Identification of Galectin-1 as a Critical Factor in Function of Mouse Mesenchymal Stromal Cell-Mediated Tumor Promotion

Bone marrow derived mesenchymal stromal cells (MSCs) have recently been implicated as one source of the tumor-associated stroma, which plays essential role in regulating tumor progression. In spite of the intensive research, the individual factors in MSCs controlling tumor progression have not been adequately defined. In the present study we have examined the role of galectin-1 (Gal-1), a protein highly expressed in tumors with poor prognosis, in MSCs in the course of tumor development. Co-transplantation of wild type MSCs with 4T1 mouse breast carcinoma cells enhances the incidence of palpable tumors, growth, vascularization and metastasis. It also reduces survival compared to animals treated with tumor cells alone or in combination with Gal-1 knockout MSCs. In vitro studies show that the absence of Gal-1 in MSCs does not affect the number of migrating MSCs toward the tumor cells, which is supported by the in vivo migration of intravenously injected MSCs into the tumor. Moreover, differentiation of endothelial cells into blood vessel-like structures strongly depends on the expression of Gal-1 in MSCs. Vital role of Gal-1 in MSCs has been further verified in Gal-1 knockout mice. By administering B16F10 melanoma cells into Gal-1 deficient animals, tumor growth is highly reduced compared to wild type animals. Nevertheless, co-injection of wild type but not Gal-1 deficient MSCs results in dramatic tumor growth and development. These results confirm that galectin-1 is one of the critical factors in MSCs regulating tumor progression

Care of patients with inborn errors of immunity in thirty J Project countries between 2004 and 2021

IntroductionThe J Project (JP) physician education and clinical research collaboration program was started in 2004 and includes by now 32 countries mostly in Eastern and Central Europe (ECE). Until the end of 2021, 344 inborn errors of immunity (IEI)-focused meetings were organized by the JP to raise awareness and facilitate the diagnosis and treatment of patients with IEI.ResultsIn this study, meeting profiles and major diagnostic and treatment parameters were studied. JP center leaders reported patients’ data from 30 countries representing a total population of 506 567 565. Two countries reported patients from JP centers (Konya, Turkey and Cairo University, Egypt). Diagnostic criteria were based on the 2020 update of classification by the IUIS Expert Committee on IEI. The number of JP meetings increased from 6 per year in 2004 and 2005 to 44 and 63 in 2020 and 2021, respectively. The cumulative number of meetings per country varied from 1 to 59 in various countries reflecting partly but not entirely the population of the respective countries. Altogether, 24,879 patients were reported giving an average prevalence of 4.9. Most of the patients had predominantly antibody deficiency (46,32%) followed by patients with combined immunodeficiencies (14.3%). The percentages of patients with bone marrow failure and phenocopies of IEI were less than 1 each. The number of patients was remarkably higher that those reported to the ESID Registry in 13 countries. Immunoglobulin (IgG) substitution was provided to 7,572 patients (5,693 intravenously) and 1,480 patients received hematopoietic stem cell therapy (HSCT). Searching for basic diagnostic parameters revealed the availability of immunochemistry and flow cytometry in 27 and 28 countries, respectively, and targeted gene sequencing and new generation sequencing was available in 21 and 18 countries. The number of IEI centers and experts in the field were 260 and 690, respectively. We found high correlation between the number of IEI centers and patients treated with intravenous IgG (IVIG) (correlation coefficient, cc, 0,916) and with those who were treated with HSCT (cc, 0,905). Similar correlation was found when the number of experts was compared with those treated with HSCT. However, the number of patients treated with subcutaneous Ig (SCIG) only slightly correlated with the number of experts (cc, 0,489) and no correlation was found between the number of centers and patients on SCIG (cc, 0,174).Conclusions1) this is the first study describing major diagnostic and treatment parameters of IEI care in countries of the JP; 2) the data suggest that the JP had tremendous impact on the development of IEI care in ECE; 3) our data help to define major future targets of JP activity in various countries; 4) we suggest that the number of IEI centers and IEI experts closely correlate to the most important treatment parameters; 5) we propose that specialist education among medical professionals plays pivotal role in increasing levels of diagnostics and adequate care of this vulnerable and still highly neglected patient population; 6) this study also provides the basis for further analysis of more specific aspects of IEI care including genetic diagnostics, disease specific prevalence, newborn screening and professional collaboration in JP countries

Identification of Galectin-1 as a Critical Factor in Function of Mouse Mesenchymal Stromal Cell-Mediated Tumor Promotion

<div><p>Bone marrow derived mesenchymal stromal cells (MSCs) have recently been implicated as one source of the tumor-associated stroma, which plays essential role in regulating tumor progression. In spite of the intensive research, the individual factors in MSCs controlling tumor progression have not been adequately defined. In the present study we have examined the role of galectin-1 (Gal-1), a protein highly expressed in tumors with poor prognosis, in MSCs in the course of tumor development. Co-transplantation of wild type MSCs with 4T1 mouse breast carcinoma cells enhances the incidence of palpable tumors, growth, vascularization and metastasis. It also reduces survival compared to animals treated with tumor cells alone or in combination with Gal-1 knockout MSCs. <em>In vitro</em> studies show that the absence of Gal-1 in MSCs does not affect the number of migrating MSCs toward the tumor cells, which is supported by the <em>in vivo</em> migration of intravenously injected MSCs into the tumor. Moreover, differentiation of endothelial cells into blood vessel-like structures strongly depends on the expression of Gal-1 in MSCs. Vital role of Gal-1 in MSCs has been further verified in Gal-1 knockout mice. By administering B16F10 melanoma cells into Gal-1 deficient animals, tumor growth is highly reduced compared to wild type animals. Nevertheless, co-injection of wild type but not Gal-1 deficient MSCs results in dramatic tumor growth and development.</p> <p>These results confirm that galectin-1 is one of the critical factors in MSCs regulating tumor progression.</p> </div

Tumor promoting activity of MSCs depends on the number of MSCs and ratio of MSCs/tumor cells injected.

<p>Different numbers of 4T1 breast carcinoma cells (A: 10⁵; B and D: 10⁴; C:10³) were injected with or without 10⁵ (A–C) or 10⁴ (D) MSCs into Balb/C female mice and tumor size was regularly measured with a special caliper. n = 5.</p

Deficiency of Gal-1 in knockout MSCs diminishes the tumor promoting effect of MSCs.

<p>Female Balb/C mice were challenged by orthotopic inoculation of 10³ 4T1 cells alone or in combination with 10⁵ wtMSCs or MSC^Gal-1−/− (A) or scMSCs or siMSCs (B). C) Tumor bearing (initiated by injection of 10⁵ 4T1 cells) mice were injected intravenously once with 10⁶ (open circles) or twice with 3×10⁵ (black circles) wtMSCs or MSCGal^-1−/−. Tumor size (A left panel) was monitored daily or on the 40^th (B left panel) or 20^th day (C) after tumor initiation. Tumor mass was determined by measuring the formaldehyde fixed primary tumors isolated from sacrificed mice (A and B, right panels). Control mice were injected with PBS or MSCs without tumor cells. Data represent the mean ± SD. Significance on A left graph was calculated only for data on day 38. Number of animals in the experimental groups: A left panel: n = 5, A right panel: n = 5, B left panel: n = 6, B right panel: n = 5, C n = 5–6. ** p<0.01, *** p<0.001. D) Tumor incidence of mice challenged with 10³ 4T1 cells alone or in the combination with 10⁵ wtMSCs or MSC^Gal-1−/− was evaluated using Kaplan-Meier analysis. Control mice were injected with PBS, wtMSC or MSC^Gal-1−/−. Mice were considered as tumor bearing when the tumor was palpable. Tumor free animals were surveyed up to 110 days. n = 5.</p

MSC-derived Gal-1 promotes tumor metastasis.

<p>Lungs were isolated from mice treated as described under Fig. 3. and fixed with formaldehyde. The lungs were weighed (A upper panel) and the metastatic nodules (marked with black arrows) were counted (A lower panel). * p<0.05, ** p<0.01, n = 5. Control mice were injected with either PBS, wtMSC or MSC^Gal-1−/−. (B) Micro-metastases were evaluated on paraffin-embedded, haematoxylin-eosin-stained lung sections. Metastases (m) are delineated by black arrows. Percentage of lung metastatic area (lower graph) was determined as described in <i>Materials and methods</i>. Scale bar: 1 mm.</p

Galectin-1 expression in MSCs does not affect their localization within the tumor.

<p>(A) Migration of CM-DiI labelled wtMSCs and MSC^Gal-1−/− (red) toward 4T1 tumor cells i<i>n vitro</i> was followed for 16 h in Ibidi dish. All nuclei were visualized with Hoechst33342 (blue), and images were taken with fluorescent microscope. MSCs migrating to the cell free zone were counted and the average of 3 independent experiments was presented on the diagram (right panel). (B) Female Balb/C mice were challenged by 4T1 cells alone (10³ cells) (left) or in combination with 10⁵ wtMSC (middle) or MSC^Gal-1−/− (right) pre-labeled with CM/DiI (red). Cryosections of primary tumors were counter-stained with DAPI (blue) and analyzed with a confocal microscope. Representative images of 60 sections obtained from 3 independent experiments are shown. Scale bar: 30 µm.</p