Promising research for genetic disorders by using gene editing

The Means Report

AUGUSTA, Ga. (WJBF) – Exciting research is underway at the Medical College of Georgia at Augusta University, especially when it comes to genetics. Promising results have already been discovered that could correct genetic problems and create disease models. It all starts with gene editing, in particular – prime editing. So what is prime editing? We take a closer look at the exciting research this week with Dr. Joseph Miano – a vascular biologist – and Dr. Lin Gan – a geneticist – both at MCG.

Brad Means: Dr. Miano, I know you’re so busy and you’re accomplishing so much over there, and we appreciate you being with us today.

Dr. Joseph Miano: Thank you, Brad. It’s a pleasure to be with you today.

Brad Means: All right, so let’s look at this prime editing when it comes to genetics, when it comes to DNA. As I understand it, you’re taking strips of DNA and you are snipping them. And so is it correct to picture something being snipped like a strip of paper and you’re holding scissors? Is that what it’s like at the molecular level?

Dr. Joseph Miano: It is, Brad. Prime editing actually, as you pointed out earlier, is the latest incarnation of this CRISPR craze, that’s taken a foothold in the world. And CRISPR, it should be pointed out, is a bacterial immune system. Much like we are susceptible to being infected, bacteria can be infected by viruses and they’ve evolved this CRISPR system to protect themselves. The CRISPR is basically a vaccination much like what we’re going through right now with the pandemic, to protect them from future infections. And so the CRISPR system first described by Jennifer Doudna in 2012, and she is one of the Nobel Laureates, of course. That system is, as you pointed out, a molecular scissors system to literally snip pieces of DNA at will and in a very precise way. And prime editing is a step above that because the CRISPR platform uses three components. Whereas the prime editing platform uses just two components. So it’s, in principle, easier to manipulate the DNA than the CRISPR system was just a near year and a half ago.

Brad Means: Would suspect the applications are endless. And the amount of DNA is endless. I mean, if you picture the human body, correct me if I’m wrong, you’re talking about DNA living in your cells. You have trillions of cells. Each DNA strand is about two meters long. And so it just seems like you could play around with it forever, couldn’t you?

Dr. Joseph Miano: Brad, I’m impressed with the amount of scientific knowledge you have. You’re absolutely correct about the length of DNA and it is endless. But we do know now since the genome has been sequenced and is now finished, just a month ago or so, they’ve completed to this single base, every single letter in our genome. And so there’s over 6,000 Mendelian traits that could potentially be targeted. In fact, sickle cell was one of the first. And in fact, the woman who got the first CRISPR therapy for her sickle cell just celebrated her first anniversary of the CRISPR therapy. And she is cured of her sickle cell disease. And there are a number of other genetic diseases that are underway. There’s over 50 clinical trials in this country alone using the CRISPR platform to zero in on these Mendelian traits. And really that holds a lot of hope for those people suffering from these traits, who otherwise don’t have much in the way of therapy. So it really is a revolutionary technology for the human condition.

Brad Means: Go back to those molecular scissors real quick. What does that look like? Are you looking through a microscope and doing these snips?

Dr. Joseph Miano: There’s some beautiful YouTube videos of animations, if you will, of how this works, how we think it works. It’s an enzyme, Brad, as the CRISPR-Cas system. And it is called CRISPR-Cas. Cas is the protein part of it. CRISPR, that would be the guiding part of it. And so the scissors of the Cas9 protein is an enzyme and it’s able to clip the DNA in a very specific way. And it does so through the CRISPR, which is a guide RNA. So, DNA is what makes life, but DNA is merely an instruction manual. That instruction has to get into the cell to make the proteins. And that instruction is passed through by the RNA. And so the RNA is what guides the molecular scissors to, for example, the site where sickle cell has a mutation to clip it and then repair it.

Brad Means: Does it grow back after you manipulate it? The strand.

Dr. Joseph Miano: Oh yeah. So that’s the beauty of it. So it’s a trick in nature. So what the molecular scissors does is not natural. It’s deliberately cutting the DNA, but then there are endogenous repair pathways. Our DNA is bombarded by a number of stimuli that cause natural breaks in the DNA, and so our cells have machinery to repair those breaks. And so what CRISPR does is it does cut the DNA at will wherever we would like it to cut it. But then we let the cells’ natural repair mechanisms fix that cut where the scissors cut to then fix the mutation. And the mutation is fixed by a what we call a template, a repair template that has the corrected base. And so we’re basically, swapping in the correct base for the mutated base that normally would be there.

Brad Means: Are you mainly working with mice? I know you mentioned the successful sickle cell results, but is it lab mice at this point, primarily?

Dr. Joseph Miano: Yeah. So Brad, we’re a basic science group in my lab and working with Lin Gan, who you’ll speak with in a moment. We are charged mainly with modeling human traits, diseases that we would like to correct in the mouse first. So we’re humanizing mice, if you will, with human DNA. And then we use the CRISPR or prime editing platform to fix the mutation in vivo with a hope that the mouse is then cured of that. And so we really are behind the curtain if you will, pushing forward the technology that eventually will make its way into the clinic so that physicians can use the CRISPR much like what physicians are doing at St. Jude and other hospitals curing sickle cell and other genetic diseases.

Brad Means: Is it too early to ask you how far off human trials would even be then? Years, decades?

Trials aren’t even going right now. Oh, you mean trials that we are working on in an animal model to try eventually to translate it into a human condition?

Brad Means: Absolutely.

Dr. Joseph Miano: That’s the question, sure. Years, Brad, years away. So we’re just starting now with modeling a very rare disorder of the digestive track, which people and in mice is lethal right after birth. And so we’re trying to fix that mutation that we know occurs in a very small segment of the world population in utero with a hope that the pups, in this case the mice, are born normally. If that’s the case, then we could move into larger mammals with the ultimate aim of devising a strategy to target the human. But it’s years away, Brad, to answer your question.

Brad Means: Well let’s just keep the crystal ball out though, Dr. Miano, and say that everything works perfectly. And we do see human trials conducted successfully in all sorts of illnesses and diseases and conditions. Would the best end result for all this be a shot or a pill, or is this something you would do before someone was born? When you went into the genes of that unborn baby and tried to make sure that they were born healthy? What’s the final result probably look like?

Dr. Joseph Miano: Well, the final result would obviously be the least invasive intervention. I believe we’re probably quite a ways away from that. Initially, it will be through direct injection, IV injection. So the most recent trial that was just published in New England Journal for a very rare disorder, that was an infusion where the patient received the CRISPR components or the prime editing platform, if you will, directly into their bloodstream. And the components make its way to the liver where the target gene is and the correction occurs in the liver. So I think initially it will be a bit crude, like infusion through direct injections to circulation or direct injection into the organ of interests such as the heart or into the liver, which is a very targetable organ. But I think ultimately it would be wonderful if it could just be a pill as you pointed out. And as you may know, there is an initiative that now is underway to make the COVID vaccine a vaccine that we could swallow, as opposed to going in and getting a jab into the arm.

Brad Means: Have you had any high five moments yet where you just thought, “Oh my goodness. I had no idea that we would come this far, this fast.” And it just made you more enthused than you already are about your work.

Dr. Joseph Miano: Wow. So, it seems every other month when I open up a journal article on the computer. The pace at which this technology is moving is lightning speed. And it’s a bit frightening because we still don’t know everything we need to know about things like, for example, of targeting events. So it’s not perfect all the time. It’s near perfect, but not totally perfect. And so it’s moving very fast. In fact, it’s blinding. In the beginning, back in 2013, when I jumped on the rocket ship, if you will, there were maybe five to 10 papers published every week. And now it’s hundreds, and it’s very hard to keep up with it. But in terms of a high five moment, we have high five moments very often just celebrating big leaps made in the field from other investigators like that very recent trial that came out of the New England Journal. But within the lab itself, we had some really big high fives when we discovered that a single base change literally shut off a gene. And that has a lot of implications for what we call single nucleotide polymorphisms, at which we have millions each. Each of us have these and most of them occur in these little snippets of DNA that turn genes on and off. And by showing, as we just did recently in a paper we just published in genome biology, that a single base change basically turns a gene off. That lends insight as to what may be happening with many snips or these single nucleotide polymorphism, as I mentioned, maybe doing in humans. And so that was the most recent high five moment. And I’m looking forward to the high five moment with the in utero gene therapy that people in the lab are working very hard on.

Brad Means: Well, I know that the more fascinating and rewarding developments are to come. Dr. Miano, thank you for all that you do, and best of luck with your continued research at MCG at AU.

Dr. Joseph Miano: Thank you very much, Brad.

Brad Means: Absolutely. Joe Miano over at MCG at Augusta University. When we come back, as he mentioned, his colleague, Dr. Lin Gan will be here to talk about his work, especially in the effort to build a gene editing core. As we continue to take a look at genetic research being done right here at home, on The Means Report.

Part 2

Brad Means: Welcome back to The Means Report, everybody. Continuing to learn so much on this edition as we take a look at the effort to treat diseases and correct genetic problems, research that’s being done every day at MCG. And we’re lucky to have a couple of experts on hand to help walk us through it. And we move on now to Dr. Lin Gan, geneticists at MCG at AU, hard at work in this gene research field. Dr. Gan, I appreciate you being with me. I said before we went to break that you were building a gene editing core, what is that?

Dr. Lin Gan: Basically, we build a facility so we can use gene editing technology apply into biomedical research. So we basically, build a facility to serve the researcher here. So we assist them with different CRISPR technology and build research models for them.

Brad Means: Listen, when potential med students hear about what you and Dr. Miano are doing over there, does it help with recruiting? I would think it would make more young people want to go to med school there.

Dr. Lin Gan: Of course. I realized, actually, CRISPR has been a lot of people’s mind, medical student and then graduate student. And then it was heard of coming, they get excited.

Brad Means: What’s a typical day like in the gene editing business? When you get to work each day, do you just get the microscope and the mice out and just start doing a lot of the stuff that Dr. Miano talked about in our first segment?

Dr. Lin Gan: Yes, actually. So we are actually involved with basically in the application part. How to fine tune this technology and use them to work in strategy and functioning, and then to modify research models. So, at a core facility, routinely basically, yeah, we do this microscope analysis or manipulation on databases.

Brad Means: Do you think that the findings that are happening every day in your lab, in your facility there at MCG, do you think that we can help cure diseases one day? Some of the big ones we hear about, some of the big diseases that seem uncurable. Cancer, to name one. Do you see a day in the future where those just go away or they’re easily treated?

Dr. Lin Gan: Yeah, like Dr. Miano said earlier. Actually it’s not in the future, it’s actually in the present right now. And then there are many clinical trials going on. And then, so basically you involve over several method. You talk about use CRISPR as a ex vivo method. So Dr. Miano talk about sickle cell disease. That’s basically taking the bone marrow out of the patient and they use CRISPR to collect mutation or to introduce therapeutical approach. And then we’ll put the cell back in the human to cure the disease. And then we also also talking about in vivo and Dr. Miano also mentioned that the recent publication talking about using… Actually, he literally disease. So that’s basically by IV infusion of CRISPR compounds. And then I worked in the eye. Actually, for this kind we were treatment. So basically, people can just inject these CRISPR into the eyeball. It may sound like a terrible but it’s actually not that bad. Actually, . So a couple of years ago, trials been going. And actually they try to correct human eye disease. So could –

Brad Means: Yeah.

Dr. Lin Gan: Disease, yeah.

Brad Means: Do y’all work with plants? I know we talked about the mice a lot. Do y’all try any of your gene editing on plants.

Dr. Lin Gan: We do not work in this on campus right now, but this is ongoing in agricultural field. We have a wonderful assistant who make a framework of and do other things. But we are not working on it ourself.

Brad Means: Listen, let me ask you this. When it comes to snipping and gene editing and doing things like that, are you changing someone’s genetic makeup? Or are you just taking out what you need and the person, if you will, remains the same?

Dr. Lin Gan: Right, actually that’s a wonderful question. So basically this approach allow you the ability to do both. And then currently, most are therapeutical way, they use for some medical mutations. So this doesn’t change, it correct gene in the body, but it doesn’t pass to second generation. In the lab we’re working on, because we do work in with embryo. So we talk about eggs. So through the animal models we do change the germline, in that sense. So it’s very powerful, very effective.

Brad Means: Do you ever get any pushback from people who are concerned that you are doing too much editing? That you’re changing the makeup of a person that was intended to be there? Anytime you talk about, and I know you know this, genetic research, some people get very uneasy.

Dr. Lin Gan: Right. So I would say again, because we do work in with the animal and then this animal is usually in the confined animal facility. So we do not work with human. But back in 2019, Chinese scientists that actually did the change of did make the CRISPR baby, which is a method. So this created a lot of controversy two years ago.

Brad Means: I know Dr. Miano mentioned how your efforts and the efforts in the genetic field can be used when it comes to vaccines. Do you see how some of the research that you’re doing each day at MCG might benefit us and it might help us if there’s another pandemic?

Dr. Lin Gan: Yes, actually, we were involved earlier last year when COVID-19 coming up, and there’s a lack of animal model for study disease. And then so we actually went in use CRISPR to create a different animal model for people on campus and have also other people to study this disease. So we’ll definitely use this, can accelerate the funding.

Brad Means: We talked about med students at the beginning of this interview and how are you teaching them what you’re doing? Is it a classroom setting at first, and then they move into the lab with you and Dr. Miano? Since a lot of this is so groundbreaking, it probably hasn’t made its way to a textbook yet. How do you teach it?

Dr. Lin Gan: Actually, it’s already in text book and then-

Brad Means: Okay.

Dr. Lin Gan: We teach it in class. But for us, we work in the lab. The lab is not really open to most student because most student doesn’t involve. We do have regular tools for the student. Basically get like a more inside looking of how this CRISPR work.

Brad Means: You know, MCG has led the way in so many ways. And Augusta University has when it comes to the response to this pandemic. I talked to Dr. Brooks Keel about that a couple of weeks ago on The Means Report. Are you all getting interest from other medical institutions, other research facilities around the country, maybe even the world. Who wanna say, “Hey, I love what y’all are doing there in Augusta, Georgia. Show us how to do it.”

Dr. Lin Gan: Yes, actually there are a lot of research institution doing these. And we also doing that. And then we, indeed actually, even as our facility, we actually serve people all over the country. So when they have a need for animal model, we do that.

Brad Means: Dr. Gan, what led you to get into this field? A field where maybe you can help people be healthier, where you can maybe one day make there be fewer birth defects. What led you to this field when you were young?

Dr. Lin Gan: I was always interesting. I was curious when I grew up and then when I get into school and then started biology. I was interested in how things, particularly like how organisms develop. So that interest has gotten me into the graduate school study, where we call it developmental biology. So basically study how a single fertilize embryos, the one cell, how to divide and they form different part of body. So this get me interested in and continue that way. And then because of my research interests that I realize that there’s a lot of need to understand the mechanism. So we’ve talked about the genes involved in this regulation. So I was into the gene regulation and that’s what get me into the mouse genetics. So we can use the genetical way to manipulate the gene in the embryo. And we’ll see the function of each gene and then how they regulate different part of the cell differentiation. And then to getting into CRISPR, I’ve been working with the mouse genetics for many years. And then in the past, most our genetics were using to manipulate gene, they use the technology called the gene targeting and only the stem cells. And the CRISPR coming out and it becomes such a powerful approach. And then, we quickly adopt it and then to make it more effective to study genes.

Brad Means: And you were talking about growing up and your interest in science and biology, those other kids in your science classes didn’t stand a chance, did they?

Dr. Lin Gan: Yeah. It is competitive field.

Brad Means: Yeah.

Dr. Lin Gan: Like the other field. Yes.

Brad Means: Well, we are so fortunate to have your expertise here. And I think that that speaks well to what kind of career, what kind of life you can have if you take an early interest in science. We have a lot of younger viewers and I think that they’ll take your words to heart, Dr. Gan. I sure do appreciate what you do and I wish you all the best with your continued research.

Dr. Lin Gan: Thank you, Brad.

Brad Means: Absolutely. Dr. Lin Gan at MCG at AU.

Copyright 2021 Nexstar Media Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

Trending Stories

Brad Means

The Means Report first aired in January of 2009 offering coverage that you cannot get from a daily newscast. Forget about quick soundbytes -- we deliver an in-depth perspective on the biggest stories. If they are making news on the local or national level, you will find them on the set of The Means Report. Hosted by WJBF NewsChannel 6 anchor, Brad Means, The Means Report covers the topics impacting your life, your town, your state, and your future.