Main Question: How does Gene Therapy affect cancer cells?

Sub Question: Which out of the two, Somatic or Germline, is the most effective on specifically cancer.

Hypothesis for Main Question:

Gene therapy and its different procedures in general, should help slow down or cause cell death to the cancer cells, because the procedure introduces new genes that are modified to isolate and eventually kill mutated cells. 
 

Hypothesis for Sub Question:

We think that Somatic Gene Therapy is more effective because the result, whatever it may be (good or bad) is controlled and only affects the patient to which the procedure has been performed on. So, side effects won’t impact the future generations unlike Germline Gene Therapy, where the genes are inserted into cells that reproduce and therefore affect the patients' descendants. 

 

 

Gene Therapy:

Gene Therapy is a method of the up-and-coming treatment; Genetic Engineering. The main objective is to treat or cure diseases. There are several mechanisms to do so, like:

 

•  Replacing a disease-causing gene with a healthy copy of a gene
•  Inactivate a disease-causing gene that is malfunctioning 
•  Introducing a new or modified gene into the body to help treat the disease

There are two procedures to achieve the objective although they are slightly different;

 

• Somatic Gene therapy – where the mechanisms will be done to a part of the body that does not play a role in reproduction and will not affect the future generations. 
• Germline Gene therapy – Similar to the first one, only alteration is that the mechanisms will be done to a part of the body that does affect reproduction (Producing either sperm or eggs) and therefore may affect the future generations.

Germline Gene Therapy:

• Germline Gene Therapy uses the involvement of a lot of gametes like sperm and/or egg cells. 

 

• Through this treatment specific genes are modified or removed usually for the purpose of treating or eliminating diseases. 

 

• Germline Gene Therapy can occur in vivo ( through injecting the modified genes or through vitro when the reproductive cells are removed from the patient and brought to the lab to undergo the procedure and then returned to the body. 

 

• But due to the process being done on reproductive cells, the aim is to pass these modifications on to the next generation.
•  

Unfortunately, there hasn’t been any trials of germline gene therapy 

specifically on cancer, that has been done on human cells.

 

• There have been trials for this procedure that have been conducted on animals, but is not yet considered safe to be implemented on humans. 

 

• Tests that have been done on animals have shown effectiveness rates of 80% and 90% but they can also be as low as 20-30%, it is mostly dependent on the animal and the experimental design. (FOR CANCER)

 

Somatic Gene Therapy:

• Somatic Gene Therapy focuses more on correcting the specific defects in our system or enhancing our natural defenses against cancer for a more successful outcome in our long battle. 

 

• Take into consideration that the reaction, whatever it may be, will only affect the patient and not their descendants, as it is being done on somatic cells (cells that do not produce sperm or eggs). 

 

• But the rest of the procedure is quite similar to the germline gene therapy. 

 

• Somatic Gene Therapy has shown great promise and growth in treating cancer. 

 

• But the effectiveness rate clearly depends on many factors, such as the type of cancer, the specific gene itself and the delivery method ( whether it was vivo or vitro). Certain somatic gene therapies have shown incredible amounts of tumor regression in particular types of cancer cells. 

 

• The effectiveness however ranges from 30% to 70% in clinical trials and is solely based on the patient and the type of cancer. 

 

• So far there haven’t been any side effects or long term reactions to the procedure and a positive benefit is that the result only affects the patient. 

Somatic Pros:

• The effect of procedure only affects patient and therefore won’t impact their future generations
• You have a choice in the delivery method ( Vivo or Vitro )
• Shown significant amounts of tumor regression. 
• No side effects or long term reactions so far.

 

Somatic Cons:

• The effectiveness rate is dependent on the type of cancer and how the patient’s body responds to it. 
• Wide range of success meaning the effectiveness is not stable.
• Still being experimented and not yet fully confirmed of positive impact. 

 

Germline Pros:

• Modifications can be passed on to the next generation, so they don’t have to go through the process themselves.
• Point of the procedure is to eliminate disease entirely from the patient's DNA.
• Trials done on animals have shown positive results for cancer elimination specifically.

 

Germline Cons:

• No established effectiveness rates of tests held on humans.
• Many Ethical concerns of procedure because the result whether good or bad will affect their descendants.
• Not in active use for Human cancer treatment and is still dangerously experimental.

 

Explanation of Graph:

Finding the data for this graph was one of the hardest parts of  the project. We want to make it clear that for each year, the percentage is the mean or average of the studies and trials done on 4 different types of cancer, treated by somatic gene therapy. Those 4 types of cancer were; Acute Lymphoblastic Leukemia (ALL), Chronic Lymphocytic Leukemia (CLL), Multiple Myeloma and Melanoma.

Disclaimer: 

We realized the percentages are the success rates or response rate. It is not clarified what percentage of the patients relapsed. But from other related studies we can expect the complete remission rate to be more than 50% of the actual percent. 

 

Answer to Sub-Question:

• There is no question, Somatic Gene Therapy is definitely the better option. 

 

• Germline gene therapy, although having some positive results, has not been performed on human cancer cells, so it cannot be declared effective until done so. 

 

• We were not aware of this fact when we finalized our sub-question. 

 

• But we decided to leave the question because theoretically both procedures do have potential and can be a successful treatment method if they were thoroughly experimented and improved upon. 

 

• They both cause ethical concerns, germline significantly more than the other, due to the results being more permanent. 

 

• Somatic Gene Therapy still doesn’t have completely stable results but there were more than a 100 trials and more actual procedures done on suffering cancer patients and based on the graph; Somatic Gene Therapy is definitely on the table to efficiently treat cancer

 

Answer to Main Question:

Gene Therapy affects cancer cells through many ways, such as; replacing or inactivating mutated cells, introducing a new gene to treat the disease-causing genes, etc. There are many ways to achieve this, but they are divided into two main categories; germline and somatic. 

 

• Germline gene therapies use reproductive cells in their process and Somatic gene therapy uses Somatic Cells (cells that do not produce sperm or eggs). Somatic gene therapy is the procedure actively being used out of the two. 
• Germline gene therapy has only been tested on animal cancer cells, due to the ethical reasons of the procedure. The results of germline will be passed on to the next generation, there is no concern in that if the result is positive, but if it isn’t it will affect more than one person. 
• There have been no established effectiveness rates for germline gene therapy, since it is a recent procedure and very much in the early stages of trials and experiments and the research is mostly based on theory. 
• But Somatic gene therapy on the other hand has been around for the past ten years, and during that time period the therapy has grown and flourished to help many around the world (well at least some places in the world, as gene therapy is banned in certain countries). 
• However the effectiveness is purely based on the patient, the specific genes and the type of cancer. The average of success rates in 2023 across 4 different types of cancer was 91%. 
• Somatic gene therapy shows good promise and is definitely affecting the world through its effect on cancer cells. 
• Gene Therapy has performed just like how we thought it would in our hypothesis, in fact its results have amused us and in the future with more experiments and trials we should be able to offer a 99% success rate and hopefully have found the cure to cancer! 

• Gene Therapy for Cancer Treatment: Past, Present and Future - PMC. 

 

• In Vivo vs. In Vitro: What Are the Differences?. 

 

• Germline Gene Therapy | Definition, Types & Ethics | Study.com

 

• Revolutionizing Cancer Treatment: A Glimpse into Gene Therapy  

 

• ScienceDirect Germline Gene Therapy
• Gene therapy: advances, challenges and perspectives - PMC 

 

• Gene therapy clinical trials, where do we go? An overview - ScienceDirect 

 

• Gene Therapy 2017: Progress and Future Directions - PMC

 

• Gene Therapy: International Regulatory and Health Technology Assessment (HTA) Activities and Reimbursement Status | CDA-AMC

 

• Looking ahead: ethical and social challenges of somatic gene therapy for sickle cell disease in Africa   

 

• A guide for patients and caregivers | Alliance for Cancer Gene Therapy 

 

We used some information from our last Science fair project that was about Genetic engineering!

These are some but not all of our sources used. 

All pictures and diagrams were taken from google.

 

We would like to acknowledge the support and help Mr. Worthington (science teacher), Ms. Moncks (student teacher) and especially Mr. Rip (science fair coordinator) gave us throughout these last couple months. A special thanks to you all for encouraging us! We are most grateful to our parents for taking us to and from meetings and giving us constructive feedback for our project.