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Whether mutations in cancer driver genes directly affect cancer immune phenotype and T cell immunity remains a standing question. ARID1A is a core member of the polymorphic BRG/BRM-associated factor chromatin remodeling complex. ARID1A mutations occur in human cancers and drive cancer development. Here, we studied the molecular, cellular, and clinical impact of ARID1A aberrations on cancer immunity. We demonstrated that ARID1A aberrations resulted in limited chromatin accessibility to IFN-responsive genes, impaired IFN gene expression, anemic T cell tumor infiltration, poor tumor immunity, and shortened host survival in many human cancer histologies and in murine cancer models. Impaired IFN signaling was associated with poor immunotherapy response. Mechanistically, ARID1A interacted with EZH2 via its carboxyl terminal and antagonized EZH2-mediated IFN responsiveness. Thus, the interaction between ARID1A and EZH2 defines cancer IFN responsiveness and immune evasion. Our work indicates that cancer epigenetic driver mutations can shape cancer immune phenotype and immunotherapy., Introduction Tumor-infiltrating T cells are positively associated with patient survival in many types of human cancer (1-3). Type I and type II IFN gene signatures correlate with clinical responses to [...]

Hypoxia-inducible factor (HIF) is strikingly upregulated in many types of cancer, and there is great interest in applying inhibitors of HIF as anticancer therapeutics. The most advanced of these are small molecules that target the HIF-2 isoform through binding the PAS-B domain of HIF-2[alpha]. These molecules are undergoing clinical trials with promising results in renal and other cancers where HIF-2 is considered to be driving growth. Nevertheless, a central question remains as to whether such inhibitors affect physiological responses to hypoxia at relevant doses. Here, we show that pharmacological HIF-2[alpha] inhibition with PT2385, at doses similar to those reported to inhibit tumor growth, rapidly impaired ventilatory responses to hypoxia, abrogating both ventilatory acclimatization and carotid body cell proliferative responses to sustained hypoxia. Mice carrying a HIF-2[alpha] PAS-B S305M mutation that disrupts PT2385 binding, but not dimerization with HIF-1[beta], did not respond to PT2385, indicating that these effects are on-target. Furthermore, the finding of a hypomorphic ventilatory phenotype in untreated HIF-2[alpha] S305M mutant mice suggests a function for the HIF-2[alpha] PAS-B domain beyond heterodimerization with HIF-1[beta]. Although PT2385 was well tolerated, the findings indicate the need for caution in patients who are dependent on hypoxic ventilatory drive., Introduction Hypoxia-inducible factors (HIFs) are transcriptional factors that mediate a wide range of adaptive responses to low oxygen and play a central role in the maintenance of oxygen homeostasis (reviewed [...]

Tumor DNA circulates in the plasma of cancer patients admixed with DNA from noncancerous cells. The genomic landscape of plasma DNA has been characterized in metastatic castration-resistant prostate cancer (mCRPC) but the plasma methylome has not been extensively explored. Here, we performed next-generation sequencing (NGS) on plasma DNA with and without bisulfite treatment from mCRPC patients receiving either abiraterone or enzalutamide in the pre- or post-chemotherapy setting. Principal component analysis on the mCRPC plasma methylome indicated that the main contributor to methylation variance (principal component one, or PC1) was strongly correlated with genomically determined tumor fraction (r = - 0.96; P < [10.sup.8]) and characterized by hypermethylation of targets of the polycomb repressor complex 2 components. Further deconvolution of the PC1 top-correlated segments revealed that these segments are comprised of methylation patterns specific to either prostate cancer or prostate normal epithelium. To extract information specific to an individual's cancer, we then focused on an orthogonal methylation signature, which revealed enrichment for androgen receptor binding sequences and hypomethylation of these segments associated with AR copy number gain. Individuals harboring this methylation pattern had a more aggressive clinical course. Plasma methylome analysis can accurately quantitate tumor fraction and identify distinct biologically relevant mCRPC phenotypes., Introduction Analysis of plasma DNA somatic point mutations or copy number alterations through liquid biopsy has potential utility for informing treatment decisions in cancer patients with a range of tumor [...]

Despite advancements in targeting the immune checkpoints program cell death protein 1 (PD-1), programmed death ligand 1 (PD-L1), and cytotoxic T lymphocyte-associated protein 4 (CTLA-4) for cancer immunotherapy, a large number of patients and cancer types remain unresponsive. Current immunotherapies focus on modulating an antitumor immune response by directly or indirectly expanding antitumor CD8 T cells. A complementary strategy might involve inhibition of Tregs that otherwise suppress antitumor immune responses. Here, we sought to identify functional immune molecules preferentially expressed on tumor-infiltrating Tregs. Using genome-wide RNA-Seq analysis of purified Tregs sorted from multiple human cancer types, we identified a conserved Treg immune checkpoint signature. Using immunocompetent murine tumor models, we found that antibody-mediated depletion of 4-1BB-expressing cells (4-1BB is also known as TNFRSF9 or CD137) decreased tumor growth without negatively affecting CD8 T cell function. Furthermore, we found that the immune checkpoint 4-1BB had a high selectivity for human tumor Tregs and was associated with worse survival outcomes in patients with multiple tumor types. Thus, antibody-mediated depletion of 4-1BB-expressing Tregs represents a strategy with potential activity across cancer types., Introduction Immune checkpoint molecules are a group of surface proteins expressed on various immune cell subsets that can function as either stimulatory or inhibitory mediators, depending upon cell-specific and contextual [...]

Sialyl Lewis A (sLeA, also known as CA19-9), a tetrasaccharide selectively and highly expressed on advanced adenocarcinomas including colon, stomach, and pancreatic cancers, has long been considered as an attractive target for active and passive vaccination. While progress in antibodies targeting tumor-associated protein antigens resulted in an impressive array of therapeutics for cancer treatment, similar progress in exploiting tumor- associated carbohydrate antigens, such as sLeA, has been hampered by the lack of a detailed understanding of the singular characteristics of these antigens. We have addressed this issue by analyzing antibodies derived from patients immunized with an sLeA/KLH vaccine. These antibodies were engineered to mediate tumor clearance in vivo in preclinical models through Fc- Fc[gamma]R interactions. However, in contrast to protein antigens in which hFc[gamma]RIIIA engagement was both necessary and sufficient to mediate tumor clearance in both preclinical and clinical settings, a similar selective dependence was not seen for anti-sLeA antibodies. Thus, re-engineering the Fc portion of sLeA-targeting antibodies to broadly enhance their affinity for activating Fc[gamma]Rs led to an enhanced therapeutic effect. These findings will facilitate the development of more efficient anticancer therapies and further advance this promising class of therapeutic antibodies into clinical use., Introduction Antibody-based therapies are now routinely used in the clinic to treat various malignancies (1). These antibodies target either the tumor directly, activating intrinsic or extrinsic cytotoxic pathways, or target [...]

The development of metastatic melanoma is thought to require the dynamic shifting of neoplastic cells between proliferative and invasive phenotypes. Contrary to this conventional 'phenotype switching' model, we now show that disease progression can involve malignant melanoma cells simultaneously displaying proliferative and invasive properties. Using a genetic mouse model of melanoma in combination with in vitro analyses of melanoma cell lines, we found that conditional deletion of the downstream signaling molecule Smad4, which abrogates all canonical TGF- [beta] signaling, indeed inhibited both tumor growth and metastasis. Conditional deletion of the inhibitory signaling factor Smad7, however, generated cells that are both highly invasive and proliferative, indicating that invasiveness is compatible with a high proliferation rate. In fact, conditional Smad7 deletion led to sustained melanoma growth and at the same time promoted massive metastasis formation, a result consistent with data indicating that low SMAD7 levels in patient tumors are associated with a poor survival. Our findings reveal that modulation of SMAD7 levels can overcome the need for phenotype switching during tumor progression and may thus represent a therapeutic target in metastatic disease., Introduction Despite recent progress in therapy, melanoma has remained by far the deadliest skin cancer, with a 5-year survival rate of only 15% to 20% (1). There is increasing evidence [...]

Intrinsically disordered proteins (IDPs) are emerging as attractive drug targets by virtue of their prevalence in various diseases including cancer. Drug development targeting IDPs is challenging because IDPs have dynamic structure features and conventional drug design is not applicable. NUPR1 is an IDP that plays an important role in pancreatic cancer. We previously reported that trifluoperazine (TFP), an antipsychotic agent, was capable of binding to NUPR1 and inhibiting tumor growth. Unfortunately, TFP showed strong central nervous system side effects. In the present work, we undertook a multidisciplinary approach to optimize TFP based on the synergy of computer modeling, chemical synthesis, and a variety of biophysical, biochemical, and biological evaluations. A family of TFP-derived compounds was produced and the most active one, ZZW115, showed a dose-dependent tumor regression with no neurological effects and an ability to induce cell death mainly by necroptosis. This study opens a new perspective for drug development against IDPs, demonstrating the possibility of successful ligand-based drug design for such challenging targets., Introduction NUPR1 was first described as being activated in the exocrine pancreas in response to the cellular injury induced by pancreatitis (1). Subsequently, the inducible expression of Nuprl was discovered [...]

Byline: Joo. Lim, Kyung. Jung, Mi-Soon. Kim, Jee. You, In-Suh. Park, Soon-Sun. Hong CONTEXT: Glioblastoma is a malignant brain tumor with limited treatment modalities due to its nature. SB365, Pulsatilla [...]