Photodynamic antitumor activity of aggregation-induced emission luminogens as chemosensitizers for paclitaxel by concurrent induction of apoptosis and autophagic cell death

Despite significant advances in cancer therapy, gastric carcinoma (GC) is still one of the major causes of cancer-associated mortality in the world. Chemotherapy remains the main therapeutic approach for GC patients at advanced stages of disease. The application of photodynamic therapy (PDT) for treating cancers has garnered attention owing to its various advantages. Aggregation-induced emission luminogens (AIEgens) can act as chemo- or photo-sensitizers for cancer therapy. A tetraphenylethene-substituted pyridinium salt (TPE-Py), an AIEgen, exhibited moderate anticancer activity in several cancer cell lines and served as a non-toxic adjuvant to enhance the antitumor effect of paclitaxel (Ptx) in previous studies. However, the anticancer activity and mechanism of TPE-Py remained unclear in GC cell lines. In the current study, TPE-Py could inhibit the growth of gastric cancer cells by inducing apoptotic and autophagic cell death with white light irradiation through regulating apoptosis and autophagy related proteins. Moreover, TPE-Py with white light irradiation could enhance the anticancer activity of Ptx by inducing cellular apoptosis instead of autophagic cell death. These discoveries not only clarify the anticancer activity and mechanism of TPE-Py in GC cell lines, but also provide the possibility of its new clinical application.