Kathrin Böpple, PhD, Scientific Project Manager, Dr Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany; and Meng Dong, PhD, Principal Investigator; discuss the cultivation of primary mantle cell lymphoma (MCL) cells in 3D and how it enables in vitro long-term experiments.

Transcript:

Dr Böpple: Hello everyone. My name is Kathrin Böpple and I'm scientific project manager at Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology at Robert-Bosch-Hospital in Stuttgart, Germany.

Thanks a lot for inviting us to present our data here. The work we are talking about today was done during my PhD in the group of professor Aulitzky, that is dealing with preclinical models and tumor sensitivity.

Dr Dong: Hello everyone. My name is Meng Dong. I'm a principal investigator in the same research group of professor Aulitzky at the same institute as Dr. Böpple. I supervised this work during Kathrin's PhD study.

Dr Böpple: MCL is an aggressive B-cell lymphoma with generally poor outcome. Treatment of MCL remains challenging in parts because of the limited cultivation time of primary MCL cells.

In recent years, our group has worked with several MCL studies, often finding that the primary cells from patients show apoptotic behavior after 24 hours in suspension culture. This is also described in literature as mentioned in our abstract from the AACR Annual Meeting.

Back then the interest in our group was, and still is today, very high to find better cultivation systems to optimize the culture of primary MCL cells for a longer time.

Together with our colleagues from the pathology department, we aim to improve the cell survival time required for in vitro tests by means of 3D cultivation.

Oncology Learning Network: Could you briefly describe the study and its findings?

Dr Böpple: We established a 3D hydrogel culture model to cultivate primary MCL cells. We started to test the 3D hydrogel culture model with cell lines for its feasibility and stability. After 3 days of culture, we could successfully analyze the cells cultured in the hydrogel. For cell viability we used a confocal laser scanning microscope-based assay to stain live and dead cells, and conducted flow cytometric analysis.

Also, we checked the cell metabolism by analyzing pH and measuring glucose and lactate concentrations.

Furthermore, we investigated biomarker expression by using immunohistochemistry.

In the next step, we cultured primary MCL cells in the 3D hydrogel system. After 2 days of culture, the MCL cells in normalsuspension showed an almost threefold higher percentage of apoptotic cells than the cells cultured in the 3D hydrogel system.

Even after 3 days of cultivation, we still saw about 2.5 times more apoptotic cells in the suspension culture compared to the 3D culture.

Therefore, we conclude that our 3D hydrogel culture system is a more suitable cultivation method for primary MCL than the commonly used suspension culture in normal cell culture medium.

OLN: Were any of the outcomes particularly surprising?

Dr Dong: Using this 3D culture model to culture primary MCL cells from patients, we observed an almost twofold increase in cell culture period, and it was beneficial for cell survival after 4 days of culture.

Compared to the normal suspension culture where cells are freely floating in the medium, the 3D hydrogel can increase the cell viability and prolong this culture period.

It is most surprising to us that this 3D hydrogel support is so important for the primary MCL cells, although the cells are not adherent cells in normal 2D culture system.

Normally, we culture them as suspension culture.

Another point is that we also tested different oxygen concentrations for culturing the cells, and found out that there is no difference if we use 1.5% oxygen or 20% oxygen in the culture. It looks like that oxygen concentration does not have much influence in this 3D culture system.

OLN: What are the possible real-world applications of these findings in clinical practice?

Dr Dong: In clinical practice, this 3D culture model can be used to directly culture the patient cells from biopsies or from the tumor after the surgery. Drug screening can be applied for rapid therapy evaluation to predict the patient response for personalized medicine.

On the other hand for the drug development, one could actually enhance the drug selection for clinical trials and also use it as a pre-clinical model for testing novel therapeutic innovations such as the very hot topic CAR T-cell therapeutics.

OLN: Do you and your co-investigators intend to expand upon this research? If so, what will be your next steps?

Dr Dong: The next step will be mainly divided in 2 parts. The first part is to further optimize this 3D culture system as a more complicated system. We can culture different type of primary cells in this system for longer period as a co-culture system. We can mimic the tumor microenvironment.

The second part is to run experiments with more patient materials to validate this 3D culture model and perform drug treatment to evaluate the drug response in this model system.

Furthermore, we also plan to investigate other tumor entities with this model and try to have more possibility to bring them also into preclinical models.

OLN: Is there anything else pertaining to your research and findings that you would like to add?

Dr Dong: We all know nowadays it's quite normal that the tumor microenvironment play a very important role for the drug resistance, also for efficiency for the drug therapy.

It is actually important that a preclinical model captures the complex tumor biology in vitro in order to individually predict the in vivo therapy of tumors. Except this 3D hydrogel system. Actually, this system we established is for non-solid tumors. It's for MCL. We also cut the lymph nodes from the patients as precision-cut tumor slices.

With precisely defined thickness from 200 to 400 micrometer. So, the slices can also be further cultured ex vivo for more than 3 days or up to 1 week. The slices can maintain both the 3D architecture and also tumor heterogeneity of the original tumor.

It can preserve tumor microenvironment concerning different cell types and also the extracellular matrix. So, the drug treatment can also be applied to this system.

To combine a 3D hydrogel model and the tissue slices model together, we actually can establish a platform which can be used for both non-solid and also solid tumor for drug development and also for personalized medicine.

Source:

Böpple K, Staiger AM, Horn H, et al. A step closer to in-depth analyses: Cultivation of primary mantle cell lymphoma cells in 3D enables in vitro long-term experiments. Abstract presented at: AACR Annual Meeting; April 8-13, 2022; New Orleans, LA. Abstract 199/25.