Tea catechins as cancer specific proliferation inhibitors

DETAILED DESCRIPTION The invention described herein encompasses a method of treating cancer or solid tumors comprising the administration of a therapeutically effective amount of catechins, a group of polyphenols found in green tea, to a mammal in need of such therapy.
In a preferred embodiment, the mammal is a human.
In another embodiment, the invention further encompasses the use of combination therapy to treat cancer.
In a specific embodiment, the catechins comprise epigallocatechin gallate (EGCg), epicatechin gallate (ECG), epigallocatechin (EGC), and epicatechin (EC) or a combination thereof, optionally in combination with other polyphenols or other anti-cancer therapeutic agents.
The disclosure is based, in part, on the discovery that epigallocatechin gallate (EGCg), alone and in combination with other catechins and other anti-cancer therapeutic agents, inhibits the activity of a cancer-specific protein, an isoform of NADH oxidase specific to cancer cells (tNOX).
The inhibition of tNOX results in the inhibition of cell growth, and ultimately, apoptosis of the cancer cell, whereas normal cells (which lack tNOX but instead express the isoform CNOX) are less affected.
Thus, the invention provides a potent therapeutic effect without or while reducing the adverse effects on normal, healthy cells.
The invention is also based, in part, on the discovery that the effect of EGCg is reversible, i.
e.
, if the EGCg is removed, cancer cells resume normal rates of growth.
Other discoveries include: (1) EGCg is rapidly cleared from the blood and metabolized, (2) cancer cells must be inhibited from growing for 48 to 72 hours before EGCg-induced apoptosis occurs, and (3) when cancer cells are challenged with 10.
sup.
-7 M EGCg every two hours during the day, their growth is inhibited, but during the night normal cell growth resumes in the absence of further EGCg addition.
Thus, the invention includes a unique feature of administration comprising a sustained release formulation so a constant level of EGCg is maintained