P53 Overexpression Research Articles

Abstract 4136204: Clearing Senescent Cells Improves Mouse Survival Rate Post Myocardial Infarction through Alteration of Cardiomyocyte and Immune Cell Subpopulations

Introduction: Cellular senescence often involves a p16-pathway, and p16 overexpression is a hallmark of senescent cells. The role of cellular senescence in myocardial infarction (MI) and any mediating mechanisms remain unclear. Aims: To investigate the effect of p16 + cell clearance on survival post MI and elucidate underlying mechanisms. Methods: We utilized INK-ATTAC transgenic mice, in which p16 + cells undergo targeted apoptosis upon exposure to AP20187 (AP). Sham and MI mice were treated with AP or vehicle (V) twice-weekly for one month, starting 3-4 hours post-MI. Survival rate improvement post MI in the AP group (Fig A, P<0.001) prompted us to evaluate effects of senescent cell clearance at the cardiac cellular level and its involvement in MI-associated pathways at 3 days post-MI. The infarct and peri-infarct areas were collected and snap-frozen. Nuclei were extracted with modified gentleMACS methods; libraries were constructed using 10X Genomics. Standard software (CellRanger, Seurat) were employed for single-nuclei-RNA-seq data analysis. Results: Cardiomyocytes (CMs) showed 5 distinct subsets. CM subclusters 1 and 2 showed enrichments of genes characteristic of infarct boarder zones, while most sham CMs were found in subcluster 0, reflecting healthy-CMs. AP-treated mice exhibited a higher proportion of healthy CMs (Fig B). Differentially expressed genes (DEGs) between V and AP group were enriched in the healthy CMs, suggesting that clearance of p16 + cells improves the status of CMs post MI (Fig C). Immune-cell profiling showed that by far the largest number of DEG for AP vs vehicle were expressed in the (arginase-1) Arg1 macrophage subgroup (Fig D). The percentage of Arg1 macrophages decreased in the AP group (FDR=0.059) (Fig E). We noted significant enrichment in the hypoxia and cardiac rupture pathways in Arg1 macrophages (Fig F), correlating with the high death rate from myocardial rupture in V-mice. Conclusion: These results suggest a significant role of p16 + senescent cells in post-MI mortality, potentially through effects on cardiomyocytes and a specific macrophage subpopulation, Arg1 macrophages.

Surrogate immunohistochemistry markers in adult gliomas – Experience in a tertiary care hospital

Objectives: The recent World Health Organization classification has recommended the usage of surrogate immunohistochemical markers for molecular classification of gliomas. However, only a few studies have attempted to study the expression of the entire panel of markers. The current study was undertaken to study the association of recognized surrogate immunohistochemical markers (isocitrate dehydrogenase 1 [IDH-1], alpha-thalassemia mental retardation X-linked [ATRX] and p53) in different histological lineages and grades of adult gliomas. Materials and Methods: This study was conducted on 118 cases of adult gliomas diagnosed on histopathology over a 2-year duration in a tertiary care hospital. The expression of surrogate immunohistochemistry markers (IDH-1, ATRX, and p53) in these cases was studied. Statistical analysis: Descriptive statistical analysis with the Statistical Package for the Social Science system version 17.0. Results: The frequency of IDH-1 positivity was significantly higher in oligodendrogliomas (OG: 76.5%; oligoastrocytoma: 100%) versus astrocytoma (AS) (grades 2 and 3: 48.1%). It was also significantly higher in diffuse gliomas (grades 2 and 3) versus glioblastomas (64% vs. 16.9%). Among IDH-mutant diffuse gliomas, ATRX loss was significantly higher in AS versus OGs (84.6% vs. 7.7%). P53 overexpression correlated significantly with histological subtype (AS 2,3: 55.6% vs. OG: 5.9%). Conclusions: The surrogate immunohistochemical panel of IDH-1, ATRX, and p53 showed significant association with distinct histopathological subtypes and is helpful in molecular stratification. Cut-offs of ≥ 10% nuclear positivity for p53 and 50% loss of nuclear ATRX expression showed a good correlation.

Study of Molecular Markers in Glioma and Their Association with Clinicopathological Features.

Central nervous system tumors are a major cause of morbidity and mortality worldwide. The most prevalent type of primary brain tumor is glioma. The exploration of significant genetic, epigenetic, and transcriptional abnormalities has not only improved our understanding of glioma pathogenesis but has also revealed that these molecular alterations can serve as useful diagnostic markers for more precise classification and are linked to better treatment response and prognosis. Hence, incorporating molecular markers into routine tumor classification is a major priority in modern glioma diagnostics. The aim is to assess the mutation status of isocitrate dehydrogenase (IDH)-1, alpha-thalassemia/mental retardation syndrome X-linked (ATRX), and tumor protein 53 in glioma, and look for their association with various clinicopathological features. A single-center prospective cohort study, where all biopsies of glioma (January 2019 to July 2020) were evaluated, and immunohistochemistry was performed to assess the expression of IDH-1, ATRX, p53, and Ki-67 index. The data were analyzed using IBM SPSS-24 software. Immunohistochemistry was performed in 123 consecutive cases of glioma. IDH-1 mutation was noted in 54 (43.9%) cases and these patients frequently presented with "seizures" (P = 0.006). The expression was maximum in World Health Organization (WHO) grade 2 tumors (65.4%) (P < 0.001), with the highest frequency in oligodendrogliomas (100% in WHO grade 2 and 3). Furthermore, these tumors showed lower proliferative indices (P = 0.001). ATRX mutation was noted in 59 (48%) and p53 overexpression was noted in 76 (61.8%) cases. These mutations were significantly associated with astrocytic phenotype (P = 0.03). Molecular characterization of glioma is an important step in modern glioma diagnostics and immunohistochemistry can play an important role. IDH-1 mutation is commonly observed in adults, frontal lobe location, patients presenting with seizures, and WHO grade 2 tumors with the highest frequencies in oligodendrogliomas. ATRX and p53 can be used as surrogate markers for tumors of astrocytic lineage.

TMEM206 Contributes to Cancer Hallmark Functions in Colorectal Cancer Cells and Is Regulated by p53 in a p21-Dependent Manner

Acid-induced ion flux plays a role in pathologies where tissue acidification is prevalent, including cancer. In 2019, TMEM206 was identified as the molecular component of acid-induced chloride flux. Localizing to the plasma membrane, TMEM206 contributes to cellular processes like acid-induced cell death. Since over 50% of human cancers carry loss of function mutations in the p53 gene, we aimed to analyze how TMEM206 is regulated by p53 and its role in cancer hallmark function and acid-induced cell death in HCT116 colorectal cancer (CRC) cells. We generated p53-deficient HCT116 cells and assessed TMEM206-mediated Cl− currents and transcriptional regulation using the patch-clamp and a dual-luciferase reporter assay, respectively. To investigate the contribution of TMEM206 to cancer hallmark functions, we performed migration and metabolic activity assays. The role of TMEM206 in p53-mediated acid-induced cell death was assessed with cell death assays. The TMEM206 mRNA level was significantly elevated in human primary CRC tumors. TMEM206 knockout increased acid-induced cell death and reduced proliferation and migration, indicating a role for TMEM206 in these cancer hallmark functions. Furthermore, we observed increased TMEM206 mRNA levels and currents in HCT116 p53 knockout cells. This phenotype can be rescued by transient overexpression of p53 but not by overexpression of dysfunctional p53. In addition, our data suggest that TMEM206 may mediate cancer hallmark functions within p53-associated pathways. TMEM206 promoter activity is not altered by p53 overexpression. Conversely, knockout of p21, a major target gene of p53, increased TMEM206-mediated currents, suggesting expression control of TMEM206 by p21 downstream signaling. Our results show that in colorectal cancer cells, TMEM206 expression is elevated, contributes to cancer hallmark functions, and its regulation is dependent on p53 through a p21-dependent mechanism.

Assessment of P16 and Ki-67 Proteins Immunoexpressing in Oral Mucosa Among Saudi Smokers.

It is widely known that tobacco use significantly contributes to a variety of health problems, including mouth cancer. The proteins P16 and Ki-67 have a role in regulating the cell cycle and promoting cell growth. Analyzing the levels of these proteins can give us valuable information about the overall health of cells. This study aims to assess the cellular alterations and immunohistochemical expression of P16 and Ki-67 in the oral mucosa of Saudi smokers. From March to December 2023, a cross-sectional study scraped 500 samples from the buccal mucosa. Participants in the study were Saudi citizens of both genders. We selected a total of 300 individuals who smoked cigarettes and 200 individuals who did not smoke tobacco as the control group. The selection process involved two sample techniques: initially purposive sampling and subsequently snowball sampling. The samples underwent an immunohistochemical examination to determine the presence of P16 and Ki-67 protein overexpression. We evaluated the samples by assessing the proportion of cells that exhibited positive staining and the intensity of the staining. The data were examined utilizing SPSS. We identified categorical variables by calculating frequencies and percentages using the chi-squared test. A significance level of p < 0.05 was used to determine statistical significance. A total of 48% of cigarette users had abnormal results, compared to 20% of nonsmokers. These abnormalities included cytological atypia, inflammation, reverse cytological infection, and binucleated or multinucleated cells (p = 0.015). People who smoked had higher levels of P16 and Ki-67 expressions than people who did not smoke, 12% and 5%, respectively (p = 0.042). There were no important changes in P16/Ki-67 expression between participants of different ages (p = 0.68) or between men and women (p = 0.27). These results demonstrate the detrimental effects of smoking on cell health, underscoring the importance of quitting to reduce the risk of cytological abnormalities and related diseases. Smokers have higher levels of the proteins P16 and Ki-67, which shows how important these biomarkers are for understanding the risks to oral health.

TAF15 inhibits p53 nucleus translocation and promotes HCC cell 5-FU resistance via post-transcriptional regulation of UBE2N.

Chemotherapy resistance is an important factor responsible for the low 5-year survival rate of hepatocellular carcinoma (HCC) patients. Ubiquitin-conjugating enzyme E2N (UBE2N) is a cancer-associated ubiquitin-conjugating enzyme that is expressed in HCC tissues, and its high expression is associated with a poor prognosis. This study explored the role played by UBE2N in development of 5-fluorouracil (5-FU) resistance in HCC cells. Three HCC cell lines (HepG2 [p53 wild type], Huh7 [p53 point mutant type], Hep3B [p53 non-expression type]), and one normal liver cell line (MIHA) were used in our present study. The IC50 value of 5-FU was determined using a cell counting kit-8 (CCK-8) assay. Cell viability was assessed by colony formation assays. TUNEL assays and flow cytometry were used to analyze cell apoptosis. RNA pull-down and RNA immunoprecipitation (RIP) assays were performed to confirm the binding relationship between UBE2N mRNA and TAF15 protein. Our results showed that TAF15 and UBE2N were highly expressed in HCC cells. UBE2N inhibited the translocation of p53 protein into the cell nucleus to increase 5-FU resistance, as reflected by an increased IC50 value, an increase in cell viability, and a reduction in cell apoptosis. Overexpression of p53 reduced 5-FU resistance, but that effect could be reversed by UBE2N overexpression. TAF15 protein bound to and stabilized UBE2N mRNA, thereby inhibiting p53 translocation into the nucleus and promoting 5-FU resistance in HCC cells. Collectively, our present study identified a novel mechanism by which TAF15/UBE2N regulates p53 distribution to increase 5-FU resistance. Our results also suggest potential therapeutic strategies for treating HCC.

Metformin restores autophagic flux and mitochondrial function in late passage myoblast to impede age-related muscle loss

Sarcopenia, which refers to age-related muscle loss, presents a significant challenge for the aging population. Age-related changes that contribute to sarcopenia include cellular senescence, decreased muscle stem cell number and regenerative capacity, impaired autophagy, and mitochondrial dysfunction. Metformin, an anti-diabetic agent, activates AMP-activated protein kinase (AMPK) and affects various cellular processes in addition to reducing hepatic gluconeogenesis, lowering blood glucose levels, and improving insulin resistance. However, its effect on skeletal muscle cells remains unclear. This study aimed to investigate the effects of metformin on age-related muscle loss using a late passage C2C12 cell model. The results demonstrated that metformin alleviated hallmarks of cellular senescence, including SA-β-gal activity and p21 overexpression. Moreover, treatment with pharmacological concentrations of metformin restored the reduced differentiation capacity in late passage cells, evident through increased myotube formation ability and enhanced expression of myogenic differentiation markers such as MyoD, MyoG, and MHC. These effects of metformin were attributed to enhanced autophagic activity, normalization of mitochondrial membrane potential, and improved mitochondrial respiratory capacity. These results suggest that pharmacological concentrations of metformin alleviate the hallmarks of cellular senescence, restore differentiation capacity, and improve autophagic flux and mitochondrial function. These findings support the potential use of metformin for the treatment of sarcopenia.

Computational Development of New Inhibitors for Apoptosis Stimulating Protein of p53 (iASPP) Using Pharmacophore Modeling, Docking, and MD Simulation Approaches

Inhibitor of apoptosis-stimulating protein of p53 (iASPP) overexpression is associated with diverse human tumors, including lung cancer, colorectal cancer, prostate cancer, acute leukemia, hepatocellular carcinoma, cervical cancer, and ovarian cancer. This study aims to find new and potent inhibitors for the iASPP drug target. Using pharmacophore-based virtual screening, molecular docking, and molecular dynamics simulation an integrated strategy was developed to find highly effective iASPP inhibitors. Subsequently, the pharmacophore model was employed as a screening query to find promising inhibitors from the ZINC database. Total 36/12000 hits were identified against the iASPP drug target. The binding mode of the promising identified inhibitors was predicted by a molecular docking study. To evaluate the stability of the newly identified inhibitors top 03 best docking scores compounds were subjected to MD simulation. MD simulation and binding energy calculation confirmed that the compounds including ZINC001361049159, ZINC001361124195, and ZINC001545869876 were stable. The MD simulation analysis indicated that among all the compounds ZINC001361049159 was the most potent. These newly designed iASPP inhibitors could be used as starting material to identify new and potent anti-cancer drugs.

The combination of p16 and Rb expression pattern is helpful to predict high-risk HPV infection and the primary site in lymph node metastases of squamous cell carcinoma

Identifying the primary site of metastatic squamous cell carcinoma in lymph nodes can be challenging. An immunohistochemistry (IHC) analysis recently revealed that high-risk human papillomavirus (HR-HPV)-associated oropharyngeal squamous cell carcinomas (OPSCCs) typically show overexpression of p16 protein and a partial loss pattern of Rb. Nevertheless, the status of these markers in metastatic lesions is still unclear. In this study, we examined p16 and Rb expression status by IHC and transcriptionally active HR-HPV infection by mRNA in situ hybridization in paired primary and metastatic SCC lesions. A total of 50 patients with OPSCCs (n=17), hypopharyngeal SCCs (n=16), laryngeal SCCs (n=6), or uterine cervical SCCs (n=11) were enrolled. HR-HPV and p16 were positive in 21/50 (42 %) and 23/50 (46 %) patients, respectively. Primary and metastatic lesions showed concordant results for those three markers in individual patients. Among the p16-positive patients (n=23), HPV-positive cases typically showed a partial loss of Rb (n=20) and, rarely, a complete loss of Rb (n=1), whereas HPV-negative cases showed preserved Rb expression (n=2). All 27 p16-negative cases lacked HPV infection, while preserved expression and complete loss of Rb were observed in 26 and 1 of the p16-negative cases, respectively. Compared to standalone p16, the combination of p16 overexpression and Rb-partial/complete loss showed equally excellent sensitivity and negative predictive value (each 100 %) as well as improved specificity (100 % versus 93.1 %) and positive predictive value (100 % versus 91.3 %). Our results suggest that combining p16 and Rb expression patterns may be helpful in screening for HR-HPV infection in metastatic lymph nodes and in estimating the primary site of SCC.

Sphingosine Kinase 2 Controls the Aggressive Phenotype of Oral Squamous Cell Carcinoma by Regulating miR-205 and miR-296 through p53

Alterations in microRNAs, p53, and sphingolipid metabolism have been associated with head and neck squamous cell carcinoma (HNSCC). However, sphingosine kinase 2, a critical enzyme in sphingolipid metabolism, is poorly understood in HNSCC. Our aim was to investigate how SK2 and p53 interact to regulate miR-205 and miR-296. Analysis of small-RNA-seq data from non-tumor oral keratinocytes with SK2 overexpression (NOK-SK2) compared to NOK-control (NOK- Ø) revealed differential expression of more than 100 miRNAs being half regulated by p53. The expression of miR-205 was downregulated, and miR-296 was upregulated in NOK-SK2 cells; however, cells with SK2 knockdown and p53 overexpression showed an opposite profile. Proteins involved in miRNA biogenesis were increased in NOK-SK2 cells while their levels were decreased in NOK-SK2 cells with p53 overexpression. miR-205 mimic and miR-296 inhibitor decreased the aggressiveness and cancer stem-like cells in oral keratinocytes and oral carcinoma cells with SK2 deregulation. Overexpression of miR-205 in HN12-SK2 cells decreased tumor formation capacity and NOK-SK2 cells abrogated the tumor growth in mice. Our results indicate crosstalk between SK2 and p53 in regulating miR-205 and miR-296, which could be potential targets for HNSCC therapy.

Gastric-type extremely well-differentiated adenocarcinoma of the stomach: A rare tumor with diagnostic difficulties and high inter-observer variation in endoscopic pinch biopsies

Extremely well-differentiated gastric-type adenocarcinoma (EWDGA) is a rare type of gastric cancer composed of deceptively bland-looking malignant cells resembling normal foveolar or pyloric epithelium. The histological features of this tumor have not been recognized by many pathologists, and inter-observer variation studies are lacking. Here, we report seven EWDGAs and inter-observer variation of six preoperative biopsies was evaluated by 11 pathologists in a single institute. Based on the pathological diagnosis of the endoscopic biopsy slides, the average rate of definite malignancy diagnosis was 15.2 %, and the overall diagnostic concordance rate was 34.9 % among 11 pathologists. Microscopically, the surface epithelium was preserved and only a few atypical tumor glands were scattered in most endoscopic biopsies. Structural atypia was minimal, and the tumor glands were barely distinguishable from normal glands. Although nuclear atypia was minimal, enlarged nuclei, relatively large glands with irregular shapes, and abundant cytoplasmic mucin were observed in gastric pinch biopsies. In preoperative biopsies, no cases showed p53 overexpression, and Ki-67 labeling index ranged from 3 % to 35 % and was higher compared to non-neoplastic glands in 3 cases. After gastrectomy, four (57.1 %) patients had advanced gastric cancer and three (42.9 %) had lymph node metastasis. Genomic profiling of the four patients revealed mutations of TP53, BRAF, KRAS, STK11, and MDM2/CCND1 amplification. Immunohistochemistry for p53 was not helpful while Ki-67 may be helpful when staining pattern is distinct from the non-neoplastic mucosa. In conclusion, it is challenging to diagnose EWDGA using biopsy specimens. Recognizing and addressing this rare entity will increase diagnostic accuracy to ensure the early diagnosis of cancer.

A Case Study of a High-Grade Serous Carcinoma of the Fallopian Tube Transformed into Carcinosarcoma at the Site of Peritoneal Dissemination With Immunohistological Evidence of an Epithelial-Mesenchymal Transition.

We report a patient in whom a primary high-grade serous carcinoma (HGSC) of the fallopian tube transformed into a carcinosarcoma at the site of peritoneal dissemination, and immunohistological analysis suggested the involvement of an epithelial-mesenchymal transition (EMT). The patient, a 70-year-old woman, had an abdominal mass palpated on admission, and a laparotomy was performed after a close examination. The resected right fallopian tube was cystically dilated, and a solid mass was observed in its lumen. The histological diagnosis was HGSC of the right fallopian tube with a papillary or complex tubular structure composed of tumor cells with marked nuclear irregularities. p53 was overexpressed, and no mesenchymal tumor component was observed. The resected left-sided abdominal mass of the omentum was a solid with a long diameter of 100 mm. Microscopically, the tumor exhibited a mixture of HGSC and high-grade sarcoma with nonspecific differentiation. Furthermore, a heterologous chondrosarcoma was subsequently observed from the high-grade sarcoma. The HGSC component was E-cadherin positive. The high-grade sarcoma component was positive for EMT-related proteins such as zinc finger E-box-binding homeobox 1 (ZEB1) and twist family bHLH transcription factor 1 (TWIST1). The chondrosarcoma component was ZEB1 positive and TWIST1 negative. p53 overexpression was found in all 3 components. The tumor of the omentum suggested that an EMT phenomenon was involved in the tumorigenesis. In this scenario, the primary HGSC of the fallopian tube with obvious invasion demonstrated that the conversion from carcinoma to sarcoma by EMT occurs only with peritoneal dissemination.

Impact of clonal TP53 mutations with loss of heterozygosity on adjuvant chemotherapy and immunotherapy in gastric cancer

BackgroundThis study aimed to reveal the effect of TP53 status on clinical outcomes and underlying mechanism in gastric cancer (GC) patients.MethodsTP53 status was divided into three groups according to genome sequencing, namely clonal mutations with LOH (C-LOH), clonal diploid or subclonal mutations (CD-SC), and wild type (WT). The p53 protein activity was divided into over-expression (OE), Null and WT according to immunohistochemical staining. Four cohorts, including the TCGA, SMC, ZSHS and FUSCC cohort, were analyzed for association between TP53 mutation status and clinical outcomes and the underlying mechanism.ResultsIn TCGA cohort, TP53 CD-SC were associated with superior overall survival compared to TP53 C-LOH cases. GC patients could benefit from ACT only in TP53 CD-SC/ p53 OE and TP53/ p53 WT subgroups, and TP53 C-LOH subgroup demonstrated the worst response to pembrolizumab among three subgroups. Genomic and immunophenotypic deconvolution revealed that TP53 C-LOH, CD-SC and WT differed for genomic and immune-related features.ConclusionsTP53 C-LOH GCs with genomic instability and immune evasion phenotype have poor clinical outcomes in patients treated with ACT or immunotherapy.

Melatonin mitigates the lipopolysaccharide-induced myocardial injury in rats by blocking the p53/xCT pathway-mediated ferroptosis.

This article examined the therapeutic effect of melatonin (MT) on the lipopolysaccharide (LPS)-induced myocardial injury, and the mechanisms involved. Septic rat model was constructed by exposing to lipopolysaccharide (LPS), and treated by MT, Ferrostatin-1 (Fer-1) and Erastin (Era). Hematoxylin-eosin staining was executed to appraise myocardial injury. H9c2 cells that exposed to LPS to induce in vitro sepsis cell model were treated by MT. p53 overexpression vectors were transfected into H9c2 cells. Inflammation- and ferroptosis-related indicators were examined by enzyme-linked immunosorbent assay. Expression of p53, xCT and GPX4 was scrutinized by quantitative real-time polymerase chain reaction and Western blot. MT relieved myocardial injury in septic rats. It decreased IL-6 and TNF-α, elevated GPX4 and GSH, and reduced MDA and Fe2+ in myocardial tissues of septic rats. LPS induced p53 elevation and xCT reduction in rats' myocardial tissues. Nevertheless, MT treatment declined p53 and increased xCT in myocardial tissues of septic rats. Interestingly, the relieving effect of MT on myocardial injury in septic rats was enhanced by Fer-1, but reversed by Era. The LPS-induced H9c2 cell damage was relieved by MT treatment. Besides, MT decreased LDH, IL-6 and TNF-α, elevated xCT, GPX4 and GSH, and reduced MDA and Fe2+ in the LPS-induced H9c2 cells. Conversely, these influences of MT on the LPS-induced H9c2 cells were reversed by p53 overexpression. MT is proposed to be a promising agent for treating the LPS-induced myocardial injury, as it relieves myocardial injury by hindering the p53/xCT-mediated ferroptosis in the LPS-induced septic rats.

Sinonasal Squamous Cell Carcinoma with DEK::AFF2 Rearrangement : An Aggressive Cancer with Bland Morphology.

DEK::AFF2 squamous cell carcinoma is a recently described cancer entity, with 29 cases reported to date. Occasionally, these carcinomas appear deceptively indistinguishable; however, specific morphological and phenotypic features suggest the presence of this rearrangement. However, the prognostic value of this diagnosis remains unclear. We aimed to report a new case series with histological, molecular, and clinical features. We collected data from 15 patients and investigated their phenotypes, including the expression profiles of CK7, P63/P40, PDL1, AFF2, and P16, morphological features, and associated prognostic data. We analyzed these data along with the previously published data. Most of these cases exhibited indicative morphological features, such as exophytic and endophytic papillary growth, nuclear monomorphism, and abundant neutrophil-rich inflammatory infiltrates. Immunohistochemical analysis revealed the expression of AFF2 and squamous cell markers in all the patients. Overexpression of P16 was not detected, whereas CK7 and PDL1 were expressed variably. In our study cohort, a 50% progression or recurrence rate, 25% lymph node metastasis, 17% distant metastasis, and 18% disease-related death were identified, with a short follow-up time. DEK::AFF2 squamous cell carcinoma incidence is probably underestimated. The low-grade appearance of these tumors sometimes limits their detection. The rates of recurrence and metastasis seem to be high despite an often bland morphology. We propose AFF2 immunohistochemistry as an effective tool, and a diagnostic algorithm has been established to support accurate diagnosis of these tumors.

Trophoblast fusion in fetal growth restriction is inhibited by CTGF in a cell-cycle-dependent manner.

Fetal growth restriction (FGR) is a relatively common complication of pregnancy, and insufficient syncytialization in the placenta may play an important role in the pathogenesis of FGR. However, the mechanism of impaired formation of the syncytiotrophoblast layer in FGR patients requires further exploration. In the present study, we demonstrated that the level of syncytialization was decreased in FGR patient placentas, while the expression of connective tissue growth factor (CTGF) was significantly upregulated. CTGF was found to inhibit trophoblast fusion via regulating cell cycle progress of BeWo cells. Furthermore, we found that CTGF negatively regulates cell cycle arrest in a p21-dependent manner as overexpression of p21 could rescue the impaired syncytialization induced by CTGF-overexpression. Besides, we also identified that CTGF inhibits the expression of p21 through ITGB4/PI3K/AKT signaling pathway. Our study provided a new insight for elucidating the pathogenic mechanism of FGR and a novel idea for the clinical therapy of FGR.

Abstract Tu089: p21 Regulates Hypertrophic Cardiomyopathy Remodeling By Inhibition of Cardiomyocyte Endoreplication

Background: We previously discovered that a murine model of hypertrophic cardiomyopathy had increased cardiomyocyte endoreplication and replication stress leading to increased DNA damage. Activation of DNA damage response pathways was associated with increased cardiomyocyte expression of the cyclin-dependent kinase inhibitor p21. However, the role of p21 on pathologic myocardial remodeling in hypertrophic cardiomyopathy is poorly understood. Methods: We utilized a murine model of hypertrophic cardiomyopathy that is deficient in cardiac myosin binding protein 3 (Mybpc3 -/- ). We used murine models deficient in p21 (Cdkn1a -/- ) or overexpressed p21 (Cdkn1a SUPER ) to determine the role of p21 on hypertrophic remodeling. Heart structure and function were evaluated by echocardiography. Flow cytometry and immunohistochemistry were used to measure cardiomyocyte DNA content and ploidy. Proteomics and biochemical assays were utilized to identify p21 target proteins. Results: We observed that there was an increased p21 expression in Mybpc3 -/- cardiomyocytes during the postnatal day 7 to 25 time interval. Elimination of p21 expression in Mybpc3 -/- animals (Cdkn1a -/- /Mybpc3 -/- ) caused increased myocardial hypertrophy (Table 1). Conversely, selective overexpression of p21 in cardiomyocytes (Cdkn1a SUPER /Mybpc3 -/- /Myh6Cre) led to reduced myocardial hypertrophy (Table 1). We discovered that isolated cardiomyocyte nuclei from Mybpc3 -/- mice with reduced p21 had increased polyploidy whereas overexpression of cardiomyocyte p21 led to reduced cardiomyocyte polyploidy (Table 1). Using both proteomics and targeted assays we discovered that cardiomyocyte p21 was binding to key cycle regulatory proteins to inhibit cardiomyocyte endoreplication and hypertrophic growth. Conclusions: Collectively, our results show that induction of p21 in hypertrophic cardiomyopathy reduces cardiomyocyte growth by inhibiting endoreplication.

Glucocorticoid receptor controls atopic dermatitis inflammation via functional interactions with P63 and autocrine signaling in epidermal keratinocytes

Atopic dermatitis (AD), a prevalent chronic inflammatory disease with multifactorial etiology, features epidermal barrier defects and immune overactivation. Synthetic glucocorticoids (GCs) are widely prescribed for treating AD due to their anti-inflammatory actions; however, mechanisms are incompletely understood. Defective local GC signaling due to decreased production of endogenous ligand and/or GC receptor (GR) levels was reported in prevalent inflammatory skin disorders; whether this is a consequence or contributing factor to AD pathology is unclear. To identify the chromatin-bound cell-type-specific GR protein interactome in keratinocytes, we used rapid immunoprecipitation of endogenous proteins and mass spectrometry identifying 145 interactors that increased upon dexamethasone treatment. GR-interacting proteins were enriched in p53/p63 signaling, including epidermal transcription factors with critical roles in AD pathology. Previous analyses indicating mirrored AD-like phenotypes between P63 overexpression and GR loss in epidermis, and our data show an intricate relationship between these transcription factors in human keratinocytes, identifying TP63 as a direct GR target. Dexamethasone treatment counteracted transcriptional up-regulation of inflammatory markers by IL4/IL13, known to mimic AD, causing opposite shifts in GR and P63 genomic binding. Indeed, IL4/IL13 decreased GR and increased P63 levels in cultured keratinocytes and human epidermal equivalents (HEE), consistent with GR down-regulation and increased P63 expression in AD lesions vs normal skin. Moreover, GR knockdown (GRKD) resulted in constitutive increases in P63, phospho-P38 and S100A9, IL6, and IL33. Also, GRKD culture supernatants showed increased autocrine production of TH2-/TH1-/TH17-TH22-associated factors including IL4, CXCL10, CXCL11, and CXCL8. GRKD HEEs showed AD-like features including hyperplasia and abnormal differentiation, resembling phenotypes observed with GR antagonist or IL4/IL13 treatment. The simultaneous GR/P63 knockdown partially reversed constitutive up-regulation of inflammatory genes in GRKD. In summary, our data support a causative role for GR loss in AD pathogenesis via functional interactions with P63 and autocrine signaling in epidermal keratinocytes.

HADHA promotes glioma progression by accelerating MDM2-mediated p53 ubiquitination.

Glioma represents a notoriously aggressive and malignant tumor that targets the central nervous system, with a poor prognosis for patients. In this research, we set out to examine the role of hydroxyacyl-CoA dehydrogenase trifunctional multienzyme complex subunit alpha (HADHA) in glioma, its clinical significance, as well as its potential biological mechanisms. In this study, we used immunohistochemistry staining to assess the expression level of HADHA in glioma tissues. We also evaluated the correlation between HADHA expression and patient survival using the Kaplan-Meier method. To determine the role of HADHA in glioma cells, we conducted loss-of-function assays in vitro and in vivo. Additionally, we utilized co-immunoprecipitation and protein stability assays to investigate the potential mechanisms involving HADHA, MDM2, and p53 in glioma. Our research findings indicate that gliomas exhibit high levels of HADHA. Clinically, high expression of HADHA suggests an increased risk of malignant tumors, recurrence, and reduced survival rates. Functionally, knocking down HADHA can lead to decreased proliferation, enhanced apoptosis, and inhibited migration of glioma cells. Mechanistically, HADHA accelerates MDM2-mediated p53 ubiquitination through interaction with MDM2. Consistently, MDM2 knockdown or overexpression of p53 can attenuate the promoting effect of HADHA overexpression on the malignant progression of glioma. We have discovered a novel role of HADHA in promoting MDM2-mediated p53 ubiquitination, which contributes to the progression of glioma. This finding provides a new perspective to understand the pathogenesis of glioma and offers a potential target for developing innovative therapeutic strategies.

Diagnosis of laryngopharyngeal carcinoma through office-based flexible laryngoscopy as a reliable alternative for biopsies under general anesthesia: Faster diagnostics with equal oncological outcome

PurposeDiagnostic endoscopy with biopsy under general anesthesia (DE-GA) is still considered as the established standard to assess laryngopharyngeal cancer patients. Office-based flexible laryngoscopic biopsy (FLB) offers an alternative, but the effect on oncological outcome remains uncertain. Therefore, the diagnostic process and survival of patients undergoing FLB, compared to those undergoing DE-GA were evaluated. MethodsPatients suspected of laryngopharyngeal cancer who underwent FLB were evaluated. Patients with FLB-confirmed squamous cell carcinoma (SCC) were matched with DE-GA patients based on tumor site, T-classification, N-classification, age, and p16 overexpression. Time from first visit to diagnosis (FVD), time to treatment interval (TTI), disease-specific survival (DSS) and overall survival (OS) were analyzed. ResultsFLB yielded a definitive diagnosis in 155/164 (95 %) patients. No complications were observed. Ninety-eight of the 124 patients in which FLB revealed a SCC received curative treatment and were compared with 98 matched patients who underwent DE-GA. Median FVD interval was 6 days after FLB and 15 days after DE-GA (p < 0.001). Median TTI interval (FLB: 28 days, DE-GA: 28 days) was equal (p = 0.91). Oncological outcomes were comparable (p > 0.05) between FLB (OS: 2-yr: 76 %, 5-yr: 42 %; DSS: 2-yr: 86 %, 5-yr: 85 %) and DE-GA groups (OS: 2-yr: 76 %, 5-yr: 50 %; DSS: 2-yr: 81 %, 5-yr: 79 %). ConclusionFLB in the outpatient setting demonstrates a high diagnostic accuracy, is safe, accelerates the diagnostic process and has no negative effects on clinical outcome compared to DE-GA. Therefore, FLB should be considered as the standard diagnostic procedure in patients suspected of laryngopharyngeal cancer.