Although the incidence of cervical cancer (CC) has been reduced in high-income countries due to human papillomavirus (HPV) vaccination and screening strategies, it remains a significant public health issue that poses a threat to women’s health in low-income countries. Here, we perform a comprehensive proteogenomic profiling of CC tumors obtained from 139 Chinese women. Integrated proteogenomic analysis links genetic aberrations to downstream pathogenesis-related pathways and reveals the landscape of HPV-associated multi-omic changes. EP300 is found to enhance the acetylation of FOSL2-K222, consequently accelerating the malignant proliferation of CC cells. Proteomic stratification identifies three patient subgroups with distinct features in prognosis, genetic alterations, immune infiltration, and post-translational modification regulations. PRKCB is further identified as a potential radioresponse-related biomarker of CC patients. This study provides a valuable public resource for researchers and clinicians to delve into the molecular basis of CC, to identify potential treatments and to ultimately advance clinical practice. Cervical cancer remains a significant public health problem in many regions. Here, the authors perform a proteogenomic analysis of cervical cancer in Chinese patients; they reveal proteomic subgroups associated with clinical and biological features, and a potential biomarker of response to radiotherapy.
Prostate is a zinc rich organ and the physiological function of the abundant zinc ions is relatively less understood. AKT kinase is a pivotal regulator downstream of cytokines, growth factors and other extracellular stimuli, and the attachment of its PH domain to PtdIns-3,4,5-P3 (PIP3) and the subsequent phosphorylation of its kinase domain by PDPK1 are considered important for its activation. Herein, we report a regulatory mechanism of AKT kinase by zinc ions. Mechanistically, zinc ions directly bind to AKT and facilitate AKT activation through disrupting the interaction between PH and kinase domains within AKT molecule. Consistently, AKT1-H89A/E91A mutant (zinc-binding-deficient) fails to respond to zinc ions and exhibits strong interaction between PH and kinase domains, and it is less oncogenic in orthotopic xenograft model of prostate cancer. On the other hand, the AKT1-W80L mutant with minimum intra-molecular interaction between PH and kinase domains shows strong tumor promoting capacity although it could not be further stimulated by zinc ions. Overall, this study reveals a distinctive regulatory mechanism of AKT activation and implies a tumor promoting role of the zinc ions in prostate cancer.
BACKGROUND:UTX (encoded by KDM6A), a histone demethylase for H3K27me2/3, is frequently mutated in human cancers. However, its functional and regulatory mechanisms in colorectal cancer (CRC) remain unclear.METHODS:Immunohistochemistry staining was used to investigate the clinical relevance of UTX in CRC. Additionally, we generated a spontaneous mouse CRC model with conditional Utx knockout to explore the role of UTX in the colorectal tumorigenesis. Post-translational regulation of UTX was determined by co-immunoprecipitation and immunoblot analyses.RESULTS:Herein, we identify that downregulation of UTX, mediated by the Cullin 4B-DNA Damage Binding Protein-1-Constitutive Photomorphogenesis Protein 1 (CUL4B-DDB1-COP1) complex, promotes CRC progression. Utx deletion in intestinal epithelial cells enhanced the susceptibility to tumorigenesis in AOM/DSS-induced spontaneous mouse CRC model. However, this effect is primarily alleviated by GSK126, an inhibitor of histone methyltransferase EZH2. Mechanistically, EMP1 and AUTS2 are identified as putative UTX target genes mediating UTX functions in limiting intestinal tumorigenesis. Notably, the CUL4B-DDB1-COP1 complex is identified as the functional E3 ligase responsible for targeting UTX for degradation in CRC cells. Thus, Cop1 deficiency in mouse intestinal tissue results in UTX accumulation and restricts tumorigenesis. Furthermore, patient cohort analysis reveals that UTX expression is negatively correlated with clinical stage, favorable disease outcomes, and COP1 expression.CONCLUSIONS:In the current study, the tumor suppressor function and regulation of UTX in CRC provide a molecular basis and the rationale to target EZH2 in UTX-deficient CRC.
AKT kinase is a key regulator in cell metabolism and survival, and its activation is strictly modulated. Herein, we identify XAF1 (XIAP-associated factor) as a direct interacting protein of AKT1, which strongly binds the N-terminal region of AKT1 to block its K63-linked poly-ubiquitination and subsequent activation. Consistently, Xaf1 knockout causes AKT activation in mouse muscle and fat tissues and reduces body weight gain and insulin resistance induced by high-fat diet. Pathologically, XAF1 expression is low and anti-correlated with the phosphorylated p-T308-AKT signal in prostate cancer samples, and Xaf1 knockout stimulates the p-T308-AKT signal to accelerate spontaneous prostate tumorigenesis in mice with Pten heterozygous loss. And ectopic expression of wild-type XAF1, but not the cancer-derived P277L mutant, inhibits orthotopic tumorigenesis. We further identify Forkhead box O 1 (FOXO1) as a transcriptional regulator of XAF1, thus forming a negative feedback loop between AKT1 and XAF1. These results reveal an important intrinsic regulatory mechanism of AKT signaling.
Secreted isoform of endoplasmic reticulum membrane complex subunit 10 (scEMC10) is a poorly characterized secreted protein of largely unknown physiological function. Here we demonstrate that scEMC10 is upregulated in people with obesity and is positively associated with insulin resistance. Consistent with a causal role for scEMC10 in obesity, Emc10-/- mice are resistant to diet-induced obesity due to an increase in energy expenditure, while scEMC10 overexpression decreases energy expenditure, thus promoting obesity in mouse. Furthermore, neutralization of circulating scEMC10 using a monoclonal antibody reduces body weight and enhances insulin sensitivity in obese mice. Mechanistically, we provide evidence that scEMC10 can be transported into cells where it binds to the catalytic subunit of PKA and inhibits its stimulatory action on CREB while ablation of EMC10 promotes thermogenesis in adipocytes via activation of the PKA signalling pathway and its downstream targets. Taken together, our data identify scEMC10 as a circulating inhibitor of thermogenesis and a potential therapeutic target for obesity and its cardiometabolic complications.
p62/SQSTM1 (sequestosome-1) is a key protein involved in multiple cellular bioprocesses including autophagy, nutrient sensing, cell growth, cell death, and survival. Therefore, it is implicated in human diseases such as obesity and cancer. Here, we show that the CUL5–ASB6 complex is a ubiquitin E3 ligase complex mediating p62 ubiquitination and degradation. Depletion of CUL5 or ASB6 induced p62 accumulation, and overexpression of ASB6 promoted ubiquitination and degradation of p62. Functionally, ASB6 overexpression can inhibit the proliferation of MEF and hepatocellular carcinoma cells by reducing p62 protein level, and impair the occurrence of autophagy. Overall, our study identified a new molecular mechanism regulating p62 stability, which may provide additional insights for understanding the delicate control of p62 and cell proliferation–autophagy control in physiological and pathological settings.
Secreted isoform of endoplasmic reticulum membrane complex subunit 10 (scEMC10) is a poorly characterised secreted protein of largely unknown physiological function. Here we demonstrate that scEMC10 is upregulated in humans with obesity and is positively associated with insulin resistance. Consistent with a causal role for scEMC10 in obesity, Emc10-/- mice are resistant to diet-induced obesity due to an increase in energy expenditure. Furthermore, neutralization of circulating scEMC10 using a monoclonal antibody reduces body weight and enhances insulin sensitivity in obese mice. Mechanistically, we provide evidence that scEMC10 binds to the catalytic subunit of PKA and inhibits its stimulatory action on CREB while ablation of EMC10 promotes thermogenesis in adipocytes via activation of the PKA signalling pathway and its downstream targets. Taken together, our data identify scEMC10 as a novel circulating inhibitor of thermogenesis and a potential therapeutic target for obesity and its cardiometabolic complications.