Background
Human inter-α-trypsin inhibitor heavy chain 4 (ITIH4) is an acute phase response protein that is positively regulated by interleukin-6 (IL-6), suggesting that ITIH4 can be used as an early serological biomarker of gastric cancer.
Conclusions
The detection of ITIH4 and IL-6 during H. pylori infection may be useful for the screening of early gastric cancer.
Methods
The mechanism of ITIH4 elevation in gastric cancer cells was investigated via Helicobacter pylori (H. pylori) with or without recombinant human interleukin-6 (rhIL-6) in human gastric cell line AGS cells. The messenger RNA (mRNA) expressions of ITIH4 and IL-6 in AGS cells were detected with real-time quantitative polymerase chain reaction (qPCR), while the expression of ITIH4 protein and IL-6 in AGS cells was detected with Western blot and enzyme-linked immunosorbent assay (ELISA) methods.
Results
We found that the mRNA and protein expressions of ITIH4 started to increase synchronously at 3 hours (h), peaked at 12 h, and then declined to normal a level at 24 h in AGS cells after H. pylori infection. Interestingly, the expression patterns of ITIH4 were positively correlated to IL-6 expression levels. In the ITIH4 expression experiment with IL-6 administration, the expression level of ITIH4 began to increase at a concentration of 6.25 ng/mL with rhIL-6 administration, reach a peak, and plateau at a concentration of 25 ng/mL of rhIL-6. The expression patterns of ITIH4 in AGS cells induced by H. pylori infection were closely related to the infection of H. pylori and the level of IL-6. Conclusions: The detection of ITIH4 and IL-6 during H. pylori infection may be useful for the screening of early gastric cancer.