DeOme K B, Miyamoto M J, Osborn R C, Guzman R C, Lum K
Cancer Res. 1978 Nov;38(11 Pt 2):4050-3.
Inapparent nodule-transformed cells were recovered from five late-pregnant, first-pregnancy BALB/cfC3H females 4 months of age and from five late-pregnant multiparous females 6 to 7 months of age. Mammary tissues were removed from each donor and dissociated by means of the enzyme collagenase (0.1%), hyaluronidase (0.1%), and pronase (1.25%). Aliquots of 100,000 viable cells in 0.01 ml of media were injected into the gland-free mammary fat pads of 3-week-old syngeneic host mice. Ten weeks after the injection the outgrowths were classified as ductal, nodule, tumor, or combinations of these types of outgrowths. The recovery of nodule outgrowths indicated the presence of nodule-transformed cells in the cell suspension that was injected. All donors yielded nodule outgrowths, and the percentage of outgrowths was significantly greater than was the percentage recovered from virgin BALB/cfC3H females of the same age groups. The latent period for the emergence of nodules and tumors was reduced from 8 to 9 months in virgin females to 4 months in parous females. The incidence of both nodules and tumors was greatly increased. The data suggest that parity significantly increases the numbers of nodule-transformed cells in donor tissue, decreases the time required for the emergence of nodules and tumors, and increases the number of overt nodules and tumors.
从5只4月龄初孕的晚期妊娠BALB/cfC3H雌性小鼠和5只6至7月龄经产的晚期妊娠雌性小鼠中回收了未显现结节转化的细胞。从每个供体取出乳腺组织，并用胶原酶（0.1%）、透明质酸酶（0.1%）和链霉蛋白酶（1.25%）进行解离。将0.01 ml培养基中100,000个活细胞的等分试样注射到3周龄同基因宿主小鼠无腺体的乳腺脂肪垫中。注射后10周，将长出物分类为导管型、结节型、肿瘤型或这些长出物类型的组合。结节长出物的回收表明注射的细胞悬液中存在结节转化细胞。所有供体都产生了结节长出物，并且长出物的百分比显著高于从相同年龄组的未孕BALB/cfC3H雌性小鼠中回收的百分比。未孕雌性小鼠中结节和肿瘤出现的潜伏期从8至9个月缩短至经产雌性小鼠中的4个月。结节和肿瘤的发生率均大大增加。数据表明，经产显著增加了供体组织中结节转化细胞的数量，减少了结节和肿瘤出现所需的时间，并增加了明显的结节和肿瘤的数量。
