RESUMO
The burden of cancer for Canadian citizens and society is large. New technologies have the potential to increase the use of genetic information in clinical decision-making, furthering prevention, surveillance, and safer, more effective drug therapies for cancer patients. Personalized medicine can have different meanings to different people. The context for personalized medicine in the present paper is genetic testing, which offers the promise of refining treatment decisions for those diagnosed with chronic and life-threatening illnesses. Personalized medicine and genetic characterization of tumours can also give direction to the development of novel drugs. Genetic testing will increasingly become an essential part of clinical decision-making. In Canada, provinces are responsible for health care, and most have unique policies and programs in place to address cancer control. The result is inconsistency in access to and delivery of therapies and other interventions, beyond the differences expected because of demographic factors and clinical education. Inconsistencies arising from differences in resources, policy, and application of evidence-informed personalized cancer medicine exacerbate patient access to appropriate testing and quality care. Geographic variations in cancer incidence and mortality rates in Canada-with the Atlantic provinces and Quebec having higher rates, and British Columbia having the lowest rates-are well documented. Our purpose here is to provide an understanding of current and future applications of personalized medicine in oncology, to highlight the benefits of personalized medicine for patients, and to describe issues and opportunities for improvement in the coordination of personalized medicine in Canada. Efficient and more rapid adoption of personalized medicine in oncology in Canada could help overcome those issues and improve cancer prevention and care. That task might benefit from the creation of a National Genetics Advisory Panel that would review research and provide recommendations on tests for funding or reimbursement, guidelines, service delivery models, laboratory quality assurance, education, and communication. More has to be known about the current state of personalized cancer medicine in Canada, and strategies have to be developed to inform and improve understanding and appropriate coordination and delivery. Our hope is that the perspectives emphasized in this paper will stimulate discussion and further research to create a more informed response.
RESUMO
Melanin concentrating hormone (MCH), a hypothalamic neuropeptide, is an important regulator of energy homeostasis in mammals. Characterization of an MCH specific receptor has been hampered by the lack of a suitable radioligand. The [Phe(13), Tyr(19)]-MCH analog has been shown by different investigators to bind specifically to cell lines of epithelial or pigment cell origin. Recently, using functional assays, the MCH receptor has been characterized as a seven transmembrane G-coupled protein initially identified as SLC-1. In the present study, we used tyrosine iodinated [Phe(13), Tyr(19)]-MCH analog, which stimulates food intake in a manner similar to that of MCH, as well as native MCH to conduct binding studies. Specific binding could not be demonstrated in intact cells of several cell lines, including A431 and B16. Specific binding associated with membranes localized to the microsomal, not the plasma membrane, fraction. Message for SLC-1 was absent in these cell lines, as assessed by Northern blot analysis. We conclude that cells previously reported to express the MCH receptor do not express SLC-1 and that both iodinated MCH and the [Phe(13), Tyr(19)]-MCH have a large component of non-specific binding. These ligands may be useful for binding studies in transfected cells with high levels of SLC-1 expression. However they do not appear to be suitable for screening for the MCH receptor as most cells demonstrate significant low affinity non-specific binding.
