lecture 14: stem cells: what is all the fuss? Flashcards
1
Q
What do people hear about stem cells?
A
- concern about use of human embryos
- very catchy, emotive captions
- “you, me, everybody”
2
Q
How acceptable do the australian public think using stem cells to conduct medical research and treat disease is?
A
- don’t know - 6%
- no - 5%
- yes - 88%
- DIISR - community attitudes to biotechnology (2010)
3
Q
Does the australian public think of using human embryonic stem cells to conduct medical research and treat disease is acceptable?
A
- don’t know - 6%
- no - 17%
- yes - 70%
- DIISR - community attitudes to biotechnology (2010)
4
Q
What are issues associated with use of human embryonic stem cells in research?
A
- isolate cells from inner cell mass of blastocyst
- day 6
- this is how you get the stem cells
- the embryo is destroyed in the derivation process
- this is what is so offensive to that minority of the population
- preimplantation embryos are vastly different from foetal tissue
- originally created for infertility treatment that are no longer required
- very very small
- however a human embryo is probably different from simply a culture of cells
- has a potential to be a life
- only can be realised if put in a uterus, and even then only 30% of those will go on to full pregnancy etc
- concern about the sanctity of life and reproductive technology
- isn’t an embryo a life?
- why do scientists have to kill IVF embryos to get stem cells?
- why do we have excess IVF embryos? why do IVF clinics deliverately make more embryos than are required? do they do this to make more $?
- are IVF couples forced to donate their embryos? if they don’t will their treatment be compromised?
- concern that IVF embryos are “farmed” for spare parts
5
Q
What are issues associated with use of human embryonic stem cells in research (SCNT) ?
A
- great concern about the abuse of this technology
- rate limiting factor could be considered to be where are the eggs going to come from
- scientists use SCNT to create life to destroy a life (embryo = life)
- can’t SCNT be used to clone humans?
- concerned that women will be exploited by SCNT - forced/able to sell eggs
- SCNT will be used to create monsters (half human/half animal) if animal eggs are used
6
Q
Are iPS cells really the ‘ethical’ alternative?
A
- Yamanaka
- by passes use of human embryo
- not without its ethical issues
- Yamanak told Nature: “we are presenting new ethical issues, maybe worse ones, because many people can do this – and without telling anybody”
- establishment of induced pluripotent stem cells from centenarians for neurodegenerative disease research
- iPS can also be used to create clones e.g. Tiny the mouse
- very inefficient generation
- tetraploid blastocyst generated by fusion of two-cell embryo
- iPS cells are injected into the tetraploid blastocyst which then steer development
- developing embryo is implanted in surrogate mother
- 22 births/624 injections (3.5%)
- 2 births/187 injections (1.1%)
- nature paper demonstrated germline transmission
- very inefficient generation
7
Q
How is the use of stem cells highly regulated?
A
- project by project consideration of:
- how consent will be obtained
- likelihood of significant advance in knowledge or improvement in technologies for infertility treatment
- number of embryos necessary to achieve project goals
- ethics approval and NHMRC licence; research involving use of human embryos act 2002, prohibition of human cloning act 2002
- embryo
- stem cells
- research
- national statement on ethical conduct in human research
- SCNT for stem cells allowed following 2006 amendment
- prohibit the transfer of an embryo generated by SCNT to the uterus of a woman or animal
- iPS cells:
- need national statement on ethical conduct in human research
- ethics approval to get tissue sample
- OGTR (office of gene transfer technology ) if the genetic modification is required
- stringency isn’t quite as great for the generation of iPS cells
8
Q
What is the perception of stem cells in the media?
A
- they’ve had a lot more success than actually true
- “grow new breasts”
- stem cell cancer cure hope
- dental and medical news: stem cells grow replacement
- stem cell method offers new hope
- breakthrough in diabetes research
- grow your own heart
- no men or women needed: scientsits create sperm and eggs froms tem cells
- artificial sperm takes men out of equation
- stem cells turned into glow-in-the-dark blood cells
- stem-cell-coated contact lenses are curing the blind
- alzheimer’s hope
- lipo fat turns to stem cells
- stem cell crystal ball
- grow your own organs
- only proven use of stem cells is using HSCs for blood diseases
- not for broad application
- long way from being able to deliver on the promise of stem cells in regenerative medicine
9
Q
What is the growth in ‘novel’ applications of stem cells?
A
- huge community demand
- gradual increase in the number of clinical trials
- not meeting demand
10
Q
What are clinical trials to evaluate possible treatments?
A
- mesoblast (ASX) bone marrow → cartilage, bone, heart
- advanced cell technology
- precursors from embryonic stem cell → rare type of blindness – stargardt’s macular degeneration and macular degeneration
11
Q
How can stem cell science be translated?
A
- demonstrated efficacy and risk assessment in preclinical models
- peer review
- clinical trials
- proven therapy
- !
- rationale and preclinical evidence of efficacy and safety
- peer review
- medical innovation, involving few seriously ill patients
- clinical trials when possible
- proven therapy
- !
- no rationale or preclinical evidence of efficacy
- no peer review
- stop
- X
- we are now seeing lots of illegitimate companies advertising use of stem cells
12
Q
What are hazards of unproven stem cell treatments?
A
- outside clinical trials by non-experts
- lack of proven benefits
- endorsed by patient testimony
- risk of physical harm
- financial exploitation
- diversion from existing proven therapies
- disqualification from future clinical trials
- based on selling hope
13
Q
What are experiences of Australians in regards to medical tourism?
A
- findings:
- considered pro-active and well informed
- did not seek advice from local doctor
- no choice but to travel abroad
- australia ‘fallen behind’
- condition deteriorating quickly
- aware possible risks and benefits
- risks defined as financial
- high costs
- financial and emotional
- all reported benefits – ‘it works’
- considered pro-active and well informed
- “it can down to the worst that could happen was nothing really…. we could spend our money have gotten no result…” - lisa
- “i have not regretted it for a day. it certainly made a difference and as I said, it’s given me hope…” - natalie
14
Q
At what cost (medical tourism)?
A
- more at risk than “doing your money”
- unexpected growths
- scientific american: in the flesh: the embedded dangers of untested stem cell cosmetics
- new scientist: stem cell treatment causes nasal growth in woman’s back
- stem cell ‘cure’ boy gets tumour
- death
- forestdale man died after operation to help him walk again
- europe’s largest stem cell clinic shut down after death of baby
- both died from the incredibly invasive techniques used to deliver the stem cells
15
Q
What unproven SCTs are being offered in Australia?
A
- increasing number of doctors offering autologous “stem cell” or SVF treatment
- usually liposuction derived but also peripheral blood
- $9k+ per treatment (multiple encouraged)
- offered for many conditions including osteoarthritis, autism, retinal neuropathy, MS, MND, and SCI
- intra-articular and IV delivery
- marketed as ‘medical practice’
- if there is a catastrophe the whole industry will get shut down
16
Q
How are stem cells a regulatory challenge?
A
- only regulated if donor cells used
- if using patient’s own cells doctor can do almost whatever they want
17
Q
What is the expectations gap?
A
- most support, lowest perceived risk
- demand from patients is not going to go away
- si per Stamina, si alla vita
- we are here for the freedom of cure with stem cells because in italy our politicians want to destroy our hopes
- stamina was a clinic offering help to sick and dying children that otherwise were not getting much help
- brought to the attention of the government and shut down
- these people were outraged
- right to try
- minimal standards
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