Altered energy metabolism is a hallmark of tumors aiming at supplying necessary nutrients for tumorigenesis and development. These redirected metabolic pathways associated with carbohydrate, lipid ...and amino acid are orchestrated not only by carcinogenic proteins but by non-coding RNAs. Among them, circular RNA (circRNA), as a kind of novel identified non-coding RNAs, has become the focus of attention. Through binding with corresponding microRNAs or directly contacting proteins, circRNA plays a primarily important role in regulating cellular metabolism. Herein, we analyze the emerging findings and select circRNAs contributing to mutant glycolysis, lipogenesis and lipolysis, glutam inolysis, and oxidative respiration to deepen the understanding about the cancer metabolic regulatory network. In addition, we also discuss the possibility of circRNAs exerting their functions via exosomes and cancer stem cells. Owing to their unique structures and wide impacts, circRNAs may help reap huge fruits in developing clinical treatments targeting cancer metabolism.
The differential expression of microRNAs (miRNAs) in plasma of pancreatic cancer (PC) patients may act as a diagnostic biomarker. A four-stage study was performed to identify plasma miRNAs with ...potential in detecting PC. Exiqon panels (20 PC vs. 10 normal controls (NCs)) were applied in the screening phase to obtain miRNA profiling. The identified miRNAs were further assessed in the training (40 PC vs. 40 NCs) and testing stages (112 PC vs. 116 NCs) with qRT-PCR assays. A six-miRNA signature including up-regulated miR-122-5p, miR-125b-5p, miR-192-5p, miR-193b-3p, miR-221-3p and miR-27b-3p was identified. The signature could accurately discriminate PC patients from NCs with areas under the receiver operating characteristic curve of 0.848, 0.833 and 0.937 for the training, testing and the external validation stage (41 PC vs. 50 NCs), respectively. The multivariate Cox regression analyses showed that down-regulated plasma miR-125b-5p could predict worse OS independent from late tumor stage and high CA19-9. All the six miRNAs except miR-122-5p showed high expression levels in PC tissues than those in matched normal tissues. MiR-122-5p and miR-193b-3p were up-regulated, while miR-221-3p was down-regulated in plasma exosomes from PC patients. Bioinformatics analysis demonstrated that the miRNAs might involve in several molecular pathways closely related with PC such as p53 signaling pathway, pancreatic cancer, TGF-beta signaling pathway and so on. In conclusion, we identified a six-miRNA signature in plasma which could act as a non-invasive biomarker in diagnosis and prognosis of PC. Plasma miR-125b-5p might act as an independent biomarker in predicting OS of PC patients.
•Gases of the giant field are mainly derived from the Sinian rocks.•Gas reservoirs of the field are mainly within the Sinian strata.•Gases of the field formed mainly from oil-cracking.•Gases of the ...field have extremely high dryness ratios.•Gases of the field suffered medium-level thermochemical sulfate reduction (TSR).
An estimated trillions of cubic meters of natural gas have recently been discovered in the Sinian dolomite reservoirs in the Sichuan Basin, China. The 20–26m thick reservoirs were found in deep structural–lithologic traps of 5000–5500m deep. The Sinian gas is thought to have been derived mainly from the Sinian source rocks, and partly from the Cambrian source rocks. The gas is thermally matured, with a dryness ratio (C1/∑C1–4) of 0.997–0.9998, C2H6 content <0.2%, and H2S content of 0.5–2.75%. The stable carbon isotope compositions (δ13C) of CH4 and C2H6 are similar in all the reservoirs, with values of −33.5‰ to −31.5‰ and −36.0‰ to −27.0‰ (PDB), respectively. The Sinian gas reservoirs are believed to have been accumulated by the following processes: initial paleo-oil accumulated during the Silurian–Devonian; gas accumulation after oil cracking of the paleo-oil accumulations during the Jurassic–Early Cretaceous; and the current gas accumulations formed by paleo-gas remigration and adjustment since the Late Cretaceous. This new gas accumulation model is consistent with large-scale gas accumulations for deeply buried paleocratonic basins worldwide, in which the source rocks initially underwent thermal oil generation from kerogen, followed by gas generation via oil cracking. The gas discovery in the Sinian dolomite reservoirs has led to a new wave of hydrocarbon gas exploration in the ancient cratonic basin containing the mostly thermally matured source rocks in China. We conducted a series of geochemical analyses of the H2S in the gases. The sulfur isotope compositions (δ34S) of gypsum, H2S, and secondary pyrite sampled from the Sinian Dengying Formation showed that H2S was generated by a moderate thermochemical sulfate reduction (TSR) during the Jurassic–Early Cretaceous periods. TSR was terminated by the depletion of SO42− in the formation water, resulting in a modest H2S content of 5–10% in the natural gases. Because the dolomites are rich in cations, a large quantity of H2S may have been bound to form metal sulfides. We infer that H2S contents of 0.8–10% are present widely in the deeply buried Sinian reservoirs. Therefore, measures should be taken to prevent H2S-related accidents during gas exploration in the deep strata.
MicroRNAs (miRNAs) are short noncoding RNA molecules, which posttranscriptionally regulate genes expression and play crucial roles in diverse biological processes, such as development, ...differentiation, apoptosis and proliferation. Here, we investigated the possible role of miRNAs in the development of multidrug resistance (MDR) in human gastric and lung cancer cell lines. We found that miR‐181b was downregulated in both multidrug‐resistant human gastric cancer cell line SGC7901/vincristine (VCR) and multidrug‐resistant human lung cancer cell line A549/cisplatin (CDDP), and the downregulation of miR‐181b in SGC7901/VCR and A549/CDDP cells was concurrent with the upregulation of BCL2 protein, compared with the parental SGC7901 and A549 cell lines, respectively. In vitro drug sensitivity assay demonstrated that overexpression of miR‐181b sensitized SGC7901/VCR and A549/CDDP cells to anticancer drugs, respectively. The luciferase activity of a BCL2 3′‐untranslated region‐based reporter construct in SGC7901/VCR and A549/CDDP cells suggests that a new target site in the 3′UTR of BCL2 of the mature miR‐181s (miR‐181a, miR‐181b, miR‐181c and miR‐181d) was found. Enforced miR‐181b expression reduced BCL2 protein level and sensitized SGC7901/VCR and A549/CDDP cells to VCR‐induced and CDDP‐induced apoptosis, respectively. Taken together, our findings suggest that miR‐181b could play a role in the development of MDR in both gastric and lung cancer cell lines, at least in part, by modulation of apoptosis via targeting BCL2.
Recently, more and more studies investigated the association of inflammation parameters such as the Platelet Lymphocyte Ratio (PLR) and the prognosis of various cancers. However, the prognostic role ...of PLR in cancer remains controversial.
We conducted a meta-analysis of published studies to evaluate the prognostic value of PLR in various cancers. In order to investigate the association between PLR and overall survival (OS), the hazard ratio (HR) and its 95% confidence interval (CI) were calculated.
A total of 13,964 patients from 26 studies were included in the analysis. The summary results showed that elevated PLR was a negative predictor for OS with HR of 1.60 (95%CI: 1.35-1.90; Pheterogeneity <0.001). Subgroup analysis revealed that increased PLR was a negative prognostic marker in patients with gastric cancer (HR = 1.35, 95%CI: 0.80-2.25, Pheterogeneity = 0.011), colorectal cancer (HR = 1.65, 95%CI: 1.33-2.05, Pheterogeneity = 0.995), hepatocellular carcinoma (HR = 3.07, 95% CI: 2.04-4.62, Pheterogeneity = 0.133), ovarian cancer (HR = 1.57, 95%CI: 1.07-2.31, Pheterogeneity = 0.641) and non-small cell lung cancer (NSCLC) (HR = 1.85, 95% CI: 1.42-2.41, Pheterogeneity = 0.451) except for pancreatic cancer (HR = 1.00, 95%CI: 0.92-1.09, Pheterogeneity = 0.388).
The meta-analysis demonstrated that PLR could act as a significant biomarker in the prognosis of various cancers.
The Meso-Neoproterozoic period, sometimes referred to as the ‘boring billion’ or ‘Earth's middle age’, spans the interval between the formation of the Columbia and Rodina supercontinents. It is ...regarded as a stable era of the Earth. However, from a global perspective, there are many intensive events of mafic volcanism, dyke intrusions and formation of rift basins recorded in different cratons during this period. This paper focuses on rift basins that developed in three cratons in China (North China, South China and Tarim cratons), because large-scale primary gasfields, as one of the deep resources, have been discovered recently in rocks of Meso-Neoproterozoic age. The formation mechanisms and tectonic settings of these rift basins as the targets of Deep Earth are discussed, based on the restoration of global positions of the three cratons by pre-existing paleomagnetic data and plate reconstruction. We recognise that the rift basins of the North China Craton are related to extrusion tectonics in the southwest Ordos Block or are pull-apart basins along the northern and southern sides of the Ordos Block. The rift basins of the South China Craton are derived from mantle lithospheric delamination of the Jiangnan Orogen in the eastern South China Craton or subduction retreat and backarc opening in the western South China Craton, respectively. The rift basins of the Tarim Craton originated from the backarc opening along the margin of the Supercontinent Rodinia.
The Anyue Sinian–Cambrian giant gas field was discovered in central paleo-uplift in the Sichuan Basin in 2013, which is a structural-lithological gas reservoir, with 779.9 km2 proven gas-bearing area ...and 4 403.8×108 m3 proven geological reserves in the Cambrian Longwangmiao Formation in Moxi Block, and the discovery implies it possesses trillion-cubic-meter reserves in the Sinian. Cambrian Formations in Sichuan Basin. The main understandings achieved are as follows: (1) Sinian–Cambrian sedimentary filling sequences and division evidence are redetermined; (2) During Late Sinian and Early Cambrian, “Deyang–Anyue” paleo-taphrogenic trough was successively developed and controlled the distribution of source rocks in the Lower-Cambrian, characterized by 20–160 m source rock thickness, TOC 1.7%–3.6% and Ro 2.0%–3.5%; (3) Carbonate edge platform occurred in the Sinian Dengying Formation, and carbonate gentle slope platform occurred in the Longwangmiao Formation, with large-scale grain beach near the synsedimentary paleo- uplift; (4) Two types of gas-bearing reservoir, i.e. carbonate fracture-vug type in the Sinian Dengying Formation and dolomite pore type in the Cambrian Longwangmiao Formation, and superposition transformation of penecontemporaneous dolomitization and supergene karst formed high porosity-permeability reservoirs, with 3%–4% porosity and (1–6)×10−3 μm2 permeability in the Sinian Dengying Formation, and 4%–5% porosity and (1–5)×10−3 μm2 permeability in the Cambrian Longwangmiao Formation; (5) Large paleo-oil pool occurred in the core of the paleo-uplift during late Hercynian—Indosinian, with over 5 000 km2 and (48–63)×108 t oil resources, and then in the Yanshanian period, in-situ crude oil cracked to generate gas and dispersive liquid hydrocarbons in deep slope cracked to generate gas, both of which provide sufficient gas for the giant gas field; (6) The formation and retention of the giant gas field is mainly controlled by paleo-taphrogenic trough, paleo-platform, paleo-oil pool cracking gas and paleo-uplift jointly; (7) Total gas resources of the Sinian–Cambrian giant gas field are preliminarily predicted to be about 5×1012 m3, and the paleo-uplift and its slope, southern Sichuan Basin depression and deep formations of the high and steep structure belt in east Sichuan, are key exploration plays. The discovery of deep Anyue Sinian–Cambrian giant primay oil-cracking gas field in the Sichuan Basin, is the first in global ancient strata exploration, which is of great inspiration for extension of oil & gas discoveries for global middle-deep formations from Lower Paleozoic to Middle–Upper Proterozoic strata.
The discovery of the giant Anyue gas field in Sichuan Basin gives petroleum explorers confidence to find oil and gas in Proterozoic to Cambrian. Based on the reconstruction of tectonic setting and ...the analysis of major geological events in Mesoproterozoic-Neoproterozoic, the petroleum geological conditions of Proterozoic to Cambrian are discussed in this paper from three aspects, i.e. source rocks, reservoir conditions, and the type and efficiency of play. It is found that lower organisms boomed in the interglacial epoch from Mesoproterozoic-Neoproterozoic to Eopaleozoic when the organic matters concentrated and high quality source rocks formed. Sinian-Cambrian microbial rock and grain-stone banks overlapped with multiple-period constructive digenesis may form large-scale reservoir rocks. However, because of the anoxic event and weak weathering effect in Eopaleozoic-Mesoproterozoic, the reservoirs are generally poor in quality, and only the reservoirs that suffered weathering and leaching may have the opportunity to form dissolution-reconstructed reservoirs. There are large rifts formed during Mesoproterozoic-Neoproterozoic in Huabei Craton, Yangtze Craton, and Tarim Craton in China, and definitely source rocks in the rifts, while whether there are favorite source-reservoir plays depends on circumstance. The existence of Sinian-Cambrian effective play has been proved in Upper Yangtze area. The effectiveness of source-reservoir plays in Huabei area depends on two factors: (1) the effectiveness of secondary play formed by Proterozoic source rock and Paleozoic, Mesozoic, Cenozoic reservoir rocks; (2) the matching between reservoirs formed by reconstruction from Mesoproterozoic- Neoproterozoic to Eopaleozoic and the inner hydrocarbon kitchens with late hydrocarbon generation. As for Tarim Basin, the time of Proterozoic and the original basin should be analyzed before the evaluation of the effective play. To sum up, Proterozoic to Cambrian in the three craton basins in China is a potential exploration formation, which deserves further investigation and research.
In order to understand redox variations and organic matter accumulation on the Yangtze carbonate platform during the Late Ediacaran–Early Cambrian, petrological and geochemical studies of several ...wells were carried out in this work. Our data suggest that depositional environments were dominated by oxidizing bottom water conditions during the late Ediacaran, and evolved to anoxic conditions, triggered by blooms of microbial organisms in surface waters during the earliest Cambrian. Subsequently, massive release of H2S derived from both anaerobic recycling of organic matter and, probably, hydrothermal venting promoted a sulfidic ocean. The discovery of a Ni-Mo sulfide ore layer in the basal Cambrian implies that such a sulfidic condition spread onto the Yangtze carbonate platform interior during the late Cambrian Stage 2. Further, transgressive flooding led to widespread black shale deposition and persistently anoxic conditions, as indicated by geochemical proxies. During the late Ediacaran to earliest Cambrian, local and widespread phosphogenesis indicates that organic matter accumulation was intimately associated with microbial (especially cyanobacterial) blooms driven by phosphorus cycling. The organic matter accumulations in early Cambrian black shales, however, were in connection with anoxic bottom water conditions and intermittent replenishment of recycled organic phosphorus to surface waters.
•Redox variations and OM accumulation on the Yangtze carbonate platform during the E-C transition were studied.•A sulfidic condition spread onto the Yangtze carbonate platform interior during the late Cambrian Stage 2.•Local and widespread phosphogenesis occurred during the Late Ediacaran to earliest Cambrian.•OM accumulations of Early Cambrian shales were in connection with persistently anoxic conditions and intermittent replenishment of recycled organic P to surface waters.
Many countries and regions in the world have obtained industrial oil flow in the Meso-Neoproterozoic sedimentary strata and formed commercial exploitation in recent years. The development horizon of ...high-quality source rocks in the Proterozoic in North China can be compared with the international, indicating that the Meso-Neoproterozoic in North China has great exploration potential. The sedimentary characteristics of typical aulacogen in multiple cratons in the Meso-Neoproterozoic North China Craton are compared and studied by using field outcrop data, drilling data and analysis and test data, aiming to provide sedimentary support for the prediction of oil and gas distribution and evaluation of exploration field in the Meso-Neoproterozoic in this area. The results show that there are four sedimentary systems in the study area, including Marine clastic rock sedimentary system, Marine carbonate sedimentary system, Marine-continental transitional facies sedimentary system and glacial sedimentary system. They are divided into seven sedimentary facies types: barrier coastal facies, non-barrier coast facies, shallow shelf facies, carbonate platform facies, reef facies, fan delta facies and glacial facies, and further divided into 15 subfacies and 21 microfacies. On this basis, the Meso-Neoproterozoic sedimentary filling sequences of two typical aulacogens, Yanliao and Xiong 'er, in the study area are clarified, showing that the formation time of each sedimentary filling sequence stage of different aulacogens is different, and the rock characteristics, lithology combination, lithologic structure, contact relationship, vertical sequence and sedimentary facies assemblage of the same sedimentary filling sequence stage are obviously different. The filling characteristics of the two aulacogens completely record the geological events related to the breakup of the Colombian supercontinent.
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