Journal: Translational Oncology

Article Title: Inhibition of PTCH1 drug efflux activity enhances chemotherapy efficacy against triple negative breast cancers

doi: 10.1016/j.tranon.2026.102777

Figure Lengend Snippet: Ptch1 is expressed in breast cancer cell lines. A. PTCH1 mRNA expression (log 2 transformed) in various luminal and HER2 breast cancer cell lines (dark green) and in TNBC cell lines (other colors). TNBC cell lines are depicted according to the “Lehmann TNBC subtype” nomenclature : basal-like 1 (yellow), basal-like 2 (pale green), immunomodulatory (brown), luminal androgen receptor (dark pink), mesenchymal (pale pink) and mesenchymal stem-like (pink). B. PTCH1 protein expression in three TNBC cell lines. Western-blot was performed on 50 µg extracts from TNBC cell lines (MDA-MB-231, HCC-38 and MDA-MB-468) with antibodies directed against PTCH1. PTCH1 and GAPDH signals were quantified using ImageJ software. Data presented are the mean ± SEM of at least 3 independent experiments. Significance is calculated using Oneway ANOVA Turkey’s multiple comparisons test and attained at P < 0.05 (*).

Article Snippet: Human breast cancer cell lines MDA-MB-231, MDA-MB-468 and HCC-38 were purchased from ATCC.

Techniques: Expressing, Transformation Assay, Western Blot, Software

Journal: Translational Oncology

Article Title: Inhibition of PTCH1 drug efflux activity enhances chemotherapy efficacy against triple negative breast cancers

doi: 10.1016/j.tranon.2026.102777

Figure Lengend Snippet: PTCH1 drug efflux inhibitor PAH increases the sensitivity of TNBC cells to chemotherapy . Cell viability was measured after 24 h or 48 h treatment with increasing concentration of docetaxel or doxorubicin respectively on MDA-MB-231, MDA-MB-468 and HCC-38 cell lines in the absence or the presence of 15µM PAH. IC 50 values (corresponding to the concentration of chemotherapy inducing 50% of cell death) were calculated. Data reported are the mean ± SEM of at least 3 independent experiments. Significance is attained at P < 0.05 (*).

Article Snippet: Human breast cancer cell lines MDA-MB-231, MDA-MB-468 and HCC-38 were purchased from ATCC.

Techniques: Concentration Assay

Journal: Translational Oncology

Article Title: Inhibition of PTCH1 drug efflux activity enhances chemotherapy efficacy against triple negative breast cancers

doi: 10.1016/j.tranon.2026.102777

Figure Lengend Snippet: Other multidrug transporters are expressed in TNBC cell lines. A. P-gp and ABCG2 protein expression in three TNBC cell lines. Western-blot was performed on 50 µg extracts from each TNBC cell line (MDA-MB-231, HCC-38 and MDA-MB-468) with antibodies directed against P-gp or ABCG2 and GAPDH. B. P-gp, ABCG2 and GAPDH signals were quantified using ImageJ software. Data presented are the mean ± SEM of at least 3 independent experiments. Significance is calculated using Oneway ANOVA Turkey’s multiple comparisons test and attained at P < 0.05 (*). ** P < 0.01; *** P < 0.001; ns P > 0.05.

Article Snippet: Human breast cancer cell lines MDA-MB-231, MDA-MB-468 and HCC-38 were purchased from ATCC.

Techniques: Expressing, Western Blot, Software

Journal: Translational Oncology

Article Title: Inhibition of PTCH1 drug efflux activity enhances chemotherapy efficacy against triple negative breast cancers

doi: 10.1016/j.tranon.2026.102777

Figure Lengend Snippet: PAH increases docetaxel efficacy against TNBC spheroids. MDA-MB-231 cells were plated in ultra-low attachment surface 24 well plates in complete medium and treated with increasing concentrations of docetaxel in the presence of DMSO (control, 0 PAH), PAH 10 µM or 30 µM. After 2 weeks pictures were taken using Cytation 5 cell imaging system from Biotek. The surface of spheroids was calculated and reported after normalization on the condition without docetaxel for each concentration of PAH.

Article Snippet: Human breast cancer cell lines MDA-MB-231, MDA-MB-468 and HCC-38 were purchased from ATCC.

Techniques: Control, Imaging, Concentration Assay

Journal: Translational Oncology

Article Title: Inhibition of PTCH1 drug efflux activity enhances chemotherapy efficacy against triple negative breast cancers

doi: 10.1016/j.tranon.2026.102777

Figure Lengend Snippet: PAH addition to chemotherapy inhibits migration of TNBC cells. A. 100000 cells were seeded on membrane from Transwell plates. Cells were treated 24 h with doxorubicin ± 15µM PAH or 48 h with docetaxel ± 15µM PAH. After fixation and staining with crystal violet, wells were observed on a microscope with X5 objective. B. Migration was measured using a wound-healing assay. A wound was performed on MDA-MB-231 confluent cells seeded in 24 well plates. The medium was replaced by fresh medium containing 5 µM docetaxel in the absence of PAH, or the presence of 5 µM PAH. Two pictures were taken at two different points of each well immediately after wound, and 3 days after wound with 5X objective. The width of the wound was measured using ImageJ software and reported as final wound width/initial wound width in percentage. Data presented are the mean ± SEM of 3 independent experiments. Significance is attained at P < 0.05.

Article Snippet: Human breast cancer cell lines MDA-MB-231, MDA-MB-468 and HCC-38 were purchased from ATCC.

Techniques: Migration, Membrane, Staining, Microscopy, Wound Healing Assay, Software

Journal: Translational Oncology

Article Title: Inhibition of PTCH1 drug efflux activity enhances chemotherapy efficacy against triple negative breast cancers

doi: 10.1016/j.tranon.2026.102777

Figure Lengend Snippet: PTCH1 contributes to the efflux of doxorubicin from TNBC cells. A. PTCH1 protein expression (left panel) and intracellular doxorubicin (right panel) were analyzed 16 h after transfection of MDA-MB-231 cells with PTCH1-siRNA or negative-control-siRNA. PTCH1 and GAPDH western blot signals were quantified using ImageJ software (left panel). For doxorubicin accumulation measurements (right panel), MDA-MB-231 cells were grown on slides and transfected with PTCH1-siRNA or negative-control-siRNA. After incubation with 10 µM doxorubicin, 3 coverslips were fixed for doxorubicin loading control; the other coverslips were incubated with efflux buffer and fixed. B. Docetaxel inhibits the accumulation of doxorubicin in MDA-MB-231 cells. Cells on coverslip were incubated with 10 µM doxorubicin or 10 µM doxorubicin and 50 µM docetaxel. Doxorubicin fluorescence images were acquired by epifluorescence microscopy using a 40X objective, and doxorubicin fluorescence was quantified using ImageJ software for about 100 cells per condition per experiment. Histograms are the mean ± SEM of 3 independent experiments. Significance is attained at P < 0.05.

Article Snippet: Human breast cancer cell lines MDA-MB-231, MDA-MB-468 and HCC-38 were purchased from ATCC.

Techniques: Expressing, Transfection, Negative Control, Western Blot, Software, Incubation, Control, Fluorescence, Epifluorescence Microscopy

Journal: bioRxiv

Article Title: ARHGEF7 S-glutathionylation promotes cancer cell migration through Rac1 activation

doi: 10.64898/2026.05.01.722049

Figure Lengend Snippet: ( a ) ARHGEF7 (human isoform-a, 646 residues, NM_001113513) domains, structure, and selected residues. The structure is an AlphaFold model (AF-Q14155-1-F1-model_v6_isoform_a) of ARHGEF7 showing the structured SH3, DH, and PH domains with cysteines and nearby residues. ( b ) Accessible surface areas (ASA) of cysteines in ARHGEF7. ( c ) Sequence alignments around C312 in ARHGEF7 orthologs. ( d ) Clickable glutathione approach. Cells expressing a glutathione synthetase mutant (GS M4) synthesize and produce clickable glutathione (N 3 -GSH) using endogenous γGlu-Cys and exogenous azido-Ala. Clickable glutathione forms S-glutathionylation with proteins, which are analyzed after click reactions. ( e - f ) Glutathionylation of ARHGEF7 WT and cysteine mutants in MDA-MB-231 cells in response to high glucose (HG, 25 mM) or low glucose (LG, 5 mM) conditions: cells were incubated for 20 h (n=3). ( g - h ) Glutathionylation of ARHGEF7 constructs in MDA-MB-231 cells upon adding EGF (n=3). EGF was incubated for 20 h. The lysates were used for click reactions with biotin-alkyne and analyzed by western blot with FLAG antibody before (input) and after (eluted) pull-down with streptavidin-agarose. Data represent the mean ± SD. The statistical difference was analyzed by one-way ANOVA and Tukey’s post-hoc test ( e - h ), where *p < 0.03, **p < 0.002, ***p < 0.0002, ****p < 0.0001.

Article Snippet: Breast cancer cell line MDA-MB-231 (ATCC, HTB-26TM) and breast cancer cell line MDA-MB-468 (ATCC, HTB-132TM) were maintained in Dulbecco’s Modified Eagle Medium with high glucose (DMEM, Cytiva, HycloneTM) supplemented with 10% Fetal Bovine Serum (FBS, Cytiva, HycloneTM) and 1% (100 U/mL) Penicillin-Streptomycin (Pen-strep, Thermo Scientific) in a humified incubator at 37°C in a 5% CO 2 environment.

Techniques: Sequencing, Expressing, Mutagenesis, Incubation, Construct, Western Blot

Journal: bioRxiv

Article Title: ARHGEF7 S-glutathionylation promotes cancer cell migration through Rac1 activation

doi: 10.64898/2026.05.01.722049

Figure Lengend Snippet: ( a - b ) In-vitro scratch migration analysis of MDA-MB-231 cells expressing ARHGEF7 construct in high glucose (HG, 25 mM) or low glucose (LG, 5 mM) conditions (n=4) ( a ) or in response to EGF (n=9) ( b ). Yellow indicates areas without cells. ( c - d ) Transwell invasion analysis of MDA-MB-231 cells expressing ARHGEF7 constructs in HL or LG (n=3) ( c ) or upon incubating EGF (n=3) ( d ). Cells were incubated in HG or LG ( a , c ) or with EGF for 20 h ( b , d ). A scale bar = 500 μm. Data represent the mean ± SD. The statistical difference was analyzed by two-way ANOVA and Tukey’s post-hoc test ( a - d ), where *p < 0.03, **p < 0.002, ***p < 0.0002, ****p < 0.0001.

Article Snippet: Breast cancer cell line MDA-MB-231 (ATCC, HTB-26TM) and breast cancer cell line MDA-MB-468 (ATCC, HTB-132TM) were maintained in Dulbecco’s Modified Eagle Medium with high glucose (DMEM, Cytiva, HycloneTM) supplemented with 10% Fetal Bovine Serum (FBS, Cytiva, HycloneTM) and 1% (100 U/mL) Penicillin-Streptomycin (Pen-strep, Thermo Scientific) in a humified incubator at 37°C in a 5% CO 2 environment.

Techniques: In Vitro, Migration, Expressing, Construct, Incubation

Journal: bioRxiv

Article Title: ARHGEF7 S-glutathionylation promotes cancer cell migration through Rac1 activation

doi: 10.64898/2026.05.01.722049

Figure Lengend Snippet: Analysis of ARHGEF7 protein interactions and Rac1-PAK1 downstream signaling. MDA-MB-231 cells expressing ARHGEF7 WT or C312S were incubated in high glucose (HG, 25 mM) or low glucose (LG, 5 mM) for 20 h. ( a ) ARHGEF7 S-glutathionylation increases its binding to Rac1. ARHGEF7 co-immunoprecipitation (co-IP) with Rac1 and PAK1 (n=3). ( b ) Rac1 is activated upon ARHGEF7 S-glutathionylation. Active Rac1 was enriched by purified GST-PBD (p21-binding domain derived from PAK1) and analyzed by western blots (n=3). ( c ) ARHGEF7 S-glutathionylation activates PAK1 and its downstream signaling. Phosphorylation levels of PAK1, LIMK1, and MEK1/2 were analyzed by western blot (n=3). ( d ) ARHGEF7 S-glutathionylation increases Rac1 localization at the cell periphery. The co-localization images of ARHGEF7 and Rac1 (left). Cells were fixed and analyzed by antibodies to FLAG (green) and Rac1/Cdc42 (red) (n=10 images). White arrows indicate the intense co-localization of ARHGEF7 and Rac1. Pearson’s correlation coefficients (right) were calculated after Intermodes thresholding to select for colocalization of ARHGEF7 and Rac1 at the cell periphery (see also Figure S6). A scale bar = 10 μm. Data represent the mean ± SD. The statistical difference was analyzed by one-way ANOVA and Tukey’s post-hoc test ( a-d ), where *p < 0.03, **p < 0.002, ***p < 0.0002, ****p < 0.0001.

Article Snippet: Breast cancer cell line MDA-MB-231 (ATCC, HTB-26TM) and breast cancer cell line MDA-MB-468 (ATCC, HTB-132TM) were maintained in Dulbecco’s Modified Eagle Medium with high glucose (DMEM, Cytiva, HycloneTM) supplemented with 10% Fetal Bovine Serum (FBS, Cytiva, HycloneTM) and 1% (100 U/mL) Penicillin-Streptomycin (Pen-strep, Thermo Scientific) in a humified incubator at 37°C in a 5% CO 2 environment.

Techniques: Expressing, Incubation, Binding Assay, Immunoprecipitation, Co-Immunoprecipitation Assay, Purification, Derivative Assay, Western Blot, Phospho-proteomics