Protosappanin B Exerts Anti-tumor Effects on Colon Cancer Cells via Inhibiting GOLPH3 Expression.

Protosappanin B (PSB) is a key active component of Lignum Sappan extract. Although the antiproliferative effects of Lignum Sappan extract have been demonstrated in various cancer cells, relatively little is known about the effects of PSB on tumor progression. The aim of this study was to explore the anti-tumor effects of PSB on human colon cancer cells by regulation of intracellular signaling pathways and Golgi phosphoprotein 3 (GOLPH3) expression in vitro and in vivo. Our results showed that PSB effectively inhibited the viability and migration of SW620 cells and induced apoptosis, but had poor effect on HCT116 cells. Furthermore, PSB significantly reduced the expression of p-AKT, p-p70S6K, ß-catenin, and p-ERK1/2 proteins in SW620 cells, and this effect was reversed by the corresponding signaling pathway agonists. Interestingly, PSB could also suppress GOLPH3 expression of SW620 cells in a concentration-dependent manner, but SW620 cells transfected with lentiviral vectors overexpressing GOLPH3 can effectively resist the cytotoxic activity of PSB in vitro. The xenograft experiment of SW620 cells with LV-GOLPH3 confirmed that PSB distinctly inhibited the tumor growth via suppressing GOLPH3 expression. Collectively, these findings clarified a new anti-cancer mechanism of PSB through inhibition of GOLPH3 expression and intracellular signaling pathways in colon cancer cells. PSB may be a potential new drug for colon cancer.

Tenacissoside H Induces Apoptosis and Inhibits Migration of Colon Cancer Cells by Downregulating Expression of GOLPH3 Gene.

OBJECTIVE: Tenacissoside H (TDH) is a Chinese medicine monomer extracted from Marsdenia tenacissima extract (MTE), which has been confirmed to have antitumor effects, but its mechanism is still unclear. The aim of this study was to investigate the effect and mechanism of TDH on human colon cancer LoVo cell proliferation and migration and explore the correlation of TDH treatment with the expression of GOLPH3 and cell signaling pathways in LoVo cells. METHODS: LoVo cells were treated with TDH at 0.1, 1, 10, and 100 µg/mL for 24, 48, and 72 h. The proliferation rate of LoVo cells was evaluated by MTT assay. Recombinant plasmid p-CMV-2-GOLPH3 was constructed, and p-CMV-2-GOLPH3 and p-CMV-2 empty plasmids were transfected into LoVo cells by lipofection. Western blotting was used to detect the transfection efficiency and the expression of p-p70S6K, p70S6K, ß-catenin, and GOLPH3. The apoptosis rate was analyzed with Annexin V-FITC/PI double-staining method, and cell migration assessed by transwell assay. RESULTS: TDH inhibited the proliferation of LoVo cells in a concentration-dependent manner. The IC50 of TDH treatment in LoVo cells at 24, 48, and 72 h was 40.24, 13.00, and 5.73 µg/mL, respectively. TDH treatment significantly induced apoptosis and suppressed the viability and migration of human colon cancer LoVo cells. The effect of TDH on induction of apoptosis and inhibition of migration in LoVo cells decreased significantly after activating the PI3K/AKT/mTOR and Wnt/ß-catenin signaling pathways with agonists. Additionally, the expression of GOLPH3 protein downregulated significantly in LoVo cells under TDH treatment. Overexpression of the GOLPH3 gene increased the expression of key proteins in PI3K/AKT/mTOR and Wnt/ß-catenin signaling pathways and blocked the antitumor activity of TDH. CONCLUSION: Collectively, the present results indicated that TDH can inhibit the proliferation vitality of colon cancer LoVo cells through downregulating GOLPH3 expression and activity of PI3K/AKT/mTOR and Wnt/ß-catenin signaling pathways.