Galectin-14 promotes hepatocellular carcinoma tumor growth via enhancing heparan sulfate proteoglycan modification

Hepatocellular carcinoma(HCC)is a highly heterogeneous malignancy and lacks effective treatment.Bulk-sequencing of different gene transcripts by comparing HCC tissues and adjacent normal tissues provides some clues for investigating the mechanisms or identifying potential targets for tumor progression.However,genes that are exclusively expressed in a subpopulation of HCC may not be enriched or detected through such a screening.In the current study,we performed a single cell-clone-based screening and identified galectin-14 as an essential molecule in the regulation of tumor growth.The aberrant expression of galectin-14 was significantly associated with a poor overall survival of liver cancer patients with database analysis.Knocking down galectin-14 inhibited the proliferation of tumor growth,whereas overexpressing galectin-14 promoted tumor growth in vivo.Non-targeted metabolomics analysis indicated that knocking down galectin-14 decreased glycometabolism;specifically that glycoside synthesis was significantly changed.Further study found that galectin-14 promoted the expression of cell surface heparan sulfate proteoglycans(HSPGs)that functioned as co-receptors,thereby increasing the responsiveness of HCC cells to growth factors,such as epidermal growth factor and transforming growth factor-alpha.In conclusion,the current study identifies a novel HCC-specific molecule galectin-14,which increases the expression of cell surface HSPGs and the uptake of growth factors to promote HCC cell proliferation.

Improving antibody affinity through in vitro mutagenesis in complementarity determining regions

High-affinity antibodies are widely used in diagnostics and for the treatment of human diseases.However,most antibodies are isolated from semi-synthetic libraries by phage display and do not possess in vivo affinity maturation,which is triggered by antigen immunization.It is therefore necessary to engineer the affinity of these antibodies by way of in vitro assaying.In this study,we optimized the affinity of two human monoclonal antibodies which were isolated by phage display in a previous related study.For the 42A1 antibody,which targets the liver cancer antigen glypican-3,the variant T57H in the second complementarity-determining region of the heavy chain(CDR-H2)exhibited a 2.6-fold improvement in affinity,as well as enhanced cell-binding activity.For the I4A3 antibody to severe acute respiratory syndrome coronavirus 2,beneficial single mutations in CDR-H2 and CDR-H3 were randomly combined to select the best synergistic mutations.Among these,the mutation S53P-S98T improved binding affinity(about 3.7 fold)and the neutralizing activity(about 12 fold)compared to the parent antibody.Taken together,single mutations of key residues in antibody CDRs were enough to increase binding affinity with improved antibody functions.The mutagenic combination of key residues in different CDRs creates additive enhancements.Therefore,this study provides a safe and effective in vitro strategy for optimizing antibody affinity.