Circulating tumor DNA (ctDNA) is emerging as a novel biomarker for tumor evaluation, offering advantages such as high sensitivity and specificity, minimal invasiveness, and absence of radiation. Currently, various techniques including gene sequencing and PCR are employed for ctDNA detection. The utilization of ctDNA for monitoring minimal residual disease (MRD) enables comprehensive assessment of tumor status and early identification of tumor recurrence, achieving a remarkable detection sensitivity of 0.01%. Therefore, ctDNA holds promise as a biomarker for early diagnosis, treatment response monitoring, and prognosis prediction in solid tumors. This article reviews the commonly used methods for detecting ctDNA and their advantages in evaluating tumor MRD and guiding clinical diagnosis and treatment.
Humans ; Circulating Tumor DNA/genetics* ; Neoplasm, Residual/genetics* ; Biomarkers, Tumor/genetics* ; Neoplasm Recurrence, Local ; Prognosis

No abstract available.
DNA, Neoplasm/genetics ; High-Throughput Nucleotide Sequencing/*methods ; Humans ; Sequence Analysis, DNA/methods ; Urologic Neoplasms/*genetics

DNA Methylation ; DNA, Neoplasm ; genetics ; Genomics ; trends ; Human Genome Project ; Humans ; Neoplasms ; genetics ; Research

OBJECTIVETo investigate relationship between methylation status of the APC and Bikunin CpG islands and clinicopathological characteristics of breast carcinomas.

METHODSThe methylation status of APC and Bikunin CpG islands in 152 sporadic breast carcinoma samples were analyzed by methylation specific PCR.

RESULTS40.8% of breast carcinomas examined showed methylated signals for the APC. The methylation frequency of APC was significantly correlated to the tumor size (chi(2) = 4.041; P = 0.044), but not to patients' age, pathologic type of tumor, clinical stage, histological grade, lymph node metastasis and the status of estrogen or progestogen receptor. In addition, 24.6% of carcinoma samples examined revealed strong methylated signals for Bikunin. No significant correlation was found between the aberrant methylation of Bikunin and the clinicopathological characteristics of sporadic breast carcinomas.

CONCLUSIONThe aberrant methylations of APC and Bikunin are frequent events during breast carcinogenesis. APC methylation might play a role in the progression of breast cancer.

Breast Neoplasms ; genetics ; pathology ; CpG Islands ; DNA Methylation ; DNA, Neoplasm ; genetics ; Female ; Follow-Up Studies ; Humans

Carcinoma, Hepatocellular ; genetics ; Cloning, Molecular ; DNA, Complementary ; genetics ; Genes, Neoplasm ; genetics ; Humans ; Liver Neoplasms ; genetics

OBJECTIVETo make quantitative analysis of DNA content of breast cancer with neuroendocrine (NE) cells and its significance.

METHODSUsing MIPS-III image analyzer, DNA content and 9 parameter measurements of the tumor nuclei were made in both NE positive (17) and negative (64) breast carcinomas.

RESULTSOut of 81 breast carcinomas, 17 cases were NE positive while 64 cases were NE negative. In the NE (+) cases, the integral optic density, mean optic density, DNA index, DNA stemlines peak, > 5c aneuploidy cells and the rate of aneuploidy cells were all lower than those in the NE negative breast carcinoma cases (P < 0.01). The positive rates of NE cells were 32.5% and 7.9% in grade I - II breast carcinomas and in grade III breast carcinomas respectively with significant difference between the two groups (P < 0.01).

CONCLUSIONOur study shows that NE (+) breast carcinomas have lower DNA parameters than NE (-) breast carcinomas, suggesting that NE (+) breast carcinomas have lower malignancy.

Aneuploidy ; Breast Neoplasms ; genetics ; pathology ; Carcinoma, Neuroendocrine ; genetics ; pathology ; DNA, Neoplasm ; genetics ; metabolism

OBJECTIVETo screen methylations of CpG islands in prostate cancer using restriction landmark genomic scanning (RLGS).

METHODSThe DNA was extracted from homogeneous cells captured by laser capture microdissection in 20 prostate cancer and 18 benign prostatic hyperplasia (BPH) tissues for scanning the CpG islands using RLGS. The methylation status of each CpG island was compared between the cancer and BPH samples to screen the genes involved in prostate cancer development. The screened genes were uploaded to DAVID database for GO analysis, and the genes with the most significant methylation were analyzed by pyrosequencing.

RESULTS AND CONCLUSIONAmong all the tested CpG islands, 10245 (37.2%) in prostate cancer and 8658 (30.3%) in BPH samples were found to be abnormally methylated, and >60% of the methylated CpG islands were in the promoter region. Compared with BPH samples, the prostate cancer samples showed differential methyation in 735 CpG islands, including 458 hepermethyated and 256 hypomethelated ones. Seven genes (DPYS, P16, APC, GSTP1, TMEM122, RARB, and ARHGAP20) in prostate cancer were identified to have distinct methylations. Bioinformatics analysis suggested that these genes were associated with several biomolecular and biological processes, and among them DPYS gene was involved in 13 GO anotated biologic functions, development of 50 diseases and 47 protein interactions. Pyrosequencing of 7 sites of the CPG island in DPYS gene showed a methylation frequency of 32.7%, suggesting the importance of DPYS gene in the carcinogenesis and progression of prostate cancer.

CpG Islands ; DNA Methylation ; DNA, Neoplasm ; genetics ; Genomics ; Humans ; Male ; Polymerase Chain Reaction ; Prostatic Hyperplasia ; genetics ; Prostatic Neoplasms ; diagnosis ; genetics

PURPOSE: Gastric carcinoma tissues release high level of prostaglandin E2 (PGE2) when compared to non-neoplastic mucosa, and cyclooxygenase-2 (COX-2), which is the rate-limiting enzyme in prostaglandin (PG) biosynthesis, is often overexpressed in gastric carcinomas and during gastric carcinogenesis. However, little is known about the expression of 15-hydroxyprostaglandin dehydrogenase (15-PGDH), the key enzyme responsible for the biological inactivation of PG, in gastric carcinomas. MATERIALS AND METHODS: We investigated the expression of 15-PGDH in 28 cases of advanced gastric carcinomas by Western blot analysis and also the relation between its expression and the gene promoter methylation. RESULTS: 15-PGDH expression was significantly decreased in gastric carcinomas compared to corresponding non-neoplastic tissues and inversely correlated with the expression of proliferating cell nuclear antigen in gastric carcinomas. However, there was no correlation between 15-PGDH expression and pathological findings such as nodal metastasis and vascular invasion. Promoter hypermethylation of 15-PGDH gene was not detected in carcinomas, with only a negligible expression of the enzyme. CONCLUSION: Our results suggested that 15-PGDH has tumor suppressor activity in gastric carcinomas.
Aged ; Base Sequence ; DNA Methylation ; DNA Primers/genetics ; DNA, Neoplasm/genetics ; Female ; Humans ; Hydroxyprostaglandin Dehydrogenases/genetics/*metabolism ; Male ; Middle Aged ; Promoter Regions, Genetic ; Stomach Neoplasms/*enzymology/genetics

Carcinoma, Hepatocellular ; genetics ; metabolism ; DNA Methylation ; DNA Restriction Enzymes ; metabolism ; DNA, Neoplasm ; genetics ; Glutathione S-Transferase pi ; genetics ; metabolism ; Humans ; Liver Neoplasms ; genetics ; metabolism ; Polymerase Chain Reaction ; methods

The occurrence and development of acute myeloid leukemia (AML) is not only related to gene mutations, but also influenced by abnormal epigenetic regulation, in which DNA methylation is one of the most important mechanisms. Abnormal DNA methylation may lead to the activation of oncogene and the inactivation of tumor suppressor gene, resulting in the occurrence of leukemia. The mutations of DNA methylation enzymes associated with AML may have certain characteristics. The AML with recurrent cytogenetic abnormalities is also related to abnormal methylation. Some fusion genes can alter DNA methylation status to participate in the pathogenesis of leukemia. In addition, chemotherapy drug resistance in patients with AML is associated with the change of gene methylation status. Considering the reversibility of the epigenetic modification, targeted methylation therapy has become a hotspot of AML research.
DNA Methylation ; drug effects ; genetics ; physiology ; DNA Modification Methylases ; genetics ; physiology ; Drug Resistance, Neoplasm ; genetics ; Epigenesis, Genetic ; genetics ; physiology ; Humans ; Leukemia, Myeloid, Acute ; etiology ; genetics ; pathology ; Mutation ; genetics