Mutant P53 Expression Research Articles

HPV-Independent Cervical Adenocarcinoma Discovered by Cytology-Based Screening: A case report of gastric type adenocarcinoma of the uterine cervix from cytopathology to histopathology

Abstract Introduction/Objective In recent years, the relative prevalence of adenocarcinoma has increased, comprising 20–25% of all cervical carcinomas in developed countries. Approximately 15% of cervical adenocarcinomas are unrelated to human papilloma virus (HPV) infection. With the shift toward HPV primary testing, an increased understanding of HPV-independent cervical adenocarcinomas becomes more important. Methods/Case Report This case report demonstrates a rare case of gastric-type adenocarcinoma (GAS) of the cervix discovered during a routine well-woman exam. Patient-reported episodes of vaginal spotting were noted prior to screening. HPV testing by PCR on the initial pap smear was negative. Cytology findings raised concerns about endocervical glandular cell abnormalities. Subsequent cervical biopsy revealed GAS, a finding supported by positive CK7, MUC5AC, CDX2, and aberrant (mutant) p53 expression by immunohistochemistry. HPV independence was further confirmed by negative results on mRNA ISH for high-risk HPV and HPV16/18. Results (if a Case Study enter NA) NA Conclusion Here we discuss the impact of cytology-based screening on HPV-independent cervical cancers, with focus on adenocarcinoma. While the move to primary HPV screening has been shown to be effective at identifying HPV-related neoplasms, it ineffectively addresses HPV-independent malignancies. In this particular population, cytology-based screening remains indispensable. The described case demonstrated subtle cytologic features consistent with endocervical glandular abnormality, ultimately correlating with subsequent histologic findings of HPV-independent GAS. Negative HPV results combined with subtle cytomorphologic changes displayed by some adenocarcinomas on PAP smear could present a significant diagnostic pitfall. Additionally, p16+ expression attributable to aberrant p53 pathways (rather than HPV) may further contribute to potential diagnostic errors. While further research into best practices for early detection of HPV-independent cervical neoplasias should be conducted, this team suggests both clinical survey and referral for cytologic screening following reports of abnormal vaginal bleeding and/or watery discharge and screener education focused on cervical GAS.

Biomarker Profiles and Clinicopathological Features in Head and Neck Squamous Cell Carcinoma Patients.

Background and Objectives: Head and neck squamous cell carcinomas (HNSCCs) vary significantly in terms of invasiveness, growth rate, and metastatic potential. This study aimed to investigate the expression of several prognostic biomarkers (Ki67, p53, EGFR, COX-2, Cx43, and p16) in HNSCC from various anatomical regions and to correlate these expressions with clinicopathological parameters. Materials and Methods: We performed immunohistochemistry on 91 histologically verified HNSCC cases from the County Emergency Hospital, Targu Mures. Biomarker expression for Ki67, COX-2, and Cx43 was assessed using a standard immunoexpression scoring system: S1: 0-10%, S2: 11-25%, S3: 26-50%, S4 > 50%; EGFR was scored based on membrane staining intensity: 0, 1+, 2+, 3+; we classified p16 as positive or negative; p53 was grouped into mutant and wild-type; and we compared these across histopathological types, tumor grades, anatomical locations, gender, and different age groups. We performed a comparative analysis of Cx43 expression levels in relation to the expression of the rest of the markers. Statistical analysis was conducted using GraphPad InStat 3 software, version 3.06 (GraphPad Software Inc., San Diego, USA). Results: The majority of tumors were in males (95.6%) aged 51-60 years. Mutant p53 expression was prevalent in most cases. Elevated Ki67 and EGFR expression were associated with more aggressive tumors. COX-2 levels varied, with a higher proportion of moderate and high immunoexpression (S3 + S4) observed in patients under 70 years old. Cx43 expression was generally low, especially in extralaryngeal tumors. Conclusions: HNSCC primarily affects older males, with the larynx being the most common site. High levels of Ki-67 and EGFR suggest more aggressive tumors, while low COX-2 levels reflect varying prognoses. Women may develop more aggressive tumors, and extralaryngeal tumors often present with more challenging prognoses. Low Cx43 expression may be more likely to coincide with higher Ki67 and COX-2 levels, possibly indicating a link with more aggressive tumor behavior.

Exploring the therapeutic potential of simvastatin in pancreatic neuroendocrine neoplasms: insights into cell cycle regulation and apoptosis.

Pancreatic neuroendocrine neoplasm (pNEN) poses significant challenges in clinical management due to their heterogeneity and limited treatment options. In this study, we investigated the potential of simvastatin (SIM) as an anti-tumor agent in pNEN. We conducted cell culture experiments using QGP-1 and BON-1 cell lines and assessed cell viability, proliferation, migration, and invasion following SIM treatment. To further validate our findings, we performed in vivo experiments using a mouse xenograft model. Additionally, we investigated the underlying molecular mechanisms by analyzing changes in cell cycle progression, apoptosis, and signaling pathways. SIM treatment suppresses pNEN growth both in vitro and in vivo, and led to G1 phase arrest in QGP-1 cells. In contrast, SIM affected both the G1-S and G2-M phase transitions in the BON-1 cell line and induced apoptosis, indicating diverse mechanisms of action. Furthermore, SIM treatment resulted in decreased expression of mutant p53 (mutp53) in BON-1 cells, suggesting a potential therapeutic strategy targeting mutp53. Modulation of the MAPK pathway was also implicated in QGP-1 cells. Our study highlights SIM as a promising candidate for pNEN treatment by inducing cell cycle arrest or apoptosis, potentially through the p53 and MAPK pathways. Further research is warranted to fully elucidate SIM's mechanisms of action and evaluate its therapeutic potential in clinical settings.

CircCFL1 Promotes TNBC Stemness and Immunoescape via Deacetylation-Mediated c-Myc Deubiquitylation to Facilitate Mutant TP53 Transcription.

Triple-negative breast cancer (TNBC) is the most malignant subtype of breast cancer. TP53, which has a mutation rate of ≈70%-80% in TNBC patients, plays oncogenic roles when mutated. However, whether circRNAs can exert their effects on TNBC through regulating mutant TP53 has not been well evaluated. In this study, circCFL1, which is highly expressed in TNBC cells and tissues and has prognostic potential is identified. Functionally, circCFL1 promoted the proliferation, metastasis and stemness of TNBC cells. Mechanistically, circCFL1 acted as a scaffold to enhance the interaction between HDAC1 and c-Myc, further promoting the stability of c-Myc via deacetylation-mediated inhibition of K48-linked ubiquitylation. Stably expressed c-Myc further enhanced the expression of mutp53 in TNBC cells with TP53 mutations by directly binding to the promoter of TP53, which promoted the stemness of TNBC cells via activation of the p-AKT/WIP/YAP/TAZ pathway. Moreover, circCFL1 can facilitate the immune escape of TNBC cells by promoting the expression of PD-L1 and suppressing the antitumor immunity of CD8+ T cells. In conclusion, the results revealed that circCFL1 plays an oncogenic role by promoting the HDAC1/c-Myc/mutp53 axis, which can serve as a potential diagnostic biomarker and therapeutic target for TNBC patients with TP53 mutations.

Gastric SMARCA4-deficient undifferentiated tumor (SMARCA4-UT): a clinicopathological analysis of four rare cases

BackgroundSMARCA4, as one of the subunits of the SWI/SNF chromatin remodeling complex, drives SMARCA4-deficient tumors. Gastric SMARCA4-deficient tumors may include gastric SMARCA4-deficient carcinoma and gastric SMARCA4-deficient undifferentiated tumor (SMARCA4-UT). Gastric SMARCA4-UT is rare and challenging to diagnose in clinical practice. The present report aims to provide insight into the clinicopathological characteristics and genetic alterations of gastric SMARCA4-UTs.ResultsWe retrospectively reported four rare cases of gastric SMARCA4-UTs. All four cases were male, aged between 61 and 82 years. These tumors presented as ulcerated and transmural masses with infiltration, staged as TNM IV in cases 1, 2 and 4, and TNM IIIA in case 3. Pathologically, four cases presented solid architecture with undifferentiated morphology. Cases 2 and 3 showed focal necrosis and focal rhabdoid morphology. Immunohistochemical staining showed negative expression of epithelial markers and deficient expression of SMARCA4. Furthermore, positivity for Syn (cases 1, 2 and 3) and SALL4 (cases 1 and 2) were observed. Mutant p53 expression occurred in four cases, resulting in strong and diffuse staining of p53 expression in cases 1, 2 and 4, and complete loss in case 3. The Ki67 proliferative index exceeded 80%. 25% (1/4, case 4) of cases had mismatch repair deficiency (dMMR). Two available cases (cases 1 and 3) were detected with SMRACA4 gene alterations. The response to neoadjuvant therapy was ineffective in case 1.ConclusionsGastric SMARCA4-UT is a rare entity of gastric cancer with a poor prognosis, predominantly occurs in male patients. The tumors are typically diagnosed at advanced stages and shows a solid architecture with undifferentiated morphology. Negative expression of epithelial markers and complete loss of SMARCA4 immunoexpression are emerging as a useful diagnostic tool for rare gastric SMARCA4-UTs.

Abstract PO2-24-08: GD3 Synthase is a Master Regulator of Wild-Type p53–Mediated Apoptosis and Mutant p53–Mediated Tumorigenesis

Abstract The tumor suppressor protein p53 is essential for maintaining genomic stability and regulating cellular responses to stress. TP53 mutations are common in breast cancer (BC) and other malignancies. We previously showed that ganglioside GD2 identifies BC stem-like cells (BCSCs) and that GD3 synthase (GD3S/ST8SIA1) is upregulated in breast tumors with TP53 mutations. Here, we demonstrate the direct involvement of p53 in the transcriptional regulation of GD3S in the GD2 biosynthesis pathway. Our results uncover a novel role of GD3S in inhibiting p53-mediated apoptosis and promoting mutant p53–induced tumor initiation. To investigate the p53-mediated regulation of GD3S expression, we used the TCGA and METABRIC datasets and examined GD3S mRNA expression in breast tumors with different p53 mutation status. GD3S expression was significantly upregulated in BC patients with hotspot (HS) p53 mutations compared to those with wild-type (WT) p53 or non-HS p53 mutations (P< 0.0001). Immuno-histochemical analysis of GD3S and p53 in FFPE primary tumor tissues from BC patients (n=84) with varying p53 expression status demonstrated that patients with HS p53 mutations had higher histological scores for GD3S than did patients with WT p53 (P< 0.0001) or non-HS p53 mutations (P=0.009). GD3S and p53 expression were significantly positively correlated in patients with HS p53 mutations (r=0.735; P=0.006) but not in patients with WT p53 (r=–0.09) or non-HS p53 mutations (r=0.14). Consistent with these patient data, BC cells harboring HS p53 mutations had significantly upregulated and positively correlated expressions of GD3S and p53 (n=8; r=0.85). Moreover, compared to those with WT p53, the cells with HS p53 mutations had substantially greater populations of GD2+ BCSCs (P=0.02) and GD3+ BCSCs (P=0.01). Subsequently, we investigated the regulatory role of p53 in the GD2 biosynthetic pathway by stabilizing WT p53 expression by nutlin-3a treatment in 4 BC cell lines and suppressing the expression of HS p53 mutants by p53 knockdown in their respective cell lines (n=4). In cell lines with WT p53, nutlin-3a significantly decreased GD3S expression and GD2 levels (P< 0.05 and P< 0.0001, respectively), suggesting that WT p53 inhibits GD3S expression. In cell lines with p53 mutations, p53 knockdown significantly inhibited GD3S expression. In both cells with WT p53 (MCF7 and ZR751) and cells with HS p53 mutations (Hs578T and BT549), the stable overexpression of GD3S effectively suppressed apoptosis even when WT p53 was stabilized or HS p53 mutant expression was depleted. Consistent with these results, in mice bearing MCF7 cell–derived xenografts, the overexpression of GD3S counteracted the effect of stabilized WT p53–mediated apoptosis and facilitated tumor growth (P< 0.0001). The results of a promoter-luciferase reporter assay demonstrated that nutlin-3a reduced GD3S promoter activity in a dose-dependent manner in MCF7 and ZR751 cells (P< 0.0001), whereas doxycycline (1µM) significantly reduced GD3S promoter activity in Hs578T and BT549 cells with inducible p53 knockdown (P< 0.001). ChIP-qPCR analysis confirmed specific enrichment of WT p53 at the 300-bp upstream regions and additional enrichment of HS p53 mutants at the downstream regions of the GD3S promoter, indicating that WT p53 and HS p53 mutations have distinct promoter regulation patterns. In summary, our study reveals that GD3S has a previously unknown anti-apoptotic function in BC, in that it helps attenuate p53-mediated apoptosis while activating tumor-promoting pathways that operate independently of p53. Citation Format: Vivek Anand, FOUAD EL-DANA, JENNY BORGMAN, MICHAEL ANDREEFF, Venkata Lokesh Battula. GD3 Synthase is a Master Regulator of Wild-Type p53–Mediated Apoptosis and Mutant p53–Mediated Tumorigenesis [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 PO2-24-08.

Abstract LB048: Unleashing the power of p53 mRNA therapeutics to suppress proliferation of p53 mutant tumors

Abstract The p53 protein, recognized as the guardian of the genome, plays a pivotal role in suppressing tumor formation. The TP53 gene, which encodes the p53 protein, is commonly subject to mutations and deletions in many cancer types resulting in loss of tumor suppressor activity. A significant proportion of patients diagnosed with lung, pancreatic, ovarian, and head and neck cancers exhibit the expression of mutant p53 in their tumors, correlating with unfavorable prognosis and survival outcomes.This study endeavors to assess the efficacy of therapeutic tumor suppressive mRNA which induces expression of wild-type p53 protein across diverse cancer types. Optimization of the 5’ and 3’ untranslated regions (UTRs) and the 5’ cap has been undertaken to enhance the efficient expression of p53 mRNA. The growth inhibitory potential of p53 mRNA therapy has been evaluated across p53 mutant cancer cell lines representing various cancer origins, along with normal or p53 wild-type cancer cell lines. We have substantiated that the p53 mRNA therapeutics can selectively inhibit the proliferation of p53 mutant cancer cells. Furthermore, we have confirmed that p53 mRNA treatment upregulated modulator of apoptosis (PUMA) and B-cell translocation gene 2 (BTG2) and cell cycle arrest via p21 upregulation. In vivo efficacy assessments of the lipid nanoparticle (LNP)-encapsulated p53 mRNA have been conducted in lung, pancreatic, and ovarian cancer xenograft models. Both regional intratumoral (i.t) and systemic intravenous (i.v) administrations of the p53 mRNA therapeutics have shown substantial suppression of tumor growth, leading to prolonged mouse survival. These results underscore the potential of the p53 mRNA therapeutics as a promising avenue for targeted cancer treatment, offering insights into the selective inhibition of p53 mutant cancer cells. Citation Format: Yong Ho Heo, Seung-Hyun Shin, Youngjin Han, Chang Gyu Lim, Innah Kim, Ji Hee Lee, Gunwoo Lee, Seongju Jeong, Yunjae Kim, Jooyun Byun, Daejin Kim, In Young Choi. Unleashing the power of p53 mRNA therapeutics to suppress proliferation of p53 mutant tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB048.

Abstract 3157: The crosstalk between STAT3 and p53/ERK signaling regulates brain metastasis

Abstract Brain metastasis (BM) affects approximately 10% of cancer patients with metastatic disease, representing a major cause of morbidity and mortality. BM is a complex multi-step process involving various immune checkpoint proteins. Mitogen-activated protein kinase (MAPK), particularly extracellular signal-regulated kinases 1/2 (ERK1/2), and signal transducer and activator of transcription 3 (STAT3) are implicated in tumorigenesis and are critical upstream regulators of Programmed Death Ligand 1 (PD-L1) expression, a common immunotherapy target. Tumor suppressor p53 is shown to regulate STAT3 and ERK1/2 signaling, which are dysregulated in various malignancies. We hypothesize that p53 along with STAT3 and ERK1/2 play a critical role in the initiation and maintenance of BM. Twenty-six BM tumors with various primary sites of origin were used following IRB guidelines. pSTAT3Tyr705, pERK1/2Thr202/Tyr204, mutant p53 (p53mt), and PD-L1 expression was determined by immunohistochemistry. Gene expression analysis of BM was performed on a cDNA microarray. Human brain metastatic breast cancer cells (MDA-MB-231) were treated with STAT3 inhibitor (NSC74859) or MAPK inhibitor (U0126) in regular or astrocytic media to determine cell proliferation and migration by MTT assay and scratch-wound, respectively. ERK1/2 signaling pathway status was determined by Western blotting. Results demonstrated: 1) pSTAT3Tyr705 and pERK1/2Thr202/Tyr204 were expressed profusely at tumor margins, while p53mt was uniformly expressed throughout. 81% of BM expressed p53mt while 86% and 63% expressed pERK1/2Thr202/Tyr204 and pSTAT3Tyr705, respectively. Venn analysis displayed significant overlap between expression, with 62% overlap between p53mt and pERK1/2Thr202/Tyr204 and a 50% overlap between both pSTAT3Tyr705 and pERK1/2Thr202/Tyr204 with p53mt. Expression of PD-L1 was seen in a majority of BM tumors. 2) Gene expression analysis demonstrated alterations in 32 STAT3- and MAPK-associated genes; these included upregulation of stathmin-1 and stathmin-like 3, which control microtubule dynamics in STAT3-related cell migration, and changes in cytokine-related genes, suggesting altered immune responses. 3) Cell proliferation showed augmented growth in astrocytic media (p≤0.05) and was significantly decreased following treatment with NSC74850 or U0126 (p≤0.01). While migration showed a trend towards significance in reduction following NSC74859 (p=0.08), migration stagnated following U0126 treatment in astrocytic media (p≤0.01). 4) pERK1/2Thr202/Tyr204 expression was reduced following U0126 or NSC74859 treatment. These findings suggest activation of STAT3 and ERK1/2 promote BM and suppression of these pathways may lead to a reduction in cell viability and motility. Therefore, this provides compelling evidence for the use of STAT3 and ERK1/2 along with p53 as potential targets for immunotherapy in brain metastatic disease. Citation Format: Sabrina L. Zeller, Eris Spirollari, John V. Wainwright, Simon J. Hanft, Chirag D. Gandhi, Meena Jhanwar-Uniyal. The crosstalk between STAT3 and p53/ERK signaling regulates brain metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3157.

Novel oncogenic transcriptional targets of mutant p53 in esophageal squamous cell carcinoma.

Missense mutations in the DNA binding domain of p53 are observed frequently in esophageal squamous cell carcinoma (ESCC). Recent studies have revealed the potentially oncogenic transcriptional networks regulated by mutant p53 proteins. However, majority of these studies have focused on common "hotspot" p53 mutations while rarer mutations are poorly characterized. In this study, we report the characterization of rare, "non-hotspot" p53 mutations from ESCC. In vitro tumorigenic assays performed following ectopic-expression of certain "non-hotspot" mutant p53 proteins caused enhancement of oncogenic properties in squamous carcinoma cell lines. Genome-wide transcript profiling of ESCC tumor samples stratified for p53 status, revealed several genes exhibiting elevated transcript levels in tumors harboring mutant p53. Of these, ARF6, C1QBP, and TRIM23 were studied further. Reverse transcription-quantitative PCR (RT-qPCR) performed on RNA isolated from ESCC tumors revealed significant correlation of TP53 transcript levels with those of the three target genes. Ectopic expression of wild-type and several mutant p53 forms followed by RT-qPCR, chromatin affinity-purification (ChAP), and promoter-luciferase assays indicated the exclusive recruitment of p53 mutants-P190T and P278L, to the target genes leading to the activation of expression. Several functional assays following knockdown of the target genes revealed a significant suppression of tumorigenicity in squamous carcinoma cell lines. Rescue experiments confirmed the specificity of the knockdown. The tumorigenic effects of the genes were confirmed in nude mice xenograft assays. This study has therefore identified novel oncogenic targets of "non-hotspot" mutant p53 proteins relevant for ESCC besides validating the functional heterogeneity of the spectrum of tumor-specific p53 mutations.

Translating p53-based therapies for cancer into the clinic.

Inactivation of the most important tumour suppressor gene TP53 occurs in most, if not all, human cancers. Loss of functional wild-type p53 is achieved via two main mechanisms: mutation of the gene leading to an absence of tumour suppressor activity and, in some cases, gain-of-oncogenic function; or inhibition of the wild-type p53 protein mediated by overexpression of its negative regulators MDM2 and MDMX. Because of its high potency as a tumour suppressor and the dependence of at least some established tumours on its inactivation, p53 appears to be a highly attractive target for the development of new anticancer drugs. However, p53 is a transcription factor and therefore has long been considered undruggable. Nevertheless, several innovative strategies have been pursued for targeting dysfunctional p53 for cancer treatment. In mutant p53-expressing tumours, the predominant strategy is to restore tumour suppressor function with compounds acting either in a generic manner or otherwise selective for one or a few specific p53 mutations. In addition, approaches to deplete mutant p53 or to target vulnerabilities created by mutant p53 expression are currently under development. In wild-type p53 tumours, the major approach is to protect p53 from the actions of MDM2 and MDMX by targeting these negative regulators with inhibitors. Although the results of at least some clinical trials of MDM2 inhibitors and mutant p53-restoring compounds are promising, none of the agents has yet been approved by the FDA. Alternative strategies, based on a better understanding of p53 biology, the mechanisms of action of compounds and treatment regimens as well as the development of new technologies are gaining interest, such as proteolysis-targeting chimeras for MDM2 degradation. Other approaches are taking advantage of the progress made in immune-based therapies for cancer. In this Review, we present these ongoing clinical trials and emerging approaches to re-evaluate the current state of knowledge of p53-based therapies for cancer.

Nanoscale Metal-Organic Frameworks-Mediated Degradation of Mutant p53 Proteins and Activation of cGAS-STING Pathway for Enhanced Cancer Immunotherapy.

Activating cGAS-STING pathway has great potential to achieve effective antitumor immunotherapy. However, mutant p53 (mutp53), a commonly observed genetic alteration in over 50% of human cancer, will impede the therapeutic performance of the cGAS-STING pathway. Herein, multifunctional ZIF-8@MnO2 nanoparticles are constructed to degrade mutp53 and facilitate the cGAS-STING pathway. The synthesized ZIF-8@MnO2 can release Zn2+ and Mn2+ in cancer cells to induce oxidative stress and cytoplasmic leakage of fragmented mitochondrial double-stranded DNAs (dsDNAs). Importantly, the released Zn2+ induces variable degradation of multifarious p53 mutants through proteasome ubiquitination, which can alleviate the inhibitory effects of mutp53 on the cGAS-STING pathway. In addition, the released Mn2+ further increases the sensitivity of cGAS to dsDNAs as immunostimulatory signals. Both in vitro and in vivo results demonstrate that ZIF-8@MnO2 effectively promotes the cGAS-STING pathway and synergizes with PD-L1 checkpoint blockades, leading to remarkable regression of local tumors as well as distant metastases of breast cancer. This study proposes an inorganic metal ion-based nanoplatform to enhance the cGAS-STING-mediated antitumor immunotherapy, especially to those tumors with mutp53 expression.

Ninjurin 2, a Cell Adhesion Molecule and a Target of p53, Modulates Wild-Type p53 in Growth Suppression and Mutant p53 in Growth Promotion.

The nerve injury-induced protein 1 (NINJ1) and NINJ2 constitute a family of homophilic adhesion molecules and are involved in nerve regeneration. Previously, we showed that NINJ1 and p53 are mutually regulated and the NINJ1-p53 loop plays a critical role in p53-dependent tumor suppression. However, the biology of NINJ2 has not been well-explored. By using multiple in vitro cell lines and genetically engineered mouse embryo fibroblasts (MEFs), we showed that NINJ2 is induced by DNA damage in a p53-dependent manner. Moreover, we found that the loss of NINJ2 promotes p53 expression via mRNA translation and leads to growth suppression in wild-type p53-expressing MCF7 and Molt4 cells and premature senescence in MEFs in a wild-type p53-dependent manner. Interestingly, NINJ2 also regulates mutant p53 expression, and the loss of NINJ2 promotes cell growth and migration in mutant p53-expressing MIA-PaCa2 cells. Together, these data indicate that the mutual regulation between NINJ2 and p53 represents a negative feedback loop, and the NINJ2-p53 loop has opposing functions in wild-type p53-dependent growth suppression and mutant p53-dependent growth promotion.

Analyzing the Expression of MicroRNA-375 and its Target Gene p53 in Oral Squamous Cell Carcinoma and its Implication in Oral Carcinogenesis

Objective: Oral mucosal cancers are the 11th most common human malignancies worldwide with a five-year survival rate of ≤50%. The lacunae of reliable diagnostic and prognostic markers pose an enormous challenge to the timely identification and prediction of disease progression in oral cancer. MicroRNAs (miRNAs) are emerging molecular markers associated with cancer initiation, progression, and therapy. The present study evaluated the microRNA -375(miR-375) expression and its target p53 gene in Oral squamous cell carcinoma (OSCC) to validate its utility as a diagnostic marker of the disease. Patients and Methods: This case-control study targeted histopathologically diagnosed cases of OSCC. miR-375 was quantified from 22 cases of OSCC and corresponding control tissues using qRT-PCR. Mutant p53 expression in cases and controls was determined by subjecting the tissues to immunohistochemical Results: Significant downregulation of miR-375 was noted in OSCC tissues (68.1%) compared to the control tissues with a mean fold change of 83.9 (p<0.05). Significant downregulation of miR-375 was noted in Paan and tobacco chewing patients (77.8%). Men exhibited considerable downregulation compared to women (p<0.05). The miR-375 expression levels did not correlate with the patient’s age, location, size, nodal status, and histopathological grade of the tumor. About 63.6 % of OSCC tissues showed mutant p53 positivity. Mutant p53 expression was noted in 73.3% of miR-375 downregulated tumors. Smokers exhibited higher expression of mutant p53 contrary to non-smokers(p<0.00). P53 immunopositivity showed a correlation with tumor size, histopathological grade, and nodal metastasis. Conclusion: The findings of the study indicate that miR-375 downregulation may have a crucial effect on oral carcinogenesis by targeting p53. miR-375 should be further evaluated as a potential marker for oral cancer diagnosis.

Brain Metastases Are Regulated by Immuno-inflammatory Signaling Pathways Governed by STAT3, MAPK and Tumor Suppressor p53 Status: Possible Therapeutic Targets.

Brain metastasis (BM) is a complex multi-step process involving various immune checkpoint proteins. Mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinases 1/2 (ERK1/2), and signal transducer and activator of transcription 3 (STAT3) are implicated in tumorigenesis and are critical upstream regulators of Programmed Death Ligand 1 (PD-L1), an immunotherapy target. Tumor suppressor p53, dysregulated in cancers, regulates STAT3 and ERK1/2 signaling. This study examined the roles of STAT3, MAPK and p53 status in BM initiation and maintenance. Twenty-six BM, with various primary malignancies, were used (IRB-approved) to determine mutant p53 (p53mt), pSTAT3Tyr705, pERK1/2Thr202/Tyr204, and PD-L1 expression using immunohistochemistry. cDNA microarray was used for gene expression analysis. Brain-metastatic breast cancer cells (MDA-MB-231) were treated with STAT3 (NSC74859) or MAPK/ERK1/2 (U0126) inhibitors in regular or astrocytic media. ERK1/2 pathway was assessed using western blotting, and cell proliferation and migration were determined using MTT and scratch-wound assays, respectively. pSTAT3Tyr705 and pERK1/2Thr202/Tyr204 were expressed at tumor margins, whereas p53mt and PD-L1 were uniformly expressed, with significant overlap between expression of these proteins. Gene expression analysis identified alterations in 18 p53- and 32 STAT3- or MAPK-associated genes contributing to dysregulated immune responses and cell cycle regulation. U0126 and NSC74859 reduced pERK1/2Thr202/Tyr204 expression. Cell proliferation decreased following each treatment (p≤0.01). Migration stagnated following U0126 treatment in astrocytic media (p≤0.01). Activation of STAT3 and ERK1/2 promotes BM and provides compelling evidence for use of STAT3, ERK1/2 and p53 status as potential immunotherapeutic targets in BM.

Relationship between PIWIL1 gene polymorphisms and epithelial ovarian cancer susceptibility among southern Chinese woman: a three-center case–control study

ObjectiveTo investigate the potential correlation between piwi-like RNA-mediated gene silencing 1 (PIWIL1) polymorphisms and susceptibility to epithelial ovarian cancer (EOC).MethodsA case–control study was conducted to evaluate the susceptibility of EOC using multinomial logistic regression analysis. The study analyzed the relationship between five functional single nucleotide polymorphisms (SNPs) in the PIWIL1 gene and EOC risk. Genotyping of 288 cases and 361 healthy samples from South China was identified using a TaqMan assay. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the relationship between the five selected SNPs and EOC susceptibility.ResultsAmong the five SNPs analyzed, the rs10848087 G > A and rs7957349 G > C variants significantly increased the susceptibility of EOC, rs10773771 C > T was associated with a decreased risk of EOC, while the rs35997018 and rs1106042 variants were not in Hardy–Weinberg equilibrium (p < 0.05). The rs10848087 G > A was significantly associated with increased risk of EOC in individuals with metastasis, FIGO stage I and III, low and high pathological grade, tumor numbers ≤ 3 and > 3, tumor size > 3 cm and ≤ 3 cm, pregnant more than 3 times, pre-menopausal status, and strong positive expression of ER (estrogen receptor), PR (progesterone receptor), PAX8 (paired-box 8), wild-type p53 (tumor protein 53), WT1 (Wilm’s tumor gene), P16 (cyclin-dependent kinase inhibitor 2A). In addition, rs10848087 G > A enhanced the EOC risk of cases with negative/mild positive expression of wild p53 and Ki67, and with or without mutant p53 expression. The rs7957349 G > C variant was linked to an increased risk of EOC in subgroups with certain characteristics, including age equal or less than 53 years, metastasis, clinical stage I, low pathological grade, tumor number, tumor size, pregnant times, post-menopause, pre-menopause, and strong positive expression of wild p53 and Ki67 (Antigen identified by monoclonal antibody Ki-67), as well as without mutant p53 expression. The rs10773771 CT/TT alleles were identified to have a protective effect on EOC in women aged 53 years or older, as well as in cases with metastasis, advanced clinical stage, high pathological grade, multiple tumors, tumor size equal to or less than 3 cm, history of pregnancy, post-menopausal status, and strong positive expression of ER, PR, wild-type p53, PAX8, WT1, P16, and Ki67. Furthermore, rs10773771 CT/TT also showed a protective effect in patients with negative or mildly positive expression of PR, PAX8, wild-type p53, WT1, and P16, as well as positive expression of mutant p53. Compared to the reference haplotype GCG, individuals harboring haplotypes GTG were found to have a significantly decreased susceptibility to EOC. PIWIL1 was significantly expressed in the thyroid, pituitary, and adrenal glands with rs7957349 CC alleles.ConclusionsPIWIL1 rs10848087 and rs7957349 were associated with increased risk of EOC, while rs10773771 may have a protective effect against EOC. These genetic variants may serve as potential biomarkers for EOC susceptibility in the South China population.

Hepatitis C virus may accelerate breast cancer progression by increasing mutant p53 and c-Myc oncoproteins circulating levels

BackgroundHepatitis C virus (HCV) was reported to relate to polymorphous and frequent extrahepatic manifestation. Despite the limited studies, HCV viral oncoproteins may be implicated in breast cancer (BC) tumor aggressiveness. In a trial to elucidate a mechanistic link, this study aimed to investigate a mutant p53 and c-Myc oncoprotein expression levels in BC patients with and without HCV infection.MethodsA total of 215 BC patients (119 infected and 96 non-infected with HCV) were collected. ELISA was used for detection of anti-HCV antibodies, mutant p53, c-Myc, HCV-NS4, CEA, CA 125, and CA-15.3.ResultsHCV infection was related to BC late stages, lymph-node invasion, distant metastasis, high grades, and large size. HCV-infected patients had a significantly (P < 0.05) higher WBCs, ALT and AST activity, bilirubin CEA, CA125 and CA15.3 levels, and reduced hemoglobin, albumin, and RBCs count. Regardless of tumor severity, HCV infection was associated with significant elevated levels of mutant p53 (22.5 ± 3.5 µg/mL; 1.9-fold increase) and c-Myc (21.4 ± 1.8 µg/mL; 1.5-fold increase). Among HCV-infected patients, elevated levels of p53 and c-Myc were significantly correlated with elevated tumor markers (CEA, CA 125, and CA15.3) and HCV-NS4 levels.ConclusionsThis study concluded that HCV infection may be accompanied with BC severity behavior and this may be owing to elevated expression of mutant p53 and c-Myc oncoproteins.

Mutant p53 Drives the Development of Myelodysplastic Syndromes Via Dysregulating Pre-mRNA Splicing in Hematopoietic Stem and Progenitor Cells

Despite the clinical importance of TP53 mutations, to date there have been no studies on the functional impact of TP53 mutations on the initiation and progression of MDS. We found that heterozygous p53 mutant mice ( p53R248W/+) show extended survival and died within 15-20 months after birth. p53 mutant mice had hypercellular bone marrow and displayed cytopenia, thrombocytopenia, and anemia. Approximately 60% of p53R248W/+ mice developed MDS based upon pathological analysis of bone marrow (BM) and peripheral blood smears, while the remaining p53R248W/+ mice developed lymphoma and sarcoma. We further showed that mutant p53-driven MDS are transplantable. Thus, we have generated a mouse model of MDS that has some features of human MDS with TP53 mutations. To understand how mutant p53 drives MDS development, we performed RNA-seq studies to compare gene expression in hematopoietic stem and progenitor cells (HSPCs). GSEA analysis revealed that spliceosome genes were significantly downregulated in middle-aged p53 R248W/+ HSPCs compared to age-matched p53 +/+ HSPCs. We confirmed that the expression of splicing factors, such as Prpf3 and Prpf4, was significantly downregulated in middle-aged p53 R248W/+ HSPCs. We conducted alternative splicing analysis utilizing MISO (Mixture of Isoforms) algorithm to identify differences in exon inclusion ratio between WT and mutant HSPCs. We observed differential splicing of all classes of alternative splicing events, including Cassette Exons (CE), Competing 5′ and 3′ splice sites (A5' or A3'SS), Mutually Exclusive Exons (MXE), and Retained Introns (RI) in p53 R248W/+ cells compared to that of the WT HSPCs. Notably, we found that murine p53 mutant HSPCs exhibited aberrant splicing of key regulators of NFκBactivation, such as USP15. USP15 overexpression promotes NFκB expression through inhibiting its ubiquitination, whereas NFκB promotes USP15 expression. p53 mutant HSPCs tend to skip exon 7 and express high levels of short isoform of Usp15. The short isoform of Usp15, but not the long isoform of Usp15, activates NFκB in HSPCs, manifested by increased phosphorylation of p65. To determine the impact of mutant p53 on pre-mRNA splicing in human HSPCs, we ectopically expressed GFP or p53 R248W in human cord blood CD34 + cells and performed RNA-seq in transduced cells (GFP +). Human HSPCs expressing mutant p53 displayed alterations in pre-mRNA splicing compared to HSPCs expressing GFP. We found that human HSPCs expressing mutant p53 display aberrant splicing in key regulator of NFκB such as IKBKE (Inhibitor of nuclear factor kappa-B kinase subunit epsilon). Human HSPCs expressing mutant p53 tend to include exon 7 and express high levels of long isoform of IKBKE. The long isoform of IKBKE, but not the short isoform of IKBKE, activates NFκB in human HSPCs. Many proinflammatory cytokine genes are NFκB targets and we observed increased levels of pro-inflammatory cytokines, including IL-1β and IL-6, in the BM of middle-aged p53 mutant mice. Notably, we observed increased levels of IL-1β and IL-6 in the BM of MDS or AML patients with TP53 mutations. TP53 mutations co-occur with splicing factor mutations in MDS. To determine whether TP53 and SRSF2 mutations cooperate in pathogenesis of MDS, we have generated p53 R248W/+SRSF2 P95H/+ mice. We found that the survival of recipient mice repopulated with p53 R248W/+SRSF2 P95H/+ BM cells was significantly decreased compared to recipients repopulated with WT, p53 R248W/+, or SRSF2 P95H/+ BM cells. All recipient mice repopulated with p53 R248W/+SRSF2 P95H/+ BM cells died within 6 months and developed MDS or leukemia. Thus, we demonstrate that TP53 and SRSF2 mutations cooperate in MDS or leukemia development. In summary, we discovered that mutant p53 dysregulates pre-mRNA splicing in key regulators of inflammatory response during aging, thereby generating a chronic inflammatory microenvironment to drive MDS pathogenesis.

An ultrathin Zn-based layered double hydroxides augment degradation of mutant p53 to improve tumor therapy

Tumor protein 53 (Tp53), a key regulator of suppressor genes, is commonly mutated in numerous malignant diseases. Consequently, elimination mutant protein 53 (mutp53) represents an appealing strategy for treating mutp53-related tumors. However, the treatment of these mutations remained challenging due to its formidable limitations. In this study, by loading glucose oxidase (GOX) into Zn-based layered double hydroxides (Zn-LDH) interlayer, a pH-responsive ultrathin nanotherapeutic platform (Zn-LDH@GOX) was created to suppress tumors growth by degrading mutp53. Upon exposure to the acidic environment of lysosomes, the lattice structure of Zn-LDH@GOX was partially disrupted, leading to the release of Zn2+ ions and GOX into the cytoplasm. The increased intracellular concentration of Zn2+ facilitated the restoration of wild-type protein 53 (wtp53) conformation, which in turn degraded mutp53 through activated autophagic pathways. Meanwhile, GOX-induced Heat Shock Protein 90 (HSP90) disruption resulted in the liberation of mutp53 from the HSP90/mutp53 complex and reactivated its degradation via the ubiquitination-mediated proteasomal pathway. In vitro and in vivo experiments confirmed the significant suppression of mutp53 expression and inhibition of tumor growth by Zn-LDH@GOX. Our work offers a novel pH-responsive nanotherapeutic platform with immense potential for mutp53 tumor-specific therapy.

Prognostic Value of Vimentin in Triple Negative Breast Cancer Patients Depends on Chemotherapy Regimen and p53 Mutant Expression.

To determine the prognostic value of vimentin in triple negative breast cancer (TNBC) patients, specifically in relation to chemotherapy regimen and p53 mutant expression. We retrospectively analyzed the association of pre-treatment tumor expression of vimentin with 48-month overall survival (OS) of 72 all stages TNBC patients diagnosed between 2014 and 2018 in relation to chemotherapy regimen and expression of p53 mutant. Vimentin and p53 mutant expressions were examined using immunohistochemistry. Analysis was conducted on all patients collectively, then repeated on two cohorts divided according to the chemotherapy regimen. Sub-analysis was performed to determine the effect of p53 mutant expression on the prognostic value of vimentin. Vimentin was expressed in 43.1% of patients and was not associated with clinicopathologic characteristics. Vimentin was associated with improved 48-month OS in all patients in univariate analysis but not significant in multivariate analysis. When analyzed according to chemotherapy regimen, vimentin was independently associated with improved 48-month OS in patients receiving non-platinum-based chemotherapy (80% vs 15.8%; HR: 0.17, 95% CI: 0.05-0.58, p: 0.005). Other independent prognostic factors include T (HR: 6.18, 95% CI: 1.38-27.7, p: 0.017) and M (HR: 5.64, 95% CI: 1.2-26.33, p: 0.028). On subanalysis, vimentin was significantly associated with improved 48-month OS in patients expressing p53 mutant (69.2% vs 22.2%, p: 0.006) but was not significant in patients not expressing p53 mutant. Vimentin expression was independently associated with improved 48-month OS in TNBC patients treated with non-platinum-based chemotherapy. Expression of p53 mutant significantly affected the prognostic value of vimentin.

Clinicopathological characteristics of endometrial carcinomas according to DNA mismatch repair protein status

DNA mismatch repair protein deficiency (MMRd) in endometrial carcinoma is associated with the risk of Lynch syndrome and response to immune checkpoint inhibitors. It is also related to microsatellite instability and corresponds to a molecular subtype of endometrial tumor with an unclear prognosis. Here, we evaluated the clinicopathological characteristics and prognosis of 312 consecutive endometrial carcinoma cases submitted to complete surgical staging at a single institution. We compared MMRd and mismatch repair protein–proficient (MMRp) tumors and examined the effects of the MMR protein loss type (MLH1/PMS2 vs. MSH2/MSH6) and influence of L1CAM and p53 expression. The median follow-up period was 54.5 (range, 0–120.5) months. No difference was observed between MMRd [n = 166 (37.2%)] and MMRp [n = 196 (62.8%)] cases in terms of age, body mass index, FIGO stage, tumor grade, tumor size, depth of myometrial infiltration, or lymph node metastasis. More MMRd than MMRp tumors had endometrioid histology (87.9% vs. 75.5%) and despite MMRd had more lymphovascular space invasion (LVSI; 27.2% vs. 16.9%), they presented fewer recurrences and no difference in lymph node metastasis and disease-related death. Relative to those with MLH1/MSH6 loss, tumors with MSH2/MSH6 loss were diagnosed at earlier FIGO stages, were smaller, and had less ≥50% myometrial invasion, LVSI and lymph node metastasis. Outcomes, however, did not differ between these groups. L1CAM positivity and mutation-type p53 expression were more common in MMRp than in MMRd tumors and did not differ between the MLH1/PMS2 and MSH2/MSH6 loss groups. In the entire cohort, L1CAM and mutation p53 expression were associated with worse prognosis, but only non-endometrioid histology, FIGO stage III/IV, and deep myometrial infiltration were significant predictors. In the subgroup of endometrioid carcinomas, only FIGO stage III/IV was associated with poor outcomes. The risk of lymph node metastasis was associated with tumor size, non-endometrioid histology, and multifocal LVSI. For MMRd tumors, only tumor size and myometrial invasion depth were predictive of lymph node involvement. In our cohort, MMRd tumors were associated with greater recurrence-free, but not overall, survival. The precise identification of MMRd status, present in a substantial proportion of endometrial cancer cases, is a challenge to be overcome for proper patient management. MMRd status serves as a marker for Lynch syndrome, and a significant number of these tumors are high risk and candidate to immunotherapy.