Fibroblasts drive an immunosuppressive and growth-promoting microenvironment in breast cancer via secretion of Chitinase 3-like 1

Cancer-Associated Fibroblasts (CAFs) are the most prominent stromal cell type in breast tumors. CAFs promote tumor growth and metastasis by multiple mechanisms, including by mediating tumor-promoting inflammation. Immune modulation in the tumor microenvironment plays a central role in determining disease outcome. However, the functional interactions of CAFs with immune cells are largely unknown. Here we report a novel signaling axis between fibroblasts, cancer cells and immune cells in breast tumors that drives an immunosuppressive microenvironment, mediated by CAF-derived Chi3L1. We demonstrate that Chi3L1 is highly upregulated in CAFs isolated from mammary tumors and pulmonary metastases of transgenic mice, and in the stroma of human breast carcinomas. Genetic ablation of Chi3L1 in fibroblasts in vivo attenuated tumor growth, macrophage recruitment and reprogramming to an M2-like phenotype, enhanced tumor infiltration by CD8⁺ and CD4⁺ T cells and promoted a Th1 phenotype. These results indicate that CAF-derived Chi3L1 promotes tumor growth and shifts the balance of the immune milieu towards type 2 immunity. Taken together, our findings implicate fibroblast-derived Chi3L1 as a novel key player in the complex reciprocal interactions of stromal cells that facilitate tumor progression and metastasis, and suggest that targeting Chi3L1 may be clinically beneficial in breast cancer.

Near-field optical photomask repair with a femtosecond laser

We present a high-resolution near-field optical tool designed for repair of opaque defects in binary photomasks. Both instrument design and near-field imaging and patterning results will be presented. Designed for ablative processing of thin metal films, the MR-100 incorporates an industrial amplified femtosecond laser, third harmonic generator and built-in autocorrelator. The ultrashort duration of the femtosecond pulses enables the tool to remove chrome layers with negligible damage to the surrounding metal or the underlying quartz substrate. The micropipette based near-field writing head can deliver power densities of hundreds of GW/cm2 to spots of several hundred nanometres and below. Repairs on sample masks will be presented and the repair quality will be discussed.

Human endometrium in cell culture: a new method for culturing human endometrium as separate epithelial and stromal components

The present study describes a simple method for culturing human endometrium as separate epithelial and stromal components. Fifty-two samples of normal human endometrium have been initiated in tissue culture: endometrium from both the proliferative and luteal phases of the menstrual cycle showed satisfactory growth in vitro with a success rate of about 94%. Epithelial cultures remained viable for 60 days, while from stromal cells it was possible to establish cell lines. Both cell types possessed estrogen receptors. Epithelial cells showed no clear estrogen or progesterone response. Our observations suggest that this simple method for culturing human endometrium may serve as a tool in further investigations.