These xenograft lines were categorized according to whether they were highly, moderately, minimally, or non invasive (Figure S2).
A total of 16 and 30 cell lines were categorized respectively as sensitive and resistant to selenium in the NCI60 cell line panel (Figure 1, Table 1).
Forty seven cell lines were categorized as sensitive and 309 cell lines as insensitive.
Using the panel's GI50 response data available from Developmental Therapeutics Program, cell lines were categorized as either sensitive or resistant.
For simplicity, the cell lines were categorized into one of four groups and are designated as either ASS1-high, medium, low or negative (Table 1).
A total of 44 human breast cancer cell lines and three immortalized breast epithelial lines were categorized as representing luminal or basal breast cancer subtypes based on the relative gene expression of cytokeratin 8/cytokeratin 18 and cytokeratin 5/cytokeratin 17, respectively [ 31, 32].
A total of 25 mutant lines were categorized in this class and we further distinguished two subgroups, a first group of 19 alleles strongly interacting genetically and a second group of six single alleles that will not be described further.
The GM2 expression levels in these cell lines were categorized into three groups based on the relative fluorescence intensity: high (>10) in four cell lines (36%); low (2 10) in four cell lines (36%); and negative (<2) in three cell lines (28%) (Fig. 1).
According to the immunohistochemical intrinsic subtypes, the KPL-1 and KPL-3C cell lines were categorized as the luminal A subtype, the BT-474 cell line as the luminal B subtype, the KPL-4 cell line as the HER2-positive/ER-negative subtype, and the MDA-MB-231, MD-MB-157 and HCC1937 cell lines as the basal-like subtype [ 3].
When cell lines were categorized into those with high HRG expression (HRG-high) and low HRG expression (HRG-low) using a cutoff equal to the median of the blinded sample data, HRG-high cell lines were significantly more sensitive to patritumab treatment compared with HRG-low cell lines, both in vitro (P = 0.002) and in tumor xenograft models.
