Table 1.

List of cell lines and tumours used in the present study and their main characteristics

In vitro experiments
Cell line name	C6 wt	C6 parental	C6 DDAH
Description	Wild-type C6 cells	C6 cells with pTet-Off element (parental to C6 DDAH cells)	DOX-inducible DDAH I overexpressing C6 cells
DOX	Independent	Independent	Absence (− DOX)	Presence (+ DOX)
DDAH I expression	Low endogenous expression	Low endogenous expression	Overexpression	Low endogenous expression
NO production	Increased by cytokines	Negligible (cytokine independent)	Negligible (cytokine independent)	Negligible (cytokine independent)
VEGF expression	Endogenous	Endogenous	Low	Low

In vivo experiments
Tumour type	C6 DDAH group A (from cells grown in normal medium)		C6 DDAH group B (from cells grown in medium with DOX)		D27
Description	DOX-inducible DDAH I overexpressing C6 cells		DOX-inducible DDAH I overexpressing C6 cells		Constitutively DDAH I overexpressing C6 cells
DOX	Absence (− DOX)	Presence (+ DOX)	Absence (− DOX)	Presence (+ DOX)	Independent
DDAH I expression	Overexpression	Low endogenous expression	Overexpression	Low endogenous expression	Overexpression
NO production	Negligible	Negligible	Negligible	Negligible	High
VEGF expression	Low	Low	Low	Low	Very high