ABSTRACT
<p><b>OBJECTIVE</b>To study the effect of pGCsi-H1-APRIL on the growth of human colorectal cancer cells in transplated tumor in nude mice and to improve the effect of APRIL on proliferation and apoptosis of colorectal cancer (CRC).</p><p><b>METHODS</b>Human CRC model was established in nude mice, and the nude mice were treated with APRIL siRNA twice per week for 2 weeks. APRIL mRNA expression was surveyed by PCR and APRIL protein expression was detected by immunohistochemistry. The expression of PCNA protein was detected by ELISA. The expression of bcl-2 and bcl-xl was assessed by immunohistochemical staining, and TUNEL staining was used to detect apoptosis.</p><p><b>RESULTS</b>The expression of APRIL mRNA in the APRIL siRNA group was (0.13 ± 0.05) × 10(-3), significantly lower than that in the vector group (0.95 ± 0.04) × 10(-3) and the PBS group (0.96 ± 0.05) × 10(-3). The expression of APRIL protein in the APRIL siRNA group was (87.5 ± 5.0)% lower than that in the vector and PBS groups (P < 0.05). APRIL siRNA significantly suppressed the growth of SW480 tumor: the IR (inhibitory rate) of APRIL siRNA group was (60.7 ± 1.5)% (P < 0.05). The expression of PCNA in APRIL siRNA group was (176.8 ± 18.1) ng/ml, was (56.5 ± 2.0)% lower than that of PBS group (328.4 ± 22.8) ng/ml. Furthermore, the expressions of anti-apoptosis proteins bcl-2 and bcl-xl of APRIL siRNA group were (82.6 ± 4.5)% and (79.2 ± 3.5)% lower than those of the PBS group. The apoptotic rate of the APRIL siRNA group was 40.1% ± 2.5%, significantly higher than that in the vector group (2.5 ± 0.1)% and PBS group (2.5 ± 0.2)% (P < 0.05).</p><p><b>CONCLUSION</b>APRIL siRNA may significantly suppress the growth and promote apoptosis in transplanted tumor of human colorectal cancer in nude mice. APRIL may become a candidate gene of gene therapy of human colorectal cancer.</p>