Novel cancer cell lines derived from primary breast tumors in Chinese patients

Abstract

Although many breast cancer cell lines have been used for cancer research during the past several decades, few have originated from primary tumors in Asian patients. Moreover, the incidence of breast cancer has been increasing rapidly in China during this time period. Therefore, it is essential to establish breast cancer cell lines from Chinese patients. Here, we report the establishment of three new breast cancer cell lines, designated BC-023, BC-024, and BC-034, from breast carcinoma tissues of three Chinese patients. These breast cancer cell lines grew as adherent monolayers with characteristic epithelial morphology and were maintained continuously in vitro with stable growth rates for at least 20 passages. No bacterial, fungal, or mycoplasma contamination was detected in any of the three cell lines. Additionally, these cells were human epidermal growth factor receptor 2 (C-erbB-2)-positive. All three cell lines had comparable population doubling times of 33-39 h and reproducibly formed colonies in soft agar. Furthermore, these cells displayed aggressive tumorigenicity. Thus, every characteristic of each of these cell lines meets the quality control standards of the American Type Culture Collection (ATCC). We used drug sensitivity testing with growth-inhibition assays and showed that these three lines expressed a wide range of sensitivities to cisplatin (DDP) and adriamycin (ADR). These studies indicate that these three novel cell lines may provide new models for studying cancer biology and for screening new drugs for breast cancer treatment, especially for the Chinese population.

Keywords: Breast cancer; cell lines; drug sensitivity.

Figure 1

Morphology of the three breast cancer cell lines. A: BC-023 cell line at passage 22 (× 100); B: BC-024 cell line at passage 34 (× 100); C: BC-034 cell line at passage 27 (× 100).

Figure 2

Growth curves of the three breast cancer cell lines. The cells were seeded at 2 × 10³ cells per well, and growth was measured by MTT every 24 h for 7 d.

Figure 3

Mycoplasma analysis in breast cancer cell line cultures. A: Mycoplasma colonies were observed as fried-egg morphology in the positive control culture. B: Hoechst 33258 staining of cell line cultures. Mycoplasma contamination was observed as small extracellular fluorescent particles (red arrows indicate the positive control).

Figure 4

Isoenzymology analysis of lactate dehydrogenase (LD) and glucose-6-phosphate dehydrogenase (G6PD) in the three breast cancer cell lines. L929 is the mouse control, and HeLa is the human control.

Figure 5

Immunocytochemical analysis of the three breast cancer cell lines. The expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (C-erbB-2) were detected using the SuperRmEPC™ Breast Cancer Detection Kit.

Figure 6

Anchorage-independent growth capacity analysis. A: Representative images for each cell line after 14 d of growth. B: Colony formation assays. Cells were seeded at 2 × 10³ cells per well in 6-well culture plates. Values in B represent means ± SEM for triplicate wells.

Figure 7

Tumorigenicity test of breast cancer cells in nude mice. Red arrows indicate the tumors in the nude mice. Nude mouse 30 d post-injection with (A) MRC-5 cells (negative control), (B) MCF-7 cells (positive control), (C) BC-023 cells, (D) BC-024 cells (note the bilateral tumors), and (E) BC-034 cells.

Figure 8

Drug sensitivity assays. Drug sensitivity curves show cell viability of BC-023, BC-024, BC-034, and MCF-7 cells treated with the indicated concentrations of cisplatin (DDP; A) or adriamycin (ADR; B). For all comparisons, P<0.005.