Elevated expression of semaphorin 5A in human gastric cancer and its implication in carcinogenesis.
OBJECTIVE
Semaphorin 5A, a member of semaphorin family, was originally identified as axonal guidance factor functioning during neuronal development. Here, we investigated semaphorin 5A expression in gastric cancer and explored its roles in gastric carcinogenesis.


METHODS
The expression of semaphorin 5A was examined by reverse transcription-polymerase chain reaction (RT-PCR) analysis in six gastric cancer cell lines and detected by real-time RT-PCR and Western blotting in 30 pairs of primary gastric cancer and normal gastric mucosa tissues. RNA interference (RNAi) technique was used to generate a semaphorin 5A-silenced stable cell line. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and anchorage-independent growth as well as flow cytometry assays were conducted to examine the effect of siRNA-semaphorin 5A on gastric cancer cell growth, proliferation and apoptosis.


RESULTS
Semaphorin 5A was expressed in all human gastric cancer lines and the expression of semaphorin 5A was significantly higher in cancer tissues than that in normal mucosa tissues. siRNA-mediated semaphorin 5A knockdown significantly suppressed the proliferation and anchorage-independent growth, and induced the apoptosis of gastric cancer cell line SGC7901.


CONCLUSIONS
The present study suggests that overexpression of semaphorin 5A may contribute to gastric carcinogenesis, which reveals a novel expression and function of semaphorin 5A outside the nervous system and adds more weight to our knowledge of semaphorin 5A.
Pan
Guoqing
G
Department of Pathology, Xiangya Medical College, Central South University, Changsha, Hunan, PR China.
Lv
Hui
H
Ren
Hongzheng
H
Wang
Ying
Y
Liu
Ying
Y
Jiang
Haiying
H
Wen
Jifang
J
D017209:Apoptosis; D015153:Blotting, Western; D018929:Cell Culture Techniques; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D005434:Flow Cytometry; D005753:Gastric Mucosa / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D010957:Plasmids; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D039961:Semaphorins; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology; D014162:Transfection; D015854:Up-Regulation
D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D034741:RNA, Small Interfering; C491228:SEMA5A protein, human; D039961:Semaphorins