Method for the validation of immunohistochemical staining using SCID mouse xenografts: expression of CD40 and CD154 in human non-small cell lung cancer

3D Tissue Microarray Controls: A Potential Standardization Solution

The use of controls is a hallmark for quality control in anatomic pathology. However, standardization of controls between laboratories has been a significant issue. Differential processing techniques between institutions and a multitude of preanalytical difficulties can result in different immunostain intensities. So called histoid controls, xenografts or culture cell lines, have been discussed in the past but with no recent followup. Herein is presented a histoid termed a 3D tissue microarray control (3D TMAC) control to help alleviate the burgeoning need for control standardization. A breast and cervix 3D TMAC control were tested for staining quality for 11 different antibodies commonly tested in either breast or cervical cancer work ups. We additionally looked at a small run of 5 days of CK5 and HER2 for reproducibility of the 3DRSTMA. Staining quality of 9 of the antibodies stained appropriately and 2 stained inappropriately, mammoglobin and GCDFP. Two of the antibodies were not reported to have any staining properties in the 3D TMAC, p16 and mammoglobin. Of these, p16 had appropriate staining and mammoglobin did not. In the 5 runs of CK5 and HER2, there was good reproducibility between stains assessed by both visual and computer-assisted methods, with membrane intensity coefficients of variation of 3.58% and 3.18%, respectively. The 3D TMAC has the potential to markedly improve intralaboratory and interlaboratory standardization practices.

Downregulated expression of human leukocyte antigen class I heavy chain is associated with poor prognosis in non-small-cell lung cancer

The aim of this study was to clarify the association between expression of human leukocyte antigen (HLA) class I in non-small-cell lung cancer (NSCLC) cells and patient survival. To address this, immunohistochemical staining for HLA class I was performed on specimens from 111 patients with NSCLC, and overall survival curves were compared using the log-rank test. In addition, multivariate analyses were performed using Cox's proportional hazard model. The cases were divided into 5 classes based on the expression of HLA class I heavy chain and β2-microglobulin. The overall survival rate for patients with tumors lacking HLA class I heavy chain (30 cases; 27.0%) was significantly decreased. The multivariate analysis demonstrated that the absence of HLA class I heavy chain was an independent predictor of poor prognosis. There was a trend towards an unfavorable prognosis for patients whose tumors did not express β2-microglobulin (57 cases; 51.4%). Downregulation of HLA class I heavy chain expression was significantly associated with the downregulation of β2-microglobulin. Cases lacking HLA class I heavy chain as well as β2-microglobulin expression (23 cases; 20.7%) had a statistically significant unfavorable prognosis compared with other cases. The present findings demonstrate that the lack of HLA class I heavy chain expression in tumor cells is an independent prognostic factor for poor NSCLC survival, and is likely to exert an important influence on immune surveillance in patients.

Prognostic value of MAGEA4 in primary lung cancer depends on subcellular localization and p53 status

Melanoma antigen family A4 (MAGEA4), a cancer/testis antigen, is overexpressed and is thus an immunotherapy target in various malignant tumors, including non-small cell lung cancer. However, whether MAGEA4 induces or inhibits the apoptosis of lung cancer cells remains controversial, as is its prognostic significance, particularly since there is no reliable method with which to detect MAGEA4 specifically. In this study, we optimized assay conditions to detect MAGEA4 based on cells transiently transfected with MAGEA genes, and found that MAGEA4 was expressed in four of eight non-small cell lung cancer cell lines, and in 25.4% of clinical lung cancer specimens. We also found that MAGEA4 overexpression decreased apoptosis, as measured by the levels of cleaved caspase-3 in stably transfected 293F cells. Notably, patients with nuclear MAGEA4, but not p53 expression exhibited a significantly poorer survival than those expressing both nuclear MAGEA4 and p53. Indeed, multivariate analysis identified nuclear MAGEA4 as an independent prognostic factor (P=0.0042), albeit only in the absence of p53. In this study, to the best of our knowledge, we are the first to demonstrate that the function and prognostic value of MAGEA4 depends on its subcellular localization and on the p53 status.

Antibodies That Work Again and Again and Again

In the past few years significant concern has been raised about the quality and reproducibility of antibodies used in numerous scientific publications. In this chapter we discuss some of the biggest contributing factors to the "antibody problem" from both the commercial production side, as well as the end-users side. Specifically we argue that Western blot data should be used to provide a reliable initial indication of antibody quality, as well as a guide to distinguish between multiple offerings for antibodies to the same target. Secondly, we describe a set of best practices for antibody manufacturers to employ that will eliminate most of the variability in polyclonal antibodies. Taken together these proposals provide a way to significantly improve both the quality and the reproducibility of commercial antibodies.

Standardization of negative controls in diagnostic immunohistochemistry: recommendations from the international ad hoc expert panel

Standardization of controls, both positive and negative controls, is needed for diagnostic immunohistochemistry (dIHC). The use of IHC-negative controls, irrespective of type, although well established, is not standardized. As such, the relevance and applicability of negative controls continues to challenge both pathologists and laboratory budgets. Despite the clear theoretical notion that appropriate controls serve to demonstrate the sensitivity and specificity of the dIHC test, it remains unclear which types of positive and negative controls are applicable and/or useful in day-to-day clinical practice. There is a perceived need to provide "best practice recommendations" for the use of negative controls. This perception is driven not only by logistics and cost issues, but also by increased pressure for accurate IHC testing, especially when IHC is performed for predictive markers, the number of which is rising as personalized medicine continues to develop. Herein, an international ad hoc expert panel reviews classification of negative controls relevant to clinical practice, proposes standard terminology for negative controls, considers the total evidence of IHC specificity that is available to pathologists, and develops a set of recommendations for the use of negative controls in dIHC based on "fit-for-use" principles.