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It has been recognized that cancer stem-like cells (CSCs) in tumor tissue crucially contribute to therapeutic failure, resulting in a high mortality rate in lung cancer patients. Due to their stem-like features of self-renewal and tumor formation, CSCs can lead to drug resistance and tumor recurrence. Herein, the suppressive effect of jorunnamycin A, a bistetrahydroisoquinolinequinone isolated from Thai blue sponge Xestospongia sp., on cancer spheroid initiation and self-renewal in the CSCs of human lung cancer cells is revealed. The depletion of stemness transcription factors, including Nanog, Oct-4, and Sox2 in the lung CSC-enriched population treated with jorunnamycin A (0.5 μM), resulted from the activation of GSK-3β and the consequent downregulation of β-catenin. Interestingly, pretreatment with jorunnamycin A at 0.5 μM for 24 h considerably sensitized lung CSCs to cisplatin-induced apoptosis, as evidenced by upregulated p53 and decreased Bcl-2 in jorunnamycin A-pretreated CSC-enriched spheroids. Moreover, the combination treatment of jorunnamycin A (0.5 μM) and cisplatin (25 μM) also diminished CD133-overexpresssing cells presented in CSC-enriched spheroids. Thus, evidence on the regulatory functions of jorunnamycin A may facilitate the development of this marine-derived compound as a novel chemotherapy agent that targets CSCs in lung cancer treatment.

Cancer stem-like cells (CSCs) are key mediators driving tumor initiation, metastasis, therapeutic failure, and subsequent cancer relapse. Thus, targeting CSCs has recently emerged as a potential strategy to improve chemotherapy. In this study, the anticancer activity and stemness-regulating capacity of 4,5,4′-trihydroxy-3,3′-dimethoxybibenzyl (TDB), a bibenzyl extracted from Dendrobium ellipsophyllum, are revealed in CSCs of various human lung cancer cells. Culture with TDB (5–10 μM) strongly abolished tumor-initiating cells in lung cancer H460, H23, and A549 cells in both anchorage-dependent and anchorage-independent colony formation assays. Through the 3D single-spheroid formation model, attenuation of self-renewal capacity was observed in CSC-enriched populations treated with 1–10 μM TDB for 7 days. Flow cytometry analysis confirmed the attenuation of %cell overexpressing CD133, a CSC biomarker, in TDB-treated lung cancer spheroids. TDB at 5–10 μM remarkably suppressed regulatory signals of p-Akt/Akt, p-GSK3β/GSK3β, and β-catenin corresponding to the downregulated mRNA level of stemness transcription factors including Nanog, Oct4, and Sox2. Moreover, the antiapoptosis Bcl-2 and Mcl-1 proteins, which are downstream molecules of Akt signaling, were evidently decreased in CSC-enriched spheroids after culture with TDB (1–10 μM) for 24 h. Interestingly, the diminution of Akt expression by specific siAkt effectively reversed suppressive activity of TDB targeting on the CSC phenotype in human lung cancer cells. These findings provide promising evidence of the inhibitory effect of TDB against lung CSCs via suppression of Akt/GSK3β/β-catenin cascade and related proteins, which would facilitate the development of this bibenzyl natural compound as a novel CSC-targeted therapeutic approach for lung cancer treatment.

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Alpha folate receptor (FRa) is currently under investigation as a target for the treatment of patients with non-small-cell lung cancer (NSCLC), since it is highly expressed in tumor cells but is largely absent in normal tissue. In this study, a novel human variable domain of a heavy-chain (VH) antibody fragment specific to FRa was enriched and selected by phage bio-planning. The positive phage clone (3A102 VH) specifically bound to FRa and also cross-reacted with FRb, as tested by ELISA. Clone 3A102 VH was then successfully expressed as a soluble protein in an E. coli shuffle strain. The obtained soluble 3A102 VH demonstrated a high affinity for FRa with affinity constants (K aff ) values around 7.77 ± 0.25 Â 10 7 M À1 , with specific binding against both FRa expressing NSCLC cells and NSCLC patient-derived primary cancer cells, as tested by cell ELISA. In addition, soluble 3A102 VH showed the potential desired property of a targeting molecule by being internalized into FRa-expressing cells, as observed by confocal microscopy. This study inspires the use of phage display to develop human VH antibody (Ab) fragments that might be well suited for drug targeted therapy of NSCLC and other FRapositive cancer cells.

A cost-effective strategy for superfine bacterial nanocellulose (BNC) production was successfully developed by the low-nutrient adaptive mutation. Two adapted strains, RC30-15 and RC37-23 were obtained from revertant strain R37-9 of Komagataeibacter oboediens MSKU 3 by a repetitive static cultivation at 30°C and 37°C, respectively. The repetitive cultivation was carried out in coconut water (CW) containing 1% acetic acid and 2% ethanol (CW1A2E), CW1A2E containing 0.5% sucrose (CW1A2E0.5S) and CW1A2E0.5S containing 0.5% ammonium sulfate (CW1A2E0.5S0.5N) for 30 passages (210 days). Strain R37-9 produced relatively low amount of superfine BNC of 0.71, 0.88 and 0.82 g/L dry weight after 7 days static cultivation at 37°C in CW1A2E, CW1A2E0.5S and CW1A2E0.5S0.5N, respectively. Two adapted strains exhibited higher BNC producing ability in coconut water than strain R37-9. Strains RC30-15 and RC37-23 produced the highest BNC yields of 3.63 and 8.22 g/L dry weight in CW1A2E0.5S and CW1A2E0.5S0.5N under static cultivation at 30°C and 37°C, respectively. SEM images of the nanofibrils produced from strain RC37-23 showed the finer nanocellulose fibrils and narrower range (24±0.47-34±0.81 nm) of fibril width compared with other strains. Furthermore, the density, moisture content and porosity of nanocellulose fibrils produced from strain RC37-23 in CW1A2E0.5S0.5N medium at 37°C exhibited the highest density (0.86±0.02 g/cm3) and moisture content (12.51±1.87 %). BNC from strain RC37-23 grown in CW1A2E0.5S0.5N medium at 37°C also possessed the lowest porosity (42.59±1.70%). It could be concluded that low-nutrient adapted strain at 37°C, strain RC37-23, produced not only the highest amount of BNC but also the better physicochemical properties of nanocellulose fibrils.