KIF15 nanomechanics and kinesin inhibitors, with implications for cancer chemotherapeutics

Area of Science:

• Cell Biology
• Molecular Motor Proteins
• Anticancer Drug Development

Background:

• Eg5 (a mitotic kinesin) is a key target for anticancer drugs, but resistance emerges due to KIF15, another kinesin.
• Limited understanding of KIF15 motor properties hinders the development of effective cancer therapies.
• Mitotic kinesins play crucial roles in cell division and are implicated in cancer progression.

Purpose of the Study:

• To characterize the mechanochemical cycle of the KIF15 motor protein using single-molecule techniques.
• To evaluate the inhibitory effects of KIF15-IN-1 on KIF15 motility and its potential in combination therapy.
• To explore the synergistic effects of inhibiting both Eg5 and KIF15 on cancer cell viability.

Main Methods:

• Single-molecule optical-trapping to define the KIF15 mechanochemical cycle.
• Assessment of KIF15-IN-1 as a small-molecule inhibitor of KIF15 motility.
• Microtubule (MT)-gliding assays and cancer cell viability assays using combinations of Eg5 and KIF15 inhibitors.

Main Results:

• KIF15 exhibits distinct motility characteristics compared to Eg5.
• KIF15-IN-1 demonstrates potent inhibition of KIF15 motor activity.
• Combined inhibition of Eg5 and KIF15 is required to completely halt MT gliding and synergistically reduces cancer cell growth.

Conclusions:

• KIF15 is a critical motor protein involved in mitotic processes and cancer cell survival.
• KIF15-IN-1 is an effective inhibitor of KIF15, offering a potential therapeutic avenue.
• Combination therapy targeting both Eg5 and KIF15 presents a promising strategy to overcome drug resistance in cancer treatment.