Long Non Coding RNA HOTAIR and Midkine as Biomarkers in Thyroid Cancer

Thyroid cancer is the most prevalent endocrine malignancy.Papillary thyroid carcinomas and follicular thyroid carcinomas account for 95% of all thyroid cancer cases. They are clinically classified as well-differentiated thyroid carcinomas due to their biological behavior resembling normal follicular cells and good responsiveness to surgery and radioiodine therapy . However, they are usually curable when discovered at early stages, but survival rates may be reduced from 100% in stages I and II to 50% at stage IV So,early detection is the key for successful treatment and reduction of mortality.

pathological analysis by fine-needle aspiration biopsies has some limitations including difficulty in sampling small tumors, inconclusive diagnosis in up to 35% of patients and bleeding. Thus, biomarkers for diagnosis are needed.

The concept of liquid biopsy was proposed in contrast to the traditional tissue biopsy which is particularly important for solid tumor diagnosis. It refers to the process of detecting genetic materials, using non-invasive method from blood or other body fluids.Long noncoding RNAs (LncRNAs) have recently been demonstrated to participate in cancer progression.HOTAIR is the type of non coding RNA that will be investigated for its ability to differentiate benign from malignant thyroid nodule Midkine a basic heparin-binding growth factor of low molecular weight, capable of exerting activities such as cell proliferation, cell migration, angiogenesis and fibrinolysis. Midkine expression is closely related with progression of tumor stage. If tumor tissues increase secretion of midkine, it becomes evident in serum.The expression of midkine gene in human tumor cells may reflect tumor formation and give clues to the biological behavior of neoplasms. Hence, the expression of midkine may serve as a tumor marker for diagnosis and follow-up.