Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:1.3.5.1 (succinate dehydrogenase)
8,177 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Phaeochromocytomas (PC) and paragangliomas are disorders of the sympatho-adrenomedullary system. They are chromaffin-containing neuroendocrine tumors of neural crest origin that contain catecholamine-secreting granules: they arise from either the adrenal medulla (phaeochromocytomas) or from extra-adrenal neural crest derivatives e.g. the sympathetic chain (paragangliomas). The term paraganglioma is also used for vascular head and neck tumors derived from parasympathetic tissue, which commonly arise at the carotid bifurcation. It has been reported that some 10% of phaeochromocytomas are part of a familial syndrome, although recent data have suggested that germline mutations in known predisposing syndromes, such as multiple endocrine neoplasia type 2 (MEN2) and Von Hippel-Lindau (VHL), occur in a much higher percentage. However, familial genetic syndromes have been said to be less common in paragangliomas, although more recently described genetic syndromes may not have been considered. Thus, there is increasing evidence that mutations of subunits of the succinate dehydrogenase gene (SDHB, SDHC & SDHD) may confer susceptibility to paragangliomas and head-and-neck paragangliomas (HNPGL). We report a case of a patient with a previously published gene mutation in SDHB who had a single paraganglioma arising from the bladder with a characteristic clinical presentation, and in whom there was a positive family history of a HNPGL. He has demonstrated malignant recurrence with metastases which have been treated, so far successfully, with radiolabelled MIBG.
...
PMID:Familial paraganglioma: a novel presentation of a case and response to therapy with radiolabelled MIBG. 1698 87

Head and neck paragangliomas are tumors derived from parasympathetic paraganglia. Familial cases account for 10% or more of these tumors, and mutations of the genes encoding subunits for the mitochondrial respiratory chain complex II, SDHD, SDHB, and SDHC, have been reported. We analyzed mutations in the all four SDH genes, SDHA through SDHD, in a Japanese family with cervical paraganglioma that include a father with bilateral tumors and his daughter with a malignant left carotid body tumor with nodal metastasis. This pedigree harbored a germline G106D alteration in exon 4 of the SDHD gene that has not previously been reported to date. The tumors of the father expressed biallelic SDHD, but the SDHD expression was highly suppressed by an unknown mechanism(s) in tumors of his daughter, and the wild-type allele was predominantly suppressed in the metastatic node. These results suggest that the missense dysfunction of SDHD prepares neoplastic condition and that expressional silencing, particularly of the wild-type allele, plays an important role in the malignant transformation of the paragangliomas. Our results may lead to a better understanding of this disease and to the development of methods for prevention of this disease.
...
PMID:A novel G106D alteration of the SDHD gene in a pedigree with familial paraganglioma. 1704 23

Genetic understanding of pheochromocytoma (PHEO) and paraganglioma (PGL) syndromes has recently expanded with the identification of the involvement of the mitochondrial complex II peptides, namely the succinate dehydrogenase subunit B (SDHB), subunit C (SDHC), and subunit D (SDHD). In patients with PHEO and/or PGL genetic testing for germline mutations in SDHD and SDHB has been recommended, in addition to the PHEO susceptibility genes VHL and RET. After careful clinical assessment of the patient, suspected familial disease may direct the clinician to the appropriate gene for testing. In the absence of obvious features of familial disease, the decision regarding the appropriate gene for testing is more difficult. Such testing can be costly and time consuming, but a rational prioritization of gene testing can streamline the process. Therefore in order to achieve this for apparently sporadic cases we propose a decision matrix based on site of tumor, functionality, and age at presentation.
...
PMID:Genetic testing in pheochromocytoma- and paraganglioma-associated syndromes. 1710 77

To assess the prevalence of genetic mutations in nonsyndromic pheochromocytoma/paraganglioma (PHEO/PGL) patients we have performed a systematic search for mutations in the succinate dehydrogenase (SDH) B, C, and D subunits, von Hippel-Lindau (VHL), and RET genes by direct bidirectional sequencing. Patients were selected from the medical records of hypertension centers. After exclusion of syndromic patients, 45 patients with familial (F+, n=3) and sporadic (F-, n=42) cases of isolated PHEO/PGL were considered. They included 35 patients with PHEO, 7 with PGL, and 3 with head/neck PGL (hnPGL). Three patients with PHEO (2F-, 1F+) presented VHL mutations (P86A, G93C, and R167W), six with PGL (4F-, 2F+) were positive for SDH or VHL mutations (SDHB R230G in two patients, SDHB S8F, R46Q, R90Q, and VHL P81L in one subject each), and one with hnPGL carried the SDHD 348-351delGACT mutation. We have also detected missense (SDHB S163P, SDHD H50R and G12S), synonymous (SDHB A6A, SDHD S68S), and intronic mutations that have been considered nonpathological polymorphic variants. No mutation was found in SDHC or RET genes. Our data indicate that germline mutations of VHL and SDH subunits are not infrequent in familial as well as in sporadic cases of nonsyndromic PHEO/PGL (overall, 12 of 45 probands, 22%). Accordingly, screening for such mutations seems to be justified. However, a more precise characterization of the functional relevance of any observed sequence variant and of other genetic and environmental determinants of neoplastic transformation is essential in order to plan appropriate protocols for family screening and follow-up.
...
PMID:Genetic mutation screening in an italian cohort of nonsyndromic pheochromocytoma/paraganglioma patients. 1710 82

Pheochromocytomas and paragangliomas are neural-crest-derived tumors that arise from mutations in RET, VHL, NF1, and in the genes-encoding succinate dehydrogenase (SDH) subunits B (SDHB), C (SDHC), and D (SDHD). Despite their genetic diversity, these tumors cannot be clearly distinguished on the basis of their primary mutation. We recently identified two major transcriptional programs embedded within familial and sporadic pheochromocytomas and paragangliomas using global expression profiling. This review will summarize the major results of these studies and discuss their implications. The transcription data revealed that: (a) tumors with mutations in VHL, SDHB, and SDHD genes share a transcription signature of hypoxia, angiogenesis, and oxidoreductase imbalance; (b) SDHB protein is suppressed in tumors with mutations in SDHB and SDHD, and also in a subset of tumors with VHL mutations; and (c) HIF1alpha is involved in the SDHB downregulation observed in these tumors. These results are consistent with the existence of a close interconnection between the VHL and SDH pathways mediated predominantly by hypoxia and oxidoreductase signals. It further suggests that low SDHB levels indicative of impaired mitochondrial complex II function may be a shared element of these pheochromocytomas. SDHB may thus constitute a marker for tumors with abnormal hypoxic profile.
...
PMID:Transcription association of VHL and SDH mutations link hypoxia and oxidoreductase signals in pheochromocytomas. 1710 89

Mutations in the genes encoding succinate dehydrogenase (SDH) have been associated with susceptibility to pheochromocytoma. However, few reports have examined the level of SDH mRNAs expression. In this study, we examined the level of expression of mRNAs encoding SDHB, SDHC, and SDHD in pheochromocytoma, pheochromocytoma subgroups, and normal adrenal gland, and compared the expression of these genes to the level of expression of related genes in the same tissues. The mean relative level of expression of SDHB, SDHC, SDHD and VHL mRNA was 28.7+/-6.2%, 16.6+/-4.8%, 214+/-47.5% and 25.9+/-8.2%, respectively, in pheochromocytoma tissues compared to normal adrenal gland. Furthermore, the mean relative level of the RET proto-oncogene mRNA was 707+/-149% in pheochromocytoma compared to normal adrenal gland. The level of expression of the SDH genes was highly correlated in each individual sample (P<0.0001). The level of expression of the SDH mRNAs correlated with the level of VHL mRNA (P<0.0001), but not with the level of RET mRNA. The level of SDH mRNAs expression also correlated with the expression of phenylethanolamine N-methyl transferase (PNMT), an adrenaline synthesizing enzyme (P<0.01), which may explain the correlation between SDH expression and adrenaline content (P<0.05). The level of SDH mRNAs expression correlated strongly with the expression of VEGF mRNA (P<0.0001). In multiple endocrine neoplasia (MEN) 2a, the expression of the SDH genes and VHL mRNA was significantly higher than that observed in adrenal or extra-adrenal pheochromocytoma. The expression of the corticotropin-releasing hormone (CRH) mRNA was significantly higher in extra-adrenal pheochromocytoma than in adrenal pheochromocytoma or MEN2a. Thus, tumor-specific gene expression exists in pheochromocytoma, which may explain the characteristics of the tumor.
...
PMID:Expression of mRNAs for succinate dehydrogenase subunits and related genes in pheochromocytoma. 1710 93

Familial head and neck paragangliomas account for approximately 10% of all head and neck paragangliomas. There are three known genes associated with genetic susceptibility to head and neck paragangliomas: succinate dehydrogenase complex subunit 'D', 'B' and 'C' (SDHD, SDHB and SDHC). The genes most frequently implicated: SDHD and SDHB, also predispose to phaeochromocytoma. SDHD shows a complex inheritance pattern - tumours do not develop if the mutation is inherited from the mother. SDHB mutations are associated with malignant phaeochromocytoma. Patients who present with a family history of paraganglioma or phaeochromocytoma, with multiple tumours, or early onset tumours (<50 years), should be referred for genetic investigation.
...
PMID:The genetics of paragangliomas: a review. 1765 Dec 79

Evaluation of the possible implication of the SDHA, SDHB, SDHC, SDHD and CS genes in non-obstructive male infertility was performed on the basis that sperm concentration in the ejaculate has been previously correlated with nuclear-encoded mitochondrial enzyme activities (the four subunits of succinate dehydrogenase/complex II of the respiratory chain and citrate synthase). We performed an exhaustive analysis of the five genes for the presence of sequence variants that could be associated with impairment of sperm production. blastn searches in the genomic sequence NCBI database evidenced the presence of highly homologous sequences elsewhere on the genome that can interfere with polymerase chain reaction experiments. Therefore, a careful design of the analytical strategy to search for sequence variants was performed. In this report, we provide primer sequences that allowed selective amplification of coding and immediate flanking regions of the five genes. Fifty-five sequence variations in the five genes were identified in infertile and normozoospermic fertile individuals as controls and only one of them (SDHA c.456+32G>A) showed significant genotype association with impairment of sperm production. Moreover, new single nucleotide polymorphisms identified should be useful in future association studies for other human diseases related to nuclear-encoded genes, leading to mitochondrial respiratory chain activity impairment revealing the physiological role of these genes.
...
PMID:Single nucleotide polymorphisms in succinate dehydrogenase subunits and citrate synthase genes: association results for impaired spermatogenesis. 1729 51

The SDHA, SDHB, SDHC, and SDHD genes code for subunits of succinate dehydrogenase (SDH), which forms part of the mitochondrial respiratory chain. Germline mutations in the genes encoding SDHB and SDHD have been reported in familial paragangliomas/pheochromocytomas and in apparently sporadic pheochromocytomas. SDHB and SDHD mutations are widely distributed along the genes with no apparent hot spots. SDHB mutations are often detected in malignant and extra-adrenal pheochromocytomas. SDHD mutations are also detected frequently in head and neck paragangliomas. We sequenced the entire coding regions of the SDHB and SDHD genes in 17 pheochromocytomas. We identified novel heterozygous G to A point mutations at the first base of intron 3 of the SDHB gene in a malignant extra-adrenal abdominal pheochromocytoma patient, and at the first base of codon 111 of the SDHD gene in an adrenal pheochromocytoma patient. Further, we confirmed the SDHD mutation by DHPLC. The prevalence of SDHB and SDHD mutations in pheochromocytomas we examined was 12% (2/17). Thus, we identified two novel SDH mutations in Japanese pheochromocytomas. Further studies will investigate the oncogenic potential of these mutations.
...
PMID:Novel germline mutations in the SDHB and SDHD genes in Japanese pheochromocytomas. 1730 34

Much attention has been focused on the hypothesis that oxidative damage plays in cellular and organismal aging. It is known that oxygen is initially converted to superoxide anion (O2-), one of reactive oxygen species (ROS), by electron leaked from mainly complex III in the electron transport system present in mitochondria, where it is the major endogenous source of ROS. We have shown that a mutation in a subunit, cytochrome b large subunit (SDHC), of complex II, also results in increasing O2- production and therefore lead to apoptosis and precocious aging in Caenorhabditis elegans. Recently, individuals with an inherited propensity for vascularized head and neck tumors (i.e., paragangliomas) have been demonstrated to contain one of several mutations in complex II. To further explore the role of oxidative stress from mitochondria on apoptosis and cancer, we established a transgenic cell line with a point mutation at the ubiquinone binding region in the SDHC gene. As expected, this mutation increased O2- production from complex II and led to excess apoptosis. Moreover, a significant fraction of the surviving cells from the apoptosis were transformed, as evidenced by increased tumor formation after injection into mice. Oxidative stress results in the damage to the cellular components including mitochondria and, therefore leads to apoptosis. Furthermore, oxidative stress must cause mutations in DNA and leads to cancer. It is suggested that oxidative stress from mitochondria play an important role of both apoptosis, which leads to precocious aging, and cancer.
...
PMID:The role of the electron transport SDHC gene on lifespan and cancer. 1732 Dec 23


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---