Locally advanced mid/low rectal cancer with synchronous resectable liver metastases: systematic review of the available strategies and outcome

The management of patients with locally advanced mid/low rectal cancer with resectable liver metastases is complex because of the need to combine the optimal treatment of both tumors. This study aims to review the available treatment strategies and compare their outcome, focusing on radiotherapy (RT) and liver-first approach (LFA). A systematic review was performed in PubMed, Embase, and web sources including articles published between 2000 and 02/2023 and reporting mid-/long-term outcomes. Overall, twenty studies were included (n = 1837 patients). Three- and 5-year overall survival (OS) rates were 51-88% and 36-59%. Although several strategies were reported, most patients received RT (1448/1837, 79%; > 85% neoadjuvant). RT reduced the pelvic recurrence risk (5.8 vs. 13.5%, P = 0.005) but did not impact OS. Six studies analyzed LFA (n = 307 patients). LFA had a completion rate similar to the rectum-first approach (RFA, 81% vs. 79%) but the interval strategy-an LFA variant with liver surgery in the interval between radiotherapy and rectal surgery-had a better completion rate than standard LFA (liver surgery/radiotherapy/rectal surgery, 92% vs. 75%, P = 0.011) and RFA (79%, P = 0.048). Across all series, LFA achieved the best survival rates, and in one paper it led to a survival advantage in patients with multiple metastases. In conclusion, different strategies can be adopted, but RT should be included to decrease the pelvic recurrence risk. LFA should be considered, especially in patients with high hepatic tumor burden, and RT before liver surgery (interval strategy) could maximize its completion rate.

The Functional Assessment of Cancer Therapy Scale: Development and Validation of the General Measure

PURPOSE

We developed and validated a brief, yet sensitive, 33-item general cancer quality-of-life (QL) measure for evaluating patients receiving cancer treatment, called the Functional Assessment of Cancer Therapy (FACT) scale.

METHODS AND RESULTS

The five-phase validation process involved 854 patients with cancer and 15 oncology specialists. The initial pool of 370 overlapping items for breast, lung, and colorectal cancer was generated by open-ended interview with patients experienced with the symptoms of cancer and oncology professionals. Using preselected criteria, items were reduced to a 38-item general version. Factor and scaling analyses of these 38 items on 545 patients with mixed cancer diagnoses resulted in the 28-item FACT-general (FACT-G, version 2). In addition to a total score, this version produces subscale scores for physical, functional, social, and emotional well-being, as well as satisfaction with the treatment relationship. Coefficients of reliability and validity were uniformly high. The scale's ability to discriminate patients on the basis of stage of disease, performance status rating (PSR), and hospitalization status supports its sensitivity. It has also demonstrated sensitivity to change over time. Finally, the validity of measuring separate areas, or dimensions, of QL was supported by the differential responsiveness of subscales when applied to groups known to differ along the dimensions of physical, functional, social, and emotional well-being.

CONCLUSION

The FACT-G meets or exceeds all requirements for use in oncology clinical trials, including ease of administration, brevity, reliability, validity, and responsiveness to clinical change. Selecting it for a clinical trial adds the capability to assess the relative weight of various aspects of QL from the patient's perspective.

Long COVID-19 syndrome: association of cardiopulmonary impairment with a persistent platelet activation

Background

A considerable proportion of patients do not fully recover from COVID-19 infection and report symptoms that persist beyond the initial phase of infection: this condition is defined long-COVID-19 syndrome (LCS). LCS can involve lungs as well as several extrapulmonary organs, including the cardiovascular system. The risk and 1-year burden of cardiovascular diseases (CVD) is increased in COVID-19 survivors, even in subjects at low risk of CVD. Recently, we documented that acute COVID-19 infection induces altered platelet activation state characterized by a prothrombotic phenotype and by the formation of platelet-leukocyte aggregates (PLA), that may be involved in the pulmonary microthrombi found in autoptic specimens. No data are yet available on the contribution of platelet activation to residual pulmonary impairment and procoagulant potential in LCS patients.

Purpose

To study platelet activation status, microvesicle (MV) profile, platelet thrombin generation capacity (pTGC) in LCS patients enrolled at 6 months after resolution of the acute phase (6mo-FU), compared to acute COVID-19 infection patients.

Methods

6mo-FU COVID-19 patients (n=24) with established LCS were enrolled at Centro Cardiologico Monzino. Residual pulmonary impairment was assessed by Cardiopulmonary Exercise Testing (CPET) and 64-rows-CT scan evaluation. Platelet activation (P-selectin, Tissue Factor [TF] and PLA) and MV profile were assessed by flow cytometry; pTGC by calibrated automated thrombogram. 46 patients enrolled during acute COVID-19 infection and 46 healthy subjects (HS) were used for comparison.

Results

Dispnea in LCS patients was confirmed by CPET showing compromised alveolus-capillary membrane diffusion and residual pulmonary impairment. TF+-platelet and -MV levels were 3-fold (1.5% [1.2–2.9] vs 2.4% [1.6–5.7]) and 2-fold (217/μl [137–275] vs 435/μl [275–633]) lower at 6mo-FU compared to acute phase, being comparable to HS. pTGC behaved similarly. At 6mo-FU, the MV profile, in terms of total number and cell origin, returned to physiological levels. Conversely, although lower than that measured in acute phase, a 2.5-fold higher platelet P-selectin expression (6.9% [3–13.5] vs 11.7% [5.2–18.9]) and PLA formation (35.5% [27.4–46.8] vs 67.7% [45.7–85.3]) was observed at 6mo-FU compared to HS. Interestingly, a significant correlation between PLA formation and residual pulmonary impairment was observed (r=−0.423; p=0.02).

Conclusion

These data strengthen the hypothesis that the presence of PLA in the bloodstream, and thus also in the pulmonary microcirculation, may contribute to support pulmonary dysfunction still observed in LCS patients.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Italian Ministry of Health (Ricerca Corrente 2020 MPP COVID4)

Role of impaired iron transport on exercise performance in heart failure patients

Aims

Impaired iron transport (IIT) occurs frequently in heart failure (HF) patients, even in the absence of anaemia and it is associated with a poor quality of life and prognosis. The impact of IIT on exercise capacity, as assessed by the cardiopulmonary exercise test (CPET), in HF is at present unknown. The aim of this article is to evaluate in HF patients the impact on exercise performance of IIT, defined as transferrin saturation (TSAT) <20%.

Methods and results

We collected data of 676 patients hospitalised for HF. All underwent laboratory analysis, cardiac ultrasound, and CPET. Patients were grouped by the presence/absence of IIT and anaemia (haemoglobin <13 and <12 g/dL in male and female, respectively): Group 1 (G1) no anaemia, no IIT; Group 2 (G2) anaemia, no IIT; Group 3 (G3) no anaemia, IIT; Group 4 (G4) anaemia and IIT. Peak oxygen uptake (peakVO2) reduced from G1 to G3 and from G2 to G4 (G1: 1266±497 mL/min, G2: 1011±385 mL/min, G3: 1041±395 mL/min, G4: 833±241 mL/min), whereas the ventilation to carbon dioxide relationship slope (VE/VCO2 slope) increased (G1: 31.8±7.5, G2: 34.5±7.4, G3: 36.1±10.2, G4: 37.5±8.4). At multivariate regression analysis, peakVO2 independent predictors were anaemia, brain natriuretic peptide (BNP), and left ventricular ejection fraction, whereas VE/VCO2 slope independent predictors were IIT and BNP.

Conclusions

In HF IIT is associated with exercise performance impairment independently from anaemia, and it is a predictor of elevated VE/VCO2 slope, a pivotal index of HF prognosis.

Funding Acknowledgement

Type of funding sources: Private hospital(s). Main funding source(s): Centro cardiologico Monzino, Italy

Impact of chronic GLP-1 receptor agonist and SGLT-2 inhibitor therapy on in-hospital outcomes of patients with diabetes mellitus hospitalized with acute myocardial infarction

Background

Glucagon-like peptide-1 receptor agonists (GLP-1 RA) and sodium glucose cotransporter-2 inhibitors (SGLT-2i) demonstrated cardiovascular and renal protection in addition to their glucose-lowering effect. Whether their benefits occur also in patients with diabetes mellitus (DM) during hospitalisation with acute myocardial infarction (AMI) has not been investigated yet.

Purpose

We evaluated in-hospital outcomes of patients hospitalised with AMI according to their chronic use (before hospitalisation) of GLP-1 RA and SGLT-2i therapy.

Methods

Using administrative healthcare databases, we analysed patients hospitalised with a primary diagnosis of AMI from 2010 to 2019 in the Lombardy region, Italy. Patients were stratified according to their DM status, then divided into three cohorts: Group 1 (non-DM patients); Group 2 (DM patients taking GLP-1 RA or SGLT-2i); and Group 3 (DM patients not taking GLP-1 RA and/or SGLT-2i). Patients were matched in a 1:1:1 ratio using a propensity score including all available variables. The primary endpoint of the study was the composite of in-hospital mortality, acute heart failure, and acute kidney injury requiring renal replacement therapy.

Results

We identified 146,800 patients hospitalised with AMI (26% of them with DM). After propensity score matching, 1,030 patients were included in each group. The primary endpoint rate in the overall population was 16% (n=502) and it significantly increased going from Group 1 to Group 3 (13%, 16%, and 20% respectively; p for trend <0.0001). The risk of the composite endpoint significantly increased from Group 1 to Group 3 (P for trend <0.0001). In comparison with Group 2, Group 3 had a significant higher risk of the composite endpoint (OR 1.40 [95% CI 1.11–1.77]).

Conclusions

Our study shows that DM patients hospitalised with AMI and on chronic GLP-1 RA and/or SGLT-2i therapy have a better in-hospital clinical outcome than DM patients without them.

Funding Acknowledgement

Type of funding sources: None.

A new prediction model for left ventricular systolic function recovery after catheter ablation of atrial fibrillation in patients with heart failure and reduced ejection fraction, The ANTWOORD Study

Funding Acknowledgements

Type of funding sources: None.

Background

In patients with heart failure with reduced ejection fraction (HFrEF) and atrial fibrillation (AF), pulmonary vein isolation (PVI) improves left ventricular ejection fraction (LVEF), along with prognosis, in a variable percentage of patients.

Aim

To investigate the predictors of LVEF recovery after PVI and to develop a prediction model for individualized assessment.

Methods

We conducted an observational, retrospective, single-center study on 111 consecutive patients with AF and HFrEF undergoing PVI. Patients were divided into Responder vs. Non-Responder according to the "Universal definition of HF". Clinical predictors were evaluated by multivariate logistic regression analysis and cross-validation technique. Independent predictors were used to build an internally validated prediction model.

Results Responders (54%) had significantly shorter QRS duration and less dilated left atria. Persistent AF and absence of a known etiology more frequent among Responders. AF recurrence was non-significantly different between the two groups (p=0.2), although clinical AF burden was lower in Responders, after PVI (p<0.001). Absence of known etiology, presence of persistent AF, left atrial volume index<50ml/m2, and QRS<120msec were independent predictors of LVEF recovery and composed the "Antwerp Score". Patients with Antwerp Score ≤1 had 90% likelihood of LVEF recovery, compared to 5% in patients with 3-6.

Conclusions Patients with wide QRS complex, known HF etiology, dilated left atria, and paroxysmal AF were less likely to recover LVEF after PVI. A new score system based on the above-mentioned parameters adequately predict LV function recovery after PVI. These results warrant confirmation and prospective validation.

P244 BRISK WALKING CAN BE A MAXIMAL EFFORT IN HEART FAILURE PATIENTS. A COMPARISON OF CARDIOPULMONARY EXERCISE AND SIX–MINUTE WALKING TEST CARDIORESPIRATORY DATA

Aims

Cardiopulmonary exercise test (CPET) and six–minute walking test (6MWT) are frequently used in heart failure (HF). CPET is a maximal exercise, whereas 6MWT is a self–selected constant load test usually considered a submaximal, and therefore safer, exercise but this has not been tested previously. The aim of this study was to compare the cardiorespiratory parameters collected during CPET and 6MWT in a large group of healthy subjects and patients with HF of different severity.

Methods and Results

Subjects performed a standard maximal CPET and a 6MWT wearing a portable device allowing breath–by–breath measurement of cardiorespiratory parameters. HF Patients were grouped according to their CPET peak oxygen uptake (peakV̇O2). One–hundred and fifty–five subjects were enrolled, of whom 40 were healthy (59±8 years; male 67%) and 115 were HF patients (69±10 years; male 80%; left ventricular ejection fraction 34.6±12.0%). CPET peakV̇O2 was 13.5±3.5 ml/kg/min in HF patients and 28.1±7.4 ml/kg/min in healthy (p < 0.001). 6MWT–V̇O2 was 98±20% of the CPET peakV̇O2 values in HF patients, while 72±20% in healthy subjects (p < 0.001). 6MWT–V̇O2 was >110% of CPET peakV̇O2 in 42% of more severe HF patients (peakV̇O2<12ml/kg/min). Similar results have been found for ventilation and heart rate. Of note, the slope of the relationship between V̇O2 at 6MWT, reported as percentage of CPET peakV̇O2 vs. 6MWT V̇O2 reported as absolute value, progressively increased as exercise limitation did.

Conclusions

6MWT must be perceived as a maximal or even supra–maximal exercise activity at least in patients with severe exercise limitation from HF. Our findings should influence the safety procedures needed for the 6MWT in HF.

ROLE OF CARDIOPULMONARY EXERCISE TEST IN THE PREDICTION OF HEMODYNAMIC IMPAIRMENT IN PATIENTS WITH PULMONARY ARTERIAL HYPERTENSION

Periodic repetition of right heart catheterization (RHC) in pulmonary arterial hypertension (PAH) can be challenging. We evaluated the correlation between RHC and cardiopulmonary exercise test (CPET) aiming at CPET use as a potential noninvasive tool for hemodynamic burden evaluation. One hundred and forty‐four retrospective PAH patients who had performed CPET and RHC within 2 months were enrolled. The following analyses were performed: (a) CPET parameters in hemodynamic variables tertiles; (b) position of hemodynamic parameters in the peak end‐tidal carbon dioxide pressure (P_ETCO₂) versus ventilation/carbon dioxide output (VE/VCO₂) slope scatterplot, which is a specific hallmark of exercise respiratory abnormalities in PAH; (c) association between CPET and a hemodynamic burden score developed including mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance (PVR), cardiac index, and right atrial pressure. VE/VCO₂ slope and peak P_ETCO₂ significantly varied in mPAP and PVR tertiles, while peak oxygen uptake (peak VO₂) and O₂ pulse varied in the tertiles of all hemodynamic parameters. P_ETCO₂ versus VE/VCO₂ slope showed a strong hyperbolic relationship (R² = 0.7627). Patients with peak P_ETCO₂ > median (26 mmHg) and VE/VCO₂ slope < median (44) presented lower mPAP and PVR (p < 0.005) than patients with peak P_ETCO₂ < median and VE/VCO₂ slope > median. Multivariate analysis individuated peak VO₂ (p = 0.0158) and peak P_ETCO₂ (p = 0.0089) as hemodynamic score independent predictors; the formula 11.584 − 0.0925 × peak VO₂ − 0.0811 × peak P_ETCO₂ best predicts the hemodynamic score value from CPET data. A significant correlation was found between estimated and calculated scores (p < 0.0001), with a precise match for patients with mild‐to‐moderate hemodynamic burden (76% of cases). The results of the present study suggest that CPET could allow to estimate the hemodynamic burden in PAH patients.

Paclitaxel Priming of TRAIL Expressing Mesenchymal Stromal Cells (MSCs-TRAIL) Increases Antitumor Efficacy of Their Secretome

BACKGROUND

Adipose tissue derived MSCs engineered with the tumor necrosis factor-related apoptosis-inducing ligand protein (MSCs-TRAIL) have a significant anticancer activity. MSCs, without any genetic modifications, exposed to high doses of chemotherapeutic agents are able to uptake the drug and release it in amount affecting tumor proliferation. The purpose of this study was to verify the ability of MSCs-TRAIL to uptake and release paclitaxel (PTX) by providing an increased antitumor efficacy.

METHODS

MSCs and MSCs-TRAIL were tested for their sensitivity to Paclitaxel (PTX) by MTT assay and the cells were loaded with PTX according to a standardized procedure. The secretome was analysed by HPLC for the presence of PTX, microarray assay for soluble TRAIL (s-TRAIL) and tested for in vitro anticancer activity.

RESULTS

MSCs-TRAIL were resistant to PTX and able to incorporate and then release the drug. The secretion of s-TRAIL by PTX loaded MSCs-TRAIL was not inhibited and the PTX delivery together with s-TRAIL secretion resulted into an increased antitumor efficacy of cell secretoma as tested in vitro on human pancreatic carcinoma (CFPAC-1) and glioblastoma (U87-MG).

CONCLUSIONS

Our result is the first demonstration of the possible merging of two new MSCs therapy approaches based on genetic manipulation and drug delivery. If confirmed in vivo, this could potentiate the efficacy of MSCs-TRAIL and strongly contribute to reduce the toxicity due to the systemic treatment of PTX.

Atrial fibrillation ablation in athletes: 5-years experience of a single italian third-level center

Background

The number of master athletes is increasing and treatment of AF is mandatory for sports continuation. However, few data exist about the effectiveness of catheter ablation (CA) in athletes and the feasibility of resuming vigorous exercise afterwards.

Objectives

Aim of our study was to analyze the efficacy and safety of AF CA in athletes and to evaluate the feasibility of resuming vigorous exercise.

Methods

We report a retrospective registry of athletes referred to our center for AF CA in the last five years. All athletes were previously declared non-eligible to competitive sport because of recurrences of AF or evidence of persistent asymptomatic AF. CA was performed as per practice and recurrences were defined as recrudescence of symptoms and/or any documentation of AF lasting more than 30 sec. At the end of the follow-up all pts were asked about resuming sport.

Results

We ablated 40 athletes (38 males, 95%) with a mean age of 48±13 years. Mean left atrium volume was 36±11 ml/m2 and mean ejection fraction was 61±5%. Distribution between AF characteristics was: 31 (78%) paroxysmal AF, 8 (20%) early-persistent AF, 1 (2%) long-persistent AF.

After a median follow-up of 787 days, 62,5% of athletes were free from recurrences after one CA procedure and mostly without antiarrhythmic drugs (87%). 7 athletes underwent a redo procedure and all of them were then free of recurrences with an overall freedom from recurrences of 84%. No major complication was observed. Athletes practicing endurance sports showed a negative trend in terms of recurrences (p = ns).

Most (72%) of the athletes resumed vigorous exercise after at least 3 months from the CA as per Italian sport protocols.

Conclusions

CA is safe and efficient in treating AF also in athletes. Resuming high intensity sports is often possible after 3 months from CA.

Funding Acknowledgement

Type of funding source: None

Effect of canine mesenchymal stromal cells loaded with paclitaxel on growth of canine glioma and human glioblastoma cell lines

This study investigated whether canine mesenchymal stromal cells (cMSCs) are able to take up and release paclitaxel (PTX) in active form, and therefore whether they have potential as a tool for therapeutic delivery of this drug. cMSCs from bone marrow and adipose tissue were isolated, expanded and characterised phenotypically. cMSCs were loaded with PTX (cMSCs-PTX) and their capacity for release of PTX was determined by their effect on proliferation of cancer cells. cMSCs-PTX derived from bone marrow and adipose tissue were able to take up and then release active PTX. cMSCs-PTC inhibited proliferation of the canine glioma cell line J3T, and the human glioblastoma cell lines T98G and U87MG. The potential of canine cMSCs-PTX for treatment of canine gliomas should be investigated further.

Human mesenchymal stromal cells inhibit tumor growth in orthotopic glioblastoma xenografts

BACKGROUND

Mesenchymal stem/stromal cells (MSCs) represent an attractive tool for cell-based cancer therapy mainly because of their ability to migrate to tumors and to release bioactive molecules. However, the impact of MSCs on tumor growth has not been fully established. We previously demonstrated that murine MSCs show a strong tropism towards glioblastoma (GBM) brain xenografts and that these cells are able to uptake and release the chemotherapeutic drug paclitaxel (PTX), maintaining their tropism towards the tumor. Here, we address the therapy-relevant issue of using MSCs from human donors (hMSCs) for local or systemic administration in orthotopic GBM models, including xenografts of patient-derived glioma stem cells (GSCs).

METHODS

U87MG or GSC1 cells expressing the green fluorescent protein (GFP) were grafted onto the striatum of immunosuppressed rats. Adipose hMSCs (Ad-hMSCs), fluorescently labeled with the mCherry protein, were inoculated adjacent to or into the tumor. In rats bearing U87MG xenografts, systemic injections of Ad-hMSCs or bone marrow (BM)-hMSCs were done via the femoral vein or carotid artery. In each experiment, either PTX-loaded or unloaded hMSCs were used. To characterize the effects of hMSCs on tumor growth, we analyzed survival, tumor volume, tumor cell proliferation, and microvascular density.

RESULTS

Overall, the AD-hMSCs showed remarkable tropism towards the tumor. Intracerebral injection of Ad-hMSCs significantly improved the survival of rats with U87MG xenografts. This effect was associated with a reduction in tumor growth, tumor cell proliferation, and microvascular density. In GSC1 xenografts, intratumoral injection of Ad-hMSCs depleted the tumor cell population and induced migration of resident microglial cells. Overall, PTX loading did not significantly enhance the antitumor potential of hMSCs. Systemically injected Ad- and BM-hMSCs homed to tumor xenografts. The efficiency of hMSC homing ranged between 0.02 and 0.5% of the injected cells, depending both on the route of cell injection and on the source from which the hMSCs were derived. Importantly, systemically injected PTX-loaded hMSCs that homed to the xenograft induced cytotoxic damage to the surrounding tumor cells.

CONCLUSIONS

hMSCs have a therapeutic potential in GBM brain xenografts which is also expressed against the GSC population. In this context, PTX loading of hMSCs seems to play a minor role.

Angiogenic and anti-inflammatory properties of micro-fragmented fat tissue and its derived mesenchymal stromal cells

BACKGROUND

Adipose-derived mesenchymal stromal cells (Ad-MSCs) are a promising tool for advanced cell-based therapies. They are routinely obtained enzymatically from fat lipoaspirate (LP) as SVF, and may undergo prolonged ex vivo expansion, with significant senescence and decline in multipotency. Besides, these techniques have complex regulatory issues, thus incurring in the compelling requirements of GMP guidelines. Hence, availability of a minimally manipulated, autologous adipose tissue would have remarkable biomedical and clinical relevance. For this reason, a new device, named Lipogems® (LG), has been developed. This ready-to-use adipose tissue cell derivate has been shown to have in vivo efficacy upon transplantation for ischemic and inflammatory diseases. To broaden our knowledge, we here investigated the angiogenic and anti-inflammatory properties of LG and its derived MSC (LG-MSCs) population.

METHODS

Human LG samples and their LG-MSCs were analyzed by immunohistochemistry for pericyte, endothelial and mesenchymal stromal cell marker expression. Angiogenesis was investigated testing the conditioned media (CM) of LG (LG-CM) and LG-MSCs (LG-MSCs-CM) on cultured endothelial cells (HUVECs), evaluating proliferation, cord formation, and the expression of the adhesion molecules (AM) VCAM-1 and ICAM-1. The macrophage cell line U937 was used to evaluate the anti-inflammatory properties, such as migration, adhesion on HUVECs, and release of RANTES and MCP-1.

RESULTS

Our results indicate that LG contained a very high number of mesenchymal cells expressing NG2 and CD146 (both pericyte markers) together with an abundant microvascular endothelial cell (mEC) population. Substantially, both LG-CM and LG-MSC-CM increased cord formation, inhibited endothelial ICAM-1 and VCAM-1 expression following TNFα stimulation, and slightly improved HUVEC proliferation. The addition of LG-CM and LG-MSC-CM strongly inhibited U937 migration upon stimulation with the chemokine MCP-1, reduced their adhesion on HUVECs and significantly suppressed the release of RANTES and MCP-1.

CONCLUSIONS

Our data indicate that LG micro-fragmented adipose tissue retains either per se, or in its embedded MSCs content, the capacity to induce vascular stabilization and to inhibit several macrophage functions involved in inflammation.

Paclitaxel-releasing mesenchymal stromal cells inhibit the growth of multiple myeloma cells in a dynamic 3D culture system

Multiple myeloma is an aggressive tumour able to suppress osteoblastogenesis probably mediated by bone marrow mesenchymal stromal cells (BM-MSCs) that can also support plasma cell growth/survival. The use of MSCs for multiple myeloma therapy is a controversial topic because of the contradictory results on the capacity of MSCs to inhibit or to promote cancer growth. Our previous studies demonstrated that MSCs could be loaded with Paclitaxel (PTX) and used to deliver the drug in situ in amount affecting tumour growth (in vitro and in vivo). Therefore, independently on the discussed action of MSCs in myeloma, MSCs could represent a 'trojan horse' to vehicle and deliver anti-tumour agents into bone marrow. This study confirms, by an in vitro 3D dynamic culture system, that PTX loaded BM-MSCs (PTXr-MSCs) are active on the proliferation of RPMI 8226, a human myeloma cell line. Our results demonstrated a dramatic suppression of myeloma cell growth by PTXr-MSCs, suggesting that drug loaded MSCs could be a tool to deliver drug into the bone marrow. Drug releasing MSCs provide a therapeutic approach to potentiate the existing treatments against a very aggressive malignancy as multiple myeloma. Copyright © 2016 John Wiley & Sons, Ltd.

Cell-mediated drug delivery by gingival interdental papilla mesenchymal stromal cells (GinPa-MSCs) loaded with paclitaxel

OBJECTIVE

Gingival tissue is composed of cell types that contribute to the body's defense against many agents in oral environment, wound healing and tissue regeneration. Thanks to their easy and scarcely invasive withdrawal procedure, interdental papilla provide a good source of mesenchymal stromal cells (GinPa-MSCs). We isolated GinPa-MSCs and verified their ability to uptake/release the anticancer agent Paclitaxel (PTX).

METHODS

In vitro expanded GinPa-MSCs were characterized for CD markers by FACS, tested for differentiation ability and analyzed by TEM. Their ability to uptake/release PTX was assessed according to a standardized procedure.

RESULTS

The CD expression and chondro-adipo-osteo differentiation ability confirmed the mesenchymal feature of GinPa-MSCs. Surprisingly, 28% of GinPa-MSCs expressed CD14 marker and had an impressive pinocytotic activity. GinPa-MSCs were able to take up and release a sufficient amount of PTX to demonstrate effective in vitro activity against pancreatic carcinoma cells, suggesting that the drug was not inactivated.

CONCLUSIONS

The procedure to obtain MSCs from interdental papilla is less invasive than that used for both bone marrow and adipose tissue, GinPa-MSCs are easy to expand and can be efficiently loaded with PTX. Taken together these qualities suggest that GinPa-MSCs may prove to be a good tool for cell-mediated drug delivery in cancer, particularly if related to stomatognathic system.

Human skin-derived fibroblasts used as a 'Trojan horse' for drug delivery

BACKGROUND

Drug toxicity currently represents the main challenge of tumour chemotherapy. Our group recently developed a new method for drug delivery inspired by the 'Trojan Horse' concept. Human mesenchymal stem cells (hMSCs) have been shown to play the role of new 'horses' in delivering anti-tumour agents, without involving any genetic manipulation. As human stromal dermal fibroblasts (hSDFs) represent an interesting alternative to hMSCs, being easy to isolate, they could be an ideal candidate for this kind of procedure.

AIM

To investigate whether hSDFs can take up and deliver paclitaxel (PTX) in sufficient concentrations to inhibit a very aggressive melanoma tumour (IgR39) in vitro.

METHODS

hSDFs were primed with high doses of PTX, and then the effect of drug delivery on IgR39 melanoma proliferation in vitro was evaluated using several assays (antiproliferation, transwell cocultures, rosette assays and colony growth assays). Furthermore, the cell cycle and PTX uptake/release mechanism of hSDFs were studied both under both normal and hypoxic conditions.

RESULTS

hSDFs incorporated PTX and then released it with unaffected pharmacological activity, inhibiting human IgR39 melanoma growth in vitro. The hypoxic conditions did not induce changes in cell cycle pattern and the uptake-release mechanism with PTX was not affected.

CONCLUSIONS

hSDFs can be used as a Trojan horse, as the released drug was functionally active. These results indicated that these cells could be used for clinical treatment as the drug was released into the cellular environment and the primed cells underwent apoptosis.

Mesenchymal stromal cells uptake and release paclitaxel without reducing its anticancer activity

To improve the drug delivery efficiency on target cells, many strategies have been developed including Mesenchymal Stromal Cells (MSCs) approaches. In a previous study, we found that bone-marrow-derived MSCs (BM-MSCs) were able to incorporate and release the anti-tumor and anti-angiogenic drug, Paclitaxel (PTX). In this study, we evaluated the stability of PTX in standard cell culture conditions by analyzing the metabolites produced by MSCs after their incorporation of the drug. We are able to show that MSCs do not release either 3-OH-PTX or 6-OH-PTX metabolites (having a lower anticancer activity) but release an active PTX molecule together with the isomer 7-Epitaxol, is known to maintain the whole biological activity. This confirms that the simple procedure of MSCs priming with a drug (without any genetic cell manipulation), in our case PTX, does not modify the activity of the molecule and provides a new biological-device to carry and deliver PTX in tumor sites, by contributing to improve drug efficacy and target selectivity in cancer therapy.

Gemcitabine-releasing mesenchymal stromal cells inhibit in vitro proliferation of human pancreatic carcinoma cells

BACKGROUND AIMS

Pancreatic cancer (pCa) is a tumor characterized by a fibrotic state and associated with a poor prognosis. The observation that mesenchymal stromal cells (MSCs) migrate toward inflammatory micro-environments and engraft into tumor stroma after systemic administration suggested new therapeutic approaches with the use of engineered MSCs to deliver and produce anti-cancer molecules directly within the tumor. Previously, we demonstrated that without any genetic modifications, MSCs are able to deliver anti-cancer drugs. MSCs loaded with paclitaxel by exposure to high concentrations release the drug both in vitro and in vivo, inhibiting tumor proliferation. On the basis of these observations, we evaluated the ability of MSCs (from bone marrow and pancreas) to uptake and release gemcitabine (GCB), a drug widely used in pCa treatment.

METHODS

MSCs were primed by 24-h exposure to 2000 ng/mL of GCB. The anti-tumor potential of primed MSCs was then investigated by in vitro anti-proliferation assays with the use of CFPAC-1, a pancreatic tumor cell line sensitive to GCB. The uptake/release ability was confirmed by means of high-performance liquid chromatography analysis. A cell-cycle study and secretome evaluation were also conducted to better understand the characteristics of primed MSCs.

RESULTS

GCB-releasing MSCs inhibit the growth of a human pCa cell line in vitro.

CONCLUSIONS

The use of MSCs as a "trojan horse" can open the way to a new pCa therapeutic approach; GCB-loaded MSCs that integrate into the tumor mass could deliver much higher concentrations of the drug in situ than can be achieved by intravenous injection.

Mesenchymal stromal cells loaded with paclitaxel induce cytotoxic damage in glioblastoma brain xenografts

INTRODUCTION

The goal of cancer chemotherapy is targeting tumor cells and/or tumor-associated microvessels with the lowest systemic toxicity. Mesenchymal stromal cells (MSCs) are promising vehicles for selective drug delivery due to their peculiar ability to home to pathological tissues. We previously showed that MSCs are able to uptake and subsequently to release the chemotherapeutic compound Paclitaxel (PTX) and to impair the growth of subcutaneous glioblastoma multiforme (GBM) xenografts. Here we used an orthotopic GBM model 1) to assess whether PTX-loaded MSCs (PTX-MSCs) retain a tropism towards the tumor cells in the brain context, and 2) to characterize the cytotoxic damage induced by MSCs-driven PTX release in the tumor microenvironment.

METHODS

U87MG GBM cells were fluorescently labeled with the mCherry protein and grafted onto the brain of immunosuppressed rats. In adjacent brain regions, we injected green fluorescent protein-expressing murine MSCs, either loaded with PTX or unloaded. After 1 week survival, the xenografted brain was assessed by confocal microscopy for PTX-induced cell damage.

RESULTS

Overall, MSCs showed remarkable tropism towards the tumor. In rats grafted with PTX-MSCs, the nuclei of U87MG cells showed changes that are typically induced by PTX, including multi-spindle mitoses, centrosome number alterations, and nuclear fragmentation. Multi-spindle mitoses resulted in multinucleated cells that were significantly higher in tumors co-grafted with PTX-MSCs than in controls. Nuclear changes did not occur in astrocytes and neurons surrounding the tumor.

CONCLUSIONS

MSCs appear particularly suited for anti-neoplastic drug delivery in the brain since PTX-specific damage of GBM cells can be achieved avoiding side effects to the normal tissue.

Human amniotic mesenchymal stromal cells (hAMSCs) as potential vehicles for drug delivery in cancer therapy: an in vitro study

INTRODUCTION

In the context of drug delivery, mesenchymal stromal cells (MSCs) from bone marrow and adipose tissue have emerged as interesting candidates due to their homing abilities and capacity to carry toxic loads, while at the same time being highly resistant to the toxic effects. Amongst the many sources of MSCs which have been identified, the human term placenta has attracted particular interest due to its unique, tissue-related characteristics, including its high cell yield and virtually absent expression of human leukocyte antigens and co-stimulatory molecules. Under basal, non-stimulatory conditions, placental MSCs also possess basic characteristics common to MSCs from other sources. These include the ability to secrete factors which promote cell growth and tissue repair, as well as immunomodulatory properties. The aim of this study was to investigate MSCs isolated from the amniotic membrane of human term placenta (hAMSCs) as candidates for drug delivery in vitro.

METHODS

We primed hAMSCs from seven different donors with paclitaxel (PTX) and investigated their ability to resist the cytotoxic effects of PTX, to upload the drug, and to release it over time. We then analyzed whether the uptake and release of PTX was sufficient to inhibit proliferation of CFPAC-1, a pancreatic tumor cell line sensitive to PTX.

RESULTS

For the first time, our study shows that hAMSCs are highly resistant to PTX and are not only able to uptake the drug, but also release it over time. Moreover, we show that PTX is released from hAMSCs in a sufficient amount to inhibit tumor cell proliferation, whilst some of the PTX is also retained within the cells.

CONCLUSION

Taken together, for the first time our results show that placental stem cells can be used as vehicles for the delivery of cytotoxic agents.

Drug-releasing mesenchymal cells strongly suppress B16 lung metastasis in a syngeneic murine model

BACKGROUND

Mesenchymal stromal cells (MSCs) are considered an important therapeutic tool in cancer therapy. They possess intrinsic therapeutic potential and can also be in vitro manipulated and engineered to produce therapeutic molecules that can be delivered to the site of diseases, through their capacity to home pathological tissues. We have recently demonstrated that MSCs, upon in vitro priming with anti-cancer drug, become drug-releasing mesenchymal cells (Dr-MCs) able to strongly inhibit cancer cells growth.

METHODS

Murine mesenchymal stromal cells were loaded with Paclitaxel (Dr-MCsPTX) according to a standardized procedure and their ability to inhibit the growth of a murine B16 melanoma was verified by in vitro assays. The anti-metastatic activity of Dr-MCsPTX was then studied in mice injected i.v. with B16 melanoma cells that produced lung metastatic nodules. Lung nodules were counted under a dissecting stereomicroscope and metastasis investigated by histological analysis.

RESULTS

We found that three i.v. injections of Dr-MCsPTX on day 5, 10 and 15 after tumor injection almost completely abolished B16 lung metastasis. Dr-MCsPTX arrested into lung by interacting with endothelium and migrate toward cancer nodule through a complex mechanism involving primarily mouse lung stromal cells (mL-StCs) and SDF-1/CXCR4/CXCR7 axis.

CONCLUSIONS

Our results show for the first time that Dr-MCsPTX are very effective to inhibit lung metastasis formation. Actually, a cure for lung metastasis in humans is mostly unlikely and we do not know whether a therapy combining engineered MSCs and Dr-MCs may work synergistically. However, we think that our approach using Dr-MCs loaded with PTX may represent a new valid and additive therapeutic tool to fight lung metastases and, perhaps, primary lung cancers in human.

Abstract 4237: Drug-releasing mesenchymal cells strongly suppress B16 lung metastasis in a syngeneic murine model

Mesenchymal stromal cells (MSCs) are considered an important therapeutic tool in cancer therapy. Because MSCs may home tumor microenvironment they have the possibility to directly delivery molecules to cancer cells. We have demonstrated that MSCs, upon in vitro priming with anti-cancer drug, become drug-releasing mesenchymal cells (Dr-MCs) able to strongly inhibit cancer cells growth. In order to expand our studies we here investigated whether intravenous (i.v) injection of MSCs loaded with Paclitaxel (PTX) were able to reduce B16 melanoma lung metastasis formation. To this end, as Dr-MCs, the murine MSC line SR4987 was used. SR4987 cells were loaded with PTX (SR4987PTX) by incubating for 24h with 2000ng/ml PTX. The anti-metastatic activity of SR4987PTX was evaluated in mice injected i.v. with 2.5 × 105 B16 melanoma cells. Tracking of the SR4987 in the lung was studied by immunohistochemistry using anti-Sca-1 antibodies. Adhesion and migration experiments were performed to elucidated the mechanism of SR4987PTX homing. In summary, we found that three i.v. injections of SR4987PTX on day 5, 10 and 15 after tumor injection almost completely (&gt;90% inhibition) abolished B16 lung metastasis. This effect was significantly superior (p&lt;0.01) than PTX given at the maximal tolerated dose of 10mg/Kg. SR4987PTX arrested into lung by interacting with endothelium and migrate toward cancer nodule through a complex mechanism involving primarily mouse lung stromal cells (mL-StCs). Indeed in vitro data show that mL-StCs treated with the conditioned medium (CM) of B16 cells (B16-CM) increase adhesion of SR4987PTX on lung endothelium (L-MECs) and stimulated their migration. In this contest the addition of the inflammatory cytokine TNFα enhanced both adhesion and migration of SR4987PTX. Additionally, we found that mL-StCs induce migration of SR4987PTX through the release SDF-1. Indeed, blocking SDF-1 activity by using anti-SDF-1 antibodies or its receptors CXCR4/CXCR7 with the compound AMD3100, migration of SR4987PTX was strongly reduced. In vivo SDF-1 expression was increased in mL-StCs surrounding metastases, while the presence of Sca-1+ cells nearby metastasis as well in the infiltrating microvessels confirmed the cancer homing capability of SR4987PTX. In conclusion, because it is known that cancer recruits circulating MSCs to form its stroma, it is proposed to exploit this property to fight it, by administrating exogenous MSCs carrying anticancer molecules. Our results show for the first time that Dr-MCs loaded with PTX are very effective as “Trojan horses” to delivery the drug and to strongly inhibit lung metastasis formation. Actually, a cure for lung metastasis in human is mostly unlikely, we think that our approach of using Dr-MCs loaded with PTX may represent a new valid and additive therapeutic tool to fight metastases and, perhaps, lung cancers in human.

Citation Format: Giulio Alessandri, Carlo Leonetti, Simona Artuso, Augusto Orlandi, Daniela Passeri, Anna Benetti, Angiola Berenzi, Enrico Dessy, Luisa Pascucci, Piero Ceccarelli, Arianna Bonomi, Valentina Coccè, Nazario Portolani, Valentina Ceserani, Eugenio Parati, Augusto Pessina. Drug-releasing mesenchymal cells strongly suppress B16 lung metastasis in a syngeneic murine model. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4237. doi:10.1158/1538-7445.AM2015-4237

Human mesenchymal stromal cells can uptake and release ciprofloxacin, acquiring in vitro anti-bacterial activity

BACKGROUND AIMS

Traditional antibiotic therapy is based on the oral or systemic injection of antibiotics that are often unable to stop a deep infection (eg, osteomyelitis). We studied whether or not bone marrow stromal cells (BM-MSCs) are able to uptake and release ciprofloxacin (CPX), a fluoroquinolone considered the drug of choice for the treatment of chronic osteomyelitis because of its favorable penetration into poorly vascularized sites of infection.

METHODS

Human bone marrow stromal cells (BM-MSCs) were primed with CPX (BM-MSCsCPX) according to a methodology previously standardized in our laboratory for paclitaxel (PTX). The anti-microbial activity of CPX released from BM-MSCs cells (BM-MSCsCPX-CM) or supernatant from cell lysate (BM-MSCsCPX-LYS) was evaluated by agar dilution and microdilution methods on three bacterial strains (Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa). To investigate whether or not primed cells (BM-MSCsCPX) were able to directly act on the bacterial growth, co-colture was performed by mixing E. coli suspension to an increasing number of BM-MSCsCPX. The anti-bacterial activity was determined as number of BM-MSCsCPX that completely inhibited bacterial growth.

RESULTS

The results demonstrated that BM-MSCsCPX are able to uptake and then release CPX in the conditioned medium. The loaded antibiotic maintains its active form throughout the process as tested on bacteria.

CONCLUSIONS

Our findings suggest that CPX-loaded MSCs may represent an important device for carrying and delivering CPX (and perhaps other antibiotics) into infected deep microenvironments; they could be used for local application and by systemic infusion when their homing capacity into the bone is cleared.

Paclitaxel is incorporated by mesenchymal stromal cells and released in exosomes that inhibit in vitro tumor growth: a new approach for drug delivery

Mesenchymal stromal cells (MSCs) have been proposed for delivering anticancer agents because of their ability to home in on tumor microenvironment. We found that MSCs can acquire strong anti-tumor activity after priming with Paclitaxel (PTX) through their capacity to uptake and then release the drug. Because MSCs secrete a high amount of membrane microvesicles (MVs), we here investigated the role of MVs in the releasing mechanism of PTX. The murine SR4987 line was used as MSC model. The release of PTX from SR4987 in the conditioned medium (CM) was checked by HPLC and the anti-tumor activity of both CM and MVs was tested on the human pancreatic cell line CFPAC-1. MVs were isolated by ultracentrifugation, analyzed by transmission (TEM) and scanning electron microscopy (SEM), and the presence of PTX by the Fourier transformed infrared (FTIR) microspectroscopy. SR4987 loaded with PTX (SR4987PTX) secreted a significant amount of PTX and their CM possessed strong anti-proliferative activity on CFPAC-1. At TEM and SEM, SR4987PTX showed an increased number of "vacuole-like" structures and shed a relevant number of MVs, but did not differ from untreated SR4987. However, SR4987PTX-derived-MVs (SR4987PTX-MVs) demonstrated a strong anti proliferative activity on CFPAC-1. FTIR analysis of SR4987PTX-MVs showed the presence of an absorption spectrum in the corresponding regions of the PTX marker, absent in MVs from SR4987. Our work is the first demonstration that MSCs are able to package and deliver active drugs through their MVs, suggesting the possibility of using MSCs as a factory to develop drugs with a higher cell-target specificity.

Immortalization of human adipose-derived stromal cells: production of cell lines with high growth rate, mesenchymal marker expression and capability to secrete high levels of angiogenic factors

INTRODUCTION

Human adipose-derived stromal cells (hASCs), due to their relative feasibility of isolation and ability to secrete large amounts of angiogenic factors, are being evaluated for regenerative medicine. However, their limited culture life span may represent an obstacle for both preclinical investigation and therapeutic use. To overcome this problem, hASCs immortalization was performed in order to obtain cells with in vitro prolonged life span but still maintain their mesenchymal marker expression and ability to secrete angiogenic factors.

METHODS

hASCs were transduced with the human telomerase reverse transcriptase (hTERT) gene alone or in combination with either SV-40 or HPV E6/E7 genes. Mesenchymal marker expression on immortalized hASCs lines was confirmed by flow cytometry (FC), differentiation potential was evaluated by immunocytochemistry and ELISA kits were used for evaluation of angiogenic factors. Green fluorescent protein (GFP) gene transduction was used to obtain fluorescent cells.

RESULTS

We found that hTERT alone failed to immortalize hASCs (hASCs-T), while hTERT/SV40 (hASCs-TS) or hTERT/HPV E6/E7 (hASCs-TE) co-transductions successfully immortalized cells. Both hASCs-TS and hASCs-TE were cultured for up to one year with a population doubling level (PDL) up to 100. Comparative studies between parental not transduced (hASCs-M) and immortalized cell lines showed that both hASCs-TS and hASCs-TE maintained a mesenchymal phenotypic profile, whereas differentiation properties were reduced particularly in hASCs-TS. Interestingly, hASCs-TS and hASCs-TE showed a capability to secrete significant amount of HGF and VEGF. Furthermore, hASCs-TS and hASCs-TE did not show tumorigenic properties in vitro although some chromosomal aberrations were detected. Finally, hASCs-TS and hASCs-TE lines were stably fluorescent upon transduction with the GFP gene.

CONCLUSIONS

Here we demonstrated, for the first time, that hASCs, upon immortalization, maintain a strong capacity to secrete potent angiogenic molecules. By combining hASCs immortalization and their paracrine characteristics, we have developed a "hybridoma-like model" of hASCs that could have potential applications for discovering and producing molecules to use in regenerative medicine (process scale-up).

Thiophene-based compounds as fluorescent tags to study mesenchymal stem cell uptake and release of taxanes

Human mesenchymal stem cells (hMSC) are multipotent cells that display the unique ability to home and engraft in tumor stroma. This remarkable tumor tropic property has generated a great deal of interest in many clinical settings. Recently, we showed that hMSC represent an excellent base for cell-mediated anticancer therapy since they are able to internalize paclitaxel (PTX) and to release it in an amount sufficient to inhibit tumor cell proliferation. In order to shed light on the dynamics of drug uptake and release, in the present paper we describe the synthesis of two novel thiophene-based fluorophore-paclitaxel conjugates, namely PTX-F32 and PTX-F35, as tools for in vitro drug tracking. We aimed to study the ability of these novel derivatives to be efficiently internalized by hMSC and, in a properly engineered coculture assay, to be released in the medium and taken up by tumor cells. In order to ensure better stability of the conjugates toward enzymatic hydrolysis, the selected oligothiophenes were connected to the taxol core at the C7 position through a carbamate linkage between PTX and the diamino linker. Antiproliferative experiments on both tumor cells and stromal cells clearly indicate that, in good correlation with the parent compound, cells are sensitive to nanomolar concentrations of the fluorescent conjugates. Moreover, in the coculture assay we were able to monitor, by fluorescence microscopy, PTX-F32 trafficking from hMSC toward glioblastoma U87 tumor cells. Our work paves the way for novel possibilities to perform extensive and high quality fluorescence-based analysis in order to better understand the cellular mechanisms involved in drug trafficking, such as microvescicle/exosome mediated release, in hMSC vehicle cells.

Decellularized silk fibroin scaffold primed with adipose mesenchymal stromal cells improves wound healing in diabetic mice

INTRODUCTION

Silk fibroin (SF) scaffolds have been shown to be a suitable substrate for tissue engineering and to improve tissue regeneration when cellularized with mesenchymal stromal cells (MSCs). We here demonstrate, for the first time, that electrospun nanofibrous SF patches cellularized with human adipose-derived MSCs (Ad-MSCs-SF), or decellularized (D-Ad-MSCs-SF), are effective in the treatment of skin wounds, improving skin regeneration in db/db diabetic mice.

METHODS

The conformational and structural analyses of SF and D-Ad-MSCs-SF patches were performed by scanning electron microscopy, confocal microscopy, Fourier transform infrared spectroscopy and differential scanning calorimetry. Wounds were performed by a 5 mm punch biopsy tool on the mouse's back. Ad-MSCs-SF and D-Ad-MSCs-SF patches were transplanted and the efficacy of treatments was assessed by measuring the wound closure area, by histological examination and by gene expression profile. We further investigated the in vitro angiogenic properties of Ad-MSCs-SF and D-Ad-MSCs-SF patches by affecting migration of human umbilical vein endothelial cells (HUVECs), keratinocytes (KCs) and dermal fibroblasts (DFs), through the aortic ring assay and, finally, by evaluating the release of angiogenic factors.

RESULTS

We found that Ad-MSCs adhere and grow on SF, maintaining their phenotypic mesenchymal profile and differentiation capacity. Conformational and structural analyses on SF and D-Ad-MSCs-SF samples, showed that sterilization, decellularization, freezing and storing did not affect the SF structure. When grafted in wounds of diabetic mice, both Ad-MSCs-SF and D-Ad-MSCs-SF significantly improved tissue regeneration, reducing the wound area respectively by 40% and 35%, within three days, completing the process in around 10 days compared to 15-17 days of controls. RT2 gene profile analysis of the wounds treated with Ad-MSCs-SF and D-Ad-MSCs-SF showed an increment of genes involved in angiogenesis and matrix remodeling. Finally, Ad-MSCs-SF and D-Ad-MSCs-SF co-cultured with HUVECs, DFs and KCs, preferentially enhanced the HUVECs' migration and the release of angiogenic factors stimulating microvessel outgrowth in the aortic ring assay.

CONCLUSIONS

Our results highlight for the first time that D-Ad-MSCs-SF patches are almost as effective as Ad-MSCs-SF patches in the treatment of diabetic wounds, acting through a complex mechanism that involves stimulation of angiogenesis. Our data suggest a potential use of D-Ad-MSCs-SF patches in chronic diabetic ulcers in humans.

[What new fathers know, think and do: a survey about fathering's attitudes, beliefs and behaviors in a sample of 570 men just after the birth of their newborn]

AIM

The aim of this paper was to know and analyze information, attitudes and behaviors related with transformations occurring in men when they become fathers.

METHODS

A self-administered questionnaire has been given out to all men whose newborns were born in the Hospitals located into Borgosesia, Ivrea, Novara, Verbania and Vercelli (Piedmont region in north west of the Italy) in the last quarter of 2006. The questionnaire was created ad hoc and filled out on the day of discharge; results underwent statistical analyses through SPSS system.

RESULTS

For the duration of the research, out of 870 men who became fathers in the hospitals were involved in this study, 570 responded voluntarily to the self-administered questionnaire (65.6% of the total sample). They showed a lack of information about how to take care of their newborns and the emotional turmoil of women after delivery (58% think children are blind when they are born, 52% think it is better to breastfeed newborns at fixed times and 47% ignore that mothers can enter a depression state). Eighty-eight percent of respondents were in the delivery room to see their child's birth, 56% took a leave from job to stay with mother and child in the hospital and 58% of them report the intention to take an additional 2-3 days leave after coming home from the hospital; 27% had trouble sleeping during pregnancy and are afraid not to be good fathers for their child; 90% believe that their newborn will make them change life habits. Most of the new fathers had difficulties in sharing emotions and feelings related with their status of fathers-to-be with other men. Some of these results are significantly different in older fathers, fathers having their first child and fathers with a lesser level of education.

CONCLUSION

During pregnancy and in the first months after their child is born, fathers-to-be and new fathers must be considered a potential target for educational interventions aiming at promoting their parenting information and reinforcing their positive attitudes and beliefs related with their fathering status.

CFU-GM assay for evaluation of drug myelotoxic activity

To study hematotoxicity of compounds on the myeloid cell compartment, the authors describe a standard procedure developed as a workable good laboratory practices-compliant protocol to determine the in vitro myelotoxic effect of drugs and chemicals. Specific protocols are presented to prepare human and murine myeloid progenitors (CFU-GM) for testing in a validated CFU-GM assay. Details are given for performing a screening test when toxicity data are not available and for passing on to an accurate inhibitory concentration-determination phase. To quantify the potential hematotoxicity of xenobiotics from their direct adverse effects on CFU-GM, the unit describes how to manage the results by means of an algorithm able to predict the acute xenobiotic exposure levels that cause maximum tolerated decreases (MTD) in absolute neutrophil count (ANC). A protocol describes a miniaturized application of the procedure in 96-well plates for high-throughput screening of compounds or for testing compounds that are available in very small quantities.

Human skin-derived fibroblasts acquire in vitro anti-tumor potential after priming with Paclitaxel

The main goal in cancer chemotherapy is to drive the drug into the tumor microenvironment to kill as many cancer cells as possible while producing the lowest collateral toxicity. Previously, we have shown that human bone marrow derived mesenchymal stromal cells (hBM-MSCs) exposed to Paclitaxel (PTX) were able to uptake and subsequently release the drug in the culture medium. PTX primed hBM-MSCs (hBM-MSCsPTX) located in the vicinity of cancer cells produced a strong inhibition of tumor cell growth both in vitro and in vivo. To expand these observations, in the present study we exposed human skin derived fibroblasts (hSDFs) to 2,000 ng/ml of PTX and then tested both cells and their conditioned medium (CM) in vitro for their capacity to inhibit the proliferation of human tumor cell lines (MOLT-4, DU-145, U87-MG, SH-SY5Y(+) and LAN-5). We found that hSDFs primed with PTX (hSDFsPTX) were able to uptake and subsequently release PTX in a time dependent manner. hSDFsPTX-derived CM(hSDFsPTX-CM) from 1:4 to 1:10 dilutions produced a significant (p < 0.05) in vitro tumor growth inhibition. hSDFsPTX co-cultured with leukemia cells at 1:1 to 1:10 ratio, completely inhibited cells growth whereas no inhibition was induced by normal hSDFs cells. Our results demonstrate for the first time that hSDFs can be loaded in vitro with PTX and thus can acquire a potent anti-tumor activity. Since hSDFs can be easily isolated from skin biopsies without any particular pain and discomfort to donor patients, we conclude that hSDFs may represent a valid cell type option for carrying and delivering anti-cancer drugs.

Mesenchymal stromal cells primed with paclitaxel provide a new approach for cancer therapy

BACKGROUND

Mesenchymal stromal cells may represent an ideal candidate to deliver anti-cancer drugs. In a previous study, we demonstrated that exposure of mouse bone marrow derived stromal cells to Doxorubicin led them to acquire anti-proliferative potential towards co-cultured haematopoietic stem cells (HSCs). We thus hypothesized whether freshly isolated human bone marrow Mesenchymal stem cells (hMSCs) and mature murine stromal cells (SR4987 line) primed in vitro with anti-cancer drugs and then localized near cancer cells, could inhibit proliferation.

METHODS AND PRINCIPAL FINDINGS

Paclitaxel (PTX) was used to prime culture of hMSCs and SR4987. Incorporation of PTX into hMSCs was studied by using FICT-labelled-PTX and analyzed by FACS and confocal microscopy. Release of PTX in culture medium by PTX primed hMSCs (hMSCsPTX) was investigated by HPLC. Culture of Endothelial cells (ECs) and aorta ring assay were used to test the anti-angiogenic activity of hMSCsPTX and PTX primed SR4987(SR4987PTX), while anti-tumor activity was tested in vitro on the proliferation of different tumor cell lines and in vivo by co-transplanting hMSCsPTX and SR4987PTX with cancer cells in mice. Nevertheless, despite a loss of cells due to chemo-induced apoptosis, both hMSCs and SR4987 were able to rapidly incorporate PTX and could slowly release PTX in the culture medium in a time dependent manner. PTX primed cells acquired a potent anti-tumor and anti-angiogenic activity in vitro that was dose dependent, and demonstrable by using their conditioned medium or by co-culture assay. Finally, hMSCsPTX and SR4987PTX co-injected with human cancer cells (DU145 and U87MG) and mouse melanoma cells (B16) in immunodeficient and in syngenic mice significantly delayed tumor takes and reduced tumor growth.

CONCLUSIONS

These data demonstrate, for the first time, that without any genetic manipulation, mesenchymal stromal cells can uptake and subsequently slowly release PTX. This may lead to potential new tools to increase efficacy of cancer therapy.

Molecular analysis of relapses or reinfections of Clostridium difficile-associated diarrhea

Recurrence is a major complication of Clostridium difficile-associated diarrhea and occurs in 15 to 20% of patients after discontinuation of therapy. Strains from 53 patients with Clostridium difficile recurrences were fingerprinted by PCR ribotyping. Reinfection with a different strain occurred in 15 out of 53 patients (28,3%), while 38 patients relapsed. These data suggest the need to perform molecular typing for implementation of infection control procedures and for a more appropriate therapeutic strategy.

Abstract 4354: Mesenchymal stem cells loaded with paclitaxel inhibit tumor growth and angiogenesis

Background: Mesenchymal stem cells (MSCs) may represent an ideal candidate to deliver anti-cancer drugs. In a previous study, we demonstrated that simple exposure of bone marrow (BM) derived MSCs to high doses of Doxorubicin, led them to acquire anti-proliferative potential towards co-cultured haematopoitic stem cells (HSCs). We thus hypothesized whether MSCs, once primed in vitro with anti-cancer drugs and then localized near cancer cells, can inhibit proliferation. Methods: Paclitaxel (PTX) was used to prime culture of mouse and human MSCs. Incorporation of PTX into MSCs (MSCsPTX) was studied by using FICT-labelled-PTX and analyzed by FACS and confocal microscopy. Release of PTX in culture medium by MSCsPTX was investigated by HPLC. Culture of Endothelial cells (ECs) and aorta ring assay were used to test the anti-angiogenic activity of MSCsPTX, while anti-tumor activity was tested in vitro on the proliferation of different tumor cell lines and in vivo by co-transplanting MSCsPTX with cancer cells in mice.

Results: MSCs were able to rapidly incorporate PTX and could slowly release PTX in the culture medium in a time dependent manner. Primed MSCsPTX acquired a potent anti-tumor and anti-angiogenic activity in vitro that was dose dependent, and demonstrable by using their conditioned medium or by co-culture assay. Finally, MSCsPTX co-injected in immunodeficient mice with DU145 and B16 cancer cells, significantly delayed tumor takes and reduced tumor growth.

Conclusions: These data demonstrate that, without any genetic manipulation, MSCs can uptake and subsequently slowly release PTX, becoming a potential new tool for cancer therapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4354. doi:10.1158/1538-7445.AM2011-4354