1. Deciphering and targeting EMT-mediated cancer stemness
Muh-Hwa Yang, M.D., Ph.D.
Institute of Clinical Medicine, National Yang-Ming University
Division of Hematology-Oncology, Department of Medicine,
Taipei Veterans General Hospital

2. Epithelial-Mesenchymal Transition (EMT)
EMT is a biologic process that the polarized epithelial cell, which normally interacts with basement membrane, to undergo multiple changes that enable it to assume a mesenchymal cell phenotype:
enhanced migratory capacity
Invasiveness
elevated resistance to apoptosis
increased production of ECM components
J Clin Invest 2009;119:

3. EMT is defined by cellular morphology
Yang MH et al. Nat Cell Biol 2010; 12:
Yang MH et al. Nat Cell Biol 2008; 10:

4. EMT in the invasive front of cancer
Normal
Tumor
Invasive front
E-cadherin
vimentin
Yang MH et al. Nat Cell Biol 2008; 10:

5. EMT signaling in cancer metastasis
Yang & Weinberg. Cell 2004; 118:277-9

6. EMT Generates Cells with Properties of Stem Cells
Mani et al. Cell 2008:133:704-15

7. 1. Blocking EMT-induced cancer stem cells expansion reverses anti-EGFR resistance in colon cancer

8. Symmetrical vs. Asymmetrical Division in Stem Cells
Stem cells undergo two types of division:
ACD (asymmetrical cell division): maintain tissue homeostasis
SCD (symmetrical cell division): promote tissue regeneration

9. Deregulation of asymmetric cell division
in cancer stem cells
Asymmetric cell division: one daughter stem cells and one differentiated daughter cells, maintain stem cell pool
Symmetric cell division: two daughter stem cells, expand stem cell pool
Question: whether EMT expands CSC pool
for facilitating cancer progression?
Cell Stem Cell 2013;12:602-15

10. Enrichment colon cancer stem cells (CCSC) through tumorispheres
SDCSC: sphere-derived cancer stem cells
SDAC: sphere-derived adherent cells

11. Increased symmetrical division in CCSC
CE: co-expression
IE: inverse expression

12. miR146a is the top-ranked miRNA in two CCSC miR-seq

13. miR146a is segregated into the daughter stem cells

14. Snail is the major EMT factor for guiding symmetrical division
CE: co-expression
IE: inverse expression

15. Snail regulates MIR146A transcription through -catenin/TCF4 complex

16. miR146a represses Numb to activate Wnt pathway

17. Numb and cell division mode determination
A cell-fate determinant during development
Has been found to be associated with Notch1, LNX1, EPS15
Plays crucial role in asymmetrical cell division.
During cell division, Numb is asymmetrically localized in daughter cells. The daughter cell containing Numb is able to differentiate.
Inhibits Notch signaling through ubiquitylation of Notch

18. Numb interacts with -catenin to promote its polyubiquitylation & degradation

20. EGFR Expression in Solid Tumors
EGFR is expressed in a variety of solid tumors
Head and neck (SCCHN)
Tumor Target %
Colorectal cancer
72–89
Head and neck cancer
95–100
Lung cancer (NSCLC)
40–80
Breast cancer
14–91
Ovarian cancer
35–70
Renal cell cancer
50–90
Pancreatic cancer
30-95
Colorectal
Lung
(NSCLC)
Cunningham et al. N Engl J Med 2004;351:337–345; Grandis et al. Cancer 1996;78:1284–1292; Salomon et al. Crit Rev Oncol Hematol 1995;19:183–232; Walker & Dearing. Breast Cancer Res Treat 1999;53:167–176; Folprecht et al. ASCO 2004 (Abs283).

22. KRAS mutation confers anti-EGFR resistance in CCSC

23. Crosstalk of EGFR and Wnt pathway in CCSC

24. Inhibiting MEK or Wnt activity of SDCSCs
reduces symmetric division and suppresses tumor growth
PD98059: MEK inhibitor
IWR: Wnt inhibitor

25. Snail(+)Numb(-) profile predicts cetuximab resistance & poor prognosis
of colorectal cancer patients
Yang MH*, et al. Nat Cell Biol 2014;16:

26. News & Views in Nat Cell Biol 2014;16: 212-214

27. 2. Targeting Twist1-mediated signal prevents EMT induces invasiveness in head and neck cancer

28. The role of let-7 family microRNAs in stem cell and cancer
let-7 is important for stem cell differentiation
Cell 140, February 19, 2010
let-7 is critical for suppressing cancer progression
Nature Genetics , volume 41, number 7 (July ,2009 )

29. Downregulation of let-7i enhances stem-like properties

30. Twist1 represses let-7i expression

31. let-7i does not affect EMT phenotype

32. EMT reorganizes cytoskeleton to enable
cancer cell movement
Nat Rev Mol Cell Biol 2014; 15:178-96

34. Repression of let-7i promotes cellular protrusions & elongation
in 3D culture
OECM1-
mCherry
let7i-1
FaDu-
spg-ctrl
spg-let7i-1
F-actin
/DAPI

35. let-7i is critical in Twist1-induced movement
through targeting the Rac1 activators NEDD9 & DOCK3

36. Repression of let-7i is critical for Twist1-induced local invasion
FaDu + Twist1 + let7i
FaDu + Twist1
FaDu + control vector
FaDu + let7i sponge
Yang WH, et al. Nat Cell Biol 2012; 14:

37. Clinical Characteristics of head and neck cancer
Includes cancers originating from oral cavity, oropharynx, hypopharynx, and larynx.
4th cause of male cancer death in Taiwan
> 90 %: squamous cell carcinoma (HNSCC)
Associated with smoking, drinking, betel nut chewing
Frequent local invasion with tissue destruction but low incidence of distant metastasis

38. Clinical significance of let-7i in head and neck cancer patients
Invasion to adjacent tissue

39. Current Biology 2012

40. Head and neck cancer and glioma are
“invasive-predominant cancers”.
Is there any common strategy
for treating the invasive-predominant
cancers?

41. Imipramine blue halts mesenchymal migration of
head and neck cancer

42. Imipramine blue treatment reverses Twist1-induced EMT

43. IB inhibits NF-B activity in head and neck cancer cells

44. Imipramine blue promotes Twist1 degradation through FBXL14-mediated polyubiquitination44

45. Imipramine blue promotes degradation of multiple EMT factors

46. Blocking Twist-mediated signals attenuates
EMT and local invasion
Yang WH., et al. (Oncogene 2015 Aug 10 online )

47. Acknowledgements Prof. Hsei-Wei Wang (NYMU, Taiwan)
Institute of Clinical Medicine,
National Yang-Ming University,
Taipei, Taiwan
Wei-Lun Hwang (postdoc)
Wen-Hao Yang (previous postdoc)
Chun-Hung Chou (PhD student)
Chia-Hsin Hsieh (PhD student)
Po-Hsien Chiu (research assistant)
Hsin-Yi Lang (research assistant)
Hsiao-Jun Wang (research assistant)
Wen-Hao Hsu (research assistant)
Yun-Hsuan Su (master student)
Prof. Hsei-Wei Wang (NYMU, Taiwan)
Prof. Shyh-Kuan Tai (Taipei Veterans General Hospital)
Prof. Jack L. Arbiser (Emory School of Medicine, USA)