Hesperetin activates the Notch1 signaling cascade, causes apoptosis, and induces cellular differentiation in anaplastic thyroid cancer

Regulation of iodine-glucose flip-flop in SW1736 anaplastic thyroid cancer cell line

AIMS AND BACKGROUND

The alternative manner of iodide and glucose uptake found in different types of thyroid cancer, referred to flip-flop. ATC cells indicate low iodide uptake and high glucose uptake, which lack the morphology and genetic characteristics of well-differentiated tumors and become increasingly invasive. Importance placed on the discovery of innovative multi-targeted medicines to suppress the dysregulated signaling in cancer. In this research, we aimed to clarify molecular mechanism of Rutin as a phytomedicine on anaplastic thyroid cancer cell line based on iodide and glucose uptake.

MATERIAL METHODS

The MTT test was employed to test cell viability. Iodide uptake assay was performed using a spectrophotometric assay to determine iodide uptake in SW1736 cells based on Sandell-Kolthoff reaction. For glucose uptake detection, ''GOD-PAP'' enzymatic colorimetric assay was applied to measure the direct glucose levels inside of the cells. Determination of NIS, GLUT1 and 3 mRNA expression in SW1736 cells was performed by qRT-PCR. Determination of NIS, GLUT1 and 3 protein levels in SW1736 cells was performed by western blotting.

RESULTS

According to our results, Rutin inhibited the viability of SW1736 cells in a time- and dose-dependent manner. Quantitative Real-time RT-PCR analysis exposed that NIS mRNA levels were increased in Rutin treated group compared to the control group. Accordingly, western blot showed high expression of NIS protein and low expression of GLUT 1 and 3 in Rutin treated SW1736 cell line. Rutin increased iodide uptake and decreased glucose uptake in thyroid cancer cell line SW1736 compared to control group.

CONCLUSION

Multiple mechanisms point to Rutin's role as a major stimulator of iodide uptake and inhibitor of glucose uptake, including effects at the mRNA and protein levels for both NIS and GLUTs, respectively. Here in, we described the flip-flop phenomenon as a possible therapeutic target for ATC. Moreover, Rutin is first documented here as a NIS expression inducer capable of restoring cell differentiation in SW1736 cell line. It also be concluded that GLUTs as metabolic targets can be blocked specifically by Rutin for thyroid cancer prevention and treatment.

Promising Approaches in Plant-Based Therapies for Thyroid Cancer: An Overview of In Vitro, In Vivo, and Clinical Trial Studies

Thyroid cancer, particularly undifferentiated tumors, poses a significant challenge due to its limited response to standard therapies. The incidence of thyroid cancer, predominantly differentiated carcinomas, is on the rise globally. Anaplastic thyroid carcinoma (ATC), though rare, is highly aggressive and challenging to treat. Therefore, this study aimed to collect data and explore alternative treatments, focusing on the efficacy of photodynamic therapy (PDT) combined with natural compounds as well as the potential role of phytochemicals, including quercetin, kaempferol, apigenin, genistein, daidzein, naringenin, hesperitin, anthocyanidins, epigallocatechin gallate (EGCG), resveratrol, ellagic acid, ferulic acid, caffeic acid, curcumin, saponins, ursolic acid, indole-3-carbinol (I3C), capsaicin, and piperine in thyroid cancer treatment. PDT, utilizing sensitizers activated by tumor-directed light, demonstrates promising specificity compared to traditional treatments. Combining PDT with natural photosensitizers, such as hypericin and genistein, enhances cytotoxicity against thyroid carcinoma cells. This literature review summarizes the current knowledge on phytochemicals and their anti-proliferative effects in in vitro and in vivo studies, emphasizing their effectiveness and mechanism of action as a novel therapeutic approach for thyroid cancers, especially those refractory to standard treatments.

Flavonoids as emerging notch signaling pathway modulators in cancer

Notch signaling is an evolutionary conserved pathway important for the developmental processes and implicated in the tumor formation. Notch signaling pathway (NSP) inhibitors have been tested in clinical trials alone or in combination with the chemotherapy but none got clinical approval due to severe toxicity in patients. Flavonoids inhibit NSP by inhibiting notch receptor cleavage and/or inhibiting transcriptional regulation by Notch intracellular domain (NICD). Interestingly, some flavonoids are reported to inhibit NSP by mediating the microRNA expression. NSP inhibitory flavonoid(s) in combination with standard therapy is might be an effective strategy in cancer treatment.

Hepatocyte CD36 protects mice from NASH diet-induced liver injury and fibrosis via blocking N1ICD production

BACKGROUND & AIMS

Fatty acid translocase CD36 (CD36/FAT) is a widely expressed membrane protein with multiple immuno-metabolic functions. Genetic CD36 deficiency is associated with increased risk of metabolic dysfunction-associated fatty liver disease (MAFLD) in patients. Liver fibrosis severity mainly affects the prognosis in patients with MAFLD, but the role of hepatocyte CD36 in liver fibrosis of MAFLD remains unclear.

METHODS

A high-fat high-cholesterol diet and a high-fat diet with high-fructose drinking water were used to induce nonalcoholic steatohepatitis (NASH) in hepatocyte-specific CD36 knockout (CD36LKO) and CD36flox/flox (LWT) mice. Human hepG2 cell line was used to investigate the role of CD36 in regulating Notch pathway in vitro.

RESULTS

Compared to LWT mice, CD36LKO mice were susceptible to NASH diet-induced liver injury and fibrosis. The analysis of RNA-sequencing data revealed that Notch pathway was activated in CD36LKO mice. LY3039478, an inhibitor of γ-secretase, inhibited Notch1 protein S3 cleavage and Notch1 intracellular domain (N1ICD) production, alleviating liver injury and fibrosis in CD36LKO mice livers. Likewise, both LY3039478 and knockdown of Notch1 inhibited the CD36KO-induced increase of N1ICD production, causing the decrease of fibrogenic markers in CD36KO HepG2 cells. Mechanistically, CD36 formed a complex with Notch1 and γ-secretase in lipid rafts, and hence CD36 anchored Notch1 in lipid rafts domains and blocked Notch1/γ-secretase interaction, inhibiting γ-secretase-mediated cleavage of Notch1 and the production of N1ICD.

CONCLUSIONS

Hepatocyte CD36 plays a key role in protecting mice from diet-induced liver injury and fibrosis, which may provide a potential therapeutic strategy for preventing liver fibrogenesis in MAFLD.

Exploring cell competition for the prevention and therapy of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is characterized by the development of cancer in the esophageal squamous epithelium through a step-by-step accumulation of genetic, epigenetic, and histopathological alterations. Recent studies have demonstrated that cancer-associated gene mutations exist in histologically normal or precancerous clones of the human esophageal epithelium. However, only a small proportion of such mutant clones will develop ESCC, and most ESCC patients develop only one cancer. This suggests that most of these mutant clones are kept in a histologically normal state by neighboring cells with higher competitive fitness. When some of the mutant cells evade cell competition, they become "super-competitors" and develop into clinical cancer. It is known that human ESCC is composed of a heterogeneous population of cancer cells that interact with and influence their environment and neighbors. During cancer therapy, these cancer cells not only respond to therapeutic agents but also compete with each other. Therefore, competition between ESCC cells within the same ESCC tumor is a constantly dynamic process. However, it remains challenging to fine-tune the competitive fitness of various clones for therapeutic benefits. In this review, we will explore the role of cell competition in carcinogenesis, cancer prevention, and therapy, using NRF2, NOTCH pathway, and TP53 as examples. We believe that cell competition is a research area with promising targets for clinical translation. Manipulating cell competition may help improve the prevention and therapy of ESCC.

Notch1 promotes resistance to cisplatin by up-regulating Ecto-5'-nucleotidase (CD73) in triple-negative breast cancer cells

Triple-negative breast cancer (TNBC) is an aggressive molecular subtype that due to lack of druggable targets is treated with chemotherapy as standard of care. However, TNBC is prone to chemoresistance and associates with poor survival. The aim of this study was to explore the molecular mechanisms of chemoresistance in TNBC. Firstly, we found that the mRNA expression of Notch1 and CD73 in cisplatin-treated patient material associated with poor clinical outcome. Further, both were upregulated at the protein level in cisplatin-resistant TNBC cell lines. Overexpression of Notch1 intracellular domain (termed N1ICD) increased expression of CD73, whereas knockdown of Notch1 decreased CD73 expression. Using chromatin immunoprecipitation and Dual-Luciferase assay it was identified that N1ICD directly bound the CD73 promoter and activated transcription. Taken together, these findings suggest CD73 as a direct downstream target of Notch1, providing an additional layer to the mechanisms underlying Notch1-mediated cisplatin resistance in TNBC.

Hesperetin and Capecitabine Abate 1,2 Dimethylhydrazine-Induced Colon Carcinogenesis in Wistar Rats via Suppressing Oxidative Stress and Enhancing Antioxidant, Anti-Inflammatory and Apoptotic Actions

Colon cancer is a major cause of cancer-related death, with significantly increasing rates of incidence worldwide. The current study was designed to evaluate the anti-carcinogenic effects of hesperetin (HES) alone and in combination with capecitabine (CAP) on 1,2 dimethylhydrazine (DMH)-induced colon carcinogenesis in Wistar rats. The rats were given DMH at 20 mg/kg body weight (b.w.)/week for 12 weeks and were orally treated with HES (25 mg/kg b.w.) and/or CAP (200 mg/kg b.w.) every other day for 8 weeks. The DMH-administered rats exhibited colon-mucosal hyperplastic polyps, the formation of new glandular units and cancerous epithelial cells. These histological changes were associated with the significant upregulation of colon Ki67 expression and the elevation of the tumor marker, carcinoembryonic antigen (CEA), in the sera. The treatment of the DMH-administered rats with HES and/or CAP prevented these histological cancerous changes concomitantly with the decrease in colon-Ki67 expression and serum-CEA levels. The results also indicated that the treatments with HES and/or CAP showed a significant reduction in the serum levels of lipid peroxides, an elevation in the serum levels of reduced glutathione, and the enhancement of the activities of colon-tissue superoxide dismutase, glutathione reductase and glutathione-S-transferase. Additionally, the results showed an increase in the mRNA expressions of the anti-inflammatory cytokine, IL-4, as well as the proapoptotic protein, p53, in the colon tissues of the DMH-administered rats treated with HES and/or CAP. The TGF-β1 decreased significantly in the DMH-administered rats and this effect was counteracted by the treatments with HES and/or CAP. Based on these findings, it can be suggested that both HES and CAP, singly or in combination, have the potential to exert chemopreventive effects against DMH-induced colon carcinogenesis via the suppression of oxidative stress, the stimulation of the antioxidant defense system, the attenuation of inflammatory effects, the reduction in cell proliferation and the enhancement of apoptosis.

[Therapy concepts for thyroid carcinoma]

Theranostics via the sodium iodide symporter (NIS) offer a unique option in differentiated thyroid carcinoma. The diagnostic and therapeutic nuclides have similar uptake and kinetics, making the NIS the most important theranostic target in this disease. Radioiodine refractory thyroid carcinomas (RRTC) are characterised by reduced/absent NIS expression, thus eliminating this structure as a theranostic target. Also due to limited therapeutic options, there are approaches to generate new theranostic targets in RRTC, via the expression of somatostatin receptors (SSTR) or the prostate-specific membrane antigen (PSMA), but the current evidence does not yet allow a final evaluation of the prospects of success.

Molecular basis and targeted therapies for radioiodine refractory thyroid cancer

Patients diagnosed with radioiodine refractory thyroid cancer (RAIR-TC) are not amenable to novel ¹³¹ I therapy due to the reduced expression of sodium iodide symporter (Na+/I- symporter, NIS) and/or the impairment of NIS trafficking to the plasma membrane. RAIR-TC patients have a relatively poor prognosis with a mean life expectancy of 3-5 years, contributing to the majority of TC-associated mortality. Identifying RAIR-TC patients and selecting proper treatment strategies remain challenging for clinicians. In this review, we demonstrate the updated clinical scenarios or the so-called "definitions" of RAIR-TC suggested by several associations based on ¹³¹ I uptake ability and tumor response post-¹³¹ I therapy. We also discuss current knowledge of the molecular alterations involved in membrane-localized NIS loss, which provides a preclinical basis for the development of targeted therapies, in particular, tyrosine kinase inhibitors (TKIs), redifferentiation approaches, and immune checkpoint inhibitors.

Hesperetin derivative decreases CCl4 -induced hepatic fibrosis by Ptch1-dependent mechanisms

Hepatic fibrosis (HF), a continuous wound-healing response of the liver to repeated injuries, is characterized by abnormal extracellular matrix (ECM) accumulation. Hepatic stellate cells (HSCs) are considered a major cell type for ECM production. However, recent evidence indicates the lack of effective treatments for HF. Hesperetin, a Traditional Chinese Medicine monomer, has been isolated from the fruit peel of Citrusaurantium L. (Rutaceae). Growing evidence suggests the partial function of hesperetin in HF treatment. A hesperetin derivative (HD) was synthesized in our laboratory to increase the bioavailability and the water solubility of hesperetin. In this study, we detected the functions of HD in a mouse model of CCl₄ -induced HF and transforming growth factor-β1-stimulated HSC-T6 cells, in vivo and in vitro. HD reduced histological damage and CCl₄ -induced HF. Moreover, HD interference was associated with the activation of indicators in HSC-T6 cells, showing that HD is involved in HSCs activation in HF. Mechanistically, the Hedgehog pathway is involved in the HD treatment of HF, and HD may attenuate the aberrant expression of patched1. In conclusion, the studies indicate that HD may function as a potential antifibrotic Traditional Chinese Medicine monomer in HF therapy.

[Therapy concepts for thyroid carcinoma]

Theranostics via the sodium iodide symporter (NIS) offer a unique option in differentiated thyroid carcinoma. The diagnostic and therapeutic nuclides have similar uptake and kinetics, making the NIS the most important theranostic target in this disease. Radioiodine refractory thyroid carcinomas (RRTC) are characterised by reduced/absent NIS expression, thus eliminating this structure as a theranostic target. Also due to limited therapeutic options, there are approaches to generate new theranostic targets in RRTC, via the expression of somatostatin receptors (SSTR) or the prostate-specific membrane antigen (PSMA), but the current evidence does not yet allow a final evaluation of the prospects of success.

Notch signaling pathway: architecture, disease, and therapeutics

The NOTCH gene was identified approximately 110 years ago. Classical studies have revealed that NOTCH signaling is an evolutionarily conserved pathway. NOTCH receptors undergo three cleavages and translocate into the nucleus to regulate the transcription of target genes. NOTCH signaling deeply participates in the development and homeostasis of multiple tissues and organs, the aberration of which results in cancerous and noncancerous diseases. However, recent studies indicate that the outcomes of NOTCH signaling are changeable and highly dependent on context. In terms of cancers, NOTCH signaling can both promote and inhibit tumor development in various types of cancer. The overall performance of NOTCH-targeted therapies in clinical trials has failed to meet expectations. Additionally, NOTCH mutation has been proposed as a predictive biomarker for immune checkpoint blockade therapy in many cancers. Collectively, the NOTCH pathway needs to be integrally assessed with new perspectives to inspire discoveries and applications. In this review, we focus on both classical and the latest findings related to NOTCH signaling to illustrate the history, architecture, regulatory mechanisms, contributions to physiological development, related diseases, and therapeutic applications of the NOTCH pathway. The contributions of NOTCH signaling to the tumor immune microenvironment and cancer immunotherapy are also highlighted. We hope this review will help not only beginners but also experts to systematically and thoroughly understand the NOTCH signaling pathway.

Modulation of Notch Signaling Pathway by Bioactive Dietary Agents

Notch signaling is often aberrantly activated in solid and hematological cancers and regulates cell fate decisions and the maintenance of cancer stem cells. In addition, increased expression of Notch pathway components is clinically associated with poorer prognosis in several types of cancer. Targeting Notch may have chemopreventive and anti-cancer effects, leading to reduced disease incidence and improved survival. While therapeutic agents are currently in development to achieve this goal, several researchers have turned their attention to dietary and natural agents for targeting Notch signaling. Given their natural abundance from food sources, the use of diet-derived agents to target Notch signaling offers the potential advantage of low toxicity to normal tissue. In this review, we discuss several dietary agents including curcumin, EGCG, resveratrol, and isothiocyanates, which modulate Notch pathway components in a context-dependent manner. Dietary agents modulate Notch signaling in several types of cancer and concurrently decrease in vitro cell viability and in vivo tumor growth, suggesting a potential role for their clinical use to target Notch pathway components, either alone or in combination with current therapeutic agents.

Chemotherapeutic potential of hesperetin for cancer treatment, with mechanistic insights: A comprehensive review

BACKGROUND

Cancer has become a significant concern in the medical sector with increasing disease complexity. Although some available conventional treatments are still a blessing for cancer patients, short-and long-term adverse effects and poor efficiency make it more difficult to treat cancer patients, demonstrating the need for new potent and selective anticancer drugs. In search of potent anticancer agents, naturally occurring compounds have always been admired due to their structural diversity, where Hesperetin (HSP) may be one of the potent candidates.

PURPOSE

We aimed to summarize all sources, pharmacological properties, anticancer activities of HSP against numerous cancers types through targeting multiple pathological processes, mechanism of HSP on sensitizing the current anti-cancer agents and other phytochemicals, overcoming resistance pattern and determining absorption, distribution, metabolism, excretion, and toxicity (ADME/Tox).

METHODS

Information was retrieved from PubMed, Science Direct, and Google Scholar based on some key points like Hesperetin, cancer name, anticancer resistance, nanoformulation, and ADME/Tox was determined by in silico approaches.

RESULT

HSP is a phytoestrogen present in citrus fruits in a high concentration (several hundred mg/kg) and exhibited anti-cancer activities through interfering at several pathways. HSP can suppress tumor formation by targeting several cellular proteins such as cell cycle regulatory, apoptosis, metastatic, tyrosine kinase, growth factor receptor, estrogen metabolism, and antioxidant-related protein.HSP has shown remarkable synergistic properties in combination therapy and has been reported to overcome multidrug cancer resistance drugs, leading to an improved defensive mechanism. These anticancer activities of HSP may be due to proper structural chemistry.

CONCLUSION

Overall, HSP showed potential anticancer activities against all cancer and possess better pharmacokinetic properties. So this phytochemical alone or combination with other agents can be an effective alternative drug for cancer treatment.

Repurposing Natural Dietary Flavonoids in the Modulation of Cancer Tumorigenesis: Decrypting the Molecular Targets of Naringenin, Hesperetin and Myricetin

In the past few years flavonoids have been gaining more attention regarding their (still un) exploited anticancer properties. Flavonoids are natural compounds present in fruits, vegetables, and seeds, meaning that they are already present in the daily life of every person, with a described broad-spectrum of pharmacological activities, including anticancer, anti-inflammatory and antioxidant. In the present review we discuss the anticancer activity of three important flavonoids - myricetin (MYR) (flavanol group), hesperetin (HESP) and naringenin (NAR) (flavanone group). Although some mechanisms underlying their activities remain still unclear, they can act as potential inhibitors of key tumorigenic signaling pathways, such as PI3K/Akt/mTOR, p38 MAPK and NF-κB. Simultaneously, they can reset the levels of pro-apoptotic proteins that belong to the Bcl-2 and caspase family and decrease the intracellular levels of ROS and pro-inflammatory cytokines, such as TNF-α, IL-1β and IL-6. Together with their synergetic effect they have the potential to become key elements in the prevention and/or treatment of several types of cancer, with the major improvement to the patient life quality, due to their non-existent toxicity.

Phytochemicals in thyroid cancer: analysis of the preclinical studies

PURPOSE

In the search for novel effective compounds to use in thyroid cancer (TC) unresponsive to current treatment, attention has recently focused on plant-derived compounds with anticancer activity. In this review, we discuss the preclinical studies demonstrating phytochemical activity against thyroid cancer cells.

RESULTS/CONCLUSIONS

In particular, we describe their antiproliferative properties or ability to re-induce iodine retention, thus supporting their potential use as single agents or adjuvants in radioiodine-resistant thyroid cancer treatment.

NOTCH and Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is a deadly disease that requires extensive research on its mechanisms, prevention, and therapy. Recent studies have shown that NOTCH mutations are commonly seen in human ESCC. This chapter summarizes our current understanding of the NOTCH pathway in normal esophagus and in ESCC. In normal esophagus, NOTCH pathway regulates the development of esophageal squamous epithelium, in particular, squamous differentiation. Exposure to extrinsic and intrinsic factors, such as gastroesophageal reflux, alcohol drinking, and inflammation, downregulates the NOTCH pathway and thus inhibits squamous differentiation of esophageal squamous epithelial cells. In ESCC, NOTCH plays a dual role as both a tumor suppressor pathway and an oncogenic pathway. In summary, further studies are warranted to develop NOTCH activators for the prevention of ESCC and NOTCH inhibitors for targeted therapy of a subset of ESCC with activated NOTCH pathway.

Notch Signaling in Thyroid Cancer

Thyroid cancer is the most common malignancy of the endocrine system with a steadily rising incidence. The term "thyroid cancer" encompasses a spectrum of subtypes, namely papillary thyroid cancer, follicular thyroid cancer, anaplastic thyroid cancer, and medullary thyroid cancer. Each subtype differs histopathologically and in degrees of cellular differentiation, which may be in part due to signaling of the Notch pathway. The Notch pathway is an evolutionarily conserved signal transduction mechanism that regulates cell proliferation, differentiation, survival, stem cell maintenance, embryonic and adult development, epithelial-mesenchymal transition, and angiogenesis. Its role in cancer biology is controversial, as it has been shown to play both an oncogenic and tumor-suppressive role in many different types of cancers. This discordance holds true for each subtype of thyroid cancer, indicating that Notch signaling is likely cell type and context dependent. Whether oncogenic or not, Notch signaling has proven to be significantly involved in the tumorigenesis of thyroid cancer and has thus earned interest as a therapeutic target. Advancement in the understanding of Notch signaling in thyroid cancer holds great promise for the development of novel treatment strategies to benefit patients.

The Citrus Flavanone Hesperetin Induces Apoptosis in CTCL Cells via STAT3/Notch1/NFκB-Mediated Signaling Axis

Background:

Hesperetin is a natural compound known for its cholesterol-lowering effect and a wide range of pharmacological activities.

Objectives:

Investigating the potential anticancer activities of Hesperetin in malignant hematolymphoid cell lines HuT78 and MJ, derived from patients with Cutaneous T-Cell Lymphomas (CTCL).

Methods:

The cytotoxic effect of Hesperetin on two different CTCL cell lines, HuT78 and MJ, was assessed by MTS-based colorimetric assay. Apoptosis, cell cycle, ROS (Reactive Oxygen Species) and molecular analysis were performed using flow-cytometry and immunoblotting.

Results:

Hesperetin-treated CTCL cells were arrested at the sub-G1 phase of cell cycle with the concomitant decrease in the expression of the cell cycle regulator protein cyclin B. In addition, the study found that the cellular treatment with Hesperetin caused an induction of apoptosis, which was independent of ROS generation. Hesperetin caused a significant decrease in the expression level of anti-apoptotic protein Bcl-xL and an increase in cleaved caspase-3 and PARP proteins in CTCL cells. Furthermore, Hesperetin treatment in CTCL cells down-regulated the expression of Notch1 and phosphorylation of STAT3 (Tyr705) and inhibited NFκBp65.

Conclusion:

This study highlights the anticancer properties of Hesperetin. Which induces apoptosis in CTCL cells via STAT3/Notch1/NFκB mediated signaling pathway, suggesting that further development of this novel class of flavonoid may contribute to new drug discovery for certain hematolymphoid malignancies.

Therapeutic potential of hesperidin and its aglycone hesperetin: Cell cycle regulation and apoptosis induction in cancer models

BACKGROUND

The ability of cancer cells to divide without restriction and to escape programmed cell death is a feature of the proliferative state. Citrus flavanones are flavonoids with potential multiple anticancer actions, from antioxidant and chemopreventive, to anti-inflammatory, anti-angiogenic, cytostatic and cytotoxic in different cancer models.

PURPOSE

This review aims to summarize the current knowledge on the antiproliferative actions of the citrus flavanones hesperidin (HSD) and hesperetin (HST), with emphasis on cell cycle arrest and apoptosis.

METHODS

Cochrane Library, Scopus, Pubmed and Web of Science collection databases were queried for publications reporting antiproliferative effects of HSD and HST in cancer models.

RESULTS

HSD and HST have been proven to delay cell proliferation in several cancer models. Depending on the compound, dose and cell line studied, different effects have been reported. Cell cycle arrest associated with cytostatic effects has been reported in cells with increased levels of p53 and also cyclin-dependent kinase inhibitors, as well as decreased levels of specific cyclins and cyclin-dependent kinases. Moreover, apoptotic effects have been found to be associated with altered ratios of pro-/antiapoptotic proteins, caspase activation, c-Jun N-terminal kinase (JNK) pathway activation and caspase-independent pathways.

CONCLUSION

Available scientific literature data indicate complex effects, dependent on cell lines and exposure conditions, suggesting that HSD and HST doses need to be optimized according to the cellular and organismal context. The establishment of the main antiproliferative mechanisms is of utmost importance for a possible therapeutic benefit of citrus flavanones in the context of cancer.

Metastatic propagation of thyroid cancer; organ tropism and major modulators

Thyroid cancer, as the most prevalent endocrine malignancy, comprises nearly 1% of all cancers in the world. The metastatic propagation of thyroid cancer is under the control of a number of modulating processes and factors such as signaling pathways and their components, cell division regulators, metabolic reprogramming factors, extracellular matrix remodelers, epithelial to mesenchymal transition modulators, epigenetic mechanisms, hypoxia and cytokines. Identifying the exact molecular mechanisms of these dysregulated processes could help to discover the key targets for therapeutic purposes and utilizing them as diagnostic, prognostic and predictors of the clinical course of patients. In this review article, we describe different aspects of thyroid cancer metastasis by focusing on defective genes and pathways involved in its metastatic spread.

Bioinformatics and In Vitro Studies Reveal the Importance of p53, PPARG and Notch Signaling Pathway in Inhibition of Breast Cancer Stem Cells by Hesperetin

Purpose: The failure of chemotherapy in breast cancer is caused by breast cancer stem cells (BCSCs), a minor population of cells in bulk mammary tumors. Previously, hesperetin, a citrus flavonoid, showed cytotoxicity in several cancer cells and increased cytotoxicity of doxorubicin and cisplatin. Hesperetin also inhibited osteogenic and adipocyte differentiation, however, a study of the effect of hesperetin on BCSCs has not yet been performed.

Methods: In this study, we combined bioinformatics and in vitro works. A bioinformatic approach was performed to identify molecular targets, key proteins, and molecular mechanisms of hesperetin targeted at BCSCs, and genetic alterations among key genes. In addition, an in vitro study was carried out to measure the effects of hesperetin on BCSCs using the spheroids model of MCF-7 breast cancer cells (mammospheres).

Results: Using a bioinformatics approach, we identified P53, PPARG, and Notch signaling as potential targets of hesperetin in inhibition of BCSCs. The in vitro study showed that hesperetin exhibits cytotoxicity on mammospheres, inhibits mammosphere and colony formation, and inhibits migration. Hesperetin modulates the cell cycle and induces apoptosis in mammospheres. Moreover, hesperetin treatment modulates the expression of p53, PPARG, and NOTCH1.

Conclusion: Taken together, hesperetin has potential for the treatment of BCSC by targeting p53, PPARG and Notch signaling. Further investigation of the molecular mechanisms involved is required for the development of hesperetin as a BCSC-targeted drug.

Combined tazemetostat and MAPKi enhances differentiation of papillary thyroid cancer cells harbouring BRAFV600E by synergistically decreasing global trimethylation of H3K27

Clinical efficacy of differentiation therapy with mitogen-activated protein kinase inhibitors (MAPKi) for lethal radioiodine-refractory papillary thyroid cancer (RR-PTC) urgently needs to be improved and the aberrant trimethylation of histone H3 lysine 27 (H3K27) plays a vital role in BRAF^V600E -MAPK-induced cancer dedifferentiation and drug resistance. Therefore, dual inhibition of MAPK and histone methyltransferase (EZH2) may produce more favourable treatment effects. In this study, BRAF^V600E -mutant (BCPAP and K1) and BRAF-wild-type (TPC-1) PTC cells were treated with MAPKi (dabrafenib or selumetinib) or EZH2 inhibitor (tazemetostat), or in combination, and the expression of iodine-metabolizing genes, radioiodine uptake, and toxicity were tested. We found that tazemetostat alone slightly increased iodine-metabolizing gene expression and promoted radioiodine uptake and toxicity, irrespective of the BRAF status. However, MAPKi induced these effects preferentially in BRAF^V600E mutant cells, which was robustly strengthened by tazemetostat incorporation. Mechanically, MAPKi-induced decrease of trimethylation of H3K27 was evidently intensified by tazemetostat in BRAF^V600E -mutant cells. In conclusion, tazemetostat combined with MAPKi enhances differentiation of PTC cells harbouring BRAF^V600E through synergistically decreasing global trimethylation of H3K27, representing a novel differentiation strategy.

Synergistic repression of thyroid hyperplasia by cyclin C and Pten

The cyclin C-Cdk8 kinase has been identified as both a tumor suppressor and an oncogene depending on the cell type. The genomic locus encoding cyclin C (Ccnc) is often deleted in aggressive anaplastic thyroid tumors. To test for a potential tumor suppressor role for cyclin C, Ccnc alone, or Ccnc in combination with a previously described thyroid tumor suppressor Pten, was deleted late in thyroid development. Although mice harboring individual Pten or Ccnc deletions exhibited modest thyroid hyperplasia, the double mutant demonstrated dramatic thyroid expansion resulting in animal death by 22 weeks. Further analysis revealed that Ccnc^thyr-/- tissues exhibited a reduction in signal transducer and activator of transcription 3 (Stat3) phosphorylation at Ser727. Further analysis uncovered a post-transcriptional requirement of both Pten and cyclin C in maintaining the levels of the p21 and p53 tumor suppressors (also known as CDKN1A and TP53, respectively) in thyroid tissue. In conclusion, these data reveal the first tumor suppressor role for cyclin C in a solid tumor model. In addition, this study uncovers new synergistic activities of Pten and cyclin C to promote quiescence through maintenance of p21 and p53.

Expression of NOTCH1 in thyroid cancer is mostly restricted to papillary carcinoma

The NOTCH signaling is an evolutionarily conserved signaling pathway that regulates cell-cell interactions. NOTCH family members play a fundamental role in a variety of processes during development in particular in cell fate decisions. As other crucial factors during embryogenesis, NOTCH signaling is aberrantly reactivated in cancer where it has been linked to context-dependent effects. In thyroid cancer, NOTCH1 expression has been associated to aggressive features even if its in vivo expression within the entire spectrum of thyroid tumors has not definitively established. A series of 106 thyroid specimens including non-neoplastic lesions, benign and malignant tumors of common and rare histotypes, were investigated by immunohistochemistry to assess NOTCH1 expression. Extent of positivity and protein localization were investigated and correlated with clinical and morphological parameters. NOTCH1 positivity was predominantly associated with papillary carcinomas and only occasionally found in follicular carcinomas. Poorly differentiated and undifferentiated thyroid carcinomas showed only a partial positivity. NOTCH1 expression pattern also seemed differently distributed according to histotype. Our data confirm a role of NOTCH1 in thyroid cancer and highlight for the first time the specific involvement of this pathway in papillary carcinomas. Our data also indicate that other thyroid malignancies do not rely on NOTCH1 signaling for development and progression.

Antiproliferative Effects of Cynaropicrin on Anaplastic Thyroid Cancer Cells

BACKGROUND

The sesquiterpene lactone cynaropicrin, a major constituent of the artichoke leaves extracts, has shown several biologic activities in many preclinical experimental models, including anti-proliferative effects.

OBJECTIVE

Herein we evaluated the effects of cynaropicrin on the growth of three human anaplastic thyroid carcinoma cell lines, investigating the molecular mechanism underlying its action.

METHOD

MTT assay was used to evaluate the viability of CAL-62, 8505C and SW1736 cells, and flow cytometry to analyse cell cycle distribution. Western blot was performed to detect the levels of STAT3 phosphorylation and NFkB activation. Antioxidant effects were analyzed by measuring the reactive oxygen species and malonyldialdehyde dosage was used to check the presence of lipid peroxidation.

RESULTS

Viability of CAL-62, 8505C and SW1736 cells was significantly reduced by cynaropicrin in a dose- and time-dependent way, with an EC50 of about 5 µM observed after 48 h of treatment with the compound. Cellular growth inhibition was accompanied both by an arrest of the cell cycle, mainly in the G2/M phase, and the presence of a significant percentage of necrotic cells. After 48 h of treatment with 10 µM of cynaropicrin, a reduced nuclear expression of NFkB and STAT3 phosphorylation were also revealed. Moreover, we observed an increase in lipid peroxidation, without any significant effect on the reactive oxygen species production.

CONCLUSION

These results demonstrate that cynaropicrin reduces the viability and promotes cytotoxic effects in anaplastic thyroid cancer cells associated with reduced NFkB expression, STAT3 phosphorylation and increased lipid peroxidation. Further characterization of the properties of this natural compound may open the way for using cynaropicrin as an adjuvant in the treatment of thyroid cancer.

Major vault protein is a direct target of Notch1 signaling and contributes to chemoresistance in triple-negative breast cancer cells

Resistance to chemotherapy remains a significant problem in the treatment of breast cancer, especially for triple-negative breast cancer (TNBC), in which standard systemic therapy is currently limited to chemotherapeutic agents. Our study aimed to better understand the molecular mechanisms that lead to failure of chemotherapy in TNBC. Herein, we observed elevated expression of Notch1 and major vault protein (MVP) in MDA-MB-231DDPR cells compared to their parental counterparts. We demonstrated that Notch1 could positively regulate the expression of MVP. Also, Notch1 intracellular domain (ICD) was capable of binding to CBF-1 on the promoter of MVP to drive its transcription, resulting in activation of AKT pathway and promoting the progress of epithelial to mesenchymal transition (EMT). Conversely, silencing of Notch1 and MVP suppressed AKT pathway, reduced EMT and enhanced the sensitivity of TNBC cells to cisplatin and doxorubicin. Survival analysis indicated that the MVP was closely related to shorter recurrence-free survival (RFS) in patients with TNBC. Collectively, this study provides evidence that Notch1 activates AKT pathway and promotes EMT partly through direct activation of MVP. Targeting Notch1/MVP pathway appears to have potential in overcoming chemoresistance in TNBC.

Molecular aberrations and signaling cascades implicated in the pathogenesis of anaplastic thyroid cancer

Anaplastic Thyroid Cancer (ATC) accounts for >40% thyroid cancer-related deaths and has a dismal prognosis. In the past decade, significant efforts have been made towards understanding the pathogenesis of this disease and developing novel therapeutics. Unfortunately, effective treatment is still lacking and a more thorough understanding of ATC pathogenesis may provide new opportunities to improve ATC therapeutics. This review provides insights into ATC clinical presentation and pathology, and the putative role of genetic aberrations and alterations in molecular signaling pathways in ATC pathogenesis. We reviewed prevalent mutations, chromosomal abnormalities and fusions, epigenetic alterations and dysregulations in ATC, and highlighted several signaling cascades which appeared to be integral to ATC pathogenesis. Moreover, these features offer insights into de-differentiated, aggressive and drug-resistant phenotype of ATC, and thus may help in exploring potential new molecular targets for developing novel therapeutics.

Therapeutic advances in anaplastic thyroid cancer: a current perspective

Thyroid cancer incidence is increasing at an alarming rate, almost tripling every decade. In 2017, it was the fifth most common cancer in women. Although the majority of thyroid tumors are curable, about 2-3% of thyroid cancers are refractory to standard treatments. These undifferentiated, highly aggressive and mostly chemo-resistant tumors are phenotypically-termed anaplastic thyroid cancer (ATC). ATCs are resistant to standard therapies and are extremely difficult to manage. In this review, we provide the information related to current and recently emerged first-line systemic therapy (Dabrafenib and Trametinib) along with promising therapeutics which are in clinical trials and may be incorporated into clinical practice in the future. Different categories of promising therapeutics such as Aurora kinase inhibitors, multi-kinase inhibitors, epigenetic modulators, gene therapy using oncolytic viruses, apoptosis-inducing agents, and immunotherapy are reviewed. Combination treatment options that showed synergistic and antagonistic effects are also discussed. We highlight ongoing clinical trials in ATC and discuss how personalized medicine is crucial to design the second line of treatment. Besides using conventional combination therapy, embracing a personalized approach based on advanced genomics and proteomics assessment will be crucial to developing a tailored treatment plan to improve the chances of clinical success.

Signaling cascades in thyroid cancer: Increasing the armory of archers to hit bullseye

Thyroid cancer is a multifaceted and therapeutically challenging disease and rapidly accumulating experimentally verified findings have considerably improve our understanding of the molecular mechanisms which underlie its development. Substantial fraction of information has been added into existing landscape of molecular oncology and we have started to develop a sharper understanding of the underlying mechanisms of thyroid cancer. Wealth of information demystified different intracellular signaling cascades which are frequently deregulated in thyroid cancer. In vitro assays and xenografted mice based studies have helped us to identify drug targets and different synthetic and natural products are currently being tested to effectively treat thyroid cancer. Cabozantinib and vandetanib have been approved to treat medullary thyroid cancer (MTC) and two agents (lenvatinib and sorafenib) are also being used to treat radioactive-iodine refractory differentiated thyroid cancer. This review comprehensively summarizes most recent advancements in our knowledge related to dysregulated intracellular signaling cascades in thyroid cancer and how different proteins can be therapeutically exploited. (1) We discuss how loss of TRAIL mediated apoptosis occurred in thyroid cancer cells and how different strategies can be used to restore apoptosis in resistant cancer cells; (2) We provide detailed account of seemingly opposite roles of NOTCH signaling in thyroid cancers; (3) TGF/SMAD mediated signaling also needs detailed research because of context dependent role in thyroid cancer. Researchers have only begun to scratch the surface of how TGF signaling works in thyroid cancer and metastasis; and (4) Role of SHH signaling in thyroid cancer stem cells is also well appreciated and targeting of SHH pathway will be an important aspect in treatment of thyroid cancer. Better concepts and improved knowledge will be helpful for clinicians in getting a step closer to individualized medicine.

PARP Inhibition by Flavonoids Induced Selective Cell Killing to BRCA2-Deficient Cells

High consumption of dietary flavonoids might contribute to a reduction of cancer risks. Quercetin and its glycosides have PARP inhibitory effects and can induce selective cytotoxicity in BRCA2-deficient cells by synthetic lethality. We hypothesized that common flavonoids in diet naringenin, hesperetin and their glycosides have a similar structure to quercetin, which might have comparable PARP inhibitory effects, and can induce selective cytotoxicity in BRCA2-deficient cells. We utilized Chinese hamster V79 wild type, V-C8 BRCA2-deficient and its gene-complemented cells. In vitro analysis revealed that both naringenin and hesperetin present a PARP inhibitory effect. This inhibitory effect is less specific than for quercetin. Hesperetin was more cytotoxic to V79 cells than quercetin and naringenin based on colony formation assay. Quercetin and naringenin killed V-C8 cells with lower concentrations, and presented selective cytotoxicity to BRCA2-deficient cells. However, the cytotoxicity of hesperetin was similar among all three cell lines. Glycosyl flavonoids, isoquercetin and rutin as well as naringin showed selective cytotoxicity to BRCA2-deficient cells; hesperidin did not. These results suggest that flavonoids with the PARP inhibitory effect can cause synthetic lethality to BRCA2-deficient cells when other pathways are not the primary cause of death.

Periostin silencing suppresses the aggressive phenotype of thyroid carcinoma cells by suppressing the Akt/thyroid stimulating hormone receptor axis

Clinical evidence indicates that high periostin expression correlates with aggressive phenotype in thyroid carcinoma. However, the biological roles of periostin in thyroid carcinoma development and progression are still unclear. In this study, we explored the effects of periostin silencing on thyroid carcinoma cell growth, invasion, and tumorigenesis. We also studied the impact of periostin on the activation of phosphoinositide 3-kinase (PI3-K)/Akt signaling, which is involved in the pathogenesis of thyroid carcinoma. It was found that downregulation of periostin significantly inhibited the proliferation, colony formation, and invasion in both FTC-133 and BCPAP thyroid carcinoma cells. In vivo tumorigenic studies confirmed that periostin depletion retarded the growth of subcutaneous FTC-133 xenograft tumors, which was coupled with a significant decline in the percentage of Ki-67-positive proliferating cells. Western blot analysis demonstrated that periostin downregulation caused a marked inhibition of thyroid stimulating hormone receptor (TSHR) expression and Akt phosphorylation in FTC-133 and BCPAP cells. Co-expression of constitutively active Akt (CA-Akt) significantly reversed periostin-mediated downregulation of TSHR. Most importantly, overexpression of TSHR or CA-Akt rescued FTC-133 cells from periostin-induced growth and invasion suppression. Collectively, periostin regulates thyroid carcinoma growth and progression via the Akt/TSHR axis and represents a promising therapeutic target for this malignancy.

Flavonoids, Thyroid Iodide Uptake and Thyroid Cancer-A Review

Thyroid cancer is the most common malignant tumor of the endocrine system and the incidence has been increasing in recent years. In a great part of the differentiated carcinomas, thyrocytes are capable of uptaking iodide. In these cases, the main therapeutic approach includes thyroidectomy followed by ablative therapy with radioiodine. However, in part of the patients, the capacity to concentrate iodide is lost due to down-regulation of the sodium-iodide symporter (NIS), the protein responsible for transporting iodide into the thyrocytes. Thus, therapy with radioiodide becomes ineffective, limiting therapeutic options and reducing the life expectancy of the patient. Excessive ingestion of some flavonoids has been associated with thyroid dysfunction and goiter. Nevertheless, studies have shown that some flavonoids can be beneficial for thyroid cancer, by reducing cell proliferation and increasing cell death, besides increasing NIS mRNA levels and iodide uptake. Recent data show that the flavonoids apingenin and rutin are capable of increasing NIS function and expression in vivo. Herein we review literature data regarding the effect of flavonoids on thyroid cancer, besides the effect of these compounds on the expression and function of the sodium-iodide symporter. We will also discuss the possibility of using flavonoids as adjuvants for therapy of thyroid cancer.

Notch as a tumour suppressor

The Notch signalling cascade is an evolutionarily conserved pathway that has a crucial role in regulating development and homeostasis in various tissues. The cellular processes and events that it controls are diverse, and continued investigation over recent decades has revealed how the role of Notch signalling is multifaceted and highly context dependent. Consistent with the far-reaching impact that Notch has on development and homeostasis, aberrant activity of the pathway is also linked to the initiation and progression of several malignancies, and Notch can in fact be either oncogenic or tumour suppressive depending on the tissue and cellular context. The Notch pathway therefore represents an important target for therapeutic agents designed to treat many types of cancer. In this Review, we focus on the latest developments relating specifically to the tumour-suppressor activity of Notch signalling and discuss the potential mechanisms by which Notch can inhibit carcinogenesis in various tissues. Potential therapeutic strategies aimed at restoring or augmenting Notch-mediated tumour suppression will also be highlighted.

Notch1 targeted regulation of mir-224/LRIG2 signaling for the proliferation and apoptosis of cervical cancer cells

In the present study, we explored the participation of Notch1 targeted regulation of mir-224/LRIG2 gene signal pathway in proliferation and apoptosis of cervical cancer cells. Forty-nine cases of cervical cancer lesion samples from cervical cancer patients treated in our hospital from February 2013 to February 2015 were chosen as subjects (the observation group), and cervical samples of healthy women (42 cases) during the same period were used as the control group. We determined the mRNA and protein expression of Notch1, mir-224, and LRIG2 genes. We also analyzed the mutual relationship between Notch1 gene expression and cervical cancer. The Notch1 genes in the cervical cancer cells (HeLa) were silenced and overexpressed to measure cancer apoptosis with flow cytometry. After obstruction of the Notch1 signal pathway, the mRNA and protein expression in the mir-224 and LRIG2 genes was also measured. It was found that in comparison to the control group, Notch1 gene expression in the observation group was significantly higher (p<0.05), cell growth was suppressed in Notch1 silent cell strains but accelerated in overexpressed Notch1 cells. The silencing of Notch1 genes can lead to the reduction of mir-224/LRIG gene and protein levels, while overexpression of the Notch1 genes increased the mir-224/LRIG gene and protein levels. In conclusion, the Notch1 gene is positively related to cervical cancer and can promote the occurrence of the disease. The potential mechanism shows that Notch1 gene can regulate cervical cancer cell proliferation by regulating the mir-224/LRIG2 signal pathway.

Notch3 expression correlates with thyroid cancer differentiation, induces apoptosis, and predicts disease prognosis

BACKGROUND

Thyroid tumorigenesis is characterized by a progressive loss of differentiation exhibited by a range of disease variants. The Notch receptor family (1-4) regulates developmental progression in both normal and cancerous tissues. This study sought to characterize the third Notch isoform (Notch3) across the various differentiated states of thyroid cancer, and determine its clinical impact.

METHODS

Notch3 expression was analyzed in a tissue microarray of normal and pathologic thyroid biopsies from 155 patients. The functional role of Notch3 was then investigated by upregulating its expression in a follicular thyroid cancer (FTC) cell line.

RESULTS

Notch3 expression regressed across decreasingly differentiated, increasingly malignant thyroid specimens, correlated with clinicopathological attributes reflecting poor prognosis, and independently predicted survival following univariate and multivariate analyses. Overexpression of the active Notch3 intracellular domain (NICD3) in a gain-of-function FTC line led to functional activation of centromere-binding protein 1, while increasing thyroid-specific gene transcription. NICD3 induction also reduced tumor burden in vivo and initiated the intrinsic apoptotic cascade, alongside suppressing cyclin and B-cell lymphoma 2 family expression.

CONCLUSIONS

Loss of Notch3 expression may be fundamental to the process of dedifferentiation that accompanies thyroid oncogenesis. Conversely, activation of Notch3 in thyroid cancer exerts an antiproliferative effect and restores elements of a differentiated phenotype. These findings provide preclinical rationale for evaluating Notch3 as a disease prognosticator and therapeutic target in advanced thyroid cancer. Cancer 2017;123:769-82. © 2016 American Cancer Society.

Signaling Pathways in Thyroid Cancer and Their Therapeutic Implications

Thyroid cancer is a common malignancy of endocrine system, and has now become the fastest increasing cancer among all the malignancies. The development, progression, invasion, and metastasis are closely associated with multiple signaling pathways and the functions of related molecules, such as Src, Janus kinase (JAK)-signal transducers and activators of transcription (STAT), mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase (PI3K)/Akt, NF-κB, thyroid stimulating hormone receptor (TSHR), Wnt-β-catenin and Notch signaling pathways. Each of the signaling pathways could exert its function singly or through network with other pathways. These pathways could cooperate, promote, antagonize, or interact with each other to form a complex network for the regulation. Dysfunction of this network could increase the development, progression, invasion, and metastasis of thyroid cancer. Inoperable thyroid cancer still has a poor prognosis. However, signaling pathway-related targeted therapies offer the hope of longer quality of meaningful life for this small group of patients. Signaling pathway-related targets provide unprecedented opportunities for further research and clinical development of novel treatment strategies for this cancer. In the present work, the advances in these signaling pathways and targeted treatments of thyroid cancer were reviewed.

Notch1 Signaling Regulates the Aggressiveness of Differentiated Thyroid Cancer and Inhibits SERPINE1 Expression

PURPOSE

Notch1, a transmembrane receptor, has been recently shown to aid in the determination of thyroid cell fate associated with tumorigenesis. This study aimed to investigate the clinical relevance of Notch1 and its role in the regulation of differentiated thyroid cancer (DTC) behavior.

EXPERIMENTAL DESIGN

We examined Notch1 expression level and its relationship with clinicopathologic features and outcomes of DTC. Notch1 intracellular domain (NICD) was further characterized both in vitro and in vivo by gain-of-function assays using an inducible system.

RESULTS

Notch1 expression levels were downregulated in primary DTC tissue samples compared with contralateral nontumor and benign thyroid tissues. Decreased Notch1 expression in DTC was associated with advanced patient age (P = 0.032) and the presence of extrathyroidal invasion (P = 0.005). Patients with lower Notch1 expression had a significantly higher recurrence rate (P = 0.038). Restoration of NICD in a stably doxycycline-inducible metastatic DTC cell line reduced cell growth and migration profoundly. Using an orthotopic thyroid cancer model, NICD induction significantly reduced the growth of the primary thyroid tumor and inhibited the development of lung metastasis. Serpin peptidase inhibitor, clade E, member 1 (SERPINE1) was discovered by microarray as the most significant gene downregulated by NICD. Further validation showed that the induction of NICD reduced SERPINE1 expression in a dose-dependent manner, whereas restoration of a relative higher level of SERPINE1 was observed with NICD back to minimal level. In addition, SERPINE1 knock-down inhibited DTC cell migration.

CONCLUSIONS

Notch1 regulates the aggressive phenotypes of DTC, which could be mediated by SERPINE1 inhibition. Notch1/SERPINE1 axis warrants further investigation as a novel therapeutic target for advanced DTC. Clin Cancer Res; 22(14); 3582-92. ©2016 AACR.

Hesperetin derivatives: Synthesis and anti-inflammatory activity

Sixteen novel hesperetin derivatives containing Mannich base moiety were designed and synthesized and their anti-inflammatory activities were evaluated by inhibiting tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in mouse RAW264.7 macrophages. Compounds 3a-3k showed better hydrophilic, while compounds 3l-3p with aromatic groups was hydrophobic. The anti-inflammatory activity of title compounds was correlated with logP values, among them, compounds 3c, 3e and 3i with minus logP values exhibited best anti-inflammatory activity through decreasing both IL-6 and TNF-α. Furthermore, the expression of LPS-induced notch1 and inos was reduced by compounds 3c, 3e, and 3i, and compound 3e attenuated LPS-induced inos protein levels in a dose-dependent manner.

Role of autophagy on bone marrow mesenchymal stem‑cell proliferation and differentiation into neurons

The purpose of the present study was to investigate the role of autophagy on rat bone marrow mesenchymal stem cell (BMSC) proliferation, apoptosis and differentiation into neurons. After treatment with rapamycin, 3-methyladenine (3-MA) or chloroquine, the cell cycle, apoptosis, expression of neuron-specific enolase (NSE) and the mean fluorescence intensity (MFI) of Notch1 in BMSCs were examined by flow cytometry. The expression of microtubule-associated protein 2 (MAP2), Notch1 and Hes1 was investigated by western blot analysis. The results showed that after induction of autophagy using rapamycin, the proliferation of BMSCs was inhibited. Furthermore, the S-phase population was significantly decreased compared to that in the control group (P<0.05). In addition, the percentage of NSE-positive cells and the expression of MAP2 were significantly increased compared to those in the control group (P<0.05). The MFI of Notch1 was markedly upregulated compared to that in the control group (P<0.05). When autophagy was inhibited by 3-MA or chloroquine, the percentage of apoptotic cells and NSE-positive cells as well as the expression of MAP2 were markedly reduced compared to those in the control group (P<0.05). Furthermore, western blot analysis showed that Notch1 and Hes1 were decreased in the rapamycin-treated group, while they were not affected by 3-MA or chloroquine. The present study indicated that induction of autophagy in BMSCs decreased their S-phase population, promoted their differentiation into neurons and promoted the expression of NSE and MAP2. The mechanisms underlying this process may be linked to the regulation of autophagy-induced inhibition of the Notch1 signaling pathway.

Reversion of malignant phenotypes of human glioblastoma cells by β-elemene through β-catenin-mediated regulation of stemness-, differentiation- and epithelial-to-mesenchymal transition-related molecules

Background

Glioblastoma is the most common and lethal type of primary brain tumor. β-Elemene, a natural plant drug extracted from Curcuma wenyujin, has shown strong anti-tumor effects in various tumors with low toxicity. However, the effects of β-elemene on malignant phenotypes of human glioblastoma cells remain to be elucidated. Here we evaluated the effects of β-elemene on cell proliferation, survival, stemness, differentiation and the epithelial-to-mesenchymal transition (EMT) in vitro and in vivo, and investigated the mechanisms underlying these effects.

Methods

Human primary and U87 glioblastoma cells were treated with β-elemene, cell viability was measured using a cell counting kit-8 assay, and treated cells were evaluated by flow cytometry. Western blot analysis was carried out to determine the expression levels of stemness markers, differentiation-related molecules and EMT-related effectors. Transwell assays were performed to further determine EMT of glioblastoma cells. To evaluate the effect of β-elemene on glioblastoma in vivo, we subcutaneously injected glioblastoma cells into the flank of nude mice and then intraperitoneally injected NaCl or β-elemene. The tumor xenograft volumes were measured every 3 days and the expression of stemness-, differentiation- and EMT-related effectors was determined by Western blot assays in xenografts.

Results

β-Elemene inhibited proliferation, promoted apoptosis, impaired invasiveness in glioblastoma cells and suppressed the growth of animal xenografts. The expression levels of the stemness markers CD133 and ATP-binding cassette subfamily G member 2 as well as the mesenchymal markers N-cadherin and β-catenin were significantly downregulated, whereas the expression levels of the differentiation-related effectors glial fibrillary acidic protein, Notch1, and sonic hedgehog as well as the epithelial marker E-cadherin were upregulated by β-elemene in vitro and in vivo. Interestingly, the expression of vimentin was increased by β-elemene in vitro; this result was opposite that for the in vivo procedure. Inhibiting β-catenin enhanced the anti-proliferative, EMT-inhibitory and specific marker expression-regulatory effects of β-elemene.

Conclusions

β-Elemene reversed malignant phenotypes of human glioblastoma cells through β-catenin-involved regulation of stemness-, differentiation- and EMT-related molecules. β-Elemene represents a potentially valuable agent for glioblastoma therapy.

Hesperetin Induces the Apoptosis of Gastric Cancer Cells via Activating Mitochondrial Pathway by Increasing Reactive Oxygen Species

BACKGROUND

Hesperetin, has been shown to exert biological activities on various types of human cancers. However, few related studies on gastric cancer are available.

AIM

In this study, we sought to investigate the effect of hesperetin on gastric cancer and clarify its specific mechanism.

MATERIALS AND METHODS

Cell Counting Kit-8, 2',7'-dichlorofluorescin diacetate, JC-1, Hoechst 33258 staining, and western bolt were used to detect cell viability, levels of intracellular reactive oxygen species (ROS), changes in mitochondrial membrane potential (△ψ m), cell apoptosis, and expressions of mitochondrial pathway proteins, respectively. Meanwhile, xenograft tumor models in nude mice were made to evaluate the effect of hesperetin on gastric cancer in vivo.

RESULTS

Compared with the control group, the proliferation of gastric cancer cells in hesperetin groups was significantly inhibited (P < 0.05), and dose- and time-dependent effects were observed. Pretreatment with H2O2 (1 mM) or N-acetyl-L-cysteine (5 mM) enhanced or attenuated the hesperetin-induced inhibition of cell viability (P < 0.05). Percentages of apoptotic cells, levels of intracellular ROS, and △ψ m varied with the dose and treatment time of hesperetin (P < 0.05), and hesperetin caused an increase in the levels of AIF, Apaf-1, Cyt C, caspase-3, caspase-9, and Bax and a decrease in Bcl-2 levels (P < 0.05). Meanwhile, hesperetin significantly inhibited the growth of xenograft tumors (P < 0.05).

CONCLUSION

Our study suggests that hesperetin could inhibit the proliferation and induce the apoptosis of gastric cancer cells via activating the mitochondrial pathway by increasing the ROS.

Modulation of sodium iodide symporter in thyroid cancer

Radioactive iodine (RAI) is a key therapeutic modality for thyroid cancer. Loss of RAI uptake in thyroid cancer inversely correlates with patient's survival. In this review, we focus on the challenges encountered in delivering sufficient doses of I-131 to eradicate metastatic lesions without increasing the risk of unwanted side effects. Sodium iodide symporter (NIS) mediates iodide influx, and NIS expression and function can be selectively enhanced in thyroid cells by thyroid-stimulating hormone. We summarize our current knowledge of NIS modulation in normal and cancer thyroid cells, and we propose that several reagents evaluated in clinical trials for other diseases can be used to restore or further increase RAI accumulation in thyroid cancer. Once validated in preclinical mouse models and clinical trials, these reagents, mostly small-molecule inhibitors, can be readily translated into clinical practice. We review available genetically engineered mouse models of thyroid cancer in terms of their tumor development and progression as well as their thyroid function. These mice will not only provide important insights into the mechanisms underlying the loss of RAI uptake in thyroid tumors but will also serve as preclinical animal models to evaluate the efficacy of candidate reagents to selectively increase RAI uptake in thyroid cancers. Taken together, we anticipate that the optimal use of RAI in the clinical management of thyroid cancer is yet to come in the near future.