Cell Bio Report 1
Lab Report 1: Subculturing Adherent Cells
Fibronectin, integrin alpha 3, and actin are all involved in cellular adhesion at both the cellular and molecular levels. Integrins are the primary trans-membrane receptors that mediate dynamic interactions between the extracellular matrix and the actin cytoskeleton whenever a cell is motile. Integrins bind to the extracellular matrix and link to the actin cytoskeleton via a shirt cytoplasmic tail; they also help determine cellular binding specificity because the extracellular domain of integrins recognizes a diverse array of matrix ligands such as fibronectin, collagen, and laminin. Generally, integrins bind to a specific motif within the matrix protein; specifically 9 different integrins may bind fibronectin. Ergo, cells that adhere to fibronectin possess matrix-induced adhesions which contain a myriad of integrins have unique effects on cell adhesion and motility. 1
Growth factors and cellular proliferation are inescapably intertwined – without growth factors, the cell would not be able to grow larger, synthesize more DNA, or undergo mitosis. Cell proliferation is the spread of cells as they grow in size and in number. There are a plethora of check points and chemical regulations in place to ensure that cell proliferation is controlled, but sometimes these checkpoints are ignored or overridden by cells and thus we see excess cellular proliferation – a good example of this is cancer cells like the HeLa S3 cells that we have been working with in the laboratory. When a cell is not regulated, access to the growth factors can be extremely detrimental as they allow these cells to continue growing unchecked. Thus, growth factors, which are so vital to healthy cellular proliferation, can be turned into an enemy of healthy cells when they are fed on by unregulated, and often cancerous, cells. 2
Cancer cells take advantage of anchorage-independent growth and loss of contact inhibition because these particular characteristics
Fibronectin, integrin alpha 3, and actin are all involved in cellular adhesion at both the cellular and molecular levels. Integrins are the primary trans-membrane receptors that mediate dynamic interactions between the extracellular matrix and the actin cytoskeleton whenever a cell is motile. Integrins bind to the extracellular matrix and link to the actin cytoskeleton via a shirt cytoplasmic tail; they also help determine cellular binding specificity because the extracellular domain of integrins recognizes a diverse array of matrix ligands such as fibronectin, collagen, and laminin. Generally, integrins bind to a specific motif within the matrix protein; specifically 9 different integrins may bind fibronectin. Ergo, cells that adhere to fibronectin possess matrix-induced adhesions which contain a myriad of integrins have unique effects on cell adhesion and motility. 1
Growth factors and cellular proliferation are inescapably intertwined – without growth factors, the cell would not be able to grow larger, synthesize more DNA, or undergo mitosis. Cell proliferation is the spread of cells as they grow in size and in number. There are a plethora of check points and chemical regulations in place to ensure that cell proliferation is controlled, but sometimes these checkpoints are ignored or overridden by cells and thus we see excess cellular proliferation – a good example of this is cancer cells like the HeLa S3 cells that we have been working with in the laboratory. When a cell is not regulated, access to the growth factors can be extremely detrimental as they allow these cells to continue growing unchecked. Thus, growth factors, which are so vital to healthy cellular proliferation, can be turned into an enemy of healthy cells when they are fed on by unregulated, and often cancerous, cells. 2
Cancer cells take advantage of anchorage-independent growth and loss of contact inhibition because these particular characteristics
Cited: 1 Hynes, Richard O., and Kenneth M. Yamada. "Integrins in Cell Migration."Cold Spring Harbor Perspectives in Biology. Cold Spring Harbor Laboratory Press, 01 Oct. 2011. Web. 18 Feb. 2015. <http%3A%2F%2Fcshperspectives.cshlp.org%2Fcontent%2F3%2F9%2Fa005074.full>. 2 Coroneos, Emmanuel, Michael Martinez, Siobhan McKenna, and Mark Kester. "Differential Regulation of Sphingomyelinase and Ceramidase Activities by Growth Factors and Cytokines." Differential Regulation of Sphingomyelinase and Ceramidase Activities by Growth Factors and Cytokines. The Journal of Biological Chemistry, 21 July 1995. Web. 18 Feb. 2015. <http://www.jbc.org/content/270/40/23305.full.pdf+html>. 3 Martin, Tracey A., Lin Ye, Andrew J. Sanders, Jane Lane, and Wen G. Jiang. "Cancer Invasion and Metastasis: Molecular and Cellular Perspective."Madame Curie Bioscience Database. National Center for Biotechnology Information, 2013. Web. 18 Feb. 2015. <http%253A%252F%252Fwww.ncbi.nlm.nih.gov%252Fbooks%252FNBK164700%252F>.