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Context.--Nasopharyngeal carcinoma (NPC), common in southern China and North Africa, has a complex etiology involving interplay between viral, environmental, and hereditary factors and is almost constantly associated with the Epstein-Barr virus. Since the prognosis of locally advanced and metastatic diseases is poor, increased understanding of the pathogenesis of NPC would be important for discovering novel markers for patients' management. Objectives.--To compare the proteomic expression profile between an Epstein-Barr virus-associated NPC cell line (C666-1) and a normal NP cell line (NP69). The proteins with differential expression were analyzed in 40 undifferentiated NPC paraffin-embedded specimens. Design.--Differentially expressed proteins discovered between the two cell lines were identified by mass spectrometry. After confirmation by immunocytochemical staining, their expression in patient samples was measured using 40 pairs of undifferentiated NPCs together with their adjacent normal epithelia. Results.--Proteomic findings indicated that adenosine triphosphate synthase [alpha] chain was up-regulated, whereas annexin II, annexin V, [[beta].sub.2]-tubulin, and profilin 1 were down-regulated. After confirming the results in agar-processed cell lines, annexin II and [[beta].sub.2]-tubulin expression were found to be lower in tumor cells than in adjacent normal epithelial cells in 100% and 90% of the patients' specimens, respectively. Finally, annexin II down-regulation was positively associated with lymph node metastasis, suggesting that it may be a prognostic factor in NPC. Conclusions.--The results suggest that annexin II and [[beta].sub.2]-tubulin down-regulation is important in NPC formation and may represent potential targets for further investigations., (Arch Pathol Lab Med. 2008;132:675-683) Nasopharyngeal carcinoma (NPC) is endemic in southern China, Southeast Asia, and North Africa, but it is rare in most parts of the world. (1) The [...]

* Context.--In immunohistochemistry, nonstandardized antigen retrieval protocols and fluids, poor-quality antibodies, and the presence of endogenous biotin frequently lead to incorrect results. Recently, advanced reagents including bifunctional SkipDewax pretreatment solution (BSPS), rabbit monoclonal (RM) antibodies, and biotin-free polymer detection systems (PDSs) have been developed, which, it is claimed, resolve these problems. Objectives.--To determine whether BSPS, RM antibodies, and biotin-free PDSs improve the accuracy of immunohistochemistry; to optimize a new protocol consisting of a combination of BSPS, RM antibodies, and PDSs; and to compare it with a conventional protocol. Design.--The efficacies of BSPS, RM antibodies, and PDSs were compared with those of their respective conventional reagents using multitissue spring-roll sections. The new protocol was compared with a conventional protocol using Ki-67 immunostaining of 49 colorectal carcinoma specimens. Results.--For antigen retrieval, BSPS resulted in similar or better tissue staining than an EDTA solution, but the efficacy of BSPS decreased when it was reused. Most RM antibodies resulted in a greater proportion of positive cells than the corresponding non-RM antibodies, which did not produce satisfactory results in the absence of antigen retrieval. The PDSs Bond, ChemMate, and SuperPicture resulted in a high percentage of positive cells, good staining intensities, and low backgrounds. Other PDSs, except that from Ventana, resulted in high backgrounds and false positivity. The new combined protocol resulted in better Ki-67 staining than the conventional assay. Conclusions.--Bifunctional SkipDewax pretreatment solution, RM antibodies, and PDSs improve staining quality and diagnostic accuracy of immunohistochemistry assays and provide a foundation for standardization., Immunohistochemistry (IHC) has revolutionized the practice of surgical pathology by providing accurate information for patient diagnosis, prognosis, and even therapy. (1) The success of IHC can be attributed to improvements [...]