Biomedical subjects

David Sidransky

Publications and source records attributed to David Sidransky.

At least 55 records · Page 3Linked to original sources

PubMed2005

Uncommon mutation, but common amplifications, of the PIK3CA gene in thyroid tumors.

CONTEXT: As in many other human cancers, overactivation of the phosphotidylinositol 3-kinase (PI3K)/Akt signaling pathway occurs frequently in thyroid cancer, but the mechanism is not completely clear. OBJECTIVE: Because activating mutations and genomic amplification of the PIK3CA gene, which encodes the p110a catalytic subunit of PI3K, are common in many cancers, we sought to investigate this phenomenon in thyroid tumors. DESIGN: To search for PIK3CA mutations, we isolated genomic DNA from primary thyroid tumors of various types and performed direct sequencing of the exons of PIK3CA gene that carry the most common mutations in other cancers. We used real-time quantitative PCR to investigate genomic amplification of the PIK3CA gene. RESULTS: We found no PIK3CA gene mutations in 37 benign thyroid adenomas, 52 papillary thyroid cancers, 25 follicular thyroid cancers, 13 anaplastic thyroid cancers, 13 medullary thyroid cancers, and seven thyroid tumor cell lines. We found a C3075T single-nucleotide polymorphism in exon 20 of this gene in two cases. With a copy number of 4 or more defined as amplification, we found PIK3CA gene amplification in four of 34 (12%) benign thyroid adenomas, three of 59 (5%) papillary thyroid cancer, five of 21 (24%) follicular thyroid cancer, none of 14 (0%) medullary thyroid cancer, and five of seven (71%) thyroid tumor cell lines. The PIK3CA gene amplification and consequent Akt activation were confirmed by fluorescence in situ hybridization and Western blotting studies using cell lines, respectively. CONCLUSION: These data suggest that mutation of the PIK3CA gene is not common, but its amplification is relatively common and may be a novel mechanism in activating the PI3K/Akt pathway in some thyroid tumors.

Class I Phosphatidylinositol 3-Kinases↗

PubMed2005

Differential DNA hypermethylation of critical genes mediates the stage-specific tobacco smoke-induced neoplastic progression of lung cancer.

Promoter DNA methylation status of six genes in samples derived from 27 bronchial epithelial cells and matching blood samples from 22 former/current smokers and five nonsmokers as well as 49 primary non-small cell lung cancer samples with corresponding blood controls was determined using methylation-specific PCR (MSP). Lung tumor tissues showed a significantly higher frequency of promoter DNA methylation in p16, MGMT, and DAPK (P < 0.05; Fisher's exact test). p16 promoter DNA methylation in tumors was observed at consistently higher levels when compared with all the other samples analyzed (P = 0.001; Fisher's exact test). ECAD and DAPK exhibited statistically insignificant differences in their levels of DNA methylation among the tumors and bronchial epithelial cells from the smokers. Interestingly, similar levels of methylation were observed in bronchial epithelial cells and corresponding blood from smokers for all four genes (ECAD, p16, MGMT, and DAPK) that showed smoking/lung cancer-associated methylation changes. In summary, our data suggest that targeted DNA methylation silencing of ECAD and DAPK occurs in the early stages and that of p16 and MGMT in the later stages of lung cancer progression. We also provide preliminary evidence that peripheral lymphocytes could potentially be used as a surrogate for bronchial epithelial cells to detect altered DNA methylation in smokers.

Apoptosis Regulatory Proteins↗

PubMed2005

Increased mitochondrial DNA content in saliva associated with head and neck cancer.

Alterations of the mitochondrial DNA (mtDNA) have been described in human tumors and in other tissues in association with smoking exposure. We did quantitative PCR of cytochrome c oxidase I (Cox I) and cytochrome c oxidase II (Cox II) genes on oral rinse samples obtained from 94 patients with primary head and neck squamous cell carcinoma (HNSC) and a control group of 656 subjects. Mitochondrial DNA/nuclear DNA in saliva from HNSC patients and controls in relationship to smoking exposure, ethanol intake, and tumor stage were examined. Mean levels of Cox I and Cox II in saliva samples were significantly higher in HNSC patients: Cox I, 0.076 [95% confidence interval (95% CI), 0.06-0.09] and Cox II, 0.055 (95% CI, 0.04-0.07) in comparison with controls Cox I, 0.054 (95% CI, 0.05-0.06), P < 0.0001 and Cox II, 0.046 (95% CI, 0.04-0.05), P = 0.003 (t test). MtDNA levels were elevated in primary tumors when compared with matched, pretreatment saliva and significant correlation was noted (Cox I, r = 0.30, P = 0.005 and Cox II r = 0.33, P = 0.002, respectively, Pearson's correlation). On univariate analysis, smoking, age, HNSC diagnosis, and advanced stage of HNSC were associated with higher level of mtDNA content in saliva. Multivariate analysis showed a significant and independent association of HNSC diagnosis, age, and smoking with increasing mtDNA/nuclear DNA for Cox I and Cox II. mtDNA content alteration is associated with HNSC independently of age and smoking exposure, can be detected in saliva, and may be due to elevation in mtDNA content in primary HNSC.

Adolescent↗

PubMed2005

Sensitization to UV-induced apoptosis by the histone deacetylase inhibitor trichostatin A (TSA).

UV-induced apoptosis is a protective mechanism that is primarily caused by DNA damage. Cyclobutane pyrimidine dimers (CPD) and 6-4 photoproducts are the main DNA adducts triggered by UV radiation. Because the formation of DNA lesions in the chromatin is modulated by the structure of the nucleosomes, we postulated that modification of chromatin compaction could affect the formation of the lesions and consequently apoptosis. To verify this possibility we treated human colon carcinoma RKO cells with the histone deacetylase inhibitor trichostatin A (TSA) prior to exposure to UV radiation. Our data show that pre-treatment with TSA increased UV killing efficiency by more than threefold. This effect correlated with increased formation of CPDs and consequently apoptosis. On the other hand, TSA treatment after UV exposure rather than before had no more effect than UV radiation alone. This suggests that a primed (opened) chromatin status is required to sensitize the cells. Moreover, TSA sensitization to UV-induced apoptosis is p53 dependent. p53 and acetylation of the core histones may thus contribute to UV-induced apoptosis by modulating the formation of DNA lesions on chromatin.

Acetylation↗

PubMed2005

Molecular margin analysis predicts local recurrence after sublobar resection of lung cancer.

Sublobar resection for early-stage lung cancer has been used for patients who are not candidates for lobar resection. However, sublobar resection is associated with high local recurrence rates in the context of tumor-free parenchymal margins. The mechanism underlying this high recurrence rate is not well understood. We hypothesized that this elevated risk of local recurrence is due to undetected tumor cells present at parenchymal margins thought to be negative by conventional light microscopy. Thirteen of 44 patients who underwent sublobar resection for lung cancer were found to have a k-ras mutation at codon 12.1. A novel fluorescence-based assay for detection of rare copies of mutant DNA in a background of wild-type DNA, fluorescent gap ligase chain reaction, was used to quantitate the mutant/wild-type DNA in a range of 1 to 1/10,000 in histologically normal margins from these resections. Nine of 13 patients had at least one margin with the number of mutant cells over or equal to a threshold of 1/5,000, and of these, 6/9 (67%) recurred locally. None of the remaining 4 patients without mutant DNA in any surgical margin had evidence of recurrence. The higher rate of local recurrence associated with sublobar resection of lung cancer is likely due to the occult presence of tumor cells at resection margins. These occult tumor cells can be quantitated using a novel fluorescence-based assay and define a group of patients at high risk for local recurrence who are candidates for adjuvant therapy or more extensive resection. This methodology may be adaptable to a real-time format for intraoperative use.

Carcinoma, Non-Small-Cell Lung↗

PubMed2005

Loss of heterozygosity patterns provide fingerprints for genetic heterogeneity in multistep cancer progression of tobacco smoke-induced non-small cell lung cancer.

Dilution end point loss of heterozygosity (LOH) analysis, a novel approach for the analysis of LOH, was used to evaluate allelic losses with the use of 21 highly polymorphic microsatellite markers at nine chromosomal sites most frequently affected in smoking-related non-small cell lung cancers. Allelotyping was done for bronchial epithelial cells and matching blood samples from 23 former and current smokers and six nonsmokers as well as in 33 adenocarcinomas and 25 squamous cell carcinomas (SCC) and corresponding matching blood from smokers. Major conclusions from these studies are as follows: (a) LOH at chromosomal sites 8p, 9p, 11q, and 13q (P >0.05, Fisher's exact test) are targeted at the early stages, whereas LOH at 1p, 5q, 17p, and 18q (P <0.05, Fisher's exact test) occur at the later stages of non-small cell lung cancer progression; (b) LOH at 1p, 3p, 5q, 8p, 9p, 11q, 13q, 17p, and 18q occurs in over 45% of the tobacco smokers with SCC and adenocarcinoma; (c) compared with bronchial epithelial cells from smokers, there is a significantly higher degree of LOH at 1p, 5q, and 18q in adenocarcinoma and at 1p, 3p, and 17p in SCC (P <0.05, Fisher's exact test). We propose that lung cancer progression induced by tobacco smoke occurs in a series of target gene inactivations/activations in defined modules of a global network. The gatekeeper module consists of multiple alternate target genes, which is inclusive of but not limited to genes localized to chromosomal loci 8p, 9p, 11q, and 13q.

Adenocarcinoma↗

PubMed2005

Absence of V599E BRAF mutations in desmoplastic melanomas.

BACKGROUND: Desmoplastic melanoma is an uncommon variant of cutaneous melanoma that mimics soft tissue sarcoma both clinically and morphologically. An activating point mutation of the BRAF oncogene has been identified in a high proportion of conventional cutaneous melanomas, but its frequency in the desmoplastic subtype is not known. METHODS: The authors tested 12 desmoplastic melanoma specimens for the thymine (T)-->adenine (A) missense mutation at nucleotide 1796 of the BRAF gene using a newly developed assay that employs a novel primer extension method. They also tested 57 vertical growth phase cutaneous nondesmoplastic melanoma specimens. RESULTS: The 1796 T-->A mutation was detected in 23 of the 57 conventional cutaneous melanoma specimens but in none of the 12 desmoplastic melanoma specimens (40% vs. 0%; P=0.0006, Fisher exact 2-tailed test). CONCLUSIONS: The relative importance of BRAF mutational activation in melanocytic tumorigenesis clearly was not the same across the various subtypes of melanoma, even for melanomas of cutaneous origin that are associated with sun exposure. In contrast to conventional cutaneous melanomas, the desmoplastic variant frequently did not harbor an activating mutation of BRAF. Accordingly, patients with melanomas should not be collectively regarded as a uniform group as new therapeutic strategies are developed that target specific genetic alterations.

Female↗

PubMed2005

DeltaNp63alpha up-regulates the Hsp70 gene in human cancer.

HSP70, a stress response protein, is known to be a determinant of cell death and cell transformation. We show that different isoforms of p63 have different transcriptional activities on hsp70 genes. DeltaNp63alpha, an abundantly expressed isoform of p63, activates (in vitro and in vivo), whereas TAp63gamma down-regulates the expression of hsp70. We further show that the transactivation domain at the NH(2) terminus of p63 represses, whereas the COOH terminus activates hsp70 transcription. In addition, DeltaNp63alpha regulates transcription of the hsp70 gene through its interaction with the CCAAT binding factor and NF-Y transcription factors which are known to form a complex with the CCAAT box located in the hsp70 promoter. Moreover, DeltaNp63alpha expression correlates with HSP70 expression in all head and neck cancer cell lines. Finally, we show colocalization of DeltaNp63alpha and HSP70 in the epithelium and coexpression of both proteins in 41 primary head and neck cancers. Our study provides strong evidence for the physiologic association between DeltaNp63alpha and hsp70 in human cancer, thus further supporting the oncogenic potential of DeltaNp63alpha.

Animals↗

PubMed2005

Mitochondrial DNA as a cancer biomarker.

As part of a national effort to identify biomarkers for the early detection of cancer, we developed a rapid and high-throughput sequencing protocol for the detection of sequence variants in mitochondrial DNA. Here, we describe the development and implementation of this protocol for clinical samples. Heteroplasmic and homoplasmic sequence variants occur in the mitochondrial genome in patient tumors. We identified these changes by sequencing mitochondrial DNA obtained from tumors and blood from the same individual. We confirmed previously identified primary lung tumor changes and extended these findings in a small patient cohort. Eight sequence variants were identified in stage I to stage IV tumor samples. Two of the sequence variants identified (22%) were found in the D-loop region, which accounts for 6.8% of the mitochondrial genome. The other sequence variants were distributed throughout the coding region. In the forensic community, the sequence variations used for identification are localized to the D-loop region because this region appears to have a higher rate of mutation. However, in lung tumors the majority of sequence variation occurred in the coding region. Hence, incomplete mitochondrial genome sequencing, designed to scan discrete portions of the genome, misses potentially important sequence variants associated with cancer or other diseases.

Adult↗

PubMed2005

Mutational activation of BRAF is not a major event in sporadic childhood papillary thyroid carcinoma.

Papillary thyroid carcinoma may encompass a mixed group of neoplasms where divergence in clinical behavior may reflect distinct genetic alterations. For example, young patients with papillary thyroid carcinoma have a better prognosis than affected adults, and their carcinomas are much more likely to harbor chromosomal rearrangements involving the RET proto-oncogene. Mutational activation of the BRAF oncogene has recently been identified as the most common genetic alteration in papillary thyroid carcinoma, but little is known about its frequency as a function of patient age. We tested 20 papillary thyroid carcinomas from young patients ranging from 10 to 17 years of age for the thymine (T) --> adenine (A) missense mutation at nucleotide 1796 in the BRAF gene using a newly developed assay that employs a novel primer extension method (Mutector assay). The prevalence of BRAF mutation was compared with a larger group of papillary thyroid carcinomas from previously tested adult patients (>20 years). BRAF mutations were not common in papillary thyroid carcinomas from young patients compared to their counterparts in adults (20 vs 77%; OR=13.3, 95% confidence interval (CI)=3.4-56.5; P<0.0001), but they become increasingly prevalent with advancing patient age (OR as a function of age at 10-year intervals=1.80 CI=1.33-2.44; P<0.001). Unlike papillary thyroid carcinomas that arise in adults, mutational activation of BRAF is not a major genetic alteration in papillary thyroid carcinomas that arise in young patients. The increasing frequency of BRAF mutations as a function of age could help account for the well documented but poorly understood observation that age is a relevant prognostic indicator for patients with papillary thyroid carcinoma.

Adolescent↗

PubMed2005

Ribonucleases as a novel pro-apoptotic anticancer strategy: review of the preclinical and clinical data for ranpirnase.

Cytotoxic ribonucleases (RNases), such as ranpiranase, represent a novel mechanism-based approach to anticancer therapy. These relatively small proteins selectively attack malignant cells, triggering apoptotic response and inhibiting protein synthesis. Ranpirnase, originally isolated from oocytes of Rana pipiens, is a member of a family of endoribonucleases. The anticancer effects of ranpiranase have been documented in both in vitro and in vivo experimental tumor models. The effects of ranpiranase appear to be selective for cancer cells. Based on Phase I study data, the maximum tolerated dose (MTD) was 960 microg/m2, with the dose-limiting toxicity (DLT) characterized by proteinuria with or without azotemia, peripheral edema, and fatigue. Ranpirnase did not induce myelosuppression, mucositis, alopecia, cardiotoxicity, coagulopathy, hepatotoxicity, or adverse metabolic effects. Phase II tumor-specific trials investigated the activity of ranpirnase in malignant mesothelioma, breast cancer, non-small cell lung cancer, and renal cell cancer. A Phase III randomized study in malignant mesothelioma patients compares the combination of ranpirnase plus doxorubicin to doxorubicin monotherapy.

Animals↗

PubMed2005

Frequent 14-3-3 sigma promoter methylation in benign and malignant prostate lesions.

14-3-3Sigma is a putative tumor suppressor gene involved in cell cycle regulation and apoptosis following DNA damage. 14-3-3Sigma loss of expression has been reported is several human cancers, including prostate adenocarcinoma and precursor lesions, and promoter hypermethylation has been proposed as the mechanism underlying gene silencing. Here, we investigate the frequency and extent of 14-3-3sigma promoter methylation in benign and cancerous prostate tissues. We examined tumor tissue from 121 patients with prostate carcinoma (PCa), 39 paired high-grade prostatic intraepithelial neoplasias (HGPIN), 29 patients with benign prostate hyperplasia (BPH), as well as four prostate cancer cell lines using quantitative methylation-specific PCR (QMSP). The percentage of methylated alleles (PMA) was calculated and correlated with clinical and pathological parameters. RT-PCR was performed in the cell lines to assess 14-3-3sigma mRNA expression. PCa, HGPIN, BPH, and cancer cell lines showed ubiquitous 14-3-3sigma promoter methylation. However, the PMA of HGPIN was significantly lower than that of PCa or BPH (P < 0.0001), while PCa and BPH did not significantly differ. The PMA did not correlate with any clinicopathological parameter. All prostate cancer cell lines expressed 14-3-3sigmamRNA. 14-3-3Sigma promoter methylation is a frequent event in prostate tissues and cancer cell lines. Furthermore, there is a progressive accumulation of neoplastic cells with 14-3-3sigma methylated alleles from HGPIN to PCa, suggesting a role for this epigenetic event in prostate carcinogenesis. However, other mechanisms besides promoter methylation might be required for effective 14-3-3sigma downregulation.

14-3-3 Proteins↗

PubMed2005

p63-specific activation of the BPAG-1e promoter.

p63, a member of the p53 superfamily, is an essential cell fate determinant for stratified epithelium. Deficiency of p63 leads to lack of differentiated epithelium from the skin and the presence of trace undifferentiated cells left in the dermis. We found that transcriptionally active isoforms of p63, TAp63beta and TAp63gamma, activated the skin-specific promoter of bullous pemphigoid antigen 1 (BPAG-1). The p63-response element was localized between bases -177 and -153 upstream of exon 1 in the BPAG-1e promoter, whereas regions surrounding the response element suppressed transcriptional responses to p53 and TAp73beta, resulting in p63-specific activation of the promoter. This represents a novel molecular mechanism by which target gene induction by p63 is distinguished from induction by other p53 family members.

Animals↗

PubMed2005

Differential recognition of response elements determines target gene specificity for p53 and p63.

p63 is a member of the p53 tumor suppressor gene family, which regulates downstream target gene expression by binding to sequence-specific response elements similar to those of p53. By using oligonucleotide expression microarray analysis and analyzing the promoters of p63-induced genes, we have identified novel p63-specific response elements (p63-REs) in the promoter regions of EVPL and SMARCD3. These p63-REs exhibit characteristic differences from the canonical p53-RE (RRRCWWGYYY) in both the core-binding element (CWWG) as well as the RRR and/or YYY stretches. Luciferase assays on mutagenized promoter constructs followed by electromobility shift analysis showed that p53 preferentially activates and binds to the RRRCATGYYY sequence, whereas p63 preferentially activates RRRCGTGYYY. Whereas EVPL protein is highly expressed in epithelial cells of the skin and pharynx in the p63+/+ mouse, it is undetectable in these tissues in the p63-/- mouse. Our results indicate that p63 can regulate expression of specific target genes such as those involved in skin, limb, and craniofacial development by preferentially activating distinct p63-specific response elements.

Amino Acid Sequence↗

PubMed2005

MT1G hypermethylation is associated with higher tumor stage in prostate cancer.

PURPOSE: Zinc is involved in several physiologic processes, including cell growth and proliferation. Although in normal prostate tissue zinc levels are high, there is a marked decrease in prostate cancer. Metallothioneins control the bioavailability of zinc and one isoform, MT1G, was reported down-regulated in prostate cancer. Here, we investigated whether promoter methylation might cause MT1G silencing in prostate cancer. PATIENTS AND METHODS: The MT1G promoter was assessed by quantitative methylation-specific PCR on prospectively collected tissue samples from 121 patients with prostate cancer, 39 paired high-grade prostatic intraepithelial neoplasias (HGPIN), 29 patients with benign prostatic hyperplasia, 13 normal prostate tissue samples from cystoprostatectomy specimens, and prostate cancer cell lines. The methylation levels were calculated and were correlated with clinical and pathologic variables. Reverse transcription-PCR was done in cell lines to assess MT1G mRNA expression before and after demethylating treatment. RESULTS: MT1G promoter hypermethylation was found in 29 of 121 prostate cancer, 5 of 39 HGPIN, 3 of 29 benign prostatic hyperplasia, and 0 of 13 normal prostate tissue samples. No significant differences in methylation frequencies or levels were found (P = 0.057, for both). Methylation levels were found to correlate with tumor stage but not with Gleason grade. MT1G hypermethylation was more frequent in prostate cancer that spread beyond the prostate capsule. All prostate cancer cell lines tested showed MT1G promoter methylation, but no differences in expression were apparent after demethylation. CONCLUSIONS: Our findings suggest that MT1G promoter methylation is associated with tumor aggressiveness in prostate cancer and it might be a marker of locally advanced disease.

Adenocarcinoma↗

PubMed2005

T1799A BRAF mutations in conjunctival melanocytic lesions.

PURPOSE: To gain a better understanding of the molecular events leading to the development of conjunctival melanocytic lesions and conjunctival melanoma, this study was conducted to investigate the presence of T1799A BRAF oncogenic mutation in these lesions. METHODS: Forty-eight surgically excised conjunctival melanocytic lesions from 48 patients were examined for the presence of the BRAF T1799A mutation. Twenty-eight lesions were conjunctival nevi, of which 20 were excised from children younger than 18 years. Fifteen lesions were conjunctival primary acquired melanosis (PAM; 11 without atypia and 4 with atypia) and five were conjunctival melanomas. To detect the BRAF T1799A mutation, both a newly developed kit (Mutector; TrimGen, Sparks, MD) and direct DNA sequence analysis of exon 15 after PCR amplification were used. RESULTS: The T1799A BRAF mutation was identified in 14 of 28 (50%) conjunctival nevi analyzed, but in none of the 15 conjunctival PAMs, with and without atypia. The T1799A BRAF mutation was identified in two of the five (40%) conjunctival melanomas. There was no difference in the BRAF mutation detected in conjunctival nevi in children or adults, as the BRAF mutation was detected in 50%. CONCLUSIONS: The results showed that conjunctival nevi, similar to skin nevi, have a high frequency of oncogenic BRAF mutations. Furthermore, the results suggest that the oncogenic event leading to BRAF mutations affect only conjunctival nevi and not conjunctival PAM. The clinical significance of these observations remains to be determined.

Adolescent↗

PubMed2005

Colorimetric approach to high-throughput mutation analysis.

High-throughput genomic mutation screening for primary tumors has characteristically been expensive, labor-intensive, and inadequate to detect low levels of mutation in a background of wild-type signal. We present a new, combined PCR and colorimetric approach that is inexpensive, simple, and can detect the presence of 1% mutation in a background of wild-type. We compared manual dideoxy sequencing of p53 for eight lung cancer samples to a novel assay combining a primer extension step and an enzymatic colorimetric step in a 96-well plate with covalently attached oligonucleotide sequences. For every sample, we were able to detect the presence or absence of the specific mutation with a statistically significant difference between the sample optical density (OD) and the background OD, with a sensitivity and specificity of 100%. This assay is straightforward, accurate, inexpensive, and allows for rapid, high-throughput analysis of samples, making it ideal for genomic mutation or polymorphism screening studies in both clinical and research settings.

Biological Assay↗

PubMed2004

A quantitative promoter methylation profile of prostate cancer.

PURPOSE: Promoter hypermethylation is an alternative pathway for gene silencing in neoplastic cells and a promising cancer detection marker. Although quantitative methylation-specific PCR (QMSP) of the GSTP1 promoter has demonstrated near perfect specificity for cancer detection in prostate biopsies, we postulated that identification and characterization of additional methylation markers might further improve its high (80-90%) sensitivity. EXPERIMENTAL DESIGN: We surveyed nine gene promoters (GSTP1, MGMT, p14/ARF, p16/CDKN2A, RASSF1A, APC, TIMP3, S100A2, and CRBP1) by QMSP in tissue DNA from 118 prostate carcinomas, 38 paired high-grade prostatic intraepithelial neoplasias (HGPIN), and 30 benign prostatic hyperplasias (BPH). The methylation levels were calculated and were correlated with clinical and pathologic indicators. RESULTS: Only the methylation frequencies of GSTP1 and APC were significantly higher in prostate carcinoma compared with BPH (P < 0.001). Methylation levels of GSTP1, APC, RASSF1A, and CRBP1, differed significantly between prostate carcinoma and HGPIN, and/or HGPIN or BPH (P < 0.0001). With QMSP and empirically defined cutoff values, the combined use of GSTP1 and APC demonstrated a theoretical sensitivity of 98.3% for prostate carcinoma, with 100% specificity. Methylation levels were found to correlate with tumor grade (GSTP1 and APC) and stage (GSTP1, RASSF1A, and APC). CONCLUSIONS: Our data demonstrate the existence of a progressive increase of promoter methylation levels of several cancer-related genes in prostate carcinogenesis, providing additional markers to augment molecular detection of prostate carcinoma. Because methylation levels of GSTP1, APC, and RASSF1A are associated with advanced grade and stage, QMSP might augment the pathologic indicators currently used to predict tumor aggressiveness.

Adenocarcinoma↗