A fast, simple, and cost-effective method of expanding patient-derived xenograft mouse models of pancreatic ductal adenocarcinoma.

BACKGROUND: Patient-derived xenograft (PDX) mouse models of cancer have been recognized as better mouse models that recapitulate the characteristics of original malignancies including preserved tumor heterogeneity, lineage hierarchy, and tumor microenvironment. However, common challenges of PDX models are the significant time required for tumor expansion, reduced tumor take rates, and higher costs. Here, we describe a fast, simple, and cost-effective method of expanding PDX of pancreatic ductal adenocarcinoma (PDAC) in mice. METHODS: We used two established frozen PDAC PDX tissues (derived from two different patients) and implanted them subcutaneously into SCID mice. After tissues reached 10-20 mm in diameter, we performed survival surgery on each mouse to harvest 90-95% of subcutaneous PDX (incomplete resection), allowing the remaining 5-10% of PDX to continue growing in the same mouse. RESULTS: We expanded three consecutive passages (P1, P2, and P3) of PDX in the same mouse. Comparing the times required for in vivo expansion, P2 and P3 (expanded through incomplete resection) grew 26-60% faster than P1. Moreover, such expanded PDX tissues were successfully implanted orthotopically into mouse pancreases. Within 20 weeks using only 14 mice, we generated sufficient PDX tissue for future implantation of 200 mice. Our histology study confirmed that the morphologies of cancer cells and stromal structures were similar across all three passages of subcutaneous PDX and the orthotopic PDX and were reflective of the original patient tumors. CONCLUSIONS: Taking advantage of incomplete resection of tumors associated with high local recurrence, we established a fast method of PDAC PDX expansion in mice.

Novel ANO5 mutation c.1067G>T (p.C356F) identified by whole genome sequencing in a big family with atypical gnathodiaphyseal dysplasia.

BACKGROUND: Gnathodiaphyseal dysplasia (GDD) is a rare skeletal disorder that has not been well studied. METHODS: Sanger sequencing, whole-genome sequencing (WGS), and bioinformatics and structural modeling analyses were performed. RESULTS: A family with patients with fibro-osseous lesions of the jawbones were initially diagnosed with cherubism. Sequencing of SH3BP2, which is the causal gene of cherubism, revealed no pathogenic mutation. Through WGS, we identified a novel mutation c.1067G>T (p.C356F) in ANO5, and bioinformatics analyses and structural modeling showed that the mutation was deleterious. Because ANO5 is the gene responsible for GDD, we reappraised the clinical data of the patients, and the diagnosis was corrected to atypical GDD. A review of the literature showed that 67% of GDD cases confirmed by molecular testing were initially misdiagnosed. CONCLUSIONS: The novel mutation c.1067G>T (p.C356F) in ANO5 is responsible for the atypical GDD observed in our patients. GDD should be included in the differential diagnosis for patients with fibro-osseous lesions.

"Five-point eight-line" anatomic flap design for precise hemitongue reconstruction.

BACKGROUND: Reconstruction of hemiglossectomy defects requires careful flap design to avoid adverse functional and aesthetic outcomes. METHODS: Hemitongue specimens were obtained from minipigs to study the three-dimensional anatomy and to define anatomic landmarks for precise measurements of flap requirement. The concept developed in animal models was then applied to hemiglossectomy reconstruction in clinical practice. Sixty-one patients were randomly enrolled into the following two groups: a "five-point eight-line segment" (FIPELS) flap design group (28 patients) and a conventional group (33 patients). Functional and aesthetic outcomes were compared between the two groups. RESULTS: All flaps designed with the FIPELS technique matched the hemiglossectomy defects without the need for flap trimming, thus reducing the operating time (P = .03). Swallowing functions, speech intelligibility, and aesthetic outcomes were superior in the FIPELS group than that in the conventional group (P < .05). CONCLUSIONS: The FIPELS flap design for hemiglossectomy reconstruction yields improved functional and aesthetic outcomes compared to a conventional flap design.