PROJECT SUMMARY
In spite of recent new drug developments, platinum-based drugs such as cisplatin are still
widely used to treat solid organ malignancies. Besides its limited efficacy, serious side effects have
been associated with the use of cisplatin, such as bilateral and irreversible hearing loss. In the
cochlea, cisplatin can trigger the production of reactive oxygen species, and activate several other
signaling pathways. A variety of agents, mainly based on their antioxidant properties, have been
tested against cisplatin-induced ototoxicity. However, many of them show limited efficacies, and also
interfere with the therapeutic effect of cisplatin. Extensive in vitro studies have indicated that
flunarizine (Sibelium), a drug that blocks T-type calcium channels, can protect cochlear cells against
cisplatin-induced cytotoxicity. This drug also has strong anti-tumor activities that act synergistically on
several important aspects of cancer treatment. Our preliminary studies have found that flunarizine
can synergistically induce cell death with cisplatin in one lung cancer cell line, and it can also protect
noise-induced hearing loss. Based on these findings, we propose to develop a new cancer drug
combination by testing whether flunarizine can synergistically induce cancer cell death with cisplatin,
and at the same time, prevent cisplatin-induced ototoxicity. Because lung cancer is the leading cause
of cancer-related death globally, and cisplatin is widely used to treat this disease, here, we will first
determine the cytotoxic effects of flunarizine and cisplatin in two lung cancer cell lines: A549 and
H1975, and determine whether flunarizine and cisplatin have synergistic effects in these cancer cells
when used in combination (Aim 1). We will then determine whether flunarizine can prevent cisplatin-
induced ototoxicity in vivo (Aim 2).
In short, based on previous studies and our preliminary data, our project goal is to repurpose
flunarizine to combine with cisplatin against solid tumors with a focus on lung cancer. This project will
generate data important to complete an Investigational New Drug (IND)-enabling data package for
future clinical studies. The ultimate goal is to develop an effective cancer drug combination with fewer
side effects.