A novel loss-of-function mutation in TP53 in an endometrial cancer cell line and uterine papillary serous carcinoma model

A review of basic to clinical targeted therapy and immunotherapy in uterine serous cancer

Uterine serous carcinomas show more frequent mutations of TP53, FBXW7, PIK3CA, and PP2R1A. Furthermore, cyclin-dependent kinase, human epidermal growth factor receptor 2, phosphatidylinositol 3-kinase/protein kinase B, and mammalian target of rapamycin signaling pathways are involved in uterine serous carcinoma progression. However, most patients with uterine serous carcinoma develop chemoresistance to paclitaxel and carboplatin. Moreover, uterine serous carcinoma shows immunosuppressive microenvironment with lower frequency of microsatellite instability. However, some clinical trials of human epidermal growth factor receptor 2/neu and WEE1 targeted therapies showed good effects in prolonging the survival in patients with uterine serous carcinoma. More effective targeted therapies and immunotherapies need to be developed in recurrent uterine serous carcinomas.

Tp53 haploinsufficiency is involved in hotspot mutations and cytoskeletal remodeling in gefitinib-induced drug-resistant EGFRL858R-lung cancer mice

Tumor heterogeneity is the major factor for inducing drug resistance. p53 is the major defender to maintain genomic stability, which is a high proportion mutated in most of the cancer types. In this study, we established in vivo animal models of gefitinib-induced drug-resistant lung cancer containing EGFR^L858R and EGFR^L858R*Tp53^+/- mice to explore the molecular mechanisms of drug resistance by studying the genomic integrity and global gene expression. The cellular morphology of the lung tumors between gefitinib-induced drug-resistant mice and drug-sensitive mice were very different. In addition, in drug-resistant mice, the expression of many cytoskeleton-related genes were changed, accompanied by decreased amounts of actin filaments and increased amounts of microtubule, indicating that significant cytoskeletal remodeling is induced in gefitinib-induced drug-resistant EGFR^L858R and EGFR^L858R*Tp53^+/- lung cancer mice. The gene expression profiles and involved pathways were different in gefitinib-sensitive, gefitinib-resistant and Tp53^+/--mice. Increases in drug resistance and nuclear size (N/C ratio) were found in EGFR^L858R*Tp53^+/- drug-resistant mice. Mutational hotspot regions for drug resistance via Tp53^+/+- and Tp53^+/--mediated pathways are located on chromosome 1 and chromosome 11, respectively, and are related to prognosis of lung cancer cohorts. This study not only builds up a gefitinib-induced drug-resistant EGFR^L858R lung cancer animal model, but also provides a novel mutation profile in a Tp53^+/+- or Tp53^+/--mediated manner and induced cytoskeleton remodeling during drug resistance, which could contribute to the prevention of drug resistance during cancer therapy.

Potential Molecular Mechanism of Guishen Huoxue Decoction against Intrauterine Adhesion Based on Network Pharmacology

Objective

Intrauterine adhesion (IUA) represents an endometrial repair disorder that is associated with menstrual disorders, recurrent pregnancy loss, and infertility. This study aimed to explore the underlying biological mechanisms of Guishen Huoxue decoction for the treatment of IUA based on network pharmacology.

Methods

The selection of active compounds for Guishen Huoxue decoction and prediction of relevant targets were performed by the TCMSP and Swiss Target Prediction databases, respectively. The targets of IUA were obtained by three databases, including Online Mendelian Inheritance in Man (OMIM), DisGeNET, and GeneCards. The drug-disease regulatory network was constructed via Cytoscape software, following the acquisition of common genes of active compounds of drug Guishen Huoxue decoction and disease IUA, which was carried out through Venny software. Protein-protein interaction (PPI) network and function enrichment analyses were performed.

Results

According to the data obtained from TCMSP, a total of 200 potential active compounds of Guishen Huoxue decoction and their related targets (1068) were screened by the Swiss Target Prediction database. 1303 disease targets and 134 common targets were identified. The drug-disease regulatory network showed that 165 active compounds were found to be involved in the treatment of IUA. Among 134 common targets, AKT1, SRC, TP53, VEGFA, and IL-6 were predicted as core genes against IUA. PI3K-Akt, Rap1, Ras, and AGE-RAGE were the main signaling pathways that participated in the treatment of Guishen Huoxue decoction for IUA.

Conclusion

The active compounds of Guishen Huoxue decoction confer therapeutic effects against IUA by regulating fibrosis, inflammation, and oxidative stress through major signaling pathways such as PI3K-Akt and AGE-RAGE.

Bioinformatic profiling identifies prognosis-related genes in the immune microenvironment of endometrial carcinoma

Endometrial carcinoma (EC) is a common malignancy of female genital system which exhibits a unique immune profile. It is a promising strategy to quantify immune patterns of EC for predicting prognosis and therapeutic efficiency. Here, we attempted to identify the possible immune microenvironment-related prognostic markers of EC. We obtained the RNA sequencing and corresponding clinical data of EC from TCGA database. Then, 3 immune scores based on the Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression data (ESTIMATE) algorithm were computed. Correlation between above ESTIMATE scores and other immune-related scores, molecular subtypes, prognosis, and gene mutation status (including BRCA and TP53) were further analyzed. Afterwards, gene modules associated with the ESTIMATE scores were screened out through hierarchical clustering analysis and weighted gene co-expression network analysis (WGCNA). Differentially expressed analysis was performed and genes shared by the most relevant modules were found out. KEGG pathway enrichment analysis was conducted to explore the biological functions of those genes. Survival analysis was carried out to identify prognostic immune-related genes and GSE17025 database was further used to confirm the correlation between immune-related genes and the ImmuneScore. The immune-related scores based on ESTIMATE algorithm was closely related to the immune microenvironment of EC. 3 gene modules that had the closest correlations with 3 ESTIMATE scores were obtained. 109 immune-related genes were preliminarily found out and 29 pathways were significantly enriched, most of which were associated with immune response. Univariate survival analysis revealed that there were 14 genes positively associated with both OS and PFS. Among which, 11 genes showed marked correlations with ImmuneScore values in GSE17025 database. Our current study profiled the immune status and identified 14 novel immune-related prognostic biomarkers for EC. Our findings may help to investigate the complicated tumor microenvironment and develop novel individualized therapeutic targets for EC.

What do we mean when we write "senescence," "apoptosis," "necrosis," or "clearance of dying cells"?

The clearance of dying cells has become an important field of research. Apart from a significant increase in our understanding of the mechanisms for uptake, cell clearance is a basic mechanism in tissue homeostasis, cancer, resolution of inflammation, induction of tolerance, and autoimmunity. Phagocytosis of dying cells is a complex process, involving many interacting molecules on the dying cell and the phagocyte, and in the microenvironment. Although much is known on the subject, there are many questions and unknown variables that remain under investigation. Naturally, different terms were developed, among which some are misused, leading sometimes to pseudoconflicts of understanding. Several receptors were described as "phosphatidylserine receptor: are they all equal?" We will revise terms such as apoptosis, primary and secondary necrosis, lysed cells, senescent cells, clearance of apoptotic cells, efferocytosis, and more. We will try to point out misnomers, misunderstandings, and contradictions, and to define a consensual vocabulary.

Functional genomics and SNP analysis of human genes encoding proline metabolic enzymes

Proline metabolism in mammals involves two other amino acids, glutamate and ornithine, and five enzymatic activities, Delta(1)-pyrroline-5-carboxylate (P5C) reductase (P5CR), proline oxidase, P5C dehydrogenase, P5C synthase and ornithine-delta-aminotransferase (OAT). With the exception of OAT, which catalyzes a reversible reaction, the other four enzymes are unidirectional, suggesting that proline metabolism is purpose-driven, tightly regulated, and compartmentalized. In addition, this tri-amino-acid system also links with three other pivotal metabolic systems, namely the TCA cycle, urea cycle, and pentose phosphate pathway. Abnormalities in proline metabolism are relevant in several diseases: six monogenic inborn errors involving metabolism and/or transport of proline and its immediate metabolites have been described. Recent advances in the Human Genome Project, in silico database mining techniques, and research in dissecting the molecular basis of proline metabolism prompted us to utilize functional genomic approaches to analyze human genes which encode proline metabolic enzymes in the context of gene structure, regulation of gene expression, mRNA variants, protein isoforms, and single nucleotide polymorphisms.

Apolipoprotein L1, a novel Bcl-2 homology domain 3-only lipid-binding protein, induces autophagic cell death

The Bcl-2 family proteins are important regulators of type I programmed cell death apoptosis; however, their role in autophagic cell death (AuCD) or type II programmed cell death is still largely unknown. Here we report the cloning and characterization of a novel Bcl-2 homology domain 3 (BH3)-only protein, apolipoprotein L1 (apoL1), that, when overexpressed and accumulated intracellularly, induces AuCD in cells as characterized by the increasing formation of autophagic vacuoles and activating the translocation of LC3-II from the cytosol to the autophagic vacuoles. Wortmannin and 3-methyladenine, inhibitors of class III phosphatidylinostol 3-kinase and, subsequently, autophagy, blocked apoL1-induced AuCD. In addition, apoL1 failed to induce AuCD in autophagy-deficient ATG5(-/-) and ATG7(-/-) mouse embryonic fibroblast cells, suggesting that apoL1-induced cell death is indeed autophagy-dependent. Furthermore, a BH3 domain deletion construct of apoL1 failed to induce AuCD, demonstrating that apoL1 is a bona fide BH3-only pro-death protein. Moreover, we showed that apoL1 is inducible by p53 in p53-induced cell death and is a lipid-binding protein with high affinity for phosphatidic acid (PA) and cardiolipin (CL). Previously, it has been shown that PA directly interacted with mammalian target of rapamycin and positively regulated the ability of mammalian target of rapamycin to activate downstream effectors. In addition, CL has been shown to activate mitochondria-mediated apoptosis. Sequestering of PA and CL with apoL1 may alter the homeostasis between survival and death leading to AuCD. To our knowledge, this is the first BH3-only protein with lipid binding activity that, when overproduced intracellularly, induces AuCD.

Human Delta1-pyrroline-5-carboxylate synthase: function and regulation

Mammalian Delta(1)-pyrroline-5-carboxylate synthase (P5CS) is a bifunctional ATP- and NAD(P)H-dependent mitochondrial enzyme that catalyzes the coupled phosphorylation and reduction-conversion of L: -glutamate to P5C, a pivotal step in the biosynthesis of L: -proline, L: -ornithine and L: -arginine. Previously, we reported cloning and characterization of two P5CS transcript variants generated by exon sliding that encode two protein isoforms differing only by a two amino acid-insert at the N-terminus of the gamma-glutamyl kinase active site. The short form (P5CS.short) is highly expressed in the gut and is inhibited by ornithine. In contrast, the long form (P5CS.long) is expressed ubiquitously and is insensitive to ornithine. Interestingly, we found that all the established human cell lines we have studied expressed P5CS.long but not P5CS.short. In addition, expression of P5CS.long can be modulated by hormones: downregulation by hydrocortisone and dexamethasone and upregulation by estradiol, for example. Using a quantitative proteomic approach, we showed that P5CS.long is upregulated by p53 in p53-induced apoptosis in DLD-1 colorectal cancer cells. Functional genomic analysis confirmed that there are two p53-binding consensus sequences in the promoter region and in the intron 1 of the human P5CS gene. Interestingly, overexpression of P5CS by adenoviruses harboring P5CS.long or P5CS.short in various cell types has no effect on cell growth or survival. It would be of importance to further investigate the role of P5CS as a p53 downstream effector and how P5CS.short expression is regulated by hormones and factors of alternative splicing in cells isolated from model animals.