Target For Breast Cancer Therapy Research Articles

Identification of Biomarkers and Functional Modules from Genomic Data in Stage-wise Breast Cancer

Background: Breast cancer is the most common cancer in women across the world, with high incidence and mortality rates. Being a heterogeneous disease, gene expression profiling based analysis plays a significant role in understanding breast cancer. Since expression patterns of patients belonging to the same stage of breast cancer vary considerably, an integrated stage-wise analysis involving multiple samples is expected to give more comprehensive results and understanding of breast cancer. Objective: The objective of this study is to detect functionally significant modules from gene coexpression network of cancerous tissues and to extract prognostic genes related to multiple stages of breast cancer. Methods: To achieve this, a multiplex framework is modelled to map the multiple stages of breast cancer, which is followed by a modularity optimization method to identify functional modules from it. These functional modules are found to enrich many Gene Ontology terms significantly that are associated with cancer. Result and Discussion: Predictive biomarkers are identified based on differential expression analysis of multiple stages of breast cancer. Conclusion: Our analysis identified 13 stage-I specific genes, 12 stage-II specific genes, and 42 stage-III specific genes that are significantly regulated and could be promising targets of breast cancer therapy. That apart, we could identify 29, 18 and 26 lncRNAs specific to stage I, stage II and stage III respectively.

Application of bacterial directed enzyme prodrug therapy as a targeted chemotherapy approach in a mouse model of breast cancer

Cancer is the second leading cause of death in the world. Some of the usual cancer treatments include surgery, chemotherapy, and radiotherapy. However, due to low efficacy and side effects of these treatments, novel targeted therapeutic methods are needed. One of the common drawbacks of cancer chemotherapy is off-target toxicity. In order to overcome this problem, many investigations have been conducted. One of the new targeted therapy methods known as bacterial directed enzyme-prodrug therapy (BDEPT) employs bacteria as enzyme carriers to convert a pro-drug to a drug specifically within the tumor site. In the present study, we used Escherichia coli DH5α carrying luxCDABE gene cluster and overexpressing β-glucuronidase for luminescent emission and enzyme expression, respectively. Enzyme expression can lead to the conversion of glycyrrhizic acid as a prodrug to glycyrrhetinic acid, a potent anti-cancer agent. DH5α-lux/βG was characterized and its stability was also evaluated. Bacteria colonization in the tumor site was measured by tissue homogenate preparation and colony counting method. Histopathological studies on the liver, spleen, and tumor were also conducted. According to the results, co-treatment of 4T1, a highly metastatic mouse breast cancer cell line, with GL and DH5α-lux/βG could significantly decrease the IC50 values. Moreover, increased number of bacteria could lead to a dramatic drop in IC50 value. Specific colonization of DH5α-lux/βG was observed in the tumor site compared with other tissues (p< 0.0001). Moreover, the biocompatibility evaluation proved that DH5α-lux/βG had no adverse effects on normal tissues. Furthermore, concurrent usage of GL and bacteria in the treatment of induced 4T1 tumors in BALB/c mice significantly delayed tumor growth (p<0.001) during 16 days of investigation. Based on these findings, BDEPT might be useful for targeted breast cancer therapy, although further investigations are required to confirm this.

RNA-binding protein SAMD4A inhibits breast tumor angiogenesis by modulating the balance of angiogenesis program.

Tumor‐induced angiogenesis is important for further progression of solid tumors. The initiation of tumor angiogenesis is dictated by a shift in the balance between proangiogenic and antiangiogenic gene expression programs. However, the potential mechanism controlling the expression of angiogenesis‐related genes in the tumor cells, especially the process mediated by RNA‐binding protein (RBP) remains unclear. SAMD4A is a conserved RBP across fly to mammals, and is believed to play an important role in controlling gene translation and stability. In this study, we identified the potential role of SAMD4A in modulating angiogenesis‐related gene expression and tumor progression in breast cancer. SAMD4A expression was repressed in breast cancer tissues and cells and low SAMD4A expression in human breast tumor samples was strongly associated with poor survival of patients. Overexpression of SAMD4A inhibited breast tumor angiogenesis and caner progression, whereas knockdown of SAMD4A demonstrated a reversed effect. Mechanistically, SAMD4A was found to specifically destabilize the proangiogenic gene transcripts, including C‐X‐C motif chemokine ligand 5 (CXCL5), endoglin (ENG), interleukin 1β (IL1β), and angiopoietin 1 (ANGPT1), by directly interacting with the stem‐loop structure in the 3′ untranslated region (3′UTR) of these mRNAs through its sterile alpha motif (SAM) domain, resulting in the imbalance of angiogenic genes expression. Collectively, our results suggest that SAMD4A is a novel breast tumor suppressor that inhibits tumor angiogenesis by specifically downregulating the expression of proangiogenic genes, which might be a potential antiangiogenic target for breast cancer therapy.

Molecular modeling studies of [4-(3H-benzoimidazol-5-yl)-pyrimidin-2-yl]-amine-based CDK4 inhibitors.

Aim: CDK4 is a promising target for breast cancer therapy. This study aimed to explore the structure-activity relationship of CDK4 inhibitor abemaciclib analogs and design potent CDK4 inhibitors for breast cancer treatment. Methods & results: A faithful 3D quantitative structure-activity relationship model was established by molecular docking, comparative molecular field analysis and comparative molecular similarity index analysis based on 56 abemaciclib analogs. Molecular dynamics simulation studies revealed the key residues of the interaction between CDK4 and inhibitors. Four novel inhibitors with satisfactory predicted binding affinity to CDK4 were designed. Conclusion: The 3D quantitative structure-activity relationship and molecular dynamics simulation studies provide valuable insight into the development of novel CDK4 inhibitors.

Abstract 1239: Putative Bax activators GL0385 and GL0388 for targeted breast cancer therapy

Abstract Breast cancer is one of the leading causes of cancer-related death in American women and the most common cancer in women with more than 270,000 estimated new cases in 2020 in the US. This is about 30% of the estimated total cancer patients in American women and therefore a major threat to the society with an urgent need of advanced treatment regimens. Especially the subgroup of estrogen receptor (ER)-negative breast cancers (ENBC), which are approximately one quarter to a third of all breast cancer, are lacking efficient treatment methods. Particularly dangerous is triple-negative breast cancer (TNBC), a subtype of ENBC with a high metastatic potential, since 90% of cancer-related deaths are due to metastasis. However, an effective drug for ENBC/TNCB treatment remains to be developed. The pro-apoptotic protein Bax was shown to be downregulated in most cancers. As a result, the balance between Bax and its antagonist Bcl-2 gets disturbed which leads to dysfunctional apoptotic signaling in favor of cancer cell survival. Upon activation, Bax is translocated from the cytosol to the mitochondria where it binds to the outer mitochondrial membrane. This leads to increased permeability of the mitochondrial membrane and a release of pro-apoptosis related molecules such as cytochrome C and others. Hence, drug discovery for Bax activation is a promising approach for developing novel cancer therapies. The small molecules GL0385 and GL0388 were identified from our progenitor molecules including small-molecule Bax activator (SMBA1), CYD-2-11, and CYD-4-61. The CYD compounds specifically target the Ser184 residue of Bax and have shown apoptosis-inducing effects both in vitro and in vivo. These lead Bax activators provided proof-of-concept studies while further optimization is needed to mitigate potential toxicity, leading to the discovery of advanced lead molecules GL0385 and GL0388. Treatment with either GL0385 or GL0388 resulted in significantly decreased cell proliferation in MDA-MB-231, MDA-MB-468, BT549, MDA-MB-453, MCF-7, and MDA-MB-361 cells. Additionally, MDA-MB-231 cells treated with GL0385 or GL0388 showed reduced migration and invasion, compared to control cells. Western blot analysis confirmed increased protein levels of Bax, cleaved PARP, cleaved caspase 3, and cytochrome C. These results show that GL0385 and GL388 have a significant impact on cancer cell proliferation and cellular motility which are main attributes of metastasizing cells. Additionally, increased expression of apoptosis markers indicates that these compounds may be beneficial to regain the anti-apoptotic/pro-apoptotic balance in breast cancer cells. Therefore, GL0385 and GL0388 are promising new advanced lead compounds towards the development of effective therapies for breast cancers and other cancers. Further investigation is warranted to fully explore their anti-cancer potential and mechanisms of action. Citation Format: Doerte R. Fricke, Hyejin Kim, Gang Liu, Haiying Chen, Jia Zhou, Qiang Shen. Putative Bax activators GL0385 and GL0388 for targeted breast cancer therapy [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 1239.

Photoluminescent folic acid functionalized biocompatible and stimuli-responsive nanostructured polymer brushes for targeted and controlled delivery of doxorubicin

In this work, the new photoluminescent and biocompatible folic acid (FA) conjugated stimuli-responsive nanostructured polymer brushes were designed, fabricated, and then evaluated as a doxorubicin (DOX) carrier. In this regard at first, graphene quantum dots (GQDs) were prepared through citric acid (CA) pyrolysis. In the following, the functionalization of GQDs with 3-aminopropyltriethoxysilane (APTS) and then α-bromoisobutyryl bromide (BIB) obtained the GQDs-Br, which have the ability to acts as a nano-based initiator. Subsequently, the N-isopropylacrylamide (NIPAM) and acrylated β-cyclodextrin (Ac-β-CD) monomers grown from the GQDs-Br surface as a block copolymer (GQDs-PNIPAM-co-PβCD) via atom transfer radical polymerization (ATRP) technique. Eventually, the conjugation with FA achieved the photoluminescent nanostructure copolymer brushes with targeted drug delivery capability (GQDs-PNIPAM-co-PβCD@FA). The synthesized samples were characterized through various characterization techniques. DOX was loaded via several possible interactions on GQDs-PNIPAM-co-PβCD@FA. The in vitro DOX release test exhibited 12% of DOX release in the simulated environment with the physiological condition while 43% of DOX released in the simulated cancer cells condition; confirm the pH sensitivity of the carrier. The in vitro biological tests displayed good stability, biodegradability, and biocompatibility of the prepared nanostructure. As well as, the higher efficiency of DOX@GQDs-PNIPAM-co-PβCD@FA in MDA-MB 231 cells killing compared to A 549 cells revealed the targeted drug delivery. The results demonstrated that the fabricated nanosystem could be a hopeful candidate for targeted breast cancer therapy with the inherent potential of imaging.

DDR1 Affects Metabolic Reprogramming in Breast Cancer Cells by Cross-Talking to the Insulin/IGF System.

The insulin receptor isoform A (IR-A), a dual receptor for insulin and IGF2, plays a role in breast cancer (BC) progression and metabolic reprogramming. Notably, discoidin domain receptor 1 (DDR1), a collagen receptor often dysregulated in cancer, is involved in a functional crosstalk and feed forward loop with both the IR-A and the insulin like growth factor receptor 1 (IGF1R). Here, we aimed at investigating whether DDR1 might affect BC cell metabolism by modulating the IGF1R and/or the IR. To this aim, we generated MCF7 BC cells engineered to stably overexpress either IGF2 (MCF7/IGF2) or the IR-A (MCF7/IR-A). In both cell models, we observed that DDR1 silencing induced a significant decrease of total ATP production, particularly affecting the rate of mitochondrial ATP production. We also observed the downregulation of key molecules implicated in both glycolysis and oxidative phosphorylation. These metabolic changes were not modulated by DDR1 binding to collagen and occurred in part in the absence of IR/IGF1R phosphorylation. DDR1 silencing was ineffective in MCF7 knocked out for DDR1. Taken together, these results indicate that DDR1, acting in part independently of IR/IGF1R stimulation, might work as a novel regulator of BC metabolism and should be considered as putative target for therapy in BC.

Trastuzumab-induced cardiotoxicity: a review of clinical risk factors, pharmacologic prevention, and cardiotoxicity of other HER2-directed therapies.

Despite great success as a targeted breast cancer therapy, trastuzumab use may be complicated by heart failure and loss of left ventricular contractile function. This review summarizes the risk factors, imaging, and prevention of cardiotoxicity associated with trastuzumab and other HER2-targeted therapies. Cardiovascular disease risk factors, advanced age, and previous anthracycline treatment predispose to trastuzumab-induced cardiotoxicity (TIC), with anthracycline exposure being the most significant risk factor. Cardiac biomarkers such as troponins and pro-BNP and imaging assessments such as echocardiogram before and during trastuzumab therapy may help in early identification of TIC. Initiation of beta-adrenergic antagonists and angiotensin converting enzyme inhibitors may prevent TIC. Cardiotoxicity rates of other HER2-targeted treatments, such as pertuzumab, T-DM1, lapatinib, neratinib, tucatinib, trastuzumab deruxtecan, and margetuximab, appear to be significantly lower as reported in the pivotal trials which led to their approval. Risk assessment for TIC should include cardiac imaging assessment and should incorporate prior anthracycline use, the strongest risk factor for TIC. Screening and prediction of cardiotoxicity, referral to a cardio-oncology specialist, and initiation of effective prophylactic therapy may all improve prognosis in patients receiving HER2-directed therapy. Beta blockers and ACE inhibitors appear to mitigate risk of TIC. Anthracycline-free regimens have been proven to be efficacious in early HER2-positive breast cancer and should now be considered the standard of care for early HER2-positive breast cancer. Newer HER2-directed therapies appear to have significantly lower cardiotoxicity compared to trastuzumab, but trials are needed in patients who have experienced TIC and patients with pre-existing cardiac dysfunction.

Hetero-Trifunctional Malonate-Based Nanotheranostic System for Targeted Breast Cancer Therapy.

Designing multifunctional linkers is crucial for tricomponent theranostic targeted nanomedicine development as they are essential to enrich polymeric systems with different functional moieties. Herein, we have obtained a hetero-trifunctional linker from malonic acid and demonstrated its implication as an amphiphilic targeted nanotheranostic system (CB DX UN PG FL). We synthesized it with varying hydrophilic segment to fine-tune the hydrophobic/hydrophilic ratio to optimize its self-assembly. pH-responsive hydrazone-linked doxorubicin was conjugated to the backbone (UN PG FL) containing folate as a targeting ligand. Cobalt carbonyl complex was used for T2-weighted magnetic resonance imaging (MRI). Electron micrographs of optimized molecule CB DX UN PG(4kDa)FL in an aqueous system have demonstrated about 50-60 nm-sized uniform micelles. The relaxivity study and the one-dimensional (1D) imaging experiments clearly revealed the effect of the nanotheranostics system on transverse relaxation (T2) of water molecules, which validated the system as a T2-weighted MRI contrast agent. The detailed in vitro biological studies validated the targeted delivery and anticancer potential of CB DX UN PG(4kDa)FL. Combining the data on transverse relaxation, folate mediated uptake, and anticancer activity, the designed molecule will have a significant impact on the development of targeted theranostic.

PPARgamma: A Potential Intrinsic and Extrinsic Molecular Target for Breast Cancer Therapy.

Over the last decades, the breast tumor microenvironment (TME) has been increasingly recognized as a key player in tumor development and progression and as a promising prognostic and therapeutic target for breast cancer patients. The breast TME, representing a complex network of cellular signaling—deriving from different stromal cell types as well as extracellular matrix components, extracellular vesicles, and soluble growth factors—establishes a crosstalk with cancer cells sustaining tumor progression. A significant emphasis derives from the tumor surrounding inflammation responsible for the failure of the immune system to effectively restrain breast cancer growth. Thus, effective therapeutic strategies require a deeper understanding of the interplay between tumor and stroma, aimed at targeting both the intrinsic neoplastic cells and the extrinsic surrounding stroma. In this scenario, peroxisome proliferator-activated receptor (PPAR) γ, primarily known as a metabolic regulator, emerged as a potential target for breast cancer treatment since it functions in breast cancer cells and several components of the breast TME. In particular, the activation of PPARγ by natural and synthetic ligands inhibits breast cancer cell growth, motility, and invasiveness. Moreover, activated PPARγ may educate altered stromal cells, counteracting the pro-inflammatory milieu that drive breast cancer progression. Interestingly, using Kaplan–Meier survival curves, PPARγ also emerges as a prognostically favorable factor in breast cancer patients. In this perspective, we briefly discuss the mechanisms by which PPARγ is implicated in tumor biology as well as in the complex regulatory networks within the breast TME. This may help to profile approaches that provide a simultaneous inhibition of epithelial cells and TME components, offering a more efficient way to treat breast cancer.

SERCA Inhibition as a Potential Therapeutic Target for Breast Cancer

Chemotherapy is both a palliative treatment for many cancers and adjuvant treatment before, during, or after local treatment (surgery and/or radiation therapy) in single or combination regimens. Despite current treatments, approximately 1 in 39 women (3%) still die from breast cancer. A major complication with systemic therapy is drug resistance which limits the efficacy of clinical chemotherapy. Hence, current research aims to uncover novel targets for breast cancer therapy. Various studies have shown altered calcium signaling in breast cancer cells, therefore, calcium modulators may be potential therapeutic targets. Studies have also shown that Thapsigargin (TG) and cyclopiazonic acid (CPZ), two potent and specific inhibitors of the sarcoplasmic reticulum (SR) Ca2+-ATPase (SERCA), can impair cancer cell growth. However, TG and CPZ also impair non-malignant cells, which results in significant toxicity, thus preventing use in chemotherapy. Using spectrometry UV-visible measurements to assess calcium loading and ATPase activity in SR microsomes, our lab has found that various drugs which display cell protective effects in ischemia also inhibit SERCA. They include novel benzothiazepines (BZTs; K201, CGP37157, PH00095) and have shown to inhibit SERCA in a calcium dependent mechanism. They decreased SR uptake when cytosolic Ca2+ levels ([Ca2+]c) are low, similar to competitive inhibition of Ca2+ uptake, which produces mild store depletion. Contrarily, TG and CPZ block Ca2+ uptake at all [Ca2+]c and largely deplete SR stores. Using various SERCA inhibitors, we sought out to determine their effects on breast cancer cell lines of different subtypes. MTS assay studies show that TG and CPZ significantly reduce cell viability in MCF7 and MCF10A cell lines while having no significant effects on triple negative breast cancer (TNBC) cell line MDAMB231. Preliminary studies also show no significant effect by TG on BT20 cells, another TNBC cell line. BZT K201 also significantly reduced cell viability in MCF7 cells but not MDAMB231. Immunoblot shows MCF7 cells have significantly higher SERCA2 expression than MDAMB231. We observe no significant differences in plasma membrane calcium channel ATPase (PMCA) protein expression. Preliminary RT-PCR studies estimate MCF7 cells have a higher fold change in SERCA genes. Thus, targeting SERCA may serve as a potential therapeutic target for breast cancer. Here, we find that SERCA inhibitors TG, CPZ, and BZT K201 reduce cell viability in MCF7 cells. Still, these studies indicate that SERCA inhibition may only be efficacious in certain breast cancer cell types which do not express a TNBC phenotype. TNBC cell lines (MDAMB231, BT20) are not significantly affected by SERCA inhibition, which may be due to higher dependence for signaling on plasmalemma calcium channels and transporters. Additional studies are required to confirm the expression profiles of calcium transporters among cell lines, including those in the plasmalemma (PMCA, calcium channels), which may help to understand if alternative sources of Ca2+ for intracellular signaling make TNBC cell lines more resistant to SERCA inhibitors.

Preclinical Advances in Theranostics for the Different Molecular Subtypes of Breast Cancer.

Breast cancer is the most common cancer in women worldwide. The heterogeneity of breast cancer and drug resistance to therapies make the diagnosis and treatment difficult. Molecular imaging methods with positron emission tomography (PET) and single-photon emission tomography (SPECT) provide useful tools to diagnose, predict, and monitor the response of therapy, contributing to precision medicine for breast cancer patients. Recently, many efforts have been made to find new targets for breast cancer therapy to overcome resistance to standard of care treatments, giving rise to new therapeutic agents to offer more options for patients with breast cancer. The combination of diagnostic and therapeutic strategies forms the foundation of theranostics. Some of these theranostic agents exhibit high potential to be translated to clinic. In this review, we highlight the most recent advances in theranostics of the different molecular subtypes of breast cancer in preclinical studies.

Polymorphism on human aromatase affects protein dynamics and substrate binding: spectroscopic evidence

Human aromatase is a member of the cytochrome P450 superfamily, involved in steroid hormones biosynthesis. In particular, it converts androgen into estrogens being therefore responsible for the correct sex steroids balance. Due to its capacity in producing estrogens it has also been considered as a promising target for breast cancer therapy. Two single-nucleotide polymorphisms (R264C and R264H) have been shown to alter aromatase activity and they have been associated to an increased or decreased risk for estrogen-dependent pathologies. Here, the effect of these mutations on the protein dynamics is investigated by UV/FTIR and time resolved fluorescence spectroscopy. H/D exchange rates were measured by FTIR for the three proteins in the ligand-free, substrate- and inhibitor-bound forms and the data indicate that the wild-type enzyme undergoes a conformational change leading to a more compact tertiary structure upon substrate or inhibitor binding. Indeed, the H/D exchange rates are decreased when a ligand is present. In the variants, the exchange rates in the ligand-free and –bound forms are similar, indicating that a structural change is lacking, despite the single amino acid substitution is located in the peripheral shell of the protein molecule. Moreover, the fluorescence lifetimes data show that the quenching effect on tryptophan-224 observed upon ligand binding in the wild-type, is absent in both variants. Since this residue is located in the catalytic pocket, these findings suggest that substrate entrance and/or retention in the active site is partially compromised in both mutants. A contact network analysis demonstrates that the protein structure is organized in two main clusters, whose connectivity is altered by ligand binding, especially in correspondence of helix-G, where the amino acid substitutions occur. Our findings demonstrate that SNPs resulting in mutations on aromatase surface modify the protein flexibility that is required for substrate binding and catalysis. The cluster analysis provides a rationale for such effect, suggesting helix G as a possible target for aromatase inhibition.

MiR-1224-3p Promotes Breast Cancer Cell Proliferation and Migration through PGM5-Mediated Aerobic Glycolysis.

Metabolic reprogramming of aerobic glycolysis is a hallmark of cancer cells. Regulators of aerobic glycolysis have become targets for cancer diagnosis and therapy. However, the regulators of aerobic glycolysis in breast cancer development have not been well elucidated. Here, we show that the phosphoglucomutase (PGM) family member PGM5 promotes conversion of glucose-1-phosphate (G1P) into glucose-6-phosphate (G6P) and inhibits breast cancer cell proliferation and migration through regulating aerobic glycolysis. In breast cancer patients, PGM5 is significantly downregulated, and its low expression is a predictor of poor prognosis. MicroRNA-1224-3p (miR-1224-3p) inhibits the PGM5 level through directly targeting its 3'-untranslated region and suppresses PGM5-mediated breast cancer cell proliferation, migration, and glycolytic function. Moreover, the miR-1224-3p/PGM5 axis regulates the expression of cell cycle- and apoptosis-related genes and the markers of epithelial-mesenchymal transition (EMT), a process involved in migration and metastasis of cancer cells. Taken together, our results indicate that miR-1224-3p/PGM5 axis plays important roles in breast cancer cell proliferation, migration, and aerobic glycolysis and may be a potential target for breast cancer therapy.

The modulation of PD-L1 induced by the oncogenic HBXIP for breast cancer growth.

Programmed death ligand-1 (PD-L1)/PD-1 checkpoint extensively serves as a central mediator of immunosuppression. A tumor-promoting role for abundant PD-L1 in several cancers is revealed. However, the importance of PD-L1 and how the PD-L1 expression is controlled in breast cancer remains obscure. Here, the mechanisms of controlling PD-L1 at the transcription and protein acetylation levels in promoting breast cancer growth are presented. Overexpressed PD-L1 accelerates breast cancer growth in vitro and in vivo. RNA-seq uncovers that PD-L1 can induce some target genes affecting many cellular processes, especially cancer development. In clinical breast cancer tissues and cells, PD-L1 and HBXIP are both increased, and their expressions are positively correlated. Mechanistic exploration identifies that HBXIP stimulates the transcription of PD-L1 through co-activating ETS2. Specifically, HBXIP induces PD-L1 acetylation at K270 site through interacting with acetyltransferase p300, leading to the stability of PD-L1 protein. Functionally, depletion of HBXIP attenuates PD-L1-accelerated breast tumor growth. Aspirin alleviates breast cancer via targeting PD-L1 and HBXIP. Collectively, the findings display new light into the mechanisms of controlling tumor PD-L1 and broaden the utility for PD-L1 as a target in breast cancer therapy.

Reprogramming Cancer Stem-like Cells with Nanoforskolin Enhances the Efficacy of Paclitaxel in Targeting Breast Cancer.

Cancer stem-like cells (CSCs) have emerged as an important target for breast cancer therapy owing to their self-renewability, proliferation, and elevated chemoresistance properties. Here, we present a strategy of eliminating CSCs by differentiation therapy where "forced differentiation" reprograms CSCs so that they lose their intrinsic properties and become susceptible for conventional chemotherapeutic drugs. In this study, we report that a conventional chemotherapeutic paclitaxel enhances the stemness of CSCs, while a phytochemical forskolin being essentially nontoxic to CSCs possesses the intrinsic ability to reprogram them. To achieve simultaneous targeting of CSCs and bulk tumor cells, we used a co-delivery system where liquid crystal nanoparticles (LCN) were co-encapsulated with both paclitaxel and forskolin. LCN showed higher uptake, retention, and penetration potential in CSCs overcoming their high drug efflux property. Moreover, LCN improved the pharmacokinetic parameters of forskolin, which otherwise had very low retention and bioavailability. Forskolin-loaded LCN forced CSCs to exit from their mesenchymal state, which reduced their stemness and chemosensitized them while inhibiting E-cadherin-mediated survival and tumor-initiating potential as well as reversing paclitaxel-induced stemness. We further showed that upon administration of paclitaxel and forskolin co-loaded LCN to an orthotropic xenograft mouse model, the nanomedicine showed enhanced passive tumor targeting capability with very potent antitumor activity that eradicated small solid tumor in a single dose and showed no sign of tumor relapse or systemic toxicity over a long period. Overall, these findings give a proof of concept that co-delivery of forskolin and paclitaxel in a single nanoformulation can achieve overall tumor targeting where forskolin can efficiently reprogram/differentiate CSCs and paclitaxel can induce cytotoxicity in both differentiated CSCs and bulk tumor cells simultaneously. Hence, this study can provide a nanoformulation that can offer an efficient strategy for cancer therapy.

Correlation of CD44 and CD24 expression with the positive response after neoadjuvant chemotherapy in stage IIIB breast cancer patient at Dr. Saiful Anwar Hospital, Malang, Indonesia

Background: Breast cancer is a type of cancer due to abnormal cell growth of breast tissue. CD44 and CD24 is a potential target in breast cancer therapy. This study aims to evaluate the responsiveness of stage 3 breast cancer to chemotherapy by measuring the expression levels of CD44 and CD24 moleculesMethods: We conducted an observational study with pre-and –post-intervention or test research types. This study was performed on 49 Luminal Stadium IIIB subtype breast cancer patients who received 3 series of neoadjuvant chemotherapy at RSUD dr. Saiful Anwar Malang, immunohistochemical examination, and painting of tissue specimens from the biopsy results. Data were analyzed using SPSS version 20 for Windows.Results: Based on the Paired t-test and discriminant analysis, there were no significant differences between CD44 and CD24 expression before and after chemotherapy (p=0.501 and p=0.097, respectively). Therefore, the results of the study prompt that the expression of CD44 and CD24 could not be a predictor of the chemotherapy response.Conclusion: There are different expressions of CD44 and CD44 in primary breast cancer before and after chemotherapy, but no significant difference was found.

Screenning Bioactive Compounds from Allium sativum as HER2 Inhibitors Targeting Breast Cancer by Docking Methods

Screenning Bioactive Compounds from Allium sativum as HER2 Inhibitors Targeting Breast Cancer by Docking Methods

Circular RNA RHOT1 promotes progression and inhibits ferroptosis via mir-106a-5p/STAT3 axis in breast cancer.

To explore the effect of circRHOT1 on breast cancer progression and the underlying mechanism. Significantly, our data revealed that the depletion of circRHOT1 was able to repress the proliferation and induce the apoptosis of breast cancer cells. CircRHOT1 knockdown could remarkably inhibit the invasion and migration in the breast cancer cells. Meanwhile, the depletion of circRHOT1 enhanced the erastin-induced inhibition effect on cell growth of breast cancer cells. The circRHOT1 knockdown notably increased the levels of reactive oxygen species (ROS), iron, and Fe2+ in breast cancer cells. Mechanically, circRHOT1 was able to sponge microRNA-106a-5p (miR-106a-5p) and inhibited ferroptosis by down-regulating miR-106a-5p in breast cancer cells. Besides, miR-106a-5p induced ferroptosis by targeting signal transducer and activator of transcription 3 (STAT3) in the system. Moreover, the overexpression of STAT3 and miR-106a-5p inhibitor could reverse circRHOT1 knockdown-mediated breast cancer progression. Functionally, circRHOT1 promoted the tumor growth of breast cancer in vivo. In conclusion, we discovered that circRHOT1 contributed to malignant progression and attenuated ferroptosis in breast cancer by the miR-106a-5p/STAT3 axis. Our finding provides new insights into the mechanism by which circRHOT1 promotes the development of breast cancer. CircRHOT1 and miR-106a-5p may serve as potential targets for breast cancer therapy.

In vitro breast cancer targeting using Trastuzumab-conjugated mesoporous silica nanoparticles: Towards the new strategy for decreasing size and high drug loading capacity for drug delivery purposes in MSN synthesis

Abstract In the present study, an efficient protocol was introduced for synthesis of biocompatible mesoporous silica nanoparticles (MSN) with an adequate size and high drug loading capacity. Herein, the tri-ethanolamine, TEA, dominantly controlled the pH of solution in addition to regulate nanoparticle sizes via complexing with ortho silicate functional group. Furthermore, ammonium nitrate as a weak acid was used for micellar template extraction and the results were compared with a common salt such as sodium chloride. The obtained results of BET analysis showed ammonium nitrate led to creation of pore sizes with 3.2 nm and enhanced specific surface area with 563 m2/g which were higher than NaCl route. In the next step, the surfaces of MSNs were functionalized with particular compounds, (3- Aminopropyl) tri-ethoxysilane, APTES, applied for amine functionalization whereas 1-Ethyl-3-(3- dimethylaminopropyl)-carbodiimide/N-hydroxysuccinimide, EDC/NHS, as cross link agent was used for Trastuzumab modification of silica nanoparticles which were subsequently loaded with doxorubicin for studying the targeted breast cancer therapy. Moreover, fluorescein dye was optimized on the surface modified nanoparticles. The molecular fluorescence imaging was used to confirm the significant attachments of our surface modified MSNs to plasma membrane of breast cancer cell lines (HER2 overexpressed SKBR3 cell lines). Furthermore, drug loading capacity of the presented nano-carriers was calculated and shown to be 57.40% for doxorubicin suggesting its priority in the biological application comparing to other reported ones. Finally, quantum chemical study at B3lyp/6–311++g** level of theory was performed to reveal the pH-triggered release of doxorubicin loaded on these nanoparticles which the obtained results were in agreement with experimental evidences.