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Xp11.2 translocation renal cell carcinoma (Xp11.2 RCC) is a subtype of RCC characterized by translocations involving a breakpoint at the TFE3 gene (Xp11.2). Moderate to strong nuclear TFE3 immunoreactivity has been recognized as a specific diagnostic marker for this type of tumor. However, exclusive cytoplasmic localization of a TFE3 fusion protein was reported in UOK 145 cells, a cell line derived from an Xp11.2 RCC harboring the PSF-TFE3 translocation. If reproducible using immunohistochemistry (IHC), this finding would have important implications for pathologists in the diagnosis of Xp11.2 RCC, calling into question the specificity of nuclear immunoreactivity for TFE3 in these tumors. The purpose of this study was to determine whether the above-noted cytoplasmic localization of the TFE3 fusion protein could be reproduced using IHC. UOK 145 cells and fresh frozen tissue from 2 clinical cases of Xp11.2 RCC found to harbor the PSF-TFE3 gene rearrangement (by cytogenetic testing) were collected. All samples were subjected to histopathologic evaluation by board-certified pathologists, TFE3 IHC, reverse transcription polymerase chain reaction, and Sanger sequencing analysis. A strong nuclear TFE3 immunoreactivity was demonstrated in all samples including the UOK 145 cell line. No cytoplasmic immunoreactivity was seen. Reverse transcription polymerase chain reaction and Sanger sequencing confirmed the previously reported PSF-TFE3 gene fusion between exon 9 of PSF and exon 6 of TFE3 in the UOK 145 cell line and in one of 2 clinical cases of Xp11.2 RCC. A novel PSF-TFE3 gene fusion between exon 9 of PSF and exon 5 of TFE3 was detected in the second clinical case of Xp11.2 RCC.

Context.—The World Health Organization classification of renal tumors synthesizes morphologic, immunohistochemical, and molecular findings to define more than 40 tumor types. Of these, clear cell (conventional) renal cell carcinoma is the most common malignant tumor in adults and—with the exception of some rare tumors—the most deadly. The diagnosis of clear cell renal cell carcinoma on morphologic grounds alone is generally straightforward, but challenging cases are not infrequent. A misdiagnosis of clear cell renal cell carcinoma has clinical consequences, particularly in the current era of targeted therapies.Objective.—To highlight morphologic mimics of clear cell renal cell carcinoma and provide strategies to help differentiate clear cell renal cell carcinoma from other renal tumors and lesions. The role of the pathologist in guiding treatment for renal malignancies will be emphasized to stress the importance of proper tumor classification in patient management.Data Sources.—Published literature and personal experience.Conclusions.—In challenging cases, submission of additional tissue is often an inexpensive and effective way to facilitate a correct diagnosis. If immunohistochemical stains are to be used, it is best to use a panel of markers, as no one marker is specific for a given renal tumor subtype. Selection of limited markers, based on a specific differential diagnosis, can be as useful as a large panel in reaching a definitive diagnosis. For renal tumors, both the presence and absence of immunoreactivity and the pattern of labeling (membranous, cytoplasmic, diffuse, focal) are important when interpreting the results of immunohistochemical stains.

The transmembrane protease, serine 2-E twenty-six related gene (TMPRSS2-ERG) fusion leading to ERG overexpression, was detected in approximately 50% of prostate cancers (ranging from 35-70%). However, the published data on ERG expression in tumors from other organs and normal tissues were limited. In this study, we investigated the expression of ERG in TMA sections of various normal tissues (N=452) and carcinomas (N=1,129) from various organs, including 90 cases of low to intermediate-grade (L-MG) prostatic adenocarcinomas and 36 cases of high-grade (HG) prostatic adenocarcinomas, using a single immunostaining system (Dako). Also included were prostatic biopsies of radiation atypia (N=20), atrophy (N=20), and high-grade prostatic intraepithelial lesion (HGPIN) (N=18). ERG expression was detected in 44% (40/90) of L-MG prostatic adenocarcinomas; in 22% (8/36) of HG prostatic adenocarcinomas; and in 22% (4/18) of HGPIN. No ERG expression was detected in non-prostate carcinomas, normal tissues including prostate and seminal vesicles, benign prostatic tissue with radiation atypia, and atrophy. Our data demonstrate that ERG is a highly specific marker, which may have important implications in the interpretation of prostate biopsies with limited cancers. In addition, its high diagnostic specificity may be useful in identifying a prostatic primary when working on a tumor of uncertain origin. Partly presented at the United States and Canadian Academy of Pathology Annual Meeting in March 2011.

Context.—Glandular lesions of the urinary bladder include a broad spectrum of entities ranging from completely benign glandular lesions to primary and secondary malignancies. Common benign bladder lesions that exhibit glandular differentiation include cystitis cystica, cystitis glandularis, von Brunn nests, nephrogenic adenoma, intestinal metaplasia, urachal remnant, endometriosis, and prostatic-type polyp. The World Health Organization defines primary adenocarcinoma of the bladder as an epithelial malignancy with pure glandular differentiation without evidence of typical urothelial carcinoma. Malignant lesions that should be included in the differential diagnosis of a primary adenocarcinoma of the bladder include noninvasive and invasive urothelial carcinoma with glandular differentiation and secondary malignancies involving the bladder by direct extension or metastasis. The recognition and distinction of these different entities may be a challenge for pathologists, but they are of great clinical importance. Objective.—To review features of primary bladder adenocarcinoma as well as those entities that need to be differentiated from primary bladder adenocarcinoma, with emphasis on clinical findings, pathologic characteristics, and immunoprofiles. Data Sources.—Selected original articles published in the PubMed service of the US National Library of Medicine. Conclusions.—The accurate diagnosis of adenocarcinoma of the urinary bladder is important and challenging. It has to prompt an extensive clinical workup to rule out other glandular lesions in the urinary bladder, especially the possibility of secondary involvement of the bladder by an adenocarcinoma from a different site.

Lichen sclerosus is an inflammatory skin disorder affecting anogenital areas in males and females that is associated with squamous cell carcinoma. However, there is a lack of data on the role of biomarkers for predicting lichen sclerosus progression to squamous cell carcinoma. We focused on early protein markers of squamous cell carcinoma and their expression in lichen sclerosus to improve the mechanistic and diagnostic understanding of lichen sclerosus.We performed an extensive PubMed® and MEDLINE® search for protein markers found in early stages of vulvar and penile squamous cell carcinoma, and their prevalence in associated lichen sclerosus lesions.In recent years several markers have been implicated as precursor markers for malignant transformation of lichen sclerosus into squamous cell carcinoma, including p53, Ki-67, γ-H2AX, MCM3 and cyclin D1. These proteins are up-regulated in lichen sclerosus of the vulva/penis and squamous cell carcinoma. Various levels of evidence show an association between lichen sclerosus and squamous cell carcinoma. p16 is over expressed in penile and vulvar squamous cell carcinoma associated with human papillomavirus infection but conflicting reports exist about its expression in lichen sclerosus. The angiogenesis markers vascular endothelial growth factor and cyclooxygenase-2 are expressed at higher levels, and microvessel density is increased in vulvar lichen sclerosus and squamous cell carcinoma, indicating a possible similar association in penile lichen sclerosus.Only a minority of lichen sclerosus cases are associated with squamous cell carcinoma. However, the therapeutic implications of a squamous cell carcinoma diagnosis are severe. Clinically, we lack an understanding of how to separate indolent lichen sclerosus cases from those in danger of progression to squamous cell carcinoma. Several protein markers show promise for further delineating the pathobiology of lichen sclerosus and the potential malignant transformation into squamous cell carcinoma.

Neuroendocrine prostate cancer (NEPC) is a subtype of prostate cancer that is highly aggressive and exhibits a neuroendocrine phenotype, being distinct from prostate adenocarcinoma. Cases of NEPC are predicted to increase rapidly following broader use of new-generation hormonal therapies including abiraterone and enzalutamide. Although androgen deprivation and cytokine induction have been previously suggested to induce neuroendocrine differentiation of prostate cancer, little is known regarding the underlying molecular mechanisms. FOXA1 is a forkhead box family transcription factor that has been shown to act as a pioneer factor for androgen receptor (AR), thereby defining the prostatic transcriptional program. We have recently shown that FOXA1 plays an important role in suppressing epithelial-to-mesenchymal transdifferentiation, but is often downregulated in castration-resistant prostate cancer (CRPC). Along this line, in the present study, we showed that FOXA1 loss, achieved by shRNA-mediated knockdown, led to cell morphology changes typical of neuroendocrine differentiation, accompanied by a strong increase of NEPC marker enolase2 (ENO2), while ectopic FOXA1 overexpression reverses these alterations. This was further linked to ERK phosphorylation, which has been previously reported to be up-regulated following neuroendocrine differentiation. Moreover, to understand the mechanism underlying FOXA1 regulation of neuroendocrine differentiation, we performed bioinformatics analysis and nominated interleukin 8 (IL8) as a direct target of FOXA1 and its up-regulation is critical in mediating neuroendocrine differentiation of FOXA1-depleted cells. Finally, we validated a negative correlation between FOXA1 and neuroendocrine differentiation in primary prostate cancer specimens through analysis of publically available RNA-seq data as well as direct IHC staining of various NEPC markers. In summary, we report a new role of FOXA1 as a critical inhibitor of neuroendocrine differentiation and the importance of balanced FOXA1 expressing in the maintenance of the epithelial phenotype of prostate cancer. Citation Format: Jung Kim, Hongjian Jin, Jonathan Zhao, Vamsi Parimi, Ximing Yang, Jindan Yu. FOXA1, a novel regulator of neuroendocrine differentiation. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1801.

regulated the expression of miR-151 compared with vehicle control. Kaplan-Meier curves and log-rank tests revealed that high expression levels of miR-151 had a significant adverse effect on survival rate. Inhibition of miR-151 in prostate cancer cells by genistein significantly inhibited cell migration and invasion. By in-cilico analysis, several genes (N4BP1, CASZ1, IL1RAPL1, LGI1, SOX17 and TOM1L1) that are suggested to have tumor suppressive function in several types of cancers were detected as candidate target genes of miR-151. CONCLUSIONS: We demonstrated that genistein down-regulated miR-151 that functions as an oncogenic miRNA in prostate cancer. This study suggests that genistein mediated suppression of oncogenic miRNAs can be an important dietary therapeutic strategy for the treatment of prostate cancer.

We hereby report the case of a patient with a papillary fibroelastoma involving the right coronary cusp of the aortic valve that was diagnosed with the use of transesophageal echocardiography after workup for recurrent transient ischemic attacks. (J Am Echocardiogr 2002;15:382-4.)

High expression of carbonic anhydrase IX (CAIX) is reported for clear cell renal cell carcinoma (RCC), with a paucity of data for non-renal genitourinary or adrenal tumours. This study investigated the immunohistochemical expression of CAIX throughout the genitourinary tract and adrenal gland.High expression in the renal cortex was restricted to clear cell, papillary and clear cell papillary RCC and carcinoid. Core biopsies of clear cell RCC were consistently positive. Positivity within the urothelial tract was seen in urothelial carcinoma including squamous, small-cell, sarcomatoid and adenomatous differentiation and clear cell adenocarcinoma. Signet ring and plasmacytoid variants of urothelial carcinoma were negative. Phaeochromocytoma, adrenal cortical adenoma, seminoma, yolk sac tumour, choriocarcinoma, Leydig cell tumour and prostatic adenocarcinoma were predominately negative, with variable reactivity in adrenal cortical carcinoma, embryonal carcinoma, teratoma and Sertoli cell tumour.Carbonic anhydrase IX is a sensitive marker for clear cell RCC in core biopsies. However, other genitourinary or adrenal tumours that can have a clear cell appearance including urothelial, squamous cell, clear cell adeno and adrenal cortical carcinoma and Sertoli cell tumour express CAIX. Knowledge of expression overlap between these entities may prevent incorrect interpretation of immunohistochemical results, particularly if limited tissue is available.

Tubulocystic carcinoma is a rare renal tumor with distinct characteristics which were recently described in details in three large series (1, 2, 3). Tubulocystic carcinomas of the kidney well circumscribed tumors. They are usually solitary and are composed of closely packed tubules and cysts separated by fibrous stroma and lined by a single layer of cuboidal cells with eosinophilic cytoplasm and prominent nucleoli, sometimes with a hobnail appearance. These tumors show a low but definite risk of metastasis, and it is therefore important to distinguish them from other benign and malignant renal lesions included in the differential diagnosis. Tubulocystic carcinoma was originally described as a subtype of collecting duct carcinoma (4). Carcinoma of the collecting duct of Bellini, first described by Pierre Masson (5) and characterized by a tubular or tubulopapillary growth pattern with high grade nuclei, follows an aggressive clinical course with a very poor prognosis. When tubulocystic carcinoma was first described, it was included in a series of 13 cases called “low grade collecting duct carcinoma” (4); these tumors feature a favorable clinical outcome distinct from high grade collecting duct carcinoma of the kidney. The entity “low grade collecting duct carcinoma” was later divided into two distinct subtypes, mucinous tubular and spindle cell carcinoma (6-8) and tubulocystic carcinoma (5). While mucinous tubular and spindle cell carcinoma is now recognized as a distinct subtype of renal cell carcinoma (RCC) in the World Health Organization classification system of renal tumors (WHO) (3), tubulocystic carcinoma is still being characterized (1, 2, 3, 9) and is not yet included in the current WHO classification system. Mounting morphologic, biologic, immunohistochemical, and molecular evidence supports that this tumor represents a unique subtype of RCC (1, 2, 3).

Alias Renal papillary adenoma Tubulo-papillary adenoma Note The concept of renal papillary adenoma is a controversial one, and has evolved over the past 3 decades. The term has historically been used to refer to small proliferations of papillary or tubulo-papillary epithelium in the renal cortex which theoretically have no metastatic potential. The size criterion in this definition is somewhat arbitrary and has become progressively smaller, from less than 3cm in early autopsy series, to more current consensus definitions restricting the lesions to less than 0.5cm.

Summary To date, only a few cases of "rosette forming t(6;11), HMB45-positive renal carcinoma" have been published. In this article, we contribute further data on 4 cases of this rare entity. Patients were 3 women and 1 man with an age range of 20 to 54 years (median, 23 years). Follow-up (range, 3-5 years; median, 4 years) did not reveal any metastatic events or recurrences. All tumors were well circumscribed and mostly encapsulated with homogeneous gray to tan cut surfaces. No necrosis was seen. All tumors displayed a solid or solid/alveolar architecture and contained occasionally long and branching tubular structures composed of discohesive neoplastic cells and pseudorosettes. The presence of pseudorosettes was a constant finding, but the number of pseudorosettes varied significantly among cases. All cases displayed focal immunoreactivity for the melanocytic marker HMB45, cathepsin K, and vimentin. Melan A, tyrosinase, cytokeratins, CD10, and microphthalmia transcription factor were each positive in 3 of 4 cases. On ultrastructural examination, numerous electron-dense secretory cytoplasmic granules with some resemblance to melanosomes were identified. The pseudorosettes were composed of reduplicated basement membrane material surrounded by small lymphocyte-like neoplastic cells. Using reverse transcription polymerase chain reaction, 2 tumors were positive for the Alpha-TFEB fusion transcript. The presence of the translocation t(6;11)( Alpha - TFEB ) was confirmed in 2 analyzed cases. No von Hippel–Lindau tumor suppressor gene mutation, promotor methylation or loss of heterozygosity of 3p was found. Losses of part of chromosome 1 and chromosome 22 were found in one case.

Lin Chen, Qiang Zhang*, Brian Helfand, Vidit Sharma, Chicago, IL; Weijun Qin, Xian, China, People’s Republic of; Charles Brendler, Chicago, Please choose an option below; Lihua Zhu, Boston, IL; Shilajit D Kundu, Chicago, IL; Thomas Jiang, New Brunswick, NJ; Weipeng Zhang, Bob Lee, Sherin Randall-London, Borko Jovanovic, Ximing J Yang, James Kozlowski, Timothy Michael Kuzel, Chicago, IL; Yinglu Guo, Beijing, China, People’s Republic of; Chung Lee, Chicago, IL

We describe a technique for segmenting individual prostatic glands in hematoxylin-and-eosin stained prostatic tissue images. The method begins with image artifact correction, then segments the image into four tissue components using principal component analysis and k-means clustering, and finally identifies glands using a region-growing algorithm. We calculated the average gland size to distinguish cancer glands from non-cancer glands. Quantitative comparison between computer and manual outlines of glands based on 62 images (25 containing cancer) indicated an agreement of up to 67%, which approached the inter-observer agreement. Subjective evaluation corroborated these quantitative results and indicated that the technique segmented benign glands more accurately than malignant glands. Area under the receiver operating characteristic (ROC) curve of the average-gland-size feature was 0.92 in distinguishing prostate cancer from non-cancer glands.

To compare the old classification and 2004 WHO histological classification of renal cell carcinoma, summarize the differences and possible reasons, and correct the traditional pathological concepts of kidney cancer.Specimens of 79 cases histopathologically diagnosed as non-clear cell renal cell carcinomas after radical nephrectomy during 1998 to 2005 in Tianjin Medical University Cancer Hospital were reclassified according to the 2004 WHO renal cell carcinoma histological classification system.After reclassification, there were 14 cases of clear cell renal cell carcinoma (CCRCC), 23 cases of papillary renal cell carcinoma (PRCC), 34 cases of chromophobe renal cell carcinoma (ChRCC), one collecting duct renal cell carcinoma, one unclassified renal cell carcinoma, 5 cases of mixed cell renal cell carcinoma (CCRCC + PRCC 2 cases, CCRCC + ChRCC 2 cases, PRCC + ChRCC 1 case), and one oncocytoma diagnosed.Some chromophobe renal cell carcinomas and papillary renal cell carcinomas were easier to be diagnosed as granular cell renal cell carcinoma in the past. The eosinophilic cytoplasm similar to that in the granular cells, and some confusion between PRCC and ChRCC are the main reasons. The cellular characteristic features of granular renal cell carcinoma can be found in many types of renal tumors. Granular cell renal cell carcinoma is not an independent entity, therefore, it should be removed from the histological classification of renal cell carcinoma. The diagnosis standard of mixed renal cell carcinoma (MRCC) need to be determined and consummated.

Background Glypican-3 (GPC3) is a membrane-bound heparan sulfate proteoglycan that functions in embryonic cell growth and differentiation and is highly expressed in the placenta. GPC3 is mutated in Simpson-Golabi-Behmel syndrome, which is characterized by tissue overgrowth and an increased risk of embryonal malignancies. GPC3 has also been implicated in sporadic cancer, particularly hepatocellular carcinoma, for which it has been shown to be a useful diagnostic marker. Although GPC3 expression has been studied in non-neoplastic placental tissue, its presence in gestational trophoblastic diseases has not been previously explored. The purpose of this study was to investigate the immunohistochemical expression of GPC3 in placental site trophoblastic tumor (PSTT), a very rare gestational trophoblastic neoplasm which may be morphologically confused with non-trophoblastic tumors, and to assess its possible utility as a diagnostic marker. Methods Fifteen cases of PSTT, as well as samples from placental site nodule (PSN) (n = 2), leiomyosarcoma (n = 1), leiomyoma (n = 1), invasive cervical squamous cell carcinoma (n = 7) and endometrial adenocarcinoma (n = 11) were examined. Immunoreactivity was semi-quantitatively evaluated as negative (0, < 5% of cells stained), focally positive (1+, 5-10% of cells stained), positive (2+, 11-50% of cells stained) or diffusely positive (3+, > 50% of cells stained). Staining intensity for each subtype was graded from 0 to 3 and a mean intensity was calculated. Results Eighty percent of PSTT (12/15) were immunoreactive for GPC3 (0, 20; 1+, 20%; 2+, 40%; 3+, 20%) with a mean intensity of 1.3. Stronger, predominately cytoplasmic staining was seen in larger multi- and mononucleated cells with smaller mononucleate cells showing weak muddy cytoplasmic staining. Both PSN cases were positive (1+, 50%; 2+, 50%) and two of nine invasive cervical squamous cell carcinomas showed staining (0, 57%; 1+, 29%; 2+, 14%), predominately in a basal distribution. Other uterine tumors and non-neoplastic tissues were negative. Conclusions Identification of GPC3 in PSTT and PSN is consistent with the derivation of these lesions from intermediate trophoblasts, which have been described to express GPC3. GPC3 may be a useful adjunct immunohistochemical marker in differentiating PSTT from non-trophoblastic tumors.

Tissue factor (TF) is a cell surface glycoprotein intricately related to blood coagulation and inflammation. This study was performed to investigate the role of monocyte-lineage cells in prostate cancer cell TF expression and cell invasion.Prostate cancer cell invasion was tested with and without added peripheral blood monocytes or human monocyte-lineage cell lines. TF neutralizing antibodies were used to determine the TF requirement for prostate cancer cell invasion activity. Immunohistochemistry was performed to identify prostate tissue CD68 positive monocyte-derived cells and prostate epithelial TF expression.Co-culture of PC-3, DU145, and LNCaP cells with isolated human monocytes significantly stimulated prostate cancer cell invasion activity. TF expression was greater in highly invasive prostate cancer cells and was induced in PC-3, DU145, and LNCaP cells by co-culture with U-937 cells, but not with THP-1 cells. TF neutralizing antibodies inhibited PC-3 cell invasion in co-cultures with monocyte-lineage U-937 or THP-1 cells. Prostate cancer tissues contained more CD68 positive cells in the stroma and epithelium (145 ± 53/mm(2)) than benign prostate (108 ± 31/mm(2)). Samples from advanced stage prostate cancer tended to contain more CD68 positive cells when compared with lower stage lesions. Prostatic adenocarcinoma demonstrated significantly increased TF expression compared with benign prostatic epithelium.This study shows that co-culture with monocyte-lineage cells induced prostate cancer cell invasion activity. PC-3 invasion and TF expression was induced in co-culture with U-937 cells and partially inhibited with TF neutralizing antibodies.

Stem cells were suggested to be present in human prostate cancer as a small population of distinct cells, which may contribute to carcinogenesis, tumor recurrence, and chemoresistance. To identify potential prostatic stem cells, we analyzed the expression of several potential stem cell markers in benign prostate and prostatic adenocarcinoma.CD44, CD133, Oct4, SOX2, and EZH2 expression was detected by immunohistochemical (IHC) staining using tissue microarray assays (TMA) composed of benign (non-neoplastic) prostatic tissue, high grade prostatic intraepithelial neoplasia (HGPIN), and prostatic adenocarcinoma. Positive staining was defined as 1+ (10%), 2+ (10-50%), or 3+ (50%).We found CD44 staining in 97% and 72% of benign + HGPIN and malignant lesions, respectively. CD133 staining was detected in a small fraction (4 of 67) of prostate carcinomas. We found that Oct4 nuclear expression was strongly associated with benign lesions and HGPIN but not prostate cancer (P 0.05). In most cases, nuclear expression of EZH2 and SOX2 was detected in less than 10% of cells in non-neoplastic prostate glands, HGPINs or prostate adenocarcinomas. Moreover, 27 of 33 SOX2 1+ prostate cancers were also EZH2 1+, whereas all 33 of these cases were CD44+.Expression of CD44 and Oct4 identified large populations of benign and malignant cells in the prostate, which did not fit the definition of stem cells as a small fraction of the total cell population. Our results suggest that combined expression of embryonic stem cell markers EZH2 and SOX2 might identify potential cancer stem cells as a minor (10%) subgroup in CD44+ prostatic adenocarcinoma.

Glypican 3 (GPC3) has been reported to be overexpressed in yolk sac tumour (YST), but the sensitivity has not been compared with alpha-fetoprotein (AFP). YST can form numerous growth patterns and the expression of GPC3 in these patterns has not been studied. The aim was to address these aspects.Sections from testicular or ovarian YST were subjected to immunohistochemistry using GPC3 (n = 39) and AFP (n = 24). Overall immunoreactivity for each case and specific histological patterns were semiquantitatively evaluated (0-3+) and intensity of reactivity was scored (0-3). All cases expressed GPC3 (1+, 5%; 2+, 8%; 3+, 87%) with strong intensity (2.9). The majority expressed AFP (58%) but immunoreactivity was often focal (0, 42%; 1+, 33%; 2+, 25%) and intensity was low (1.0). Using GPC3,75% of the microcystic (n = 38), macrocystic (n = 26), solid (n = 21), glandular-alveolar (n = 8), endodermal sinus (n = 7), polyvesicular vitelline (n = 5), enteric (n = 4) and micropapillary (n = 2) growth patterns displayed 2+ or 3+ positivity.YST can display a variety of growth patterns that can be confused with other germ cell tumour components. GPC3 detects all growth patterns tested and has a higher sensitivity for detecting YST than AFP.

Paraneoplastic neuropathy is a potential complication of renal cell carcinoma. The clinical and electrophysiologic features of such patients have not been well characterized. We describe a patient with a demyelinating neuropathy associated with papillary renal cell carcinoma that resolved following nephrectomy. The literature is reviewed with particular attention to the clinical, electrophysiologic, and kidney histopathologic characteristics of similar patients. Features arguing against other acquired demyelinating neuropathies are highlighted, and we conclude that abdominal imaging may provide important diagnostic data in some patients with evolving demyelinating neuropathies. The significance of papillary renal cell carcinoma (as opposed to clear renal cell carcinoma) is unknown, but may have important pathophysiologic implications.

Background Chromophobe renal cell carcinoma (chRCC) and renal oncocytoma are two distinct but closely related entities with strong morphologic and genetic similarities. While chRCC is a malignant tumor, oncocytoma is usually regarded as a benign entity. The overlapping characteristics are best explained by a common cellular origin, and the biologic differences between chRCC and oncocytoma are therefore of considerable interest in terms of carcinogenesis, diagnosis and clinical management. Previous studies have been relatively limited in terms of examining the differences between oncocytoma and chromophobe RCC. Methods Gene expression profiling using the Affymetrix HGU133Plus2 platform was applied on chRCC (n = 15) and oncocytoma specimens (n = 15). Supervised analysis was applied to identify a discriminatory gene signature, as well as differentially expressed genes. High throughput single-nucleotide polymorphism (SNP) genotyping was performed on independent samples (n = 14) using Affymetrix GeneChip Mapping 100 K arrays to assess correlation between expression and gene copy number. Immunohistochemical validation was performed in an independent set of tumors. Results A novel 14 probe-set signature was developed to classify the tumors internally with 93% accuracy, and this was successfully validated on an external data-set with 94% accuracy. Pathway analysis highlighted clinically relevant dysregulated pathways of c-erbB2 and mammalian target of rapamycin (mTOR) signaling in chRCC, but no significant differences in p-AKT or extracellular HER2 expression was identified on immunohistochemistry. Loss of chromosome 1p, reflected in both cytogenetic and expression analysis, is common to both entities, implying this may be an early event in histogenesis. Multiple regional areas of cytogenetic alterations and corresponding expression biases differentiating the two entities were identified. Parafibromin, aquaporin 6, and synaptogyrin 3 were novel immunohistochemical markers effectively discriminating the two pathologic entities. Conclusions Gene expression profiles, high-throughput SNP genotyping, and pathway analysis effectively distinguish chRCC from oncocytoma. We have generated a novel transcript predictor that is able to discriminate between the two entities accurately, and which has been validated both in an internal and an independent data-set, implying generalizability. A cytogenetic alteration, loss of chromosome 1p, common to renal oncocytoma and chRCC has been identified, providing the opportunities for identifying novel tumor suppressor genes and we have identified a series of immunohistochemical markers that are clinically useful in discriminating chRCC and oncocytoma.

Although retinoic acid (RA) is a potent agent that coordinates inhibition of proliferation with differentiation of many cell types, RA-mediated signaling pathways in osteosarcoma cell differentiation are uncharacterized. In this study, we show that in human U2OS osteosarcoma cells, decreased phosphorylation of RA receptor alpha (RARalpha) by RA treatment or overexpressing a phosphorylation-defective mutant RARalphaS77A results in the inhibition of proliferation and induction of differentiation, and that U2OS cells transduced with RARalphaS77A suppresses tumor formation in nude mice. Moreover, using different human primary osteosarcoma cells and human mesenchymal stem cells for gene expression analysis, we found that either RA or RARalphaS77A induces many of the same differentiation response pathways and signaling molecules involved in U2OS cell differentiation. In addition, overexpression of the fibroblast growth factor 8f (FGF8f), one of the downstream targets induced by both RA and RARalphaS77A in U2OS cells, inhibits proliferation and induces expression of osteoblastic differentiation regulators. Hence, these data strongly suggest that RA-suppressed phosphorylation of RARalpha induces FGF8f expression to mediate differentiation response pathway in U2OS osteosarcoma cells.

Background Germline mutations in the folliculin (FLCN) gene are associated with the development of Birt-Hogg-Dubé syndrome (BHDS), a disease characterized by papular skin lesions, a high occurrence of spontaneous pneumothorax, and the development of renal neoplasias. The majority of renal tumors that arise in BHDS-affected individuals are histologically similar to sporadic chromophobe renal cell carcinoma (RCC) and sporadic renal oncocytoma. However, most sporadic tumors lack FLCN mutations and the extent to which the BHDS-derived renal tumors share genetic defects associated with the sporadic tumors has not been well studied. Methods BHDS individuals were identified symptomatically and FLCN mutations were confirmed by DNA sequencing. Comparative gene expression profiling analyses were carried out on renal tumors isolated from individuals afflicted with BHDS and a panel of sporadic renal tumors of different subtypes using discriminate and clustering approaches. qRT-PCR was used to confirm selected results of the gene expression analyses. We further analyzed differentially expressed genes using gene set enrichment analysis and pathway analysis approaches. Pathway analysis results were confirmed by generation of independent pathway signatures and application to additional datasets. Results Renal tumors isolated from individuals with BHDS showed distinct gene expression and cytogenetic characteristics from sporadic renal oncocytoma and chromophobe RCC. The most prominent molecular feature of BHDS-derived kidney tumors was high expression of mitochondria-and oxidative phosphorylation (OXPHOS)-associated genes. This mitochondria expression phenotype was associated with deregulation of the PGC-1α-TFAM signaling axis. Loss of FLCN expression across various tumor types is also associated with increased nuclear mitochondrial gene expression. Conclusions Our results support a genetic distinction between BHDS-associated tumors and other renal neoplasias. In addition, deregulation of the PGC-1α-TFAM signaling axis is most pronounced in renal tumors that harbor FLCN mutations and in tumors from other organs that have relatively low expression of FLCN. These results are consistent with the recently discovered interaction between FLCN and AMPK and support a model in which FLCN is a regulator of mitochondrial function.

Bladder cancer is estimated to be the seventh most prevalent malignancy worldwide. Greater than 90% of the tumors within the bladder are urothelial carcinoma. Urothelial carcinoma of the bladder is distinct from other epithelial carcinomas in that it is thought to have two divergent pathways of carcinogenesis. Studies have shown that superficial/low grade papillary tumors develop along one molecular pathway while muscle invasive tumors and CIS develop along a different molecular pathway. Deletions of chromosome 9 are more commonly associated with superficial/papillary tumors while loss of heterozygosity on chromosome 17 is more frequently seen in carcinoma in situ and invasive tumor. In addition, low grade papillary tumors are shown to have activating mutations involving tyrosine kinase receptors, such as, fibroblast growth factor receptor 3 (FGFR3), and its pathways, such as, Ras and phosphoinositide 3-kinase (PI3K) pathways. In contrast, most carcinoma in situ and high grade invasive tumors have defects in the p53 and retinoblastoma (RB) protein genes and their pathways. Chromosomal 9 alterations and activating mutations of tyrosine kinase receptors and its pathways involving superficial/papillary tumors will be discussed in this chapter.

Tubulocystic carcinoma of the kidney (TC-RCC) is a rare renal tumor with unique gross and microscopic features unlike other types of renal cell carcinoma (RCC). Several recent studies recommend that it should be classified as a distinct RCC subtype. In this study, we provide pathologic and cytogenetic evidence supporting that TC-RCC is closely related to papillary RCC (PRCC). This study included 20 cases of renal tumors that partially or exclusively comprised a TC-RCC component. Pathologic examination documented the gross and microscopic features of TC-RCC, including multicentricity and the presence of concomitant PRCC and papillary adenoma. Formalin-fixed, paraffin-embedded sections from 12 TC-RCC and 20 PRCC were subjected to a multicolor fluorescence in situ hybridization assay containing probes for chromosomes 7, 17, and Y. One hundred nuclei were examined to enumerate the copy numbers of chromosomes in each tumor and its corresponding normal kidney tissue. A tumor with a percentage of cells harboring a chromosomal change > or = mean+3 SD of normal tissue was considered to harbor that chromosomal change, and a tumor with a percentage of cells with null Y chromosome count (loss of Y chromosome) > or = mean+3 SD of normal tissue was considered to harbor Y chromosome loss. Four of the 20 TC-RCCs were multicentric. Ten had associated PRCC or papillary adenoma within the same kidney as the TC-RCC. In 4 cases, the tubulocystic and papillary components were admixed together within the same lesion. The tumor cells lining both the tubulocystic and papillary components had similar cytologic features. Ten of 12 TC-RCCs had a chromosome 7 gain, 8 of 12 cases had a chromosome 17 gain, and 8 of 9 cases had a loss of Y chromosome. Six of 9 cases with all 3 chromosomes studied had a gain of chromosomes 7 and 17 and a loss of Y chromosome. Our study shows that TC-RCCs and PRCCs are closely related entities. With its distinctive gross and microscopic features, TC-RCC may be considered a unique "morphologic entity." However, before it is accepted as a distinct renal cell carcinoma subtype, further studies are needed to document a characteristic molecular signature associated with this tumor.

The epothilone B analogue, ixabepilone, binds to β-tubulin, is effective for taxane-refractory metastatic breast cancer (MBC), and may be given every 3 weeks or weekly. We evaluated the efficacy of weekly ixabepilone (I) plus trastuzumab (T) and carboplatin (C) as first line therapy in HER2 + MBC. Patients with HER2+ (3+ by IHC or FISH amplified) MBC received I (15 mg/m2 IV) and C (area under the curve, AUC = 2 IV) on days 1, 8, and 15 of a 28-day cycle for a maximum of 6 cycles, plus weekly T (4 mg/kg loading dose then 2 mg/kg IV) during chemotherapy then every 3 weeks (6 mg/kg IV) until disease progression. The primary objective was to determine whether the combination was associated with a response rate (RR) of at least 75%. Fifty-nine patients were treated, and 39 had HER2 overexpression confirmed in a central lab (cHER2+). For all treated patients, objective response occurred in 26 patients (44%; 95% CI 31–58%), median time to progression was 8.2 months (95% CI 6.3–9.9), and median overall survival was 34.7 months (95% CI 25.7 to [not reached]). Results were comparable for cHer2+ cancers. Grade 3–4 adverse events included neutropenia (49%), thrombocytopenia (14%), fatigue (12%), nausea (7%), diarrhea (7%), and neuropathy (7%). One patient died from treatment complications during cycle 1. Weekly ixabepilone and carboplatin plus trastuzumab have an acceptable toxicity profile, but are not likely to be associated with an RR of 75% in HER2+ MBC. Efficacy appears comparable to paclitaxel, carboplatin, and trastuzumab.

Dietary intake of genistein by patients with prostate cancer has been associated with decreased metastasis and mortality. Genistein blocks activation of p38 mitogen-activated protein kinase and thus inhibits matrix metalloproteinase-2 (MMP-2) expression and cell invasion in cultured cells and inhibits metastasis of human prostate cancer cells in mice. We investigated the target for genistein in prostate cancer cells.Prostate cell lines PC3-M, PC3, 1532NPTX, 1542NPTX, 1532CPTX, and 1542CPTX were used. All cell lines were transiently transfected with a constitutively active mitogen-activated protein kinase kinase 4 (MEK4) expression vector (to increase MEK4 expression), small interfering RNA against MEK4 (to decrease MEK4 expression), or corresponding control constructs. Cell invasion was assessed by a Boyden chamber assay. Gene expression was assessed by a quantitative reverse transcription-polymerase chain reaction. Protein expression was assessed by Western blot analysis. Modeller and AutoDock programs were used for modeling of the structure of MEK4 protein and ligand docking, respectively. MMP-2 transcript levels were assessed in normal prostate epithelial cells from 24 patients with prostate cancer from a phase II randomized trial comparing genistein treatment with no treatment. Statistical significance required a P value of .050 or less. All statistical tests were two-sided.Overexpression of MEK4 increased MMP-2 expression and cell invasion in all six cell lines. Decreased MEK4 expression had the opposite effects. Modeling showed that genistein bound to the active site of MEK4. Genistein inhibited MEK4 kinase activity with a half maximal inhibitory concentration of 0.40 microM (95% confidence interval [CI] = 0.36 to 0.45 muM). The MMP-2 transcript level in normal prostate epithelial cells was statistically significantly higher in the untreated group (100%) than in the genistein-treated group (24%; difference = 76%, 95% CI = 38% to 115%; P = .045).We identified MEK4 as a proinvasion protein in six human prostate cancer cell lines and the target for genistein. We showed, to our knowledge for the first time, that genistein treatment, compared with no treatment, was associated with decreased levels of MMP-2 transcripts in normal prostate cells from prostate cancer-containing tissue.

Although the functions of most of the identified microRNAs (miRNAs) have yet to be determined, their use as potential biomarkers has been considered in several human diseases and cancers. In order to understand their role in renal tumorigenesis, we screened the expression levels of miRNAs in four subtypes of human renal neoplasms: clear cell, papillary, and chromophobe renal cell carcinomas (RCC) as well as benign renal oncocytomas. We found a unique miRNA signature for each subtype of renal tumor. Furthermore, we identified unique patterns of miRNA expression distinguishing clear cell RCC cases with favorable vs. unfavorable outcome. Specifically, we documented the overexpression of miRs 424 and 203 in clear cell RCC relative to papillary RCC, as well as the inversion of expression of miR-203 in the benign oncocytomas (where it is underexpressed relative to normal kidney) as compared to the malignant chromophobe RCC (where it is overexpressed relative to normal kidney). Our results further suggest that overexpression of S-has-miR-32 is associated with poor outcome. While previous studies have identified unique miRNA expression pattern distinguishing tumors from different anatomical locations, here we extend this principle to demonstrate the utility of miRNA expression profiling to identify a signature unique to various tumor subtypes at a single anatomic locus.

We report an automated computer technique for detection of prostate cancer in prostate tissue sections processed with immunohistochemistry. Two sets of color optical images were acquired from prostate tissue sections stained with a double-chromogen triple-antibody cocktail combining alpha-methylacyl-CoA racemase, p63, and high-molecular-weight cytokeratin. The first set of images consisted of 20 training images (10 malignant) used for developing the computer technique and 15 test images (7 malignant) used for testing and optimizing the technique. The second set of images consisted of 299 images (114 malignant) used for evaluation of the performance of the computer technique. The computer technique identified image segments of alpha-methylacyl-CoA racemase-labeled malignant epithelial cells (red), p63, and high-molecular-weight cytokeratin-labeled benign basal cells (brown), and secretory and stromal cells (blue) for identifying prostate cancer automatically. The sensitivity and specificity of the computer technique were 94% (16/17) and 94% (17/18), respectively, on the first (training and test) set of images, and 88% (79/90) and 97% (136/140), respectively, on the second (validation) set of images. If high-grade prostatic intraepithelial neoplasia, which is a precursor of cancer, and atypical cases were included, the sensitivity and specificity were 85% (97/114) and 89% (165/185), respectively. These results show that the novel automated computer technique can accurately identify prostatic adenocarcinoma in the triple-antibody cocktail-stained prostate sections.

Studies have firmly established a key regulatory role for the tumor suppressor pVHL in the regulation of the vascular system and normal spermatogenesis. Here, we report that knockout of the newly identified tumor suppressor U19/Eaf2 also caused vascular system abnormalities and aspermatogenesis, suggesting a potential link between U19/Eaf2 and pVHL. Coimmunoprecipitation and in vitro binding assays showed an association between U19/Eaf2 and pVHL, whereas deletion mutagenesis revealed the requirement of the NH2 terminus of U19/Eaf2 and both the α and β domains of pVHL for this binding. U19/Eaf2 stabilizes pVHL, as shown by protein stability and pulse-chase studies. Testes and mouse embryonic fibroblasts (MEF) derived from U19/Eaf2 knockout mice expressed reduced levels of pVHL, indicating that full in vivo expression of pVHL indeed requires U19/Eaf2. As expected, U19/Eaf2 knockout MEF cells exhibited an increased level and activity of hypoxia-inducible factor 1α (HIF1α), a protein typically regulated via a pVHL-mediated degradation pathway. Furthermore, angiogenesis in a Matrigel plug assay was significantly increased in U19/Eaf2 knockout mice. The above observations argue that U19/Eaf2 can modulate HIF1α and angiogenesis, possibly via direct binding and stabilization of pVHL. [Cancer Res 2009;69(6):2599–606]

Prostate-specific membrane antigen (PSMA), a type II transmembrane metallo-peptidase highly overexpressed in prostate cancer cells, has been studied as a targeting molecule in prostate cancer. Recently, PSMA has also been found to be expressed in the neovasculature of multiple nonprostatic solid tumors. Because of its unique expression pattern limited to tumor-associated endothelial cells, PSMA may also be an interesting molecule for vascular targeting. In this study, PSMA expression was determined by immunohistochemistry in 119 cases of primary gastric adenocarcinoma, 130 cases of primary colorectal adenocarcinoma, and 24 metastasis of colorectal adenocarcinoma. Expression data were correlated with clinicopathologic information. PSMA expression was detected in tumor-associated neovasculature of 79 (66%) of 119 gastric and 110 (85%) of 130 colorectal carcinomas. Furthermore, the neovasculatures of 16 (84%) of 19 liver and 4 (80%) of 5 nodal metastases from colorectal carcinomas were prostate-specific membrane antigen positive. There was a trend for high-grade tumors to higher PSMA expression (Spearman r = 0.18, P = .046) in colorectal cancers. No association between PSMA expression and overall- or disease-free survival was observed in gastric or colorectal cancers. This study provides the first in-depth look at PSMA expression in gastric and colorectal cancer. Because of its highly tumor-restricted expression and its accessibility to targeted therapy, PSMA represents a promising therapeutic and diagnostic target in colorectal and gastric cancer.

Cholangiocarcinoma (CC) and hepatocellularcarcinoma (HCC) are two main forms of liver malignancies, which exhibit differences in drug response and prognosis. Immunohistotochemical staining for cytokeratin markers has been used to some success in the differential diagnosis of CC from HCC. However, there remains a need for additional markers for increased sensitivity and specificity of diagnosis. In this study, we have identified a p38 MAP kinase, p38delta (also known as MAPK13 or SAPK4) as a protein that is upregulated in CC relative to HCC and to normal biliary tract tissues. We performed microarray gene expression profiling on 17 cases of CC, 12 cases of adjacent normal liver tissue, and three case of normal bile duct tissue. p38delta was upregulated in 16 out of 17 cases of CC relative to normal tissue. We subsequently performed immunohistochemical staining of p38delta in 54 cases of CC and 54 cases of HCC. p38delta staining distinguished CC from HCC with a sensitivity of 92.6% and a specificity of 90.7%. To explore the possible functional significance of p38delta expression in CC, we examined the effects of overexpression and knockdown of p38delta expression in human CC cell lines. Our results indicate that p38delta is important for motility and invasion of CC cells, suggesting that p38delta may play an important role in CC metastasis. In summary, p38delta may serve as a novel diagnostic marker for CC and may also serve as a new target for molecular based therapy of this disease.