Proliferative responses of ESCC cell lines to HEF75 and HEF75-hTERT fibroblast supernatants. (A) KYSE30, KYSE220, TE-11, and TE-14 show significantly increased cell proliferation until a one-half dilution, as compared with the control group. For each cell line, the P- value is less than 0.001 on one-way analysis of variance. Dunnet’s test was used for comparison with the control group, and P-values were calculated. The Y axis indicates the absorbance. (B) Supernatants from HEF75-hTERT also significantly stimulate the proliferation of KYSE220, TTN, TE-11 and TE-14 cell lines. (C) Proliferative responses of 22 ESCC cell lines to fibroblast supernatants. With normal esophagus fibroblast supernatant (HEF75), 1.25-fold or higher proliferation is induced in 12 cell lines. With immortalized esophageal fibroblast (HEF75-hTERT) supernatant, 1.25-fold or higher proliferation is induced in 21 cell lines. The proliferation rate compared to controls is shown by a graduated color scale (lower panel). Fold change by HEF75 or HEF75-hTERT is the ratio of the results of the proliferation assay after addition of HEF 75 or HEF75-hTERT as compared with the control. A 1.25 fold or higher increase in proliferation as compared with control is highlighted in green. The data shown are the mean values of two or more independent experiments for each cell line.