DNA polymerase iota promotes EMT and metastasis of esophageal squamous cell carcinoma by interacting with USP7 to stabilize HIF-1α.

Esophageal squamous cell carcinoma (ESCC) is one of the most lethal cancer types, with a low 5-year survival rate of ~20%. Our prior research has suggested that DNA Polymerase iota (Pol ι), a member of Y-family DNA polymerase, plays a crucial role in the invasion and metastasis of ESCC. However, the underlying mechanism is not well understood. In this study, we utilized ChIP-PCR and luciferase reporter assays to investigate the binding of HIF-1α to the promoter of the Pol ι gene. Transwell, wound healing, and mouse models were employed to assess the impact of Pol ι and HIF-1α on the motility of ESCC cells. Co-immunoprecipitation and Western blot were carried out to explore the interaction between Pol ι and HIF-1α, while qRT-PCR and Western blot were conducted to confirm the regulation of Pol ι and HIF-1α on their downstream targets. Our results demonstrate that HIF-1α activates the transcription of the Pol ι gene in ESCC cells under hypoxic conditions. Furthermore, the knockdown of Pol ι impeded HIF-1α-induced invasion and metastasis. Additionally, we found that Pol ι regulates the expression of genes involved in epithelial-mesenchymal transition (EMT) and initiates EMT through the stabilization of HIF-1α. Mechanistically, Pol ι maintains the protein stability of HIF-1α by recruiting USP7 to mediate the deubiquitination of HIF-1α, with the residues 446-578 of Pol being crucial for the interaction between Pol ι and USP7. Collectively, our findings unveil a novel feedforward molecular axis of HIF-1α- Pol ι -USP7 in ESCC that contributes to ESCC metastasis. Hence, our results present an attractive target for intervention in ESCC.

Polymerase iota (POLI) confers radioresistance of esophageal squamous cell carcinoma by regulating RAD51 stability and facilitating homologous recombination.

Radiotherapy resistance is an important and urgent challenge in the clinical management of esophageal squamous carcinoma (ESCC). However, the factors mediating the ESCC resistance to radiotherapy and its underlying molecular mechanisms are not fully clarified. Our previous studies have demonstrated the critical role of DNA polymerase iota (POLI) in ESCC development and progression, here, we aimed to investigate the involvement of POLI in ESCC radiotherapy resistance and elucidate the underlying molecular mechanism. We found that highly expressed POLI was correlated with shorter overall survival of ESCC patients received radiotherapy. Down-regulation of POLI sensitized ESCC to IR, prolonged γH2AX foci in nuclei and comet tails after IR. HR but not NHEJ repair is inhibited in POLI-deficient ESCC cells. POLI stabilizes RAD51 protein via competitively binding with and blocking the interaction between RAD51 and E3 ligase XIAP and XIAP-mediated ubiquitination. Furthermore, loss of POLI leads to the activation of GAS signaling. Our findings provide novel insight into the role of POLI in the development of radioresistance mediated by stabilizing RAD51 protein in ESCC.

[Forecasting of Emission Co-reduction of Greenhouse Gases and Pollutants for the Road Transport Sector in Lanzhou Based on the LEAP Model].

With the continuous increase in transportation activities, the transportation sector has become an important source of global greenhouse gases. In 2019, road vehicles accounted for nearly three-quarters of the CO2 emissions of the entire transportation sector and will be the key to achieving carbon peaks in the transportation sector. At the same time, air pollutants emitted by road vehicles are also one of the threats to the environment and human health. Based on the long-range energy alternatives planning system (LEAP) model, we constructed the baseline (BAU) scenario, low-carbon (LC) scenario, and enhanced low-carbon (ELC) scenario for the development of the road transport sector in Lanzhou from 2015 to 2040 and simulated energy consumption and emission co-reduction of greenhouse gases and pollutants under policies and measures. The results showed that the energy consumption and CO2 emissions of the LC scenario will peak in 2026, whereas those in the ELC scenario will peak in 2020. In these two scenarios, pollutant emissions such as NOx, CO, HC, PM2.5, and PM10 began to decline sharply between 2015 and 2017, and the downward trend will slow down gradually around 2023. Based on the feasibility of measures and the cost of abatement, the LC scenario can be used as a road vehicle carbon peak scenario in Lanzhou. In this scenario, the reduction rates of energy consumption, CO2, NOx, CO, HC, PM2.5, and PM10 emissions will reach -24.17%, -26.57%, -55.38%, -65.91%, -72.87%, -76.66%, and -77.18% compared with those under the BAU scenario by 2040. At present, the road vehicles in Lanzhou City should focus on structural optimization measures such as clean-energy use of public transportation, electrification of small passenger cars, and phasing out old cars, as well as vigorously promoting low-carbon travel and improving energy efficiency accompanying the development of automotive technology. These efforts will effectively control CO2 and pollutant emissions by road vehicles, and carbon peaks will be achieved as soon as possible. In addition, it is necessary to pay attention to the changes in vehicle types during the implementation of these measures, which most contribute CO2 and various pollutants, in order to make the measures more targeted by changing the number or the market share of new energy of focused vehicle types.

Research on PM2.5 concentration based on dissipative structure theory: a case study of Xi'an, China.

PM2.5 pollution has become a serious urban environmental problem, especially in developing countries with increasing urbanization. Understanding the proportion of PM2.5 generation sources has laid a foundation for better PM2.5 concentration reduction This paper used Point of Interesting (POI)data, building profile data of Xi'an, PM2.5 concentration and wind monitoring data of five provinces near Xi'an as the basic data. And this paper studied the spatial distribution of various buildings in Xi'an, the temporal and spatial distribution of PM2.5 in Xi'an and the five provinces, and found that the spatial distribution of PM2.5 concentration in Xi'an and the building distribution in Xi'an does not match. Based on this, a quantitative model of PM2.5 concentration in Xi'an, energy consumption, wind, and other factors is established through the qualitative and quantitative analysis of PM2.5 concentration in Xi'an. Entropy theory and dissipative structure theory are applied to analyze this phenomenon. The results show PM2.5 in Xi'an mainly comes from the spread of PM2.5 in the five provinces. The PM2.5 generated by energy consumption in Xi'an is not enough to cause serious PM2.5 pollution. And further suggestions on how to reduce PM2.5 concentration in Xi'an are put forward.