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Inducible and Reversible Dominant-negative DN Protein Inhibition
Published on: January 7, 2019
MiR-433 inhibits retinoblastoma malignancy by suppressing Notch1 and PAX6 expression
Xiaohua Li1, Lan Yang1, Tianjiao Shuai1
1Department of Ophthalmology, Hongqi Hospital of Mudanjiang Medical University, Mudanjiang, Heilongjiang 157011, China.
Abstract:
Retinoblastoma (RB) is the most frequent primary intraocular cancer. It has been demonstrated by previous studies that retinoblastoma is initiated primarily by the inactivation of the retinoblastoma Rb1 gene in retinal cells. However, additional genetic alterations than Rb1 mutation could play important roles in the process of transforming benign retinal cells into retinoblastoma tumor cells. In this study, we identified that microRNA miR-433 is one of such genetic factors. We found that the expression levels of miR-433 were downregulated in RB tissues. We also determined that miR-433 negatively regulated RB cell proliferation, migration and invasion, and induced cell cycle arrest and apoptosis of RB cells. We used bioinformatics method to predict and confirmed that Notch1 and PAX6 were miR-433 target genes in RB cells. Importantly, we demonstrated that restoration of Notch1 and PAX6 expression partially rescued the inhibition of cell proliferation and metastasis induced by miR-433 overexpression, suggesting that miR-433 regulates RB cell proliferation and metastasis through suppressing the expression of Notch1 and PAX6.
Insights
MicroRNA miR-433 is downregulated in retinoblastoma (RB), a common eye cancer. This microRNA inhibits RB cell growth and spread by targeting Notch1 and PAX6 genes.
Area of Science:
- Ophthalmology
- Oncology
- Molecular Biology
Background:
- Retinoblastoma (RB) is the most common primary intraocular cancer in children.
- While Rb1 gene inactivation initiates RB, other genetic factors contribute to tumor development.
- The role of microRNAs in RB pathogenesis requires further elucidation.
Purpose of the Study:
- To investigate the role of microRNA miR-433 in retinoblastoma.
- To identify the downstream targets of miR-433 in RB cells.
- To understand the mechanism by which miR-433 influences RB progression.
Main Methods:
- Analysis of miR-433 expression levels in RB tissues.
- In vitro assays to assess the effects of miR-433 on RB cell proliferation, migration, invasion, cell cycle, and apoptosis.
- Bioinformatic prediction and experimental validation of miR-433 target genes (Notch1 and PAX6).
Main Results:
- miR-433 expression is significantly downregulated in retinoblastoma tissues.
- Overexpression of miR-433 inhibits RB cell proliferation, migration, and invasion.
- miR-433 induces cell cycle arrest and apoptosis in RB cells.
- Notch1 and PAX6 were confirmed as direct targets of miR-433.
- Restoring Notch1 and PAX6 partially reversed the anti-proliferative and anti-metastatic effects of miR-433.
Conclusions:
- miR-433 functions as a tumor suppressor in retinoblastoma.
- miR-433 exerts its tumor-suppressive effects by downregulating Notch1 and PAX6.
- Targeting miR-433 or its downstream pathways may offer therapeutic strategies for retinoblastoma.
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