Apoptosis: life through planned cellular death regulating mechanisms, control systems, and relations with thyroid diseases

A Novel Inflammatory Marker for the Diagnosis of Hashimoto's Thyroiditis: Platelet-Count-to-Lymphocyte-Count Ratio

BACKGROUND

Hashimoto's thyroiditis (HT) is a chronic autoimmune thyroiditis that causes systemic inflammation in the body, leading to hypothyroidism and an enlargement of the thyroid gland.

OBJECTIVES

This study aims to reveal whether there is a relationship between Hashimoto's thyroiditis and the platelet-count-to-lymphocyte-count ratio (PLR), which is used as a new inflammatory marker.

METHODS

In this retrospective study, we compared the PLR of the euthyroid HT group and the hypothyroid-thyrotoxic HT group to the controls. We also evaluated the values of thyroid-stimulating hormone (TSH), free T4 (fT4), C-reactive protein (CRP), aspartate transaminase (AST), alanine transaminase (ALT), white blood cell count, lymphocyte count, hemoglobin, hematocrit, and platelet count in each group.

RESULTS

The PLR of the subjects with Hashimoto's thyroiditis was found to be significantly different from the control group (p < 0.001), with the rankings as follows: hypothyroid-thyrotoxic HT 177% (72-417) > euthyroid HT 137% (69-272) > control group 103% (44-243). In addition to the increased PLR values, an increase in CRP values was also observed, revealing a strong positive correlation between the PLR and CRP in the HT patients.

CONCLUSION

In this study, we found out that the PLR was higher in the hypothyroid-thyrotoxic HT and euthyroid HT patients than in a healthy control group.

Simulation Model for Hashimoto Autoimmune Thyroiditis Disease

Hashimoto thyroiditis (HT) is a pathology that often causes a gradual thyroid insufficiency in affected patients due to the autoimmune destruction of this gland. The cellular immune response mediated by T helper lymphocytes TH1 and TH17 can induce the HT disease. In this pathologic condition, there is an imbalance between the TH17 and Treg lymphocytes as well as a gut microbiota dysfunction. The objective of this work was to describe the interactions of the cell subpopulations that participate in HT. To achieve this goal, we generated a mathematical model that allowed the simulation of different scenarios for the dynamic interaction between thyroid cells, the immune system, and the gut microbiota. We used a hypothetical-deductive design of mathematical modeling based on a system of ordinary differential equations, where the state variables are the TH1, TH17, and Treg lymphocytes, the thyrocytes, and the bacteria from gut microbiota. This work generated a compartmental model of the cellular immune response occurring in the thyroid gland. It was observed that TH1 and TH17 lymphocytes could increase the immune cells' activity, as well as activate effector cells directly and trigger the apoptosis and inflammation processes of healthy thyrocytes indirectly. Likewise, the model showed that a reduction in Treg lymphocytes could increase the activity of TH17 lymphocytes when an imbalance of the gut microbiota composition occurred. The numerical results highlight the TH1, TH17, and bacterial balance of the gut microbiota activities as important factors for the development of HT disease.

Morphological changes of the thyroid gland as a new radiographic marker for lung cancer treatment efficacy of immune checkpoint inhibitors

BACKGROUND

Fully human IgG4 programmed cell death-1 (PD-1) immune checkpoint inhibitors are effective against non-small-cell lung cancer (NSCLC). PD-1-targeted antibodies induce autoimmune adverse events that are not caused by conventional chemotherapy.

PURPOSE

To clarify the association between morphological changes of the thyroid gland and the efficacy of PD-1 immune checkpoint inhibitor treatment for lung cancer.

MATERIAL AND METHODS

The study enrolled 29 patients who received PD-1 immune checkpoint inhibitor treatment. The thyroid volume was measured using computed tomography (CT) at the following three timepoints: pre-treatment (baseline); three months after the initial administration (early treatment); and at the last CT scan during the observation period (late treatment). Thyroid volume ratios were calculated as follows: early treatment/baseline thyroid volume at CT (E/B-CT ratio) and late treatment/baseline thyroid volume at CT (L/B-CT ratio). Thyroid dysfunction was assessed according to thyroid hormone levels.

RESULTS

The E/B-CT ratio was significantly higher in patients with adverse events of grade 3 or higher than in the other patients (P = 0.013). The L/B-CT ratio was significantly lower in patients with thyroid dysfunction than in those without thyroid dysfunction (P = 0.001). Complete response (CR) was achieved in three patients at the time of the final CT. The E/B-CT ratio was significantly higher in patients with CR than in the other patients (1.48 vs. 0.99, P = 0.029).

CONCLUSION

Changes in thyroid volume after administration of PD-1 immune checkpoint inhibitors might be a useful radiographic marker of therapeutic efficacy in patients with lung cancer.

Association of Pro-apoptotic Bad Gene Expression Changes with Benign Thyroid Nodules

BACKGROUND/AIM

This study aimed to investigate the role of the mitochondrial apoptotic pathway in benign thyroid nodules.

MATERIALS AND METHODS

Paired samples of nodular and normal tissues were collected from 26 patients with nodular goiters undergoing thyroidectomy. Variable expression of Bcl-2, Bax and Bad genes were evaluated by quantitative PCR.

RESULTS

Expression level of Bad gene in nodules was found to be significantly decreased compared to normal tissues (p=0.049). A positive correlation was observed between nodule size and Bad expression levels (correlation coefficient=0.563, p=0.004); and this correlation was stronger in hot nodules (n=18, correlation coefficient=0.689, p=0.003). No significant difference was observed between nodular and normal tissue expressions of Bax and Bcl-2.

CONCLUSION

These results suggest that Bad expression correlates with the size of benign thyroid nodules and also its relatively lower expression in nodules, warrant further investigation.

Denosumab Therapy for Refractory Hypercalcemia Secondary to Squamous Cell Carcinoma of Skin in Epidermolysis Bullosa

Hypercalcemia secondary to malignancy is rare in children and the majority is caused by tumor-produced parathyroid hormone-related protein (PTHrP). We report a case of hypercalcemia refractory to bisphosphonate and corticosteroid therapy, but responsive to denosumab. A 17-year-old boy with epidermolysis bullosa (EB) and advanced squamous cell carcinoma (SCC) of the left leg was referred with severe hypercalcemia (serum calcium, 4.2 mmol/L). The serum parathyroid hormone (PTH) was 0.7 pmol/L (1.1 - 6.9 pmol/L). The hypercalcemia was initially managed with hyperhydration, prednisolone and pamidronate. Following two infusions of pamidronate (1 mg/kg/dose), serum calcium fell to 2.87 mmol/L. However the hypercalcemia relapsed within a week (serum calcium, 3.61 mmol/L) needing aggressive management with intravenous fluids, prednisolone and two further doses of pamidronate. The serum calcium fell to 2.58 mmol/L over the first 4 days, but rose to 3.39 mmol/L 3 days later. As the hypercalcemia was refractory to bisphosphonate treatment, a trial dose of subcutaneous denosumab (60 mg) was administered following which the calcium fell to 2.86 mmol/L within 24 h and normocalcemia was sustained 4 days later. We report a case of refractory hypercalcemia secondary to malignant SCC, which responded well to denosumab therapy. To our knowledge, this is the first case of hypercalcemia of malignancy in an adolescent managed with denosumab.

Studies on anti-tumour activities of pseudolaric acid-B (PLAB) and its mechanism of action

Pseudolaric acid-B (PLAB), a diterpene acid, was isolated from the root and trunk barks of Pseudolarix kaempferi. It showed antifungal and anti-fertility effects as well as cytotoxic activities in previous studies. The present study investigates cytotoxic activity on cultured human cancer cells, inhibition on the growth of transplantable tumours in mice and the mechanism of these actions. The experimental results showed that PLAB had potent cytotoxic effects on cancer cells derived from different tissues. MTT assay showed that its IC50 towards these tumour cells was 0.17 to 5.20 micromol/L, and towards one normal human kidney proximal tubular epithelial cell (HKC) was 5.77 micromol/L. Furthermore, the results of cell growth curve and colony formation of cancer cells matched the above results. The results in vivo demonstrated that PLAB significantly inhibited the growth of transplantable tumours, such as Lewis lung cancer and hepatocarcinoma 22 (H22) in mice. The inhibitory rate to H22 was 14.4% and 40.1%, and to Lewis lung cancer reached 39.1% and 47.0%, when PLAB was given by intraperitoneal injection (i.p.) at a dose of 30 mg/kg/day and 60 mg/kg/day for 10 days, respectively. It is suggested that PLAB also showed obvious anticancer activity in vivo. Inducing apoptosis by PLAB in HeLa cells was assessed by various morphological and biochemical characteristics, including cell shrinkage, chromatin condensation, membrane blebbing, formation of apoptotic bodies, and internucleosomal DNA fragmentation. A typical 'sub-G1 peak' was also checked through flow cytometry. These results were accompanied by up-regulating P53, down-regulating Bcl-2 and activating Caspase-3, which was revealed by Western blotting. PLAB also caused cell cycle arrest to G2/M phase in a dose-dependent manner. The experiments suggest that PLAB is a new potent anti-tumour agent.

Immunogenetics of Hashimoto's thyroiditis

Hashimoto's thyroiditis (HT) is an organ-specific T-cell mediated disease. It is a complex disease, with a strong genetic component. To date, significant progress has been made towards the identification and functional characterization of HT susceptibility genes. In this review, we will summarize the recent advances in our understanding of the genetic input to the pathogenesis of HT.

Doxorubicin induces Fas-mediated apoptosis in human thyroid carcinoma cells

Doxorubicin remains the most extensively used drug in the chemotherapy of thyroid cancer. However, drug resistance often limits the efficacy of chemotherapy in clinical practice. Several anticancer drugs exert their cytotoxic effect by triggering Fas-mediated apoptosis in some cell types. However, no investigations have been conducted to determine whether doxorubicin causes apoptosis in thyroid carcinomas. In the present study, we assessed the cytotoxic and apoptotic effects of doxorubicin on two thyroid cancer cell lines (FTC 238 and FTC 133). Cytotoxic effects of doxorubicin were evaluated by a 3-(4,5 dimethylthiazol-2yl) 2-5 diphenyltetrazolium bromide (MTT) assay. Apoptosis was quantified by fluorescein isothiocyanate-conjugated annexin V/flow cytometric analysis and by DNA fragmentation. Fas expression was measured by flow cytometric analysis. After a 24-hour incubation, doxorubicin induces a dose-dependent cytotoxicity in the two cell lines. Treatment with doxorubicin (0.5 and 1 microM) for 24 hours induced cell apoptosis and upregulated Fas expression. A significant correlation was found between the fluorescence intensity values obtained with annexin V staining and those observed for Fas expression (r = 0.996; p < 0.001 or r = 0.957; 0.02 < p < 0.05 for FTC 238 or FTC 133 cells, respectively). In conclusion, doxorubicin exerts its cytotoxic effects, at least partly, through Fas-mediated apoptosis in thyroid cancer cells. These results may have clinical implications for thyroid cancer therapy.