Extrachromosomal circular DNA promotes prostate cancer progression through the FAM84B/CDKN1B/MYC/WWP1 axis.

BACKGROUND: Extrachromosomal circular DNA (eccDNA), a kind of circular DNA that originates from chromosomes, carries complete gene information, particularly the oncogenic genes. This study aimed to examine the contributions of FAM84B induced by eccDNA to prostate cancer (PCa) development and the biomolecules involved. METHODS: The presence of eccDNA in PCa cells and the FAM84B transcripts that eccDNA carries were verified by outward and inward PCR. The effect of inhibition of eccDNA synthesis on FAM84B expression in PCa cells was analyzed by knocking down Lig3. The impact of FAM84B on the growth and metastases of PCa cells was verified by Cell Counting Kit-8 (CCK8), EdU, transwell assays, and a xenograft mouse model. Chromatin immunoprecipitation quantitative PCR (ChIP-qPCR) and dual-luciferase reporter assays were carried out to examine the effect of FAM84B/MYC on WWP1 transcription, and a co-immunoprecipitation (Co-IP) assay was conducted to verify the modification of CDKN1B by WWP1. The function of this molecular axis in PCa was explored by rescue assays. RESULTS: The inhibited eccDNA synthesis significantly downregulated FAM84B in PCa cells, thereby attenuating the growth and metastasis of PCa. FAM84B promoted the transcription of WWP1 by MYC by activating the expression of MYC coterminous with the 8q24.21 gene desert in a beta catenin-dependent approach. WWP1 transcription promoted by MYC facilitated the ubiquitination and degradation of CDKN1B protein and inversely attenuated the repressive effect of CDKN1B on MYC expression. Exogenous overexpression of CDKN1B blocked FAM84B-activated MYC/WWP1 expression, thereby inhibiting PCa progression. CONCLUSIONS: FAM84B promoted by eccDNA mediates degradation of CDKN1B via MYC/WWP1, thereby accelerating PCa progression.

In Vitro Cultivation for Glugea plecoglossi (Microsporidia) Isolated from Ayu (Plecoglossus altivelis).

Glugea plecoglossi is an obligate intracellular microsporidium, which poses a significant threat to ayu (Plecoglossus altivelis). In vitro cultivation models are invaluable tools for investigating intracellular microorganisms, including G. plecoglossil. In this study, we attempted to in vitro cultivate G. plecoglossi using primary cultures derived from ayu monocytes/macrophages (MO/MΦ), a murine-derived macrophage cell line RAW264.7, and the epithelioma papulosum cyprini (EPC) cell line. The results demonstrated that MO/MΦ infected with spores exhibited a pronounced immune response which was presented by rapidly high expression levels of inflammatory cytokines, such as PaIL-1ß, PaTNF-α, PaIL-10, and PaTGF-ß, and detached within 96 h post-infection (hpi). Infected RAW264.7 cells remained capable of stable passage yet exhibited cellular deformation with a decrease in intracellular spores occurring around 8 days post-infection (dpi). In contrast, EPC cells promised a substantial parasite population, and the cytokine expression levels returned to normal by 8 dpi. In addition, G. plecoglossi spores recovered from EPC cells could infect young ayu, suggesting that EPC cells might be used as an in vitro cultivation system for G. plecoglossi.

Effect of Sequence of Radiotherapy Combined With Immunotherapy on the Incidence of Pneumonitis in Patients With Lung Cancer: A Systematic Review and Network Meta-Analysis.

BACKGROUND: With the widespread application of immune checkpoint inhibitor (ICI) combined with radiotherapy (RT) for the treatment of lung cancer, increasing attention has been paid to treatment-related pneumonitis. The effect of the treatment sequence on the incidence of pneumonitis remains unclear. METHODS: We searched databases including PubMed, Embase, and ClinicalTrials.gov, meeting abstracts, and reference lists of relevant review articles for literature published on radio- and immunotherapy in lung cancer. Stata software (version 16.0) was used for meta-analysis. Data on the incidence of any grade and ≥ grade 3 pneumonitis was pooled using the random effects model. Bayesian network meta-analysis was used for arm-based pairwise comparisons. Subgroup analyses were performed to identify the potential influencing factors. RESULTS: Thirty-eight studies met our inclusion criteria. The network meta-analysis showed no significant difference between the incidence of pneumonitis in concurrent ICI with RT (concurrent arm) and RT followed by ICI (RT-first arm) (odds ratio [OR]: 0.71, 95% confidence interval [CI]: 0.10-4.81). In the meta-analysis of single group rates, RT following ICI (ICI-first arm) exhibited higher incidence of any grade pneumonitis compared with concurrent- and RT-first arms, with 0.321 (95% CI: 0.260-0.386) for programmed cell death protein 1 (PD-1) inhibitors from clinical trials, and 0.480 (95% CI: 0.363-0.598) for PD-1 inhibitors from real-world retrospective data, respectively. CONCLUSION: No significant difference in the incidence of any grade and grade ≥ 3 pneumonitis was found between RT-first and concurrent arms. The ICI-first arm exhibited a higher incidence of pneumonitis, which needs to be further confirmed by follow-up studies.

Dual-Antigen-Displaying Nanovaccines Elicit Synergistic Immunoactivation for Treating Cancer and Preventing Infectious Complications.

As one of the most common complications, infection causes the majority of mortality in cancer patients. However, therapeutic strategies that can simultaneously suppress tumors and protect patients from infection have been rarely reported. Here, the use of dual-antigen-displaying nanovaccines (DADNs) is described to elicit synergistic immunoactivation for treating cancer and preventing infectious complications. DADNs are prepared by wrapping immunoadjuvant-loaded nanoparticles with a hybrid coating, which is fused from cell membranes that are separately genetically engineered to express tumor and infectious pathogenic antigens. Due to the presence of a dual-antigen combination, DADNs are able to promote the maturation of dendritic cells and more importantly to trigger cross-presentation of both combined antigens. During in vivo investigations, we find that DADNs can reverse immunosuppression by stimulating tumor-associated antigen-specific T-cell responses, resulting in significantly delayed tumor growth in mice. These nanovaccines also elicit effective protective immunity against tumor challenges and induce robust production of pathogenic antigen-specific immunoglobulin G antibody in a prophylactic study. This work offers a unique approach to develop dual-mode vaccines, which are promising for synchronously treating cancer and preventing infection.

Chemoradiotherapy combined with immunotherapy in stage III non-small cell lung cancer: a systematic review and meta-analysis of efficacy and safety outcomes.

Background Since the success of the PACIFIC trial, durvalumab has become the clear standard of care for many patients with stage III non-small cell lung cancer (NSCLC) after concurrent chemoradiotherapy (CRT). However, the duration of immune consolidation and the efficacy and safety of different immune agents remain unclear. We conducted a systematic review of relevant studies. Methods We searched all the relevant studies in PubMed, Embase and Cochrane Library databases. We also reviewed abstracts of relevant conferences, to prevent omissions. The meta-analysis was performed using Stata version 16.0. Results Chemoradiotherapy combined with immunotherapy can improve PFS (HR: 0.60, 95%CI :0.55-0.60) and OS (HR: 0.59, 95%CI :0.53-0.66) compared with no immunotherapy. The pooled 24-month PFS and 24-month OS rates were 48.1% (95% CI, 43.5%-52.7%) and 71.3% (95% CI, 67.3%-75.2%), respectively. Subgroup analysis showed that 24-month OS rates were 60.7% (95%CI, 51.0%-70.3%) and 77.4% (95%CI, 73.2%-81.7%) at 1 year and 2 years of immune consolidation, respectively. The pooled 1-year completion rate for immune consolidation was 35.6% (95%CI, 31.3%-39.8%). The pooled rate of pneumonitis for all grades was 41.7% (95%CI, 31.9%-51.9%). The pooled rate of pneumonitis ≥ grade 3 was 6.7% (95%CI, 5.0%-8.5%). The incidence of pneumonitis ≥ grade 3 after 1 year of immunotherapy is 4.8% (95%CI, 3.1%-6.5%). The incidence of pneumonitis ≥ grade 3 after 2 years of immunotherapy is 5.1% (95%CI, 2.9%-7.3%). Conclusions Prolonging the duration of immunotherapy consolidation increases survival benefits in patients with stage III NSCLC without causing higher side effects. Older patients, due to high incidence of pneumonia and low immunotherapy completion rate, have less survival benefit.

Parallel detection of multiple zoonotic parasites using a real-time fluorogenic loop-mediated isothermal amplification-based quadruple-sample microfluidic chip.

Zoonotic parasites pose significant health risks globally. In the present study, we combined a microfluidic chip with loop-mediated isothermal amplification (on-chip LAMP) to detect five zoonotic parasites: Toxoplasma gondii, Cryptosporidium parvum, Cryptosporidium hominis, Clonorchis sinensis, and Taenia solium. This method enabled the simultaneous parallel analysis of five genetic markers from a maximum of four samples per chip. The on-chip LAMP assay was conducted in a highly automated format via the addition (by pipetting) of each sample in a single operation. The reaction was performed in volumes as low as 5 µL at a temperature of 65°C for 60 min, achieving limits of detection ranging from 10-2 to 10-3 pg./µL of recombinant plasmid DNA. All the time-to-positive values were less than 40 min, and almost all the coefficients of variation were less than 10%, even when using limit of detection concentrations for multiple pathogens, indicating robust reproducibility among replicates. The clinical sensitivity and specificity for detecting 135 field samples were 98.08 and 97.59%, respectively, compared with traditional biological methods, indicating good applicability in the detection of field samples. This on-chip LAMP assay allows for low reagent consumption, ease of operation, and multiple analyses of samples and genetic targets, and is applicable for on-site detection and the routine monitoring of multiple zoonotic parasites.

Advances in anti-tumor based on various anaerobic bacteria and their derivatives as drug vehicles.

Cancer therapies, such as chemotherapy and radiotherapy, are often unsatisfactory due to several limitations, including drug resistance, inability to cross biological barriers, and toxic side effects on the body. These drawbacks underscore the need for alternative treatments that can overcome these challenges and provide more effective and safer options for cancer patients. In recent years, the use of live bacteria, engineered bacteria, or bacterial derivatives to deliver antitumor drugs to specific tumor sites for controlled release has emerged as a promising therapeutic tool. This approach offers several advantages over traditional cancer therapies, including targeted drug delivery and reduced toxicity to healthy tissues. Ongoing research in this field holds great potential for further developing more efficient and personalized cancer therapies, such as E. coli, Salmonella, Listeria, and bacterial derivatives like outer membrane vesicles (OMVs), which can serve as vehicles for drugs, therapeutic proteins, or antigens. In this review, we describe the advances, challenges, and future directions of research on using live bacteria or OMVs as carriers or components derived from bacteria of delivery systems for cancer therapy.

M6A-mediated upregulation of HOXC10 promotes human hepatocellular carcinoma development through PTEN/AKT/mTOR signaling pathway.

Human Hox genes (Homeobox) play a crucial role in embryonic development and cancer. The HOXC10 gene, a member of the HOX family, has been reported abnormally expressed in several cancers. However, the association between HOXC10 and hepatocellular carcinoma (HCC) remains to be elucidated. In the present study, tissue microarray cohort data showed that high levels of HOXC10 expression predicted a poor survival in HCC patients. Meanwhile, HOXC10 was significantly upregulated in the Huh7 cell line compared with the well differentiated cell line HepG2 and human normal liver cells. Functionally, silencing HOXC10 in Huh7 cells inhibited cell proliferation, increased apoptosis, and inhibited invasion and migration of HCC cells. HOXC10 overexpression in HepG2 cells increased cell proliferation, decreased apoptosis, and increased invasion and migration of HCC cells. In the HepG2 xenograft models, HOXC10 increased the tumor volume and weight compared with control. Mechanistically, the m6A modification of HOXC10 by METTL3 enhanced its expression by enhancing its mRNA stability. Both the in vitro and in vivo results showed that overexpressed HOXC10 activated the PTEN/AKT/mTOR pathway. In summary, the findings highlight the importance of HOXC10 in the regulation of HCC progression. HOXC10 is potentially a future therapeutic target for HCC treatment.

Targeting complement C5a to improve radiotherapy sensitivity in non-small cell lung cancer.

Background: Tumor local and distant relapse recurrence after radiotherapy (RT) is one of the critical factors leading to poor prognosis. The effective antitumor effects of RT are dependent upon the participation of innate and adaptive components of the immune system. C5a/C5aR1 signaling can regulate antitumor immune effect in the tumor microenvironment (TME). Thus, exploring the changes and mechanism in the TME induced by RT-mediated complement activation may provide a novel perspective for reversing radioresistance. Methods: First, fractionated radiation of 8 Gy ×3 fractions were targeted at Lewis lung carcinoma (LLC) tumor-bearing female mice to measure the infiltration of CD8+ T cell and analyze the RNA sequencing (RNA-seq) in RT-recruited CD8+ T cells. Second, tumor growth was measured in LLC tumor-bearing mice treated with RT either with or without C5aR1 inhibitor to clarify the antitumor effect of RT combined with C5aR1 inhibitor. Third, we detected the expression of C5a/C5aR1 and their signaling pathways on radiated tumor tissues. Furthermore, we investigated the expression of C5a in tumor cells at different time points after different doses of RT. Results: In our system, RT induced the increased infiltration of CD8+ T cells and local activation of complement C5a/C5aR. Concurrent administration of RT and blocking of C5aR improved radiosensitivity and tumor-specific immune response, which was reflected by high C5aR expression in CD8+ T cells. The AKT/NF-κB pathway was found to be an important signaling pathway in C5a/C5aR axis mediation by RT. Conclusions: RT promotes the release of C5a from tumor cells and leads to up-regulation of C5aR1 expression via the AKT/NF-κB pathway. Inhibition of the combination of complement C5a and C5aR could improve RT sensitivity. Our work provides evidence that the combination of RT and C5aR blockade opens a new window of opportunity to promote anti-tumor therapeutic effects in lung cancer.

Pseudoprogression during immunotherapy for gastric adenocarcinoma: A case report and literature review.

Immunotherapy is a novel treatment option for various types of cancers. However, the optimal timing for response evaluation has not been well defined. Here, we present a gastric cancer (GC) patient with microsatellite instability-high who experienced recurrence 5 years and 11 months after radical gastrectomy. Then, the patient was treated with radiotherapy, targeted drugs, and immunotherapy. Immunotherapy resulted in 5 months of continuous progression, accompanied by significantly increased tumor marker CA19-9. However, the patient exhibited a satisfactory response without altering the treatment. Based on this, we hypothesized that some persistent progression with elevated tumor markers, known as pseudoprogression (PsP), might be observed in patients with recurrent GC during immunotherapy. This process might be prolonged, but if the treatment is continued, it will eventually produce remarkable therapeutic effects. PsP might challenge the globally accepted immune response evaluation criteria for solid tumors.

Ferritin in cancer therapy: A pleiotropic tumoraffin nanocage-based transport.

BACKGROUND: Ferritin, a ubiquitously distributed iron storage protein, can specifically target tumor cells through transferrin receptor 1. Due to its rearrangeable nanocage structure, ferritin can be loaded with anticancer drugs. Combined with amino acid modifications on the outer- and/or inner-spaces of the nanocage, ferritins can be further coupled with antigens, antibodies, and nucleotide sequences. Since ferritin is naturally presented in the human body, when used in vivo, ferritin exhibits good biocompatibility, and no immunogenic response occurs. These makes ferritin an ideal nanocarrier which shows broad application prospects in cancer therapy. METHODS: In this study, to find articles, a search was made in PubMed with the keywords ferritin, drug delivery, drug delivery, and cancer treatment. RESULTS: According to the investigation, some studies suggest that ferritin can be loaded with drugs and targeted for delivery to tumor tissue. Therefore, ferritin nanocarriers loaded with drugs can be used in chemotherapy, photodynamic therapy (PDT), photothermal therapy (PTT) and immunotherapy. Importantly, the specific targeting of ferritin nanocarriers to tumor cells increases the effectiveness of related therapies and reduces side effects. CONCLUSIONS: We conclude in this paper that the superior properties of ferritin nanocarriers as an emerging drug delivery system make them a promising cancer treatment strategy. In the future, it is worth conducting clinical trials to further investigate the safety and efficacy of ferritin nanocarriers in patients.

Development and validation of a radiomics-based nomogram for the prediction of postoperative malnutrition in stage IB1-IIA2 cervical carcinoma.

Objective: In individuals with stage IB1-IIA2 cervical cancer (CC) who received postoperative radiotherapy ± chemotherapy (PORT/CRT), the interaction between sarcopenia and malnutrition remains elusive, let alone employing a nomogram model based on radiomic features of psoas extracted at the level of the third lumbar vertebra (L3). This study was set to develop a radiomics-based nomogram model to predict malnutrition as per the Patient-Generated Subjective Global Assessment (PG-SGA) for individuals with CC. Methods: In total, 120 individuals with CC underwent computed tomography (CT) scans before PORT/CRT. The radiomic features of psoas at L3 were obtained from non-enhanced CT images. Identification of the optimal features and construction of the rad-score formula were conducted utilizing the least absolute shrinkage and selection operator (LASSO) logistic regression to predict malnutrition in the training dataset (radiomic model). Identification of the major clinical factors in the clinical model was performed by means of binary logistic regression analysis. The radiomics-based nomogram was further developed by integrating radiomic signatures and clinical risk factors (combined model). The receiver operating characteristic (ROC) curves and decision curves analysis (DCA) were employed for the evaluation and comparison of the three models in terms of their predictive performance. Results: Twelve radiomic features in total were chosen, and the rad-score was determined with the help of the non-zero coefficient from LASSO regression. Multivariate analysis revealed that besides rad-score, age and Eastern Cooperative Oncology Group performance status could independently predict malnutrition. As per the data of this analysis, a nomogram prediction model was constructed. The area under the ROC curves (AUC) values of the radiomic and clinical models were 0.778 and 0.847 for the training and 0.776 and 0.776 for the validation sets, respectively. An increase in the AUC was observed up to 0.972 and 0.805 in the training and validation sets, respectively, in the combined model. DCA also confirmed the clinical benefit of the combined model. Conclusion: This radiomics-based nomogram model depicted potential for use as a marker for predicting malnutrition in stage IB1-IIA2 CC patients who underwent PORT/CRT and required further investigation with a large sample size.

Impact of marital status on overall survival in patients with early-stage hepatocellular carcinoma.

The purpose of the present research was to assess the prognostic impact of marital status in hepatocellular carcinoma (HCC) patients with tumors ≤ 2 cm (stage Ia) based on the data from the Surveillance, Epidemiology, and End Results (SEER) database. Patients who received a histopathologic HCC diagnosis between 2004 and 2016 were recruited. Overall survival (OS) was the major outcome measure. The Cox regression model and the Fine-Gray regression model were used for the purpose of comparing and examining the prognostic value of marital status for OS. The data for a total of 2446 stage Ia HCC patients were extracted from the database. The median overall survival time was 96.0 months, with 5-year and 10-year overall survival rates of 58.2% and 45.8%, respectively. In both the Fine-Gray regression model and Cox regression model, marital status [married vs. unmarried and others, both P < 0.001, hazard ratio (HR) = 1.389 for Cox and HR = 1.378 for Fine-Gray], age at diagnosis, tumor grade, and surgery at the primary site independently served as prognostic indicators associated with OS. In conclusion, positive marital status was independently associated with better OS for stage Ia HCC patients, and its prognostic influence should be validated in the near future.

Survival Comparison Between Squamous Cell Carcinoma and Adenocarcinoma for Radiotherapy-Treated Patients with Stage IIB-IVA Cervical Cancer.

Objective: To compare the prognostic significance of adenocarcinoma (AC) with squamous cell carcinoma (SCC) on overall survival (OS) in patients with stage IIB-IVA cervical cancer (CC) treated by external beam radiotherapy (EBRT) and brachytherapy (BRT) with/without chemotherapy registered in the Surveillance, Epidemiology, and End Results database. Methods: Data of eligible patients were extracted between 2004 and 2016. A univariate analysis was conducted using the cumulative incidence function (CIF) by considering competing events and compared using Gray's test. The significant variables in univariate analysis were further evaluated in a multivariate analysis performed with the Fine-Gray regression model. Propensity score matching (PSM) analysis was also employed to reconfirm the results found in the present study. Results: A total of 2,243 patients with SCC and 176 patients with AC were extracted from the database. The 5-year OS rates were 57.8% in the SCC group and 52.8% in the AC group. 149 patients died of causes other than CC-considered as competing events. Compared with the SCC group, patients diagnosed with AC had statistically significant worse 5-year OS rate before and after PSM. In the multivariate Fine-Gray regression model, the histological subtype of AC was proven as an independent prognostic factor associated with poorer OS before [hazard ratio (HR) = 1.340; 95% confidence interval (CI): 1.081-1.660; P = 0.007] and after [HR = 1.376; 95% CI: 1.107-1.711; P = 0.004] PSM. Conclusions: The histological subtype of AC is significantly correlated with impaired OS as an independent prognostic variable in patients with stage IIB-IVA CC who received EBRT and BRT compared to patients with SCC. Future studies should incorporate effective and individualized treatment strategies into clinical decision-making to improve the unsatisfactory survival outcomes for patients with AC.

Targeting Epithelial-to-Mesenchymal Transition in Radioresistance: Crosslinked Mechanisms and Strategies.

Radiotherapy exerts a crucial role in curing cancer, however, its treatment efficiency is mostly limited due to the presence of radioresistance. Epithelial-to-mesenchymal transition (EMT) is a biological process that endows the cancer cells with invasive and metastatic properties, as well as radioresistance. Many potential mechanisms of EMT-related radioresistance being reported have broaden our cognition, and hint us the importance of an overall understanding of the relationship between EMT and radioresistance. This review focuses on the recent progresses involved in EMT-related mechanisms in regulating radioresistance, irradiation-mediated EMT program, and the intervention strategies to increase tumor radiosensitivity, in order to improve radiotherapy efficiency and clinical outcomes of cancer patients.

Biomimetic Nanoparticles Enabled by Cascade Cell Membrane Coating for Direct Cross-Priming of T Cells.

Despite the activation of T lymphocytes by antigen-presenting cells being responsible for eliciting antigen-specific immune responses, their crosstalking suffers from temporospatial limitations and endogenous influencing factors, which restrict the generation of a strong antitumor immunity. Here, cascade cell membrane coating is reported to prepare biomimetic nanoparticles (BNs) that can manipulate the cross-priming of T cells. BNs are obtained from coating nanoparticulate substrates with cell membranes extracted from dendritic cells (DCs) that are pre-pulsed with cancer cell membrane-coated nanoparticles. With a DC membrane that presents an array of cancer cell membrane antigen epitopes, BNs inherit the intrinsic membrane function of DCs, which can directly cross-prime T cells and provoke robust yet antigen-specific antitumor responses in multiple mouse models. Combination with clinical anti-programmed death-1 antibodies demonstrates a robust way of BNs to achieve desirable tumor regression and survival rate. This work spotlights the impact of nanoparticles on direct cross-priming of T cells and supports a unique yet modulate platform for boosting an effective adaptive immunity for immunotherapy.

Systemic antiviral immunization by virus-mimicking nanoparticles-decorated erythrocytes.

New vaccine technologies are urgently needed to produce safe and effective vaccines in a more timely manner to prevent future infectious disease pandemics. Here, we describe erythrocyte-mediated systemic antiviral immunization, a versatile vaccination strategy that boosts antiviral immune responses by using erythrocytes decorated with virus-mimetic nanoparticles carrying a viral antigen and a Toll-like receptor (TLR) agonist. As a proof of concept, polydopamine nanoparticles were synthesized via a simple in situ polymerization in which the nanoparticles were conjugated with the SARS-CoV-2 spike protein S1 subunit and the TLR7/8 agonist R848. The resulting SARS-CoV-2 virus-mimetic nanoparticles were attached to erythrocytes via catechol groups on the nanoparticle. Erythrocytes naturally home to the spleen and interact with the immune system. Injection of the nanoparticle-decorated erythrocytes into mice resulted in greater maturation and activation of antigen-presenting cells, humoral and cellular immune responses in the spleen, production of S1-specific immunoglobulin G (IgG) antibodies, and systemic antiviral T cell responses than a control group treated with the nanoparticles alone, with no significant negative side effects. These results show that erythrocyte-mediated systemic antiviral immunization using viral antigen- and TLR agonist-presenting polydopamine nanoparticles-a generalizable method applicable to many viral infections-is effective new approach to developing vaccines against severe infectious diseases.

Renal NKCC2 Is Dual Regulated by the Synergy of 20-HETE and High-Fat Diet in CYP4F2 Transgenic Mice.

INTRODUCTION: 20-Hydroxyeicosatetraenoic acid (20-HETE) is the metabolite of cytochrome P450, which modulates blood pressure by inhibiting renal sodium transport. However, the molecular mechanisms underlying the role of 20-HETE in the development of obesity-related hypertension remain unclear, necessitating this study. METHODS: Cytochrome P450 4F2 (CYP4F2) transgenic mice fed high-fat diet (HFD) were used as research animal models. The expression of renal ion transport molecules targeted by 20-HETE was evaluated by real-time PCR and Western blot (WB). The regulatory effect of 20-HETE and HFD on renal Na+-K+-2Cl- cotransporter, isoform 2 (NKCC2) was explored by immunoprecipitation, WB, and luciferase assay. RESULTS: A 2-week HFD feeding dramatically decreased protein abundance but increased renal NKCC2 mRNA expression in CYP4F2 transgenic mice. The decrease in NKCC2 protein was demonstrated to be due to ubiquitination induced by the synergy between 20-HETE and HFD. The increased PPAR-γ protein in CYP4F2 transgenic mice fed HFD and the activation of rosiglitazone on the luciferase reporter construct of the NKCC2 promoter demonstrated that the increase in NKCC2 mRNA in CYP4F2 transgenic mice fed HFD was a consequence of elevated PPAR-γ protein induced by the synergy between 20-HETE and HFD. CONCLUSIONS: Our data demonstrated that the synergy between 20-HETE and HFD could decrease NKCC2 protein via posttranslational ubiquitination, which was thought to be the main mechanism underlying the short-term effect in response to HFD and might be responsible for the adaptive modulation of renal NKCC2 to resist sodium retention. Moreover, the increased NKCC2 mRNA expression via PPAR-γ-induced transcriptional regulation was thought to be the main mechanism underlying the long-term effect in response to HFD and plays a pivotal role in the development of obesity-related hypertension.