Intestinal CXCR6+ ILC3s migrate to the kidney and exacerbate renal fibrosis via IL-23 receptor signaling enhanced by PD-1 expression.

Group 3 innate lymphoid cells (ILC3s) regulate inflammation and tissue repair at mucosal sites, but whether these functions pertain to other tissues-like the kidneys-remains unclear. Here, we observed that renal fibrosis in humans was associated with increased ILC3s in the kidneys and blood. In mice, we showed that CXCR6+ ILC3s rapidly migrated from the intestinal mucosa and accumulated in the kidney via CXCL16 released from the injured tubules. Within the fibrotic kidney, ILC3s increased the expression of programmed cell death-1 (PD-1) and subsequent IL-17A production to directly activate myofibroblasts and fibrotic niche formation. ILC3 expression of PD-1 inhibited IL-23R endocytosis and consequently amplified the JAK2/STAT3/RORγt/IL-17A pathway that was essential for the pro-fibrogenic effect of ILC3s. Thus, we reveal a hitherto unrecognized migration pathway of ILC3s from the intestine to the kidney and the PD-1-dependent function of ILC3s in promoting renal fibrosis.

Intestinal epithelial dopamine receptor signaling drives sex-specific disease exacerbation in a mouse model of multiple sclerosis.

Although the gut microbiota can influence central nervous system (CNS) autoimmune diseases, the contribution of the intestinal epithelium to CNS autoimmunity is less clear. Here, we showed that intestinal epithelial dopamine D2 receptors (IEC DRD2) promoted sex-specific disease progression in an animal model of multiple sclerosis. Female mice lacking Drd2 selectively in intestinal epithelial cells showed a blunted inflammatory response in the CNS and reduced disease progression. In contrast, overexpression or activation of IEC DRD2 by phenylethylamine administration exacerbated disease severity. This was accompanied by altered lysozyme expression and gut microbiota composition, including reduced abundance of Lactobacillus species. Furthermore, treatment with N2-acetyl-L-lysine, a metabolite derived from Lactobacillus, suppressed microglial activation and neurodegeneration. Taken together, our study indicates that IEC DRD2 hyperactivity impacts gut microbial abundances and increases susceptibility to CNS autoimmune diseases in a female-biased manner, opening up future avenues for sex-specific interventions of CNS autoimmune diseases.

Geranylgeranyl isoprenoids and hepatic Rap1a regulate basal and statin-induced expression of PCSK9.

LDL-C lowering is the main goal of atherosclerotic cardiovascular disease prevention, and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition is now a validated therapeutic strategy that lowers serum LDL-C and reduces coronary events. Ironically, the most widely used medicine to lower cholesterol, statins, has been shown to increase circulating PCSK9 levels, which limits their efficacy. Here, we show that geranylgeranyl isoprenoids and hepatic Rap1a regulate both basal and statin-induced expression of PCSK9 and contribute to LDL-C homeostasis. Rap1a prenylation and activity is inhibited upon statin treatment, and statin-mediated PCSK9 induction is dependent on geranylgeranyl synthesis and hepatic Rap1a. Accordingly, treatment of mice with a small-molecule activator of Rap1a lowered PCSK9 protein and plasma cholesterol and inhibited statin-mediated PCSK9 induction in hepatocytes. The mechanism involves inhibition of the downstream RhoA-ROCK pathway and regulation of PCSK9 at the post-transcriptional level. These data further identify Rap1a as a novel regulator of PCSK9 protein and show that blocking Rap1a prenylation through lowering geranylgeranyl levels contributes to statin-mediated induction of PCSK9.

Differential Protein Expression in Set5p-Mediated Acetic Acid Stress Response and Novel Targets for Engineering Yeast Stress Tolerance.

Acetic acid is a prevalent inhibitor in lignocellulosic hydrolysate, which represses microbial growth and bioproduction. Histone modification and chromatin remodeling have been revealed to be critical for regulating eukaryotic metabolism. However, related studies in chronic acetic acid stress responses remain unclear. Our previous studies revealed that overexpression of the histone H4 methyltransferase Set5p enhanced acetic acid stress tolerance of the budding yeast Saccharomyces cerevisiae. In this study, we examined the role of Set5p in acetic acid stress by analyzing global protein expression. Significant activation of intracellular protein expression under the stress was discovered, and the functions of the differential proteins were mainly involved in chromatin modification, signal transduction, and carbohydrate metabolism. Notably, a substantial increase of Set5p expression was observed in response to acetic acid stress. Functional studies demonstrated that the restriction of the telomere capping protein Rtc3p, as well as Ies3p and Taf14p, which are related to chromatin regulation, was critical for yeast stress response. This study enriches the understanding of the epigenetic regulatory mechanisms underlying yeast stress response mediated by histone-modifying enzymes. The results also benefit the development of robust yeast strains for lignocellulosic bioconversion.

The glycolytic enzyme PFKFB3 drives kidney fibrosis through promoting histone lactylation-mediated NF-κB family activation.

Persistently elevated glycolysis in kidney has been demonstrated to promote chronic kidney disease (CKD). However, the underlying mechanism remains largely unclear. Here, we observed that 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3), a key glycolytic enzyme, was remarkably induced in kidney proximal tubular cells (PTCs) following ischemia-reperfusion injury (IRI) in mice, as well as in multiple etiologies of patients with CKD. PFKFB3 expression was positively correlated with the severity of kidney fibrosis. Moreover, patients with CKD and mice exhibited increased urinary lactate/creatine levels and kidney lactate, respectively. PTC-specific deletion of PFKFB3 significantly reduced kidney lactate levels, mitigated inflammation and fibrosis, and preserved kidney function in the IRI mouse model. Similar protective effects were observed in mice with heterozygous deficiency of PFKFB3 or those treated with a PFKFB3 inhibitor. Mechanistically, lactate derived from PFKFB3-mediated tubular glycolytic reprogramming markedly enhanced histone lactylation, particularly H4K12la, which was enriched at the promoter of NF-κB signaling genes like Ikbkb, Rela, and Relb, activating their transcription and facilitating the inflammatory response. Further, PTC-specific deletion of PFKFB3 inhibited the activation of IKKß, I κ B α, and p65 in the IRI kidneys. Moreover, increased H4K12la levels were positively correlated with kidney inflammation and fibrosis in patients with CKD. These findings suggest that tubular PFKFB3 may play a dual role in enhancing NF-κB signaling by promoting both H4K12la-mediated gene transcription and its activation. Thus, targeting the PFKFB3-mediated NF-κB signaling pathway in kidney tubular cells could be a novel strategy for CKD therapy.

Survival trends among patients with metastatic non-small cell lung cancer before and after the approval of immunotherapy in the United States: A Surveillance, Epidemiology, and End Results database-based study.

BACKGROUND: In 2015, the US Food and Drug Administration approved nivolumab as the first immunotherapy for patients with advanced non-small cell lung cancer (NSCLC). However, population-based survival benefit studies after the introduction of immunotherapy in lung cancer are lacking. This study examined overall survival (OS) and cancer-specific survival in patients with NSCLC in the pre immunotherapy and immunotherapy eras. METHODS: This study used the Surveillance, Epidemiology, and End Results database, which spanned 17 registries from 2000 to 2020. Two cohorts were delineated: preimmunotherapy (2010-2014) and immunotherapy (2015-2020), which coincided with nivolumab's approval. RESULTS: This study included 191,802 patients, 90,807 in the preimmunotherapy era and 100,995 in the immunotherapy era. OS was significantly higher in the immunotherapy era, as shown by Kaplan-Meier curves (1-year OS, 40.1% vs. 33.5%; 3-year OS, 17.8% vs. 11.7%; 5-year OS, 10.7% vs. 6.8%; median OS, 8 vs. 7 months; p < .001 by log-rank test). Similarly, cancer-specific survival improved in the immunotherapy era (1-year survival, 44.0% vs. 36.8%; 3-year survival, 21.7% vs. 14.4%; 5-year survival, 14.3% vs. 9.0%; median OS, 10 vs. 8 months; p < .001 by log-rank test). Survival rates were significantly better in the immunotherapy era, as confirmed by multivariate analysis with a Cox proportional hazards model after adjusting for age, sex, race, income, and geographical area (adjusted hazard ratio, 0.830; 95% CI, 0.821-0.840; p < .001). CONCLUSIONS: In summary, the survival rate of patients with metastatic NSCLC has improved since the introduction of immunotherapy.

Incidence, Correlates, and Prognostic Significance of Mixed Response in Advanced Non-small Cell Lung Cancer.

BACKGROUND: Mixed response (MR), a scenario featuring discordant tumor changes, has been reported primarily with targeted therapies or immunotherapy. We determined the incidence and prognostic significance of MR in advanced non-small cell lung cancer (NSCLC) treated with cytotoxic chemotherapy. PATIENTS AND METHODS: We analyzed patient-level data from ECOG-ACRIN E5508 (carboplatin-paclitaxel + bevacizumab induction followed by randomization to maintenance therapy regimens). For patients with at least 2 target lesions and available measurements after cycle 2, we characterized response as homogeneous response (HR, similar behavior of all lesions), MR (similar behavior but >30% difference in magnitude of best and least responding lesions), or true mixed response (TMR, best and least responding lesions showing different behavior: ≥10% growth versus ≥10% shrinkage). We compared category characteristics using Mann-Whitney U and Chi-square tests, and overall survival (OS) using log-rank test and Cox models. RESULTS: Among 965 evaluable patients, HR occurred in 609 patients (63%), MR in 208 (22%), and TMR in 148 (15%). Median OS was 13.6 months for HR, 12.0 months for MR, and 7.6 months for TMR (P < .001). Compared to HR, TMR had inferior OS among stable disease cases (HR 1.62; 95% CI, 1.23-2.12; P < .001) and a trend toward inferior OS among progressive disease cases (HR 1.39; 95% CI, 0.83-2.33; P = .2). In multivariate analysis, TMR was associated with worse OS (HR 1.48; 95% CI, 1.22-1.79; P < .001). CONCLUSION: True mixed response occurs in a substantial minority of lung cancer cases treated with chemotherapy and independently confers poor prognosis.

Spatially Confined Nanoreactors Designed for Biological Applications.

The applications of nanoreactors in biology are becoming increasingly significant and prominent. Specifically, nanoreactors with spatially confined, due to their exquisite design that effectively limits the spatial range of biomolecules, attracted widespread attention. The main advantage of this structure is designed to improve reaction selectivity and efficiency by accumulating reactants and catalysts within the chambers, thus increasing the frequency of collisions between reactants. Herein, the recent progress in the synthesis of spatially confined nanoreactors and their biological applications is summarized, covering various kinds of nanoreactors, including porous inorganic materials, porous crystalline materials with organic components and self-assembled polymers to construct nanoreactors. These design principles underscore how precise reaction control could be achieved by adjusting the structure and composition of the nanoreactors to create spatial confined. Furthermore, various applications of spatially confined nanoreactors are demonstrated in the biological fields, such as biocatalysis, molecular detection, drug delivery, and cancer therapy. These applications showcase the potential prospects of spatially confined nanoreactors, offering robust guidance for future research and innovation.

In-Induced Electronic Structure Modulations of Bi─O Active Sites for Selective Carbon Dioxide Electroreduction to Liquid Fuel in Strong Acid.

The formation of carbonate in neutral/alkaline solutions leads to carbonate crossover, severely reducing carbon dioxide (CO2 ) single pass conversion efficiency (SPCE). Thus, CO2 electrolysis is a prospective route to achieve high CO2 utilization under acidic environment. Bimetallic Bi-based catalysts obtained utilizing metal doping strategies exhibit enhanced CO2 -to-formic acid (HCOOH) selectivity in alkaline/neutral media. However, achieving high HCOOH selectivity remains challenging in acidic media. To this end, Indium (In) doped Bi2O2CO3 via hydrothermal method is prepared for in-situ electroreduction to In-Bi/BiOx nanosheets for acidic CO2 reduction reaction (CO2RR). In doping strategy regulates the electronic structure of Bi, promoting the fast derivatization of Bi2O2CO3 into Bi-O active sites to enhance CO2RR catalytic activity. The optimized Bi2 O2 CO3 -derived catalyst achieves the maximum HCOOH faradaic efficiency (FE) of 96% at 200 mA cm-2 . The SPCE for HCOOH production in acid is up to 36.6%, 2.2-fold higher than the best reported catalysts in alkaline environment. Furthermore, in situ Raman and X-ray photoelectron spectroscopy demonstrate that In-induced electronic structure modulation promotes a rapid structural evolution from nanobulks to Bi/BiOx nanosheets with more active species under acidic CO2 RR, which is a major factor in performance improvement.

Methyl jasmonate differentially and tissue-specifically regulated the expression of arginine catabolism-related genes and proteins in Agaricus bisporus mushrooms during storage.

Methyl jasmonate (MeJA)-regulated postharvest quality retention of Agaricus bisporus fruiting bodies is associated with arginine catabolism. However, the mechanism of MeJA-regulated arginine catabolism in edible mushrooms is still unclear. This study aimed to investigate the regulatory modes of MeJA on the expression of arginine catabolism-related genes and proteins in intact and different tissues of A. bisporus mushrooms during storage. Results showed that exogenous MeJA treatment activated endogenous JA biosynthesis in A. bisporus mushrooms, and differentially and tissue-specifically regulated the expression of arginine catabolism-related genes (AbARG, AbODC, AbSPE-SDH, AbSPDS, AbSAMDC, and AbASL) and proteins (AbARG, AbSPE-SDH, AbASL, and AbASS). MeJA caused no significant change in AbASS expression but resulted in a dramatic increase in AbASS protein level. Neither the expression of the AbSAMS gene nor the AbSAMS protein was conspicuously altered upon MeJA treatment. Additionally, MeJA reduced the contents of arginine and ornithine and induced the accumulation of free putrescine and spermidine, which was closely correlated with MeJA-regulated arginine catabolism-related genes and proteins. Hence, the results suggested that the differential and tissue-specific regulation of arginine catabolism-related genes and proteins by MeJA contributed to their selective involvement in the postharvest continuing development and quality retention of button mushrooms.

Identification of a novel LFNG variant in a Chinese fetus with spondylocostal dysostosis and a systematic review.

Spondylocostal dysostosis (SCDO) encompasses a group of skeletal disorders characterized by multiple segmentation defects in the vertebrae and ribs. SCDO has a complex genetic etiology. This study aimed to analyze and identify pathogenic variants in a fetus with SCDO. Copy number variant sequencing and whole exome sequencing were performed on a Chinese fetus with SCDO, followed by bioinformatics analyses, in vitro functional assays and a systematic review on the reported SCDO cases with LFNG pathogenic variants. Ultrasound examinations in utero exhibited that the fetus had vertebral malformation, scoliosis and tethered cord, but rib malformation was not evident. We found a novel homozygous variant (c.1078 C > T, p.R360C) within the last exon of LFNG. The variant was predicted to cause loss of function of LFNG by in silico prediction tools, which was confirmed by an in vitro assay of LFNG enzyme activity. The systematic review listed a total of 20 variants of LFNG in SCDO. The mutational spectrum spans across all exons of LFNG except the last one. This study reported the first Chinese case of LFNG-related SCDO, revealing the prenatal phenotypes and expanding the mutational spectrum of the disorder.

In-situ Construction of Poly(tetraisopentyl acrylate) based Gel Polymer Electrolytes with Lix La2-x TiO3 for High Energy Density Lithium-Metal Batteries.

As promising alternatives to liquid electrolytes, polymer electrolytes attract much research interest recently, but their widespread use is limited by the low ionic conductivity. In this study, we use electrostatic spinning to introduce particles of an ionic conductor into polyacrylonitrile (PAN) fibers to prepare a porous membrane as the host of gel polymer electrolytes (GPEs). The relevant in-situ produced GPE performs a high ionic conductivity of 6.0×10-3  S cm-1 , and a high lithium transfer number (tLi + ) of 0.85 at 30 °C, respectively. A symmetrical Li cell with this GPE can cycle stably for 550 h at a current density of 0.5 mA cm-2 . While the capacity retention of the NCM|GPE|Li cell is 79.84 % after 500 cycles at 2 C. Even with an increased cut-off voltage of 4.5 V, the 1st coulomb efficiency reaches 91.58 % with a specific discharge capacity of 213.4 mAh g-1 . This study provides a viable route for the practical application of high energy density lithium metal batteries.

Modified Radiation Lobectomy Strategy of Radioembolization for Right-Sided Unresectable Primary Liver Tumors.

PURPOSE: To assess the safety and effectiveness of using modified radiation lobectomy (mRL) to treat primary hepatic tumors located in the right hepatic lobe (Segments V-VIII) and to determine future liver remnant (FLR) hypertrophy. MATERIALS AND METHODS: A retrospective review was performed at a single institution to include 19 consecutive patients (7 females, 12 males) who underwent single-session mRL for right-sided primary hepatic tumors: 15 received segmentectomy plus lobectomy (segmental dose of >190 Gy and lobar dose of >80 Gy); 4 were treated with the double-segmental approach (dominant segments of >190 Gy and nondominant segments of >80 Gy). Treated tumors included 13 hepatocellular carcinoma (HCC), 4 cholangiocarcinoma (CCA), and 2 mixed-type HCC-CCA with a median dominant tumor size of 5.3 cm (interquartile range [IQR], 3.7-7.3 cm). FLR of the left hepatic lobe was measured at baseline, T1 (4-8 weeks), T2 (2-4 months), T3 (4-6 months), and T4 (9-12 months). RESULTS: Objective tumor response and tumor control were achieved in 17 of the 19 (89.5%) and 18 of the 19 (94.7%) patients, respectively. FLR hypertrophy was observed at T1 (median, 47.8%; P = .025), T2 (median, 48.4%; P = .012), T3 (median, 50.4%; P = .015), and T4 (median, 59.1%; P < .001). Patients without cirrhosis demonstrated greater hypertrophy by 6 months (median, 55.8% vs 47.2%; P = .031). One patient developed a Grade 3 adverse event (ascites requiring paracentesis) at 1-month follow-up. Grade ≥2 serum toxicities were associated with worse baseline Child-Pugh Score, serum albumin, and total bilirubin (P < .05). Among 7 patients who underwent neoadjuvant mRL, 2 underwent resection and 1 received liver transplant. CONCLUSIONS: mRL appears safe and effective for treatment of right-sided primary hepatic tumors with the benefit of promoting FLR hypertrophy.

A silver-mediated radical process of ß-keto sulfones for the synthesis of 2,3-diacyl furans.

A facile and efficient method for constructing 2,3-diacyl trisubstituted furans via a silver-mediated radical process of ß-keto sulfones is developed. The reaction mechanism has been carefully investigated, revealing that the transformation proceeds through a radical pathway, leading to moderate to good yields of desired products.

A multi-dimensional photodetector based on an α-MoO3 grating and graphene.

Integration of multi-dimensional optical information enhances the recognition and anti-interference capabilities of the detection system, allowing for better adaptation to complex environments. Therefore, this technology represents a crucial developmental pathway for the future of infrared optical detectors. In this study, a dual-band polarization photodetector based on a two-dimensional α-MoO3 grating structure is proposed. The structure utilizes the special dispersion property of the α-MoO3 material to excite the localized plasmon resonance, which generates narrowband high absorption peaks with Q-factors as high as 110.24 and 92.65, with peaks close to 1 under TM and TE polarized waves, respectively. The direct measurement of multi-dimensional optical information including intensity, spectrum and polarization states is realized. By adjusting the structural parameters, polarization-dependent dual-band detection can be achieved. Meanwhile, the introduction of graphene material realizes the electronically tunable function of the device. This study provides unexplored strategies for realizing more efficient, flexible and versatile dual-band polarization wave detection.

A systematic review and meta-analysis of the efficacy of ketamine and esketamine on suicidal ideation in treatment-resistant depression.

PURPOSE: To systematically assess the evidence of efficacy and safety of the use of ketamine and esketamine for patients with treatment-resistant depression (TRD) with suicidal ideation (SI). METHODS: We independently searched for clinical trials from inception to January 2023 using electronic databases, e.g., PubMed and EMBASE. A systematic review and meta-analysis were performed to assess SI scores of depression rating scales, which were regarded as the outcomes. RESULTS: A total of five independent double-blind, placebo controlled randomized clinical trials (RCTs) are eligible for inclusion. Four of the studies used ketamine as an intervention and one used esketamine as an intervention. Three hundred ninety-one patients with TRD were included (the intervention group with ketamine or esketamine is 246, and the control group is 145). No statistically significant interaction between the subscales of suicide ideation (SMD = - 0.66, 95% CI (- 1.61, 0.29); Z = 1.36, P = 0.17) and antidepressant effects (SMD = - 0.99, 95% CI (- 2.33, 0.34); Z = 1.46, P = 0.15) based on the results of ketamine and esketamine, compared with placebo groups. CONCLUSION: This meta-analysis suggested that esketamine and ketamine have failed to reduce suicidal ideation in patients with TRD. Further studies are desirable to confirm the effects of ketamine and esketamine in TRD patients.

The role of cellular senescence in neurodegenerative diseases.

Increasing evidence has revealed that cellular senescence drives NDs, including Alzheimer's disease (AD) and Parkinson's disease. Different senescent cell populations secrete senescence-associated secretory phenotypes (SASP), including matrix metalloproteinase-3, interleukin (IL)-1α, IL-6, and IL-8, which can harm adjacent microglia. Moreover, these cells possess high expression levels of senescence hallmarks (p16 and p21) and elevated senescence-associated ß-galactosidase activity in in vitro and in vivo ND models. These senescence phenotypes contribute to the deposition of ß-amyloid and tau-protein tangles. Selective clearance of senescent cells and SASP regulation by inhibiting p38/mitogen-activated protein kinase and nuclear factor kappa B signaling attenuate ß-amyloid load and prevent tau-protein tangle deposition, thereby improving cognitive performance in AD mouse models. In addition, telomere shortening, a cellular senescence biomarker, is associated with increased ND risks. Telomere dysfunction causes cellular senescence, stimulating IL-6, tumor necrosis factor-α, and IL-1ß secretions. The forced expression of telomerase activators prevents cellular senescence, yielding considerable neuroprotective effects. This review elucidates the mechanism of cellular senescence in ND pathogenesis, suggesting strategies to eliminate or restore senescent cells to a normal phenotype for treating such diseases.

UFMylation inhibits the proinflammatory capacity of interferon-γ-activated macrophages.

Macrophages activated with interferon-γ (IFN-γ) in combination with other proinflammatory stimuli, such as lipopolysaccharide or tumor necrosis factor-α (TNF-α), respond with transcriptional and cellular changes that enhance clearance of intracellular pathogens at the risk of damaging tissues. IFN-γ effects must therefore be carefully balanced with inhibitory mechanisms to prevent immunopathology. We performed a genome-wide CRISPR knockout screen in a macrophage cell line to identify negative regulators of IFN-γ responses. We discovered an unexpected role of the ubiquitin-fold modifier (Ufm1) conjugation system (herein UFMylation) in inhibiting responses to IFN-γ and lipopolysaccharide. Enhanced IFN-γ activation in UFMylation-deficient cells resulted in increased transcriptional responses to IFN-γ in a manner dependent on endoplasmic reticulum stress responses involving Ern1 and Xbp1. Furthermore, UFMylation in myeloid cells is required for resistance to influenza infection in mice, indicating that this pathway modulates in vivo responses to infection. These findings provide a genetic roadmap for the regulation of responses to a key mediator of cellular immunity and identify a molecular link between the UFMylation pathway and immune responses.

A Novel Single-Sample Retinal Vessel Segmentation Method Based on Grey Relational Analysis.

Accurate segmentation of retinal vessels is of great significance for computer-aided diagnosis and treatment of many diseases. Due to the limited number of retinal vessel samples and the scarcity of labeled samples, and since grey theory excels in handling problems of "few data, poor information", this paper proposes a novel grey relational-based method for retinal vessel segmentation. Firstly, a noise-adaptive discrimination filtering algorithm based on grey relational analysis (NADF-GRA) is designed to enhance the image. Secondly, a threshold segmentation model based on grey relational analysis (TS-GRA) is designed to segment the enhanced vessel image. Finally, a post-processing stage involving hole filling and removal of isolated pixels is applied to obtain the final segmentation output. The performance of the proposed method is evaluated using multiple different measurement metrics on publicly available digital retinal DRIVE, STARE and HRF datasets. Experimental analysis showed that the average accuracy and specificity on the DRIVE dataset were 96.03% and 98.51%. The mean accuracy and specificity on the STARE dataset were 95.46% and 97.85%. Precision, F1-score, and Jaccard index on the HRF dataset all demonstrated high-performance levels. The method proposed in this paper is superior to the current mainstream methods.

The race to develop oral SERDs and other novel estrogen receptor inhibitors: recent clinical trial results and impact on treatment options.

Hormonal therapy plays a vital part in the treatment of estrogen receptor-positive (ER +) breast cancer. ER can be activated in a ligand-dependent and independent manner. Currently available ER-targeting agents include selective estrogen receptor modulators (SERMs), selective estrogen receptor degraders (SERDs), and aromatase inhibitors (AIs). Estrogen receptor mutation (ESR1 mutation) is one of the common mechanisms by which breast cancer becomes resistant to additional therapies from SERMs or AIs. These tumors remain sensitive to SERDs such as fulvestrant. Fulvestrant is limited in clinical utilization by its intramuscular formulation and once-monthly injection in large volumes. Oral SERDs are being rapidly developed to replace fulvestrant with the potential of higher efficacy and lower toxicities. Elacestrant is the first oral SERD that went through a randomized phase III trial showing increased efficacy, especially in tumors bearing ESR1 mutation, and good tolerability. Two other oral SERDs recently failed to achieve the primary endpoints of longer progression-free survival (PFS). They targeted tumors previously treated with several lines of prior therapies untested for ESR1 mutation. Initial clinical trial data demonstrated that tumors without the ESR1 mutation are less likely to benefit from the SERDs and may still respond to SERMs or AIs, including tumors previously exposed to hormonal therapy. Testing for ESR1 mutation in ongoing clinical trials and in hormonal therapy for breast cancer is highly recommended. Novel protein degradation technologies such as proteolysis-targeting chimera (PROTACS), molecular glue degrader (MGD), and lysosome-targeting chimeras (LYTACS) may result in more efficient ER degradation, while ribonuclease-targeting chimeras (RIBOTAC) and small interfering RNA (siRNA) may inhibit the production of ER protein.