Development of a Prognostic Model Based on the Identification of EMT-Related lncRNAs in Triple-Negative Breast Cancer.

BACKGROUND: Triple-negative breast cancer (TNBC) remains the most incurable subtype of breast cancer owing to high heterogeneity, aggressive nature, and lack of treatment options. It is generally acknowledged that epithelial-mesenchymal transition (EMT) is the key step in tumor metastasis. METHODS: With the application of TCGA and GEO databases, we identified EMT-related lncRNAs by the Cox univariate regression analysis. Optimum risk scores were calculated and used to divide TNBC patients into high-/low-risk subgroups by the median value using the Lasso regression analysis. The Kaplan-Meier and ROC curve analyses were applied for model validation. Then, we assessed the risk model from multi-omic aspects including immune infiltration, drug sensitivity, mutability spectrum, signaling pathways, and clinical indicators. We also analyzed the expression pattern of lncRNAs involved in the model using qRT-PCR in TNBC cell lines and constructed the ceRNA network. RESULTS: The risk model was composed of EMT-related long noncoding RNAs (lncRNAs), which seemed to be valuable in the prognostic prediction of TNBC patients. The model could act as an independent prognostic factor of TNBC and showed a robust prognostic ability in the stratification analysis. Further investigation demonstrated that the expression of lncRNAs was different between high aggressive and low aggressive TNBC cell lines, as well as TNBC patients. CONCLUSIONS: Together, our study successfully established a risk model with great accuracy and efficacy in the prognostic prediction of TNBC patients.

Case Report: Novel RPGRIP1L Gene Mutations Identified by Whole Exome Sequencing in a Patient With Multiple Primary Tumors.

A 78 years old Chinese woman with five different cancer types and a family history of malignancy was the subject of this study. Pancreatic adenocarcinoma and gingival squamous cell carcinoma tissues were obtained from the patient and sequenced using Whole Exome Sequencing. Whole exome sequencing identified 20 mutation sites in six candidate genes. Sanger Sequencing was used for further validation. The results verified six mutations in three genes, OBSCN, TTN, and RPGRIP1L, in at least one cancer type. Immunohistochemistry was used to verify protein expression. mRNA expression analysis using The Cancer Genome Atlas database revealed that RPGRIP1L was highly expressed in several cancer types, especially in pancreatic adenocarcinoma, and correlated with patient survival and sensitivity to paclitaxel, probably through the TGF-ß signaling pathway. The newly identified somatic mutations in RPGRIP1L might contribute to pathogenesis in the patients. Protein conformation simulation demonstrated that the alterations had caused the binding pocket at position 708 to change from concave to convex, which could restrict contraction and extension, and interfere with the physiological function of the protein. Further studies are required to determine the implication of RPGRIP1L in this family and in multiple primary tumors.

Nanovector Assembled from Natural Egg Yolk Lipids for Tumor-Targeted Delivery of Therapeutics.

Nanomedicine uses nanotechnology-based strategies for precision tumor therapy, including passive and ligand-mediated active tumor targeting by nanocarriers. However, the possible biotoxicity of chemosynthetic nanovectors limits their clinical applications. A novel natural egg yolk lipid nanovector (EYLN) was developed for effective loading and delivery of therapeutic agents. Lipids were extracted from egg yolks and reassembled into nanosized particles. EYLNs' stability, cellular uptake, toxicity, and delivery capacity for therapeutic agents were evaluated in vitro. The systemic toxicity and biodistribution of EYLNs were analyzed in normal mice, and the therapeutic effects of doxorubicin (Dox)-loaded EYLNs were evaluated in mouse breast cancer and hepatoma models. EYLNs had a particle size of ∼40 nm and a surface ζ-potential of -45 mV and were effectively internalized by tumor cells, without showing toxicity and side effects in vitro and in vivo. Importantly, their excellent permeability and retention effect significantly enhanced the distribution of EYLNs at tumor sites, and EYLN-Dox effectively inhibited the tumor growth in both mouse models. Targeted modification with folic acid further promoted vector-mediated drug distribution in tumors. This study demonstrates that lipids with specific proportions in the egg yolk can be used to construct natural drug vectors, providing a new strategy for nano-oncology research.

Overcoming Drug Resistance in Colon Cancer by Aptamer-Mediated Targeted Co-Delivery of Drug and siRNA Using Grapefruit-Derived Nanovectors.

BACKGROUND/AIMS: Multidrug resistance (MDR) is the most common cause of chemotherapy failure. Upregulation of P-glycoprotein (P-gp) is one of the main mechanisms underlying MDR. METHODS: In this study, we developed a targeted drug and small interfering (si)RNA co-delivery system based on specific aptamer-conjugated grapefruit-derived nanovectors (GNVs) that we tested in MDR LoVo colon cancer cells. The internalization of nanovectors in cancer cells was tested by fluorescence microscopy and flow cytometry. The anti-cancer activity in vitro was determined by colony formation and cell apoptosis assays. The biodistribution of nanovectors was analyzed by live imaging and the anti-cancer activity in vivo was observed. RESULTS: GNVs loaded with aptamer increased doxorubicin (Dox) accumulation in MDR LoVo cells, an effect that was abolished by pretreatment with DNase. The LA1 aptamer effectively promoted nanovector internalization into cells at 4°C and increased the targeted delivery of Dox to tumors. Constructs harboring Dox, LA1, and P-gp siRNA more effectively inhibited proliferation and enhanced apoptosis in cultured MDR LoVo cells while exhibiting more potent anti-tumor activity in vivo than free Dox or GNVs loaded with Dox alone or in conjunction with LA1, an effect that was associated with downregulation of P-gp expression. CONCLUSION: This GNV-based system may be an effective strategy for overcoming MDR in clinical settings.

Delivery of a chemotherapeutic drug using novel hollow carbon spheres for esophageal cancer treatment.

Low toxicity and high efficacy are the key factors influencing the real-world clinical applications of nanomaterial-assisted drug delivery. In this study, novel hollow carbon spheres (HCSs) with narrow size distribution were developed. In addition to demonstrating their ease of synthesis for large-scale production, we also demonstrated in vitro that the HCSs possessed high drug-loading capacity, lower cell toxicity, and optimal drug release profile at low pH, similar to the pH in the tumor microenvironment. The HCSs also displayed excellent immunocompatibility and could rapidly distribute themselves in the cytoplasm to escape lysosomal clearance. More importantly, the HCSs could efficiently deliver doxorubicin (a representative chemotherapeutic drug) to tumor sites, which resulted in significant inhibition of tumor growth in an esophageal xenograft cancer model. This also prolonged the circulation time and altered the biodistribution of the drug. In conclusion, this study revealed a novel drug delivery system for targeted tumor therapy.