The use of mouse models of breast cancer and quantitative image analysis to evaluate hormone receptor antigenicity after microwave-assisted formalin fixation

Fundamental Concepts for Semiquantitative Tissue Scoring in Translational Research

Failure to reproduce results from some scientific studies has raised awareness of the critical need for reproducibility in translational studies. Macroscopic and microscopic examination is a common approach to determine changes in tissues, but text descriptions and visual images have limitations for group comparisons. Semiquantitative scoring is a way of transforming qualitative tissue data into numerical data that allow more robust group comparisons. Semiquantitative scoring has broad uses in preclinical and clinical studies for evaluation of tissue lesions. Reproducibility can be improved by constraining bias through appropriate experimental design, randomization of tissues, effective use of multidisciplinary collaborations, and valid masking procedures. Scoring can be applied to tissue lesions (eg, size, distribution, characteristics) and also to tissues through evaluation of staining distribution and intensity. Semiquantitative scores should be validated to demonstrate relevance to biological data and to demonstrate observer reproducibility. Statistical analysis should make use of appropriate tests to give robust confidence in the results and interpretations. Following key principles of semiquantitative scoring will not only enhance descriptive tissue evaluation but also improve quality, reproducibility, and rigor of tissue studies.

A Syngeneic ErbB2 Mammary Cancer Model for Preclinical Immunotherapy Trials

In order to develop a practical model of breast cancer, with in vitro and syngeneic, immune-intact, in vivo growth capacity, we established a primary cell line derived from a mammary carcinoma in the transgenic FVB/N-Tg(MMTV-ErbB2*)NDL2-5Mul mouse, referred to as "NDL^UCD". The cell line is adapted to standard cell culture and can be transplanted into syngeneic FVB/N mice. The line maintains a stable phenotype over multiple in vitro passages and rounds of in vivo transplantation. NDL^UCD tumors in FVB/N mice exhibit high expression of ErbB2 and ErbB3 and signaling molecules downstream of ErbB2. The syngeneic transplant tumors elicit an immune reaction in the adjacent stroma, detected and characterized using histology, immunophenotyping, and gene expression. NDL^UCD cells also express PD-L1 in vivo and in vitro, and in vivo transplants are reactive to anti-immune checkpoint therapy with responses conducive to immunotherapy studies. This new NDL^UCD cell line model is a practical alternative to the more commonly used 4T1 cells, and our previously described FVB/N-Tg(MMTV-PyVT)634Mul derived Met-1^fvb2 and FVB/NTg(MMTV-PyVT^Y315F/Y322F) derived DB-7^fvb2 cell lines. The NDL^UCD cells have, so far, remained genetically and phenotypically stable over many generations, with consistent and reproducible results in immune intact preclinical cohorts.

Principles and approaches for reproducible scoring of tissue stains in research

Evaluation of tissues is a common and important aspect of translational research studies. Labeling techniques such as immunohistochemistry can stain cells/tissues to enhance identification of specific cell types, cellular activation states, and protein expression. While qualitative evaluation of labeled tissues has merit, use of semiquantitative and quantitative scoring approaches can greatly enhance the rigor of the tissue data. Adhering to key principles for reproducible scoring can enhance the quality and reproducibility of the tissue data so as to maximize its biological relevance and scientific impact.

Elevated Foxp3/CD8 Ratio in Lung Adenocarcinoma Metastatic Lymph Nodes Resected by Transcervical Extended Mediastinal Lymphadenectomy

A balance between tumor invasion and immune defence system is widely investigated. Objective. The aim of this study was to evaluate lymphocyte phenotype in lymph nodes (LNs) of patients with lung cancer in relation to the presence of metastases. Methods. We investigated 364 LNs resected by transcervical extended mediastinal lymphadenectomy (TEMLA) of 49 patients with squamous cell carcinoma (SCC) or adenocarcinoma (AD) with (A) and without metastases (B). Expression of CD4, CD8, CD25, CTLA-4, and Foxp3 was assessed by immunohistochemical staining. Results. We observed a strong nuclear staining for Foxp3 in lymphocytes and cancer cells and strong membranous/cytoplasmatic reaction for CD4 and CD8, but low for CD25 and CTLA-4. There were significantly higher proportions of CD8+ cells in AD (B) versus AD (A) LNs (80% versus 52.5%, p < 0.05). The Foxp3/CD8 ratio was higher in AD (A) versus AD (B) LNs (0.4 versus 0.25, p < 0.05). No significant differences in the cell markers expression in SCC LNs were found. Conclusion. Significant differences in lymphocyte phenotype in AD may indicate an exceptional biology of this type of lung cancer. TEMLA resected LNs may serve as valuable samples for evaluation of immune status in lung cancer patients.