Panoply™ Human CXCR1 Over-expressing Stable Cell Line

Chemokines and their receptors play a key role in tumor development and progression. In prostate cancer (PCa), interleukin-8 (IL-8/CXCL8) has been shown to promote angiogenesis, proliferation, and metastasis. CXCL8 activates two receptors: CXCR1 and CXCR2. While CXCR2 expression has been shown to promote PCa growth and metastasis, the role of CXCR1 remains unclear. Here, researchers stably expressed CXCR1 and CXCR2 (as a control) in the androgen-dependent PCa cell line MDA-PCa-2b to evaluate the role of CXCR1 in tumor development. Results showed that CXCR1-overexpressing MDA-PCa-2b cells exhibited reduced cell migration, protein kinase B (AKT) activation, prostate-specific antigen (PSA) expression, cell proliferation, and tumor formation in nude mice compared to control cells. CXCR1-overexpressing MDA-PCa-2b cells also exhibited a significant shift toward a mesenchymal phenotype, characterized by decreased E-cadherin expression and corresponding increases in N-cadherin and vimentin expression. RNA-seq and Western blot analysis revealed significantly increased expression of the tumor suppressor integral membrane protein 2A (ITM2A) in CXCR1-overexpressing MDA-PCa-2b cells compared with control cells. ITM2A expression was also downregulated in prostate adenocarcinoma tissue relative to normal prostate tissue. Interestingly, overexpression of ITM2A in MDA-PCa-2b cells inhibited tumor growth similarly to that observed in CXCR1-overexpressing MDA-PCa-2b cells. Taken together, these data suggest that CXCR1 expression in MDA-PCa-2b cells may upregulate ITM2A, thereby suppressing tumor progression.

Here, researchers used the MTT assay to assess the effects of CXCR1 and CXCR2 overexpression on cell proliferation. As shown in Figure 1A, CXCR2-overexpressing MDA-PCa-2b cells proliferated faster than cells expressing vector alone (MDA-PCa-2b-vec). However, CXCR1-overexpressing MDA-PCa-2b cells exhibited significantly decreased proliferation compared to MDA-PCa-2b-Vec (Figure 1A). CXCR1-overexpressing MDA-PCa-2b cells also exhibited a higher apoptotic index compared to control MDA-PCa-2b-Vec and MDA-PCa-2b-CXCR2 cells, although the differences were not significant. Nude mice xenografts were used to assess the effects of CXCR1 and CXCR2 receptor overexpression on MDA-PCa-2b tumor formation in vivo. Six- to eight-week-old nude mice were injected with CXCR1-overexpressing MDA-PCa-2b cells, CXCR2-overexpressing MDA-PCa-2b cells, or control cells. Following subcutaneous injection of cells, the animals were monitored for 10 weeks for the growth of ectopic tumors. As shown in Figure 1, CXCR1-overexpressing MDA-PCa-2b cells formed smaller tumors compared to the control MDA-PCa-2b-Vec cells. However, tumors formed by CXCR2-overexpressing MDA-PCa-2b cells were significantly larger than those formed by the control MDA-PCa-2b-Vec cells (Figures 1B-D).

Figure 1. Effect of CXCR1 and CXCR2 overexpression on in vitro and in vivo growth of MDA-PCa-2b cells. (Adekoya T O, et al., 2024)