Citations

AbstractA lipid‐conjugated, estrogenic derivative molecule, ESC8, compared with other estrogenic molecules, encourages cell death in both ER‐positive and ER‐negative breast cancer cells. A rapid and highly sensitive assay method has been developed and validated for the estimation of a ESC8 in rat plasma using liquid chromatography coupled with mass spectrometry under positive‐ion mode with electrospray ionization. The sample process includes using methanol for precipitation of ESC8 and dextromethorphan (internal standard, IS) from plasma. Chromatographic separation was achieved with methanol–water–formic acid (70:30:0.1% v/v/v) pumped at a flow rate of 0.3mL/min and a C18 column (50 × 2.1 mm i.d., 1.7 μm particle size) with a total run time of 5 min. The m/z ions monitored were 568.5 and 272.1 for ESC8 and IS, respectively. The lower limit of quantitation achieved was 1.08 ng/mL and linearity was observed from 5 to 500 ng/mL. The intra‐ and inter‐day precisions were <4%. The proposed method was successfully applied to a preliminary pharmacokinetic study of ESC8 liposomal formulation following an intraperitoneal administration of 3.67 mg/kg in rats. The concentrations of ESC8 in plasma were quantifiable up to 36 h. The peak concentration of ESC8 was found to be 110.72 ng/mL, the area under the concentration–time curve was 1625.23ng/mL h and the half‐life was 11.72 h.

Abstract Tumor metastasis refers to spread of a tumor from site of its origin to distant organs and causes majority of cancer deaths. Although &gt;30 metastasis suppressor genes (MSGs) that negatively regulate metastasis have been identified so far, two issues are poorly understood: first, which MSGs oppose metastasis in a tumor type, and second, which molecular function of MSG controls metastasis. Herein, integrative analyses of tumor-transcriptomes (n = 382), survival data (n = 530) and lymph node metastases (n = 100) in lung cancer patients identified non-metastatic 2 (NME2) as a key MSG from a pool of &gt;30 metastasis suppressors. Subsequently, we generated a promoter-wide binding map for NME2 using chromatin immunoprecipitation with promoter microarrays (ChIP-chip), and transcriptome profiling. We discovered novel targets of NME2 which are involved in focal adhesion signaling. Importantly, we detected binding of NME2 in promoter of focal adhesion factor, vinculin. Reduced expression of NME2 led to enhanced transcription of vinculin. In comparison, NME1, a close homolog of NME2, did not bind to vinculin promoter nor regulate its expression. In line, enhanced metastasis of NME2-depleted lung cancer cells was found in zebrafish and nude mice tumor models. The metastatic potential of NME2-depleted cells was remarkably diminished upon selective RNA-i-mediated silencing of vinculin. Together, we demonstrate that reduced NME2 levels lead to transcriptional de-repression of vinculin and regulate lung cancer metastasis.

Abstract It is a challenge to develop a universal single drug that can treat breast cancer at single- or multiple-stage complications, yet remains nontoxic to normal cells. The challenge is even greater when breast cancer–specific, estrogen-based drugs are being developed that cannot act against multistaged breast cancer complications owing to the cells differential estrogen receptor (ER) expression status and their possession of drug-resistant and metastatic phenotypes. We report here the development of a first cationic lipid-conjugated estrogenic derivative (ESC8) that kills breast cancer cells independent of their ER expression status. This ESC8 molecule apparently is nontoxic to normal breast epithelial cells, as well as to other noncancer cells. ESC8 induces apoptosis through an intrinsic pathway in ER-negative MDA-MB-231 cells. In addition, ESC8 treatment induces autophagy in these cells by interfering with the mTOR activity. This is the first example of an estrogen structure–based molecule that coinduces apoptosis and autophagy in breast cancer cells. Further in vivo study confirms the role of this molecule in tumor regression. Together, our results open new perspective of breast cancer chemotherapy through a single agent, which could provide the therapeutic benefit across all stages of breast cancer. Mol Cancer Res; 9(3); 364–74. ©2011 AACR.