Identification and validation of a prognostic model based on ferroptosis-associated genes in head and neck squamous cancer

Deciphering a proliferation-essential gene signature based on CRISPR-Cas9 screening to predict prognosis and characterize the immune microenvironment in HNSCC

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is a highly aggressive malignancy with a poor prognosis. Identifying reliable prognostic biomarkers and therapeutic targets is crucial for improving patient outcomes. This study aimed to systematically identify proliferation-essential genes (PEGs) associated with HNSCC prognosis using CRISPR-Cas9 screening data.

METHODS

CRISPR-Cas9 screening data from the DepMap database were used to identify PEGs in HNSCC cells. A prognostic PEGs signature was constructed using univariate Cox regression, least absolute shrinkage and selection operator (LASSO) Cox regression, and multivariate Cox regression analyses. The predictive accuracy of the signature was validated in internal and external datasets. Weighted gene co-expression network analysis (WGCNA), gene set enrichment analysis (GSEA), and immune infiltration analysis were used to investigate the underlying mechanism between high and low-risk patients. Random forest analysis and functional experiments were conducted to investigate the role of key proliferation essential genes in HNSCC progression.

RESULTS

A total of 1511 PEGs were identified. A seven-gene prognostic PEGs signature (MRPL33, NAT10, PSMC1, PSMD11, RPN2, TAF7, and ZNF335) was developed and validated, demonstrating robust prognostic performance in stratifying HNSCC patients by survival risk. WGCNA and GSEA analyses revealed a marked downregulation of immune-related pathways in high-risk patients. Immune infiltration analysis validated those high-risk patients had reduced immune scores, stromal scores, and ESTIMATE scores, as well as decreased infiltration of multiple immune cell types. Among the identified genes, PSMC1 was highlighted as a pivotal regulator of HNSCC proliferation and migration, as confirmed by functional experiments.

CONCLUSIONS

This study identifies a novel PEGs signature that effectively predicts HNSCC prognosis and stratifies patients by survival risk. PSMC1 was identified as a key gene promoting malignant progression, offering potential as a therapeutic target for HNSCC.

MALSU1-mediated regulation of mitochondrial function governs proliferation and doxorubicin resistance in triple-negative breast cancer cells

Triple-negative breast cancer (TNBC) poses a formidable challenge in oncology due to its aggressive nature and limited treatment options. Although doxorubicin, a widely used chemotherapeutic agent, shows efficacy in TNBC treatment, acquired resistance remains a significant obstacle. Our study explores the role of MALSU1, a regulator of mitochondrial translation, in TNBC and its impact on cell proliferation and doxorubicin resistance. We observed increased MALSU1 expression in TNBC, correlating with poor patient prognosis. MALSU1 knockdown in TNBC cells significantly reduced proliferation, indicating its pivotal role in sustaining cell growth. Mechanistically, MALSU1 depletion resulted in decreased activities of mitochondrial respiratory chain complexes, cellular ATP levels, and mitochondrial respiration. Notably, exogenous addition of normal mitochondria restored proliferation and mitochondrial respiration in MALSU1-depleted TNBC cells. Importantly, MALSU1 knockdown enhanced the sensitivity of doxorubicin-resistant TNBC cells to doxorubicin treatment. Furthermore, pharmacological inhibition of mitochondrial translation using tigecycline and chloramphenicol mimicked the effects of MALSU1 knockdown, suggesting mitochondrial translation as a potential therapeutic target. Taken together, our findings not only elucidate the intricate role of MALSU1 in TNBC biology and doxorubicin resistance but also lay the groundwork for future investigations targeting MALSU1 and/or mitochondrial translation as a promising avenue for developing innovative therapeutic strategies against TNBC.

Angiotensin 1-7 restrains vascular injury of extracorporeal membrane oxygenation by inhibiting ferroptosis

BACKGROUND

Angiotensin 1-7 (Ang1-7) is the classical end product of angiotensin II, which has the effects of dilating blood vessels, protecting endothelial cells, anti-hypertension, improving cardiac function, and inhibiting atherosclerosis. We hypothesize that Ang1-7 inhibits human umbilical vein endothelial cells (HUVEC) ferroptosis through NF-κB/P53 signal pathway, and reduces extracorporeal membrane oxygenation (ECMO) vascular injury.

METHODS

Cultured HUVEC were seeded into 15 wells and randomly divided into five groups: the control group and four experimental groups (erastin, erastin + Ang1-7, erastin + Ang1-7 + Betulinic acid, erastin + Betulinic acid). After stimulation, cell viability, lactate dehydrogenase (LDH), malondialdehyde (MDA), and superoxide dismutase (SOD) activity were measured. The effects of Ang1-7 on HUVEC microstructure, antioxidant enzymes (ferritin heavy chain 1 (FTH1), cystine/glutamic acid reverse transport solute carrier family 7 members 11 (SLC7A11 or XCT), superoxide dismutase-2 (SOD-2) and glutathione peroxidase 4 (GPX4)), NF-κB, P-NF-κB, P53, and P-P53).

RESULTS

Erastin stimulation promoted HUVEC lipid peroxidation, decreased antioxidant enzyme expression, increased P-NF-κB, P53, and P-P53 expressions, and damaged HUVEC mitochondrial structure. Ang1-7 alleviated the effect of erastin on HUVEC, which was destroyed by Betulinic acid.

CONCLUSION

Angiotensin1-7 pretreatment inhibited vascular endothelial cells' ferroptosis and alleviated ECMO vessel injury through NF-κB /P53 signal pathway.

Urinary proteomics for noninvasive monitoring of biomarkers of chronic mountain sickness in a young adult population using data-independent acquisition (DIA)-based mass spectrometry

Different populations exhibit varying pathophysiological responses to plateau environments. Therefore, it is crucial to identify molecular markers in body fluids with high specificity and sensitivity to aid in determination. Proteomics offers a fresh perspective for investigating protein changes linked to diseases. We utilize urine as a specific biomarker for early chronic mountain sickness (CMS) detection, as it is a simple-to-collect biological fluid. We collected urine samples from three groups: plains health, plateau health and CMS. Using DIA's proteomic approach, we found differentially expressed proteins between these groups, which will be used as a basis for future studies to identify protein markers. Compared with the healthy plain population, 660 altering proteins were identified in plateau health, which performed the resistance to altitude response function by boosting substance metabolism and reducing immune stress function. Compared to the healthy plateau population, the CMS group had 140 different proteins identified, out of which 8 were potential biomarkers for CMS. Our study has suggested that CMS may be closely related to increased thyroid hormone levels, oxidative damage to the mitochondria, impaired cell detoxification function and inhibited hydrolase activity. SIGNIFICANCE: Our team has compiled a comprehensive dataset of urine proteomics for AMS disease. We successfully identified differentially expressed proteins between healthy and AMS groups using the DIA proteomic approach. We discovered that 660 proteins were altered in plateau health compared to the healthy plain population, resulting in a heightened resistance to altitude response function by boosting substance metabolism and reducing immune stress function. Additionally, we pinpointed 140 different proteins in the AMS group compared to the healthy plateau population, with 8 showing potential as biomarkers for AMS. Our findings suggest that the onset of AMS may be closely linked to increased thyroid hormone levels, oxidative damage to the mitochondria, impaired cell detoxification function and inhibited hydrolase activity.

A novel oxidative stress-related gene signature as an indicator of prognosis and immunotherapy responses in HNSCC

PURPOSE

To identify molecular subtypes of oxidative stress-related genes in head and neck squamous cell carcinoma (HNSCC) and to construct a scoring model of oxidative stress-related genes.

METHODS

R language based scRNA-seq and bulk RNA-seq analyses were used to identify molecular isoforms of oxidative stress-related genes in HNSCC. An oxidative stress-related gene scoring (OSRS) model was constructed, which were verified through online data and immunohistochemical staining of clinical samples.

RESULTS

Using TCGA-HNSCC datasets, nine predictive genes for overall patient survival, rarely reported in previous similar studies, were screened. AREG and CES1 were identified as prognostic risk factors. CSTA, FDCSP, JCHAIN, IFFO2, PGLYRP4, SPOCK2 and SPINK6 were identified as prognostic factors. Collectively, all genes formed a prognostic risk signature model for oxidative stress in HNSCC, which were validated in GSE41613, GSE103322 and PRJEB23709 datasets. Immunohistochemical staining of SPINK6 in nasopharyngeal cancer samples validated the gene panel. Subsequent analysis indicated that subgroups of the oxidative stress prognostic signature played important roles during cellular communication, the immune microenvironment, the differential activation of transcription factors, oxidative stress and immunotherapeutic responses.

CONCLUSIONS

The risk model might predict HNSCC prognosis and immunotherapeutic responses.

A novel autophagy-related subtypes to distinguish immune phenotypes and predict immunotherapy response in head and neck squamous cell carcinoma

Both the absence of autophagy and excessive autophagy is double-edged sword in tumorigenesis. Due to the specificity of autophagy, its role in head and neck squamous cell carcinoma (HNSCC) is still unclear. In this study, we established five autophagy-related patterns in 1165 HNSCC patients with distinct cellular and molecular characteristics. Additionally, we developed a new scoring system (ATPscore) based on the differentially expressed genes (DEGs) among these five patterns, to represent the individual autophagy regulation pattern. ATPscore was shown to be significantly correlated with tumor immune microenvironment (TIME) infiltration, immune phenotypes, molecular subtypes, and genetic variations. We further found that ATPscore was both an independent prognostic factor and a potent predictor of clinical response to immune-checkpoint inhibitors (ICIs) based immunotherapy. We further verified the value of key gene SRPX in ATPscore in HNSCC cell lines with the in-depth research of ATPscore and found that it is closely related to immune subtypes, molecular subtypes, and immune activation-related markers. Our research could help us to understand the underlying mechanisms of tumor immunity and provide a solid foundation for combination of autophagy-targeted therapies with immunotherapies for clinical application in HNSCC.