Scientists discover a new way to detect early colon cancer
Colon cancer is a common type of cancer, both in India as well as worldwide. The Indian Council of Medical Research, (ICMR) states that it is the third most prevalent cancer among men (6,633,000 cases in 2014; 10.0% of all cancer cases), and the second most common among women (5,711,000 cases in 2014., 9.4% of all cancer cases).
Currently, colon cancer is detected in the late stages. There are two techniques to detect it; either CT colonography and colonoscopy or immunohistochemistry. Although CT colonography uses low dose radiation, colonoscopy involves an invasive procedure. Immunohistochemistry is subjective and may not be reproducible.
New collaborative research involving four Indian and one French institutes, led by Dr. Sagar Sengupta, National Institute of Immunology (NII), discovered a way to identify the disease at Stage I.
Dr. Sengupta works in the laboratory on microRNAs. These are single-stranded, non-coding RNA molecules that silence many proteins. It is known that microRNAs bind to messenger RNA molecules, which code for proteins to either inactivate them or destroy them.
A new study found that six microRNAs are upregulated in colon cancer cells. This master regulator protein, CDX2, was responsible for controlling their levels. The upregulated micro RNAs were called DNA damage sensitive micro RNAs' or DDSM's and target a set of cellular proteins that are critical to maintaining the purity of each cell's genetic material. Experiments with laboratory mice showed that cells are more likely to develop cancer if they have too many microRNAs.
The findings were tested on publicly available data in The Cancer Genome Atlas and in a cohort of patients with colon cancer who came to All India Institute of Medical Sciences, New Delhi for treatment. Analyses were done using the data from over 410 patients as well as the biopsy materials from 54 patients at AIIMS, New Delhi.
The DDSMs had been found to be upregulated in Stage I colon carcinoma tissues. This upregulation continued until the final Stage IV colon carcinoma. Moreover, patients with cancer had a lower chance of survival if they expressed more DDSMs.
Dr. Sengupta spoke to India Science Wire and stated that the DDSMs identified can be used as a biomarker for early detection of colon cancer. Now, we need to find out if the DDSMs are also detectable in blood samples from patients. It would be as easy as detecting colon cancer in diabetic patients if that was possible.
This study was supported by France, NII, AIIMS, Faridabad Regional Centre for Biotechnology and Faridabad. The Journal of Cell Science has published a report about the research.