Circulating tumor cells (CTCs) have become a blistering topic of discussion for oncologists because of their tremendous potential in the diagnosis and treatment of cancer. Over the past few years, they have been doled with quite an amount of research in this area understanding that CTCs are shed from tumors and circulate in the bloodstream. This process can also occur at an early stage of cancer. The major limitation in isolation of CTCs is their availability in limited numbers. Hence, many techniques have been developed and are under continuous improvement to enhance their effi cacy of CTC isolation and enumeration. They have shown their potentiality to not just indicate the presence of a tumor but also to provide us with its core information. They have also proven to be useful in detecting minor subgroups of cells present in the primary tissue which might eventually be the cause of treatment resistance or relapse of the disease. Hence, detecting and characterizing CTCs can defi nitely become an inevitable step in treating solid tumor malignancies. In this review, we have tried to comprehend the basics of CTCs including isolation, detection, characterization, and molecular mechanism of their circulation in the blood stream. We have mostly focused on the signifi cance of CTCs in diagnosis and therapies of four most common types of cancers, namely, breast, prostate, lung, and colorectal. This review provides the coverage of most of the advancements with regards to different tumor malignancies and their probable use in predicting outcomes of the disease to realize the concept of personalized medicine.

Chronic Myeloid leukemia (CML) is a disorder causing uncontrolled growth of myeloproliferative blast cells. Tyrosine kinase inhibitors are not really useful in advanced stages and have their own side effects, reactions and resistance as well. Till date, CML can be fully cured only by bone marrow transplantation (BMT) which has its own limitations and thus need further studies to increase better survival of CML patients by this procedure. Our lab at Jaslok Hospital has been working on studying and characterizing mesenchymal stem cells in various types of hematological malignancies. We came up with a concept of isolating and characterizing mesenchymal stem cells (MSCs) from peripheral blood of a CML patient which can be used in combination with Bone Marrow Transplantation in the same CML patient. Our study has shown that the stem cells derived from peripheral blood of CML patient were found to be BCR/ABL -ve . We designated this cell line as a "BCR/ABL -ve " cell line. Molecular characterization of these cells further confirmed their Mesenchymal phenotypes with distinct expression of CD105, CD13 and CD73 genes. Interestingly these cells also expressed pluripotency genes such as OCT4 and NANOG and cytokines i.e. IL6 and TNFα. We further confirmed the normal phenotype of BCR/ABL -ve MSCs by localizing expression of H-Ras, Rb, P53, P16, P21, and EGFR and Ki67 cancer related proteins in these cells by immunofluorescence Microscopy and by in vitro transformation assay. Thus, we suggest that these normal BCR/ABL -ve MSCs derived from CML patient's peripheral blood can be used in addition to BMT procedure for a better recovery of CML disease in near future.