NRP1 contributes to stemness and potentiates radioresistance via WTAP-mediated m6A methylation of Bcl-2 mRNA in breast cancer.

NRP1 is a transmembrane glycoprotein that is highly expressed in a variety of tumors. There is evidence that NRP1 can enhance the stem cell properties of tumor cells, which are thought to be resistant to radiotherapy. This study aims to elucidate the potential mechanism of NRP1 in radiation resistance. We transfected NRP1 siRNA and plasmid in breast cancer cells to detect the expression of cancer stem cell markers by western blot and qRT-PCR. The effect of NRP1 on radiotherapy resistance was assesses by immunofluorescence and flow cytometry. In vivo, we established xenograft tumor model treating with shRNA-NRP1 to assess radiotherapy sensitivity. We found that NRP1 could enhance the stem cell properties and confer radioresistance of breast cancer cells. Mechanistically, we proved that NRP1 reduced IR-induced apoptosis by downregulation of Bcl-2 via methyltransferase WTAP in m6A-depentent way. It is suggested that these molecules may be the therapeutic targets for improving the efficacy of radiotherapy for breast cancer.

Facile synthesis of water-soluble and biocompatible fluorescent nitrogen-doped carbon dots for cell imaging.

A simple, facile and green hydrothermal method was developed in the synthesis of water-soluble nitrogen-doped carbon dots (N-CDs) from streptomycin. The as-prepared N-CDs displayed bright blue fluorescence under the irradiation of UV light, together with a high quantum yield of 7.6% and good biocompatibility as demonstrated by the cell viability assay. Thus, the N-CDs can be used as fluorescent probes for cell imaging, which have potential applications in bioimaging and related fields. This strategy opens a new way for the preparation of fluorescent carbon nanomaterials using small molecules as carbon sources.

[Study of quantitative detection of circulating DNA in the plasma of patients with cervical lesion].

OBJECTIVE: To quantitatively detect circulating DNA levels in the plasma of patients withcervical lesion and to determine the value for diagnosis of cervical lesion and cervical cancer. METHODS: Preoperative blood samples were collected from 53 cases of low-grade lesions, 49 cases of high-grade lesions, 44 cases of cervical invasive cancer and 70 cases of healthy women. Plasma DNA was extracted by magnetic bead method (BILATEST DNA kit). The quantity of plasma DNA was determined by duplex real-time quantitative PCR. RESULTS: Median plasma DNA level of invasive cervical cancer patients was 61.59 mg/L (32.06-162.16 mg/L), which was significantly higher than that of healthy women [16.35 mg/L (11.98-22.71 mg/L), P<0.01]. Among invasive cervical cancer patients, median plasma DNA level of squamous carcinoma patients was slightly higher than that of adenocarcinoma (50.43 versus 47.31 mg/L, P>0.05). Median plasma DNA level of stage I patients was lower than that of stage II-III patients (46.02 versus 71.35 mg/L, P<0.05). CONCLUSION: Quantitatively detecting plasma circulating DNA may be with some application prospect in the diagnosis of cervical diseases.

Facile synthesis of N, S-codoped fluorescent carbon nanodots for fluorescent resonance energy transfer recognition of methotrexate with high sensitivity and selectivity.

In this report, N, S-codoped fluorescent carbon nanodots (NSCDs) were prepared by a facile, simple, low-cost, and green thermal treatment of ammonium persulfate, glucose, and ethylenediamine. The as-prepared NSCDs displayed bright blue emission with a relatively high fluorescent quantum yield of 21.6%, good water solubility, uniform morphology, and excellent chemical stability, compared to pure CDs. The fluorescence of NSCDs can be significantly quenched by methotrexate (MTX) via fluorescence resonance energy transfer (FRET) between NSCDs and MTX, which was used for highly selective and sensitive detection of MTX with a wide linear range up to 50.0 µM and a low detection limit of 0.33 nM (S/N = 3). Moreover, this method was explored for practical detection of MTX in human serum with satisfied results.