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1.
bioRxiv ; 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38979330

RESUMO

Variants in the poorly characterised oncoprotein, MORC2, a chromatin remodelling ATPase, lead to defects in epigenetic regulation and DNA damage response. The C-terminal domain (CTD) of MORC2, frequently phosphorylated in DNA damage, promotes cancer progression, but its role in chromatin remodelling remains unclear. Here, we report a molecular characterisation of full-length, phosphorylated MORC2, demonstrating its preference for binding open chromatin and functioning as a DNA sliding clamp. We identified a phosphate interacting motif within the CTD that dictates ATP hydrolysis rate and cooperative DNA binding. The DNA binding impacts several structural domains within the ATPase region. We provide the first visual proof that MORC2 induces chromatin remodelling through ATP hydrolysis-dependent DNA compaction, regulated by its phosphorylation state. These findings highlight phosphorylation of MORC2 CTD as a key modulator of chromatin remodelling, presenting it as a potential therapeutic target.

2.
J Neurosurg Pediatr ; 33(6): 610-618, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38457794

RESUMO

OBJECTIVE: Posttraumatic headache (PTH) represents the most common acute and persistent symptom in children after concussion, yet there is no blood protein signature to stratify the risk of PTH after concussion to facilitate early intervention. This discovery study aimed to identify capillary blood protein markers, at emergency department (ED) presentation within 48 hours of concussion, to predict children at risk of persisting PTH at 2 weeks postinjury. METHODS: Capillary blood was collected using the Mitra Clamshell device from children aged 8-17 years who presented to the ED of the Royal Children's Hospital, Melbourne, Australia, within 48 hours of sustaining a concussion. Participants were followed up at 2 weeks postinjury to determine PTH status. PTH was defined per clinical guidelines as a new or worsened headache compared with preinjury. An untargeted proteomics analysis using data-independent acquisition (DIA) was performed. Principal component analysis and hierarchical clustering were used to reduce the dimensionality of the protein dataset. RESULTS: A total of 907 proteins were reproducibly identified from 82 children within 48 hours of concussion. The mean participant age was 12.78 years (SD 2.54 years, range 8-17 years); 70% of patients were male. Eighty percent met criteria for acute PTH in the ED, while one-third of participants with follow-up experienced PTH at 2 weeks postinjury (range 8-16 days). Hemoglobin subunit zeta (HBZ), cystatin B (CSTB), beta-ala-his dipeptidase (CNDP1), hemoglobin subunit gamma-1 (HBG1), and zyxin (ZYX) were weakly associated with PTH at 2 weeks postinjury based on up to a 7% increase in the PTH group despite nonsignificant Benjamini-Hochberg adjusted p values. CONCLUSIONS: This discovery study determined that no capillary blood protein markers, measured at ED presentation within 48 hours of concussion, can predict children at risk of persisting PTH at 2 weeks postinjury. While HBZ, CSTB, CNDP1, HBG1, and ZYX were weakly associated with PTH at 2 weeks postinjury, there was no specific blood protein signature predictor of PTH in children after concussion. There is an urgent need to discover new blood biomarkers associated with PTH to facilitate risk stratification and improve clinical management of pediatric concussion.


Assuntos
Biomarcadores , Concussão Encefálica , Cefaleia Pós-Traumática , Humanos , Criança , Masculino , Adolescente , Feminino , Biomarcadores/sangue , Concussão Encefálica/sangue , Concussão Encefálica/complicações , Cefaleia Pós-Traumática/etiologia , Cefaleia Pós-Traumática/sangue , Proteômica , Capilares
3.
Cell Death Dis ; 15(3): 182, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38429264

RESUMO

Caspase-2, one of the most evolutionarily conserved members of the caspase family, is an important regulator of the cellular response to oxidative stress. Given that ferroptosis is suppressed by antioxidant defense pathways, such as that involving selenoenzyme glutathione peroxidase 4 (GPX4), we hypothesized that caspase-2 may play a role in regulating ferroptosis. This study provides the first demonstration of an important and unprecedented function of caspase-2 in protecting cancer cells from undergoing ferroptotic cell death. Specifically, we show that depletion of caspase-2 leads to the downregulation of stress response genes including SESN2, HMOX1, SLC7A11, and sensitizes mutant-p53 cancer cells to cell death induced by various ferroptosis-inducing compounds. Importantly, the canonical catalytic activity of caspase-2 is not required for its role and suggests that caspase-2 regulates ferroptosis via non-proteolytic interaction with other proteins. Using an unbiased BioID proteomics screen, we identified novel caspase-2 interacting proteins (including heat shock proteins and co-chaperones) that regulate cellular responses to stress. Finally, we demonstrate that caspase-2 limits chaperone-mediated autophagic degradation of GPX4 to promote the survival of mutant-p53 cancer cells. In conclusion, we document a novel role for caspase-2 as a negative regulator of ferroptosis in cells with mutant p53. Our results provide evidence for a novel function of caspase-2 in cell death regulation and open potential new avenues to exploit ferroptosis in cancer therapy.


Assuntos
Caspase 2 , Ferroptose , Caspase 2/genética , Morte Celular/genética , Chaperonas Moleculares , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/genética , Proteína Supressora de Tumor p53/genética , Ferroptose/genética
4.
Int J Mol Sci ; 25(6)2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38542101

RESUMO

There are a limited number of clinically useful serum biomarkers to predict tumor onset or treatment response in gastric cancer (GC). For this reason, we explored the serum proteome of the gp130Y757F murine model of intestinal-type gastric cancer (IGC). We identified 30 proteins with significantly elevated expression in early gp130Y757F IGC and 12 proteins that were significantly elevated in late gp130Y757F IGC compared to age- and gender-matched wild-type mice. Within these signatures, there was an overlap of 10 proteins commonly elevated in both early- and late-stage disease. These results highlight the potential to identify serum biomarkers of disease stage. Since IGC in the gp130Y757F model can be reversed following therapeutic inhibition of Interleukin (IL)-11, we explored whether the protein signatures we identified could be used to monitor tumor regression. We compared two different therapeutic modalities and found 5 proteins to be uniquely differentially expressed between control animals and animals halfway through treatment, with 10 differentially expressed at the end of treatment. Our findings highlight the potential to identify reliable biomarkers to track IGC tumor regression in response to treatment.


Assuntos
Transdução de Sinais , Neoplasias Gástricas , Camundongos , Animais , Transdução de Sinais/fisiologia , Neoplasias Gástricas/patologia , Receptor gp130 de Citocina/metabolismo , Biomarcadores , Biomarcadores Tumorais
5.
Eur J Oncol Nurs ; 68: 102471, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38016202

RESUMO

PURPOSE: The aim of this study is to assess the impact of lavender oil on odor elimination, ostomy adjustment and quality of life outcomes in patients with permanent colostomy. Specifically, the study aims to compare the outcomes of an experimental group receiving lavender oil intervention with those of a control group. METHODS: A randomized controlled trial design was employed, including an experimental group receiving lavender oil intervention and a control group receiving standard care. The study participants were patients with permanent colostomy. Various variables were assessed, including odor scale, work and social functioning, sexuality and body image, stoma function, financial concerns, acceptance, anxiety/preoccupation, social engagement and anger. RESULTS: The post-scores assessment showed significant differences between the experimental and control groups in all variables. The experimental group exhibited significantly more positive outcomes concerning the reduction of odor (p<0.001), performance in the workplace (p<0.001), body image connected to sexuality (p<0.001), stoma functionality (p<0.001), financial worries (p=0.005), acceptance levels (p<0.001), anxiety levels (p<0.001), social involvement (p<0.001), and irritability (p<0.001). Effect sizes were substantial (=0.88-0.98 in all variables but one), indicating significant differences in average scores before and after the intervention. CONCLUSION: The findings of this study suggest that lavender oil intervention effectively improved odor elimination, ostomy adjustment and quality of life outcomes in patients with permanent colostomy.


Assuntos
Colostomia , Lavandula , Óleos Voláteis , Estomia , Óleos de Plantas , Humanos , Colostomia/efeitos adversos , Qualidade de Vida , Odorantes
6.
PNAS Nexus ; 3(1): pgad438, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38156288

RESUMO

Skin inflammation is a complex process implicated in various dermatological disorders. The chronic proliferative dermatitis (cpd) phenotype driven by the cpd mutation (cpdm) in the Sharpin gene is characterized by dermal inflammation and epidermal abnormalities. Tumour necrosis factor (TNF) and caspase-8-driven cell death causes the pathogenesis of Sharpincpdm mice; however, the role of mind bomb 2 (MIB2), a pro-survival E3 ubiquitin ligase involved in TNF signaling, in skin inflammation remains unknown. Here, we demonstrate that MIB2 antagonizes inflammatory dermatitis in the context of the cpd mutation. Surprisingly, the role of MIB2 in limiting skin inflammation is independent of its known pro-survival function and E3 ligase activity. Instead, MIB2 enhances the production of wound-healing molecules, granulocyte colony-stimulating factor, and Eotaxin, within the skin. This discovery advances our comprehension of inflammatory cytokines and chemokines associated with cpdm pathogenesis and highlights the significance of MIB2 in inflammatory skin disease that is independent of its ability to regulate TNF-induced cell death.

8.
Cell Death Differ ; 30(5): 1155-1165, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36828915

RESUMO

Epithelial-mesenchymal transition (EMT) is a continuum that includes epithelial, partial EMT, and mesenchymal states, each of which is associated with cancer progression, invasive capabilities, and ultimately, metastasis. We used a lineage-traced sporadic model of pancreatic cancer to generate a murine organoid biobank from primary and secondary tumors, including sublines that underwent partial EMT and complete EMT. Using an unbiased proteomics approach, we found that organoid morphology predicts the EMT state, and the solid organoids are associated with a partial EMT signature. We also observed that exogenous TGFß1 induces solid organoid morphology that is associated with changes in the S100 family, complete EMT, and the formation of high-grade tumors. S100A4 may be a useful biomarker for predicting EMT state, disease progression, and outcome in patients with pancreatic cancer.


Assuntos
Neoplasias Pancreáticas , Proteínas S100 , Humanos , Animais , Camundongos , Proteínas S100/genética , Proteínas S100/metabolismo , Transição Epitelial-Mesenquimal , Neoplasias Pancreáticas/patologia , Linhagem Celular Tumoral , Neoplasias Pancreáticas
9.
Cancer Immunol Res ; 10(9): 1047-1054, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35759796

RESUMO

Antibodies targeting "immune checkpoints" have revolutionized cancer therapy by reactivating tumor-resident cytotoxic lymphocytes, primarily CD8+ T cells. Interest in targeting analogous pathways in other cytotoxic lymphocytes is growing. Natural killer (NK) cells are key to cancer immunosurveillance by eradicating metastases and driving solid tumor inflammation. NK-cell antitumor function is dependent on the cytokine IL15. Ablation of the IL15 signaling inhibitor CIS (Cish) enhances NK-cell antitumor immunity by increasing NK-cell metabolism and persistence within the tumor microenvironment (TME). The TME has also been shown to impair NK-cell fitness via the production of immunosuppressive transforming growth factor ß (TGFß), a suppression which occurs even in the presence of high IL15 signaling. Here, we identified an unexpected interaction between CIS and the TGFß signaling pathway in NK cells. Independently, Cish- and Tgfbr2-deficient NK cells are both hyperresponsive to IL15 and hyporesponsive to TGFß, with dramatically enhanced antitumor immunity. Remarkably, when both these immunosuppressive genes are simultaneously deleted in NK cells, mice are largely resistant to tumor development, suggesting that combining suppression of these two pathways might represent a novel therapeutic strategy to enhance innate anticancer immunity.


Assuntos
Interleucina-15 , Neoplasias , Animais , Linhagem Celular Tumoral , Interleucina-15/metabolismo , Células Matadoras Naturais , Camundongos , Neoplasias/patologia , Fator de Crescimento Transformador beta/metabolismo , Microambiente Tumoral
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