Journal: Cancers

Article Title: Optimizing Sequential Targeted Therapies in Advanced Renal Cell Carcinoma Using Patient-Derived Orthotopic Xenograft Mouse Avatars

doi: 10.3390/cancers18101615

Figure Lengend Snippet: Histopathological comparison of tumor architecture and proliferation between patient renal cell carcinoma (RCC) specimens and corresponding patient-derived xenograft models. Formalin-fixed, paraffin-embedded sections from primary patient tumors (KiCa-Pt58 and KiCa-Pt118), matched subcutaneous xenografts, and intra-renal patient-derived orthotopic xenograft (PDOX) tumors were analyzed to assess preservation of tumor histology and proliferative characteristics. ( A , C ) Representative images of KiCa-Pt58 ( A ) and KiCa-Pt118 ( C ) tissues stained with hematoxylin and eosin (H&E) for tissue architecture or were subjected to immunohistochemistry (IHC) for human CD44 (tumor cell marker) and human Ki67 (proliferation marker). Brown staining indicates positive immunoreactivity. Images were captured at 100× original magnification using an Axiovert 200M deconvolution microscope and SlideBook 6.0 software (Intelligent Imaging Innovations, Denver, CO, USA). ( B , D ) Quantitative analysis of Ki67-positive area (%) in KiCa-Pt58 ( B ) and KiCa-Pt118 ( D ) tissues. Positive (brown) staining areas were quantified digitally using Adobe Photoshop 7.0, with the percentage of immunoreactive area calculated per field. Data are presented as mean ± SEM (multiple fields per sample). Comparisons among patient biopsy specimens, subcutaneous xenografts, and orthotopic PDOX tumors were performed using unpaired Student’s t -test. No significant differences were observed (ns, p > 0.05), demonstrating faithful recapitulation of the parental tumor proliferative index across model passages. Abbreviations: RCC, renal cell carcinoma; PDOX, patient-derived orthotopic xenograft; H&E, hematoxylin and eosin; IHC, immunohistochemistry.

Article Snippet: Paraffin-embedded sections (5 μm) were stained with H&E or subjected to immunohistochemistry using primary antibodies against human Ki67 (proliferation marker; Thermo Fisher Scientific, Waltham, MA, USA; 1:200), human CD44 (tumor cell marker; Acris Antibodies, Rockville, MD, USA; 1:75), mouse CD31 (angiogenesis marker; Abcam, Cambridge, MA, USA; 1:200), and human PD-L1 (programmed death-ligand 1, immune checkpoint ligand; BioLegend, San Diego, CA, USA; 1:200) [ ].

Techniques: Comparison, Derivative Assay, Formalin-fixed Paraffin-Embedded, Preserving, Staining, Immunohistochemistry, Marker, Microscopy, Software, Imaging

Journal: Cancers

Article Title: Optimizing Sequential Targeted Therapies in Advanced Renal Cell Carcinoma Using Patient-Derived Orthotopic Xenograft Mouse Avatars

doi: 10.3390/cancers18101615

Figure Lengend Snippet: Histopathological and immunohistochemical evaluation of targeted therapy responses in the KiCa-Pt58 patient-derived orthotopic xenograft (PDOX) model. ( A ) Representative images of left kidney tumors from KiCa-Pt58 PDOX mice after vehicle control or sequential targeted therapy (Everolimus→Sunitinib [E→S], Pazopanib→Sunitinib [P→S], Sunitinib→Everolimus [S→E], Pazopanib→Everolimus [P→E]). Formalin-fixed, paraffin-embedded sections were stained with hematoxylin and eosin (H&E) for tumor architecture or subjected to immunohistochemistry (IHC) for human CD44 (tumor cell marker), human Ki67 (proliferation marker), mouse CD31 (angiogenesis/endothelial marker), and human PD-L1 (immune checkpoint ligand). Brown staining indicates positive immunoreactivity. Images were acquired at 100× original magnification using an Axiovert 200M deconvolution microscope and SlideBook 6.0 software (Intelligent Imaging Innovations, Denver, CO, USA). ( B – D ) Quantitative analysis of positive staining area (%) for Ki67 ( B ), CD31 ( C ), and PD-L1 ( D ) across treatment groups. Positive (brown) areas were quantified digitally using Adobe Photoshop 7.0 (percentage immunoreactive area per field). Data are presented as mean ± SEM (multiple fields per sample; n = 7–9 mice per group). Statistical comparisons vs. control were performed using one-way ANOVA followed by Dunnett’s or Tukey’s post hoc tests (GraphPad Prism v7). Asterisks indicate significance: * p < 0.05; ** p < 0.01; *** p < 0.001. Effective regimens (particularly P→E and S→E) significantly reduced Ki67+ proliferation, CD31+ vascularity, and PD-L1 expression compared to control, consistent with antitumor and potential immunomodulatory effects. Abbreviations: PDOX, patient-derived orthotopic xenograft; IHC, immunohistochemistry; E, everolimus; S, sunitinib; P, pazopanib.

Article Snippet: Paraffin-embedded sections (5 μm) were stained with H&E or subjected to immunohistochemistry using primary antibodies against human Ki67 (proliferation marker; Thermo Fisher Scientific, Waltham, MA, USA; 1:200), human CD44 (tumor cell marker; Acris Antibodies, Rockville, MD, USA; 1:75), mouse CD31 (angiogenesis marker; Abcam, Cambridge, MA, USA; 1:200), and human PD-L1 (programmed death-ligand 1, immune checkpoint ligand; BioLegend, San Diego, CA, USA; 1:200) [ ].

Techniques: Immunohistochemical staining, Derivative Assay, Control, Formalin-fixed Paraffin-Embedded, Staining, Immunohistochemistry, Marker, Microscopy, Software, Imaging, Expressing

Journal: Cancers

Article Title: Optimizing Sequential Targeted Therapies in Advanced Renal Cell Carcinoma Using Patient-Derived Orthotopic Xenograft Mouse Avatars

doi: 10.3390/cancers18101615

Figure Lengend Snippet: Histopathological and immunohistochemical assessment of targeted therapy responses in the KiCa-Pt118 patient-derived orthotopic xenograft (PDOX) model. ( A ) Representative images of left kidney tumors from KiCa-Pt118 PDOX mice after vehicle control or sequential targeted therapy (Everolimus→Sunitinib [E→S], Pazopanib→Sunitinib [P→S], Sunitinib→Everolimus [S→E], Pazopanib→Everolimus [P→E]). Formalin-fixed, paraffin-embedded sections were stained with hematoxylin and eosin (H&E) for tumor architecture or subjected to immunohistochemistry (IHC) for human CD44 (tumor cell marker), human Ki67 (proliferation marker), mouse CD31 (angiogenesis/endothelial marker), and human PD-L1 (immune checkpoint ligand). Brown staining indicates positive immunoreactivity. Images were acquired at 100× original magnification using an Axiovert 200M deconvolution microscope and SlideBook 6.0 software (Intelligent Imaging Innovations, Denver, CO, USA). ( B – D ) Quantitative analysis of positive staining area (%) for Ki67 ( B ), CD31 ( C ), and PD-L1 ( D ) across treatment groups. Positive (brown) areas were quantified digitally using Adobe Photoshop 7.0 (percentage immunoreactive area per field), as described in . Data are presented as mean ± SEM (multiple fields per sample; n = 7–9 mice per group). Statistical comparisons vs. control were performed using one-way ANOVA followed by Dunnett’s or Tukey’s post hoc tests (GraphPad Prism v7). Asterisks indicate significance: * p < 0.05; ** p < 0.01; *** p < 0.001. Effective regimens (particularly S→E) significantly reduced Ki67+ proliferation, CD31+ vascularity, and PD-L1 expression compared to control, consistent with antitumor activity in this indolent, non-metastatic model. Abbreviations: PDOX, patient-derived orthotopic xenograft; IHC, immunohistochemistry; E, everolimus; S, sunitinib; P, pazopanib.

Article Snippet: Paraffin-embedded sections (5 μm) were stained with H&E or subjected to immunohistochemistry using primary antibodies against human Ki67 (proliferation marker; Thermo Fisher Scientific, Waltham, MA, USA; 1:200), human CD44 (tumor cell marker; Acris Antibodies, Rockville, MD, USA; 1:75), mouse CD31 (angiogenesis marker; Abcam, Cambridge, MA, USA; 1:200), and human PD-L1 (programmed death-ligand 1, immune checkpoint ligand; BioLegend, San Diego, CA, USA; 1:200) [ ].

Techniques: Immunohistochemical staining, Derivative Assay, Control, Formalin-fixed Paraffin-Embedded, Staining, Immunohistochemistry, Marker, Microscopy, Software, Imaging, Expressing, Activity Assay