The influence of matrix stiffness on the behavior of brain metastatic breast cancer cells in a biomimetic hyaluronic acid hydrogel platform

Abstract

Breast cancer brain metastasis marks the most advanced stage of breast cancer no longer considered curable with a median survival period of ∼4-16 months. Apart from the genetic susceptibility (subtype) of breast tumors, brain metastasis is also dictated by the biophysical/chemical interactions of tumor cells with native brain microenvironment, which remain obscure, primarily due to the lack of tunable biomimetic in vitro models. To address this need, we utilized a biomimetic hyaluronic acid (HA) hydrogel platform to elucidate the impact of matrix stiffness on the behavior of MDA-MB-231Br cells, a brain metastasizing variant of the triple negative breast cancer line MDA-MB-231. We prepared HA hydrogels of varying stiffness (0.2-4.5 kPa) bracketing the brain relevant stiffness range to recapitulate the biophysical cues provided by brain extracellular matrix. In this system, we observed that the MDA-MB-231Br cell adhesion, spreading, proliferation, and migration significantly increased with the hydrogel stiffness. We also demonstrated that the stiffness based responses of these cells were mediated, in part, through the focal adhesion kinase-phosphoinositide-3 kinase pathway. This biomimetic material system with tunable stiffness provides an ideal platform to further the understanding of mechanoregulation associated with brain metastatic breast cancer cells. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1832-1841, 2018.

BR-BCSC Signature: The Cancer Stem Cell Profile Enriched in Brain Metastases that Predicts a Worse Prognosis in Lymph Node-Positive Breast Cancer

“…In accordance, we also found a significant enrichment of the BCSC markers CD44, CD49f, P-cadherin, EpCAM, and ALDH1 in human breast cancer brain metastasis when compared with unmatched primary tumors previously analyzed by our group [34,41,42,51]. This clearly indicates that there is an imbalance of adhesion/stem cell molecules that lead to a modification in malignant and colonization properties in distant sites, such as the brain [18,[52][53][54][55][56][57]. However, more importantly, our study revealed an enriched stem cell profile defined by the simultaneous expression of 3-5 of these BCSC markers, which we defined as a BR-BCSC signature.…”

Three‐dimensional biomimetic hyaluronic acid hydrogels to investigate glioblastoma stem cell behaviors

“…After incubating at 37°C for approximately 30 min to form hydrogels, EMEM or Neurobasal‐A medium was added depending on the cell type and the medium was changed every day. For another experimental setup, integrin‐binding peptide (RGD; Anaspec) was presented to the cells in a matrix‐bound form by incorporating it into the HA methacrylate backbone through Michael‐type addition reaction as previously described (Ananthanarayanan et al, ; Narkhede et al, ). After functionalizing gel precursor solution with RGD for 3 hr, single glioblastoma cells were added to it and hydrogels were prepared similarly as described above.…”

“…HA was methacrylated adapting the procedure previously described (Ananthanarayanan, Kim, & Kumar, 2011;Narkhede, Crenshaw, Manning, & Rao, 2018). Briefly, 1 wt% HA of molecular weight 60 kDa (66-99 kDa; Lifecore Technologies) was subjected to a six-fold molar excess of methacrylic anhydride (Sigma Aldrich) while maintaining the pH above 8 throughout the reaction using 5 M NaOH solution at 4°C.…”

Extracellular Matrix Mimics Using Hyaluronan-Based Biomaterials

“…(C) Block copolymer micelle nanolithography (BCMN) with thiol-end HA (atomic force microscopy image of a glass surface covered with gold nanodots); and (D) microcontact printing with side-on immobilization of HA[99]. (E) 3D hydrogels for cell encapsulation, with tuned mechanical properties (varying the HA M w , the crosslinking degree, and/or the HA blended with other biocompatible materials)[58]. All the images were used and adapted, with permission, from[58,[97][98][99].…”

“…(E) 3D hydrogels for cell encapsulation, with tuned mechanical properties (varying the HA M w , the crosslinking degree, and/or the HA blended with other biocompatible materials)[58]. All the images were used and adapted, with permission, from[58,[97][98][99]. Abbreviations: LYVE, Lymphatic vessel endothelial receptor for hyaluronan; RHAMM, receptor for hyaluronan-mediated motility; TLR, toll-like receptor.…”