Identification of PANoptosis-related signature reveals immune infiltration characteristics and immunotherapy responses for renal cell carcinoma

Abstract

PANoptosis is a specific type of inflammatory programmed cell death (PCD) modality that can be involved in three key modes of cellular programmed cell death-pyroptosis, apoptosis and necroptosis. We analyzed PANoptosis activity in three common renal cell carcinoma subtypes (Clear cell renal cell carcinoma, Papillary renal cell carcinoma, and Chromophobe renal cell carcinoma) separately and constructed a new PANoptosis immunity index (PANII). In three renal cell carcinomas, we found that PANII was an effective predictor of immunotherapy efficacy in KIRC, KIRP and KICH, and the high PANII group was characterized by high immune infiltration and sensitivity to immunotherapy, while the low PANII group was prone to immune escape and immunotherapy resistance. We performed molecular docking prediction of each core protein comprising PANII and identified natural small molecule compounds with the highest affinity to target proteins. In addition, we found that down-regulation of PYCARD inhibited the proliferation and migration of renal clear cell carcinoma cells by in vitro functional assays, suggesting that PYCARD could be a novel target for renal clear cell carcinoma therapy. Our findings that the PANoptosis characterization-based index (PANII) helps to elucidate the tumor microenvironmental features of three common renal cell carcinoma subtypes and identify patient populations that will benefit from immunotherapy, providing a new tool for the clinical diagnosis and treatment of patients with intermediate- and advanced-stage renal cell carcinoma.

Keywords: Chromophobe renal cell carcinoma; Clear cell renal cell carcinoma; Immunotherapy; PANoptosis; Papillary renal cell carcinoma; Tumor microenvironment.

Fig. 1

PANoptosis pattern analysis of three renal cell carcinoma subtypes. KIRC (A), KIRP (B) and KICH (C) Tumor tissues and normal renal tissues were enriched in Pyroptosis, Apoptosis and Necrotic cell death pathway enrichment results. (D) Crosstalk of key regulatory genes for Apoptosis, Pyroptosis and Necroptosis. (E) PPI network of PANoptosis core-associated genes

Fig. 2

Cluster analysis of PANoptosis patterns. (A-C) Unsupervised cluster analysis of KIRC, KIRP and KICH. (D-F) Kaplan-Meier survival curves between different Clusters in KIRC, KIRP and KICH. (G-I) Differences in immunity scores and stromal scores between Clusters in KIRC, KIRP and KICH. (J-L) Differences in infiltration abundance of immune cells between different Clusters in KIRC, KIRP and KICH. Note * p < 0.05, **p < 0.01, ***p < 0.001

Fig. 3

Enrichment analysis and immunological characterization of different PANII groups. GSEA analysis of high PANII groups in KIRC (A), KIRP (B) and KICH (C). Differences in TumorPurity, ImmuneScore, StromalScore and ESTIMATEScore between high/low PANII groups in KIRC (D), KIRP (E) and KICH (F). Differences in immune cells and immune function between patients in the high/low PANII groups in KIRC (G), KIRP (H), and KICH (I). Pathologic sections showing the level of immune cell infiltration in the high/low PANII groups in KIRC (J), KIRP (K) and KICH (L). Note * p < 0.05, **p < 0.01, ***p < 0.001

Fig. 4

Association of PANII with immunotherapy outcome. (A-C) Differences in common immune checkpoint expression between patients in high/low PANII groups in KIRC, KIRP, and KICH. Differences in TMB levels (D-F) and MSI levels (G-I) between patients in high/low PANII groups in KIRC, KIRP, and KICH. (J-L) Differences in TIDE and Exclusion levels between patients in high/low PANII groups in KIRC, KIRP and KICH. (M-O) IPS scores for anti-PD1(-)CTLA4(-), anti-PD1(+)CTLA4(-), anti-PD1(-)CTLA4(+), and anti-PD1(+)CTLA4(+) blocker ground IPS scores for the high and low PANII groups in KIRC, KIRP, and KICH

Fig. 5

Molecular docking. Screening of candidate small molecules for target proteins using molecular docking. The figure shows the docking poses of the BAX active pocket with Allantoic Acid (A), Chalcomoracin (B), Nadide (C), and Triphosphopyridine Nucleotide (D). CASP1 active pocket with Biliverdin (E), Epicatechin ( F), Epigallocatechin (G), and Glutathione (H). docking poses of CASP8 active pocket with Abrine (I), Citrulline (J), Indicaxanthin (K), and Stachyose (L). docking poses of PYCARD active pocket with Heliosin (M), Laminaran (N), Nadide (O) and Oroxin B (P) in docking poses

Fig. 6

Knockdown of PYCARD inhibits renal clear cell carcinoma cell proliferation and migration. (A-B) QPCR verified the mRNA expression level of PYCARD in 769-P and 786-O cells after transfection with siRNA. CCK8 experiments(C-D), Plate cloning assay (E-F), Transwell cell migration ability (G-H) and Wound-healing assay (I-J) of normal renal tissues and 769-P and 786-O cells after transfection with si-PYCARD. Note * p < 0.05, **p < 0.01, ***p < 0.001