The present invention provides a method of obtaining miRNA biomarkers by data-search of up-regulated microRNAs (miRNAs) in cancer and screening the miRNA biomarkers to identify cancer kind- and stage-specific miRNA biomarker(s) using cancer cells, tissues and biological fluids. This invention includes obtaining lung cancer-specific miRNA biomarkers including early (Stage I) lung cancer miRNA biomarkers and identification of anti-cancer miRNA (complementary miRNA, DNA and their derivatives) in order to ameliorate diseases. This invention relates to novel utility of nanowell electrodes to detect target molecules in biological samples. The invention teaches methods to increase sensitivity of nanowell electrodes to detect target molecules including miRNA, RNA and DNA in biological samples to diagnose cancer and other diseases and monitoring prognosis and response to therapy. This invention includes methods to study loss of function of miR486, miR29c or miR122 in lung cancer cells, animal models and patients and find therapeutic anti-miRNA(s).
