Do tumor exosome integrins alone determine organotropic metastasis?

Metastasis is the most life-threatening event in cancer patients, so the key strategy to treat cancer should be preventing tumor spread. Predicting the site of probable hematogenous metastasis is important for determining the therapeutic algorithm that could prevent the spread of tumor cells. Certain hopes for solving this problem appeared owing to study showing the association between specific integrins on tumor exosomes surface and the site of future metastasis. Numerous experimental data indicate the ability of exosomes to transfer various phlogogenic factors to the target organ, which can lead to the formation of inflammatory foci. Studies of T-lymphocytes homing show that expression of various adhesion molecules including ligands for integrins highly increases on the endothelium during inflammation. Such a mechanism underlies not only in leukocyte transvasation, but, apparently, in the accumulation of bone marrow precursor cells and the formation of a premetastatic niche. This review summarizes the most significant data on the role exosomes to induce inflammation, which leads to the recruiting of bone marrow precursors and the establishment of premetastatic niches.

Responses of Blood System to Doxorubicin/Docetaxel Chemotherapy in Patients with Breast Cancer.

We studied the effects of combined chemotherapy with doxorubicin/docetaxel on erythroid and granulocytic hematopoietic lineages with particular attention focused on their recovery in patients with stages III-IV breast cancer. Intensification of differentiation of erythroid and granulocytic CFU (even under conditions of their suppressed proliferation) provided the increase in the content of mature and morphologically differentiated elements in the bone marrow and peripheral blood. High proliferative activity of erythroid and granulomonocytic precursors resulted from enhanced production of hematopoiesis-stimulating activities by microenvironment elements.

Mechanisms of Granulocytopoiesis Recovery Stimulation with Filgrastim in Breast Cancer Patients Receiving Chemotherapy.

We studied myelotoxicity of modern schemes of chemotherapy for breast cancer (docetaxel/doxorubicin and cyclophosphamide/doxorubicin/5-fluorouracil) towards granulocytopoiesis, the mechanisms determining the differences of hematological effects of these schemes, and the efficiency of correction of the observed changes with granulocyte CSF (filgrastim). Granulocytopoiesis stimulation with filgrastim during the treatment with docetaxel/doxorubicin combination was more pronounced than during cyclophosphamide/doxorubicin/5-fluorouracil therapy. The observed differences were found at all levels of granulocyte lineage organization (central and peripheral), which is related to different effects of the cytostatic substances used in the proposed protocols on the structures controlling hemopoiesis.

Assessment of Erythroid and Granulocytic Hematopoietic Lineages in Patients with Non-Small-Cell Lung Carcinoma.

The toxic effects of combined cisplatin/docetaxel therapy cycles on erythroid and granulocytic hematopoietic lineages as well as their intercycle recovery were examined in patients with stage III-IV non-small-cell lung carcinoma. Responsiveness of the blood system to this therapy remained at a high level. Combined therapy pronouncedly activated the key elements of the erythroid and granulocytic hematopoietic lineages leading to accumulation of immature and mature myelokaryocytes in the bone marrow, enlargement of the medullary pool of mature neutrophils, and increase in the count of medullary erythroid and granulocytic precursor cells under conditions of their accelerated maturation.

Internalization of extracellular vesicles of cancer patients by peripheral blood mononuclear cells during polychemotherapy: connection with neurotoxicity.

Extracellular vesicles (EVs), exhibiting their functional activity after internalization by recipient cells, are involved in the pathogenesis of drug-induced polyneuropathy (DIPN), a common complication of antitumor therapy. In this work, the internalization of EVs obtained from colorectal cancer patients undergoing polychemotherapy and its relationship with neurotoxicity were assessed using a model system of mononuclear leukocytes. Circulating EVs were isolated from 8 colorectal cancer patients who received antitumor therapy according to the FOLFOX or XELOX regimens before the start of chemotherapy (point 1) and after 3-4 courses (point 2). Mononuclear leukocytes of a healthy donor served as a cellular model system for EV internalization in vitro. EV internalization was assessed using fluorescence microscopy. It was shown that internalization of EVs obtained from colorectal cancer patients with high neurotoxicity was higher than in the group with low neurotoxicity. The ability of CD11b-positive (CD11b⁺) and CD11b-negative (CD11b⁻) mononuclear leukocytes of a healthy donor to internalize EVs obtained from patients before and after chemotherapy did not reveal significant differences. A direct relationship was found between the relative number of CD11b⁻ cells with internalized EVs and the integral index of neurotoxicity according to the NRS scale at the peak of its manifestation (point 2) (r=0.675, p.

Reactions of granulocytic lineage of hemopoiesis and mechanisms of their development in combined treatment with adriablastin and taxotere.

We studied myelotoxic effects of adriablastin and taxotere combination on granulocytic lineage cells and processes of their recovery in patients with stage III-IV breast cancer. Intensive maturation of granulocytic CFU provided regeneration of the hemopoiesis even under conditions of reduced proliferative activity of these cells, which, in turn, led to accumulation of mature and immature neutrophilic granulocytes in the bone marrow and improved reserve capacities of the neutrophil pool in the bone marrow.

[Hemostimulating properties of cropanol during cytostatics-induced myelosuppression]. / Gemostimuliruiushchie svoistva kropanola pri tsitostaticheskoi mielosupressii.

The granulocyte lineage reaction and its mechanism were studied in the bone marrow of patients with breast cancer in stage III-IV treated according to a specific CAF scheme including cropanol, an antitumor drug of the animal origin. It was found that the bone marrow cytopoiesis suppressed by the cytostatics is stimulated by cropanol on the level of committed precursors, morphologically differentiated bone marrow elements, and peripheral blood.

Mechanisms of stimulation of granulocytopoiesis with neupogen in patients with breast cancer during chemotherapy.

The mechanisms of granulocytopoiesis stimulation with granulocytic CSF (neupogen), added to chemotherapy protocol (adriablastine+taxotere) in patients with stages III-IV breast cancer, were studied. The hemostimulatory effect of granulocytic CSF preparation is based on stimulation of proliferation and differentiation of granulomonocytopoisis precursor cell in the hemopoietic tissue, due to neupogen effects on hemopoietic elements and on the hemopoiesis-inducing microenvironment cells.

Effect of granulocyte colony-stimulating factor on kinetics of hemopoietic precursors in regenerating bone marrow.

We studied processes of proliferation and differentiation of hemopoietic precursor cells in mice treated with granulocyte CSF under conditions of cytostatic myelodepression. It was found that the hemostimulating effect of original granulocyte CSF preparation consists in accelerated maturation of hemopoietic precursors and increased content of DNA-synthesizing CFU-GM in the bone marrow.

Compensatory reactions during impairment of granulocytic stem in patients with lung cancer receiving antitumor chemotherapy.

We compared changes in the granulocytic hemopoietic stem in patients with stage III-IV lung cancer receiving cytostatic therapy by the original CVC and standard CAM schemes. In patients treated with the CVC regimen, the granulocytic hemopoietic stem possessed more potent compensatory capacities.

Mechanisms of myelopoiesis stimulation with pantohematogen and granulocyte colony-stimulating factor during cytostatic myelosuppression.

We compared hemopoiesis-stimulating activities of dry pantohematogen and recombinant granulocyte colony-stimulating factor under conditions of cyclophosphamide-induced myelosuppression. These preparations stimulated regeneration of bone marrow granulomonocytopoiesis by various mechanisms.