new GM crop--plant made herceptin-- may provide herceptin at lower cost!

[Lani]

PLoS One. 2011 Mar 3;6(3):e17541.
Plant-Made Trastuzumab (Herceptin) Inhibits HER2/Neu+ Cell Proliferation and Retards Tumor Growth.
Komarova TV, Kosorukov VS, Frolova OY, Petrunia IV, Skrypnik KA, Gleba YY, Dorokhov YL.

A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia.
Abstract
BACKGROUND: Plant biotechnology provides a valuable contribution to global health, in part because it can decrease the cost of pharmaceutical products. Breast cancer can now be successfully treated by a humanized monoclonal antibody (mAb), trastuzumab (Herceptin). A course of treatment, however, is expensive and requires repeated administrations of the mAb. Here we used an Agrobacterium-mediated transient expression system to produce trastuzumab in plant cells.

METHODOLOGY/PRINCIPAL FINDINGS: We describe the cloning and expression of gene constructs in Nicotiana benthamiana plants using intron-optimized Tobacco mosaic virus- and Potato virus X-based vectors encoding, respectively, the heavy and light chains of trastuzumab. Full-size antibodies extracted and purified from plant tissues were tested for functionality and specificity by (i) binding to HER2/neu on the surface of a human mammary gland adenocarcinoma cell line, SK-BR-3, in fluorescence-activated cell sorting assay and (ii) testing the in vitro and in vivo inhibition of HER-2-expressing cancer cell proliferation. We show that plant-made trastuzumab (PMT) bound to the Her2/neu oncoprotein of SK-BR-3 cells and efficiently inhibited SK-BR-3 cell proliferation. Furthermore, mouse intraperitoneal PMT administration retarded the growth of xenografted tumors derived from human ovarian cancer SKOV3 Her2+ cells.

CONCLUSIONS/SIGNIFICANCE: We conclude that PMT is active in suppression of cell proliferation and tumor growth.

PMID: 21390232 [PubMed - in process]

It is not a new idea http://www.ncbi.nlm.nih.gov/pubmed/20799692

[Lani]

Dr. Ronald Levy at Stanford who invented the first monoclonal antibody, Rituximab, against lymphoma, has been talking about this for at least 15 years.

Ineteresting, and why nobody has done it?

[Lani]

Probably regulatory problems. If plants grow our drugs, who regulates the product, FDA or Dept, of Agriculture.

Drug companies are a lot more powerful than farmers, also

They have for another example been talking for about 30 years about making flu vaccines in another way than growing them in eggs--and only now is this new technology MAYBE going to start becoming available.

Things don't alway move quickly in drug/vaccine development especially when an entirely new technology is involved

But now russian scientists WILL try it or it will be just an abstract?

[Lani]

the principle of using tobacco or other plants to make drugs has been around for so long and known worldwide, and of course, all scientists around the word are entitled to read the world's literature and attend conferences

No particular country holds exclusivity on innovation or bureaucracy(sp?)

[SoCalGal]

This would be great news for people such as myself, who develop antibodies to Herceptin - been told it has to do with the partially humanized aspect.

SoCalGal, what does it mean, does Herceptin work for you?

[Lani]

How did they diagnose you were making antibodies against herceptin?

It would make more sense if it were the Chinese hamster ovary 1% you were allergic too rather than the 99% humanized part.

[SoCalGal]

This was the theory explained to me by one of my Docs (MD & pharmacology PhD but not oncologist). He said the reason I am having an allergic reaction (red ears, creepy weird feelings, numb hands, arms and chest at infusion time) is that my body has most likely developed antibodies against Herceptin. Said that when this happens, even if Onc were to suppress histamine response w/benedryl, that my body will clear the herceptin w/in 5 hours as opposed to 5 days. He said that I've probably not benefited for the past 6 - 9 months - all info "just" in his opinion of the body science leading up to a reaction. He wants to see what my onc has to say. I am anxiously awaiting my April 1 appointment. Everytime I think I am being as brave as I possibly can be, the bar is raised. Sigh...