u-PAR expression in cancer associated fibroblast: new acquisitions in multiple myeloma progression.

BACKGROUND: Multiple Myeloma (MM) is a B-cell malignancy in which clonal plasma cells progressively expand within the bone marrow (BM) as effect of complex interactions with extracellular matrix and a number of microenvironmental cells. Among these, cancer-associated fibroblasts (CAF) mediate crucial reciprocal signals with MM cells and are associated to aggressive disease and poor prognosis. A large body of evidence emphasizes the role of the urokinase plasminogen activator (u-PA) and its receptor u-PAR in potentiating the invasion capacity of tumor plasma cells, but little is known about their role in the biology of MM CAF. In this study, we investigated the u-PA/u-PAR axis in MM-associated fibroblasts and explore additional mechanisms of tumor/stroma interplay in MM progression. METHODS: CAF were purified from total BM stromal fraction of 64 patients including monoclonal gammopathy of undetermined significance, asymptomatic and symptomatic MM, as well as MM in post-treatment remission. Flow cytometry, Real Time PCR and immunofluorescence were performed to investigate the u-PA/u-PAR system in relation to the level of activation of CAF at different stages of the disease. Moreover, proliferation and invasion assays coupled with silencing experiments were used to prove, at functional level, the function of u-PAR in CAF. RESULTS: We found higher activation level, along with increased expression of pro-invasive molecules, including u-PA, u-PAR and metalloproteinases, in CAF from patients with symptomatic MM compared to the others stages of the disease. Consistently, CAF from active MM as well as U266 cell line under the influence of medium conditioned by active MM CAF, display higher proliferative rate and invasion potential, which were significantly restrained by u-PAR gene expression inhibition. CONCLUSIONS: Our data suggest that the stimulation of u-PA/u-PAR system contributes to the activated phenotype and function of CAF during MM progression, providing a biological rationale for future targeted therapies against MM.

SNAI2 enhances HPV­negative cervical cancer cell dormancy by modulating u­PAR expression and the activity of the ERK/p38 signaling pathway in vitro.

The prognosis of patients with human papillomavirus (HPV)­negative cervical cancer is significantly worse than that of patients with HPV­positive cervical cancer. Understanding the mechanisms of this is crucial for preventing disease evolution. In the present study, the GV367­snail family transcriptional repressor 2 (SNAI2) lentiviral vector was constructed and transduced into C­33A cells. Subsequently, the proliferation of tumor cells was detected using the Cell Counting Kit (CCK)­8 method. Flow cytometry was used to analyze the cell cycle progression of tumor cells. The glucose consumption of tumor cells was detected using an oxidase assay, and the senescence of tumor cells was detected using beta­galactosidase staining. The gene expression and the activity of p38 and ERK1/2 were detected using reverse transcription­quantitative PCR and western blotting, respectively. The C­33A­SNAI2 cell line was successfully established. Compared with HeLa and C­33A­Wild cells, the proliferation and percentage of G0/G1­phase cells in the C­33A­SNAI2 group were decreased, as detected by the CCK­8 assay (100±0 vs. 239.1±58.3 vs. 39.7±20.1, P<0.01) and flow cytometry (34.0±7.1% vs. 46.2±10.6% vs. 61.3±5.3%, P<0.05). Compared with the HeLa group, the glucose consumption of the C­33A­Wild and C­33A­SNAI2 groups was significantly decreased (P<0.01). The results of beta­galactosidase staining showed that the proportion of beta­galactosidase­positive cells in the C­33A­SNAI2 group was significantly decreased compared with the C­33A­Wild group (P<0.01). Upregulation of SNAI2 enhanced the increase in p21 expression, and the decrease in CDK1, urokinase plasminogen activator receptor (u­PAR) and cyclin D1 expression in C­33A cells compared with C­33A­Wild cells (P<0.05). In addition, the activities of p38, ERK1/2 and the phosphorylated (p)­ERK1/2/p­p38 ratio were decreased in the C­33A­SNAI2 group compared with the C­33A­Wild and HeLa groups (P<0.05). In conclusion, SNAI2 enhanced HPV­negative cervical cancer C­33A cell dormancy, which was characterized by G0/G1 arrest, by the downregulation of u­PAR expression, and a decrease in the activity of the p­ERK1/2 and p­p38MAPK signaling pathways in vitro. Cancer recurrence and metastases are responsible for most cancer­related deaths. Given that SNAI2 is required for enhancing HPV­negative cervical cancer cell dormancy, regulating this process may promote cervical tumor cells to enter a continuous dormant state, which could be a potential approach for tumor therapy.

The Inhibitory Effects of an Antisense u-PAR Vector on Invasion by Highly Invasive Human Prostate Carcinoma PC-3M Cell Subclones / 中国肿瘤生物治疗杂志

Objective: To observe the inhibiting effects of an antisense u-PAR vector on invasion by highly invasive PC-3M cell subclones. Methods: The effects of an antisense vector on invasion by highly invasive PC-3M cell subclones were observed and compared in vitro by monolayer invasion assay and soft agar clone. Then, both a quantitative RT-PCR and zymography were used to exam the effects of the antisense u-PAR on activity of MMP-9 in those highly invasive cell subclones. Furthermore, the tumorigenesis rate and invasions by the cell subclones with or without the antisense u-PAR were observed in nude mice. Results: It is found that the speed of growth in vitro was slowing down by highly invasive PC-3M cell subclones transfected with the antisense u-PAR, and the ability of anchorage-independent growth of those cell subclones was also decreasing sharply,and the inhibiting rate was 79% and 60%, respectively. Although the antisense u-PAR didn′t change MMP-9 gene transcription, but they could inhibit the activation of MMP-9 of highly invasive PC-3M cell subclones. Moreover, the tumorigenesis rate of the cell subclones with the antisense u-PAR decreased and the growth of a neoplasm also slowed down. The t tests showed the difference between experimental and control groups reached statistical significance ( P