It is surprising in the following editorial that monocytes promote extravasation, which is the rate-limiting step of the distant metastasis! What about neutrophils!? Do they promote or suppress the metastasis?
http://www.nejm.org/doi/full/10.1056/NEJMcibr1606716
Dear Prof. Yoshida,
In recent years, several in-depth basic science researches have clearly shown that the most abundant white blood cells, neutrophils, are potentially associated with the promotion of cancer metastatic establishment in various solid tumor models.
Your excellent question prompted me, a medical oncologist, to freely think that, perhaps one of the beneficial effects of the adjuvant chemotherapy given to a patient to prevent future distant metastasis might derive from the suppression of neutrophils after the adequacy of dose-intensive chemotherapy. This chemotherapy-induced neutropenia may benefit a patient with high-risk for distant metastatic establishment analogous to the phenomenon of chemotherapy-induced ovarian failure which benefits premenopausal women with estrogen receptor-positive breast cancer through the hormonal pathway.
many studies indicate the pro-metastatic role of Neutrophils , however there are other studies suggest the opposite.
further, Neutrophils role not limited to metastasis as many experimental studies suggest a major role in tumor initiation.
I advise you to read this excellent review in first link.
and this article (2nd link).
http://www.nature.com/nrc/journal/v16/n7/full/nrc.2016.52.html
http://www.nature.com/nature/journal/v528/n7582/full/nature16140.html
I have thought of the novel report by Cancer Cell about tumor-entrained neutrophils, which behave similarily as compared with tumor-associated macrophages.
Tumor entrained neutrophils inhibit seeding in the premetastatic lung.
Granot Z, Henke E, Comen EA, King TA, Norton L, Benezra R.
Cancer Cell. 2011 Sep 13;20(3):300-14. doi: 10.1016/j.ccr.2011.08.012.
Article Tumor entrained neutrophils inhibit seeding in the pre-metas...
It was shown recently in breast cancer that the presence of neutrophils could be poor prognosis.
Mainly when neutrophils were in close contact with pDCs; the role of LL37 (hCAP18) was therefore invoked.
This trilogy: neutrophils, pDCs and LL37, seems to represent a target for understanding the occurrence of the very poor prognosis value.
The involvement of certain bacteria are also investigated.
For information: CLARA Congress 2016
Dear Go all the above answers are interesting and based on data generated from different experimental schemes and consequently with different results. The results are not questionable and the question is still unsolved.
In human patients with cyclic neutropenia, there is no correlation about incidence of solid tumors and low neutrophil counts. The same is true with other minor disorders of neutrophil function. In more compromised immunodeficiencies other results have been observed. Thus, I do not think that neutrophils are directly link in cancer metastasis; however, in the tumor microenvirovment they, as m2 macrophages, may facilitate tumor migration. In the periphery, the tumor cell may easily travel until it reaches another organ, but that does not mean that is facilitates metastasis. It is a redears opinion from the two different results reported, regards
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Agree with Jean-Jacques Pin. Neutrophils are one of the main sources of LL-37 (the other is epithelia), known for its roles in tissue repair mechanisms which include enhancement of epithelial cells proliferation (putative role in carcinoma development) and angiogenesis (=metastasis promotion). Furthermore, the triad neutrophil, pDCs and LL-37 are involved in chronic (in situ) inflammation, another promoter of cancer development.
Regarding your question Go J Yoshida, I would say (is my personal conclusion) they contribute to promote metastasis in an tumor escape scenario. Nevertheless, their tumor supression functions in an proper immune surveillance scenario, indicate that they are not bad but their goodnesses can be used as advantage by the tumor once established.