The experiment hopes to find the correct doses of 5-Azacytidine that has the most therapeutic and least toxic effects. Above is a frequency distribution of the maximum dosage of 5-Azacytidine tolerated. The data in the experiment indicate that 5-Azacytidine is an active drug for the treatment of acute leukemia in children. (1)

The experiment shows that the most commonly known mechanism of 5-Azacytidine and several of its analogues of replacing cytosine in DNA is not the only way they inhibit the capacity of DNMTs to methylate DNA . Several observations led to this conclusion. First, DNMT activity decreases much faster than its incorporation into DNA. Second, among the three DNMTs, only DNMT1 is rapidly and selectively degraded in mammalian cells in response to DNA methyltransferase inhibitors, such as 5-aza-C, as show in the figures above which compare the Western blot analysis of protein concentration from both mouse and HeLa cells. And third, unlike bacterial methyltransferase, mutation of cysteine at the catalytic site, which participates in covalent bond formation, exerts only a minimal effect on mammalian DNA methyltransferase activity. (2)

Epigenetic Cancer Treatment with the example of 5-Azacyitidine Sara Blaza and Kyla Fearon, Northeastern University, Boston MA

Results & Discussion Introduction

Literature Cited

Conclusion Methods

Abstract

It has been established that there is no “one” cure for cancer, rather successful treatment can come from the combination of specific drug doses tailored to an individual’s genome. The newest strategy in treatment is using drugs that work epigenetically – for example 5-Azacytidine and its analogues (a compound that is structurally similar). One study establishes 5-Azacytidine as a drug that can treat myelogenous and lymphocytic leukemia in children. A second study published more recently discusses how 5-Azacytidine and its analogues work. This study goes into more depth of the possible ways 5-Azacytidine reactivates tumor suppressor genes by preventing methylation (epigenetically switching off) of the genes.

1.  Myron Karon, Lance Sieger, Suzanne Leimbrock, et al. (1973). “5-Azacytidine: A New Active Agent for the Treatment of Acute Leukemia.” Blood 42: 359-65.

2.  Kalpana Ghoshal, Jharna Datta, Sarmila Majumder, et al. (2005). “5-Aza-Deoxycytidine Induces Selective Degradation of DNA Methyltransferase 1... and Nuclear Localization Signal” Mol. Cell. Biol. 2005, 25(11):4727.

Cancer is the abnormal growth of cells due to amplified cell division. In normal healthy cells proto-oncogenes and tumor suppressor genes work in harmony to ensure cell division is regulated. Proto-oncogenes are genes that help regulate and promote cell growth and differentiation. Tumor suppressor genes inhibit cell growth and control cell death, apoptosis. A mutation in these genes can cause cancer due to the lack of cell growth inhibition or amplified cell division. 5-Azacytidine was known to stop the proliferation of cancer cells. The big question was how did 5-Azacytidine stop cancer cells from multiplying? It was thought that it used amino acids to make proteins that stop cancer from propagating. Research conducted later on suggested that 5-Aza-c operated epigenetically.

•  The experiment by Myron Karon did a clinical trial on thirty-seven children with acute leukemia in Czechoslovakia. Over the period of trial, the children were given increasing doses of 5-azacycytidine diluted with water to show the effects of 5-aza-c on cancer cells. Prior to the start of the study the children were given a physical examination, a complete blood count, a bone marrow examination, platelet count, uric acid, SGOT, alkaline phosphatase, BUN, and urinalysis. Complete blood counts were done weekly and a bone marrow aspiration was done every twenty-eight days.

•  In the experiment conducted by Kalpana Ghoshal cloned mice DMNt cDNA was amplified and analyzed using PCR. Mice DMNT cDNa was mutated and grown in cell cultures. The cell cultures were then treated with various inhibitors and were then analyzed using Western blot technique and RNA inference assay. The samples were then analyzed using polymerase chain reaction (PCR.)

In conclusion, epigenetic means of treating cancer, such as with drugs like 5-Azacytidine, is the newest product on the frontline of cancer treatment. There is still much to be explored in this area – new drugs to be discovered and additional research on the exact mechanisms of existing ones. Theses experiments provide an impetus to explore new epigenetic cancer drugs, and specifically other cytidine analogs that are capable of inducing proteasomal degradation of DNMT1 at a much lower concentration and that therefore may exhibit significantly greater efficacy in the epigenetic therapy of cancer. Though cancer treatments are being researched worldwide, 5-Azacytidine only inhibits the proliferation of caner cells. Scientists are also researching new drugs that target the cancer cells specifically instead of killing all the cells that are nearby and that are not necessarily harmful. The newest cancer treatments are sure to be revolutionary and life-changing.