Characterization of bioactive substances MHGF-68 on tumour cell lines with LiveFlow In Vitro Technology

As part of experimental research, growth factor-like substances associated with MHV-68, named MHGF-68, were discovered in our laboratory. MHGF-68 activity was manifested by the ability to alter cell morphology, that is, normal phenotype to transformed, resp. suppresses the transformed phenotype of tumour cells. The aim of the experiments was to monitor the effect of MHGF-68 on the change of the cell actin cytoskeleton in the tumour cell line Hepa1c1c7, as well as the normal cell line NIH3T3, and compare conventional stationary cultivation and dynamic cultivation conditions using a LiveFlow system (In Vitro Technologies). LiveFlow is an advanced system to test the impact of different compounds on the cell cultures, which allows simulation of in vivo conditions thanks to continuous flow of cultivation medium. MHGF-68 was prepared with the infection of BHK-21 cells with MHV-68 virus under non-permissive conditions (41°C). After dynamic cultivation with MHGF-68, we observed changes in morphology on Hepa1c1c7 cells. In cells cultured in a dynamic environment, we observed more pronounced changes in cell morphology in comparison with cells cultured statically. We observed no changes in the cytoskeletal structures in the NIH 3T3 cell line affected by MHGF-68 in both types of cultivation. The advantage of LiveFlow in comparison to in vivo testing is that the experiments performed in this system are less time and money consuming. Dynamic cultivation in the LiveFlow system is suitable for optimizing experiments before testing substances in vivo.

Murine gammaherpesvirus (MHV-68) transforms cultured cells in vitro

Human dermal fibroblasts and mouse NIH/3T3 cells acquired the transformed phenotype ('criss-cross' pattern of growth) after infection with ultraviolet-irradiated murine gammaherpesvirus (MuHV-4 strain 68; MHV-68). These cells with changed phenotype could be serially cultured for 5-6 passages (35-40 days), and then they entered into crisis and most of them died. In a small number of cultures, however, foci of newly transformed cells appeared from which two stable cell lines were derived. After 6-9 cell culture passages of the MHV-68 transformed cell lines, MHV-68 DNA and virus antigen could be detected by PCR and immunofluorescence assay along with the disappearance of actin bundles, indicating that both transformed cell lines might be oncogenic.

An open source based high content screening method for cell biology laboratories investigating cell spreading and adhesion

BACKGROUND

Adhesion dependent mechanisms are increasingly recognized to be important for a wide range of biological processes, diseases and therapeutics. This has led to a rising demand of pharmaceutical modulators. However, most currently available adhesion assays are time consuming and/or lack sensitivity and reproducibility or depend on specialized and expensive equipment often only available at screening facilities. Thus, rapid and economical high-content screening approaches are urgently needed.

RESULTS

We established a fully open source high-content screening method for identifying modulators of adhesion. We successfully used this method to detect small molecules that are able to influence cell adhesion and cell spreading of Swiss-3T3 fibroblasts in general and/or specifically counteract Nogo-A-Δ20-induced inhibition of adhesion and cell spreading. The tricyclic anti-depressant clomipramine hydrochloride was shown to not only inhibit Nogo-A-Δ20-induced cell spreading inhibition in 3T3 fibroblasts but also to promote growth and counteract neurite outgrowth inhibition in highly purified primary neurons isolated from rat cerebellum.

CONCLUSIONS

We have developed and validated a high content screening approach that can be used in any ordinarily equipped cell biology laboratory employing exclusively freely available open-source software in order to find novel modulators of adhesion and cell spreading. The versatility and adjustability of the whole screening method will enable not only centers specialized in high-throughput screens but most importantly also labs not routinely employing screens in their daily work routine to investigate the effects of a wide range of different compounds or siRNAs on adhesion and adhesion-modulating molecules.