Novel DSP Spectrin 6 Region Variant Causes Neonatal Erythroderma, Failure to Thrive, Severe Herpes Simplex Infections and Brain Lesions.

Desmoplakin (DSP) and Desmoglein 1 (DSG1) variants result in skin barrier defects leading to erythroderma, palmoplantar keratoderma and variable [AQ4] other features. Some DSG1 variant carriers present with SAM syndrome (Severe dermatitis, multiple Allergies, Metabolic wasting) and a SAM-like phenotype has been reported in 4 subjects with different heterozygous DSP variants. We report here a patient with a novel DSP spectrin region (SR) 6 variant c.1756C>T, p.(His586Tyr), novel features of brain lesions and severe recurrent mucocutaneous herpes simplex virus infections, with a favourable response to ustekinumab. Through a review of reported cases of heterozygous variants in DSP SR6 (n = 15) and homozygous or compound heterozygous variants in DSG1 (n = 12) and SAM-like phenotype, we highlight phenotypic variability. Woolly hair, nail abnormalities and cardiomyopathy characterize patients with DSP variants, while elevated immunoglobulin E and food allergies are frequent in patients with DSG1 variants. Clinicians should be aware of the diverse manifestations of desmosomopathies.

Multiple scattering of light in discrete random media using incoherent interactions.

We consider the scattering and absorption of light in discrete random media of densely packed spherical particles. In what we term "radiative transfer with reciprocal transactions" (R2T2), we introduce a volume element of the random medium, derive its scattering and absorption characteristics using the superposition T-Matrix method (STMM), and compute its frequency-domain incoherent volume-element scattering characteristics. Using an order-of-scattering approach, we then compute a numerical Monte Carlo solution for the scattering problem with an exact treatment of the interaction between two volume elements. We compute both the direct and reciprocal contributions along a sequence of volume elements, allowing us to evaluate the coherent backscattering effects. We show that the R2T2 and exact STMM solutions are in mutual agreement for large finite systems of densely packed spherical particles. We conclude that the R2T2 method provides a viable numerical solution for scattering by asymptotically infinite systems of particles.

Collagens XV and XVIII show different expression and localisation in cutaneous squamous cell carcinoma: type XV appears in tumor stroma, while XVIII becomes upregulated in tumor cells and lost from microvessels.

As the second most common skin malignancy, cutaneous squamous cell carcinoma (cSCC) is an increasing health concern, while its pathogenesis at molecular level remains largely unknown. We studied the expression and localisation of two homologous basement membrane (BM) collagens, types XV and XVIII, at different stages of cSCC. These collagens are involved in angiogenesis and tumorigenesis, but their role in cancer development is incompletely understood. Quantitative RT-PCR analysis revealed upregulation of collagen XVIII, but not collagen XV, in primary cSCC cells in comparison with normal human epidermal keratinocytes. In addition, the Ha-ras-transformed invasive cell line II-4 expressed high levels of collagen XVIII mRNA, indicating upregulation in the course of malignant transformation. Immunohistochemical analyses of a large human tissue microarray material showed that collagen XVIII is expressed by tumor cells from grade 1 onwards, while keratinocytes in normal skin and in premalignant lesions showed negative staining for it. Collagen XV appeared instead as deposits in the tumor stroma. Our findings in human cSCCs and in mouse cSCCs from the DMBA-TPA skin carcinogenesis model showed that collagen XVIII, but not collagen XV or the BM markers collagen IV or laminin, was selectively reduced in the tumor vasculature, and this decrease associated significantly with cancer progression. Our results demonstrate that collagens XV and XVIII are expressed in different sites of cSCC and may contribute in a distinct manner to processes related to cSCC tumorigenesis, identifying these collagens as potential biomarkers in the disease.

The prognostic and predictive roles of plasma C-reactive protein and PD-L1 in non-small cell lung cancer.

BACKGROUND: Anti-PD-(L)1 agents have revolutionized the treatment paradigms of non-small cell lung cancer (NSCLC), while predictive biomarkers are limited. It has been previously shown that systemic inflammation, indicated by elevated C-reactive protein (CRP) level, is associated with a poor prognosis in anti-PD-(L)1 treated. The aim of the study was to analyze the prognostic and predictive value of CRP in addition to traditional prognostic and predictive markers and tumor PD-L1 score. METHODS: We identified all NSCLC patients (n = 329) who had undergone PD-L1 tumor proportion score (TPS) analysis at Oulu University Hospital 2015-22. CRP levels, treatment history, immune checkpoint inhibitor (ICI) therapy details, and survival were collected. The patients were categorized based on CRP levels (≤10 vs. >10) and PD-L1 TPS scores (<50 vs. ≥50). RESULTS: In the whole cohort (n = 329), CRP level of ≤10 mg/L was associated with improved survival in univariate (HR 0.30, Cl 95% 0.22-0.41) and multivariate analyzes (HR 0.44, CI 95% 0.28-0.68). With ICI treated (n = 70), both CRP of ≤10 and PD-L1 TPS of ≥50 were associated with improved progression-free survival (PFS) in univariate (HR 0.51, CI 95% 0.27-0.96; HR 0.54, CI 95% 0.28-1.02) and multivariate (HR 0.48, CI 95% 0.26-0.90; HR 0.50, CI 95% 0.26-0.95) analyzes. The combination (PD-L1 TPS ≥50 and CRP >10) carried a high negative predictive value with a median PFS of 4.11 months (CI 95% 0.00-9.63), which was similar to patients with low PD-L1 (4.11 months, CI 95% 2.61-5.60). CONCLUSIONS: Adding plasma CRP levels to PD-L1 TPS significantly increased the predictive value of sole PD-L1. Furthermore, patients with high CRP beard little benefit from anti-PD-(L)1 therapies independent of PD-L1 score. The study highlights the combined evaluation of plasma CRP and PD-L1 TPS as a negative predictive marker for ICI therapies.

Targeting collagen XVIII improves the efficiency of ErbB inhibitors in breast cancer models.

The tumor extracellular matrix (ECM) critically regulates cancer progression and treatment response. Expression of the basement membrane component collagen XVIII (ColXVIII) is induced in solid tumors, but its involvement in tumorigenesis has remained elusive. We show here that ColXVIII was markedly upregulated in human breast cancer (BC) and was closely associated with a poor prognosis in high-grade BCs. We discovered a role for ColXVIII as a modulator of epidermal growth factor receptor tyrosine kinase (ErbB) signaling and show that it forms a complex with ErbB1 and -2 (also known as EGFR and human epidermal growth factor receptor 2 [HER2]) and α6-integrin to promote cancer cell proliferation in a pathway involving its N-terminal portion and the MAPK/ERK1/2 and PI3K/AKT cascades. Studies using Col18a1 mouse models crossed with the mouse mammary tumor virus-polyoma virus middle T antigen (MMTV-PyMT) mammary carcinogenesis model showed that ColXVIII promoted BC growth and metastasis in a tumor cell-autonomous manner. Moreover, the number of mammary cancer stem cells was significantly reduced in the MMTV-PyMT and human cell models upon ColXVIII inhibition. Finally, ablation of ColXVIII substantially improved the efficacy of ErbB-targeting therapies in both preclinical models. In summary, ColXVIII was found to sustain the stemness properties of BC cells and tumor progression and metastasis through ErbB signaling, suggesting that targeting ColXVIII in the tumor milieu may have important therapeutic potential.

SISPO: Space Imaging Simulator for Proximity Operations.

This paper describes the architecture and demonstrates the capabilities of a newly developed, physically-based imaging simulator environment called SISPO, developed for small solar system body fly-by and terrestrial planet surface mission simulations. The image simulator utilises the open-source 3-D visualisation system Blender and its Cycles rendering engine, which supports physically based rendering capabilities and procedural micropolygon displacement texture generation. The simulator concentrates on realistic surface rendering and has supplementary models to produce realistic dust- and gas-environment optical models for comets and active asteroids. The framework also includes tools to simulate the most common image aberrations, such as tangential and sagittal astigmatism, internal and external comatic aberration, and simple geometric distortions. The model framework's primary objective is to support small-body space mission design by allowing better simulations for characterisation of imaging instrument performance, assisting mission planning, and developing computer-vision algorithms. SISPO allows the simulation of trajectories, light parameters and camera's intrinsic parameters.

Multi-center real-world comparison of the fully automated Idylla™ microsatellite instability assay with routine molecular methods and immunohistochemistry on formalin-fixed paraffin-embedded tissue of colorectal cancer.

Microsatellite instability (MSI) is present in 15-20% of primary colorectal cancers. MSI status is assessed to detect Lynch syndrome, guide adjuvant chemotherapy, determine prognosis, and use as a companion test for checkpoint blockade inhibitors. Traditionally, MSI status is determined by immunohistochemistry or molecular methods. The Idylla™ MSI Assay is a fully automated molecular method (including automated result interpretation), using seven novel MSI biomarkers (ACVR2A, BTBD7, DIDO1, MRE11, RYR3, SEC31A, SULF2) and not requiring matched normal tissue. In this real-world global study, 44 clinical centers performed Idylla™ testing on a total of 1301 archived colorectal cancer formalin-fixed, paraffin-embedded (FFPE) tissue sections and compared Idylla™ results against available results from routine diagnostic testing in those sites. MSI mutations detected with the Idylla™ MSI Assay were equally distributed over the seven biomarkers, and 84.48% of the MSI-high samples had ≥ 5 mutated biomarkers, while 98.25% of the microsatellite-stable samples had zero mutated biomarkers. The concordance level between the Idylla™ MSI Assay and immunohistochemistry was 96.39% (988/1025); 17/37 discordant samples were found to be concordant when a third method was used. Compared with routine molecular methods, the concordance level was 98.01% (789/805); third-method analysis found concordance for 8/16 discordant samples. The failure rate of the Idylla™ MSI Assay (0.23%; 3/1301) was lower than that of referenced immunohistochemistry (4.37%; 47/1075) or molecular assays (0.86%; 7/812). In conclusion, lower failure rates and high concordance levels were found between the Idylla™ MSI Assay and routine tests.

Expression of toll-like receptor-9 is increased in poorly differentiated prostate tumors.

BACKGROUND: Toll-like receptor-9 (TLR9) is a cellular receptor for bacterial and vertebrate DNA. In addition to cells of the immune system, it is also expressed in various human cancer cell lines, including prostate cancer. We demonstrated previously that synthetic TLR9 ligands induce matrix metalloproteinase-13-mediated invasion in TLR9-expressing prostate cancer cells in vitro. Other studies have suggested possible sex steroid regulation of the function of the various TLRs. The role of TLR9 in the pathophysiology of prostate or any cancer is, however, unknown. METHODS: Expression of TLR9, androgen receptor (AR), or the estrogen receptors alpha (ERalpha) and beta (ERbeta) were studied with immunohistochemistry in prostate cancer (n = 62) and benign prostatic hyperplasia (n = 45) specimens. TLR9 staining scores were compared with tumor stage, Gleason score, prostate-specific antigen (PSA) concentrations before tissue sampling and with the staining scores of AR, ERalpha, and ERbeta. RESULTS: TLR9 expression was statistically significantly increased in prostate cancer epithelium and stroma, as compared with the same cellular compartments in benign hyperplasia. Significantly increased (P = 0.04) TLR9 expression was detected in cancers with high Gleason score (>7, n = 23), as compared with lower Gleason scores (< or =7, n = 39). No statistically significant associations were detected between TLR9 expression scores and PSA concentrations or tumor staging. Prostate adenocarcinoma cells were all positive for TLR9, AR, and ERbeta but negative for ERalpha expression. In cancer stroma cells, increased TLR9 expression was associated with increased ERalpha expression. CONCLUSIONS: Expression of TLR9 is increased in prostate cancer specimens, especially in the most poorly differentiated forms.

Myosin VI is a modulator of androgen-dependent gene expression.

Myosin VI, one of the so-called unconventional myosins, is an actin-based molecular motor involved in intracellular vesicle and organelle transport. In human prostate, myosin VI is expressed in prostate epithelium. We examined the effect of myosin VI downregulation in the LNCaP human prostate cancer cell line using an RNA interference approach. Further, the expression of myosin VI in human prostate tissue was examined using immunohistochemistry. The expression of androgen receptor (AR) and E-cadherin was examined in myosin VI knocked-down cells and control cells. We determined 3H-testosterone uptake in the myosin knocked-down LNCaP cells. Next, we cotransfected LNCaP cells with the myosin VI-specific small interfering RNA (siRNA) duplex and an androgen-responsive luciferase reporter construct and then measured luciferase activity after androgen induction. To clarify whether myosin VI and the AR are interacting proteins, we performed immunoprecipitation studies using myosin VI and AR polyclonal antibodies in androgen-induced LNCaP cells. We confirmed previous results of myosin VI overexpression in human prostate cancer tissue, as in some cases malignant epithelium was more intensively stained than benign epithelium. We found that the expression of AR decreased as a result of myosin VI knock-down. Decreased myosin VI levels did not significantly influence the testosterone uptake of the LNCaP cell line. Instead, we noted a decreased activity of the androgen-regulated mouse mammary tumor virus promoter-reporter vector construct in LNCaP cells cotransfected with myosin VI siRNA duplexes. Finally, we detected the interaction between AR and myosin VI by immunoprecipitation. We propose that myosin VI is a modulator of androgen-dependent gene transcription via interaction with the AR. Thus, myosin VI is a potential therapeutic target for prostate cancer as it could be used as a modulator of AR-dependent gene expression.

Radiative transfer with reciprocal transactions: Numerical method and its implementation.

We present a numerical method for solving electromagnetic scattering by dense discrete random media entitled radiative transfer with reciprocal transactions (R2T2). The R2T2 is a combination of the Monte Carlo radiative-transfer, coherent-backscattering, and superposition T-matrix methods. The applicability of the radiative transfer is extended to dense random media by incorporating incoherent volume elements containing multiple particles. We analyze the R2T2 by comparing the results with the asymptotically exact superposition T-matrix method, and show that the R2T2 removes the caveats of radiative-transfer methods by comparing it to the RT-CB. We study various implementation choices that result in an accurate and efficient numerical algorithm. In particular, we focus on the properties of the incoherent volume elements and their effects on the final solution.

Increased mesenchymal podoplanin expression is associated with calcification in aortic valves.

BACKGROUND AND AIM OF THE STUDY: Calcific aortic valve disease (CAVD) is a progressive disease starting from mild valvular sclerosis and progressing to severe aortic stenosis (AS) with calcified valves. The origin of the calcification is proposed to be mesenchymal cells which have differentiated towards an osteoblastic phenotype. Podoplanin is a glycoprotein expressed in the endothelium of lymphatic vessels and in osteoblasts and osteocytes, mesenchymal cells, as well as in many carcinomas and aortic atherosclerotic lesions. In CAVD, its expression has been evaluated only as a marker of the lymphatic vasculature. MATERIALS AND METHODS: We determined podoplanin expression in human aortic valves in four patient groups: control (C, n=7), aortic regurgitation (AR, n=8), aortic regurgitation and fibrosis (AR + f, n=15) and AS (n=49) by immunohistochemistry and quantitative real-time PCR (RT-PCR). RESULTS: Immunohistochemically, podoplanin expression was significantly increased in AR + f and AS groups when compared with the control and AR groups and the level of expression positively correlated with the extent of calcification and vascularity. Podoplanin mRNA levels were 1.7-fold higher in the AS group as compared with the control group (P=.05). Podoplanin-positivity was present not only in lymphatic vessel endothelium but also in osteoblasts, osteocytes, chondrocytes, macrophages and extracellular matrix. The majority of the podoplanin-positivity was in spindle cells with a myofibroblastic phenotype, often associated with calcifications. Tricuspid valves had more calcification-associated podoplanin than bi/unicuspid valves (median 1.52 vs 1.16, P<.001). CONCLUSIONS: CAVD is characterized by an increased expression of podoplanin; this is associated with the differentiation of valvular interstitial cells into calcium-producing, myofibroblast-like cells. In addition, tricuspid valves express relatively more podoplanin than bi/unicuspid valves.

Scattering And Absorption of Light in Planetary Regoliths.

Theoretical, numerical, and experimental methods are presented for multiple scattering of light in macroscopic discrete random media of densely-packed microscopic particles. The theoretical and numerical methods constitute a framework of Radiative Transfer with Reciprocal Transactions (R2T2). The R2T2 framework entails Monte Carlo order-of-scattering tracing of interactions in the frequency space, assuming that the fundamental scatterers and absorbers are wavelength-scale volume elements composed of large numbers of randomly distributed particles. The discrete random media are fully packed with the volume elements. For spherical and nonspherical particles, the interactions within the volume elements are computed exactly using the Superposition T-Matrix Method (STMM) and the Volume Integral Equation Method (VIEM), respectively. For both particle types, the interactions between different volume elements are computed exactly using the STMM. As the tracing takes place within the discrete random media, incoherent electromagnetic fields are utilized, that is, the coherent field of the volume elements is removed from the interactions. The experimental methods are based on acoustic levitation of the samples for non-contact, non-destructive scattering measurements. The levitation entails full ultrasonic control of the sample position and orientation, that is, six degrees of freedom. The light source is a laser-driven white-light source with a monochromator and polarizer. The detector is a mini-photomultiplier tube on a rotating wheel, equipped with polarizers. The R2T2 is validated using measurements for a mm-scale spherical sample of densely-packed spherical silica particles. After validation, the methods are applied to interpret astronomical observations for asteroid (4) Vesta and comet 67P/Churyumov-Gerasimenko (Figure 1) recently visited by the NASA Dawn mission and the ESA Rosetta mission, respectively.

The shed ectodomain of type XIII collagen associates with the fibrillar fibronectin matrix and may interfere with its assembly in vitro.

Type XIII collagen is a transmembrane collagen, which is known to exist also as a soluble variant due to ectodomain shedding. Earlier studies with the recombinant ectodomain have shown it to interact in vitro with a number of extracellular matrix proteins, e.g. Fn (fibronectin). In view of its strong binding to Fn, we examined in the present study whether the released soluble ectodomain can bind to the fibrillar Fn matrix under cell-culture conditions and, if so, influence its assembly. In this study, we demonstrate that the type XIII collagen ectodomain of mammalian cells can associate with Fn fibres and may eventually hamper incorporation of the fibrillar Fn meshwork. The association between type XIII collagen and Fn was implicated to be mediated by the C-terminal end of type XIII collagen and the N-terminal end of Fn. The results presented here imply that the shedding of the type XIII collagen ectodomain results in a biologically active molecule capable of remodelling the structure of the pericellular matrix.

Notch Downregulation and Extramedullary Erythrocytosis in Hypoxia-Inducible Factor Prolyl 4-Hydroxylase 2-Deficient Mice.

Erythrocytosis is driven mainly by erythropoietin, which is regulated by hypoxia-inducible factor (HIF). Mutations in HIF prolyl 4-hydroxylase 2 (HIF-P4H-2) (PHD2/EGLN1), the major downregulator of HIFα subunits, are found in familiar erythrocytosis, and large-spectrum conditional inactivation of HIF-P4H-2 in mice leads to severe erythrocytosis. Although bone marrow is the primary site for erythropoiesis, spleen remains capable of extramedullary erythropoiesis. We studied HIF-P4H-2-deficient (Hif-p4h-2gt/gt) mice, which show slightly induced erythropoiesis upon aging despite nonincreased erythropoietin levels, and identified spleen as the site of extramedullary erythropoiesis. Splenic hematopoietic stem cells (HSCs) of these mice exhibited increased erythroid burst-forming unit (BFU-E) growth, and the mice were protected against anemia. HIF-1α and HIF-2α were stabilized in the spleens, while the Notch ligand genes Jag1, Jag2, and Dll1 and target Hes1 became downregulated upon aging HIF-2α dependently. Inhibition of Notch signaling in wild-type spleen HSCs phenocopied the increased BFU-E growth. HIFα stabilization can thus mediate non-erythropoietin-driven splenic erythropoiesis via altered Notch signaling.

Altered expression of type XIII collagen in keratoconus and scarred human cornea: Increased expression in scarred cornea is associated with myofibroblast transformation.

PURPOSE: Type XIII collagen (ColXIII) is a transmembrane protein thought to be involved in cell-cell and cell-matrix interactions. We report here on its presence in the normal human cornea and compare the results for keratoconus and scarred corneas. METHODS: Immunohistochemistry and in situ hybridization were applied to human corneal samples obtained by penetrating keratoplasty. RESULTS: In the normal human cornea, ColXIII was immunolocalized to the corneal epithelial cells, and to a lesser degree to the stromal keratocytes. The keratoconus cases showed otherwise similar results, but in areas containing Bowman membrane disruptions showed thinned epithelial cells reduced immunostaining for ColXIII, whereas occasionally pronounced immunoreactivity was seen in the stromal keratocytes. The corneal scar samples contained highly increased ColXIII immunostaining by stromal cells in the fibrotic foci, whereas the peripheral areas showed less intense immunostaining. In situ hybridization confirmed that the corneal epithelium and keratocytes actively synthesize the transcript. Immunostaining with alphaSMA revealed that a substantial proportion of the ColXIII mRNA-expressing cells in the stromal scar tissues was myofibroblasts and that these areas lack CD34 immunoreactivity. CONCLUSIONS: The results indicate that ColXIII, which is predominantly confined to the basal corneal cells in the normal cornea, may have a role in the adhesion of corneal epithelial cells to each other and to the underlying basement membrane. Additionally, highly increased expression in scarred corneas suggests that it participates in the corneal wound healing process.

The shed ectodomain of type XIII collagen affects cell behaviour in a matrix-dependent manner.

Transmembrane type XIII collagen resides in adhesive structures of cells and tissues, and has therefore been implicated in cell adhesion and in adhesion-dependent cell functions. This collagen also exists as a soluble protein in the pericellular matrix, as the ectodomain is released from the plasma membrane by proteolytic cleavage. Analysis with various protease inhibitors led to confirmation of the furin family of proprotein convertases as the protease group responsible for the shedding of the ectodomain, cleaving at a site conforming to the consensus sequence for the proprotein convertases at the stem of the ectodomain. Both the trans -Golgi network and the plasma membrane were used as cleavage locations. Mammalian cells employed various intracellular mechanisms to modulate shedding of the ectodomain, all resulting in a similar cleavage event. Cell detachment from the underlying substratum was also found to augment the excision. The released ectodomain rendered the pericellular surroundings less supportive of cell adhesion, migration and proliferation, as seen specifically on a vitronectin substratum. Type XIII collagen ectodomain shedding thus resulted in the formation of a soluble, biologically active molecule, which eventually modulated cell behaviour in a reciprocal and substratum-specific manner. The dual existence of membrane-bound and soluble variants widens our biological understanding of type XIII collagen.

Developmentally regulated expression of type XV collagen correlates with abnormalities in Col15a1(-/-) mice.

Lack of type XV collagen in mice results in mild skeletal myopathy and increases vulnerability to exercise-induced skeletal muscle and cardiac injury [Proc. Natl. Acad. Sci. USA 98 (2001), 1194]. The expression of type XV collagen was studied during murine fetal development from 10.5 to 18.5 dpc using immunofluorescence. The first sign of type expression was seen in the capillaries of many tissues at 10.5 dpc, some of them showing developmental transitions in the expression. Interestingly, capillaries forming the blood-brain barrier and those of the sinusoidal type were essentially lacking in this collagen. Early expression was also detected in the skeletal muscle and peripheral nerves, while expression in the heart, kidney and lung appeared to be developmentally regulated. In addition, distinct staining was found in the perichondrium of the cartilage. Collectively, the dynamics of its expression during development, its localization in the basement membrane--fibrillar matrix interface and the consequences of its absence in mice suggest a structural role in providing stability at least in skeletal muscle and capillaries. The early prominent expression of type XV collagen in newly forming blood vessels could also indicate a possible role in angiogenic processes.

Activity of mesenchymal stem cells in a nonperfused cardiac explant model.

Stem cell therapy represents a potential novel additional therapy for acute myocardial infarction. Cardiac applications of stem cell therapy are now undergoing clinical trials though many properties, including localization, possible adhesion, and infiltration of the injected stem cells in the myocardium, have not been studied in detail even in vitro. To study these mechanisms in a controlled microenvironment, we developed a model where mesenchymal stem cells (MSCs) were transported into live, cultured cardiac explants for further co-culture. About 10×10(3) porcine MSCs were injected into freshly excised and isolated cardiac explants of the pig. The explants were present in the culture medium for up to 7 days, with the time course of viability of the myocardial tissue, and the migration and the localization of the injected MSCs were analyzed with histological and immunohistological stainings. The myocyte structure was observed to be well preserved, and proliferation of capillaries and myofibroblasts was detected at the explant periphery. There were injected MSCs localized in the capillaries and in contact with the endothelial cells. The migration range and the number of adherent MSCs increased over time, suggesting active movement of MSCs in the explant. Our results suggest that this cardiac explant culture model is a feasible method for studying the effects of stem cells in the myocardium in vitro.

Sorbitol dehydrogenase expression is regulated by androgens in the human prostate.

Sorbitol is an intermediate in the polyol pathway, which converts from glucose to fructose by sorbitol dehydrogenase (SORD). Androgens are essential for the development of prostate cancer. We studied castration-induced gene expression changes in the human prostate using the GeneChip array, and identified SORD as being androgen-regulated in the human prostate. A putative androgen-responsive regulatory region at the SORD 5' promoter was identified using promoter deletion constructs in a luciferase reporter assay in COS-7 cells. Chromatin immunoprecipitation assay was used to assess the binding of androgen receptor to suggested androgen responsive regulatory region. Finally, the expression of SORD in the human prostate was evaluated in 29 prostate tissue samples by immunohistochemistry. The expression of SORD decreased after castration. Androgen supplementation to the LNCaP prostate cancer cell line led to a 7.5-fold increase in SORD mRNA expression. Furthermore, a chromatin immunoprecipitation assay proved that the androgen receptor can bind to this putative androgen-responsive regulatory region. Finally, the expression of SORD in the human prostate was localised to epithelial cells of both benign and malignant prostate tissue by immunohistochemistry. In prostate cancer, increased immunostaining was associated with high Gleason patterns and high serum prostate-specific antigen concentrations. These results show that SORD is a novel androgen-regulated gene in the human prostate and suggest the need for more detailed analysis of the physiological role of SORD in the prostate.