delayed because of lower hexose production in the peduncle and fruit main vascular bundle (MVB). In contrast, CsAGA2-overexpressing (OE) plants displayed bigger fruits. Functional enrichment analysis of transcriptional data indicated that genes related to sugar metabolism, cell wall metabolism, and hormone signaling were significantly downregulated in the peduncle and fruit MVBs of CsAGA2-RNAi plants. Moreover, downregulation of CsAGA2 also caused negative feedback regulation on source leaves, which was shown by reduced photosynthetic efficiency, fewer plasmodesmata at the surface between mesophyll cell and intermediary cell (IC) or between IC and sieve element, and downregulated gene expression and enzyme activities related to phloem loading, as well as decreased sugar production and exportation from leaves and petioles. The opposite trend was observed in CsAGA2-OE lines. Overall, we conclude that CsAGA2 is essential for cucumber fruit set and development through mediation of sugar communication between sink strength and source activity.
A water-soluble glucomannogalactan was isolated from P. geesteranus fruit bodies by hot water extraction and column chromatography method. The structure, chain conformation and immune effect of PGP-1c (20.9 kDa) were investigated comprehensively based on high purity and neutral sugar content (94.7 ± 0.5%). Confirmed by monosaccharide composition, methylation and NMR analysis, PGP-1c was composed of unsubstituted (1,6-α-Gal and 1,6-α-3-OMe-Gal) and monosubstituted (1,2,6-α-Gal and 1,2,6-α-3-OMe-Gal) galactose units in the backbone through α-(1 → 6) glycosidic bonds and the possible branches that a long-branched chain composed of →3)-Glc-(1 → Man and a few fucoses were connected at the O-2 of galactose with a branching degree of 48%. Through the conformational behavior of the molecular chain, it was observed that PGP-1c might have a long-branched or stacked macromolecular network caused by O-CH groups. Moreover, PGP-1c could promote the secretion of NO and cytokines significantly in a dose-dependent manner, which indicated a good immune-enhancing effect.