The cancer that was initially thought to be rare
In 1853, in his report of a patient’s condition, John Adams, a surgeon at the London Hospital, wrote thus: “It is a very rare disease.” Adams was the first to discover prostate cancer by carrying out a tissue examination on the patient. Prostate cancer is the second most common cancer among men in the world. According to the Cancer Research Center at Tehran University of Medical Sciences, prostate cancer is the third most deadly cancer in Iran, preceded by gastric cancer and lung cancer. Can the growth of cancer be halted in prostate cancer?
MSTF media reports:
The prostate is a chestnut-sized gland in the male reproduction system. The etymology of the word ‘prostate’ can be traced back to a Greek expression meaning ‘one who stands before.’ It describes the position of the prostate gland; it is located under the bladder but a viewpoint from the below shows that the prostate ‘stands before’ the bladder. The male hormone, testosterone, which is produced in the testicles, turns into its bioactive compound, Dihydrotestosterone, in the prostate. The discharges from this gland play a role in protecting the sperm and correspondingly male fertility.
The prostate consists of three parts. The innermost and smallest part is the transition zone which the urinary tract partially passes. Semen enters the central zone of the prostate through a tube, mixing with discharges from the prostate. The outermost part of the prostate constitutes 70 percent of its mass.
It was not until the early 1900s that prostate cancer was distinguished from other types of urinal obstructions. With old age, the tissue of the transition zone (the innermost part) undergoes a growth which is benign and noncancerous. The growth leads to pressure on the bladder and the urinary tract, ultimately causing urination problems. Malignant cancerous tumors, however, mostly form in the outermost part. The symptoms of prostate cancer include decreased urine stream, frequent urination especially at night, pain or burning during urination and blood in the urine or the semen.
Targeted Chestnut Cracking
Targeted treatment of cancer using nanotechnology equipment started in 1964. This class of treatment methods involves entering the packaged drug, consisting of nanoparticles, into the body. Other than increasing drug circulation in the blood and protecting it against undesired damage or absorption by cells other than targeted cells, this method aims at reducing toxicity. Selecting the nanoparticles, arranging the structure of the drug carrier and determining how it will bind to the targeted cells are among the most important stages of planning a targeted path for drug delivery.
The first research report related to targeted drug delivery using nanoparticle-Aptamer was published by Omid Farokhzad and his research team in 2004. Aptamer is a short, single-stranded synthetically-crafted molecule made of DNA or RNA, which has a particular 3D structure leading to a high-affinity binding to the specialized receptors. Therefore, Aptamers can be used to recognize and connect to specialized receptors of cancerous cells in order to carry out a targeted drug delivery.
The attachment of Aptamer to the receptor resembles that of the antibody to the cell receptors. Antibodies are protein structures which can pair with special receptors on the surface of the cell to affect the cell. Having a nucleic acid nature, Aptamer has the same function and compared to antibodies has such advantages as shorter production time, lower production costs, greater modifiability, better thermal stability, and better targeting.
How Omid Targeted the Cancerous Chestnut
In the project carried out by Omid Farokhzad, the use of the nanoparticle-Aptamer combination to treat prostate cancer was studied. Initially, Farokhzad and his team designed a layer of nanoparticles to encircle the drug. This nanoparticle covering is made up of two biocompatible and biodegradable polymers which were approved by the U.S. Food and Drug Administration for clinical trials. The role of these polymers was to increase the half-life of the drug's circulation in the blood and reduce absorption in non-target cells.
The research team, then, designed an RNA-made Aptamer capable of pairing with the special receptor of prostate cells, receptors whose numbers and presence in prostate cancerous cells are very high. The study conducted by Farokhzad and his team indicated that the nanoparticle-Aptamer biocompound can efficiently target the cells and be absorbed by them. Also, the absorption of this drug compound by cells bereft of the special receptors of prostate cells did not increase. The team believes that by optimizing the design of drug carriers that have nanoparticle-aptamer structure, this method can be used for targeted drug delivery and treatment of many important human diseases.
