Prognostic Factors for Long-Term Eribulin Response in a Cohort of Patients With HER2-Negative Metastatic Breast Cancer.

CONTEXT AND AIMS: Eribulin is used in taxane and anthracycline refractory HER2-negative metastatic breast cancers (MBC). Patients treated in pivotal clinical trials achieved low survival rates, therefore, the identification of prognostic criteria for long progression-free survival (PFS) is still an unmet medical need. In this study, we sought to determine potential prognostic criteria for long-term eribulin response in HER2-negative MBC. METHODS: Our retrospective cohort includes female patients with HER2-negative MBC treated with eribulin in Franche-Comté, France. We defined a long-term response as at least 6 months of eribulin treatment. The primary endpoint was the analysis of criteria that differ according to the progression-free survival. Secondary outcomes concerned overall survival and response rate. RESULTS: From January 2011 to April 2020, 431 patients treated with eribulin were screened. Of them, 374 patients were included. Median PFS was 3.2 months (2.8-3.7). Eighty-eight patients (23.5%) had a long-term response to eribulin. Four discriminant criteria allowed to separate PFS in 2 arms (PFS < 3 months or > 6 months) with a 78% positive predictive value: histological grade, absence of meningeal metastasis, response to prior chemotherapy, and OMS status. We have developed a nomogram combining these 4 criteria. Median overall survival was 8.5 months (7.0-9.5). CONCLUSION: Eribulin response in MBC can be driven by clinical and biological factors. Application of our nomogram could assist in the prescription of eribulin.

ESF1 positively regulates MDM2 and promotes tumorigenesis.

Eighteen S rRNA factor 1 (ESF1) is a predominantly nucleolar protein essential for embryogenesis. Our previous studies have suggested that Esf1 is a negative regulator of the tumor suppressor protein p53. However, it remains unclear whether ESF1 contributes to tumorigenesis. In this current research, we find that increased ESF1 expression correlates with poor survival in multiple tumors including pancreatic cancer. ESF1 is able to regulate cell proliferation, migration, DNA damage-induced apoptosis, and tumorigenesis. Mechanistically, ESF1 physically interacts with MDM2 and is essential for maintaining the stability of MDM2 protein by inhibiting its ubiquitination. Additionally, ESF1 also prevented stress-induced stabilization of p53 in multiple cancer cells. Hence, our findings suggest that ESF1 is a potent regulator of the MDM2-p53 pathway and promotes tumor progression.

Sanggenol L induces ferroptosis in non-small cell lung cancer cells via regulating the miR-26a-1-3p/MDM2/p53 signaling pathway.

Ferroptosis is a regulated cell death marked by iron-dependent lipid peroxidation. Tumor cells that survive by evading chemotherapy-induced apoptosis are vulnerable to ferroptosis. Therefore, it is particularly urgent to explore active ingredients that can selectively induce ferroptosis in cancer cells. Here, we revealed that sanggenol L, the active agent of Morus Bark, predisposed non-small cell lung cancer (NSCLC) cells to ferroptosis, evidenced by reactive oxygen species (ROS) accumulation, glutathione depletion, mitochondrial shrinkage, and lipid peroxidation. Furthermore, the ferroptosis-related miRNA array showed that sanggenol L treatment upregulated the level of miR-26a-1-3p, which directly targeted the E3 ubiquitin ligase MDM2. In addition, silencing MDM2 by miR-26a-1-3p resulted in a notable increase in p53 protein levels and decrease of its downstream target SLC7A11, ultimately triggered ferroptosis. The subcutaneous xenograft model and patient-derived tumor xenograft (PDX) model of NSCLC further confirmed the anti-tumor efficacy and safety of sanggenol L in vivo. Collectively, our data suggest that miR-26a-1-3p/MDM2/p53/SLC7A11 signaling axis plays a key role in sanggenol L-induced ferroptosis, which implies that sanggenol L can serves as an anticancer therapeutic arsenal for NSCLC.

ZBTB7A interferes with the RPL5-P53 feedback loop and reduces endoplasmic reticulum stress-induced apoptosis of pancreatic cancer cells.

Endoplasmic reticulum (ER) stress is a primary mechanism leading to cell apoptosis, making it of great research interests in cancer management. This study delves into the function of ribosomal protein L5 (RPL5) in ER stress within pancreatic cancer (PCa) cells and investigates its regulatory mechanisms. Bioinformatics predictions pinpointed RPL5 as an ER stress-related gene exhibiting diminished expression in PCa. Indeed, RPL5 was found to be poorly expressed in PCa tissues and cells, with this reduced expression correlating with an unfavorable prognosis. Moreover, RPL5 overexpression led to heightened levels of p-PERK, p-eIF2α, and CHOP, bolstering the proapoptotic effect of Tunicamycin, an ER stress activator, on PCa cells. Additionally, the RPL5 overexpression curbed cell proliferation, migration, and invasion. Tunicamycin enhanced the binding between RPL5 and murine double minute 2 (MDM2), thus suppressing MDM2-mediated ubiquitination and degradation of P53. Consequently, P53 augmentation intensified ER stress, which further enhanced the binding between RPL5 and MDM2 through PERK-dependent eIF2α phosphorylation, thereby establishing a positive feedback loop. Zinc finger and BTB domain containing 7A (ZBTB7A), conspicuously overexpressed in PCa samples, repressed RPL5 transcription, thereby reducing P53 expression. Silencing of ZBTB7A heightened ER stress and subdued the malignant attributes of PCa cells, effects counteracted upon RPL5 silencing. Analogous outcomes were recapitulated in vivo employing a xenograft tumor mouse model, where ZBTB7A silencing dampened the tumorigenic potential of PCa cells, an effect reversed by additional RPL5 silencing. In conclusion, this study suggests that ZBTB7A represses RPL5 transcription, thus impeding the RPL5-P53 feedback loop and mitigating ER-induced apoptosis in PCa cells.

Working title: Molecular involvement of p53-MDM2 interactome in gastrointestinal cancers.

The interaction between murine double minute 2 (MDM2) and p53, marked by transcriptional induction and feedback inhibition, orchestrates a functional loop dictating cellular fate. The functional loop comprising p53-MDM2 axis is made up of an interactome consisting of approximately 81 proteins, which are spatio-temporally regulated and involved in DNA repair mechanisms. Biochemical and genetic alterations of the interactome result in dysregulation of the p53-mdm2 axis that leads to gastrointestinal (GI) cancers. A large subset of interactome is well known and it consists of proteins that either stabilize p53 or MDM2 and proteins that target the p53-MDM2 complex for ubiquitin-mediated destruction. Upstream signaling events brought about by growth factors and chemical messengers invoke a wide variety of posttranslational modifications in p53-MDM2 axis. Biochemical changes in the transactivation domain of p53 impact the energy landscape, induce conformational switching, alter interaction potential and could change solubility of p53 to redefine its co-localization, translocation and activity. A diverse set of chemical compounds mimic physiological effectors and simulate biochemical modifications of the p53-MDM2 interactome. p53-MDM2 interactome plays a crucial role in DNA damage and repair process. Genetic aberrations in the interactome, have resulted in cancers of GI tract (pancreas, liver, colorectal, gastric, biliary, and esophageal). We present in this article a review of the overall changes in the p53-MDM2 interactors and the effectors that form an epicenter for the development of next-generation molecules for understanding and targeting GI cancers.

Study on the design, synthesis, and activity of anti-tumor staple peptides targeting MDM2/MDMX.

Staple peptides, which have a significantly enhanced pharmacological profile, are promising therapeutic molecules due to their remarkable resistance to proteolysis and cell-penetrating properties. In this study, we designed and synthesized a series of PMI-M3-based dual-targeting MDM2/MDMX staple peptides and compared them with straight-chain peptides. The staple peptide SM3-4 screened in the study induced apoptosis of tumor cells in vitro at low µM concentrations, and the helix was significantly increased. Studies have shown that the enhancement of staple activity is related to the increase in helicity, and SM3-4 provides an effective research basis for dual-targeted anti-tumor staple peptides.

Cordycepin Ameliorates Psoriasis-Like Skin Lesion by Regulating p53/MDM2 Feedback Loop.

Apoptosis is a natural physiological process of programmed cell death. It is essential for maintaining the homeostasis of the body and the immune system. The dysfunction of apoptosis can lead to the development of autoimmune diseases. In psoriasis, the dysfunction of keratinocyte proliferation manifests as an impairment of apoptosis. Cordycepin is the major active component in cordyceps militaris and has pharmacological effects, including regulation of apoptosis. The pharmacological mechanism of Cordycepin in psoriasis remains unclear. In this study, bioinformatics analysis revealed that the mechanism may be associated with the p53 apoptotic pathway. Further, we confirmed in the experiments that cordycepin inhibited the interleukin (IL)-17A-induced proliferation of HaCaT cells and down-regulated the expression of proliferating cell nuclear antigen (PCNA) and Ki-67. Regulating the expression of apoptotic proteins BAX, Bcl-2, and p53 promote apoptosis. Further investigation of the upstream pathway of apoptosis revealed that cordycepin could normalize the abnormal p53-mouse double minute 2 (MDM2) feedback loop. In vivo results showed that the cordycepin gel could effectively improve imiquimod (IMQ)-induced psoriasis-like skin lesions in mice, and the p53-MDM2 pathway was verified at the protein level. In conclusion, the anti-psoriasis effect of Cordycepin and its potential mechanism have not been discussed in detail. However, our work supports the idea that Cordycepin can be further developed as an Active Pharmaceutical Ingredient (API) for the treatment of psoriasis.

Recent Advances on Mutant p53: Unveiling Novel Oncogenic Roles, Degradation Pathways, and Therapeutic Interventions.

The p53 protein is the master regulator of cellular integrity, primarily due to its tumor-suppressing functions. Approximately half of all human cancers carry mutations in the TP53 gene, which not only abrogate the tumor-suppressive functions but also confer p53 mutant proteins with oncogenic potential. The latter is achieved through so-called gain-of-function (GOF) mutations that promote cancer progression, metastasis, and therapy resistance by deregulating transcriptional networks, signaling pathways, metabolism, immune surveillance, and cellular compositions of the microenvironment. Despite recent progress in understanding the complexity of mutp53 in neoplastic development, the exact mechanisms of how mutp53 contributes to cancer development and how they escape proteasomal and lysosomal degradation remain only partially understood. In this review, we address recent findings in the field of oncogenic functions of mutp53 specifically regarding, but not limited to, its implications in metabolic pathways, the secretome of cancer cells, the cancer microenvironment, and the regulating scenarios of the aberrant proteasomal degradation. By analyzing proteasomal and lysosomal protein degradation, as well as its connection with autophagy, we propose new therapeutical approaches that aim to destabilize mutp53 proteins and deactivate its oncogenic functions, thereby providing a fundamental basis for further investigation and rational treatment approaches for TP53-mutated cancers.

Reciprocal regulation between RACGAP1 and AR contributes to endocrine therapy resistance in prostate cancer.

BACKGROUND: Endocrine resistance driven by sustained activation of androgen receptor (AR) signaling pathway in advanced prostate cancer (PCa) is fatal. Characterization of mechanisms underlying aberrant AR pathway activation to search for potential therapeutic strategy is particularly important. Rac GTPase-activating protein 1 (RACGAP1) is one of the specific GTPase-activating proteins. As a novel tumor proto-oncogene, overexpression of RACGAP1 was related to the occurrence of various tumors. METHODS: Bioinformatics methods were used to analyze the relationship of expression level between RACGAP1 and AR as well as AR pathway activation. qRT-PCR and western blotting assays were performed to assess the expression of AR/AR-V7 and RACGAP1 in PCa cells. Immunoprecipitation and immunofluorescence experiments were conducted to detect the interaction and co-localization between RACGAP1 and AR/AR-V7. Gain- and loss-of-function analyses were conducted to investigate the biological roles of RACGAP1 in PCa cells, using MTS and colony formation assays. In vivo experiments were conducted to evaluate the effect of RACGAP1 inhibition on the tumor growth. RESULTS: RACGAP1 was a gene activated by AR, which was markedly upregulated in PCa patients with CRPC and enzalutamide resistance. AR transcriptionally activated RACGAP1 expression by binding to its promoter region. Reciprocally, nuclear RACGAP1 bound to the N-terminal domain (NTD) of both AR and AR-V7, blocking their interaction with the E3 ubiquitin ligase MDM2. Consequently, this prevented the degradation of AR/AR-V7 in a ubiquitin-proteasome-dependent pathway. Notably, the positive feedback loop between RACGAP1 and AR/AR-V7 contributed to endocrine therapy resistance of CRPC. Combination of enzalutamide and in vivo cholesterol-conjugated RIG-I siRNA drugs targeting RACGAP1 induced potent inhibition of xenograft tumor growth of PCa. CONCLUSION: In summary, our results reveal that reciprocal regulation between RACGAP1 and AR/AR-V7 contributes to the endocrine resistance in PCa. These findings highlight the therapeutic potential of combined RACGAP1 inhibition and enzalutamide in treatment of advanced PCa.

Cancer-associated MDM2 W329G mutant attenuates ribosomal stress-mediated p53 responses to promote cell survival and glycolysis.

Although amplification/overexpression is the predominant mechanism for the oncogenic properties of MDM2, an increasing number of MDM2 somatic missense mutations were identified in cancer patients with the recent advances in sequencing technology. Here, we characterized an MDM2 cancer-associated mutant variant W329G identified from a patient sample that contains a wild-type p53 gene. Trp329 is one of residues that were reported to be critical to MDM2's binding to ribosomal protein L11 (RPL11). We found that the MDM2 W329G mutant was resistant to the inhibitory effect of RPL11 on MDM2-mediated p53 ubiquitination and degradation, in line with its defect on RPL11 binding. Using isogenic U2OS cells with or without endogenous MDM2 W329G mutation, we demonstrated that the expression of classic p53 targets induced by ribosomal stress signals was reduced in mutant cells. RNA-seq analysis revealed that upon 5-FU treatment, the p53 response was significantly impaired. Also, the 5-FU-mediated repression of genes in cell cycle progression and DNA replication was diminished in W329G mutant-containing cells. Physiologically, U2OS W329G cells were more resistant to cell growth inhibition induced by ribosomal stress and exhibited higher glycolytic rates upon 5-FU treatment. Together, our data indicated that cancer-associated MDM2 W329G mutant attenuates ribosomal stress-mediated p53 responses to promote cell survival and glycolysis.

Treatment options for biliary tract cancer: unmet needs, new targets and opportunities from both physicians' and patients' perspectives.

Biliary tract cancer (BTC) is a rare cancer with poor prognosis, characterized by considerable pathophysiological and molecular heterogeneity. While this makes it difficult to treat, it also provides targeted therapy opportunities. Current standard-of-care is chemotherapy ± immunotherapy, but several targeted agents have recently been approved. The current investigational landscape in BTC emphasizes the importance of biomarker testing at diagnosis. MDM2/MDMX are important negative regulators of the tumor suppressor p53 and provide an additional target in BTC (∼5-8% of tumors are MDM2-amplified). Brigimadlin (BI 907828) is a highly potent MDM2-p53 antagonist that has shown antitumor activity in preclinical studies and promising results in early clinical trials; enrollment is ongoing in a potential registrational trial for patients with BTC.

[Box: see text].

Transoral Excision of a Hypopharyngeal Liposarcoma.

Liposarcomas are the most common soft tissue sarcoma in adults, whereas liposarcomas of the head and neck, particularly the hypopharynx, are incredibly rare - with approximately 50 cases reported in the literature. We present a case of an otherwise healthy and asymptomatic 42-year-old male who presented dramatically after vomiting up a large soft tissue mass. The lesion was surgically removed via transoral approach with blue laser, and diagnosis of well-differentiated liposarcoma was made via MDM2 gene amplification by FISH. Oral extrusion is a rare feature of this disease. This is the first documented case of an orally extruded liposarcoma to present in an otherwise asymptomatic and healthy patient, demonstrating how this entity may be indolent until initial presentation. Laryngoscope, 2024.

Cytotoxic Effect of YH239-EE and Its Enantiomer on MCF7 Cell Line.

OBJECTIVE: This study aimed to discover the cytotoxic effect of YH239-EE and YH239 alone and their enantiomer potency in cytotoxic effect on the MCF7 cell line. METHODS: We used the cytotoxic study on MDM2 cell lines by detecting the percentage of apoptosis and necrosis by annexin v methods. RESULT: This result shows that YH239-EE causes more apoptosis and necrosis 40% in comparison to YH239 without ethyl ester, about 4.92 %,  and The (+) enantiomer of YH239-EE demonstrated a markedly higher induction of apoptosis and necrosis (84.48%) in MCF7 cells compared to the (-) enantiomer (48.71%). CONCLUSION: The ethyl ester group in YH239-EE might play a crucial role in enhancing the compound's ability to induce cell death, and The high efficacy of the (+) enantiomer of YH239-EE in inducing cell death in MCF7 cells suggests it may be a more promising therapeutic candidate for breast cancer treatment, specifically for subtypes represented by MCF7 cells.

KLF11 promotes the proliferation of breast cancer cells by inhibiting p53-MDM2 signaling.

Abnormal Krüppel-like factor 11 (KLF11) expression is frequently found in tumor tissues and is associated with cancer prognosis, but its biological functions and corresponding mechanisms remain elusive. Here, we demonstrated that KLF11 functions as an oncoprotein to promote tumor proliferation in breast cancer cells. Mechanistically, at the transcription level, KLF11 decreased TP53 mRNA expression. Notably, KLF11 also interacted with and stabilized MDM2 through inhibiting MDM2 ubiquitination and subsequent degradation. This increase in MDM2 in turn accelerated the ubiquitin-mediated proteolysis of p53, leading to the reduced expression of p53 and its target genes, including CDKN1A, BAX, and NOXA1. Accordingly, data from animals further confirmed that KLF11 significantly upregulated the growth of breast cancer cells and was inversely correlated with p53 expression. Taken together, our findings reveal a novel mechanism for breast cancer progression in which the function of the tumor suppressor p53 is dramatically weakened.

Primary Cardiac Intimal Sarcoma: Multi-Layered Strategy and Core Role of MDM2 Amplification/Co-Amplification and MDM2 Immunostaining.

Primary cardiac tumours are relatively uncommon (75% are benign). Across the other 25%, representing malignant neoplasia, sarcomas account for 75-95%, and primary cardiac intimal sarcoma (PCIS) is one of the rarest findings. We aimed to present a comprehensive review and practical considerations from a multidisciplinary perspective with regard to the most recent published data in the specific domain of PCIS. We covered the issues of awareness amid daily practice clinical presentation to ultra-qualified management in order to achieve an adequate diagnosis and prompt intervention, also emphasizing the core role of MDM2 immunostaining and MDM2 genetic analysis. An additional base for practical points was provided by a novel on-point clinical vignette with MDM2-positive status. According to our methods (PubMed database search of full-length, English publications from January 2021 to March 2023), we identified three studies and 23 single case reports represented by 22 adults (male-to-female ratio of 1.2; male population with an average age of 53.75 years, range: 35-81; woman mean age of 55.5 years, range: 34-70) and a 4-year-old child. The tumour-related clinical picture was recognized in a matter of one day to ten months on first admission. These non-specific data (with a very low index of suspicion) included heart failure at least NYHA class II, mitral regurgitation and pulmonary hypertension, acute myocardial infarction, ischemic stroke, obstructive shock, and paroxysmal atrial fibrillation. Awareness might come from other complaints such as (most common) dyspnoea, palpitation, chest pressure, cough, asthenia, sudden fatigue, weakness, malaise, anorexia, weight loss, headache, hyperhidrosis, night sweats, and epigastric pain. Two individuals were initially misdiagnosed as having endocarditis. A history of prior treated non-cardiac malignancy was registered in 3/23 subjects. Distant metastasis as the first step of detection (n = 2/23; specifically, brain and intestinal) or during follow-up (n = 6/23; namely, intestinal, brain and bone, in two cases for each, and adrenal) required additional imagery tools (26% of the patients had distant metastasis). Transoesophageal echocardiography, computed tomography (CT), magnetic resonance imagery, and even 18F-FDG positronic emission tomography-CT (which shows hypermetabolic lesions in PCIS) represent the basis of multimodal tools of investigation. Tumour size varied from 3 cm to ≥9 cm (average largest diameter of 5.5 cm). The most frequent sites were the left atrium followed by the right ventricle and the right atrium. Post-operatory histological confirmation was provided in 20/23 cases and, upon tumour biopsy, in 3/23 of them. The post-surgery maximum free-disease interval was 8 years, the fatal outcome was at the earliest two weeks since initial admission. MDM2 analysis was provided in 7/23 subjects in terms of MDM2-positive status (two out of three subjects) at immunohistochemistry and MDM2 amplification (four out of five subjects) at genetic analysis. Additionally, another three studies addressed PCISs, and two of them offered specific MDM2/MDM2 assays (n = 35 patients with PCISs); among the provided data, we mention that one cohort (n = 20) identified a rate of 55% with regard to MDM2 amplification in intimal sarcomas, and this correlated with a myxoid pattern; another cohort (n = 15) showed that MDM2-positive had a better prognostic than MDM2-negative immunostaining. To summarize, MDM2 amplification and co-amplification, for example, with MDM4, CDK4, HMGA3, CCND3, PDGFRA, TERT, KIT, CCND3, and HDAC9, might improve the diagnosis of PCIS in addition to MDM2 immunostaining since 10-20% of these tumours are MDM2-negative. Further studies are necessary to highlight MDM2 applicability as a prognostic factor and as an element to be taken into account amid multi-layered management in an otherwise very aggressive malignancy.

p53/MDM2 signaling pathway in aging, senescence and tumorigenesis.

A wealth of evidence has emerged that there is an association between aging, senescence and tumorigenesis. Senescence, a biological process by which cells cease to divide and enter a status of permanent cell cycle arrest, contributes to aging and aging-related diseases, including cancer. Aging populations have the higher incidence of cancer due to a lifetime of exposure to cancer-causing agents, reduction of repairing DNA damage, accumulated genetic mutations, and decreased immune system efficiency. Cancer patients undergoing cytotoxic therapies, such as chemotherapy and radiotherapy, accelerate aging. There is growing evidence that p53/MDM2 (murine double minute 2) axis is critically involved in regulation of aging, senescence and oncogenesis. Therefore, in this review, we describe the functions and mechanisms of p53/MDM2-mediated senescence, aging and carcinogenesis. Moreover, we highlight the small molecular inhibitors, natural compounds and PROTACs (proteolysis targeting chimeras) that target p53/MDM2 pathway to influence aging and cancer. Modification of p53/MDM2 could be a potential strategy for treatment of aging, senescence and tumorigenesis.

Genetic variability profiling of the p53 signaling pathway in chronic lymphocytic leukemia. Individual and combined analysis of TP53, MDM2 and NQO1 gene variants.

TP53 gene disruption, including 17p13 deletion [del(17p)] and/or TP53 mutations, is a negative prognostic biomarker in chronic lymphocytic leukemia (CLL) associated with disease progression, treatment failure and shorter survival. Germline variants in p53 signaling pathway genes could also lead to p53 dysfunction, but their involvement in CLL has not been thoroughly evaluated. The aim of this study was to determine the association of TP53, MDM2 and NQO1 gene variability with clinical and genetic data of CLL patients. Individual genotype and haplotype data of CLL patients were compared with clinical prognostic factors, cytogenetic and molecular cytogenetic findings as well as IGHV and TP53 mutational status. The study included 116 CLL patients and 161 healthy blood donors. TP53 (rs1042522, rs59758982, rs1625895), NQO1 (rs1800566) and MDM2 (rs2279744, rs150550023) variants were genotyped using different PCR approaches. Analysis of genotype frequencies revealed no association with the risk of CLL. TP53 rs1042522, rs1625895 and MDM2 rs2279744 variants were significantly associated with abnormal karyotype and the presence of del(17p). Similarly, these two TP53 variants were associated with TP53 disruption. Moreover, TP53 C-A-nondel and G-A-del haplotypes (rs1042522-rs1625895-rs59758982) were associated with an increased likelihood of carrying del(17p) and TP53 disruptions. MDM2 T-nondel haplotype (rs2279744-rs150550023) was found to be a low risk factor for del(17p) (OR = 0.32; CI: 0.12-0.82; p = 0.02) and TP53 disruptions (OR = 0.41; CI: 0.18-0.95; p = 0.04). Our findings suggest that TP53 and MDM2 variants may modulate the risk to have chromosome alterations and TP53 disruptions, particularly del(17p). To our knowledge this is the first study of several germline variants in p53 pathway genes in Argentine patients with CLL.

EVA1A reverses lenvatinib resistance in hepatocellular carcinoma through regulating PI3K/AKT/p53 signaling axis.

Lenvatinib is a commonly used first-line drug for the treatment of advanced hepatocellular carcinoma (HCC). However, its clinical efficacy is limited due to the drug resistance. EVA1A was a newly identified tumor suppressor, nevertheless, the impact of EVA1A on resistance to lenvatinib treatment in HCC and the potential molecular mechanisms remain unknown. In this study, the expression of EVA1A in HCC lenvatinib-resistant cells is decreased and its low expression was associated with a poor prognosis of HCC. Overexpression of EVA1A reversed lenvatinib resistance in vitro and in vivo, as demonstrated by its ability to promote cell apoptosis and inhibit cell proliferation, invasion, migration, EMT, and tumor growth. Silencing EVA1A in lenvatinib-sensitive parental HCC cells exerted the opposite effect and induced resistance to lenvatinib. Mechanistically, upregulated EVA1A inhibited the PI3K/AKT/MDM2 signaling pathway, resulting in a reduced interaction between MDM2 and p53, thereby stabilizing p53 and enhancing its antitumor activity. In addition, upregulated EVA1A suppressed the PI3K/AKT/mTOR signaling pathway and promoted autophagy, leading to the degradation of mutant p53 and attenuating its oncogenic impact. On the contrary, loss of EVA1A activated the PI3K/AKT/MDM2 signaling pathway and inhibited autophagy, promoting p53 proteasomal degradation and mutant p53 accumulation respectively. These findings establish a crucial role of EVA1A loss in driving lenvatinib resistance involving a mechanism of modulating PI3K/AKT/p53 signaling axis and suggest that upregulating EVA1A is a promising therapeutic strategy for alleviating resistance to lenvatinib, thereby improving the efficacy of HCC treatment.

Intraperitoneal Liposarcoma: A Case Report and Literature Review of a Rare Entity.

Liposarcoma is a rare soft-tissue neoplasm originating from adipocytes. The exact cause of liposarcoma is unknown and symptoms vary depending on the tumor's location. A 49-year-old man presented to the emergency room complaining of epigastric pain radiating to the back and right upper quadrant. Cross-sectional imaging revealed a large upper abdominal mass that was thought to be a gastrointestinal stromal tumor (GIST) arising from the duodenum at first. The patient underwent en-bloc resection of the mass and was planned for adjuvant chemotherapy. Subsequently, multiple tissue samples were examined, leading to the final diagnosis of de-differentiated liposarcoma. The patient eventually developed multiple recurrences and was subjected to re-resection surgeries and three different chemotherapy regimens. Given the rarity of the disease, no standardized therapy plan is available, highlighting the need for more case reports/series and trials to broaden our understanding of this disease.

An overview of PROTACs targeting MDM2 as a novel approach for cancer therapy.

MDM2 genes amplification or altered expression is commonly observed in various cancers bearing wild-type TP53. Directly targeting the p53-binding pocket of MDM2 to activate the p53 pathway represents a promising therapeutic approach. Despite the development of numerous potent MDM2 inhibitors that have advanced into clinical trials, their utility is frequently hampered by drug resistance and hematologic toxicity such as neutropenia and thrombocytopenia. The emergence of PROTAC technology has revolutionized drug discovery and development, with applications in both preclinical and clinical research. Harnessing the power of PROTAC molecules to achieve MDM2 targeted degradation and p53 reactivation holds significant promise for cancer therapy. In this review, we summarize representative MDM2 PROTAC degraders and provide insights for researchers investigating MDM2 proteins and the p53 pathway.