Emory University have done it again... "Progesterone Inhibits Growth of Neuroblastoma Cancer Cells"
Emory were the first to give us the extraordinary news that progesterone in amounts exceeding 1200mg/day, would help Traumatic Brain Injury.
During this research, they found that progesterone caused significant cell death in brain tumours. Following on from this discovery they tested the progesterone against neuroblastoma.
This brain tumour is the most common cancer amongst children under a year. Accounting for about 28% of all cancers diagnosed in European and U.S. infants.
The paper goes on to say....."High natural P4 levels during pregnancy are associated with a lower incidence of maternal breast cancer and also appear to exert a long-term protective effect against breast cancer. The antiproliferative and apoptotic effects of P4 have been reported for breast, endometrial, ovarian, colon and salivary gland tumors in vitro and in vivo. Taken together, these facts suggest ways in which natural P4 might function as a chemotherapeutic agent against neurogenic tumors such as neuroblastoma."
They further state that.... "Our findings can be taken to suggest some P4 specificity in inducing the death of tumor cells. Thus, the hormone apparently can differentiate between normal healthy cells and tumor cells and specifically induces cell death in neuroblastoma while remaining nontoxic or protective for normal cells...... We selected the high P4 doses on the basis of our in vitro data and our previous reports that P4 is neuroprotective at lower doses (8 and 16 mg/kg) against traumatic brain injury and stroke.
They also found low amounts of progesterone encouraged tumour growth.......
"In a comparative study, Wiehle et al. tested RU486, P4 and CDB-4124 (nor-progestin) against mammary tumors in vivo and observed that P4 treatment at 10 mg/kg for 28 days increased the size and number of tumors in female rats. We speculate that P4’s tumor-promoting effect in the Wiehle et al. study could be because of the lower dose used compared with the present study, demonstrating a hormetic effect of the hormone. In our study, tumor suppression required 5–10× the dose in the experiments performed by Wiehle et al., further suggesting that P4 has a bimodal effect."
This has been my argument all through the sixteen years I've been doing this work. Too low an amount of progesterone will stimulate oestrogen and cause all manner of adverse symptoms.
I often mention the MMPs, usually in reference to heavy, continual bleeding. Although they are necessary for tissue remodelling, in excess they cause a continual break down of tissue. They are also implicated in arthritis and cancer. Oestrogen stimulates their production, which would encourage any tumour to grow.
The study found a significant decrease in the expression of MMP-2 and MMP-9.
Too many women are told to stop progesterone by their doctors because it will cause cancer, cause clots, cause depression etc etc.
Another myth propagated by those in the medical profession who know nothing about progesterone, is it's pointless if a woman doesn't have a uterus. Nothing could be further from the truth. As the study says....
"Because P4 is a pleiotropic agent with a variety of molecular mechanisms, it is likely that multiple gene or receptor-specific mechanisms are involved in its antitumor action against neuroblastoma. In support of the notion that P4 is pleiotropic, a recent microarray study reported that high doses of P4 applied to endometrial tumor cells affected the expression of 247 genes, including many involved in the control of the cell cycle, proliferation, differentiation and the immune inflammatory response.....P4 has previously been reported to inhibit proliferation and induce apoptosis in a variety of tumor cell lines other than neuroblastoma....It appears that P4 has potent antiproliferative and proapoptotic effects in neuroblastoma.....We observed that P4 alone at a very low concentration (0.01 μmol/L) showed an increase in cell proliferation."
The study concludes......
"Although much more research is needed before going to clinical trial, we should consider whether P4 could be used alone or in conjunction with reduced levels of radiation, surgery or chemotherapy to improve patient survival and functional outcome."
I hope this study will reassure people of the safety of progesterone. The levels used, 50-100mg/kg, which is 2500mg to 5000mg/day for a person weighing 50kg (110lbs) are remarkably high.
No toxicity was observed at all. Only the tumour was affected, the healthy cells were untouched.
Emory University, Woodruff Health Sciences Jul. 13, 2011
Progesterone Inhibits Growth of Neuroblastoma Cancer Cells
MOL MED 17(9-10)1084-1094, SEPTEMBER-OCTOBER 2011
Progesterone Inhibits the Growth of Human Neuroblastoma: In Vitro and In Vivo Evidence