PlGF knockdown attenuates hypoxia-induced stimulation of cell proliferation and glycolysis of lung adenocarcinoma through inhibiting Wnt/β-catenin pathway

Hypoxia-induced ROS aggravate tumor progression through HIF-1α-SERPINE1 signaling in glioblastoma

Hypoxia, as an important hallmark of the tumor microenvironment, is a major cause of oxidative stress and plays a central role in various malignant tumors, including glioblastoma. Elevated reactive oxygen species (ROS) in a hypoxic microenvironment promote glioblastoma progression; however, the underlying mechanism has not been clarified. Herein, we found that hypoxia promoted ROS production, and the proliferation, migration, and invasion of glioblastoma cells, while this promotion was restrained by ROS scavengers N-acetyl-L-cysteine (NAC) and diphenyleneiodonium chloride (DPI). Hypoxia-induced ROS activated hypoxia-inducible factor-1α (HIF-1α) signaling, which enhanced cell migration and invasion by epithelial-mesenchymal transition (EMT). Furthermore, the induction of serine protease inhibitor family E member 1 (SERPINE1) was ROS-dependent under hypoxia, and HIF-1α mediated SERPINE1 increase induced by ROS via binding to the SERPINE1 promoter region, thereby facilitating glioblastoma migration and invasion. Taken together, our data revealed that hypoxia-induced ROS reinforce the hypoxic adaptation of glioblastoma by driving the HIF-1α-SERPINE1 signaling pathway, and that targeting ROS may be a promising therapeutic strategy for glioblastoma.

Hypoxia is fine-tuned by Hif-1α and regulates mesendoderm differentiation through the Wnt/β-Catenin pathway

Background

Hypoxia naturally happens in embryogenesis and thus serves as an important environmental factor affecting embryo development. Hif-1α, an essential hypoxia response factor, was mostly considered to mediate or synergistically regulate the effect of hypoxia on stem cells. However, the function and relationship of hypoxia and Hif-1α in regulating mesendoderm differentiation remains controversial.

Results

We here discovered that hypoxia dramatically suppressed the mesendoderm differentiation and promoted the ectoderm differentiation of mouse embryonic stem cells (mESCs). However, hypoxia treatment after mesendoderm was established promoted the downstream differentiation of mesendoderm-derived lineages. These effects of hypoxia were mediated by the repression of the Wnt/β-Catenin pathway and the Wnt/β-Catenin pathway was at least partially regulated by the Akt/Gsk3β axis. Blocking the Wnt/β-Catenin pathway under normoxia using IWP2 mimicked the effects of hypoxia while activating the Wnt/β-Catenin pathway with CHIR99021 fully rescued the mesendoderm differentiation suppression caused by hypoxia. Unexpectedly, Hif-1α overexpression, in contrast to hypoxia, promoted mesendoderm differentiation and suppressed ectoderm differentiation. Knockdown of Hif-1α under normoxia and hypoxia both inhibited the mesendoderm differentiation. Moreover, hypoxia even suppressed the mesendoderm differentiation of Hif-1α knockdown mESCs, further implying that the effects of hypoxia on the mesendoderm differentiation were Hif-1α independent. Consistently, the Wnt/β-Catenin pathway was enhanced by Hif-1α overexpression and inhibited by Hif-1α knockdown. As shown by RNA-seq, unlike hypoxia, the effect of Hif-1α was relatively mild and selectively regulated part of hypoxia response genes, which fine-tuned the effect of hypoxia on mESC differentiation.

Conclusions

This study revealed that hypoxia is fine-tuned by Hif-1α and regulates the mesendoderm and ectoderm differentiation by manipulating the Wnt/β-Catenin pathway, which contributed to the understanding of hypoxia-mediated regulation of development.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12915-022-01423-y.

Syringin exerts anti-breast cancer effects through PI3K-AKT and EGFR-RAS-RAF pathways

Background

Breast cancer (BC) is one of the most common malignant tumors with the highest mortality in the world. Modern pharmacological studies have shown that Syringin has an inhibitory effect on many tumors, but its anti-BC efficacy and mechanism are still unclear.

Methods

First, Syringin was isolated from Acanthopanax senticosus (Rupr. & Maxim.) Harms (ASH) by systematic solvent extraction and silica gel chromatography column. The plant name is composed of genus epithet, species additive words and the persons’ name who give its name. Then, the hub targets of Syringin against BC were revealed by bioinformatics. To provide a more experimental basis for later research, the hub genes which could be candidate biomarkers of BC and a ceRNA network related to them were obtained. And the potential mechanism of Syringin against BC was proved in vitro experiments.

Results

Syringin was obtained by liquid chromatography-mass spectrometry (LC–MS), nuclear magnetic resonance (NMR), and high-performance liquid chromatography (HPLC). Bioinformatics results showed that MAP2K1, PIK3CA, HRAS, EGFR, Caspase3, and PTGS2 were the hub targets of Syringin against BC. And PIK3CA and HRAS were related to the survival and prognosis of BC patients, the PIK3CA-hsa-mir-139-5p-LINC01278 and PIK3CA-hsa-mir-375 pathways might be closely related to the mechanism of Syringin against BC. In vitro experiments confirmed that Syringin inhibited the proliferation and migration and promoted apoptosis of BC cells through the above hub targets.

Conclusions

Syringin against BC via PI3K-AKT-PTGS2 and EGFR-RAS-RAF-MEK-ERK pathways, and PIK3CA and HRAS are hub genes for adjuvant treatment of BC.

Graphical Abstract