I think copper may also be important as it is required for lysyl oxidase enzym es.. These enzymes are well known to be causing cancer in various studies... Role of transition elements may also be investigated.. 

arsenic, cadmium have also been shown to cause cancer..

Thanks, but what I need to know is what metals uses the tumor in it metabolism, like the case of iron, cancer cells need an excess of iron for cell proliferation. 

So, my question isn't about what metals cause cancer, but, what metals does the cancer need in excess, for it metabolism.

Hi, I think the question is impossible to answer. The tumor consumes what it can. The fast-proliferating tumor cells soon switch to autophagy (self-eating) as they cannot get nutrients from outside due to incomplete and leaking vasculature which is caused by the high proliferation rate.

Of course, the more malignant the tumor, the more mutations there are, but I would presume that they do not start using more new elements/metals as a source of nutrition or survival very easily, as it would require changes in the metabolic processes. If iron promotes metastasis, they use iron for that, but accidentally, if surplus iron is available.

To answer your question, I do not know. There is a threshold need for each nutrients and the threshold is dynamic (an interconnected network). With each nutrient /element there can be too little or to much. Tricky stuff. Anyway, the significance of the metals is clear, but the mutations in the tumor-inducing pathways are the major driving force in tumor development. 

any help?

Probably, there is no clear answer to this question. It depends on many parameters, including both type of tumor and tissue, stage of cancer, etc. For example, see Table 1 in the enclosed two links. Also, below mentioned publication may be useful.

http://cancerres.aacrjournals.org/content/44/11/5390.full.pdf

http://cancerres.aacrjournals.org/content/49/15/4210.full.pdf

Article Trace elements as tumor biomarkers and prognostic factors in...

Thank you for trying to answer my question, to both of you!

I'm gonna read the articles righ now! 

Glycolysis is upregulated in tumor cells. One of the main enzymes of glycolysis is Fructose-bisphosphate (aldolase) which requires cobalt as a cofactor.

All the enzymes of glycolysis involve some metals as Co factors.. So these metals may be important in tumors growth. They may influence the tumour growth rate by influence the enzymatic activity.

Consider Zinc. Beyond actual mutations in critical genes, carcinogenesis involves the derangement of a great many functions, arguably distorting expression of various genes to "maximum", if there is any growth advantage. The regulatory role of Zinc Fingers is substantial, and zinc supply to the tumour may be limiting to some extent. Partial resistance to reactive oxygen species generated by inflammation and immune attack, or from some cancer therapies might be conferred by Superoxide Dismutase which uses a Zinc cofactor.

Good luck.

Manganese, zinc, selenium and copper "biometals" can be disregulated in tumor cells such as in neurodegenerative disorders. These metals are cofactor of enzymes involved in oxidative stress response (SOD1, SOD2, GPX..) than you should check if their homeostasis is alterated in the cells you are studying with enzimatic assay and also quantify these metals...

Regards

Stefania

Metalloenzyme is deeply related to the regulation of glycolysis, mTOR-dependent amino acid metabolism, and DNA synthesis. This is also the case in cancer cells much the same as in normal cells.    

i.e. Zinc-mediated enzyme activity for cancer cell proliferation 

Zn is an essential cofactor for cell proliferation, differentiation and apoptosis . During normal cell cycle progression, Zn is requisite for G1/S transition and DNA synthesis. Zn limitation causes DNA synthesis and growth arrest indicating that Zn is also required for S phase, thereby potentiating a growth period enriched in both cellular transcription and translation.