Immunohistochemistry showed that the expression of miR-222 in lung cancer tissue was significantly higher, but TIMP3 was lower than that in normal lung tissue (<i>P</i> = 0.0001 for the former and <i>P</i> = 0.0002 for the latter).
In conclusion, our data are the first to show tumor-suppressive effects of miR-221 and miR-222 on lung cancer, warranting testing their potential as therapeutics for the disease.
MiR-30b, miR-30c, miR-221 and miR-222 are known to induce gefitinib resistance in lung cancer cell lines with activation of mutations in the epidermal growth factor receptor (EGFR).