Histomorphometric and Immunohistochemical Diagnosis of Renal Cell Carcinoma: Review Article.

Renal cell carcinoma (RCC) is derived from renal tubular epithelial cells and is among the 10 most common cancers worldwide. Incidence of renal cell carcinoma is 400,000 individuals worldwide per year. The age of diagnosis is approximately 60years, and twice as many men are diagnosed as women. African Americans have a slightly higher rate of RCC than do White peoples. The reasons for this are not clear. Inherited syndromes in family, long term dialysis, smoking individuals who had quit smoking >10 years prior had a lower risk when compared to those who had quit <10 years. 22.5 pack-year smokers had a more than 50.0% increased RCC risk compared to nonsmokers, high body mass index i.e. 5kg/m2 increase in body mass index (BMI) was found to be strongly associated with RCC. BMI >35kg/m2 is associated with higher incidence of Cancer raise blood pressure- Higher BMI and hypertension were independently shown to increase the long-term risk of RCC in men. A rise of blood pressure of 10mmHg is associated with 10-22 percent risk of RCC. Clear cell carcinoma is the most common variety of renal cell carcinoma as compared to other varieties of renal cell carcinomas (68.0-75.0%). It has also been found that CAIX is positive for all papillary renal cell carcinoma and negative for CK7, AMACR & TEF. We also found that CK7, EMA, CD117 and CAIX are most commonly positive for all chromophobe renal cell carcinoma. It has been found that clear cell carcinoma is the most common variety of renal cell carcinoma as compared to other varieties of renal cell carcinomas (68.0-75.0%). Again it has also been found that CAIX is positive for all papillary renal cell carcinoma and negative for CK7, AMACR and TEF. Here it has been found that chromophobe carcinoma is most commonly positive for CK7, EMA, CD117 and CAIX. In a patient coming with signs and symptoms of renal cell carcinoma can be confirmed with the help of histoimmunological markers and in that case one can plan for a proper planning of management.

Analysis of clinicopathological and molecular features of ELOC(TCEB1)-mutant renal cell carcinoma.

OBJECTIVE: This study aimed to investigate the clinicopathological and molecular characteristics of ELOC(TCEB1)-mutant renal cell carcinoma. METHODS: Sanger sequencing was used to assess 32 cases originally diagnosed as clear cell renal cell carcinoma with CK7 positive and/or fibromyomatous stroma. Of these, 4 patients with ELOC(TCEB1) gene mutation were screened, and their clinicopathological data were collected for histomorphological observation, immunohistochemical staining, and follow-up, and relevant pieces of literature were reviewed. RESULTS: The 4 patients with ELOC(TCEB1) mutations were all males and aged between 57 and 64 years (median age: 59 years old). The tumor was located in the renal cortex, with a diameter of 2-3.5 cm. The cross-section was grayish-yellow and grayish brown, solid and nodular, and clearly demarcated from the surrounding tissues. Of the 4 patients, 3 harbored a thick fibrous pseudocapsule rich in smooth muscle and were separated from the surrounding normal renal tissue, and 2 of them showed focal invasion into the pseudocapsule, whereas 1 patient had no capsule but had focal invasion into the surrounding renal parenchyma. The tumor tissues mainly exhibited elongated or branched aciniform or tubular structures, commonly accompanied by interspersed small cystic and focal clustered short papillary structures. The cytoplasm of the tumor cells was rich and lightly stained, and the nuclear grading ranged from 1 to 2. All patients showed loose edema in the stroma, and 2 patients showed a small number of interspersed smooth muscle bundles. All 4 patients showed EMA, CA9, AMACR, and TCEB1 expression, and TCEB1 was mainly located in the nucleus. Vimentin, CK7, and CD10 expressions were observed in most cases; CD117, TFE3, HMB45, and melanA were not expressed in all tumors; the expression rate of Ki67 was 3%- 8%. All 4 patients had a point mutation in ELOC(TCEB1) Y79C. The patients were followed up for 24-93 months (mean 49 months), and all of them survived to date without recurrence or metastasis. CONCLUSION: ELOC(TCEB1)-mutant renal cell carcinoma is a rare type of renal cell carcinoma, which tends to occur in middle-aged and elderly men. The main characteristics of this tumor are the branching alveolar or tubular structure with clustered short papillae, presence of fibromyomatous stroma, and the expression of CK7, CA9, CD10, and AMACR. Positive TCEB1 nuclear staining may be an important marker and the Sanger sequencing method is helpful for the diagnosis of this type of RCC. Most patients harbor tumors exhibiting low nuclear grade and inert clinical behavior, and a few tumors exhibit high nuclear grade and aggressive characteristics.

Inborn Errors of Bile Acid Metabolism.

Inborn errors of bile acid metabolism are rare causes of neonatal cholestasis and liver disease in older children and adults. The diagnosis should be considered in the context of hyperbilirubinemia with normal serum bile acids and made by urinary liquid secondary ionization mass spectrometry or DNA testing. Cholic acid is an effective treatment of most single-enzyme defects and patients with Zellweger spectrum disorder with liver disease.

Serine racemase deficiency attenuates choroidal neovascularization and reduces nitric oxide and VEGF levels by retinal pigment epithelial cells.

Choroidal neovascularization (CNV) is a leading cause of blindness in age-related macular degeneration. Production of vascular endothelial growth factor (VEGF) and macrophage recruitment by retinal pigment epithelial cells (RPE) significantly contributes to the process of CNV in an experimental CNV model. Serine racemase (SR) is expressed in retinal neurons and glial cells, and its product, d-serine, is an endogenous co-agonist of N-methyl-d-aspartate receptor. Activation of the receptor results in production of nitric oxide (. NO), a molecule that promotes retinal and choroidal neovascularization. These observations suggest possible roles of SR in CNV. With laser-injured CNV mice, we found that inactivation of SR-coding gene (Srrnull ) significantly reduced CNV volume, neovascular density, and invading macrophages. We exploited the underlying mechanism in vivo and ex vivo. RPE from wild-type (WT) mice expressed SR. To explore the possible downstream target of SR inactivation, we showed that choroid/RPE homogenates extracted from laser-injured Srrnull mice contained less inducible nitric oxide synthase and decreased phospho-VEGFR2 compared to amounts in WT mice. In vitro, inflammation-primed WT RPEs expressed more inducible NOS, produced more. NO and VEGF than did inflammation-primed Srrnull RPEs. When co-cultured with inflammation-primed Srrnull RPE, significantly fewer RF/6A-a cell line of choroidal endothelial cell, migrated to the opposite side of the insert membrane than did cells co-cultured with pre-treated WT RPE. Altogether, SR deficiency reduces RPE response to laser-induced inflammatory stimuli, resulting in decreased production of a cascade of pro-angiogenic cytokines, including. NO and VEGF, and reduced macrophage recruitment, which contribute synergistically to attenuated angiogenesis.

Genetic mutations in accordance with a low malignant potential tumour are not demonstrated in clear cell papillary renal cell carcinoma.

Clear cell papillary renal cell carcinoma (CCPRCC) cases were evaluated for mutations on the following genes: KRAS, NRAS, BRAF, PIK3CA, ALK, ERBB2, DDR2, MAP2K1, RET and EGFR. Four male and three female patients of age 42-74 years were evaluated. All cases were incidentally detected by ultrasound and ranged 1.8-3.5 cm. Microscopic examination showed variably tubulopapillary, tubular acinar, cystic architecture and the characteristic linear arrangement of nuclei. The cells were reactive with CK7 (strong), CA IX (cup-shape) and 34 ß E12. CD10, AMACR/RACEMASE and GATA3 were negative. There were no mutations on any of the investigated genes. This preliminary observation supports the concept that CCPRCC might be indeed an indolent tumour worth it to be named as clear cell papillary neoplasm of low potential.

Alpha-methylacyl-CoA racemase deletion has mutually counteracting effects on T-cell responses, associated with unchanged course of EAE.

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system. Altering the metabolism of immune cells is an attractive strategy to modify their activity during autoimmunity in MS. We investigated the effect of modulating fatty acid metabolism in an animal model of MS, EAE. Alpha-methylacyl-CoA racemase (AMACR) converts R-configuration branched fatty acids into the S-configuration, thereby preparing them for ß-oxidation. We observed a significant, disease-dependent elevation of AMACR expression in monocytes and T cells from blood, draining lymph nodes and spleen of EAE mice during the preclinical phase. In vitro analysis revealed that the proliferation of T cells was inhibited in AMACR KO mice, but T-cell polarization was switched toward a pathogenic state involving the production of more IFN-γ and IL-17, but less IL-4. These opposing effects appeared to cancel out each other in vivo, because AMACR KO EAE mice showed a marginal increase in the severity of early clinical symptoms. AMACR was not regulated in the white blood cells of MS patients. Our data show that AMACR is regulated in immune cells during EAE, but it is not a suitable target for the treatment of MS due to its opposing effects.

Subchronic pharmacological and chronic genetic NMDA receptor hypofunction differentially regulate the Akt signaling pathway and Arc expression in juvenile and adult mice.

NMDA receptor (NMDAR) hypofunction is a compelling hypothesis for the pathophysiology of schizophrenia, because in part, NMDAR antagonists cause symptoms in healthy adult subjects that resemble schizophrenia. Therefore, NMDAR antagonists have been used as a method to induce NMDAR hypofunction in animals as a pharmacological model of schizophrenia. Serine racemase-null mutant (SR-/-) mice display constitutive NMDAR hypofunction due to the lack of d-serine. SR-/- mice have deficits in tropomyosin-related kinase receptor (TrkB)/Akt signaling and activity regulated cytoskeletal protein (Arc) expression, which mirror what is observed in schizophrenia. Thus, we analyzed these signaling pathways in MK801 sub-chronically (0.15mg/kg; 5days) treated adult wild-type mice. We found that in contrast to SR-/- mice, the activated states of downstream signaling molecules, but not TrkB, increased in MK801 treated mice. Furthermore, there is an age-dependent change in the behavioral reaction of people to NMDAR antagonists. We therefore administered the same dosing regimen of MK801 to juvenile mice and compared them to juvenile SR-/- mice. Our findings demonstrate that pharmacological NMDAR antagonism has different effects on TrkB/Akt signaling than genetically-induced NMDAR hypofunction. Given the phenotypic disparity between the MK801 model and schizophrenia, our results suggest that SR-/- mice more accurately reflect NMDAR hypofunction in schizophrenia.

D-serine deficiency attenuates the behavioral and cellular effects induced by the hallucinogenic 5-HT(2A) receptor agonist DOI.

Both the serotonin and glutamate systems have been implicated in the pathophysiology of schizophrenia, as well as in the mechanism of action of antipsychotic drugs. Psychedelic drugs act through the serotonin 2A receptor (5-HT2AR), and elicit a head-twitch response (HTR) in mice, which directly correlates to 5-HT2AR activation and is absent in 5-HT2AR knockout mice. The precise mechanism of this response remains unclear, but both an intrinsic cortico-cortical pathway and a thalamo-cortical pathway involving glutamate release have been proposed. Here, we used a genetic model of NMDAR hypofunction, the serine racemase knockout (SRKO) mouse, to explore the role of glutamatergic transmission in regulating 5-HT2AR-mediated cellular and behavioral responses. SRKO mice treated with the 5-HT2AR agonist (±)-2,5-dimethoxy-4-iodoamphetamine (DOI) showed a clearly diminished HTR and lower induction of c-fos mRNA. These altered functional responses in SRKO mice were not associated with changes in cortical or hippocampal 5-HT levels or in 5-HT2AR and metabotropic glutamate-2 receptor (mGluR2) mRNA and protein expression. Together, these findings suggest that D-serine-dependent NMDAR activity is involved in mediating the cellular and behavioral effects of 5-HT2AR activation.

Decreased susceptibility to seizures induced by pentylenetetrazole in serine racemase knockout mice.

The N-methyl-D-aspartate (NMDA)-type glutamate receptor plays a key role in excitatory synaptic transmission. The overactivation of the NMDA receptor has been implicated in the development of epileptic seizures. D-Serine is a coagonist of the NMDA receptor and its biosynthesis is catalyzed by serine racemase (SR). Here, we examined the effect of d-serine deficiency on the seizures induced by a single injection of pentylenetetrazole (PTZ) using SR knockout (KO) mice. We found that, compared with wild-type (WT) mice, SR-KO mice showed the attenuation of seizure expression in terms of a significantly shortened duration of generalized seizures and resistance to generalized clonic-tonic seizures. Consistently, immunohistochemical analysis of c-Fos demonstrated that the numbers of cells expressing c-Fos induced by high-dose PTZ in the cerebral cortex, hippocampal CA1, hippocampal CA3, and the basolateral nucleus of the amygdala in WT mice were significantly higher than those in SR-KO mice. Moreover, PTZ induced an increase in extracellular glutamate level in the dentate gyrus of WT mice at two different time phases. However, such a PTZ-induced increase in glutamate level was completely inhibited in SR-KO mice. The present findings suggest that SR may be a target for the development of new therapeutic strategies for epileptic seizures.

Paradoxical roles of serine racemase and D-serine in the G93A mSOD1 mouse model of amyotrophic lateral sclerosis.

D-serine is an endogenous neurotransmitter that binds to the NMDA receptor, thereby increasing the affinity for glutamate, and the potential for excitotoxicity. The primary source of D-serine in vivo is enzymatic racemization by serine racemase (SR). Regulation of D-serine in vivo is poorly understood, but is thought to involve a combination of controlled production, synaptic reuptake by transporters, and intracellular degradation by D-amino acid oxidase (DAO). However, SR itself possesses a well-characterized eliminase activity, which effectively degrades D-serine as well. D-serine is increased two-fold in spinal cords of G93A Cu,Zn-superoxide dismutase (SOD1) mice--the standard model of amyotrophic lateral sclerosis (ALS). ALS mice with SR disruption show earlier symptom onset, but survive longer (progression phase is slowed), in an SR-dependent manner. Paradoxically, administration of D-serine to ALS mice dramatically lowers cord levels of D-serine, leading to changes in the onset and survival very similar to SR deletion. D-serine treatment also increases cord levels of the alanine-serine-cysteine transporter 1 (Asc-1). Although the mechanism by which SOD1 mutations increases D-serine is not known, these results strongly suggest that SR and D-serine are fundamentally involved in both the pre-symptomatic and progression phases of disease, and offer a direct link between mutant SOD1 and a glial-derived toxic mediator.

Causes of and diagnostic approach to methylmalonic acidurias.

Several mutant genetic classes that cause isolated methylmalonic acidurias (MMAuria) are known based on biochemical, enzymatic and genetic complementation analysis. The mut(0) and mut(-) defects result from deficiency of MMCoA mutase apoenzyme which requires adenosyl-cobalamin (Ado-Cbl) as coenzyme. The cblA, cblB and the variant 2 form of cblD complementation groups are linked to processes unique to Ado-Cbl synthesis. The cblC, cblD and cblF complementation groups are associated with defective methyl-cobalamin synthesis as well. Mutations in the genes associated with most of these defects have been described. Recently a few patients have been described with mild MMAuria associated with mutations of the MMCoA epimerase gene or with neurological symptoms due to SUCL mutations. A comprehensive diagnostic approach involves investigations at the level of metabolites, genetic complementation analysis and enzymatic studies, and finally mutation analysis. MMA levels in urine range from 10-20 mmol/mol creatinine in mild disturbances of MMA metabolism to over 20000 mmol/mol creatinine in severe MMCoA mutase deficiency, but show considerable overlap and are of limited value for differential diagnosis. The underlying defect in isolated MMAuria can be characterized in cultured skin fibroblasts using several assays, e.g. conversion of propionate to succinate, specific activity of MMCoA, cobalamin adenosyltransferase assay, cellular uptake of CN-[(57)Co] cobalamin and its conversion to cobalamin coenzymes and complementation analysis. The reliable characterization of patients with isolated MMAuria pinpoints the correct gene for mutation analysis. Reliable classification of these patients is essential for ongoing and future prospective studies on treatment and outcome.

Peroxisomal fatty acid alpha- and beta-oxidation in humans: enzymology, peroxisomal metabolite transporters and peroxisomal diseases.

Peroxisomes are subcellular organelles with an indispensable role in cellular metabolism. The importance of peroxisomes for humans is stressed by the existence of a group of genetic diseases in humans in which there is an impairment in one or more peroxisomal functions. Most of these functions have to do with lipid metabolism including the alpha- and beta-oxidation of fatty acids. Here we describe the current state of knowledge about peroxisomal fatty acid alpha- and beta-oxidation with particular emphasis on the following: (1) the substrates beta-oxidized in peroxisomes; (2) the enzymology of the alpha- and beta-oxidation systems; (3) the permeability properties of the peroxisomal membrane and the role of the different transporters therein; (4) the interaction with other subcellular compartments, including the mitochondria, which are the ultimate site of NADH re-oxidation and full degradation of acetyl-CoA to CO(2) and water; and (5) the different disorders of peroxisomal alpha- and beta-oxidation.