P53 Overexpression Research Articles

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.

Alpha-Asarone attenuates alcohol-induced hepatotoxicity in a murine model by ameliorating oxidative stress, inflammation, and modulating apoptotic-Autophagic cell death

Alcoholic liver disease (ALD) is a major cause of chronic liver injury characterized by steatosis, inflammation, and fibrosis. This study explored the hepatoprotective mechanisms of alpha-asarone in a mouse model of chronic-binge alcohol feeding. Adult male mice were randomized into control, alcohol, and alcohol plus alpha-asarone groups. Serum aminotransferases and histopathology assessed liver injury. Oxidative stress was evaluated via malondialdehyde content, glutathione, superoxide dismutase, and catalase activities. Pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 were quantified by ELISA. P53-mediated apoptosis was determined by immunohistochemistry. Key autophagy markers phospho-AMPK, AMPK, Beclin-1, LC3-I/LC3-II ratio, and LC3 were examined by immunoblotting. Alcohol administration increased serum ALT, AST and ALP, indicating hepatocellular damage. This liver dysfunction was associated with increased oxidative stress, inflammation, p53 expression and altered autophagy. Alpha-asarone treatment significantly decreased ALT, AST and ALP levels and improved histological architecture versus alcohol alone. Alpha-asarone also mitigated oxidative stress, reduced TNF-α, IL-1β and IL-6 levels, ameliorated p53 overexpression and favorably modulated autophagy markers. Our findings demonstrate that alpha-asarone confers protective effects against ALD by enhancing antioxidant defenses, suppressing hepatic inflammation, regulating apoptotic signaling, and restoring autophagic flux. This preclinical study provides compelling evidence for the therapeutic potential of alpha-asarone in attenuating alcohol-induced liver injury and warrants further evaluation as a pharmacotherapy for ALD.

Significance of p16 in Site-Specific Human Papillomavirus-Positive and Negative Head and Neck Squamous Cell Carcinoma (HNSCC).

Head and neck squamous cell carcinoma (HNSCC) represents a group of cancers characterized by diverse origins and changing epidemiological patterns. The significance of high-risk human papillomavirus (HPV) infection in certain HNSCC cases has gained attention for its impact on the disease's behavior. Our current research focused on exploring the importance of using p16 as an HNSCC biomarker, particularly in the context of HPV infection, assessing its value in prognosis, and examining its variation across different tumor locations. A retrospective analysis was carried out on 100 HNSCC patients from a tertiary care center, with particular attention paid to p16 expression, HPV status, clinic-pathological characteristics, and prognosis. HPV was detected using polymerase chain reaction (PCR) techniques, and p16 expression was evaluated by immunohistochemistry. According to the ethical guidelines outlined in the Declaration of Helsinki, multivariate analysis assessed the prognostic value of p16. Our analysis demonstrated a significant correlation between HPV status and p16 expression in HNSCC cases. A vast majority of 58 (96.7%) HPV-+cases exhibited p16 overexpression, contrasting sharply with only two (5%) in the HPV--group. Patients with tumors that were both p16+and HPV+exhibited more favorable overall survival rates. In contrast, those with p16-and HPV-tumors experienced the poorest survival outcomes. Notably, having a p16--status in HPV+cases emerged as an independent factor for reduced survival. Additionally, the study revealed distinct variations in p16 expression based on tumor location, particularly within the oropharyngeal area. The study established that p16 is a dependable indication for the existence of HPV in HNSCC and highlights its significant role as a prognostic factor, particularly in cases that are p16--yet HPV-+. These findings underscore the importance of adopting site-specific treatment approaches in HNSCC management and contribute to a deeper understanding of p16's role in the disease, thereby aiding in more effective risk assessment and treatment planning.

Low-dose dimethylfumarate attenuates colitis-associated cancer in mice through M2 macrophage polarization and blocking oxidative stress

Colitis-associated cancer (CAC) is an aggressive subtype of colorectal cancer that can develop in ulcerative colitis patients and is driven by chronic inflammation and oxidative stress. Current chemotherapy for CAC, based on 5-fluorouracil and oxalipltin, is not fully effective and displays severe side effects, prompting the search for alternative therapies. Dimethylfumarate (DMF), an activator of the nuclear factor erythroid 2–related factor 2 (NRF2), is a potent antioxidant and immunomodelatrory drug used in the treatment of multiple sclerosis and showed a strong anti-inflammatory effect on experimental colitis. Here, we investigated the chemotherapeutic effect of DMF on an experimental model of CAC. Male NMRI mice were given two subcutaneous injections of 1,2 Dimethylhydrazine (DMH), followed by three cycles of dextran sulfate sodium (DSS). Low-dose (DMF30) and high-dose of DMF (DMF100) or oxaliplatin (OXA) were administered from the 8th to 12th week of the experiment, and then the colon tissues were analysed histologically and biochemically. DMH/DSS induced dysplastic aberrant crypt foci (ACF), oxidative stress, and severe colonic inflammation, with a predominance of pro-inflammatory M1 macrophages. As OXA, DMF30 reduced ACF multiplicity and crypt dysplasia, but further restored redox status, and reduced colitis severity by shifting macrophages towards the anti-inflammatory M2 phenotype. Surprisingly, DMF100 exacerbated ACF multiplicity, oxidative stress, and colon inflammation, likely through NRF2 and p53 overexpression in colonic inflammatory cells. DMF had a dual effect on CAC. At low dose, DMF is chemotherapeutic and acts as an antioxidant and immunomodulator, whereas at high dose, DMF is pro-oxidant and exacerbates colitis-associated cancer.

The Aberrant Expression of Biomarkers and Risk Prediction for Neoplastic Changes in Barrett's Esophagus-Dysplasia.

Background: Barrett's esophagus (BE) is a pre-neoplastic condition associated with an increased risk of esophageal adenocarcinoma (EAC). The accurate diagnosis of BE and grading of dysplasia can help to optimize the management of patients with BE. However, BE may be missed and the accurate grading of dysplasia based on a routine histology has a considerable intra- and interobserver variability. Thus, well-defined biomarker testing remains indispensable. The aim of our study was to identify routinely applicable and relatively specific biomarkers for an accurate diagnosis of BE, as well as determining biomarkers to predict the risk of progression in BE-dysplasia. Methods: Retrospectively, we performed immunohistochemistry to test mucin 2(MUC2), trefoil factor 3 (TFF3), p53, p16, cyclin D1, Ki-67, beta-catenin, and minichromosome maintenance (MCM2) in biopsies. Prospectively, to identify chromosomal alterations, we conducted fluorescent in situ hybridization testing on fresh brush samples collected at the time of endoscopy surveillance. Results: We discovered that MUC2 and TFF3 are specific markers for the diagnosis of BE. Aberrant expression, including the loss and strong overexpression of p53, Ki-67, p16, beta-catenin, cyclin D1, and MCM2, was significantly associated with low-grade dysplasia (LGD), high-grade dysplasia (HGD), and EAC histology, with a relatively high risk of neoplastic changes. Furthermore, the aberrant expressions of p53 and p16 in BE-indefinite dysplasia (IND) progressor cohorts predicted the risk of progression. Conclusions: Assessing the biomarkers would be a suitable adjunct to accurate BE histology diagnoses and improve the accuracy of BE-dysplasia grading, thus reducing interobserver variability, particularly of LGD and risk prediction.

Clinical Significance of Human Papillomavirus DNA Test and p16 Overexpression in Oropharyngeal Cancer

Background and Objectives Oropharyngeal squamous cell carcinoma (OPSCC) can be caused by human papilloma virus (HPV) infection or other factors like smoking. The 8th Edition of the AJCC Cancer Staging Manual recommends different staging and treatment approaches based on etiology. Despite criticisms of its low specificity, the current guidelines suggest using p16 immunohistochemistry (IHC) as a surrogate marker for the HPV-related OPSCC. This study assessed the reliability of p16 as a surrogate marker by correlating the survival rates of OPSCC patients with the results of p16 IHC and HPV-DNA testing.Subjects and Method A retrospective analysis was performed on patients treated for tonsil squamous cell carcinoma at a tertiary medical institution between 1994 and 2018. All patients underwent p16 immunostaining and HPV-DNA chip tests. Out of 88 patients, 17 were excluded due to insufficient data or secondary primary cancer, leaving 71 patients.Results Among the 71 patients, 51 were p16 positive and 49 were HPV-DNA positive; both tests were associated with extended survival. However, discrepancies were noted in 18 patients: specifically, 11 patients were p16 positive but HPV-DNA negative, displaying a different survival pattern compared to HPV-associated and non-HPV-associated patients.Conclusion Both p16 immunostaining and HPV-DNA testing have their pros and cons. p16 immunostaining is cost-effective but has lower specificity. The study found discrepancies in 18 patients, suggesting that relying solely on p16 immunostaining may have limitations. It would be advisable to complement it with additional tests like the HPV-DNA chip test to predict the disease’s prognosis more accurately.

An extensive immunohistochemical analysis of 290 ovarian adult granulosa cell tumors with 29 markers.

The current knowledge about the immunohistochemical features of adult granulosa cell tumor (AGCT) is mostly limited to the "traditional" immunohistochemical markers of sex cord differentiation, such as inhibin, calretinin, FOXL2, SF1, and CD99. Knowledge about the immunohistochemical markers possibly used for predictive purpose is limited. In our study, we focused on the immunohistochemical examination of 290 cases of AGCT classified based on strict diagnostic criteria, including molecular testing. The antibodies used included 12 of the "diagnostic" antibodies already examined in previous studies, 10 antibodies whose expression has not yet been examined in AGCT, and 7 antibodies with possible predictive significance, including the expression of HER2, PD-L1, CTLA4, and 4 mismatch repair (MMR) proteins. The results of our study showed expression of FOXL2, SF1, CD99, inhibin A, calretinin, ER, PR, AR, CKAE1/3, and CAIX in 98%, 100%, 90%, 78%, 45%, 41%, 94%, 82%, 26%, and 9% of AGCT, respectively. GATA3, SATB2, napsin A, MUC4, TTF1, and CD44 were all negative. PTEN showed a loss of expression in 71% of cases and DPC4 in 4% of cases. The aberrant staining pattern (overexpression) of p53 was found in 1% (3/268) of cases, 2 primary tumors, and 1 recurrent case. Concerning the predictive markers, the results of our study showed that AGCT is microsatellite stable, do not express PD-L1, and are HER2 negative. The CTLA4 expression was found in almost 70% of AGCT tumor cells.

Expression of p53 and ki-67 in Breast Carcinomas and Their Association with Histopathological Type, Grade, and Stage

Background &amp; objective: Recently many laboratories are evaluating the usefulness of determining p53, and Ki67 proliferation activities using immunohistochemical techniques in cancer. Although the available studies suggest that these factors might help make treatment decisions in cancer patients, their clinical usefulness is still controversial. The present study was undertaken to see the expression of p53 and Ki-67 in breast carcinoma and their associations with histopathological variables. Methods: This cross-sectional analytical study was conducted in the Department of Pathology, in collaboration with the Department of Surgery, Rajshahi Medical College Hospital and the Department of Pathology, Bangobandhu Sheikh Mujib Medical University (BSMMU), Dhaka over a period of one and a half year from July 2018 to December 2019. Resected specimens of breast tissue, histopathologically confirmed as breast carcinoma, were the study population. Histological grading of breast carcinoma was done according to Nottingham modification of the Bloom-Richardson system, while staging was done using Tumor-Node-Metastasis (TNM) classification of malignant tumors, as recommended by the Union for International Cancer Control (UICC). The Ki67 and p53 expressions were assessed by immunohistochemistry. Based on the Ki67 labeling index (Ki67-LI), the patients were divided into two groups – Ki 67 &gt; 30% (considered as over-expressed) and ≤ 30% (considered as less expressed). Likewise, p53 immuno-expression was grouped as over-expressed (score ≤ 8) and low-expressed (score &gt; 8). The histological grade, type, and stage were then compared between patients with tumours of high and low proliferating activities to find the associations of Ki67 and p53 with tumor grade, type, and stage. Result: In the present study, almost three-quarters (74%) of the specimen of the breast had high Ki67-LI and 26% intermediate and low Ki67-LI. The p53 was found to be highly expressed in the majority (86%) of the cases. Analyses of the association of biomarkers with histological grade, stage, and type revealed that advanced-stage breast cancers (Stage-IIIA) were more likely to be associated with high Ki67-LI than the early-stage breast cancers (Stage-IIA and Stage-IIB) (p = 0.023). Poorly differentiated (G3) carcinoma also more often tends to be associated with high Ki67-LI than with low and intermediate Ki67-LI (p = 0.066). Likewise, stage IIIA tumors and poorly differentiated carcinoma were also considerably higher in the p53 over-expressed group (23.3%) than in the low p53 expression group (14.3%) (p = 0.023). Conclusion: The study concluded that a substantial proportion of breast carcinomas demonstrates high Ki67-LI. The p53 overexpression is also found in the majority (86%) of the breast carcinoma cases. Both Ki67 and p53 proliferation activities show their significant presence in high-grade and advanced-stage tumours. Ibrahim Card Med J 2023; 13 (1&amp;2): 11-18

Reactive Oxygen Species Induction by Hepatitis B Virus: Implications for Viral Replication in p53-Positive Human Hepatoma Cells.

Hepatitis B virus (HBV) infects approximately 300 million people worldwide, causing chronic infections. The HBV X protein (HBx) is crucial for viral replication and induces reactive oxygen species (ROS), leading to cellular damage. This study explores the relationship between HBx-induced ROS, p53 activation, and HBV replication. Using HepG2 and Hep3B cell lines that express the HBV receptor NTCP, we compared ROS generation and HBV replication relative to p53 status. Results indicated that HBV infection significantly increased ROS levels in p53-positive HepG2-NTCP cells compared to p53-deficient Hep3B-NTCP cells. Knockdown of p53 reduced ROS levels and enhanced HBV replication in HepG2-NTCP cells, whereas p53 overexpression increased ROS and inhibited HBV replication in Hep3B-NTCP cells. The ROS scavenger N-acetyl-L-cysteine (NAC) reversed these effects. The study also found that ROS-induced degradation of the HBx is mediated by the E3 ligase Siah-1, which is activated by p53. Mutations in p53 or inhibition of its transcriptional activity prevented ROS-mediated HBx degradation and HBV inhibition. These findings reveal a p53-dependent negative feedback loop where HBx-induced ROS increases p53 levels, leading to Siah-1-mediated HBx degradation and HBV replication inhibition. This study offers insights into the molecular mechanisms of HBV replication and identifies potential therapeutic targets involving ROS and p53 pathways.

Identification of HTRA4 as a Transcriptional Target of p63 in Trophoblast

The placenta plays a crucial role in pregnancy success. ΔNp63α (p63), a transcription factor from the TP53 family, is highly expressed in villous cytotrophoblasts (CTBs), the epithelial stem cells of the human placenta, and is involved in CTB maintenance and differentiation. We examined the mechanisms of action of p63 by identifying its downstream targets. Gene expression changes were evaluated following overexpression and knockdown of p63 in the JEG3 choriocarcinoma cell line, using microarray-based RNA profiling. High-temperature requirement A4 (HTRA4), a placenta-specific serine protease involved in trophoblast differentiation and altered in preeclampsia, was identified as a gene reciprocally regulated by p63, and its expression was characterized in primary human placental tissues by RNA-sequencing and in situ hybridization. Potential p63 DNA-binding motifs were identified in the HTRA4 promoter, and p63 occupancy at some of these sites was confirmed using chromatin immunoprecipitation, followed by quantitative PCR in both JEG3 and trophoblast stem cells. These data begin to identify members of the transcriptional network downstream of p63, thus laying the groundwork for probing mechanisms by which this important transcription factor regulates trophoblast stemness and differentiation.

Transient growth factor expression via mRNA in lipid nanoparticles promotes hepatocyte cell therapy in mice

Primary human hepatocyte (PHH) transplantation is a promising alternative to liver transplantation, whereby liver function could be restored by partial repopulation of the diseased organ with healthy cells. However, currently PHH engraftment efficiency is low and benefits are not maintained long-term. Here we refine two male mouse models of human chronic and acute liver diseases to recapitulate compromised hepatocyte proliferation observed in nearly all human liver diseases by overexpression of p21 in hepatocytes. In these clinically relevant contexts, we demonstrate that transient, yet robust expression of human hepatocyte growth factor and epidermal growth factor in the liver via nucleoside-modified mRNA in lipid nanoparticles, whose safety was validated with mRNA-based COVID-19 vaccines, drastically improves PHH engraftment, reduces disease burden, and improves overall liver function. This strategy may overcome the critical barriers to clinical translation of cell therapies with primary or stem cell-derived hepatocytes for the treatment of liver diseases.

P53 Expression in Sporadic Colorectal Carcinoma

Objective: To determine expression of p53 in colorectal carcinoma (CRC) tissues and to find the frequency of p53 over-expression in various stages and grades of tumor. Methodology: A prospective observational design study was conducted at BMSI JPMC between January 2023 till October 2023, after obtaining approval from ethics review committee. Fifty-six patients of CRC were recruited and the tumor tissue was subjected to H&amp;E staining. The extent of nuclear immunoreactivity of p53 was scored from 0-3. The intensity was score from mild to strong, with score zero for no intensity. The results of immunohistochemistry were used to determine frequency of p53 over-expression with Astler and Coller grading and staging system and TNM staging. Results: There were 30 cases (53.5 %) cases which showed p53 over-expression. The Astler and Coller grading and staging system showed that the majority of cases were in stage B2 (44.6%) followed by C2. As compared to other stages, TNM stage 3 showed higher frequency of p53 overexpression. Conclusion: there is high frequency of p53 over-expression which highlights its significance. The over-expression has been found in higher stage and grade which indicates that it may form a key molecular event that may act as a prognostic as well as possible therapeutic marker.

Redefining aberrant P53 expression of gastric cancer and its distinct clinical significance among molecular-histologic subtypes

BackgroundNumerous studies have demonstrated a correlation between p53 overexpression and diminished survival in gastric cancer patients. However, conflicting findings exist, and we hypothesize that these discrepancies arise from the cancer's complexity and heterogeneity, coupled with a lack of consensus on aberrant p53 expression. MethodsWe enrolled a cohort of 187 patients with surgically resected gastric cancer. Patient categorization was based on Epstein–Barr virus (EBV), microsatellite instability (MSI), and Lauren classification (intestinal, diffuse and mixed). Utilizing an incremental algorithm, we evaluated p53 immunohistochemical (IHC) patterns in all 187 cases, while next-generation sequencing was successfully performed on 152 cases to identify TP53 mutations (mutTP53). ResultsMutTP53 was identified in 32 % of the 152 cases, comprising 36 missense, 5 nonsense, and 7 frameshift alterations. Missense mutations predominantly correlated with p53 overexpression, while nonsense and frameshifting alterations related to null expression. Trial calculations indicated that null expression and a p53 IHC cutoff at >40 % offered the best prediction of mutTP53 (kappa coefficient, 0.427), with the highest agreement (0.524) observed in diffuse type and the lowest (0.269) in intestinal type. Null expression and a p53 IHC cutoff at >10 %, but not mutTP53 per se, provided the optimal prediction of survival outcome (p = 0.043), particularly in diffuse type (p = 0.044). Multivariate analysis showed that aberrant p53 IHC expression was not an independent prognostic factor. ConclusionsP53 IHC patterns are predictive biomarkers for mutTP53 and gastric cancer outcomes, where a prerequisite involves a nuanced approach considering cutoff values and molecular-histologic subtyping.

Comprehensive single cell transcriptomics analysis of murine osteosarcoma uncovers Skp2 function in metastasis, genomic instability and immune activation and reveals additional target pathways.

Osteosarcoma (OS) is the most common primary pediatric bone malignancy. One promising new therapeutic target is SKP2, encoding a substrate recognition factor of the SCF E3 ubiquitin ligase responsible for ubiquitination and proteasome degradation of substrate p27, thus driving cellular proliferation. We have shown previously that knockout of Skp2 in an immunocompetent transgenic mouse model of OS improved survival, drove apoptosis, and induced tumor inflammation. Here, we applied single-cell RNA-sequencing (scRNA-seq) to study primary OS tumors derived from Osx-Cre driven conditional knockout of Rb1 and Trp53. We showed that murine OS models recapitulate the tumor heterogeneity and microenvironment complexity observed in patient tumors. We further compared this model with OS models with functional disruption of Skp2: one with Skp2 knockout and the other with the Skp2-p27 interaction disrupted (resulting in p27 overexpression). We found reduction of T cell exhaustion and upregulation of interferon activation, along with evidence of replicative and endoplasmic reticulum-related stress in the Skp2 disruption models, and showed that interferon induction was correlated with improved survival in OS patients. Additionally, our scRNA-seq analysis uncovered decreased activities of metastasis-related gene signatures in the Skp2-disrupted OS, which we validated by observation of a strong reduction in lung metastasis in the Skp2 knockout mice. Finally, we report several potential mechanisms of escape from targeting Skp2 in OS, including upregulation of Myc targets, DNA copy number amplification and overexpression of alternative E3 ligase genes, and potential alternative lineage activation. These mechanistic insights into OS tumor biology and Skp2 function suggest novel targets for new, synergistic therapies, while the data and our comprehensive analysis may serve as a public resource for further big data-driven OS research.

Gastric dysplastic lesions in Helicobacter pylori-naïve stomach: Foveolar-type adenoma and intestinal-type dysplasia.

Reports of Helicobacter pylori (Hp)-naïve gastric neoplasm (HpNGN) cases have been rapidly increasing due to the recent increase in the Hp-naïve population in Japan. Most HpNGNs exhibit the gastric immunophenotype and a low malignant potential regardless of histological type. Especially, foveolar-type gastric adenoma (FGA) and intestinal-type gastric dysplasia (IGD) rarely progress to invasive carcinoma. FGA is a foveolar epithelial neoplasm that occurs in the fundic gland (oxyntic gland) mucosa and is classified as the flat type or raspberry type (FGA-RA). The flat type is a large, whitish flatly elevated lesion while FGA-RA is a small reddish polyp. Genomically, the flat type is characterized by APC and KRAS gene mutations and FGA-RA by a common single nucleotide variant in the KLF4 gene. This KLF4 single-nucleotide variant reportedly induces gastric foveolar epithelial tumorigenesis and activates both cell proliferation and apoptosis, leading to its slow-growing nature. IGD consists of an intestinalized epithelial dysplasia that develops in the pyloric gland mucosa, characterized as a superficial depressed lesion surrounded by raised mucosa showing a gastritis-like appearance. Immunohistochemically, it exhibits an intestinal or gastrointestinal phenotype and, frequently, p53 overexpression. Thus, IGD shows unique characteristics in HpNGNs and a potential multistep tumorigenic process.

DCAF2 regulates the proliferation and differentiation of mouse progenitor spermatogonia by targeting p21 and thymine DNA glycosylase.

DDB1-Cullin-4-associated factor-2 (DCAF2, also known as DTL or CDT2), a conserved substrate recognition protein of Cullin-RING E3 ligase 4 (CRL4), recognizes and degrades several substrate proteins during the S phase to maintain cell cycle progression and genome stability. Dcaf2 mainly expressed in germ cells of human and mouse. Our study found that Dcaf2 was expressed in mouse spermatogonia and spermatocyte. The depletion of Dcaf2 in germ cells by crossing Dcaf2fl/fl mice with stimulated by retinoic acid gene 8(Stra8)-Cre mice caused a reduction in progenitor spermatogonia and differentiating spermatogonia, eventually leading to the failure of meiosis initiation and male infertility. Further studies showed that depletion of Dcaf2 in germ cells caused abnormal accumulation of the substrate proteins, cyclin-dependent kinase inhibitor 1A (p21) and thymine DNA glycosylase (TDG), decreasing of cell proliferation, increasing of DNA damage and apoptosis. Overexpression of p21 or TDG attenuates proliferation and increases DNA damage and apoptosis in GC-1 cells, which is exacerbated by co-overexpression of p21 and TDG. The findings indicate that DCAF2 maintains the proliferation and differentiation of progenitor spermatogonia by targeting the substrate proteins p21 and TDG during the S phase.

P63 Expressing Adenocarcinoma of The Prostate Gland, A Rare Neoplasm Which Tends to Pose Diagnostic Dilemma Sometimes: Review and Update

It has been documented that prostate cancer is the world's leading cause of cancer and also the second commonest cancer in men which does tend to pose challenges in its diagnosis. It has been iterated that immunohistochemistry studies utilising tumour markers like high molecular weight cytokeratin, p63 aid in the diagnosis of prostate cancer. It has been known for some time that the absence of immunohistochemistry staining of prostate lesion for p63 and high molecular weight cytokeratin and presence of p504s in the biopsies indicate malignant lesions. Nevertheless, it had also been pointed out as well as documented that some rare cases of adenocarcinoma of prostate variants do demonstrate evidence of the tumour cells exhibiting p63 immunohistochemistry staining and this does pose a diagnostic dilemma that may make the unfamiliar pathologist mis-diagnose such a malignant tumour as a benign prostate lesion. p63-positive adenocarcinoma of the prostate gland is a major diagnostic pitfall. There is a danger of interpreting malignant glands as benign and arriving at a false-negative diagnosis. This can be prevented by the understanding of the pattern of immunohistochemistry staining expression related to this variant of prostate cancer. The major points that favour the diagnosis of carcinoma in these cases include: non-basal p63 staining and negative HWMCK and positive p504s staining. The biological behaviour of this particular rare variant of prostatic carcinoma is not certain and requires to be studied further into more detail. Considering the rarity of p63 expressing prostate cancers and the fact that most clinicians including pathologists, urologists, and oncologists would not have encountered a case of p63 expressing prostate cancer before in order to update all clinicians regarding this rare tumour, the ensuing article has been extensively written and divided into two parts: (A) Overview which has discussed general overview aspects of p63 expressing neoplasms and (B) Miscellaneous Narrations and Discussions from Some Case Reports, Case Series, and Studies Related to Primary p63 Expressing Adenocarcinomas of the Prostate Gland. A high-index of suspicion as well as knowledge of the histopathology examination features as well as immunohistochemistry examination features of this rare tumour is required from all clinicians. Knowledge of the treatment options, biological behaviour as well as outcome following treatment of the tumour has been extensively discussed as updating information. The update has clearly pointed out that further studies are required to determine the role of p63 overexpression in prognostication.