Combined mRNA expression levels of members of the urokinase plasminogen activator (uPA) system correlate with disease-associated survival of soft-tissue sarcoma patients

Identification of uPAR Variants Acting as ceRNAs in Leukaemia Cells

Simple Summary

The urokinase (uPA) receptor (uPAR) concentrates proteolytic activities on the cell surface and is an adhesion receptor for vitronectin. Urokinase/Vitronectin binding to uPAR activates intracellular signals promoting cell adhesion, migration, proliferation and survival. Thus, uPAR can sustain most activities of malignant cells and, accordingly, increased uPAR expression is associated with poor prognosis in several malignancies. We previously demonstrated that, in leukaemia cells, the uPAR 3′untranslated region (3′UTR) up-regulates the expression of pro-tumoral factors by recruiting microRNAs targeting their mRNAs, thus acting as competitive endogenous RNA (ceRNA). Here, we identify 3′UTR-containing variants of uPAR mRNA in leukaemia cells and demonstrate that the over-expression of uPAR Δ5-variant mRNA promotes expression of pro-tumoral factors and increase in biological activities, probably by its ceRNA activity. On this basis, we propose that uPAR may play a crucial role in cancer biology also at mRNA level, through the ceRNA activity of its variants.

Abstract

The 3′untranslated region (3′UTR) of the urokinase (uPA) receptor (uPAR) mRNA can act as a competitive endogenous RNA (ceRNA) in acute myeloid leukaemia (AML) cells, promoting the expression of pro-tumoral targets, including uPAR. Here, we identified three variants of uPAR mRNA containing the 3′UTR, in KG1 and U937 leukaemia cells expressing low and high uPAR levels, respectively. Identified variants lack exon 5 (uPAR Δ5) or exon 6 (uPAR Δ6) or part of exon 6, exon 7 and part of 3′UTR (uPAR Δ6/7). uPAR Δ5 and uPAR Δ6 transcript levels were higher in U937 cells compared to KG1 cells. Both uPAR variants were expressed also in AML blasts, at higher levels as compared to CD34 hematopoietic cells from healthy donors. The presence of the 3′UTR conferred high instability to the uPAR Δ5 variant transcript, preventing its translation in protein. Overexpression of the uPAR Δ5-3′UTR variant regulated the expression of some pro-tumoral factors previously reported to be regulated by the 3′UTR of uPAR and increased KG1 cell adhesion, migration and proliferation. These results demonstrate the expression of uPAR mRNA variants containing the 3′UTR in AML cells and the ceRNA activity and the biological effects of the uPAR Δ5-3′UTR variant.

MiR-155-5p and MiR-203a-3p Are Prognostic Factors in Soft Tissue Sarcoma

Soft tissue sarcoma (STS) is a heterogeneous group of rare malignancies with a five-year survival rate of approximately 50%. Reliable molecular markers for risk stratification and subsequent therapy management are still needed. Therefore, we analyzed the prognostic potential of miR-155-5p and miR-203a-3p expression in a cohort of 79 STS patients. MiR-155-5p and miR-203a-3p expression was measured from tumor total RNA by qPCR and correlated with the demographic, clinicopathological, and prognostic data of the patients. Elevated miR-155-5p expression was significantly associated with increased tumor stage and hypoxia-associated mRNA/protein expression. High miR-155-5p expression and low miR-203a-3p expression, as well as a combination of high miR-155-5p and low miR-203a-3p expression, were significantly associated with poor disease-specific survival in STS patients in the Kaplan–Meier survival analyses (p = 0.027, p = 0.001 and p = 0.0003, respectively) and in the univariate Cox regression analyses (RR = 1.96; p = 0.031; RR = 2.59; p = 0.002 and RR = 4.76; p = 0.001, respectively), but not in the multivariate Cox regression analyses. In conclusion, the oncomiR miR-155-5p and the tumor suppressor-miR miR-203a-3p exhibit an association with STS patient prognosis and are suggested as candidates for risk assessment.

Prognostic implications of the co-detection of the urokinase plasminogen activator system and osteopontin in patients with non-small-cell lung cancer undergoing radiotherapy and correlation with gross tumor volume

BACKGROUND

The urokinase plasminogen activator system (uPA, uPAR, PAI‑1) is upregulated in cancer and high plasma levels are associated with poor prognosis. Their interaction with hypoxia-related osteopontin (OPN) which is also overexpressed in malignant tumors suggests potential clinical relevance. However, the prognostic role of the uPA system in the radiotherapy (RT) of non-small-cell lung cancer (NSCLC), particularly in combination with OPN, has not been investigated so far.

METHODS

uPA, uPAR, PAI‑1 and OPN plasma levels of 81 patients with locally advanced or metastasized NSCLC were prospectively analyzed by ELISA before RT and were correlated to clinical patient/tumor data and prognosis after RT.

RESULTS

uPAR plasma levels were higher in M1; uPA and PAI‑1 levels were higher in M0 NSCLC patients. uPAR correlated with uPA (p < 0.001) which also correlated with PAI‑1 (p < 0.001). The prognostic impact of OPN plasma levels in the RT of NSCLC was previously reported by our group. PAI‑I plasma levels significantly impacted overall (OS) and progression-free survival (PFS). Low PAI‑1 levels were associated with a significantly reduced OS and PFS with a nearly 2‑fold increased risk of death (p = 0.029) and tumor progression (p = 0.029). In multivariate analysis, PAI‑1 levels remained an independent prognostic factor for OS and PFS with a 3‑fold increased risk of death (p = 0.001). If PAI‑1 plasma levels were combined with OPN or tumor volume, we found an additive prognostic impact on OS and PFS with a 2.5- to 3‑fold increased risk of death (p = 0.01).

CONCLUSION

Our results suggest that PAI-1 but not uPA and uPAR might add prognostic information in patients with advanced NSCLC undergoing RT. High pretreatment PAI-1 plasma levels were found predominantly in M0-stage patients and indicate a favorable prognosis as opposed to OPN where high plasma levels are associated with poor survival and metastasis. In combination, PAI-1 and OPN levels successfully predicted outcome and additively correlated with prognosis. These findings support the notion of an antidromic prognostic impact of OPN and PAI-1 plasma levels in the RT of advanced NSCLC.

CMG2 Expression Is an Independent Prognostic Factor for Soft Tissue Sarcoma Patients

The capillary morphogenesis gene 2 (CMG2), also known as the anthrax toxin receptor 2 (ANTXR2), is a transmembrane protein putatively involved in extracellular matrix (ECM) adhesion and tissue remodeling. CMG2 promotes endothelial cell proliferation and exhibits angiogenic properties. Its downregulation is associated with a worsened survival of breast carcinoma patients. Aim of this study was to analyze the CMG2 mRNA and protein expression in soft tissue sarcoma and their association with patient outcome. CMG2 mRNA was measured in 121 tumor samples of soft tissue sarcoma patients using quantitative real-time PCR. CMG2 protein was evaluated in 52 tumor samples by ELISA. CMG2 mRNA was significantly correlated with the corresponding CMG2 protein expression (r_s = 0.31; p = 0.027). CMG2 mRNA expression was associated with the mRNA expressions of several ECM and tissue remodeling enzymes, among them CD26 and components of the uPA system. Low CMG2 mRNA expression was correlated with a worsened patients’ disease-specific survival in Kaplan-Meier analyses (mean patient survival was 25 vs. 96 months; p = 0.013), especially in high-stage tumors. A decreased CMG2 expression is a negative prognostic factor for soft tissue sarcoma patients. CMG2 may be an interesting candidate gene for the further exploration of soft tissue sarcoma genesis and progression.

Targeting pediatric sarcoma with a bispecific ligand immunotoxin targeting urokinase and epidermal growth factor receptors

Children with high risk sarcoma have a poor prognosis despite surgical resection, irradiation and chemotherapy. Alternative therapies are urgently needed. Urokinase-type plasminogen activator receptor (uPAR) and epidermal growth factor receptor (EGFR) are surface proteins expressed by some pediatric sarcomas. We show for the first time that a de-immunized bispecific ligand toxin, EGFATFKDEL, directed against EGFR and uPAR, successfully targets pediatric sarcoma. Using flow cytometry, we identified a rhabdomyosarcoma (RMS) cell line, RH30, that expresses both uPAR and EGFR, and a Ewing sarcoma (EWS) cell line, TC-71, that expresses only uPAR. We tested the differential sensitivity of these two sarcoma cell lines to toxin-induced killing, using both in vitro assays and an in vivo murine model. We show that pediatric sarcomas are highly sensitive to EGFATFKDEL (at subnanomolar concentrations) in vitro. In vivo, tumor growth was significantly attenuated after treatment with EGFTFKDEL, compared to untreated controls, in both RH30 and TC-71 tumor bearing mice. In addition, we found that simultaneously targeting both receptors in a dual positive cell line was more effective than targeting a single receptor or antigen, resulting in a greater tumor response, including complete tumor regression in an animal model of bulky disease. Our findings provide support for further exploration of bispecific targeting of pediatric sarcomas with bispecific ligand toxins, such as EGFATFKDEL.

[F10 expressions in cervical cancer tissues]

OBJECTIVE

To detect the expression of F10 at both mRNA and protein levels in cervical cancer tissues and explore its role in the occurrence and progression of cervical cancer.

METHODS

F10 expressions at mRNA and protein levels were detected in 30 pairs of cervical cancer tissues and adjacent tissues using RT-PCR and immunohistochemistry.

RESULTS

The mRNA and protein expressions of F10 were significantly higher in cervical cancer tissues than in the adjacent normal tissues (P<0.05). F10 expression was significantly higher in poorly differentiated cervical cancer than in well differentiated cancer tissues, and was also lower in patients with preoperative chemotherapy than in those without chemotherapy.

CONCLUSION

F10 expression level is inversely correlated with the differentiation of cervical cancer and possible plays a role in the tumorigenesis and progression of cervical cancer.

MicroRNA-182 drives metastasis of primary sarcomas by targeting multiple genes

Metastasis causes most cancer deaths, but is incompletely understood. MicroRNAs can regulate metastasis, but it is not known whether a single miRNA can regulate metastasis in primary cancer models in vivo. We compared the expression of miRNAs in metastatic and nonmetastatic primary mouse sarcomas and found that microRNA-182 (miR-182) was markedly overexpressed in some tumors that metastasized to the lungs. By utilizing genetically engineered mice with either deletion of or overexpression of miR-182 in primary sarcomas, we discovered that deletion of miR-182 substantially decreased, while overexpression of miR-182 considerably increased, the rate of lung metastasis after amputation of the tumor-bearing limb. Additionally, deletion of miR-182 decreased circulating tumor cells (CTCs), while overexpression of miR-182 increased CTCs, suggesting that miR-182 regulates intravasation of cancer cells into the circulation. We identified 4 miR-182 targets that inhibit either the migration of tumor cells or the degradation of the extracellular matrix. Notably, restoration of any of these targets in isolation did not alter the metastatic potential of sarcoma cells injected orthotopically, but the simultaneous restoration of all 4 targets together substantially decreased the number of metastases. These results demonstrate that a single miRNA can regulate metastasis of primary tumors in vivo by coordinated regulation of multiple genes.

Association of tissue mRNA and serum antigen levels of members of the urokinase-type plasminogen activator system with clinical and prognostic parameters in prostate cancer

The objective was to determine the mRNA expression and protein levels of uPA system components in tissue specimens and serum samples, respectively, from prostate cancer (PCa) patients and to assess their association with clinicopathological parameters and overall survival (OS). The mRNA expression levels of uPA, its receptor (uPAR), and its inhibitor type 1 (PAI-1) were analyzed in corresponding malignant and adjacent nonmalignant tissue specimens from 132 PCa patients by quantitative PCR. Preoperative serum samples from 81 PCa patients were analyzed for antigen levels of uPA system members by ELISA. RNA levels of uPA system components displayed significant correlations with each other in the tumor tissues. A significantly decreased uPA mRNA expression in PCa compared to the corresponding nonmalignant tissue was detected. High uPA mRNA level was significantly associated with a high Gleason score. Elevated concentration of soluble uPAR (suPAR) in serum was significantly associated with a poor OS of PCa patients (P = 0.022). PCa patients with high suPAR levels have a significantly higher risk of death (multivariate Cox's regression analysis; HR = 7.12, P = 0.027). The association of high suPAR levels with poor survival of PCa patients suggests a prognostic impact of suPAR levels in serum of cancer patients.

Impact of expression of the uPA system in sarcomas

The uPA system mainly comprises the urokinase-type plasminogen activator uPA, the cell-surface receptor uPA receptor and the inhibitor PAI-1. Its clinical and prognostic impact especially in breast cancer is well investigated. In this short report, we summarize the published data describing expression of uPA, PAI-1 and uPA receptor and their relevance to clinical and survival data in sarcomas underlining their impact as tumor biomarkers in this tumor type as well.

mRNA expression levels of the biological factors uPAR, uPAR-del4/5, and rab31, displaying prognostic value in breast cancer, are not clinically relevant in advanced ovarian cancer

High tumor tissue mRNA expression of the tumor biological factors uPAR, uPAR-del4/5, or rab31 is associated with shorter distant metastasis-free and overall survival in breast cancer patients. To evaluate whether these factors are also clinically relevant in ovarian cancer, we quantified the respective mRNA levels in primary tumor tissue of advanced ovarian cancer patients (n=103) and evaluated their association with clinicopathological parameters and patients' prognosis. mRNA expression levels of all three markers did not show any significant association with overall or progression-free survival, demonstrating that these factors have no prognostic value in advanced ovarian cancer.