Discovery of Novel Imidazo[1,2-a]pyridine-Based HDAC6 Inhibitors as an Anticarcinogen with a Cardioprotective Effect.

Cardiotoxicity associated with chemotherapy has gradually become the major cause of death in cancer patients. The development of bifunctional drugs with both cardioprotective and antitumor effects has become the future direction. HDAC6 plays important roles in the progression, treatment, and prognosis of cancer and cardiovascular diseases, but bifunctional inhibitors have not been reported. Herein, structure-activity relationship studies driven by pharmacophore-based remodification and fragment-based design were performed to yield highly potent HDAC6 inhibitor I-c4 containing imidazo[1,2-a]pyridine. Importantly, I-c4 effectively suppressed the growth of MGC-803 xenografts in vitro and in vivo by inhibiting the deacetylation pathway without causing myocardial damage after long-term administration. Meanwhile, I-c4 could mitigate severe myocardial damage against H2O2 or myocardial ischemia/reperfusion in vitro and in vivo. Further studies revealed that the cardioprotective effect of I-c4 was associated with reduction of inflammatory cytokines. Taken together, I-c4 may represent a novel lead compound for further development of an anticarcinogen with a cardioprotective effect.

Lysine-Specific Demethylase 1 Promises to Be a Novel Target in Cancer Drug Resistance: Therapeutic Implications.

Chemotherapy, targeted therapy, and immunotherapy are effective against most tumors, but drug resistance remains a barrier to successful treatment. Lysine-specific demethylase 1 (LSD1), a member of histone demethylation modifications, can regulate invasion, metastasis, apoptosis, and immune escape of tumor cells, which are associated with tumorigenesis and tumor progression. Recent studies suggest that LSD1 ablation regulates resensitivity of tumor cells to anticarcinogens containing immune checkpoint inhibitors (ICIs) via multiple upstream and downstream pathways. In this review, we describe the recent findings about LSD1 biology and its role in the development and progression of cancer drug resistance. Further, we summarize LSD1 inhibitors that have a reversal or resensitive effect on drug resistance and discuss the possibility of targeting LSD1 in combination with other agents to surmount resistance.

Discovery of 1,3,4-oxadiazole derivatives containing a bisamide moiety as a novel class of potential cardioprotective agents.

Myocardial injury is a nonnegligible problem in cardiovascular diseases and cancer therapy. The functional feature of N-containing heterocycles in the cardiovascular field has attracted much attention in recent years. Herein, we discovered a lead compound 12a containing 1,3,4-oxadiazole by extensive screening of anticancer derivatives containing nitrogen-heterocycle, which exhibited potential protective activity against oxidative stress in cardiomyocytes. Follow-up structure-activity relationship (SAR) studies also highlighted the role of substitution sites and bisamide moiety in enhancing the protective activity against oxidative stress. Specifically, compound 12d exhibited low cytotoxicity under high concentration and potent myocardial protection against oxidative stress in H9c2 cells. Preliminary mechanistic studies showed compound 12d could decrease the expression of cardiac hypertrophy and oxidative stress-related proteins/genes and reduce mitochondria-mediated cell apoptosis, thereby enhancing the cell vitality of injured cardiomyocytes. In this study, 1,3,4-oxadiazole may represent a novel pharmacophore that possesses potential myocardial protection and provides more choices for future optimization of cardiovascular drugs, especially for the treatment of onco-cardiology.

Discovery of cinnamamide-barbiturate hybrids as a novel class of Nrf2 activator against myocardial ischemia/reperfusion injury.

Myocardial ischemia/reperfusion (MI/R) has been a challenge for global public health. Activation of nuclear factor erythroid-2-related factor 2 (Nrf2) signaling could attenuate MI/R injury by maintaining cell redox balance and reducing oxidative damage. Cinnamamide derivatives have been proven to be a class of potential Nrf2 activators and cardioprotective agents. The development of novel cinnamamide derivatives to combat oxidative stress in cardiomyocytes is highly desirable. In this study, twenty-three cinnamamide-barbiturate hybrids were studied. Cell-based assays showed that most of the compounds exhibited excellent protective activity against H2O2-induced oxidative injury in H9c2 cells. Notably, compound 7w, which had the highest activity and low cytotoxicity, was demonstrated to remarkably reduce intracellular ROS accumulation by activating the mRNA expression of Nrf2 and its downstream antioxidant gene HO-1, indicating a novel promising antioxidant and Nrf2 activator. The probable binding mode between protein Keap1 and compound 7w was also studied via molecule docking. Furthermore, we found that the administration of compound 7w could significantly reduce the cardiac infarct size and improve the cardiac function against MI/R injury in rats, as well as decrease cardiac oxidative stress. Taken together, we report, for the first time, that cinnamamide-barbiturate hybrids are a novel class of potential cardioprotective agents. The excellent cardioprotective action of such compounds rely on enhancing the endogenous antioxidative system by upregulating the Nrf2 signaling pathway in vitro and in vivo against MI/R damage. These findings provide a new perspective for designing cinnamamide-barbiturate hybrids as a novel class of Nrf2 activator against cardiovascular diseases.

[High maintenance dose of clopidogrel improves long-term clinical outcomes in patients with elective percutaneous coronary intervention].

OBJECTIVE: To evaluate the efficacy of a 300 mg loading dose of clopidogrel followed by 150 mg as maintenance dose in patients with percutaneous coronary intervention (PCI). METHODS: A total of 108 consecutive patients undergoing elective PCI were recruited from our hospital from July 2007 to July 2008. A 300 mg loading dose was administered prior to PCI. Then they were randomized to receive clopidogrel 75 mg (n = 55) or 150 mg (n = 46) daily for 30 days. From Day 30 to Month 6 post-operation, all of them received 75 mg/d clopidogrel and were followed up for a mean period of 6 months. RESULTS: Thirty days after PCI, the platelet inhibition of the 150 mg group was significantly higher than the 75 mg group (64.2% ± 13.3% vs 52.6% ± 14.3%, P = 0.00). The ratios of fatal or non-fatal myocardial infarction (MI) (1(1.8%) vs 3 (6.5%), P = 0.405) and target vessel revascularization (TVR) (4(7.2%) vs 6 (13.0%), P = 0.714) were significantly lower in the 150 mg group than those in the 75 mg group. So the overall incidence of MACE including death, MI and TVR was obviously lower in the 150 mg group than that in the 75 mg group (13.0% vs 20.2%, absolute risk reduction 7.3%). CONCLUSION: A high clopidogrel maintenance dose of 150 mg daily for the first month after PCI reduces the risk of long-term adverse events in patients with elective percutaneous coronary intervention.