Targeting P4HA1 promotes CD8 T cell progenitor expansion toward immune memory and systemic anti-tumor immunity.

Successful immunotherapy relies on both intratumoral and systemic immunity, which is yet to be achieved for most patients with cancer. Here, we identify P4HA1, encoding prolyl 4-hydroxylase 1, as a crucial regulator of CD8 T cell differentiation strongly upregulated in tumor-draining lymph nodes (TDLNs) and hypoxic tumor microenvironment. P4HA1 accumulates in mitochondria, disrupting the tricarboxylic acid (TCA) cycle through aberrant α-ketoglutarate and succinate metabolism, promoting mitochondria unfitness and exhaustion while suppressing progenitor expansion.

IFI16-dependent STING signaling is a crucial regulator of anti-HER2 immune response in HER2+ breast cancer.

Relapse to anti-HER2 monoclonal antibody (mAb) therapies, such as trastuzumab in HER2 breast cancer (BC), is associated with residual disease progression due to resistance to therapy. Here, we identify interferon-γ inducible protein 16 (IFI16)-dependent STING signaling as a significant determinant of trastuzumab responses in HER2 BC. We show that down-regulation of immune-regulated genes (IRG) is specifically associated with poor survival of HER2, but not other BC subtypes.

Hypoxia induces HIF1α-dependent epigenetic vulnerability in triple negative breast cancer to confer immune effector dysfunction and resistance to anti-PD-1 immunotherapy.

The hypoxic tumor microenvironment has been implicated in immune escape, but the underlying mechanism remains elusive. Using an in vitro culture system modeling human T cell dysfunction and exhaustion in triple-negative breast cancer (TNBC), we find that hypoxia suppresses immune effector gene expression, including in T and NK cells, resulting in immune effector cell dysfunction and resistance to immunotherapy. We demonstrate that hypoxia-induced factor 1α (HIF1α) interaction with HDAC1 and concurrent PRC2 dependency causes chromatin remolding resulting in epigenetic suppression of effector genes and subsequent immune dysfunction.

Stromal induction of BRD4 phosphorylation Results in Chromatin Remodeling and BET inhibitor Resistance in Colorectal Cancer.

BRD4, a Bromodomain and Extraterminal (BET) protein family member, is a promising anti-cancer drug target. However, resistance to BET inhibitors targeting BRD4 is common in solid tumors. Here, we show that cancer-associated fibroblast (CAF)-activated stromal signaling, interleukin-6/8-JAK2, induces BRD4 phosphorylation at tyrosine 97/98 in colorectal cancer, resulting in BRD4 stabilization due to interaction with the deubiquitinase UCHL3.

EZH2-mediated PP2A inactivation confers resistance to HER2-targeted breast cancer therapy.

HER2-targeted therapy has yielded a significant clinical benefit in patients with HER2+ breast cancer, yet disease relapse due to intrinsic or acquired resistance remains a significant challenge in the clinic. Here, we show that the protein phosphatase 2A (PP2A) regulatory subunit PPP2R2B is a crucial determinant of anti-HER2 response. PPP2R2B is downregulated in a substantial subset of HER2+ breast cancers, which correlates with poor clinical outcome and resistance to HER2-targeted therapies.

KDM4B-regulated unfolded protein response as a therapeutic vulnerability in -deficient breast cancer.

deficiency in breast cancer leads to resistance to PI3K-AKT inhibitor treatment despite aberrant activation of this signaling pathway. Here, we report that genetic depletion or small molecule inhibition of KDM4B histone demethylase activates the unfolded protein response (UPR) pathway and results in preferential apoptosis in -deficient triple-negative breast cancers (TNBCs). Intriguingly, this function of KDM4B on UPR requires its demethylase activity but is independent of its canonical role in histone modification, and acts through its cytoplasmic interaction with eIF2α, a crucial component of UPR signaling, resulting in reduced phosphorylation of this component.

KDM6B Counteracts EZH2-Mediated Suppression of to Confer Resistance to PI3K/AKT Inhibitor Treatment in Breast Cancer.

Despite showing promise against -mutant breast cancers in preclinical studies, PI3K/AKT pathway inhibitors demonstrate limited clinical efficacy as monotherapy. Here, we found that histone H3K27me3 demethylase KDM6B-targeted expression provides a protective mechanism for PI3K/AKT inhibitor-induced apoptosis in breast cancer cells. We found that overexpression of and in luminal breast cancer are positively associated with poorer disease outcomes.

Hypoxic tumor microenvironment activates GLI2 via HIF-1α and TGF-β2 to promote chemoresistance in colorectal cancer.

Colorectal cancer patients often relapse after chemotherapy, owing to the survival of stem or progenitor cells referred to as cancer stem cells (CSCs). Although tumor stromal factors are known to contribute to chemoresistance, it remains not fully understood how CSCs in the hypoxic tumor microenvironment escape the chemotherapy. Here, we report that hypoxia-inducible factor (HIF-1α) and cancer-associated fibroblasts (CAFs)-secreted TGF-β2 converge to activate the expression of hedgehog transcription factor GLI2 in CSCs, resulting in increased stemness/dedifferentiation and intrinsic resistance to chemotherapy.

Chromosome 1q21.3 amplification is a trackable biomarker and actionable target for breast cancer recurrence.

Tumor recurrence remains the main reason for breast cancer-associated mortality, and there are unmet clinical demands for the discovery of new biomarkers and development of treatment solutions to benefit patients with breast cancer at high risk of recurrence. Here we report the identification of chromosomal copy-number amplification at 1q21.3 that is enriched in subpopulations of breast cancer cells bearing characteristics of tumor-initiating cells (TICs) and that strongly associates with breast cancer recurrence.

HIFI-α activation underlies a functional switch in the paradoxical role of Ezh2/PRC2 in breast cancer.

Despite the established oncogenic function of Polycomb repressive complex 2 (PRC2) in human cancers, its role as a tumor suppressor is also evident; however, the mechanism underlying the regulation of the paradoxical functions of PRC2 in tumorigenesis is poorly understood. Here we show that hypoxia-inducible factor 1, α-subunit (HIFI-α) is a crucial modulator of PRC2 and enhancer of zeste 2 (EZH2) function in breast cancer. Interrogating the genomic expression of breast cancer indicates high HIF1A activity correlated with high EZH2 expression but low PRC2 activity in triple-negative breast cancer compared with other cancer subtypes.

IRAK1 is a therapeutic target that drives breast cancer metastasis and resistance to paclitaxel.

Metastatic tumour recurrence due to failed treatments remains a major challenge of breast cancer clinical management. Here we report that interleukin-1 receptor-associated kinase 1 (IRAK1) is overexpressed in a subset of breast cancers, in particular triple-negative breast cancer (TNBC), where it acts to drive aggressive growth, metastasis and acquired resistance to paclitaxel treatment. We show that IRAK1 overexpression confers TNBC growth advantage through NF-κB-related cytokine secretion and metastatic TNBC cells exhibit gain of IRAK1 dependency, resulting in high susceptibility to genetic and pharmacologic inhibition of IRAK1.

Functional Characterization of D9, a Novel Deazaneplanocin A (DZNep) Analog, in Targeting Acute Myeloid Leukemia (AML).

Aberrant epigenetic events contribute to tumorigenesis of all human cancers. Significant efforts are underway in developing new generation of epigenetic cancer therapeutics. Although clinical trials for agents targeting DNA hypermethylation and histone deacetylation have yielded promising results, developing agents that target histone methylation remains to be in the early stage.

3-Deazaneplanocin A and neplanocin A analogues and their effects on apoptotic cell death.

3-Deazaneplanocin A (DzNep) is a potential epigenetic drug for the treatment of various cancers. DzNep has been reported to deplete histone methylations, including oncogenic EZH2 complex, giving rise to epigenetic modifications that reactivate many silenced tumor suppressors in cancer cells. Despite its promise as an anticancer drug, little is known about the structure-activity relationships of DzNep in the context of epigenetic modifications and apoptosis induction.

EZH2-mediated inactivation of IFN-γ-JAK-STAT1 signaling is an effective therapeutic target in MYC-driven prostate cancer.

Although small-molecule targeting of EZH2 appears to be effective in lymphomas carrying EZH2 activating mutations, finding similar approaches to target EZH2-overexpressing epithelial tumors remains challenging. In MYC-driven, but not PI3K-driven prostate cancer, we show that interferon-γ receptor 1 (IFNGR1) is directly repressed by EZH2 in a MYC-dependent manner and is downregulated in a subset of metastatic prostate cancers. EZH2 knockdown restored the expression of IFNGR1 and, when combined with IFN-γ treatment, led to strong activation of IFN-JAK-STAT1 tumor-suppressor signaling and robust apoptosis.

PDK1 signaling toward PLK1-MYC activation confers oncogenic transformation, tumor-initiating cell activation, and resistance to mTOR-targeted therapy.

Unlabelled: Although 3-phosphoinositide-dependent protein kinase-1 (PDK1) has been predominately linked to the phosphoinositide 3-kinase (PI3K)-AKT pathway, it may also evoke additional signaling outputs to promote tumorigenesis. Here, we report that PDK1 directly induces phosphorylation of Polo-like kinase 1 (PLK1), which in turn induces MYC phosphorylation and protein accumulation. We show that PDK1-PLK1-MYC signaling is critical for cancer cell growth and survival, and small-molecule inhibition of PDK1/PLK1 provides an effective approach for therapeutic targeting of MYC dependency.

B55β-associated PP2A complex controls PDK1-directed myc signaling and modulates rapamycin sensitivity in colorectal cancer.

The PP2A serine/threonine protein phosphatase serves as a critical cellular regulator of cell growth, proliferation, and survival. However, how this pathway is altered in human cancer to confer growth advantage is largely unknown. Here, we show that PPP2R2B, encoding the B55β regulatory subunit of the PP2A complex, is epigenetically inactivated by DNA hypermethylation in colorectal cancer.

DACT3 is an epigenetic regulator of Wnt/beta-catenin signaling in colorectal cancer and is a therapeutic target of histone modifications.

Genetic and epigenetic defects in Wnt/beta-catenin signaling play important roles in colorectal cancer progression. Here we identify DACT3, a member of the DACT (Dpr/Frodo) gene family, as a negative regulator of Wnt/beta-catenin signaling that is transcriptionally repressed in colorectal cancer. Unlike other Wnt signaling inhibitors that are silenced by DNA methylation, DACT3 repression is associated with bivalent histone modifications.

Ribosomal protein S27-like, a p53-inducible modulator of cell fate in response to genotoxic stress.

Activation of the p53 tumor suppressor upon DNA damage elicits either cell cycle arrest or apoptosis, and the precise mechanism governing cell fate after p53 response has not been well defined. Through genomic analysis, we have identified the ribosomal protein S27-like (RPS27L) as a novel p53 transcriptional target gene. Although RPS27L mRNA levels were consistently induced after diverse p53 activating signals, its change in protein level was stimuli-dependent: it was up-regulated when cells were arrested in response to DNA-damaging agents Adriamycin or VP16 but was down-regulated when cells underwent apoptosis in response to antimetabolite agent 5-fluorouracil.

Pharmacologic disruption of Polycomb-repressive complex 2-mediated gene repression selectively induces apoptosis in cancer cells.

Polycomb-repressive complex 2 (PRC2)-mediated histone methylation plays an important role in aberrant cancer gene silencing and is a potential target for cancer therapy. Here we show that S-adenosylhomocysteine hydrolase inhibitor 3-Deazaneplanocin A (DZNep) induces efficient apoptotic cell death in cancer cells but not in normal cells. We found that DZNep effectively depleted cellular levels of PRC2 components EZH2, SUZ12, and EED and inhibited associated histone H3 Lys 27 methylation (but not H3 Lys 9 methylation).