* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Lecture 22: Cancer II and Cell Junctions
Survey
Document related concepts
Cell membrane wikipedia , lookup
Tissue engineering wikipedia , lookup
Cytoplasmic streaming wikipedia , lookup
Endomembrane system wikipedia , lookup
Cell encapsulation wikipedia , lookup
Signal transduction wikipedia , lookup
Organ-on-a-chip wikipedia , lookup
Cell growth wikipedia , lookup
Cell culture wikipedia , lookup
Cellular differentiation wikipedia , lookup
Cytokinesis wikipedia , lookup
Extracellular matrix wikipedia , lookup
Transcript
Cancer II Six ways of losing the remaining good copy of a tumor suppressor gene When proto-oncogene becomes overactive it becomes an oncogene Myc Gene Amplification Mitogens stimulate G1-Cdk and G1/S-Cdk activities Ocogene collaboration in transgenic mice Viruses May cause Cancer Papillomavirus causes warts and subverts the control of cell division Pap smears normal abnormal invasive How papillomaviruses are thought to give rise to cancer of the uterine cervix Activation of cell proliferation by DNA tumor virus Sequence of genetic changes underlying the development of a colorectal carcinoma Each tumor will contain a different set of mutations Effect of ionizing radiation on normal and cancer cells Cell Junctions, Cell Adhesion, and the Extracellular Matrix Chapter 19 Cross sectional view of intestinal wall Tracer molecules can not cross tight junctions Structure of tight junction Electron Micrograph of tight junctions Model of tight junction Claudins are main component of sealing strands Anchoring junctions in an epithelium Anchoring junctions are formed by proteins Cadherins connect actin filaments of different cells DVD Clip 82 Desmosomes and hemidesmosomes both link to intermediate filaments Cadherins also bind intermediate filaments together Integrins link extracellular matrix to cytoskeleton Size of gap junction channel can be determined with fluorescent molecules of different sizes A Gap junction connexon is made up of 6 transmembrane connexin subunits Images of gap junctions The permeability of gap junctions can be regulated dopamine treatment reduces permeability of gap junctions to a fluorescent dye Summary of cell junctions found in the cell Summary of cell junctions found in the cell In plant cells plasmodesmata perform many of the same functions as gap junctions View of plasmodesmata Structure of Cadherin – responsible for cell to cell adhesion in vertebrate cells Ca2+ is required to establish cell to cell connection through cadherin Three mechanisms that mediate cell-cell adhesion cadherins least common Cadherins allow cells to sort themselves Catenins join cadherins to actin filaments in adherence junctions Summary of junctional and non-junctional adhesive mechanisms