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

P0.01) and untransfected group (0.128 5±0.000 2 vs 0.540 3±0.001 3

P0.01)

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

P0.05) and untransfected group (0.421 4±0.004 8 vs 0.492 1±0.014 8

P0.05). Compared with control transfected and untransfected cells

Eca-109 cell migration and invasion abilities decreased significantly (P0.05) by siRNA interference

but no significant difference was observed between their proliferative capacity (P0.05). 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.