New inflammatory indicators for cell-based liquid biopsy: association of the circulating CD44+/CD24- non-hematopoietic rare cell phenotype with breast cancer residual disease.

BACKGROUND: Breast cancer residual disease assessment in early-stage patients has been challenging and lacks routine identification of adjuvant therapy benefit and objective measure of therapy success. Liquid biopsy assays targeting tumor-derived entities are investigated for minimal residual disease detection, yet perform low in clinical sensitivity. We propose the detection of CD44-related systemic inflammation for the assessment of residual cancer. METHODS: Circulating CD44+/CD45- rare cells from healthy, noncancer- and cancer-afflicted donors were enriched by CD45 depletion and analyzed by immuno-fluorescence microscopy. CD44+ rare cell subtyping was based on cytological feature analysis and referred to as morphological index. AUC analysis was employed for identification of the most cancer-specific CD44+ subtype. RESULTS: The EpCam-/CD44+/CD24-/CD71-/CD45-/DNA+ phenotype alludes to a distinct cell type and was found frequently at concentrations below 5 cells per 5 mL in healthy donors. Marker elevation by at least 5 × on average was observed in all afflicted cohorts. The positive predicted value for the prediction of malignancy-associated systemic inflammation of a CD44+ rare cell subtype with a higher morphological index was 87%. An outlook for the frequency of sustained inflammation in residual cancer may be given to measure 78%. CONCLUSION: The CD44+ rare cell and subtype denotes improvement in detection of residual cancer disease and may provide an objective and alternative measure of disease burden in early-stage breast cancer.

Novel bioactive peptides demonstrating anti-dengue virus activity isolated from the Asian medicinal plant Acacia Catechu.

The therapeutic activities of food-derived bioactive proteins and peptides are attracting increased attention within the research community. Medicinal plants used in traditional medicines are an excellent source of bioactive proteins and peptides, especially those traditionally prepared by water extraction for use as tea or food supplement. In this study, novel bioactive peptides were isolated from enzymatic digests of 33 Thai medicinal plants. The inhibitory activity of each against dengue virus (DENV) infection was investigated. Of 33 plants, peptides from Acacia catechu extract demonstrated the most pronounced anti-DENV activity. Half maximal inhibitory concentration of 0.18 µg/ml effectively inhibited DENV foci formation. Treatment with 1.25 µg/ml crude peptide extract could reduce virus production less than 100-fold with no observable cell toxicity. Peptide sequences were determined by high-performance liquid chromatography and liquid chromatography-tandem mass spectrometry. Two bioactive peptides isolated from Acacia catechu inhibited DENV foci formation >90% at the concentration of 50 µM; therefore, they are recommended for further investigation as antiviral peptides against DENV infection.

Partially Purified Gloriosa superba Peptides Inhibit Colon Cancer Cell Viability by Inducing Apoptosis Through p53 Upregulation.

BACKGROUND: Colon cancer is a major health problem worldwide. Available treatments such as surgery, chemotherapy, radiation and anticancer drugs are limited due to stage of cancer, side effects and altered biodistribution. The use of peptides extracted from natural products has appeared as a potential therapy. Gloriosa superba is known to contain colchicine and other alkaloids with anticancer activity. However, these peptides contained within the extracts have not been studied. This study, therefore, focuses on an investigation of anti-colon cancer activity from a partially purified protein hydrolysate of G superba rhizome. METHODS: Dried G superba rhizome was extracted using 0.5% sodium dodecyl sulfate and digested with pepsin. The protein hydrolysates with molecular weight lesser than 3kDa were collected and subjected for cell viability assay. Then, the partial purification of the protein hydrolysate was performed using reverse-phase high-performance liquid chromatography. Fractions containing anticancer peptides were investigated, and their effects on apoptosis and protein expression using apoptosis test and Western blot, respectively. RESULTS: Partially purified peptides of G superba rhizome demonstrated anticolon activity in SW620 cells by inducing apoptosis through upregulation of p53 and downregulation of nuclear factor kappa B (NF-κB). CONCLUSIONS: Consequently, G superba peptides showed high potential for further purification and development of anticolon therapeutics.