In vitro effects and clinical evaluation of a human chorionic gonadotrophin preparation in acute leukemia

Evaluation of a novel immunomodulator composed of human chorionic gonadotropin and bacillus Calmette-Guerin for treatment of canine mast cell tumors in clinically affected dogs

OBJECTIVE

To evaluate safety and efficacy of LDI-100, a preparation containing human chorionic gonadotropin (hCG) and bacillus Calmette-Guerin (BCG), in the treatment of dogs with mast cell tumors and to compare results with those from a control group receiving single-agent vinblastine.

ANIMALS

95 dogs with measurable grade II or III mast cell tumors.

PROCEDURES

Dogs were randomized to receive either LDI-100 (1.35 ng of BCG and 2 units of hCG, SC, q 24 h) or vinblastine (2 mg/m(2), IV, q 1 wk) for 6 weeks. Tumors were measured at baseline and day 42, and dogs were monitored for signs of toxicosis. Clinical performance scores were recorded at each visit. Differences in host factors (sex, weight, and age), clinical performance score, tumor response, and adverse events were analyzed.

RESULTS

46 dogs received LDI-100, and 49 dogs received vinblastine. No significant differences were found between the 2 treatment groups with regard to host factors or clinical performance score. Tumor response (>or=50% reduction) rates were similar between the LDI-100 and vinblastine group (28.6% and 11.7%, respectively). Dogs in the LDI-100 group had significantly less neutropenia than the vinblastine group.

CONCLUSIONS AND CLINICAL RELEVANCE

hCG and BCG have immunomodulatory and antitumor effects against a variety of malignancies in humans and dogs. In this study, LDI-100 provided clinical responses comparable to single-agent vinblastine chemotherapy but without myelosuppression. LDI-100 is a promising new agent that should be further investigated for multimodality therapy of mast cell tumors in dogs.

Using flow cytometry to follow the apoptotic cascade

Flow cytometry has been extensively used to follow the apoptotic cascade and to enumerate apoptotic cells, both in cell cultures and, to a lesser extent, in tissue biopsies. An overview of the apoptotic cascade and how flow cytometric measurements can be used to observe the different elements of this process is presented.

Enhancement of radiosensitivity of the MCF-7 breast cancer cell line with human chorionic gonadotropin

Secretion of human chorionic gonadotropin (hCG) during pregnancy induces differentiation of the mammary gland, thereby making breast tissue less susceptible to carcinogenesis. HCG binds to specific hCG receptors on mammary epithelial cells inducing changes in gene expression that can inhibit cell proliferation and, therefore, interfere with tumorigenesis. Since breast cancer cells also contain a relatively high level of the hCG receptor, hCG has potential as a therapeutic agent. We postulated that hCG might also enhance the radiosensitivity of breast cancer cells and, therefore, be useful as an adjunctive therapy. In the present study, MCF-7 breast cancer cells grown in cell culture were treated with hCG (0.2-5 IU/ml) for 24 h prior to exposing the cells to 0 Gy, 3 Gy, 4 Gy, or 5 Gy of radiation. Following irradiation, the MCF-7 cells were incubated either in the presence or absence of hCG. Cell survival was monitored with an MTT assay 1 day, 4 days, and 7 days after irradiation. All of the concentrations of hCG tested enhanced radiosensitivity of MCF-7 cells. The maximum enhancement occurred with MCF-7 cells that had been exposed to 2 IU/ml of hCG for at least 24 h prior to irradiation with 4 Gy. The use of higher concentrations of hCG or a higher dose of radiation did not increase the enhancement effect. Treatment of MCF-7 cells with hCG for only 24 h was sufficient to achieve the maximum effect. However, maintaining the cells in hCG beyond 24 h increased the effectiveness of the lowest hCG concentration. Using a linear-quadratic equation to analyze the data, we determined that the use of hCG would result in an 8-10% reduction in MCF-7 cell survival at a dose of 2 Gy, a typical dose used in conventional cancer therapy.