Autocrine human growth hormone increases sensitivity of mammary carcinoma cell to arsenic trioxide-induced apoptosis

The mechanism of arsenic trioxide and microwave ablation in the treatment of oral squamous cell carcinoma based on high throughput sequencing

Oral squamous cell carcinoma (OSCC) is a common head and neck malignant tumour with high incidence and poor prognosis. Arsenic trioxide (ATO) has therapeutic effects on solid tumours. Microwave ablation (MWA) has unique advantages in the treatment of solid tumours. However, the therapeutic mechanism of ATO and MWA, as well as their combined effect on OSCC were largely unelucidated. Cal-27 cell-bearing nude mice were treated with ATO and/or MWA, respectively. RNA sequencing was used to obtain gene expression profiles in tumour tissues of mice treated by ATO or MWA. RNA sequencing results were verified by real-time polymerase chain reaction (PCR). The lncRNA-miRNA-mRNA co-expression network was constructed based on the competitive endogenous RNA (ceRNA) theory. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed using differentially expressed genes. The combined effect of ATO and MWA on OSCC was evaluated. Finally, CCK-8 assay, EdU assay and transwell migration assay were performed to detect the effect of HSPA6 on the proliferation and migration of OSCC cells. The reduced volume of tumour tissues was observed in both ATO- and MWA-treated groups. 37.8% decreased in the ATO group and 35.0% in the MWA group. A total of 207 and 539 differentially expressed mRNAs and lncRNAs were identified in the ATO group. And a total of 200 and 522 differentially expressed mRNAs and lncRNAs in the MWA group were identified. The expression levels of 8 genes were verified by real-time PCR. The differentially expressed genes were closely related to "chemical carcinogenesis", "herpes simplex infection", "porphyrin and chlorophyll metabolism", and "MAPK signalling pathway". The lncRNA-miRNA-mRNA co-expression networks were constructed. The combined treatment with ATO and MWA showed a better inhibitive effect on OSCC than either of them. The synergistic effect of ATO and MWA was related to the upregulation of HSPA6. The downregulation of HSPA6 could promote the proliferation and migration of OSCC cells. This study detected the long non-coding RNA and mRNA expression profiles related to the treatment of OSCC and constructed corresponding ceRNA networks. Arsenic trioxide and MWA have a synergistic effect on OSCC, which was related to the upregulation of HSPA6.

Human Growth Hormone Fragment 176–191 Peptide Enhances the Toxicity of Doxorubicin-Loaded Chitosan Nanoparticles Against MCF-7 Breast Cancer Cells

Introduction

Numerous drugs with potent toxicity against cancer cells are available for treating malignancies, but therapeutic efficacies are limited due to their inefficient tumor targeting and deleterious effects on non-cancerous tissue. Therefore, two improvements are mandatory for improved chemotherapy 1) novel delivery techniques that can target cancer cells to deliver anticancer drugs and 2) methods to specifically enhance drug efficacy within tumors. The loading of inert drug carriers with anticancer agents and peptides which are able to bind (target) tumor-related proteins to enhance tumor drug accumulation and local cytotoxicity is a most promising approach.

Objective

To evaluate the anticancer efficacy of Chitosan nanoparticles loaded with human growth hormone hGH fragment 176–191 peptide plus the clinical chemotherapeutic doxorubicin in comparison with Chitosan loaded with doxorubicin alone.

Methods

Two sets of in silico experiments were performed using molecular docking simulations to determine the influence of hGH fragment 176–191 peptide on the anticancer efficacy of doxorubicin 1) the binding affinities of hGH fragment 176–191 peptide to the breast cancer receptors, 2) the effects of hGH fragment 176–191 peptide binding on doxorubicin binding to these same receptors. Further, the influence of hGH fragment 176–191 peptide on the anticancer efficacy of doxorubicin was validated using viability assay in Human MCF-7 breast cancer cells.

Results

In silico analysis suggested that addition of the hGH fragment to doxorubicin-loaded Chitosan nanoparticles can enhance doxorubicin binding to multiple breast cancer protein targets, while photon correlation spectroscopy revealed that the synthesized dual-loaded Chitosan nanoparticles possess clinically favorable particle size, polydispersity index, as well as zeta potential.

Conclusion

These dual-loaded Chitosan nanoparticles demonstrated greater anti-proliferative activity against a breast cancer cell line (MCF-7) than doxorubicin-loaded Chitosan. This dual-loading strategy may enhance the anticancer potency of doxorubicin and reduce the clinical side effects associated with non-target tissue exposure.

Effects of co-administration of arsenic trioxide and Schiff base oxovanadium complex on the induction of apoptosis in acute promyelocytic leukemia cells

Acute promyelocytic leukaemia (APL) is commonly treated with arsenic trioxide (As2O3) that has many side effects. Given the increasing trend of studies on beneficial therapeutic properties of synthetic compounds containing vanadium, the present study sought to use Schiff base oxovanadium complex to reduce the needed concentration of arsenic trioxide. The HL-60 cell line, which is a model of APL, was selected and the effects of arsenic trioxide and Schiff base oxovanadium complex were individually and simultaneously evaluated on the cell viability by the MTT assay. Flow cytometry and Real-time RT-PCR were also performed to investigate the rate of apoptosis and the expression of P53 and P21 genes, respectively. The IC50 of arsenic trioxide and Schiff base oxovanadium complex on Hl-60 cells was 8.37 ± 0.36 µM and 34.12 ± 1.52 µg/ml, respectively. At the simultaneous administration of both compounds, the maximum decrease in the cell viability was seen in co-administration of 40 µg/ml of Schiff base oxovanadium complex and 0.001 µM of arsenic trioxide. Real-time RT-PCR indicated that the co-administration of Schiff base oxovanadium complex 40 µg/ml and arsenic trioxide 0.001 µM could increase the expression of P53 and P21 genes by 3.76 ± 0.19 and 6.57 ± 1.29 fold change, respectively to the control sample. The flow cytometry studies also indicated that this co-administration could induce apoptosis up to 67% ± 0.9% significantly higher than the control sample. The use of Schiff base oxovanadium complex could significantly reduce the required dose of arsenic trioxide to induce apoptosis in HL-60 cells.

Silencing growth hormone receptor inhibits estrogen receptor negative breast cancer through ATP-binding cassette sub-family G member 2

Growth hormone receptor (GHR) plays a vital role in breast cancer chemoresistance and metastasis but the mechanism is not fully understood. We determined if GHR could be a potential therapeutic target for estrogen receptor negative (ER-ve) breast cancer, which are highly chemoresistant and metastatic. GHR was stably knocked down in ER-ve breast cancer cells and its effect on cell proliferation, metastatic behavior, and chemosensitivity to docetaxel (DT) was assessed. Microarray analysis was performed to identify potential GHR downstream targets involved in chemoresistance. GHR and ATP-binding cassette sub-family G member 2 (ABCG2) overexpression and knockdown studies were performed to investigate the mechanism of GHR-induced chemoresistance. Patient-derived xenografts was used to study the effect of GHR and ABCG2. Immunohistochemical data was used to determine the correlation between GHR, pAKT, pmTOR, and ABCG2 expressions. GHR silencing drastically reduced the chemoresistant and metastatic behavior of ER-ve breast cancer cells and also inhibited AKT/mTOR pathway. In contrast, activation, or overexpression of GHR increased chemoresistance and metastasis by increasing the expression and promoter activity, of ABCG2. Inhibition of JAK2/STAT5 signaling repressed GHR-induced ABCG2 promoter activity and expression. Further, ABCG2 knockdown significantly increased the chemosensitivity. Finally, patient-derived xenograft studies revealed the role of GHR in chemoresistance. Overall, these findings demonstrate that targeting GHR could be a novel therapeutic approach to overcome chemoresistance and associated metastasis in aggressive ER-ve breast cancers.

Curcumin prevented human autocrine growth hormone (GH) signaling mediated NF-κB activation and miR-183-96-182 cluster stimulated epithelial mesenchymal transition in T47D breast cancer cells

Autocrine growth hormone (GH) signaling is a promoting factor for breast cancer via triggering abnormal cell growth, proliferation, and metastasis, drug resistance. Curcumin (diferuloylmethane), a polyphenol derived from turmeric (Curcuma longa), has anti-proliferative, anti-carcinogenic, anti-hormonal effect via acting on PI3K/Akt, NF-κB and JAK/STAT signaling. Forced GH expression induced epithelial mesenchymal transition (EMT) through stimulation of miR-182-96-183 cluster expression in breast cancer cells. This study aimed to investigate the role of NF-κB signaling and miR-182-96-183 cluster expression profile on autocrine GH-mediated curcumin resistance, which was prevented by time-dependent curcumin treatment in T47D breast cancer cells. Dose- and time-dependent effect of curcumin on T47D wt and GH+ breast cancer cells were evaluated by MTT cell viability and trypan blue assay. Apoptotic effect of curcumin was determined by PI and Annexin V/PI FACS flow analysis. Immunoblotting performed to investigate the effect of curcumin on PI3K/Akt/MAPK, NF-κB signaling. miR182-96-183 cluster expression profile was observed by qRT-PCR. Overexpression of GH triggered resistant profile against curcumin (20 µM) treatment for 24 h, but this resistance was accomplished following 48 h curcumin exposure. Concomitantly, forced GH induced invasion and metastasis through EMT and NF-κB activation were prevented by long-term curcumin exposure in T47D cells. Moreover, 48 h curcumin treatment prevented the autocrine GH-mediated miR-182-96-183 cluster expression stimulation in T47D cells. In consequence, curcumin treatment for 48 h, prevented autocrine GH-triggered invasion-metastasis, EMT activation through inhibiting NF-κB signaling and miR-182-96-183 cluster expression and induced apoptotic cell death by modulating Bcl-2 family members in T47D breast cancer cells.

Blockade of JAK2/STAT3 intensifies the anti-tumor activity of arsenic trioxide in acute myeloid leukemia cells: Novel synergistic mechanism via the mediation of reactive oxygen species

Reactive oxygen species (ROS) are essential mediators of crucial cellular processes including apoptosis, proliferation, survival and cell cycle. Their regulatory role in cancer progression has seen in different human malignancies such as acute myeloid leukemia (AML). AML patients suffer from high resistance of the tumors against routine therapeutics including ATO. ATO enhance reactive oxygen species levels and induce apoptosis and suppresses proliferation in AML cells. However, some pathways such as JAK2/STAT3 ease anti-tumor activity of ATO by reducing reactive oxygen species amount and protecting the cell from apoptosis. In the present study, we use ruxolitinib (potent JAK2 inhibitor) to increase the sensitivity of AML cells to ATO treatment. We test, the effect of this combination on metabolic activity, proliferation, colony formation, cell cycle distribution, apoptosis, oxidative stress and DNA damage. Our results showed that combination of ATO with ruxolitinib synergistically reduced metabolic activity, proliferation and survival of AML cell lines. This combination induced G1/S cell cycle arrest because of reactive oxygen species elevation and GSH reduction. Besides, enhancement of reactive oxygen species increased apoptosis rate in combination samples. We uncovered that the synergistic anti-tumor effect of ATO and ruxolitinib in AML cells mediates via reactive oxygen species elevation and DNA damage. Overall, our results show that the combinatorial therapy of AML cells is more effective than solo-targeted therapy.

Curcumin inhibits autocrine growth hormone-mediated invasion and metastasis by targeting NF-κB signaling and polyamine metabolism in breast cancer cells

Curcumin is assumed to be a plant-derived therapeutic drug that triggers apoptotic cell death in vitro and in vivo by affecting different molecular targets such as NF-κB. Phase I/II trial of curcumin alone or with chemotherapeutic drugs has been accomplished in pancreatic, colon, prostate and breast cancer cases. Recently, autocrine growth hormone (GH) signaling-induced cell growth, metastasis and drug resistance have been demonstrated in breast cancer. In this study, our aim was to investigate the potential therapeutic effect of curcumin by evaluating the molecular machinery of curcumin-triggered apoptotic cell death via focusing on NF-κB signaling and polyamine (PA) metabolism in autocrine GH-expressing MCF-7, MDA-MB-453 and MDA-MB-231 breast cancer cells. For this purpose, a pcDNA3.1 (+) vector with a GH gene insert was transfected by a liposomal agent in all breast cancer cells and then selection was conducted in neomycin (G418) included media. Autocrine GH-induced curcumin resistance was overcome in a dose-dependent manner and curcumin inhibited cell proliferation, invasion-metastasis and phosphorylation of p65 (Ser536), and thereby partly prevented its DNA binding activity in breast cancer cells. Moreover, curcumin induced caspase-mediated apoptotic cell death by activating the PA catabolic enzyme expressions, which led to generation of toxic by-products such as H₂O₂ in MCF-7, MDA-MB-453 and MDA-MB-231 GH+ breast cancer cells. In addition, transient silencing of SSAT prevented curcumin-induced cell viability loss and apoptotic cell death in each breast cancer cells. In conclusion, curcumin could overcome the GH-mediated resistant phenotype via modulating cell survival, death-related signaling routes and activating PA catabolic pathway.

Environmental arsenic exposure: From genetic susceptibility to pathogenesis

More than 200 million people in 70 countries are exposed to arsenic through drinking water. Chronic exposure to this metalloid has been associated with the onset of many diseases, including cancer. Epidemiological evidence supports its carcinogenic potential, however, detailed molecular mechanisms remain to be elucidated. Despite the global magnitude of this problem, not all individuals face the same risk. Susceptibility to the toxic effects of arsenic is influenced by alterations in genes involved in arsenic metabolism, as well as biological factors, such as age, gender and nutrition. Moreover, chronic arsenic exposure results in several genotoxic and epigenetic alterations tightly associated with the arsenic biotransformation process, resulting in an increased cancer risk. In this review, we: 1) review the roles of inter-individual DNA-level variations influencing the susceptibility to arsenic-induced carcinogenesis; 2) discuss the contribution of arsenic biotransformation to cancer initiation; 3) provide insights into emerging research areas and the challenges in the field; and 4) compile a resource of publicly available arsenic-related DNA-level variations, transcriptome and methylation data. Understanding the molecular mechanisms of arsenic exposure and its subsequent health effects will support efforts to reduce the worldwide health burden and encourage the development of strategies for managing arsenic-related diseases in the era of personalized medicine.

Tumour-Derived Human Growth Hormone As a Therapeutic Target in Oncology

The growth hormone (GH) and insulin-like growth factor-1 (IGF1) axis is the key regulator of longitudinal growth, promoting postnatal bone and muscle growth. The available data suggest that GH expression by tumour cells is associated with the aetiology and progression of various cancers such as endometrial, breast, liver, prostate, and colon cancer. Accordingly there has been increased interest in targeting GH-mediated signal transduction in a therapeutic setting. Because GH has endocrine, autocrine, and paracrine actions, therapeutic strategies will need to take into account systemic and local functions. Activation of related hormone receptors and crosstalk with other signalling pathways are also key considerations.

Synergistic cytotoxic effects of arsenite and tetrandrine in human breast cancer cell line MCF-7

To provide novel insight into the development of new therapeutic strategies to combat breast cancer using trivalent arsenic (AsIII)-based combination therapy, the cytotoxicity of a combination of AsIII and tetrandrine (Tetra), a Chinese plant-derived alkaloid, was investigated in the human breast cancer cell line MCF-7. Cytotoxicity was evaluated using cell viability, colony formation, wound healing, lactate dehydrogenase leakage and cell cycle assay. Alterations of genes associated with cell proliferation and death were analyzed using real-time PCR and western blotting. Intracellular arsenic accumulation (As[i]) was also determined. Tetra significantly enhanced the cytotoxicity of AsIII in MCF-7 cells in a synergistic manner. The combined treatment upregulated the expression level of FOXO3a, and subsequently resulted in a concomitant increase in the expression levels of p21, p27, and decrease of cycline D1, which occurred in parallel with G0/G1 phase arrest. Autophagy induction was also observed in the combination treatment. Importantly, combining AsIII with Tetra exhibited a synergistic inhibitory effect on the expression level of survivin. Furthermore, enhanced As[i] along with synergistic cytotoxicity was observed in MCF-7 cells treated with AsIII combined with Tetra or Ko134, an inhibitor of breast cancer resistance protein (BCRP), suggesting that Tetra or the BCRP inhibitor probably intervened in the occurrence of resistance to arsenic therapy by enhancing the As[i] via modulation of multidrug efflux transporters. These results may provide a rational molecular basis for the combination regimen of AsIII plus Tetra, facilitating the development of AsIII-based anticancer strategies and combination therapies for patients with solid tumors, especially breast cancer.

Therapeutic Potential of Delivering Arsenic Trioxide into HPV-Infected Cervical Cancer Cells Using Liposomal Nanotechnology

Arsenic trioxide (ATO) has been used successfully to treat acute promyelocytic leukaemia, and since this discovery, it has also been researched as a possible treatment for other haematological and solid cancers. Even though many positive results have been found in the laboratory, wider clinical use of ATO has been compromised by its toxicity at higher concentrations. The aim of this study was to explore an improved method for delivering ATO using liposomal nanotechnology to evaluate whether this could reduce drug toxicity and improve the efficacy of ATO in treating human papillomavirus (HPV)-associated cancers. HeLa, C33a, and human keratinocytes were exposed to 5 μm of ATO in both free and liposomal forms for 48 h. The stability of the prepared samples was tested using inductively coupled plasma optical emission spectrometer (ICP-OES) to measure the intracellular arsenic concentrations after treatment. Fluorescent double-immunocytochemical staining was carried out to evaluate the protein expression levels of HPV-E6 oncogene and caspase-3. Cell apoptosis was analysed by flow cytometry. Results showed that liposomal ATO was more effective than free ATO in reducing protein levels of HPV-E6 and inducing cell apoptosis in HeLa cells. Moreover, lower toxicity was observed when liposomal-delivered ATO was used. This could be explained by lower intracellular concentrations of arsenic. The slowly accumulated intracellular ATO through liposomal delivery might act as a reservoir which releases ATO gradually to maintain its anti-HPV effects. To conclude, liposome-delivered ATO could protect cells from the direct toxic effects induced by higher concentrations of intracellular ATO. Different pathways may be involved in this process, depending on local architecture of the tissues and HPV status.

Differential sensitivity of p44/p42-MAPK- and PI3K/Akt-targeted neuroblastoma subtypes to arsenic trioxide

PI3K/Akt and MAPK/ERK pathways are differentially activated in neuroblastoma (NB) cell types. In an effort to enhance the effectiveness of the NB treatment, we designed experiments to evaluate the effects of ATO in combination with PI3K and MEK1/2 specific inhibitors, LY29004 and U0126, respectively, in SK-N-MC and SK-N-BE(2) cell lines. The results indicated that specific inhibition of PI3K and MEK1/2 significantly enhanced antiproliferative and proapoptotic effects of ATO in SK-N-BE(2), but not in SK-N-MC. Furthermore, in SK-N-BE(2), NF-κB activation was significantly suppressed by LY29004+ATO treatments as compared with ATO alone, indicating that inhibition of PI3K may enhance anti-neoplastic properties of ATO in I-type NB cells through suppression of NF-κB. Moreover, expressions of c-Myc, Bad, Bax and ATM in SK-N-BE(2) cell line were significantly increased by U0126+ATO treatment as compared to treatment with ATO alone. Expression of telomerase hTERT was almost depleted by U0126+ATO treatment. Regarding the fact that activation of PI3K and MAPK in SK-N-BE(2) is higher than in other NB subtypes, we hypothesize that growth of SK-N-BE(2) cell line is highly dependent on these pathways and inhibition of these pathways may has promise for the treatment of multi-drug resistant I-type NB cells by ATO. However, for successful strategies for the treatment of this heterogeneous tumor, other combinations approaches need to be considered to simultaneously target other NB cells.