Knockdown of focal adhesion kinase reverses colon carcinoma multicellular resistance

Area of Science:

• Oncology
• Molecular Biology
• Drug Resistance Research

Background:

• Chemotherapy resistance is a significant challenge in treating solid tumors, impacting treatment efficacy.
• Multicellular spheroids (MCSs) serve as a valuable in vitro model for studying drug resistance mechanisms.
• Focal adhesion kinase (FAK) is implicated in various cellular processes, including cancer progression.

Purpose of the Study:

• To investigate the role of focal adhesion kinase (FAK) in 5-fluorouracil (5-FU) chemoresistance in colon carcinoma multicellular spheroids (MCSs).
• To evaluate the therapeutic potential of targeting FAK to overcome 5-FU resistance in vitro and in vivo.

Main Methods:

• Utilized small hairpin RNA (shRNA) to specifically inhibit FAK expression in colon carcinoma MCSs.
• Assessed the effect of FAK silencing on 5-FU sensitivity, apoptosis, and key signaling pathways (Akt, NF-kappaB).
• Evaluated the impact of FAK knockdown on tumor growth and 5-FU sensitivity in a nude mouse xenograft model.

Main Results:

• FAK suppression did not affect spheroid cell proliferation but significantly enhanced 5-FU-induced cytotoxicity.
• Silencing FAK reduced the IC(50) of 5-FU and increased apoptosis, correlating with decreased Akt and NF-kappaB levels.
• Knockdown of FAK inhibited tumor growth and sensitized tumors to 5-FU in vivo.

Conclusions:

• RNA interference targeting FAK potentiates 5-FU-induced cytotoxicity in colon cancer models, both in vitro and in vivo.
• FAK suppression partially reverses multicellular resistance to 5-FU, likely by suppressing Akt/NF-kappaB activity.
• Targeting FAK represents a promising strategy to enhance the efficacy of 5-FU chemotherapy in colon cancer.