FKBP12

FKBP12 is a cytosolic protein that binds FK506, thereby mediating the immunosuppressive effects of FK506. The FKBP12/FK506 complex binds and inactivates calneurin, a serine/threonine phosphatase. The inhibition of calneurin inhibits Ca2+ and calmodulin-dependent B and T cell responses, by blocking NFAT-mediated transcription. FKBP12 is also found in association with ryanodine receptors: ryanodine play a role in calcium release from endoplasmic and sarcoplasmic reticulum and has been identified in striated muscle and endothelial cells.

 

Immunohistochemical expression

The available antiserum is polyclonal. Staining may be cytoplasmic or nuclear.

Normal tissues:

 

 

FKBP12

CD31

CD34

 

Vascular tumours:

Papillary endothelial hyperplasia (Masson's lesion)

8/81

8/81

8/81

Capillary haemangioma

9/91

9/91

9/91

Kaposi's sarcoma

8/81

7/81

8/81

Epithelioid haemangioendothelioma

13/151

12/151

11/151

Angiosarcoma

18/191

19/191

11/181

Total for vascular tumours

(All 59 vascular tumours stained with at least one marker1)

56/591

55/591

47/581

Non-vascular tumours, by tissue microarray:

Squamous cell carcinoma of lung

1/161

 

1/311

Adenocarcinoma of lung

1/341

1/341

Squamous cell carcinoma of head and neck

1/281

 

 

Adenocarcinoma NOS of head and neck

1/11

1/11

 

Breast fibroadenoma

 

 

1/51

Intraduct carcinoma of breast

0/541

0/541

0/541

Ductal carcinoma of breast

0/1431

2/931

0/1431

Lobular carcinoma of breast

1/81

 

 

Gastric adenocarcinoma

1/341

1/241

 

Colonic adenocarcinoma

0/871

1/691

1/711

Cloacogenic anal carcinoma

1/21

 

 

Hepatocellular carcinoma

 

1/141

 

Conventional renal cell carcinoma

0/361

2/331

2/311

Nephroblastoma

 

1/31

 

Renal oncocytoma

 

1/11

 

Transitional carcinoma of the bladder

0/251

0/251

0/251

Prostatic carcinoma

23/781

5/781

 

Ovarian carcinoma

0/441

1/371

0/441

Endometrial carcinoma

0/261

0/261

0/261

Uterine clear cell carcinoma

 

 

1/11

Papillary thyroid carcinoma

0/201

0/201

4/191

Embryonal sarcoma

 

 

1/21

Adrenocortical carcinoma

2/41

1/41

 

Melanoma

1/191

 

 

Rosai-Dorfmann disease

 

2/21

 

Small lymphocytic lymphoma

 

2/61

 

Follicular lymphoma

1/21

 

 

Multiple myeloma

 

1/11

 

DLBCL

0/361

 

0/361

Mediastinal large cell lymphoma

 

1/111

 

Large cell lymphoma of spleen

 

2/111

 

Lymphoblastic lymphoma

 

 

2/41

Peripheral T cell lymphoma

 

1/31

 

Colonic T cell lymphoma

 

1/11

 

Cutaneous T cell lymphoma

 

1/11

 

Post transplant lymphoma

 

1/11

 

Mast cell disease

 

1/11

 

Solitary fibrous tumour

2/31

 

3/31

Gastrointestinal stromal tumour

 

 

6/101

Hibernoma

1/11

1/11

 

Liposarcoma

 

 

4/91

Myxoid liposarcoma

 

2/81

 

Leiomyosarcoma

 

 

5/101

MPNST

 

 

3/51

Malignant fibrous histiocytoma

 

 

3/111

Giant cell MFH

 

3/111

 

Alveolar soft part sarcoma

 

 

2/21

Total for non-vascular tumours

39/11011

42/10171

39/11011

       

Diagnostic utility

Potentially, the identification of vascular tumours, as part of a panel with CD31 and CD34.

References

 

1Higgins JP, Montgomery K, Wang L, et al. Expression of FKBP12 in benign and malignant vascular endothelium: an immunohistochemical study on conventional sections and tissue microarrays. Am J Surg Pathol 2003; 27:58-64

This page last revised 6.4.2005.

©SMUHT/PW Bishop