Wnt suppressor and stem cell regulator TCF7L1 is a sensitive immunohistochemical marker to differentiate testicular seminoma from non-seminomatous germ cell tumor.

The accurate classification and proper identification of testicular germ cell tumors is imperative for treatment selection and clinical prognosis. Although such distinction can often be achieved by microscopic morphology alone, ancillary tests may at times be needed. T-cell factor 7 L1 (TCF7L1, also known as TCF3), a component of the Wnt signaling pathway, plays important roles in embryonic stem cell self-renewal and lineage specification. Here we examined the immunohistochemical expression and diagnostic utility of TCF7L1 in testicular germ cell tumors. Fifty cases of testicular germ cell tumors were collected, including 23 seminomas, 6 embryonal carcinomas, 1 teratoma, 1 choriocarcinoma, and 19 mixed germ cell tumors. The components of the mixed germ cell tumors were seminoma (n = 3), embryonal carcinoma (n = 18), yolk sac tumor (n = 9), teratoma (n = 15), and choriocarcinoma (n = 4). On immunohistochemistry of TCF7L1, only nuclear staining was considered positive. Staining was graded as negative (<5% of tumor cells stained), minimal (5-25% positive), focal (26-50%), and diffuse (>50%). All non-seminomatous components (n = 54) exhibited distinct nuclear expression of TCF7L1 (54/54; 100%). In contrast, no TCF7L1 expression was detected in the majority of seminomatous tumor component (24/26; 92%). Two seminomas (2/26; 8%) exhibited minimal weak nuclear staining (5% and 10%, respectively) for TCF7L1. In conclusion, TCF7L1, highly expressed in non-seminomatous testicular germ cell tumors, might be used as a marker for diagnosis of testicular germ cell tumors, two therapeutically different entities, for better patient management.

A novel detection methodology for HER2 protein quantitation in formalin-fixed, paraffin embedded clinical samples using fluorescent nanoparticles: an analytical and clinical validation study.

BACKGROUND: Clinical assays for the assessment of the human epidermal growth factor receptor-2 (HER2) status in breast cancer include immunohistochemistry (IHC) and in situ hybridization (ISH), both of which have limitations. Recent studies have suggested that a more quantitative approach to the measurement of HER2 protein expression may improve specificity in selecting patients for HER-2 targeted therapy. In the current study, we have used HER2 expression in breast cancer cell lines and clinical samples as a model to explore the potential utility of a novel immunodetection technique, using streptavidin coated Phosphor Integrated Dot fluorescent nanoparticles (PID), which can be quantitatively measured using computer analysis. METHODS: The expression of HER2 protein in cell lines was evaluated with antibody-binding capacity using fluorescence-activated cell sorting (FACS) for comparison with PID measurements to test for correlations with existing quantitative protein analysis methodologies. Various other analytic validation tests were also performed, including accuracy, precision, sensitivity, robustness and reproducibility. A methods comparison study investigated correlations between PID versus IHC and ISH in clinical samples. Lastly, we measured HER2 protein expression using PID in the pretreatment biopsies from 34 HER2-positive carcinomas that had undergone neoadjuvant trastuzumab-based chemotherapy. RESULTS: In the analytic validation, PID HER2 measurements showed a strong linear correlation with FACS analysis in breast cell lines, and demonstrated significant correlations with all aspects of precision, sensitivity, robustness and reproducibility. PID also showed strong correlations with conventional HER2 testing methodologies (IHC and ISH). In the neoadjuvant study, patients with a pathologic complete response (pCR) had a significantly higher PID score compared with patients who did not achieve a pCR (p = 0.011), and was significantly correlated to residual cancer burden (RCB) class (p = 0.026, R2 = 0.9975). CONCLUSIONS: Analytic testing of PID showed that it may be a viable testing methodology that could offer advantages over other experimental or conventional biomarker diagnostic methodologies. Our data also suggests that PID quantitation of HER2 protein may offer an improvement over conventional HER2 testing in the selection of patients who will be the most likely to benefit from HER2-targeted therapy. Further studies with a larger cohort are warranted.

ZBTB16: a novel sensitive and specific biomarker for yolk sac tumor.

Although the function of zinc finger and BTB domain containing 16 (ZBTB16) in spermatogenesis is well documented, expression of ZBTB16 in germ cell tumors has not yet been studied. The aim of this study was to investigate the immunohistochemical expression and diagnostic utility of ZBTB16 in germ cell tumors. A total of 67 adult germ cell tumors were studied (62 testicular germ cell tumors, 2 ovarian yolk sac tumors, 1 mediastinal yolk sac tumor, and 2 retroperitoneal metastatic yolk sac tumors). The 62 testicular primary germ cell tumors are as follows: 34 pure germ cell tumors (20 seminomas, 8 embryonal carcinomas, 2 teratomas, 1 choriocarcinoma, 1 carcinoid, and 2 spermatocytic tumors) and 28 mixed germ cell tumors (composed of 13 embryonal carcinomas, 15 yolk sac tumors, 15 teratomas, 7 seminomas, and 3 choriocarcinomas in various combinations). Thirty-five cases contained germ cell neoplasia in situ. Yolk sac tumor was consistently reactive for ZBTB16. Among the 15 testicular yolk sac tumors in mixed germ cell tumors, all displayed moderate to diffuse ZBTB16 staining. ZBTB16 reactivity was present regardless of the histologic patterns of yolk sac tumor and ZBTB16 was able to pick up small foci of yolk sac tumor intermixed/embedded in other germ cell tumor subtype elements. Diffuse ZBTB16 immunoreactivity was also observed in 2/2 metastatic yolk sac tumors, 1/1 mediastinal yolk sac tumor, 2/2 ovarian yolk sac tumors, 2/2 spermatocytic tumors, 1/1 carcinoid, and the spermatogonial cells. All the other non-yolk sac germ cell tumors were nonreactive, including seminoma (n=27), embryonal carcinoma (n=21), teratoma (n=17), choriocarcinoma (n=4), and germ cell neoplasia in situ (n=35). The sensitivity and specificity of ZBTB16 in detecting yolk sac tumor among the germ cell tumors was 100% (20/20) and 96% (66/69), respectively. In conclusion, ZBTB16 is a highly sensitive and specific marker for yolk sac tumor.

A lower Allred score for progesterone receptor is strongly associated with a higher recurrence score of 21-gene assay in breast cancer.

Among the 77 infiltrating breast carcinomas, we found that progesterone receptor (PR) expression was inversely associated with recurrence score (RS, p < .0001). RS is also significantly associated with tubule formation, mitosis, and luminal B subtype. The equation of RS = 17.489 + 2.071 (tubal formation) + 2.926 (mitosis) -2.408 (PR) -1.061 (HER2) + 7.051 (luminal A) + 29.172 (luminal B) predicts RS with an R² of 0.65. In conclusion, PR negativity, luminal B subtype, tubal formation, and mitosis are strongly correlated with a higher RS.

Gastrin Staining in Inflamed Stomach Biopsies Labeled as "Antral" Rarely Detects Atrophic Gastritis.

OBJECTIVES: Autoimmune metaplastic atrophic gastritis (AMAG) is an underrecognized entity, especially in its early stage. This study assessed whether the use of gastrin immunohistochemistry would increase sensitivity for diagnosing early AMAG. METHODS: Three-hundred gastric biopsies were prospectively stained for gastrin by immunohistochemistry. Inclusion criteria included well-oriented gastric mucosa with mucus glands and minimal plasma cell infiltrate not suspected to represent pyloric metaplasia. Patient age, sex, designated location of biopsy, presence or absence of intestinal metaplasia, and clinical information were not criteria. Any case with absence of gastrin-positive endocrine cells reflexed to chromogranin immunohistochemistry. Maloriented biopsies or cases with current Helicobacter infection were excluded. RESULTS: The 298-patient study cohort comprised 222 females (mean age, 47 years; range, 16-80 years) and 76 males (mean age, 49 years; range, 7-80 years). Biopsies were designated as "antral/antral nodules" (61%), and the rest were labeled "gastric/random stomach" (39%). Nine cases (3%) exhibited absence of gastrin-positive endocrine cells; one of those showed endocrine cell hyperplasia by chromogranin staining. CONCLUSIONS: Pathologists should be aware of the histologic features of early AMAG and meticulously analyze tissue regardless of specimen labeling. Gastrin immunostain is a supplemental diagnostic tool when encountering inflamed antral-appearing specimens.

Diagnostic utility of IMP3 in segregating metastatic melanoma from benign nevi in lymph nodes.

Depending on the Breslow depth of the primary melanoma, sentinel lymph node biopsy is considered as standard of care for the staging of cutaneous melanoma, and is one of the most important prognostic factors. The histologic analysis of these specimens becomes difficult to interpret when benign intranodal nevic cells mimic metastases. Insulin-like growth factor-II messenger RNA (mRNA)-binding protein-3 (IMP3), also known as K homology domain-containing protein overexpressed in cancer or L523S, is a member of the insulin-like growth factor-II mRNA-binding protein family and has been shown to have diagnostic utility in distinguishing cutaneous melanoma from benign nevi. In this study, 43 sentinel lymph node biopsy specimens, including 13 with benign intranodal nevi and 30 with metastatic melanoma (two cases containing both benign nevi and metastatic melanoma), from 41 patients were immunohistochemically analyzed with a monoclonal antibody against IMP3. None of the benign intranodal nevi expressed IMP3, whereas 21 out of 30 (70%) of the lymph nodes containing metastatic melanoma did. It seems that IMP3 is helpful in distinguishing benign intranodal nevi from metastatic melanoma in sentinel lymph node biopsy specimens, and could be a valuable diagnostic adjunct in sentinel lymph node biopsy assessment in which questions arise as to the malignancy of the melanocytes present.

Impact of Specimen Type and Specimen Number on HER2 Status in Gastroesophageal Junction and Gastric Adenocarcinoma.

OBJECTIVES: Human epidermal growth factor receptor 2 (HER2) is expressed in some gastric and gastroesophageal junction adenocarcinomas. There were two goals: assess the impact of specimen type on HER2 status and evaluate HER2 concordance with multiple specimens. METHODS: All cases were evaluated by immunohistochemistry (IHC) for HER2 and interpreted using established criteria. Fluorescence in situ hybridization (FISH) was performed on a subset. RESULTS: Of 460 specimens, 83.9% were IHC negative, 5.4% were equivocal, and 10.7% were IHC positive. Of those with FISH testing, 78.5% were FISH negative, and 21.5% were FISH positive. IHC-FISH concordance for biopsy specimens, resections, and metastases was 82%, 84%, and 86%, respectively. With one vs two vs three or more specimens, the HER2-positive rate increased from 10.5% to 18.1% to 24.1%, respectively. CONCLUSIONS: HER2 testing may be performed on biopsy specimens with a relatively high concordance rate with resection specimens, and if multiple samples are analyzed from a single patient, the HER2-positive rate increases over twofold.

IMP3 Immunohistochemical Expression Remains Consistent Among All Grades of Gastrointestinal Neuroendocrine Tumors.

Insulin-like growth factor-II messenger RNA-binding protein-3 (IMP3), is an oncofetal protein whose aberrant expression has previously been detected in multiple malignant neoplasms. Pulmonary neuroendocrine carcinomas demonstrate increased expression compared with pulmonary carcinoid tumors, but this relationship has not been studied in gastrointestinal neuroendocrine tumors (GINETs). This study examined IMP3 expression in GINETs, with a focus on correlation with established grading criteria. Fifty-four GINETs were immunohistochemically studied using a monoclonal antibody against IMP3. Using established World Health Organization criteria, the cases were stratified by grade and included 31 grade 1 neuroendocrine tumors (G1 GINETs), 15 grade 2 neuroendocrine tumors (G2 GINETs), and 8 neuroendocrine carcinomas (GINECs). The majority (51/54, 94.4%) of GINETs demonstrated IMP3 staining. Thirty cases (55.6%) showed IMP3 cytoplasmic/membranous staining in 60% or greater of tumor cells, with moderate to strong staining in nearly all of these cases (29/30; 96.7%). Of the remaining 24 cases, 3 cases showed no staining, whereas 17 (81%) demonstrated weak staining. When stratified by grade, there was no statistically significant difference in IMP3 staining among the 3 grades of GINETs; of the G1 GINETs, 14 (45.2%) demonstrated staining in at least 60% of tumor cells, compared with 10 (66.7%) G2 GINETs and 6 (75%) GINECs. Hindgut neoplasms of any grade were the most likely to show significant IMP3 staining. Unlike what has been demonstrated in neuroendocrine neoplasms in the lungs, GINETs appear to have a consistent IMP3 expression profile among all tumors grades, which may be reflective of their unique tumor biology.

Chorionic Histiocytic Hyperplasia is Associated With Chronic Inflammatory Lesions in the Placenta.

Background Chorionic histiocytic hyperplasia (CHH) is a cellular proliferation at the base of the chorion that was identified by the authors in examining placentas for chronic chorioamnionitis (CC). This study is a retrospective review of cases diagnosed with CHH, describing its incidence alone and with associated lesions, and the immunophenotype of lesional cells. Design In this retrospective study, a laboratory information system search over a 34-month period using the key phrase "chorionic stromal" was performed. Cases identified were reviewed for presence of the following: CC, chronic villitis (CV), chronic deciduitis (CD), maternal (MIR), and fetal (FIR) acute inflammatory responses, meconium deposition; and whether CD3 immunostaining was performed. Incidences were tabulated and compared with known prevalences in our population. Select cases were stained with various immunostains to identify cell lineage and X and Y fluorescent probes to identify fetal or maternal cell origin in cases with male infants. Results Eighty cases of CHH were identified during the study period. Incidences of inflammatory lesions associated with CHH were: CV (54/80, 68%), CD (32/80, 40%), CC (25/80, 31%), MIR (39/80, 49%), and FIR (9/80, 11%). Only chronic inflammatory lesions had a significant correlation with the co-incidence of CHH. CC was identified alongside CHH in 12 of 22 cases in which a CD3 immunostain was performed. The cell population in CHH was vimentin+, CD68+, CD3-, CD45-, CD56-, hPL-, SMA-, OCT 3/4- and, in some cases, variably mixed with CD3+ lymphocytes. The cells had a male genotype by fluorescent in situ hybridization analysis. Conclusion The association of CHH with acute and chronic inflammatory conditions and its immunophenotype suggest that it may be a reactive process. CD3 immunostaining is helpful to identify concurrent CC.

Gastric Carcinomas With Lymphoid Stroma: Categorization and Comparison With Solid-Type Colonic Carcinomas.

OBJECTIVES: To determine whether histologic features could help identify gastric carcinomas with lymphoid stroma associated with microsatellite instability (MSI) (ie, "medullary carcinomas"), Epstein-Barr virus (EBV) infection (termed lymphoepithelioma-like carcinomas in other organ systems), or neither. METHODS: We identified 17 solid-type gastric carcinomas with lymphoid stroma, assessed EBV and MSI status, and compared features across groups. We also compared them with 51 solid-type colorectal adenocarcinomas. RESULTS: In the stomach, EBV-associated carcinomas (n = 8) contained intratumoral germinal centers (P = .024) and eosinophils (P = .030) and lacked necrosis (P = .019) compared with MSI-associated carcinomas (n = 5) and non-EBV, non-MSI carcinomas (n = 4). In the colon, MSI-driven carcinomas (n = 40) more frequently contained intratumoral lymphocytes (P = .017) and neutrophils (P = .0050) and less often metastasized to distant sites (P = .0040) than poorly differentiated carcinomas lacking MSI (n = 11). CONCLUSIONS: Morphology may help classify gastric carcinomas with lymphoid stroma, although ancillary testing appears more reliable. Lymphoepithelioma-like carcinoma and medullary carcinoma should not be used interchangeably.

Distinction between inflammatory hepatocellular adenoma and mass effect on liver sampling.

Inflammatory hepatocellular adenoma (IHA) is characterized by sinusoidal dilation, inflammation, and bile ductular reaction. However, these changes can also be seen in nonneoplastic liver tissue adjacent to a mass lesion. This differential may arise in biopsy tissue attempting to sample a liver mass. Serum amyloid A (SAA) immunostaining is useful for the diagnosis of IHA but is not entirely specific. In addition, the histologic pattern of mass effect (ME) has received little formal scrutiny. We compared the clinical, morphologic, and immunohistochemical findings in 18 IHA and 36 livers with ME. Several histologic findings were evaluated in all cases. SAA and CD34 staining were also performed. Patients with IHA were younger (P<.0001) and more often female (P=.0044) than patients with specimens showing ME, but lesions were multifocal on imaging in two-thirds of patients in each category. Unpaired arteries were only seen in IHA (P<.0001), whereas ductular reaction was more common in ME (P=.012). Strong SAA immunostaining was observed in 100% of IHAs and 56% of ME cases (P=.0004), and CD34 staining was seen in 95% of IHAs and 6% of ME cases (P<.0001). Unpaired arteries and staining for SAA and CD34 best distinguish IHA from ME. However, unpaired arteries may be absent because of sampling, and SAA is not available in all laboratories. Ductular reaction can occur in IHA but is more common in ME.

Immunohistochemical Performance of Estrogen and Progesterone Receptor Antibodies on the Dako Omnis Staining Platform: Evaluation in Multicenter Studies.

The analysis of estrogen receptor (ER) and progesterone receptor (PR) expression levels by immunohistochemistry is an important part of the initial evaluation of breast cancer and critically important in treatment planning. Anti-ERα (clone EP1) and anti-PR (clone PgR 1294) antibodies are in development for the Dako Omnis automated staining platform. These antibodies are not yet commercially available and are in performance evaluation, including the 4 international, multicenter studies reported here. For each antibody, a reproducibility study and a method comparison study was done in a randomized manner in order to test the antibodies under conditions closest to real-world user conditions. The reproducibility studies included 5 staining runs on the Dako Omnis with 20 formalin-fixed and paraffin-embedded human breast carcinoma specimens in 3 independent laboratories, and the method comparison studies included several hundred specimens stained on the Dako Omnis and on the Autostainer Link 48 platforms. Stained slides were evaluated for nuclear ER or PR expression according to American Society of Clinical Oncology/College of American Pathologists guidelines (≥1% cut-off for positive) by pathologists who were blinded from the staining method and specimen ID. For both anti-ERα (clone EP1) and anti-PR (clone PgR 1294) on the Dako Omnis, high reproducibility agreement rates were obtained on the interrun, interlaboratory, and interobserver endpoints. High concordance rates were observed between the specimens stained on the Dako Omnis platform and the Autostainer Link 48 platform. Staining quality was excellent for both anti-ERα (clone EP1) and anti-PR (clone PgR 1294) on the Dako Omnis. These results suggest that these antibodies are reliable and reproducible tools for immunohistochemistry analysis of ER and PR expression levels in formalin-fixed and paraffin-embedded breast carcinoma tissues on the Dako Omnis platform.

Immunohistochemistry as a surrogate for molecular subtyping of gastric adenocarcinoma.

The Cancer Genome Atlas Research Network recently classified gastric adenocarcinoma into 4 molecular subtypes: Epstein-Barr virus-positive tumors, microsatellite-unstable tumors, tumors with chromosomal instability, and genomically stable tumors. We theorized that immunohistochemistry might be useful in similar categorization and that that HER2 expression might relate to subtype. We stained 104 gastric adenocarcinomas for MLH1, p53, and EBER in situ hybridization. We grouped them based on staining pattern and compared the groups. Cases were categorized as follows: group 1 (EBER positive), 7 cases (7%); group 2 (MLH1 deficient), 17 cases (16%); group 3 (aberrant p53 staining, EBER negative, retained MLH1), 40 cases (38%); group 4 (unremarkable staining), 40 cases (38%). This distribution was comparable to that found by the Research Network after accounting for the TP53 mutation rate in the chromosomal instability group. Group 1 patients had significantly longer follow-up times (median, 70 months versus 13 months for other groups; P = .0324). No group 2 cases overexpressed HER2. In group 3, 3 of 40 cases were HER2 immunohistochemistry positive, but 7 of 27 were HER2 positive by fluorescence in situ hybridization. Staining offers an efficient, reasonably accurate alternative for molecular subtyping of gastric adenocarcinoma, although some cases with chromosomal instability cannot be identified. These findings have potential prognostic and therapeutic implications.

hASH1 is a specific immunohistochemical marker for lung neuroendocrine tumors.

Mammalian/human achaete-scute homolog 1 (hASH1) regulates neuroendocrine cell development. No detailed comparative study has been conducted to explore the immunohistochemical utility of hASH1 in distinguishing different types of lung cancers. We investigated the expression of hASH1, synaptophysin, chromogranin, and CD56 in 101 squamous cell carcinomas (SCCs), 183 adenocarcinomas (ADCs), 37 typical carcinoids (TCs), 14 atypical carcinoids (ACs), 11 large cell neuroendocrine carcinomas (LCNECs), and 24 small cell lung carcinomas (SCLCs) of the lung by immunohistochemical staining with a monoclonal antibody against hASH1. Staining intensity was graded from 0 to 3, and percentage of tumor cells in each grade was estimated. All cases of ADC and SCC were discreetly negative for hASH1 in contrast to their low percentage positivity for synaptophysin, chromogranin, and CD56. hASH1 positively stained TC (64.9%), AC (64.3%), LCNEC (72.7%), and SCLC (79.2%) as did chromogranin (TC, 100%; AC, 78.6%; LCNEC, 9.0%; and SCLC, 4.2%), synaptophysin (TC, 100%; AC, 78.6%; LCNEC, 81.8%; and SCLC, 83.3%), and CD56 (TC, 59.5%; AC, 57.1%; LCNEC, 36.4%; and SCLC, 79.2%). TC and AC often showed weaker intensity and lower percentage of tumor cells positive for hASH1 (median score, 5) than LCNEC and SCLC (median score, 40 and 170, respectively). There were statistically significant differences in mean intensity scores between SCLC (148.8 ± 20.1) and other neuroendocrine tumors: TC (37.1 ± 9.2) and AC (28.6 ± 10.8) or LCNEC (51.8 ± 18.0). Our findings indicate that hASH1 is a specific marker to distinguish neuroendocrine tumors from SCC and ADC. Additionally, hASH1 is a useful diagnostic marker for segregating SCLC from other neuroendocrine tumors.

Loss of PLZF expression in prostate cancer by immunohistochemistry correlates with tumor aggressiveness and metastasis.

PLZF is a transcription repressor, which plays a critical role in development, spermatogenesis and oncogenesis. Down-regulation of PLZF has been found in various tumor cell lines. There has been virtually no tissue study on the expression of PLZF in prostate cancer (PCa). PCa is a heterogeneous disease, most of which are indolent and non-lethal. Currently there are no biomarkers that distinguish indolent from aggressive PCa; therefore there is an urgent need for such markers to provide clinical decision support. This study aimed to investigate the expression of PLZF by immunohistochemistry in different grade as well as metastatic PCa and to correlate the alteration of PLZF expression with PCa aggressiveness. We studied a total of 83 primary PCa from biopsies, 43 metastatic PCa and 8 paired primary and metastatic PCa from radical prostatectomies with lymph node dissection. Our results demonstrated that PLZF was strongly expressed in almost all (~100%) benign luminal cells (n=77) and low grade (Gleason pattern 3) PCa (n=70) and weak or absent (100%) in basal cells (n=70). Decreased or lost expression of PLZF was evidenced in 26% of high-grade (Gleason 4 and 5) primary PCa (n=70) and 84% metastatic PCa (n=43). The primary high grade PCa in the prostatectomies shared similar PLZF loss/decrease and histomorphology to that of paired parallel lymph node metastases. These data demonstrated that down-regulation of PLZF is an important molecular process for tumor progression and loss of PLZF expression detected by routine immunohistochemistry is a promising and valuable biomarker for PCa aggressiveness and metastasis in the personalized care of PCa.

Down-regulation of cytoplasmic PLZF correlates with high tumor grade and tumor aggression in non-small cell lung carcinoma.

There are currently no effective prognostic biomarkers for lung cancer. Promyelocytic leukemia zinc finger (PLZF), a transcriptional repressor, has a role in cell cycle progression and tumorigenicity in various cancers. The expression and value of PLZF in lung carcinoma, particularly in the subclass of non-small cell lung carcinoma (NSCLC), has not been studied. Our aim was to study the immunohistochemical expression of PLZF in lung adenocarcinoma and squamous cell carcinoma and correlate the alteration of PLZF expression with tumor differentiation, lymph node metastasis, tumor stage, and overall survival. A total of 296 NSCLCs being mounted on tissue microarray (181 adenocarcinomas and 91 squamous cell carcinomas) were investigated. Moderate to strong expression of PLZF was found in the cytoplasm of all the nonneoplastic respiratory epithelium and most (89.9%) well-differentiated adenocarcinoma. The proportions of moderately differentiated, poorly differentiated adenocarcinoma, and paired lymph node adenocarcinoma metastases that demonstrated negative or only weak PLZF reactivity were 75.6%, 97.2%, and 89.9%, respectively. The expression of PLZF in squamous cell carcinoma was mostly weak or absent and significantly lower than that in adenocarcinoma of the same grade (P < .0005). The loss of cytoplasmic PLZF strongly correlated with high tumor grade and lymph node metastasis in both squamous carcinoma and adenocarcinoma (P < .0001). Down-regulation of PLZF also correlated with higher tumor stage and shorter overall survival (P < .05). These results support a prognostic value for loss of cytoplasmic PLZF expression in the stratification of NSCLC and a possible role of cytoplasmic shift and down-regulation of PLZF in the pathogenesis of NSCLC.

Expression of androgen receptor and its association with estrogen receptor and androgen receptor downstream proteins in normal/benign breast luminal epithelium.

The androgen receptor (AR) is strongly expressed in the majority of breast carcinomas, but its role in breast hormonal carcinogenesis is not clear. We believe a better knowledge of the biology of normal/benign breast tissue will be the key to understanding this process. Using standard immunohistochemical staining on consecutive sections and dual immunohistochemical labeling, we studied the expression pattern of AR and estrogen receptor (ER) in normal/benign breast luminal epithelial cells. We found that most of the AR-positive cells are also ER positive, about 10% of the cells are AR-positive only, whereas ER-positive only cells are uncommon, a distribution pattern of hormone receptor expression similar to what was revealed in invasive breast carcinomas. Whereas the expression of AR downstream proteins, such as prostate-specific antigen and gross cystic disease fluid protein, was either negative or unrelated to the AR status. We conclude that AR and ER expression status in invasive breast carcinomas reflects that of their progenitor cells in terminal duct lobular units. Our study did not reveal the expression of AR downstream proteins in normal/benign luminal epithelial cells at the regular immunohistochemistry level.

High frequency of coexpression of maspin with p63 and p53 in squamous cell carcinoma but not in adenocarcinoma of the lung.

Maspin, a member of the serpin family of protease inhibitors, has been shown to inhibit tumor growth and suppress metastasis in several malignancies, including lung cancer. Previous studies have reported that p63 and p53 control maspin expression by transactivating the promoter. The present study analyzed immunohistochemical studies to determine the expression and coexpression patterns of maspin, p63 and p53 in non-small cell lung carcinoma, specifically squamous cell carcinoma and adenocarcinoma. The results showed that 83/86 cases (96.5%) of squamous cell carcinoma and 82/161 cases (50.9%) of adenocarcinoma included in this study were positive for maspin. There were 79/86 cases (91.9%) of squamous cell carcinoma and 16/161 cases (9.9%) of adenocarcinoma with positive expression for p63. In addition, 77/86 cases (89.5%) of squamous cell carcinoma and 99/161 cases (61.5%) of adenocarcinoma were positive for p53. Maspin, p63 and p53 expression were each significantly higher in squamous cell carcinoma than adenocarcinoma. Squamous cell carcinomas more highly coexpress maspin and p63, as well as maspin and p53, when compared with adenocarcinomas. The high frequency of coexpression of maspin and p63, as well as maspin and p53, in squamous cell carcinoma, suggests that p63 and p53 may be involved in the pathway to control maspin expression. Therapeutic targeting on maspin, p63 and p53 molecules might be beneficial in the management of patients with squamous cell carcinomas of the lung in the future.

MACC1 is related to colorectal cancer initiation and early-stage invasive growth.

OBJECTIVES: To investigate metastasis associated in colon cancer 1 (MACC1) and MET expression in colorectal adenoma, Tis, early-stage invasive (T1 and T2), and advanced adenocarcinoma with liver metastasis using immunohistochemistry. METHODS: Ninety-three paraffin-embedded colorectal tumor specimens were immunohistochemically analyzed for MACC1 and MET protein expression. RESULTS: MACC1 expression was upregulated in the transition from adenoma to Tis; its expression was further elevated during tumor progression from Tis to early invasive carcinoma. MET expression was constant from adenoma to Tis and to T1 but significantly increased as tumor progression to T2. Both MACC1 and MET expression were enhanced in advanced carcinoma with liver metastasis. CONCLUSIONS: Stepwise elevation of MACC1 expression in key points of colorectal cancer development suggests that MACC1 may contribute to cancer initiation and early invasive growth. High expression of both MACC1 and MET may relate to distant metastasis.

Regulation of human osteoclast development by dendritic cell-specific transmembrane protein (DC-STAMP).

Osteoclasts (OC) are bone-resorbing, multinucleated cells that are generated via fusion of OC precursors (OCP). The frequency of OCP is elevated in patients with erosive inflammatory arthritis and metabolic bone diseases. Although many cytokines and cell surface receptors are known to participate in osteoclastogenesis, the molecular mechanisms underlying the regulation of this cellular transformation are poorly understood. Herein, we focused our studies on the dendritic cell-specific transmembrane protein (DC-STAMP), a seven-pass transmembrane receptor-like protein known to be essential for cell-to-cell fusion during osteoclastogenesis. We identified an immunoreceptor tyrosine-based inhibitory motif (ITIM) in the cytoplasmic tail of DC-STAMP, and developed an anti-DC-STAMP monoclonal antibody 1A2 that detected DC-STAMP expression on human tumor giant cells, blocked OC formation in vitro, and distinguished four patterns of human PBMC with a positive correlation to OC potential. In freshly isolated monocytes, DC-STAMP(high) cells produced a higher number of OC in culture than DC-STAMP(low) cells and the surface expression of DC-STAMP gradually declined during osteoclastogenesis. Importantly, we showed that DC-STAMP is phosphorylated on its tyrosine residues and physically interacts with SHP-1 and CD16, an SH2-domain-containing tyrosine phosphatase and an ITAM-associated protein, respectively. Taken together, these data show that DC-STAMP is a potential OCP biomarker in inflammatory arthritis. Moreover, in addition to its effect on cell fusion, DC-STAMP dynamically regulates cell signaling during osteoclastogenesis.