Mass spectrometrical analysis of the processed metastasis-inducing anterior gradient protein 2 homolog reveals 100% sequence coverage

Hypomethylation-Mediated AGR2 Overexpression Facilitates Cell Proliferation, Migration, and Invasion of Lung Adenocarcinoma

Objective

Studies have indicated that AGR2 is crucial in many cancers. However, its methylation level in lung adenocarcinoma (LUAD) is rarely known. Hence, the effect of AGR2 methylation on LUAD was explored in the study.

Methods

qRT-PCR was adopted to detect the expression of AGR2 in LUAD cells and normal lung cells. Methylation-specific PCR (MSP) was used to detect the methylation of AGR2 promoter region in different cell lines. MTT, Transwell and wound healing assays were used to verify the progression of cells in each transfection group.

Results

The expression of AGR2 was significantly up-regulated in LUAD cells relative to that in normal cells. Moreover, the expression of AGR2 was inversely modulated by DNA methylation, and the hypomethylation of CpG islands would lead to the increased expression of AGR2. Finally, overexpression and hypomethylation of AGR2 facilitated the proliferation, invasion and migration of LUAD cells.

Conclusion

These results demonstrated that hypomethylation of AGR2 promoter region promoted the expression of AGR2 in LUAD cells, thus promoting the progression of LUAD cells.

Analysis of mutually exclusive alternatively spliced serpin-1 isoforms and identification of serpin-1 proteinase complexes in Manduca sexta hemolymph

Mutually exclusive alternative splicing produces transcripts for 12 serpin-1 isoforms in Manduca sexta that differ only in the region encoding the carboxyl-terminal 36-40-amino acid residues. This variable region includes the reactive center loop, which determines the inhibitory selectivity of the serpin. We investigated mRNA levels of individual serpin-1 isoforms by quantitative PCR. The 12 isoforms were expressed at similar levels in hemocytes, but in fat body isoform B mRNA was present at significantly higher levels than isoforms C, D, E, F, G, J, K, and Z. To investigate the presence of individual serpin-1 isoforms in plasma we used immunoaffinity purification of serpin-1 isoforms from M. sexta plasma, followed by two-dimensional PAGE and identification of protein spots by digestion with a series of proteinases and analysis of the resulting peptides by MALDI-TOF/TOF. We identified nine of the 12 serpin-1 isoforms and, through analysis of putative serpin-1-proteinase complexes, identified three endogenous M. sexta proteinase targets of serpin-1. Our results suggest that M. sexta serpin-1 isoforms A, E, and J can inhibit hemolymph proteinase 8, which activates the cytokine spätzle. At least one isoform of serpin-1 can inhibit hemocyte proteinase 1, another M. sexta blood proteinase. In addition, a complex of serpin-1K in a complex with M. sexta midgut chymotrypsin was identified, suggesting serpin-1 isoforms may also function to protect insect tissues from digestive proteinases that may leak into the hemocoel.