Tumor Protein P53 Gene Research Articles

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.

Aqueous extracts from Tenebrio molitor larval and pupal stages inhibit early hepatocarcinogenesis in vivo.

Hepatocellular carcinoma (HCC), which is the most frequent primary liver malignancy, is ranked as the sixth most common cancer and the third leading cause of cancer-related deaths worldwide, with its incidence expected to continue rising. One of the reasons is that most patients are diagnosed at an advanced stage when therapeutic options are ineffective. The development of HCC is attributed to a chronic exposition to either one or a combination of low amounts of different hepatotoxins, such as in hepatitis virus infection, alcohol consumption, aflatoxin from contaminated foods, metabolic factors, and exposure to chemical carcinogens from tobacco smoke (Forner et al., 2018). Integrative studies combining exome sequencing, transcriptome analysis, and the genomic characterization of HCC have shown that these etiological factors may raise the frequency of particular genetic alterations, resulting in intra-tumor heterogeneity that presents a huge challenge for treatment. For example, mutations in the catenin β-1 (CTNNB1) gene (a proto-oncogene in the WNT signaling pathway that encodes the β‍-catenin transcription factor) are strongly associated with alcohol-related HCC, whereas mutations in the telomerase reverse transcriptase (TERT) promoter and tumor protein p53 (TP53) genes are the most commonly observed in hepatitis B virus (HBV)‍-associated HCC (Calderaro et al., 2017; Cancer Genome Atlas Research Network, 2017). The above findings emphasize the molecular diversity of HCC and the associations of different etiologies with distinct mechanisms in HCC progression. Consequently, prevention strategies are still attractive for HCC management.

Bioinformatics Analysis Identifies Precision Treatment with Paclitaxel for Hepatocellular Carcinoma Patients Harboring Mutant TP53 or Wild-Type CTNNB1 Gene.

Hepatocellular carcinoma (HCC) is an aggressive and chemoresistant cancer type. The development of novel therapeutic strategies is still urgently needed. Personalized or precision medicine is a new trend in cancer therapy, which treats cancer patients with specific genetic alterations. In this study, a gene signature was identified from the transcriptome of HCC patients, which was correlated with the patients’ poorer prognoses. This gene signature is functionally related to mitotic cell cycle regulation, and its higher or lower expression is linked to the mutation in tumor protein p53 (TP53) or catenin beta 1 (CTNNB1), respectively. Gene–drug association analysis indicated that the taxanes, such as the clinically approved anticancer drug paclitaxel, are potential drugs targeting this mitotic gene signature. Accordingly, HCC cell lines harboring mutant TP53 or wild-type CTNNB1 genes are more sensitive to paclitaxel treatment. Therefore, our results imply that HCC patients with mutant TP53 or wild-type CTNNB1 genes may benefit from the paclitaxel therapy.

Analysis of tumor protein p53 (p53) mutations in eyelid malignancy

The tumor protein p53 (or p53) gene plays a major role in the maintenance of normal cell growth and differentiation. Alteration in p53 gene is responsible for carcinogenesis. In this study, we evaluated the frequency of p53 mutation and clinicopathological findings in various eyelid malignancies. We reviewed a cohort of 20 patients with various eyelid malignancies over one year. The expression of p53protein was analyzed by amplifying the exons 5-9 of p53 gene by conventional Polymerase Chain Reaction (PCR) followed by sequencing to identify mutations. The commonest eyelid malignancies was sebaceous gland carcinoma (SGC;50%) followed by basal cell carcinoma (BCC;45%) and squamous cell carcinoma(SCC; 5%). Study population/patients were mostly elderly (60 %, > 50 years of age) and female (75%). A total of 14 mutations were identified in the p53 genes in 9/20 (45%) patients at different intron or exon. Amongst them 6 patients (66.7%) had SGC and 3 (33.3%) had BCC. Out of the total 14 mutations identified, 8 intronic variation and 6 exonic mutations were identified. Out of 6 exonic variations, 5 caused frame shift mutations due to insertion or deletion of bases and one case was of substitution mutation (D281Y).Sebaceous gland carcinoma (SGC) was found to be most prevalent eyelid cancer in the present study and it most frequent displayed mutation inthe p53 genes among the all eyelid tumors investigated.

Assessment of the Anti-Cancer Efficiency of Silver Moringa oleifera Leaves Nano-extract against Colon Cancer Induced Chemically in Rats.

Background:Colorectal cancer (CRC) categorized as the most common type of gastrointestinal cancers affected both genders equally. Chemotherapeutic drugs became limited due to their deleterious side effects. Therefore, efficiency of M. oleifera leaves extract increased by incorporating silver nanoparticles (Ag-NPs) then studied against colon cancer induced by azoxymethane (AOM) in rats. Methods:Different hematological and biochemical measurements in addition to specific tumor and inflammatory markers were quantified. Histopathological examination for Colonic tissues was performed. Native proteins and isoenzyme patterns were electrophoretically detected in addition to assaying expression of Tumor Protein P53 (TP53) and Adenomatous Polyposis Coli (APC) genes in colonic tissues.Results: M. oleifera nano-extract restored levels of the hematological and biochemical measurements in addition to levels of tumor and inflammatory markers to normalcy in both of nano-extract simult- and post-treated groups. Also, it minimized severity of the histopathological alterations in the simult-treated group and prevented it completely in the post-treated group. The lowest similarity index (SI%) values were noticed with electrophoretic protein (SI=61.54%), lipid (SI=0.00%) and calcium (SI=75.00%) moieties of protein patterns, catalase (SI=85.71%), peroxidase (SI=85.71%), α-esterase (SI=50.00%) and β-esterase (SI=50.00%) isoenzymes in addition to altering the relative quantities of total protein and isoenzyme bands in colon of cancer induced group. Moreover, levels of TP53 and APC gene expression increased significantly (P≤0.05) in colon cancer induced group. The nano-extract prevented the qualitative and quantitative alterations in the different electrophoretic patterns in addition to restoring levels of the gene expressions to normalcy in both of simult- and post-treated groups. Conclusion: M. oleifera nano-extract exhibited ameliorative effect against the biochemical, physiological and molecular alterations induced by AOM in nano-extract simult- and post-treated groups.

Whole Exome Sequencing Identifies Two Novel Mutations in a Patient with UC Associated with PSC and SSA.

Background Patients diagnosed with ulcerative colitis (UC) associated with primary sclerosis cholangitis (PSC) and sessile serrated adenoma (SSA) are rare. The present study aimed to identify the potential causative gene mutation in a patient with UC associated with PSC and SSA. Methods DNA was extracted from the blood sample and tissue sample of SSA, followed by the whole exome sequencing (WES) analysis. Bioinformatics analysis was utilized to predict the deleteriousness of the identified variants. Multiple sequence alignment and conserved protein domain analyses were performed using online software. Sanger sequencing was used to validate the identified variants. Expression and diagnostic analysis of identified mutated genes was performed in the GSE119600 dataset (peripheral blood samples of PSC and UC) and GSE43841 dataset (tumor samples of SSA). Results In the present study, a total of 842 single nucleotide variants (SNVs) in 728 genes were identified in the blood sample. Two variants, integrin beta 4 (ITGB4) (c.C2503G; p.P835A) and a mucin 3A (MUC3A) (c.C1019T; p.P340L), were further analyzed. MUC3A was associated with inflammatory bowel disease. Sanger sequence in blood revealed that the ITGB4 mutation was fully cosegregated with the result of WES in the patient. Additionally, a variant, tumor protein p53 gene (TP53) (c.86delA; p.N29Tfs∗15) was identified in the tissue sample of SSA. Compared to that in normal controls, ITGB4 was upregulated in both UC and PSC, MUC3A was, respectively, upregulated and downregulated in PSC and UC, and TP53 was downregulated in SSA. ITGB4 and TP53 had a potential diagnostic value for UC, PSC and SSA. Conclusions The present study demonstrated that the ITGB4 (c.C2503G; p.P835A) and MUC3A (c.C1019T; p.P340L) mutations may be the potential causative variants in a patient with UC associated with PSC and SSA. TP53 (c.86delA; p.N29Tfs∗15) mutation may be associated with SSA in this patient.

A study of the TP53 Germline Mutation and Clinicopathologic Features in Thai Children with Adrenocortical Carcinoma

Objective: To determine the clinicopathologic features and germline tumor protein p53 (TP53) mutation in children with adrenocortical carcinoma (ACC).Material and Methods: This was a retrospective study. From 2009 to 2018, children with ACC from King Chulalongkorn Memorial Hospital and Phramongkutklao Hospital were enrolled into the study. Clinical presentations and hormonal profiles were recorded. Mutation analyses of the TP53 gene were acquired using the next-generation-sequencing method which was performed for germline samples of all patients and the parents of those who tested positive.Result: Two males and six females with ACC were enrolled into this study. The median age at diagnosis was 25.5 months (range 10 to 67 months). All participants had virilization, either virilization only (n=3) or associated with Cushing (n=5). All participants had had surgery to completely remove all of the tumor and three participants had received adjuvant chemotherapy consisting of etoposide, doxorubicin, and cyclophosphamide. All participants had three different known mutations in the TP53 gene: c.1010G>A (p.R337H), c.916C>T (p.R306*) and c.743G>A (p.R248Q). Two of the three participants with TP53 mutations had pulmonary metastasis. One participant had wild-type TP53 and pulmonary recurrence occurred one year after diagnosis. The median follow-up time was 31 months (range 10 to 168 months. As of this writing, seven participants survived without evidence of recurrence. No second malignancy was found in all participants. One participant who had c.916C>T died of pulmonary metastasis 10 months after diagnosis.Conclusion: We successfully identified three different germline TP53 mutations in patients with ACC. Progression to pulmonary metastasis and recurrence were higher among participants with TP53 mutations. The treatment outcome of childhood ACC was good when surgery and adjuvant chemotherapy were used.

Abstract 2492: Association of TP53 and LRP1B co-mutation status with response to immunotherapy in lung squamous cell carcinoma

Abstract Background: Immunotherapy can induce a long response in part patients of lung squamous cell carcinoma (LUSC). And accurate biomarkers are needed for suitable populations. As important tumor suppressor, tumor protein p53 (TP53) and low density lipoprotein receptor-related protein 1B (LRP1B) genes may be associated with immunogenicity. However, the interaction of TP53 and LRP1B and its potential association with response to immunotherapy are not fully understood in LUSC. Methods: Three cohorts were divided into four groups, respectively (A: TP53mut and LRP1Bmut, B: TP53mut and LRP1Bwild, C: TP53wild and LRP1Bmut, D: TP53wild and LRP1Bwild). 525 LUSCs form Geneplus database which performed next-generation sequencing were assessed the differences of genomic landscape, tumor mutation burden (TMB), and PD-L1 expression in four groups (cohort 1). TCGA-LUSC RNA data (n=466) from cBioPortal were used to evaluate immune cell infiltration thought single sample gene set enrichment analysis (cohort 2). The LUSCs (n=125) which received immunotherapy of POPLAR and OAK cohort were used to evaluate the efficacy of immunotherapy in four groups (cohort 3). Results: The proportion of patients in A, B, C and D groups of cohort 1 was 26%, 59%, 2%, 13%, respectively, suggesting that most patients with LRP1B mutation also carry TP53 mutation (98.6%) in LUSC. This similar ratio is 88.2% in cohort 2 and 74.3% in cohort 3. For group A, the most common mutated gene except TP53 and LRP1B was CDKN2A (31%). Group B was MLL2(28%). Group C was CDKN2A (33%). Group D was FAT1 (13%). The median TMB was 14.4 mutations/Mb (2.9-80.0) in group A, 9.8 (0.96-95.0) in group B, 11.5 (2-25) in group C, 3.8 (0.96-18.2) in group D. TP53 and LRP1B co-mutation had a highest TMB compared with the other three groups in all cohorts, while TP53wild and LRP1Bwild completely opposite. In cohort 1, PD-L1 expression had no significant difference in four groups. In cohort 3, progression-free survival (PFS) was longer in group D compared with the other three groups (p = 0.047, A: 1.5m, B: 1.6m, C: 2.1m, D: 4.2m). The same trend on overall survival (OS) were found but it was not significant. Group D also had a higher disease control rate (A: 50%, B: 46%, C: 44%, D: 69%). We than divide into two groups (D vs Other) to compare PFS and OS. It showed that group D had a prolonged PFS (p = 0.02) and OS (p = 0.03). Multivariate cox regression analysis showed that the results were independent of TMB, gender and age. Analysis of immune cell infiltration in cohort 2 showed that the better outcomes of group D might associated with elevated infiltrations of activated dendritic cell and activated CD8 T cell. Conclusion: TP53mut and LRP1Bmut, which accounted for a high proportion of LUSC, was associated with high TMB. And TP53wild and LRP1Bwild has better anti-PD-L1 outcome in LUSC. This might be related with a stronger activated dendritic cell and activated CD8 T cell infiltration despite lower TMB. Citation Format: Jiangyong Yu, Zhipeng Zhou, Ping Zhang, Pansong Li, Xu Li, Min Tang, Nannan Fan, Xiaonan Wu, Xin Nie, Xiaoyan Chen, Di Ma, Xi Chen, Yanfang Guan, Xuefeng Xia, Ling Yang, Xin Yi, Lin Li. Association of TP53 and LRP1B co-mutation status with response to immunotherapy in lung squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2492.

Oncological Follow-up with 2-[18F]-FDG PET/CT in Li-Fraumeni Syndrome

Li-Fraumeni syndrome is a rare disorder caused by abnormalities of the tumor-suppressor protein P53 gene. We present the case of a 26-years-old female diagnosed with bilateral ductal carcinoma. The genetic panel for breast cancer gene 1 (BRCA1) and BRCA2 mutations was negative and positive heterozygous germline tumor protein P53 gene mutations, considering Li-Fraumeni syndrome. A 2-[18F]-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) was used for postsurgical staging to show the right lung hypermetabolic nodule. A lobectomy was accomplished, and histopathology reported pulmonary adenocarcinoma. A year later, oncological follow-up was conducted with 2-[18F]-FDG PET/CT without evidence of abnormalities.

The G199X and V157fs mutations in the TP53 gene promote malignancy in serous ovarian cancer: an analysis using whole-exome sequencing.

BackgroundThe carcinogenic mechanisms underlying serous ovarian cancer are not fully understood.MethodsWhole-exome sequencing and targeted sequencing were performed in ovarian cancer samples to identify novel molecular markers involved in the process of cell malignancy in ovarian cancer. In vitro experiments, the oncogenic roles such as cell proliferation, migration and invasion of TP53 G199X and V157fs mutations were investigated deeply.ResultsThe present study identified the G199X and V157fs point mutations in the tumor protein P53 gene (TP53). The rate of TP53 mutation was 59.2% in a cohort of 76 ovarian cancer patients, compared with 9.0% in a cohort of 156 healthy women. Kaplan-Meier analysis showed that patients with a TP53 mutation had a lower 5-year overall survival (OS) rate compared with patients harboring wild type TP53. In vitro experiments in an ovarian cancer cell line demonstrated that the G199X and V157fs mutants inhibited P53 protein expression, enhanced proliferation, promoted migration and increased invasion.ConclusionsThis study identified two novel markers, TP53 G199X and V157fs mutations in TP53. Functional assays indicated that these mutations enhanced the malignant phenotype in ovarian cancer cells. These novel markers will assist in the diagnosis of ovarian tumors and represent potential targets for the treatment of TP53 mutant ovarian cancers.

Molecular and <em>in silico</em> Study of TP53 Codon 72 Polymorphism (rs1042522) in a Population Exposed to High Background Radiation in Mamuju-West Sulawesi

The evaluation of the tumor protein p53 (TP53) codon 72 polymorphism (rs1042522) status in a population exposed to high background radiation was performed in this study. Real-time polymerase chain reaction (Q-PCR) was used to genotype the rs1042522 polymorphism in 100 subjects from Takandeang, Salleto, and Ahu villages in Mamuju district, West Sulawesi. An in silico study was then conducted to identify the potential effects of the proline substitution associated with this polymorphism on protein stability. The in silico analysis was performed using three different computational tools, namely I-Mutant Suite, iStable, and Protein Variation Effect Analyzer (PROVEAN). Secondary and three-dimensional (3D) structural models for wild-type (WT) and variant TP53 were generated to predict potential structural changes in the protein. Electrostatic surface charge calculations were also performed to identify changes in the electrostatic charge of codon 72. The Pro72 and Arg72 frequencies among the inhabitants in the Takandeang, Salleto, and Ahu villages, who are Mandarese Austronesian-speaking ethnic group members, were 0.56 and 0.44, respectively. The in silico analysis revealed no negative effects on protein stability due to the proline substitution at codon 72, although molecular modeling showed several differences in the secondary and 3D structures of the TP53 variant compared with the structure of WT TP53. To determine the impact of the proline-coding allele on individual sensitivity to radiation exposure, we compared the micronucleus (MN) frequencies of each genotype. The results showed that the MN frequencies in individuals harboring the proline-coding allele were not significantly higher than those expressing the arginine-coding allele. In conclusion, this study revealed that the proline-coding allele for codon 72 of the TP53 gene represented the predominant genotype among Takandeang, Salleto, and Ahu villages inhabitants. The present study also demonstrated that individuals who carried the proline-coding allele were not more sensitive to radiation compared with those expressing the arginine-coding allele for codon 72 of the TP53 gene.

Clinical and biological features of B-cell neoplasms with CDK6 translocations: an association with a subgroup of splenic marginal zone lymphomas displaying frequent CD5 expression, prolymphocytic cells, and TP53 abnormalities.

A translocation involving the cyclin-dependent kinase 6 (CDK6) gene [t(CDK6)] is a rare but recurrent abnormality in B-cell neoplasms. To further characterise this aberration, we studied 57 cases; the largest series reported to date. Fluorescence in situ hybridisation analysis confirmed the involvement of CDK6 in all cases, including t(2;7)(p11;q21) immunoglobulin kappa locus (IGK)/CDK6 (n=51), t(7;14)(q21;q32) CDK6/immunoglobulin heavy locus (IGH) (n=2) and the previously undescribed t(7;14)(q21;q11) CDK6/T-cell receptor alpha locus (TRA)/T-cell receptor delta locus (TRD) (n=4). In total, 10 patients were diagnosed with chronic lymphocytic leukaemia, monoclonal B-cell lymphocytosis or small lymphocytic lymphoma, and 47 had small B-cell lymphoma (SmBL) including 36 cases of marginal zone lymphoma (MZL; 34 splenic MZLs, one nodal MZL and one bronchus-associated lymphoid tissue lymphoma). In all, 18 of the 26 cytologically reviewed cases of MZL (69%) had an atypical aspect with prolymphocytic cells. Among the 47 patients with MZL/SmBL, CD5 expression was found in 26 (55%) and the tumour protein p53 (TP53) deletion in 22 (47%). The TP53 gene was mutated in 10/30 (33%); the 7q deletion was detected in only one case, and no Notch receptor 2 (NOTCH2) mutations were found. Immunoglobulin heavy-chain variable-region (IGHV) locus sequencing revealed that none harboured an IGHV1-02*04 gene. Overall survival was 82% at 10years and not influenced by TP53 aberration. Our present findings suggest that most t(CDK6)+ neoplasms correspond to a particular subgroup of indolent marginal zone B-cell lymphomas with distinctive features.

Mechanism of miR-122-5p regulating the activation of PI3K-Akt-mTOR signaling pathway on the cell proliferation and apoptosis of osteosarcoma cells through targeting TP53 gene.

To explore the regulatory mechanism of microRNA-122-5p (miR-122-5) targeting tumor protein p53 (TP53) gene to mediate PI3K-Akt-mTOR signaling pathway on the proliferation and apoptosis of osteosarcoma (OS) cells. With the collection of osteosarcoma and normal adjacent tissues, the mRNA of miR-122-5p, TP53, PTEN, PI3K, Akt, mTOR, Bim, Bax, and Bcl-2 was detected by Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR), followed by the detection of the protein expression by Western blot. The target relationship between miR-122-5p and TP53 gene was verified. The third generation osteosarcoma cells were divided into Blank group, miR-122-5p mimic negative control (NC) group, miR-122-5p mimic group, miR-122-5p inhibitor NC group, miR-122-5p inhibitor group, rapamycin group and miR-122-5p inhibitor + rapamycin group. Furthermore, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry were used to detect the proliferation ability, cell cycle distribution and apoptosis of each group after transfection. The expression level of miR-122-5p in osteosarcoma was lower than that in normal tissues (p < 0.05), TP53, PTEN, Bim and Bax expression levels were decreased (all p < 0.05), while the expression levels of PI3K, p-PI3K, Akt, p-Akt, mTOR, p-mTOR and Bcl-2 were highly upregulated (all p < 0.05). TP53 had the lowest expression in osteosarcoma cell line U-2OS (p < 0.05), which was selected for subsequent cell experiments. TP53 was the target gene of miR-122-5p. Compared with Blank group, miR-122-5p mimic group had increased expression of miR-122-5p (all p < 0.05); besides, there were significantly increased expression of TP53, PTEN, Bim, and Bax in miR-122-5p mimic group and rapamycin group, while remarkably decreased expression of PI3K, p-PI3K, Akt, p-Akt, mTOR, p-mTOR, and Bcl-2 (all p < 0.05), accompanied by increased proportion of cells in G0/G1 phase, decreased cell proportion in S phase, increased cell apoptosis and inhibited cell proliferation (all p < 0.05). The opposite trends were found in miR-122-5p inhibitor group relative to miR-122-5p mimic group and rapamycin group (all p < 0.05). Meanwhile, no significant difference was found in miR-122-5p inhibitor+rapamycin group when compared with that in Blank group (all p > 0.05) except for significantly decreased miR-122-5p expression (p < 0.05). Upregulation of miR-122-5p may inhibit the proliferation and promote the apoptosis of osteosarcoma cells by inhibiting the activation of PI3K-Akt-mTOR signaling pathway, which may be related to the targeted up-regulation of TP53 expression.

Different Gene Mutation Spectrum of the Paired CSF and Plasma Samples in Lung Adenocarcinoma with Leptomeningeal Metastases: the Liquid Biopsy Based on Circulating Tumor DNA

背景与目的软脑膜转移(leptomeningeal metastasis, LM)是晚期非小细胞肺癌(non-small cell lung cancer, NSCLC)的一种严重并发症, 通常预后较差。对于驱动基因阳性的NSCLC患者, 表皮生长因子受体酪氨酸激酶抑制剂(epidermal growth factor receptor-tyrosine kinase inhibitors, EGFR-TKIs)是治疗的首选, 但常伴随着无法解决的耐药问题。本研究旨在探讨NSCLC-LM患者的脑脊液(cerebrospinal fluid, CSF)和血液中不同的基因突变谱及突变丰度, 筛查相关耐药基因, 以期能精确指导个体化的治疗。方法采用二代基因测序(next generation sequencing, NGS)的液体活检技术, 检测、对比分析TKI耐药后NSCLC患者同期的外周血及脑脊液中的循环肿瘤DNA(circulating tumor DNA, ctDNA)。结果共纳入18例NSCLC伴有LM的患者, 基础突变中11例(61.11%)为EGFR, 6例(33.33%)为间变性淋巴瘤激酶(anaplastic lymphoma kinase, ALK), 1例(5.56%)为原癌基因酪氨酸蛋白激酶ROS(ROS proto-oncogene 1, receptor tyrosine kinase, ROS1), 伴随突变中肿瘤蛋白P53(tumor protein p53 gene, TP53)、间质-上皮细胞转化因子(mesenchymal-epithelial transition factor, MET)检出率相对较高。CSF样本的靶向基因突变检出率明显高于外周血(100.00% vs 66.67%, P=0.006), 且基础突变基因的CSF丰度均明显高于血浆样本(P < 0.001)。CSF样本检测出丰富的单核苷酸变异(single-nucleotide variations, SNV)和拷贝数变异(copy number variants, CNV), 数量均多于血液样本；且相较于只接受过单一TKI治疗的患者, 使用多种TKI后脑脊液和血液中会产生更多的SNV突变。结论NSCLC-LM患者CSF中的ctDNA, 相较于外周血, 能更加准确、全面地反映出LM的真实基因突变状态, 在指导用药、耐药监测、预后评估等方面具有广泛的应用前景, 可作为液体活检的优选。

Point mutation screening of tumor neoantigens and peptide-induced specific cytotoxic T lymphocytes using The Cancer Genome Atlas database.

The aim of the present study was to use The Cancer Genome Atlas (TCGA) database to identify tumor neoantigens, combined with a bioinformatics analysis to design and analyze antigen epitope peptides. Epitopes were screened using immunogenicity tests to identify the ideal epitope peptides to target tumor neoantigens, which can specifically activate the immune response of T cells. The high-frequency mutation loci (top 10) of colorectal, lung and liver cancer genes were screened using TCGA database. The antigenic epitope peptides with high affinity for major histocompatibility complex molecules were selected and synthesized using computer prediction algorithms, and were subsequently detected using flow cytometry. The cytotoxicity of specific cytotoxic T lymphocytes (CTLs) on peptide-loaded T2 cells was initially verified using interferon IFN-γ detection and a calcein-acetoxymethyl (Cal-AM) release assay. Tumor cell lines expressing point mutations in KRAS, TP53 and CTNNB1 genes were constructed respectively, and the cytotoxicity of peptide-induced specific CTLs on wild-type and mutant tumor cells was verified using a Cal-AM release assay and carboxyfluorescein succinimidyl ester-propidium iodide staining. The high-frequency gene mutation loci of KRAS proto-oncogene (KRAS) G12V, tumor protein p53 (TP53) R158L and catenin β1 (CTNNB1) K335I were identified in TCGA database. A total of 3 groups of wild-type and mutant peptides were screened using a peptide prediction algorithm. The CTNNB1 group had a strong affinity for the human leukocyte antigen-A2 molecule, as determined using flow cytometry. The IFN-γ secretion of specific CTLs in the CTNNB1 group was the highest, followed by the TP53 and the KRAS groups. The killing rate of mutant peptide-induced specific CTLs on peptide-loaded T2 cells in the CTNNB1 group was higher compared with that observed in the other groups. The killing rate of specific CTLs induced by mutant peptides present on tumor cells was higher compared with that induced by wild-type peptides. However, when compared with the TP53 and KRAS groups, specific CTLs induced by mutant peptides in the CTNNB1 group had more potent cytotoxicity towards mutant and wild-type tumor cells. In conclusion, point mutant tumor neoantigens screened in the three groups improved the cytotoxicity of specific T cells, and the mutant peptides in the CTNNB1 group were more prominent, indicating that they may activate the cellular immune response more readily.

Toxicogenetic and antiproliferative effects of chrysin in urinary bladder cancer cells.

The antitumour activity of chrysin have been studied in several types of cancer cells. In urinary bladder cancer, its cytotoxic effects have already demonstrated; however, its mechanism of action is not completely understood and the role of tumour protein p53 (TP53) gene in these effects is unclear. In this study, we investigated the role of chrysin (10, 20, 40, 60 80 and 100 µM) in progression of bladder tumour cells with different status of the TP53 gene and different degrees of tumour (RT4, grade 1, TP53 wild type; 5637, grade 2, TP53 mutated and T24, grade 3, TP53 mutated). Results demonstrated that chrysin inhibited cell proliferation by increasing reactive oxygen species and DNA damage and inhibited cell migration in all cell lines. In TP53 wild-type cells, a sub-G1 apoptotic population was present. In mutated TP53 cells, chrysin caused arrest at the G2/M phase and morphological changes accompanied by downregulation of PLK1, SRC and HOXB3 genes. In addition, in Grade 2 cells, chrysin induced global DNA hypermethylation and, in the highest-grade cells, downregulated c-MYC, FGFR3 and mTOR gene expression. In conclusion, chrysin has antiproliferative and toxicogenetic activity in bladder tumour cells independently of TP53 status; however, the mechanisms of action are dependent on TP53 status.

The prognostic impact of variant allele frequency (VAF) in TP53 mutant patients with MDS: A systematic review and meta-analysis.

Tumor protein p53 (TP53) is frequently expressed in patients with myelodysplastic syndromes (MDS). Studies have already reported the poor prognostic impact of TP53 gene mutations in MDS patients. However, parts of this subgroup of patients with low-risk MDS still have relatively better survival and longer remission times. Therefore, we performed a meta-analysis to evaluate the prognostic difference intra-gene of variant allele frequency (VAF). The primary endpoint was overall survival (OS), and event-free survival (EFS) was selected as the secondary endpoint. We extracted the hazard ratio (HR) and 95% confidence interval (CI) for OS and EFS from univariate and multivariate Cox proportional hazard models. A total of 4003 MDS patients and 1278 TP53-mutated patients from 13 cohorts of 11 studies up to February 24, 2020, were included in our meta-analysis. Pooled HRs suggested that a high mutant VAF had an adverse impact on OS (HR=2.11, 95% CI: 1.48-3.01, P<.0001) but no impact on EFS (HR=15.57, 95% CI: 0.75-324.44, P=.003) in MDS patients. Twenty percent is a proper threshold to set (HR=2.02, 95% CI: 1.31-3.13, P=.001) and is a rough line between high clone burden and low clone burden, while 40% is an exact cutoff point (HR=2.11, 95% CI: 1.26-3.55, P<.0001) to guide diagnosis and treatment. Beyond the traditional binary classification of gene mutation, we aimed to find a way to divide mutant molecular markers more specifically by VAF to provide clinical therapeutic values. Our meta-analysis indicates that a high VAF is an independent, adverse prognostic factor for OS in TP53 mutant MDS patients. Patients with mediate/low-frequency parts who could be treated like wide-type patients have relatively better survival and may choose allogeneic hematopoietic stem cell transplantation as conditions permitting. Further prospective studies are needed in the future, and a large subgroup analysis of the same cutoff point subgroups is needed to obtain a more reliable basis for the impact of other mutant gene VAFs on the prognosis of MDS.

TP53 Status, Patient Sex, and the Immune Response as Determinants of Lung Cancer Patient Survival.

Lung cancer poses the greatest cancer-related death risk and males have poorer outcomes than females, for unknown reasons. Patient sex is not a biological variable considered in lung cancer standard of care. Correlating patient genetics with outcomes is predicted to open avenues for improved management. Using a bioinformatics approach across non-small cell lung cancer (NSCLC) subtypes, we identified where patient sex, mutation of the major tumor suppressor gene, Tumour protein P53 (TP53), and immune signatures stratified outcomes in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC), among datasets of The Cancer Genome Atlas (TCGA). We exposed sex and TP53 gene mutations as prognostic for LUAD survival. Longest survival in LUAD occurred among females with wild-type (wt) TP53 genes, high levels of immune infiltration and enrichment for pathway signatures of Interferon Gamma (INF-γ), Tumour Necrosis Factor (TNF) and macrophages-monocytes. In contrast, poor survival in men with LUAD and wt TP53 genes corresponded with enrichment of Transforming Growth Factor Beta 1 (TGFB1, hereafter TGF-β) and wound healing signatures. In LUAD with wt TP53 genes, elevated gene expression of immune checkpoint CD274 (hereafter: PD-L1) and also protein 53 (p53) negative-regulators of the Mouse Double Minute (MDM)-family predict novel avenues for combined immunotherapies. LUSC is dominated by male smokers with TP53 gene mutations, while a minor population of TCGA LC patients with wt TP53 genes unexpectedly had the poorest survival, suggestive of a separate etiology. We conclude that advanced approaches to LUAD and LUSC therapy lie in the consideration of patient sex, TP53 gene mutation status and immune signatures.

Understanding the genetics of gastric and esophageal cancer using Drosophila melanogaster as a model organism

Drosophila melanogaster, a vicious model, has helped in significant discoveries about several conserved mechanisms. The insect intestine had remained unexplored until the identification of adult somatic stem cells which triggered the invention of genetic amenability of this insect organ in powerful and artistic ways. A variety of mechanisms within the fruit flies' intestine are conserved in human gastrointestinal systems and will, therefore, become relevant within the context of human pathologies such as gastrointestinal cancers and obesity. In line with current guidelines, maintaining a high degree of suspicion of hereditary etiology (genetic involvement) helps in disease diagnosis. In this review, genetics of two crucial cancers are discussed. Mutation or transcriptional silencing of the cadherin-1 (CDH1) gene and tumor protein p53 gene is related to familial diffuse gastric cancer (GC) and esophageal adenocarcinoma, respectively. Testing for CDH1 mutations in patients with familial clustering of hereditary diffuse GC has proven consistent. Further studies on the expression and also the alteration within the proteins within the E-CDH pathways and Hippo pathway may function as biomarkers for early detection. Dysregulation of various mechanisms ends up in invasion, proliferation, and metastases. The promise of targeted therapy and personalized medicine in improving the clinical outcome is now closer than it has ever been.

Evaluation of the CRISPR/Cas9 directed mutant TP53 gene repairing effect in human prostate cancer cell line PC-3.

Prostate cancer is a common health problem among men worldwide and most of these prostate cancer cases are related to a dysfunctional mutant Tumor Protein p53 (TP53) gene. However, the CRISPR/Cas9 system can be used for repairing of a dysfunctional mutant TP53 gene in combination with donor single-stranded oligodeoxynucleotide (ssODN) via cells' own homology-directed repair (HDR) mechanism. In this study, we aimed to evaluate the CRISPR/Cas9 repairing efficiency on TP53 414delC (p.K139fs*31) null mutation, located in the TP53 gene, of human prostate cancer cell line PC-3 in combination with ssODNs. According to the next-generation sequencing results, TP53 414delC mutation was repaired with an efficiency of 19.95% and 26.0% at the TP53 414delC position with ssODN1 and ssODN2 accompanied by sgRNA2 guided CRISPR/Cas9, respectively. Besides, qPCR and immunofluorescence analysis showed that PC-3 cells, the TP53 414delC mutation of which were repaired, expressed wild type p53 again. Also, significantly increased number of apoptotic cells, driven by the repaired TP53 gene were detected compared to the control cells by flow cytometry analysis. As a result, sgRNA2 guided CRISPR/Cas9 system accompanied by ssODN was shown to effectively repair the TP53 414delC gene region and inhibit the cell proliferation of PC-3 cells. Therefore, the effects of the TP53 414delC mutation repairment in PC-3 cells will be investigated in the in vivo models for tumor clearance analysis in the near future.