■半乳糖凝集素-3(gal-3,基因名称:LGALS3)密码子64处单核苷酸多态性(SNP)rs4644,将变体脯氨酸(P64)指定为组氨酸(H64),已知会影响蛋白质的功能,并且与几种癌症的风险有关,包括分化型甲状腺癌(DTC)。
■为了加深我们对这种SNP的生物学效应的理解,我们分析了两个等基因细胞系的蛋白质组(NC-P64与NA-H64)源自永生化非恶性甲状腺细胞系Nthy-Ori,通过CRISPR-Cas9技术产生的差异在于rs4644基因型。我们比较了这些细胞的蛋白质组以检测差异表达的蛋白质,并研究了它们的蛋白质组与其转录组的关系。
■首先,我们发现,与以前的研究一致,gal-3-H64可以作为单体被检测到,同二聚体,和异二聚体由一个切割的和一个未切割的单体组成,而gal-3-P64只能作为单体或未切割的同二聚体发现。此外,结果表明,rs4644影响几种蛋白质的表达,在NA-H64细胞中主要上调。总的来说,差异蛋白表达可归因于mRNA表达的改变,这表明rs4644塑造了gal-3作为转录共调节因子的功能。然而,与mRNA表达相比,该SNP似乎也影响其表达受到相反调控的蛋白质的转录后调控机制.可以想象,gal-3的rs4644依赖性活性可以归因于自二聚化的不同方式。
■我们的研究提供了进一步的证据,表明rs4644可以通过几种途径影响gal-3功能,这可能是对疾病易感性不同的基础,病例对照关联研究报告。
UNASSIGNED: The single nucleotide polymorphism (SNP) rs4644 at codon 64 of galectin-3 (gal-3, gene name: LGALS3), specifying the variant proline (P64) to histidine (H64), is known to affect the protein\'s functions and has been associated with the risk of several types of cancer, including differentiated thyroid carcinoma (DTC).
UNASSIGNED: To deepen our understanding of the biological effects of this SNP, we analyzed the proteome of two isogenic cell lines (NC-P64 vs. NA-H64) derived from the immortalized non-malignant thyrocyte cell line Nthy-Ori, generated through the CRISPR-Cas9 technique to differ by rs4644 genotype. We compared the proteome of these cells to detect differentially expressed proteins and studied their proteome in relation to their transcriptome.
UNASSIGNED: Firstly, we found, consistently with previous studies, that gal-3-H64 could be detected as a monomer, homodimer, and heterodimer composed of one cleaved and one uncleaved monomer, whereas gal-3-P64 could be found only as a monomer or uncleaved homodimer. Moreover, results indicate that rs4644 influences the expression of several proteins, predominantly upregulated in NA-H64 cells. Overall, the differential protein expression could be attributed to the altered mRNA expression, suggesting that rs4644 shapes the function of gal-3 as a transcriptional co-regulator. However, this SNP also appeared to affect post-transcriptional regulatory mechanisms for proteins whose expression was oppositely regulated compared to mRNA expression. It is conceivable that the rs4644-dependent activities of gal-3 could be ascribed to the different modalities of self-dimerization.
UNASSIGNED: Our study provided further evidence that rs4644 could affect the gal-3 functions through several routes, which could be at the base of differential susceptibility to diseases, as reported in case-control association studies.