Detection of recombinant P-glycoprotein in multidrug resistant cultured cells

Improved survival in patients with peritoneal metastases from colorectal cancer: a preliminary study

Patients with peritoneal or local metastases from colorectal cancer have a poor prognosis. However, aggressive treatments by debulking surgery and infusional intraperitoneal (i.p.) chemotherapy have been tried and appear to benefit selected patients. We assayed the effects of debulking surgery and i.p. chemotherapy with respect to survival and compared the results with matched control patients treated by intravenous (i.v.) chemotherapy. In all, 18 patients with peritoneal and/or local metastases from colorectal adenocarcinoma underwent debulking surgery followed by 5-fluorouracil (5-FU) 550 mg m⁻² day⁻¹ i.p. and leucovorin (LV) 60 mg m⁻² day⁻¹ i.v. The chemotherapy was started the day after surgery and was given daily for 6 days and repeated monthly for totally eight courses. The control patients, matched for age, gender, performance status and metastatic site, were randomly selected from controlled clinical chemotherapy trials and treated with i.v. 5-FU+LV or i.v. methotrexate+5-FU+LV. There was no treatment-related mortality. The median survival among i.p. patients was 32 months compared to 14 months in the control group. In all, 11 patients who underwent macroscopically radical surgery had a longer survival than those who were not radically operated (P=0.02). These results indicate that patients with peritoneal metastases and/or locally advanced cancers but without distant metastases may benefit from cytoreductive surgery combined with i.p. chemotherapy.

Cyclosporin A Aerosol Improves the Anticancer Effect of Paclitaxel Aerosol in Mice

The objective of this study was to assess the effect of cyclosporin A liposome aerosol on the anticancer activity of paclitaxel (PTX) liposome aerosol against renal cell carcinoma (Renca) pulmonary metastases in mice. Cyclosporin A (CsA) was administered as a liposome aerosol for one-half hour before starting one-half hour treatment with PTX liposome aerosol (CsA/PTX), and in a second groups of animals cyclosporin A liposome aerosol was given before PTX for one-half hour and also later by mixing a second dose of cyclosporin A aerosol with PTX aerosol and extending the treatment period to one hour (CsA/PTX + CsA). In one experiment, PTX and CsA/PTX aerosols were significantly more effective compared to untreated controls against renal cell cancer as measured by lung weights and tumor surface areas. CsA/PTX was significantly better that PTX alone as measured by lung weights and tumor area. In a second experiment, tumor areas of PTX and CsA/PTX treated mice were significantly reduced compared to untreated controls and CsA/PTX treated mice had significantly smaller tumor areas than PTX treated mice. In contrast, tumor numbers were not significantly fewer than controls in either therapeutic group. In a third experiment, tumor numbers and tumor areas were significantly fewer in mice treated with CsA/PTX and CsA/PTX + CsA compared to untreated controls. Mice treated with CsA/PTX + CsA had significantly fewer tumors and less tumor area than mice receiving CsA/PTX. While PTX treated mice were not different than untreated controls with respect to tumor numbers or tumor volumes, PTX treated mice had significantly greater tumor numbers and tumor areas than CsA/PTX and CsA/PTX + CsA treated mice. Co-administration of CsA with PTX demonstrated significant dose dependent anticancer effects against renal cell pulmonary metastases in mice. Toxicity manifested by weight loss was associated with the highest dose of CsA.

MDR1 gene expression in endometrial carcinoma

The objective of the present study was to determine the MDR1 gene expression in endometrial cancer. Twenty-six newly diagnosed patients with endometrial carcinoma were included in this study. Patients were treated with surgery followed by adjuvant radiotherapy. Four- to six-micrometer sections of the archival paraffin-embedded blocks were cut, deparaffinized, and stained by immunohistochemical technique using P-glycoprotein dye. Endothelial cell staining was used as the positive control of the dye. Immunostaining was categorized from 0% to 100% based on the percentage of cells stained by examining 3-4 high-power fields. The mean P-glycoprotein immunoreactivity for the whole study group was 17 +/- 25% (0-90). Tauhe mean P-glycoprotein immunoreactivity was 21 +/- 26% (0-90) for the endometrioid histology and 6 +/- 13% (0-30) for the clear cell histology. P-glycoprotein immunoreactivity was not detected in a case of mucinous histologic subtype. There was a significant negative correlation between age and P-glycoprotein immunoreactivity (r = -0.530, P = 0.005). The P-glycoprotein immunoreactivity was found to be 30% positive in only one case of clear cell histologic type out of five. However, P-glycoprotein immunoreactivity was not significantly lower in clear cell histologic subtype compared with endometrioid subtype of endometrial cancer (P = 0.116). P-glycoprotein immunoreactivity was found to be 0% in grade 1 (n = 2), 22 +/- 28% in grade 2 (n = 17), and 8 +/- 14% in grade 3 (n = 7) patients (P = 0.273). Premenopausal patients were found to have a significantly higher P-glycoprotein expression (40 +/- 33)% vs. 11 +/- 20%, P = 0.04). P-glycoprotein immunoreactivity was found to be less with advanced age in endometrial carcinoma. However, premenopausal patients were found to have a significantly higher P-glycoprotein expression.