Autophagy defects suggested by low levels of autophagy activator MAP1S and high levels of autophagy inhibitor LRPPRC predict poor prognosis of prostate cancer patients

Exosomes from polarized Microglia: Proteomic insights into potential mechanisms affecting intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a devastating form of stroke associated with significant morbidity and mortality. Microglia are intracranial innate immune cell that play critical roles in Intracerebral hemorrhage through direct or indirect means. Vesicle transport is a fundamental mechanism of intercellular communication. Recent studies have identified microglia in specific polarized states correlate with pathogenesis, material and signal transmission in ICH through derived extracellular vesicles. Diverse polarization states trigger distinct functions, however, the exosome proteomes across these states remain poorly characterized. Here, we hypothesized that microglia exosomal profiles vary with polarization states, impacting their functional repertoire and influencing outcomes in cerebral hemorrhage. In vitro model of cerebral hemorrhage, administration of 20 μg/ml LPS-induced M1 microglia derived exosomes (M1-Exo) with HT22 enhanced hemin-induced neuronal death, while IL-4-induced M2 microglia derived exosomes (M2-Exo) significantly reduced hemin-induced cell apoptosis and inflammation. Then we identified novel state-specific proteomic profiles of microglia-derived exosomes under these polarization conditions through label-free quantitative mass spectrometry (LFQ-MS). Analysis of protein content identified several exosomal signature proteins and hundreds of differentially expressed proteins across polarization states. Specifically, proteins including UMOD, NLRP3, ACOD1, IL1RN, heme oxygenase 1 (HMOX1), CCL4, and TNFRSF1B in M1-Exo were enriched in inflammatory pathways, while those in M2-Exo exhibited enrichment in autophagy, ubiquitination, and mitochondrial respiration. The analysis of those diverse exosomal proteins suggested unique proteomic profiles and possible intracellular signal transmission and regulation mechanisms. Together, these findings offer new insights and resources for studying microglia-derived exosome and pave the way for the development of novel therapeutic strategies targeting microglial exosome-mediated pathways.

HBx-induced upregulation of MAP1S drives hepatocellular carcinoma proliferation and migration via MAP1S/Smad/TGF-β1 loop

Hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC), has a significantly higher risk of recurrence. However, the exact mechanism by which HBV prompts HCC recurrence remains largely unknown. In this study liver microarray test revealed significant upregulation of microtubule associated protein 1S (MAP1S) in metastatic HCC compared to control. MAP1S knockdown suppressed growth of HCCLM3 cells in vitro and in vivo. Mechanistically, HBV-encoded X protein (HBx) upregulates MAP1S, which enhances microtubule (MT) acetylation by promoting the degradation of histone deacetylase 6 (HDAC6), and facilitates the nuclear translocation of Smad complex, and thereby enhancing downstream TGF-β signaling. Smad complex, in turn, increases MAP1S, establishing a feedback loop of MAP1S/Smad/TGF-β1. Finally, survival analysis of 150 HBV-associated HCC patients demonstrated both increased MAP1S and decreased HDAC6 were significantly associated with shorter relapse-free survival. Collectively, this study reveals a unique mechanism whereby HBx-induced upregulation of MAP1S drives HBV-related HCC proliferation and migration through the MAP1S/Smad/TGF-β1 feedback loop. TEASER: MAP1S is a key link between HBV infection and a higher risk of metastatic recurrence of HCC.

Autophagy, a critical element in the aging male reproductive disorders and prostate cancer: a therapeutic point of view

Autophagy is a highly conserved, lysosome-dependent biological mechanism involved in the degradation and recycling of cellular components. There is growing evidence that autophagy is related to male reproductive biology, particularly spermatogenic and endocrinologic processes closely associated with male sexual and reproductive health. In recent decades, problems such as decreasing sperm count, erectile dysfunction, and infertility have worsened. In addition, reproductive health is closely related to overall health and comorbidity in aging men. In this review, we will outline the role of autophagy as a new player in aging male reproductive dysfunction and prostate cancer. We first provide an overview of the mechanisms of autophagy and its role in regulating male reproductive cells. We then focus on the link between autophagy and aging-related diseases. This is followed by a discussion of therapeutic strategies targeting autophagy before we end with limitations of current studies and suggestions for future developments in the field.

The Role of RNA Methylation Modification Related Genes in Prognosis and Immunotherapy of Colorectal Cancer

Background

Researches showed RNA methylation genes can affect the prognosis of tumors. Thus, the study aimed to comprehensively analyze the effects of RNA methylation regulatory genes in prognosis and treatment of colorectal cancer (CRC).

Methods

Prognostic signature associated with CRCs were constructed by differential expression analysis, Cox and Least Absolute Shrinkage and Selection Operator (LASSO) analyses. Receiver operating characteristic (ROC) and Kaplan-Meier survival analyses were used to validate the reliability of the developed model. Gene Ontology (GO), Gene set variation analysis (GSVA), and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed for functional annotation. Finally, normal and cancerous tissue were collected to validate gene by quantitative real-time PCR (qRT-PCR).

Results

A prognostic risk model based on leucine rich pentatricopeptide repeat containing (LRPPRC) and ubiquitin-like with PHD and ring finger domains 2 (UHRF2) was constructed and relevant to the overall survival (OS) of CRC. Functional enrichment analysis revealed that collagen fibrous tissue, ion channel complex and other pathways were significantly enriched, which might help explain the underlying molecular mechanisms. There were significant differences in ImmuneScore, StromalScore, ESTIMATEScore between high- and low-risk groups (p < 0.05). Ultimately, qRT-PCR validation showed that a significant upregulation in the expression of LRPPRC and UHRF2 in cancerous tissue, which verified the effectiveness of our signature.

Conclusion

In conclusion, 2 prognostic genes (LRPPRC and UHRF2) related to RNA methylation were identified by bioinformatics analysis, which might supply a new insight into the treatment and evaluation of CRC.

Spermidine suppresses the activation of hepatic stellate cells to cure liver fibrosis through autophagy activator MAP1S

BACKGROUND AND AIMS

Liver diseases present a wide range of fibrosis, from fatty liver with no inflammation to steatohepatitis with varying degrees of fibrosis, to established cirrhosis leading to HCC. In a multivariate analysis, serum levels of spermidine were chosen as the top metabolite from 237 metabolites and its levels were drastically reduced along with progression to advanced steatohepatitis. Our previous studies that showed spermidine supplementation helps mice prevent liver fibrosis through MAP1S have prompted us to explore the possibility that spermidine can alleviate or cure already developed liver fibrosis.

METHODS

We collected tissue samples from patients with liver fibrosis to measure the levels of MAP1S. We treated wild-type and MAP1S knockout mice with CCl₄ -induced liver fibrosis with spermidine and isolated HSCs in culture to test the effects of spermidine on HSC activation and liver fibrosis.

RESULTS

Patients with increasing degrees of liver fibrosis had reduced levels of MAP1S. Supplementing spermidine in mice that had already developed liver fibrosis after 1 month of CCl₄ induction for an additional 3 months resulted in significant reductions in levels of ECM proteins and a remarkable improvement in liver fibrosis through MAP1S. Spermidine also suppressed HSC activation by reducing ECM proteins at both the mRNA and protein levels, and increasing the number of lipid droplets in stellate cells.

CONCLUSIONS

Spermidine supplementation is a potentially clinically meaningful approach to treating and curing liver fibrosis, preventing cirrhosis and HCC in patients.

Identification of immuno-infiltrating MAP1A as a prognosis-related biomarker for bladder cancer and its ceRNA network construction

BACKGROUNDS

Approximately 75% of bladder cancer occurrences are of the non-muscle-invasive type. The estimated five-year survival rate is 26%-55%. Currently, there is no reliable biomarker available for early diagnosis and prognosis of bladder cancer. The present study aims to identify a biomarker using bioinformatic approaches to provide a new insight in clinical research for early diagnosis and prognosis of bladder cancer.

METHODS

Clinical data and a transcriptome of bladder cancer were obtained from TCGA, GEO, GETx, and UCSC Xena. The differential expressed gene (DEG) analysis, weighted gene co-expression network analysis (WGCNA), and survival analysis using the Kaplan-Meier and Cox proportional-hazards models were used to identify the Microtubule-associated Proteins 1A (MAP1A). on overall survival (OS) and disease-free survival (DFS) was analyzed using GEPIA and GETx databases. The TIMER 2.0 database predicted the correlation between MAP1A and immunocytes and immune checkpoints. Target prediction of the regulated competing endogenous RNAs (ceRNAs) network of MAP1A was performed using starBase and TargetScan. Cystoscope v3.7.2 software was used to visualize the ceRNA coexpression network. The R programming language v4.0.2 was applied as an analytic tool. Gene expression of MAP1A verified by RT-qPCR.

RESULTS

The low expression of MAP1A was verified in bladder cancer tissues and bladder cancer cell lines SW780 and 5637. P < 0.001 were obtained by Kaplan-Meier survival analysis and Cox proportional hazards model, with a hazard ratio (HR) of 1.4. Significant correlations between MAP1A and OS (P < 0.001, HR = 1.9) as well as DFS (P < 0.05, HR = 1.7) in bladder cancer were identified through gene expression profiling interactive analysis (GEPIA), indicating MAP1A may be a high-risk factor. Significant correlation in single copy-number variation of MAP1A gene with CD8⁺ T cells, and myeloid dendritic cells (MDCs) (P < 0.05) was noted. MAP1A expression was shown to be significantly correlated with the amount of CD4⁺ T cells and CD8⁺ T cells, MDCs, macrophages, and neutrophils in a statistically significant positive manner (P < 0.001). However, the MAP1A expression demonstrated a strong negative connection with B cells (P < 0.001). Except for macrophage M1 genes IRF5 and PTGS2, MAP1A expression was significantly correlated with the gene levels in immunocytes such as CD4⁺ T cells, CD8⁺ T cells, B cells, dendritic cells (DCs), macrophages, and neutrophils (Cor > 0.2, P < 0.001), as well as immune checkpoint related genes including cytotoxic t-lymphocyte-associated protein 4 (CTLA-4), programmed death 1 (PD-1), programmed death ligand 1 (PD-L1) (P < 0.001). Finally, we predicted that the MAP1A-interacting miRNA was miR-34a-5p, and the MAP1A endogenous competing RNAs were LNC00667, circ_MAP1B, and circ_MYLK, respectively. These findings support the need for further studies on the mechanism underlying the pathogenesis of this disease.

CONCLUSION

MAP1A is considered as a prospective biomarker for early diagnosis, therapeutic observation, and prognosis analysis in bladder cancer.

Targeting autophagy in prostate cancer: preclinical and clinical evidence for therapeutic response

Prostate cancer is a leading cause of death worldwide and new estimates revealed prostate cancer as the leading cause of death in men in 2021. Therefore, new strategies are pertinent in the treatment of this malignant disease. Macroautophagy/autophagy is a “self-degradation” mechanism capable of facilitating the turnover of long-lived and toxic macromolecules and organelles. Recently, attention has been drawn towards the role of autophagy in cancer and how its modulation provides effective cancer therapy. In the present review, we provide a mechanistic discussion of autophagy in prostate cancer. Autophagy can promote/inhibit proliferation and survival of prostate cancer cells. Besides, metastasis of prostate cancer cells is affected (via induction and inhibition) by autophagy. Autophagy can affect the response of prostate cancer cells to therapy such as chemotherapy and radiotherapy, given the close association between autophagy and apoptosis. Increasing evidence has demonstrated that upstream mediators such as AMPK, non-coding RNAs, KLF5, MTOR and others regulate autophagy in prostate cancer. Anti-tumor compounds, for instance phytochemicals, dually inhibit or induce autophagy in prostate cancer therapy. For improving prostate cancer therapy, nanotherapeutics such as chitosan nanoparticles have been developed. With respect to the context-dependent role of autophagy in prostate cancer, genetic tools such as siRNA and CRISPR-Cas9 can be utilized for targeting autophagic genes. Finally, these findings can be translated into preclinical and clinical studies to improve survival and prognosis of prostate cancer patients.

• Prostate cancer is among the leading causes of death in men where targeting autophagy is of importance in treatment;

• Autophagy governs proliferation and metastasis capacity of prostate cancer cells;

• Autophagy modulation is of interest in improving the therapeutic response of prostate cancer cells;

• Molecular pathways, especially involving non-coding RNAs, regulate autophagy in prostate cancer;

• Autophagy possesses both diagnostic and prognostic roles in prostate cancer, with promises for clinical application.

SQSTM1 Expression in Hepatocellular Carcinoma and Relation to Tumor Recurrence After Radiofrequency Ablation

BACKGROUND/AIMS

Autophagy is a process that allows the degradation of detrimental components through the lysosome to maintain cellular homeostasis under variable stimuli. SQSTM1 is a key molecule involved in functional autophagy and is linked to different signaling pathways, oxidative responses, and inflammation. Dysregulation of autophagy is reported in a broad spectrum of diseases. Accumulation of SQSTM1 reflects impaired autophagy, which is related to carcinogenesis and progression of various tumors, including hepatocellular carcinoma (HCC). This study investigated SQSTM1 protein expression in HCC and its relation to the clinicopathological features and the likelihood of tumor recurrence after radiofrequency ablation (RFA).

METHODS

This study included 50 patients with cirrhotic HCC of Barcelona Clinic Liver Cancer stages 0/A-B eligible for RFA. Tumor and peritumor biopsies were obtained just prior to local ablation and assessed for tumor pathological grade and SQSTM1 expression by immunohistochemistry. Patients were followed for one year after achieving complete ablation to detect any tumor recurrence.

RESULTS

Serum alpha-fetoprotein level (U = 149.50, P = 0.027∗) and pathological grade of the tumor (χ² = 12.702, P = 0.002∗) associated significantly with the tumor response to RFA. SQSTM1 expression level was significantly increased in HCC compared to the adjacent peritumor cirrhotic liver tissues (Z = 5.927, P < 0.001∗). Significant direct relation was found between SQSTM1 expression level in HCC and the pathological grade of the tumor (H = 33.789, P < 0.001∗). On follow-up, tumor and peritumor SQSTM1 expression levels performed significantly as a potential predictor of the overall survival, but not the disease recurrence.

CONCLUSIONS

SQSTM1 expression could determine aggressive HCC, even with reasonable tumor size and number, and identify the subset of HCC patients with short overall survival and unfavorable prognosis. SQSTM1 expression could not predict post-RFA intrahepatic HCC recurrence. SQSTM1 may be a potential biomarker and target for the selection of HCC patients for future therapies.

LRPPRC regulates redox homeostasis via the circANKHD1/FOXM1 axis to enhance bladder urothelial carcinoma tumorigenesis

Reactive oxygen species (ROS) which are continuously generated mainly by mitochondria, have been proved to play an important role in the stress signaling of cancer cells. Moreover, pentatricopeptide repeat (PPR) proteins have been suggested to take part in mitochondrial metabolism. However, the mechanisms integrating the actions of these distinct networks in urothelial carcinoma of the bladder (UCB) pathogenesis are elusive. In this study, we found that leucine rich pentatricopeptide repeat containing (LRPPRC) was frequently upregulated in UCB and that it was an independent prognostic factor in UCB. We further revealed that LRPPRC promoted UCB tumorigenesis by regulating the intracellular ROS homeostasis. Mechanistically, LRPPRC modulates ROS balance and protects UCB cells from oxidative stress via mt-mRNA metabolism and the circANKHD1/FOXM1 axis. In addition, the SRA stem-loop interacting RNA binding protein (SLIRP) directly interacted with LRPPRC to protect it from ubiquitination and proteasomal degradation. Notably, we showed that LRPPRC modulated the tumorigenesis of UCB cells in a circANKHD1-FOXM1-dependent manner. In conclusion, LRPPRC exerts critical roles in regulating UCB redox homeostasis and tumorigenesis, and is a prognostic factor for UCB; suggesting that LRPPRC may serve as an exploitable therapeutic target in UCB.

m6A-Mediated Tumor Invasion and Methylation Modification in Breast Cancer Microenvironment

Background

We analyzed the n6-methyladenosine (m6A) modification patterns of immune cells infiltrating the tumor microenvironment of breast cancer (BC) to provide a new perspective for the early diagnosis and treatment of BC.

Methods

Based on 23 m6A regulatory factors, we identified m6A-related gene characteristics and m6A modification patterns in BC through unsupervised cluster analysis. To examine the differences in biological processes among various m6A modification modes, we performed genomic variation analysis. We then quantified the relative infiltration levels of different immune cell subpopulations in the tumor microenvironment of BC using the CIBERSORT algorithm and single-sample gene set enrichment analysis. Univariate Cox analysis was used to screen for m6A characteristic genes related to prognosis. Finally, we evaluated the m6A modification pattern of patients with a single BC by constructing the m6Ascore based on principal component analysis.

Results

We identified three different m6A modification patterns in 2128 BC samples. A higher abundance of the immune infiltration of the m6Acluster C was indicated by the results of CIBERSORT and the single-sample gene set enrichment analysis. Based on the m6A characteristic genes obtained through screening, the m6Ascore was determined. The BC patients were segregated into m6Ascore groups of low and high categories, which revealed significant survival benefits among patients with low m6Ascores. Additionally, the high-m6Ascore group had a higher mutation frequency and was associated with low PD-L1 expression, and the m6Ascore and tumor mutation burden showed a positive correlation. In addition, treatment effects were better in patients in the high-m6Ascore group.

Conclusions

In case of a single patient with BC, the immune cell infiltration characteristics of the tumor microenvironment and the m6A methylation modification pattern could be evaluated using the m6Ascore. Our results provide a foundation for improving personalized immunotherapy of BC.

Reactive Oxygen Species Mediate 6c-Induced Mitochondrial and Lysosomal Dysfunction, Autophagic Cell Death, and DNA Damage in Hepatocellular Carcinoma

Increasing the level of reactive oxygen species (ROS) in cancer cells has been suggested as a viable approach to cancer therapy. Our previous study has demonstrated that mitochondria-targeted flavone-naphthalimide-polyamine conjugate 6c elevates the level of ROS in cancer cells. However, the detailed role of ROS in 6c-treated cancer cells is not clearly stated. The biological effects and in-depth mechanisms of 6c in cancer cells need to be further investigated. In this study, we confirmed that mitochondria are the main source of 6c-induced ROS, as demonstrated by an increase in 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) and MitoSox fluorescence. Compound 6c-induced mitochondrial ROS caused mitochondrial dysfunction and lysosomal destabilization confirmed by absolute quantitation (iTRAQ)-based comparative proteomics. Compound 6c-induced metabolic pathway dysfunction and lysosomal destabilization was attenuated by N-acetyl-L-cysteine (NAC). iTRAQ-based comparative proteomics showed that ROS regulated the expression of 6c-mediated proteins, and treatment with 6c promoted the formation of autophagosomes depending on ROS. Compound 6c-induced DNA damage was characterized by comet assay, p53 phosphorylation, and γH2A.X, which was diminished by pretreatment with NAC. Compound 6c-induced cell death was partially reversed by 3-methyladenine (3-MA), bafilomycin (BAF) A1, and NAC, respectively. Taken together, the data obtained in our study highlighted the involvement of mitochondrial ROS in 6c-induced autophagic cell death, mitochondrial and lysosomal dysfunction, and DNA damage.

Construction and Validation of an Autophagy-Related Prognostic Signature and a Nomogram for Bladder Cancer

Objective

Bladder cancer (BC) is one of the top ten cancers endangering human health but we still lack accurate tools for BC patients’ risk stratification. This study aimed to develop an autophagy-related signature that could predict the prognosis of BC. In order to provide clinical doctors with a visual tool that could precisely predict the survival probability of BC patients, we also attempted to establish a nomogram based on the risk signature.

Methods

We screened out autophagy-related genes (ARGs) combining weighted gene co-expression network analysis (WGCNA) and differentially expressed gene (DEG) in BC. Based on the screened ARGs, we performed survival analysis and Cox regression analysis to identify potential prognostic biomarkers. A risk signature based on the prognostic ARGs by multivariate Cox regression analysis was established, which was validated by using seven datasets. To provide clinical doctors with a useful tool for survival possibility prediction, a nomogram assessed by the ARG-based signature and clinicopathological features was constructed, verified using four independent datasets.

Results

Three prognostic biomarkers including BOC (P = 0.008, HR = 1.104), FGF7(P = 0.030, HR = 1.066), and MAP1A (P = 0.001, HR = 1.173) were identified and validated. An autophagy-related risk signature was established and validated. This signature could act as an independent prognostic feature in patients with BC (P = 0.047, HR = 1.419). We then constructed two nomograms with and without ARG-based signature and subsequent analysis indicated that the nomogram with ARG signature showed high accuracy for overall survival probability prediction of patients with BC (C-index = 0.732, AUC = 0.816). These results proved that the ARG signature improved the clinical net benefit of the standard model based on clinicopathological features (age, pathologic stage).

Conclusions

Three ARGs were identified as prognosis biomarkers in BC. An ARG-based signature was established for the first time, showing strong potential for prognosis prediction in BC. This signature was proven to improve the clinical net benefit of the standard model. A nomogram was established using this signature, which could lead to more effective prognosis prediction for BC patients.

Alzheimer's and Parkinson's brain tissues have reduced expression of genes for mtDNA OXPHOS Proteins, mitobiogenesis regulator PGC-1α protein and mtRNA stabilizing protein LRPPRC (LRP130)

We used RNA sequencing (RNA-seq) to quantitate gene expression in total RNA extracts of vulnerable brain tissues from Alzheimer's disease (AD, frontal cortical ribbon) and Parkinson's disease (PD, ventral midbrain) subjects and phenotypically negative control subjects. Paired-end sequencing files were processed with HISAT2 aligner/Cufflinks quantitation against the hg38 human genome. We observed a significant decrease in gene expression of all mtDNA OXPHOS genes in AD and PD tissues. Gene expression of the master mitochondrial biogenesis regulator PGC-1α (PPARGC1A) was significantly reduced in AD; expression of genes for mitochondrial transcription factors A (TFAM) and B1/B2 (TFB1M/TFB2M) were not significantly changed in AD and PD tissues. 2-way ANOVAs showed significant reduction in AD brain Complex I subunits' expressions and nearly significant reductions in PD brain. We found a significant reduction in both AD and PD brain samples of expression of genes for leucine-rich pentatricopeptide repeat containing (LRPPRC, a.k.a. LRP130), a known mtRNA-stabilizing protein. Our findings suggest that AD and PD brain tissues have a reduction in mitochondrial ATP production derived from a reduction of mitobiogenesis and mtRNA stability. If true, increased brain expression of PGC-1α and/or LRPPRC may improve bioenergetics of AD and PD and alter the course of neurodegeneration in both conditions. (201 words).

LRPPRC sustains Yap-P27-mediated cell ploidy and P62-HDAC6-mediated autophagy maturation and suppresses genome instability and hepatocellular carcinomas

Mutants in the gene encoding mitochondrion-associated protein LRPPRC were found to be associated with French Canadian Type Leigh syndrome, a human disorder characterized with neurodegeneration and cytochrome c oxidase deficiency. LRPPRC interacts with one of microtubule-associated protein family MAP1S that promotes autophagy initiation and maturation to suppress genomic instability and tumorigenesis. Previously, although various studies have attributed LRPPRC nuclear acid-associated functions, we characterized that LRPPRC acted as an inhibitor of autophagy in human cancer cells. Here we show that liver-specific deletion of LRPPRC causes liver-specific increases of YAP and P27 and decreases of P62, leading to an increase of cell polyploidy and an impairment of autophagy maturation. The blockade of autophagy maturation and promotion of polyploidy caused by LRPPRC depletion synergistically enhances diethylnitrosamine-induced DNA damage, genome instability, and further tumorigenesis so that LRPPRC knockout mice develop more and larger hepatocellular carcinomas and survive a shorter lifespan. Therefore, LRPPRC suppresses genome instability and hepatocellular carcinomas and promotes survivals in mice by sustaining Yap-P27-mediated cell ploidy and P62-HDAC6-controlled autophagy maturation.

p62 promotes proliferation, apoptosis‑resistance and invasion of prostate cancer cells through the Keap1/Nrf2/ARE axis

Prostate cancer poses a public health threat to hundreds of people around the world. p62 has been identified as a tumor suppressor, however, the mechanism by which p62 promotes prostate cancer remains poorly understood. The present study aimed to investigate whether p62 promotes proliferation, apoptosis resistance and invasion of prostate cancer cells via the Kelch-like ECH-associated protein 1/nuclear factor erytheroid-derived 2-like 2/antioxidant response element (Keap1/Nrf2/ARE) axis. Immunohistochemical staining and immunoblotting were performed to determine the protein levels. Rates of proliferation, invasion and apoptosis of prostate cancer cells were assessed using an RTCA system and flow cytometric assays. Levels of reactive oxygen species (ROS) were assessed using Cell ROX Orange reagent and mRNA levels of Nrf2 target genes were detected by qRT-PCR. It was revealed that p62 increased the levels and activities of Nrf2 by suppressing Keap1-mediated proteasomal degradation in prostate cancer cells and tissues, and high levels of p62 promoted growth of prostate cancer through the Keap1/Nrf2/ARE system. Silencing of Nrf2 in DU145 cells overexpressing p62 led to decreases in the rate of cell proliferation and invasion and an increase in the rate of cell apoptosis. p62 activated the Nrf2 pathway, promoted the transcription of Nrf2-mediated target genes and suppressed ROS in prostate cancer. Therefore, p62 promoted the development of prostate cancer by activating the Keap1/Nrf2/ARE pathway and decreasing p62 may provide a new strategy to ameliorate tumor aggressiveness and suppress tumorigenesis to improve clinical outcomes.

Proteasome-Independent Protein Knockdown by Small-Molecule Inhibitor for the Undruggable Lung Adenocarcinoma

Therapeutic target identification and corresponding drug development is a demanding task for the treatment of lung adenocarcinoma, especially the most malignant proximal-proliferative subtype without druggable protein kinase mutations. Using a cell-SELEX-generated aptamer, we discovered a new tumor driver protein, leucine-rich pentatricopeptide repeat-containing protein (LRPPRC), which is specifically overexpressed in the most lethal subtype of lung adenocarcinoma. Targeted LRPPRC protein knockdown is a promising therapeutic strategy for the undruggable LUAD (lung adenocarcinoma). Nevertheless, LRPPRC is mainly located in mitochondria and degraded by protease. Current protein knockdown approaches, such as proteolysis-targeting chimeras (PROTACs), have limitations in their applications to the proteins degraded through proteasome-independent ways. Here, we designed an aptamer-assisted high-throughput method to screen small molecules that could bind to LRPPRC directly, disrupt the interaction of LRPPRC with its stabilizing chaperon protein, and lead to LRPPRC degradation by mitochondrial protease. The screened compound, gossypolacetic acid (GAA), is an old medicine that can accomplish the new function for targeted LRPPRC knockdown. It showed significant antitumor effects even with the LRPPRC-positive patient-derived tumor xenograft (PDX) model. This work not only extended the application of aptamers to screen small-molecule inhibitors for the undruggable lung cancers, but more importantly provided a new strategy to develop protein knockdown methods beyond the proteasome system.

HIF1α promotes prostate cancer progression by increasing ATG5 expression

Prostate cancer (PCa) is the most frequently diagnosed cancer among men. However, the major modifiable risk factors for PCa are poorly known and its specific mechanism of progression remains unclear. Here we reported that, in prostate cancer cells, the autophagy level was elevated under hypoxic condition, as well as the mRNA and protein level of ATG5, which is an important gene related to autophagy. Furthermore, we found HIF1α could directly bind to the promoter of ATG5 and promote the expression of ATG5 on transcriptional level by luciferase assay and ChIP assay. Intriguingly, overexpression of HIF1α by HIF1α-M could increase tumor size and the effect could be abolished by knockdown ATG5 by si-ATG5 in BALB/cA-nu/nu nude mice. Importantly, HIF1α could also promote the metastasis of PC-3 cells by upregulating the ATG5 and autophagy level and knockdown ATG5 and inhibition autophagy both could abolish the effect of overexpression of HIF1α on the migration of PC-3 cells. Taken together, our results, for the first time, proved that HIF1α could promote the proliferation and migration of PC-3 cells by direct upregulating ATG5 and autophagy level in PC-3 prostate cancer cells. Our findings not only provide new perspective for the relationship between hypoxia and autophagy, but also add new potential therapeutic regimens for the treatment of prostate cancers.

Spermidine Confers Liver Protection by Enhancing NRF2 Signaling Through a MAP1S-Mediated Noncanonical Mechanism

Spermidine (SPD), a naturally occurring polyamine, has been recognized as a caloric restriction mimetic that confers health benefits, presumably by inducing autophagy. Recent studies have reported that oral administration of SPD protects against liver fibrosis and hepatocarcinogenesis through activation of microtubule associated protein 1S (MAP1S)-mediated autophagy. Nuclear factor (erythroid-derived 2)-like 2 (NRF2) is a transcription factor that mediates cellular protection by maintaining the cell's redox, metabolic, and proteostatic balance. In this study, we demonstrate that SPD is a noncanonical NRF2 inducer, and that MAP1S is a component of this noncanonical pathway of NRF2 activation. Mechanistically, MAP1S induces NRF2 signaling through two parallel mechanisms, both resulting in NRF2 stabilization: (1) MAP1S competes with Kelch-like ECH-associated protein 1 (KEAP1) for NRF2 binding through an ETGE motif, and (2) MAP1S accelerates p62-dependent degradation of KEAP1 by the autophagy pathway. We further demonstrate that SPD confers liver protection by enhancing NRF2 signaling. The importance of both NRF2 and p62-dependent autophagy in SPD-mediated liver protection was confirmed using a carbon tetrachloride-induced liver fibrosis model in wild-type, Nrf2-/- , p62-/- and Nrf2-/- ;p62-/- mice, as the protective effect of SPD was significantly reduced in NRF2 or p62 single knockout mice, and completely abolished in the double knockout mice. Conclusion: Our results demonstrate the pivotal role of NRF2 in mediating the health benefit of SPD, particularly in the context of liver pathologies.

Role of Autophagy in Renal Cancer

Autophagy is a highly conserved catabolic process with critical functions in maintenance of cellular homeostasis under normal growth conditions and in preservation of cell viability under stress. The role of autophagy in cancer is dual-sided. Autophagy-deficient cells are often more tumorigenic than their wild type counterparts in association with DNA damage accumulation, oxidative stress. At the same time, autophagy is a major cell survival mechanism. In recent years, it has been well demonstrated that autophagy may have relation with renal cell carcinoma (RCC). This review focuses on the research progress in relation between autophagy and RCC and the pharmacologic manipulation of autophagy for RCC treatment.

LRPPRC: A Multifunctional Protein Involved in Energy Metabolism and Human Disease

The pentatricopeptide repeat (PPR) family plays a major role in RNA stability, regulation, processing, splicing, translation, and editing. Leucine-rich PPR-motif-containing protein (LRPPRC), a member of the PPR family, is a known gene mutation that causes Leigh syndrome French-Canadian. Recently, growing evidence has pointed out that LRPPRC dysregulation is related to various diseases ranging from tumors to viral infections. This review presents available published data on the LRPPRC protein function and its role in tumors and other diseases. As a multi-functional protein, LRPPRC regulates a myriad of biological processes, including energy metabolism and maturation and the export of nuclear mRNA. Overexpression of LRPPRC has been observed in various human tumors and is associated with poor prognosis. Downregulation of LRPPRC inhibits growth and invasion, induces apoptosis, and overcomes drug resistance in tumor cells. In addition, LRPPRC plays a potential role in Parkinson's disease, neurofibromatosis 1, viral infections, and venous thromboembolism. Further investigating these new functions of LRPPRC should provide novel opportunities for a better understanding of its pathological role in diseases from tumors to viral infections and as a potential biomarker and molecular target for disease treatment.

Reversibility of castration resistance status after Radium-223 dichloride treatment: clinical evidence and review of the literature

In the history of prostate cancer, some of the patients progressed to castration-resistant prostate cancer (CRPC) stage and, although new drugs and treatment protocols have been introduced, CRPC presents poor prognosis. This review is focused on biological mechanisms, underlying CRPC described in scientific literature in order to explain the reversion of resistance to castration. We present the case of a 73-year-old man, affected by bone metastatic CRPC, early treated with Radium-223 with a complete response. After 15 months from Radium-223 treatment, prostate-specific antigen increased with radiological progression. Androgen deprivation therapy was again performed and was effective, despite previous CRPC condition and no known mechanisms that may explain the reversion of this condition. Therefore, to our knowledge, he is the unique described case of the reversion of resistance to castration. Nevertheless, promising aspects may be lack of intrametastatic production of androgen or the suppression of bypass androgen receptor signaling pathways. Furthermore, the cytotoxic action of Radium-223 on cancer stem cell (CSC), due to surrounding clones with high-bone turnover, or the immune response that underlying the abscopal effect, may also modulate the reversion of CRPC after Radium-223. If confirmed by multicenter trials, the reversion of CRPC may impact on the management of prostate cancer.

Cytoplasmic SQSTM1/ P62 Accumulation Predicates a Poor Prognosis in Patients with Malignant Tumor

Aims: SQSTM1/p62, as an autophagy marker, is a key molecule involved in the autophagy process. Recent studies have demonstrated that p62 has a close relationship with tumorigenesis and progression, but the impact of p62 on patients' survival has not been comprehensively understood. Therefore, we conducted this study to assess the expression level of p62 in tumor cells and the prognostic role of p62 expression in various malignant tumors. Methods: We searched PubMed, PubMed Central (PMC), Embase, Ovid and Web of Science databases and identified 30 eligible studies containing 14,072 patients to include in the meta-analysis. The p62 mRNA and protein expression profiles in various tumor tissues and normal tissues were presented according to the Human Protein Atlas (HPA) and the Gene Expression Profiling Interactive Analysis (GEPIA). We also tested the association between p62 mRNA level and patients' survival based on the Cancer Genome Atlas (TCGA) and the Human Protein Atlas (HPA) databases. Results: The expression levels of p62 mRNA and protein varied in different tissues. The p62 proteins were elevated and mainly located in the cytoplasm in some types of tumor compared with the normal tissues. The pooled results indicated that p62 overexpression in tumor tissues was associated with a worse prognosis. In the subgroup analysis, a significant relationship was observed between cytoplasmic p62 accumulation and both overall survival (HR 1.53, 95% CI: 1.03-2.27, P < 0.05) and disease-specific survival (HR 1.60, 95% CI: 1.15-2.24, P < 0.01). The relationship between p62 and worse survival was more evident in early stage tumors. P62 mRNA expression had no significant effect on the patient's survival except of liver cancer. Conclusions: The findings of this meta-analysis highlight the role of p62 as a useful prognostic biomarker for some types of tumor according to different clinicopathologic features, which may contribute to the selection of effective treatment methods for different malignant tumors.

High levels of glioma tumor suppressor candidate region gene 1 predicts a poor prognosis for prostate cancer

Glioma tumor suppressor candidate region gene 1 (GLTSCR1) is associated with the progression of oligodendroglioma. However, there has been little study of GLTSCR1 in prostate cancer. In the present study, the association between the expression of GLTSCR1, and the progression and prognosis of tumors in patients with prostate cancer was assessed. An immunohistochemical analysis was performed using a human tissue microarray for GLTSCR1 at the protein expression level and the immunostaining results were evaluated against clinical variables of patients with prostate cancer. Subsequently, The Cancer Genome Atlas (TCGA) was used to validate the analysis results at the mRNA level and to study the prognostic value of GLTSCR1 in prostate cancer. Immunohistochemistry and TCGA data analysis revealed that GLTSCR1 expression in the prostate cancer tissues was significantly higher than that in the benign prostate tissues (immunoreactivity score, P=0.015; mRNA levels: cancer, 447.7±6.45 vs. benign, 343.5±4.21; P<0.001). Additionally, the increased GLTSCR1 protein expression was associated with certain clinical variables in the prostate cancer tissues, including advanced clinical stage (P<0.001), enhanced tumor invasion (P=0.003), lymph node metastasis (P=0.003) and distant metastasis (P=0.001). TCGA data revealed similar results, demonstrating that the upregulation of GLTSCR1 mRNA expression was associated with the Gleason score (P<0.001), enhanced tumor invasion (P=0.011), lymph node metastasis (P=0.001) and distant metastasis (P=0.002). Furthermore, Kaplan-Meier analysis suggested that among all patients, high GLTSCR1 expression indicated a decreased overall survival (P=0.028) and biochemical recurrence (BCR)-free survival (P=0.004), compared with patients with low GLTSCR1 expression. Finally, multivariate analysis revealed that the expression of GLTSCR1 was an independent predictor of poor BCR-free survival (P=0.049). The present study suggested that the increased expression of GLTSCR1 was associated with the progression of prostate cancer. Furthermore, GLTSCR1 may be a novel biomarker that is able to predict the clinical outcome in prostate cancer patients.

Elevated expression of PTCD3 correlates with tumor progression and predicts poor prognosis in patients with prostate cancer

Pentatricopeptide repeat domain protein 3 (PTCD3) is a mitochondrial RNA-binding protein that serves a role in mitochondrial translation. PTCD3 was originally reported as an oncogene that is involved in breast cancer and lymphoma. However, the expression and function of PTCD3 in prostate cancer (PCa) are unknown. Therefore, the aim of the present study was to investigate the expression of PTCD3 and its clinical significance in PCa. Immunohistochemistry and dataset analyses revealed that PTCD3 protein expression levels were enhanced in human PCa tissues and mouse PCa models. PTCD3 expression levels were positively correlated with advanced PCa pathological grade and clinical stage. Additionally, PTCD3 mRNA expression was positively correlated with tissue malignancy, high Gleason score and distant metastasis in The Cancer Genome Atlas dataset. Kaplan-Meier analysis revealed that high PTCD3 levels can predict the increased biochemical recurrence (BCR)-free survival in all patients with or without metastasis. The overexpression of PTCD3 could be used as an independent prognostic marker of poor BCR-free survival. Immunofluorescence and western blot analysis in human PCa cell lines further confirmed that PTCD3 levels were associated with the hormone independence of PCa. Therefore, the present study revealed that PTCD3 levels may serve as a novel biomarker for PCa prognosis.

Metastatic prostate cancer-associated P62 inhibits autophagy flux and promotes epithelial to mesenchymal transition by sustaining the level of HDAC6

BACKGROUND

P62 (also named sequestosome-1, SQSTM1) is involved in autophagy regulation through multiple pathways. It interacts with autophagosomes-associated LC3-II and ubiquitinated protein aggregates to engulf the aggregates in autophagosomes, interacts with HDAC6 to inhibit its deacetylase activity to maintain the levels of acetylated α-tubulin and stabilities of microtubules to enhance autophagosome trafficking, and regulates autophagy initiation and cell survival. We performed immunohistochemistry staining of P62 in prostate tissues from prostate cancer patients and found that levels of P62 in patients with prostate adenocarcinomas (PCA) are significantly higher than those in patients with benign prostate hyperplasia (BPH). High levels of P62 predict high tumor grade and high intensity of metastasis.

METHODS

We created prostate cancer cell lines stably overexpressing P62 and then suppress the expression of P62 in the cell line stably overexpressing P62 with CRISPR technology. Cell proliferation assay with crystal violet, cell migration assay, cell invasion assay, Western blot analysis, and confocal fluorescent microscopy were conducted to test the impact of altered levels of P62 on the growth, migration, invasion, epithelial-to-mesenchymal transition, autophagy flux, HDAC6 activity, and microtubular acetylation of cancer cells.

RESULTS

P62 increased the levels of HDAC6 and reduced the acetylation of α-tubulin and the stability of microtubules. Consequently, high levels of P62 caused a promotion of epithelial-to-mesenchymal transition in addition to an impairment of autophagy flux, and further led to an enhancement of proliferation, migration, and invasion of prostate cancer cells.

CONCLUSION

P62 promotes metastasis of PCA by sustaining the level of HDAC6 to inhibit autophagy and promote epithelial-to-mesenchymal transition.

Matrine inhibits the progression of prostate cancer by promoting expression of GADD45B

BACKGROUND

Matrine is a naturally occurring alkaloid extracted from the Chinese herb Sophora flavescens. It has been demonstrated to exhibit antiproliferative properties, promote apoptosis, and inhibit cell invasion in a number of cancer cell lines by modulating the NF-κB pathway to downregulate the expression of MMP2 and MM9. It has also been shown to improve the efficacy of chemotherapy when it is combined with other chemotherapy drugs. However, the therapeutic potential of matrine for prostate cancer needs to be further studied.

METHODS

We analyzed KEGG pathways of differential gene expression between matrine-treated and untreated prostate cancer cell lines and identified GADD45B as one of major target genes of matrine based on its role in apoptosis and prognosis value for prostate cancer patients in TCGA database. We further analyzed the expression of GADD45B protein in a tissue microarray and mRNA in TCGA database, and tested the synergistic impacts of matrine and GADD45B overexpression on proliferation, apoptosis, migration and invasion of prostate cancer cell DU145.

RESULTS

Matrine promoted the expression of GADD45B, a tumor suppressive gene that is involved in the regulation of cell cycle, DNA damage repair, cell survival, aging, apoptosis and other cellular processes through p38/JNK, ROS-GADD45B-p38, or other signal pathways. Although GADD45B is elevated in prostate cancer tissues, levels of GADD45B in prostate tumor tissues are reduced at late stage of tumor invasion, and higher levels of GADD45B predict better survivals of prostate cancer patients.

CONCLUSIONS

Matrine may be used to treat prostate cancer patients to increase the levels of GADD45B to inhibit tumor invasion and improve patient survivals.

Molecular and cellular mechanisms of castration resistant prostate cancer

With increases in the mortality rate and number of patients with prostate cancer (PCa), PCa, particularly the advanced and metastatic disease, has been the focus of a number of studies globally. Over the past seven decades, androgen deprivation therapy has been the primary therapeutic option for patients with advanced PCa; however, the majority of patients developed a poor prognosis stage of castration resistant prostate cancer (CRPC), which eventually led to mortality. Due to CRPC being incurable, laboratory investigations and clinical studies focusing on CRPC have been conducted worldwide. Clarification of the molecular pathways that may lead to CRPC is important for discovering novel therapeutic strategies to delay or reverse the progression of disease. A sustained androgen receptor (AR) signal is still regarded as the main cause of CRPC. Increasing number of studies have proposed different potential mechanisms that cause CRPC, and this has led to the development of novel agents targeting the AR-dependent pathway or AR-independent signaling. In the present review, the major underlying mechanisms causing CRPC, including several major categories of AR-dependent mechanisms, AR bypass signaling, AR-independent mechanisms and other important hypotheses (including the functions of autophagy, PCa stem cell and microRNAs in CRPC progression), are summarized with retrospective pre-clinical or clinical trials to guide future research and therapy.

The prognostic value of p62 in solid tumor patients: a meta-analysis

p62, as a scaffolding/adaptor protein, is involved in multiple physiological processes include inflammation, autophagy and mitosis. However, the influence of p62 in cancer patients has not been comprehensively investigated. Moreover, the prognostic value of p62 for the survival of patients with solid tumors remains controversial. In this present meta-analysis, twenty suitable articles were identified from PubMed, EMBASE and Web of Science, Nature databases, including 4271 patients. A random-effect or fixed-effect model was adopted to correlate p62 expression with different outcome measured in entire tumors. Combined with results of hazard ratios (HRs) and 95% confidence intervals (CIs), we concluded that higher expression of p62 is associated with poorer overall survival (OS) (HR: 2.22, 95% CI: 1.82–2.71, P < 0.05), disease-free survival (DFS) (HR = 2.48, 95% CI: 1.78–3.46, P < 0.05) and even certain clinicopathological parameters, such as lymph node metastasis (RR = 1.21, 95% CI: 1.06–1.37) and clinical stages (RR = 1.27, 95% CI: 1.12–1.45), in cancer patients. Consequently, our data showed that p62 might be an effective poor prognostic factor for patients with various solid tumors.

Identification of TMEM208 and PQLC2 as reference genes for normalizing mRNA expression in colorectal cancer treated with aspirin

Numerous evidences indicate that aspirin usage causes a significant reduction in colorectal cancer. However, the molecular mechanisms about aspirin preventing colon cancer are largely unknown. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) is a most frequently used method to identify the target molecules regulated by certain compound. However, this method needs stable internal reference genes to analyze the expression change of the targets. In this study, the transcriptional stabilities of several traditional reference genes were evaluated in colon cancer cells treated with aspirin, and also, the suitable internal reference genes were screened by using a microarray and were further identified by using the geNorm and NormFinder softwares, and then were validated in more cell lines and xenografts. We have showed that three traditional internal reference genes, β-actin, GAPDH and α-tubulin, are not suitable for studying gene transcription in colon cancer cells treated with aspirin, and we have identified and validated TMEM208 and PQLC2 as the ideal internal reference genes for detecting the molecular targets of aspirin in colon cancer in vitro and in vivo. This study reveals stable internal reference genes for studying the target genes of aspirin in colon cancer, which will contribute to identify the molecular mechanism behind aspirin preventing colon cancer.

Mitochondrion-associated protein peroxiredoxin 3 promotes benign prostatic hyperplasia through autophagy suppression and pyroptosis activation

Benign prostatic hyperplasia (BPH) is one of the most common diseases in the senior men and age plays an important role in the initiation and development of BPH. Mammalian cells primarily use the autophagy-lysosome system to degrade misfolded/aggregated proteins and dysfunctional organelles such as mitochondria and suppress pyroptosis, a type of cell death that stimulates inflammatory responses and growth of other cells around. Peroxiredoxin 3 (PRDX3) is the only mitochondrion-associated member of peroxiredoxin family enzymes that exert their protective antioxidant role in cells through their peroxidase activity. We hypothesized that PRDX3 may inhibit autophagy to activate pyroptosis to induce growth of prostatic epithelial cells. Here we show that PRDX3 maintained the integrity of mitochondria and its depletion led to an enhancement of oxidative stresses. PRDX3-associated and PRDX3-free mitochondria co-existed in the same cells. PRDX3 expressed at higher levels in prostatic epithelial cells in prostate tissues from BPH patients and BPH-representative cell line than in prostate tissues from healthy donors and a cell line representing normal epithelial cells. PRDX3 suppressed autophagy flux and activated pyroptosis to induce inflammatory responses and stimulate the over-growth of prostate tissues. Therefore, higher levels of PDRX3 in prostatic epithelial cells may promote the initiation and development of BPH through autophagy inhibition and pyroptosis activation.

Spermidine Prolongs Lifespan and Prevents Liver Fibrosis and Hepatocellular Carcinoma by Activating MAP1S-Mediated Autophagy

Liver fibrosis and hepatocellular carcinoma (HCC) have worldwide impact but continue to lack safe, low cost, and effective treatments. In this study, we show how the simple polyamine spermidine can relieve cancer cell defects in autophagy, which trigger oxidative stress-induced cell death and promote liver fibrosis and HCC. We found that the autophagic marker protein LC3 interacted with the microtubule-associated protein MAP1S, which positively regulated autophagy flux in cells. MAP1S stability was regulated in turn by its interaction with the histone deacetylase HDAC4. Notably, MAP1S-deficient mice exhibited a 20% reduction in median survival and developed severe liver fibrosis and HCC under stress. Wild-type mice or cells treated with spermidine exhibited a relative increase in MAP1S stability and autophagy signaling via depletion of cytosolic HDAC4. Extending recent evidence that orally administered spermidine can extend lifespan in mice, we determined that life extension of up to 25% can be produced by lifelong administration, which also reduced liver fibrosis and HCC foci as induced by chemical insults. Genetic investigations established that these observed impacts of oral spermidine administration relied upon MAP1S-mediated autophagy. Our findings offer a preclinical proof of concept for the administration of oral spermidine to prevent liver fibrosis and HCC and potentially extend lifespan. Cancer Res; 77(11); 2938-51. ©2017 AACR.

Fast clearance of lipid droplets through MAP1S-activated autophagy suppresses clear cell renal cell carcinomas and promotes patient survival

Clear cell renal cell carcinoma (ccRCC) is composed of cells whose cytoplasm filled with lipid droplets, subcellular organelles coated with adipocyte differentiation-related protein (ADFP) for the storage of triacylglycerol converted from excess free fatty acids. Mammalian cells primarily use the autophagy-lysosome system to degrade misfolded/aggregated proteins and dysfunctional organelles such as lipid droplets. MAP1S (originally named C19ORF5) is an autophagy activator and promotes the biogenesis and degradation of autophagosomes. Previously, we reported that MAP1S suppresses hepatocellular carcinogenesis in a mouse model and promoted the survival of patients with prostate adenocarcinomas by increasing the degradation of aggregated proteins and dysfunctional mitochondria. Here we show that a suppression of MAP1S in renal cells causes an impairment of autophagic clearance of lipid droplets. In contrast, an overexpression of MAP1S causes an activation of autophagy flux and a reduction of lipid droplets so less DNA double strand breakage is induced. The levels of MAP1S in normal renal cells are dramatically higher than those in the ccRCC tissues and cell lines derived from renal cell carcinomas. High levels of MAP1S are associated with a reduced malignancy and metastasis of ccRCC and predict a better survival of ccRCC patients. Therefore, autophagy defects in the degradation of lipid droplets triggered by the MAP1S deficiency may enhance the initiation and development of ccRCC and reduce the survival of ccRCC patients.

Elevated levels of epithelial cell transforming sequence 2 predicts poor prognosis for prostate cancer

Epithelial cell transforming sequence 2 (Ect2) was originally reported as an oncogene that is involved in several types of human cancers. However, little is known about its expression and function in prostate cancer. Immunohistochemical staining for Ect2 was performed on a human tissue microarray. The staining intensity was analyzed in association with clinical pathological parameters such as Gleason score, pathological grade, clinical stage, tumor invasion, lymph node and distant metastasis. Furthermore, we repeated such analysis and investigated the prognostic value of Ect2 using the TCGA (The Cancer Genome Atlas) Dataset. Our immunohistochemical results showed that the expression levels of Ect2 protein were enhanced in human prostate cancer tissues. There existed positive correlations between the expression levels of Ect2 and several clinicopathological parameters, including advanced clinical stage, enhanced tumor invasion and lymph node metastasis. Similarly, we found that the expression levels of Ect2 were positively related to Gleason score, tumor invasion, lymph node metastasis and high distant metastasis in the TCGA Dataset. Kaplan-Meier analysis revealed that lower levels of Ect2 mRNA predicted higher overall survivals and biochemical recurrence (BCR)-free survivals in all patients or non-metastatic patients. Multivariate analysis by Cox regression showed that the expression of Ect2 could be an independent prognostic marker of poor BCR-free survivals. Therefore, levels of Ect2 may serve as a novel marker for the diagnosis or prognosis of prostate cancer.

Elevated levels of autophagy-related marker ULK1 and mitochondrion-associated autophagy inhibitor LRPPRC are associated with biochemical progression and overall survival after androgen deprivation therapy in patients with metastatic prostate cancer

AIM

To evaluate the expression levels and prognostic significance of autophagy-related markers, UNC-51-like kinase1 (ULK1), Beclin1, microtubule-associated protein light chain 3 (LC3), autophagy-related gene 5 (ATG5) and mitochondrion-associated autophagy inhibitor, LRPPRC, in patients with metastatic prostate cancer (PCa) after androgen deprivation therapy (ADT).

METHODS

Expressions of ULK1, Beclin1, LC3, ATG5 and LRPPRC were assessed by immunohistochemical examination in 198 patients with metastatic PCa who were receiving ADT (goserelin and bicalutamide).

RESULTS

High expression levels of LRPPRC and ULK1were significantly associated with Gleason score, serum prostate-specific antigen (PSA) levels, PSA levels after ADT and number of metastatic sites. High expression of ULK1 in patients with concomitant high expression of LRPPRC was significantly associated with multiple metastases, shorter biochemical progression (BCP)-free survival and shorter overall survival (OS). ULK1 expression, LRPPRC expression, Gleason score, PSA levels after ADT and number of metastatic sites were independently associated with shorter BCP-free survival and OS on multivariate analysis. Furthermore, two-year BCP rate of patients with ≥3 risk factors was found to be significantly higher as compared with that of patients with ≤1 and 2 risk factors. Three-year OS rate in patients with ≥3 risk factors was significantly lower than that of those with ≤1 and 2 risk factors.

CONCLUSIONS

High expression of ULK1 concomitant with high expression of LRPPRC may serve as useful markers for shorter BCP-free survival and OS in patients with metastatic PCa after ADT.

Defects in MAP1S-mediated autophagy turnover of fibronectin cause renal fibrosis

Excessive deposition of extracellular matrix proteins in renal tissues causes renal fibrosis and renal function failure. Mammalian cells primarily use the autophagy-lysosome system to degrade misfolded/aggregated proteins and dysfunctional organelles. MAP1S is an autophagy activator and promotes the biogenesis and degradation of autophagosomes. Previously, we reported that MAP1S suppresses hepatocellular carcinogenesis in a mouse model and predicts a better prognosis in patients suffering from clear cell renal cell carcinomas. Furthermore, we have characterized that MAP1S enhances the turnover of fibronectin, and mice overexpressing LC3 but with MAP1S deleted accumulate fibronectin and develop liver fibrosis because of the synergistic impact of LC3-induced over-synthesis of fibronectin and MAP1S depletion-caused impairment of fibronectin degradation. Here we show that a suppression of MAP1S in renal cells caused an impairment of autophagy clearance of fibronectin and an activation of pyroptosis. Depletion of MAP1S in mice leads to an accumulation of fibrosis-related proteins and the development of renal fibrosis in aged mice. The levels of MAP1S were dramatically reduced and levels of fibronectin were greatly elevated in renal fibrotic tissues from patients diagnosed as renal atrophy and renal failure. Therefore, MAP1S deficiency may cause the accumulation of fibronectin and the development of renal fibrosis.

Defects in MAP1S-mediated autophagy cause reduction in mouse lifespans especially when fibronectin is overexpressed

Autophagy is a cellular process that executes the turnover of dysfunctional organelles and misfolded or abnormally aggregated proteins. Microtubule‐associated protein MAP1S interacts with autophagy marker LC3 and positively regulates autophagy flux. LC3 binds with fibronectinmRNA and facilitates its translation. The synthesized fibronectin protein is exported to cell surface to initiate the assembly of fibronectin extracellular matrix. Fibronectin is degraded in lysosomes after it is engulfed into cytosol via endocytosis. Here, we show that defects in MAP1S‐mediated autophagy trigger oxidative stress, sinusoidal dilation, and lifespan reduction. Overexpression of LC3 in wild‐type mice increases the levels of fibronectin and γ‐H₂AX, a marker of DNA double‐strand breakage. LC3‐induced fibronectin is efficiently degraded in lysosomes to maintain a balance of fibronectin levels in wild‐type mice so that the mice live a normal term of lifespan. In the LC3 transgenic mice with MAP1S deleted, LC3 enhances the synthesis of fibronectin but the MAP1S depletion causes an impairment of the lysosomal degradation of fibronectin. The accumulation of fibronectin protein promotes liver fibrosis, induces an accumulation of cell population at the G0/G1 stage, and further intensifies oxidative stress and sinusoidal dilatation. The LC3‐induced overexpression of fibronectin imposes stresses on MAP1S‐deficient mice and dramatically reduces their lifespans. Therefore, MAP1S‐mediated autophagy plays an important role in maintaining mouse lifespan especially in the presence of extra amount of fibronectin.

Transforming Growth Factor TGFβ Increases Levels of Microtubule-Associated Protein MAP1S and Autophagy Flux in Pancreatic Ductal Adenocarcinomas

Background and Aim

Autophagy is a cellular process to regulate the turnover of misfolded/aggregated proteins or dysfunctional organelles such as damaged mitochondria. Microtubule-associated protein MAP1S (originally named C19ORF5) is a widely-distributed homologue of neuronal-specific MAP1A and MAP1B with which autophagy marker light chain 3 (LC3) was originally co-purified. MAP1S bridges autophagic components with microtubules and mitochondria through LC3 and positively regulates autophagy flux from autophagosomal biogenesis to degradation. The MAP1S-mediated autophagy suppresses tumorigenesis as suggested in a mouse liver cancer model and in prostate cancer patients. The TGFβ signaling pathway plays a central role in pancreatic tumorigenesis, and high levels of TGFβ suggest a tumor suppressive function and predict a better survival for some patients with resectable pancreatic ductal adenocarcinoma. In this study, we try to understand the relationship between TGFβ and MAP1S-mediated autophagy in pancreatic ductal adenocarcinoma.

Methods

We collected the tumor and its adjacent normal tissues from 33 randomly selected patients of pancreatic ductal adenocarcinomas to test the association between TGFβ and autophagy markers MAP1S and LC3. Then we tested the cause and effect relation between TGFβ and autophagy markers in cultured pancreatic cancer cell lines.

Results

Here we show that levels of TGFβ and autophagy markers MAP1S and LC3 are dramatically elevated in tumor tissues from patients with pancreatic ductal adenocarcinomas. TGFβ increases levels of MAP1S protein and enhances autophagy flux.

Conclusion

TGFβ may suppress the development of pancreatic ductal adenocarcinomas by enhancing MAP1S-mediated autophagy.

Prognostic role of vascular endothelial growth factor in prostate cancer: a systematic review and meta-analysis

The objective of this study was to perform a meta-analysis and literature review on the predictive role of vascular endothelial growth factor (VEGF) in prostate cancer. A detailed literature search was performed using PubMed and Embase databases for related research publications written in English. Methodological quality of the studies was also evaluated. Data was collected from studies comparing overall survival (OS), progression-free survival (PFS), disease-free survival (DFS), biomedical failure (BF) and cancer-specific survival (CSS) in patients with elevated VEGF levels and those having lower levels. The hazard ratio (HR) and its 95% confidence interval (CI) were used to assess the strength of associations. A total of 12 studies (n = 1,737) were included in this meta-analysis (4 for OS, 3 for CSS, 2 for DFS, 4 for BF, and 4 for PFS). For OS, DFS and PFS, the pooled HR for VEGF was not statistically significant at 1.30 (95% CI, 0.74-2.29), 0.80 (95% CI, 0.57-1.13) and 1.04 (95% CI, 0.93-1.16), respectively. However, for CSS and BF, the pooled HR was 2.32 (95% CI, 1.20-4.46) and 1.30 (95% CI, 1.06-1.59), respectively. Our results demonstrate that VEGF may have a critical prognostic value in patients with prostatic cancer.

The viral restriction factor tetherin prevents leucine-rich pentatricopeptide repeat-containing protein (LRPPRC) from association with beclin 1 and B-cell CLL/lymphoma 2 (Bcl-2) and enhances autophagy and mitophagy

Tetherin has been characterized as a key factor that restricts viral particles such as HIV and hepatitis C virus on plasma membranes, acts as a ligand of the immunoglobulin-like transcript 7 (ILT7) receptor in tumor cells, and suppresses antiviral innate immune responses mediated by human plasmacytoid dendritic cells. However, the normal cellular function of Tetherin without viral infection is unknown. Here we show that Tetherin not only serves as a substrate of autophagy but itself regulates the initiation of autophagy. Tetherin interacts with the autophagy/mitophagy suppressor LRPPRC and prevents LRPPRC from forming a ternary complex with Beclin 1 and Bcl-2 so that Beclin 1 is released to bind with PI3KCIII (class III PI3K) to activate the initiation of autophagy. Suppression of Tetherin leads to impairment of autophagy, whereas overexpression of Tetherin causes activation of autophagy. Under mitophagic stress, Tetherin is concentrated on mitochondria engulfed in autophagosomes. Tetherin plays a general role in the degradation of autophagosomes containing not only the symbiotic mitochondria but also, possibly, the infected virus. Therefore, Tetherin may enhance autophagy and mitophagy to suppress tumorigenesis, enhance innate immune responses, or prevent T cell apoptosis or pyroptosis.