Semaphorin-3F (SEMA3F) is a member of semaphorins family. All the family members have a secretion signal, a 500-amino acid sema domain, and 16 conserved cysteine residues. Semaphorins not only guide axons in development, but also have major roles in immune function (classes 4, 6, and 7) and the development of bones. Class 3 semaphorins are one of the most versatile semaphorin classes, in which Sema3a is the most studied. Besides, SEMA3F is deleted or downregulated in many metastatic tumors. To test the effect of SEMA3F on inhibit cell proliferation, human lung carcinoma cells A549 were seeded into triplicate wells of 96-well plates at a density of 5,000 cells/well and allowed to attach, replaced with serum-free overnight, then the medium was replaced with 2% serum standard DMEM prior to the addition of various concentrations of recombinant human SEMA3F. After incubated for 48h, cells were observed by inverted microscope and cell proliferation was measured by Cell Counting Kit-8 (CCK-8). Briefly, 10µL of CCK-8 solution was added to each well of the plate, then the absorbance at 450nm was measured using a microplate reader after incubating the plate for 1-4 hours at 37℃. Proliferation of A549 cells after incubation with SEMA3F for 48h observed by inverted microscope was shown in Figure 1. Cell viability was assessed by CCK-8 assay after incubation with recombinant SEMA3F for 48h. The result was shown in Figure 2. It was obvious that SEMA3F significantly increased cell viability of A549 cells. (A) A549 cells cultured in DMEM, stimulated with 100ng/mL SEMA3F for 48h; (B) Unstimulated A549 cells cultured in DMEM for 48h.
Figure. Cell proliferation of A549 cells inhibtion by stimulating with SEMA3F.