Is Cancer Stem Cell the “Messiah of Cancer Cure”?

The existence of cancer stem cells have started as a hypothesis and followed by enormous number of experimental evidences. Still, a large number of scientists in stem cell areas and other research areas are very skeptical about the existence of cancer stem cells. We can believe the existence of cancer stem cells and its role in cancer from all the reported studies on the isolation/characterization of cancer stem cells in various cancers such as leukemia, breast cancer, ovarian cancer, lung cancer, liver cancer, colon cancer etc from past and ongoing research on cancer stem cell. The PubMed searches on cancer stem cells showed more than 5000 articles as of October 2009 and this data indicates that the first research article on cancer stem was published on 1976 (see the box to see all the PubMEd search results). It is evident that the concept of cancer stem is known to us for more than 23 years. If the scientist would have accepted the existence of cancer stem cells a decade ago, possibly we would have been in a better position in finding a cure for cancer or may be closer to achieve this goal? May be the concept of stem cells were not established at that time?

We speculate that the real benefit of stem cells will not come from in vitro differentiation of embryonic (hES) or induced pluripotent (iPS) stem cell into tissues or organs or the injection of stem cells. Better not to be, because these stem cells may be similar to cancer cells (1) and may carry several genetic mutations (2). We do not know the genetic safety of current in vitro grown cells in stem cell therapy. Read more: http://www.sciclips.com/sciclips/blogMain.do

Absolute quantitation of peptide/protein using mass spectrometry:Is it a Fact or a Fiction?

Considerable efforts have been made to develop tools for the absolute quantitation of peptide/protein using mass spectrometry (MS). Proteomics researchers are so fascinated with the concept of absolute quantiatation and they are spending enormous amount of time for developing tools or optimizing methods for the absolute quantitation of proteins in a cell or tissue or organ. These experiments and technology development efforts not only take lot of time but also involve huge capital investment. The question is, whether it is worth spending so much money in these efforts? The arguments for justifying such studies are that it is necessary to understand the absolute quantity of a protein for quantitative proteomics. This will enable us to quantitate exact amount of toxins in food/environment, biomarker proteins and drug target proteins and so on. It looks very reasonable to measure the exact quantity of a disease biomarker or Staphylococcal enterotoxins in various foods.

Let us take an example of measuring Staphylococcal toxins in a meat sample. By using expensive isotopically labeled peptides or complex in vivo/in vitro expression system derived proteins/peptides or various software intense label-free methods, we can measure the exact amount of toxins present in the meat sample. Now, we need to see, is there any real practical applications of this information? Do we really need to know the exact concentration of toxins? What are the advantages of this method over antibody based ELISA approaches, which are more frequently used; less expensive and more robust? Read more: http://www.sciclips.com/sciclips/blogMain.do

p53 – A guardian angel in regulating normal and cancer stem cell states

The p53 is a tumor suppressing proteins that activates DNA repair proteins and apoptosis pathways in response to DNA damages that are not irreparable. Mutations in p53, which affects its activity, are responsible for developing various cancers; 83% of tumors have alterations or defect in p53 (1). The p53 plays crucial role in embryonic stem (ES) cells. p53 represses the expression of Nanog, a transcription that is critical for the self-renewal of ES cells (2). Loss of p53 reduces spontaneous differentiation and apoptosis in human embryonic stem cells (3). It has been proposed that breast cancer tumors can originate from cancer stem cells or cancer cells become stem cells due to p53 deficiency, which favors the expansion of cancer stem cells (4). Recent reports (shown below in boxes) have shown the importance of p53 in various stem cell states. Independent studies from five laboratories have shown that loss ofp53 is needed for the induction of induced pluripotent stem cells (iPS cells) from adult cells (see thumbnails). The role of p53 in cancer stem cells has been shown by a recent study . This study has shown that loss of p53 induces symmetric cell division in breast cancer stem cells and this favors breast cancer tumor growth. Read more: http://www.sciclips.com/sciclips/blogMain.do