Characterisation of novel lung cancer cell lines for immuno-inhibitory markers

The present study investigates the expression of immune biomarkers, PD-L1 and HLA-1 on novel lung cancer cell lines (H838, H838-EGFR, A549, A549-ALK, HCC 827, NCI 1650, TWIT, Jacket). PD-L1 and HLA-1 characterisation were initially performed and analysed via flow cytometry. These results showed that the expression of PD-L1 and HLA-1 varies across the cell lines from high percent to low. The effect of IFNy on biomarkers expression was also investigated following a 48 hour incubation period. of the cell lines analysed the expression of PD-L1 increases with IFNy stimulation whilst HLA-1 remains relatively unchanged. Trypan blue assays for cell viability were performed, showing that when stimulated, cells were 100% viable whereas viability decreases upon IFNy exposure

Flow cytometric phenotyping of diverse human cancer cell lines for immunological biomarkers expression

The tumour microenvironment contains a variety of distinct factors that inhibit the immune system and can cause drug resistance. Some of these factors include the expression of cell surface markers which interact directly with immune cells. Cancer cells express programmed death ligand 1 (PD-L1) and reduce the expression of major-histocompatibility complex class I, death-receptors 4/5 and Fas, limiting immune-mediated cancer cell killing. Targeting these immune markers alone or in combination could potentially increase cancer cell death and improve drug efficacy. Utilising flow cytometric analysis on breast, prostate and colorectal cancer cell lines, we have found differential expression of these markers depending on the cancer type. These findings provide a platform for future work that will entail siRNA knockdown of PD-L1 to determine the tumour-intrinsic role of this ligand, in addition to combination therapies in 2D and 3D cell culture

Programmed death-ligand 1 expression in human cancer cell lines in two-dimensional and three-dimensional cell culture systems

Solid tumours are characterised by a three-dimensional (3D) architecture that provides specific survival advantages such as resistance to anti-cancer drugs. The expression of programmed death-ligand 1 (PD-L1) is one such survival mechanism employed by tumours to mediate immune evasion, drug resistance and tumour progression. Here we investigated whether the expression of PD-L1 by human cancer cell lines altered in a 3D cell culture setting as opposed to their two-dimensional (2D) monolayer counterparts. We utilised well-established 3D cell culturing systems that facilitate the formation of spheroids and display heterogeneous populations of cells resembling that found in the tumour microenvironment, to assess PD-L1 expression. We found that PD-L1 expression changed in human breast, prostate and colorectal cancer cell lines in 3D cell culture systems when compared to their 2D counterparts. The level of expression of PD-L1 by tumour cells in 3D cell culture is more likely to mimic that of an in vivo tumour microenvironment than 2D cell culture, and may better able the investigation of the tumour-intrinsic role of PD-L1