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In Vivo Inhibition of MicroRNA to Decrease Tumor Growth in Mice
Published on: August 23, 2019
MicroRNA‑34a inhibits esophageal squamous cell carcinoma progression by targeting E2F5
Hong Jiang1, Yi Guo, Kanghua Huang
1Endoscopy Center, Cancer Hospital of Shantou University Medical College, Shantou 515041, China.
Purpose:
Previous studies have explored the role of microRNA-34a (miR-34a) and E2F transcription family in several tumors, however, the expression level and oncogenesis mechanism of these two factors in esophageal squamous cancer cells (ESCC) remains unclear. Our study aims to explore the inhibitory effect of miR-34a in ESCC as well as its downstream factor E2F5.
Methods:
We explored the relevant expression level of miR-34a in human tumor tissue as well as in several ESCC cell lines. Through RNA mimic and inhibitor, we examined the specific role of miR-34a in the proliferation, apoptosis and migration of tumor cells, and we further explored the role of downstream factor E2F5 through gain- and loss-of-function analyses.
Results:
We found that the expression level of miR-34a is significantly downregulated in ESCC tissues as well as in ESCC cell lines, and miR-34a plays an inhibitory role in tumor cell proliferation and migration while it promotes tumor cell apoptosis. We further showed that E2F5 is a direct functional target of miR-34a, as it promotes tumor cell proliferation and migration and inhibits apoptosis.
Conclusions:
Our results indicate that the intrinsic expression of miR-34a was relatively low in ESCC. The anti-tumor effect of miR-34a is possibly dependent on the regulation of cell-cycle regulator E2F5.
Insights
microRNA-34a (miR-34a) is downregulated in esophageal squamous cell carcinoma (ESCC), inhibiting tumor growth. Its anti-tumor effects are linked to regulating the cell-cycle factor E2F5.
Area of Science:
- Oncology
- Molecular Biology
- Gene Regulation
Background:
- microRNA-34a (miR-34a) and E2F transcription factors are implicated in various cancers.
- The specific roles of miR-34a and its downstream targets in esophageal squamous cell carcinoma (ESCC) oncogenesis are not fully understood.
Purpose of the Study:
- To investigate the expression of miR-34a in ESCC.
- To elucidate the inhibitory effect of miR-34a on ESCC progression.
- To identify and analyze the downstream target E2F5 in the context of miR-34a's function.
Main Methods:
- Quantitative analysis of miR-34a expression in ESCC tissues and cell lines.
- In vitro experiments using RNA mimics and inhibitors to assess miR-34a's impact on cell proliferation, apoptosis, and migration.
- Gain- and loss-of-function studies to determine the role of E2F5 as a downstream target.
Main Results:
- miR-34a expression is significantly downregulated in ESCC tissues and cell lines.
- miR-34a suppresses tumor cell proliferation and migration while promoting apoptosis.
- E2F5 was identified as a direct functional target of miR-34a, promoting proliferation and migration while inhibiting apoptosis.
Conclusions:
- miR-34a exhibits low intrinsic expression in ESCC.
- The anti-tumor activity of miR-34a in ESCC is mediated through the regulation of the cell-cycle regulator E2F5.
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