英语翻译A Better Understanding Decades of research into the biol

英语翻译
A Better Understanding
Decades of research into the biology of cancer have significantly improved scientists' understanding of how it develops and what drives its growth.Though only 5 to 10 percent of cancers are believed to be inherited,all cancer is genetic; that is,it develops because something in a cell's genes has gone awry."Every time a cell in your body divides,it has to copy the entire blueprint of you," explains Dr.Slamon,chief of hematology/oncology at UCLA's Jonsson Cancer Center,"and there are mistakes frequently made when the body's machinery is copying this blueprint.We have mechanisms that repair these mistakes,but they get less efficient with age." Thus,the longer you live,the more you are at risk of developing cancer.In about 25 percent of all breast cancers,for example,a mutation occurs in which cells produce excess copies of a particular gene that results in the overproduction of growth factor receptors,which are like antennas on the surface of a cell that receive signals telling the cell to divide."You get an overload of growth signals in the breast tissue," says Dr.Slamon,"and you are off to the races with the cells growing." In other cancers,the molecules that regulate cell growth,turning on and off to keep the number of cells in the body constant,get stuck in the on position,so to speak,and cancer cells multiply like rabbits.Here,too,it is a gene defect that causes the molecules to misbehave.

几十年癌症生物学的研究显著提高了科学家对癌症的产生及其成长驱动力的认识.尽管认为只有5%到10%的癌症是遗传的,但是所有的癌症都具有遗传学性质.也就是说癌症的产生是因为细胞内的基因发生紊乱.斯莱蒙博士是加利福尼亚大学洛杉矶分校琼森癌症中心血液学和肿瘤学主任,他说：“体内细胞的每次分裂都复制了个人的所有信息.当体内的体系复制这些信息时通常都会产生一些错误,人体内有修复这些错误的机制.但是随着年龄的增加,修复机制的效率会越来越低.”因此,人活的越久,患癌症的风险越大.以25%的乳癌为例,细胞生长速度超过特定基因的复制速度将导致生长因子受体生长过剩,最终产生突变.生长因子受体像天线一样位于细胞表面,通过接收信号来让细胞分裂.“乳房组织得到过多的生长信号”,斯莱蒙博士说：“人就需要同细胞生长赛跑.”其他癌症中,调节细胞生长的分子不停地开启和关闭来维持体内细胞数的恒定,一旦该分子停留在开启状态,可以说癌症细胞就会飞速生长.这也是由于基因缺陷而导致分子功能紊乱.