4 ms·

In vitro studies have been done for ages, but are often a worse model than closely related organisms. For instance, there are various human cancer cell lines an

by klmr 8y ago

In vitro studies have been done for ages, but are often a worse model than closely related organisms. For instance, there are various human cancer cell lines and while these are routinely used to study various aspects of biology (cancer being just one of them), they are generally a poor model for drug trials. The current research trend goes towards developing organoids — cell cultures with a distinct 3D organisation and biological makeup that mimics actual organs — that more closely resemble actual human tissues. It’s still early days though.

bayesian_horse 8y ago
Organoids do count as in vitro. And as I said, synthetic biology, automation and machine learning help in improving these methods. Nothing can replace certain studies in Humans completely. We can only hope to make those more effective by better choice of candidate drugs.
- klmr 8y ago
  Absolutely. My phrasing wasn’t clear, I was contrasting organoids with the cell cultures mentioned in your reply, not with in vitro studies in general.
  - Amygaz 8y ago
    Organoids, organ-on-chip, 3D cell cultures, have all shown to be equivalent to each other, and better than standard 2D cell culture. Ultimately they are not very complex, definitely more than a monoculture, but no where near an organism that evolved from a single cell. They haven’t shown to be a good proxy for a whole organism. On term of disease model, they are typically artificial in the sense that genetically engineer the cell with a specific mutation that may or may not represent the disease or the population. And if an experiment doesn’t work the way you want, you are a new set and sometimes it works the way you want. The only two things they have over mice is that they can be from human origin, and sometimes that human origin might be in a disease state that you want to study, which might be the only way to generate a model for complex disease...
    - bayesian_horse 8y ago
      In-vitro and In-silico modelling might be of great use is for known problems that come up for candidate drugs in the early clinical phase: Interaction with receptors (blood/brain barrier, QT prolongation etc) or liver proteins or the like. Of course, we are talking about the fruits on the drug tree which are potentially reachable by singular small molecule drugs.

by klmr 8y ago

bayesian_horse 8y ago

Organoids do count as in vitro. And as I said, synthetic biology, automation and machine learning help in improving these methods. Nothing can replace certain studies in Humans completely. We can only hope to make those more effective by better choice of candidate drugs.

klmr 8y ago
Absolutely. My phrasing wasn’t clear, I was contrasting organoids with the cell cultures mentioned in your reply, not with in vitro studies in general.
- Amygaz 8y ago
  Organoids, organ-on-chip, 3D cell cultures, have all shown to be equivalent to each other, and better than standard 2D cell culture. Ultimately they are not very complex, definitely more than a monoculture, but no where near an organism that evolved from a single cell. They haven’t shown to be a good proxy for a whole organism. On term of disease model, they are typically artificial in the sense that genetically engineer the cell with a specific mutation that may or may not represent the disease or the population. And if an experiment doesn’t work the way you want, you are a new set and sometimes it works the way you want. The only two things they have over mice is that they can be from human origin, and sometimes that human origin might be in a disease state that you want to study, which might be the only way to generate a model for complex disease...
  - bayesian_horse 8y ago
    In-vitro and In-silico modelling might be of great use is for known problems that come up for candidate drugs in the early clinical phase: Interaction with receptors (blood/brain barrier, QT prolongation etc) or liver proteins or the like. Of course, we are talking about the fruits on the drug tree which are potentially reachable by singular small molecule drugs.