Bisoprolol is a class of β-blocker drugs which are selective on β1
receptors. β-blocker has a role as a new therapeutic agent to reduce tumor
metastases, to prevent recurrence and death which caused by cancer. The study
wich has been conducted, involving β-adenergic receptors as an important
mediator for growth and invasive of several cancers, including lung, prostate,
colon, stomach, breast, and ovarian cancer. Preclinical study stated that β-
adrenergic receptors which were blocked by β-blockers could inhibit various
cellular processes which involved in the breast cancer progress, including tumor
cell proliferation, metastasis, and apoptosis progresses. Doxorubicin was one of
the most widely used chemotherapy agents in the breast cancer treatment, but it
caused side effects such as hepatotoxicity, cardiotoxicity and resistance risk. This
study aims to determine the effect of bisoprolol in increasing the sensitivity of
T47D cancer cells as doxorubicin co-chemotherapy agents. The cytotoxic test was
conducted to obtain IC50 scores and the cell proliferation blocking (doubling time
test) by using the MTT assay method. Based on bisoprolol cytotoxic test, there
obtained IC50 of 349.25 μM which was moderate cytotoxic. The combination of
bisoprolol and doxorubicin at high concentration has a synergistic potential effect
(CI 0.1-0.3), whereas at low concentrations, it caused a mild-moderate antagonist
effect (CI> 1). The anti-proliferation effect on the combination of bisoprolol and
doxorubicin was not as strong as the single doxorubicin. However, the
combination of bisopolol and doxorubicin has anti-proliferation potency, it could
be seen that with a ½ dose concentration, it could block the cell growth which was
approaching the full dosage concentration. Based on the tests, the combination of
bisoprolol and doxorubicin potential as a co-chemotherapy for breast cancer.