The hormone-like structure, 3-Iodothyronamine (T1AM), is a structural analog of a thyroid hormone and has been showing recent effects on many physiological systems. Of these effects, most recently discovered is its ability to treat obesity and cause prolonged weight loss. Though these recent discoveries involving T1AM’s ability to create metabolic effects have been most telling, the specific mechanisms involved are unknown. This mystery has created a curiosity of not only how T1AM’s mechanisms work but how they affect different ranges of metabolic abilities. This includes cancer cells and their unique metabolism and ability to repress apoptosis. Using the past knowledge done by this lab on T1AM, they were able to hypothesize that T1AM may disrupt growth and rapid reproduction of cancer cells. They also put forth the goal to evaluate the cytotoxicity of the compound in normal cells since its toxicity had yet to be evaluated outside of a living organism and in low animal numbers. Not only was T1AM examined in this experiment, but researchers also sought to examine the abilities and potency of synthetic T1AM, SG-2, compared to the original compound. Overall, researchers evaluated the effects T1AM and SG-2 on cancer cells and cytotoxicity of each molecule on normal cells to determine their future potential as cancer therapy. To do so, they studied the impact of T1AM and SG-2 on cancer cell growth rate in vitro, their uptake patterns, and gene transcription changes. To do this, the toxicity of T1AM and SG-2 was assessed in multiple types of cells including MCF7 human breast adenocarcinoma cells, HepG2 hepatocellular carcinoma cells, human foreskin fibroblast (HFF) normal HFF, and 3T3-L1 normal mouse preadipocyte fibroblasts. This was done to evaluate their anticancer properties and cytotoxicity in normal cells. All cell types were chosen based on their different characteristics as cancerous or “normal” cells including those with different yet “normal” characteristics and tissue origins. Cell viability was measured by MTT of cells treated with different combinations of SG-2 or T1AM with a vehicle, or untreated. Data provided by MTT designated the IC50value. Statistics providing evidence of differences in the viability of T1AM or SG-2 treatment concentrations were determined using one-way ANOVA. Further tests including Dunnette’s post hoc were used to compare differences in cell viability from control subjects instead of those between treatment dosages. Cell recovery growth was monitored by overseeing 7 days of incubation with or without treated media and continued even 7 days post-treatment. Fluorescently labeled T1AM was developed and imaged over real-time being taken up by cells. This made it possible to assess uptake and cellular localization of the labeled T1AM using confocal microscopy. Emission signal in cells was measured and repeatedly assessed to assess the further shift in signal detection. This was done on MCF7 cells which were pretreated with control growth media and media supplemented with SG-2 to oversee the impact of SG-2 on T1AM uptake. (RT)-PCR was done to identify gene pathways affected by SG-2 in cancer cells. Further gene expression studies were done with H-NMR metabolic to finalize testing. Results showed that after an incubation of 72h, MCF7 cells showed significant cancer cell growth and viability reduction in both compounds. The IC50value of T1AM and SG-2 differed throughout different cell types showing the effects across a variety of cancer cells as well as the differences between cell lineages and growth rates of cell lines and potency of the compounds. Charts of cell viability of MCF7 cells and the fact that the IC50 of T1AM was approximately double the concentration of its analog SG-2 in cancer cells showed that SG-2 appeared to be twice as potent at inhibiting cancer cell growth than T1AM. Photographs taken after the 72h incubation period showed irregularity rounded cells showing cell stress and/or death of those cells within higher SG-2 concentrated media. Even more changes in the viability of different cell types showed that SG-2 is even less cytotoxic in normal cells. Results of recovery protocol of cells affected with SG-2 even after removal showed lasting suppression of SG-2 on cell growth and viability. This differs from many drug therapies whose effects do not continue after use but also come with side effects prohibiting their use as a long-term treatment plan. Though the mechanism of T1AM cellular uptake and target have been unknown throughout many years of research, researchers using this experiment received results confirming T1AM to be taken up by the cells. They observed rapid uptake supporting the previous idea that T1AM moves intracellularly through facilitated diffusion mechanisms. Results from the impact SG-2 treatment on T1am uptake analyzed using FACS were confirmed to also showed T1AM and SG-2 to have relatively identical uptake mechanisms suggesting similar saturated uptake rate mechanisms of both molecules. Significant reduction in cell viability was the results of incubation of MCF7 cells in T1AM and SG-2 over a 72h period. SG-2 was very effective in reducing HepG2 cell viability showing its ability on a dramatically different cancer cell line by tissue origin lineage. The same molecule, SG-2 was also shown to be far less toxic in similar doses in normal cells than cancer cells. The sensitivity of treatment by T1AM and SG-2 appears to be affected by cell lineage-specific responses. Overall, results showed that over time, growth rates of cancer cells were reduced continuously and that cell population doubling time was much slower during that same period compared to untreated controls. Though all information proves to be vital in past and future T1AM research, one of the most important observations resulted in the evidence of the mitochondria being one of the primary targets of T1AM. In all, data has shown that due to their effectiveness, both T1AM and SG-2 have strong anticancer treatment potential. This research showed ample evidence of the future of T1AM and SG-2 research and the possibility of in vivo cancer study.