Does an increase in cancer cell traction forces increase metastasis of the cancer cells? I am not very familiar with biology, but I have read some articles about cell traction forces lately, where the cells are cancer cells. I found this very interesting, so I thought it might be nice to read about the relationship between cell traction forces and metastasis for cancer cells. I thought that an increase in cancer cell traction force should indicate that there would be more metastasis. I have looked at two references, but one of the articles says that increasing the cell traction force increases metastasis [Kraning-Rush et al. (2012)], while the other says the opposite [Indra et al. (2011)]. Both are experimental articles. My question is therefore: Is it correct that most often, an increase in cancer cell traction forces would increase metastasis, or should it most often decrease metastasis?

You have pointed out in your question that two different research groups have differing conclusions about your question. The answer is not known which is why they are studying it.

Their differing results probably turn on how cell traction force is defined and the experimental system used to measure it. It may not even be consistently ture - for example metastasis via the lymphatic system may be mediated by different properties than metastasis through the bloodstream or local tissue invasion.