Category ME L24 Comparative Significance of Cell Spreading and Division in

Monolayer Reform

Abstract The reformation of a contiguous cell monolayer is a multifaceted process

that involves an intricate coordination of two general processes: cell

division and cell spreading. In response to interruptions in a cell monolayer,

cell division, a well-studied process employed by cells to reproduce,

works in conjugation with cell spreading, a gradual flattening and

locomotion of cells, to restore lost contiguity.

This study focuses on the comparative significance of cell division and cell

spreading in monolayer restoration. Monolayers of PtK2 Potorous Kidney

Epithelial Cells were treated with the drugs Aphidicolin and EHT-1864 to

selectively inhibit cell division and cell spreading, respectively, and were

struck to introduce a disruption in contiguity. The initial rate of monolayer

restoration in non-spreading monolayers was 71% slower than in non-

dividing monolayers. However, over a 65 hour period, the reformation rate

in non-spreading monolayers doubled while the rate halved in non-dividing

monolayers. Interestingly, a stain analysis of intracellular dynamics

indicated an upregulation of microfilament production in non-dividing

monolayers while incidence of mitoses remained constant between non-

spreading monolayers and the control.

The results suggest that cell spreading is a key component in initial

monolayer restoration while cell division requires time to substantially

contribute to reformation. Also, the inhibition of cell division appears to

promote cell spreading, but not vice versa. Monolayer reformation,

although an intricate process in itself, plays an integral role in other, more

complex process. Studies of monolayer reformation are often incorporated

in wound surrogacy analyses and have numerous implications in wound

healing, ulcer treatment, and skin cancer care.

Bibliography Namekata, Kazuhiko, Yasushi Enokido, Kazu Iwasawa, and Hideo Kimura.

"MOCA Induces Membrane Spreading by Activating Rac1." The Journal Of

Biological Chemistry 279 (2004): n. pag. The Journal of Biological

Chemistry. Web. 2 Jan. 2010.



Seluanova, Andrei, Christopher Hine, Jorge Azpurua, Marina Feigenson,

Michael Bozzella, Zhiyong Mao, Kenneth Catania, and Vera Gorbunova.

"Hypersensitivity to contact inhibition provides a clue to cancer resistance

of naked mole-rat." Proceedings of the National Academy of Sciences of

the United States of America 106 (2009): n. pag. PNAS. Web. 2 July 2010.





Shutes, Adam, Cercina Onesto, Virginie Picard, Bertrand Leblond, Fabien

Schweighoffer, and Channing Der. "Specificity and Mechanism of Action

of EHT-1864, a Novel Small Molecule Inhibitor of Rac Family Small

GTPases." The Journal Of Biological Chemistry 282 (2007): n. pag. The

Journal of Biological Chemistry. Web. 3 Jan. 2010.



Small, J., Theresia Stradal, Emmanuel Vignal, and Klemens Rottner. "The

lamellipodium: where motility begins." Trends in Cell Biology 12.3 (2002):

112-120. ScienceDirect. Web. 9 July 2010.



Snyder, Ronald, and James Regan. "Differential Responses of Log and
First Previous Next Last