p53 promotes VEGF expression and angiogenesis in the absence of an intact p21-Rb pathway

Intramyocardial Sprouting Tip Cells Specify Coronary Arterialization

BACKGROUND

The elaborate patterning of coronary arteries critically supports the high metabolic activity of the beating heart. How coronary endothelial cells coordinate hierarchical vascular remodeling and achieve arteriovenous specification remains largely unknown. Understanding the molecular and cellular cues that pattern coronary arteries is crucial to develop innovative therapeutic strategies that restore functional perfusion within the ischemic heart.

METHODS

Single-cell transcriptomics and histological validation were used to delineate heterogeneous transcriptional states of the developing and mature coronary endothelium with a focus on sprouting endothelium and arterial cell specification. Genetic lineage tracing and high-resolution 3-dimensional imaging were used to characterize the origin and mechanisms of coronary angiogenic sprouting, as well as to fate-map selective endothelial lineages. Integration of single-cell transcriptomic data from ischemic adult mouse hearts and human embryonic data served to assess the conservation of transcriptional states across development, disease, and species.

RESULTS

We discover that coronary arteries originate from cells that have previously transitioned through a specific tip cell phenotype. We identify nonoverlapping intramyocardial and subepicardial tip cell populations with differential gene expression profiles and regulatory pathways. Esm1-lineage tracing confirmed that intramyocardial tip cells selectively contribute to coronary arteries and endocardial tunnels, but not veins. Notably, prearterial cells are detected from development stages to adulthood, increasingly in response to ischemic injury, and in human embryos, suggesting that tip cell-to-artery specification is a conserved mechanism.

CONCLUSIONS

A tip cell-to-artery specification mechanism drives arterialization of the intramyocardial plexus and endocardial tunnels throughout life and is reactivated upon ischemic injury. Differential sprouting programs govern the formation and specification of the venous and arterial coronary plexus.

The Role of Microvascular Variations in the Process of Intervertebral Disk Degeneration and Its Regulatory Mechanisms: A Literature Review

Microvascular changes are considered key factors in the process of intervertebral disk degeneration (IDD). Microvascular invasion and growth into the nucleus pulposus (NP) and cartilaginous endplates are unfavorable factors that trigger IDD. In contrast, the rich distribution of microvessels in the bony endplates and outer layers of the annulus fibrosus is an important safeguard for the nutrient supply and metabolism of the intervertebral disk (IVD). In particular, the adequate supply of microvessels in the bony endplates is the main source of the nutritional supply for the entire IVD. Microvessels can affect the progression of IDD through a variety of pathways. Many studies have explored the effects of microvessel alterations in the NP, annulus fibrosus, cartilaginous endplates, and bony endplates on the local microenvironment through inflammation, apoptosis, and senescence. Studies also elucidated the important roles of microvessel alterations in the process of IDD, as well as conducted in-depth explorations of cytokines and biologics that can inhibit or promote the ingrowth of microvessels. Therefore, the present manuscript reviews the published literature on the effects of microvascular changes on IVD to summarize the roles of microvessels in IVD and elaborate on the mechanisms of action that promote or inhibit de novo microvessel formation in IVD.

VEGF as a Key Actor in Recurrent Respiratory Papillomatosis: A Narrative Review

Recurrent respiratory papillomatosis (RRP) is a benign disease of the upper aerodigestive tract caused by human papillomavirus (HPV) types 6 and 11. The clinical course is unpredictable and some patients, especially younger children, experience a high rate of recurrence with a significant impact on their quality of life. The molecular mechanisms of HPV infection in keratinocytes have been extensively studied throughout the years, with particular regard to its role in causing malignant tumors, like cervical cancer and head and neck carcinomas. A minor but not negligible amount of the literature has investigated the molecular landscape of RRP patients, and some papers have studied the role of angiogenesis (the growth of blood vessels from pre-existing vasculature) in this disease. A central role in this process is played by vascular endothelial growth factor (VEGF), which activates different signaling cascades on multiple levels. The increased knowledge has led to the introduction of the VEGF inhibitor bevacizumab in recent years as an adjuvant treatment in some patients, with good results. This review summarizes the current evidence about the role of VEGF in the pathophysiology of RRP, the molecular pathways activated by binding with its receptors, and the current and future roles of anti-angiogenic treatment.

Targeting ONECUT2 inhibits tumor angiogenesis via down-regulating ZKSCAN3/VEGFA

OC-2 plays a vital role in tumor growth, metastasis and angiogenesis, but molecular mechanism how OC-2 regulates angiogenic factors is unclear. We found that OC-2 was highly expressed in HepG2, COLO, MCF-7, SKOV3 cells and rectum carcinoma tissues, and angiogenic factors levels were positively related to OC-2. Then OC-2 KD inhibited the tumor growth, metastasis and angiogenesis process in vitro and vivo. ChIP-Seq showed that 228 target genes of OC-2 were identified and they were associated with tumor growth, metastasis, angiogenesis and signal transduction; OC-2 bound to ZKSCAN3 at promoter region. Luciferase assays showed that ZKSCAN3 was identified as target gene of OC-2 and VEGFA was identified as target gene of ZKSCAN3; OC-2 promoted VEGFA expression via activating ZKSCAN3 transcriptional program. Importantly, OC-2 KD down-regulated VEGFA secretion to suppress tumor angiogenesis of HUVECs. Besides VEGFA, OC-2 was positively correlated with other angiogenic factors HIF-1α, FGF2, EGFL6 and HGF. Meanwhile, ERK1/2 and Smad1 signaling pathways might be related to function of OC-2 driving tumor aggressiveness. We revealed that OC-2 might regulate tumor growth, metastasis, angiogenesis via ERK1/2, Smad1 signaling pathways and regulate VEGFA expression for tumor angiogenesis via activating ZKSCAN3 transcriptional program, indicating that OC-2 was a convincing target to develop novel anti-tumor drugs based on angiogenesis.

USP7 inhibitors suppress tumour neoangiogenesis and promote synergy with immune checkpoint inhibitors by downregulating fibroblast VEGF

BACKGROUND

Understanding how to modulate the microenvironment of tumors that are resistant to immune checkpoint inhibitors represents a major challenge in oncology.Here we investigate the ability of USP7 inhibitors to reprogram the tumor microenvironment (TME) by inhibiting secretion of vascular endothelial growth factor (VEGF) from fibroblasts.

METHODS

To understand the role played by USP7 in the TME, we systematically evaluated the effects of potent, selective USP7 inhibitors on co-cultures comprising components of the TME, using human primary cells. We also evaluated the effects of USP7 inhibition on tumor growth inhibition in syngeneic models when dosed in combination with immune checkpoint inhibitors (ICIs).

RESULTS

Abrogation of VEGF secretion from fibroblasts in response to USP7 inhibition resulted in inhibition of tumor neoangiogenesis and increased tumor recruitment of CD8-positive T-lymphocytes, leading to significantly improved sensitivity to immune checkpoint inhibitors. In syngeneic models, treatment with USP7 inhibitors led to striking tumor responses resulting in significantly improved survival.

CONCLUSIONS

USP7-mediated reprograming of the TME is not linked to its previously characterized role in modulating MDM2 but does require p53 and UHRF1 in addition to the well-characterized VEGF transcription factor, HIF-1α. This represents a function of USP7 that is unique to fibroblasts, and which is not observed in cancer cells or other components of the TME. Given the potential for USP7 inhibitors to transform "immune desert" tumors into "immune responsive" tumors, this paves the way for a novel therapeutic strategy combining USP7 inhibitors with immune checkpoint inhibitors (ICIs).

p53 stabilisation potentiates [177Lu]Lu-DOTATATE treatment in neuroblastoma xenografts

PURPOSE

Molecular radiotherapy is a treatment modality that is highly suitable for targeting micrometastases and [177Lu]Lu-DOTATATE is currently being explored as a potential novel treatment option for high-risk neuroblastoma. p53 is a key player in the proapoptotic signalling in response to radiation-induced DNA damage and is therefore a potential target for radiosensitisation.

METHODS

This study investigated the use of the p53 stabilising peptide VIP116 and [177Lu]Lu-DOTATATE, either alone or in combination, for treatment of neuroblastoma tumour xenografts in mice. Initially, the uptake of [177Lu]Lu-DOTATATE in the tumours was confirmed, and the efficacy of VIP116 as a monotherapy was evaluated. Subsequently, mice with neuroblastoma tumour xenografts were treated with placebo, VIP116, [177Lu]Lu-DOTATATE or a combination of both agents.

RESULTS

The results demonstrated that monotherapy with either VIP116 or [177Lu]Lu-DOTATATE significantly prolonged median survival compared to the placebo group (90 and 96.5 days vs. 50.5 days, respectively). Notably, the combination treatment further improved median survival to over 120 days. Furthermore, the combination group exhibited the highest percentage of complete remission, corresponding to a twofold increase compared to the placebo group. Importantly, none of the treatments induced significant nephrotoxicity. Additionally, the therapies affected various molecular targets involved in critical processes such as apoptosis, hypoxia and angiogenesis.

CONCLUSION

In conclusion, the combination of VIP116 and [177Lu]Lu-DOTATATE presents a promising novel treatment approach for neuroblastoma. These findings hold potential to advance research efforts towards a potential cure for this vulnerable patient population.

CDKN1A/p21 in Breast Cancer: Part of the Problem, or Part of the Solution?

Cyclin-dependent kinase inhibitor 1A (Cip1/Waf1/CDKN1A/p21) is a well-established protein, primarily recognised for its pivotal role in the cell cycle, where it induces cell cycle arrest by inhibiting the activity of cyclin-dependent kinases (CDKs). Over the years, extensive research has shed light on various additional mechanisms involving CDKN1A/p21, implicating it in processes such as apoptosis, DNA damage response (DDR), and the regulation of stem cell fate. Interestingly, p21 can function either as an oncogene or as a tumour suppressor in these contexts. Complicating matters further, the expression of CDKN1A/p21 is elevated in certain tumour types while downregulated in others. In this comprehensive review, we provide an overview of the multifaceted functions of CDKN1A/p21, present clinical data pertaining to cancer patients, and delve into potential strategies for targeting CDKN1A/p21 as a therapeutic approach to cancer. Manipulating CDKN1A/p21 shows great promise for therapy given its involvement in multiple cancer hallmarks, such as sustained cell proliferation, the renewal of cancer stem cells (CSCs), epithelial-mesenchymal transition (EMT), cell migration, and resistance to chemotherapy. Given the dual role of CDKN1A/p21 in these processes, a more in-depth understanding of its specific mechanisms of action and its regulatory network is imperative to establishing successful therapeutic interventions.

Reduced FOXF1 links unrepaired DNA damage to pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease in which pulmonary arterial (PA) endothelial cell (EC) dysfunction is associated with unrepaired DNA damage. BMPR2 is the most common genetic cause of PAH. We report that human PAEC with reduced BMPR2 have persistent DNA damage in room air after hypoxia (reoxygenation), as do mice with EC-specific deletion of Bmpr2 (EC-Bmpr2-/-) and persistent pulmonary hypertension. Similar findings are observed in PAEC with loss of the DNA damage sensor ATM, and in mice with Atm deleted in EC (EC-Atm-/-). Gene expression analysis of EC-Atm-/- and EC-Bmpr2-/- lung EC reveals reduced Foxf1, a transcription factor with selectivity for lung EC. Reducing FOXF1 in control PAEC induces DNA damage and impaired angiogenesis whereas transfection of FOXF1 in PAH PAEC repairs DNA damage and restores angiogenesis. Lung EC targeted delivery of Foxf1 to reoxygenated EC-Bmpr2-/- mice repairs DNA damage, induces angiogenesis and reverses pulmonary hypertension.

Transcriptome and proteome analysis reveals the anti-cancer properties of Hypnea musciformis marine macroalga extract in liver and intestinal cancer cells

BACKGROUND

Marine seaweeds are considered as a rich source of health-promoting compounds by the food and pharmaceutical industry. Hypnea musciformis is a marine red macroalga (seaweed) that is widely distributed throughout the world, including the Mediterranean Sea. It is known to contain various bioactive compounds, including sulfated polysaccharides, flavonoids, and phlorotannins. Recent studies have investigated the potential anticancer effects of extracts from H. musciformis demonstrating their cytotoxic effects on various cancer cell lines. The anticancer effects of these extracts are thought to be due to the presence of bioactive compounds, particularly sulfated polysaccharides, which have been shown to have anticancer and immunomodulatory effects. However, further studies are needed to fully understand the molecular mechanisms that underlie their anticancer effects and to determine their potential as therapeutic agents for cancer treatment.

METHODS

H. musciformis was collected from the Aegean Sea (Greece) and used for extract preparation. Transcriptome and proteome analysis was performed in liver and colon cancer human cell lines following treatment with H. musciformis seaweed extracts to characterize its anticancer effect in detail at the molecular level and to link transcriptome and proteome responses to the observed phenotypes in cancer cells.

RESULTS

We have identified that treatment with the seaweed extract triggers a p53-mediated response at the transcriptional and protein level in liver cancer cells, in contrast to colon cancer cells in which the effects are more associated with metabolic changes. Furthermore, we show that in treated HepG2 liver cancer cells, p53 interacts with the chromatin of several target genes and facilitates their upregulation possibly through the recruitment of the p300 co-activator.

CONCLUSIONS

Overall, the available evidence suggests that extracts from H. musciformis have the potential to serve as a source of anticancer agents in liver cancer cells mainly through activation of a p53-mediated anti-tumor response that is linked to inhibition of cellular proliferation and induction of cell death.

Potential enhancement of post-stroke angiogenic response by targeting the oligomeric aggregation of p53 protein

Tumor suppressor gene p53 and its aggregate have been found to be involved in many angiogenesis-related pathways. We explored the possible p53 aggregation formation mechanisms commonly occur after ischemic stroke, such as hypoxia and the presence of reactive oxygen species (ROS). The angiogenic pathways involving p53 mainly occur in nucleus or cytoplasm, with one exception that occurs in mitochondria. Considering the high mitochondrial density in brain and endothelial cells, we proposed that the cyclophilin D (CypD)-dependent vascular endothelial cell (VECs) necrosis pathway occurring in the mitochondria is one of the major factors that affects angiogenesis. Hence, targeting p53 aggregation, a key intermediate in the pathway, could be an alternative therapeutic target for post-stroke management.

Reduction of Tumor Growth with RNA-Targeting Treatment of the NAB2-STAT6 Fusion Transcript in Solitary Fibrous Tumor Models

Solitary fibrous tumor (SFT) is a rare soft-tissue sarcoma. This nonhereditary cancer is the result of an environmental intrachromosomal gene fusion between NAB2 and STAT6 on chromosome 12, which fuses the activation domain of STAT6 with the repression domain of NAB2. Currently there is not an approved chemotherapy regimen for SFTs. The best response on available pharmaceuticals is a partial response or stable disease for several months. The purpose of this study is to investigate the potential of RNA-based therapies for the treatment of SFTs. Specifically, in vitro SFT cell models were engineered to harbor the characteristic NAB2-STAT6 fusion using the CRISPR/SpCas9 system. Cell migration as well as multiple cancer-related signaling pathways were increased in the engineered cells as compared to the fusion-absent parent cells. The SFT cell models were then used for evaluating the targeting efficacies of NAB2-STAT6 fusion-specific antisense oligonucleotides (ASOs) and CRISPR/CasRx systems. Our results showed that fusion specific ASO treatments caused a 58% reduction in expression of fusion transcripts and a 22% reduction in cell proliferation after 72 h in vitro. Similarly, the AAV2-mediated CRISPR/CasRx system led to a 59% reduction in fusion transcript expressions in vitro, and a 55% reduction in xenograft growth after 29 days ex vivo.

Potential Benefits of Dietary Plant Compounds on Normal and Tumor Brain Cells in Humans: In Silico and In Vitro Approaches

Neuroblastoma can be accessed with compounds of larger sizes and wider polarities, which do not usually cross the blood-brain barrier. Clinical data indicate cases of spontaneous regression of neuroblastoma, suggesting a reversible point in the course of cell brain tumorigenesis. Dual specificity tyrosine-phosphorylation-regulated kinase2 (DYRK2) is a major molecular target in tumorigenesis, while curcumin was revealed to be a strong inhibitor of DYRK2 (PBD ID: 5ZTN). Methods: in silico studies by CLC Drug Discovery Workbench (CLC) and Molegro Virtual Docker (MVD) Software on 20 vegetal compounds from the human diet tested on 5ZTN against the native ligand curcumin, in comparison with anemonin. In vitro studies were conducted on two ethanolic extracts from Anemone nemorosa tested on normal and tumor human brain cell lines NHA and U87, compared with four phenolic acids (caffeic, ferulic, gentisic, and para-aminobenzoic/PABA). Conclusions: in silico studies revealed five dietary compounds (verbascoside, lariciresinol, pinoresinol, medioresinol, matairesinol) acting as stronger inhibitors of 5ZTN compared to the native ligand curcumin. In vitro studies indicated that caffeic acid has certain anti-proliferative effects on U87 and small benefits on NHA viability. A. nemorosa extracts indicated potential benefits on NHA viability, and likely dangerous effects on U87.

In silico prediction and biological assessment of novel angiogenesis modulators from traditional Chinese medicine

Uncontrolled angiogenesis is a common denominator underlying many deadly and debilitating diseases such as myocardial infarction, chronic wounds, cancer, and age-related macular degeneration. As the current range of FDA-approved angiogenesis-based medicines are far from meeting clinical demands, the vast reserve of natural products from traditional Chinese medicine (TCM) offers an alternative source for developing pro-angiogenic or anti-angiogenic modulators. Here, we investigated 100 traditional Chinese medicine-derived individual metabolites which had reported gene expression in MCF7 cell lines in the Gene Expression Omnibus (GSE85871). We extracted literature angiogenic activities for 51 individual metabolites, and subsequently analysed their predicted targets and differentially expressed genes to understand their mechanisms of action. The angiogenesis phenotype was used to generate decision trees for rationalising the poly-pharmacology of known angiogenesis modulators such as ferulic acid and curculigoside and validated by an in vitro endothelial tube formation assay and a zebrafish model of angiogenesis. Moreover, using an in silico model we prospectively examined the angiogenesis-modulating activities of the remaining 49 individual metabolites. In vitro, tetrahydropalmatine and 1 beta-hydroxyalantolactone stimulated, while cinobufotalin and isoalantolactone inhibited endothelial tube formation. In vivo, ginsenosides Rb3 and Rc, 1 beta-hydroxyalantolactone and surprisingly cinobufotalin, restored angiogenesis against PTK787-induced impairment in zebrafish. In the absence of PTK787, deoxycholic acid and ursodeoxycholic acid did not affect angiogenesis. Despite some limitations, these results suggest further refinements of in silico prediction combined with biological assessment will be a valuable platform for accelerating the research and development of natural products from traditional Chinese medicine and understanding their mechanisms of action, and also for other traditional medicines for the prevention and treatment of angiogenic diseases.

The role of p53 in the alternation of vascular functions

Ageing is a risk factor for many degenerative diseases. Cardiovascular diseases (CVDs) are usually big burdens for elderly, caregivers and the health system. During the aging process, normal functions of vascular cells and tissue progressively lost and eventually develop vascular diseases. Endothelial dysfunction, reduced bioavailability of endothelium-derived nitric oxide are usual phenomena observed in patients with cardiovascular diseases. Myriad of studies have been done to investigate to delay the vascular dysfunction or improve the vascular function to prolong the aging process. Tumor suppressor gene p53, also a transcription factor, act as a gatekeeper to regulate a number of genes to maintain normal cell function including but not limited to cell proliferation, cell apoptosis. p53 also crosstalk with other key transcription factors like hypoxia-inducible factor 1 alpha that contribute to the progression of cardiovascular diseases. Therefore, in recent three decades, p53 has drawn scientists’ attention on its effects in vascular function. Though the role of tumor suppressor gene p53 is still not clear in vascular function, it is found to play regulatory roles and may involve in vascular remodeling, atherosclerosis or pulmonary hypertension. p53 may have a divergent role in endothelial and vascular muscle cells in those conditions. In this review, we describe the different effects of p53 in cardiovascular physiology. Further studies on the effects of endothelial cell-specific p53 deficiency on atherosclerotic plaque formation in common animal models are required before the therapeutic potential can be realized.

Alterations in p53 Influence hTERT, VEGF and MMPs Expression in Oral Cancer Patients

BACKGROUND

Mutant p53 is the crucial molecule in the etiopathogenesis of oral cancer. Therefore, we aimed to evaluate the impact of alterations of the p53 gene and its negative feedback regulator, MDM2, on the expression of hTERT, VEGF, and MMPs; the critical genes involved in oral cancer progression.

MATERIAL AND METHODS

p53 and MDM2 genotyping were done by PCR-RFLP. p53 mutation analysis was performed using PCR-SSCP and sequencing. hTERT, VEGFA isoforms, MMP2, and MMP9 mRNA levels were analyzed by semi-quantitative Reverse Transcriptase PCR.

RESULTS

Arg allele at p53 exon 4 was significantly associated with overexpression of hTERT, MMP2, and MMP9 individually. Expression of hTERT, VEGF A isoforms, MMP2 and MMP9 were significantly altered in the presence of p53 and MDM2 polymorphisms and p53 mutations in a specific combination. Mutant p53, Arg allele at p53 exon 4 locus, and G/G/or T/T genotype at MDM2revealed increased expression of hTERT, VEGF A isoforms, and MMP2/9.

CONCLUSION

This study provides evidence that apart from mutant p53, naturally occurring sequence variants in p53codon 72 (Arg72Pro) (rs1042522) and MDM2 (rs2279744) significantly alter the expression of hTERT, VEGF-A isoforms, and MMP2/9 in a specific combination. The differential interaction of codon 72 variants with MDM2, hTERT, VEGF-A isoforms and MMP2/9 play a role in the aggressiveness of oral cancer. The results have important implications for oral cancer progression and should be explored for innovative treatment options.

VEGFR endocytosis: Implications for angiogenesis

The binding of vascular endothelial growth factor (VEGF) superfamily to VEGF receptor tyrosine kinases (VEGFRs) and co-receptors regulates vasculogenesis, angiogenesis and lymphangiogenesis. A recurring theme is that dysfunction in VEGF signaling promotes pathological angiogenesis, an important feature of cancer and pro-inflammatory disease states. Endocytosis of basal (resting) or activated VEGFRs facilitates signal attenuation and endothelial quiescence. However, increasing evidence suggest that activated VEGFRs can continue to signal from intracellular compartments such as endosomes. In this chapter, we focus on the evolving link between VEGFR endocytosis, signaling and turnover and the implications for angiogenesis. There is much interest in how such understanding of VEGFR dynamics can be harnessed therapeutically for a wide range of human disease states.

Deepening the knowledge of rare diseases dependent on angiogenesis through semantic similarity clustering and network analysis

BACKGROUND

Angiogenesis is regulated by multiple genes whose variants can lead to different disorders. Among them, rare diseases are a heterogeneous group of pathologies, most of them genetic, whose information may be of interest to determine the still unknown genetic and molecular causes of other diseases. In this work, we use the information on rare diseases dependent on angiogenesis to investigate the genes that are associated with this biological process and to determine if there are interactions between the genes involved in its deregulation.

RESULTS

We propose a systemic approach supported by the use of pathological phenotypes to group diseases by semantic similarity. We grouped 158 angiogenesis-related rare diseases in 18 clusters based on their phenotypes. Of them, 16 clusters had traceable gene connections in a high-quality interaction network. These disease clusters are associated with 130 different genes. We searched for genes associated with angiogenesis througth ClinVar pathogenic variants. Of the seven retrieved genes, our system confirms six of them. Furthermore, it allowed us to identify common affected functions among these disease clusters.

AVAILABILITY

https://github.com/ElenaRojano/angio_cluster.

CONTACT

seoanezonjic@uma.es and elenarojano@uma.es.

Impact of Smoking Status in Combination Treatment with EGFR Tyrosine Kinase Inhibitors and Anti-Angiogenic Agents in Advanced Non-Small Cell Lung Cancer Harboring Susceptible EGFR Mutations: Systematic Review and Meta-Analysis

Patients with advanced non-small cell lung cancer (NSCLC) who harbor susceptible epidermal growth factor receptor (EGFR) mutations and are treated with EGFR tyrosine kinase inhibitors (TKIs) show longer progression-free survival (PFS) than those treated with chemotherapy. However, developed EGFR-TKI resistance limits PFS improvements. Currently, combination treatment with EGFR-TKIs and anti-angiogenic agents is considered a beneficial regimen for advanced-stage NSCLC harboring susceptible EGFR mutations. However, several trials reported osimertinib plus bevacizumab failed to show superior efficacy over osimertinib alone. However, subgroup analysis showed significantly longer PFS among patients with a history of smoking over those who never smoked. We performed a comprehensive systematic review and meta-analysis to evaluate the smoking status impact. At the end of the process, a total of 2068 patients from 11 randomized controlled trials (RCTs) were included in our meta-analysis. Overall, combination EGFR-TKI plus anti-angiogenic agent treatment showed significantly better PFS among patients with a smoking history (Hazard Ratio (HR) = 0.59, 95% confidence interval (CI) = 0.48-0.73). Erlotinib-based combination therapy showed positive PFS benefits regardless of smoking status (HR = 0.54, 95%CI = 0.41-0.71 for ever smoker, HR = 0.69, 95%CI = 0.54-0.87 for never smoker). Combination therapy prolonged PFS significantly regardless of ethnicity (HR: 0.64, 95% CI: 0.44-0.93 for Asian RCTs, HR: 0.55, 95% CI: 0.41-0.74 for global and non-Asian RCTs). PROSPERO registration number is CRD42022304198).

Virtual ChIP-seq: predicting transcription factor binding by learning from the transcriptome

Existing methods for computational prediction of transcription factor (TF) binding sites evaluate genomic regions with similarity to known TF sequence preferences. Most TF binding sites, however, do not resemble known TF sequence motifs, and many TFs are not sequence-specific. We developed Virtual ChIP-seq, which predicts binding of individual TFs in new cell types, integrating learned associations with gene expression and binding, TF binding sites from other cell types, and chromatin accessibility data in the new cell type. This approach outperforms methods that predict TF binding solely based on sequence preference, predicting binding for 36 TFs (MCC>0.3).

Context dependent role of p53 during the interaction of hepatocellular carcinoma and endothelial cells

BACKGROUND

During the progression of hepatocellular carcinoma (HCC), several angiogenic factors are overexpressed in the hepatic microenvironment, which play a critical role in governing the phenotype of the endothelial cells. Mutation in the p53 gene (TP53) is a common event in HCC that may dysregulate the angiogenic signals. However, their functional messages remain largely unexplored at the onset of metastasis.

METHODS

Role of p53 was studied by siRNA mediated silencing of p53 in HepG2 cells (WTp53), collecting and analyzing their conditioned medium, followed by indirect co-culture with endothelial cells (HUVECs). Gene and protein expression in HCC cells and endothelial cells was studied by RT-qPCR and western blotting respectively. β-catenin protein expression and localization were analyzed by immunocytochemistry.

RESULTS

We have studied a cell-to-cell interaction model to investigate the crosstalk of endothelial and hepatoma cells by either knocking down p53 or by using p53 null low metastatic HCC cell line. In the absence of p53, the HCC cells influence the migration and vascular network formation of endothelial cells through paracrine signaling of VEGF. Secretory VEGF activated the VEGF receptor-2 along with the survival signaling in endothelial cells. However, the β-catenin signal is upregulated in endothelial cells only during interaction with metastatic set up irrespective of absence and presence of p53, indicating context-dependent participation of p53 during communication between hepatoma cells and endothelial cells.

CONCLUSION

This study highlights that the role of p53 on cellular responses during interaction of hepatocellular carcinoma and endothelial cells is distinct to cell types and context.

Platycodon D-induced A549 cell apoptosis through RRM1-regulated p53/VEGF/MMP2 pathway

BACKGROUND

Lung cancer is one of the leading causes of cancer-related deaths worldwide. Platycodin D (PD), a major pharmacological constituent from the Chinese medicinal herb named Platycodonis Radix, has shown potent anti-tumor activity. Also, it is also reported that PD could inhibit cellular growth in the non-small-cell lung carcinoma (NSCLC) A549 cell line. However, the underlying mechanism is not fully clarified.

METHODS

Cell proliferation was measured by MTT assay. Annexin V and propidium iodide (PI) assay were employed to study the apoptosis effects of PD on A549 cells. Western blot analysis was used to evaluate protein expression. Also, we used a siRNA against p53, as well as a plasmid-based RRM1 over-expression to investigate their functions.

RESULTS

It demonstrated PD inhibited A549 cell proliferation in a dose- and time-dependent manner. Further investigations showed that PD induced cell apoptosis, which was supported by dose-dependent and time-dependent caspase-3 activation and p53/VEGF/MMP2 pathway regulation. Also, PD demonstrated the inhibition effect of ribonucleotide reductase M1 (RRM1), whose role in various tumors is contradictory. Remarkably, in this work, RRM1 overexpression in A549 cells could have a negative impact on the regulation of the p53/VEGF/MMP2 pathway induced by PD treatment. Note as well that RRM1 overexpression also attenuated cell apoptosis and inhibition of cell proliferation of A549 treated with PD.

CONCLUSION

The results suggested that PD could inhibit A549 cell proliferation and induce cell apoptosis by regulating p53/VEGF/MMP2 pathway, in which RRM1 plays an important role directly.

Real-World Data: Fruquintinib in Treating Metastatic Colorectal Cancer

Fruquintinib, also called HMPL-013, was first discovered by Hutchison Whampoa Pharmaceuticals Co. Ltd., Shanghai, China, and it is an oral vascular endothelial growth factor receptor (VEGFR) inhibitor. In clinical trials, fruquintinib has demonstrated a survival benefit in metastatic colorectal cancer (mCRC) patients. The purpose of this study was to retrospectively evaluate the efficacy and toxicity of fruquintinib in real-world patients. We collected data from patients with mCRC treated with oral fruquintinib from 2018 to 2020 in six different institutions. Patients with mCRC initially received 5 mg of oral fruquintinib daily for 3 weeks. Progression-free survival (PFS) was evaluated using the Kaplan–Meier method. The efficacy and safety of fruquintinib were also assessed. Seventy-five patients were involved in our study, and 29.3% of patients achieved stable disease (SD). Median PFS was 5.4 months (95% CI: 4.841–5.959). The treatment-emergent adverse events (TEAEs) with fruquintinib were acceptable with grade 3 TEAEs of 6%. The grade 3 TEAEs were hand–foot skin reaction (HFSR), fatigue, and stomatitis. The ECOG performance status was associated with PFS. In this real-world study, the clinical activity of fruquintinib was consistent with what has been reported in previous clinical trials. The level of safety was acceptable, and the side effects were manageable.

Ginsenoside Rg3 attenuates skin disorders via down-regulation of MDM2/HIF1α signaling pathway

Background

Thymic stromal lymphopoietin (TSLP) acts as a master switch for inflammatory responses. Ginsenoside Rg3 (Rg3) which is an active ingredient of Panax ginseng Meyer (Araliaceae) is known to possess various therapeutic effects. However, a modulatory effect of Rg3 on TSLP expression in the inflammatory responses remains poorly understood.

Methods

We investigated antiinflammatory effects of Rg3 on an in vitro model using HMC-1 cells stimulated by PMA plus calcium ionophore (PMACI), as well as an in vivo model using PMA-induced mouse ear edema. TSLP and vascular endothelial growth factor (VEGF) levels were detected using enzyme-linked immunosorbent assay or real-time PCR analysis. Murine double minute 2 (MDM2) and hypoxia-inducible factor 1α (HIF1α) expression levels were detected using Western blot analysis.

Results

Rg3 treatment restrained the production and mRNA expression levels of TSLP and VEGF in activated HMC-1 cells. Rg3 down-regulated the MDM2 expression level increased by PMACI stimulation. The HIF1α expression level was also reduced by Rg3 in activated HMC-1 cells. In addition, Rg3-administered mice showed the decreased redness and ear thickness in PMA-irritated ear edema. Rg3 inhibited the TSLP and VEGF levels in the serum and ear tissue homogenate. Moreover, the MDM2 and HIF1α expression levels in the ear tissue homogenate were suppressed by Rg3.

Conclusion

Taken together, the current study identifies new mechanistic evidence about MDM2/HIF1α pathway in the antiinflammatory effect of Rg3, providing a new effective therapeutic strategy for the treatment of skin inflammatory diseases.

Extracellular vesicles derived from hypoxia-preconditioned olfactory mucosa mesenchymal stem cells enhance angiogenesis via miR-612

Mesenchymal stem cells (MSCs) play important roles in tissue repair and regeneration, such as the induction of angiogenesis, particularly under hypoxic conditions. However, the molecular mechanisms underlying hypoxic MSC activation remain largely unknown. MSC-derived extracellular vesicles (EVs) are vital mediators of cell-to-cell communication and can be directly utilized as therapeutic agents for tissue repair and regeneration. Here, we explored the effects of EVs from human hypoxic olfactory mucosa MSCs (OM-MSCs) on angiogenesis and its underlying mechanism. EVs were isolated from normoxic (N) OM-MSCs (N-EVs) and hypoxic (H) OM-MSCs (H-EVs) using differential centrifugation and identified by transmission electron microscopy and flow cytometry. In vitro and in vivo, both types of OM-MSC-EVs promoted the proliferation, migration, and angiogenic activities of human brain microvascular endothelial cells (HBMECs). In addition, angiogenesis-stimulatory activity in the H-EV group was significantly enhanced compared to the N-EV group. MicroRNA profiling revealed a higher abundance of miR-612 in H-EVs than in N-EVs, while miR-612 inactivation abolished the N-EV treatment benefit. To explore the roles of miR-612, overexpression and knock-down experiments were performed using a mimic and inhibitor or agomir and antagomir of miR-612. The miR-612 target genes were confirmed using the luciferase reporter assay. Gain- and loss-of-function studies allowed the validation of miR-612 (enriched in hypoxic OM-MSC-EVs) as a functional messenger that stimulates angiogenesis and represses the expression of TP53 by targeting its 3′-untranslated region. Further functional assays showed that hypoxic OM-MSC-EVs promote paracrine Hypoxia-inducible factor 1-alpha (HIF-1α)-Vascular endothelial growth factor (VEGF) signaling in HBMECs via the exosomal miR-612-TP53-HIF-1α-VEGF axis. These findings suggest that hypoxic OM-MSC-EVs may represent a promising strategy for ischemic disease by promoting angiogenesis via miR-612 transfer.

Crosslink between p53 and metastasis: focus on epithelial-mesenchymal transition, cancer stem cell, angiogenesis, autophagy, and anoikis

INTRODUCTION

P53, as a tumor suppressor gene, is believed to be one of the most mutated genes in cancer cells. The mutant forms of this protein often play a tumorigenic role in cancer cells. Recent evidence shows that p53 plays a critical role in the migration, metastasis, and invasion of cancer cells. The present article aims to investigate the molecular mechanism that induces metastasis in cancer cells generated by the mutant P53, and to highlight the compounds targeting mutant-p53 together with their clinical applications.

METHODS

A detailed literature search was conducted to find information about the role of the mutant-p53 in the processes involved in metastasis in various databases.

RESULTS

A growing body of evidence suggests that Mutant-p53 enhances tumor metastasis affecting the Epithelial-mesenchymal transition (EMT) process, cancer stem cells, angiogenesis, autophagy, anoikis, and any other mechanisms regarding metastasis.

CONCLUSIONS

Taken together, targeting mutant-p53 by altering the processes involved in metastasis could be a potential therapeutic strategy in the treatment of metastatic cancer.

Biological effects and mechanisms of matrine and other constituents of Sophora flavescens in colorectal cancer

The plant Sophora flavescens Ait. has been used in the clinical management of colorectal cancer (CRC). Its constituent compounds, notably the alkaloids matrine, oxymatrine, and sophoridine, have received considerable research attention in experimental models of CRC in vivo and in vitro. This review found that extracts of S. flavescens and/or its constituent compounds have been reported to inhibit CRC cell proliferation by inducing cell-cycle arrest at the G1 phase, inducing apoptosis via the intrinsic pathway, interfering in cancer metabolism, inhibiting metastasis and angiogenesis, regulating senescence and telomeres, regulating the tumour microenvironment and down-regulating cancer-related inflammation. In addition, matrine and oxymatrine reversed multi-drug resistance and enhanced the effects of chemotherapies. These anti-cancer effects were associated with regulation of several cellular signalling pathways including: MAPK/ERK, PI3K/AKT/mTOR, p38MAPK, NF-κB, Hippo/LATS2, TGF-β/Smad, JAK/STAT3, RhoA/ROC, and Wnt/ β-catenin pathways. These multiple actions in CRC suggest the alkaloids of S. flavescens may be therapeutic candidates for CRC management. Nevertheless, there remains considerable scope for future research into its flavonoid constituents, the effects of combinations of compounds, and the interaction between these compounds and anti-cancer drugs. In addition, more research is needed to investigate likely drug ligand-receptor interactions for each of the bioactive compounds.

PARP1 Is Targeted by miR-519a-3p and Promotes the Migration, Invasion, and Tube Formation of Ovarian Cancer Cells

Background: Poly ADP-ribose polymerase 1 (PARP1) has been discovered to be implicated in ovarian cancer (OC), but its interaction with microRNA (miR)-519a-3p remained poorly understood. This study aimed to uncover their roles and interactions in OC. Materials and Methods: Clinical tissue from OC patients and adjacent normal tissue were collected, and the survival rates of OC patients with high or low PARP1 expression were analyzed by Kaplan-Meier curve. After transfection, OC cell viability, migration, and tube formation were detected with cell counting kit-8 (CCK-8) assay, scratch assay, and tube formation assay, respectively. Target gene of miR-519a-3p and potential binding sites between them were predicted with TargetScan and confirmed using dual-luciferase reporter assay. Relative expressions of miR-519a-3p, PARP1, E-cadherin, N-cadherin, SNAIL, vascular endothelial growth factor (VEGF), and p53 were measured by quantitative real-time polymerase chain reaction and Western blot as needed. Results: PARP1 expression was upregulated in OC, which was related to poor prognosis of OC patients. Silencing PARP1 decreased PARP1 expression and suppressed viability, migration, invasion, and tube formation in OC cells, while overexpressed PARP1 did the opposite. PARP1 was the target gene of miR-519a-3p, and it reversed the effects of miR-519a-3p on the migration, invasion, and tube formation of OC cells by upregulating the expressions of PAR, PARP1, N-cadherin, SNAIL, and VEGF and downregulating those of E-cadherin and p53. Conclusion: PARP1, a target gene of miR-519a-3p, promoted the migration, invasion, and tube formation of OC cells, providing a possible therapeutic target for treatment of OC patients.

The Interplay Between Tumor Suppressor p53 and Hypoxia Signaling Pathways in Cancer

Hypoxia is a hallmark of solid tumors and plays a critical role in different steps of tumor progression, including proliferation, survival, angiogenesis, metastasis, metabolic reprogramming, and stemness of cancer cells. Activation of the hypoxia-inducible factor (HIF) signaling plays a critical role in regulating hypoxic responses in tumors. As a key tumor suppressor and transcription factor, p53 responds to a wide variety of stress signals, including hypoxia, and selectively transcribes its target genes to regulate various cellular responses to exert its function in tumor suppression. Studies have demonstrated a close but complex interplay between hypoxia and p53 signaling pathways. The p53 levels and activities can be regulated by the hypoxia and HIF signaling differently depending on the cell/tissue type and the severity and duration of hypoxia. On the other hand, p53 regulates the hypoxia and HIF signaling at multiple levels. Many tumor-associated mutant p53 proteins display gain-of-function (GOF) oncogenic activities to promote cancer progression. Emerging evidence has also shown that GOF mutant p53 can promote cancer progression through its interplay with the hypoxia and HIF signaling pathway. In this review, we summarize our current understanding of the interplay between the hypoxia and p53 signaling pathways, its impact upon cancer progression, and its potential application in cancer therapy.

P21 is not a prognostic marker for rectal cancer - five-year follow up study of rectal cancer in stages I-IV

The p21 participates in the regulation of DNA repair and replication, and modulation of apoptosis as well. After DNA damage, the p53-dependent induction of p21 results in cell cycle arrest or could trigger cell apoptosis. The objective of the study was the assessment of p21 immunoreactivity in rectal cancer and the estimation of relationships with clinical outcome especially as predictor of poor outcome. While applying the ruling in and out criteria, 102 patients were incorporated to the study, with stage I–IV rectal cancer who had undergone surgery in a planned mode during 2005–2011. The follow-up covered 5 years period from surgery date. Conventional immunohistochemistry were performed using antibody against p21 (p21WAF1 (Clone H252) to detect overexpression targeted receptor. The analysis showed no statistically significant differences in the survival curves of patients in groups with immunoreactivity of p21 protein at 0; 1; 2; 3 (p = 0.6453 in the log-rank test), also is not a significant risk factor for death (HR = 0.915, p = 0.7842) and for tumor dissemination (HR = 0.94, p = 0.9426). Our study leads to the conclusion that the probability of survival does not depend on p21 expression and do not authorize the importance of p21 immunoreactivity in the detection and monitoring of rectal cancer treatment.

Ecological and Evolutionary Consequences of Anticancer Adaptations

Cellular cheating leading to cancers exists in all branches of multicellular life, favoring the evolution of adaptations to avoid or suppress malignant progression, and/or to alleviate its fitness consequences. Ecologists have until recently largely neglected the importance of cancer cells for animal ecology, presumably because they did not consider either the potential ecological or evolutionary consequences of anticancer adaptations. Here, we review the diverse ways in which the evolution of anticancer adaptations has significantly constrained several aspects of the evolutionary ecology of multicellular organisms at the cell, individual, population, species, and ecosystem levels and suggest some avenues for future research.

Amarogentin Inhibits Liver Cancer Cell Angiogenesis after Insufficient Radiofrequency Ablation via Affecting Stemness and the p53-Dependent VEGFA/Dll4/Notch1 Pathway

Background

Whether and how amarogentin suppresses the angiogenesis effect in liver cancer cells after insufficient radiofrequency ablation (iRFA) are still poorly studied.

Methods

The number of liver cancer stem cells (LCSCs) and the level of vascular endothelial growth factor A (VEGFA) were assessed in liver cancer tissue after iRFA. Then, CD133-positive cells were detected in iRFA models of HepG2 and Huh7 cell lines treated with amarogentin. Tube formation assays were applied to observe the antiangiogenesis effects of amarogentin. In addition, the angiogenesis-related molecules p53, delta-like ligand 4 (Dll4), and Notch1 were detected in the iRFA cells and mouse models treated with amarogentin.

Results

The mRNA and protein expression levels of CD133 and VEGFA were significantly higher in the residual liver cancer tissue than in the liver cancer tissues treated by hepatectomy. Amarogentin then markedly decreased the percentage of CD133-positive cells in the iRFA model in both HepG2 and Huh7 cell lines. The number of tubules formed by human umbilical vein endothelial cells (HUVECs) was significantly decreased by amarogentin. Inversely, the antiangiogenesis effect of amarogentin was counteracted after p53 silencing in the iRFA cell models.

Conclusion

Amarogentin prevents the malignant transformation of liver cancer after iRFA via affecting stemness and the p53-dependent VEGFA/Dll4/Notch1 pathway to inhibit cancer cell angiogenesis.

PSMB8 inhibition decreases tumor angiogenesis in glioblastoma through vascular endothelial growth factor A reduction

Glioblastoma, also known as glioblastoma multiforme (GBM), is a fast‐growing tumor and the most aggressive brain malignancy. Proteasome subunit beta type‐8 (PSMB8) is one of the 17 essential subunits for the complete assembly of the 20S proteasome complex. The aim of the present study was to evaluate the role of PSMB8 expression in GBM progression and angiogenesis. PSMB8 expression in glioblastoma LN229 and U87MG was knocked down by siRNA or inducible shRNA both in vitro and in vivo. After PSMB8 reduction, cell survival, migration, invasion, angiogenesis, and the related signaling cascades were evaluated. An orthotopic mouse tumor model was also provided to examine the angiogenesis within tumors. A GEO profile analysis indicated that high expression of PSMB8 mRNA in GBM patients was correlated with a low survival rate. In immunohistochemistry analysis, PSMB8 expression was higher in high‐grade than in low‐grade brain tumors. The proliferation, migration, and angiogenesis of human GBM cells were decreased by PSMB8 knockdown in vitro. Furthermore, phosphorylated focal adhesion kinase (p‐FAK), p‐paxillin, MMP2, MMP9, and cathepsin B were significantly reduced in LN229 cells. Integrin β1 and β3 were reduced in HUVEC after incubation with LN229‐conditioned medium. In an orthotopic mouse tumor model, inducible knockdown of PSMB8 reduced the expression of vascular endothelial growth factor (VEGF), VEGF receptor, and CD31 as well as the progression of human glioblastoma. In this article, we demonstrated the role of PSMB8 in glioblastoma progression, especially neovascularization in vitro and in vivo. These results may provide a target for the anti–angiogenic effect of PSMB8 in glioblastoma therapy in the future.

Interactions of Vascular Endothelial Growth Factor and p53 with miR-195 in Thyroid Carcinoma: Possible Therapeutic Targets in Aggressive Thyroid Cancers

BACKGROUND

The clinical pathological features, as well as the cellular mechanisms of miR-195, have not been investigated in thyroid carcinoma.

OBJECTIVE

The aim of this study is to identify the interactions of vascular endothelial growth factor (VEGF), p53 and miR-195 in thyroid carcinoma. The clinical and pathological features of miR-195 were also investigated.

METHODS

The expression levels of miR-195 were identified in 123 primary thyroid carcinomas, 40 lymph nodes with metastatic papillary thyroid carcinomas and seven non-neoplastic thyroid tissues (controls) as well as two thyroid carcinoma cell lines, B-CPAP (from metastasizing human papillary thyroid carcinoma) and MB-1 (from anaplastic thyroid carcinoma), by the real-time polymerase chain reaction. Using Western blot and immunofluorescence, the effects of exogenous miR-195 on VEGF-A and p53 protein expression levels were examined. Then, cell cycle and apoptosis assays were performed to evaluate the roles of miR-195 in cell cycle progression and apoptosis.

RESULTS

The expression of miR-195 was downregulated in majority of the papillary thyroid carcinoma tissue as well as in cells. Introduction of exogenous miR-195 resulted in downregulation of VEGF-A and upregulation of p53 protein expressions. Upregulation of miR-195 in thyroid carcinoma cells resulted in cell cycle arrest. Moreover, we demonstrated that miR-195 inhibits cell cycle progression by induction of apoptosis in the thyroid carcinoma cells.

CONCLUSION

Our findings showed for the first time that miR-195 acts as a tumour suppressor and regulates cell cycle progression and apoptosis by targeting VEGF-A and p53 in thyroid carcinoma. The current study exhibited that miR-195 might represent a potential therapeutic target for patients with thyroid carcinomas having aggressive clinical behaviour.

Reactivation of Epstein-Barr Virus by HIF-1α Requires p53

We previously reported that the cellular transcription factor hypoxia-inducible factor 1α (HIF-1α) binds a hypoxia response element (HRE) located within the promoter of Epstein-Barr virus's (EBV's) latent-lytic switch BZLF1 gene, Zp, inducing viral reactivation. In this study, EBV-infected cell lines derived from gastric cancers and Burkitt lymphomas were incubated with HIF-1α-stabilizing drugs: the iron chelator deferoxamine (Desferal [DFO]), a neddylation inhibitor (pevonedistat [MLN-4924]), and a prolyl hydroxylase inhibitor (roxadustat [FG-4592]). DFO and MLN-4924, but not FG-4592, induced accumulation of both lytic EBV proteins and phosphorylated p53 in cell lines that contain a wild-type p53 gene. FG-4592 also failed to activate transcription from Zp in a reporter assay despite inducing accumulation of HIF-1α and transcription from another HRE-containing promoter. Unexpectedly, DFO failed to induce EBV reactivation in cell lines that express mutant or no p53 or when p53 expression was knocked down with short hairpin RNAs (shRNAs). Likewise, HIF-1α failed to activate transcription from Zp when p53 was knocked out by CRISPR-Cas9. Importantly, DFO induced binding of p53 as well as HIF-1α to Zp in chromatin immunoprecipitation (ChIP) assays, but only when the HRE was present. Nutlin-3, a drug known to induce accumulation of phosphorylated p53, synergized with DFO and MLN-4924 in inducing EBV reactivation. Conversely, KU-55933, a drug that inhibits ataxia telangiectasia mutated, thereby preventing p53 phosphorylation, inhibited DFO-induced EBV reactivation. Lastly, activation of Zp transcription by DFO and MLN-4924 mapped to its HRE. Thus, we conclude that induction of BZLF1 gene expression by HIF-1α requires phosphorylated, wild-type p53 as a coactivator, with HIF-1α binding recruiting p53 to Zp.IMPORTANCE EBV, a human herpesvirus, is latently present in most nasopharyngeal carcinomas, Burkitt lymphomas, and some gastric cancers. To develop a lytic-induction therapy for treating patients with EBV-associated cancers, we need a way to efficiently reactivate EBV into lytic replication. EBV's BZLF1 gene product, Zta, usually controls this reactivation switch. We previously showed that HIF-1α binds the BZLF1 gene promoter, inducing Zta synthesis, and HIF-1α-stabilizing drugs can induce EBV reactivation. In this study, we determined which EBV-positive cell lines are reactivated by classes of HIF-1α-stabilizing drugs. We found, unexpectedly, that HIF-1α-stabilizing drugs only induce reactivation when they also induce accumulation of phosphorylated, wild-type p53. Fortunately, p53 phosphorylation can also be provided by drugs such as nutlin-3, leading to synergistic reactivation of EBV. These findings indicate that some HIF-1α-stabilizing drugs may be helpful as part of a lytic-induction therapy for treating patients with EBV-positive malignancies that contain wild-type p53.

Small Extracellular Vesicles from Human Fetal Dermal Cells and Their MicroRNA Cargo: KEGG Signaling Pathways Associated with Angiogenesis and Wound Healing

The use of cell secreted factors in clinical settings could be an alternative to conventional cell therapy, with the advantage of limiting concerns generally associated with traditional cell transplantation, such as tumorigenicity, immunoreactivity, and carrying of infections. Based on our published data, we predict a potential role for extracellular vesicles (EVs) in contributing to the proangiogenic activity of human fetal dermal cell secretome. Depletion of nanosized EVs from secretome significantly impaired its ability to induce formation of mesh-like structures in vitro. The isolated EVs were characterized for size and concentration by nanoparticle tracking analysis, and for protein markers (Rab5⁺, Alix⁺, CD63⁺, and calnexin⁻). The microRNA profile of EVs revealed 87 microRNAs significantly upregulated (≥15-fold increase) in fetal compared to adult dermal cell-derived EVs. Interestingly, these upregulated microRNAs included microRNAs with a validated role in angiogenesis according to literature. Moreover, the DIANA-TarBase v7.0 analysis confirmed enrichment in the KEGG signaling pathways associated with angiogenesis and wound healing, with the identification of putative target genes including thrombospondin 1. To validate the in silico data, EVs were also characterized for total protein contents. When tested in in vitro angiogenesis, fetal dermal cell-derived EVs were more effective than their adult counterpart in inducing formation of complete mesh-like structures. Furthermore, treatment of fibroblasts with fetal dermal-derived EVs determined a 4-fold increase of thrombospondin 1 protein amounts compared with the untreated fibroblasts. Finally, visualization of CSFE-labeled EVs in the cytosol of target cells suggested a successful uptake of these particles at 4-8 hours of incubation. We conclude that EVs are important contributors of the proangiogenic effect of fetal dermal cell secretome. Hence, EVs could also serve as vehicle for a successful delivery of microRNAs or other molecules of therapeutic interest to target cells.

TP53 Mutation Analysis in Gastric Cancer and Clinical Outcomes of Patients with Metastatic Disease Treated with Ramucirumab/Paclitaxel or Standard Chemotherapy

Loss of p53 promotes vascular endothelial growth factor (VEGF)-A up-regulation and the angiogenic potential of cancer cells. We investigated TP53 somatic mutations in 110 primary gastric adenocarcinomas of two retrospective metastatic series including 48 patients treated with second-line Ramucirumab/Paclitaxel and 62 patients who received first-line chemotherapy with Cisplatin or Oxaliplatin plus 5-Fluorouracil. Missense mutations were classified by tumor protein p53 (TP53) mutant-specific residual transcriptional activity scores (TP53_RTAS) and used to stratify patients into two groups: transcriptionally TP53_Active and TP53_Inactive. The primary endpoint was overall survival (OS). An additional analysis was addressed to measure VEGF/VEGF receptor 2 (VEGFR2) expression levels in relation to the TP53_RTAS. In the Ramucirumab/Paclitaxel group, 29/48 (60.4%) patients had TP53 mutations. Ten patients with TP53_Inactive mutations showed better OS than carriers of other TP53 mutations. This effect was retained in the multivariate model analysis (Hazard Ratio = 0.29, 95% confidence interval = 0.17–0.85, p = 0.02). In the chemotherapy group, 41/62 (66%) patients had TP53 mutations, and the 11 carriers of TP53_Inactive mutations showed the worst OS (Hazard Ratio = 2.64, 95% confidence interval = 1.17–5.95, p = 0.02). VEGF-A mRNA expression levels were significantly increased in TP53_Inactive cases. Further studies are warranted to explore the effect of TP53_Inactive mutations in different anti-cancer regimens. This information would lead to new tailored therapy strategies for this lethal disease.

Discussion of some 'knowns' and some 'unknowns' about the tumour suppressor p53

Activation of the tumour suppressor p53 upon cellular stress can induce a number of different cellular processes. The diverse actions of these processes are critical for the protective function of p53 in preventing the development of cancer. However, it is still not fully understood which process(es) activated by p53 is/are critical for tumour suppression and how this might differ depending on the type of cells undergoing neoplastic transformation and the nature of the drivers of oncogenesis. Moreover, it is not clear why upon activation of p53 some cells undergo cell cycle arrest and senescence whereas others die by apoptosis. Here we discuss some of the cellular processes that are crucial for p53-mediated tumour suppression and the factors that could impact cell fate upon p53 activation. Finally, we describe therapies aimed either at activating wild-type p53 or at changing the behaviour of mutant p53 to unleash tumour growth suppressive processes for therapeutic benefit in malignant disease.

Tumor Endothelial Cell-A Biological Tool for Translational Cancer Research

Going from bench to bedside is a simplified description of translational research, with the ultimate goal being to improve the health status of mankind. Tumor endothelial cells (TECs) perform angiogenesis to support the growth, establishment, and dissemination of tumors to distant organs. TECs have various features that distinguish them from normal endothelial cells, which include alterations in gene expression patterns, higher angiogenic and metabolic activities, and drug resistance tendencies. The special characteristics of TECs enhance the vulnerability of tumor blood vessels toward antiangiogenic therapeutic strategies. Therefore, apart from being a viable therapeutic target, TECs would act as a better mediator between the bench (i.e., angiogenesis research) and the bedside (i.e., clinical application of drugs discovered through research). Exploitation of TEC characteristics could reveal unidentified strategies of enhancing and monitoring antiangiogenic therapy in the treatment of cancer, which are discussed in this review.

Integrative Clustering Reveals a Novel Subtype of Soft Tissue Sarcoma With Poor Prognosis

Background

Soft tissue sarcomas (STSs) are heterogeneous at the clinical and molecular level and need to be further sub-clustered for treatment and prognosis.

Materials And Methods

STSs were sub-clustered based on RNAseq and miRNAseq data extracted from The Cancer Genome Atlas (TCGA) through the combined process of similarity network fusion (SNF) and consensus clustering (CC). The expression and clinical characteristics of each sub-cluster were analyzed. The genes differentially expressed (lncRNAs, miRNAs, and mRNAs) between the poor prognosis and good prognosis clusters were used to construct a competing endogenous RNA (ceRNA) network. Functional enrichment analysis was conducted and a hub network was extracted from the constructed ceRNA network.

Results

A total of 247 STSs were classified into three optimal sub-clusters, and patients in cluster 2 (C2) had a significantly lower rate of survival. A ceRNA network with 91 nodes and 167 edges was constructed according to the hypothesis of ceRNA. Functional enrichment analysis revealed that the network was mainly associated with organism development functions. Moreover, LncRNA (KCNQ1OT1)-miRNA (has-miR-29c-3p)-mRNA (JARID2, CDK8, DNMT3A, TET1)-competing endogenous gene pairs were identified as hub networks of the ceRNA network, in which each component showed survival significance.

Conclusion

Integrative clustering analysis revealed that the STSs could be clustered into three sub-clusters. The ceRNA network, especially the subnetwork LncRNA (KCNQ1OT1)-miRNA (has-miR-29c-3p)-mRNA (JARID2, CDK8, DNMT3A, TET1) was a promising therapeutic target for the STS sub-cluster associated with a poor prognosis.

Molecular Links Between Angiogenesis and Neuroendocrine Phenotypes in Prostate Cancer Progression

As a common therapy for prostate cancer, androgen deprivation therapy (ADT) is effective for the majority of patients. However, prolonged ADT promotes drug resistance and progression to an aggressive variant with reduced androgen receptor signaling, so called neuroendocrine prostate cancer (NEPC). Until present, NEPC is still poorly understood, and lethal with no effective treatments. Elevated expression of neuroendocrine related markers and increased angiogenesis are two prominent phenotypes of NEPC, and both of them are positively associated with cancers progression. However, direct molecular links between the two phenotypes in NEPC and their mechanisms remain largely unclear. Their elucidation should substantially expand our knowledge in NEPC. This knowledge, in turn, would facilitate the development of effective NEPC treatments. We recently showed that a single critical pathway regulates both ADT-enhanced angiogenesis and elevated expression of neuroendocrine markers. This pathway consists of CREB1, EZH2, and TSP1. Here, we seek new insights to identify molecules common to pathways promoting angiogenesis and neuroendocrine phenotypes in prostate cancer. To this end, our focus is to summarize the literature on proteins reported to regulate both neuroendocrine marker expression and angiogenesis as potential molecular links. These proteins, often described in separate biological contexts or diseases, include AURKA and AURKB, CHGA, CREB1, EZH2, FOXA2, GRK3, HIF1, IL-6, MYCN, ONECUT2, p53, RET, and RB1. We also present the current efforts in prostate cancer or other diseases to target some of these proteins, which warrants testing for NEPC, given the urgent unmet need in treating this aggressive variant of prostate cancer.

Anticancer Effect of Deuterium Depleted Water - Redox Disbalance Leads to Oxidative Stress

Despite the convincing empirical evidence that deuterium depleted water (DDW, 25-125 ppm deuterium) has anticancer effect, the molecular mechanism remains unclear. Here, redox proteomics investigation of the DDW action in A549 cells revealed an increased level of oxidative stress, whereas expression proteomics in combination with thermal profiling uncovered crucial role of mitochondrial proteins. In the proposed scenario, reversal of the normally positive deuterium gradient across the inner membrane leads to an increased export of protons from the matrix to intermembrane space and an increase in the mitochondrial membrane potential, enhancing the production of reactive oxygen species (ROS). The resulting oxidative stress leads to slower growth and can induce apoptosis. However, further deuterium depletion in ambient water triggers a feedback mechanism, which leads to restoration of the redox equilibrium and resumed growth. The DDW-induced oxidative stress, verified by traditional biochemical assays, may be helpful as an adjuvant to ROS-inducing anticancer therapy.

Mutated TP53 is a marker of increased VEGF expression: analysis of 7,525 pan-cancer tissues

Anti-angiogenic therapies are an important class of anti-cancer treatment drugs. However, their efficacy is limited to certain tumors and would benefit from identifying a biomarker predictive of therapeutic response. TP53 (tumor protein p53) is a tumor suppressor gene frequently mutated in cancer and implicated in cell-cycle regulation, apoptosis, and angiogenesis. Data from 7,525 unique tumor samples (representing 30 tumor cohorts) were retrieved from the TCGA database to analyze the relationship between TP53-mutation status and VEGFA (vascular endothelial growth factor A) expression. Univariate analyses were done using a Mann-Whitney univariate test or Fisher's exact test. Parameters with a p-value (p)≤0.1 in univariate analysis were selected for follow-up multivariate analyses, including TP53-mutation status, cancer cohorts, cancer subtypes, and VEGFA expression. Our analysis demonstrates statistically significant increases in VEGFA mRNA tissue expression in TP53-mutated adenocarcinomas (but not in squamous cancers) compared to TP53 wild-type tumors. This association holds true in multivariate analyses and remains independent of HIF-1α and MDM2 overexpression. Our findings provide additional evidence that TP53 mutations are linked to the VEGF pathway, potentially offering insight into the mechanism behind increased sensitivity to anti-angiogenic therapies observed in some TP53-mutant tumors.

Combination of Epigallocatechin-3-gallate and Silibinin: A Novel Approach for Targeting Both Tumor and Endothelial Cells

Despite promising benefits, anti-angiogenic strategies have revealed several drawbacks, which necessitate development of novel approaches in cancer therapy strategies including non-small-cell lung cancer, as one of the leading causes of cancer death, all over the world. Combination of flavonoids could be a safe and effective option to synergize their impact on mechanisms controlling tumor angiogenesis. In this study, we have investigated the plausible synergism of epigallocatechin-3-gallate (EGCG) and silibinin on endothelial cells, for the first time. Cell viability and migration were evaluated by survival and wound healing assays, respectively. Then, we assessed the expression of VEGF, VEGFR2, and miR-17-92 cluster using real-time polymerase chain reaction in endothelial-tumor cell and endothelial-fibroblast coculture models. EGCG ± silibinin suppressed endothelial and lung tumor cell migration in lower than 50% toxic doses. VEGF, VEGFR2, and pro-angiogenic members of the miR-17-92 cluster were downregulated upon treatments. Specifically, the combination treatment upregulated an anti-angiogenic member of the cluster, miR-19b. Our data provides evidence to utilize the EGCG and silibinin combination as a novel approach to target tumor angiogenesis in the future.

Telomerase Plays a Pivotal Role in Collateral Growth Under Ischemia by Suppressing Age-Induced Oxidative Stress, Expression of p53, and Pro-Apoptotic Proteins

Aging is not only a major risk factor for impaired collateral growth under ischemia but also shortens the telomere length, which is regulated by telomerase. We examined the role of telomerase activity during impaired collateral growth during aging in ischemic skeletal muscle. Unilateral hind limb ischemia was generated in old, young, and old mice chronically administered a telomerase activator. In old mice, blood flow recovery and capillary density development in ischemic hind limbs were reduced compared to those in young mice, and these changes were restored to equal levels by administration of TA-65, a telomerase activator. During the early phase of ischemic muscle changes in old mice, telomerase reverse transcriptase expression and telomerase activity were both low compared to those in young mice and old mice treated with TA-65. Levels of reactive oxygen species (ROS), DNA double-strand breaks, and expression of p53, p16, and Bax/Bcl-2 were all elevated in ischemic muscles of old mice compared to those in the muscles of young mice and old mice treated with TA-65 treatment; these factors were maintained at low levels equivalent to those seen in young mice during the experiment. Expression of HIF1α/vascular endothelial growth factor (VEGF) and PGC1α were decreased in old mice compared to those in young mice and old mice treated with TA-65. Collateral growth under ischemic conditions is impaired in aged animals due to low telomerase activity, increased ROS, resultant DNA damage, and expression of tumor suppressor and pro-apoptotic proteins. These data suggest that telomerase activation enhances collateral growth and rescues ischemic tissue in old individuals.

Egr1 mediates retinal vascular dysfunction in diabetes mellitus via promoting p53 transcription

Objectives

This study focused on investigating the expression and underlying molecular mechanism of early growth response 1 (Egr1) in diabetic retinopathy.

Methods

A microarray assay was applied to examine differentially expressed genes in the retina tissues of normal rats, as well as in those of streptozotocin‐induced diabetic rats. Human retinal vascular endothelial cells (HRVECs) transfected with sh‐NC, sh‐Egr1 or sh‐Egr1+ pVax1‐p53 were cultured under high‐glucose conditions and then used to explore the role of Egr1 in vitro. The effect of Egr1 on retinal vascular dysfunction caused by diabetes was examined by sh‐Egr1 administration in vivo

Results

Early growth response 1 was found to be up‐regulated in the retinas of diabetic rats compared to those of normal rats. Down‐regulation of Egr1 in HRVECs under high‐glucose conditions inhibited the apoptosis, migration and tube formation in vitro. Moreover, sh‐Egr1 partially reduced the injurious effects of hyperglycaemia on retinal vascular function by decreasing apoptotic cells and microvascular formation in vivo. The reduction of Egr1 evidently down‐regulated the p53 expression. Overexpression of p53 rescued the inhibition of sh‐Egr1 in HRVECs under high‐glucose concentration on apoptosis, migration and tube formation in vitro.

Conclusion

Down‐regulation of Egr1 partially reduced the injurious effects of hyperglycaemia on retinal vascular function via inhibiting p53 expression.

Outcome analysis of Phase I trial patients with metastatic KRAS and/or TP53 mutant non-small cell lung cancer

KRAS and TP53 mutations, which are the most common genetic drivers of tumorigenesis, are still considered undruggable targets. Therefore, we analyzed these genetic aberrations in metastatic non-small cell lung cancer (NSCLC) for the development of potential therapeutics. One hundred eighty-five consecutive patients with metastatic NSCLC in a phase 1 trial center were included. Their genomic aberrations, clinical characteristics, survivals, and phase 1 trial therapies were analyzed. About 10%, 18%, 36%, and 36% of the patients had metastatic KRAS+/TP53+, KRAS+/TP53-,KRAS-/TP53+, and KRAS-/TP53- NSCLC, respectively. The most common concurrent genetic aberrations beside KRAS and/or TP53 (>5%) were KIT, epidermal growth factor receptor, PIK3CA, c-MET, BRAF, STK11, ATM, CDKN2A, and APC. KRAS+/TP53+ NSCLC did not respond well to the phase 1 trial therapy and was associated with markedly worse progression-free (PFS) and overall (OS) survivals than the other three groups together. KRAS hotspot mutations at locations other than codon G12 were associated with considerably worse OS than those at this codon. Gene aberration-matched therapy produced prolonged PFS and so was anti-angiogenesis in patients with TP53 mutations. Introduction of the evolutionary action score system of TP53 missense mutations enabled us to identify a subgroup of NSCLC patients with low-risk mutant p53 proteins having a median OS duration of 64.5 months after initial diagnosis of metastasis. These data suggested that patients with metastatic dual KRAS+/TP53+ hotspot-mutant NSCLC had poor clinical outcomes. Further analysis identified remarkably prolonged survival in patients with low-risk mutant p53 proteins, which warrants confirmatory studies.

Metabolomics profiles delineate uridine deficiency contributes to mitochondria-mediated apoptosis induced by celastrol in human acute promyelocytic leukemia cells

Celastrol, extracted from “Thunder of God Vine”, is a promising anti-cancer natural product. However, its effect on acute promyelocytic leukemia (APL) and underlying molecular mechanism are poorly understood. The purpose of this study was to explore its effect on APL and underlying mechanism based on metabolomics. Firstly, multiple assays indicated that celastrol could induce apoptosis of APL cells via p53-activated mitochondrial pathway. Secondly, unbiased metabolomics revealed that uridine was the most notable changed metabolite. Further study verified that uridine could reverse the apoptosis induced by celastrol. The decreased uridine was caused by suppressing the expression of gene encoding Dihydroorotate dehydrogenase, whose inhibitor could also induce apoptosis of APL cells. At last, mouse model confirmed that celastrol inhibited tumor growth through enhanced apoptosis. Celastrol could also decrease uridine and DHODH protein level in tumor tissues. Our in vivo study also indicated that celastrol had no systemic toxicity at pharmacological dose (2 mg/kg, i.p., 21 days). Altogether, our metabolomics study firstly reveals that uridine deficiency contributes to mitochondrial apoptosis induced by celastrol in APL cells. Celastrol shows great potential for the treatment of APL.

Inactivation of the MDM2 RING domain enhances p53 transcriptional activity in mice

The MDM2 RING domain harbors E3 ubiquitin ligase activity critical for regulating the degradation of tumor suppressor p53, which controls many cellular pathways. The MDM2 RING domain also is required for an interaction with MDMX. Mice containing a substitution in the MDM2 RING domain, MDM2^C462A, disrupting MDM2 E3 function and the MDMX interaction, die during early embryogenesis that can be rescued by p53 deletion. To investigate whether MDM2^C462A, which retains p53 binding, has p53-suppressing activity, we generated Mdm2^C462A/C462A ;p53^ER/- mice, in which we replaced the endogenous p53 alleles with an inducible p53^ER/- allele, and compared survival with that of similarly generated Mdm2^-/-;p53^ER/- mice. Adult Mdm2-null mice died ∼7 days after tamoxifen-induced p53 activation, indicating that in the absence of MDM2, MDMX cannot suppress p53. Surprisingly, Mdm2^C462A/C462A ;p53^ER/- mice died ∼5 days after tamoxifen injection, suggesting that p53 activity is higher in the presence of MDM2^C462A than in the absence of MDM2. Indeed, in MDM2^C462A-expressing mouse tissues and embryonic fibroblasts, p53 exhibited higher transcriptional activity than in those expressing no MDM2 or no MDM2 and MDMX. This observation indicated that MDM2^C462A not only is unable to suppress p53 but may have gained the ability to enhance p53 activity. We also found that p53 acetylation, a measure of p53 transcriptional activity, was higher in the presence of MDM2^C462A than in the absence of MDM2. These results reveal an unexpected role of MDM2^C462A in enhancing p53 activity and suggest the possibility that compounds targeting MDM2 RING domain function could produce even more robust p53 activation.

Comparative analysis of the microRNA transcriptome between yak and cattle provides insight into high-altitude adaptation

Extensive and in-depth investigations of high-altitude adaptation have been carried out at the level of morphology, anatomy, physiology and genomics, but few investigations focused on the roles of microRNA (miRNA) in high-altitude adaptation. We examined the differences in the miRNA transcriptomes of two representative hypoxia-sensitive tissues (heart and lung) between yak and cattle, two closely related species that live in high and low altitudes, respectively. In this study, we identified a total of 808 mature miRNAs, which corresponded to 715 pre-miRNAs in the two species. The further analysis revealed that both tissues showed relatively high correlation coefficient between yak and cattle, but a greater differentiation was present in lung than heart between the two species. In addition, miRNAs with significantly differentiated patterns of expression in two tissues exhibited co-operation effect in high altitude adaptation based on miRNA family and cluster. Functional analysis revealed that differentially expressed miRNAs were enriched in hypoxia-related pathways, such as the HIF-1α signaling pathway, the insulin signaling pathway, the PI3K-Akt signaling pathway, nucleotide excision repair, cell cycle, apoptosis and fatty acid metabolism, which indicated the important roles of miRNAs in high altitude adaptation. These results suggested the diverse degrees of miRNA transcriptome variation in different tissues between yak and cattle, and suggested extensive roles of miRNAs in high altitude adaptation.