Cancer stem cells – friend or foe in the fight against cancer?

Today, following our series on Tumour Microenvironment (TME), and leading on from three recent publications, let’s discuss Cancer Stem Cells (CSCs).

CSCs are part of the TME, as they reside in niches where they can survive from immune surveillance, maintain plasticity and facilitate cancer metastasis (1). They can also circulate around the body. Which makes them so interesting. Their worse effect is that they can expand cancer to other organs in the body, thus helping metastasic. The good thing is that their early detection is a very powerful biomarker for cancer, allowing an early treatment.

The role of each type of CSC is different depending on the cancer, and has different regulation mechanisms. Let’s take breast cancer, for instance. It has been recently described that cancer stem cell survival depends on G-protein coupled receptor EP4 and cyclooxygenase-2 (COX-2) signaling pathways, which upregulate STAT3 (2). Also, autophagy has become a potential therapeutic target for breast cancer since it can regulate breast cancer stem cells maintenance through the modulation of IL6 secretion (3).

So either if you want to block CSCs or detect them, you should consider the markers which are specific for each CSC type. Please see a comprehensive list below.

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Example of a highly-validated anti-CD44v9 antibody (Cat. No. #157MAB12149). Figures show, from left to right: immunofluorescence (human mammary adenocarcinoma cell), WB (Lane 1: no treated, Lane 2: non-targeting siRNA treated sample, Lane 3: CD44 siRNA treated sample #1, Lane 4: CD44 siRNA treated sample #2), IHC (breast invasive ductal carcinoma) and Flow Cytometry (human cancer cell line).

The main limiting factor is the starting amount of sample. Once the CSCs are purified (which is not a trivial thing and must be optimised), the final amounts are in the ng range rather than in the ug range. So be sure to choose very sensitive, very specific and very validated antibodies. One example is CD44 (see figure), which is a marker for CSCs associated to different cancers (prostate, hepatic, gastric, colorrectal, ovarian…).

Working on CSCs and in need of validated antibodies? Leave your comment or contact us!

Cancer Type CSC Markers
Lung Cancer ABCG2(CD338), ALDH1A1, KIT(CD117), PROM1(CD133), THY1(CD90)
Breast Cancer ALDH1A1, CD24, CD44, MET, PON1(ESA), PROM1(CD133), THY1(CD90)
Colorectal Cancer ABCB5, ALCAM(CD166), ALDH1A1, CD24, CD44, EPCAM, DPP4(CD26), ITGB1(CD29), PROM1(CD133), LGR5
Prostate Cancer ALCAM(CD166), ALDH1A1, CD44, PROM1(CD133), TACSTD2(TROP2), ITGA2, ITGB1(CD29)
Gastric Cancer CD44, DLL4, LGR5
Hepatic Cancer ANPEP(CD13), CD24, CD44, PROM1(CD133), THY1(CD90)
Bladder Cancer ALDH1A1, CD44, CD47, CEACAM6(CD66c)
Leukemia CD34, CD38, IL3RA(CD123), KIT(CD117), TFRC(CD71), THY1(CD90)
Pancreatic Cancer ABCG2(CD338), ALDH1A1, CD24, CD44, CXCR4, MET, PROM1(CD133), PON1(ESA)
Brain Cancer ITGA6(CD49f), PROM1(CD133), THY1(CD90)
Ovarian Cancer CD24, CD44, KIT(CD117), MYC, NANOG, PROM1(CD133)
Head and Neck Cancer ABCG2(CD338), ALDH1A1, CD44, LGR5, MET
Melanoma ABCB5, ALDH1A1, MS4A1(CD20), NGFR(CD271), PROM1(CD133)

References

1.- Plaks, V., et.al. (2015). Cancer Stem Cell. DOI: 10.1016/j.stem.2015.02.015.
2.- Foulton, A., et.al. (2015). Cancer Research. DOI: 10.1158/1538- 7445.SABCS14-P2-06-03.
3.- Maycotte, P., et.al. (2015). Molecular Cancer Research. DOI: 10.1158/1541-7786.MCR-14-0487.