Non-small cell lung cancer (NSCLC) is the primary subtype of lung cancer. Long non-coding RNAs (lncRNAs) have been reported to serve prominent roles in cancer progression. However, the expression patterns and potential roles of lncRNAs in NSCLC remain to be elucidated. In the present study, four public datasets were analyzed to identify differentially expressed lncRNAs (DElncs) in NSCLC. A further dataset, GSE19188, was analyzed to validate the findings. A total of 38 upregulated and 31 downregulated lncRNAs were identified in NSCLC, compared with samples from healthy controls. Among these, 12 lncRNAs were associated with the progression of NSCLC, and dysregulated between high grade (stage III and IV) and low grade (stage II) NSCLC samples. Moreover, dysregulation of lncRNA-SIGLEC17P, GGTA1P, A2M-AS1, LINC00938, GVINP1, LINC00667 and TMPO-AS1 was associated with overall survival time in patients with NSCLC. Co-expression analyses, combined with the construction of protein-protein interaction networks, were performed to reveal the potential roles of key lncRNAs in NSCLC. The present study revealed a series of lncRNAs involved in the progression of NSCLS, which may serve as novel biomarkers for the disease.

(2016) Characterization of alanine to valine sequence variants in the Fc region of nivolumab biosimilar produced in Chinese hamster ovary cells, mAbs, 8:5, 951-960, DOI: 10.1080/19420862.2016 To link to this article: https://doi.org/10. 1080/19420862.2016 ABSTRACTNivolumab is a therapeutic fully human IgG4 antibody to programmed death 1 (PD-1). In this study, a nivolumab biosimilar, which was produced in our laboratory, was analyzed and characterized. Sequence variants that contain undesired amino acid sequences may cause concern during biosimilar bioprocess development. We found that low levels of sequence variants were detected in the heavy chain of the nivolumab biosimilar by ultra performance liquid chromatography (UPLC) and tandem mass spectrometry. It was further identified with UPLC-MS/MS by IdeS or trypsin digestion. The sequence variant was confirmed through addition of synthetic mutant peptide. Subsequently, the mixing base signal of normal and mutant sequence was detected through DNA sequencing. The relative levels of mutant A424V in the Fc region of the heavy chain have been detected and demonstrated to be 12.25% and 13.54%, via base peak intensity (BPI) and UV chromatography of the tryptic peptide mapping, respectively. A424V variant was also quantified by real-time PCR (RT-PCR) at the DNA and RNA level, which was 19.2% and 16.8%, respectively. The relative content of the mutant was consistent at the DNA, RNA and protein level, indicating that the A424V mutation may have little influence at transcriptional or translational levels. These results demonstrate that orthogonal state-of-the-art techniques such as LC-UV-MS and RT-PCR should be implemented to characterize recombinant proteins and cell lines for development of biosimilars. Our study suggests that it is important to establish an integrated and effective analytical method to monitor and characterize sequence variants during antibody drug development, especially for antibody biosimilar products.

The epigenetic remodeling of chromatin through histone modifications has been widely implicated in drug resistance of cancer cells. However, whether epigenetic mechanisms contribute specifically to doxorubicin resistance in leukemia has not been carefully examined. Using a stable and sensitive workflow based on LC-MS, we quantitatively compared the extents of methylation and acetylation of histone H3 and H4 in acute leukemia cell line HL60 and its doxorubicin-resistant derivative, HL60/ADR, as well as the chronic leukemia cell line K562 and its doxorubicin-resistant derivative, K562/ADR. We found that increased levels of H3K9 methylation, H3K14, H3K18 and H3K23 acetylation, and potentially H4K20 methylation, are associated with drug resistance in both cells. Our results demonstrated that the doxorubicin-resistant acute and chronic leukemia cell lines may share a common epigenetic mechanism that involves a combination of transcriptional activation and silencing.

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