Apoptosis of human carcinoma cells in the presence of potential anti-cancer drugs: III. Treatment of Colo-205 and SKBR3 cells with: cis-platin, Tamoxifen, Melphalan, Betulinic acid, L-PDMP, L-PPMP, and GD3 ganglioside

Abstract

Breast cancer is the most common type of cancer, predominantly among women over 20, whereas colo-rectal cancer occurs in both men and women over the age of 50. Chemotherapy of both cancers affect rapidly growing normal as well as cancer cells. Cancer cells are non-apoptotic. Seven anti-cancer agents (cis -platin, Tamoxifen, Melphalan, Betulinic acid, D-PDMP, L-PPMP, and GD3) have been tested with human breast (SKBR3) and colon (Colo-205) carcinoma cells for their apoptotic effect and found to be positive by several assay systems. Colo-205 cells were obtained from ATCC, and the SKBR3 cells were a gift from the Cleveland Clinic. All of these six agents killed those two cell lines in a dose-dependent manner. In the early apoptotic stage (6 h), these cells showed only a flopping of phosphatidylserine on the outer lamella of the plasma membranes as evidenced by the binding of a novel fluorescent dye PSS-380. After 24 h of the treatment, those apoptotic cells showed damage of the plasma as well as the nuclear membrane as evidenced by binding of propidium iodide to the nuclear DNA. DNA laddering assay viewed further breakdown of DNA by 1% agarose gel electrophoresis analysis. It is concluded that during apoptosis the signaling by Mitochondrial Signaling Pathway (MSP) is stimulated by some of these agents. Caspase 3 was activated with the concomitant appearance of its p17 polypeptide as viewed by Westernblot analyses. Incorporation of radioactivity from [U-(14)C]-L-serine in total sphingolipid mixture was observed between 2 and 4 micromolar concentrations of most of the agents except ci s-platin. However, apoptosis in carcinoma cells in the presence of cis -platin is induced by a caspase 3 activation pathway without any increase in synthesis of ceramide.

LAGλ-1: A clinically relevant drug resistant human multiple myeloma tumor murine model that enables rapid evaluation of treatments for multiple myeloma

“…LAGÏ-1 tumors proved to be resistant to this alkylating agent with only minimal anti-tumor effects observed among animals that received the highest dose of the drug. This dose (12.0 mg/ kg) was much higher than doses of melphalan that produced anti-myeloma effects in SCID mice bearing the RPMI-8226 cell line as well as mice growing other MM cell lines (27)(28)(29). Hence, the LAGÏ-1 tumors retained the melphalan resistance of the MM patient's cancer cells showing that although this human myeloma has been maintained through serial passages in SCID mice, the characteristics of the patient's original tumor's drug resistance were unaltered.…”

c-Jun activation is required for 4-hydroxytamoxifen-induced cell death in breast cancer cells

“…We used the ER-negative breast cancerderived cell line SkBr3 as a model system to analyse the role of JNK-activated c-Jun in the OHT-dependent apoptosis. First, we examined whether micromolar concentrations of OHT, which were earlier reported to be cytotoxic in SkBr3 cells (Basu et al, 2004), could induce hallmarks of apoptotic cell death such as DNA fragmentation and caspase 3/7 activation. As shown by flow cytometric analysis, DNA fragmentation was induced by 10 mM OHT and was further increased by 25 mM OHT, whereas neither concentration had any influence on cell cycle phases (Figures 1a and b).…”

Melphalan inhibits adenoma development through modulating the expression of K-ras-specific markers in K-ras Tg mice

“…Activating mutation in the K-ras oncogenes may accelerate more progression of adenomas and malignant tumors by various genotoxic carcinogens in transgenic mouse models and tumors (25,27). However, anti-cancer or DNA-damaging agents or genotoxic carcinogens such as melphalan induce apoptosis in carcinoma cells (28,29). It is necessary to monitor the modulating effects of melphalan treatment on K-ras Tg mice in order to prove K-ras-modulated biomarkers identified by a previous study (9).…”