Abstract 989: Organoid cultures from normal and cancer-prone human breast tissues preserve complex epithelial lineages and can form chimeric mammary glands in vivo

Use of cell culture models to investigate the development of cancer associated with familial breast cancer syndromes is challenging because many culture methodologies do not maintain all of the lineages that are present in vivo, particularly the progenitor cells that may be the specific cancer cell-of-origin. We evaluated the ability of organoid culture technology to preserve stem/progenitor and differentiated cell types via long-term propagation of normal human mammary tissues. Tissue samples were obtained from elective reduction mammoplasties or from prophylactic mastectomies for cancer prevention, and were histologically normal. These were grown using conditions similar to organoid cultures for other epithelial cell types, as has been recently described (Sachs et al., Cell 2018). We found that basal stem and luminal progenitor cells could be cultured long-term, and differentiated in culture to generate mature basal and luminal cell types. Analysis of matched organoid cultures and native tissues by mass cytometry (CyTOF) for 38 markers at single-cell resolution confirmed the presence of multiple mammary epithelial cell types in the organoids, and demonstrated that protein expression patterns of the tissue of origin were largely preserved in culture. In addition, we generated a panel of over 40 mammary organoids derived from patients harboring inherited mutations in the cancer predisposition gene BRCA1 and from unaffected controls. Despite interindividual variability, an expansion in luminal progenitor populations associated with BRCA1 mutation could be detected in cultured organoids. Human mammary organoids heterozygous for BRCA1 could be engrafted into the murine mammary gland, resulting in mixed ductal and acinar structures. These studies indicate that this new model system is well suited for studies of aberrant phenotypes associated with BRCA1 mutation and approaches to prevent cancer development in these genetically predisposed tissues.

Citation Format: Jennifer M. Rosenbluth, Ronald Schackmann, Carman Li, Norman Sachs, Deborah Dillon, Andrea Richardson, Jane Brock, Judy Garber, Gary Kenneth Gray, Jason Zoeller, Mackenzie Boedicker, Hendrick Johannes Kuiken, Hans Clevers, Joan Brugge. Organoid cultures from normal and cancer-prone human breast tissues preserve complex epithelial lineages and can form chimeric mammary glands in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 989.

[Establishing a quality management system according to DIN EN ISO 9001:2000 in an academic radiological department]

PURPOSE

Establishing a quality management (QM) system according the guidelines of DIN EN ISO 9001:2000 in an academic radiological department.

MATERIALS AND METHODS

To fulfill the requirements of an academic radiological department a quality management system according the guidelines of DIN EN ISO 9001 : 2000 has been established within one year. All important educational, research and patient care issues have been discussed in plenary sessions of all employees of the department twice a week. All core processes of the department have been documented as process instructions and standard operation procedures.

RESULTS

Supported by the staff unit "quality assurance" of the university hospital, the QM system has been established during one year. Assisted by all parties of the department, obliging regulations have been established which are well accepted in the daily routine clinical work but also in research and education. The implementation of the QM system caused an additional work load. However, spreading the work load by a consequent responsibility assignment, it could be reduced effectively.

CONCLUSION

The implementation of a QM system within the daily routine work of an academic radiological department is feasible. It allows the installation of generally accepted rules which regulate the principal tasks of research and education, and patient care.

Cation transport by gastric H+:K+ ATPase

A vesicular microsomal fraction isolated from hog fundic mucosa demonstrates the capacity to take up equal amounts of RB+ and Cl-. The amount of the Rb+ uptake is sensitive to the extravesicular osmolarity, and rate of uptake is sensitive to temperature. 86Rb+ efflux is dependent upon the cation composition of the diluting solution. ATP, but not beta-gamma methylene ATP, induces a reversible efflux of 86Rb+ from loaded vesicles, and this is dependent upon a functional K+-ATPase. The ATP induced efflux is not affected by CCCP (carbonyl cyanide m-chlorophenylhydrazone) or TCS (tetrachlorosalicylanilide) nor by lipid soluble ions or valinomycin. Nigericin inhibits the efflux by 40%. Uptake of the lipid soluble ion 14C-SCN- has been demonstrated and is enhanced by ATP only in the presence of valinomycin. The results are consistent with a neutral or isopotential exchange of H+ for Rb+ mediated by K+-ATPase.

Use of 1-anilino-8-naphthalene-sulfonate as a probe of gastric vesicle transport

The interaction of 1-anilino-8-naphthalene-sulfonate (ANS) with vesicles derived from hog fundic mucosa was studied in the presence of valinomycin and with the addition of ATP. Evidence was found for two classes of sites, those rapidly accessible to ANS with a KD of 7.5 micronM and those slowly accessible, but rapidly accessed in the presence of valinomycin with a KD of 2.5 micronM. ATP transiently increases the quantum yield of the latter ANS binding sites only in the presence of valinomycin, but does not alter the number of KD of those sites. The time course of this increase correlates with H+ uptake and Rb+ extrusion by those vesicles and H+ carries such as tetrachlorsalicylanilide or nigericin abolish the ATP response. With ATP addition in the presence of SC14N and valinomycin there is transient uptake of SCN-. It is concluded that ANS is acting as a probe of a structural change dependent on a potential and H+ gradient.

Proton transport by gastric membrane vesicles

A highly purified membrane fraction was derived from hog gastric mucosa by a combination of differential and density gradient centrifugation and free flow electrophoresis. This final fraction was 35-fold enriched with respect to cation activated ouabain-insensitive ATPase. Antibody against this fraction was shown to be bound to the luminal surface of the gastric glands. The addition of ATP to this fraction or the density gradient fraction resulted in H+ uptake into an osmotically sensitive space. The apparent Km for ATP was 1.7-10(-4) M in the absence of a K+ gradient similar to that found for ATPase activity. The reaction is specific for ATP and requires cation in the sequence K+ greater than Rb+ greater than Cs+ greater than Na+ greater than Li+ and inhibited by ATPase inhibitors such as N,N'-dicylclohexyl-carbodiimide. Maximal H+ uptake occurs with an outward K+ gradient but the minimal apparent KA is found in the absence of a K+ gradient. The pH optimum for H+ uptake is between 5.8 and 6.2 which corresponds to the pH range for phosphroylation of the enzyme, but is considerably less than the pH maximum of the K+ dependent dephosphorylation. In the presence of an inward K+ gradient, protonophores such as tetrachlorsalicylanilide only partially abolish the H+ gradient but valinomycin dissipates 75% of the gradient, and nigericin abolishes the gradient. The vesicles therefore have a low K+ conductance but a measurable H+ conductance, hence a K+ gradient can produce an H+ gradient in the presence of valinomycin. The uptake and spontaneous leak of H+ are temperature sensitive with a similar transition temperature. Ultraviolet irradiation inactivates ATPase and proton transport at the same rate, approximately at twice the rate of p-nitrophenylphosphatase inactivation. It is concluded that H+ uptake by these vesicles is probably due to a dimeric (H+ + K+)-ATPase and is probably non-electrogenic.