Feasibility and safety of modified en-bloc resection in endoscopic thyroid surgery via bilateral areolar approach - long-term institutional analysis ten years after surgery.

Purpose: This study aimed to introduce a new modified en-bloc resection method and evaluate its feasibility and safety in endoscopic thyroid surgery via bilateral areolar approach (BAA). Methods: Papillary thyroid carcinoma (PTC) patients who underwent lobectomy and ipsilateral central node dissection (CND) via the BAA approach were retrospectively reviewed. Their clinical characteristics and outcomes were evaluated, including operative duration, lymph node yield (LNY), surgical complications, recurrence rate, and metastasis rate, over a ten-year follow-up period. Simultaneous lobectomy and CND were performed in the modified en-bloc group, whereas lobectomy was performed first, followed by CND in the conventional group. Results: The study included 108 patients in the modified en-bloc group and 213 in the conventional group. There were no significant differences in gender, age, tumor locations, tumor dominant nodule size, or the incidence of concomitant Hashimoto thyroiditis when comparing clinicopathologic characteristics. The comparison of operative duration (P = 0.14), blood loss (P = 0.13), postoperative hospital stay (P = 0.58), incidence of transient vocal cord paralysis (P = 0.90) and hypocalcemia (P = 0.60) did not show any differences. The mean LNY achieved in the central compartment of the modified en-bloc group (7.5 ± 4.5) was significantly higher than that in the conventional group (5.6 ± 3.6). Two patients in the modified en-bloc group and two in the conventional group experienced metastasis after surgery during the ten-year follow-up (1.8% vs. 0.9%, P = 0.60). The learning curve analysis showed a significant decrease in operative duration after the 25-35th cases for modified en-bloc resection. Conclusions: The modified en-bloc resection method in endoscopic thyroid surgery via BAA is a technically feasible and safe procedure with excellent cosmetic outcomes for selective PTC patients.

Inhibition of CD38 enzymatic activity enhances CAR-T cell immune-therapeutic efficacy by repressing glycolytic metabolism.

Chimeric antigen receptor (CAR)-T therapy has shown superior efficacy against hematopoietic malignancies. However, many patients failed to achieve sustainable tumor control partially due to CAR-T cell exhaustion and limited persistence. In this study, by performing single-cell multi-omics data analysis on patient-derived CAR-T cells, we identify CD38 as a potential hallmark of exhausted CAR-T cells, which is positively correlated with exhaustion-related transcription factors and further confirmed with in vitro exhaustion models. Moreover, inhibiting CD38 activity reverses tonic signaling- or tumor antigen-induced exhaustion independent of single-chain variable fragment design or costimulatory domain, resulting in improved CAR-T cell cytotoxicity and antitumor response. Mechanistically, CD38 inhibition synergizes the downregulation of CD38-cADPR -Ca2+ signaling and activation of the CD38-NAD+-SIRT1 axis to suppress glycolysis. Collectively, our findings shed light on the role of CD38 in CAR-T cell exhaustion and suggest potential clinical applications of CD38 inhibition in enhancing the efficacy and persistence of CAR-T cell therapy.

Mitochondrial isocitrate dehydrogenase impedes CAR T cell function by restraining antioxidant metabolism and histone acetylation.

The efficacy of chimeric antigen receptor (CAR) T cell therapy is hampered by relapse in hematologic malignancies and by hyporesponsiveness in solid tumors. Long-lived memory CAR T cells are critical for improving tumor clearance and long-term protection. However, during rapid ex vivo expansion or in vivo tumor eradication, metabolic shifts and inhibitory signals lead to terminal differentiation and exhaustion of CAR T cells. Through a mitochondria-related compound screening, we find that the FDA-approved isocitrate dehydrogenase 2 (IDH2) inhibitor enasidenib enhances memory CAR T cell formation and sustains anti-leukemic cytotoxicity in vivo. Mechanistically, IDH2 impedes metabolic fitness of CAR T cells by restraining glucose utilization via the pentose phosphate pathway, which alleviates oxidative stress, particularly in nutrient-restricted conditions. In addition, IDH2 limits cytosolic acetyl-CoA levels to prevent histone acetylation that promotes memory cell formation. In combination with pharmacological IDH2 inhibition, CAR T cell therapy is demonstrated to have superior efficacy in a pre-clinical model.