Expression of HER-2 in MCF-7 breast cancer cells modulates anti-apoptotic proteins Survivin and Bcl-2 via the extracellular signal-related kinase (ERK) and phosphoinositide-3 kinase (PI3K) signalling pathways

Secondary Analysis of Human Bulk RNA-Seq Dataset Suggests Potential Mechanisms for Letrozole Resistance in Estrogen-Positive (ER+) Breast Cancer

Estrogen receptor-positive (ER+) breast cancer is common among postmenopausal women and is frequently treated with Letrozole, which inhibits aromatase from synthesizing estrogen from androgens. Decreased estrogen slows the growth of tumors and can be an effective treatment. The increase in Letrozole resistance poses a unique problem for patients. To better understand the underlying molecular mechanism(s) of Letrozole resistance, we reanalyzed transcriptomic data by comparing individuals who responded to Letrozole therapy (responders) to those who were resistant to treatment (non-responders). We identified SOX11 and S100A9 as two significant differentially expressed genes (DEGs) between these patient cohorts, with "PLK1 signaling events" being the most significant signaling pathway. We also identified PRDX4 and E2F8 gene products as being the top mechanistic transcriptional markers for ER+ treatment resistance. Many of the significant DEGs that we identified play a known role in ER+ breast cancer or other types of cancer, which partially validate our results. Several of the gene products we identified are novel in the context of ER+ breast cancer. Many of the genes that we identified warrant further research to elucidate the more specific molecular mechanisms of Letrozole resistance in this patient population and could potentially be used as prognostic markers with further wet lab validation. We anticipate that these findings could contribute to improved detection and therapeutic outcomes in aromatase-resistant ER+ breast cancer patients.

Fatty acid modification of casein bioactive peptides nano-assemblies, synthesis, characterization and anticarcinogenic effect

In this study, the nano-assemblies of bovine casein hydrolyzed peptides (HP) modified by fatty acids with various alkyl chain lengths (C8, C10, C12 and C14) were synthesized. The physicochemical properties of HP-C8-HP-C14 nano-assemblies were characterized using spectra, laser particle size analyzer, contact angle meter, scanning electron microscope (SEM) and cryo-transmission electron microscope (Cryo-TEM). HP-C8 and HP-C10 self-assembled into a hollow cube cage with an average size of ~500 nm, and the assembly of HP-C12 showed a flower-shaped morphology with more dispersed behavior, and droplet size was observed as ~20 nm. The in vitro cytotoxicity against human breast cancer cells MCF-7 was tested using CCK-8 assay and flow cytometry analysis. HP-C12 showed the highest cytotoxicity for MCF-7 cells with an inhibition rate of 66.03 % ± 0.35 % with an IC50 value of 7.4 μM among HP-Cn. HP-C8, HP-C10 and HP-C12 significantly affected on the migration, invasion and apoptosis of MCF-7 cells. The apoptosis mechanism may depend on the upregulation of anti-apoptotic protein Bcl-2 as well as pro-apoptotic proteins Bax and caspase-8. The dead MCF-7 cells were analyzed with UHPLC-MS/MS using untargeted metabolomics, revealing key metabolic pathways.

The mechanism and treatment of targeted anti-tumour drugs induced cardiotoxicity

As the intensive anti-tumour therapy and combination of multiple anti-tumour drugs, cardiotoxicity events caused by anti-tumour drugs have also increased significantly, and the incidence of cardiotoxicity also increased with survival time. Different types of anti-tumour drugs could cause all kinds of cardiotoxicity which increase the difficulties in treatment and even live threatening. In this review, we concentrated in the targeted anti-tumour drugs such as human epidermal growth factor receptor-2 (HER2) inhibitors, tyrosine kinase inhibitors (TKIs), immune checkpoint inhibitors (ICIs), and proteasome inhibitors (Pls). The molecular mechanism of how these drugs induce cardiotoxicity is introduced which includes several signal pathways. These drugs induced cardiotoxicity involved heart failure, hypertension, atherosis and thrombosis, QT interval prolongation, and myocarditis. Some of the cardiotoxicity could be moderate and reversible but others could have happened severely.The aim of this review is to summarise the targeted anti-tumour drugs induced cardiotoxicity and treatment strategies.

Acetylcholine in Carcinogenesis and Targeting Cholinergic Receptors in Oncology

Tumor cells modulate and are modulated by their microenvironments, which include the nervous system. Accumulating evidence links the overexpression and activity of nicotinic and muscarinic cholinergic receptor subtypes to tumorigenesis in breast, ovarian, prostate, gastric, pancreatic, and head and neck cancers. Nicotinic and muscarinic receptors have downstream factors are associated with angiogenesis, cell proliferation and migration, antiapoptotic signaling, and survival. Clinical trials analyzing the efficacy of various therapies targeting cholinergic signaling or downstream pathways of acetylcholine have shed promising light on novel cancer therapeutics. Although the evidence for cholinergic signaling involvement in tumor development is substantial, a more detailed understanding of the acetylcholine-induced mechanisms of tumorigenesis remains to be unlocked. Such an understanding would enable the development of clinical applications ranging from the identification of novel biomarkers to the utilization of existing drugs to modulate cholinergic signaling to the development of novel cancer therapies, as discussed in this review.

Ginkgolide B Regulates CDDP Chemoresistance in Oral Cancer via the Platelet-Activating Factor Receptor Pathway

Simple Summary

The platelet-activating factor receptor (PAFR) is a key molecule that participates in intracellular signaling pathways. It is involved in cancer progression, but the detailed mechanism of its chemosensitivity is unknown. The purpose of the current study was to elucidate the mechanism regulating cisplatin (CDDP) sensitivity through PAFR functions in oral squamous cell carcinoma (OSCC). These results suggest that PAFR is a therapeutic target for modulating CDDP sensitivity in OSCC cells. In addition, we found that ginkgolide B (GB), a specific inhibitor of PAFR, enhanced both CDDP chemosusceptibility and apoptosis. Thus, GB may be a novel drug that could enhance combination chemotherapy with CDDP for OSCC patients.

Abstract

The platelet-activating factor receptor (PAFR) is a key molecule that participates in intracellular signaling pathways, including regulating the activation of kinases. It is involved in cancer progression, but the detailed mechanism of its chemosensitivity is unknown. The purpose of the current study was to elucidate the mechanism regulating cisplatin (CDDP) sensitivity through PAFR functions in oral squamous cell carcinoma (OSCC). We first analyzed the correlation between PAFR expression and CDDP sensitivity in seven OSCC-derived cell lines based upon cell viability assays. Among them, we isolated 2 CDDP-resistant cell lines (Ca9-22 and Ho-1-N-1). In addition to conducting PAFR-knockdown (siPAFR) experiments, we found that ginkgolide B (GB), a specific inhibitor of PAFR, enhanced both CDDP chemosusceptibility and apoptosis. We next evaluated the downstream signaling pathway of PAFR in siPAFR-treated cells and GB-treated cells after CDDP treatment. In both cases, we observed decreased phosphorylation of ERK and Akt and increased expression of cleaved caspase-3. These results suggest that PAFR is a therapeutic target for modulating CDDP sensitivity in OSCC cells. Thus, GB may be a novel drug that could enhance combination chemotherapy with CDDP for OSCC patients.

Metabolomic Identification of Anticancer Metabolites of Australian Propolis and Proteomic Elucidation of Its Synergistic Mechanisms with Doxorubicin in the MCF7 Cells

The combination of natural products with standard chemotherapeutic agents offers a promising strategy to enhance the efficacy or reduce the side effects of standard chemotherapy. Doxorubicin (DOX), a standard drug for breast cancer, has several disadvantages, including severe side effects and the development of drug resistance. Recently, we reported the potential bioactive markers of Australian propolis extract (AP-1) and their broad spectrum of pharmacological activities. In the present study, we explored the synergistic interactions between AP-1 and DOX in the MCF7 breast adenocarcinoma cells using different synergy quantitation models. Biochemometric and metabolomics-driven analysis was performed to identify the potential anticancer metabolites in AP-1. The molecular mechanisms of synergy were studied by analysing the apoptotic profile via flow cytometry, apoptotic proteome array and measuring the oxidative status of the MCF7 cells treated with the most synergistic combination. Furthermore, label-free quantification proteomics analysis was performed to decipher the underlying synergistic mechanisms. Five prenylated stilbenes were identified as the key metabolites in the most active AP-1 fraction. Strong synergy was observed when AP-1 was combined with DOX in the ratio of 100:0.29 (w/w) as validated by different synergy quantitation models implemented. AP-1 significantly enhanced the inhibitory effect of DOX against MCF7 cell proliferation in a dose-dependent manner with significant inhibition of the reactive oxygen species (p < 0.0001) compared to DOX alone. AP-1 enabled the reversal of DOX-mediated necrosis to programmed cell death, which may be advantageous to decline DOX-related side effects. AP-1 also significantly enhanced the apoptotic effect of DOX after 24 h of treatment with significant upregulation of catalase, HTRA2/Omi, FADD together with DR5 and DR4 TRAIL-mediated apoptosis (p < 0.05), contributing to the antiproliferative activity of AP-1. Significant upregulation of pro-apoptotic p27, PON2 and catalase with downregulated anti-apoptotic XIAP, HSP60 and HIF-1α, and increased antioxidant proteins (catalase and PON2) may be associated with the improved apoptosis and oxidative status of the synergistic combination-treated MCF7 cells compared to the mono treatments. Shotgun proteomics identified 21 significantly dysregulated proteins in the synergistic combination-treated cells versus the mono treatments. These proteins were involved in the TP53/ATM-regulated non-homologous end-joining pathway and double-strand breaks repairs, recruiting the overexpressed BRCA1 and suppressed RIF1 encoded proteins. The overexpression of UPF2 was noticed in the synergistic combination treatment, which could assist in overcoming doxorubicin resistance-associated long non-coding RNA and metastasis of the MCF7 cells. In conclusion, we identified the significant synergy and highlighted the key molecular pathways in the interaction between AP-1 and DOX in the MCF7 cells together with the AP-1 anticancer metabolites. Further in vivo and clinical studies are warranted on this synergistic combination.

Emerging Importance of Survivin in Stem Cells and Cancer: the Development of New Cancer Therapeutics

Survivin is one of the rare proteins that is differentially expressed in normal and cancer cells and is directly or indirectly involved in numerous pathways required for tumor maintenance. It is expressed in almost all cancers and its expression has been detected at early stages of cancer. These traits make survivin an exceptionally attractive target for cancer therapeutics. Even with these promising features to be an oncotherapeutic target, there has been limited success in the clinical trials targeting survivin. Only recently it has emerged that survivin was not being specifically targeted which could have resulted in the negative clinical outcome. Also, focus of research has now shifted from survivin expression in the overall heterogeneous tumor cell populations to survivin expression in cancer stem cells as these cells have proved to be the major drivers of tumors. Therefore, in this review we have analyzed the expression of survivin in normal and cancer cells with a particular focus on its expression in cancer stem cell compartment. We have discussed the major signaling pathways involved in regulation of survivin. We have explored the current development status of various types of interventions for inhibition of survivin. Furthermore, we have discussed the challenges involving the development of potent and specific survivin inhibitors for cancer therapeutics. Finally we have given insights for some of the promising future anticancer treatments.

The Molecular Mechanisms of Cardiotoxicity Induced by HER2, VEGF, and Tyrosine Kinase Inhibitors: an Updated Review

AIM

In recent decades, there has been a revolutionary decrease in cancer-related mortality and an increase in survival due to the introduction of novel targeted drugs. Nevertheless, drugs targeting human epidermal growth factor receptor 2 (HER-2), angiogenesis, and other tyrosine kinases also come with unexpected cardiac side effects, including heart failure, hypertension, arterial thrombosis, and arrhythmias, and have mechanisms that are unlike those of classic chemotherapeutic agents. In addition, it is challenging to address some problems, as the existing guidelines need to be more specific, and further large-scale clinical trials and experimental studies are required to confirm the benefit of administering cardioprotective agents to patients treated with targeted therapies. Therefore, an improved understanding of cardiotoxicity becomes increasingly important to minimize the pernicious effects and maximize the beneficial effects of targeted agents.

METHODS

"Cardiotoxicity", "targeted drugs", "HER2", "trastuzumab", "angiogenesis inhibitor", "VEGF inhibitor" and "tyrosine kinase inhibitors" are used as keywords for article searches.

RESULTS

In this article, we report several targeted therapies that induce cardiotoxicity and update knowledge of the clinical evidence, molecular mechanisms, and management measures.

A bismuth diethyldithiocarbamate compound induced apoptosis via mitochondria-dependent pathway and suppressed invasion in MCF-7 breast cancer cells

Interest in bismuth(III) dithiocarbamate complexes as potential drug candidates is increasing due to their low toxicity compared to other group 15 elements (pnictogen) of the periodic table. Bismuth dithiocarbamate compounds have been reported to induce greater cytotoxicity in various human carcinoma cancer cell lines. Using various in vitro cancer-related assays, we investigated the antiproliferative activity of bismuth diethyldithiocarbamate, denoted as 1, against the MCF-7 human breast adenocarcinoma cell line and the effect on genes that may be involved in antiproliferation, apoptosis, DNA fragmentation, invasion and polyubiquitination functions. In general, 1 exhibited high cytotoxicity in MCF-7 cells, with an IC₅₀ of 1.26 ± 0.02 µM, by inducing the intrinsic apoptotic pathway, as ascertained by measurements of intracellular reactive oxygen species (ROS), caspase activity, the amount of cytochrome c released and the extent of DNA fragmentation and by staining assays that reveal apoptotic cells. In addition, 1 significantly attenuated cell invasion and modulated several cancer-related genes, including PLK2, FIGF, FLT4, PARP4, and HDAC11, as determined via gene expression analysis. The NF-κB signaling pathway was inhibited by 1 upon the activation of Lys48- and Lys63-linked polyubiquitination, thus leading to its degradation via the proteasome. Overall, 1 has the potential to act as an antiproliferative agent and a proteasome inhibitor in estrogen-positive breast cancer.

The role of antibody expression and their association with bladder cancer recurrence: a single-centre prospective clinical-pilot study in 35 patients

BACKGROUND

Bladder cancer (BC) is the 10th most common cancer in the UK, with about 10,000 new cases annually. About 75-85% of BC are non-muscle invasive (NMIBC), which is associated with high recurrence and progression rates (50-60% within 7-10 years). There are no routine biomarkers currently available for identifying BC patients at increased risk of developing recurrence. The focus of this research study was to evaluate antibody expression in BC patients and their association with cancer recurrence.

METHODS

35 patients scheduled for TURBT were recruited after written informed consent. Ethical approval for the project was granted via IRAS (REC4: 14/WA/0033). Following surgical procedure, tissues were preserved in 10% buffered formalin and processed within 24 h in FFPE blocks. 7 sections (4 µm each) were cut from each block and stained for CD31, Human epidermal growth factor receptor-2 (HER-2), S100P, Cyclooxygenase-2 (COX-2), VEGFR-3 thrombomodulin and CEACAM-1 using immunohistochemistry. Clinical outcome measures (obtained via cystoscopy) were monitored for up to 6 months following surgical procedure.

RESULTS

There was significantly increased expression of CD31 (p < 0.001), HER-2 (p = 0.032), S100P (p < 0.001), COX-2 (p < 0.001), VEGFR-3 (p < 0.001) and decreased expression of thrombomodulin (p = 0.010) and CEACAM-1 (p < 0.001) in bladder tumours compared to normal bladder tissues. HER-2 expression was also significantly associated with cancer grade (p = 0.003), especially between grade 1 and grade 2 (p = 0.002) and between grade 1 and grade 3 (p = 0.004). There was also a significant association between cancer stage and HER-2 expression (p < 0.001). Although recurrence was significantly associated with cancer grade, there was no association with antibody expression.

CONCLUSION

Findings from the present study may indicate an alternative approach in the monitoring and management of patients with BC. It is proposed that by allowing urological surgeons access to laboratory markers such as HER-2, Thrombomodulin and CD31 (biomarker profile), potentially, in the future, these biomarkers may be used in addition to, or in combination with, currently used scoring systems to predict cancer recurrence. However, verification and validation of these biomarkers are needed using larger cohorts.

JCPyV T-Antigen Activation of the Anti-Apoptotic Survivin Promoter-Its Role in the Development of Progressive Multifocal Leukoencephalopathy

Progressive Multifocal Leukoencephalopathy (PML) is a fatal demyelinating disease of the CNS, resulting from the lytic infection of oligodendrocytes by the human neurotropic polyomavirus JC (JCPyV), typically associated with severe immunocompromised states and, in recent years, with the use of immunotherapies. Apoptosis is a homeostatic mechanism to dispose of senescent or damaged cells, including virally infected cells, triggered in the vast majority of viral infections of the brain. Previously, we showed upregulation of the normally dormant anti-apoptotic protein Survivin in cases of PML, which—in vitro—resulted in protection from apoptosis in JCPyV-infected primary cultures of astrocytes and oligodendrocytes. In the present study, we first demonstrate the absence of apoptotic DNA fragmentation and the lack of caspase activity in 16 cases of PML. We also identified the viral protein large T-Antigen as being responsible for the activation of the Survivin promoter. Chromatin Immunoprecipitation assay shows a direct binding between T-Antigen and the Survivin promoter DNA. Finally, we have identified the specific region of T-Antigen, spanning from amino acids 266 and 688, which binds to Survivin and translocates it to the nucleus, providing evidence of a mechanism that results in the efficient replication of JCPyV and a potential target for novel therapies.

Arming HSV-Based Oncolytic Viruses with the Ability to Redirect the Host's Innate Antiviral Immunity to Attack Tumor Cells

One of the major hurdles for cancer immunotherapy is the host's innate antiviral defense mechanisms. They include innate immune cells, such as natural killer (NK) cells and macrophages, which can be recruited within hours to the site of injection to clear the introduced oncolytic viruses. Here, we report a strategy to redirect these infiltrating innate immune cells to attack tumor cells instead by arming herpes simplex virus (HSV)-derived oncolytic viruses with secreted chimeric molecules that can engage these innate immune cells with tumor cells to kill the latter. These chimeric molecules have, at their N terminus, a custom-binding moiety for a tumor-associated antigen (TAA) and at their C terminus, protein L (PL) that binds to immunoglobulins (Igs). The binding of PL to Igs exposes the Fc to the Fc receptors on the surface of the innate immune cells, trigging them to attack the engaged tumor cells. In vitro and in vivo evaluation in a murine tumor model with limited permissiveness to oncolytic HSVs showed that arming the viruses with these chimeric molecules significantly boosts the killing effect and therapeutic activity. Moreover, our data also showed that the combined killing effect from the engaged innate immune cells and the oncolytic virus resulted in a more efficient stimulation of neoantigen-specific antitumor immunity than the virotherapy alone. Our data suggest that arming an oncolytic virus with this strategy represents a unique and pragmatic way of potentiating the oncolytic and immunotherapeutic effect of virotherapy.

Estrogen-Induced Stromal FGF18 Promotes Proliferation and Invasion of Endometrial Carcinoma Cells Through ERK and Akt Signaling

Objective

The aim of this study was to evaluate whether estrogen promoted the proliferation and invasion of endometrial carcinoma (EC) cells through paracrine FGFs in endometrial stromal cells (ESCs).

Patients and Methods

We screened gene alterations in a primary ESC culture after 10 nM estrogen treatment using an Agilent mRNA microarray. We knocked down stromal FGF18 expression in a co-culture system and aimed to explore the contribution of E2-induced stromal FGF18 to the proliferation and invasion of EC cells. To determine the effective receptors and detailed downstream signaling of FGF18, we co-cultured estrogen-treated hESCs with FGFR1-, FGFR2-, FGFR3- or FGFR4-knockdown Ishikawa cells. Finally, we detected FGF18 expression in clinical samples, including several primary cultures of different ESCs and a series of tissue microarrays (TMAs) of 90 patients with EC.

Results

A few genes altered significantly in estrogen-treated primary ESCs, but only FGF18 was noticeably enhanced among the FGF family genes. Knockdown of FGF18 expression in hESCs inhibited the promoting effect of FGF18 on the proliferation and invasion of EC cells. FGF18 bound FGFR2 and FGFR3 in Ishikawa cells to activate downstream ERK and Akt pathways and to promote the viability of EC cells. The FGF18-FGFR2 and FGF18-FGFR3 pathways had close correlations with Survivin and CD44V6 expression but not with P53. Primary ESCs of endometrioid EC (EEC, type I EC) had higher FGF18 expression than ESCs of normal endometrium (NE), endometrial atypical hyperplasia (EAH) and type II EC.

Conclusion

Estrogen induced FGF18 in ESCs to promote the proliferation and invasion of EC cells, and FGFR inhibitors should be considered as promising candidate targets for EC treatment.

HER4 promotes the progression of colorectal cancer by promoting epithelial‑mesenchymal transition

Colorectal cancer (CRC) remains one of the most common cancer types worldwide. A few previous studies have examined whether HER4 may promote the progression of CRC. The present study examined the associations among the expression levels of members of the HER family, and investigated the potential mechanism underlying the function of HER4 in CRC cells. Immunohistochemistry analysis was conducted to detect the expression levels of HER family members in patients with CRC. HER4 expression was knocked down using short hairpin RNA in HCT116 cells, and confirmed by quantitative PCR and western blotting. The proliferation and adhesion of CRC cells were analyzed by CCK-8 assays and adhesive assays, respectively. Flow cytometry was used to measure cell apoptosis. Western blotting and immunofluorescence staining in CRC cells were performed to identify proteins related to epithelial-mesenchymal transition. The proportion of patients with CRC presenting positive expression of the HER family members epidermal growth factor receptor (EGFR), HER2, HER3 and HER4 were 72.1, 45.2, 43.8 and 34.2%, respectively. No relationship was found between HER4 and EGFR, HER2 or HER3 expression. Higher expression of HER4 was positively associated with lymph node metastasis (P=0.039). In the present study, HER4 expression was found to be associated with an unfavorable clinical outcome in patients with CRC (P_logrank=0.020). Cell proliferation was inhibited, and apoptosis was increased following HER4 knockdown. Furthermore, HER4 knockdown increased the expression of E-cadherin and decreased the expressions of N-cadherin and vimentin (P<0.05). HER4 expression was found to be unrelated to other HER family members. In the present study, positive expression of HER4 promoted the progression of CRC through epithelial-mesenchymal transition.

Effective Treatment of Metastatic Melanoma by Combining MAPK and PI3K Signaling Pathway Inhibitors

Malignant melanoma is the most aggressive type of skin cancer and is closely associated with the development of brain metastases. Despite aggressive treatment, the prognosis has traditionally been poor, necessitating improved therapies. In melanoma, the mitogen activated protein kinase and the phosphoinositide 3-kinase signaling pathways are commonly altered, and therapeutically inhibiting one of the pathways often upregulates the other, leading to resistance. Thus, combined treatment targeting both pathways is a promising strategy to overcome this. Here, we studied the in vitro and in vivo effects of the PI3K inhibitor buparlisib and the MEK1/2 inhibitor trametinib, used either as targeted monotherapies or in combination, on patient-derived melanoma brain metastasis cell lines. Scratch wound and trans-well assays were carried out to assess the migratory capacity of the cells upon drug treatment, whereas flow cytometry, apoptosis array and Western blots were used to study apoptosis. Finally, an in vivo treatment experiment was carried out on NOD/SCID mice. We show that combined therapy was more effective than monotherapy. Combined treatment also more effectively increased apoptosis, and inhibited tumor growth in vivo. This suggests a clinical potential of combined treatment to overcome ceased treatment activity which is often seen after monotherapies, and strongly encourages the evaluation of the treatment strategy on melanoma patients with brain metastases.

Atovaquone: An Antiprotozoal Drug Suppresses Primary and Resistant Breast Tumor Growth by Inhibiting HER2/β-Catenin Signaling

Breast cancer is the second leading cause of cancer-related mortality in women. In the current study, we evaluated the anticancer effects of an antiprotozoal drug, atovaquone, against several breast cancer cell lines. Our results showed that atovaquone treatment induced apoptosis and inhibited the growth of all the breast cancer cell lines tested, including several patient-derived cells. In addition, atovaquone treatment significantly reduced the expression of HER2, β-catenin, and its downstream molecules such as pGSK-3β, TCF-4, cyclin D1, and c-Myc in vitro Efficacy of atovaquone was further evaluated in an in vivo tumor model by orthotropic implantation of two highly aggressive 4T1 and CI66 breast cancer cells in the mammary fat pad of female mice. Our results demonstrated that oral administration of atovaquone suppressed the growth of CI66 and 4T1 tumors by 70% and 60%, respectively. Paclitaxel is the first-line chemotherapeutic agent for metastatic breast cancer. We demonstrate that atovaquone administration suppressed the growth of 4T1 paclitaxel-resistant tumors by 40%. Tumors from atovaquone-treated mice exhibited reduced HER2, β-catenin, and c-Myc levels alongside an increase in apoptosis in all the three tumor models when analyzed by Western blotting, IHC, and TUNEL assay. Taken together, our results indicate that atovaquone effectively reduces the growth of primary and paclitaxel-resistant breast tumors. Atovaquone is already in the clinics with high safety and tolerability profile. Therefore, the findings from our studies will potentially prompt further clinical investigation into repurposing atovaquone for the treatment of patients with advanced breast cancer.

Drug Signature Detection Based on L1000 Genomic and Proteomic Big Data

The library of integrated Network-Based Cellular Signatures (LINCS) project aims to create a network-based understanding of biology by cataloging changes in gene expression and signal transduction. L1000 big datasets provide gene expression profiles induced by over 10,000 compounds, shRNAs, and kinase inhibitors using L1000 platform. We developed a systematic compound signature discovery pipeline named csNMF, which covers from raw L1000 data processing to drug screening and mechanism generation. The discovered compound signatures of breast cancer were consistent with the LINCS KINOMEscan data and were clinically relevant. In this way, the potential mechanisms of compounds' efficacy are elucidated by our computational model.

Identification of Biologically Active Ganoderma lucidum Compounds and Synthesis of Improved Derivatives That Confer Anti-cancer Activities in vitro

We previously reported that Ganoderma lucidum extract (GLE) demonstrate significant anti-cancer activity against triple negative inflammatory breast cancer models. Herein, we aimed to elucidate the bioactive compounds of GLE responsible for this anti-cancer activity. We performed NMR, X-ray crystallography and analog derivatization as well as anti-cancer activity studies to elucidate and test the compounds. We report the structures of the seven most abundant GLE compounds and their selective efficacy against triple negative (TNBC) and inflammatory breast cancers (IBC) and other human cancer cell types (solid and blood malignancies) to illustrate their potential as anti-cancer agents. Three of the seven compounds (ergosterol, 5,6-dehydroergosterol and ergosterol peroxide) exhibited significant in vitro anti-cancer activities, while we report for the first time the structure elucidation of 5,6-dehydroergosterol from Ganoderma lucidum. We also show for the first time in TNBC/IBC cells that ergosterol peroxide (EP) displays anti-proliferative effects through G1 phase cell cycle arrest, apoptosis induction via caspase 3/7 activation, and PARP cleavage. EP decreased migratory and invasive effects of cancer cells while inhibiting the expression of total AKT1, AKT2, BCL-XL, Cyclin D1 and c-Myc in the tested IBC cells. Our investigation also indicates that these compounds induce reactive oxygen species, compromising cell fate. Furthermore, we generated a superior derivative, ergosterol peroxide sulfonamide, with improved potency in IBC cells and ample therapeutic index (TI > 10) compared to normal cells. The combined studies indicate that EP from Ganoderma lucidum extract is a promising molecular scaffold for further exploration as an anti-cancer agent.

Therapeutic strategies involving survivin inhibition in cancer

Survivin is a small protein that belongs to the inhibitor of apoptosis protein family. It is abundantly expressed in tumors compared with adult differentiated tissues, being associated with poor prognosis in many human neoplasms. This apoptotic inhibitor has a relevant role in both the promotion of cancer cell survival and in the inhibition of cell death. Consequently, aberrant survivin expression stimulates tumor progression and confers resistance to several therapeutic strategies in a variety of tumors. In fact, efficient survivin downregulation or inhibition results in spontaneous apoptosis or sensitization to chemotherapy and radiotherapy. Therefore, all these features make survivin an attractive therapeutic target to treat cancer. Currently, there are several survivin inhibitors under clinical evaluation, although more specific and efficient survivin inhibitors are being developed. Moreover, novel combination regimens targeting survivin together with other therapeutic approaches are currently being designed and assessed. In this review, recent progress in the therapeutic options targeting survivin for cancer treatment is analyzed. Direct survivin inhibitors and their current development status are explored. Besides, the major signaling pathways implicated in survivin regulation are described and different therapeutic approaches involving survivin indirect inhibition are evaluated. Finally, promising novel inhibitors under preclinical or clinical evaluation as well as challenges of developing survivin inhibitors as a new therapy for cancer treatment are discussed.

Anabolic and antiresorptive actions of locally delivered bisphosphonates for bone repair: A review

During the last decades, several research groups have used bisphosphonates for local application to counteract secondary bone resorption after bone grafting, to improve implant fixation or to control bone resorption caused by bone morphogenetic proteins (BMPs). We focused on zoledronate (a bisphosphonate) due to its greater antiresorptive potential over other bisphosphonates. Recently, it has become obvious that the carrier is of importance to modulate the concentration and elution profile of the zoledronic acid locally. Incorporating one fifth of the recommended systemic dose of zoledronate with different apatite matrices and types of bone defects has been shown to enhance bone regeneration significantly in vivo. We expect the local delivery of zoledronate to overcome the limitations and side effects associated with systemic usage; however, we need to know more about the bioavailability and the biological effects. The local use of BMP-2 and zoledronate as a combination has a proven additional effect on bone regeneration. This review focuses primarily on the local use of zoledronate alone, or in combination with bone anabolic factors, in various preclinical models mimicking different orthopaedic conditions.

Cite this article: I. Qayoom, D. B. Raina, A. Širka, Š. Tarasevičius, M. Tägil, A. Kumar, L. Lidgren. Anabolic and antiresorptive actions of locally delivered bisphosphonates for bone repair: A review. Bone Joint Res 2018;7:548–560. DOI: 10.1302/2046-3758.710.BJR-2018-0015.R2.

BCL2L12: a multiply spliced gene with independent prognostic significance in breast cancer

Background

Alternative splicing is a key process in carcinogenesis and, from a clinical aspect, holds great promises, as alternatively spliced variants have emerged as an untapped source of diagnostic and prognostic markers. Our aim was to assess the prognostic value of three recently recognized splice variants of the apoptosis-related gene, BCL2L12, in breast cancer (BC).

Methods

Total RNA was extracted from breast samples (150 BC and 80 tumor-adjacent normal tissues) and, following cDNA synthesis, a variant-specific qPCR was performed for the expressional quantification of BCL2L12 v.1, v.2 and v.4 transcript variants. Extensive statistical analysis, including bootstrap resampling and internal validation, was conducted in order to evaluate the associations of v.1, v.2 and v.4 expression with patients’ clinopathological and survival data.

Results

All examined BCL2L12 variants were significantly upregulated in BC specimens compared to their non-cancerous counterpart (v.1, p<0.001; v.2, p=0.009; v.4, p=0.004). Increased BCL2L12 v.4 mRNA expression was associated with markers of unfavorable prognosis namely, advanced tumor grade (p=0.002), ER- (p=0.015)/PR- (p<0.001) negativity, Ki-67-positivity (p=0.007) and high NPI (Nottingham prognostic index) score (p=0.033). Moreover, v.4 was significantly overexpressed in women with triple negative BC (TNBC) and HER2-positive tumors compared to those harboring luminal tumors (p<0.001). Survival analysis disclosed that BCL2L12 v.2 overexpression, as a continuous variable ([HR]=0.45, 95% CI=0.17–0.82, p=0.010), is a strong and independent marker of favorable prognosis for BC patients. Interestingly, v.2 retains its prognostic value in patients with Grade II/III ([HR]=0.21, 95% CI=0.05–0.57, p=0.006) or HER2-positive/TNBC tumors ([HR]=0.25, 95% CI=0.05–0.74, p=0.042).

Conclusions

BCL2L12 v.1, v.2, v.4 are aberrantly expressed in BC. Their expressional analysis by cost-effective molecular methods could provide a novel molecular tool for BC management.

Aberrant CD137 ligand expression induced by GATA6 overexpression promotes tumor progression in cutaneous T-cell lymphoma

CD137 and its ligand, CD137L, are expressed on activated T cells and antigen-presenting cells, respectively. Recent studies have shown that CD137L and CD137 are aberrantly expressed by tumor cells, especially in some hematopoietic malignancies, and interactions between these molecules on tumor cells promote tumor growth. In this study, we investigated the roles of CD137L and CD137 in cutaneous T-cell lymphoma (CTCL), represented by mycosis fungoides and Sézary syndrome. Flow cytometric analysis showed that primary Sézary cells and CTCL cell lines (Hut78, MyLa, HH, SeAx, and MJ) aberrantly expressed CD137L. CD137L expression by tumor cells in CTCL was also confirmed by immunohistochemistry. Anti-CD137L-neutralizing antibody inhibited proliferation, survival, CXCR4-mediated migration, and in vivo growth in CTCL cell lines through inhibition of phosphorylation of AKT, extracellular signal-regulated kinase 1/2, p38 MAPK, and JNK. Moreover, suppression of CD137L signaling decreased antiapoptotic proteins Bcl-2 and phosphorylated Bad. We also explored the transcription factor regulating CD137L expression. Because GATA6 has been proposed as an oncogene in many types of tumors with aberrant CD137L expression, we examined GATA6 expression and the involvement of GATA6 in CD137L expression in CTCL. DNA hypomethylation and histone acetylation induced GATA6 overexpression in CTCL cells. Furthermore, chromatin immunoprecipitation, luciferase reporter assay, and knockdown by short hairpin RNA showed that GATA6 directly upregulated CD137L expression. Inhibition of GATA6 resulted in decreased survival and in vivo growth in CTCL cells. Collectively, our findings prompt a novel therapeutic approach to CTCL based on the discovery that the GATA6/CD137L axis plays an important role in the tumorigenesis of CTCL.

The Cytotoxic and Antimigratory Activity of Brazilin-Doxorubicin on MCF-7/HER2 Cells

Purpose: Breast cancer cells with overexpression of HER2 are known to be more aggressive, invasive, and resistant to chemotherapeutic agent. Brazilin, the major compound in the Caesalpinia sappan L. (CS) heartwood, has been studied for it's anticancer activity. The purpose of this study was to investigate the cytotoxic and antimigratory activity of brazilin (Bi) in combination with doxorubicin (Dox) on MCF-7/HER2 cells.

Methods: Cytotoxic activities of Bi individually and in combination with Dox were examined by MTT assay. Synergistic effects were analyzed by combination index (CI). Apoptosis and cell cycle profiles were observed by using flow cytometry. Migrating and invading cells were observed by using a Boyden chamber assay. Levels of MMP2 and MMP9 activity were observed by using a gelatin zymography assay. Levels of HER2, Bcl-2, Rac1, and p120 protein expression were observed by using an immunoblotting assay.

Results: The results of the MTT assay showed that Bi inhibited MCF-7/HER2 cell growth in a dose-dependent manner with an IC50 of 54 ± 3.7 µM. Furthermore, the combination of Bi and Dox showed a synergistic effect (CI <1). Flow cytometric analysis of Bi and its combination with Dox showed cellular accumulation in the G2/M phase and induction of apoptosis through suppression of Bcl-2 protein expression. In the Boyden chamber assay, gelatin zymography, and subsequent immunoblotting assay, the combination Bi and Dox inhibited migration, possibly through downregulation of MMP9, MMP2, HER2, Rac1, and p120 protein expression.

Conclusion: We conclude that Bi enhanced cytotoxic activity of Dox and inhibited migration of MCF-7/HER2 cells. Therefore, we believe that it has strong potential to be developed for the treatment of metastatic breast cancer with HER2 overexpression.

Polyphenols as Promising Drugs against Main Breast Cancer Signatures

Breast cancer is one of the most common neoplasms worldwide, and in spite of clinical and pharmacological advances, it is still a clinical problem, causing morbidity and mortality. On the one hand, breast cancer shares with other neoplasms some molecular signatures such as an imbalanced redox state, cell cycle alterations, increased proliferation and an inflammatory status. On the other hand, breast cancer shows differential molecular subtypes that determine its prognosis and treatment. These are characterized mainly by hormone receptors especially estrogen receptors (ERs) and epidermal growth factor receptor 2 (HER2). Tumors with none of these receptors are classified as triple negative breast cancer (TNBC) and are associated with a worse prognosis. The success of treatments partially depends on their specificity and the adequate molecular classification of tumors. New advances in anticancer drug discovery using natural compounds have been made in the last few decades, and polyphenols have emerged as promising molecules. They may act on various molecular targets because of their promiscuous behavior, presenting several physiological effects, some of which confer antitumor activity. This review analyzes the accumulated evidence of the antitumor effects of plant polyphenols on breast cancer, with special attention to their activity on ERs and HER2 targets and also covering different aspects such as redox balance, uncontrolled proliferation and chronic inflammation.

The effect of newly synthesized progesterone derivatives on apoptotic and angiogenic pathway in MCF-7 breast cancer cells

Due to its high potency and selectivity, anticancer agents consisting of combined molecules have gained great interests. The current study introduces newly synthesized progesterone derivatives of promising anticancer effect. Moreover, the pro-apoptotic and anti-angiogenic effects of these compounds were studied extensively. Several thiazole, pyridine, pyrazole, thiazolopyridine and pyrazolopyridine progesterone derivatives were synthesized. The structure of the novel progesterone derivatives was elucidated and confirmed using the analytical and spectral data. This novel derivatives were tested for their cytotoxic effect against human breast cancer cells (MCF-7) using neutral red uptake assay. Tested compounds showed anticancer activity against MCF-7 cancer cell line in the descending order of 7>2>3>8>6>9>4. The expression levels of Bcl-2, survivin, CCND1, CDC2, P53 and P21, VEGF, Hif-1α, MMP-2, MMP-9, Ang-1, Ang-2, and FGF-1 genes were investigated using QRT-PCR (Quantitative real time-polymerase chain reaction). The study clarified that compounds 2, 3, 4, 6, 7, 8 and 9 showed significant pro-apoptotic effect through the down regulation of Bcl-2., besides, survivin and CCND1 expression levels were down regulated by compounds 3, 4, 6, 7, 8, 9. However, Compound 4 may exert this pro-apoptotic effect through the up-regulation of P53 gene expression. On the other hand, the anti-angiogenic effect of these newly synthesized derivatives was due to their down regulation of VEGF, Ang-2, MMP-9 and FGF-1; and the up-regulation of HIF-1α and ang-1. This study recommended promising pro-apoptotic and anti-angiogenic anticancer agents acting through the regulation of key regulators of apoptosis, cell cycle genes, and pro-angiogenic genes.

ADAM12-L confers acquired 5-fluorouracil resistance in breast cancer cells

5-FU-based combinatory chemotherapeutic regimens have been routinely used for many years for the treatment of breast cancer patients. Recurrence and chemotherapeutic drug resistance are two of the most prominent factors that underpin the high mortality rates associated with most breast cancers (BC). Increasing evidence indicates that overexpression of ADAMs could correlate with cancer progression. However, the role of ADAMs in the chemoresistance of cancer cells has rarely been reported. In this study, we observed that 5-FU induces expression of the ADAM12 isoform ADAM12-L but not ADAM12-S in BC cells and in recurrent BC tissues. The overexpression of ADAM12-L in BC cells following 5-FU treatment results in the acquisition of resistance to 5-FU. ADAM12-L overexoression also resulted in increased levels of p-Akt but not p-ERK. These alterations enhanced BC cell growth and invasive abilities. Conversely, ADAM12 knockdown attenuated the levels of p-Akt and restored 5-FU sensitivity in 5-FU-resistant BC cells. ADAM12 knockdown also reduced BC cell survival and invasive abilities. These findings suggest that ADAM12-L mediates chemoresistance to 5-FU and 5-FU-induced recurrence of BC by enhancing PI3K/Akt signaling. The results of this study suggest that specific ADAM12-L inhibition could optimize 5-FU-based chemotherapy of BC, thereby preventing BC recurrence in patients.

18 β-glycyrrhetinic acid exhibits potent antitumor effects against colorectal cancer via inhibition of cell proliferation and migration

Accumulating evidence shows that 18 β-glycyr-rhetinic acid (GRA) has antitumor activities in breast, ovarian cancer and leukemia, while its role in colorectal cancer remains unknown. In the present study, we investigated the effect of GRA in colorectal cancer cells LoVo, SW480 and SW620 and studied the underlying molecular mechanisms. Results showed that GRA had potent inhibitory effects on colorectal cancer cell proliferation in a dose- and time-dependent manner in vitro and in vivo. Growth inhibition was mediated by pro-apoptosis, as evident from Annexin V-FITC staining, the reduced expression of survivin and the induced expression of cleaved PARP. Furthermore, GRA treatment resulted in marked reduction of cell migration, invasion and wound healing capability, accompanying by the downregulated MMP expression. Moreover, GRA decreased the protein levels of p-PI3K, p-AKT, p-STAT3, p-JNK, p-p38 and p-NF-κB p65, of which the phosphorylation of PI3K and STAT3 decreased as early as 2 h after the GRA treatment. These results suggest that regulation of the apoptosis, invasion and migration of colorectal cancer cells by GRA might be through suppressing PI3K and STAT3 signaling pathways. the present study indicated that GRA could be a potential effective therapy for patients with colorectal cancer.

Release of HER2 repression of trefoil factor 3 (TFF3) expression mediates trastuzumab resistance in HER2+/ER+ mammary carcinoma

HER2+/ER+ breast cancer, a subset of the luminal B subtype, makes up approximately 10% of all breast cancers. The bidirectional crosstalk between HER2 and estrogen receptor (ER) in HER2+/ER+ breast cancer contributes to resistance towards both anti-estrogens and HER2-targeted therapies. TFF3 promotes breast cancer progression and has been implicated in anti-estrogen resistance in breast cancer. Herein, we investigated the cross-regulation between HER2 and estrogen-responsive TFF3, and the role of TFF3 in mediating trastuzumab resistance in HER2+/ER+ breast cancer. TFF3 expression was decreased by HER2 activation, and increased by inhibition of HER2 with trastuzumab in HER2+/ER+ breast cancer cells, partially in an ERα-independent manner. In contrast, the forced expression of TFF3 activated the entire HER family of receptor tyrosine kinases (HER1-4). Hence, HER2 negatively regulates its own signalling through the transcriptional repression of TFF3, while trastuzumab inhibition of HER2 results in increased TFF3 expression to compensate for the loss of HER2 signalling. In HER2+/ER+ breast cancer cells with acquired trastuzumab resistance, TFF3 expression was markedly upregulated and associated with a corresponding decrease in HER signalling. siRNA mediated depletion or small molecule inhibition of TFF3 decreased the survival and growth advantage of the trastuzumab resistant cells without re-sensitization to trastuzumab. Furthermore, TFF3 inhibition abrogated the enhanced cancer stem cell-like behaviour in trastuzumab resistant HER2+/ER+ breast cancer cells. Collectively, TFF3 may function as a potential biomarker and therapeutic target in trastuzumab resistant HER2+/ER+ breast cancer.

Aberrant Phosphorylation of SMAD4 Thr277-Mediated USP9x-SMAD4 Interaction by Free Fatty Acids Promotes Breast Cancer Metastasis

Obesity increases the risk of distant metastatic recurrence and reduces breast cancer survival. However, the mechanisms behind this pathology and identification of relevant therapeutic targets are poorly defined. Plasma free fatty acids (FFA) levels are elevated in obese individuals. Here we report that TGFβ transiently activates ERK and subsequently phosphorylates SMAD4 at Thr277, which facilitates a SMAD4-USP9x interaction, SMAD4 nuclear retention, and stimulates TGFβ/SMAD3-mediated transcription of Twist and Snail. USP9x inhibited the E3 ubiquitin-protein ligase TIF1γ from binding and monoubiquitinating SMAD4, hence maintaining the SMAD4 nuclear retention. FFA further facilitated TGFβ-induced ERK activation, SMAD4 phosphorylation, and nuclear retention, promoting TGFβ-dependent cancer progression. Inhibition of ERK and USP9x suppressed obesity-induced metastasis. In addition, clinical data indicated that phospho-ERK and -SMAD4 levels correlate with activated TGFβ signaling and metastasis in overweight/obese patient breast cancer specimens. Altogether, we demonstrate the vital interaction of USP9x and SMAD4 for governing TGFβ signaling and dyslipidemia-induced aberrant TGFβ activation during breast cancer metastasis. Cancer Res; 77(6); 1383-94. ©2017 AACR.

Evaluation of heterocyclic steroids and curcumin derivatives as anti-breast cancer agents: Studying the effect on apoptosis in MCF-7 breast cancer cells

Anticancer agents consisting of hybrid molecules are used to improve effectiveness and diminish drug resistance. The current study aimed to introduce newly synthesized hetero-steroids of promising anticancer effects. Besides, the pro-apoptotic effects of new compounds were investigated extensively. Several pyrimidino-, triazolopyrimidino-, pyridazino-, and curcumin-steroid derivatives were synthesized, elucidated and confirmed using the spectral and analytical data. The synthesized hetero-steroids, compounds 9, 10, 11, 12, 13, 14, 15, 18, 20, 21, 22 and 24, were tested for their cytotoxic effects versus human breast cancer cells (MCF-7) using neutral red supravital dye uptake assay. Compound 24 (IC50=18μM) showed more inhibitory influence on MCF-7 growth. Using QRT-PCR (Quantitative real time-polymerase chain reaction), CCND1, Survivin, BCL-2, CDC2, P21 and P53, genes expression levels were investigated. The study results disclose that compounds 4, 7, 18, 24 knocked down the expression levels of CCND1, Survivin, BCL-2 and CDC2. However, P21 and P53 were up-regulated by compounds 21, 22. This study introduced promising pro-apoptotic anticancer agents acting through the modulation of key regulators of apoptosis and cell cycle genes.

The kinesin Eg5 inhibitor K858 induces apoptosis but also survivin-related chemoresistance in breast cancer cells

Inhibitors of kinesin spindle protein Eg5 are characterized by pronounced antitumor activity. Our group has recently synthesized and screened a library of 1,3,4-thiadiazoline analogues with the pharmacophoric structure of K858, an Eg5 inhibitor. We herein report the effects of K858 on four different breast cancer cell lines: MCF7 (luminal A), BT474 (luminal B), SKBR3 (HER2 like) and MDA-MB231 (basal like). We demonstrated that K858 displayed anti-proliferative activity on every analyzed breast cancer cell line by inducing apoptosis. However, at the same time, we showed that K858 up-regulated survivin, an anti-apoptotic molecule. We then performed a negative regulation of survivin expression, with the utilization of wortmannin, an AKT inhibitor, and obtained a significant increase of K858-dependent apoptosis. These data demonstrate that K858 is a potent inhibitor of replication and induces apoptosis in breast tumor cells, independently from the tumor phenotype. This anti-proliferative response of tumor cells to K858 can be limited by the contemporaneous over-expression of survivin; consequently, the reduction of survivin levels, obtained with AKT inhibitors, can sensitize tumor cells to K858-induced apoptosis.

EGFR and HER2 signaling in breast cancer brain metastasis

Breast cancer occurs in approximately 1 in 8 women and 1 in 37 women with breast cancer succumbed to the disease. Over the past decades, new diagnostic tools and treatments have substantially improved the prognosis of women with local diseases. However, women with metastatic disease still have a dismal prognosis without effective treatments. Among different molecular subtypes of breast cancer, the HER2-enriched and basal-like subtypes typically have higher rates of metastasis to the brain. Basal-like metastatic breast tumors frequently express EGFR. Consequently, HER2- and EGFR-targeted therapies are being used in the clinic and/or evaluated in clinical trials for treating breast cancer patients with brain metastases. In this review, we will first provide an overview of the HER2 and EGFR signaling pathways. The roles that EGFR and HER2 play in breast cancer metastasis to the brain will then be discussed. Finally, we will summarize the preclinical and clinical effects of EGFR- and HER2-targeted therapies on breast cancer metastasis.

Breast cancer cells respond differently to docetaxel depending on their phenotype and on survivin upregulation

Breast cancer is characterized by molecular heterogeneity, and four major breast cancer subtypes have been identified, each characterized by significant differences in survival, prognosis, and response to therapy. We have studied the effects of docetaxel treatment on apoptosis and survivin expression in four breast cancer cell lines: MCF7 (luminal A: estrogen receptor-positive and progesterone receptor-positive, ErbB2-negative), BT474 (luminal B: estrogen receptor/progesterone receptor/ErbB2-positive), SKBR3 (HER2-like: estrogen receptor/progesterone receptor-negative, ErbB2-positive), and MDA-MB231 (basal-like: estrogen receptor/progesterone receptor/ErbB2-negative). We demonstrated that docetaxel-induced apoptosis and survivin upregulation (MCF7 p = 0.002, BT474 p = 0.001, SKBR3 p = 0.001) in luminal A/B and HER2-like cells, while it induced mainly necrosis and a lower rate of survivin upregulation (MDA-MB231 p = 0.035) in basal-like cells. Wortmannin, a p-Akt inhibitor, was able to revert surviving upregulation and, at the same time, induced an increase of docetaxel-dependent apoptosis, suggesting that reduced levels of survivin can sensitize tumor cells to apoptosis. These data show that the analyzed breast cancer cell lines respond differently to docetaxel, depending on their receptor expression profile and molecular phenotype. Yet, these data confirm that one of the pathways involved in taxane-related chemoresistance is the upregulation of survivin. Further studies on the molecular mechanisms of chemoresistance and on the different modalities of apoptosis induced by chemotherapeutic agents are requested to better understand how cancer cells evade cell death, in order to design new kind of anticancer agents and survivin could represent a future target for this kind of research.

Cadmium promotes the proliferation of triple-negative breast cancer cells through EGFR-mediated cell cycle regulation

Cadmium (Cd) is a carcinogenic metal which is implicated in breast cancer by epidemiological studies. It is reported to promote breast cancer cell growth in vitro through membrane receptors. The study described here examined Cd-mediated growth of non-metastatic human breast cancer derived cells that lack receptors for estrogen, progesterone, and HER2. Treatment of triple-negative HCC 1937 cells with 0.1-0.5 μM Cd increased cell growth by activation of AKT and ERK. Accelerated cell cycle progression was achieved by increasing the levels of cyclins A, B, and E, as well as those of CDKs 1 and 2. Although triple negative cells lack estrogen receptor, they express high levels of EGFR. Therefore, further studies on HCC 1937 and another triple-negative cell line, HCC 38, were conducted using specific siRNA and an inhibitor of EGFR to determine whether EGFR was responsible for mediating the effect of Cd. The results revealed that in both cell types EGFR was not only activated upon Cd treatment, but was also essential for the downstream activation of AKT and ERK. Based on these observations, it is concluded that, in breast cancer cells lacking estrogen receptor, sub-micromolar concentration of Cd can promote cell proliferation. Furthermore, that EGFR plays a critical role in this process.

Correlation of human epidermal growth factor receptor protein expression and colorectal cancer

AIM: To investigate the correlation between human epidermal growth factor receptor (HER-2) protein expression and colorectal cancer (CRC) using a case-control study and meta-analysis.

METHODS: Tumor tissue specimens from 162 CRC patients were selected for the case group. Fifty cases were randomly selected, and normal CRC tissue at least 10 cm away from the tumor margins of these cases was used to generate the control group. The expression of the HER-2 protein in the 162 CRC tissue samples and the 50 adjacent normal mucosa tissue samples was detected via immunohistochemistry. The experimental data were analyzed using SPSS 18.0 software, and R software version 3.1.0 was utilized for further verification.

RESULTS: The expression of HER-2 protein in the 162 CRC tissue samples was significantly higher than in the normal tissue specimens. The data showed that the expression of HER-2 in CRC was related to the Dukes’ stage, the depth of invasion and lymph node metastasis. The HER-2-positive patients had lower 3- and 5-year OS rates than the HER-2-negative patients, but there was no significant difference. However, there was a statistically significant difference in the 3- and 5-year disease-free survival (DFS) rates of HER-2-positive and HER-2-negative patients. The results of the meta-analysis showed that the expression of HER-2 in CRC patients was statistically significantly increased over that of healthy people. The 3-year DFS rate in HER-2-positive patients was markedly lower than that in HER-2-negative patients.

CONCLUSION: Down-regulation of HER-2 expression might be a dependable strategy for CRC therapy.

YM155 exerts a growth inhibitory effect on human osteosarcoma in vitro and in vivo

YM155, a novel small-molecule inhibitor of survivin, is known to exert antitumor effects on various cancers, including breast, prostate and lung cancer. However, there are few studies describing the inhibitory effect of YM155 on human osteosarcoma (OS) which highly expresses survivin. Here, we tested the effects of YM155 on OS cells by several in vitro experiments. It was found that YM155 inhibited cell proliferation, colony formation, migration and invasion, induced cell apoptosis, as well as increased caspase-3, -8 and -9 activity in the OS cell lines in a dose-dependent manner. We also found that YM155 suppressed Mcl-1 and survivin expression without affecting the expression of anti-apoptotic proteins X-linked inhibitor of apoptosis (XIAP) and Bcl-2. In addition, YM155 decreased phosphoinositide 3-kinase (PI3K) and AKT expression without effecting total PI3K and AKT in the OS cell lines, which contributed to suppression of OS tumor growth at least in part. In addition, YM155 also suppressed tumor growth in vivo, reducing the size of OS MG63 cell xenografts. Taken together, the findings revealed that YM155 suppresses the tumor growth of OS in vitro and in vivo, suggesting that YM155 has potential as a therapeutic agent for the treatment of OS.

Special suppressive role of miR-29b in HER2-positive breast cancer cells by targeting Stat3

OBJECTIVES

MiR-29b has been reported to function as a tumor suppressor in a variety of cancers. However, its role in the regulation of breast cancer is controversial.

MATERIALS AND METHODS

In this paper, we explored the expression of miR-29b in a cohort of 67 pairs of formalin-fixed paraffin-embedded specimens with detailed pathological and clinical characteristics, and further analyzed the effects of miR-29b on the malignant phenotype of HER-2-positive breast cancer cells and the relevant mechanisms involved.

RESULTS

We found that the miR-29b expression is negatively associated with HER-2 expression in breast cancer tissues. Moreover, overexpression of miR-29b induced a complex phenotype in HER-2-positive breast cancer cells, namely an inhibition of cell proliferation, block of G1/S phase transition, induction of cell apoptosis, suppression of cell invasion in vitro, as well as inhibition on tumor growth in vivo, indicating that miR-29b functions as a tumor suppressor in HER2-positive breast cancer cells. Further bioinformatic prediction suggested that oncogene Stat3, which is an up-stream regulator of HER-2, was a target gene of miR-29b in breast cancer cells. We have shown that knocking down of Stat3 attenuated the malignant phenotype of breast cancer cells similar to overexpression of miR-29b, while restore expression of Stat3 in HER-2-positive breast cancer cells partially abolished the suppressive effects of miR-29b.

CONCLUSION

Collectively, our data suggest that miR-29b could reverse the malignant phenotype of HER-2-positvie breast cancer through, at least partially, targeting Stat3 signaling pathway.

Compound signature detection on LINCS L1000 big data

The Library of Integrated Network-based Cellular Signatures (LINCS) L1000 big data provide gene expression profiles induced by over 10 000 compounds, shRNAs, and kinase inhibitors using the L1000 platform. We developed csNMF, a systematic compound signature discovery pipeline covering from raw L1000 data processing to drug screening and mechanism generation. The csNMF pipeline demonstrated better performance than the original L1000 pipeline. The discovered compound signatures of breast cancer were consistent with the LINCS KINOMEscan data and were clinically relevant. The csNMF pipeline provided a novel and complete tool to expedite signature-based drug discovery leveraging the LINCS L1000 resources.

Notch-EGFR/HER2 Bidirectional Crosstalk in Breast Cancer

The Notch pathway is a well-established mediator of cell-cell communication that plays a critical role in stem cell survival, self-renewal, cell fate decisions, tumorigenesis, invasion, metastasis, and drug resistance in a variety of cancers. An interesting form of crosstalk exists between the Notch receptor and the Epidermal Growth Factor Receptor Tyrosine Kinase family, which consists of HER-1, -2, -3, and -4. Overexpression of HER and/or Notch occurs in several human cancers including brain, lung, breast, ovary, and skin making them potent oncogenes capable of advancing malignant disease. Continued assessment of interplay between these two critical signaling networks uncovers new insight into mechanisms used by HER-driven cancer cells to exploit Notch as a compensatory pathway. The compensatory Notch pathway maintains HER-induced downstream signals transmitted to pathways such as Mitogen Activated Protein Kinase and Phosphatidylinositol 3-Kinase (PI3K), thereby allowing cancer cells to survive molecular targeted therapies, undergo epithelial to mesenchymal transitioning, and increase cellular invasion. Uncovering the critical crosstalk between the HER and Notch pathways can lead to improved screening for the expression of these oncogenes enabling patients to optimize their personal treatment options and predict potential treatment resistance. This review will focus on the current state of crosstalk between the HER and Notch receptors and the effectiveness of current therapies targeting HER-driven cancers.

Characterization of β2-microglobulin expression in different types of breast cancer

Background

Βeta-2-microglobulin (β2-M) has been demonstrated as a growth factor and signaling molecule in breast cancer and leukemia. The purpose of the study is to characterize β2-M expression in molecular subtypes of breast cancer, thereby investigating the mechanism of β2-M action in breast cancer.

Methods

β2-M and B-Cell Lymphoma/Leukemia 2 (Bcl-2) transcript expression levels in breast cancer tissue and the corresponding normal tissue were quantified using real-time PCR. The protein expression levels of β2-M, estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER-2), tumor protein 53 (p53) and Ki67 were determined by immunohistochemical (IHC) staining. Following silencing of the β2-M by siRNA, the levels of Bcl-2, ER, PR and HER-2 transcripts and the protein expression levels in human breast cancer cells were measured by real-time PCR and western blotting, respectively.

Results

The expression of β2-M transcripts demonstrated no significant differences between the four breast cancer molecular subtypes and no significant correlations with age, clinical stage or lymph node metastasis. β2-M transcript expression demonstrated a positive correlation when compared to Bcl-2 transcript expression (P < 0.05). The β2-M protein expression was significantly higher in breast cancer when compared with benign breast tumors (P < 0.01), and have no significant correlation with age, clinical stage or lymph node metastasis. There was a significant difference demonstrated in β2-M protein expression in the four breast cancer molecular subtypes (P < 0.05), and between the ER⁺ and ER⁻ groups (P < 0.01); however, no significant difference was demonstrated between the HER-2⁺ and HER-2⁻ groups. β2-M protein expression had a negative correlation with ER protein expression (P < 0.01), a positive correlation with p53 protein expression (P < 0.01), and no correlation with Ki67 protein expression. β2-M silencing significantly inhibited Bcl-2 mRNA expression, but did not inhibit ER, PR and HER-2 mRNA expression in MCF-7 cells (ER⁺, PR⁺ and HER-2⁻). In addition, Bcl-2 and HER-2 mRNA expression were significantly up-regulated in MDA-MB-231 cells (ER⁻, PR⁻ and HER-2⁻), which is consistent with the silencing effect seen at the protein level.

Conclusions

β2-M expression demonstrated a significant difference in the four breast cancer molecular subtypes, and may be related to apoptosis regulation in breast cancer.

The expression of platelet-activating factor receptor modulates the cisplatin sensitivity of ovarian cancer cells: a novel target for combination therapy

BACKGROUND

Ovarian cancer has the highest mortality rate of the gynaecological cancers. Although cisplatin (CDDP) is an effective treatment for ovarian cancer, recurrence is frequent and leads to death. The objective was to explore the role and possible mechanisms of platelet-activating factor receptor (PAFR) signalling in CDDP-treated ovarian cancer cells.

METHODS

The upregulation of PAFR in CDDP-treated ovarian cancer cells was observed using realtime PCR and Western blot. The potential role of PAFR in modulating the CDDP sensitivity was assessed using a pharmacological inhibitor and siRNA knockdown. The PAFR-activated signalling pathways involved in cell responses to CDDP were assessed.

RESULTS

Cisplatin induced increased PAFR expression in two ovarian cancer cell lines. The upregulation of PAFR by CDDP correlated with the time-dependent accumulation of NF-κB and HIF-1α in the nucleus. The inhibition of PAFR sensitised the ovarian cancer cells to CDDP. The PI3K and ERK pathways lie downstream of activated PAFR in CDDP-treated cells and their inhibition enhanced CDDP sensitivity. Finally, co-treatment with a PAFR antagonist (Ginkgolide B) and CDDP markedly reduced tumour growth in an in vivo model of ovarian cancer.

CONCLUSIONS

Together, these findings suggest that PAFR is a novel and promising therapeutic target for sensitising ovarian cancer cells to CDDP.

Antitumor effects of cisplatin implants against human gastric cancer in nude mice

AIM: To assess the antitumor effects of cisplatin implants vs common cisplatin injection in a xenograft nude mouse model of human gastric cancer.

METHODS: A xenograft nude mouse model of human gastric cancer was established by subcutaneously injecting SGC7901 cells in Balb/c nude mice. The model mice were divide into four groups randomly: A (intravenous injection of PBS via the tail vein), B (intravenous injection of cisplatin via the tail vein), C (intratumor injection of cisplatin), and D (cisplatin implantation). After drug intervention, tumor weight and volume were calculated. Tumor tissues were observed by HE staining. The protein expression of spleen tyrosine kinase (SYK)/human epidermal growth factor receptor 2 (HER2), phosphate and tension homology deleted on chromsome ten (PTEN)/the sixth variant form of adhesion molecule CD44 (CD44v6) and cysteinyl aspartate specific protease 3 (Caspase3)/Survivin in tumor tissue was detected by immunohistochemistry. Cell apoptosis was detected by flow cytometry.

RESULTS: Sustained-release cisplatin significantly promoted apoptosis, suppressed tumor growth, enhanced the expression of SYK (group D: 73.42 ± 4.92 vs group C: 30.42 ± 3.92, P < 0.05; group B: 14.14 ± 2.84 vs group A: 5.06 ± 2.96, P < 0.05), PTEN (group D: 62.46 ± 4.36 vs group C: 29.82 ± 2.22, P < 0.05; group B: 16.06 ± 4.26 vs group A: 6.44 ± 2.84, P < 0.05) and Caspase3 (group D: 77.58 ± 6.28 vs group C: 31.26 ± 4.76, P < 0.05; group B: 15.24 ± 4.64 vs group A: 10.82 ± 2.72, P < 0. 05), and reduced the expression of HER2 (group D: 16.32 ± 4.82 vs group C: 34.82 ± 7.32, P < 0.05; group B: 45.8 ± 6.60 vs group A: 77.34 ± 9.04, P < 0.05), CD44v6 (group D: 4.60 ± 1.40 vs group C: 10.32 ± 1.72, P < 0.05; group B: 28.10 ± 5.60 vs group A: 69.02 ± 1.52, P < 0.05) and Survivin (group D: 18.42 ± 4.62 vs group C: 31.3 ± 9.50, P < 0.05; group B: 69.66 ± 9.46 vs group A: 84.64 ± 5.04, P < 0.05).

CONCLUSION: Cisplatin implants exert anticancer effects against human gastric cancer in nude mice by promoting apoptosis and altering the expression of SYK, PTEN, Caspase3, HER2, CD44v6, and Survivin.

Effect of cisplatin implantation on human gastric carcinoma xenograft growth in nude mice and tumor expression of SYK and HER2

AIM: To assess the effect of cisplatin implantation on human gastric carcinoma xenograft growth and tumor expression of SYK and HER2 in nude mice, and to discuss the mechanism of action of sustained-release cisplatin.

METHODS: A xenograft model of human gastric carcinoma was established by subcutaneous injection of SGC7901 cells in Balb/c nude mice. The mice were then randomly divided into four groups to receive intravenous injection of PBS (group A), intravenous injection of cisplatin (group B), intratumor injection of cisplatin (group C), and implantation of cisplatin (group D). After drug intervention, tumor weight and tumor inhibition rate were measured. Tumor tissues were observed after HE staining. Expression of SYK/HER2 was detected by immunohistochemsitry. Besides, the cell suspensions prepared from the tumor tissues from the four groups were tested by FCM.

RESULTS: Sustained-release cisplatin could promote apoptosis and suppress tumor growth significantly, and it also could enhance the expression of SYK (group D: 73.42 ± 4.92 vs group C: 30.42 ± 3.92, P < 0.05; group B: 14.14 ± 2.84 vs group A: 5.06 ± 2.96, P < 0.05) and reduce the expression of HER2 (group D: 16.32 ± 4.82 vs group C: 34.82 ± 7.32, P < 0.05; group B: 45.8 ± 6.60 vs group A: 77.34 ± 9.04, P < 0.05).

CONCLUSION: Cisplatin implantation induces tumor cell apoptosis and exerts anticancer function possibly by enhancing the expression of SYK and reducing the expression of HER2.

Survivin as a preferential target for cancer therapy

Cancer is typically a consequence of imbalance between cell death and proliferation in a way favorable to cell proliferation and survival. Most conventional cancer therapies are based on targeting rapidly growing cancerous cells to block growth or enhance cell death, thereby, restoring the balance between these processes. In many instances, malignancies that develop resistance to current treatment modalities, such as chemotherapy, immunotherapy, and radiotherapy often present the greatest challenge in subsequent management of the patient. Studies have shown that under normal circumstances, cells utilize different death mechanisms, such as apoptosis (programmed cell death), autophagy, mitotic catastrophe, and necrosis to maintain homeostasis and physiological integrity of the organism, but these processes often appear to be altered in cancer. Thus, in recent years developing various strategies for administration of cytotoxic chemotherapeutics in combination with apoptosis-sensitizing reagents is receiving more emphasis. Here, we review the properties of the anti-apoptotic protein, survivin, a member of the inhibitor of apoptosis protein (IAP) family and the clinical feasibility and anti-cancer potential of drugs targeting this protein. We also discuss some key points and concerns that should be taken into consideration while developing drugs that target apoptotic proteins, such as survivin.

STAT3 activation in HER2-overexpressing breast cancer promotes epithelial-mesenchymal transition and cancer stem cell traits

Clinically, HER2 proto-oncogene amplification is found in about 25–30% of human breast cancers, where it is correlated to a poor prognosis. Constitutive STAT3 activation is found in about 50–60% of the breast tumors and associated with tumorigenesis and drug resistance. In this study, we showed that STAT3 was phosphorylated in HER2-overexpressing, ER-positive human breast tumors and, furthermore, phosphorylated STAT3 promoted the stem-like cell phenotype. We examined the dysregulation of the stem cell markers (Oct-4, Sox-2 and CD44) and the tumorsphere formation in HER2-overexpressing human breast cancer cell lines. We demonstrated that the STAT3 inhibitor, Stattic, treatment abolished the cancer stem cell phenotype in HER2-positive breast cancers. Combined treatment of Herceptin and Stattic showed the synergistic effect on the cancer cell growth in vitro. In addition, when the STAT3 gene was knocked down, the expression of the stem cell markers Oct-4, Sox-2 and CD44 were downregulated and tumorsphere formation was abolished. HER2-elicited STAT3 signaling may provide a potential model for drug resistance induced by stem-like cell characteristics. This mechanism may be responsible for acquiring resistance to Herceptin in the treatment of HER2-overexpressing breast tumors. Based on our findings, targeting pSTAT3 could overcome Herceptin-induced resistance in HER2-overexpressing breast tumors.