Preliminary Study On The Differential Expression Of Transcription Factors In Lung Adenocarcinoma And Adjacent Lung Tissues

Objective The aim of this study is to enrich the transcription factors of 30 cases of lung adenocarcinoma and adjacent tissues by a concatenated tandem array of the consensus transcription factor response elements(catTFRE), dynamic description and quantitative analysis of the differentially expressed transcription factors, and explore the biological processes, signaling pathways which regulated by transcription factors.Methods The present invention is enrichment and separation transcription factors use of sequence-specific transcription factors and DNA element binding characteristics, design and synthesis of a series of multiple copies of various transcription factor binding element of double-stranded DNA, and then Molecular cloning techniques through DNA binding both ends of the element in each biotin-labeled double-stranded DNA arm, forming a "DNA bait", during the separation and purification of transcription factors, purified good biotinylated DNA bait coupled to streptavidin-coated magnetic beads, then incubated with good nucleoprotein pre-prepared, isolated and purified after washing and endogenous transcription factor complex from nucleoprotein. Finally, depending on the application purpose of the follow-up can be further identified by mass spectrometry and functional analysis of transcription factors. After getting the results of mass spectrometry, we use the method of the “Intensity based absolute quantification”(iBAQ) to assess the amount of change in protein expression between cancer tissue and adjacent tissue, to identify the differentially expressed transcription factors. Bioinformatics analysis of the differentially expressed transcription factors by Gene Ontology(GO), Kyoto Encyclopedia of Genes and Genomes(KEGG) and protein-protein interactions(PPI), to explore the biological processes, signaling pathways and protein-protein interaction networks in the regulation of these transcription factors.Results The results of lung adenocarcinoma tissues of mass spectrometry are as follows: the average utilization of mass spectrometry scanning spectrum>50%, through a database search, get high confidence peptides number is 7340-10527, the average high confidence peptides number is 9841; the number of proteins identified is 1420-2512, the average number of proteins is 1863(specific peptides≥1), containing 123-330 transcription factors, average 184 kinds of transcription factors; The results of lung adjacent tissues of mass spectrometry are as follows: the average utilization of mass spectrometry scanning spectrum> 50%, through a database search, get high confidence peptides number is 6918-9588, the average high confidence peptides number is 8390; the number of proteins identified is 1389-2478, the average number of proteins is 1688(specific peptides≥1), containing 112-278 transcription factors, average 162 kinds of transcription factors. There are 154 kinds of differential expression of transcription factors which are up-regulation, and 86 kinds of transcription factors are down-regulation.The biological processes regulated by differential expression of transcription factors are enriched by GO, mainly including: 1.regulation of RNA biosynthetic process; 2. regulation of RNA metabolic process; 3. regulation of cellular macromolecule biosynthetic process; 4. transcription, DNA-templated; 5. regulation of macromolecule biosynthetic process; 6. RNA biosynthetic process; 7. transcription from RNA polymerase II promoter; 8. regulation of cellular biosynthetic process; 9. regulation of biosynthetic process; 10. regulation of gene expression. In addition, biological processes are significantly enriched further comprises: cell differentiation, tissue development, regulation of cell differentiation, epithelium development, cell proliferation, regulation of cell proliferation, immune system development, cell death, regulation of cell death and regulation of apoptotic process.The signaling pathways regulated by differential expression of transcription factors are enriched by KEGG mainly including: 1. Transcriptional misregulation in cancer; 2. Hepatitis B; 3. Pathways in cancer; 4. Thyroid cancer; 5. Acute myeloid leukemia; 6. HTLV-I infection; 7.Osteoclast differentiation; 8. Prostate cancer; 9. Viral carcinogenesis; 10. Wnt signaling pathway. Besides, the signaling pathways are significantly enriched also including: Non-small cell lung cancer, TNF signaling pathway, Small cell lung cancer, Cell cycle.PPI analysis of differential expression of transcription factor JUN is in a "(hub)" position in the protein- protein interaction network,, JUN can interact with a variety of transcription factors, involved in multiple signaling pathways.Conclusion CatTFRE can enrich the transcription factors effectively of lung adenocarcinoma tissues and adjacent tissues. Bioinformatics analysis of the differentially expressed transcription factors by GO, KEGG and PPI to explore some of these differences in biological processes, signaling pathways, and transcription factor which is in the “hub”position--JUN, which can provide some important evidence and important basis for the further study of lung adenocarcinoma. Alao, it will be helpful to explain the relationship between transcription factors and the development of lung adenocarcinoma, and contribute to a more complete and truly evidence to reveal the pathogenesis of lung adenocarcinoma.