Identification of Dihydrolipoamide Dehydrogenase as Potential Target of Vemurafenib-Resistant Melanoma Cells

The prognostic implications of cuproptosis-related gene signature and the potential of PPIC as a promising biomarker in cutaneous melanoma

Cutaneous melanoma is the most lethal of all skin tumors. Recently, cuproptosis, a novel form of cell death linked to oxidative phosphorylation, has emerged as an important factor. However, the precise role of cuproptosis in melanoma remains unclear. Our research explored the potential links between cuproptosis-related genes, prognosis, immune microenvironments, and melanoma treatments. Significantly, cuproptosis regulators showed remarkable differences between melanoma and normal tissues, establishing their relevance to melanoma. The newly developed cuproptosis-related gene signature (CGS) demonstrated a robust ability to predict overall survival (OS) in melanoma. We constructed a novel nomogram that combined clinical features with CGS to improve predictive accuracy. In addition, the study revealed correlations between CGS and immune cell populations, including CD8+T cells, Tfh cells, B cells, and myeloid-derived suppressor cells. Within the CGS, Peptidylprolyl isomerase C (PPIC) emerged as the most strongly associated with poor prognosis and drug resistance in melanoma. PPIC was identified as a promoter of melanoma progression, enhancing cell invasiveness while concurrently suppressing CD8+T cell activation. This comprehensive study not only elucidated the intricate connections between CGS, melanoma prognosis, immune microenvironment, and drug resistance but also provided compelling evidence supporting PPIC as a promising biomarker for predicting OS in melanoma treatment.

Mendelian Randomization Study Reveals a Predicted Relationship between Sensorineural Hearing Loss and Mitochondrial Proteins

BACKGROUND

Mitochondrial proteins assume a pivotal role in the onset and progression of diverse diseases. Nonetheless, the causal interconnections with sensorineural hearing loss (SNHL) demand meticulous exploration. Mendelian randomization analysis is a method used in observational epidemiological studies to predict the relationship between exposure factors and outcomes using genetic variants as instrumental variables. In this study, we applied this analytical approach to two distinct samples to predict the causal impact of mitochondrial proteins on SNHL.

METHODS

Two-sample Mendelian randomization analyses were executed to scrutinize the predicted associations between 63 mitochondrial proteins (nuclear-encoded) and SNHL, utilizing summary statistics derived from genome-wide association studies. Assessments of pleiotropy and heterogeneity were carried out to gauge the robustness of the obtained findings.

RESULTS

Four mitochondrial proteins exhibited a suggestive causal relationship with the susceptibility to SNHL. Dihydrolipoamide dehydrogenase (DLD; OR = 0.9706, 95% CI = 0.9382-0.9953, p = 0.0230) was linked to a diminished risk of SNHL. Conversely, elevated levels of mitochondrial ribosomal protein L34 (MRPL34; OR = 1.0458, 95% CI = 1.0029-1.0906, p = 0.0362), single-pass membrane protein with aspartate-rich tail 1 (SMDT1; OR = 1.0619, 95% CI = 1.0142-1.1119, p = 0.0104), and superoxide dismutase 2 (SOD2; OR = 1.0323, 95% CI = 1.0020-1.0634, p = 0.0364) were associated with an elevated risk of SNHL.

CONCLUSION

This research utilized Mendelian randomization analysis to predict the relationship between mitochondrial proteins and SNHL. It provides a potential viewpoint on the etiology and diagnosis.

DLD is a potential therapeutic target for COVID-19 infection in diffuse large B-cell lymphoma patients

Since the discovery of copper induces cell death(cuprotosis) in 2022, it has been one of the biggest research hotspots. cuprotosis related genes (CRGs) has been demonstrated to be a potential therapeutic target for cancer, however, the molecular mechanism of CRGs in coronavirus disease 2019 (COVID-19) infected in DLBCL patients has not been reported yet. Therefore, our research objective is first to elucidate the mechanism and role of CRGs in COVID-19. Secondly, we conducted univariate and multivariate analysis and machine learning to screen for CRGs with common expression differences in COVID-19 and DLBCL. Finally, the functional role and immune mechanism of genes in DLBCL were confirmed through cell experiments and immune analysis. The research results show that CRGs play an important role in the occurrence and development of COVID-19. Univariate analysis and machine learning confirm that dihydrolipoamide dehydrogenase (DLD) is the common key gene of COVID-19 and DLBCL. Inhibiting the expression of DLD can significantly inhibit the cycle progression and promote cell apoptosis of DLBCL cells and can target positive regulation of Lysine-specific demethylase 1 (LSD1, also known as KDM1A) to inhibit the proliferation of DLBCL cells and promote cell apoptosis. The immune analysis results show that high-expression of DLD may reduce T cell-mediated anti-tumor immunity by regulating immune infiltration of CD8 + T cells and positively regulating immune checkpoints LAG3 and CD276. Reducing the expression of DLD can effectively enhance T cell-mediated anti-tumor immunity, thereby clearing cancer cells and preventing cancer growth. In conclusion, DLD may be a potential therapeutic target for COVID-19 infection in DLBCL patients. Our research provides a theoretical basis for improving the clinical treatment of COVID-19 infection in DLBCL.

Dihydrolipoamide dehydrogenase (DLD) is a novel molecular target of bortezomib

Proteasome inhibitors (PIs), such as bortezomib and calfizomib, were backbone agents in the treatment of multiple myeloma (MM). In this study, we investigated bortezomib interactors in MM cells and identified dihydrolipoamide dehydrogenase (DLD) as a molecular target of bortezomib. DLD catalyzes the oxidation of dihydrolipoamide to form lipoamide, a reaction that also generates NADH. Our data showed that bortezomib bound to DLD and inhibited DLD's enzymatic function in MM cells. DLD knocked down MM cells (DLD-KD) had decreased levels of NADH. Reduced NADH suppressed assembly of proteasome complex in cells. As a result, DLD-KD MM cells had decreased basal-level proteasome activity and were more sensitive to bortezomib. Since PIs were used in many anti-MM regimens in clinics, we found that high expression of DLD correlated with inferior prognosis of MM. Considering the regulatory role of DLD in proteasome assembly, we evaluated DLD targeting therapy in MM cells. DLD inhibitor CPI-613 showed a synergistic anti-MM effect with bortezomib in vitro and in vivo. Overall, our findings elucidated DLD as an alternative molecular target of bortezomib in MM. DLD-targeting might increase MM sensitivity to PIs.

Novel cuproptosis-related prognostic gene profiles in preeclampsia

BACKGROUND

Preeclampsia (PE) is a pregnancy-specific disorder with complex pathogenesis. Cuproptosis is a novel identified form of programmed cell death, however, the link between cuproptosis and clinical outcomes in PE is still not fully understood. In this study, we searched for cuproptosis-related genes (CRGs) in the placental tissues of normal and PE patients to clarify the importance of cuproptosis in the development of PE and provide potential predictive indicators for the occurrence of PE.

METHODS

Using RNA sequencing data in the GEO database, we conducted functional enrichment analysis of Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Set Enrichment Analysis (GSEA), supported by linear regression model and operating characteristic curve (ROC) curve analysis, and summarized the role of CRGs in preeclampsia.

RESULTS

A total of 2831 differentially expressed genes related to PE were screened through multiple database analyses. After further intersection with 19 reported CRGs, 5 CRGs have been closely associated with the pathogenesis of PE, including NFE2L2, PDHA1, PDHB, DLD and GLS. NFE2L2 was identified as a key central gene. Pearson correlation analysis showed that CRGs could be related to several maternal and fetal outcome factors, including the highest pregnancy blood pressure, placenta weight, umbilical blood flow pulsatility index (PI), and neonatal weight. Linear regression equation revealed that the expression of NFE2L2 is negatively correlated with the highest pregnancy blood pressure and umbilical blood flow PI but positively correlated with placental weight and neonatal weight. QRT-PCR showed that the expression of these CRGs was significantly lower in placental tissues.

CONCLUSIONS

This cuproptosis pattern may be a potential prognostic factor in patients with PE and could provide new insights into disease progression.

Alpha-2-Macroglobulin Is a Novel Anticancer Agent

INTRODUCTION

Melanoma is the most aggressive skin cancer, with an increasing occurrence. Despite the recent important improvements due to novel immunotherapy approaches, when late diagnosed, melanoma prognosis is poor due to the metastatic progression and drug-resistance onset. Therefore, there is an urgent need to identify additional therapeutic targets. Melanoma invasive behavior is related to the activity of metalloproteases, able to degrade extracellular matrix leading to tumor dissemination. A recent study suggested that the most potent proteases inhibitor alpha-2-macroglobulin (A2MG) from plasma of hibernating fishes exerts potent antiproliferative effects. Our previous studies showed a significant reduction of A2MG in sera from mice/human melanoma models.

METHODS

Gene and protein expression studies have been performed by using platforms and databases available online containing expression data from thousands of patients and healthy controls.

RESULTS

We carried out an extensive bioinformatics analysis to evaluate the A2MG gene/protein expression on a large cohort of patients affected by many different cancer types, compared to healthy control subjects, and we found a highly significant difference of A2MG expression in 20 out of 31 cancer types (including melanoma) compared to healthy controls. Similar results were also confirmed at the proteomic level using another platform available online. Further, we found that higher A2MG expression is significantly related to overall survival in different cancers including melanoma.

CONCLUSION

Our results strongly suggest A2MG as a novel molecular target in melanoma therapy, as well as in other cancer types.

BRAF Mutations in Melanoma: Biological Aspects, Therapeutic Implications, and Circulating Biomarkers

Melanoma is an aggressive form of skin cancer resulting from the malignant transformation of melanocytes. Recent therapeutic approaches, including targeted therapy and immunotherapy, have improved the prognosis and outcome of melanoma patients. BRAF is one of the most frequently mutated oncogenes recognised in melanoma. The most frequent oncogenic BRAF mutations consist of a single point mutation at codon 600 (mostly V600E) that leads to constitutive activation of the BRAF/MEK/ERK (MAPK) signalling pathway. Therefore, mutated BRAF has become a useful target for molecular therapy and the use of BRAF kinase inhibitors has shown promising results. However, several resistance mechanisms invariably develop leading to therapeutic failure. The aim of this manuscript is to review the role of BRAF mutational status in the pathogenesis of melanoma and its impact on differentiation and inflammation. Moreover, this review focuses on the mechanisms responsible for resistance to targeted therapies in BRAF-mutated melanoma and provides an overview of circulating biomarkers including circulating tumour cells, circulating tumour DNA, and non-coding RNAs.