[1057] NANOG Immunohistochemical Expression in Tumors

Myra Wilkerson, Fan Lin, Jianhui Shi. Geisinger Medical Center, Danville, PA

Background: The NANOG gene is located on human chromosome 12p13. The NANOG protein product is a homeobox DNA binding transcription factor that prevents differentiation of embryonic stem cells. Down regulation of the NANOG gene expression allows cell differentiation to occur. NANOG protein expression has been described in testicular intratubular germ cell neoplasia (ITGCN), classic seminoma, and embryonal carcinoma, but is not expressed in yolk sac tumors or teratomas. Published data on NANOG expression in other tumors is limited. In this study, we investigated the expression of NANOG protein in a large series of tumors from various organs using a single immunostaining system (Dako).
Design: Immunohistochemical evaluation of NANOG protein expression [Novus Biologicals, Nanog antibody (5A10)(NBP1-04320)] was performed on 998 tumors from various organs using tissue microarray sections. The staining intensity was graded as weak or strong. The distribution was recorded as negative (<5% of tumor cells stained), 1+ (5-25%), 2+ (26-50%), 3+ (51-75%), or 4+ (>75%).
Results: The positive staining results (%) and the total number of cases for each entity (N) are summarized in Table 1. Fifty-four of 998 cases demonstrated positive nuclear staining for NANOG protein and these cases consisted of testicular ITGCN, embryonal carcinoma, and classic seminoma.

Table 1. Summary of NANOG immunostaining in 998 cases

Tumor	N	# Positive	% Positive
Testicular ITGCN	17	17	100
Testicular classic seminoma	23	22	95.7
Testicular embryonal CA	16	15	93.8
Testicular yolk sac tumor	6
Testicular spermatocytic seminoma	1
Testicular Leydig cell tumor	3
Urothelial CA primary to bladder	31
Pulmonary neuroendocrine CA	62
Pulmonary ADC	97
Pulmonary squamous cell CA	45
Pancreatic ductal ADC	46
Pancreatic endocrine CA	14
Clear cell renal cell CA	30
Papillary renal cell CA	16
Infiltrating duct CA of breast	123
Infiltrating lobular CA of breast	48
Esophageal ADC	24
Gastric ADC	13
Colonic ADC	27
Hepatocellular CA	17
Cholangiocarcinoma	5
Melanoma	72
Papillary CA of thyroid	41
Follicular CA of thyroid	31
Prostatic ADC	124
Ovarian serous ADC	15
Endocervical ADC	13
Endometrial ADC	38
Total tumors	998	54	5.4

ADC-adenocarcinoma; CA-carcinoma


Conclusions: Our data demonstrate that NANOG is a highly sensitive and specific marker for undifferentiated testicular germ cell tumors including ITGCN, classic seminoma, and embryonal carcinoma. NANOG does not appear to be expressed in testicular yolk sac tumors, or in tumors from other organs.
Category: Genitourinary (including renal tumors)

Monday, March 19, 2012 1:00 PM

Poster Session II # 134, Monday Afternoon