Modulation of BCRP mediated atypical multidrug resistance phenotype by RNA interference

Multidrug resistance (MDR) in human cancers is one of the major causes of failure of chemotherapy. The emergence of breast cancer resistance protein (BCRP), a member of the ABC transporter family, has necessitated the development of antagonists. To overcome the BCRP-mediated atypical multidrug drug resistance, two small interfering RNA constructs (RNAi) targeting two different regions of BCRP mRNA were designed to inhibit the atypical MDR expression by transfecting them into MCF-7/MX100 cell lines. The multidrug resistance index to mitoxantrone and the intensity of mitoxantrone fluorescence of MCF-7/MX100 decreased after transfected by pSUPER-BCRP-A and pSUPER-BCRP-B respectively; the BCRP mRNA level and the BCRP protein level of MCF-7/MX100 decreased after treated with pSUPER-BCRPs. The two constructed RNAi plasmids could reverse the atypical mutidrug resistance mediated by BCRP, but neither can reversed it completely, this may be due to low transfection efficiency and transient transfection.

Evaluation of bone mineral density of the lumbar spine and proximal femur in population-based routine health examinations of healthy Asians

PURPOSE

To understand the peak bone mineral density (BMD) and annual loss of BMD of the lumbar spine (L-BMD) and the proximal femur (F-BMD) and the prevalence of osteoporosis in both sexes in Taipei City, Taiwan.

MATERIAL AND METHODS

The medical records from a recent 3-year period of annual health examinations at a single institution were reviewed. A total of 1514 men (mean age 49.08 +/- 13.62) and 1955 women (48.07 +/- 14.12), who lived in the Taipei area, had no major systemic disorders, and who had undergone both L-BMD and F-BMD examinations, were recruited.

RESULTS

In women, peak L-BMD (1.078 +/- 0.133 g/cm2) occurred in the 30 to 39-year age group, whereas peak F-BMD (0.873 +/- 0.101 g/cm2) occurred in the 17 to 29-year age group. In men, peak L-BMD (1.095 +/- 0.137 g/cm2) and F-BMD (0.989 +/- 0.140 g/cm2) both occurred in the 17 to 29-year age group. The estimated annual bone loss was 0.69% of peak L-BMD in women over 50 years; in the proximal femur this was 0.688% in women and 0.332% in men. In women over 60 years, approximately half of the population had osteoporosis in the lumbar spine.

CONCLUSION

We report descriptive BMD data of a Chinese population recruited from a Taipei urban area who underwent routine health examination. The values are similar to or higher than those of Japanese, Canadian and Greek populations. L-BMD was lower than that in the Lebanese, and F-BMD of both sexes was lower than that reported in the Greek study.