scholarly journals The Zebrafish Antiapoptotic Protein BIRC2 Promotes Edwardsiella piscicida Infection by Inhibiting Caspases and Accumulating p53 in a p53 Transcription-Dependent and -Independent Manner

2021 ◽  
Vol 12 ◽  
Author(s):  
Lu Cao ◽  
Dong Yan ◽  
Jun Xiao ◽  
Hao Feng ◽  
Ming Xian Chang
Keyword(s):  
Biological Activities ◽  
P53 Protein ◽  
Larval Survival ◽  
Negative Regulator ◽  
Independent Manner ◽  
P53 Expression ◽  
Antiapoptotic Protein ◽  
Zebrafish Larvae ◽  
Infection Treatment ◽  
Edwardsiella Piscicida

IAPs (inhibitors of apoptosis) are endogenous caspase inhibitors with multiple biological activities. In the present study, we show functional characteristics of antiapoptotic protein BIRC2 (cIAP1) in response to Edwardsiella piscicida infection. Overexpression of BIRC2 in zebrafish larvae promoted the proliferation of E. piscicida, leading to a decreased larvae survival. The expression levels of caspases including casp3, casp8, and casp9 were significantly inhibited by BIRC2 overexpression in the case of E. piscicida infection. Treatment of zebrafish larvae microinjected with BIRC2 with the caspase activator PAC-1 completely blocked the negative regulation of BIRC2 on the E. piscicida infection, with the reduced inhibition on the casp3 and without inhibition on casp8 and casp9. In contrast to the regulation of BIRC2 on the caspases, BIRC2 overexpression significantly induced the expression of p53, especially at 24 hpi. In addition to the cytoplasmic p53 expression, BIRC2 overexpression also induced the expression of the nuclear p53 protein. Further analysis demonstrated that BIRC2 could interact and colocalize with p53 in the cytoplasm. The numbers of E. piscicida in larvae overexpressed with BIRC2 and treated with pifithrin-μ (an inhibitor of mitochondrial p53) or pifithrin-α (an inhibitor of p53 transactivation) were lower than those of larvae without pifithrin-μ or pifithrin-α treatment. Critically, the p53 inactivators pifithrin-μ and pifithrin-α had no significant effect on larval survival, but completely rescued larval survival for zebrafish microinjected with BIRC2 in the case of E. piscicida infection. Collectively, the present study suggest that piscine BIRC2 is a negative regulator for antibacterial immune response in response to the E. piscicida infection via inhibiting caspases, and accumulating p53 in a p53 transcription-dependent and -independent manner.

UV Induces GADD45 in a p53-Dependent and -Independent Manner in Human Keratinocytes

2003 ◽  
Vol 7 (2) ◽  
pp. 119-123 ◽  
Author(s):  
Tomoko Maeda ◽  
Adrian B. Sim ◽  
Duane A. Leedel ◽  
Prescillia P. S. Chua ◽  
Eugene G. Chomey ◽  
...  
Keyword(s):  
Dna Repair ◽  
P53 Protein ◽  
Human Keratinocytes ◽  
Cell Cycle Checkpoint ◽  
Checkpoint Control ◽  
Independent Manner ◽  
Rnase Protection ◽  
P53 Expression ◽  
Multifunctional Protein ◽  
Rna Protection

Background: GADD45 is a multifunctional protein involved in DNA repair and in cell cycle checkpoint control. p53 plays an important role in regulating DNA repair and in response to UVB in keratinocytes. Objective: GADD45 and p53 expression was examined and compared at the mRNA and protein level after exposure to UV irradiation. Methods: Human keratinocytes were exposed to increasing doses of UVB, and an RNA protection assay and a Western blot analysis were performed. Results: The RNase protection assays using human keratinocytes showed that GADD45 mRNA increases after 4 h and remains elevated for 24 h in cells irradiated at 100, 300, or 600 J/m2 UVB. The level of GADD45 protein increases after 8 h and remains elevated for 48 h, with maximal induction at 300 J/m2. p53 mRNA did not rise in concert with GADD45 at any dose used, and p53 protein was not up-regulated at the lower dose of 100 J/m2. Conclusion: GADD45 is regulated in both a p53-dependent and a p53-independent manner in keratinocytes after UV exposure.

scholarly journals Prolyl hydroxylase 3 stabilizes the p53 tumor suppressor by inhibiting the p53–MDM2 interaction in a hydroxylase-independent manner

2019 ◽  
Vol 294 (25) ◽  
pp. 9949-9958 ◽  
Author(s):  
Yiming Xu ◽  
Qiang Gao ◽  
Yaqian Xue ◽  
Xiuxiu Li ◽  
Liang Xu ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Tumor Suppressor ◽  
P53 Protein ◽  
Prolyl Hydroxylase ◽  
Hydroxylase Activity ◽  
Independent Manner ◽  
P53 Expression ◽  
Genetic Ablation ◽  
Protein Levels

Prolyl hydroxylase 3 (PHD3) has initially been reported to hydroxylase hypoxia-inducible factor α (HIFα) and mediate HIFα degradation. More recent studies have shown that, in addition to HIFα, PHD3 has also other substrates. Moreover, pHD3 is believed to act as a tumor suppressor, but the underlying mechanism remains to be elucidated. Here, we demonstrate that PHD3 stabilizes p53 in a hydroxylase-independent manner. We found that PHD3 overexpression increases and PHD3 knockdown decreases p53 levels. Mechanistically, PHD3 bound MDM2 proto-oncogene (MDM2) and prevented MDM2 from interacting with p53, thereby inhibiting MDM2-mediated p53 degradation. Interestingly, we found that PHD3 overexpression could enhance p53 in the presence of the prolyl hydroxylase inhibitor dimethyloxalylglycine, and the prolyl hydroxylase activity-deficient variant PHD3-H196A also inhibited the p53-MDM2 interaction and stabilized p53. Genetic ablation of PHD3 decreased p53 protein levels in mice intestinal epithelial cells, but a genetic knockin of PHD3-H196A did not affect p53 protein levels in vivo. These results suggest that the prolyl hydroxylase activity of PHD3 is dispensable for its ability to stabilize p53. We found that both PHD3 and PHD3-H196A suppress the expression of the stem cell-associated gene NANOG and inhibited the properties of colon cancer stem cells through p53. Our results reveal an additional critical mechanism underlying the regulation of p53 expression and highlight that PHD3 plays a role in the suppression of colon cancer cell stemness in a hydroxylase-independent manner.

Enhanced Cytotoxicity in Chronic Myeloid Leukemia Primitive Progenitors by the Combined Action of Imatinib and An HDM2-Inhibitor

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3213-3213
Author(s):  
Luke F Peterson ◽  
Shaomeng Wang ◽  
Moshe Talpaz
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Cell Line ◽  
Myeloid Leukemia ◽  
Cytotoxic Effect ◽  
P53 Protein ◽  
Single Agent ◽  
Negative Regulator ◽  
Hematopoietic Stem ◽  
P53 Expression ◽  
Cd34 Cells

Abstract In Chronic Myeloid Leukemia (CML) the 9;22 chromosomal translocation and corresponding BCR-ABL protein are present in the most primitive hematopoietic stem/progenitors (Lin−/CD38−/CD34+). These cells are refractory to the effect of BCR-ABL tyrosine kinase inhibitors. The mechanism of this resistance has not been fully elucidated but is clearly distinct from the mechanism of resistance in the more mature CML cells. The p53 gene is rarely mutated in the chronic phase of CML. BCR-ABL is able to positively affect p53 expression whose potential proapoptotic effect may be balanced by survival signals such as Bcl-XL and Stat signaling. However, BCR-ABL also positively regulates HDM2, the negative regulator of p53, which may be the alternative mechanism of counteracting the induced p53. In an effort to facilitate a cytotoxic effect directed against the refractory CML primitive stem/progenitor cells we elected to explore the role of stabilizing the p53 protein. Accordingly we tested a novel inhibitor of the HDM2-p53 interaction (MI-219; Ascenta), which interferes with unmutated p53 degradation. MI- 219 induced reproducible cytotoxicity in four CML blast-crisis cell lines with intact p53 (WDT2, WDT3, BV173 and BV173R) with an IC50 ~2 microM. The BV173R cell line which has the Imatinib resistant T315I mutation displayed a cytotoxic effect with the MI- 219 equal to its parental BV173 cell line (IC50 ~2 microM). Responses were associated with the induction of p53 protein, its targets p21WAF1 and PUMA, and cleavage of PARP. The K562 cell line with mutated p53 did not respond to MI-219 as expected. MI-219 had a modest cytotoxic effect on magnetically separated (MACS) CD34+ cells from CML patients as a single agent (range of 30–50% cell death at 5 microM MI-219). Nevertheless, MI-219 markedly enhanced the cytotoxic effect of Imatinib on CD34+ cells, while as a single agent Imatinib induced 15–30% apoptosis. However the combination of 2 microM Imatinib and 5 microM MI-219 led to a cytotoxic effect averaging 76.4 ± 10.6% apoptosis. This enhanced cytotoxic effect was further noted in flow cytometrically sorted progenitor (Lin−/CD38+/CD34+) populations (~86.7% apoptosis). This combination equally induced apoptosis in primitive progenitor/stem cells (Lin−/CD38−/CD34+; ~83.0%), despite the minimal affect of each agent when given alone (Imatinib, ~20.8 % apoptosis; MI-219, ~36.9% apoptosis). This cytotoxic effect in primary CML cells was again associated with the induction of p53, p21WAF1, and the cleavage of PARP. Here we demonstrate that an increased level of p53 bypasses T315I associated resistance to Imatinib, and in combination with Imatinib generates a substantial cytotoxic effect in early progenitors, which are otherwise refractory to the effect of either agent alone. Thus these observations propose that the combination of MI-219 an HDM2-inhibitor with Imatinib may facilitate the eradication of minimal residual disease present within the primitive Lin−/CD38−/CD34+ population of CML.

scholarly journals Mutated p53 in HGSC—From a Common Mutation to a Target for Therapy

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3465
Author(s):  
Aya Saleh ◽  
Ruth Perets
Keyword(s):  
Cancer Progression ◽  
Target Genes ◽  
P53 Protein ◽  
Genetic Alterations ◽  
Common Mutation ◽  
Missense Mutations ◽  
P53 Expression ◽  
Histologic Subtype ◽  
Tp53 Mutations

Mutations in tumor suppressor gene TP53, encoding for the p53 protein, are the most ubiquitous genetic variation in human ovarian HGSC, the most prevalent and lethal histologic subtype of epithelial ovarian cancer (EOC). The majority of TP53 mutations are missense mutations, leading to loss of tumor suppressive function of p53 and gain of new oncogenic functions. This review presents the clinical relevance of TP53 mutations in HGSC, elaborating on several recently identified upstream regulators of mutant p53 that control its expression and downstream target genes that mediate its roles in the disease. TP53 mutations are the earliest genetic alterations during HGSC pathogenesis, and we summarize current information related to p53 function in the pathogenesis of HGSC. The role of p53 is cell autonomous, and in the interaction between cancer cells and its microenvironment. We discuss the reduction in p53 expression levels in tumor associated fibroblasts that promotes cancer progression, and the role of mutated p53 in the interaction between the tumor and its microenvironment. Lastly, we discuss the potential of TP53 mutations to serve as diagnostic biomarkers and detail some more advanced efforts to use mutated p53 as a therapeutic target in HGSC.

Immunohistochemical study of p53 expression in endometrial carcinomas: correlation with markers of proliferating cells and clinicopathologic features

1993 ◽  
Vol 3 (6) ◽  
pp. 363-368 ◽  
Author(s):  
T. Hachisuga ◽  
K. Fukuda ◽  
M. Uchiyama ◽  
N. Matsuo ◽  
T. Iwasaka ◽  
...  
Keyword(s):  
Dna Polymerase ◽  
Proliferative Activity ◽  
P53 Protein ◽  
Myometrial Invasion ◽  
Proliferating Cells ◽  
Ki 67 ◽  
Normal Endometrium ◽  
P53 Expression ◽  
Dna Polymerase Α ◽  
Endometrial Carcinomas

Using anti-p53 (PAb1801 and PAb240), anti-DNA polymerase α and Ki-67 monoclonal antibodies, the expression of p53 was studied in 11 normal endometria, 14 endometrial hyperplasias and 27 endometrial carcinomas and its relationship to the proliferative activity of the tumors was examined. Normal endometria and simple hyperplasias were completely negative for p53. The PAb1801 indices of complex hyperplasias and complex atypical hyperplasias were 2.5±1.8% and 5.0±3.2%, respectively. The PAb1801 indices of grade 1, grade 2 and grade 3 endometrial carcinomas were 10.2±14.2%, 44.4±29/0% and 45.0±32.5%, respectively. These results indicate a progressively enhanced p53 expression in the sequence from normal endometrium, through hyperplasia to carcinoma. A significant correlation between p53 expression and labeling indices of Ki-67 and DNA polymerase α was observed in endometrial carcinomas. The endo-metrial carcinomas with p53 overexpression developed mainly in post-menopausal patients and were frequently high-grade tumors with deep myometrial invasion. These findings may indicate that overexpression of p53 protein contributes to the proliferative activity of the tumor cells.

Esophageal Small Cell Carcinomas

2000 ◽  
Vol 124 (2) ◽  
pp. 228-233 ◽  
Author(s):  
King Y. Lam ◽  
Simon Law ◽  
Peter H. M. Tung ◽  
John Wong
Keyword(s):  
Cell Carcinoma ◽  
Small Cell Carcinoma ◽  
Survival Data ◽  
Malignant Tumors ◽  
P53 Protein ◽  
Small Cell ◽  
Immunohistochemical Method ◽  
Clinicopathologic Features ◽  
P53 Expression ◽  
Mib 1

Abstract Objective.—To evaluate the clinicopathologic features and the roles of p53 and MIB-1 in esophageal small cell carcinoma. Method.—Twenty patients (14 men and 6 women) with esophageal small cell carcinoma treated in our hospital from 1982 through 1996 were studied. The clinicopathologic features, treatment received, and survival data of these patients were documented. Representative tissue was collected from each tumor, and immunohistochemical preparations for p53 protein and MIB-1 were made. Results.—Small cell carcinoma accounted for 1.3% of all esophageal malignant tumors. The median age of patients at presentation was 60 years. On gross examination, the tumors were large ulcerative lesions (median length, 7.5 cm). In 17 patients in whom p53 immunohistochemical study was performed, p53 protein was detected in 65% (9 of 17). All stage IV tumors were negative for p53 expression. The median tumor cell MIB-1 score was high at 855 (range, 810–964) positive cells per 1000. Overall median survival was 3.4 months. In patients who underwent chemotherapy, there was significant response. Conclusions.—Esophageal small cell carcinoma is an aggressive tumor. Overexpression of p53 is associated with early stages of carcinogenesis. The high proliferative index, as defined by the MIB-1 immunohistochemical method, may be related to aggressive behavior and high sensitivity to chemotherapy and radiotherapy.

scholarly journals p53 immunohistochemical staining patterns in oral squamous cell carcinoma

2016 ◽  
Vol 6 (12) ◽  
pp. 1013-1017
Author(s):  
G Dundy ◽  
H Kumar ◽  
A Singh ◽  
A Chandarakant
Keyword(s):  
Squamous Cell Carcinoma ◽  
Oral Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Oral Mucosa ◽  
Squamous Cell ◽  
P53 Protein ◽  
P Value ◽  
P53 Expression ◽  
Normal Oral Mucosa ◽  
Significant Difference

Background: Mutation of p53 gene is one of the most common events in oral carcinogenesis. Accumulation of p53 protein has also been detected in premalignant lesions.Materials and Methods:  This study included 40 biopsy samples, which were received in department of pathology, Sarojini Naidu Medical College, Agra, to ascertain p53 expression by immunohistochemically, in patients with oral squamous cell carcinomas and to correlate its expression with histological grade, different sites in oral cavity and tobacco intake/smoking habits.Results: Out of 40 biopsies of oral mucosa, 03 showed normal oral mucosa and 37 were diagnosed as squamous cell carcinoma (SCC), most patients were in 5th and 6th decade and majority (86.5%) of oral SCC were males with buccal mucosa being the most common site. There was a statistically significant difference in p53 expression between oral SCC and normal oral mucosa (p value <0.05). Of total 37 cases, 12 cases were well differentiated type, 16 moderately differentiated and 09 of poorly differentiated type of SCC. In each category, about two thirds were positive for p53 staining. Out of total 37 cases of oral SCC, 64.9% were positive and 35.1% were negative for p53 expression, 34 cases had positive history of tobacco intake/smoking habits, of which 23 cases were positive while 11 cases were negative for p53 staining.Conclusion: Abnormal p53 protein was detected in 64.9% of oral squamous cell carcinoma, but not in normal oral mucosa. p53 expression was associated with malignant transformation of oral mucosa. 

scholarly journals Impact of p53 modulation on interactions between p53 family members during HaCaT keratinocytes differentiation

2020 ◽  
Author(s):  
AL Rusanov ◽  
PM Kozhin ◽  
DD Romashin ◽  
MN Karagyaur ◽  
NG Luzgina
Keyword(s):  
Cell Line ◽  
P53 Protein ◽  
Tp53 Gene ◽  
Negative Regulator ◽  
Elevated Concentration ◽  
Hacat Cells ◽  
Differentiation Markers ◽  
Substantial Impact ◽  
Skin Physiology

HaCaT cell line is a widely used model for studying normal human keratinocytes. However, mutations of TP53 gene are typical for this cell line, which have a substantial impact on functions of the encoded protein. The features of this regulatory circuit should be considered when using HaСaT cells for assessment of human skin physiology and pathology in vitro. The study was aimed to assess the features of differentiation realization in HaCaT cells with modulated activity of p53 protein. The expression of p53 was reduced by knockdown of TP53 gene by shRNA (by 2.2 times, p < 0.05), and the elevated concentration of the p53 active forms was achieved via exposure of cells to Nutlin-3a, the MDM2 inhibitor and the major negative regulator of p53. It has been found that regulation of at least three differentiation markers, СASP14, IVL (expression increase by 3.9 and 3.7 times respectively in the p53-knockdown cells, p < 0.05) and TGM1 (twofold expression decrease in the p53-knockdown cells, and 1.7-fold expression increase under exposure to Nutlin-3a, p < 0.05) in HaCaT cells is p53-mediated. The positive correlation has been revealed for expression of TGM1 and p53 that might be realized indirectly via ΔNp63 expression alteration. At the same time, modulation of p53 does not result in significant alterations in expression of cytokeratins.

scholarly journals Selective inactivation of USP18 isopeptidase activity in vivo enhances ISG15 conjugation and viral resistance

2015 ◽  
Vol 112 (5) ◽  
pp. 1577-1582 ◽  
Author(s):  
Lars Ketscher ◽  
Ronny Hannß ◽  
David J. Morales ◽  
Anja Basters ◽  
Susana Guerra ◽  
...  
Keyword(s):  
Protease Activity ◽  
Protein Modification ◽  
Negative Regulator ◽  
Viral Resistance ◽  
Regulatory Function ◽  
Influenza B Virus ◽  
Influenza B ◽  
Minimal Risk ◽  
Independent Manner

Protein modification by the ubiquitin-like protein ISG15 is an interferon (IFN) effector system, which plays a major role in antiviral defense. ISG15 modification is counteracted by the isopeptidase USP18, a major negative regulator of IFN signaling, which was also shown to exert its regulatory function in an isopeptidase-independent manner. To dissect enzymatic and nonenzymatic functions of USP18 in vivo, we generated knock-in mice (USP18C61A/C61A) expressing enzymatically inactive USP18. USP18C61A/C61A mice displayed increased levels of ISG15 conjugates, validating that USP18 is a major ISG15 isopeptidase in vivo. Unlike USP18−/− mice, USP18C61A/C61A animals did not exhibit morphological abnormalities, fatal IFN hypersensitivity, or increased lethality, clearly showing that major USP18 functions are unrelated to its protease activity. Strikingly, elevated ISGylation in USP18C61A/C61A mice was accompanied by increased viral resistance against vaccinia virus and influenza B virus infections. Enhanced resistance upon influenza B infection in USP18C61A/C61A mice was completely reversed in USP18C61A/C61A mice, which additionally lack ISG15, providing evidence that the observed reduction in viral titers is ISG15 dependent. These results suggest that increasing ISGylation by specific inhibition of USP18 protease activity could constitute a promising antiviral strategy with only a minimal risk of severe adverse effects.

Analysis of p53 expression in human tumours: an antibody raised against human p53 expressed in Escherichia coli

1992 ◽  
Vol 101 (1) ◽  
pp. 183-189 ◽  
Author(s):  
C.A. Midgley ◽  
C.J. Fisher ◽  
J. Bartek ◽  
B. Vojtesek ◽  
D. Lane ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Polyclonal Antibodies ◽  
P53 Protein ◽  
Expression System ◽  
High Titre ◽  
T7 Promoter ◽  
Aberrant Expression ◽  
P53 Expression ◽  
Normal Human ◽  
Very High

A cDNA encoding the complete normal human p53 protein was expressed in Escherichia coli using an expression system based on the bacteriophage T7 promoter. The cDNA was adapted so that the full-length protein was produced without fusion to any other sequence. Large amounts of the protein were isolated and the purified protein used to produce very high titre polyclonal antibodies to p53. These new antibodies permit the sensitive detection of p53 and p53 complexes in ELISA and immunoblotting assays. Most importantly, they also permit the detection of p53 in archival tumour material that has been conventionally fixed in formalin and embedded in paraffin wax. Using this reagent we have found that aberrant expression of p53 is a frequent feature of human breast cancer. We are able to recognise six different classes of p53 expression pattern that may be of help in the subclassification of breast tumours.

Sign in / Sign up

Export Citation Format

Share Document