Enhanced Antitumor Activity of Korean Black Soybean Cultivar ‘Soman’ by Targeting STAT-Mediated Aerobic Glycolysis

Black soybeans have numerous health benefits owing to their high polyphenolic content, antioxidant activity, and antitumor effects. We previously reported that the Korean black soybean cultivar 'Soman' possesses higher anthocyanin and isoflavone contents and superior antioxidant potential than other Korean black soybean cultivars and landraces (Seoritae) do. Here, we investigated and compared the antitumor effects of Soman and Seoritae and aimed to elucidate the possible mechanisms of action. Soman inhibited cancer cell proliferation and was more potent than Seoritae. Mechanistically, Soman inhibited the phosphorylation of the signal transducer and activator of transcription (STAT1, 3, and 5) in a reactive oxygen species (ROS)-independent manner, subsequently decreasing glycolytic enzyme expression and the activities of pyruvate kinase and lactate dehydrogenase. Thus, Soman suppressed glucose uptake, lactate production, and ATP production in cancer cells. Additionally, it inhibited tumor growth in a B16F10 murine melanoma syngeneic model, accompanied by reduced STAT1 phosphorylation and decreased proliferation in Soman-treated mice, more potently than observed in Seoritae-treated mice. These findings showed that Soman exerted superior antitumor activities by suppressing STAT-mediated aerobic glycolysis and proliferation. Overall, our findings demonstrate the potent, tumor-suppressive role of Soman in human cancer and uncover a novel molecular mechanism for its therapeutic effects in cancer treatment.