Innovative challenge for the inhibition of hepatocellular carcinoma progression by combined targeting of HSP90 and STAT3/HIF-1α signaling.

Hepatocellular carcinoma (HCC) is the third foremost cause of cancer-related deaths. HCC has a very bad prognosis because it is asymptomatic in the early stages, resulting in a late diagnosis, and it is highly resistant to conventional chemotherapy. Such chemotherapies have been proven disappointing because they provide extremely low survival benefits. This study discloses that the STAT3/HIF-1α is an auspicious therapeutic attack site for conceivable repression of HCC development. A site that can be targeted by simultaneous administration of a STAT3 inhibitor in the context of HSP90 inhibition. 17-DMAG binds to HSP90 and constrains its function, resulting in the degradation of HSP90 client proteins HIF-1α and STAT3. Hypoxia recruits STAT3/HIF-1α complex within the VEGF promoter. Additionally, it was acknowledged that STAT3 is an essential mediator of VEGF transcription by direct binding to its promoter. Furthermore, it induces HIF-1α stability and enhances its transcriptional activity. Herein, we revealed that the combination therapy using 17-DMAG and nifuroxazide, a STAT3 inhibitor, repressed the diethylnitrosamine-induced alterations in the structure of the liver. This effect was mediated via decreasing the levels of the HSP90 client proteins HIF-1α and pSTAT3 resulting in the suppression of the STAT3/HIF-1α complex transcriptional activity. To conclude, 17-DMAG/NFXZD combination therapy-induced disruption in the STAT3/HIF-1α loop led to a potential antiangiogenic activity and showed apoptotic potential by inhibiting autophagy and inducing ROS/apoptosis signaling. Additionally, this combination therapy exhibited promising survival prolongation in mice with HCC. Consequently, the use of 17-DMAG/NFXZD renders an inspirational perspective in managing HCC. However, further investigations are compulsory.

Diacetylrhein, an anthraquinone antiarthritic agent, suppresses dextran sodium sulfate-induced inflammation in rats: A possible mechanism for a protective effect against ulcerative colitis.

Ulcerative colitis (UC) is a chronic inflammatory life-threatening and premalignant disorder with no cure that even might end up with surgical removal of a large section or even all of the colon. It is characterized by relapsing-remitting courses of intestinal inflammation and mucosal damage in which oxidative stress and exaggerated inflammatory response play a significant role. Most of the current medications to maintain remission are symptomatic and have many adverse reactions. Therefore, the potential for improved management of patients with UC continues to increase. Yet, the benefits of using the antiarthritic agent diacetylrhein to counteract inflammation in UC are still obscure. Hence, our study was designed to explore its potential role in UC using a model of dextran sodium sulfate-induced acute colitis in rats. Our results revealed that diacetylrhein targeted the NLRP3 and inhibited the inflammasome assembly. Consequently, caspase-1 activity and the inflammatory cytokines IL-1ß and IL-18 were inhibited leading to a curbed pyroptosis process. Additionally, diacetylrhein revealed a significant antiapoptotic potential as revealed by the levels of pro-apoptotic and anti-apoptotic proteins. Concomitant to these effects, diacetylrhein also interrupted NFκB signals leading to improved microscopic features of inflamed colon and decreased colon weight to length ratio, indices of disease activity, and macroscopic damage. Additionally, a reduction in the myeloperoxidase activity, IL-6, and TGF-ß alongside an increase in the gene expression of Ocln and ZO-1 were detected. To conclude diacetylrhein showed a significant antioxidant and anti-inflammatory potential and therefore might represent a promising agent in the management of acute UC.