As I know BCL-2 is responsible for programmed cell death, and i believe the relationship between BCL-2 and calcium may have a relationship in inhibiting the cancer cells as I know the lower level of BCL-2 will increase the rate of apoptosis.
BCL-2 proteins regulate ER calcium stores. There are several papers from Craig Thompson's group describing this and also Clark Distelhorst. Use the terms "Thompson CB BCL-2 calcium" or Distelhorst C BCL-2 calcium" and you will find the references in PubMed.
As a starting point you could have a look on PubMed ( http://www.ncbi.nlm.nih.gov/pubmed/15607561 )
"Disparate forms of MK 886-induced programmed death in BCL-2 (+) blood and BCL-2 (-) solid cancer cells and a putative "nuclear" Ca2+ channel: "soil" trumps "seed"? " Anderson et.al., 2005
BCL-2 proteins regulate ER calcium stores. There are several papers from Craig Thompson's group describing this and also Clark Distelhorst. Use the terms "Thompson CB BCL-2 calcium" or Distelhorst C BCL-2 calcium" and you will find the references in PubMed.