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Lin28 induces epithelial-to-mesenchymal transition and stemness via downregulation of let-7a in breast cancer cells.

ABSTRACT: The RNA-binding protein Lin28 is known to promote malignancy by inhibiting the biogenesis of let-7, which functions as a tumor suppressor. However, the role of the Lin28/let-7 axis in the epithelial-to-mesenchymal transition (EMT) and stemness in breast cancer has not been clearly expatiated. In our previous study, we demonstrated that let-7 regulates self-renewal and tumorigenicity of breast cancer stem cells. In the present study, we demonstrated that Lin28 was highly expressed in mesenchymal (M) type cells (MDA-MB-231 and SK-3rd), but it was barely detectable in epithelial (E) type cells (MCF-7 and BT-474). Lin28 remarkably induced the EMT, increased a higher mammosphere formation rate and ALDH activity and subsequently promoted colony formation, as well as adhesion and migration in breast cancer cells. Furthermore, we demonstrated that Lin28 induced EMT in breast cancer cells via downregulation of let-7a. Strikingly, Lin28 overexpression was found in breast cancers that had undergone metastasis and was strongly predictive of poor prognoses in breast cancers. Given that Lin28 induced the EMT via let-7a and promoted breast cancer metastasis, Lin28 may be a therapeutic target for the eradication of breast cancer metastasis.

SUBMITTER: Liu Y

PROVIDER: S-EPMC3859647 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature

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Lin28 induces epithelial-to-mesenchymal transition and stemness via downregulation of let-7a in breast cancer cells.

Liu Yujie Y Li Haiyan H Feng Juan J Cui Xiuying X Huang Wei W Li Yudong Y Su Fengxi F Liu Qiang Q Zhu Jiujun J Lv Xiaobin X Chen Jianing J Huang Di D Yu Fengyan F

PloS one 20131211 12

The RNA-binding protein Lin28 is known to promote malignancy by inhibiting the biogenesis of let-7, which functions as a tumor suppressor. However, the role of the Lin28/let-7 axis in the epithelial-to-mesenchymal transition (EMT) and stemness in breast cancer has not been clearly expatiated. In our previous study, we demonstrated that let-7 regulates self-renewal and tumorigenicity of breast cancer stem cells. In the present study, we demonstrated that Lin28 was highly expressed in mesenchymal ...[more]

PMID: 24349438

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Project description:Modern treatment strategies provide better overall survival in cancer patients, primarily by controlling tumor growth. However, off-target and systemic toxicity, tumor recurrence, and resistance to therapy are still inadvertent hurdles in current treatment regimens. Similarly, metastasis is another deadly threat to patients suffering from cancer. This has created an urgent demand to come up with new drugs having anti-metastatic potential and minimum side effects. Thus, this study was aimed at exploring the anti-proliferative and anti-metastatic potential of colocynth medicinal plant. Results from MTT assay, morphological visualization of cells and scratch assay indicated a role of ethanol and acetone extracts of fruit pulp of the colocynth plant in inhibiting cell viability, enhancing cell cytotoxicity and preventing cell migration in various cancer cell types, including breast cancer cell lines MCF-7 and MDA-MB-231, and cervical cancer cell line SiHa, subsequently having a low cytotoxic effect on mononuclear PBMC and macrophage J774A cells. Our study in metastatic MDA-MB-231 cells showed that both ethanol and acetone pulp extracts decreased transcript levels of the anti-apoptotic genes BCL2 and BCLXL, and a reverse effect was observed for the pro-apoptotic genes BAX and caspase 3. Additionally, enhanced caspase 3 activity and downregulated BCL2 protein were seen, indicating a role of these extracts in inducing apoptotic activity. Moreover, MDA-MB-231 cells treated with both these extracts demonstrated up-regulation of the epithelial gene keratin 19 and down-regulation of the mesenchymal genes, vimentin, N-cadherin, Zeb1 and Zeb2 compared to control, suggesting a suppressive impact of these extracts in epithelial to mesenchymal transition (EMT). In addition, these extracts inhibited colony and sphere formation with simultaneous reduction in the transcript level of the stemness associated genes, BMI-1 and CD44. It was also found that both the plant extracts exhibited synergistic potential with the chemotherapeutic drug doxorubicin to inhibit cancer viability. Furthermore, GC-MS/MS analysis revealed the presence of certain novel compounds in both the extracts that are responsible for the anti-cancer role of the extracts. Overall, the results of this report suggest, for the first time, that colocynth fruit pulp extracts may block the proliferative as well as metastatic activity of breast cancer cells.

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Dataset Information

Lin28 induces epithelial-to-mesenchymal transition and stemness via downregulation of let-7a in breast cancer cells.

Publications

Lin28 induces epithelial-to-mesenchymal transition and stemness via downregulation of let-7a in breast cancer cells.

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