Immune checkpoint blockade therapy has revolutionized cancer treatment, but resistance remains prevalent, often due to dysfunctional tumor-infiltrating lymphocytes. A key contributor to this dysfunction is mitochondrial dysfunction, characterized by defective oxidative phosphorylation, impaired adaptation, and depolarization, which promotes T cell exhaustion and severely compromises antitumor efficacy. This review summarizes recent advances in restoring the function of exhausted T cells through mitochondria-targeted strategies, such as metabolic remodeling, enhanced biogenesis, and regulation of antioxidant and reactive oxygen species, with the aim of reversing the state of T cell exhaustion and improving the response to immunotherapy. A deeper understanding of the role of mitochondria in T cell exhaustion lays the foundation for the development of novel mitochondria-targeted therapies and opens a new chapter in cancer immunotherapy.

Purpose: The role of neoadjuvant epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) targeted therapy for patients with EGFR-mutant non-small cell lung cancer (NSCLC) has not been clarified. A pooled analysis of prospective clinical trials was conducted to evaluate the efficacy and safety of neoadjuvant EGFR-TKI therapy. Methods: The PubMed, Embase, Web of Science, and Cochrane Library databases, as well as meeting abstracts were searched for prospective clinical trials evaluating the efficacy and safety of neoadjuvant EGFR-TKI for treatment of EGFR-mutant NSCLC. The main outcomes included the objective response rate (ORR), downstaging rate, surgical resection rate (SRR), pathologic complete response (pCR) rate, progression-free survival (PFS), and adverse events. Results: A total of five, phase II, prospective, clinical trials involving 124 patients with resectable or potentially resectable EGFR-mutant NSCLC treated with neoadjuvant erlotinib or gefitinib treatment were included in this pooled analysis. The median neoadjuvant medication time was 42 (range, 21–56) days and the median time of response evaluation was 45 (range, 42–56) days. The pooled ORR was 58.5% [95% confidence interval (CI), 45.5%–71.8%] and the surgical resection and complete resection (R0) rates were 79.9% (95% CI, 65.3%–94.5%) and 64.3% (95% CI, 43.8%–84.8%), respectively. In the stage IIIA subgroup (n = 68), the pooled ORR, SRR, and R0 rate were 51.4%, 72.9%, and 57.0%, respectively, while the downstaging and pCR rates were 14.0% and 0.0%, respectively. The pooled median PFS and overall survival were 13.2 and 41.9 months, respectively. Of the most common grade 3/4 adverse events in the overall group, the incidences of hepatotoxicity and skin rash were 5.3% and 14.7%, respectively. The most commonly reported postoperative complications were lung infection, arrhythmia, and pneumothorax. Conclusion: Neoadjuvant EGFR-TKI therapy provides a feasible treatment modality for patients with resectable or potentially resectable EGFR-mutant NSCLC, with satisfactory surgical outcomes and low toxicity. Although further phase III clinical trials are needed to confirm these findings, it is necessary to explore the feasibility of a more effective EGFR-TKI combination neoadjuvant therapy given the modest downgrade and pCR rates for EGFR-TKI alone.

In recent years, various breakthroughs have been made in tumor immunotherapy that have contributed to prolonging the survival of tumor patients. However, only a subset of patients respond to immunotherapy, which limits its use. One reason for this is that the tumor microenvironment (TME) hinders the migration and infiltration of T cells and affects their continuous functioning, resulting in an exhausted phenotype. Therefore, clarifying the mechanism by which T cells become exhausted is of significance for improving the efficacy of immunotherapy. Several recent studies have shown that mitochondrial dynamics play an important role in the immune surveillance function of T cells. Dynamin-related protein 1 (Drp1) is a key protein that mediates mitochondrial fission and maintains the mitochondrial dynamic network. Drp1 regulates various activities of T cells in vivo by mediating the activation of a series of pathways. In addition, abnormal mitochondrial dynamics were observed in exhausted T cells in the TME. As a potential target for immunotherapy, in this review, we describe in detail how Drp1 regulates various physiological functions of T cells and induces changes in mitochondrial dynamics in the TME, providing a theoretical basis for further research.

Background: In the era of immunotherapy, it is still unclear which is the best first-line therapy for patients with oncogenic driver negative advanced non-squamous non-small cell lung cancer (NS-NSCLC) who cannot tolerate immunotherapy, or subsequent therapy for patients with oncogenic driver positive NS-NSCLC whose disease progressed on prior targeted therapy. To assess the optimal choice of first-line and maintenance treatment regimens, we performed a meta-analysis of prospective randomized controlled clinical trials (RCTs) of patients with NS-NSCLC on bevacizumab combined with chemotherapy. Methods: All eligible RCTs comparing pemetrexed-platinum with or without bevacizumab (PP ± B) and paclitaxel-carboplatin with bevacizumab (PC + B) as a first-line therapy, or comparing bevacizumab plus pemetrexed (Pem + B) and bevacizumab alone (B) as a maintenance treatment for advanced NS-NSCLC, were included after systematically searching web databases and meeting abstracts. The main research endpoints were comparisons of overall survival (OS) and progression-free survival (PFS). The other endpoints were objective response rate (ORR), 1-year PFS rate (PFSR1y) and major grade 3/4 treatment-related adverse events. Results: Data of 3139 patients from six RCTs were incorporated into analyses. Three RCTs were included in an analysis that compared PP ± B and PC + B as a first-line therapy for advanced NS-NSCLC. Patients treated with first-line PP ± B showed similar OS and ORR, but significantly improved PFS (hazard ratio [HR], 0.88) and PFSR1y (risk ratio [RR], 0.83), as compared to patients treated with PC + B (all P < 0.05). PP ± B resulted in higher rates of grade 3/4 anemia and thrombocytopenia, but lower rates of neutropenia, febrile neutropenia, and sensory neuropathy than PC + B (all P < 0.001). The other three RCTs were included in an analysis that compared Pem + B and B as a maintenance treatment. Compared with B, Pem + B maintenance treatment resulted in significant improvements in OS (HR, 0.88), PFS (HR, 0.64), and PFSR1y (RR, 0.70), but higher rates of anemia, thrombocytopenia, and neutropenia (all P < 0.001). Conclusion: Although the first-line PP + B regimen had longer PFS and PFSR1y than the PC + B regimen, no OS difference was observed. Addition of pemetrexed to bevacizumab as maintenance therapy significantly improved OS compared with bevacizumab maintenance alone, but led to more toxicity.