P53 Gene Mutations Research Articles

TP53 Allelic State in Myelodysplastic Syndromes with 5q Deletion

Introduction: Around 10% of de novo MDS harbor mutations in tumor protein p53 (TP53) gene. Recently, it has been shown that two-thirds of patients with MDS and mutated TP53 gene exhibit multi-hit mutations of TP53, this being associated with poor clinical features and outcome. Taking into consideration that MDS with isolated deletion of chromosome 5 (MDS-del5q) are particularly enriched in TP53 mutations (around 20% exhibit TP53 aberrations), we decided to analyze the TP53 allelic state in patients with MDS-del(5q). Methods: Patients from seven centers belonging to the Spanish Group of MDS (GESMD) and diagnosed with MDS-del5q according to the WHO 2017 classification were included. Therapy related MDS-del5q, as well as patients on disease modifying therapy prior the genetic analysis were excluded. Clinical characteristics and laboratory data were collected at the moment of diagnosis. Genetic profiling included conventional G-banding analyses, FISH for TP53 deletion, next-generation sequencing (NGS) analysis of a panel of 27 genes recurrently mutated in MDS (ASXL1, CALR, CBL, CEBPA, CSF3R, DNMT3A, ETV6, EZH2, FLT3, IDH1, IDH2, JAK2, KIT, KRAS, MPL, NPM1, NRAS, PTPN11, RUNX1, SETBP1, SF3B1, SRSF2, TET2, TP53, U2AF1, WT1, ZRSR2), and Sanger sequencing. Variant filtering and categorization were performed according to the Spanish Guidelines (Palomo et al., 2019). Based on TP53 mutations and allelic imbalances in chromosome 17p, patients were classified as follows (Bernard et al, 2020): 1) TP53 wild-type (TP53-wt) when no TP53 mutations were found; 2) TP53 monoallelic (TP53-monoallelic) when only 1 mutation was present; and 3) TP53 multi-hit (TP53-multihit) when multiple mutations or mutation(s) and concomitant deletion or copy number neutral loss of heterozygosity (LOH) were identified. Statistical analysis was performed by R (4.2.0). Results: We included 140 MDS-del(5q). Patient's characteristics are detailed in Table 1. Median overall survival (OS) was 96.7 months. Conventional cytogenetic analysis and/or FISH were performed in all cases. NGS was done in 76% (n=106), whereas in the remaining 24% (n=34) analysis of TP53, TET2, CBL and IDH1/2 was performed by Sanger sequencing. Eighty-six per cent (n=120) of patients were TP53-wt, and 14% (n=20) presented TP53 abnormalities: 12% (n=17) TP53-monoallelic and, interestingly, only 2% (n=3) TP53-multihit (Figure 1). In most TP53-monoallelic patients (n=10/17), TP53 mutation was detected as a single genetic event, while the most frequent concomitant mutation among the remaining MDS was DNMT3A (n=3). All TP53-multihit cases harbored two TP53 mutations, but no deletions or LOH in 17p were detected. In 2 out of these 3 patients, no other concomitant mutations were detected. As per the general mutational landscape of the MDS-del(5q) TP53-wt patients, the most frequently affected genes were SF3B1 (15%), DNMT3A (14%), TET2 (13%), ASXL1 (8%), JAK2 (4%), SETBP1 (2%) and CBL (2%). Finally, median OS was 96.7 months for MDS-del(5q) TP53-wt, 62.8 months for MDS-del(5q) TP53-monoallelic, and 56.9 months for MDS-del(5q) TP53-multihit; p= 0.3, with a trend for a worse OS of TP53-monoallelic compared with TP53-wt (HR, 0.5; p=0.106). Conclusions: This study shows that, as opposite to other MDS subgroups, the presence of multi-hit TP53 status is uncommon in patients with MDS-del5q. Larger series are currently collected to further ascertain the prognostic impact of TP53 aberrations in patients with MDS-del(5q). Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

The Prognostic Value of TP53 Mutations in Adult Acute Myeloid Leukemia: A Meta-Analysis

Objective: Mutations of the tumor protein p53 (TP53) gene were considered to be associated with an unfavorable prognosis in acute myeloid leukemia (AML). This meta-analysis aimed to systematically elucidate the prognostic value of TP53 mutation in adult patients with AML. Method: A comprehensive literature search was conducted for eligible studies published before August 2021. The primary endpoint was overall survival (OS). Pooled hazard ratios (HRs) and their 95% confidence intervals (CIs) were calculated for prognostic parameters. Subgroup analyses based on intensive treatment were performed. Results: Thirty-two studies with 7,062 patients were included. As compared to wild-type carriers, AML patients with TP53 mutations had significantly shorter OS (HR: 2.40, 95% CI: 2.16–2.67, I²: 46.6%). Similar results were found in DFS (HR: 2.87, 95% CI: 1.88–4.38), EFS (HR: 2.56, 95% CI: 1.97–3.31), and RFS (HR: 2.40, 95% CI: 1.79–3.22). Mutant TP53 predicted inferior OS (HR: 2.77, 95% CI: 2.41–3.18) in the intensively treated AML subgroup, compared with the non-intensively treated group (HR: 1.89, 95% CI: 1.58–2.26). Among intensively-treated AML patients, the age of 65 did not affect the prognostic value of TP53 mutations. Besides, TP53 mutation was also strongly associated with an elevated risk of adverse cytogenetics, which conferred a dismal OS in AML patients (HR: 2.03, 95% CI: 1.74–2.37). Conclusion: TP53 mutation exhibits a promising potential for discriminating AML patients with a worse prognosis, thus being capable of serving as a novel tool for prognostication and therapeutic decision-making in the management of AML.

Nuclear Proteomics of Induced Leukemia Cell Differentiation.

Studies of induced granulocytic differentiation help to reveal molecular mechanisms of cell maturation. The nuclear proteome represents a rich source of regulatory molecules, including transcription factors (TFs). It is important to have an understanding of molecular perturbations at the early stages of the differentiation processes. By applying the proteomic quantitative profiling using isobaric labeling, we found that the contents of 214, 319, 376, 426, and 391 proteins were altered at 3, 6, 9, 12, and 72 h, respectively, compared to 0 h in the HL-60 cell nuclear fraction under all-trans-retinoid acid (ATRA) treatment. From 1860 identified nuclear proteins, 231 proteins were annotated as proteins with transcription factor (TF) activity. Six TFs (RREB1, SRCAP, CCDC124, TRIM24, BRD7, and BUD31) were downregulated and three TFs EWSR1, ENO1, and FUS were upregulated at early time points (3–12 h) after ATRA treatment. Bioinformatic annotation indicates involvement of the HL-60 nuclear proteome in DNA damage recognition in the RUNX1-triggered pathway, and in the p53-regulation pathway. By applying scheduled multiple reaction monitoring using stable isotopically labeled peptide standards (MRM/SIS), we found a persistent increase in the content of the following proteins: PRAM1, CEPBP, RBPJ, and HIC1 in the HL-60 cell nuclear fraction during ATRA-induced granulocytic differentiation. In the case of STAT1, CASP3, PARP1, and PRKDC proteins, a transient increase in their content was observed at early time points (3–12 h) after the ATRA treatment. Obtained data on nuclear proteome composition and dynamics during granulocytic differentiation could be beneficial for the development of new treatment approaches for leukemias with the mutated p53 gene.

Cancer Classification Based on the Features of Itemset Sequence Pattern of TP53 Protein Code Using Deep Miden - KNN

Cancer is a disease that is still difficult to identify up to today. One of the causes of cancer is genetic modification that because of mutations in p53 gene. Healthy cells have a p53 wild type protein (normal) that is able to manage DNA separation. If DNA mutates, it will be difficult to detect cancer because the composition of the protein has changed. Bioinformatics is a combination of biology and information engineering (TI) that is utilized to manage data. One of the applications of data mining in bioinformatics is the development of pharmaceutical and medical industries. Data mining classification can use variety of methods including K-Nearest Neighbor (KNN), C45, ID3, and several other methods. One of the most reliable data classification methods is KNN. In this study, the development used two algorithms. The first was with the modification of the k-fold method, which divided two data into training data and test data, in which test-1 data and test-2 data were made into slices. The second was by a method for selecting an itemset sequence pattern that had the largest Gain Information, either 2 itemsets, 3 itemsets, and so on (Deep Miden). The best accuracy result of 96.00% was obtained through the process of computation testing in the server based on variations in terms of the number of patterns of Deep Miden itemset sequences and several k values on KNN classification method.

Importance of p53, bcl-2 genes in uterine body cancer and their role in prediction

Uterine body cancer (UBC) makes up 7.1% of malignant tumors in women and ranks 6th in the structure of the incidence of malignant tumors in women in the world after breast cancer, cervical cancer, colorectal cancer, lung and thyroid cancer. In developed countries, it is the most common malignant tumor of the female genital organs. The study included 105 patients with a diagnosis of stage I uterine body cancer, the patients were divided into 2 groups: I - the main group consists of 60 patients who received preoperative brachytherapy (Total focal dose (TFD) = 16-20Gy). Control group II consisted of 45 patients who, after curettage of the uterine cavity, were immediately operated on in the volume of extirpation of the uterus with appendages and routinely received combined radiation therapy: from distance gamma therapy (DGT) TFD = 44 Gy, from brachytherapy TFD = 20 Gy. All biological materials obtained during curettage of the uterine cavity and as a result of surgery in both groups were subjected to immunohistochemistry. The mutant p53 gene and the apoptosis regulator bcl-2 were studied by immunohistochemical method.

Analysis of Common Mutation of P53 Gene in Male with Lung Cancer in Mosul City

TP53 gene plays a critical role in the follow-up of different cancer cases, including diagnosis and follow-up treatment and the mutation in the P53 gene. It harms the encoded P53 protein and the less function of P53 protein in different types of cancer due to the mutation in the TP53 gene. P53 protein has many mechanisms to eliminate cancer cells, like apoptosis, cell cycle arrest, and DNA repair. This study aims to detect the abnormality change in the sequence of P53 mutation and the correlation with cancer in Mosul city DNA extraction depends on the manual description from blood, the Pro72Arg in exon 4 G\C allele mutation measurement by ARMS-PCR, and the analysis of common mutation in Exon 3,4,5 by DNA sequencing technique. The result of this study shows the observation of different genotypes and allelic frequencies of Pro72Arg polymorphism in exon 4. It was the presence of wild-type genotype CC (pro\pro) 12%, hetero genotype CG (pro\arg) 72% and mutant genotype GG (arg\arg) 16% in patients with Lung cancer. While in healthy people, the wild genotype CC was 26 hetero genotype CG 66 and mutant genotype GG 8%. As for the result of DNA sequencing, this research doesn't find any change in the nucleotide of Exon 5 for the P53 gene of the case study. At the same time, the DNA sequence result of Exon 6 for the P53 gene in patients finds some changes in the nucleotide sequence with sequence. According to this study, the observation of different genotypes and allelic frequency of Pro72Arg polymorphism in exon 4 for the P53 gene present significant variation between patients with lung cancer and healthy group male with Lung cancer Keywords: P53 gene, ARMS-PCR, Mutation, SNP, Lung cancer, Exon.

Role of TP53 Gene Mutations in the Pathogenesis of Colorectal Carcinoma

Colorectal cancer (CRC) is the third most commonly diagnosed cancer in both men and women in the world. The underlying molecular mechanisms that drive colorectal carcinogenesis are not fully known. However, P53 gene mutation, the most reported somatic mutation, is observed in about 50% of colorectal cancer patients.
 Colorectal carcinoma is multifactorial. TP53 gene, the most novel tumor suppressor gene, acts as a major gatekeeper by preserving the genetic composition of a cell and prevents the oncogenic transformation of a cell. MDM2 and CUL-4A belong to the E3 ubiquitin ligase family, blocks P53 activation, and thus act as an oncogene. TRIM67 also has defective ligase activity, and its mutation is seen in about 80% of colorectal carcinomas. miRNA inhibits the tumor suppressor effect of TP53 and downstream signaling pathways, resulting in carcinogenesis. K RAS, WT1, IGF-1 are other markers of colorectal carcinoma. P53 antibodies produce by colorectal carcinomatous tissue are the markers used for screening and diagnosis.
 P53 mutation drives a phenomenon of colorectal tumorigenesis. It serves as a biomarker, a prognostic factor, and a therapeutic target of colorectal carcinoma. Further studies are strongly recommended to improve the therapeutic approach of colorectal carcinoma.

Study on some clinical features, histopathology and mutations in IDH, P53 genes, mgmt methylation in patients with high-grade glioma

Objectives: To describe some genes' clinical, histopathological and mutational characteristics in patients with high-grade glioma. Subjects and methods: A descriptive study was conducted on 52 high-grade glioma patients who met the research criteria at Vietnam National Cancer Hospital (Tan Trieu campus) from 1st January 2019 to 12th December 2020. Results: The mean age of the study patients was 45.2 ± 14.4; men accounted for the majority (61.5%). The main reason for the patient's admission was headache, hemiplegia, epilepsy... The average Karnofski score of the patient was 68.5 ± 14.7 points. The results of IDH gene mutation show that patients with grade III GCC have a higher positive rate than grade IV, P53 gene mutations occur mainly in grade IV GCC patients, MGMT methylation occurs on 57% of study patients. Conclusion: High-grade glioma is common in men aged over 40. Common clinical symptoms are headache, hemiplegia, and epilepsy. IDH gene mutations are seen in grade III gliomas, P53 gene mutations are common in grade IV gliomas.
 * Keywords: High-grade glioma; IDH gene mutation; P53 gene mutation; MGMT methylation.

The C-terminus of Gain-of-Function Mutant p53 R273H Is Required for Association with PARP1 and Poly-ADP-Ribose.

The C-terminal region of mtp53 confers GOF activity that mediates mtp53-PARP1 and PAR interactions assisting DNA replication, thus implicating new biomarkers for PARP inhibitor therapy.

Proteasomal and autophagy-mediated degradation of mutp53 proteins through mitochondria-targeting aggregation-induced-emission materials

Close to half of human cancers harbor point mutations in the tumor-suppressor p53 gene, giving rise to the cellular accumulation of mutant p53 (mutp53) proteins with novel neomorphic gain-of-function (GOF) properties. The destruction of mutp53 proteins through either autophagic or proteasomal degradation is a viable strategy for the targeted therapy of p53-mutated cancers. Several nanomaterials, including zinc-iron and ZIF-8 nanoparticles (NPs), have been reported to induce the proteasomal degradation of mutp53 proteins. However, how autophagy, the other major cellular degradative pathway, influences NP-induced mutp53 degradation has not been investigated. This article shows that AIE-Mit-TPP, a mitochondria-targeting material with aggregation-induced emission (AIE) characteristics, elicits ubiquitination-dependent proteasomal degradation of a broad range of mutp53 proteins. Meanwhile, AIE-Mit-TPP also induces massive mitochondrial damage and autophagy. The inhibition of autophagy further increases AIE-Mit-TPP-elicited mutp53 degradation, revealing the negative impact of autophagy on AIE-Mit-TPP-induced mutp53 degradation. As expected, the degradation of mutp53 proteins by AIE-Mit-TPP abrogated mutp53-manifested GOF, leading to reductions in cell proliferation and migration and increases in cell cycle arrest and cell death. Consequently, AIE-Mit-TPP inhibited the growth of mutp53 tumors. This paper unravels the interesting interplay between the proteasomal and autophagic degradative pathways and pinpoints the modulation of autophagy as a potential strategy for optimizing NP-induced mutp53 degradation and p53-targeted cancer therapy. Statement of significanceWe have designed three different types of AIE materials: non-targeting (AIE-Br), mitochondria-targeting (AIE-Mit-TPP), lysosome-targeting (AIE-Lyso). Our results proved that mitochondria-targeting AIE material induced degradation of mutp53 proteins via the proteasome degradation pathway and abrogated mutp53-conferred GOF phenotypes. Furthermore, we performed in vitro studies on the effect of the tested materials in mutp53-expressing cancer cells and demonstrated our findings via in vivo investigations in a mouse subcutaneous p53R175H TOV112D ovarian cancer model. Our results confirmed the link between the proteasome pathway and autophagy and thus proposed a strategy of combining AIE-Mit-TPP with autophagy inhibitors for the targeted treatment of mutp53-associated tumors. Finally, we found that AIE-Mit-TPP could induce degradation of a wide-spectrum mutp53 proteins, which makes mitochondria-targeting AIE materials an effective therapeutic strategy for p53-mutated cancers.

Pseudoangiosarcomatous squamous cell carcinoma: a rare subtype of squamous cell carcinoma that needs to be differentiated from angiosarcoma and has a poor prognosis.

This study aimed to investigate the formation mechanism of Pseudoangiosarcoma squamous cell carcinoma (PASCC). The researchers reviewed ten cases of PASCC and summarize their clinical outcomes, pathological morphological traits, immunophenotypes, treatment plans and the corresponding follow-up data. Results showed that the pathological morphology revealed complex reticular structures, where numerous tracts of anastomose, and lacunar structures lined with atypical neoplastic cells, which resembles the histopathological appearance of angiosarcoma. Particularly, we observed pathologic patterns that resemble Sclerosing Epithelioid Fibrosarcoma (or Myxoid Fibrosarcoma) in the patients who suffered a relapse. All cases present negative results for vascular markers (CD31, ERG) and positive results for epithelial markers (CK-pan, p40). The average age of the participants is 60 years old (range: 48-79), relative aged, and there is no significant difference between male and female participants (6 men and 4 women). The locations of neoplasms involve face (n=3), upper limbs (n=1), waist(n=1), cervix uteri (n=1), lungs (n=2), thyroid (n=1), and breasts (n=1). All participants had received clinical follow-ups that range from 4 to 47 months, during which the researchers observed Lymph Node Metastases developed in three participants (out of 10; 30%); Distant Metastases in five participants (out of 10; 50%); two local recurrences at the site of surgical resection; and four deaths due to disease (out of 10; 40%), with 9.5 months estimated median survival time and 9 months mean survival time. It was concluded that PASCC presents the tendency for recurrence and metastasis. Accurate pathological diagnosis and standardized medical procedures are crucial to the treatment of PASCC. Epithelial-Mesenchymal Transformation (EMT) and P53 gene mutation are involved in the formation of PASCC.

The Molecular Associations of Signet-Ring Cell Carcinoma in Colorectum: Meta-Analysis and System Review.

Background: Signet ring cell carcinoma (SC) accounts for 1% of total colorectal cancer (CRC) cases and is associated with aggressive behaviors, such as lymphatic invasion and distant metastases, resulting in poor prognosis. To date, there is still a lack of consensus on the genetic etiology underpinning this cancer subtype. This study aimed to clarify the molecular associations of SC by using meta-analysis and a systematic review. Methods: PubMed, Embase, and Cochrane Library were searched for studies evaluating the KRAS, BRAF, P53 statuses, and microsatellite instability (MSI) in CRC patients with different histological subtypes, including SC. The diagnosis of SC is defined as the signet ring cells comprising ≥50 percent of the tumor mass. By dividing the studies into subgroups based on the composition of control groups, such as classic adenocarcinoma (AC; no SC components) and non-SC (including those with SC components < 50%), the relative risk (RR) of molecular alterations for SC in each study were pooled using a random-effects model. Two reviewers identified trials for inclusion, assessed quality, and extracted data independently. Results: Data from 29 studies consisting of 9366 patients were included in this analysis. SC was associated positively with MSI (RR 1.78, 95% CI 1.34 to 2.37; 95% CI 0.77 to 4.15; p = 0.0005), BRAF mutation (RR 1.99, 95% CI 1.21 to 3.26; 95%CI 0.68 to 5.82; p = 0.0146), and negatively with KRAS mutation (RR 0.48, 95% CI 0.29 to 0.78; 95% CI 0.09 to 2.49; p = 0.0062). No association was found between SC and P53 expression (RR 0.92, 95% CI 0.76 to 1.13; 95%CI 0.61 to 1.39; p = 0.3790). Moreover, it was associated negatively with P53 gene mutations (RR 0.92, 95% CI 0.77 to 1.09; 95% CI 0.46 to 1.82; p = 0.1568), and P53 protein (RR 0.93, 95% CI 0.58 to 1.49; 95% CI 0.40 to 2.17; p = 0.6885). Conclusions: The molecular etiology of SC may be associated with the BRAF and MSI pathways. Its features, such as the high frequency of BRAF mutation, could partly explain its less favorable outcomes and limited effects of traditional chemotherapy.

Abstract 5374: Amentoflavone induces apoptosis and promotes G1 phase cell cycle arrest through regulating p53 pathway in HT29 human colorectal cancer

Abstract Amentoflavone (AF) is a nature diflavonoid compound that could extract from Ginkgo biloba and Chamaecyparis obtusa. AF had been proven with many biological properties, including anti-oxidant activity, anti-inflammatory, and could also inhibit NF-κB mediating apoptosis to achieve anti-tumor effects in hepatocellular carcinoma. p53, a tumor suppressor gene that could inhibit cell division and proliferation through regulating with cell cycle and apoptosis related molecules. Patients with p53 gene mutation were often resistant to current standard treatment in clinic. Several studies also reported that the activation of p53 could induce apoptosis in colorectal cancer (CRC). Currently, there is no study determine whether AF can inhibit the growth of colorectal cancer by upregulating p53 gene expression. The aim of this study was to investigate the anticancer effect and the underlying mechanism of AF in CRC in vitro and in vivo. First, we indicated the cytotoxic effect was induced by AF in human CRC (HT29) cells. The suppression of metastasis ability including migration and invasion were found to be suppressed by AF treatment group using transwell assay. Also, in colony formation assay, AF inhibited the proliferation of CRC cells. The tumor suppressor gene p53 was upregulating with AF treatment, and the cell cycle related protein, such as CyclinD1 and CDK4 were all downregulated by AF which identified by Western blotting assay. Additionally, AF induced apoptosis in CRC cells were detected by Western blotting and flow cytometry with cleaved caspase-3, -8, -9 and Annexin V/PI assay. Moreover, Western blotting results indicated that DNA damage proteins (cleaved PARP-1 and ATM) were upregulated by AF. The nucleus translocation of caspase-dependent mitochondria initiated apoptotic protein (EndoG and AIF) were induced by AF in CRC cells. In animal experiments, the CRC tumors volume were effectively reduced in AF treatment groups as compared to non-treated control. In summary, AF mediated anti-CRC effects, such as inhibiting cell proliferation, suppressing migration/invasion ability, inducing apoptosis and triggering DNA damage is associated with the induction of p53. Citation Format: Hsiang-Ju Ku, Yuan Chang, I-Tsang Chiang, Fei-Ting Hsu. Amentoflavone induces apoptosis and promotes G1 phase cell cycle arrest through regulating p53 pathway in HT29 human colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5374.

Abstract 6034: Characterization of a novel syngeneic cSCC mouse model to advance immunotherapy treatments

Abstract Cutaneous Squamous Cell Carcinoma (cSCC) is the second most common malignancy diagnosed in Caucasians with an incidence of about one million cases per year. TP53 and p16 are the most common mutated genes in cSCC. Previous studies of cSCC have shown that patients with both p53 and p16 mutations have lower survival rates. There are currently no syngeneic mouse preclinical models to accelerate the efficacy of immunotherapy combinations to treat cSCC. Our laboratory has generated several genetically engineered mouse models (GEMMs) containing tissue-specific p53 and p16 gene mutations. Recently, we have immortalized three murine cSCC cell lines (cSCC-5690, cSCC-8006, and cSCC-8271) derived from spontaneous skin tumors from GEMMs. Therefore, we hypothesized that the double mutant cell line cSCC-5690 enhances cell survival, tumor aggressiveness, and has lower sensitivity to antibody immunotherapy. Protein and RNA expression of the cell lines were validated by western blotting and qRT-PCR assays. Sphere and soft agar assays were used to evaluate the stem cell population and tumorigenicity of the cell lines. Then, we examined the chemosensitivity with cisplatin through clonogenic assays. To further study the tumorigenicity of cells, we evaluated in vivo tumor growth on C57BL/6J immunocompetent mice by injecting subcutaneously the tumor cell lines. The three cell lines expressed different levels of keratin 14 (K14), but cSCC 5690 and 8006 expressed high levels of genes related to oncogenic pathways as well as mesenchymal markers. The cell line cSCC-5690 expressing mutant p53 R172H with p16 gene deletion, showed an enhanced sphere, and colony tumor formation and both tumorigenic cell lines (cSCC-5690, 8006) showed different sensitivities to cisplatin treatment. A higher tumor growth rate was observed with cSCC-5690 compared to cSCC-8006, while cSCC-8271 showed no tumor growth. Immunohistochemistry studies demonstrated that both cSCC-5690 and 8006 tumors expressed vimentin but only cSCC-5690 expressed K14. The most aggressive syngeneic tumor model (cSCC-5690) was used to evaluate the anti-tumor efficiency of anti-PD1, anti-CD47 antibodies, and STING-agonist. Preliminary results revealed a significant tumor response only to STING agonist (c-di-GMP) which activates the innate and adaptive immune response. Therefore, we were able to characterize all three cell lines and established a new mouse model of cSCC as a relevant platform for immunotherapy studies. Citation Format: Alanis Enid Rodriguez Rosario, Roberto Rangel, Jeffrey Myers. Characterization of a novel syngeneic cSCC mouse model to advance immunotherapy treatments [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6034.

Abstract 5842: High resolution melting technique as an economic prognostic tool for identifying deleterious mutations in BRCA1, BRCA2, and P53 genes amongst breast cancer women

Abstract Introduction: The incidence of breast cancer (BC) has substantially increased among women younger than 50. Due to fragile economic situation in the middle east and lack of awareness, BC women are characterized by late diagnosis and thus, there is an urgent need for a cheap early prognostic tool. BC progression involves several genetic mutations via activating oncogenes or disrupting the functions of tumor suppressor genes, such as; BRCA1, BRCA2, P53. Mutation in these genes are associated with an increased risk of breast cancer and thereof, can be used as prognostic markers. High throughput technologies such as next generation sequencing (NGS) with help of different bioinformatic analysis tools give massive data about deleterious mutations in tumor suppressor genes. Therefore, in this study we aimed to establish High Resolution Melting (HRM) technique as an economic prognostic tool for identifying deleterious mutations in BRCA1/2 and P53 genes amongst familial and non-familial breast cancer patients. Patients and Methods: Forty-eight breast cancer patients (15 Familial and 33 non-familial) and 2 healthy volunteers were enrolled in the present study. Genomic DNA was extracted from breast cancer tissues and screened using NGS to identify types of mutations in both BRCA1/2 genes. All positive samples were screened for presence of mutations in BRCA 1(exon 19), BRCA2 (Exon 11F) and P53 (exon 5) using HRM. All samples were analyzed for identifying types of mutations using sanger sequencing. Results: Our results identified 57 different mutations in the three genes. Deleterious mutations are identified as follows; 13 frameshift (c.5345delA (36.3%), c.5321delC (36%), c.5337delA (27.2%)) and 8 missense mutations (c.T5320C (36.3%), c.T5330W(A/T) (27.2%)) in BRCA1 (Exon 19). 6 frameshift mutations (c.3528delA (27.2%)), 13 missense mutations (c.T3840G (72.7%), c.G3839K(G/T) (27.2%)) and 6 synonymous mutations (c.A3895R (A/G) (45.4%)) in BRCA2 (exon11F). Regarding P53 (exon 5), 10 frameshift mutations (c.813insC (63.6%)) were detected. Additionally, some of the sequences were sent to GenBank and obtained the following accession numbers; (OL512955 and OL512956 for BRCA1(Exon 19) and OL512957 for BRCA2 (Exon 11)). Moreover, mutations in the three high penetrance genes; BRCA1, BRCA2 and P53 were correlated with some clinical parameters and results showed that young age and family history were the most prominent ones. Conclusion: The present study successfully established HRM as an economic prognostic tool for identifying the presence of deleterious mutations in BRCA1/2 and P53 genes which will help correlate the presence of mutations on other affected exons when present with other risk factors as prognostic tool in BC women. STDF Acknowledgement: This project was funded by the Science and Technology Development Fund (STDF), Egypt Grant No.22944. Citation Format: Shaza Ahmed, Nasra F. Abdel Fattah, Shimaa A. Metwally, Marwa A. Abdelwahed, Hossam Taha Mohamed, Sara H. Agwa, AbdelWahab El Ghareeb, Gehan Safwat, Ahmed A. El Sherif, Mohamed M. Moneer, Samah A. Loutfy. High resolution melting technique as an economic prognostic tool for identifying deleterious mutations in BRCA1, BRCA2, and P53 genes amongst breast cancer women [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5842.

Abstract 1416: Aurora kinase is synthetic lethal with APC loss of function in engineered human colon organoid models

Abstract Colorectal cancer (CRC) is the second most common cause of cancer-related deaths worldwide. The disease-initiating event in most CRC cases is the loss of function (LOF) of the adenomatous polyposis coli (APC) gene, accounting for 70-80% of CRC. Strategies to target cells that harbor the truncation mutation in APC, which leads to its LOF, may provide the opportunity to intercept tumorigenesis in CRC patients. High-risk CRC populations include patients with familial adenomatous polyposis (FAP), the inherited disorder caused by germline APC mutations. Aurora Kinase (AK), a family of serine/threonine kinases, is essential for proper cell division, and overexpression of AK has been associated with multiple heme and solid tumor malignancies, including CRC. Aurora kinases have been well-studied, both preclinically and clinically, as a target for therapeutic intervention across multiple cancers; however, the role of AK in CRC disease progression has not been fully explored. Here we report a synthetic lethal dependency between APC and AK which was identified in a human isogenic colon organoid model containing a genetically engineered APC LOF (APCLOF). Aurora A-specific, Aurora B-specific, and Pan-AK inhibitors were evaluated in isogenic APCLOF or APCWT colon organoids derived from multiple donors. All AK inhibitors demonstrated selective growth inhibition of the APCLOF organoid. The strongest synthetic lethal effect was observed with a pan-AK inhibitor showing greater than 1000-fold selectivity in the APCLOF colon organoids compared to APCWT. Interestingly, this activity diminished as oncogenic driver mutations in KRAS and/or p53 genes were introduced into the APCLOF organoids. These findings suggest that therapeutic benefit of AK inhibitors would be greater in early APCLOF driven adenomas as opposed to advanced CRC. Despite these encouraging results indicating therapeutic opportunity in early adenoma disease, on-target genotoxicity was observed in vitro through increases in micronuclei at pharmacologic doses. Therefore, although there is a high unmet need in FAP for therapeutic options, potential genotoxicity associated with AK inhibitor treatments may limit utility as an intervention strategy. Citation Format: Dana S. Gaffney, Eileen Vesely, David Pocalyko, Kurtis Bachman, Karla Wiehagen, Glenn Cowley, Victoria Wong, Prashanth Gokare, Peggy Guzzie-Peck, Sandy Weiner, Ann De Smedt, Jacqueline Kinyamu-Akunda, Tammy Bush, Zhuming Zhang, Robert Schulingkamp, Sylvia F. Boj, Rene Overmeer, Carla Verissimo, Roshni Nair. Aurora kinase is synthetic lethal with APC loss of function in engineered human colon organoid models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1416.

Establishment of tumor protein p53 mutation-based prognostic signatures for acute myeloid leukemia

The tumor protein p53 gene (TP53) mutations are associated with poor prognosis of patients with acute myeloid leukemia (AML). This study aimed to establish TP53 mutation-based prognostic risk signatures. The transcriptomes and clinical characteristics of AML patients were acquired from The Cancer Genome Atlas database, including 11 TP53-mutant samples and 114 TP53-wildtype samples. Differentially expressed mRNAs and long non-coding RNAs (lncRNA) in TP53-mutant samples were identified. Weighted gene correlation network analysis was performed to generate survival-associated co-expression modules. LASSO regression analysis was conducted to build mRNA- and lncRNA-based prognostic risk signatures. Kaplan-Meier curve analysis and multivariate regression analysis were carried out to assess the prognostic values of the risk signatures. Receiver operating characteristic (ROC) analysis was performed to evaluate the accuracy of the signatures. Based on the co-expression modules, a 5-mRNA risk signature and a 13-lncRNA risk signature were constructed to predict the overall survival for AML patients. Kaplan-Meier curves revealed that the high-risk patients had significantly shorter overall survival than the low-risk patients. ROC analysis yielded 1-, 3-, and 5-year AUCs of 0.681, 0.783, and 0.827 for mRNA signature and 0.85, 0.835, and 0.908 for lncRNA signature. Multivariate regression analysis revealed that both mRNA (HR=1.45, P< 0.001) and lncRNA (HR=1.19, P< 0.001) risk scores were independent prognostic factors for AML patients. We provided a potential patients stratification tool for AML prognosis prediction and management, which established by effective TP53 mutation-related gene signatures.

P53 Gene Mutation Associated With Worse Clinicopathological Characteristic in Breast Cancer

Background: P53 is a tumour suppresor gene. In breast cancer, p53 gene mutation were noted with frequency of about 30% (range 15 to 71%) and associated with poor prognosis. This study was performed to determine p53 mutation association with clinicopathological characteristic in breast cancer and to assess the suitability of patients’ serum to detect p53 autoantibody. Methods: This study conducted in Hospital Seberang Jaya and Institut Perubatan dan Pergigian Termaju, Universiti Sains Malaysia. Sixty-four breast cancer patients with available fresh breast cancer tissue that been kept under -80°C and with complete clinicopathological, data involve in this study. These fresh breast tissues DNA extracted and 10sampels sent for DNA sequencing. The remaining 54samples proceeded with Polymerase Chains Reaction analysis based on the result from DNA sequencing. The serum of these patients was also taken for p53 autoantibody study using ELISA method. Results: The mean age of the patients in this study was 52.45±9.51 yrs. Most of the patients were Malay with 67.2% followed by Indian and Chinese with 17.2% and 15.6% respectively. 51.6%, of these patients undergone CT scan staging and 14.1% has distant metastases. p53 gene mutation prevalence showed rs1042522 only has 15.7% mutation. There was 54.7% Deletion A and 45.3% Wild Type A detected in rs59758982, 87.5% Deletion A and 12.5% Wild Type A in rs35069695 and 92.2 % recorded for Deletion GAA in rs376546152. There was no significant result between these mutation with breast cancer molecular classification and breast cancer aggressiveness except for rs59758982 shows significant result with p value 0.04 (p &lt;0.05). In regards on for p53 serum autoantibodies, 20.3% of the patients noted to be positive but it has no significant association with p53 gene mutations. Conclusion: In this study, tissue p53 genetic mutation has no significant association with clinicopathological characteristic of breast cancer and the use of serum p53 autoantibody as biomarkers is inconclusive.

Histomorphological Features of Ovarian Neoplasms and Expression of p53 and WT1 in Surface Epithelial Tumours: A Cross-sectional Study

Introduction: Ovary is the most common site of neoplastic and non neoplastic lesion, can present in childhood to postmenopausal age group and remain the most lethal of all gynaecological malignancies. Tumour Protein (p53) gene mutations or deletions are most common in ovarian carcinoma. However, Wilms' Tumor gene1 (WT1) and p16 expression are also seen in serous ovarian carcinoma. These Immunohistochemistry (IHC) marker are useful in the differential diagnosis of serous ovarian carcinomas. Aim: To study histomorphology of ovarian neoplasm along with expression of p53 and WT1 in surface epithelial tumours and to assess the prevalence of various ovarian neoplasms in different age groups. Materials and Methods: This cross-sectional study was conducted in Department of Pathology, Sarojini Naidu Medical College, Agra, Uttar Pradesh, India, over a period of two years (from September 2018-September 2020). A total of 78 ovarian specimen received in histology laboratory was studied for gross and microscopic features. The p53 and WT1 IHC expression pattern was studied in surface epithelial tumours. Statistical significance was calculated in relation to p53 and WT1 expression with histological type and grade of tumour using Chi-square test. Results: A total of 78 cases were studied, out of which benign tumours were the most common 40 (51.3%) cases, followed by malignant tumours 32 (41.0%) cases and borderline malignancy 6 (7.7%) cases. The most common benign lesions were mucinous cystadenoma 20 (50%) cases. Serous carcinomas were most common malignant tumours 19 (59.3%) cases followed by Germ Cell Tumours (GCT) 5 (15.6%) cases. All benign and borderline epithelial ovarian tumours were found p53 and WT1 negative. Out of 22 cases of malignant surface epithelial tumour, 14 (63.6%) and 12 (54.4%) were positive for p53 and WT1 respectively and all were serous carcinomas. Conclusion: Ovarian lesions present with wide spectrum of histomorphological features. The p53 and WT1 show different rates of expression and staining pattern in various epithelial ovarian carcinomas. Hence routine gross, proper histological examination and correct IHC interpretation is required for specific diagnosis.

Molecular and Cytogenetic Study of Acute Myelocytic Leukemia Patients in Kurdistan Region

Considering the high prevalence of acute myelocytic leukemia in adults, understanding the pathophysiology of this disease and investigating cytogenetic markers play an important role in dealing with the disease for its classification, timely diagnosis, prognosis and predicting the response to the treatment process. The aim of this study was to investigate the molecular and cytogenetic status of patients with acute myelocytic leukemia in the Kurdistan region of Iraq. This study was conducted in 2021 on 40 patients referred to Zheen Erbil international hospital who were sampled using the convenience method. Samples were collected from peripheral blood samples or bone marrow samples of patients, after sampling in the laboratory. The processes of sample centrifugation and deoxyribonucleic acid extraction were performed. Then, different in silico tools were used to check the structure and function of proteins. Fluorescence in situ hybridization method was used to check the presence of p53 deletion. The obtained data was analyzed with statistical package for social sciences version 23 and descriptive statistical tests and regression. The average age of the examined patients was 37.275±22.234 y. 17p deletion was seen in 6 people under study and p53 mutation was seen in 13 out of the examined people and normal in 3 patients. Factors affecting acute myelocytic leukemia based on the linear regression were age, Odds ratio (0.014), p value≤0.001, confidence interval: 0.010-0.019 and factors affecting acute myelocytic leukemia mutations (changes) in gene based on the linear regression were p53 mutation, Odds ratio (0.5), p value≤0.003, confidence interval: 0.33-0.019. Evaluation of p53 gene mutation was significant in acute myelocytic leukemia and age also showed itself as an influential factor in acute myelocytic leukemia disease.