Targeting Nrf2 to treat thyroid cancer.

Oxidative stress (OS) is recognized as a contributing factor in the development and progression of thyroid cancer. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a pivotal transcription factor involved in against OS generated by excessive reactive oxygen species (ROS). It governs the expression of a wide array of genes implicated in detoxification and antioxidant pathways. However, studies have demonstrated that the sustained activation of Nrf2 can contribute to tumor progression and drug resistance in cancers. The expression of Nrf2 was notably elevated in papillary thyroid cancer tissues compared to normal tissues, indicating that Nrf2 may play an oncogenic role in the development of papillary thyroid cancer. Nrf2 and its downstream targets are involved in the progression of thyroid cancer by impacting the prognosis and ferroptosis. Furthermore, the inhibition of Nrf2 can increase the sensitivity of target therapy in thyroid cancer. Therefore, Nrf2 appears to be a potential therapeutic target for the treatment of thyroid cancer. This review summarized current data on Nrf2 expression in thyroid cancer, discussed the function of Nrf2 in thyroid cancer, and analyzed various strategies to inhibit Nrf2.

Sodium-iodide symporter and its related solute carriers in thyroid cancer.

The solute carrier (SLC) family is a large group of membrane transport proteins. Their dysfunction plays an important role in the pathogenesis of thyroid cancer. The most well-known SLC is the sodium-iodide symporter (NIS), also known as sodium/iodide co-transporter or solute carrier family 5 member 5 (SLC5A5) in thyroid cancer. The dysregulation of NIS in thyroid cancer is well documented. The role of NIS in the uptake of iodide is critical in the treatment of thyroid cancer, radioactive iodide (RAI) therapy in particular. In addition to NIS, other SLC members may affect the autophagy, proliferation, and apoptosis of thyroid cancer cells, indicating that an alteration in SLC members may affect different cellular events in the evolution of thyroid cancer. The expression of the SLC members may impact the uptake of chemicals by the thyroid, suggesting that targeting SLC members may be a promising therapeutic strategy in thyroid cancer.

Autophagy regulates anti-angiogenic property of lenvatinib in thyroid cancer.

We aimed to explore the role of lenvatinib-mediated autophagy in papillary thyroid cancer (PTC). K1 and BCPAP, were tested for cell viability, proliferation, and apoptosis after treatment with lenvatinib or chloroquine (CQ) or both. The levels of angiogenesis vascular endothelial growth factor A (VEGFA) were measured by ELISA. Transwell and wound-healing assays were performed using endothelial HUVECs cells. The dynamics of microvessels were detected by tubular formation assay. Western blotting was used to determine the expression of LC3-I/II and Atg-7 and alterations in the PI3K/Akt/mTOR and MEK/ERK pathways. In vivo tumor growth assay and immunohistochemical staining (IHC) was also performed. The results showed that lenvatinib inhibited the viability of K1 and BCPAP cells and caused apoptosis. We further showed that lenvatinib also upregulated autophagy levels in thyroid cancer cells in a dose-dependent manner through the PI3K/Akt/mTOR and MEK/ERK pathways. Co-administration of lenvatinib with CQ resulted in a greater decrease of VEGFA in the tumor supernatant than with either lenvatinib or CQ alone. Autophagy inhibition enhanced the cytotoxicity and anti-angiogenic ability of lenvatinib, which was supported by the HUVECs migration, wound healing, and tube formation assays. Inhibiting autophagy chemically or genetically enhanced lenvatinib's cytotoxic effects and anti-angiogenic efficacy in thyroid cancer cells in vitro and in vivo. In conclusion, lenvatinib inhibited cell viability and induced apoptosis and autophagy in human PTC cells. Significantly, the combination of lenvatinib and autophagy inhibition may represent a novel and effective treatment option for PTC, which may be able to overcome drug resistance.

The Isoforms of Estrogen Receptor Alpha and Beta in Thyroid Cancer.

The incidence of thyroid cancer was predominant in women, indicating that the sex hormone may have a role in thyroid cancer development. Generally, the sex hormone exerts its function by binding to the correspondent nuclear receptors. Therefore, aberrant of these receptors may be involved in the development of thyroid cancer. Estrogen receptor alpha (ERα) and beta (ERß), two main estrogen receptors, have been reported to have an important role in the pathogenesis of thyroid cancer. When the ERα and ERß genes undergo the alternative RNA splicing, some ERα and ERß isoforms with incomplete functional domains may be formed. To date, several isoforms of ERα and ERß have been identified. However, their expression and roles in thyroid cancer are far from clear. In this review, we summarized the expressions and roles of ERα and ERß isoforms in thyroid cancer, aiming to provide the perspective of modulating the alternative RNA splicing of ERα and ERß against thyroid cancer.

The emerging role of transcription factor FOXP3 in thyroid cancer.

Transcription factor FOXP3 is a crucial regulator in the development and function of regulatory T cells (Treg) that are essential for immunological tolerance and homeostasis. Numerous studies have indicated the correlation of tumor infiltrating FOXP3+ Treg upregulation with poor prognostic parameters in thyroid cancer, including lymph node metastases, extrathyroidal extension, and multifocality. Most immune-checkpoint molecules are expressed in Treg. The blockage of such signals with checkpoint inhibitors has been approved for several solid tumors, but not yet for thyroid cancer. Thyroid abnormalities may be induced by checkpoint inhibitors. For example, hypothyroidism, thyrotoxicosis, painless thyroiditis, or even thyroid storm are more frequently associated with anti-PD-1 antibodies (pembrolizumab and nivolumab). Therefore, Targeting FOXP3+ Treg may have impacts on checkpoint molecules and the growth of thyroid cancer. Several factors may impact the role and stability of FOXP3, such as alternative RNA splicing, mutations, and post-translational modification. In addition, the role of FOXP3+ Treg in the tumor microenvironment is also affected by the complex regulatory network formed by FOXP3 and its transcriptional partners. Here we discussed how the expression and function of FOXP3 were regulated and how FOXP3 interacted with its targets in Treg, aiming to help the development of FOXP3 as a potential therapeutic target for thyroid cancer.

Differential Effects of Estrogen Receptor Alpha and Beta on Endogenous Ligands of Peroxisome Proliferator-Activated Receptor Gamma in Papillary Thyroid Cancer.

Purpose: The inhibition of estrogen receptor alpha (ERα) or the activation of ERß can inhibit papillary thyroid cancer (PTC), but the precise mechanism is not known. We aimed to explore the role of ERα and ERß on the production of endogenous peroxisome proliferator-activated receptor gamma (PPARγ) ligands in PTC. Methods: 2 PTC cell lines, 32 pairs of PTC tissues and matched normal thyroid tissues were used in this study. The levels of endogenous PPARγ ligands 15(S)-hydroxyeicosatetraenoic acid (15(S)-HETE), 13-S-hydroxyoctadecadienoic acid (13(S)-HODE), and15-deoxy-Δ12,14-prostaglandin J2 (PGJ2) were measured by ELISA. Results: The levels of PGJ2 and 15(S)-HETE were significantly reduced in PTC, but 13(S)-HODE was not changed. Activation of ERα or inhibition of ERß significantly downregulated the production of PGJ2, 15(S)-HETE and 13(S)-HODE, whereas inhibition of ERα or activation of ERß markedly upregulated the production of these three ligands. Application of endogenous PPARγ ligands inhibited growth, induced apoptosis of cancer cells, and promoted the efficacy of chemotherapy. Conclusion: The levels of endogenous PPARγ ligands PGJ2 and 15(S)-HETE are significantly decreased in PTC. The inhibition of ERα or activation of ERß can inhibit PTC by stimulating the production of endogenous PPARγ ligands to induce apoptosis in cancer cells.

The Knockdown of Nrf2 Suppressed Tumor Growth and Increased the Sensitivity to Lenvatinib in Anaplastic Thyroid Cancer.

Papillary thyroid cancer can dedifferentiate into a much more aggressive form of thyroid cancer, namely into anaplastic thyroid cancer. Nrf2 is commonly activated in papillary thyroid cancer, whereas its role in anaplastic thyroid cancer has not been fully explored. In this study, we used two cell lines and an animal model to examine the function of Nrf2 in anaplastic thyroid cancer. The role of Nrf2 in anaplastic thyroid cancer was investigated by a series of functional studies in two anaplastic thyroid cancer cell lines, FRO and KAT-18, and further confirmed with an in vivo study. The impact of Nrf2 on the sensitivity of anaplastic thyroid cancer cells to lenvatinib was also investigated to evaluate its potential clinical implication. We found that the expression of Nrf2 was significantly higher in anaplastic thyroid cancer cell line cells than in papillary thyroid cancer cells or normal control cells. Knockdown of Nrf2 in anaplastic thyroid cancer cells inhibited their viability and clonogenicity, reduced their migration and invasion ability in vitro, and suppressed their tumorigenicity in vivo. Mechanistically, knockdown of Nrf2 decreased the expression of Notch1. Lastly, knockdown of Nrf2 increased the sensitivity of anaplastic thyroid cancer cells to lenvatinib. As knockdown of Nrf2 reduced the metastatic and invasive ability of anaplastic thyroid cancer cells by inhibiting the Notch 1 signaling pathway and increased the cancer cell sensitivity to lenvatinib, Nrf2 could be a promising therapeutic target for patients with anaplastic thyroid cancer.

CYP1A2 suppresses hepatocellular carcinoma through antagonizing HGF/MET signaling.

Rationale: Hyperactivation of HGF/MET signaling pathway is a critical driver in liver tumorigenesis. Cytochrome P450 1A2 (CYP1A2) was significantly down-regulated in hepatocellular carcinoma (HCC). However, little is explored about its tumor suppressive role in HCC. In this study, we examined the functional mechanisms and clinical implication of CYP1A2 in HCC. Methods: The clinical impact of CYP1A2 was evaluated in HCC patients in Hong Kong cohort. The biological functions of CYP1A2 were investigated in vitro and in vivo. A series of biochemical experiments including Western blot assay, immunohistochemistry, quantitative reverse transcription-polymerase chain reaction, and Co-immunoprecipitation assay were conducted. Results: CYP1A2 expression was prominently silenced in HCC tumor tissues and the high expression of CYP1A2 was significantly correlated with lower AFP level, less vascular invasion, and better tumor-free survival in local cohort of HCC patients. The overexpression of CYP1A2 inhibited HCC cell viability and clonogenicity, reduced cell migration and invasion abilities in vitro, and suppressed tumorigenicity in vivo, whereas CYP1A2 knockdown exhibited the opposite effects. CYP1A2 significantly hindered HGF/MET signaling and Matrix metalloproteinases (MMPs) expression in HCC cells. Mechanically, CYP1A2 decreased HGF level and diminished HIF-1α expression, both of which are recognized as key regulators of MET activation. As the transcriptional activator of MET, HIF-1α was identified as a binding partner of CYP1A2. Direct binding of CYP1A2 with HIF-1α induced ubiquitin-mediated degradation of HIF-1α, inhibiting HIF-1α-mediated transcriptions. Conclusions: In conclusion, our results have identified CYP1A2 as a novel antagonist of HGF/MET signaling, and CYP1A2 may serve as an independent new biomarker for the prognosis of HCC patients.

Cytochrome P450 1A2 overcomes nuclear factor kappa B-mediated sorafenib resistance in hepatocellular carcinoma.

Sorafenib resistance has become the main obstacle in the effective treatment of advanced hepatocellular carcinoma (HCC) patients. Activation of nuclear factor kappa B (NF-κB) is a newly identified mechanism that contributes to desensitized sorafenib. Cytochrome P450 1A2 (CYP1A2) functions as a tumor suppressor in HCC and its expression is negatively associated with NF-κB in the liver. This study aimed to study whether CYP1A2 could overcome sorafenib resistance. To investigate whether CYP1A2 and NF-κB p65 played roles in sorafenib desensitization, we established sorafenib-resistant (SR) HCC cells. SR cells decreased the expression of CYP1A2 along with the upregulation of NF-κB p65. CYP1A2 overexpression attenuated SR cell proliferation, increased sorafenib sensitivity, and inhibited the NF-κB pathway, whereas CYP1A2 silence showed opposite effects. Sorafenib, in combination with omeprazole, a CYP1A2 inducer, significantly hindered the growth and invasion of SR cells in vitro as well as decreased the tumor growth in vivo. The combination treatment markedly increased CYP1A2 expression and inhibited the sorafenib-induced NF-κB signaling. In addition, the overexpression of NF-κB p65 stimulated the SR cell growth and desensitized sorafenib in SR cells, where CYP1A2 overexpression reversed the phenomenon. Lastly, the majority of HCC tissue samples displayed decreased CYP1A2 but increased NF-κB p65 protein expression. Collectively, CYP1A2 can sensitize SR cells to sorafenib via inhibiting NF-κB p65 axis. Omeprazole in combination with sorafenib exerts a synergistic effect in alleviating acquired sorafenib resistance.

Nuclear FOXP3 inhibits tumor growth and induced apoptosis in hepatocellular carcinoma by targeting c-Myc.

The status of FOXP3 and its isoforms in hepatocellular carcinoma (HCC) is unclear. We aimed to investigate the expression and function of FOXP3 and its isoforms in HCC. The study was performed on 84 HCC patients, HCC cell lines and a mouse tumor model. The levels of FOXP3 and its isoforms were determined by nested PCR, quantitative real-time PCR and immunohistochemistry (IHC) staining. The correlation between their levels and clinicopathologic characteristics was analyzed. The full length of FOXP3 (FOXP3) and exon 3-deleted FOXP3 (FOXP3Δ3) were found to be the major isoforms in HCC. The levels of FOXP3Δ3 mRNA and protein in HCC tumor samples were not significantly different from their adjacent normal tissues. The high expression of FOXP3 protein in HCC patients showed a good overall survival. The overexpression of FOXP3 significantly reduced tumor cell proliferation, migration and invasion. The immunofluorescence result indicated that FOXP3 needed to be translocated into the nucleus to exert its inhibitory function. The luciferase assay demonstrated that FOXP3 could be synergistic with Smad2/3/4 to inhibit the oncogene c-Myc. The co-immunoprecipitation results further revealed that FOXP3 could interact with Smad2/3/4. The chromatin immunoprecipitation (ChIP) assay showed that both FOXP3 and Smad2/3/4 bound the promoter of the c-Myc to inhibit it. The in vivo mouse tumor model study confirmed the inhibitory effect of FOXP3. Collectively, the expression of tumor FOXP3 can inhibit the growth of HCC via suppressing c-Myc directly or indirectly via interacting with Smad2/3/4. Therefore, FOXP3 is a tumor suppressor in HCC.

FOX transcription factor family in hepatocellular carcinoma.

The pathogenesis of hepatocellular carcinoma (HCC) is a multistep process, involving the progressive accumulation of molecular alterations and transcriptomic alterations. The Forkhead-box (FOX) transcription factor family is characterized by its unique DNA binding domain (FKH or winged-helix domain). Human FOX family consists of about 17 subfamilies, at least 43 members. Some of them are liver-enriched transcription factors, suggesting that they may play a crucial role in the development or/and functions of the liver. Dysregulation of FOX transcription factors may contribute to the pathogenesis of HCC because they can activate or suppress the expression of various tumor-related molecules, and pinpoint different molecular and cellular events. Here we summarized, analyzed and discussed the status and the functions of the human FOX family of transcription factors in HCC, aiming to help the further development of them as potential therapeutic targets or/and diagnostic/prognostic markers for HCC.

Sargassum integerrimum inhibits oestrogen deficiency and hyperlipidaemia-induced bone loss by upregulating nuclear factor (erythroid-derived 2)-like 2 in female rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Oestrogen deficiency, high incidences of hyperlipidaemia (HLP) and accelerated bone loss frequently occur in postmenopausal women. There is an urgent need to develop functional foods or specific drugs to protect against bone loss induced by oestrogen deficiency with HLP. AIM OF THE STUDY: In this study, we investigated the potential inhibitory effects of Sargassum integerrimum (SI) on bone loss in an ovariectomized rat model with HLP. MATERIALS AND METHODS: The rats were treated for 12 weeks, and then, bone mineral density, bone biomechanical, bone microstructure, bone morphology, biomarkers of HLP oxidative stress and side effects were determined. Immunohistochemical staining and Western blot were performed to evaluate related protein expression. RESULTS: The femur bone mineral density increased (P < 0.05), and the microscopic structures (ratio of bone volume to total volume [BV/TV], connectivity density [Conn.D], trabecular number [Tb.N] and trabecular thickness [Tb.Th]) of the bone trabecula and mechanical properties (maximum and breaking load [ML and BL, respectively]) improved after SI treatment (P < 0.05). Furthermore, the levels of HLP biomarkers (total cholesterol, triglyceride and low-density lipoprotein) were significantly decreased (P < 0.05), whereas the levels of antioxidant markers (superoxide dismutase and total antioxidant capacity) were increased (P < 0.05). Similar results were obtained with immunohistochemical staining, whereas the Western blot assay showed that SI stimulated the expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) in bone. CONCLUSION: Our data indicate that rats exposed to SI treatment for 12 weeks did not exhibit noticeable side effects. In conclusion, SI suppressed bone loss induced by ovariectomized and the associated HLP in rats by activating Nrf2, which could be a promising treatment option for osteoporosis induced by oestrogen deficiency and HLP in postmenopausal women. TRANSLATIONAL SCOPE STATEMENT: Our study verified that SI prevented bone loss in rats with oestrogen deficiency with HLP by upregulating nuclear factor (erythroid-derived 2)-like 2. Furthermore, no side effect was observed after the long-term administration of SI. Those results suggested SI could be developed as a functional food or drug for postmenopausal osteoporosis induced by oestrogen deficiency with HLP.

The expression of FOXP3 and its role in human cancers.

FOXP3 is a transcription factor, which belongs to the family of FOX protein. FOXP3 was initially discovered in regulatory T cells and supposed to play a significant role in the process of regulatory T cell differentiation. Increasing evidence has shown that FOXP3 is also expressed in tumor cells. However, the results of tumor FOXP3 is inconsistent and even the opposite. In some types of human cancers, the expression of FOXP3 is upregulated, and it can promote the development of cancers, leading to a poor prognosis. While in some other types of cancers, it is a different story. The reason for the contradictory data is unknown. The discovery of FOXP3 isoforms, interaction between tumor cells and lymphocytes in the tumor microenvironment, subcellular location, and mutation of FOXP3 may provide some clues. In this review, we first summarize and analyze the recent development. The final section focuses on the regulation of FOXP3 expression.

Cancer stem cells in hepatocellular carcinoma: an overview and promising therapeutic strategies.

The poor clinical outcome of hepatocellular carcinoma (HCC) patients is ascribed to the resistance of HCC cells to traditional treatments and tumor recurrence after curative therapies. Cancer stem cells (CSCs) have been identified as a small subset of cancer cells which have high capacity for self-renewal, differentiation and tumorigenesis. Recent advances in the field of liver CSCs (LCSCs) have enabled the identification of CSC surface markers and the isolation of CSC subpopulations from HCC cells. Given their central role in cancer initiation, metastasis, recurrence and therapeutic resistance, LCSCs constitute a therapeutic opportunity to achieve cure and prevent relapse of HCC. Thus, it is necessary to develop therapeutic strategies to selectively and efficiently target LCSCs. Small molecular inhibitors targeting the core stemness signaling pathways have been actively pursued and evaluated in preclinical and clinical studies. Other alternative therapeutic strategies include targeting LCSC surface markers, interrupting the CSC microenvironment, and altering the epigenetic state. In this review, we summarize the properties of CSCs in HCC and discuss novel therapeutic strategies that can be used to target LCSCs.

Antiosteoporotic effects of Alpinia officinarum Hance through stimulation of osteoblasts associated with antioxidant effects.

BACKGROUND/OBJECTIVE: Alpinia officinarum Hance (AOH) is a traditional herbal medicine specific to south China and serves as a civil medication application of an antioxidant. Growing evidence demonstrates that antioxidants are beneficial for the treatment of osteoporosis. This study was designed to investigate the antiosteoporotic effects of total extracts from AOH in ovariectomised (OVX) rats and the different fractions in AOH on primary osteoblasts activities. METHODS: The total extract of AOH was extracted by refluxing using 95% ethanol, then the five fractions (F1-F5) were separated from AOH using thin-layer chromatography according to polarity from high to low, and the galangin content was determined using high performance liquid chromatography. In an in vivo study, 36 4-month-old female Sprague-Dawley rats were used as a Sham-operated group, OVX with vehicle (OVX), OVX with epimedium flavonoids (EF, 150 mg/kg/d), and OVX with AOH (AOH, 300 mg/kg/d), respectively. Daily oral administration started on Day 3 after OVX and lasted for 12 weeks. In the in vitro study, primary osteoblasts were incubated with AOH, galangin, and five different fractions (F1-F5) with or without hydrogen peroxide (H2O2), respectively. RESULTS: Treatment with AOH significantly attenuated osteopenia accompanied by a decreased percentage of osteoclast perimeter and bone formation rate per unit of bone surface, enhanced the bone strength, and prevented the deterioration of trabecular microarchitecture associated with a decrease in biochemical parameters of oxidative stress. Furthermore, treatment with AOH, F3, F4, and galangin increased cell viability, differentiation, and mineralisation in osteoblasts with or without H2O2 and rescued the deleterious effects of H2O2 on cell apoptosis and intracellular reactive oxygen species level. The effects on osteoblast formation were highly aligned with the amounts of flavonoids within AOH. CONCLUSION: These data demonstrate that ethanol extracts from AOH significantly reverse bone loss, partially by increasing bone formation, and by suppressing bone resorption associated with antioxidant effects, suggesting that AOH can be developed as a promising agent for the prevention and treatment of osteoporosis.