If your veterinarian has any inquiries about rapamycin and its possible advantages for your pet, we are always delighted to collaborate with them.
Our recommended rapamycin dosage for dogs is 1 mg administered three times per week with food for every 20–22 lbs of your dog’s weight. Therefore, 12 capsules will benefit your pet for a full month. We have administered this dose safely to well over 300 animals.
Is canine rapamycin safe?
Recently, we conducted a randomized double-blind veterinary clinical trial to evaluate the benefits of rapamycin medication given to healthy, middle-aged companion dogs for a period of 10 weeks, as well as its dose and safety. Here, we present the findings of this study. It was discovered that rapamycin treatment for 10 weeks at 0.05 or 0.1 mg/kg administered orally three times a week did not result in clinically significant side effects or abnormal hematological changes, but it did produce positive changes in cardiac left ventricular function during both diastole and systole.
Which dogs are eligible for the dog Aging project’s intervention trial?
A group of digital entrepreneurs has pledged $2.5 million to The Dog Aging Project, a scientific project to assist companion dogs and people live longer, healthier lives together.
The Dog Aging Project is the world’s largest canine health study, bringing together a community of dogs, owners, veterinarians, researchers, and volunteers. The donation will help this study of longevity science progress.
The donors are Dr. Peter Attia, Juan Benet, CEO of Protocol Labs, Fred Erhsam, co-founder of Paradigm and Coinbase, Adam Fisher of Bessemer Venture Partners, author Tim Ferriss, the Saisei Foundation, Jed McCaleb, co-founder and CTO of Stellar, founder of the Astera Institute, food author Darya Rose, and internet entrepreneur Kevin Rose. They also include Brian Armstrong, founder and CEO of Coinbase.
The two main objectives of the Dog Aging Project are to extend healthspan—the amount of time spent living without illness—and to comprehend how genes, environment, and lifestyle affect aging. The Dog Aging Project’s findings might also apply to people.
The Dog Aging Project already includes more than 32,000 companion dogs and their owners. Every dog resides with and interacts with their families at home. The majority of these canines take part in the Longitudinal Study of Aging, an observational study. Through a safe research portal, each dog owner completes thorough questions regarding the condition and quality of life of their pet. To gain understanding about aging, this information is combined with extensive environmental, genetic, and biochemical data.
Furthermore, the Dog Aging Project is running a double-blind, placebo-controlled, veterinary clinical trial of the drug rapamycin, which has been demonstrated to lengthen longevity in laboratory animals when administered at low dosages. Test of Rapamycin in Aging Dogs is the acronym for the trial, which is known as TRIAD.
The consortium of contributors’ $2.5 million in new funds will be used only for scientific study. With this assistance, the Dog Aging Project will be able to increase the number of participating dogs and study sites for the TRIAD Trial.
Dr. Matt Kaeberlein, co-director of the Dog Aging Project, stated that “targeting biological aging is 21st century medicine, with the potential to dramatically enhance healthy longevity for both ourselves and our pets.” “The first clinical assessment of an intervention that might lengthen lifespan and improve healthspan will be provided by TRIAD. This kind gift will significantly speed up our research and move us closer to our objective.” At the University of Washington School of Medicine, Kaeberlein teaches pathology and laboratory medicine.
More than 70 researchers and veterinarians from more than 20 academic institutions around the nation are a part of the research team, which is headed by academics from Texas A&M University and the University of Washington. This scientific endeavor is public. Through Terra, a cloud computing platform run by the Broad Institute of MIT and Harvard, the information gathered by the Dog Aging Project will be made accessible to academics all around the world. Additionally, biological samples will be stored at the Cornell University Veterinary Biobank, which is home to the Dog Aging Project Biobank.
Introduction
After skin cancer, breast cancer is the second most frequent malignancy among American women. 227,000 new cases have been documented so far in 2012 [1]. The early identification of breast cancer, when treatment is most successful, has improved because to recent advances in computed tomography imaging [2]. The rapid advancement of technology has resulted in an explosion of study on the molecular causes of breast cancer. As a result, tactics for therapeutic advancements are increasingly using mechanism-based approaches. Although breast cancer death rates are still greater than those of all other types of cancer except lung cancer, recent years have seen a drop in breast cancer fatalities as a result of technical advancements in early diagnosis and superior therapies [3].
This article tells a story of discovery that confirms the accidental character of fundamental research and the idea that discoveries could have unexpected effects in other fields. In one case, three decades ago on a distant island, a bacteria called Streptomyces hygroscopicus was isolated from a soil sample. This discovery sparked extensive, diverse study that revolutionized the way breast cancer is treated. The discovery of rapamycin from Streptomyces hygroscopicus as an efficient anticancer medication, an immunological inhibitor, and an antifungal agent illustrates a research continuity driven by clinical observations that were essential in the understanding of the mTOR circuit. Research on the intricate and crucial mTOR pathway, which transmits signals via which it regulates a variety of essential biological processes, was stimulated by rapamycin. Understanding of the transcription, protein synthesis, and metabolic processes that support neoplastic transformation has improved thanks to the dissection of the molecular networks of interconnected signaling pathways. Such information sparked therapeutic advancements that produced breast cancer patients with targeted medications. Endocrine medications are available for patients who are estrogen and/or progesterone receptor positive and work by obstructing the signaling network that controls cell division and growth. Tamoxifen and aromatase inhibitors, which prevent the generation of estrogen and the binding of estrogen to the receptor, respectively, are two examples of targeted therapeutics. Trastuzumab and lapatinib are examples of HER2 antibody-targeted treatments that may be used to treat patients who are HER-2 positive [4].
From the chemical and pharmacologic characterization of rapamycin to the molecular mechanisms of breast cancer, ending with clinical applications and treatments, this review will concentrate on the mammalian Target of Rapamycin (mTOR) pathway. It will also offer a perspective on translational research.
Discovery of rapamycin
A natural substance called rapamycin, sometimes referred to by its scientific name Sirolimus, was discovered on the island of Rapa Nui in 1972 [5]. It was obtained from the fungus Streptomyces hygroscopicus. Its structural analyses revealed that it resembles the antibacterial macrolide lactone FK506 [6]. Rapamycin has been shown in studies to have a variety of qualities, including antibacterial, antifungal (anti-Candida), and immunosuppressive actions. It prevents T cell and B cell growth and antibody production brought on by antigens. Since rapamycin was created as an immunosuppressant medication for patients after organ transplantation, the latter discovery has important clinical ramifications. The FDA in the United States gave its approval for use as a preventative measure against kidney rejection. In order to avoid kidney rejection, Rapamune was promoted by Wyeth Pharmaceuticals as an immunosuppressant to be used in concert with corticosteroids and cyclosporine [7].
Without Dr. Suren Sehgal’s study at Ayerst Research Laboratories in Montreal, where rapamycin was discovered to be an immunosuppressant, it may not have been possible to investigate rapamycin’s potential as a workable tumor suppressor. Rapamycin was isolated from its natural environment there in 1972. One would have assumed logically that an immunosuppressive substance would hinder an immune response against tumor cells and would thus be unlikely to be an effective anticancer therapy. However, Dr. Sehgal noted that this substance appeared to have unique qualities in addition to its immunosuppressive effects [8]. He requested anti-tumor activity screening and sent a sample of rapamycin to the National Cancer Institute (NCI) Developmental Therapeutics Program. NCI originally examined substances for growth inhibition against a small selection of human tumor cell lines as part of a regular screening protocol. If a chemical inhibited the growth of one or more of these cell lines, it would then be evaluated at various concentrations for growth inhibition or killing of one or more of the NCI standard 60 human tumor cell lines. Only 2% of the 2500 substances evaluated each year move on to the in vivo tests in xenographs in mice. Rapamycin was discovered to decrease the growth of a number of tumor cell lines against the 60 tumor cell line panel, including mammary, colon 26, B16 43 melanocarcinma, and EM ependymoblastoma [9]. These test results led NCI to designate rapamycin as a priority medication.
Mammalian Target of Rapamycin (mTOR)
Numerous studies have confirmed rapamycin’s inhibitory effect on cell growth in a variety of organisms, including Saccharomyces cerevisiae [12], Drosophila [13,14], Caenorhabditis elegans [15], fungi [16], plants [17], and mammals [18], following the NCI’s discovery of the drug’s anti-tumor activities. The inhibition mechanism in these organisms requires binding to the target proteins, also known as TOR (Target of Rapamycin) [12]. With different organisms, the specifics of the inhibitory processes vary. These proteins are, nonetheless, consistently observed to be very evolutionary conserved [19]. The homology between the TOR protein sequences from eukaryotes ranges from 40% to 60%, and several structural motifs are conserved [20]. The main sequence of the human TOR protein shared 95% identity with other mammalian TORs (mTOR), which is even higher [21].
According to biochemical research, mTOR produces the mTORC1 and mTORC2 complexes [22]. The proteins mTOR, Raptor (mTOR’s regulatory-associated protein), mLST8/GL (mammalian lethal with Sec13protein8/G-protein -subunit-like protein), PRAS40 (a proline-rich AKT substrate of 40 kDa), and DEPTOR (a DEP-domain-containing mTOR-interacting protein) make up the mTORC1 complex [23]. The catalytic kinase complex is called mTORC1. There are several conserved motifs in the mTORC1 component proteins, including those that are necessary for protein-protein interactions. This finding along with the discovery of kinase activity in this complex raises the possibility that this complex functions as the hub for mTOR signaling. Rapamycin does not directly affect the activity of mTORC1 kinase. It first joins forces with the protein that binds FK506 (FKPB12), and FKPB12 then binds mTORC1 [24–27].
Following investigations into the roles of TOR were motivated by the discovery that TOR proteins are conserved throughout a wide range of species, from basic eukaryotes to mammals. Given that these proteins have remained structurally constant throughout evolution, with some minor structural alterations, it is reasonable to assume that TORs may be essential for survival. Thus, it is inferred that TOR functions not only provide evolutionary advantages but are essential for survival. The TOR pathway takes signaling inputs from insulin, growth hormones, and nutrients for its critical function in cell survival. The TOR pathway is essential for controlling cellular energy levels via controlling cell size or mass, proliferation, and response to stressors like nutritional deprivation (glucose or amino acids) [13,14,28,29]. The linked functions of transcription, protein translation, and cell cycle control from G1 to S phase underlie the role of mTOR in cell growth. Given the significance of these biological activities, the involvement of the TOR pathway in numerous disease processes shouldn’t be a surprise. Although it is outside the purview of this report to conduct a thorough analysis of mTOR’s function in disease processes, it is crucial to comprehend the mTOR signaling mechanism because it underlies a number of disease processes and has been used to direct the development and administration of cancer therapeutics.
mTOR signaling pathway and regulatory network
A member of the phosphatidylinositol 3-kinase-related kinase family of serine/threonine kinases, mTOR is controlled by the PI3K and Akt/PKB pathways [30]. Growth factors such as insulin, vascular epithelial growth factor, insulin-like growth factor 1 (IGF-1), and epidermal growth factor bind to cell surface receptors to trigger PI3K/Akt pathway intracellular signaling (Figure 1). The phosphorylation of 4EBP1 and p70S6 Kinase is a downstream result of this activation [31]. Increased mTOR serine 2448 phosphorylation is another downstream consequence. Studies of Akt mutants with kinase activity but no ability to phosphorylate p70S6 kinase or 4EBP1 provided evidence that mTOR signaling is involved in oncogenic transformation. These mutants were unable to change the fibroblast cells in chicken embryos [32]. A complex balancing act of regulatory switches determines which mRNA will be translated as a result of mTOR kinase activity, leading to the mTOR-driven phosphorylation of essential proteins. For instance, enhanced translation from mRNAs that contain the 5-terminal oligopyrimidine tract, such as those for the elongation factor-1, results from mTOR phosphorylation of p70S6 kinase, which in turn causes downstream phosphorylation of the 40S ribosomal protein S6 [33]. These processes work together to promote protein synthesis and ribosome biosynthesis. Conversely, increased translation from mRNAs containing 5-untranslated regions, such as those for cyclin D1 and cmyc, which are essential for cell cycle, results from activation of the 4EBP1 translation initiation factor (Figure 2). These instances demonstrate how mTOR controls protein production by phosphorylating essential proteins.
