Inhibition of chaperone‑mediated autophagy reduces tumor growth and metastasis and promotes drug sensitivity in colorectal cancer

Abstract

Chaperone‑mediated autophagy (CMA) is a selec‑ tive type of autophagy whereby a specific subset of intracellular proteins is targeted to the lysosome for degradation. The present study investigated the mechanisms underlying the response and resistance to 5‑fluorouracil (5‑FU) in colorectal cancer (CRC) cell lines. In engineered 5‑FU‑resistant CRC cell lines, a signif‑ icant elevation of lysosome‑associated membrane protein 2A (LAMP2A), which is the key molecule in the CMA pathway, was identified. High expression of LAMP2A was found to be responsible for 5‑FU resistance and to enhance PLD2 expres‑ sion through the activation of NF‑κB pathway. Accordingly, loss or gain of function of LAMP2A in 5‑FU‑resistant CRC cells rendered them sensitive or resistant to 5‑FU, respectively. Taken together, the results of the present study suggested that chemoresistance in patients with CRC may be mediated by enhancing CMA. Thus, CMA is a promising predictor of chemosensitivity to 5‑FU treatment and anti‑CMA therapy may be a novel therapeutic option for patients with CRC.