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Escherichia coli (E. coli) is commonly utilized as a vehicle for anti-tumor therapy due to its unique tumor-targeting capabilities and ease of engineering modification. To further explore the role of E. coli in tumor treatment, we consider that E. coli outer membrane vesicles (E. coli-OMVs) play a crucial role in the therapeutic process. Firstly, E. coli-OMVs were isolated and partially purified by filtration and ultracentrifugation, and were characterized using techniques such as nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM) and Western Blot (WB). The obtained extracellular nanoparticles, containing OMVs, were found to inhibited the growth of CT26 tumor in mice, while the expression of Bax protein was increased and the expression of Bcl-2 protein decreased. In vitro experiments showed that E. coli-OMVs entered CT26 cells and inhibited cell proliferation, invasion and migration. In addition, in the presence of E. coli-OMVs, we observed an increase in apoptosis rate and a decrease in the ratio of Bcl-2/Bax. These data indicate that E. coli-OMVs inhibits the growth of CT26 colon cancer by inducing apoptosis of CT26 cells. These findings propose E. coli-OMVs as a promising therapeutic drug for colorectal cancer (CRC), providing robust support for further research in related fields. [ABSTRACT FROM AUTHOR]

The spring Pacific meridional mode (PMM) is an important precursor of El Niño–Southern Oscillation (ENSO). However, recent studies reported that only about half of the spring PMM events were followed by ENSO events. This study examines the role of internal climate variability in modulating the impact of PMM on ENSO using 100-member ensemble simulations of the Max Planck Institute Earth System Model (MPI-ESM). The relationship between spring PMM and following winter ENSO shows a large spread among the 100 members. The variation of spring Aleutian low (AL) intensity is identified to be an important factor modulating the PMM–ENSO relation. The spring AL affects the PMM–ENSO relationship by modifying PMM-generated low-level zonal wind anomalies over the tropical western Pacific. The strengthening of the spring AL is accompanied by westerly wind anomalies over the midlatitude northwestern Pacific, leading to sea surface temperature (SST) cooling there via an enhancement of upward surface heat flux. This results in increased meridional SST gradient and leads to northerly wind anomalies over the subtropical northwestern Pacific, which turn to surface westerly wind anomalies after reaching the equatorial western Pacific due to the conservation of potential vorticity. Thus, the low-level westerly (easterly) wind anomalies over the tropical western Pacific associated with the positive (negative) spring PMM were strengthened (weakened), which further contributes to an enhanced (a weakened) PMM–ENSO relation. The mechanism for the modulation of the AL on the spring PMM–ENSO relationship is verified by a set of AGCM simulations. This study suggests that the condition of the spring AL should be considered when predicting ENSO on the basis of the PMM. Significance Statement: Spring Pacific meridional mode (PMM) is a predictor of ENSO, but not all spring PMM events are accompanied by the occurrence of ENSO events. This study aims to explore the influence of internal climate variability on the relationship between spring PMM and following ENSO. It is revealed that the Aleutian low exerts a crucial modulation on the spring PMM–ENSO relationship. The underlying physical mechanisms for the impact of the Aleutian low on the relationship between spring PMM and ENSO are further examined. The results of this study have important implications for improving the prediction of ENSO. [ABSTRACT FROM AUTHOR]