Choroidal and retinal vascular changes in HLA-B27-associated anterior uveitis.

PURPOSE: To quantitatively analyze choroidal and retinal vascular changes in HLA-B27-associated anterior uveitis. STUDY DESIGN: A retrospective study. METHODS: Medical records of 51 eyes with unilateral HLA-B27-associated anterior uveitis, their fellow eyes and 47 sex and age-matched healthy eyes were retrospectively reviewed. Their choroidal and retinal vasculature were analyzed using swept-source (SS) optical coherence tomography (OCT) and OCT angiography (OCTA) scans. RESULTS: Deep capillary plexus (DCP) vessel density (VD) (p < 0.001), choroidal vascularity index (CVI) (p = 0.012), and choriocapillary flow deficit (CCFD) (p < 0.001) of uveitic and fellow eye group were significantly higher than those of control group. On the contrary, superficial capillary plexus (SCP) VD (p < 0.001) of uveitic and fellow eye group were significantly lower than of control group. The vascular parameters of uveitis and fellow eye group showed no significant difference between uveitic and resolution period. CONCLUSION: Certain choroidal and retinal vascular parameters were significantly changed in both HLA-B27-associated anterior uveitis without posterior segment involvement and the quiet fellow eyes, suggesting their possible effects as a systemic inflammatory disorder.

Discovery of TCP-(MP)-caffeic acid analogs as a new class of agents for treatment of osteoclastic bone loss.

Inhibition of LSD1 was proposed as promising and attractive therapies for treating osteoporosis. Here, we synthesized a series of novel TCP-(MP)-Caffeic acid analogs as potential LSD1 inhibitors to assess their inhibitory effects on osteoclastogenesis by using TRAP-staining assay and try to explore the preliminary SAR. Among them, TCP-MP-CA (11a) demonstrated osteoclastic bone loss both in vitro and in vivo, showing a significant improvement in the in vivo effects compared to the LSD1 inhibitor GSK-LSD1. Additionally, we elucidated a mechanism that 11a and its precursor that 11e directly bind to LSD1/CoREST complex through FAD to inhibit LSD1 demethylation activity and influence its downstream IκB/NF-κB signaling pathway, and thus regulate osteoclastic bone loss. These findings suggested 11a or 11e as potential novel candidates for treating osteoclastic bone loss, and a concept for further development of TCP-(MP)-Caffeic acid analogs for therapeutic use in osteoporosis clinics.

Decrease of alpha crystallin A by miR-325-3p in retinal cells under blue light exposure.

Exposure to blue light can lead to retinal degeneration, causing adverse effects on eye health. Although the loss of retinal cells due to blue light exposure has been observed, the precise molecular mechanisms underlying this process remain poorly understood. In this study, we investigate the role of alpha crystallin A (CRYAA) in neuro-retinal degeneration and their regulation by blue light. We observed significant apoptotic cell death in both the retina of rats and the cultured neuro-retinal cells. The expressions of Cryaa mRNA and protein were significantly down-regulated in the retina exposed to blue light. We identified that miR-325-3p reduces Cryaa mRNA and protein by binding to its 3'-untranslated region (UTR). Up-regulation of miR-325-3p destabilized Cryaa mRNA and suppresses CRYAA, whereas down-regulation of miR-325-3p increased both expressions. Blue light-induced neuro-retinal cell death was alleviated by CRYAA overexpression. These results highlight the critical role of Cryaa mRNA and miR-325-3p molecular axis in blue light-induced retinal degeneration. Consequently, targeting CRYAA and miR-325-3p presents a potential strategy for protecting against blue light-induced retinal degeneration.

Computational analysis of electrode structure and configuration for efficient and localized neural stimulation.

Neuromodulation technique using electric stimulation is widely applied in neural prosthesis, therapy, and neuroscience research. Various stimulation techniques have been developed to enhance stimulation efficiency and to precisely target the specific area of the brain which involves optimizing the geometry and the configuration of the electrode, stimulation pulse type and shapes, and electrode materials. Although the effects of electrode shape, size, and configuration on the performance of neural stimulation have individually been characterized, to date, there is no integrative investigation of how this factor affects neural stimulation. In this study, we computationally modeled the various types of electrodes with varying shapes, sizes, and configurations and simulated the electric field to calculate the activation function. The electrode geometry is then integratively assessed in terms of stimulation efficiency and stimulation focality. We found that stimulation efficiency is enhanced by making the electrode sharper and smaller. A center-to-vertex distance exceeding 100 µm shows enhanced stimulation efficiency in the bipolar configuration. Additionally, the separation distance of less than 1 mm between the reference and stimulation electrodes exhibits higher stimulation efficiency compared to the monopolar configuration. The region of neurons to be stimulated can also be modified. We found that sharper electrodes can locally activate the neuron. In most cases, except for the rectangular electrode shape with a center-to-vertex distance smaller than 100 µm, the bipolar electrode configuration can locally stimulate neurons as opposed to the monopolar configuration. These findings shed light on the optimal selection of neural electrodes depending on the target applications.

Exploratory analysis of choriocapillaris vasculature as a biomarker of idiopathic epiretinal membrane.

PURPOSE: To investigate the preoperative choriocapillaris perfusion (CCP) as a biomarker in patients with idiopathic epiretinal membrane (iERM). MATERIALS AND METHODS: 28 patients (28 eyes) with unilateral iERM who received pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling were included for retrospective observational study. Optical coherence tomography (OCT) and angiography (OCTA) was performed before and after PPV. Area, perimeter, and circularity of superficial foveal avascular zone (FAZ) were analyzed preoperatively in both eyes using OCTA. Preoperative CCP was also analyzed with binarized en-face OCTA images. Measurements of best-corrected visual acuity (BCVA) and central foveal thickness (CFT) by OCT were conducted at the baseline and 6 months following the surgery. The correlations of preoperative OCT parameters with postoperative BCVA and CFT reduction were analyzed. RESULTS: CCP was significantly lower (p < 0.001) and FAZ had shrunk (p < 0.001) in eyes with iERM compared to unaffected fellow eyes before surgery. BCVA and CFT became significantly improved after surgery (p = 0.001, p < 0.001). Multiple regression analysis revealed that preoperative CCP was significantly related with BCVA improvement (ß = 0.185, p = 0.005), postoperative BCVA (ß = 0.108, p = 0.023) and ratio of post- to preoperative CFT (ß = 0.106, p = 0.044). CONCLUSIONS: Preoperative CCP is a biomarker for poor functional and anatomical prognosis after surgery in iERM.

Genetically engineered long-acting Esculentin-2CHa(1-30) fusion protein with potential applicability for the treatment of NAFLD.

Esculentin-2CHa(1-30) (?ESC") has been reported as a potent anti-diabetic peptide with little toxicity. However, its very short plasma residence time severely limits the therapeutic efficacy. To address this issue, we genetically engineered a fusion protein of tandem trimeric ESC with an albumin binding domain (ABD) and a fusion partner, SUMO (named ?SUMO-3×ESC-ABD"). The SUMO-3×ESC-ABD, successfully produced from E. coli, showed low cellular and hemolytic toxicity while displaying potent activities for the amelioration of hyperglycemia as well as non-alcoholic fatty liver disease (NAFLD) in vitro. In animal studies, the estimated plasma half-life of SUMO-3×ESC-ABD was markedly longer (427-fold) than that of the ESC peptide. In virtue of the extended plasma residence, the SUMO-3×ESC-ABD could produce significant anti-hyperglycemic effects that lasted for >2 days, while both the ESC or ESC-ABD peptides elicited little effects. Further, twice-weekly treatment for 10 weeks, the SUMO-3×ESC-ABD displayed significant improvement in blood glucose control with a reduction in body weight. Most importantly, a significant improvement in the conditions of NAFLD was observed in the SUMO-3×ESC-ABD-treated mice. Along the systemic effects (by improved glucose tolerance and body weight reduction), direct inhibition of the hepatocyte lipid uptake was suggested as the major mechanism of the anti-NAFLD effects. Overall, this study demonstrated the utility of the long-acting SUMO-3×ESC-ABD as a potent drug candidate for the treatment of NAFLD.

Initial Low-Dose Hydroxyurea and Anagrelide Combination in Essential Thrombocythemia: Comparable Response with Lower Toxicity.

Background and Objectives: Essential thrombocythemia (ET) is a myeloproliferative neoplasm that overproduces platelets and is associated with life-threatening thrombosis. Medical cytoreduction either with hydroxyurea (HU) or anagrelide (AG) is widely used, but drug intolerance or resistance are major concerns. Low-dose combination of HU and AG as an alternative strategy has been explored in various studies. It showed comparable response with acceptable toxicity in second-line settings for patients who experienced side effects from prior monotherapy. In this study, we evaluated the efficacy and safety of upfront combination for ET patients. Materials and Methods: From January 2018 to June 2022, a total of 241 ET patients with intermediate to high risk were enrolled. We identified 21 patients with initial drug combinations and compared treatment outcomes and adverse events (AEs) between combination and monotherapy groups. Results: The median age was 62 years old (range, 26-87) and median platelet count was 912 × 109/L (range, 520-1720). Overall treatment response did not exhibit significant differences between the groups, although there was a trend towards a lower response rate in patients treated with AG alone at 3 months post-treatment (AG + HU, 85.7% vs. AG alone, 75.4%, p = 0.068). AEs of any grade occurred in 52.3% of the combination group, 44.3% of the HU monotherapy group, and 43.4% of the AG single group, respectively. Of note was that the HU plus AG combination group suffered a lower incidence of grade 3-4 AEs compared to the other two groups, with statistical significance (p = 0.008 for HU monotherapy vs. combination therapy and p < 0.01 for AG monotherapy vs. combination therapy). Conclusions: Our findings demonstrated that the upfront low-dose combination approach showed feasible clinical outcomes with significantly lower severe AEs compared to conventional monotherapy. These results may offer valuable insights to clinicians for future prospective investigations.

Analysis of retinal and choroidal microvascular changes using optical coherence tomography and optical coherence tomography angiography in patients with acute leukemia.

PURPOSE: Although leukemic retinopathy accounts for 80% of ocular complications in acute leukemia, its pathogenesis remains unclear. To evaluate changes in retinal and choroicapillaris and structural parameters in patients with acute leukemia, we analyzed the correlation between vascular perfusion metrics and laboratory parameters and assessed the changes after hematopoietic stem cell transplantation (HSCT). METHODS: Herein, 104 eyes of 52 patients aged 18 and above with acute leukemia were enrolled. 80 eyes of 40 healthy patients were recruited as control participants. All participants underwent optical coherence tomography (OCT) and OCT angiography (OCTA) at baseline. RESULTS: Patients with acute leukemia had a significantly thicker ganglion cell-inner plexiform layer (GCIPL) and lower circularity index than the control participants. Post-HSCT perfusion metrics did not differ significantly, but parafoveal thickness decreased significantly. During the active phase of acute leukemia, lower platelet levels were associated with significant GCIPL thickening and increased foveal avascular zone and perimeter. D-dimer levels positively correlated with GCIPL thickness. CONCLUSION: Patients with acute leukemia had subclinical retinal microvascular deficits on OCTA and GCIPL thickening on OCT, possibly associated with bone marrow function. GCIPL thickness may indicate acute ischemia in such patients. Further studies must elucidate their clinical and prognostic significance.

Deep learning model for differentiating acute myeloid and lymphoblastic leukemia in peripheral blood cell images via myeloblast and lymphoblast classification.

Objective: Acute leukemia (AL) is a life-threatening malignant disease that occurs in the bone marrow and blood, and is classified as either acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL). Diagnosing AL warrants testing methods, such as flow cytometry, which require trained professionals, time, and money. We aimed to develop a model that can classify peripheral blood images of 12 cell types, including pathological cells associated with AL, using artificial intelligence. Methods: We acquired 42,386 single-cell images of peripheral blood slides from 282 patients (82 with AML, 40 with ALL, and 160 with immature granulocytes). Results: The performance of EfficientNet-V2 (B2) using the original image size exhibited the greatest accuracy (accuracy, 0.8779; precision, 0.7221; recall, 0.7225; and F1 score, 0.7210). The next-best accuracy was achieved by EfficientNet-V1 (B1), with a 256 × 256 pixels image. F1 score was the greatest for EfficientNet-V1 (B1) with the original image size. EfficientNet-V1 (B1) and EfficientNet-V2 (B2) were used to develop an ensemble model, and the accuracy (0.8858) and F1 score (0.7361) were improved. The classification performance of the developed ensemble model for the 12 cell types was good, with an area under the receiver operating characteristic curve above 0.9, and F1 scores for myeloblasts and lymphoblasts of 0.8873 and 0.8006, respectively. Conclusions: The performance of the developed ensemble model for the 12 cell classifications was satisfactory, particularly for myeloblasts and lymphoblasts. We believe that the application of our model will benefit healthcare settings where the rapid and accurate diagnosis of AL is difficult.

Factors related to central nervous system involvement of primary vitreoretinal lymphoma.

PURPOSE: This single center retrospective study aimed to investigate the factors associated with central nervous system (CNS) involvement of primary vitreoretinal lymphoma (PVRL). METHODS: Clinical features of patients with PVRL (Group 1), those diagnosed with vitreoretinal lymphoma (VRL) after primary CNS lymphoma diagnosis (Group 2), and those concurrently diagnosed with CNS lymphoma and VRL (Group 3), were compared. The main outcomes included sex, age, types of treatment, survival, visual acuity, diagnostic methods, VRL recurrence, ocular manifestations, and interleukin levels in the aqueous humor. RESULTS: Groups 1, 2, and 3 included 66 eyes in 38 patients, 29 eyes in 18 patients, and 14 eyes in 8 patients, respectively. Group 3 had shorter overall survival (OS) than Groups 1 and 2 (P = 0.042 and P = 0.009, respectively). The three groups did not differ in progression-free survival (P = 0.060). The 5-year survival rates of Groups 1, 2, and 3 were 56.5%, 44.0%, and 25.0%, respectively (P = 0.001). Patients with CNS involvement in Group 1 exhibited VRL recurrence (P < 0.001), high interleukin-10 (P = 0.024), and sub-retinal pigment epithelium (RPE) infiltration (P = 0.009). Patients experiencing VRL recurrence in Group 1 tended to show CNS involvement (P < 0.001). CONCLUSION: Patients concurrently diagnosed with CNS lymphoma and VRL had a shorter OS and a lower 5-year survival rate. In patients with PVRL, the recurrence of VRL, high interleukin-10, and sub-RPE infiltration were associated with CNS involvement.

Analysis of the progression rate of idiopathic macular holes and the optimal cut-off for baseline minimum linear diameter and base diameter.

PURPOSE: To determine the cut-off points of minimum linear diameter (MLD) and base diameter (BD) at which the progression rate of idiopathic full-thickness macular holes (MHs) decreases before vitrectomy. STUDY DESIGN: A retrospective study. METHODS: We investigated the differences in MLD and BD between baseline and operation days in patients with stages 2, 3, and 4 MHs using optical coherence tomography (OCT). Each difference in OCT parameters was divided by the time interval to calculate the MH progression rates and the cut-off points of MLD and BD. RESULTS: Overall, 269 patients (282 eyes) were included. It took an average of 36.02 ± 24.69 (7-197) days from baseline to operation. MLD and BD progressed faster in stages 2 and 3 without posterior vitreous detachment (PVD) than in stage 4 with PVD (MLD: p < 0.001 and p = 0.007; BD: p < 0.001 and p = 0.019, respectively). Simple linear regression showed the relationship between baseline MLD and BD, and the progression rate; the progression rate decreased as baseline MLD (p = 0.004) and BD increased ( p < 0.001). For baseline MLD and BD, the cut-off points where the progression rate decreased were 306.0 and 470.0 µm, respectively. CONCLUSION: The group without PVD progressed faster than the group with PVD. Moreover, the progression rates were faster in MHs with MLD < 306.0 µm and BD < 470.0 µm. In these patients, vitrectomy without delay is expected to improve the visual prognosis.

Development of blood demand prediction model using artificial intelligence based on national public big data.

Objective: Modern healthcare systems face challenges related to the stable and sufficient blood supply of blood due to shortages. This study aimed to predict the monthly blood transfusion requirements in medical institutions using an artificial intelligence model based on national open big data related to transfusion. Methods: Data regarding blood types and components in Korea from January 2010 to December 2021 were obtained from the Health Insurance Review and Assessment Service and Statistics Korea. The data were collected from a single medical institution. Using the obtained information, predictive models were developed, including eXtreme Gradient Boosting (XGBoost), Light Gradient Boosting Machine (LGBM), and category boosting (CatBoost). An ensemble model was created using these three models. Results: The prediction performance of XGBoost, LGBM, and CatBoost demonstrated a mean absolute error ranging from 14.6657 for AB+ red blood cells (RBCs) to 84.0433 for A+ platelet concentrate (PC) and a root mean squared error ranging from 18.5374 for AB+ RBCs to 118.6245 for B+ PC. The error range was further improved by creating ensemble models, wherein the department requesting blood was the most influential parameter affecting transfusion prediction performance for different blood products and types. Except for the department, the features that affected the prediction performance varied for each product and blood type, including the number of RBC antibody screens, crossmatch, nationwide blood donations, and surgeries. Conclusion: Based on blood-related open big data, the developed blood-demand prediction algorithm can efficiently provide medical facilities with an appropriate volume of blood ahead of time.

Uncovering the colorectal cancer immunotherapeutic potential: Evening primrose (Oenothera biennis) root extract and its active compound oenothein B targeting the PD-1/PD-L1 blockade.

BACKGROUND: The emergence of immune checkpoint inhibitors, a novel class of immunotherapy drugs, represents a major breakthrough in cancer immunotherapy, substantially improving patient survival post-treatment. Blocking programmed death-ligand 1 (PD-L1) and programmed death protein-1 (PD-1) has demonstrated promising clinical results in various human cancer types. The US FDA has recently permitted only monoclonal antibody (mAb)-based PD-L1 or PD-1 blockers. Although these antibodies exhibit high antitumor efficacy, their size- and affinity-induced side effects limit their applicability. PURPOSE: As small-molecule-based PD-1/PD-L1 blockers capable of reducing the side effects of antibody therapies are needed, this study focuses on exploring natural ingredient-based small molecules that can target hPD-L1/PD-1 using herbal medicines and their components. METHODS: The antitumor potential of evening primrose (Oenothera biennis) root extract (EPRE), a globally utilized traditional herbal medicine, folk remedy, and functional food, was explored. A coculture system was established using human PD-L1-expressed murine MC38 cells (hPD-L1-MC38s) and CD8+ tumor-infiltrating T lymphocytes (CD8+ TILs) expressing humanized PD-1. The in vivo experiments utilized a colorectal cancer (CRC) C57BL/6 J mouse model bearing MC38 cells expressing humanized PD-L1 and PD-1 proteins. RESULTS: EPRE and its active compound oenothein B effectively hindered the molecular interaction between hPD-L1 and hPD-1. EPRE stimulated tumor-specific T lymphocytes of a hPD-L1/PD-1 CRC mice. This action resulted in the elevated infiltration of cytotoxic CD8+T lymphocytes and subsequent tumor growth reduction. Moreover, the combined therapy of oenothein B, a PD-1/PD-L1 blocker, and FOLFOX (5-fluorouracil plus oxaliplatin) cooperatively suppressed hPD-L1-MC38s growth in the ex vivo model through activated CD8+ TIL antitumor immune response. Oenothein B exhibited a high binding affinity for hPD-L1 and hPD-1. We believe that this study is the first to uncover the inhibitory effects of EPRE and its component, oenothein B, on PD-1/PD-L1 interactions. CONCLUSION: This study identified a promising small-molecule candidate from natural products that blocks the hPD-L1/PD-1 signaling pathway. These findings emphasize the potential of EPRE and oenothein B as effective anticancer drugs.

Outcome of Multiple Myeloma Patients With Hepatitis B Surface Antigen: Korean Multiple Myeloma Working Party 2103 Study.

BACKGROUND: Hepatitis B virus reactivation (HBVr) is a well-known complication of systemic chemotherapy for particularly hematologic malignancies in HBV carriers. We performed a multicenter retrospective study to investigate the incidence and risk factors of HBVr in patients with hepatitis B surface antigen (HBsAg)-positive multiple myeloma (MM). METHODS: We included 123 patients with HBsAg-positive MM who had received systemic therapy. The primary objective of the study was to evaluate the incidence of HBVr in patients with HBsAg-positive MM. RESULTS: The median age was 59 years, and 72 patients were male. With a median follow-up duration of 41.4 months, there were 43 instances of HBVr in 35 patients (28.5%): 29 treatment-related HBVr occurred during 424 treatments. Treatments containing antiviral prophylaxis were associated with a significantly lower incidence of HBVr compared to those without (14.4% vs. 1.9%, P < 0.001). Moreover, treatment with cyclophosphamide (P = 0.002) and doxorubicin (P = 0.053) were risk factors for HBVr; stem cell transplantation was not associated with HBVr. There was no significant difference in overall survival between patients with and without HBVr (P = 0.753) and myeloma progression was the major cause of death. CONCLUSION: Considering the low incidence of HBVr in patients who had received antiviral prophylaxis, HBsAg-positivity should not impede patients from receiving optimal antimyeloma treatment or participating in clinical trials.

Alteration of perivascular reflectivity on optical coherence tomography of branched retinal vein obstruction.

This study aimed to evaluate perivascular reflectivity in patients with branched retinal vascular obstruction (BRVO) using en-face optical coherence tomography (OCT). The study retrospectively analyzed 45 patients with recurrent BRVO, 30 with indolent BRVO, and 45 age- and sex-matched controls. Using a 3.0 × 3.0-mm deep capillary plexus slab on macular scans, OCT angiography (OCTA) and structural en-face OCT scans were divided into four quadrants. Obstructive quadrants of OCTA scans were binarized using a threshold value of mean + 2 standard deviation. The selected area of high signal strength (HSS) was applied to the structural en-face OCT scans, and the corrected mean perivascular reflectivity was calculated as the mean reflectivity on the HSS area/overall en-face OCT mean reflectivity. The same procedure was performed in the quadrants of the matched controls. Regression analysis was conducted on several factors possibly associated with corrected perivascular reflectivity. The perivascular reflectivity in the obstructive BRVO quadrant was significantly higher than in the indolent BRVO and control quadrants (P = 0.009, P = 0.003). Both univariate and multivariate regression analyses showed a significant correlation between the average number of intravitreal injections (anti-vascular endothelial growth factor or dexamethasone implant) per year and refractive errors and image binarization threshold and perivascular reflectivity (P = 0.011, 0.013, < 0.001/univariate; 0.007, 0.041, 0.005/multivariate, respectively). En-face OCT scans of the deep capillary plexus slab revealed higher perivascular reflectivity in recurrent BRVO eyes than in indolent BRVO and control eyes. The results also indicate a remarkable correlation between perivascular reflectivity and the average number of intravitreal injections, suggesting a link to recurrence rates.

The structure of AcrIC9 revealing the putative inhibitory mechanism of AcrIC9 against the type IC CRISPR-Cas system.

CRISPR-Cas systems are known to be part of the bacterial adaptive immune system that provides resistance against intruders such as viruses, phages and other mobile genetic elements. To combat this bacterial defense mechanism, phages encode inhibitors called Acrs (anti-CRISPR proteins) that can suppress them. AcrIC9 is the most recently identified member of the AcrIC family that inhibits the type IC CRISPR-Cas system. Here, the crystal structure of AcrIC9 from Rhodobacter capsulatus is reported, which comprises a novel fold made of three central antiparallel ß-strands surrounded by three α-helixes, a structure that has not been detected before. It is also shown that AcrIC9 can form a dimer via disulfide bonds generated by the Cys69 residue. Finally, it is revealed that AcrIC9 directly binds to the type IC cascade. Analysis and comparison of its structure with structural homologs indicate that AcrIC9 belongs to DNA-mimic Acrs that directly bind to the cascade complex and hinder the target DNA from binding to the cascade.

Elevated interleukin-10 levels in patients with ocular toxoplasmosis.

In elderly patients, ocular toxoplasmosis is one of the most common etiologies of uveitis, which should be differentially diagnosed from ocular lymphoma, another common pathology of uveitis in older adults. The high level of interleukin (IL)-10 and an IL-10/IL-6 ratio higher than 1 (>1.0) are helpful parameters to diagnose ocular lymphoma. In this study, we used aqueous humor samples to detect 4 cases of ocular toxoplasmosis in patients with high levels of IL-10 and an IL-10/IL-6 ratio higher than 1. Our results show that ocular toxoplasmosis may be associated with increased cytokine levels in aqueous humor.

Nectin-4 as a Predictive Marker for Poor Prognosis of Endometrial Cancer with Mismatch Repair Impairment.

The adhesion molecule Nectin-4 is a new potential therapeutic target for different types of cancer; however, little is known about its diagnosis significance in endometrial cancer (EC). We found that Nectin-4 expression was significantly higher in EC tissues than in nonadjacent normal tissue. The area under the receiver operating characteristic curve value of 0.922 indicated good diagnostic accuracy for Nectin-4 expression in EC. Furthermore, Nectin-4 expression was associated with DNA mismatch repair (MMR) protein deficiency. Notably, the high Nectin-4 expression group of patients with MSH2/6-deficient EC had shorter progression-free survival than that of the low Nectin-4 expression group. The number of lymphovascular space invasion-positive patients in groups with MMR deficiency and high Nectin-4 expression was also increased compared with that in the low Nectin-4 expression group. Bioinformatics analysis revealed that alteration in Nectin-4 and MMR genes is associated with Nectin-4 expression in EC. To the best of our knowledge, this is the first study to show that Nectin-4 expression may be a potential biomarker for EC diagnosis and that high Nectin-4 expression in MMR-deficient patients with EC can predict short progression-free survival, thus providing clues to identify patients for adjuvant therapy.