Background: Multidrug resistance (MDR) is one of the reasons for treatment failure in oral squamous cancer patients; however, the MDR mechanisms remain elusive. Methods: Two human oral squamous cell carcinoma (OSCC) cell lines, CAL27 and SCC9, were analyzed by stepwise selection upon exposure to 5-fluorouracil (5-FU) and cisplatin (CDDP) for MDR cell line establishment, and cell viability was analyzed by CCK8 assays. Transcriptomes of the CAL27 and CAL27-MDR cells were analyzed by RNA-seq assay. The molecules in Sonic hedgehog (Shh) signal pathway and MDR related pathway were selected for validation by qRT-PCR and Western blot. Human OSCC tissues were applied for immunohistochemical and clinicopathological analysis. Results: The OSCC-MDR cell lines with resistance to 5-FU and CDDP were successfully established. Protein expression levels of ATP-binding cassette (ABC) transporter ABCC1 and ABCG2 were increased 1.6-fold and 2.1-flod, respectively, in OSCC specimen from the patients with chemotherapy. The RNA-seq assay speculated the activation of Hedgehog (Hh) signaling with the upregulation of SHH, PTCH1, and SMO in OSCC-MDR cells as compared with OSCC cells. Furthermore, immunohistochemical studies confirmed that the high expression of SHH, PTCH1, and SMO in OSCC patients was significantly associated with chemotherapy. Overexpression of SHH increased the chemoresistance in OSCC cells, while the mRNA expression levels of PTCH1 and ABCG2 were increased in OSCC cells upon stimulation with recombinant SHH protein. Conclusions: These results revealed that the activation of Hh signaling pathway regulating ABC transporters is associated MDR in OSCC.

The purpose of this study was to optimize a peptide (nABP284) that binds to PD-1 by a computer-based protocol in order to increase its affinity. Then, this study aimed to determine the inhibitory effects of this peptide on cancer immune escape by coculturing improving cytokine-induced killer (ICIK) cells with cancer cells. Materials and MethodsnABP284 that binds to PD-1 was identified by phage display technology in our previous study.AutoDock and PyMOL were used to optimize the sequence of nABP284 to design a new peptide (nABPD1). Immunofluorescence was used to demonstrate that the peptides bound to PD-1. Surface plasmon resonance (SPR) was used to measure the binding affinity of the peptides. The blocking effect of the peptides on PD-1 was evaluated by a neutralization experiment with human recombinant PD-L1 protein. The inhibition of activated lymphocytes by cancer cells was simulated by coculturing of human acute T lymphocytic leukemia cells (Jurkat T cells) with human tongue squamous cell carcinoma cells (Cal27 cells). The anticancer activities were determined by coculturing ICIK cells with Cal27 cells in vitro. ResultsA high-affinity peptide (nABPD1, KD=11.9 nM) for PD-1 was obtained by optimizing the nABP284 peptide (KD=11.8 µM). nABPD1 showed better efficacy than nABP284 in terms of increasing the secretion of IL-2 by Jurkat T cells and enhancing the in vitro antitumor activity of ICIK cells. ConclusionnABPD1 possesses higher affinity for PD-1 than nABP284, which significantly enhances its ability to block the PD-1/PD-L1 interaction and to increase ICIK cell-mediated antitumor activity by armoring ICIK cells.

Nickel-based superalloys are widely used in aerospace and other fields for their superior performance. PCBN is an excellent tool material for cutting superalloys because of its excellent cutting performance. To study the wear mechanism of PCBN tools with different coatings (Uncoated, TiN, and TiAlN) for machining superalloy GH4202 under different cutting conditions, cutting tests were carried out at a wide range of cutting speeds (vc=50-400m/min). Two different cutting conditions, dry cutting, and wet cutting were also introduced. The results showed that the coating can reduce tool wear in dry cutting at a range of speeds (vc =50-200m/min). The coating has the opposite effect when cutting coolant is added. Wear mechanisms vary at different cutting speeds. At high cutting speeds (vc =200-400m/min) coatings and cutting coolant have little effect on tool wear. The TiN coating is the most sensitive to the cutting coolant and the uncoated tool is the most stable. Significant deposition of wear products can be observed at high cutting speeds with the addition of cutting coolant.

The purpose of this study was to optimize a peptide (nABP284) that binds to PD-1 by a computer-based protocol in order to increase its affinity. Then, this study aimed to determine the inhibitory effects of this peptide on cancer immune escape by coculturing improving cytokine-induced killer (ICIK) cells with cancer cells. Materials and MethodsnABP284 that binds to PD-1 was identified by phage display technology in our previous study.AutoDock and PyMOL were used to optimize the sequence of nABP284 to design a new peptide (nABPD1). Immunofluorescence was used to demonstrate that the peptides bound to PD-1. Surface plasmon resonance (SPR) was used to measure the binding affinity of the peptides. The blocking effect of the peptides on PD-1 was evaluated by a neutralization experiment with human recombinant PD-L1 protein. The inhibition of activated lymphocytes by cancer cells was simulated by coculturing of human acute T lymphocytic leukemia cells (Jurkat T cells) with human tongue squamous cell carcinoma cells (Cal27 cells). The anticancer activities were determined by coculturing ICIK cells with Cal27 cells in vitro. ResultsA high-affinity peptide (nABPD1, KD=11.9 nM) for PD-1 was obtained by optimizing the nABP284 peptide (KD=11.8 µM). nABPD1 showed better efficacy than nABP284 in terms of increasing the secretion of IL-2 by Jurkat T cells and enhancing the in vitro antitumor activity of ICIK cells. ConclusionnABPD1 possesses higher affinity for PD-1 than nABP284, which significantly enhances its ability to block the PD-1/PD-L1 interaction and to increase ICIK cell-mediated antitumor activity by armoring ICIK cells.

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