Antibody-dependent cellular phagocytosis of tropomyosin receptor kinase C (TrkC) expressing cancer cells for targeted immunotherapy

Synergistic approach of PEGylated photothermal agent and immunomodulator in cancer immunotherapy

Photothermal therapy (PTT) utilizes photothermal agents (PTAs) to generate heat at the local tumor site that leads to ablation upon photoirradiation at a specific wavelength of light. Currently, most of the available PTAs have weak tumor selectivity and depositing ability, which leads to poor therapeutic outcomes. PEGylation of PTAs improves therapeutic outcomes, prolongs systemic circulation time, enhances tumor accumulation, and reduces the risk of clearance by the immune system. This paper reviews the recent developments of PEGylated PTAs in photothermal cancer therapy from 2019 to 2023, highlighting their antitumour efficacy and immune response post-therapy with immune agents, current challenges and strategies. This review aims to foster knowledge dissemination on the application of nanomedicine in photothermal cancer therapy from an immunological perspective and to encourage the clinical translation of these nanomaterials.

Identification and structural analysis of a selective tropomyosin receptor kinase C (TRKC) inhibitor

Tropomyosin receptor kinases (TRKs) are a family of TRKA, TRKB and TRKC isoforms. It has been widely reported that TRKs are implicated in a variety of tumors with several Pan-TRK inhibitors currently being used or evaluated in clinical treatment. However, off-target adverse events frequently occur in the clinical use of Pan-TRK inhibitors, which result in poor patient compliance, even drug discontinuation. Although a subtype-selectivity TRK inhibitor may avert the potential off-target adverse events and can act as a more powerful tool compound in the biochemical studies on TRKs, the high sequence similarities of TRKs hinder the development of subtype-selectivity TRK inhibitors. For example, no selective TRKC inhibitor has been reported. Herein, a selective TRKC inhibitor (L13) was disclosed, with potent TRKC inhibitory activity and 107.5-/34.9-fold selectivity over TRKA/B (IC₅₀ TRKA/B/C = 1400 nM, 454 nM, 13 nM, respectively). Extensive molecular dynamics simulations illustrated that key interactions of L13 with the residues and diversely conserved water molecules in the ribose regions of different TRKs may be the structural basis of selectivity. This will provide inspiring insights into the development of subtype-selectivity TRK inhibitors. Moreover, L13 could serve as a tool compound to investigate the distinct biological functions of TRKC and a starting point for further research on drugs specifically targeting TRKC.