Adaptation to statins restricts human tumour growth in Nude mice

Julie Follet,Pierrick Auvray,Vincent Hesry,Laurent Corcos,Lionel Rémy,Brigitte Simon,Catherine Le Jossic-Corcos,Danièle Gillet

doi:10.1186/1471-2407-11-491

Abstract

BackgroundStatins have long been used as anti-hypercholesterolemia drugs, but numerous lines of evidence suggest that they may also bear anti-tumour potential. We have recently demonstrated that it was possible to isolate cancer cells adapted to growth in the continuous presence of lovastatin. These cells grew more slowly than the statin-sensitive cells of origin. In the present study, we compared the ability of both statin-sensitive and statin-resistant cells to give rise to tumours in Nude mice.MethodsHGT-1 human gastric cancer cells and L50 statin-resistant derivatives were injected subcutaneously into Nude mice and tumour growth was recorded. At the end of the experiment, tumours were recovered and marker proteins were analyzed by western blotting, RT-PCR and immunohistochemistry.ResultsL50 tumours grew more slowly, showed a strong decrease in cyclin B1, over-expressed collagen IV, and had reduced laminin 332, VEGF and CD34 levels, which, collectively, may have restricted cell division, cell adhesion and neoangiogenesis.ConclusionsTaken together, these results showed that statin-resistant cells developed into smaller tumours than statin-sensitive cells. This may be reflective of the cancer restricting activity of statins in humans, as suggested from several retrospective studies with subjects undergoing statin therapy for several years.

Highlights

Statins have long been used as anti-hypercholesterolemia drugs, but numerous lines of evidence suggest that they may bear anti-tumour potential
Our results showed that tumour growth was slower in L50 than in HGT-1 tumours, as found for cells grown in vitro
1-Statin-resistant cells grow more slowly in Nude mice We have previously shown that L50 cells had a slower growth rate in vitro than HGT-1 cells [11]

Summary

Methods

Cell culture HGT-1 human gastric cancer cells and HGT-1-derived L50 cells were grown at 37°C under a humidified atmosphere of 5% CO2 in DMEM (Dulbecco’s modified Eagle’s medium) (Lonza, Saint Beauzire, France), containing 4.5 g.L-1 glucose and supplemented with 5% (v/v) foetal bovine serum without antibiotics (GibcoInvitrogen, Cergy Pontoise, France) [11,13]. Mice were observed for 2 h post-injection to ascertain that no health condition occurred. Protein extraction and western blotting analysis Frozen tumours were rapidly homogenised in Phosphate Buffered Saline (PBS) and lysed in ripa buffer (50 mM Tris HCl pH7.4, 150 mM NaCl, 0.5% (wt/v) Sodium deoxycholate, 0.1% SDS, 1% NP40, 1 mM EDTA, 1 mM PMSF) containing protease inhibitor cocktail (Roche, Meylan, France) and phosphatase inhibitor (Active motif) for 10 min at 4°C. The labelling analysis was performed blindly, and the tissue sections (serial sections) were exposed blindly to the antibodies and read by two independent observers with at least 20 microscopic fields per condition. RNA extraction and RT-PCR analysis Total RNA was isolated using Trizol (Invitrogen, CergyPontoise, France) and the RNA samples were used for the first-strand cDNA synthesis with the High Capacity cDNA Reverse Transcription kit and random hexamer primers (Applied biosystems). The primer sequences and reaction conditions will be provided upon request

Conclusions

Background

Results and discussion

Conclusion

Katz MS: Therapy insight