Chemoprotection effect of multidrug resistance 1 (MDR1) gene transfer to hematopoietic progenitor cells and engrafted in mice with cancer allows intensified chemotherapy

Prognostic Factors and a Nomogram Predicting Overall Survival in Patients with Limb Chondrosarcomas: A Population-Based Study

Introduction

We aimed to develop and validate a nomogram for predicting the overall survival of patients with limb chondrosarcomas.

Methods

The Surveillance, Epidemiology, and End Results (SEER) program database was used to identify patients diagnosed with chondrosarcomas, from which data was extracted from 18 registries in the United States between 1973 and 2016. A total of 813 patients were selected from the database. Univariate and multivariate analyses were performed using Cox proportional hazards regression models on the training group to identify independent prognostic factors and construct a nomogram to predict the 3- and 5-year survival probability of patients with limb chondrosarcomas. The predictive values were compared using concordance indexes (C-indexes) and calibration plots.

Results

All 813 patients were randomly divided into a training group (n = 572) and a validation group (n = 241). After univariate and multivariate Cox regression, a nomogram was constructed based on a new model containing the predictive variables of age, site, grade, tumor size, histology, stage, and use of surgery, radiotherapy, or chemotherapy. The prediction model provided excellent C-indexes (0.86 and 0.77 in the training and validation groups, respectively). The good discrimination and calibration of the nomograms were demonstrated for both the training and validation groups.

Conclusions

The nomograms precisely and individually predict the overall survival of patients with limb chondrosarcomas and could assist personalized prognostic evaluation and individualized clinical decision-making.

Increased efficiency of testicular tumor chemotherapy by ultrasound microbubble-mediated targeted transfection of siMDR1

The MDR1 gene encoding P-glycoprotein (P-gp) is an ATP-dependent drug efflux transporter and is related to drug resistance of yolk sac tumors. Drug resistence may be an important factor for the low efficiency of chemotherapy in the treatment of testicular tumors. P-gp, encoded by the MDR1 gene, is an ATP-binding cassette transporter. P-gp exhibits high expression in capillary endothelial cells of the testis and prevents the intracellular accumulation of chemotherapy agents in testicular tumor cells, resulting in drug resistance. In the present study, we aimed to use specific siRNA to silence the expression of the MDR1 gene and P-gp, leading to the reversal of multidrug resistance of testicular tumors and contributing a suitable condition for chemotherapy. Ultrasound microbubble-mediated delivery is a safe and effective tool for gene delivery. In the present study, we demonstrated that ultrasound microbubble-mediated delivery effectively improved the siMDR1 gene transfection in interstitial capillary endothelial cells of the testis, inhibited the expression of P-gp and increased daunorubicin accumulation. The testis tumor model was successfully constructed by injecting 1x10(7) yolk sac tumor cells in 3-week-old Sprague-Dawley rats. Ultrasound microbubble-mediated siMDR1 gene therapy improved the effect of chemotherapy on the testicular tumors. The testicular volume was reduced, the number of tumor cells within the testicular tissues decreased, and pathological changes were mostly recovered. Therefore, the present study indicated that ultrasound microbubble-mediated siMDR1 gene therapy in vivo reversed drug resistance by regulating P-gp expression, providing a promising method for the treatment of testicular tumors.

Characterization of fibroblasts recruited from bone marrow-derived precursor in neonatal bronchopulmonary dysplasia mice

We sought to determine whether the extrapulmonary origin of fibroblasts derived from bone marrow (BM) progenitor cells is essential to lung fibrosis in bronchopulmonary dysplasia (BPD). Neonate mice were durably engrafted with BM isolated from transgenic reporter mice that expressed green fluorescent protein (GFP). Such chimera mice were subjected to 60% O(2) exposure for 14 days. A large number of fibroblast-specific protein-1 (FSP1) and GFP-positive fibroblasts were identified in active fibrotic lesions. More surprisingly, however, FSP1(+) fibroblasts also arose in considerable numbers from BM-derived alveolar type II cells (AT2) through epithelial-mesenchymal transition (EMT) during lung fibrogenesis. Cultured lung fibroblasts could express the CXC chemokine receptor (CXCR4) and responded chemotactically to their cognate ligand, chemokine (C-X-C motif) ligand 12 (CXCL12), which were elevated in the serum of BPD mice. These data suggest that lung fibroblasts in BPD fibrosis could variably arise from BM progenitor cells. This finding, which suggests the pathophysiological process of fibrosis, could contribute to a therapy for BPD that is characterized by extensive interstitial fibrosis.

Evaluation of biodistribution and safety of adenovirus vector containing MDR1 in mice

Background

The aim of this study is to examine the safety and distribution of Ad-EGFP-MDR1, an adenovirus encoding human multidurg resistance gene (human MDR1), in the mice colon carcinoma model.

Methods

After bone marrow cells (BMCs) were infected with Ad-EGFP-MDR1, they were administered by intra bone marrow-bone marrow transplantation (IBM-BMT). Total adenovirus antibody and serum adenovirus neutralizing factor (SNF) were determined. Biodistribution of Ad-EGFP-MDR1 was detected by in situ hybridization and immunohistochemistry. The peripheral hematocyte white blood cell (WBC), haemoglobin (Hb), red blood cell (RBC) and platelet (Plt) counts were analyzed.

Results

Neither total adenovirus antibody nor SNF increased weeks after BMT. In situ hybridization and immunohistochemistry demonstrated concordant expression of human MDR1 and P-gp which were found in lung, intestine, kidney and BMCs after BMT, but not detected in liver, spleen, brain and tumor. No significant abnormality of the recovery hematocyte was observed on Day 30 after treatment.

Conclusion

The results indicate that IBM-BMT administration of a replication defective adenovirus is a feasible mode of delivery, allowing exogenous transference. The findings in this study are conducted for the future long-term studies of safety assessment of Ad-EGFP-MDR1.