Concurrent radiotherapy and chemotherapy is a widely used, comprehensive treatment for rectal cancer. By studying the impact of concurrent chemoradiotherapy on the invasion and migration of colorectal cancer (CRC) cells and researching the associated molecular mechanisms, the present study aimed to provide a novel method to improve the therapeutic effect of this treatment against CRC. Human HCT116 and HT29 CRC cells were simultaneously treated with 4 Gy of 6 MV X-rays and 10 µmol/l 5-fluorouracil to establish a residual cell model. Transwell migration and invasion experiments were used to analyse the invasion and migration of the cells. The expression of long non-coding (lnc)RNAs was detected using a gene chip, and reverse transcription-quantitative polymerase chain reaction analysis was used to determine lncRNA expression levels. Specific small interfering RNAs were transfected into HCT116 residual cells to silence the expression of the identified key genes. The migration and invasion of residual CRC cells were demonstrated to be significantly increased compared with the original cells. Pvt1 oncogene, long-chain non-protein-coding RNA 152 (LINC00152), and MIR22 host gene were selected as potential targets. However, the migration and invasion of residual HCT116 cancer cells were only significantly decreased following silencing of LINC00152 expression. LINC00152 may therefore be a potential biomarker involved in modulation of the biological characteristics of residual CRC cells following chemoradiotherapy.
Keywords: chemotherapy; colorectal cancer cells; invasion; metastasis; radiotherapy.