miR-34a mediates oxaliplatin resistance of colorectal cancer cells by inhibiting macroautophagy via transforming growth factor-β/Smad4 pathway

Figure 1 miR-34a levels were significantly decreased after oxaliplatin treatment. A: Analysis of miR-34a expression was performed on blood samples from 30 colorectal cancer (CRC) patients after oxaliplatin (OXA)-based combination chemotherapy. Total RNA was extracted and subjected to qRT-PCR to analyze the expression level of miR-34a in each sample. U6 was used as an internal control; B and C: mRNA expression levels of Smad4 and TGF-β in the blood samples from CRC patients were measured by qRT-PCR. β-actin was used as the internal control (^aP < 0.05, ^eP < 0.001); D: The inverse correlation of miR-34a and Smad4 expression levels was examined by Spearman correlation analysis (R = -0.283, P = 0.029).