Biomedicine & Pharmacotherapy
Synergistic effect of pyrazoles derivatives and doxorubicin in claudin-low
breast cancer subtype
,
Cláudio Martin Pereira de Pereirac, Tiago Collaresa,b,c, Fabiana Kömmling Seixasa,b,
a
Programa de Pós-Graduação Em Biotecnologia (PPGB), Biotecnologia/Centro de Desenvolvimento Tecnológico, Universidade Federal de Pelotas, Pelotas, RS, Brazil
b
Grupo de Pesquisa Em Oncologia Celular E Molecular (GPO), Laboratório de Biotecnologia Do Câncer, Centro de Desenvolvimento Tecnológico, Universidade Federal de
Pelotas, Pelotas, RS, Brazil
c
Programa de Pós-Graduação Em Bioquímica E Bioprospecção, UFPel, Pelotas, Brazil
A R T I C L E I N F O
A B S T R A C T
Keywords:
Triple negative
Claudin-low
Pyrazole
Bromine
Chlorine
Background: Breast cancer is a global public health problem. For some subtypes, such as Claudin-low, the
prognosis is poorer and the treatment is still a challenge. Pyrazoles are an important class of heterocyclic
compounds and are promising anticancer agents based on their chemical properties. The present study was
aimed not only at testing pyrazoles previously prepared by our research group in two breast cancer cell lines
characterized by intermediated response to conventional chemotherapy but also at analyzing the possible sy-
nergistic effect of these pyrazoles associated with doxorubicin.
Methods: Four 1-thiocarbamoyl-3,5-diaryl-4,5-dihydro-1H pyrazoles were tested for the first time in MCF-7 and
MDA-MB-231 culture cells. The pyrazoles with best results in cytotoxicity were used in combination with
doxorubicin and compared with this drug alone as standard. The synergic effect was analyzed using Combination
Index method. In addition, cell death and apoptosis assays were carried out.
Results: Two pyrazoles with cytotoxic effect in MCF-7 and especially in MDA-MB-231 were identified. This
activity was markedly higher in pyrazoles containing bromine and chlorine substituents. The combination of
these pyrazoles with doxorubicin had a significant synergic effect in both cells tested and mainly in MDA-MB-
231. These data were confirmed with apoptosis and cell death analysis.
Conclusions: The synergic effect observed with combination of these pyrazoles and doxorubicin deserves special
attention in Claudin-low breast cancer subtype. This should be explored in order to improve treatment results
and minimize side effects.
1. Introduction
are found into the bigger subset of triple negative tumors which lack the
expression of estrogen, progesterone receptor (ER/PR) and do not ex-
Breast cancer remains a disease of high prevalence and is the most
frequently diagnosed cancer worldwide. In some countries, this is the
leading cause of women cancer-related death [1,2]. This entity re-
presents a heterogeneous disease, classified in distinct subsets by gene
expression signature with important implications for treatment, re-
sponses and outcome. The choice of appropriate therapy and prognosis
depends on a number of factors including the molecular subtype of the
pathology, which is important for the identification of predictive factors
for response to a given treatment [3–5].
hibit amplification of the human epidermal growth factor receptor 2
(HER2) gene. MDA-MB 231 cell line is an example of Claudin low
subtype with a low expression of Ki67, E-cadherin, claudin-3, claudinin-
4 and claudinin-7, while MCF-7 represents the luminal breast cancer
cell line, with expression of ER, HER2 negative, PR expression or not
and low Ki67 [9,10]. Despite the therapeutic and molecular advances of
recent years, there is no validated target to be blocked in the triple
negative subset and chemotherapy is the only available systemic
therapy [11]. Currently, taxane and anthracycline-based combination
chemotherapy remains the standard treatment approach for triple ne-
gative subtype, and this approach has not changed much in the last
decade [[17],12,13]. Doxorubicin is an anthracycline antibiotic
Basal-like and Claudin-low subtypes, represent about 19% of all
breast cancers including those with worst prognosis due to its ag-
gressive and metastatic nature and high rates of relapse [6–8]. These
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Corresponding author at: Universidade Federal de Pelotas, Campus Universitário S/N, Capão Do Leão, RS, Cep: 96010-900, Brazil.
Received 30 September 2017; Received in revised form 20 November 2017; Accepted 14 December 2017