What Does Translationally Controlled Tumor Protein (Tctp) Promise? Is Tumor Reversion Possible?
Cancer research mainly interests understanding how a normal cell becomes malignant. Here is another question: How does a tumor cell quit the
malignant state and return? The answer may be that the reprogramming of tumor cells. In the process of tumor reversion, expressions profiles
of many gene can provide reprogramming of tumor cells to the revertants.Recent studies suggested that most strongly downregulated protein in the revertant cells is TCTP. Essentially, TCTP is a house-keeping gene expressed in some cells including not only tumor cells but also erythrocytes, and encodes for a hydrophilic protein of 18–23 kDa. TCTP transcripts accumulate in the resting cells and the cells are rapidly translated, if necessary, into the protein. TCTP protein is expressed at low levels in resting cells and high levels in proliferating cells.Overexpression of TCTP leads to inhibition of etoposide-induced apoptosis, thus reducing TCTP expression either results in apoptosis or reprogramming of cancer cells to the revertants. Additionally, pharmacological studies have shown that agents that reduce TCTP levels kill tumor cells. Other suggested molecular mechanisms in relation to tumor reversion of TCTP are: TCTP is a tubulin-binding protein that
associates with microtubules in a cell-cycle; TCTP is directly interact with PLK1 and required for the normal progression of cytokinesis;TCTP binds to the MCL1 protein involved in the programmed cell death; and shows structural similarity to channel-forming helices of the pro-apoptotic protein Bax.In conclusion, TCTP is a key player in the process of tumor reversion and also may provide the new strategies in cancer treatment by identification of new pharmaceutical compounds able to reduce its expression and kill malignant cells.