Combined inhibition of Bcl-2 family members and YAP induces synthetic lethality in metastatic gastric cancer with RASA1 and NF2 deficiency.

BACKGROUND: Targetable molecular drivers of gastric cancer (GC) metastasis remain largely unidentified, leading to limited targeted therapy options for advanced GC. We aimed to identify molecular drivers for metastasis and devise corresponding therapeutic strategies. METHODS: We performed an unbiased in vivo genome-wide CRISPR/Cas9 knockout (KO) screening in peritoneal dissemination using genetically engineered GC mouse models. Candidate genes were validated through in vivo transplantation assays using KO cells. We analyzed target expression patterns in GC clinical samples using immunohistochemistry. The functional contributions of target genes were studied through knockdown, KO, and overexpression approaches in tumorsphere and organoid assays. Small chemical inhibitors against Bcl-2 members and YAP were tested in vitro and in vivo. RESULTS: We identified Nf2 and Rasa1 as metastasis-suppressing genes through the screening. Clinically, RASA1 mutations along with low NF2 expression define a distinct molecular subtype of metastatic GC exhibiting aggressive traits. NF2 and RASA1 deficiency increased in vivo metastasis and in vitro tumorsphere formation by synergistically amplifying Wnt and YAP signaling in cancer stem cells (CSCs). NF2 deficiency enhanced Bcl-2-mediated Wnt signaling, conferring resistance to YAP inhibition in CSCs. This resistance was counteracted via synthetic lethality achieved by simultaneous inhibition of YAP and Bcl-2. RASA1 deficiency amplified the Wnt pathway via Bcl-xL, contributing to cancer stemness. RASA1 mutation created vulnerability to Bcl-xL inhibition, but the additional NF2 deletion conferred resistance to Bcl-xL inhibition due to YAP activation. The combined inhibition of Bcl-xL and YAP synergistically suppressed cancer stemness and in vivo metastasis in RASA1 and NF2 co-deficiency. CONCLUSION: Our research unveils the intricate interplay between YAP and Bcl-2 family members, which can lead to synthetic lethality, offering a potential strategy to overcome drug resistance. Importantly, our findings support a personalized medicine approach where combined therapy targeting YAP and Bcl-2, tailored to NF2 and RASA1 status, could effectively manage metastatic GC.

SARS-CoV-2 Omicron variant causes brain infection with lymphoid depletion in a mouse COVID-19 model.

BACKGROUND: The Omicron variant has become the most prevalent SARS-CoV-2 variant. Omicron is known to induce milder lesions compared to the original Wuhan strain. Fatal infection of the Wuhan strain into the brain has been well documented in COVID-19 mouse models and human COVID-19 cases, but apparent infections into the brain by Omicron have not been reported in human adult cases or animal models. In this study, we investigated whether Omicron could spread to the brain using K18-hACE2 mice susceptible to SARS-CoV-2 infection. RESULTS: K18-hACE2 mice were intranasally infected with 1 × 105 PFU of the original Wuhan strain and the Omicron variant of SARS-CoV-2. A follow-up was conducted 7 days post infection. All Wuhan-infected mice showed > 20% body weight loss, defined as the lethal condition, whereas two out of five Omicron-infected mice (40%) lost > 20% body weight. Histopathological analysis based on H&E staining revealed inflammatory responses in the brains of these two Omicron-infected mice. Immunostaining analysis of viral nucleocapsid protein revealed severe infection of neuron cells in the brains of these two Omicron-infected mice. Lymphoid depletion and apoptosis were observed in the spleen of Omicron-infected mice with brain infection. CONCLUSION: Lethal conditions, such as severe body weight loss and encephalopathy, can occur in Omicron-infected K18-hACE2 mice. Our study reports, for the first time, that Omicron can induce brain infection with lymphoid depletion in the mouse COVID-19 model.

Murine Coronavirus Disease 2019 Lethality Is Characterized by Lymphoid Depletion Associated with Suppressed Antigen-Presenting Cell Functionality.

The disease severity of coronavirus disease 2019 (COVID-19) varies considerably from asymptomatic to serious, with fatal complications associated with dysregulation of innate and adaptive immunity. Lymphoid depletion in lymphoid tissues and lymphocytopenia have both been associated with poor disease outcomes in patients with COVID-19, but the mechanisms involved remain elusive. In this study, human angiotensin-converting enzyme 2 (hACE2) transgenic mouse models susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were used to investigate the characteristics and determinants of lethality associated with the lymphoid depletion observed in SARS-CoV-2 infection. The lethality of Wuhan SARS-CoV-2 infection in K18-hACE2 mice was characterized by severe lymphoid depletion and apoptosis in lymphoid tissues related to fatal neuroinvasion. The lymphoid depletion was associated with a decreased number of antigen-presenting cells (APCs) and their suppressed functionality below basal levels. Lymphoid depletion with reduced APC function was a specific feature observed in SARS-CoV-2 infection but not in influenza A infection and had the greatest prognostic value for disease severity in murine COVID-19. Comparison of transgenic mouse models resistant and susceptible to SARS-CoV-2 infection revealed that suppressed APC function could be determined by the hACE2 expression pattern and interferon-related signaling. Thus, we demonstrated that lymphoid depletion associated with suppressed APC function characterizes the lethality of COVID-19 mouse models. Our data also suggest a potential therapeutic approach to prevent the severe progression of COVID-19 by enhancing APC functionality.

The effects of dual-task training on balance and gross motor function in children with spastic diplegia.

The purpose of this study was to investigate changes in dynamic balance and gross motion function when dual-task training was performed on an unstable support surface by children with spastic diplegia. The subjects of this study were 14 children (experimental group n=7, control group n=7) who were medical diagnosed with spastic diplegia. Both groups were administered treatment for 30 min, 2 times a week for 8 weeks, with the experimental group performing dual-task exercise in which cognitive tasks related to daily living were performed while maintaining balance on an unstable surface, and the control group being administered neurodevelopmental treatment. Balance and gross motor function Assessments were conducted before intervention and after 8 weeks of intervention. Wilcoxon signed-rank test was performed to analyze changes in balance, gross motor function in the group, and the Mann-Whitney test was conducted to compare the differences between the two groups before and after intervention. The results showed that there was a statistically significant difference in both groups when balance in a sitting position and gross motor function (P<0.05). There was a statistically significant difference between the two groups in balance and gross motor function assessment (P<0.05). Based on the results of this study, it was confirmed that dual-task training improves balance, gross motor function in children with spastic diplegia. Therefore, dual-task training may be considered as an effective method of intervention method in the functional aspect of children with spastic diplegia.

[A field study of posttraumatic stress disorder in a community after Typhoon Rusa].

PURPOSE: In South Korea, as growing the need of psychological support in disaster situation psychological assessment on stress after disaster is important to find out the factors affecting coping, and to plan intervention in the community. METHOD: The volunteers of Korea Redcross who live around K city, and the research team visited all homes at Jirye town, one of the high-impact area, 4 month after the typhoon. One of the family members who is over 18 years old, answered the self-report questionnaire composed of disaster experience, damage, exposure to traumatic event, and posttraumatic stress with IES-K (Impact of Event Scale-korea) He also, described his family members symptom related to re-experiencing, hyper-arousal, and avoidance. Six hundreds households were surveyed. RESULT: The prevalence of moderate to severe PTSD symptom was 36% of the subjects. The severity of PTSD was affected by gender, economic status and affected by damaged property, physical injury, worsening existing disease, getting infectious disease, amount of experienced traumatic event before disaster, warning, taking shelter, and subjects revealed differences in somatization as severity of PTSD. According to the description, community members had re-experiencing, hyper-arousal and avoidance. CONCLUSION: At a rural area, South Korea, community members have suffered from psychological distress after disaster. So psychological interventions are required as affecting factors and also to plan for warning and shelter in disaster situation is needed for preventing PTSD.