Carbon Nanotechnology and Targeted Cancer Therapy

I came across this fairly new subject last year because my organic professor was slightly obsessed with biology as well. She was full-blown into organic synthesis but on her down time she researched biology topics because she found them interesting. She always talked about the fairly new application of carbon nanotechnology in biological applications. We even had the option to write a research paper that applied this technology or to take a final, naturally, I chose the paper. In brief these are cylindrical structures that are composed primarily of carbon. They have a diameter of 1-nanometer and they are stronger than steel. They have unique electrical and thermal properties. They can be classified as single-walled or multi-walled. A single-walled carbon nanotube is kind of like a small straw that is made up of chicken wire and multi-walled is a like a straw within a straw. These nanotubes can vary in length and how many nanotubes are nestled within one another. 

They are starting to be used in targeted cancer treatments because of their unique properties. Many cancer treatments are insoluble in water and have harmful health effects. The benefit with using carbon nanotubes is that these types of treatments can be conjugated to the nanotube. These nanotubes have a needle-like shape that allows for high cell permeability that the anti-cancer drug would not have since they are insoluble. The high permeability of the nanotube means that it can penetrate tumor cells and deliver the drug directly into the cell. This helps reduce the toxic health effects as well as fixes the problem with the insolubility of drugs when they are alone. 

In Combination of drug-conjugated SWCNT nano carriers for efficient therapy of cancer stem cells in a breast cancer animal model, researchers developed a single-walled carbon nanotube (SWCNT) that was functionalized with polyethylene glycol (PEG) and conjugated with CD44. PEG helps the biocompatibility of the carbon nanotube meaning that the tube has a higher chance in being accepted by the body rather than rejected. CD44 is an antibody that binds to CD44, a receptor protein that is highly expressed within patients with breast cancer. This antibody makes the nanotube highly specific to where it interacts. These nanotubes were further manipulated to be able to hold a high amount of chemotherapeutic drug and to have a pH-release response mechanism. Since a tumor is an acidic environment compared to the rest of the body, it wouldn't be beneficial for the nanotube to release the medication as soon as it entered the body. This way the amount of drug is optimized and released at the targeted location. 

In the mice models, the SWCNT were conjugated with Salinomycin or Paclitaxel. It was found that the therapeutic effects were greatest when both drugs were conjugated within the SWCNT versus the therapeutic benefits without administration with the SWCNT or just one of the drugs bound to the SWCNT. The benefits included specific targeting of both the cancer stem cells and the breast cancer tumor and destroying these cells. This is a promising finding because it offers a better mode of administering chemotherapy drugs. A lot of chemotherapy drugs that cancer patients take target all rapidly growing cells like your hair, stomach lining, ect. This is why there is increased nausea and hair loss. If these application could be applied to humans then it would not only decrease these adverse health affects but it could potentially increase the amount of drug getting to the tumor or cancer stem cells allowing for a better chance at completely getting rid of the cancer an individual has. What are your thoughts? Do you believe that this technology could be beneficial or adversarial to human health? What do you know about this unique nanotechnology?  

For your pleasure: http://www.sciencedirect.com.ezproxy.shsu.edu/science/article/pii/S0168365916300499

Smart Phones Can Detect Cancer?!?!

Today I figured that I would switch things up a bit. Instead of talking about the genetic basis of a disease or DNA methylation, I found this really interesting article on a new smart phone technology. Smart phones are the epicenter of many people's lives. You talk on them, play games, Instagram stalk that hottie from your chemistry class. There are many productive things you can do with them as well, like word processing or view 3D schematics. As the technology advances and more people come out with more apps, the more productive the smart phone becomes. Researchers at Washington State University have found a way to make your smart phone even more productive by transforming it into a mobile laboratory for cancer screening. WHAT?!

These researchers combined the smart phone technology with spectroscopy. Spectroscopy, especially mobile spectroscopy, has been used previously within the medical field for a diagnostic test/screening. However, the spectrophotometer is very bulky and the sample would have to be sent into a lab, which probably has backlog. This makes a waiting process brutal, especially when screening for something like cancer. Mobile spectroscopy has been previously developed, so it isn't a new or novel idea. However, these were very slow and could only screen one sample at a time. What makes this spectrophotometer different from the others is that it can analyze eight samples at once and allows for quick field testing. 

It works by first subjecting the sample to a test called enzyme-linked immunosorbent assay (ELISA). ELISAs work by having a certain antibody for the protein of interested immobilized on a solid surface, usually a 96-well plate. The sample is then pipetted into these wells and incubated to allow for the antibody to bind to the target antigen. Once incubated, the plate is washed and a detection antibody is added to the wells. The excess detection antibody is removed horseradish peroxide (HRP) conjugate is added to the wells that binds to the detection antibody (this is another antibody that had the HRP bound to it). The plate is then incubated and then washed to remove this HRP conjugate then a substrate solution is added to the wells. This substrate reacts with the HRP conjugate to elicit a color change. This is then read by the spectrophotometer. 

The smartphone spectrophotometer is programmed to pick up on interleukin-6, which is a biomarker for a slew of cancers. When tested out using laboratory-controlled samples, they achieved 99% accuracy. This technology will be great for work out in the field. Patients wouldn't have to wait as long for test results and many other unnecessary testing could be avoided if this technology is utilized out in the field. How do you feel about this technology? Could there be other potential uses for mobile spectrophotometers? 

For further reading if you are interested: http://www.sciencedirect.com/science/article/pii/S0956566316308983

MethylAGING

Aging is a inevitability that each individual has in common. We all get older and that is something that cannot be changed, unless we get bitten by a vampire and in that case we have immortality. However, this is real life and not fiction. Age of an individual is something that police also looks for when they are explaining a victim or suspect that they are looking for. If there is a body found at a crime scene anthropologists can approximate age by looking at how the teeth are formed and various other osteal markers. However, predicting age without a body present is sometimes hard when you are dealing with a suspect that is alive and the only means of identification are eye-witnesses (sometimes you don't even have that). What if I told you that your DNA could predict how old someone is? You would probably look at me like I'm crazy, however scientists at the Korea Research Institute of Bioscience and Biotechnology have found a way that can age an individual based on the methylation patterns that are present within DNA.

Unfortunately studies have already shown that looking at methylation patterns of DNA could predict age of that individual but it requires a large amount of DNA that forensically is not possible to collect at a crime scene. However, the use of pyrosequencing can be utilized with just 2.5 to 10-ng of starting DNA and is one of the most reliable methods to use to obtain DNA methylation data. This allows the DNA to be quantified and the methylation patterns mapped with just small amounts of DNA that you would normally come into contact with at a crime scene. 

After analyzing the HumanMethylation540 BeadChip the researchers found that the genes ZNF423 and CCDC102B becomes hypomethylated with age while ELOVL2 becomes hypermethylated with age. These three sites were chosen because they were believed to accurately predict age together rather than alone because they all code for proteins are affect aging and they are gender-neutral, which was one of the criteria for the researchers since gender can affect some aspects of aging like balding. 

After looking at the methylation patterns of each of these sites, a linear regression model was created and tested for accuracy . They found that this method could accurately predict age plus or minus 6.8 years, which is way better than not knowing how old the suspect is in the first place (just my opinion). 

There are some limitations to this study. The researchers preformed their experiments using blood that could be found at a crime scene. However, it is known that methylation patterns are tissue specific and there needs to be further research on how different CpG sites are methylated throughout these tissues before where universal methylation markers can be identified. On the other hand, disease plays a role in the deregulation of methylation posing issues that are a problem in determining age by using this method. 

Fragile X

As you all know, sex is determined by your X and Y chromosomes: you have XX if you are a female and XY if you are a male. Many people do not know, however, that your X and Y chromosomes do more than just determine what sex you are, they also carry genes that encode for certain proteins as well. With every gene, there is a potential for something to be inherited that causes a dysfunction. Fragile X syndrome is an example of a dysfunction caused by inheriting an abnormal gene. This disease encodes for a gene that is located on the X chromosome and can be inherited through a stroke of bad luck.

Fragile X syndrome (FXS) is an X-linked dominant disorder that is characterized by mental disability, autistic-like behaviors, developmental delay, vulnerability of seizures, and macroorchidism in males. Being an X-linked dominant disorder means that you only need to inherit one bad copy of the gene for this disease to be expressed. This disease is caused by a single mutation in the Fragile X Mental Retardation 1 gene (FMR1). In normal functioning people this gene is expressed allowing for the production of Fragile X Mental Retardation Protein (FMRP); these individuals express normal mental capabilities. However, the mutation within FXMD1 causes silencing of gene expression which ultimately leads to cognitive impairment and other disease symptoms.

To clarify, FXS is caused by gene expansion of FMRI. The CGG repeat sequence located at the 5' untranslated region (UTR) gets expanded leading to hypermethylation of the repeat sequence and the promoter region. This hypermethylation plays a part in not allowing for translation of the FMRP. The severity of the disease can be in part caused by how many expansions are added to the CGG repeat sequence. The normal allele has about 5-44 CGG repeats, the borderline allele has 45-54 repeats, premutation (PM) allele has 55-200 repeats, and the full mutation (FM) allele has greater than 200 repeats. Within these repeats are AGG interruption; this allows for the strand to be anchored during replication where they won't slip. PM alleles do not have these AGG interruptions causing the DNA to be unstable when it gets inherited to the offspring; the possibility of this turning into a FM is very high and there is a change that the baby will show signs of this disease. With that being said, carriers of PM alleles do not show any signs of FXS, while individuals who carry the FM allele will show signs and symptoms of FXS.

Another factor in the severity of FXS symptoms is the sex of the individual. Males tend to express the disease more often (1 in 4000) since males only posses one X chromosome. Males can only inherit this disease from their mothers since they receive the Y chromosome from the father. If they carry the full mutation then they will always be infected. However, females posses two X chromosomes and only about 1 in 8000 females show prevalence of this disease. Due to random X-inactivation, which is when one of the X chromosomes is randomly deactivated to stop females from expressing twice as many X chromosome genes as males do, females who carry the FM allele, can go their entire life time without ever expressing FXS. The severity is inversely related to the activation ratio between the  normal FMR1 allele and its product meaning that however much FMRP is produced, correlates how bad the disease will be if FM FMRI allele is present.