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Biomedical subjects

Natalie I Vokes

Publications and source records attributed to Natalie I Vokes.

3 recordsLinked to original sources

Distinct endogenous retroviruses are expressed in mutational subtypes of clear cell renal cell carcinoma and are linked to improved clinical outcomes.

Distinct mutations in chromatin regulators and aberrant expression of transposable elements (TEs), have been associated with clinical benefit to immunotherapy (IO) in specific clear cell renal cell carcinoma (ccRCC) clinical contexts. However, the relationship between mutations in chromatin regulators and TE expression, and their effect on clinical outcomes, are incompletely understood. Here, we identified TEs expressed in distinct mutational subtypes of ccRCC, with endogenous retroviruses (ERVs) comprising the majority of TEs observed. Of these, ERVs 544 and 2014 were upregulated in PBRM1 mutant samples. Patients with high expression of these ERVs and somatic PBRM1 mutations had improved progression-free survival with IO monotherapy, but not targeted therapy, and their upregulation associated with expression of innate immune pathways. Chromatin accessibility increased at ERV 544 and 2014 loci in PBRM1-deficient ccRCC cells, and ERV 544 and 2014 were upregulated upon in vitro PBRM1 knockout in ccRCC cell line clones. Broadly, our study supports a link between PBRM1 mutations, subsequent chromatin accessibility changes, and aberrant but immunoresponsive ERVs in ccRCC.

CP: cancer

Distinct Clinicogenomic Features and Immunotherapy Associations in Pulmonary Sarcomatoid Carcinoma: A Multicenter Retrospective Study.

INTRODUCTION: Pulmonary sarcomatoid carcinoma (PSC) is a rare NSCLC subtype with poor prognosis. Outcomes to immune checkpoint inhibitors (ICIs) and genomic features in PSC remain underexplored compared with other NSCLC subtypes. METHODS: Patients from three institutions and the National Cancer Database (NCDB) with metastatic NSCLC treated with ICI alone or with chemotherapy were identified. Clinicogenomics and treatment outcomes were compared across PSC, lung adenocarcinoma (LUAD), and lung squamous cell carcinoma (LUSC). RESULTS: We analyzed 4841 patients including 165 PSC cases treated with ICI-based therapy from three institutions and 201 PSC from NCDB. In MDACC, 65 (4.3%) were PSC, 1138 (75.1%) LUAD, and 312 (20.6%) LUSC. Patients with PSC were older and more likely to present with metastatic disease. In both the MDACC and NCDB cohorts, ICIs resulted in better outcomes for patients with PSC compared with chemotherapy. In these patients, there was no difference in outcome between ICI-monotherapy and ICI-chemotherapy. Across the three institutional cohorts, 37% to 43% of patients with PSC who received ICIs were responders, compared with 26% to 29% in LUAD and 22% to 46% in LUSC (p < 0.05). Improved ICI outcomes in PSC appeared driven by high PD-L1 (&#x2265;50% in 73%-77% cases). Among patients with high PD-L1, response rates were similar across histologic subtypes. Conversely, TMB was similar in PSC compared with LUAD or LUSC and was not associated with ICI outcomes. Across cohorts, PSC tumors were enriched for TP53, NF1, NF2, and NRAS, with relative depletion of STK11 and KEAP1 compared with LUAD. Case observation revealed relatively better outcomes to ICI than targeted therapies in patients with PSC with MET exon 14 skipping or KRAS G12C. CONCLUSION: PSC exhibits improved outcomes to ICI relative to other therapies, potentially driven by high PD-L1 expression. Genomic analysis highlights a distinct genomic landscape of PSC when compared with LUAD.

Humans

MCT4-dependent lactate secretion suppresses antitumor immunity in LKB1-deficient lung adenocarcinoma.

Inactivating STK11/LKB1 mutations are genomic drivers of primary resistance to immunotherapy in KRAS-mutated lung adenocarcinoma (LUAD), although the underlying mechanisms remain unelucidated. We find that LKB1 loss results in enhanced lactate production and secretion via the MCT4 transporter. Single-cell RNA profiling of murine models indicates that LKB1-deficient tumors have increased M2 macrophage polarization and hypofunctional T&#xa0;cells, effects that could be recapitulated by the addition of exogenous lactate and abrogated by MCT4 knockdown or therapeutic blockade of the lactate receptor GPR81 expressed on immune cells. Furthermore, MCT4 knockout reverses the resistance to PD-1 blockade induced by LKB1 loss in syngeneic murine models. Finally, tumors from STK11/LKB1 mutant LUAD patients demonstrate a similar phenotype of enhanced M2-macrophages polarization and hypofunctional T&#xa0;cells. These data provide evidence that lactate suppresses antitumor immunity and therapeutic targeting of this pathway is a promising strategy to reversing immunotherapy resistance in STK11/LKB1 mutant LUAD.

Animals