Cancer discovery最新文献

KRAS inhibitors demonstrate clinical efficacy in pancreatic ductal adenocarcinoma (PDAC); however, resistance is common. Among patients with KRASG12C-mutant PDAC treated with adagrasib or sotorasib, mutations in PIK3CA and KRAS, and amplifications of KRASG12C, MYC, MET, EGFR, and CDK6 emerged at acquired resistance. In PDAC cell lines and organoid models treated with the KRASG12D inhibitor MRTX1133, epithelial-to-mesenchymal transition and PI3K-AKT-mTOR signaling associate with resistance to therapy. MRTX1133 treatment of the KrasLSL-G12D/+; Trp53LSL-R172H/+; p48-Cre (KPC) mouse model yielded deep tumor regressions, but drug resistance ultimately emerged, accompanied by amplifications of Kras, Yap1, Myc, Cdk6, and Abcb1a/b, and co-evolution of drug-resistant transcriptional programs. Moreover, in KPC and PDX models, mesenchymal and basal-like cell states displayed increased response to KRAS inhibition compared to the classical state. Combination treatment with KRASG12D inhibition and chemotherapy significantly improved tumor control in PDAC mouse models. Collectively, these data elucidate co-evolving resistance mechanisms to KRAS inhibition and support multiple combination therapy strategies. Significance: Acquired resistance may limit the impact of KRAS inhibition in patients with PDAC. Using clinical samples and multiple preclinical models, we define heterogeneous genetic and non-genetic mechanisms of resistance to KRAS inhibition that may guide combination therapy approaches to improve the efficacy and durability of these promising therapies for patients. See related commentary by Marasco and Misale, p. 2018.

In this issue, Gainor and colleagues report on the immunogenicity of personalized neoantigen-encoding mRNA vaccines that elicit measurable polyfunctional CD8+ and CD4+ T-cell responses in patients whose tumors have been resected. Reactivity is substantiated to 20% to 30% of the predicted MHC-I and MHC-II epitopes in four patients with NSCLC postsurgically treated with the vaccine alone and in 12 patients with melanoma treated with their individualized vaccines plus pembrolizumab in the context of a phase 1 clinical trial (NCT03313778). See related article by Gainor et al., p. 2209.

Cellular plasticity is a hallmark of pancreatic ductal adenocarcinoma (PDAC) starting from the conversion of normal cells into precancerous lesions, to the progression of carcinoma subtypes associated with aggressiveness and therapeutic response. We discovered that normal acinar cell differentiation, maintained by the transcription factor PDX1, suppresses a broad gastric cell identity that is maintained in metaplasia, neoplasia, and the classical subtype of PDAC in a mouse and human. We identified the receptor tyrosine kinase ROR2 as marker of a gastric metaplasia-like identity in pancreas neoplasms. Ablation of Ror2 in a mouse model of pancreatic tumorigenesis promoted a switch to a gastric pit cell identity that largely persisted through progression to the classical subtype of PDAC. In both human and mouse pancreatic cancer, ROR2 activity continued to antagonize the gastric pit cell identity, strongly promoting an epithelial to mesenchymal transition, conferring resistance to KRAS inhibition, and vulnerability to AKT inhibition. Significance: We discovered the receptor tyrosine kinase ROR2 as an important regulator of cellular identity in pancreatic precancerous lesions and pancreatic cancer. ROR2 drives an aggressive PDAC phenotype and confers resistance to KRAS inhibitors, suggesting that targeting ROR2 will enhance sensitivity to this new generation of targeted therapies. See related commentary by Marasco and Misale, p. 2018.

Pharmacologically targeting tumor suppressors necessitates an unprecedented strategy of restoring, rather than conventionally inhibiting, protein function, and p53, the most commonly mutated protein in cancer, has thus remained undruggable. In this study, we address long-standing misconceptions in the field and gaps in the scientific logic for a p53 function-restoration strategy, identify four barriers for drugging mutant p53, and accordingly propose effectiveness evaluation criteria, clinical-translating norms, and prospects for mutant p53 rescue compounds.

Chimeric antigen receptor (CAR)-based therapies have pioneered synthetic cellular immunity but remain limited in their long-term efficacy. Emerging data suggest that dysregulated CAR-driven T-cell activation causes T-cell dysfunction and therapeutic failure. To re-engage the precision of the endogenous T-cell response, we designed MHC-independent T-cell receptors (miTCR) by linking antibody variable domains to T-cell receptor constant chains. Using predictive modeling, we observed that this standard "cut and paste" approach to synthetic protein design resulted in myriad biochemical conflicts at the hybrid variable-constant domain interface. Through iterative modeling and sequence modifications, we developed structure-enhanced miTCRs which significantly improved receptor-driven T-cell function across multiple tumor models. We found that 41BB costimulation specifically prolonged miTCR T-cell persistence and enabled improved leukemic control in vivo compared with classic CAR T cells. Collectively, we have identified core features of hybrid receptor structure responsible for regulating function. Significance: Improving the durability of engineered T-cell immunotherapies is critical to enhancing efficacy. We used a structure-informed design to evolve improved miTCR function across several models. This work underscores the central role of synthetic receptor structure in T-cell function and provides a framework for improved receptor engineering.

mRNA-4157 (V940) is an individualized neoantigen therapy targeting up to 34 patient-specific tumor neoantigens to induce T-cell responses and potentiate antitumor activity. We report mechanistic insights into the immunogenicity of mRNA-4157 via characterization of T-cell responses to neoantigens from the first-in-human, phase 1, KEYNOTE-603 study (NCT03313778) in patients with resected non-small cell lung cancer (Part A: 1-mg mRNA-4157, n = 4) or resected cutaneous melanoma (Part D: 1-mg mRNA-4157 + 200-mg pembrolizumab, n = 12). Safety, tolerability, and immunogenicity were assessed. All patients experienced ≥1 treatment-emergent adverse event; there were no grade 4/5 adverse events or dose-limiting toxicities. mRNA-4157 alone induced consistent de novo and strengthened preexisting T-cell responses to targeted neoantigens. Following combination therapy, sustained mRNA-4157-induced neoantigen-specific T-cell responses and expansion of cytotoxic CD8 and CD4 T cells were observed. These findings show the potential of a novel mRNA individualized neoantigen therapy approach in oncology. Significance: The safety and immunogenicity results from this phase 1 study of mRNA-4157 as adjuvant monotherapy or combination therapy with pembrolizumab show generation of de novo and enhancement of existing neoantigen-specific T-cell responses and provide mechanistic proof of concept to support further development of mRNA-4157 for patients with resected solid tumors. See related commentary by Berraondo et al., p. 2021.

Comprehensive N6-methyladenosine (m6A) epitranscriptomic profiling of primary tumors remains largely uncharted. Here, we profiled the m6A epitranscriptome of 10 nonneoplastic lung tissues and 51 lung adenocarcinoma (LUAD) tumors, integrating the corresponding transcriptomic, proteomic, and extensive clinical annotations. We identified distinct clusters and genes that were exclusively linked to disease progression through m6A modifications. In comparison with nonneoplastic lung tissues, we identified 430 transcripts to be hypo-methylated and 222 to be hyper-methylated in tumors. Among these genes, EML4 emerged as a novel metastatic driver, displaying significant hypermethylation in tumors. m6A modification promoted the translation of EML4, leading to its widespread overexpression in primary tumors. Functionally, EML4 modulated cytoskeleton dynamics by interacting with ARPC1A, enhancing lamellipodia formation, cellular motility, local invasion, and metastasis. Clinically, high EML4 protein abundance correlated with features of metastasis. METTL3 small-molecule inhibitor markedly diminished both EML4 m6A and protein abundance and efficiently suppressed lung metastases in vivo. Significance: Our study reveals a dynamic and functional epitranscriptomic landscape in LUAD, offering a valuable resource for further research in the field. We identified EML4 hypermethylation as a key driver of tumor metastasis, highlighting a novel therapeutic strategy of targeting EML4 to prevent LUAD metastasis.

Significant efforts have been made to identify and validate oncoproteins and ncRNAs as therapeutic targets for cancer therapy; however, emerging observations suggest that noncoding cis-regulatory elements, which orchestrate the 3D organization of the genome and thus the transcriptional landscape, are potential therapeutic targets as well. In this commentary, we envisage that further efforts to decipher the noncoding cis-regulatory code and performing systematic surveys of functional noncoding cis-regulatory elements and recurrent 3D genome alterations in both cancerous and nonmalignant cells within tumor tissues will pave the way to the development of novel therapeutic strategies.

Annual low-dose CT screening of individuals with a smoking history identifies early curable lung tumors and reduces cancer mortality by 20%, yet only a minority of eligible patients undergo such monitoring. Mazzone and colleagues apply a blood-based cfDNA fragmentomic assay as a high-sensitivity/low-specificity pre-screen to help stratify individuals who may benefit most from more definitive low-dose CT imaging. See related article by Mazzone et al., p. 2224.

Current strategies for early cancer detection and diagnosis need updating to achieve greater precision, necessitating the creation of a comprehensive evolutionary map of tumorigenesis. This requires establishing high-quality prospective cohorts, systematically collecting samples for integrated spatiotemporal multiomics analyses, and efficiently translating laboratory findings into clinical applications.