Tumor-specific immunohistochemical markers are valuable in the differential diagnosis of malignant small round cell tumors (MSRCTs). The cone-rod homeobox-containing gene (CRX) is a transcription factor that is preferentially expressed in retinal photoreceptor cells. It has been shown that the CRX antibody is a good immunohistochemical marker to differentiate retinoblastoma from other intracranial MSRCTs. Outside of the central nervous system, however, the usefulness of CRX immunohistochemistry in establishing a diagnosis of metastatic retinoblastoma is uncertain, as the expression of CRX in primitive neuroectodermal tumor/Ewing sarcoma (PNET/ES), neuroblastoma, and other MSRCTs is unknown. Archival specimens from resections, core biopsies, and bone marrow biopsies of 41 neuroblastomas, 24 PNET/ES, 19 embryonal rhabdomyosarcomas, 17 alveolar rhabdomyosarcomas, 17 Wilms tumors, 14 desmoplastic small round cell tumors, 20 medulloblastomas, 9 pineal tumors, 17 melanocytic tumors (compound and Spitz nevi), and 8 retinoblastomas were immunostained for CRX. All retinoblastomas had strong diffuse nuclear immunoreactivity for CRX; 8 of the 20 medulloblastomas showed strong nuclear immunoreactivity either in occasional clusters of tumor cells or in rare single scattered tumor cells; 3 of the 9 pineal tumors showed strong nuclear immunoreactivity in approximately 40% to 50% of the tumor cells. Neuroblastomas, PNET/ES, embryonal rhabdomyosarcomas, alveolar rhabdomyosarcomas, Wilms tumors, desmoplastic small round cell tumors, and melanocytic tumors were all negative. Scant nonspecific cytoplasmic staining was observed in some tumors, mostly PNET/ES. These findings suggest that CRX is a useful marker to discriminate metastatic retinoblastoma from other, more common, MSRCTs of childhood.
[Show abstract][Hide abstract] ABSTRACT: To describe the authors' clinical experience with intracameral tissue plasminogen activator (tPA) after glaucoma surgery.
Retrospective review of medical records of all patients who received intracameral tPA after glaucoma surgery at the Doheny Eye Institute from November 4, 1992, to June 14, 1994. There were 20 tPA administrations (18 eyes of 17 patients) in doses ranging from 6 to 25 microgram. Indication for tPA administration was decreased bleb function secondary to blood/fibrin clot in aqueous outflow pathway.
Tissue plasminogen activator was given after trabeculectomy (5 drug administrations) and combined cataract extraction/trabeculectomy procedures (9 drug administrations), with increased filtration in 12 (86%). There were five (36%) instances of hyphema and three (21%) of hypotony. All hyphemas occurred after doses of 25 microgram. Final IOP of 18 mmHg or lower and 6 mmHg or higher was achieved in 11 (92%) of 12 patients after a mean follow-up interval of 4.2+/-4.7 months. The six remaining tPA irrigations were done in five patients after glaucoma drainage implant surgery (n=4) or surgical/needle revision of a filtering bleb (n=2).
Aqueous outflow obstruction from blood/fibrin clot after glaucoma surgery may be treated effectively with intracameral tPA in doses of 6 to 25 microgram. The authors recommend using a dose of less than or equal to 6 to 12.5 microgram to minimize risk of hyphema.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Retinoblastoma is the childhood retinal cancer that defined tumour-suppressor genes. Previous work shows that mutation of both alleles of the RB1 retinoblastoma suppressor gene initiates disease. We aimed to characterise non-familial retinoblastoma tumours with no detectable RB1 mutations. METHODS: Of 1068 unilateral non-familial retinoblastoma tumours, we compared those with no evidence of RB1 mutations (RB1(+/+)) with tumours carrying a mutation in both alleles (RB1(-/-)). We analysed genomic copy number, RB1 gene expression and protein function, retinal gene expression, histological features, and clinical data. FINDINGS: No RB1 mutations (RB1(+/+)) were reported in 29 (2·7%) of 1068 unilateral retinoblastoma tumours. 15 of the 29 RB1(+/+) tumours had high-level MYCN oncogene amplification (28-121 copies; RB1(+/+)MYCN(A)), whereas none of 93 RB1(-/-) primary tumours tested showed MYCN amplification (p<0·0001). RB1(+/+)MYCN(A) tumours expressed functional RB1 protein, had fewer overall genomic copy-number changes in genes characteristic of retinoblastoma than did RB1(-/-) tumours, and showed distinct aggressive histological features. MYCN amplification was the sole copy-number change in one RB1(+/+)MYCN(A) retinoblastoma. One additional MYCN(A) tumour was discovered after the initial frequencies were determined, and this is included in further analyses. Median age at diagnosis of the 17 children with RB1(+/+)MYCN(A) tumours was 4·5 months (IQR 3·5-10), compared with 24 months (15-37) for 79 children with non-familial unilateral RB1(-/-) retinoblastoma. INTERPRETATION: Amplification of the MYCN oncogene might initiate retinoblastoma in the presence of non-mutated RB1 genes. These unilateral RB1(+/+)MYCN(A) retinoblastomas are characterised by distinct histological features, only a few of the genomic copy-number changes that are characteristic of retinoblastoma, and very early age of diagnosis. FUNDING: National Cancer Institute-National Institutes of Health, Canadian Institutes of Health Research, German Research Foundation, Canadian Retinoblastoma Society, Hyland Foundation, Toronto Netralaya and Doctors Lions Clubs, Ontario Ministry of Health and Long Term Care, UK-Essen, and Foundations Avanti-STR and KiKa.
The Lancet Oncology 03/2013; 14(4). DOI:10.1016/S1470-2045(13)70045-7 · 24.69 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Abstract. microRNAs are small non-coding RNAs of ~22 nucleotides that function at post-transcriptional level as
negative regulators of gene expression. Aberrant expression of microRNAs could promote uncontrolled proliferation, migration and invasion of human cancer cells. In this study, we analyzed the expression of microRNA-18b (miR-18b) in breast cancer cell lines and in a set of clinical specimens. Our results showed that miR-18b was upregulated in four out five breast cancer cell lines and also in breast tumors. In order to identify potential gene targets, we carried out transcriptional profiling of MDA-MB-231 breast cancer cells that ectopically expressed miR-18b. Our results showed that 263 genes were significantly modulated in miR-18b-deficient
cells (fold change >1.5; P≤0.05). We found that knock-down of miR-18b induced the upregulation of 55 olfactory receptor (OR) genes and nine genes (NLRP7, KLK3, OLFM3, POSTN, MAGED4B, KIR3DL3, CRX, SEMG1 and CEACAM5) with key roles in cell migration and metastasis. Consistently, we found that ectopic inhibition of miR-18b suppressed the migration of two breast cancer cell models in vitro. In conclusion, we have uncovered genes directly or indirectly modulated by miR-18b which may represent potential therapeutic targets in breast cancer. Our data also pointed out a role of miR-18b in migration of breast cancer cells.
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