Pictilisib

Fluoxetine is a safe antidepressant with remarkable anti‐inflammatory actions; therefore, we aimed to investigate its effects on immortalized (HaCaT) as well as primary human epidermal keratinocytes in a polyinosinic‐polycytidylic acid (p(I:C))‐induced inflammatory model. We found that a non‐cytotoxic concentration (MTT‐assay, CyQUANT‐assay) of fluoxetine significantly suppressed p(I:C)‐induced expression and release of several pro‐inflammatory cytokines (Q‐PCR, cytokine array, ELISA), and it decreased the release of the itch mediator endothelins (ELISA). These effects were not mediated by the inhibition of the NF‐κB or p38 MAPK pathways (western blot), or by the suppression of the p(I:C)‐induced elevation of mitochondrial ROS production (MitoSOX Red labeling). Instead, unbiased activity profiling revealed that they were most likely mediated via the inhibition of the phosphoinositide 3‐kinase (PI3K) pathway. Importantly, the PI3K‐inhibitor GDC0941 fully mimicked the effects of fluoxetine (Q‐PCR, ELISA). Although fluoxetine was able to occupy the binding site of GDC0941 (in silico molecular docking), and exerted direct inhibitory effect on PI3K (cell‐free PI3K activity assay), it exhibited much lower potency and efficacy as compared to GDC0941. Finally, RNA‐Seq analysis revealed that fluoxetine deeply influenced the transcriptional alterations induced by p(I:C)‐treatment, and exerted an overall anti‐inflammatory activity. Collectively, our findings demonstrate that fluoxetine exerts potent anti‐inflammatory effects, and suppresses the release of the endogenous itch mediator endothelins in human keratinocytes, most likely via interfering with the PI3K pathway. Thus, clinical studies are encouraged to explore whether the currently reported beneficial effects translate in vivo following its topical administration in inflammatory and pruritic dermatoses.

Poorly differentiated esophageal adenocarcinoma (PDEAC) has a dismal prognosis. Glypican-1(GPC-1) is known to be upregulated in several cancer types in contrast to healthy tissues, rendering it as a biomarker. Nevertheless, the potential therapeutic targeting of GPC-1 has not been explored in PDEAC. There is accumulating evidence that GPC-1, via upregulation of PI3K/Akt/ERK signaling, plays a crucial role in the progression and chemoresistance in cancer. Pictilisib, a class I pan PI3K inhibitor, has shown promising antitumor results in clinical trials, however, has not gained widespread success due to acquired drug resistance. This study investigated the role of GPC-1 in chemo-resistant PDEAC and appraises the impact of targeted silencing of GPC-1 on the antitumor effects of Pictilisib in PDEAC cell lines. Immunohistochemistry assays in PDEAC tissue specimens demonstrated a pronounced intensity of staining with GPC-1. Upregulation of GPC-1 was found to be correlated with advanced stage and poor prognosis. In-vitro studies examined the influence of GPC-1 knockdown and Pictilisib, both as individual agents and in combination, on cytotoxicity, cell cycle distribution, apoptosis, and gene expression profiles. Silencing GPC-1 alone showed significantly reduced cell viability, migration, colony formation, epithelial-mesenchymal transition, and stemness in PDEAC cells. Significantly, knockdown of GPC-1 combined with low-dose Pictilisib led to enhancement of cytotoxicity, cell cycle arrest, and apoptosis in ESO-26 and OE-33 cells. In the xenograft mouse model, the combination of Pictilisib and GPC-1 knockdown exhibited synergy. These findings suggest that GPC-1 represents a promising target to augment chemosensitivity in esophageal adenocarcinoma.