Adeboye O. Osunkoya

An Inherited Heteroplasmic Mutation in Mitochondrial Gene COI in a Patient with Prostate Cancer Alters Reactive Oxygen, Reactive Nitrogen and Proliferation

Mitochondrial DNA (mtDNA) mutations have been found in many cancers but the physiological derangements caused by such mutations have remained elusive. Prostate cancer is associated with both inherited and somatic mutations in the cytochrome c oxidase (COI) gene. We present a prostate cancer patient-derived rare heteroplasmic mutation of this gene, part of mitochondrial respiratory complex IV. Functional studies indicate that this mutation leads to the simultaneous decrease in cytochrome oxidation, increase in reactive oxygen, and increased reactive nitrogen. These data suggest that mitochondrial DNA mutations resulting in increased reactive oxygen and reactive nitrogen generation may be involved in prostate cancer biology.

Insulin-like Growth Factor-I–Dependent Up-regulation of ZEB1 Drives Epithelial-to-Mesenchymal Transition in Human Prostate Cancer Cells

The epithelial-to-mesenchymal transition (EMT) is crucial for the migration and invasion of many epithelial tumors, including prostate cancer. Although it is known that ZEB1 overexpression promotes EMT primarily through down-regulation of E-cadherin in a variety of cancers, the soluble ligands responsible for the activation of ZEB1 have yet to be identified. In the present study, we investigated the role of insulin-like growth factor-I (IGF-I) in the regulation of ZEB1 during EMT associated with prostate tumor cell migration. We found that ZEB1 is expressed in highly aggressive prostate cancer cells and that its expression correlates directly with Gleason grade in human prostate tumors (P < 0.001). IGF-I up-regulates ZEB1 expression in prostate cancer cells exhibiting an epithelial phenotype. In prostate cancer cells displaying a mesenchymal phenotype, ZEB1 inhibition reverses the suppression of E-cadherin protein and down-regulates the expression of the mesenchymal markers N-cadherin and fibronectin. Furthermore, ZEB1 blockade decreases migratory and invasive potential in ARCaP(M) compared with the control. These results identify ZEB1 as a key transcriptional regulator of EMT in prostate cancer and suggest that the aberrant expression of ZEB1 in prostate cancer cells occurs in part in response to IGF-I stimulation.

Molecular Mapping of Tumor Heterogeneity on Clinical Tissue Specimens with Multiplexed Quantum Dots

Tumor heterogeneity is one of the most important and challenging problems not only in studying the mechanisms of cancer development but also in developing therapeutics to eradicate cancer cells. Here we report the use of multiplexed quantum dots (QDs) and wavelength-resolved spectral imaging for molecular mapping of tumor heterogeneity on human prostate cancer tissue specimens. By using a panel of just four protein biomarkers (E-cadherin, high-molecular-weight cytokeratin, p63, and alpha-methylacyl CoA racemase), we show that structurally distinct prostate glands and single cancer cells can be detected and characterized within the complex microenvironments of radical prostatectomy and needle biopsy tissue specimens. The results reveal extensive tumor heterogeneity at the molecular, cellular, and architectural levels, allowing direct visualization of human prostate glands undergoing structural transitions from a double layer of basal and luminal cells to a single layer of malignant cells. For clinical diagnostic applications, multiplexed QD mapping provides correlated molecular and morphological information that is not available from traditional tissue staining and molecular profiling methods.

XMRV infection in patients with prostate cancer: novel serologic assay and correlation with PCR and FISH.

OBJECTIVES To develop a serum-based assay to detect neutralizing antibodies to the xenotropic murine leukemia virus-related virus (XMRV) retrovirus and to use this assay with polymerase chain reaction and fluorescence in situ hybridization to identify patients with prostate cancer previously exposed to XMRV infection and those who carry XMRV viral sequences in their prostate. METHODS Patients who had undergone radical prostatectomy were enrolled, and biologic specimens were obtained at surgery. The patients were genotyped for the R462Q RNASEL variant using a TaqMan genotyping assay on DNA from the peripheral blood. A serum assay that detects XMRV neutralizing antibodies was developed and used to determine which patients had serologic evidence of previous infection with XMRV virus. Some of these patients were also tested for the presence of XMRV nucleotide sequences in their prostate using polymerase chain reaction and fluorescence in situ hybridization analysis. RESULTS At a serum dilution of 1:150, our assay detected 11 (27.5%) of 40 patients with XMRV neutralizing antibodies, including 8 (40%) of 20 with the RNASEL genotype QQ and 3 (15%) of 20 with either the RQ or RR genotype. These results were in complete concordance with 2 other assays (polymerase chain reaction and fluorescence in situ hybridization), which were designed to detect XMRV infection. CONCLUSIONS XMRV infects some patients with prostate cancer. Neutralizing antibodies against XMRV correlated with 2 independent methods of detecting the virus in the prostate. The antibody response suggests that with clinical serologic assay development, it might be possible to screen patients for XMRV infection. The cases presented in the present report provided biologic samples that can be used for the development of a clinically relevant assay.

Hyperspectral imaging and quantitative analysis for prostate cancer detection

Hyperspectral imaging (HSI) is an emerging modality for various medical applications. Its spectroscopic data might be able to be used to noninvasively detect cancer. Quantitative analysis is often necessary in order to differentiate healthy from diseased tissue. We propose the use of an advanced image processing and classification method in order to analyze hyperspectral image data for prostate cancer detection. The spectral signatures were extracted and evaluated in both cancerous and normal tissue. Least squares support vector machines were developed and evaluated for classifying hyperspectral data in order to enhance the detection of cancer tissue. This method was used to detect prostate cancer in tumor-bearing mice and on pathology slides. Spatially resolved images were created to highlight the differences of the reflectance properties of cancer versus those of normal tissue. Preliminary results with 11 mice showed that the sensitivity and specificity of the hyperspectral image classification method are 92.8% to 2.0% and 96.9% to 1.3%, respectively. Therefore, this imaging method may be able to help physicians to dissect malignant regions with a safe margin and to evaluate the tumor bed after resection. This pilot study may lead to advances in the optical diagnosis of prostate cancer using HSI technology.

ANOs 3-7 in the anoctamin/Tmem16 Cl- channel family are intracellular proteins.

Ca(2+)-activated Cl(-) channels (CaCCs) participate in numerous physiological functions such as neuronal excitability, sensory transduction, and transepithelial fluid transport. Recently, it was shown that heterologously expressed anoctamins ANO1 and ANO2 generate currents that resemble native CaCCs. The anoctamin family (also called Tmem16) consists of 10 members, but it is not known whether all members of the family are CaCCs. Expression of ANOs 3-7 in HEK293 cells did not generate Cl(-) currents activated by intracellular Ca(2+), as determined by whole cell patch clamp electrophysiology. With the use of confocal imaging, only ANO1 and ANO2 traffic to the plasma membrane when expressed heterologously. Furthermore, endogenously expressed ANO7 in the human prostate is predominantly intracellular. We took a chimeric approach to identify regions critical for channel trafficking and function. However, none of the chimeras of ANO1 and ANO5/7 that we made trafficked to the plasma membrane. Our results suggest that intracellular anoctamins may be endoplasmic reticulum proteins, although it remains unknown whether these family members are CaCCs. Determining the role of anoctamin family members in ion transport will be critical to understanding their functions in physiology and disease.

Tuberous sclerosis-associated renal cell carcinoma: a clinicopathologic study of 57 separate carcinomas in 18 patients.

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder with characteristic tumors involving multiple organ systems. Whereas renal angiomyolipoma (AML) is common in TSC, renal cell carcinoma (RCC) is rarely reported. Fifty-seven RCCs from 13 female and 5 male TSC patients were reviewed. Age at surgery ranged from 7 to 65 years (mean: 42 y). Nine patients (50%) had multiple synchronous and/or metachronous RCCs (range of 2 to 20 RCCs) and 5 had bilateral RCCs (28%). Seventeen patients (94%) had histologically confirmed concurrent renal AMLs, including 15 with multiple AMLs (88%) and 9 (50%) with AMLs with epithelial cysts. None of the 15 patients with available clinical follow-up information had evidence of distant metastatic disease from 6 to 198 months after their initial surgery (mean: 52 mo). The 57 RCCs exhibited 3 major distinct morphologies: (1) 17 RCCs (30%) had features similar to tumors previously described as “renal angiomyoadenomatous tumor” or “RCC with smooth muscle stroma”; (2) 34 RCCs (59%) showed features similar to chromophobe RCC; and (3) 6 RCCs (11%) showed a granular eosinophilic-macrocystic morphology. Distinct histologic changes were also commonly present in the background kidney parenchyma and included cysts or renal tubules lined by epithelial cells with prominent eosinophilic cytoplasm, nucleomegaly, and nucleoli. Immunohistochemically, all RCCs tested showed strong nuclear reactivity for PAX8 and HMB45 negativity. Compared with sporadic RCCs, TSC-associated RCCs have unique clinicopathologic features including female predominance, younger age at diagnosis, multiplicity, association with AMLs, 3 recurring histologic patterns, and an indolent clinical course. Awareness of the morphologic and clinicopathologic spectrum of RCC in this setting will allow surgical pathologists to better recognize clinically unsuspected TSC patients.

Plasmacytoid urothelial carcinoma: detailed analysis of morphology with clinicopathologic correlation in 17 cases.

The plasmacytoid variant of urothelial carcinoma is rare, of which less than 40 cases have been reported in the English language literature. Herein we report the largest series to date of 17 cases of urothelial carcinoma with plasmacytoid features and report the associated clinicopathologic findings. The architectural pattern of the tumor varied from cells arranged in cords and single cells (35%), small nests (17%), solid sheetlike growth (29%), and diffuse discohesive patternless architecture (23%). The plasmacytoid component varied from 15% to 100% of the specimen analyzed; in 12 cases the plasmacytoid component composed greater than 50% of the tumor. The individual tumor cells had striking morphologic overlap with plasma cells with an eccentrically placed nucleus and abundant amphophilic to eosinophilic cytoplasm. The nuclei were of low to intermediate nuclear grade with minimal nuclear pleomorphism. Thirteen of 17 cases (76%) were associated with conventional high-grade invasive urothelial carcinoma and 9 cases showed very focal intracytoplasmic vacuoles mimicking signet ring cells. One case also showed sarcomatoid dedifferentiation. The tumor cells were positive for cytokeratin 7 (94%) and cytokeratin 20 (31%); CD138 was positive in 94% of cases. All cases were invasive—7 into at least the lamina propria, 7 into at least the muscularis propria, and 3 into perivesical fat. Follow-up information was available in 16 cases (range: 2 wk to 43 mo; mean 10 mo; median 5.5 mo). Eleven patients died of disease and 5 patients were alive with disease. Plasmacytoid variant of urothelial carcinoma is an aggressive subtype associated with poor prognosis. In limited samples, it may be misdiagnosed as chronic cystitis or plasmacytoma, a pitfall further compounded by CD138 expression. Distinction from metastatic carcinoma from other primary sites such as stomach and breast is critical due to differing therapeutic implications.

Aberrant Diffuse Expression of p63 in Adenocarcinoma of the Prostate on Needle Biopsy and Radical Prostatectomy: Report of 21 Cases

Aberrant diffuse expression of p63 in prostate carcinoma cells is a rare and poorly understood phenomenon. We studied 19 cases of prostate cancer with aberrant diffuse expression of p63 on needle biopsy and reviewed the subsequent radical prostatectomies in 6 cases. In 19/21 cases, 100% of the cancer nuclei stained intensely for p63, with 70% staining in the remaining 2 cases. Two additional radical prostatectomies with aberrant p63 staining with no needle biopsies available for review were also analyzed. On the hematoxylin and eosin-stained slides, 19/21 cases (90.5%) showed a distinctive morphology composed predominantly of glands, nests, and cords with atrophic cytoplasm, hyperchromatic nuclei, and visible nucleoli. Needle biopsy cases ranged from Gleason patterns 3 to 5 with tumor identified on one or more cores, ranging from a minute focus to 80% of the core. In all 8 radical prostatectomies p63 positive cancer was present, with in 2/8 cases both p63 positive cancer and usual p63 negative acinar prostate cancer. In all 8 cases, the tumors were organ confined with negative margins and there was no seminal vesicle involvement or lymph node metastasis. The presence of p63 positive atypical glands with an infiltrative pattern and perineural invasion on radical prostatectomy confirmed the needle biopsy diagnosis of carcinoma. Rarely, prostate cancer can aberrantly express diffuse p63 staining in a nonbasal cell distribution leading to the erroneous diagnosis of atrophy or atypical basal cell proliferation. The diagnosis of prostate cancer is based on the morphology and confirmed by the absence of high molecular weight cytokeratin staining and positivity for α-methylacyl-CoA racemase in the atypical glands. Pathologists need to be aware of this rare and unusual phenomenon, which is a potential pitfall in prostate cancer diagnosis.

LIV-1 Promotes Prostate Cancer Epithelial-to-Mesenchymal Transition and Metastasis through HB-EGF Shedding and EGFR-Mediated ERK Signaling

LIV-1, a zinc transporter, is an effector molecule downstream from soluble growth factors. This protein has been shown to promote epithelial-to-mesenchymal transition (EMT) in human pancreatic, breast, and prostate cancer cells. Despite the implication of LIV-1 in cancer growth and metastasis, there has been no study to determine the role of LIV-1 in prostate cancer progression. Moreover, there was no clear delineation of the molecular mechanism underlying LIV-1 function in cancer cells. In the present communication, we found increased LIV-1 expression in benign, PIN, primary and bone metastatic human prostate cancer. We characterized the mechanism by which LIV-1 drives human prostate cancer EMT in an androgen-refractory prostate cancer cells (ARCaP) prostate cancer bone metastasis model. LIV-1, when overexpressed in ARCaPE (derivative cells of ARCaP with epithelial phenotype) cells, promoted EMT irreversibly. LIV-1 overexpressed ARCaPE cells had elevated levels of HB-EGF and matrix metalloproteinase (MMP) 2 and MMP 9 proteolytic enzyme activities, without affecting intracellular zinc concentration. The activation of MMPs resulted in the shedding of heparin binding-epidermal growth factor (HB-EGF) from ARCaPE cells that elicited constitutive epidermal growth factor receptor (EGFR) phosphorylation and its downstream extracellular signal regulated kinase (ERK) signaling. These results suggest that LIV-1 is involved in prostate cancer progression as an intracellular target of growth factor receptor signaling which promoted EMT and cancer metastasis. LIV-1 could be an attractive therapeutic target for the eradication of pre-existing human prostate cancer and bone and soft tissue metastases.