Mechanical insights into the regulation of programmed cell death by p53 via mitochondria

HMGA2 promotes resistance against paclitaxel by targeting the p53 signaling pathway in colorectal cancer cells

Colorectal cancer is one of the most common malignancies and ranks second in terms of cancer-related mortality worldwide due to its metastasis, drug resistance, and reoccurrence. High-mobility gene group A2 (HMGA2) is overexpressed in colorectal cancer, contributing to the aggressiveness of tumor malignance, and promotes drug resistance in many types of cancer. However, the underlying molecular mechanism of HMGA2 is yet to be elucidated. In this study, we showed that HMGA2 is overexpressed in colorectal cancer tissue, and knockdown of HMGA2 significantly inhibited colorectal cancer cell growth and migratory capability. HMGA2 regulates the cancer cell response to a widely used anti-cancer drug, paclitaxel (PTX). HMGA2 knockdown increased cell death, whereas HMGA2 overexpression decreased cell death after PTX treatment. Furthermore, lower reactive oxygen species (ROS) levels and mitochondrial potential were detected in HMGA2 overexpression cells after PTX treatment. However, HMGA2 knockdown produced the opposite effect. RNA sequencing showed a p53 signaling pathway-dependent regulation in HMGA2 knockdown cells. Combined with p53 inhibitors and HMGA2 knockdown, a synergetic effect of more cell death was observed in colorectal cancer cells after PTX treatment. Thus, we showed that HMGA2 can activate p53 signaling to regulate colorectal cancer cell death after PTX treatment. Altogether, our results reveal novel insights into the molecular mechanisms underlying HMGA2-mediated cancer cell resistance against PTX and highlight the potential of targeting HMGA2 and p53 signaling for the therapeutic investigation of colorectal cancer.

KDM7A-DT induces genotoxic stress, tumorigenesis, and progression of p53 missense mutation-associated invasive breast cancer

Stress-induced promoter-associated and antisense lncRNAs (si-paancRNAs) originate from a reservoir of oxidative stress (OS)-specific promoters via RNAPII pausing-mediated divergent antisense transcription. Several studies have shown that the KDM7A divergent transcript gene (KDM7A-DT), which encodes a si-paancRNA, is overexpressed in some cancer types. However, the mechanisms of this overexpression and its corresponding roles in oncogenesis and cancer progression are poorly understood. We found that KDM7A-DT expression is correlated with highly aggressive cancer types and specific inherently determined subtypes (such as ductal invasive breast carcinoma (BRCA) basal subtype). Its regulation is determined by missense TP53 mutations in a subtype-specific context. KDM7A-DT transcribes several intermediate-sized ncRNAs and a full-length transcript, exhibiting distinct expression and localization patterns. Overexpression of KDM7A-DT upregulates TP53 protein expression and H2AX phosphorylation in nonmalignant fibroblasts, while in semi-transformed fibroblasts, OS superinduces KDM7A-DT expression in a TP53-dependent manner. KDM7A-DT knockdown and gene expression profiling in TP53-missense mutated luminal A BRCA variant, where it is abundantly expressed, indicate its significant role in cancer pathways. Endogenous over-expression of KDM7A-DT inhibits DNA damage response/repair (DDR/R) via the TP53BP1-mediated pathway, reducing apoptosis and promoting G2/M checkpoint arrest. Higher KDM7A-DT expression in BRCA is associated with KDM7A-DT locus gain/amplification, higher histologic grade, aneuploidy, hypoxia, immune modulation scores, and activation of the c-myc pathway. Higher KDM7A-DT expression is associated with relatively poor survival outcomes in patients with luminal A or Basal subtypes. In contrast, it is associated with favorable outcomes in patients with HER2+ER- or luminal B subtypes. KDM7A-DT levels are coregulated with critical transcripts and proteins aberrantly expressed in BRCA, including those involved in DNA repair via non-homologous end joining and epithelial-to-mesenchymal transition pathway. In summary, KDM7A-DT and its si-lncRNA exhibit several intrinsic biological and clinical characteristics that suggest important roles in invasive BRCA and its subtypes. KDM7A-DT-defined mRNA and protein subnetworks offer resources for identifying clinically relevant RNA-based signatures and prospective targets for therapeutic intervention.

The Autoxidized Mixture of (-)-Epicatechin Contains Procyanidins and Shows Antiproliferative and Apoptotic Activity in Breast Cancer Cells

For this study, procyanidins generated through the autoxidation of (-)-epicatechin (Flavan-3-ol) under mildly acidic conditions (pH = 6.0) were characterized with ultra high-performance liquid chromatography (UHPLC) coupled with tandem mass spectrometry (MS/MS). Two procyanidins (types A and B) and a mix of oligomers were generated through the autoxidation of (-)-epicatechin. The antiproliferative activity of this mixture of procyanidins on MDA-MB-231, MDA-MB-436, and MCF-7 breast cancer cells was evaluated. The results indicate that the procyanidin mixture inhibited the proliferation of breast cancer cells, where the activity of the procyanidin mixture was stronger than that of (-)-epicatechin. Moreover, the mechanism underlying the antiproliferative activity of procyanidins was investigated. The resulting data demonstrate that the procyanidins induced apoptotic cell death in a manner selective to cancerous cells. In particular, they caused the activation of intrinsic and extrinsic apoptotic pathways in the breast cancer cells. The findings obtained in this study demonstrate that the generation of procyanidins in vitro by the autoxidation of (-)-epicatechin has potential for the development of anti-breast cancer agents.

Protein tyrosine phosphatase PTPRO represses lung adenocarcinoma progression by inducing mitochondria-dependent apoptosis and restraining tumor metastasis

Emerging evidence indicates that protein activities regulated by receptor protein tyrosine phosphatases (RPTPs) are crucial for a variety of cellular processes, such as proliferation, apoptosis, and immunological response. Protein tyrosine phosphatase receptor type O (PTPRO), an RPTP, has been revealed as a putative suppressor in the development of particular tumors. However, the function and the underlying mechanisms of PTPRO in regulating of lung adenocarcinoma (LUAD) are not well understood. In this view, the present work investigated the role of PTPRO in LUAD. Analysis of 90 pairs of clinical LUAD specimens revealed significantly lower PTPRO levels in LUAD compared with adjacent non-tumor tissue, as well as a negative correlation of PTPRO expression with tumor size and TNM stage. Survival analyses demonstrated that PTPRO level can help stratify the prognosis of LUAD patients. Furthermore, PTPRO overexpression was found to suppress the progression of LUAD both in vitro and in vivo by inducing cell death via mitochondria-dependent apoptosis, downregulating protein expression of molecules (Bcl-2, Bax, caspase 3, cleaved-caspase 3/9, cleaved-PARP and Bid) essential in cell survival. Additionally, PTPRO decreased LUAD migration and invasion by regulating proteins involved in the epithelial-to-mesenchymal transition (E-cadherin, N-cadherin, and Snail). Moreover, PTPRO was shown to restrain JAK2/STAT3 signaling pathways. Expression of PTPRO was negatively correlated with p-JAK2, p-STAT3, Bcl-2, and Snail levels in LUAD tumor samples. Furthermore, the anti-tumor effect of PTPRO in LUAD was significant but compromised in STAT3-deficient cells. These data support the remarkable suppressive role of PTPRO in LUAD, which may represent a viable therapeutic target for LUAD patients.

Emerging role and therapeutic implications of p53 in intervertebral disc degeneration

Lower back pain (LBP) is a common degenerative musculoskeletal disease that imposes a huge economic burden on both individuals and society. With the aggravation of social aging, the incidence of LBP has increased globally. Intervertebral disc degeneration (IDD) is the primary cause of LBP. Currently, IDD treatment strategies include physiotherapy, medication, and surgery; however, none can address the root cause by ending the degeneration of intervertebral discs (IVDs). However, in recent years, targeted therapy based on specific molecules has brought hope for treating IDD. The tumor suppressor gene p53 produces a transcription factor that regulates cell metabolism and survival. Recently, p53 was shown to play an important role in maintaining IVD microenvironment homeostasis by regulating IVD cell senescence, apoptosis, and metabolism by activating downstream target genes. This study reviews research progress regarding the potential role of p53 in IDD and discusses the challenges of targeting p53 in the treatment of IDD. This review will help to elucidate the pathogenesis of IDD and provide insights for the future development of precision treatments.

p53 at the crossroad between mitochondrial reactive oxygen species and necroptosis

p53 is a redox-sensitive transcription factor that can regulate multiple cell death programs through different signaling pathways. In this review, we assess the role of p53 in the regulation of necroptosis, a programmed form of lytic cell death highly involved in the pathophysiology of multiple diseases. In particular, we focus on the role of mitochondrial reactive oxygen species (mtROS) as essential contributors to modulate necroptosis execution through p53. The enhanced generation of mtROS during necroptosis is critical for the correct interaction between receptor-interacting serine/threonine-protein kinase 1 (RIPK1) and 3 (RIPK3), two key components of the functional necrosome. p53 controls the occurrence of necroptosis by modulating the levels of mitochondrial H2O2 via peroxiredoxin 3 and sulfiredoxin. Furthermore, in response to increased levels of H2O2, p53 upregulates the long non-coding RNA necrosis-related factor, favoring the translation of RIPK1 and RIPK3. In parallel, a fraction of cytosolic p53 migrates into mitochondria, a process notably involved in necroptosis execution via its interaction with the mitochondrial permeability transition pore. In conclusion, p53 is located at the intersection between mtROS and the necroptosis machinery, making it a key protein to orchestrate redox signaling during necroptosis.

Oxidative stress as a key modulator of cell fate decision in osteoarthritis and osteoporosis: a narrative review

During aging and after traumatic injuries, cartilage and bone cells are exposed to various pathophysiologic mediators, including reactive oxygen species (ROS), damage-associated molecular patterns, and proinflammatory cytokines. This detrimental environment triggers cellular stress and subsequent dysfunction, which not only contributes to the development of associated diseases, that is, osteoporosis and osteoarthritis, but also impairs regenerative processes. To counter ROS-mediated stress and reduce the overall tissue damage, cells possess diverse defense mechanisms. However, cellular antioxidative capacities are limited and thus ROS accumulation can lead to aberrant cell fate decisions, which have adverse effects on cartilage and bone homeostasis. In this narrative review, we address oxidative stress as a major driver of pathophysiologic processes in cartilage and bone, including senescence, misdirected differentiation, cell death, mitochondrial dysfunction, and impaired mitophagy by illustrating the consequences on tissue homeostasis and regeneration. Moreover, we elaborate cellular defense mechanisms, with a particular focus on oxidative stress response and mitophagy, and briefly discuss respective therapeutic strategies to improve cell and tissue protection.

JNK Cascade-Induced Apoptosis-A Unique Role in GqPCR Signaling

The response of cells to extracellular signals is mediated by a variety of intracellular signaling pathways that determine stimulus-dependent cell fates. One such pathway is the cJun-N-terminal Kinase (JNK) cascade, which is mainly involved in stress-related processes. The cascade transmits its signals via a sequential activation of protein kinases, organized into three to five tiers. Proper regulation is essential for securing a proper cell fate after stimulation, and the mechanisms that regulate this cascade may involve the following: (1) Activatory or inhibitory phosphorylations, which induce or abolish signal transmission. (2) Regulatory dephosphorylation by various phosphatases. (3) Scaffold proteins that bring distinct components of the cascade in close proximity to each other. (4) Dynamic change of subcellular localization of the cascade's components. (5) Degradation of some of the components. In this review, we cover these regulatory mechanisms and emphasize the mechanism by which the JNK cascade transmits apoptotic signals. We also describe the newly discovered PP2A switch, which is an important mechanism for JNK activation that induces apoptosis downstream of the Gq protein coupled receptors. Since the JNK cascade is involved in many cellular processes that determine cell fate, addressing its regulatory mechanisms might reveal new ways to treat JNK-dependent pathologies.

Different Roles of Apoptosis and Autophagy in the Development of Human Colorectal Cancer

Colorectal cancer (CRC) remains a major life-threatening malignancy, despite numerous therapeutic and screening attempts. Apoptosis and autophagy are two processes that share common signaling pathways, are linked by functional relationships and have similar protein components. During the development of cancer, the two processes can trigger simultaneously in the same cell, causing, in some cases, an inhibition of autophagy by apoptosis or apoptosis by autophagy. Malignant cells that have accumulated genetic alterations can take advantage of any alterations in the apoptotic process and as a result, progress easily in the cancerous transformation. Autophagy often plays a suppressive role during the initial stages of carcinogenicity, while in the later stages of cancer development it can play a promoting role. It is extremely important to determine the regulation of this duality of autophagy in the development of CRC and to identify the molecules involved, as well as the signals and the mechanisms behind it. All the reported experimental results indicate that, while the antagonistic effects of autophagy and apoptosis occur in an adverse environment characterized by deprivation of oxygen and nutrients, leading to the formation and development of CRC, the effects of promotion and collaboration usually involve an auxiliary role of autophagy compared to apoptosis. In this review, we elucidate the different roles of autophagy and apoptosis in human CRC development.

Activation of P53 pathway contributes to Xenopus hybrid inviability

Hybrid incompatibility as a kind of reproductive isolation contributes to speciation. The nucleocytoplasmic incompatibility between Xenopus tropicalis eggs and Xenopus laevis sperm (te×ls) leads to specific loss of paternal chromosomes 3L and 4L. The hybrids die before gastrulation, of which the lethal causes remain largely unclear. Here, we show that the activation of the tumor suppressor protein P53 at late blastula stage contributes to this early lethality. We find that in stage 9 embryos, P53-binding motif is the most enriched one in the up-regulated Assay for Transposase-Accessible Chromatin with high-throughput sequencing (ATAC-seq) peaks between te×ls and wild-type X. tropicalis controls, which correlates with an abrupt stabilization of P53 protein in te×ls hybrids at stage 9. Inhibition of P53 activity via either tp53 knockout or overexpression of a dominant-negative P53 mutant or Murine double minute 2 proto-oncogene (Mdm2), a negative regulator of P53, by mRNA injection can rescue the te×ls early lethality. Our results suggest a causal function of P53 on hybrid lethality prior to gastrulation.

In Response to Precision Medicine: Current Subcellular Targeting Strategies for Cancer Therapy

Emerging as a potent anticancer treatment, subcellular targeted cancer therapy has drawn increasing attention, bringing great opportunities for clinical application. Here, two targeting strategies for four main subcellular organelles (mitochondria, lysosome, endoplasmic reticulum, and nucleus), including molecule- and nanomaterial (inorganic nanoparticles, micelles, organic polymers, and others)-based targeted delivery or therapeutic strategies, are summarized. Phototherapy, chemotherapy, radiotherapy, immunotherapy, and "all-in-one" combination therapy are among the strategies covered in detail. Such materials are constructed based on the specific properties and relevant mechanisms of organelles, enabling the elimination of tumors by inducing dysfunction in the corresponding organelles or destroying specific structures. The challenges faced by organelle-targeting cancer therapies are also summarized. Looking forward, a paradigm for organelle-targeting therapy with enhanced therapeutic efficacy compared to current clinical approaches is envisioned.

Microplastics Exacerbate Cadmium-Induced Kidney Injury by Enhancing Oxidative Stress, Autophagy, Apoptosis, and Fibrosis

Cadmium (Cd) is a potential pathogenic factor in the urinary system that is associated with various kidney diseases. Microplastics (MPs), comprising of plastic particles less than 5 mm in diameter, are a major carrier of contaminants. We applied 10 mg/L particle 5 μm MPs and 50 mg/L CdCl2 in water for three months in vivo assay to assess the damaging effects of MPs and Cd exposure on the kidney. In vivo tests showed that MPs exacerbated Cd-induced kidney injury. In addition, the involvement of oxidative stress, autophagy, apoptosis, and fibrosis in the damaging effects of MPs and Cd on mouse kidneys were investigated. The results showed that MPs aggravated Cd-induced kidney injury by enhancing oxidative stress, autophagy, apoptosis, and fibrosis. These findings provide new insights into the toxic effects of MPs on the mouse kidney.

Elevation of effective p53 expression sensitizes wild-type p53 breast cancer cells to CDK7 inhibitor THZ1

Background

The cyclin-dependent kinase 7 (CDK7) inhibitor THZ1 represses multiple cancer cells. However, its tumor-repressive efficiency in wild-type p53 breast cancer cells remains controversial.

Methods

We conducted various assays, including CCK8, colony formation, flow cytometry, western blotting, and lactate dehydrogenase release detection, to clarify whether p53 elevation sensitizes breast cancer cells to THZ1.

Results

We found that upregulating functional p53 contributes to the increased sensitivity of breast cancer cells to THZ1. Increased THZ1 sensitivity requires active p53 and an intact p53 pathway, which was confirmed by introducing exogenous wild-type p53 and the subsequent elevation of THZ1-mediated tumor suppression in breast cancer cells carrying mutant p53. We confirmed that p53 accumulates in the nucleus and mitochondria during cell death. Furthermore, we identified extensive transcriptional disruption, rather than solely CDK7 inhibition, as the mechanism underlying the nutlin-3 and THZ1-induced death of breast cancer cells. Finally, we observed the combined nutlin-3 and THZ1 treatment amplified gasdermin E cleavage.

Conclusion

Enhanced sensitivity of breast cancer cells to THZ1 can be achieved by increasing effective p53 expression. Our approach may serve as a potential treatment for patients with breast cancer resistant to regular therapies.

p53 drives necroptosis via downregulation of sulfiredoxin and peroxiredoxin 3

Mitochondrial dysfunction is a key contributor to necroptosis. We have investigated the contribution of p53, sulfiredoxin, and mitochondrial peroxiredoxin 3 to necroptosis in acute pancreatitis. Late during the course of pancreatitis, p53 was localized in mitochondria of pancreatic cells undergoing necroptosis. In mice lacking p53, necroptosis was absent, and levels of PGC-1α, peroxiredoxin 3 and sulfiredoxin were upregulated. During the early stage of pancreatitis, prior to necroptosis, sulfiredoxin was upregulated and localized into mitochondria. In mice lacking sulfiredoxin with pancreatitis, peroxiredoxin 3 was hyperoxidized, p53 localized in mitochondria, and necroptosis occurred faster; which was prevented by Mito-TEMPO. In obese mice, necroptosis occurred in pancreas and adipose tissue. The lack of p53 up-regulated sulfiredoxin and abrogated necroptosis in pancreas and adipose tissue from obese mice. We describe here a positive feedback between mitochondrial H₂O₂ and p53 that downregulates sulfiredoxin and peroxiredoxin 3 leading to necroptosis in inflammation and obesity.

Mitochondrial sirtuin 3 and various cell death modalities

Sirtuin 3, a member of the mammalian sirtuin family of proteins, is involved in the regulation of multiple processes in cells. It is a major mitochondrial NAD⁺-dependent deacetylase with a broad range of functions, such as regulation of oxidative stress, reprogramming of tumor cell energy pathways, and metabolic homeostasis. One of the intriguing functions of sirtuin 3 is the regulation of mitochondrial outer membrane permeabilization, a key step in apoptosis initiation/progression. Moreover, sirtuin 3 is involved in the execution of various cell death modalities, which makes sirtuin 3 a possible regulator of crosstalk between them. This review is focused on the role of sirtuin 3 as a target for tumor cell elimination and how mitochondria and reactive oxygen species (ROS) are implicated in this process.

Tumor cell-derived extracellular vesicles for breast cancer specific delivery of therapeutic P53

Breast cancer has consistently had the highest incidence among women in the world. Tumor cell-derived extracellular vesicles (EV) have been leveraged as drug carriers for cancer treatment. Herein, we developed an efficient theranostic platform for breast cancer-specific delivery of lipophilic triphenylphosphonium (TPP)-modified therapeutic recombinant P53 proteins (TPP/P53) by breast cancer cell-derived EVs. We observed that the EVs were routinely captured by their patent cells, so when, TPP/P53 was loaded into the EVs (TPP/P53@EVs), TPP/P53 was targeted to the mitochondria of breast cancer cells, where it caused signal amplification and induced the death of breast cancer cells. Our findings demonstrated that the TPP/P53@EVs showed good tumor-targeting capability and efficiently destroyed the tumor tissues without any obvious toxicity in vivo. Therefore, our TPP/P53@EVs might provide a "drug-free" strategy for future applications in breast cancer therapy.

Piracetam attenuates cyclophosphamide-induced hepatotoxicity in rats: Amelioration of necroptosis, pyroptosis and caspase-dependent apoptosis

AIMS

Cyclophosphamide (Cyclo) is an immunosuppressive and antineoplastic agent. The clinical use of Cyclo is limited by significant hepatotoxicity. Piracetam (Pira) is used to improve cognitive function. Pira possesses diverse physiological functions; however, the exact mechanisms of its activity are still non-elucidated.

MAIN METHODS

Forty rats were allocated in four groups. 1st group comprised normal rats; the remaining groups received single Cyclo dose (200 mg/kg/i.p.) on the experiment's 15th day. 2nd group comprised Cyclo-control rats. 3rd & 4th groups received Pira (100 & 300 mg/kg body weight) for 15 days.

KEY FINDINGS

Cyclo administration resulted in deterioration of serum liver function tests and elevation of hepatic tissue concentration of P53, Nf-kβ, apoptosis-inducing factor-1, NLRP3 inflammasome, Bax; gene expression of receptor-induced protein-1 along with reduction of hepatic Bcl-2 concentration. Bax/Bcl-2 ratio headed for apoptosis. Cyclo administration also resulted in a severe deterioration of the hepatic histopathological picture and significant immunohistochemical expression of caspase-3, tumor necrosis factor-alpha (TNF-α) and Cyclooxygenase-2 (COX-2) in hepatic tissues versus the normal group. Pira significantly improved all the aforementioned parameters, reallocating the Bax/Bcl-2 ratio to anti-apoptosis. Moreover, Pira treatment amended Cyclo-induced histopathological abnormalities and significantly reduced caspase-3, TNF-α plus COX-2 immunoreactivity in hepatic tissues.

SIGNIFICANCE

The present work is the first to link Cyclo-induced hepatotoxicity to the activation of caspase-independent apoptosis (necroptosis), pyroptosis and caspase-dependent apoptosis signaling pathways. Pira treatment significantly ameliorated Cyclo-induced hepatotoxicity mainly via the amendment of necroptotic, pyroptotic and caspase-dependent apoptotic changes along with the histopathological deformities in rats' hepatic tissues.

Necroptosis-Associated lncRNA Prognostic Model and Clustering Analysis: Prognosis Prediction and Tumor-Infiltrating Lymphocytes in Breast Cancer

Necroptosis plays an important role in tumor genesis and progression. This study aims to identify necroptosis-related lncRNAs (NR-lncRNAs) in breast cancer (BC), and their prognostic value and relationship with the tumor immune environment (TIE) through bioinformatics. Methods. A total of 67 necroptosis-related genes (NRGs) are retrieved, and 13 prognostically relevant NR-lncRNAs are identified by co-expression and Univariate Cox regression analyses. After unsupervised clustering analysis, the patients are classified into three clusters, and their survival and immune infiltration are compared. Lasso regression analysis is conducted to construct a prognostic model using eight lncRNAs (USP30-AS1, AC097662.1, AC007686.3, AL133467.1, AP006284.1, NDUFA6-DT, LINC01871, AL135818.1). The model is validated by Kaplan-Meier survival analysis, Multivariate Cox regression analysis, and receiver-operating characteristic (ROC) curves. Correlation analysis is useful to identify associations between risk scores and clinicopathological features. GSEA, drug prediction, and immune checkpoints analysis are further used to differentiate between the risk groups. Results. The C3 cluster has longer overall survival (OS) and the highest immune score, indicative of an immunologically hot tumor that may be sensitive to immunotherapy. Furthermore, the OS is significantly higher in the low-risk group, even after dividing the patients into subgroups with different clinical characteristics. The area under the ROC curve (AUC) for 1-, 3-, and 5-year survival in the training set are 0.761, 0.734, and 0.664, respectively, which indicate the moderate predictive performance of the model. Conclusion. NR-lncRNAs can predict the prognosis of BC, distinguish between hot and cold tumors, and are potential predictive markers of the immunotherapy response.

Functional Role of microRNAs in Regulating Cardiomyocyte Death

microRNAs (miRNA, miRs) play crucial roles in cardiovascular disease regulating numerous processes, including inflammation, cell proliferation, angiogenesis, and cell death. Herein, we present an updated and comprehensive overview of the functional involvement of miRs in the regulation of cardiomyocyte death, a central event in acute myocardial infarction, ischemia/reperfusion, and heart failure. Specifically, in this systematic review we are focusing on necrosis, apoptosis, and autophagy.

Multiple subcellular localizations and functions of protein kinase Cδ in liver cancer

Protein kinase Cδ (PKCδ) is a member of the PKC family, and its implications have been reported in various biological and cancerous processes, including cell proliferation, cell death, tumor suppression, and tumor progression. In liver cancer cells, accumulating reports show the bi-functional regulation of PKCδ in cell death and survival. PKCδ function is defined by various factors, such as phosphorylation, catalytic domain cleavage, and subcellular localization. PKCδ has multiple intracellular distribution patterns, ranging from the cytosol to the nucleus. We recently found a unique extracellular localization of PKCδ in liver cancer and its growth factor-like function in liver cancer cells. In this review, we first discuss the structural features of PKCδ and then focus on the functional diversity of PKCδ based on its subcellular localization, such as the nucleus, cell surface, and extracellular space. These findings improve our knowledge of PKCδ involvement in the progression of liver cancer.

The potential roles of p53 signaling reactivation in pancreatic cancer therapy

Globally, pancreatic cancer (PC) is a common and highly malignant gastrointestinal tumor that is characterized by an insidious onset and ready metastasis and recurrence. Over recent decades, the incidence of PC has been increasing on an annual basis; however, the pathogenesis of this condition remains enigmatic. PC is not sensitive to radio- or chemotherapy, and except for early surgical resection, there is no curative treatment regime; consequently, the prognosis for patients with PC is extremely poor. Transcription factor p53 is known to play key roles in many important biological processes in vertebrates, including normal cell growth, differentiation, cell cycle progression, senescence, apoptosis, metabolism, and DNA damage repair. However, there is a significant paucity of basic and clinical studies to describe how p53 gene mutations or protein dysfunction facilitate the occurrence, progression, invasion, and resistance to therapy, of malignancies, including PC. Herein, we describe the involvement of p53 signaling reactivation in PC treatment as well as its underlying molecular mechanisms, thereby providing useful insights for targeting p53-related signal pathways in PC therapy.

Neuroprotective Effects of Deproteinized Calf Serum in Ischemic Stroke

Deproteinized calf serum (DCS) may have neuroprotective effects after ischemic stroke. The aim of this study is to investigate whether and how the DCS inhibits neuronal injury following cerebral ischemia. Rats were subjected to 2 h transient middle cerebral artery occlusion (MCAO). One dose of 0.125 mg/gbw DCS was given immediately after reperfusion. Neurological deficit and infarct volume at 24 h post-MCAO in DCS-treated rats were lower than those in vehicle-treated rats (p < 0.0005). In cultured neurons model, cell viability was decreased, and apoptosis was increased by oxygen-glucose deprivation/reperfusion (OGD/R) (p < 0.0005). These effects of OGD/R were attenuated by 0.4 μg/μl DCS (p < 0.05) that were validated by CCK8 cell viability assay, phycoerythrin–Annexin V Apoptosis Detection assay, and TUNEL assay. Furthermore, the increase of intracellular ROS level in cultured neurons was suppressed by DCS (p < 0.05). Compared with cells subjected to OGD/R, the expression level of Bax protein decreased, and bcl-2 protein increased after DSC treatment (p < 0.05). Overall, the neuroprotective effects of DCS following cerebral ischemia may in part be due to decreased ROS production and inhibition of apoptosis.

Rutin: A Flavonoid as an Effective Sensitizer for Anticancer Therapy; Insights into Multifaceted Mechanisms and Applicability for Combination Therapy

Rutin is a unique antioxidant flavonoid that is mainly found in fruit, vegetables, cereals, and many other plant-based human diets. This review aims to highlight the in vitro anticancer properties of rutin including combination therapeutic strategies. Literature resources were gathered through PubMed, Scopus, Web of Science, and Google Scholar databases that cover the period of 1995–2021. Rutin is demonstrated to inhibit the proliferation of breast, colon, lung, and prostate cancers and other tumors. Furthermore, rutin alone or in combination with other therapeutic agents has been shown to regulate several signalling pathways involving the Ras/Raf and PI3K/Akt, MAPK, and TGF-β2/Smad2/3Akt/PTEN, etc., which are related to the processes of carcinogenesis and induction of apoptosis. The combination of rutin with other chemotherapy drugs may benefit on prevention of tumor cells by decreasing drug resistance and chemotherapy side effects. Moreover, rutin induces apoptosis synergistically with the therapeutic agent. More in vivo and clinical data are however needed to evaluate the true potential of rutin as an anticancer agent as an adjuvant. The present review highlights the effects of rutin which can be a promising candidate in combination with other antitumor drugs or alone for cancer treatment in vitro. Also, rutin can lead to decrease in drug resistance and chemotherapeutic side effects.

Anti-proliferative, pro-apoptotic and anti-invasive effect of the copper coordination compound Cas III-La through the induction of reactive oxygen species and regulation of Wnt/β-catenin pathway in glioma

Gliomas are the most aggressive neoplasms that affect the central nervous system, being glioblastoma multiforme (GBM) the most malignant. The resistance of GBM to therapies is attributed to its high rate of cell proliferation, angiogenesis, invasion, and resistance to apoptosis; thus, finding alternative therapeutic approaches is vital. In this work, the anti-proliferative, pro-apoptotic, and anti-invasive effect of the copper coordination compound Casiopeina III-La (Cas III-La) on human U373 MG cells was determined in vitro and in vivo. Our results indicate that Cas III-La exerts an anti-proliferative effect, promoting apoptotic cell death and inactivating the invasive process by generating reactive oxygen species (ROS), inactivating GSK3β, activating JNK and ERK, and promoting the nuclear accumulation of β-catenin. The inhibition of ROS generation by N-acetyl-l-cysteine not only recovered cell migration and viability, but also reduced β-catenin accumulation and JNK and ERK activation. Additionally, Cas III-La significantly reduced tumor volume, cell proliferation and mitotic indices, and increased the apoptotic index in mice xenotransplanted with U373 glioma cells. Thus, Cas III-La is a promising agent to treat GBM.

BZD9L1 sirtuin inhibitor: Identification of key molecular targets and their biological functions in HCT 116 colorectal cancer cells

BZD9L1 was previously described as a SIRT1/2 inhibitor with anti-cancer activities in colorectal cancer (CRC), either as a standalone chemotherapy or in combination with 5-fluorouracil. BZD9L1 was reported to induce apoptosis in CRC cells; however, the network of intracellular pathways and crosstalk between molecular players mediated by BZD9L1 is not fully understood. This study aimed to uncover the mechanisms involved in BZD9L1-mediated cytotoxicity based on previous and new findings for the prediction and identification of related pathways and key molecular players. BZD9L1-regulated candidate targets (RCTs) were identified using a range of molecular, cell-based and biochemical techniques on the HCT 116 cell line. BZD9L1 regulated major cancer pathways including Notch, p53, cell cycle, NFκB, Myc/MAX, and MAPK/ERK signalling pathways. BZD9L1 also induced reactive oxygen species (ROS), regulated apoptosis-related proteins, and altered cell polarity and adhesion profiles. In silico analyses revealed that most RCTs were interconnected, and were involved in the modulation of catalytic activity, metabolism and transcription regulation, response to cytokines, and apoptosis signalling pathways. These RCTs were implicated in p53-dependent apoptosis pathway. This study provides the first assessment of possible associations of molecular players underlying the cytotoxic activity of BZD9L1, and establishes the links between RCTs and apoptosis through the p53 pathway.

High-Fidelity and Simultaneous Sensing of Endogenous Mutant and Wild p53 Proteins for Precise Cancer Diagnosis and Drug Screening

The simultaneous sensing of endogenous wild and mutant proteins plays a critical role in disease diagnosis and drug screening, and this remains a major current challenge. Here, we present a new and highly specific target-triggered dual proximity ligation assay (dPLA) strategy for sensitive and simultaneous sensing of wild and mutant p53 proteins from cancer cells. Two proximity DNA probes bind the target protein to form the primer/circular DNA template complexes with two nicks in the presence of the hairpin and ssDNA connector sequences via the strand displacement reaction. Only when the two nicks are simultaneously ligated can the rolling circle amplification be triggered with high fidelity for yielding substantially enhanced fluorescence. By encoding the hairpin sequence, two distinct fluorescence signals can be generated for simultaneous detection of the wild and mutant p53 proteins. Importantly, our method significantly reduces the possibility of nonspecific ligation reactions by using two ligation nicks, which minimizes the background noise. With this dPLA method, the regulation transition of intracellular mutant p53 to wild p53 proteins upon anticancer drug treatment has also been demonstrated, highlighting its usefulness for potential early disease diagnosis and drug screening with high fidelity.

Tantalizing role of p53 molecular pathways and its coherent medications in neurodegenerative diseases

Neurodegenerative diseases are incongruous, commonly age-related disorders characterized by progressive neuronal loss, comprising the most prevalent being Alzheimer's disease, Parkinson's disease, and Huntington's disease. Perilous health states are anticipated following the neurodegeneration. Their etiology remains largely ambiguous, while various mechanisms are ascribed to their pathogenesis. A recommended conception is regarding the role of p53, as a transcription factor regulating numerous cellular pathways comprising apoptosis. Neuronal fates are a feasible occurrence that contributes to all neurodegenerative diseases. In this work, we review the research investigated the potential role of p53 in the pathogenesis of these diseases. We put special emphasis on intricate We not only describe aberrant changes in p53 level/activity observed in CNS regions affected by particular diseases but, most importantly, put special attention to the complicated reciprocal tuning connections prevailing between p53 and molecules considered in pathological hallmarks of these disorders. Natural and synthetic medications regulating p53 expression are regarded as well.

Flavonoid compound breviscapine suppresses human osteosarcoma Saos-2 progression property and induces apoptosis by regulating mitochondria-dependent pathway

This study was aimed to investigate the ability of a flavonoid compound breviscapine (BVP) to suppress growth and elicit apoptosis in human osteosarcoma (OS) Saos-2 cells. The cells were cultured in vitro and treated with three concentrations of BVP (80, 160, and 320 μg/ml). Moreover, C57 mice were injected with Saos-2 cells to establish a subcutaneous xenograft model, and they were subsequently treated with three doses of BVP via intraperitoneal injection. The viability of the cells was examined by the Cell Counting Kit-8 method. The apoptotic cells were assessed by flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labeling staining. The tumor volume and weight were monitored from day 3 through day 21 after the last injection. The expression of bax, bcl-2, and cytochrome c (cyt c) mRNA was detected by a real-time polymerase chain reaction. The protein levels of bax, bcl-2, cyt c, caspase 3, and caspase 9 were evaluated by Western blot. The expression and distribution of bcl-2 and bax in tissues were detected by immunohistochemistry. Compared with the control group, BVP treatment inhibited cell proliferation and induced apoptosis of Saos-2 cells in vitro. Consistently, treatment of mice bearing transplanted tumors with BVP suppressed the growth of OS tumors and promoted cell apoptosis; it also reduced tumor volume and weight. Mechanistically, BVP-induced apoptosis was mediated by the mitochondria-dependent pathway, as evidenced by the increased expression of bax and cyt c and the decreased expression of bcl-2, as well as activation of caspase 9 and caspase 3 in vitro and in vitro. Collectively, BVP inhibits growth and promotes apoptosis of OS by activating the mitochondrial apoptosis pathway.

Identification of Candidate Genes and Pathways in Nonsegmental Vitiligo Using Integrated Bioinformatics Methods

BACKGROUND

Nonsegmental vitiligo (NSV) is an acquired depigmentation disorder of unknown origin. Enormous interests focus on finding novel biomarkers and pathways responsible for NSV.

METHODS

The gene expression level was obtained by integrating microarray datasets (GSE65127 and GSE75819) from the Gene Expression Omnibus database using the sva R package. Differentially expressed genes (DEGs) between each group were identified by the limma R package. The interaction network was constructed using STRING, and significant modules coupled with hub genes were identified by cytoHubba and molecular complex detection. Pathway analyses were conducted using generally applicable gene set enrichment and further visualized in R environment.

RESULTS

A total of 102 DEGs between vitiligo lesional skin and healthy skin, 14 lesion-specific genes, and 29 predisposing genes were identified from the integrated dataset. Except for the anticipated decrease in melanogenesis, three major functional changes were identified, including oxidative phosphorylation, p53, and peroxisome proliferator-activated receptor (PPAR) signaling in lesional skin. PPARG, MUC1, S100A8, and S100A9 were identified as key hub genes involved in the pathogenesis of vitiligo. Besides, upregulation of the T cell receptor signaling pathway was considered to be associated with susceptibility of the skin in NSV patients.

CONCLUSION

Our study reveals several potential pathways and related genes involved in NSV using integrated bioinformatics methods. It might provide references for targeted strategies for NSV.

Infection of Mammals and Mosquitoes by Alphaviruses: Involvement of Cell Death

Alphaviruses, such as the chikungunya virus, are emerging and re-emerging viruses that pose a global public health threat. They are transmitted by blood-feeding arthropods, mainly mosquitoes, to humans and animals. Although alphaviruses cause debilitating diseases in mammalian hosts, it appears that they have no pathological effect on the mosquito vector. Alphavirus/host interactions are increasingly studied at cellular and molecular levels. While it seems clear that apoptosis plays a key role in some human pathologies, the role of cell death in determining the outcome of infections in mosquitoes remains to be fully understood. Here, we review the current knowledge on alphavirus-induced regulated cell death in hosts and vectors and the possible role they play in determining tolerance or resistance of mosquitoes.

Changes in Hippocampal Plasticity in Depression and Therapeutic Approaches Influencing These Changes

Depression is a common neurological disease that seriously affects human health. There are many hypotheses about the pathogenesis of depression, and the most widely recognized and applied is the monoamine hypothesis. However, no hypothesis can fully explain the pathogenesis of depression. At present, the brain-derived neurotrophic factor (BDNF) and neurogenesis hypotheses have highlighted the important role of plasticity in depression. The plasticity of neurons and glial cells plays a vital role in the transmission and integration of signals in the central nervous system. Plasticity is the adaptive change in the nervous system in response to changes in external signals. The hippocampus is an important anatomical area associated with depression. Studies have shown that some antidepressants can treat depression by changing the plasticity of the hippocampus. Furthermore, caloric restriction has also been shown to affect antidepressant and hippocampal plasticity changes. In this review, we summarize the latest research, focusing on changes in the plasticity of hippocampal neurons and glial cells in depression and the role of BDNF in the changes in hippocampal plasticity in depression, as well as caloric restriction and mitochondrial plasticity. This review may contribute to the development of antidepressant drugs and elucidating the mechanism of depression.

Diosmetin Induces Apoptosis by Downregulating AKT Phosphorylation via P53 Activation in Human Renal Carcinoma ACHN Cells

Background:

Diosmetin (DIOS) is the aglycone of the flavonoid glycoside, diosmin, derived naturally from the leaves of the legume, Olea europaea, and Acacia farnesiana. It has potent anticancer activity against multiple forms of cancers. However, the role of DIOS in renal carcinoma and its mechanism of action remain unclear.

Objective:

The purpose of this study is to investigate the effect of DIOS on cell viability and apoptosis in renal carcinoma cells and explore the possible mechanism of action.

Methods:

Cell viability, cytotoxicity, caspase activity, apoptosis, and expression of apoptotic related proteins were analyzed in renal carcinoma ACHN cells.

Results:

The results showed that DIOS inhibited the cell viability, and induced cytotoxicity and apoptosis in ACHN cells. Furthermore, DIOS increased expression of p53 mRNA and proteins, and downregulated phosphorylation of the phosphoinositide 3-kinase and protein B kinase (PI3K/AKT). In addition, it was observed that the anticancer effect of DIOS was significantly enhanced by the p53 activator, but inhibited by the p53 inhibitor.

Conclusion:

Our data suggested that DIOS induced apoptosis in renal carcinoma ACHN cells by reducing AKT phosphorylation through p53 upregulation.

Modulation of Apoptosis by Plant Polysaccharides for Exerting Anti-Cancer Effects: A Review

Cancer has become a significant public health problem with high disease burden and mortality. At present, radiotherapy and chemotherapy are the main means of treating cancer, but they have shown serious safety problems. The severity of this problem has caused further attention and research on effective and safe cancer treatment methods. Polysaccharides are natural products with anti-cancer activity that are widely present in a lot of plants, and many studies have found that inducing apoptosis of cancer cells is one of their important mechanisms. Therefore, this article reviews the various ways in which plant polysaccharides promote apoptosis of cancer cells. The major apoptotic pathways involved include the mitochondrial pathway, the death receptor pathway, and their upstream signal transduction such as MAPK pathway, PI3K/AKT pathway, and NF-κB pathway. Moreover, the paper has also been focused on the absorption and toxicity of plant polysaccharides with reference to extant literature, making the research more scientific and comprehensive. It is hoped that this review could provide some directions for the future development of plant polysaccharides as anticancer drugs in pharmacological experiments and clinical researches.

Induction of p53-Dependent Apoptosis by Prostaglandin A2

Prostaglandin (PG) A2, one of cyclopentenone PGs, is known to induce activation of apoptosis in various cancer cells. Although PGA2 has been reported to cause activation of apoptosis by altering the expression of apoptosis-related genes, the role of p53, one of the most critical pro-apoptotic genes, on PGA2-induced apoptosis has not been clarified yet. To address this issue, we compared the apoptosis in HCT116 p53 null cells (HCT116 p53-/-) to that in HCT116 cells containing the wild type p53 gene. Cell death induced by PGA2 was associated with phosphorylation of histone H2A variant H2AX (H2AX), activation of caspase-3 and cleavage of poly(ADP-ribose) polymerase 1 in HCT116 cells. Induction of apoptosis in PGA2-treated cells was almost completely prevented by pretreatment with a pan-caspase inhibitor, z-VAD-Fmk, or an inhibitor of protein synthesis, cycloheximide. While PGA2 induced apoptosis in HCT116 cells, phosphorylation of p53 and transcriptional induction of p53-target genes such as p21WAF1, PUMA, BAX, NOXA, and DR5 occurred. Besides, pretreatment of pifithrin-α (PFT-α), a chemical inhibitor of p53's transcriptional activity, interfered with the induction of apoptosis in PGA2-treated HCT116 cells. Pretreatment of NU7441, a small molecule inhibitor of DNA-activated protein kinase (DNA-PK) suppressed PGA2-induced phosphorylation of p53 and apoptosis as well. Moreover, among target genes of p53, knockdown of DR5 expression by RNA interference, suppressed PGA2-induced apoptosis. In the meanwhile, in HCT116 p53-/- cells, PGA2 induced apoptosis in delayed time points and with less potency. Delayed apoptosis by PGA2 in HCT116 p53-/- cells was also associated with phosphorylation of H2AX but was not inhibited by either PFT- or NU7441. Collectively, these results suggest the following. PGA2 may induce p53-dependent apoptosis in which DNA-PK activates p53, and DR5, a transcriptional target of p53, plays a pivotal role in HCT116 cells. In contrast to apoptosis in HCT116 cells, PGA2 may induce apoptosis in a fashion of less potency, which is independent of p53 and DNA-PK in HCT116 p53-/- cells.

Meclofenamic acid promotes cisplatin-induced acute kidney injury by inhibiting fat mass and obesity-associated protein-mediated m6A abrogation in RNA

The role of RNA methylation on the sixth N atom of adenylate (m⁶A) in acute kidney injury (AKI) is unknown. FTO (fat mass and obesity-associated protein) reverses the m⁶A modification in cisplatin-induced AKI. Here, we aimed to determine FTO's role in AKI. We induced AKI in c57BL/6 mice by intraperitoneal cisplatin injection and treated the animal with vehicle or an FTO inhibitor meclofenamic acid (MA) for 3 days. Moreover, as an in vitro model, human kidney proximal tubular cells (HK2 cells) were treated with cisplatin. We found that the cisplatin treatment reduces FTO expression and increases m⁶A levels in vivo and in vitro MA aggravated renal damage and increased apoptosis in cisplatin-treated kidneys, phenotypes that were correlated with reduced FTO expression and increased m⁶A levels. Moreover, MA promoted apoptosis in cisplatin-treated HK2 cells, which was correlated with the reduced FTO expression and increased m⁶A in HK2 cells. FTO protein overexpression reduced m⁶A levels and inhibited apoptosis in cisplatin-treated HK2 cells and also blocked the MA-induced increase in m⁶A levels and apoptosis rates. In agreement, overexpression of the m⁶A-generating methyltransferase-like 3 and 14 (METTL3 and METTL14) or siRNA-mediated FTO knockdown promoted apoptosis and enhanced m⁶A levels in cisplatin-treated HK2 cells. MA increased p53 mRNA and protein levels in AKI both in vitro and in vivo, and FTO overexpression reduced p53 expression and reversed the MA-induced p53 increase in AKI. In conclusion, reduced renal FTO expression in cisplatin-induced AKI increases RNA m⁶A levels and aggravates renal damages.

Antiparasitic effect of (-)-α-bisabolol against Trypanosoma cruzi Y strain forms

Chagas disease is caused by Trypanosoma cruzi and affects about 7 million people worldwide. Benznidazole and nifurtimox have low efficacy and high toxicity. The present study was designed to identify the trypanocidal effect of (-)-α-Bisabolol (BIS) and investigate its mechanism. Epimastigotes and trypomastigotes were cultured with BIS and the viable cells were counted. BIS antiamastigote effect was evaluated using infected LLC-MK2 cells. MTT assay was performed to evaluate BIS cytotoxicity. Growth recovery was assessed to evaluate BIS effect after short times of exposure. BIS mechanism was investigated through flow cytometry, with 7-AAD and Annexin V-PE. DCFH-DA, rhodamine 123 (Rho123) and acridine orange (AO). Finally, enzymatic and computational assays were performed to identify BIS interaction with T. cruzi GAPDH (tcGAPDH). BIS showed an inhibitory effect on epimastigotes after all tested periods, as well on trypomastigotes. It caused cytotoxicity on LLC-MK2 cells at higher concentrations, with selectivity index (SeI) = 26.5. After treatment, infected cells showed a decrease in infected cells, the number of amastigotes per infected cell and the survival index (SuI). Growth recovery demonstrated that BIS effect causes rapid death of T. cruzi. Flow cytometry showed that BIS biological effect is associated with apoptosis induction, increase in cytoplasmic ROS and mitochondrial transmembrane potential, while reservosome swelling was observed at a late stage. Also, BIS action mechanism may be associated to tcGAPDH inhibition. Altogether, the results demonstrate that BIS causes cell death in Trypanosoma cruzi Y strain forms, with the involvement of apoptosis and oxidative stress and enzymatic inhibition.