Establishment of highly metastatic sublines and insights into telomerase expression during tumor metastasis using a microfluidic system.

Metastasis is an important hallmark of malignant tumors, and telomerase often exhibits high expression in these tumors. Monitoring the real-time dynamics of telomerase will provide valuable insights into its association with tumor metastasis. In this study, we described a microfluidic system for screening highly metastatic sublines based on differential cell invasiveness, investigated telomerase expression in the process of tumor metastasis and explored the genes and signaling pathways involved in tumor metastasis. Cells with different metastasis abilities were efficiently classified into different channels, and the fluorescence imaging visually demonstrates that cells with higher metastasis ability have stronger telomerase activity. In addition, we successfully established the high-metastasis-ability LoVo subline (named as LoVo-H) and low-metastasis-ability LoVo subline (named as LoVo-L) from the human colorectal cancer LoVo cell lines through only one round of selection using the system. The results show that the LoVo-H cells display superior proliferation and invasiveness compared to LoVo-L cells. Furthermore, 6776 differentially expressed genes of LoVo-H compared with LoVo-L were identified by transcriptome sequencing. The genes associated with telomerase activity, cell migration and the epithelial to mesenchymal transition were up-regulated in LoVo-H, and PI3K-Akt signaling pathway, extracellular matrix-receptor interaction and Rap1 signaling pathway were significantly enriched in LoVo-H. This microfluidic system is a highly effective tool for selecting highly metastatic sublines and the LoVo-H subline established through this system presents a promising model for tumor metastasis research. Furthermore, this work preliminarily reveals telomerase expression during tumor metastasis and provides a new strategy for studying tumor metastasis and cancer diagnosis.

Microplastics and Endocrine Disruptors in Typical Wastewater Treatment Plants in Megacity Shanghai.

The fast development of China's urbanization has led to a notable release of emerging pollutants, including microplastics (MPs) and endocrine disruptors (EDCs). Generally, these pollutants enter the coastal environment through the discharge of wastewater treatment plants (WWTPs) and finally threaten the organisms in the receiving waterbody. The study investigated the environmental behavior of MPs and EDCs in two typical WWTPs in one of the megacities in China, Shanghai. The abundance of MPs in the influent ranged from 321 to 976 items/L. Four shapes (films, fragments, fibers, and microbead) were found, while fibers and films dominated. Transparent (31-63%) and white (20-47%) MPs were more frequently observed, while polyethylene terephthalate, cellulose, and cellophane were the main polymetric materials. The size of the MPs fell between 15.8 µm and 2220 µm, and the smaller one (<500 µm) dominated. The removal efficiencies of the two WWTPs for MPs ranged from 64% to 92%, and both WWTPs performed better for large pieces of MPs (>500 µm). For EDCs, total concentrations in the influent were detected, ranging from 113 to 2780 ng/L. Two groups, including phenolic estrogens (PEs) and steroid estrogens (SEs), were detected, and PEs, especially bisphenol A (BPA), were the predominant individuals among the studied EDCs. Specifically, PEs ranged from 82.8 to 2637 ng/L, while SEs ranged from 27.3 to 143 ng/L. The removal efficiencies of the WWTPs for EDCs varied (82.8-100%) as well, possibly due to the different treatment compartments and contamination load in the influent. Seasonal variations for both MPs and EDCs were observed. Specifically, concentrations of MPs and EDCs in WWTPs influent were higher in the wet season, as well as the removal efficiency. Furthermore, there was a correlation observed between the concentrations of MPs and EDCs, suggesting that MPs and EDCs may originate from the same source and that EDCs released by MPs cannot be ignored during treatment. Finally, the study evaluated the environmental risk of the effluents. MPs led to a minor risk (Level I), while EDCs might lead to an adverse impact on algae (RQs = 0.0014-0.024) and fish (RQs = 3.4-30.2). In summary, WWTPs received considerable amounts of MPs and EDCs. Although the WWTPs removed the contaminants efficiently, the environmental risk of the effluent needs to be noted.

Lactate increases tumor malignancy by promoting tumor small extracellular vesicles production via the GPR81-cAMP-PKA-HIF-1α axis.

Lactate and tumor cell-derived extracellular vesicles (TEVs) both contribute to tumor progression. However, it is still unclear whether lactate can accelerate tumor development by directly promoting TEV production. Here, we show that lactate decreases intracellular cAMP levels and subsequent PKA activation via GPR81, which inhibits the PKA-induced ubiquitination of HIF-1α that causes degradation. Then, the HIF-1α-mediated transcription of Rab27a is enhanced, leading to increased TEV release. In this way, lactate promotes lung metastasis by murine melanoma. In addition, we show that serum lactate levels are positively correlated with serum EV levels and Rab27a and HIF-1α protein levels in the tumor tissues of lung cancer patients. Thus, our results reveal a novel mechanism underlying lactate-mediated tumor progression induced by TEVs and provide new strategies for tumor therapy.