Fanfan Fan

Mast cells constitute indispensable immunoregulatory sentinel cells in the tumor microenvironment. A better understanding of the regulation and functions of mast cells in lung adenocarcinoma (LUAD) could uncover therapeutic approaches to reprogram the immunosuppressive tumor microenvironment. Here, we performed flow cytometry and single-cell RNA sequencing (scRNA-seq) of patient LUAD samples to comprehensively characterize LUAD-infiltrating mast cells. Mast cells exhibited functional heterogeneity and were enriched in LUAD with ground-glass opacity features (gLUAD). The mast cells in gLUAD exhibited proinflammatory and chemotactic properties while those in radiologically solid LUAD (sLUAD) were associated with tumor angiogenesis. Mast cells were an important source of CCL2 and correlated with the recruitment of CCR2+ CTL, a specific subcluster of preexhausted T cells with tissue-resident memory phenotype and enhanced cytotoxicity. Increased infiltration of mast cells and CCR2+ CTLs and their colocalization showed a strong association with favorable prognosis after surgery but were not associated with improved survival after chemotherapy. Collectively, these findings reveal a key role of mast cells in LUAD and their potential cross-talk with CTLs, suggesting that targeting mast cells may be an immunotherapeutic strategy for LUAD. SIGNIFICANCE: Comprehensive characterization of mast cells in lung adenocarcinoma elucidates their heterogeneity and identifies interplay between mast cells and CCR2+ T cells that is associated with a favorable prognosis.

In this work, the solubilities of (R)- and (R,S)-crizotinib in six solvents including methanol, ethanol, 1-propanol, 1-butanol, ethyl acetate, and n-hexane were first measured by a static method in the temperature range from 273.15 to 323.15 K at atmospheric pressure. Then, molecular simulations were performed to predict the crystal structures of (R)-crizotinib and (R,S)-crizotinib from their powder X-ray diffractograms and the solubilities in the above organic solvents using the Gibbs free energy calculation approach via the sublimation cycle. The results showed that the solubilities of (R)- and (R,S)-crizotinib in the selected solvents generally increased with the increasing temperature, and at room temperature the molar fraction solubility order was methanol > 1-butanol > 1-propanol > ethanol > ethyl acetate > n-hexane. The (R)-crizotinib crystal had a monoclinic unit cell, while the (R,S)-crizotinib crystal had a triclinic one. In particular, though it was first applied to the solubility estimation for water-insoluble drug compounds in organic solvents, the Gibbs energy calculation approach developed gave a desirable solubility prediction performance with a root-mean-square error (RMSE) of 0.7638 log S units for (R)-crizotinib and 1.1577 log S units for (R,S)-crizotinib in the selected solvents, respectively. Furthermore, the difference in the solubilities of (R)-crizotinib in different solvents mainly resulted from the different Gibbs free energies for solvation between solute and solvent other than those for sublimation. However, as to the difference in the solubilities of (R)- and (R,S)-crizotinib in the same solvent, the Gibbs free energy for sublimation made more of a contribution than that for solvation. Finally, on the basis of the solid-state characterization, the nature of crystalline (R,S)-crizotinib was confirmed to be a racemic compound. All these results shall provide pharmaceutical industry with a better understanding of this chiral system for crystallization resolution.