Abnormal expression of APRIL in colorectal cancer cells promotes tumor growth and metastasis / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the effects of a proliferation-inducing ligand (APRlL) on colorectal cancer (CRC) cell growth and migration, and to observe the role of APRIL in CRC biological behavior.</p><p><b>METHODS</b>The siRNA plasmid vector targeting APRIL gene (APRIL-siRNA) was transfected into human colorectal cancer SW480 cells and recombinant human APRIL (rhAPRIL) was used to stimulate human colorectal cancer HCT-116 cells. Cell proliferation activity was analyzed using cell counting kit-8 (CCK-8), cell cycle was detected by flow cytometry, and the protein expression of cyclin D1, p21 and Bcl-2 was detected by Western blot analysis. Tumor cell migration and invasion were measured by Transwell chambers. RT-PCR was applied to examine the mRNA expression level of MMP-2 and MMP-9. APRIL-siRNA was used to transfect directly SW480 cells, which were injected subcutaneously into nude mice, then the tumor growth and metastasis were observed.</p><p><b>RESULTS</b>Cell proliferation ability of APRIL-siRNA-transfected SW480 cells was drastically repressed, and the percentage of G0/G1 phase cells was significantly increased (t = 4.12, P < 0.05), accompanied with depressed cyclin D1, Bcl-2 expression and elevated p21 expression. Cell proliferation ability of rhAPRIL-stimulated HCT-116 cells was promoted with a decreased G0/G1 phase ratio (t = 3.31, P < 0.05). cyclin D1 and Bcl-2 protein expression was up-regulated while p21 was down-regulated by rhAPRIL stimulation. Metastatic and invasive capacities of APRIL-siRNA-transfected SW480 cells were significantly inhibited compared with their respective controls (both P < 0.05), accompanied with the deregulated MMP-2 and MMP-9 mRNA expression. Metastatic and invasive capacities of rhAPRIL-stimulated HCT-116 cells were promoted with up-regulated MMP-2 and MMP-9 mRNA expression(both P < 0.05). Tumor growth in the group transfected with APRIL-siRNA appeared to be slower than that in the control groups and the expression of MMP-2, MMP-9 in tumor tissues was depressed in the APRIL-siRNA group.</p><p><b>CONCLUSIONS</b>APRIL facilitates tumor growth and metastasis, and is associated with carcinogenesis and prognosis. Our findings suggest that APRIL might be used as a novel target for the intervention and therapy of colorectal cancer.</p>

Effect of APRIL on growth and apoptosis in transplanted tumor with human colorectal cancer cell line SW480 in nude mice / 中华肿瘤杂志

<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>