Target For Breast Cancer Therapy Research Articles

Combining hydrophilic chemotherapy and hydrophobic phytotherapy via tumor-targeted albumin\u2013QDs nano-hybrids: covalent coupling and phospholipid complexation approaches

BackgroundThe rationale of this study is to combine the merits of both albumin nanoparticles and quantum dots (QDs) in improved drug tumor accumulation and strong fluorescence imaging capability into one carrier. However, premature drug release from protein nanoparticles and high toxicity of QDs due to heavy metal leakage are among challenging hurdles. Following this platform, we developed cancer nano-theranostics by coupling biocompatible albumin backbone to CdTe QDs and mannose moieties to enhance tumor targeting and reduce QDs toxicity. The chemotherapeutic water soluble drug pemetrexed (PMT) was conjugated via tumor-cleavable bond to the albumin backbone for tumor site-specific release. In combination, the herbal hydrophobic drug resveratrol (RSV) was preformulated as phospholipid complex which enabled its physical encapsulation into albumin nanoparticles.ResultsAlbumin–QDs theranostics showed enhanced cytotoxicity and internalization into breast cancer cells that could be traced by virtue of their high fluorescence quantum yield and excellent imaging capacity. In vivo, the nanocarriers demonstrated superior anti-tumor effects including reduced tumor volume, increased apoptosis, and inhibited angiogenesis in addition to non-immunogenic response. Moreover, in vivo bioimaging test demonstrated excellent tumor-specific accumulation of targeted nanocarriers via QDs-mediated fluorescence.ConclusionMannose-grafted strategy and QD-fluorescence capability were beneficial to deliver albumin nanocarriers to tumor tissues and then to release the anticancer drugs for killing cancer cells as well as enabling tumor imaging facility. Overall, we believe albumin–QDs nanoplatform could be a potential nano-theranostic for bioimaging and targeted breast cancer therapy.

USP17 Suppresses Tumorigenesis and Tumor Growth through Deubiquitinating AEP.

Ubiquitin-specific protease 17 (USP17), a novel member of deubiquitinase, is reported to play essential roles in several solid tumors. However, the expression and function of USP17 in breast cancer tumorigenesis remains ambiguity. Here we found that the mRNA level of USP17 was lower in breast cancer tissues than normal tissues. Meanwhile, higher USP17 level was detected in normal epithelial cell MCF-10A and a less-malignant cell MCF-7 than malignant cell line MDA-MB-231. Inhibition of USP17 in MCF7 cells enhanced tumorigenesis and tumor growth while overexpression of USP17 in malignant MDA-MB-231 cells reduced its tumorigenesis and growth ability in vitro and in vivo. Further study revealed that USP17 interacted with and deubiquitinated Asparaginyl endopeptidase (AEP), resulting in decreased protein levels of AEP. Moreover, knockdown of AEP inhibited breast cancer tumorigenesis and growth in vitro and in vivo through the inactivation of ERK signaling. Taken together, our works indicate that USP17 deubiquitinates AEP, down-regulates its protein level, and inhibits breast cancer tumorigenesis through disturbing ERK signaling. Thus, our data suggests that USP17 is a potential tumor suppressor in breast cancer and AEP is a promising target in breast cancer therapy.

乳腺癌相关成纤维细胞：乳腺癌治疗的新靶点

乳腺癌相关成纤维细胞：乳腺癌治疗的新靶点

Molecular insight into the T798M gatekeeper mutation-caused acquired resistance to tyrosine kinase inhibitors in ErbB2-positive breast cancer

Human epidermal growth factor receptor 2 (ErbB2) is an attractive therapeutic target for metastatic breast cancer. The kinase has been clinically observed to harbor a gatekeeper mutation T798M in its active site, which causes acquired resistance to the first-line targeted breast cancer therapy with small-molecule tyrosine kinase inhibitors. Previously, several theories have been proposed to explain the molecular mechanism of gatekeeper mutation-caused drug resistance, such as blocking of inhibitor binding and increasing of ATP affinity. In the current study, the direct binding of three wild type-selective inhibitors (Lapatinib, AEE788 and TAK-285) and two wild type-sparing inhibitors (Staurosporine and Bosutinib) to the wild-type ErbB2 and its T798M mutant are investigated in detail by using rigorous computational analysis and binding affinity assay. Substitution of the polar threonine with a bulky methionine at residue 798 can impair and improve the direct binding affinity of wild type-selective and wild type-sparing inhibitors, respectively. Hindrance effect is responsible for the affinity decrease of wild type-selective inhibitors, while additional nonbonded interactions contribute to the affinity increase of wild type-sparing inhibitors, thus conferring selectivity to the inhibitors for mutant over wild type. The binding affinity of Staurosporine and Bosutinib to ErbB2 kinase domain is improved by 11.9-fold and 2.1-fold upon T798M mutation, respectively. Structural analysis reveals that a nonbonded network of S–π contact interactions (for Staurosporine) or an S-involving halogen bond (for Bosutinib) forms with the sulfide group of mutant Met798 residue.

MARCH5 overexpression contributes to tumor growth and metastasis and associates with poor survival in breast cancer.

BackgroundHuman MARCH5 is a mitochondrial localized E3 ubiquitin-protein ligase that is critical for the regulation of mitochondrial dynamics. A body of evidence has indicated the close links between unbalanced mitochondrial dynamics and cancers. However, the expression, biological functions, and prognostic significance of MARCH5 in breast cancer (BC) have not been determined.Materials and methodsThe mRNA and protein expressions of MARCH5 were evaluated by quantitative real-time PCR and Western blot analysis in BC cell lines and tumor tissues. Clinical prognostic significance of MARCH5 was assessed in 65 patients with BC. The biological functions of MARCH5 were determined by in vitro cell proliferation, apoptosis, cell cycle, migration and invasion assays, and in vivo tumor growth and metastasis assays through knockdown or overexpression of MARCH5 in BC cells. In addition, the underlying mechanisms by which MARCH5 regulated BC cell growth and metastasis were explored.ResultsMARCH5 was substantially upregulated in BC cells mainly due to the downregulation of miR-30a, which contributed to the poor survival of BC patients. MARCH5 promoted the growth and metastasis of BC cells both in vitro and in vivo by inducing G1–S cell cycle arrest and epithelial–mesenchymal transition. Mechanistic investigations revealed that the oncogenic effect of MARCH5 was mainly mediated by increased mitochondrial fission and subsequent ROS production in BC cells.ConclusionOur findings demonstrate that MARCH5 plays a critical oncogenic role in BC cells, which provides experimental evidence supporting MARCH5 as a potential therapeutic target in BC therapy.

Putative tumor suppressor cytoglobin promotes aryl hydrocarbon receptor ligand-mediated triple negative breast cancer cell death.

Nearly 40 000 women die annually from breast cancer in the United States. Clinically available targeted breast cancer therapy is largely ineffective in triple negative breast cancer (TNBC), characterized by tumors that lack expression of the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (Her2). TNBC is associated with a poor prognosis. Previous reports show that aryl hydrocarbon receptor (AhR) partial agonist 2-(4-amino-3-methylphenyl)-5-fluorobenzothiazole (5F 203) selectively inhibits the growth of breast cancer cells, including those of the TNBC subtype. We previously demonstrated that 5F 203 induced the expression of putative tumor suppressor gene cytoglobin (CYGB) in breast cancer cells. In the current study, we determined that 5F 203 induces apoptosis and caspase-3 activation in MDA-MB-468 TNBC cells and in T47D ER+ PR + Her2 - breast cancer cells. We also show that caspases and CYGB promote 5F 203-mediated apoptosis in MDA-MB-468 cells. 5F 203 induced lysosomal membrane permeabilization (LMP) and cathepsin B release in MDA-MB-468 and T47D cells. In addition, silencing CYGB attenuated the ability of 5F 203 to induce caspase-3/-7 activation, proapoptotic gene expression, LMP, and cathepsin B release in MDA-MB-468 cells. Moreover, 5F 203 induced CYGB protein expression, proapoptotic protein expression, and caspase-3 cleavage in MDA-MB-468 cells and in MDA-MB-468 xenograft tumors grown orthotopically in athymic mice. These data provide a basis for the development of AhR ligands with the potential to restore CYGB expression as a novel strategy to treat TNBC.

Cytotoxic Effects of Cucurbitacin I and Ecballium elaterium on Breast Cancer Cells

The objective of this study was to investigate the inhibitory effect of cucurbitacin I (CuI) and Ecballium elaterium L. (fruit juice and chloroform extract) on breast cancer cells (MCF-7 and MDA-MB-231). The CuI content of E. elaterium fruit juice and chloroform extract was quantified using high performance liquid chromatography. The cytotoxic effects of the fruit juice, chloroform extract and CuI were determined by MTT, wound healing and colony formation assays; all had an anti-proliferative activity on the breast cancer cells. Clarifying the mechanisms of cucurbitacins will enable the identification of new molecular targets for breast cancer therapy.

MiRNA-224-5p inhibits autophagy in breast cancer cells via targeting Smad4

Background/aimsAutophagy is known as a protective intracellular procedure, which can be regulated by several factors. MiRNA has been suggested as a potential element to mediate autophagy pathway in carcinomas. Our study was aim to investigate the role of autophagy in breast cancer cells and identify the involved molecular mechanism MethodsThe expression of LC3I/II, SQSTM1 and Smad4 were detected by western blot. The mRNA level were quantified by real-time PCR. MDC staining was used to directly visualize autophagosome formation. Target Scan 7.2 was used to predict biological targets of miR-224-5p ResultsMiR-224 -5p expression was upregulated in metastatic breast cancer and non-metastatic breast cancer cells compare with control. Moreover, miR-224-5p inhibition enhanced cellular autophagy levels in breast cancer cells. MiR-224-5p could suppress Smad4 expression in MDA-MB-231 cells, which indicated that Smad4 was identified as a target of miR-224-5p in breast cancer cells with high metastatic potential ConclusionsOur study revealed that miR-224-5p inhibited autophagy by targeting Smad4 in MDA-MB-231 cells. The results indicated that miR-224-5p/Smad4 regulating autophagy might be a novel regulatory network contributing to metastasis of breast cancer. MiR-224-5p and Smad4 is involved in breast tumorigenesis, which is possibly a novel target for breast cancer therapy.

Knockdown of DNA/RNA-binding protein KIN17 promotes apoptosis of triple-negative breast cancer cells.

Effective therapy for breast cancer has been extensively studied worldwide, particularly for triple-negative breast cancer and drug-resistant subtypes. DNA/RNA-binding protein KIN17 (kin17) has been reported to be significantly upregulated in breast cancer cells, and is proposed to serve a role in the regulation of cell proliferation. The present study further investigated the association of kin17-knockdown with breast cancer cell apoptosis. Cell Counting kit-8, flow cytometry, TUNEL assay and caspase 3/7 analysis were performed on MDA-MB-231 cells to determine the association between kin17 and breast cancer cell apoptosis. In addition, western blot analysis was performed to investigate the mechanism of kin17 in the apoptosis of MDA-MB-231 cells. The results revealed that knockdown of kin17 inhibited proliferation and promoted apoptosis of MDA-MB-231 cells, and suggested a poly (adenosine diphosphate-ribose) polymerase-related mechanism behind the apoptosis of the cells. These findings suggested that kin17 could become a novel target for breast cancer therapy.

Functional role of RRS1 in breast cancer cell proliferation.

RRS1 (human regulator of ribosome synthesis 1), an essential nuclear protein involved in ribosome biogenesis, is overexpressed in some human cancers, yet its role in breast cancer remains unclear. Here, we report a functional analysis of RRS1 in breast cancer and its likely mechanism. Immunohistochemistry (IHC) and RT‐qPCR analyses indicated that RRS1 was commonly overexpressed in breast cancer tissues. The copy numbers of RRS1 were higher in tumours compared with those for normal tissues. And there was a significant correlation between copy number and mRNA expression. In addition, RRS1 overexpression was significantly correlated with lymph node metastasis and poor survival. RRS1 mRNA and protein levels were also significantly increased in a panel of human breast cancer cell lines. RRS1 knockdown inhibited proliferation and induced apoptosis and cell cycle arrest in all three cell lines. Furthermore, RRS1 knockdown suppressed the tumour formation and growth of MDA‐MB‐231 cells in nude mice. Additionally, RRS1 knockdown activated p53 and p21 in MCF‐7 cells. A marked increase in the quantity of ribosome‐free RPL11 was detected by Western blot. Moreover, co‐immunoprecipitation (CoIP) experiments showed that RRS1 knockdown activated p53 by facilitating the direct contact of MDM2 and RPL11/RPL5. Taken together, our results suggest that RRS1 may contribute to breast cancer proliferation through RPL11/MDM2‐mediated p53 activation. Therefore, RRS1 may be a promising target for breast cancer therapy.

Trastuzumab decorated TPGS-g-chitosan nanoparticles for targeted breast cancer therapy.

Breast cancer, up-regulated with human epidermal growth factor receptor type-2 (HER-2) has led to the concept of developing HER-2 targeted anticancer therapeutics. Docetaxel-loaded D-α-tocopherol polyethylene glycol 1000 succinate conjugated chitosan (TPGS-g-chitosan) nanoparticles were prepared with or without Trastuzumab decoration. The particle size and entrapment efficiency of conventional, non-targeted as well as targeted nanoparticles were in the range of 126-186 nm and 74-78% respectively. In-vitro studies on SK-BR-3 cells showed that docetaxel-loaded non-targeted and HER-2 receptor targeted TPGS-g-chitosan nanoparticles have enhanced the cellular uptake and cytotoxicity with a promising bioadhesion property, in comparison to conventional formulation i.e., Docel™. The IC50 values of non-targeted and targeted nanoparticles from cytotoxic assay were found to be 43 and 223 folds higher than Docel™. The in-vivo pharmacokinetic study showed 2.33, and 2.82-fold enhancement in relative bioavailability of docetaxel for non-targeted and HER-2 receptor targeted nanoparticles, respectively than Docel™. Further, after i.v administration, non-targeted and targeted nanoparticles achieved 3.48 and 5.94 times prolonged half-life in comparison to Docel™. The area under the curve (AUC), relative bioavailability (FR) and mean residence time (MRT) were found to be higher for non-targeted and targeted nanoparticles when compared to Docel™. The histopathology studies of non-targeted and targeted nanoparticles showed less toxicity on vital organs such as lungs, liver, and kidney when compared to Docel™.

Breast cancer stem cells and the challenges of eradication: a review of novel therapies.

Breast cancer is a heterogeneous disease that accounts for 30% of all cancers diagnosed in women and over half a million deaths per year. Cancer stem cells (CSCs) make up a small subpopulation of cells within a tumor, are capable of self-renewal and, are responsible for tumor initiation, formation, and recurrence. Breast CSCs (BCSCs) have been the subject of concentrated research as potential targets for breast cancer therapies. Cell surface markers CD44+/CD24- have been established as minimum biomarkers for BCSCs and the upregulation of CD44 expression has been linked to tumor formation in numerous cancers. Additionally, the deregulation of Notch, Wnt/Frizzled/β-catenin, Hippo, and Hedgehog signaling pathways is believed to be responsible for the formation of CSCs and lead to tumor formation. Tumor heterogeneity is a key feature of therapy resistance and a major challenge. CSCs are predominantly senescent and inherently immune to chemotherapy drugs which rely on an overactive cell cycle. Current therapeutic strategies include targeting CSC signaling pathways that play critical roles in self-renewal and defense. Anti-CD44 antibodies have been shown to induce terminal differentiation in CSCs resulting in a significant decrease in tumor metastasis. Additionally, targeting the tumor microenvironment has been shown to increase the effectiveness of chemotherapy drugs. In this review, we attempt to provide an overview of breast cancer, the stem of its cause, and novel therapies currently being explored.

Aromatase Acetylation Patterns and Altered Activity in Response to Sirtuin Inhibition.

Aromatase, a cytochrome P450 member, is a key enzyme involved in estrogen biosynthesis and is dysregulated in the majority of breast cancers. Studies have shown that lysine deacetylase inhibitors (KDI) decrease aromatase expression in cancer cells, yet many unknowns remain regarding the mechanism by which this occurs. However, advances have been made to clarify factors involved in the transcriptional regulation of the aromatase gene (CYP19A1). Yet, despite aromatase being a primary target for breast cancer therapy, its posttranslational regulation has been virtually unexplored. Acetylation is a posttranslational modification (PTM) known to alter the activity and stability of many oncoproteins, and given the role of KDIs in regulating aromatase expression, we postulate that aromatase acetylation acts as a novel posttranslational regulatory mechanism that impacts aromatase expression and/or activity in breast cancer. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis revealed that aromatase is basally acetylated on several lysine residues (108, 169, 242, 262, 334, 352, and 354) in MCF-7 cells, and treatment with a SIRT-1 inhibitor induced additional acetylation (376, 390, 440, and 448). These acetylated lysine residues are in regions critical for aromatase activity. Site-directed mutagenesis and overexpression studies demonstrated that K108R/Q or K440R/Q mutations significantly altered aromatase activity in breast cancer cells without altering its subcellular localization.Implications: These findings demonstrate a novel posttranslational regulation of aromatase and uncover novel anticancer effects of deacetylase inhibitors, thus providing new insight for ongoing development of deacetylase inhibitors as cancer therapeutics. Mol Cancer Res; 16(10); 1530-42. ©2018 AACR.

Deglycosylation of epithelial cell adhesion molecule affects epithelial to mesenchymal transition in breast cancer cells.

The transmembrane glycoprotein epithelial cell adhesion molecule (EpCAM) is overexpressed in most epithelial cancers including breast cancer, where it plays an important role in cancer progression. Previous study has demonstrated that knockdown of EpCAM inhibits breast cancer cell growth and metastasis via inhibition of the Ras/Raf/ERK signaling pathway and matrix metallopeptidase-9 (MMP-9). Although glycosylation is believed to be associated with the function of EpCAM, the contribution of N-glycosylation to this function remains unclear. We constructed the N-glycosylation mutation plasmid of EpCAM and used it to treat breast cancer cells. Loss of N-glycosylation at all three sites EpCAM had no effect on its level of expression or membrane localization. However, mutation at glycosylation sites significantly reduced the ability of EpCAM to promote epithelial to mesenchymal transition in breast cancer. N-glycosylation mutation of EpCAM led to decrease phosphorylation of Raf, ERK, and Akt, and inhibited the Ras/Raf/ERK and PI3K/Akt signaling pathways. Furthermore, we demonstrated that N-glycosylation mutation of EpCAM-mediated invasion and metastasis of breast carcinoma cells required the downregulation of MMP-9 via inhibition of these two signaling pathways. Our results identified the characteristics and function of EpCAM glycosylation. These data could illuminate molecular regulation of EpCAM by glycosylation and promote our understanding of the application of glycosylated EpCAM as a target for breast cancer therapy.

Transcriptomic but not genomic variability confers phenotype of breast cancer stem cells

BackgroundBreast cancer stem cells (BCSCs) are considered responsible for cancer relapse and drug resistance. Understanding the identity of BCSCs may open new avenues in breast cancer therapy. Although several discoveries have been made on BCSC characterization, the factors critical to the origination of BCSCs are largely unclear. This study aimed to determine whether genomic mutations contribute to the acquisition of cancer stem-like phenotype and to investigate the genetic and transcriptional features of BCSCs.MethodsWe detected potential BCSC phenotype-associated mutation hotspot regions by using whole-genome sequencing on parental cancer cells and derived serial-generation spheres in increasing order of BCSC frequency, and then performed target deep DNA sequencing at bulk-cell and single-cell levels. To identify the transcriptional program associated with BCSCs, bulk-cell and single-cell RNA sequencing was performed.ResultsBy using whole-genome sequencing of bulk cells, potential BCSC phenotype-associated mutation hotspot regions were detected. Validation by target deep DNA sequencing, at both bulk-cell and single-cell levels, revealed no genetic changes specifically associated with BCSC phenotype. Moreover, single-cell RNA sequencing showed profound transcriptomic variability in cancer cells at the single-cell level that predicted BCSC features. Notably, this transcriptomic variability was enriched during the transcription of 74 genes, revealed as BCSC markers. Breast cancer patients with a high risk of relapse exhibited higher expression levels of these BCSC markers than those with a low risk of relapse, thereby highlighting the clinical significance of predicting breast cancer prognosis with these BCSC markers.ConclusionsTranscriptomic variability, not genetic mutations, distinguishes BCSCs from non-BCSCs. The identified 74 BCSC markers have the potential of becoming novel targets for breast cancer therapy.

Hyaluronic acid-capped compact silica-supported mesoporous titania nanoparticles for ligand-directed delivery of doxorubicin

Mesoporous titania nanoparticles (MTN), owing to their high surface area to volume ratio and tunable pore sizes, appear capable of delivering sizable amounts of drug payloads, and hence, show considerable promise as drug delivery candidates in cancer therapy. We designed silica-supported MTN (MTNst) coated with hyaluronic acid (HA) to effectively deliver doxorubicin (DOX) for breast cancer therapy. The HA coating served a dual purpose of stabilizing the payload in the carriers as well as actively targeting the nanodevices to CD44 receptors. The so-formed HA-coated MTNst carrying DOX (HA/DOX-MTNst) had spheroid particles with a considerable drug-loading capacity and showed significantly superior in vitro cytotoxicity against MDA-MB-231 cells as compared to free DOX. HA/DOX-MTNst markedly improved the cellular uptake of DOX in an apparently CD44 receptor-dependent manner, and increased the number of apoptotic cells as compared to free DOX. These nanoplatforms accumulated in large quantities in the tumors of MDA-MB-231 xenograft tumor-bearing mice, where they significantly enhanced the inhibition of tumor growth compared to that observed with free DOX with no signs of acute toxicity. Based on these excellent results, we deduced that HA/DOX-MTNst could be successfully used for targeted breast cancer therapy. Statement of SignificanceThis is the first study to use silica-supported mesoporous titania nanoparticles (MTNst) for doxorubicin (DOX) delivery to treat breast cancer, which exhibited effective and enhanced in vitro and in vivo apoptosis and tumor growth inhibition. Solid silica was used to support the mesoporous TiO2 resulting in MTNst, which efficiently incorporated a high DOX payload. The hyaluronic acid (HA) coating over the MTNst surface served a dual purpose of first, stabilizing DOX inside the MTNst (capping agent), and second, directing the nanoplatform device to CD44 receptors that are highly expressed in MDA-MB-231 cells (targeting ligand). The NPs exhibited highly efficacious in vitro tumor-cell killing and excellent in vivo tumor regression, highlighting the enormous promise of this system for breast cancer therapy.

Intratumor heterogeneity ofHMCN1mutant alleles associated with poor prognosis in patients with breast cancer

Human breast cancers comprise a complex and highly heterogeneous population of tumor cells. Intratumor heterogeneity is an underlying cause of resistance to effective therapies and disease recurrence. To explore prognostic factors based on intratumor heterogeneity, we analyzed genomic mutations in breast cancer patients registered in The Cancer Genome Atlas. We calculated the variant allele frequency (VAF) at each mutation site and evaluated the associations of VAFs with the prognosis of breast cancer. VAFs of HMCN1 correlated with the prognosis and lymph node status. Although the detailed function of HMCN1 remains unknown, it is located in extracellular matrix and the mutation in the gene might be associated with cancer cell invasion and metastasis. This finding suggests that HMCN1 is a potential metastatic factor and can be a candidate gene for targeted breast cancer therapy.

MicroRNAs and DNA-Damaging Drugs in Breast Cancer: Strength in Numbers.

MicroRNAs are a class of small non-coding regulatory RNAs playing key roles in cancer. Breast cancer is the most common female malignancy worldwide and is categorized into four molecular subtypes: luminal A and B, HER2+ and triple-negative breast cancer (TNBC). Despite the development of multiple targeted therapies for luminal and HER2+ breast tumors, TNBC lacks specific therapeutic approaches, thus they are treated mainly with radio- and chemotherapy. The effectiveness of these therapeutic regimens is based on their ability to induce DNA damage, which is differentially resolved and repaired by normal vs. cancer cells. Recently, drugs directly targeting DNA repair mechanisms, such as PARP inhibitors, have emerged as attractive candidates for the future molecular targeted-therapy in breast cancer. These compounds prevent cancer cells to appropriate repair DNA double strand breaks and induce a phenomenon called synthetic lethality, that results from the concurrent inhibition of PARP and the absence of functional BRCA genes which prompt cell death. MicroRNAs are relevant players in most of the biological processes including DNA damage repair mechanisms. Consistently, the downregulation of DNA repair genes by miRNAs have been probe to improve the therapeutic effect of genotoxic drugs. In this review, we discuss how microRNAs can sensitize cancer cells to DNA-damaging drugs, through the regulation of DNA repair genes, and examine the most recent findings on their possible use as a therapeutic tools of treatment response in breast cancer.

Abstract B06: Similarity in breast cancer diversity: A novel target for breast cancer therapy

Abstract There is cancer; there is breast cancer (BCA); then there is luminal-A BCA, luminal-B BCA, HER2-enriched BCA, triple-negative/basal-like BCA; and, yes, normal-like BCA. In each of these distinct forms of BCA, unique targetable vulnerabilities in the tumors’ biologic makeup have been exploited, in many cases rather successfully, for drug development. To be sure, this divide and conquer approach has worked to a point. However, limitations include the targeting of proteins that, while overexpressed in a particular cancer, are also found in normal cells and the fact that many of these targets appear in very small subsets of BCA and thus the need to extensively type each cancer and to treat each individual cancer in a very specific fashion. Here, we are proposing another time-proven success strategy: unite and govern. We are targeting a commonality within the diverse array of breast cancers: the ASPH gene and its product, human aspartyl (asparaginyl) β-hydroxylase (HAAH). This enzyme has been detected specifically in more than 90% of all breast cancers by immunostaining (IHC/ICC), gene expression analysis (RT-PCR), and immunoassay (serum ELISA). When normal cells are transfected with ASPH, as HAAH is produced and translocated to the surface, they undergo malignant transformation and when ASPH is silenced in tumor cells, they revert to normal phenotype. Moreover, HAAH has a pivotal role in cell proliferation, motility, and invasiveness, the hallmarks of cancer. Also, the HAAH level in tumors is directly correlated with severity of disease and patient survival. HAAH is an embryonic enzyme silenced post-birth, and as such it is a self-protein. We have designed, produced, tested, manufactured, and are now clinically evaluating an HAAH-targeting therapeutic vaccine. This vaccine has effectively overcome self-tolerance and has the ability to become the ultimate cancer immunotherapy agent. In syngeneic rodent models, it is highly immunogenic, and in challenge models using various cell lines, including BCA lines, it has been effective in preventing tumor growth (up to 100%), reducing tumor size (over 90%), controlling metastasis (to over 80%), and increasing survival (to 100%). Even using a full human dose (40 μg total protein), no animal toxicities were reported (FDA-reviewed protocol). The vaccine is introduced intradermally using 3M’s hollow microneedle array device. In the ongoing phase I clinical trial, to date there have been no adverse complications or side effects reported. Furthermore, the vaccine has been demonstrated to be significantly immunogenic. We are now planning phase 2 clinical trials and propose to use this therapeutic cancer vaccine in HAAH-positive breast cancer patients (as high as 90% of all breast cancers). We intend to extend the clinical trials ultimately to all HAAH-positive cancer patients. Citation Format: Michael S. Lebowitz, Steven Fuller, Hossein A. Ghanbari. Similarity in breast cancer diversity: A novel target for breast cancer therapy [abstract]. In: Proceedings of the AACR Special Conference: Advances in Breast Cancer Research; 2017 Oct 7-10; Hollywood, CA. Philadelphia (PA): AACR; Mol Cancer Res 2018;16(8_Suppl):Abstract nr B06.

Abstract B24: Met and VDAC1 as target for breast cancer therapy

Abstract During the past decade, considerable efforts have been devoted to the identification of agents that selectively kill neoplastic breast cancer cells based on their signaling and metabolic alterations. We hypothesis that combination tyrosine kinase and metabolic inhibitors are potential novel therapies for breast cancer. Aberrant signaling through Met-tyrosine kinase receptor and its ligand hepatocyte growth factor/scatter factor (HGF/SF) has been shown to play a critical role in development of tumors and metastasis in a variety of cancers, including breast cancer. We have previously shown that HGF/SF-induced Met-activation leads to diverse metabolic alteration in the tumor. Activation of Met signaling increases glycolytic flux into lactate and increases glycolysis, oxidative phosporylation, oxygen consumption, and tumor blood volume. The voltage-dependent anion channel 1 (VDAC1), located in the mitochondrial outer membrane, functions as gatekeeper for the entry and exit of mitochondrial metabolites, thereby controlling crosstalk between mitochondria and the rest of the cell. VDAC1 is also a key player in mitochondria-mediated apoptosis. Thus, in addition to regulating the metabolic and energetic functions of mitochondria, VDAC1 appears to act as a convergence point for a variety of cell survival and cell death signals, mediated by its association with various ligands and proteins. Shoshan-Barmatz’s lab developed the retro-Tf-D-LP4 peptide, a cell-penetrating VDAC1-based peptide that acts by inducing apoptosis and impairment of cell energy and metabolism. To study the possible therapeutic effect of Met inhibition and alteration of VDAC1 combined therapy on breast tumor cells, we evaluated cell proliferation and motility in BC cells. Using our newly developed single-cell 35 parameters morphokinetic analysis infrastructure, we demonstrate that after 24 hours, the peptide decreased all cell lines velocity (5µM; MDMDA-MB-231_velocity=8.2%, p=0.024. 15µM; MDMDA-MB-231_velocity=62.4%, p<0.001). The peptide in combination with Met inhibitor further decreased cell velocity and acceleration (MDMDA-MB-231_Velocity=85.9%, p<0.001; MDMDA-MB-231_Acceleration=76%, p<0.001). The combined treatment increased cell coordination but abrogated the back-propagating wave. The morphologic effect of the treatment was dependent on the cell line. Cluster analysis of morphokinetic parameters demonstrated that untreated or low doses of treatment MDA-MB-231 and HB2 are clustered together; MCF7 and T47D have slower motility parameters. Upon high-dose combined treatment MDA-MB-231 cells change are clustered with slow-velocity T47D and MCF7. Combined Met inhibition and VDAC1 alteration dramatically reduced cell motility and increased coordinated motility. In vitro experiments show a slight inhibitory effect of VDAC1 on MDA-MB-231 cell proliferation. However, in vivo experiments demonstrate an inhibitory effect on tumor growth. These results indicate that the combined therapy can reduce cell motility and metastasis in triple-negative breast cancer tumors. Citation Format: Guy Namir, Varda Shoshan-Barmatz, Ilan Tsarfaty. Met and VDAC1 as target for breast cancer therapy [abstract]. In: Proceedings of the AACR Special Conference: Advances in Breast Cancer Research; 2017 Oct 7-10; Hollywood, CA. Philadelphia (PA): AACR; Mol Cancer Res 2018;16(8_Suppl):Abstract nr B24.