Molecular Biology of the Cell - NHRI · Figure 19-1 Molecular Biology of the Cell (© Garland...
Transcript of Molecular Biology of the Cell - NHRI · Figure 19-1 Molecular Biology of the Cell (© Garland...
徐沺 Tien Hsu, PhD
Dean, College of Health Sciences and Technology
University Chair Professor
Department of Biomedical Sciences and Engineering
National Central University
Tel: 03-4256534
TUMOR MICROENVIRONMENT
Cancer is not a localized lump of cells; it's a
systemic disease.
癌症不是在定點位置的一團細胞,而是一個系統化的疾病。
Classic view of cancer:
Mutations in a cell —> uncontrolled proliferation —> Cancer
Systems biology of cancer:
Cellular transformation (genetic or epigenetic)
Systems changes in cell (metabolism,
global gene expression change)
Bidirectional interaction with
microenvironment:
angiogenesis, extracellular
matrix remodeling
Induction of myeloid response,
mobilization of immune responses
Cancer
LESSON I:
EPITHELIUM
Epithelium
Cancer and fibroblasts
上皮組織
E-cadherin
Lgl
Injured kidney, basement
membrane break down
BM
Epithelial tissues constitute most of the organs and skin
Three basic shapes of epithelial cells,
either single layer or stratified.
kidney tubules
lung alveoli (A)
villi of the
small
intestine
Columnarrespiratory
epithelium
esophagus
Simple cuboidal
Simple columnar
Simple
squamous
A: epithelium; B: cilia; C: nuclei
A: cells; B: nuclei
Stratified
squamous
A: epithelium; B: top layer flat
A: cells; B: nuclei; C: cell membrane
(立方型)
(柱狀) (鱗狀)
80% of the human solid tumors originate from
epithelial tissues.
The structure of the intestinal epithelia
An intestine villus (絨毛) is composed of epithelium
So the epithelium forms
a tight barrier that
separates the lumen (管腔) and the underlying
tissue, yet allows for
bidirectional exchange
of materials.
Figure 19-1 Molecular Biology of the Cell (© Garland Science 2008)
The defining characteristics of an epithelium are
(i) asymmetrical distribution of subcellular components
(ii) cell-cell adhesion
(iii) attachment to substratum (matrix)
(細胞外基質蛋白)
(細胞骨架纖維)
Figure 19-2 Molecular Biology of the Cell (© Garland Science 2008)
Types of cellular junctions (細胞連結)
粘著連接adherens junction
desmosome
間隙連接gap junction
緊密連接tight junction
遮檔型連接錨定型連接 渠道型連接 訊號轉播連接
Synaptic junction
filament
Table 19-1 Molecular Biology of the Cell (© Garland Science 2008)
Figure 19-3 Molecular Biology of the Cell (© Garland Science 2008)
(頂側)
(基底側)
Figure 19-4 Molecular Biology of the Cell (© Garland Science 2008)
Anchoring junctions
Table 19-2 Molecular Biology of the Cell (© Garland Science 2008)
Figure 19-9a Molecular Biology of the Cell (© Garland Science 2008)
Structure of E-cadherin
Homophilic adhesion
Figure 19-9c Molecular Biology of the Cell (© Garland Science 2008)
An adherens junction is composed of a cluster of E-cadherins
Figure 19-14 Molecular Biology of the Cell (© Garland Science 2008)
(e.g. a-catenin)
E-cadherin is connected to actin cytoskeleton via interacting
proteins.
b-catenin
Figure 19-15 Molecular Biology of the Cell (© Garland Science 2008)
Figure 19-17a Molecular Biology of the Cell (© Garland Science 2008)
Desmosomes (Greek, desmos = band)
Three types of cytoskeletons:
Microfilaments: actin (肌動蛋白)Intermediate filaments: cytokeratins (細胞角蛋白)Microtubules: tubulins (微管蛋白)
Figure 19-17b Molecular Biology of the Cell (© Garland Science 2008)
Desmosomes
Figure 19-17c, d Molecular Biology of the Cell (© Garland Science 2008)
Desmosomes
Figure 19-18 Molecular Biology of the Cell (© Garland Science 2008)
integrin a6b4 to
basement
membrane
Figure 19-25 Molecular Biology of the Cell (© Garland Science 2008)
Tight junctions
E-cadherin
(Claudin 2, 4
can allow ions
through)
Functions of tight junctions
Figure 19-24 Molecular Biology of the Cell (© Garland Science 2008)
Dye on the apical side
Dye on the basal side
Sawada et al. Tight junctions and human diseases. Med Electron Microsc. 2003 Sep;36(3):147-56.
Figure 19-27 Molecular Biology of the Cell (© Garland Science 2008)
actin filaments
Gap junctions
Gap junctions are a specialized intercellular connection between a multitude of animal
cell-types. They directly connect the cytoplasm of two cells, which allows various
molecules, ions and electrical impulses to directly pass through a regulated gate
between cells.
A gap junction is composed of six identical connexin proteins. Each of these
six units is a single polypeptide which passes the membrane four times.
Gap junction electron microscopyGap junction freeze-fracture
electron microscopy
Figure 3. Validation of the dye diffusion assay performed with the flattened cochlear preparation.
Chang Q, Tang W, Ahmad S, Zhou B, Lin X (2008) Gap Junction Mediated Intercellular Metabolite Transfer in the Cochlea Is
Compromised in Connexin30 Null Mice. PLoS ONE 3(12): e4088. doi:10.1371/journal.pone.0004088
http://journals.plos.org/plosone/article?id=info:doi/10.1371/journal.pone.0004088
耳蝸細胞
Figure 4. Time-lapse recordings of intercellular dye transfer in WT and Cx30 null mice after fluorescent dye
was injected into a single outer sulcus cell.
Chang Q, Tang W, Ahmad S, Zhou B, Lin X (2008) Gap Junction Mediated Intercellular Metabolite Transfer in the Cochlea Is
Compromised in Connexin30 Null Mice. PLoS ONE 3(12): e4088. doi:10.1371/journal.pone.0004088
http://journals.plos.org/plosone/article?id=info:doi/10.1371/journal.pone.0004088
Epithelial organoid (acinus) formation assay:
Single cell in 3-
dimensional matrix (2%
Matrigel)
Proliferation
epithelialization
Lumen formation
Acinus
How is epithelial polarity established?
Some mutant tubule cells fail to form epithelial organoids (acini) in 3D matrix
F-actin E-cadherin Merge+DNA
Wild-type
lumen
Mutant
20 mm
Figure 19-29 Molecular Biology of the Cell (© Garland Science 2008)
How is epithelial polarity established?
RAC is a RAS-like molecule that organizes the orientation of actin filaments.
Attachment to basement membrane
Localization of Par3/Par6/aPKC complex to apical surface
Recruitment of Rac, Cdc42 (actin filament regulator)
Recruitment of Crumbs/Discs-lost (Patj)/Stardust complex
Recruitment of Scribble/Discs large/Lethal giant larvae (Lgl)
complex
Establishment of adherens junctions
Figure 19-31 Molecular Biology of the Cell (© Garland Science 2008)
Apical complexes are evolutionarily conserved
Without these "apical complexes", adherens junctions cannot form
properly, and epithelium breaks down.
This explains why some of these proteins are known tumor
suppressors :
Breakdown of epithelial structure leads to a cellular event
called epithelial-to-mesenchymal transition (EMT). EMT is
believed to be the first step of tumor malignancy, and has been
shown to be a characteristic of cancer stem cells.
The ultimate phenotype of EMT is loss of adherens
junction (E-cadherin). Many EMT-inducing factors work via
blocking E-cadherin localization or reducing E-cadherin
expression.Dlg: breast cancer, colon cancer
Scrib: cervical cancer
Lgl: reduced or loss of expression found in 75% (n=94) of colon
cancer samples.
Domain architecture of the Dlg complex proteins. This architecture
is conserved from worms to vertebrates. (PDZ) PSD-95, ZO-1, Dlg
homology domain; (SH3) Src homology 3 domain; (GUK)
guanylate kinase-like domain; (LRR) leucine-rich repeats; (WD40)
tryptophan–aspartic acid 40 residue repeat; (S) serine residues that
are conserved phosphorylation sites targeted by aPKC.
(hDlg)
(SCRIB)
(Hugl 1, 2)
Disruption of tight junctions (ZO-1 mutation) can also lead to tumor formation.
w.t. lgl-/-
w.t. lgl-/-
Basal epidermal cells in vivo
Figure 19-39 (part 2 of 3) Molecular Biology of the Cell (© Garland Science 2008)
Figure 19-40 Molecular Biology of the Cell (© Garland Science 2008)
(Basement membrane)
Figure 19-41 Molecular Biology of the Cell (© Garland Science 2008)
(層粘連蛋白)
(纖維連接蛋白)
(玻尿酸)
Figure 19-42a Molecular Biology of the Cell (© Garland Science 2008)
collagen
Laminin
Figure 19-42b Molecular Biology of the Cell (© Garland Science 2008)
Figure 19-43 Molecular Biology of the Cell (© Garland Science 2008)
Interaction between cell and basement membrane
Figure 19-46 Molecular Biology of the Cell (© Garland Science 2008)
Breakdown of basement membrane by proteases (matrix
metalloproteases) can cause disintegration of epithelium.
Hemidesmosome electron microscopy
Intestine
E-cadherin stain
Uterine
E-cadherin stain+DNA stain
LESSON II:
TUMOR STROMA
What is Stroma?
• Stroma is originally a Greek word meaning
“layer, bed, bed covering”.
• Used in biology, it refers to the connective,
supportive framework of a biological cell,
tissue, or organ. The stroma in animal tissue
is contrasted with the parenchyma.
Tissue architecture of prostate