Human MCM4 ELISA Matched Antibody Pair

Replication fork stalling generates a variety of responses, most of which cause an increase in single-stranded DNA. ssDNA is a primary signal of replication distress that activates cellular checkpoints. It is also a potential source of genome instability and a substrate for mutation and recombination. Therefore, managing ssDNA levels is crucial to chromosome integrity. Limited ssDNA accumulation occurs in wild-type cells under stress. In contrast, cells lacking the replication checkpoint cannot arrest forks properly and accumulate large amounts of ssDNA. This likely occurs when the replication fork polymerase and helicase units are uncoupled. Some cells with mutations in the replication helicase (mcm-ts) mimic checkpoint-deficient cells, and accumulate extensive areas of ssDNA to trigger the G2-checkpoint. Another category of helicase mutant (mcm4-degron) causes fork stalling in early S-phase due to immediate loss of helicase function. Intriguingly, cells realize that ssDNA is present, but fail to detect that they accumulate ssDNA, and continue to divide. Thus, the cellular response to replication stalling depends on checkpoint activity and the time that replication stress occurs in S-phase. In this review we describe the signs, signals, and symptoms of replication arrest from an ssDNA perspective. We explore the possible mechanisms for these effects. We also advise the need for caution when detecting and interpreting data related to the accumulation of ssDNA.

Background: This study aimed to perform coexpression analysis of the EZH2 gene using The Cancer Genome Atlas (TCGA) and the Oncomine databases to identify coexpressed genes involved in biological networks in breast cancer, glioblastoma, and prostate cancer, with functional analysis of the EZH2 gene in the C4-2 human prostate cancer cell line in vitro. Material/Methods: Data from TCGA and Oncomine databases were analyzed to determine the expression of EZH2 and the top five coexpressed genes in breast cancer, glioblastoma, and prostate cancer and the clinical significance the coexpressed genes. Gene Ontology (GO) analysis was performed to predict the functions and pathways of EZH2 using pathway annotation. The role of EZH2 in the C4-2 human prostate cancer cell line was studied in vitro. Results: Analysis of 16 micro-arrays identified 185 genes that were coexpressed with EZH2. The top five coexpressed genes were MCM4, KIAA0101, MKI67, RRM2, and CDC25a. Increased expression of these genes and EZH2 were associated with reduced survival. Coexpressed genes were involved in biological networks associated with the cell cycle, mitosis, and DNA damage. The effects of EZH2 on prostate cancer cell was validated in vitro as knockdown of EZH2 resulted in a G2/M cell cycle arrest, increased DNA damage, and reduced colony number. Conclusions: Coexpression analysis of EZH2 identified its role in the cell cycle, mitosis, and DNA repair. The molecular mechanisms involved in EZH2 gene expression in the cell response to DNA damage requires further study to determine whether EZH2 is a potential human cancer biomarker.