MiRNA-136-5p Sensitizes Liver Cancer Cells to Docetaxel by Targeting P53 and Enhances Cell Migration

We aimed to explore whether microRNA (miRNA)-136-5p modulates P53 expression, and affects the efficacy of docetaxel treatment for liver cancer. miRNA array screened the differentially expressed miRNAs in biopsy tissues of liver cancer patients, and the expression of miR-136-5p and P53 in tissues and cells by RT-PCR. Following docetaxel treatment, through increased- and decreased-function method, we detected the impact of the miRNA on cell progression, as well as the sensitivity of docetaxel through MTT assay and colony formation experiment. The correlation between miR-136-5p and P53 was evaluated. The expression of miR-136-5p in liver cancer cells is up-regulated, which is consistent with the results of bioinformatics analysis. Further, miR-136-5p overexpression promoted cell proliferation and migration, and sensitized liver cancer cells to docetaxel. Interestingly, P53 was indicated to bind to miR-136-5p, and P53 participated in the up-regulation of MMP10 induced by miR-136-5p. miR-136-5p enhances the sensitivity to docetaxel in liver cancer and thus could be a biomarker for the treatment against liver cancer.

Reciprocal modulation of long noncoding RNA EMS and p53 regulates tumorigenesis

p53 plays a central role in tumor suppression. Emerging evidence suggests long noncoding RNA (lncRNA) as an important class of regulatory molecules that control the p53 signaling. Here, we report that the oncogenic lncRNA E2F1 messenger RNA (mRNA) stabilizing factor (EMS) and p53 mutually repress each other’s expression. EMS is negatively regulated by p53. As a direct transcriptional repression target of p53, EMS is surprisingly shown to inhibit p53 expression. EMS associates with cytoplasmic polyadenylation element-binding protein 2 (CPEB2) and thus, disrupts the CPEB2–p53 mRNA interaction. This disassociation attenuates CPEB2-mediated p53 mRNA polyadenylation and suppresses p53 translation. Functionally, EMS is able to exert its oncogenic activities, at least partially, via the CPEB2–p53 axis. Together, these findings reveal a double-negative feedback loop between p53 and EMS, through which p53 is finely controlled. Our study also demonstrates a critical role for EMS in promoting tumorigenesis via the negative regulation of p53.

Transient Exposure of Endothelial Cells to Doxorubicin Leads to Long-Lasting Vascular Endothelial Growth Factor Receptor 2 Downregulation

Doxorubicin (Dox) is an effective antineoplastic drug with serious cardiotoxic side effects that persist after drug withdrawal and can lead to heart failure. Dysregulation of vascular endothelium has been linked to the development of Dox-induced cardiotoxicity, but it is unclear whether and how transient exposure to Dox leads to long-term downregulation of Endothelial Vascular Endothelial Growth Factor Receptor type2 (VEGFR2), essential for endothelial cells function. Using an in vitro model devised to study the long-lasting effects of brief endothelial cells exposure to Dox, we show that Dox leads to sustained protein synthesis inhibition and VEGFR2 downregulation. Transient Dox treatment led to the development of long-term senescence associated with a reduction in VEGFR2 levels that persisted days after drug withdrawal. By analyzing VEGFR2 turnover, we ruled out that its downregulation was depended on Dox-induced autophagy. Conversely, Dox induced p53 expression, reduced mTOR-dependent translation, and inhibited global protein synthesis. Our data contribute to a mechanistic basis to the permanent damage caused to endothelial cells by short-term Dox treatment.

Correlation between p53 and Mdm2 expression with histopathological parameters in cattle squamous cell carcinomas

Background and Aim: Squamous cell carcinoma (SCC) is the most common form of carcinoma in cattle. Histopathological grading systems have been utilized over several decades for estimating the malignancy of cattle SCCs. This study aimed to detect p53 and Mdm2 expression in different SCC cases in cattle and correlate their expression with the SCC histopathological grading. Materials and Methods: Cattle SCC cases were collected at the Veterinary Teaching Hospital in Nineveh. The SCC grading system categorized the cases histologically based on their differentiation grade into three groups: Well, moderately, and poorly differentiated. The SCC cases were subsequently verified for p53 and Mdm2 immunoexpression. Results: Fourteen of 16 examined cattle SCC samples tested positive for p53 expression. Moreover, 15 out of the 16 SCC samples tested positive for Mdm2 expression. The increased immunoreactivity of both p53 and Mdm2 was associated with a poor histological grading of the cattle SCC. There is a positive correlation between the nuclear expression of p53 and Mdm2, and the degree of differentiation and the number of mitotic figures in the examined cattle SCC samples. Conclusion: Our results demonstrate an increased p53 and Mdm2 expression in cattle SCC cases characterized by poor histopathological grading, thus suggesting an essential role of these molecules in the development of moderately and poorly differentiated SCC in cattle.

Clinical and Genetic Characteristics of Thymoma Patients With Autoimmune Hepatitis and Myocarditis

BackgroundOur study investigated a special series of thymoma with autoimmune hepatitis and myocarditis and tried to reveal the gene expression profiles of this series of thymoma.MethodsFrom 2011 to 2019, a total of 13 special thymoma patients presented with autoimmune hepatitis and myocarditis, accounting for about 1.26% of thymoma patients undergoing surgery in Beijing TongRen Hospital. Clinical data were retrospectively collected. All samples were harvested during surgical procedures, and analyzed to identify changes in gene expression using the CapitalBio mRNA microarray analysis, the Whole exome sequencing analysis (WES), qPCR and immunohistochemistry (IHC) tools.ResultsAfter surgery, patient symptoms were relieved gradually. Levels of lactate dehydrogenase (LDH), creatine kinase MB (CK-MB), aspartate transaminase (AST), and alanine amiotransferase (ALT) increased to some extent within 1 to 3 months after surgery, and fluctuated, and then, gradually decreased close to normal within 6 months after surgery. Enrichment analysis of Kyoto Genome and Genome Encyclopedia (KEGG) pathway was performed and enrichment results were visualized. It indicated that gene expression of 5 signaling pathways, including cell cycle and p53 signaling pathway, were generally abnormal. P53 expression was up-regulated in all tumor tissues. However, IHC and qPCR analysis showed that there was no significant difference in p21 expression between normal and tumor tissue. Results of WES showed that only one driver gene-MDM4 amplified 4 fold in 53.2% thymoma cells. Further qPCR and IHC analysis confirmed the up-regulation of the expression of p53 and mdm4 in 13 thymoma patients with autoimmune hepatitis and myocarditis.ConclusionOur study reveals the clinical and genetic characteristics of thymoma patients with autoimmune hepatitis and myocarditis. For this special category of thymoma, the up-regulation of p53 and mdm4 plays an important role in the occurrence of thymoma and autoimmune hepatitis/myocarditis.

Dysregulated TP53 Among PTSD Patients Leads to Downregulation of miRNA let-7a and Promotes an Inflammatory Th17 Phenotype

Post-traumatic stress disorder (PTSD) is a psychiatric disorder and patients diagnosed with PTSD often express other comorbid health issues, particularly autoimmune and inflammatory disorders. Our previous reports investigating peripheral blood mononuclear cells (PBMCs) from PTSD patients showed that these patients exhibit an increased inflammatory T helper (Th) cell phenotype and widespread downregulation of microRNAs (miRNAs), key molecules involved in post-transcriptional gene regulation. A combination of analyzing prior datasets on gene and miRNA expression of PBMCs from PTSD and Control samples, as well as experiments using primary PBMCs collected from human PTSD and Controls blood, was used to evaluate TP53 expression, DNA methylation, and miRNA modulation on Th17 development. In the current report, we note several downregulated miRNAs were linked to tumor protein 53 (TP53), also known as p53. Expression data from PBMCs revealed that compared to Controls, PTSD patients exhibited decreased TP53 which correlated with an increased inflammatory Th17 phenotype. Decreased expression of TP53 in the PTSD population was shown to be associated with an increase in DNA methylation in the TP53 promotor region. Lastly, the most significantly downregulated TP53-associated miRNA, let-7a, was shown to negatively regulate Th17 T cells. Let-7a modulation in activated CD4+ T cells was shown to influence Th17 development and function, via alterations in IL-6 and IL-17 production, respectively. Collectively, these studies reveal that PTSD patients could be susceptible to inflammation by epigenetic dysregulation of TP53, which alters the miRNA profile to favor a proinflammatory Th17 phenotype.

Targeting Post-Translational Regulation of p53 in Colorectal Cancer by Exploiting Vulnerabilities in the p53-MDM2 Axis

The role played by the key tumor suppressor gene p53 and the implications of p53 mutations for the development and progression of neoplasia continue to expand. This review focuses on colorectal cancer and the regulators of p53 expression and activity identified over the past decade. These newly recognized regulatory mechanisms include (1) direct regulation of mouse double minute 2 homolog (MDM2), an E3 ubiquitin-protein ligase; (2) modulation of the MDM2-p53 interaction; (3) MDM2-independent p53 degradation; and (4) inhibition of p53 nuclear translocation. We positioned these regulatory mechanisms in the context of p53 missense mutations, which not only evade canonical p53 degradation machinery but also exhibit gain-of-function phenotypes that enhance tumor survival and metastasis. Lastly, we discuss current and potential therapeutic strategies directed against p53 mutant-bearing tumors.

Treatment tactics of new NET G3 subgroup in first line of therapy

Considering the fact that the group of neuroendocrine carcinomas (NECs) grade 3 is heterogenous, in the year of 2017 a new subgroup of welldifferentiated neuroendocrine tumors grade 3 (NETs G3) was described. NETs G3 are tumors with more favorable prognosis and less sensitive to platinum-based chemotherapy regimens than NECs, they also have peculiar morphogenetical qualities: lower ki‑67 index (mean 35.0 %), higher somatostatin receptors expression, absence of DAXX/ATRX/MEN 1 genes mutation, p53 expression in the absence of TP53 mutation. Nowadays treatment standard for NETs G3 subgroup is still remain unclear due to lack of prospective clinical trials. At the same time taking in note historical retrospective data, NETs G3 should be treated in line with NETs G1/G2 and only patients with higher ki‑67 index can be treated as NECs with platinum-based chemotherapy. In our non-randomised phase II prospective trial, we accessed the efficacy of different chemotherapy regimens in combination with somatostatin analogues in new NETs G3 subgroup. 153 patients with IHC-confirmed neuroendocrine neoplasm diagnose were included: NETs G3 n = 53 mean ki‑67 36.4 % [21.0–60.0 %], NETs G2 n = 50 mean ki‑67 15.7 % [2.1–20.0 %], NECs n = 50 mean ki‑67 69.0 % [38.0–96.0 %]). Patients from NETs G3 subgroup received 4 chemotherapy regimens: Aranose (n = 19), Aranose (arabinopiranosilmethyl nitrosocarbamide, ALK, – cytostatic drug with a chemical structure similar to Streptozotocin and Nitrosomethylurea, approved in Russian Federation for melanoma and welldifferentiated neuroendocrine tumors treatment), XELOX (n = 8), TemCAP (n = 11), EP/EC (n = 10). mPFS in Aranose-subgroup was 19.3 ± 5.9 months (95 % CI: 7.7–30.8), in XELOX – 10.8 ± 3.6 months (3.7–17.8), in TemCAP – 14.8 ± 4.2 months (6.6–23.1) and in platinum-based regimens – 4.4 ± 1.9 months (0.6–8.2) (p = 0.01). DCR in Aranose subgroup was 73.6 % and ORR – 36.8 %, PDR – 21.1 %, in XELOX subgroup ORR was 62.5 %, SDR was 50.0 % and PDR – 25.0 %, in TemCAP subgroup DCR was 63.6 %, ORR – 9.1 %, PDR – 18.2 % and in platinum-based regimens SDR was 40.0 %, PDR – 50.0 % (p = 0.05).

Salivary Exosome Proteomics and Bioinformatics Analysis in 7,12-Dimethylbenz[a]anthracene-induced Oral Cancer with Radiation Therapy—A Syrian Golden Hamster Model

Exosomes carry cellular proteins and contain molecules that can be potential biomarkers of diseases. This study used a Syrian golden hamster model of 7,12-dimethylbenz[a]anthracene (DMBA)-induced oral squamous cell carcinoma with radiation therapy to exclude the confounding factors that may affect outcomes in clinical studies, and re-examine the role of exosomes during tumorigenesis. We used data-dependent acquisition-based quantitative proteomics and bioinformatics analyses and found unique proteins present (desmocollin-2) or absent (Glucagon-cAMP-PKA-CREB pathway-related proteins) in the salivary exosomes of the pre-radiation DMBA-treated group (PreD). Comparing our data to other studies, salivary exosomes in the PreD group were found carrying proteins that the tumor mass does not express and lacking the proteins needed during tumorigenesis. Immunohistochemistry staining showed p53 expression but a negative apoptotic signal in the PreD tumor tissue. We thus suggest that inhibition of desmocollin-2 expression in tumor tissue may impede the activation of cell apoptosis. However, both the origin of the salivary exosomes and main role of the salivary exosome proteins should be clarified in future studies.

Evaluation of Cyclooxygenase-2 and p53 Expression in Pterygium Tissue Following Preoperative Intralesional Ranibizumab Injection

Introduction: Overexpression of vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2), and p53 are the postulated aetiopathogenesis in pterygium. VEGF is responsible for the induction of COX-2 expression, whereas p53 plays an important role in the regulation of VEGF. This study aimed to evaluate the immunohistochemistry of COX-2 and p53 expressions from excised pterygium tissue from patients who received intralesional ranibizumab (anti-VEGF) injection 2 weeks prior to pterygium surgery.Materials and Methods: An interventional comparative study involving patients presenting with primary pterygium was conducted between September 2015 and November 2017. The patients were randomized into either the intervention or control group. Patients in the intervention group were injected with intralesional ranibizumab (0.5 mg/0.05 ml) 2 weeks prior to surgery. Both groups underwent pterygium excision followed by conjunctival autograft. Immunohistochemistry staining was performed to evaluate COX-2 and p53 expressions in the excised pterygium tissue.Results: A total of 50 patients (25 in both the intervention and control groups) were recruited. There were 34 (68%) patients with grade III pterygium and 16 (32%) patients with grade IV pterygium. There was statistically significant difference in reduction of COX-2 expression in the epithelial layer [84.0% (95% CI: 63.9, 95.5)] (p = 0.007) and stromal layer [84.0% (95% CI: 63.9, 95.5)] (p < 0.001) between intervention and control groups. There was no significant difference in the reduction of p53 expression between the two groups.Conclusion: This study demonstrated the possible use of intralesional anti-VEGF treatment prior to pterygium excision as a potential future modality of adjunctive therapy for pterygium surgery.