Colorectal Cancer- An introduction
Cancer is a genetic disease in which some of the body’s cells grow wildly and multiply in other parts of the body. Cancer is developed because of Genetic changes, especially errors that occur as cells divide, damage to DNA caused by a detrimental substance in surroundings, chromosomal rearrangements, and also inherited from our parents. typically body eliminates the defective DNA prior to it becoming cancerous but the body`s capability to do goes downhill as we age.
As per WHO, Cancer is one of the leading causes of death across the globe and it is projected for nearly 10 million deaths in 2020 out of which colon and rectum cancer cause death of 9,16,000. Colon cancer is a solid tumor that occurs in the large intestine. It generally begins with polyps (non-cancerous) after sometimes it becomes colon cancer. It begins in the rectum and is occasionally called colorectal cancer (CRC).
What Are Cancer Stem Cells (CSCs)?
A specialized subset of cells that is the driving force for recurrences is called cancer stem cells or tumor-initiating cells. Characteristics of cancer stem cells vastly differentiated from normal cancer cells. It will inhibit the tumor suppressor genes and activate the oncogenes. It has more clonogenicity and self-renewing properties, and the proliferation pattern is severely different from normal cells.
Cancer stem cells are more sensitive to chemotherapy and radiation therapy. A tumor with higher cancer stem cell magnitude is quite tricky to treat and it maintains the stemness of the tumor cells.
Drastically numeral improvements’ in the diagnosis and treatment of several cancers. Eventually, there are some challenges to treat various cancers. Fluorouracil, oxaliplatin, and irinotecan are the common chemotherapy drugs that will prescribe after the surgery to clear out persistent cancerous. Even though advances in the drug development process, tumor recurrences and progression due to resistances of anticancer agents boost radiological and chemical leniences.
Approach to decoding the CSCs
Ultimately, targeting the CSCs is the novel way to eradicate the tumor eternally. To develop a strategy this will help to get rid of cancer, explicitly target CSCs, including those targeting biomarkers, key pathways, and microenvironment, and get a capable clinical outcome to the patients. To validate the tumor-initiating properties there is a typical method called Flow Cytometry to segregate the surface markers in the tumor microenvironment by using standard CRC surface markers.
Usually, colorectal CSCs are deciphered through CD133 markers. Aldehyde dehydrogenase(ALDH-1), Prominin 1 (CD133), Leucine-rich G-couple receptor (Lgr5), and RNA binding protein Musashi-1 (Msi-1) are some of the major potential CRC markers in colon cancer.
ALDH1- Prospective CSCs Biomarkers
ALDH1 is the leading marker to find out CRC. ALDH1 role is to oxidation of aliphatic and aromatic aldehydes into carboxylic acids. It is sustaining tumor proliferation and maintenance. In phenotype and genotype expressions of the sorted population of ALDH1 positive cells has more up-regulated gene expression of major cancer-related genes against the ALDH1 negative cells and ALDH1 positive cells have more prone to resistance against the conventional chemotherapy drugs.
As a result, a considerable figure of patients with CRC does not come into sight to benefit from regular chemotherapy, in particular in metastatic disease. It is suggested that the presence of ALDH1+ cells might forecast the response of colorectal cancer to therapy. Numerals of studies have examined the application of ALDH1 as a biomarker in CRC. ALDH1+ CRC cells could potentially be embattled to eliminate the CSC population contained by the tumor, with the desired treatment of dispersed disease and anticipation of recurrences. The novel ways of targeting the microenvironment of CSCs also show potential and need to be investigated.