Sten Friberg
Karolinska Institutet, Sweden
Title: Nanomedicine: Will it be able to overcome multidrug resistance in cancers?
Biography
Biography: Sten Friberg
Abstract
At present, everythirdindividual in the Western world is diagnosedwith a cancer at somepoint in theirlives. In spiteofgreatadvances in oncology in recentdecades, around50%oftheseindividualswilldie from theirdiseases. The greatmajorityofthesedeathsarecaused by cancer cells endowedwithmultipledrugresistance (MDR). These cells are not eliminated by present-daytherapies, and newstrategies for general oncologictreatmentareneeded. The shapeofsuch newtreatments is emerging, and suchtreatmentswilllikely behighlyindividualized, but at the same timehighlycomplex and costly.
Multimodality is mandatory, and the treatment steps will be sequential.
The plausible major steps arelikelyto be:
- Blockingof the genes responsible for MDR.
- Killingof the adult cancer cellsthatareprotecting the malignantstem cells. With the genes blocked in Step 1, the adult cancer cells will be moresusceptibletotoxicdrugs. Thiswillallowsmalleramountsoftherapeuticdrugsto be used, leading tofewertoxicsideeffects.
- The dead adult cancer cells must be removedtoexpose the dormant cancerstem cells. Dormantcancer cellsarebelievedto be unaffected by present-dayoncologictherapies.
- Initiation ofproliferationamong the cancerstem cells whichwillmake themsusceptibletoeducation or killing.
- Killingof the malignantstem cells, or educatingthemtoenter permanent dormancy and thusrenderthemharmless.
For these five steps, the medical profession is already in possession ofmostofthe neededtherapeutic agents. However, someofthese agents aretoxicwhen givenintravenously in humans, andsomeofthemareinactivatedduring the transport in the blood. Nanoparticlesmightoffer a dual benefit by protectingthe patient from the agent, and simultaneouslyprotecting the agent from the patient.
What is lacking is knowledgeof the timeneeded for each step and ofthe potentialsideeffects for each step.
Effectivetargetingmethodscurrentlyexistfor superficialtumors (bothprimary and secondary), but not for deep-seated cancers.
A moredetailed version ofthissummary is found in: ”Nanomedicine: will it offer possibilitiestoovercomemultipledrugresistance in cancer? J NANOBIOTECHNOLOGY (2016); 14: 17.