Oncogene最新文献

Clear cell renal cell carcinoma (ccRCC) is characterised by significant genetic heterogeneity, which has diagnostic and prognostic implications. Very limited evidence is available regarding DNA methylation heterogeneity. We therefore generate sequence level DNA methylation data on 136 multi-region tumour and normal kidney tissue from 18 ccRCC patients, along with matched whole exome sequencing (85 samples) and gene expression (47 samples) data on a subset of samples. We perform a comprehensive systematic analysis of heterogeneity between patients, within a patient and within a sample. We demonstrate that bulk methylation data may be deconvoluted into cell-type-specific latent methylation components (LMCs), and that LMC1, which is likely to represent T cells, is associated with prognostic parameters. Differential epipolymorphism was noted between ccRCC and normal tissue in the promoter region of genes which are known to be associated with kidney cancer. This was externally validated in an independent cohort of 71 ccRCC and normal kidney tissues. Differential epipolymorphism in the gene promoter was a predictor of gene expression, after adjusting for average methylation. This represents the first evaluation of epipolymorphism in ccRCC and suggests that gains and losses in methylation disorder may have a functional relevance, gleaning important information on tumourigenesis.

The functional activation of the androgen receptor (AR) and its interplay with the aberrant Hh/Gli cascade are pivotal in the progression of castration-resistant prostate cancer (CRPC) and resistance to AR-targeted therapies. Our study unveiled a novel role of the truncated form of Gli (t-Gli3) in advancing CRPC. Investigation into Gli3 regulation revealed a Smo-independent mechanism for its activation. Despite lacking a transactivation domain, t-Gli3 relies on androgen receptor variant 7 (AR-V7) for its action. Mechanistically, Gsk3β activation led to the t-Gli3 generation, and inhibition of Gsk3β supported the accumulation of full-length Gli3 expression through a non-canonical mechanism. Knockdown of Gsk3β (Gsk3β KD) reduces CRPC cell proliferation, induces apoptosis via mitochondrial fragmentation, and triggers metabolomic reprogramming. The in vivo studies with Gsk3β KD cells in the mouse prostate resulted in tumor growth retardation compared to scramble cells. RNA-seq HALLMARK Gene Set Enrichment Analysis (GSEA) analysis of Gsk3β KD revealed a positive enrichment of apoptosis, tumor suppressor gene, and negative enrichment of oncogenic pathway. Furthermore, combinational use of a Gsk3β inhibitor with anti-Smo or Gli1 significantly inhibited the CRPC cell growth, which is resistant to individual Smo or Gli1 inhibitor targeting. Intriguingly, solely targeting Gli3 showed effectiveness in inhibiting CRPC cell growth. Overall, our study underscores the clinical significance of Gli3, emphasizing t-Gli3, and provides novel insights into the interplay of the Gsk3β/t-Gli3/AR-V7 axis in CRPC.

Mismatch repair deficiency (dMMR) cancers are highly sensitive to immunotherapy, but only account for a small fraction of cancer patients. How to increase immunotherapy efficacy on MMR-proficient (pMMR) cancer is still a major challenge. This study demonstrates that pyrithione zinc (PYZ), an FDA-approved drug, can enhance tumor immunogenicity via altering MMR and activating STING signaling. Mechanistically, PYZ elevates levels of ROS, leading to the upregulation of HIF-1α and DNA damage, while also inhibiting the expression of DNA mismatch repair proteins MSH2 and MSH6, together promoting DNA damage accumulation. Therefore, the administration of PYZ results in the accumulation of DNA damage, leading to the activation of STING signaling, which enhances tumor immunogenicity. Knockout of Sting diminishes the activation of IFN-I signaling induced by PYZ and reduces tumor immunogenicity. Furthermore, in vivo administration of PYZ promotes the infiltration of CD8⁺ T cells into the tumor and inhibits tumor growth, an effect that is attenuated in Nude mice or mice with CD8⁺ T cell depletion or deficiency of Ifnar. Overall, our findings showed that pyrithione zinc could trigger tumor immunogenicity by downregulating MMR machinery and activating STING pathway in tumor cells, and provide a translational approach to improve immunotherapy on pMMR cancer.

In recent years, circRNAs have garnered increasing attention for their role in cervical cancer. However, the functions of many newly identified circRNAs remain unclear and require further exploration. In this study, we investigated the expression and oncogenic potential of the novel circRNA circSTX6 in cervical cancer. Our findings revealed that circSTX6 is highly expressed in cervical cancer (CC) and is significantly associated with poor patient prognosis, promoting cell survival, proliferation, invasion, and migration. Mechanistically, circSTX6 enhances the stability of the transcription factor SPI1 by binding to it, thereby upregulating IL6 transcription and activating the JAK2/STAT3 signaling pathway. Additionally, METTL3-mediated N6-methyladenosine (m6A) modification stabilizes circSTX6 through recognition by YTHDC1, forming a positive feedback regulatory loop among METTL3, circSTX6, and SPI1. These findings not only deepen our understanding of the biological mechanisms underlying CC but also highlight circSTX6 as a potential target for molecular therapies.

Lung cancer is one of the most frequently diagnosed cancers in the US. African-American (AA) men are more likely to develop lung cancer with higher incidence and mortality rates than European-American (EA) men. Herein, we report high-confidence alternative splicing (AS) events from high-throughput, high-depth total RNA sequencing of lung tumors and non-tumor adjacent tissues (NATs) in two independent cohorts of patients with adenocarcinoma (LUAD) and squamous cell carcinoma (LUSC). We identified novel AS biomarkers with notable differential percent spliced in (PSI) values between lung tumors and NATs enriched in the AA and EA populations, which were associated with oncogenic signaling pathways. We also uncovered tumor subtype- and population-specific AS events associated with cell surface proteins and cancer driver genes. We highlighted significant AS events in SYNE2 specific to LUAD in both populations, as well as those in CD44 from EAs and TMBIM6 from AAs specific to LUAD. Here, we also present the validation of cancer signatures based on direct high-throughput reverse transcription-PCR. Our large survey of lung tumors presents a rich data resource that may help to understand molecular subtypes of lung tumor between AAs and EAs and reveal new therapeutic vulnerabilities that potentially advance health equity.

Insufficient tumor cell-intrinsic interferon response represents a major obstacle in immune checkpoint blockade (ICB) therapy, particularly in anti-PD-1 treatment. Although cholesterol metabolism has been demonstrated to be a critical regulator of anti-tumor immune responses, whether cholesterol influences tumor cell-intrinsic interferon response in microsatellite instability (MSI) colorectal cancer (CRC) remains unknown. Through comprehensive siRNA library screening and Gene Set Enrichment Analysis (GSEA), we identified mevalonate kinase (MVK) as a crucial negative regulator of tumor cell-intrinsic interferon response in MSI CRC cells. Genetic ablation of MVK resulted in significant upregulation of Th1 type chemokines (CXCL9 and CXCL10) and enhanced CD8⁺T cell infiltration in MSI CRC, consequently leading to marked tumor growth suppression in immunocompetent mice. At the molecular level, we demonstrated that MVK physically interacts with the transcriptional activation domain (TAD) of signal transducer and activator of transcription 1 (STAT1). This interaction substantially impairs STAT1 nuclear translocation, thereby attenuating interferon signaling cascade. Furthermore, analyses of humanized PBMC-PDX models and clinical cohorts of MSI CRC patients revealed that reduced MVK expression in tumor tissues strongly correlates with favorable responses to anti-PD-1 therapy. Collectively, our findings establish MVK as a pivotal mediator in cholesterol synthesis pathway that negatively regulates tumor cell-intrinsic interferon response in MSI CRC. These results suggest that therapeutic targeting of MVK represents a promising strategy to enhance ICB efficacy through potentiation of interferon responses in MSI CRC patients.

The MYC proto-oncogene is upregulated in >60% of triple-negative breast cancers (TNBCs), it can directly promote tumor cell proliferation, and its overexpression negatively regulates anti-tumor immune responses. For all these reasons, MYC has long been considered as a compelling therapeutic target. However, pharmacological inhibition of MYC function has proven difficult due to a lack of a drug-binding pocket. Here, we demonstrate that the potent abrogation of MYC gene transcription by CBL0137 induces immunogenic cell death and reduces proliferation in MYC-high but not in MYC-low TNBC in vitro. CBL0137 also significantly inhibited the in vivo growth of primary tumors in a human MYC-high TNBC xenograft model (MDA-MB-231). Moreover, CBL0137 inhibited the tumor growth of highly aggressive mouse 4T1.2 syngeneic TNBC model in immunocompetent mice by inhibiting the MYC pathway and inducing Type I interferon responses. Immune profiling of CBL0137-treated mice revealed significantly enhanced tumor-specific immune responses and increased proportions of tumor infiltrating effector CD8⁺ T cells, CD4⁺ T cells, and NK cells. CBL0137-induced immune activation also resulted in increased exhaustion of immune effector cells. In particular, NKG2A up-regulation on activated effector cells and of its ligand Qa-1^b on tumors in vivo was identified as a possible immune evasive mechanism. Indeed, NKG2A blockade synergized with CBL0137 significantly inhibiting the in vivo growth of 4T1.2 tumors. Collectively, our findings provide the rationale supporting the exploitation of CBL0137-induced anti-tumor immunity in combination with NKG2A blockade to improve the treatment of TNBC expressing high levels of MYC.