Colon cancer is one of the most common types of cancer in India and around the world. According to the Indian Council of Medical Research (ICMR), it is the third most common cancer in men (6.63 million cases in 2014, accounting for 10.0% of all cancer cases) and the second most common in women (5, 71,000 cases in 2014, 9.4 percent of all cancer cases).
Colon cancer is currently detected at an advanced stage. It can be detected using either CT colonography and colonoscopy or immunohistochemistry.
While CT colonography uses low-dose radiation, colonoscopy is an invasive procedure, and immunohistochemistry can be subjective and sometimes unreliable.
A new collaborative study led by Dr. Sagar Sengupta at the National Institute of Immunology (NII) and involving four institutes in India and one in France has discovered a new way to identify the disease even at Stage I, the earliest stage.
Dr. Sengupta’s lab studies micro RNAs, which are small single-stranded non-coding RNA molecules that suppress the expression of many proteins. Micro RNAs are known to bind to messenger RNA molecules that code for proteins, inactivating or destroying them.
The new study discovered that six microRNAs are upregulated in colon cancer cells and that their levels are regulated by a master regulator protein known as CDX2. Importantly, the upregulated micro RNAs, known as DNA damage sensitive micro RNAs or DDSMs, were discovered to target a group of cellular proteins that are required to keep genetic material pristine within each cell of the body.
Experiments with laboratory mice confirmed that when these micro RNAs are overexpressed, the cells have a greater proclivity to form cancers due to the loss of these genome stabilizers.
The DDSMs were found to be upregulated even in Stage I colon cancer tissues. The upregulation persisted all the way through Stage IV colon cancer. More importantly, increased DDSM expression in cancer patients decreased their chances of survival.
Dr. Sengupta told India Science Wire, “We believe that the identified DDSMs can serve as an invaluable biomarker for colon cancer early detection.” We now need to see if the DDSMs can be detected in patient blood samples. If that is possible, it would make detecting colon cancer as simple as detecting blood sugar in diabetic patients.”
In addition to the NII and AIIMS in New Delhi, the Regional Centre for Biotechnology in Faridabad, St. John’s Research Hospital in Bengaluru, and the University of Strasbourg in France all contributed to this research. The findings have been published in the Journal of Cell Science.
This is a fantastic technological advancement that will undoubtedly help save cancer patients’ lives.