The presence of stem cells in ovarian cancer: a review

Abstract

Ovarian cancer is one of the deadly gynecological malignancies. The disease has usually difficult to detect at the early stage as there are only a few specific symptoms and not many screening methods, thus patients usually come in an advanced and metastatic stage of the disease. Initial therapy for the disease includes surgery to remove the tumor, then followed by chemotherapy. This therapy shows a promising result at first until some sign of reoccurrence starts to show. One of the main reasons is thought to be the presence of a small subset of cells called cancer stem cells (CSCs). These cells may escape from the initial therapy, and due to the CSCs' ability to self-renew, grow into various lineages, and multiply widely. There are multiple efforts done to isolate and identify this subset cell, such as identifying the specific antigen in the cell surface, using Side Population, the ability of CSCs to form floating spheres in serum-free media, and the level of ALDH expression. Such methods have been performed together to identify purely cancer stem cells from the malignancy. The ability of the cell to produce new tumors in immuno-deficient animals, however, is the gold standard for identifying CSC, according to the current study. This review will discuss several methods that have been used to isolate cancer stem cells and prove the stemness of these cells by injecting them into immuno-deficient mice. Cancer stem cells also can avoid the effect of chemotherapy. Several things contribute to this ability. This review there will discuss methods that have been several things that make it possible to be able to escape chemotherapy drugs. By understanding these mechanisms, hopefully, new therapy modalities will be developed and specifically targeted, so that can be used to treat malignancies more effectively.