Interference of Skp2 effectively inhibits the development and metastasis of colon carcinoma

Abstract

Abstract. Colon cancer is a common type of malignancy in the digestive system. The aim of the present study was to investigate the role of S-phase kinase-associated protein 2 (Skp2) in colon carcinoma and to identify whether depletion of Skp2 by Skp2-RNA interference (RNAi) attenuates the proliferation and migration of colon carcinoma. Three pairs of small interfering (si)RNA were designed based on the Skp2 gene sequence and the most effective one was used to silence the Skp2 gene in SW620 cells. Subsequent to the interference, quantitative polymerase chain reaction and western blot analysis were used for detecting the expression of Skp-2 mRNA and protein, respectively. The data demonstrated that the Skp2-siRNA effectively inhibited proliferation (P<0.01), increased the levels of apoptosis and induced G 0 /G 1 phase arrest of the SW620 cells (P<0.01). Transfection of the Skp2 siRNA into SW620 cells effectively reduced Skp2 protein levels, while p27 protein levels increased. In the in vivo experiments, a lentiviral vector of the Skp2-RNAi transfected into SW620 cells markedly inhibited Skp2 expression, as detected by immunohistochemical analysis of nude mice. Additionally, tumorigenicity experiments showed that inhibition of Skp2 significantly increased the survival rate of nude mice. Thus, the in vitro and in vivo results demonstrated that interference of Skp2 expression significantly inhibited the proliferation and induced the apoptosis of SW620 cells. This suggests that Skp2 protein has an important role in the progression of colon cancer. Therefore, Skp2 may enable the early diagnosis of colon cancer and provide new insights into molecular targets for cancer therapy.

Two Transcripts of FBXO5 Promote Migration and Osteogenic Differentiation of Human Periodontal Ligament Mesenchymal Stem Cells

“…Previous report found that downregulation of Skp2 inhibits the viability, proliferation, colony formation, migration, and invasion and induces apoptosis of human gastric cancer cells. Chen et al also found that Skp2-RNAi inhibits the migratory ability of SW620 cells [ 40 ]. The influences of Skp2 on cell migration and invasion are mainly mediated through its downstream factors, p27 and p21, by different mechanisms [ 41 , 42 ].…”

Knockdown of AMPKα2 Promotes Pulmonary Arterial Smooth Muscle Cells Proliferation via mTOR/Skp2/p27Kip1 Signaling Pathway

“…Moreover, tumors overexpressing Skp2 are strongly associated with low p27 Kip1 levels and poor disease-free and overall survival [ 44 ]. Inhibition of Skp2 prevents p27 Kip1 degradation and suppresses proliferation of many cell types [ 45 , 46 ]. p27 Kip1 as a CDK inhibitor binds to and prevents the activation of cyclin E-CDK2 and cyclin D-CDK4 complexes, therefore blocks the G1-S transition of cell cycle and suppresses cell proliferation [ 47 , 48 ].…”

Functional significance and therapeutic implication of ring-type E3 ligases in colorectal cancer

“…Overexpression of SKP2 promotes cell proliferation in normal colon cells, whereas knockdown of SKP2 inhibited cell proliferation and induced the apoptosis of SW620 colon cancer cells. 111 , 112 SKP2, as an F-box protein, recognizes cyclin-dependent kinase (CDK) inhibitors p27 kip1 and p21 and mediates their ubiquitin-mediated proteasomal degradation. 113 Degradation of p21 and p27 by SKP2 activates CDK1 and CDK2 and promotes S and G2 cell cycle phase progression, thereby positively regulating the cell cycle 114 ( Figure 3 ).…”