Novel Insights into PARK7 (DJ-1), a Potential Anti-Cancer Therapeutic Target, and Implications for Cancer Progression

Development of Inhibitors, Probes, and PROTAC Provides a Complete Toolbox to Study PARK7 in the Living Cell

The integration of diverse chemical tools like small-molecule inhibitors, activity-based probes (ABPs), and proteolysis targeting chimeras (PROTACs) advances clinical drug discovery and facilitates the exploration of various biological facets of targeted proteins. Here, we report the development of such a chemical toolbox for the human Parkinson disease protein 7 (PARK7/DJ-1) implicated in Parkinson's disease and cancers. By combining structure-guided design, miniaturized library synthesis, and high-throughput screening, we identified two potent compounds, JYQ-164 and JYQ-173, inhibiting PARK7 in vitro and in cells by covalently and selectively targeting its critical residue, Cys106. Leveraging JYQ-173, we further developed a cell-permeable Bodipy probe, JYQ-196, for covalent labeling of PARK7 in living cells and a first-in-class PARK7 degrader JYQ-194 that selectively induces its proteasomal degradation in human cells. Our study provides a valuable toolbox to enhance the understanding of PARK7 biology in cellular contexts and opens new opportunities for therapeutic interventions.

Practical Three-Component Regioselective Synthesis of Drug-Like 3-Aryl(or heteroaryl)-5,6-dihydrobenzo[h]cinnolines as Potential Non-Covalent Multi-Targeting Inhibitors To Combat Neurodegenerative Diseases

Neurodegenerative diseases (NDs) are one of the prominent health challenges facing contemporary society, and many efforts have been made to overcome and (or) control it. In this research paper, we described a practical one-pot two-step three-component reaction between 3,4-dihydronaphthalen-1(2H)-one (1), aryl(or heteroaryl)glyoxal monohydrates (2a-h), and hydrazine monohydrate (NH2NH2•H2O) for the regioselective preparation of some 3-aryl(or heteroaryl)-5,6-dihydrobenzo[h]cinnoline derivatives (3a-h). After synthesis and characterization of the mentioned cinnolines (3a-h), the in silico multi-targeting inhibitory properties of these heterocyclic scaffolds have been investigated upon various Homo sapiens-type enzymes, including hMAO-A, hMAO-B, hAChE, hBChE, hBACE-1, hBACE-2, hNQO-1, hNQO-2, hnNOS, hiNOS, hPARP-1, hPARP-2, hLRRK-2(G2019S), hGSK-3β, hp38α MAPK, hJNK-3, hOGA, hNMDA receptor, hnSMase-2, hIDO-1, hCOMT, hLIMK-1, hLIMK-2, hRIPK-1, hUCH-L1, hPARK-7, and hDHODH, which have confirmed their functions and roles in the neurodegenerative diseases (NDs), based on molecular docking studies, and the obtained results were compared with a wide range of approved drugs and well-known (with IC50, EC50, etc.) compounds. In addition, in silico ADMET prediction analysis was performed to examine the prospective drug properties of the synthesized heterocyclic compounds (3a-h). The obtained results from the molecular docking studies and ADMET-related data demonstrated that these series of 3-aryl(or heteroaryl)-5,6-dihydrobenzo[h]cinnolines (3a-h), especially hit ones, can really be turned into the potent core of new drugs for the treatment of neurodegenerative diseases (NDs), and/or due to the having some reactionable locations, they are able to have further organic reactions (such as cross-coupling reactions), and expansion of these compounds (for example, with using other types of aryl(or heteroaryl)glyoxal monohydrates) makes a new avenue for designing novel and efficient drugs for this purpose.

Clinical value of serum DJ-1 in lung adenocarcinoma

Objective

DJ-1 is an oncoprotein secreted by cancer cells. However, the physiological and pathological significance of DJ-1 secretion is not clearly understood. This study investigated the clinical value of serum DJ-1 in lung adenocarcinoma (LUAD).

Methods

The study involved 224 LUAD patients, 110 patients with benign pulmonary disease and 100 healthy controls from the First Affiliated Hospital of Nanjing Medical University. We detected the expression of DJ-1 in lung cell lines in vitro. Meanwhile, serum concentrations of DJ-1, carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), and cytokeratin 19 fragment (CYFRA21-1) were measured. The diagnostic performance of LUAD was obtained using receiver operating characteristic (ROC) curves. Kaplan-Meier, univariate and multivariate Cox regression analyses were performed for progression-free survival (PFS).

Results

DJ-1 was highly expressed in LUAD cell lines. Serum DJ-1 levels were significantly higher in the LUAD group compared to the benign pulmonary disease group (5.04 vs. 3.66 ng/mL, P < 0.001) and healthy controls (5.04 vs. 3.51 ng/mL, P < 0.001). DJ-1 levels were associated with gender (P = 0.002), smoking history (P = 0.042) and lymph node metastasis (P = 0.040). ROC curve analysis of DJ-1 revealed an area under the curve (AUC) of 0.758 (95% CI [0.714-0.803], P < 0.001) with a sensitivity of 63.8% and specificity of 78.6% at a cutoff value of 4.62 ng/mL for the detection of LUAD. Univariate and multivariate analyses confirmed that the preoperative serum DJ-1 level, tumor stage and smoking history were independent prognostic factors of PFS.

Conclusion

Our study is the first to explore the clinical value of serum DJ-1 in LUAD comprehensively. Serum DJ-1 could be a potential diagnostic and prognostic biomarker for LUAD.

Elucidating the susceptibility to breast cancer: an in-depth proteomic and transcriptomic investigation into novel potential plasma protein biomarkers

Objectives: This study aimed to identify plasma proteins that are associated with and causative of breast cancer through Proteome and Transcriptome-wide association studies combining Mendelian Randomization. Methods: Utilizing high-throughput datasets, we designed a two-phase analytical framework aimed at identifying novel plasma proteins that are both associated with and causative of breast cancer. Initially, we conducted Proteome/Transcriptome-wide association studies (P/TWAS) to identify plasma proteins with significant associations. Subsequently, Mendelian Randomization was employed to ascertain the causation. The validity and robustness of our findings were further reinforced through external validation and various sensitivity analyses, including Bayesian colocalization, Steiger filtering, heterogeneity and pleiotropy. Additionally, we performed functional enrichment analysis of the identified proteins to better understand their roles in breast cancer and to assess their potential as druggable targets. Results: We identified 5 plasma proteins demonstrating strong associations and causative links with breast cancer. Specifically, PEX14 (OR = 1.201, p = 0.016) and CTSF (OR = 1.114, p < 0.001) both displayed positive and causal association with breast cancer. In contrast, SNUPN (OR = 0.905, p < 0.001), CSK (OR = 0.962, p = 0.038), and PARK7 (OR = 0.954, p < 0.001) were negatively associated with the disease. For the ER-positive subtype, 3 plasma proteins were identified, with CSK and CTSF exhibiting consistent trends, while GDI2 (OR = 0.920, p < 0.001) was distinct to this subtype. In ER-negative subtype, PEX14 (OR = 1.645, p < 0.001) stood out as the sole protein, even showing a stronger causal effect compared to breast cancer. These associations were robustly supported by colocalization and sensitivity analyses. Conclusion: Integrating multiple data dimensions, our study successfully pinpointed plasma proteins significantly associated with and causative of breast cancer, offering valuable insights for future research and potential new biomarkers and therapeutic targets.

Uncovering potential diagnostic and pathophysiological roles of α-synuclein and DJ-1 in melanoma

BACKGROUND

Melanoma, the most lethal skin cancer type, occurs more frequently in Parkinson's disease (PD), and PD is more frequent in melanoma patients, suggesting disease mechanisms overlap. α-synuclein, a protein that accumulates in PD brain, and the oncogene DJ-1, which is associated with PD autosomal recessive forms, are both elevated in melanoma cells. Whether this indicates melanoma progression or constitutes a protective response remains unclear. We hereby investigated the molecular mechanisms through which α-synuclein and DJ-1 interact, suggesting novel biomarkers and targets in melanoma.

METHODS

The Cancer Genome Atlas (TCGA) expression profiles derived from UCSC Xena were used to obtain α-synuclein and DJ-1 expression and correlated with survival in skin cutaneous melanoma (SKCM). Immunohistochemistry determined the expression in metastatic melanoma lymph nodes. Protein-protein interactions (PPIs) and molecular docking assessed protein binding and affinity with chemotherapeutic drugs. Further validation was performed using in vitro cellular models and ELISA immunoassays.

RESULTS

α-synuclein and DJ-1 were upregulated in primary and metastatic SKCM. Aggregated α-synuclein was selectively detected in metastatic melanoma lymph nodes. α-synuclein overexpression in SK-MEL-28 cells induced the expression of DJ-1, supporting PPI and a positive correlation in melanoma patients. Molecular docking revealed a stable protein complex, with differential binding to chemotherapy drugs such as temozolomide, dacarbazine, and doxorubicin. Parallel reduction of both proteins in temozolomide-treated SK-MEL-28 spheroids suggests drug binding may affect protein interaction and/or stability.

CONCLUSION

α-synuclein, together with DJ-1, may play a role in melanoma progression and chemosensitivity, constituting novel targets for therapeutic intervention, and possible biomarkers for melanoma.

Unraveling the role of miRNAs in the diagnosis, progression, and therapeutic intervention of Parkinson's disease

Parkinson's disease (PD) is a debilitating neurological disorder characterized by the impairment of the motor system, resulting in symptoms such as resting tremor, cogwheel rigidity, bradykinesia, difficulty with gait, and postural instability. The occurrence of striatal dopamine insufficiency can be attributed to a notable decline in dopaminergic neurons inside the substantia nigra pars compacta. Additionally, the development of Lewy bodies serves as a pathological hallmark of PD. While current therapy approaches for PD aim to preserve dopaminergic neurons or replenish dopamine levels in the brain, it is important to acknowledge that achieving complete remission of the condition remains elusive. MicroRNAs (miRNAs, miR) are a class of small, non-coding ribonucleic acids involved in regulating gene expression at the post-transcriptional level. The miRNAs play a crucial part in the underlying pathogenic mechanisms of several neurodegenerative illnesses, including PD. The aim of this review is to explore the role of miRNAs in regulating genes associated with the onset and progression of PD, investigate the potential of miRNAs as a diagnostic tool, assess the effectiveness of targeting specific miRNAs as an alternative therapeutic strategy to impede disease advancement, and discuss the utilization of newly developed nanoparticles for delivering miRNAs as neurodegenerative therapies.

DJ-1: A Potential Biomarker Related to Prognosis, Chemoresistance, and Expression of Microenvironmental Chemokine in HR-Positive Breast Cancer

DJ-1 is significantly elevated in various malignancies. However, the clinical significance of DJ-1 in hormone receptor (HR)-positive (HR+) breast cancer remains unclear. We evaluated DJ-1 expression in different databases and validated in vitro assay by RT-PCR and western blot among HR+ breast cancer. The correlations between DJ-1 level and tumor-immune were calculated. Mutational landscape, enriched signaling pathways, and drug sensitivity analyses were also assessed between DJ-1 high and low-expression groups. DJ-1 was upregulated in HR+ breast cancer, and high DJ-1 expression was significantly linked with poor prognosis. DJ-1 was correlated with the expression and function of different immune cells. The low DJ-1 group showed sensitivity to paclitaxel and docetaxel, while the high-expression group showed sensitivity to doxorubicin. CTLA4 and PD-L1 were more sensitive in high-DJ-1 group. It is involved in a range of pathways and might behave as a novel biomarker of prognostic value for the immune environment and drug sensitivity in HR+ breast cancer.

Single-cell dissection reveals the role of aggrephagy patterns in tumor microenvironment components aiding predicting prognosis and immunotherapy on lung adenocarcinoma

BACKGROUND

Lung adenocarcinoma (LUAD) is one of the leading malignant cancers. Aggrephagy plays a critical role in key genetic events for various cancers; yet, how aggrephagy functions within the tumor microenvironment (TME) in LUAD remains to be elucidated.

METHODS

In this study, by sequential non-negative matrix factorization (NMF) algorithm, pseudotime analysis, cell-cell interaction analysis, and SCENIC analysis, we have shown that aggrephagy genes demonstrated various patterns among different cell types in LUAD TME. LUAD and Immunotherapy cohorts from public repository were used to determine the prognosis and immune response of aggrephagy TME subtypes. The aggrephagy-deprived prognostic score (ADPS) was quantified based on machine learning algorithms.

RESULTS

The cancer-associated fibroblasts (CAFs), tumor-associated macrophages (TAMs), and CD8+ T cells have various aggrephagy patterns, which enhance the intensity of intercellular communication and transcription factor activation. Furthermore, based on the signatures of the newly defined aggrephagy cell subtypes and expression profiles of large cohorts in LUAD patients, we determine that DYNC1I2+CAF-C1, DYNLL1+CAF-C2, PARK7+CAF-C3, VIM+Mac-C1, PARK7+Mac-C2, VIM+CD8+T_cells-C1, UBA52+CD8+T_cells-C2, TUBA4A+CD8+T_ cells-C3, and TUBA1A+CD8+T_cells-C4 are crucial prognostic factors for LUAD patients. The developed ADPS could predict survival outcomes and immunotherapeutic response across ten cohorts (n = 1838), and patients with low ADPS owned a better prognosis, lower genomic alterations, and are more sensitive to immunotherapy. Meanwhile, based on PRISM, CTRP, and CMAP databases, PLK inhibitor BI-2536, may be a potential agent for patients with high ADPS.

CONCLUSIONS

Taken together, our novel and systematic single-cell analysis has revealed the unique role of aggrephagy in remodeling the TME of LUAD. As a newly demonstrated biomarker, the ADPS facilitates the clinical management and individualized treatment of LUAD.

Development and Perspectives: Multifunctional Nucleic Acid Nanomedicines for Treatment of Gynecological Cancers

Gynecological malignancies are a significant cause of morbidity and mortality across the globe. Due to delayed presentation, gynecological cancer patients are often referred late in the disease's course, resulting in poor outcomes. A considerable number of patients ultimately succumb to chemotherapy-resistant disease, which reoccurs at advanced stages despite treatment interventions. Although efforts have been devoted to developing therapies that demonstrate reduced resistance to chemotherapy and enhanced toxicity profiles, current clinical outcomes remain unsatisfactory due to treatment resistance and unfavorable off-target effects. Consequently, innovative biological and nanotherapeutic approaches are imperative to strengthen and optimize the therapeutic arsenal for gynecological cancers. Advancements in nanotechnology-based therapies for gynecological malignancies offer significant advantages, including reduced toxicity, expanded drug circulation, and optimized therapeutic dosing, ultimately leading to enhanced treatment effectiveness. Recent advances in nucleic acid therapeutics using microRNA, small interfering RNA, and messenger RNA provide novel approaches for cancer therapeutics. Effective single-agent and combinatorial nucleic acid therapeutics for gynecological malignancies have the potential to transform cancer treatment by giving safer, more tailored approaches than conventional therapies. This review highlights current preclinical studies that effectively exploit these approaches for the treatment of gynecological malignant tumors and malignant ascites.

Importance of DJ-1 in autophagy regulation and disease

Autophagy is a highly conserved biological process that has evolved across evolution. It can be activated by various external stimuli including oxidative stress, amino acid starvation, infection, and hypoxia. Autophagy is the primary mechanism for preserving cellular homeostasis and is implicated in the regulation of metabolism, cell differentiation, tolerance to starvation conditions, and resistance to aging. As a multifunctional protein, DJ-1 is commonly expressed in vivo and is associated with a variety of biological processes. Its most widely studied role is its function as an oxidative stress sensor that inhibits the production of excessive reactive oxygen species (ROS) in the mitochondria and subsequently the cellular damage caused by oxidative stress. In recent years, many studies have identified DJ-1 as another important factor regulating autophagy; it regulates autophagy in various ways, most commonly by regulating the oxidative stress response. In particular, DJ-1-regulated autophagy is involved in cancer progression and plays a key role in alleviating neurodegenerative diseases(NDS) and defective reperfusion diseases. It could serve as a potential target for the regulation of autophagy and participate in disease treatment as a meaningful modality. Therefore, exploring DJ-1-regulated autophagy could provide new avenues for future disease treatment.

Identification of target proteins for breast cancer genetic risk loci and blood risk biomarkers in a large study by integrating genomic and proteomic data

Genome-wide association studies (GWAS) have identified around 200 loci associated with breast cancer risk. However, protein targets for these loci remain largely unknown. Identifying protein targets and biomarkers can improve the understanding of cancer biology and etiology and identify high-risk individuals for cancer prevention. In this study, we investigated genetically predicted levels of 1142 circulating proteins with breast cancer risk in 133 384 cases and 113 789 controls of European ancestry included in the Breast Cancer Association Consortium (BCAC). We identified 22 blood protein biomarkers associated with the risk of overall breast cancer at a false discovery rate (FDR) <0.05, including nine proteins encoded by genes located at least 500 kb away from previously reported risk variants for breast cancer. Analyses focusing on 124 encoding genes located at GWAS-identified breast cancer risk loci found 20 proteins associated with overall breast cancer risk and one protein associated with triple-negative breast cancer risk at FDR <0.05. Adjustment for the GWAS-identified risk variants significantly attenuated the association for 13 of these proteins, suggesting that these proteins may be the targets of these GWAS-identified risk loci. The identified proteins are involved in various biological processes, including glutathione conjugation, STAT5 signaling and NF-κB signaling pathways. Our study identified novel protein targets and risk biomarkers for breast cancer risk.

Phthalates impact on the epigenetic factors contributed specifically by the father at fertilization

BACKGROUND

Preconception exposure to phthalates such as the anti-androgenic dibutyl-phthalate (DBP) impacts both male and female reproduction, yet how this occurs largely remains unknown. Previously we defined a series of RNAs expressly provided by sperm at fertilization and separately, and in parallel, those that responded to high DBP exposure. Utilizing both populations of RNAs, we now begin to unravel the impact of high-DBP exposure on those RNAs specifically delivered by the father.

RESULTS

Enrichment of RNAs altered by DBP exposure within the Molecular Signature Database highlighted cellular stress, cell cycle, apoptosis, DNA damage response, and gene regulation pathways. Overlap within each of these five pathways identified those RNAs that were specifically (≥ fivefold enriched) or primarily (≥ twofold enriched) provided as part of the paternal contribution compared to the oocyte at fertilization. Key RNAs consistently altered by DBP, including CAMTA2 and PSME4, were delivered by sperm reflective of these pathways. The majority (64/103) of overlapping enriched gene sets were related to gene regulation. Many of these RNAs (45 RNAs) corresponded to key interconnected CRREWs (Chromatin remodeler cofactors, RNA interactors, Readers, Erasers, and Writers). Modeling suggests that CUL2, PHF10, and SMARCC1 may coordinate and mechanistically modulate the phthalate response.

CONCLUSIONS

Mediated through a CRREW regulatory network, the cell responded to exposure presenting stressed-induced changes in the cell cycle-DNA damage-apoptosis. Interestingly, the majority of these DBP-responsive epigenetic mediators' direct acetylation or deacetylation, impacting the sperm's cargo delivered at fertilization and that of the embryo.

Ciclopirox Olamine Induces Proliferation Inhibition and Protective Autophagy in Hepatocellular Carcinoma

Hepatocellular carcinoma is one of the most common fatal malignancies worldwide. Thus far, the hepatocellular carcinoma prognosis has been bleak due to deficiencies in the identification and diagnosis of early hepatocellular carcinoma. Ciclopirox olamine (CPX) is a synthetic antifungal agent and has been considered as an anti-cancer candidate drug recently, though the detailed mechanisms related to its anti-cancer effect in hepatocellular carcinoma have not yet been revealed. Here, we found that CPX could inhibit proliferation in HCC cells but not in intrahepatic cholangiocarcinoma cells by arresting the cell cycle. Moreover, the anti-cancer effects of CPX in HCC cells were also attributed to CPX-triggered ROS accumulation and DJ-1 downregulation. Additionally, CPX could promote complete autophagic flux, which alleviated the anti-cancer effect of CPX in HCC cells, whereas the ROS scavenger (NAC) would attenuate CPX-induced protective autophagy. Interestingly, CPX could also induce glycogen clustering in HCC cells. Altogether, this study provides a new insight into the detailed molecular mechanisms of CPX as an anti-cancer therapy and a strategy for treating hepatocellular carcinoma.

Investigating the Function of Human Jumping Translocation Breakpoint Protein (hJTB) and Its Interacting Partners through In-Solution Proteomics of MCF7 Cells

Human jumping translocation breakpoint (hJTB) gene is located on chromosome 1q21 and is involved in unbalanced translocation in many types of cancer. JTB protein is ubiquitously present in normal cells but it is found to be overexpressed or downregulated in various types of cancer cells, where this protein and its isoforms promote mitochondrial dysfunction, resistance to apoptosis, genomic instability, proliferation, invasion and metastasis. Hence, JTB could be a tumor biomarker for different types of cancer, such as breast cancer (BC), and could be used as a drug target for therapy. However, the functions of the protein or the pathways through which it increases cell proliferation and invasiveness of cancer cells are not well-known. Therefore, we aim to investigate the functions of JTB by using in-solution digestion-based cellular proteomics of control and upregulated and downregulated JTB protein in MCF7 breast cancer cell line, taking account that in-solution digestion-based proteomics experiments are complementary to the initial in-gel based ones. Proteomics analysis allows investigation of protein dysregulation patterns that indicate the function of the protein and its interacting partners, as well as the pathways and biological processes through which it functions. We concluded that JTB dysregulation increases the epithelial-mesenchymal transition (EMT) potential and cell proliferation, harnessing cytoskeleton organization, apical junctional complex, metabolic reprogramming, and cellular proteostasis. Deregulated JTB expression was found to be associated with several proteins involved in mitochondrial organization and function, oxidative stress (OS), apoptosis, and interferon alpha and gamma signaling. Consistent and complementary to our previous results emerged by using in-gel based proteomics of transfected MCF7 cells, JTB-related proteins that are overexpressed in this experiment suggest the development of a more aggressive phenotype and behavior for this luminal type A non-invasive/poor-invasive human BC cell line that does not usually migrate or invade compared with the highly metastatic MDA-MB-231 cells. This more aggressive phenotype of MCF7 cells related to JTB dysregulation and detected by both in-gel and in-solution proteomics could be promoted by synergistic upregulation of EMT, Mitotic spindle and Fatty acid metabolism pathways. However, in both JTB dysregulated conditions, several downregulated JTB-interacting proteins predominantly sustain antitumor activities, attenuating some of the aggressive phenotypical and behavioral traits promoted by the overexpressed JTB-related partners.

DJ-1 promotes osteosarcoma progression through activating CDK4/RB/E2F1 signaling pathway

Osteosarcoma (OS) is a primary malignant tumor of the bone characterized by poor prognosis due to chemotherapy resistance and high recurrence rates. DJ-1 (PARK7) is known as an oncogene and its abnormal expression is related to the poor prognosis of various types of malignant tumors. It was found in this study that upregulated expression of DJ-1 was closely correlated with the prognosis of OS patients by promoting the proliferation, migration and chemotherapy resistance of OS cells in vitro through regulating the activity of CDK4 but not through the oxidation mechanism or AKT pathway. The combination of DJ-1 and CDK4 promoted RB phosphorylation, leading to the dissociation of E2F1 into the nucleus to regulate the expression of cell cycle-related genes. The tumor xenograft mouse model demonstrated that DJ-1 knockout suppressed tumor growth in vivo. All these findings indicate that DJ-1 can affect the occurrence and progression of OS by regulating the CDK/RB/E2F1axis, suggesting a novel therapeutic opportunity for OS patients.

TrkC-mediated inhibition of DJ-1 degradation is essential for direct regulation of pathogenesis of hepatocellular carcinoma

None of the previous studies has systematically explored how upregulation of TrkC plays a central role in the pathogenesis of hepatocellular carcinoma (HCC) by regulating the underlying mechanisms that promote invasion and metastasis. In this report, we demonstrated the possible association between upregulation of TrkC and acquisition of cancer stem cells traits or chemoresistance in HCC. We show that upregulation of TrkC is closely associated with the survival and progression of HCC in vivo and in vitro. Most strikingly, activation of STAT3 by TrkC-mediated inhibition of DJ-1 degradation significantly enhances the efficacy of invasion and metastasis during the progression of HCC cells. Acquiring the traits of cancer stem cells (CSCs) by TrkC/DJ-1/STAT3 signaling pathway leads to the induction of chemoresistance via upregulation of ABC transporters and anti-apoptotic genes. Also, activating the epithelial-mesenchymal transition (EMT) program by inducing EMT-transcription factor (TF)s by TrkC/DJ-1/STAT3 signaling pathway is the direct cause of multiple tumor malignancies of HCC. Thus, understanding the mechanisms by which acquisition of anticancer drug resistance by TrkC-mediated inhibition of DJ-1 degradation can help enhance the efficacy of anticancer therapies.

Chemical Toolkit for PARK7: Potent, Selective, and High-Throughput

The multifunctional human Parkinson's disease protein 7 (PARK7/DJ1) is an attractive therapeutic target due to its link with early-onset Parkinson's disease, upregulation in various cancers, and contribution to chemoresistance. However, only a few compounds have been identified to bind PARK7 due to the lack of a dedicated chemical toolbox. We report the creation of such a toolbox and showcase the application of each of its components. The selective PARK7 submicromolar inhibitor with a cyanimide reactive group covalently modifies the active site Cys106. Installment of different dyes onto the inhibitor delivered two PARK7 probes. The Rhodamine110 probe provides a high-throughput screening compatible FP assay, showcased by screening a compound library (8000 molecules). The SulfoCy5-equipped probe is a valuable tool to assess the effect of PARK7 inhibitors in a cell lysate. Our work creates new possibilities to explore PARK7 function in a physiologically relevant setting and develop new and improved PARK7 inhibitors.

Irradiation induces DJ-1 secretion from esophageal squamous cell carcinoma cells to accelerate metastasis of bystander cells via a TGF-β1 positive feedback loop

Background

Radiation-induced bystander effect (RIBE) can promote tumor metastasis contributing to the failure of radiotherapy for esophageal squamous cell carcinoma (ESCC). Aberrant expression of DJ-1 has been identified in ESCC; however, the relationship between DJ-1 and RIBE in ESCC remains unknown.

Methods

We detected DJ-1 in the serum and cell supernatants by enzyme-linked immunosorbent assay (ELISA) and evaluated tumor metastasis by phenotypic experiments in vivo and in vitro. RNA-seq, mass spectrometry, western blot (WB), immunoprecipitation (IP), and dual-luciferase reporter assays were performed to explore the underlying mechanisms.

Results

DJ-1 was highly expressed in the serum of patients with ESCC receiving radiotherapy and was significantly overexpressed in the medium of ESCC cells receiving irradiation. DJ-1 promoted tumor metastasis via the TGF-β1 pathway. Mechanistic studies revealed that DJ-1 bound to HSC70 to promote Smad3 phosphorylation and nuclear aggregation in a protein-interaction manner, which activated the transcription of Thrombospondin-1 (TSP1). Subsequently, the activation of TGF-β1 by TSP1 re-promoted Smad3 phosphorylation and nuclear aggregation, constituting a positive feedback loop to strengthen the metastasis of ESCC cells, which was effectively blocked by LY2109761 and LSKL. Moreover, higher levels of serum DJ-1 in patients with ESCC were related to a poorer prognosis of radiotherapy.

Conclusions

Irradiation can induce ESCC cells secreting DJ-1. Secreted DJ-1 enters bystander cells to initiate activation of the TGF-β1 pathway via the DJ-1/HSC70/Smad3 signaling axis. The TSP1/TGF-β1/Smad3 positive feedback pathway constitutes the core pathway that promotes ESCC metastasis. DJ-1 is a useful biomarker for predicting the efficacy of radiotherapy and a potential therapeutic target for reversing RIBE in ESCC.

Graphical Abstract

Schematic diagram showing the underlying mechanism that irradiation-induced secretion of DJ-1 accelerates the metastasis of bystander ESCC cells.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-022-02471-6.

Oncoprotein DJ-1 interacts with mTOR complexes to effect transcription factor Hif1α-dependent expression of collagen I (α2) during renal fibrosis

Proximal tubular epithelial cells respond to transforming growth factor β (TGFβ) to synthesize collagen I (α2) during renal fibrosis. The oncoprotein DJ-1 has previously been shown to promote tumorigenesis and prevent apoptosis of dopaminergic neurons; however, its role in fibrosis signaling is unclear. Here, we show TGFβ-stimulation increased expression of DJ-1, which promoted noncanonical mTORC1 and mTORC2 activities. We show DJ-1 augmented the phosphorylation/activation of PKCβII, a direct substrate of mTORC2. In addition, coimmunoprecipitation experiments revealed association of DJ-1 with Raptor and Rictor, exclusive subunits of mTORC1 and mTORC2, respectively, as well as with mTOR kinase. Interestingly, siRNAs against DJ-1 blocked TGFβ-stimulated expression of collagen I (α2), while expression of DJ-1 increased expression of this protein. In addition, expression of dominant negative PKCβII and siRNAs against PKCβII significantly inhibited TGFβ-induced collagen I (α2) expression. In fact, constitutively active PKCβII abrogated the effect of siRNAs against DJ-1, suggesting a role of PKCβII downstream of this oncoprotein. Moreover, we demonstrate expression of collagen I (α2) stimulated by DJ-1 and its target PKCβII is dependent on the transcription factor hypoxia-inducible factor 1α (Hif1α). Finally, we show in the renal cortex of diabetic rats that increased TGFβ was associated with enhanced expression of DJ-1 and activation of mTOR and PKCβII, concomitant with increased Hif1α and collagen I (α2). Overall, we identified that DJ-1 affects TGFβ-induced expression of collagen I (α2) via an mTOR-, PKCβII-, and Hif1α-dependent mechanism to regulate renal fibrosis.

PARK7/DJ-1 as a Therapeutic Target in Gut-Brain Axis Diseases

It is increasingly known that Parkinson's (PD) and Alzheimer's (AD) diseases occur more frequently in patients with inflammatory gastrointestinal diseases including inflammatory bowel (IBD) or celiac disease, indicating a pathological link between them. Although epidemiological observations suggest the existence of the gut-brain axis (GBA) involving systemic inflammatory and neural pathways, little is known about the exact molecular mechanisms. Parkinson's disease 7 (PARK7/DJ-1) is a multifunctional protein whose protective role has been widely demonstrated in neurodegenerative diseases, including PD, AD, or ischemic stroke. Recent studies also revealed the importance of PARK7/DJ-1 in the maintenance of the gut microbiome and also in the regulation of intestinal inflammation. All these findings suggest that PARK7/DJ-1 may be a link and also a potential therapeutic target in gut and brain diseases. In this review, therefore, we discuss our current knowledge about PARK7/DJ-1 in the context of GBA diseases.

ROS generation attenuates the anti-cancer effect of CPX on cervical cancer cells by inducing autophagy and inhibiting glycophagy

Cervical cancer is one of the most common gynecological malignancies with poor prognosis due to constant chemoresistance and repeated relapse. Ciclopirox olamine (CPX), a synthetic antifungal agent, has recently been identified to be a promising anti-cancer candidate. However, the detailed mechanisms related to its anti-cancer effects remain unclear and need to be further elucidated. In this study, we found that CPX could induce proliferation inhibition in cervical cancer cells by targeting PARK7. Further results demonstrated that CPX could induce cytoprotective autophagy by downregulating the expression of PARK7 to activate PRKAA1 or by PARK7-independent accumulation of ROS to inhibit mTOR signaling. Meanwhile, CPX treatment increased the glycogen clustering and glycophagy in cervical cancer cells. The presence of N-acetyl-l-cysteine (NAC), a ROS scavenger, led to further clustering of glycogen in cells by reducing autophagy and enhancing glycophagy, which promoted CPX-induced inhibition of cervical cancer cell proliferation. Together, our study provides new insights into the molecular mechanisms of CPX in the anti-cancer therapy and opens new avenues for the glycophagy in cancer therapeutics.

•

CPX induces cytoprotective autophagy and inhibits proliferation of cervical cancer cells by targeting PARK7.

•

ROS generation attenuates the anticancer effect of CPX by inducing cytoprotective autophagy and inhibiting glycophagy.

•

ROS-triggered glycogen clustering and inactivation of YAP1 are involved in the anti-cancer effects of CPX.

Ciclopirox Olamine Exerts Tumor-Suppressor Effects via Topoisomerase II Alpha in Lung Adenocarcinoma

Background

Globally, lung cancer is one of the most malignant tumors, of which lung adenocarcinoma (LUAD) is the most common subtype, with a particularly poor prognosis. Ciclopirox olamine (CPX) is an antifungal drug and was recently identified as a potential antitumor agent. However, how CPX and its mechanism of action function during LUAD remain unclear.

Methods

The effects of CPX on cell proliferation, cell cycle, reactive oxygen species (ROS) levels, and apoptosis were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, colony formation, western blotting, flow cytometry assays, and immunohistochemistry. Global gene expression levels were compared between control and CPX-treated LUAD cells. A LUAD xenograft mouse model was used to evaluate the potential in vivo effects of CPX.

Results

We observed that CPX displayed strong antitumorigenic properties in LUAD cells, inhibited LUAD proliferation, induced ROS production, caused DNA damage, and activated the ATR-CHK1-P53 pathway. Topoisomerase II alpha (TOP2A) is overexpressed in LUAD and associated with a poor prognosis. By analyzing differentially expressed genes (DEGs), TOP2A was significantly down-regulated in CPX-treated LUAD cells. Furthermore, CPX treatment substantially inhibited in vivo LUAD xenograft growth without toxicity or side effects to the hematological system and internal organs.

Conclusions

Collectively, for the first time, we showed that CPX exerted tumor-suppressor effects in LUAD via TOP2A, suggesting CPX could potentially function as a promising chemotherapeutic for LUAD treatment.

Screening for the Key Proteins Associated with Rete Testis Invasion in Clinical Stage I Seminoma via Label-Free Quantitative Mass Spectrometry

Rete testis invasion (RTI) is an unfavourable prognostic factor for the risk of relapse in clinical stage I (CS I) seminoma patients. Notably, no evidence of difference in the proteome of RTI-positive vs. -negative CS I seminomas has been reported yet. Here, a quantitative proteomic approach was used to investigate RTI-associated proteins. 64 proteins were differentially expressed in RTI-positive compared to -negative CS I seminomas. Of them, 14-3-3γ, ezrin, filamin A, Parkinsonism-associated deglycase 7 (PARK7), vimentin and vinculin, were validated in CS I seminoma patient cohort. As shown by multivariate analysis controlling for clinical confounders, PARK7 and filamin A expression lowered the risk of RTI, while 14-3-3γ expression increased it. Therefore, we suggest that in real clinical biopsy specimens, the expression level of these proteins may reflect prognosis in CS I seminoma patients.

HOXA5 Is Recognized as a Prognostic-Related Biomarker and Promotes Glioma Progression Through Affecting Cell Cycle

Glioma is malignant tumor derives from glial cells in the central nervous system. High-grade glioma shows aggressive growth pattern, and conventional treatments, such as surgical removal and chemo-radiotherapy, archive limitation in the interference of this process. In this work, HOXA5, from the HOX family, was identified as a glioma cell proliferation-associated factor by investigating its feature in the TCGA and CGGA data set. High HOXA5 expression samples contain unfavorable clinical features of glioma, including IDH wild type, un-methylated MGMT status, non-codeletion 1p19q status, malignant molecular subtype. Survival analysis indicates that high HOXA5 expression samples are associated with worse clinical outcome. The CNVs and SNPs profile difference further confirmed the enrichment of glioma aggressive related biomarkers. In the meantime, the activation of DNA damage repair-related pathways and TP53-related pathways is also related to HOXA5 expression. In cell lines, U87MG and U251, by interfering HOXA5 expression significantly inhibit glioma progression and apoptosis, and cell cycle is arrested at the G2/M phase. Collectively, increased HOXA5 expression can promote glioma progression via affecting glioma cell proliferation.

Advances in Applying Computer-Aided Drug Design for Neurodegenerative Diseases

Neurodegenerative diseases (NDs) including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and Huntington's disease are incurable and affect millions of people worldwide. The development of treatments for this unmet clinical need is a major global research challenge. Computer-aided drug design (CADD) methods minimize the huge number of ligands that could be screened in biological assays, reducing the cost, time, and effort required to develop new drugs. In this review, we provide an introduction to CADD and examine the progress in applying CADD and other molecular docking studies to NDs. We provide an updated overview of potential therapeutic targets for various NDs and discuss some of the advantages and disadvantages of these tools.

Mitochondrial ATP-Dependent Proteases-Biological Function and Potential Anti-Cancer Targets

Cells must eliminate excess or damaged proteins to maintain protein homeostasis. To ensure protein homeostasis in the cytoplasm, cells rely on the ubiquitin-proteasome system and autophagy. In the mitochondria, protein homeostasis is regulated by mitochondria proteases, including four core ATP-dependent proteases, m-AAA, i-AAA, LonP, and ClpXP, located in the mitochondrial membrane and matrix. This review will discuss the function of mitochondrial proteases, with a focus on ClpXP as a novel therapeutic target for the treatment of malignancy. ClpXP maintains the integrity of the mitochondrial respiratory chain and regulates metabolism by degrading damaged and misfolded mitochondrial proteins. Inhibiting ClpXP genetically or chemically impairs oxidative phosphorylation and is toxic to malignant cells with high ClpXP expression. Likewise, hyperactivating the protease leads to increased degradation of ClpXP substrates and kills cancer cells. Thus, targeting ClpXP through inhibition or hyperactivation may be novel approaches for patients with malignancy.

The Role of Autophagy in Gastric Cancer Chemoresistance: Friend or Foe?

Gastric cancer is the third most common cause of cancer-related death worldwide. Drug resistance is the main inevitable and vital factor leading to a low 5-year survival rate for patients with gastric cancer. Autophagy, as a highly conserved homeostatic pathway, is mainly regulated by different proteins and non-coding RNAs (ncRNAs) and plays dual roles in drug resistance of gastric cancer. Thus, targeting key regulatory nodes in the process of autophagy by small molecule inhibitors or activators has become one of the most promising strategies for the treatment of gastric cancer in recent years. In this review, we provide a systematic summary focusing on the relationship between autophagy and chemotherapy resistance in gastric cancer. We comprehensively discuss the roles and molecular mechanisms of multiple proteins and the emerging ncRNAs including miRNAs and lncRNAs in the regulation of autophagy pathways and gastric cancer chemoresistance. We also summarize the regulatory effects of autophagy inhibitor and activators on gastric cancer chemoresistance. Understanding the vital roles of autophagy in gastric cancer chemoresistance will provide novel opportunities to develop promising therapeutic strategies for gastric cancer.