Study on the predictive value of Tom1L1 in the efficacy of neoadjuvant chemotherapy for locally progressive mid-low rectal cancer

Abstract

Abstract Objective: To investigate the specificity of Tom1L1 (Target of Myb1-Like1) expression in colorectal cancerous tissues and its correlation with pathological characteristics and to analyze the predictive value of Tom1L1 in the efficacy of neoadjuvant chemotherapy for patients with locally progressive mid-low rectal cancer. Methods: Genes with differential expression in colorectal cancerous tissues and paracancerous normal tissues were screened via bioinformatics analysis and then subjected to functional prediction. The cancerous tissues and paracancerous normal tissues of 102 patients diagnosed with colorectal cancer without treatment were selected; quantitative polymerase chain reaction (qPCR) was applied to detect the relative expression of Tom1L1 mRNA in the two groups; Western blot and immunohistochemistry (IHC) were adopted to validate the expression level of Tom1L1 protein in the two groups and to analyze its relationship with clinicopathological characteristics. Furthermore, the pretreatment biopsy tissue wax blocks of 34 patients with locally progressive mid-low rectal cancer, who were treated with neoadjuvant Xelox chemotherapy prior to the operation, were selected as the pretreatment group, and the postoperative pathological tissue wax blocks of the same patients were taken as the post-treatment group. The tumor regression grade (TRG) was applied to evaluate the pathological response of the patients’ tumors after neoadjuvant chemotherapy; IHC was adopted to detect the expression of Tom1L1 protein in the two groups and to analyze the relationship between the expression level of Tom1L1 and the sensitivity of neoadjuvant therapy. Results: qPCR results showed that the relative expression of Tom1L1 mRNA in colorectal cancerous tissues was higher than that in paracancerous normal tissues, with a statistically significant difference (P < 0.01); the results of Western blot and IHC showed that the expression of Tom1L1 protein in colorectal cancerous tissues was significantly higher than that in paracancerous normal tissues, with a statistically significant difference (P < 0.01); 20 out of 34 patients (58.82%) receiving neoadjuvant chemotherapy responded to the therapy; neoadjuvant chemotherapy was significantly more effective in patients with low expression of Tom1L1 protein than in those with high expression of Tom1L1 protein, with a statistically significant difference (P < 0.05). Conclusions: Tom1L1 is highly expressed in colorectal cancerous tissues and is involved in the onset and progression of colorectal cancer; neoadjuvant Xelox chemotherapy can have an impact on Tom1L1 expression in progressive rectal cancer; patients with locally progressive mid-low rectal cancer who have low Tom1L1 expression are more sensitive to neoadjuvant chemotherapy.