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Matthew Dunning 7-May-14 Prostrate Cancer

Prostate Cancer Solutions Via Drug Delivery System Abstract: Drug delivery systems have progressed over time and have offered new opportunities to discover cures to diseases. Prostate cancer is one the diseases that affect a various amount of people. However, a designed drug delivery system could be designed to save people’s lives. The design of this paper is to explain more detail about prostate cancer and a possible cure to the cancer. Introduction: The problem being researched in this paper is Prostate Cancer. The cancer affects the prostate (it is below the bladder). The disease occurs first begins when cell division and cell death are not equal, causing a build up of the tumor1. Once after this occurs, the genes p53, retintoblastoma will lead to further progression of the tumor1. The other definitive cause of the cancer in the prostate comes from cell morphology that comes from the urothelial lining of the urethra1. The main symptoms of the disease are urinary retention, back pain and hematuria (blood in urine) 1. People with prostate cancer may have a loss of appetite, over-distended bladder, adenopathy, bony tenderness and venous thrombosis (blood clot in a vein) 1. Prostate cancer is very serious; the death rate is about 23 per 100,000 men 2. An estimated 1 in 6 men, (1 in 5 for African Americans) are diagnosed each year1. About 80% of men (age of 80) have prostate cancer; the greatest risk comes among white men over the age of 50, and black men after the age of 403. About 66% of the cancer is diagnosed in men of the age 65 and older3. The risk of getting Prostate Cancer increases from 8% to 25% when the level of PSA rises from 1 ng/mL to 4-10ng/mL1. From data collected in 2004, prostate cancer had a major economic impact4. Prostate cancer accounted for nearly half a million hospital stays and total treatment for the stays added up to be 657 million4. The average cost for prostate cancer hospitalization was $8,100 in 20044. Figure 1: Image of Prostate Cancer in different stages

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Experimental and Materials: For my drug delivery system, the material used to deliver the SiRNA would be SNLAP. For the characterization of my system, the diameter of the SNALP would be 120nm, it needs to be big enough in order to hold the SiRNA (it is a large molecule). SNALP must be positive/hydrophobic so that the cancer cells will be attracted to it and so water will not interfere with it. To test the efficacy and toxicity of my DDS, a series of in-vivo experiments would be conducted. Experiment 1: Mice were given 0.3 micro grams of HBV, which resulted in replication of the HBV vector within the liver and titers in the serum5. After the injection, the mice were given six days to rest before the SiRNA-SNALP was administered5. The mice were treated with HBV263-M-SNALP, HBV263invM-SNALP, HBV263-SNALP or HBV263invr-SNALP at 0.3 or 3mg/kg/day for 3 consecutive days. 5 Then the mice were killed either 3, 7, or 14 days after treatment5. The toxicity was then measured by monitoring the serum transaminase5. The final results showed that SNALP with stabilized SiRNA is an efficient method; it managed to reduce HBV DNA in vivo5. The SNALP had a longer half-life in the liver and managed to reduce the toxic and immunostimulatory effects. 5 Experiment 2: Another experiment performed in vivo was by the use of SiRNA inside of a CCLA (cardiolipin analogue) in mice6. The CCLA liposomes were administered via the tail vein at 7.5mg/kg twice a day for 5 days to mice bearing a breast cancer tumor6. The results for this experiment showed that the tumors treated with liposomal-SiRNA were 73% smaller, showing the vehicle had a therapeutic effect and managed to lower the toxic effects6. Results: Cancer in general has been around for quite some time; more specifically prostate cancer has been around since 1966, which means there hasn’t been a 100% cure discovered yet for 50 years. My drive for my DDS is in hopes that it will reduce/rid of the cancer in the prostate. The fact that every 1 in 6 men are still getting affected is exactly why I’m motivated to find a cure. The physical and chemical aspects of my DDS are very important. The SNALP must be covered in PEG that way the complement system is not activated. A formation of the circle of particles (the Stable nucleic acid-lipid particles) will allow the system to maintain a good bio- distribution, which will allow it to avoid filtration from the kidney. My DDS also has siRNA and docetaxel encapsulated within the SNALP. Docetaxel is a drug that interferes with the cancer cell’s microtubules, it’s a chemotherapeutic drug used to treat prostate cancer7. Finally, there are targeting moieties on the surface that are composed of N-2-Hydroxypropyl methacrylamide (HPMA); HPMA polymers are water-soluble 8.The chemical components are images defined as followed: Figure 1: Chemical structure of siRNA image of chemical structure of small interfering RNA.

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Figure 2: Chemical Structure of PEG Figure 3: Chemical Structure of Cationic Lipid (Part of SNALP) Figure 4: Chemical Structure of N-2-hydroxypropyl methacrylamide (left) and docetaxel (right)

My drug delivery system will address the following problem of prostate cancer. Being coated with PEG and N-2-hydroxypropyl methacrylamide coated moiety, the SNALP will have no issue locating its target and being detected by the compliment system. Since the cancer cell is negative and SNALP is positive, siRNA will leave SNALP and enter through the cell where it will bind with the protein called argonaute within RISC (RNA-induced silencing complex)9. The SiRNA then will begin to unwind eventually to the point where the SiRNA strands eventually become separated9. The RISC becomes activated and targets the AR (Androgen Receptor) mRNA9. Once this occurs, the AR-mRNA will bind to RISC and the cleaving begins. The AR gene is then

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silenced and the excess remains of the gene are flushed out of the cell9. Also having docetaxel within my drug delivery system will affect another apart of the cancer cell. Docetaxel will enter the cancer cell and interfere with the microtubules, which will lead to both cell death and preventing the cancer cells from dividing7. Figure 5: SiRNA gene silencing

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Figure 6: DDS Since then the AR genes are being silenced, the mRNA in the prostate cannot process more Prostate-Specific Antigen. Since in most deaths of humans the PSA is abundant, it infers that Prostate Cancer must use the protein to continue/develop its growth1. Since the AR gene is being silenced, PSA cannot be produced which overtime will cause the cancer to die. My drug delivery system would be delivered intravenously because it is the fastest way to deliver my DDS to the prostate. Discussion: As mentioned earlier before in my paper, the characterization of the drug delivery system would be a SNALP carrier that is hydrophobic that is 120nm in diameter. As done in the previous in vivo experiments mentioned, the use of siRNA proved to create intended results along with keep the toxicity levels low. The limitations of my DDS are that having a chemotherapeutic drug and siRNA within a carrier has not been tested yet, therefore the results (data) and side effects are unknown. The other limitation that is not known is if the docetaxel fails to interfere with the microtubules, will it have any effect on the siRNA trying to silence the AR-mRNA. The opportunities of the DDS are very great, as the use of my DDS will not exclude certain age groups from using it and it provides two ways in order to help reduce the tumor size. The advantage of using an intravenous route of administration, will allow the drug/siRNA to be delivered over a constant period of time which will prevent the over expression of PSA during that time. I did not manage to find clinical trials that had all three (SNALP, docetaxel and siRNA) but I did manage to find trials that had some aspects of my DDS.

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Trial 1: One trial that I found for siRNA, siRNA was specified for the expressed gene CD31 and was complexed to cationic liposomes10. Intravenous administration of the anti-CD31 siRNA was given (2.2 mg/kg) to mice with prostate cancer; the observations were that the dose of 0.1 mg/mouse decreased the tumor size10. Trial 2: The other clinical trial that is in place is the study of docetaxel-loaded polyethylene glycol on hormone-refractory prostate cancer11. The system had an average particle size of 25.19nm and the trials were done in vivo11. The results of the in vivo trials concluded that the docetaxel reduced the level of PSA dramatically and the tumor growth in mice11. Conclusion The findings of my research paper were first made of nanoparticles that could be used to fight prostate cancer, which includes the findings of siRNA, docetaxel/prednisone and the targeting moiety of N-2-hydroxypropyl methacrylamide. I was able to research via use of clinical trials the effectiveness that both the siRNA/docetaxel was able to produce, which was lower PSA levels and decrease tumor growth in prostate cancer. In the designed level, it offers a “killing two birds with one stone” where both the siRNA and docetaxel will diminish prostate cancer; it is a large contribution because how there has not been a 100% effective way to cure prostate cancer. On the translational level, it is a huge contribution in the field of drug delivery because there are still people who do not fully understand the genetic makeup of prostate cancer; the siRNA will silence the AR gene causing a decrease in the amount of PSA being transcribed. My DDS can be alternative treatment for prostate cancer, because now instead of having to get surgery for treatment, there will be option of using my DDS. Right now the costs for prostate cancer treatment are dependent upon the treatment, watchful waiting ($4270), hormonal therapy plus radation ($17,474), and surgery ($15,197) 12. The cost-effectiveness of my DDS will cost more than watchful waiting but will cost less than having therapy or surgery done. From my research, future direction can be derived because of this new cost-effective DDS that offers a “two for one” kill of prostate cancer, researchers can use my design to create and test to see the specific toxicity and efficacy and make changes to the design to better further the results.

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References: 1) http://emedicine.medscape.com/article/1967731-overview 2) http://seer.cancer.gov/statfacts/html/prost.html 3) http://www.webmd.com/prostate-cancer/guide/prostate-cancer-risk-factors 4) http://www.hcup-us.ahrq.gov/reports/statbriefs/sb30.pdf 5) http://www.nature.com/nbt/journal/v23/n8/full/nbt1122.html 6) http://www.nature.com/mt/journal/v13/n4/full/mt200681a.html 7) http://www.cancer.org/cancer/prostatecancer/detailedguide/prostate-cancer-treating-chemotherapy 8) http://mct.aacrjournals.org/content/6/11/2928.abstract 9) http://www.invivogen.com/review-rna-interference 10) http://www.snupharm.ac.kr/ohyk/erp/erpmenus/professor_thesis/uploadfiles/oyk_review.pdf 11) http://www.ncbi.nlm.nih.gov/pubmed/24496681 12) http://pressroom.cancer.org/index.php?s=43&item=264