Identification of characteristic metabolic panels for different stages of prostate cancer by 1H NMR-based metabolomics analysis.

BACKGROUND: Prostate cancer (PCa) is the second most prevalent cancer in males worldwide, yet detecting PCa and its metastases remains a major challenging task in clinical research setups. The present study aimed to characterize the metabolic changes underlying the PCa progression and investigate the efficacy of related metabolic panels for an accurate PCa assessment. METHODS: In the present study, 75 PCa subjects, 62 PCa patients with bone metastasis (PCaB), and 50 benign prostatic hyperplasia (BPH) patients were enrolled, and we performed a cross-sectional metabolomics analysis of serum samples collected from these subjects using a 1H nuclear magnetic resonance (NMR)-based metabolomics approach. RESULTS: Multivariate analysis revealed that BPH, PCa, and PCaB groups showed distinct metabolic divisions, while univariate statistics integrated with variable importance in the projection (VIP) scores identified a differential metabolite series, which included energy, amino acid, and ketone body metabolism. Herein, we identified a series of characteristic serum metabolic changes, including decreased trends of 3-HB and acetone as well as elevated trends of alanine in PCa patients compared with BPH subjects, while increased levels of 3-HB and acetone as well as decreased levels of alanine in PCaB patients compared with PCa. Additionally, our results also revealed the metabolic panels of discriminant metabolites coupled with the clinical parameters (age and body mass index) for discrimination between PCa and BPH, PCaB and BPH, PCaB and PCa achieved the AUC values of 0.828, 0.917, and 0.872, respectively. CONCLUSIONS: Overall, our study gave successful discrimination of BPH, PCa and PCaB, and we characterized the potential metabolic alterations involved in the PCa progression and its metastases, including 3-HB, acetone and alanine. The defined biomarker panels could be employed to aid in the diagnosis and classification of PCa in clinical practice.

Mitochondrial UQCC3 controls embryonic and tumor angiogenesis by regulating VEGF expression.

Mitochondria play important roles in angiogenesis. However, the mechanisms remain elusive. In this study, we found that mitochondrial ubiquinol-cytochrome c reductase complex assembly factor 3 (UQCC3) is a key regulator of angiogenesis. TALEN-mediated knockout of Uqcc3 in mice caused embryonic lethality at 9.5-10.5 days postcoitum, and vessel density was dramatically reduced. Similarly, knockout of uqcc3 in zebrafish induced lethality post-fertilization and impaired vascular development. Knockout of UQCC3 resulted in slower tumor growth and angiogenesis. Mechanistically, UQCC3 was upregulated under hypoxia, promoted reactive oxygen species (ROS) generation, enhanced HIF-1α stability and increased VEGF expression. Finally, higher expression of UQCC3 was associated with poor prognosis in multiple types tumors, implying a role for UQCC3 in tumor progression. In conclusion, our findings highlight the important contribution of UQCC3 to angiogenesis under both physiological and pathological conditions, indicating the potential of UQCC3 as a therapeutic target for cancer.

The inhibition of protein translation promotes tumor angiogenic switch.

The 'angiogenic switch' is critical for tumor progression. However, the pathological details and molecular mechanisms remain incompletely characterized. In this study, we established mammal xenografts in zebrafish to visually investigate the first vessel growth (angiogenic switch) in real-time, by inoculating tumor cells into the perivitelline space of live optically transparent Transgenic (flk1:EGFP) zebrafish larvae. Using this model, we found that hypoxia and hypoxia-inducible factor (HIF) signaling were unnecessary for the angiogenic switch, whereas vascular endothelial growth factor A gene (Vegfa) played a crucial role. Mechanistically, transcriptome analysis showed that the angiogenic switch was characterized by inhibition of translation, but not hypoxia. Phosphorylation of eukaryotic translation initiation factor 2 alpha (Eif2α) and the expression of Vegfa were increased in the angiogenic switch microtumors, and 3D tumor spheroids, and puromycin-treated tumor cells. Vegfa overexpression promoted early onset of the angiogenic switch, whereas Vegfa knockout prevented the first tumor vessel from sprouting. Pretreatment of tumor cells with puromycin promoted the angiogenic switch in vivo similarly to Vegfa overexpression, whereas Vegfa knockdown suppressed the increase. This study provides direc and dynamic in vivo evidences that inhibition of translation, but not hypoxia or HIF signaling promotes the angiogenic switch in tumor by increasing Vegfa transcription.

Eradication of large established tumors by drug-loaded bacterial particles via a neutrophil-mediated mechanism.

The treatment of large established tumors remains a significant challenge and is generally hampered by poor drug penetration and intrinsic drug resistance of tumor cells in the central tumor region. In the present study, we developed bacterial particles (BactPs) to deliver chemotherapeutics into the tumor mass by hijacking neutrophils as natural cell-based carriers. BactPs loaded with doxorubicin, 5-fluorosuracil, or paclitaxel induced significantly greater tumor regression than unconjugated drugs. This effect was mediated by the ability of BactPs to incorporate chemotherapeutics and serve as vascular disrupting agents that trigger innate host responses and recruit phagocytic neutrophils. Vascular disruption resulted in extensive cell death in the central areas of the tumor mass. Recruited neutrophils acted as natural cellular carriers to deliver engulfed BactPs, which ensured drug delivery into the tumor mass and cytotoxic effects in areas that are normally inaccessible to traditional chemotherapy. Thus, BactPs eradicate large established tumors by functioning as vascular disrupters and natural drug carriers for neutrophil-mediated chemotherapy.

Chronological in vivo imaging reveals endothelial inflammation prior to neutrophils accumulation and lipid deposition in HCD-fed zebrafish.

BACKGROUND AND AIMS: Hyperlipidemia-induced atherosclerosis is the major cause of heart attack and stroke in humans. However, pathological details and molecular mechanisms underlying early atherogenesis remain incompletely characterized. This study explored the early events of atherogenesis in a hypercholesterolemic zebrafish model in vivo. METHODS: We used transparent transgenic zebrafish larvae Tg(lysc:EGFP), Tg(mpx:EGFP), Tg(mpeg1:EGFP), Tg(flk1:EGFP) or Tg(lysc:EGFP/flk1:mCherry), together with fluorescently labeled control and high cholesterol diets (HCD), to dynamically investigate the early development of atherosclerosis with confocal in vivo. Endothelial cells with green fluorescence were sorted by fluorescence-activated cell sorting (FACS) to detect gene expression. Moreover, we treated hypercholesterolemic zebrafish model in vivo or human umbilical vein endothelial cells (HUVEC) in vitro with rosiglitazone, an agonist of peroxisome proliferator-activated receptor γ (PPARγ). RESULTS: We found that HCD-induced endothelial inflammation was an earlier pathological alteration than myeloid cells/neutrophils accumulation and lipid deposition in zebrafish vascular vessels of HCD-fed zebrafish. Endothelial inflammation was characterized by down-regulation of anti-inflammatory PPARγ and upregulation of pro-inflammatory tumor necrosis factor α (TNF-α) and interleukin-1ß (IL-1ß). Pharmacological treatment with rosiglitazone reversed the decrease in the expression of PPARγ and decreased expression of TNF-α and IL-1ß in HCD-fed zebrafish. Moreover, rosiglitazone ameliorated myeloid cells accumulation and lipid deposition in HCD-fed zebrafish in vivo. CONCLUSIONS: Hyperlipidemia-induced endothelial inflammation happens earlier than myeloid cell neutrophils accumulation in vascular vessels, and neutrophils accumulation is prior to lipid deposition during the initial stage of atherosclerosis. Early alleviation of inflammation induced by HCD would have a prophylactic effect for the initial development of atherosclerosis.