英属哥伦比亚省大学的研究人员的新发现，将有助于研发出无毒且专一性的乳癌及卵巢癌转移疗法。
之前研究人员证实一种名为足细胞标记蛋白－Podocalyxin(PCX)的蛋白质，是乳癌转移的预测因子。而在这项新发现中，研究人员发现podocalyxin会改变肿瘤细胞的形状和肿瘤细胞的黏附力，影响它们生长及转移的能力。
转移的癌症是从原始的病灶转移到身体其它部位的蔓延性癌症。这项发现显示，podocalyxin不仅可以用于预测乳癌细胞的传播，也可能促成癌症转移。
这项研究结果发表于Public Library of Science网络版中。研究人员相信，他们找到了与乳癌转移有关的重要蛋白质。研究人员的最终目标是研发出可以瞄准podocalyxin的无毒的疗法。
据加拿大癌症协会估计，2006年在加拿大，超过22,000名妇女经诊断罹患乳癌且5,300人死于乳癌。而2006年约有2,300个卵巢癌新病例被诊断出，且大约有1,600名妇女死于卵巢癌。
(资料来源 : Bio.com)
原文出处：
UBC Discovery may Lead to 'Smart' Therapies for Breast, Ovarian Cancer
03/19/07 -- New non-toxic and targeted therapies for metastatic breast and ovarian cancers may now be possible, thanks to a discovery by a team of researchers at the University of British Columbia.
In a collaboration between UBC stem cell and cancer scientists, it was found that a protein called podocalyxin ? which the researchers had previously shown to be a predictor of metastatic breast cancer ? changes the shape and adhesive quality of tumour cells, affecting their ability to grow and metastasize. Metastatic cancer is invasive cancer that spreads from the original site to other sites in the body.
The discovery demonstrated that the protein not only predicted the spread of breast cancer cells, it likely helped to cause it. The findings were recently published online by the Public Library of Science.
"We believe we?ve found a new important culprit in metastatic breast cancer, which opens up an entirely new avenue of cancer research," says Calvin Roskelley, an associate professor of cellular and physiological science who specializes in breast cancer and is co-senior principal investigator. "The culprit is hiding in plain sight on the surface of tumour cells, so we are now developing "smart" molecules to block its function. The ultimate goal is to generate new targeted, non-toxic treatments ? very different from the standard ?slash and burn? chemotherapy."
The researchers found that podocalyxin significantly expands the non-adhesive face of cells, allowing individual cells to brush aside adhesion molecules situated between tumour cells. The "freed" cells then move away from the original site to form new tumours at other sites. Also, the protein causes tumour cells to sprout microvilli, or hair-like projections, that may help propel cancer cells to other sites.
In addition, when the protein expands the non-adhesive face of cells it drags along with it a second protein called NHERF-1 ? a protein shown by others to be implicated in cell growth and invasion. The researchers now believe the mechanism applies to difficult-to-treat invasive breast and ovarian cancers.
"We?re now tapping into what causes the characteristic cell shape changes seen in cancerous tumours and possibly how these cells grow and metastasize. It gives us a whole new target for therapy," says Assoc. Prof. of Medical Genetics and stem cell expert Kelly McNagny, co-senior principal investigator. "If we can block the protein, we may be able to stop the spread of cells."
Post-doctoral Fellow Julie Nielsen, of UBC?s Biomedical Research Centre, and PhD student Marcia Graves of the Dept. of Cellular and Physical Sciences, were instrumental in designing and executing the research experiments, he adds.
Next steps involve advancing the research in animal models, designing antibodies to block the function of the protein and working with the UBC-based Centre for Drug Research and Development to identify new therapies to combat metastasizing cancer.
The researchers say information from this discovery may speed development of new therapies to within 10 years.
In 2006, more than 22,000 women were diagnosed with breast cancer and 5,300 died of it, according to estimates from the Canadian Breast Cancer Foundation. The Canadian Cancer Society estimates that approximately 2,300 new cases of ovarian cancer were diagnosed and about 1,600 women died from the disease in 2006.
Source: University of British Columbia
