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Combination of cetuximab with chemoradiation, trastuzumab or MAPK inhibitors: mechanisms of sensitisation of cervical cancer cells.

Meira DD, de Almeida VH, Mororó JS, Nóbrega I, Bardella L, Silva RL, Albano RM, Ferreira CG - Br. J. Cancer (2009)

Bottom Line: Cetuximab efficiently decreased MAPK and AKT phosphorylation in A431 cells but slightly less in Caski and C33A cells.In Caski, but not in C33A cells, cetuximab cooperated with the TKI, reducing cell survival and AKT and MAPK phosphorylation.However, cetuximab with trastuzumab or PD98059 reduced survival and MAPK phosphorylation of both cell lines.

View Article: PubMed Central - PubMed

Affiliation: Division of Clinical Research, Research Coordination, Instituto Nacional de Câncer (INCA), Rio de Janeiro, Cep: 20231-050, RJ, Brazil.

ABSTRACT

Background: Cervical cancer (CC) annually kills 288,000 women worldwide. Unfortunately, responses to chemoradiation are partial and are of short duration. As anti-EGFR monoclonal antibodies sensitise tumours, we investigated cetuximab's toxicity plus chemoradiation on CC cells, which express different EGFR levels.

Methods: EGFR, HER2, AKT and MAPK expression and phosphorylation status were determined by western blotting. Cytotoxicity was assessed by MTT or clonogenic assays (CA) in cell lines treated with cetuximab alone or in combinations.

Results: Cetuximab with cisplatin and radiation achieved maximum cytotoxic effects for A431, Caski and C33A cells (high, intermediate and low EGFR expression, respectively) in CA. Cetuximab efficiently decreased MAPK and AKT phosphorylation in A431 cells but slightly less in Caski and C33A cells. To check whether further EGFR, HER2 or MAPK inhibition would improve cetuximab's cytotoxicity, we combined it with an EGFR tyrosine kinase inhibitor (TKI), trastuzumab or a MEK1/2 inhibitor (PD98059). In Caski, but not in C33A cells, cetuximab cooperated with the TKI, reducing cell survival and AKT and MAPK phosphorylation. However, cetuximab with trastuzumab or PD98059 reduced survival and MAPK phosphorylation of both cell lines.

Conclusion: Our data suggest that cetuximab combined with chemoradiation, trastuzumab or MAPK inhibitors has useful applications for CC treatment, independently of EGFR expression.

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Related in: MedlinePlus

Effects of cetuximab (100 μg ml−1) alone or combined with cisplatin (1.0, 0.5 and 0.15 μM for A431, Caski and C33A cells, respectively) and/or RxT (2.0, 1.5 and 0.3 Gy for A431, Caski and C33A cells, respectively) on survival in CA. (A) A431, (B) Caski and (C) C33A cells. (D) Representative picture of A431 cells under different treatments as described in material and methods. One-way analysis of variance (ANOVA) with Tukey's post test *P<0.05, when compared to control cells.
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fig2: Effects of cetuximab (100 μg ml−1) alone or combined with cisplatin (1.0, 0.5 and 0.15 μM for A431, Caski and C33A cells, respectively) and/or RxT (2.0, 1.5 and 0.3 Gy for A431, Caski and C33A cells, respectively) on survival in CA. (A) A431, (B) Caski and (C) C33A cells. (D) Representative picture of A431 cells under different treatments as described in material and methods. One-way analysis of variance (ANOVA) with Tukey's post test *P<0.05, when compared to control cells.

Mentions: We evaluated whether the combination of cetuximab (100 μg ml−1) with RxT and/or cisplatin could enhance the cytotoxic effects observed in CA. Isolated cetuximab, cisplatin and RxT treatments decreased the survival of all cell lines (Figures 2A–D) but the combination of cetuximab with either RxT or cisplatin enhanced these effects (P<0.05). Furthermore, the triple combination of cetuximab, cisplatin and RxT achieved maximum effects for all cell lines in CA (demonstrative pictures of A431 cells are shown in Figure 2D). Caski cells are HPV-positive and express intermediate levels of EGFR and HER2, resembling typical CC tumours. In this cell line, the triple combination reached up to 70% inhibition in CA (Figure 2B) whereas in C33A cells, an inhibition of 60% was observed (Figure 2C).


Combination of cetuximab with chemoradiation, trastuzumab or MAPK inhibitors: mechanisms of sensitisation of cervical cancer cells.

Meira DD, de Almeida VH, Mororó JS, Nóbrega I, Bardella L, Silva RL, Albano RM, Ferreira CG - Br. J. Cancer (2009)

Effects of cetuximab (100 μg ml−1) alone or combined with cisplatin (1.0, 0.5 and 0.15 μM for A431, Caski and C33A cells, respectively) and/or RxT (2.0, 1.5 and 0.3 Gy for A431, Caski and C33A cells, respectively) on survival in CA. (A) A431, (B) Caski and (C) C33A cells. (D) Representative picture of A431 cells under different treatments as described in material and methods. One-way analysis of variance (ANOVA) with Tukey's post test *P<0.05, when compared to control cells.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2736849&req=5

fig2: Effects of cetuximab (100 μg ml−1) alone or combined with cisplatin (1.0, 0.5 and 0.15 μM for A431, Caski and C33A cells, respectively) and/or RxT (2.0, 1.5 and 0.3 Gy for A431, Caski and C33A cells, respectively) on survival in CA. (A) A431, (B) Caski and (C) C33A cells. (D) Representative picture of A431 cells under different treatments as described in material and methods. One-way analysis of variance (ANOVA) with Tukey's post test *P<0.05, when compared to control cells.
Mentions: We evaluated whether the combination of cetuximab (100 μg ml−1) with RxT and/or cisplatin could enhance the cytotoxic effects observed in CA. Isolated cetuximab, cisplatin and RxT treatments decreased the survival of all cell lines (Figures 2A–D) but the combination of cetuximab with either RxT or cisplatin enhanced these effects (P<0.05). Furthermore, the triple combination of cetuximab, cisplatin and RxT achieved maximum effects for all cell lines in CA (demonstrative pictures of A431 cells are shown in Figure 2D). Caski cells are HPV-positive and express intermediate levels of EGFR and HER2, resembling typical CC tumours. In this cell line, the triple combination reached up to 70% inhibition in CA (Figure 2B) whereas in C33A cells, an inhibition of 60% was observed (Figure 2C).

Bottom Line: Cetuximab efficiently decreased MAPK and AKT phosphorylation in A431 cells but slightly less in Caski and C33A cells.In Caski, but not in C33A cells, cetuximab cooperated with the TKI, reducing cell survival and AKT and MAPK phosphorylation.However, cetuximab with trastuzumab or PD98059 reduced survival and MAPK phosphorylation of both cell lines.

View Article: PubMed Central - PubMed

Affiliation: Division of Clinical Research, Research Coordination, Instituto Nacional de Câncer (INCA), Rio de Janeiro, Cep: 20231-050, RJ, Brazil.

ABSTRACT

Background: Cervical cancer (CC) annually kills 288,000 women worldwide. Unfortunately, responses to chemoradiation are partial and are of short duration. As anti-EGFR monoclonal antibodies sensitise tumours, we investigated cetuximab's toxicity plus chemoradiation on CC cells, which express different EGFR levels.

Methods: EGFR, HER2, AKT and MAPK expression and phosphorylation status were determined by western blotting. Cytotoxicity was assessed by MTT or clonogenic assays (CA) in cell lines treated with cetuximab alone or in combinations.

Results: Cetuximab with cisplatin and radiation achieved maximum cytotoxic effects for A431, Caski and C33A cells (high, intermediate and low EGFR expression, respectively) in CA. Cetuximab efficiently decreased MAPK and AKT phosphorylation in A431 cells but slightly less in Caski and C33A cells. To check whether further EGFR, HER2 or MAPK inhibition would improve cetuximab's cytotoxicity, we combined it with an EGFR tyrosine kinase inhibitor (TKI), trastuzumab or a MEK1/2 inhibitor (PD98059). In Caski, but not in C33A cells, cetuximab cooperated with the TKI, reducing cell survival and AKT and MAPK phosphorylation. However, cetuximab with trastuzumab or PD98059 reduced survival and MAPK phosphorylation of both cell lines.

Conclusion: Our data suggest that cetuximab combined with chemoradiation, trastuzumab or MAPK inhibitors has useful applications for CC treatment, independently of EGFR expression.

Show MeSH
Related in: MedlinePlus