To elucidate the difference between scirrhous and non-scirrhous gastric carcinomas, we examined the expressions of TGF-beta, procollagen type I and type III in 7 gastric carcinoma cell lines and 37 gastric carcinoma tissues, and also examined the effect of TGF-beta on the expression of procollagen mRNA by TMK-I cells. TGF-beta mRNA was detected in all the tumors examined in vivo and in vitro. Interestingly, 9 (90%) of 10 scirrhous gastric carcinomas revealed higher levels of TGF-beta mRNA than normal tissues, while 8 (38%) of 21 well-differentiated adenocarcinomas had higher TGF-beta mRNA levels than normal tissues. As for procollagen mRNA, most of the human gastric carcinoma cell lines expressed type-I procollagen mRNA and MKN-I expressed type-III procollagen mRNA. Furthermore, procollagen type-I mRNA accumulation in TMK-I cells was increased by exogenous TGF-beta. Most of the tumor tissues from surgical specimens expressed higher procollagen mRNA than normal tissues. These results indicate that TGF-beta produced by carcinoma cells might stimulate collagen synthesis not only by fibroblasts but also by carcinoma cells themselves, leading to diffuse fibrosis of scirrhous gastric carcinomas.

In order to ascertain autocrine growth factors in esophageal carcinomas, we analysed expression of mRNAs and proteins for epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha) and epidermal growth factor receptor (EGFR) in 6 esophageal carcinoma cell lines. Gene alterations were also examined. All of the esophageal carcinoma cell lines expressed mRNA for EGFR and TGF-alpha genes. Interestingly, EGF mRNA of about 5.0 kb was also detected in TE-1, TE-2, and TE-8 cells. Production of protein was also confirmed by binding assay and ELISA on 3 of the 6 cell lines. The cells had a relatively high number of EGFRs and produced TGF-alpha and EGF protein at the same time. Furthermore, anti-EGF (KEM-10) and anti-TGF-alpha (WA-3) monoclonal antibodies (MAbs) inhibited spontaneous uptake of tritiated thymidine (3H-TdR) by TE-1 cells which expressed EGF, TGF-alpha and EGFR mRNA and protein. These results strongly suggest that EGF and/or TGF-alpha produced by carcinoma cells function as autocrine growth factors for human esophageal carcinomas.

Relationship between epidermal growth factor receptor (EGFR) status and various prognostic factors was investigated in 91 human breast cancer tissues. Epidermal growth factor receptor was measured by biochemical competitive binding assay using iodine 125 epidermal growth factor (125I)-EGF. The EGFR status was not correlated with axillary lymph node involvement, tumor size, stage, and histologic type, but significantly correlated with histologic grading (P less than 0.05) and lymphatic invasion (P less than 0.01). Between EGFR and estrogen receptor (ER) status, a clear inverse relationship was observed (P less than 0.01). The Ki-67-positive stained cell rate, which reveals the proportion of cycling cells, was significantly higher in EGFR-positive tumor tissues than in EGFR-negative cases. Furthermore, preliminary postoperative survey demonstrated a high tendency of recurrence rate of patients with EGFR-positive tumors as compared with those with EGFR-negative tumors. These data suggest that EGFR status may be important for the prediction of biologically high malignant potential.

The expressions of mRNA for epidermal growth factor (EGF), transforming growth factor‐α (TGF‐α) and EGF receptor (EGFR) genes were examined in 7 human gastric carcinoma cell lines and 15 gastric carcinoma tissues and the corresponding normal mucosas. All of the gastric carcinoma cell lines expressed mRNA for EGFR and TGF‐α genes. TMK‐1 and MKN‐28 cells also expressed EGF mRNA. Production of EGF, TGF‐α and EGFR protein by gastric carcinoma cell lines was also confirmed by EGF and TGF‐α specific monoclonal antibody binding. As for surgical specimens, EGFR and TGF‐α mRNA were detected at high levels in all the tumor tissues. Interestingly, EGF mRNA was detected in 5 (33.3%) of the 15 gastric carcinomas but it was not detected in normal tissues. Moreover, anti‐EGF and anti‐TGF‐α monoclonal antibodies inhibited the spontaneous 3H‐TdR uptake by gastric carcinoma cells. These results suggest that EGF and/or TGF‐α produced by tumor cells act as autocrine growth factors for gastric carcinomas.

Expression of epidermal growth factor receptor (EGFR) and estrogen receptor (ER) was examined by an immunocytochemical assay (ICA) using serial cross-sections of human breast cancer tissues. Immunocytochemical results were compared with those obtained by biochemical competitive binding assay and with histological lymphatic invasion. EGFR was evaluated as positive in 17 (34.0%) out of 50 primary tumors by ICA. A significant inverse relationship of the proportion of stained cells between EGFR and ER was demonstrated. In more than one-half of the tumors that were positive for both EGFR and ER, these 2 receptors were inversely stained in relation to the distribution. In ER-negative cells, EGFR expression was more marked than in ER-positive cells. Biochemical data confirmed the immunocytochemical results, pointing to an inverse relationship between EGFR and ER content. EGFR status correlated well with the degree of lymphatic invasion but not with the number of lymph nodes with metastases.