Immunotherapy, particularly immune checkpoint inhibitors (ICIs) programmed death-ligand 1/programmed death-1 (PD-L1/PD-1) and cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), has heralded a new era of tumor treatment. Although ICIs have clinical benefits, their complex heterogeneity and diverse resistance mechanisms critically limit their efficacy. Neoantigens, arising from tumor-specific alterations, offer novel targets for individualized immunotherapy, because of their high immunogenicity and tumor specificity. In the past decade, neoantigen-based tumor vaccines have been demonstrated to be a promising immunotherapy strategy to prime the tumor-specific immune response. These therapeutic vaccines include peptide vaccines, nucleic acid vaccines, and dendritic cell (DC) vaccines, and are categorized according to the neoantigen source and delivery method. In vivo, neoantigens are processed and presented by antigen-presenting cells (APCs) via the peptide-Major Histocompatibility Complex (pMHC) for T cell recognition, thereby triggering specific immune responses. Because DCs, the most potent APCs, play crucial roles in antitumor immunity, neoantigen-based DC vaccines provide a promising therapeutic strategy. A series of global clinical trials are exploring the safety, feasibility, and efficacy of neoantigen-based DC vaccines in tumors. This review focuses on current progress in clinical research on neoantigen-based DC vaccines in the treatment of solid tumors.

A significant number of anticancer drugs fail to treat primary and metastatic brain tumors primarily because of the complex blood-brain barrier (BBB) and overexpression of ATP-binding cassette (ABC) transporters, which decrease drug penetration into the central nervous system and ultimately into tumors. It is noteworthy that the ABC transporters, ABCB1 [known as P-glycoprotein (P-gp)] and ABCG2 [known as breast cancer resistance protein (BCRP)], are overexpressed in brain tumors, including common gliomas. The co-presence of these transporters may negate the inhibition of either transporter, particularly if both transport the same anticancer drug. The cellular export of drugs by ABC transporters has been implicated in mediating resistance to anticancer drugs. However, the clinical relevance as a therapeutic target in human tumors remains a matter of contention. Although effective and clinically approved ABC transporter inhibitors could potentially overcome drug resistance, none are currently approved. Furthermore, the ABC transporter inhibitors in clinical trials produced low or no clinical efficacy, significant toxicities, and unsuitable pharmacokinetic profiles. Therefore, innovative approaches are needed to efficaciously and simultaneously inhibit these transporters to surmount anticancer drug resistance. This review emphasizes the clinical significance of ABC transporters in diminishing the efficacy of brain tumor treatments. The molecular alterations in BBB following brain tumor development, which are linked to various cancer therapies, are discussed. The overexpression of ABCB1 and ABCG2 at the BBB is discussed, potential strategies to decrease the export of chemotherapeutics by these transporters and the associated challenges and failures are discussed, and the implementation of novel approaches is considered.

The occurrence and progression of liver cancer are closely associated with mitochondrial dysfunction. Mitochondria exhibit characteristics, such as decreased oxidative phosphorylation efficiency, abnormal accumulation of reactive oxygen species in liver cancer and promoting tumor proliferation and drug resistance through the Warburg effect, as the core of energy metabolism and apoptosis regulation. Mutations in mitochondrial DNA (mtDNA) and dysregulation of mitochondrial autophagy (mitophagy) further enhance the invasive and metastatic capabilities of liver cancer. Current targeted therapeutic strategies focus on modulating the activity of respiratory chain complexes, regulating calcium homeostasis, repairing mtDNA, and activating mitochondrial apoptotic pathways. Although these approaches have shown therapeutic effects, challenges persist, such as tumor heterogeneity, insufficient drug specificity, and drug resistance. Future research needs to integrate the concept of precision medicine by focusing on breakthroughs in the molecular mechanisms underlying mitochondrial dysfunction, development of targeted delivery systems, optimization of combination therapy regimens, and screening of biomarkers to provide new pathways for individualized treatment. With advances in technology, targeting mitochondrial dysfunction is expected to become an important breakthrough for improving the prognosis of liver cancer.