scholarly journals P53-independent restoration of p53 pathway in tumors with mutated p53 through ATF4 transcriptional modulation by ERK1/2 and CDK9

2020 ◽  
Author(s):  
Xiaobing Tian ◽  
Nagib Ahsan ◽  
Amriti Lulla ◽  
Avital Lev ◽  
Philip Abbosh ◽  
...  
Keyword(s):  
Cell Death ◽  
Bioinformatic Analysis ◽  
Drug Induced ◽  
P53 Pathway ◽  
Effector Genes ◽  
Cancer Field ◽  
Transcriptional Modulation ◽  
Metastasis Suppression ◽  
P53 Target Gene

AbstractA long-term goal in the cancer-field has been to develop strategies for treating p53-mutated tumors. A novel small-molecule, PG3-Oc, restores p53 pathway-signaling in tumor cells with mutant-p53, independently of p53/p73. PG3-Oc partially upregulates the p53-transcriptome (13.7% of public p53 target-gene dataset; 15.2% of in-house dataset) and p53-proteome (18%, HT29; 16%, HCT116-p53-/-). Bioinformatic analysis indicates critical p53-effectors of growth-arrest (p21), apoptosis (PUMA, DR5, Noxa), autophagy (DRAM1), and metastasis-suppression (NDRG1) are induced by PG3-Oc. ERK1/2- and CDK9-kinases are required to upregulate ATF4 by PG3-Oc which restores p53 transcriptomic-targets in cells without functional-p53. PG3-Oc represses MYC (ATF4-independent), and upregulates PUMA (ATF4-dependent) in mediating cell death. With largely nonoverlapping transcriptomes, induced-ATF4 restores p53 transcriptomic targets in drug-treated cells including functionally important mediators such as PUMA and DR5. Our results demonstrate novel p53-independent drug-induced molecular reprogramming involving ERK1/2, CDK9, and ATF4 to restore upregulation of p53 effector genes required for cell death and tumor suppression.

scholarly journals Long-Term Exposure to Nanosized TiO2 Triggers Stress Responses and Cell Death Pathways in Pulmonary Epithelial Cells

2021 ◽  
Vol 22 (10) ◽  
pp. 5349
Author(s):  
Mayes Alswady-Hoff ◽  
Johanna Samulin Erdem ◽  
Santosh Phuyal ◽  
Oskar Knittelfelder ◽  
Animesh Sharma ◽  
...  
Keyword(s):  
Cell Death ◽  
Epithelial Cells ◽  
Health Effects ◽  
Stress Responses ◽  
Cell Stress ◽  
Lipid Classes ◽  
Long Term Effects ◽  
Cell Death Pathways ◽  
Pulmonary Epithelial Cells

There is little in vitro data available on long-term effects of TiO2 exposure. Such data are important for improving the understanding of underlying mechanisms of adverse health effects of TiO2. Here, we exposed pulmonary epithelial cells to two doses (0.96 and 1.92 µg/cm2) of TiO2 for 13 weeks and effects on cell cycle and cell death mechanisms, i.e., apoptosis and autophagy were determined after 4, 8 and 13 weeks of exposure. Changes in telomere length, cellular protein levels and lipid classes were also analyzed at 13 weeks of exposure. We observed that the TiO2 exposure increased the fraction of cells in G1-phase and reduced the fraction of cells in G2-phase, which was accompanied by an increase in the fraction of late apoptotic/necrotic cells. This corresponded with an induced expression of key apoptotic proteins i.e., BAD and BAX, and an accumulation of several lipid classes involved in cellular stress and apoptosis. These findings were further supported by quantitative proteome profiling data showing an increase in proteins involved in cell stress and genomic maintenance pathways following TiO2 exposure. Altogether, we suggest that cell stress response and cell death pathways may be important molecular events in long-term health effects of TiO2.

scholarly journals Co-delivery of IOX1 and doxorubicin for antibody-independent cancer chemo-immunotherapy

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jing Liu ◽  
Zhihao Zhao ◽  
Nasha Qiu ◽  
Quan Zhou ◽  
Guowei Wang ◽  
...  
Keyword(s):  
Cell Death ◽  
T Cell ◽  
Programmed Cell Death ◽  
Memory Function ◽  
Histone Demethylase ◽  
Cell Dysfunction ◽  
T Cell Infiltration ◽  
Programmed Cell Death 1 ◽  
T Cell Dysfunction

AbstractAnti-programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) antibodies are currently used in the clinic to interupt the PD-1/PD-L1 immune checkpoint, which reverses T cell dysfunction/exhaustion and shows success in treating cancer. Here, we report a histone demethylase inhibitor, 5-carboxy-8-hydroxyquinoline (IOX1), which inhibits tumour histone demethylase Jumonji domain-containing 1A (JMJD1A) and thus downregulates its downstream β-catenin and subsequent PD-L1, providing an antibody-independent paradigm interrupting the PD-1/PD-L1 checkpoint. Synergistically, IOX1 inhibits cancer cells’ P-glycoproteins (P-gp) through the JMJD1A/β-catenin/P-gp pathway and greatly enhances doxorubicin (DOX)-induced immune-stimulatory immunogenic cell death. As a result, the IOX1 and DOX combination greatly promotes T cell infiltration and activity and significantly reduces tumour immunosuppressive factors. Their liposomal combination reduces the growth of various murine tumours, including subcutaneous, orthotopic, and lung metastasis tumours, and offers a long-term immunological memory function against tumour rechallenging. This work provides a small molecule-based potent cancer chemo-immunotherapy.

scholarly journals Inhibition of mitochondrial carrier homolog 2 (MTCH2) suppresses tumor invasion and enhances sensitivity to temozolomide in malignant glioma

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Qiuyun Yuan ◽  
Wanchun Yang ◽  
Shuxin Zhang ◽  
Tengfei Li ◽  
Mingrong Zuo ◽  
...  
Keyword(s):  
Cell Death ◽  
Malignant Glioma ◽  
Aerobic Glycolysis ◽  
Underlying Mechanism ◽  
Bioinformatic Analysis ◽  
Mitochondrial Outer Membrane ◽  
Invasion Pathways ◽  
Western Blots ◽  
Mitochondrial Functions ◽  
Dependent Cell

Abstract Background Malignant glioma exerts a metabolic shift from oxidative phosphorylation (OXPHOs) to aerobic glycolysis, with suppressed mitochondrial functions. This phenomenon offers a proliferation advantage to tumor cells and decrease mitochondria-dependent cell death. However, the underlying mechanism for mitochondrial dysfunction in glioma is not well elucidated. MTCH2 is a mitochondrial outer membrane protein that regulates mitochondrial metabolism and related cell death. This study aims to clarify the role of MTCH2 in glioma. Methods Bioinformatic analysis from TCGA and CGGA databases were used to investigate the association of MTCH2 with glioma malignancy and clinical significance. The expression of MTCH2 was verified from clinical specimens using real-time PCR and western blots in our cohorts. siRNA-mediated MTCH2 knockdown were used to assess the biological functions of MTCH2 in glioma progression, including cell invasion and temozolomide-induced cell death. Biochemical investigations of mitochondrial and cellular signaling alternations were performed to detect the mechanism by which MTCH2 regulates glioma malignancy. Results Bioinformatic data from public database and our cohort showed that MTCH2 expression was closely associated with glioma malignancy and poor patient survival. Silencing of MTCH2 expression impaired cell migration/invasion and enhanced temozolomide sensitivity of human glioma cells. Mechanistically, MTCH2 knockdown may increase mitochondrial OXPHOs and thus oxidative damage, decreased migration/invasion pathways, and repressed pro-survival AKT signaling. Conclusion Our work establishes the relationship between MTCH2 expression and glioma malignancy, and provides a potential target for future interventions.

scholarly journals Aurintricarboxylic acid rescues PC12 cells and sympathetic neurons from cell death caused by nerve growth factor deprivation: correlation with suppression of endonuclease activity.

1991 ◽  
Vol 115 (2) ◽  
pp. 461-471 ◽  
Author(s):  
A Batistatou ◽  
L A Greene
Keyword(s):  
Cell Death ◽  
Nerve Growth Factor ◽  
Pc12 Cells ◽  
Sympathetic Neurons ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Endonuclease Activity ◽  
Term Survival ◽  
Serum Free

Past studies have shown that serum-free cultures of PC12 cells are a useful model system for studying the neuronal cell death which occurs after neurotrophic factor deprivation. In this experimental paradigm, nerve growth factor (NGF) rescues the cells from death. It is reported here that serum-deprived PC12 cells manifest an endonuclease activity that leads to internucleosomal cleavage of their cellular DNA. This activity is detected within 3 h of serum withdrawal and several hours before any morphological sign of cell degeneration or death. NGF and serum, which promote survival of the cells, inhibit the DNA fragmentation. Aurintricarboxylic acid (ATA), a general inhibitor of nucleases in vitro, suppresses the endonuclease activity and promotes long-term survival of PC12 cells in serum-free cultures. This effect appears to be independent of macromolecular synthesis. In addition, ATA promotes long-term survival of cultured sympathetic neurons after NGF withdrawal. ATA neither promotes nor maintains neurite outgrowth. It is hypothesized that the activation of an endogenous endonuclease could be responsible for neuronal cell death after neurotrophic factor deprivation and that growth factors could promote survival by leading to inhibition of constitutively present endonucleases.

Carbamazepine-induced delayed-onset agranulocytosis in a case of bipolar disorder with Kikuchi’s disease

2021 ◽  
Vol 14 (6) ◽  
pp. e241973
Author(s):  
Cebasta Irudayaraj ◽  
Raviteja Innamuri ◽  
Dheeraj Kattula
Keyword(s):  
Bipolar Disorder ◽  
Psychiatric Symptoms ◽  
Drug Effects ◽  
Significant Loss ◽  
Drug Induced ◽  
Kikuchi’S Disease ◽  
Delayed Onset ◽  
Loss Of Weight ◽  
Kikuchi's Disease

A 48-year-old man who is a known case of bipolar disorder was maintaining well on a combination of carbamazepine and quetiapine for 3 years until he developed fever, severe leucopenia and lymphadenopathy, along with significant loss of weight and appetite. A thorough investigation revealed Kikuchi’s disease as a likely histological diagnosis. Carbamazepine was discontinued and quetiapine was titrated for the management of psychiatric symptoms. The patient gradually made good recovery following discontinuation of carbamazepine and the diagnosis of drug-induced myelosuppression was retained. Clinicians need to be aware of the adverse effects of medications being used for long-term prophylaxis and other possible conditions that may change the course of drug effects.

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