Photodynamic therapy (PDT) is a low invasive antitumor therapy with fewer side effects. On the other hand, immunotherapy also has significant clinical applications in the treatment of cancer. Both therapies, on their own, have some limitations and are incapable of meeting the demands of the current cancer treatment. The efficacy of PDT and immunotherapy against tumor metastasis and tumor recurrence may be improved by combination strategies. In this review, we discussed the possibility that PDT could be used to activate immune responses by inducing immunogenic cell death or generating cancer vaccines. Furthermore, we explored the latest advances in PDT antitumor therapy in combination with some immunotherapy such as immune adjuvants, inhibitors of immune suppression, and immune checkpoint blockade.

Background Esophageal carcinoma (EC) is one of the most deadly malignant tumors in the world. Surgery, combined with chemotherapy or radiotherapy, is the traditional strategy for the treatment of EC. Cisplatin (CDDP) is a common chemotherapy drug widely used to treat EC due to its powerful anti-tumor effect. However, CDDP is subject to intrinsic or acquired resistance in EC cells, which badly hinders the efficacy of chemotherapy. The resistance phenomenon is mostly caused by the p53 mutant in the EC and the low efficiency of the drug delivery system. Methods In this study, a specially designed nanomicelle was used to promote the anti-tumor effect of chemotherapy drugs against the CDDP-resistant EC cells. The nanomicelle consisted of miR-34a, doxorubicin (DOX), polyethylene glycol (PEG), and other excipients in an appropriate ratio. Results The results showed that the nanomicelle could exert significant cell proliferation inhibition and apoptosis-inducing effects in the CDDP-resistant EC cells. The endogenous expression of miR-34a in the CDDP-resistant EC cells was promoted by the incubation with the nanomicelle. After incubation with the nanomicelle, the expression of protein SIRT1 was inhibited, and the expression of caspase3 was promoted significantly in the CDDP-resistant EC cells. Conclusions Our results indicate that the specially designed nanomicelle can exert promising anti-tumor effects by introducing miR-34a to inhibit SIRT1 signaling pathway and enhance the efficiency of the drug delivery system.