Background And Objectives: DNA repair is a new and important pathway that explains colorectal carcinogenesis. This study will evaluate the prognostic value of molecular modulation of double-strand break repair (XRCC2 and XRCC5); DNA damage tolerance/translesion synthesis (POLH, POLK, and POLQ), and interstrand crosslink repair (DCLRE1A) in sporadic colorectal cancer (CRC).
Methods: Tumor specimens and matched healthy mucosal tissues from 47 patients with CRC who underwent surgery were assessed for gene expression of XRCC2, XRCC5, POLH, POLK, POLQ, and DCLRE1A; protein expression of Polk, Ku80, p53, Ki67, and mismatch repair MLH1 and MSH2 components; CpG island promoter methylation of XRCC5, POLH, POLK, POLQ, and DCLRE1A was performed.
Results: Neoplastic tissues exhibited induction of POLK (P < .001) and DCLRE1A (P < .001) expression and low expression of POLH (P < .001) and POLQ (P < .001) in comparison to healthy paired mucosa. Low expression of POLH was associated with mucinous histology and T1-T2 tumors (P = .038); low tumor expression of POLK was associated with distant metastases (P = .042). CRC harboring POLK promoter methylation exhibited better disease-free survival (DFS) (P = .005).
Conclusions: This study demonstrated that low expression or unmethylated POLH and POLK were related to worse biological behavior tumors. However, POLK methylation was associated with better DFS. POLK and POLH are potential prognostic biomarkers in CRC.
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http://dx.doi.org/10.1002/jso.25737 | DOI Listing |
BMC Genomics
April 2023
Cancer Prevention and Control Program, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA, 19111, USA.
Background: Early-onset renal cell carcinoma (eoRCC) is typically associated with pathogenic germline variants (PGVs) in RCC familial syndrome genes. However, most eoRCC patients lack PGVs in familial RCC genes and their genetic risk remains undefined.
Methods: Here, we analyzed biospecimens from 22 eoRCC patients that were seen at our institution for genetic counseling and tested negative for PGVs in RCC familial syndrome genes.
Oncogene
August 2022
Breast Cancer Now Research Unit, King's College London, London, UK.
HORMAD1 expression is usually restricted to germline cells, but it becomes mis-expressed in epithelial cells in ~60% of triple-negative breast cancers (TNBCs), where it is associated with elevated genomic instability (1). HORMAD1 expression in TNBC is bimodal with HORMAD1-positive TNBC representing a biologically distinct disease group. Identification of HORMAD1-driven genetic dependencies may uncover novel therapies for this disease group.
View Article and Find Full Text PDFJ Clin Pathol
February 2022
Postgraduate Program in Pathology, Federal University of Ceara, Fortaleza, Ceara, Brazil
Aims: DNA methylation has its distribution influenced by DNA demethylation processes with the catalytic conversion of 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC). Myelodysplastic syndrome (MDS) has been associated with epigenetic dysregulation of genes related to DNA repair system, chronic immune response and cell cycle.
Methods: We evaluated the tissue DNA methylation/hydroxymethylation in bone marrow trephine biopsies of 73 patients with MDS, trying to correlate with the mRNA expression of 21 genes (, , , and ).
Hematol Transfus Cell Ther
June 2020
Universidade Federal do Ceará (UFC), Fortaleza, Ceará, Brazil; Núcleo de Pesquisas e Desenvolvimento de Medicamentos (NPDM), Fortaleza, CE, Brazil. Electronic address:
Myelodysplastic syndromes (MDS) are a heterogeneous group of hematological malignancies characterized by dysplasias, ineffective hematopoiesis and risk of acute myeloid leukemia transformation. Approximately 90% of MDS patients present mutations in genes involved in various cell signaling pathways. Specialized DNA polymerases, such as POLN, POLI, POLK, POLQ, POLH, POLL and REV3L, insert a nucleotide opposite replication-blocking DNA lesions in an error-prone manner and, in this way, sometimes can actively promote the generation of mutation.
View Article and Find Full Text PDFDNA Repair (Amst)
March 2020
Department of Life Science, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, 171-8588, Japan; Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamada-oka, Suita, Osaka, 565-0871, Japan; National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan. Electronic address:
The (6-4) pyrimidine-pyrimidone photoproduct [(6-4)PP] is a major DNA lesion induced by ultraviolet radiation. (6-4)PP induces complex mutations opposite its downstream bases, in addition to opposite 3' or 5' base, as has been observed through a site-specific translesion DNA synthesis (TLS) assay. The mechanism by which these mutations occur is not well understood.
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