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Simple blood test that can detect early stage cancer

Posted on March 17, 2018 | Leave a comment

A dividing lung cancer cell. Source: National Institues of Health

The Canadian Cancer Statistics estimated approximately 206,200 Canadians will be diagnosed with cancer in 2017 and 80,800 Canadians will die of cancer in 2017. In other words, about 1 in 2 Canadians will develop cancer in their lifetime, and about 1 in 4 Canadians will die of cancer. However, a cancer diagnosis fortunately does not mean a death sentence since the majority of cancers can be treated successfully if detected early. Cancer is a group of diseases characterized by the uncontrolled growth and spread of abnormal cells. If the cancer has spread, treatment becomes more difficult, and generally a person’s chances of surviving are much lower. Thus, the key to curing cancer is early detection.

Colon cancer 5-year survival rate. Data from Vogelaar et al.

For example, in colon cancer, if you detect cancer in stage four, only 11 percent of the people survive for five years. However, if you are able to detect this cancer early at stage one, over 94 percent of people will survive. Other types of cancers also have similar trends. However, unfortunately only 15 percent of people are detected at stage one, whereas the vast majority, 70 percent, are detected in stages three and four.

There are currently three best ways to screen for cancer. The first method is a medical procedure of colonoscopy for colon cancer. The second is a protein biomarkers, prostate-specific antigen(PST), test for prostate cancer. The third one is an imaging technique, mammography for breast cancer. However, they are highly invasive and require a large infrastructure to implement.

So, many scientists have researched to find better detection mechanisms for cancers, which is noninvasive, light in infrastructure, and highly specific. Dr. Jimmy Lin, a geneticist, and his research team have developed extremely sensitive blood tests, which can accurately detect the earliest traces of cancer DNA in the bloodstream. Even this technique does not use any radiation and is applicable to large population.

The blood circulatory system is crucial for us to survive, providing oxygen and nutrients to our cells, and removing waste and carbon dioxide. When cancer cells grow and die, DNA is shed into the blood system. Based on genomic sequencing technology, they were able to scan blood for fragments of DNA shed by cancers to detect these cancers early.

This technology was actually used to detect recurrence of cancers earlier than with conventional methods. As a result, the technique accurately predicted relapse in 12 of 15 patients about eight months before cancers were visualized by standard imaging method. Patients, who still have cancer DNA in the bloodstream, are at high risk of developing relapse since cancer cells that survive treatment can invade other organs as metastatic disease.

This means that the patients can get surgical intervention or therapies eight months earlier. More importantly, it means that the cancer would have grown and spread for eight months less, which is the matter of life and death for some patients. For some patients, this technique also discovered mutations that potentially causes drug resistance, which could help doctors to prescribe drugs to fight against specific mutations.

-Subi Kim

Source:

  1. Vogelaar, I. L., Ballegooijen, M., Zuber, A. G., Habbema, J. D., Kuipers, E. J. Effect of rising chemotherapy costs on the cost savings of colorectal cancer screening. JNCL, 2009, 20, 1412-1422. (accessed Mar 17, 2018).
  2. Canadian Cancer Society’s Advisory Committee on Cancer Statistics. Canadian Cancer Statistics. 2017, www.cancer.ca/Canadian-CancerStatistics-2017-EN.pdf (accessed Mar 17, 2018).
  3. National Institutes of Health. Cancer. 2018, https://www.nih.gov/about-nih/what-we-do/nih-turning-discovery-into-health/cancer (accessed Mar 17, 2018).
  4. Bardelli, A. Medical research: L Personalized test tracks cancer relapse. Nature. 2017, 545, 417-418. https://www.nature.com/articles/545417a (accessed Mar 17, 2018).
  5. Mendoza, J. Blood Test Catches Relapse in Early-Stage Breast Cancer Patients. AAAS. 2015. https://www.aaas.org/news/blood-test-catches-relapse-early-stage-breast-cancer-patients (accessed Mar 17, 2018).
  6. Murillas et al. Mutation tracking in circulating tumor DNA predicts relapse in early breast cancer. Science Translational Medicine. 2015, 7. http://stm.sciencemag.org.ezproxy.library.ubc.ca/content/scitransmed/7/302/302ra133.full.pdf (accessed Mar 17, 2018).

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Life Stress and Telomere Length

Posted on February 23, 2018 | 2 comments

Dr. Elizabeth H. Blackburn, a biochemist at the University of California, San Francisco, shared the 2009 Nobel Prize in Medicine or Physiology for her discovery of the process of telomere shortening. Her research revealed that telomeres and telomerase may play central roles in how we age. Telomeres are special segments of noncoding DNA at the very ends of chromosomes. 

The telomeres protect the ends of chromosomes from fraying. The problem is that every time the cell divides and the DNA is copied, some of that telomere get shortened until the length would hit a critical point. She also discovered an enzyme that could replenish and restore the length of telomeres, and she named it telomerase.

The shortened telomeres play a role in aging by the erosion of the DNA over time. It means that the telomeres’ length is connected to ageing and going from healthy to diseased. She revealed that telomere attrition is also contributing to physiological changes in the body such as increasing risks of getting various types of diseases, such as cardiovascular diseases, Alzheimer’s, some cancers, and diabetes.

The risks of the diseases of ageing cannot be reduced by telomerase since although increasing the telomerase decreases the risks of some diseases, the higher levels of it also increase the risks of certain and rather serious cancers such as brain tumours, melanoma, and lung cancers. So, she carried out experiments to discover ways to control our telomeres’ length and thus health, without taking cancer risks.

She discovered the relationship between perceived stress and telomere length, which clearly indicated that the more chronic stress you are under, the significantly shorter the telomeres. The results of the study are shown below, Figure2.

In addition, her further study discovered that negative thinkers who perceive their life events under greater stress were found to have shorter telomeres and lower telomerase activity. On the other hands, people, who experience their circumstances not as a threat, but as a challenge had been able to maintain their telomeres. 

This study indicates that we have control over the way we age all the way down into our cells. People’s life events and the way they perceive these events can affect on the telomeres length. Physical activity as a form of meditation may also control the shortening effect on telomeres. Therefore, telomere length wasn’t just a matter of age counted in years, but it was a matter of attitude.

People who have experienced emotional neglect, exposure to violence, or bullying consistently have shorter telomeres while tight-knit communities and lifelong friendships improve telomere maintenance. Dr.Elizabeth H. Blackburn said, ” It‘s telling us that I have the power to impact my own telomeres, and I also have the power to impact yours. Telomere science has told us just how interconnected we all are.”

The video below explains the relationship between accelerated telomere shortening and life stress. See source here.

-Subi Kim

 

References:

E. S. Epel et al. Accelerated telomere shortening in response to life stress. 2004. The National Academy of Sciences. 101:17312-17315. doi: https://doi.org/10.1073/pnas.0407162101.

Roxy, P., Chris, O., Jay, D. (2011) Introduction to Statistics and Data Analysis. Boston, MA: Nelson Education.

 

 

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Weavable Light-Emitting Fibers for Wearable Electronics

Posted on January 15, 2018 | Leave a comment

Integration of electronics into textiles (e-textiles) has emerged as a promising new technology because it can offer tremendous possibilities in many fields of science and fashion, leading to new applications and products.

Organic light-mitting fibers woven into knitted clothes. Source: The Korea Advanced Institute of Science and Technology (KAIST)

Numerous studies have been dedicated to developing the organic light-emitting fibers for wearable electronics. However, conventional fibre-based light emitting devices have limitations of their much lower emission performance compared to those fabricated on flat substances. So, a research team led by Professor Kyung Cheol Choi in the School of Electrical Engineering at Korea Advanced Institute of Science and Technology (KAIST) in South Korea has developed a simple and cost effective solution which is a fabrication technique, using a low-temperature process. Using their technique, the team successfully fabricated the thin and flexible fibre-based organic light-emitting diodes (fiber OLEDs) without any reduction in performance.

A video below briefly introduces OLED fibers. See source here.

https://www.youtube.com/watch?v=J9keKez6ryY

In the manufacturing process, eliminating the high temperature and vacuum processes is crucial since fibers such as cotton, polyester, nylon are thermally delicate. So, the research team used a thermal annealing and dip coating method in cylindrical fibers at as low temperature as possible. 

The team also designed the structure of fiber OLEDs to improve the electron injection efficiency on the fibers and to employ a low-temperature thermal annealing processable cathode, which significantly impacts on its performance. According to the researchers, their revised structure clearly exhibited high luminance and current efficiency compared to those of previously reported fiber-based OLEDs. In addition, the dip coating method at low temperature improved surface roughness and sufficiently ensured the device stability without any planarization layer.

Moreover, the technology demonstrates the scalability of the proposed fabrication scheme with diameter ranging from 300μm to 90μm, thinner than human hair. The research team ensured that the fiber OLEDs could be weavable into textiles and knitted clothes without any reduction in emission performance because their inherent empty spaces and the wavy structures enhance flexibility and stress distribution of the OLEDs.

Fiber OLEDs with different diameters. Source: The Korea Advanced Institute of Science and Technology (KAIST)

Professor Choi emphasized the versatility for application on delicate fibers by stating that the technology to incorporate display screens into our clothing is now a reality, and organic light-emitting clothes will have a significant influence not only on the e-textile industry, but also on the automobile and healthcare industries.

A video below briefly shows how wearable e-textiles may be used in future.      See source here.

Reference:

  1. Seonil Kwon, Hyuncheol Kim, Seungyeop Choi, Eun Gyo Jeong, Dohong Kim, Somin Lee, Ho Seung Lee, Young Cheol Seo, Kyung Cheol Choi. Weavable and Highly Efficient Organic Light-Emitting Fibers for Wearable Electronics: A Scalable, Low-Temperature Process. Nano Letters, 2017; 18 (1): 347 DOI: 10.1021/acs.nanolett.7b04204
  2. The Korea Advanced Institute of Science and Technology (KAIST). (2018, January 10). Fiber OLEDs, thinner than a hair. ScienceDaily. Retrieved January 15, 2018 from www.sciencedaily.com/releases/2018/01/180110101019.htm
  3. The Korea Advanced Institute of Science and Technology (KAIST). (2017, September 4). Light-emitting fibers for wearable displays. AsianScientistNewsroom. Retrieved January 15, 2018 from https://www.asianscientist.com/2017/09/tech/oled-flexible-wearable-display/

-Subi Kim

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