Berberine alkaloids inhibit the proliferation and metastasis of breast carcinoma cells involving Wnt/ß-catenin signaling and EMT.

Berberine alkaloids belong to the class of isoquinoline alkaloids that have been shown to possess anticancer potential, berberine exhibits inhibitory effects on breast cancer development. However, the exact mechanisms of action for anti-breast carcinoma of the alkaloids, including epiberberine, berberrubine and dihydroberberine are still unclear. MTT assay, colony formation, wound healing and transwell invasion assays detected these alkaloids suppressed proliferation, migration and invasion of breast cancer cells. Hoechst and Annexin V-FITC/PI staining were used to analyze the apoptosis of breast cancer cells. Western blotting investigated the changes noted in the expression levels of the key proteins involved in the Wnt/ß-catenin signaling pathway and epithelial to mesenchymal transition (EMT). The results showed that inhibited the proliferation of breast cancer cells. Berberine alkaloids inhibited the cell cycle at G2/M phase in MCF-7 cells, but in MDA-MB-231 cells berberine alkaloids arrested the cell cycle in G0/G1 and G2/M phases. By decreasing ß-catenin expression, increasing GSK-3ß expression and decreasing N-cadherin expression, increasing E-cadherin expression, which proved that epiberberine, berberrubine and dihydroberberine inhibited of metastasis of breast cancer cells through Wnt signaling pathway and reversed EMT except berberine. Furthermore, berberine alkaloids exert their anti-breast cancer effects through the synergistic action of intrinsic and extrinsic pathways of apoptosis. These findings highlight the different effects of different berberine alkaloids on breast cancer cells and confirm that berberine alkaloids may be potentially used in the treatment of breast cancer.

Nanocomplex of Berberine with C60 Fullerene Is a Potent Suppressor of Lewis Lung Carcinoma Cells Invasion In Vitro and Metastatic Activity In Vivo.

Effective targeting of metastasis is considered the main problem in cancer therapy. The development of herbal alkaloid Berberine (Ber)-based anticancer drugs is limited due to Ber' low effective concentration, poor membrane permeability, and short plasma half-life. To overcome these limitations, we used Ber noncovalently bound to C60 fullerene (C60). The complexation between C60 and Ber molecules was evidenced with computer simulation. The aim of the present study was to estimate the effect of the free Ber and C60-Ber nanocomplex in a low Ber equivalent concentration on Lewis lung carcinoma cells (LLC) invasion potential, expression of epithelial-to-mesenchymal transition (EMT) markers in vitro, and the ability of cancer cells to form distant lung metastases in vivo in a mice model of LLC. It was shown that in contrast to free Ber its nanocomplex with C60 demonstrated significantly higher efficiency to suppress invasion potential, to downregulate the level of EMT-inducing transcription factors SNAI1, ZEB1, and TWIST1, to unblock expression of epithelial marker E-cadherin, and to repress cancer stem cells-like markers. More importantly, a relatively low dose of C60-Ber nanocomplex was able to suppress lung metastasis in vivo. These findings indicated that сomplexation of natural alkaloid Ber with C60 can be used as an additional therapeutic strategy against aggressive lung cancer.

Toxicity of C60 fullerene-cisplatin nanocomplex against Lewis lung carcinoma cells.

Cisplatin (Cis-Pt) is the cytotoxic agent widely used against tumors of various origin, but its therapeutic efficiency is substantially limited by a non-selective effect and high toxicity. Conjugation of Cis-Pt with nanocarriers is thought to be one option to enable drug targeting. The aim of this study was to estimate toxic effects of the nanocomplex formed by noncovalent interaction of C60 fullerene with Cis-Pt against Lewis lung carcinoma (LLC) cells in comparison with free drug. Scanning tunneling microscopy showed that the minimum size of C60-Cis-Pt nanoparticles in aqueous colloid solution was 1.1 nm whereas that of C60 fullerene was 0.72 nm, thus confirming formation of the nanocomplex. The cytotoxic effect of C60-Cis-Pt nanocomplex against LLC cells was shown to be higher with IC50 values 3.3 and 4.5 times lower at 48 h and 72 h, respectively, as compared to the free drug. 12.5 µM Cis-Pt had no effect on LLC cell viability and morphology while C60-Cis-Pt nanocomplex in Cis-Pt-equivalent concentration substantially decreased the cell viability, impaired their shape and adhesion, inhibited migration and induced accumulation in proapoptotic subG1 phase. Apoptosis induced by the C60-Cis-Pt nanocomplex was confirmed by caspase 3/7 activation and externalization of phosphatidylserine on the outer surface of LLC cells with the double Annexin V-FITC/PI staining. We assume that C60 fullerene as a component of the C60-Cis-Pt nanocomplex promoted Cis-Pt entry and intracellular accumulation thus contributing to intensification of the drug's toxic effect against lung cancer cells.