Antitumor effects of concanavalin A and Sophora flavescens lectin in vitro and in vivo

Abstract

Aim: Proteins with legume lectin domains are known to possess a wide range of biological functions. Here, the antitumor effects of two representative legume lectins, concanavalin A (ConA) and Sophora flavescens lectin (SFL), on human breast carcinoma cells were investigated in vitro and in vivo. Methods: Human breast carcinoma MCF-7 cells and human normal mammary epithelial MCF-10A cells were examined. Cell viability was detected using WST-1 and CCK-8 assays. Cell apoptosis was analyzed with Hoechst 33258 staining. Cell cycle was investigated using flow cytometry. The expression of relevant proteins was measured using Western blotting. Breast carcinoma MCF-7 bearing nude mice were used to study the antitumor effects in vivo. The mice were injected with ConA (40 mg/kg, ip) and SFL (55 mg/kg, ip) daily for 14 d. Results: ConA and SFL inhibited the growth of MCF-7 cells in dose-and time-dependent manners (IC 50 values were 15 and 20 μg/mL, respectively). Both ConA and SFL induced apoptotic morphology in MCF-7 cells without affecting MCF-10A cells. ConA and SFL dosedependently increased the sub-G 1 proportion in MCF-7 cells, while SFL also triggered the G 2 /M phase cell cycle arrest. Both ConA and SFL dose-dependently increased the activities of caspase-3 and caspase-9 and release of cytochrome c from mitochondria into cytoplasm, up-regulated Bax and Bid, and down-regulated Bcl-2 and Bcl-X L in MCF-7 cells. ConA reduced NF-κB, ERK, and JNK levels, and increased p53 and p21 levels, while SFL caused similar changes in NF-κB, ERK, p53, and p21 levels, but did not affect JNK expression. Administration of ConA and SFL significantly decreased the subcutaneous tumor mass volume and weight in MCF-7 bearing nude mice. Conclusion: ConA and SFL exert anti-tumor actions against human breast carcinoma MCF-7 cells both in vitro and in vivo.

Antiviral and antitumor activities of the lectin extracted from Aspidistra elatior

“…The lectin was found to be inactive against the HeLa or p53-deficient Hep3B cell lines at all concentrations and for the entire duration studies (Figure 2). This finding is consistent with the earlier reported variation in the anti-proliferative potential of a variety of lectins with tumor cell lines as a function of their doses [19,21,22].…”

“…Antibodies against p21, p53, and actin B were purchased from Santa Cruz Biotech (Santa Cruz, CA, USA). Proteins were visualized using horseradish peroxidase (HRP)-conjugated anti-rabbit or anti-mouse IgG and 3,3-diaminobenzidine tetrahydrochloride (DAB) as the HRP substrate [22].…”

“…Western blot data demonstrated that treatment of Bre-04, Lu-04, HepG2, and Pro-01 cells with AEL resulted in upregulation of p53 Figure 3). Considering that p53 is an important regulator of p21 [22], p21 levels were also assessed. As seen in Figure 2, p21 was increased in parallel to p53.…”

Conformational study reveals amino acid residues essential for hemagglutinating and anti-proliferative activities of <italic>Clematis montana</italic> lectin

“…Plant lectin has become researchers' focus because of its anti-tumor activity to diverse types of cancer cells [25,26]. Notably, several plant lectins have been shown to induce apoptotic cancer cell death [27,28], but the mechanism is still not clear.…”

A Novel Molecular Model of Plant Lectin-Induced Programmed Cell Death in Cancer

“…As for the PCL of GNA family, PCL-Fas binding would initiate caspasedependent apoptosis, similarly the PCL-epidermal growth factor receptor (EGFR) binding inhibits both apoptotic and autophagic cell death. 28) …”