Biomimetic nanoplatform with selectively positioned indocyanine green for accurate sentinel lymph node imaging.

The status of draining lymph nodes (LNs) is critical for determining the treatment and prognosis of cancer that spreads through the lymphatic system. Indocyanine green (ICG) fluorescence imaging has been widely used in sentinel LN (SLN) biopsy technology and has shown favorable effects. However, this too has its own limitations, such as fluorescence instability and diffusion imaging. In this study, we developed macrophage cell membrane-camouflaged ICG-loaded biomimetic nanoparticles (M@F127-ICG) for accurate SLN imaging. ICG selectively positioned at the hydrophobic-hydrophilic interfaces of pluronic F127 micelles protected itself from quenching in aqueous solution, thereby maintaining fluorescence stability and improving fluorescence intensity. In addition, to further improve the aggregation in SLN, the micellar surface was coated with a layer of biomimetic macrophage cell membrane to target LN-resident macrophages. In vivo fluorescence imaging demonstrated that M@F127-ICG significantly enhanced the fluorescence signal and improved the imaging efficiency of SLN. Thus, selectively positioning ICG in the biomimetic nanoplatform enhanced the fluorescence intensity and stability, providing a novel tracer for timely and accurate SLN imaging.

CERS6-AS1 contributes to the malignant phenotypes of colorectal cancer cells by interacting with miR-15b-5p to regulate SPTBN2.

Accumulating evidence indicates that long noncoding RNAs (lncRNAs) act as tumor promoters or suppressors in various types of cancer. Previous investigations suggest that ceramide synthase 6 (CERS6) antisense RNA 1 (CERS6-AS1) acts as an oncogene in breast cancer; however, its role in colorectal cancer is unknown. This study aimed to explore the molecular mechanism of CERS6-AS1 in colorectal cancer. Gene expression in colorectal cancer was examined using reverse transcription-quantitative polymerase chain reaction and western blot analyses. The viability and proliferation of colorectal cancer cells were measured by Cell Counting Kit-8 assays and colony formation assays. The migratory and invasive capacities of the colorectal cancer cells were assessed by Transwell assay. Cell stemness was examined by sphere-formation assay. Mechanistically, RNA pull-down assays, RNA immunoprecipitation assays, and luciferase reporter assays were performed to explore the relationship among CERS6-AS1, miR-15b-5p and spectrin beta, non-erythrocytic 2 (SPTBN2). Moreover, a xenograft tumor model was established to investigate the role of CERS6-AS1 in vivo. We found that CERS6-AS1 and SPTBN2 were highly expressed in colorectal cancer tissues and cells. CERS6-AS1 depletion inhibited cell viability, proliferation, migration, and invasion; the epithelial-mesenchymal transition process and stemness. It suppressed xenograft tumor growth in colorectal cancer. Moreover, SPTBN2 levels were positively regulated by CERS6-AS1 and negatively regulated by miR-15b-5p in colorectal cancer cells. Rescue assays revealed that SPTBN2 reversed the inhibitory effect of CERS6-AS1 deficiency on the malignant behaviors of colorectal cancer cells. Overall, the lncRNA CERS6-AS1 facilitates malignant phenotypes of colorectal cancer cells by targeting miR-15b-5p to upregulate SPTBN2.

Whole exome sequencing study of a Chinese concurrent cancer family.

Cancer is one of the leading causes of mortality in China, and poses a threat to public health due to its increasing incidence and mortality rates. Concurrent cancer is defined as one or more organs in the same individual having ≥2 primary malignancies occurring simultaneously or successively; however, concurrent cases are rare and poorly studied. The present study recruited a Chinese family presenting multiple cases of concurrent cancer and performed whole exome sequencing in one unaffected and two affected individuals to identify the causative mutations. DNA was extracted from peripheral blood and tumor tissue samples. Following an exome capture and quality test, the qualified library was sequenced as 100 bp paired-end reads on an Ion Torrent platform. Clean data were obtained by filtering out the low-quality reads. Subsequently, bioinformatics analyses were performed using the clean data. After mapping and annotating in 1000 Genomes Project database, the existing SNP database and the Cancer Gene Census (CGC) database, it was revealed that the NADH:ubiquinone oxidoreductase core subunit S7 gene was a candidate gene with somatic mutations, and a subset of 16 genes were candidate genes with germline mutations. The findings of the present study may improve the understanding of the molecular pathogenesis of concurrent cancer.

Combining siRNAs at two different sites in the EGFR to suppress its expression, induce apoptosis, and enhance 5-fluorouracil sensitivity of colon cancer cells.

BACKGROUND: The epidermal growth factor receptor (EGFR) has played an important role in the growth and apoptosis of colon cancer. The RNA interference (RNAi) technique can suppress gene expression, but the effects of double combining sites RNAi targeting EGFR have not been well understood. METHODS: pU6-EGFR-shRNA-1 and pU6-EGFR-shRNA-2 expressive vectors were transfected to the LoVo cells. Five groups were selected for the study: Group 1, the control cells; group 2, the negative control plasmid vector HK; group 3, pU6-EGFR-shRNA-1; group 4, pU6-EGFR-shRNA-2; group 5, pU6-EGFR-shRNA-1 and pU6-EGFR-shRNA-2, half for each. The mRNA and protein expression were assessed by Real Time quantitative PCR and Western blot. Apoptosis was determined via flow cytometry. IC(50) and the inhibition ratio of 5-fluorouracil (5-FU) were carried out by CCK-8. RESULTS: In groups 3, 4, and 5, the mRNA expression was decreased by (80.22 +/- 3.42)%, (81.30 +/- 2.83)%, and (90.58 +/- 2.76)%, respectively, and the protein expression was decreased by (74.11 +/- 4.02)%, (73.39 +/- 2.30)%, and (90.39 +/- 3.34)%, respectively. Meanwhile, the cell apoptosis increased by (10.43 +/- 0.49)%, (10.13 +/- 0.39)%, and (14.17 +/- 0.53)%, respectively. The IC(50) of 5-FU and cell inhibition ratio analysis demonstrated that there were significant differences between the following three: group 5, groups 3 and 4, and groups 1 and 2. CONCLUSIONS: Both pU6-EGFR-shRNA-1 and pU6-EGFR-shRNA-2 are capable of suppressing EGFR expression of the LoVo cell and can promote apoptosis and increase the cell toxicity of 5-FU. The double combining sites RNAi technique is significantly better than a single site.

[Double sites short hairpin RNAs targeting epidermal growth factor receptor to promote colon cancer cells apoptosis and enhance 5-fluorouracil chemotherapy effect].

OBJECTIVE: To investigate the differences about RNA interference (RNAi) technique which focuses on single or multiple sites to suppress colon cancer LoVo cell line's epidermal growth factor receptor (EGFR) mRNA and protein expression, induce cell apoptosis and enhance 5-fluorouracil (5-FU) sensitivity. METHODS: The human colon cancer LoVo cells were transfected by liposome with pU6-EGFR-shRNA-1 and pU6-EGFR-shRNA-2 expressive vectors which were established by p Genesil-1 plasmid and EGFR short hairpin RNA (shRNA) synthesized in vitro, then were selected for 4 weeks by using G418. Five groups were selected for the study: Group 1: the normal cultured LoVo cells; Group 2: the negative control plasmid HK; Group 3: pU6-EGFR-shRNA-1 plasmid vector; Group 4: pU6-EGFR-shRNA-2 plasmid vector; Group 5: pU6-EGFR-shRNA-1 and pU6-EGFR-shRNA-2, half for each. The mRNA and protein expression were assessed using Real Time PCR and Western blot, the cell apoptosis was determined via flow cytometry, and the suppressive rate and IC(50) to LoVo cells by 5-FU of different concentrations and time points were carried out by using Cell Counting Kit-8 (CCK-8). RESULTS: Expression plasmids encoding shRNA were successfully established and transfected into the LoVo cells. In group 3, 4 and 5, the mRNA expression was decreased by (80.2 +/- 3.4)%, (81.3 +/- 2.8)% and (90.6 +/- 2.8)%, respectively, and protein expression was decreased by (74.1 +/- 4.0)%, (73.4 +/- 2.3)% and (90.4 +/- 3.3)%, respectively; meanwhile, cell apoptosis increased by (10.4 +/- 0.5)%, (10.1 +/- 0.4)% and (14.2 +/- 0.5)%, respectively. The IC(50) of 5-FU and cell suppressive rate analysis demonstrated that there were significant differences among group 5, groups 3 and 4, and groups 1 and 2, but there were no significant difference between group 1 and group 2, as well as group 3 and group 4. CONCLUSIONS: Both pU6-EGFR-shRNA-1 and pU6-EGFR-shRNA-2 were capable of suppressing EGFR expression of LoVo cells, and therefore promoting apoptosis and increasing the cell toxicity of 5-FU. The targeting double combined sites RNAi technique was significantly better than single site interference. The new therapeutic modalities in the treatment of human colon cancer are suggested by this study.