There is evidence, both in vitro and in vivo, that receptor tyrosine kinases play a key role in the formation and progression of human cancer. In particular, the insulin-like growth factor receptor (IGF-IR), a tyrosine kinase receptor for IGF-I and IGF-II, has been well documented in cell culture, animal studies, and humans to play a role in malignant transformation, progression, protection from apoptosis, and metastasis. In addition, the hormone insulin (which is very closely related to the IGFs) and its tyrosine kinase receptor (the IR, which is very closely related to the IGR-IR) have been documented both in vitro and in vivo to play a key role in cancer biology. Indeed, several epidemiological studies have shown that insulin resistance status, characterized by hyperinsulinaemia, is associated with an increased risk for a number of malignancies, including carcinomas of the breast, prostate, colon and kidney. Recent data have elucidated some molecular mechanisms by which IR is involved in cancer. IR is over-expressed in several human malignancies. Interestingly, one of the two IR isoform (IR-A) is especially over-expressed in cancer. IR-A is the IR foetal isoform and has the peculiar characteristic to bind not only insulin but also IGF-II. In addition, the IR contributes to formation of hybrid receptors with the IGF-IR (HR). By binding to hybrid receptors, insulin may stimulate specific IGF-IR signalling pathways. Over-expression of IR-A is, therefore, a major mechanism of IGF system over-activation in cancer. In this respect, IR-A isoform and hybrid receptors should be regarded as potential molecular targets, in addition to IGF-IR, for novel anti-cancer therapy. These findings may have important implications for both the prevention and treatment of common human malignancies. They underline the concept that hyperinsulinaemia, associated with insulin resistance and obesity, should be treated by changes in life style and/or pharmacological approaches to avoid an increased risk for cancer. Moreover, native insulin and insulin analogue administration should be carefully evaluated in terms of the possible increase in cancer risk.

There is growing concern regarding the health and safety issues of endocrine-disrupting chemicals (EDCs). Long-term exposure to EDCs has alarming adverse health effects through both hormone-direct and hormone-indirect pathways. Non-chemical agents, including physical agents such as artificial light, radiation, temperature, and stress exposure, are currently poorly investigated, even though they can seriously affect the endocrine system, by modulation of hormonal action. Several mechanisms have been suggested to explain the interference of EDCs with hormonal activity. However, difficulty in quantifying the exposure, low standardization of studies, and the presence of confounding factors do not allow the establishment of a causal relationship between endocrine disorders and exposure to specific toxic agents. In this review, we focus on recent findings on the effects of EDCs and hormone system modulators on the endocrine system, including the thyroid, parathyroid glands, adrenal steroidogenesis, beta-cell function, and male and female reproductive function.

Curcumin is a polyphenol compound extracted from the rhizome of Curcuma longa Linn (family Zingiberaceae) commonly used as a spice to color and flavor food. Several preclinical studies have suggested beneficial roles for curcumin as an adjuvant therapy in free radical-based diseases, mainly neurodegenerative disorders. Indeed, curcumin belongs to the family of hormetins and the enhancement of the cell stress response, mainly the heme oxygenase-1 system, is actually considered the common denominator for this dual response. However, evidence-based medicine has clearly demonstrated the lack of any therapeutic effect of curcumin to contrast the onset or progression of neurodegeneration and related diseases. Finally, the curcumin safety profile imposes a careful analysis of the risk/benefit balance prior to proposing chronic supplementation with curcumin.

IL-4, a pleiotropic cytokine mainly produced by activated helper T lymphocytes type 2 (Th2), is known to protect thyroid cells from autoimmune damage. Acting via its receptors (IL-4Ralpha), IL-4 has antiproliferative and apoptotic effects in many malignancies. Its effect in thyroid cancer is unknown. We found that surgical specimens of thyroid carcinomas express both IL-4Ralpha and IL-4 in the majority of cases. Thyroid glands affected by Graves' disease also express IL-4. We also studied a panel of eight thyroid cancer cell lines from different histotypes and found that thyroid cancer cells express high levels of IL-4Ralpha although they do not express IL-4. We then compared the biological effects of IL-4 in TPC-1, a thyroid cancer cell line, and in MCF-7 breast cancer cells. IL-4 very weakly stimulated thyroid cancer cell proliferation, but it was very effective in protecting thyroid cancer cells from apoptosis induced by staurosporin. The protective effect of IL-4 was similar in magnitude to that of IGF-I and was associated with up-regulation of the antiapoptotic molecule Bcl-2 and weak down-regulation of the proapoptotic molecule Bax. Moreover, IL-4 slightly potentiated the survival effect of IGF-I. In contrast, IL-4 reduced growth and induced apoptosis in MCF-7 cells. Taken together, these findings suggest that thyroid cancer cells receive significant protection from apoptosis by IL-4 produced in the thyroid gland by activated T lymphocytes when concomitant Graves' disease is present.

Context: Ultrasound-based risk stratification systems (Thyroid Imaging Reporting and Data Systems (TIRADSs)) of thyroid nodules (TNs) have been implemented in clinical practice worldwide based on their high performance. However, it remains unexplored whether different TIRADSs perform uniformly across a range of TNs in routine practice. This issue is highly relevant today, given the ongoing international effort to establish a unified TIRADS (i.e. I-TIRADS), supported by the leading societies specializing in TNs. The study aimed to conduct a direct comparison among ACR-, EU-, and K-TIRADS in the distribution of TNs: (1) across the TIRADS categories, and (2) based on their estimated cancer risk. Methods: A search was conducted on PubMed and Embase until June 2023. Original studies that sequentially assessed TNs using TIRADSs, regardless of FNAC indication, were selected. General study characteristics and data on the distribution of TNs across TIRADSs were extracted. Results: Seven studies, reporting a total of 41,332 TNs, were included in the analysis. The prevalence of ACR-TIRADS 1–2 was significantly higher than that of EU-TIRADS 2 and K-TIRADS 2, with no significant difference observed among intermediate- and high-risk categories of TIRADSs. According to malignancy risk estimation, K-TIRADS often classified TNs as having more severe risk, ACR-TIRADS as having moderate risk, and EU-TIRADS classified TNs as having lower risk. Conclusion: ACR-, EU-, and K-TIRADS assess TNs similarly across their categories, with slight differences in low-risk classifications. Despite this, focusing on cancer risk estimation, the three TIRADSs assess TNs differently. These findings should be considered as a prerequisite for developing the I-TIRADS.

Most undifferentiated thyroid carcinomas express p53 mutants and thereafter, are very resistant to chemotherapy. p53 reactivation and induction of massive apoptosis (Prima‐1) is a compound restoring the tumor‐suppressor activity of p53 mutants. We tested the effect of Prima‐1 in thyroid cancer cells harboring p53 mutations. Increasing doses of Prima‐1 reduced viability of thyroid cancer cells at a variable extent (range 20–80%). Prima‐1 up‐regulated p53 target genes (p21^WAF1, BCL2‐associated X protein (Bax), and murine double minute 2 (MDM2)), in BC‐PAP and Hth‐74 cells (expressing D259Y/K286E and K286E p53 mutants) but had no effect in SW1736 (p53 null) and TPC‐1 (expressing wild‐type p53) thyroid cancer cells. Prima‐1 also increased the cytotoxic effects of either doxorubicin or cisplatin in thyroid cancer cells, including the chemo‐resistant 8305C, Hth‐74 and BC‐PAP cells. Moreover, real‐time PCR and Western blot indicated that Prima‐1 increases the mRNA of thyroid‐specific differentiation markers in thyroid cancer cells. Fluorescence‐activated cell sorting analysis revealed that Prima‐1 effect on thyroid cancer cells occurs via the enhancement of both cell cycle arrest and apoptosis. Small interfering RNA experiments indicated that Prima‐1 effect is mediated by p53 mutants but not by the p53 paralog p73. Moreover, in C‐643 thyroid cancer cells, forced to ectopically express wild‐type p53, Prima‐1 prevented the dominant negative effect of double K248Q/K286E p53 mutant. Finally, co‐IP experiments indicated that in Hth‐74 cells Prima‐1 prevents the ability of p53 mutants to sequestrate the p53 paralog TAp73. These in vitro studies imply that p53 mutant reactivation by small compounds may become a novel anticancer therapy in undifferentiated thyroid carcinomas.