Apoptosis In Types Research Articles

Gymnemic acid protects murine pancreatic β-cells by moderating hyperglycemic stress-induced inflammation and apoptosis in type 1 diabetic rats.

Type 1 diabetes is a chronic immune-mediated disease caused by pancreatic β-cell dysfunction with consequent severe insulin deficiency. Exacerbated blood glucose levels can cause oxidative stress in the pancreatic β-cells, which leads to inflammation, and apoptosis resulting in islet dysfunction. Although massive studies have been carried out to elucidate the causative factors for β-cell damage in diabetes, the therapeutic approach to pancreatic β-cell damage has not been extensively studied. Hence, the present study has been designed to delineate the role of gymnemic acid (GA) in protecting pancreatic β-cells in diabetic animals, with special reference to inflammation and apoptosis. Our data revealed that the treatment with GA significantly reverted the alteration in both biochemical and histochemical observations in young diabetic rats. Moreover, treatment with the GA downregulates the expression of proinflammatory markers (nuclear factor-κB, tumor necrosis factor-α, interleukin-[IL]-6, and IL-1β), proapoptotic proteins (Bax, cytochrome c, and cleaved caspase-3), as well as upregulates the expression of antiapoptotic protein Bcl-2 in diabetic rats. These findings suggest that the anti-inflammatory and antiapoptotic nature of GA mitigates β-cell damage in hyperglycemic rats.

Ferroptosis, as the most enriched programmed cell death process in glioma, induces immunosuppression and immunotherapy resistance.

Immunosuppressive microenvironment is a major cause of immunotherapeutic resistance in glioma. In addition to secreting compounds, tumor cells under programmed cell death (PCD) processes release abundant mediators to modify the neighboring microenvironment. However, the complex relationship among PCD status, immunosuppressive microenvironment, and immunotherapy is still poorly understood. Four independent glioma cohorts comprising 1,750 patients were enrolled for analysis. The relationships among PCD status, microenvironment cellular components, and biological phenotypes were fully explored. Tissues from our hospital and experiments in vitro and in vivo were used to confirm the role of ferroptosis in glioma. Analyses to determine enriched PCD processes showed that ferroptosis was the main type of PCD in glioma. Enriched ferroptosis correlated with progressive malignancy, poor outcomes, and aggravated immunosuppression in glioblastoma (GBM) patients. Enhanced ferroptosis was shown to induce activation and infiltration of immune cells but attenuated antitumor cytotoxic killing. Tumor-associated macrophages (TAMs) were found to participate in ferroptosis-mediated immunosuppression. Preclinically, ferroptosis inhibition combined with Programmed Cell Death 1 (PD-1) and Programmed Cell Death Ligand-1 (PD-L1) blockade generated a synergistic therapeutic outcome in GBM murine models. This work provides a molecular, clinical, and biological landscape of ferroptosis, suggesting a role of ferroptosis in glioma malignancy and a novel synergic immunotherapeutic strategy that combines immune checkpoint blockade treatment with ferroptosis inhibition.

Programmed cell death and liver diseases

Cell death represents the most critical pathologic entity in liver disease, which dictates pathologic consequences such as inflammation, fibrosis, and cell transformation. We analyzed the conclusions of studies on the involvement of different types of programmed cell death (PCD) in the pathogenesis of liver diseases. Three main forms of PCD (autophagy, apoptosis, necrosis) and five additional, still insufficiently studied PCD – necroptosis, ferroptosis, pyroptosis, partanatosis and entosis – observed in the liver in various acute and chronic diseases are considered. The involvement of several PCD at once in the development of any one pathology and one type of PCD in different pathologies was established. This indicates the existence of cross-regulation of metabolism in the liver cells with different levels of damage in the formation of the main dominant type of PCD. Available results indicate the possibility of attenuation (correction) of functional and morphological manifestations of PCD in the organ by controlled blocking of effector-mediated PCD pathways, as well as targeted induction of autophagy, anti-apoptotic and anti-necrotic mechanisms in liver cells.

Apoptosis in Type 2 Diabetes: Can It Be Prevented? Hippo Pathway Prospects.

Diabetes mellitus is a heterogeneous disease of complex etiology and pathogenesis. Hyperglycemia leads to many serious complications, but also directly initiates the process of β cell apoptosis. A potential strategy for the preservation of pancreatic β cells in diabetes may be to inhibit the implementation of pro-apoptotic pathways or to enhance the action of pancreatic protective factors. The Hippo signaling pathway is proposed and selected as a target to manipulate the activity of its core proteins in therapy-basic research. MST1 and LATS2, as major upstream signaling kinases of the Hippo pathway, are considered as target candidates for pharmacologically induced tissue regeneration and inhibition of apoptosis. Manipulating the activity of components of the Hippo pathway offers a wide range of possibilities, and thus is a potential tool in the treatment of diabetes and the regeneration of β cells. Therefore, it is important to fully understand the processes involved in apoptosis in diabetic states and completely characterize the role of this pathway in diabetes. Therapy consisting of slowing down or stopping the mechanisms of apoptosis may be an important direction of diabetes treatment in the future.

TMT induces apoptosis and necroptosis in mouse kidneys through oxidative stress-induced activation of the NLRP3 inflammasome

Trimethyltin chloride (TMT) is an organotin heat stabilizer that is widely used in the production of plastics, and has strong toxicity. Here, the effect of trimethyltin chloride on mouse kidneys and its related mechanism were studied by taking TMT mouse with drinking water as a model. Histological examination and TUNEL results showed that the trimethyltin chloride group had typical apoptosis and necroptosis characteristics. Therefore, the level of oxidative stress was detected,and the expression of related genes was verified by real-time quantitative polymerase chain reaction (qRT-PCR) and Western blot methods. The results showed that oxidative stress was activated (MDA,SOD,CAT,T-AOC), released ROS, activated NF-κB pathway,activated inflammasome (NLRP3,Caspase-1,ASC), and inflammasome-secreted inflammatory factors (IL-1β). The expression of apoptosis (BCL-2, BAX, Caspase-3, Caspase-9) and necroptosis (RIPK1, RIPK33, MLKL, Caspase-8) increased.In addition, HEK293T human embryonic kidney cells were treated with trimethyltin chloride, and the results were similar to the tissue. In conclusion, TMT can induce oxidative stress, activate NF-κB pathway, and induce apoptosis and necroptosis through inflammasomes.

Apoptosis, autophagic cell death, and necroptosis: different types of programmed cell death in bovine corpus luteum regression.

In mammals, the corpus luteum (CL) is a transient organ that secretes progesterone (P4). In the absence of pregnancy, the CL undergoes regression (luteolysis), which is a crucial preparation step for the next estrous cycle. Luteolysis, initiated by uterine prostaglandin F2α (PGF) in cattle, is usually divided into two phases, namely functional luteolysis characterized by a decline in P4 concentration and structural luteolysis characterized by the elimination of luteal tissues from the ovary. Programmed cell death (PCD) of luteal cells, including luteal steroidogenic cells (LSCs) and luteal endothelial cells (LECs), plays a crucial role in structural luteolysis. The main types of PCD are caspase-dependent apoptosis (type 1), autophagic cell death (ACD) via the autophagy-related gene (ATG) family (type 2), and receptor-interacting protein kinase (RIPK)-dependent programmed necrosis (necroptosis, type 3). However, these PCD signaling pathways are not completely independent and interact with each other. Over the past several decades, most studies on luteolysis have focused on apoptosis as the principal mode of bovine luteal cell death. Recently, ATG family members were reported to be expressed in bovine CL, and their levels increased during luteolysis. Furthermore, the expression of RIPKs, which are crucial mediators of necroptosis, is reported to increase in bovine CL during luteolysis and is upregulated by pro-inflammatory cytokines in bovine LSCs and LECs. Therefore, apoptosis, ACD, and necroptosis may contribute to bovine CL regression. In this article, we present the recent findings regarding the mechanisms of the three main types of PCD and the contribution of these mechanisms to luteolysis.

Targeting Ferroptosis as a Novel Approach to Alleviate Aortic Dissection.

A variety of programmed cell death types have been shown to participate in the loss of smooth muscle cells (SMCs) during the development of aortic dissection (AD), but it is still largely unclear whether ferroptosis is involved in the development of AD. In the present study, we found that the expression of key ferroptosis regulatory proteins, solute carrier family 7 member 11 (SLC7A11), ferroptosis suppressor protein 1 (FSP1) and glutathione peroxidase 4 (GPX4) were downregulated in aortas of Stanford type A AD (TAAD) patients, and liproxstatin-1, a specific inhibitor of ferroptosis, obviously abolished the β-aminopropionitrile (BAPN)-induced development and rupture of AD in mice. Furthermore, the expression of methyltransferase-like 3 (METTL3), a major methyltransferase of RNA m6A, was remarkably upregulated in the aortas of TAAD patients, and the protein levels of METTL3 were negatively correlated with SLC7A11 and FSP1 levels in human aortas. Overexpression of METTL3 in human aortic SMCs (HASMCs) inhibited, while METTL3 knockdown promoted SLC7A11 and FSP1 expression. More importantly, overexpression of METTL3 facilitated imidazole ketone erastin- and cystine deprivation-induced ferroptosis, while knockdown of METTL3 repressed ferroptosis of HASMCs. Overexpression of either SLC7A11 or FSP1 largely abrogated the effect of METTL3 on HASMC ferroptosis. Therefore, we have revealed that ferroptosis is a critical cause of AD in both humans and mice and that METTL3 promotes ferroptosis of HASMCs by inhibiting the expression of SLC7A11 and FSP1. Thus, targeting ferroptosis or m6A RNA methylation is a potential novel strategy for the treatment of AD.

Telmisartan attenuates diabetic nephropathy by mitigating oxidative stress and inflammation, and upregulating Nrf2/HO-1 signaling in diabetic rats

Diabetic nephropathy (DN) is a serious complication of diabetes and can lead to renal failure. Telmisartan (TEL) is an approved angiotensin II type 1 receptor blocker for the treatment of hypertension and possesses nephroprotective efficacy. The study investigated the beneficial effect of TEL on renal oxidative stress, inflammatory response, and apoptosis in type 1 diabetic rats, pointing to the possible role of Nrf2/HO-1 signaling. Diabetes was induced by streptozotocin (STZ), and TEL (5 and 10 mg/kg) was supplement for 8 weeks. TEL ameliorated hyperglycemia, prevented body weight loss and kidney hypertrophy, decreased serum creatinine and urea, and prevented histopathological alterations in diabetic rats. Malondialdehyde (MDA), nitric oxide (NO), NF-κB p65 and TNF-α were increased, whereas GSH, SOD and Bcl-2 were decreased in the kidney of diabetic rats. Treatment with TEL ameliorated oxidative stress, suppressed NF-κB p65 and TNF-α, and boosted cellular antioxidant defenses and Bcl-2. TEL upregulated Nrf2 and HO-1 in the kidney of both normal and diabetic rats. In addition, TEL downregulated VEGF and MMP-9 in the kidney of diabetic rats. In silico molecular docking simulations revealed the potent binding affinity of TEL to NF-κB, MMP-9, Keap1 and HO-1. In conclusion, TEL attenuates DN by ameliorating hyperglycemia, oxidative stress, inflammation, apoptosis and angiogenesis and upregulation of Nrf2/HO-1 signaling.

Curcin C inhibit osteosarcoma cell line U2OS proliferation by ROS induced apoptosis, autophagy and cell cycle arrest through activating JNK signal pathway

Osteosarcoma is a kind of primary bone malignant tumors. Its cure rate has been stagnant in the past decade years. Curcin C belongs to type I ribosome inactivating proteins, extracted from the cotyledons of post-germinated Jatropha curcas seeds. It can inhibit the proliferation of several tumor lines including U2OS cells with extraordinary efficiency. The treated U2OS cells were arrested in both S and G2/M phase, showed typical apoptosis morphological characteristic, formed autophagosomes and increase the ratio of LC3II to LC3I. Meanwhile, the level of ROS in the treated cells was found increasing significantly, with the change of mitochondrial membrane potential and decreased antioxidant enzyme activities. The application of ROS scavenger NAC not only significantly inhibited the toxicity of Curcin C but also prevented the happen of apoptosis and autophagy to some extent. These results suggested that Curcin C may function through ROS pathway. In addition, the Curcin C treatment could activate JNK and inhibit ERK signal pathway. Sp600125, an inhibitor of JNK signaling pathway, can prevent subsequent apoptosis and autophagy events, suggesting that JNK pathway was at least one of the pathways of Curcin C action. Moreover, the relevant including antagonistic among autophagy, apoptosis and cell cycle arresting induced by Curcin C also was found. In summary, it can be speculated that Curcin C may induce S, G2/M phase arrest, apoptosis and autophagy of human osteosarcoma U2OS cells through activating JNK signal pathway and blocking ERK signal pathway by promoting ROS accumulation in cell, thus finally reflected in the effect of inhibiting tumor cell proliferation.

Synergism of a novel MCL‑1 downregulator, acriflavine, with navitoclax (ABT‑263) in triple‑negative breast cancer, lung adenocarcinoma and glioblastoma multiforme.

Myeloid cell leukemia sequence 1 (MCL-1), an anti-apoptotic B-cell lymphoma 2 (BCL-2) family molecule frequently amplified in various human cancer cells, is known to be critical for cancer cell survival. MCL-1 has been recognized as a target molecule for cancer treatment. While various agents have emerged as potential MCL-1 blockers, the present study presented acriflavine (ACF) as a novel MCL-1 inhibitor in triple-negative breast cancer (TNBC). Further evaluation of its treatment potential on lung adenocarcinoma and glioblastoma multiforme (GBM) was also investigated. The anticancer effect of ACF on TNBC cells was demonstrated when MDA-MB-231 and HS578T cells were treated with ACF. ACF significantly induced typical intrinsic apoptosis in TNBCs in a dose- and time-dependent manner via MCL-1 downregulation. MCL-1 downregulation by ACF treatment was revealed at each phase of protein expression. Initially, transcriptional regulation via reverse transcription-quantitative PCR was validated. Then, post-translational regulation was explained by utilizing an inhibitor against protein biosynthesis and proteasome. Lastly, immunoprecipitation of ubiquitinated MCL-1 confirmed the post-translational downregulation of MCL-1. In addition, the synergistic treatment efficacy of ACF with the well-known MCL-1 inhibitor ABT-263 against the TNBC cells was explored [combination index (CI)<1]. Conjointly, the anticancer effect of ACF was assessed in GBM (U87, U251 and U343), and lung cancer (A549 and NCI-H69) cell lines as well, using immunoblotting, cytotoxicity assay and FACS. The effect of the combination treatment using ACF and ABT-263 was estimated in GBM (U87, U343 and U251), and non-small cell lung cancer (A549) cells likewise. The present study suggested a novel MCL-1 inhibitory function of ACF and the synergistic antitumor effect with ABT-263.

Programmed Cell Death: Complex Regulatory Networks in Cardiovascular Disease.

Abnormalities in programmed cell death (PCD) signaling cascades can be observed in the development and progression of various cardiovascular diseases, such as apoptosis, necrosis, pyroptosis, ferroptosis, and cell death associated with autophagy. Aberrant activation of PCD pathways is a common feature leading to excessive cardiac remodeling and heart failure, involved in the pathogenesis of various cardiovascular diseases. Conversely, timely activation of PCD remodels cardiac structure and function after injury in a spatially or temporally restricted manner and corrects cardiac development similarly. As many cardiovascular diseases exhibit abnormalities in PCD pathways, drugs that can inhibit or modulate PCD may be critical in future therapeutic strategies. In this review, we briefly describe the process of various types of PCD and their roles in the occurrence and development of cardiovascular diseases. We also discuss the interplay between different cell death signaling cascades and summarize pharmaceutical agents targeting key players in cell death signaling pathways that have progressed to clinical trials. Ultimately a better understanding of PCD involved in cardiovascular diseases may lead to new avenues for therapy.

Immune Modulatory Effect of Outer Membrane Vesicles Derived from Salmonella on Mouse Bone Marrow-Derived Dendritic Cells

To study the effect of outer membrane vesicles (OMVs) derived from Salmonella typhimurium (ST) on the ultrastructural features and immune function of dendritic cells (DC). Mice bone marrow cells were collected aseptically, and myeloid DC were generated by the combined induction and amplification with recombinant mouse granulocyte-macrophage colony-stimulating factor (GM-CSF) and recombinant mouse interleukin-4 (rm IL-4). Cell morphology was observed under inverted phase contrast microscope and the phenotype was identified with flow cytometry. ST-OMVs were isolated through ultracentrifugation. The survival rate of DC was assessed with CCK-8 assay, and the stimulus concentration of OMVs was henceforth determined. The ultrastructural characteristics of DC loaded with OMVs were observed with transmission electron microscopy. The cytokine secretion, surface molecule expression and phagocytic capacity of DC were examined with flow cytometry. The DC induced and amplified in vitro displayed typical DC phenotype in morphological analysis and the purity of DC exceeded 85%. Transmission electron microscopy showed that there were large numbers of protrusions on the cell surface. After stimulation with ST-OMVs, it was observed that the dendritic structures on the surface of DC were reduced and a large number of phagolysosomes were found in the cytoplasm. In addition, increased numbers of mitochondria, swelling and typical apoptosis were observed. After treatment with ST-OMVs at 5 μg/mL and 10 μg/mL, the secretion of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) of DC increased significantly ( P<0.05). Furthermore, the immature DC could differentiate into mature DCs after stimulation with ST-OMVs, which were characterized by a decrease in phagocytic capacity ( P<0.05) and an upregulation of phenotypic markers ( P<0.05). ST-OMVs can stimulate DC to produce TNF-α and IL-1β and promote DC maturation and antigen presentation.

Alterations in β-Cell Sphingolipid Profile Associated with ER Stress and iPLA2β: Another Contributor to β-Cell Apoptosis in Type 1 Diabetes.

Type 1 diabetes (T1D) development, in part, is due to ER stress-induced β-cell apoptosis. Activation of the Ca2+-independent phospholipase A2 beta (iPLA2β) leads to the generation of pro-inflammatory eicosanoids, which contribute to β-cell death and T1D. ER stress induces iPLA2β-mediated generation of pro-apoptotic ceramides via neutral sphingomyelinase (NSMase). To gain a better understanding of the impact of iPLA2β on sphingolipids (SLs), we characterized their profile in β-cells undergoing ER stress. ESI/MS/MS analyses followed by ANOVA/Student’s t-test were used to assess differences in sphingolipids molecular species in Vector (V) control and iPLA2β-overexpressing (OE) INS-1 and Akita (AK, spontaneous model of ER stress) and WT-littermate (AK-WT) β-cells. As expected, iPLA2β induction was greater in the OE and AK cells in comparison with V and WT cells. We report here that ER stress led to elevations in pro-apoptotic and decreases in pro-survival sphingolipids and that the inactivation of iPLA2β restores the sphingolipid species toward those that promote cell survival. In view of our recent finding that the SL profile in macrophages—the initiators of autoimmune responses leading to T1D—is not significantly altered during T1D development, we posit that the iPLA2β-mediated shift in the β-cell sphingolipid profile is an important contributor to β-cell death associated with T1D.

Human umbilical cord mesenchymal stem cells reduce oxidative damage and apoptosis in diabetic nephropathy by activating Nrf2

BackgroundMesenchymal stem cells (MSCs) have a therapeutic effect on diabetic nephropathy (DN) but the underlying mechanism remains unclear. This study was conducted to investigate whether human umbilical cord-MSCs (hUCMSCs) can induce oxidative damage and apoptosis by activating Nrf2.MethodsWe used a type 2 diabetic rat model and a high-glucose and fat-stimulated human glomerular mesangial cell (hGMC) model. Western blotting, RT-qPCR, and TUNEL staining were performed on animal tissues and cultured cells. Nuclear expression of Nrf2 was detected in the renal tissue. Furthermore, Nrf2 siRNA was used to examine the effects of hUCMSCs on hGMCs. Finally, the effect of hUCMSCs on the Nrf2 upstream signalling pathway was investigated.ResultsAfter treatment with hUCMSCs, Nrf2 showed increased expression and nuclear translocation. After Nrf2-specific knockout in hGMCs, the protective effect of hUCMSCs on apoptosis induced by high-glucose and fat conditions was reduced. Activation of the PI3K signalling pathway may be helpful for ameliorating DN using hUCMSCs.ConclusionshUCMSCs attenuated renal oxidative damage and apoptosis in type 2 diabetes mellitus and Nrf2 activation is one of the important mechanisms of this effect. hUCMSCs show potential as drug targets for DN.

Retraction: “MicroRNA‐219 decreases hippocampal long‐term potentiation inhibition and hippocampal neuronal cell apoptosis in type 2 diabetes mellitus mice by suppressing the NMDAR signaling pathway,” by Zhang, L, Chen, Z‐W, Yang, S‐F, et al. CNS Neurosci Ther. 2019; 25: 69–77

Retraction: “MicroRNA‐219 decreases hippocampal long‐term potentiation inhibition and hippocampal neuronal cell apoptosis in type 2 diabetes mellitus mice by suppressing the NMDAR signaling pathway,” by Zhang, L, Chen, Z‐W, Yang, S‐F, et al. CNS Neurosci Ther. 2019; 25: 69–77

Nanomolar potency of imidazo[2,1-b]thiazole analogs as indoleamine 2,3-dioxygenase inhibitors.

Novel series of imidazo[2,1-b]thiazole analogs were designed, synthesized, and biologically evaluated as indoleamine 2,3-dioxygenase (IDO1) inhibitors. Imidazo[2,1-b]thiazoles 6, 7, and 8 showed inhibitory profiles against IDO1 at IC50 values of 68.48, 82.39, and 48.48 nM, respectively, compared with IDO5L at IC50 67.40 nM. Benzo[d]imidazo[2,1-b]thiazoles 17, 20, and 22 showed promising IDO1 inhibition at IC50 values of 53.58, 53.16, and 57.95 nM, respectively. Compound 7 showed a growth-inhibitory profile at GI of 39.33% against the MCF7 breast cancer cell line, while 8 proved lethal to ACHN renal cancer cells. Cells treated with compounds 17 and 22 showed a typical apoptosis pattern of DNA fragments that reflected the G0/G1, S, and G2/M phases of the cell cycle, together with a pre-G1 phase corresponding to apoptotic cells, which indicates that cell growth arrest occurred at the S phase. Molecular modeling simulations validated the potential of benzo[d]imidazo[2,1-b]thiazole analogs to chelate iron(III) within the IDO1 binding pocket and, hence, to have a better binding affinity via hydrophobic-hydrophobic interactions.

Avermectin induces toxic effects in insect nontarget cells involves DNA damage and its associated programmed cell death

Avermectin (AVM), is widely applied in the fields of agriculture, possess activities against mites and insects. AVM is generally thought to keep the GABA-related chloride channels open in insect cells. However, AVM induces cytotoxicity in non-neural cells still ambiguous. Here we evaluate the cytotoxicity and other mode of action of AVM in Spodoptera frugiperda (Sf9) cells. Our results showed that AVM suppressed the activity of Sf9 cells and induced programmed cell death. DNA damage of Sf9 cells was detected by alkaline comet assay and PARP. The cleavage of poly ADP-ribose polymerase (PARP) and DNA double-strand breaks demonstrated AVM induced DNA damage in Sf9 cells. In addition, a series of established cytotoxicity tests were conducted to explore the mechanism of AVM toxicity in Sf9 cells. Typical apoptosis changes were occurred including increasing the expression of Bax/Bcl-2 and the activation of caspase-9/-3. Subsequently, Western blotting was used to detected autophagy related proteins including LC3, Beclin1 and p62. We found that AVM upregulated LC3, Beclin1 expression and downregulated p62 expressions. Moreover, we found that AVM induced autophagy may through AMPK/mTOR-mediated autophagy pathway. These results showed that AVM-induced DNA damage and programmed cell death in Sf9 cells.

4-Propargyl-substituted 1H-pyrroles induce apoptosis and autophagy via extracellular signal-regulated signaling pathway in breast cancer.

Novel pyrrole derivatives (PDs) with propargyl units (1-7) were investigated for their anticancer activity on breast cancer cells. The MTT assay was used to assess the cell viability. Morphological changes in human breast cancer cells were visualized under a phase-contrast microscope. Apoptosis and autophagy were detected using the DNA fragmentation assay and staining by autophagic vacuoles, respectively. The levels of apoptosis- and autophagy-related proteins such as cytochrome c, Bcl-2, LC3-I/II were investigated by Western blot analysis. The effect of PDs on the ERK1/2 signaling pathway was investigated using specific inhibitors. All the tested PDs were found to be active in the range of 36.7 ± 0.2 to 459.7 ± 4.2 µM. Compounds 3 and 4 showed cytotoxic activity in breast cancer cells, but were found to be safer with lower cytotoxicity on human nontumorigenic epithelial breast cells. Compound 4 induced apoptosis, whereas compound 3 induced autophagy. Both compounds inhibited the ERK signaling pathway in breast cancer cells. The present study revealed that both synthesized PDs induced different programmed cell death types by inhibiting the ERK signaling pathway in two genotypically different breast cancer cells. Therefore, novel PDs might be promising anticancer agents for breast cancer therapy and further structural modifications of PDs may yield promising anticancer agents.

A first-in-human study of AO-176, a highly differentiated anti-CD47 antibody, in patients with advanced solid tumors.

2516 Background: AO-176 is a humanized IgG2 antibody that specifically targets CD47. Expressed by multiple tumor types, CD47 binds to signal regulatory protein a (SIRPa) on phagocytes, including macrophages and dendritic cells. The CD47-SIRPa complex results in a “don’t eat me” signal that allows the tumor to escape removal by the innate immune system, disabling the generation of an adaptive immune response. The differentiated mechanisms of action of AO-176 include promotion of phagocytosis, direct tumor cell killing through programmed cell death type III and induction of damage associated molecular patterns/immunogenic cell death, preferentially binding to tumor cells vs. normal cells, and enhanced binding at an acidic pH as found in tumor microenvironments. AO-176 has negligible binding to RBCs. Methods: In a phase 1/2 first-in-human study (NCT03834948) of AO-176, pts with advanced solid tumors associated with high CD47 expression and an ECOG PS of 0-1 were enrolled into escalating dose cohorts of AO-176 given IV every 7 days. Objectives included evaluation of safety, dose-limiting toxicity (DLT) and recommended phase 2 dose (RP2D), antitumor activity, pharmacokinetic (PK) parameters and exploratory biomarkers. Results: As of 4 Jan 2021, 27 pts were enrolled (median age 64 years; 67% female; 67% ECOG PS 1; median [range] of 4 [1-7] prior therapies for metastatic disease). Dose levels of 1, 3, 10, 20 and 20 (using step-up dosing) mg/kg were evaluated in &gt;250 infusions. Most common (&gt;10%) treatment-related adverse events (TRAEs) of any grade were thrombocytopenia and infusion-related reaction (IRR) (33% each), anemia (22%) with no evidence of hemolysis, nausea (19%), and fatigue (15%). The only G3+ TRAE occurring in &gt;10% of pts was asymptomatic, brief thrombocytopenia (22%). No platelet transfusions were given. DLTs included IRRs in 2 pts dosed at 20 mg/kg, and asymptomatic thrombocytopenia and a cerebrovascular accident in 1 pt each in the 20 mg/kg step-up cohort. The RP2D was 10 mg/kg. Implementation of additional pre-medication and a 6-hr infusion duration in cycle 1 eliminated subsequent IRRs. Dexamethasone tapering and shortening of the infusion duration to 2 hrs was successful in all pts after cycle 1. Interim PK analysis of AO-176 demonstrated consistent exposure with linear PK. The T1/2 was ̃5 days. One pt with endometrial carcinoma who had not responded to any of 4 prior systemic regimens had a confirmed PR and remains on study for &gt;1 year. 7 pts had SD as a best response, with 2 pts (endometrial carcinoma, gastric cancer) on study for &gt;6 mos. Conclusions: AO-176 is a well-tolerated, differentiated anti-CD47 therapeutic. Durable anti-tumor activity was observed. Evaluations of AO-176 in combination with paclitaxel in pts with select solid tumors (NCT03834948) and as a single-agent in pts with multiple myeloma (NCT04445701) are ongoing. Clinical trial information: NCT03834948.

Mechanisms of Beta-Cell Apoptosis in Type 2 Diabetes-Prone Situations and Potential Protection by GLP-1-Based Therapies.

Type 2 diabetes (T2D) is characterized by chronic hyperglycemia secondary to the decline of functional beta-cells and is usually accompanied by a reduced sensitivity to insulin. Whereas altered beta-cell function plays a key role in T2D onset, a decreased beta-cell mass was also reported to contribute to the pathophysiology of this metabolic disease. The decreased beta-cell mass in T2D is, at least in part, attributed to beta-cell apoptosis that is triggered by diabetogenic situations such as amyloid deposits, lipotoxicity and glucotoxicity. In this review, we discussed the molecular mechanisms involved in pancreatic beta-cell apoptosis under such diabetes-prone situations. Finally, we considered the molecular signaling pathways recruited by glucagon-like peptide-1-based therapies to potentially protect beta-cells from death under diabetogenic situations.