Elevated glucose levels at the fetal–maternal interface are associated with placental trophoblast dysfunction and increased incidence of pregnancy complications. Trophoblast cells predominantly utilize glucose as an energy source, metabolizing it through glycolysis in the cytoplasm and oxidative respiration in the mitochondria to produce ATP. The TGFβ1/SMAD2 signaling pathway and the transcription factors PPARγ, HIF1α, and AMPK are key regulators of cell metabolism and are known to play critical roles in extravillous trophoblast cell differentiation and function. While HIF1α promotes glycolysis over mitochondrial respiration, PPARγ and AMPK encourage the opposite. However, the interplay between TGFβ1 and these energy-sensing regulators in trophoblast cell glucose metabolism remains unclear. This study aimed to investigate whether and how TGFβ1 regulates energy metabolism in trophoblast cells exposed to normal and high glucose conditions. The trophoblast JEG-3 cells were incubated in normal (5 mM) and high (25 mM) glucose conditions for 24 h in the absence and the presence of TGFβ1. The protein expression levels of phosphor (p)-SMAD2, GLUT1/3, HIF1α, PPARγ, p-AMPK, and specific OXPHOS protein subunits were determined by western blotting, and ATP and lactate production by bioluminescent assay kits. JEG-3 cells exposed to 25 mM glucose decreased ATP production but did not affect lactate production. These changes led to a reduction in the expression levels of GLUT1/3, mitochondrial respiratory chain proteins, and PPARγ, coinciding with an increase in HIF1α expression. Conversely, TGFβ1 treatment at 25 mM glucose reduced HIF1α expression while enhancing the expression levels of GLUT1/3, PPARγ, p-AMPK, and mitochondrial respiratory chain proteins, thereby rejuvenating ATP production. Our findings reveal that high glucose conditions disrupt cellular glucose metabolism in trophoblast cells by perturbing mitochondrial oxidative respiration and decreasing ATP production. Treatment with TGFβ1 appears to counteract this trend, probably by enhancing both glycolytic and mitochondrial metabolism, suggesting a potential regulatory role of TGFβ1 in placental trophoblast cell glucose metabolism.

Interleukin-6 (IL-6) superfamily cytokines play critical roles during human pregnancy by promoting trophoblast differentiation, invasion, and endocrine function, and maintaining embryo immunotolerance and protection. In contrast, the unbalanced activity of pro-inflammatory factors such as interferon gamma (IFNγ) and granulocyte–macrophage colony-stimulating factor (GM-CSF) at the maternal–fetal interface have detrimental effects on trophoblast function and differentiation. This study demonstrates how the IL-6 cytokine family member oncostatin M (OSM) and STAT3 activation regulate trophoblast fusion and endocrine function in response to pro-inflammatory stress induced by IFNγ and GM-CSF. Using human cytotrophoblast-like BeWo (CT/BW) cells, differentiated in villous syncytiotrophoblast (VST/BW) cells, we show that beta-human chorionic gonadotrophin (βhCG) production and cell fusion process are affected in response to IFNγ or GM-CSF. However, those effects are abrogated with OSM by modulating the activation of IFNγ-STAT1 and GM-CSF-STAT5 signaling pathways. OSM stimulation enhances the expression of STAT3, the phosphorylation of STAT3 and SMAD2, and the induction of negative regulators of inflammation (e.g., IL-10 and TGFβ1) and cytokine signaling (e.g., SOCS1 and SOCS3). Using STAT3-deficient VST/BW cells, we show that STAT3 expression is required for OSM to regulate the effects of IFNγ in βhCG and E-cadherin expression. In contrast, OSM retains its modulatory effect on GM-CSF-STAT5 pathway activation even in STAT3-deficient VST/BW cells, suggesting that OSM uses STAT3-dependent and -independent mechanisms to modulate the activation of pro-inflammatory pathways IFNγ-STAT1 and GM-CSF-STAT5. Moreover, STAT3 deficiency in VST/BW cells leads to the production of both a large amount of βhCG and an enhanced expression of activated STAT5 induced by GM-CSF, independently of OSM, suggesting a key role for STAT3 in βhCG production and trophoblast differentiation through STAT5 modulation. In conclusion, our study describes for the first time the critical role played by OSM and STAT3 signaling pathways to preserve and regulate trophoblast biological functions during inflammatory stress.

Macrophage-mediated inflammation is known to be involved in the epithelial–mesenchymal transition (EMT) of various types of cancer. This makes macrophage-derived inflammatory factors prime targets for the development of new treatments. This study uncovers the therapeutic potential and action mechanism of DAB-2-28, a small-molecule derived from para-aminobenzoic acid, in the treatment of breast cancer. The luminal MCF-7 and the triple-negative MDA-MB-231 cancer cell lines used in this study represent, respectively, breast cancers in which the differentiation states are related to the epithelial phenotype of the mammary gland and breast cancers expressing a highly aggressive mesenchymal phenotype. In MCF-7 cells, soluble factors from macrophage-conditioned media (CM-MØ) induce a characteristic morphology of mesenchymal cells with an upregulated expression of Snail1, a mesenchymal marker, as opposed to a decrease in the expression of E-cadherin, an epithelial marker. DAB-2-28 does not affect the differential expression of Snail1 and E-cadherin in response to CM-MØ, but negatively impacts other hallmarks of EMT by decreasing invasion and migration capacities, in addition to MMP9 expression and gelatinase activity, in both MCF-7 and MDA-MB-231 cells. Moreover, DAB-2-28 inhibits the phosphorylation of key pro-EMT transcriptional factors, such as NFκB, STAT3, SMAD2, CREB, and/or AKT proteins, in breast cancer cells exposed to different EMT inducers. Overall, our study provides evidence suggesting that inhibition of EMT initiation or maintenance is a key mechanism by which DAB-2-28 can exert anti-tumoral effects in breast cancer cells.

Macrophage-mediated inflammation is proposed to be involved in the epithelial-mesenchymal transition (EMT) of different types of cancers. This makes macrophage-derived inflammatory factors a prime target for developing new treatments. This study aims to demonstrate the therapeutic potential and mechanism of action of DAB-2-28, a novel small molecule derived from aminobenzoic acid, in the treatment of breast cancer. The luminal MCF-7 and the triple-negative MDA-MB-231 cancer cell lines used in this study represent, respectively, a breast cancer whose differentiation state is related to the epithelial phenotype of the mammary gland, and a breast cancer expressing a highly aggressive mesenchymal phenotype. In MCF-7 cells, soluble factors from macrophage-conditioned media (MØ-CM) induce a characteristic morphology of mesenchymal cells with an increase in the expression of Snail1, a mesenchymal marker, opposed to a decrease in the expression of E-cadherin, an epithelial marker. Although our studies demonstrated that DAB-2-28 does not affect the differential expression of Snail1 and E-cadherin, DAB-2-28 negatively regulates the different responses of MCF-7 cells to MØ-CM by decreasing a) clonogenic growth; b) invasion and migration capacities; c) MMP9 expression and gelatinase activity; and d) NFkB, STAT3, AKT, and SMAD2 protein phosphorylation. Moreover, differential expression of Snail1 and E-cadherin in MCF-7 cells was also induced by the cytokines TNFa and TGFb1, alone or in combination, and the StemXvivo® EMT Inducing Media reagent. DAB-2-28 affects the response of MCF-7 cells to these various EMT inducers by inhibiting the phosphorylation of NFkB, SMAD2 and/or CREB proteins. Finally, DAB-2-28 also decreases the macrophage- and cytokine-induced invasion and migration capacities of MDA-MB-231 cells, probably via an inhibition of MMP9 activity and the phosphorylation of NFkB, STAT3, AKT, SMAD2, and CREB proteins. We propose that the ability of DAB-2-28 to prevent cancer cells from acquiring EMT-related protumor properties could be exploited in a clinical setting to block disease progression to a metastatic form and thus improve the survival rate of breast cancer patients.

The design of innovative compounds displaying anti-inflammatory activity in oncological context is a subject of great interest in drug development. It has been proved that a pro-inflammatory microenvironment which accelerates cancer growth and cellular differentiation is often present in malignant bladder tumor. In earlier work, we reported the synthesis of p-aminobenzoic acid derivatives that act as anti-inflammatory compounds able to inhibit the pro-inflammatory markers present in bladder cancer microenvironment. DAB-1 rapidly emerged as an effective lead candidate in this investigation, with its ability to shrink by 90% in 25 days the size of human bladder cancer tumors in an ectopic mouse model. This manuscript discloses the synthesis of 23 new hydrazide derivatives of DAB-1 and reports their in vitro and in vivo biological evaluation. It was discovered that most of the new compounds are essentially nontoxic against RAW 264.7 cells, as evaluated by an MTT assay. Anti-inflammatory activity of the new derivatives was investigated by evaluation of their impact on cellular nitric oxide production, measured by a Griess assay. Some compounds did significatively inhibit nitric oxide production much more effectively than the original DAB-1. Striking activity of 14, which is around four times more potent than DAB-1, promotes this derivative as new lead compound in this study. The study of these analogs reveals that a phenolic/anisole core is a key component to achieve high biological activity. Furthermore, mice models of acute inflammation and invasive BCa tumors were used to assess the in vivo impact of derivative 14, and it was found that this compound does reduce inflammation in these mice, possess similar anti-inflammatory activity but higher anti-tumoral activity compared to DAB-1 with no apparent signs of toxicity.