Background:
The PTEN FISH test is designed to detect chromosome 10q deletions and monosomy 10. The PTEN gene (phosphatase and tensin homolog) is a tumor suppressor gene at 10q23 that regulates cell cycle progression; loss of PTEN function is very frequent in human cancers, and often occurs by deletion (but also by chromosome loss).
Loss of PTEN is associated with poor prognosis across a variety of tumors, including glioblastoma, melanoma and adenocarcinoma, among others. Absence of PTEN leads to dysregulation of the PI3 kinase pathway, for which a number of targeted therapeutics are available.
FISH studies are useful adjuncts to complete chromosome studies, particularly when following an abnormal clone, assessing relapse and progression, or when material is inadequate for chromosomal analysis.
- PTEN/CEP10 probe set, to detect 10q deletion and monosomy 10.
Methodology:
FISH is performed on sections of formalin-fixed, paraffin-embedded tumor tissue. Slides are prepared per standard protocols and 100 interphase cells are scored. For other specimen types (bone marrow, blood), 200 interphase cells are scored.
Specimen Requirements:
- Formalin-fixed paraffin-embedded tumor block or FFPE slides: Store at room temperature.
- If sending slides, please include H&E stained slide cut from same block
- Preferred slice thickness is 4-5 microns on positively charged slides.
- Please submit 3-5 slides. Store at room temperature.
- Contact Client Services at (855) 535-1522 for shipping supplies and instructions.
- Bone Marrow: Shortly before aspiration add 0.2 cc of Sodium Heparin (1,000 units/ml) to tube of transport medium (please contact lab to arrange for transport medium to be sent). Add at least 1 cc of bone marrow aspirate to the tube and suspend well. Allow no clots to form.
- Peripheral blood: May be used if bone marrow is inaspirable and blasts (.5%) are present. Send in Sodium Heparin tube.
- Bone core biopsy: May also provide cells in cases where marrow is severely packed. Send in transport medium with Sodium Heparin.
*Sterile Ringer’s solution, either lactated or non-lactated and sterile isotonic saline are alternatives, if no complete RPMI is available. Contact Client Services for more information on media requirements.
It is preferable to collect the specimen before initiation of chemotherapy in the patient. Tumor samples should be selected from viable areas, with as little normal or necrotic material as possible.
Unacceptable specimens are acellular, necrotic specimens, septic specimens, specimens in fixative or frozen, or specimens collected more than one week previously.
A REQUISITION FORM MUST ACCOMPANY ALL SAMPLES. Please provide detailed clinical information.
Test Performed (Days):
Mon - Sat
Turn Around Time:
3 - 7 days
Shipment Sensitivity Requirements:
Ship via overnight express, using the FedEx priority overnight label provided. Use cold pack to keep specimens cool, but not frozen. Contact Client Services at (855) 535-1522 for shipping kits and instructions.
References:
Additional Info: