Emerging roles of the ribonucleotide reductase M2 in colorectal cancer and ultraviolet-induced DNA damage repair

Figure 5 Light-microscopic photograph of cellular morphology. A: After 48 h of culture in normal conditions or exposed to ultraviolet (UV), HCT116 cells [high expression level of ribonucleotide reductase M2 (RRM2)] and SW480 cells (low expression level of RRM2) were photographed (20 × magnification). With UV-C irradiating, SW480 cells formed spheroids and HCT116 cells still adhered to each other and attached; B: Expression of RRM2 mRNA in clinical tissue specimens. Polymerase chain reaction analyses of 25 colorectal cancer patients (we show 6 patients) showed the expression levels of RRM2. PT: Protrude type; UT: Ulcerative type; as-ca: Adenocarcinoma.