MDA-MB-468 Research Articles

Chemical Profiling, Antioxidant, Antiproliferative, and Antibacterial Potentials of Chemically Characterized Extract of Citrullus colocynthis L. Seeds

Background: Citrullus colocynthis L. (C. colocynthis) is commonly known as colocynth. It belongs to the family Cucurbitaceae that is frequently used in alternative medicine in the north of Africa. The aim of the study: the present research was undertaken to investigate the chemical composition, antioxidant, antiproliferative, and antibacterial potentials of C. colocynthis seed extract. Material and methods: the chemical composition of C. colocynthis seed organic extract was characterized using gas chromatography/mass spectrometry (GC-MS). The antioxidant property was carried out using both β-carotene bleaching and DPPH assays. The antibacterial effect was effectuated using the agar disc diffusion method. The antiproliferative activity vs. human colorectal adenocarcinoma cell line (HT-29) and human breast adenocarcinoma cell line (MDA MB 231) were carried by WST-1 test. The chemical analysis showed the presence of interesting potentially bioactive compounds. The studied plant extract exhibited antioxidant potential with IC50 value of 2. 22 mg/mL (β-carotene bleaching) and 8.98 ± 0.619 mg/mL (DPPH). Concerning the antiproliferative activity, the seed extract was effective in MDA-MB-231 and HT-29 cancer cells with IC50 values 86.89 ± 3.395 and 242.1 ± 17.9 μg/mL, respectively, whilst the extract of Citrullus colocynthis seeds was non-toxic in healthy human dermal fibroblasts. Regarding the antibacterial test, the extract was effective in Gram-positive bacteria only. Conclusion: The outcome of this research indicated that the extracts from C. colocynthis seeds may compose a promising source with interesting compounds that can be used to fight cancer, free radicals damage, and bacterial infections.

Vitamin D3/phospholipid complex decorated caseinate nanomicelles for targeted delivery of synergistic combination therapy in breast cancer

Targeted delivery of cytotoxic drugs has shown great potential in cancer therapy. In this light, vitamin D3 (vit.D3)-coated micelles were fabricated to encapsulate the cytotoxic drug; etoposide (ETP). Sodium caseinate micelles were first utilized to encapsulate vit.D3 and ETP within their hydrophobic core, then drug-loaded micelles were further decorated with an envelope of vit.D3/ phospholipid complex to enhance the active targeting potency of fabricated micelles via exploiting vit.D3 receptors (VDRs) overexpressed on the outer surface of breast cancer cells. In vitro cytotoxicity studies showed that fabricated micelles exhibited improved anticancer effect on MDA MB-231 and MCF-7 human breast cancer cell lines in comparison to free vit.D3 + ETP without any significant toxicity on normal human lung fibroblast (Wi-38) cells. In vivo biodistribution and efficacy studies in Ehrlich ascites tumor animal model revealed that fabricated micelles manifested improved accumulation in tumor tissue due to active targeting potential of vit.D3 without any remarkable toxicity. More importantly, fabricated micelles resulted in enhanced tumor apoptosis, reduced angiogenesis, invasion and autophagy, besides a decline in the tumor expression levels of both miR-21 and miR-192. Therefore, vit.D3/ETP micelles could serve as a favorable actively targeted anticancer delivery system having a superior effect over the free combination.

Synthesis, self-assembly and drug release study of a new dual-responsive biocompatible block copolymer containing phenylalanine derivative

Stimuli-responsive polymers as drug delivery vehicles have generated remarkable interest among polymer researchers during the last decade. In the present work, we report the synthesis of a new water soluble pH- and thermo-responsive biocompatible block copolymer containing phenylalanine derivatives. The block copolymer formed micelle-like self-assembled nanoparticles above critical aggregation concentration, as confirmed from fluorescence spectroscopy, DLS, and AFM studies. The self-assembly behavior was dependent on the pH and temperature of the aqueous media. These self-assembled micellar nanoparticles were capable of encapsulating hydrophobic drugs as demonstrated by the significantly higher loading capacity value of Doxorubicin (DOX) compared to commonly reported values in the literature. The release of DOX from the nanoparticles was favored at lower pH and higher temperature, a condition prevalent in cancer cells. Biocompatibility of the block copolymer and the effectiveness of the nanoparticles in potential cancer therapy were established by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) studies using non-cancerous murine fibroblasts L929 cells and breast cancer cell line MDA MB 231 at 37 °C and 42 °C. The cytotoxicity of DOX loaded polymer nanoparticles was found to be more effective at 42 °C compared to 37 °C. Thus, these micellar nanoparticles hold promise in drug delivery application in cancer therapy.

Abstract 2387: Targeting PVT1 exon 9 transcript is not pro-apoptotic but induces claudin 4 expression and inhibits migration in triple negative breast cancer cells

Abstract Triple negative breast cancer (TNBC) is a lethal molecular subtype of invasive breast cancer (BC) that is ER-, PR- and HER2-. Claudin low (CL) TNBC, a distinct molecular subtype of TNBC, has the worst prognosis compared to other BC subtypes. Aberrant expression of claudin proteins disrupts the function of tight junctions. Consequently, inducing epithelial-to-mesenchymal transition (EMT) in cancers, an important factor for enhanced motility and metastasis. Therefore, understanding the molecular mechanisms that modulate claudin expression in TNBC is crucial. The 8q24 genomic locus is an important cancer susceptibility locus that is associated with poor clinical outcomes in cancer due to common amplification events that occur in many malignant diseases. This locus contains the PVT1 gene, which encodes a long noncoding RNA (lncRNA) that has been implicated in multiple cancers including BC. PVT1 consists of 12 exons that are alternatively spliced to generate lncRNAs. Although previous research has implicated PVT1 as an important player in BC, the underlying molecular mechanisms of PVT1 in CL TNBC is unknown. To examine the role of PVT1 in CL TNBC, we assessed PVT1 expression in T47D (ER+), MDA MB 231 (CL) and MDA MB 468 (claudin high (CH)) BC cells. We observed that PVT1 exons 4A, 4B, and 9 are significantly overexpressed in CL MDA MB 231 and significantly underexpressed in CH MDA MB 468 in comparison to T47D cells, suggesting a protumorigenic role of PVT1 in CL TNBC. We analyzed the functional consequences of siRNA targeting of PVT1 exon 9 expression in CL TNBC cells. siRNA targeting of PVT1 exon 9 expression in the MDA MB 231 CL TNBC cells led to a significant reduction in migration and the re-expression of claudin 4. To determine the role of PVT1 on EMT, we assessed the expression of EMT markers (vimentin, fibronectin, and E-cadherin) in MDA MB 231 cells. We observed no changes in the expression of EMT markers when PVT1 exon 9 is knocked down. However, our data show that mesenchymal markers are more highly expressed in MDA MB 231 cells in comparison to MDA MB 468 cells. Further, knockdown of PVT1 exon 9 did not induce apoptosis in MDA MB 231 cells as assessed by caspase 3 and caspase 9 expression. Taken together, our data indicate that PVT1 exon 9 regulates claudin expression and migration in CL TNBC, and may have implications for clinical outcomes in TNBC. Citation Format: Fayola A. Levine, Olorunseun O. Ogunwobi. Targeting PVT1 exon 9 transcript is not pro-apoptotic but induces claudin 4 expression and inhibits migration in triple negative breast cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2387.

Abstract 2411: CEACAM1 is a Critical SOX9-regulated gene that suppresses TNBC growth

Abstract Background: Triple-negative breast cancers (TNBCs), which lack expression of the estrogen and progesterone receptors and the HER2 protein, are typically treated with chemotherapy and have a poor prognosis. Our previous studies have demonstrated that the SOX9 transcription factor is highly expressed in TNBC and is essential for survival and metastasis of these aggressive breast cancers. Hypothesis: CEACAM1 is a SOX9 regulated gene that regulates TNBC growth and metastasis. Material and Methods: RNA-Seq analysis was used to identify SOX9 downstream targets in MDA MB-231, MDA MB-468 or MCF-7 cells, with support from MD Anderson's genomic biostatistics core. Cells were treated with or without siRNAs or overexpression plasmids to knock down or over-express target genes. Cell growth was measured using an automated cell counting assay. Protein and mRNA levels were examined by western blotting and qRT-PCR assays. CHIP assay was used to examine direct binding of SOX9 protein on promoter of CEACAM1 gene. Several breast cancer datasets were used to analyze CEACAM1 expression in TNBCs and non-TNBCs, and the association between SOX9 and CEACAM1 expression. Significant genes are defined by using a false discovery rate (FDR) cut-off of 0.01 and log2 fold change of 2. Significant common genes are defined by using a FDR cut-off of 0.05 and log2 fold change of 1 among the cell lines. Data are presented as mean values ± SD. Statistical significance (p-values) was calculated using the Student's t-test unless otherwise indicated. Results: Upon SOX9 knockdown, 340 genes and 843 genes levels were significantly changed in MDA MB-231 and MDA MB-468 respectively. Upon SOX9 overexpression, 250 genes were regulated in MCF-7 cells. There were 38 common genes regulated by SOX9 in MDA MBA-231, MDA MB-468 cells and MCF-7 cells. Among 38 common genes, 5 genes showed positive correlation with SOX9 level (MIOX, LAMB2P1, SLCO4C1, RGCC, and PRTN3 genes). The most highly up-regulated genes upon SOX9 knockdown in TNBC cells were CEACAM1, PRSS35, CALB1, and SLC6A19. We then investigated how these SOX9 downstream genes affected TNBC cell growth in vitro. Knockdown of RGCC, PRTN3, or SLCO4C1 by siRNA reduced cell growth in TNBC cells, but had minimal effect on the growth of MCF-7 cells. Loss of CEACAM1 promoted the growth of MDA MBA-231 and MDA MB-468 cells, while overexpression of CEACAM1 decreased cell growth in TNBC cells. Bioinformatic analysis of the Curtis dataset demonstrated that TNBCs had lower CEACAM1 expression as compared to non-TNBCs. CEACAM1 was inversely correlated with SOX9 expression in the Curtis and TCGA breast cancer datasets. CHIP assays were then performed that showed that the CEACAM1 gene promoter is bound by the SOX9 transcript factor in MDA MD-231 cells. Conclusion: Our results demonstrate that CEACAM1 is a SOX9-regulated gene and is a suppressor of TNBC growth. Grant Support: These studies were supported by a Breast Cancer Research Foundation (BCRF) grant (PB). Citation Format: Yanxia Ma, William M. Tahaney, Ganiraju C. Manyam, Wenyi Wang, Abhijit Mazumdar, Powel H. Brown. CEACAM1 is a Critical SOX9-regulated gene that suppresses TNBC growth [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2411.

Abstract 460: Novel breast cancer biomarker in liquid biopsies and its immune regulatory role

Abstract The discovery of a feasible and specific biomarkers is required for early detection of breast cancer. Breast cancer secretes microvesicles (MV) in large quantities to blood circulation to communicate with distant cells such as immune cells to support tumor growth and prepare the metastatic niche. Our recent studies detected a specific peptide from the a2 isoform vacuolar ATPase (a2NTD) as a component of the MV of breast cancer cells and not from MV of normal mammary epithelial cells. a2NTD expression positively correlates with the invasiveness of breast cancer cells, modulates immune cells, and promotes tumor growth, and metastasis. Detection of a2NTD in liquid biopsies and determination of its regulatory role will offer a feasible and specific biomarker for breast cancer. We revealed that a2NTD were highly expressed in exosomes isolated from plasma of breast cancer patients (BC-Ex) in comparison to isolated exosomes from normal donors (N-Ex). BC-Ex induces the gene expression and the secretion of cancer promoting factors from PBMCs such as IL-8, MCP-1, TNF-α and MMP-9 relative to vehicle control or N-Ex. Angiogenesis assay showed that secreted factors from BC-Ex treated PBMCs promote tube formation in HUVEC cell line. In addition, treatment of whole blood from healthy volunteers with MDA MB-231 MV or recombinant a2NTD drives the neutrophil transition from high density neutrophils (HDN) to Low density neutrophils (LDN). Flow cytometrical analysis showed that LDN possess the PMN-MDSCs markers CD11b+ CD15+ CD14- CD33- HLA-DR-. In addition, a2NTD treatment was associated with decreased internal staining of Arg-1 in neutrophils and the release of Arg-1 suggesting that a2NTD reprograms neutrophils to have immunosuppressive phenotype. Together, this data shows that a2NTD can be a potential predictor of the growth and metastasis of breast cancer. Citation Format: Safaa A. Ibrahim, Valerie Riehl, Kenneth D. Beaman. Novel breast cancer biomarker in liquid biopsies and its immune regulatory role [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 460.

Abstract 2572: γ-Tocotrienol inhibition of androgen receptor (AR) expression and activation in triple negative breast cancer (TNBC) MBA-MB-231 and MDA-MB-453 cells is associated with a reduction in proliferation, migration and epithelial-to-mesenchymal transition (EMT)

Abstract Triple negative breast cancer (TNBC) is an aggressive invasive malignancy with the lowest 5-years survival rate. Gene expression profiling indicates that TNBC is a heterogeneous disease and at present, there is no targeted therapy available for treatment. Approximately one third of TNBC expressed androgen receptor (AR) and evaluation of AR positive TNBC primary tumors shows nuclear localization of AR, an indication of transcriptionally active receptors. AR levels are most abundant in the luminal AR (LAR) molecular subtype of TNBC, but other non-LAR molecular TNBC subtypes also display high levels of AR expression and activity. Previous studies have shown that AR inhibition or AR knockdown significantly reduces baseline proliferation, anchorage-independent growth, migration and invasion and increase apoptosis in different TNBC cell lines. γ-Tocotrienol is a natural isoform of vitamin E that displays potent anticancer activity. Studies were conducted to determine if γ-tocotrienol effects on AR levels and activity play a role in mediating γ-tocotrienol induced inhibition of TNBC cell proliferation, migration and epithelial-to-mesenchymal transition (EMT). In vitro studies showed that treatment with 0-12 μM γ-tocotrienol induced a dose-responsive significant decrease in TNBC MDA-MB-231 and MDA-MB-453 cell proliferation and viability. Treatment with 35 nM dihydrotestosterone (DHT) resulted in an increase of AR expression and corresponding increase in the growth of both TNBC cell lines. Treatment of MDA-MB-231 and MDA MB-453 cells with γ-tocotrienol (5 μM and 7 μM, respectively), significantly inhibited DHT-induced proliferation of both TNBC cell lines. Western blot analysis showed that γ-tocotrienol treatment significantly reduced DHT-induced cytoplasmic and nuclear AR expression in MDA-MB-453 cells, but induced only a slight and insignificant reduction in AR expression in MDA-MB-231 cells. Immunocytochemistry studies confirmed that γ-tocotrienol treatment induced a decrease in cytoplasmic and nuclear AR expression in both TNBC cell lines, but this decrease was only found to be significant in MDA-MB-453 cells. Other studies showed that γ-tocotrienol treatment significantly reduced cancer cell migration and this finding was associated with an increased expression in cytokeratin 8 (an epithelial cell biomarker) and decrease in vimentin (a mesenchymal cell biomarker) in both TNBC cell lines, and is an indication of a reversal in EMT. In summary, these results demonstrated that γ-tocotrienol treatment inhibits AR expression as well as DHT-dependent cell proliferation, migration and EMT in TNBC. These findings also suggest that AR may be a potential therapeutic target for the treatment of both LAR and non-LAR TNBC subtypes. Citation Format: Tasmin A. Sultana, Nayef Aldabaan, Paul W. Sylvester. γ-Tocotrienol inhibition of androgen receptor (AR) expression and activation in triple negative breast cancer (TNBC) MBA-MB-231 and MDA-MB-453 cells is associated with a reduction in proliferation, migration and epithelial-to-mesenchymal transition (EMT) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2572.

Hyaluronate Functionalized Multi-Wall Carbon Nanotubes Loaded with Carboplatin Enhance Cytotoxicity on Human Cancer Cell Lines.

Cancer is a major global public health problem and conventional chemotherapy has several adverse effects and deficiencies. As a valuable option for chemotherapy, nanomedicine requires novel agents to increase the effects of antineoplastic drugs in multiple cancer models. Since its discovery, carbon nanotubes (CNTs) are intensively investigated for their use as carriers in drug delivery applications. This study shows the development of a nanovector generated with commercial carbon nanotubes (cCNTs) that were oxidized (oxCNTs) and chemically functionalized with hyaluronic acid (HA) and loaded with carboplatin (CPT). The nanovector, oxCNTs–HA–CPT, was used as a treatment against HeLa and MDA–MB-231 human tumor cell lines. The potential antineoplastic impact of the fabricated nanovector was evaluated in human cervical adenocarcinoma (HeLa) and mammary adenocarcinoma (MDA-MB-231). The oxCNTs–HA–CPT nanovector demonstrate to have a specific antitumor effect in vitro. The functionalization with HA allows that nanovector bio–directed towards tumor cells, while the toxicity effect is attributed mainly to CPT in a dose-dependent manner.

A new biodegradable nano cellulose-based drug delivery system for pH-controlled delivery of curcumin

Targeted delivery and controlled release of drugs are attractive methods for avoiding the drug's leakage during blood circulation and burst release of the drug. We prepared a nano cellulose-based drug delivery system (DDS) for the effective delivery of curcumin (CUR). In the present scenario, the role of nanoparticles in fabricating the DDS is an important one and was characterized using various techniques. The drug loading capacity was high as 89.2% at pH = 8.0, and also the maximum drug release takes place at pH = 5.5. In vitro cell viability studies of DDS on MDA MB-231; breast cancer cells demonstrated its cytotoxicity towards cancer cells. The prepared DDS was also examined for apoptosis, hemocompatibility, and Chorioallantoic membrane (CAM) studies to assess its pharmaceutical field application and the investigation results recommended that it may serve as a potential device for targeted delivery and controlled release of CUR for cancer treatment.

A hydrogen peroxide responsive resorufin-based phototheranostic agent for selective treatment of cancer cells

Enhanced selectivity towards cancer cells is one of the most essential features sought in new generation photodynamic therapy (PDT) agents in order to minimize the side effects on healthy cells and to improve the efficacy of the treatment. In this direction, one promising approach is to design activatable photosensitizers, which tend to stay in an OFF state and get activated only in cancer cells with tumor-associated stimuli. Based on this idea, herein we introduced a hydrogen peroxide (H2O2) activatable iodinated resorufin (RR-1) as a red-shifted, water soluble and cancer cell selective photosensitizer. RR-1 exhibited high singlet oxygen quantum yield in aqueous solutions upon reacting with H2O2 and induced selective photocytotoxicity in colorectal (HCT-116) and triple negative breast (MDA MB-231) cancer cells, which contain high level of reactive oxygen species (ROS). Additionally, fluorescence signal of the iodo-resorufin core was restored upon cleavage of the cage unit in these cancer cells. In contrast, very low photocytotoxicity and negligible fluorescence enhancement were observed in normal fibroblast (NIH-3T3) cells. RR-1 not only marks the first example of a H2O2 activatable resorufin-based photosensitizer but also represents the first ever resorufin-based theranostic agent. We anticipate that iodo-resorufin scaffold can be easily modified with different masking units towards realization of highly selective and efficient phototheranostic agents for treatment of various cancer cells.

MELK is a downstream target of Del-1 and promotes breast cancer progression.

e12578 Background: Del-1 is a promising prognostic marker for breast cancer in our previous study. However, the downstream targets and biological effectors of Del-1 remain unclear and still untargetable in breast cancer. We performed transcriptome analysis using RNA-seq and explored the mechanism of Del-1 in regulating the progression of breast cancer to find druggable target. Methods: Total RNA was isolated using RNAiso Plus (TaKaRa, Otsu, Shiga, Japan), Libraries were prepared from total RNA using the NEBNext Ultra II Directional RNA-Seq Kit. High-throughput sequencing was performed as paired-end 100 sequencing using NovaSeq 6000 (Illumina, Inc., USA). OTSSP167(OTS167) were treated for inhibition of MELK. The effects of MELK on cell proliferation, invasion were determined using MTT, Matrigel Transwell assays. The tumoral expression of Del-1 and MELK were determined based on tissue microarrays and immunohistochemistry results from 440 early breast cancer patients. Results: To investigate Del-1 downregulation effect on breast cancer, we performed RNA-seq of Del-1 knock downed MDA-MB-231 and MCF 7-Tamoxifen resistant (TamR) cell line. Compared with si-control, MELK gene were downregulated in both knock downed cell lines. While a high Del-1 and MELK mRNA expressions were found in all the breast cancer cell lines, both expressions were significantly higher in MDA MB-231. MELK inhibitor (OTS167) treatment to breast cancer cell line MDA-MB-231 and MCF 7-TamR showed similar results as Del-1 down regulation by si-RNA. Inhibition of MELK suppressed proliferation and invasion of breast cancer cell line. Tumoral MELK expression correlate with increased aggressiveness and poor clinical outcomes in 440 breast cancer patients. Conclusions: Our results indicate that Del-1 may regulate MELK expression which has a role in breast cancer progression. In conclusion, modulation of Del-1 status by targeting MELK may be a new therapeutic strategy for breast cancer patients.

New indenopyrazole linked oxadiazole conjugates as anti-pancreatic cancer agents: Design, synthesis, in silico studies including 3D-QSAR analysis

To continue the quest of newer anticancer agents, herein a novel class of 1,4-Dihydroindenopyrazole linked oxadiazole conjugates 9(a-r) was designed, synthesized and experimented for their anti-proliferative activities against four different cancer cell lines (human) such as MDA MB-231 (breast), PANC-1 (pancreatic), MCF-7 (breast), and Caco-2 (Colorectal) by using MTT assay. Among the series compound 9h and 9 m demonstrated significant potency against the PANC-1 (human pancreatic cancer cells) with IC50 value 7.4 μM and 4.3 μM respectively. While compound 9 m was found to be equipotent to standard Gomitabine (IC50 = 4.2 μM). The detailed biological assays revealed S phase cell cycle arrest and their ability to propagate apoptosis by activating caspase 3 and 9 enzymes which was confirmed by Annexin-FITC assay and caspase assay. Moreover, docking study suggested their binding modes and interactions with caspase-3. In addition, in silico studies revealed that they exhibit good pharmacokinetics and drug likeliness properties. Furthermore, 3D-QSAR was carried out to achieve a pharmacophoric model with CoMFA (q2 = 0.631, r2 = 0.977) and CoMSIA (q2 = 0.686, r2 = 0.954) on PANC-1 cancer cells which were established, generated and validated to be reliable models for further design and optimization of newer molecules with enhanced anticancer activity.

Synthesis, biological evaluation and docking studies of 1,2,4-oxadiazole linked 5-fluorouracil derivatives as anticancer agents

Background1,2,4-oxadiazole derivatives exhibited significant anti-cancer activity when they were evaluated, against human cancer cell lines. They also showed anti-inflammatory, analgesic, diabetic, immunosuppressive, α,β3-receptor antagonist, antimicrobial, anti-helminthic, histamine-H3 and antiparasitic properties. A pyrimidine analog, 5 fluoro-uracil is a chemotherapeutic drug used for treating multiple solid malignant tumors. But its application is limited, as it has side effects like low bioavailability and high toxicity. Molecular docking is an exemplary tool, helps in identifying target and designing a drug containing high bio-availability and minimum toxicity.ResultsA set of 1,2,4-oxadiazole linked 5-fluoruracil derivatives (7a–j) were synthesized and their structures were confirmed by 1HNMR, 13CNMR and Mass spectral analysis. Further, these compounds were investigated for their anticancer activity towards a panel of four human cancer cell lines such as (MCF-7, MDA MB-231), lung cancer (A549) and prostate cancer (DU-145) by using MTT method. Among them, compounds 7a, 7b, 7c, 7d and 7i demonstrated more promising anticancer activity than standard.ConclusionSynthesized derivatives (7a–j) of 1,2,4-oxadiazole linked 5-fluorouracil and investigated for their anticancer activity towards a panel of four human cancer cell lines.

Mediator of DNA Damage Checkpoint 1 (MDC1) Is a Novel Estrogen Receptor Coregulator in Invasive Lobular Carcinoma of the Breast.

Invasive lobular carcinoma (ILC) is the most common special histologic subtype of breast cancer, and nearly all ILC tumors express estrogen receptor alpha (ER). However, clinical and laboratory data suggest ILC are strongly estrogen-driven but not equally antiestrogen-sensitive. We hypothesized ILC-specific ER coregulators mediate ER functions and antiestrogen resistance in ILC, and profiled ER-associated proteins by mass spectrometry. Three ER+ ILC cell lines (MDA MB 134VI, SUM44PE, and BCK4) were compared with ER+ invasive ductal carcinoma (IDC) line data, and we examined whether siRNA of identified proteins suppressed ER-driven proliferation in ILC cells. This identified mediator of DNA damage checkpoint 1 (MDC1), a tumor suppressor in DNA damage response (DDR), as a novel ER coregulator in ILC. We confirmed ER:MDC1 interaction was specific to ILC versus IDC cells, and found MDC1 knockdown suppressed ILC cell proliferation and tamoxifen resistance. Using RNA-sequencing, we found in ILC cells MDC1 knockdown broadly dysregulates the ER transcriptome, with ER:MDC1 target genes enriched for promoter hormone response elements. Importantly, our data are inconsistent with MDC1 tumor suppressor functions in DDR, but suggest a novel oncogenic role for MDC1 as an ER coregulator. Supporting this, in breast tumor tissue microarrays, MDC1 protein was frequently low or absent in IDC, but MDC1 loss was rare in ER+ ILC. ER:MDC1 interaction and MDC1 coregulator functions may underlie ER function in ILC and serve as targets to overcome antiestrogen resistance in ILC. IMPLICATIONS: MDC1 has novel ER coregulator activity in ILC, which may underlie ILC-specific ER functions, estrogen response, and antiestrogen resistance.

Pegylated bis-indolyl polyurethane dendrimer: Empty drug carrier with prominent anticancer activity

Blocked isocyanate-terminated, bioactive bis-indole based polyurethane dendrimers of generation G0 – G3 were subjected to urethane interchange reaction with poly(ethylene glycol) monomethyl ether; the reactions yielded corresponding PEGylated dendrimers. The structures of the PEGylated dendrimers were confirmed using spectroscopic and SEC-MALS techniques. The PDI of the polymers were found between 1.24 and 1.49 and these values were on par with 1.46 of poly(ethylene glycol) monomethyl ether used. All the PEGylated dendrimers were found to have a prominent cytotoxicity in human breast (MDA MB-231) and lung (A549) cancer cells. Based on the MTT, AO/EtBr staining and ROS assay results, PEGylated G2 and G3 dendrimers were further subjected to determination of apoptosis using protein markers; the pro-apoptotic markers BaX and caspase-3 were found up regulated and the anti-apoptotic marker Bcl-2 was down regulated. The results confirmed that the PEGylated bis-indolyl G3 polyurethane dendrimer – an empty drug carrier – itself had strong tendency to activate apoptosis type cell death in human cancer cells.

The Inhibitory Effects of Ganoderma lucium on Cell Proliferation, Apoptosis, and TNF‐α‐Induced CCL2 Release in Genetically Different Triple‐Negative Breast Cancer Cells

Breast cancer is the second most lethal form of cancer among American women, presenting strong evidence of health disparities between Whites and African Americans. Triple-negative breast cancer (TNBC), in particular, is the most aggressive subtype, affecting African American women more aggressively. Several mushrooms have been shown to have nutritional value and contain bioactive compounds with a diversity of medicinal properties. The current study investigated the effects of Ganoderma lucidum, a mushroom that has been used across Asia as a nutraceutical and herbal remedy, on TNF-α stimulated MDA-MB-231 (White) and MDA-MB-468 (African American) TNBC cells. The extract's ability in causing cell toxicity, cell proliferation, and apoptosis was examined, and its modulatory effect on the mRNA expression of genes involved in cancer progression. The results showed that G. lucidum decreased cell viability in a dose-dependent manner in concentrations of 0.75 to 4.25 mg/mL, showing similar IC50s of 1.5 and 1.4 mg/mL MDA-MB-231 and MDA-MB-468 cells, respectively. After a 96-hr of treatment, the cell proliferation rate was reduced in both cell lines. However, the extract had a higher potency in MDA-MB-468, exhibiting more anti-proliferative effects in concentrations as low as 0.125 mg/mL. Apoptosis assays demonstrated that G. lucidum extract (2.75 mg/mL) increased the number of apoptotic cells in MDA MB-231, showing 90% of the apoptotic phase's analyzed, compared to 70% in MDA-MB-468 cells. Moreover, the mushroom extract downregulated mRNA expression of the proinflammatory cytokine, CCL2, reducing expression levels to less than 10%, compared to the cells treated with TNF-α only. This study demonstrates that the extract of G. lucidum may have an anti-cancer potential by inducing cytotoxicity, reducing cell proliferation, inducing apoptotic effects, and suppressing CCL2 expression in MDA-MB-231 and MDA-MB-468 TNBC cells. Furthermore, the results reveal that the genetically diverse TNBC cells used in this study responded differently to G. lucidum treatment. These results provide more evidence that genetically different cells may respond differently to treatments, explaining the inadequate therapeutic response in African American patients with advanced TNBC compared to other races.

Resveratrol Enhances Inhibition Effects of Cisplatin on Cell Migration and Invasion and Tumor Growth in Breast Cancer MDA-MB-231 Cell Models In Vivo and In Vitro.

Triple-negative breast cancer (TNBC) is a refractory type of breast cancer that does not yet have clinically effective drugs. The aim of this study is to investigate the synergistic effects and mechanisms of resveratrol combined with cisplatin on human breast cancer MDA-MB-231 (MDA231) cell viability, migration, and invasion in vivo and in vitro. In vitro, MTS assays showed that resveratrol combined with cisplatin inhibits cell viability as a concentration-dependent manner, and produced synergistic effects (CI < 1). Transwell assay showed that the combined treatment inhibits TGF-β1-induced cell migration and invasion. Immunofluorescence assays confirmed that resveratrol upregulated E-cadherin expression and downregulated vimentin expression. Western blot assay demonstrated that resveratrol combined with cisplatin significantly reduced the expression of fibronectin, vimentin, P-AKT, P-PI3K, P-JNK, P-ERK, Sma2, and Smad3 induced by TGF-β1 (p < 0.05), and increased the expression of E-cadherin (p < 0.05), respectively. In vivo, resveratrol enhanced tumor growth inhibition and reduced body weight loss and kidney function impairment by cisplatin in MDA231 xenografts, and significantly reduced the expressions of P-AKT, P-PI3K, Smad2, Smad3, P-JNK, P-ERK, and NF-κB in tumor tissues (p < 0.05). These results indicated that resveratrol combined with cisplatin inhibits the viability of breast cancer MDA231 cells synergistically, and inhibits MDA231 cells invasion and migration through Epithelial-mesenchymal transition (EMT) approach, and resveratrol enhanced anti-tumor effect and reduced side of cisplatin in MDA231 xenografts. The mechanism may be involved in the regulations of PI3K/AKT, JNK, ERK and NF-κB expressions.

Balanced Intersystem Crossing in Iodinated Silicon-Fluoresceins Allows New Class of Red Shifted Theranostic Agents.

Iodination of the silicon-fluorescein core revealed a new class of highly cytotoxic, red-shifted and water-soluble photosensitizer (SF-I) which is also fairly emissive to serve as a theranostic agent. Singlet oxygen generation capacity of SF-I was evaluated chemically, and up to 45% singlet oxygen quantum yield was reported in aqueous solutions. SF-I was further tested in triple negative breast (MDA MB-231) and colon (HCT-116) cancer cell lines, which are known to have limited chemotherapy options as well as very poor prognosis. SF-I induced efficient singlet oxygen generation and consequent photocytotoxicity in both cell lines upon light irradiation with a negligible dark toxicity while allowing cell imaging at the same time. SF-I marks the first ever example of a silicon xanthene-based photosensitizer and holds a lot of promise as a small-molecule-based theranostic scaffold.

β-Arrestin inhibition induces autophagy, apoptosis, G0/G1 cell cycle arrest in agonist-activated V2R receptor in breast cancer cells

Non-visual arrestins (β-arrestins) are endocytic proteins that mediate agonist-activated GPCRs internalization and signaling pathways in an independent manner. The involvement of β-arrestins in cancer invasion and metastasis is increasingly reported. So, it is hypothesized that inhibition of β-arrestins may diminish the survival chances of cancer cells. This study aimed to evaluate the in vitro impact of inhibiting β-arrestins on the autophagic and/or apoptotic responsiveness of breast cancer cells. We used Barbadin to selectively inhibit β-Arr/AP2 interaction in AVP-stimulated V2R receptor of triple-negative breast cancer cells (MDA MB-231). Autophagy was assessed by the microtubule-associated protein 1 light chain 3-II (LC3II), apoptosis was measured by Annexin-V/PI staining and cell cycle distribution was investigated based upon the DNA content using flow cytometry. Barbadin reduced cell viability to 69.1% and increased the autophagy marker LC3II and its autophagic effect disappeared in cells transiently starved in Earle's balanced salt solution (EBSS). Also, Barbadin mildly enhanced the expression of P62 mRNA and arrested 63.7% of cells in G0/G1 phase. In parallel, the drug-induced apoptosis in 29.9% of cells (by AV/PI) and 27.8% of cells were trapped in sub-G1 phase. The apoptotic effect of Barbadin was enhanced when autophagy was inhibited by the PI3K inhibitor (Wortmannin). Conclusively, the data demonstrate the dual autophagic and apoptotic effects of β-βArr/AP2 inhibition in triple-negative breast cancer cells. These observations nominate β-Arrs as selective targets in breast cancer treatment.

Targeting PVT1 Exon 9 Re-Expresses Claudin 4 Protein and Inhibits Migration by Claudin-Low Triple Negative Breast Cancer Cells.

Simple SummaryTriple negative breast cancer accounts for 10–15% of all breast cancers. Specific molecular characteristics have led to the identification of six subtypes of triple negative breast cancer, with one in particular being claudin-low. PVT1, a non-protein coding gene, has been demonstrated to play an oncogenic role in various cancers. Specifically, PVT1 exon 9 has been shown to have oncogenic capability. In this study, we aimed to assess the role of PVT1 exon 9 in triple negative breast cancer cells. We have observed that siRNA targeting of PVT1 exon 9 in claudin-low triple negative breast cancer cells resulted in re-expression of claudin 4 protein, and inhibition of migration. These findings indicate that PVT1 exon 9 regulates claudin 4 expression and migration in triple negative breast cancer cells.PVT1 is a long non-coding RNA transcribed from a gene located at the 8q24 chromosomal region that has been implicated in multiple cancers including breast cancer (BC). Amplification of the 8q24 chromosomal region is a common event in BC and is associated with poor clinical outcomes. Claudin–low (CL) triple negative breast cancer (TNBC) is a subtype of BC with a particularly dismal outcome. We assessed PVT1 exon 9 expression in the T47D estrogen receptor positive BC cell line, and in the MDA MB 468 and MDA MB 231 TNBC cell lines, followed by the assessment of the expression of claudins 1, 3, 4 and 7, in MDA MB 468 and MDA MB 231 (TNBC) cells. We found that MDA MB 231 TNBC cells significantly express less claudin 1, 3, 4, and 7 than MDA MB 468 TNBC cells. PVT1 exon 9 is significantly upregulated in MDA MB 231 CL TNBC cells, and significantly downregulated in MDA MB 468 claudin high (CH) TNBC cells, in comparison to T47D estrogen receptor positive BC cells. We then analyzed the functional consequences of siRNA targeting of PVT1 exon 9 expression in the MDA MB 231 CL TNBC cells. Notably, siRNA targeting of PVT1 exon 9 expression in the MDA MB 231 CL TNBC cells led to a significant reduction in migration and the re-expression of claudin 4. Taken together, our data indicate that PVT1 exon 9 regulates claudin 4 expression and migration in CL TNBC cells, and may have clinical implications in CL TNBC.