Limits...
Characteristic promoter hypermethylation signatures in male germ cell tumors.

Koul S, Houldsworth J, Mansukhani MM, Donadio A, McKiernan JM, Reuter VE, Bosl GJ, Chaganti RS, Murty VV - Mol. Cancer (2002)

Bottom Line: The molecular basis of germ cell (GC) transformation, differentiation, and exquisite treatment response is poorly understood.To assess the role and mechanism of promoter hypermethylation, we analyzed CpG islands of 21 gene promoters by methylation-specific PCR in seminomatous (SGCT) and nonseminomatous (NSGCT) GCTs.The promoter hypermethylation was associated with gene silencing in most methylated genes, and reactivation of gene expression occurred upon treatment with 5-Aza-2' deoxycytidine in GCT cell lines.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Pathology, College of Physicians & Surgeons of Columbia University, 630 West 168th Street, New York, NY, 10032, USA. sk1276@columbia.edu

ABSTRACT

Background: Human male germ cell tumors (GCTs) arise from undifferentiated primordial germ cells (PGCs), a stage in which extensive methylation reprogramming occurs. GCTs exhibit pluripotentiality and are highly sensitive to cisplatin therapy. The molecular basis of germ cell (GC) transformation, differentiation, and exquisite treatment response is poorly understood.

Results: To assess the role and mechanism of promoter hypermethylation, we analyzed CpG islands of 21 gene promoters by methylation-specific PCR in seminomatous (SGCT) and nonseminomatous (NSGCT) GCTs. We found 60% of the NSGCTs demonstrating methylation in one or more gene promoters whereas SGCTs showed a near-absence of methylation, therefore identifying distinct methylation patterns in the two major histologies of GCT. DNA repair genes MGMT, RASSF1A, and BRCA1, and a transcriptional repressor gene HIC1, were frequently methylated in the NSGCTs. The promoter hypermethylation was associated with gene silencing in most methylated genes, and reactivation of gene expression occurred upon treatment with 5-Aza-2' deoxycytidine in GCT cell lines.

Conclusions: Our results, therefore, suggest a potential role for epigenetic modification of critical tumor suppressor genes in pathways relevant to GC transformation, differentiation, and treatment response.

Show MeSH

Related in: MedlinePlus

Methylation-specific PCR of MGMT gene. U, unmethylated; M, methylated; Tumor (T) and cell line (CL) numbers are indicated on the top.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC149411&req=5

Figure 3: Methylation-specific PCR of MGMT gene. U, unmethylated; M, methylated; Tumor (T) and cell line (CL) numbers are indicated on the top.

Mentions: Promoter hypermethylation was not found in normal testes for any of the tested genes except CDH1. CDH1 exhibited methylation in two of the four normal testes analyzed. However, promoter hypermethylation was detected in 43 of the 92 (46.7%) GCTs studied with an individual gene frequency of: RASSF1A, 21.7%; MGMT, 20.7%; BRCA1, 19.8%, HIC1, 19.6%; APC, 9.8%; RARB, 7.6%; CDH1, 7.6%; FHIT, 6.5%, MLH1, 4.3%; TIMP3, 3.3%; GSTP1, 1.1%; and NME2, 1.1% (Fig. 1). The remaining nine genes did not show methylation. Hypermethylation of one or more genes was found only in 5 of 29 (17.2%) SGCTs but in 38 of 63 (60.3%) NSGCTs (Fig. 1). Four of the five SGCTs that exhibited promoter hypermethylation were methylated at a single locus and one tumor at two loci, whereas 27 of the 38 NSGCTs exhibited two or more methylated loci. Promoter hypermethylation was seen in all histologic subsets of NSGCT, with yolk sac tumor (YST) exhibiting a higher frequency of methylation compared to other histologies (Fig. 2 & Fig. 3).


Characteristic promoter hypermethylation signatures in male germ cell tumors.

Koul S, Houldsworth J, Mansukhani MM, Donadio A, McKiernan JM, Reuter VE, Bosl GJ, Chaganti RS, Murty VV - Mol. Cancer (2002)

Methylation-specific PCR of MGMT gene. U, unmethylated; M, methylated; Tumor (T) and cell line (CL) numbers are indicated on the top.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC149411&req=5

Figure 3: Methylation-specific PCR of MGMT gene. U, unmethylated; M, methylated; Tumor (T) and cell line (CL) numbers are indicated on the top.
Mentions: Promoter hypermethylation was not found in normal testes for any of the tested genes except CDH1. CDH1 exhibited methylation in two of the four normal testes analyzed. However, promoter hypermethylation was detected in 43 of the 92 (46.7%) GCTs studied with an individual gene frequency of: RASSF1A, 21.7%; MGMT, 20.7%; BRCA1, 19.8%, HIC1, 19.6%; APC, 9.8%; RARB, 7.6%; CDH1, 7.6%; FHIT, 6.5%, MLH1, 4.3%; TIMP3, 3.3%; GSTP1, 1.1%; and NME2, 1.1% (Fig. 1). The remaining nine genes did not show methylation. Hypermethylation of one or more genes was found only in 5 of 29 (17.2%) SGCTs but in 38 of 63 (60.3%) NSGCTs (Fig. 1). Four of the five SGCTs that exhibited promoter hypermethylation were methylated at a single locus and one tumor at two loci, whereas 27 of the 38 NSGCTs exhibited two or more methylated loci. Promoter hypermethylation was seen in all histologic subsets of NSGCT, with yolk sac tumor (YST) exhibiting a higher frequency of methylation compared to other histologies (Fig. 2 & Fig. 3).

Bottom Line: The molecular basis of germ cell (GC) transformation, differentiation, and exquisite treatment response is poorly understood.To assess the role and mechanism of promoter hypermethylation, we analyzed CpG islands of 21 gene promoters by methylation-specific PCR in seminomatous (SGCT) and nonseminomatous (NSGCT) GCTs.The promoter hypermethylation was associated with gene silencing in most methylated genes, and reactivation of gene expression occurred upon treatment with 5-Aza-2' deoxycytidine in GCT cell lines.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Pathology, College of Physicians & Surgeons of Columbia University, 630 West 168th Street, New York, NY, 10032, USA. sk1276@columbia.edu

ABSTRACT

Background: Human male germ cell tumors (GCTs) arise from undifferentiated primordial germ cells (PGCs), a stage in which extensive methylation reprogramming occurs. GCTs exhibit pluripotentiality and are highly sensitive to cisplatin therapy. The molecular basis of germ cell (GC) transformation, differentiation, and exquisite treatment response is poorly understood.

Results: To assess the role and mechanism of promoter hypermethylation, we analyzed CpG islands of 21 gene promoters by methylation-specific PCR in seminomatous (SGCT) and nonseminomatous (NSGCT) GCTs. We found 60% of the NSGCTs demonstrating methylation in one or more gene promoters whereas SGCTs showed a near-absence of methylation, therefore identifying distinct methylation patterns in the two major histologies of GCT. DNA repair genes MGMT, RASSF1A, and BRCA1, and a transcriptional repressor gene HIC1, were frequently methylated in the NSGCTs. The promoter hypermethylation was associated with gene silencing in most methylated genes, and reactivation of gene expression occurred upon treatment with 5-Aza-2' deoxycytidine in GCT cell lines.

Conclusions: Our results, therefore, suggest a potential role for epigenetic modification of critical tumor suppressor genes in pathways relevant to GC transformation, differentiation, and treatment response.

Show MeSH
Related in: MedlinePlus