Fas expression and function in normal and malignant breast cell lines.

Expression and function of the Fas apoptotic pathway was investigated in normal and malignant human breast epithelial cells. Nontransformed mammary epithelial cell lines all expressed high levels of Fas mRNA and protein, but only one of seven breast cancer cell lines (T47D) expressed high levels of Fas. Apoptosis was induced in the nontransformed lines when they were incubated with the anti-Fas antibody. However, all of the breast cancer cell lines tested, except T47D, were resistant to Fas-mediated apoptosis. Four of five Fas-resistant breast cancer cell lines became sensitive to Fas-mediated apoptosis upon treatment with IFN-gamma. Fas mRNA increased slightly in both cell lines that became sensitive and in the cell line that remained resistant to Fas-mediated apoptosis upon IFN-gamma treatment. However, the cell surface expression of Fas showed little or no increase in any of the cell lines tested upon IFN-gamma treatment. In contrast to Fas expression, interleukin-1beta-converting enzyme (ICE) expression increased only in the cell lines that became Fas sensitive after IFN-gamma treatment. The importance of ICE and/or ICE-like proteases in Fas-mediated apoptosis in these cells was confirmed by inhibition of Fas-mediated apoptosis by a specific ICE inhibitor, YVAD-cmk. Fas sensitivity was reconstituted in the IFN-gamma-resistant cell line by transfection of ICE into that cell line. Together, these data suggest that down-regulation of Fas and its pathway may be a step in tumor progression and that modulation of Fas expression may provide an approach to inducing apoptosis in breast cancer cells.

The protein tyrosine phosphatase DEP-1 is induced during differentiation and inhibits growth of breast cancer cells.

Sodium butyrate-induced differentiation of breast cancer cell lines was used to identify protein tyrosine phosphatases (PTPs) involved in differentiation and growth inhibition of breast cancer cells. Of 42 PTPs analyzed, 31 were expressed in the ZR75-1 breast cancer cell line. Expression of four PTPs (DEP-1, SAP, PTP gamma, and PAC) was regulated in ZR75-1 cells undergoing differentiation. Expression of two of these PTPs (DEP-1 and SAP) was also regulated in the SKBr-3 cell line undergoing differentiation. In view of its marked induction with differentiation in an estrogen receptor (ER)-positive and an ER-negative breast cancer cell line, DEP-1 was investigated for a role in growth inhibition or induction of differentiation in breast cancer cells. A DEP-1 cDNA construct under control of a constitutively active cytomegalovirus promoter was transfected into the ZR75-1, SKBR-3, and MCF-7 breast cancer cell lines, and resistant colonies were selected with G418. DEP-1 expression inhibited the development of resistant colonies by 3-5-fold in all three lines compared to transfection with vector alone. Three stable MCF-7 cell lines expressing DEP-1 under control of an inducible metallothionein promoter were then established. In these lines, induction of DEP-1 expression inhibited breast cancer cell growth by 5-10-fold. These data describe PTPs expressed and regulated in breast cancer cell lines during differentiation and identify one PTP, DEP-1, that inhibits the growth of breast cancer cells in vitro.

Postoperative radiotherapy for locally advanced colon cancer.

BACKGROUND: The role of adjuvant postoperative radiotherapy for locally advanced colon cancer is not well documented. METHODS: Seventy-eight patients who underwent a complete resection of B2-C colon cancer received postoperative radiotherapy. Twenty-eight patients received < or = 45 Gy; 50 patients received 50-55 Gy. Twenty-seven patients received adjuvant fluorouracil-based chemotherapy. All patients were followed for a minimum of 3 years; no patients were lost to follow-up. RESULTS: The overall local control rate was 88%. The 5-year actuarial rate of local control was 96% after 50-55 Gy postoperative radiotherapy compared with 76% after < 50 Gy (p = 0.0095). Multivariate analysis of local control showed that only radiotherapy dose significantly influenced this end point. Cause-specific survival rates at 5 years were B2, 67%; B3, 90%; C1, 100%; C2, 61%; C3, 36%; and overall, 63%. Multivariate analysis of cause-specific survival showed that only stage significantly influenced this end point. Bowel obstruction caused by adhesions developed in three patients and required a laparotomy; radiation-induced sarcoma developed in one additional patient. CONCLUSIONS: Postoperative radiotherapy appears to reduce the risk of local recurrence in patients with locally advanced colon cancer. The optimal dose is probably 50-55 Gy at 1.8 Gy per fraction. Postoperative radiotherapy may improve cause-specific survival for patients with stages B3 and C2 cancers.

Stage IB or IIA-B carcinoma of the intact uterine cervix treated with irradiation: a multivariate analysis.

Although treatment results for Stage IB-IIA-B carcinoma of the cervix are generally stratified only by stage, several authors have found that other parameters such as tumor size, patient age, histology, and pretreatment hematocrit may influence pelvic control and/or survival. This is an analysis of 306 patients with carcinoma of the cervix treated with irradiation alone at the University of Florida between October 1964 and June 1984. Results were analyzed for the end points of pelvic control, distant metastasis, relapse-free survival, and overall survival. Stage for stage, there was a decrease of at least 20 percentage points in pelvic control rates of tumors greater than or equal to 6 cm versus those of tumors 0 to 3 cm in diameter, by univariate analysis; a similar pattern was also observed for the end point of relapse-free survival. When patients were stratified by Stages IB-IIA (greater than or equal to 6 cm and less than 6 cm) and IIB (greater than or equal to 6 and less than 6 cm), there was a clear pattern of improved pelvic control and relapse-free survival for patients over 50 years old and for patients with pretreatment hematocrits greater than 40%. The parameters of stage, tumor size, patient age, histology, and pretreatment hematocrit were evaluated in a multivariate analysis. For the end points of pelvic control, distant metastasis, and relapse-free survival, only tumor size was of independent prognostic significance for all three end points with p-values of 0.022, 0.003, and 0.0006, respectively. Stage did not show independent prognostic significance for any of these end points with p-values of 0.257, 0.878, and 0.284, respectively. The data suggest that tumor size is an important prognostic factor and should be incorporated into the reporting of cervical cancer treatment results.

A technique for postoperative irradiation of carcinomas of the larynx and hypopharynx.

Postoperative radiation is commonly employed for advanced lesions of the larynx and hypopharynx which have undergone a laryngectomy. It is technically difficult to achieve a homogeneous distribution of irradiation throughout the treatment volume because of the marked variation in contour across the treated area. We have described a technique which employs a 15 degrees lateral kick-out of the treatment table and a 15 degrees gantry angle above the horizontal for each of two lateral fields. This technique has certain advantages over other techniques previously described in the literature. By adding a gantry angle of 15 degrees above the horizontal to the kick-out lateral position of the table, we have found that we were able to decrease the amount of irradiation to the shoulder, to improve the dose to the posterior superior mediastinum, to lower the applied dose, and to avoid a hot spot overlying the spinal cord in the superior posterior portion of the field. This technique is particularly useful in patients who lack the flexibility to move their shoulders posteriorly and inferiorly.

Odontoid fractures treated by anterior odontoid screw fixation.

While odontoid fractures are common injuries, disagreement exists regarding treatment. Some authors claim a high rate of pseudoarthrosis and have therefore recommended early posterior fixation and fusion. This, however, results in decreased cervical rotation. Therefore, it has been recommended that a more direct approach to the fracture be taken. Results on anterior screw fixation in 14 patients are reported. The technique was found to be especially useful in multiple trauma patients, patients who refuse halo treatment, and in some nonunions.

Carbohydrate metabolism and capillary basement-membrane thickness in children. I. cross-sectional studies.

Thirty-nine children from three to 16 years of age were included in this study. Nineteen were diabetics, seven were "suspected" diabetics (with evidence of glucose intolerance but without repeated fasting hyperglycemia), and 13 were controls. Mean glucose disappearance rates (K) during intravenous glucose tolerance tests (IVGTTs) were 2.19 for the controls, 1.23 for the suspected diabetics, and 0.70 for 14 diabetics tested; the differences were statistically significant. Diabetics had the smallest and suspected diabetics the greatest plasma insulin responses during IVGTTs. Fasting plasma growth hormone (GH) varied widely. GH generally decreased or remained unchanged during IVGTTs, but two diabetics exhibited slight increases and two sustpected diabetics pronounced increases. Basement-membrane thickness (BMT) was examined in 42 quadriceps femoris needle biopsies. Average BMT (ABMT) and minimum BMT (MBMT) correlated well (r = 0.91). BMT did not correlate well with age or, in the diabetics, with duration of clinical disease. Diabetics had the greatest and controls the least mean ABMT and MBMT, but the differences were not statistically significant. High values (those exceeding mean control values by more than two standard deviations) were much more common among the suspected diabetics and the diabetics. One of 13 controls, three of six suspected diabetics, and six of 19 diabetics had high ABMT values; two suspected diabetics and five diabetics had high MBMT values. Correlations between BMT and K were negative for the most part, but correlation coefficients were small. Serial studies in four of the children suggest that BMT and glucose tolerance tend to change in opposite directions.

Carbohydrate metabolism and capillary basement-membrane thickness in children. II. Longitudinal studies.

Longitudinal biochemical and histologic studies were carried out in 11 children receiving oral hypoglycemic agents. There were five "suspected" diabetics (with evidence of glucose intolerance but without repeated fasting hyperglycemia) and six diabetics. Mean fasting plasma glucose (FPG) values showed no significant change during treatment with phenformin alone. The mean FPG decreased significantly within six to 10 weeks after addition of tolazamide to the regimen, but the decrease was not sustained during long-term observation (seven months to four years). Glucose disappearance rate (K) generally increased as FPG decreased, but the number of observations was smaller, and mean values showed no significant change. Mean values for fasting plasma insulin and for peak insulin response to intravenously administered glucose did not change significantly. Changes in capillary basement membrane thickness (BMT) were found to be statistically significant in a number of individual instances. Decreasing BMTs were associated with increasing Ks and vice versa. A similar trend was apparent among other patients, in whom individual changes in BMT were not statistically significant. The pooled data were therefore subjected to chi-square analysis; K and average BMT were found to change in opposite directions (P less than 0.001); a similar relationship held for K and minimum BMT (P less than 0.05). But K and BMT did not correlate well as regards magnitude of change. Influences of phenformin and tolazamide on these changes could not be evaluated. Both BMT and K may be influenced by many complex variables, but the present findings indicate that glucose tolerance and BMT have a close interdependence.