Restriction and modification enzymes detect no allosteric changes in DNA with bound lac repressor or RNA polymerase

Elevated expression of RNA methyltransferase BCDIN3D predicts poor prognosis in breast cancer

BACKGROUND

BCDIN3D is a member of the Bin3 methyl-transferase family that targets the 5' mono-phosphate of nucleic acids. Although BCDIN3D has been shown to increase tumorigenic phenotypes and invasiveness in MDA-MB-231 cells, its the clinical implications in breast cancer remain unclear.

METHODS

We screened for BCDIN3D using tissue microarrays constructed from 250 patients who were histologically confirmed to have invasive ductal breast carcinoma at the Fudan University Shanghai Cancer Center.

RESULTS

The survival analysis by Kaplan-Meier and Cox regression showed that BCDIN3D expression level served as a prognostic factor for disease-free survival (P = 0.042). The prognostic value of BCDIN3D was most significant in triple-negative breast cancer (TNBC) patients (P = 0.007).

CONCLUSIONS

BCDIN3D might serve as an important prognostic factor for TNBC patients.

DNA of Drosophila melanogaster contains 5-methylcytosine

It is commonly accepted that the DNA of Drosophila melanogaster does not contain 5-methylcytosine, which is essential in the development of most eukaryotes. We have developed a new, highly specific and sensitive assay to detect the presence of 5-methylcytosine in genomic DNA. The DNA is degraded to nucleosides, 5-methylcytosine purified by HPLC and, for detection by 1D- and 2D-TLC, radiolabeled using deoxynucleoside kinase and [gamma-(32)P]ATP. Using this assay, we show here that 5-methylcytosine occurs in the DNA of D. melanogaster at a level of approximately 1 in 1000-2000 cytosine residues in adult flies. DNA methylation is detectable in all stages of D.melanogaster development.

Junction between Z and B conformations in a DNA restriction fragment: evaluation by Raman spectroscopy

Raman vibrational spectra were obtained from two DNA restriction fragments and the DNA polymer (dG-dC)n . (dG-dC)n in 0.01 and 4.5 M NaCl. One fragment contained 95 base pairs (bp) of the Escherichia coli lactose operator-promoter region (95-bp fragment). The other fragment consisted of the 95-bp region flanked by 26 and 32 bp of dC-dG sequences and BamHI ends (157-bp fragment). In 0.01 M NaCl all three DNAs have Raman spectra characteristic of a right-handed B conformation. The high salt spectrum of the 95-bp fragment is also characteristic of a B conformation. However, the spectrum of the 157-bp fragment in 4.5 M NaCl shows major intensity changes from the 0.01 M NaCl spectrum. These changes are also observed in the high salt spectra of (dG-dC)n . (dG-dC)n and are correlated with the presence of a left-handed Z conformation. Comparisons between the high salt Raman spectra of the 157-bp fragment and spectra calculated from (dG-dC)n . (dG-dC)n and the 95-bp fragment indicated that essentially all of the dC-dG regions in the 157-bp fragment are in the Z conformation and a large part (approximately 80%) of the 95-bp region no longer has a B-type backbone vibration. However, this non-B-DNA-like character of the central region is not indicated by base vibrations.