Department of Internal Medicine

Laboratory Medicine

Innovation in disease concepts using novel diagnostic methods
  • Validation of the fetal cell carcinogenesis theory
  • Development of a cancer stem cell detection method by FACS-mQ
  • Development of a nucleic acid aspiration method to diagnose thyroid cancer
  • Elucidation of the pathogenesis of autoimmune diseases
  • Improving the accuracy of clinical tests

Changing commonly accepted paradigms in medicine by clinical analysis

Day-to-day clinical examinations are essential to acquire information about patients. The lab has been using data from clinical examinations to propose novel disease models. As a result, several innovative breakthroughs have been made that led to a paradigm shift, particularly in the field of thyroid disease.

The most widely accepted theory of carcinogenesis states that cancer is generated by multistep process in which benign cells become malignant after an accumulation of genetic alternations. However, the lab proposes a new theory of thyroid carcinogenesis that caner arises from the remnants of developing fetal cells which possess cancerous characteristics.


This theory has recently gained recognition in many major international journals (e.g. Nature Reviews Endocrinology, Oncogene, and Journal of Clinical Endocrinology and Metabolism) as an explanation for the development of thyroid cancer. Furthermore, it helps to explain why thyroid cancer was detected in a large number of young people after the Fukushima Daiichi Nuclear Power Plant accident.

Based on our fetal cell carcinogenesis, we are developing novel, state-of-the-art clinical diagnostic methods. To this end, the lab has developed two methods for diagnosing thyroid cancer. The first involves the extraction of nucleic acids by fine needle aspiration. The technique can be particularly useful for preoperative diagnosis of thyroid follicular cancer, which accounts for 5-10% of thyroid cancers and is difficult to diagnose. A diagnostic kit was developed and a preclinical test is now ongoing. Since nodules in the thyroid gland are frequently observed in about 10% of adults, this method will be widely used in the near future.

For the second diagnostic method, the lab has developed a new technique called FACS-mQ for the detection and analysis of cancer stem cells. By using this method, cells can be fluorescently labeled, sorted and collected without a loss of RNA. Then, mRNA expression levels in cells collected by FACS can be quickly analyzed. FACS-mQ is also expected be a useful analytical tool for other applications in regenerative medicine.