Abstract
Selenium has remained a controversial character in cancer research. While its antitumor effects have been widely demonstrated, further evidence is required to establish it as a robust treatment regime. Sodium selenite (SS), an inorganic selenium, reportedly affected the proliferation and redifferentiation of gastric cancer cells, but whether it could act as a complement to conventional chemotherapeutic drugs for combination therapy is uncertain. Herein, SGC-7901 and MGC-803 gastric cancer cells were treated with PADM (Ac-Phe-Lys-PABC-ADM), a prodrug of doxorubicin/adriamycin (ADM), and the combined antitumor effects of the two drugs were evaluated. Characterization after treatment revealed that although PADM exhibited antitumor effects individually by inhibiting the proliferation and migration of gastric cancer cells and inducing apoptosis, the addition of SS significantly amplified these effects. Furthermore, gastric cancer cell apoptosis triggered by the combined treatment of SS and PADM may involve the participation of mitochondrial apoptosis, as evidenced by the changes in mitochondrial morphology and occurrence of mitochondrial fission. Collectively, SS could be a strong complementary drug that accentuates the therapeutic potential of PADM in gastric cancer treatment and management, and its significance could contribute to unique and innovative anticancer strategies.