Background: 5-fluorouracil (5-FU) is widely used in the treatment of gastric and colorectal cancer. Recent microrarray studies associated different gene lists with 5-FU resistance. A major challenge in the genomic era is to find the most validated genes, and to decipher the regulatory networks responsible for the expression changes in a set of co-regulated transcripts. Our aim was to find genes repeatedly associated with 5-FU resistance, and to identify transcription factors (TFs) having overrepresented binding sites (TFBSs) in the promoter regions of genes associated with 5-FU resistance.
Materials And Methods: The analyzed data originated from 5 different publications describing genome-wide gene expression patterns associated with 5- FU resistance in gastric and colorectal cancer. First, a data warehouse containing all genes associated with resistance was set up. 39 genes were identified which were repeatedly associated with resistance. Of these, using the EZ-Retrieve web service, proximal promoter sequences were available for 33 genes. The MotifScanner software was used to detect TFBSs in this set of sequences.
Results: A total of 200 different TFBSs were identified. Using the statistics tool of the Java program TOUCAN, 4 binding sites were found to be significantly overrepresented: NFKappaB50 (p = 0.01), EGR2 (p = 0.027), EGR3 (p = 0.007), and NGFIC (or EGR4) (p = 0.001). These genes intercept apoptotic pathways at multiple locations in the tumor cells.
Conclusion: We identified a consensus gene list associated with 5-FU resistance, performed an in silico comparative promoter analysis, and highlighted the potential implication of some TFs in the development of chemoresistance.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1159/000104490 | DOI Listing |
Arab J Gastroenterol
January 2025
Fourth Oncology Department, Anyang Tumor Hospital, Anyang City, Henan Province 455000, China. Electronic address:
Background And Study Aims: Nicotinamide N-methyltransferase (NNMT) is aberrantly expressed in tumors and is implicated in the progression and chemoresistance of cancers. This project attempts to explore the specific molecular mechanism by which NNMT enhances 5-fluorouracil (5-FU) resistance in gastric cancer (GC).
Materials And Methods: By bioinformatics analysis, the expression of NNMT in GC was analyzed and its relationship with patients' prognoses was examined.
Sci Rep
January 2025
Department of Colorectal Surgery, Clinical Oncology School of Fujian Medical University, Fuzhou, 350004, Fujian, Fujian, P.R. China.
J Cancer
January 2025
The Colorectal and Anal Surgery Department of Shanxi Provincial People's Hospital, Shanxi Medical University, Taiyuan, China.
Thymidylate synthase (TYMS) is a key regulatory enzyme in DNA synthesis. We identified the biological effect and molecular mechanisms of TYMS in colorectal cancer (CRC). We employed western blot and immunohistochemistry for the assessment of TYMS expression in CRC samples.
View Article and Find Full Text PDFTheranostics
January 2025
State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan Province, People's Republic of China.
Dysfunctional tumor vasculature, hypoxia, and an immunosuppressive microenvironment are significant barriers to effective cancer therapy. Autophagy, which is critical for maintaining cellular homeostasis and apoptosis resistance, is primarily triggered by hypoxia and nutrient deprivation, conditions prevalent in dysfunctional tumor vessels due to poor circulation. However, the role of autophagy in dysfunctional tumor endothelial cells and its impact on treatment and the tumor microenvironment (TME) remain poorly understood.
View Article and Find Full Text PDFJ Biochem
January 2025
Laboratory of Anticancer Strategies, Advanced Research Initiative, Institute of Science Tokyo, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!