Apoptosis indices in liver cell mitochondria in B16/F10 melanoma growing in presence of chronic neurogenic pain

Введение. Печень по количеству, плотности митохондрий один из самых богатых органов, который также является критическим местом для множества метаболических путей. Цель исследования - изучение показателей апоптоза в митохондриях печени самок мышей линии С57ВL/6 при самостоятельном росте меланомы В16/F10 и на фоне коморбидной патологии - хронической нейрогенной боли. Методика. В эксперименте использовали мышей-самок (n=168) линии С57ВL/6. Группы: интактная (n=21); контрольная (n=21) - создание модели хронической нейрогенной боли (ХНБ), путем двусторонней перевязки седалищных нервов; группа сравнения (n=63) - подкожная трансплантация меланомы B16/F10; основная группа (ХНБ+B16/F10) (n=63) - подкожная трансплантация меланомы В16/F10 через 3 нед после моделировия ХНБ. В митохондриях печени методом ИФА определяли концентрацию: цитохрома С (нг/г белка), каспазы 9 (нг/г белка), Bcl-2 (нг/г белка), AIF (нг/г белка), кальция (Са 2+) (мМоль/г белка). Результаты. В митохондриях клеток печени через 1 нед роста меланомы относительно интактных значений фиксировали нарастание уровней AIF в 2,2 раза, цитохрома С в 1,7 раза (р<0,05) и снижение каспазы 9 в 2,0 раза; через 3 нед - падение кальция в 4,7 раза, AIF в 7,1 раза и цитохрома С в 1,7 раза (р<0,05) и накопление каспазы 9 - 1,6 раза (р<0,05). Развитие опухоли при ХНБ через 1 нед сопровождалось уменьшением концентрации AIF в 29,3 раза и цитохрома С в 2,0 раза по сравнению с контрольными значениями (ХНБ). Через 3 недели роста меланомы на фоне ХНБ фиксировали снижение уровней AIF в 6,6 раза, цитохрома С в 4,7 раза и кальция в 32,8 раза, уровень каспазы 9, напротив, повышался в 1,5 раза (р<0,05). Заключение. Наличие коморбидной патологии - ХНБ при опухолевом процессе способствует раннему возникновению нарушений в электронно-транспортной цепи митохондрий клеток печени. Background. The liver is one of the richest organs in terms of the number and density of mitochondria; it is also a critical site for many metabolic pathways. The aim of the study was to analyze indicators of apoptosis in liver mitochondria in female С57ВL/6 mice with B16/F10 melanoma growing alone and in presence of chronic neurogenic pain. Methods. Female С57ВL/6 mice (n=168) were studied. Animals were divided into groups: intact group (n=21); controls (n=21) with a model of chronic neurogenic pain (CNP) created by bilateral sciatic nerve ligation; comparison group (n=63) with subcutaneous transplantation of B16/F10 melanoma; main group (CNP+B16/F10) (n=63) with subcutaneous transplantation of B16/F10 melanoma 3 wks after modeling CNP. Cytochrome C (ng/g protein), caspase-9 (ng/g protein), Bcl-2 (ng/g protein), AIF (ng/g protein), and calcium (Ca2+) (mmol/g protein) were measured by ELISA in the liver mitochondrial fraction. Results. After 1 wk of melanoma growth, AIF increased by 2.2 times, cytochrome C increased by 1.7 times (p<0.05), and caspase-9 decreased by 2.0 times compared to the intact group values. After 3 wks, calcium decreased by 4.7 times, AIF by 7.1 times, cytochrome C by 1.7 times (p<0.05), and caspase-9 increased by 1.6 times (p<0.05). After 1 wk, tumor development in the presence of CNP was accompanied by decreases in AIF by 29.3 times and cytochrome C by 2.0 times, compared to control CNP values. After 3 wks of melanoma growth in presence of CNP, AIF decreased by 6.6 times, cytochrome C by 4.7 times, and calcium by 32.8 times. Caspase-9, on the contrary, increased by 1.5 times (p<0.05). Conclusions. The presence of CNP comorbidity during the tumor development facilitates earlier occurrence of disorders in the electron transport chain of hepatocyte mitochondria.

Extracellular Matrix Remodeling by Fibroblast-MMP14 Regulates Melanoma Growth

Maintaining a balanced state in remodeling the extracellular matrix is crucial for tissue homeostasis, and this process is altered during skin cancer progression. In melanoma, several proteolytic enzymes are expressed in a time and compartmentalized manner to support tumor progression by generating a permissive environment. One of these proteases is the matrix metalloproteinase 14 (MMP14). We could previously show that deletion of MMP14 in dermal fibroblasts results in the generation of a fibrotic-like skin in which melanoma growth is impaired. That was primarily due to collagen I accumulation due to lack of the collagenolytic activity of MMP14. However, as well as collagen I processing, MMP14 can also process several extracellular matrices. We investigated extracellular matrix alterations occurring in the MMP14-deleted fibroblasts that can contribute to the modulation of melanoma growth. The matrix deposited by cultured MMP14-deleted fibroblast displayed an antiproliferative and anti-migratory effect on melanoma cells in vitro. Analysis of the secreted and deposited-decellularized fibroblast’s matrix identified a few altered proteins, among which the most significantly changed was collagen XIV. This collagen was increased because of post-translational events, while de novo synthesis was unchanged. Collagen XIV as a substrate was not pro-proliferative, pro-migratory, or adhesive, suggesting a negative regulatory role on melanoma cells. Consistent with that, increasing collagen XIV concentration in wild-type fibroblast-matrix led to reduced melanoma proliferation, migration, and adhesion. In support of its anti-tumor activity, enhanced accumulation of collagen XIV was detected in peritumoral areas of melanoma grown in mice with the fibroblast’s deletion of MMP14. In advanced human melanoma samples, we detected reduced expression of collagen XIV compared to benign nevi, which showed a robust expression of this molecule around melanocytic nests. This study shows that loss of fibroblast-MMP14 affects melanoma growth through altering the peritumoral extracellular matrix (ECM) composition, with collagen XIV being a modulator of melanoma progression and a new proteolytic substrate to MMP14.

The BRD9/7 Inhibitor TP-472 Blocks Melanoma Tumor Growth by Suppressing ECM-Mediated Oncogenic Signaling and Inducing Apoptosis

Melanoma accounts for the majority of all skin cancer-related deaths and only 1/3rd of melanoma patients with distal metastasis survive beyond five years. However, current therapies including BRAF/MEK targeted therapies or immunotherapies only benefit a subset of melanoma patients due to the emergence of intrinsic or extrinsic resistance mechanisms. Effective treatment of melanoma will thus require new and more effective therapeutic agents. Towards the goal of identifying new therapeutic agents, we conducted an unbiased, druggable epigenetic drug screen using a library of 32 epigenetic inhibitors obtained from the Structural Genome Consortium that targets proteins encoding for epigenetic regulators. This chemical genetic screening identified TP-472, which targets bromodomain-7/9, as the strongest inhibitor of melanoma growth in both short- and long-term survival assays and in mouse models of melanoma tumor growth. Mechanistically, using a transcriptome-wide mRNA sequencing profile we identified TP-472 treatment downregulates genes encoding various extracellular matrix (ECM) proteins, including integrins, collagens, and fibronectins. Reactome-based functional pathway analyses revealed that many of the ECM proteins are involved in extracellular matrix interactions required for cancer cell growth and proliferation. TP-472 treatment also upregulated several pro-apoptotic genes that can inhibit melanoma growth. Collectively, our results identify BRD7/9 inhibitor TP-472 as a potentially useful therapeutic agent for melanoma therapy.

Influence of a B16/F10 melanoma variant on the Вcl-2 levels in mitochondria in various organs of female mice

Aim. To study the Bcl-2 level in mitochondria of various organs in female mice with standard and stimulated growth of an experimental B16/F10 melanoma.Materials and methods. The study included С57ВL/6 female mice (n = 168). The experimental animals were divided into the following groups: an intact group (n = 21), a group with modelled chronic neuropathic pain (CNP) (n = 21), an M group with B16/F10 melanoma (n = 63), and a CNP + M group (n = 63). The Bcl-2 concentration (ng / mg protein) in mitochondrial samples was determined by ELISA (Thermo Fisher Scientific, Austria). Statistical analysis of the results was carried out using Statistica 10.0.Results. Compared to the Bcl-2 levels in the intact animals, CNP decreased this parameter in the cardiac mitochondria by 1.3 times, while increasing it by 5.9 times in the skin mitochondria. In the dynamics of standard melanoma growth, the Bcl-2 content changed compared with the corresponding intact values in the mitochondria of the brain, heart, and skin, but did not change in the liver and kidneys. In the mitochondria in melanoma, the Bcl-2 levels were high throughout the entire period of standard tumor growth in comparison with the intact skin. The stimulated melanoma growth in CNP was involving more organs into the pathological process as the tumor was growing. Thus, in comparison with the values in the CNP group, the mitochondrial Bcl-2 levels changed in the heart at week 1; in the heart and skin – at week 2; in the heart, skin, and brain – at week 3. The Bcl-2 levels did not change in the liver and kidney mitochondria. In the mitochondria in the CNP-stimulated melanoma, the Bcl-2 levels were lower than in the skin mitochondria in CNP throughout the entire tumor growth period.Conclusion. The liver and kidney mitochondria are somewhat Bcl-2 stable in both standard and stimulated tumor growth. It is assumed that different Bcl-2 dynamics in the mitochondria in melanoma depending on the variant of tumor development reflects the modulating effect of CNP and the ability to change the Bcl-2 levels according to the growth phase.