CXCL5 expression in tumor tissues is associated with poor prognosis in patients with pancreatic cancer

Advance in the role of chemokines/chemokine receptors in carcinogenesis: Focus on pancreatic cancer

The chemokines/chemokine receptors pathway significantly influences cell migration, particularly in recruiting immune cells to the tumor microenvironment (TME), impacting tumor progression and treatment outcomes. Emerging research emphasizes the involvement of chemokines in drug resistance across various tumor therapies, including immunotherapy, chemotherapy, and targeted therapy. This review focuses on the role of chemokines/chemokine receptors in pancreatic cancer (PC) development, highlighting their impact on TME remodeling, immunotherapy, and relevant signaling pathways. The unique immunosuppressive microenvironment formed by the interaction of tumor cells, stromal cells and immune cells plays an important role in the tumor proliferation, invasion, migration and therapeutic resistance. Chemokines/chemokine receptors, such as chemokine ligand (CCL) 2, CCL3, CCL5, CCL20, CCL21, C-X-C motif chemokine ligand (CXCL) 1, CXCL2, CXCL3, CXCL4, CXCL5, CXCL8, CXCL9, CXCL10, CXCL11, CXCL12, CXCL13, CXCL14, CXCL16, CXCL17, and C-X3-C motif chemokine ligand (CX3CL)1, derived mainly from leukocyte cells, cancer-related fibroblasts (CAFs), pancreatic stellate cells (PSCs), and tumor-associated macrophages (TAMs), contribute to PC progression and treatment resistance. Chemokines recruit myeloid-derived suppressor cells (MDSC), regulatory T cells (Tregs), and M2 macrophages, inhibiting the anti-tumor activity of immune cells. Simultaneously, they enhance pathways like epithelial-mesenchymal transition (EMT), Akt serine/threonine kinase (AKT), extracellular regulated protein kinases (ERK) 1/2, and nuclear factor kappa-B (NF-κB), etc., elevating the risk of PC metastasis and compromising the efficacy of radiotherapy, chemotherapy, and anti-PD-1/PD-L1 immunotherapy. Notably, the CCLx-CCR2 and CXCLx-CXCR2/4 axis emerge as potential therapeutic targets in PC. This review integrates recent findings on chemokines and receptors in PC treatment, offering valuable insights for innovative therapeutic approaches.

Targeting CXCL5 in Pancreatic Cancer Cells Inhibits Cancer Xenograft Growth by Reducing Proliferation and Inhibiting EMT Progression

BACKGROUND

Pancreatic cancer (PC) is the most lethal malignant tumor, with average survival period of about 10 months. C-X-C ligand 5 (CXCL5), an important chemokine for immune cell accumulation in tumor tissues, has been reported to be involved in a variety of human cancers. However, the exact role of CXCL5 in PC progression has not been well defined.

METHODS

The expression of CXCL5 in PC was analyzed based on online databases and clinical specimens immunohistochemical staining, and Western blotting of CXCL5 in PC cell lines and patient samples. The correlation between CXCL5 expression and prognosis in PC was explored. The role of CXCL5 in PC was investigated through in vitro and in vivo experiments.

RESULTS

The expression of CXCL5 was significantly increased in PC tissues compared with that in pancreas tissues, and CXCL5 high expression predicts poor prognosis in PC patients. Further analyses demonstrated that overexpression of CXCL5 in PC cells was positively related to higher proliferation rate, higher migration ability, and higher EMT markers including SNAI2 and TWIST1 of tumor cells in vitro. Consistently, the knockdown of CXCL5 in PC cells harmed the proliferation rate, migration ability, and expression of EMT indexes of tumor cells in vitro. Importantly, knockdown of CXCL5 inhibited the growth of xenograft tumors in vivo.

CONCLUSION

CXCL5 high expression predicts poor prognosis in PC patients. CXCL5 promotes PC cell growth and EMT process. Inhibition of CXCL5 may be a potential therapeutic approach for PC.

Differential expression profile of CXC-receptor-2 ligands as potential biomarkers in pancreatic ductal adenocarcinoma

The discovery of early detection markers of pancreatic cancer (PC) disease is highly warranted. We analyzed the expression profile of different CXC-receptor-2 (CXCR2) ligands in PC cases for the potential of biomarker candidates. Analysis of different PDAC microarray datasets with matched normal and pancreatic tumor samples and next-generation sequenced transcriptomics data using an online portal showed significantly high expression of CXCL-1, 3, 5, 6, 8 in the tumors of PC patients. High CXCL5 expression was correlated to poor PC patient survival. Interestingly, mRNA and protein expression analysis of human PC cell lines showed higher CXCL2, 3, and 5 expressions in cell lines derived from metastatic sites than primary tumors. Furthermore, we utilized immunohistochemistry (IHC) to evaluate the expression of CXCR2 ligands in the human PC tumors and observed positive staining for CXCL1, 3, and 8 with a higher average IHC composite score of CXCL3 in the PC tissue specimens than the normal pancreas. We also observed an increase in the expression of mouse CXCL1, 3, and 5 in the pre-cancerous lesions of tumors and metastasis tissues derived from the PDX-cre-LSL-Kras^G12D mouse model. Together, our data suggest that different CXCR2 ligands show the potential of being utilized as a diagnostic biomarker in PC patients.

Prognostic Biomarkers and Immunotherapeutic Targets Among CXC Chemokines in Pancreatic Adenocarcinoma

Background

Pancreatic cancer is one of the principal causes of tumor-related death worldwide. CXC chemokines, a subfamily of functional chemotactic peptides, affect the initiation of tumor cells and clinical outcomes in several human malignant tumors. However, the specific biological functions and clinical significance of CXC chemokines in pancreatic cancer have not been clarified.

Methods

Bioinformatics analysis tools and databases, including ONCOMINE, GEPIA2, the Human Protein Atlas, DAVID, GeneMANIA, cBioPortal, STRING, DGidb, MethSurv, TRRUST, SurvExpress, SurvivalMeth, and TIMER, were utilized to clarify the clinical significance and biological functions of CXC chemokine in pancreatic cancer.

Results

Except for CXCL11/12, the transcriptional levels of other CXC chemokines in PAAD tissues were significantly elevated, and the expression level of CXCL16 was the highest among these CXC chemokines. Our findings also suggested that all of the CXC chemokines were linked to tumor-immune dysfunction involving the abundance of immune cell infiltration, and the Cox proportional hazard model confirmed that dendritic and CXCL3/5/7/8/11/17 were significantly associated with the clinical outcome of PAAD patients. Furthermore, increasing expressions of CXCL5/9/10/11/17 were related to unfavorable overall survival (OS), and only CXCL17 was a prognostic factor for disease-free survival (DFS) in PAAD patients. The expression pattern and prognostic power of CXC chemokines were further validated in the independent GSE62452 dataset. For the prognostic value of single CpG of DNA methylation of CXC chemokines in patients with PAAD, we identified 3 CpGs of CXCL1, 2 CpGs of CXCL2, 2 CpGs of CXCL3, 3 CpGs of CXCL4, 10 CpGs of CXCL5, 1 CpG of CXCL6, 1 CpG of CXCL7, 3 CpGs of CXCL12, 3 CpGs of CXCL14, and 5 CpGs of CXCL17 that were significantly associated with prognosis in PAAD patients. Moreover, the prognostic value of CXC chemokine signature in PAAD was explored and tested in two independent cohort, and results indicated that the patients in the low-risk group had a better OS compared with the high-risk group. Survival analysis of the DNA methylation of CXC chemokine signature demonstrated that PAAD patients in the high-risk group had longer survival times.

Conclusions

These findings reveal the novel insights into CXC chemokine expression and their biological functions in the pancreatic cancers, which might serve as accurate prognostic biomarkers and suitable immunotherapeutic targets for patients with pancreatic cancer.