Novel lactylation-related signature to predict prognosis for pancreatic adenocarcinoma

BACKGROUND Lactate,previously considered a metabolic byproduct,is pivotal in cancer progression and maintaining the immunosuppressive tumor microenvironment.Further investigations confirmed that lactate is a primary regulator,introducing recently described post-translational modifications of histone and non-histone proteins,termed lysine lactylation.Pancreatic adenocarcinomas are characterized by increased glycolysis and lactate accumulation.However,our understanding of lactylation-related genes in pancreatic adenocarcinomas remains limited.AIM To construct a novel lactylation-related gene signature to predict the survival of patients with pancreatic cancer.METHODS RNA-seq and clinical data of pancreatic adenocarcinoma(PDAC)were obtained from the GTEx(Genotype-Tissue Expression)and TCGA(The Cancer Genome Atlas)databases via Xena Explorer,and GSE62452 datasets from GEO.Data on lactylation-related genes were obtained from publicly available sources.Differential expressed genes(DEGs)were acquired by using R package“DESeq2”in R.Univariate COX regression analysis,LASSO Cox and multivariate Cox regressions were produced to construct the lactylation-related prognostic model.Further analyses,including functional enrichment,ESTIMATE,and CIBERSORT,were performed to analyze immune status and treatment responses in patients with pancreatic cancer.PDAC and normal human cell lines were subjected to western blot analysis under lactic acid intervention;two PDAC cell lines with the most pronounced lactylation were selected.Subsequently,RT-PCR was employed to assess the expression of LRGs genes;SLC16A1,which showed the highest expression,was selected for further investigation.SLC16A1-mediated lactylation was analyzed by immunofluorescence,lactate production analysis,colony formation,transwell,and wound healing assays to investigate its role in promoting the proliferation and migration of PDAC cells.In vivo validation was performed using an established tumor model.RESULTS In this study,we successfully identified 10 differentially expressed lactylation-related genes(LRGs)with prognostic value.Subsequently,a lactylation-related signature was developed based on five OS-related lactylationrelated genes(SLC16A1,HLA-DRB1,KCNN4,KIF23,and HPDL)using Lasso Cox hazard regression analysis.Subsequently,we evaluated the clinical significance of the lactylation-related genes in pancreatic adenocarcinoma.A comprehensive examination of infiltrating immune cells and tumor mutation burden was conducted across different subgroups.Furthermore,we demonstrated that SLC16A1 modulates lactylation in pancreatic cancer cells through lactate transport.Both in vivo and in vitro experiments showed that decreasing SLC16A1 Level and its lactylation significantly inhibited tumor progression,indicating the potential of targeting the SLC16A1/Lactylation-associated signaling pathway as a therapeutic strategy against pancreatic adenocarcinoma.CONCLUSION We constructed a novel lactylation-related prognostic signature to predict OS,immune status,and treatment response of patients with pancreatic adenocarcinoma,providing new strategic directions and antitumor immunotherapies.

Cd Se/Zn S quantum dots induce photodynamic effects and cytotoxicity in pancreatic cancer cells

AIM: To investigate the photodynamic effect of Cd Se/Zn S quantum dots(QDs) on pancreatic cancer cells and elucidate the probable mechanisms.METHODS: The pancreatic cancer cell line SW1990 was treated with different concentrations of Cd Se/Zn S QDs(0, 0.5, 1.0, 1.5, 2.0, 2.5 μmol/L), with or without illumination. The viability of SW1990 cells was tested using the Cell Counting Kit-8(CCK-8) assay. The ultrastructural changes of SW1990 cells were observed by transmission electron microscopy. Apoptosis was detected by nuclear staining and flow cytometry(FCM). Reactive oxygen species(ROS) were measured by dichlorofluorescein diacetate via fluorescence microscopy. Expression of Bax, Bcl-2 and caspase-3 was measured by real-time polymerase chain reaction(PCR) and protein immunoblotting 24 h after SW1990 cells were treated with Cd Se/Zn S QDs and illuminated.RESULTS: The CCK-8 assay results showed that both Cd Se/Zn S QDs with and without illumination suppressed SW1990 cell proliferation. Cell viability was significantly lower when illuminated or with a longer incubation time and a higher light dose. Cd Se/Zn S QDs with illumination caused ultrastructural changes in SW1990 cells, such as organelle degeneration and chromatin condensation and aggregation at the periphery of the nucleus. Fluorescence microscopy and FCM showed that Cd Se/Zn S QDs(1.5 μmol/L) with illumination increased SW1990 cell apoptosis(53.2%) and ROS generation compared with no illumination. Real-time PCR showed that expression of Bax and caspase-3 was upregulated and Bcl-2 was downregulated. Immunoblotting results were consistent with real-time PCR results. Inhibition of ROS and apoptosis both attenuated QD-photodynamictherapy-induced cell death.CONCLUSION: Cd Se/Zn S QDs can be used as a photosensitizer to inhibit SW1990 cell proliferation through ROS generation and apoptotic protein expression regulation.