RNA

Part:BBa_K3063904

Designed by: Ng Tsz Chun   Group: iGEM19_Hong_Kong_HKU   (2019-10-17)


eSIBR construct fragment for STAT3 and SOX4

The part encodes two amiRNAs that silences signal transducer and activator of transcription 3 (STAT3), and SRY (sex determining region Y)-box 4 (SOX4). STAT3-targeting and SOX4-targeting amiRNAs in the transformed salmonella, will form dsRNA upon binding to stemness STAT3 and SOX4 mRNA in tumour cells respectively. Under the aid of this particular biobrick, RNA silencing and degradation of STAT3 and SOX4 mRNA in liver cancer stem cells can be achieved simultaneously.

Sequence and Features


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    COMPATIBLE WITH RFC[12]
  • 21
    INCOMPATIBLE WITH RFC[21]
    Illegal XhoI site found at 156
    Illegal XhoI site found at 325
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    COMPATIBLE WITH RFC[25]
  • 1000
    COMPATIBLE WITH RFC[1000]


Introduction

Biology

Part structure

The part for dual gene-silencing of STAT3 and SOX4 in cancer stem cells

BBa_K3063901 & BBa_K3063902 The BioBrick encodes STAT3-targeting and SOX4-targeting amiRNA. With the help of enhanced synthetic inhibitory BIC/miR-155 RNA (eSIBR) vector, pri-miRNA hairpins as shown below are transcribed and later processed into mature miRNAs in Salmonella Typhimurium, achieving STAT3 and SOX4 knockdown in targeted cancer cells.

T--Hong_Kong_HKU--STAT3.jpg T--Hong_Kong_HKU--SOX4.jpg

Part Therapeutics

Recent findings have demonstrated that STAT3-mediated signaling is implicated in regulating the undifferentiated phenotype of stem cells and suppressing antitumor immunity, while in vitro silencing is capable of inducing G2/M arrest in a variety of cancer cell types. [1] [2] [3] Hence, we postulated that STAT3-targeting amiRNA, carried by salmonella, can effectively silence STAT3 expression in liver stem cells, which in turns minimises the cancer stemness.

Aside from the therapeutic potential of STAT3, evidence has also been accumulating that SOX4, whose expression initiated by STAT3, orchestrates epithelIal-to-mesenchymal transition (EMT) through upregulating a series of EMT-inducing transcription factors, which then enhances cellular growth as well as transformation. [4] SOX4 knockdown can effectively reduce the activation of transforming growth factor-beta (TGF-β) signaling, attenuating the invasion of cancer cells. [5]

References

  1. ↑ Galoczova, M., Coates, P., & Vojtesek, B. (2018). STAT3, stem cells, cancer stem cells and p63. Cellular & molecular biology letters, 23(1), 12.
  2. ↑ Raz, R., Lee, C. K., Cannizzaro, L. A., d’Eustachio, P., & Levy, D. E. (1999). Essential role of STAT3 for embryonic stem cell pluripotency. Proceedings of the National Academy of Sciences, 96(6), 2846-2851.
  3. ↑ Li, J., Liu, Y. Y., Yang, X. F., Shen, D. F., Sun, H. Z., Huang, K. Q., & Zheng, H. C. (2018). Effects and mechanism of STAT3 silencing on the growth and apoptosis of colorectal cancer cells. Oncology letters, 16(5), 5575-5582.
  4. ↑ Lourenço, A. R., & Coffer, P. J. (2017). SOX4: joining the master regulators of epithelial-to-mesenchymal transition?. Trends in cancer, 3(8), 571-582.
  5. ↑ Foronda, M., Martínez, P., Schoeftner, S., Gómez-López, G., Schneider, R., Flores, J. M., ... & Blasco, M. A. (2014). Sox4 links tumor suppression to accelerated aging in mice by modulating stem cell activation. Cell reports, 8(2), 487-500.
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