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Biology subjects

Adler, K. M.

Publications and source records attributed to Adler, K. M..

4 recordsLinked to original sources

The H3K36M oncohistone inhibits NSD2 to activate a SETD2-dependent antiviral-like immune response in KRAS-driven lung cancer

Mutations in histone 3 at or near lysine 36 (H3K36) have dominantly acting oncogenic effects in multiple tumor types by limiting H3K36-directed methyltransferases. Paradoxically, we find that expression of the H3K36M oncohistone unexpectedly inhibits tumor formation in KRAS-driven lung adenocarcinoma by inducing a potent immune-mediated tumor clearance. Mechanistically, oncohistone expression derepresses endogenous retroviral element transcription, results in the accumulation of double-stranded RNA (dsRNA), and activates an innate antiviral-like immune response that eradicates tumor growth. Surprisingly, while inactivation of the H3K36 di-methyltransferase NSD2 replicated all effects of oncohistone expression, inactivation of the H3K36 tri-methyltransferase SETD2 abolished element derepression and all associated downstream anti-cancer effects that are induced by oncohistone expression. These observations restructure our understanding of the roles of H3K36 methylation, the consequences of its deregulation in cancer, and shape our expectations for therapeutic interventions targeting H3K36 methyltransferases.

cancer biology↗

Tumor suppressor genotype influences the extent and mode of immunosurveillance in lung cancer

The impact of cancer driving mutations in regulating immunosurveillance throughout tumor development remains poorly understood. To better understand the contribution of tumor genotype to immunosurveillance, we generated and validated lentiviral vectors that create an epi-allelic series of increasingly immunogenic neoantigens. This vector system is compatible with autochthonous Cre-regulated cancer models, CRISPR/Cas9-mediated somatic genome editing, and tumor barcoding. Here, we show that in the context of KRAS-driven lung cancer and strong neoantigen expression, tumor suppressor genotype dictates the degree of immune cell recruitment, positive selection of tumors with neoantigen silencing, and tumor outgrowth. By quantifying the impact of 11 commonly inactivated tumor suppressor genes on tumor growth across neoantigenic contexts, we show that the growth promoting effects of tumor suppressor gene inactivation correlate with increasing sensitivity to immunosurveillance. Importantly, specific genotypes dramatically increase or decrease sensitivity to immunosurveillance independently of their growth promoting effects. We propose a model of immunoediting in which tumor suppressor gene inactivation works in tandem with neoantigen expression to shape tumor immunosurveillance and immunoediting such that the same neoantigens uniquely modulate tumor immunoediting depending on the genetic context. One Sentence SummaryHere we uncover an under-appreciated role for tumor suppressor gene inactivation in shaping immunoediting upon neoantigen expression.

cancer biology↗

Setd2 inactivation sensitizes lung adenocarcinoma to inhibitors of oxidative respiration and mTORC1 signaling

SETD2 is a tumor suppressor that is frequently inactivated in several cancer types. The mechanisms through which SETD2 inactivation promotes cancer are unclear, and whether targetable vulnerabilities exist in these tumors is unknown. Here we identify heightened mTORC1-associated gene expression programs and functionally higher levels of oxidative metabolism and protein synthesis as prominent consequences of Setd2 inactivation in KRAS-driven mouse models of lung adenocarcinoma. Blocking oxidative respiration and mTORC1 signaling abrogates the high rates of tumor cell proliferation and tumor growth specifically in SETD2-deficient tumors. Our data nominate SETD2 deficiency as a functional marker of sensitivity to clinically actionable therapeutics targeting oxidative respiration and mTORC1 signaling.

cancer biology↗

p53 restoration in small cell lung cancer identifies a latent Cyclophilin-dependent necrosis mechanism

The p53 tumor suppressor regulates multiple context-dependent tumor suppressive programs. Although p53 is mutated in [~]90% of small cell lung cancer (SCLC) tumors, how p53 mediates tumor suppression in this context is unknown. Here, using a mouse model of SCLC in which endogenous p53 expression can be conditionally and temporally regulated, we show that SCLC tumors maintain a requirement for p53 inactivation. However, we identified tumor subtype heterogeneity between SCLC tumors such that p53 reactivation induces a canonical senescence response in a subset of tumors, while, in others, p53 induces a non-apoptotic form of cell death that culminates in necrosis. We pinpointed the cyclophilin family of peptidyl prolyl cis-trans isomerases as critical determinants of a p53-induced transcriptional program that is specific to SCLC tumors and cell lines that are poised to undergo p53-mediated necrosis. Importantly, inhibition of cyclophilin isomerase activity suppresses SCLC subtype-specific p53-mediated death by limiting p53 transcriptional output without impacting chromatin binding. Our study demonstrates that intertumoral heterogeneity in SCLC can influence the biological response to p53 restoration, describes a novel mechanism of p53-regulated necrotic cell death, and uncovers new targets for the treatment of this most-recalcitrant tumor type.

cancer biology↗