Triple-negative breast cancer (TNBC) is an aggressive cancer subtype lacking targeted therapies and is characterized by highrecurrence rates and poor prognosis. Recent advances in targeting DNA damage response (DDR) pathways using poly (ADP‒ri-bose) polymerase (PARP) inhibitors offer promising therapeutic strategies, especially for TNBC patients with BRCA1/2 mutations.This study reports the development and characterization of ART-446, a novel and selective CHK2 inhibitor. ART-446 showed potent activity against TNBC, regardless of BRCA deficiency, and it also reversed PARP inhibitor resistance. ART-446 potentlyinhibited CHK2 (IC50 : 9.06 nM) with high selectivity over other kinases; it synergized with the PARP inhibitor olaparib, enhancingDNA damage, inducing G2/M cell cycle arrest, and promoting apoptosis in both BRCA-mutant and wild-type TNBC cells. Mechanistic analyses revealed that ART-446 sensitized BRCA mutant and WT cells to PARP inhibitors by impairing DNA repair and increasing the accumulation of DNA damage. Importantly, ART-446 disrupted both homologous recombination and nonhomologous end-joining repair pathways, addressing a key limitation of PARP inhibitor monotherapy—resistance in BRCA-proficient cancers.In vivo, the combination of ART-446 and olaparib significantly reduced tumor growth in TNBC xenograft models without noticeable toxicity. The combined treatment increased DNA damage signaling, as evidenced by elevated γH2AX levels, and enhanced the sensitivity of BRCA2-deficient cells to ART-446. These findings underscore the potential of ART-446 to exploit DNA repair deficiencies and overcome resistance mechanisms associated with PARP inhibitors. By addressing the limitations of current treatments and expanding the utility of PARP inhibitors, ART-446 represents a promising candidate for DDR-targeted therapies, offering a novel approach to improve the outcomes of patients with TNBC.

Triple-negative breast cancer (TNBC) is an aggressive cancer subtype lacking targeted therapies and is characterized by highrecurrence rates and poor prognosis. Recent advances in targeting DNA damage response (DDR) pathways using poly (ADP‒ri-bose) polymerase (PARP) inhibitors offer promising therapeutic strategies, especially for TNBC patients with BRCA1/2 mutations.This study reports the development and characterization of ART-446, a novel and selective CHK2 inhibitor. ART-446 showed potent activity against TNBC, regardless of BRCA deficiency, and it also reversed PARP inhibitor resistance. ART-446 potentlyinhibited CHK2 (IC50 : 9.06 nM) with high selectivity over other kinases; it synergized with the PARP inhibitor olaparib, enhancingDNA damage, inducing G2/M cell cycle arrest, and promoting apoptosis in both BRCA-mutant and wild-type TNBC cells. Mechanistic analyses revealed that ART-446 sensitized BRCA mutant and WT cells to PARP inhibitors by impairing DNA repair and increasing the accumulation of DNA damage. Importantly, ART-446 disrupted both homologous recombination and nonhomologous end-joining repair pathways, addressing a key limitation of PARP inhibitor monotherapy—resistance in BRCA-proficient cancers.In vivo, the combination of ART-446 and olaparib significantly reduced tumor growth in TNBC xenograft models without noticeable toxicity. The combined treatment increased DNA damage signaling, as evidenced by elevated γH2AX levels, and enhanced the sensitivity of BRCA2-deficient cells to ART-446. These findings underscore the potential of ART-446 to exploit DNA repair deficiencies and overcome resistance mechanisms associated with PARP inhibitors. By addressing the limitations of current treatments and expanding the utility of PARP inhibitors, ART-446 represents a promising candidate for DDR-targeted therapies, offering a novel approach to improve the outcomes of patients with TNBC.

Triple-negative breast cancer (TNBC) is an aggressive cancer subtype lacking targeted therapies and is characterized by highrecurrence rates and poor prognosis. Recent advances in targeting DNA damage response (DDR) pathways using poly (ADP‒ri-bose) polymerase (PARP) inhibitors offer promising therapeutic strategies, especially for TNBC patients with BRCA1/2 mutations.This study reports the development and characterization of ART-446, a novel and selective CHK2 inhibitor. ART-446 showed potent activity against TNBC, regardless of BRCA deficiency, and it also reversed PARP inhibitor resistance. ART-446 potentlyinhibited CHK2 (IC50 : 9.06 nM) with high selectivity over other kinases; it synergized with the PARP inhibitor olaparib, enhancingDNA damage, inducing G2/M cell cycle arrest, and promoting apoptosis in both BRCA-mutant and wild-type TNBC cells. Mechanistic analyses revealed that ART-446 sensitized BRCA mutant and WT cells to PARP inhibitors by impairing DNA repair and increasing the accumulation of DNA damage. Importantly, ART-446 disrupted both homologous recombination and nonhomologous end-joining repair pathways, addressing a key limitation of PARP inhibitor monotherapy—resistance in BRCA-proficient cancers.In vivo, the combination of ART-446 and olaparib significantly reduced tumor growth in TNBC xenograft models without noticeable toxicity. The combined treatment increased DNA damage signaling, as evidenced by elevated γH2AX levels, and enhanced the sensitivity of BRCA2-deficient cells to ART-446. These findings underscore the potential of ART-446 to exploit DNA repair deficiencies and overcome resistance mechanisms associated with PARP inhibitors. By addressing the limitations of current treatments and expanding the utility of PARP inhibitors, ART-446 represents a promising candidate for DDR-targeted therapies, offering a novel approach to improve the outcomes of patients with TNBC.

Background: and Purpose The influence of imaging features of brain frailty on outcomes were investigated in acute ischemic stroke patients with minor symptoms and large-vessel occlusion (LVO). Methods: This was a retrospective analysis of a prospective, multicenter, nationwide registry of consecutive patients with acute (within 24 h) minor (National Institutes of Health Stroke Scale score=0–5) ischemic stroke with anterior circulation LVO (acute minor LVO). Brain frailty was stratified according to the presence of an advanced white-matter hyperintensity (WMH) (Fazekas grade 2 or 3), silent/old brain infarct, or cerebral microbleeds. The primary outcome was a composite of stroke, myocardial infarction, and all-cause mortality within 1 year. Results: In total, 1,067 patients (age=67.2±13.1 years [mean±SD], 61.3% males) were analyzed. The proportions of patients according to the numbers of brain frailty burdens were as follows: no burden in 49.2%, one burden in 30.0%, two burdens in 17.3%, and three burdens in 3.5%. In the Cox proportional-hazards analysis, the presence of more brain frailty burdens was associated with a higher risk of 1-year primary outcomes, but after adjusting for clinically relevant variables there were no significant associations between burdens of brain frailty and 1-year vascular outcomes. For individual components of brain frailty, an advanced WMH was independently associated with an increased risk of 1-year primary outcomes (adjusted hazard ratio [aHR]=1.33, 95% confidence interval [CI]=1.03–1.71) and stroke (aHR=1.32, 95% CI=1.00–1.75). Conclusions The baseline imaging markers of brain frailty were common in acute minor ischemic stroke patients with LVO. An advanced WMH was the only frailty marker associated with an increased risk of vascular events. Further research is needed into the association between brain frailty and prognosis in patients with acute minor LVO.

Objective: Vestibular-evoked myogenic potentials (VEMPs) can help in assessing otolithic neural pathway in the brainstem, which may also contribute to the cardiovascular autonomic function. Parkinson’s disease (PD) is associated with altered VEMP responses; however, the associations between VEMP abnormalities and multiple system atrophy (MSA) remain unknown. Therefore, we compared the extent of otolith dysfunction using ocular (oVEMP) and cervical VEMPs between patients with MSA and PD. Methods: We analyzed the clinical features, VEMP, and head-up tilt table test (HUT) findings using the Finometer in 24 patients with MSA and 52 with de novo PD who had undergone neurotologic evaluation at a referral-based university hospital in South Korea from January 2021 to March 2023. Results: MSA was associated with bilateral oVEMP abnormalities (odds ratio [95% confidence interval] = 9.19 [1.77–47.76], p = 0.008). The n1–p1 amplitude was negatively correlated with the Unified Multiple System Atrophy Rating Scale I-II score in patients with MSA (r = -0.571, p = 0.033), whereas it did not correlate with the Movement Disorder Society-Unified Parkinson’s Disease Rating Scale-III score in patients with PD (r = -0.051, p = 0.687). The n1 latency was negatively correlated with maximum changes in systolic blood pressure within 15 s during HUT in patients with PD (r = -0.335, p = 0.040) but not in those with MSA (r = 0.277, p = 0.299). Conclusion Bilaterally abnormal oVEMP responses may indicate the extent of brainstem dysfunction in MSA. oVEMP reflects the integrity of otolith-autonomic interplay, reliably assists in differentiating between MSA and PD, and helps infer clinical decline.