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Antitumoral efficacy of the protease inhibitor gabexate mesilate in colon cancer cells harbouring KRAS, BRAF and PIK3CA mutations.

Brandi G, Tavolari S, De Rosa F, Di Girolamo S, Agostini V, Barbera MA, Frega G, Biasco G - PLoS ONE (2012)

Bottom Line: However, this therapy is poorly effective or ineffective in unselected patients.Notably, the antitumoral efficacy of gabexate mesilate and cetuximab in combination was found to be not superior than that observed with gabexate mesilate as single agent.Further studies to better elucidate gabexate mesilate mechanism of action in CRC cells are therefore warranted.

View Article: PubMed Central - PubMed

Affiliation: L. and A. Seràgnoli Department of Hematology and Oncological Sciences, Sant'Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy. giovanni.brandi@unibo.it

ABSTRACT
The employment of anti-epidermal growth factor receptor (EGFR) antibodies represents a backbone of the therapeutic options for the treatment of metastatic colorectal cancer (mCRC). However, this therapy is poorly effective or ineffective in unselected patients. Mutations in KRAS, BRAF and PIK3CA genes have recently emerged as the best predictive factors of low/absent response to EGFR-targeted therapy. Due to the need for efficacious treatment options for mCRC patients bearing these mutations, in this short report we examined the antitumoral activity of the protease inhibitor gabexate mesilate, alone and in combination with the anti-EGFR monoclonal antibody cetuximab, in a panel of human CRC cell lines harbouring a different expression pattern of wild-type/mutated KRAS, BRAF and PIK3CA genes. Results obtained showed that gabexate mesilate significantly inhibited the growth, invasive potential and tumour-induced angiogenesis in all the CRC cells employed in this study (including those ones harbouring dual KRAS/PIK3CA or BRAF/PIK3CA mutation), while cetuximab affected these parameters only in CRC cells with KRAS, BRAF and PIK3CA wild-type. Notably, the antitumoral efficacy of gabexate mesilate and cetuximab in combination was found to be not superior than that observed with gabexate mesilate as single agent. Overall, these preliminary findings suggest that gabexate mesilate could represent a promising therapeutic option for mCRC patients, particularly for those harbouring KRAS, BRAF and PIK3CA mutations, either as mono-therapy or in addition to standard chemotherapy regimens. Further studies to better elucidate gabexate mesilate mechanism of action in CRC cells are therefore warranted.

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Effect of gabexate mesilate and cetuximab, alone and in combination, on CRC conditioned medium-induced angiogenesis.Evaluation by in vitro Matrigel angiogenesis assay of EA.hy926 endothelial cell differentiation in capillary-like structures after 24 hrs incubation with the conditioned medium of CACO-2, SW48, HT-29, Colo205, SW480, SW620, RKO, LS174T and HCT-116 cells, previously treated for 6 hrs with cetuximab 100 µg/ml and gabexate mesilate 1 mM, alone and in combination. Tube formation index was assessed as described in Material and Methods section. For each cell line, the mean value of untreated samples was assumed as 100% and mean values of treated cells were plotted as percentages with respect to their matched controls. Photographs are representative of three independent experiments with similar findings. Cetux: cetuximab; GM: gabexate mesilate. Scale bar: 50 µm. *p<0.05; **p<0.001; ***p : not significant.
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pone-0041347-g003: Effect of gabexate mesilate and cetuximab, alone and in combination, on CRC conditioned medium-induced angiogenesis.Evaluation by in vitro Matrigel angiogenesis assay of EA.hy926 endothelial cell differentiation in capillary-like structures after 24 hrs incubation with the conditioned medium of CACO-2, SW48, HT-29, Colo205, SW480, SW620, RKO, LS174T and HCT-116 cells, previously treated for 6 hrs with cetuximab 100 µg/ml and gabexate mesilate 1 mM, alone and in combination. Tube formation index was assessed as described in Material and Methods section. For each cell line, the mean value of untreated samples was assumed as 100% and mean values of treated cells were plotted as percentages with respect to their matched controls. Photographs are representative of three independent experiments with similar findings. Cetux: cetuximab; GM: gabexate mesilate. Scale bar: 50 µm. *p<0.05; **p<0.001; ***p : not significant.

Mentions: Lastly, we assessed the effect of cetuximab and gabexate mesilate on tumour-induced angiogenesis. A very strong inhibitory effect on this parameter was observed when we examined the action of gabexate mesilate alone. Indeed, 24 hrs incubation of EA.hy926 cells with the conditioned medium of CACO-2, SW48, HT-29, Colo205, SW480, SW620, RKO, LS174T and HCT-116 cells, previously treated for 6 hrs with this drug at the dose of 1 mM, almost completely inhibited endothelial cell differentiation in capillary-like structures, as indicated by the presence of an interconnected network of anastomosing cells in control samples and of spherical cells, isolated or aggregated in small clumps, in treated ones (Figure 3). Also on this parameter, cetuximab alone (100 µg/ml) was found to be moderately effective only in CRC cell lines with wild-type KRAS, BRAF and PIK3CA genes (inhibition of tube formation index, 22% and 20% on CACO-2 and SW48 cells, respectively). Due to the strong inhibition of tumor-induced angiogenesis by gabexate mesilate alone at the dose 1 mM, the effect of this drug alone and in combination with cetuximab was also assessed at the dose of 0.1 and 0.5 mM. However, also at these doses, the anti-angiogenic effect displayed by gabexate mesilate plus cetuximab was not superior than that observed with gabexate mesilate employed as single agent (data not shown).


Antitumoral efficacy of the protease inhibitor gabexate mesilate in colon cancer cells harbouring KRAS, BRAF and PIK3CA mutations.

Brandi G, Tavolari S, De Rosa F, Di Girolamo S, Agostini V, Barbera MA, Frega G, Biasco G - PLoS ONE (2012)

Effect of gabexate mesilate and cetuximab, alone and in combination, on CRC conditioned medium-induced angiogenesis.Evaluation by in vitro Matrigel angiogenesis assay of EA.hy926 endothelial cell differentiation in capillary-like structures after 24 hrs incubation with the conditioned medium of CACO-2, SW48, HT-29, Colo205, SW480, SW620, RKO, LS174T and HCT-116 cells, previously treated for 6 hrs with cetuximab 100 µg/ml and gabexate mesilate 1 mM, alone and in combination. Tube formation index was assessed as described in Material and Methods section. For each cell line, the mean value of untreated samples was assumed as 100% and mean values of treated cells were plotted as percentages with respect to their matched controls. Photographs are representative of three independent experiments with similar findings. Cetux: cetuximab; GM: gabexate mesilate. Scale bar: 50 µm. *p<0.05; **p<0.001; ***p : not significant.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3404056&req=5

pone-0041347-g003: Effect of gabexate mesilate and cetuximab, alone and in combination, on CRC conditioned medium-induced angiogenesis.Evaluation by in vitro Matrigel angiogenesis assay of EA.hy926 endothelial cell differentiation in capillary-like structures after 24 hrs incubation with the conditioned medium of CACO-2, SW48, HT-29, Colo205, SW480, SW620, RKO, LS174T and HCT-116 cells, previously treated for 6 hrs with cetuximab 100 µg/ml and gabexate mesilate 1 mM, alone and in combination. Tube formation index was assessed as described in Material and Methods section. For each cell line, the mean value of untreated samples was assumed as 100% and mean values of treated cells were plotted as percentages with respect to their matched controls. Photographs are representative of three independent experiments with similar findings. Cetux: cetuximab; GM: gabexate mesilate. Scale bar: 50 µm. *p<0.05; **p<0.001; ***p : not significant.
Mentions: Lastly, we assessed the effect of cetuximab and gabexate mesilate on tumour-induced angiogenesis. A very strong inhibitory effect on this parameter was observed when we examined the action of gabexate mesilate alone. Indeed, 24 hrs incubation of EA.hy926 cells with the conditioned medium of CACO-2, SW48, HT-29, Colo205, SW480, SW620, RKO, LS174T and HCT-116 cells, previously treated for 6 hrs with this drug at the dose of 1 mM, almost completely inhibited endothelial cell differentiation in capillary-like structures, as indicated by the presence of an interconnected network of anastomosing cells in control samples and of spherical cells, isolated or aggregated in small clumps, in treated ones (Figure 3). Also on this parameter, cetuximab alone (100 µg/ml) was found to be moderately effective only in CRC cell lines with wild-type KRAS, BRAF and PIK3CA genes (inhibition of tube formation index, 22% and 20% on CACO-2 and SW48 cells, respectively). Due to the strong inhibition of tumor-induced angiogenesis by gabexate mesilate alone at the dose 1 mM, the effect of this drug alone and in combination with cetuximab was also assessed at the dose of 0.1 and 0.5 mM. However, also at these doses, the anti-angiogenic effect displayed by gabexate mesilate plus cetuximab was not superior than that observed with gabexate mesilate employed as single agent (data not shown).

Bottom Line: However, this therapy is poorly effective or ineffective in unselected patients.Notably, the antitumoral efficacy of gabexate mesilate and cetuximab in combination was found to be not superior than that observed with gabexate mesilate as single agent.Further studies to better elucidate gabexate mesilate mechanism of action in CRC cells are therefore warranted.

View Article: PubMed Central - PubMed

Affiliation: L. and A. Seràgnoli Department of Hematology and Oncological Sciences, Sant'Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy. giovanni.brandi@unibo.it

ABSTRACT
The employment of anti-epidermal growth factor receptor (EGFR) antibodies represents a backbone of the therapeutic options for the treatment of metastatic colorectal cancer (mCRC). However, this therapy is poorly effective or ineffective in unselected patients. Mutations in KRAS, BRAF and PIK3CA genes have recently emerged as the best predictive factors of low/absent response to EGFR-targeted therapy. Due to the need for efficacious treatment options for mCRC patients bearing these mutations, in this short report we examined the antitumoral activity of the protease inhibitor gabexate mesilate, alone and in combination with the anti-EGFR monoclonal antibody cetuximab, in a panel of human CRC cell lines harbouring a different expression pattern of wild-type/mutated KRAS, BRAF and PIK3CA genes. Results obtained showed that gabexate mesilate significantly inhibited the growth, invasive potential and tumour-induced angiogenesis in all the CRC cells employed in this study (including those ones harbouring dual KRAS/PIK3CA or BRAF/PIK3CA mutation), while cetuximab affected these parameters only in CRC cells with KRAS, BRAF and PIK3CA wild-type. Notably, the antitumoral efficacy of gabexate mesilate and cetuximab in combination was found to be not superior than that observed with gabexate mesilate as single agent. Overall, these preliminary findings suggest that gabexate mesilate could represent a promising therapeutic option for mCRC patients, particularly for those harbouring KRAS, BRAF and PIK3CA mutations, either as mono-therapy or in addition to standard chemotherapy regimens. Further studies to better elucidate gabexate mesilate mechanism of action in CRC cells are therefore warranted.

Show MeSH
Related in: MedlinePlus