The present invention is directed to the field of cancer therapy, specifically solid tumors, by employing a biological drug.
The drug comprises a DNA plasmid carrying the native minimal miR-21 promoter upstream to a killing gene (i.e. DTA).
miR-21 was strongly elevated in colon, lung, pancreas, breast, prostate, stomach, Hepatocellular carcinoma, gastric cancer, ovarian cancer, cervial carcinoma, multiple head and neck cancer, leukemic cancers, papillary thyroid carcinoma and some other solid tumors.
In normal cells, miR21 promoter will be left “locked” permitting cells to escape from the killing effect of the drug.
The invention is based on a selective sensor the endogenous levels of miR21
In malignant cells, miR21 promoter is being active through the endogenous machinery which promotes elevated levels of miR21, down stream killing gene (e.g. DTA) becomes active and blocks de-novo translation.