Quantitative proteome and lysine succinylome analyses provide insights into metabolic regulation in breast cancer

CPT1A mediates the succinylation of SP5 which activates transcription of PDPK1 to promote the viability and glycolysis of prostate cancer cells

Succinylation modification involves in the progression of human cancers. The present study aimed to investigate the role of CPT1A, which is a succinyltransferase in the progression of prostate cancer (PCa). CCK-8 was used to detect the cell viability. Seahorse was performed to evaluate the cell glycolysis. Luciferase assay was used to detect the transcriptional regulation. ChIP was performed to assess the binding between transcriptional factors with the promoters. Co-IP was used to assess the binding between proteins. We found that CPT1A was highly expressed in PCa tissues and cell lines. Silencing of CPT1A inhibited the viability and glycolysis of PCa cells. Mechanistically, CPT1A promoted the succinylation of SP5, which strengthened the binding between SP5 and the promoter of PDPK1. SP5 activated PDPK1 transcription and PDPK1 activated the AKT/mTOR signal pathway. These findings might provide novel targets for the diagnosis or therapy of prostate cancer.

Comprehensive overview of how to fade into succinate dehydrogenase dysregulation in cancer cells by naringenin-loaded chitosan nanoparticles

Mitochondrial respiration complexes play a crucial function. As a result, dysfunction or change is intimately associated with many different diseases, among them cancer. The epigenetic, evolutionary, and metabolic effects of mitochondrial complex IΙ are the primary concerns of our review. Provides novel insight into the vital role of naringenin (NAR) as an intriguing flavonoid phytochemical in cancer treatment. NAR is a significant phytochemical that is a member of the flavanone group of polyphenols and is mostly present in citrus fruits, such as grapefruits, as well as other fruits and vegetables, like tomatoes and cherries, as well as foods produced from medicinal herbs. The evidence that is now available indicates that NAR, an herbal remedy, has significant pharmacological qualities and anti-cancer effects. Through a variety of mechanisms, including the induction of apoptosis, cell cycle arrest, restriction of angiogenesis, and modulation of several signaling pathways, NAR prevents the growth of cancer. However, the hydrophobic and crystalline structure of NAR is primarily responsible for its instability, limited oral bioavailability, and water solubility. Furthermore, there is no targeting and a high rate of breakdown in an acidic environment. These shortcomings are barriers to its efficient medical application. Improvement targeting NAR to mitochondrial complex ΙΙ by loading it on chitosan nanoparticles is a promising strategy.

Targeting succinylation-mediated metabolic reprogramming as a potential approach for cancer therapy

Metabolic reprogramming is a common hallmark of cancers and involves alterations in many metabolic pathways during tumor initiation and progression. However, the cancer-specific modulation of metabolic reprogramming requires further elucidation. Succinylation, a newly identified protein posttranslational modification (PTM), participates in many cellular processes by transferring a succinyl group to a residue of the target protein, which is related to various pathological disorders including cancers. In recent years, there has been a gradual increase in the number of studies on the regulation of tumors by protein succinylation. Notably, accumulating evidence suggests that succinylation can mediate cancer cell metabolism by altering the structure or activity of metabolism-related proteins and plays vital roles in metabolic reprogramming. Furthermore, some antitumor drugs have been linked to succinylation-mediated tumor-associated metabolism. To better elucidate lysine succinylation mediated tumor metabolic reprogramming, this review mainly summarizes recent studies on the regulation and effects of protein succinylation in tumors, focusing on the metabolic regulation of tumorigenesis and development, which will provide new directions for cancer diagnosis as well as possible therapeutic targets.

A review of the mechanism of succinylation in cancer

Lysine succinylation is a novel, broad-spectrum, dynamic, non-enzymatic protein post-translational modification (PTM). Succinylation is essential for the regulation of protein function and control of various signaling and regulatory pathways. It is involved in several life activities, including glucose metabolism, amino acid metabolism, fatty acid metabolism, ketone body synthesis, and reactive oxygen species clearance, by regulating protease activity and gene expression. The level of succinylation is mainly regulated by succinyl donor, succinyltransferase, and desuccinylase. Many studies have confirmed that succinylation plays a role in tumorigenesis by creating tissue heterogeneity, and can promote or inhibit various cancers via the regulation of different substrate targets or signaling pathways. The mechanism of action of some antineoplastic drugs is related to succinylation. To better understand the role of succinylation modification in cancer development and treatment, the present study reviewed the current research content and latest progress of succinylation modification in cancer, which might provide a new direction and target for the prevention and treatment of cancer.

Understanding emerging bioactive metabolites with putative roles in cancer biology

Dysregulated metabolism in cancers is, by now, well established. Although metabolic adaptations provide cancers with the ability to synthesize the precursors required for rapid biosynthesis, some metabolites have direct functional, or bioactive, effects in human cells. Here we summarize recently identified metabolites that have bioactive roles either as post-translational modifications (PTMs) on proteins or in, yet unknown ways. We propose that these metabolites could play a bioactive role in promoting or inhibiting cancer cell phenotypes in a manner that is mostly unexplored. To study these potentially important bioactive roles, we discuss several novel metabolomic and proteomic approaches aimed at defining novel PTMs and metabolite-protein interactions. Understanding metabolite PTMs and protein interactors of bioactive metabolites may provide entirely new therapeutic targets for cancer.

SIRT5 Is the desuccinylase of LDHA as novel cancer metastatic stimulator in aggressive prostate cancer

Prostate cancer (PCa) is the most commonly diagnosed genital cancer in men worldwide. Among patients who developed advanced PCa, 80% suffered from bone metastasis, with a sharp drop in the survival rate. Despite great efforts, the detail of the mechanisms underlying castration-resistant PCa (CRPC) remain unclear. Sirtuin 5 (SIRT5), an NAD⁺-dependent desuccinylase, is hypothesized to be a key regulator of various cancers. However, compared to other SIRTs, the role of SIRT5 in cancer has not been extensively studied. Here, we showed significantly decreased SIRT5 levels in aggressive PCa cells relative to the PCa stages. The correlation between the decrease in the SIRT5 level and the patient's survival rate was also confirmed. Using quantitative global succinylome analysis, we characterized a significant increase of lysine 118 succinylation (K118su) of lactate dehydrogenase A (LDHA), which plays a role in increasing LDH activity. As a substrate of SIRT5, LDHA-K118su significantly increased the migration and invasion of PCa cells and LDH activity in PCa patients. This study investigated the reduction of SIRT5 and LDHA-K118su as a novel mechanism involved in PCa progression, which can also be proposed as a new target that can prevent CPRC progression, which is key to PCa treatment.

The Crucial Roles of Intermediate Metabolites in Cancer

Metabolic alteration, one of the hallmarks of cancer cells, is important for cancer initiation and development. To support their rapid growth, cancer cells alter their metabolism so as to obtain the necessary energy and building blocks for biosynthetic pathways, as well as to adjust their redox balance. Once thought to be merely byproducts of metabolic pathways, intermediate metabolites are now known to mediate epigenetic modifications and protein post-transcriptional modifications (PTM), as well as connect cellular metabolism with signal transduction. Consequently, they can affect a myriad of processes, including proliferation, apoptosis, and immunity. In this review, we summarize multiple representative metabolites involved in glycolysis, the pentose phosphate pathway (PPP), the tricarboxylic acid (TCA) cycle, lipid synthesis, ketogenesis, methionine metabolism, glutamine metabolism, and tryptophan metabolism, focusing on their roles in chromatin and protein modifications and as signal-transducing messengers.

From Metabolism to Genetics and Vice Versa: The Rising Role of Oncometabolites in Cancer Development and Therapy

Over the last decades, the study of cancer metabolism has returned to the forefront of cancer research and challenged the role of genetics in the understanding of cancer development. One of the major impulses of this new trend came from the discovery of oncometabolites, metabolic intermediates whose abnormal cellular accumulation triggers oncogenic signalling and tumorigenesis. These findings have led to reconsideration and support for the long-forgotten hypothesis of Warburg of altered metabolism as oncogenic driver of cancer and started a novel paradigm whereby mitochondrial metabolites play a pivotal role in malignant transformation. In this review, we describe the evolution of the cancer metabolism research from a historical perspective up to the oncometabolites discovery that spawned the new vision of cancer as a metabolic disease. The oncometabolites’ mechanisms of cellular transformation and their contribution to the development of new targeted cancer therapies together with their drawbacks are further reviewed and discussed.

Systematic analysis of lysine acetylome and succinylome reveals the correlation between modification of H2A.X complexes and DNA damage response in breast cancer

Abnormal protein acetylation and succinylation in lysine residues can cause the initiation and development of numerous different types of tumors. However, to the best of our knowledge, there is currently a lack of systematic investigation in breast cancer. Using proteomic techniques, the present study systematically investigated the two modifications of all proteins in invasive ductal carcinoma tissues to identify potential targets. The results revealed significantly higher modification levels for the majority of proteins in breast cancer tissue when compared with para‑carcinomous normal tissue. The bioinformatic analysis demonstrated that either highly acetylated or succinylated proteins were significantly enriched in histone H2A.X (H2A.X) complexes and nucleophosmin (NPM1) may be the key member among them. The results of further analyses revealed that H2A.X complexes were associated with DNA damage response (DDR), and the proteomic results for protein quantification provided further evidence for the abnormal DDR condition in breast cancer tissues. Later, the western blotting results validated the high acetylation and succinylation levels of the majority of proteins, including the modification of NPM1 and its correlation with cell viability. Finally, the upregulation of H2A.X in breast cancer tissues further demonstrated the association between H2A.X complex modification and DDR in breast cancer. Overall, the present study systematically investigated the protein acetylation and succinylation in breast cancer and provided evidence to support H2A.X complexes as potential targets. These results broaden the horizon for breast cancer investigation and link it with epigenetics.

Characterization and Identification of Lysine Succinylation Sites based on Deep Learning Method

Succinylation is a type of protein post-translational modification (PTM), which can play important roles in a variety of cellular processes. Due to an increasing number of site-specific succinylated peptides obtained from high-throughput mass spectrometry (MS), various tools have been developed for computationally identifying succinylated sites on proteins. However, most of these tools predict succinylation sites based on traditional machine learning methods. Hence, this work aimed to carry out the succinylation site prediction based on a deep learning model. The abundance of MS-verified succinylated peptides enabled the investigation of substrate site specificity of succinylation sites through sequence-based attributes, such as position-specific amino acid composition, the composition of k-spaced amino acid pairs (CKSAAP), and position-specific scoring matrix (PSSM). Additionally, the maximal dependence decomposition (MDD) was adopted to detect the substrate signatures of lysine succinylation sites by dividing all succinylated sequences into several groups with conserved substrate motifs. According to the results of ten-fold cross-validation, the deep learning model trained using PSSM and informative CKSAAP attributes can reach the best predictive performance and also perform better than traditional machine-learning methods. Moreover, an independent testing dataset that truly did not exist in the training dataset was used to compare the proposed method with six existing prediction tools. The testing dataset comprised of 218 positive and 2621 negative instances, and the proposed model could yield a promising performance with 84.40% sensitivity, 86.99% specificity, 86.79% accuracy, and an MCC value of 0.489. Finally, the proposed method has been implemented as a web-based prediction tool (CNN-SuccSite), which is now freely accessible at http://csb.cse.yzu.edu.tw/CNN-SuccSite/.

Discovery and Identification of Serum Succinyl-Proteome for Postmenopausal Women with Osteoporosis and Osteopenia

OBJECTIVE

For the purpose of providing evidence for the treatment of osteoporosis and osteopenia, this study retrospectively identified succinylation-modified sites and proteins in postmenopausal women, and bioinformatics analysis were performed.

METHODS

From January 2016 to June 2018, a total of 30 postmenopausal women aged from 55 to 70 years old were assigned to three groups: 10 cases with osteoporosis; 10 cases with osteopenia; and 10 cases with normal bone mass. Subsequently, the serum samples were collected from all cases for succinyl-proteome. Measures comprised label-free quantitative analysis, succinylation enrichment techniques, the liquid chromatograph-mass spectrometer/mass spectrometer (LC-MS/MS) methods, and bioinformatics.

RESULTS

A total of 113 succinylation sites on 35 proteins were identified based on quantitative information. The variation of the different multiple folds were more than 1.2 times as a significant increase for up-regulated and less than 1/1.2 times as a significant decrease for down-regulated. Among the quantified succinylation sites, 66 were up-regulated and 11 down-regulated in the Osteopenia/Normal comparison group, 24 were up-regulated and 44 down-regulated in the Osteoporosis/Osteopenia comparison group, 45 were up-regulated and 32 down-regulated in the Osteoporosis/Normal comparison group. Among the quantified succinylation proteins, 24 were up-regulated and 7 down-regulated in the Osteopenia/Normal comparison group, 15 were up-regulated and 20 down-regulated in the Osteoporosis/Osteopenia comparison group, 20 were up-regulated and 17 down-regulated in the Osteoporosis/Normal comparison group. The percentage of proteins differed in immune response, signaling pathway, proteolysis, lymphocyte, leukocyte, and cell activation. Four differentially expressed proteins (apolipoprotein A-I, apolipoprotein A-II, hemoglobin subunit alpha, and haptoglobin) contained quantitative information; they were mediated with receptors, factors, mechanisms, that related to bone metabolism. Hemoglobin subunit alpha was screened for diagnosis of osteopenia.

CONCLUSIONS

The succinyl-proteome experimental data indicated that apolipoprotein A-I, apolipoprotein A-II, hemoglobin subunit alpha, and haptoglobin were valuable for diagnosis and treatment in postmenopausal women with osteoporosis and osteopenia.

Regulation of succinate dehydrogenase and role of succinate in cancer

Succinate dehydrogenase (SDH) has been classically considered a mitochondrial enzyme with the unique property to participate in both the citric acid cycle and the electron transport chain. However, in recent years, several studies have highlighted the role of the SDH substrate, i.e. succinate, in biological processes other than metabolism, tumorigenesis being the most remarkable. For this reason, SDH has now been defined a tumor suppressor and succinate an oncometabolite. In this review, we discuss recent findings regarding alterations in SDH activity leading to succinate accumulation, which include SDH mutations, regulation of mRNA expression, post-translational modifications and endogenous SDH inhibitors. Further, we report an extensive examination of the role of succinate in cancer development through the induction of epigenetic and metabolic alterations and the effects on epithelial to mesenchymal transition, cell migration and invasion, and angiogenesis. Finally, we have focused on succinate and SDH as diagnostic markers for cancers having altered SDH expression/activity.