Biomarkers, Tumor ; genetics ; Gastrointestinal Stromal Tumors ; diagnosis ; genetics ; Humans ; Succinate Dehydrogenase ; deficiency ; genetics

OBJECTIVE: To explore the genetic basis for a child with succinate semialdehyde dehydrogenase deficiency. METHODS: Peripheral blood samples of the proband and his parents were collected and subjected to Sanger sequencing. High-throughput sequencing was used to verify the gene variants. Bioinformatic software was used to analyze the pathogenicity of the variant sites. RESULTS: Sanger sequencing showed that the proband carried a homozygous c.1529C>T (p.S510F) variant of the ALDH5A1 gene, for which his mother was a carrier. The same variant was not detected in his father. However, high-throughput sequencing revealed that the child and his father both had a deletion of ALDH5A1 gene fragment (chr6: 24 403 265-24 566 986). CONCLUSION The c.1529C>T variant of the ALDH5A1 gene and deletion of ALDH5A1 gene fragment probably underlay the disease in the child. High-throughput sequencing can detect site variation as well as deletion of gene fragment, which has enabled genetic diagnosis and counseling for the family.
Amino Acid Metabolism, Inborn Errors/genetics* ; Child ; Developmental Disabilities ; Humans ; Infant ; Mutation ; Succinate-Semialdehyde Dehydrogenase/genetics*

5-aminolevulinic acid (ALA), a precursor for biosynthesis of pyrrole compounds in living organisms, has been widely used in agriculture and medical photodynamics therapy and is regarded as a promising value-added bio-based chemical. In the previous investigations on ALA production with recombinant Escherichia coli expressing heterogenous C4 pathway gene, LB media supplemented with glucose and ALA precursors succinate and glycine is widely used, leading to high production cost. Succinate participates in ALA biosynthesis in a form of succinyl-CoA. In this study, genes involved in succinyl-CoA consumption, sdhAB (encoding succinic dehydrogenase) or sucCD (encoding succinyl-CoA synthetase) of E. coli MG1655 was knocked out and tested for ALA accumulation. In comparison with the recombinant E. coli strain expressing heterogenous ALA synthetase, the sdhAB- or sucCD-deficient strain accumulate 25.59% and 12.40%, respectively, more ALA in a 5 L fermentor using a defined synthetic medium with glucose as main carbon source and without supplementation of succinate, providing a novel cost-effective approach for industrial production of ALA.
Aminolevulinic Acid ; metabolism ; Escherichia coli ; enzymology ; genetics ; metabolism ; Industrial Microbiology ; methods ; Metabolic Engineering ; methods ; Recombinant Proteins ; genetics ; metabolism ; Succinate Dehydrogenase ; genetics ; metabolism ; Succinate-CoA Ligases ; genetics ; metabolism

Objective: To investigate the clinicopathological features, immunophenotype, ultrastructure, genetic alterations and prognosis of succinate dehydrogenase-deficient renal cell carcinoma (SDH RCC). Methods: A total of 11 SDH RCCs, diagnosed from 2010 to 2019, were selected from the Department of Pathology of Nanjing Jingling Hospital, Nanjing University School of Medicine for clinicopathologic, immunohistochemical (IHC), ultrastructural investigation and follow-up. The molecular features of seven cases were analyzed by the panel-targeted DNA next generation sequencing (NGS). Results: There were seven males and four females, with ages ranging from 24 to 62 years (mean 41.4 years, median 41 years). Microscopically, SDH RCC was mainly composed of solid and tubular structures with local cystic change. Four cases showed nested or trabecular structure distributed in a loose hypocellular connective tissue or around scar, similar to oncocytoma. The neoplastic cells demonstrated flocculent eosinophilic cytoplasm with typical intracytoplasmic vacuoles. Immunohistochemically, eight cases were negative for SDHB; three cases showed focal and weak expression, whereas normal renal tubular and vascular endothelial cells demonstrated strong cytoplasmic staining. NGS of DNA targeted-panel detected pathogenic mutations of SDHB gene in seven cases (including three cases with equivocal IHC expression of SDHB), without any mutations in other SDH related genes. There were four cases of SDHB missense mutation, one case of frameshift mutation, one case of splicing mutation, and one case of acquired stop codon mutation. Conclusions: SDH RCC is a distinct variant of RCCs with genetic tendency or with hereditary cancer syndrome. NGS is recommended to detect the related gene mutations for a definitive diagnosis. The patients should be closely followed up.
Adult ; Carcinoma, Renal Cell/genetics* ; Endothelial Cells ; Female ; Humans ; Kidney Neoplasms/genetics* ; Male ; Middle Aged ; Prognosis ; Succinate Dehydrogenase/genetics* ; Young Adult

OBJECTIVETo investigate clinicopathologic features of succinate dehydrogenase-deficient gastrointestinal stromal tumors (SDH-deficient GIST).

METHODSImmunohistochemical EnVision technique was used to assess the expression of succinate dehydrogenase subunit B (SDHB) in 192 cases of GIST. Cases of SDH-deficient GIST were further evaluated for the presence of CKIT exons 9, 11, 13 and 17 mutations and PDGFRA exons 12 and 18 mutations with clinical followed-up data.

RESULTSSeven of the 192 cases showed SDHB-deficiency (3.6%, 7/192). The patients ranged in age from 35 to 84 years (median=56 years; mean=60 years). Four were male and three were female. Six tumors involved stomach and one involved mesentery. Histopathologic features of SDHB-deficient GIST included four cases of mixed-cell type and three of epithelioid cell type. The tumors commonly involved muscularis propria of the stomach as multiple nodules, creating a plexiform pattern. The tumors had high cellularity with cytoplasmic vacuolization. Five cases developed lymph node metastases including one also metastasizing to liver and pancreas. Two cases showed no evidence of metastasis. None of the 7 cases of the SDHB-deficient GIST had CKIT exons 9, 11, 13 and 17 mutations and PDGFRA exons 12 and 18 mutations. Three of the seven SDHB-deficient GIST cases had followed-up data: two did not recur and one died after 24 months of surgery of unknown cause.

CONCLUSIONSDHB-deficient GIST has characteristic clinicopathologic features with wide-type CKIT gene and a favorable prognosis.

Adult ; Aged ; Aged, 80 and over ; Exons ; Female ; Gastrointestinal Stromal Tumors ; diagnosis ; genetics ; Humans ; Immunohistochemistry ; Male ; Middle Aged ; Mutation ; Prognosis ; Succinate Dehydrogenase ; genetics

BACKGROUNDOur previous studies have shown that both apoptosis and necrosis are involved in hair cell (HC) pathogenesis in aging cochleae. To better understand the biological mechanisms responsible for the regulation of HC death, we examined the activity of succinate dehydrogenase (SDH), a mitochondrial bioenergetic enzyme, in the HCs of aging cochleae.

METHODSThe auditory brainstem response thresholds elicited by tone bursts at 4, 10 and 20 kHz were measured in both young (2-3 months) and aging (22-23 months) Wistar rats. SDH activity was evaluated with a colorimetric assay using nitroblue tetrazolium monosodium salt. The SDH-labeled organs of Corti were double stained with propidium iodide, a DNA intercalating fluorescent probe for illustration of HC nuclei. All the specimens were examined with fluorescence microscopy and confocal microscopy.

RESULTSAging rats exhibited a significant elevation of ABR thresholds with threshold shifts being 34 dB at 20 kHz, 28 dB at 10 kHz, and 25 dB at 4 kHz. Consistent with the reduction in the cochlear function, aging cochleae exhibited the reduction of SDH staining intensity in the apical and the basal ends of the cochleae, where a large number of apoptotic, necrotic, and missing HCs were evident. The reduction in SDH staining appeared in a cell-death-mode dependent fashion. Specifically, SDH labeling remained in apoptotic HCs. In contrast, SDH staining was markedly reduced or absent in necrotic HCs.

CONCLUSIONSIn the aging cochlea, SDH activity is preserved in HCs undergoing apoptosis, but is substantially reduced in necrosis. These results suggest that mitochondrial energetic function is involved in the regulation of cell death pathways in the pathogenesis of aging cochleae.

Aging ; metabolism ; Animals ; Apoptosis ; physiology ; Cochlea ; cytology ; enzymology ; Female ; Hair Cells, Auditory ; enzymology ; Male ; Necrosis ; physiopathology ; Rats ; Rats, Wistar ; Succinate Dehydrogenase ; genetics ; metabolism

OBJECTIVE: To analyze the germline variations of genes RET, VHL, SDHD and SDHB in patients with pheochromocytoma and/or paraganglioma and to evaluate variations of these genes in Chinese patients. METHODS: Patients who were treated in Peking University First Hospital from September 2012 to March 2014 and diagnosed with pheochromocytoma and/or paraganglioma by pathologists were included in this study. Twelve patients were included in total, of whom 11 had pheochromocytoma, and 1 had paraganglioma. Deoxyribonucleic acid (DNA) was extracted from the leukocytes of peripheral blood of the patients. The exons 10, 11, 13-16 of the RET gene, and all exons of VHL, SDHB and SDHD genes and their nearby introns (±20 bp) were amplified with polymerase chain reactions, and the products were sent to a biotechnology company for sequencing. The sequencing results were compared with wildtype sequences of these genes to identify variations. One of the patients was diagnosed with multiple endocrine neoplasia type 2A. A family analysis was performed in his kindred, and his family members received genetic tests for the related variations. RESULTS: Three patients were found to have germline gene variations. A c.136C>T (p.R46X) variation of the SDHB gene was found in a patient with malignant pheochromocytoma. A c.1901G>A (C634Y) variation, as well as c.2071G>A (p.G691S) and c.2712C>G (p.S904S) variations of the RET gene were found in a patient with multiple endocrine neoplasia type 2A. After a family analysis, five family members of this patient were found to have the same variations. c.2071G>A (p.G691S) and c.2712C>G (p.S904S) variations of the RET gene were also found in a clinical sporadic patient without evidence of malignancy. A patient with congenital single ventricle malformation and pheochromocytoma was included in this study, and no variation with clinical significance was found in the four genes of this patient. CONCLUSION 25% (3/12) patients with pheochromocytoma or paraganglioma were found to have missense or nonsense germline gene variations in this study, including the c.136C>T (p.R46X) variation of the SDHB gene, the c.1901G>A (C634Y) variation of the RET gene, and c.2071G>A (p.G691S) and c.2712C>G (p.S904S) variations of the RET gene. The former two variations have already been confirmed to be pathogenic. The existence of these variations in Chinese patients with pheochromocytoma and/or paraganglioma was validated in this study, which supports the conclusion that genetic testing is necessary to be generally performed in patients with pheochromocytoma and/or paraganglioma.
Adrenal Gland Neoplasms/genetics* ; Genetic Testing ; Germ-Line Mutation ; Humans ; Paraganglioma/genetics* ; Pheochromocytoma/genetics* ; Proto-Oncogene Proteins c-ret/genetics* ; Succinate Dehydrogenase/genetics* ; Von Hippel-Lindau Tumor Suppressor Protein/genetics*

OBJECTIVE: To clone the full-length gene encoding succinate dehydrogenase iron-sulfur protein of Schistosoma japonicum (SjSDISP) Chinese strain and express it in Escherichia coli. METHODS: According to the published incomplete EST (BU804141) of SjSDISP and the sequence of multiclone sites of lambda gt11 vector, 2 pairs of primers were designed and synthesized. Then the 3' and 5'ends of the EST of the SjSDISP from adult Schistosoma japonicum cDNA library were amplified by anchored PCR. After sequencing, a full-length cDNA sequence of the SjSDISP was obtained, and then it was cloned into prokaryotic expression vector pGEX-4T-1. Identified by agarosed gel electrophoresis, endonucleases digestion and PCR, the resultant recombinant plasmid was used for the expression under the temperature-dependent condition and Western blot analysis. RESULTS: A 1,071 bp sequence was obtained. Sequence analysis showed that the fragment contained a complete open reading frame (ORF), encoding 278 amino acid residues. This target fragment was cloned into the prokaryotic expression vector pGEX-4T-1, and expressed in Escherichia coli. SDS-PAGE revealed that the molecular weight of the expressed fusion recombinant product was 56 kD. Western blot showed that the recombinant protein was recognized by polyclonal rabbit antiserum immunized with Schistosoma japonicum adult worm antigen. CONCLUSION Cloning of the full-length gene encoding SjSDISP and its bacterial expression were successfully done.
Amino Acid Sequence ; Animals ; Base Sequence ; Cloning, Molecular ; Escherichia coli ; metabolism ; Helminth Proteins ; biosynthesis ; genetics ; Iron-Sulfur Proteins ; biosynthesis ; genetics ; Molecular Sequence Data ; Recombinant Proteins ; biosynthesis ; genetics ; Schistosoma japonicum ; genetics ; metabolism ; Sequence Homology ; Succinate Dehydrogenase ; biosynthesis ; genetics

OBJECTIVETo study the clinicopathologic features, diagnosis and differential diagnosis of succinate dehydrogenase (SDH) deficient gastrointestinal stromal tumors (GISTs) as a unique tumor subtype.

METHODSSDHB and SDHA immunohistochemistry was performed in 120 gastric GISTs, in addition to CD117, DOG-1, CD34, smooth muscle actin (SMA), desmin, S-100 protein, cytokeratin (CK) and Ki-67. Subset of the cases was further evaluated for the presence of mutations in CKIT exons 9, 11, 13 and 17 mutations and platelet derived growth factor receptor alpha(PDGFRA) exons 12 and 18.

RESULTSEight of 120 (6.6%) GIST cases were found SDH-deficient including 3 male and 5 female patients (median age of 36.2 years; ranging 16 to 65 years of age). The tumors involved antrum (6 cases), lesser curvature (1 case) and fundus (1 case). Macroscopically, the dominant tumor masses varied from 3 to 10 cm in diameter with a multinodular or plexiform pattern involving the gastric wall. Microscopically,tumor cells had predominantly epithelioid morphology, with occasional mixed spindle cell nodules. Lymphovascular invasion was identified in 5 cases. Immunohistochemistry for SDHB was negative in all 8 cases, and SDHA was negative in 5 cases. All 8 SDHB negative cases also expressed CD117, DOG-1 and CD34, but were negative for SMA, desmin, S-100 and CK. All 8 cases were found to have wild-type CKIT and PDGFRA genes. Available clinical follow-up were obtained in 7 cases, ranging from 2 to 60 months (median follow-up 23.3 months), and all patient were alive. Three cases were found to have liver metastases at their first diagnosis, and one developed omental and mesenteric metastases in 17 months.

CONCLUSIONSSDH-deficient GIST is a distinct subtype of GIST, with a predilection to occur in young and female patients. Characteristic pathological findings include multinodular gastric wall involvement, epithelioid cell morphology, frequently lymphovascular invasion with occasional lymph node and liver metastases, but an overall indolent clinical behavior. Immunohistochemistry for SDHB is required for the diagnosis.

Adolescent ; Adult ; Aged ; DNA Mutational Analysis ; Exons ; Female ; Gastrointestinal Neoplasms ; enzymology ; genetics ; Gastrointestinal Stromal Tumors ; enzymology ; genetics ; Genotype ; Humans ; Immunohistochemistry ; Male ; Middle Aged ; Mutation ; Succinate Dehydrogenase ; deficiency ; genetics ; Young Adult

The functional mutation of c-kit and platelet-derived growth factor receptor α (PDGFRA) which encode proto-oncogene receptor tyrosine kinase are the crucial pathogeneses of gastrointestinal stromal tumors(GISTs). 80%-85% c-kit gene mutation including exon 11,exon 9,exon 13,exon 17 and 5%-10% PDGFRA gene mutation such as exon 18, exon 12 are examined in GISTs. Neither of c-kit or PDGFRA gene mutation are called wide type GISTs. The pathogeneses of wild type GISTs are not clear. The deficiency of succinate dehydrogenase B(SDHB)-related insulin-like growth factor 1(IGF-1R) activation, BRAF gene mutation and neurofibromatosis type 1 may be related to progression of wild type GISTs. More than half of metastatic GISTs patients receiving imatinib treatment can develop to c-kit secondary mutations, which are responsible for secondary resistance. However, the reasons of imatinib resistance in GISTs without c-kit secondary mutation need to be explored. At present, many clinical trials are ongoing to evaluate new drugs in GISTs treatment, including nilotinib, masitinib, pazopanib, dovitinib, ponatinib, dasatinib, crenolanib, linsitinib and immunotherapy, which may bring resistance GISTs treatment to new hope. Next generation sequencing (NGS) and liquid biopsy will be very important in GISTs research and clinical practice.
Benzimidazoles ; therapeutic use ; Exons ; Gastrointestinal Stromal Tumors ; drug therapy ; genetics ; High-Throughput Nucleotide Sequencing ; Humans ; Imatinib Mesylate ; Mutation ; Piperidines ; Protein Kinase Inhibitors ; therapeutic use ; Proto-Oncogene Proteins c-kit ; genetics ; Pyrimidines ; therapeutic use ; Quinolones ; therapeutic use ; Succinate Dehydrogenase ; genetics ; Sulfonamides