Team:GreatBay SCIE/IHP
Intro
Breast Cancer is one of the most prominent cancer present in females. In 2020, 11.7% of the newly diagnosed cancer cases are breast cancers, largest among the 36 cancer. Among women, 24.5% of the cancer cases were breast cancer, and 15.5% of death is caused by breast cancer as well. Stage I breast cancer can be cured with surgical operations; surgeries involves the removal of breast and lymph nodes, in some cases, some chest muscles have to be removed as well. In later stages chemotherapy and radiotherapy have to be applied as well. However, Chemotherapy and radiotherapy are harmful to the body, causing problems such as falling hair.
Understanding the Problem: Clinical & Laboratory Methods
Clinical
We wish to understand breast cancer not only from statistical perspective, but also from the doctors and the patients; this could help us understand breast cancer in a more practical approach.
Highlights:
To understand how breast cancer is treated clinically, we interviewed doctors who are breasts cancer specialists and also with a breast cancer screen company. In these interviews, we discussed the limitations of current treatment and also their view of good treatments.
Interviewing with the doctors we talked about targeting drugs: they are expensive in price, still have issues with stability and specificity. In addition, we talked about surgeries: Mastectomy and Lumpectomy. Lumpectomy (Breast conserving surgeries) is considered to be healthier for the patients but it is not promoted in China, with a breast-preserving rate of only 22% compared to that of 80% in western HICs. This is much due to lack of facilities and conserving mindset of many doctors.
The worst problem of all is lack of knowledge of breast cancer, only 5% of the population in China screens for breast cancer which caused most cases to be discovered during late stages, which is harder to treat.
Interview with Doctors, Breast Cancer Specialists
Dr. Nong, from Peking University Shenzhen Hospital.
Dr. Zhou, from Shenzhen Nanshan Hospital
Dr. Lu, from Xinhua Hospital.
When asked about treatments for breast cancer, Dr Nong spoke to us about monoclonal antibodies and ADC drugs. They are the two most frequently used drugs to treat HER2 positive breast cancer. She also revealed that the cost of targeted drugs is expensive, especially for certain imported drugs. The most commonly used monoclonal antibody is Trastuzumab. But according to Dr Nong, the price of Trastuzumab is high, with approximately 5500 RMB each. Hoping to explore more about the cost of Her-2 positive breast cancer treatments, we connected with Dr Zhou. She told us that Her2-positive patients who need targeted drugs might need 200,000RMB, which is a significant amount of cost for general families. She also claimed that although antibody-conjugate drugs exhibited great effectiveness, there are certain limitations. Large molecules like antibodies have immunogenicity which are likely to trigger an unwanted immune response in bodies. Moreover, along with the transport, there is a possibility that drugs are disassociated with the antibody, which might accidentally kill normal cells. Dr Nong expressed her high expectations for a drug delivery system with high specificity and stability.
Besides drugs, we've also talked about surgeries: Mastectomy and Lumpectomy (breast-conserving surgery). Doctor Lu gave our team an online lecture about these two surgeries. In 2018, in breast cancer treatment, the proportion of breast-conserving surgery in China was only 22%, far lower than that of 80% in European countries as well as in the US. We also learned that doctors tend to avoid mastectomy which may result in appearance defects for females. Breast cancer doctors will seek the best way to do breast-conserving surgeries. However, these types of surgeries are coupled with radiotherapy to ensures all the breast cancer cells are killed. But things aren't always done this way, doctors that are more conservative in many Chinese second or third-tier cities are more likely to take Mastectomy surgery as their first choice. Moreover, some small hospitals cannot provide sufficient equipment for radiotherapy, so they cannot perform breast-conserving surgeries. From another perspective of things, we learned that patients generally pay little attention to breast health from the doctors: they rarely check-in hospitals and are not aware of self-checking at home, which makes breast cancer a substantial potential risk for people. Overall, this lecture gave us an idea that hospitals and communities should promote breast-conserving surgeries in China.
Although there are many treatments for breast cancer, all three doctors claimed that 'early screening and early treatment is the best 'cure' for cancer. Breast cancer screening was free, but most people are unaware of it and don't check regularly.
From the interview with the doctors, we could grasp much information that would later help us identify the problem. (See Problems Identified🔍)
Aisono, a breast cancer screening company.
From the information given by the doctors, we were curious and interviewed a breast cancer screening company.
From our talk, they told us that in China, only 5% of the female goes for breast cancer screening and in Shenzhen, only 150 thousand out of the 20 million people screens for breast cancer. Some part of it is due to lack of sonographers registered in China: only 140,000, which is far from enough to provide screening for general public in China.
This is where Aisono found opportunity and market, they developed machines to automate the process of breast cancer screening, using artificial intelligent to analyze sonographs to be able to spot tumors during early development.
"We believed that the future of public health lies in prevention, not in treatment."
This idea also inspired our Public engagement part of the project. (see Problems Identified🔍)
Laboratory
Other than surgeries, drugs and chemicals play an important part in treating breast cancer. Drugs however, aren't developed in hospital beds, they are tested in labs by researchers and scientists. So we started a series of interviews and discussion to talk about the research aspect of treating breast cancer.
Highlights
In order to develop and formulate our project, we interview specialists to learn about pharmacy research.
Limitations of current drug treatments lies in the level of toxicity and specificity. We learned about how Antibody drugs tackle these issues and slowly formulated our project. We also interviewed with pharmaceutical companies to learn about the process to validate our design, this include in vitro tests using cancer cell lines. On a broader perspective, we learnt that most pharmaceutical companies aim at improving existing platforms of drug development and few choose to develop innovative drugs.
Dr. Qiu
We interviewed Dr. Qiu (Clay Qiu), who is currently working in a pharmaceutical company in Suzhou, and specializes in areas accociating with antibodies drugs.
From Dr. Qiu, we learned that there are currently 4 types of targeting therapy for HER2 positive breast cancer (H2BC).
- Kinase inhibitors
- Antibody drugs
- Antibody Drug Conjugates
- CAR-T Therapy
(See more in Description)
We also discussed the relationship between drug toxicity and targeting ability of a targeting drug. Dr. Qiu told us that, as for a cancer targeting drug, stronger (more toxic) does not mean better. The more you do harm to the tumor, the more you do harm to the body. Many ADC type drugs were halted during clinical phase because their side-effects were too strong.
"We have to strike a balance, that is, how to avoid killing normal tissue cells while killing cancer cells as much as possible"
We also learned that Doxorubicin and Maytansine are two types of chemicals used in targeting drugs.
Furthermore, we continued our discussion onto current obstacles in treating breast cancer. Dr. Qiu stated that, even for HER2-positive cancer patients, not all cancer cells overexpresses HER2, thus killing only the HER2-positive cells might not be as effective we think.
We also asked Dr. Qiu about how drugs could remain intact during circulation inside the body, a factor to consider mentioned by our instructor Dr. Zong. Dr. Qiu told us that past targeting drugs, uses antibody which is a stable factor present in the body. An example is people using FC domain of the antibody in ADC drugs, by binding chemicals onto this domain, their high affinity for each other would allow the drug to leave by exoplasmosis after being endocytosed by the normal tissue cells.
At last we asked the question:
What are the characteristics of an ideal cancer treating drug?
Dr. Qiu's answer is summarized in the following:
"First is highly specificity, this is the basis for increasing toxicity of the drug. However, after decades of rearch in chemotherapy, scientiest tried many drugs and chemicals but so far we can conclude that monotherapies are just not enough to cure cancer; the micro-environment of the tumor tissue is too large to neglect drug resistence. Now, people are trying out combined methods, immunotherapies and and other therapies to compensate the drawbacks of many treatments."
(Dr. Qiu also guided us during our idealation and laboratory stage, which you can find in Problems Identified🔍 & Ideate and Design.)
Pharmaceutical companies
We also interviewed several pharmaceutical companies, to understand the current state of drugs as well as the process of drug production.
Innovent 信达生物
Through our communication with Innovent, we learnt that only a few of the company paid attention to developing new drugs in China. Most of the company actually focused on chemistry manufacture and control, which is called CMC department. This department utilizes existing drug producing methods and expands the quantity and quality within the existing platformed protocol, modified them to obtain the larger yields, higher quality controllable products.
制药公司2 & 3
@蔡雨桐 这里写一下你们制药公司采访到的内容以及你感觉what we learned.制药公司采访
- 简述一下制药公司对两种不同药的态度↓
- 简述一下学到的制药流程
- 简述一下in vitro实验的重要性。
这里我想把另一个采访的公司留到后面project ideate的时候写，因为这两个公司采访都是些了制药流程以及我们需要in vitro实验，所以我想说留一个公司 是看了我们项目的 并且给我们提出了意见，让我们更好的设计实验这样子。
制药公司3
Questionnaire
Highlights
In order to confirm some of the problems mentioned by doctors and companies. We sent out a questionnaire. The results indicated a consistency for need of cheaper drugs for breast cancer. The breast cancer presented the public's lack of knowledge of breast cancer.
We also sent out questionnaires investigating the opinions on current targeted drugs; our audience included the general public, breast cancer patients and their relatives.
In our survey, we wish to inquire about people's opinion on the price of the drug, as this is very related to the public as well as patients.
From our discussion with the doctors we came to an understanding that drugs for treating breast cancer are expensive. We wanted to see how other people, people who actually lives in society (unlike us students) think about it. So one of the question was about the affordability of breast cancer drugs. The results were reasonable: more than 70% of the patients’ relatives believe that the price is quite expensive that some households will be unable to pay the bill over a long time (Fig. 1), while more than 80% of the general public holds the same opinion(Fig. 2). So, it would be very understandable when 90% of our respondents said that they hope for a lower priced drug (Fig. 3)
F1, 2 & 3
The doctors we interview told us the current awareness of breast cancer were low, we still held questions about that, so also sent a questionnaire to gather information on the public’s understanding of breast cancer, including its precaution, transmission pathways, methods for breast examination etc.
Breast self-examination is probably the most convenient and efficient way for the diagnosis of breast cancer at an early stage, and with medical intervention, a high survival rate can be achieved. The examination itself is a rather simple task which includes rubbing the breast and checking for abnormal bumps, though from our results, more than 70 recent of the respondents do not known how to do the examination(Fig.4).
F4
We have also asked our respondents to identify some of the common method for breast examination for preventing cancer that are done in hospitals, such as X-ray examination and B-scan ultrasonography. The results shows the B-scan is the most widely known examination methods, while more than 36%of the people could not identify any examination method.(Fig.5)
F5
For the transmission of the cancer, our respondents were asked whether they think breast cancer can be past by breast feeding (It obviously cannot!) However, the result showed that nearly a thirds of the people chose the wrong answer.
Summary:
A lack of awareness of the examinations that could prevent cancer development was shown. Besides there are some misunderstandings about breast cancer that should have been clarified. It is to our greatest pity that breast cancer, the disease that is potentially related to every woman and man, was currently not well understood by most of our respondents. Thus, we decided to include the publication of breast cancer and its prevention as a major part of our project in our Public engagement section.
Problems Identified🔍
Price
One of the main focus of pharmaceutical companies is to lower the price of the drug. As this can be more appealing to the general public. However, even after over 30 years of development, current price of antibody drugs remains high, as they are hard to produce and lack variation (For example, triple negative breast cancer cannot be treated with antibody drug as it does not have any targetable receptors for antibody.)
Toxicity & Side Effects
Chemotherapy although is the most mature type of drug treatment (developed in the 40s), it deals immense health damage to the patient.
Targeting drugs is the cornerstone to precision medicines. However, many current targeting drugs, especially ADC type, have issues regarding high toxicity. After talking with Dr. Qiu, we found out that there are currently only two ADC drugs approved by the FDA: TDM-1 and DS8201-a. Other drugs like MEDI4276 are all halted during the clinal phase due to high toxicity.
https://www.cancer.gov/about-cancer/treatment/types/targeted-therapies/targeted-therapies-fact-sheet
Specificity & Variation
Specificity is important, it is the foundation of targeting drugs. One of the most needed features of an ideal drug, from our interviews with doctors, is high specificity. Because this not only means that it has reduced side effects but also high effectiveness. Maintaining high specificity is key in our design.
Antibodies lack variation, as it can only target known receptors.
Stability
Another problem previously mentioned by Dr. Qiu is stability. However, when we started thinking about this problem, we have already begun considering aptamers. Aptamers are ssDNA strands which are much easier to degrade in the blood, this forced us to consider methods to modify aptamers to increase stability which can be seen in Ideate & Design.
Lack of awareness
After talking and interview with doctors and specialist, we realized that curing cancer is incredibely hard. It's is not an acute diseases but rather a chronic one most of the time. Diseases like breast cancer have no vaccines, thus the best way to prevent this disease is to live a healthy life; or treat it as early as possible. However, the current state of public knowlege with breast cancer worries as, as seen from the questionaire. Hence, we wish make awareness about breast cancer.
Ideate & Design
Highlights
We confirmed our idea and design with many of previous experts we interviewed, and were instructed on production of nanoparticles, culture of cell lines and methods for testing out the drugs.
Reflecting on the problems we identidied, we went on to research about Aptamers, an idea proposed by Dr. Qiu and mentioned in our discussion with Pharmaceutical Companies.
Aptamers are ligands that can bind to molecules, but instead of composed of proteins (like antibodies), it is purely ssDNA. The weak interaction forces between the nucleotides allow them to fold into unique structures. Aptamers have many advantages over antibodies:
Comparing the advantages of aptamer against antibodiesCharacteristicsAptamersAntibodiesImmunogenicityLowHighInternalizationFasterLow EffiencyModificationEasily ModifyHard to modifyBatch-to-Batch VariationHigh Uniformity of ProductLow Uniformity of ProductProductiong & Development CostLowHighProductiong & Development TimeShortLong
We also consulted with GreatBay_SCIE 2020, as their project is also regarding aptamers, though of different use. They advised us that we shouldn't focus too much SELEX selection,as they've already done so last year. They think the potential of aptamer lies in its ability to be modified and utilized easily; they advised us that spending time on how to implementing the aptamer, improving existing aptamers perhaps would be a better option for us.
To improve specificity even further, with our knowledge of cancer, and research we happen to encounter a literature to make use pH-sensitive aptamer, which we used in our design. This allowed our aptamer to gain higher affinity under low pH near tumor tissue, which indirectly increases the specificity of our drug.
Another problem we encountered was that aptamers were only a delivery system, we don't actually know which drug to use is most effective or suitable. Dr. Lu advised us to use Doxorubicin (DOX), which is used many times in innovative drugs and past literatures; it can be considered to be a model drug for testing our cancer curing methods.
Advice from Dr. Wei on NP(包含解决的stability的方法) (加南科大做实验指导)
At last, we presented our design to previous experts to receive feedback.
We presented to the doctors and although all three doctors are not experts in drug design, they all think an aptamer-nanoparticle-based drug delivery system is promising in the future. One doctor argued that the need for drugs to treat HER2-positive breast cancer has always been there. Secondly, currently, there are no targeted drugs using aptamers on the market, so our project is innovative.
The pharmaceutical company told us that our project is the front research of developing new pharmaceutical methods with potential. By using aptamer as the guider, this variety of ADC drugs is still not on market, there is still a gap to be filled.
The other Pharmaceutical company also advised us how to prove our drug to be valid. Although, limited by iGEM, we cannot go into any clinical phase, the company introduced to us in vitro methods to prove the validity of our drug. They say that our validity test must include results that the drug is effective against cancer cell line. For our current progress, they just advised us to consider things like cytotoxicity assay, pharmacokinetics, using algorithms to simulate potential toxicity. Though we only chose to do cytotoxicity assay due to time, their advice was invaluable.
Dr. Qiu then instructed us on culturing cells. He advised several cell-lines for us to use and guided us through steps of subculture and preservation.
We cultivated our cells at ShenZhen University and the students there helped us carry out our experiments.
Dry Lab
Structural Modeling
For the structural modelling part, in order to make our model of aptamer binding with protein become visible, we have used various modelling tools(Matlab, RNA Composer,mfold) to help us get the individual model of the aptamer and the protein. But we found it difficult to bind the models of the aptamer and the protein together. To solve this problem, we collaborated with the team ShenZhen_SMS to learn how to use the Discovery Studio to attach the protein and the aptamer together, we also provided a method for them to put their 3D models onto the wiki.
Mathematical Modeling
For the mathematical part of the modelling, Max.Chen, a member of Greatbay_SCIE last year has provided provided valuable ideas of modelling, for example, he has mentioned that the distance between the aptamer should be greater than the diameter of an HER-II molecule so that the aptamer would not block the HER-II from binding onto it. The idea is then further explored by our team by constructing the model of a liposome using the spherical coordinates and expressing the position of the aptamer using the coordinates, which allows us to analyse the optimum aptamer concentration in a mathematical way, his idea has provided a valuable direction of our models.
To see more information on our modelling, click here to go to the modelling page.
Others
Reference
Hongguang, S., Jingsan, Z., Jianbo, W., Youli, Z. & Zhu, X. (2016) Aptamer Technology and Its Application In Tumor Diagnosis and Therapy. Prog Pharm Sci Aug. 2016 Vol. 40 No. 8.