9037

SEMA5A

sema domain, seven thrombospondin repeats (type 1 and type 1-like), transmembrane domain (TM) and short cytoplasmic domain, (semaphorin) 5A;SEMA5A;sema domain, seven thrombospondin repeats (type 1 and type 1-like), transmembrane domain (TM) and short cytoplasmic domain, (semaphorin) 5A

sema F|semaphorin 5A|semaphorin F|semaphorin-5A|semaphorin-F

5p15.2

protein-coding

Semaphorin 5A, a member of semaphorin family, was originally identified as axonal guidance factor functioning during neuronal development. Previously, we showed that the expression of semaphorin 5A might contribute to the metastasis of gastric cancer. However, its functional roles and mechanism(s) in invasion and metastasis of gastric cancer remain unclear. By using human gastric caner cell lines Parental SGC7901, SGC7901-siScrambled and SGC7901-siSema 5A, we found that semaphorin 5A significantly promoted the invasive and metastatic abilities of gastric cancer cell in vitro. Semaphorin 5A increased the expression of MMP9 by activating phosphorylated ErK1/2 in gastric cancer cell. Furthermore, MEK inhibitor PD98059 and MMP9 antibody (Ab) significantly inhibited in vitro invasive and metastatic abilities induced by semaphorin 5A. Taken together, the present work revealed a novel function of semaphorin 5A that the existence of semaphorin 5A could promote invasion and metastasis of gastric cancer by regulating MMP9 expression, at least partially, via the MEK/ERKs signal transduction pathway. Semaphorin 5A and its regulated molecules could be the potential targets for cancer therapy.

Semaphorin 5A (SEMA5A) is an axonal regulator molecule, which belongs to the Semaphorin family of proteins. Previously, we identified SEMA5A as a putative marker for aggressive pancreatic tumors. However, the expression, localization and functional significance of SEMA5A in pancreatic tumors remain unclear. In our study, we hypothesized that SEMA5A expression modulates pancreatic tumor growth and metastasis. We analyzed the constitutive expression and localization of SEMA5A in patient pancreatic tumors (n = 33) and unmatched normal pancreatic (n = 8) tissues and human pancreatic cancer cell lines (n = 16) with different histopathological characteristics. We observed significantly higher expression of SEMA5A protein expression (p < 0.05) in human pancreatic tumor tissue samples compared to normal pancreatic tissues. Similarly, the pancreatic cancer cell lines with higher tumorigenic and metastatic potentials as xenografts in nude mice expressed higher levels of SEMA5A mRNA compared to those with lower tumorigenic and metastatic potentials. Furthermore, we examined the functional role of SEMA5A in pancreatic tumor growth and invasion. Ectopic expression of mouse full-length Sema5A in Panc1 (SEMA5A negative) cells significantly (p < 0.05) enhanced tumorigenesis, growth and metastasis in vivo as well as proliferation, invasiveness and homotypic aggregation in vitro. Together, these data demonstrate that the expression of SEMA5A in pancreatic cancer cells regulates tumorigenesis, growth, invasion and metastasis, and it also suggests a novel target for diagnosis and treatment of pancreatic cancer.