Background & objective: A proliferation-inducing ligand (APRIL), a new member of the tumor necrosis factor (TNF) family, can stimulate tumor cell growth and proliferation both in vitro and in vivo. This research was to detect the expression of APRIL in colorectal carcinoma tissues, and to compare the effects of 5-fluorouracil (5-FU) and cisplatin (DDP) on the expression of APRIL in colorectal carcinoma SW480 cells.
Methods: The protein and mRNA levels of APRIL in 56 specimens of human colorectal carcinoma and para-tumor tissues and in SW480 cells were determined by immunohistochemistry and real-time fluorescence quantitative reverse transcription-polymerase chain reaction (FQ-RT-PCR). SW480 cells were treated with 5-FU and DDP at various concentrations for 24 h, 48 h and 72 h. The changes of APRIL mRNA level were analyzed by FQ-RT-PCR.
Results: Both positive rate and mRNA level of APRIL were significantly higher in colorectal carcinoma tissues than in para-tumor tissues (76.8% vs. 16.1%, 0.16+/-0.05 vs. 0.71+/-0.08, both P<0.001). The expression of APRIL was strong in SW480 cells. When treated with different concentrations of 5-FU, the mRNA level of APRIL in SW480 cells raised gradually and reached the highest levels at 72 h after treatment (0.85+/-0.10, 0.81+/-0.09, 0.83+/-0.11, and 0.90+/-0.12 at the concentrations of 25, 50, 100 and 200 microg/mL, respectively), which were significantly higher than those in blank control group (P<0.001). When treated with different concentrations of DDP, the mRNA level of APRIL in SW480 cells did not increase when compared with that in control group (P>0.05). After 72-hour treatment, the mRNA level of APRIL in SW480 cells was significantly lower in 10 microg/mL and 20 microg/mL DDP groups than in blank control group (0.44+/-0.05 and 0.40+/-0.07 vs. 0.57+/-0.06, P<0.05).
Conclusions: APRIL may promote the development of colorectal carcinoma. When chemotherapy is conducted to treat colorectal carcinoma, especially when 5-FU is included in the regimen, anti-APRIL therapy might be an important assistant treatment to counter the impact of APRIL caused by antitumor drugs.