MDM2 Expression Research Articles

The impact of ERP29 on the progression of pharyngeal squamous cell carcinoma

ERP29 gene encodes a chaperone protein critical for protein folding and secretion. Previous study linked ERP29 inhibition to an elevated risk of pharynx squamous cell carcinoma (PSCC) and reduced patients’ survival. However, ERP29 role in PSCC progression remains unknown. Here, we investigated ERP29 impact on PSCC progression in cisplatin (CDDP)-sensitive (FaDu and LAU-2063), CDDP-treated (FaDu-CDDP), and CDDP-resistant (FaDu-R) cells. ERP29 silencing decreased necrosis and increased migration in CDDP-sensitive, treated, and resistant cells; and reduced E-cadherin and increased vimentin immunoexpression in CDDP-sensitive 3D-spheroids. During CDDP treatment, ERP29 silencing enhanced proliferation. In CDDP-sensitive cells, ERP29 silencing upregulated genes associated with WNT, MAPK, and PI3K/AKT signaling pathways while downregulating CASP9 expression. During CDDP treatment, ERP29 silencing downregulated MDM2 and CASP9 expression. In CDDP-resistant cells, ERP29 silencing upregulated SOS1, MAPK1, AKT1, ITGAV, and CCNE1, while downregulating KRAS, JUN, MDM2, and CASP9 expression. In addition, inhibition of microRNA miR-4421 increased ERP29 expression and decreased MAPK1, AKT1, and JUN expression in CDDP-sensitive cells, as well as SOS1, MAPK1, AKT1, and ITGAV in CDDP-resistant cells. Lower ERP29 and higher miR-4421 expressions were predictive of poor survival, suggesting a potential therapeutic use for miR-4421 inhibitors. Upon validation, these findings may contribute to targeted therapies for PSCC based on ensuring ERP29 expression.

Immunohistochemical Expression of MDM2, Bcl-2, SATB2 and Ki-67 in Histological Variants of Unicystic Ameloblastoma.

To characterize the immunohistochemical expression of MDM2, Bcl-2, SATB2 and Ki-67 in histological variants of unicystic ameloblastoma (UA). Following the ethical approval, forty (40) patients with unicystic ameloblastoma were retrieved from the archives and subjected to immunohistochemistry (IHC). Sociodemographic and clinical data were also retrieved. The results were entered into a Microsoft Excel spreadsheet and analyzed using SPSS software. Human tooth germs, which served as the control, showed moderate expression of Bcl-2 and MDM2 with slight proliferative activity in ameloblasts and moderate expression of SATB2 in ectomesenchyme and odontoblasts. Luminal UA (Type 1) showed low Ki-67 index and negative to mild Bcl-2 and MDM2 expression, whilst Type 1.2 (luminal and intraluminal), Type 1.2.3 (luminal, intraluminal and mural), and Type 1.3 (luminal and mural), including the recurrent cases, showed moderate to intense expression with high mean Ki-67 index. The difference between the study groups was statistically significant (p value < 0.001). No expression of SATB2 was noted in any histological variant of UA. Furthermore, no significant differences were noted in age, gender, site and location between the groups. In contrast to luminal variant of UA, mural±intraluminal variants and recurrent cases demonstrate higher expression of Bcl-2 and MDM2 with higher mean Ki-67 index. It may thus be prudent to provide aggressive treatment for cases, not just with mural follicles but also for the patients with intraluminal plexiform proliferation, to prevent recurrence and improve patient outcomes.

Targeting telomerase with MST-312 leads to downregulation of CCND1, MDM2, MYC, and HSP90AA1 and induce apoptosis in Jurkat cell line.

Acute lymphoblastic leukemia is a challenging disease to treat, especially in older adults who are most commonly diagnosed and have a high risk of relapse, even with current treatment options. MST-312, targets the RNA component of telomerase, inhibiting its activity and leading to growth arrest and telomere shortening in cancer cells. This study aimed to investigate the effects of MST-312 on apoptosis rates and the expression of telomerase target genes, CCND1, MDM2, MYC, and HSP90AA1, in Jurkat cell line. Jurkat cell line was cultured and treated with various concentrations of MST-312(0 µM, 0.5 µM, 1 µM, 2 µM, and 4 µM). The optimal concentration of MST-312 was determined using MTT assay. Flow cytometry was employed to evaluate the apoptosis induced by MST-312 treatment. The expression levels of the target genes were measured using real-time polymerase chain reaction before and after the treatment with MST-312. P-value < 0.05 was considered statistically significant. The percentages of apoptotic cells after 48 h, as determined by flow cytometry analysis, were 30.32%, 52.35%, 57.60%, and 68.82%, respectively, compared to the control group which was 4.6%. The expression levels of all genes, including CCND1, MDM2, MYC, and HSP90AA1, were decreased compared to the control group. The results showed that MST-312 induced dose- and time-dependent apoptosis and downregulated the expression of CCND1, MDM2, MYC, and HSP90AA1in Jurkat cell line.

Key Genes Involved in the Beneficial Mechanism of Hyperbaric Oxygen for Glioblastoma and Predictive Indicators of Hyperbaric Oxygen Prolonging Survival in Glioblastoma Patients.

The prognosis of glioblastoma is poor, and therapy-resistance is largely attributed to intratumor hypoxia. Hyperbaric oxygen (HBO) effectively alleviates hypoxia. However, the sole role of HBO in glioblastoma remains controversial. We previously reported that HBO can promote apoptosis, shorten protrusions, and delay growth of glioblastoma, but the molecular mechanism is unclear. We aimed to test candidate genes in HBO-exposed glioblastoma cells and to analyze their correlation with the survival of glioblastoma patients. Glioblastoma cell lines exposed to repetitive HBO or normobaric air (NBA) were collected for RNA isolation and microarray data analysis. GO analysis, KEGG pathway analysis and survival analysis of the differentially expressed genes (DEGs) were performed. HBO not only inhibited hypoxia-inducing genes including CA9, FGF11, PPFIA4, TCAF2 and SLC2A12, but also regulated vascularization by downregulating the expression of COL1A1, COL8A1, COL12A1, RHOJ and FILIP1L, ultimately attenuated hypoxic microenvironment of glioblastoma. HBO attenuated inflammatory microenvironment by reducing the expression of NLRP2, CARD8, MYD88 and CD180. HBO prevented metastasis by downregulating the expression of NTM, CXCL12, CXCL13, CXCR4, CXCR5, CDC42, IGFBP3, IGFBP5, GPC6, MMP19, ADAMTS1, EFEMP1, PTBP3, NF1 and PDCD1. HBO upregulated the expression of BAK1, PPIF, DDIT3, TP53I11 and FAS, whereas downregulated the expression of MDM4 and SIVA1, thus promoting apoptosis. HBO upregulated the expression of CDC25A, MCM2, PCNA, RFC33, DSCC1 and CDC14A, whereas downregulated the expression of ASNS, CDK6, CDKN1B, PTBP3 and MAD2L1, thus inhibiting cell cycle progression. Among these DEGs, 17 indicator-genes of HBO prolonging survival were detected. HBO is beneficial for glioblastoma. Glioblastoma patients with these predictive indicators may prolong survival with HBO therapy. These potential therapeutic targets especially COL1A1, ADAMTS1 and PTBP3 deserve further validation.

HADHA promotes esophageal cancer progression by activating mTOR signaling and the SP1/MDM2 axis.

Esophageal cancer (EC) is one of the most recalcitrant cancers, with a 5-year survival rate of <30%. The hydroxyacyl-CoA dehydrogenase alpha subunit (HADHA) plays an essential role in long-chain fatty acid metabolism, and dysregulation of HADHA has been demonstrated to be involved in a series of metabolic diseases and cancers. However, its role in cancers remains controversial. HADHA has seldom been investigated in EC, and little is known about how HADHA regulates the malignant progression of EC. In this study, we find that HADHA is significantly upregulated in EC tissues and is correlated with poor survival. HADHA knockdown markedly inhibits EC cell proliferation both in vitro and in vivo. The loss of HADHA also induces EC cell apoptosis, causes cell cycle arrest and inhibits cell migration. Additionally, RNA profiling reveals that mTOR signaling is significantly suppressed after HADHA knockdown. Mechanistically, HADHA interacts with SP1 and induces MDM2 expression. In conclusion, both mTOR signaling and the SP1-MDM2 axis participate in the HADHA-induced malignant behavior of EC cells.

Prognostic Importance of PTEN, p53, and MDM2 Expressions in Endometrioid and Serous-Type Endometrial Carcinomas

Aim: Endometrial carcinomas (ECs) are neoplasms with the highest rate of change in the phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway. In this study, the relationship among PTEN, MDM2, and p53 protein expression in the PI3K/AKT/mTOR pathway with clinicopathological data in endometrioid endometrial carcinomas (EECs) and serous-type endometrial carcinomas (SECs) was evaluated. Material and Method: A hundred and twenty cases of patients who underwent hysterectomy for EC between 2009 and 2021 were included in the study. Thirty cases of SEC and 90 cases of EEC were evaluated. EEC cases consist of grades 1-3 tumors, and each group includes 30 patients. p53 was examined in two groups as normal/wild type and abnormal/mutant type. PTEN and MDM2 were examined in two groups: positive and negative. The relationship among p53, PTEN, and MDM2 immunohistochemical expression status with histological grade, myometrial invasion, cervical invasion, lymphovascular invasion (LVI), metastatic lymph nodes, presence of tumor in peritoneal fluid, tumor stage, and overall and progression-free survival was evaluated. Results: Loss of PTEN was associated with EEC compared to SEC (p

Diagnostic Accuracy of Immunohistochemical Expression of p16, MDM2, and CDK4 in Well-Differentiated and De-Differentiated Liposarcoma in MDM2 Fluorescent in situ Hybridisation Confirmed Cases.

To establish the diagnostic utility of immunohistochemistry markers p16 along with MDM2 and CDK-4 in confirming the diagnosis of well-differentiated and de-differentiated liposarcoma while taking Fluorescent in situ Hybridisation (FISH) as a gold standard. A cross-sectional study. Place and Duration of the Study: Department of Histopathology, Armed Forces Institute of Pathology, Rawalpindi, Pakistan, from 30th January 2022 to 30th June 2023. A standard panel of three immunohistochemistry markers p16, MDM2, and CDK4 were applied to 36 cases of atypical lipomatous tumours, well-differentiated liposarcoma (WDLPS), and de-differentiated liposarcoma (DDLPS), on which the gold standard FISH was already performed. The sample size was calculated with the help of a WHO calculator taking prevalence 1-2% in Pakistani population. Qualitative variables such as gender and site of tumour were presented by calculating frequency and percentages and comparison of Immunohistochemistry results with FISH was done by using a 2x2 table. The sensitivity and specificity of this triple marker panel for detecting WDLPS/DDLPS were 43.47% and 15.38%, respectively. The sensitivity and specificity of CDK4 for detecting WDLPS / DDLPS were 82.6% and 15.4%, those of MDM2 were 73.9% and 61.5 %, and those of p16 were 60.9% and 53.8%, respectively. Among all three markers, CDK4 was the most sensitive and MDM2 was the most specific marker for detecting WDLPS-DDLPS. It also showed that a combination of these three markers improves the diagnostic credibility of the immunohistochemistry in diagnosing DDLPS and WDLPS but FISH is the most reliable and confirmatory method. De-differentiated liposarcoma, Well-differentiated liposarcoma, P16, CDK4, MDM2.

Malignant transformation of craniofacial fibrous dysplasia: A clinicopathological, immunohistochemical and molecular analysis of 15 cases in one single institution

ObjectiveMalignant transformation of craniofacial fibrous dysplasia (FD) is not common and its clinicopathological as well as molecular characteristics remain largely unknown with limited literature reports. Study designPatients diagnosed with FD including McCune-Albright syndrome (MAS), polyostotic fibrous dysplasia (PFD), and monostotic fibrous dysplasia (MFD), accompanied by malignant transformation at our institution over the past 18 years (2005–2023) were retrospectively screened and analyzed to investigate the epidemiology and clinicopathological features of these tumors. ResultsThree hundred and five patients were diagnosed as FD in our hospital from 2005 to 2023, with 176 females (57.7 %) and 129 males (42.3 %). The average age at diagnosis was 28.35 years, ranging from 7 to 70 years. A total number of 15 (4. 9 %) cases of FD with malignant transformation were selected. Among these 15 patients, the age of the initial diagnosis of FD ranged from 6 to 54 years (mean age 28.87 ± 16.77), and the ages when malignant transformation occurred ranged from 18 to 57 years (mean age 38.53 ± 13.05). Among 15 patients, 12 patients were female (80 %) and 3 were male (20 %). Fifteen cases included MSA in 2 patients, PFD in 4 patients, and MFD in 9 patients. Of the anatomical sites in craniofacial bones, the most common site of the lesion was the maxilla, followed by the mandible. Malignant neoplasm arising in FD were osteosarcoma (12/15), chondrosarcoma (1/15) and high-grade sarcoma of uncertain differentiation (2/15). The 3- and 5-year overall survival rate was 33.3 % (5/15) and 20 % (3/15) respectively. In secondary osteosarcoma from FD, MDM2 and CDK4 positivity were 33.3 % and 41.7 % respectively, and only one case was MDM2-amplified and CDK4-amplified. ConclusionMalignant transformation in fibrous dysplasia was an exceedingly rare event and with a female predominance. The overall survival rate was poor. Osteosarcoma was the most common malignant neoplasm arising in FD. MDM2 and CDK4 expression may aid in the diagnosis of secondary osteosarcoma in FD.

Synthetic lethality of combined ULK1 defection and p53 restoration induce pyroptosis by directly upregulating GSDME transcription and cleavage activation through ROS/NLRP3 signaling

BackgroundHigh expression of ubiquitin ligase MDM2 is a primary cause of p53 inactivation in many tumors, making it a promising therapeutic target. However, MDM2 inhibitors have failed in clinical trials due to p53-induced feedback that enhances MDM2 expression. This underscores the urgent need to find an effective adaptive genotype or combination of targets.MethodsKinome-wide CRISPR/Cas9 knockout screen was performed to identify genes that modulate the response to MDM2 inhibitor using TP53 wild type cancer cells and found ULK1 as a candidate. The MTT cell viability assay, flow cytometry and LDH assay were conducted to evaluate the activation of pyroptosis and the synthetic lethality effects of combining ULK1 depletion with p53 activation. Dual-luciferase reporter assay and ChIP-qPCR were performed to confirm that p53 directly mediates the transcription of GSDME and to identify the binding region of p53 in the promoter of GSDME. ULK1 knockout / overexpression cells were constructed to investigate the functional role of ULK1 both in vitro and in vivo. The mechanism of ULK1 depletion to activate GSMDE was mainly investigated by qPCR, western blot and ELISA.ResultsBy using high-throughput screening, we identified ULK1 as a synthetic lethal gene for the MDM2 inhibitor APG115. It was determined that deletion of ULK1 significantly increased the sensitivity, with cells undergoing typical pyroptosis. Mechanistically, p53 promote pyroptosis initiation by directly mediating GSDME transcription that induce basal-level pyroptosis. Moreover, ULK1 depletion reduces mitophagy, resulting in the accumulation of damaged mitochondria and subsequent increasing of reactive oxygen species (ROS). This in turn cleaves and activates GSDME via the NLRP3-Caspase inflammatory signaling axis. The molecular cascade makes ULK1 act as a crucial regulator of pyroptosis initiation mediated by p53 activation cells. Besides, mitophagy is enhanced in platinum-resistant tumors, and ULK1 depletion/p53 activation has a synergistic lethal effect on these tumors, inducing pyroptosis through GSDME directly.ConclusionOur research demonstrates that ULK1 deficiency can synergize with MDM2 inhibitors to induce pyroptosis. p53 plays a direct role in activating GSDME transcription, while ULK1 deficiency triggers upregulation of the ROS-NLRP3 signaling pathway, leading to GSDME cleavage and activation. These findings underscore the pivotal role of p53 in determining pyroptosis and provide new avenues for the clinical application of p53 restoration therapies, as well as suggesting potential combination strategies.

CEP-1347 Boosts Chk2-Mediated p53 Activation by Ionizing Radiation to Inhibit the Growth of Malignant Brain Tumor Cells.

Radiation therapy continues to be the cornerstone treatment for malignant brain tumors, the majority of which express wild-type p53. Therefore, the identification of drugs that promote the ionizing radiation (IR)-induced activation of p53 is expected to increase the efficacy of radiation therapy for these tumors. The growth inhibitory effects of CEP-1347, a known inhibitor of MDM4 expression, on malignant brain tumor cell lines expressing wild-type p53 were examined, alone or in combination with IR, by dye exclusion and/or colony formation assays. The effects of CEP-1347 on the p53 pathway, alone or in combination with IR, were examined by RT-PCR and Western blot analyses. The combination of CEP-1347 and IR activated p53 in malignant brain tumor cells and inhibited their growth more effectively than either alone. Mechanistically, CEP-1347 and IR each reduced MDM4 expression, while their combination did not result in further decreases. CEP-1347 promoted IR-induced Chk2 phosphorylation and increased p53 expression in concert with IR in a Chk2-dependent manner. The present results show, for the first time, that CEP-1347 is capable of promoting Chk2-mediated p53 activation by IR in addition to inhibiting the expression of MDM4 and, thus, CEP-1347 has potential as a radiosensitizer for malignant brain tumors expressing wild-type p53.

Melatonin effect on breast and ovarian cancers by targeting the PI3K/Akt/mTOR pathway.

Melatonin, the hormone of the pineal gland, possesses a range of physiological functions, and recently, its anticancer effect has become more apparent. A more thorough understanding of molecular alterations in the components of several signaling pathways as new targets for cancer therapy is needed because of current innate restrictions such as drug toxicity, side effects, and acquired or de novo resistance. The PI3K/Akt/mTOR pathway is overactivated in many solid tumors, such as breast and ovarian cancers. This pathway in normal cells is essential for growth, proliferation, and survival. However, it is an undesirable characteristic in malignant cells. We have reviewed multiple studies about the effect of melatonin on breast and ovarian cancer, focusing on the PI3K/Akt/mTOR pathway. Melatonin exerts its inhibitory effects via several mechanisms. A: Downregulation of downstream or upstream components of the signaling pathway such as phosphatase and tensin homolog (PTEN), phosphatidylinositol (3,4,5)-trisphosphate kinase (PI3K), p-PI3K, Akt, p-Akt, mammalian target of rapamycin (mTOR), and mTOR complex1 (mTORC1). B: Apoptosis induction by decreasing MDM2 expression, a downstream target of Akt, and mTOR, which leads to Bad activation in addition to Bcl-XL and p53 inhibition. C: Induction of autophagy in cancer cells via activating ULK1 after mTOR inhibition, resulting in Beclin-1 phosphorylation. Beclin-1 with AMBRA1 and VPS34 promotes PI3K complex I activity and autophagy in cancer cells. The PI3K/Akt/mTOR pathway overlaps with other intracellular signaling pathways and components such as AMP-activated protein kinase (AMPK), Wnt/β-catenin, mitogen-activated protein kinase (MAPK), and other similar pathways. Cancer therapy can benefit from understanding how these pathways interact and how melatonin affects these pathways.

Effects of tauroursodeoxycholate on arsenic-induced hepatic injury in mice: A comparative transcriptomic analysis

BackgroundProlonged exposure to excessive arsenic (As) and its compounds can cause damage to multiple systems, including respiratory, cardiovascular, immune, nervous, and endocrine systems. Manifestations include changes in skin pigmentation, excessive keratosis on palms and soles, gastrointestinal symptoms, and anemia. The liver as an important detoxification organ of the body, is a significant target organ for arsenic toxicity, and liver diseases are common. So far, the molecular mechanism has not been fully elucidated. Evidence suggests that taurodeoxycholic acid (TUDCA) has a protective role in arsenic-induced liver injury. This study aims to reveal potential target genes at the transcriptional level following TUDCA intervention, providing insights for the intervention of arsenic-induced liver injury. MethodsThe TUDCA intervention model of arsenic liver injury in C57BL/6 N mice was established. The experiment was divided into two phases and lasted for 24 weeks. The phase I trial (12 weeks) was divided into control, low, middle and high groups according to the dose of As. The phaseⅡtrial (12 weeks) was administered in combination with 10 mg/L sodium arsenite (the first stage high arsenic group) and TUDCA, so subsequent groups was named with H indicating high arsenic. Divide into four groups: control group(C), TUDCA solvent control group(H-Vehicle), TUDCA combined with As group(H-TUDCA), arsenic group (As). As was ingested through free water and TUDCA was administered to mice by gavage at a dose of 0.1 mL/10 g.b.w (100 mg/kg) once a day for 12 weeks. The differential expression gene (DEG) profile was obtained from the second batch of mouse liver tissues by RNA sequencing technology. Comparative transcriptomic analysis methods were used to identify co-varying DEGs between arsenic induction and TUDCA intervention, along with their associated pathways. QRT-PCR was utilized for validation. ResultsTranscriptome results showed that 487 DEGs were identified after arsenic induction. TUDCA intervention identified 231 DEGs (p-values < 0.05 and | log2(fold change) | > 1). The comparison of "AS vs C" and "H_TUDCA vs AS" identified 65 covariant DEGs, and further screened the TUDCA pathways and related genes among these genes，six pathways and 11 genes (Ccl21a, Ccr7, Mdm2, Slc2a4, Akr1b7, Pnpla3, Dusp8, Hspa1a, Cyp7a1, Cybrd1, Trpm6) were obtained. Next, we screened for covariant DEGs among the top 50 potential hub genes in arsenic-induced DEGS, and obtained 7 (Hbb-bs, Hspa1a, Mdm2, Slc2a4, Ptk6, Egr1, and Dusp8). Finally, the intersection of Hub gene and pathway gene was selected as the target genes Dusp8, Hspa1a, Mdm2 and Slc2a4. The sequencing results showed that the mRNA expressions of Dusp8, Hspa1a and Mdm2 were significantly increased after arsenic induction, while the expression of Slc2a4 was significantly decreased (P<0.05). Conversely, TUDCA intervention reversed these DEGs changes, consistent with QRT-PCR validation results. ConclusionThis study contributes to understanding the potential health effects of arsenic-induced liver injury, identifying new potential targets, and providing references for TUDCA intervention.

MDM2 Is Essential to Maintain the Homeostasis of Epithelial Cells by Targeting p53.

MDM2 is known as the primary negative regulator of p53, and MDM2 promotes lung cancer fibrosis and lung injury through p53-dependent and p53-independent pathways. However, the mechanism by which MDM2 influences the pathogenesis of asthma is unknown. In this study, we investigated the function of MDM2 in lung epithelial cells in type 2 lung inflammation. We used type II alveolar epithelial cell-specific heterozygous knockout of Mdm2 mice to validate its function. Then papain-induced asthma model was established, and changes in inflammation were observed by measuring immunohistochemistry and flow cytometry analysis. In this study, we knockdown the mouse Mdm2 gene in type 2 alveolar epithelial cells. We demonstrated that heterozygous Mdm2 gene-deleted mice were highly susceptible to protease allergen papain-induced pulmonary inflammation characterized by increased ILC2 numbers, IL-5 and IL-13 cytokine levels, and lung pathology. A mechanistic study showed that following the decreased expression of Mdm2 in lung epithelial cells and A549 cell line, p53 was overactivated, and the expression of its downstream genes p21, Puma, and Noxa was elevated, which resulted in apoptosis. After Mdm2 knockdown, the mRNA expression of inflammation-related gene IL-25, HMGB1, and TNF-α were increased, which further amplified the downstream ILC2 response and lung inflammation. These results indicate that Mdm2 maintains the homeostasis of lung epithelial cells by targeting P53 and regulates the function of lung epithelial cells under type 2 lung inflammation.

The role of MDM2 in angiogenesis: implications for endothelial tip cell formation.

In the present study, we examined the role of MDM2 in the angiogenesis process and its potential association with the sprouting of endothelial tip cells. To address this, we performed hypoxia-treated gastric cancer cells (HGC-27) to quantitative RT-PCR and Western blot analysis to measure the levels of MDM2 and VEGF-A mRNA and protein expression. Subsequently, we employed siRNA to disrupt MDM2 expression, followed by hypoxia treatment. The expression levels of MDM2 and VEGF-A mRNA and protein were subsequently reassessed. Additionally, ELISA was utilized to quantify the secretion levels of VEGF-A in each experimental group. A conditioned medium derived from HGC-27 cells treated with different agents was employed to assess its influence on the formation of EA.hy926 endothelial tip cells, using various techniques including Transwell plates migration assays, wound healing experiments, vascular formation assays, scanning electron microscopy, and immunofluorescence staining. These findings demonstrated that the in vitro knockdown of MDM2 in the conditioned medium exhibited significant inhibitory effects on endothelial cell migration, wound healing, and vascular formation. Additionally, the intervention led to a reduction in the presence of CD34+ tip cells and the formation of filopodia in endothelial cells, while partially restoring the integrity of tight junctions. Subsequent examination utilizing RNA-seq revealed that the suppression of MDM2 in HGC-27 cells resulted in the downregulation of the PI3K/AKT signaling pathway. Consequently, this downregulation led to an elevation in angiogenic effects induced by hypoxia.

Genes Co-Expressed with ESR2 Influence Clinical Outcomes in Cancer Patients: TCGA Data Analysis.

ERβ has been assigned a tumor suppressor role in many cancer types. However, as conflicting findings emerge, ERβ's tissue-specific expression and functional role have remained elusive. There remains a notable gap in compact and comprehensive analyses of ESR2 mRNA expression levels across diverse tumor types coupled with an exploration of its potential gene network. In this study, we aim to address these gaps by presenting a comprehensive analysis of ESR2 transcriptomic data. We distinguished cancer types with significant changes in ESR2 expression levels compared to corresponding healthy tissue and concluded that ESR2 influences patient survival. Gene Set Enrichment Analysis (GSEA) distinguished molecular pathways affected by ESR2, including oxidative phosphorylation and epithelial-mesenchymal transition. Finally, we investigated genes displaying similar expression patterns as ESR2 in tumor tissues, identifying potential co-expressed genes that may exert a synergistic effect on clinical outcomes, with significant results, including the expression of ACIN1, SYNE2, TNFRSF13C, and MDM4. Collectively, our results highlight the significant influence of ESR2 mRNA expression on the transcriptomic landscape and the overall metabolism of cancerous cells across various tumor types.

Expression and Function of FAM72A Gene in Multiple myelomaFAM72A.

This study aims to comprehensively investigate the role of Family Member A with sequence similarity 72-A (FAM72A) in multiple myeloma. Multiple myeloma poses significant challenges. This study delves into FAM72A's impact on key cellular processes, shedding light on potential therapeutic targets and enhancing our understanding of multiple myeloma progression. Investigate the impact of FAM72A on the proliferation, apoptosis, and bortezomib sensitivity of multiple myeloma cell line U266. qRT-PCR analyzed FAM72A expression levels in bone marrow samples from 30 patients with multiple myeloma and 10 healthy donors at the Second Hospital of Shanxi Medical University. Cell lines overexpressing FAM72A were constructed, and Cell Counting Kit 8 (CCK-8) and flow cytometry were used to assess U266 cell proliferation, apoptosis, and sensitivity to bortezomib. Biological predictions for FAM72A were performed to find transcription factors binding to the FAM72A promoter region, verified using a luciferase assay. U266 cells were transfected with si-POU2F2 (POU class 2 homeobox 2), and the impact on cell proliferation was validated. Western blot analysis detected the expression of downstream proteins in the p53 signaling pathway. In vivo, experiments established a xenograft mouse model further to study the role of FAM72A in multiple myeloma. FAM72A was upregulated in multiple myeloma bone marrow tissues. Compared to the OE-NC group, the OE-FAM72A group showed increased Mouse Double Minute 2 homolog (MDM2) expression, decreased p53 expression, increased cell proliferation, and decreased apoptosis. POU2F2 was identified as the upstream transcription factor for FAM72A. Compared to the si-NC group, the si-POU2F2 group exhibited decreased MDM2 expression, increased p53 expression, slowed cell proliferation, and increased apoptosis. Silencing POU2F2 could reverse the pro-proliferative effect of over-expressing FAM72A in U266 cells. In vivo experiments in a xenograft mouse model further studied the role of FAM72A in multiple myeloma. Overexpression of FAM72A promotes U266 cell proliferation, inhibits apoptosis, and reduces sensitivity to bortezomib by regulating the POU2F2/FAM72A/p53 signaling pathway.

A testis-specific lncRNA functions as a post-transcriptional regulator of MDM2 and stimulates apoptosis of testicular germ cell tumor cells

Germ cells preferentially induce apoptosis in response to DNA damage to avoid genomic mutations. Apoptosis of germ cells is closely related to cancer development and chemotherapy resistance; however, its regulatory mechanism is unclear. Here, we suggest that testis-specific lncRNA LINC03074 is involved in male germ cell apoptosis by regulating the expression of the proto-oncogene MDM2. LINC03074 is highly expressed in the sperm of healthy adult testes and cancer cells of testes with testicular germ cell tumors (TGCTs). LINC03074 binds to MDM2 mRNA via an Alu element, thereby reducing MDM2 protein levels. LINC03074 stimulates STAU1-mediated nuclear export of MDM2 mRNA by increasing STAU1 binding to MDM2 mRNA in the cell nucleus, thereby promoting PKR-mediated translational repression in the cytoplasm. The induction of apoptosis in TGCT cells and their responsiveness to the anticancer drug cisplatin is enhanced by LINC03074. Notably, LINC03074 increased E2F1 expression without increasing p53, the primary target of MDM2, and upregulated the apoptotic gene p73, the target gene of E2F1. LINC03074-mediated regulation of apoptosis contributes to the responsiveness of TGCTs to anticancer drug-induced DNA damage.

MDM2 inhibitor APG-115 synergizes with ABT-199 to induce cell apoptosis in chronic lymphocytic leukemia.

Although clinical outcomes in chronic lymphocytic leukemia (CLL) have greatly improved with several approved small molecular inhibitors, acquired resistance does occur, leading to disease progression and eventual death. Thus, the effort to explore novel inhibitors and combination therapeutic regimens is needed. The inhibition of MDM2-p53 interaction to restore p53 function has been regarded as a potential strategy for treating different cancers. We investigated the effects of novel MDM2 inhibitor APG-115 in CLL. We found that APG-115 treatment upregulated the expression of p53, MDM2, and p21 at the mRNA and protein level. APG-115 inhibited cell proliferation, induced apoptosis, and arrested the cell cycle at G0/G1 stage. Moreover, APG-115 inhibited the expression of BCL-2, BCL-xL, and MCL-1, and suppressed the activation of AKT and ERK signaling pathways. APG-115 combined with the BCL2 inhibitor, ABT-199 (venetoclax), led to further inhibition of the expression of BCL-2 family anti-apoptotic proteins and consequently enhanced cell death. Collectively, this study demonstrates that APG-115 activates p53 and thus inhibits multiple pro-survival mechanisms, which provides a rational explanation for APG-115 efficiency in inducing cell apoptosis in CLL. The synergistic effect of APG-115 with ABT-199 suggested a potential combination application in CLL therapy.

Functional evaluation of germline TP53 variants identified in Brazilian families at-risk for Li–Fraumeni syndrome

Germline TP53 pathogenic variants can lead to a cancer susceptibility syndrome known as Li–Fraumeni (LFS). Variants affecting its activity can drive tumorigenesis altering p53 pathways and their identification is crucial for assessing individual risk. This study explored the functional impact of TP53 missense variants on its transcription factor activity. We selected seven TP53 missense variants (c.129G > C, c.320A > G, c.417G > T, c.460G > A, c,522G > T, c.589G > A and c.997C > T) identified in Brazilian families at-risk for LFS. Variants were created through site-directed mutagenesis and transfected into SK-OV-3 cells to assess their transcription activation capabilities. Variants K139N and V197M displayed significantly reduced transactivation activity in a TP53-dependent luciferase reporter assay. Additionally, K139N negatively impacted CDKN1A and MDM2 expression and had a limited effect on GADD45A and PMAIP1 upon irradiation-induced DNA damage. Variant V197M demonstrated functional impact in all target genes evaluated and loss of Ser15 phosphorylation. K139N and V197M variants presented a reduction of p21 levels after irradiation. Our data show that K139N and V197M negatively impact p53 functions, supporting their classification as pathogenic variants. This underscores the significance of conducting functional studies on germline TP53 missense variants classified as variants of uncertain significance to ensure proper management of LFS-related cancer risks.

Association analysis of indel variants and gene expression identifies MDM4 as a novel locus for skeletal muscle hypertrophy and power athlete status.

Insertions and deletions (indels) are the second most common type of variation in the human genome. However, limited data on their associations with exercise-related phenotypes have been documented. The aim of the present study was to examine the association between 18,370 indel variants and power athlete status, followed by additional studies in 357,246 individuals. In the discovery phase, the D allele of the MDM4 gene rs35493922 I/D polymorphism was over-represented in power athletes compared with control subjects (P=7.8×10-9) and endurance athletes (P=0.0012). These findings were replicated in independent cohorts, showing a higher D allele frequency in power athletes compared with control subjects (P=0.016) and endurance athletes (P=0.031). Furthermore, the D allele was positively associated (P=0.0013) with greater fat-free mass in the UK Biobank. MDM4 encodes a protein that inhibits the activity of p53, which induces muscle fibre atrophy. Accordingly, we found that MDM4 expression was significantly higher in the vastus lateralis of power athletes compared with endurance athletes (P=0.0009) and was positively correlated with the percentage of fast-twitch muscle fibres (P=0.0062) and the relative area occupied by fast-twitch muscle fibres (P=0.0086). The association between MDM4 gene expression and an increased proportion of fast-twitch muscle fibres was confirmed in two additional cohorts. Finally, we found that the MDM4 DD genotype was associated with increased MDM4 gene expression in vastus lateralis and greater cross-sectional area of fast-twitch muscle fibres. In conclusion, MDM4 is suggested to be a potential regulator of muscle fibre specification and size, with its indel variant being associated with power athlete status. HIGHLIGHTS: What is the central question of this study? Which indel variants are functional and associated with sport- and exercise-related traits? What is the main finding and its importance? Out of 18,370 tested indels, the MDM4 gene rs35493922 I/D polymorphism was found to be the functional variant (affecting gene expression) and the most significant, with the deletion allele showing associations with power athlete status, fat-free mass and cross-sectional area of fast-twitch muscle fibres. Furthermore, the expression of MDM4 was positively correlated with the percentage of fast-twitch muscle fibres and the relative area occupied by fast-twitch muscle fibres.