Site-specific mutagenesis screening in KRASG12D mutant library to uncover resistance mechanisms to KRASG12D inhibitors.

KRAS plays a crucial role in regulating cell survival and proliferation and is one of the most commonly mutated oncogenes in human cancers. The novel KRASG12D inhibitor, MRTX1133, demonstrates promising antitumor efficacy in vitro and in vivo. However, the development of acquired resistance in treated patients presents a considerable challenge to sustained therapeutic effectiveness. In response to this challenge, we conducted site-specific mutagenesis screening to identify potential secondary mutations that could induce resistance to MRTX1133. We screened a range of KRASG12D variants harboring potential secondary mutations, and 44 representative variants were selected for in-depth validation of the pooled screening outcomes. We identified eight variants (G12D with V9E, V9W, V9Q, G13P, T58Y, R68G, Y96W, and Q99L) that exhibited substantial resistance, with V9W showing notable resistance, and downstream signaling analyses and structural modeling were conducted. We observed that secondary mutations in KRASG12D can lead to acquired resistance to MRTX1133 and BI-2865, a novel pan-KRAS inhibitor, in human cancer cell lines. This evidence is critical for devising new strategies to counteract resistance mechanisms and, ultimately, enhance treatment outcomes in patients with KRASG12D-mutant cancers.

COX-2 Acts as a Key Mediator of Trifluoperazine-induced Cell Death in U87MG Glioma Cells.

BACKGROUND/AIM: Glioblastoma multiforme (GBM) is one of the most common brain tumors with a poor prognosis. Previously, we reported that trifluoperazine (TFP), a well-known antipsychotic, has anti-glioma activity through the modulation of intracellular calcium levels. The present study aimed to investigate the anti-cancer mechanism of action of TFP on glioma cells. MATERIALS AND METHODS: The effect of TFP on U87MG cells was examined using a viability assay, flow cytometry, enzyme-linked immunosorbent assay, quantitative real-time PCR, western blot analysis, colony formation, and immunocytochemistry. RESULTS: TFP treatment decreased cell viability. To test the possible involvement of COX-2 in the anticancer activity of TFP on U87MG cells, a COX-2 inhibitor was applied. COX-2 inhibitor pretreatment restored TFP-induced reduction in viability to the control level. Additionally, TFP-induced changes in the apoptotic cell population, production of prostaglandins (PGE2, PGD2, 15d-PGJ2), and nuclear translocation of peroxisome proliferator-activated receptor γ (PPARγ) were ameliorated by COX-2 inhibitor pretreatment. CONCLUSION: TFP suppressed the proliferation of U87MG glioma cell in a COX-2/PPARγ-dependent manner.

Delirium-related factors and their prognostic value in patients undergoing craniotomy for brain metastasis.

Background: Delirium is characterized by acute brain dysfunction. Although delirium significantly affects the quality of life of patients with brain metastases, little is known about delirium in patients who undergo craniotomy for brain metastases. This study aimed to identify the factors influencing the occurrence of delirium following craniotomy for brain metastases and determine its impact on patient prognosis. Method: A total of 153 patients who underwent craniotomy for brain metastases between March 2013 and December 2020 were evaluated for clinical and radiological factors related to the occurrence of delirium. Statistical analysis was conducted by dividing the patients into two groups based on the presence of delirium, and statistical significance was confirmed by adjusting the clinical characteristics of the patients with brain metastases using propensity score matching (PSM). The effect of delirium on patient survival was subsequently evaluated using Kaplan-Meier analysis. Results: Of 153 patients, 14 (9.2%) had delirium. Age (P = 0.002), sex (P = 0.007), and presence of postoperative hematoma (P = 0.001) were significantly different between the delirium and non-delirium groups. When the matched patients (14 patients in each group) were compared using PSM, postoperative hematoma showed a statistically significant difference (P = 0.036) between the delirium and non-delirium groups. Kaplan-Meier survival analysis revealed that the delirium group had poorer prognosis (log-rank score of 0.0032) than the non-delirium group. Conclusion: In addition to the previously identified factors, postoperative hematoma was identified as a strong predictor of postoperative delirium. Also, the negative impact of delirium on patient prognosis including low survival rate was confirmed.

Heterogeneous and Monolithic 3D Integration of III-V-Based Radio Frequency Devices on Si CMOS Circuits.

Next-generation wireless communication such as sixth-generation (6G) and beyond is expected to require high-frequency, multifunctionality, and power-efficiency systems. A III-V compound semiconductor is a promising technology for high-frequency applications, and a Si complementary metal-oxide-semiconductor (CMOS) is the never-beaten technology for highly integrated digital circuits. To harness the advantages of these two technologies, monolithic integration of III-V and Si electronics is beneficial, so that there have been everlasting efforts to accomplish the monolithic integration. Considering that the on horizon 6G wireless communication requires faster and more energy-efficient system-on-chip technologies, it is imperative to realize a radio frequency (RF) system in which III-V technology and Si CMOS technology are integrated at a device level. Here we report heterogeneous and monolithic three-dimensional (3D) analog/RF-digital mixed-signal integrated circuits that contain two types of InGaAs high-electron-mobility transistors (HEMTs) designed for high fT and fMAX in the top and Si CMOS mixed-signal circuits consisting of an analog-to-digital converter and digital-to-analog converter in the bottom. A high unity current gain cutoff frequency of 448 GHz and unity power gain cutoff frequency of 742 GHz have been achieved by the fT oriented and fMAX oriented InGaAs HEMTs, respectively, without being affected by mixed-signal interference. At the same time, the bottom Si CMOS circuits provide valid signals without any performance degradation by the integration process.

Resveratrol prevents hypoxia-induced retinal ganglion cell death related with ErbB2.

AIM: To confirm the changes in proteins related with hypoxia-induced retinal cell death and to assess the effects of resveratrol (Res). METHODS: The therapeutic effect of Res was verified using an ischemic/reperfusion (I/R) model in vivo and a hypoxia modelin retinal ganglion cells (RGCs) in vitro. Death of RGCs were confirmed by TUNEL assay. Protein expression was confirmed by Western blotting and immunohistochemistry. In addition, flow cytometric analysis was used to confirm the response in the cell unit to obtain more accurate data. RESULTS: ErbB2 expression and apoptosis in the ganglion cell layer (GCL) increased after I/R injury. Treatment of Res rescued I/R-induced ganglion cell death, downregulated apoptosis and ErbB2 protein expression in the retina. In subsequent in vitro models, Res affects apoptosis by regulating the phosphorylation and expression of mouse double minute 2 homolog (MDM2), along with those of ErbB2. These results suggest that Res reverses GCL-specific apoptosis via downregulation of ErbB2 in ischemic injury. CONCLUSION: In light of Res favorable properties, it should be evaluated in the treatment of RGC death and related retinal disease characterized by ErbB2 and MDM2 expression. Therefore, Res is appropriate therapeutic agent for treating ischemic injury-related eye diseases by targeting the expression of ErbB2 and MDM2.

Size distribution of serum extracellular vesicles in mice with atherosclerosis.

BACKGROUND AND AIMS: Atherosclerosis is a prominent vascular lesion, and potentially causing ischemic alterations in the brain and heart. Recent studies have reported that physiological and pathological alterations in atherosclerosis and extracellular vesicles (EV) are related. This study aimed to investigate the association between the extent of atherosclerotic lesions and the number of serum EVs in a mouse model of atherosclerosis (wild-type). METHODS: Eighteen 3-week-old C57BL/6 N male mice(wild-type) were purchased. Twelve mice were fed a 45% high-fat diet (HFD) for six months. Six mice were provided standard laboratory chow for six months. The entire aorta, from the aortic sinus to the division of the iliac artery, was dissected out from each mouse. Furthermore, the degree of atherosclerosis was microscopically determined. Serum EVs were quantified by size via nanoparticle tracking analysis. RESULTS: The number of EVs in the high-atherosclerotic score group (1.43 × 109) was higher than that in the low- atherosclerotic score group (0.7 × 109) in the range of 211.5-222.5 nm (p = 0.033). CONCLUSIONS: Enumeration of EVs is a potential method of detecting atherosclerosis.

Anti-obesity Activity of Ethanol Extract from Bitter Melon in Mice Fed High-Fat Diet.

In many cases, obesity is associated with metabolic disorders. Recently, natural compounds that may be beneficial for improving obesity have received increasing attention. Bitter melon has received attention as a diabetes treatment. NAD+-dependent deacetylase (Sirtuin 1, SIRT1) has emerged as a novel therapeutic target for metabolic diseases. In this study, ethanol extract of bitter melon (BME) suppressed adipocyte differentiation and significantly increased the expression of SIRT1 in fully differentiated 3T3-L1 cells. Moreover, it enhanced the activation of AMP-activated protein kinase (AMPK). In high-fat diet (HFD)-fed induced-obesity mice, BME suppressed HFD-induced increases in body weight and white adipose tissue (WAT) weight. BME also increased the expression of SIRT1 and suppressed peroxisome proliferator-activated receptor and sterol regulatory element binding protein 1 expressions of WAT from HFD-fed mice. These findings suggest that BME prevents obesity by activating the SIRT1 and AMPK pathway and that it may be a useful dietary supplement for preventing obesity.

Anti-diabetic Effects of Ethanol Extract from Bitter Melon in Mice Fed a High-fat Diet.

Present study aimed to determine the effect of 'bitter melon', a popularly used fruit in Bangladesh and several other Asian countries, on high-fat-diet-induced type 2 diabetes. To investigate the effect, ethanol extract from bitter melon (BME) as a dietary supplement with mouse chow was used. BME was found to significantly attenuate the high-fat diet (HFD) -induced body weight and total fat mass. BME also effectively reduced the insulin resistance induced by the HFD. Furthermore, dietary supplementation of BME was highly effective in increasing insulin sensitivity and reducing hepatic fat and obesity. These results indicate that BME could be effective in attenuating type 2 diabetes and could therefore be a preventive measure against type 2 diabetes.