Seminar: Use of Aptamer Nanotechnology in Targeting Cancer Stem Cells.
2015-12-24
Speaker : Professor Said Ismail
Time :12:00 PM –01:00 PM.
Location :New Research Complex H10 - Biomedical Research Center, Zone 5, Room # D-140, Qatar University.
Topic :
Cancer is described as the new plague of our modern time. It is one of main killers around the world and the number of affected individuals is on the increase in both developed and developing countries. In addition to their severe side effects, most conventional cancer chemotherapeutics fail to eradicate the disease, and the tumors develop drug resistance and eventually relapse. One exciting new theory that attempts to explain such events states that malignancies actually depend on a small population of stem-like cells for tumor initiation and proliferation, where these cells, which are more resistant to treating drugs, form the driving force for cancer maintenance. These cells were therefore given the name cancer "stem cells" (CSCs). As more evidence supports this theory, better identification and targeting of such cells could have major impacts on the ongoing struggle to develop a new generation of "smart" drugs that can specifically target these cells. Several labs around the world are indeed trying to specifically target these CSCs in an attempt to hit the tumor at its heart by designing "smart" delivery vehicles that circulate through the body and then specifically target the CSCs with its cargo of anti-cancer drugs. Our lab has joined these efforts as we have been developing complex drug delivery systems based on the newly emerging Aptamer Nanotechnology.
Aptamers are short nucleic acids, DNA or RNA that can fold into complex three dimensional shapes and structures, and are able to bind different molecules including proteins with high affinity and specificity. Aptamers are selected by a process called Systematic Evolution of Legands by Exponential Enrichment (SELEX). The SELEX process starts with a massive library of DNA/RNA short oligonucleotides containing up to 1015 different sequences synthesized by combinatorial chemistry.
In this talk we will review a variety of the newly developed smart anticancer drugs as well as present our recent work where we've successfully managed to develop aptamer-based drug delivery systems capable of identifying the CD44, which is one of the main CSC cell surface markers. We will also present our work on other CSC markers including EpCAM and CD133.
We will also shed light on the potential future perspectives of aptamer technology specifically with regards to the combinatorial chemistry involved in the synthesis of Aptamers libraries plus emphasizing the importance of developing sophisticated algorithms to predict the 3D structures of the aptamers as well as in-silico computer screening of aptamer-target interactions.