Kong-Kong Wei

Background. Pyroptosis has a dual function in malignant tumor progression and management. The action of pyroptosis-related genes (PRGs) in pancreatic cancer (PC), however, remains uncertain. Methods. Differential expression analyses of 57 PRGs were conducted in the TCGA TARGET GTEx dataset. The candidate genes were determined using LASSO Cox regression and random forest analyses. A risk model was developed with the TCGA dataset and validated with the ICGC dataset. Results. Three prognosis-related PRGs (BAK1, GSDMC, and IL18) were chosen to create a risk model. High-risk patients from the TCGA and ICGC cohorts had an unfavorable overall survival (all ). The risk modelʼs accuracy and independent predictability were assessed by receiver operating characteristic curves and multivariate Cox regression analysis, respectively. High-risk patients possessed different molecular pathways, higher KRAS and TP53 mutations, increased expression of PD-L1, C1 immune subtype, and immunosuppressive microenvironment characterized by parainflammation compared to low-risk patients. KRAS and TP53 mutations participated in different inflammatory pathways and played different prognostic roles between the two risk groups. KRAS mutations in high-risk patients caused a more unfavorable prognosis than wild-type KRAS ( ), whereas TP53 mutations in low-risk patients exhibited a poorer outcome than wild-type TP53 ( ). Spearman correlation analyses revealed that the parainflammatory response in PC might be implicated in GSDMC-mediated pyroptosis via cytosolic DNA-sensing pathways under hypoxic conditions. Furthermore, the risk scores were significantly and positively related to the expression of HNRNPC, RBM15, YTHDF1, and YTHDF2, as well as sensitivity to gemcitabine, cisplatin, and erlotinib. Conclusions. This study created a novel pyroptosis-based risk model related to the parainflammatory immune microenvironment, which might help identify novel biomarkers, evaluate the tumor immune microenvironment, and develop management strategies for PC patients.

The study is aimed at exploring the potential biological process and molecular mechanism of KIF22 involved in the development and progression of pancreatic cancer. First, we used the GEPIA database and tissue qRT‐PCR to examine the expression of KIF22 mRNA in pancreatic cancer. Meanwhile, immunohistochemistry revealed the presence of KIF22 in 71 pancreatic cancer tissues versus 30 paracarcinoma tissues. Then, we also explored the relationship between KIF22 expression level and clinical prognosis. Furthermore, in pancreatic cancer cells, we silenced KIF22 by transfecting KIF22 SiRNA, and we investigated the effect of KIF22 on the proliferation of pancreatic cancer cells with MTT and colony formation assays. Finally, we used Gene Set Enrichment Analysis (GSEA) to look at the effect of KIF22 on the cell cycle regulation of pancreatic cancer cells, and we used Western blot to look at the relationship between KIF22 and the phosphorylated MEK1/2, ERK1/2 (p‐MEK1/2, p‐ERK1/2), and the cyclin‐dependent kinase inhibitor (P21). In this study, we found that KIF22 was highly expressed in pancreatic cancer tissues, and patients with high expression of KIF22 demonstrated significantly worse clinical prognosis outcomes (P < 0.05). When the KIF22 gene was silenced in pancreatic cancer cells (PANC‐1 and MIA PaCa‐2), the cells’ ability to proliferate was significantly reduced. Furthermore, GSEA confirmed that KIF22 is involved in cell cycle regulation in pancreatic cancer patients (FDR = 0.00158, P < 0.0001). Besides, the level of KIF22 expression was positively correlated with Ki67 (r = 0.8043, P < 0.0001), and KIF22 can promote the transmutation of G1/S. The expression of p‐MEK1/2 and p‐ERK1/2 was significantly downregulated, while P21 expression was significantly upregulated (P < 0.05). According to our findings, KIF22 is highly expressed in pancreatic cancer and demonstrates a poor clinical prognosis. It regulates the cell cycle via the MEK/ERK/P21 signaling axis and promotes the development of pancreatic cancer.