Is it nature or nurture that determines our fate? Is it our genes that make us who we are or our environment? According to some of the speakers at this symposium, we are not fully responsible for many of our behaviours. Our bodies and minds are affected by genes, hormones and bugs. Nature is what makes us.
Molecular Biodiscovery is what the Maurice Wilkins Centre is all about. It’s a research centre looking at cancer research, diabetes and molecular disease, infectious disease and integrative technologies.
Diana and I were invited to this symposium at the Old Government House as CEOs of a charity! The event was on 21 November and was meant to feature Dr Lance O’Sullivan and someone talking about targeted therapy but they could not attend so two visiting professors from Otago University offered their time instead.
Only one of the following stories relates to head and neck cancer but they are to do with health and the often thankless work carried out by underfunded research institutes across the country. We need to support them.
The venerable old house, by the way, was built in about 1856, has a resident gray cat called Governor Gray and a pleasant old fashioned rose garden.
I’ve written a brief summary here. Each speaker had a favourite type of organism/hormone/cell etc so I’ve taken the liberty of concentrating on those:
- leptin (keeps us slim)
- prolactin (helps us feed and care for kids)
- the gut microbiome (good bugs and bad)
- T-cells - can be engineered to kill cancer
I don’t have a science background so I may have made some errors. Feel free to comment.
Leptin: Professor Tony Merriman, Otago
Professor Tony Merriman is a genetics expert from Otago University. Our genes don’t simply give us obvious things like our height but also contribute to our weight and our propensity to get diseases like gout and diabetes. Instead of blame, we need to look at a more biomedical approach to disease, he says.
Obesity, he says is genetic. It’s biologically driven, not a “choice” thing.
He showed us a story about a obese baby with a rare genetic mutation, probably a leptin mutation.
Leptin is “the hormone of energy expenditure”, made by adipose cells that helps to regulate energy balance by inhibiting hunger. (Wikipedia)
They have done experiments with mice. If a mouse has a leptin mutation, it never knows when it’s full. When given leptin injections its condition is fixed.
Leptin resistance is similar to insulin resistance with diabetes.
You can look up your genetic disposition using this website but so far it is not a very robust test and is mostly valuable for ancestry etc. (He gave a test to his wife for her birthday. She wasn’t best pleased.)
https://www.23andme.com/ (We 23 pairs of chromosomes)
There is so much new research into genes that Wikipedia is way behind.
Similarly, conditions like gout which are often blamed on behaviour, are greatly increased by a genetic factor. The ABCC2 genre is quite common in Maori and Pacific Island males and predisposes them to gout.
As for diabetic treatment, we are still in the dark ages. We can prevent type 2 diabetes with bariatric surgery which at only $9000 is cheap and safe. But we do very few. (I think Professor Shepherd who ran the symposium made this comment.)
Prolactin: Professor Dave Grattan, Otago
Our body weight is usually automatically maintained although it goes up bit by bit as we age. Our fat tissues (leptin) tell us what energy we have stored and our brain adjusts to compensate. A stable state is called homeostasis.
But when we are pregnant that balance is upset because a hormone called prolactin makes animals like us smash the leptin receptors.
We monitor our weight differently during pregnancy. Weddell seals’ milk is 60% fat so they have to put on a lot of weight during pregnancy. Lactation will require energy so pregnancy hormones override the homeostatic feedback.
In conclusion, our body weight is somewhat affected by hormones in the body, not just by what we desire to eat.
(Prolactin could also be called the parenting hormone. Fathers might have high levels of prolactin. The wider whanau of baby monkeys will have high prolactin!)
The microbiome of the gut: Dr Xochitl Morgan , Otago
This is a fascinating topic, only some of which I understand. The microbiome consists of bacteria, viruses and other single celled organisms = bugs
- We have 10 trillion bacteria in our bodies
- We have 7.5 million genes in our bugs
- 1 human genome has only about 20,000 genes
Bacteria can do more than us. They can modify drugs, affect the brain and metabolism.
When we digest fibre we have only 9 enzymes to break it up so the gut microbiome are much better at this,
Some bugs protect us from disease but it you kill all the bugs with broad spectrum antibiotics, you kill the good bugs too.
An example of microbiome treatment is using faecal implants to cure C-Diff. (clostridium difficile). That means replacing the good bugs. Restoring function.
Here is an explanation from WebMD
“You take antibiotics to knock out a bacterial infection. But for some people, these drugs can trigger a potentially life-threatening infection caused by a type of bacteria called clostridium difficile, or C. diff. It can cause colitis, a serious inflammation of the colon.”
Probiotics and prebiotics as they are marketed are not the results of an exact science. You don’t need these if you are healthy.
But you do need a proper balance of microbiomes to make your immune system work. Antibiotics can tap the reserve.
T-cells: Professor Rod Dunbar, Auckland University
Rod talked to us about immunotherapy. We probably already know that Pharmac has approved Keytruda and Opdivo, two immunotherapy drugs which can cure some melanoma patients and are showing some promise with head and neck cancer overseas.
Immunotherapy is the hope for the future because it can help our own immune system recognise and combat the cancer. He showed as a video of little wriggly T-cells (the rock stars of the immune system?) going in to take on cancer cells and exploding them. Trouble is, nature has not provided T-cells with the weaponry to tackle cancer cells so researchers have to find ways to weaponise T-cells.
There is also a method called CAR -T which the Maurice Wilkins Centre is taking to trial at the Malaghan Institute in Wellington.
What is CAR-T?
Chimeric antigen receptor. Chimeric antigen receptors (CARs, also known as chimeric immunoreceptors, chimeric T cell receptors, artificial T cell receptors or CAR-T) are engineered receptors which graft an arbitrary specificity onto an immune effector cell (T cell).
A CAR-T empowered cell can only see the outside of cancer cells so will be limited in use but effective for some. Not many cancer cells have targets on the outside.
This was a very interesting talk and quite easy to understand but I have to confess I can’t understand my notes so this is only a brief summary. Fortunately we managed to track Rod down after the lecture to invite him to speak to our Auckland group next year.
It was an interesting series of lectures. At one stage an audience member argued for a sugar tax which she said had worked in Mexico. No, said Professor Shepherd. It won’t work. Certain sectors of society will still drink soft drinks and still smoke despite the expense and that just harms their children. Addiction is in the genes and needs to be treated accordingly. When prices go up rich white people change their behaviour but it doesn’t work for all.
Hmmm. Can’t we have both? A sugar tax and a biomedical approach?
And finally an old-fashioned rose from the Govt House garden. Maybe it needs some genetic engineering?