This study aimed to design a novel liposome containing GA modified phosphatidylcholine lipid (GA-PC Lip) and determine its susceptibility to tumor over-expressed secretory phospholipase A2 (sPLA2) and its anti-cancer effect compared to conventional liposomes (Convention Lip). The liposomes were characterized for size, drug loading, encapsulation efficiency, and stability. A 6-CF release assay was conducted to assess the sensitivity of the liposomes to the tumor-overexpressed secretory phospholipase A2 (sPLA2). In vitro experiment, the sPLA2 levels in the Colo205 cell culture medium were detected by the Elisa kit and the anti-cancer effect of the oxaliplatin (L-OHP) loaded GA-PA Lip was analyzed by the CCK-8 assay. Results showed that both of L-OHP loaded formulations (GA-PC Lip and Convention Lip) had similar particle sizes of ∼100 nm and close entrapment efficiency values of 4.5–4.8%. The results of CF release assay indicated that the labeled GA-PC Lip had released more quickly than CF labeled Convention Lip in the presence of Bv sPLA2 and GA-PC Lip had a release of about 95% 6-CF at 2 h, whereas Convention Lip only released about 13% 6-CF. In addition, the average concentrations of sPLA2 in the cell-conditioned medium (CCM) of Colo205 cancer cells increased with incubation time and L-OHP loaded GA-PC Lip had much greater anti-proliferative activity than Convention Lip against Colo205 cells. These findings suggest that GA-PC Lip is an ideal complex for sPLA2-triggered release and has potential applications in enzyme-triggered smart anti-cancer drug release system to increase the anti-cancer effect.
Previous studies have indicated the potential role of estrogen in the development and prognosis of colorectal cancer (CRC). Nonylpheno (NP) is an endocrine‑disrupting chemical, which may influence the development of estrogen‑dependent types of cancer. However, the molecular mechanism of NP in the development of CRCs remains unclear. In the present study, various concentrations of NP were used to treat COLO205 CRC cells, and the expression of protein kinase C ζ (PKCζ) was knocked down using PKCζ small interfering RNA. The effects of NP in various concentrations on the cell cycle and apoptosis of COLO205 cells were examined, and the change in the expression level of PKCζ was analyzed. The results indicated that NP may significantly induce proliferation of COLO205 CRC cells, and significantly reduce cell apoptosis. However, suppression of PKCζ expression may inhibit proliferation, while NP could reduce this inhibition. The results of a western blot analysis indicated that the expression level of cyclin D1 and E were significantly increased following NP treatment, and the expression of p27 was significantly decreased. The phosphorylation of PKCζ and extracellular‑signal‑regulated kinase (ERK)1/2 was significantly increased following NP treatment in a dose‑dependent manner. Overall, NP induced human CRC COLO205 cell proliferation and inhibited the apoptotic rate of COLO205 cells by increasing the activity of PKCζ and ERK1/2.
Background Oridonin has been demonstrated to have anticancer effect on all kinds of cancer cells and it has shown anti-tumor activity in some tumors partially via the inactivation of Wnt/β-catenin signaling pathway. The study investigated the anticancer effect of oridonin on colon carcinoma cell line COLO205 and explored underlying mechanism. Methods Cell Counting Kit-8 (CCK-8) assay was performed to assess cell viability. Flow cytometry was performed to analyze the apoptosis. The key target genes and proteins involved in Wnt/β-catenin pathway were detected by quantitative polymerase chain reaction (qPCR) and Western blotting. The xenograft tumor model of colon cancer COLO205 cell was introduced to detect anti-tumor effects in vivo . Transferase-mediated dUTP nick end labeling (TUNEL) assay was adopted to test the apoptotic cells in the tumor tissues. Results Oridonin inhibited the proliferation of colon cancer COLO205 cells in a dose-dependent and time-dependent manner. Oridonin induced apoptosis by increasing the cleavage of caspases in vitro . Furthermore, the expression levels of β-catenin and its downstream targets, including c-myc, cyclinD1 and survivin were significantly reduced. Nevertheless the knockdown of β-catenin by specific small interfering RNA (siRNA) could augment the anti-proliferative and pro-apoptotic effects by oridonin in COLO205 cells. Meanwhile, oridonin also increased protein expression level of glycogen synthase kinase 3β (GSK3β) and decreased the phosphorylation level of GSK3β. In vivo , oridonin treatment significantly suppressed tumor growth of COLO205 cell xenografts, and which was accompanied by the restrain of Wnt/β-catenin pathway. Conclusions Our present study demonstrated that the growth inhibition and apoptosis induction in colon cancer COLO205 cells by oridonin could be partially mediated through discontinuing Wnt/β-catenin signaling pathway.
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