Journal: Leukemia

Article Title: Activity of PROTAC MDM2 degrader in primary leukemia cells and PDX models

doi: 10.1038/s41375-026-02957-8

Figure Lengend Snippet: A IC50 values for MDM2 degrader MD-265 (green circles) and MDM2 inhibitor MI-1061 (red triangles) in primary leukemic stem cells ( N = 100). The values above the line are samples with relative resistance to the inhibitor and degrader. Patient samples resistant to the degrader were also resistant to the inhibitor. B Dose-response curves for MD-265 and MI-1061 in primary LSCs; green curves denote relatively resistant samples. C Median IC50 for MD-265 (MDM2 degrader) and MI-1061 (MDM2 inhibitor) in patient leukemic blasts. The sample size is indicated on top of the bars. Among resistant blasts, the LSCs that had no measurable response were excluded as their predicted IC50 was infinite. D Dose-response curves and IC50 (nM) for MD-265 (circles) and MI-1061 (triangles) in normal HSPCs. E Colony-forming unit (CFU) assay in methylcellulose for one representative sensitive AML (AML-60). Treatments are indicated under the bars: MD265 at 10 nM and 100 nM, MI1061 at 100 nM and 1000 nM, Revlimid alone at 20 nM and UT (no drug control). F CFU for a resistant AML (AML-491). G Colony-forming units from CD34+ HSPCs from a normal donor (N1376). For ( E , F , G ) cells were plated in duplicate wells, treatments are indicated under the bar, and averages are shown with standard deviations. For ( G ), one of three different normal CD34-positive HSPCs tested is shown.

Article Snippet: The authors declare the following competing financial interest(s): The University of Michigan has filed patent applications on this MDM2 degrader, which have been licensed to Ascentage Pharma Group.

Techniques: Colony-forming Unit Assay, Control

Journal: Leukemia

Article Title: Activity of PROTAC MDM2 degrader in primary leukemia cells and PDX models

doi: 10.1038/s41375-026-02957-8

Figure Lengend Snippet: A Molecular characteristics and their frequencies in samples sensitive to the MDM2 degrader. The number in the label depicts the number of samples that carried the gene variant. None and not determined (ND) do not exclude additional mutations. Other mutations include GATA2, SETD2, EPHA2, PMS2, GEN1, JAK2, RUNX1, PRPF40b, SRSF2, ERB4, B Molecular characteristics and their frequency in resistant samples. Other mutations include GATA2, SRSF2, NSD1, JAK2, DPYD, NTRK1.

Article Snippet: The authors declare the following competing financial interest(s): The University of Michigan has filed patent applications on this MDM2 degrader, which have been licensed to Ascentage Pharma Group.

Techniques: Variant Assay

Journal: Leukemia

Article Title: Activity of PROTAC MDM2 degrader in primary leukemia cells and PDX models

doi: 10.1038/s41375-026-02957-8

Figure Lengend Snippet: A Immunoblots of sensitive LSCs (AML-807) treated for 4 h with MD-265 or MI-1061 for MDM2 and p53; MCL-1, as a marker of apoptosis, is also shown; β-actin was used as a loading control. B Dose-response curves for MD-265 (circles) and MI-1061 (triangles) in LSCs (AML-807). C Immunoblots of sensitive primary LSCs (AML-397) treated for 4 h with MD-265 or MI-1061. MDM2, p53 and cleaved caspase-3 are shown as an indicator of apoptosis. D Dose-response curves for MD-265 (circles) and MI-1061 (triangles) in LSCs (AML-397). E Immunoblots to resistant primary AML (AML-703), MDM2 protein, p53 levels and Caspase-3 cleavage in inhibitor and degrader-treated cells (4 h) are shown. F Dose-response in resistant LSCs (AML-703) to MD-265 (circles) and MI-1061 (triangles). In ( B , D , F ) The dose response was measured after treatment for 72 h. Calculated IC50 values are shown in inset table.

Article Snippet: The authors declare the following competing financial interest(s): The University of Michigan has filed patent applications on this MDM2 degrader, which have been licensed to Ascentage Pharma Group.

Techniques: Western Blot, Marker, Control

Journal: Leukemia

Article Title: Activity of PROTAC MDM2 degrader in primary leukemia cells and PDX models

doi: 10.1038/s41375-026-02957-8

Figure Lengend Snippet: LSCs (CD34 positive) derived from an AML patient (AML-587) were injected into NSG-S mice via the tail vein, and treatment was started after the establishment of human cells detectable in the blood. After disease development, 4 mice were assigned to each treatment group: Vehicle, MD-265 and APG-115. A Human CD45-positive cells were measured in peripheral blood by flow cytometry weekly. Dosing: MD-265 25 mg/kg IV once a week; MDM2i, APG115, 200 mg/kg PO three times weekly. B Kaplan–Meier survival of mice bearing AML PDX. Median survival for vehicle-treated mice was 19 days, for APG-115 treated 345 days and for MD265 was undefined. Based on the Log-rank (Mantel-Cox) test, the survival difference p value was 0.0475. The arrow in A and B indicates when treatment was discontinued. Early mortality in mice treated with MDM2 inhibitor MI-1061 was associated with perforation during gavage and rapid loss of weight. AML-587 was associated with NPM1 and FLT3-ITD mutation with normal cytogenetics. One of 3 PDXs is shown in the figures.

Article Snippet: The authors declare the following competing financial interest(s): The University of Michigan has filed patent applications on this MDM2 degrader, which have been licensed to Ascentage Pharma Group.

Techniques: Derivative Assay, Injection, Flow Cytometry, Mutagenesis

Journal: Journal of Extracellular Vesicles

Article Title: Extracellular Vesicle‐Mediated Nucleolin Transfer in Glioblastoma: A Targetable Axis Driving Blood‐Tumour Barrier Formation

doi: 10.1002/jev2.70268

Figure Lengend Snippet: Assembly of an MDM2‐NCL‐PROTAC‐POI quaternary complex. (A) Co‐IP of NCL, MDM2, VEGFR2, and EGFR in U87MG cells using isotype‐matched IgG or an anti‐NCL antibody. (B) Pull‐down assay of NCL, MDM2, VEGFR2, and EGFR in U87MG cells treated with 500 nM biotin‐labelled NC (Bio‐NC) or AS1411 (Bio‐AS1411) for 6 h by streptavidin‐coated magnetic beads. (C) Pull‐down assay of NCL and MDM2 in NCL siRNA (siNCL)‐transfected U87MG cells after treatment with 500 nM Bio‐AS1411 for 6 h. (D) Structure of AS1411‐Ced. (E) Structure of AS1411‐Gef. (F) Absorption spectra of NMM in the presence of 10 µM NC, AS1411, AS1411‐Ced, and AS1411‐Gef. The NMM concentration was 1 µM. (G) Co‐IP of NCL, MDM2, and VEGFR2 in U87MG cells treated with PBS or 500 nM AS1411‐Ced for 6 h using an anti‐VEGFR2 antibody in the presence of 10 µM MG132. (H) Co‐IP of NCL, MDM2, and VEGFR2 in scrambled control siRNA (siCtrl)‐ or siNCL‐transfected U87MG cells after treatment with 500 nM AS1411‐Ced for 6 h using an anti‐VEGFR2 antibody in the presence of 10 µM MG132. (I) Co‐IP of NCL, MDM2, and VEGFR2 in siCtrl or siMDM2‐transfected U87MG cells after treatment with 500 nM AS1411‐Ced for 6 h using an anti‐VEGFR2 antibody in the presence of 10 µM MG132. (J) Co‐IP of NCL, MDM2, and EGFR in U87MG cells treated with PBS or 500 nM AS1411‐Gef for 6 h using an anti‐EGFR antibody in the presence of 10 µM MG132. (K) Co‐IP of NCL, MDM2, and EGFR in siCtrl‐ or siNCL‐transfected U87MG cells after treatment with 500 nM AS1411‐Gef for 6 h using an anti‐EGFR antibody in the presence of 10 µM MG132. (L) Co‐IP of NCL, MDM2, and EGFR in siCtrl‐ or siMDM2‐transfected U87MG cells after treatment with 500 nM AS1411‐Gef for 6 h using an anti‐EGFR antibody in the presence of 10 µM MG132. Experiments were performed in triplicate and repeated three times.

Article Snippet: Following blocking with 5% non‐fat dry milk in TBST, the membrane was incubated overnight at 4°C with primary antibodies against VEGFR2 (1:1000, CST, USA), EGFR (1:1000, CST, USA), NCL (1:1000, Proteintech, CHN), TSG101 (1:500, Abclonal, CHN), CD63 (1:500, Proteintech, CHN), MDM2 (1:1000, Proteintech, CHN), Na + /K + ‐ATPases (1:1000, Proteintech, CHN) and ACTIN (1:2000, Abclonal, CHN).

Techniques: Co-Immunoprecipitation Assay, Pull Down Assay, Magnetic Beads, Transfection, Concentration Assay, Control

Journal: Journal of Extracellular Vesicles

Article Title: Extracellular Vesicle‐Mediated Nucleolin Transfer in Glioblastoma: A Targetable Axis Driving Blood‐Tumour Barrier Formation

doi: 10.1002/jev2.70268

Figure Lengend Snippet: Targeting NCL for the development of the BTB‐penetrating and GBM‐specific PROTACs. (A) No transfer of NCL from astrocytes to the surface of brain capillary endothelial cells via EVs, maintaining the normal function of the BBB. (B) EV‐mediated transfer of NCL from GBM cells to the surface of brain capillary endothelial cells, facilitating the transformation of the BBB into the BTB. (C) Transcytosis of AS1411 across the BTB in an NCL‐dependent manner, enabling its selective accumulation in GBM cells. (D) Development of BTB‐penetrating, GBM‐targeting PROTACs via conjugating AS1411 with ligands of POIs such as VEGFR2 and EGFR. Briefly, the AS1411‐based PROTACs traverse the BTB, enter GBM cells selectively, and bring the POIs into proximity with the NCL‐MDM2 complex. This spatial arrangement induces POI ubiquitination and subsequent proteasomal degradation, leading to targeted anti‐GBM therapy.

Article Snippet: Following blocking with 5% non‐fat dry milk in TBST, the membrane was incubated overnight at 4°C with primary antibodies against VEGFR2 (1:1000, CST, USA), EGFR (1:1000, CST, USA), NCL (1:1000, Proteintech, CHN), TSG101 (1:500, Abclonal, CHN), CD63 (1:500, Proteintech, CHN), MDM2 (1:1000, Proteintech, CHN), Na + /K + ‐ATPases (1:1000, Proteintech, CHN) and ACTIN (1:2000, Abclonal, CHN).

Techniques: Transformation Assay, Ubiquitin Proteomics

Journal: The Journal of Biological Chemistry

Article Title: PLLP inhibits the progression of WT p53 gastric cancer by reducing p53 protein ubiquitination by binding to TRIM59

doi: 10.1016/j.jbc.2026.111341

Figure Lengend Snippet: Regulation of the ubiquitination of WT p53 in GC by PLLP. A , p53 protein degradation in the cells was detected by Western blotting ( n = 3). B , Co-IP was used to detect the ubiquitination of the p53 protein. C , Western blotting was used to detect the protein level of MDM2 after PLLP overexpression ( n = 3). D , Western blotting was used to detect the protein level of MDM2 after PLLP knockdown ( n = 3). E , the protein levels of PLLP and p53 were detected by Western blotting ( n = 3). F and G , protein band. Compared with the pcDNA-NC + CHX (0 h) or si-NC + DMSO group, ∗∗ p < 0.01; compared with the pcDNA-PLLP + CHX (0 h) or si-NC + nutlin-3 group, # p < 0.05, ## p < 0.01; compared with the pcDNA-NC + CHX (1 h), && p < 0.01; compared with the pcDNA-NC + CHX (3 h), △ p < 0.05, △△ p < 0.01; and compared with the pcDNA-NC + CHX (6 h), ▲ p < 0.05, ▲▲ p < 0.01. Co-IP, coimmunoprecipitation; DMSO, dimethyl sulfoxide; GC, gastric cancer; PLLP, plasmolipin.

Article Snippet: Protein samples were electrophoresed on 12% sodium dodecylsulfate-polyacrylamide gels, transferred to polyvinylidene fluoride membranes, blocked with 5% skim milk for 2 h at room temperature, and incubated with primary antibodies (PLLP [1:1000 dilution, Proteintech]; p53 [1:5000 dilution, Proteintech]; p21 [1:2000 dilution, Proteintech]; BAX [1:2000 dilution, ABclonal]; MDM2 (1:1000 dilution, HUABIO; and TRIM59 [1:1000 dilution, Proteintech]) at 4 °C overnight.

Techniques: Ubiquitin Proteomics, Western Blot, Co-Immunoprecipitation Assay, Over Expression, Knockdown