Ultrasound-Assisted CRISPRi-Exosome for Epigenetic Modification of α-Synuclein Gene in a Mouse Model of Parkinson's Disease.

Currently, there is a lack of effective treatment for Parkinson's disease (PD). In PD patients, aberrant methylation of SNCA (α-synuclein gene) has been reported and may be a potential therapeutic target. In this study, we established an epigenetic regulation platform based on an exosomal CRISPR intervention system. With the assist of focused ultrasound (FUS) opening the blood-brain barrier, engineered exosomes carrying RVG (rabies viral glycoprotein) targeting peptide, sgRNA (single guide RNA), and dCas9-DNMT3A (named RVG-CRISPRi-Exo) were efficiently delivered into the brain lesions and induced specific methylation of SNCA. In vivo, FUS combined with RVG-CRISPRi-Exo significantly improved motor performance, balance coordination, and neurosensitivity in PD mice, greatly down-regulated the elevation of α-synuclein (α-syn) caused by modeling, rescued cell apoptosis, and alleviated the progression of PD in mice. [18F]-FP-DTBZ imaging suggested that the synaptic function of the nigrostriatal pathway could be restored, which was conducive to the control of motor behavior in PD mice. Pyrosequencing results showed that RVG-CRISPRi-Exo could methylate CpG at specific sites of SNCA, and this fine-tuned editing achieved good therapeutic effects in PD model mice. In vitro, RVG-CRISPRi-Exo down-regulated SNCA transcripts and α-syn expression and relieved neuronal cell damage. Collectively, our findings provide a proof-of-principle for the development of targeted brain nanodelivery based on engineered exosomes and provide insights into epigenetic regulation of brain diseases.

Genome sequences of Colletotrichum eleusines and C. echinochloae: two pathogens from Poaceae weeds.

We present two whole-genome sequences of Colletotrichum strains which were isolated from Eleusine indica and Echinochloa crus-galli using Nanopore and Illumina technologies, as part of screening for potential mycoherbicide. The genome sequences will provide important genetic information and will be useful for further research into secondary metabolites of Colletotrichum.

Extracellular Vehicles from Commensal Skin Malassezia restricta Inhibit Staphylococcus aureus Proliferation and Biofilm Formation.

The colonizing microbiota on the body surface play a crucial role in barrier function. Staphylococcus aureus (S. aureus) is a significant contributor to skin infection, and the utilization of colonization resistance of skin commensal microorganisms to counteract the invasion of pathogens is a viable approach. However, most studies on colonization resistance have focused on skin bacteria, with limited research on the resistance of skin fungal communities to pathogenic bacteria. Extracellular vehicles (EVs) play an important role in the colonization of microbial niches and the interaction between distinct strains. This paper explores the impact of Malassezia restricta (M. restricta), the fungus that dominates the normal healthy skin microbiota, on the proliferation of S. aureus by examining the distribution disparities between the two microorganisms. Based on the extraction of EVs, the bacterial growth curve, and biofilm formation, it was determined that the EVs of M. restricta effectively suppressed the growth and biofilm formation of S. aureus. The presence of diverse metabolites was identified as the primary factor responsible for the growth inhibition of S. aureus, specifically in relation to glycerol phospholipid metabolism, ABC transport, and arginine synthesis. These findings offer valuable experimental evidence for understanding microbial symbiosis and interactions within healthy skin.

Moringa oleifera leaf improves meat quality by modulating intestinal microbes in white feather broilers.

Moringa oleifera addition to animal diets can improve the growth performance, intestinal health, and immunity of animals, without adverse effects. We investigated the effects of Moringa oleifera on the growth performance, meat quality, and intestinal health of broilers. Moringa oleifera and fermented Moringa oleifera could improve the flesh color and breast muscle tenderness of broilers (p < 0.05). The contents of essential amino acids, unsaturated fatty acids, ΣMUFA, P/S and n-3 ratio in breast muscle of broilers were dose-increased, and the effect of fermented Moringa oleifera was better. Moringa oleifera and fermented Moringa oleifera regulated chicken flavor metabolism by increasing the relative abundance and Short-chain fatty acid (SCFA) contents of Bacteroides, Spirillum, and lactic acid bacteria. Overall, supplementation with 1 % fermented Moringa oleifera can significantly increase essential amino acid and unsaturated fatty acid contents in broilers and participate in the synthesis and transformation of amino acids and fatty acids regulated by beneficial bacteria.

Nanomedicine-mediated regulated cell death in cancer immunotherapy.

Immunotherapy has attracted widespread attention in cancer treatment and has achieved considerable success in the clinical treatment of some tumors, but it has a low response rate in most tumors. To achieve sufficient activation of the immune response, significant efforts using nanotechnology have been made to enhance cancer immune response. In recent years, the induction of various regulated cell death (RCD) has emerged as a potential antitumor immuno-strategy, including processes related to apoptosis, autophagy, necroptosis, pyroptosis, ferroptosis, and cuproptosis. In particular, damage-associated molecular patterns (DAMPs) released from the damaged membrane of dying cells act as in situ adjuvants to trigger antigen-specific immune responses by the exposure of an increased antigenicity. Thus, RCD-based immunotherapy offers a new approach for enhancing cancer treatment efficacy. Furthermore, incorporation with multimodal auxiliary therapies in cell death-based immunotherapy can trigger stronger immune responses, resulting in more efficient therapeutic outcome. This review discusses different RCD modalities and summarizes recent nanotechnology-mediated RCDs in cancer immunotherapy.

Cut to Disarm Plant Defence: A Unique Oviposition Behaviour in Rhynchites foveipennis (Coleoptera: Attelabidae).

Female weevils of the family Attelabidae (Coleoptera: Curculionoidea) possess a unique behaviour of partially cutting the branches connecting egg-bearing organs of their host plants during oviposition. However, the consequence of such behaviour remains unclear. Using Rhynchites foveipennis and its host pear (Pyrus pyrifolia), the present study tested the hypothesis that the oviposition behaviour could disarm the host plants' defence. We compared the survival rates, growth rates, and performance of eggs and larvae under two conditions: (1) the fruit stems were naturally damaged by the females before and after oviposition, and (2) the fruit stems were artificially protected from the females. When fruit stems were protected from female damage, the survival rates of eggs and larvae were only 21.3-32.6%, respectively; and the larval weight was 3.2-4.1 mg 30 days after laying eggs. When the fruit stems were damaged, the survival rates of eggs and larvae reached 86.1-94.0%, respectively; and the larval weight reached 73.0-74.9 mg 30 days after laying eggs. The contents of tannin and flavonoids in the pears did not change significantly along with the oviposition and larval feeding, but weevil eggs were crushed and killed by the callus in the pears. Once the stunted larvae in branch-growing pears were moved into the picked-off ones, the growth and development recovered. The findings indicate that the oviposition behaviour can significantly increase the survival of the offspring. Our study suggested that the oviposition behaviour of attelabid weevils is a strategy to overcome plant defence.

Colletotrichum echinochloae: A Potential Bioherbicide Agent for Control of Barnyardgrass (Echinochloa crus-galli (L.) Beauv.).

Barnyardgrass (Echinochloa crus-galli (L.) Beauv.) is one of the most troublesome weeds in transplanted and direct-seeded rice worldwide. To develop a strategy for the biocontrol of barnyardgrass, fungal isolates were recovered from barnyardgrass plants that exhibited signs of necrosis and wilt. An isolate B-48 with a high level of pathogenicity to barnyardgrass was identified after pathogenicity tests. From cultural and DNA sequence data, this strain was identified as Colletotrichum echinochloae. The inoculation of the barnyardgrass plant with C. echinochloae caused a significant reduction in fresh weight. The isolate B-48 was highly pathogenic to barnyardgrass at the three- to four-leaf stages. When inoculated at a concentration of 1 × 107 spores/mL, barnyardgrass could achieve a reduction in fresh weight of more than 50%. This strain was safe for rice and most plant species. The results of this study indicated that this strain could be a potential mycoherbicide for barnyardgrass control in paddy fields in the future.

Downregulated mitochondrial transcription factor A enhances mycoplasma infection to promote the metastasis of hepatocellular carcinoma.

Mycoplasma is widespread in various hosts and may cause various diseases in animals. Interestingly, the occurrence of mycoplasma infection was observed in many tumor types. However, the mechanism regulating its infection is far from clear. We unexpectedly found that the knockdown of mitochondrial transcription factor A (TFAM) remarkably enhanced mycoplasma infection in hepatocellular carcinoma (HCC) cells. More importantly, we found that mycoplasma infection facilitated by TFAM knockdown significantly promoted HCC cell metastasis. Mycoplasma infection was further found to be positively correlated with poor prognosis in patients with HCC. Mechanistically, the decreased TFAM expression upregulated the transcription factor Sp1 to increase the expression level of Annexin A2 (ANXA2), which was reported to interact with membrane protein of mycoplasma. Moreover, we found that mycoplasma infection enhanced by the TFAM downregulation promoted HCC migration and invasion by activating the nuclear factor-κB signaling pathway. The downregulation of TFAM enhanced mycoplasma infection in HCC cells and promoted HCC cell metastasis. Our study contributes to the understanding of the pathological role of mycoplasma infection and provides supporting evidence that targeting TFAM could be a potential strategy for the treatment of HCC with mycoplasma infection.

[Prediction of immune-related genes associated with prognosis in patients with hepatocellular carcinoma by bioinformatics methods].

Objective To establish a prognosis model using immune-related genes in hepatocellular carcinoma (HCC) patients, which could provide a theoretical foundation for HCC immunotherapy. Methods Immune-related genes were identified by differential expression analysis, and risk prognosis prediction models were established using univariate, multivariate Cox and Least absolute shrinkage and selection operator (LASSO) regression analysis. The predictive value of the prognostic model was evaluated using the concordance index (C-index), receiver operating characteristic curve (ROC curve), and calibration curve and decision curve. In addition, risk score was used to stratify patients to assess prognostic differences in patients at different risk levels. Results We identified 1403 immune-related genes, mainly involved in biological processes such as immune response, adaptive immune response, and immunoglobulin production, as well as pathways such as cytokine interactions, chemokine signaling pathways and allograft rejection. Univariate Cox analysis found that 53 immune-related genes were associated with prognosis, and eight prognostic immune-related genes cytochrome P450 1A2(CYP1A2), ficolin 3(FCN3), hepatoma derived growth factor-like 1(HDGFL1), lipocalin 2(LCN2), mitochondrially encoded cytochrome C oxidase II pseudogene 12(MTCO2P12), peptidyl arginine deiminase 3(PADI3) and regulator of G protein signaling 16(RGS16) were further screened by LASSO and multivariate Cox regression analysis. Subsequently, a prognostic nomogram based on risk score was established. The ROC curve, calibration curve and decision curve confirmed that the model has good discrimination, accuracy and clinical value. Furthermore, stratified analysis showed that patients with higher risk scores had poorer prognosis. Conclusion We establish a prognostic nomogram model using eight immune-related genes, which can reliably predict the prognosis of HCC patients.

Mutational profiling of mtDNA control region reveals tumor-specific evolutionary selection involved in mitochondrial dysfunction.

BACKGROUND: Mitochondrial DNA (mtDNA) mutations alter mitochondrial function in oxidative metabolism and play an important role in tumorigenesis. A series of studies have demonstrated that the mtDNA control region (mtCTR), which is essential for mtDNA replication and transcription, represents a mutational hotspot in human tumors. However, a comprehensive pan-cancer evolutionary pattern analysis of mtCTR mutations is urgently needed. METHODS: We generated a comprehensive combined dataset containing 10026 mtDNA somatic mutations from 4664 patients, covering 20 tumor types based on public and private next-generation sequencing data. FINDINGS: Our results demonstrated a significantly higher and much more variable mutation rate in mtCTR than in the coding region across different tumor types. Moreover, our data showed a remarkable distributional bias of tumor somatic mutations between the hypervariable segment (HVS) and non-HVS, with a significantly higher mutation density and average mutation sites in HVS. Importantly, the tumor-specific mutational pattern between mtCTR HVS and non-HVS was identified, which was classified into three evolutionary selection types (relaxed, moderate, and strict constraint types). Analysis of substitution patterns revealed that the prevalence of CH > TH in non-HVS greatly contributed to the mutational selection pattern of mtCTR across different tumor types. Furthermore, we found that the mutational pattern of mtCTR in the four tumor types was clearly associated with mitochondrial biogenesis, mitochondrial oxidative metabolism, and the overall survival of patients. INTERPRETATION: Our results suggest that somatic mutations in mtCTR may be shaped by tumor-specific selective pressure and are involved in tumorigenesis. FUNDINGS: National Natural Science Foundation of China [grants 82020108023, 81830070, 81872302], and Autonomous Project of State Key Laboratory of Cancer Biology, China [grants CBSKL2019ZZ06, CBSKL2019ZZ27].

TFAM loss induces nuclear actin assembly upon mDia2 malonylation to promote liver cancer metastasis.

The mechanisms underlying cancer metastasis remain poorly understood. Here, we report that TFAM deficiency rapidly and stably induced spontaneous lung metastasis in mice with liver cancer. Interestingly, unexpected polymerization of nuclear actin was observed in TFAM-knockdown HCC cells when cytoskeleton was examined. Polymerization of nuclear actin is causally linked to the high-metastatic ability of HCC cells by modulating chromatin accessibility and coordinating the expression of genes associated with extracellular matrix remodeling, angiogenesis, and cell migration. Mechanistically, TFAM deficiency blocked the TCA cycle and increased the intracellular malonyl-CoA levels. Malonylation of mDia2, which drives actin assembly, promotes its nuclear translocation. Importantly, inhibition of malonyl-CoA production or nuclear actin polymerization significantly impeded the spread of HCC cells in mice. Moreover, TFAM was significantly downregulated in metastatic HCC tissues and was associated with overall survival and time to tumor recurrence of HCC patients. Taken together, our study connects mitochondria to the metastasis of human cancer via uncovered mitochondria-to-nucleus retrograde signaling, indicating that TFAM may serve as an effective target to block HCC metastasis.

Next-Generation Sequencing-Based Analysis of Urine Cell-Free mtDNA Reveals Aberrant Fragmentation and Mutation Profile in Cancer Patients.

BACKGROUND: Many studies have demonstrated the high efficacy of cell-free nuclear DNA in cancer diagnostics. Compared to nuclear DNA, mitochondrial DNA (mtDNA) exhibits distinct characteristics, including multiple copies per cell and higher mutation frequency. However, the potential applicability of cell-free mtDNA (cf-mtDNA) in plasma and urine remains poorly investigated. METHODS: Here, we comprehensively analyzed the fragmentomic and mutational characteristics of cf-mtDNA in urine and plasma samples from controls and cancer patients using next-generation sequencing. RESULTS: Compared to plasma cf-mtDNA, urine cf-mtDNA exhibited increased copy numbers and wider spread in fragment size distributions. Based on 2 independent animal models, urine cf-mtDNA originated predominantly from local shedding and transrenal excretion. Further analysis indicated an enhanced fragmentation of urine cf-mtDNA in renal cell carcinoma (RCC) and colorectal cancer (CRC) patients. Using the mtDNA sequence of peripheral blood mononuclear cells for reference, the mutant fragments were shorter than wild-type fragments in urine cf-mtDNA. Size selection of short urine cf-mtDNA fragments (<150 bp) significantly enhanced the somatic mutation detection. Our data revealed remarkably different base proportions of fragment ends between urine and plasma cf-mtDNA that also were associated with fragment size. Moreover, both RCC and CRC patients exhibited significantly higher T-end and lower A-end proportions in urine cf-mtDNA than controls. By integrating the fragmentomic and mutational features of urine cf-mtDNA, our nomogram model exhibited a robust efficacy for cancer diagnosis. CONCLUSIONS: Our proof-of-concept findings revealed aberrant fragmentation and mutation profiles of urine cf-mtDNA in cancer patients that have diagnostic potential.

mitoDataclean: A machine learning approach for the accurate identification of cross-contamination-derived tumor mitochondrial DNA mutations.

Next-generation sequencing (NGS) of mitochondrial DNA (mtDNA) has widespread applications in aging and cancer studies. However, cross-contamination of mtDNA constitutes a major concern. Previous methods for the detection of mtDNA contamination mainly focus on haplogroup-level phylogeny, but neglect haplotype-level differences, leading to limited sensitivity and accuracy. In our study, we present mitoDataclean, a random-forest-based machine learning package for accurate identification of cross-contamination, evaluation of contamination levels and detection of contamination-derived variants in mtDNA NGS data. Comprehensive optimization of mitoDataclean revealed that training simulation with mixtures of small haplogroup distance and low polymorphic difference was critical for optimal modeling. Compared to existing methods, mitoDataclean exhibited significantly improved sensitivity and accuracy for the detection of sample contamination in simulated data. In addition, mitoDataclean achieved area under the curve values of 0.91 and 0.97 for discerning genuine and contamination-derived mtDNA variants in a simulated Western dataset and private sequencing contamination data, respectively, suggesting that this tool may be applicable for different populations and samples with different sources of contamination. Finally, mitoDataclean was further evaluated in several private and public datasets and showed a robust ability for contamination detection. Altogether, our study demonstrates that mitoDataclean may be used for accurate detection of contaminated samples and contamination-derived variants in mtDNA NGS data.

Mitochondrial fragmentation is crucial for c-Myc-driven hepatoblastoma-like liver tumors.

Hepatoblastoma is the most common liver cancer in children, and the aggressive subtype often has a poor prognosis and lacks effective targeted therapy. Although aggressive hepatoblastoma (HB) is often accompanied by abnormally high expression of the transcription factor c-Myc, the underlying mechanism remains unclear. In this study, we found that mitochondrial fragmentation was enhanced by c-Myc overexpression in human aggressive HB tissues and was associated with poor prognosis. Then, a mouse model resembling human HB was established via hydrodynamic injection of c-Myc plasmids. We observed that liver-specific knockout of the mitochondrial fusion molecule MFN1 or overexpression of mitochondrial fission molecule DRP1 promoted the occurrence of c-Myc-driven liver cancer. In contrast, when MFN1 was overexpressed in the liver, tumor formation was delayed. In vitro experiments showed that c-Myc transcriptionally upregulated the expression of DRP1 and decreased MFN1 expression through upregulation of miR-373-3p. Moreover, enhanced mitochondrial fragmentation significantly promoted aerobic glycolysis and the proliferation of HB cells by significantly increasing reactive oxygen species (ROS) production and activating the RAC-alpha serine/threonine-protein kinase (AKT)/mammalian target of rapamycin (mTOR) and nuclear factor κB (NF-κB) pathways. Taken together, our results indicate that c-Myc-mediated mitochondrial fragmentation promotes the malignant transformation and progression of HB by activating ROS-mediated multi-oncogenic signaling.

Mitochondrial transcription factor A plays opposite roles in the initiation and progression of colitis-associated cancer.

BACKGROUND: Mitochondria are key regulators in cell proliferation and apoptosis. Alterations in mitochondrial function are closely associated with inflammation and tumorigenesis. This study aimed to investigate whether mitochondrial transcription factor A (TFAM), a key regulator of mitochondrial DNA transcription and replication, is involved in the initiation and progression of colitis-associated cancer (CAC). METHODS: TFAM expression was examined in tissue samples of inflammatory bowel diseases (IBD) and CAC by immunohistochemistry. Intestinal epithelial cell (IEC)-specific TFAM-knockout mice (TFAM△IEC ) and colorectal cancer (CRC) cells with TFAM knockdown or overexpression were used to evaluate the role of TFAM in colitis and the initiation and progression of CAC. The underlying mechanisms of TFAM were also explored by analyzing mitochondrial respiration function and biogenesis. RESULTS: The expression of TFAM was downregulated in active IBD and negatively associated with the disease activity. The downregulation of TFAM in IECs was induced by interleukin-6 in a signal transducer and activator of transcription 3 (STAT3)/miR-23b-dependent manner. In addition, TFAM knockout impaired IEC turnover to promote dextran sulfate sodium (DSS)-induced colitis in mice. Of note, TFAM knockout increased the susceptibility of mice to azoxymethane/DSS-induced CAC and TFAM overexpression protected mice from intestinal inflammation and colitis-associated tumorigenesis. By contrast, TFAM expression was upregulated in CAC tissues and contributed to cell growth. Furthermore, it was demonstrated that ß-catenin induced the upregulation of TFAM through c-Myc in CRC cells. Mechanistically, TFAM promoted the proliferation of both IECs and CRC cells by increasing mitochondrial biogenesis and activity. CONCLUSIONS: TFAM plays a dual role in the initiation and progression of CAC, providing a novel understanding of CAC pathogenesis.

AKAP1 Deficiency Attenuates Diet-Induced Obesity and Insulin Resistance by Promoting Fatty Acid Oxidation and Thermogenesis in Brown Adipocytes.

Altering the balance between energy intake and expenditure is a major strategy for treating obesity. Nonetheless, despite the progression in antiobesity drugs on appetite suppression, therapies aimed at increasing energy expenditure are limited. Here, knockout ofAKAP1, a signaling hub on outer mitochondrial membrane, renders mice resistant to diet-induced obesity.AKAP1 knockout significantly enhances energy expenditure and thermogenesis in brown adipose tissues (BATs) of obese mice. Restoring AKAP1 expression in BAT clearly reverses the beneficial antiobesity effect in AKAP1-/- mice. Mechanistically, AKAP1 remarkably decreases fatty acid ß-oxidation (FAO) by phosphorylating ACSL1 to inhibit its activity in a protein-kinase-A-dependent manner and thus inhibits thermogenesis in brown adipocytes. Importantly, AKAP1 peptide inhibitor effectively alleviates diet-induced obesity and insulin resistance. Altogether, the findings demonstrate that AKAP1 functions as a brake of FAO to promote diet-induced obesity, which may be used as a potential therapeutic target for obesity.

Akap1 deficiency exacerbates diabetic cardiomyopathy in mice by NDUFS1-mediated mitochondrial dysfunction and apoptosis.

AIMS/HYPOTHESIS: Diabetic cardiomyopathy, characterised by increased oxidative damage and mitochondrial dysfunction, contributes to the increased risk of heart failure in individuals with diabetes. Considering that A-kinase anchoring protein 121 (AKAP1) is localised in the mitochondrial outer membrane and plays key roles in the regulation of mitochondrial function, this study aimed to investigate the role of AKAP1 in diabetic cardiomyopathy and explore its underlying mechanisms. METHODS: Loss- and gain-of-function approaches were used to investigate the role of AKAP1 in diabetic cardiomyopathy. Streptozotocin (STZ) was injected into Akap1-knockout (Akap1-KO) mice and their wild-type (WT) littermates to induce diabetes. In addition, primary neonatal cardiomyocytes treated with high glucose were used as a cell model of diabetes. Cardiac function was assessed with echocardiography. Akap1 overexpression was conducted by injecting adeno-associated virus 9 carrying Akap1 (AAV9-Akap1). LC-MS/MS analysis and functional experiments were used to explore underlying molecular mechanisms. RESULTS: AKAP1 was downregulated in the hearts of STZ-induced diabetic mouse models. Akap1-KO significantly aggravated cardiac dysfunction in the STZ-treated diabetic mice when compared with WT diabetic littermates, as evidenced by the left ventricular ejection fraction (LVEF; STZ-treated WT mice [WT/STZ] vs STZ-treated Akap1-KO mice [KO/STZ], 51.6% vs 41.6%). Mechanistically, Akap1 deficiency impaired mitochondrial respiratory function characterised by reduced ATP production. Additionally, Akap1 deficiency increased cardiomyocyte apoptosis via enhanced mitochondrial reactive oxygen species (ROS) production. Furthermore, immunoprecipitation and mass spectrometry analysis indicated that AKAP1 interacted with the NADH-ubiquinone oxidoreductase 75 kDa subunit (NDUFS1). Specifically, Akap1 deficiency inhibited complex I activity by preventing translocation of NDUFS1 from the cytosol to mitochondria. Akap1 deficiency was also related to decreased ATP production and enhanced mitochondrial ROS-related apoptosis. In contrast, restoration of AKAP1 expression in the hearts of STZ-treated diabetic mice promoted translocation of NDUFS1 to mitochondria and alleviated diabetic cardiomyopathy in the LVEF (WT/STZ injected with adeno-associated virus carrying gfp [AAV9-gfp] vs WT/STZ AAV9-Akap1, 52.4% vs 59.6%; KO/STZ AAV9-gfp vs KO/STZ AAV9-Akap1, 42.2% vs 57.6%). CONCLUSIONS/INTERPRETATION: Our study provides the first evidence that Akap1 deficiency exacerbates diabetic cardiomyopathy by impeding mitochondrial translocation of NDUFS1 to induce mitochondrial dysfunction and cardiomyocyte apoptosis. Our findings suggest that Akap1 upregulation has therapeutic potential for myocardial injury in individuals with diabetes.

An eight-long non-coding RNA signature as a candidate prognostic biomarker for bladder cancer.

Backgroud: Bladder cancer (BLCA) is one of the most fatal types of cancer worldwide. However, there are limited methods for us to provide a prognostic prediction of BLCA patients. Therefore, we aimed at developing a lncRNA signature to improve the prognosis prediction of BLCA. RESULTS: An eight-lncRNA signature was significantly associated with recurrence free survival in BLCA patients from both discovery and validation groups. Furthermore, genes involved in the signature were enriched in extracellular matrix organization pathway. Finally, functional experiments demonstrated that six out of the eight lncRNAs significantly regulated the invasion of BLCA cells. METHOD: A total of 343 BLCA patients from The Cancer Genome Atlas (TCGA) were employed and randomly divided into training (n=172) and validating (n=171) groups. The lncRNA expression profiles of BLCA patients were screened and a risk-score formula were created and validated according to the Cox regression analysis. Next, WGCNA method was employed to cluster genes that highly correlated with the risk scores based on the profiling data of TCGA dataset and transwell assay was also performed to further investigate the role of these lncRNAs. CONCLUSIONS: Our results suggested that the eight-lncRNA signature was a candidate prognostic biomarker for predicting tumor recurrence of patients with BLCA.

Upregulation of mtSSB by interleukin-6 promotes cell growth through mitochondrial biogenesis-mediated telomerase activation in colorectal cancer.

It is now widely accepted that mitochondrial biogenesis is inhibited in most cancer cells. Interestingly, one of the possible exceptions is colorectal cancer (CRC), in which the content of mitochondria has been found to be higher than in normal colon mucosa. However, to date, the causes and effects of this phenomenon are still unclear. In the present study, we systematically investigated the functional role of mitochondrial single-strand DNA binding protein (mtSSB), a key molecule in the regulation of mitochondrial DNA (mtDNA) replication, in the mitochondrial biogenesis and CRC cell growth. Our results demonstrated that mtSSB was frequently upregulated in CRC tissues and that upregulated mtSSB was associated with poor prognosis in CRC patients. Furthermore, overexpression of mtSSB promoted CRC cell growth in vitro by regulating cell proliferation. The in vivo assay confirmed these results, indicating that the forced expression of mtSSB significantly increases the growth capacity of xenograft tumors. Mechanistically, the survival advantage conferred by mtSSB was primarily caused by increased mitochondrial biogenesis and subsequent ROS production, which induced telomerase reverse transcriptase (TERT) expression and telomere elongation via Akt/mTOR pathway in CRC cells. In addition, FOXP1, a member of the forkhead box family, was identified as a new transcription factor for mtSSB. Moreover, our results also demonstrate that proinflammatory IL-6/STAT3 signaling facilitates mtSSB expression and CRC cell proliferation via inducing FOXP1 expression. Collectively, our findings demonstrate that mtSSB induced by inflammation plays a critical role in the regulation of mitochondrial biogenesis, telomerase activation, and subsequent CRC proliferation, providing a strong evidence for mtSSB as drug target in CRC treatment.