Effect of recombinant human interferon-alpha 2b on receptors for steroid hormones and epidermal growth factor in patients with endometrial cancer

A comparison of the safety and efficacy of ondansetron versus granisetron as prophylaxis against chemo/ radiotherapy-induced nausea and vomiting in bone marrow transplantation patients. A double-blinded, randomized, prospective, pilot study

Introduction. Nausea and vomiting (N&V) are well known and distressing side effects of chemoradio therapy. Conditioning protocols for patients undergo ing bone marrow transplantation (BMT) consist of highly emetogenic high-dose chemotherapy with or without total body irradiation (TBI). The 5HT3 (sero tonin receptor) antagonists heralded a marked im provement in controlling chemotherapy-induced N&V. Ondansetron and granisetron have been avail able for some time with limited information available concerning their pharmacological and pharmacoeco nomic differences and patient acceptability.

Patients and Methods. This pilot study initiated comparison of the two drugs and evaluated the antiemetic efficacy and safety of a single daily dose of ondansetron, 16 mg, plus dexamethasone, 10 mg, compared to granisetron, 3 mg, plus dexamethasone, 10 mg, in patients receiving high dose chemotherapy (±TBI), prior to BMT. The 12-month pilot study was double-blinded, randomized, and prospective. A non- homogenous cohort of 23 patients (10 receiving ondansetron and 13 granisetron) were enrolled.

Results. No significant differences in the efficacy of the two protocols were observed. In each arm about 50% of the patients had a complete response, and a similar number had a major response.

Side Effects. The most common adverse events reported during the study included diarrhea and head ache. No patients were withdrawn due to side effects.

Conclusions. Our preliminary findings suggest that both of these two antiemetic protocols are safe and similarly effective in preventing chemotherapy-induced emesis in patients receiving BMT conditioning.

Discussion. Further evaluation in a multicenter study should now be made to compare efficacy, safety, cost-effectiveness, and quality of life parame ters of these two drugs.

Epidermal growth factor receptor (EGFR) is not related to the prognosis of cervical cancer

We analyzed the prognostic significance of epidermal growth factor receptor (EGFR) in a large prospective series of 90 cervical cancer patients observed for a long follow-up period. EGFR levels ranged from 0 to 52.1 fmol/mg protein, with a median value of 6.0 fmol/mg protein. Patients with an advanced stage of disease expressed lower EGFR levels than those with an early stage of disease (median values were 7.8 fmol/mg protein for patients with stage I-II and 4.2 fmol/mg protein for patients with stage III-IV, P = 0.013). There was no correlation between EGFR expression and other clinicopathological parameters analyzed. No significant relationship was shown between EGFR positivity and overall survival. No significant relationship between EGFR status and disease-free survival was observed. Cox univariate regression analysis using EGFR as a continuous variable showed that EGFR levels are not associated with the risk of disease recurrence after treatment or death (P-value not significant). Our data didn't seem to indicate a prognostic role of EGFR in cervical cancer.

Oncogene expression is modulated by recombinant human interferon-beta in human breast-cancer cells

The effect of recombinant human interferon-beta on growth and oncoprotein expression was investigated in several human breast-cancer cell lines with different characteristics. All cell lines tested were sensitive to the antiproliferative action of the drug, regardless of their estrogen sensitivity. The maximal inhibition of cell proliferation was seen after 6 days of treatment. In estrogen-sensitive CG-5 and ZR-75-1 cells, but not in MDA-MB-453 estrogen-insensitive cells, a reduction in c-myc and c-erbB2 oncoproteins occurred after 48-72 hr and became more pronounced after 120-168 hr of treatment, suggesting that this down-regulation is not direct but is mediated by undefined molecular mechanisms. The time-course of the IFN-mediated decrease in oncoproteins seems to indicate that this event is not strictly related to the IFN-regulation of cell proliferation. The expression of c-erbB2 and c-myc was also analyzed, after recombinant human interferon-beta treatment, at the mRNA level in CG-5 cells. Surprisingly, no statistically significant variation of c-erbB2 or of c-myc mRNA was found either before or after 120-168 hr. Thus, we surmise that the observed reduction of oncoproteins may be due to post-transcriptional mechanisms.

Cytokine modulation of epidermal growth factor receptor expression on bladder cancer cells is not a major contributor to the antitumour activity of cytokines

Epidermal growth factor is a potential mitogen for many different human tumours. Its effect is mediated via a bispecific receptor (EGFR), the expression of which correlates well with invasive disease. We investigated the modulation of EGFR by cytokines produced following bacillus Calmette Guerin (BCG)-immunotherapy. Our data demonstrate the IFN gamma, TNF alpha and IL-1 alpha can decrease the expression of EGFR on some bladder tumour cell lines. IFN gamma reduced EGFR expression on two of eight cell lines (RT4, SD). However, IL-1 and TNF did not share this activity. When cells were treated with a combination of all three cytokines, EGFR was decreased on three cell lines (RT4, RT112, SD) and furthermore, the change in the receptor expression was even more marked. Treatment with phorbol ester (thereby activating protein kinase C) resulted in rapid disappearance of the receptor from the cell surface. Interestingly, the decrease of EGFR expression did not require protein synthesis. Although the cytokines studied could down modulate EGFR, this only occurred on three out of eight cell lines; therefore, it is unlikely that the suppression of proliferative activity caused by cytokine-induced decrease of EGFR expression is central to the antitumour action of BCG therapy, but in a proportion of tumours this mechanism may be involved.

Epidermal growth factor-induced protection of tumour cell susceptibility to cytolysis

Using radiobinding, transfection and colorimetric assays, the biological significance of epidermal growth factor (EGF) and its receptor on established human tumour cell lines was investigated. The intensity of class I major histocompatibility antigen (MHC) and EGF receptor (EGFR) expression on 20 tumour cell lines was investigated and showed no direct correlation (coefficient of correlation r = 0.43 and P = 0.06). furthermore, transfection of the beta 2-microglobulin gene into a class I negative bladder tumour cell line, resulting in the re-expression of fully assembled cell surface class I antigens, did not result in alteration of EGFR expression. However, there was an inverse correlation between the intensity of EGFR expression and the stimulatory response of cells to exogenously added EGF. The per cent inhibitions of cell proliferation by EGF at 100 ng/ml for A431 (highest EGFR expressor) and Scaber (lowest EGFR expressor) were 37 and -7%, respectively. The results also showed that cell lines isolated from testis tumours positive for epithelial markers (using pan keratin antibody LP34 as an epithelial marker), expressed significantly lower EGFR levels than cell lines from bladder tumours. The expression of EGFR receptor was not modulated by interferons (IFN-alpha and -gamma and only a minor effect with IFN-beta) or active supernatant containing a mixture of cytokines. Whilst the pretreatment of tumour cells with IFNs resulted in a significant increase in the susceptibility of tumour cells to interleukin-2-activated peripheral blood mononuclear cells, EGF treatment resulted in their protection. Thus, the per cent killing at an effector:target ratio of 20:1 for untreated cells and EGF (100 ng/ml), IFN-alpha (1000 U/ml), -beta (2000 U/ml) and -gamma (100 U/ml) were 53%, 33% (P = 0.004), 64% (P = 0.004), 69% (P = 0.001) and 66% (P = 0.001), respectively. These results indicate the complex interactions between EGF and EGFR and their relevance in modifying tumour cell behaviour. The hypothesis that the resistance to cytolysis of tumour cells induced by EGF stimulation may be a factor in the accelerated tumour growth seen in patients after traumatic tissue damage is discussed.

Effect of recombinant human interferon-alpha/2b on epidermal-growth-factor-, estrogen- and progesterone-receptor expression in primary cervical cancer

The effects of a short period of in vivo systemic rh-IFN-alpha/2b treatment on epidermal-growth-factor(EGFR)-, estrogen(ER)- and progesterone(PR)-receptor content in 11 primary human cervical tumors was investigated by the radioreceptorial technique. EGFR levels were found to be significantly higher in cervical tumors after rh-IFN-alpha/2b treatment with respect to basal levels. In 2 cases, immunohistochemical and cytofluorimetric analysis showed that rh-IFN-alpha/2b treatment induces an increase in EGFR immunoreactivity and in the fraction of EGFR-positive cells. No difference in ER and PR levels in cervical tumors before and after rh-IFN-alpha/2b treatment was observed. Our results suggest that rh-IFN-alpha/2b up-regulates EGFR in primary human cervical tumors in vivo.

Significance of epidermal growth factor receptor expression in primary human endometrial cancer

Radioreceptorial assessment of EGFR expression was prospectively performed on 60 primary human endometrial tumors. Of these, 26 were EGFR-positive while 13 expressed high EGFR levels. High EGFR levels correlated well with poor histopathological grading. No correlation with histopathological type, stage, myometrial invasion, lymph-node involvement or steroid hormone receptor status was observed. Disease-free survival rate was significantly shorter in the cases with high than in the cases with low EGFR levels. These results suggest a potential role of EGFR expression assessment in prognostic characterization of endometrial cancer patients.

Enhancement of progesterone receptor levels by interferons in AE-7 endometrial cancer cells

BACKGROUND

Interferon (IFN) has been reported to increase hormone receptor expression in breast cancer cells and to sensitize them to antiproliferative hormones. Endometrial cancer cells with high progesterone receptor (PR) level respond better to progesterone therapy than cells with either low or absent PR level. The effect of four different interferons (alpha and beta, both natural [n] and recombinant [r]) on cell proliferation and steroid receptor levels was investigated in the PR positive AE-7 human endometrial cancer cell line over a period of 12 days.

METHODS

Cells were exposed to 10,100 and 1000 IU/ml of each IFN either for 3 days or continuously for 12 days. Hormone receptors were determined by the monoclonal enzyme immunoassay. Chemosensitivity was evaluated with the adenosine triphosphate-cell viability assay.

RESULTS

AE-7 has a low level of estrogen receptors, which was not significantly affected by IFN exposure. The four IFN showed significantly enhanced PR levels over 12 days in both the 3-day and continuous-exposure experiments. No significant difference of PR enhancement was observed between 3 days and continuous exposure to IFN. This increase of receptors did not appear to be dose related. IFN enhanced PR level to a maximum level of about two times control cells. IFN did not produce significant cytotoxicity. Antiproliferative activity was observed with nIFN beta and rIFN beta at 1000 IU/ml dose in continuous-exposure experiments, which showed survival values of 79% and 69% respectively, compared with control at day 12.

CONCLUSIONS

These preliminary data on PR expression modulation support other studies, which have shown that IFN modulate hormone receptor expression and, therefore, may play a role in the treatment of endometrial cancer.

The effect of interferon gamma on epidermal growth factor receptor expression in normal and malignant ovarian epithelial cells

OBJECTIVE

We examined the effect of interferon gamma on proliferation and epidermal growth factor receptor expression in ovarian cancer cell lines and normal ovarian epithelial cells.

STUDY DESIGN

The tritiated thymidine incorporation assay was used to assess the effect of interferon gamma on proliferation. Scatchard analysis of anti-epidermal growth factor receptor antibody binding, and Western blotting of immunoprecipitates was used to assess the effect of interferon gamma on epidermal growth factor receptor expression.

RESULTS

Although interferon gamma elicited 30% to 40% decreases in proliferation, epidermal growth factor receptor expression was strikingly increased in all four ovarian cancer cell lines. Scatchard analysis indicated that this increase occurred primarily at the cell surface, but total cellular receptor levels also were increased. In contrast, interferon gamma treatment of normal ovarian epithelial cells affected neither proliferation nor epidermal growth factor receptor levels.

CONCLUSION

Because the up-regulation of epidermal growth factor receptors by interferon gamma appears to be confined to malignant cells, interferon gamma may facilitate immunotherapy and imaging of ovarian cancers by means of immunoconjugates directed against the epidermal growth factor receptor.

The immune system and gynaecological cancer

There have been major advances in our understanding of the cellular and humoral immune mechanisms involved in antitumour activities. The characterization of soluble mediators of the immune response and their synthesis as recombinant proteins has led to an explosion of research activity concerning their role as antitumour agents and also as contributors to the pathogenesis of cancer. It is evident that cytokine production is not restricted to cells of the immune system, and that cytokines are involved in a variety of cell regulatory processes ranging from embryonic development to tissue differentiation. Their production by immune cells may enable interactions between the immune system and other homeostatic systems of the body. The therapeutic role of some cytokines such as the interferons and IL-2 in the routine management of gynaecological cancers needs to be investigated further because of their promise as antitumour agents. The study of cytokine production and cytokine receptor expression by cancers is potentially of great therapeutic value. Identification of cytokines that contribute to tumour progression may paradoxically lead to the treatment of cancers by agents that antagonize their biological effects and to rationalization of future trials of cytokine therapy.