Genetically engineered endostatin-lidamycin fusion proteins effectively inhibit tumor growth and metastasis

Serum Endostatin Levels in Oral Squamous Cell Carcinoma

INTRODUCTION

Endostatin is a C-terminal proteolytic fragment of collagen XVIII and, as with angiostatin and thrombospondin, is known as an antiangiogenic agent. The aim of this study was to assess the level of serum endostatin in patients with oral squamous cell carcinoma (SCC), and its association with the clinicopathological characteristics of the tumor.

MATERIALS AND METHODS

Using an enzyme-linked immunosorbent assay (ELISA) kit, we investigated the circulating levels of endostatin in the blood serum of 45 patients with oral SCC and 45 healthy controls.

RESULTS

The mean level of serum endostatin in patients was significantly lower (68.8±85 ng/ml) than in healthy controls (175.6±73 ng/ml) (P<0.001). Serum endostatin levels were significantly lower in patients with lymph node metastasis compared with patients without lymph node metastasis (P<0.001). In addition, serum endostatin level was associated with higher histological grade (P<0.001). There were no apparent correlations between serum endostatin concentration and clinicopathological features such as age, gender, and tumor stage (P>0.05).

CONCLUSION

Findings of the present study suggest the prognostic and anti-metastatic role of endostatin, and this may be used as a tool for monitoring tumor progression.

Inhibiting effect of Endostar combined with ginsenoside Rg3 on breast cancer tumor growth in tumor-bearing mice

OBJECTIVE

To study the inhibiting effect of Endostar combined with ginsenoside Rg3 on breast cancer tumor growth in tumor-bearing mice.

METHODS

Female mice were selected as experimental animals, and breast cancer tumor-bearing mouse models were established and then divided into groups A, B, C and D that respectively received saline, recombinant human endostatin, ginsenosides Rg3 and recombinant human endostatin combined with Rg3 intervention; 7 d, 14 d and 21 d after intervention, tumor tissue volume was measured; 21 d after intervention, mice were killed, tumor tissue was collected, and mRNA contents of angiogenesis molecules, invasion molecules, autophagy marker molecules and autophagy signaling pathway molecules were detected.

RESULTS

At 7 d, 14 d and 21 d after intervention, tumor tissue volume of groups B, C and D was lower than that of group A, and tumor tissue volume of group D was lower than that of groups B and C; mRNA contents of VEGFA, VEGFB, VEGFC, MMP2, MMP9, p62, mTOR, PI3K, Akt, JNK and Beclin-1 in tumor tissue of groups B, C and D were significantly lower than those of group A, and LC3-II/LC3-I was significantly higher than that of group A; mRNA contents of VEGFA, VEGFB, VEGFC, MMP2, MMP9, p62, mTOR, PI3K, Akt, JNK and Beclin-1 in tumor tissue of group D were significantly lower than those of groups B and C, and LC3-II/LC3-I was higher than that of groups B and C.

CONCLUSIONS

Endostar combined with ginsenoside Rg3 has stronger inhibiting effect on breast cancer tumor growth in tumor-bearing mice than single drug, and it can inhibit angiogenesis and cell invasion, and enhance cell autophagy.

A high risk of osteosarcoma in individuals who are homozygous for the p.D104N in endostatin

The D104N polymorphism (p.D104N) in endostatin has been previously identified in many types of cancer, and this polymorphism is believed to be a phenotypic modulator in some tumors. However, it is unknown whether endostatin p.D104N affects the risk and progression of osteosarcoma (OS). Here, we analyzed the p.D104N endostatin variant in 236 patients with OS and 418 healthy individuals. Similar frequencies of wild type and heterozygous p.104DN endostatin were observed in controls and OS patients. Interestingly, the frequency of the homozygous p.D104N (p.104NN) genotype was higher in OS patients group compared to control group, suggesting that individuals with p.104NN endostatin have a significantly increased risk for OS. In addition, OS patients with p.104NN endostatin had a shorter survival time and a higher rate of metastasis than OS patients with wild type endostatin. Animal experiments revealed that overexpression of p.104NN endostatin did not significantly inhibit OS lung metastasis. Interestingly, administration of endostatin dramatically inhibited OS lung metastasis in the p.104NN endostatin xenograft model. Together, these results suggest that p.104NN of endostatin is associated with the risk of OS and demonstrates predictive significance for clinical outcome in OS patients. In addition, endostatin therapy may be necessary for OS patients harboring p.104NN endostatin.

Genetic polymorphisms in COL18A1 influence the development of osteosarcoma

We conducted a case-control study to investigate the association of COL18A1 D104N polymorphism in the development of osteosarcoma in a Chinese population. Between May 2012 and May 2014, 141 patients with pathologically proven osteosarcoma and 341 were selected into this study. Genotyping of COL18A1 D104N was analyzed using polymerase chain reaction (PCR) coupled with restriction fragment length polymorphism (RFLP). By logistic regression analysis, we found that individuals with the NN genotype of COL18A1 D104N were significantly associated with an increased risk of osteosarcoma when compared with the DD genotype (OR=20.97, 95% CI=2.74-933.42). In dominant model, the NN+DN genotype of COL18A1 D104N had a 1.99 fold risk of osteosarcoma when compared with the DD genotype. Moreover, the NN genotype was correlated with a 20.45 fold risk of osteosarcoma when compared with the DN+DD genotype in recessive model. However, we did not find significant interaction between COL18A1 D104N polymorphism and Enneking stage, histological subtype, tumor metastasis and tumor location of patients with osteosarcoma. In conclusion, our study suggests that the homozygous DN and NN genotypes of COL18A1 D104N were associated with the risk of osteosarcoma.

A novel antibody-drug conjugate anti-CD19(Fab)-LDM in the treatment of B-cell non-Hodgkin lymphoma xenografts with enhanced anticancer activity

BACKGROUND

Rituximab is widely used in clinical setting for the treatment of B malignant lymphoma and has achieved remarkable success. However, in most patients, the disease ultimately relapses and become resistant to rituximab. To overcome the limitation, there is still a need to find novel strategy for improving therapeutic efficacy.

OBJECTIVE

To construct genetically engineered antibody anti-CD19(Fab)-LDM, and verify the anticancer activity targeted toward B-lymphoma.

METHODS

The anticancer activity of anti-CD19(Fab)-LDM in vitro and in vivo was examined. In vitro, the binding activity and internalization of anti-CD19(Fab)-LDP were measured. Using comet assay and apoptosis, the cytotoxicity of energized fusion proteins was observed. From in vivo experiments, targeting of therapeutic effect and anticancer efficacy bythe fusion protein was verified.

RESULTS

Data showed that anti-CD19(Fab)-LDM does not only binding the cell surface but is also internalized into the cell. The energized fusion proteins anti-CD19(Fab)-LDM can induce DNA damage. Furthermore, significant in vivo therapeutic efficacy was observed.

CONCLUSION

The present study demonstrated that the genetically engineered antibody anti-CD19(Fab)-LDM exhibited enhanced cytotoxicity compared to LDM alone. One of the most powerful advantages of anti-CD19(Fab)-LDM, however, is that it can be internalized within the cells and carry out cytotoxic effects. Therefore, anti-CD19(Fab)-LDM may be as a useful targeted therapy for B-cell lymphoma.

Correlation of serum levels of endostatin with tumor stage in gastric cancer: a systematic review and meta-analysis

Background. We performed a systematic review and meta-analysis to study the association between serum endostatin levels and gastric cancer (GC) progression. Method. We searched the MEDLINE, Science Citation Index, Cochrane Library, PubMed, Embase, Current Contents Index, and several Chinese databases for published studies relevant to our study topic. Carefully selected studies were pooled and SMD and its corresponding 95% CI were calculated. Version 12.0 STATA software was used for statistical analysis. Results. Serum endostatin levels were analyzed in 12 case-control studies (736 GC patients and 350 controls). Significant differences in serum endostatin levels were observed between GC patients and the healthy controls (SMD = 1.418, 95% CI = 1.079~1.757, P < 0.001). Importantly, significantly lower levels of serum endostatin were found in I-II grade patients compared to those with III-IV grade tumors (P < 0.001). Further, higher serum endostatin levels were observed in the LN invasion-positive GC subjects in comparison with LN invasion-negative subjects (P < 0.001). Conclusion. Patients with GC exhibited elevated levels of serum endostatin than controls and its level showed a statistical correlation with the more aggressive type of GC, exhibiting invasion and LN metastasis. Thus, serum levels of endostatin being a useful prognostic biomarker for GC patients warrants further investigation.

Tuftsin-based, EGFR-targeting fusion protein and its enediyne-energized analog show high antitumor efficacy associated with CD47 down-regulation

Tuftsin (TF) is an immunomodulator tetrapeptide (Thr-Lys-Pro-Arg) that binds to the receptor neuropilin-1 (Nrp1) on the surface of cells. Many reports have described anti-tumor activity of tuftsin to relate with nonspecific activation of the host immune system. Lidamycin (LDM) that displays extremely potent cytotoxicity to cancer cells is composed of an apoprotein (LDP) and an enediyne chromophore (AE). In addition, Ec is an EGFR-targeting oligopeptide. In the present study, LDP was used as protein scaffold and the specific carrier for the highly potent AE. Genetically engineered fusion proteins LDP-TF and Ec-LDP-TF were prepared; then, the enediyne-energized fusion protein Ec-LDM-TF was generated by integration of AE into Ec-LDP-TF. The tuftsin-based fusion proteins LDP-TF and Ec-LDP-TF significantly enhanced the phagocytotic activity of macrophages as compared with LDP (P < 0.05). Ec-LDP-TF effectively bound to tumor cells and macrophages; furthermore, it markedly suppressed the growth of human epidermoid carcinoma A431 xenograft in athymic mice by 84.2 % (P < 0.05) with up-regulated expression of TNF-α and IFN-γ. Ec-LDM-TF further augmented the therapeutic efficacy, inhibiting the growth of A431 xenograft by 90.9 % (P < 0.05); notably, the Ec-LDM-TF caused marked down-regulation of CD47 in A431 cells. Moreover, the best therapeutic effect was recorded in the group of animals treated with the combination of Ec-LDP-TF with Ec-LDM-TF. The results suggest that tuftsin-based, enediyne-energized, and EGFR-targeting fusion proteins exert highly antitumor efficacy with CD47 modulation. Tuftsin-based fusion proteins are potentially useful for treatment of EGFR- and CD47-overexpressing cancers.