Disruption of ETV6 leads to TWIST1-dependent progression and resistance to epidermal growth factor receptor tyrosine kinase inhibitors in prostate cancer.

BACKGROUND: ETS variant gene 6 (ETV6) is a putative tumor suppressor and repressed by epidermal growth factor receptor (EGFR) signaling in prostate cancer. Since EGFR antagonists seem ineffective in castration-resistant prostate cancer (CRPC), we aim to study the role of ETV6 in the development of drug resistance. METHODS: Etv6 target gene was validated by ChIP and promoter reporter assays. Correlation of ETV6 and TWIST1 was analyzed in human clinical datasets and tissue samples. Migration, invasion, and metastasis assays were used to measure the cellular responses after perturbation of ETV6 -TWIST1 axis. Proliferation and tumor growth in xenograft model were performed to evaluate the drug sensitivities of EGFR-tyrosine kinase inhibitors (TKIs). RESULTS: ETV6 inhibits TWIST1 expression and disruption of ETV6 promotes TWIST1-dependent malignant phenotypes. Importantly, ETV6 is required to the anti-proliferation effects of EGFR-TKIs, partly due to the inhibitory function of ETV6 on TWIST1. We also found that EGFR-RAS signaling is tightly controlled by ETV6, supporting its role in TKI sensitivity. CONCLUSIONS: Our study demonstrates that disruption of ETV6 contributes to EGFR-TKI resistance, which is likely due to derepression of TWIST1 and activation of EGFR-RAS signaling. Our results implicate ETV6 as a potential marker for predicting efficacy of an EGFR-targeted anticancer approach. Combination treatment of TWIST1 inhibitors could sensitize the anti-proliferation effects of EGFR-TKIs.

Androgen deprivation therapy-induced epithelial-mesenchymal transition of prostate cancer through downregulating SPDEF and activating CCL2.

The chemokine CC motif ligand 2 (CCL2) is important in recruiting tumor-associated macrophages and is involved in the development of castration-resistance prostate cancer (CRPC) after androgen-deprivation therapy (ADT); however, the underlying mechanism remains unclear. We found that inactivation of the androgen receptor (AR) reduces a transcriptional repressor (SAM pointed domain-containing ETS transcription factor, SPDEF) of CCL2, which mediates epithelial-to-mesenchymal transition (EMT) of prostate tumor cells. Cell lines derived from a prostate-specific Pten/Trp53-null mouse and capable of a spontaneous EMT were utilized for identification of CCL2, and showed that reduced SPDEF expression was associated with an elevated CCL2-activated EMT. AR signaling inhibits CCL2 through a SPDEF-mediated mechanism in that the SPDEF recognizes the CCL2 promoter and transcriptionally represses its activity. Ectopically expressed SPDEF reduced the EMT and rescued expression of CCL2 in SPDEF-expressing cells, which induced the EMT and promotes malignant functions of prostate cancer cells. In tissues from prostate cancer patients with ADT, low SPDEF levels were correlated with high CCL2 expression compared to patients without ADT. We present a novel mechanism that contributes to the EMT and metastatic phenotype observed in a subset of ADT-resistant prostate cancer, where the CCL2 is stimulated through the inactivated of AR-mediated SPDEF.

[Spectral Study on the Effects of Angle-Tuned Filter Wedge Angle Parameter to Reflecting Characteristics].

Three-port tunable optical filter is a key device in the all-optic intelligent switching network and dense wavelength division multiplexing system. The characteristics of the reflecting spectrum, especially the reflectivity and the isolation degree are very important to the three-port filter. Angle-tuned thin film filter is widely used as a three-port tunable filter for its high rectangular degree and good temperature stability. The characteristics of the reflecting spectrum are greatly influenced not only by the incident angle, but also by the wedge angle parameter of the non-paralleled wedge thin film filter. In the present paper, the influences of the wedge angle parameter to the reflectivity and the half bandwidth are analyzed, and the reflecting spectrum characterstics are simulationed in different wedge angle parameter and polarity. The wedge angle-tuned thin film filter with 0.8° wedge angle parameter is fabricated. The experimental results show that keeping the wedge angle the same orientation to the incident angle will worsen the reflectivity and the rectangular degree of the reflecting spectrum. However, keeping the wedge angle orientation reverse to the incident angle will enhance the reflectivity and decrease the bandwidth, which will give higher reflectivity and isolation degree to the three-port filter than that of high parallel degree angle-tuned thin film filter.

[Research on the transmittance spectrum of wedge thin film filter with oblique incidence].

Angle-tuned thin film filter is widely used in the DWDM system for its broad tunable wavelength range and high rectangular degree. The transmissivity and the half bandwidth is greatly influenced not only by the incident angle, but also by the wedge angle of the non-paralleled thin film filter. In the present paper, the influences of the wedge angle on the transmissivity and the half bandwidth were detailedly analyzed. The proper wedge angle and the orientation can greatly improve the characteristics of the transmittance spectrum. The angle-tuned thin film filter with 0.8 degrees wedge angle was also fabricated. The experimental results show that keeping the wedge angle with the same orientation to the incident angle will worsen the transmissivity and the rectangular degree of the transmittance spectrum. However, keeping the wedge angle orientation reverse to the incident angle will greatly enhance the transmissivity and the rectangular degree of the filter and its tunable wavelength range will broaden by 10 nm.

[Effect of Chinese herbal medicine with Supplement Qi and Activating Blood Circulation on tubular reabsorption function of diabetic nephropathy rats].

OBJECTIVE: To investigate the effect of Chinese herbal medicine with Supplement Qi and Activating Blood Circulation (huangqi and danshen) on urinary protein, kidney function and tubular reabsorption of diabetic nephropathy rats. METHODS: SD rats were randomly divided into a nondiabetic control group (normal group) and three groups in which diabetes were induced by a single intraperitoneal injection of freshly prepared streptozotocin( STZ,55 mg/kg body weight). Then the diabetes rats were randomly assigned to three groups: diabetic model group, Supplement Qi and Activating Blood Circulation traditional Chinese medicine group (huangqi and danshen group) and Gliquidone group (as a reference hypoglycemic drug). Each group was treated with corresponding drugs for 6 weeks. At the end of the study, the rats from each group were injected with FITC-labeled BSA through tail vein. The 24 h urinary protein excretion were measured and blood was collected for measuring plasma glucose levels, serum creatinine (Cr), blood urea nitrogen (BUN), triglyceride (TG) and total cholesterol (T-CHO). Renal tissue was used to measure the level of LPO,SOD,GSH-Px and AGEs and Paraffin-embedded sections were stained with HE, PAS and immunohistochemistry. RESULTS: The plasma glucose, the 24 h urinary protein excretion, the levels of serum Cr, BUN, TG and T-CHO in STZ-induced diabetic rats were higher than those of nondiabetic rats. Diabetic rats showed significantly increase in LPO and AGEs (P < 0.01) and decrease in antioxidant enzyme activity (both GSH-Px and SOD) (P < 0.05) as compared with non-diabetic control rats. Treatment with the Supplement Qi and Activating Blood Circulation traditional Chinese medicine for 6 weeks in diabetic rats significantly reduced the 24 h urinary protein excretion compared with model control (P < 0.01), and markedly decreased the levels of serum Cr,BUN,TG and T-CHO as compared with those of diabetic rat (P < 0.05). The levels of LPO and AGEs were decreased and the activity of GSH-Px was increased by Supplement Qi and Activating Blood Circulation treatment. The kidney proximal tubule lesions were improved and the reabsorption of FITC-BSA in tubular was increased in diabetic rats treated by huangqi and danshen, and the expression of megalin in proximal tubular was enhanced as compared with diabetic rats. CONCLUSION: Diabetic nephropathy rats treated with traditional Chinese medicine therapeutic principles "Supplement Qi and Activating Blood Circulation" can reduce the 24 h urinary protein excretion and improve the function of tubular reabsorption. These protect effects may be in correlation with enhancement the renal tissue activity of antioxidant and up-regulation the expression of megalin in renal tubular epithelial cells in diabetic rats.

Prostate organoids: emerging experimental tools for translational research.

Organoid technology has provided new translational research opportunities in oncology, in part by enabling the development of patient-representative living biobanks. Prostate cancer research historically has been constrained to a small number of in vitro models, limiting the ability to translate experimental conclusions for contemporary, heterogeneous patient populations. The facility of organoid culture methods to maintain luminal prostate epithelia, the common lineage of prostate cancers, has greatly expanded the phenotypic and genotypic diversity of available tractable models, including luminal stem/progenitor cells and progressive patient-derived cancers. Biobanks of patient prostate cancer organoids enable increased accuracy in predicting therapeutic efficacy and informative clinical trial designs. Here, we discuss how prostate organoid technology is currently being used, the promising areas of future therapeutic applications, and the current obstacles to be overcome.

TDAG51 is an ERK signaling target that opposes ERK-mediated HME16C mammary epithelial cell transformation.

INTRODUCTION: Signaling downstream of Ras is mediated by three major pathways, Raf/ERK, phosphatidylinositol 3 kinase (PI3K), and Ral guanine nucleotide exchange factor (RalGEF). Ras signal transduction pathways play an important role in breast cancer progression, as evidenced by the frequent over-expression of the Ras-activating epidermal growth factor receptors EGFR and ErbB2. Here we investigated which signal transduction pathways downstream of Ras contribute to EGFR-dependent transformation of telomerase-immortalized mammary epithelial cells HME16C. Furthermore, we examined whether a highly transcriptionally regulated ERK pathway target, PHLDA1 (TDAG51), suggested to be a tumor suppressor in breast cancer and melanoma, might modulate the transformation process. METHODS: Cellular transformation of human mammary epithelial cells by downstream Ras signal transduction pathways was examined using anchorage-independent growth assays in the presence and absence of EGFR inhibition. TDAG51 protein expression was down-regulated by interfering small hairpin RNA (shRNA), and the effects on cell proliferation and death were examined in Ras pathway-transformed breast epithelial cells. RESULTS: Activation of both the ERK and PI3K signaling pathways was sufficient to induce cellular transformation, which was accompanied by up-regulation of EGFR ligands, suggesting autocrine EGFR stimulation during the transformation process. Only activation of the ERK pathway was sufficient to transform cells in the presence of EGFR inhibition and was sufficient for tumorigenesis in xenografts. Up-regulation of the PHLDA1 gene product, TDAG51, was found to correlate with persistent ERK activation and anchorage-independent growth in the absence or presence of EGFR inhibition. Knockdown of this putative breast cancer tumor-suppressor gene resulted in increased ERK pathway activation and enhanced matrix-detached cellular proliferation of Ras/Raf transformed cells. CONCLUSION: Our results suggest that multiple Ras signal transduction pathways contribute to mammary epithelial cell transformation, but that the ERK signaling pathway may be a crucial component downstream of EGFR activation during tumorigenesis. Furthermore, persistent activation of ERK signaling up-regulates TDAG51. This event serves as a negative regulator of both Erk activation as well as matrix-detached cellular proliferation and suggests that TDAG51 opposes ERK-mediated transformation in breast epithelial cells.

Correction: Loss of EGFR signaling-regulated miR-203 promotes prostate cancer bone metastasis and tyrosine kinase inhibitors resistance.

[This corrects the article DOI: 10.18632/oncotarget.1994.].

[Fluorescence properties of C60-glucocorticoids].

C60 and its derivatives have become a research hotspot because of their unique structures, physical and chemical properties. The fluorescence properties of C60 and its derivatives are an important research embranchment of the fullerene science field. In the present paper the fluorescence properties of C60-glucocorticoids were firstly investigated. When excited with the wavelength of 350 nm at room temperature, C60-glucocorticoids displayed the fluorescence emission in chloroform at 447 nm. The sixty carbon atoms of C60 molecule are equivalent, belonging to the Ih group, and presenting high symmetry. It is difficult to observe the fluorescence of C60 under the same condition because of the high symmetry of C60 molecule. The fluorescence emission of C60-glucocorticoids is probably due to the decrease in the high symmetry of C60 molecule. Moreover, the fluorescence emission at 447 nm of a series of concentrations (10-13 micromol x L(-1)) of C60-glucocorticoids chloroform solutions excited at 350 nm was determined, and the result indicated that the C60-glucocorticoids in chloroform could quench itself's fluorescence intensity. Within the concentration range of 10-64 micromol x L(-1), the fluorescence intensity increased along with the accretion of the concentration. When the concentration of C60-glucocorticoids was greater than 64 micromol x L(-1) the fluorescence intensity decreased gradually.

Epidermal growth factor receptor signaling promotes metastatic prostate cancer through microRNA-96-mediated downregulation of the tumor suppressor ETV6.

It has been suggested that ETV6 serves as a tumor suppressor; however, its molecular regulation and cellular functions remain unclear. We used prostate cancer as a model system and demonstrated a molecular mechanism in which ETV6 can be regulated by epidermal growth factor receptor (EGFR) signaling through microRNA-96 (miR-96)-mediated downregulation. In addition, EGFR acts as a transcriptional coactivator that binds to the promoter of primary miR-96 and transcriptionally regulates miR-96 levels. We analyzed two sets of clinical prostate cancer samples, confirmed association patterns that were consistent with the EGFR-miR-96-ETV6 signaling model and demonstrated that the reduced ETV6 levels were associated with malignant prostate cancer. Based on results derived from multiple approaches, we identified the biological functions of ETV6 as a tumor suppressor that inhibits proliferation and metastasis in prostate cancer. We present a molecular mechanism in which EGFR activation leads to the induction of miR-96 expression and suppression of ETV6, which contributes to prostate cancer progression.

Androgen receptor regulates SRC expression through microRNA-203.

The SRC kinase has pivotal roles in multiple developmental processes and in tumor progression. An inverse relationship has been observed between androgen receptor (AR) activity and SRC signaling in advanced prostate cancer (PCa); however, the modulation of AR/SRC crosstalk that leads to metastatic PCa is unclear. Here, we showed that patients with high SRC levels displayed correspondingly low canonical AR gene signatures. Our results demonstrated that activated AR induced miR-203 and reduced SRC levels in PCa model systems. miR-203 directly binds to the 3' UTR of SRC and regulates the stability of SRC mRNA upon AR activation. Moreover, we found that progressive PCa cell migration and growth were associated with a decrease in AR-regulated miR-203 and an increase in SRC. Relationships among AR, miR-203, and SRC were also confirmed in clinical datasets and specimens. We suggest that the induction of SRC results in increased PCa metastasis that is linked to the dysregulation of the AR signaling pathway through the inactivation of miR-203.

Mechanisms of cancer metastasis to the bone.

Some of the most common human cancers, including breast cancer, prostate cancer, and lung cancer, metastasize with avidity to bone. What is the basis for their preferential growth within the bone microenvironment? Bidirectional interactions between tumor cells and cells that make up bone result in a selective advantage for tumor growth and can lead to bone destruction or new bone matrix deposition. This review discusses our current understanding of the molecular components and mechanisms that are responsible for those interactions.

Molecular mechanisms of breast cancer metastases to bone.

Bone metastases lead to hypercalcemia, bone pain, fractures, and nerve compression. They cause increased morbidity and mortality in patients with advanced breast cancer. Animal models reproduce many of the features seen in patients with breast cancer and permit identification of tumor- and bone-derived factors important in skeletal metastasis. These factors provide novel targets for therapeutic interventions. Specific tumor-bone molecular interactions mediated by these factors drive a vicious cycle that perpetuates skeletal metastases. In breast cancer, osteolytic metastases are most common, but mixed and osteoblastic metastases occur in a significant number of patients. Parathyroid hormone-related protein is a common osteolytic factor, and vascular endothelial growth factor and interleukins 8 and 11 also contribute. Osteoblastic metastases can be caused by tumor-secreted endothelin-1 (ET-1), but there are a variety of other potential osteoblastic factors. Stimulation of osteoblasts can paradoxically increase osteoclast function, as bone-synthesizing osteoblasts are the main regulators of bone-destroying osteoclasts. Coexpression of osteolytic and osteoblastic factors can thus produce mixed metastases or increased osteolysis. Cancer treatments, especially sex steroid deprivation therapies, stimulate bone loss. Bone resorption results in the release of bone growth factors, which may unintentionally increase the formation of bone metastases by activating the vicious cycle. Clinically approved bisphosphonates prevent bone resorption and reduce the release of bone growth factors. Parathyroid hormone-related protein-neutralizing antibody, inhibitors of the receptor activator of nuclear factor-kB ligand pathway, and ET-1 receptor antagonists are in clinical trials. These agents act on bone cells rather than tumor cells. Recent experiments identify new potential targets for prevention of bone metastases.

Facile and potent synthesis of carbon bridged fullerene dimers (HC60-CR2-C60H type).

Novel carbon bridged fullerene dimers (HC60-CR2-C60H type) are obtained in high yield by the reaction of aminomethylenebis(phosphonate) anions with [60]fullerene.

EGF Receptor Promotes Prostate Cancer Bone Metastasis by Downregulating miR-1 and Activating TWIST1.

Dysregulation of the EGFR signaling axis enhances bone metastases in many solid cancers. However, the relevant downstream effector signals in this axis are unclear. miR-1 was recently shown to function as a tumor suppressor in prostate cancer cells, where its expression correlated with reduced metastatic potential. In this study, we demonstrated a role for EGFR translocation in regulating transcription of miR-1-1, which directly targets expression of TWIST1. Consistent with these findings, we observed decreased miR-1 levels that correlated with enhanced expression of activated EGFR and TWIST1 in a cohort of human prostate cancer specimens and additional datasets. Our findings support a model in which nuclear EGFR acts as a transcriptional repressor to constrain the tumor-suppressive role of miR-1 and sustain oncogenic activation of TWIST1, thereby leading to accelerated bone metastasis.

MicroRNA-34a regulates WNT/TCF7 signaling and inhibits bone metastasis in Ras-activated prostate cancer.

Aberrant activation of Ras and WNT signaling are key events that have been shown to be up-regulated in prostate cancer that has metastasized to the bone. However, the regulatory mechanism of combinatorial Ras and WNT signaling in advanced prostate cancer is still unclear. TCF7, a WNT signaling-related gene, has been implicated as a critical factor in bone metastasis, and here we show that TCF7 is a direct target of miR-34a. In samples of prostate cancer patients, miR-34a levels are inversely correlated with TCF7 expression and a WNT dependent gene signature. Ectopic miR-34a expression inhibited bone metastasis and reduced cancer cell proliferation in a Ras-dependent xenograft model. We demonstrate that miR-34a can directly interfere with the gene expression of the anti-proliferative BIRC5, by targeting BIRC5 3'UTR. Importantly, BIRC5 overexpression was sufficient to reconstitute anti-apoptotic signaling in cells expressing high levels of miR-34a. In prostate cancer patients, we found that BIRC5 levels were positively correlated with a Ras signaling signature expression. Our data show that the bone metastasis and anti-apoptotic effects found in Ras signaling-activated prostate cancer cells require miR-34a deficiency, which in turn aids in cell survival by activating the WNT and anti-apoptotic signaling pathways thereby inducing TCF7 and BIRC5 expressions.

Schisandra chinensis regulates drug metabolizing enzymes and drug transporters via activation of Nrf2-mediated signaling pathway.

Drug metabolizing enzymes (DMEs) and drug transporters are regulated via epigenetic, transcriptional, posttranscriptional, and translational and posttranslational modifications. Phase I and II DMEs and drug transporters play an important role in the disposition and detoxification of a large number of endogenous and exogenous compounds. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is a critical regulator of a variety of important cytoprotective genes that are involved in disposition and detoxification of xenobiotics. Schisandra chinensis (SC) is a commonly used traditional Chinese herbal medicine that has been primarily used to protect the liver because of its potent antioxidative and anti-inflammatory activities. SC can modulate some DMEs and drug transporters, but the underlying mechanisms are unclear. In this study, we aimed to explore the role of Nrf2 in the regulatory effect of SC extract (SCE) on selected DMEs and drug transporters in human hepatocellular liver carcinoma cell line (HepG2) cells. The results showed that SCE, schisandrin A, and schisandrin B significantly increased the expression of NAD(P)H: Nicotinamide Adenine Dinucleotide Phosphate-oxidase or:quinone oxidoreductase 1, heme oxygenase-1, glutamate-cysteine ligase, and glutathione S-transferase A4 at both transcriptional and posttranscriptional levels. Incubation of HepG2 cells with SCE resulted in a significant increase in the intracellular level of glutathione and total glutathione S-transferase content. SCE significantly elevated the messenger ribonucleic acid and protein levels of P-glycoprotein and multidrug resistance-associated protein 2 and 4, whereas the expression of organic anion transporting peptide 1A2 and 1B1 was significantly downregulated by SCE. Knockdown of Nrf2 by small interfering ribonucleic acid attenuated the regulatory effect of SCE on these DMEs and drug transporters. SCE significantly upregulated Nrf2 and promoted the translocation of Nrf2 from cytoplasm to the nuclei. Additionally, SCE significantly suppressed the expression of cytosolic Kelch-like ECH-associated protein 1 (the repressor of Nrf2) and remarkably increased Nrf2 stability in HepG2 cells. Taken together, our findings suggest that the hepatoprotective effects of SCE may be partially ascribed to the modulation of DMEs and drug transporters via Nrf2-mediated signaling pathway. SCE may alter the pharmacokinetics of other coadministered drugs that are substrates of these DMEs and transporters and thus cause unfavorable herb-drug interactions.

Novel targeting of PEGylated liposomes for codelivery of TGF-ß1 siRNA and four antitubercular drugs to human macrophages for the treatment of mycobacterial infection: a quantitative proteomic study.

Tuberculosis (TB) is still a major public health issue in developing countries, and its chemotherapy is compromised by poor drug compliance and severe side effects. This study aimed to synthesize and characterize new multimodal PEGylated liposomes encapsulated with clinically commonly used anti-TB drugs with linkage to small interfering RNA (siRNA) against transforming growth factor-ß1 (TGF-ß1). The novel NP-siRNA liposomes could target THP-1-derived human macrophages that were the host cells of mycobacterium infection. The biological effects of the NP-siRNA liposomes were evaluated on cell cycle distribution, apoptosis, autophagy, and the gene silencing efficiency of TGF-ß1 siRNA in human macrophages. We also explored the proteomic responses to the newly synthesized NP-siRNA liposomes using the stable isotope labeling with amino acids in cell culture approach. The results showed that the multifunctional PEGylated liposomes were successfully synthesized and chemically characterized with a mean size of 265.1 nm. The novel NP-siRNA liposomes functionalized with the anti-TB drugs and TGF-ß1 siRNA were endocytosed efficiently by human macrophages as visualized by transmission electron microscopy and scanning electron microscopy. Furthermore, the liposomes showed a low cytotoxicity toward human macrophages. There was no significant effect on cell cycle distribution and apoptosis in THP-1-derived macrophages after drug exposure at concentrations ranging from 2.5 to 62.5 µg/mL. Notably, there was a 6.4-fold increase in the autophagy of human macrophages when treated with the NP-siRNA liposomes at 62.5 µg/mL. In addition, the TGF-ß1 and nuclear factor-κB expression levels were downregulated by the NP-siRNA liposomes in THP-1-derived macrophages. The Ingenuity Pathway Analysis data showed that there were over 40 signaling pathways involved in the proteomic responses to NP-siRNA liposome exposure in human macrophages, with 160 proteins mapped. The top five canonical signaling pathways were eukaryotic initiation factor 2 signaling, actin cytoskeleton signaling, remodeling of epithelial adherens junctions, epithelial adherens junction signaling, and Rho GDP-dissociation inhibitor signaling pathways. Collectively, the novel synthetic targeting liposomes represent a promising delivery system for anti-TB drugs to human macrophages with good selectivity and minimal cytotoxicity.

Controllable drug uptake and nongenomic response through estrogen-anchored cyclodextrin drug complex.

Breast cancer is a leading killer of women worldwide. Cyclodextrin-based estrogen receptor-targeting drug-delivery systems represent a promising direction in cancer therapy but have rarely been investigated. To seek new targeting therapies for membrane estrogen receptor-positive breast cancer, an estrogen-anchored cyclodextrin encapsulating a doxorubicin derivative Ada-DOX (CDE1-Ada-DOX) has been synthesized and evaluated in human breast cancer MCF-7 cells. First, we synthesized estrone-conjugated cyclodextrin (CDE1), which formed the complex CDE1-Ada-DOX via molecular recognition with the derivative adamantane-doxorubicin (Ada-DOX) (Kd =1,617 M(-1)). The structure of the targeting vector CDE1 was fully characterized using (1)H- and (13)C-nuclear magnetic resonance, mass spectrometry, and electron microscopy. CDE1-Ada-DOX showed two-phase drug-release kinetics with much slower release than Ada-DOX. The fluorescence polarization analysis reveals that CDE1-Ada-DOX binds to recombinant human estrogen receptor α fragments with a Kd of 0.027 µM. Competition assay of the drug complex with estrogen ligands demonstrated that estrone and tamoxifen competed with CDE1-Ada-DOX for membrane estrogen receptor binding in MCF-7 cells. Intermolecular self-assembly of CDE1 molecules were observed, showing tail-in-bucket and wire-like structures confirmed by transmission electronic microscopy. CDE1-Ada-DOX had an unexpected lower drug uptake (when the host-guest ratio was >1) than non-targeting drugs in MCF-7 cells due to ensconced ligands in cyclodextrins cavities resulting from the intermolecular self-assembly. The uptake of CDE1-Ada-DOX was significantly increased when the host-guest ratio was adjusted to be less than half at the concentration of CDE1 over 5 µM due to the release of the estrone residues. CDE1 elicited rapid activation of mitogen-activated protein kinases (p44/42 MAPK, Erk1/2) in minutes through phosphorylation of Thr202/Tyr204 in MCF-7 cells. These results demonstrate a targeted therapeutics delivery of CDE1-Ada-DOX to breast cancer cells in a controlled manner and that the drug vector CDE1 can potentially be employed as a molecular tool to differentiate nongenomic from genomic mechanism.

Identification of Different Classes of Luminal Progenitor Cells within Prostate Tumors.

Primary prostate cancer almost always has a luminal phenotype. However, little is known about the stem/progenitor properties of transformed cells within tumors. Using the aggressive Pten/Tp53-null mouse model of prostate cancer, we show that two classes of luminal progenitors exist within a tumor. Not only did tumors contain previously described multipotent progenitors, but also a major population of committed luminal progenitors. Luminal cells, sorted directly from tumors or grown as organoids, initiated tumors of adenocarcinoma or multilineage histological phenotypes, which is consistent with luminal and multipotent differentiation potentials, respectively. Moreover, using organoids we show that the ability of luminal-committed progenitors to self-renew is a tumor-specific property, absent in benign luminal cells. Finally, a significant fraction of luminal progenitors survived in vivo castration. In all, these data reveal two luminal tumor populations with different stem/progenitor cell capacities, providing insight into prostate cancer cells that initiate tumors and can influence treatment response.