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Updated: May 11, 2026
Mouse Bladder Wall Injection
Published on: July 12, 2011
Enhancing RECK Expression Through miR-21 Inhibition: A Promising Strategy for Bladder Carcinoma Control
Paulo Rodolfo Moraes Dos Santos1,2, Paulo Ricardo da Silva Gomes1,3, Poliana Romão1
1Laboratorio de Investigação Médica 55 (LIM55), Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, Brazil.
Abstract:
Bladder carcinoma (BC) is the tenth most frequent malignancy worldwide, with high morbidity and mortality rates. Despite recent treatment advances, high-grade BC and muscle-invasive BC present with significant progression and recurrence rates, urging the need for alternative treatments. The microRNA-21 (miR-21) has superexpression in many malignancies and is associated with cellular invasion and progression. One of its mechanisms of action is the regulation of RECK, a tumor suppressor gene responsible for inhibiting metalloproteinases, including MMP9. In a high-grade urothelial cancer cell line, we aimed to assess if miR-21 downregulation would promote RECK expression and decrease MMP9 expression. We also evaluated cellular migration and proliferation potential by inhibition of this pathway. In a T24 cell line, we inhibited miR-21 expression by transfection of a specific microRNA inhibitor (anti-miR-21). There were also control and scramble groups, the last with a negative microRNA transfected. After the procedure, we performed a genetic expression analysis of miR-21, RECK, and MMP9 through qPCR. Migration, proliferation, and protein expression were evaluated via wound healing assay, colony formation assay, flow cytometry, and immunofluorescence.After anti-miR-21 transfection, miR-21 expression decreased with RECK upregulation and MMP9 downregulation. The immunofluorescence assay showed a significant increase in RECK protein expression (p < 0.0001) and a decrease in MMP9 protein expression (p = 0.0101). The anti-miR-21 transfection significantly reduced cellular migration in the wound healing assay (p < 0.0001). Furthermore, in the colony formation assay, the anti-miR-21 group demonstrated reduced cellular proliferation (p = 0.0008), also revealed in the cell cycle analysis by flow cytometry (p = 0.0038). Our results corroborate the hypothesis that miR-21 is associated with BC cellular migration and proliferation, revealing its potential as a new effective treatment for this pathology.
Insights
Inhibiting microRNA-21 (miR-21) in bladder cancer cells reduced cell migration and proliferation. This downregulation also increased the tumor suppressor RECK and decreased MMP9, suggesting miR-21 as a potential therapeutic target.
Area of Science:
- Oncology
- Molecular Biology
- Biochemistry
Background:
- Bladder carcinoma (BC) is a prevalent malignancy with high recurrence rates, necessitating novel therapeutic strategies.
- MicroRNA-21 (miR-21) is overexpressed in various cancers and linked to tumor invasion and progression.
- miR-21 regulates RECK, a tumor suppressor that inhibits matrix metalloproteinases like MMP9, crucial in cancer metastasis.
Purpose of the Study:
- To investigate the effect of miR-21 downregulation on RECK and MMP9 expression in high-grade bladder cancer cells.
- To evaluate the impact of inhibiting the miR-21/RECK/MMP9 pathway on cellular migration and proliferation.
Main Methods:
- Utilized a T24 bladder cancer cell line and transfected it with an anti-miR-21 inhibitor.
- Assessed gene and protein expression of miR-21, RECK, and MMP9 using qPCR and immunofluorescence.
- Evaluated cellular migration and proliferation via wound healing, colony formation assays, and flow cytometry.
Main Results:
- Anti-miR-21 transfection significantly decreased miR-21 expression, upregulated RECK, and downregulated MMP9.
- RECK protein expression increased (p<0.0001), while MMP9 protein expression decreased (p=0.0101).
- Cellular migration (p<0.0001), proliferation (p=0.0008), and cell cycle progression (p=0.0038) were significantly reduced.
Conclusions:
- miR-21 downregulation effectively suppresses bladder carcinoma cell migration and proliferation.
- The findings support the role of miR-21 in bladder cancer progression and highlight its potential as a therapeutic target.
