Prospectively Isolated Cancer-Associated CD10+ Fibroblasts Have Stronger Interactions with CD133+ Colon Cancer Cells than with CD133− Cancer Cells

Although CD133 has been reported to be a promising colon cancer stem cell marker, the biological functions of CD133+ colon cancer cells remain controversial. In the present study, we investigated the biological differences between CD133+ and CD133− colon cancer cells, with a particular focus on their interactions with cancer-associated fibroblasts, especially CD10+ fibroblasts. We used 19 primary colon cancer tissues, 30 primary cultures of fibroblasts derived from colon cancer tissues and 6 colon cancer cell lines. We isolated CD133+ and CD133− subpopulations from the colon cancer tissues and cultured cells. In vitro analyses revealed that the two populations showed similar biological behaviors in their proliferation and chemosensitivity. In vivo analyses revealed that CD133+ cells showed significantly greater tumor growth than CD133− cells (P = 0.007). Moreover, in cocultures with primary fibroblasts derived from colon cancer tissues, CD133+ cells exhibited significantly more invasive behaviors than CD133− cells (P<0.001), especially in cocultures with CD10+ fibroblasts (P<0.0001). Further in vivo analyses revealed that CD10+ fibroblasts enhanced the tumor growth of CD133+ cells significantly more than CD10− fibroblasts (P<0.05). These data demonstrate that the in vitro invasive properties and in vivo tumor growth of CD133+ colon cancer cells are enhanced in the presence of specific cancer-associated fibroblasts, CD10+ fibroblasts, suggesting that the interactions between these specific cell populations have important roles in cancer progression. Therefore, these specific interactions may be promising targets for new colon cancer therapies

Solid state electrochemistry of direct carbon/air fuel cells

In direct carbon fuel cells (DCFCs), elemental carbon is electrochemically oxidised to generate electrical power. Carbon is readily available, easily transported and stored and, therefore, affordable to the global energy economy. Further operational advantages include the use of fully renewable solid bio-carbon fuel sources and the opportunity for scale-up. Herein we discuss a DCFC which utilises a molten mixed alkali metal carbonate eutectic as a secondary electrolyte, contained within a solid oxide fuel cell. The operation of small cells working as semi-fuel cells has been successfully demonstrated over an extended temperature range (525-900 degrees C) using a range of carbons derived from fossil, renewable and waste sources. Preliminary mechanistic studies demonstrate open circuit voltages (OCVs) well in excess of I V and indicate that direct oxidation and Boudouard conversion both contribute to the conversion process, with the dominant process changing with both temperature and extent of molten electrode/electrolyte component. (C) 2008 Elsevier B.V. All rights reserved.</p