UBQLN4 promotes STING proteasomal degradation during cisplatin-induced DNA damage in triple-negative breast cancer.
Ontology highlight
ABSTRACT:
SUBMITTER: Shoji Y
PROVIDER: S-EPMC9286529 | biostudies-literature | 2022 Jul
REPOSITORIES: biostudies-literature
Publications
UBQLN4 promotes STING proteasomal degradation during cisplatin-induced DNA damage in triple-negative breast cancer.
Shoji Yoshiaki Y Yokoe Takamichi T Kobayashi Yuta Y Murakami Tomohiro T Bostick Peter J PJ Shiloh Yosef Y Hoon Dave S B DSB Bustos Matias A MA
Clinical and translational medicine 20220701 7
Similar Datasets
Project description:The majority of transmembrane proteins are integrated into the endoplasmic reticulum (ER) by virtue of a signal sequence-mediated co-translational process. However, a substantial portion of transmembrane proteins fails to reach the ER, leading to mislocalized cytosolic polypeptides. Their appropriate recognition and removal are of the utmost importance to avoid proteotoxic stress. Here, we identified UBQLN4 as a BAG6-binding factor that eliminates newly synthesized defective polypeptides. Using a truncated transmembrane domain protein whose degradation occurs during a pre-ER incorporation process as a model, we show that UBQLN4 recognizes misassembled proteins in the cytoplasm and targets these to the proteasome. We suggest that the exposed transmembrane segment of the defective polypeptides is essential for the UBQLN4-mediated substrate discrimination. Importantly, UBQLN4 recognizes not only the defective model substrate but also a pool of endogenous defective proteins that were induced by the depletion of the SRP54 subunit of the signal recognition particle. This study identifies a novel quality control mechanism for newly synthesized and defective transmembrane domain polypeptides that fail to reach their correct destination at the ER membrane.
| S-EPMC5278606 | biostudies-literature
Project description:DCAF13 is firstly identified as a substrate receptor of CUL4-DDB1 E3 ligase complex. This study disclosed that DCAF13 acted as a novel RNA binding protein (RBP) that contributed to triple-negative breast cancer (TNBC) metastasis. Clinical data obtained from TCGA and our collection showed that DCAF13 was closely correlated with poor clinicopathological characteristics and overall survival, which indicated DCAF13 may serve as a diagnostic marker for TNBC metastasis. Functionally, DCAF13 overexpression or suppression was sufficient to enhance or decrease breast cancer cell migration and invasion. Mechanistically, DCAF13 functioned as an RBP by binding with the AU-rich element (ARE) of DTX3 mRNA 3'UTR to accelerate its degradation. Moreover, we identified that DTX3 promoted the ubiquitination and degradation of NOTCH4. Finally, increased DCAF13 expression led to post-transcriptional decay of DTX3 mRNA and consequently activated of NOTCH4 signaling pathway in TNBC. In conclusion, these results identified that DCAF13 as a diagnostic marker and therapeutic target for TNBC treatment. Abbreviation: DCAF13: DDB1 and CUL4-associated factor 13; DDB1: DNA-binding protein 1; CUL4: Cullin 4; CRL4, Cullin-ring finger ligase 4; RBP: RNA binding protein; TNBC: triple-negative breast cancer; ARE: AU-rich element; DTX3: Deltex E3 ubiquitin ligase 3; HER2: human epidermal growth factor receptor 2; ER: estrogen receptor; PR: progesterone receptor; PTEN: phosphatase and tensin homolog deleted on chromosome 10; EMT: epithelial-mesenchymal transition.
| S-EPMC7781530 | biostudies-literature
Project description:Chemoresistance constitutes a major challenge in the treatment of triple-negative breast cancer (TNBC). Mixed-Lineage Kinase 4 (MLK4) is frequently amplified or overexpressed in TNBC where it facilitates the aggressive growth and migratory potential of breast cancer cells. However, the functional role of MLK4 in resistance to chemotherapy has not been investigated so far. Here, we demonstrate that MLK4 promotes TNBC chemoresistance by regulating the pro-survival response to DNA-damaging therapies. We observed that MLK4 knock-down or inhibition sensitized TNBC cell lines to chemotherapeutic agents in vitro. Similarly, MLK4-deficient cells displayed enhanced sensitivity towards doxorubicin treatment in vivo. MLK4 silencing induced persistent DNA damage accumulation and apoptosis in TNBC cells upon treatment with chemotherapeutics. Using phosphoproteomic profiling and reporter assays, we demonstrated that loss of MLK4 reduced phosphorylation of key DNA damage response factors, including ATM and CHK2, and compromised DNA repair via non-homologous end-joining pathway. Moreover, our mRNA-seq analysis revealed that MLK4 is required for DNA damage-induced expression of several NF-кB-associated cytokines, which facilitate TNBC cells survival. Lastly, we found that high MLK4 expression is associated with worse overall survival of TNBC patients receiving anthracycline-based neoadjuvant chemotherapy. Collectively, these results identify a novel function of MLK4 in the regulation of DNA damage response signaling and indicate that inhibition of this kinase could be an effective strategy to overcome TNBC chemoresistance.
| S-EPMC8627512 | biostudies-literature
Project description:PURPOSE Cisplatin is a chemotherapeutic agent not used routinely for breast cancer treatment. As a DNA cross-linking agent, cisplatin may be effective treatment for hereditary BRCA1-mutated breast cancers. Because sporadic triple-negative breast cancer (TNBC) and BRCA1-associated breast cancer share features suggesting common pathogenesis, we conducted a neoadjuvant trial of cisplatin in TNBC and explored specific biomarkers to identify predictors of response. PATIENTS AND METHODS Twenty-eight women with stage II or III breast cancers lacking estrogen and progesterone receptors and HER2/Neu (TNBC) were enrolled and treated with four cycles of cisplatin at 75 mg/m(2) every 21 days. After definitive surgery, patients received standard adjuvant chemotherapy and radiation therapy per their treating physicians. Clinical and pathologic treatment response were assessed, and pretreatment tumor samples were evaluated for selected biomarkers. Results Six (22%) of 28 patients achieved pathologic complete responses, including both patients with BRCA1 germline mutations;18 (64%) patients had a clinical complete or partial response. Fourteen (50%) patients showed good pathologic responses (Miller-Payne score of 3, 4, or 5), 10 had minor responses (Miller-Payne score of 1 or 2), and four (14%) progressed. All TNBCs clustered with reference basal-like tumors by hierarchical clustering. Factors associated with good cisplatin response include young age (P = .001), low BRCA1 mRNA expression (P = .03), BRCA1 promoter methylation (P = .04), p53 nonsense or frameshift mutations (P = .01), and a gene expression signature of E2F3 activation (P = .03). CONCLUSION Single-agent cisplatin induced response in a subset of patients with TNBC. Decreased BRCA1 expression may identify subsets of TNBCs that are cisplatin sensitive. Other biomarkers show promise in predicting cisplatin response.
| S-EPMC2834466 | biostudies-literature
Project description:Anti-neoplastic effect of DNA cross-linking agents such as cisplatin, mitomycin C, and psoralen is attributed to their ability to induce DNA interstrand cross-links (ICLs), which block replication, transcription, and linear repair pathways by preventing DNA strand separation and trigger apoptosis. It is generally agreed that the Fanconi anemia (FA) pathway orchestrates the removal of ICLs by the combined actions of various DNA repair pathways. Recently, attention has been focused on the ability of the NEIL3-initiated base excision repair pathway to resolve psoralen- and abasic site-induced ICLs in an FA-independent manner. Intriguingly, overexpression of NEIL3 is associated with chemo-resistance and poor prognosis in many solid tumors. Here, using loss- and gain-of-function approaches, we demonstrate that NEIL3 confers resistance to cisplatin and participates in the removal of cisplatin-DNA adducts. Proteomic studies reveal that the NEIL3 protein interacts with the 26S proteasome in a cisplatin-dependent manner. NEIL3 mediates proteasomal degradation of WRNIP1, a protein involved in the early step of ICL repair. We propose that NEIL3 participates in the repair of ICL-stalled replication fork by recruitment of the proteasome to ensure a timely transition from lesion recognition to repair via the degradation of early-step vanguard proteins.
| S-EPMC10063580 | biostudies-literature
Project description:HORMA domain‑containing protein 1 (HORMAD1), is normally expressed only in the germline, but is frequently re‑activated in human triple‑negative breast cancer (TNBC); however, its function in TNBC is largely unknown. In the present study, the expression and biological significance of HORMAD1 in human TNBC was evaluated. Bioinformatics analysis and reverse transcription‑quantitative PCR were used to evaluate HORMAD1 expression in datasets and cell lines. HORMAD1 protein expression was detected in TNBC samples using immunohistochemical assays, and the effect of HORMAD1 on cell proliferation was determined using Cell Counting Kit‑8, plate colony formation and standard growth curve assays. Cell cycle, reactive oxygen species (ROS) and apoptosis analyses were conducted using flow cytometry. The activity of caspases was measured using caspase activity assay kit. The levels of key apoptosis regulators and autophagy markers were detected by western blot analysis. TNBC cell survival and apoptosis were not influenced by small interfering RNA targeting HORMAD1 alone; however, HORMAD1 knockdown enhanced autophagy and docetaxel (Doc)‑induced apoptosis, compared with the control group. Furthermore, higher ROS levels and caspase‑3, ‑8 and ‑9 activity were detected in MDA‑MB‑436 TNBC cells with HORMAD1 knockdown upon exposure to Doc. The levels of the induced DNA damage marker γH2AX were also higher, while those of the DNA repair protein RAD51 were lower in TNBC cells with HORMAD1 knockdown compared with the controls. Furthermore, the expression of the autophagy marker P62 was enhanced in MDA‑MB‑231 cells in response to HORMAD1 overexpression. Notably, Doc‑induced apoptosis was similarly increased by both HORMAD1 overexpression and treatment with the autophagy inhibitor, 3‑methyladenine (3MA); however, the Doc‑induced increase in autophagy was not inhibited by 3MA. The present data indicated that HORMAD1 was involved in autophagy and that the inhibition of autophagy can partially enhance the induction of apoptosis by Doc. The role of HORMAD1 in the DNA damage tolerance of tumor cells may be the main reason for Doc resistance; hence, HORMAD1 could be an important therapeutic target in TNBC.
| S-EPMC8165579 | biostudies-literature
Project description:Transmembrane prostate androgen-induced protein (TMEPAI), also known as PMEPA1, is highly expressed in many types of cancer and promotes oncogenic abilities. However, the mechanisms whereby TMEPAI facilitates tumorigenesis are not fully understood. We previously established TMEPAI-knockout (KO) cells from human triple-negative breast cancer (TNBC) cell lines and found that TMEPAI-KO cells showed reduced tumorigenic abilities. Here, we report that TMEPAI-KO cells upregulated the expression of pleckstrin homology (PH) domain and leucine-rich repeat protein phosphatase 1 (PHLPP1) and suppressed AKT Ser473 phosphorylation, which was consistent with TCGA dataset analysis. Additionally, the knockdown (KD) of PHLPP1 in TMEPAI-KO cells partially but significantly rescued AKT Ser473 phosphorylation, as well as in vitro and in vivo tumorigenic activities, thus showing that TMEPAI functions as an oncogenic protein through the regulation of PHLPP1 subsequent to AKT activation. Furthermore, we demonstrated that TMEPAI PPxY (PY) motifs are essential for binding to NEDD4-2, an E3 ubiquitin ligase, and PHLPP1-downregulatory ability. Moreover, TMEPAI enhanced the complex formation of PHLPP1 with NEDD4-2 and PHLPP1 polyubiquitination, which leads to its proteasomal degradation. These findings indicate that the PY motifs of TMEPAI suppress the amount of PHLPP1 and maintain AKT Ser473 phosphorylation at high levels to enhance the tumorigenic potentiality of TNBC.
| S-EPMC8508116 | biostudies-literature
Project description:Triple-negative breast cancer (TNBC) is the deadliest subtype of breast cancer owing to the lack of effective therapeutic targets. Splicing factor 3a subunit 2 (SF3A2), a poorly defined splicing factor, was notably elevated in TNBC tissues and promoted TNBC progression, as confirmed by cell proliferation, colony formation, transwell migration, and invasion assays. Mechanistic investigations revealed that E3 ubiquitin-protein ligase UBR5 promoted the ubiquitination-dependent degradation of SF3A2, which in turn regulated UBR5, thus forming a feedback loop to balance these two oncoproteins. Moreover, SF3A2 accelerated TNBC progression by, at least in part, specifically regulating the alternative splicing of makorin ring finger protein 1 (MKRN1) and promoting the expression of the dominant and oncogenic isoform, MKRN1-T1. Furthermore, SF3A2 participated in the regulation of both extrinsic and intrinsic apoptosis, leading to cisplatin resistance in TNBC cells. Collectively, these findings reveal a previously unknown role of SF3A2 in TNBC progression and cisplatin resistance, highlighting SF3A2 as a potential therapeutic target for patients with TNBC.
| S-EPMC10990288 | biostudies-literature
Project description:CD44 is associated with a high risk of metastasis, recurrence, and drug resistance in various cancers. Here we report that platelet endothelial aggregation receptor 1 (PEAR1) is a CD44 chaperone protein that protected CD44 from endocytosis-mediated degradation and enhances cleavage of the CD44 intracellular domain (CD44-ICD). Furthermore, we found that lysyl oxidase-like protein 2 (LOXL2), an endogenous ligand of PEAR1, bound to the PEAR1-EMI domain and facilitated the interaction between PEAR1 and CD44 by inducing PEAR1 Ser891 phosphorylation in a manner that was independent of its enzyme activity. Levels of PEAR1 protein and PEAR1 phosphorylation at Ser891 were increased in patients with triple-negative breast cancer (TNBC), were positively correlated with expression of LOXL2 and CD44, and were negatively correlated with overall survival. The level of PEAR1 Ser891 phosphorylation was identified as the best independent prognostic factor in TNBC patients. The prognostic efficacy of the combination of PEAR1 phosphorylation at Ser891 and CD44 expression was superior to that of PEAR1 phosphorylation at Ser891 alone. Blocking the interaction between LOXL2 and PEAR1 with monoclonal antibodies significantly inhibited TNBC metastasis, representing a promising therapeutic strategy for TNBC.
| S-EPMC11324313 | biostudies-literature
Project description:Tumor necrosis factor alpha-induced protein 8 (TNFAIP8) is implicated in the tumor progression and prognosis of triple-negative breast cancer (TNBC), but the detailed regulatory mechanism of TNFAIP8 in cisplatin tolerance in TNBC has not yet been investigated. TNFAIP8 was evidently upregulated in TNBC tumor tissues and cell lines. Knocking down TNFAIP8 led to impaired proliferation and elevated apoptosis of TNBC cells upon cisplatin (DDP) treatment. Mechanistic studies revealed that TNFAIP8 repressed the expression of p53 and p53-promoted microRNA (miR)-205-5p; moreover, miR-205-5p targeted multiple genes required for the cell cycle and repressed Akt phosphorylation, which thus inhibited the proliferation of TNBC cells. In addition, silencing of TNFAIP8 led to the upregulation of miR-205-5p and the restraint of the TRAF2-NF-κB pathway, which thus enhanced the suppressive effects of DDP on tumor growth in nude mice. This study revealed that TNFAIP8 was essential in the DDP tolerance formation of TNBC cells by reducing p53-promoted miR-205-5p expression. Thus, targeting TNFAIP8 might become a promising strategy to suppress TNBC progression.
| S-EPMC7581818 | biostudies-literature