Comments on: Better Understanding Cancer and Induced Pluripotent Stem Cells Through Their Similarities http://www.allthingsstemcell.com/2009/09/cancer_and_ipsc/ Tue, 11 May 2010 05:50:46 +0000 hourly 1 http://wordpress.org/?v=3.0.1 By: admin http://www.allthingsstemcell.com/2009/09/cancer_and_ipsc/comment-page-1/#comment-1457 admin Wed, 04 Nov 2009 06:49:57 +0000 http://www.allthingsstemcell.com/?p=520#comment-1457 Hi Ruth, Thanks for reading and for your interesting question raised. I am not an expert in this particular stem cell field, but here are my thoughts on your observations. Stem cells change expression of their surface markers (i.e. CD45) as they differentiate, and cancer stem cells in particular most likely have a marker expression profile very different from their progenitor cells. I wrote more about cancer stem cells and surface marker profiles in a previous post, "<a href="http://www.allthingsstemcell.com/2009/07/cancer-stem-cells/" rel="nofollow">Cancer Stem Cells: A Possible Path to a Cure</a>." It's possible these genetically abnormal PBMNCs started out CD45 negative and became CD45 positive (since fewer are positive with the abnormalities), as you suggest. It would be interesting to see if there are more CD45 positive or negative cancer stem cells within the lung tumor itself. Thank you again for the interesting comment. By better understanding cancer stem cells, where they come from and how they lead to cancer, we can learn how to deal with them more effectively. Hi Ruth,
Thanks for reading and for your interesting question raised. I am not an expert in this particular stem cell field, but here are my thoughts on your observations.

Stem cells change expression of their surface markers (i.e. CD45) as they differentiate, and cancer stem cells in particular most likely have a marker expression profile very different from their progenitor cells. I wrote more about cancer stem cells and surface marker profiles in a previous post, “Cancer Stem Cells: A Possible Path to a Cure.” It’s possible these genetically abnormal PBMNCs started out CD45 negative and became CD45 positive (since fewer are positive with the abnormalities), as you suggest. It would be interesting to see if there are more CD45 positive or negative cancer stem cells within the lung tumor itself.

Thank you again for the interesting comment. By better understanding cancer stem cells, where they come from and how they lead to cancer, we can learn how to deal with them more effectively.

]]> By: Ruth Katz http://www.allthingsstemcell.com/2009/09/cancer_and_ipsc/comment-page-1/#comment-1452 Ruth Katz Sat, 31 Oct 2009 11:02:00 +0000 http://www.allthingsstemcell.com/?p=520#comment-1452 I would like your opinion on a frequent finding in purified pripheral blood mononuclear cells (PBMNCs) obtained at baseline in patients with non-small cell lung cancer. The same genetic abnormalities by FISH are found in both CD45 negative and to a far lesser degree in CD45 positive PBMNCs. The genetic abnormalities in the PBMNCs are highly correled with the subsequently resected lung cancers. Could you postulate that a circulating tumor stem cell derived from the primary cancer could undergo differentiation into a CD45 positive cell in the blood or bone marrow accounting for this finding? extrapolating the numbers of these cells based on PBMNC counts and volume of blood collected resulted in up to 100,000 cytogenetically abnormal cells per ml of blood collected. This phenomenon was consistent in over 60 patients with lung cancer and was significantly different compared to controls. I would like your opinion on a frequent finding in purified pripheral blood mononuclear cells (PBMNCs) obtained at baseline in patients with non-small cell lung cancer.
The same genetic abnormalities by FISH are found in both CD45 negative and to a far lesser degree in CD45 positive PBMNCs. The genetic abnormalities in the PBMNCs are highly correled with the subsequently resected lung cancers.
Could you postulate that a circulating tumor stem cell derived from the primary cancer could undergo differentiation into a CD45 positive cell in the blood or bone marrow accounting for this finding? extrapolating the numbers of these cells based on PBMNC counts and volume of blood collected resulted in up to 100,000 cytogenetically abnormal cells per ml of blood collected. This phenomenon was consistent in over 60 patients with lung cancer and was significantly different compared to controls.

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