ROS impairs tumor vasculature normalization through an endocytosis effect of caveolae on extracellular SPARC

Human Umbilical Vein Endothelial Cells as a Versatile Cellular Model System in Diverse Experimental Paradigms: An Ultrastructural Perspective

Human umbilical vein endothelial cells (HUVECs) are primary cells isolated from the vein of an umbilical cord, extensively used in cardiovascular studies and medical research. These cells, retaining the characteristics of endothelial cells in vivo, serve as a valuable cellular model system for understanding vascular biology, endothelial dysfunction, pathophysiology of diseases such as atherosclerosis, and responses to different drugs or treatments. Transmission electron microscopy (TEM) has been a cornerstone in revealing the detailed architecture of multiple cellular model systems including HUVECs, allowing researchers to visualize subcellular organelles, membrane structures, and cytoskeletal elements. Among them, the endoplasmic reticulum, Golgi apparatus, mitochondria, and nucleus can be meticulously examined to recognize alterations indicative of cellular responses to various stimuli. Importantly, Weibel-Palade bodies are characteristic secretory organelles found in HUVECs, which can be easily distinguished in the TEM. These distinctive structures also dynamically react to different factors through regulated exocytosis, resulting in complete or selective release of their contents. This detailed review summarizes the ultrastructural features of HUVECs and highlights the utility of TEM as a pivotal tool for analyzing HUVECs in diverse research frameworks, contributing valuable insights into the comprehension of HUVEC behavior and enriching our knowledge into the complexity of vascular biology.

Research progress on the role of reactive oxygen species in the initiation, development and treatment of breast cancer

According to international cancer data, breast cancer (BC) is the leading type of cancer in women. Although significant progress has been made in treating BC, metastasis and drug resistance continue to be the primary causes of mortality for many patients. Reactive oxygen species (ROS) play a dual role in vivo: normal levels can maintain the body's normal physiological function; however, high levels of ROS below the toxicity threshold can lead to mtDNA damage, activation of proto-oncogenes, and inhibition of tumor suppressor genes, which are important causes of BC. Differences in the production and regulation of ROS in different BC subtypes have important implications for the development and treatment of BC. ROS can also serve as an important intracellular signal transduction factor by affecting the antioxidant system, activating MAPK and PI3K/AKT, and other signal pathways to regulate cell cycle and change the relationship between cells and the activity of metalloproteinases, which significantly impacts the metastasis of BC. Hypoxia in the BC microenvironment increases ROS production levels, thereby inducing the expression of hypoxia inducible factor-1α (HIF-1α) and forming "ROS- HIF-1α-ROS" cycle that exacerbates BC development. Many anti-BC therapies generate sufficient toxic ROS to promote cancer cell apoptosis, but because the basal level of ROS in BC cells exceeds that of normal cells, this leads to up-regulation of the antioxidant system, drug efflux, and apoptosis inhibition, rendering BC cells resistant to the drug. ROS crosstalks with tumor vessels and stromal cells in the microenvironment, increasing invasiveness and drug resistance in BC.

Chinese Herbal Compound Xiaoliu Pingyi Recipe Inhibits the Growth of Lung Adenocarcinoma by Regulating the Tumor Vascular Microenvironment

BACKGROUND

The traditional Chinese medicine (TCM) Xiaoliu Pingyi recipe (XLPYR) has been clinically used for several decades, demonstrating favorable therapeutic effects. However, the underlying regulatory mechanisms remain unclear. The aim of this study was to explore the anti-tumor effects of XLPYR and its regulatory role in the vascular microenvironment through in vivo and in vitro experiment.

MATERIALS AND METHODS

In the in vivo study, a C57BL/6J mouse model of lung adenocarcinoma (LUAD) allografts was established, and various interventions were administered for 14 days (Model group: administered normal saline via oral gavage; Pemetrexed (PEM) group: intraperitoneally injected with a solution of pemetrexed, once every 3d; XLPYR group: administered XLPYR via oral gavage; Combination (COMBI) group: received XLPYR via oral gavage simultaneously with intraperitoneal injection of pemetrexed solution). Tumor volume and weight were then compared among the groups. The impact of XLPYR on the tumor vascular microenvironment was assessed using immunohistochemistry staining. In the in vitro study, XLPYR-containing serum was prepared by oral administration to SD rats. The CCK-8 assay evaluated the effect of the serum on the proliferation of normal lung epithelial BEAS-2B cells and LUAD A549 cells, determining the optimal intervention concentrations. The cell migration and invasion abilities were evaluated using the wound-healing assay and Transwell assay, respectively. Finally, ELISA assay measured VEGF secretion levels in the LUAD cell supernatant, and RT-qPCR and Western Blot were employed to detect differences in HIF-1α, VEGFA, Ang-2, and PI3K/Akt mRNA and protein expression levels in both in vivo and in vitro experiments.

RESULTS

In the in vivo study, XLPYR significantly inhibited the growth of mice LUAD allografts, with enhanced anti-tumor effects observed with prolonged drug intervention. Immunohistochemistry staining revealed reduced MVD and increased pericyte coverage in all intervention groups. Regarding vascular function, FITC-Dextran extravasation in the tumor tissues of the Model group was significantly higher than in the intervention groups, particularly with lower extravasation in the COMBI group compared to the PEM group. In the in vitro study, XLPYR demonstrated a time- and concentration-dependent inhibitory effect on LUAD cells, and with greater sensitivity in inhibiting LUAD cells compared to BEAS-2B cells. The wound-healing assay and Transwell assay confirmed that XLPYR significantly suppressed the migration and invasion abilities of LUAD cells. ELISA experiments further revealed a significant decrease in VEGF expression in the supernatant of each intervention group. RT-qPCR and Western Blot results showed consistent findings between the in vivo and in vitro experiments. HIF-1α, VEGFA, and Ang-2 mRNA and protein expression levels were significantly downregulated in the PEM group, XLPYR group, and COMBI group. There were no significant differences in the expression of PI3K and Akt mRNA and total protein, but the expression levels of phosphorylated p-PI3K and p-Akt were notably downregulated.

CONCLUSION

XLPYR significantly inhibited C57BL/6J mouse LUAD allograft growth and improved the vascular microenvironment, thereby intervening in tumor angiogenesis and inducing vascular normalization. It suppressed LUAD cell proliferation, migration, and invasion, while reducing VEGF concentration in the cell supernatant. The regulatory mechanism may involve inhibiting PI3K/Akt protein phosphorylation and downregulating angiogenesis-related factors, such as HIF-1α, VEGF, and Ang-2.