Ubiquinol-cytochrome C reductase core protein II promotes tumorigenesis by facilitating p53 degradation

One-Shot Single-Cell Proteome and Metabolome Analysis Strategy for the Same Single Cell

Characterizing the profiles of proteome and metabolome at the single-cell level is of great significance in single-cell multiomic studies. Herein, we proposed a novel strategy called one-shot single-cell proteome and metabolome analysis (scPMA) to acquire the proteome and metabolome information in a single-cell individual in one injection of LC-MS/MS analysis. Based on the scPMA strategy, a total workflow was developed to achieve the single-cell capture, nanoliter-scale sample pretreatment, one-shot LC injection and separation of the enzyme-digested peptides and metabolites, and dual-zone MS/MS detection for proteome and metabolome profiling. Benefiting from the scPMA strategy, we realized dual-omic analysis of single tumor cells, including A549, HeLa, and HepG2 cells with 816, 578, and 293 protein groups and 72, 91, and 148 metabolites quantified on average. A single-cell perspective experiment for investigating the doxorubicin-induced antitumor effects in both the proteome and metabolome aspects was also performed.

Targeting Mitochondria with ClpP Agonists as a Novel Therapeutic Opportunity in Breast Cancer

Breast cancer is the most frequently diagnosed malignancy worldwide and the leading cause of cancer mortality in women. Despite the recent development of new therapeutics including targeted therapies and immunotherapy, triple-negative breast cancer remains an aggressive form of breast cancer, and thus improved treatments are needed. In recent decades, it has become increasingly clear that breast cancers harbor metabolic plasticity that is controlled by mitochondria. A myriad of studies provide evidence that mitochondria are essential to breast cancer progression. Mitochondria in breast cancers are widely reprogrammed to enhance energy production and biosynthesis of macromolecules required for tumor growth. In this review, we will discuss the current understanding of mitochondrial roles in breast cancers and elucidate why mitochondria are a rational therapeutic target. We will then outline the status of the use of mitochondria-targeting drugs in breast cancers, and highlight ClpP agonists as emerging mitochondria-targeting drugs with a unique mechanism of action. We also illustrate possible drug combination strategies and challenges in the future breast cancer clinic.

High-throughput proteomic characterization of seminal plasma from bulls with contrasting semen quality

Seminal plasma proteins are the major extrinsic factors that can modulate the sperm quality and functions. The present study was carried out to compare the proteomic profiles of seminal plasma from breeding bulls producing good and poor quality semen in an effort to understand the possible proteins associated with semen quality. A total of 910 and 715 proteins were detected in the seminal plasma of poor and good quality semen producing bulls, respectively. A total of 705 proteins were common to both the groups, in which 380 proteins were upregulated and 89 proteins were downregulated in the seminal plasma of poor quality semen, while 236 proteins were co-expressed. The proteins negatively influencing sperm functions such as CCL2, UQCRC2, and SAA1 were among the top ten upregulated proteins in the seminal plasma of poor quality semen. Proteins having a positive role in sperm functions (NGF, EEF1A2, COL1A2, IZUMO4, PRSS1, COL1A1, WFDC2) were among the top ten downregulated proteins in the seminal plasma of poor quality semen. The upregulation of oxidation-reduction process-related proteins, histone proteins (HIST3H2A, H2AFJ, H2AFZ, H2AFX, HIST2H2AB, H2AFV, HIST1H2AC, HIST2H2AC, LOC104975684, LOC524236, LOC614970, LOC529277), and ubiquinol-cytochrome-c reductase proteins (UQCRB, UQCRFS1, UQCRQ, UQCRC1, UQCRC2) indicate deranged oxidation-reduction equilibrium, chromatin condensation and spermatogenesis in poor quality semen producing bulls. The expression of proteins essential for motile cilium (CCDC114, CFAP206, TEKT4), chromatin integrity (PRM2), gamete fusion (IZUMO4, EQTN), hyperactivation, tyrosine phosphorylation, and capacitation [PI3K-Akt signalling pathway-related proteins (COL1A1, COL2A1, COL1A2, SPP1, PDGFA, NGF)] were down regulated in poor quality semen producing bulls.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03474-6.

Prohibitins: A Key Link between Mitochondria and Nervous System Diseases

Prohibitins (PHBs) are conserved proteins in eukaryotic cells, which are mainly located in the inner mitochondrial membrane (IMM), cell nucleus, and cell membrane. PHBs play crucial roles in various cellular functions, including the cell cycle regulation, tumor suppression, immunoglobulin M receptor binding, and aging. In addition, recent in vitro and in vivo studies have revealed that PHBs are important in nervous system diseases. PHBs can prevent apoptosis, inflammation, mitochondrial dysfunction, and autophagy in neurological disorders through different molecules and pathways, such as OPA-1, PINK1/Parkin, IL6/STAT3, Tau, NO, LC3, and TDP43. Therefore, PHBs show great promise in the protection of neurological disorders. This review summarizes the relevant studies on the relationship between PHBs and neurological disorders and provides an update on the molecular mechanisms of PHBs in nervous system diseases.

PHB2 promotes tumorigenesis via RACK1 in non-small cell lung cancer

Background: Lung cancer has the highest mortality rate among cancers worldwide, with non-small cell lung cancer (NSCLC) the most common type. Increasing evidence shows that PHB2 is highly expressed in other cancer types; however, the effects of PHB2 in NSCLC are currently poorly understood.

Method: PHB2 expression and its clinical relevance in NSCLC tumor tissues were analyzed using a tissue microarray. The biological role of PHB2 in NSCLC was investigated in vitro and in vivo using immunohistochemistry and immunofluorescence staining, gene expression knockdown and overexpression, cell proliferation assay, flow cytometry, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, wound healing assay, Transwell assay, western blot analysis, qRT-PCR, coimmunoprecipitation, and mass spectrometry analysis.

Results: Our major finding is that PHB2 facilitates tumorigenesis in NSCLC by interacting with and stabilizing RACK1, which further induces activation of downstream tumor-promoting effectors. PHB2 was found to be overexpressed in NSCLC tumor tissues, and its expression was correlated with clinicopathological features. Furthermore, PHB2 overexpression promoted proliferation, migration, and invasion, whereas PHB2 knockdown enhanced apoptosis in NSCLC cells. The stimulating effect of PHB2 on tumorigenesis was also verified in vivo. In addition, PHB2 interacted with RACK1 and increased its expression through posttranslational modification, which further induced activation of the Akt and FAK pathways.

Conclusions: Our results reveal the effects of PHB2 on tumorigenesis and its regulation of RACK1 and RACK1-associated proteins and downstream signaling in NSCLC. We believe that the crosstalk between PHB2 and RACK1 provides us with a great opportunity to design and develop novel therapeutic strategies for NSCLC.

Human Mitochondrial Pathologies of the Respiratory Chain and ATP Synthase: Contributions from Studies of Saccharomyces cerevisiae

The ease with which the unicellular yeast Saccharomyces cerevisiae can be manipulated genetically and biochemically has established this organism as a good model for the study of human mitochondrial diseases. The combined use of biochemical and molecular genetic tools has been instrumental in elucidating the functions of numerous yeast nuclear gene products with human homologs that affect a large number of metabolic and biological processes, including those housed in mitochondria. These include structural and catalytic subunits of enzymes and protein factors that impinge on the biogenesis of the respiratory chain. This article will review what is currently known about the genetics and clinical phenotypes of mitochondrial diseases of the respiratory chain and ATP synthase, with special emphasis on the contribution of information gained from pet mutants with mutations in nuclear genes that impair mitochondrial respiration. Our intent is to provide the yeast mitochondrial specialist with basic knowledge of human mitochondrial pathologies and the human specialist with information on how genes that directly and indirectly affect respiration were identified and characterized in yeast.

Antioxidants with two faces toward cancer

Antioxidants are essential in preventing the formation and suppressing the activities of reactive nitrogen and oxygen species. The aim of this study was to review the role of antioxidants in cancer development or prevention. Antioxidants are believed to prevent and treat various types of malignancies. Currently, natural antioxidant compounds have been generally consumed to prevent and treat cancers. Certainly, phenolic compounds extracted from medicinal plants have opened a new prospect with respect to the prevention and treatment of cancers due to having antioxidant characteristics. However, some recently published studies have revealed that antioxidant compounds do not indicate absolute anti-tumor properties. Some antioxidants are helpful in cancer initiation and progression. Taken together, antioxidants demonstrate a two-faced nature toward cancer. However, it is required to conduct further cell culture and in vivo studies to confirm the exact role of antioxidants and then use them for efficient cancer treatments.

Oncogenic pathways and the electron transport chain: a dangeROS liaison

Driver mutations in oncogenic pathways, rewiring of cellular metabolism and altered ROS homoeostasis are intimately connected hallmarks of cancer. Electrons derived from different metabolic processes are channelled into the mitochondrial electron transport chain (ETC) to fuel the oxidative phosphorylation process. Electrons leaking from the ETC can prematurely react with oxygen, resulting in the generation of reactive oxygen species (ROS). Several signalling pathways are affected by ROS, which act as second messengers controlling cell proliferation and survival. On the other hand, oncogenic pathways hijack the ETC, enhancing its ROS-producing capacity by increasing electron flow or by impinging on the structure and organisation of the ETC. In this review, we focus on the ETC as a source of ROS and its modulation by oncogenic pathways, which generates a vicious cycle that resets ROS levels to a higher homoeostatic set point, sustaining the cancer cell phenotype.

Zinc-finger protein p52-ZER6 accelerates colorectal cancer cell proliferation and tumour progression through promoting p53 ubiquitination

Background

Aberrant expression of p53 and its downstream gene p21 is closely related to alterations in cell cycle and cell proliferation, and is common among cancer patients. However, the underlying molecular mechanism has not been fully unravelled. ZER6 is a zinc-finger protein with two isoforms possessing different amino termini (N-termini) in their proteins, p52-ZER6 and p71-ZER6. The biological function of ZER6 isoforms, as well as their potential involvement in tumourigenesis and the regulation of p53 remain elusive.

Methods

The effect of ZER6 isoforms on p53 and p21 was determined using specific knockdown and overexpression. p52-ZER6 expression in tumours was analysed using clinical specimens, while gene modulation was used to explore p52-ZER6 roles in regulating cell proliferation and tumourigenesis. The mechanism of p52-ZER6 regulation on the p53/p21 axis was studied using molecular biology and biochemical methods.

Findings

p52-ZER6 was highly expressed in tumour tissues, and was closely related with tumour progression. Mechanistically, p52-ZER6 bound to p53 through a truncated KRAB (tKRAB) domain in its N-terminus and enhanced MDM2/p53 complex integrity, leading to increased p53 ubiquitination and degradation. p52-ZER6-silencing induced G₀-G₁ phase arrest, and subsequently reduced cell proliferation and tumourigenesis. Intriguingly, this regulation on p53 was specific to p52-ZER6, whereas p71-ZER6 did not affect p53 stability, most likely due to the presence of a HUB-1 domain.

Interpretation

We identified p52-ZER6 as a novel oncogene that enhances MDM2/p53 complex integrity, and might be a potential target for anti-cancer therapy.

ZCCHC10 suppresses lung cancer progression and cisplatin resistance by attenuating MDM2-mediated p53 ubiquitination and degradation

The activation of p53 tumor suppressor is essential for preventing abnormal cell proliferation and carcinogenesis. ZCCHC10 was previously identified as a potential p53-interacting partner in a yeast two-hybrid screen, but the interaction in cells and its subsequent influence on p53 activity and cancer development have not been investigated. In this paper, we demonstrate that ZCCHC10 expression levels are statistically lower in lung adenocarcinoma tissues than the corresponding adjacent noncancerous tissues, and decreased expression of ZCCHC10 mRNA predicts poorer survival of the patients. Ectopic expression of ZCCHC10 in lung cancer cells harboring wild-type p53 dramatically suppresses cell proliferation, colony formation, migration, invasion and cisplatin resistance in vitro, as well as tumor growth and metastasis in vivo. Conversely, knockdown of ZCCHC10 exerts opposite effects in the normal lung cell Beas-2b. However, ZCCHC10 has no influence on the biological behaviors of p53-null (H358) or p53-mutant (H1437) lung cancer cells. Mechanistically, ZCCHC10 binds and stabilizes p53 by disrupting the interaction between p53 and MDM2. The p53 inhibitor pifithrin-α attenuated the influences of ZCCHC10 overexpression on p53 pathway, cell cycle, apoptosis, and epithelial-mesenchymal transition, whereas the p53 activator Nutlin3 could reverse the effects of ZCCHC10 knockdown. Collectively, our results indicate that ZCCHC10 exerts its tumor-suppressive effects by stabilizing the p53 protein and can be used a potential prognostic marker and therapeutic target in lung adenocarcinoma.