The process in which a drug candidate is discovered is known as drug discovery.
Drug discovery cycle involves different stages of efficacy testing before the initially identified compound can finally reach the status of clinical candidate that will allow it to be tested in clinical trials for its potential commercialization and use in patients.
Living cell recordings in drug discovery can help elucidate cell behavior under pharmacodynamic analyses, and reducing bias related to the experimental conditions. The 3D Cell Explorer is an easy way to test long-term living cells response to different conditions.
Drug development for the treatment of pulmonary arterial hypertension (PAH)
Selexipag (Uptravi®) is a recently marketed drug for the treatment of pulmonary arterial hypertension (PAH), released by Actelion Pharmaceuticals Ltd.
Pulmonary arterial hypertension (PAH) is a condition caused by obstruction in the small arteries in the lungs. Even if some risk factors such as drug abuse, scleroderma, and HIV infection are known to potentially lead to PAH, in most of the cases, its cause is unidentified.
As it is a chronic condition that tends to worsen over time, there is the need to provide effective drugs for its treatment. The efficacy of Selexipag (Uptravi®) as PAH treatment was proved in a freely available manuscript.
In the pharmacodynamic analyses performed, ACT 333679, the active metabolite in Selexipag (Uptravi®), induced cellular relaxation and inhibited cell proliferation and extracellular matrix synthesis. It also displayed partial agonism that allowed for full efficacy in PAH targets, together with a low desensitization rate. The ratio efficacy/desensitization of ACT-333679 compared to other commonly used anti-PAH drugs makes it a treatment of choice.
The 3D Cell Explorer was used to successfully monitor the drug induced cell shape changes in real-time.
Monitoring live and label-free effect of Khondrion’s drug KH176 with the 3D Cell Explorer
A major problem with current imaging techniques is phototoxicity that leads to the observation of perturbed dynamics. However, the 3D Cell Explorer overcomes this problematic as it injects in the sample ~100 times less energy (~0.2 nW/µm2) than light sheet microscopes (~1nW/µm2) that are the reference in the matter. With a resolution below 200 nm, it enables high resolution and high-frequency imaging even with sensitive material, giving access to organelle dynamics that were previously out of reach such as mitochondria and lipid droplets.
Khondrion’s drug KH176 rescues the cytotoxic effect by BSO
In collaboration with Khondrion, a leading clinical-stage pharmaceutical company focusing on small molecule therapeutics for mitochondrial diseases, we image here the effect of KH176, Khondrion’s leading drug candidate, in rescuing the cytotoxic effect induced by Buthionine sulfoximine (BSO). BSO inhibits the biosynthesis of glutathione, an endogenous molecule crucial for the maintenance of cellular redox states, progressively leading to cell death. KH176 counteracts BSO-induced cell death by targeting peroxiredoxin enzymes.
ADC Trigger Selective Cancer Cell Death
Chemotherapy has been used to treat cancer for almost 80 years now and its side effects are well known and documented.
One of the main limitations associated with standard chemotherapy is the unspecific killing of healthy cells (e.g. rapidly dividing cells in the bone marrow) which is associated with high-dose requirement and low therapeutic indices.
In order to significantly reduce systemic side effects, it is fundamental to develop a new generation of anticancer drugs, specifically targeting cancer cells and therefore better tolerated by patients. One approach relies on the use of monoclonal antibodies, the so-called “magic bullets” envisioned by Paul Ehrlich more than 100 years ago. Monoclonal antibodies (mAbs) belong to the broad class of biological drugs, or biologics (i.e. products derived from living organisms). MAbs have fueled research in many scientific fields with four dedicated Nobel prize winners in 2018 (https://www.nobelprize.org/nobel-prizes-2018/) and can be considered today a strong clinical reality with over 80 pharmaceuticals already on the market in indications not limited to oncology.
Antibody drug conjugates (ADCs) combine the target specificity of monoclonal antibodies with the cancer-killing ability of cytotoxic drugs, thus allowing for the discrimination between healthy and cancer cells and strongly reducing the side effect of conventional anticancer treatments –. Several elements of ADCs can be tailored to obtain the required anti-tumor effect such as the potency of the payload, the stability of the linker, the target antigen and the antibody affinity.
The Swiss Biotech company NBE Therapeutics, is an internationally recognized leader in the development of antibody-based therapeutics with a focus on next-generation Antibody Drug Conjugate (ADCs) products for the treatment of cancer. NBE therapeutics has kindly provided us with one of their anti-cancer ADCs and helped us in the set-up of a comparative qualitative experiment of efficacy on cancer cells. A mouse breast cancer cell line has been used and the appropriate unspecific isotype control included as reference.
The 3D Cell Explorer was used for long-time live cell imaging of the cell samples (up to approximately 60 hours of continuous imaging).
While the cells treated with the control ADC divided undisturbedly for almost 60 hours (Figure 1, left), treated cells were dead 34h 30 after treatment with the tumor-selective ADC (Figure 1, right). Moreover, increased endocytosis can be specifically observed prior to death in the presence of the tumor-selective ADC.
Endocytosis is a very dynamic process implying fine membrane modifications that are detectable with the 3D Cell Explorer like with no other microscope. To know more about endocytosis, check our post about it!
 D. R. Miller, “A tribute to Sidney Farber – the father of modern chemotherapy,” Br. J. Haematol., vol. 134, no. 1, pp. 20–26, Jul. 2006.
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 H. Kaplon and J. M. Reichert, “Antibodies to watch in 2019.,” MAbs, vol. 11, no. 2, pp. 219–238, 2019.
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Morphological profiling of cell organelles
HeLa cells treated with Vacuolin-1
Morphological profiling of cell organelles on live cells
With the 3D Cell Explorer you can extract quantitative data from 3D microscopy images or 4D time-lapses of live cells to identify biologically relevant similarities and differences among samples based on these profiles:
- Identify biologically relevant similarities and differences among samples
- Identify and measure morphological features (volume, shape, etc.)
- Detect your cell phenotype in one second and in 3D
Absolute Quantitation of live single cells
The Riken Institute from Japan analysed the precise volume of intra-cellular components and determined the exact concentration of drugs at a single cell or sub-cellular level by combination with mass spectrometry. The full publication can be found here: https://www.jstage.jst.go.jp/article/analsci/32/2/32_125/_pdf.