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

New insights into the mechanism of resistance to lenvatinib and strategies for lenvatinib sensitization in hepatocellular carcinoma

Lenvatinib is a multikinase inhibitor that suppresses vascular endothelial growth factor receptor (VEGFR), fibroblast growth factor receptor (FGFR), platelet-derived growth factor receptor α (PDGFRα), as well as the proto-oncogenes RET and KIT. Lenvatinib has been approved by the US Food and Drug Administration (FDA) for the first-line treatment of hepatocellular carcinoma (HCC) due to its superior efficacy when compared to sorafenib. Unfortunately, the development of drug resistance to lenvatinib is becoming increasingly common. Thus, there is an urgent need to identify the factors that lead to drug resistance and ways to mitigate it. We summarize the molecular mechanisms that lead to lenvatinib resistance (LR) in HCC, which involve programmed cell death (PCD), translocation processes, and changes in the tumor microenvironment (TME), and provide strategies to reverse resistance.

Ferroptosis in thyroid cancer: Potential mechanisms, effective therapeutic targets and predictive biomarker

Thyroid cancer is a prevalent endocrine malignancy whose global incidence has risen over the past several decades. Ferroptosis, a regulated form of cell death distinguished by the excessive buildup of iron-dependent lipid peroxidates, stands out from other programmed cell death pathways in terms of morphological and molecular characteristics. Increasing evidence suggests a close association between thyroid cancer and ferroptosis, that is, inducing ferroptosis effectively suppresses the proliferation of thyroid cancer cells and impede tumor advancement. Therefore, ferroptosis represents a promising therapeutic target for the clinical management of thyroid cancer in clinical settings. Alterations in ferroptosis-related genes hold potential for prognostic prediction in thyroid cancer. This review summarizes current studies on the role of ferroptosis in thyroid cancer, elucidating its mechanisms, therapeutic targets, and predictive biomarkers. The findings underscore the significance of ferroptosis in thyroid cancer and offer valuable insights into the development of innovative treatment strategies and accurate predictors for the thyroid cancer.

Brusatol attenuated proliferation and invasion induced by KRAS in differentiated thyroid cancer through inhibiting Nrf2

BACKGROUND

Poorly differentiated thyroid cancer (PDTC) and anaplastic thyroid cancer (ATC) can be developed from differentiated thyroid cancer, and this dedifferentiated transformation leads to poor prognosis and high mortality. The role of Nrf2 in the dedifferentiation of differentiated thyroid cancer (DTC) induced by KRAS remains unclear.

METHODS AND MATERIALS

In this study, two DTC cell lines, BCPAP and WRO, were used to evaluate the function of Nrf2 in the dedifferentiation caused by wild-type KRAS (KRAS-WT) and G12V point mutation KRAS (KRAS-G12V).

RESULTS

The overexpression of KRAS-WT and KRAS-G12V increased the proliferative and invasive ability of BCPAP and WRO cells. Aggressive morphology was observed in KRAS-WT and KRAS-G12V overexpressed WRO cells. These results suggested that overexpression of KRAS-WT or KRAS-G12V may induce dedifferentiation in DTC cells. The expression of Nrf2 was increased by KRAS-WT and KRAS-G12V in DTC cells. In addition, compared with normal thyroid tissues, the expression of Nrf2 protein was considerably higher in thyroid cancer tissues on immunohistochemistry (IHC) staining, and the increased expression of Nrf2 indicated a poor prognosis of thyroid cancer. These results indicated that Nrf2 is the KRAS downstream molecule in thyroid cancer. Functional studies showed that the Nrf2 inhibitor Brusatol counteracted the proliferative and invasive abilities induced by KRAS-WT and KRAS-G12V in BCPAP and WRO cells. In addition, the xenograft assay further confirmed that Brusatol inhibits tumor growth induced by KRAS-WT and KRAS-G12V.

CONCLUSION

Collectively, this study suggests that Nrf2 could be a promising therapeutic target in KRAS-mediated dedifferentiation of thyroid cancer.

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.

Higher Levels of Plasma Fetuin-A, Nrf2, and Cytokeratin 18 in Patients with Hashimoto's Disease

Objectives

Fetuin-A is a protein that exhibits proatherogenic, pro-inflammatory, and anti-inflammatory effects with increased insulin resistance and adipocyte dysfunction. The nuclear factor erythroid 2-related factor (Nrf2) is a transcription factor that is crucial for protecting cells against oxidative damage. As a cell death product, cytokeratin 18 (CK18) levels increase during necrosis and apoptosis of both normal and tumor cells. We analyzed the plasma levels of three biomarkers based on the hypothesis that they might be related to some pathophysiological pathways in Hashimoto's disease.

Methods

We compared 34 female patients with overt hypothyroidism due to Hashimoto's disease (Group 1) with 34 age-matched healthy females (Group 2). For comparison, plasma levels of thyroid-stimulating hormone (TSH), fetuin-A, Nrf2, and CK18 were measured in all participants.

Results

In group 1, the mean TSH levels (31.4±15.3) were significantly higher than those in group 2 (2.6±1.0) (p<0.001). The levels of mean fetuin-A (606.7±34.2) and Nrf2 (1.3±0.6) were found to be significantly higher in group 1 than in group 2 (440.0±34.2 vs. 0.7±0.2) (p<0.001 for both). CK18 levels in group 1 (0.36±0.13) were also significantly higher than in group 2 (0.26±0.16) (p=0.020). A significant correlation was observed between TSH levels and fetuin-A (r=0.401, p=0.001).

Conclusion

Increased levels of fetuin-A, Nrf2, and CK18 may be a consequence or cause of the pathophysiological pathways of Hashimoto's disease. The clinical significance of increased levels of these biomarkers requires further investigation.

ALKBH5 inhibits thyroid cancer progression by promoting ferroptosis through TIAM1-Nrf2/HO-1 axis

As a critical catalytic subunit of N6-methyladenosine (m6A) modification in messenger RNA, ALKBH5 has been reported to affect the progression of numerous tumors. However, the functions and mechanisms of ALKBH5 in thyroid cancer remain largely unknown. Relative mRNA and protein levels in thyroid cancer tissues and cells were detected by qRT-PCR and western blot, respectively. The proliferation and viability were evaluated using colony formation and CCK-8 assays. Intracellular iron level was measured by an iron colorimetric assay kit. ROS level was determined using CellRox Green reagent. TIAM1 mRNA m6A level was detected by MeRIP. Xenograft tumor growth was performed to examine the role of ALKBH5 in thyroid tumor growth in vivo. ALKBH5 was decreased in thyroid cancer tissues and cells. ALKBH5 overexpression inhibited thyroid cancer cell proliferation and increased the levels of Fe²⁺ and ROS and reduced the proteins expression of GPX4 and SLC7A11. Furthermore, overexpression of ALKBH5 inhibited TIAM1 expression by m6A modification, and overexpression of TIAM1 reversed the regulatory of oe-ALKBH5 on cell proliferation and ferroptosis in thyroid cancer. In addition, TIAM1 was elevated in thyroid cancer, and TIAM1 knockdown repressed thyroid cancer cell proliferation and promoted ferroptosis through regulating Nrf2/HO-1 axis. In addition, in vivo evidences also showed that ALKBH5 suppressed thyroid cancer progression by decreasing the m6A level of TIAM1. Our findings suggested that ALKBH5 inhibited thyroid cancer progression by inducing ferroptosis through m6A-TIAM1-Nrf2/HO-1 axis, suggesting ALKBH5 might be a potential target molecule for the treatment and diagnosis of thyroid cancer.

Emerging roles of Keap1/Nrf2 signaling in the thyroid gland and perspectives for bench-to-bedside translation

The signaling pathway centered on the transcription factor nuclear erythroid factor 2-like 2 (Nrf2) has emerged during the last 15 years as a target for the prevention and treatment of diseases broadly related with oxidative stress such as cancer, neurodegenerative and metabolic diseases. The roles of Nrf2 are expanding beyond general cytoprotection, and they encompass its crosstalk with other pathways as well as tissue-specific functions. The thyroid gland relies on reactive oxygen species for its main physiological function, the synthesis and secretion of thyroid hormones. A few years ago, Nrf2 was characterized as a central regulator of the antioxidant response in the thyroid, as well as of the transcription and processing of thyroglobulin, the major thyroidal protein that serves as the substrate for thyroid hormone synthesis. Herein, we summarize the current knowledge about the roles of Nrf2 in thyroid physiology, pathophysiology and disease. We focus specifically on the most recent publications in the field, and we discuss the implications for the preclinical and clinical use of Nrf2 modulators.

Neferine Exerts Ferroptosis-Inducing Effect and Antitumor Effect on Thyroid Cancer through Nrf2/HO-1/NQO1 Inhibition

Thyroid cancer is the most prevalent endocrine malignancy with an increasing incidence in the past few decades. Neferine possesses various pharmacological activities, which have been applied in diverse disease models, including various tumors. However, the detailed effect and mechanism of neferine on thyroid cancer are still unclear. In the current study, the viability of IHH-4 and CAL-62 cells was examined by the CCK-8 assay. The effect of neferine on the proliferation, apoptosis, invasion, vascular endothelial growth factor (VEGF), epithelial-mesenchymal transition (EMT), and ferroptosis was evaluated by CCK-8, flow cytometry, western blot, and spectrophotometry assays. Mechanically, the expressions levels of Nrf2/HO-1/NQO1 signaling were first determined by a western blot, which was then verified by Nrf2 overexpression. In vivo validation was also conducted on BALB/c nude mice with an inoculation dose of 2 × 106 IHH-4 cells. The results showed that neferine repressed the viability of both IHH-4 and CAL-62 cells both in a dose-dependent way and in a time-dependent fashion, in which the IC50 value of neferine on IHH-4 and CAL-62 cells was 9.47 and 8.72 μM, respectively. Besides, neferine enhanced apoptosis but suppressed invasion, angiogenesis, and EMT of IHH-4 and CAL-62 cells. Moreover, neferine induced the activation of ferroptosis in thyroid cancer cells. Notably, it was revealed that the Nrf2/HO-1/NQO1 pathway was strongly associated with the effect of neferine on the modulation of thyroid cancer. Furthermore, these outcomes were validated in xenografted mice. Therefore, neferine exerted an antitumor effect and ferroptosis-inducing effect on thyroid cancer via inhibiting the Nrf2/HO-1/NQO1 pathway.