Apoptosis – BioQuakes

The function of the endoplasmic reticulum is to fold and secret transmembrane proteins. Proteins in cells provide a variety of functions; such as speeding up chemical reactions through enzymes, protecting the cell against disease through antibodies, and coordinating organism activities with hormones. Proteins are obviously crucial to cells.

However, recent research shows that although proteins are supposed to help cells run efficiently, in some cases, under stress, proteins can cause cell suicide, or apoptosis. Apoptosis is part of the natural cycle of a cell, but in this case, proteins are truncating the cell’s normal cycle, which can even be disease-inducing.

Licensing Information at https://commons.wikimedia.org/wiki/Category:Protein_folding#/media/File:Protein_fold.png

When environmental conditions or genetic factors around the ER go awry, a cellular stress reaction called the Unfolded Protein Response (UPR) either triggers or deactivates DR5, Death Receptor 5 Protein, which can lead to cell suicide. The two main factors which control the UPR are IRE1A and PERK. By activating XBP1, which drives expression of cell-survival genes, IRE1A promotes cell survival. PERK actives CHOP, which in turn activates DR5.

The ER activates UPR in order to alleviate cell stress and return the ER to homeostasis, but this instead can lead to apoptosis.

ER stress is central to many diseases, including neurodegeneration, type II diabetes, cancer, atherosclerosis, and liver disease. This finding is so important because now that scientists have found that IRE1A and PERK are the causes of this response, they can better study the phenomenon.

The idea that an organelle can be stressed is very interesting. I usually think of organelles as having clean structures and clean results, but this story shows that the ER can be overstressed through changing conditions and its actions will reflect this stress.

Another interesting part of this article is that when the ER activates UPR, this will either activate or deactivate the DR5, the cause of cell suicide. In science, we usually think of things as reliable and consistent, but this response to the ER can either save the kill or destroy the cell.

Finally, Cancer is a diseased caused by the over-multiplication of cells. If cell stress leads to cell suicide, then maybe scientists can use their new found understanding of the proteins involved in UPR to figure out a way to destroy cancerous cells.

Original Article

http://www.the-scientist.com/?articles.view/articleNo/40418/title/Protein-Helps-Cells-Adapt-or-Die/

Sources

http://www.ncbi.nlm.nih.gov/pubmed/21266244

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3290993/

http://carcin.oxfordjournals.org/content/21/3/485.long

Taken by: USCPSC

Cancer is one of the most well known diseases, yet it is one of the hardest to treat. The research of different treatments for cancer is ongoing and innovative. According to a recent study in South Korea magnets may be the next step in cancer treatment. A way for magnets to assist the body in targeting and killing off cancer cells has been discovered and is being researched and developed.

A problem with current cancer treatments like chemotherapy or radiation therapy is that they can only be targeted to a certain extent. With this experimental form of cancer treatment, using magnets, the body’s natural functions are used to kill the cells in a tumor. The human body naturally goes through a process called apoptosis, or the process of programed cell death. Apoptosis is used by the body when it is first developing allowing fingers and toes to grow individually, and it is used daily to kill off skin cells that have been damaged by weather. The researchers in South Korea are using this process to target and kill off the cancer cells.

The researchers applied zinc-doped iron oxide nanoparticles to colon cancer cells. This allows for the cells to naturally bind with antibodies, which then bind to the death receptors on the cancer cells. The researchers then applied a magnetic field, which caused the death receptors to send out a signal telling the system to attack the cell. When this occurs chemicals are sent out and the cells of the tumor that had zinc-doped iron oxide nanoparticles on them were killed.

Sadly this innovative new cancer fighting technique has its downsides. In their experiments only half the exposed cells were killed although none of the cells they weren’t targeting were harmed. And when this method was tested on zebra fish some grew abnormal tails, which means that this method may be innovative but it still has plenty of testing to go through before it will be used on humans.

BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: Apoptosis

Protein: A Cell’s Hero or Villain?

Magnets: Fun Toy or Deadly Tool?

Archives