Colorectal cancer (CRC) is a common digestive tract tumor 1.It is the third leading cause of death in the world. Overall 5-year survival rate is less than 40%, and the occurrence is rising 2. However, the prognosis and therapy have not been significantly improved. Therefore, a proper selection of patients for aggressive treatment is necessary, new therapeutic and prognostic strategies are urgently needed 3.
Autophagy is a pathway for self-digestion, in which unwanted cytoplasmic components are recycled 4.In normal conditions, autophagy is essential for cellular homeostasis 5. Autophagy has dual roles in cancer cells, stimulation or suppression , with effects on progression and oncogenesis 6.Recent research established that autophagy is important target for controlling cancer depending on stage and type of tumor 7.Diverse molecular mechanisms contribute to cancer cells resistance to treatment 8.Among these mechanisms , autophagy appears to be critical 9.
EIF4EBP1 (Eukaryotic translation initiation factor 4E-binding protein 1) is encoded by EIF4EBP1 gene.It acts as an effector in mTOR (mammilian target of rapamycin) pathway which on activation ,EIF4EBP1 is phosphorylated promoting cell proliferation 10. Studies have suggested that EIF4EBP1 promotes carcinogenesis as in hepatocellular carcinoma .However, its role in CRC have not been elucidated 10.
Long non-coding RNAs (lncRNAs) are group of RNA , 200 nucleotides in length 11,. Expression of lncRNAs has been discovered in multiple tumors, acting as oncogenes. 'HOXA(hydrogenase transcriptional regulatory protein) transcript at the distal tip' (HOTTIP) has received attention lately.It is up-regulated in CRC tissue, regulating genes via epigenetic modification. Therefore, it might be a candidate for cancerization and therapy of CRC 12.
Expression of lncRNAs could be affected by single nucleotide polymorphisms (SNPs), the most common genetic variation in human genomes13. rs1859168 was reported as a potential functional polymorphism on HOTTIP that alters its expression level 14.. Also, it was recently reported that HOTTIP enhances interleukin 6 expression, which potentiates immune escape of cancer cells 15.
