Uveal melanoma (UM) is the most common intraocular malignancy, contributing to ∼5% of all melanomas. It arises from melanocytes in the uveal tract (choroid, ciliary body, and iris) and has a specific genetic and clinical profile. Important genetic alterations shown to drive UM pathogenesis and influence prognosis include GNAQ, GNA11, BAP1, SF3B1, and EIF1AX. In addition, monosomy 3 and 8q gains are strongly linked to poor outcomes, whereas disomy 3 and 6p gains are associated with better prognosis. Approximately half of patients with UM develop metastases, most commonly to the liver, leading to high mortality. Conventional chemotherapy has shown poor efficacy, and immune checkpoint inhibitors have demonstrated only modest benefits. The immunosuppressive tumor microenvironment, particularly in the liver, further limits treatment efficacy. NK cells offer a promising avenue to treat patients owing to their ability to recognize tumor cells independent of major histocompatibility complex. However, UM employs multiple immune evasion strategies, including the upregulation of HLA-E and the secretion of immunosuppressive factors inhibiting NK cell function. Despite these barriers, preclinical studies demonstrate that activated NK cells can reduce hepatic metastases. Emerging NK cell-based therapies, such as chimeric antigen receptor-engineered NK cells and NK cell engagers, could provide an effective therapeutic strategy to treat metastatic UM, warranting further clinical investigation.

Natural Killer (NK) cells play a critical role in regulating tumor growth, but our understanding of the mechanisms underlying their anti-tumor activity remains limited. We identified the histone methyltransferase EHMT2 as a key suppressor of NK cell-mediated cytotoxicity. EHMT2 inhibition in cancer cells enhanced NK cell-mediated elimination of diverse cancers, including uveal melanoma, breast cancer, and pancreatic cancer. EHMT2 loss increased AZGP1 and decreased TGF-β1 levels, resulting in the autocrine elevation of NKG2D ligands MICB and ULBP3, chemokines in cancer cells, and the paracrine stimulation of NK cell function. In a syngeneic pancreatic cancer model, EHMT2 inhibition suppressed tumors in an NK cell-dependent manner, as NK cell depletion restored tumor growth. This effect persisted and remained dependent on NK cells in Rag2 knockout mice (lacking T and B cells), but not in NSG mice (lacking T-, B- and NK-cells). Furthermore, EHMT2 and TGF-β1 inhibitors suppressed tumors in immunocompetent, but not in immunodeficient mice. These findings establish EHMT2 as a suppressor of NK cell-mediated anti-tumor immunity and a promising therapeutic target.

Ovarian cancer remains a leading cause of cancer-related deaths due to late-stage diagnosis and treatment resistance. While surgery and chemotherapy are standard treatments, challenges such as platinum resistance, tumor heterogeneity, and limited therapeutic options persist. Antibody-drug conjugates (ADCs) have emerged as a promising therapeutic strategy for treating ovarian cancer (OC), particularly in cases of platinum-resistant ovarian cancer (PROC). In OC, various ADCs targeting antigens such as folate receptor alpha (FRα), trophoblast cell surface antigen 2 (TROP-2), mesothelin (MSLN), sodium-dependent phosphate transport protein 2B (NaPi2b), and human epidermal growth factor receptor 2 (HER2) have shown encouraging preclinical results and significant clinical activity. However, challenges like antigen heterogeneity, off-target toxicity, and resistance mechanisms remain. This review highlights the current ADCs used in the clinic for the treatment of ovarian cancer, their challenges, and the future potential of ADC-based therapies in overcoming resistance and improving patient outcomes.

Melanoma is a highly metastatic form of skin cancer for which current therapies offer limited benefits. We show here that the histone reader ATAD2 is overexpressed in melanoma and predicts poor prognosis, and that the MAP kinase pathway, via the transcription factor E2F1, stimulates ATAD2 expression. Genetic or pharmacological inhibition of ATAD2 suppresses the growth and metastasis of BRAF and NRAS mutant melanoma. Mechanistically, we show that ATAD2 inhibition activates both distinct and common tumor-suppressive pathways in BRAF and NRAS mutant melanoma. In particular, we find that ATAD2 inhibition induces ferroptosis in both contexts by downregulating the ferroptosis suppressor GPX4. The ferroptosis inducer erastin also inhibits melanoma growth. Combining the ATAD2 inhibitor BAY-850 with the MEK inhibitor trametinib potently suppresses melanoma growth. Our study identifies ATAD2 as a key driver of melanoma and provides a rationale for targeting ATAD2 in conjunction with the MAPK pathway to treat melanoma.

Ovarian cancer (OC) is the most lethal gynecologic malignancy, characterized by multiple histological subtypes, each with distinct pathological and clinical features. Current treatment approaches include cytotoxic chemotherapies, poly(ADP-ribose) polymerase (PARP) inhibitors, bevacizumab, hormonal therapy, immunotherapy, and antibody-drug conjugates (ADCs). In this review we discuss immune evasion mechanisms in OC and the role of genetics, the tumor microenvironment, and tumor heterogeneity in influencing these processes. We also discuss the use of immunotherapies for OC treatment, either alone or in combination with other anticancer agents, with a focus on their clinical outcomes. Finally, we highlight emerging immunotherapies that have either succeeded or are on the verge of significantly impacting cancer treatment, and we discuss their potential utility in the effective treatment of OC.

RNA molecules are subject to extensive post-transcriptional modifications that fine-tune their stability, localization, and function. Among the more than 100 known RNA modifications, N6-methyladenosine (m6A) is the most abundant internal mark on eukaryotic messenger RNAs. This dynamic modification is installed by methyltransferases (“writers”), removed by demethylases (“erasers”), and interpreted by RNA-binding proteins (“readers”) to modulate gene expression. In this review, we examine the mechanisms governing m6A deposition and its broad impact on mRNA fate. We then focus on the emerging roles of m6A in shaping antitumor immune responses and discuss how targeting m6A-regulated pathways can enhance the efficacy of existing immunotherapies. Finally, we highlight recent advances and ongoing challenges in the development of drugs that target key regulators of m6A RNA modifications.

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer, associated with poor response to therapies and high mortality. We identify that phosphodiesterase 7A (PDE7A) is overexpressed in the majority of TNBCs, and a higher level of PDE7A associates with poor prognosis. The phosphatidylinositol 3-kinase (PI3K)/AKT pathway, via the transcription factor IRF1, stimulates the expression of PDE7A in TNBC cells. PDE7A inhibition attenuates TNBC growth in both cell culture and mouse models of TNBC. Inhibition of PDE7A suppresses de novo pyrimidine biosynthesis, in part through the downregulation of the enzyme dihydroorotate dehydrogenase (DHODH). DHODH suppression attenuates TNBC tumor growth, mirroring the effects of PDE7A inhibition, and ectopic DHODH expression rescues PDE7A-inhibition-induced tumor suppression. Pharmacological co-targeting of PDE7A and DHODH potently inhibits TNBC tumor growth and metastasis. These findings identify the PDE7A → DHODH →de novo pyrimidine biosynthesis pathway as a key driver of TNBC, offering additional therapeutic opportunities for TNBC patients.

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that is prone to metastasis and therapy resistance. Owing to its aggressive nature and limited availability of targeted therapies, TNBC is associated with higher mortality as compared to other forms of breast cancer. In order to develop new therapeutic options for TNBC, we characterized the factors involved in TNBC growth and progression. Here, we demonstrate that N-acylsphingosine amidohydrolase 1 (ASAH1) is overexpressed in TNBC cells and is regulated via p53 and PI3K-AKT signaling pathways. Genetic knockdown or pharmacological inhibition of ASAH1 suppresses TNBC growth and progression. Mechanistically, ASAH1 inhibition stimulates dual-specificity phosphatase 5 (DUSP5) expression, suppressing the mitogen-activated protein kinase (MAPK) pathway. Furthermore, pharmacological cotargeting of the ASAH1 and MAPK pathways inhibits TNBC growth. Collectively, we unmasked a novel role of ASAH1 in driving TNBC and identified dual targeting of the ASAH1 and MAPK pathways as a potential new therapeutic approach for TNBC treatment.

Hepatocellular carcinoma (HCC) currently lacks effective therapies, leaving a critical need for new treatment options. A previous study identified the Anaplastic Lymphoma Kinase (ALK) amplification in HCC patients, raising the question of whether ALK inhibitors could be a viable treatment. Here, we showed that both ALK inhibitors and ALK knockout effectively halted HCC growth in cell cultures. Lorlatinib, a potent ALK inhibitor, suppressed HCC tumor growth and metastasis across various mouse models. Additionally, in an advanced immunocompetent humanized mouse model, when combined with an anti-PD-1 antibody, lorlatinib more potently suppressed HCC tumor growth, surpassing individual drug efficacy. Lorlatinib induced apoptosis and senescence in HCC cells, and the senolytic agent ABT-263 enhanced the efficacy of lorlatinib. Additional studies identified that the apoptosis-inducing effect of lorlatinib was mediated via GGN and NRG4. These findings establish ALK inhibitors as promising HCC treatments, either alone or in combination with immunotherapies or senolytic agents.

Epigenetic modifications influence gene expression and effects cancer initiation and progression. Therefore, they serve as diagnostic and prognostic biomarkers and potential therapeutic targets. Natural Killer (NK) cells, integral to the innate immune system, exhibit anti-tumor effect by recognizing and eliminating cancerous cells through the balance of activating and inhibitory ligands. Understanding the epigenetic regulation of NK cell ligands offers insights into enhancing NK cell-mediated tumor eradication. This review explores the epigenetic modifications governing the expression of activating NKG2D ligands and discusses clinical trials investigating NK cell-based immunotherapies, highlighting their potential as effective cancer treatment strategies. Case studies examining the safety and effectiveness of NK cell therapies in different cancer types, such as acute myeloid leukemia (AML) and non-small cell lung cancer (NSCLC), demonstrate promising outcomes with minimal toxicity. These findings underscore the therapeutic prospects of epigenetic modulation of NKG2D ligands and NK cell-based immunotherapies as effective cancer treatment strategies. Future research in the advancement of personalized medicine approaches and novel combination therapies with NK cell will further improve treatment outcomes and provide new therapeutic options for treating patients with various types of cancer.

BackgroundCeramides are sphingolipids that act as signaling molecules involved in regulating cellular processes including apoptosis, proliferation, and metabolism. Deregulation of ceramide metabolism contributes to cancer development and progression. Therefore, regulation of ceramide levels in cancer cells is being explored as a new approach for cancer therapy.Scope of the ReviewThis review discusses the multiple roles of ceramides in cancer cells and strategies to modulate ceramide levels for cancer therapy. Ceramides attenuate cell survival signaling and metabolic pathways, while activating apoptotic mechanisms, making them tumor-suppressive. Approaches to increase ceramide levels in cancer cells include using synthetic analogs, inhibiting ceramide degradation, and activating ceramide synthesis. We also highlight combination therapies such as use of ceramide modulators with chemotherapies, immunotherapies, apoptosis inducers, and anti-angiogenics, which offer synergistic antitumor effects. Additionally, we also describe ongoing clinical trials evaluating ceramide nanoliposomes and analogs. Finally, we discuss the challenges of these therapeutic approaches including the complexity of ceramide metabolism, targeted delivery, cancer heterogeneity, resistance mechanisms, and long-term safety.Major ConclusionsCeramide-based therapy is a potentially promising approach for cancer therapy. However, overcoming hurdles in pharmacokinetics, specificity, and resistance is needed to optimize its efficacy and safety. This requires comprehensive preclinical/clinical studies into ceramide signaling, formulations, and combination therapies. Ceramide modulation offers opportunities for developing novel cancer treatments, but a deeper understanding of ceramide biology is vital to advance its clinical applications.

Oncogenic mutations in the RAS gene are associated with uncontrolled cell growth, a hallmark feature contributing to tumorigenesis. While diverse therapeutic strategies have been diligently applied to treat RAS-mutant cancers, successful targeting of the RAS gene remains a persistent challenge in the field of cancer therapy. In our study, we discover a promising avenue for addressing this challenge. In this study, we tested the viability of several cell lines carrying oncogenic NRAS, KRAS, and HRAS mutations upon treatment with IkappaBalpha (IκBα) inhibitor BAY 11-7082. We performed both cell culture-based viability assay and in vivo subcutaneous xenograft-based assay to confirm the growth inhibitory effect of BAY 11-7082. We also performed large RNA sequencing analysis to identify differentially regulated genes and pathways in the context of oncogenic NRAS, KRAS, and HRAS mutations upon treatment with BAY 11-7082. We demonstrate that oncogenic NRAS, KRAS, and HRAS activate the expression of IκBα kinase. BAY 11-7082, an inhibitor of IκBα kinase, attenuates the growth of NRAS, KRAS, and HRAS mutant cancer cells in cell culture and in mouse model. Mechanistically, BAY 11-7082 inhibitor treatment leads to suppression of the PI3K-AKT signaling pathway and activation of apoptosis in all RAS mutant cell lines. Additionally, we find that BAY 11-7082 treatment results in the downregulation of different biological pathways depending upon the type of RAS protein that may also contribute to tumor growth inhibition. Our study identifies BAY 11-7082 to be an efficacious inhibitor for treating RAS oncogene (HRAS, KRAS, and NRAS) mutant cancer cells. This finding provides new therapeutic opportunity for effective treatment of RAS-mutant cancers.

<p>Supplementary Table S1</p>

Supplementary Information includes: Supplementary Methods providing additional information on experimental techniques and data analysis; Supplementary Figures S1-S14 providing critical control experiments and raw data analyses for experiments presented in the main manuscript; and Supplementary Tables S1-S10 summarizing data presented in the main manuscript as well as listing reagents.

Intensity ratios of methylated to unmethylated DNA for TSG promoters in paired primary hLSCC (LC) and normal lung squamous cell (NL) samples from 18 individuals.

Ovarian cancer is a complex disease associated with multiple genetic and epigenetic alterations. The emergence of treatment resistance in most patients causes ovarian cancer to become incurable, and novel therapies remain necessary. We identified epigenetic regulator ATPase family AAA domain-containing 2 (ATAD2) is overexpressed in ovarian cancer and is associated with increased incidences of metastasis and recurrence. Genetic knockdown of ATAD2 or its pharmacological inhibition via ATAD2 inhibitor BAY-850 suppressed ovarian cancer growth and metastasis in both in vitro and in vivo models. Transcriptome-wide mRNA expression profiling of ovarian cancer cells treated with BAY-850 revealed that ATAD2 inhibition predominantly alters the expression of centromere regulatory genes, particularly centromere protein E (CENPE). In ovarian cancer cells, changes in CENPE expression following ATAD2 inhibition resulted in cell-cycle arrest and apoptosis induction, which led to the suppression of ovarian cancer growth. Pharmacological CENPE inhibition phenotypically recapitulated the cellular changes induced by ATAD2 inhibition, and combined pharmacological inhibition of both ATAD2 and CENPE inhibited ovarian cancer cell growth more potently than inhibition of either alone. Thus, our study identified ATAD2 as regulators of ovarian cancer growth and metastasis that can be targeted either alone or in combination with CENPE inhibitors for effective ovarian cancer therapy.

Although epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (EGFRi) are approved for treating EGFR-mutant lung adenocarcinoma (LUAD), emergence of acquired resistance limits their clinical benefits. Several mechanisms for acquired resistance to EGFRi in LUAD have been identified; however, the molecular basis for this resistance remains unknown in ~30% of LUAD. Chromatin and DNA modifiers and their regulators play important roles in determining response to anticancer therapies. Therefore, to identify nongenetic mechanisms of EGFRi resistance in LUAD, we performed an epigenome-wide shRNA screen targeting 363 human epigenetic regulator genes. This screen identified loss of the transcriptional repressor chromobox homolog 5 (CBX5) as a driver of EGFRi resistance in EGFR-mutant LUAD. Loss of CBX5 confers resistance to multiple EGFRi in both cell culture and mice. We found that CBX5 loss in EGFR-mutant LUAD cells leads to increased expression of the transcription factor E2F1, which in turn stimulates expression of the antiapoptotic gene BIRC5 ( survivin ). This E2F1-mediated upregulation of BIRC5 in CBX5 -knockdown LUAD cells attenuates apoptosis induction following EGFRi treatment. Consistent with these results, knockdown of E2F1 or BIRC5 partly rescues CBX5 -knockdown-induced EGFRi resistance in cell culture and mice. EGFRi-resistant LUAD cell lines show reduced CBX5 expression compared to parental lines; however, bromo- and extra-terminal (BET)-domain inhibitors (BETi) restore CBX5 expression in these cells and sensitize them to EGFRi/BETi combination therapy. Similarly, treatment with a BIRC5 inhibitor suppresses growth of EGFRi-resistant LUAD cells. Collectively, these studies identify CBX5 loss as a driver of EGFRi resistance and reveal therapeutic opportunities for treating EGFRi-resistant LUAD.

Intensity ratios of methylated to unmethylated DNA for TSG promoters in paired primary hLSCC (LC) and normal lung squamous cell (NL) samples from 18 individuals.

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers, which lacks effective therapies. Here, we demonstrate that the transcription factor, homeobox C6 (HOXC6), is overexpressed in most PDACs, and its inhibition blocks PDAC tumor growth and metastasis. HOXC6 transcriptionally activates tumor-promoting kinase MSK1 and suppresses tumor-inhibitory protein PPP2R2B in PDAC. HOXC6-induced PPP2R2B suppression causes mammalian target of rapamycin (mTOR) pathway activation, which facilitates PDAC growth. Also, MSK1 upregulation by HOXC6 is necessary for PDAC growth because of its ability to suppress apoptosis via its substrate DDX17. Combinatorial pharmacological inhibition of MSK1 and mTOR potently suppressed PDAC tumor growth and metastasis in PDAC mouse models. PDAC cells with acquired resistance to MSK1/mTOR-inhibitors displayed activated insulin-like growth factor 1 receptor (IGF1R) signaling and were successfully eradicated by IGF1R inhibitor. Furthermore, MEK inhibitor trametinib enhanced the efficacy of dual MSK1 and mTOR inhibition. Collectively, these results identify therapeutic vulnerabilities of PDAC and an approach to overcome acquired drug resistance to prolong therapeutic benefit.

The tumor microenvironment (TME) composed of different types of cells embedded in extracellular matrix (ECM) has crucial effects on cancer growth and metastasis. ECM is made of a variety of proteins that provide structural support to the cells and regulate biological functions by modulating the cross talk among cells, thus effecting tumor growth and progression. In this mini-review, the author discusses epigenetic modifications that regulate the expression of fibrous ECM proteins and glycoproteins and the prospects of targeting them for cancer therapy.