Significance of Intratumoral Fibrosis in Clear Cell Renal Cell Carcinoma

BACKGROUND: Intratumoral fibrosis (ITF) is a frequent histologic finding in solid organ tumors. Renal cell carcinoma (RCC) is a highly vascularized tumor with different shapes and degrees of ITF and inflammation. ITF is a poor prognostic factor, especially in breast cancer, and is related to intratumoral necrosis (ITN) and intratumoral inflammation (ITI). However, the significance of ITF in RCC has not been fully studied. In this study, we evaluate the relationships between ITF and other clinicopathologic parameters associated with RCC prognosis. METHODS: ITF was evaluated in 204 clear cell renal cell carcinoma (CCRCC) specimens according to presence and grade of fibrosis, degree of ITI, and presence of ITN. Lysyl oxidase (LOX) expression in tumor cells was also evaluated with clinicopathologic parameters. RESULTS: Among 204 CCRCC cases, 167 (81.7%) showed ITF, 71 (34.8%) showed ITI, 35 (17.2%) showed ITN, and 111 (54.4%) showed LOX expression. ITF correlated with Fuhrman nuclear grade (p = .046), lymphovascular invasion (LVI) (p = .027), and ITN (p = .036). Patients with ITF had a poor five-year overall survival rate (p = .104). CONCLUSIONS: ITF is related to other poor prognostic factors in CCRCC, such as Fuhrman nuclear grade, ITN, and LVI, but ITF itself had no significant correlation with prognosis of CCRCC.

The Role of the Lysyl Oxidases in Tissue Repair and Remodeling: A Concise Review

Tissue injury provokes a series of events containing inflammation, new tissue formation and tissue remodeling which are regulated by the spatially and temporally coordinated organization. It is an evolutionarily conserved, multi-cellular, multi-molecular process via complex signalling network. Tissue injury disorders present grievous clinical prob-lems and are likely to increase since they are generally associated with the prevailing diseases such as diabetes, hyper-tension and obesity. Although these dynamic responses vary not only for the different types of trauma but also for the different organs, a balancing act between the tissue degradation and tissue synthesis is the same. In this process, the degradation of old extracellular matrix (ECM) elements and new ones' synthesis and deposition play an essential role, especially collagens. Lysyl oxidase (LOX) and four lysyl oxidase-like proteins are a group of enzymes capable of catalyzing cross-linking reaction of collagen and elastin, thus initiating the formation of covalent cross-links that insolubilize ECM proteins. In this way, LOX facilitates ECM stabilization through ECM formation, development, maturation and remodeling. This ability determines its potential role in tissue repair and regeneration. In this review, based on the current in vitro, animal and human in vivo studies which have shown the significant role of the LOXs in tissue repair, e.g., tendon regeneration, ligament healing, cutaneous wound healing, and cartilage remodeling, we focused on the role of the LOXs in inflammation phase, proliferation phase, and tissue remodeling phase of the repair process. By summarizing its healing role, we hope to shed light on the understanding of its potential in tissue repair and provide up to date therapeutic strategies towards related injuries.

A Novel Association between Lysyl Oxidase Gene Polymorphism and Intracranial Aneurysm in Koreans

PURPOSE: Lysyl oxidase (LOX) controls the cross-linking and maturation of elastin and collagen fibers. In this study, we investigated the association between LOX gene polymorphisms and intracranial aneurysm (IA) formation in a homogeneous Korean population. MATERIALS AND METHODS: This cross-sectional study involved 80 age-sex matched patients with IA and controls. Fisher's exact test was performed to analyze allelic associations between ten single nucleotide polymorphisms (SNPs) and IA, including 41 ruptured and 39 unruptured cases. Haplotype-specific associations were analyzed using the omnibus test estimating asymptotic chi-square statistics. RESULTS: Of ten SNPs, three SNPs (rs2303656, rs3900446, and rs763497) were significantly associated with IA (p<0.01). The C allele of rs3900446 was significantly related to increased IA risk with a significant threshold [odds ratio (OR)=20.15, p=4.8×10⁻⁵]. Meanwhile, the A allele of rs2303656 showed a preventive effect against IA formation (p=8.2×10⁻⁴). Seventeen of 247 haplotype structures showed a suggestive association with IA (asymptotic p<0.001). Of ten SNP haplotype combinations, the CG combination of rs3900446 and rs763497 reached Bonferroni-adjusted significant threshold in IA patients (minor haplotype frequency=0.113, asymptotic p=1.3×10⁻⁵). However, there was no association between aneurysm rupture and the LOX gene. CONCLUSION: This preliminary study indicated that LOX gene polymorphisms, such as rs2303656, rs3900446, and rs763497, may play crucial roles in IA formation in the Korean population. Our novel findings need to be validated in a large-scale independent population.

Función e importancia clínica de la enzima lisil-oxidasa / Role and clinical significance of the lysyl oxidase enzyme / Funções e importância clínicas da enzima lisil-oxidase

La lisil-oxidasa (LOX) es una quinoenzima que contiene cobre y lisil-tirosilquinona como cofactor. Esta amino-oxidasa actúa en la catálisis de la desaminación oxidativa de residuos de lisina en los precursores del colágeno y de elastina. Anteriormente se ha informado sobre su biosíntesis, sus propiedades catalíticas y mecanismo de reacción, cofactores e inhibidores, así como la expresión y respuesta a diversos efectores celulares. En este trabajo se analizan las funciones e implicancias clínicas de LOX ya que sus niveles aumentan en muchas enfermedades fibróticas y en algunos tumores, con lo que promueven metástasis, mientras que la expresión de la enzima está disminuida en enfermedades que involucran un deterioro en el metabolismo del cobre. LOX tiene funciones paradójicas en cáncer puesto que actúa tanto en la supresión como en la promoción tumoral. Se plantea su rol en la aterogénesis y la disfunción endotelial, en trastornos oculares, fibrosis, enfermedades iatrogénicas, regeneración ósea y aumento del riesgo de enfermedades cardiovasculares, entre otras. Se encaran los últimos avances referidos a la acción proangiogénica del cobre y las funciones de la proteína precursora de LOX, cuyos niveles de expresión están asociados con diversos tipos de cáncer.

Lysyl oxidase (LOX) is a copper-containing quinoenzyme, having lysyl-tyrosyl-quinone as cofactor. This amino oxidase catalyzes the oxidative deamination of lysine residues in collagen and elastin precursors. Its biosynthesis, catalytic properties and reaction mechanism, cofactors and inhibitors as well as expression and response to various cellular effectors have previously been reported. In the present paper, functions and clinical implications of LOX are analyzed, since LOX levels are increased in many fibrotic diseases, and in some tumors promoting metastasis, whereas the expression of the enzyme is decreased in diseases involving deterioration in copper metabolism. LOX shows paradoxical roles in cancer both suppressing and promoting tumors. The role of LOX in atherogenesis and endothelial dysfunction, eye disorders, fibrosis, iatrogenic diseases, bone regeneration, and increased risk of cardiovascular disease, among others, are addressed. Recent developments related to the proangiogenic action of copper and functions of LOX precursor protein, whose expression levels are associated with various cancers, are discussed.

A lisil oxidase (LOX) é uma quinoenzima contendo cobre e lisil-tirosil-quinona como cofator. Esta amino oxidase atua na catálise da desaminação oxidativa de resíduos de lisina de precursores de colágeno e elastina. Anteriormente foi informado sobre sua biossíntese, suas propriedades catalíticas e mecanismo de reação, cofatores e inibidores, bem como a expressão e resposta a vários efetores celulares. Neste trabalho as funções e implicações clínicas de LOX são analisadas visto que seus níveis aumentam em muitas doenças fibróticas e em alguns tumores promovendo metástases, enquanto que a expressão da enzima está reduzida em doenças que envolvem deterioração no metabolismo do cobre. LOX tem funções paradoxais em câncer, uma vez que atua tanto na supressão quanto na promoção tumoral. Discute-se ser papel na aterogênese e disfunção endotelial, distúrbios oculares, fibrose, doenças iatrogênicas, regeneração óssea e aumento do risco de doença cardiovascular, dentre outras. São encarados os últimos avanços associados com a ação pró-angiogênica do cobre e as funções da proteína precursora de LOX, cujos níveis de expressão estão associadas com vários tipos de câncer.

Mechanism of serotonin-promoted synthesis of osteoblast type I collagen / 中华病理学杂志

<p><b>OBJECTIVE</b>To explore the mechanism of serotonin-promoted osteoblast differentiation.</p><p><b>METHODS</b>Expression levels of collagen I and lysyl oxidase (LOX) in osteoblast were measured by RT-PCR after treated by (50, 100, 200 and 400 ng/L) serotonin. LOX siRNA effect was measured by Western blot, and protein levels of collagen I were determined by ELISA after treated by serotonin. Expression levels of Smad2 and Smad3 in osteoblasts were also measured by RT-PCR after treated by serotonin.Moreover, expression levels of LOX were measured by RT-PCR after Smad3 was knockout.</p><p><b>RESULTS</b>Serotonin promoted collagen I and LOX expression. The expression level of collagen I was significantly decreased by LOX siRNA. Furthermore, serotonin up-regulated the expression of Smad2 and Smad3 in osteoblasts, and the expression level of LOX was inhibited by Smad3 siRNA.</p><p><b>CONCLUSION</b>Serotonin promoted collagen I expression by activating Smads signaling pathway and up-regulating the LOX expression.</p>

Lisil-oxidasa (LOX) y proteinas tipo LOX: rol de amino-oxidasas, propiedades moleculares y cataliticas / Lysyl oxidase (LOX) and LOX-like proteins: role of amino-oxidases, molecular and catalytic properties / Lisil-oxidase (LOX) e proteinas tipo LOX: papel da amino-oxidases, propriedades moleculares e catalíticas

Las amino-oxidasas pertenecen a dos grupos de proteinas: flavoenzimas y quinoenzimas. La lisil-oxidasa (LOX) es una quinoenzima que contiene cobre y lisil-tirosil-quinona como cofactor. Los niveles de LOX aumentan en muchas enfermedades fibroticas y en algunos tumores promoviendo metastasis, mientras que la expresion de la enzima esta disminuida en enfermedades que involucran un deterioro en el metabolismo del cobre. Se discute el rol de LOX como amino-oxidasa en la catalisis de la desaminacion oxidativa de residuos de lisina en los precursores del colageno y de elastina, y la participacion de los restantes miembros de esta familia genica: LOXL1, LOXL2, LOXL3 y LOXL4, asi como sus propiedades moleculares. Se analizan su biosintesis, sus propiedades cataliticas y mecanismo de reaccion, cofactores e inhibidores y la expresion y respuesta a diversos efectores celulares.

Amino-oxidases belong to two groups of proteins: flavoenzymes and quinoenzymes. Lysyl oxidase (LOX) is a copper-containing quinoenzime, having lysyl-tyrosyl-quinone as cofactor. LOX levels are increased in many fibrotic diseases, and in some tumors promoting metastasis, while the enzyme expression is decreased in diseases that involve deterioration in copper metabolism. The role of LOX as amino oxidase in catalyzing the oxidative deamination of lysine residues in precursors of collagen and elastin is discussed, as well as the participation of other members of this gene family: LOXL1, LOXL2, LOXL3, and LOXL4, and their molecular properties. The biosynthesis, catalytic properties and reaction mechanism, cofactors and inhibitors, and the expression and response to various cellular effectors are analyzed.

As amina oxidases pertencem a dois grupos de proteínas: flavoenzimas e quinoenzimas. A lisil-oxidase (LOX) é uma quinoenzima contendo cobre e lisil-tirosil-quinona como cofator. Os níveis da enzima LOX aumentam em muitas doenças fibróticas e em alguns tumores promovendo metástase, enquanto que a expressão da enzima está reduzida em doenças que envolvem a deterioração no metabolismo do cobre. Discute-se o papel de LOX como amina oxidase na catálise a desaminação oxidativa de resíduos de lisina de precursores de colágeno e de elastina, e a participação dos outros membros desta família gênica: LOXL1, LOXL2, LOXL3 e LOXL4, bem como as suas propriedades moleculares. A sua biossíntese, as suas propriedades catalíticas e mecanismo de reação, cofatores e inibidores e a expressão e resposta a diversos efetores celulares são analisados.

Gene expressions of LOXs and MMPs of the ACL fibroblasts cells co-cultured with synovial cells / 生物医学工程学杂志

The progress of research on the the anterior cruciate ligament (ACL) wound healing demonstrates that the synovial tissue in the knee joint plays a very important role in the healing process of injured ACL. Therefore, the molecular response mechanisms of lysyl oxidase (LOX) and matrix metalloproteina (MMP) in normal/injured ACL fibroblast cells could be considered to perform the major analysis function of injured ACL healing mechanism. The mRNA expressions of LOXs and MMPs and the activity expressions of MMP-2 in ACL fibroblasts co-cultured with synovial cells were analyzed by quantitative real-time PCR and zymography. The results showed that co-culture could regulate the mRNA expressions of LOXs and MMPs in the ACL fibroblasts cells. These results suggest that the differential expressions of LOXs and MMP-1, 2, 3 in co-cultured ACL indicate that interaction crosstalk do exist between ACL cells and synovial cells and provide a theoretical basis for subsequent exploration of the mechanisms and treatment of ACL injury and repair.

The Differential Expression of Lysyl Oxidase in Keratoacanthoma and Squamous Cell Carcinoma / 대한피부과학회지

BACKGROUND: Because keratoacanthoma (KA) and squamous cell carcinoma (SCC) are very similar with respect to clinical and histological features but are different with respect to prognosis and treatment, it is necessary to differentiate these two diseases. A number of recent studies have been attempted to differentiate these two diseases using immunohistochemical stains; however, the results obtained using these approaches were inconsistent. OBJECTIVE: The purpose of this study was to examine the expression pattern of polyclonal antibody to lysyl oxidase (LOX) on KA and SCC using an immunohistochemical staining method, and to evaluate the ability of this method in distinguishing these two diseases. METHODS: The expression of LOX in 10 cases of KA and 10 cases of SCC, which were confirmed by histopathologic examination, and 10 cases of normal human skin as a control, were evaluated using an immunohistochemical staining method. We divided the degree of immunohistochemical staining into three classifications --high density, low density, and no density-- based on the level of the expression of LOX in the epidermis and the tumor. Evaluation of the immunohistochemical staining was performed by two dermatologists and one pathologist. RESULTS: The rates of high, low, and no density in KA were 50%, 50%, and 0%, respectively. The rates of high, low, and no density in SCC were 40%, 10%, and 50%, respectively. The rates of high, low, and no density in the control group were 70%, 30%, and 0%, respectively. CONCLUSION: Because the degree of LOX expression in KA and SCC was very diverse, it could not be reliably used as a differential stain for the two diseases. But interestingly, no LOX expression was observed in SCC. This suggests that if expression of LOX is absent, there is a high probability of being diagnosed with a malignant skin tumor rather than a benign skin tumor.

Expression of LOX and MMP-2 in gastric cancer tissue and the effects of LOX and MMP-2 on tumor invasion and metastasis / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To compare the expressions of lysyl oxidase (LOX) and matrix metalloproteinases-2 (MMP-2) in gastric cancer and pericancerous tissues, in gastric cancers with and without lymph node metastasis, and to analyze the effects of LOX and MMP-2 on tumor invasion and metastasis.</p><p><b>METHODS</b>Gastric cancer and pericancerous tissues were collected from 46 patients who underwent surgery. Levels of LOX and MMP-2 mRNA were detected by RT-PCR. Protein abundance of LOX and MMP-2 was examined using Western blot.</p><p><b>RESULTS</b>Expressions of LOX and MMP-2 mRNA, and protein in 46 gastric cancers were significantly higher than that in 46 pericancerous tissues. In gastric cancer with lymph node metastasis, the levels of LOX and MMP-2 mRNA and protein were higher than those in gastric cancers without lymph node metastasis (P < 0.05). In the groups of gastric cancer with lymph node metastasis, expression of LOX was positively correlated with MMP-2 protein expression (P < 0.01).</p><p><b>CONCLUSIONS</b>Expressions of LOX and MMP-2 in gastric cancer tissues are significantly higher than that in pericancerous tissues. The expressions of LOX and MMP-2 in gastric cancer with lymph node metastasis are higher than that in gastric cancer without lymph node metastasis. Expressions of LOX and MMP-2 are positively correlated. The results suggest that LOX and MMP-2 may promote the growth and metastasis of gastric cancer.</p>

Effect of lysyl oxidase on migration and adhesion of human gastric cancer HGC-27 cells in vitro / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the effects of lysyl oxidase (LOX) on the migration and adhesion of the human gastric cancer cell line HGC-27 cells in vitro.</p><p><b>METHODS</b>The human gastric cancer cell line HGC-27 cells were cultured in vitro, and treated with different concentration of β-aminopropionitrile (BAPN). The ability of migration was assessed by wound-healing assay. The ability of adhesion was detected by homogenous and heterogeneous adhesion experiments.</p><p><b>RESULTS</b>Compared that with 0 mmol/L BAPN, the ability of migration of the cells after treatment with 0.2 mmol/L BAPN was descended at 8, 24, 32 and 48 h; the number of cells with homogeneous adhesion was increased from (6.97 ± 0.07) × 10(3)/ml to (7.78 ± 0.11) × 10(3)/ml; and the number of cells with heterogeneous adhesion was decreased from (8.98 ± 0.15) × 10(3)/ml to (8.35 ± 0.10) × 10(3)/ml, both < 0.05. Compared with that of cells treated with 0 mmol/L and 0.2 mmol/L BAPN, the migration ability of cells after treatment with 0.3 mmol/L BAPN was descended at 8, 24, 32 and 48 h; the number of cells with homogeneous adhesion was raised to (8.02 ± 0.11) × 10(3)/ml and the number of cells with heterogeneous adhesion was down to (7.93 ± 0.07) × 10(3)/ml (P < 0.05).</p><p><b>CONCLUSION</b>LOX may promote the metastasis of cancer cells by enhancing invasion, increasing heterogeneous adhesion and decreasing homogeneous adhesion.</p>

Conditional knockout of brca1/2 and p53 in mouse ovarian surface epithelium: Do they play a role in ovarian carcinogenesis?

Alterations of genes are known to be critical for the induction of tumorigenesis, but the mechanism of ovarian carcinogenesis is little understood and remains to be elucidated. In this study, we investigated the roles of brca1, brca2 and p53 genes in the development of ovarian cancer using conditional knockout mice generated by a Cre-loxP recombinant system. Following the application of recombinant adenovirus expressing Cre in vitro, the proliferation of ovarian surface epithelium (OSE) was increased. For instance, a significant increase in cell growth was observed in OSE cells in vitro by conditional knockout isolated from the mice bearing concurrent floxed copies of brca1 and brca2/p53. However, the proliferative effect of the ovarian cells was not observed in concurrent brca1/brca2 or p53 knockout mice in vivo, indicating that we could not observe the direct evidence of the involvement of brca1, brca2, and p53 in ovarian carcinogenesis. Since morphological changes including tumor formation were not observed in mice bearing floxed copies of concurrent brca1/brca2 or p53, the inactivation of brca1/2 or p53 is not sufficient for the induction of tumor formation. Taken together, these results suggest that the deficiency of these genes may not be involved directly in the mechanism of ovarian carcinogenesis.

Effect of nifedipine and amlodipine on dead space wound healing in rats.

Effect of two calcium channel blockers (CCBs) nifedipine and amlodipine, was studied on normal and steroid depressed wound healing in albino rats, using the dead space wound model. The drugs enhanced normal healing as evidenced by increase in tensile strength of 10 days old granulation tissue. There was neither a significant change in the hydroxyproline level (or collagen) nor a change in the glycosaminoglycan content in granulation tissue. However, lysyloxidase level was increased significantly. The increase in tensile strength could thus be attributed to better cross-linking and maturation of collagen rather than collagen synthesis per se. The drugs were also able to overcome steroid depressed wound healing. It is likely that the prohealing effects may be related to the improved antioxidant status too, since superoxide dismutase levels were observed to be higher in the CCB- treated animals.

Changes of Gene Expression in NIH3T3 Cells Exposed to Osmotic and Oxidative Stresses

Cells consistently face stressful conditions, which cause them to modulate a variety of intracellular processes and adapt to these environmental changes via regulation of gene expression. Hyperosmotic and oxidative stresses are significant stressors that induce cellular damage, and finally cell death. In this study, oligonucleotide microarrays were employed to investigate mRNA level changes in cells exposed to hyperosmotic or oxidative conditions. In addition, since heat shock protein 70 (HSP70) is one of the most inducible stress proteins and plays pivotal role to protect cells against stressful condition, we performed microarray analysis in HSP70 overexpressing cells to identify the genes expressed in a HSP70 dependent manner. Under hyperosmotic or oxidative stress conditions, a variety of genes showed altered expression. Down regulation of protein phosphatase1 beta (PP1 beta) and sphingosine 1 phosphate phosphatase 1 (SPPase1) was detected in both stress conditions. Microarray analysis of HSP70 overexpressing cells demonstrated that diverse mRNA species depend on the level of cellular HSP70. Genes encoding lysyl oxidase, thrombospondin 1, and procollagen displayed altered expression in all tested conditions. The results of this study will be useful to construct networks of stress response genes.

A Catalogue of Gene Expression Difference in Biliary Cirrhosis due to Biliary Atresia Using Differential Expressed Sequence Tags(EST) Screening

PURPOSE: Extrahepatic biliary atresia is the most common indication for liver transplantation in children, but the etiology of this disorders remains unknown. It would be very signficant to identify genes that are specifically expressed in pathologic liver tissue of biliary atresia and analyze the pattern of expression in those genes. METHODS: We made dot blot panels consisting of 1,730 different EST (expressed sequence tags) clones which were isolated from human hair dermal papilla cell cDNA library. Liver tissues were taken from a recipient with biliary atresia and a normal donor during living-related liver transplantation. Total RNA was extracted from each sample and reversely transcribed to make cDNA. Then radiolabelled cDNA probe pools were made by random primed DNA labeling method and used for screening differentially expressed genes using EST dot blot panel. RESULTS: Among the total of 1,730 EST clones, 26 cDNA clones were overexpressed in biliary cirrhosis. They revealed homology to genes encoding bcl-w, laminin binding protein, hepatocyte growth factor-regulated tyrosine kinase substrate (HRS), thymosin beta-4, 10; transforming growth factor (TGF)-beta, tissue inhibitor of metalloproteinase (TIMP)-1, signal recognition particle (SRP)4, eukaryotic initiation factor (eIF)-2alpha kinase, lysyl oxidase, aldolase A, gamma-glutamylcystein synthetase, collagen type I alpha1, 2, collagen type III, fibronectin, osteonectin, insulin-like growth factor binding protein (IGFBP)-2, 3, and more. In addition, the expression of 2 clones showed that gastrula zinc finger protein and one novel gene were decreased in biliary atresia. CONCLUSOIN: This study identified differentially expressed genes in biliary cirrhosis from progressive biliary atresia using differential EST screening technique.

Influence of Aloe vera on collagen turnover in healing of dermal wounds in rats.

Treatment of full-thickness wounds with A. vera, on rats resulted in increased biosynthesis of collagen and its degradation. A corresponding increase in the urinary excretion of hydroxyproline was also observed. Elevated levels of lysyl oxidase also indicated increased crosslinking of newly synthesised collagen. The results suggest that A. vera influences the wound healing process by enhancing collagen turnover in the wound tissue.

Inhibition of lysyl oxidase by isoniazid and its effect on wound healing.

Isoniazid, an antitubercular drug, is known to be a potent inhibitor of monoamine oxidases. Effects of this drug, on lysyl oxidase (also a monoamine oxidase) and other wound healing parameters were studied in albino rats, in presence and absence of pyridoxal phosphate, using a dead space wound model. Tensile strength, collagen and glycosaminoglycan contents as well as lysyl oxidase activity were estimated in the granuloma tissue harvested from 10 day old dead space wounds. Isoniazid inhibited lysyl oxidase activity and a decrease in tensile strength as well as collagen content were observed. The effects were reversed on administration of a stoichiometric amount of pyridoxal phosphate. Hexosamine level was increased and hexuronic acid level decreased in the drug treated animals. Therefore, isoniazid may decrease the mechanical strength of collagen by inhibiting lysyl oxidase, by competiting for its obligatory cofactor pyridoxal phosphate, as well as by interfering in electrostatic interactions between collagen and the ground substance.