Journal: BMC Cancer

Article Title: FOXL2 + cancer-associated fibroblasts enhances epithelial ovarian cancer development via TGFβ/Smad signaling

doi: 10.1186/s12885-025-15364-6

Figure Lengend Snippet: FOXL2 SUMOylation intricately regulates increased expression in CAFs. ( A ) SUMOylation sites of FOXL2 was analyzed by SUMOplot™ analysis. Shown are the top 7 predicted lysine residues; ( B ) In vitro sumoylation assay was employed to confirm the predicted SUMOylation sites using HA-tagged wild-type (WT), or the K25R, K87R, K114R, K150R, and 4KR (where K25, K87, K114 and K150 were all mutated to R). Shown is a representative blot and densitometry analysis of SUMOylated-FOXL2/Total FOXL2; ( C ) The association between SUMOylation and FOXL2 stability was determined by western blotting in HEK-293T cells using α-HA. Cells were transfected with either HA-FOXL2-WT or HA-FOXL2-K25/87R (double mutant, 2KR). The membrane was stripped and re-probed with GAPDH to confirm equivalent loading. Shown is a representative blot and densitometry analysis of three technical replicates; ( D ) Cells were transfected with HA-FOXL2-WT or, HA-FOXL2-2KR ± His-SUMO1. CHX (100 µg/ml) was added to inhibit translation allowing tracking of FOXL2 stability in the presence and absence of His-SUMO1. Blots were probed with α-HA and re-probed with GAPDH to confirm equivalent loading. Shown is a representative blot and densitometry analysis of three technical replicates; ( E ) DMSO (control), MG132 (proteasome inhibitor) or chloroquine (lysosome inhibitor) were added into HEK-293T cells transfected with HA-FOXL2-WT or HA-FOXL2-2KR, before CHX (100 µg/ml) was added. Blots were probed with α-HA and re-probed with GAPDH to confirm equivalent loading. Shown is a representative blot; ( F ) IP assay was used to test the association between FOXL2 SUMOylation and ubiquitination. Lysates obtained from HEK-293T cells transfected with HA-FOXL2-WT or HA-FOXL2-2KR, along with FLAG-UBC9, were immunoprecipitated using α-HA antibody and then probed with α-FLAG antibody. Shown is a representative blot; *, *** P < 0.05, P < 0.001

Article Snippet: The different primary antibodies used were α-SUMO1 (67559-1-Ig, 1:3000), α-UBC9 (10070-1-AP, 1:2000), α-Vimentin (10366-1-AP, 1:5000), α-N-cadherin (22018-1-AP, 1:5000), α-E-cadherin (20874-1-AP, 1:20000) (Proteintech, Wuhan, China); α-HA (A02041, 1:800), α-His (A02050, 1:800), α-Flag (A02010, 1:800) (Abbkine, Wuhan, China); α-FOXL2 (ab246511, 1:1000), α-Snail (ab216347, 1:1000) (Abcam, Cambridge, MA, USA); and, α-Smad2/3 (D7G7, 1:1000), α-p-Smad2 (Ser465/467)/Smad3 (Ser423/425) (D27F4, 1:1000) (CST, Boston, MA, USA).

Techniques: Expressing, In Vitro, Western Blot, Transfection, Mutagenesis, Membrane, Control, Ubiquitin Proteomics, Immunoprecipitation

Journal: BMC Cancer

Article Title: FOXL2 + cancer-associated fibroblasts enhances epithelial ovarian cancer development via TGFβ/Smad signaling

doi: 10.1186/s12885-025-15364-6

Figure Lengend Snippet: FOXL2 SUMOylation requires SUMO1 and UBC9/UBE2I. ( A ) Putative interaction of FOXL2 with SUMO1, SUMO2, SUMO3, and SUMO4 was detected by String analysis ( https://cn.string-db.org/ ); ( B ) In vitro sumoylation assay was employed to confirm String analysis’s prediction of SUMO1, HEK-293T cells were transfected with HA-FOXL2-WT, FLAG-UBC9, and His-SUMO1-4. In vitro SUMOylation assay using Ni 2+ -NTA pull-down determined that FOXL2 was mainly modified by SUMO1. Shown is a representative blot; ( C ) In vitro sumoylation assay was employed to determine whether UBC9 is compulsorily required for FOXL2 SUMOylation. HEK-293T cells were transfected with HA-FOXL2-WT and His-SUMO1 ± FLAG-UBC9. In vitro SUMOylation using Ni 2+ -NTA pull-down assay determined that UBC9 is required for FOXL2 SUMOylation. Shown is a representative blot; ( D ) In vitro sumoylation assay was employed to determine whether UBC9 is compulsorily required for FOXL2 SUMOylation in CAFs. CAFs were transduced using either a non-targeting control shRNA or shRNA targeting UBC9 . Transduced cells were transfected with HA-FOXL2-WT and His-SUMO1. In vitro SUMOylation using Ni 2+ -NTA pull-down assay determined that UBC9 is required for FOXL2 SUMOylation. Shown is a representative blot

Article Snippet: The different primary antibodies used were α-SUMO1 (67559-1-Ig, 1:3000), α-UBC9 (10070-1-AP, 1:2000), α-Vimentin (10366-1-AP, 1:5000), α-N-cadherin (22018-1-AP, 1:5000), α-E-cadherin (20874-1-AP, 1:20000) (Proteintech, Wuhan, China); α-HA (A02041, 1:800), α-His (A02050, 1:800), α-Flag (A02010, 1:800) (Abbkine, Wuhan, China); α-FOXL2 (ab246511, 1:1000), α-Snail (ab216347, 1:1000) (Abcam, Cambridge, MA, USA); and, α-Smad2/3 (D7G7, 1:1000), α-p-Smad2 (Ser465/467)/Smad3 (Ser423/425) (D27F4, 1:1000) (CST, Boston, MA, USA).

Techniques: In Vitro, Transfection, Modification, Pull Down Assay, Control, shRNA

Journal: Science Advances

Article Title: Deubiquitinase USP8 regulates the spindle assembly checkpoint in oocytes

doi: 10.1126/sciadv.aeb2345

Figure Lengend Snippet: ( A ) Representative images of USP8 localization in oocytes. Mouse oocytes were immunostained with USP8 and α-tubulin antibodies. Scale bar, 20 μm. ( B ) Representative images of USP8-mCherry localization during mouse oocyte meiosis. Mouse oocytes were microinjected with USP8-mCherry mRNA at the GV stage, maintained for 2 hours in 50 μM IBMX before being washed into IBMX-free medium to allow development to GVBD and MI stages, followed by DNA staining with Hoechst. Scale bar, 20 μm. ( C ) Protein levels of USP8 during oocyte meiosis were examined at the GV, GVBD, MI, and MII stages using immunoblotting analysis. The blots were probed with anti-USP8 antibody, anti–Cyclin B1 antibody, and anti-Cofilin antibody, respectively. The band intensity of USP8 was normalized with that of Cofilin. The GV-stage oocyte is characterized by a distinct GV, enabling clear morphological identification. The GVBD stage is defined by the recent breakdown and disappearance of the GV, whereas the MII stage can be identified by the presence of a prominent first polar body. Meanwhile, Cyclin B1 protein levels are dynamically regulated during oocyte meiotic maturation, gradually increasing from the GV to MI stage and subsequently decreasing at the MII stage compared to MI. Thus, these Cyclin B1 expression patterns can serve as supplementary indicators for determining oocyte meiotic maturation stages.

Article Snippet: The blots were further blocked in TBST containing 5% low-fat dry milk for 1 hour at room temperature and then incubated with USP8 (1:500; Abclonal, A7031), USP8 (1:500; Proteintech, 67321-1-Ig), Cyclin B1 (1:1000; Cell Signaling Technology, 4135), BUB3 (1:1000; Abcam, ab133699), BUBR1 (1:1000; Abcam, Ab28193), MAD2 (1:1000; Proteintech, 10337-1-AP), CDC20 (1:500; Proteintech, 10252-1-AP), BUB1 (1:1000; Abcam, Ab195268 ), MPS1 (1:500; Proteintech, 10381-1-AP), Flag (1:1000; Sigma-Aldrich, F3165), HA (1:1000; Sigma-Aldrich, H9658), MYC (1:1000; Cell Signaling Technology, 2278), Normal Rabbit IgG (1:1000; Cell Signaling Technology, 2729), or Cofilin (1:5000; Proteintech, 66057-1-Ig) antibodies at 4°C overnight.

Techniques: Staining, Western Blot, Expressing

Journal: Science Advances

Article Title: Deubiquitinase USP8 regulates the spindle assembly checkpoint in oocytes

doi: 10.1126/sciadv.aeb2345

Figure Lengend Snippet: ( A ) Representative images of the occurrence of GVBD in control and USP8-KD. Scale bar, 100 μm. ( B ) The incidences of GVBD were quantified in control ( n = 118) and USP8-KD ( n = 108) oocytes. ( C ) Representative images of PBE in control, USP8-KD, and USP8-rescued oocytes at the time point of 7 hours post-GVBD. Scale bar, 100 μm. ( D ) Quantitative analysis of PBE rates was shown in control ( n = 126), USP8-KD ( n = 122), and USP8-rescue ( n = 116) oocytes at consecutive time points of post-GVBD. ( E ) Protein levels of USP8 were assessed by immunoblots in control, USP8-KD, and USP8-rescue oocytes. The blots were probed with USP8 and Cofilin antibodies. ( F ) The proportion of oocytes overriding MI arrest following nocodazole treatment was recorded in control ( n = 101), USP8-KD ( n = 102), and USP8-rescue ( n = 99) oocytes. Oocytes injected with the indicated siRNA and/or mRNA were cultured with 400 nM nocodazole from 4 hours post-GVBD, and the PBE rate was scored at 10 hours post-GVBD. Data were presented as the mean value (means ± SEM) of at least three independent experiments. * P < 0.05; ** P < 0.01; n.s., not significant.

Article Snippet: The blots were further blocked in TBST containing 5% low-fat dry milk for 1 hour at room temperature and then incubated with USP8 (1:500; Abclonal, A7031), USP8 (1:500; Proteintech, 67321-1-Ig), Cyclin B1 (1:1000; Cell Signaling Technology, 4135), BUB3 (1:1000; Abcam, ab133699), BUBR1 (1:1000; Abcam, Ab28193), MAD2 (1:1000; Proteintech, 10337-1-AP), CDC20 (1:500; Proteintech, 10252-1-AP), BUB1 (1:1000; Abcam, Ab195268 ), MPS1 (1:500; Proteintech, 10381-1-AP), Flag (1:1000; Sigma-Aldrich, F3165), HA (1:1000; Sigma-Aldrich, H9658), MYC (1:1000; Cell Signaling Technology, 2278), Normal Rabbit IgG (1:1000; Cell Signaling Technology, 2729), or Cofilin (1:5000; Proteintech, 66057-1-Ig) antibodies at 4°C overnight.

Techniques: Control, Western Blot, Injection, Cell Culture

Journal: Science Advances

Article Title: Deubiquitinase USP8 regulates the spindle assembly checkpoint in oocytes

doi: 10.1126/sciadv.aeb2345

Figure Lengend Snippet: ( A ) Protein levels of the MCC were assessed by immunoblots in control and USP8-depleted oocytes. The blots were probed with USP8, BUBR1, CDC20, BUB3, MAD2, and Cofilin antibodies. ( B ) Localization of BUB3 at the prometaphase I stage in control, USP8-KD, and USP8-rescue oocytes. At 3 hours after GVBD, oocytes were fixed and immunostained for BUB3, CREST, and DNA (Hoechst). Scale bar, 10 μm. ( C ) The relative fluorescence intensities of BUB3 to CREST were measured in control ( n = 200, kinetochores), USP8-KD ( n = 200, kinetochores), and USP8-rescue ( n = 200, kinetochores) oocytes. The signal intensity of BUB3 was normalized with that of CREST. ( D ) Protein levels of BUB3 were assessed by immunoblots in control, USP8-KD, and USP8-rescue oocytes. ( E ) Co-IP result showing the USP8 interaction with BUB3 in oocytes. Mouse oocytes were microinjected with USP8-Flag and BUB3-HA cRNA together or USP8-Flag cRNA alone, maintained for a further 4 hours in 200 μM IBMX to allow time for translation. Target proteins were immunoprecipitated using anti-Flag beads and subjected to Western blotting with Flag and HA antibodies. Input oocyte lysates were immunoblotted with anti-HA antibody to determine the expression of BUB3. ( F ) Co-IP result showing the BUB3 interaction with USP8 in oocytes. Mouse oocytes were microinjected with BUB3-HA and USP8-Flag cRNA together or BUB3-HA cRNA alone, maintained for a further 4 hours in 200 μM IBMX to allow time for translation. Target proteins were immunoprecipitated using anti-HA beads and subjected to Western blotting with HA and Flag antibodies. Input oocyte lysates were immunoblotted with anti-Flag antibody to determine the expression of USP8. Data were presented as the mean percentage (means ± SEM) of at least three independent experiments. *** P < 0.001.

Article Snippet: The blots were further blocked in TBST containing 5% low-fat dry milk for 1 hour at room temperature and then incubated with USP8 (1:500; Abclonal, A7031), USP8 (1:500; Proteintech, 67321-1-Ig), Cyclin B1 (1:1000; Cell Signaling Technology, 4135), BUB3 (1:1000; Abcam, ab133699), BUBR1 (1:1000; Abcam, Ab28193), MAD2 (1:1000; Proteintech, 10337-1-AP), CDC20 (1:500; Proteintech, 10252-1-AP), BUB1 (1:1000; Abcam, Ab195268 ), MPS1 (1:500; Proteintech, 10381-1-AP), Flag (1:1000; Sigma-Aldrich, F3165), HA (1:1000; Sigma-Aldrich, H9658), MYC (1:1000; Cell Signaling Technology, 2278), Normal Rabbit IgG (1:1000; Cell Signaling Technology, 2729), or Cofilin (1:5000; Proteintech, 66057-1-Ig) antibodies at 4°C overnight.

Techniques: Western Blot, Control, Fluorescence, Co-Immunoprecipitation Assay, Immunoprecipitation, Expressing

Journal: Science Advances

Article Title: Deubiquitinase USP8 regulates the spindle assembly checkpoint in oocytes

doi: 10.1126/sciadv.aeb2345

Figure Lengend Snippet: ( A ) mRNA levels of BUB3 were determined by reverse transcription quantitative polymerase chain reaction in control and USP8-KD oocytes. ( B ) Protein levels of BUB3 in control, USP8-KD, and USP8-KD + MG132 (25 μM) oocytes. The blots were probed with BUB3 and Cofilin antibodies. DMSO, dimethyl sulfoxide. ( C ) Immunoblotting analysis showing BUB3 protein levels in control oocytes and oocytes treated with the broad-spectrum DUB inhibitor PR-619 (10 μM). ( D ) Immunoblotting analysis of BUB3 protein levels in control and DUB-IN-2 (20 μM)–treated oocytes, where DUB-IN-2 is a specific inhibitor of USP8 deubiquitinating activity. ( E ) Localization of BUB3 at the prometaphase I stage in control and DUB-IN-2–treated oocytes. At 3 hours after GVBD, oocytes were fixed and immunostained for BUB3, CREST, and DNA (Hoechst). Scale bar, 10 μm. ( F ) The relative fluorescence intensities of BUB3 to CREST were measured in control ( n = 200, kinetochores) and DUB-IN-2–treated ( n = 200, kinetochores) oocytes. The signal intensity of BUB3 was normalized with that of CREST. *** P < 0.001. ( G ) USP8 reduces the ubiquitination level of BUB3. Mouse oocytes were injected with the respective cRNAs and maintained for an additional 4 hours in 200 μM IBMX to allow for protein translation. Target proteins were immunoprecipitated using anti-HA beads and analyzed by Western blotting with anti-MYC and anti-HA antibodies. Input oocyte lysates were immunoblotted with an anti-Flag antibody to assess USP8 expression. ( H ) Working model of the mechanism that USP8 governs SAC to ensure oocyte euploidy. In normal oocytes, USP8 maintains BUB3 protein levels through its deubiquitinating activity, thereby sustaining the SAC activity in oocytes and ultimately preserving oocyte ploidy. However, in the absence of USP8, BUB3 is targeted for ubiquitin-mediated proteasomal degradation, leading to SAC inactivation and the production of aneuploid eggs.

Article Snippet: The blots were further blocked in TBST containing 5% low-fat dry milk for 1 hour at room temperature and then incubated with USP8 (1:500; Abclonal, A7031), USP8 (1:500; Proteintech, 67321-1-Ig), Cyclin B1 (1:1000; Cell Signaling Technology, 4135), BUB3 (1:1000; Abcam, ab133699), BUBR1 (1:1000; Abcam, Ab28193), MAD2 (1:1000; Proteintech, 10337-1-AP), CDC20 (1:500; Proteintech, 10252-1-AP), BUB1 (1:1000; Abcam, Ab195268 ), MPS1 (1:500; Proteintech, 10381-1-AP), Flag (1:1000; Sigma-Aldrich, F3165), HA (1:1000; Sigma-Aldrich, H9658), MYC (1:1000; Cell Signaling Technology, 2278), Normal Rabbit IgG (1:1000; Cell Signaling Technology, 2729), or Cofilin (1:5000; Proteintech, 66057-1-Ig) antibodies at 4°C overnight.

Techniques: Reverse Transcription, Real-time Polymerase Chain Reaction, Control, Western Blot, Activity Assay, Fluorescence, Ubiquitin Proteomics, Injection, Immunoprecipitation, Expressing, Preserving