Lance Amanda, Yang Chih-Chao, Swamydas Muthulekha, Dean Delphine, Deitch Sandy, Burg Karen J L, Dréau Didier
Cell and Molecular Division, Department of Biology, University of North Carolina, Charlotte, NC, USA.
Department of Bioengineering, Clemson University, SC, USA.
J Tissue Eng Regen Med. 2016 Jan;10(1):71-80. doi: 10.1002/term.1675. Epub 2013 Feb 12.
The extracellular matrix (ECM) contributes to the generation and dynamic of normal breast tissue, in particular to the generation of polarized acinar and ductal structures. In vitro 3D culture conditions, including variations in the composition of the ECM, have been shown to directly influence the formation and organization of acinus-like and duct-like structures. Furthermore, the density of the ECM appears to also play a role in the normal mammary tissue and tumour formation. Here we show that the density of the ECM directly influences the number, organization and function of breast acini. Briefly, non-malignant human breast MCF10A cells were incubated in increasing densities of a Matrigel®-collagen I matrix. Elastic moduli near and distant to the acinus structures were measured by atomic force microscopy, and the number of acinus structures was determined. Immunochemistry was used to investigate the expression levels of E-cadherin, laminin, matrix metalloproteinase-14 and ß-casein in MCF10A cells. The modulus of the ECM was significantly increased near the acinus structures and the number of acinus structures decreased with the increase in Matrigel-collagen I density. As evaluated by the expression of laminin, the organization of the acinus structures present was altered as the density of the ECM increased. Increases in both E-cadherin and MMP14 expression by MCF10A cells as ECM density increased were also observed. In contrast, MCF10A cells expressed lower ß-casein levels as the ECM density increased. Taken together, these observations highlight the key role of ECM density in modulating the number, organization and function of breast acini.
细胞外基质（ECM）有助于正常乳腺组织的生成和动态变化，特别是对极化腺泡和导管结构的生成。体外三维培养条件，包括ECM组成的变化，已被证明可直接影响腺泡样和导管样结构的形成与组织。此外，ECM的密度似乎在正常乳腺组织和肿瘤形成中也发挥作用。在此，我们表明ECM的密度直接影响乳腺腺泡的数量、组织和功能。简而言之，将非恶性人乳腺MCF10A细胞培养于密度不断增加的基质胶 - Ⅰ型胶原基质中。通过原子力显微镜测量腺泡结构附近和远处的弹性模量，并确定腺泡结构的数量。采用免疫化学方法研究MCF10A细胞中E - 钙黏蛋白、层粘连蛋白、基质金属蛋白酶 - 14和β - 酪蛋白的表达水平。腺泡结构附近的ECM模量显著增加，且随着基质胶 - Ⅰ型胶原密度的增加，腺泡结构的数量减少。通过层粘连蛋白的表达评估，随着ECM密度的增加，现存腺泡结构的组织发生改变。还观察到随着ECM密度增加，MCF10A细胞中E - 钙黏蛋白和MMP14的表达均增加。相反，随着ECM密度增加，MCF10A细胞中β - 酪蛋白水平降低。综上所述，这些观察结果突出了ECM密度在调节乳腺腺泡数量、组织和功能方面的关键作用。
