DNA biosensors and biomarkers to cancer detection

Abstract

Cancer is one of the leading causes of death worldwide, and was responsible for 8.8 million deaths in 2015. Globally, nearly one in six deaths is due to cancer [1]. Cancer is a genetic disease where genetics and epigenetics changes can occur, these changes guide to altered gene or protein expression or altered protein composition of cells resulting in alteration of the cycle and cell growth which translates in tumoral phenotypes. Environmental factors (such as diet, lifestyle and exposure to ultraviolet radiation or carcinogenic pollutants) play a major role in the development of some cancer. Genetic changes and environmental factors interact to influence tumor development [2]. Biomarkers and biosensor take advantage of this characteristic of cancer cell to detect certain molecules like DNA, DNA modifications, RNA, proteins or protein modifications or other biological molecules produce by the tumor itself or by the cells around the tumor in response to the presence of cancer. Early detection in cancer is crucial to give an appropriate treatment and to get better outcomes in near and long time in the patients. Biomarkers and biosensors have shown different interesting results on the cancer detection, monitoring and therapy response highlighting the minimally invasive or non-invasive collection of samples. Thus, for example, biomarkers based on protein like CA 15–3 for detection of breast cancer and CA 125 for recurrence of ovarian cancer, or more recently biomarkers in reference to epigenetic changes of gene methylation in breast and ovarian cancer [3]. In the case of carcinoma Hepatocellular, the epigenetic modifications of the gene promoter that involved the synthesis of cyclin-dependent kinase inhibitors p15, p16 and RASSF1A, represent potentially valuable biomarkers for the early and preclinical diagnosis [4]. The last approximation cancer SEEK, which combine genetic markers and protein markers for detection up to five different types of cancer (ovary, liver, stomach, pancreas and esophagus), and estimate the origin of tumor cells in a significant proportion of cases [5]. Additionally, have been studied miRNA, markers with better capacity to predict cancer than DNA or mRNA since a single molecule of miRNA has the capacity to regulate more than one hundred mRNA, with which they have orders of magnitude much greater in terms of the information about the prognosis that they provide us. Currently different molecular biology tools had permitted to develop molecular tumor signatures based on mRNA , miRNA and DNA [6] that can help in tumor classification, subtype and ability to respond to certain therapies nowadays several of these are used in clinical practice [7].