The mechanisms on apoptosis by inhibiting VEGF expression in human breast cancer cells

Novel curcumin-based analogues as potential VEGFR2 inhibitors with promising metallic loading nanoparticles: synthesis, biological evaluation, and molecular modelling investigation

VEGFR2 inhibition has been established as a therapeutic approach for managing cancer. A series of curcumin-based analogues were designed, synthesized, and screened for their anticancer activity against MCF-7 and HepG-2 cell lines and WISH normal cells. Compounds 4b, 4d, 4e, and 4f showed potent cytotoxicity against MCF-7 with IC50 values of 0.49, 0.14, 0.01, and 0.32 μM, respectively, compared to curcumin (IC50 = 13.8 μM) and sorafenib (IC50 = 2.13 μM). Interestingly, compound 4e, the most active compound, exhibited potent VEGFR2 inhibition with an IC50 value of 11.6 nM (96.5% inhibition) compared to sorafenib with an IC50 value of 30 nM (94.8% inhibition). Additionally, compound 4e significantly induced apoptotic cell death in MCF-7 cells by 41.1% compared to a control group (0.8%), halting cell division during the G2/M phase by 39.8% compared to the control (21.7%). Molecular docking-coupled dynamics simulations highlighted the bias of the VEGFR2 pocket towards compound 4e compared to other synthesized compounds. Predicting superior binding affinities and relevant interactions with the pocket's key residues recapitulated in vitro findings towards higher inhibition activity for compound 4e. Furthermore, compound 4e with adequate pharmacokinetic and drug-likeness profiles in terms of ADME and safety characteristics can serve as a promising clinical candidate for future lead optimization and development. Notably, 4e-Fe2O3-humic acid NPs exhibited potent cytotoxicity with IC50 values of 2.41 and 13.4 ng mL-1 against MCF-7 and HepG-2 cell lines, respectively. Hence, compound 4e and its Fe2O3-humic acid-NPs could be further developed as promising anti-breast cancer agents.

Exosomes from Adipose-Tissue-Derived Stem Cells Induce Proapoptotic Gene Expression in Breast Tumor Cell Line

Lipofilling is an option for breast reconstruction after tumor resection to avoid the complications of an implant-based reconstruction. Although some concerns exist regarding the oncological safety of tissue rich in mesenchymal stem cells with their proangiogenic and proliferation-supportive properties, there are also reports that adipose-tissue-derived stem cells can exhibit antitumoral properties. We isolated primary adipose-tissue-derived stem cells. Both conditioned medium and exosomes were harvested from the cell culture and used to treat the breast cancer cell line MCF-7. Cell viability, cytotoxicity, and gene expression of MCF-7 cells in response to the indirect co-culture were evaluated. MCF-7 cells incubated with exosomes from adipose-tissue-derived stem cells show reduced cell viability in comparison to MCF-7 cells incubated with adipose-tissue-derived stem-cell-conditioned medium. Expression of proapoptotic genes was upregulated, and expression of antiapoptotic genes was downregulated. The debate about the oncological safety of autologous fat grafting after tumor resection continues. Here, we show that exosomes from adipose-tissue-derived stem cells exhibit some antitumoral properties on breast cancer cell line MCF-7.

Suppressive role of vascular endothelial growth factor on intestinal apoptosis in induced necrotizing enterocolitis in rats

Purpose

Necrotizing enterocolitis (NEC) is a devastating disease that can cause mortality in preterm babies. NEC may develop through an apoptotic pathway that is known to be inhibited by vascular endothelial growth factor (VEGF). This study determined whether VEGF exerted a protective effect against the development of NEC and apoptosis in rats.

Methods

To determine the effect of VEGF in NEC rats, neonatal rats were randomized into 4 groups: the control group, the NEC group, the NEC + intraperitoneal VEGF (50 ng/kg) group (NEC + VEGF IP group), and the NEC + oral VEGF (50 ng/kg) group (NEC + VEGF OR group). NEC was induced by lipopolysaccharide/hypoxia and cold stress. The animals were sacrificed 72 hours later. After laparotomy, we obtained a region of the proximal small bowel from the ileocecal valve about 18 cm in length.

Results

The NEC histological grade, apoptosis histological score, and caspase-3 activity were lower in the NEC + VEGF IP and OR groups than in the NEC group. In the NEC + VEGF IP and OR groups, the messenger RNA expression of apoptotic and inflammatory genes, such as Bax, NF-κB, p53, Fas, FasL, and PAF-R, but not that of Bcl-2, was decreased, as was the Bax/Bcl-2 protein ratio. Histological analysis revealed that the apoptosis-blocking effect of VEGF was more effective in the NEC + VEGF IP group than in the NEC + VEGF OR group.

Conclusion

We identified apoptotic and inflammatory genes to confirm the preventive effect of VEGF pretreatment on NEC in rats. This study presents a novel approach to prevent apoptosis via VEGF pretreatment in rats with lipopolysaccharide/hypoxia-induced NEC.

Dual pH-Responsive and Tumor-Targeted Nanoparticle-Mediated Anti-Angiogenesis siRNA Delivery for Tumor Treatment

Purpose

In order to overcome the biological barriers at all levels and enhance the delivery efficiency of siRNA, we have prepared a multifunctional siRNA delivery system (CHCE/siRNA nanoparticles) through self-assembly of the carboxymethyl chitosan modified with histidine, cholesterol, and anti-EGFR antibody (CHCE).

Methods

The morphology of CHCE/siRNA NPs was detected by dynamic light scattering and scanning electron microscope. In vitro, we assessed the tumor-targeting, cellular uptake, and endosomal escape by flow cytometry and confocal laser scanning microscopy, confirming the CHCE/siRNA NPs functions in gene silencing and cell killing ability. In vivo, we examined the biodistribution of the CHCE/siRNA NPs by the IVIS imaging system and confirmed the therapeutic effect of NPs in the nude-mouse tumor model.

Results

The CHCE/siRNA NPs exhibited nanosized spherical with narrow size distribution. In vitro, the CHCE/siRNA NPs incorporated a dual capability of tumor targeting and pH response that could facilitate cellular bind, cellular uptake, and endosomal escape. The CHCE/siRNA NPs could effectively silence the vascular endothelial growth factor A (VEGFA) to cause cell apoptosis and inhibit proliferation. In vivo, the CHCE/siRNA NPs could target tumor sites to knock down VEGFA and achieve a better anti-tumor effect.

Conclusion

We successfully prepared a novel siRNA delivery system with the double capability of tumor targeting and pH response, which can break through the biological barriers to penetrate deep into tumors and achieve better therapeutic tumor effects, providing a new ideal delivery platform for siRNA.

Discovery of new VEGFR-2 inhibitors based on bis([1, 2, 4]triazolo)[4,3-a:3',4'-c]quinoxaline derivatives as anticancer agents and apoptosis inducers

Herein, a new wave of bis([1, 2, 4]triazolo)[4,3-a:3',4'-c]quinoxaline derivatives have been successfully designed and synthesised. The synthesised derivatives were biologically investigated for their cytotoxic activities against HepG2 and MCF-7. Also, the tested compounds were further examined in vitro for their VEGFR-2 inhibitory activity. The most promising derivative 23j was further investigated for its apoptotic behaviour in HepG2 cell lines using flow cytometric and western-plot analyses. Additional in-silico studies were performed to predict how the synthesised compounds can bind to VEGFR-2 and to determine the drug-likeness profiling of these derivatives. The results revealed that compounds 23a, 23i, 23j, 23l, and 23n displayed the highest antiproliferative activities against the two cell lines with IC50 values ranging from 6.4 to 19.4 µM. Furthermore, compounds 23a, 23d, 23h, 23i, 23j, 23l, 23 m, and 23n showed the highest VEGFR-2 inhibitory activities with IC50 values ranging from 3.7 to 11.8 nM, comparing to sorafenib (IC50 = 3.12 nM). Moreover, compound 23j arrested the HepG2 cell growth at the G2/M phase and induced apoptosis by 40.12% compared to the control cells (7.07%). As well, such compound showed a significant increase in the level of caspase-3 (1.36-fold), caspase-9 (2.80-fold), and BAX (1.65-fold), and exhibited a significant decrease in Bcl-2 level (2.63-fold).

Functional and structural alternations in the choroid plexus upon methamphetamine exposure

Choroid plexus (CP) is the principal source of cerebrospinal fluid. CP can produce and release a wide range of materials including growth factors, neurotrophic factors, etc. all of which play an important role in the maintenance and proper functioning of the brain. Methamphetamine (METH) is a CNS neurostimulant that causes brain dysfunction. Herein, we investigated the potential effects of METH exposure on CP structure and function. Stereological analysis revealed a significant alteration in CP volume, epithelial cells and capillary number upon METH treatment. Electron microscopy exhibited changes in ultrastructure. Moreover, the upregulation of neurotrophic factors such as BDNF and VEGF as well as autophagy and apoptosis gene following METH administration were observed. We also identified several signaling cascades related to autophagy. In conclusion, gene expression changes coupled with structural alterations of the CP in response to METH suggested METH-induced autophagy in CP.

Quercetin and Luteolin Improve the Anticancer Effects of 5-Fluorouracil in Human Colorectal Adenocarcinoma In Vitro Model: A Mechanistic Insight

The aim of this study was to investigate the antitumor effects of quercetin and luteolin combined with 5-Fluorouracil (5-FU) in HT-29 human colorectal cancer cells. Cell viability induced by quercetin, luteolin and combination of these compounds with 5-FU were determined by MTT assay, also Cell death detection Elisa assay and fluorescence microscopy were performed to investigate apoptotic effects. Hu-VEGF Elisa assay was employed to determine the effects of treatments on angiogenesis. Western blot and qRT-PCR analysis were performed to investigate effects on p53, Bax, Bcl-2, p38 MAPK, mTOR, PTEN, and Akt proteins and genes. The results indicated that quercetin, luteolin and combinations of these compounds with 5-FU inhibited the growth of HT 29 cells. Compared to the control, apoptosis were triggered 8.1 and 10.1 fold in HT-29 cells, that treated with quercetin + 5-FU and luteolin + 5-FU, respectively. VEGF amount significantly decreased by combined treatments. qRT-PCR and western blot results demonstrated that quercetin, luteolin and the combinations of these flavonoids with 5-FU, modulate the apoptotic pathways in HT-29 cells. The increase in p53, Bax, p38 MAPK, and PTEN gene expression levels compared to the control group was 1.71, 1.42, 3.26, and 3.29-fold with 5-FU + L treatment, respectively, while this increase was 8.43, 1.65, 3.55, and 3.54-fold with 5-FU + Q treatment, respectively. In addition, when the anti-apoptotic Bcl-2, mTOR, and Akt gene expression levels were normalized as 1 in the control group, they were 0.28, 0.41, and 0.22 with 5-FU + L treatment, and 0.32, 0.46, and 0.39, respectively, with 5-FU + Q treatment. These findings suggested that quercetin and luteolin synergistically enhanced the anticancer effect of 5-FU in HT 29 cells and may therefore minimize the toxic effects of 5-FU in the clinical treatment of colorectal cancer.

Evaluation of Variances in VEGF-A-D and VEGFR-1-3 Expression in the Ishikawa Endometrial Cancer Cell Line Treated with Salinomycin and Anti-Angiogenic/Lymphangiogenic Effect

BACKGROUND

In cancer, an excessive and uncontrolled process of creating new blood and lymphatic vessels that play a key role in the metastasis process can be observed. The Vascular Endothelial Growth Factor (VEGF-A,-B,-C,-D) family together with their specific receptors (VEGFR-1,-2,- 3) plays a key role in these processes, therefore, it would be reasonable to determine the correct pattern of their expression.

OBJECTIVES

The study aimed to assess the use of salinomycin as an anti-angiogenic and anti-lymphangiogenic drug during endometrial cancer by examining changes in the expression pattern of VEGF-A, VEGF-B, VEGF-C, VEGF-D, VEGFR-1, VEGFR-2 and VEGFR-3 depending on the treatment period of the Ishikawa endometrial cancer cells with salinomycin in comparison to the control culture.

MATERIALS AND METHODS

To determine how influential salinomycin was on the expression of both mRNAs, 1 μM of the drug was added to the cell culture and then it was cultured all together for 12, 24 and 48 hour periods. The cells that made up the control culture were not treated with salinomycin. To determine the changes in the expression profile of the selected genes, we used the microarray, techniques: RTqPCR and ELISA (p<0.05).

RESULTS

For all isoforms of VEGF-A-D as well as receptors of VEGFR-1-3, a decrease in expression under the influence of salinomycin was noted. For VEGF-A and VEGFR-1, the difference in the expression between the culture treated with salinomycin in comparison to the control was statistically significant (p=0.0004). In turn, for VEGF-B, the difference between the culture exposed for 24 hours in comparison to the control (p=0.00000) as well as the comparison between H48 vs. C (p=0.00000) was statistically significant. In reference to VEGF-C, VEGFR-2 and VEGFR-3, the statistical analysis showed the significant difference in expression between the culture incubated with the drug for 12, 24 and 48 hours in comparison to the control as well as between the selected times. For all of these comparisons, p=0.00000 was utilized.

CONCLUSION

Salinomycin changes the expression pattern of VEGF-A, VEGF-B, VEGF-C, VEGF-D, VEGFR-1, VEGFR-2, and VEGFR-3 in endometrial cancer cells. The obtained results suggest that salinomycin might exert the effect via VEGF signaling pathways.

Targeting the Dysfunctional Placenta to Improve Pregnancy Outcomes Based on Lessons Learned in Cancer

In recent decades, our understanding of the disrupted mechanisms that contribute to major obstetrical diseases, including preeclampsia, fetal growth restriction, preterm birth, and gestational diabetes, has increased exponentially. Common to many of these obstetric diseases is placental maldevelopment and dysfunction; the placenta is a significant component of the maternal-fetal interface involved in coordinating, facilitating, and regulating maternal and fetal nutrient, oxygen and waste exchange, and hormone and cytokine production. Despite the advances in our understanding of placental development and function, there are currently no treatments for placental maldevelopment and dysfunction. However, given the transient nature and accessibility from the maternal circulation, the placenta offers a unique opportunity to develop targeted therapeutics for routine obstetric practices. Furthermore, given the similar developmental paradigms between the placenta and cancer, there is an opportunity to appropriate current knowledge from advances in targeted therapeutics in cancer treatments. In this review, we highlight the similarities between early placental development and cancer and introduce a number of targeted therapies currently being explored in cancer and pregnancy. We also propose a number of new effectors currently being targeted in cancer research that have the potential to be targeted in the development of treatments for pregnancy complications. Finally, we describe a method for targeting the placenta using nonviral polymers that are capable of delivering plasmids, small interfering RNA, and other effector nucleic acids, which could ultimately improve fetal and maternal outcomes from complicated pregnancies.

siRNA and chemotherapeutic molecules entrapped into a redox-responsive platform for targeted synergistic combination therapy of glioma

Vascular endothelial growth factor (VEGF) has been implicated as the key regulator of tumor neovascularization. RNAi interference plays a critical role on down-regulation of VEGF, while single VEGF inhibition could not completely suppress angiogenesis and tumor growth; the effect of siRNA is temporary. To improve glioma therapy efficacy, an angiopep-2 (Ap) modified redox-responsive glycolipid-like copolymer co-delivering siVEGF and paclitaxel (PTX), termed as Ap-CSssSA/P/R complexes, was developed in this study. Ap modification significantly enhanced the distribution of Ap-CSssSA in glioma cells both in vitro and in vivo. Ap-CSssSA/P/R complexes could simultaneously deliver siVEGF and PTX into tumor cells, exhibiting great superiority in glioma growth suppression via receptor-mediated targeting delivery and cell apoptosis, accompanied with an obvious inhibition of neovascularization induced by VEGF gene silencing. The present study indicated that the combination delivery of siVEGF and PTX via Ap-modified copolymeric micelles presented a promising and safe platform for glioma targeted therapeutics.

Cleaved Caspase-3 Transcriptionally Regulates Angiogenesis-Promoting Chemotherapy Resistance

Caspases are well known for their role in apoptosis. Recently, nonapoptotic roles of caspases have been identified, however, these noncanonical roles are not well documented and the mechanisms involved are not fully understood. Here, we studied the role of cleaved caspase-3 using human- and mouse-proficient caspase-3 cancer cell lines and human-deficient caspase-3 cancer cells. Cleaved caspase-3 functioned as a transcription factor and directly bound to DNA. A DNA-binding domain was identified in the small subunit of caspase-3 and an active conformation was essential for caspase-3 transcriptional activity. Caspase-3 DNA binding enhanced angiogenesis by upregulating the expression of proangiogenic genes and by activating pathways that promoted endothelial cell activation. Some proapoptotic genes were downregulated in caspase-3-proficient cells. Inhibiting caspase-3 increased the efficacy of chemotherapy and decreased spontaneous tumor development. These data highlight a novel nonapoptotic role of caspase-3 and suggest that cleaved caspase-3 could be a new therapeutic target in cancer. SIGNIFICANCE: These findings report a noncanonical function of caspase-3 by demonstrating its ability to transcriptionally regulate the VEGFR pathway.

Co-delivery of gambogenic acid and VEGF-siRNA with anionic liposome and polyethylenimine complexes to HepG2 cells

Background and objective: The combination of two or more different mechanisms of drugs in the treatment of cancer has become one of the effective methods. The purpose of this study was to successfully prepare a non-viral delivery system that could efficiently co-delivery siRNA and gambogenic acid (GNA) to improve the anti-cancer efficiency in HepG2 cells. Methods: The delivery system was prepared by a two-step method. First, the GNA-anionic liposome took shape by a solvent evaporation method, and then the liposome was bound to the PEI/siRNA complex by electrostatic interaction to form the final carrier system (lipopolyplexes). Agarose gel electrophoresis, MTT, particle size and zeta potential were detected to analyse the lipopolyplexes formation. The transfection efficiency of siRNA was determined by confocal laser scanning microscopy and flow cytometry. Western blotting was used to assess the VEGF protein expression levels of HepG2 cells. The cell apoptosis assay was used to assess the anti-tumour superiority of lipopolyplexes. Results: GNA-PEI/siRNA-liposome (lipopolyplexes) are significantly less cytotoxicity compared to PEI mediated carriers. Simultaneously, the results of flow cytometry and confocal laser scanning microscopy indicated that the lipopolyplexes could successfully carry siRNA into the cytoplasm, and the western-blot result evidence that the delivery system has a potential for VEGF to express down. Also compared with the control group, the results of apoptosis test suggest that the lipopolyplexes can significantly promote cell apoptosis. Conclusion: The delivery system has a potential in the combination of various drugs for cancer therapy in future.

Co-delivery of sorafenib and VEGF-siRNA via pH-sensitive liposomes for the synergistic treatment of hepatocellular carcinoma

Non-viral nanocarrier affords a platform for drug and siRNA combination, the focus of which is to load drug and siRNA into a single carrier, allowing for co-delivery and a synergistic effect at tumour site. In our previous study, pH-sensitive carboxymethyl chitosan-modified liposomes (CMCS-SiSf-CL) were assembled for sorafenib (Sf) and Cy3-siRNA co-loaded. The present study evaluated in vitro and in vivo co-delivery of the co-loaded liposomes. Further, in vitro inhibiting hepatocellular carcinoma of the pH-sensitive sorafenib (Sf) and VEGF-siRNA co-loaded liposomes was discussed. The experimental results demonstrated co-delivery and penetration into 2-dimensional (2D) cultured HepG2 cells, 3-dimensional (3D) cultured HepG2 tumour spheroids and tumour regions of H22 tumour-bearing mice. Compared with free siRNA and single loaded carrier, co-delivery liposomes exhibited enhanced VEGF downregulating effect, inducing cell early apoptosis. Therefore, the CMCS-SiSf-CL delivery system can lay the foundation for the co-delivery systems development and provide new area for HCC therapy.

Bevacizumab in metastatic small-bowel adenocarcinoma: A systematic review and meta-analysis

Cancers of the small bowel could account for less than 5% of all gastrointestinal malignancies. Of these tumors, adenocarcinomas were the major histologic subtype and generally carried a poor prognosis. High expression of vascular epithelial growth factor (VEGF) could be seen in small bowel adenocarcinomas. A systematic review was conducted here to determine if bevacizumab, a recombinant humanized antibody against VEGF, could offer clinical benefit among patients with metastatic small bowel adenocarcinoma when combined with chemotherapy. A search for relevant published and unpublished studies was performed using PubMed, ScienceDirect, Google Scholar, the American Society of Clinical Oncology meetings library, ClinicalTrials.gov, and ISRCTN registry. Information on study design, methods, intervention, and outcomes were extracted from selected eligible studies. Methodological quality was then assessed using the Newcastle-Ottawa Scale. There was a significant improvement in mean overall survival with the addition of bevacizumab with chemotherapy versus chemotherapy alone. The use of bevacizumab with chemotherapy, likewise improved progression-free survival and objective response rate compared to chemotherapy alone. Continued use of bevacizumab beyond first progression also appeared to show benefit. The conduct of prospective controlled studies by consortia to offset the rarity of small bowel adenocarcinomas could further elucidate the efficacy of bevacizumab in the treatment of this disease.

The suppressive effect of co-inhibiting PD-1 and CTLA-4 expression on H22 hepatomas in mice

Objective

We investigated the suppressive effect of siRNA-mediated co-inhibition of PD-1 and CTLA-4 expression on H22 hepatomas in mice.

Methods

Murine H22 cells were cultured in vivo in ICR mice. An allograft tumor model was also established in another ICR mouse group. The tumor-bearing mice were randomly divided into four groups: control, single PD-1 siRNA, single CTLA-4 siRNA, and double PD-1 + CTLA-4 siRNAs. The survival time and physiological condition of the mice were observed after the injection of the siRNAs and placebo. The volume and weight of the solid tumor were measured to assess the inhibition of the tumor. To assess the effects of siRNAs on mouse immune function, the protein levels of IFN-γ and IL-10 in the blood and PD-L1 in the tumor and liver were determined using ELISA, and the mRNA levels of IFN-γ, PD-L1, PD-1, CTLA-4, IL-6 and Survivin in the tumor, liver and spleen were determined using quantitative RT-PCR. The ratios of Bax and Bcl-2 protein were determined via western blot to analyze the effect of siRNAs on tumor cell apoptosis.

Results

The anti-tumor effect appeared in all groups with siRNA-mediated inhibition. The tumor growth suppression was stronger in the group with double inhibition. The weight and volume of the tumors were significantly lower and the survival rate improved in the three siRNA groups. IFN-γ levels increased but IL-10 levels decreased in the blood of the siRNA group mice compared with the results for the control group. In the tumor and spleen tissue, the IFN-γ levels significantly increased, but in the liver tissue they significantly decreased in the three siRNA groups. The results of quantitative RT-PCR showed that the mRNAs for PD-1 and CTLA-4 were downregulated in spleen tissue in the three siRNA groups, while the PD-L1 mRNA and protein levels increased significantly in the tumor, but decreased in the liver. Survivin and IL-6 mRNA levels decreased in the tumor. Western blot results showed that ratio of Bax and Bcl-2 had significantly increased. These results indicated that downregulating PD-1 and CTLA-4 could increase the body’s immune response and promote apoptosis of tumor cells.

Conclusion

Co-inhibiting the expressions of PD-1 and CTLA-4 can effectively suppress the growth of H22 hepatoma and promote the apoptosis of tumor cells in mice. Blocking PD-1 and CTLA-4 can improve the vitality of T cells, and improve the immune environment and response.

Therapeutic Potency of Nanoformulations of siRNAs and shRNAs in Animal Models of Cancers

RNA Interference (RNAi) has brought revolutionary transformations in cancer management in the past two decades. RNAi-based therapeutics including siRNA and shRNA have immense scope to silence the expression of mutant cancer genes specifically in a therapeutic context. Although tremendous progress has been made to establish catalytic RNA as a new class of biologics for cancer management, a lot of extracellular and intracellular barriers still pose a long-lasting challenge on the way to clinical approval. A series of chemically suitable, safe and effective viral and non-viral carriers have emerged to overcome physiological barriers and ensure targeted delivery of RNAi. The newly invented carriers, delivery techniques and gene editing technology made current treatment protocols stronger to fight cancer. This review has provided a platform about the chronicle of siRNA development and challenges of RNAi therapeutics for laboratory to bedside translation focusing on recent advancement in siRNA delivery vehicles with their limitations. Furthermore, an overview of several animal model studies of siRNA- or shRNA-based cancer gene therapy over the past 15 years has been presented, highlighting the roles of genes in multiple cancers, pharmacokinetic parameters and critical evaluation. The review concludes with a future direction for the development of catalytic RNA vehicles and design strategies to make RNAi-based cancer gene therapy more promising to surmount cancer gene delivery challenges.

RNAi-mediated gene silencing of vascular endothelial growth factor C suppresses growth and induces apoptosis in mouse breast cancer in vitro and in vivo

Vascular endothelial cell growth factor (VEGF)-C promotes tumorigenesis by allowing lymph node metastasis and lymphangiogenesis, among other actions. RNA interference (RNAi) is a novel technique for suppressing target gene expression and may increase the effectiveness of cancer treatments. The present study assessed the influence of VEGF-C RNAi on the apoptosis and proliferation of mouse breast cancer cells in vitro and in vivo. A total of three pairs of small interfering RNA (siRNA) targeting mouse VEGF-C were designed and synthesized prior to transfection into 4T1 cells via a liposomal approach. Reverse transcription polymerase chain reaction, western blot analysis, a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, Hoechst 33258 staining and flow cytometry were performed in vitro to analyze VEGF-C expression, cleaved caspase-3 protein expression and 4T1 cell proliferation and apoptosis. Experiments were also conducted in vivo on BALB/c mice with breast cancer. Tumor weight and volume were measured and the number of apoptotic cells in tumor tissues was assessed by a TUNEL assay. Immunohistochemical assays and an enzyme-linked immunosorbent assay were used to measure the expression of VEGF-C in tumor tissues. The results demonstrated that the three pairs of siRNA, particularly siV2, significantly reduced VEGF-C mRNA and protein levels in 4T1 cells. siV2 was deemed to be the most efficient siRNA and therefore was selected to be used in subsequent experiments. Furthermore, in vitro studies indicated that VEGF-C RNAi significantly decreased cell growth, induced apoptosis and upregulated the expression of cleaved caspase-3 protein. Tumor weight and volume in breast cancer in vivo models was reduced by the intratumoral injection of siV2. Antitumor efficacy was associated with decreased VEGF-C expression and increased induction of apoptosis. The present study therefore indicated that VEGF-C RNAi inhibited mouse breast cancer growth in vitro and in vivo and that it may be a novel targeted therapy for breast cancer.

Deciphering mechanisms of drug sensitivity and resistance to Selective Inhibitor of Nuclear Export (SINE) compounds

BACKGROUND

Exportin 1 (XPO1) is a well-characterized nuclear export protein whose expression is up-regulated in many types of cancers and functions to transport key tumor suppressor proteins (TSPs) from the nucleus. Karyopharm Therapeutics has developed a series of small-molecule Selective Inhibitor of Nuclear Export (SINE) compounds, which have been shown to block XPO1 function both in vitro and in vivo. The drug candidate, selinexor (KPT-330), is currently in Phase-II/IIb clinical trials for treatment of both hematologic and solid tumors. The present study sought to decipher the mechanisms that render cells either sensitive or resistant to treatment with SINE compounds, represented by KPT-185, an early analogue of KPT-330.

METHODS

Using the human fibrosarcoma HT1080 cell line, resistance to SINE was acquired over a period of 10 months of constant incubation with increasing concentration of KPT-185. Cell viability was assayed by MTT. Immunofluorescence was used to compare nuclear export of TSPs. Fluorescence activated cell sorting (FACS), quantitative polymerase chain reaction (qPCR), and immunoblots were used to measure effects on cell cycle, gene expression, and cell death. RNA from naïve and drug treated parental and resistant cells was analyzed by Affymetrix microarrays.

RESULTS

Treatment of HT1080 cells with gradually increasing concentrations of SINE resulted in >100 fold decrease in sensitivity to SINE cytotoxicity. Resistant cells displayed prolonged cell cycle, reduced nuclear accumulation of TSPs, and similar changes in protein expression compared to parental cells, however the magnitude of the protein expression changes were more significant in parental cells. Microarray analyses comparing parental to resistant cells indicate that a number of key signaling pathways were altered in resistant cells including expression changes in genes involved in adhesion, apoptosis, and inflammation. While the patterns of changes in transcription following drug treatment are similar in parental and resistant cells, the extent of response was more robust in the parental cells.

CONCLUSIONS

These results suggest that SINE resistance is conferred by alterations in signaling pathways downstream of XPO1 inhibition. Modulation of these pathways could potentially overcome the resistance to nuclear export inhibitors.

Critical role of CDK11(p58) in human breast cancer growth and angiogenesis

Background

A capillary network is needed in cancer growth and metastasis. Induction of angiogenesis represents one of the major hallmarks of cancer. CDK11^p58, a Ser/Thr kinase that belongs to the Cell Division Cycle 2-like 1 (CDC2L1) subfamily is associated with cell cycle progression, tumorigenesis, sister chromatid cohesion and apoptotic signaling. However, its role in breast cancer proliferation and angiogenesis remains unclear.

Methods

Tumorigenicity assays and blood vessel assessment in athymic mice were used to assess the function of CDK11^p58 in tumor proliferation and angiogenesis. CCK-8 assay was used to detect breast cancer cell growth. Immunohistochemistry was used to detect the expression of vascular endothelial growth factor (VEGF), CD31 and CD34 in CDK11 positive patient breast cancer tissues. Dual-Luciferase array was used to analyze the function of CDK11^p58 in the regulation of VEGF promoter activity. Western blot was used to detect related protein expression levels.

Results

CDK11^p58 inhibited breast cancer growth and angiogenesis in breast cancer cells and in nude mice transplanted with tumors. Immunohistochemistry confirmed that CDK11^p58 was negatively associated with angiogenesis-related proteins such as VEGF, CD31 and CD34 in breast cancer patients. Real-time PCR and dual-luciferase assay showed CDK11^p58 inhibited the mRNA levels of VEGF and the promoter activity of VEGF. As CDK11^p58 is a Ser/Thr kinase, the kinase-dead mutant failed to inhibit VEGF mRNA and promoter activity. Western blot analysis showed the same pattern of related protein expression. The data suggested angiogenesis inhibition was dependent on CDK11^p58 kinase activity.

Conclusion

This study indicates that CDK11^p58 inhibits the growth and angiogenesis of breast cancer dependent on its kinase activity.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1698-7) contains supplementary material, which is available to authorized users.

Enhanced Therapeutic siRNA to Tumor Cells by a pH-Sensitive Agmatine-Chitosan Bioconjugate

Charge-conversional naturally occurring chitosan-agmatine bioconjugates are prepared by dimethylmaleic anhydride (DMA) modification and the nucleophilic reaction between tosyl of tosylated chitosan and primary amine of agmatine. These bioconjugates (CS-DM-Agm) are shown to condense siRNA into nanocomplexes, which are stable in the presence of serum at physical pH values. Furthermore, the surface charge of complexes can tune from negative to positive while pH is changed to weak acid tumor micromilieu, thus facilitating the target cancer cell internalization in resisting serum adsorption. More importantly, this smart biogenic system shows remarkable gene silencing efficiency and a high apoptotic rate of tumor cells both in vitro and in vivo, indicating its great potential for cancer therapy.

Prolyl-4-hydroxylase 2 enhances hypoxia-induced glioblastoma cell death by regulating the gene expression of hypoxia-inducible factor-α

Oxygen deprivation (hypoxia) is a common feature of solid tumors in advanced stages. The primary cellular transcriptional responses to hypoxia are mainly mediated by the transcription factor hypoxia-inducible factor (HIF). HIF consists of an oxygen-labile α-subunit (HIF-1α, -2α) and a stable β-subunit (ARNT). Prolyl-4-hydroxylase 2 (PHD2) is known as an important mediator of the oxygen-dependent degradation of HIF-α subunits. As HIF-α subunits are not confirmed to be the only substrates of PHD2, it is unknown whether PHD2 regulates HIF-1α and HIF-2α by interacting with other intracellular molecules. In this study, we found that in the glioblastoma cells, PHD2 maintains the gene expression of HIF-1α in dependence of nuclear factor κB and suppresses the gene expression of HIF-2α through HIF-1α. The PHD2-mediated degradation of HIF-1α and HIF-2α seems less important. Furthermore, PHD2 enhances hypoxia-induced glioblastoma cell death by modulating the expression of the HIF target genes glucose transporter 1, vascular endothelial growth factor-A and Bcl-2 binding protein 3. Our findings show that PHD2 inhibits the adaptation of glioblastoma cells to hypoxia by regulating the HIF-α subunits in a non-canonical way. Modulation of PHD2 activity might be considered as a new way to inhibit glioblastoma progression.

Impact of tumor removal on the systemic oxidative profile of patients with breast cancer discloses lipid peroxidation at diagnosis as a putative marker of disease recurrence

BACKGROUND

Recent studies have suggested a regulatory role for some of the metabolites derived from oxidative stress in breast cancer. In this way, cancer-induced oxidative changes could modify the breast environment and potentially trigger systemic responses that may affect disease prognosis and recurrence. In this study, we investigated the systemic oxidative profile of women with early breast cancer bearing the primary tumor and after tumor withdrawal, and its long-term implications.

PATIENTS AND METHODS

Plasma samples were collected at diagnosis, and the systemic oxidative profile was determined by evaluating the lipid peroxidation, total antioxidant capacity of plasma (TRAP), malondialdehyde (MDA), protein carbonylation, and hydroperoxides. Nitric oxide, vascular endothelial growth factor (VEGF), and tumor necrosis factor alpha (TNF-α) levels were further measured. We also evaluated the impact of the oxidative profiling at diagnosis on disease recurrence in a 5-year follow-up.

RESULTS

Enhanced oxidative stress was detected in patients bearing the primary tumors, characterized by high lipid peroxidation, TRAP consumption, high carbonyl content, and elevated VEGF and TNF-α levels. After tumor removal, the systemic oxidative status presented attenuation in lipid peroxidation, MDA, VEGF, and TNF-α. The 5-year recurrence analysis indicated that all patients who recidivated presented high levels of lipid peroxidation measured by chemiluminescence at diagnosis.

CONCLUSIONS

Our data suggest that the presence of the primary tumor is indicative of the systemic pro-oxidant status of breast cancer and demonstrates a role for lipid peroxidation in disease recurrence, highlighting the need for a metabolic follow-up of patients with cancer at diagnosis before tumor removal.

The effects of ranibizumab on surgically induced endometriosis in a rat model: a preliminary study

OBJECTIVE

To examine the effect of ranibizumab on surgically induced endometriosis in rat models.

STUDY DESIGN

Endometrial tissue was implanted onto the abdominal peritoneum of 20 rats that were randomized into 2 groups. The rats in group 1 (n = 9) were given 0.6 mg/kg ranibizumab on the 1st and 14th days after the second operation. The rats in group 2 (control group, n = 9) received no medication. All the rats were observed for a total of 28 days.

RESULTS

At the end of the treatment, the mean volume and weight of the explants in group 1 (11.49 ± 6.87 mm(3) and 36.61 ± 17.84 mg) were significantly lower than that of the control group (190.6 ± 177.4 mm(3) and 187.3 ± 174.5 mg; both Ps < .01). Mean epithelial histologic scores were significantly lower in group 1 (1.11 ± 0.78) than that of the control group (2.33 ± 0.71; P < .01). When compared with the control group, vascular endothelial growth factor (VEGF) immunoreactivities in group 1 showed statistically significant reductions (1.67 ± 0.50; 2.67 ± 0.50; P < .01).

CONCLUSION

Ranibizumab has significantly regressed the size of the endometriotic implants and caused atrophy of these lesions in rats by decreasing explant levels of VEGF.

Tubular network formation by adriamycin-resistant MCF-7 breast cancer cells is closely linked to MMP-9 and VEGFR-2/VEGFR-3 over-expressions

We have previously demonstrated that matrix metalloproteinase-9 (MMP-9) is critical for breast cancer cell migration and is necessary but not sufficient for tubular network formation. Given the important angiogenic activity of vascular endothelial growth factor (VEGF), we investigate here its possible contribution in tubular network formation and its link with MMP-9. Exposure of resistant epithelial breast cancer cells (rMCF-7) to Avastin, a VEGF neutralising antibody, suppresses tubular network formation but not cell migration. However, their exposure to MMP-9 inhibitor markedly decreases both parameters. Besides, the addition of exogenous VEGF or MMP-9 alone or in combination to sensitive parental cells (sMCF-7) or rMCF-7 cells enhances tubular network formation by rMCF-7 cells but not by sMCF-7 cells. The evaluation of the expression levels of VEGF receptor (VEGFR) subtypes shows that sMCF-7 cells express only small quantities of VEGFR-2 and VEGFR-3 compared with rMCF-7 cells that express strong quantities. However, treatment of sMCF-7 cells by phorbol 12-myristate 13-acetate (PMA), a PKC activator, induces both tubular network formation and VEGFR-2/VEGFR-3 over-expressions. Interestingly, exposure of rMCF-7 cells or PMA-treated sMCF-7 cells to the specific inhibitors of VEGFR-2 and VEGFR-3 reduces markedly the tubular network formation. Together, our results demonstrate that the proteolytic enzyme MMP-9 promotes rMCF-7 cell migration and, consequently, tubular network formation through VEGFR-2/ VEGFR-3 activation. Understanding of mechanisms involved in vasculogenic mimicry and cell migration related to MMP-9 and VEGF may open new opportunities to improve cancer therapy.

Nanoparticle-mediated delivery of shRNA.VEGF-a plasmids regresses corneal neovascularization

PURPOSE

To determine the efficacy of a plasmid containing a small hairpin RNA expression cassette (pSEC.shRNA) against VEGF-A-loaded poly(lactic co-glycolic acid) nanoparticles (PLGA NPs) in the sustained regression of murine corneal neovascularization.

METHODS

PLGA nanoparticles were loaded with pSEC.shRNA.VEGF-A plasmids using the double emulsion-solvent evaporation method. KNV was induced in BALB/c mice by mechanical-alkali injury. Four weeks after induction of KNV, the mice were randomly divided to receive one of four treatments intrastromally: pSEC.shRNA.VEGF-A PLGA NPs (2 μg plasmid); naked pSEC.shRNA.VEGF-A plasmid only (2 μg plasmid); control blank PLGA NPs (equivalent dry weight of NPs); and vehicle. Two and five days after intervention, corneas were harvested to determine VEGF-A gene and protein expression using reverse transcriptase polymerase chain reaction and ELISA, respectively. Four weeks after intervention, corneas were photographed, mice sacrificed, and the corneal whole mounts were immunostained for CD31 (panendothelial cell marker). Immunofluorescence microscopy was performed and the neovascular area was quantitated.

RESULTS

VEGF-A mRNA (49.6 ± 12.4 vs. 82.9 ± 6.0%, P < 0.01) and protein (4.0 ± 5.2 vs. 20.0 ± 7.5 ρg VEGF-A/mg total protein, P < 0.05) expression were significantly reduced in pSEC.shRNA.VEGF-A PLGA NP-treated corneas as compared with control blank NP. The pSEC.shRNA.VEGF-A PLGA NP-treated corneas showed significant regression in the mean fractional areas of KNV (0.125 ± 0.042; 12.5%, P <0.01) compared with both naked plasmid only (0.283 ± 0.004; 28.3%) and control (blank NPs = 0.555 ± 0.072, 55.5%) at 4 weeks post-treatment.

CONCLUSIONS

The pSEC.shRNA.VEGF-A-loaded PLGA NPs are an effective, nonviral, nontoxic, and sustainable form of gene therapy for the regression of murine KNV.

Inhibition of breast cancer cell growth and invasiveness by dual silencing of HER-2 and VEGF

Overexpression of HER-2 accounts for approximately 25% of all breast cancer cases, while 87.7% of HER-2 positive breast cancers are associated with upregulated VEGF. The objective of this study is to explore the combination therapy of blocking HER-2 and VEGF expressions simultaneously using siRNA. This is the first report to examine the effect of dual silencing of HER-2 and VEGF genes on tumor growth and invasiveness. We have designed nine HER-2 siRNAs and ten VEGF siRNAs, and identified potent siRNA which can silence the target gene up to 75-83.5%. The most potent HER-2 and VEGF siRNAs were used to conduct functional studies in HER-2 positive breast cancer cells. Tumor invasiveness properties including cell morphology change, in vitro migration, cell spreading, and adhesion to ECM were evaluated. In addition, cell proliferation and apoptosis were examined after the siRNA treatment. Our data demonstrated for the first time that HER-2 siRNA could inhibit cell migration and invasion abilities. Combination of HER-2 and VEGF siRNAs exhibited synergistic silencing effect on VEGF. Both HER-2 siRNA and VEGF siRNA showed significant inhibition on cell migration and proliferation. HER-2 siRNA also demonstrated dramatic suppression on cell spreading and adhesion to ECM, as well as induction of apoptosis. Dual silencing of HER-2 and VEGF exhibited significant cell morphology change, and substantial suppression on migration, spreading, cell adhesion, and proliferation. Our observations suggested that HER-2 positive breast cancer may be more effectively treated by dual inhibition of HER-2 and VEGF gene expressions using siRNA.