Abstract:

Background and purpose: Esophageal cancer is a serious disease threatening human health, and it is very difficult to understand the development mechanism and find the therapeutic methods for esophageal cancer. In recent years, B7-H3, as a new member of B7 immunoregulatory superfamily, overexpressed in multiple tumor types, is considered to be a new tumor marker and potential therapeutic target. This study aimed to detect the expression of B7-H3 in esophageal cancer cell lines TE-1, TE-13, Eca-109 and exploring the effect of B7-H3 siRNA on cell proliferation, migration and invasion in vitro in human esophageal cancer Eca-109 cell line. Methods: The expression of B7-H3 in esophageal cancer cell lines TE-1, TE-13 and Eca-109 were detected by reverse transcription polymerase chain reaction (RT-PCR). B7-H3 siRNA and control siRNA were transfected in vitro into human esophageal cancer Eca-109 cells using LipofectamineTM 2000. The expressions of B7-H3 mRNA and protein in Eca-109 cells were analyzed by RT-PCR and Western blot. The proliferation, migration and invasion abilities of Eca-109 cells were measured by MTT assay, wound scrape assay and transwell invasion assay in vitro, respectively. Results: All tested cultured esophageal cancer cell lines constitutively expressed B7-H3 mRNA under normal conditions (TE-1 0.382±0.008, TE-13 0.399±0.008, Eca-109 0.428±0.012). After transfection, the expression of B7-H3 mRNA levels decreased in B7-H3 siRNA transfected group, compared with control siRNA transfected group (0.128 5±0.000 2 vs 0.532 4±0.000 7, P<0.01) and untransfected group (0.128 5±0.000 2 vs 0.540 3±0.001 3, P<0.01), while its protein expression levels were also significantly lower than the control transfection group (0.421 4±0.004 8 vs 0.500 6±0.012 9, P<0.05) and untransfected group (0.421 4±0.004 8 vs 0.492 1±0.014 8, P<0.05). Compared with control transfected and untransfected cells, Eca-109 cell migration and invasion abilities decreased significantly (P<0.05) by siRNA interference, but no significant difference was observed between their proliferative capacity (P>0.05). Conclusion: All tested esophageal cancer cell lines constitutively express B7-H3 mRNA. B7-H3 siRNA interference inhibits Eca-109 cell migration and invasion abilities. B7-H3 may have a critical role in regulating Eca-109 cell progression.

Key words: Costimulatory molecule, B7-H3, Esophageal cancer, Eca-109