Modern cancer therapy has definitely changed the way we are all understanding this condition, and the way we are treating it. Put simply, research is now aimed at understanding how tumor cells actually grow, as well as, more importantly, how to stop them from growing. Perhaps you want to learn more about it as well, either as a researcher, or as a person that is curious about this for any reason whatsoever.
Clearly, understanding how tumor cells grow is important because it allows for the development of many drugs that can target the actual machinery that allow for that growth and division. And, one of those targets is the Topoisomerase I, without which the cells cannot properly unwind and recoil their DNA, all of which can result in great damage during cell division. So, developing drugs that target it can have great implications for cancer treatment in general.
As mentioned, scientists are trying to discover drugs that target specifically those pathways that allow for cell growth and division. So, it is no wonder that they are also focused on developing drugs that target Topoisomerase I, and SN-38 Topoisomerase I inhibitor is one of them. And, it has become the cornerstone of cancer research and treatment, which is why it is not a surprise that you want to understand it better.
Now, you may not have heard of it directly, but you may have heard of the chemotherapy drug irinotecan, which is used to treat lung, colorectal, as well as other types of cancers. Well, SN-38 Topoisomerase I inhibitor is actually its active metabolite. There is no doubt that you have plenty of questions about it right know, and that you want to understand what it is and how it works, in which case you should keep on reading, to get the answers you are after and, thus, get a clearer picture on this particular drug.
The Role of Topoisomerase I
We definitely cannot start talking about this particular inhibitor if you don’t really understand Topoisomerase I specifically. After all, you have to know what it is that the drug is actually inhibiting, as well as why. So, let us make these things completely clear right now.
Basically, Topoisomerase I is pretty much like a molecular detangler of the DNA strands, which is an important process during replication or transcription. In few words, it makes a single strand break in one of the DNA strands, and we all know that DNA exists like a twisted double helix. By making this cut, Topoisomerase I allows the DNA to swivel and thus relieve the tension, after which it repairs the break and restores an intact DNA strand. Therefore, it allows for replication and thus, helps avoid cell death.
Now, clearly, this has an important role in healthy cells. But, when it comes to cancer cells, we know that DNA tends to replicate more often. That is why Topoisomerase I becomes a great drug target. After all, targeting and inhibiting its work can help slow down the replication process, thus eventually leading to the death of cancer cells, which is what most cancer therapies aim at doing.

What Is SN-38 Topoisomerase I inhibitor?
This brings us to the drug you are interested in learning about. So, what exactly is SN-38 Topoisomerase I inhibitor? That is your main question here. Although, if you’ve been reading carefully, I suspect that you have already understood this to a certain extend. Nevertheless, let us make things completely clear, so that there is no doubt left that you understand this drug completely.
So, SN-38 Topoisomerase I inhibitor is actually a drug that acts as a, well, Topoisomerase I inhibitor, as it is perfectly logical. This means that it stops its work, preventing it from sealing the cut that it has made in the DNA strands, and thus slowing down replication and leading to cancer cell death. I suppose it is clear how important of a role this is.
Now, what you need to know as well is that this drug is not given directly to most patients. Instead, it is actually produced inside the body when people get the drug irinotecan, and when it is metabolized by liver enzymes. In short, it is this particular transformation process that turns irinotecan into its more potent form, which is the SN-38 Topoisomerase I inhibitor.
Since it isn’t given to patients, you may be wondering why it is so important at all. Well, the truth is that scientists are studying to better understand how it works, and what it can do in terms of killing tumor cells, and basically treating cancer. Studying this potent form is significant, because it allows researchers to get a clearer picture of what happens in the body when they are given irinotecan, which pretty much acts like a vessel for SN-38 Topoisomerase I inhibitor, which actually kills the cancer cells. So, researching it is, without a doubt, of crucial significance.
How Does It Work?
Topoisomerase I makes the cut in the DNA, and that’s where SN-38 Topoisomerase I inhibitor comes in. It binds to the junction and prevents Topo-I from resealing the actual cut. This creates permanent damage into the DNA, resulting in double strand breaks, which cannot be that easily repaired. All of that, as you may have guessed it, results in cell death.
What Cancers Can It Help Treat?
Another thing you want to know here is what kinds of cancers this drug can actually help treat. And, well, through irinotecan, and perhaps some other SN-38 based therapies, SN-38 Topoisomerase I inhibitor has become a vital part of the treatment processes for various different cancer types. Those include colorectal cancer, lung cancer, pancreatic, ovarian, gastric, triple-negative breast cancer, as well as some others. And, of course, scientists are continuing to innovate around this drug, leading to improving targeting and understanding how to personalize the dosing and the treatment processes in general. On top of it all, SN-38 Topoisomerase I inhibitor is also used in combination with other therapies, to enhance the process of killing cancer cells.












