Helicobacter pylori (H pylori) is a gram negative bacterium which infects about 50% of the world population. H pylori colonization causes a strong systemic immune response. Various tools have been employed to identify the relationship between H pylori and gastric cancer, including c-DNA microarrays. However, most of these methods did not consider the systematic interaction of biological components.
A research team from South Korea studied the complex reaction of gastric inflammation induced by Helicobacter pylori (H pylori) in a systematic manner using a protein interaction network. Their study will be published on September 28, 2009 in the World Journal of Gastroenterology.
The results showed that the scale-free network showing the relationship between inflammation and carcinogenesis was constructed. Mathematical analysis showed hub and bottleneck proteins, and these proteins were mostly related to immune response. The network contained pathways and proteins related to H pylori infection, such as the JAK-STAT pathway triggered by interleukins. Activation of nuclear factor (NF)-kB, TLR4, and other proteins known to function as core proteins of immune response were also found. These immune-related proteins interacted on the network with pathways and proteins related to the cell cycle, cell maintenance and proliferation, and transcription regulators such as BRCA1, FOS, REL, and zinc finger proteins. The extension of nodes showed interactions of the immune proteins with cancer-related proteins. One extended network, the core network, a summarized form of the extended network, and cell pathway model were constructed.
The researchers drew a conclusion that immune-related proteins activated by H pylori infection interact with proto-oncogene proteins. The hub and bottleneck proteins are potential drug targets for gastric inflammation and cancer.
Their study showed how a systematic approach such as the network construction produces meaningful information. It also offered a relatively easy and simple framework to understand the complexity of cellular interactions having functional importance. Therefore, the application of this tool may be an alternative to find important genes and drug targets in other diseases and in complex biological systems.
Reference: Kim KK, Kim HB. Protein interaction network related to Helicobacter pylori infection response. World J Gastroenterol 2009; 15(36): 4518-4528
Correspondence to: Dr. Han Bok Kim, Professor, Department of Biotechnology, The Research Institute for Basic Sciences, Hoseo University, Asan 336-795, South Korea.
About World Journal of Gastroenterology
World Journal of Gastroenterology (WJG), a leading international journal in gastroenterology and hepatology, has established a reputation for publishing first class research on esophageal cancer, gastric cancer, liver cancer, viral hepatitis, colorectal cancer, and H pylori infection and provides a forum for both clinicians and scientists. WJG has been indexed and abstracted in Current Contents/Clinical Medicine, Science Citation Index Expanded (also known as SciSearch) and Journal Citation Reports/Science Edition, Index Medicus, MEDLINE and PubMed, Chemical Abstracts, EMBASE/Excerpta Medica, Abstracts Journals, Nature Clinical Practice Gastroenterology and Hepatology, CAB Abstracts and Global Health. ISI JCR 2008 IF: 2.081. WJG is a weekly journal published by WJG Press. The publication dates are the 7th, 14th, 21st, and 28th day of every month. WJG is supported by The National Natural Science Foundation of China, No. 30224801 and No. 30424812, and was founded with the name of China National Journal of New Gastroenterology on October 1, 1995, and renamed WJG on January 25, 1998.