P53 Antibodies Research Articles

Sensitive sandwich-type electrochemical immunosensing of p53 protein based on Ti3C2Tx MXene nanoribbons and ferrocene/gold

Since the p53 protein is an important promising biomarker of lung tumor and colorectal tumor, it is very essential to design a highly effective mean to monitor the degree of p53 for the early clinical analysis/therapy of the related tumors. In this work, a sandwich-type electrochemical immunosensing (SES) platform is proposed for the first time to detect p53 via synthesizing Ti3C2Tx MXene nanoribbons (Ti3C2Tx Nb) and ferrocene/gold nanoparticles (Fc/Au) respectively as the sensing substrate and signal-amplifier. The superior electrical property and large surface area of Ti3C2Tx Nb are beneficial to assemble the initial p53-antibodies (Ab1), while the synthesized Fc/Au is devoted to assemble the secondary p53 antibodies (Ab2) and gives a magnified signal. By adopting the Fc molecules as the probes, the experiments reveal the response current of Fc resulted from the SES structure increases along with the p53 increase from 1.0 to 200.0 pg mL−1. A considerable low detection limit (1.0 pg mL−1) is achieved after optimizing several key conditions, it is thus confirmed the as-proposed SES mean exhibits significant application in the detection of p53 protein and other targets.

Role of Beta Catenin, GAB1, YAP1 and P53 Antibodies in the Molecular Classification of Medulloblastoma: Analysis of a Series of 68 Cases

Role of Beta Catenin, GAB1, YAP1 and P53 Antibodies in the Molecular Classification of Medulloblastoma: Analysis of a Series of 68 Cases

PRAME and Historical Immunohistochemical Antibodies Ki-67, P16, and HMB-45 in Ambiguous Melanocytic Tumors.

Ambiguous melanocytic lesions/tumors (AMLs) can be simply described as melanocytic neoplasms that cannot be differentiated as either a melanoma or a nevus. Preferentially expressed antigen in melanoma (PRAME) is a novel antibody that can help differentiate between nevi and melanomas. However, its usefulness remains controversial in AMLs. The aim of this study was to demonstrate the importance of PRAME and diagnostic auxiliary antibodies (Ki-67, p16, HMB-45) in the diagnosis of melanocytic lesions, especially in AMLs. This study included 52 ambiguous melanocytic lesions, 40 nevi, and 40 melanomas. All immunohistochemical studies were performed automatically using the Universal Alkaline Phosphatase Red Detection Kit. Different analytic approaches were used for each antibody based on the literature. Statistically, the multinomial forward stepwise elimination logistic regression analysis was used to create a statistical model to predict the diagnosis of melanocytic lesions based on clinical, morphological, and immunohistochemical data. PRAME positivity was very strong and diffuse in the melanoma group and statistically significantly higher than that of the AML and nevus groups. There was no statistically significant difference between the nevus and AML groups. The Ki-67 proliferation index and HMB-45 staining pattern provided valuable indications for distinguishing between these 3 groups. The P16 antibody was limited in supporting the differential diagnosis. Our statistical model showed that a high mitosis count, central pagetoid spread, and PRAME positivity increased the probability of melanoma against an AML diagnosis. This study showed the advantages of evaluating the PRAME antibody together with morphological features and other immunohistochemical markers (Ki-67 and HMB-45) in the differential diagnosis of melanocytic lesions.

Assessing the diagnostic impact of P63, PSA and BCL-2 proteins in premalignant and malignant prostate tissues

Background: Prostate cancer (CaP) is increasingly becoming a major health issue affecting men as cancer-related fatalities are attributable to the condition. Immunohistochemistry (IHC) diagnostic criteria can help in gene-targeted therapy and help reduce its prevalence. This study is to assess the diagnostic impact of prostate-specific antigen (PSA), P63 and BCL-2 antibodies in CaP. Method: A case-controlled retrospective study was carried out on eighty (80) prostrate tissue blocks retrieved from the pathology archive of Ekiti State university teaching hospital Ado Ekiti. IHC analysis of the selected antibodies was carried out and also stained with haematoxylin and eosin (H and E) for second opinion and confirmation. Results: The study showed that all the CaP samples had 100% positivity with varying reactivity to the IHC biomarkers; PSA had 100% positivity and MPR of 94% due to its multiple weaknesses as a biomarker p63 is a basal cells marker. Conclusions: The expressions of these antibodies were observed in the progression of CaP. Although these markers are useful in predicting the progression from benign prostatic hyperplasia (BPH) to CaP, none of them can be utilised in isolation to a conclusion. Hence, they should be used in conjunction with one another to make up for their limitations. The immunohistochemical markers are beneficial in CaP diagnosis.

Cytoplasmic PPARγ Significantly Correlates With P53 Immunohistochemical Expression and Tumor Size in Localized Tenosynovial Giant Cell Tumor.

Tenosynovial giant cell tumor (TGCT)is a monoarticular fibrohistiocytic benign or locally aggressive soft tissue tumor that originates from the synovium of joints, bursae, and tendon sheaths.It has an inflammatory neoplastic nature, with a clinical presentationranging from pain, swelling, stiffness, and limited range of movement to joint instability and blockage. Its uncommon incidence leads to a poorly understood pathogenesis. Localized formsof TGCT (LTGCT) can cause significant morbidity, interfere with daily patient activities, and decrease the patient's quality of life in challenging cases. This study aimed to investigate the immunohistochemical expression of PPARγ (peroxisome proliferator-activated receptor gamma) and P53 in LTGCT to understand the disease better and offer potential therapeutic targets. The study is cross-sectional, in which 27 LTGCT cases were collectedfrom the Pathology Department, Faculty of Medicine, Cairo University, Cairo, Egypt.Solitary and multiple LTGCT cases retrieved between January 2018 and December 2022 were included, and immunohistochemically stained with anti-PPARγ and P53 antibodies. The TGCT samples were excluded if they were insufficient for sectioning, processing, and interpretation, over-fixed, had process artifacts, or were of the diffuse TGCT type. Scoring of stain expression was performed by ImageJ (National Institutes of Health, Bethesda, MD) analysis using the threshold method and was expressed in percent area/high power field. Clinicopathological correlations were analyzed. All the 27 collected LTGCT cases were located in the small joints of patients' hands. Cases with solitary LGTCTs constituted 55.6%(n = 15), while 44.4% (n = 12) had multipleLTGCTs related to one affected site/case (e.g., multiple tumors in one finger). PPARγ was expressed in the cytoplasm of mononuclear and multinucleated tumor cells and foamy histiocytes, while P53 expression was mainly in mononuclear cells' nuclei. PPARγ significantly correlated with P53 expression (r = 0.9 and P = 0.000). PPARγ (r = 0.4 and P = 0.02) and P53 (r = 0.5 and P = 0.01) were positively correlated with tumor size. Only P53 expression was positively correlated with tumor multiplicity (r = 0.4 and P = 0.03). Using the receiver operating characteristic curve test, the P53 cutoff score detecting the multiplicity of TGCTs was ≥20.5%, with a 75% sensitivity and 80% specificity. PPARγ and P53 have a significant role in LTGCT growth, while P53 plays a role in tumor multiplicity. They can be possible targets in LTGCTs unfit for excision.

An analysis of the influencing factors of false negative autoantibodies in patients with non-small cell lung cancer.

To analyze the clinical significance of seven autoantibodies (P53, PGP9.5, SOX2, GAGE7, GBU4-5, MAGE, and CAGE) in patients with non-small cell lung cancer (NSCLC) and the factors that influence false-negative results. Seven autoantibodies were measured in the serum of 502 patients with non-small cell lung cancer (NSCLC) using ELISA, and their correlations with age, sex, smoking history, pathological type, clinical stage, and PD-L1 gene expression were analyzed. The clinicopathological data of the false-negative and positive groups for the seven autoantibodies were compared to determine the influencing factors. P53 antibody expression level was correlated with lobulation sign, PGP9.5 antibody expression level with sex and vascular convergence; SOX2 antibody expression level with pathological type, clinical stage, and enlarged lymph nodes; and MAGE antibody expression level with the pathological type (P<0.05). False-negative autoantibodies are prone to occur in lung cancer patients with ground-glass nodules, no enlarged lymph nodes, no vascular convergence, and PD-L1 gene expression <1% (P <0.05). Detection of seven autoantibodies was clinically significant in patients with NSCLC. However, poor sensitivity should be considered in clinical diagnoses to prevent missed diagnoses.

Abstract PO5-24-08: Differential exploitation of Cation Transport Regulator homolog 1 (CHAC1) by Wild-type and mutant p53

Abstract Background: Cancer cells are constantly exposed to harsh conditions like nutrient deprivation, hypoxia, and calcium imbalance leading to the induction of UPR. In its early phase, UPR aims to restore homeostasis while prolonged stress leads to induction of apoptosis. Thus, it is not surprising to observe that expression of the UPR components has been reported to both promote as well as suppress tumorigenesis. Studies have shown that Cation transport regulator homolog 1 (CHAC1) plays a dual role in cancer progression. The objective of the present study is to investigate the p53 mediated regulation of CHAC1 in breast cancer. Methods: We initially subjected a breast cancer tissue microarray (TMA) to immunohistochemistry (IHC) with p53 and CHAC1 specific antibody. We further did in vitro experiments like western blotting, qRT-PCR to see the expression of CHAC1 when wild type (WT) p53 was either induced using camptothecin (CPT) and Nutlin-3 in WT p53 expressing breast cancer cells or by the ectopic WT and mutant p53 transfection in null p53 breast cancer cells (MDA-MB-157). The Chromatin immunoprecipitation (ChIP) assay was done to find a potential binding site of p53 on CHAC1 promoter. Further, in vitro study was done to elucidate a potential role of CHAC1 in cell proliferation. Results: The IHC staining analysis revealed that there was no significant difference in the CHAC1 expression between high and low p53 staining tissue cores as high CHAC1 staining was observed in both cases. Further, in vitro analysis reinforced the findings of CHAC1 in TMAs as cell line studies showed that both forms of p53 had enhancing effect on CHAC1 levels. Upon induction of WT p53 and/or ectopic transfection of WT and mutant p53, we observed that CHAC1 levels were upregulated in a dose dependent manner. ChIP assay revealed that while WT p53 occupies the promoter region of the CHAC1 gene to induce its expression, mutant p53 may be inducing CHAC1 expression through an unknown mediator. These observations provide the basis that CHAC1 may be a novel transcriptional target of p53. Ectopic transfection of WT and mutant 53 showed opposite effect on cellular proliferation as evident from BrdU cellular proliferation assay in MDA-MB-157 cells. Further, we showed that CHAC1 enhanced breast cancer cell proliferation possibly via upregulation of PI3K/Akt/mTOR pathway and may likely be a player in angiogenesis as shown by in vitro angiogenesis assay. Conclusion: Taken together, the data from present study suggests that the effect of CHAC1 on cellular proliferation was associated with the status of p53 in breast cancer cells. The results suggest a plausible explanation for the differential behavior of CHAC1 in tumorigenesis. Citation Format: Vikrant Mehta, Harish Chander. Differential exploitation of Cation Transport Regulator homolog 1 (CHAC1) by Wild-type and mutant p53 [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-24-08.

Clinical application of serum seven tumour-associated autoantibodies in patients with pulmonary nodules

BackgroundThe incidence of pulmonary nodules is increasing because of the promotion and popularisation of low-dose computed tomography (LDCT) screening for populations with suspected lung cancer. However, a high rate of false positives and concerns regarding the radiation-related cancer risk of repeated CT scanning remain major obstacles to its wide application. This study aimed to investigate the clinical value of seven tumour-associated autoantibodies (7-TAAbs) in the differentiation of malignant pulmonary tumours from benign ones and the early detection of lung cancer in routine clinical practice. MethodsWe included 377 patients who underwent both the 7-TAAbs panel test and LDCT screening, and were diagnosed with pulmonary nodules using LDCT. An enzyme-linked immunosorbent assay (ELISA) was used to measure the serum levels antibodies for P53, PGP9.5, SOX2, GAGE7, GBU4-5, CAGE, and MAGE-A1. The relationships between the positive rates of the 7-TAAbs and the patient sex, and age, and the number, size, and composition of pulmonary nodules were analysed. We then statistically evaluated the clinical application value. ResultsThe positive rates of the 7-TAAbs did not correlate with sex, age, number, size, or composition of pulmonary nodules. The serum antibody level of GBU4-5 in patients with pulmonary nodules tended to increase with age; the serum antibody level of SOX2 tended to increase with nodule size and was the highest among patients with mixed ground-glass opacity (mGGO) nodules. The antibody positive rate for CAGE in female patients with pulmonary nodules was significantly higher than that in male patients (P < 0.05). The positive rate of GBU4-5 antibody in patients aged 60 years and above was higher than that in younger patients (P < 0.05). The positive rate of GAGE7 antibody in patients with pulmonary nodules sized 8–20 mm was also significantly higher than that in patients with pulmonary nodules sized less than 8 mm (P < 0.01). Significant differences were observed in the GAGE7 antibody levels of patients with pulmonary nodules of different compositions (P < 0.01). The positive rate of the 7-TAAbs panel test in patients with lung cancer was significantly higher than in patients with pulmonary nodules (P < 0.01). Serum levels of P53, SOX2, GBU4-5, and MAGE-A1 antibodies were significantly higher in patients with lung cancer than in those with pulmonary nodules (P < 0.05). ConclusionThe low positive rates of serum 7-TAAbs in patients with lung cancer and pulmonary nodules may be related to different case selection, population differences, geographical differences, different degrees of progression, and detection methods. The combined detection of 7-TAAbs has some clinical value for screening and early detection of lung cancer.

The Relationship of Microsatellite Instability with BRAF and p53 Mutations and Histopathological Parameters in Colorectal Adenocarcinoma.

This study aims to elucidate the associations between microsatellite instability (MSI) status, BRAF mutation, and p53 reactions with pathological parameters and survival outcomes in colorectal carcinoma. MutL homologous 1 (MLH1), Postmeiotic segregation increased 2 (PMS2), MutS homologous 2 (MSH2), MutS homologous 6 (MSH6), BRAF, and p53 antibodies were performed on 130 adenocarcinoma samples, including 65 from the right colon and 65 from the left colon. The relationships of MSI status with BRAF mutation, p53 reaction, clinical and pathological parameters, and survival times were statistically analyzed. A statistically significant relationship was found between MSI and right colon localization, tumor size, histological grade, intraepithelial tumor-infiltrating lymphocytes, Crohn-like lymphocytic reaction, expansive growth pattern, and BRAF mutation (p < 0.05). No significant correlation was found between MSI status and the disease-free or overall survival times (p > 0.05). In colorectal adenocarcinoma, MSI and BRAF mutation are associated with parameters, indicating the host immune response and prognostic histopathological parameters, including tumor size and histological grade. The evaluation of MSI status and BRAF mutation can be particularly informative for predicting the prognosis and guiding the treatment management in poorly differentiated colorectal adenocarcinoma. Understanding the mechanisms of molecular carcinogenesis in colorectal carcinoma and organizing treatment algorithms based on molecular foundations will increase the success of the treatment.

Role of P63 in Benign and Malignant Lesions of Breast

Introduction: Breast carcinoma is leading cause of cancer death in women. Breast lesions constitute heterogeneous group of diseases with wide variety of etiologies ranging from inflammatory-benign- malignant lesions. There are several reported markers for immunohistochemical detection of myoepithelial cells. Smooth muscle specific proteins, such as smooth muscle actin, smooth muscle myosin heavy chain, calponin and h-caldesmon are used to highlight myoepithelium. p63 antibody is myoepithelial cell marker that selectively stains nuclei. It is negative in stromal, myofibroblastic and adipocytic cells.Aims and Objectives: The aim of this study was to establish role of p63 expression in distinguishing benign breast lesions, premalignant lesions and malignant tumors of breast.Materials and Methods: 30 cases were selected from core biopsy, lumpectomy and mastectomy specimens ofbreast received at department of Pathology, Chalmeda Anand Rao Institute of Medical Sciences during the period of January 2021 to December 2021 and were studied prospectively. All specimens were processed according to CAP protocol and reported . Immunohistochemistry was performed to determine p63 expression in those specimens. p63 expression was evaluated as continuous positive/discontinuous positive/negative.Ethical Approval: This study was reviewed and approved by institute ethics committee, CAIMS, Karimnagar.Results: Among total 30 cases, 18 cases (60%) were benign lesions and all were positive for p63 expression. 3 cases (9.99%) were premalignant and were least positive for p63 expression. All malignant cases 9 cases (29.99%) were negative for p63 expression.Conclusion: The Positive correlation was seen between histomorphological features and p63 scoring in all the lesions, So p63 is good Immunohistochemical marker for evaluating breast lesions.

Assessing the Diagnostic Impact of p53, p16, Retinoblastoma and bcl-2 Proteins in Human Papillomavirus-associated Squamous Cell Carcinoma of the Cervix

Abstract BACKGROUND: Cervical cancer is the third-most prevalent disease among women and is mostly associated with the human papillomavirus with a significant number of mortalities. It accounts for more than 95% of cases diagnosed late. The aim of the study was to investigate the involvement of tumor protein 53 (P53), tumor suppressor protein 16 (P16), retinoblastoma (Rb), and B-cell lymphoma 2 (BCL-2) as diagnostic factors in tumor suppression in cervical lesions. A case–control study that used 160 cervical tissue blocks selected from the pathology archives. All blocks used are confirmed cases of cervical samples. METHODS: Hematoxylin and eosin staining and immunohistochemical technique were used to treat samples with the matching antibodies for P53, P16, Rb, and BCL-2 expression as described by Camacho-Urkaray. Analysis of the data obtained from the study was carried out using photomicrographs, charts, graphs, and tables. RESULTS: A positive association between the expression levels of P53, P16, Rb, and BCL-2 with the progression of cervical lesions. It was revealed that P53 had a higher diagnostic effect for squamous cell carcinoma of the cervix, followed by P16, Rb, and BCL-2, respectively. CONCLUSION: The research shows that the P53, P16, Rb, and BCL-2 proteins are expressed in malignant lesions with moderate-to-severe intensities accordingly and are also closely related to the progression of cervical oncogenesis.

Prognostic significance of tumor suppressor protein p53 in prostate cancer.

The p53 gene mutation is one of the most common genetic alterations in many cancers. In prostate cancer (PCa), it has been associated with a poor prognosis, tumor progression and aggressiveness. P53 mutation induces an abnormal protein expression in related tissues. This study aimed to assess p53 expression using immunohistochemistry in PCa and to discuss its prognostic value. We have retrospectively collected all cases of PCa diagnosed in our pathology department between 2012 and 2022. An automatized immunohistochemical analysis was performed using monoclonal p53 antibody. For each case, we assessed the proportion of positive cells and the intensity of staining. P53 expression was considered abnormal when it was totally negative or overexpressed (>=50% of positive cells). Twenty-four cases have been selected. Abnormal p53 expression was found in 42% of cases (P53 was overexpressed in 6cases and totally negative in 4 cases). Mean age of patients with p53 abnormal expression was 70years old. Patients with p53 abnormal expression had Gleason score >7 in 5 cases, ISUP grade >2 in 3 cases, peri-neural invasion in 8cases, capsule invasion in 9cases. All patients with p53 overexpression developed androgen resistance (p<0.01). An aberrant expression profile of the p53 protein was observed in 42% of cases, and a statistically significant association was found with androgen resistance. Our results suggest a potential prognostic role of p53 in PCa.

Significance of RCC2, Rac1 and p53 Expression in Breast Infiltrating Ductal Carcinoma; An Immunohistochemical Study.

The regulator of chromosome condensation 2 (RCC2) and RAS-related C3 botulinum toxin substrate 1 (Rac1) have been implicated in the promotion of breast cancer cell proliferation and migration. The signaling pathway involving p53/RCC2/Rac1 has been proposed to contribute to the regulation of colon cancer metastasis. However, until now, this pathway has not been thoroughly investigated in breast cancer. This study seeks to explore the influence of immunohistochemical expression and the correlation among RCC2, Rac1, and p53 in breast infiltrating ductal carcinoma (IDC). Immunostaining was performed on 120 breast IDC specimens using RCC2, Rac1, and p53 antibodies. Statistical analyses were conducted to examine the correlations between these antibodies. A Positive expression of RCC2, Rac1, and p53 was observed in 116 (96.7%), 120 (100%), and 33 (27.5%) of the breast cancer cases, respectively. RCC2, Rac1, and p53 demonstrated association with poor prognostic parameters such as frequent mitoses, high Ki-67 status, positive lymphovascular invasion (LVI), and advanced tumor stage. A highly significant direct correlation was found between each immunohistochemical marker and the other two markers. Shorter overall survival was linked to multifocal tumors (P=0.017), advanced tumor stage (T3) (P=0.010), Luminal B subtype (P=0.015), progressive disease (P=0.003), positive Her2neu status (P=0.008), and metastasis to distant organs (P<0.001). However, RCC2, Rac1, and p53 did not exhibit a significant association with overall survival. The high expression levels of RCC2, Rac1, and p53 in breast IDC suggest their potential role in tumor behavior. The association of RCC2 and Rac1 with poor prognostic parameters may serve as predictive indicators for aggressive tumors, thus implying that targeted therapy could be beneficial in the treatment of breast cancer.

Serum NY-ESO-1 antibody as a predictive biomarker for postoperative recurrence of gastric cancer: a multicenter prospective observational study

BackgroundNo reliable marker has been identified to predict postoperative recurrence of gastric cancer. We designed a clinical trial to investigate the utility of serum NY-ESO-1 antibody responses as a predictive marker for postoperative recurrence in gastric cancer.MethodsA multicenter prospective study was conducted between 2012 and 2021. Patients with resectable cT3-4 gastric cancer were included. Postoperative NY-ESO-1 and p53 antibody responses were serially evaluated every 3 months for 1 year in patients with positive preoperative antibody responses. The recurrence rate was assessed by the positivity of antibody responses at 3 and 12 months postoperatively.ResultsAmong 1001 patients, preoperative NY-ESO-1 and p53 antibody responses were positive in 12.6% and 18.1% of patients, respectively. NY-ESO-1 antibody responses became negative postoperatively in non-recurrent patients (negativity rates; 45% and 78% at 3 and 12 months, respectively), but remained positive in recurrent patients (negativity rates; 9% and 8%, respectively). p53 antibody responses remained positive in non-recurrent patients. In multivariate analysis, NY-ESO-1 antibody positivity at 3 months (P < 0.03) and 12 months (P < 0.001) were independent prognostic factors for a shorter recurrence-free interval.ConclusionsSerum NY-ESO-1 antibodies may be a useful predictive marker for postoperative recurrence in gastric cancer.Clinical trial registrationUMIN000007925.

Epidemiology of Pathogenic Retroviruses and Domestic Cat Hepadnavirus in Community and Client-Owned Cats in Hong Kong.

Understanding the local epidemiology of feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV) in Hong Kong will inform retrovirus prevention strategies. Domestic cat hepadnavirus (DCH), a novel hepatitis-B-like virus, is commonly detected among client-owned cats in Hong Kong, but community cats have not been studied. The aims of this study were to investigate the frequency and potential risk factors for (i) FeLV and FIV among community and client-owned cats and (ii) perform molecular detection of DCH among community cats in Hong Kong. Blood samples from 713 cats were obtained from client-owned (n = 415, residual diagnostic) and community cats (n = 298, at trap-neuter-return). Point-of-care (POC) testing for FeLV antigen and feline immunodeficiency virus (FIV) anti-p15 and p24 antibodies was performed. FeLV-positive samples were progressed to p27 sandwich enzyme-linked immunosorbent assay. Whole blood DNA was tested with qPCRs for FeLV U3 and gag, and nested PCRs where additional information was required. DCH qPCR was performed on a subset of community cats (n = 193). A single, regressive, FeLV infection was detected in a client-owned cat (1/415 FeLV U3 qPCR positive, 0.2%, 95% CI 0.0-1.3%). Five/415 client-owned cats tested presumably false FeLV-antigen positive (qPCR negative). No markers of FeLV infection were detected in community cats (0/298; 0%). FIV seroprevalence was much higher in community cats (46/298, 15.4%) than in client-owned cats (13/415, 3.1%) (p < 0.001). Mixed breed was a risk factor for FIV infection in client-owned cats. Neither sex nor age were associated with FIV infection. DCH DNA was detected in 34/193 (17.6%) community cats (median viral load 6.32 × 103 copies/reaction). FeLV infection is rare in Hong Kong, negatively impacting the positive predictive value of diagnostic tests. FeLV-antigen testing remains the screening test of choice, but confirmation of a positive result using FeLV qPCR is essential. FIV infection is common in community cats and the absence of a sex predisposition, seen previously in cats managed similarly, raises questions about virus-transmission dynamics in these groups. DCH infection is very common in Hong Kong, both in client-owned and community cats, highlighting the importance of understanding the pathogenic potential of this virus for cats.

Qualification of a multiplexed tissue imaging assay and detection of novel patterns of HER2 heterogeneity in breast cancer.

Emerging data suggests that HER2 intratumoral heterogeneity (ITH) is associated with therapy resistance, highlighting the need for new strategies to assess HER2 ITH. A promising approach is leveraging multiplexed tissue analysis techniques such as cyclic immunofluorescence (CyCIF), which enable visualization and quantification of 10-60 antigens at single-cell resolution from individual tissue sections. In this study, we qualified a breast cancer-specific antibody panel, including HER2, ER, and PR, for multiplexed tissue imaging. We then compared the performance of these antibodies against established clinical standards using pixel-, cell- and tissue-level analyses, utilizing 866 tissue cores (representing 294 patients). To ensure reliability, the CyCIF antibodies were qualified against HER2 immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) data from the same samples. Our findings demonstrate the successful qualification of a breast cancer antibody panel for CyCIF, showing high concordance with established clinical antibodies. Subsequently, we employed the qualified antibodies, along with antibodies for CD45, CD68, PD-L1, p53, Ki67, pRB, and AR, to characterize 567 HER2+ invasive breast cancer samples from 189 patients. Through single-cell analysis, we identified four distinct cell clusters within HER2+ breast cancer exhibiting heterogeneous HER2 expression. Furthermore, these clusters displayed variations in ER, PR, p53, AR, and PD-L1 expression. To quantify the extent of heterogeneity, we calculated heterogeneity scores based on the diversity among these clusters. Our analysis revealed expression patterns that are relevant to breast cancer biology, with correlations to HER2 ITH and potential relevance to clinical outcomes.

P53 Expression in Gallbladder Lesions: A Cross-sectional Study from a Tertiary Care Centre in Northern India

Introduction: Gallbladder lesions comprise inflammatory, benign, pre-malignant, and malignant lesions. The progression of benign lesions into malignant ones involves a complex process. The p53 gene is commonly disrupted in carcinogenesis. Malignant lesions may exhibit p53 overexpression compared to benign and inflammatory lesions. Aim: To investigate the distribution of gallbladder lesions and the expression of the p53 nuclear protein in these lesions. Materials and Methods: A cross-sectional study was conducted at the Department of Pathology, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, from June 2020 to December 2022. A total of 249 specimens of gallbladder lesions, including congenital, inflammatory, benign, pre-malignant, and malignant lesions, were included. All samples underwent Haematoxylin &amp; Eosin(H&amp;E) staining and Immunohistochemistry (IHC) with p53 antibody using the peroxidase-antiperoxidase method. The association of P53 expression with histopathological diagnosis was analysed using Fisher’s Exact test. The final analysis was performed using Statistical Package for Social Sciences (SPSS) software, version 25.0. A p-value &lt;0.05 was considered statistically significant. Results: Out of 249 specimens, there were 217 (87.14%) inflammatory lesions, 9 (3.6%) benign lesions, 2 (0.8%) premalignant lesions, and 21 (9.26%) malignant lesions. The main inflammatory lesions were Chronic Cholecystitis (CC) with 132 cases (60.83%) and CC with cholesterosis with 36 cases (16.59%). The most common pre-malignant lesion was choledochal cyst with 3 cases (3.33%). Benign tumours (leiomyoma) were present in 2 (0.8%) patients. Among the 21 (8.46%) malignant tumours, 4 (19.05%) were moderately differentiated adenocarcinoma, 13 (61.9%) were poorly differentiated adenocarcinoma, and 4 (19.05%) were welldifferentiated adenocarcinoma. P53 overexpression was significantly higher in patients with malignant tumours (9 cases, 42.86%) compared to inflammatory lesions (26 cases, 11.98%), benign lesions (0 cases, 0%), and pre-malignant lesions (0 cases, 0%) (p=0.003). Conclusion: Gallbladder lesions exhibit a wide range of histopathological presentations. Inflammatory lesions are the most common, followed by pre-malignant and malignant lesions. P53 can serve as a novel marker for differentiating inflammatory lesions from malignant lesions in the gallbladder.

P53 Expression in Gallbladder Lesions: A Cross-sectional Study from a Tertiary Care Centre in Northern India

Introduction: Gallbladder lesions comprise inflammatory, benign, pre-malignant, and malignant lesions. The progression of benign lesions into malignant ones involves a complex process. The p53 gene is commonly disrupted in carcinogenesis. Malignant lesions may exhibit p53 overexpression compared to benign and inflammatory lesions. Aim: To investigate the distribution of gallbladder lesions and the expression of the p53 nuclear protein in these lesions. Materials and Methods: A cross-sectional study was conducted at the Department of Pathology, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, from June 2020 to December 2022. A total of 249 specimens of gallbladder lesions, including congenital, inflammatory, benign, pre-malignant, and malignant lesions, were included. All samples underwent Haematoxylin &amp; Eosin(H&amp;E) staining and Immunohistochemistry (IHC) with p53 antibody using the peroxidase-antiperoxidase method. The association of P53 expression with histopathological diagnosis was analysed using Fisher’s Exact test. The final analysis was performed using Statistical Package for Social Sciences (SPSS) software, version 25.0. A p-value &lt;0.05 was considered statistically significant. Results: Out of 249 specimens, there were 217 (87.14%) inflammatory lesions, 9 (3.6%) benign lesions, 2 (0.8%) premalignant lesions, and 21 (9.26%) malignant lesions. The main inflammatory lesions were Chronic Cholecystitis (CC) with 132 cases (60.83%) and CC with cholesterosis with 36 cases (16.59%). The most common pre-malignant lesion was choledochal cyst with 3 cases (3.33%). Benign tumours (leiomyoma) were present in 2 (0.8%) patients. Among the 21 (8.46%) malignant tumours, 4 (19.05%) were moderately differentiated adenocarcinoma, 13 (61.9%) were poorly differentiated adenocarcinoma, and 4 (19.05%) were well-differentiated adenocarcinoma. P53 overexpression was significantly higher in patients with malignant tumours (9 cases, 42.86%) compared to inflammatory lesions (26 cases, 11.98%), benign lesions (0 cases, 0%), and pre-malignant lesions (0 cases, 0%) (p=0.003). Conclusion: Gallbladder lesions exhibit a wide range of histopathological presentations. Inflammatory lesions are the most common, followed by pre-malignant and malignant lesions. P53 can serve as a novel marker for differentiating inflammatory lesions from malignant lesions in the gallbladder.

Domestic Cat Hepadnavirus and Pathogenic Retroviruses; A Sero-Molecular Survey of Cats in Santiago, Chile.

Cat ownership is common in Chile, but data on the regional prevalence of infectious agents are limited. A sero-molecular survey of 120 client- or shelter-owned domestic cats in greater Santiago was performed. Whole blood DNA was tested for the novel hepatitis-B-like virus, domestic cat hepadnavirus (DCH) by conventional PCR (cPCR) and quantitative PCR (qPCR), and for feline leukaemia virus (FeLV) by qPCR. Point-of-care serology for FeLV p27 antigen and antibodies recognising feline immunodeficiency virus (FIV) p15 and p24 was performed. DCH DNA was detected in the serum of 2/120 cats (1.67%). Sequencing and phylogenetic analysis showed that the DCH detected in Chile occupies a position outside the main clustering of DCH in the near-complete genome tree. Progressive (antigen-positive, provirus-positive) and regressive (antigen-negative, provirus-positive) FeLV infections were identified in 6/120 (5%) and 9/120 (7.5%) of cats. A total of 2/120 (1.7%) cats had dual FeLV/FIV infection, and another 2 cats had FIV infection alone. This study shows that the global footprint of DCH includes South America with a low molecular frequency in Chile, similar to that reported in the USA. Progressive FeLV infection is relatively common in urban Chile, and male cats are at greater risk than females. Testing and control measures for pathogenic retroviruses are indicated. The potential impact of FeLV, FIV and DCH on Chile's wildcat species is worthy of further investigation.

Assaying of p53 Autoantibodies in saliva for the detection of oral squamous cell carcinoma. A road not taken.

Autoantibody detection is a promising approach to cancer screening. Serum p53 antibodies have been time tested in various cancers, including oral squamous cell carcinoma (OSCC). This study is aimed to detect and determine the level of p53 autoantibodies (p53-AAbs) in saliva. The association of clinicopathological features among patients with and without OSCC was also explored as a novel method for the detection of autoantibodies. One hundred preoperative saliva samples from patients with histologically confirmed OSCC and a hundred from normal healthy individuals were collected. Anti p53 detection kit assessed levels of salivary p53-AAbs. The cut-off value was 1.3 U/mL by Enzyme-linked immunosorbent assay (ELISA). The p53-AAb levels were expressed in terms of the median and interquartile range (IQR). Fischer's exact test and Chi-square test were used to determine the association with clinicopathological features among patients with OSCC and healthy controls with tobacco consumption habits. Median level of p53-AAb is 0.234 U/mL (IQR 0.18-0.37U/mL) in healthy controls and 0.285U/mL (IQR 0.16-0.58U/mL) in OSCC. p53-AAbs was positive in 15% of 100 patients with OSCC, which was statistically higher (P < 0.001) among OSCC, and controls were negative for p53-AAb. No significant correlation of p53-AAbs with the patient's age, gender, site, clinical staging (TNM), and pathologic grade was observed. However, a significant association was seen between the node involvement and salivary p53-AAbs. Salivary p53-AAb positivity was seen in a higher proportion in OSCC patients than in healthy controls with tobacco consumption, and the levels did differ significantly among OSCC and healthy controls.