Stellanin: a promising medical drug for accompanying therapy in lung cancer treatment

Imprint

Elena M. Frantsiyants, Irina V. Kaplieva, Valerija A. Bandovkina*, Lidia K. Trepitaki, Ekaterina I. Surikova, Irina V. Neskubina, Ju-lija A. Pogorelova, Natalia D. Cheryarina, Alla I. Shikhlyarova, Dmitriy A. Kharagezov, Stanislav G. Vlasov, Roza G. Luganskaya, Ekaterina S. Bosenko. Stellanin: a promising medical drug for accompanying therapy in lung cancer treatment. Cardiometry; Issue 20; November 2021; p. 34-39; DOI: 10.18137/cardiome-try.2021.20.3439; Available from: issues/no20-november-2021/stellanin-a-promising-medical

Morbidity and mortality from malignant pathology are increasing every year all over the world [1]. Treatment of malignant neoplasms often is associated with high costs and expenditures. This makes it necessary to find new approaches to the rational use of the available health resources. Therefore, attention is paid to prevention as the main direction of the fight against cancer [2]. It is often impossible to identify external causes that contribute to the initiation of malignant pathology. Then, to prevent the development of tumors, various methods and medications are employed to normalize the altered functioning of the body. In particular, such methods include activation therapy [3], use of xenon [4] as well as chemoprophylaxis, i.e. a long-term use of a synthetic or a natural agent to avoid or exclude the formation and progression of neoplasms.

One of the measures of cancer chemoprophylaxis is the correction of the body regulatory systems functioning that has changed due to a growing tumor. It has been previously found that the performance of the hypothalamic-pituitary-thyroid system shows disorders or abnormalities in malignant pathology [5, 6]. It is known that one of the active components of the thyroid hormones, which are necessary for the proper functioning of all organs, is iodine. The specific mechanism of an action and an effect made by iodine on the body has not yet been fully clarified, but it is postulated as to be a sophisticated integral impact, including the participation of the thyroid hormones, transforming growth factor beta-1 (TGF-β1) and iodolipids, such as iodolactone or 2-iodohexadecanal (2-IHDA) [7].

Not so long ago, medical drug Stellanin has been synthesized in Russia, the active agent of which is 1,3-diethylbenzimidazolium triiodide, incorporating an iodine and an organic component in its structure. The developer of this new medical agent is LLC Pharm-preparat (Certificate RU LSR-000161/09, dd. January 16, 2009). Previously, the antitumor effect produced by Stellanin on human cell cultures and experimental tumors in mice has been reported [8; 9]. Based on the use of Stellanin, we have elaborated our own “Method for preventing metastatic lung damage in an experiment” [10]. According to the data obtained, rat males who received Stellanin according to the preventive schedule for 8 weeks lived more than 1.5 months longer after stopping treatment; there was no tumor process in the lungs. At the same time, those rats who did not receive Stellanin died within 5-6 weeks from severe respiratory insufficiency and cachexia due to total lung damage by the tumor process.

The aim herein is to study the effect of the above iodine-containing drug on the development of a tumor process in the lungs and the level of thyroid hormones in blood and the thyroid gland in experimental rat males.

Materials and methods

Our experimental studies were carried out in 24 outbred white rat males with an initial individual weight of 180-220 g delivered by the National Medical Research Centre of Oncology, the Ministry of Health of the Russian Federation. The research in animals was conducted in accordance with the Directive 86/609/EEC on the Protection of Animals Used for Experimental and Other Scientific Purposes and Order No. 267 “Approval of the Rules of Laboratory Practice” dated June, 19, 2003 issued by the Ministry of Health of the Russian Federation.

All rats were kept under the same conditions, 5 individuals in each standard plastic box unit, under the natural light conditions, at an ambient temperature of 22-26°C, with free access to water and food. The animals were divided into the following groups: a group of intact animals: 7 rats; a comparison group: 5 weeks after intravenous transplantation of sarcoma 45 (C45), 7 rats; a main test group: 5 weeks after intravenous transplantation of C45 and experimental preventive treatment with 1,3-diethylbenzimidazolium triiodide, 10 rats.

Modeling the malignant process in the lungs was reproduced by the method of Sidorenko Yu. S. et al. [11]. A tumor suspension of C45 cells in saline solution (in the volume of 0.5 ml per animal, in the amount of 2 * 106 tumor cells) was injected into the subclavian vein, the needle was removed, the injection site was tightly pressed for 1 minute with a cotton swab soaked in 70% alcohol with a small addition of iodine.

Within an hour after intravenous transplantation of the tumor, the rats of the main group were intra-gastrically administered Stellanin at a single dose of 0.4 mg/kg (the dose for humans converted for that for the rats), diluted in distilled water with a volume of 0.5 ml, according to an intermittent schedule: medication for 5 days followed by an interval for 2 days without medication; the duration of the exposure was 8 weeks. The rats from the comparison group were in-tragastrically injected with water in the same volume and according to the same schedule as Stellanin from day 1 [10].

The rats were decapitated 5 weeks after the tumor material was transplanted and the experimental treatment began. The study period was specified due to the peculiarities of the progression of the malignant process in the lungs in rats from the comparison group: upon expiration of 5-6 weeks, the rats died due to the total tumor lesion. Blood after decapitation of the rats was collected into dry sterile test tubes without preservatives, and serum was separated by centrifugation with a cold centrifuge at 2 thousand rpm for 10 minutes. The thyroid gland was harvested on ice using a 0.1 M potassium-phosphate buffer pH 7.4 containing 0.1% Tween 20 and 1% BSA, 10% organ homogenates were prepared. The content of free and combined forms of triiodothyronine (FT3 and T3) and thyroxine (FT4cb and T4) in serum, and homogenates was determined with the use of radioimmuneassay (test kits Immunotech, Czech Republic; analyzer Arian, Russia).

Statistical processing of the obtained results was carried out using the STATISTICA 10.0 software. The collected data were checked for compliance with the law of normal distribution (according to the Shapiro-Wilk criterion). When comparing samples with a normal distribution, the Student’s parametric criterion was applied, in another case the Mann – Whitney criterion was used. The results are presented as an arithmetic mean value ± standard error of the mean (M±m). The differences between the two samples were considered statistically significant at p<0.05.

Results

In the presented study, all rats belonging to the main experimental group had no signs of respiratory failure at slaughter 5 weeks upon completion of the experimental therapy with Stellanin. Upon performed necropsy, their lungs did not show differences from those found in the intact rats, and no histological signs of a tumor lesion were detected. In the rats included in the comparison group, some signs of respiratory failure were recorded in the form of dyspnea, tachypnea, intercostal retraction, cyanosis of the skin of the legs, the nose and the ears; 5 rats had nose bleeding. According to the autopsy findings, the lungs of the rats without the treatment were totally affected by the tumor nodes of a rounded shape, whitish-gray color, of different diameters, sometimes merging with each other; hemorrhages were found in the lung tissue; some patchy swollen areas of emphysema along with atelectasis regions were detected. The results obtained are found to be in agreement with those produced earlier [10].

The dynamics of the concentration of the thyroid hormones in the thyroid gland and serum in male rats with С45 intravenous transplantation with the experimental medication and without thereof is presented in Table 1 given herein.

5 weeks after the malignant process development in the lungs in the male rats from the comparison group, the level of FT4 decreased compared with the level in the intact animals: in the thyroid gland by 8.1 times and in the blood serum by 2.5 times, respectively (see Table 1 herein). Against the background of the Stel-lanin medication, the FT4 content in the rats of the main group was higher than that recorded in the comparison group: in the thyroid gland by 3.7 times and in the serum by 3.3 times, respectively. At the same time, the hormone content in the thyroid gland did not reach the normal values: it was 2.2 times less than the level found in the intact males, while in blood it exceeded the corresponding indicator of the intact animals by 1.6 times (p<0.05) (see Table 1 herein).

The amount of FT3 in serum and the thyroid gland, as well as FT4, 5 weeks after the intravenous C45 cell transplantation was lower than the levels recorded in the intact rats: in the thyroid gland by 21.3 times and in serum by 1.5 times, respectively (p<0.05). The experimental therapy did not change the hormone level, i.e. the amount of FT3 in the thyroid gland remained low, as it was the case with the comparison group, while the serum concentration of FT3 did not differ from the intact animal values and was 1.8 times (p<0.05) higher than reported for the rats without the above medication (see Table 1 herein).

In contrast to FT4, the level of which decreased in all the examined tissues in the males with a malignant process in the lungs, the T4 concentration changed in different ways: it decreased in the thyroid gland and, as a result, became 18.7 times less than the level detected in the intact rats and increased in serum, 1.5 times (p<0.05) exceeding the corresponding indicator in the intact animals (see Table 1 herein). Upon the effect made by Stellanin, the level of the hormone in the thyroid gland was stabilized: the concentration

Table 1

Concentration of hormones in the tissues in males with malignant lung damage and its suppression due to the Stellanin medication

Indicators and tissues Group of rats	Thyroid gland (per g of tissue)				Serum (per litre)
	FТ4 pmol	FТ3 pmol	Т4 (nmol)	Т4 (nmol)	FТ4 pmol	FТ3 pmol	Т4 (nmol)	Т4 (nmol)
Intact group	34.00	9.78	2.06	0.17	18.83	5.35	59.33	4.31
	±4.73	±1.76	±0.35	±0.04	±1.12	±0.44	±4.91	±0.42
Comparison group	4.20*	0.46*	0.11*	0.02*	7.56*	3.51*	87.84*	4.71
	±2.35	±0.21	±0.02	±0.001	±2.47	±0.32	±9.28	±0.70
Main group	15.43*,+	0.79*	1.67+	0.12+	24.98*,+	5.87+	100.86*	4.94
	±1.18	±0.22	±0.46	±0.03	±1.10	±0.37	±7.92	±0.21

Note: Statistically significant differences: *relative to the values of intact males; + relative to the values of males in the comparison group with a tumor lesion of the lungs.

of T4 did not differ from the value found in the intact animals, and it was 15.2 times higher than that in the males without treatment. However, the blood level of T4 in the rats of the main group remained as high as that found in the rats from the comparison group, and at the same time it was 1.7 times (p<0.05) higher than the value recorded in the intact rats (see Table 1 herein).

The content of T3 in the blood serum did not change in either case: against the background of the tumor growth and upon completion of the above experimental therapy. While the production of the above form of the hormone in the thyroid gland was reduced against the background of the development of the malignant process in the lung, the amount of T3 in the rats from the comparison group was 8.5 times less than that reported for the intact rats. In the rats of the main group treated with Stellanin, the level of T3 in the thyroid gland did not differ from the values found in the intact animals and, therefore, was 6.0 times higher than that in the rats from the comparison group (see Table 1 herein).

Discussion

A decrease in the concentration of free forms of thyroid hormones in blood, namely, hypotriodothy-roninemia and hypothyroxinemia, detected in rats 5 weeks after the transplantation of malignant cells into the subclavian vein, has indicated the formation of the “low T3/T4” syndrome, often concomitant with malignant pathology. It is noted that this syndrome is diagnosed with cancer of the breast, the lungs, the thyroid gland, the kidneys and other organs and is evidence for the severity of the improper condition, due to a pronounced disorder in the functioning of the hypothalamic-pituitary-thyroid axis [12; 13]. The pathophysiological basis for the development of this syndrome is an intensive “consumption” of thyroid hormones by malignant tissues with the development of the so-called abnormally consumption-related hypothyroidism. This is evidenced not only by low levels of free forms of triiodothyronine and thyroxine in blood, but also by a deficiency of thyroid hormones in the thyroid gland.

It has been found that thyroid hormones contribute to the neoangiogenesis and proliferation of malignant cells of many tumors [14]. The direct stimulating effect produced by the thyroid hormones on the proliferation of neoplastic cells “in vitro” is revealed with respect to lung adenocarcinoma, breast and prostate cancer. An interesting fact is that only thyroxine, but not triiodothyronine, administered externally, contributes to the development of the Lewis lung carcinoma as an experimental tumor in mice, whose malignant growth has been suppressed under hypothyroidism. Moreover, the stimulating effect of thyroxine is mediated not by direct stimulation of the Lewis carcinoma cells, but by enhancing neoangiogenesis through plasma membrane integrin avß3 [15].

The depletion of the thyroid hormone synthesis by the thyroid gland might be attributed to the intense central stimulation thereof. This is evidenced by an increase in the specific weight of the hypothalamus, where, as is known, the synthesis of thyrotropin-releasing hormone occurs, that has been identified by us in parallel studies. A low level of free forms of thyroid hormones in blood may enhance the hypothalamic synthesis of thyrotropin-releasing hormone according to the negative feedback principle. The sex hormones as well as IGF-I and VEGF may also stimulate the production of thyroxine in the thyroid gland [16].

In our experiments, intragastric administration of the organic iodine drug has suppressed the development of sarcoma 45 in the lungs in the rats. It is assumed that the mechanism of the antitumor action and effect made by Stellanin thereon at the molecular level is associated with the restoration of the functional activity of mitochondria, suppressed in a significant number of the tumor cells, and as a result, the initiation of the process of apoptosis of the oncotrans-formed cells [8;9;17]. However, iodine contained in 1,3-diethylbenzimidazolium iodide can be captured directly by the cells of the thyroid gland and modify the performance of the latter, which has been deteriorated under the progression of the experimental malignant process in the lungs.

We have found that 5 weeks after the start of experimental therapy Stellanin has inhibited the reduction of free forms of thyroid hormones in blood, as well as FT4 and combined forms of the thyroid hormones in the thyroid gland, typical for the development of a malignant process in the lungs without treatment. In other words, the synthetic activity of the thyroid gland has been restored in the rat males upon the effect produced by Stellanin, and the “low T3/T4” syndrome has been neutralized that bears witness to the normalization of the thyroid axis of the regulation. Apparently, the normalization of low levels of FT3 and FT4 in blood in the animals under the influence made by Stellanin according to the negative feedback principle “has eliminated” the central pituitary stimulation of the thyroid gland, which takes place at the stages of the formation of the tumor process in the lungs.

Thus, the effect made by Stellanin, which suppresses the malignant growth of С45 in the lungs, is accompanied by an elevation of low levels of thyroid hormones in the thyroid gland and blood. It is advisable to carry out further preclinical research of Stellanin aimed at its subsequent use in the accompanying therapy of patients with oncological pathology who have a risk of developing malignant lung damage.

Statement on ethical issues

Animal studies were carried out in compliance with the principles of humanity, which are set out in the European Community Directive (86/609 / EEC) and the Declaration of Helsinki. The study was approved at a meeting of the bioethical committee for work with animals of the Federal State Budgetary Institution “National Medical Research Center of Oncology” of the Ministry of Health of the Russian Federation dated January, 28, 2013, protocol of the ethical committee No. 3/3. All authors participating in the study signed informed consent to participate in the study.

Funding

The study was carried out as part of a government assignment and did not have any sponsorship.

Conflict of interest

None declared.

Author contributions

The authors read the ICMJE criteria for authorship and approved the final manuscript.