Cancer discovery最新文献

Significance: Clinically available KRAS* inhibitors and IO agents alleviated the immunosuppressive tumor microenvironment in PDAC. Profound tumor regression and prolonged survival in an autochthonous PDAC model provide a compelling rationale for combining KRAS* inhibition with IO agents targeting multiple arms of the immunity cycle to combat PDAC.

Understanding tumor heterogeneity is a major challenge that was recognized as one of the first Cancer Grand Challenges, with a call to provide solutions to visualize tumor heterogeneity. The Rosetta team took on this challenge, exploiting advances in spatial-omics approaches centered around mass spectrometry imaging to map tumor heterogeneity at the cellular and molecular scales with different levels of resolution. See related article by Bressan et al., p. 16 See related article by Stratton et al., p. 22 See related article by Bhattacharjee et al., p. 28.

Small cell lung cancer (SCLC) and pulmonary carcinoid tumors are traditionally seen as unrelated, with SCLC linked to smoking and characterized by biallelic loss of RB1 and TP53 and rapid progression. Rekhtman and colleagues upend these assumptions by discovering an "atypical" SCLC that arises in nonsmokers with intact RB1 and TP53 loci, chromothripsis-induced oncogene amplifications on extrachromosomal DNA, and frequent synchronous carcinoid tumors. See related article by Rekhtman et al., p. 83.

Small cell lung carcinoma (SCLC) is a highly aggressive malignancy that is typically associated with tobacco exposure and inactivation of RB1 and TP53 genes. Here, we performed detailed clinicopathologic, genomic, and transcriptomic profiling of an atypical subset of SCLC that lacked RB1 and TP53 co-inactivation and arose in never/light smokers. We found that most cases were associated with chromothripsis-massive, localized chromosome shattering-recurrently involving chromosome 11 or 12 and resulting in extrachromosomal amplification of CCND1 or co-amplification of CCND2/CDK4/MDM2, respectively. Uniquely, these clinically aggressive tumors exhibited genomic and pathologic links to pulmonary carcinoids, suggesting a previously uncharacterized mode of SCLC pathogenesis via transformation from lower-grade neuroendocrine tumors or their progenitors. Conversely, SCLC in never-smokers harboring inactivated RB1 and TP53 exhibited hallmarks of adenocarcinoma-to-SCLC derivation, supporting two distinct pathways of plasticity-mediated pathogenesis of SCLC in never-smokers. Significance: Here, we provide the first detailed description of a unique SCLC subset lacking RB1/TP53 alterations and identify extensive chromothripsis and pathogenetic links to pulmonary carcinoids as its hallmark features. This work defines atypical SCLC as a novel entity among lung cancers, highlighting its exceptional histogenesis, clinicopathologic characteristics, and therapeutic vulnerabilities. See related commentary by Nadeem and Drapkin, p. 8.

Immunotherapies against brain metastases have shown clinical benefits when applied to asymptomatic patients, but they are largely ineffective in symptomatic cases for unknown reasons. Here, we dissect the heterogeneity in metastasis-associated astrocytes using single-cell RNA sequencing and report a population that blocks the antitumoral activity of infiltrating T cells. This protumoral activity is mediated by the secretion of tissue inhibitor of metalloproteinase-1 (TIMP1) from a cluster of pSTAT3+ astrocytes that acts on CD63+ CD8+ T cells to modulate their function. Using genetic and pharmacologic approaches in mouse and human brain metastasis models, we demonstrate that combining immune checkpoint blockade antibodies with the inhibition of astrocyte-mediated local immunosuppression may benefit patients with symptomatic brain metastases. We further reveal that the presence of tissue inhibitor of metalloproteinase-1 in liquid biopsies provides a biomarker to select patients for this combined immunotherapy. Overall, our findings demonstrate an unexpected immunomodulatory role for astrocytes in brain metastases with clinical implications. Significance: This study presents a significant advancement in understanding immune modulation in brain tumors and offers new insights into the potential therapeutic interventions for brain metastases. See related commentary by Lorger and James, p. 11.